1 /* ---------------------------------------------------------------------------
3 * (c) The GHC Team, 1998-2004
7 * Different GHC ways use this scheduler quite differently (see comments below)
8 * Here is the global picture:
10 * WAY Name CPP flag What's it for
11 * --------------------------------------
12 * mp GUM PARALLEL_HASKELL Parallel execution on a distrib. memory machine
13 * s SMP SMP Parallel execution on a shared memory machine
14 * mg GranSim GRAN Simulation of parallel execution
15 * md GUM/GdH DIST Distributed execution (based on GUM)
17 * --------------------------------------------------------------------------*/
20 * Version with support for distributed memory parallelism aka GUM (WAY=mp):
22 The main scheduling loop in GUM iterates until a finish message is received.
23 In that case a global flag @receivedFinish@ is set and this instance of
24 the RTS shuts down. See ghc/rts/parallel/HLComms.c:processMessages()
25 for the handling of incoming messages, such as PP_FINISH.
26 Note that in the parallel case we have a system manager that coordinates
27 different PEs, each of which are running one instance of the RTS.
28 See ghc/rts/parallel/SysMan.c for the main routine of the parallel program.
29 From this routine processes executing ghc/rts/Main.c are spawned. -- HWL
31 * Version with support for simulating parallel execution aka GranSim (WAY=mg):
33 The main scheduling code in GranSim is quite different from that in std
34 (concurrent) Haskell: while concurrent Haskell just iterates over the
35 threads in the runnable queue, GranSim is event driven, i.e. it iterates
36 over the events in the global event queue. -- HWL
39 #include "PosixSource.h"
44 #include "BlockAlloc.h"
45 #include "OSThreads.h"
49 #define COMPILING_SCHEDULER
51 #include "StgMiscClosures.h"
52 #include "Interpreter.h"
53 #include "Exception.h"
61 #include "ThreadLabels.h"
62 #include "LdvProfile.h"
65 #include "Proftimer.h"
68 #if defined(GRAN) || defined(PARALLEL_HASKELL)
69 # include "GranSimRts.h"
71 # include "ParallelRts.h"
72 # include "Parallel.h"
73 # include "ParallelDebug.h"
78 #include "Capability.h"
81 #ifdef HAVE_SYS_TYPES_H
82 #include <sys/types.h>
96 // Turn off inlining when debugging - it obfuscates things
99 # define STATIC_INLINE static
103 #define USED_IN_THREADED_RTS
105 #define USED_IN_THREADED_RTS STG_UNUSED
108 #ifdef RTS_SUPPORTS_THREADS
109 #define USED_WHEN_RTS_SUPPORTS_THREADS
111 #define USED_WHEN_RTS_SUPPORTS_THREADS STG_UNUSED
114 /* Main thread queue.
115 * Locks required: sched_mutex.
117 StgMainThread *main_threads = NULL;
121 StgTSO* ActiveTSO = NULL; /* for assigning system costs; GranSim-Light only */
122 /* rtsTime TimeOfNextEvent, EndOfTimeSlice; now in GranSim.c */
125 In GranSim we have a runnable and a blocked queue for each processor.
126 In order to minimise code changes new arrays run_queue_hds/tls
127 are created. run_queue_hd is then a short cut (macro) for
128 run_queue_hds[CurrentProc] (see GranSim.h).
131 StgTSO *run_queue_hds[MAX_PROC], *run_queue_tls[MAX_PROC];
132 StgTSO *blocked_queue_hds[MAX_PROC], *blocked_queue_tls[MAX_PROC];
133 StgTSO *ccalling_threadss[MAX_PROC];
134 /* We use the same global list of threads (all_threads) in GranSim as in
135 the std RTS (i.e. we are cheating). However, we don't use this list in
136 the GranSim specific code at the moment (so we are only potentially
142 * Locks required: sched_mutex.
144 StgTSO *run_queue_hd = NULL;
145 StgTSO *run_queue_tl = NULL;
146 StgTSO *blocked_queue_hd = NULL;
147 StgTSO *blocked_queue_tl = NULL;
148 StgTSO *blackhole_queue = NULL;
149 StgTSO *sleeping_queue = NULL; /* perhaps replace with a hash table? */
153 /* The blackhole_queue should be checked for threads to wake up. See
154 * Schedule.h for more thorough comment.
156 rtsBool blackholes_need_checking = rtsFalse;
158 /* Linked list of all threads.
159 * Used for detecting garbage collected threads.
161 StgTSO *all_threads = NULL;
163 /* When a thread performs a safe C call (_ccall_GC, using old
164 * terminology), it gets put on the suspended_ccalling_threads
165 * list. Used by the garbage collector.
167 static StgTSO *suspended_ccalling_threads;
169 /* KH: The following two flags are shared memory locations. There is no need
170 to lock them, since they are only unset at the end of a scheduler
174 /* flag set by signal handler to precipitate a context switch */
175 int context_switch = 0;
177 /* flag that tracks whether we have done any execution in this time slice. */
178 nat recent_activity = ACTIVITY_YES;
180 /* if this flag is set as well, give up execution */
181 rtsBool interrupted = rtsFalse;
183 /* Next thread ID to allocate.
184 * Locks required: thread_id_mutex
186 static StgThreadID next_thread_id = 1;
189 * Pointers to the state of the current thread.
190 * Rule of thumb: if CurrentTSO != NULL, then we're running a Haskell
191 * thread. If CurrentTSO == NULL, then we're at the scheduler level.
194 /* The smallest stack size that makes any sense is:
195 * RESERVED_STACK_WORDS (so we can get back from the stack overflow)
196 * + sizeofW(StgStopFrame) (the stg_stop_thread_info frame)
197 * + 1 (the closure to enter)
199 * + 1 (spare slot req'd by stg_ap_v_ret)
201 * A thread with this stack will bomb immediately with a stack
202 * overflow, which will increase its stack size.
205 #define MIN_STACK_WORDS (RESERVED_STACK_WORDS + sizeofW(StgStopFrame) + 3)
212 /* This is used in `TSO.h' and gcc 2.96 insists that this variable actually
213 * exists - earlier gccs apparently didn't.
219 * Set to TRUE when entering a shutdown state (via shutdownHaskellAndExit()) --
220 * in an MT setting, needed to signal that a worker thread shouldn't hang around
221 * in the scheduler when it is out of work.
223 static rtsBool shutting_down_scheduler = rtsFalse;
225 #if defined(RTS_SUPPORTS_THREADS)
226 /* ToDo: carefully document the invariants that go together
227 * with these synchronisation objects.
229 Mutex sched_mutex = INIT_MUTEX_VAR;
230 Mutex term_mutex = INIT_MUTEX_VAR;
232 #endif /* RTS_SUPPORTS_THREADS */
234 #if defined(PARALLEL_HASKELL)
236 rtsTime TimeOfLastYield;
237 rtsBool emitSchedule = rtsTrue;
241 static char *whatNext_strs[] = {
251 /* -----------------------------------------------------------------------------
252 * static function prototypes
253 * -------------------------------------------------------------------------- */
255 #if defined(RTS_SUPPORTS_THREADS)
256 static void taskStart(void);
259 static void schedule( StgMainThread *mainThread USED_WHEN_RTS_SUPPORTS_THREADS,
260 Capability *initialCapability );
263 // These function all encapsulate parts of the scheduler loop, and are
264 // abstracted only to make the structure and control flow of the
265 // scheduler clearer.
267 static void schedulePreLoop(void);
268 static void scheduleStartSignalHandlers(void);
269 static void scheduleCheckBlockedThreads(void);
270 static void scheduleCheckBlackHoles(void);
271 static void scheduleDetectDeadlock(void);
273 static StgTSO *scheduleProcessEvent(rtsEvent *event);
275 #if defined(PARALLEL_HASKELL)
276 static StgTSO *scheduleSendPendingMessages(void);
277 static void scheduleActivateSpark(void);
278 static rtsBool scheduleGetRemoteWork(rtsBool *receivedFinish);
280 #if defined(PAR) || defined(GRAN)
281 static void scheduleGranParReport(void);
283 static void schedulePostRunThread(void);
284 static rtsBool scheduleHandleHeapOverflow( Capability *cap, StgTSO *t );
285 static void scheduleHandleStackOverflow( StgTSO *t);
286 static rtsBool scheduleHandleYield( StgTSO *t, nat prev_what_next );
287 static void scheduleHandleThreadBlocked( StgTSO *t );
288 static rtsBool scheduleHandleThreadFinished( StgMainThread *mainThread,
289 Capability *cap, StgTSO *t );
290 static rtsBool scheduleDoHeapProfile(rtsBool ready_to_gc);
291 static void scheduleDoGC(rtsBool force_major);
293 static void unblockThread(StgTSO *tso);
294 static rtsBool checkBlackHoles(void);
295 static SchedulerStatus waitThread_(/*out*/StgMainThread* m,
296 Capability *initialCapability
298 static void scheduleThread_ (StgTSO* tso);
299 static void AllRoots(evac_fn evac);
301 static StgTSO *threadStackOverflow(StgTSO *tso);
303 static void raiseAsync_(StgTSO *tso, StgClosure *exception,
304 rtsBool stop_at_atomically);
306 static void printThreadBlockage(StgTSO *tso);
307 static void printThreadStatus(StgTSO *tso);
308 void printThreadQueue(StgTSO *tso);
310 #if defined(PARALLEL_HASKELL)
311 StgTSO * createSparkThread(rtsSpark spark);
312 StgTSO * activateSpark (rtsSpark spark);
315 /* ----------------------------------------------------------------------------
317 * ------------------------------------------------------------------------- */
319 #if defined(RTS_SUPPORTS_THREADS)
320 static nat startingWorkerThread = 0;
325 ACQUIRE_LOCK(&sched_mutex);
326 startingWorkerThread--;
329 RELEASE_LOCK(&sched_mutex);
333 startSchedulerTaskIfNecessary(void)
335 if ( !EMPTY_RUN_QUEUE()
336 && !shutting_down_scheduler // not if we're shutting down
337 && startingWorkerThread==0)
339 // we don't want to start another worker thread
340 // just because the last one hasn't yet reached the
341 // "waiting for capability" state
342 startingWorkerThread++;
343 if (!maybeStartNewWorker(taskStart)) {
344 startingWorkerThread--;
350 /* -----------------------------------------------------------------------------
351 * Putting a thread on the run queue: different scheduling policies
352 * -------------------------------------------------------------------------- */
355 addToRunQueue( StgTSO *t )
357 #if defined(PARALLEL_HASKELL)
358 if (RtsFlags.ParFlags.doFairScheduling) {
359 // this does round-robin scheduling; good for concurrency
360 APPEND_TO_RUN_QUEUE(t);
362 // this does unfair scheduling; good for parallelism
363 PUSH_ON_RUN_QUEUE(t);
366 // this does round-robin scheduling; good for concurrency
367 APPEND_TO_RUN_QUEUE(t);
371 /* ---------------------------------------------------------------------------
372 Main scheduling loop.
374 We use round-robin scheduling, each thread returning to the
375 scheduler loop when one of these conditions is detected:
378 * timer expires (thread yields)
383 Locking notes: we acquire the scheduler lock once at the beginning
384 of the scheduler loop, and release it when
386 * running a thread, or
387 * waiting for work, or
388 * waiting for a GC to complete.
391 In a GranSim setup this loop iterates over the global event queue.
392 This revolves around the global event queue, which determines what
393 to do next. Therefore, it's more complicated than either the
394 concurrent or the parallel (GUM) setup.
397 GUM iterates over incoming messages.
398 It starts with nothing to do (thus CurrentTSO == END_TSO_QUEUE),
399 and sends out a fish whenever it has nothing to do; in-between
400 doing the actual reductions (shared code below) it processes the
401 incoming messages and deals with delayed operations
402 (see PendingFetches).
403 This is not the ugliest code you could imagine, but it's bloody close.
405 ------------------------------------------------------------------------ */
408 schedule( StgMainThread *mainThread USED_WHEN_RTS_SUPPORTS_THREADS,
409 Capability *initialCapability )
413 StgThreadReturnCode ret;
416 #elif defined(PARALLEL_HASKELL)
419 rtsBool receivedFinish = rtsFalse;
421 nat tp_size, sp_size; // stats only
427 // Pre-condition: sched_mutex is held.
428 // We might have a capability, passed in as initialCapability.
429 cap = initialCapability;
431 #if !defined(RTS_SUPPORTS_THREADS)
432 // simply initialise it in the non-threaded case
433 grabCapability(&cap);
437 sched_belch("### NEW SCHEDULER LOOP (main thr: %p, cap: %p)",
438 mainThread, initialCapability);
443 // -----------------------------------------------------------
444 // Scheduler loop starts here:
446 #if defined(PARALLEL_HASKELL)
447 #define TERMINATION_CONDITION (!receivedFinish)
449 #define TERMINATION_CONDITION ((event = get_next_event()) != (rtsEvent*)NULL)
451 #define TERMINATION_CONDITION rtsTrue
454 while (TERMINATION_CONDITION) {
457 /* Choose the processor with the next event */
458 CurrentProc = event->proc;
459 CurrentTSO = event->tso;
462 #if defined(RTS_SUPPORTS_THREADS)
463 // Yield the capability to higher-priority tasks if necessary.
466 yieldCapability(&cap,
467 mainThread ? &mainThread->bound_thread_cond : NULL );
470 // If we do not currently hold a capability, we wait for one
473 waitForCapability(&sched_mutex, &cap,
474 mainThread ? &mainThread->bound_thread_cond : NULL);
477 // We now have a capability...
480 #if 0 /* extra sanity checking */
483 for (m = main_threads; m != NULL; m = m->link) {
484 ASSERT(get_itbl(m->tso)->type == TSO);
489 // Check whether we have re-entered the RTS from Haskell without
490 // going via suspendThread()/resumeThread (i.e. a 'safe' foreign
492 if (cap->r.rInHaskell) {
493 errorBelch("schedule: re-entered unsafely.\n"
494 " Perhaps a 'foreign import unsafe' should be 'safe'?");
499 // Test for interruption. If interrupted==rtsTrue, then either
500 // we received a keyboard interrupt (^C), or the scheduler is
501 // trying to shut down all the tasks (shutting_down_scheduler) in
505 if (shutting_down_scheduler) {
506 IF_DEBUG(scheduler, sched_belch("shutting down"));
507 releaseCapability(cap);
509 mainThread->stat = Interrupted;
510 mainThread->ret = NULL;
514 IF_DEBUG(scheduler, sched_belch("interrupted"));
519 #if defined(not_yet) && defined(SMP)
521 // Top up the run queue from our spark pool. We try to make the
522 // number of threads in the run queue equal to the number of
523 // free capabilities.
527 if (EMPTY_RUN_QUEUE()) {
528 spark = findSpark(rtsFalse);
530 break; /* no more sparks in the pool */
532 createSparkThread(spark);
534 sched_belch("==^^ turning spark of closure %p into a thread",
535 (StgClosure *)spark));
541 scheduleStartSignalHandlers();
543 // Only check the black holes here if we've nothing else to do.
544 // During normal execution, the black hole list only gets checked
545 // at GC time, to avoid repeatedly traversing this possibly long
546 // list each time around the scheduler.
547 if (EMPTY_RUN_QUEUE()) { scheduleCheckBlackHoles(); }
549 scheduleCheckBlockedThreads();
551 scheduleDetectDeadlock();
553 // Normally, the only way we can get here with no threads to
554 // run is if a keyboard interrupt received during
555 // scheduleCheckBlockedThreads() or scheduleDetectDeadlock().
556 // Additionally, it is not fatal for the
557 // threaded RTS to reach here with no threads to run.
559 // win32: might be here due to awaitEvent() being abandoned
560 // as a result of a console event having been delivered.
561 if ( EMPTY_RUN_QUEUE() ) {
562 #if !defined(RTS_SUPPORTS_THREADS) && !defined(mingw32_HOST_OS)
565 continue; // nothing to do
568 #if defined(PARALLEL_HASKELL)
569 scheduleSendPendingMessages();
570 if (EMPTY_RUN_QUEUE() && scheduleActivateSpark())
574 ASSERT(next_fish_to_send_at==0); // i.e. no delayed fishes left!
577 /* If we still have no work we need to send a FISH to get a spark
579 if (EMPTY_RUN_QUEUE()) {
580 if (!scheduleGetRemoteWork(&receivedFinish)) continue;
581 ASSERT(rtsFalse); // should not happen at the moment
583 // from here: non-empty run queue.
584 // TODO: merge above case with this, only one call processMessages() !
585 if (PacketsWaiting()) { /* process incoming messages, if
586 any pending... only in else
587 because getRemoteWork waits for
589 receivedFinish = processMessages();
594 scheduleProcessEvent(event);
598 // Get a thread to run
600 ASSERT(run_queue_hd != END_TSO_QUEUE);
603 #if defined(GRAN) || defined(PAR)
604 scheduleGranParReport(); // some kind of debuging output
606 // Sanity check the thread we're about to run. This can be
607 // expensive if there is lots of thread switching going on...
608 IF_DEBUG(sanity,checkTSO(t));
611 #if defined(RTS_SUPPORTS_THREADS)
612 // Check whether we can run this thread in the current task.
613 // If not, we have to pass our capability to the right task.
615 StgMainThread *m = t->main;
622 sched_belch("### Running thread %d in bound thread", t->id));
623 // yes, the Haskell thread is bound to the current native thread
628 sched_belch("### thread %d bound to another OS thread", t->id));
629 // no, bound to a different Haskell thread: pass to that thread
630 PUSH_ON_RUN_QUEUE(t);
636 if(mainThread != NULL)
637 // The thread we want to run is unbound.
640 sched_belch("### this OS thread cannot run thread %d", t->id));
641 // no, the current native thread is bound to a different
642 // Haskell thread, so pass it to any worker thread
643 PUSH_ON_RUN_QUEUE(t);
650 cap->r.rCurrentTSO = t;
652 /* context switches are now initiated by the timer signal, unless
653 * the user specified "context switch as often as possible", with
656 if ((RtsFlags.ConcFlags.ctxtSwitchTicks == 0
657 && (run_queue_hd != END_TSO_QUEUE
658 || blocked_queue_hd != END_TSO_QUEUE
659 || sleeping_queue != END_TSO_QUEUE)))
664 RELEASE_LOCK(&sched_mutex);
666 IF_DEBUG(scheduler, sched_belch("-->> running thread %ld %s ...",
667 (long)t->id, whatNext_strs[t->what_next]));
669 #if defined(PROFILING)
670 startHeapProfTimer();
673 // ----------------------------------------------------------------------
674 // Run the current thread
676 prev_what_next = t->what_next;
678 errno = t->saved_errno;
679 cap->r.rInHaskell = rtsTrue;
681 recent_activity = ACTIVITY_YES;
683 switch (prev_what_next) {
687 /* Thread already finished, return to scheduler. */
688 ret = ThreadFinished;
692 ret = StgRun((StgFunPtr) stg_returnToStackTop, &cap->r);
695 case ThreadInterpret:
696 ret = interpretBCO(cap);
700 barf("schedule: invalid what_next field");
704 // in SMP mode, we might return with a different capability than
705 // we started with, if the Haskell thread made a foreign call. So
706 // let's find out what our current Capability is:
707 cap = myCapability();
710 cap->r.rInHaskell = rtsFalse;
712 // The TSO might have moved, eg. if it re-entered the RTS and a GC
713 // happened. So find the new location:
714 t = cap->r.rCurrentTSO;
716 // And save the current errno in this thread.
717 t->saved_errno = errno;
719 // ----------------------------------------------------------------------
721 /* Costs for the scheduler are assigned to CCS_SYSTEM */
722 #if defined(PROFILING)
727 ACQUIRE_LOCK(&sched_mutex);
729 // We have run some Haskell code: there might be blackhole-blocked
730 // threads to wake up now.
731 if ( blackhole_queue != END_TSO_QUEUE ) {
732 blackholes_need_checking = rtsTrue;
735 #if defined(RTS_SUPPORTS_THREADS)
736 IF_DEBUG(scheduler,debugBelch("sched (task %p): ", osThreadId()););
737 #elif !defined(GRAN) && !defined(PARALLEL_HASKELL)
738 IF_DEBUG(scheduler,debugBelch("sched: "););
741 schedulePostRunThread();
743 ready_to_gc = rtsFalse;
747 ready_to_gc = scheduleHandleHeapOverflow(cap,t);
751 scheduleHandleStackOverflow(t);
755 if (scheduleHandleYield(t, prev_what_next)) {
756 // shortcut for switching between compiler/interpreter:
762 scheduleHandleThreadBlocked(t);
766 if (scheduleHandleThreadFinished(mainThread, cap, t)) return;;
770 barf("schedule: invalid thread return code %d", (int)ret);
773 if (scheduleDoHeapProfile(ready_to_gc)) { ready_to_gc = rtsFalse; }
774 if (ready_to_gc) { scheduleDoGC(rtsFalse); }
775 } /* end of while() */
777 IF_PAR_DEBUG(verbose,
778 debugBelch("== Leaving schedule() after having received Finish\n"));
781 /* ----------------------------------------------------------------------------
782 * Setting up the scheduler loop
783 * ASSUMES: sched_mutex
784 * ------------------------------------------------------------------------- */
787 schedulePreLoop(void)
790 /* set up first event to get things going */
791 /* ToDo: assign costs for system setup and init MainTSO ! */
792 new_event(CurrentProc, CurrentProc, CurrentTime[CurrentProc],
794 CurrentTSO, (StgClosure*)NULL, (rtsSpark*)NULL);
797 debugBelch("GRAN: Init CurrentTSO (in schedule) = %p\n",
799 G_TSO(CurrentTSO, 5));
801 if (RtsFlags.GranFlags.Light) {
802 /* Save current time; GranSim Light only */
803 CurrentTSO->gran.clock = CurrentTime[CurrentProc];
808 /* ----------------------------------------------------------------------------
809 * Start any pending signal handlers
810 * ASSUMES: sched_mutex
811 * ------------------------------------------------------------------------- */
814 scheduleStartSignalHandlers(void)
816 #if defined(RTS_USER_SIGNALS) && !defined(RTS_SUPPORTS_THREADS)
817 if (signals_pending()) {
818 RELEASE_LOCK(&sched_mutex); /* ToDo: kill */
819 startSignalHandlers();
820 ACQUIRE_LOCK(&sched_mutex);
825 /* ----------------------------------------------------------------------------
826 * Check for blocked threads that can be woken up.
827 * ASSUMES: sched_mutex
828 * ------------------------------------------------------------------------- */
831 scheduleCheckBlockedThreads(void)
834 // Check whether any waiting threads need to be woken up. If the
835 // run queue is empty, and there are no other tasks running, we
836 // can wait indefinitely for something to happen.
838 if ( !EMPTY_QUEUE(blocked_queue_hd) || !EMPTY_QUEUE(sleeping_queue) )
840 #if defined(RTS_SUPPORTS_THREADS)
841 // We shouldn't be here...
842 barf("schedule: awaitEvent() in threaded RTS");
844 awaitEvent( EMPTY_RUN_QUEUE() && !blackholes_need_checking );
850 /* ----------------------------------------------------------------------------
851 * Check for threads blocked on BLACKHOLEs that can be woken up
852 * ASSUMES: sched_mutex
853 * ------------------------------------------------------------------------- */
855 scheduleCheckBlackHoles( void )
857 if ( blackholes_need_checking )
860 blackholes_need_checking = rtsFalse;
864 /* ----------------------------------------------------------------------------
865 * Detect deadlock conditions and attempt to resolve them.
866 * ASSUMES: sched_mutex
867 * ------------------------------------------------------------------------- */
870 scheduleDetectDeadlock()
873 #if defined(PARALLEL_HASKELL)
874 // ToDo: add deadlock detection in GUM (similar to SMP) -- HWL
879 * Detect deadlock: when we have no threads to run, there are no
880 * threads blocked, waiting for I/O, or sleeping, and all the
881 * other tasks are waiting for work, we must have a deadlock of
884 if ( EMPTY_THREAD_QUEUES() )
886 #if defined(RTS_SUPPORTS_THREADS)
888 * In the threaded RTS, we only check for deadlock if there
889 * has been no activity in a complete timeslice. This means
890 * we won't eagerly start a full GC just because we don't have
891 * any threads to run currently.
893 if (recent_activity != ACTIVITY_INACTIVE) return;
896 IF_DEBUG(scheduler, sched_belch("deadlocked, forcing major GC..."));
898 // Garbage collection can release some new threads due to
899 // either (a) finalizers or (b) threads resurrected because
900 // they are unreachable and will therefore be sent an
901 // exception. Any threads thus released will be immediately
904 scheduleDoGC( rtsTrue/*force major GC*/ );
905 recent_activity = ACTIVITY_DONE_GC;
906 if ( !EMPTY_RUN_QUEUE() ) return;
908 #if defined(RTS_USER_SIGNALS) && !defined(RTS_SUPPORTS_THREADS)
909 /* If we have user-installed signal handlers, then wait
910 * for signals to arrive rather then bombing out with a
913 if ( anyUserHandlers() ) {
915 sched_belch("still deadlocked, waiting for signals..."));
919 if (signals_pending()) {
920 RELEASE_LOCK(&sched_mutex);
921 startSignalHandlers();
922 ACQUIRE_LOCK(&sched_mutex);
925 // either we have threads to run, or we were interrupted:
926 ASSERT(!EMPTY_RUN_QUEUE() || interrupted);
930 #if !defined(RTS_SUPPORTS_THREADS)
931 /* Probably a real deadlock. Send the current main thread the
932 * Deadlock exception (or in the SMP build, send *all* main
933 * threads the deadlock exception, since none of them can make
939 switch (m->tso->why_blocked) {
941 case BlockedOnBlackHole:
942 case BlockedOnException:
944 raiseAsync(m->tso, (StgClosure *)NonTermination_closure);
947 barf("deadlock: main thread blocked in a strange way");
954 /* ----------------------------------------------------------------------------
955 * Process an event (GRAN only)
956 * ------------------------------------------------------------------------- */
960 scheduleProcessEvent(rtsEvent *event)
964 if (RtsFlags.GranFlags.Light)
965 GranSimLight_enter_system(event, &ActiveTSO); // adjust ActiveTSO etc
967 /* adjust time based on time-stamp */
968 if (event->time > CurrentTime[CurrentProc] &&
969 event->evttype != ContinueThread)
970 CurrentTime[CurrentProc] = event->time;
972 /* Deal with the idle PEs (may issue FindWork or MoveSpark events) */
973 if (!RtsFlags.GranFlags.Light)
976 IF_DEBUG(gran, debugBelch("GRAN: switch by event-type\n"));
978 /* main event dispatcher in GranSim */
979 switch (event->evttype) {
980 /* Should just be continuing execution */
982 IF_DEBUG(gran, debugBelch("GRAN: doing ContinueThread\n"));
983 /* ToDo: check assertion
984 ASSERT(run_queue_hd != (StgTSO*)NULL &&
985 run_queue_hd != END_TSO_QUEUE);
987 /* Ignore ContinueThreads for fetching threads (if synchr comm) */
988 if (!RtsFlags.GranFlags.DoAsyncFetch &&
989 procStatus[CurrentProc]==Fetching) {
990 debugBelch("ghuH: Spurious ContinueThread while Fetching ignored; TSO %d (%p) [PE %d]\n",
991 CurrentTSO->id, CurrentTSO, CurrentProc);
994 /* Ignore ContinueThreads for completed threads */
995 if (CurrentTSO->what_next == ThreadComplete) {
996 debugBelch("ghuH: found a ContinueThread event for completed thread %d (%p) [PE %d] (ignoring ContinueThread)\n",
997 CurrentTSO->id, CurrentTSO, CurrentProc);
1000 /* Ignore ContinueThreads for threads that are being migrated */
1001 if (PROCS(CurrentTSO)==Nowhere) {
1002 debugBelch("ghuH: trying to run the migrating TSO %d (%p) [PE %d] (ignoring ContinueThread)\n",
1003 CurrentTSO->id, CurrentTSO, CurrentProc);
1006 /* The thread should be at the beginning of the run queue */
1007 if (CurrentTSO!=run_queue_hds[CurrentProc]) {
1008 debugBelch("ghuH: TSO %d (%p) [PE %d] is not at the start of the run_queue when doing a ContinueThread\n",
1009 CurrentTSO->id, CurrentTSO, CurrentProc);
1010 break; // run the thread anyway
1013 new_event(proc, proc, CurrentTime[proc],
1015 (StgTSO*)NULL, (StgClosure*)NULL, (rtsSpark*)NULL);
1017 */ /* Catches superfluous CONTINUEs -- should be unnecessary */
1018 break; // now actually run the thread; DaH Qu'vam yImuHbej
1021 do_the_fetchnode(event);
1022 goto next_thread; /* handle next event in event queue */
1025 do_the_globalblock(event);
1026 goto next_thread; /* handle next event in event queue */
1029 do_the_fetchreply(event);
1030 goto next_thread; /* handle next event in event queue */
1032 case UnblockThread: /* Move from the blocked queue to the tail of */
1033 do_the_unblock(event);
1034 goto next_thread; /* handle next event in event queue */
1036 case ResumeThread: /* Move from the blocked queue to the tail of */
1037 /* the runnable queue ( i.e. Qu' SImqa'lu') */
1038 event->tso->gran.blocktime +=
1039 CurrentTime[CurrentProc] - event->tso->gran.blockedat;
1040 do_the_startthread(event);
1041 goto next_thread; /* handle next event in event queue */
1044 do_the_startthread(event);
1045 goto next_thread; /* handle next event in event queue */
1048 do_the_movethread(event);
1049 goto next_thread; /* handle next event in event queue */
1052 do_the_movespark(event);
1053 goto next_thread; /* handle next event in event queue */
1056 do_the_findwork(event);
1057 goto next_thread; /* handle next event in event queue */
1060 barf("Illegal event type %u\n", event->evttype);
1063 /* This point was scheduler_loop in the old RTS */
1065 IF_DEBUG(gran, debugBelch("GRAN: after main switch\n"));
1067 TimeOfLastEvent = CurrentTime[CurrentProc];
1068 TimeOfNextEvent = get_time_of_next_event();
1069 IgnoreEvents=(TimeOfNextEvent==0); // HWL HACK
1070 // CurrentTSO = ThreadQueueHd;
1072 IF_DEBUG(gran, debugBelch("GRAN: time of next event is: %ld\n",
1075 if (RtsFlags.GranFlags.Light)
1076 GranSimLight_leave_system(event, &ActiveTSO);
1078 EndOfTimeSlice = CurrentTime[CurrentProc]+RtsFlags.GranFlags.time_slice;
1081 debugBelch("GRAN: end of time-slice is %#lx\n", EndOfTimeSlice));
1083 /* in a GranSim setup the TSO stays on the run queue */
1085 /* Take a thread from the run queue. */
1086 POP_RUN_QUEUE(t); // take_off_run_queue(t);
1089 debugBelch("GRAN: About to run current thread, which is\n");
1092 context_switch = 0; // turned on via GranYield, checking events and time slice
1095 DumpGranEvent(GR_SCHEDULE, t));
1097 procStatus[CurrentProc] = Busy;
1101 /* ----------------------------------------------------------------------------
1102 * Send pending messages (PARALLEL_HASKELL only)
1103 * ------------------------------------------------------------------------- */
1105 #if defined(PARALLEL_HASKELL)
1107 scheduleSendPendingMessages(void)
1113 # if defined(PAR) // global Mem.Mgmt., omit for now
1114 if (PendingFetches != END_BF_QUEUE) {
1119 if (RtsFlags.ParFlags.BufferTime) {
1120 // if we use message buffering, we must send away all message
1121 // packets which have become too old...
1127 /* ----------------------------------------------------------------------------
1128 * Activate spark threads (PARALLEL_HASKELL only)
1129 * ------------------------------------------------------------------------- */
1131 #if defined(PARALLEL_HASKELL)
1133 scheduleActivateSpark(void)
1136 ASSERT(EMPTY_RUN_QUEUE());
1137 /* We get here if the run queue is empty and want some work.
1138 We try to turn a spark into a thread, and add it to the run queue,
1139 from where it will be picked up in the next iteration of the scheduler
1143 /* :-[ no local threads => look out for local sparks */
1144 /* the spark pool for the current PE */
1145 pool = &(cap.r.rSparks); // JB: cap = (old) MainCap
1146 if (advisory_thread_count < RtsFlags.ParFlags.maxThreads &&
1147 pool->hd < pool->tl) {
1149 * ToDo: add GC code check that we really have enough heap afterwards!!
1151 * If we're here (no runnable threads) and we have pending
1152 * sparks, we must have a space problem. Get enough space
1153 * to turn one of those pending sparks into a
1157 spark = findSpark(rtsFalse); /* get a spark */
1158 if (spark != (rtsSpark) NULL) {
1159 tso = createThreadFromSpark(spark); /* turn the spark into a thread */
1160 IF_PAR_DEBUG(fish, // schedule,
1161 debugBelch("==== schedule: Created TSO %d (%p); %d threads active\n",
1162 tso->id, tso, advisory_thread_count));
1164 if (tso==END_TSO_QUEUE) { /* failed to activate spark->back to loop */
1165 IF_PAR_DEBUG(fish, // schedule,
1166 debugBelch("==^^ failed to create thread from spark @ %lx\n",
1168 return rtsFalse; /* failed to generate a thread */
1169 } /* otherwise fall through & pick-up new tso */
1171 IF_PAR_DEBUG(fish, // schedule,
1172 debugBelch("==^^ no local sparks (spark pool contains only NFs: %d)\n",
1173 spark_queue_len(pool)));
1174 return rtsFalse; /* failed to generate a thread */
1176 return rtsTrue; /* success in generating a thread */
1177 } else { /* no more threads permitted or pool empty */
1178 return rtsFalse; /* failed to generateThread */
1181 tso = NULL; // avoid compiler warning only
1182 return rtsFalse; /* dummy in non-PAR setup */
1185 #endif // PARALLEL_HASKELL
1187 /* ----------------------------------------------------------------------------
1188 * Get work from a remote node (PARALLEL_HASKELL only)
1189 * ------------------------------------------------------------------------- */
1191 #if defined(PARALLEL_HASKELL)
1193 scheduleGetRemoteWork(rtsBool *receivedFinish)
1195 ASSERT(EMPTY_RUN_QUEUE());
1197 if (RtsFlags.ParFlags.BufferTime) {
1198 IF_PAR_DEBUG(verbose,
1199 debugBelch("...send all pending data,"));
1202 for (i=1; i<=nPEs; i++)
1203 sendImmediately(i); // send all messages away immediately
1207 //++EDEN++ idle() , i.e. send all buffers, wait for work
1208 // suppress fishing in EDEN... just look for incoming messages
1209 // (blocking receive)
1210 IF_PAR_DEBUG(verbose,
1211 debugBelch("...wait for incoming messages...\n"));
1212 *receivedFinish = processMessages(); // blocking receive...
1214 // and reenter scheduling loop after having received something
1215 // (return rtsFalse below)
1217 # else /* activate SPARKS machinery */
1218 /* We get here, if we have no work, tried to activate a local spark, but still
1219 have no work. We try to get a remote spark, by sending a FISH message.
1220 Thread migration should be added here, and triggered when a sequence of
1221 fishes returns without work. */
1222 delay = (RtsFlags.ParFlags.fishDelay!=0ll ? RtsFlags.ParFlags.fishDelay : 0ll);
1224 /* =8-[ no local sparks => look for work on other PEs */
1226 * We really have absolutely no work. Send out a fish
1227 * (there may be some out there already), and wait for
1228 * something to arrive. We clearly can't run any threads
1229 * until a SCHEDULE or RESUME arrives, and so that's what
1230 * we're hoping to see. (Of course, we still have to
1231 * respond to other types of messages.)
1233 rtsTime now = msTime() /*CURRENT_TIME*/;
1234 IF_PAR_DEBUG(verbose,
1235 debugBelch("-- now=%ld\n", now));
1236 IF_PAR_DEBUG(fish, // verbose,
1237 if (outstandingFishes < RtsFlags.ParFlags.maxFishes &&
1238 (last_fish_arrived_at!=0 &&
1239 last_fish_arrived_at+delay > now)) {
1240 debugBelch("--$$ <%llu> delaying FISH until %llu (last fish %llu, delay %llu)\n",
1241 now, last_fish_arrived_at+delay,
1242 last_fish_arrived_at,
1246 if (outstandingFishes < RtsFlags.ParFlags.maxFishes &&
1247 advisory_thread_count < RtsFlags.ParFlags.maxThreads) { // send a FISH, but when?
1248 if (last_fish_arrived_at==0 ||
1249 (last_fish_arrived_at+delay <= now)) { // send FISH now!
1250 /* outstandingFishes is set in sendFish, processFish;
1251 avoid flooding system with fishes via delay */
1252 next_fish_to_send_at = 0;
1254 /* ToDo: this should be done in the main scheduling loop to avoid the
1255 busy wait here; not so bad if fish delay is very small */
1256 int iq = 0; // DEBUGGING -- HWL
1257 next_fish_to_send_at = last_fish_arrived_at+delay; // remember when to send
1258 /* send a fish when ready, but process messages that arrive in the meantime */
1260 if (PacketsWaiting()) {
1262 *receivedFinish = processMessages();
1265 } while (!*receivedFinish || now<next_fish_to_send_at);
1266 // JB: This means the fish could become obsolete, if we receive
1267 // work. Better check for work again?
1268 // last line: while (!receivedFinish || !haveWork || now<...)
1269 // next line: if (receivedFinish || haveWork )
1271 if (*receivedFinish) // no need to send a FISH if we are finishing anyway
1272 return rtsFalse; // NB: this will leave scheduler loop
1273 // immediately after return!
1275 IF_PAR_DEBUG(fish, // verbose,
1276 debugBelch("--$$ <%llu> sent delayed fish (%d processMessages); active/total threads=%d/%d\n",now,iq,run_queue_len(),advisory_thread_count));
1280 // JB: IMHO, this should all be hidden inside sendFish(...)
1282 sendFish(pe, thisPE, NEW_FISH_AGE, NEW_FISH_HISTORY,
1285 // Global statistics: count no. of fishes
1286 if (RtsFlags.ParFlags.ParStats.Global &&
1287 RtsFlags.GcFlags.giveStats > NO_GC_STATS) {
1288 globalParStats.tot_fish_mess++;
1292 /* delayed fishes must have been sent by now! */
1293 next_fish_to_send_at = 0;
1296 *receivedFinish = processMessages();
1297 # endif /* SPARKS */
1300 /* NB: this function always returns rtsFalse, meaning the scheduler
1301 loop continues with the next iteration;
1303 return code means success in finding work; we enter this function
1304 if there is no local work, thus have to send a fish which takes
1305 time until it arrives with work; in the meantime we should process
1306 messages in the main loop;
1309 #endif // PARALLEL_HASKELL
1311 /* ----------------------------------------------------------------------------
1312 * PAR/GRAN: Report stats & debugging info(?)
1313 * ------------------------------------------------------------------------- */
1315 #if defined(PAR) || defined(GRAN)
1317 scheduleGranParReport(void)
1319 ASSERT(run_queue_hd != END_TSO_QUEUE);
1321 /* Take a thread from the run queue, if we have work */
1322 POP_RUN_QUEUE(t); // take_off_run_queue(END_TSO_QUEUE);
1324 /* If this TSO has got its outport closed in the meantime,
1325 * it mustn't be run. Instead, we have to clean it up as if it was finished.
1326 * It has to be marked as TH_DEAD for this purpose.
1327 * If it is TH_TERM instead, it is supposed to have finished in the normal way.
1329 JB: TODO: investigate wether state change field could be nuked
1330 entirely and replaced by the normal tso state (whatnext
1331 field). All we want to do is to kill tsos from outside.
1334 /* ToDo: write something to the log-file
1335 if (RTSflags.ParFlags.granSimStats && !sameThread)
1336 DumpGranEvent(GR_SCHEDULE, RunnableThreadsHd);
1340 /* the spark pool for the current PE */
1341 pool = &(cap.r.rSparks); // cap = (old) MainCap
1344 debugBelch("--=^ %d threads, %d sparks on [%#x]\n",
1345 run_queue_len(), spark_queue_len(pool), CURRENT_PROC));
1348 debugBelch("--=^ %d threads, %d sparks on [%#x]\n",
1349 run_queue_len(), spark_queue_len(pool), CURRENT_PROC));
1351 if (RtsFlags.ParFlags.ParStats.Full &&
1352 (t->par.sparkname != (StgInt)0) && // only log spark generated threads
1353 (emitSchedule || // forced emit
1354 (t && LastTSO && t->id != LastTSO->id))) {
1356 we are running a different TSO, so write a schedule event to log file
1357 NB: If we use fair scheduling we also have to write a deschedule
1358 event for LastTSO; with unfair scheduling we know that the
1359 previous tso has blocked whenever we switch to another tso, so
1360 we don't need it in GUM for now
1362 IF_PAR_DEBUG(fish, // schedule,
1363 debugBelch("____ scheduling spark generated thread %d (%lx) (%lx) via a forced emit\n",t->id,t,t->par.sparkname));
1365 DumpRawGranEvent(CURRENT_PROC, CURRENT_PROC,
1366 GR_SCHEDULE, t, (StgClosure *)NULL, 0, 0);
1367 emitSchedule = rtsFalse;
1372 /* ----------------------------------------------------------------------------
1373 * After running a thread...
1374 * ASSUMES: sched_mutex
1375 * ------------------------------------------------------------------------- */
1378 schedulePostRunThread(void)
1381 /* HACK 675: if the last thread didn't yield, make sure to print a
1382 SCHEDULE event to the log file when StgRunning the next thread, even
1383 if it is the same one as before */
1385 TimeOfLastYield = CURRENT_TIME;
1388 /* some statistics gathering in the parallel case */
1390 #if defined(GRAN) || defined(PAR) || defined(EDEN)
1394 IF_DEBUG(gran, DumpGranEvent(GR_DESCHEDULE, t));
1395 globalGranStats.tot_heapover++;
1397 globalParStats.tot_heapover++;
1404 DumpGranEvent(GR_DESCHEDULE, t));
1405 globalGranStats.tot_stackover++;
1408 // DumpGranEvent(GR_DESCHEDULE, t);
1409 globalParStats.tot_stackover++;
1413 case ThreadYielding:
1416 DumpGranEvent(GR_DESCHEDULE, t));
1417 globalGranStats.tot_yields++;
1420 // DumpGranEvent(GR_DESCHEDULE, t);
1421 globalParStats.tot_yields++;
1428 debugBelch("--<< thread %ld (%p; %s) stopped, blocking on node %p [PE %d] with BQ: ",
1429 t->id, t, whatNext_strs[t->what_next], t->block_info.closure,
1430 (t->block_info.closure==(StgClosure*)NULL ? 99 : where_is(t->block_info.closure)));
1431 if (t->block_info.closure!=(StgClosure*)NULL)
1432 print_bq(t->block_info.closure);
1435 // ??? needed; should emit block before
1437 DumpGranEvent(GR_DESCHEDULE, t));
1438 prune_eventq(t, (StgClosure *)NULL); // prune ContinueThreads for t
1441 ASSERT(procStatus[CurrentProc]==Busy ||
1442 ((procStatus[CurrentProc]==Fetching) &&
1443 (t->block_info.closure!=(StgClosure*)NULL)));
1444 if (run_queue_hds[CurrentProc] == END_TSO_QUEUE &&
1445 !(!RtsFlags.GranFlags.DoAsyncFetch &&
1446 procStatus[CurrentProc]==Fetching))
1447 procStatus[CurrentProc] = Idle;
1450 //++PAR++ blockThread() writes the event (change?)
1454 case ThreadFinished:
1458 barf("parGlobalStats: unknown return code");
1464 /* -----------------------------------------------------------------------------
1465 * Handle a thread that returned to the scheduler with ThreadHeepOverflow
1466 * ASSUMES: sched_mutex
1467 * -------------------------------------------------------------------------- */
1470 scheduleHandleHeapOverflow( Capability *cap, StgTSO *t )
1472 // did the task ask for a large block?
1473 if (cap->r.rHpAlloc > BLOCK_SIZE) {
1474 // if so, get one and push it on the front of the nursery.
1478 blocks = (lnat)BLOCK_ROUND_UP(cap->r.rHpAlloc) / BLOCK_SIZE;
1481 debugBelch("--<< thread %ld (%s) stopped: requesting a large block (size %ld)\n",
1482 (long)t->id, whatNext_strs[t->what_next], blocks));
1484 // don't do this if the nursery is (nearly) full, we'll GC first.
1485 if (cap->r.rCurrentNursery->link != NULL ||
1486 cap->r.rNursery->n_blocks == 1) { // paranoia to prevent infinite loop
1487 // if the nursery has only one block.
1490 bd = allocGroup( blocks );
1492 cap->r.rNursery->n_blocks += blocks;
1494 // link the new group into the list
1495 bd->link = cap->r.rCurrentNursery;
1496 bd->u.back = cap->r.rCurrentNursery->u.back;
1497 if (cap->r.rCurrentNursery->u.back != NULL) {
1498 cap->r.rCurrentNursery->u.back->link = bd;
1501 ASSERT(g0s0->blocks == cap->r.rCurrentNursery &&
1502 g0s0 == cap->r.rNursery);
1504 cap->r.rNursery->blocks = bd;
1506 cap->r.rCurrentNursery->u.back = bd;
1508 // initialise it as a nursery block. We initialise the
1509 // step, gen_no, and flags field of *every* sub-block in
1510 // this large block, because this is easier than making
1511 // sure that we always find the block head of a large
1512 // block whenever we call Bdescr() (eg. evacuate() and
1513 // isAlive() in the GC would both have to do this, at
1517 for (x = bd; x < bd + blocks; x++) {
1518 x->step = cap->r.rNursery;
1524 // This assert can be a killer if the app is doing lots
1525 // of large block allocations.
1526 IF_DEBUG(sanity, checkNurserySanity(cap->r.rNursery));
1528 // now update the nursery to point to the new block
1529 cap->r.rCurrentNursery = bd;
1531 // we might be unlucky and have another thread get on the
1532 // run queue before us and steal the large block, but in that
1533 // case the thread will just end up requesting another large
1535 PUSH_ON_RUN_QUEUE(t);
1536 return rtsFalse; /* not actually GC'ing */
1541 debugBelch("--<< thread %ld (%s) stopped: HeapOverflow\n",
1542 (long)t->id, whatNext_strs[t->what_next]));
1544 ASSERT(!is_on_queue(t,CurrentProc));
1545 #elif defined(PARALLEL_HASKELL)
1546 /* Currently we emit a DESCHEDULE event before GC in GUM.
1547 ToDo: either add separate event to distinguish SYSTEM time from rest
1548 or just nuke this DESCHEDULE (and the following SCHEDULE) */
1549 if (0 && RtsFlags.ParFlags.ParStats.Full) {
1550 DumpRawGranEvent(CURRENT_PROC, CURRENT_PROC,
1551 GR_DESCHEDULE, t, (StgClosure *)NULL, 0, 0);
1552 emitSchedule = rtsTrue;
1556 PUSH_ON_RUN_QUEUE(t);
1558 /* actual GC is done at the end of the while loop in schedule() */
1561 /* -----------------------------------------------------------------------------
1562 * Handle a thread that returned to the scheduler with ThreadStackOverflow
1563 * ASSUMES: sched_mutex
1564 * -------------------------------------------------------------------------- */
1567 scheduleHandleStackOverflow( StgTSO *t)
1569 IF_DEBUG(scheduler,debugBelch("--<< thread %ld (%s) stopped, StackOverflow\n",
1570 (long)t->id, whatNext_strs[t->what_next]));
1571 /* just adjust the stack for this thread, then pop it back
1575 /* enlarge the stack */
1576 StgTSO *new_t = threadStackOverflow(t);
1578 /* This TSO has moved, so update any pointers to it from the
1579 * main thread stack. It better not be on any other queues...
1580 * (it shouldn't be).
1582 if (t->main != NULL) {
1583 t->main->tso = new_t;
1585 PUSH_ON_RUN_QUEUE(new_t);
1589 /* -----------------------------------------------------------------------------
1590 * Handle a thread that returned to the scheduler with ThreadYielding
1591 * ASSUMES: sched_mutex
1592 * -------------------------------------------------------------------------- */
1595 scheduleHandleYield( StgTSO *t, nat prev_what_next )
1597 // Reset the context switch flag. We don't do this just before
1598 // running the thread, because that would mean we would lose ticks
1599 // during GC, which can lead to unfair scheduling (a thread hogs
1600 // the CPU because the tick always arrives during GC). This way
1601 // penalises threads that do a lot of allocation, but that seems
1602 // better than the alternative.
1605 /* put the thread back on the run queue. Then, if we're ready to
1606 * GC, check whether this is the last task to stop. If so, wake
1607 * up the GC thread. getThread will block during a GC until the
1611 if (t->what_next != prev_what_next) {
1612 debugBelch("--<< thread %ld (%s) stopped to switch evaluators\n",
1613 (long)t->id, whatNext_strs[t->what_next]);
1615 debugBelch("--<< thread %ld (%s) stopped, yielding\n",
1616 (long)t->id, whatNext_strs[t->what_next]);
1621 //debugBelch("&& Doing sanity check on yielding TSO %ld.", t->id);
1623 ASSERT(t->link == END_TSO_QUEUE);
1625 // Shortcut if we're just switching evaluators: don't bother
1626 // doing stack squeezing (which can be expensive), just run the
1628 if (t->what_next != prev_what_next) {
1633 ASSERT(!is_on_queue(t,CurrentProc));
1636 //debugBelch("&& Doing sanity check on all ThreadQueues (and their TSOs).");
1637 checkThreadQsSanity(rtsTrue));
1644 /* add a ContinueThread event to actually process the thread */
1645 new_event(CurrentProc, CurrentProc, CurrentTime[CurrentProc],
1647 t, (StgClosure*)NULL, (rtsSpark*)NULL);
1649 debugBelch("GRAN: eventq and runnableq after adding yielded thread to queue again:\n");
1656 /* -----------------------------------------------------------------------------
1657 * Handle a thread that returned to the scheduler with ThreadBlocked
1658 * ASSUMES: sched_mutex
1659 * -------------------------------------------------------------------------- */
1662 scheduleHandleThreadBlocked( StgTSO *t
1663 #if !defined(GRAN) && !defined(DEBUG)
1670 debugBelch("--<< thread %ld (%p; %s) stopped, blocking on node %p [PE %d] with BQ: \n",
1671 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)));
1672 if (t->block_info.closure!=(StgClosure*)NULL) print_bq(t->block_info.closure));
1674 // ??? needed; should emit block before
1676 DumpGranEvent(GR_DESCHEDULE, t));
1677 prune_eventq(t, (StgClosure *)NULL); // prune ContinueThreads for t
1680 ASSERT(procStatus[CurrentProc]==Busy ||
1681 ((procStatus[CurrentProc]==Fetching) &&
1682 (t->block_info.closure!=(StgClosure*)NULL)));
1683 if (run_queue_hds[CurrentProc] == END_TSO_QUEUE &&
1684 !(!RtsFlags.GranFlags.DoAsyncFetch &&
1685 procStatus[CurrentProc]==Fetching))
1686 procStatus[CurrentProc] = Idle;
1690 debugBelch("--<< thread %ld (%p; %s) stopped, blocking on node %p with BQ: \n",
1691 t->id, t, whatNext_strs[t->what_next], t->block_info.closure));
1694 if (t->block_info.closure!=(StgClosure*)NULL)
1695 print_bq(t->block_info.closure));
1697 /* Send a fetch (if BlockedOnGA) and dump event to log file */
1700 /* whatever we schedule next, we must log that schedule */
1701 emitSchedule = rtsTrue;
1705 // We don't need to do anything. The thread is blocked, and it
1706 // has tidied up its stack and placed itself on whatever queue
1707 // it needs to be on.
1710 ASSERT(t->why_blocked != NotBlocked);
1711 // This might not be true under SMP: we don't have
1712 // exclusive access to this TSO, so someone might have
1713 // woken it up by now. This actually happens: try
1714 // conc023 +RTS -N2.
1718 debugBelch("--<< thread %d (%s) stopped: ",
1719 t->id, whatNext_strs[t->what_next]);
1720 printThreadBlockage(t);
1723 /* Only for dumping event to log file
1724 ToDo: do I need this in GranSim, too?
1730 /* -----------------------------------------------------------------------------
1731 * Handle a thread that returned to the scheduler with ThreadFinished
1732 * ASSUMES: sched_mutex
1733 * -------------------------------------------------------------------------- */
1736 scheduleHandleThreadFinished( StgMainThread *mainThread
1737 USED_WHEN_RTS_SUPPORTS_THREADS,
1741 /* Need to check whether this was a main thread, and if so,
1742 * return with the return value.
1744 * We also end up here if the thread kills itself with an
1745 * uncaught exception, see Exception.cmm.
1747 IF_DEBUG(scheduler,debugBelch("--++ thread %d (%s) finished\n",
1748 t->id, whatNext_strs[t->what_next]));
1751 endThread(t, CurrentProc); // clean-up the thread
1752 #elif defined(PARALLEL_HASKELL)
1753 /* For now all are advisory -- HWL */
1754 //if(t->priority==AdvisoryPriority) ??
1755 advisory_thread_count--; // JB: Caution with this counter, buggy!
1758 if(t->dist.priority==RevalPriority)
1762 # if defined(EDENOLD)
1763 // the thread could still have an outport... (BUG)
1764 if (t->eden.outport != -1) {
1765 // delete the outport for the tso which has finished...
1766 IF_PAR_DEBUG(eden_ports,
1767 debugBelch("WARNING: Scheduler removes outport %d for TSO %d.\n",
1768 t->eden.outport, t->id));
1771 // thread still in the process (HEAVY BUG! since outport has just been closed...)
1772 if (t->eden.epid != -1) {
1773 IF_PAR_DEBUG(eden_ports,
1774 debugBelch("WARNING: Scheduler removes TSO %d from process %d .\n",
1775 t->id, t->eden.epid));
1776 removeTSOfromProcess(t);
1781 if (RtsFlags.ParFlags.ParStats.Full &&
1782 !RtsFlags.ParFlags.ParStats.Suppressed)
1783 DumpEndEvent(CURRENT_PROC, t, rtsFalse /* not mandatory */);
1785 // t->par only contains statistics: left out for now...
1787 debugBelch("**** end thread: ended sparked thread %d (%lx); sparkname: %lx\n",
1788 t->id,t,t->par.sparkname));
1790 #endif // PARALLEL_HASKELL
1793 // Check whether the thread that just completed was a main
1794 // thread, and if so return with the result.
1796 // There is an assumption here that all thread completion goes
1797 // through this point; we need to make sure that if a thread
1798 // ends up in the ThreadKilled state, that it stays on the run
1799 // queue so it can be dealt with here.
1802 #if defined(RTS_SUPPORTS_THREADS)
1805 mainThread->tso == t
1809 // We are a bound thread: this must be our thread that just
1811 ASSERT(mainThread->tso == t);
1813 if (t->what_next == ThreadComplete) {
1814 if (mainThread->ret) {
1815 // NOTE: return val is tso->sp[1] (see StgStartup.hc)
1816 *(mainThread->ret) = (StgClosure *)mainThread->tso->sp[1];
1818 mainThread->stat = Success;
1820 if (mainThread->ret) {
1821 *(mainThread->ret) = NULL;
1824 mainThread->stat = Interrupted;
1826 mainThread->stat = Killed;
1830 removeThreadLabel((StgWord)mainThread->tso->id);
1832 if (mainThread->prev == NULL) {
1833 ASSERT(mainThread == main_threads);
1834 main_threads = mainThread->link;
1836 mainThread->prev->link = mainThread->link;
1838 if (mainThread->link != NULL) {
1839 mainThread->link->prev = mainThread->prev;
1841 releaseCapability(cap);
1842 return rtsTrue; // tells schedule() to return
1845 #ifdef RTS_SUPPORTS_THREADS
1846 ASSERT(t->main == NULL);
1848 if (t->main != NULL) {
1849 // Must be a main thread that is not the topmost one. Leave
1850 // it on the run queue until the stack has unwound to the
1851 // point where we can deal with this. Leaving it on the run
1852 // queue also ensures that the garbage collector knows about
1853 // this thread and its return value (it gets dropped from the
1854 // all_threads list so there's no other way to find it).
1855 APPEND_TO_RUN_QUEUE(t);
1861 /* -----------------------------------------------------------------------------
1862 * Perform a heap census, if PROFILING
1863 * -------------------------------------------------------------------------- */
1866 scheduleDoHeapProfile( rtsBool ready_to_gc STG_UNUSED )
1868 #if defined(PROFILING)
1869 // When we have +RTS -i0 and we're heap profiling, do a census at
1870 // every GC. This lets us get repeatable runs for debugging.
1871 if (performHeapProfile ||
1872 (RtsFlags.ProfFlags.profileInterval==0 &&
1873 RtsFlags.ProfFlags.doHeapProfile && ready_to_gc)) {
1874 GarbageCollect(GetRoots, rtsTrue);
1876 performHeapProfile = rtsFalse;
1877 return rtsTrue; // true <=> we already GC'd
1883 /* -----------------------------------------------------------------------------
1884 * Perform a garbage collection if necessary
1885 * ASSUMES: sched_mutex
1886 * -------------------------------------------------------------------------- */
1889 scheduleDoGC( rtsBool force_major )
1894 static rtsBool waiting_for_gc;
1895 int n_capabilities = RtsFlags.ParFlags.nNodes - 1;
1896 // subtract one because we're already holding one.
1897 Capability *caps[n_capabilities];
1901 // In order to GC, there must be no threads running Haskell code.
1902 // Therefore, the GC thread needs to hold *all* the capabilities,
1903 // and release them after the GC has completed.
1905 // This seems to be the simplest way: previous attempts involved
1906 // making all the threads with capabilities give up their
1907 // capabilities and sleep except for the *last* one, which
1908 // actually did the GC. But it's quite hard to arrange for all
1909 // the other tasks to sleep and stay asleep.
1911 // This does mean that there will be multiple entries in the
1912 // thread->capability hash table for the current thread, but
1913 // they will be removed as normal when the capabilities are
1917 // Someone else is already trying to GC
1918 if (waiting_for_gc) return;
1919 waiting_for_gc = rtsTrue;
1921 while (n_capabilities > 0) {
1922 IF_DEBUG(scheduler, sched_belch("ready_to_gc, grabbing all the capabilies (%d left)", n_capabilities));
1923 waitForReturnCapability(&sched_mutex, &cap);
1925 caps[n_capabilities] = cap;
1928 waiting_for_gc = rtsFalse;
1931 /* Kick any transactions which are invalid back to their
1932 * atomically frames. When next scheduled they will try to
1933 * commit, this commit will fail and they will retry.
1938 for (t = all_threads; t != END_TSO_QUEUE; t = next) {
1939 if (t->what_next == ThreadRelocated) {
1942 next = t->global_link;
1943 if (t -> trec != NO_TREC && t -> why_blocked == NotBlocked) {
1944 if (!stmValidateNestOfTransactions (t -> trec)) {
1945 IF_DEBUG(stm, sched_belch("trec %p found wasting its time", t));
1947 // strip the stack back to the ATOMICALLY_FRAME, aborting
1948 // the (nested) transaction, and saving the stack of any
1949 // partially-evaluated thunks on the heap.
1950 raiseAsync_(t, NULL, rtsTrue);
1953 ASSERT(get_itbl((StgClosure *)t->sp)->type == ATOMICALLY_FRAME);
1961 // so this happens periodically:
1962 scheduleCheckBlackHoles();
1964 IF_DEBUG(scheduler, printAllThreads());
1966 /* everybody back, start the GC.
1967 * Could do it in this thread, or signal a condition var
1968 * to do it in another thread. Either way, we need to
1969 * broadcast on gc_pending_cond afterward.
1971 #if defined(RTS_SUPPORTS_THREADS)
1972 IF_DEBUG(scheduler,sched_belch("doing GC"));
1974 GarbageCollect(GetRoots, force_major);
1978 // release our stash of capabilities.
1980 for (i = 0; i < RtsFlags.ParFlags.nNodes-1; i++) {
1981 releaseCapability(caps[i]);
1987 /* add a ContinueThread event to continue execution of current thread */
1988 new_event(CurrentProc, CurrentProc, CurrentTime[CurrentProc],
1990 t, (StgClosure*)NULL, (rtsSpark*)NULL);
1992 debugBelch("GRAN: eventq and runnableq after Garbage collection:\n\n");
1998 /* ---------------------------------------------------------------------------
1999 * rtsSupportsBoundThreads(): is the RTS built to support bound threads?
2000 * used by Control.Concurrent for error checking.
2001 * ------------------------------------------------------------------------- */
2004 rtsSupportsBoundThreads(void)
2006 #if defined(RTS_SUPPORTS_THREADS)
2013 /* ---------------------------------------------------------------------------
2014 * isThreadBound(tso): check whether tso is bound to an OS thread.
2015 * ------------------------------------------------------------------------- */
2018 isThreadBound(StgTSO* tso USED_IN_THREADED_RTS)
2020 #if defined(RTS_SUPPORTS_THREADS)
2021 return (tso->main != NULL);
2026 /* ---------------------------------------------------------------------------
2027 * Singleton fork(). Do not copy any running threads.
2028 * ------------------------------------------------------------------------- */
2030 #ifndef mingw32_HOST_OS
2031 #define FORKPROCESS_PRIMOP_SUPPORTED
2034 #ifdef FORKPROCESS_PRIMOP_SUPPORTED
2036 deleteThreadImmediately(StgTSO *tso);
2039 forkProcess(HsStablePtr *entry
2040 #ifndef FORKPROCESS_PRIMOP_SUPPORTED
2045 #ifdef FORKPROCESS_PRIMOP_SUPPORTED
2051 IF_DEBUG(scheduler,sched_belch("forking!"));
2052 rts_lock(); // This not only acquires sched_mutex, it also
2053 // makes sure that no other threads are running
2057 if (pid) { /* parent */
2059 /* just return the pid */
2063 } else { /* child */
2066 // delete all threads
2067 run_queue_hd = run_queue_tl = END_TSO_QUEUE;
2069 for (t = all_threads; t != END_TSO_QUEUE; t = next) {
2072 // don't allow threads to catch the ThreadKilled exception
2073 deleteThreadImmediately(t);
2076 // wipe the main thread list
2077 while((m = main_threads) != NULL) {
2078 main_threads = m->link;
2079 # ifdef THREADED_RTS
2080 closeCondition(&m->bound_thread_cond);
2085 rc = rts_evalStableIO(entry, NULL); // run the action
2086 rts_checkSchedStatus("forkProcess",rc);
2090 hs_exit(); // clean up and exit
2093 #else /* !FORKPROCESS_PRIMOP_SUPPORTED */
2094 barf("forkProcess#: primop not supported, sorry!\n");
2099 /* ---------------------------------------------------------------------------
2100 * deleteAllThreads(): kill all the live threads.
2102 * This is used when we catch a user interrupt (^C), before performing
2103 * any necessary cleanups and running finalizers.
2105 * Locks: sched_mutex held.
2106 * ------------------------------------------------------------------------- */
2109 deleteAllThreads ( void )
2112 IF_DEBUG(scheduler,sched_belch("deleting all threads"));
2113 for (t = all_threads; t != END_TSO_QUEUE; t = next) {
2114 if (t->what_next == ThreadRelocated) {
2117 next = t->global_link;
2122 // The run queue now contains a bunch of ThreadKilled threads. We
2123 // must not throw these away: the main thread(s) will be in there
2124 // somewhere, and the main scheduler loop has to deal with it.
2125 // Also, the run queue is the only thing keeping these threads from
2126 // being GC'd, and we don't want the "main thread has been GC'd" panic.
2128 ASSERT(blocked_queue_hd == END_TSO_QUEUE);
2129 ASSERT(blackhole_queue == END_TSO_QUEUE);
2130 ASSERT(sleeping_queue == END_TSO_QUEUE);
2133 /* startThread and insertThread are now in GranSim.c -- HWL */
2136 /* ---------------------------------------------------------------------------
2137 * Suspending & resuming Haskell threads.
2139 * When making a "safe" call to C (aka _ccall_GC), the task gives back
2140 * its capability before calling the C function. This allows another
2141 * task to pick up the capability and carry on running Haskell
2142 * threads. It also means that if the C call blocks, it won't lock
2145 * The Haskell thread making the C call is put to sleep for the
2146 * duration of the call, on the susepended_ccalling_threads queue. We
2147 * give out a token to the task, which it can use to resume the thread
2148 * on return from the C function.
2149 * ------------------------------------------------------------------------- */
2152 suspendThread( StgRegTable *reg )
2156 int saved_errno = errno;
2158 /* assume that *reg is a pointer to the StgRegTable part
2161 cap = (Capability *)((void *)((unsigned char*)reg - sizeof(StgFunTable)));
2163 ACQUIRE_LOCK(&sched_mutex);
2166 sched_belch("thread %d did a _ccall_gc", cap->r.rCurrentTSO->id));
2168 // XXX this might not be necessary --SDM
2169 cap->r.rCurrentTSO->what_next = ThreadRunGHC;
2171 threadPaused(cap->r.rCurrentTSO);
2172 cap->r.rCurrentTSO->link = suspended_ccalling_threads;
2173 suspended_ccalling_threads = cap->r.rCurrentTSO;
2175 if(cap->r.rCurrentTSO->blocked_exceptions == NULL) {
2176 cap->r.rCurrentTSO->why_blocked = BlockedOnCCall;
2177 cap->r.rCurrentTSO->blocked_exceptions = END_TSO_QUEUE;
2179 cap->r.rCurrentTSO->why_blocked = BlockedOnCCall_NoUnblockExc;
2182 /* Use the thread ID as the token; it should be unique */
2183 tok = cap->r.rCurrentTSO->id;
2185 /* Hand back capability */
2186 cap->r.rInHaskell = rtsFalse;
2187 releaseCapability(cap);
2189 #if defined(RTS_SUPPORTS_THREADS)
2190 /* Preparing to leave the RTS, so ensure there's a native thread/task
2191 waiting to take over.
2193 IF_DEBUG(scheduler, sched_belch("worker (token %d): leaving RTS", tok));
2196 RELEASE_LOCK(&sched_mutex);
2198 errno = saved_errno;
2203 resumeThread( StgInt tok )
2205 StgTSO *tso, **prev;
2207 int saved_errno = errno;
2209 #if defined(RTS_SUPPORTS_THREADS)
2210 /* Wait for permission to re-enter the RTS with the result. */
2211 ACQUIRE_LOCK(&sched_mutex);
2212 waitForReturnCapability(&sched_mutex, &cap);
2214 IF_DEBUG(scheduler, sched_belch("worker (token %d): re-entering RTS", tok));
2216 grabCapability(&cap);
2219 /* Remove the thread off of the suspended list */
2220 prev = &suspended_ccalling_threads;
2221 for (tso = suspended_ccalling_threads;
2222 tso != END_TSO_QUEUE;
2223 prev = &tso->link, tso = tso->link) {
2224 if (tso->id == (StgThreadID)tok) {
2229 if (tso == END_TSO_QUEUE) {
2230 barf("resumeThread: thread not found");
2232 tso->link = END_TSO_QUEUE;
2234 if(tso->why_blocked == BlockedOnCCall) {
2235 awakenBlockedQueueNoLock(tso->blocked_exceptions);
2236 tso->blocked_exceptions = NULL;
2239 /* Reset blocking status */
2240 tso->why_blocked = NotBlocked;
2242 cap->r.rCurrentTSO = tso;
2243 cap->r.rInHaskell = rtsTrue;
2244 RELEASE_LOCK(&sched_mutex);
2245 errno = saved_errno;
2249 /* ---------------------------------------------------------------------------
2250 * Comparing Thread ids.
2252 * This is used from STG land in the implementation of the
2253 * instances of Eq/Ord for ThreadIds.
2254 * ------------------------------------------------------------------------ */
2257 cmp_thread(StgPtr tso1, StgPtr tso2)
2259 StgThreadID id1 = ((StgTSO *)tso1)->id;
2260 StgThreadID id2 = ((StgTSO *)tso2)->id;
2262 if (id1 < id2) return (-1);
2263 if (id1 > id2) return 1;
2267 /* ---------------------------------------------------------------------------
2268 * Fetching the ThreadID from an StgTSO.
2270 * This is used in the implementation of Show for ThreadIds.
2271 * ------------------------------------------------------------------------ */
2273 rts_getThreadId(StgPtr tso)
2275 return ((StgTSO *)tso)->id;
2280 labelThread(StgPtr tso, char *label)
2285 /* Caveat: Once set, you can only set the thread name to "" */
2286 len = strlen(label)+1;
2287 buf = stgMallocBytes(len * sizeof(char), "Schedule.c:labelThread()");
2288 strncpy(buf,label,len);
2289 /* Update will free the old memory for us */
2290 updateThreadLabel(((StgTSO *)tso)->id,buf);
2294 /* ---------------------------------------------------------------------------
2295 Create a new thread.
2297 The new thread starts with the given stack size. Before the
2298 scheduler can run, however, this thread needs to have a closure
2299 (and possibly some arguments) pushed on its stack. See
2300 pushClosure() in Schedule.h.
2302 createGenThread() and createIOThread() (in SchedAPI.h) are
2303 convenient packaged versions of this function.
2305 currently pri (priority) is only used in a GRAN setup -- HWL
2306 ------------------------------------------------------------------------ */
2308 /* currently pri (priority) is only used in a GRAN setup -- HWL */
2310 createThread(nat size, StgInt pri)
2313 createThread(nat size)
2319 /* First check whether we should create a thread at all */
2320 #if defined(PARALLEL_HASKELL)
2321 /* check that no more than RtsFlags.ParFlags.maxThreads threads are created */
2322 if (advisory_thread_count >= RtsFlags.ParFlags.maxThreads) {
2324 debugBelch("{createThread}Daq ghuH: refusing to create another thread; no more than %d threads allowed (currently %d)\n",
2325 RtsFlags.ParFlags.maxThreads, advisory_thread_count);
2326 return END_TSO_QUEUE;
2332 ASSERT(!RtsFlags.GranFlags.Light || CurrentProc==0);
2335 // ToDo: check whether size = stack_size - TSO_STRUCT_SIZEW
2337 /* catch ridiculously small stack sizes */
2338 if (size < MIN_STACK_WORDS + TSO_STRUCT_SIZEW) {
2339 size = MIN_STACK_WORDS + TSO_STRUCT_SIZEW;
2342 stack_size = size - TSO_STRUCT_SIZEW;
2344 tso = (StgTSO *)allocate(size);
2345 TICK_ALLOC_TSO(stack_size, 0);
2347 SET_HDR(tso, &stg_TSO_info, CCS_SYSTEM);
2349 SET_GRAN_HDR(tso, ThisPE);
2352 // Always start with the compiled code evaluator
2353 tso->what_next = ThreadRunGHC;
2355 tso->id = next_thread_id++;
2356 tso->why_blocked = NotBlocked;
2357 tso->blocked_exceptions = NULL;
2359 tso->saved_errno = 0;
2362 tso->stack_size = stack_size;
2363 tso->max_stack_size = round_to_mblocks(RtsFlags.GcFlags.maxStkSize)
2365 tso->sp = (P_)&(tso->stack) + stack_size;
2367 tso->trec = NO_TREC;
2370 tso->prof.CCCS = CCS_MAIN;
2373 /* put a stop frame on the stack */
2374 tso->sp -= sizeofW(StgStopFrame);
2375 SET_HDR((StgClosure*)tso->sp,(StgInfoTable *)&stg_stop_thread_info,CCS_SYSTEM);
2376 tso->link = END_TSO_QUEUE;
2380 /* uses more flexible routine in GranSim */
2381 insertThread(tso, CurrentProc);
2383 /* In a non-GranSim setup the pushing of a TSO onto the runq is separated
2389 if (RtsFlags.GranFlags.GranSimStats.Full)
2390 DumpGranEvent(GR_START,tso);
2391 #elif defined(PARALLEL_HASKELL)
2392 if (RtsFlags.ParFlags.ParStats.Full)
2393 DumpGranEvent(GR_STARTQ,tso);
2394 /* HACk to avoid SCHEDULE
2398 /* Link the new thread on the global thread list.
2400 tso->global_link = all_threads;
2404 tso->dist.priority = MandatoryPriority; //by default that is...
2408 tso->gran.pri = pri;
2410 tso->gran.magic = TSO_MAGIC; // debugging only
2412 tso->gran.sparkname = 0;
2413 tso->gran.startedat = CURRENT_TIME;
2414 tso->gran.exported = 0;
2415 tso->gran.basicblocks = 0;
2416 tso->gran.allocs = 0;
2417 tso->gran.exectime = 0;
2418 tso->gran.fetchtime = 0;
2419 tso->gran.fetchcount = 0;
2420 tso->gran.blocktime = 0;
2421 tso->gran.blockcount = 0;
2422 tso->gran.blockedat = 0;
2423 tso->gran.globalsparks = 0;
2424 tso->gran.localsparks = 0;
2425 if (RtsFlags.GranFlags.Light)
2426 tso->gran.clock = Now; /* local clock */
2428 tso->gran.clock = 0;
2430 IF_DEBUG(gran,printTSO(tso));
2431 #elif defined(PARALLEL_HASKELL)
2433 tso->par.magic = TSO_MAGIC; // debugging only
2435 tso->par.sparkname = 0;
2436 tso->par.startedat = CURRENT_TIME;
2437 tso->par.exported = 0;
2438 tso->par.basicblocks = 0;
2439 tso->par.allocs = 0;
2440 tso->par.exectime = 0;
2441 tso->par.fetchtime = 0;
2442 tso->par.fetchcount = 0;
2443 tso->par.blocktime = 0;
2444 tso->par.blockcount = 0;
2445 tso->par.blockedat = 0;
2446 tso->par.globalsparks = 0;
2447 tso->par.localsparks = 0;
2451 globalGranStats.tot_threads_created++;
2452 globalGranStats.threads_created_on_PE[CurrentProc]++;
2453 globalGranStats.tot_sq_len += spark_queue_len(CurrentProc);
2454 globalGranStats.tot_sq_probes++;
2455 #elif defined(PARALLEL_HASKELL)
2456 // collect parallel global statistics (currently done together with GC stats)
2457 if (RtsFlags.ParFlags.ParStats.Global &&
2458 RtsFlags.GcFlags.giveStats > NO_GC_STATS) {
2459 //debugBelch("Creating thread %d @ %11.2f\n", tso->id, usertime());
2460 globalParStats.tot_threads_created++;
2466 sched_belch("==__ schedule: Created TSO %d (%p);",
2467 CurrentProc, tso, tso->id));
2468 #elif defined(PARALLEL_HASKELL)
2469 IF_PAR_DEBUG(verbose,
2470 sched_belch("==__ schedule: Created TSO %d (%p); %d threads active",
2471 (long)tso->id, tso, advisory_thread_count));
2473 IF_DEBUG(scheduler,sched_belch("created thread %ld, stack size = %lx words",
2474 (long)tso->id, (long)tso->stack_size));
2481 all parallel thread creation calls should fall through the following routine.
2484 createThreadFromSpark(rtsSpark spark)
2486 ASSERT(spark != (rtsSpark)NULL);
2487 // JB: TAKE CARE OF THIS COUNTER! BUGGY
2488 if (advisory_thread_count >= RtsFlags.ParFlags.maxThreads)
2490 barf("{createSparkThread}Daq ghuH: refusing to create another thread; no more than %d threads allowed (currently %d)",
2491 RtsFlags.ParFlags.maxThreads, advisory_thread_count);
2492 return END_TSO_QUEUE;
2496 tso = createThread(RtsFlags.GcFlags.initialStkSize);
2497 if (tso==END_TSO_QUEUE)
2498 barf("createSparkThread: Cannot create TSO");
2500 tso->priority = AdvisoryPriority;
2502 pushClosure(tso,spark);
2504 advisory_thread_count++; // JB: TAKE CARE OF THIS COUNTER! BUGGY
2511 Turn a spark into a thread.
2512 ToDo: fix for SMP (needs to acquire SCHED_MUTEX!)
2516 activateSpark (rtsSpark spark)
2520 tso = createSparkThread(spark);
2521 if (RtsFlags.ParFlags.ParStats.Full) {
2522 //ASSERT(run_queue_hd == END_TSO_QUEUE); // I think ...
2523 IF_PAR_DEBUG(verbose,
2524 debugBelch("==^^ activateSpark: turning spark of closure %p (%s) into a thread\n",
2525 (StgClosure *)spark, info_type((StgClosure *)spark)));
2527 // ToDo: fwd info on local/global spark to thread -- HWL
2528 // tso->gran.exported = spark->exported;
2529 // tso->gran.locked = !spark->global;
2530 // tso->gran.sparkname = spark->name;
2536 /* ---------------------------------------------------------------------------
2539 * scheduleThread puts a thread on the head of the runnable queue.
2540 * This will usually be done immediately after a thread is created.
2541 * The caller of scheduleThread must create the thread using e.g.
2542 * createThread and push an appropriate closure
2543 * on this thread's stack before the scheduler is invoked.
2544 * ------------------------------------------------------------------------ */
2547 scheduleThreadLocked(StgTSO *tso)
2549 // The thread goes at the *end* of the run-queue, to avoid possible
2550 // starvation of any threads already on the queue.
2551 APPEND_TO_RUN_QUEUE(tso);
2556 scheduleThread(StgTSO* tso)
2558 ACQUIRE_LOCK(&sched_mutex);
2559 scheduleThreadLocked(tso);
2560 RELEASE_LOCK(&sched_mutex);
2563 #if defined(RTS_SUPPORTS_THREADS)
2564 static Condition bound_cond_cache;
2565 static int bound_cond_cache_full = 0;
2570 scheduleWaitThread(StgTSO* tso, /*[out]*/HaskellObj* ret,
2571 Capability *initialCapability)
2573 // Precondition: sched_mutex must be held
2576 m = stgMallocBytes(sizeof(StgMainThread), "waitThread");
2581 m->link = main_threads;
2583 if (main_threads != NULL) {
2584 main_threads->prev = m;
2588 #if defined(RTS_SUPPORTS_THREADS)
2589 // Allocating a new condition for each thread is expensive, so we
2590 // cache one. This is a pretty feeble hack, but it helps speed up
2591 // consecutive call-ins quite a bit.
2592 if (bound_cond_cache_full) {
2593 m->bound_thread_cond = bound_cond_cache;
2594 bound_cond_cache_full = 0;
2596 initCondition(&m->bound_thread_cond);
2600 /* Put the thread on the main-threads list prior to scheduling the TSO.
2601 Failure to do so introduces a race condition in the MT case (as
2602 identified by Wolfgang Thaller), whereby the new task/OS thread
2603 created by scheduleThread_() would complete prior to the thread
2604 that spawned it managed to put 'itself' on the main-threads list.
2605 The upshot of it all being that the worker thread wouldn't get to
2606 signal the completion of the its work item for the main thread to
2607 see (==> it got stuck waiting.) -- sof 6/02.
2609 IF_DEBUG(scheduler, sched_belch("waiting for thread (%d)", tso->id));
2611 APPEND_TO_RUN_QUEUE(tso);
2612 // NB. Don't call threadRunnable() here, because the thread is
2613 // bound and only runnable by *this* OS thread, so waking up other
2614 // workers will just slow things down.
2616 return waitThread_(m, initialCapability);
2619 /* ---------------------------------------------------------------------------
2622 * Initialise the scheduler. This resets all the queues - if the
2623 * queues contained any threads, they'll be garbage collected at the
2626 * ------------------------------------------------------------------------ */
2634 for (i=0; i<=MAX_PROC; i++) {
2635 run_queue_hds[i] = END_TSO_QUEUE;
2636 run_queue_tls[i] = END_TSO_QUEUE;
2637 blocked_queue_hds[i] = END_TSO_QUEUE;
2638 blocked_queue_tls[i] = END_TSO_QUEUE;
2639 ccalling_threadss[i] = END_TSO_QUEUE;
2640 blackhole_queue[i] = END_TSO_QUEUE;
2641 sleeping_queue = END_TSO_QUEUE;
2644 run_queue_hd = END_TSO_QUEUE;
2645 run_queue_tl = END_TSO_QUEUE;
2646 blocked_queue_hd = END_TSO_QUEUE;
2647 blocked_queue_tl = END_TSO_QUEUE;
2648 blackhole_queue = END_TSO_QUEUE;
2649 sleeping_queue = END_TSO_QUEUE;
2652 suspended_ccalling_threads = END_TSO_QUEUE;
2654 main_threads = NULL;
2655 all_threads = END_TSO_QUEUE;
2660 RtsFlags.ConcFlags.ctxtSwitchTicks =
2661 RtsFlags.ConcFlags.ctxtSwitchTime / TICK_MILLISECS;
2663 #if defined(RTS_SUPPORTS_THREADS)
2664 /* Initialise the mutex and condition variables used by
2666 initMutex(&sched_mutex);
2667 initMutex(&term_mutex);
2670 ACQUIRE_LOCK(&sched_mutex);
2672 /* A capability holds the state a native thread needs in
2673 * order to execute STG code. At least one capability is
2674 * floating around (only SMP builds have more than one).
2678 #if defined(RTS_SUPPORTS_THREADS)
2683 /* eagerly start some extra workers */
2684 startingWorkerThread = RtsFlags.ParFlags.nNodes;
2685 startTasks(RtsFlags.ParFlags.nNodes, taskStart);
2688 #if /* defined(SMP) ||*/ defined(PARALLEL_HASKELL)
2692 RELEASE_LOCK(&sched_mutex);
2696 exitScheduler( void )
2698 interrupted = rtsTrue;
2699 shutting_down_scheduler = rtsTrue;
2700 #if defined(RTS_SUPPORTS_THREADS)
2701 if (threadIsTask(osThreadId())) { taskStop(); }
2706 /* ----------------------------------------------------------------------------
2707 Managing the per-task allocation areas.
2709 Each capability comes with an allocation area. These are
2710 fixed-length block lists into which allocation can be done.
2712 ToDo: no support for two-space collection at the moment???
2713 ------------------------------------------------------------------------- */
2715 static SchedulerStatus
2716 waitThread_(StgMainThread* m, Capability *initialCapability)
2718 SchedulerStatus stat;
2720 // Precondition: sched_mutex must be held.
2721 IF_DEBUG(scheduler, sched_belch("new main thread (%d)", m->tso->id));
2724 /* GranSim specific init */
2725 CurrentTSO = m->tso; // the TSO to run
2726 procStatus[MainProc] = Busy; // status of main PE
2727 CurrentProc = MainProc; // PE to run it on
2728 schedule(m,initialCapability);
2730 schedule(m,initialCapability);
2731 ASSERT(m->stat != NoStatus);
2736 #if defined(RTS_SUPPORTS_THREADS)
2737 // Free the condition variable, returning it to the cache if possible.
2738 if (!bound_cond_cache_full) {
2739 bound_cond_cache = m->bound_thread_cond;
2740 bound_cond_cache_full = 1;
2742 closeCondition(&m->bound_thread_cond);
2746 IF_DEBUG(scheduler, sched_belch("main thread (%d) finished", m->tso->id));
2749 // Postcondition: sched_mutex still held
2753 /* ---------------------------------------------------------------------------
2754 Where are the roots that we know about?
2756 - all the threads on the runnable queue
2757 - all the threads on the blocked queue
2758 - all the threads on the sleeping queue
2759 - all the thread currently executing a _ccall_GC
2760 - all the "main threads"
2762 ------------------------------------------------------------------------ */
2764 /* This has to be protected either by the scheduler monitor, or by the
2765 garbage collection monitor (probably the latter).
2770 GetRoots( evac_fn evac )
2775 for (i=0; i<=RtsFlags.GranFlags.proc; i++) {
2776 if ((run_queue_hds[i] != END_TSO_QUEUE) && ((run_queue_hds[i] != NULL)))
2777 evac((StgClosure **)&run_queue_hds[i]);
2778 if ((run_queue_tls[i] != END_TSO_QUEUE) && ((run_queue_tls[i] != NULL)))
2779 evac((StgClosure **)&run_queue_tls[i]);
2781 if ((blocked_queue_hds[i] != END_TSO_QUEUE) && ((blocked_queue_hds[i] != NULL)))
2782 evac((StgClosure **)&blocked_queue_hds[i]);
2783 if ((blocked_queue_tls[i] != END_TSO_QUEUE) && ((blocked_queue_tls[i] != NULL)))
2784 evac((StgClosure **)&blocked_queue_tls[i]);
2785 if ((ccalling_threadss[i] != END_TSO_QUEUE) && ((ccalling_threadss[i] != NULL)))
2786 evac((StgClosure **)&ccalling_threads[i]);
2793 if (run_queue_hd != END_TSO_QUEUE) {
2794 ASSERT(run_queue_tl != END_TSO_QUEUE);
2795 evac((StgClosure **)&run_queue_hd);
2796 evac((StgClosure **)&run_queue_tl);
2799 if (blocked_queue_hd != END_TSO_QUEUE) {
2800 ASSERT(blocked_queue_tl != END_TSO_QUEUE);
2801 evac((StgClosure **)&blocked_queue_hd);
2802 evac((StgClosure **)&blocked_queue_tl);
2805 if (sleeping_queue != END_TSO_QUEUE) {
2806 evac((StgClosure **)&sleeping_queue);
2810 if (blackhole_queue != END_TSO_QUEUE) {
2811 evac((StgClosure **)&blackhole_queue);
2814 if (suspended_ccalling_threads != END_TSO_QUEUE) {
2815 evac((StgClosure **)&suspended_ccalling_threads);
2818 #if defined(PARALLEL_HASKELL) || defined(GRAN)
2819 markSparkQueue(evac);
2822 #if defined(RTS_USER_SIGNALS)
2823 // mark the signal handlers (signals should be already blocked)
2824 markSignalHandlers(evac);
2828 /* -----------------------------------------------------------------------------
2831 This is the interface to the garbage collector from Haskell land.
2832 We provide this so that external C code can allocate and garbage
2833 collect when called from Haskell via _ccall_GC.
2835 It might be useful to provide an interface whereby the programmer
2836 can specify more roots (ToDo).
2838 This needs to be protected by the GC condition variable above. KH.
2839 -------------------------------------------------------------------------- */
2841 static void (*extra_roots)(evac_fn);
2846 /* Obligated to hold this lock upon entry */
2847 ACQUIRE_LOCK(&sched_mutex);
2848 GarbageCollect(GetRoots,rtsFalse);
2849 RELEASE_LOCK(&sched_mutex);
2853 performMajorGC(void)
2855 ACQUIRE_LOCK(&sched_mutex);
2856 GarbageCollect(GetRoots,rtsTrue);
2857 RELEASE_LOCK(&sched_mutex);
2861 AllRoots(evac_fn evac)
2863 GetRoots(evac); // the scheduler's roots
2864 extra_roots(evac); // the user's roots
2868 performGCWithRoots(void (*get_roots)(evac_fn))
2870 ACQUIRE_LOCK(&sched_mutex);
2871 extra_roots = get_roots;
2872 GarbageCollect(AllRoots,rtsFalse);
2873 RELEASE_LOCK(&sched_mutex);
2876 /* -----------------------------------------------------------------------------
2879 If the thread has reached its maximum stack size, then raise the
2880 StackOverflow exception in the offending thread. Otherwise
2881 relocate the TSO into a larger chunk of memory and adjust its stack
2883 -------------------------------------------------------------------------- */
2886 threadStackOverflow(StgTSO *tso)
2888 nat new_stack_size, stack_words;
2893 IF_DEBUG(sanity,checkTSO(tso));
2894 if (tso->stack_size >= tso->max_stack_size) {
2897 debugBelch("@@ threadStackOverflow of TSO %ld (%p): stack too large (now %ld; max is %ld)\n",
2898 (long)tso->id, tso, (long)tso->stack_size, (long)tso->max_stack_size);
2899 /* If we're debugging, just print out the top of the stack */
2900 printStackChunk(tso->sp, stg_min(tso->stack+tso->stack_size,
2903 /* Send this thread the StackOverflow exception */
2904 raiseAsync(tso, (StgClosure *)stackOverflow_closure);
2908 /* Try to double the current stack size. If that takes us over the
2909 * maximum stack size for this thread, then use the maximum instead.
2910 * Finally round up so the TSO ends up as a whole number of blocks.
2912 new_stack_size = stg_min(tso->stack_size * 2, tso->max_stack_size);
2913 new_tso_size = (lnat)BLOCK_ROUND_UP(new_stack_size * sizeof(W_) +
2914 TSO_STRUCT_SIZE)/sizeof(W_);
2915 new_tso_size = round_to_mblocks(new_tso_size); /* Be MBLOCK-friendly */
2916 new_stack_size = new_tso_size - TSO_STRUCT_SIZEW;
2918 IF_DEBUG(scheduler, debugBelch("== sched: increasing stack size from %d words to %d.\n", tso->stack_size, new_stack_size));
2920 dest = (StgTSO *)allocate(new_tso_size);
2921 TICK_ALLOC_TSO(new_stack_size,0);
2923 /* copy the TSO block and the old stack into the new area */
2924 memcpy(dest,tso,TSO_STRUCT_SIZE);
2925 stack_words = tso->stack + tso->stack_size - tso->sp;
2926 new_sp = (P_)dest + new_tso_size - stack_words;
2927 memcpy(new_sp, tso->sp, stack_words * sizeof(W_));
2929 /* relocate the stack pointers... */
2931 dest->stack_size = new_stack_size;
2933 /* Mark the old TSO as relocated. We have to check for relocated
2934 * TSOs in the garbage collector and any primops that deal with TSOs.
2936 * It's important to set the sp value to just beyond the end
2937 * of the stack, so we don't attempt to scavenge any part of the
2940 tso->what_next = ThreadRelocated;
2942 tso->sp = (P_)&(tso->stack[tso->stack_size]);
2943 tso->why_blocked = NotBlocked;
2945 IF_PAR_DEBUG(verbose,
2946 debugBelch("@@ threadStackOverflow of TSO %d (now at %p): stack size increased to %ld\n",
2947 tso->id, tso, tso->stack_size);
2948 /* If we're debugging, just print out the top of the stack */
2949 printStackChunk(tso->sp, stg_min(tso->stack+tso->stack_size,
2952 IF_DEBUG(sanity,checkTSO(tso));
2954 IF_DEBUG(scheduler,printTSO(dest));
2960 /* ---------------------------------------------------------------------------
2961 Wake up a queue that was blocked on some resource.
2962 ------------------------------------------------------------------------ */
2966 unblockCount ( StgBlockingQueueElement *bqe, StgClosure *node )
2969 #elif defined(PARALLEL_HASKELL)
2971 unblockCount ( StgBlockingQueueElement *bqe, StgClosure *node )
2973 /* write RESUME events to log file and
2974 update blocked and fetch time (depending on type of the orig closure) */
2975 if (RtsFlags.ParFlags.ParStats.Full) {
2976 DumpRawGranEvent(CURRENT_PROC, CURRENT_PROC,
2977 GR_RESUMEQ, ((StgTSO *)bqe), ((StgTSO *)bqe)->block_info.closure,
2978 0, 0 /* spark_queue_len(ADVISORY_POOL) */);
2979 if (EMPTY_RUN_QUEUE())
2980 emitSchedule = rtsTrue;
2982 switch (get_itbl(node)->type) {
2984 ((StgTSO *)bqe)->par.fetchtime += CURRENT_TIME-((StgTSO *)bqe)->par.blockedat;
2989 ((StgTSO *)bqe)->par.blocktime += CURRENT_TIME-((StgTSO *)bqe)->par.blockedat;
2996 barf("{unblockOneLocked}Daq Qagh: unexpected closure in blocking queue");
3003 StgBlockingQueueElement *
3004 unblockOneLocked(StgBlockingQueueElement *bqe, StgClosure *node)
3007 PEs node_loc, tso_loc;
3009 node_loc = where_is(node); // should be lifted out of loop
3010 tso = (StgTSO *)bqe; // wastes an assignment to get the type right
3011 tso_loc = where_is((StgClosure *)tso);
3012 if (IS_LOCAL_TO(PROCS(node),tso_loc)) { // TSO is local
3013 /* !fake_fetch => TSO is on CurrentProc is same as IS_LOCAL_TO */
3014 ASSERT(CurrentProc!=node_loc || tso_loc==CurrentProc);
3015 CurrentTime[CurrentProc] += RtsFlags.GranFlags.Costs.lunblocktime;
3016 // insertThread(tso, node_loc);
3017 new_event(tso_loc, tso_loc, CurrentTime[CurrentProc],
3019 tso, node, (rtsSpark*)NULL);
3020 tso->link = END_TSO_QUEUE; // overwrite link just to be sure
3023 } else { // TSO is remote (actually should be FMBQ)
3024 CurrentTime[CurrentProc] += RtsFlags.GranFlags.Costs.mpacktime +
3025 RtsFlags.GranFlags.Costs.gunblocktime +
3026 RtsFlags.GranFlags.Costs.latency;
3027 new_event(tso_loc, CurrentProc, CurrentTime[CurrentProc],
3029 tso, node, (rtsSpark*)NULL);
3030 tso->link = END_TSO_QUEUE; // overwrite link just to be sure
3033 /* the thread-queue-overhead is accounted for in either Resume or UnblockThread */
3035 debugBelch(" %s TSO %d (%p) [PE %d] (block_info.closure=%p) (next=%p) ,",
3036 (node_loc==tso_loc ? "Local" : "Global"),
3037 tso->id, tso, CurrentProc, tso->block_info.closure, tso->link));
3038 tso->block_info.closure = NULL;
3039 IF_DEBUG(scheduler,debugBelch("-- Waking up thread %ld (%p)\n",
3042 #elif defined(PARALLEL_HASKELL)
3043 StgBlockingQueueElement *
3044 unblockOneLocked(StgBlockingQueueElement *bqe, StgClosure *node)
3046 StgBlockingQueueElement *next;
3048 switch (get_itbl(bqe)->type) {
3050 ASSERT(((StgTSO *)bqe)->why_blocked != NotBlocked);
3051 /* if it's a TSO just push it onto the run_queue */
3053 ((StgTSO *)bqe)->link = END_TSO_QUEUE; // debugging?
3054 APPEND_TO_RUN_QUEUE((StgTSO *)bqe);
3056 unblockCount(bqe, node);
3057 /* reset blocking status after dumping event */
3058 ((StgTSO *)bqe)->why_blocked = NotBlocked;
3062 /* if it's a BLOCKED_FETCH put it on the PendingFetches list */
3064 bqe->link = (StgBlockingQueueElement *)PendingFetches;
3065 PendingFetches = (StgBlockedFetch *)bqe;
3069 /* can ignore this case in a non-debugging setup;
3070 see comments on RBHSave closures above */
3072 /* check that the closure is an RBHSave closure */
3073 ASSERT(get_itbl((StgClosure *)bqe) == &stg_RBH_Save_0_info ||
3074 get_itbl((StgClosure *)bqe) == &stg_RBH_Save_1_info ||
3075 get_itbl((StgClosure *)bqe) == &stg_RBH_Save_2_info);
3079 barf("{unblockOneLocked}Daq Qagh: Unexpected IP (%#lx; %s) in blocking queue at %#lx\n",
3080 get_itbl((StgClosure *)bqe), info_type((StgClosure *)bqe),
3084 IF_PAR_DEBUG(bq, debugBelch(", %p (%s)\n", bqe, info_type((StgClosure*)bqe)));
3088 #else /* !GRAN && !PARALLEL_HASKELL */
3090 unblockOneLocked(StgTSO *tso)
3094 ASSERT(get_itbl(tso)->type == TSO);
3095 ASSERT(tso->why_blocked != NotBlocked);
3096 tso->why_blocked = NotBlocked;
3098 tso->link = END_TSO_QUEUE;
3099 APPEND_TO_RUN_QUEUE(tso);
3101 IF_DEBUG(scheduler,sched_belch("waking up thread %ld", (long)tso->id));
3106 #if defined(GRAN) || defined(PARALLEL_HASKELL)
3107 INLINE_ME StgBlockingQueueElement *
3108 unblockOne(StgBlockingQueueElement *bqe, StgClosure *node)
3110 ACQUIRE_LOCK(&sched_mutex);
3111 bqe = unblockOneLocked(bqe, node);
3112 RELEASE_LOCK(&sched_mutex);
3117 unblockOne(StgTSO *tso)
3119 ACQUIRE_LOCK(&sched_mutex);
3120 tso = unblockOneLocked(tso);
3121 RELEASE_LOCK(&sched_mutex);
3128 awakenBlockedQueue(StgBlockingQueueElement *q, StgClosure *node)
3130 StgBlockingQueueElement *bqe;
3135 debugBelch("##-_ AwBQ for node %p on PE %d @ %ld by TSO %d (%p): \n", \
3136 node, CurrentProc, CurrentTime[CurrentProc],
3137 CurrentTSO->id, CurrentTSO));
3139 node_loc = where_is(node);
3141 ASSERT(q == END_BQ_QUEUE ||
3142 get_itbl(q)->type == TSO || // q is either a TSO or an RBHSave
3143 get_itbl(q)->type == CONSTR); // closure (type constructor)
3144 ASSERT(is_unique(node));
3146 /* FAKE FETCH: magically copy the node to the tso's proc;
3147 no Fetch necessary because in reality the node should not have been
3148 moved to the other PE in the first place
3150 if (CurrentProc!=node_loc) {
3152 debugBelch("## node %p is on PE %d but CurrentProc is %d (TSO %d); assuming fake fetch and adjusting bitmask (old: %#x)\n",
3153 node, node_loc, CurrentProc, CurrentTSO->id,
3154 // CurrentTSO, where_is(CurrentTSO),
3155 node->header.gran.procs));
3156 node->header.gran.procs = (node->header.gran.procs) | PE_NUMBER(CurrentProc);
3158 debugBelch("## new bitmask of node %p is %#x\n",
3159 node, node->header.gran.procs));
3160 if (RtsFlags.GranFlags.GranSimStats.Global) {
3161 globalGranStats.tot_fake_fetches++;
3166 // ToDo: check: ASSERT(CurrentProc==node_loc);
3167 while (get_itbl(bqe)->type==TSO) { // q != END_TSO_QUEUE) {
3170 bqe points to the current element in the queue
3171 next points to the next element in the queue
3173 //tso = (StgTSO *)bqe; // wastes an assignment to get the type right
3174 //tso_loc = where_is(tso);
3176 bqe = unblockOneLocked(bqe, node);
3179 /* if this is the BQ of an RBH, we have to put back the info ripped out of
3180 the closure to make room for the anchor of the BQ */
3181 if (bqe!=END_BQ_QUEUE) {
3182 ASSERT(get_itbl(node)->type == RBH && get_itbl(bqe)->type == CONSTR);
3184 ASSERT((info_ptr==&RBH_Save_0_info) ||
3185 (info_ptr==&RBH_Save_1_info) ||
3186 (info_ptr==&RBH_Save_2_info));
3188 /* cf. convertToRBH in RBH.c for writing the RBHSave closure */
3189 ((StgRBH *)node)->blocking_queue = (StgBlockingQueueElement *)((StgRBHSave *)bqe)->payload[0];
3190 ((StgRBH *)node)->mut_link = (StgMutClosure *)((StgRBHSave *)bqe)->payload[1];
3193 debugBelch("## Filled in RBH_Save for %p (%s) at end of AwBQ\n",
3194 node, info_type(node)));
3197 /* statistics gathering */
3198 if (RtsFlags.GranFlags.GranSimStats.Global) {
3199 // globalGranStats.tot_bq_processing_time += bq_processing_time;
3200 globalGranStats.tot_bq_len += len; // total length of all bqs awakened
3201 // globalGranStats.tot_bq_len_local += len_local; // same for local TSOs only
3202 globalGranStats.tot_awbq++; // total no. of bqs awakened
3205 debugBelch("## BQ Stats of %p: [%d entries] %s\n",
3206 node, len, (bqe!=END_BQ_QUEUE) ? "RBH" : ""));
3208 #elif defined(PARALLEL_HASKELL)
3210 awakenBlockedQueue(StgBlockingQueueElement *q, StgClosure *node)
3212 StgBlockingQueueElement *bqe;
3214 ACQUIRE_LOCK(&sched_mutex);
3216 IF_PAR_DEBUG(verbose,
3217 debugBelch("##-_ AwBQ for node %p on [%x]: \n",
3221 if(get_itbl(q)->type == CONSTR || q==END_BQ_QUEUE) {
3222 IF_PAR_DEBUG(verbose, debugBelch("## ... nothing to unblock so lets just return. RFP (BUG?)\n"));
3227 ASSERT(q == END_BQ_QUEUE ||
3228 get_itbl(q)->type == TSO ||
3229 get_itbl(q)->type == BLOCKED_FETCH ||
3230 get_itbl(q)->type == CONSTR);
3233 while (get_itbl(bqe)->type==TSO ||
3234 get_itbl(bqe)->type==BLOCKED_FETCH) {
3235 bqe = unblockOneLocked(bqe, node);
3237 RELEASE_LOCK(&sched_mutex);
3240 #else /* !GRAN && !PARALLEL_HASKELL */
3243 awakenBlockedQueueNoLock(StgTSO *tso)
3245 if (tso == NULL) return; // hack; see bug #1235728, and comments in
3247 while (tso != END_TSO_QUEUE) {
3248 tso = unblockOneLocked(tso);
3253 awakenBlockedQueue(StgTSO *tso)
3255 if (tso == NULL) return; // hack; see bug #1235728, and comments in
3257 ACQUIRE_LOCK(&sched_mutex);
3258 while (tso != END_TSO_QUEUE) {
3259 tso = unblockOneLocked(tso);
3261 RELEASE_LOCK(&sched_mutex);
3265 /* ---------------------------------------------------------------------------
3267 - usually called inside a signal handler so it mustn't do anything fancy.
3268 ------------------------------------------------------------------------ */
3271 interruptStgRts(void)
3276 /* ToDo: if invoked from a signal handler, this threadRunnable
3277 * only works if there's another thread (not this one) waiting to
3282 /* -----------------------------------------------------------------------------
3285 This is for use when we raise an exception in another thread, which
3287 This has nothing to do with the UnblockThread event in GranSim. -- HWL
3288 -------------------------------------------------------------------------- */
3290 #if defined(GRAN) || defined(PARALLEL_HASKELL)
3292 NB: only the type of the blocking queue is different in GranSim and GUM
3293 the operations on the queue-elements are the same
3294 long live polymorphism!
3296 Locks: sched_mutex is held upon entry and exit.
3300 unblockThread(StgTSO *tso)
3302 StgBlockingQueueElement *t, **last;
3304 switch (tso->why_blocked) {
3307 return; /* not blocked */
3310 // Be careful: nothing to do here! We tell the scheduler that the thread
3311 // is runnable and we leave it to the stack-walking code to abort the
3312 // transaction while unwinding the stack. We should perhaps have a debugging
3313 // test to make sure that this really happens and that the 'zombie' transaction
3314 // does not get committed.
3318 ASSERT(get_itbl(tso->block_info.closure)->type == MVAR);
3320 StgBlockingQueueElement *last_tso = END_BQ_QUEUE;
3321 StgMVar *mvar = (StgMVar *)(tso->block_info.closure);
3323 last = (StgBlockingQueueElement **)&mvar->head;
3324 for (t = (StgBlockingQueueElement *)mvar->head;
3326 last = &t->link, last_tso = t, t = t->link) {
3327 if (t == (StgBlockingQueueElement *)tso) {
3328 *last = (StgBlockingQueueElement *)tso->link;
3329 if (mvar->tail == tso) {
3330 mvar->tail = (StgTSO *)last_tso;
3335 barf("unblockThread (MVAR): TSO not found");
3338 case BlockedOnBlackHole:
3339 ASSERT(get_itbl(tso->block_info.closure)->type == BLACKHOLE_BQ);
3341 StgBlockingQueue *bq = (StgBlockingQueue *)(tso->block_info.closure);
3343 last = &bq->blocking_queue;
3344 for (t = bq->blocking_queue;
3346 last = &t->link, t = t->link) {
3347 if (t == (StgBlockingQueueElement *)tso) {
3348 *last = (StgBlockingQueueElement *)tso->link;
3352 barf("unblockThread (BLACKHOLE): TSO not found");
3355 case BlockedOnException:
3357 StgTSO *target = tso->block_info.tso;
3359 ASSERT(get_itbl(target)->type == TSO);
3361 if (target->what_next == ThreadRelocated) {
3362 target = target->link;
3363 ASSERT(get_itbl(target)->type == TSO);
3366 ASSERT(target->blocked_exceptions != NULL);
3368 last = (StgBlockingQueueElement **)&target->blocked_exceptions;
3369 for (t = (StgBlockingQueueElement *)target->blocked_exceptions;
3371 last = &t->link, t = t->link) {
3372 ASSERT(get_itbl(t)->type == TSO);
3373 if (t == (StgBlockingQueueElement *)tso) {
3374 *last = (StgBlockingQueueElement *)tso->link;
3378 barf("unblockThread (Exception): TSO not found");
3382 case BlockedOnWrite:
3383 #if defined(mingw32_HOST_OS)
3384 case BlockedOnDoProc:
3387 /* take TSO off blocked_queue */
3388 StgBlockingQueueElement *prev = NULL;
3389 for (t = (StgBlockingQueueElement *)blocked_queue_hd; t != END_BQ_QUEUE;
3390 prev = t, t = t->link) {
3391 if (t == (StgBlockingQueueElement *)tso) {
3393 blocked_queue_hd = (StgTSO *)t->link;
3394 if ((StgBlockingQueueElement *)blocked_queue_tl == t) {
3395 blocked_queue_tl = END_TSO_QUEUE;
3398 prev->link = t->link;
3399 if ((StgBlockingQueueElement *)blocked_queue_tl == t) {
3400 blocked_queue_tl = (StgTSO *)prev;
3403 #if defined(mingw32_HOST_OS)
3404 /* (Cooperatively) signal that the worker thread should abort
3407 abandonWorkRequest(tso->block_info.async_result->reqID);
3412 barf("unblockThread (I/O): TSO not found");
3415 case BlockedOnDelay:
3417 /* take TSO off sleeping_queue */
3418 StgBlockingQueueElement *prev = NULL;
3419 for (t = (StgBlockingQueueElement *)sleeping_queue; t != END_BQ_QUEUE;
3420 prev = t, t = t->link) {
3421 if (t == (StgBlockingQueueElement *)tso) {
3423 sleeping_queue = (StgTSO *)t->link;
3425 prev->link = t->link;
3430 barf("unblockThread (delay): TSO not found");
3434 barf("unblockThread");
3438 tso->link = END_TSO_QUEUE;
3439 tso->why_blocked = NotBlocked;
3440 tso->block_info.closure = NULL;
3441 PUSH_ON_RUN_QUEUE(tso);
3445 unblockThread(StgTSO *tso)
3449 /* To avoid locking unnecessarily. */
3450 if (tso->why_blocked == NotBlocked) {
3454 switch (tso->why_blocked) {
3457 // Be careful: nothing to do here! We tell the scheduler that the thread
3458 // is runnable and we leave it to the stack-walking code to abort the
3459 // transaction while unwinding the stack. We should perhaps have a debugging
3460 // test to make sure that this really happens and that the 'zombie' transaction
3461 // does not get committed.
3465 ASSERT(get_itbl(tso->block_info.closure)->type == MVAR);
3467 StgTSO *last_tso = END_TSO_QUEUE;
3468 StgMVar *mvar = (StgMVar *)(tso->block_info.closure);
3471 for (t = mvar->head; t != END_TSO_QUEUE;
3472 last = &t->link, last_tso = t, t = t->link) {
3475 if (mvar->tail == tso) {
3476 mvar->tail = last_tso;
3481 barf("unblockThread (MVAR): TSO not found");
3484 case BlockedOnBlackHole:
3486 last = &blackhole_queue;
3487 for (t = blackhole_queue; t != END_TSO_QUEUE;
3488 last = &t->link, t = t->link) {
3494 barf("unblockThread (BLACKHOLE): TSO not found");
3497 case BlockedOnException:
3499 StgTSO *target = tso->block_info.tso;
3501 ASSERT(get_itbl(target)->type == TSO);
3503 while (target->what_next == ThreadRelocated) {
3504 target = target->link;
3505 ASSERT(get_itbl(target)->type == TSO);
3508 ASSERT(target->blocked_exceptions != NULL);
3510 last = &target->blocked_exceptions;
3511 for (t = target->blocked_exceptions; t != END_TSO_QUEUE;
3512 last = &t->link, t = t->link) {
3513 ASSERT(get_itbl(t)->type == TSO);
3519 barf("unblockThread (Exception): TSO not found");
3523 case BlockedOnWrite:
3524 #if defined(mingw32_HOST_OS)
3525 case BlockedOnDoProc:
3528 StgTSO *prev = NULL;
3529 for (t = blocked_queue_hd; t != END_TSO_QUEUE;
3530 prev = t, t = t->link) {
3533 blocked_queue_hd = t->link;
3534 if (blocked_queue_tl == t) {
3535 blocked_queue_tl = END_TSO_QUEUE;
3538 prev->link = t->link;
3539 if (blocked_queue_tl == t) {
3540 blocked_queue_tl = prev;
3543 #if defined(mingw32_HOST_OS)
3544 /* (Cooperatively) signal that the worker thread should abort
3547 abandonWorkRequest(tso->block_info.async_result->reqID);
3552 barf("unblockThread (I/O): TSO not found");
3555 case BlockedOnDelay:
3557 StgTSO *prev = NULL;
3558 for (t = sleeping_queue; t != END_TSO_QUEUE;
3559 prev = t, t = t->link) {
3562 sleeping_queue = t->link;
3564 prev->link = t->link;
3569 barf("unblockThread (delay): TSO not found");
3573 barf("unblockThread");
3577 tso->link = END_TSO_QUEUE;
3578 tso->why_blocked = NotBlocked;
3579 tso->block_info.closure = NULL;
3580 APPEND_TO_RUN_QUEUE(tso);
3584 /* -----------------------------------------------------------------------------
3587 * Check the blackhole_queue for threads that can be woken up. We do
3588 * this periodically: before every GC, and whenever the run queue is
3591 * An elegant solution might be to just wake up all the blocked
3592 * threads with awakenBlockedQueue occasionally: they'll go back to
3593 * sleep again if the object is still a BLACKHOLE. Unfortunately this
3594 * doesn't give us a way to tell whether we've actually managed to
3595 * wake up any threads, so we would be busy-waiting.
3597 * -------------------------------------------------------------------------- */
3600 checkBlackHoles( void )
3603 rtsBool any_woke_up = rtsFalse;
3606 IF_DEBUG(scheduler, sched_belch("checking threads blocked on black holes"));
3608 // ASSUMES: sched_mutex
3609 prev = &blackhole_queue;
3610 t = blackhole_queue;
3611 while (t != END_TSO_QUEUE) {
3612 ASSERT(t->why_blocked == BlockedOnBlackHole);
3613 type = get_itbl(t->block_info.closure)->type;
3614 if (type != BLACKHOLE && type != CAF_BLACKHOLE) {
3615 IF_DEBUG(sanity,checkTSO(t));
3616 t = unblockOneLocked(t);
3618 any_woke_up = rtsTrue;
3628 /* -----------------------------------------------------------------------------
3631 * The following function implements the magic for raising an
3632 * asynchronous exception in an existing thread.
3634 * We first remove the thread from any queue on which it might be
3635 * blocked. The possible blockages are MVARs and BLACKHOLE_BQs.
3637 * We strip the stack down to the innermost CATCH_FRAME, building
3638 * thunks in the heap for all the active computations, so they can
3639 * be restarted if necessary. When we reach a CATCH_FRAME, we build
3640 * an application of the handler to the exception, and push it on
3641 * the top of the stack.
3643 * How exactly do we save all the active computations? We create an
3644 * AP_STACK for every UpdateFrame on the stack. Entering one of these
3645 * AP_STACKs pushes everything from the corresponding update frame
3646 * upwards onto the stack. (Actually, it pushes everything up to the
3647 * next update frame plus a pointer to the next AP_STACK object.
3648 * Entering the next AP_STACK object pushes more onto the stack until we
3649 * reach the last AP_STACK object - at which point the stack should look
3650 * exactly as it did when we killed the TSO and we can continue
3651 * execution by entering the closure on top of the stack.
3653 * We can also kill a thread entirely - this happens if either (a) the
3654 * exception passed to raiseAsync is NULL, or (b) there's no
3655 * CATCH_FRAME on the stack. In either case, we strip the entire
3656 * stack and replace the thread with a zombie.
3658 * Locks: sched_mutex held upon entry nor exit.
3660 * -------------------------------------------------------------------------- */
3663 deleteThread(StgTSO *tso)
3665 if (tso->why_blocked != BlockedOnCCall &&
3666 tso->why_blocked != BlockedOnCCall_NoUnblockExc) {
3667 raiseAsync(tso,NULL);
3671 #ifdef FORKPROCESS_PRIMOP_SUPPORTED
3673 deleteThreadImmediately(StgTSO *tso)
3674 { // for forkProcess only:
3675 // delete thread without giving it a chance to catch the KillThread exception
3677 if (tso->what_next == ThreadComplete || tso->what_next == ThreadKilled) {
3681 if (tso->why_blocked != BlockedOnCCall &&
3682 tso->why_blocked != BlockedOnCCall_NoUnblockExc) {
3686 tso->what_next = ThreadKilled;
3691 raiseAsyncWithLock(StgTSO *tso, StgClosure *exception)
3693 /* When raising async exs from contexts where sched_mutex isn't held;
3694 use raiseAsyncWithLock(). */
3695 ACQUIRE_LOCK(&sched_mutex);
3696 raiseAsync(tso,exception);
3697 RELEASE_LOCK(&sched_mutex);
3701 raiseAsync(StgTSO *tso, StgClosure *exception)
3703 raiseAsync_(tso, exception, rtsFalse);
3707 raiseAsync_(StgTSO *tso, StgClosure *exception, rtsBool stop_at_atomically)
3709 StgRetInfoTable *info;
3712 // Thread already dead?
3713 if (tso->what_next == ThreadComplete || tso->what_next == ThreadKilled) {
3718 sched_belch("raising exception in thread %ld.", (long)tso->id));
3720 // Remove it from any blocking queues
3725 // The stack freezing code assumes there's a closure pointer on
3726 // the top of the stack, so we have to arrange that this is the case...
3728 if (sp[0] == (W_)&stg_enter_info) {
3732 sp[0] = (W_)&stg_dummy_ret_closure;
3738 // 1. Let the top of the stack be the "current closure"
3740 // 2. Walk up the stack until we find either an UPDATE_FRAME or a
3743 // 3. If it's an UPDATE_FRAME, then make an AP_STACK containing the
3744 // current closure applied to the chunk of stack up to (but not
3745 // including) the update frame. This closure becomes the "current
3746 // closure". Go back to step 2.
3748 // 4. If it's a CATCH_FRAME, then leave the exception handler on
3749 // top of the stack applied to the exception.
3751 // 5. If it's a STOP_FRAME, then kill the thread.
3753 // NB: if we pass an ATOMICALLY_FRAME then abort the associated
3760 info = get_ret_itbl((StgClosure *)frame);
3762 while (info->i.type != UPDATE_FRAME
3763 && (info->i.type != CATCH_FRAME || exception == NULL)
3764 && info->i.type != STOP_FRAME
3765 && (info->i.type != ATOMICALLY_FRAME || stop_at_atomically == rtsFalse))
3767 if (info->i.type == CATCH_RETRY_FRAME || info->i.type == ATOMICALLY_FRAME) {
3768 // IF we find an ATOMICALLY_FRAME then we abort the
3769 // current transaction and propagate the exception. In
3770 // this case (unlike ordinary exceptions) we do not care
3771 // whether the transaction is valid or not because its
3772 // possible validity cannot have caused the exception
3773 // and will not be visible after the abort.
3775 debugBelch("Found atomically block delivering async exception\n"));
3776 stmAbortTransaction(tso -> trec);
3777 tso -> trec = stmGetEnclosingTRec(tso -> trec);
3779 frame += stack_frame_sizeW((StgClosure *)frame);
3780 info = get_ret_itbl((StgClosure *)frame);
3783 switch (info->i.type) {
3785 case ATOMICALLY_FRAME:
3786 ASSERT(stop_at_atomically);
3787 ASSERT(stmGetEnclosingTRec(tso->trec) == NO_TREC);
3788 stmCondemnTransaction(tso -> trec);
3792 // R1 is not a register: the return convention for IO in
3793 // this case puts the return value on the stack, so we
3794 // need to set up the stack to return to the atomically
3795 // frame properly...
3796 tso->sp = frame - 2;
3797 tso->sp[1] = (StgWord) &stg_NO_FINALIZER_closure; // why not?
3798 tso->sp[0] = (StgWord) &stg_ut_1_0_unreg_info;
3800 tso->what_next = ThreadRunGHC;
3804 // If we find a CATCH_FRAME, and we've got an exception to raise,
3805 // then build the THUNK raise(exception), and leave it on
3806 // top of the CATCH_FRAME ready to enter.
3810 StgCatchFrame *cf = (StgCatchFrame *)frame;
3814 // we've got an exception to raise, so let's pass it to the
3815 // handler in this frame.
3817 raise = (StgThunk *)allocate(sizeofW(StgThunk)+MIN_UPD_SIZE);
3818 TICK_ALLOC_SE_THK(1,0);
3819 SET_HDR(raise,&stg_raise_info,cf->header.prof.ccs);
3820 raise->payload[0] = exception;
3822 // throw away the stack from Sp up to the CATCH_FRAME.
3826 /* Ensure that async excpetions are blocked now, so we don't get
3827 * a surprise exception before we get around to executing the
3830 if (tso->blocked_exceptions == NULL) {
3831 tso->blocked_exceptions = END_TSO_QUEUE;
3834 /* Put the newly-built THUNK on top of the stack, ready to execute
3835 * when the thread restarts.
3838 sp[-1] = (W_)&stg_enter_info;
3840 tso->what_next = ThreadRunGHC;
3841 IF_DEBUG(sanity, checkTSO(tso));
3850 // First build an AP_STACK consisting of the stack chunk above the
3851 // current update frame, with the top word on the stack as the
3854 words = frame - sp - 1;
3855 ap = (StgAP_STACK *)allocate(AP_STACK_sizeW(words));
3858 ap->fun = (StgClosure *)sp[0];
3860 for(i=0; i < (nat)words; ++i) {
3861 ap->payload[i] = (StgClosure *)*sp++;
3864 SET_HDR(ap,&stg_AP_STACK_info,
3865 ((StgClosure *)frame)->header.prof.ccs /* ToDo */);
3866 TICK_ALLOC_UP_THK(words+1,0);
3869 debugBelch("sched: Updating ");
3870 printPtr((P_)((StgUpdateFrame *)frame)->updatee);
3871 debugBelch(" with ");
3872 printObj((StgClosure *)ap);
3875 // Replace the updatee with an indirection - happily
3876 // this will also wake up any threads currently
3877 // waiting on the result.
3879 // Warning: if we're in a loop, more than one update frame on
3880 // the stack may point to the same object. Be careful not to
3881 // overwrite an IND_OLDGEN in this case, because we'll screw
3882 // up the mutable lists. To be on the safe side, don't
3883 // overwrite any kind of indirection at all. See also
3884 // threadSqueezeStack in GC.c, where we have to make a similar
3887 if (!closure_IND(((StgUpdateFrame *)frame)->updatee)) {
3888 // revert the black hole
3889 UPD_IND_NOLOCK(((StgUpdateFrame *)frame)->updatee,
3892 sp += sizeofW(StgUpdateFrame) - 1;
3893 sp[0] = (W_)ap; // push onto stack
3898 // We've stripped the entire stack, the thread is now dead.
3899 sp += sizeofW(StgStopFrame);
3900 tso->what_next = ThreadKilled;
3911 /* -----------------------------------------------------------------------------
3912 raiseExceptionHelper
3914 This function is called by the raise# primitve, just so that we can
3915 move some of the tricky bits of raising an exception from C-- into
3916 C. Who knows, it might be a useful re-useable thing here too.
3917 -------------------------------------------------------------------------- */
3920 raiseExceptionHelper (StgTSO *tso, StgClosure *exception)
3922 StgThunk *raise_closure = NULL;
3924 StgRetInfoTable *info;
3926 // This closure represents the expression 'raise# E' where E
3927 // is the exception raise. It is used to overwrite all the
3928 // thunks which are currently under evaluataion.
3932 // LDV profiling: stg_raise_info has THUNK as its closure
3933 // type. Since a THUNK takes at least MIN_UPD_SIZE words in its
3934 // payload, MIN_UPD_SIZE is more approprate than 1. It seems that
3935 // 1 does not cause any problem unless profiling is performed.
3936 // However, when LDV profiling goes on, we need to linearly scan
3937 // small object pool, where raise_closure is stored, so we should
3938 // use MIN_UPD_SIZE.
3940 // raise_closure = (StgClosure *)RET_STGCALL1(P_,allocate,
3941 // sizeofW(StgClosure)+1);
3945 // Walk up the stack, looking for the catch frame. On the way,
3946 // we update any closures pointed to from update frames with the
3947 // raise closure that we just built.
3951 info = get_ret_itbl((StgClosure *)p);
3952 next = p + stack_frame_sizeW((StgClosure *)p);
3953 switch (info->i.type) {
3956 // Only create raise_closure if we need to.
3957 if (raise_closure == NULL) {
3959 (StgThunk *)allocate(sizeofW(StgThunk)+MIN_UPD_SIZE);
3960 SET_HDR(raise_closure, &stg_raise_info, CCCS);
3961 raise_closure->payload[0] = exception;
3963 UPD_IND(((StgUpdateFrame *)p)->updatee,(StgClosure *)raise_closure);
3967 case ATOMICALLY_FRAME:
3968 IF_DEBUG(stm, debugBelch("Found ATOMICALLY_FRAME at %p\n", p));
3970 return ATOMICALLY_FRAME;
3976 case CATCH_STM_FRAME:
3977 IF_DEBUG(stm, debugBelch("Found CATCH_STM_FRAME at %p\n", p));
3979 return CATCH_STM_FRAME;
3985 case CATCH_RETRY_FRAME:
3994 /* -----------------------------------------------------------------------------
3995 findRetryFrameHelper
3997 This function is called by the retry# primitive. It traverses the stack
3998 leaving tso->sp referring to the frame which should handle the retry.
4000 This should either be a CATCH_RETRY_FRAME (if the retry# is within an orElse#)
4001 or should be a ATOMICALLY_FRAME (if the retry# reaches the top level).
4003 We skip CATCH_STM_FRAMEs because retries are not considered to be exceptions,
4004 despite the similar implementation.
4006 We should not expect to see CATCH_FRAME or STOP_FRAME because those should
4007 not be created within memory transactions.
4008 -------------------------------------------------------------------------- */
4011 findRetryFrameHelper (StgTSO *tso)
4014 StgRetInfoTable *info;
4018 info = get_ret_itbl((StgClosure *)p);
4019 next = p + stack_frame_sizeW((StgClosure *)p);
4020 switch (info->i.type) {
4022 case ATOMICALLY_FRAME:
4023 IF_DEBUG(stm, debugBelch("Found ATOMICALLY_FRAME at %p during retrry\n", p));
4025 return ATOMICALLY_FRAME;
4027 case CATCH_RETRY_FRAME:
4028 IF_DEBUG(stm, debugBelch("Found CATCH_RETRY_FRAME at %p during retrry\n", p));
4030 return CATCH_RETRY_FRAME;
4032 case CATCH_STM_FRAME:
4034 ASSERT(info->i.type != CATCH_FRAME);
4035 ASSERT(info->i.type != STOP_FRAME);
4042 /* -----------------------------------------------------------------------------
4043 resurrectThreads is called after garbage collection on the list of
4044 threads found to be garbage. Each of these threads will be woken
4045 up and sent a signal: BlockedOnDeadMVar if the thread was blocked
4046 on an MVar, or NonTermination if the thread was blocked on a Black
4049 Locks: sched_mutex isn't held upon entry nor exit.
4050 -------------------------------------------------------------------------- */
4053 resurrectThreads( StgTSO *threads )
4057 for (tso = threads; tso != END_TSO_QUEUE; tso = next) {
4058 next = tso->global_link;
4059 tso->global_link = all_threads;
4061 IF_DEBUG(scheduler, sched_belch("resurrecting thread %d", tso->id));
4063 switch (tso->why_blocked) {
4065 case BlockedOnException:
4066 /* Called by GC - sched_mutex lock is currently held. */
4067 raiseAsync(tso,(StgClosure *)BlockedOnDeadMVar_closure);
4069 case BlockedOnBlackHole:
4070 raiseAsync(tso,(StgClosure *)NonTermination_closure);
4073 raiseAsync(tso,(StgClosure *)BlockedIndefinitely_closure);
4076 /* This might happen if the thread was blocked on a black hole
4077 * belonging to a thread that we've just woken up (raiseAsync
4078 * can wake up threads, remember...).
4082 barf("resurrectThreads: thread blocked in a strange way");
4087 /* ----------------------------------------------------------------------------
4088 * Debugging: why is a thread blocked
4089 * [Also provides useful information when debugging threaded programs
4090 * at the Haskell source code level, so enable outside of DEBUG. --sof 7/02]
4091 ------------------------------------------------------------------------- */
4094 printThreadBlockage(StgTSO *tso)
4096 switch (tso->why_blocked) {
4098 debugBelch("is blocked on read from fd %d", (int)(tso->block_info.fd));
4100 case BlockedOnWrite:
4101 debugBelch("is blocked on write to fd %d", (int)(tso->block_info.fd));
4103 #if defined(mingw32_HOST_OS)
4104 case BlockedOnDoProc:
4105 debugBelch("is blocked on proc (request: %ld)", tso->block_info.async_result->reqID);
4108 case BlockedOnDelay:
4109 debugBelch("is blocked until %ld", (long)(tso->block_info.target));
4112 debugBelch("is blocked on an MVar @ %p", tso->block_info.closure);
4114 case BlockedOnException:
4115 debugBelch("is blocked on delivering an exception to thread %d",
4116 tso->block_info.tso->id);
4118 case BlockedOnBlackHole:
4119 debugBelch("is blocked on a black hole");
4122 debugBelch("is not blocked");
4124 #if defined(PARALLEL_HASKELL)
4126 debugBelch("is blocked on global address; local FM_BQ is %p (%s)",
4127 tso->block_info.closure, info_type(tso->block_info.closure));
4129 case BlockedOnGA_NoSend:
4130 debugBelch("is blocked on global address (no send); local FM_BQ is %p (%s)",
4131 tso->block_info.closure, info_type(tso->block_info.closure));
4134 case BlockedOnCCall:
4135 debugBelch("is blocked on an external call");
4137 case BlockedOnCCall_NoUnblockExc:
4138 debugBelch("is blocked on an external call (exceptions were already blocked)");
4141 debugBelch("is blocked on an STM operation");
4144 barf("printThreadBlockage: strange tso->why_blocked: %d for TSO %d (%d)",
4145 tso->why_blocked, tso->id, tso);
4150 printThreadStatus(StgTSO *tso)
4152 switch (tso->what_next) {
4154 debugBelch("has been killed");
4156 case ThreadComplete:
4157 debugBelch("has completed");
4160 printThreadBlockage(tso);
4165 printAllThreads(void)
4170 char time_string[TIME_STR_LEN], node_str[NODE_STR_LEN];
4171 ullong_format_string(TIME_ON_PROC(CurrentProc),
4172 time_string, rtsFalse/*no commas!*/);
4174 debugBelch("all threads at [%s]:\n", time_string);
4175 # elif defined(PARALLEL_HASKELL)
4176 char time_string[TIME_STR_LEN], node_str[NODE_STR_LEN];
4177 ullong_format_string(CURRENT_TIME,
4178 time_string, rtsFalse/*no commas!*/);
4180 debugBelch("all threads at [%s]:\n", time_string);
4182 debugBelch("all threads:\n");
4185 for (t = all_threads; t != END_TSO_QUEUE; ) {
4186 debugBelch("\tthread %4d @ %p ", t->id, (void *)t);
4189 void *label = lookupThreadLabel(t->id);
4190 if (label) debugBelch("[\"%s\"] ",(char *)label);
4193 if (t->what_next == ThreadRelocated) {
4194 debugBelch("has been relocated...\n");
4197 printThreadStatus(t);
4208 printThreadQueue(StgTSO *t)
4211 for (; t != END_TSO_QUEUE; t = t->link) {
4212 debugBelch("\tthread %d @ %p ", t->id, (void *)t);
4213 if (t->what_next == ThreadRelocated) {
4214 debugBelch("has been relocated...\n");
4216 printThreadStatus(t);
4221 debugBelch("%d threads on queue\n", i);
4225 Print a whole blocking queue attached to node (debugging only).
4227 # if defined(PARALLEL_HASKELL)
4229 print_bq (StgClosure *node)
4231 StgBlockingQueueElement *bqe;
4235 debugBelch("## BQ of closure %p (%s): ",
4236 node, info_type(node));
4238 /* should cover all closures that may have a blocking queue */
4239 ASSERT(get_itbl(node)->type == BLACKHOLE_BQ ||
4240 get_itbl(node)->type == FETCH_ME_BQ ||
4241 get_itbl(node)->type == RBH ||
4242 get_itbl(node)->type == MVAR);
4244 ASSERT(node!=(StgClosure*)NULL); // sanity check
4246 print_bqe(((StgBlockingQueue*)node)->blocking_queue);
4250 Print a whole blocking queue starting with the element bqe.
4253 print_bqe (StgBlockingQueueElement *bqe)
4258 NB: In a parallel setup a BQ of an RBH must end with an RBH_Save closure;
4260 for (end = (bqe==END_BQ_QUEUE);
4261 !end; // iterate until bqe points to a CONSTR
4262 end = (get_itbl(bqe)->type == CONSTR) || (bqe->link==END_BQ_QUEUE),
4263 bqe = end ? END_BQ_QUEUE : bqe->link) {
4264 ASSERT(bqe != END_BQ_QUEUE); // sanity check
4265 ASSERT(bqe != (StgBlockingQueueElement *)NULL); // sanity check
4266 /* types of closures that may appear in a blocking queue */
4267 ASSERT(get_itbl(bqe)->type == TSO ||
4268 get_itbl(bqe)->type == BLOCKED_FETCH ||
4269 get_itbl(bqe)->type == CONSTR);
4270 /* only BQs of an RBH end with an RBH_Save closure */
4271 //ASSERT(get_itbl(bqe)->type != CONSTR || get_itbl(node)->type == RBH);
4273 switch (get_itbl(bqe)->type) {
4275 debugBelch(" TSO %u (%x),",
4276 ((StgTSO *)bqe)->id, ((StgTSO *)bqe));
4279 debugBelch(" BF (node=%p, ga=((%x, %d, %x)),",
4280 ((StgBlockedFetch *)bqe)->node,
4281 ((StgBlockedFetch *)bqe)->ga.payload.gc.gtid,
4282 ((StgBlockedFetch *)bqe)->ga.payload.gc.slot,
4283 ((StgBlockedFetch *)bqe)->ga.weight);
4286 debugBelch(" %s (IP %p),",
4287 (get_itbl(bqe) == &stg_RBH_Save_0_info ? "RBH_Save_0" :
4288 get_itbl(bqe) == &stg_RBH_Save_1_info ? "RBH_Save_1" :
4289 get_itbl(bqe) == &stg_RBH_Save_2_info ? "RBH_Save_2" :
4290 "RBH_Save_?"), get_itbl(bqe));
4293 barf("Unexpected closure type %s in blocking queue", // of %p (%s)",
4294 info_type((StgClosure *)bqe)); // , node, info_type(node));
4300 # elif defined(GRAN)
4302 print_bq (StgClosure *node)
4304 StgBlockingQueueElement *bqe;
4305 PEs node_loc, tso_loc;
4308 /* should cover all closures that may have a blocking queue */
4309 ASSERT(get_itbl(node)->type == BLACKHOLE_BQ ||
4310 get_itbl(node)->type == FETCH_ME_BQ ||
4311 get_itbl(node)->type == RBH);
4313 ASSERT(node!=(StgClosure*)NULL); // sanity check
4314 node_loc = where_is(node);
4316 debugBelch("## BQ of closure %p (%s) on [PE %d]: ",
4317 node, info_type(node), node_loc);
4320 NB: In a parallel setup a BQ of an RBH must end with an RBH_Save closure;
4322 for (bqe = ((StgBlockingQueue*)node)->blocking_queue, end = (bqe==END_BQ_QUEUE);
4323 !end; // iterate until bqe points to a CONSTR
4324 end = (get_itbl(bqe)->type == CONSTR) || (bqe->link==END_BQ_QUEUE), bqe = end ? END_BQ_QUEUE : bqe->link) {
4325 ASSERT(bqe != END_BQ_QUEUE); // sanity check
4326 ASSERT(bqe != (StgBlockingQueueElement *)NULL); // sanity check
4327 /* types of closures that may appear in a blocking queue */
4328 ASSERT(get_itbl(bqe)->type == TSO ||
4329 get_itbl(bqe)->type == CONSTR);
4330 /* only BQs of an RBH end with an RBH_Save closure */
4331 ASSERT(get_itbl(bqe)->type != CONSTR || get_itbl(node)->type == RBH);
4333 tso_loc = where_is((StgClosure *)bqe);
4334 switch (get_itbl(bqe)->type) {
4336 debugBelch(" TSO %d (%p) on [PE %d],",
4337 ((StgTSO *)bqe)->id, (StgTSO *)bqe, tso_loc);
4340 debugBelch(" %s (IP %p),",
4341 (get_itbl(bqe) == &stg_RBH_Save_0_info ? "RBH_Save_0" :
4342 get_itbl(bqe) == &stg_RBH_Save_1_info ? "RBH_Save_1" :
4343 get_itbl(bqe) == &stg_RBH_Save_2_info ? "RBH_Save_2" :
4344 "RBH_Save_?"), get_itbl(bqe));
4347 barf("Unexpected closure type %s in blocking queue of %p (%s)",
4348 info_type((StgClosure *)bqe), node, info_type(node));
4356 #if defined(PARALLEL_HASKELL)
4363 for (i=0, tso=run_queue_hd;
4364 tso != END_TSO_QUEUE;
4373 sched_belch(char *s, ...)
4377 #ifdef RTS_SUPPORTS_THREADS
4378 debugBelch("sched (task %p): ", osThreadId());
4379 #elif defined(PARALLEL_HASKELL)
4382 debugBelch("sched: ");