/* ---------------------------------------------------------------------------
- * $Id: Schedule.c,v 1.199 2004/08/09 14:27:53 simonmar Exp $
*
- * (c) The GHC Team, 1998-2003
+ * (c) The GHC Team, 1998-2005
*
- * Scheduler
- *
- * Different GHC ways use this scheduler quite differently (see comments below)
- * Here is the global picture:
- *
- * WAY Name CPP flag What's it for
- * --------------------------------------
- * mp GUM PAR Parallel execution on a 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)
+ * The scheduler and thread-related functionality
*
* --------------------------------------------------------------------------*/
-/*
- * Version with support for distributed memory parallelism aka GUM (WAY=mp):
-
- The main scheduling loop in GUM iterates until a finish message is received.
- In that case a global flag @receivedFinish@ is set and this instance of
- the RTS shuts down. See ghc/rts/parallel/HLComms.c:processMessages()
- for the handling of incoming messages, such as PP_FINISH.
- Note that in the parallel case we have a system manager that coordinates
- different PEs, each of which are running one instance of the RTS.
- See ghc/rts/parallel/SysMan.c for the main routine of the parallel program.
- From this routine processes executing ghc/rts/Main.c are spawned. -- HWL
-
- * Version with support for simulating parallel execution aka GranSim (WAY=mg):
-
- The main scheduling code in GranSim is quite different from that in std
- (concurrent) Haskell: while concurrent Haskell just iterates over the
- threads in the runnable queue, GranSim is event driven, i.e. it iterates
- over the events in the global event queue. -- HWL
-*/
-
#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 "RtsSignals.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"
+#include "Task.h"
+#include "AwaitEvent.h"
+#if defined(mingw32_HOST_OS)
+#include "win32/IOManager.h"
+#endif
#ifdef HAVE_SYS_TYPES_H
#include <sys/types.h>
#include <errno.h>
#endif
-#ifdef THREADED_RTS
-#define USED_IN_THREADED_RTS
-#else
-#define USED_IN_THREADED_RTS STG_UNUSED
-#endif
-
-#ifdef RTS_SUPPORTS_THREADS
-#define USED_WHEN_RTS_SUPPORTS_THREADS
-#else
-#define USED_WHEN_RTS_SUPPORTS_THREADS STG_UNUSED
+// Turn off inlining when debugging - it obfuscates things
+#ifdef DEBUG
+# undef STATIC_INLINE
+# define STATIC_INLINE static
#endif
-/* Main thread queue.
- * Locks required: sched_mutex.
- */
-StgMainThread *main_threads = NULL;
+/* -----------------------------------------------------------------------------
+ * Global variables
+ * -------------------------------------------------------------------------- */
-/* Thread queues.
- * Locks required: sched_mutex.
- */
#if defined(GRAN)
StgTSO* ActiveTSO = NULL; /* for assigning system costs; GranSim-Light only */
#else /* !GRAN */
-StgTSO *run_queue_hd = NULL;
-StgTSO *run_queue_tl = NULL;
+#if !defined(THREADED_RTS)
+// Blocked/sleeping thrads
StgTSO *blocked_queue_hd = NULL;
StgTSO *blocked_queue_tl = NULL;
-StgTSO *sleeping_queue = NULL; /* perhaps replace with a hash table? */
+StgTSO *sleeping_queue = NULL; // perhaps replace with a hash table?
+#endif
+/* Threads blocked on blackholes.
+ * LOCK: sched_mutex+capability, or all capabilities
+ */
+StgTSO *blackhole_queue = NULL;
#endif
+/* The blackhole_queue should be checked for threads to wake up. See
+ * Schedule.h for more thorough comment.
+ * LOCK: none (doesn't matter if we miss an update)
+ */
+rtsBool blackholes_need_checking = rtsFalse;
+
/* Linked list of all threads.
* Used for detecting garbage collected threads.
+ * LOCK: sched_mutex+capability, or all capabilities
*/
StgTSO *all_threads = NULL;
-/* When a thread performs a safe C call (_ccall_GC, using old
- * terminology), it gets put on the suspended_ccalling_threads
- * list. Used by the garbage collector.
+/* flag set by signal handler to precipitate a context switch
+ * LOCK: none (just an advisory flag)
*/
-static StgTSO *suspended_ccalling_threads;
+int context_switch = 0;
-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 */
-nat context_switch = 0;
+/* flag that tracks whether we have done any execution in this time slice.
+ * LOCK: currently none, perhaps we should lock (but needs to be
+ * updated in the fast path of the scheduler).
+ */
+nat recent_activity = ACTIVITY_YES;
-/* if this flag is set as well, give up execution */
+/* if this flag is set as well, give up execution
+ * LOCK: none (changes once, from false->true)
+ */
rtsBool interrupted = rtsFalse;
/* Next thread ID to allocate.
- * Locks required: thread_id_mutex
+ * LOCK: sched_mutex
*/
static StgThreadID next_thread_id = 1;
-/*
- * Pointers to the state of the current thread.
- * Rule of thumb: if CurrentTSO != NULL, then we're running a Haskell
- * thread. If CurrentTSO == NULL, then we're at the scheduler level.
- */
-
/* The smallest stack size that makes any sense is:
* RESERVED_STACK_WORDS (so we can get back from the stack overflow)
* + sizeofW(StgStopFrame) (the stg_stop_thread_info frame)
* 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) + 3)
-
#if defined(GRAN)
StgTSO *CurrentTSO;
#endif
*/
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
* in the scheduler when it is out of work.
*/
-static rtsBool shutting_down_scheduler = rtsFalse;
-
-void addToBlockedQueue ( StgTSO *tso );
+rtsBool shutting_down_scheduler = rtsFalse;
-static void schedule ( StgMainThread *mainThread, Capability *initialCapability );
- void interruptStgRts ( void );
-
-static void detectBlackHoles ( void );
-
-#if defined(RTS_SUPPORTS_THREADS)
-/* ToDo: carefully document the invariants that go together
- * with these synchronisation objects.
+/*
+ * This mutex protects most of the global scheduler data in
+ * the THREADED_RTS and (inc. SMP) runtime.
*/
-Mutex sched_mutex = INIT_MUTEX_VAR;
-Mutex term_mutex = INIT_MUTEX_VAR;
-
-#endif /* RTS_SUPPORTS_THREADS */
+#if defined(THREADED_RTS)
+Mutex sched_mutex;
+#endif
-#if defined(PAR)
+#if defined(PARALLEL_HASKELL)
StgTSO *LastTSO;
rtsTime TimeOfLastYield;
rtsBool emitSchedule = rtsTrue;
#endif
-#if DEBUG
+/* -----------------------------------------------------------------------------
+ * static function prototypes
+ * -------------------------------------------------------------------------- */
+
+static Capability *schedule (Capability *initialCapability, Task *task);
+
+//
+// These function all encapsulate parts of the scheduler loop, and are
+// abstracted only to make the structure and control flow of the
+// scheduler clearer.
+//
+static void schedulePreLoop (void);
+#if defined(SMP)
+static void schedulePushWork(Capability *cap, Task *task);
+#endif
+static void scheduleStartSignalHandlers (Capability *cap);
+static void scheduleCheckBlockedThreads (Capability *cap);
+static void scheduleCheckBlackHoles (Capability *cap);
+static void scheduleDetectDeadlock (Capability *cap, Task *task);
+#if defined(GRAN)
+static StgTSO *scheduleProcessEvent(rtsEvent *event);
+#endif
+#if defined(PARALLEL_HASKELL)
+static StgTSO *scheduleSendPendingMessages(void);
+static void scheduleActivateSpark(void);
+static rtsBool scheduleGetRemoteWork(rtsBool *receivedFinish);
+#endif
+#if defined(PAR) || defined(GRAN)
+static void scheduleGranParReport(void);
+#endif
+static void schedulePostRunThread(void);
+static rtsBool scheduleHandleHeapOverflow( Capability *cap, StgTSO *t );
+static void scheduleHandleStackOverflow( Capability *cap, Task *task,
+ StgTSO *t);
+static rtsBool scheduleHandleYield( Capability *cap, StgTSO *t,
+ nat prev_what_next );
+static void scheduleHandleThreadBlocked( StgTSO *t );
+static rtsBool scheduleHandleThreadFinished( Capability *cap, Task *task,
+ StgTSO *t );
+static rtsBool scheduleDoHeapProfile(rtsBool ready_to_gc);
+static void scheduleDoGC(Capability *cap, Task *task, rtsBool force_major);
+
+static void unblockThread(Capability *cap, StgTSO *tso);
+static rtsBool checkBlackHoles(Capability *cap);
+static void AllRoots(evac_fn evac);
+
+static StgTSO *threadStackOverflow(Capability *cap, StgTSO *tso);
+
+static void raiseAsync_(Capability *cap, StgTSO *tso, StgClosure *exception,
+ rtsBool stop_at_atomically, StgPtr stop_here);
+
+static void deleteThread (Capability *cap, StgTSO *tso);
+static void deleteRunQueue (Capability *cap);
+
+#ifdef DEBUG
+static void printThreadBlockage(StgTSO *tso);
+static void printThreadStatus(StgTSO *tso);
+void printThreadQueue(StgTSO *tso);
+#endif
+
+#if defined(PARALLEL_HASKELL)
+StgTSO * createSparkThread(rtsSpark spark);
+StgTSO * activateSpark (rtsSpark spark);
+#endif
+
+#ifdef DEBUG
static char *whatNext_strs[] = {
+ "(unknown)",
"ThreadRunGHC",
"ThreadInterpret",
"ThreadKilled",
};
#endif
-#if defined(PAR)
-StgTSO * createSparkThread(rtsSpark spark);
-StgTSO * activateSpark (rtsSpark spark);
-#endif
-
-/* ----------------------------------------------------------------------------
- * Starting Tasks
- * ------------------------------------------------------------------------- */
-
-#if defined(RTS_SUPPORTS_THREADS)
-static rtsBool startingWorkerThread = rtsFalse;
+/* -----------------------------------------------------------------------------
+ * Putting a thread on the run queue: different scheduling policies
+ * -------------------------------------------------------------------------- */
-static void taskStart(void);
-static void
-taskStart(void)
+STATIC_INLINE void
+addToRunQueue( Capability *cap, StgTSO *t )
{
- ACQUIRE_LOCK(&sched_mutex);
- startingWorkerThread = rtsFalse;
- schedule(NULL,NULL);
- RELEASE_LOCK(&sched_mutex);
-}
-
-void
-startSchedulerTaskIfNecessary(void)
-{
- if(run_queue_hd != END_TSO_QUEUE
- || blocked_queue_hd != END_TSO_QUEUE
- || sleeping_queue != END_TSO_QUEUE)
- {
- if(!startingWorkerThread)
- { // we don't want to start another worker thread
- // just because the last one hasn't yet reached the
- // "waiting for capability" state
- startingWorkerThread = rtsTrue;
- if(!startTask(taskStart))
- {
- startingWorkerThread = rtsFalse;
- }
+#if defined(PARALLEL_HASKELL)
+ if (RtsFlags.ParFlags.doFairScheduling) {
+ // this does round-robin scheduling; good for concurrency
+ appendToRunQueue(cap,t);
+ } else {
+ // this does unfair scheduling; good for parallelism
+ pushOnRunQueue(cap,t);
}
- }
-}
+#else
+ // this does round-robin scheduling; good for concurrency
+ appendToRunQueue(cap,t);
#endif
+}
/* ---------------------------------------------------------------------------
Main scheduling loop.
* thread ends
* stack overflow
- Locking notes: we acquire the scheduler lock once at the beginning
- of the scheduler loop, and release it when
-
- * running a thread, or
- * waiting for work, or
- * waiting for a GC to complete.
-
GRAN version:
In a GranSim setup this loop iterates over the global event queue.
This revolves around the global event queue, which determines what
This is not the ugliest code you could imagine, but it's bloody close.
------------------------------------------------------------------------ */
-static void
-schedule( StgMainThread *mainThread USED_WHEN_RTS_SUPPORTS_THREADS,
- Capability *initialCapability )
+
+static Capability *
+schedule (Capability *initialCapability, Task *task)
{
StgTSO *t;
Capability *cap;
StgThreadReturnCode ret;
#if defined(GRAN)
rtsEvent *event;
-#elif defined(PAR)
- StgSparkPool *pool;
- rtsSpark spark;
+#elif defined(PARALLEL_HASKELL)
StgTSO *tso;
GlobalTaskId pe;
rtsBool receivedFinish = rtsFalse;
nat tp_size, sp_size; // stats only
# endif
#endif
- rtsBool was_interrupted = rtsFalse;
- StgTSOWhatNext prev_what_next;
+ nat prev_what_next;
+ rtsBool ready_to_gc;
+#if defined(THREADED_RTS)
+ rtsBool first = rtsTrue;
+#endif
- // Pre-condition: sched_mutex is held.
- // We might have a capability, passed in as initialCapability.
cap = initialCapability;
-#if defined(RTS_SUPPORTS_THREADS)
- //
- // in the threaded case, the capability is either passed in via the
- // initialCapability parameter, or initialized inside the scheduler
- // loop
- //
+ // Pre-condition: this task owns initialCapability.
+ // The sched_mutex is *NOT* held
+ // NB. on return, we still hold a capability.
+
IF_DEBUG(scheduler,
- sched_belch("### NEW SCHEDULER LOOP (main thr: %p, cap: %p)",
- mainThread, initialCapability);
+ sched_belch("### NEW SCHEDULER LOOP (task: %p, cap: %p)",
+ task, initialCapability);
);
+
+ schedulePreLoop();
+
+ // -----------------------------------------------------------
+ // Scheduler loop starts here:
+
+#if defined(PARALLEL_HASKELL)
+#define TERMINATION_CONDITION (!receivedFinish)
+#elif defined(GRAN)
+#define TERMINATION_CONDITION ((event = get_next_event()) != (rtsEvent*)NULL)
#else
- // simply initialise it in the non-threaded case
- grabCapability(&cap);
+#define TERMINATION_CONDITION rtsTrue
#endif
+ while (TERMINATION_CONDITION) {
+
#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);
+ /* Choose the processor with the next event */
+ CurrentProc = event->proc;
+ CurrentTSO = event->tso;
+#endif
- IF_DEBUG(gran,
- fprintf(stderr, "GRAN: Init CurrentTSO (in schedule) = %p\n", CurrentTSO);
- G_TSO(CurrentTSO, 5));
+#if defined(THREADED_RTS)
+ if (first) {
+ // don't yield the first time, we want a chance to run this
+ // thread for a bit, even if there are others banging at the
+ // door.
+ first = rtsFalse;
+ ASSERT_FULL_CAPABILITY_INVARIANTS(cap,task);
+ } else {
+ // Yield the capability to higher-priority tasks if necessary.
+ yieldCapability(&cap, task);
+ }
+#endif
+
+#ifdef SMP
+ schedulePushWork(cap,task);
+#endif
- if (RtsFlags.GranFlags.Light) {
- /* Save current time; GranSim Light only */
- CurrentTSO->gran.clock = CurrentTime[CurrentProc];
- }
+ // Check whether we have re-entered the RTS from Haskell without
+ // going via suspendThread()/resumeThread (i.e. a 'safe' foreign
+ // call).
+ if (cap->in_haskell) {
+ errorBelch("schedule: re-entered unsafely.\n"
+ " Perhaps a 'foreign import unsafe' should be 'safe'?");
+ stg_exit(EXIT_FAILURE);
+ }
- event = get_next_event();
+ //
+ // 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) {
+ deleteRunQueue(cap);
+#if defined(SMP)
+ discardSparksCap(cap);
+#endif
+ if (shutting_down_scheduler) {
+ IF_DEBUG(scheduler, sched_belch("shutting down"));
+ // If we are a worker, just exit. If we're a bound thread
+ // then we will exit below when we've removed our TSO from
+ // the run queue.
+ if (task->tso == NULL && emptyRunQueue(cap)) {
+ return cap;
+ }
+ } else {
+ IF_DEBUG(scheduler, sched_belch("interrupted"));
+ }
+ }
- while (event!=(rtsEvent*)NULL) {
- /* Choose the processor with the next event */
- CurrentProc = event->proc;
- CurrentTSO = event->tso;
+#if defined(SMP)
+ // If the run queue is empty, take a spark and turn it into a thread.
+ {
+ if (emptyRunQueue(cap)) {
+ StgClosure *spark;
+ spark = findSpark(cap);
+ if (spark != NULL) {
+ IF_DEBUG(scheduler,
+ sched_belch("turning spark of closure %p into a thread",
+ (StgClosure *)spark));
+ createSparkThread(cap,spark);
+ }
+ }
+ }
+#endif // SMP
-#elif defined(PAR)
+ scheduleStartSignalHandlers(cap);
- while (!receivedFinish) { /* set by processMessages */
- /* when receiving PP_FINISH message */
+ // Only check the black holes here if we've nothing else to do.
+ // During normal execution, the black hole list only gets checked
+ // at GC time, to avoid repeatedly traversing this possibly long
+ // list each time around the scheduler.
+ if (emptyRunQueue(cap)) { scheduleCheckBlackHoles(cap); }
-#else // everything except GRAN and PAR
+ scheduleCheckBlockedThreads(cap);
- while (1) {
+ scheduleDetectDeadlock(cap,task);
+ // Normally, the only way we can get here with no threads to
+ // run is if a keyboard interrupt received during
+ // scheduleCheckBlockedThreads() or scheduleDetectDeadlock().
+ // Additionally, it is not fatal for the
+ // threaded RTS to reach here with no threads to run.
+ //
+ // win32: might be here due to awaitEvent() being abandoned
+ // as a result of a console event having been delivered.
+ if ( emptyRunQueue(cap) ) {
+#if !defined(THREADED_RTS) && !defined(mingw32_HOST_OS)
+ ASSERT(interrupted);
#endif
+ continue; // nothing to do
+ }
- IF_DEBUG(scheduler, printAllThreads());
+#if defined(PARALLEL_HASKELL)
+ scheduleSendPendingMessages();
+ if (emptyRunQueue(cap) && scheduleActivateSpark())
+ continue;
-#if defined(RTS_SUPPORTS_THREADS)
- // Yield the capability to higher-priority tasks if necessary.
- //
- if (cap != NULL) {
- yieldCapability(&cap);
- }
+#if defined(SPARKS)
+ ASSERT(next_fish_to_send_at==0); // i.e. no delayed fishes left!
+#endif
- // 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);
- }
+ /* If we still have no work we need to send a FISH to get a spark
+ from another PE */
+ if (emptyRunQueue(cap)) {
+ if (!scheduleGetRemoteWork(&receivedFinish)) continue;
+ ASSERT(rtsFalse); // should not happen at the moment
+ }
+ // from here: non-empty run queue.
+ // TODO: merge above case with this, only one call processMessages() !
+ if (PacketsWaiting()) { /* process incoming messages, if
+ any pending... only in else
+ because getRemoteWork waits for
+ messages as well */
+ receivedFinish = processMessages();
+ }
+#endif
- // We now have a capability...
+#if defined(GRAN)
+ scheduleProcessEvent(event);
#endif
+ //
+ // Get a thread to run
//
- // 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);
- RELEASE_LOCK(&sched_mutex);
- shutdownHaskellAndExit(EXIT_SUCCESS);
+ t = popRunQueue(cap);
+
+#if defined(GRAN) || defined(PAR)
+ scheduleGranParReport(); // some kind of debuging output
#else
- deleteAllThreads();
+ // 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_USER_SIGNALS)
- // check for signals each time around the scheduler
- if (signals_pending()) {
- RELEASE_LOCK(&sched_mutex); /* ToDo: kill */
- startSignalHandlers();
- ACQUIRE_LOCK(&sched_mutex);
+#if defined(THREADED_RTS)
+ // Check whether we can run this thread in the current task.
+ // If not, we have to pass our capability to the right task.
+ {
+ Task *bound = t->bound;
+
+ if (bound) {
+ if (bound == task) {
+ IF_DEBUG(scheduler,
+ sched_belch("### Running thread %d in bound thread",
+ t->id));
+ // yes, the Haskell thread is bound to the current native thread
+ } else {
+ IF_DEBUG(scheduler,
+ sched_belch("### thread %d bound to another OS thread",
+ t->id));
+ // no, bound to a different Haskell thread: pass to that thread
+ pushOnRunQueue(cap,t);
+ continue;
+ }
+ } else {
+ // The thread we want to run is unbound.
+ if (task->tso) {
+ IF_DEBUG(scheduler,
+ sched_belch("### this OS thread cannot run thread %d", t->id));
+ // no, the current native thread is bound to a different
+ // Haskell thread, so pass it to any worker thread
+ pushOnRunQueue(cap,t);
+ continue;
+ }
+ }
}
#endif
- //
- // 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)
- || EMPTY_RUN_QUEUE()
-#endif
- )
- {
- awaitEvent( EMPTY_RUN_QUEUE() );
+ cap->r.rCurrentTSO = t;
+
+ /* context switches are initiated by the timer signal, unless
+ * the user specified "context switch as often as possible", with
+ * +RTS -C0
+ */
+ if (RtsFlags.ConcFlags.ctxtSwitchTicks == 0
+ && !emptyThreadQueues(cap)) {
+ context_switch = 1;
}
- // we can be interrupted while waiting for I/O...
- if (interrupted) continue;
+
+run_thread:
- /*
- * 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_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 about to be send BlockedOnDeadMVar. Any threads
- // thus released will be immediately runnable.
- GarbageCollect(GetRoots,rtsTrue);
+ IF_DEBUG(scheduler, sched_belch("-->> running thread %ld %s ...",
+ (long)t->id, whatNext_strs[t->what_next]));
- if ( !EMPTY_RUN_QUEUE() ) { goto not_deadlocked; }
+#if defined(PROFILING)
+ startHeapProfTimer();
+#endif
- IF_DEBUG(scheduler,
- sched_belch("still deadlocked, checking for black holes..."));
- detectBlackHoles();
+ // ----------------------------------------------------------------------
+ // Run the current thread
- if ( !EMPTY_RUN_QUEUE() ) { goto not_deadlocked; }
+ prev_what_next = t->what_next;
-#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 ( anyUserHandlers() ) {
- IF_DEBUG(scheduler,
- sched_belch("still deadlocked, waiting for signals..."));
+ errno = t->saved_errno;
+ cap->in_haskell = rtsTrue;
- awaitUserSignals();
+ recent_activity = ACTIVITY_YES;
+
+ switch (prev_what_next) {
+
+ case ThreadKilled:
+ case ThreadComplete:
+ /* Thread already finished, return to scheduler. */
+ ret = ThreadFinished;
+ break;
+
+ case ThreadRunGHC:
+ {
+ StgRegTable *r;
+ r = StgRun((StgFunPtr) stg_returnToStackTop, &cap->r);
+ cap = regTableToCapability(r);
+ ret = r->rRet;
+ break;
+ }
+
+ case ThreadInterpret:
+ cap = interpretBCO(cap);
+ ret = cap->r.rRet;
+ break;
+
+ default:
+ barf("schedule: invalid what_next field");
+ }
- // we might be interrupted...
- if (interrupted) { continue; }
+ cap->in_haskell = rtsFalse;
- if (signals_pending()) {
- RELEASE_LOCK(&sched_mutex);
- startSignalHandlers();
- ACQUIRE_LOCK(&sched_mutex);
- }
- ASSERT(!EMPTY_RUN_QUEUE());
- goto not_deadlocked;
- }
-#endif
+ // 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;
- /* Probably a real deadlock. Send the current main thread the
- * Deadlock exception (or in the SMP build, send *all* main
- * threads the deadlock exception, since none of them can make
- * progress).
- */
- {
- StgMainThread *m;
- m = main_threads;
- switch (m->tso->why_blocked) {
- case BlockedOnBlackHole:
- case BlockedOnException:
- case BlockedOnMVar:
- raiseAsync(m->tso, (StgClosure *)NonTermination_closure);
- break;
- default:
- barf("deadlock: main thread blocked in a strange way");
- }
- }
+ // We have run some Haskell code: there might be blackhole-blocked
+ // threads to wake up now.
+ // Lock-free test here should be ok, we're just setting a flag.
+ if ( blackhole_queue != END_TSO_QUEUE ) {
+ blackholes_need_checking = rtsTrue;
}
- 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
+
+ // And save the current errno in this thread.
+ // XXX: possibly bogus for SMP because this thread might already
+ // be running again, see code below.
+ t->saved_errno = errno;
-#if defined(RTS_SUPPORTS_THREADS)
- if ( EMPTY_RUN_QUEUE() ) {
- continue; // nothing to do
+#ifdef SMP
+ // If ret is ThreadBlocked, and this Task is bound to the TSO that
+ // blocked, we are in limbo - the TSO is now owned by whatever it
+ // is blocked on, and may in fact already have been woken up,
+ // perhaps even on a different Capability. It may be the case
+ // that task->cap != cap. We better yield this Capability
+ // immediately and return to normaility.
+ if (ret == ThreadBlocked) {
+ IF_DEBUG(scheduler,
+ sched_belch("--<< thread %d (%s) stopped: blocked\n",
+ t->id, whatNext_strs[t->what_next]));
+ continue;
}
#endif
-#if defined(GRAN)
- if (RtsFlags.GranFlags.Light)
- GranSimLight_enter_system(event, &ActiveTSO); // adjust ActiveTSO etc
+ ASSERT_FULL_CAPABILITY_INVARIANTS(cap,task);
- /* adjust time based on time-stamp */
- if (event->time > CurrentTime[CurrentProc] &&
- event->evttype != ContinueThread)
- CurrentTime[CurrentProc] = event->time;
+ // ----------------------------------------------------------------------
- /* Deal with the idle PEs (may issue FindWork or MoveSpark events) */
- if (!RtsFlags.GranFlags.Light)
- handleIdlePEs();
+ // Costs for the scheduler are assigned to CCS_SYSTEM
+#if defined(PROFILING)
+ stopHeapProfTimer();
+ CCCS = CCS_SYSTEM;
+#endif
+
+#if defined(THREADED_RTS)
+ IF_DEBUG(scheduler,debugBelch("sched (task %p): ", (void *)(unsigned long)(unsigned int)osThreadId()););
+#elif !defined(GRAN) && !defined(PARALLEL_HASKELL)
+ IF_DEBUG(scheduler,debugBelch("sched: "););
+#endif
+
+ schedulePostRunThread();
- IF_DEBUG(gran, fprintf(stderr, "GRAN: switch by event-type\n"));
+ ready_to_gc = rtsFalse;
- /* main event dispatcher in GranSim */
- switch (event->evttype) {
- /* Should just be continuing execution */
- case ContinueThread:
- IF_DEBUG(gran, fprintf(stderr, "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]",
- CurrentTSO->id, CurrentTSO, CurrentProc);
- goto next_thread;
+ switch (ret) {
+ case HeapOverflow:
+ ready_to_gc = scheduleHandleHeapOverflow(cap,t);
+ break;
+
+ case StackOverflow:
+ scheduleHandleStackOverflow(cap,task,t);
+ break;
+
+ case ThreadYielding:
+ if (scheduleHandleYield(cap, t, prev_what_next)) {
+ // shortcut for switching between compiler/interpreter:
+ goto run_thread;
+ }
+ break;
+
+ case ThreadBlocked:
+ scheduleHandleThreadBlocked(t);
+ break;
+
+ case ThreadFinished:
+ if (scheduleHandleThreadFinished(cap, task, t)) return cap;
+ ASSERT_FULL_CAPABILITY_INVARIANTS(cap,task);
+ break;
+
+ default:
+ barf("schedule: invalid thread return code %d", (int)ret);
+ }
+
+ if (scheduleDoHeapProfile(ready_to_gc)) { ready_to_gc = rtsFalse; }
+ if (ready_to_gc) { scheduleDoGC(cap,task,rtsFalse); }
+ } /* end of while() */
+
+ IF_PAR_DEBUG(verbose,
+ debugBelch("== Leaving schedule() after having received Finish\n"));
+}
+
+/* ----------------------------------------------------------------------------
+ * Setting up the scheduler loop
+ * ------------------------------------------------------------------------- */
+
+static void
+schedulePreLoop(void)
+{
+#if defined(GRAN)
+ /* set up first event to get things going */
+ /* ToDo: assign costs for system setup and init MainTSO ! */
+ new_event(CurrentProc, CurrentProc, CurrentTime[CurrentProc],
+ ContinueThread,
+ CurrentTSO, (StgClosure*)NULL, (rtsSpark*)NULL);
+
+ IF_DEBUG(gran,
+ debugBelch("GRAN: Init CurrentTSO (in schedule) = %p\n",
+ CurrentTSO);
+ G_TSO(CurrentTSO, 5));
+
+ if (RtsFlags.GranFlags.Light) {
+ /* Save current time; GranSim Light only */
+ CurrentTSO->gran.clock = CurrentTime[CurrentProc];
+ }
+#endif
+}
+
+/* -----------------------------------------------------------------------------
+ * schedulePushWork()
+ *
+ * Push work to other Capabilities if we have some.
+ * -------------------------------------------------------------------------- */
+
+#ifdef SMP
+static void
+schedulePushWork(Capability *cap USED_IF_SMP,
+ Task *task USED_IF_SMP)
+{
+ Capability *free_caps[n_capabilities], *cap0;
+ nat i, n_free_caps;
+
+ // Check whether we have more threads on our run queue, or sparks
+ // in our pool, that we could hand to another Capability.
+ if ((emptyRunQueue(cap) || cap->run_queue_hd->link == END_TSO_QUEUE)
+ && sparkPoolSizeCap(cap) < 2) {
+ return;
+ }
+
+ // First grab as many free Capabilities as we can.
+ for (i=0, n_free_caps=0; i < n_capabilities; i++) {
+ cap0 = &capabilities[i];
+ if (cap != cap0 && tryGrabCapability(cap0,task)) {
+ if (!emptyRunQueue(cap0) || cap->returning_tasks_hd != NULL) {
+ // it already has some work, we just grabbed it at
+ // the wrong moment. Or maybe it's deadlocked!
+ releaseCapability(cap0);
+ } else {
+ free_caps[n_free_caps++] = cap0;
+ }
+ }
+ }
+
+ // we now have n_free_caps free capabilities stashed in
+ // free_caps[]. Share our run queue equally with them. This is
+ // probably the simplest thing we could do; improvements we might
+ // want to do include:
+ //
+ // - giving high priority to moving relatively new threads, on
+ // the gournds that they haven't had time to build up a
+ // working set in the cache on this CPU/Capability.
+ //
+ // - giving low priority to moving long-lived threads
+
+ if (n_free_caps > 0) {
+ StgTSO *prev, *t, *next;
+ rtsBool pushed_to_all;
+
+ IF_DEBUG(scheduler, sched_belch("excess threads on run queue and %d free capabilities, sharing...", n_free_caps));
+
+ i = 0;
+ pushed_to_all = rtsFalse;
+
+ if (cap->run_queue_hd != END_TSO_QUEUE) {
+ prev = cap->run_queue_hd;
+ t = prev->link;
+ prev->link = END_TSO_QUEUE;
+ for (; t != END_TSO_QUEUE; t = next) {
+ next = t->link;
+ t->link = END_TSO_QUEUE;
+ if (t->what_next == ThreadRelocated
+ || t->bound == task) { // don't move my bound thread
+ prev->link = t;
+ prev = t;
+ } else if (i == n_free_caps) {
+ pushed_to_all = rtsTrue;
+ i = 0;
+ // keep one for us
+ prev->link = t;
+ prev = t;
+ } else {
+ IF_DEBUG(scheduler, sched_belch("pushing thread %d to capability %d", t->id, free_caps[i]->no));
+ appendToRunQueue(free_caps[i],t);
+ if (t->bound) { t->bound->cap = free_caps[i]; }
+ i++;
+ }
+ }
+ cap->run_queue_tl = prev;
+ }
+
+ // If there are some free capabilities that we didn't push any
+ // threads to, then try to push a spark to each one.
+ if (!pushed_to_all) {
+ StgClosure *spark;
+ // i is the next free capability to push to
+ for (; i < n_free_caps; i++) {
+ if (emptySparkPoolCap(free_caps[i])) {
+ spark = findSpark(cap);
+ if (spark != NULL) {
+ IF_DEBUG(scheduler, sched_belch("pushing spark %p to capability %d", spark, free_caps[i]->no));
+ newSpark(&(free_caps[i]->r), spark);
+ }
+ }
+ }
+ }
+
+ // release the capabilities
+ for (i = 0; i < n_free_caps; i++) {
+ task->cap = free_caps[i];
+ releaseCapability(free_caps[i]);
+ }
+ }
+ task->cap = cap; // reset to point to our Capability.
+}
+#endif
+
+/* ----------------------------------------------------------------------------
+ * Start any pending signal handlers
+ * ------------------------------------------------------------------------- */
+
+#if defined(RTS_USER_SIGNALS) && (!defined(THREADED_RTS) || defined(mingw32_HOST_OS))
+static void
+scheduleStartSignalHandlers(Capability *cap)
+{
+ if (signals_pending()) { // safe outside the lock
+ startSignalHandlers(cap);
+ }
+}
+#else
+static void
+scheduleStartSignalHandlers(Capability *cap STG_UNUSED)
+{
+}
+#endif
+
+/* ----------------------------------------------------------------------------
+ * Check for blocked threads that can be woken up.
+ * ------------------------------------------------------------------------- */
+
+static void
+scheduleCheckBlockedThreads(Capability *cap USED_IF_NOT_THREADS)
+{
+#if !defined(THREADED_RTS)
+ //
+ // Check whether any waiting threads need to be woken up. If the
+ // run queue is empty, and there are no other tasks running, we
+ // can wait indefinitely for something to happen.
+ //
+ if ( !emptyQueue(blocked_queue_hd) || !emptyQueue(sleeping_queue) )
+ {
+ awaitEvent( emptyRunQueue(cap) && !blackholes_need_checking );
+ }
+#endif
+}
+
+
+/* ----------------------------------------------------------------------------
+ * Check for threads blocked on BLACKHOLEs that can be woken up
+ * ------------------------------------------------------------------------- */
+static void
+scheduleCheckBlackHoles (Capability *cap)
+{
+ if ( blackholes_need_checking ) // check without the lock first
+ {
+ ACQUIRE_LOCK(&sched_mutex);
+ if ( blackholes_need_checking ) {
+ checkBlackHoles(cap);
+ blackholes_need_checking = rtsFalse;
+ }
+ RELEASE_LOCK(&sched_mutex);
+ }
+}
+
+/* ----------------------------------------------------------------------------
+ * Detect deadlock conditions and attempt to resolve them.
+ * ------------------------------------------------------------------------- */
+
+static void
+scheduleDetectDeadlock (Capability *cap, Task *task)
+{
+
+#if defined(PARALLEL_HASKELL)
+ // ToDo: add deadlock detection in GUM (similar to 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 ( emptyThreadQueues(cap) )
+ {
+#if defined(THREADED_RTS)
+ /*
+ * In the threaded RTS, we only check for deadlock if there
+ * has been no activity in a complete timeslice. This means
+ * we won't eagerly start a full GC just because we don't have
+ * any threads to run currently.
+ */
+ if (recent_activity != ACTIVITY_INACTIVE) return;
+#endif
+
+ IF_DEBUG(scheduler, sched_belch("deadlocked, forcing major GC..."));
+
+ // Garbage collection can release some new threads due to
+ // either (a) finalizers or (b) threads resurrected because
+ // they are unreachable and will therefore be sent an
+ // exception. Any threads thus released will be immediately
+ // runnable.
+ scheduleDoGC( cap, task, rtsTrue/*force major GC*/ );
+ recent_activity = ACTIVITY_DONE_GC;
+
+ if ( !emptyRunQueue(cap) ) return;
+
+#if defined(RTS_USER_SIGNALS) && (!defined(THREADED_RTS) || defined(mingw32_HOST_OS))
+ /* If we have user-installed signal handlers, then wait
+ * for signals to arrive rather then bombing out with a
+ * deadlock.
+ */
+ if ( anyUserHandlers() ) {
+ IF_DEBUG(scheduler,
+ sched_belch("still deadlocked, waiting for signals..."));
+
+ awaitUserSignals();
+
+ if (signals_pending()) {
+ startSignalHandlers(cap);
+ }
+
+ // either we have threads to run, or we were interrupted:
+ ASSERT(!emptyRunQueue(cap) || interrupted);
+ }
+#endif
+
+#if !defined(THREADED_RTS)
+ /* Probably a real deadlock. Send the current main thread the
+ * Deadlock exception.
+ */
+ if (task->tso) {
+ switch (task->tso->why_blocked) {
+ case BlockedOnSTM:
+ case BlockedOnBlackHole:
+ case BlockedOnException:
+ case BlockedOnMVar:
+ raiseAsync(cap, task->tso, (StgClosure *)NonTermination_closure);
+ return;
+ default:
+ barf("deadlock: main thread blocked in a strange way");
+ }
+ }
+ return;
+#endif
+ }
+}
+
+/* ----------------------------------------------------------------------------
+ * Process an event (GRAN only)
+ * ------------------------------------------------------------------------- */
+
+#if defined(GRAN)
+static StgTSO *
+scheduleProcessEvent(rtsEvent *event)
+{
+ StgTSO *t;
+
+ if (RtsFlags.GranFlags.Light)
+ GranSimLight_enter_system(event, &ActiveTSO); // adjust ActiveTSO etc
+
+ /* adjust time based on time-stamp */
+ if (event->time > CurrentTime[CurrentProc] &&
+ event->evttype != ContinueThread)
+ CurrentTime[CurrentProc] = event->time;
+
+ /* Deal with the idle PEs (may issue FindWork or MoveSpark events) */
+ if (!RtsFlags.GranFlags.Light)
+ handleIdlePEs();
+
+ IF_DEBUG(gran, 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, 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) {
+ 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;
POP_RUN_QUEUE(t); // take_off_run_queue(t);
IF_DEBUG(gran,
- fprintf(stderr, "GRAN: About to run current thread, which is\n");
+ debugBelch("GRAN: About to run current thread, which is\n");
G_TSO(t,5));
context_switch = 0; // turned on via GranYield, checking events and time slice
DumpGranEvent(GR_SCHEDULE, t));
procStatus[CurrentProc] = Busy;
+}
+#endif // GRAN
-#elif defined(PAR)
+/* ----------------------------------------------------------------------------
+ * Send pending messages (PARALLEL_HASKELL only)
+ * ------------------------------------------------------------------------- */
+
+#if defined(PARALLEL_HASKELL)
+static StgTSO *
+scheduleSendPendingMessages(void)
+{
+ StgSparkPool *pool;
+ rtsSpark spark;
+ StgTSO *t;
+
+# if defined(PAR) // global Mem.Mgmt., omit for now
if (PendingFetches != END_BF_QUEUE) {
processFetches();
}
+# endif
+
+ if (RtsFlags.ParFlags.BufferTime) {
+ // if we use message buffering, we must send away all message
+ // packets which have become too old...
+ sendOldBuffers();
+ }
+}
+#endif
+
+/* ----------------------------------------------------------------------------
+ * Activate spark threads (PARALLEL_HASKELL only)
+ * ------------------------------------------------------------------------- */
+
+#if defined(PARALLEL_HASKELL)
+static void
+scheduleActivateSpark(void)
+{
+#if defined(SPARKS)
+ ASSERT(emptyRunQueue());
+/* We get here if the run queue is empty and want some work.
+ We try to turn a spark into a thread, and add it to the run queue,
+ from where it will be picked up in the next iteration of the scheduler
+ loop.
+*/
- /* ToDo: phps merge with spark activation above */
- /* check whether we have local work and send requests if we have none */
- if (EMPTY_RUN_QUEUE()) { /* no runnable threads */
/* :-[ no local threads => look out for local sparks */
/* the spark pool for the current PE */
- pool = &(MainRegTable.rSparks); // generalise to cap = &MainRegTable
+ pool = &(cap.r.rSparks); // JB: cap = (old) MainCap
if (advisory_thread_count < RtsFlags.ParFlags.maxThreads &&
pool->hd < pool->tl) {
/*
* thread...
*/
- spark = findSpark(rtsFalse); /* get a spark */
- if (spark != (rtsSpark) NULL) {
- tso = activateSpark(spark); /* turn the spark into a thread */
- IF_PAR_DEBUG(schedule,
- belch("==== schedule: Created TSO %d (%p); %d threads active",
- tso->id, tso, advisory_thread_count));
-
- if (tso==END_TSO_QUEUE) { /* failed to activate spark->back to loop */
- belch("==^^ failed to activate spark");
- goto next_thread;
- } /* otherwise fall through & pick-up new tso */
- } else {
- IF_PAR_DEBUG(verbose,
- belch("==^^ no local sparks (spark pool contains only NFs: %d)",
- spark_queue_len(pool)));
- goto next_thread;
+ spark = findSpark(rtsFalse); /* get a spark */
+ if (spark != (rtsSpark) NULL) {
+ tso = createThreadFromSpark(spark); /* turn the spark into a thread */
+ IF_PAR_DEBUG(fish, // schedule,
+ debugBelch("==== schedule: Created TSO %d (%p); %d threads active\n",
+ tso->id, tso, advisory_thread_count));
+
+ if (tso==END_TSO_QUEUE) { /* failed to activate spark->back to loop */
+ IF_PAR_DEBUG(fish, // schedule,
+ debugBelch("==^^ failed to create thread from spark @ %lx\n",
+ spark));
+ return rtsFalse; /* failed to generate a thread */
+ } /* otherwise fall through & pick-up new tso */
+ } else {
+ IF_PAR_DEBUG(fish, // schedule,
+ debugBelch("==^^ no local sparks (spark pool contains only NFs: %d)\n",
+ spark_queue_len(pool)));
+ return rtsFalse; /* failed to generate a thread */
+ }
+ return rtsTrue; /* success in generating a thread */
+ } else { /* no more threads permitted or pool empty */
+ return rtsFalse; /* failed to generateThread */
+ }
+#else
+ tso = NULL; // avoid compiler warning only
+ return rtsFalse; /* dummy in non-PAR setup */
+#endif // SPARKS
+}
+#endif // PARALLEL_HASKELL
+
+/* ----------------------------------------------------------------------------
+ * Get work from a remote node (PARALLEL_HASKELL only)
+ * ------------------------------------------------------------------------- */
+
+#if defined(PARALLEL_HASKELL)
+static rtsBool
+scheduleGetRemoteWork(rtsBool *receivedFinish)
+{
+ ASSERT(emptyRunQueue());
+
+ if (RtsFlags.ParFlags.BufferTime) {
+ IF_PAR_DEBUG(verbose,
+ debugBelch("...send all pending data,"));
+ {
+ nat i;
+ for (i=1; i<=nPEs; i++)
+ sendImmediately(i); // send all messages away immediately
}
- }
+ }
+# ifndef SPARKS
+ //++EDEN++ idle() , i.e. send all buffers, wait for work
+ // suppress fishing in EDEN... just look for incoming messages
+ // (blocking receive)
+ IF_PAR_DEBUG(verbose,
+ debugBelch("...wait for incoming messages...\n"));
+ *receivedFinish = processMessages(); // blocking receive...
+
+ // and reenter scheduling loop after having received something
+ // (return rtsFalse below)
+
+# else /* activate SPARKS machinery */
+/* We get here, if we have no work, tried to activate a local spark, but still
+ have no work. We try to get a remote spark, by sending a FISH message.
+ Thread migration should be added here, and triggered when a sequence of
+ fishes returns without work. */
+ delay = (RtsFlags.ParFlags.fishDelay!=0ll ? RtsFlags.ParFlags.fishDelay : 0ll);
- /* If we still have no work we need to send a FISH to get a spark
- from another PE
- */
- if (EMPTY_RUN_QUEUE()) {
/* =8-[ no local sparks => look for work on other PEs */
/*
* We really have absolutely no work. Send out a fish
* we're hoping to see. (Of course, we still have to
* respond to other types of messages.)
*/
- TIME now = msTime() /*CURRENT_TIME*/;
+ rtsTime now = msTime() /*CURRENT_TIME*/;
IF_PAR_DEBUG(verbose,
- belch("-- now=%ld", now));
- IF_PAR_DEBUG(verbose,
- if (outstandingFishes < RtsFlags.ParFlags.maxFishes &&
- (last_fish_arrived_at!=0 &&
- last_fish_arrived_at+RtsFlags.ParFlags.fishDelay > now)) {
- belch("--$$ delaying FISH until %ld (last fish %ld, delay %ld, now %ld)",
- last_fish_arrived_at+RtsFlags.ParFlags.fishDelay,
- last_fish_arrived_at,
- RtsFlags.ParFlags.fishDelay, now);
- });
-
+ debugBelch("-- now=%ld\n", now));
+ IF_PAR_DEBUG(fish, // verbose,
+ if (outstandingFishes < RtsFlags.ParFlags.maxFishes &&
+ (last_fish_arrived_at!=0 &&
+ last_fish_arrived_at+delay > now)) {
+ debugBelch("--$$ <%llu> delaying FISH until %llu (last fish %llu, delay %llu)\n",
+ now, last_fish_arrived_at+delay,
+ last_fish_arrived_at,
+ delay);
+ });
+
if (outstandingFishes < RtsFlags.ParFlags.maxFishes &&
- (last_fish_arrived_at==0 ||
- (last_fish_arrived_at+RtsFlags.ParFlags.fishDelay <= now))) {
- /* outstandingFishes is set in sendFish, processFish;
- avoid flooding system with fishes via delay */
- pe = choosePE();
- sendFish(pe, mytid, NEW_FISH_AGE, NEW_FISH_HISTORY,
- NEW_FISH_HUNGER);
-
- // Global statistics: count no. of fishes
- if (RtsFlags.ParFlags.ParStats.Global &&
- RtsFlags.GcFlags.giveStats > NO_GC_STATS) {
- globalParStats.tot_fish_mess++;
- }
- }
-
- receivedFinish = processMessages();
- goto next_thread;
+ advisory_thread_count < RtsFlags.ParFlags.maxThreads) { // send a FISH, but when?
+ if (last_fish_arrived_at==0 ||
+ (last_fish_arrived_at+delay <= now)) { // send FISH now!
+ /* outstandingFishes is set in sendFish, processFish;
+ avoid flooding system with fishes via delay */
+ next_fish_to_send_at = 0;
+ } else {
+ /* ToDo: this should be done in the main scheduling loop to avoid the
+ busy wait here; not so bad if fish delay is very small */
+ int iq = 0; // DEBUGGING -- HWL
+ next_fish_to_send_at = last_fish_arrived_at+delay; // remember when to send
+ /* send a fish when ready, but process messages that arrive in the meantime */
+ do {
+ if (PacketsWaiting()) {
+ iq++; // DEBUGGING
+ *receivedFinish = processMessages();
}
- } else if (PacketsWaiting()) { /* Look for incoming messages */
- receivedFinish = processMessages();
- }
+ now = msTime();
+ } while (!*receivedFinish || now<next_fish_to_send_at);
+ // JB: This means the fish could become obsolete, if we receive
+ // work. Better check for work again?
+ // last line: while (!receivedFinish || !haveWork || now<...)
+ // next line: if (receivedFinish || haveWork )
+
+ if (*receivedFinish) // no need to send a FISH if we are finishing anyway
+ return rtsFalse; // NB: this will leave scheduler loop
+ // immediately after return!
+
+ IF_PAR_DEBUG(fish, // verbose,
+ debugBelch("--$$ <%llu> sent delayed fish (%d processMessages); active/total threads=%d/%d\n",now,iq,run_queue_len(),advisory_thread_count));
+
+ }
- /* Now we are sure that we have some work available */
- ASSERT(run_queue_hd != END_TSO_QUEUE);
+ // JB: IMHO, this should all be hidden inside sendFish(...)
+ /* pe = choosePE();
+ sendFish(pe, thisPE, NEW_FISH_AGE, NEW_FISH_HISTORY,
+ NEW_FISH_HUNGER);
- /* Take a thread from the run queue, if we have work */
- POP_RUN_QUEUE(t); // take_off_run_queue(END_TSO_QUEUE);
- IF_DEBUG(sanity,checkTSO(t));
+ // 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);
- POP_RUN_QUEUE(t);
-
- // 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
-#ifdef THREADED_RTS
- {
- 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
-
- 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;
-
-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
-
- /* +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ */
- /* Run the current thread
- */
- prev_what_next = t->what_next;
-
- errno = t->saved_errno;
-
- 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");
- }
-
- // The TSO might have moved, so find the new location:
- t = cap->r.rCurrentTSO;
-
- // And save the current errno in this thread.
- t->saved_errno = errno;
+/* ----------------------------------------------------------------------------
+ * After running a thread...
+ * ------------------------------------------------------------------------- */
- /* +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ */
-
- /* 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,"sched (task %p): ", osThreadId()););
-#elif !defined(GRAN) && !defined(PAR)
- IF_DEBUG(scheduler,fprintf(stderr,"sched: "););
-#endif
-
+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);
- {
- /* 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);
- }
+# endif
break;
case ThreadYielding:
- // 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;
-
-#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.
- */
+# endif
+ break;
+
+ case ThreadBlocked:
+# if defined(GRAN)
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;
- }
+ 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"));
- threadPaused(t);
+ // ??? 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)
+//++PAR++ blockThread() writes the event (change?)
+# endif
+ break;
-#if defined(GRAN)
- ASSERT(!is_on_queue(t,CurrentProc));
+ case ThreadFinished:
+ break;
- IF_DEBUG(sanity,
- //belch("&& Doing sanity check on all ThreadQueues (and their TSOs).");
- checkThreadQsSanity(rtsTrue));
+ default:
+ barf("parGlobalStats: unknown return code");
+ break;
+ }
#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);
+/* -----------------------------------------------------------------------------
+ * Handle a thread that returned to the scheduler with ThreadHeepOverflow
+ * -------------------------------------------------------------------------- */
+
+static rtsBool
+scheduleHandleHeapOverflow( Capability *cap, StgTSO *t )
+{
+ // did the task ask for a large block?
+ if (cap->r.rHpAlloc > BLOCK_SIZE) {
+ // if so, get one and push it on the front of the nursery.
+ bdescr *bd;
+ lnat blocks;
+
+ blocks = (lnat)BLOCK_ROUND_UP(cap->r.rHpAlloc) / BLOCK_SIZE;
+
+ IF_DEBUG(scheduler,
+ debugBelch("--<< thread %ld (%s) stopped: requesting a large block (size %ld)\n",
+ (long)t->id, whatNext_strs[t->what_next], blocks));
+
+ // don't do this if the nursery is (nearly) full, we'll GC first.
+ if (cap->r.rCurrentNursery->link != NULL ||
+ cap->r.rNursery->n_blocks == 1) { // paranoia to prevent infinite loop
+ // if the nursery has only one block.
+
+ ACQUIRE_SM_LOCK
+ bd = allocGroup( blocks );
+ RELEASE_SM_LOCK
+ cap->r.rNursery->n_blocks += blocks;
+
+ // link the new group into the list
+ bd->link = cap->r.rCurrentNursery;
+ bd->u.back = cap->r.rCurrentNursery->u.back;
+ if (cap->r.rCurrentNursery->u.back != NULL) {
+ cap->r.rCurrentNursery->u.back->link = bd;
+ } else {
+#if !defined(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.
+ pushOnRunQueue(cap,t);
+ return rtsFalse; /* not actually GC'ing */
+ }
+ }
+
+ IF_DEBUG(scheduler,
+ debugBelch("--<< thread %ld (%s) stopped: HeapOverflow\n",
+ (long)t->id, whatNext_strs[t->what_next]));
+#if defined(GRAN)
+ ASSERT(!is_on_queue(t,CurrentProc));
+#elif defined(PARALLEL_HASKELL)
+ /* Currently we emit a DESCHEDULE event before GC in GUM.
+ ToDo: either add separate event to distinguish SYSTEM time from rest
+ or just nuke this DESCHEDULE (and the following SCHEDULE) */
+ if (0 && RtsFlags.ParFlags.ParStats.Full) {
+ DumpRawGranEvent(CURRENT_PROC, CURRENT_PROC,
+ GR_DESCHEDULE, t, (StgClosure *)NULL, 0, 0);
+ emitSchedule = rtsTrue;
+ }
+#endif
+
+ pushOnRunQueue(cap,t);
+ return rtsTrue;
+ /* actual GC is done at the end of the while loop in schedule() */
+}
+
+/* -----------------------------------------------------------------------------
+ * Handle a thread that returned to the scheduler with ThreadStackOverflow
+ * -------------------------------------------------------------------------- */
+
+static void
+scheduleHandleStackOverflow (Capability *cap, Task *task, StgTSO *t)
+{
+ IF_DEBUG(scheduler,debugBelch("--<< thread %ld (%s) stopped, StackOverflow\n",
+ (long)t->id, whatNext_strs[t->what_next]));
+ /* just adjust the stack for this thread, then pop it back
+ * on the run queue.
+ */
+ {
+ /* enlarge the stack */
+ StgTSO *new_t = threadStackOverflow(cap, t);
+
+ /* The TSO attached to this Task may have moved, so update the
+ * pointer to it.
+ */
+ if (task->tso == t) {
+ task->tso = new_t;
+ }
+ pushOnRunQueue(cap,new_t);
+ }
+}
+
+/* -----------------------------------------------------------------------------
+ * Handle a thread that returned to the scheduler with ThreadYielding
+ * -------------------------------------------------------------------------- */
+static rtsBool
+scheduleHandleYield( Capability *cap, StgTSO *t, nat prev_what_next )
+{
+ // Reset the context switch flag. We don't do this just before
+ // running the thread, because that would mean we would lose ticks
+ // during GC, which can lead to unfair scheduling (a thread hogs
+ // the CPU because the tick always arrives during GC). This way
+ // penalises threads that do a lot of allocation, but that seems
+ // better than the alternative.
+ context_switch = 0;
+
+ /* put the thread back on the run queue. Then, if we're ready to
+ * GC, check whether this is the last task to stop. If so, wake
+ * up the GC thread. getThread will block during a GC until the
+ * GC is finished.
+ */
+ IF_DEBUG(scheduler,
+ if (t->what_next != prev_what_next) {
+ debugBelch("--<< thread %ld (%s) stopped to switch evaluators\n",
+ (long)t->id, whatNext_strs[t->what_next]);
+ } else {
+ debugBelch("--<< thread %ld (%s) stopped, yielding\n",
+ (long)t->id, whatNext_strs[t->what_next]);
+ }
+ );
+
+ IF_DEBUG(sanity,
+ //debugBelch("&& Doing sanity check on yielding TSO %ld.", t->id);
+ checkTSO(t));
+ ASSERT(t->link == END_TSO_QUEUE);
+
+ // Shortcut if we're just switching evaluators: don't bother
+ // doing stack squeezing (which can be expensive), just run the
+ // thread.
+ if (t->what_next != prev_what_next) {
+ return rtsTrue;
+ }
+
#if defined(GRAN)
- /* 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;
+ ASSERT(!is_on_queue(t,CurrentProc));
+
+ IF_DEBUG(sanity,
+ //debugBelch("&& Doing sanity check on all ThreadQueues (and their TSOs).");
+ checkThreadQsSanity(rtsTrue));
+
+#endif
+
+ addToRunQueue(cap,t);
- case ThreadBlocked:
#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));
+ /* 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;
+}
- // ??? needed; should emit block before
- IF_DEBUG(gran,
- DumpGranEvent(GR_DESCHEDULE, t));
- prune_eventq(t, (StgClosure *)NULL); // prune ContinueThreads for t
- /*
- ngoq Dogh!
+/* -----------------------------------------------------------------------------
+ * Handle a thread that returned to the scheduler with ThreadBlocked
+ * -------------------------------------------------------------------------- */
+
+static void
+scheduleHandleThreadBlocked( StgTSO *t
+#if !defined(GRAN) && !defined(DEBUG)
+ STG_UNUSED
+#endif
+ )
+{
+#if defined(GRAN)
+ IF_DEBUG(scheduler,
+ debugBelch("--<< thread %ld (%p; %s) stopped, blocking on node %p [PE %d] with BQ: \n",
+ t->id, t, whatNext_strs[t->what_next], t->block_info.closure, (t->block_info.closure==(StgClosure*)NULL ? 99 : where_is(t->block_info.closure)));
+ if (t->block_info.closure!=(StgClosure*)NULL) print_bq(t->block_info.closure));
+
+ // ??? needed; should emit block before
+ IF_DEBUG(gran,
+ DumpGranEvent(GR_DESCHEDULE, t));
+ prune_eventq(t, (StgClosure *)NULL); // prune ContinueThreads for t
+ /*
+ ngoq Dogh!
ASSERT(procStatus[CurrentProc]==Busy ||
- ((procStatus[CurrentProc]==Fetching) &&
- (t->block_info.closure!=(StgClosure*)NULL)));
+ ((procStatus[CurrentProc]==Fetching) &&
+ (t->block_info.closure!=(StgClosure*)NULL)));
if (run_queue_hds[CurrentProc] == END_TSO_QUEUE &&
- !(!RtsFlags.GranFlags.DoAsyncFetch &&
- procStatus[CurrentProc]==Fetching))
- procStatus[CurrentProc] = Idle;
- */
+ !(!RtsFlags.GranFlags.DoAsyncFetch &&
+ procStatus[CurrentProc]==Fetching))
+ procStatus[CurrentProc] = Idle;
+ */
#elif defined(PAR)
- IF_DEBUG(scheduler,
- belch("--<< thread %ld (%p; %s) stopped, blocking on node %p with BQ: ",
- t->id, t, whatNext_strs[t->what_next], t->block_info.closure));
- IF_PAR_DEBUG(bq,
-
- if (t->block_info.closure!=(StgClosure*)NULL)
- print_bq(t->block_info.closure));
+ 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 */
- /* Send a fetch (if BlockedOnGA) and dump event to log file */
- blockThread(t);
+ // 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.
- /* whatever we schedule next, we must log that schedule */
- emitSchedule = rtsTrue;
+#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
-#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"));
- fflush(stderr);
-
- /* Only for dumping event to log file
- ToDo: do I need this in GranSim, too?
- blockThread(t);
- */
+ 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
- threadPaused(t);
- break;
+}
+
+/* -----------------------------------------------------------------------------
+ * Handle a thread that returned to the scheduler with ThreadFinished
+ * -------------------------------------------------------------------------- */
+
+static rtsBool
+scheduleHandleThreadFinished (Capability *cap STG_UNUSED, Task *task, StgTSO *t)
+{
+ /* Need to check whether this was a main thread, and if so,
+ * return with the return value.
+ *
+ * We also end up here if the thread kills itself with an
+ * uncaught exception, see Exception.cmm.
+ */
+ IF_DEBUG(scheduler,debugBelch("--++ thread %d (%s) finished\n",
+ t->id, whatNext_strs[t->what_next]));
- 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]));
#if defined(GRAN)
endThread(t, CurrentProc); // clean-up the thread
-#elif defined(PAR)
+#elif defined(PARALLEL_HASKELL)
/* For now all are advisory -- HWL */
//if(t->priority==AdvisoryPriority) ??
- advisory_thread_count--;
+ advisory_thread_count--; // JB: Caution with this counter, buggy!
-# ifdef DIST
+# if defined(DIST)
if(t->dist.priority==RevalPriority)
FinishReval(t);
# endif
-
+
+# if defined(EDENOLD)
+ // the thread could still have an outport... (BUG)
+ if (t->eden.outport != -1) {
+ // delete the outport for the tso which has finished...
+ IF_PAR_DEBUG(eden_ports,
+ debugBelch("WARNING: Scheduler removes outport %d for TSO %d.\n",
+ t->eden.outport, t->id));
+ deleteOPT(t);
+ }
+ // thread still in the process (HEAVY BUG! since outport has just been closed...)
+ if (t->eden.epid != -1) {
+ IF_PAR_DEBUG(eden_ports,
+ debugBelch("WARNING: Scheduler removes TSO %d from process %d .\n",
+ t->id, t->eden.epid));
+ removeTSOfromProcess(t);
+ }
+# endif
+
+# if defined(PAR)
if (RtsFlags.ParFlags.ParStats.Full &&
!RtsFlags.ParFlags.ParStats.Suppressed)
DumpEndEvent(CURRENT_PROC, t, rtsFalse /* not mandatory */);
-#endif
+
+ // 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
+ // Check whether the thread that just completed was a bound
// thread, and if so return with the result.
//
// There is an assumption here that all thread completion goes
// 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
+
+ if (t->bound) {
+
+ if (t->bound != task) {
+#if !defined(THREADED_RTS)
+ // Must be a bound thread that is not the topmost one. Leave
+ // it on the run queue until the stack has unwound to the
+ // point where we can deal with this. Leaving it on the run
+ // queue also ensures that the garbage collector knows about
+ // this thread and its return value (it gets dropped from the
+ // all_threads list so there's no other way to find it).
+ appendToRunQueue(cap,t);
+ return rtsFalse;
#else
- mainThread->tso == t
+ // this cannot happen in the threaded RTS, because a
+ // bound thread can only be run by the appropriate Task.
+ barf("finished bound thread that isn't mine");
#endif
- )
- {
- // We are a bound thread: this must be our thread that just
- // completed.
- ASSERT(mainThread->tso == t);
+ }
+
+ ASSERT(task->tso == t);
if (t->what_next == ThreadComplete) {
- if (mainThread->ret) {
+ if (task->ret) {
// NOTE: return val is tso->sp[1] (see StgStartup.hc)
- *(mainThread->ret) = (StgClosure *)mainThread->tso->sp[1];
+ *(task->ret) = (StgClosure *)task->tso->sp[1];
}
- mainThread->stat = Success;
+ task->stat = Success;
} else {
- if (mainThread->ret) {
- *(mainThread->ret) = NULL;
+ if (task->ret) {
+ *(task->ret) = NULL;
}
- if (was_interrupted) {
- mainThread->stat = Interrupted;
+ if (interrupted) {
+ task->stat = Interrupted;
} else {
- mainThread->stat = Killed;
+ task->stat = Killed;
}
}
#ifdef DEBUG
- removeThreadLabel((StgWord)mainThread->tso->id);
+ removeThreadLabel((StgWord)task->tso->id);
#endif
- if (mainThread->prev == NULL) {
- main_threads = mainThread->link;
- } else {
- mainThread->prev->link = mainThread->link;
- }
- if (mainThread->link != NULL) {
- mainThread->link->prev = NULL;
- }
- releaseCapability(cap);
- return;
+ return rtsTrue; // tells schedule() to return
}
-#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
- break;
+ return rtsFalse;
+}
- default:
- barf("schedule: invalid thread return code %d", (int)ret);
- }
+/* -----------------------------------------------------------------------------
+ * Perform a heap census, if PROFILING
+ * -------------------------------------------------------------------------- */
-#ifdef 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
+ * -------------------------------------------------------------------------- */
- if (ready_to_gc) {
- /* 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 void
+scheduleDoGC( Capability *cap, Task *task USED_IF_SMP, rtsBool force_major )
+{
+ StgTSO *t;
+#ifdef SMP
+ static volatile StgWord waiting_for_gc;
+ rtsBool was_waiting;
+ nat i;
#endif
- GarbageCollect(GetRoots,rtsFalse);
- ready_to_gc = rtsFalse;
-#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 */
+
+#ifdef SMP
+ // In order to GC, there must be no threads running Haskell code.
+ // Therefore, the GC thread needs to hold *all* the capabilities,
+ // and release them after the GC has completed.
+ //
+ // This seems to be the simplest way: previous attempts involved
+ // making all the threads with capabilities give up their
+ // capabilities and sleep except for the *last* one, which
+ // actually did the GC. But it's quite hard to arrange for all
+ // the other tasks to sleep and stay asleep.
+ //
+
+ was_waiting = cas(&waiting_for_gc, 0, 1);
+ if (was_waiting) {
+ do {
+ IF_DEBUG(scheduler, sched_belch("someone else is trying to GC..."));
+ yieldCapability(&cap,task);
+ } while (waiting_for_gc);
+ return;
}
-#if defined(GRAN)
- next_thread:
- IF_GRAN_DEBUG(unused,
- print_eventq(EventHd));
+ for (i=0; i < n_capabilities; i++) {
+ IF_DEBUG(scheduler, sched_belch("ready_to_gc, grabbing all the capabilies (%d/%d)", i, n_capabilities));
+ if (cap != &capabilities[i]) {
+ Capability *pcap = &capabilities[i];
+ // we better hope this task doesn't get migrated to
+ // another Capability while we're waiting for this one.
+ // It won't, because load balancing happens while we have
+ // all the Capabilities, but even so it's a slightly
+ // unsavoury invariant.
+ task->cap = pcap;
+ context_switch = 1;
+ waitForReturnCapability(&pcap, task);
+ if (pcap != &capabilities[i]) {
+ barf("scheduleDoGC: got the wrong capability");
+ }
+ }
+ }
- event = get_next_event();
-#elif defined(PAR)
- next_thread:
- /* ToDo: wait for next message to arrive rather than busy wait */
-#endif /* GRAN */
+ waiting_for_gc = rtsFalse;
+#endif
- } /* end of while(1) */
+ /* Kick any transactions which are invalid back to their
+ * atomically frames. When next scheduled they will try to
+ * commit, this commit will fail and they will retry.
+ */
+ {
+ StgTSO *next;
+
+ for (t = all_threads; t != END_TSO_QUEUE; t = next) {
+ if (t->what_next == ThreadRelocated) {
+ next = t->link;
+ } else {
+ next = t->global_link;
+ if (t -> trec != NO_TREC && t -> why_blocked == NotBlocked) {
+ if (!stmValidateNestOfTransactions (t -> trec)) {
+ IF_DEBUG(stm, sched_belch("trec %p found wasting its time", t));
+
+ // strip the stack back to the
+ // ATOMICALLY_FRAME, aborting the (nested)
+ // transaction, and saving the stack of any
+ // partially-evaluated thunks on the heap.
+ raiseAsync_(cap, t, NULL, rtsTrue, NULL);
+
+#ifdef REG_R1
+ ASSERT(get_itbl((StgClosure *)t->sp)->type == ATOMICALLY_FRAME);
+#endif
+ }
+ }
+ }
+ }
+ }
+
+ // so this happens periodically:
+ scheduleCheckBlackHoles(cap);
+
+ IF_DEBUG(scheduler, printAllThreads());
- IF_PAR_DEBUG(verbose,
- belch("== Leaving schedule() after having received Finish"));
+ /* everybody back, start the GC.
+ * Could do it in this thread, or signal a condition var
+ * to do it in another thread. Either way, we need to
+ * broadcast on gc_pending_cond afterward.
+ */
+#if defined(THREADED_RTS)
+ IF_DEBUG(scheduler,sched_belch("doing GC"));
+#endif
+ GarbageCollect(GetRoots, force_major);
+
+#if defined(SMP)
+ // release our stash of capabilities.
+ for (i = 0; i < n_capabilities; i++) {
+ if (cap != &capabilities[i]) {
+ task->cap = &capabilities[i];
+ releaseCapability(&capabilities[i]);
+ }
+ }
+ task->cap = cap;
+#endif
+
+#if defined(GRAN)
+ /* add a ContinueThread event to continue execution of current thread */
+ new_event(CurrentProc, CurrentProc, CurrentTime[CurrentProc],
+ ContinueThread,
+ t, (StgClosure*)NULL, (rtsSpark*)NULL);
+ IF_GRAN_DEBUG(bq,
+ debugBelch("GRAN: eventq and runnableq after Garbage collection:\n\n");
+ G_EVENTQ(0);
+ G_CURR_THREADQ(0));
+#endif /* GRAN */
}
/* ---------------------------------------------------------------------------
StgBool
rtsSupportsBoundThreads(void)
{
-#ifdef THREADED_RTS
+#if defined(THREADED_RTS)
return rtsTrue;
#else
return rtsFalse;
* ------------------------------------------------------------------------- */
StgBool
-isThreadBound(StgTSO* tso USED_IN_THREADED_RTS)
+isThreadBound(StgTSO* tso USED_IF_THREADS)
{
-#ifdef THREADED_RTS
- return (tso->main != NULL);
+#if defined(THREADED_RTS)
+ return (tso->bound != NULL);
#endif
return rtsFalse;
}
* Singleton fork(). Do not copy any running threads.
* ------------------------------------------------------------------------- */
-#ifndef mingw32_TARGET_OS
+#if !defined(mingw32_HOST_OS) && !defined(SMP)
#define FORKPROCESS_PRIMOP_SUPPORTED
#endif
#ifdef FORKPROCESS_PRIMOP_SUPPORTED
static void
-deleteThreadImmediately(StgTSO *tso);
+deleteThreadImmediately(Capability *cap, StgTSO *tso);
#endif
StgInt
forkProcess(HsStablePtr *entry
)
{
#ifdef FORKPROCESS_PRIMOP_SUPPORTED
- pid_t pid;
- StgTSO* t,*next;
- StgMainThread *m;
- 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;
+ Task *task;
+ pid_t pid;
+ StgTSO* t,*next;
+ Capability *cap;
- } else { /* child */
+ IF_DEBUG(scheduler,sched_belch("forking!"));
+ // ToDo: for SMP, we should probably acquire *all* the capabilities
+ cap = rts_lock();
- // delete all threads
- run_queue_hd = run_queue_tl = END_TSO_QUEUE;
+ pid = fork();
- for (t = all_threads; t != END_TSO_QUEUE; t = next) {
- next = t->link;
+ if (pid) { // parent
+
+ // just return the pid
+ rts_unlock(cap);
+ return pid;
+
+ } else { // child
+
+ // delete all threads
+ cap->run_queue_hd = END_TSO_QUEUE;
+ cap->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(cap,t);
+ }
+
+ // wipe the task list
+ ACQUIRE_LOCK(&sched_mutex);
+ for (task = all_tasks; task != NULL; task=task->all_link) {
+ if (task != cap->running_task) discardTask(task);
+ }
+ RELEASE_LOCK(&sched_mutex);
- // don't allow threads to catch the ThreadKilled exception
- deleteThreadImmediately(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);
+ cap->suspended_ccalling_tasks = NULL;
+
+#if defined(THREADED_RTS)
+ // wipe our spare workers list.
+ cap->spare_workers = NULL;
+ cap->returning_tasks_hd = NULL;
+ cap->returning_tasks_tl = NULL;
+#endif
+
+ cap = rts_evalStableIO(cap, entry, NULL); // run the action
+ rts_checkSchedStatus("forkProcess",cap);
+
+ rts_unlock(cap);
+ hs_exit(); // clean up and exit
+ stg_exit(EXIT_SUCCESS);
}
-
-# ifdef RTS_SUPPORTS_THREADS
- resetTaskManagerAfterFork(); // tell startTask() and friends that
- startingWorkerThread = rtsFalse; // we have no worker threads any more
- resetWorkerWakeupPipeAfterFork();
-# endif
-
- rc = rts_evalStableIO(entry, NULL); // run the action
- rts_checkSchedStatus("forkProcess",rc);
-
- rts_unlock();
-
- hs_exit(); // clean up and exit
- stg_exit(0);
- }
#else /* !FORKPROCESS_PRIMOP_SUPPORTED */
- barf("forkProcess#: primop not supported, sorry!\n");
- return -1;
+ barf("forkProcess#: primop not supported on this platform, sorry!\n");
+ return -1;
#endif
}
/* ---------------------------------------------------------------------------
- * deleteAllThreads(): kill all the live threads.
- *
- * This is used when we catch a user interrupt (^C), before performing
- * any necessary cleanups and running finalizers.
- *
- * Locks: sched_mutex held.
+ * Delete the threads on the run queue of the current capability.
* ------------------------------------------------------------------------- */
-void
-deleteAllThreads ( void )
+static void
+deleteRunQueue (Capability *cap)
{
- StgTSO* t, *next;
- IF_DEBUG(scheduler,sched_belch("deleting all threads"));
- for (t = all_threads; t != END_TSO_QUEUE; t = next) {
- next = t->global_link;
- deleteThread(t);
- }
-
- // 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(sleeping_queue == END_TSO_QUEUE);
+ StgTSO *t, *next;
+ for (t = cap->run_queue_hd; t != END_TSO_QUEUE; t = next) {
+ ASSERT(t->what_next != ThreadRelocated);
+ next = t->link;
+ deleteThread(cap, t);
+ }
}
/* startThread and insertThread are now in GranSim.c -- HWL */
+/* -----------------------------------------------------------------------------
+ Managing the suspended_ccalling_tasks list.
+ Locks required: sched_mutex
+ -------------------------------------------------------------------------- */
+
+STATIC_INLINE void
+suspendTask (Capability *cap, Task *task)
+{
+ ASSERT(task->next == NULL && task->prev == NULL);
+ task->next = cap->suspended_ccalling_tasks;
+ task->prev = NULL;
+ if (cap->suspended_ccalling_tasks) {
+ cap->suspended_ccalling_tasks->prev = task;
+ }
+ cap->suspended_ccalling_tasks = task;
+}
+
+STATIC_INLINE void
+recoverSuspendedTask (Capability *cap, Task *task)
+{
+ if (task->prev) {
+ task->prev->next = task->next;
+ } else {
+ ASSERT(cap->suspended_ccalling_tasks == task);
+ cap->suspended_ccalling_tasks = task->next;
+ }
+ if (task->next) {
+ task->next->prev = task->prev;
+ }
+ task->next = task->prev = NULL;
+}
+
/* ---------------------------------------------------------------------------
* Suspending & resuming Haskell threads.
*
* on return from the C function.
* ------------------------------------------------------------------------- */
-StgInt
-suspendThread( StgRegTable *reg,
- rtsBool concCall
-#if !defined(DEBUG)
- STG_UNUSED
-#endif
- )
+void *
+suspendThread (StgRegTable *reg)
{
- nat tok;
Capability *cap;
int saved_errno = errno;
+ StgTSO *tso;
+ Task *task;
- /* assume that *reg is a pointer to the StgRegTable part
- * of a Capability.
+ /* assume that *reg is a pointer to the StgRegTable part of a Capability.
*/
- cap = (Capability *)((void *)((unsigned char*)reg - sizeof(StgFunTable)));
+ cap = regTableToCapability(reg);
- ACQUIRE_LOCK(&sched_mutex);
+ task = cap->running_task;
+ tso = cap->r.rCurrentTSO;
IF_DEBUG(scheduler,
- sched_belch("thread %d did a _ccall_gc (is_concurrent: %d)", cap->r.rCurrentTSO->id,concCall));
+ sched_belch("thread %d did a safe foreign call", cap->r.rCurrentTSO->id));
// XXX this might not be necessary --SDM
- cap->r.rCurrentTSO->what_next = ThreadRunGHC;
+ tso->what_next = ThreadRunGHC;
- threadPaused(cap->r.rCurrentTSO);
- cap->r.rCurrentTSO->link = suspended_ccalling_threads;
- suspended_ccalling_threads = cap->r.rCurrentTSO;
+ threadPaused(cap,tso);
- if(cap->r.rCurrentTSO->blocked_exceptions == NULL) {
- cap->r.rCurrentTSO->why_blocked = BlockedOnCCall;
- cap->r.rCurrentTSO->blocked_exceptions = END_TSO_QUEUE;
+ if(tso->blocked_exceptions == NULL) {
+ tso->why_blocked = BlockedOnCCall;
+ tso->blocked_exceptions = END_TSO_QUEUE;
} else {
- cap->r.rCurrentTSO->why_blocked = BlockedOnCCall_NoUnblockExc;
+ tso->why_blocked = BlockedOnCCall_NoUnblockExc;
}
- /* Use the thread ID as the token; it should be unique */
- tok = cap->r.rCurrentTSO->id;
+ // Hand back capability
+ task->suspended_tso = tso;
- /* Hand back capability */
- releaseCapability(cap);
+ ACQUIRE_LOCK(&cap->lock);
+
+ suspendTask(cap,task);
+ cap->in_haskell = rtsFalse;
+ releaseCapability_(cap);
-#if defined(RTS_SUPPORTS_THREADS)
+ RELEASE_LOCK(&cap->lock);
+
+#if defined(THREADED_RTS)
/* Preparing to leave the RTS, so ensure there's a native thread/task
waiting to take over.
*/
- IF_DEBUG(scheduler, sched_belch("worker (token %d): leaving RTS", tok));
+ IF_DEBUG(scheduler, sched_belch("thread %d: leaving RTS", tso->id));
#endif
- /* Other threads _might_ be available for execution; signal this */
- THREAD_RUNNABLE();
- RELEASE_LOCK(&sched_mutex);
-
errno = saved_errno;
- return tok;
+ return task;
}
StgRegTable *
-resumeThread( StgInt tok,
- rtsBool concCall STG_UNUSED )
+resumeThread (void *task_)
{
- 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);
- waitForReturnCapability(&sched_mutex, &cap);
-
- IF_DEBUG(scheduler, sched_belch("worker (token %d): re-entering RTS", tok));
-#else
- grabCapability(&cap);
-#endif
-
- /* Remove the thread off of the suspended list */
- prev = &suspended_ccalling_threads;
- for (tso = suspended_ccalling_threads;
- tso != END_TSO_QUEUE;
- prev = &tso->link, tso = tso->link) {
- if (tso->id == (StgThreadID)tok) {
- *prev = tso->link;
- break;
+ StgTSO *tso;
+ Capability *cap;
+ int saved_errno = errno;
+ Task *task = task_;
+
+ cap = task->cap;
+ // Wait for permission to re-enter the RTS with the result.
+ waitForReturnCapability(&cap,task);
+ // we might be on a different capability now... but if so, our
+ // entry on the suspended_ccalling_tasks list will also have been
+ // migrated.
+
+ // Remove the thread from the suspended list
+ recoverSuspendedTask(cap,task);
+
+ tso = task->suspended_tso;
+ task->suspended_tso = NULL;
+ tso->link = END_TSO_QUEUE;
+ IF_DEBUG(scheduler, sched_belch("thread %d: re-entering RTS", tso->id));
+
+ if (tso->why_blocked == BlockedOnCCall) {
+ awakenBlockedQueue(cap,tso->blocked_exceptions);
+ tso->blocked_exceptions = NULL;
}
- }
- if (tso == END_TSO_QUEUE) {
- barf("resumeThread: thread not found");
- }
- tso->link = END_TSO_QUEUE;
-
- if(tso->why_blocked == BlockedOnCCall) {
- awakenBlockedQueueNoLock(tso->blocked_exceptions);
- tso->blocked_exceptions = NULL;
- }
-
- /* Reset blocking status */
- tso->why_blocked = NotBlocked;
+
+ /* Reset blocking status */
+ tso->why_blocked = NotBlocked;
+
+ cap->r.rCurrentTSO = tso;
+ cap->in_haskell = rtsTrue;
+ errno = saved_errno;
- cap->r.rCurrentTSO = tso;
- RELEASE_LOCK(&sched_mutex);
- errno = saved_errno;
- return &cap->r;
+ return &cap->r;
}
-
-/* ---------------------------------------------------------------------------
- * Static functions
- * ------------------------------------------------------------------------ */
-static void unblockThread(StgTSO *tso);
-
/* ---------------------------------------------------------------------------
* Comparing Thread ids.
*
createThread(nat size, StgInt pri)
#else
StgTSO *
-createThread(nat size)
+createThread(Capability *cap, nat size)
#endif
{
-
StgTSO *tso;
nat stack_size;
+ /* sched_mutex is *not* required */
+
/* First check whether we should create a thread at all */
-#if defined(PAR)
- /* check that no more than RtsFlags.ParFlags.maxThreads threads are created */
- if (advisory_thread_count >= RtsFlags.ParFlags.maxThreads) {
- threadsIgnored++;
- belch("{createThread}Daq ghuH: refusing to create another thread; no more than %d threads allowed (currently %d)",
- RtsFlags.ParFlags.maxThreads, advisory_thread_count);
- return END_TSO_QUEUE;
- }
- threadsCreated++;
+#if defined(PARALLEL_HASKELL)
+ /* check that no more than RtsFlags.ParFlags.maxThreads threads are created */
+ if (advisory_thread_count >= RtsFlags.ParFlags.maxThreads) {
+ threadsIgnored++;
+ debugBelch("{createThread}Daq ghuH: refusing to create another thread; no more than %d threads allowed (currently %d)\n",
+ RtsFlags.ParFlags.maxThreads, advisory_thread_count);
+ return END_TSO_QUEUE;
+ }
+ threadsCreated++;
#endif
#if defined(GRAN)
- ASSERT(!RtsFlags.GranFlags.Light || CurrentProc==0);
+ ASSERT(!RtsFlags.GranFlags.Light || CurrentProc==0);
#endif
- // ToDo: check whether size = stack_size - TSO_STRUCT_SIZEW
-
- /* catch ridiculously small stack sizes */
- if (size < MIN_STACK_WORDS + TSO_STRUCT_SIZEW) {
- size = MIN_STACK_WORDS + TSO_STRUCT_SIZEW;
- }
+ // ToDo: check whether size = stack_size - TSO_STRUCT_SIZEW
- stack_size = size - TSO_STRUCT_SIZEW;
+ /* catch ridiculously small stack sizes */
+ if (size < MIN_STACK_WORDS + TSO_STRUCT_SIZEW) {
+ size = MIN_STACK_WORDS + TSO_STRUCT_SIZEW;
+ }
- tso = (StgTSO *)allocate(size);
- TICK_ALLOC_TSO(stack_size, 0);
+ stack_size = size - TSO_STRUCT_SIZEW;
+
+ tso = (StgTSO *)allocateLocal(cap, size);
+ TICK_ALLOC_TSO(stack_size, 0);
- SET_HDR(tso, &stg_TSO_info, CCS_SYSTEM);
+ SET_HDR(tso, &stg_TSO_info, CCS_SYSTEM);
#if defined(GRAN)
- SET_GRAN_HDR(tso, ThisPE);
+ SET_GRAN_HDR(tso, ThisPE);
#endif
- // Always start with the compiled code evaluator
- tso->what_next = ThreadRunGHC;
-
- tso->id = next_thread_id++;
- tso->why_blocked = NotBlocked;
- tso->blocked_exceptions = NULL;
+ // Always start with the compiled code evaluator
+ tso->what_next = ThreadRunGHC;
- 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->why_blocked = NotBlocked;
+ tso->blocked_exceptions = NULL;
+
+ tso->saved_errno = 0;
+ tso->bound = NULL;
+
+ tso->stack_size = stack_size;
+ tso->max_stack_size = round_to_mblocks(RtsFlags.GcFlags.maxStkSize)
+ - TSO_STRUCT_SIZEW;
+ tso->sp = (P_)&(tso->stack) + stack_size;
+ tso->trec = NO_TREC;
+
#ifdef PROFILING
- tso->prof.CCCS = CCS_MAIN;
+ tso->prof.CCCS = CCS_MAIN;
#endif
-
+
/* put a stop frame on the stack */
- tso->sp -= sizeofW(StgStopFrame);
- SET_HDR((StgClosure*)tso->sp,(StgInfoTable *)&stg_stop_thread_info,CCS_SYSTEM);
- tso->link = END_TSO_QUEUE;
-
+ 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)
- /* uses more flexible routine in GranSim */
- insertThread(tso, CurrentProc);
+ /* uses more flexible routine in GranSim */
+ insertThread(tso, CurrentProc);
#else
- /* In a non-GranSim setup the pushing of a TSO onto the runq is separated
- * from its creation
- */
+ /* In a non-GranSim setup the pushing of a TSO onto the runq is separated
+ * from its creation
+ */
#endif
-
+
#if defined(GRAN)
- if (RtsFlags.GranFlags.GranSimStats.Full)
- DumpGranEvent(GR_START,tso);
-#elif defined(PAR)
- if (RtsFlags.ParFlags.ParStats.Full)
- DumpGranEvent(GR_STARTQ,tso);
- /* HACk to avoid SCHEDULE
- LastTSO = tso; */
+ if (RtsFlags.GranFlags.GranSimStats.Full)
+ DumpGranEvent(GR_START,tso);
+#elif defined(PARALLEL_HASKELL)
+ if (RtsFlags.ParFlags.ParStats.Full)
+ DumpGranEvent(GR_STARTQ,tso);
+ /* HACk to avoid SCHEDULE
+ LastTSO = tso; */
#endif
-
- /* Link the new thread on the global thread list.
- */
- tso->global_link = all_threads;
- all_threads = tso;
-
+
+ /* Link the new thread on the global thread list.
+ */
+ ACQUIRE_LOCK(&sched_mutex);
+ tso->id = next_thread_id++; // while we have the mutex
+ tso->global_link = all_threads;
+ all_threads = tso;
+ RELEASE_LOCK(&sched_mutex);
+
#if defined(DIST)
- tso->dist.priority = MandatoryPriority; //by default that is...
+ tso->dist.priority = MandatoryPriority; //by default that is...
#endif
-
+
#if defined(GRAN)
- tso->gran.pri = pri;
+ tso->gran.pri = pri;
# if defined(DEBUG)
- tso->gran.magic = TSO_MAGIC; // debugging only
+ tso->gran.magic = TSO_MAGIC; // debugging only
# endif
- tso->gran.sparkname = 0;
- tso->gran.startedat = CURRENT_TIME;
- tso->gran.exported = 0;
- tso->gran.basicblocks = 0;
- tso->gran.allocs = 0;
- tso->gran.exectime = 0;
- tso->gran.fetchtime = 0;
- tso->gran.fetchcount = 0;
- tso->gran.blocktime = 0;
- tso->gran.blockcount = 0;
- tso->gran.blockedat = 0;
- tso->gran.globalsparks = 0;
- tso->gran.localsparks = 0;
- if (RtsFlags.GranFlags.Light)
- tso->gran.clock = Now; /* local clock */
- else
- tso->gran.clock = 0;
-
- IF_DEBUG(gran,printTSO(tso));
-#elif defined(PAR)
+ tso->gran.sparkname = 0;
+ tso->gran.startedat = CURRENT_TIME;
+ tso->gran.exported = 0;
+ tso->gran.basicblocks = 0;
+ tso->gran.allocs = 0;
+ tso->gran.exectime = 0;
+ tso->gran.fetchtime = 0;
+ tso->gran.fetchcount = 0;
+ tso->gran.blocktime = 0;
+ tso->gran.blockcount = 0;
+ tso->gran.blockedat = 0;
+ tso->gran.globalsparks = 0;
+ tso->gran.localsparks = 0;
+ if (RtsFlags.GranFlags.Light)
+ tso->gran.clock = Now; /* local clock */
+ else
+ tso->gran.clock = 0;
+
+ IF_DEBUG(gran,printTSO(tso));
+#elif defined(PARALLEL_HASKELL)
# if defined(DEBUG)
- tso->par.magic = TSO_MAGIC; // debugging only
+ tso->par.magic = TSO_MAGIC; // debugging only
# endif
- tso->par.sparkname = 0;
- tso->par.startedat = CURRENT_TIME;
- tso->par.exported = 0;
- tso->par.basicblocks = 0;
- tso->par.allocs = 0;
- tso->par.exectime = 0;
- tso->par.fetchtime = 0;
- tso->par.fetchcount = 0;
- tso->par.blocktime = 0;
- tso->par.blockcount = 0;
- tso->par.blockedat = 0;
- tso->par.globalsparks = 0;
- tso->par.localsparks = 0;
+ tso->par.sparkname = 0;
+ tso->par.startedat = CURRENT_TIME;
+ tso->par.exported = 0;
+ tso->par.basicblocks = 0;
+ tso->par.allocs = 0;
+ tso->par.exectime = 0;
+ tso->par.fetchtime = 0;
+ tso->par.fetchcount = 0;
+ tso->par.blocktime = 0;
+ tso->par.blockcount = 0;
+ tso->par.blockedat = 0;
+ tso->par.globalsparks = 0;
+ tso->par.localsparks = 0;
#endif
-
+
#if defined(GRAN)
- globalGranStats.tot_threads_created++;
- globalGranStats.threads_created_on_PE[CurrentProc]++;
- globalGranStats.tot_sq_len += spark_queue_len(CurrentProc);
- globalGranStats.tot_sq_probes++;
-#elif defined(PAR)
- // collect parallel global statistics (currently done together with GC stats)
- if (RtsFlags.ParFlags.ParStats.Global &&
- RtsFlags.GcFlags.giveStats > NO_GC_STATS) {
- //fprintf(stderr, "Creating thread %d @ %11.2f\n", tso->id, usertime());
- globalParStats.tot_threads_created++;
- }
+ globalGranStats.tot_threads_created++;
+ globalGranStats.threads_created_on_PE[CurrentProc]++;
+ globalGranStats.tot_sq_len += spark_queue_len(CurrentProc);
+ globalGranStats.tot_sq_probes++;
+#elif defined(PARALLEL_HASKELL)
+ // collect parallel global statistics (currently done together with GC stats)
+ if (RtsFlags.ParFlags.ParStats.Global &&
+ RtsFlags.GcFlags.giveStats > NO_GC_STATS) {
+ //debugBelch("Creating thread %d @ %11.2f\n", tso->id, usertime());
+ globalParStats.tot_threads_created++;
+ }
#endif
-
+
#if defined(GRAN)
- IF_GRAN_DEBUG(pri,
- belch("==__ schedule: Created TSO %d (%p);",
- CurrentProc, tso, tso->id));
-#elif defined(PAR)
+ IF_GRAN_DEBUG(pri,
+ sched_belch("==__ schedule: Created TSO %d (%p);",
+ CurrentProc, tso, tso->id));
+#elif defined(PARALLEL_HASKELL)
IF_PAR_DEBUG(verbose,
- belch("==__ schedule: Created TSO %d (%p); %d threads active",
- tso->id, tso, advisory_thread_count));
+ sched_belch("==__ schedule: Created TSO %d (%p); %d threads active",
+ (long)tso->id, tso, advisory_thread_count));
#else
- IF_DEBUG(scheduler,sched_belch("created thread %ld, stack size = %lx words",
- tso->id, tso->stack_size));
+ IF_DEBUG(scheduler,sched_belch("created thread %ld, stack size = %lx words",
+ (long)tso->id, (long)tso->stack_size));
#endif
- return tso;
+ return tso;
}
#if defined(PAR)
all parallel thread creation calls should fall through the following routine.
*/
StgTSO *
-createSparkThread(rtsSpark spark)
+createThreadFromSpark(rtsSpark spark)
{ StgTSO *tso;
ASSERT(spark != (rtsSpark)NULL);
+// JB: TAKE CARE OF THIS COUNTER! BUGGY
if (advisory_thread_count >= RtsFlags.ParFlags.maxThreads)
{ threadsIgnored++;
barf("{createSparkThread}Daq ghuH: refusing to create another thread; no more than %d threads allowed (currently %d)",
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)
+#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,
- Capability *initialCapability
- );
-
-
/* ---------------------------------------------------------------------------
* scheduleThread()
*
- * scheduleThread puts a thread on the head of the runnable queue.
+ * scheduleThread puts a thread on the end of the runnable queue.
* This will usually be done immediately after a thread is created.
* The caller of scheduleThread must create the thread using e.g.
* createThread and push an appropriate closure
* on this thread's stack before the scheduler is invoked.
* ------------------------------------------------------------------------ */
-static void scheduleThread_ (StgTSO* tso);
-
void
-scheduleThread_(StgTSO *tso)
+scheduleThread(Capability *cap, StgTSO *tso)
{
- // Precondition: sched_mutex must be held.
- // 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);
- THREAD_RUNNABLE();
+ // The thread goes at the *end* of the run-queue, to avoid possible
+ // starvation of any threads already on the queue.
+ appendToRunQueue(cap,tso);
}
-void
-scheduleThread(StgTSO* tso)
+Capability *
+scheduleWaitThread (StgTSO* tso, /*[out]*/HaskellObj* ret, Capability *cap)
{
- ACQUIRE_LOCK(&sched_mutex);
- scheduleThread_(tso);
- RELEASE_LOCK(&sched_mutex);
-}
+ Task *task;
+
+ // We already created/initialised the Task
+ task = cap->running_task;
+
+ // This TSO is now a bound thread; make the Task and TSO
+ // point to each other.
+ tso->bound = task;
+
+ task->tso = tso;
+ task->ret = ret;
+ task->stat = NoStatus;
+
+ appendToRunQueue(cap,tso);
-#if defined(RTS_SUPPORTS_THREADS)
-static Condition bound_cond_cache;
-static int bound_cond_cache_full = 0;
+ IF_DEBUG(scheduler, sched_belch("new bound thread (%d)", tso->id));
+
+#if defined(GRAN)
+ /* GranSim specific init */
+ CurrentTSO = m->tso; // the TSO to run
+ procStatus[MainProc] = Busy; // status of main PE
+ CurrentProc = MainProc; // PE to run it on
#endif
+ cap = schedule(cap,task);
+
+ ASSERT(task->stat != NoStatus);
+ ASSERT_FULL_CAPABILITY_INVARIANTS(cap,task);
+
+ IF_DEBUG(scheduler, sched_belch("bound thread (%d) finished", task->tso->id));
+ return cap;
+}
+
+/* ----------------------------------------------------------------------------
+ * Starting Tasks
+ * ------------------------------------------------------------------------- */
-SchedulerStatus
-scheduleWaitThread(StgTSO* tso, /*[out]*/HaskellObj* ret,
- Capability *initialCapability)
+#if defined(THREADED_RTS)
+void
+workerStart(Task *task)
{
- // Precondition: sched_mutex must be held
- StgMainThread *m;
+ Capability *cap;
- 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;
+ // See startWorkerTask().
+ ACQUIRE_LOCK(&task->lock);
+ cap = task->cap;
+ RELEASE_LOCK(&task->lock);
-#if defined(RTS_SUPPORTS_THREADS)
- // 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
+ // set the thread-local pointer to the Task:
+ taskEnter(task);
- /* 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 THREAD_RUNNABLE() here, because the thread is
- // bound and only runnable by *this* OS thread, so waking up other
- // workers will just slow things down.
+ // schedule() runs without a lock.
+ cap = schedule(cap,task);
- return waitThread_(m, initialCapability);
+ // On exit from schedule(), we have a Capability.
+ releaseCapability(cap);
+ taskStop(task);
}
+#endif
/* ---------------------------------------------------------------------------
* initScheduler()
{
#if defined(GRAN)
nat i;
-
for (i=0; i<=MAX_PROC; i++) {
run_queue_hds[i] = END_TSO_QUEUE;
run_queue_tls[i] = END_TSO_QUEUE;
blocked_queue_hds[i] = END_TSO_QUEUE;
blocked_queue_tls[i] = END_TSO_QUEUE;
ccalling_threadss[i] = END_TSO_QUEUE;
+ blackhole_queue[i] = END_TSO_QUEUE;
sleeping_queue = END_TSO_QUEUE;
}
-#else
- run_queue_hd = END_TSO_QUEUE;
- run_queue_tl = END_TSO_QUEUE;
+#elif !defined(THREADED_RTS)
blocked_queue_hd = END_TSO_QUEUE;
blocked_queue_tl = END_TSO_QUEUE;
sleeping_queue = END_TSO_QUEUE;
-#endif
-
- suspended_ccalling_threads = END_TSO_QUEUE;
+#endif
- main_threads = NULL;
- all_threads = END_TSO_QUEUE;
+ blackhole_queue = END_TSO_QUEUE;
+ all_threads = END_TSO_QUEUE;
context_switch = 0;
interrupted = 0;
RtsFlags.ConcFlags.ctxtSwitchTicks =
RtsFlags.ConcFlags.ctxtSwitchTime / TICK_MILLISECS;
-#if defined(RTS_SUPPORTS_THREADS)
+#if defined(THREADED_RTS)
/* Initialise the mutex and condition variables used by
* the scheduler. */
initMutex(&sched_mutex);
- initMutex(&term_mutex);
#endif
ACQUIRE_LOCK(&sched_mutex);
* floating around (only SMP builds have more than one).
*/
initCapabilities();
-
-#if defined(RTS_SUPPORTS_THREADS)
- /* start our haskell execution tasks */
- startTaskManager(0,taskStart);
-#endif
-#if /* defined(SMP) ||*/ defined(PAR)
+ initTaskManager();
+
+#if defined(SMP) || defined(PARALLEL_HASKELL)
initSparkPools();
#endif
+#if defined(SMP)
+ /*
+ * Eagerly start one worker to run each Capability, except for
+ * Capability 0. The idea is that we're probably going to start a
+ * bound thread on Capability 0 pretty soon, so we don't want a
+ * worker task hogging it.
+ */
+ {
+ nat i;
+ Capability *cap;
+ for (i = 1; i < n_capabilities; i++) {
+ cap = &capabilities[i];
+ ACQUIRE_LOCK(&cap->lock);
+ startWorkerTask(cap, workerStart);
+ RELEASE_LOCK(&cap->lock);
+ }
+ }
+#endif
+
RELEASE_LOCK(&sched_mutex);
}
void
exitScheduler( void )
{
-#if defined(RTS_SUPPORTS_THREADS)
- stopTaskManager();
-#endif
- 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???
- ------------------------------------------------------------------------- */
-
-static
-SchedulerStatus
-waitThread_(StgMainThread* m, Capability *initialCapability)
-{
- SchedulerStatus stat;
-
- // Precondition: sched_mutex must be held.
- IF_DEBUG(scheduler, sched_belch("new main thread (%d)", m->tso->id));
+ interrupted = rtsTrue;
+ shutting_down_scheduler = rtsTrue;
-#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
- schedule(m,initialCapability);
-#else
- schedule(m,initialCapability);
- ASSERT(m->stat != NoStatus);
-#endif
-
- stat = m->stat;
+#if defined(THREADED_RTS)
+ {
+ Task *task;
+ nat i;
+
+ ACQUIRE_LOCK(&sched_mutex);
+ task = newBoundTask();
+ RELEASE_LOCK(&sched_mutex);
-#if defined(RTS_SUPPORTS_THREADS)
- // 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);
- }
+ for (i = 0; i < n_capabilities; i++) {
+ shutdownCapability(&capabilities[i], task);
+ }
+ boundTaskExiting(task);
+ stopTaskManager();
+ }
#endif
-
- IF_DEBUG(scheduler, sched_belch("main thread (%d) finished", m->tso->id));
- stgFree(m);
-
- // Postcondition: sched_mutex still held
- return stat;
}
/* ---------------------------------------------------------------------------
void
GetRoots( evac_fn evac )
{
-#if defined(GRAN)
- {
nat i;
+ Capability *cap;
+ Task *task;
+
+#if defined(GRAN)
for (i=0; i<=RtsFlags.GranFlags.proc; i++) {
- if ((run_queue_hds[i] != END_TSO_QUEUE) && ((run_queue_hds[i] != NULL)))
- evac((StgClosure **)&run_queue_hds[i]);
- if ((run_queue_tls[i] != END_TSO_QUEUE) && ((run_queue_tls[i] != NULL)))
- evac((StgClosure **)&run_queue_tls[i]);
-
- if ((blocked_queue_hds[i] != END_TSO_QUEUE) && ((blocked_queue_hds[i] != NULL)))
- evac((StgClosure **)&blocked_queue_hds[i]);
- if ((blocked_queue_tls[i] != END_TSO_QUEUE) && ((blocked_queue_tls[i] != NULL)))
- evac((StgClosure **)&blocked_queue_tls[i]);
- if ((ccalling_threadss[i] != END_TSO_QUEUE) && ((ccalling_threadss[i] != NULL)))
- evac((StgClosure **)&ccalling_threads[i]);
+ if ((run_queue_hds[i] != END_TSO_QUEUE) && ((run_queue_hds[i] != NULL)))
+ evac((StgClosure **)&run_queue_hds[i]);
+ if ((run_queue_tls[i] != END_TSO_QUEUE) && ((run_queue_tls[i] != NULL)))
+ evac((StgClosure **)&run_queue_tls[i]);
+
+ if ((blocked_queue_hds[i] != END_TSO_QUEUE) && ((blocked_queue_hds[i] != NULL)))
+ evac((StgClosure **)&blocked_queue_hds[i]);
+ if ((blocked_queue_tls[i] != END_TSO_QUEUE) && ((blocked_queue_tls[i] != NULL)))
+ evac((StgClosure **)&blocked_queue_tls[i]);
+ if ((ccalling_threadss[i] != END_TSO_QUEUE) && ((ccalling_threadss[i] != NULL)))
+ evac((StgClosure **)&ccalling_threads[i]);
}
- }
- markEventQueue();
+ markEventQueue();
#else /* !GRAN */
- if (run_queue_hd != END_TSO_QUEUE) {
- ASSERT(run_queue_tl != END_TSO_QUEUE);
- evac((StgClosure **)&run_queue_hd);
- evac((StgClosure **)&run_queue_tl);
- }
-
- if (blocked_queue_hd != END_TSO_QUEUE) {
- ASSERT(blocked_queue_tl != END_TSO_QUEUE);
- evac((StgClosure **)&blocked_queue_hd);
- evac((StgClosure **)&blocked_queue_tl);
- }
-
- if (sleeping_queue != END_TSO_QUEUE) {
- evac((StgClosure **)&sleeping_queue);
- }
+
+ for (i = 0; i < n_capabilities; i++) {
+ cap = &capabilities[i];
+ evac((StgClosure **)&cap->run_queue_hd);
+ evac((StgClosure **)&cap->run_queue_tl);
+
+ for (task = cap->suspended_ccalling_tasks; task != NULL;
+ task=task->next) {
+ evac((StgClosure **)&task->suspended_tso);
+ }
+ }
+
+#if !defined(THREADED_RTS)
+ evac((StgClosure **)&blocked_queue_hd);
+ evac((StgClosure **)&blocked_queue_tl);
+ evac((StgClosure **)&sleeping_queue);
#endif
+#endif
- if (suspended_ccalling_threads != END_TSO_QUEUE) {
- evac((StgClosure **)&suspended_ccalling_threads);
- }
+ evac((StgClosure **)&blackhole_queue);
-#if defined(PAR) || defined(GRAN)
- markSparkQueue(evac);
+#if defined(SMP) || defined(PARALLEL_HASKELL) || defined(GRAN)
+ markSparkQueue(evac);
#endif
-
+
#if defined(RTS_USER_SIGNALS)
- // mark the signal handlers (signals should be already blocked)
- markSignalHandlers(evac);
+ // mark the signal handlers (signals should be already blocked)
+ markSignalHandlers(evac);
#endif
}
void
performGC(void)
{
- /* Obligated to hold this lock upon entry */
- ACQUIRE_LOCK(&sched_mutex);
- GarbageCollect(GetRoots,rtsFalse);
- RELEASE_LOCK(&sched_mutex);
+#ifdef THREADED_RTS
+ // ToDo: we have to grab all the capabilities here.
+ errorBelch("performGC not supported in threaded RTS (yet)");
+ stg_exit(EXIT_FAILURE);
+#endif
+ /* Obligated to hold this lock upon entry */
+ GarbageCollect(GetRoots,rtsFalse);
}
void
performMajorGC(void)
{
- ACQUIRE_LOCK(&sched_mutex);
- GarbageCollect(GetRoots,rtsTrue);
- RELEASE_LOCK(&sched_mutex);
+#ifdef THREADED_RTS
+ errorBelch("performMayjorGC not supported in threaded RTS (yet)");
+ stg_exit(EXIT_FAILURE);
+#endif
+ GarbageCollect(GetRoots,rtsTrue);
}
static void
void
performGCWithRoots(void (*get_roots)(evac_fn))
{
- ACQUIRE_LOCK(&sched_mutex);
- extra_roots = get_roots;
- GarbageCollect(AllRoots,rtsFalse);
- RELEASE_LOCK(&sched_mutex);
+#ifdef THREADED_RTS
+ errorBelch("performGCWithRoots not supported in threaded RTS (yet)");
+ stg_exit(EXIT_FAILURE);
+#endif
+ extra_roots = get_roots;
+ GarbageCollect(AllRoots,rtsFalse);
}
/* -----------------------------------------------------------------------------
-------------------------------------------------------------------------- */
static StgTSO *
-threadStackOverflow(StgTSO *tso)
+threadStackOverflow(Capability *cap, 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)));
/* Send this thread the StackOverflow exception */
- raiseAsync(tso, (StgClosure *)stackOverflow_closure);
+ raiseAsync(cap, tso, (StgClosure *)stackOverflow_closure);
return tso;
}
* Finally round up so the TSO ends up as a whole number of blocks.
*/
new_stack_size = stg_min(tso->stack_size * 2, tso->max_stack_size);
- new_tso_size = (nat)BLOCK_ROUND_UP(new_stack_size * sizeof(W_) +
+ new_tso_size = (lnat)BLOCK_ROUND_UP(new_stack_size * sizeof(W_) +
TSO_STRUCT_SIZE)/sizeof(W_);
new_tso_size = round_to_mblocks(new_tso_size); /* Be MBLOCK-friendly */
new_stack_size = new_tso_size - TSO_STRUCT_SIZEW;
- IF_DEBUG(scheduler, fprintf(stderr,"== sched: increasing stack size from %d words to %d.\n", tso->stack_size, new_stack_size));
+ IF_DEBUG(scheduler, sched_belch("increasing stack size from %ld words to %d.\n", (long)tso->stack_size, new_stack_size));
dest = (StgTSO *)allocate(new_tso_size);
TICK_ALLOC_TSO(new_stack_size,0);
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,
unblockCount ( StgBlockingQueueElement *bqe, StgClosure *node )
{
}
-#elif defined(PAR)
+#elif defined(PARALLEL_HASKELL)
STATIC_INLINE void
unblockCount ( StgBlockingQueueElement *bqe, StgClosure *node )
{
DumpRawGranEvent(CURRENT_PROC, CURRENT_PROC,
GR_RESUMEQ, ((StgTSO *)bqe), ((StgTSO *)bqe)->block_info.closure,
0, 0 /* spark_queue_len(ADVISORY_POOL) */);
- if (EMPTY_RUN_QUEUE())
+ if (emptyRunQueue())
emitSchedule = rtsTrue;
switch (get_itbl(node)->type) {
break;
#endif
default:
- barf("{unblockOneLocked}Daq Qagh: unexpected closure in blocking queue");
+ barf("{unblockOne}Daq Qagh: unexpected closure in blocking queue");
}
}
}
#endif
#if defined(GRAN)
-static StgBlockingQueueElement *
-unblockOneLocked(StgBlockingQueueElement *bqe, StgClosure *node)
+StgBlockingQueueElement *
+unblockOne(StgBlockingQueueElement *bqe, StgClosure *node)
{
StgTSO *tso;
PEs node_loc, tso_loc;
}
/* the thread-queue-overhead is accounted for in either Resume or UnblockThread */
IF_GRAN_DEBUG(bq,
- fprintf(stderr," %s TSO %d (%p) [PE %d] (block_info.closure=%p) (next=%p) ,",
+ debugBelch(" %s TSO %d (%p) [PE %d] (block_info.closure=%p) (next=%p) ,",
(node_loc==tso_loc ? "Local" : "Global"),
tso->id, tso, CurrentProc, tso->block_info.closure, tso->link));
tso->block_info.closure = NULL;
- IF_DEBUG(scheduler,belch("-- Waking up thread %ld (%p)",
+ IF_DEBUG(scheduler,debugBelch("-- Waking up thread %ld (%p)\n",
tso->id, tso));
}
-#elif defined(PAR)
-static StgBlockingQueueElement *
-unblockOneLocked(StgBlockingQueueElement *bqe, StgClosure *node)
+#elif defined(PARALLEL_HASKELL)
+StgBlockingQueueElement *
+unblockOne(StgBlockingQueueElement *bqe, StgClosure *node)
{
StgBlockingQueueElement *next;
ASSERT(((StgTSO *)bqe)->why_blocked != NotBlocked);
/* if it's a TSO just push it onto the run_queue */
next = bqe->link;
- // ((StgTSO *)bqe)->link = END_TSO_QUEUE; // debugging?
+ ((StgTSO *)bqe)->link = END_TSO_QUEUE; // debugging?
APPEND_TO_RUN_QUEUE((StgTSO *)bqe);
- THREAD_RUNNABLE();
+ threadRunnable();
unblockCount(bqe, node);
/* reset blocking status after dumping event */
((StgTSO *)bqe)->why_blocked = NotBlocked;
break;
default:
- barf("{unblockOneLocked}Daq Qagh: Unexpected IP (%#lx; %s) in blocking queue at %#lx\n",
+ barf("{unblockOne}Daq Qagh: Unexpected IP (%#lx; %s) in blocking queue at %#lx\n",
get_itbl((StgClosure *)bqe), info_type((StgClosure *)bqe),
(StgClosure *)bqe);
# endif
}
- IF_PAR_DEBUG(bq, fprintf(stderr, ", %p (%s)", bqe, info_type((StgClosure*)bqe)));
+ IF_PAR_DEBUG(bq, debugBelch(", %p (%s)\n", bqe, info_type((StgClosure*)bqe)));
return next;
}
+#endif
-#else /* !GRAN && !PAR */
-static StgTSO *
-unblockOneLocked(StgTSO *tso)
+StgTSO *
+unblockOne(Capability *cap, StgTSO *tso)
{
StgTSO *next;
ASSERT(tso->why_blocked != NotBlocked);
tso->why_blocked = NotBlocked;
next = tso->link;
- APPEND_TO_RUN_QUEUE(tso);
- THREAD_RUNNABLE();
- IF_DEBUG(scheduler,sched_belch("waking up thread %ld", tso->id));
+ tso->link = END_TSO_QUEUE;
+
+ // We might have just migrated this TSO to our Capability:
+ if (tso->bound) {
+ tso->bound->cap = cap;
+ }
+
+ appendToRunQueue(cap,tso);
+
+ // we're holding a newly woken thread, make sure we context switch
+ // quickly so we can migrate it if necessary.
+ context_switch = 1;
+ IF_DEBUG(scheduler,sched_belch("waking up thread %ld", (long)tso->id));
return next;
}
-#endif
-#if defined(GRAN) || defined(PAR)
-INLINE_ME StgBlockingQueueElement *
-unblockOne(StgBlockingQueueElement *bqe, StgClosure *node)
-{
- ACQUIRE_LOCK(&sched_mutex);
- bqe = unblockOneLocked(bqe, node);
- RELEASE_LOCK(&sched_mutex);
- return bqe;
-}
-#else
-INLINE_ME StgTSO *
-unblockOne(StgTSO *tso)
-{
- ACQUIRE_LOCK(&sched_mutex);
- tso = unblockOneLocked(tso);
- RELEASE_LOCK(&sched_mutex);
- return tso;
-}
-#endif
#if defined(GRAN)
void
nat len = 0;
IF_GRAN_DEBUG(bq,
- belch("##-_ AwBQ for node %p on PE %d @ %ld by TSO %d (%p): ", \
+ debugBelch("##-_ AwBQ for node %p on PE %d @ %ld by TSO %d (%p): \n", \
node, CurrentProc, CurrentTime[CurrentProc],
CurrentTSO->id, CurrentTSO));
*/
if (CurrentProc!=node_loc) {
IF_GRAN_DEBUG(bq,
- belch("## node %p is on PE %d but CurrentProc is %d (TSO %d); assuming fake fetch and adjusting bitmask (old: %#x)",
+ debugBelch("## node %p is on PE %d but CurrentProc is %d (TSO %d); assuming fake fetch and adjusting bitmask (old: %#x)\n",
node, node_loc, CurrentProc, CurrentTSO->id,
// CurrentTSO, where_is(CurrentTSO),
node->header.gran.procs));
node->header.gran.procs = (node->header.gran.procs) | PE_NUMBER(CurrentProc);
IF_GRAN_DEBUG(bq,
- belch("## new bitmask of node %p is %#x",
+ debugBelch("## new bitmask of node %p is %#x\n",
node, node->header.gran.procs));
if (RtsFlags.GranFlags.GranSimStats.Global) {
globalGranStats.tot_fake_fetches++;
//tso = (StgTSO *)bqe; // wastes an assignment to get the type right
//tso_loc = where_is(tso);
len++;
- bqe = unblockOneLocked(bqe, node);
+ bqe = unblockOne(bqe, node);
}
/* if this is the BQ of an RBH, we have to put back the info ripped out of
((StgRBH *)node)->mut_link = (StgMutClosure *)((StgRBHSave *)bqe)->payload[1];
IF_GRAN_DEBUG(bq,
- belch("## Filled in RBH_Save for %p (%s) at end of AwBQ",
+ debugBelch("## Filled in RBH_Save for %p (%s) at end of AwBQ\n",
node, info_type(node)));
}
globalGranStats.tot_awbq++; // total no. of bqs awakened
}
IF_GRAN_DEBUG(bq,
- fprintf(stderr,"## BQ Stats of %p: [%d entries] %s\n",
+ debugBelch("## BQ Stats of %p: [%d entries] %s\n",
node, len, (bqe!=END_BQ_QUEUE) ? "RBH" : ""));
}
-#elif defined(PAR)
+#elif defined(PARALLEL_HASKELL)
void
awakenBlockedQueue(StgBlockingQueueElement *q, StgClosure *node)
{
StgBlockingQueueElement *bqe;
- ACQUIRE_LOCK(&sched_mutex);
-
IF_PAR_DEBUG(verbose,
- belch("##-_ AwBQ for node %p on [%x]: ",
+ debugBelch("##-_ AwBQ for node %p on [%x]: \n",
node, mytid));
#ifdef DIST
//RFP
if(get_itbl(q)->type == CONSTR || q==END_BQ_QUEUE) {
- IF_PAR_DEBUG(verbose, belch("## ... nothing to unblock so lets just return. RFP (BUG?)"));
+ IF_PAR_DEBUG(verbose, debugBelch("## ... nothing to unblock so lets just return. RFP (BUG?)\n"));
return;
}
#endif
bqe = q;
while (get_itbl(bqe)->type==TSO ||
get_itbl(bqe)->type==BLOCKED_FETCH) {
- bqe = unblockOneLocked(bqe, node);
+ bqe = unblockOne(bqe, node);
}
- RELEASE_LOCK(&sched_mutex);
}
-#else /* !GRAN && !PAR */
-
-void
-awakenBlockedQueueNoLock(StgTSO *tso)
-{
- while (tso != END_TSO_QUEUE) {
- tso = unblockOneLocked(tso);
- }
-}
+#else /* !GRAN && !PARALLEL_HASKELL */
void
-awakenBlockedQueue(StgTSO *tso)
+awakenBlockedQueue(Capability *cap, StgTSO *tso)
{
- ACQUIRE_LOCK(&sched_mutex);
- while (tso != END_TSO_QUEUE) {
- tso = unblockOneLocked(tso);
- }
- RELEASE_LOCK(&sched_mutex);
+ if (tso == NULL) return; // hack; see bug #1235728, and comments in
+ // Exception.cmm
+ while (tso != END_TSO_QUEUE) {
+ tso = unblockOne(cap,tso);
+ }
}
#endif
{
interrupted = 1;
context_switch = 1;
-#ifdef RTS_SUPPORTS_THREADS
- wakeBlockedWorkerThread();
+#if defined(THREADED_RTS)
+ prodAllCapabilities();
#endif
}
This has nothing to do with the UnblockThread event in GranSim. -- HWL
-------------------------------------------------------------------------- */
-#if defined(GRAN) || defined(PAR)
+#if defined(GRAN) || defined(PARALLEL_HASKELL)
/*
NB: only the type of the blocking queue is different in GranSim and GUM
the operations on the queue-elements are the same
*/
static void
-unblockThread(StgTSO *tso)
+unblockThread(Capability *cap, StgTSO *tso)
{
StgBlockingQueueElement *t, **last;
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_TARGET_OS)
+#if defined(mingw32_HOST_OS)
case BlockedOnDoProc:
#endif
{
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;
}
}
tso->link = END_TSO_QUEUE;
tso->why_blocked = NotBlocked;
tso->block_info.closure = NULL;
- PUSH_ON_RUN_QUEUE(tso);
+ pushOnRunQueue(cap,tso);
}
#else
static void
-unblockThread(StgTSO *tso)
+unblockThread(Capability *cap, StgTSO *tso)
{
StgTSO *t, **last;
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;
barf("unblockThread (Exception): TSO not found");
}
+#if !defined(THREADED_RTS)
case BlockedOnRead:
case BlockedOnWrite:
-#if defined(mingw32_TARGET_OS)
+#if defined(mingw32_HOST_OS)
case BlockedOnDoProc:
#endif
{
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;
}
}
}
barf("unblockThread (delay): TSO not found");
}
+#endif
default:
barf("unblockThread");
tso->link = END_TSO_QUEUE;
tso->why_blocked = NotBlocked;
tso->block_info.closure = NULL;
- APPEND_TO_RUN_QUEUE(tso);
+ appendToRunQueue(cap,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 (Capability *cap)
+{
+ StgTSO **prev, *t;
+ rtsBool any_woke_up = rtsFalse;
+ StgHalfWord type;
+
+ // blackhole_queue is global:
+ ASSERT_LOCK_HELD(&sched_mutex);
+
+ IF_DEBUG(scheduler, sched_belch("checking threads blocked on black holes"));
+
+ // ASSUMES: sched_mutex
+ prev = &blackhole_queue;
+ t = blackhole_queue;
+ while (t != END_TSO_QUEUE) {
+ ASSERT(t->why_blocked == BlockedOnBlackHole);
+ type = get_itbl(t->block_info.closure)->type;
+ if (type != BLACKHOLE && type != CAF_BLACKHOLE) {
+ IF_DEBUG(sanity,checkTSO(t));
+ t = unblockOne(cap, t);
+ // urk, the threads migrate to the current capability
+ // here, but we'd like to keep them on the original one.
+ *prev = t;
+ any_woke_up = rtsTrue;
+ } else {
+ prev = &t->link;
+ t = t->link;
+ }
+ }
+
+ return any_woke_up;
+}
+
+/* -----------------------------------------------------------------------------
* raiseAsync()
*
* The following function implements the magic for raising an
* CATCH_FRAME on the stack. In either case, we strip the entire
* stack and replace the thread with a zombie.
*
- * Locks: sched_mutex held upon entry nor exit.
+ * ToDo: in SMP mode, this function is only safe if either (a) we hold
+ * all the Capabilities (eg. in GC), or (b) we own the Capability that
+ * the TSO is currently blocked on or on the run queue of.
*
* -------------------------------------------------------------------------- */
-void
-deleteThread(StgTSO *tso)
+void
+raiseAsync(Capability *cap, StgTSO *tso, StgClosure *exception)
{
- raiseAsync(tso,NULL);
-}
-
-#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;
+ raiseAsync_(cap, tso, exception, rtsFalse, NULL);
}
-#endif
void
-raiseAsyncWithLock(StgTSO *tso, StgClosure *exception)
+suspendComputation(Capability *cap, StgTSO *tso, StgPtr stop_here)
{
- /* When raising async exs from contexts where sched_mutex isn't held;
- use raiseAsyncWithLock(). */
- ACQUIRE_LOCK(&sched_mutex);
- raiseAsync(tso,exception);
- RELEASE_LOCK(&sched_mutex);
+ raiseAsync_(cap, tso, NULL, rtsFalse, stop_here);
}
-void
-raiseAsync(StgTSO *tso, StgClosure *exception)
+static void
+raiseAsync_(Capability *cap, StgTSO *tso, StgClosure *exception,
+ rtsBool stop_at_atomically, StgPtr stop_here)
{
StgRetInfoTable *info;
- StgPtr sp;
+ StgPtr sp, frame;
+ nat i;
// Thread already dead?
- if (tso->what_next == ThreadComplete || tso->what_next == ThreadKilled) {
- return;
- }
-
- IF_DEBUG(scheduler,
- sched_belch("raising exception in thread %ld.", tso->id));
-
- // Remove it from any blocking queues
- unblockThread(tso);
-
- sp = tso->sp;
-
- // The stack freezing code assumes there's a closure pointer on
- // the top of the stack, so we have to arrange that this is the case...
- //
- if (sp[0] == (W_)&stg_enter_info) {
- sp++;
- } else {
- sp--;
- sp[0] = (W_)&stg_dummy_ret_closure;
- }
-
- while (1) {
- nat i;
-
- // 1. Let the top of the stack be the "current closure"
- //
- // 2. Walk up the stack until we find either an UPDATE_FRAME or a
- // CATCH_FRAME.
- //
- // 3. If it's an UPDATE_FRAME, then make an AP_STACK containing the
- // current closure applied to the chunk of stack up to (but not
- // including) the update frame. This closure becomes the "current
- // closure". Go back to step 2.
- //
- // 4. If it's a CATCH_FRAME, then leave the exception handler on
- // top of the stack applied to the exception.
- //
- // 5. If it's a STOP_FRAME, then kill the thread.
-
- StgPtr frame;
-
- frame = sp + 1;
- info = get_ret_itbl((StgClosure *)frame);
-
- while (info->i.type != UPDATE_FRAME
- && (info->i.type != CATCH_FRAME || exception == NULL)
- && info->i.type != STOP_FRAME) {
- frame += stack_frame_sizeW((StgClosure *)frame);
- info = get_ret_itbl((StgClosure *)frame);
- }
-
- switch (info->i.type) {
-
- case CATCH_FRAME:
- // If we find a CATCH_FRAME, and we've got an exception to raise,
- // then build the THUNK raise(exception), and leave it on
- // top of the CATCH_FRAME ready to enter.
- //
- {
-#ifdef PROFILING
- StgCatchFrame *cf = (StgCatchFrame *)frame;
-#endif
- StgClosure *raise;
-
- // we've got an exception to raise, so let's pass it to the
- // handler in this frame.
- //
- raise = (StgClosure *)allocate(sizeofW(StgClosure)+1);
- TICK_ALLOC_SE_THK(1,0);
- SET_HDR(raise,&stg_raise_info,cf->header.prof.ccs);
- raise->payload[0] = exception;
-
- // throw away the stack from Sp up to the CATCH_FRAME.
- //
- sp = frame - 1;
-
- /* Ensure that async excpetions are blocked now, so we don't get
- * a surprise exception before we get around to executing the
- * handler.
- */
- if (tso->blocked_exceptions == NULL) {
- tso->blocked_exceptions = END_TSO_QUEUE;
- }
-
- /* Put the newly-built THUNK on top of the stack, ready to execute
- * when the thread restarts.
- */
- sp[0] = (W_)raise;
- sp[-1] = (W_)&stg_enter_info;
- tso->sp = sp-1;
- tso->what_next = ThreadRunGHC;
- IF_DEBUG(sanity, checkTSO(tso));
- return;
- }
-
+ if (tso->what_next == ThreadComplete || tso->what_next == ThreadKilled) {
+ return;
+ }
+
+ IF_DEBUG(scheduler,
+ sched_belch("raising exception in thread %ld.", (long)tso->id));
+
+ // Remove it from any blocking queues
+ unblockThread(cap,tso);
+
+ sp = tso->sp;
+
+ // The stack freezing code assumes there's a closure pointer on
+ // the top of the stack, so we have to arrange that this is the case...
+ //
+ if (sp[0] == (W_)&stg_enter_info) {
+ sp++;
+ } else {
+ sp--;
+ sp[0] = (W_)&stg_dummy_ret_closure;
+ }
+
+ frame = sp + 1;
+ while (stop_here == NULL || frame < stop_here) {
+
+ // 1. Let the top of the stack be the "current closure"
+ //
+ // 2. Walk up the stack until we find either an UPDATE_FRAME or a
+ // CATCH_FRAME.
+ //
+ // 3. If it's an UPDATE_FRAME, then make an AP_STACK containing the
+ // current closure applied to the chunk of stack up to (but not
+ // including) the update frame. This closure becomes the "current
+ // closure". Go back to step 2.
+ //
+ // 4. If it's a CATCH_FRAME, then leave the exception handler on
+ // top of the stack applied to the exception.
+ //
+ // 5. If it's a STOP_FRAME, then kill the thread.
+ //
+ // NB: if we pass an ATOMICALLY_FRAME then abort the associated
+ // transaction
+
+ info = get_ret_itbl((StgClosure *)frame);
+
+ switch (info->i.type) {
+
case UPDATE_FRAME:
{
StgAP_STACK * ap;
// fun field.
//
words = frame - sp - 1;
- ap = (StgAP_STACK *)allocate(PAP_sizeW(words));
+ ap = (StgAP_STACK *)allocateLocal(cap,AP_STACK_sizeW(words));
ap->size = words;
ap->fun = (StgClosure *)sp[0];
TICK_ALLOC_UP_THK(words+1,0);
IF_DEBUG(scheduler,
- fprintf(stderr, "sched: Updating ");
+ debugBelch("sched: Updating ");
printPtr((P_)((StgUpdateFrame *)frame)->updatee);
- fprintf(stderr, " with ");
+ debugBelch(" with ");
printObj((StgClosure *)ap);
);
- // Replace the updatee with an indirection - happily
- // this will also wake up any threads currently
- // waiting on the result.
+ // Replace the updatee with an indirection
//
// Warning: if we're in a loop, more than one update frame on
// the stack may point to the same object. Be careful not to
//
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
- break;
+ frame = sp + 1;
+ continue; //no need to bump frame
}
-
+
case STOP_FRAME:
// We've stripped the entire stack, the thread is now dead.
- sp += sizeofW(StgStopFrame);
tso->what_next = ThreadKilled;
- tso->sp = sp;
+ tso->sp = frame + sizeofW(StgStopFrame);
+ return;
+
+ case CATCH_FRAME:
+ // If we find a CATCH_FRAME, and we've got an exception to raise,
+ // then build the THUNK raise(exception), and leave it on
+ // top of the CATCH_FRAME ready to enter.
+ //
+ {
+#ifdef PROFILING
+ StgCatchFrame *cf = (StgCatchFrame *)frame;
+#endif
+ StgThunk *raise;
+
+ if (exception == NULL) break;
+
+ // we've got an exception to raise, so let's pass it to the
+ // handler in this frame.
+ //
+ raise = (StgThunk *)allocateLocal(cap,sizeofW(StgThunk)+MIN_UPD_SIZE);
+ TICK_ALLOC_SE_THK(1,0);
+ SET_HDR(raise,&stg_raise_info,cf->header.prof.ccs);
+ raise->payload[0] = exception;
+
+ // throw away the stack from Sp up to the CATCH_FRAME.
+ //
+ sp = frame - 1;
+
+ /* Ensure that async excpetions are blocked now, so we don't get
+ * a surprise exception before we get around to executing the
+ * handler.
+ */
+ if (tso->blocked_exceptions == NULL) {
+ tso->blocked_exceptions = END_TSO_QUEUE;
+ }
+
+ /* Put the newly-built THUNK on top of the stack, ready to execute
+ * when the thread restarts.
+ */
+ sp[0] = (W_)raise;
+ sp[-1] = (W_)&stg_enter_info;
+ tso->sp = sp-1;
+ tso->what_next = ThreadRunGHC;
+ IF_DEBUG(sanity, checkTSO(tso));
return;
+ }
+
+ case ATOMICALLY_FRAME:
+ if (stop_at_atomically) {
+ ASSERT(stmGetEnclosingTRec(tso->trec) == NO_TREC);
+ stmCondemnTransaction(cap, tso -> trec);
+#ifdef REG_R1
+ tso->sp = frame;
+#else
+ // R1 is not a register: the return convention for IO in
+ // this case puts the return value on the stack, so we
+ // need to set up the stack to return to the atomically
+ // frame properly...
+ tso->sp = frame - 2;
+ tso->sp[1] = (StgWord) &stg_NO_FINALIZER_closure; // why not?
+ tso->sp[0] = (StgWord) &stg_ut_1_0_unreg_info;
+#endif
+ tso->what_next = ThreadRunGHC;
+ return;
+ }
+ // Not stop_at_atomically... fall through and abort the
+ // transaction.
+
+ case CATCH_RETRY_FRAME:
+ // IF we find an ATOMICALLY_FRAME then we abort the
+ // current transaction and propagate the exception. In
+ // this case (unlike ordinary exceptions) we do not care
+ // whether the transaction is valid or not because its
+ // possible validity cannot have caused the exception
+ // and will not be visible after the abort.
+ IF_DEBUG(stm,
+ debugBelch("Found atomically block delivering async exception\n"));
+ StgTRecHeader *trec = tso -> trec;
+ StgTRecHeader *outer = stmGetEnclosingTRec(trec);
+ stmAbortTransaction(cap, trec);
+ tso -> trec = outer;
+ break;
default:
- barf("raiseAsync");
+ break;
}
+
+ // move on to the next stack frame
+ frame += stack_frame_sizeW((StgClosure *)frame);
}
- barf("raiseAsync");
+
+ // if we got here, then we stopped at stop_here
+ ASSERT(stop_here != NULL);
}
/* -----------------------------------------------------------------------------
- resurrectThreads is called after garbage collection on the list of
- threads found to be garbage. Each of these threads will be woken
- up and sent a signal: BlockedOnDeadMVar if the thread was blocked
- on an MVar, or NonTermination if the thread was blocked on a Black
- Hole.
+ Deleting threads
- Locks: sched_mutex isn't held upon entry nor exit.
+ This is used for interruption (^C) and forking, and corresponds to
+ raising an exception but without letting the thread catch the
+ exception.
-------------------------------------------------------------------------- */
-void
-resurrectThreads( StgTSO *threads )
+static void
+deleteThread (Capability *cap, StgTSO *tso)
{
- StgTSO *tso, *next;
+ if (tso->why_blocked != BlockedOnCCall &&
+ tso->why_blocked != BlockedOnCCall_NoUnblockExc) {
+ raiseAsync(cap,tso,NULL);
+ }
+}
- for (tso = threads; tso != END_TSO_QUEUE; tso = next) {
- next = tso->global_link;
- tso->global_link = all_threads;
- all_threads = tso;
- IF_DEBUG(scheduler, sched_belch("resurrecting thread %d", tso->id));
+#ifdef FORKPROCESS_PRIMOP_SUPPORTED
+static void
+deleteThreadImmediately(Capability *cap, StgTSO *tso)
+{ // for forkProcess only:
+ // delete thread without giving it a chance to catch the KillThread exception
- switch (tso->why_blocked) {
- case BlockedOnMVar:
- case BlockedOnException:
- /* Called by GC - sched_mutex lock is currently held. */
- raiseAsync(tso,(StgClosure *)BlockedOnDeadMVar_closure);
- break;
- case BlockedOnBlackHole:
- raiseAsync(tso,(StgClosure *)NonTermination_closure);
- break;
- case NotBlocked:
- /* This might happen if the thread was blocked on a black hole
- * belonging to a thread that we've just woken up (raiseAsync
- * can wake up threads, remember...).
- */
- continue;
- default:
- barf("resurrectThreads: thread blocked in a strange way");
- }
+ if (tso->what_next == ThreadComplete || tso->what_next == ThreadKilled) {
+ return;
+ }
+
+ if (tso->why_blocked != BlockedOnCCall &&
+ tso->why_blocked != BlockedOnCCall_NoUnblockExc) {
+ unblockThread(cap,tso);
}
+
+ tso->what_next = ThreadKilled;
}
+#endif
/* -----------------------------------------------------------------------------
- * Blackhole detection: if we reach a deadlock, test whether any
- * threads are blocked on themselves. Any threads which are found to
- * be self-blocked get sent a NonTermination exception.
- *
- * This is only done in a deadlock situation in order to avoid
- * performance overhead in the normal case.
- *
- * Locks: sched_mutex is held upon entry and exit.
- * -------------------------------------------------------------------------- */
+ raiseExceptionHelper
+
+ This function is called by the raise# primitve, just so that we can
+ move some of the tricky bits of raising an exception from C-- into
+ C. Who knows, it might be a useful re-useable thing here too.
+ -------------------------------------------------------------------------- */
-static void
-detectBlackHoles( void )
+StgWord
+raiseExceptionHelper (StgRegTable *reg, StgTSO *tso, StgClosure *exception)
{
- StgTSO *tso = all_threads;
- StgClosure *frame;
- StgClosure *blocked_on;
+ Capability *cap = regTableToCapability(reg);
+ StgThunk *raise_closure = NULL;
+ StgPtr p, next;
StgRetInfoTable *info;
+ //
+ // This closure represents the expression 'raise# E' where E
+ // is the exception raise. It is used to overwrite all the
+ // thunks which are currently under evaluataion.
+ //
- for (tso = all_threads; tso != END_TSO_QUEUE; tso = tso->global_link) {
+ //
+ // 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);
+ //
- while (tso->what_next == ThreadRelocated) {
- tso = tso->link;
- ASSERT(get_itbl(tso)->type == TSO);
- }
-
- if (tso->why_blocked != BlockedOnBlackHole) {
+ //
+ // Walk up the stack, looking for the catch frame. On the way,
+ // we update any closures pointed to from update frames with the
+ // raise closure that we just built.
+ //
+ p = tso->sp;
+ while(1) {
+ info = get_ret_itbl((StgClosure *)p);
+ next = p + stack_frame_sizeW((StgClosure *)p);
+ switch (info->i.type) {
+
+ case UPDATE_FRAME:
+ // Only create raise_closure if we need to.
+ if (raise_closure == NULL) {
+ raise_closure =
+ (StgThunk *)allocateLocal(cap,sizeofW(StgThunk)+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;
}
- 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: ;
+/* -----------------------------------------------------------------------------
+ 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
+ on an MVar, or NonTermination if the thread was blocked on a Black
+ Hole.
+
+ Locks: assumes we hold *all* the capabilities.
+ -------------------------------------------------------------------------- */
+
+void
+resurrectThreads (StgTSO *threads)
+{
+ StgTSO *tso, *next;
+ Capability *cap;
+
+ for (tso = threads; tso != END_TSO_QUEUE; tso = next) {
+ next = tso->global_link;
+ tso->global_link = all_threads;
+ all_threads = tso;
+ IF_DEBUG(scheduler, sched_belch("resurrecting thread %d", tso->id));
+
+ // Wake up the thread on the Capability it was last on for a
+ // bound thread, or last_free_capability otherwise.
+ if (tso->bound) {
+ cap = tso->bound->cap;
+ } else {
+ cap = last_free_capability;
+ }
+
+ switch (tso->why_blocked) {
+ case BlockedOnMVar:
+ case BlockedOnException:
+ /* Called by GC - sched_mutex lock is currently held. */
+ raiseAsync(cap, tso,(StgClosure *)BlockedOnDeadMVar_closure);
+ break;
+ case BlockedOnBlackHole:
+ raiseAsync(cap, tso,(StgClosure *)NonTermination_closure);
+ break;
+ case BlockedOnSTM:
+ raiseAsync(cap, tso,(StgClosure *)BlockedIndefinitely_closure);
+ break;
+ case NotBlocked:
+ /* This might happen if the thread was blocked on a black hole
+ * belonging to a thread that we've just woken up (raiseAsync
+ * can wake up threads, remember...).
+ */
+ continue;
+ default:
+ barf("resurrectThreads: thread blocked in a strange way");
+ }
}
}
* at the Haskell source code level, so enable outside of DEBUG. --sof 7/02]
------------------------------------------------------------------------- */
-static
-void
+#if DEBUG
+static void
printThreadBlockage(StgTSO *tso)
{
switch (tso->why_blocked) {
case BlockedOnRead:
- fprintf(stderr,"is blocked on read from fd %d", tso->block_info.fd);
+ debugBelch("is blocked on read from fd %d", (int)(tso->block_info.fd));
break;
case BlockedOnWrite:
- fprintf(stderr,"is blocked on write to fd %d", tso->block_info.fd);
+ debugBelch("is blocked on write to fd %d", (int)(tso->block_info.fd));
break;
-#if defined(mingw32_TARGET_OS)
+#if defined(mingw32_HOST_OS)
case BlockedOnDoProc:
- fprintf(stderr,"is blocked on proc (request: %d)", tso->block_info.async_result->reqID);
+ debugBelch("is blocked on proc (request: %ld)", tso->block_info.async_result->reqID);
break;
#endif
case BlockedOnDelay:
- fprintf(stderr,"is blocked until %d", tso->block_info.target);
+ debugBelch("is blocked until %ld", (long)(tso->block_info.target));
break;
case BlockedOnMVar:
- fprintf(stderr,"is blocked on an MVar");
+ debugBelch("is blocked on an MVar @ %p", tso->block_info.closure);
break;
case BlockedOnException:
- fprintf(stderr,"is blocked on delivering an exception to thread %d",
+ debugBelch("is blocked on delivering an exception to thread %d",
tso->block_info.tso->id);
break;
case BlockedOnBlackHole:
- fprintf(stderr,"is blocked on a black hole");
+ debugBelch("is blocked on a black hole");
break;
case NotBlocked:
- fprintf(stderr,"is not blocked");
+ debugBelch("is not blocked");
break;
-#if defined(PAR)
+#if defined(PARALLEL_HASKELL)
case BlockedOnGA:
- fprintf(stderr,"is blocked on global address; local FM_BQ is %p (%s)",
+ debugBelch("is blocked on global address; local FM_BQ is %p (%s)",
tso->block_info.closure, info_type(tso->block_info.closure));
break;
case BlockedOnGA_NoSend:
- fprintf(stderr,"is blocked on global address (no send); local FM_BQ is %p (%s)",
+ debugBelch("is blocked on global address (no send); local FM_BQ is %p (%s)",
tso->block_info.closure, info_type(tso->block_info.closure));
break;
#endif
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;
default:
barf("printThreadBlockage: strange tso->why_blocked: %d for TSO %d (%d)",
}
}
-static
void
-printThreadStatus(StgTSO *tso)
+printThreadStatus(StgTSO *t)
{
- switch (tso->what_next) {
- case ThreadKilled:
- fprintf(stderr,"has been killed");
- break;
- case ThreadComplete:
- fprintf(stderr,"has completed");
- break;
- default:
- printThreadBlockage(tso);
- }
+ debugBelch("\tthread %4d @ %p ", t->id, (void *)t);
+ {
+ void *label = lookupThreadLabel(t->id);
+ if (label) debugBelch("[\"%s\"] ",(char *)label);
+ }
+ if (t->what_next == ThreadRelocated) {
+ debugBelch("has been relocated...\n");
+ } else {
+ switch (t->what_next) {
+ case ThreadKilled:
+ debugBelch("has been killed");
+ break;
+ case ThreadComplete:
+ debugBelch("has completed");
+ break;
+ default:
+ printThreadBlockage(t);
+ }
+ debugBelch("\n");
+ }
}
void
printAllThreads(void)
{
- StgTSO *t;
- void *label;
+ StgTSO *t, *next;
+ nat i;
+ Capability *cap;
# if defined(GRAN)
char time_string[TIME_STR_LEN], node_str[NODE_STR_LEN];
ullong_format_string(TIME_ON_PROC(CurrentProc),
time_string, rtsFalse/*no commas!*/);
- 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(t->id);
- if (label) fprintf(stderr,"[\"%s\"] ",(char *)label);
- printThreadStatus(t);
- fprintf(stderr,"\n");
+ for (i = 0; i < n_capabilities; i++) {
+ cap = &capabilities[i];
+ debugBelch("threads on capability %d:\n", cap->no);
+ for (t = cap->run_queue_hd; t != END_TSO_QUEUE; t = t->link) {
+ printThreadStatus(t);
+ }
+ }
+
+ debugBelch("other threads:\n");
+ for (t = all_threads; t != END_TSO_QUEUE; t = next) {
+ if (t->why_blocked != NotBlocked) {
+ printThreadStatus(t);
+ }
+ if (t->what_next == ThreadRelocated) {
+ next = t->link;
+ } else {
+ next = t->global_link;
+ }
}
}
-
-#ifdef DEBUG
+
+// useful from gdb
+void
+printThreadQueue(StgTSO *t)
+{
+ nat i = 0;
+ for (; t != END_TSO_QUEUE; t = t->link) {
+ printThreadStatus(t);
+ i++;
+ }
+ debugBelch("%d threads on queue\n", i);
+}
/*
Print a whole blocking queue attached to node (debugging only).
*/
-# if defined(PAR)
+# if defined(PARALLEL_HASKELL)
void
print_bq (StgClosure *node)
{
StgTSO *tso;
rtsBool end;
- fprintf(stderr,"## BQ of closure %p (%s): ",
+ debugBelch("## BQ of closure %p (%s): ",
node, info_type(node));
/* should cover all closures that may have a blocking queue */
switch (get_itbl(bqe)->type) {
case TSO:
- fprintf(stderr," TSO %u (%x),",
+ debugBelch(" TSO %u (%x),",
((StgTSO *)bqe)->id, ((StgTSO *)bqe));
break;
case BLOCKED_FETCH:
- fprintf(stderr," BF (node=%p, ga=((%x, %d, %x)),",
+ debugBelch(" BF (node=%p, ga=((%x, %d, %x)),",
((StgBlockedFetch *)bqe)->node,
((StgBlockedFetch *)bqe)->ga.payload.gc.gtid,
((StgBlockedFetch *)bqe)->ga.payload.gc.slot,
((StgBlockedFetch *)bqe)->ga.weight);
break;
case CONSTR:
- fprintf(stderr," %s (IP %p),",
+ debugBelch(" %s (IP %p),",
(get_itbl(bqe) == &stg_RBH_Save_0_info ? "RBH_Save_0" :
get_itbl(bqe) == &stg_RBH_Save_1_info ? "RBH_Save_1" :
get_itbl(bqe) == &stg_RBH_Save_2_info ? "RBH_Save_2" :
break;
}
} /* for */
- fputc('\n', stderr);
+ debugBelch("\n");
}
# elif defined(GRAN)
void
ASSERT(node!=(StgClosure*)NULL); // sanity check
node_loc = where_is(node);
- fprintf(stderr,"## BQ of closure %p (%s) on [PE %d]: ",
+ debugBelch("## BQ of closure %p (%s) on [PE %d]: ",
node, info_type(node), node_loc);
/*
tso_loc = where_is((StgClosure *)bqe);
switch (get_itbl(bqe)->type) {
case TSO:
- fprintf(stderr," TSO %d (%p) on [PE %d],",
+ debugBelch(" TSO %d (%p) on [PE %d],",
((StgTSO *)bqe)->id, (StgTSO *)bqe, tso_loc);
break;
case CONSTR:
- fprintf(stderr," %s (IP %p),",
+ debugBelch(" %s (IP %p),",
(get_itbl(bqe) == &stg_RBH_Save_0_info ? "RBH_Save_0" :
get_itbl(bqe) == &stg_RBH_Save_1_info ? "RBH_Save_1" :
get_itbl(bqe) == &stg_RBH_Save_2_info ? "RBH_Save_2" :
break;
}
} /* for */
- fputc('\n', stderr);
-}
-#else
-/*
- Nice and easy: only TSOs on the blocking queue
-*/
-void
-print_bq (StgClosure *node)
-{
- StgTSO *tso;
-
- ASSERT(node!=(StgClosure*)NULL); // sanity check
- for (tso = ((StgBlockingQueue*)node)->blocking_queue;
- tso != END_TSO_QUEUE;
- tso=tso->link) {
- ASSERT(tso!=NULL && tso!=END_TSO_QUEUE); // sanity check
- ASSERT(get_itbl(tso)->type == TSO); // guess what, sanity check
- fprintf(stderr," TSO %d (%p),", tso->id, tso);
- }
- fputc('\n', stderr);
+ debugBelch("\n");
}
# endif
-#if defined(PAR)
+#if defined(PARALLEL_HASKELL)
static nat
run_queue_len(void)
{
- nat i;
- StgTSO *tso;
-
- for (i=0, tso=run_queue_hd;
- tso != END_TSO_QUEUE;
- i++, tso=tso->link)
- /* nothing */
-
- return i;
+ nat i;
+ StgTSO *tso;
+
+ for (i=0, tso=run_queue_hd;
+ tso != END_TSO_QUEUE;
+ i++, tso=tso->link) {
+ /* nothing */
+ }
+
+ return i;
}
#endif
void
sched_belch(char *s, ...)
{
- va_list ap;
- va_start(ap,s);
-#ifdef RTS_SUPPORTS_THREADS
- fprintf(stderr, "sched (task %p): ", osThreadId());
-#elif defined(PAR)
- fprintf(stderr, "== ");
+ va_list ap;
+ va_start(ap,s);
+#ifdef THREADED_RTS
+ debugBelch("sched (task %p): ", (void *)(unsigned long)(unsigned int)osThreadId());
+#elif defined(PARALLEL_HASKELL)
+ debugBelch("== ");
#else
- fprintf(stderr, "sched: ");
+ debugBelch("sched: ");
#endif
- vfprintf(stderr, s, ap);
- fprintf(stderr, "\n");
- fflush(stderr);
- va_end(ap);
+ vdebugBelch(s, ap);
+ debugBelch("\n");
+ va_end(ap);
}
#endif /* DEBUG */
projects / ghc-hetmet.git / blobdiff