/* ---------------------------------------------------------------------------
- * $Id: Schedule.c,v 1.134 2002/03/12 13:57:11 simonmar Exp $
*
- * (c) The GHC Team, 1998-2000
+ * (c) The GHC Team, 1998-2005
*
- * Scheduler
- *
- * Different GHC ways use this scheduler quite differently (see comments below)
- * Here is the global picture:
- *
- * WAY Name CPP flag What's it for
- * --------------------------------------
- * mp GUM PAR Parallel execution on a distributed memory machine
- * s SMP SMP Parallel execution on a shared memory machine
- * mg GranSim GRAN Simulation of parallel execution
- * md GUM/GdH DIST Distributed execution (based on GUM)
+ * The scheduler and thread-related functionality
*
* --------------------------------------------------------------------------*/
-//@node Main scheduling code, , ,
-//@section Main scheduling code
-
-/*
- * Version with scheduler monitor support for SMPs (WAY=s):
-
- This design provides a high-level API to create and schedule threads etc.
- as documented in the SMP design document.
-
- It uses a monitor design controlled by a single mutex to exercise control
- over accesses to shared data structures, and builds on the Posix threads
- library.
-
- The majority of state is shared. In order to keep essential per-task state,
- there is a Capability structure, which contains all the information
- needed to run a thread: its STG registers, a pointer to its TSO, a
- nursery etc. During STG execution, a pointer to the capability is
- kept in a register (BaseReg).
-
- In a non-SMP build, there is one global capability, namely MainRegTable.
-
- SDM & KH, 10/99
-
- * Version with support for distributed memory parallelism aka GUM (WAY=mp):
-
- The main scheduling loop in GUM iterates until a finish message is received.
- In that case a global flag @receivedFinish@ is set and this instance of
- the RTS shuts down. See ghc/rts/parallel/HLComms.c:processMessages()
- for the handling of incoming messages, such as PP_FINISH.
- Note that in the parallel case we have a system manager that coordinates
- different PEs, each of which are running one instance of the RTS.
- See ghc/rts/parallel/SysMan.c for the main routine of the parallel program.
- From this routine processes executing ghc/rts/Main.c are spawned. -- HWL
-
- * Version with support for simulating parallel execution aka GranSim (WAY=mg):
-
- The main scheduling code in GranSim is quite different from that in std
- (concurrent) Haskell: while concurrent Haskell just iterates over the
- threads in the runnable queue, GranSim is event driven, i.e. it iterates
- over the events in the global event queue. -- HWL
-*/
-
-//@menu
-//* Includes::
-//* Variables and Data structures::
-//* Main scheduling loop::
-//* Suspend and Resume::
-//* Run queue code::
-//* Garbage Collextion Routines::
-//* Blocking Queue Routines::
-//* Exception Handling Routines::
-//* Debugging Routines::
-//* Index::
-//@end menu
-
-//@node Includes, Variables and Data structures, Main scheduling code, Main scheduling code
-//@subsection Includes
-
#include "PosixSource.h"
#include "Rts.h"
#include "SchedAPI.h"
#include "RtsUtils.h"
#include "RtsFlags.h"
+#include "BlockAlloc.h"
+#include "OSThreads.h"
#include "Storage.h"
#include "StgRun.h"
-#include "StgStartup.h"
#include "Hooks.h"
#include "Schedule.h"
#include "StgMiscClosures.h"
-#include "Storage.h"
#include "Interpreter.h"
#include "Exception.h"
#include "Printer.h"
-#include "Main.h"
-#include "Signals.h"
+#include "RtsSignals.h"
#include "Sanity.h"
#include "Stats.h"
-#include "Itimer.h"
+#include "STM.h"
+#include "Timer.h"
#include "Prelude.h"
+#include "ThreadLabels.h"
+#include "LdvProfile.h"
+#include "Updates.h"
#ifdef PROFILING
#include "Proftimer.h"
#include "ProfHeap.h"
#endif
-#if defined(GRAN) || defined(PAR)
+#if defined(GRAN) || defined(PARALLEL_HASKELL)
# include "GranSimRts.h"
# include "GranSim.h"
# include "ParallelRts.h"
#endif
#include "Sparks.h"
#include "Capability.h"
-#include "OSThreads.h"
-#include "Task.h"
+#include "Task.h"
+#include "AwaitEvent.h"
+#if defined(mingw32_HOST_OS)
+#include "win32/IOManager.h"
+#endif
+
+#ifdef HAVE_SYS_TYPES_H
+#include <sys/types.h>
+#endif
+#ifdef HAVE_UNISTD_H
+#include <unistd.h>
+#endif
+#include <string.h>
+#include <stdlib.h>
#include <stdarg.h>
-//@node Variables and Data structures, Prototypes, Includes, Main scheduling code
-//@subsection Variables and Data structures
+#ifdef HAVE_ERRNO_H
+#include <errno.h>
+#endif
-/* Main thread queue.
- * Locks required: sched_mutex.
- */
-StgMainThread *main_threads;
+// Turn off inlining when debugging - it obfuscates things
+#ifdef DEBUG
+# undef STATIC_INLINE
+# define STATIC_INLINE static
+#endif
+
+/* -----------------------------------------------------------------------------
+ * Global variables
+ * -------------------------------------------------------------------------- */
-/* Thread queues.
- * Locks required: sched_mutex.
- */
#if defined(GRAN)
StgTSO* ActiveTSO = NULL; /* for assigning system costs; GranSim-Light only */
#else /* !GRAN */
-StgTSO *run_queue_hd, *run_queue_tl;
-StgTSO *blocked_queue_hd, *blocked_queue_tl;
-StgTSO *sleeping_queue; /* perhaps replace with a hash table? */
+#if !defined(THREADED_RTS)
+// Blocked/sleeping thrads
+StgTSO *blocked_queue_hd = NULL;
+StgTSO *blocked_queue_tl = NULL;
+StgTSO *sleeping_queue = NULL; // perhaps replace with a hash table?
+#endif
+/* Threads blocked on blackholes.
+ * LOCK: sched_mutex+capability, or all capabilities
+ */
+StgTSO *blackhole_queue = NULL;
#endif
+/* The blackhole_queue should be checked for threads to wake up. See
+ * Schedule.h for more thorough comment.
+ * LOCK: none (doesn't matter if we miss an update)
+ */
+rtsBool blackholes_need_checking = rtsFalse;
+
/* Linked list of all threads.
* Used for detecting garbage collected threads.
+ * LOCK: sched_mutex+capability, or all capabilities
*/
-StgTSO *all_threads;
+StgTSO *all_threads = NULL;
-/* When a thread performs a safe C call (_ccall_GC, using old
- * terminology), it gets put on the suspended_ccalling_threads
- * list. Used by the garbage collector.
+/* flag set by signal handler to precipitate a context switch
+ * LOCK: none (just an advisory flag)
*/
-static StgTSO *suspended_ccalling_threads;
-
-static StgTSO *threadStackOverflow(StgTSO *tso);
-
-/* KH: The following two flags are shared memory locations. There is no need
- to lock them, since they are only unset at the end of a scheduler
- operation.
-*/
+int context_switch = 0;
-/* flag set by signal handler to precipitate a context switch */
-//@cindex context_switch
-nat context_switch;
+/* flag that tracks whether we have done any execution in this time slice.
+ * LOCK: currently none, perhaps we should lock (but needs to be
+ * updated in the fast path of the scheduler).
+ */
+nat recent_activity = ACTIVITY_YES;
-/* if this flag is set as well, give up execution */
-//@cindex interrupted
-rtsBool interrupted;
+/* if this flag is set as well, give up execution
+ * LOCK: none (changes once, from false->true)
+ */
+rtsBool sched_state = SCHED_RUNNING;
/* Next thread ID to allocate.
- * Locks required: sched_mutex
+ * LOCK: sched_mutex
*/
-//@cindex next_thread_id
-StgThreadID next_thread_id = 1;
+static StgThreadID next_thread_id = 1;
-/*
- * Pointers to the state of the current thread.
- * Rule of thumb: if CurrentTSO != NULL, then we're running a Haskell
- * thread. If CurrentTSO == NULL, then we're at the scheduler level.
- */
-
/* The smallest stack size that makes any sense is:
* RESERVED_STACK_WORDS (so we can get back from the stack overflow)
* + sizeofW(StgStopFrame) (the stg_stop_thread_info frame)
- * + 1 (the realworld token for an IO thread)
* + 1 (the closure to enter)
+ * + 1 (stg_ap_v_ret)
+ * + 1 (spare slot req'd by stg_ap_v_ret)
*
* A thread with this stack will bomb immediately with a stack
* overflow, which will increase its stack size.
*/
-
-#define MIN_STACK_WORDS (RESERVED_STACK_WORDS + sizeofW(StgStopFrame) + 2)
-
+#define MIN_STACK_WORDS (RESERVED_STACK_WORDS + sizeofW(StgStopFrame) + 3)
#if defined(GRAN)
StgTSO *CurrentTSO;
*/
StgTSO dummy_tso;
-rtsBool ready_to_gc;
-
-void addToBlockedQueue ( StgTSO *tso );
+/*
+ * Set to TRUE when entering a shutdown state (via shutdownHaskellAndExit()) --
+ * in an MT setting, needed to signal that a worker thread shouldn't hang around
+ * in the scheduler when it is out of work.
+ */
+rtsBool shutting_down_scheduler = rtsFalse;
-static void schedule ( void );
- void interruptStgRts ( void );
-#if defined(GRAN)
-static StgTSO * createThread_ ( nat size, rtsBool have_lock, StgInt pri );
-#else
-static StgTSO * createThread_ ( nat size, rtsBool have_lock );
+/*
+ * This mutex protects most of the global scheduler data in
+ * the THREADED_RTS runtime.
+ */
+#if defined(THREADED_RTS)
+Mutex sched_mutex;
#endif
-static void detectBlackHoles ( void );
-
-#ifdef DEBUG
-static void sched_belch(char *s, ...);
+#if defined(PARALLEL_HASKELL)
+StgTSO *LastTSO;
+rtsTime TimeOfLastYield;
+rtsBool emitSchedule = rtsTrue;
#endif
-#if defined(RTS_SUPPORTS_THREADS)
-/* ToDo: carefully document the invariants that go together
- * with these synchronisation objects.
- */
-Mutex sched_mutex = INIT_MUTEX_VAR;
-Mutex term_mutex = INIT_MUTEX_VAR;
+/* -----------------------------------------------------------------------------
+ * static function prototypes
+ * -------------------------------------------------------------------------- */
-# if defined(SMP)
-static Condition gc_pending_cond = INIT_COND_VAR;
-nat await_death;
-# endif
+static Capability *schedule (Capability *initialCapability, Task *task);
-#endif /* RTS_SUPPORTS_THREADS */
+//
+// These function all encapsulate parts of the scheduler loop, and are
+// abstracted only to make the structure and control flow of the
+// scheduler clearer.
+//
+static void schedulePreLoop (void);
+#if defined(THREADED_RTS)
+static void schedulePushWork(Capability *cap, Task *task);
+#endif
+static void scheduleStartSignalHandlers (Capability *cap);
+static void scheduleCheckBlockedThreads (Capability *cap);
+static void scheduleCheckBlackHoles (Capability *cap);
+static void scheduleDetectDeadlock (Capability *cap, Task *task);
+#if defined(GRAN)
+static StgTSO *scheduleProcessEvent(rtsEvent *event);
+#endif
+#if defined(PARALLEL_HASKELL)
+static StgTSO *scheduleSendPendingMessages(void);
+static void scheduleActivateSpark(void);
+static rtsBool scheduleGetRemoteWork(rtsBool *receivedFinish);
+#endif
+#if defined(PAR) || defined(GRAN)
+static void scheduleGranParReport(void);
+#endif
+static void schedulePostRunThread(void);
+static rtsBool scheduleHandleHeapOverflow( Capability *cap, StgTSO *t );
+static void scheduleHandleStackOverflow( Capability *cap, Task *task,
+ StgTSO *t);
+static rtsBool scheduleHandleYield( Capability *cap, StgTSO *t,
+ nat prev_what_next );
+static void scheduleHandleThreadBlocked( StgTSO *t );
+static rtsBool scheduleHandleThreadFinished( Capability *cap, Task *task,
+ StgTSO *t );
+static rtsBool scheduleDoHeapProfile(rtsBool ready_to_gc);
+static Capability *scheduleDoGC(Capability *cap, Task *task,
+ rtsBool force_major,
+ void (*get_roots)(evac_fn));
+
+static void unblockThread(Capability *cap, StgTSO *tso);
+static rtsBool checkBlackHoles(Capability *cap);
+static void AllRoots(evac_fn evac);
+
+static StgTSO *threadStackOverflow(Capability *cap, StgTSO *tso);
+
+static void raiseAsync_(Capability *cap, StgTSO *tso, StgClosure *exception,
+ rtsBool stop_at_atomically, StgPtr stop_here);
+
+static void deleteThread (Capability *cap, StgTSO *tso);
+static void deleteAllThreads (Capability *cap);
-#if defined(PAR)
-StgTSO *LastTSO;
-rtsTime TimeOfLastYield;
-rtsBool emitSchedule = rtsTrue;
+#ifdef DEBUG
+static void printThreadBlockage(StgTSO *tso);
+static void printThreadStatus(StgTSO *tso);
+void printThreadQueue(StgTSO *tso);
#endif
-#if DEBUG
-char *whatNext_strs[] = {
- "ThreadEnterGHC",
+#if defined(PARALLEL_HASKELL)
+StgTSO * createSparkThread(rtsSpark spark);
+StgTSO * activateSpark (rtsSpark spark);
+#endif
+
+#ifdef DEBUG
+static char *whatNext_strs[] = {
+ "(unknown)",
"ThreadRunGHC",
- "ThreadEnterInterp",
+ "ThreadInterpret",
"ThreadKilled",
+ "ThreadRelocated",
"ThreadComplete"
};
-
-char *threadReturnCode_strs[] = {
- "HeapOverflow", /* might also be StackOverflow */
- "StackOverflow",
- "ThreadYielding",
- "ThreadBlocked",
- "ThreadFinished"
-};
-#endif
-
-#if defined(PAR)
-StgTSO * createSparkThread(rtsSpark spark);
-StgTSO * activateSpark (rtsSpark spark);
#endif
-/*
- * The thread state for the main thread.
-// ToDo: check whether not needed any more
-StgTSO *MainTSO;
- */
+/* -----------------------------------------------------------------------------
+ * Putting a thread on the run queue: different scheduling policies
+ * -------------------------------------------------------------------------- */
-#if defined(PAR) || defined(RTS_SUPPORTS_THREADS)
-static void taskStart(void);
-static void
-taskStart(void)
+STATIC_INLINE void
+addToRunQueue( Capability *cap, StgTSO *t )
{
- schedule();
-}
+#if defined(PARALLEL_HASKELL)
+ if (RtsFlags.ParFlags.doFairScheduling) {
+ // this does round-robin scheduling; good for concurrency
+ appendToRunQueue(cap,t);
+ } else {
+ // this does unfair scheduling; good for parallelism
+ pushOnRunQueue(cap,t);
+ }
+#else
+ // this does round-robin scheduling; good for concurrency
+ appendToRunQueue(cap,t);
#endif
-
-
-
-
-//@node Main scheduling loop, Suspend and Resume, Prototypes, Main scheduling code
-//@subsection Main scheduling loop
+}
/* ---------------------------------------------------------------------------
Main scheduling loop.
* thread ends
* stack overflow
- Locking notes: we acquire the scheduler lock once at the beginning
- of the scheduler loop, and release it when
-
- * running a thread, or
- * waiting for work, or
- * waiting for a GC to complete.
-
GRAN version:
In a GranSim setup this loop iterates over the global event queue.
This revolves around the global event queue, which determines what
This is not the ugliest code you could imagine, but it's bloody close.
------------------------------------------------------------------------ */
-//@cindex schedule
-static void
-schedule( void )
+
+static Capability *
+schedule (Capability *initialCapability, Task *task)
{
StgTSO *t;
Capability *cap;
StgThreadReturnCode ret;
#if defined(GRAN)
rtsEvent *event;
-#elif defined(PAR)
- StgSparkPool *pool;
- rtsSpark spark;
+#elif defined(PARALLEL_HASKELL)
StgTSO *tso;
GlobalTaskId pe;
rtsBool receivedFinish = rtsFalse;
nat tp_size, sp_size; // stats only
# endif
#endif
- rtsBool was_interrupted = rtsFalse;
-
- ACQUIRE_LOCK(&sched_mutex);
-
-#if defined(RTS_SUPPORTS_THREADS)
- /* Check to see whether there are any worker threads
- waiting to deposit external call results. If so,
- yield our capability */
- yieldToReturningWorker(&sched_mutex, cap);
-
- waitForWorkCapability(&sched_mutex, &cap, rtsFalse);
+ nat prev_what_next;
+ rtsBool ready_to_gc;
+#if defined(THREADED_RTS)
+ rtsBool first = rtsTrue;
#endif
+
+ cap = initialCapability;
-#if defined(GRAN)
- /* set up first event to get things going */
- /* ToDo: assign costs for system setup and init MainTSO ! */
- new_event(CurrentProc, CurrentProc, CurrentTime[CurrentProc],
- ContinueThread,
- CurrentTSO, (StgClosure*)NULL, (rtsSpark*)NULL);
-
- IF_DEBUG(gran,
- fprintf(stderr, "GRAN: Init CurrentTSO (in schedule) = %p\n", CurrentTSO);
- G_TSO(CurrentTSO, 5));
-
- if (RtsFlags.GranFlags.Light) {
- /* Save current time; GranSim Light only */
- CurrentTSO->gran.clock = CurrentTime[CurrentProc];
- }
+ // Pre-condition: this task owns initialCapability.
+ // The sched_mutex is *NOT* held
+ // NB. on return, we still hold a capability.
- event = get_next_event();
+ IF_DEBUG(scheduler,
+ sched_belch("### NEW SCHEDULER LOOP (task: %p, cap: %p)",
+ task, initialCapability);
+ );
- while (event!=(rtsEvent*)NULL) {
- /* Choose the processor with the next event */
- CurrentProc = event->proc;
- CurrentTSO = event->tso;
+ schedulePreLoop();
-#elif defined(PAR)
+ // -----------------------------------------------------------
+ // Scheduler loop starts here:
- while (!receivedFinish) { /* set by processMessages */
- /* when receiving PP_FINISH message */
+#if defined(PARALLEL_HASKELL)
+#define TERMINATION_CONDITION (!receivedFinish)
+#elif defined(GRAN)
+#define TERMINATION_CONDITION ((event = get_next_event()) != (rtsEvent*)NULL)
#else
+#define TERMINATION_CONDITION rtsTrue
+#endif
- while (1) {
+ while (TERMINATION_CONDITION) {
+#if defined(GRAN)
+ /* Choose the processor with the next event */
+ CurrentProc = event->proc;
+ CurrentTSO = event->tso;
#endif
- IF_DEBUG(scheduler, printAllThreads());
+#if defined(THREADED_RTS)
+ if (first) {
+ // don't yield the first time, we want a chance to run this
+ // thread for a bit, even if there are others banging at the
+ // door.
+ first = rtsFalse;
+ ASSERT_FULL_CAPABILITY_INVARIANTS(cap,task);
+ } else {
+ // Yield the capability to higher-priority tasks if necessary.
+ yieldCapability(&cap, task);
+ }
+#endif
+
+#if defined(THREADED_RTS)
+ schedulePushWork(cap,task);
+#endif
- /* If we're interrupted (the user pressed ^C, or some other
- * termination condition occurred), kill all the currently running
- * threads.
- */
- if (interrupted) {
- IF_DEBUG(scheduler, sched_belch("interrupted"));
- deleteAllThreads();
- interrupted = rtsFalse;
- was_interrupted = rtsTrue;
+ // Check whether we have re-entered the RTS from Haskell without
+ // going via suspendThread()/resumeThread (i.e. a 'safe' foreign
+ // call).
+ if (cap->in_haskell) {
+ errorBelch("schedule: re-entered unsafely.\n"
+ " Perhaps a 'foreign import unsafe' should be 'safe'?");
+ stg_exit(EXIT_FAILURE);
}
- /* Go through the list of main threads and wake up any
- * clients whose computations have finished. ToDo: this
- * should be done more efficiently without a linear scan
- * of the main threads list, somehow...
- */
-#if defined(RTS_SUPPORTS_THREADS)
- {
- StgMainThread *m, **prev;
- prev = &main_threads;
- for (m = main_threads; m != NULL; m = m->link) {
- switch (m->tso->what_next) {
- case ThreadComplete:
- if (m->ret) {
- *(m->ret) = (StgClosure *)m->tso->sp[0];
- }
- *prev = m->link;
- m->stat = Success;
- broadcastCondition(&m->wakeup);
- break;
- case ThreadKilled:
- if (m->ret) *(m->ret) = NULL;
- *prev = m->link;
- if (was_interrupted) {
- m->stat = Interrupted;
- } else {
- m->stat = Killed;
- }
- broadcastCondition(&m->wakeup);
- break;
- default:
- break;
+ // The interruption / shutdown sequence.
+ //
+ // In order to cleanly shut down the runtime, we want to:
+ // * make sure that all main threads return to their callers
+ // with the state 'Interrupted'.
+ // * clean up all OS threads assocated with the runtime
+ // * free all memory etc.
+ //
+ // So the sequence for ^C goes like this:
+ //
+ // * ^C handler sets sched_state := SCHED_INTERRUPTING and
+ // arranges for some Capability to wake up
+ //
+ // * all threads in the system are halted, and the zombies are
+ // placed on the run queue for cleaning up. We acquire all
+ // the capabilities in order to delete the threads, this is
+ // done by scheduleDoGC() for convenience (because GC already
+ // needs to acquire all the capabilities). We can't kill
+ // threads involved in foreign calls.
+ //
+ // * sched_state := SCHED_INTERRUPTED
+ //
+ // * somebody calls shutdownHaskell(), which calls exitScheduler()
+ //
+ // * sched_state := SCHED_SHUTTING_DOWN
+ //
+ // * all workers exit when the run queue on their capability
+ // drains. All main threads will also exit when their TSO
+ // reaches the head of the run queue and they can return.
+ //
+ // * eventually all Capabilities will shut down, and the RTS can
+ // exit.
+ //
+ // * We might be left with threads blocked in foreign calls,
+ // we should really attempt to kill these somehow (TODO);
+
+ switch (sched_state) {
+ case SCHED_RUNNING:
+ break;
+ case SCHED_INTERRUPTING:
+ IF_DEBUG(scheduler, sched_belch("SCHED_INTERRUPTING"));
+#if defined(THREADED_RTS)
+ discardSparksCap(cap);
+#endif
+ /* scheduleDoGC() deletes all the threads */
+ cap = scheduleDoGC(cap,task,rtsFalse,GetRoots);
+ break;
+ case SCHED_INTERRUPTED:
+ IF_DEBUG(scheduler, sched_belch("SCHED_INTERRUPTED"));
+ break;
+ case SCHED_SHUTTING_DOWN:
+ IF_DEBUG(scheduler, sched_belch("SCHED_SHUTTING_DOWN"));
+ // If we are a worker, just exit. If we're a bound thread
+ // then we will exit below when we've removed our TSO from
+ // the run queue.
+ if (task->tso == NULL && emptyRunQueue(cap)) {
+ return cap;
}
- }
+ break;
+ default:
+ barf("sched_state: %d", sched_state);
}
-#else /* not threaded */
-
-# if defined(PAR)
- /* in GUM do this only on the Main PE */
- if (IAmMainThread)
-# endif
- /* If our main thread has finished or been killed, return.
- */
+#if defined(THREADED_RTS)
+ // If the run queue is empty, take a spark and turn it into a thread.
{
- StgMainThread *m = main_threads;
- if (m->tso->what_next == ThreadComplete
- || m->tso->what_next == ThreadKilled) {
- main_threads = main_threads->link;
- if (m->tso->what_next == ThreadComplete) {
- /* we finished successfully, fill in the return value */
- if (m->ret) { *(m->ret) = (StgClosure *)m->tso->sp[0]; };
- m->stat = Success;
- return;
- } else {
- if (m->ret) { *(m->ret) = NULL; };
- if (was_interrupted) {
- m->stat = Interrupted;
- } else {
- m->stat = Killed;
- }
- return;
+ if (emptyRunQueue(cap)) {
+ StgClosure *spark;
+ spark = findSpark(cap);
+ if (spark != NULL) {
+ IF_DEBUG(scheduler,
+ sched_belch("turning spark of closure %p into a thread",
+ (StgClosure *)spark));
+ createSparkThread(cap,spark);
+ }
}
- }
}
-#endif
+#endif // THREADED_RTS
- /* Top up the run queue from our spark pool. We try to make the
- * number of threads in the run queue equal to the number of
- * free capabilities.
- *
- * Disable spark support in SMP for now, non-essential & requires
- * a little bit of work to make it compile cleanly. -- sof 1/02.
- */
-#if 0 /* defined(SMP) */
- {
- nat n = getFreeCapabilities();
- StgTSO *tso = run_queue_hd;
+ scheduleStartSignalHandlers(cap);
- /* Count the run queue */
- while (n > 0 && tso != END_TSO_QUEUE) {
- tso = tso->link;
- n--;
- }
+ // Only check the black holes here if we've nothing else to do.
+ // During normal execution, the black hole list only gets checked
+ // at GC time, to avoid repeatedly traversing this possibly long
+ // list each time around the scheduler.
+ if (emptyRunQueue(cap)) { scheduleCheckBlackHoles(cap); }
- for (; n > 0; n--) {
- StgClosure *spark;
- spark = findSpark(rtsFalse);
- if (spark == NULL) {
- break; /* no more sparks in the pool */
- } else {
- /* I'd prefer this to be done in activateSpark -- HWL */
- /* tricky - it needs to hold the scheduler lock and
- * not try to re-acquire it -- SDM */
- createSparkThread(spark);
- IF_DEBUG(scheduler,
- sched_belch("==^^ turning spark of closure %p into a thread",
- (StgClosure *)spark));
- }
- }
- /* We need to wake up the other tasks if we just created some
- * work for them.
- */
- if (getFreeCapabilities() - n > 1) {
- signalCondition( &thread_ready_cond );
- }
- }
-#endif // SMP
+ scheduleCheckBlockedThreads(cap);
- /* check for signals each time around the scheduler */
-#ifndef mingw32_TARGET_OS
- if (signals_pending()) {
- startSignalHandlers();
- }
+ scheduleDetectDeadlock(cap,task);
+#if defined(THREADED_RTS)
+ cap = task->cap; // reload cap, it might have changed
#endif
- /* Check whether any waiting threads need to be woken up. If the
- * run queue is empty, and there are no other tasks running, we
- * can wait indefinitely for something to happen.
- * ToDo: what if another client comes along & requests another
- * main thread?
- */
- if ( !EMPTY_QUEUE(blocked_queue_hd) || !EMPTY_QUEUE(sleeping_queue) ) {
- awaitEvent( EMPTY_RUN_QUEUE()
-#if defined(SMP)
- && allFreeCapabilities()
+ // Normally, the only way we can get here with no threads to
+ // run is if a keyboard interrupt received during
+ // scheduleCheckBlockedThreads() or scheduleDetectDeadlock().
+ // Additionally, it is not fatal for the
+ // threaded RTS to reach here with no threads to run.
+ //
+ // win32: might be here due to awaitEvent() being abandoned
+ // as a result of a console event having been delivered.
+ if ( emptyRunQueue(cap) ) {
+#if !defined(THREADED_RTS) && !defined(mingw32_HOST_OS)
+ ASSERT(sched_state >= SCHED_INTERRUPTING);
#endif
- );
+ continue; // nothing to do
}
- /* we can be interrupted while waiting for I/O... */
- if (interrupted) continue;
-
- /*
- * Detect deadlock: when we have no threads to run, there are no
- * threads waiting on I/O or sleeping, and all the other tasks are
- * waiting for work, we must have a deadlock of some description.
- *
- * We first try to find threads blocked on themselves (ie. black
- * holes), and generate NonTermination exceptions where necessary.
- *
- * If no threads are black holed, we have a deadlock situation, so
- * inform all the main threads.
- */
-#ifndef PAR
- if ( EMPTY_THREAD_QUEUES()
-#if defined(RTS_SUPPORTS_THREADS)
- && EMPTY_QUEUE(suspended_ccalling_threads)
-#endif
-#ifdef SMP
- && allFreeCapabilities()
-#endif
- )
- {
- IF_DEBUG(scheduler, sched_belch("deadlocked, forcing major GC..."));
-#if defined(THREADED_RTS)
- /* and SMP mode ..? */
- releaseCapability(cap);
-#endif
- // Garbage collection can release some new threads due to
- // either (a) finalizers or (b) threads resurrected because
- // they are about to be send BlockedOnDeadMVar. Any threads
- // thus released will be immediately runnable.
- GarbageCollect(GetRoots,rtsTrue);
-
- if ( !EMPTY_RUN_QUEUE() ) { goto not_deadlocked; }
- IF_DEBUG(scheduler,
- sched_belch("still deadlocked, checking for black holes..."));
- detectBlackHoles();
+#if defined(PARALLEL_HASKELL)
+ scheduleSendPendingMessages();
+ if (emptyRunQueue(cap) && scheduleActivateSpark())
+ continue;
- if ( !EMPTY_RUN_QUEUE() ) { goto not_deadlocked; }
+#if defined(SPARKS)
+ ASSERT(next_fish_to_send_at==0); // i.e. no delayed fishes left!
+#endif
-#ifndef mingw32_TARGET_OS
- /* If we have user-installed signal handlers, then wait
- * for signals to arrive rather then bombing out with a
- * deadlock.
- */
- if ( anyUserHandlers() ) {
- IF_DEBUG(scheduler,
- sched_belch("still deadlocked, waiting for signals..."));
+ /* If we still have no work we need to send a FISH to get a spark
+ from another PE */
+ if (emptyRunQueue(cap)) {
+ if (!scheduleGetRemoteWork(&receivedFinish)) continue;
+ ASSERT(rtsFalse); // should not happen at the moment
+ }
+ // from here: non-empty run queue.
+ // TODO: merge above case with this, only one call processMessages() !
+ if (PacketsWaiting()) { /* process incoming messages, if
+ any pending... only in else
+ because getRemoteWork waits for
+ messages as well */
+ receivedFinish = processMessages();
+ }
+#endif
- awaitUserSignals();
+#if defined(GRAN)
+ scheduleProcessEvent(event);
+#endif
- // we might be interrupted...
- if (interrupted) { continue; }
+ //
+ // Get a thread to run
+ //
+ t = popRunQueue(cap);
- if (signals_pending()) {
- startSignalHandlers();
- }
- ASSERT(!EMPTY_RUN_QUEUE());
- goto not_deadlocked;
- }
+#if defined(GRAN) || defined(PAR)
+ scheduleGranParReport(); // some kind of debuging output
+#else
+ // Sanity check the thread we're about to run. This can be
+ // expensive if there is lots of thread switching going on...
+ IF_DEBUG(sanity,checkTSO(t));
#endif
- /* Probably a real deadlock. Send the current main thread the
- * Deadlock exception (or in the SMP build, send *all* main
- * threads the deadlock exception, since none of them can make
- * progress).
- */
- {
- StgMainThread *m;
-#if defined(RTS_SUPPORTS_THREADS)
- for (m = main_threads; m != NULL; m = m->link) {
- switch (m->tso->why_blocked) {
- case BlockedOnBlackHole:
- raiseAsync(m->tso, (StgClosure *)NonTermination_closure);
- break;
- case BlockedOnException:
- case BlockedOnMVar:
- raiseAsync(m->tso, (StgClosure *)Deadlock_closure);
- break;
- default:
- barf("deadlock: main thread blocked in a strange way");
- }
+#if defined(THREADED_RTS)
+ // Check whether we can run this thread in the current task.
+ // If not, we have to pass our capability to the right task.
+ {
+ Task *bound = t->bound;
+
+ if (bound) {
+ if (bound == task) {
+ IF_DEBUG(scheduler,
+ sched_belch("### Running thread %d in bound thread",
+ t->id));
+ // yes, the Haskell thread is bound to the current native thread
+ } else {
+ IF_DEBUG(scheduler,
+ sched_belch("### thread %d bound to another OS thread",
+ t->id));
+ // no, bound to a different Haskell thread: pass to that thread
+ pushOnRunQueue(cap,t);
+ continue;
}
-#else
- m = main_threads;
- switch (m->tso->why_blocked) {
- case BlockedOnBlackHole:
- raiseAsync(m->tso, (StgClosure *)NonTermination_closure);
- break;
- case BlockedOnException:
- case BlockedOnMVar:
- raiseAsync(m->tso, (StgClosure *)Deadlock_closure);
- break;
- default:
- barf("deadlock: main thread blocked in a strange way");
+ } else {
+ // The thread we want to run is unbound.
+ if (task->tso) {
+ IF_DEBUG(scheduler,
+ sched_belch("### this OS thread cannot run thread %d", t->id));
+ // no, the current native thread is bound to a different
+ // Haskell thread, so pass it to any worker thread
+ pushOnRunQueue(cap,t);
+ continue;
}
-#endif
}
-
-#if defined(RTS_SUPPORTS_THREADS)
- /* ToDo: revisit conditions (and mechanism) for shutting
- down a multi-threaded world */
- IF_DEBUG(scheduler, sched_belch("all done, i think...shutting down."));
- shutdownHaskellAndExit(0);
-#endif
}
- not_deadlocked:
-
-#elif defined(PAR)
- /* ToDo: add deadlock detection in GUM (similar to SMP) -- HWL */
#endif
-#if defined(SMP)
- /* If there's a GC pending, don't do anything until it has
- * completed.
+ cap->r.rCurrentTSO = t;
+
+ /* context switches are initiated by the timer signal, unless
+ * the user specified "context switch as often as possible", with
+ * +RTS -C0
*/
- if (ready_to_gc) {
- IF_DEBUG(scheduler,sched_belch("waiting for GC"));
- waitCondition( &gc_pending_cond, &sched_mutex );
+ if (RtsFlags.ConcFlags.ctxtSwitchTicks == 0
+ && !emptyThreadQueues(cap)) {
+ context_switch = 1;
}
-#endif
+
+run_thread:
-#if defined(RTS_SUPPORTS_THREADS)
- /* block until we've got a thread on the run queue and a free
- * capability.
- *
- */
- if ( EMPTY_RUN_QUEUE() ) {
- /* Give up our capability */
- releaseCapability(cap);
- IF_DEBUG(scheduler, sched_belch("thread %d: waiting for work", osThreadId()));
- waitForWorkCapability(&sched_mutex, &cap, rtsTrue);
- IF_DEBUG(scheduler, sched_belch("thread %d: work now available", osThreadId()));
-#if 0
- while ( EMPTY_RUN_QUEUE() ) {
- waitForWorkCapability(&sched_mutex, &cap);
- IF_DEBUG(scheduler, sched_belch("thread %d: work now available", osThreadId()));
- }
-#endif
- }
+ IF_DEBUG(scheduler, sched_belch("-->> running thread %ld %s ...",
+ (long)t->id, whatNext_strs[t->what_next]));
+
+#if defined(PROFILING)
+ startHeapProfTimer();
#endif
-#if defined(GRAN)
- if (RtsFlags.GranFlags.Light)
- GranSimLight_enter_system(event, &ActiveTSO); // adjust ActiveTSO etc
+ // ----------------------------------------------------------------------
+ // Run the current thread
- /* adjust time based on time-stamp */
- if (event->time > CurrentTime[CurrentProc] &&
- event->evttype != ContinueThread)
- CurrentTime[CurrentProc] = event->time;
-
+ ASSERT_FULL_CAPABILITY_INVARIANTS(cap,task);
+
+ prev_what_next = t->what_next;
+
+ errno = t->saved_errno;
+ cap->in_haskell = rtsTrue;
+
+ dirtyTSO(t);
+
+ recent_activity = ACTIVITY_YES;
+
+ switch (prev_what_next) {
+
+ case ThreadKilled:
+ case ThreadComplete:
+ /* Thread already finished, return to scheduler. */
+ ret = ThreadFinished;
+ break;
+
+ case ThreadRunGHC:
+ {
+ StgRegTable *r;
+ r = StgRun((StgFunPtr) stg_returnToStackTop, &cap->r);
+ cap = regTableToCapability(r);
+ ret = r->rRet;
+ break;
+ }
+
+ case ThreadInterpret:
+ cap = interpretBCO(cap);
+ ret = cap->r.rRet;
+ break;
+
+ default:
+ barf("schedule: invalid what_next field");
+ }
+
+ cap->in_haskell = rtsFalse;
+
+ // The TSO might have moved, eg. if it re-entered the RTS and a GC
+ // happened. So find the new location:
+ t = cap->r.rCurrentTSO;
+
+ // We have run some Haskell code: there might be blackhole-blocked
+ // threads to wake up now.
+ // Lock-free test here should be ok, we're just setting a flag.
+ if ( blackhole_queue != END_TSO_QUEUE ) {
+ blackholes_need_checking = rtsTrue;
+ }
+
+ // And save the current errno in this thread.
+ // XXX: possibly bogus for SMP because this thread might already
+ // be running again, see code below.
+ t->saved_errno = errno;
+
+#if defined(THREADED_RTS)
+ // If ret is ThreadBlocked, and this Task is bound to the TSO that
+ // blocked, we are in limbo - the TSO is now owned by whatever it
+ // is blocked on, and may in fact already have been woken up,
+ // perhaps even on a different Capability. It may be the case
+ // that task->cap != cap. We better yield this Capability
+ // immediately and return to normaility.
+ if (ret == ThreadBlocked) {
+ IF_DEBUG(scheduler,
+ sched_belch("--<< thread %d (%s) stopped: blocked\n",
+ t->id, whatNext_strs[t->what_next]));
+ continue;
+ }
+#endif
+
+ ASSERT_FULL_CAPABILITY_INVARIANTS(cap,task);
+
+ // ----------------------------------------------------------------------
+
+ // Costs for the scheduler are assigned to CCS_SYSTEM
+#if defined(PROFILING)
+ stopHeapProfTimer();
+ CCCS = CCS_SYSTEM;
+#endif
+
+#if defined(THREADED_RTS)
+ IF_DEBUG(scheduler,debugBelch("sched (task %p): ", (void *)(unsigned long)(unsigned int)osThreadId()););
+#elif !defined(GRAN) && !defined(PARALLEL_HASKELL)
+ IF_DEBUG(scheduler,debugBelch("sched: "););
+#endif
+
+ schedulePostRunThread();
+
+ ready_to_gc = rtsFalse;
+
+ switch (ret) {
+ case HeapOverflow:
+ ready_to_gc = scheduleHandleHeapOverflow(cap,t);
+ break;
+
+ case StackOverflow:
+ scheduleHandleStackOverflow(cap,task,t);
+ break;
+
+ case ThreadYielding:
+ if (scheduleHandleYield(cap, t, prev_what_next)) {
+ // shortcut for switching between compiler/interpreter:
+ goto run_thread;
+ }
+ break;
+
+ case ThreadBlocked:
+ scheduleHandleThreadBlocked(t);
+ break;
+
+ case ThreadFinished:
+ if (scheduleHandleThreadFinished(cap, task, t)) return cap;
+ ASSERT_FULL_CAPABILITY_INVARIANTS(cap,task);
+ break;
+
+ default:
+ barf("schedule: invalid thread return code %d", (int)ret);
+ }
+
+ if (scheduleDoHeapProfile(ready_to_gc)) { ready_to_gc = rtsFalse; }
+ if (ready_to_gc) {
+ cap = scheduleDoGC(cap,task,rtsFalse,GetRoots);
+ }
+ } /* end of while() */
+
+ IF_PAR_DEBUG(verbose,
+ debugBelch("== Leaving schedule() after having received Finish\n"));
+}
+
+/* ----------------------------------------------------------------------------
+ * Setting up the scheduler loop
+ * ------------------------------------------------------------------------- */
+
+static void
+schedulePreLoop(void)
+{
+#if defined(GRAN)
+ /* set up first event to get things going */
+ /* ToDo: assign costs for system setup and init MainTSO ! */
+ new_event(CurrentProc, CurrentProc, CurrentTime[CurrentProc],
+ ContinueThread,
+ CurrentTSO, (StgClosure*)NULL, (rtsSpark*)NULL);
+
+ IF_DEBUG(gran,
+ debugBelch("GRAN: Init CurrentTSO (in schedule) = %p\n",
+ CurrentTSO);
+ G_TSO(CurrentTSO, 5));
+
+ if (RtsFlags.GranFlags.Light) {
+ /* Save current time; GranSim Light only */
+ CurrentTSO->gran.clock = CurrentTime[CurrentProc];
+ }
+#endif
+}
+
+/* -----------------------------------------------------------------------------
+ * schedulePushWork()
+ *
+ * Push work to other Capabilities if we have some.
+ * -------------------------------------------------------------------------- */
+
+#if defined(THREADED_RTS)
+static void
+schedulePushWork(Capability *cap USED_IF_THREADS,
+ Task *task USED_IF_THREADS)
+{
+ Capability *free_caps[n_capabilities], *cap0;
+ nat i, n_free_caps;
+
+ // Check whether we have more threads on our run queue, or sparks
+ // in our pool, that we could hand to another Capability.
+ if ((emptyRunQueue(cap) || cap->run_queue_hd->link == END_TSO_QUEUE)
+ && sparkPoolSizeCap(cap) < 2) {
+ return;
+ }
+
+ // First grab as many free Capabilities as we can.
+ for (i=0, n_free_caps=0; i < n_capabilities; i++) {
+ cap0 = &capabilities[i];
+ if (cap != cap0 && tryGrabCapability(cap0,task)) {
+ if (!emptyRunQueue(cap0) || cap->returning_tasks_hd != NULL) {
+ // it already has some work, we just grabbed it at
+ // the wrong moment. Or maybe it's deadlocked!
+ releaseCapability(cap0);
+ } else {
+ free_caps[n_free_caps++] = cap0;
+ }
+ }
+ }
+
+ // we now have n_free_caps free capabilities stashed in
+ // free_caps[]. Share our run queue equally with them. This is
+ // probably the simplest thing we could do; improvements we might
+ // want to do include:
+ //
+ // - giving high priority to moving relatively new threads, on
+ // the gournds that they haven't had time to build up a
+ // working set in the cache on this CPU/Capability.
+ //
+ // - giving low priority to moving long-lived threads
+
+ if (n_free_caps > 0) {
+ StgTSO *prev, *t, *next;
+ rtsBool pushed_to_all;
+
+ IF_DEBUG(scheduler, sched_belch("excess threads on run queue and %d free capabilities, sharing...", n_free_caps));
+
+ i = 0;
+ pushed_to_all = rtsFalse;
+
+ if (cap->run_queue_hd != END_TSO_QUEUE) {
+ prev = cap->run_queue_hd;
+ t = prev->link;
+ prev->link = END_TSO_QUEUE;
+ for (; t != END_TSO_QUEUE; t = next) {
+ next = t->link;
+ t->link = END_TSO_QUEUE;
+ if (t->what_next == ThreadRelocated
+ || t->bound == task) { // don't move my bound thread
+ prev->link = t;
+ prev = t;
+ } else if (i == n_free_caps) {
+ pushed_to_all = rtsTrue;
+ i = 0;
+ // keep one for us
+ prev->link = t;
+ prev = t;
+ } else {
+ IF_DEBUG(scheduler, sched_belch("pushing thread %d to capability %d", t->id, free_caps[i]->no));
+ appendToRunQueue(free_caps[i],t);
+ if (t->bound) { t->bound->cap = free_caps[i]; }
+ i++;
+ }
+ }
+ cap->run_queue_tl = prev;
+ }
+
+ // If there are some free capabilities that we didn't push any
+ // threads to, then try to push a spark to each one.
+ if (!pushed_to_all) {
+ StgClosure *spark;
+ // i is the next free capability to push to
+ for (; i < n_free_caps; i++) {
+ if (emptySparkPoolCap(free_caps[i])) {
+ spark = findSpark(cap);
+ if (spark != NULL) {
+ IF_DEBUG(scheduler, sched_belch("pushing spark %p to capability %d", spark, free_caps[i]->no));
+ newSpark(&(free_caps[i]->r), spark);
+ }
+ }
+ }
+ }
+
+ // release the capabilities
+ for (i = 0; i < n_free_caps; i++) {
+ task->cap = free_caps[i];
+ releaseCapability(free_caps[i]);
+ }
+ }
+ task->cap = cap; // reset to point to our Capability.
+}
+#endif
+
+/* ----------------------------------------------------------------------------
+ * Start any pending signal handlers
+ * ------------------------------------------------------------------------- */
+
+#if defined(RTS_USER_SIGNALS) && (!defined(THREADED_RTS) || defined(mingw32_HOST_OS))
+static void
+scheduleStartSignalHandlers(Capability *cap)
+{
+ if (signals_pending()) { // safe outside the lock
+ startSignalHandlers(cap);
+ }
+}
+#else
+static void
+scheduleStartSignalHandlers(Capability *cap STG_UNUSED)
+{
+}
+#endif
+
+/* ----------------------------------------------------------------------------
+ * Check for blocked threads that can be woken up.
+ * ------------------------------------------------------------------------- */
+
+static void
+scheduleCheckBlockedThreads(Capability *cap USED_IF_NOT_THREADS)
+{
+#if !defined(THREADED_RTS)
+ //
+ // Check whether any waiting threads need to be woken up. If the
+ // run queue is empty, and there are no other tasks running, we
+ // can wait indefinitely for something to happen.
+ //
+ if ( !emptyQueue(blocked_queue_hd) || !emptyQueue(sleeping_queue) )
+ {
+ awaitEvent( emptyRunQueue(cap) && !blackholes_need_checking );
+ }
+#endif
+}
+
+
+/* ----------------------------------------------------------------------------
+ * Check for threads blocked on BLACKHOLEs that can be woken up
+ * ------------------------------------------------------------------------- */
+static void
+scheduleCheckBlackHoles (Capability *cap)
+{
+ if ( blackholes_need_checking ) // check without the lock first
+ {
+ ACQUIRE_LOCK(&sched_mutex);
+ if ( blackholes_need_checking ) {
+ checkBlackHoles(cap);
+ blackholes_need_checking = rtsFalse;
+ }
+ RELEASE_LOCK(&sched_mutex);
+ }
+}
+
+/* ----------------------------------------------------------------------------
+ * Detect deadlock conditions and attempt to resolve them.
+ * ------------------------------------------------------------------------- */
+
+static void
+scheduleDetectDeadlock (Capability *cap, Task *task)
+{
+
+#if defined(PARALLEL_HASKELL)
+ // ToDo: add deadlock detection in GUM (similar to THREADED_RTS) -- HWL
+ return;
+#endif
+
+ /*
+ * Detect deadlock: when we have no threads to run, there are no
+ * threads blocked, waiting for I/O, or sleeping, and all the
+ * other tasks are waiting for work, we must have a deadlock of
+ * some description.
+ */
+ if ( emptyThreadQueues(cap) )
+ {
+#if defined(THREADED_RTS)
+ /*
+ * In the threaded RTS, we only check for deadlock if there
+ * has been no activity in a complete timeslice. This means
+ * we won't eagerly start a full GC just because we don't have
+ * any threads to run currently.
+ */
+ if (recent_activity != ACTIVITY_INACTIVE) return;
+#endif
+
+ IF_DEBUG(scheduler, sched_belch("deadlocked, forcing major GC..."));
+
+ // Garbage collection can release some new threads due to
+ // either (a) finalizers or (b) threads resurrected because
+ // they are unreachable and will therefore be sent an
+ // exception. Any threads thus released will be immediately
+ // runnable.
+ cap = scheduleDoGC (cap, task, rtsTrue/*force major GC*/, GetRoots);
+
+ recent_activity = ACTIVITY_DONE_GC;
+
+ if ( !emptyRunQueue(cap) ) return;
+
+#if defined(RTS_USER_SIGNALS) && (!defined(THREADED_RTS) || defined(mingw32_HOST_OS))
+ /* If we have user-installed signal handlers, then wait
+ * for signals to arrive rather then bombing out with a
+ * deadlock.
+ */
+ if ( anyUserHandlers() ) {
+ IF_DEBUG(scheduler,
+ sched_belch("still deadlocked, waiting for signals..."));
+
+ awaitUserSignals();
+
+ if (signals_pending()) {
+ startSignalHandlers(cap);
+ }
+
+ // either we have threads to run, or we were interrupted:
+ ASSERT(!emptyRunQueue(cap) || sched_state >= SCHED_INTERRUPTING);
+ }
+#endif
+
+#if !defined(THREADED_RTS)
+ /* Probably a real deadlock. Send the current main thread the
+ * Deadlock exception.
+ */
+ if (task->tso) {
+ switch (task->tso->why_blocked) {
+ case BlockedOnSTM:
+ case BlockedOnBlackHole:
+ case BlockedOnException:
+ case BlockedOnMVar:
+ raiseAsync(cap, task->tso, (StgClosure *)NonTermination_closure);
+ return;
+ default:
+ barf("deadlock: main thread blocked in a strange way");
+ }
+ }
+ return;
+#endif
+ }
+}
+
+/* ----------------------------------------------------------------------------
+ * Process an event (GRAN only)
+ * ------------------------------------------------------------------------- */
+
+#if defined(GRAN)
+static StgTSO *
+scheduleProcessEvent(rtsEvent *event)
+{
+ StgTSO *t;
+
+ if (RtsFlags.GranFlags.Light)
+ GranSimLight_enter_system(event, &ActiveTSO); // adjust ActiveTSO etc
+
+ /* adjust time based on time-stamp */
+ if (event->time > CurrentTime[CurrentProc] &&
+ event->evttype != ContinueThread)
+ CurrentTime[CurrentProc] = event->time;
+
/* Deal with the idle PEs (may issue FindWork or MoveSpark events) */
if (!RtsFlags.GranFlags.Light)
handleIdlePEs();
- IF_DEBUG(gran, fprintf(stderr, "GRAN: switch by event-type\n"));
+ IF_DEBUG(gran, debugBelch("GRAN: switch by event-type\n"));
/* main event dispatcher in GranSim */
switch (event->evttype) {
/* Should just be continuing execution */
case ContinueThread:
- IF_DEBUG(gran, fprintf(stderr, "GRAN: doing ContinueThread\n"));
+ IF_DEBUG(gran, debugBelch("GRAN: doing ContinueThread\n"));
/* ToDo: check assertion
ASSERT(run_queue_hd != (StgTSO*)NULL &&
run_queue_hd != END_TSO_QUEUE);
/* Ignore ContinueThreads for fetching threads (if synchr comm) */
if (!RtsFlags.GranFlags.DoAsyncFetch &&
procStatus[CurrentProc]==Fetching) {
- belch("ghuH: Spurious ContinueThread while Fetching ignored; TSO %d (%p) [PE %d]",
+ debugBelch("ghuH: Spurious ContinueThread while Fetching ignored; TSO %d (%p) [PE %d]\n",
CurrentTSO->id, CurrentTSO, CurrentProc);
goto next_thread;
}
/* Ignore ContinueThreads for completed threads */
if (CurrentTSO->what_next == ThreadComplete) {
- belch("ghuH: found a ContinueThread event for completed thread %d (%p) [PE %d] (ignoring ContinueThread)",
+ debugBelch("ghuH: found a ContinueThread event for completed thread %d (%p) [PE %d] (ignoring ContinueThread)\n",
CurrentTSO->id, CurrentTSO, CurrentProc);
goto next_thread;
}
/* Ignore ContinueThreads for threads that are being migrated */
if (PROCS(CurrentTSO)==Nowhere) {
- belch("ghuH: trying to run the migrating TSO %d (%p) [PE %d] (ignoring ContinueThread)",
+ debugBelch("ghuH: trying to run the migrating TSO %d (%p) [PE %d] (ignoring ContinueThread)\n",
CurrentTSO->id, CurrentTSO, CurrentProc);
goto next_thread;
}
/* The thread should be at the beginning of the run queue */
if (CurrentTSO!=run_queue_hds[CurrentProc]) {
- belch("ghuH: TSO %d (%p) [PE %d] is not at the start of the run_queue when doing a ContinueThread",
+ debugBelch("ghuH: TSO %d (%p) [PE %d] is not at the start of the run_queue when doing a ContinueThread\n",
CurrentTSO->id, CurrentTSO, CurrentProc);
break; // run the thread anyway
}
/* This point was scheduler_loop in the old RTS */
- IF_DEBUG(gran, belch("GRAN: after main switch"));
+ IF_DEBUG(gran, debugBelch("GRAN: after main switch\n"));
TimeOfLastEvent = CurrentTime[CurrentProc];
TimeOfNextEvent = get_time_of_next_event();
IgnoreEvents=(TimeOfNextEvent==0); // HWL HACK
// CurrentTSO = ThreadQueueHd;
- IF_DEBUG(gran, belch("GRAN: time of next event is: %ld",
+ IF_DEBUG(gran, debugBelch("GRAN: time of next event is: %ld\n",
TimeOfNextEvent));
if (RtsFlags.GranFlags.Light)
EndOfTimeSlice = CurrentTime[CurrentProc]+RtsFlags.GranFlags.time_slice;
IF_DEBUG(gran,
- belch("GRAN: end of time-slice is %#lx", EndOfTimeSlice));
+ debugBelch("GRAN: end of time-slice is %#lx\n", EndOfTimeSlice));
/* in a GranSim setup the TSO stays on the run queue */
t = CurrentTSO;
/* Take a thread from the run queue. */
- t = POP_RUN_QUEUE(); // take_off_run_queue(t);
+ POP_RUN_QUEUE(t); // take_off_run_queue(t);
IF_DEBUG(gran,
- fprintf(stderr, "GRAN: About to run current thread, which is\n");
+ debugBelch("GRAN: About to run current thread, which is\n");
G_TSO(t,5));
context_switch = 0; // turned on via GranYield, checking events and time slice
DumpGranEvent(GR_SCHEDULE, t));
procStatus[CurrentProc] = Busy;
+}
+#endif // GRAN
-#elif defined(PAR)
+/* ----------------------------------------------------------------------------
+ * Send pending messages (PARALLEL_HASKELL only)
+ * ------------------------------------------------------------------------- */
+
+#if defined(PARALLEL_HASKELL)
+static StgTSO *
+scheduleSendPendingMessages(void)
+{
+ StgSparkPool *pool;
+ rtsSpark spark;
+ StgTSO *t;
+
+# if defined(PAR) // global Mem.Mgmt., omit for now
if (PendingFetches != END_BF_QUEUE) {
processFetches();
}
+# endif
+
+ if (RtsFlags.ParFlags.BufferTime) {
+ // if we use message buffering, we must send away all message
+ // packets which have become too old...
+ sendOldBuffers();
+ }
+}
+#endif
+
+/* ----------------------------------------------------------------------------
+ * Activate spark threads (PARALLEL_HASKELL only)
+ * ------------------------------------------------------------------------- */
+
+#if defined(PARALLEL_HASKELL)
+static void
+scheduleActivateSpark(void)
+{
+#if defined(SPARKS)
+ ASSERT(emptyRunQueue());
+/* We get here if the run queue is empty and want some work.
+ We try to turn a spark into a thread, and add it to the run queue,
+ from where it will be picked up in the next iteration of the scheduler
+ loop.
+*/
- /* ToDo: phps merge with spark activation above */
- /* check whether we have local work and send requests if we have none */
- if (EMPTY_RUN_QUEUE()) { /* no runnable threads */
/* :-[ no local threads => look out for local sparks */
/* the spark pool for the current PE */
- pool = &(MainRegTable.rSparks); // generalise to cap = &MainRegTable
+ pool = &(cap.r.rSparks); // JB: cap = (old) MainCap
if (advisory_thread_count < RtsFlags.ParFlags.maxThreads &&
pool->hd < pool->tl) {
/*
* thread...
*/
- spark = findSpark(rtsFalse); /* get a spark */
- if (spark != (rtsSpark) NULL) {
- tso = activateSpark(spark); /* turn the spark into a thread */
- IF_PAR_DEBUG(schedule,
- belch("==== schedule: Created TSO %d (%p); %d threads active",
- tso->id, tso, advisory_thread_count));
-
- if (tso==END_TSO_QUEUE) { /* failed to activate spark->back to loop */
- belch("==^^ failed to activate spark");
- goto next_thread;
- } /* otherwise fall through & pick-up new tso */
- } else {
- IF_PAR_DEBUG(verbose,
- belch("==^^ no local sparks (spark pool contains only NFs: %d)",
- spark_queue_len(pool)));
- goto next_thread;
+ spark = findSpark(rtsFalse); /* get a spark */
+ if (spark != (rtsSpark) NULL) {
+ tso = createThreadFromSpark(spark); /* turn the spark into a thread */
+ IF_PAR_DEBUG(fish, // schedule,
+ debugBelch("==== schedule: Created TSO %d (%p); %d threads active\n",
+ tso->id, tso, advisory_thread_count));
+
+ if (tso==END_TSO_QUEUE) { /* failed to activate spark->back to loop */
+ IF_PAR_DEBUG(fish, // schedule,
+ debugBelch("==^^ failed to create thread from spark @ %lx\n",
+ spark));
+ return rtsFalse; /* failed to generate a thread */
+ } /* otherwise fall through & pick-up new tso */
+ } else {
+ IF_PAR_DEBUG(fish, // schedule,
+ debugBelch("==^^ no local sparks (spark pool contains only NFs: %d)\n",
+ spark_queue_len(pool)));
+ return rtsFalse; /* failed to generate a thread */
+ }
+ return rtsTrue; /* success in generating a thread */
+ } else { /* no more threads permitted or pool empty */
+ return rtsFalse; /* failed to generateThread */
+ }
+#else
+ tso = NULL; // avoid compiler warning only
+ return rtsFalse; /* dummy in non-PAR setup */
+#endif // SPARKS
+}
+#endif // PARALLEL_HASKELL
+
+/* ----------------------------------------------------------------------------
+ * Get work from a remote node (PARALLEL_HASKELL only)
+ * ------------------------------------------------------------------------- */
+
+#if defined(PARALLEL_HASKELL)
+static rtsBool
+scheduleGetRemoteWork(rtsBool *receivedFinish)
+{
+ ASSERT(emptyRunQueue());
+
+ if (RtsFlags.ParFlags.BufferTime) {
+ IF_PAR_DEBUG(verbose,
+ debugBelch("...send all pending data,"));
+ {
+ nat i;
+ for (i=1; i<=nPEs; i++)
+ sendImmediately(i); // send all messages away immediately
}
- }
+ }
+# ifndef SPARKS
+ //++EDEN++ idle() , i.e. send all buffers, wait for work
+ // suppress fishing in EDEN... just look for incoming messages
+ // (blocking receive)
+ IF_PAR_DEBUG(verbose,
+ debugBelch("...wait for incoming messages...\n"));
+ *receivedFinish = processMessages(); // blocking receive...
+
+ // and reenter scheduling loop after having received something
+ // (return rtsFalse below)
+
+# else /* activate SPARKS machinery */
+/* We get here, if we have no work, tried to activate a local spark, but still
+ have no work. We try to get a remote spark, by sending a FISH message.
+ Thread migration should be added here, and triggered when a sequence of
+ fishes returns without work. */
+ delay = (RtsFlags.ParFlags.fishDelay!=0ll ? RtsFlags.ParFlags.fishDelay : 0ll);
- /* If we still have no work we need to send a FISH to get a spark
- from another PE
- */
- if (EMPTY_RUN_QUEUE()) {
/* =8-[ no local sparks => look for work on other PEs */
/*
* We really have absolutely no work. Send out a fish
* we're hoping to see. (Of course, we still have to
* respond to other types of messages.)
*/
- TIME now = msTime() /*CURRENT_TIME*/;
+ rtsTime now = msTime() /*CURRENT_TIME*/;
IF_PAR_DEBUG(verbose,
- belch("-- now=%ld", now));
- IF_PAR_DEBUG(verbose,
- if (outstandingFishes < RtsFlags.ParFlags.maxFishes &&
- (last_fish_arrived_at!=0 &&
- last_fish_arrived_at+RtsFlags.ParFlags.fishDelay > now)) {
- belch("--$$ delaying FISH until %ld (last fish %ld, delay %ld, now %ld)",
- last_fish_arrived_at+RtsFlags.ParFlags.fishDelay,
- last_fish_arrived_at,
- RtsFlags.ParFlags.fishDelay, now);
- });
-
+ debugBelch("-- now=%ld\n", now));
+ IF_PAR_DEBUG(fish, // verbose,
+ if (outstandingFishes < RtsFlags.ParFlags.maxFishes &&
+ (last_fish_arrived_at!=0 &&
+ last_fish_arrived_at+delay > now)) {
+ debugBelch("--$$ <%llu> delaying FISH until %llu (last fish %llu, delay %llu)\n",
+ now, last_fish_arrived_at+delay,
+ last_fish_arrived_at,
+ delay);
+ });
+
if (outstandingFishes < RtsFlags.ParFlags.maxFishes &&
- (last_fish_arrived_at==0 ||
- (last_fish_arrived_at+RtsFlags.ParFlags.fishDelay <= now))) {
- /* outstandingFishes is set in sendFish, processFish;
- avoid flooding system with fishes via delay */
- pe = choosePE();
- sendFish(pe, mytid, NEW_FISH_AGE, NEW_FISH_HISTORY,
- NEW_FISH_HUNGER);
-
- // Global statistics: count no. of fishes
- if (RtsFlags.ParFlags.ParStats.Global &&
- RtsFlags.GcFlags.giveStats > NO_GC_STATS) {
- globalParStats.tot_fish_mess++;
- }
- }
-
- receivedFinish = processMessages();
- goto next_thread;
+ advisory_thread_count < RtsFlags.ParFlags.maxThreads) { // send a FISH, but when?
+ if (last_fish_arrived_at==0 ||
+ (last_fish_arrived_at+delay <= now)) { // send FISH now!
+ /* outstandingFishes is set in sendFish, processFish;
+ avoid flooding system with fishes via delay */
+ next_fish_to_send_at = 0;
+ } else {
+ /* ToDo: this should be done in the main scheduling loop to avoid the
+ busy wait here; not so bad if fish delay is very small */
+ int iq = 0; // DEBUGGING -- HWL
+ next_fish_to_send_at = last_fish_arrived_at+delay; // remember when to send
+ /* send a fish when ready, but process messages that arrive in the meantime */
+ do {
+ if (PacketsWaiting()) {
+ iq++; // DEBUGGING
+ *receivedFinish = processMessages();
}
- } else if (PacketsWaiting()) { /* Look for incoming messages */
- receivedFinish = processMessages();
- }
+ now = msTime();
+ } while (!*receivedFinish || now<next_fish_to_send_at);
+ // JB: This means the fish could become obsolete, if we receive
+ // work. Better check for work again?
+ // last line: while (!receivedFinish || !haveWork || now<...)
+ // next line: if (receivedFinish || haveWork )
+
+ if (*receivedFinish) // no need to send a FISH if we are finishing anyway
+ return rtsFalse; // NB: this will leave scheduler loop
+ // immediately after return!
+
+ IF_PAR_DEBUG(fish, // verbose,
+ debugBelch("--$$ <%llu> sent delayed fish (%d processMessages); active/total threads=%d/%d\n",now,iq,run_queue_len(),advisory_thread_count));
- /* Now we are sure that we have some work available */
- ASSERT(run_queue_hd != END_TSO_QUEUE);
+ }
- /* Take a thread from the run queue, if we have work */
- t = POP_RUN_QUEUE(); // take_off_run_queue(END_TSO_QUEUE);
- IF_DEBUG(sanity,checkTSO(t));
+ // JB: IMHO, this should all be hidden inside sendFish(...)
+ /* pe = choosePE();
+ sendFish(pe, thisPE, NEW_FISH_AGE, NEW_FISH_HISTORY,
+ NEW_FISH_HUNGER);
+
+ // Global statistics: count no. of fishes
+ if (RtsFlags.ParFlags.ParStats.Global &&
+ RtsFlags.GcFlags.giveStats > NO_GC_STATS) {
+ globalParStats.tot_fish_mess++;
+ }
+ */
+
+ /* delayed fishes must have been sent by now! */
+ next_fish_to_send_at = 0;
+ }
+
+ *receivedFinish = processMessages();
+# endif /* SPARKS */
+
+ return rtsFalse;
+ /* NB: this function always returns rtsFalse, meaning the scheduler
+ loop continues with the next iteration;
+ rationale:
+ return code means success in finding work; we enter this function
+ if there is no local work, thus have to send a fish which takes
+ time until it arrives with work; in the meantime we should process
+ messages in the main loop;
+ */
+}
+#endif // PARALLEL_HASKELL
+
+/* ----------------------------------------------------------------------------
+ * PAR/GRAN: Report stats & debugging info(?)
+ * ------------------------------------------------------------------------- */
+
+#if defined(PAR) || defined(GRAN)
+static void
+scheduleGranParReport(void)
+{
+ ASSERT(run_queue_hd != END_TSO_QUEUE);
+
+ /* Take a thread from the run queue, if we have work */
+ POP_RUN_QUEUE(t); // take_off_run_queue(END_TSO_QUEUE);
+
+ /* If this TSO has got its outport closed in the meantime,
+ * it mustn't be run. Instead, we have to clean it up as if it was finished.
+ * It has to be marked as TH_DEAD for this purpose.
+ * If it is TH_TERM instead, it is supposed to have finished in the normal way.
+
+JB: TODO: investigate wether state change field could be nuked
+ entirely and replaced by the normal tso state (whatnext
+ field). All we want to do is to kill tsos from outside.
+ */
/* ToDo: write something to the log-file
if (RTSflags.ParFlags.granSimStats && !sameThread)
CurrentTSO = t;
*/
/* the spark pool for the current PE */
- pool = &(MainRegTable.rSparks); // generalise to cap = &MainRegTable
+ pool = &(cap.r.rSparks); // cap = (old) MainCap
IF_DEBUG(scheduler,
- belch("--=^ %d threads, %d sparks on [%#x]",
+ debugBelch("--=^ %d threads, %d sparks on [%#x]\n",
run_queue_len(), spark_queue_len(pool), CURRENT_PROC));
-# if 1
- if (0 && RtsFlags.ParFlags.ParStats.Full &&
- t && LastTSO && t->id != LastTSO->id &&
- LastTSO->why_blocked == NotBlocked &&
- LastTSO->what_next != ThreadComplete) {
- // if previously scheduled TSO not blocked we have to record the context switch
- DumpVeryRawGranEvent(TimeOfLastYield, CURRENT_PROC, CURRENT_PROC,
- GR_DESCHEDULE, LastTSO, (StgClosure *)NULL, 0, 0);
- }
+ IF_PAR_DEBUG(fish,
+ debugBelch("--=^ %d threads, %d sparks on [%#x]\n",
+ run_queue_len(), spark_queue_len(pool), CURRENT_PROC));
if (RtsFlags.ParFlags.ParStats.Full &&
- (emitSchedule /* forced emit */ ||
- (t && LastTSO && t->id != LastTSO->id))) {
+ (t->par.sparkname != (StgInt)0) && // only log spark generated threads
+ (emitSchedule || // forced emit
+ (t && LastTSO && t->id != LastTSO->id))) {
/*
we are running a different TSO, so write a schedule event to log file
NB: If we use fair scheduling we also have to write a deschedule
previous tso has blocked whenever we switch to another tso, so
we don't need it in GUM for now
*/
+ IF_PAR_DEBUG(fish, // schedule,
+ debugBelch("____ scheduling spark generated thread %d (%lx) (%lx) via a forced emit\n",t->id,t,t->par.sparkname));
+
DumpRawGranEvent(CURRENT_PROC, CURRENT_PROC,
GR_SCHEDULE, t, (StgClosure *)NULL, 0, 0);
emitSchedule = rtsFalse;
}
-
-# endif
-#else /* !GRAN && !PAR */
-
- /* grab a thread from the run queue */
- ASSERT(run_queue_hd != END_TSO_QUEUE);
- t = POP_RUN_QUEUE();
- // Sanity check the thread we're about to run. This can be
- // expensive if there is lots of thread switching going on...
- IF_DEBUG(sanity,checkTSO(t));
+}
#endif
-
- grabCapability(&cap);
- cap->r.rCurrentTSO = t;
-
- /* context switches are now initiated by the timer signal, unless
- * the user specified "context switch as often as possible", with
- * +RTS -C0
- */
- if (
-#ifdef PROFILING
- RtsFlags.ProfFlags.profileInterval == 0 ||
-#endif
- (RtsFlags.ConcFlags.ctxtSwitchTicks == 0
- && (run_queue_hd != END_TSO_QUEUE
- || blocked_queue_hd != END_TSO_QUEUE
- || sleeping_queue != END_TSO_QUEUE)))
- context_switch = 1;
- else
- context_switch = 0;
-
- RELEASE_LOCK(&sched_mutex);
- IF_DEBUG(scheduler, sched_belch("-->> Running TSO %ld (%p) %s ...",
- t->id, t, whatNext_strs[t->what_next]));
-
-#ifdef PROFILING
- startHeapProfTimer();
-#endif
-
- /* +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ */
- /* Run the current thread
- */
- switch (cap->r.rCurrentTSO->what_next) {
- case ThreadKilled:
- case ThreadComplete:
- /* Thread already finished, return to scheduler. */
- ret = ThreadFinished;
- break;
- case ThreadEnterGHC:
- ret = StgRun((StgFunPtr) stg_enterStackTop, &cap->r);
- break;
- case ThreadRunGHC:
- ret = StgRun((StgFunPtr) stg_returnToStackTop, &cap->r);
- break;
- case ThreadEnterInterp:
- ret = interpretBCO(cap);
- break;
- default:
- barf("schedule: invalid what_next field");
- }
- /* +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ */
-
- /* Costs for the scheduler are assigned to CCS_SYSTEM */
-#ifdef PROFILING
- stopHeapProfTimer();
- CCCS = CCS_SYSTEM;
-#endif
-
- ACQUIRE_LOCK(&sched_mutex);
+/* ----------------------------------------------------------------------------
+ * After running a thread...
+ * ------------------------------------------------------------------------- */
-#ifdef SMP
- IF_DEBUG(scheduler,fprintf(stderr,"scheduler (task %ld): ", osThreadId()););
-#elif !defined(GRAN) && !defined(PAR)
- IF_DEBUG(scheduler,fprintf(stderr,"scheduler: "););
-#endif
- t = cap->r.rCurrentTSO;
-
+static void
+schedulePostRunThread(void)
+{
#if defined(PAR)
/* HACK 675: if the last thread didn't yield, make sure to print a
SCHEDULE event to the log file when StgRunning the next thread, even
TimeOfLastYield = CURRENT_TIME;
#endif
- switch (ret) {
+ /* some statistics gathering in the parallel case */
+
+#if defined(GRAN) || defined(PAR) || defined(EDEN)
+ switch (ret) {
case HeapOverflow:
-#if defined(GRAN)
+# if defined(GRAN)
IF_DEBUG(gran, DumpGranEvent(GR_DESCHEDULE, t));
globalGranStats.tot_heapover++;
-#elif defined(PAR)
+# elif defined(PAR)
globalParStats.tot_heapover++;
-#endif
-
- // did the task ask for a large block?
- if (cap->r.rHpAlloc > BLOCK_SIZE_W) {
- // if so, get one and push it on the front of the nursery.
- bdescr *bd;
- nat blocks;
-
- blocks = (nat)BLOCK_ROUND_UP(cap->r.rHpAlloc * sizeof(W_)) / BLOCK_SIZE;
-
- IF_DEBUG(scheduler,belch("--<< thread %ld (%p; %s) stopped: requesting a large block (size %d)",
- t->id, t,
- whatNext_strs[t->what_next], blocks));
-
- // don't do this if it would push us over the
- // alloc_blocks_lim limit; we'll GC first.
- if (alloc_blocks + blocks < alloc_blocks_lim) {
-
- alloc_blocks += blocks;
- bd = allocGroup( blocks );
-
- // link the new group into the list
- bd->link = cap->r.rCurrentNursery;
- bd->u.back = cap->r.rCurrentNursery->u.back;
- if (cap->r.rCurrentNursery->u.back != NULL) {
- cap->r.rCurrentNursery->u.back->link = bd;
- } else {
- ASSERT(g0s0->blocks == cap->r.rCurrentNursery &&
- g0s0->blocks == cap->r.rNursery);
- cap->r.rNursery = g0s0->blocks = bd;
- }
- cap->r.rCurrentNursery->u.back = bd;
-
- // initialise it as a nursery block
- bd->step = g0s0;
- bd->gen_no = 0;
- bd->flags = 0;
- bd->free = bd->start;
-
- // don't forget to update the block count in g0s0.
- g0s0->n_blocks += blocks;
- ASSERT(countBlocks(g0s0->blocks) == g0s0->n_blocks);
-
- // now update the nursery to point to the new block
- cap->r.rCurrentNursery = bd;
-
- // we might be unlucky and have another thread get on the
- // run queue before us and steal the large block, but in that
- // case the thread will just end up requesting another large
- // block.
- PUSH_ON_RUN_QUEUE(t);
- break;
- }
- }
-
- /* make all the running tasks block on a condition variable,
- * maybe set context_switch and wait till they all pile in,
- * then have them wait on a GC condition variable.
- */
- IF_DEBUG(scheduler,belch("--<< thread %ld (%p; %s) stopped: HeapOverflow",
- t->id, t, whatNext_strs[t->what_next]));
- threadPaused(t);
-#if defined(GRAN)
- ASSERT(!is_on_queue(t,CurrentProc));
-#elif defined(PAR)
- /* Currently we emit a DESCHEDULE event before GC in GUM.
- ToDo: either add separate event to distinguish SYSTEM time from rest
- or just nuke this DESCHEDULE (and the following SCHEDULE) */
- if (0 && RtsFlags.ParFlags.ParStats.Full) {
- DumpRawGranEvent(CURRENT_PROC, CURRENT_PROC,
- GR_DESCHEDULE, t, (StgClosure *)NULL, 0, 0);
- emitSchedule = rtsTrue;
- }
-#endif
-
- ready_to_gc = rtsTrue;
- context_switch = 1; /* stop other threads ASAP */
- PUSH_ON_RUN_QUEUE(t);
- /* actual GC is done at the end of the while loop */
+# endif
break;
-
- case StackOverflow:
-#if defined(GRAN)
+
+ case StackOverflow:
+# if defined(GRAN)
IF_DEBUG(gran,
DumpGranEvent(GR_DESCHEDULE, t));
globalGranStats.tot_stackover++;
-#elif defined(PAR)
+# elif defined(PAR)
// IF_DEBUG(par,
// DumpGranEvent(GR_DESCHEDULE, t);
globalParStats.tot_stackover++;
-#endif
- IF_DEBUG(scheduler,belch("--<< thread %ld (%p; %s) stopped, StackOverflow",
- t->id, t, whatNext_strs[t->what_next]));
- /* just adjust the stack for this thread, then pop it back
- * on the run queue.
- */
- threadPaused(t);
- {
- StgMainThread *m;
- /* enlarge the stack */
- StgTSO *new_t = threadStackOverflow(t);
-
- /* This TSO has moved, so update any pointers to it from the
- * main thread stack. It better not be on any other queues...
- * (it shouldn't be).
- */
- for (m = main_threads; m != NULL; m = m->link) {
- if (m->tso == t) {
- m->tso = new_t;
- }
- }
- threadPaused(new_t);
- PUSH_ON_RUN_QUEUE(new_t);
- }
+# endif
break;
case ThreadYielding:
-#if defined(GRAN)
+# if defined(GRAN)
IF_DEBUG(gran,
DumpGranEvent(GR_DESCHEDULE, t));
globalGranStats.tot_yields++;
-#elif defined(PAR)
+# elif defined(PAR)
// IF_DEBUG(par,
// DumpGranEvent(GR_DESCHEDULE, t);
globalParStats.tot_yields++;
-#endif
- /* put the thread back on the run queue. Then, if we're ready to
- * GC, check whether this is the last task to stop. If so, wake
- * up the GC thread. getThread will block during a GC until the
- * GC is finished.
- */
- IF_DEBUG(scheduler,
- if (t->what_next == ThreadEnterInterp) {
- /* ToDo: or maybe a timer expired when we were in Hugs?
- * or maybe someone hit ctrl-C
- */
- belch("--<< thread %ld (%p; %s) stopped to switch to Hugs",
- t->id, t, whatNext_strs[t->what_next]);
- } else {
- belch("--<< thread %ld (%p; %s) stopped, yielding",
- t->id, t, whatNext_strs[t->what_next]);
- }
- );
-
- threadPaused(t);
-
- IF_DEBUG(sanity,
- //belch("&& Doing sanity check on yielding TSO %ld.", t->id);
- checkTSO(t));
- ASSERT(t->link == END_TSO_QUEUE);
-#if defined(GRAN)
- ASSERT(!is_on_queue(t,CurrentProc));
+# endif
+ break;
- IF_DEBUG(sanity,
- //belch("&& Doing sanity check on all ThreadQueues (and their TSOs).");
- checkThreadQsSanity(rtsTrue));
-#endif
-#if defined(PAR)
- if (RtsFlags.ParFlags.doFairScheduling) {
- /* this does round-robin scheduling; good for concurrency */
- APPEND_TO_RUN_QUEUE(t);
- } else {
- /* this does unfair scheduling; good for parallelism */
- PUSH_ON_RUN_QUEUE(t);
- }
-#else
- /* this does round-robin scheduling; good for concurrency */
- APPEND_TO_RUN_QUEUE(t);
-#endif
-#if defined(GRAN)
- /* add a ContinueThread event to actually process the thread */
- new_event(CurrentProc, CurrentProc, CurrentTime[CurrentProc],
- ContinueThread,
- t, (StgClosure*)NULL, (rtsSpark*)NULL);
- IF_GRAN_DEBUG(bq,
- belch("GRAN: eventq and runnableq after adding yielded thread to queue again:");
- G_EVENTQ(0);
- G_CURR_THREADQ(0));
-#endif /* GRAN */
- break;
-
case ThreadBlocked:
-#if defined(GRAN)
+# if defined(GRAN)
IF_DEBUG(scheduler,
- belch("--<< thread %ld (%p; %s) stopped, blocking on node %p [PE %d] with BQ: ",
- t->id, t, whatNext_strs[t->what_next], t->block_info.closure, (t->block_info.closure==(StgClosure*)NULL ? 99 : where_is(t->block_info.closure)));
- if (t->block_info.closure!=(StgClosure*)NULL) print_bq(t->block_info.closure));
+ debugBelch("--<< thread %ld (%p; %s) stopped, blocking on node %p [PE %d] with BQ: ",
+ t->id, t, whatNext_strs[t->what_next], t->block_info.closure,
+ (t->block_info.closure==(StgClosure*)NULL ? 99 : where_is(t->block_info.closure)));
+ if (t->block_info.closure!=(StgClosure*)NULL)
+ print_bq(t->block_info.closure);
+ debugBelch("\n"));
// ??? needed; should emit block before
IF_DEBUG(gran,
((procStatus[CurrentProc]==Fetching) &&
(t->block_info.closure!=(StgClosure*)NULL)));
if (run_queue_hds[CurrentProc] == END_TSO_QUEUE &&
- !(!RtsFlags.GranFlags.DoAsyncFetch &&
- procStatus[CurrentProc]==Fetching))
- procStatus[CurrentProc] = Idle;
- */
+ !(!RtsFlags.GranFlags.DoAsyncFetch &&
+ procStatus[CurrentProc]==Fetching))
+ procStatus[CurrentProc] = Idle;
+ */
+# elif defined(PAR)
+//++PAR++ blockThread() writes the event (change?)
+# endif
+ break;
+
+ case ThreadFinished:
+ break;
+
+ default:
+ barf("parGlobalStats: unknown return code");
+ break;
+ }
+#endif
+}
+
+/* -----------------------------------------------------------------------------
+ * Handle a thread that returned to the scheduler with ThreadHeepOverflow
+ * -------------------------------------------------------------------------- */
+
+static rtsBool
+scheduleHandleHeapOverflow( Capability *cap, StgTSO *t )
+{
+ // did the task ask for a large block?
+ if (cap->r.rHpAlloc > BLOCK_SIZE) {
+ // if so, get one and push it on the front of the nursery.
+ bdescr *bd;
+ lnat blocks;
+
+ blocks = (lnat)BLOCK_ROUND_UP(cap->r.rHpAlloc) / BLOCK_SIZE;
+
+ IF_DEBUG(scheduler,
+ debugBelch("--<< thread %ld (%s) stopped: requesting a large block (size %ld)\n",
+ (long)t->id, whatNext_strs[t->what_next], blocks));
+
+ // don't do this if the nursery is (nearly) full, we'll GC first.
+ if (cap->r.rCurrentNursery->link != NULL ||
+ cap->r.rNursery->n_blocks == 1) { // paranoia to prevent infinite loop
+ // if the nursery has only one block.
+
+ ACQUIRE_SM_LOCK
+ bd = allocGroup( blocks );
+ RELEASE_SM_LOCK
+ cap->r.rNursery->n_blocks += blocks;
+
+ // link the new group into the list
+ bd->link = cap->r.rCurrentNursery;
+ bd->u.back = cap->r.rCurrentNursery->u.back;
+ if (cap->r.rCurrentNursery->u.back != NULL) {
+ cap->r.rCurrentNursery->u.back->link = bd;
+ } else {
+#if !defined(THREADED_RTS)
+ ASSERT(g0s0->blocks == cap->r.rCurrentNursery &&
+ g0s0 == cap->r.rNursery);
+#endif
+ cap->r.rNursery->blocks = bd;
+ }
+ cap->r.rCurrentNursery->u.back = bd;
+
+ // initialise it as a nursery block. We initialise the
+ // step, gen_no, and flags field of *every* sub-block in
+ // this large block, because this is easier than making
+ // sure that we always find the block head of a large
+ // block whenever we call Bdescr() (eg. evacuate() and
+ // isAlive() in the GC would both have to do this, at
+ // least).
+ {
+ bdescr *x;
+ for (x = bd; x < bd + blocks; x++) {
+ x->step = cap->r.rNursery;
+ x->gen_no = 0;
+ x->flags = 0;
+ }
+ }
+
+ // This assert can be a killer if the app is doing lots
+ // of large block allocations.
+ IF_DEBUG(sanity, checkNurserySanity(cap->r.rNursery));
+
+ // now update the nursery to point to the new block
+ cap->r.rCurrentNursery = bd;
+
+ // we might be unlucky and have another thread get on the
+ // run queue before us and steal the large block, but in that
+ // case the thread will just end up requesting another large
+ // block.
+ pushOnRunQueue(cap,t);
+ return rtsFalse; /* not actually GC'ing */
+ }
+ }
+
+ IF_DEBUG(scheduler,
+ debugBelch("--<< thread %ld (%s) stopped: HeapOverflow\n",
+ (long)t->id, whatNext_strs[t->what_next]));
+#if defined(GRAN)
+ ASSERT(!is_on_queue(t,CurrentProc));
+#elif defined(PARALLEL_HASKELL)
+ /* Currently we emit a DESCHEDULE event before GC in GUM.
+ ToDo: either add separate event to distinguish SYSTEM time from rest
+ or just nuke this DESCHEDULE (and the following SCHEDULE) */
+ if (0 && RtsFlags.ParFlags.ParStats.Full) {
+ DumpRawGranEvent(CURRENT_PROC, CURRENT_PROC,
+ GR_DESCHEDULE, t, (StgClosure *)NULL, 0, 0);
+ emitSchedule = rtsTrue;
+ }
+#endif
+
+ pushOnRunQueue(cap,t);
+ return rtsTrue;
+ /* actual GC is done at the end of the while loop in schedule() */
+}
+
+/* -----------------------------------------------------------------------------
+ * Handle a thread that returned to the scheduler with ThreadStackOverflow
+ * -------------------------------------------------------------------------- */
+
+static void
+scheduleHandleStackOverflow (Capability *cap, Task *task, StgTSO *t)
+{
+ IF_DEBUG(scheduler,debugBelch("--<< thread %ld (%s) stopped, StackOverflow\n",
+ (long)t->id, whatNext_strs[t->what_next]));
+ /* just adjust the stack for this thread, then pop it back
+ * on the run queue.
+ */
+ {
+ /* enlarge the stack */
+ StgTSO *new_t = threadStackOverflow(cap, t);
+
+ /* The TSO attached to this Task may have moved, so update the
+ * pointer to it.
+ */
+ if (task->tso == t) {
+ task->tso = new_t;
+ }
+ pushOnRunQueue(cap,new_t);
+ }
+}
+
+/* -----------------------------------------------------------------------------
+ * Handle a thread that returned to the scheduler with ThreadYielding
+ * -------------------------------------------------------------------------- */
+
+static rtsBool
+scheduleHandleYield( Capability *cap, StgTSO *t, nat prev_what_next )
+{
+ // Reset the context switch flag. We don't do this just before
+ // running the thread, because that would mean we would lose ticks
+ // during GC, which can lead to unfair scheduling (a thread hogs
+ // the CPU because the tick always arrives during GC). This way
+ // penalises threads that do a lot of allocation, but that seems
+ // better than the alternative.
+ context_switch = 0;
+
+ /* put the thread back on the run queue. Then, if we're ready to
+ * GC, check whether this is the last task to stop. If so, wake
+ * up the GC thread. getThread will block during a GC until the
+ * GC is finished.
+ */
+ IF_DEBUG(scheduler,
+ if (t->what_next != prev_what_next) {
+ debugBelch("--<< thread %ld (%s) stopped to switch evaluators\n",
+ (long)t->id, whatNext_strs[t->what_next]);
+ } else {
+ debugBelch("--<< thread %ld (%s) stopped, yielding\n",
+ (long)t->id, whatNext_strs[t->what_next]);
+ }
+ );
+
+ IF_DEBUG(sanity,
+ //debugBelch("&& Doing sanity check on yielding TSO %ld.", t->id);
+ checkTSO(t));
+ ASSERT(t->link == END_TSO_QUEUE);
+
+ // Shortcut if we're just switching evaluators: don't bother
+ // doing stack squeezing (which can be expensive), just run the
+ // thread.
+ if (t->what_next != prev_what_next) {
+ return rtsTrue;
+ }
+
+#if defined(GRAN)
+ ASSERT(!is_on_queue(t,CurrentProc));
+
+ IF_DEBUG(sanity,
+ //debugBelch("&& Doing sanity check on all ThreadQueues (and their TSOs).");
+ checkThreadQsSanity(rtsTrue));
+
+#endif
+
+ addToRunQueue(cap,t);
+
+#if defined(GRAN)
+ /* add a ContinueThread event to actually process the thread */
+ new_event(CurrentProc, CurrentProc, CurrentTime[CurrentProc],
+ ContinueThread,
+ t, (StgClosure*)NULL, (rtsSpark*)NULL);
+ IF_GRAN_DEBUG(bq,
+ debugBelch("GRAN: eventq and runnableq after adding yielded thread to queue again:\n");
+ G_EVENTQ(0);
+ G_CURR_THREADQ(0));
+#endif
+ return rtsFalse;
+}
+
+/* -----------------------------------------------------------------------------
+ * Handle a thread that returned to the scheduler with ThreadBlocked
+ * -------------------------------------------------------------------------- */
+
+static void
+scheduleHandleThreadBlocked( StgTSO *t
+#if !defined(GRAN) && !defined(DEBUG)
+ STG_UNUSED
+#endif
+ )
+{
+#if defined(GRAN)
+ IF_DEBUG(scheduler,
+ debugBelch("--<< thread %ld (%p; %s) stopped, blocking on node %p [PE %d] with BQ: \n",
+ t->id, t, whatNext_strs[t->what_next], t->block_info.closure, (t->block_info.closure==(StgClosure*)NULL ? 99 : where_is(t->block_info.closure)));
+ if (t->block_info.closure!=(StgClosure*)NULL) print_bq(t->block_info.closure));
+
+ // ??? needed; should emit block before
+ IF_DEBUG(gran,
+ DumpGranEvent(GR_DESCHEDULE, t));
+ prune_eventq(t, (StgClosure *)NULL); // prune ContinueThreads for t
+ /*
+ ngoq Dogh!
+ ASSERT(procStatus[CurrentProc]==Busy ||
+ ((procStatus[CurrentProc]==Fetching) &&
+ (t->block_info.closure!=(StgClosure*)NULL)));
+ if (run_queue_hds[CurrentProc] == END_TSO_QUEUE &&
+ !(!RtsFlags.GranFlags.DoAsyncFetch &&
+ procStatus[CurrentProc]==Fetching))
+ procStatus[CurrentProc] = Idle;
+ */
#elif defined(PAR)
- IF_DEBUG(scheduler,
- belch("--<< thread %ld (%p; %s) stopped, blocking on node %p with BQ: ",
- t->id, t, whatNext_strs[t->what_next], t->block_info.closure));
- IF_PAR_DEBUG(bq,
+ IF_DEBUG(scheduler,
+ debugBelch("--<< thread %ld (%p; %s) stopped, blocking on node %p with BQ: \n",
+ t->id, t, whatNext_strs[t->what_next], t->block_info.closure));
+ IF_PAR_DEBUG(bq,
+
+ if (t->block_info.closure!=(StgClosure*)NULL)
+ print_bq(t->block_info.closure));
+
+ /* Send a fetch (if BlockedOnGA) and dump event to log file */
+ blockThread(t);
+
+ /* whatever we schedule next, we must log that schedule */
+ emitSchedule = rtsTrue;
+
+#else /* !GRAN */
- if (t->block_info.closure!=(StgClosure*)NULL)
- print_bq(t->block_info.closure));
+ // We don't need to do anything. The thread is blocked, and it
+ // has tidied up its stack and placed itself on whatever queue
+ // it needs to be on.
- /* Send a fetch (if BlockedOnGA) and dump event to log file */
- blockThread(t);
+#if !defined(THREADED_RTS)
+ ASSERT(t->why_blocked != NotBlocked);
+ // This might not be true under THREADED_RTS: we don't have
+ // exclusive access to this TSO, so someone might have
+ // woken it up by now. This actually happens: try
+ // conc023 +RTS -N2.
+#endif
- /* whatever we schedule next, we must log that schedule */
- emitSchedule = rtsTrue;
+ IF_DEBUG(scheduler,
+ debugBelch("--<< thread %d (%s) stopped: ",
+ t->id, whatNext_strs[t->what_next]);
+ printThreadBlockage(t);
+ debugBelch("\n"));
+
+ /* Only for dumping event to log file
+ ToDo: do I need this in GranSim, too?
+ blockThread(t);
+ */
+#endif
+}
-#else /* !GRAN */
- /* don't need to do anything. Either the thread is blocked on
- * I/O, in which case we'll have called addToBlockedQueue
- * previously, or it's blocked on an MVar or Blackhole, in which
- * case it'll be on the relevant queue already.
- */
- IF_DEBUG(scheduler,
- fprintf(stderr, "--<< thread %d (%p) stopped: ", t->id, t);
- printThreadBlockage(t);
- fprintf(stderr, "\n"));
+/* -----------------------------------------------------------------------------
+ * Handle a thread that returned to the scheduler with ThreadFinished
+ * -------------------------------------------------------------------------- */
+
+static rtsBool
+scheduleHandleThreadFinished (Capability *cap STG_UNUSED, Task *task, StgTSO *t)
+{
+ /* Need to check whether this was a main thread, and if so,
+ * return with the return value.
+ *
+ * We also end up here if the thread kills itself with an
+ * uncaught exception, see Exception.cmm.
+ */
+ IF_DEBUG(scheduler,debugBelch("--++ thread %d (%s) finished\n",
+ t->id, whatNext_strs[t->what_next]));
- /* Only for dumping event to log file
- ToDo: do I need this in GranSim, too?
- blockThread(t);
- */
-#endif
- threadPaused(t);
- break;
-
- case ThreadFinished:
- /* Need to check whether this was a main thread, and if so, signal
- * the task that started it with the return value. If we have no
- * more main threads, we probably need to stop all the tasks until
- * we get a new one.
- */
- /* We also end up here if the thread kills itself with an
- * uncaught exception, see Exception.hc.
- */
- IF_DEBUG(scheduler,belch("--++ thread %d (%p) finished", t->id, t));
#if defined(GRAN)
endThread(t, CurrentProc); // clean-up the thread
-#elif defined(PAR)
+#elif defined(PARALLEL_HASKELL)
/* For now all are advisory -- HWL */
//if(t->priority==AdvisoryPriority) ??
- advisory_thread_count--;
+ advisory_thread_count--; // JB: Caution with this counter, buggy!
-# ifdef DIST
+# if defined(DIST)
if(t->dist.priority==RevalPriority)
FinishReval(t);
# endif
-
+
+# if defined(EDENOLD)
+ // the thread could still have an outport... (BUG)
+ if (t->eden.outport != -1) {
+ // delete the outport for the tso which has finished...
+ IF_PAR_DEBUG(eden_ports,
+ debugBelch("WARNING: Scheduler removes outport %d for TSO %d.\n",
+ t->eden.outport, t->id));
+ deleteOPT(t);
+ }
+ // thread still in the process (HEAVY BUG! since outport has just been closed...)
+ if (t->eden.epid != -1) {
+ IF_PAR_DEBUG(eden_ports,
+ debugBelch("WARNING: Scheduler removes TSO %d from process %d .\n",
+ t->id, t->eden.epid));
+ removeTSOfromProcess(t);
+ }
+# endif
+
+# if defined(PAR)
if (RtsFlags.ParFlags.ParStats.Full &&
!RtsFlags.ParFlags.ParStats.Suppressed)
DumpEndEvent(CURRENT_PROC, t, rtsFalse /* not mandatory */);
+
+ // t->par only contains statistics: left out for now...
+ IF_PAR_DEBUG(fish,
+ debugBelch("**** end thread: ended sparked thread %d (%lx); sparkname: %lx\n",
+ t->id,t,t->par.sparkname));
+# endif
+#endif // PARALLEL_HASKELL
+
+ //
+ // Check whether the thread that just completed was a bound
+ // thread, and if so return with the result.
+ //
+ // There is an assumption here that all thread completion goes
+ // through this point; we need to make sure that if a thread
+ // ends up in the ThreadKilled state, that it stays on the run
+ // queue so it can be dealt with here.
+ //
+
+ if (t->bound) {
+
+ if (t->bound != task) {
+#if !defined(THREADED_RTS)
+ // Must be a bound thread that is not the topmost one. Leave
+ // it on the run queue until the stack has unwound to the
+ // point where we can deal with this. Leaving it on the run
+ // queue also ensures that the garbage collector knows about
+ // this thread and its return value (it gets dropped from the
+ // all_threads list so there's no other way to find it).
+ appendToRunQueue(cap,t);
+ return rtsFalse;
+#else
+ // this cannot happen in the threaded RTS, because a
+ // bound thread can only be run by the appropriate Task.
+ barf("finished bound thread that isn't mine");
#endif
- break;
-
- default:
- barf("schedule: invalid thread return code %d", (int)ret);
- }
-
-#if defined(RTS_SUPPORTS_THREADS)
- /* I don't understand what this re-grab is doing -- sof */
- grabCapability(&cap);
+ }
+
+ ASSERT(task->tso == t);
+
+ if (t->what_next == ThreadComplete) {
+ if (task->ret) {
+ // NOTE: return val is tso->sp[1] (see StgStartup.hc)
+ *(task->ret) = (StgClosure *)task->tso->sp[1];
+ }
+ task->stat = Success;
+ } else {
+ if (task->ret) {
+ *(task->ret) = NULL;
+ }
+ if (sched_state >= SCHED_INTERRUPTING) {
+ task->stat = Interrupted;
+ } else {
+ task->stat = Killed;
+ }
+ }
+#ifdef DEBUG
+ removeThreadLabel((StgWord)task->tso->id);
#endif
+ return rtsTrue; // tells schedule() to return
+ }
-#ifdef PROFILING
- if (RtsFlags.ProfFlags.profileInterval==0 || performHeapProfile) {
+ return rtsFalse;
+}
+
+/* -----------------------------------------------------------------------------
+ * Perform a heap census, if PROFILING
+ * -------------------------------------------------------------------------- */
+
+static rtsBool
+scheduleDoHeapProfile( rtsBool ready_to_gc STG_UNUSED )
+{
+#if defined(PROFILING)
+ // When we have +RTS -i0 and we're heap profiling, do a census at
+ // every GC. This lets us get repeatable runs for debugging.
+ if (performHeapProfile ||
+ (RtsFlags.ProfFlags.profileInterval==0 &&
+ RtsFlags.ProfFlags.doHeapProfile && ready_to_gc)) {
+
+ // checking black holes is necessary before GC, otherwise
+ // there may be threads that are unreachable except by the
+ // blackhole queue, which the GC will consider to be
+ // deadlocked.
+ scheduleCheckBlackHoles(&MainCapability);
+
+ IF_DEBUG(scheduler, sched_belch("garbage collecting before heap census"));
GarbageCollect(GetRoots, rtsTrue);
+
+ IF_DEBUG(scheduler, sched_belch("performing heap census"));
heapCensus();
+
performHeapProfile = rtsFalse;
- ready_to_gc = rtsFalse; // we already GC'd
+ return rtsTrue; // true <=> we already GC'd
}
#endif
+ return rtsFalse;
+}
+
+/* -----------------------------------------------------------------------------
+ * Perform a garbage collection if necessary
+ * -------------------------------------------------------------------------- */
- if (ready_to_gc
-#ifdef SMP
- && allFreeCapabilities()
+static Capability *
+scheduleDoGC (Capability *cap, Task *task USED_IF_THREADS,
+ rtsBool force_major, void (*get_roots)(evac_fn))
+{
+ StgTSO *t;
+#ifdef THREADED_RTS
+ static volatile StgWord waiting_for_gc;
+ rtsBool was_waiting;
+ nat i;
#endif
- ) {
- /* everybody back, start the GC.
- * Could do it in this thread, or signal a condition var
- * to do it in another thread. Either way, we need to
- * broadcast on gc_pending_cond afterward.
- */
-#if defined(RTS_SUPPORTS_THREADS)
- IF_DEBUG(scheduler,sched_belch("doing GC"));
+
+#ifdef THREADED_RTS
+ // In order to GC, there must be no threads running Haskell code.
+ // Therefore, the GC thread needs to hold *all* the capabilities,
+ // and release them after the GC has completed.
+ //
+ // This seems to be the simplest way: previous attempts involved
+ // making all the threads with capabilities give up their
+ // capabilities and sleep except for the *last* one, which
+ // actually did the GC. But it's quite hard to arrange for all
+ // the other tasks to sleep and stay asleep.
+ //
+
+ was_waiting = cas(&waiting_for_gc, 0, 1);
+ if (was_waiting) {
+ do {
+ IF_DEBUG(scheduler, sched_belch("someone else is trying to GC..."));
+ if (cap) yieldCapability(&cap,task);
+ } while (waiting_for_gc);
+ return cap; // NOTE: task->cap might have changed here
+ }
+
+ for (i=0; i < n_capabilities; i++) {
+ IF_DEBUG(scheduler, sched_belch("ready_to_gc, grabbing all the capabilies (%d/%d)", i, n_capabilities));
+ if (cap != &capabilities[i]) {
+ Capability *pcap = &capabilities[i];
+ // we better hope this task doesn't get migrated to
+ // another Capability while we're waiting for this one.
+ // It won't, because load balancing happens while we have
+ // all the Capabilities, but even so it's a slightly
+ // unsavoury invariant.
+ task->cap = pcap;
+ context_switch = 1;
+ waitForReturnCapability(&pcap, task);
+ if (pcap != &capabilities[i]) {
+ barf("scheduleDoGC: got the wrong capability");
+ }
+ }
+ }
+
+ waiting_for_gc = rtsFalse;
#endif
- GarbageCollect(GetRoots,rtsFalse);
- ready_to_gc = rtsFalse;
-#ifdef SMP
- broadcastCondition(&gc_pending_cond);
+
+ /* Kick any transactions which are invalid back to their
+ * atomically frames. When next scheduled they will try to
+ * commit, this commit will fail and they will retry.
+ */
+ {
+ StgTSO *next;
+
+ for (t = all_threads; t != END_TSO_QUEUE; t = next) {
+ if (t->what_next == ThreadRelocated) {
+ next = t->link;
+ } else {
+ next = t->global_link;
+ if (t -> trec != NO_TREC && t -> why_blocked == NotBlocked) {
+ if (!stmValidateNestOfTransactions (t -> trec)) {
+ IF_DEBUG(stm, sched_belch("trec %p found wasting its time", t));
+
+ // strip the stack back to the
+ // ATOMICALLY_FRAME, aborting the (nested)
+ // transaction, and saving the stack of any
+ // partially-evaluated thunks on the heap.
+ raiseAsync_(&capabilities[0], t, NULL, rtsTrue, NULL);
+
+#ifdef REG_R1
+ ASSERT(get_itbl((StgClosure *)t->sp)->type == ATOMICALLY_FRAME);
#endif
-#if defined(GRAN)
- /* add a ContinueThread event to continue execution of current thread */
- new_event(CurrentProc, CurrentProc, CurrentTime[CurrentProc],
- ContinueThread,
- t, (StgClosure*)NULL, (rtsSpark*)NULL);
- IF_GRAN_DEBUG(bq,
- fprintf(stderr, "GRAN: eventq and runnableq after Garbage collection:\n");
- G_EVENTQ(0);
- G_CURR_THREADQ(0));
-#endif /* GRAN */
+ }
+ }
+ }
+ }
}
+
+ // so this happens periodically:
+ if (cap) scheduleCheckBlackHoles(cap);
+
+ IF_DEBUG(scheduler, printAllThreads());
-#if defined(GRAN)
- next_thread:
- IF_GRAN_DEBUG(unused,
- print_eventq(EventHd));
+ /*
+ * We now have all the capabilities; if we're in an interrupting
+ * state, then we should take the opportunity to delete all the
+ * threads in the system.
+ */
+ if (sched_state >= SCHED_INTERRUPTING) {
+ deleteAllThreads(&capabilities[0]);
+ sched_state = SCHED_INTERRUPTED;
+ }
- event = get_next_event();
-#elif defined(PAR)
- next_thread:
- /* ToDo: wait for next message to arrive rather than busy wait */
+ /* everybody back, start the GC.
+ * Could do it in this thread, or signal a condition var
+ * to do it in another thread. Either way, we need to
+ * broadcast on gc_pending_cond afterward.
+ */
+#if defined(THREADED_RTS)
+ IF_DEBUG(scheduler,sched_belch("doing GC"));
+#endif
+ GarbageCollect(get_roots, force_major);
+
+#if defined(THREADED_RTS)
+ // release our stash of capabilities.
+ for (i = 0; i < n_capabilities; i++) {
+ if (cap != &capabilities[i]) {
+ task->cap = &capabilities[i];
+ releaseCapability(&capabilities[i]);
+ }
+ }
+ if (cap) {
+ task->cap = cap;
+ } else {
+ task->cap = NULL;
+ }
+#endif
+
+#if defined(GRAN)
+ /* add a ContinueThread event to continue execution of current thread */
+ new_event(CurrentProc, CurrentProc, CurrentTime[CurrentProc],
+ ContinueThread,
+ t, (StgClosure*)NULL, (rtsSpark*)NULL);
+ IF_GRAN_DEBUG(bq,
+ debugBelch("GRAN: eventq and runnableq after Garbage collection:\n\n");
+ G_EVENTQ(0);
+ G_CURR_THREADQ(0));
#endif /* GRAN */
- } /* end of while(1) */
+ return cap;
+}
- IF_PAR_DEBUG(verbose,
- belch("== Leaving schedule() after having received Finish"));
+/* ---------------------------------------------------------------------------
+ * rtsSupportsBoundThreads(): is the RTS built to support bound threads?
+ * used by Control.Concurrent for error checking.
+ * ------------------------------------------------------------------------- */
+
+StgBool
+rtsSupportsBoundThreads(void)
+{
+#if defined(THREADED_RTS)
+ return rtsTrue;
+#else
+ return rtsFalse;
+#endif
}
/* ---------------------------------------------------------------------------
- * deleteAllThreads(): kill all the live threads.
- *
- * This is used when we catch a user interrupt (^C), before performing
- * any necessary cleanups and running finalizers.
+ * isThreadBound(tso): check whether tso is bound to an OS thread.
+ * ------------------------------------------------------------------------- */
+
+StgBool
+isThreadBound(StgTSO* tso USED_IF_THREADS)
+{
+#if defined(THREADED_RTS)
+ return (tso->bound != NULL);
+#endif
+ return rtsFalse;
+}
+
+/* ---------------------------------------------------------------------------
+ * Singleton fork(). Do not copy any running threads.
+ * ------------------------------------------------------------------------- */
+
+#if !defined(mingw32_HOST_OS)
+#define FORKPROCESS_PRIMOP_SUPPORTED
+#endif
+
+#ifdef FORKPROCESS_PRIMOP_SUPPORTED
+static void
+deleteThread_(Capability *cap, StgTSO *tso);
+#endif
+StgInt
+forkProcess(HsStablePtr *entry
+#ifndef FORKPROCESS_PRIMOP_SUPPORTED
+ STG_UNUSED
+#endif
+ )
+{
+#ifdef FORKPROCESS_PRIMOP_SUPPORTED
+ Task *task;
+ pid_t pid;
+ StgTSO* t,*next;
+ Capability *cap;
+
+#if defined(THREADED_RTS)
+ if (RtsFlags.ParFlags.nNodes > 1) {
+ errorBelch("forking not supported with +RTS -N<n> greater than 1");
+ stg_exit(EXIT_FAILURE);
+ }
+#endif
+
+ IF_DEBUG(scheduler,sched_belch("forking!"));
+
+ // ToDo: for SMP, we should probably acquire *all* the capabilities
+ cap = rts_lock();
+
+ pid = fork();
+
+ if (pid) { // parent
+
+ // just return the pid
+ rts_unlock(cap);
+ return pid;
+
+ } else { // child
+
+ // Now, all OS threads except the thread that forked are
+ // stopped. We need to stop all Haskell threads, including
+ // those involved in foreign calls. Also we need to delete
+ // all Tasks, because they correspond to OS threads that are
+ // now gone.
+
+ for (t = all_threads; t != END_TSO_QUEUE; t = next) {
+ next = t->global_link;
+ // don't allow threads to catch the ThreadKilled
+ // exception, but we do want to raiseAsync() because these
+ // threads may be evaluating thunks that we need later.
+ deleteThread_(cap,t);
+ }
+
+ // Empty the run queue. It seems tempting to let all the
+ // killed threads stay on the run queue as zombies to be
+ // cleaned up later, but some of them correspond to bound
+ // threads for which the corresponding Task does not exist.
+ cap->run_queue_hd = END_TSO_QUEUE;
+ cap->run_queue_tl = END_TSO_QUEUE;
+
+ // Any suspended C-calling Tasks are no more, their OS threads
+ // don't exist now:
+ cap->suspended_ccalling_tasks = NULL;
+
+ // Empty the all_threads list. Otherwise, the garbage
+ // collector may attempt to resurrect some of these threads.
+ all_threads = END_TSO_QUEUE;
+
+ // Wipe the task list, except the current Task.
+ ACQUIRE_LOCK(&sched_mutex);
+ for (task = all_tasks; task != NULL; task=task->all_link) {
+ if (task != cap->running_task) {
+ discardTask(task);
+ }
+ }
+ RELEASE_LOCK(&sched_mutex);
+
+#if defined(THREADED_RTS)
+ // Wipe our spare workers list, they no longer exist. New
+ // workers will be created if necessary.
+ cap->spare_workers = NULL;
+ cap->returning_tasks_hd = NULL;
+ cap->returning_tasks_tl = NULL;
+#endif
+
+ cap = rts_evalStableIO(cap, entry, NULL); // run the action
+ rts_checkSchedStatus("forkProcess",cap);
+
+ rts_unlock(cap);
+ hs_exit(); // clean up and exit
+ stg_exit(EXIT_SUCCESS);
+ }
+#else /* !FORKPROCESS_PRIMOP_SUPPORTED */
+ barf("forkProcess#: primop not supported on this platform, sorry!\n");
+ return -1;
+#endif
+}
+
+/* ---------------------------------------------------------------------------
+ * Delete all the threads in the system
* ------------------------------------------------------------------------- */
-void deleteAllThreads ( void )
+static void
+deleteAllThreads ( Capability *cap )
{
StgTSO* t, *next;
IF_DEBUG(scheduler,sched_belch("deleting all threads"));
for (t = all_threads; t != END_TSO_QUEUE; t = next) {
- next = t->global_link;
- deleteThread(t);
+ if (t->what_next == ThreadRelocated) {
+ next = t->link;
+ } else {
+ next = t->global_link;
+ deleteThread(cap,t);
+ }
}
- run_queue_hd = run_queue_tl = END_TSO_QUEUE;
- blocked_queue_hd = blocked_queue_tl = END_TSO_QUEUE;
- sleeping_queue = END_TSO_QUEUE;
+
+ // The run queue now contains a bunch of ThreadKilled threads. We
+ // must not throw these away: the main thread(s) will be in there
+ // somewhere, and the main scheduler loop has to deal with it.
+ // Also, the run queue is the only thing keeping these threads from
+ // being GC'd, and we don't want the "main thread has been GC'd" panic.
+
+#if !defined(THREADED_RTS)
+ ASSERT(blocked_queue_hd == END_TSO_QUEUE);
+ ASSERT(sleeping_queue == END_TSO_QUEUE);
+#endif
}
-/* startThread and insertThread are now in GranSim.c -- HWL */
+/* -----------------------------------------------------------------------------
+ Managing the suspended_ccalling_tasks list.
+ Locks required: sched_mutex
+ -------------------------------------------------------------------------- */
+STATIC_INLINE void
+suspendTask (Capability *cap, Task *task)
+{
+ ASSERT(task->next == NULL && task->prev == NULL);
+ task->next = cap->suspended_ccalling_tasks;
+ task->prev = NULL;
+ if (cap->suspended_ccalling_tasks) {
+ cap->suspended_ccalling_tasks->prev = task;
+ }
+ cap->suspended_ccalling_tasks = task;
+}
-//@node Suspend and Resume, Run queue code, Main scheduling loop, Main scheduling code
-//@subsection Suspend and Resume
+STATIC_INLINE void
+recoverSuspendedTask (Capability *cap, Task *task)
+{
+ if (task->prev) {
+ task->prev->next = task->next;
+ } else {
+ ASSERT(cap->suspended_ccalling_tasks == task);
+ cap->suspended_ccalling_tasks = task->next;
+ }
+ if (task->next) {
+ task->next->prev = task->prev;
+ }
+ task->next = task->prev = NULL;
+}
/* ---------------------------------------------------------------------------
* Suspending & resuming Haskell threads.
* on return from the C function.
* ------------------------------------------------------------------------- */
-StgInt
-suspendThread( StgRegTable *reg,
- rtsBool concCall
-#if !defined(RTS_SUPPORTS_THREADS)
- STG_UNUSED
-#endif
- )
+void *
+suspendThread (StgRegTable *reg)
{
- nat tok;
Capability *cap;
+ int saved_errno = errno;
+ StgTSO *tso;
+ Task *task;
- /* assume that *reg is a pointer to the StgRegTable part
- * of a Capability.
+ /* assume that *reg is a pointer to the StgRegTable part of a Capability.
*/
- cap = (Capability *)((void *)reg - sizeof(StgFunTable));
+ cap = regTableToCapability(reg);
- ACQUIRE_LOCK(&sched_mutex);
+ task = cap->running_task;
+ tso = cap->r.rCurrentTSO;
IF_DEBUG(scheduler,
- sched_belch("thread %d did a _ccall_gc", cap->r.rCurrentTSO->id));
+ sched_belch("thread %d did a safe foreign call", cap->r.rCurrentTSO->id));
- threadPaused(cap->r.rCurrentTSO);
- cap->r.rCurrentTSO->link = suspended_ccalling_threads;
- suspended_ccalling_threads = cap->r.rCurrentTSO;
+ // XXX this might not be necessary --SDM
+ tso->what_next = ThreadRunGHC;
-#if defined(RTS_SUPPORTS_THREADS)
- cap->r.rCurrentTSO->why_blocked = BlockedOnCCall;
-#endif
+ threadPaused(cap,tso);
- /* Use the thread ID as the token; it should be unique */
- tok = cap->r.rCurrentTSO->id;
+ if(tso->blocked_exceptions == NULL) {
+ tso->why_blocked = BlockedOnCCall;
+ tso->blocked_exceptions = END_TSO_QUEUE;
+ } else {
+ tso->why_blocked = BlockedOnCCall_NoUnblockExc;
+ }
+
+ // Hand back capability
+ task->suspended_tso = tso;
+
+ ACQUIRE_LOCK(&cap->lock);
- /* Hand back capability */
- releaseCapability(cap);
+ suspendTask(cap,task);
+ cap->in_haskell = rtsFalse;
+ releaseCapability_(cap);
-#if defined(RTS_SUPPORTS_THREADS)
+ RELEASE_LOCK(&cap->lock);
+
+#if defined(THREADED_RTS)
/* Preparing to leave the RTS, so ensure there's a native thread/task
waiting to take over.
-
- ToDo: optimise this and only create a new task if there's a need
- for one (i.e., if there's only one Concurrent Haskell thread alive,
- there's no need to create a new task).
*/
- IF_DEBUG(scheduler, sched_belch("worker thread (%d): leaving RTS", tok));
- if (concCall) {
- startTask(taskStart);
- }
+ IF_DEBUG(scheduler, sched_belch("thread %d: leaving RTS", tso->id));
#endif
- /* Other threads _might_ be available for execution; signal this */
- THREAD_RUNNABLE();
- RELEASE_LOCK(&sched_mutex);
- return tok;
+ errno = saved_errno;
+ return task;
}
StgRegTable *
-resumeThread( StgInt tok,
- rtsBool concCall
-#if !defined(RTS_SUPPORTS_THREADS)
- STG_UNUSED
-#endif
- )
+resumeThread (void *task_)
{
- StgTSO *tso, **prev;
- Capability *cap;
-
-#if defined(RTS_SUPPORTS_THREADS)
- /* Wait for permission to re-enter the RTS with the result. */
- if ( concCall ) {
- grabReturnCapability(&sched_mutex, &cap);
- } else {
- grabCapability(&cap);
- }
-#else
- grabCapability(&cap);
-#endif
-
- /* Remove the thread off of the suspended list */
- prev = &suspended_ccalling_threads;
- for (tso = suspended_ccalling_threads;
- tso != END_TSO_QUEUE;
- prev = &tso->link, tso = tso->link) {
- if (tso->id == (StgThreadID)tok) {
- *prev = tso->link;
- break;
+ StgTSO *tso;
+ Capability *cap;
+ int saved_errno = errno;
+ Task *task = task_;
+
+ cap = task->cap;
+ // Wait for permission to re-enter the RTS with the result.
+ waitForReturnCapability(&cap,task);
+ // we might be on a different capability now... but if so, our
+ // entry on the suspended_ccalling_tasks list will also have been
+ // migrated.
+
+ // Remove the thread from the suspended list
+ recoverSuspendedTask(cap,task);
+
+ tso = task->suspended_tso;
+ task->suspended_tso = NULL;
+ tso->link = END_TSO_QUEUE;
+ IF_DEBUG(scheduler, sched_belch("thread %d: re-entering RTS", tso->id));
+
+ if (tso->why_blocked == BlockedOnCCall) {
+ awakenBlockedQueue(cap,tso->blocked_exceptions);
+ tso->blocked_exceptions = NULL;
}
- }
- if (tso == END_TSO_QUEUE) {
- barf("resumeThread: thread not found");
- }
- tso->link = END_TSO_QUEUE;
- /* Reset blocking status */
- tso->why_blocked = NotBlocked;
-
- RELEASE_LOCK(&sched_mutex);
+
+ /* Reset blocking status */
+ tso->why_blocked = NotBlocked;
+
+ cap->r.rCurrentTSO = tso;
+ cap->in_haskell = rtsTrue;
+ errno = saved_errno;
- cap->r.rCurrentTSO = tso;
- return &cap->r;
-}
+ /* We might have GC'd, mark the TSO dirty again */
+ dirtyTSO(tso);
+ IF_DEBUG(sanity, checkTSO(tso));
-/* ---------------------------------------------------------------------------
- * Static functions
- * ------------------------------------------------------------------------ */
-static void unblockThread(StgTSO *tso);
+ return &cap->r;
+}
/* ---------------------------------------------------------------------------
* Comparing Thread ids.
* instances of Eq/Ord for ThreadIds.
* ------------------------------------------------------------------------ */
-int cmp_thread(const StgTSO *tso1, const StgTSO *tso2)
+int
+cmp_thread(StgPtr tso1, StgPtr tso2)
{
- StgThreadID id1 = tso1->id;
- StgThreadID id2 = tso2->id;
+ StgThreadID id1 = ((StgTSO *)tso1)->id;
+ StgThreadID id2 = ((StgTSO *)tso2)->id;
if (id1 < id2) return (-1);
if (id1 > id2) return 1;
*
* This is used in the implementation of Show for ThreadIds.
* ------------------------------------------------------------------------ */
-int rts_getThreadId(const StgTSO *tso)
+int
+rts_getThreadId(StgPtr tso)
+{
+ return ((StgTSO *)tso)->id;
+}
+
+#ifdef DEBUG
+void
+labelThread(StgPtr tso, char *label)
{
- return tso->id;
+ int len;
+ void *buf;
+
+ /* Caveat: Once set, you can only set the thread name to "" */
+ len = strlen(label)+1;
+ buf = stgMallocBytes(len * sizeof(char), "Schedule.c:labelThread()");
+ strncpy(buf,label,len);
+ /* Update will free the old memory for us */
+ updateThreadLabel(((StgTSO *)tso)->id,buf);
}
+#endif /* DEBUG */
/* ---------------------------------------------------------------------------
Create a new thread.
currently pri (priority) is only used in a GRAN setup -- HWL
------------------------------------------------------------------------ */
-//@cindex createThread
#if defined(GRAN)
/* currently pri (priority) is only used in a GRAN setup -- HWL */
StgTSO *
-createThread(nat stack_size, StgInt pri)
-{
- return createThread_(stack_size, rtsFalse, pri);
-}
-
-static StgTSO *
-createThread_(nat size, rtsBool have_lock, StgInt pri)
-{
+createThread(nat size, StgInt pri)
#else
StgTSO *
-createThread(nat stack_size)
-{
- return createThread_(stack_size, rtsFalse);
-}
-
-static StgTSO *
-createThread_(nat size, rtsBool have_lock)
-{
+createThread(Capability *cap, nat size)
#endif
-
+{
StgTSO *tso;
nat stack_size;
+ /* sched_mutex is *not* required */
+
/* First check whether we should create a thread at all */
-#if defined(PAR)
- /* check that no more than RtsFlags.ParFlags.maxThreads threads are created */
- if (advisory_thread_count >= RtsFlags.ParFlags.maxThreads) {
- threadsIgnored++;
- belch("{createThread}Daq ghuH: refusing to create another thread; no more than %d threads allowed (currently %d)",
- RtsFlags.ParFlags.maxThreads, advisory_thread_count);
- return END_TSO_QUEUE;
- }
- threadsCreated++;
+#if defined(PARALLEL_HASKELL)
+ /* check that no more than RtsFlags.ParFlags.maxThreads threads are created */
+ if (advisory_thread_count >= RtsFlags.ParFlags.maxThreads) {
+ threadsIgnored++;
+ debugBelch("{createThread}Daq ghuH: refusing to create another thread; no more than %d threads allowed (currently %d)\n",
+ RtsFlags.ParFlags.maxThreads, advisory_thread_count);
+ return END_TSO_QUEUE;
+ }
+ threadsCreated++;
#endif
#if defined(GRAN)
- ASSERT(!RtsFlags.GranFlags.Light || CurrentProc==0);
+ ASSERT(!RtsFlags.GranFlags.Light || CurrentProc==0);
#endif
- // ToDo: check whether size = stack_size - TSO_STRUCT_SIZEW
-
- /* catch ridiculously small stack sizes */
- if (size < MIN_STACK_WORDS + TSO_STRUCT_SIZEW) {
- size = MIN_STACK_WORDS + TSO_STRUCT_SIZEW;
- }
+ // ToDo: check whether size = stack_size - TSO_STRUCT_SIZEW
- stack_size = size - TSO_STRUCT_SIZEW;
+ /* catch ridiculously small stack sizes */
+ if (size < MIN_STACK_WORDS + TSO_STRUCT_SIZEW) {
+ size = MIN_STACK_WORDS + TSO_STRUCT_SIZEW;
+ }
- tso = (StgTSO *)allocate(size);
- TICK_ALLOC_TSO(stack_size, 0);
+ stack_size = size - TSO_STRUCT_SIZEW;
+
+ tso = (StgTSO *)allocateLocal(cap, size);
+ TICK_ALLOC_TSO(stack_size, 0);
- SET_HDR(tso, &stg_TSO_info, CCS_SYSTEM);
+ SET_HDR(tso, &stg_TSO_info, CCS_SYSTEM);
#if defined(GRAN)
- SET_GRAN_HDR(tso, ThisPE);
+ SET_GRAN_HDR(tso, ThisPE);
#endif
- tso->what_next = ThreadEnterGHC;
-
- /* tso->id needs to be unique. For now we use a heavyweight mutex to
- * protect the increment operation on next_thread_id.
- * In future, we could use an atomic increment instead.
- */
- if (!have_lock) { ACQUIRE_LOCK(&sched_mutex); }
- tso->id = next_thread_id++;
- if (!have_lock) { RELEASE_LOCK(&sched_mutex); }
- tso->why_blocked = NotBlocked;
- tso->blocked_exceptions = NULL;
+ // Always start with the compiled code evaluator
+ tso->what_next = ThreadRunGHC;
- tso->stack_size = stack_size;
- tso->max_stack_size = round_to_mblocks(RtsFlags.GcFlags.maxStkSize)
- - TSO_STRUCT_SIZEW;
- tso->sp = (P_)&(tso->stack) + stack_size;
+ tso->why_blocked = NotBlocked;
+ tso->blocked_exceptions = NULL;
+ tso->flags = TSO_DIRTY;
+
+ tso->saved_errno = 0;
+ tso->bound = NULL;
+
+ tso->stack_size = stack_size;
+ tso->max_stack_size = round_to_mblocks(RtsFlags.GcFlags.maxStkSize)
+ - TSO_STRUCT_SIZEW;
+ tso->sp = (P_)&(tso->stack) + stack_size;
+ tso->trec = NO_TREC;
+
#ifdef PROFILING
- tso->prof.CCCS = CCS_MAIN;
+ tso->prof.CCCS = CCS_MAIN;
#endif
-
+
/* put a stop frame on the stack */
- tso->sp -= sizeofW(StgStopFrame);
- SET_HDR((StgClosure*)tso->sp,(StgInfoTable *)&stg_stop_thread_info,CCS_SYSTEM);
- tso->su = (StgUpdateFrame*)tso->sp;
-
+ tso->sp -= sizeofW(StgStopFrame);
+ SET_HDR((StgClosure*)tso->sp,(StgInfoTable *)&stg_stop_thread_info,CCS_SYSTEM);
+ tso->link = END_TSO_QUEUE;
+
// ToDo: check this
#if defined(GRAN)
- tso->link = END_TSO_QUEUE;
- /* uses more flexible routine in GranSim */
- insertThread(tso, CurrentProc);
+ /* uses more flexible routine in GranSim */
+ insertThread(tso, CurrentProc);
#else
- /* In a non-GranSim setup the pushing of a TSO onto the runq is separated
- * from its creation
- */
+ /* In a non-GranSim setup the pushing of a TSO onto the runq is separated
+ * from its creation
+ */
#endif
-
+
#if defined(GRAN)
- if (RtsFlags.GranFlags.GranSimStats.Full)
- DumpGranEvent(GR_START,tso);
-#elif defined(PAR)
- if (RtsFlags.ParFlags.ParStats.Full)
- DumpGranEvent(GR_STARTQ,tso);
- /* HACk to avoid SCHEDULE
- LastTSO = tso; */
+ if (RtsFlags.GranFlags.GranSimStats.Full)
+ DumpGranEvent(GR_START,tso);
+#elif defined(PARALLEL_HASKELL)
+ if (RtsFlags.ParFlags.ParStats.Full)
+ DumpGranEvent(GR_STARTQ,tso);
+ /* HACk to avoid SCHEDULE
+ LastTSO = tso; */
#endif
-
- /* Link the new thread on the global thread list.
- */
- tso->global_link = all_threads;
- all_threads = tso;
-
+
+ /* Link the new thread on the global thread list.
+ */
+ ACQUIRE_LOCK(&sched_mutex);
+ tso->id = next_thread_id++; // while we have the mutex
+ tso->global_link = all_threads;
+ all_threads = tso;
+ RELEASE_LOCK(&sched_mutex);
+
#if defined(DIST)
- tso->dist.priority = MandatoryPriority; //by default that is...
+ tso->dist.priority = MandatoryPriority; //by default that is...
#endif
-
+
#if defined(GRAN)
- tso->gran.pri = pri;
+ tso->gran.pri = pri;
# if defined(DEBUG)
- tso->gran.magic = TSO_MAGIC; // debugging only
+ tso->gran.magic = TSO_MAGIC; // debugging only
# endif
- tso->gran.sparkname = 0;
- tso->gran.startedat = CURRENT_TIME;
- tso->gran.exported = 0;
- tso->gran.basicblocks = 0;
- tso->gran.allocs = 0;
- tso->gran.exectime = 0;
- tso->gran.fetchtime = 0;
- tso->gran.fetchcount = 0;
- tso->gran.blocktime = 0;
- tso->gran.blockcount = 0;
- tso->gran.blockedat = 0;
- tso->gran.globalsparks = 0;
- tso->gran.localsparks = 0;
- if (RtsFlags.GranFlags.Light)
- tso->gran.clock = Now; /* local clock */
- else
- tso->gran.clock = 0;
-
- IF_DEBUG(gran,printTSO(tso));
-#elif defined(PAR)
+ tso->gran.sparkname = 0;
+ tso->gran.startedat = CURRENT_TIME;
+ tso->gran.exported = 0;
+ tso->gran.basicblocks = 0;
+ tso->gran.allocs = 0;
+ tso->gran.exectime = 0;
+ tso->gran.fetchtime = 0;
+ tso->gran.fetchcount = 0;
+ tso->gran.blocktime = 0;
+ tso->gran.blockcount = 0;
+ tso->gran.blockedat = 0;
+ tso->gran.globalsparks = 0;
+ tso->gran.localsparks = 0;
+ if (RtsFlags.GranFlags.Light)
+ tso->gran.clock = Now; /* local clock */
+ else
+ tso->gran.clock = 0;
+
+ IF_DEBUG(gran,printTSO(tso));
+#elif defined(PARALLEL_HASKELL)
# if defined(DEBUG)
- tso->par.magic = TSO_MAGIC; // debugging only
+ tso->par.magic = TSO_MAGIC; // debugging only
# endif
- tso->par.sparkname = 0;
- tso->par.startedat = CURRENT_TIME;
- tso->par.exported = 0;
- tso->par.basicblocks = 0;
- tso->par.allocs = 0;
- tso->par.exectime = 0;
- tso->par.fetchtime = 0;
- tso->par.fetchcount = 0;
- tso->par.blocktime = 0;
- tso->par.blockcount = 0;
- tso->par.blockedat = 0;
- tso->par.globalsparks = 0;
- tso->par.localsparks = 0;
+ tso->par.sparkname = 0;
+ tso->par.startedat = CURRENT_TIME;
+ tso->par.exported = 0;
+ tso->par.basicblocks = 0;
+ tso->par.allocs = 0;
+ tso->par.exectime = 0;
+ tso->par.fetchtime = 0;
+ tso->par.fetchcount = 0;
+ tso->par.blocktime = 0;
+ tso->par.blockcount = 0;
+ tso->par.blockedat = 0;
+ tso->par.globalsparks = 0;
+ tso->par.localsparks = 0;
#endif
-
+
#if defined(GRAN)
- globalGranStats.tot_threads_created++;
- globalGranStats.threads_created_on_PE[CurrentProc]++;
- globalGranStats.tot_sq_len += spark_queue_len(CurrentProc);
- globalGranStats.tot_sq_probes++;
-#elif defined(PAR)
- // collect parallel global statistics (currently done together with GC stats)
- if (RtsFlags.ParFlags.ParStats.Global &&
- RtsFlags.GcFlags.giveStats > NO_GC_STATS) {
- //fprintf(stderr, "Creating thread %d @ %11.2f\n", tso->id, usertime());
- globalParStats.tot_threads_created++;
- }
+ globalGranStats.tot_threads_created++;
+ globalGranStats.threads_created_on_PE[CurrentProc]++;
+ globalGranStats.tot_sq_len += spark_queue_len(CurrentProc);
+ globalGranStats.tot_sq_probes++;
+#elif defined(PARALLEL_HASKELL)
+ // collect parallel global statistics (currently done together with GC stats)
+ if (RtsFlags.ParFlags.ParStats.Global &&
+ RtsFlags.GcFlags.giveStats > NO_GC_STATS) {
+ //debugBelch("Creating thread %d @ %11.2f\n", tso->id, usertime());
+ globalParStats.tot_threads_created++;
+ }
#endif
-
+
#if defined(GRAN)
- IF_GRAN_DEBUG(pri,
- belch("==__ schedule: Created TSO %d (%p);",
- CurrentProc, tso, tso->id));
-#elif defined(PAR)
+ IF_GRAN_DEBUG(pri,
+ sched_belch("==__ schedule: Created TSO %d (%p);",
+ CurrentProc, tso, tso->id));
+#elif defined(PARALLEL_HASKELL)
IF_PAR_DEBUG(verbose,
- belch("==__ schedule: Created TSO %d (%p); %d threads active",
- tso->id, tso, advisory_thread_count));
+ sched_belch("==__ schedule: Created TSO %d (%p); %d threads active",
+ (long)tso->id, tso, advisory_thread_count));
#else
- IF_DEBUG(scheduler,sched_belch("created thread %ld, stack size = %lx words",
- tso->id, tso->stack_size));
+ IF_DEBUG(scheduler,sched_belch("created thread %ld, stack size = %lx words",
+ (long)tso->id, (long)tso->stack_size));
#endif
- return tso;
+ return tso;
}
#if defined(PAR)
all parallel thread creation calls should fall through the following routine.
*/
StgTSO *
-createSparkThread(rtsSpark spark)
+createThreadFromSpark(rtsSpark spark)
{ StgTSO *tso;
ASSERT(spark != (rtsSpark)NULL);
+// JB: TAKE CARE OF THIS COUNTER! BUGGY
if (advisory_thread_count >= RtsFlags.ParFlags.maxThreads)
{ threadsIgnored++;
barf("{createSparkThread}Daq ghuH: refusing to create another thread; no more than %d threads allowed (currently %d)",
}
else
{ threadsCreated++;
- tso = createThread_(RtsFlags.GcFlags.initialStkSize, rtsTrue);
+ tso = createThread(RtsFlags.GcFlags.initialStkSize);
if (tso==END_TSO_QUEUE)
barf("createSparkThread: Cannot create TSO");
#if defined(DIST)
tso->priority = AdvisoryPriority;
#endif
pushClosure(tso,spark);
- PUSH_ON_RUN_QUEUE(tso);
- advisory_thread_count++;
+ addToRunQueue(tso);
+ advisory_thread_count++; // JB: TAKE CARE OF THIS COUNTER! BUGGY
}
return tso;
}
Turn a spark into a thread.
ToDo: fix for SMP (needs to acquire SCHED_MUTEX!)
*/
-#if defined(PAR)
-//@cindex activateSpark
+#if 0
StgTSO *
activateSpark (rtsSpark spark)
{
tso = createSparkThread(spark);
if (RtsFlags.ParFlags.ParStats.Full) {
//ASSERT(run_queue_hd == END_TSO_QUEUE); // I think ...
- IF_PAR_DEBUG(verbose,
- belch("==^^ activateSpark: turning spark of closure %p (%s) into a thread",
- (StgClosure *)spark, info_type((StgClosure *)spark)));
+ IF_PAR_DEBUG(verbose,
+ debugBelch("==^^ activateSpark: turning spark of closure %p (%s) into a thread\n",
+ (StgClosure *)spark, info_type((StgClosure *)spark)));
}
// ToDo: fwd info on local/global spark to thread -- HWL
// tso->gran.exported = spark->exported;
/* ---------------------------------------------------------------------------
* scheduleThread()
*
- * scheduleThread puts a thread on the head of the runnable queue.
+ * scheduleThread puts a thread on the end of the runnable queue.
* This will usually be done immediately after a thread is created.
* The caller of scheduleThread must create the thread using e.g.
* createThread and push an appropriate closure
* on this thread's stack before the scheduler is invoked.
* ------------------------------------------------------------------------ */
-static void scheduleThread_ (StgTSO* tso, rtsBool createTask);
-
void
-scheduleThread_(StgTSO *tso
- , rtsBool createTask
-#if !defined(THREADED_RTS)
- STG_UNUSED
-#endif
- )
+scheduleThread(Capability *cap, StgTSO *tso)
{
- ACQUIRE_LOCK(&sched_mutex);
+ // The thread goes at the *end* of the run-queue, to avoid possible
+ // starvation of any threads already on the queue.
+ appendToRunQueue(cap,tso);
+}
- /* Put the new thread on the head of the runnable queue. The caller
- * better push an appropriate closure on this thread's stack
- * beforehand. In the SMP case, the thread may start running as
- * soon as we release the scheduler lock below.
- */
- PUSH_ON_RUN_QUEUE(tso);
-#if defined(THREADED_RTS)
- /* If main() is scheduling a thread, don't bother creating a
- * new task.
- */
- if ( createTask ) {
- startTask(taskStart);
- }
-#endif
- THREAD_RUNNABLE();
+Capability *
+scheduleWaitThread (StgTSO* tso, /*[out]*/HaskellObj* ret, Capability *cap)
+{
+ Task *task;
-#if 0
- IF_DEBUG(scheduler,printTSO(tso));
+ // We already created/initialised the Task
+ task = cap->running_task;
+
+ // This TSO is now a bound thread; make the Task and TSO
+ // point to each other.
+ tso->bound = task;
+
+ task->tso = tso;
+ task->ret = ret;
+ task->stat = NoStatus;
+
+ appendToRunQueue(cap,tso);
+
+ IF_DEBUG(scheduler, sched_belch("new bound thread (%d)", tso->id));
+
+#if defined(GRAN)
+ /* GranSim specific init */
+ CurrentTSO = m->tso; // the TSO to run
+ procStatus[MainProc] = Busy; // status of main PE
+ CurrentProc = MainProc; // PE to run it on
#endif
- RELEASE_LOCK(&sched_mutex);
-}
-void scheduleThread(StgTSO* tso)
-{
- return scheduleThread_(tso, rtsFalse);
+ cap = schedule(cap,task);
+
+ ASSERT(task->stat != NoStatus);
+ ASSERT_FULL_CAPABILITY_INVARIANTS(cap,task);
+
+ IF_DEBUG(scheduler, sched_belch("bound thread (%d) finished", task->tso->id));
+ return cap;
}
-void scheduleExtThread(StgTSO* tso)
+/* ----------------------------------------------------------------------------
+ * Starting Tasks
+ * ------------------------------------------------------------------------- */
+
+#if defined(THREADED_RTS)
+void
+workerStart(Task *task)
{
- return scheduleThread_(tso, rtsTrue);
+ Capability *cap;
+
+ // See startWorkerTask().
+ ACQUIRE_LOCK(&task->lock);
+ cap = task->cap;
+ RELEASE_LOCK(&task->lock);
+
+ // set the thread-local pointer to the Task:
+ taskEnter(task);
+
+ // schedule() runs without a lock.
+ cap = schedule(cap,task);
+
+ // On exit from schedule(), we have a Capability.
+ releaseCapability(cap);
+ taskStop(task);
}
+#endif
/* ---------------------------------------------------------------------------
* initScheduler()
*
* ------------------------------------------------------------------------ */
-#ifdef SMP
-static void
-term_handler(int sig STG_UNUSED)
-{
- stat_workerStop();
- ACQUIRE_LOCK(&term_mutex);
- await_death--;
- RELEASE_LOCK(&term_mutex);
- shutdownThread();
-}
-#endif
-
void
initScheduler(void)
{
#if defined(GRAN)
nat i;
-
for (i=0; i<=MAX_PROC; i++) {
run_queue_hds[i] = END_TSO_QUEUE;
run_queue_tls[i] = END_TSO_QUEUE;
blocked_queue_hds[i] = END_TSO_QUEUE;
blocked_queue_tls[i] = END_TSO_QUEUE;
ccalling_threadss[i] = END_TSO_QUEUE;
+ blackhole_queue[i] = END_TSO_QUEUE;
sleeping_queue = END_TSO_QUEUE;
}
-#else
- run_queue_hd = END_TSO_QUEUE;
- run_queue_tl = END_TSO_QUEUE;
+#elif !defined(THREADED_RTS)
blocked_queue_hd = END_TSO_QUEUE;
blocked_queue_tl = END_TSO_QUEUE;
sleeping_queue = END_TSO_QUEUE;
-#endif
-
- suspended_ccalling_threads = END_TSO_QUEUE;
+#endif
- main_threads = NULL;
- all_threads = END_TSO_QUEUE;
+ blackhole_queue = END_TSO_QUEUE;
+ all_threads = END_TSO_QUEUE;
context_switch = 0;
- interrupted = 0;
+ sched_state = SCHED_RUNNING;
RtsFlags.ConcFlags.ctxtSwitchTicks =
RtsFlags.ConcFlags.ctxtSwitchTime / TICK_MILLISECS;
-#if defined(RTS_SUPPORTS_THREADS)
+#if defined(THREADED_RTS)
/* Initialise the mutex and condition variables used by
* the scheduler. */
initMutex(&sched_mutex);
- initMutex(&term_mutex);
-
- initCondition(&thread_ready_cond);
#endif
-#if defined(SMP)
- initCondition(&gc_pending_cond);
-#endif
-
-#if defined(RTS_SUPPORTS_THREADS)
ACQUIRE_LOCK(&sched_mutex);
-#endif
-
- /* Install the SIGHUP handler */
-#if defined(SMP)
- {
- struct sigaction action,oact;
-
- action.sa_handler = term_handler;
- sigemptyset(&action.sa_mask);
- action.sa_flags = 0;
- if (sigaction(SIGTERM, &action, &oact) != 0) {
- barf("can't install TERM handler");
- }
- }
-#endif
/* A capability holds the state a native thread needs in
* order to execute STG code. At least one capability is
- * floating around (only SMP builds have more than one).
+ * floating around (only THREADED_RTS builds have more than one).
*/
initCapabilities();
-
-#if defined(RTS_SUPPORTS_THREADS)
- /* start our haskell execution tasks */
-# if defined(SMP)
- startTaskManager(RtsFlags.ParFlags.nNodes, taskStart);
-# else
- startTaskManager(0,taskStart);
-# endif
-#endif
-#if /* defined(SMP) ||*/ defined(PAR)
+ initTaskManager();
+
+#if defined(THREADED_RTS) || defined(PARALLEL_HASKELL)
initSparkPools();
#endif
-#if defined(RTS_SUPPORTS_THREADS)
- RELEASE_LOCK(&sched_mutex);
+#if defined(THREADED_RTS)
+ /*
+ * Eagerly start one worker to run each Capability, except for
+ * Capability 0. The idea is that we're probably going to start a
+ * bound thread on Capability 0 pretty soon, so we don't want a
+ * worker task hogging it.
+ */
+ {
+ nat i;
+ Capability *cap;
+ for (i = 1; i < n_capabilities; i++) {
+ cap = &capabilities[i];
+ ACQUIRE_LOCK(&cap->lock);
+ startWorkerTask(cap, workerStart);
+ RELEASE_LOCK(&cap->lock);
+ }
+ }
#endif
+ RELEASE_LOCK(&sched_mutex);
}
void
exitScheduler( void )
{
-#if defined(RTS_SUPPORTS_THREADS)
- stopTaskManager();
-#endif
-}
-
-/* -----------------------------------------------------------------------------
- Managing the per-task allocation areas.
-
- Each capability comes with an allocation area. These are
- fixed-length block lists into which allocation can be done.
-
- ToDo: no support for two-space collection at the moment???
- -------------------------------------------------------------------------- */
-
-/* -----------------------------------------------------------------------------
- * waitThread is the external interface for running a new computation
- * and waiting for the result.
- *
- * In the non-SMP case, we create a new main thread, push it on the
- * main-thread stack, and invoke the scheduler to run it. The
- * scheduler will return when the top main thread on the stack has
- * completed or died, and fill in the necessary fields of the
- * main_thread structure.
- *
- * In the SMP case, we create a main thread as before, but we then
- * create a new condition variable and sleep on it. When our new
- * main thread has completed, we'll be woken up and the status/result
- * will be in the main_thread struct.
- * -------------------------------------------------------------------------- */
-
-int
-howManyThreadsAvail ( void )
-{
- int i = 0;
- StgTSO* q;
- for (q = run_queue_hd; q != END_TSO_QUEUE; q = q->link)
- i++;
- for (q = blocked_queue_hd; q != END_TSO_QUEUE; q = q->link)
- i++;
- for (q = sleeping_queue; q != END_TSO_QUEUE; q = q->link)
- i++;
- return i;
-}
-
-void
-finishAllThreads ( void )
-{
- do {
- while (run_queue_hd != END_TSO_QUEUE) {
- waitThread ( run_queue_hd, NULL);
- }
- while (blocked_queue_hd != END_TSO_QUEUE) {
- waitThread ( blocked_queue_hd, NULL);
- }
- while (sleeping_queue != END_TSO_QUEUE) {
- waitThread ( blocked_queue_hd, NULL);
- }
- } while
- (blocked_queue_hd != END_TSO_QUEUE ||
- run_queue_hd != END_TSO_QUEUE ||
- sleeping_queue != END_TSO_QUEUE);
-}
-
-SchedulerStatus
-waitThread(StgTSO *tso, /*out*/StgClosure **ret)
-{
-#if defined(THREADED_RTS)
- return waitThread_(tso,ret, rtsFalse);
-#else
- return waitThread_(tso,ret);
-#endif
-}
+ Task *task = NULL;
-SchedulerStatus
-waitThread_(StgTSO *tso,
- /*out*/StgClosure **ret
#if defined(THREADED_RTS)
- , rtsBool blockWaiting
-#endif
- )
-{
- StgMainThread *m;
- SchedulerStatus stat;
-
- ACQUIRE_LOCK(&sched_mutex);
-
- m = stgMallocBytes(sizeof(StgMainThread), "waitThread");
-
- m->tso = tso;
- m->ret = ret;
- m->stat = NoStatus;
-#if defined(RTS_SUPPORTS_THREADS)
- initCondition(&m->wakeup);
-#endif
-
- m->link = main_threads;
- main_threads = m;
-
- IF_DEBUG(scheduler, sched_belch("== scheduler: new main thread (%d)\n", m->tso->id));
-
-#if defined(RTS_SUPPORTS_THREADS)
-
-# if defined(THREADED_RTS)
- if (!blockWaiting) {
- /* In the threaded case, the OS thread that called main()
- * gets to enter the RTS directly without going via another
- * task/thread.
- */
+ ACQUIRE_LOCK(&sched_mutex);
+ task = newBoundTask();
RELEASE_LOCK(&sched_mutex);
- schedule();
- ASSERT(m->stat != NoStatus);
- } else
-# endif
- {
- IF_DEBUG(scheduler, sched_belch("sfoo"));
- do {
- waitCondition(&m->wakeup, &sched_mutex);
- } while (m->stat == NoStatus);
- }
-#elif defined(GRAN)
- /* GranSim specific init */
- CurrentTSO = m->tso; // the TSO to run
- procStatus[MainProc] = Busy; // status of main PE
- CurrentProc = MainProc; // PE to run it on
-
- schedule();
-#else
- RELEASE_LOCK(&sched_mutex);
- schedule();
- ASSERT(m->stat != NoStatus);
-#endif
-
- stat = m->stat;
-
-#if defined(RTS_SUPPORTS_THREADS)
- closeCondition(&m->wakeup);
#endif
- IF_DEBUG(scheduler, fprintf(stderr, "== scheduler: main thread (%d) finished\n",
- m->tso->id));
- free(m);
+ // If we haven't killed all the threads yet, do it now.
+ if (sched_state < SCHED_INTERRUPTED) {
+ sched_state = SCHED_INTERRUPTING;
+ scheduleDoGC(NULL,task,rtsFalse,GetRoots);
+ }
+ sched_state = SCHED_SHUTTING_DOWN;
#if defined(THREADED_RTS)
- if (blockWaiting)
-#endif
- RELEASE_LOCK(&sched_mutex);
-
- return stat;
-}
-
-//@node Run queue code, Garbage Collextion Routines, Suspend and Resume, Main scheduling code
-//@subsection Run queue code
-
-#if 0
-/*
- NB: In GranSim we have many run queues; run_queue_hd is actually a macro
- unfolding to run_queue_hds[CurrentProc], thus CurrentProc is an
- implicit global variable that has to be correct when calling these
- fcts -- HWL
-*/
-
-/* Put the new thread on the head of the runnable queue.
- * The caller of createThread better push an appropriate closure
- * on this thread's stack before the scheduler is invoked.
- */
-static /* inline */ void
-add_to_run_queue(tso)
-StgTSO* tso;
-{
- ASSERT(tso!=run_queue_hd && tso!=run_queue_tl);
- tso->link = run_queue_hd;
- run_queue_hd = tso;
- if (run_queue_tl == END_TSO_QUEUE) {
- run_queue_tl = tso;
- }
-}
-
-/* Put the new thread at the end of the runnable queue. */
-static /* inline */ void
-push_on_run_queue(tso)
-StgTSO* tso;
-{
- ASSERT(get_itbl((StgClosure *)tso)->type == TSO);
- ASSERT(run_queue_hd!=NULL && run_queue_tl!=NULL);
- ASSERT(tso!=run_queue_hd && tso!=run_queue_tl);
- if (run_queue_hd == END_TSO_QUEUE) {
- run_queue_hd = tso;
- } else {
- run_queue_tl->link = tso;
- }
- run_queue_tl = tso;
-}
-
-/*
- Should be inlined because it's used very often in schedule. The tso
- argument is actually only needed in GranSim, where we want to have the
- possibility to schedule *any* TSO on the run queue, irrespective of the
- actual ordering. Therefore, if tso is not the nil TSO then we traverse
- the run queue and dequeue the tso, adjusting the links in the queue.
-*/
-//@cindex take_off_run_queue
-static /* inline */ StgTSO*
-take_off_run_queue(StgTSO *tso) {
- StgTSO *t, *prev;
-
- /*
- qetlaHbogh Qu' ngaSbogh ghomDaQ {tso} yIteq!
-
- if tso is specified, unlink that tso from the run_queue (doesn't have
- to be at the beginning of the queue); GranSim only
- */
- if (tso!=END_TSO_QUEUE) {
- /* find tso in queue */
- for (t=run_queue_hd, prev=END_TSO_QUEUE;
- t!=END_TSO_QUEUE && t!=tso;
- prev=t, t=t->link)
- /* nothing */ ;
- ASSERT(t==tso);
- /* now actually dequeue the tso */
- if (prev!=END_TSO_QUEUE) {
- ASSERT(run_queue_hd!=t);
- prev->link = t->link;
- } else {
- /* t is at beginning of thread queue */
- ASSERT(run_queue_hd==t);
- run_queue_hd = t->link;
- }
- /* t is at end of thread queue */
- if (t->link==END_TSO_QUEUE) {
- ASSERT(t==run_queue_tl);
- run_queue_tl = prev;
- } else {
- ASSERT(run_queue_tl!=t);
- }
- t->link = END_TSO_QUEUE;
- } else {
- /* take tso from the beginning of the queue; std concurrent code */
- t = run_queue_hd;
- if (t != END_TSO_QUEUE) {
- run_queue_hd = t->link;
- t->link = END_TSO_QUEUE;
- if (run_queue_hd == END_TSO_QUEUE) {
- run_queue_tl = END_TSO_QUEUE;
- }
+ {
+ nat i;
+
+ for (i = 0; i < n_capabilities; i++) {
+ shutdownCapability(&capabilities[i], task);
+ }
+ boundTaskExiting(task);
+ stopTaskManager();
}
- }
- return t;
+#endif
}
-#endif /* 0 */
-
-//@node Garbage Collextion Routines, Blocking Queue Routines, Run queue code, Main scheduling code
-//@subsection Garbage Collextion Routines
-
/* ---------------------------------------------------------------------------
Where are the roots that we know about?
*/
void
-GetRoots(evac_fn evac)
+GetRoots( evac_fn evac )
{
- StgMainThread *m;
+ nat i;
+ Capability *cap;
+ Task *task;
#if defined(GRAN)
- {
- nat i;
for (i=0; i<=RtsFlags.GranFlags.proc; i++) {
- if ((run_queue_hds[i] != END_TSO_QUEUE) && ((run_queue_hds[i] != NULL)))
- evac((StgClosure **)&run_queue_hds[i]);
- if ((run_queue_tls[i] != END_TSO_QUEUE) && ((run_queue_tls[i] != NULL)))
- evac((StgClosure **)&run_queue_tls[i]);
-
- if ((blocked_queue_hds[i] != END_TSO_QUEUE) && ((blocked_queue_hds[i] != NULL)))
- evac((StgClosure **)&blocked_queue_hds[i]);
- if ((blocked_queue_tls[i] != END_TSO_QUEUE) && ((blocked_queue_tls[i] != NULL)))
- evac((StgClosure **)&blocked_queue_tls[i]);
- if ((ccalling_threadss[i] != END_TSO_QUEUE) && ((ccalling_threadss[i] != NULL)))
- evac((StgClosure **)&ccalling_threads[i]);
+ if ((run_queue_hds[i] != END_TSO_QUEUE) && ((run_queue_hds[i] != NULL)))
+ evac((StgClosure **)&run_queue_hds[i]);
+ if ((run_queue_tls[i] != END_TSO_QUEUE) && ((run_queue_tls[i] != NULL)))
+ evac((StgClosure **)&run_queue_tls[i]);
+
+ if ((blocked_queue_hds[i] != END_TSO_QUEUE) && ((blocked_queue_hds[i] != NULL)))
+ evac((StgClosure **)&blocked_queue_hds[i]);
+ if ((blocked_queue_tls[i] != END_TSO_QUEUE) && ((blocked_queue_tls[i] != NULL)))
+ evac((StgClosure **)&blocked_queue_tls[i]);
+ if ((ccalling_threadss[i] != END_TSO_QUEUE) && ((ccalling_threadss[i] != NULL)))
+ evac((StgClosure **)&ccalling_threads[i]);
}
- }
- markEventQueue();
+ markEventQueue();
#else /* !GRAN */
- if (run_queue_hd != END_TSO_QUEUE) {
- ASSERT(run_queue_tl != END_TSO_QUEUE);
- evac((StgClosure **)&run_queue_hd);
- evac((StgClosure **)&run_queue_tl);
- }
-
- if (blocked_queue_hd != END_TSO_QUEUE) {
- ASSERT(blocked_queue_tl != END_TSO_QUEUE);
- evac((StgClosure **)&blocked_queue_hd);
- evac((StgClosure **)&blocked_queue_tl);
- }
-
- if (sleeping_queue != END_TSO_QUEUE) {
- evac((StgClosure **)&sleeping_queue);
- }
+
+ for (i = 0; i < n_capabilities; i++) {
+ cap = &capabilities[i];
+ evac((StgClosure **)&cap->run_queue_hd);
+ evac((StgClosure **)&cap->run_queue_tl);
+
+ for (task = cap->suspended_ccalling_tasks; task != NULL;
+ task=task->next) {
+ IF_DEBUG(scheduler,sched_belch("evac'ing suspended TSO %d", task->suspended_tso->id));
+ evac((StgClosure **)&task->suspended_tso);
+ }
+ }
+
+#if !defined(THREADED_RTS)
+ evac((StgClosure **)(void *)&blocked_queue_hd);
+ evac((StgClosure **)(void *)&blocked_queue_tl);
+ evac((StgClosure **)(void *)&sleeping_queue);
#endif
+#endif
- if (suspended_ccalling_threads != END_TSO_QUEUE) {
- evac((StgClosure **)&suspended_ccalling_threads);
- }
+ // evac((StgClosure **)&blackhole_queue);
-#if defined(PAR) || defined(GRAN)
- markSparkQueue(evac);
+#if defined(THREADED_RTS) || defined(PARALLEL_HASKELL) || defined(GRAN)
+ markSparkQueue(evac);
+#endif
+
+#if defined(RTS_USER_SIGNALS)
+ // mark the signal handlers (signals should be already blocked)
+ markSignalHandlers(evac);
#endif
}
This needs to be protected by the GC condition variable above. KH.
-------------------------------------------------------------------------- */
-void (*extra_roots)(evac_fn);
+static void (*extra_roots)(evac_fn);
+
+static void
+performGC_(rtsBool force_major, void (*get_roots)(evac_fn))
+{
+ Task *task = myTask();
+
+ if (task == NULL) {
+ ACQUIRE_LOCK(&sched_mutex);
+ task = newBoundTask();
+ RELEASE_LOCK(&sched_mutex);
+ scheduleDoGC(NULL,task,force_major, get_roots);
+ boundTaskExiting(task);
+ } else {
+ scheduleDoGC(NULL,task,force_major, get_roots);
+ }
+}
void
performGC(void)
{
- /* Obligated to hold this lock upon entry */
- ACQUIRE_LOCK(&sched_mutex);
- GarbageCollect(GetRoots,rtsFalse);
- RELEASE_LOCK(&sched_mutex);
+ performGC_(rtsFalse, GetRoots);
}
void
performMajorGC(void)
{
- ACQUIRE_LOCK(&sched_mutex);
- GarbageCollect(GetRoots,rtsTrue);
- RELEASE_LOCK(&sched_mutex);
+ performGC_(rtsTrue, GetRoots);
}
static void
void
performGCWithRoots(void (*get_roots)(evac_fn))
{
- ACQUIRE_LOCK(&sched_mutex);
- extra_roots = get_roots;
- GarbageCollect(AllRoots,rtsFalse);
- RELEASE_LOCK(&sched_mutex);
+ extra_roots = get_roots;
+ performGC_(rtsFalse, AllRoots);
}
/* -----------------------------------------------------------------------------
-------------------------------------------------------------------------- */
static StgTSO *
-threadStackOverflow(StgTSO *tso)
+threadStackOverflow(Capability *cap, StgTSO *tso)
{
- nat new_stack_size, new_tso_size, diff, stack_words;
+ nat new_stack_size, stack_words;
+ lnat new_tso_size;
StgPtr new_sp;
StgTSO *dest;
if (tso->stack_size >= tso->max_stack_size) {
IF_DEBUG(gc,
- belch("@@ threadStackOverflow of TSO %d (%p): stack too large (now %ld; max is %ld",
- tso->id, tso, tso->stack_size, tso->max_stack_size);
+ debugBelch("@@ threadStackOverflow of TSO %ld (%p): stack too large (now %ld; max is %ld)\n",
+ (long)tso->id, tso, (long)tso->stack_size, (long)tso->max_stack_size);
/* If we're debugging, just print out the top of the stack */
printStackChunk(tso->sp, stg_min(tso->stack+tso->stack_size,
tso->sp+64)));
/* Send this thread the StackOverflow exception */
- raiseAsync(tso, (StgClosure *)stackOverflow_closure);
+ raiseAsync(cap, tso, (StgClosure *)stackOverflow_closure);
return tso;
}
* Finally round up so the TSO ends up as a whole number of blocks.
*/
new_stack_size = stg_min(tso->stack_size * 2, tso->max_stack_size);
- new_tso_size = (nat)BLOCK_ROUND_UP(new_stack_size * sizeof(W_) +
+ new_tso_size = (lnat)BLOCK_ROUND_UP(new_stack_size * sizeof(W_) +
TSO_STRUCT_SIZE)/sizeof(W_);
new_tso_size = round_to_mblocks(new_tso_size); /* Be MBLOCK-friendly */
new_stack_size = new_tso_size - TSO_STRUCT_SIZEW;
- IF_DEBUG(scheduler, fprintf(stderr,"== scheduler: increasing stack size from %d words to %d.\n", tso->stack_size, new_stack_size));
+ IF_DEBUG(scheduler, sched_belch("increasing stack size from %ld words to %d.\n", (long)tso->stack_size, new_stack_size));
dest = (StgTSO *)allocate(new_tso_size);
TICK_ALLOC_TSO(new_stack_size,0);
memcpy(new_sp, tso->sp, stack_words * sizeof(W_));
/* relocate the stack pointers... */
- diff = (P_)new_sp - (P_)tso->sp; /* In *words* */
- dest->su = (StgUpdateFrame *) ((P_)dest->su + diff);
- dest->sp = new_sp;
+ dest->sp = new_sp;
dest->stack_size = new_stack_size;
- /* and relocate the update frame list */
- relocate_stack(dest, diff);
-
/* Mark the old TSO as relocated. We have to check for relocated
* TSOs in the garbage collector and any primops that deal with TSOs.
*
- * It's important to set the sp and su values to just beyond the end
+ * It's important to set the sp value to just beyond the end
* of the stack, so we don't attempt to scavenge any part of the
* dead TSO's stack.
*/
tso->what_next = ThreadRelocated;
tso->link = dest;
tso->sp = (P_)&(tso->stack[tso->stack_size]);
- tso->su = (StgUpdateFrame *)tso->sp;
tso->why_blocked = NotBlocked;
- dest->mut_link = NULL;
IF_PAR_DEBUG(verbose,
- belch("@@ threadStackOverflow of TSO %d (now at %p): stack size increased to %ld",
+ debugBelch("@@ threadStackOverflow of TSO %d (now at %p): stack size increased to %ld\n",
tso->id, tso, tso->stack_size);
/* If we're debugging, just print out the top of the stack */
printStackChunk(tso->sp, stg_min(tso->stack+tso->stack_size,
return dest;
}
-//@node Blocking Queue Routines, Exception Handling Routines, Garbage Collextion Routines, Main scheduling code
-//@subsection Blocking Queue Routines
-
/* ---------------------------------------------------------------------------
Wake up a queue that was blocked on some resource.
------------------------------------------------------------------------ */
#if defined(GRAN)
-static inline void
+STATIC_INLINE void
unblockCount ( StgBlockingQueueElement *bqe, StgClosure *node )
{
}
-#elif defined(PAR)
-static inline void
+#elif defined(PARALLEL_HASKELL)
+STATIC_INLINE void
unblockCount ( StgBlockingQueueElement *bqe, StgClosure *node )
{
/* write RESUME events to log file and
DumpRawGranEvent(CURRENT_PROC, CURRENT_PROC,
GR_RESUMEQ, ((StgTSO *)bqe), ((StgTSO *)bqe)->block_info.closure,
0, 0 /* spark_queue_len(ADVISORY_POOL) */);
- if (EMPTY_RUN_QUEUE())
+ if (emptyRunQueue())
emitSchedule = rtsTrue;
switch (get_itbl(node)->type) {
break;
#endif
default:
- barf("{unblockOneLocked}Daq Qagh: unexpected closure in blocking queue");
+ barf("{unblockOne}Daq Qagh: unexpected closure in blocking queue");
}
}
}
#endif
#if defined(GRAN)
-static StgBlockingQueueElement *
-unblockOneLocked(StgBlockingQueueElement *bqe, StgClosure *node)
+StgBlockingQueueElement *
+unblockOne(StgBlockingQueueElement *bqe, StgClosure *node)
{
StgTSO *tso;
PEs node_loc, tso_loc;
}
/* the thread-queue-overhead is accounted for in either Resume or UnblockThread */
IF_GRAN_DEBUG(bq,
- fprintf(stderr," %s TSO %d (%p) [PE %d] (block_info.closure=%p) (next=%p) ,",
+ debugBelch(" %s TSO %d (%p) [PE %d] (block_info.closure=%p) (next=%p) ,",
(node_loc==tso_loc ? "Local" : "Global"),
tso->id, tso, CurrentProc, tso->block_info.closure, tso->link));
tso->block_info.closure = NULL;
- IF_DEBUG(scheduler,belch("-- Waking up thread %ld (%p)",
+ IF_DEBUG(scheduler,debugBelch("-- Waking up thread %ld (%p)\n",
tso->id, tso));
}
-#elif defined(PAR)
-static StgBlockingQueueElement *
-unblockOneLocked(StgBlockingQueueElement *bqe, StgClosure *node)
+#elif defined(PARALLEL_HASKELL)
+StgBlockingQueueElement *
+unblockOne(StgBlockingQueueElement *bqe, StgClosure *node)
{
StgBlockingQueueElement *next;
ASSERT(((StgTSO *)bqe)->why_blocked != NotBlocked);
/* if it's a TSO just push it onto the run_queue */
next = bqe->link;
- // ((StgTSO *)bqe)->link = END_TSO_QUEUE; // debugging?
- PUSH_ON_RUN_QUEUE((StgTSO *)bqe);
- THREAD_RUNNABLE();
+ ((StgTSO *)bqe)->link = END_TSO_QUEUE; // debugging?
+ APPEND_TO_RUN_QUEUE((StgTSO *)bqe);
+ threadRunnable();
unblockCount(bqe, node);
/* reset blocking status after dumping event */
((StgTSO *)bqe)->why_blocked = NotBlocked;
break;
default:
- barf("{unblockOneLocked}Daq Qagh: Unexpected IP (%#lx; %s) in blocking queue at %#lx\n",
+ barf("{unblockOne}Daq Qagh: Unexpected IP (%#lx; %s) in blocking queue at %#lx\n",
get_itbl((StgClosure *)bqe), info_type((StgClosure *)bqe),
(StgClosure *)bqe);
# endif
}
- IF_PAR_DEBUG(bq, fprintf(stderr, ", %p (%s)", bqe, info_type((StgClosure*)bqe)));
+ IF_PAR_DEBUG(bq, debugBelch(", %p (%s)\n", bqe, info_type((StgClosure*)bqe)));
return next;
}
+#endif
-#else /* !GRAN && !PAR */
-static StgTSO *
-unblockOneLocked(StgTSO *tso)
+StgTSO *
+unblockOne(Capability *cap, StgTSO *tso)
{
StgTSO *next;
ASSERT(tso->why_blocked != NotBlocked);
tso->why_blocked = NotBlocked;
next = tso->link;
- PUSH_ON_RUN_QUEUE(tso);
- THREAD_RUNNABLE();
- IF_DEBUG(scheduler,sched_belch("waking up thread %ld", tso->id));
+ tso->link = END_TSO_QUEUE;
+
+ // We might have just migrated this TSO to our Capability:
+ if (tso->bound) {
+ tso->bound->cap = cap;
+ }
+
+ appendToRunQueue(cap,tso);
+
+ // we're holding a newly woken thread, make sure we context switch
+ // quickly so we can migrate it if necessary.
+ context_switch = 1;
+ IF_DEBUG(scheduler,sched_belch("waking up thread %ld", (long)tso->id));
return next;
}
-#endif
-#if defined(GRAN) || defined(PAR)
-inline StgBlockingQueueElement *
-unblockOne(StgBlockingQueueElement *bqe, StgClosure *node)
-{
- ACQUIRE_LOCK(&sched_mutex);
- bqe = unblockOneLocked(bqe, node);
- RELEASE_LOCK(&sched_mutex);
- return bqe;
-}
-#else
-inline StgTSO *
-unblockOne(StgTSO *tso)
-{
- ACQUIRE_LOCK(&sched_mutex);
- tso = unblockOneLocked(tso);
- RELEASE_LOCK(&sched_mutex);
- return tso;
-}
-#endif
#if defined(GRAN)
void
nat len = 0;
IF_GRAN_DEBUG(bq,
- belch("##-_ AwBQ for node %p on PE %d @ %ld by TSO %d (%p): ", \
+ debugBelch("##-_ AwBQ for node %p on PE %d @ %ld by TSO %d (%p): \n", \
node, CurrentProc, CurrentTime[CurrentProc],
CurrentTSO->id, CurrentTSO));
*/
if (CurrentProc!=node_loc) {
IF_GRAN_DEBUG(bq,
- belch("## node %p is on PE %d but CurrentProc is %d (TSO %d); assuming fake fetch and adjusting bitmask (old: %#x)",
+ debugBelch("## node %p is on PE %d but CurrentProc is %d (TSO %d); assuming fake fetch and adjusting bitmask (old: %#x)\n",
node, node_loc, CurrentProc, CurrentTSO->id,
// CurrentTSO, where_is(CurrentTSO),
node->header.gran.procs));
node->header.gran.procs = (node->header.gran.procs) | PE_NUMBER(CurrentProc);
IF_GRAN_DEBUG(bq,
- belch("## new bitmask of node %p is %#x",
+ debugBelch("## new bitmask of node %p is %#x\n",
node, node->header.gran.procs));
if (RtsFlags.GranFlags.GranSimStats.Global) {
globalGranStats.tot_fake_fetches++;
//tso = (StgTSO *)bqe; // wastes an assignment to get the type right
//tso_loc = where_is(tso);
len++;
- bqe = unblockOneLocked(bqe, node);
+ bqe = unblockOne(bqe, node);
}
/* if this is the BQ of an RBH, we have to put back the info ripped out of
((StgRBH *)node)->mut_link = (StgMutClosure *)((StgRBHSave *)bqe)->payload[1];
IF_GRAN_DEBUG(bq,
- belch("## Filled in RBH_Save for %p (%s) at end of AwBQ",
+ debugBelch("## Filled in RBH_Save for %p (%s) at end of AwBQ\n",
node, info_type(node)));
}
globalGranStats.tot_awbq++; // total no. of bqs awakened
}
IF_GRAN_DEBUG(bq,
- fprintf(stderr,"## BQ Stats of %p: [%d entries] %s\n",
+ debugBelch("## BQ Stats of %p: [%d entries] %s\n",
node, len, (bqe!=END_BQ_QUEUE) ? "RBH" : ""));
}
-#elif defined(PAR)
+#elif defined(PARALLEL_HASKELL)
void
awakenBlockedQueue(StgBlockingQueueElement *q, StgClosure *node)
{
StgBlockingQueueElement *bqe;
- ACQUIRE_LOCK(&sched_mutex);
-
IF_PAR_DEBUG(verbose,
- belch("##-_ AwBQ for node %p on [%x]: ",
+ debugBelch("##-_ AwBQ for node %p on [%x]: \n",
node, mytid));
#ifdef DIST
//RFP
if(get_itbl(q)->type == CONSTR || q==END_BQ_QUEUE) {
- IF_PAR_DEBUG(verbose, belch("## ... nothing to unblock so lets just return. RFP (BUG?)"));
+ IF_PAR_DEBUG(verbose, debugBelch("## ... nothing to unblock so lets just return. RFP (BUG?)\n"));
return;
}
#endif
bqe = q;
while (get_itbl(bqe)->type==TSO ||
get_itbl(bqe)->type==BLOCKED_FETCH) {
- bqe = unblockOneLocked(bqe, node);
+ bqe = unblockOne(bqe, node);
}
- RELEASE_LOCK(&sched_mutex);
}
-#else /* !GRAN && !PAR */
+#else /* !GRAN && !PARALLEL_HASKELL */
+
void
-awakenBlockedQueue(StgTSO *tso)
+awakenBlockedQueue(Capability *cap, StgTSO *tso)
{
- ACQUIRE_LOCK(&sched_mutex);
- while (tso != END_TSO_QUEUE) {
- tso = unblockOneLocked(tso);
- }
- RELEASE_LOCK(&sched_mutex);
+ if (tso == NULL) return; // hack; see bug #1235728, and comments in
+ // Exception.cmm
+ while (tso != END_TSO_QUEUE) {
+ tso = unblockOne(cap,tso);
+ }
}
#endif
-//@node Exception Handling Routines, Debugging Routines, Blocking Queue Routines, Main scheduling code
-//@subsection Exception Handling Routines
-
/* ---------------------------------------------------------------------------
Interrupt execution
- usually called inside a signal handler so it mustn't do anything fancy.
void
interruptStgRts(void)
{
- interrupted = 1;
+ sched_state = SCHED_INTERRUPTING;
context_switch = 1;
+#if defined(THREADED_RTS)
+ prodAllCapabilities();
+#endif
}
/* -----------------------------------------------------------------------------
This has nothing to do with the UnblockThread event in GranSim. -- HWL
-------------------------------------------------------------------------- */
-#if defined(GRAN) || defined(PAR)
+#if defined(GRAN) || defined(PARALLEL_HASKELL)
/*
NB: only the type of the blocking queue is different in GranSim and GUM
the operations on the queue-elements are the same
long live polymorphism!
+
+ Locks: sched_mutex is held upon entry and exit.
+
*/
static void
-unblockThread(StgTSO *tso)
+unblockThread(Capability *cap, StgTSO *tso)
{
StgBlockingQueueElement *t, **last;
- ACQUIRE_LOCK(&sched_mutex);
switch (tso->why_blocked) {
case NotBlocked:
return; /* not blocked */
+ case BlockedOnSTM:
+ // Be careful: nothing to do here! We tell the scheduler that the thread
+ // is runnable and we leave it to the stack-walking code to abort the
+ // transaction while unwinding the stack. We should perhaps have a debugging
+ // test to make sure that this really happens and that the 'zombie' transaction
+ // does not get committed.
+ goto done;
+
case BlockedOnMVar:
ASSERT(get_itbl(tso->block_info.closure)->type == MVAR);
{
case BlockedOnRead:
case BlockedOnWrite:
+#if defined(mingw32_HOST_OS)
+ case BlockedOnDoProc:
+#endif
{
/* take TSO off blocked_queue */
StgBlockingQueueElement *prev = NULL;
blocked_queue_tl = (StgTSO *)prev;
}
}
+#if defined(mingw32_HOST_OS)
+ /* (Cooperatively) signal that the worker thread should abort
+ * the request.
+ */
+ abandonWorkRequest(tso->block_info.async_result->reqID);
+#endif
goto done;
}
}
goto done;
}
}
- barf("unblockThread (I/O): TSO not found");
+ barf("unblockThread (delay): TSO not found");
}
default:
tso->link = END_TSO_QUEUE;
tso->why_blocked = NotBlocked;
tso->block_info.closure = NULL;
- PUSH_ON_RUN_QUEUE(tso);
- RELEASE_LOCK(&sched_mutex);
+ pushOnRunQueue(cap,tso);
}
#else
static void
-unblockThread(StgTSO *tso)
+unblockThread(Capability *cap, StgTSO *tso)
{
StgTSO *t, **last;
+
+ /* To avoid locking unnecessarily. */
+ if (tso->why_blocked == NotBlocked) {
+ return;
+ }
- ACQUIRE_LOCK(&sched_mutex);
switch (tso->why_blocked) {
- case NotBlocked:
- return; /* not blocked */
+ case BlockedOnSTM:
+ // Be careful: nothing to do here! We tell the scheduler that the thread
+ // is runnable and we leave it to the stack-walking code to abort the
+ // transaction while unwinding the stack. We should perhaps have a debugging
+ // test to make sure that this really happens and that the 'zombie' transaction
+ // does not get committed.
+ goto done;
case BlockedOnMVar:
ASSERT(get_itbl(tso->block_info.closure)->type == MVAR);
}
case BlockedOnBlackHole:
- ASSERT(get_itbl(tso->block_info.closure)->type == BLACKHOLE_BQ);
{
- StgBlockingQueue *bq = (StgBlockingQueue *)(tso->block_info.closure);
-
- last = &bq->blocking_queue;
- for (t = bq->blocking_queue; t != END_TSO_QUEUE;
+ last = &blackhole_queue;
+ for (t = blackhole_queue; t != END_TSO_QUEUE;
last = &t->link, t = t->link) {
if (t == tso) {
*last = tso->link;
barf("unblockThread (Exception): TSO not found");
}
+#if !defined(THREADED_RTS)
case BlockedOnRead:
case BlockedOnWrite:
+#if defined(mingw32_HOST_OS)
+ case BlockedOnDoProc:
+#endif
{
StgTSO *prev = NULL;
for (t = blocked_queue_hd; t != END_TSO_QUEUE;
blocked_queue_tl = prev;
}
}
+#if defined(mingw32_HOST_OS)
+ /* (Cooperatively) signal that the worker thread should abort
+ * the request.
+ */
+ abandonWorkRequest(tso->block_info.async_result->reqID);
+#endif
goto done;
}
}
goto done;
}
}
- barf("unblockThread (I/O): TSO not found");
+ barf("unblockThread (delay): TSO not found");
}
+#endif
default:
barf("unblockThread");
tso->link = END_TSO_QUEUE;
tso->why_blocked = NotBlocked;
tso->block_info.closure = NULL;
- PUSH_ON_RUN_QUEUE(tso);
- RELEASE_LOCK(&sched_mutex);
+ appendToRunQueue(cap,tso);
+
+ // We might have just migrated this TSO to our Capability:
+ if (tso->bound) {
+ tso->bound->cap = cap;
+ }
}
#endif
/* -----------------------------------------------------------------------------
+ * checkBlackHoles()
+ *
+ * Check the blackhole_queue for threads that can be woken up. We do
+ * this periodically: before every GC, and whenever the run queue is
+ * empty.
+ *
+ * An elegant solution might be to just wake up all the blocked
+ * threads with awakenBlockedQueue occasionally: they'll go back to
+ * sleep again if the object is still a BLACKHOLE. Unfortunately this
+ * doesn't give us a way to tell whether we've actually managed to
+ * wake up any threads, so we would be busy-waiting.
+ *
+ * -------------------------------------------------------------------------- */
+
+static rtsBool
+checkBlackHoles (Capability *cap)
+{
+ StgTSO **prev, *t;
+ rtsBool any_woke_up = rtsFalse;
+ StgHalfWord type;
+
+ // blackhole_queue is global:
+ ASSERT_LOCK_HELD(&sched_mutex);
+
+ IF_DEBUG(scheduler, sched_belch("checking threads blocked on black holes"));
+
+ // ASSUMES: sched_mutex
+ prev = &blackhole_queue;
+ t = blackhole_queue;
+ while (t != END_TSO_QUEUE) {
+ ASSERT(t->why_blocked == BlockedOnBlackHole);
+ type = get_itbl(t->block_info.closure)->type;
+ if (type != BLACKHOLE && type != CAF_BLACKHOLE) {
+ IF_DEBUG(sanity,checkTSO(t));
+ t = unblockOne(cap, t);
+ // urk, the threads migrate to the current capability
+ // here, but we'd like to keep them on the original one.
+ *prev = t;
+ any_woke_up = rtsTrue;
+ } else {
+ prev = &t->link;
+ t = t->link;
+ }
+ }
+
+ return any_woke_up;
+}
+
+/* -----------------------------------------------------------------------------
* raiseAsync()
*
* The following function implements the magic for raising an
* the top of the stack.
*
* How exactly do we save all the active computations? We create an
- * AP_UPD for every UpdateFrame on the stack. Entering one of these
- * AP_UPDs pushes everything from the corresponding update frame
+ * AP_STACK for every UpdateFrame on the stack. Entering one of these
+ * AP_STACKs pushes everything from the corresponding update frame
* upwards onto the stack. (Actually, it pushes everything up to the
- * next update frame plus a pointer to the next AP_UPD object.
- * Entering the next AP_UPD object pushes more onto the stack until we
- * reach the last AP_UPD object - at which point the stack should look
+ * next update frame plus a pointer to the next AP_STACK object.
+ * Entering the next AP_STACK object pushes more onto the stack until we
+ * reach the last AP_STACK object - at which point the stack should look
* exactly as it did when we killed the TSO and we can continue
* execution by entering the closure on top of the stack.
*
* CATCH_FRAME on the stack. In either case, we strip the entire
* stack and replace the thread with a zombie.
*
+ * ToDo: in THREADED_RTS mode, this function is only safe if either
+ * (a) we hold all the Capabilities (eg. in GC, or if there is only
+ * one Capability), or (b) we own the Capability that the TSO is
+ * currently blocked on or on the run queue of.
+ *
* -------------------------------------------------------------------------- */
-void
-deleteThread(StgTSO *tso)
+void
+raiseAsync(Capability *cap, StgTSO *tso, StgClosure *exception)
{
- raiseAsync(tso,NULL);
+ raiseAsync_(cap, tso, exception, rtsFalse, NULL);
}
void
-raiseAsync(StgTSO *tso, StgClosure *exception)
+suspendComputation(Capability *cap, StgTSO *tso, StgPtr stop_here)
{
- StgUpdateFrame* su = tso->su;
- StgPtr sp = tso->sp;
-
- /* Thread already dead? */
- if (tso->what_next == ThreadComplete || tso->what_next == ThreadKilled) {
- return;
- }
-
- IF_DEBUG(scheduler, sched_belch("raising exception in thread %ld.", tso->id));
-
- /* Remove it from any blocking queues */
- unblockThread(tso);
-
- /* The stack freezing code assumes there's a closure pointer on
- * the top of the stack. This isn't always the case with compiled
- * code, so we have to push a dummy closure on the top which just
- * returns to the next return address on the stack.
- */
- if ( LOOKS_LIKE_GHC_INFO((void*)*sp) ) {
- *(--sp) = (W_)&stg_dummy_ret_closure;
- }
+ raiseAsync_(cap, tso, NULL, rtsFalse, stop_here);
+}
- while (1) {
- nat words = ((P_)su - (P_)sp) - 1;
+static void
+raiseAsync_(Capability *cap, StgTSO *tso, StgClosure *exception,
+ rtsBool stop_at_atomically, StgPtr stop_here)
+{
+ StgRetInfoTable *info;
+ StgPtr sp, frame;
nat i;
- StgAP_UPD * ap;
-
- /* If we find a CATCH_FRAME, and we've got an exception to raise,
- * then build the THUNK raise(exception), and leave it on
- * top of the CATCH_FRAME ready to enter.
- */
- if (get_itbl(su)->type == CATCH_FRAME && exception != NULL) {
- StgCatchFrame *cf = (StgCatchFrame *)su;
- StgClosure *raise;
-
- /* we've got an exception to raise, so let's pass it to the
- * handler in this frame.
- */
- raise = (StgClosure *)allocate(sizeofW(StgClosure)+1);
- TICK_ALLOC_SE_THK(1,0);
- SET_HDR(raise,&stg_raise_info,cf->header.prof.ccs);
- raise->payload[0] = exception;
-
- /* throw away the stack from Sp up to the CATCH_FRAME.
- */
- sp = (P_)su - 1;
-
- /* Ensure that async excpetions are blocked now, so we don't get
- * a surprise exception before we get around to executing the
- * handler.
- */
- if (tso->blocked_exceptions == NULL) {
- tso->blocked_exceptions = END_TSO_QUEUE;
- }
-
- /* Put the newly-built THUNK on top of the stack, ready to execute
- * when the thread restarts.
- */
- sp[0] = (W_)raise;
- tso->sp = sp;
- tso->su = su;
- tso->what_next = ThreadEnterGHC;
- IF_DEBUG(sanity, checkTSO(tso));
- return;
+
+ // Thread already dead?
+ if (tso->what_next == ThreadComplete || tso->what_next == ThreadKilled) {
+ return;
}
- /* First build an AP_UPD consisting of the stack chunk above the
- * current update frame, with the top word on the stack as the
- * fun field.
- */
- ap = (StgAP_UPD *)allocate(AP_sizeW(words));
+ IF_DEBUG(scheduler,
+ sched_belch("raising exception in thread %ld.", (long)tso->id));
- ASSERT(words >= 0);
+ // Remove it from any blocking queues
+ unblockThread(cap,tso);
+
+ // mark it dirty; we're about to change its stack.
+ dirtyTSO(tso);
+
+ sp = tso->sp;
- ap->n_args = words;
- ap->fun = (StgClosure *)sp[0];
- sp++;
- for(i=0; i < (nat)words; ++i) {
- ap->payload[i] = (StgClosure *)*sp++;
+ // The stack freezing code assumes there's a closure pointer on
+ // the top of the stack, so we have to arrange that this is the case...
+ //
+ if (sp[0] == (W_)&stg_enter_info) {
+ sp++;
+ } else {
+ sp--;
+ sp[0] = (W_)&stg_dummy_ret_closure;
}
-
- switch (get_itbl(su)->type) {
-
- case UPDATE_FRAME:
- {
- SET_HDR(ap,&stg_AP_UPD_info,su->header.prof.ccs /* ToDo */);
- TICK_ALLOC_UP_THK(words+1,0);
-
- IF_DEBUG(scheduler,
- fprintf(stderr, "scheduler: Updating ");
- printPtr((P_)su->updatee);
- fprintf(stderr, " with ");
- printObj((StgClosure *)ap);
- );
-
- /* Replace the updatee with an indirection - happily
- * this will also wake up any threads currently
- * waiting on the result.
- *
- * Warning: if we're in a loop, more than one update frame on
- * the stack may point to the same object. Be careful not to
- * overwrite an IND_OLDGEN in this case, because we'll screw
- * up the mutable lists. To be on the safe side, don't
- * overwrite any kind of indirection at all. See also
- * threadSqueezeStack in GC.c, where we have to make a similar
- * check.
- */
- if (!closure_IND(su->updatee)) {
- UPD_IND_NOLOCK(su->updatee,ap); /* revert the black hole */
+
+ frame = sp + 1;
+ while (stop_here == NULL || frame < stop_here) {
+
+ // 1. Let the top of the stack be the "current closure"
+ //
+ // 2. Walk up the stack until we find either an UPDATE_FRAME or a
+ // CATCH_FRAME.
+ //
+ // 3. If it's an UPDATE_FRAME, then make an AP_STACK containing the
+ // current closure applied to the chunk of stack up to (but not
+ // including) the update frame. This closure becomes the "current
+ // closure". Go back to step 2.
+ //
+ // 4. If it's a CATCH_FRAME, then leave the exception handler on
+ // top of the stack applied to the exception.
+ //
+ // 5. If it's a STOP_FRAME, then kill the thread.
+ //
+ // NB: if we pass an ATOMICALLY_FRAME then abort the associated
+ // transaction
+
+ info = get_ret_itbl((StgClosure *)frame);
+
+ switch (info->i.type) {
+
+ case UPDATE_FRAME:
+ {
+ StgAP_STACK * ap;
+ nat words;
+
+ // First build an AP_STACK consisting of the stack chunk above the
+ // current update frame, with the top word on the stack as the
+ // fun field.
+ //
+ words = frame - sp - 1;
+ ap = (StgAP_STACK *)allocateLocal(cap,AP_STACK_sizeW(words));
+
+ ap->size = words;
+ ap->fun = (StgClosure *)sp[0];
+ sp++;
+ for(i=0; i < (nat)words; ++i) {
+ ap->payload[i] = (StgClosure *)*sp++;
+ }
+
+ SET_HDR(ap,&stg_AP_STACK_info,
+ ((StgClosure *)frame)->header.prof.ccs /* ToDo */);
+ TICK_ALLOC_UP_THK(words+1,0);
+
+ IF_DEBUG(scheduler,
+ debugBelch("sched: Updating ");
+ printPtr((P_)((StgUpdateFrame *)frame)->updatee);
+ debugBelch(" with ");
+ printObj((StgClosure *)ap);
+ );
+
+ // Replace the updatee with an indirection
+ //
+ // Warning: if we're in a loop, more than one update frame on
+ // the stack may point to the same object. Be careful not to
+ // overwrite an IND_OLDGEN in this case, because we'll screw
+ // up the mutable lists. To be on the safe side, don't
+ // overwrite any kind of indirection at all. See also
+ // threadSqueezeStack in GC.c, where we have to make a similar
+ // check.
+ //
+ if (!closure_IND(((StgUpdateFrame *)frame)->updatee)) {
+ // revert the black hole
+ UPD_IND_NOLOCK(((StgUpdateFrame *)frame)->updatee,
+ (StgClosure *)ap);
+ }
+ sp += sizeofW(StgUpdateFrame) - 1;
+ sp[0] = (W_)ap; // push onto stack
+ frame = sp + 1;
+ continue; //no need to bump frame
}
- su = su->link;
- sp += sizeofW(StgUpdateFrame) -1;
- sp[0] = (W_)ap; /* push onto stack */
- break;
- }
- case CATCH_FRAME:
- {
- StgCatchFrame *cf = (StgCatchFrame *)su;
- StgClosure* o;
-
- /* We want a PAP, not an AP_UPD. Fortunately, the
- * layout's the same.
- */
- SET_HDR(ap,&stg_PAP_info,su->header.prof.ccs /* ToDo */);
- TICK_ALLOC_UPD_PAP(words+1,0);
-
- /* now build o = FUN(catch,ap,handler) */
- o = (StgClosure *)allocate(sizeofW(StgClosure)+2);
- TICK_ALLOC_FUN(2,0);
- SET_HDR(o,&stg_catch_info,su->header.prof.ccs /* ToDo */);
- o->payload[0] = (StgClosure *)ap;
- o->payload[1] = cf->handler;
-
- IF_DEBUG(scheduler,
- fprintf(stderr, "scheduler: Built ");
- printObj((StgClosure *)o);
- );
-
- /* pop the old handler and put o on the stack */
- su = cf->link;
- sp += sizeofW(StgCatchFrame) - 1;
- sp[0] = (W_)o;
- break;
- }
-
- case SEQ_FRAME:
- {
- StgSeqFrame *sf = (StgSeqFrame *)su;
- StgClosure* o;
-
- SET_HDR(ap,&stg_PAP_info,su->header.prof.ccs /* ToDo */);
- TICK_ALLOC_UPD_PAP(words+1,0);
-
- /* now build o = FUN(seq,ap) */
- o = (StgClosure *)allocate(sizeofW(StgClosure)+1);
- TICK_ALLOC_SE_THK(1,0);
- SET_HDR(o,&stg_seq_info,su->header.prof.ccs /* ToDo */);
- o->payload[0] = (StgClosure *)ap;
-
- IF_DEBUG(scheduler,
- fprintf(stderr, "scheduler: Built ");
- printObj((StgClosure *)o);
- );
-
- /* pop the old handler and put o on the stack */
- su = sf->link;
- sp += sizeofW(StgSeqFrame) - 1;
- sp[0] = (W_)o;
- break;
- }
-
- case STOP_FRAME:
- /* We've stripped the entire stack, the thread is now dead. */
- sp += sizeofW(StgStopFrame) - 1;
- sp[0] = (W_)exception; /* save the exception */
- tso->what_next = ThreadKilled;
- tso->su = (StgUpdateFrame *)(sp+1);
- tso->sp = sp;
- return;
+ case STOP_FRAME:
+ // We've stripped the entire stack, the thread is now dead.
+ tso->what_next = ThreadKilled;
+ tso->sp = frame + sizeofW(StgStopFrame);
+ return;
+
+ case CATCH_FRAME:
+ // If we find a CATCH_FRAME, and we've got an exception to raise,
+ // then build the THUNK raise(exception), and leave it on
+ // top of the CATCH_FRAME ready to enter.
+ //
+ {
+#ifdef PROFILING
+ StgCatchFrame *cf = (StgCatchFrame *)frame;
+#endif
+ StgThunk *raise;
+
+ if (exception == NULL) break;
+
+ // we've got an exception to raise, so let's pass it to the
+ // handler in this frame.
+ //
+ raise = (StgThunk *)allocateLocal(cap,sizeofW(StgThunk)+1);
+ TICK_ALLOC_SE_THK(1,0);
+ SET_HDR(raise,&stg_raise_info,cf->header.prof.ccs);
+ raise->payload[0] = exception;
+
+ // throw away the stack from Sp up to the CATCH_FRAME.
+ //
+ sp = frame - 1;
+
+ /* Ensure that async excpetions are blocked now, so we don't get
+ * a surprise exception before we get around to executing the
+ * handler.
+ */
+ if (tso->blocked_exceptions == NULL) {
+ tso->blocked_exceptions = END_TSO_QUEUE;
+ }
- default:
- barf("raiseAsync");
+ /* Put the newly-built THUNK on top of the stack, ready to execute
+ * when the thread restarts.
+ */
+ sp[0] = (W_)raise;
+ sp[-1] = (W_)&stg_enter_info;
+ tso->sp = sp-1;
+ tso->what_next = ThreadRunGHC;
+ IF_DEBUG(sanity, checkTSO(tso));
+ return;
+ }
+
+ case ATOMICALLY_FRAME:
+ if (stop_at_atomically) {
+ ASSERT(stmGetEnclosingTRec(tso->trec) == NO_TREC);
+ stmCondemnTransaction(cap, tso -> trec);
+#ifdef REG_R1
+ tso->sp = frame;
+#else
+ // R1 is not a register: the return convention for IO in
+ // this case puts the return value on the stack, so we
+ // need to set up the stack to return to the atomically
+ // frame properly...
+ tso->sp = frame - 2;
+ tso->sp[1] = (StgWord) &stg_NO_FINALIZER_closure; // why not?
+ tso->sp[0] = (StgWord) &stg_ut_1_0_unreg_info;
+#endif
+ tso->what_next = ThreadRunGHC;
+ return;
+ }
+ // Not stop_at_atomically... fall through and abort the
+ // transaction.
+
+ case CATCH_RETRY_FRAME:
+ // IF we find an ATOMICALLY_FRAME then we abort the
+ // current transaction and propagate the exception. In
+ // this case (unlike ordinary exceptions) we do not care
+ // whether the transaction is valid or not because its
+ // possible validity cannot have caused the exception
+ // and will not be visible after the abort.
+ IF_DEBUG(stm,
+ debugBelch("Found atomically block delivering async exception\n"));
+ StgTRecHeader *trec = tso -> trec;
+ StgTRecHeader *outer = stmGetEnclosingTRec(trec);
+ stmAbortTransaction(cap, trec);
+ tso -> trec = outer;
+ break;
+
+ default:
+ break;
+ }
+
+ // move on to the next stack frame
+ frame += stack_frame_sizeW((StgClosure *)frame);
}
- }
- barf("raiseAsync");
+
+ // if we got here, then we stopped at stop_here
+ ASSERT(stop_here != NULL);
}
/* -----------------------------------------------------------------------------
- resurrectThreads is called after garbage collection on the list of
- threads found to be garbage. Each of these threads will be woken
- up and sent a signal: BlockedOnDeadMVar if the thread was blocked
- on an MVar, or NonTermination if the thread was blocked on a Black
- Hole.
+ Deleting threads
+
+ This is used for interruption (^C) and forking, and corresponds to
+ raising an exception but without letting the thread catch the
+ exception.
-------------------------------------------------------------------------- */
-void
-resurrectThreads( StgTSO *threads )
+static void
+deleteThread (Capability *cap, StgTSO *tso)
{
- StgTSO *tso, *next;
+ if (tso->why_blocked != BlockedOnCCall &&
+ tso->why_blocked != BlockedOnCCall_NoUnblockExc) {
+ raiseAsync(cap,tso,NULL);
+ }
+}
- for (tso = threads; tso != END_TSO_QUEUE; tso = next) {
- next = tso->global_link;
- tso->global_link = all_threads;
- all_threads = tso;
- IF_DEBUG(scheduler, sched_belch("resurrecting thread %d", tso->id));
+#ifdef FORKPROCESS_PRIMOP_SUPPORTED
+static void
+deleteThread_(Capability *cap, StgTSO *tso)
+{ // for forkProcess only:
+ // like deleteThread(), but we delete threads in foreign calls, too.
- switch (tso->why_blocked) {
- case BlockedOnMVar:
- case BlockedOnException:
- raiseAsync(tso,(StgClosure *)BlockedOnDeadMVar_closure);
- break;
- case BlockedOnBlackHole:
- raiseAsync(tso,(StgClosure *)NonTermination_closure);
- break;
- case NotBlocked:
- /* This might happen if the thread was blocked on a black hole
- * belonging to a thread that we've just woken up (raiseAsync
- * can wake up threads, remember...).
- */
- continue;
- default:
- barf("resurrectThreads: thread blocked in a strange way");
+ if (tso->why_blocked == BlockedOnCCall ||
+ tso->why_blocked == BlockedOnCCall_NoUnblockExc) {
+ unblockOne(cap,tso);
+ tso->what_next = ThreadKilled;
+ } else {
+ deleteThread(cap,tso);
}
- }
}
+#endif
/* -----------------------------------------------------------------------------
- * Blackhole detection: if we reach a deadlock, test whether any
- * threads are blocked on themselves. Any threads which are found to
- * be self-blocked get sent a NonTermination exception.
- *
- * This is only done in a deadlock situation in order to avoid
- * performance overhead in the normal case.
- * -------------------------------------------------------------------------- */
+ raiseExceptionHelper
+
+ This function is called by the raise# primitve, just so that we can
+ move some of the tricky bits of raising an exception from C-- into
+ C. Who knows, it might be a useful re-useable thing here too.
+ -------------------------------------------------------------------------- */
-static void
-detectBlackHoles( void )
+StgWord
+raiseExceptionHelper (StgRegTable *reg, StgTSO *tso, StgClosure *exception)
{
- StgTSO *t = all_threads;
- StgUpdateFrame *frame;
- StgClosure *blocked_on;
-
- for (t = all_threads; t != END_TSO_QUEUE; t = t->global_link) {
+ Capability *cap = regTableToCapability(reg);
+ StgThunk *raise_closure = NULL;
+ StgPtr p, next;
+ StgRetInfoTable *info;
+ //
+ // This closure represents the expression 'raise# E' where E
+ // is the exception raise. It is used to overwrite all the
+ // thunks which are currently under evaluataion.
+ //
+
+ // OLD COMMENT (we don't have MIN_UPD_SIZE now):
+ // LDV profiling: stg_raise_info has THUNK as its closure
+ // type. Since a THUNK takes at least MIN_UPD_SIZE words in its
+ // payload, MIN_UPD_SIZE is more approprate than 1. It seems that
+ // 1 does not cause any problem unless profiling is performed.
+ // However, when LDV profiling goes on, we need to linearly scan
+ // small object pool, where raise_closure is stored, so we should
+ // use MIN_UPD_SIZE.
+ //
+ // raise_closure = (StgClosure *)RET_STGCALL1(P_,allocate,
+ // sizeofW(StgClosure)+1);
+ //
+
+ //
+ // Walk up the stack, looking for the catch frame. On the way,
+ // we update any closures pointed to from update frames with the
+ // raise closure that we just built.
+ //
+ p = tso->sp;
+ while(1) {
+ info = get_ret_itbl((StgClosure *)p);
+ next = p + stack_frame_sizeW((StgClosure *)p);
+ switch (info->i.type) {
+
+ case UPDATE_FRAME:
+ // Only create raise_closure if we need to.
+ if (raise_closure == NULL) {
+ raise_closure =
+ (StgThunk *)allocateLocal(cap,sizeofW(StgThunk)+1);
+ SET_HDR(raise_closure, &stg_raise_info, CCCS);
+ raise_closure->payload[0] = exception;
+ }
+ UPD_IND(((StgUpdateFrame *)p)->updatee,(StgClosure *)raise_closure);
+ p = next;
+ continue;
- while (t->what_next == ThreadRelocated) {
- t = t->link;
- ASSERT(get_itbl(t)->type == TSO);
- }
-
- if (t->why_blocked != BlockedOnBlackHole) {
+ case ATOMICALLY_FRAME:
+ IF_DEBUG(stm, debugBelch("Found ATOMICALLY_FRAME at %p\n", p));
+ tso->sp = p;
+ return ATOMICALLY_FRAME;
+
+ case CATCH_FRAME:
+ tso->sp = p;
+ return CATCH_FRAME;
+
+ case CATCH_STM_FRAME:
+ IF_DEBUG(stm, debugBelch("Found CATCH_STM_FRAME at %p\n", p));
+ tso->sp = p;
+ return CATCH_STM_FRAME;
+
+ case STOP_FRAME:
+ tso->sp = p;
+ return STOP_FRAME;
+
+ case CATCH_RETRY_FRAME:
+ default:
+ p = next;
continue;
}
+ }
+}
- blocked_on = t->block_info.closure;
- for (frame = t->su; ; frame = frame->link) {
- switch (get_itbl(frame)->type) {
+/* -----------------------------------------------------------------------------
+ findRetryFrameHelper
- case UPDATE_FRAME:
- if (frame->updatee == blocked_on) {
- /* We are blocking on one of our own computations, so
- * send this thread the NonTermination exception.
- */
- IF_DEBUG(scheduler,
- sched_belch("thread %d is blocked on itself", t->id));
- raiseAsync(t, (StgClosure *)NonTermination_closure);
- goto done;
- }
- else {
- continue;
- }
+ This function is called by the retry# primitive. It traverses the stack
+ leaving tso->sp referring to the frame which should handle the retry.
- case CATCH_FRAME:
- case SEQ_FRAME:
- continue;
-
- case STOP_FRAME:
- break;
- }
- break;
- }
+ This should either be a CATCH_RETRY_FRAME (if the retry# is within an orElse#)
+ or should be a ATOMICALLY_FRAME (if the retry# reaches the top level).
- done: ;
- }
-}
+ We skip CATCH_STM_FRAMEs because retries are not considered to be exceptions,
+ despite the similar implementation.
+
+ We should not expect to see CATCH_FRAME or STOP_FRAME because those should
+ not be created within memory transactions.
+ -------------------------------------------------------------------------- */
+
+StgWord
+findRetryFrameHelper (StgTSO *tso)
+{
+ StgPtr p, next;
+ StgRetInfoTable *info;
-//@node Debugging Routines, Index, Exception Handling Routines, Main scheduling code
-//@subsection Debugging Routines
+ p = tso -> sp;
+ while (1) {
+ info = get_ret_itbl((StgClosure *)p);
+ next = p + stack_frame_sizeW((StgClosure *)p);
+ switch (info->i.type) {
+
+ case ATOMICALLY_FRAME:
+ IF_DEBUG(stm, debugBelch("Found ATOMICALLY_FRAME at %p during retrry\n", p));
+ tso->sp = p;
+ return ATOMICALLY_FRAME;
+
+ case CATCH_RETRY_FRAME:
+ IF_DEBUG(stm, debugBelch("Found CATCH_RETRY_FRAME at %p during retrry\n", p));
+ tso->sp = p;
+ return CATCH_RETRY_FRAME;
+
+ case CATCH_STM_FRAME:
+ default:
+ ASSERT(info->i.type != CATCH_FRAME);
+ ASSERT(info->i.type != STOP_FRAME);
+ p = next;
+ continue;
+ }
+ }
+}
/* -----------------------------------------------------------------------------
- Debugging: why is a thread blocked
- -------------------------------------------------------------------------- */
+ resurrectThreads is called after garbage collection on the list of
+ threads found to be garbage. Each of these threads will be woken
+ up and sent a signal: BlockedOnDeadMVar if the thread was blocked
+ on an MVar, or NonTermination if the thread was blocked on a Black
+ Hole.
-#ifdef DEBUG
+ Locks: assumes we hold *all* the capabilities.
+ -------------------------------------------------------------------------- */
void
+resurrectThreads (StgTSO *threads)
+{
+ StgTSO *tso, *next;
+ Capability *cap;
+
+ for (tso = threads; tso != END_TSO_QUEUE; tso = next) {
+ next = tso->global_link;
+ tso->global_link = all_threads;
+ all_threads = tso;
+ IF_DEBUG(scheduler, sched_belch("resurrecting thread %d", tso->id));
+
+ // Wake up the thread on the Capability it was last on for a
+ // bound thread, or last_free_capability otherwise.
+ if (tso->bound) {
+ cap = tso->bound->cap;
+ } else {
+ cap = last_free_capability;
+ }
+
+ switch (tso->why_blocked) {
+ case BlockedOnMVar:
+ case BlockedOnException:
+ /* Called by GC - sched_mutex lock is currently held. */
+ raiseAsync(cap, tso,(StgClosure *)BlockedOnDeadMVar_closure);
+ break;
+ case BlockedOnBlackHole:
+ raiseAsync(cap, tso,(StgClosure *)NonTermination_closure);
+ break;
+ case BlockedOnSTM:
+ raiseAsync(cap, tso,(StgClosure *)BlockedIndefinitely_closure);
+ break;
+ case NotBlocked:
+ /* This might happen if the thread was blocked on a black hole
+ * belonging to a thread that we've just woken up (raiseAsync
+ * can wake up threads, remember...).
+ */
+ continue;
+ default:
+ barf("resurrectThreads: thread blocked in a strange way");
+ }
+ }
+}
+
+/* ----------------------------------------------------------------------------
+ * Debugging: why is a thread blocked
+ * [Also provides useful information when debugging threaded programs
+ * at the Haskell source code level, so enable outside of DEBUG. --sof 7/02]
+ ------------------------------------------------------------------------- */
+
+#if DEBUG
+static void
printThreadBlockage(StgTSO *tso)
{
switch (tso->why_blocked) {
case BlockedOnRead:
- fprintf(stderr,"is blocked on read from fd %d", tso->block_info.fd);
+ debugBelch("is blocked on read from fd %d", (int)(tso->block_info.fd));
break;
case BlockedOnWrite:
- fprintf(stderr,"is blocked on write to fd %d", tso->block_info.fd);
+ debugBelch("is blocked on write to fd %d", (int)(tso->block_info.fd));
+ break;
+#if defined(mingw32_HOST_OS)
+ case BlockedOnDoProc:
+ debugBelch("is blocked on proc (request: %ld)", tso->block_info.async_result->reqID);
break;
+#endif
case BlockedOnDelay:
- fprintf(stderr,"is blocked until %d", tso->block_info.target);
+ debugBelch("is blocked until %ld", (long)(tso->block_info.target));
break;
case BlockedOnMVar:
- fprintf(stderr,"is blocked on an MVar");
+ debugBelch("is blocked on an MVar @ %p", tso->block_info.closure);
break;
case BlockedOnException:
- fprintf(stderr,"is blocked on delivering an exception to thread %d",
+ debugBelch("is blocked on delivering an exception to thread %d",
tso->block_info.tso->id);
break;
case BlockedOnBlackHole:
- fprintf(stderr,"is blocked on a black hole");
+ debugBelch("is blocked on a black hole");
break;
case NotBlocked:
- fprintf(stderr,"is not blocked");
+ debugBelch("is not blocked");
break;
-#if defined(PAR)
+#if defined(PARALLEL_HASKELL)
case BlockedOnGA:
- fprintf(stderr,"is blocked on global address; local FM_BQ is %p (%s)",
+ debugBelch("is blocked on global address; local FM_BQ is %p (%s)",
tso->block_info.closure, info_type(tso->block_info.closure));
break;
case BlockedOnGA_NoSend:
- fprintf(stderr,"is blocked on global address (no send); local FM_BQ is %p (%s)",
+ debugBelch("is blocked on global address (no send); local FM_BQ is %p (%s)",
tso->block_info.closure, info_type(tso->block_info.closure));
break;
#endif
-#if defined(RTS_SUPPORTS_THREADS)
case BlockedOnCCall:
- fprintf(stderr,"is blocked on an external call");
+ debugBelch("is blocked on an external call");
+ break;
+ case BlockedOnCCall_NoUnblockExc:
+ debugBelch("is blocked on an external call (exceptions were already blocked)");
+ break;
+ case BlockedOnSTM:
+ debugBelch("is blocked on an STM operation");
break;
-#endif
default:
barf("printThreadBlockage: strange tso->why_blocked: %d for TSO %d (%d)",
tso->why_blocked, tso->id, tso);
}
void
-printThreadStatus(StgTSO *tso)
+printThreadStatus(StgTSO *t)
{
- switch (tso->what_next) {
- case ThreadKilled:
- fprintf(stderr,"has been killed");
- break;
- case ThreadComplete:
- fprintf(stderr,"has completed");
- break;
- default:
- printThreadBlockage(tso);
- }
+ debugBelch("\tthread %4d @ %p ", t->id, (void *)t);
+ {
+ void *label = lookupThreadLabel(t->id);
+ if (label) debugBelch("[\"%s\"] ",(char *)label);
+ }
+ if (t->what_next == ThreadRelocated) {
+ debugBelch("has been relocated...\n");
+ } else {
+ switch (t->what_next) {
+ case ThreadKilled:
+ debugBelch("has been killed");
+ break;
+ case ThreadComplete:
+ debugBelch("has completed");
+ break;
+ default:
+ printThreadBlockage(t);
+ }
+ debugBelch("\n");
+ }
}
void
printAllThreads(void)
{
- StgTSO *t;
+ StgTSO *t, *next;
+ nat i;
+ Capability *cap;
# if defined(GRAN)
char time_string[TIME_STR_LEN], node_str[NODE_STR_LEN];
ullong_format_string(TIME_ON_PROC(CurrentProc),
time_string, rtsFalse/*no commas!*/);
- sched_belch("all threads at [%s]:", time_string);
-# elif defined(PAR)
+ debugBelch("all threads at [%s]:\n", time_string);
+# elif defined(PARALLEL_HASKELL)
char time_string[TIME_STR_LEN], node_str[NODE_STR_LEN];
ullong_format_string(CURRENT_TIME,
time_string, rtsFalse/*no commas!*/);
- sched_belch("all threads at [%s]:", time_string);
+ debugBelch("all threads at [%s]:\n", time_string);
# else
- sched_belch("all threads:");
+ debugBelch("all threads:\n");
# endif
- for (t = all_threads; t != END_TSO_QUEUE; t = t->global_link) {
- fprintf(stderr, "\tthread %d ", t->id);
- printThreadStatus(t);
- fprintf(stderr,"\n");
+ for (i = 0; i < n_capabilities; i++) {
+ cap = &capabilities[i];
+ debugBelch("threads on capability %d:\n", cap->no);
+ for (t = cap->run_queue_hd; t != END_TSO_QUEUE; t = t->link) {
+ printThreadStatus(t);
+ }
+ }
+
+ debugBelch("other threads:\n");
+ for (t = all_threads; t != END_TSO_QUEUE; t = next) {
+ if (t->why_blocked != NotBlocked) {
+ printThreadStatus(t);
+ }
+ if (t->what_next == ThreadRelocated) {
+ next = t->link;
+ } else {
+ next = t->global_link;
+ }
}
}
-
+
+// useful from gdb
+void
+printThreadQueue(StgTSO *t)
+{
+ nat i = 0;
+ for (; t != END_TSO_QUEUE; t = t->link) {
+ printThreadStatus(t);
+ i++;
+ }
+ debugBelch("%d threads on queue\n", i);
+}
+
/*
Print a whole blocking queue attached to node (debugging only).
*/
-//@cindex print_bq
-# if defined(PAR)
+# if defined(PARALLEL_HASKELL)
void
print_bq (StgClosure *node)
{
StgTSO *tso;
rtsBool end;
- fprintf(stderr,"## BQ of closure %p (%s): ",
+ debugBelch("## BQ of closure %p (%s): ",
node, info_type(node));
/* should cover all closures that may have a blocking queue */
switch (get_itbl(bqe)->type) {
case TSO:
- fprintf(stderr," TSO %u (%x),",
+ debugBelch(" TSO %u (%x),",
((StgTSO *)bqe)->id, ((StgTSO *)bqe));
break;
case BLOCKED_FETCH:
- fprintf(stderr," BF (node=%p, ga=((%x, %d, %x)),",
+ debugBelch(" BF (node=%p, ga=((%x, %d, %x)),",
((StgBlockedFetch *)bqe)->node,
((StgBlockedFetch *)bqe)->ga.payload.gc.gtid,
((StgBlockedFetch *)bqe)->ga.payload.gc.slot,
((StgBlockedFetch *)bqe)->ga.weight);
break;
case CONSTR:
- fprintf(stderr," %s (IP %p),",
+ debugBelch(" %s (IP %p),",
(get_itbl(bqe) == &stg_RBH_Save_0_info ? "RBH_Save_0" :
get_itbl(bqe) == &stg_RBH_Save_1_info ? "RBH_Save_1" :
get_itbl(bqe) == &stg_RBH_Save_2_info ? "RBH_Save_2" :
break;
}
} /* for */
- fputc('\n', stderr);
+ debugBelch("\n");
}
# elif defined(GRAN)
void
ASSERT(node!=(StgClosure*)NULL); // sanity check
node_loc = where_is(node);
- fprintf(stderr,"## BQ of closure %p (%s) on [PE %d]: ",
+ debugBelch("## BQ of closure %p (%s) on [PE %d]: ",
node, info_type(node), node_loc);
/*
tso_loc = where_is((StgClosure *)bqe);
switch (get_itbl(bqe)->type) {
case TSO:
- fprintf(stderr," TSO %d (%p) on [PE %d],",
+ debugBelch(" TSO %d (%p) on [PE %d],",
((StgTSO *)bqe)->id, (StgTSO *)bqe, tso_loc);
break;
case CONSTR:
- fprintf(stderr," %s (IP %p),",
+ debugBelch(" %s (IP %p),",
(get_itbl(bqe) == &stg_RBH_Save_0_info ? "RBH_Save_0" :
get_itbl(bqe) == &stg_RBH_Save_1_info ? "RBH_Save_1" :
get_itbl(bqe) == &stg_RBH_Save_2_info ? "RBH_Save_2" :
break;
}
} /* for */
- fputc('\n', stderr);
-}
-#else
-/*
- Nice and easy: only TSOs on the blocking queue
-*/
-void
-print_bq (StgClosure *node)
-{
- StgTSO *tso;
-
- ASSERT(node!=(StgClosure*)NULL); // sanity check
- for (tso = ((StgBlockingQueue*)node)->blocking_queue;
- tso != END_TSO_QUEUE;
- tso=tso->link) {
- ASSERT(tso!=NULL && tso!=END_TSO_QUEUE); // sanity check
- ASSERT(get_itbl(tso)->type == TSO); // guess what, sanity check
- fprintf(stderr," TSO %d (%p),", tso->id, tso);
- }
- fputc('\n', stderr);
+ debugBelch("\n");
}
# endif
-#if defined(PAR)
+#if defined(PARALLEL_HASKELL)
static nat
run_queue_len(void)
{
- nat i;
- StgTSO *tso;
-
- for (i=0, tso=run_queue_hd;
- tso != END_TSO_QUEUE;
- i++, tso=tso->link)
- /* nothing */
-
- return i;
+ nat i;
+ StgTSO *tso;
+
+ for (i=0, tso=run_queue_hd;
+ tso != END_TSO_QUEUE;
+ i++, tso=tso->link) {
+ /* nothing */
+ }
+
+ return i;
}
#endif
-static void
+void
sched_belch(char *s, ...)
{
- va_list ap;
- va_start(ap,s);
-#ifdef SMP
- fprintf(stderr, "scheduler (task %ld): ", osThreadId());
-#elif defined(PAR)
- fprintf(stderr, "== ");
+ va_list ap;
+ va_start(ap,s);
+#ifdef THREADED_RTS
+ debugBelch("sched (task %p): ", (void *)(unsigned long)(unsigned int)osThreadId());
+#elif defined(PARALLEL_HASKELL)
+ debugBelch("== ");
#else
- fprintf(stderr, "scheduler: ");
+ debugBelch("sched: ");
#endif
- vfprintf(stderr, s, ap);
- fprintf(stderr, "\n");
+ vdebugBelch(s, ap);
+ debugBelch("\n");
+ va_end(ap);
}
#endif /* DEBUG */
-
-
-//@node Index, , Debugging Routines, Main scheduling code
-//@subsection Index
-
-//@index
-//* StgMainThread:: @cindex\s-+StgMainThread
-//* awaken_blocked_queue:: @cindex\s-+awaken_blocked_queue
-//* blocked_queue_hd:: @cindex\s-+blocked_queue_hd
-//* blocked_queue_tl:: @cindex\s-+blocked_queue_tl
-//* context_switch:: @cindex\s-+context_switch
-//* createThread:: @cindex\s-+createThread
-//* gc_pending_cond:: @cindex\s-+gc_pending_cond
-//* initScheduler:: @cindex\s-+initScheduler
-//* interrupted:: @cindex\s-+interrupted
-//* next_thread_id:: @cindex\s-+next_thread_id
-//* print_bq:: @cindex\s-+print_bq
-//* run_queue_hd:: @cindex\s-+run_queue_hd
-//* run_queue_tl:: @cindex\s-+run_queue_tl
-//* sched_mutex:: @cindex\s-+sched_mutex
-//* schedule:: @cindex\s-+schedule
-//* take_off_run_queue:: @cindex\s-+take_off_run_queue
-//* term_mutex:: @cindex\s-+term_mutex
-//@end index
projects / ghc-hetmet.git / blobdiff