/* ---------------------------------------------------------------------------
- * $Id: Schedule.c,v 1.168 2003/04/08 15:53:51 sof Exp $
*
- * (c) The GHC Team, 1998-2000
+ * (c) The GHC Team, 1998-2004
*
* Scheduler
*
*
* WAY Name CPP flag What's it for
* --------------------------------------
- * mp GUM PAR Parallel execution on a distributed memory machine
+ * mp GUM PARALLEL_HASKELL Parallel execution on a distrib. 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)
*
* --------------------------------------------------------------------------*/
-//@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.
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"
#define COMPILING_SCHEDULER
#include "Schedule.h"
#include "StgMiscClosures.h"
-#include "Storage.h"
#include "Interpreter.h"
#include "Exception.h"
#include "Printer.h"
#include "Signals.h"
#include "Sanity.h"
#include "Stats.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"
#ifdef HAVE_SYS_TYPES_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 = NULL;
+// Turn off inlining when debugging - it obfuscates things
+#ifdef DEBUG
+# undef STATIC_INLINE
+# define STATIC_INLINE static
+#endif
#ifdef THREADED_RTS
-// Pointer to the thread that executes main
-// When this thread is finished, the program terminates
-// by calling shutdownHaskellAndExit.
-// It would be better to add a call to shutdownHaskellAndExit
-// to the Main.main wrapper and to remove this hack.
-StgMainThread *main_main_thread = NULL;
+#define USED_IN_THREADED_RTS
+#else
+#define USED_IN_THREADED_RTS STG_UNUSED
#endif
-/* Thread queues.
+#ifdef RTS_SUPPORTS_THREADS
+#define USED_WHEN_RTS_SUPPORTS_THREADS
+#else
+#define USED_WHEN_RTS_SUPPORTS_THREADS STG_UNUSED
+#endif
+
+/* Main thread queue.
* Locks required: sched_mutex.
*/
+StgMainThread *main_threads = NULL;
+
#if defined(GRAN)
StgTSO* ActiveTSO = NULL; /* for assigning system costs; GranSim-Light only */
#else /* !GRAN */
+/* Thread queues.
+ * Locks required: sched_mutex.
+ */
StgTSO *run_queue_hd = NULL;
StgTSO *run_queue_tl = NULL;
StgTSO *blocked_queue_hd = NULL;
StgTSO *blocked_queue_tl = NULL;
+StgTSO *blackhole_queue = NULL;
StgTSO *sleeping_queue = NULL; /* perhaps replace with a hash table? */
#endif
+/* The blackhole_queue should be checked for threads to wake up. See
+ * Schedule.h for more thorough comment.
+ */
+rtsBool blackholes_need_checking = rtsFalse;
+
/* Linked list of all threads.
* Used for detecting garbage collected threads.
*/
*/
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.
*/
/* flag set by signal handler to precipitate a context switch */
-//@cindex context_switch
-nat context_switch = 0;
+int context_switch = 0;
+
+/* flag that tracks whether we have done any execution in this time slice. */
+nat recent_activity = ACTIVITY_YES;
/* if this flag is set as well, give up execution */
-//@cindex interrupted
rtsBool interrupted = rtsFalse;
/* Next thread ID to allocate.
* Locks required: thread_id_mutex
*/
-//@cindex next_thread_id
static StgThreadID next_thread_id = 1;
/*
/* 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 dummy_tso;
-static rtsBool ready_to_gc;
-
/*
* 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
*/
static rtsBool shutting_down_scheduler = rtsFalse;
-void addToBlockedQueue ( StgTSO *tso );
-
-static void schedule ( void );
- void interruptStgRts ( void );
-
-static void detectBlackHoles ( void );
-
-#ifdef DEBUG
-static void sched_belch(char *s, ...);
-#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;
-/*
- * A heavyweight solution to the problem of protecting
- * the thread_id from concurrent update.
- */
-Mutex thread_id_mutex = INIT_MUTEX_VAR;
-
-
-# if defined(SMP)
-static Condition gc_pending_cond = INIT_COND_VAR;
-nat await_death;
-# endif
-
#endif /* RTS_SUPPORTS_THREADS */
-#if defined(PAR)
+#if defined(PARALLEL_HASKELL)
StgTSO *LastTSO;
rtsTime TimeOfLastYield;
rtsBool emitSchedule = rtsTrue;
#if DEBUG
static char *whatNext_strs[] = {
+ "(unknown)",
"ThreadRunGHC",
"ThreadInterpret",
"ThreadKilled",
};
#endif
-#if defined(PAR)
+/* -----------------------------------------------------------------------------
+ * static function prototypes
+ * -------------------------------------------------------------------------- */
+
+#if defined(RTS_SUPPORTS_THREADS)
+static void taskStart(void);
+#endif
+
+static void schedule( StgMainThread *mainThread USED_WHEN_RTS_SUPPORTS_THREADS,
+ Capability *initialCapability );
+
+//
+// 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);
+static void scheduleStartSignalHandlers(void);
+static void scheduleCheckBlockedThreads(void);
+static void scheduleCheckBlackHoles(void);
+static void scheduleDetectDeadlock(void);
+#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( StgTSO *t);
+static rtsBool scheduleHandleYield( StgTSO *t, nat prev_what_next );
+static void scheduleHandleThreadBlocked( StgTSO *t );
+static rtsBool scheduleHandleThreadFinished( StgMainThread *mainThread,
+ Capability *cap, StgTSO *t );
+static rtsBool scheduleDoHeapProfile(rtsBool ready_to_gc);
+static void scheduleDoGC(Capability *cap);
+
+static void unblockThread(StgTSO *tso);
+static rtsBool checkBlackHoles(void);
+static SchedulerStatus waitThread_(/*out*/StgMainThread* m,
+ Capability *initialCapability
+ );
+static void scheduleThread_ (StgTSO* tso);
+static void AllRoots(evac_fn evac);
+
+static StgTSO *threadStackOverflow(StgTSO *tso);
+
+static void raiseAsync_(StgTSO *tso, StgClosure *exception,
+ rtsBool stop_at_atomically);
+
+static void printThreadBlockage(StgTSO *tso);
+static void printThreadStatus(StgTSO *tso);
+
+#if defined(PARALLEL_HASKELL)
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;
- */
+/* ----------------------------------------------------------------------------
+ * Starting Tasks
+ * ------------------------------------------------------------------------- */
+
+#if defined(RTS_SUPPORTS_THREADS)
+static nat startingWorkerThread = 0;
-#if defined(PAR) || defined(RTS_SUPPORTS_THREADS)
-static void taskStart(void);
static void
taskStart(void)
{
- schedule();
+ ACQUIRE_LOCK(&sched_mutex);
+ startingWorkerThread--;
+ schedule(NULL,NULL);
+ taskStop();
+ RELEASE_LOCK(&sched_mutex);
}
-#endif
-#if defined(RTS_SUPPORTS_THREADS)
void
-startSchedulerTask(void)
+startSchedulerTaskIfNecessary(void)
{
- startTask(taskStart);
+ if ( !EMPTY_RUN_QUEUE()
+ && !shutting_down_scheduler // not if we're shutting down
+ && startingWorkerThread==0)
+ {
+ // we don't want to start another worker thread
+ // just because the last one hasn't yet reached the
+ // "waiting for capability" state
+ startingWorkerThread++;
+ if (!maybeStartNewWorker(taskStart)) {
+ startingWorkerThread--;
+ }
+ }
}
#endif
-//@node Main scheduling loop, Suspend and Resume, Prototypes, Main scheduling code
-//@subsection Main scheduling loop
+/* -----------------------------------------------------------------------------
+ * Putting a thread on the run queue: different scheduling policies
+ * -------------------------------------------------------------------------- */
+STATIC_INLINE void
+addToRunQueue( StgTSO *t )
+{
+#if defined(PARALLEL_HASKELL)
+ 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
+}
+
/* ---------------------------------------------------------------------------
Main scheduling loop.
This is not the ugliest code you could imagine, but it's bloody close.
------------------------------------------------------------------------ */
-//@cindex schedule
+
static void
-schedule( void )
+schedule( StgMainThread *mainThread USED_WHEN_RTS_SUPPORTS_THREADS,
+ Capability *initialCapability )
{
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;
- StgTSOWhatNext prev_what_next;
+ nat prev_what_next;
+ rtsBool ready_to_gc;
- ACQUIRE_LOCK(&sched_mutex);
-
-#if defined(RTS_SUPPORTS_THREADS)
- waitForWorkCapability(&sched_mutex, &cap, rtsFalse);
- IF_DEBUG(scheduler, sched_belch("worker thread (osthread %p): entering RTS", osThreadId()));
-#else
- /* simply initialise it in the non-threaded case */
+ // Pre-condition: sched_mutex is held.
+ // We might have a capability, passed in as initialCapability.
+ cap = initialCapability;
+
+#if !defined(RTS_SUPPORTS_THREADS)
+ // simply initialise it in the non-threaded case
grabCapability(&cap);
#endif
-#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];
- }
-
- event = get_next_event();
+ IF_DEBUG(scheduler,
+ sched_belch("### NEW SCHEDULER LOOP (main thr: %p, cap: %p)",
+ mainThread, 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
-
- while (1) {
-
+#define TERMINATION_CONDITION rtsTrue
#endif
- IF_DEBUG(scheduler, printAllThreads());
+ while (TERMINATION_CONDITION) {
-#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);
+#if defined(GRAN)
+ /* Choose the processor with the next event */
+ CurrentProc = event->proc;
+ CurrentTSO = event->tso;
#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"));
- interrupted = rtsFalse;
- was_interrupted = rtsTrue;
#if defined(RTS_SUPPORTS_THREADS)
- // In the threaded RTS, deadlock detection doesn't work,
- // so just exit right away.
- prog_belch("interrupted");
- releaseCapability(cap);
- startTask(taskStart); // thread-safe-call to shutdownHaskellAndExit
- RELEASE_LOCK(&sched_mutex);
- shutdownHaskellAndExit(EXIT_SUCCESS);
-#else
- deleteAllThreads();
-#endif
- }
+ // Yield the capability to higher-priority tasks if necessary.
+ //
+ if (cap != NULL) {
+ yieldCapability(&cap);
+ }
- /* 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; prev = &m->link, m = m->link) {
- switch (m->tso->what_next) {
- case ThreadComplete:
- if (m->ret) {
- // NOTE: return val is tso->sp[1] (see StgStartup.hc)
- *(m->ret) = (StgClosure *)m->tso->sp[1];
- }
- *prev = m->link;
- m->stat = Success;
- broadcastCondition(&m->wakeup);
-#ifdef DEBUG
- removeThreadLabel((StgWord)m->tso);
-#endif
- if(m == main_main_thread)
- {
- releaseCapability(cap);
- startTask(taskStart); // thread-safe-call to shutdownHaskellAndExit
- RELEASE_LOCK(&sched_mutex);
- shutdownHaskellAndExit(EXIT_SUCCESS);
- }
- break;
- case ThreadKilled:
- if (m->ret) *(m->ret) = NULL;
- *prev = m->link;
- if (was_interrupted) {
- m->stat = Interrupted;
- } else {
- m->stat = Killed;
+ // If we do not currently hold a capability, we wait for one
+ //
+ if (cap == NULL) {
+ waitForCapability(&sched_mutex, &cap,
+ mainThread ? &mainThread->bound_thread_cond : NULL);
+ }
+
+ // We now have a capability...
+#endif
+
+#if 0 /* extra sanity checking */
+ {
+ StgMainThread *m;
+ for (m = main_threads; m != NULL; m = m->link) {
+ ASSERT(get_itbl(m->tso)->type == TSO);
}
- broadcastCondition(&m->wakeup);
-#ifdef DEBUG
- removeThreadLabel((StgWord)m->tso);
-#endif
- if(m == main_main_thread)
- {
- releaseCapability(cap);
- startTask(taskStart); // thread-safe-call to shutdownHaskellAndExit
- RELEASE_LOCK(&sched_mutex);
- shutdownHaskellAndExit(EXIT_SUCCESS);
- }
- break;
- default:
- break;
- }
}
- }
+#endif
-#else /* not threaded */
+ // Check whether we have re-entered the RTS from Haskell without
+ // going via suspendThread()/resumeThread (i.e. a 'safe' foreign
+ // call).
+ if (cap->r.rInHaskell) {
+ errorBelch("schedule: re-entered unsafely.\n"
+ " Perhaps a 'foreign import unsafe' should be 'safe'?");
+ stg_exit(1);
+ }
-# 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.
- */
- {
- StgMainThread *m = main_threads;
- if (m->tso->what_next == ThreadComplete
- || m->tso->what_next == ThreadKilled) {
-#ifdef DEBUG
- removeThreadLabel((StgWord)m->tso);
-#endif
- main_threads = main_threads->link;
- if (m->tso->what_next == ThreadComplete) {
- // We finished successfully, fill in the return value
- // NOTE: return val is tso->sp[1] (see StgStartup.hc)
- if (m->ret) { *(m->ret) = (StgClosure *)m->tso->sp[1]; };
- m->stat = Success;
+ //
+ // Test for interruption. If interrupted==rtsTrue, then either
+ // we received a keyboard interrupt (^C), or the scheduler is
+ // trying to shut down all the tasks (shutting_down_scheduler) in
+ // the threaded RTS.
+ //
+ if (interrupted) {
+ if (shutting_down_scheduler) {
+ IF_DEBUG(scheduler, sched_belch("shutting down"));
+ releaseCapability(cap);
+ if (mainThread) {
+ mainThread->stat = Interrupted;
+ mainThread->ret = NULL;
+ }
return;
} else {
- if (m->ret) { *(m->ret) = NULL; };
- if (was_interrupted) {
- m->stat = Interrupted;
- } else {
- m->stat = Killed;
- }
- return;
+ IF_DEBUG(scheduler, sched_belch("interrupted"));
+ deleteAllThreads();
}
- }
}
-#endif
- /* 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) */
+#if defined(not_yet) && defined(SMP)
+ //
+ // 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.
+ //
{
- nat n = getFreeCapabilities();
- StgTSO *tso = run_queue_hd;
-
- /* Count the run queue */
- while (n > 0 && tso != END_TSO_QUEUE) {
- tso = tso->link;
- n--;
- }
-
- 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));
+ if (EMPTY_RUN_QUEUE()) {
+ spark = findSpark(rtsFalse);
+ if (spark == NULL) {
+ break; /* no more sparks in the pool */
+ } else {
+ 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
- /* check for signals each time around the scheduler */
-#if defined(RTS_USER_SIGNALS)
- if (signals_pending()) {
- RELEASE_LOCK(&sched_mutex); /* ToDo: kill */
- startSignalHandlers();
- ACQUIRE_LOCK(&sched_mutex);
- }
-#endif
+ scheduleStartSignalHandlers();
- /* 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 ( !EMPTY_QUEUE(blocked_queue_hd) || !EMPTY_QUEUE(sleeping_queue)
-#if defined(RTS_SUPPORTS_THREADS) && !defined(SMP)
- || EMPTY_RUN_QUEUE()
+ // 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 (EMPTY_RUN_QUEUE()) { scheduleCheckBlackHoles(); }
+
+ scheduleCheckBlockedThreads();
+
+ scheduleDetectDeadlock();
+
+ // 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 ( EMPTY_RUN_QUEUE() ) {
+#if !defined(RTS_SUPPORTS_THREADS) && !defined(mingw32_HOST_OS)
+ ASSERT(interrupted);
#endif
- )
- {
- awaitEvent( EMPTY_RUN_QUEUE()
-#if defined(SMP)
- && allFreeCapabilities()
+ continue; // nothing to do
+ }
+
+#if defined(PARALLEL_HASKELL)
+ scheduleSendPendingMessages();
+ if (EMPTY_RUN_QUEUE() && scheduleActivateSpark())
+ continue;
+
+#if defined(SPARKS)
+ ASSERT(next_fish_to_send_at==0); // i.e. no delayed fishes left!
#endif
- );
+
+ /* If we still have no work we need to send a FISH to get a spark
+ from another PE */
+ if (EMPTY_RUN_QUEUE()) {
+ 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();
}
- /* we can be interrupted while waiting for I/O... */
- if (interrupted) continue;
+#endif
- /*
- * 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.
- */
-#if !defined(PAR) && !defined(RTS_SUPPORTS_THREADS)
- if ( EMPTY_THREAD_QUEUES()
-#if defined(RTS_SUPPORTS_THREADS)
- && EMPTY_QUEUE(suspended_ccalling_threads)
+#if defined(GRAN)
+ scheduleProcessEvent(event);
#endif
-#ifdef SMP
- && allFreeCapabilities()
+
+ //
+ // Get a thread to run
+ //
+ ASSERT(run_queue_hd != END_TSO_QUEUE);
+ POP_RUN_QUEUE(t);
+
+#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
- )
+
+#if defined(RTS_SUPPORTS_THREADS)
+ // Check whether we can run this thread in the current task.
+ // If not, we have to pass our capability to the right task.
{
- IF_DEBUG(scheduler, sched_belch("deadlocked, forcing major GC..."));
-#if defined(THREADED_RTS)
- /* and SMP mode ..? */
- releaseCapability(cap);
+ StgMainThread *m = t->main;
+
+ if(m)
+ {
+ if(m == mainThread)
+ {
+ 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
+ PUSH_ON_RUN_QUEUE(t);
+ passCapability(&m->bound_thread_cond);
+ continue;
+ }
+ }
+ else
+ {
+ if(mainThread != NULL)
+ // The thread we want to run is bound.
+ {
+ 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
+ PUSH_ON_RUN_QUEUE(t);
+ passCapabilityToWorker();
+ continue;
+ }
+ }
+ }
#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; }
+ 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 ((RtsFlags.ConcFlags.ctxtSwitchTicks == 0
+ && (run_queue_hd != END_TSO_QUEUE
+ || blocked_queue_hd != END_TSO_QUEUE
+ || sleeping_queue != END_TSO_QUEUE)))
+ context_switch = 1;
- IF_DEBUG(scheduler,
- sched_belch("still deadlocked, checking for black holes..."));
- detectBlackHoles();
+run_thread:
- if ( !EMPTY_RUN_QUEUE() ) { goto not_deadlocked; }
+ RELEASE_LOCK(&sched_mutex);
-#if defined(RTS_USER_SIGNALS)
- /* If we have user-installed signal handlers, then wait
- * for signals to arrive rather then bombing out with a
- * deadlock.
- */
-#if defined(RTS_SUPPORTS_THREADS)
- if ( 0 ) { /* hmm..what to do? Simply stop waiting for
- a signal with no runnable threads (or I/O
- suspended ones) leads nowhere quick.
- For now, simply shut down when we reach this
- condition.
-
- ToDo: define precisely under what conditions
- the Scheduler should shut down in an MT setting.
- */
-#else
- if ( anyUserHandlers() ) {
+ IF_DEBUG(scheduler, sched_belch("-->> running thread %ld %s ...",
+ (long)t->id, whatNext_strs[t->what_next]));
+
+#if defined(PROFILING)
+ startHeapProfTimer();
#endif
- IF_DEBUG(scheduler,
- sched_belch("still deadlocked, waiting for signals..."));
- awaitUserSignals();
+ // ----------------------------------------------------------------------
+ // Run the current thread
- // we might be interrupted...
- if (interrupted) { continue; }
+ prev_what_next = t->what_next;
- if (signals_pending()) {
- RELEASE_LOCK(&sched_mutex);
+ errno = t->saved_errno;
+ cap->r.rInHaskell = rtsTrue;
+
+ recent_activity = ACTIVITY_YES;
+
+ switch (prev_what_next) {
+
+ case ThreadKilled:
+ case ThreadComplete:
+ /* Thread already finished, return to scheduler. */
+ ret = ThreadFinished;
+ break;
+
+ case ThreadRunGHC:
+ ret = StgRun((StgFunPtr) stg_returnToStackTop, &cap->r);
+ break;
+
+ case ThreadInterpret:
+ ret = interpretBCO(cap);
+ break;
+
+ default:
+ barf("schedule: invalid what_next field");
+ }
+
+#if defined(SMP)
+ // in SMP mode, we might return with a different capability than
+ // we started with, if the Haskell thread made a foreign call. So
+ // let's find out what our current Capability is:
+ cap = myCapability();
+#endif
+
+ // We have run some Haskell code: there might be blackhole-blocked
+ // threads to wake up now.
+ if ( blackhole_queue != END_TSO_QUEUE ) {
+ blackholes_need_checking = rtsTrue;
+ }
+
+ cap->r.rInHaskell = 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;
+
+ // And save the current errno in this thread.
+ t->saved_errno = errno;
+
+ // ----------------------------------------------------------------------
+
+ /* Costs for the scheduler are assigned to CCS_SYSTEM */
+#if defined(PROFILING)
+ stopHeapProfTimer();
+ CCCS = CCS_SYSTEM;
+#endif
+
+ ACQUIRE_LOCK(&sched_mutex);
+
+#if defined(RTS_SUPPORTS_THREADS)
+ IF_DEBUG(scheduler,debugBelch("sched (task %p): ", 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(t);
+ break;
+
+ case ThreadYielding:
+ if (scheduleHandleYield(t, prev_what_next)) {
+ // shortcut for switching between compiler/interpreter:
+ goto run_thread;
+ }
+ break;
+
+ case ThreadBlocked:
+ scheduleHandleThreadBlocked(t);
+ break;
+
+ case ThreadFinished:
+ if (scheduleHandleThreadFinished(mainThread, cap, t)) return;;
+ break;
+
+ default:
+ barf("schedule: invalid thread return code %d", (int)ret);
+ }
+
+ if (scheduleDoHeapProfile(ready_to_gc)) { ready_to_gc = rtsFalse; }
+ if (ready_to_gc) { scheduleDoGC(cap); }
+ } /* end of while() */
+
+ IF_PAR_DEBUG(verbose,
+ debugBelch("== Leaving schedule() after having received Finish\n"));
+}
+
+/* ----------------------------------------------------------------------------
+ * Setting up the scheduler loop
+ * ASSUMES: sched_mutex
+ * ------------------------------------------------------------------------- */
+
+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
+}
+
+/* ----------------------------------------------------------------------------
+ * Start any pending signal handlers
+ * ASSUMES: sched_mutex
+ * ------------------------------------------------------------------------- */
+
+static void
+scheduleStartSignalHandlers(void)
+{
+#if defined(RTS_USER_SIGNALS) && !defined(RTS_SUPPORTS_THREADS)
+ if (signals_pending()) {
+ RELEASE_LOCK(&sched_mutex); /* ToDo: kill */
+ startSignalHandlers();
+ ACQUIRE_LOCK(&sched_mutex);
+ }
+#endif
+}
+
+/* ----------------------------------------------------------------------------
+ * Check for blocked threads that can be woken up.
+ * ASSUMES: sched_mutex
+ * ------------------------------------------------------------------------- */
+
+static void
+scheduleCheckBlockedThreads(void)
+{
+ //
+ // 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 ( !EMPTY_QUEUE(blocked_queue_hd) || !EMPTY_QUEUE(sleeping_queue) )
+ {
+#if defined(RTS_SUPPORTS_THREADS)
+ // We shouldn't be here...
+ barf("schedule: awaitEvent() in threaded RTS");
+#endif
+ awaitEvent( EMPTY_RUN_QUEUE() && !blackholes_need_checking );
+ }
+}
+
+
+/* ----------------------------------------------------------------------------
+ * Check for threads blocked on BLACKHOLEs that can be woken up
+ * ASSUMES: sched_mutex
+ * ------------------------------------------------------------------------- */
+static void
+scheduleCheckBlackHoles( void )
+{
+ if ( blackholes_need_checking )
+ {
+ checkBlackHoles();
+ blackholes_need_checking = rtsFalse;
+ }
+}
+
+/* ----------------------------------------------------------------------------
+ * Detect deadlock conditions and attempt to resolve them.
+ * ASSUMES: sched_mutex
+ * ------------------------------------------------------------------------- */
+
+static void
+scheduleDetectDeadlock(void)
+{
+
+#if defined(PARALLEL_HASKELL)
+ // ToDo: add deadlock detection in GUM (similar to SMP) -- 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 ( EMPTY_THREAD_QUEUES() )
+ {
+#if defined(RTS_SUPPORTS_THREADS)
+ /*
+ * 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.
+
+ GarbageCollect(GetRoots,rtsTrue);
+ recent_activity = ACTIVITY_DONE_GC;
+ if ( !EMPTY_RUN_QUEUE() ) return;
+
+#if defined(RTS_USER_SIGNALS) && !defined(RTS_SUPPORTS_THREADS)
+ /* 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()) {
+ RELEASE_LOCK(&sched_mutex);
startSignalHandlers();
ACQUIRE_LOCK(&sched_mutex);
}
- ASSERT(!EMPTY_RUN_QUEUE());
- goto not_deadlocked;
+
+ // either we have threads to run, or we were interrupted:
+ ASSERT(!EMPTY_RUN_QUEUE() || interrupted);
}
#endif
+#if !defined(RTS_SUPPORTS_THREADS)
/* 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
*/
{
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");
- }
- }
-#else
m = main_threads;
switch (m->tso->why_blocked) {
+ case BlockedOnSTM:
case BlockedOnBlackHole:
- raiseAsync(m->tso, (StgClosure *)NonTermination_closure);
- break;
case BlockedOnException:
case BlockedOnMVar:
- raiseAsync(m->tso, (StgClosure *)Deadlock_closure);
- break;
+ raiseAsync(m->tso, (StgClosure *)NonTermination_closure);
+ return;
default:
barf("deadlock: main thread blocked in a strange way");
}
-#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."));
- RELEASE_LOCK(&sched_mutex);
- shutdownHaskell();
- return;
-#endif
- }
- not_deadlocked:
-
-#elif defined(RTS_SUPPORTS_THREADS)
- /* ToDo: add deadlock detection in threaded RTS */
-#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.
- */
- if (ready_to_gc) {
- IF_DEBUG(scheduler,sched_belch("waiting for GC"));
- waitCondition( &gc_pending_cond, &sched_mutex );
}
-#endif
-
-#if defined(RTS_SUPPORTS_THREADS)
-#if defined(SMP)
- /* 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 we're in the process of shutting down (& running the
- * a batch of finalisers), don't wait around.
- */
- if ( shutting_down_scheduler ) {
- RELEASE_LOCK(&sched_mutex);
- return;
- }
- 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()));
- }
-#else
- if ( EMPTY_RUN_QUEUE() ) {
- continue; // nothing to do
- }
-#endif
-#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
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(EMPTY_RUN_QUEUE());
+/* 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(EMPTY_RUN_QUEUE());
+
+ 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
- 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 ((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;
-
-run_thread:
-
- RELEASE_LOCK(&sched_mutex);
-
- IF_DEBUG(scheduler, sched_belch("-->> running thread %ld %s ...",
- t->id, whatNext_strs[t->what_next]));
-
-#ifdef PROFILING
- startHeapProfTimer();
-#endif
+/* ----------------------------------------------------------------------------
+ * After running a thread...
+ * ASSUMES: sched_mutex
+ * ------------------------------------------------------------------------- */
- /* +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ */
- /* Run the current thread
- */
- prev_what_next = t->what_next;
- switch (prev_what_next) {
- case ThreadKilled:
- case ThreadComplete:
- /* Thread already finished, return to scheduler. */
- ret = ThreadFinished;
- break;
- case ThreadRunGHC:
- ret = StgRun((StgFunPtr) stg_returnToStackTop, &cap->r);
- break;
- case ThreadInterpret:
- 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);
-
-#ifdef RTS_SUPPORTS_THREADS
- 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 (%s) stopped: requesting a large block (size %d)",
- t->id, 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. 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 = g0s0;
- x->gen_no = 0;
- x->flags = 0;
- }
- }
-
- // don't forget to update the block count in g0s0.
- g0s0->n_blocks += blocks;
- // This assert can be a killer if the app is doing lots
- // of large block allocations.
- 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 (%s) stopped: HeapOverflow",
- t->id, 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 (%s) stopped, StackOverflow",
- t->id, 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 != prev_what_next) {
- belch("--<< thread %ld (%s) stopped to switch evaluators",
- t->id, whatNext_strs[t->what_next]);
- } else {
- belch("--<< thread %ld (%s) stopped, yielding",
- t->id, whatNext_strs[t->what_next]);
- }
- );
-
- IF_DEBUG(sanity,
- //belch("&& 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) {
- goto run_thread;
- }
-
- threadPaused(t);
-
-#if defined(GRAN)
- ASSERT(!is_on_queue(t,CurrentProc));
-
- 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;
+# endif
+ 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))
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,
+# elif defined(PAR)
+//++PAR++ blockThread() writes the event (change?)
+# endif
+ break;
- if (t->block_info.closure!=(StgClosure*)NULL)
- print_bq(t->block_info.closure));
+ case ThreadFinished:
+ break;
- /* Send a fetch (if BlockedOnGA) and dump event to log file */
- blockThread(t);
+ default:
+ barf("parGlobalStats: unknown return code");
+ break;
+ }
+#endif
+}
- /* whatever we schedule next, we must log that schedule */
- emitSchedule = rtsTrue;
+/* -----------------------------------------------------------------------------
+ * Handle a thread that returned to the scheduler with ThreadHeepOverflow
+ * ASSUMES: sched_mutex
+ * -------------------------------------------------------------------------- */
-#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 (%s) stopped: ",
- t->id, whatNext_strs[t->what_next]);
- printThreadBlockage(t);
- fprintf(stderr, "\n"));
-
- /* Only for dumping event to log file
- ToDo: do I need this in GranSim, too?
- blockThread(t);
- */
+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.
+
+ bd = allocGroup( blocks );
+ 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(SMP)
+ 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.
+ PUSH_ON_RUN_QUEUE(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
- 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 (%s) finished",
- t->id, whatNext_strs[t->what_next]));
+ PUSH_ON_RUN_QUEUE(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
+ * ASSUMES: sched_mutex
+ * -------------------------------------------------------------------------- */
+
+static void
+scheduleHandleStackOverflow( 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(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).
+ */
+ if (t->main != NULL) {
+ t->main->tso = new_t;
+ }
+ PUSH_ON_RUN_QUEUE(new_t);
+ }
+}
+
+/* -----------------------------------------------------------------------------
+ * Handle a thread that returned to the scheduler with ThreadYielding
+ * ASSUMES: sched_mutex
+ * -------------------------------------------------------------------------- */
+
+static rtsBool
+scheduleHandleYield( 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)
- endThread(t, CurrentProc); // clean-up the thread
+ ASSERT(!is_on_queue(t,CurrentProc));
+
+ IF_DEBUG(sanity,
+ //debugBelch("&& Doing sanity check on all ThreadQueues (and their TSOs).");
+ checkThreadQsSanity(rtsTrue));
+
+#endif
+
+ addToRunQueue(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
+ * ASSUMES: sched_mutex
+ * -------------------------------------------------------------------------- */
+
+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,
+ 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 */
+
+ // 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.
+
+#if !defined(SMP)
+ ASSERT(t->why_blocked != NotBlocked);
+ // This might not be true under SMP: 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
+
+ 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
+}
+
+/* -----------------------------------------------------------------------------
+ * Handle a thread that returned to the scheduler with ThreadFinished
+ * ASSUMES: sched_mutex
+ * -------------------------------------------------------------------------- */
+
+static rtsBool
+scheduleHandleThreadFinished( StgMainThread *mainThread
+ USED_WHEN_RTS_SUPPORTS_THREADS,
+ Capability *cap,
+ 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]));
+
+#if defined(GRAN)
+ endThread(t, CurrentProc); // clean-up the thread
+#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 main
+ // 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 (
+#if defined(RTS_SUPPORTS_THREADS)
+ mainThread != NULL
+#else
+ mainThread->tso == t
#endif
- break;
-
- default:
- barf("schedule: invalid thread return code %d", (int)ret);
- }
+ )
+ {
+ // We are a bound thread: this must be our thread that just
+ // completed.
+ ASSERT(mainThread->tso == t);
+
+ if (t->what_next == ThreadComplete) {
+ if (mainThread->ret) {
+ // NOTE: return val is tso->sp[1] (see StgStartup.hc)
+ *(mainThread->ret) = (StgClosure *)mainThread->tso->sp[1];
+ }
+ mainThread->stat = Success;
+ } else {
+ if (mainThread->ret) {
+ *(mainThread->ret) = NULL;
+ }
+ if (interrupted) {
+ mainThread->stat = Interrupted;
+ } else {
+ mainThread->stat = Killed;
+ }
+ }
+#ifdef DEBUG
+ removeThreadLabel((StgWord)mainThread->tso->id);
+#endif
+ if (mainThread->prev == NULL) {
+ ASSERT(mainThread == main_threads);
+ main_threads = mainThread->link;
+ } else {
+ mainThread->prev->link = mainThread->link;
+ }
+ if (mainThread->link != NULL) {
+ mainThread->link->prev = mainThread->prev;
+ }
+ releaseCapability(cap);
+ return rtsTrue; // tells schedule() to return
+ }
-#ifdef PROFILING
+#ifdef RTS_SUPPORTS_THREADS
+ ASSERT(t->main == NULL);
+#else
+ if (t->main != NULL) {
+ // Must be a main 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).
+ APPEND_TO_RUN_QUEUE(t);
+ }
+#endif
+ 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 ||
GarbageCollect(GetRoots, rtsTrue);
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
+ * ASSUMES: sched_mutex
+ * -------------------------------------------------------------------------- */
- if (ready_to_gc
+static void
+scheduleDoGC( Capability *cap STG_UNUSED )
+{
+ StgTSO *t;
#ifdef SMP
- && allFreeCapabilities()
-#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"));
+ static rtsBool waiting_for_gc;
+ int n_capabilities = RtsFlags.ParFlags.nNodes - 1;
+ // subtract one because we're already holding one.
+ Capability *caps[n_capabilities];
#endif
- GarbageCollect(GetRoots,rtsFalse);
- ready_to_gc = rtsFalse;
+
#ifdef SMP
- broadcastCondition(&gc_pending_cond);
+ // 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.
+ //
+
+ // Someone else is already trying to GC
+ if (waiting_for_gc) return;
+ waiting_for_gc = rtsTrue;
+
+ caps[n_capabilities] = cap;
+ while (n_capabilities > 0) {
+ IF_DEBUG(scheduler, sched_belch("ready_to_gc, grabbing all the capabilies (%d left)", n_capabilities));
+ waitForReturnCapability(&sched_mutex, &cap);
+ n_capabilities--;
+ caps[n_capabilities] = cap;
+ }
+
+ waiting_for_gc = rtsFalse;
#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 */
+
+ /* 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.
+ */
+ for (t = all_threads; t != END_TSO_QUEUE; t = t -> link) {
+ if (t -> what_next != ThreadRelocated && t -> trec != NO_TREC && t -> why_blocked == NotBlocked) {
+ if (!stmValidateTransaction (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_(t, NULL, rtsTrue);
+
+#ifdef REG_R1
+ ASSERT(get_itbl((StgClosure *)t->sp)->type == ATOMICALLY_FRAME);
+#endif
+ }
+ }
}
+
+ // so this happens periodically:
+ scheduleCheckBlackHoles();
+
+ IF_DEBUG(scheduler, printAllThreads());
-#if defined(GRAN)
- next_thread:
- IF_GRAN_DEBUG(unused,
- print_eventq(EventHd));
+ /* 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"));
+#endif
+ GarbageCollect(GetRoots,rtsFalse);
+
+#if defined(SMP)
+ {
+ // release our stash of capabilities.
+ nat i;
+ for (i = 0; i < RtsFlags.ParFlags.nNodes-1; i++) {
+ releaseCapability(caps[i]);
+ }
+ }
+#endif
- event = get_next_event();
-#elif defined(PAR)
- next_thread:
- /* ToDo: wait for next message to arrive rather than busy wait */
+#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) */
+/* ---------------------------------------------------------------------------
+ * rtsSupportsBoundThreads(): is the RTS built to support bound threads?
+ * used by Control.Concurrent for error checking.
+ * ------------------------------------------------------------------------- */
+
+StgBool
+rtsSupportsBoundThreads(void)
+{
+#if defined(RTS_SUPPORTS_THREADS)
+ return rtsTrue;
+#else
+ return rtsFalse;
+#endif
+}
- IF_PAR_DEBUG(verbose,
- belch("== Leaving schedule() after having received Finish"));
+/* ---------------------------------------------------------------------------
+ * isThreadBound(tso): check whether tso is bound to an OS thread.
+ * ------------------------------------------------------------------------- */
+
+StgBool
+isThreadBound(StgTSO* tso USED_IN_THREADED_RTS)
+{
+#if defined(RTS_SUPPORTS_THREADS)
+ return (tso->main != NULL);
+#endif
+ return rtsFalse;
}
/* ---------------------------------------------------------------------------
* Singleton fork(). Do not copy any running threads.
* ------------------------------------------------------------------------- */
-StgInt forkProcess(StgTSO* tso) {
+#ifndef mingw32_HOST_OS
+#define FORKPROCESS_PRIMOP_SUPPORTED
+#endif
-#ifndef mingw32_TARGET_OS
+#ifdef FORKPROCESS_PRIMOP_SUPPORTED
+static void
+deleteThreadImmediately(StgTSO *tso);
+#endif
+StgInt
+forkProcess(HsStablePtr *entry
+#ifndef FORKPROCESS_PRIMOP_SUPPORTED
+ STG_UNUSED
+#endif
+ )
+{
+#ifdef FORKPROCESS_PRIMOP_SUPPORTED
pid_t pid;
StgTSO* t,*next;
StgMainThread *m;
- rtsBool doKill;
+ SchedulerStatus rc;
IF_DEBUG(scheduler,sched_belch("forking!"));
+ rts_lock(); // This not only acquires sched_mutex, it also
+ // makes sure that no other threads are running
pid = fork();
+
if (pid) { /* parent */
/* just return the pid */
+ rts_unlock();
+ return pid;
} else { /* child */
- /* wipe all other threads */
- run_queue_hd = run_queue_tl = tso;
- tso->link = END_TSO_QUEUE;
-
- /* When clearing out the threads, we need to ensure
- that a 'main thread' is left behind; if there isn't,
- the Scheduler will shutdown next time it is entered.
-
- ==> we don't kill a thread that's on the main_threads
- list (nor the current thread.)
- [ Attempts at implementing the more ambitious scheme of
- killing the main_threads also, and then adding the
- current thread onto the main_threads list if it wasn't
- there already, failed -- waitThread() (for one) wasn't
- up to it. If it proves to be desirable to also kill
- the main threads, then this scheme will have to be
- revisited (and fully debugged!)
-
- -- sof 7/2002
- ]
- */
- /* DO NOT TOUCH THE QUEUES directly because most of the code around
- us is picky about finding the thread still in its queue when
- handling the deleteThread() */
-
- for (t = all_threads; t != END_TSO_QUEUE; t = next) {
- next = t->link;
- /* Don't kill the current thread.. */
- if (t->id == tso->id) continue;
- doKill=rtsTrue;
- /* ..or a main thread */
- for (m = main_threads; m != NULL; m = m->link) {
- if (m->tso->id == t->id) {
- doKill=rtsFalse;
- break;
- }
+ // delete all threads
+ run_queue_hd = run_queue_tl = END_TSO_QUEUE;
+
+ for (t = all_threads; t != END_TSO_QUEUE; t = next) {
+ next = t->link;
+
+ // don't allow threads to catch the ThreadKilled exception
+ deleteThreadImmediately(t);
}
- if (doKill) {
- deleteThread(t);
+
+ // wipe the main thread list
+ while((m = main_threads) != NULL) {
+ main_threads = m->link;
+# ifdef THREADED_RTS
+ closeCondition(&m->bound_thread_cond);
+# endif
+ stgFree(m);
}
+
+ rc = rts_evalStableIO(entry, NULL); // run the action
+ rts_checkSchedStatus("forkProcess",rc);
+
+ rts_unlock();
+
+ hs_exit(); // clean up and exit
+ stg_exit(0);
}
- }
- return pid;
-#else /* mingw32 */
- barf("forkProcess#: primop not implemented for mingw32, sorry! (%u)\n", tso->id);
- /* pointlessly printing out the TSOs 'id' to avoid CC unused warning. */
+#else /* !FORKPROCESS_PRIMOP_SUPPORTED */
+ barf("forkProcess#: primop not supported, sorry!\n");
return -1;
-#endif /* mingw32 */
+#endif
}
/* ---------------------------------------------------------------------------
* Locks: sched_mutex held.
* ------------------------------------------------------------------------- */
-void deleteAllThreads ( void )
+void
+deleteAllThreads ( void )
{
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(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.
+
+ ASSERT(blocked_queue_hd == END_TSO_QUEUE);
+ ASSERT(blackhole_queue == END_TSO_QUEUE);
+ ASSERT(sleeping_queue == END_TSO_QUEUE);
}
/* startThread and insertThread are now in GranSim.c -- HWL */
-//@node Suspend and Resume, Run queue code, Main scheduling loop, Main scheduling code
-//@subsection Suspend and Resume
-
/* ---------------------------------------------------------------------------
* Suspending & resuming Haskell threads.
*
* ------------------------------------------------------------------------- */
StgInt
-suspendThread( StgRegTable *reg,
- rtsBool concCall
-#if !defined(RTS_SUPPORTS_THREADS) && !defined(DEBUG)
- STG_UNUSED
-#endif
- )
+suspendThread( StgRegTable *reg )
{
nat tok;
Capability *cap;
+ int saved_errno = errno;
/* assume that *reg is a pointer to the StgRegTable part
* of a Capability.
*/
- cap = (Capability *)((void *)reg - sizeof(StgFunTable));
+ cap = (Capability *)((void *)((unsigned char*)reg - sizeof(StgFunTable)));
ACQUIRE_LOCK(&sched_mutex);
IF_DEBUG(scheduler,
- sched_belch("thread %d did a _ccall_gc (is_concurrent: %d)", cap->r.rCurrentTSO->id,concCall));
+ sched_belch("thread %d did a _ccall_gc", cap->r.rCurrentTSO->id));
// XXX this might not be necessary --SDM
cap->r.rCurrentTSO->what_next = ThreadRunGHC;
cap->r.rCurrentTSO->link = suspended_ccalling_threads;
suspended_ccalling_threads = cap->r.rCurrentTSO;
-#if defined(RTS_SUPPORTS_THREADS)
- if(cap->r.rCurrentTSO->blocked_exceptions == NULL)
- {
+ if(cap->r.rCurrentTSO->blocked_exceptions == NULL) {
cap->r.rCurrentTSO->why_blocked = BlockedOnCCall;
cap->r.rCurrentTSO->blocked_exceptions = END_TSO_QUEUE;
- }
- else
- {
+ } else {
cap->r.rCurrentTSO->why_blocked = BlockedOnCCall_NoUnblockExc;
}
-#endif
/* Use the thread ID as the token; it should be unique */
tok = cap->r.rCurrentTSO->id;
/* Hand back capability */
+ cap->r.rInHaskell = rtsFalse;
releaseCapability(cap);
#if defined(RTS_SUPPORTS_THREADS)
/* Preparing to leave the RTS, so ensure there's a native thread/task
waiting to take over.
*/
- IF_DEBUG(scheduler, sched_belch("worker thread (%d, osthread %p): leaving RTS", tok, osThreadId()));
- //if (concCall) { // implementing "safe" as opposed to "threadsafe" is more difficult
- startTask(taskStart);
- //}
+ IF_DEBUG(scheduler, sched_belch("worker (token %d): leaving RTS", tok));
#endif
- /* Other threads _might_ be available for execution; signal this */
- THREAD_RUNNABLE();
RELEASE_LOCK(&sched_mutex);
+
+ errno = saved_errno;
return tok;
}
StgRegTable *
-resumeThread( StgInt tok,
- rtsBool concCall STG_UNUSED )
+resumeThread( StgInt tok )
{
StgTSO *tso, **prev;
Capability *cap;
+ int saved_errno = errno;
#if defined(RTS_SUPPORTS_THREADS)
/* Wait for permission to re-enter the RTS with the result. */
ACQUIRE_LOCK(&sched_mutex);
- grabReturnCapability(&sched_mutex, &cap);
+ waitForReturnCapability(&sched_mutex, &cap);
- IF_DEBUG(scheduler, sched_belch("worker thread (%d, osthread %p): re-entering RTS", tok, osThreadId()));
+ IF_DEBUG(scheduler, sched_belch("worker (token %d): re-entering RTS", tok));
#else
grabCapability(&cap);
#endif
}
tso->link = END_TSO_QUEUE;
-#if defined(RTS_SUPPORTS_THREADS)
- if(tso->why_blocked == BlockedOnCCall)
- {
+ if(tso->why_blocked == BlockedOnCCall) {
awakenBlockedQueueNoLock(tso->blocked_exceptions);
tso->blocked_exceptions = NULL;
}
-#endif
/* Reset blocking status */
tso->why_blocked = NotBlocked;
cap->r.rCurrentTSO = tso;
-#if defined(RTS_SUPPORTS_THREADS)
+ cap->r.rInHaskell = rtsTrue;
RELEASE_LOCK(&sched_mutex);
-#endif
+ errno = saved_errno;
return &cap->r;
}
-
-/* ---------------------------------------------------------------------------
- * Static functions
- * ------------------------------------------------------------------------ */
-static void unblockThread(StgTSO *tso);
-
/* ---------------------------------------------------------------------------
* Comparing Thread ids.
*
buf = stgMallocBytes(len * sizeof(char), "Schedule.c:labelThread()");
strncpy(buf,label,len);
/* Update will free the old memory for us */
- updateThreadLabel((StgWord)tso,buf);
+ updateThreadLabel(((StgTSO *)tso)->id,buf);
}
#endif /* DEBUG */
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 *
nat stack_size;
/* First check whether we should create a thread at all */
-#if defined(PAR)
+#if defined(PARALLEL_HASKELL)
/* 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)",
+ 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;
}
// Always start with the compiled code evaluator
tso->what_next = ThreadRunGHC;
- /* 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.
- */
- ACQUIRE_LOCK(&thread_id_mutex);
tso->id = next_thread_id++;
- RELEASE_LOCK(&thread_id_mutex);
-
tso->why_blocked = NotBlocked;
tso->blocked_exceptions = NULL;
+ tso->saved_errno = 0;
+ tso->main = 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;
#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->link = END_TSO_QUEUE;
+
// ToDo: check this
#if defined(GRAN)
- tso->link = END_TSO_QUEUE;
/* uses more flexible routine in GranSim */
insertThread(tso, CurrentProc);
#else
#if defined(GRAN)
if (RtsFlags.GranFlags.GranSimStats.Full)
DumpGranEvent(GR_START,tso);
-#elif defined(PAR)
+#elif defined(PARALLEL_HASKELL)
if (RtsFlags.ParFlags.ParStats.Full)
DumpGranEvent(GR_STARTQ,tso);
/* HACk to avoid SCHEDULE
tso->gran.clock = 0;
IF_DEBUG(gran,printTSO(tso));
-#elif defined(PAR)
+#elif defined(PARALLEL_HASKELL)
# if defined(DEBUG)
tso->par.magic = TSO_MAGIC; // debugging only
# endif
globalGranStats.threads_created_on_PE[CurrentProc]++;
globalGranStats.tot_sq_len += spark_queue_len(CurrentProc);
globalGranStats.tot_sq_probes++;
-#elif defined(PAR)
+#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) {
- //fprintf(stderr, "Creating thread %d @ %11.2f\n", tso->id, usertime());
+ //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);",
+ sched_belch("==__ schedule: Created TSO %d (%p);",
CurrentProc, tso, tso->id));
-#elif defined(PAR)
- IF_PAR_DEBUG(verbose,
- belch("==__ schedule: Created TSO %d (%p); %d threads active",
- tso->id, tso, advisory_thread_count));
+#elif defined(PARALLEL_HASKELL)
+ IF_PAR_DEBUG(verbose,
+ 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));
+ (long)tso->id, (long)tso->stack_size));
#endif
return tso;
}
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)",
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;
}
#endif
-static SchedulerStatus waitThread_(/*out*/StgMainThread* m
-#if defined(THREADED_RTS)
- , rtsBool blockWaiting
-#endif
- );
-
-
/* ---------------------------------------------------------------------------
* scheduleThread()
*
* on this thread's stack before the scheduler is invoked.
* ------------------------------------------------------------------------ */
-static void scheduleThread_ (StgTSO* tso);
-
-void
+static void
scheduleThread_(StgTSO *tso)
{
- // Precondition: sched_mutex must be held.
-
- /* 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);
- THREAD_RUNNABLE();
-
-#if 0
- IF_DEBUG(scheduler,printTSO(tso));
-#endif
+ // The thread goes at the *end* of the run-queue, to avoid possible
+ // starvation of any threads already on the queue.
+ APPEND_TO_RUN_QUEUE(tso);
+ threadRunnable();
}
-void scheduleThread(StgTSO* tso)
+void
+scheduleThread(StgTSO* tso)
{
ACQUIRE_LOCK(&sched_mutex);
scheduleThread_(tso);
RELEASE_LOCK(&sched_mutex);
}
+#if defined(RTS_SUPPORTS_THREADS)
+static Condition bound_cond_cache;
+static int bound_cond_cache_full = 0;
+#endif
+
+
SchedulerStatus
-scheduleWaitThread(StgTSO* tso, /*[out]*/HaskellObj* ret)
-{ // Precondition: sched_mutex must be held
- StgMainThread *m;
+scheduleWaitThread(StgTSO* tso, /*[out]*/HaskellObj* ret,
+ Capability *initialCapability)
+{
+ // Precondition: sched_mutex must be held
+ StgMainThread *m;
+
+ m = stgMallocBytes(sizeof(StgMainThread), "waitThread");
+ m->tso = tso;
+ tso->main = m;
+ m->ret = ret;
+ m->stat = NoStatus;
+ m->link = main_threads;
+ m->prev = NULL;
+ if (main_threads != NULL) {
+ main_threads->prev = m;
+ }
+ main_threads = m;
- m = stgMallocBytes(sizeof(StgMainThread), "waitThread");
- m->tso = tso;
- m->ret = ret;
- m->stat = NoStatus;
#if defined(RTS_SUPPORTS_THREADS)
- initCondition(&m->wakeup);
+ // Allocating a new condition for each thread is expensive, so we
+ // cache one. This is a pretty feeble hack, but it helps speed up
+ // consecutive call-ins quite a bit.
+ if (bound_cond_cache_full) {
+ m->bound_thread_cond = bound_cond_cache;
+ bound_cond_cache_full = 0;
+ } else {
+ initCondition(&m->bound_thread_cond);
+ }
#endif
- /* Put the thread on the main-threads list prior to scheduling the TSO.
- Failure to do so introduces a race condition in the MT case (as
- identified by Wolfgang Thaller), whereby the new task/OS thread
- created by scheduleThread_() would complete prior to the thread
- that spawned it managed to put 'itself' on the main-threads list.
- The upshot of it all being that the worker thread wouldn't get to
- signal the completion of the its work item for the main thread to
- see (==> it got stuck waiting.) -- sof 6/02.
- */
- IF_DEBUG(scheduler, sched_belch("waiting for thread (%d)\n", tso->id));
-
- m->link = main_threads;
- main_threads = m;
+ /* Put the thread on the main-threads list prior to scheduling the TSO.
+ Failure to do so introduces a race condition in the MT case (as
+ identified by Wolfgang Thaller), whereby the new task/OS thread
+ created by scheduleThread_() would complete prior to the thread
+ that spawned it managed to put 'itself' on the main-threads list.
+ The upshot of it all being that the worker thread wouldn't get to
+ signal the completion of the its work item for the main thread to
+ see (==> it got stuck waiting.) -- sof 6/02.
+ */
+ IF_DEBUG(scheduler, sched_belch("waiting for thread (%d)", tso->id));
+
+ APPEND_TO_RUN_QUEUE(tso);
+ // NB. Don't call threadRunnable() here, because the thread is
+ // bound and only runnable by *this* OS thread, so waking up other
+ // workers will just slow things down.
- scheduleThread_(tso);
-#if defined(THREADED_RTS)
- return waitThread_(m, rtsTrue);
-#else
- return waitThread_(m);
-#endif
+ return waitThread_(m, initialCapability);
}
/* ---------------------------------------------------------------------------
*
* ------------------------------------------------------------------------ */
-#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)
{
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_tl = END_TSO_QUEUE;
blocked_queue_hd = END_TSO_QUEUE;
blocked_queue_tl = END_TSO_QUEUE;
+ blackhole_queue = END_TSO_QUEUE;
sleeping_queue = END_TSO_QUEUE;
#endif
* the scheduler. */
initMutex(&sched_mutex);
initMutex(&term_mutex);
- initMutex(&thread_id_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).
*/
- 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)
- initSparkPools();
-#endif
-
-#if defined(RTS_SUPPORTS_THREADS)
- RELEASE_LOCK(&sched_mutex);
-#endif
-
-}
-
-void
-exitScheduler( void )
-{
-#if defined(RTS_SUPPORTS_THREADS)
- stopTaskManager();
-#endif
- shutting_down_scheduler = rtsTrue;
-}
-
-/* -----------------------------------------------------------------------------
- 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)
-{
- StgMainThread *m;
- SchedulerStatus stat;
-
- m = stgMallocBytes(sizeof(StgMainThread), "waitThread");
- m->tso = tso;
- m->ret = ret;
- m->stat = NoStatus;
+ initCapabilities();
+
#if defined(RTS_SUPPORTS_THREADS)
- initCondition(&m->wakeup);
+ initTaskManager();
#endif
- /* see scheduleWaitThread() comment */
- ACQUIRE_LOCK(&sched_mutex);
- m->link = main_threads;
- main_threads = m;
+#if defined(SMP)
+ /* eagerly start some extra workers */
+ startingWorkerThread = RtsFlags.ParFlags.nNodes;
+ startTasks(RtsFlags.ParFlags.nNodes, taskStart);
+#endif
- IF_DEBUG(scheduler, sched_belch("waiting for thread %d", tso->id));
-#if defined(THREADED_RTS)
- stat = waitThread_(m, rtsFalse);
-#else
- stat = waitThread_(m);
+#if /* defined(SMP) ||*/ defined(PARALLEL_HASKELL)
+ initSparkPools();
#endif
+
RELEASE_LOCK(&sched_mutex);
- return stat;
}
-static
-SchedulerStatus
-waitThread_(StgMainThread* m
-#if defined(THREADED_RTS)
- , rtsBool blockWaiting
+void
+exitScheduler( void )
+{
+ interrupted = rtsTrue;
+ shutting_down_scheduler = rtsTrue;
+#if defined(RTS_SUPPORTS_THREADS)
+ if (threadIsTask(osThreadId())) { taskStop(); }
+ 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???
+ ------------------------------------------------------------------------- */
+
+static SchedulerStatus
+waitThread_(StgMainThread* m, Capability *initialCapability)
{
SchedulerStatus stat;
// Precondition: sched_mutex must be held.
- IF_DEBUG(scheduler, sched_belch("== scheduler: new main thread (%d)\n", m->tso->id));
-
-#if defined(RTS_SUPPORTS_THREADS)
+ IF_DEBUG(scheduler, sched_belch("new main thread (%d)", m->tso->id));
-# 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.
- */
- main_main_thread = m;
- RELEASE_LOCK(&sched_mutex);
- schedule();
- ACQUIRE_LOCK(&sched_mutex);
- main_main_thread = NULL;
- ASSERT(m->stat != NoStatus);
- } else
-# endif
- {
- do {
- waitCondition(&m->wakeup, &sched_mutex);
- } while (m->stat == NoStatus);
- }
-#elif defined(GRAN)
+#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
-
- RELEASE_LOCK(&sched_mutex);
- schedule();
+ schedule(m,initialCapability);
#else
- RELEASE_LOCK(&sched_mutex);
- schedule();
+ schedule(m,initialCapability);
ASSERT(m->stat != NoStatus);
#endif
stat = m->stat;
#if defined(RTS_SUPPORTS_THREADS)
- closeCondition(&m->wakeup);
+ // Free the condition variable, returning it to the cache if possible.
+ if (!bound_cond_cache_full) {
+ bound_cond_cache = m->bound_thread_cond;
+ bound_cond_cache_full = 1;
+ } else {
+ closeCondition(&m->bound_thread_cond);
+ }
#endif
- IF_DEBUG(scheduler, fprintf(stderr, "== scheduler: main thread (%d) finished\n",
- m->tso->id));
+ IF_DEBUG(scheduler, sched_belch("main thread (%d) finished", m->tso->id));
stgFree(m);
// Postcondition: sched_mutex still held
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;
- }
- }
- }
- return t;
-}
-
-#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 )
{
#if defined(GRAN)
{
}
#endif
+ if (blackhole_queue != END_TSO_QUEUE) {
+ evac((StgClosure **)&blackhole_queue);
+ }
+
if (suspended_ccalling_threads != END_TSO_QUEUE) {
evac((StgClosure **)&suspended_ccalling_threads);
}
-#if defined(PAR) || defined(GRAN)
+#if defined(PARALLEL_HASKELL) || defined(GRAN)
markSparkQueue(evac);
#endif
// mark the signal handlers (signals should be already blocked)
markSignalHandlers(evac);
#endif
-
- // main threads which have completed need to be retained until they
- // are dealt with in the main scheduler loop. They won't be
- // retained any other way: the GC will drop them from the
- // all_threads list, so we have to be careful to treat them as roots
- // here.
- {
- StgMainThread *m;
- for (m = main_threads; m != NULL; m = m->link) {
- switch (m->tso->what_next) {
- case ThreadComplete:
- case ThreadKilled:
- evac((StgClosure **)&m->tso);
- break;
- default:
- break;
- }
- }
- }
}
/* -----------------------------------------------------------------------------
static StgTSO *
threadStackOverflow(StgTSO *tso)
{
- nat new_stack_size, new_tso_size, 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)));
* 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, debugBelch("== sched: increasing stack size from %d words to %d.\n", tso->stack_size, new_stack_size));
dest = (StgTSO *)allocate(new_tso_size);
TICK_ALLOC_TSO(new_stack_size,0);
tso->link = dest;
tso->sp = (P_)&(tso->stack[tso->stack_size]);
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
#endif
#if defined(GRAN)
-static StgBlockingQueueElement *
+StgBlockingQueueElement *
unblockOneLocked(StgBlockingQueueElement *bqe, StgClosure *node)
{
StgTSO *tso;
}
/* 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 *
+#elif defined(PARALLEL_HASKELL)
+StgBlockingQueueElement *
unblockOneLocked(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;
(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;
}
-#else /* !GRAN && !PAR */
-static StgTSO *
+#else /* !GRAN && !PARALLEL_HASKELL */
+StgTSO *
unblockOneLocked(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;
+ APPEND_TO_RUN_QUEUE(tso);
+ threadRunnable();
+ IF_DEBUG(scheduler,sched_belch("waking up thread %ld", (long)tso->id));
return next;
}
#endif
-#if defined(GRAN) || defined(PAR)
-inline StgBlockingQueueElement *
+#if defined(GRAN) || defined(PARALLEL_HASKELL)
+INLINE_ME StgBlockingQueueElement *
unblockOne(StgBlockingQueueElement *bqe, StgClosure *node)
{
ACQUIRE_LOCK(&sched_mutex);
return bqe;
}
#else
-inline StgTSO *
+INLINE_ME StgTSO *
unblockOne(StgTSO *tso)
{
ACQUIRE_LOCK(&sched_mutex);
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++;
((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)
{
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
RELEASE_LOCK(&sched_mutex);
}
-#else /* !GRAN && !PAR */
+#else /* !GRAN && !PARALLEL_HASKELL */
-#ifdef RTS_SUPPORTS_THREADS
void
awakenBlockedQueueNoLock(StgTSO *tso)
{
tso = unblockOneLocked(tso);
}
}
-#endif
void
awakenBlockedQueue(StgTSO *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.
{
interrupted = 1;
context_switch = 1;
+ threadRunnable();
+ /* ToDo: if invoked from a signal handler, this threadRunnable
+ * only works if there's another thread (not this one) waiting to
+ * be woken up.
+ */
}
/* -----------------------------------------------------------------------------
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
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:
switch (tso->why_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;
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");
}
default:
tso->link = END_TSO_QUEUE;
tso->why_blocked = NotBlocked;
tso->block_info.closure = NULL;
- PUSH_ON_RUN_QUEUE(tso);
+ APPEND_TO_RUN_QUEUE(tso);
}
#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( void )
+{
+ StgTSO **prev, *t;
+ rtsBool any_woke_up = rtsFalse;
+ StgHalfWord type;
+
+ 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) {
+ t = unblockOneLocked(t);
+ *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
void
deleteThread(StgTSO *tso)
{
- raiseAsync(tso,NULL);
+ if (tso->why_blocked != BlockedOnCCall &&
+ tso->why_blocked != BlockedOnCCall_NoUnblockExc) {
+ raiseAsync(tso,NULL);
+ }
+}
+
+#ifdef FORKPROCESS_PRIMOP_SUPPORTED
+static void
+deleteThreadImmediately(StgTSO *tso)
+{ // for forkProcess only:
+ // delete thread without giving it a chance to catch the KillThread exception
+
+ if (tso->what_next == ThreadComplete || tso->what_next == ThreadKilled) {
+ return;
+ }
+
+ if (tso->why_blocked != BlockedOnCCall &&
+ tso->why_blocked != BlockedOnCCall_NoUnblockExc) {
+ unblockThread(tso);
+ }
+
+ tso->what_next = ThreadKilled;
}
+#endif
void
raiseAsyncWithLock(StgTSO *tso, StgClosure *exception)
void
raiseAsync(StgTSO *tso, StgClosure *exception)
{
+ raiseAsync_(tso, exception, rtsFalse);
+}
+
+static void
+raiseAsync_(StgTSO *tso, StgClosure *exception, rtsBool stop_at_atomically)
+{
StgRetInfoTable *info;
StgPtr sp;
}
IF_DEBUG(scheduler,
- sched_belch("raising exception in thread %ld.", tso->id));
+ sched_belch("raising exception in thread %ld.", (long)tso->id));
// Remove it from any blocking queues
unblockThread(tso);
// 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
+
StgPtr frame;
while (info->i.type != UPDATE_FRAME
&& (info->i.type != CATCH_FRAME || exception == NULL)
- && info->i.type != STOP_FRAME) {
+ && info->i.type != STOP_FRAME
+ && (info->i.type != ATOMICALLY_FRAME || stop_at_atomically == rtsFalse))
+ {
+ if (info->i.type == CATCH_RETRY_FRAME || info->i.type == ATOMICALLY_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"));
+ stmAbortTransaction(tso -> trec);
+ tso -> trec = stmGetEnclosingTRec(tso -> trec);
+ }
frame += stack_frame_sizeW((StgClosure *)frame);
info = get_ret_itbl((StgClosure *)frame);
}
switch (info->i.type) {
+ case ATOMICALLY_FRAME:
+ ASSERT(stop_at_atomically);
+ ASSERT(stmGetEnclosingTRec(tso->trec) == NO_TREC);
+ stmCondemnTransaction(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;
+
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
#ifdef PROFILING
StgCatchFrame *cf = (StgCatchFrame *)frame;
#endif
- StgClosure *raise;
+ StgThunk *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);
+ raise = (StgThunk *)allocate(sizeofW(StgThunk)+1);
TICK_ALLOC_SE_THK(1,0);
SET_HDR(raise,&stg_raise_info,cf->header.prof.ccs);
raise->payload[0] = exception;
// fun field.
//
words = frame - sp - 1;
- ap = (StgAP_STACK *)allocate(PAP_sizeW(words));
+ ap = (StgAP_STACK *)allocate(AP_STACK_sizeW(words));
ap->size = words;
ap->fun = (StgClosure *)sp[0];
TICK_ALLOC_UP_THK(words+1,0);
IF_DEBUG(scheduler,
- fprintf(stderr, "scheduler: Updating ");
+ debugBelch("sched: Updating ");
printPtr((P_)((StgUpdateFrame *)frame)->updatee);
- fprintf(stderr, " with ");
+ debugBelch(" with ");
printObj((StgClosure *)ap);
);
//
if (!closure_IND(((StgUpdateFrame *)frame)->updatee)) {
// revert the black hole
- UPD_IND_NOLOCK(((StgUpdateFrame *)frame)->updatee,ap);
+ UPD_IND_NOLOCK(((StgUpdateFrame *)frame)->updatee,
+ (StgClosure *)ap);
}
sp += sizeofW(StgUpdateFrame) - 1;
sp[0] = (W_)ap; // push onto stack
}
/* -----------------------------------------------------------------------------
+ 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.
+ -------------------------------------------------------------------------- */
+
+StgWord
+raiseExceptionHelper (StgTSO *tso, StgClosure *exception)
+{
+ 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.
+ //
+
+ //
+ // 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 *)allocate(sizeofW(StgThunk)+MIN_UPD_SIZE);
+ SET_HDR(raise_closure, &stg_raise_info, CCCS);
+ raise_closure->payload[0] = exception;
+ }
+ UPD_IND(((StgUpdateFrame *)p)->updatee,(StgClosure *)raise_closure);
+ p = next;
+ continue;
+
+ 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;
+ }
+ }
+}
+
+
+/* -----------------------------------------------------------------------------
+ findRetryFrameHelper
+
+ This function is called by the retry# primitive. It traverses the stack
+ leaving tso->sp referring to the frame which should handle the retry.
+
+ 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).
+
+ 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;
+
+ 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;
+ }
+ }
+}
+
+/* -----------------------------------------------------------------------------
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
case BlockedOnBlackHole:
raiseAsync(tso,(StgClosure *)NonTermination_closure);
break;
+ case BlockedOnSTM:
+ raiseAsync(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
}
}
-/* -----------------------------------------------------------------------------
- * 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.
- *
- * Locks: sched_mutex is held upon entry and exit.
- * -------------------------------------------------------------------------- */
-
-static void
-detectBlackHoles( void )
-{
- StgTSO *tso = all_threads;
- StgClosure *frame;
- StgClosure *blocked_on;
- StgRetInfoTable *info;
-
- for (tso = all_threads; tso != END_TSO_QUEUE; tso = tso->global_link) {
-
- while (tso->what_next == ThreadRelocated) {
- tso = tso->link;
- ASSERT(get_itbl(tso)->type == TSO);
- }
-
- if (tso->why_blocked != BlockedOnBlackHole) {
- continue;
- }
- blocked_on = tso->block_info.closure;
-
- frame = (StgClosure *)tso->sp;
-
- while(1) {
- info = get_ret_itbl(frame);
- switch (info->i.type) {
- case UPDATE_FRAME:
- if (((StgUpdateFrame *)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", tso->id));
- raiseAsync(tso, (StgClosure *)NonTermination_closure);
- goto done;
- }
-
- frame = (StgClosure *) ((StgUpdateFrame *)frame + 1);
- continue;
-
- case STOP_FRAME:
- goto done;
-
- // normal stack frames; do nothing except advance the pointer
- default:
- (StgPtr)frame += stack_frame_sizeW(frame);
- }
- }
- done: ;
- }
-}
-
-//@node Debugging Routines, Index, Exception Handling Routines, Main scheduling code
-//@subsection Debugging Routines
-
-/* -----------------------------------------------------------------------------
+/* ----------------------------------------------------------------------------
* 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]
- -------------------------------------------------------------------------- */
+ ------------------------------------------------------------------------- */
-static
-void
+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");
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:
- fprintf(stderr,"is blocked on an external call (exceptions were already blocked)");
+ 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);
}
}
-static
-void
+static void
printThreadStatus(StgTSO *tso)
{
switch (tso->what_next) {
case ThreadKilled:
- fprintf(stderr,"has been killed");
+ debugBelch("has been killed");
break;
case ThreadComplete:
- fprintf(stderr,"has completed");
+ debugBelch("has completed");
break;
default:
printThreadBlockage(tso);
printAllThreads(void)
{
StgTSO *t;
- void *label;
# 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!*/);
- fprintf(stderr, "all threads at [%s]:\n", 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!*/);
- fprintf(stderr,"all threads at [%s]:\n", time_string);
+ debugBelch("all threads at [%s]:\n", time_string);
# else
- fprintf(stderr,"all threads:\n");
+ debugBelch("all threads:\n");
# endif
- for (t = all_threads; t != END_TSO_QUEUE; t = t->global_link) {
- fprintf(stderr, "\tthread %d @ %p ", t->id, (void *)t);
- label = lookupThreadLabel((StgWord)t);
- if (label) fprintf(stderr,"[\"%s\"] ",(char *)label);
- printThreadStatus(t);
- fprintf(stderr,"\n");
+ for (t = all_threads; t != END_TSO_QUEUE; ) {
+ debugBelch("\tthread %d @ %p ", t->id, (void *)t);
+#if defined(DEBUG)
+ {
+ void *label = lookupThreadLabel(t->id);
+ if (label) debugBelch("[\"%s\"] ",(char *)label);
+ }
+#endif
+ if (t->what_next == ThreadRelocated) {
+ debugBelch("has been relocated...\n");
+ t = t->link;
+ } else {
+ printThreadStatus(t);
+ debugBelch("\n");
+ t = t->global_link;
+ }
}
}
/*
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)
{
}
#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, "== ");
+#ifdef RTS_SUPPORTS_THREADS
+ debugBelch("sched (task %p): ", 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