1 /* ---------------------------------------------------------------------------
3 * (c) The GHC Team, 1998-2005
5 * The scheduler and thread-related functionality
7 * --------------------------------------------------------------------------*/
9 #include "PosixSource.h"
14 #include "BlockAlloc.h"
15 #include "OSThreads.h"
20 #include "StgMiscClosures.h"
21 #include "Interpreter.h"
22 #include "Exception.h"
24 #include "RtsSignals.h"
30 #include "ThreadLabels.h"
31 #include "LdvProfile.h"
34 #include "Proftimer.h"
37 #if defined(GRAN) || defined(PARALLEL_HASKELL)
38 # include "GranSimRts.h"
40 # include "ParallelRts.h"
41 # include "Parallel.h"
42 # include "ParallelDebug.h"
47 #include "Capability.h"
49 #include "AwaitEvent.h"
50 #if defined(mingw32_HOST_OS)
51 #include "win32/IOManager.h"
54 #ifdef HAVE_SYS_TYPES_H
55 #include <sys/types.h>
69 // Turn off inlining when debugging - it obfuscates things
72 # define STATIC_INLINE static
75 /* -----------------------------------------------------------------------------
77 * -------------------------------------------------------------------------- */
81 StgTSO* ActiveTSO = NULL; /* for assigning system costs; GranSim-Light only */
82 /* rtsTime TimeOfNextEvent, EndOfTimeSlice; now in GranSim.c */
85 In GranSim we have a runnable and a blocked queue for each processor.
86 In order to minimise code changes new arrays run_queue_hds/tls
87 are created. run_queue_hd is then a short cut (macro) for
88 run_queue_hds[CurrentProc] (see GranSim.h).
91 StgTSO *run_queue_hds[MAX_PROC], *run_queue_tls[MAX_PROC];
92 StgTSO *blocked_queue_hds[MAX_PROC], *blocked_queue_tls[MAX_PROC];
93 StgTSO *ccalling_threadss[MAX_PROC];
94 /* We use the same global list of threads (all_threads) in GranSim as in
95 the std RTS (i.e. we are cheating). However, we don't use this list in
96 the GranSim specific code at the moment (so we are only potentially
101 #if !defined(THREADED_RTS)
102 // Blocked/sleeping thrads
103 StgTSO *blocked_queue_hd = NULL;
104 StgTSO *blocked_queue_tl = NULL;
105 StgTSO *sleeping_queue = NULL; // perhaps replace with a hash table?
108 /* Threads blocked on blackholes.
109 * LOCK: sched_mutex+capability, or all capabilities
111 StgTSO *blackhole_queue = NULL;
114 /* The blackhole_queue should be checked for threads to wake up. See
115 * Schedule.h for more thorough comment.
116 * LOCK: none (doesn't matter if we miss an update)
118 rtsBool blackholes_need_checking = rtsFalse;
120 /* Linked list of all threads.
121 * Used for detecting garbage collected threads.
122 * LOCK: sched_mutex+capability, or all capabilities
124 StgTSO *all_threads = NULL;
126 /* flag set by signal handler to precipitate a context switch
127 * LOCK: none (just an advisory flag)
129 int context_switch = 0;
131 /* flag that tracks whether we have done any execution in this time slice.
132 * LOCK: currently none, perhaps we should lock (but needs to be
133 * updated in the fast path of the scheduler).
135 nat recent_activity = ACTIVITY_YES;
137 /* if this flag is set as well, give up execution
138 * LOCK: none (changes once, from false->true)
140 rtsBool interrupted = rtsFalse;
142 /* Next thread ID to allocate.
145 static StgThreadID next_thread_id = 1;
147 /* The smallest stack size that makes any sense is:
148 * RESERVED_STACK_WORDS (so we can get back from the stack overflow)
149 * + sizeofW(StgStopFrame) (the stg_stop_thread_info frame)
150 * + 1 (the closure to enter)
152 * + 1 (spare slot req'd by stg_ap_v_ret)
154 * A thread with this stack will bomb immediately with a stack
155 * overflow, which will increase its stack size.
157 #define MIN_STACK_WORDS (RESERVED_STACK_WORDS + sizeofW(StgStopFrame) + 3)
163 /* This is used in `TSO.h' and gcc 2.96 insists that this variable actually
164 * exists - earlier gccs apparently didn't.
170 * Set to TRUE when entering a shutdown state (via shutdownHaskellAndExit()) --
171 * in an MT setting, needed to signal that a worker thread shouldn't hang around
172 * in the scheduler when it is out of work.
174 rtsBool shutting_down_scheduler = rtsFalse;
177 * This mutex protects most of the global scheduler data in
178 * the THREADED_RTS runtime.
180 #if defined(THREADED_RTS)
184 #if defined(PARALLEL_HASKELL)
186 rtsTime TimeOfLastYield;
187 rtsBool emitSchedule = rtsTrue;
190 /* -----------------------------------------------------------------------------
191 * static function prototypes
192 * -------------------------------------------------------------------------- */
194 static Capability *schedule (Capability *initialCapability, Task *task);
197 // These function all encapsulate parts of the scheduler loop, and are
198 // abstracted only to make the structure and control flow of the
199 // scheduler clearer.
201 static void schedulePreLoop (void);
202 #if defined(THREADED_RTS)
203 static void schedulePushWork(Capability *cap, Task *task);
205 static void scheduleStartSignalHandlers (Capability *cap);
206 static void scheduleCheckBlockedThreads (Capability *cap);
207 static void scheduleCheckBlackHoles (Capability *cap);
208 static void scheduleDetectDeadlock (Capability *cap, Task *task);
210 static StgTSO *scheduleProcessEvent(rtsEvent *event);
212 #if defined(PARALLEL_HASKELL)
213 static StgTSO *scheduleSendPendingMessages(void);
214 static void scheduleActivateSpark(void);
215 static rtsBool scheduleGetRemoteWork(rtsBool *receivedFinish);
217 #if defined(PAR) || defined(GRAN)
218 static void scheduleGranParReport(void);
220 static void schedulePostRunThread(void);
221 static rtsBool scheduleHandleHeapOverflow( Capability *cap, StgTSO *t );
222 static void scheduleHandleStackOverflow( Capability *cap, Task *task,
224 static rtsBool scheduleHandleYield( Capability *cap, StgTSO *t,
225 nat prev_what_next );
226 static void scheduleHandleThreadBlocked( StgTSO *t );
227 static rtsBool scheduleHandleThreadFinished( Capability *cap, Task *task,
229 static rtsBool scheduleDoHeapProfile(rtsBool ready_to_gc);
230 static void scheduleDoGC(Capability *cap, Task *task, rtsBool force_major,
231 void (*get_roots)(evac_fn));
233 static void unblockThread(Capability *cap, StgTSO *tso);
234 static rtsBool checkBlackHoles(Capability *cap);
235 static void AllRoots(evac_fn evac);
237 static StgTSO *threadStackOverflow(Capability *cap, StgTSO *tso);
239 static void raiseAsync_(Capability *cap, StgTSO *tso, StgClosure *exception,
240 rtsBool stop_at_atomically, StgPtr stop_here);
242 static void deleteThread (Capability *cap, StgTSO *tso);
243 static void deleteRunQueue (Capability *cap);
246 static void printThreadBlockage(StgTSO *tso);
247 static void printThreadStatus(StgTSO *tso);
248 void printThreadQueue(StgTSO *tso);
251 #if defined(PARALLEL_HASKELL)
252 StgTSO * createSparkThread(rtsSpark spark);
253 StgTSO * activateSpark (rtsSpark spark);
257 static char *whatNext_strs[] = {
267 /* -----------------------------------------------------------------------------
268 * Putting a thread on the run queue: different scheduling policies
269 * -------------------------------------------------------------------------- */
272 addToRunQueue( Capability *cap, StgTSO *t )
274 #if defined(PARALLEL_HASKELL)
275 if (RtsFlags.ParFlags.doFairScheduling) {
276 // this does round-robin scheduling; good for concurrency
277 appendToRunQueue(cap,t);
279 // this does unfair scheduling; good for parallelism
280 pushOnRunQueue(cap,t);
283 // this does round-robin scheduling; good for concurrency
284 appendToRunQueue(cap,t);
288 /* ---------------------------------------------------------------------------
289 Main scheduling loop.
291 We use round-robin scheduling, each thread returning to the
292 scheduler loop when one of these conditions is detected:
295 * timer expires (thread yields)
301 In a GranSim setup this loop iterates over the global event queue.
302 This revolves around the global event queue, which determines what
303 to do next. Therefore, it's more complicated than either the
304 concurrent or the parallel (GUM) setup.
307 GUM iterates over incoming messages.
308 It starts with nothing to do (thus CurrentTSO == END_TSO_QUEUE),
309 and sends out a fish whenever it has nothing to do; in-between
310 doing the actual reductions (shared code below) it processes the
311 incoming messages and deals with delayed operations
312 (see PendingFetches).
313 This is not the ugliest code you could imagine, but it's bloody close.
315 ------------------------------------------------------------------------ */
318 schedule (Capability *initialCapability, Task *task)
322 StgThreadReturnCode ret;
325 #elif defined(PARALLEL_HASKELL)
328 rtsBool receivedFinish = rtsFalse;
330 nat tp_size, sp_size; // stats only
335 #if defined(THREADED_RTS)
336 rtsBool first = rtsTrue;
339 cap = initialCapability;
341 // Pre-condition: this task owns initialCapability.
342 // The sched_mutex is *NOT* held
343 // NB. on return, we still hold a capability.
346 sched_belch("### NEW SCHEDULER LOOP (task: %p, cap: %p)",
347 task, initialCapability);
352 // -----------------------------------------------------------
353 // Scheduler loop starts here:
355 #if defined(PARALLEL_HASKELL)
356 #define TERMINATION_CONDITION (!receivedFinish)
358 #define TERMINATION_CONDITION ((event = get_next_event()) != (rtsEvent*)NULL)
360 #define TERMINATION_CONDITION rtsTrue
363 while (TERMINATION_CONDITION) {
366 /* Choose the processor with the next event */
367 CurrentProc = event->proc;
368 CurrentTSO = event->tso;
371 #if defined(THREADED_RTS)
373 // don't yield the first time, we want a chance to run this
374 // thread for a bit, even if there are others banging at the
377 ASSERT_FULL_CAPABILITY_INVARIANTS(cap,task);
379 // Yield the capability to higher-priority tasks if necessary.
380 yieldCapability(&cap, task);
384 #if defined(THREADED_RTS)
385 schedulePushWork(cap,task);
388 // Check whether we have re-entered the RTS from Haskell without
389 // going via suspendThread()/resumeThread (i.e. a 'safe' foreign
391 if (cap->in_haskell) {
392 errorBelch("schedule: re-entered unsafely.\n"
393 " Perhaps a 'foreign import unsafe' should be 'safe'?");
394 stg_exit(EXIT_FAILURE);
398 // Test for interruption. If interrupted==rtsTrue, then either
399 // we received a keyboard interrupt (^C), or the scheduler is
400 // trying to shut down all the tasks (shutting_down_scheduler) in
405 #if defined(THREADED_RTS)
406 discardSparksCap(cap);
408 if (shutting_down_scheduler) {
409 IF_DEBUG(scheduler, sched_belch("shutting down"));
410 // If we are a worker, just exit. If we're a bound thread
411 // then we will exit below when we've removed our TSO from
413 if (task->tso == NULL && emptyRunQueue(cap)) {
417 IF_DEBUG(scheduler, sched_belch("interrupted"));
421 #if defined(THREADED_RTS)
422 // If the run queue is empty, take a spark and turn it into a thread.
424 if (emptyRunQueue(cap)) {
426 spark = findSpark(cap);
429 sched_belch("turning spark of closure %p into a thread",
430 (StgClosure *)spark));
431 createSparkThread(cap,spark);
435 #endif // THREADED_RTS
437 scheduleStartSignalHandlers(cap);
439 // Only check the black holes here if we've nothing else to do.
440 // During normal execution, the black hole list only gets checked
441 // at GC time, to avoid repeatedly traversing this possibly long
442 // list each time around the scheduler.
443 if (emptyRunQueue(cap)) { scheduleCheckBlackHoles(cap); }
445 scheduleCheckBlockedThreads(cap);
447 scheduleDetectDeadlock(cap,task);
448 #if defined(THREADED_RTS)
449 cap = task->cap; // reload cap, it might have changed
452 // Normally, the only way we can get here with no threads to
453 // run is if a keyboard interrupt received during
454 // scheduleCheckBlockedThreads() or scheduleDetectDeadlock().
455 // Additionally, it is not fatal for the
456 // threaded RTS to reach here with no threads to run.
458 // win32: might be here due to awaitEvent() being abandoned
459 // as a result of a console event having been delivered.
460 if ( emptyRunQueue(cap) ) {
461 #if !defined(THREADED_RTS) && !defined(mingw32_HOST_OS)
464 continue; // nothing to do
467 #if defined(PARALLEL_HASKELL)
468 scheduleSendPendingMessages();
469 if (emptyRunQueue(cap) && scheduleActivateSpark())
473 ASSERT(next_fish_to_send_at==0); // i.e. no delayed fishes left!
476 /* If we still have no work we need to send a FISH to get a spark
478 if (emptyRunQueue(cap)) {
479 if (!scheduleGetRemoteWork(&receivedFinish)) continue;
480 ASSERT(rtsFalse); // should not happen at the moment
482 // from here: non-empty run queue.
483 // TODO: merge above case with this, only one call processMessages() !
484 if (PacketsWaiting()) { /* process incoming messages, if
485 any pending... only in else
486 because getRemoteWork waits for
488 receivedFinish = processMessages();
493 scheduleProcessEvent(event);
497 // Get a thread to run
499 t = popRunQueue(cap);
501 #if defined(GRAN) || defined(PAR)
502 scheduleGranParReport(); // some kind of debuging output
504 // Sanity check the thread we're about to run. This can be
505 // expensive if there is lots of thread switching going on...
506 IF_DEBUG(sanity,checkTSO(t));
509 #if defined(THREADED_RTS)
510 // Check whether we can run this thread in the current task.
511 // If not, we have to pass our capability to the right task.
513 Task *bound = t->bound;
518 sched_belch("### Running thread %d in bound thread",
520 // yes, the Haskell thread is bound to the current native thread
523 sched_belch("### thread %d bound to another OS thread",
525 // no, bound to a different Haskell thread: pass to that thread
526 pushOnRunQueue(cap,t);
530 // The thread we want to run is unbound.
533 sched_belch("### this OS thread cannot run thread %d", t->id));
534 // no, the current native thread is bound to a different
535 // Haskell thread, so pass it to any worker thread
536 pushOnRunQueue(cap,t);
543 cap->r.rCurrentTSO = t;
545 /* context switches are initiated by the timer signal, unless
546 * the user specified "context switch as often as possible", with
549 if (RtsFlags.ConcFlags.ctxtSwitchTicks == 0
550 && !emptyThreadQueues(cap)) {
556 IF_DEBUG(scheduler, sched_belch("-->> running thread %ld %s ...",
557 (long)t->id, whatNext_strs[t->what_next]));
559 #if defined(PROFILING)
560 startHeapProfTimer();
563 // ----------------------------------------------------------------------
564 // Run the current thread
566 prev_what_next = t->what_next;
568 errno = t->saved_errno;
569 cap->in_haskell = rtsTrue;
573 recent_activity = ACTIVITY_YES;
575 switch (prev_what_next) {
579 /* Thread already finished, return to scheduler. */
580 ret = ThreadFinished;
586 r = StgRun((StgFunPtr) stg_returnToStackTop, &cap->r);
587 cap = regTableToCapability(r);
592 case ThreadInterpret:
593 cap = interpretBCO(cap);
598 barf("schedule: invalid what_next field");
601 cap->in_haskell = rtsFalse;
603 // The TSO might have moved, eg. if it re-entered the RTS and a GC
604 // happened. So find the new location:
605 t = cap->r.rCurrentTSO;
607 // We have run some Haskell code: there might be blackhole-blocked
608 // threads to wake up now.
609 // Lock-free test here should be ok, we're just setting a flag.
610 if ( blackhole_queue != END_TSO_QUEUE ) {
611 blackholes_need_checking = rtsTrue;
614 // And save the current errno in this thread.
615 // XXX: possibly bogus for SMP because this thread might already
616 // be running again, see code below.
617 t->saved_errno = errno;
620 // If ret is ThreadBlocked, and this Task is bound to the TSO that
621 // blocked, we are in limbo - the TSO is now owned by whatever it
622 // is blocked on, and may in fact already have been woken up,
623 // perhaps even on a different Capability. It may be the case
624 // that task->cap != cap. We better yield this Capability
625 // immediately and return to normaility.
626 if (ret == ThreadBlocked) {
628 sched_belch("--<< thread %d (%s) stopped: blocked\n",
629 t->id, whatNext_strs[t->what_next]));
634 ASSERT_FULL_CAPABILITY_INVARIANTS(cap,task);
636 // ----------------------------------------------------------------------
638 // Costs for the scheduler are assigned to CCS_SYSTEM
639 #if defined(PROFILING)
644 #if defined(THREADED_RTS)
645 IF_DEBUG(scheduler,debugBelch("sched (task %p): ", (void *)(unsigned long)(unsigned int)osThreadId()););
646 #elif !defined(GRAN) && !defined(PARALLEL_HASKELL)
647 IF_DEBUG(scheduler,debugBelch("sched: "););
650 schedulePostRunThread();
652 ready_to_gc = rtsFalse;
656 ready_to_gc = scheduleHandleHeapOverflow(cap,t);
660 scheduleHandleStackOverflow(cap,task,t);
664 if (scheduleHandleYield(cap, t, prev_what_next)) {
665 // shortcut for switching between compiler/interpreter:
671 scheduleHandleThreadBlocked(t);
675 if (scheduleHandleThreadFinished(cap, task, t)) return cap;
676 ASSERT_FULL_CAPABILITY_INVARIANTS(cap,task);
680 barf("schedule: invalid thread return code %d", (int)ret);
683 if (scheduleDoHeapProfile(ready_to_gc)) { ready_to_gc = rtsFalse; }
685 scheduleDoGC(cap,task,rtsFalse,GetRoots);
686 #if defined(THREADED_RTS)
687 cap = task->cap; // reload cap, it might have changed
690 } /* end of while() */
692 IF_PAR_DEBUG(verbose,
693 debugBelch("== Leaving schedule() after having received Finish\n"));
696 /* ----------------------------------------------------------------------------
697 * Setting up the scheduler loop
698 * ------------------------------------------------------------------------- */
701 schedulePreLoop(void)
704 /* set up first event to get things going */
705 /* ToDo: assign costs for system setup and init MainTSO ! */
706 new_event(CurrentProc, CurrentProc, CurrentTime[CurrentProc],
708 CurrentTSO, (StgClosure*)NULL, (rtsSpark*)NULL);
711 debugBelch("GRAN: Init CurrentTSO (in schedule) = %p\n",
713 G_TSO(CurrentTSO, 5));
715 if (RtsFlags.GranFlags.Light) {
716 /* Save current time; GranSim Light only */
717 CurrentTSO->gran.clock = CurrentTime[CurrentProc];
722 /* -----------------------------------------------------------------------------
725 * Push work to other Capabilities if we have some.
726 * -------------------------------------------------------------------------- */
728 #if defined(THREADED_RTS)
730 schedulePushWork(Capability *cap USED_IF_THREADS,
731 Task *task USED_IF_THREADS)
733 Capability *free_caps[n_capabilities], *cap0;
736 // Check whether we have more threads on our run queue, or sparks
737 // in our pool, that we could hand to another Capability.
738 if ((emptyRunQueue(cap) || cap->run_queue_hd->link == END_TSO_QUEUE)
739 && sparkPoolSizeCap(cap) < 2) {
743 // First grab as many free Capabilities as we can.
744 for (i=0, n_free_caps=0; i < n_capabilities; i++) {
745 cap0 = &capabilities[i];
746 if (cap != cap0 && tryGrabCapability(cap0,task)) {
747 if (!emptyRunQueue(cap0) || cap->returning_tasks_hd != NULL) {
748 // it already has some work, we just grabbed it at
749 // the wrong moment. Or maybe it's deadlocked!
750 releaseCapability(cap0);
752 free_caps[n_free_caps++] = cap0;
757 // we now have n_free_caps free capabilities stashed in
758 // free_caps[]. Share our run queue equally with them. This is
759 // probably the simplest thing we could do; improvements we might
760 // want to do include:
762 // - giving high priority to moving relatively new threads, on
763 // the gournds that they haven't had time to build up a
764 // working set in the cache on this CPU/Capability.
766 // - giving low priority to moving long-lived threads
768 if (n_free_caps > 0) {
769 StgTSO *prev, *t, *next;
770 rtsBool pushed_to_all;
772 IF_DEBUG(scheduler, sched_belch("excess threads on run queue and %d free capabilities, sharing...", n_free_caps));
775 pushed_to_all = rtsFalse;
777 if (cap->run_queue_hd != END_TSO_QUEUE) {
778 prev = cap->run_queue_hd;
780 prev->link = END_TSO_QUEUE;
781 for (; t != END_TSO_QUEUE; t = next) {
783 t->link = END_TSO_QUEUE;
784 if (t->what_next == ThreadRelocated
785 || t->bound == task) { // don't move my bound thread
788 } else if (i == n_free_caps) {
789 pushed_to_all = rtsTrue;
795 IF_DEBUG(scheduler, sched_belch("pushing thread %d to capability %d", t->id, free_caps[i]->no));
796 appendToRunQueue(free_caps[i],t);
797 if (t->bound) { t->bound->cap = free_caps[i]; }
801 cap->run_queue_tl = prev;
804 // If there are some free capabilities that we didn't push any
805 // threads to, then try to push a spark to each one.
806 if (!pushed_to_all) {
808 // i is the next free capability to push to
809 for (; i < n_free_caps; i++) {
810 if (emptySparkPoolCap(free_caps[i])) {
811 spark = findSpark(cap);
813 IF_DEBUG(scheduler, sched_belch("pushing spark %p to capability %d", spark, free_caps[i]->no));
814 newSpark(&(free_caps[i]->r), spark);
820 // release the capabilities
821 for (i = 0; i < n_free_caps; i++) {
822 task->cap = free_caps[i];
823 releaseCapability(free_caps[i]);
826 task->cap = cap; // reset to point to our Capability.
830 /* ----------------------------------------------------------------------------
831 * Start any pending signal handlers
832 * ------------------------------------------------------------------------- */
834 #if defined(RTS_USER_SIGNALS) && (!defined(THREADED_RTS) || defined(mingw32_HOST_OS))
836 scheduleStartSignalHandlers(Capability *cap)
838 if (signals_pending()) { // safe outside the lock
839 startSignalHandlers(cap);
844 scheduleStartSignalHandlers(Capability *cap STG_UNUSED)
849 /* ----------------------------------------------------------------------------
850 * Check for blocked threads that can be woken up.
851 * ------------------------------------------------------------------------- */
854 scheduleCheckBlockedThreads(Capability *cap USED_IF_NOT_THREADS)
856 #if !defined(THREADED_RTS)
858 // Check whether any waiting threads need to be woken up. If the
859 // run queue is empty, and there are no other tasks running, we
860 // can wait indefinitely for something to happen.
862 if ( !emptyQueue(blocked_queue_hd) || !emptyQueue(sleeping_queue) )
864 awaitEvent( emptyRunQueue(cap) && !blackholes_need_checking );
870 /* ----------------------------------------------------------------------------
871 * Check for threads blocked on BLACKHOLEs that can be woken up
872 * ------------------------------------------------------------------------- */
874 scheduleCheckBlackHoles (Capability *cap)
876 if ( blackholes_need_checking ) // check without the lock first
878 ACQUIRE_LOCK(&sched_mutex);
879 if ( blackholes_need_checking ) {
880 checkBlackHoles(cap);
881 blackholes_need_checking = rtsFalse;
883 RELEASE_LOCK(&sched_mutex);
887 /* ----------------------------------------------------------------------------
888 * Detect deadlock conditions and attempt to resolve them.
889 * ------------------------------------------------------------------------- */
892 scheduleDetectDeadlock (Capability *cap, Task *task)
895 #if defined(PARALLEL_HASKELL)
896 // ToDo: add deadlock detection in GUM (similar to THREADED_RTS) -- HWL
901 * Detect deadlock: when we have no threads to run, there are no
902 * threads blocked, waiting for I/O, or sleeping, and all the
903 * other tasks are waiting for work, we must have a deadlock of
906 if ( emptyThreadQueues(cap) )
908 #if defined(THREADED_RTS)
910 * In the threaded RTS, we only check for deadlock if there
911 * has been no activity in a complete timeslice. This means
912 * we won't eagerly start a full GC just because we don't have
913 * any threads to run currently.
915 if (recent_activity != ACTIVITY_INACTIVE) return;
918 IF_DEBUG(scheduler, sched_belch("deadlocked, forcing major GC..."));
920 // Garbage collection can release some new threads due to
921 // either (a) finalizers or (b) threads resurrected because
922 // they are unreachable and will therefore be sent an
923 // exception. Any threads thus released will be immediately
925 scheduleDoGC( cap, task, rtsTrue/*force major GC*/, GetRoots );
926 #if defined(THREADED_RTS)
927 cap = task->cap; // reload cap, it might have changed
930 recent_activity = ACTIVITY_DONE_GC;
932 if ( !emptyRunQueue(cap) ) return;
934 #if defined(RTS_USER_SIGNALS) && (!defined(THREADED_RTS) || defined(mingw32_HOST_OS))
935 /* If we have user-installed signal handlers, then wait
936 * for signals to arrive rather then bombing out with a
939 if ( anyUserHandlers() ) {
941 sched_belch("still deadlocked, waiting for signals..."));
945 if (signals_pending()) {
946 startSignalHandlers(cap);
949 // either we have threads to run, or we were interrupted:
950 ASSERT(!emptyRunQueue(cap) || interrupted);
954 #if !defined(THREADED_RTS)
955 /* Probably a real deadlock. Send the current main thread the
956 * Deadlock exception.
959 switch (task->tso->why_blocked) {
961 case BlockedOnBlackHole:
962 case BlockedOnException:
964 raiseAsync(cap, task->tso, (StgClosure *)NonTermination_closure);
967 barf("deadlock: main thread blocked in a strange way");
975 /* ----------------------------------------------------------------------------
976 * Process an event (GRAN only)
977 * ------------------------------------------------------------------------- */
981 scheduleProcessEvent(rtsEvent *event)
985 if (RtsFlags.GranFlags.Light)
986 GranSimLight_enter_system(event, &ActiveTSO); // adjust ActiveTSO etc
988 /* adjust time based on time-stamp */
989 if (event->time > CurrentTime[CurrentProc] &&
990 event->evttype != ContinueThread)
991 CurrentTime[CurrentProc] = event->time;
993 /* Deal with the idle PEs (may issue FindWork or MoveSpark events) */
994 if (!RtsFlags.GranFlags.Light)
997 IF_DEBUG(gran, debugBelch("GRAN: switch by event-type\n"));
999 /* main event dispatcher in GranSim */
1000 switch (event->evttype) {
1001 /* Should just be continuing execution */
1002 case ContinueThread:
1003 IF_DEBUG(gran, debugBelch("GRAN: doing ContinueThread\n"));
1004 /* ToDo: check assertion
1005 ASSERT(run_queue_hd != (StgTSO*)NULL &&
1006 run_queue_hd != END_TSO_QUEUE);
1008 /* Ignore ContinueThreads for fetching threads (if synchr comm) */
1009 if (!RtsFlags.GranFlags.DoAsyncFetch &&
1010 procStatus[CurrentProc]==Fetching) {
1011 debugBelch("ghuH: Spurious ContinueThread while Fetching ignored; TSO %d (%p) [PE %d]\n",
1012 CurrentTSO->id, CurrentTSO, CurrentProc);
1015 /* Ignore ContinueThreads for completed threads */
1016 if (CurrentTSO->what_next == ThreadComplete) {
1017 debugBelch("ghuH: found a ContinueThread event for completed thread %d (%p) [PE %d] (ignoring ContinueThread)\n",
1018 CurrentTSO->id, CurrentTSO, CurrentProc);
1021 /* Ignore ContinueThreads for threads that are being migrated */
1022 if (PROCS(CurrentTSO)==Nowhere) {
1023 debugBelch("ghuH: trying to run the migrating TSO %d (%p) [PE %d] (ignoring ContinueThread)\n",
1024 CurrentTSO->id, CurrentTSO, CurrentProc);
1027 /* The thread should be at the beginning of the run queue */
1028 if (CurrentTSO!=run_queue_hds[CurrentProc]) {
1029 debugBelch("ghuH: TSO %d (%p) [PE %d] is not at the start of the run_queue when doing a ContinueThread\n",
1030 CurrentTSO->id, CurrentTSO, CurrentProc);
1031 break; // run the thread anyway
1034 new_event(proc, proc, CurrentTime[proc],
1036 (StgTSO*)NULL, (StgClosure*)NULL, (rtsSpark*)NULL);
1038 */ /* Catches superfluous CONTINUEs -- should be unnecessary */
1039 break; // now actually run the thread; DaH Qu'vam yImuHbej
1042 do_the_fetchnode(event);
1043 goto next_thread; /* handle next event in event queue */
1046 do_the_globalblock(event);
1047 goto next_thread; /* handle next event in event queue */
1050 do_the_fetchreply(event);
1051 goto next_thread; /* handle next event in event queue */
1053 case UnblockThread: /* Move from the blocked queue to the tail of */
1054 do_the_unblock(event);
1055 goto next_thread; /* handle next event in event queue */
1057 case ResumeThread: /* Move from the blocked queue to the tail of */
1058 /* the runnable queue ( i.e. Qu' SImqa'lu') */
1059 event->tso->gran.blocktime +=
1060 CurrentTime[CurrentProc] - event->tso->gran.blockedat;
1061 do_the_startthread(event);
1062 goto next_thread; /* handle next event in event queue */
1065 do_the_startthread(event);
1066 goto next_thread; /* handle next event in event queue */
1069 do_the_movethread(event);
1070 goto next_thread; /* handle next event in event queue */
1073 do_the_movespark(event);
1074 goto next_thread; /* handle next event in event queue */
1077 do_the_findwork(event);
1078 goto next_thread; /* handle next event in event queue */
1081 barf("Illegal event type %u\n", event->evttype);
1084 /* This point was scheduler_loop in the old RTS */
1086 IF_DEBUG(gran, debugBelch("GRAN: after main switch\n"));
1088 TimeOfLastEvent = CurrentTime[CurrentProc];
1089 TimeOfNextEvent = get_time_of_next_event();
1090 IgnoreEvents=(TimeOfNextEvent==0); // HWL HACK
1091 // CurrentTSO = ThreadQueueHd;
1093 IF_DEBUG(gran, debugBelch("GRAN: time of next event is: %ld\n",
1096 if (RtsFlags.GranFlags.Light)
1097 GranSimLight_leave_system(event, &ActiveTSO);
1099 EndOfTimeSlice = CurrentTime[CurrentProc]+RtsFlags.GranFlags.time_slice;
1102 debugBelch("GRAN: end of time-slice is %#lx\n", EndOfTimeSlice));
1104 /* in a GranSim setup the TSO stays on the run queue */
1106 /* Take a thread from the run queue. */
1107 POP_RUN_QUEUE(t); // take_off_run_queue(t);
1110 debugBelch("GRAN: About to run current thread, which is\n");
1113 context_switch = 0; // turned on via GranYield, checking events and time slice
1116 DumpGranEvent(GR_SCHEDULE, t));
1118 procStatus[CurrentProc] = Busy;
1122 /* ----------------------------------------------------------------------------
1123 * Send pending messages (PARALLEL_HASKELL only)
1124 * ------------------------------------------------------------------------- */
1126 #if defined(PARALLEL_HASKELL)
1128 scheduleSendPendingMessages(void)
1134 # if defined(PAR) // global Mem.Mgmt., omit for now
1135 if (PendingFetches != END_BF_QUEUE) {
1140 if (RtsFlags.ParFlags.BufferTime) {
1141 // if we use message buffering, we must send away all message
1142 // packets which have become too old...
1148 /* ----------------------------------------------------------------------------
1149 * Activate spark threads (PARALLEL_HASKELL only)
1150 * ------------------------------------------------------------------------- */
1152 #if defined(PARALLEL_HASKELL)
1154 scheduleActivateSpark(void)
1157 ASSERT(emptyRunQueue());
1158 /* We get here if the run queue is empty and want some work.
1159 We try to turn a spark into a thread, and add it to the run queue,
1160 from where it will be picked up in the next iteration of the scheduler
1164 /* :-[ no local threads => look out for local sparks */
1165 /* the spark pool for the current PE */
1166 pool = &(cap.r.rSparks); // JB: cap = (old) MainCap
1167 if (advisory_thread_count < RtsFlags.ParFlags.maxThreads &&
1168 pool->hd < pool->tl) {
1170 * ToDo: add GC code check that we really have enough heap afterwards!!
1172 * If we're here (no runnable threads) and we have pending
1173 * sparks, we must have a space problem. Get enough space
1174 * to turn one of those pending sparks into a
1178 spark = findSpark(rtsFalse); /* get a spark */
1179 if (spark != (rtsSpark) NULL) {
1180 tso = createThreadFromSpark(spark); /* turn the spark into a thread */
1181 IF_PAR_DEBUG(fish, // schedule,
1182 debugBelch("==== schedule: Created TSO %d (%p); %d threads active\n",
1183 tso->id, tso, advisory_thread_count));
1185 if (tso==END_TSO_QUEUE) { /* failed to activate spark->back to loop */
1186 IF_PAR_DEBUG(fish, // schedule,
1187 debugBelch("==^^ failed to create thread from spark @ %lx\n",
1189 return rtsFalse; /* failed to generate a thread */
1190 } /* otherwise fall through & pick-up new tso */
1192 IF_PAR_DEBUG(fish, // schedule,
1193 debugBelch("==^^ no local sparks (spark pool contains only NFs: %d)\n",
1194 spark_queue_len(pool)));
1195 return rtsFalse; /* failed to generate a thread */
1197 return rtsTrue; /* success in generating a thread */
1198 } else { /* no more threads permitted or pool empty */
1199 return rtsFalse; /* failed to generateThread */
1202 tso = NULL; // avoid compiler warning only
1203 return rtsFalse; /* dummy in non-PAR setup */
1206 #endif // PARALLEL_HASKELL
1208 /* ----------------------------------------------------------------------------
1209 * Get work from a remote node (PARALLEL_HASKELL only)
1210 * ------------------------------------------------------------------------- */
1212 #if defined(PARALLEL_HASKELL)
1214 scheduleGetRemoteWork(rtsBool *receivedFinish)
1216 ASSERT(emptyRunQueue());
1218 if (RtsFlags.ParFlags.BufferTime) {
1219 IF_PAR_DEBUG(verbose,
1220 debugBelch("...send all pending data,"));
1223 for (i=1; i<=nPEs; i++)
1224 sendImmediately(i); // send all messages away immediately
1228 //++EDEN++ idle() , i.e. send all buffers, wait for work
1229 // suppress fishing in EDEN... just look for incoming messages
1230 // (blocking receive)
1231 IF_PAR_DEBUG(verbose,
1232 debugBelch("...wait for incoming messages...\n"));
1233 *receivedFinish = processMessages(); // blocking receive...
1235 // and reenter scheduling loop after having received something
1236 // (return rtsFalse below)
1238 # else /* activate SPARKS machinery */
1239 /* We get here, if we have no work, tried to activate a local spark, but still
1240 have no work. We try to get a remote spark, by sending a FISH message.
1241 Thread migration should be added here, and triggered when a sequence of
1242 fishes returns without work. */
1243 delay = (RtsFlags.ParFlags.fishDelay!=0ll ? RtsFlags.ParFlags.fishDelay : 0ll);
1245 /* =8-[ no local sparks => look for work on other PEs */
1247 * We really have absolutely no work. Send out a fish
1248 * (there may be some out there already), and wait for
1249 * something to arrive. We clearly can't run any threads
1250 * until a SCHEDULE or RESUME arrives, and so that's what
1251 * we're hoping to see. (Of course, we still have to
1252 * respond to other types of messages.)
1254 rtsTime now = msTime() /*CURRENT_TIME*/;
1255 IF_PAR_DEBUG(verbose,
1256 debugBelch("-- now=%ld\n", now));
1257 IF_PAR_DEBUG(fish, // verbose,
1258 if (outstandingFishes < RtsFlags.ParFlags.maxFishes &&
1259 (last_fish_arrived_at!=0 &&
1260 last_fish_arrived_at+delay > now)) {
1261 debugBelch("--$$ <%llu> delaying FISH until %llu (last fish %llu, delay %llu)\n",
1262 now, last_fish_arrived_at+delay,
1263 last_fish_arrived_at,
1267 if (outstandingFishes < RtsFlags.ParFlags.maxFishes &&
1268 advisory_thread_count < RtsFlags.ParFlags.maxThreads) { // send a FISH, but when?
1269 if (last_fish_arrived_at==0 ||
1270 (last_fish_arrived_at+delay <= now)) { // send FISH now!
1271 /* outstandingFishes is set in sendFish, processFish;
1272 avoid flooding system with fishes via delay */
1273 next_fish_to_send_at = 0;
1275 /* ToDo: this should be done in the main scheduling loop to avoid the
1276 busy wait here; not so bad if fish delay is very small */
1277 int iq = 0; // DEBUGGING -- HWL
1278 next_fish_to_send_at = last_fish_arrived_at+delay; // remember when to send
1279 /* send a fish when ready, but process messages that arrive in the meantime */
1281 if (PacketsWaiting()) {
1283 *receivedFinish = processMessages();
1286 } while (!*receivedFinish || now<next_fish_to_send_at);
1287 // JB: This means the fish could become obsolete, if we receive
1288 // work. Better check for work again?
1289 // last line: while (!receivedFinish || !haveWork || now<...)
1290 // next line: if (receivedFinish || haveWork )
1292 if (*receivedFinish) // no need to send a FISH if we are finishing anyway
1293 return rtsFalse; // NB: this will leave scheduler loop
1294 // immediately after return!
1296 IF_PAR_DEBUG(fish, // verbose,
1297 debugBelch("--$$ <%llu> sent delayed fish (%d processMessages); active/total threads=%d/%d\n",now,iq,run_queue_len(),advisory_thread_count));
1301 // JB: IMHO, this should all be hidden inside sendFish(...)
1303 sendFish(pe, thisPE, NEW_FISH_AGE, NEW_FISH_HISTORY,
1306 // Global statistics: count no. of fishes
1307 if (RtsFlags.ParFlags.ParStats.Global &&
1308 RtsFlags.GcFlags.giveStats > NO_GC_STATS) {
1309 globalParStats.tot_fish_mess++;
1313 /* delayed fishes must have been sent by now! */
1314 next_fish_to_send_at = 0;
1317 *receivedFinish = processMessages();
1318 # endif /* SPARKS */
1321 /* NB: this function always returns rtsFalse, meaning the scheduler
1322 loop continues with the next iteration;
1324 return code means success in finding work; we enter this function
1325 if there is no local work, thus have to send a fish which takes
1326 time until it arrives with work; in the meantime we should process
1327 messages in the main loop;
1330 #endif // PARALLEL_HASKELL
1332 /* ----------------------------------------------------------------------------
1333 * PAR/GRAN: Report stats & debugging info(?)
1334 * ------------------------------------------------------------------------- */
1336 #if defined(PAR) || defined(GRAN)
1338 scheduleGranParReport(void)
1340 ASSERT(run_queue_hd != END_TSO_QUEUE);
1342 /* Take a thread from the run queue, if we have work */
1343 POP_RUN_QUEUE(t); // take_off_run_queue(END_TSO_QUEUE);
1345 /* If this TSO has got its outport closed in the meantime,
1346 * it mustn't be run. Instead, we have to clean it up as if it was finished.
1347 * It has to be marked as TH_DEAD for this purpose.
1348 * If it is TH_TERM instead, it is supposed to have finished in the normal way.
1350 JB: TODO: investigate wether state change field could be nuked
1351 entirely and replaced by the normal tso state (whatnext
1352 field). All we want to do is to kill tsos from outside.
1355 /* ToDo: write something to the log-file
1356 if (RTSflags.ParFlags.granSimStats && !sameThread)
1357 DumpGranEvent(GR_SCHEDULE, RunnableThreadsHd);
1361 /* the spark pool for the current PE */
1362 pool = &(cap.r.rSparks); // cap = (old) MainCap
1365 debugBelch("--=^ %d threads, %d sparks on [%#x]\n",
1366 run_queue_len(), spark_queue_len(pool), CURRENT_PROC));
1369 debugBelch("--=^ %d threads, %d sparks on [%#x]\n",
1370 run_queue_len(), spark_queue_len(pool), CURRENT_PROC));
1372 if (RtsFlags.ParFlags.ParStats.Full &&
1373 (t->par.sparkname != (StgInt)0) && // only log spark generated threads
1374 (emitSchedule || // forced emit
1375 (t && LastTSO && t->id != LastTSO->id))) {
1377 we are running a different TSO, so write a schedule event to log file
1378 NB: If we use fair scheduling we also have to write a deschedule
1379 event for LastTSO; with unfair scheduling we know that the
1380 previous tso has blocked whenever we switch to another tso, so
1381 we don't need it in GUM for now
1383 IF_PAR_DEBUG(fish, // schedule,
1384 debugBelch("____ scheduling spark generated thread %d (%lx) (%lx) via a forced emit\n",t->id,t,t->par.sparkname));
1386 DumpRawGranEvent(CURRENT_PROC, CURRENT_PROC,
1387 GR_SCHEDULE, t, (StgClosure *)NULL, 0, 0);
1388 emitSchedule = rtsFalse;
1393 /* ----------------------------------------------------------------------------
1394 * After running a thread...
1395 * ------------------------------------------------------------------------- */
1398 schedulePostRunThread(void)
1401 /* HACK 675: if the last thread didn't yield, make sure to print a
1402 SCHEDULE event to the log file when StgRunning the next thread, even
1403 if it is the same one as before */
1405 TimeOfLastYield = CURRENT_TIME;
1408 /* some statistics gathering in the parallel case */
1410 #if defined(GRAN) || defined(PAR) || defined(EDEN)
1414 IF_DEBUG(gran, DumpGranEvent(GR_DESCHEDULE, t));
1415 globalGranStats.tot_heapover++;
1417 globalParStats.tot_heapover++;
1424 DumpGranEvent(GR_DESCHEDULE, t));
1425 globalGranStats.tot_stackover++;
1428 // DumpGranEvent(GR_DESCHEDULE, t);
1429 globalParStats.tot_stackover++;
1433 case ThreadYielding:
1436 DumpGranEvent(GR_DESCHEDULE, t));
1437 globalGranStats.tot_yields++;
1440 // DumpGranEvent(GR_DESCHEDULE, t);
1441 globalParStats.tot_yields++;
1448 debugBelch("--<< thread %ld (%p; %s) stopped, blocking on node %p [PE %d] with BQ: ",
1449 t->id, t, whatNext_strs[t->what_next], t->block_info.closure,
1450 (t->block_info.closure==(StgClosure*)NULL ? 99 : where_is(t->block_info.closure)));
1451 if (t->block_info.closure!=(StgClosure*)NULL)
1452 print_bq(t->block_info.closure);
1455 // ??? needed; should emit block before
1457 DumpGranEvent(GR_DESCHEDULE, t));
1458 prune_eventq(t, (StgClosure *)NULL); // prune ContinueThreads for t
1461 ASSERT(procStatus[CurrentProc]==Busy ||
1462 ((procStatus[CurrentProc]==Fetching) &&
1463 (t->block_info.closure!=(StgClosure*)NULL)));
1464 if (run_queue_hds[CurrentProc] == END_TSO_QUEUE &&
1465 !(!RtsFlags.GranFlags.DoAsyncFetch &&
1466 procStatus[CurrentProc]==Fetching))
1467 procStatus[CurrentProc] = Idle;
1470 //++PAR++ blockThread() writes the event (change?)
1474 case ThreadFinished:
1478 barf("parGlobalStats: unknown return code");
1484 /* -----------------------------------------------------------------------------
1485 * Handle a thread that returned to the scheduler with ThreadHeepOverflow
1486 * -------------------------------------------------------------------------- */
1489 scheduleHandleHeapOverflow( Capability *cap, StgTSO *t )
1491 // did the task ask for a large block?
1492 if (cap->r.rHpAlloc > BLOCK_SIZE) {
1493 // if so, get one and push it on the front of the nursery.
1497 blocks = (lnat)BLOCK_ROUND_UP(cap->r.rHpAlloc) / BLOCK_SIZE;
1500 debugBelch("--<< thread %ld (%s) stopped: requesting a large block (size %ld)\n",
1501 (long)t->id, whatNext_strs[t->what_next], blocks));
1503 // don't do this if the nursery is (nearly) full, we'll GC first.
1504 if (cap->r.rCurrentNursery->link != NULL ||
1505 cap->r.rNursery->n_blocks == 1) { // paranoia to prevent infinite loop
1506 // if the nursery has only one block.
1509 bd = allocGroup( blocks );
1511 cap->r.rNursery->n_blocks += blocks;
1513 // link the new group into the list
1514 bd->link = cap->r.rCurrentNursery;
1515 bd->u.back = cap->r.rCurrentNursery->u.back;
1516 if (cap->r.rCurrentNursery->u.back != NULL) {
1517 cap->r.rCurrentNursery->u.back->link = bd;
1519 #if !defined(THREADED_RTS)
1520 ASSERT(g0s0->blocks == cap->r.rCurrentNursery &&
1521 g0s0 == cap->r.rNursery);
1523 cap->r.rNursery->blocks = bd;
1525 cap->r.rCurrentNursery->u.back = bd;
1527 // initialise it as a nursery block. We initialise the
1528 // step, gen_no, and flags field of *every* sub-block in
1529 // this large block, because this is easier than making
1530 // sure that we always find the block head of a large
1531 // block whenever we call Bdescr() (eg. evacuate() and
1532 // isAlive() in the GC would both have to do this, at
1536 for (x = bd; x < bd + blocks; x++) {
1537 x->step = cap->r.rNursery;
1543 // This assert can be a killer if the app is doing lots
1544 // of large block allocations.
1545 IF_DEBUG(sanity, checkNurserySanity(cap->r.rNursery));
1547 // now update the nursery to point to the new block
1548 cap->r.rCurrentNursery = bd;
1550 // we might be unlucky and have another thread get on the
1551 // run queue before us and steal the large block, but in that
1552 // case the thread will just end up requesting another large
1554 pushOnRunQueue(cap,t);
1555 return rtsFalse; /* not actually GC'ing */
1560 debugBelch("--<< thread %ld (%s) stopped: HeapOverflow\n",
1561 (long)t->id, whatNext_strs[t->what_next]));
1563 ASSERT(!is_on_queue(t,CurrentProc));
1564 #elif defined(PARALLEL_HASKELL)
1565 /* Currently we emit a DESCHEDULE event before GC in GUM.
1566 ToDo: either add separate event to distinguish SYSTEM time from rest
1567 or just nuke this DESCHEDULE (and the following SCHEDULE) */
1568 if (0 && RtsFlags.ParFlags.ParStats.Full) {
1569 DumpRawGranEvent(CURRENT_PROC, CURRENT_PROC,
1570 GR_DESCHEDULE, t, (StgClosure *)NULL, 0, 0);
1571 emitSchedule = rtsTrue;
1575 pushOnRunQueue(cap,t);
1577 /* actual GC is done at the end of the while loop in schedule() */
1580 /* -----------------------------------------------------------------------------
1581 * Handle a thread that returned to the scheduler with ThreadStackOverflow
1582 * -------------------------------------------------------------------------- */
1585 scheduleHandleStackOverflow (Capability *cap, Task *task, StgTSO *t)
1587 IF_DEBUG(scheduler,debugBelch("--<< thread %ld (%s) stopped, StackOverflow\n",
1588 (long)t->id, whatNext_strs[t->what_next]));
1589 /* just adjust the stack for this thread, then pop it back
1593 /* enlarge the stack */
1594 StgTSO *new_t = threadStackOverflow(cap, t);
1596 /* The TSO attached to this Task may have moved, so update the
1599 if (task->tso == t) {
1602 pushOnRunQueue(cap,new_t);
1606 /* -----------------------------------------------------------------------------
1607 * Handle a thread that returned to the scheduler with ThreadYielding
1608 * -------------------------------------------------------------------------- */
1611 scheduleHandleYield( Capability *cap, StgTSO *t, nat prev_what_next )
1613 // Reset the context switch flag. We don't do this just before
1614 // running the thread, because that would mean we would lose ticks
1615 // during GC, which can lead to unfair scheduling (a thread hogs
1616 // the CPU because the tick always arrives during GC). This way
1617 // penalises threads that do a lot of allocation, but that seems
1618 // better than the alternative.
1621 /* put the thread back on the run queue. Then, if we're ready to
1622 * GC, check whether this is the last task to stop. If so, wake
1623 * up the GC thread. getThread will block during a GC until the
1627 if (t->what_next != prev_what_next) {
1628 debugBelch("--<< thread %ld (%s) stopped to switch evaluators\n",
1629 (long)t->id, whatNext_strs[t->what_next]);
1631 debugBelch("--<< thread %ld (%s) stopped, yielding\n",
1632 (long)t->id, whatNext_strs[t->what_next]);
1637 //debugBelch("&& Doing sanity check on yielding TSO %ld.", t->id);
1639 ASSERT(t->link == END_TSO_QUEUE);
1641 // Shortcut if we're just switching evaluators: don't bother
1642 // doing stack squeezing (which can be expensive), just run the
1644 if (t->what_next != prev_what_next) {
1649 ASSERT(!is_on_queue(t,CurrentProc));
1652 //debugBelch("&& Doing sanity check on all ThreadQueues (and their TSOs).");
1653 checkThreadQsSanity(rtsTrue));
1657 addToRunQueue(cap,t);
1660 /* add a ContinueThread event to actually process the thread */
1661 new_event(CurrentProc, CurrentProc, CurrentTime[CurrentProc],
1663 t, (StgClosure*)NULL, (rtsSpark*)NULL);
1665 debugBelch("GRAN: eventq and runnableq after adding yielded thread to queue again:\n");
1672 /* -----------------------------------------------------------------------------
1673 * Handle a thread that returned to the scheduler with ThreadBlocked
1674 * -------------------------------------------------------------------------- */
1677 scheduleHandleThreadBlocked( StgTSO *t
1678 #if !defined(GRAN) && !defined(DEBUG)
1685 debugBelch("--<< thread %ld (%p; %s) stopped, blocking on node %p [PE %d] with BQ: \n",
1686 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)));
1687 if (t->block_info.closure!=(StgClosure*)NULL) print_bq(t->block_info.closure));
1689 // ??? needed; should emit block before
1691 DumpGranEvent(GR_DESCHEDULE, t));
1692 prune_eventq(t, (StgClosure *)NULL); // prune ContinueThreads for t
1695 ASSERT(procStatus[CurrentProc]==Busy ||
1696 ((procStatus[CurrentProc]==Fetching) &&
1697 (t->block_info.closure!=(StgClosure*)NULL)));
1698 if (run_queue_hds[CurrentProc] == END_TSO_QUEUE &&
1699 !(!RtsFlags.GranFlags.DoAsyncFetch &&
1700 procStatus[CurrentProc]==Fetching))
1701 procStatus[CurrentProc] = Idle;
1705 debugBelch("--<< thread %ld (%p; %s) stopped, blocking on node %p with BQ: \n",
1706 t->id, t, whatNext_strs[t->what_next], t->block_info.closure));
1709 if (t->block_info.closure!=(StgClosure*)NULL)
1710 print_bq(t->block_info.closure));
1712 /* Send a fetch (if BlockedOnGA) and dump event to log file */
1715 /* whatever we schedule next, we must log that schedule */
1716 emitSchedule = rtsTrue;
1720 // We don't need to do anything. The thread is blocked, and it
1721 // has tidied up its stack and placed itself on whatever queue
1722 // it needs to be on.
1724 #if !defined(THREADED_RTS)
1725 ASSERT(t->why_blocked != NotBlocked);
1726 // This might not be true under THREADED_RTS: we don't have
1727 // exclusive access to this TSO, so someone might have
1728 // woken it up by now. This actually happens: try
1729 // conc023 +RTS -N2.
1733 debugBelch("--<< thread %d (%s) stopped: ",
1734 t->id, whatNext_strs[t->what_next]);
1735 printThreadBlockage(t);
1738 /* Only for dumping event to log file
1739 ToDo: do I need this in GranSim, too?
1745 /* -----------------------------------------------------------------------------
1746 * Handle a thread that returned to the scheduler with ThreadFinished
1747 * -------------------------------------------------------------------------- */
1750 scheduleHandleThreadFinished (Capability *cap STG_UNUSED, Task *task, StgTSO *t)
1752 /* Need to check whether this was a main thread, and if so,
1753 * return with the return value.
1755 * We also end up here if the thread kills itself with an
1756 * uncaught exception, see Exception.cmm.
1758 IF_DEBUG(scheduler,debugBelch("--++ thread %d (%s) finished\n",
1759 t->id, whatNext_strs[t->what_next]));
1762 endThread(t, CurrentProc); // clean-up the thread
1763 #elif defined(PARALLEL_HASKELL)
1764 /* For now all are advisory -- HWL */
1765 //if(t->priority==AdvisoryPriority) ??
1766 advisory_thread_count--; // JB: Caution with this counter, buggy!
1769 if(t->dist.priority==RevalPriority)
1773 # if defined(EDENOLD)
1774 // the thread could still have an outport... (BUG)
1775 if (t->eden.outport != -1) {
1776 // delete the outport for the tso which has finished...
1777 IF_PAR_DEBUG(eden_ports,
1778 debugBelch("WARNING: Scheduler removes outport %d for TSO %d.\n",
1779 t->eden.outport, t->id));
1782 // thread still in the process (HEAVY BUG! since outport has just been closed...)
1783 if (t->eden.epid != -1) {
1784 IF_PAR_DEBUG(eden_ports,
1785 debugBelch("WARNING: Scheduler removes TSO %d from process %d .\n",
1786 t->id, t->eden.epid));
1787 removeTSOfromProcess(t);
1792 if (RtsFlags.ParFlags.ParStats.Full &&
1793 !RtsFlags.ParFlags.ParStats.Suppressed)
1794 DumpEndEvent(CURRENT_PROC, t, rtsFalse /* not mandatory */);
1796 // t->par only contains statistics: left out for now...
1798 debugBelch("**** end thread: ended sparked thread %d (%lx); sparkname: %lx\n",
1799 t->id,t,t->par.sparkname));
1801 #endif // PARALLEL_HASKELL
1804 // Check whether the thread that just completed was a bound
1805 // thread, and if so return with the result.
1807 // There is an assumption here that all thread completion goes
1808 // through this point; we need to make sure that if a thread
1809 // ends up in the ThreadKilled state, that it stays on the run
1810 // queue so it can be dealt with here.
1815 if (t->bound != task) {
1816 #if !defined(THREADED_RTS)
1817 // Must be a bound thread that is not the topmost one. Leave
1818 // it on the run queue until the stack has unwound to the
1819 // point where we can deal with this. Leaving it on the run
1820 // queue also ensures that the garbage collector knows about
1821 // this thread and its return value (it gets dropped from the
1822 // all_threads list so there's no other way to find it).
1823 appendToRunQueue(cap,t);
1826 // this cannot happen in the threaded RTS, because a
1827 // bound thread can only be run by the appropriate Task.
1828 barf("finished bound thread that isn't mine");
1832 ASSERT(task->tso == t);
1834 if (t->what_next == ThreadComplete) {
1836 // NOTE: return val is tso->sp[1] (see StgStartup.hc)
1837 *(task->ret) = (StgClosure *)task->tso->sp[1];
1839 task->stat = Success;
1842 *(task->ret) = NULL;
1845 task->stat = Interrupted;
1847 task->stat = Killed;
1851 removeThreadLabel((StgWord)task->tso->id);
1853 return rtsTrue; // tells schedule() to return
1859 /* -----------------------------------------------------------------------------
1860 * Perform a heap census, if PROFILING
1861 * -------------------------------------------------------------------------- */
1864 scheduleDoHeapProfile( rtsBool ready_to_gc STG_UNUSED )
1866 #if defined(PROFILING)
1867 // When we have +RTS -i0 and we're heap profiling, do a census at
1868 // every GC. This lets us get repeatable runs for debugging.
1869 if (performHeapProfile ||
1870 (RtsFlags.ProfFlags.profileInterval==0 &&
1871 RtsFlags.ProfFlags.doHeapProfile && ready_to_gc)) {
1872 GarbageCollect(GetRoots, rtsTrue);
1874 performHeapProfile = rtsFalse;
1875 return rtsTrue; // true <=> we already GC'd
1881 /* -----------------------------------------------------------------------------
1882 * Perform a garbage collection if necessary
1883 * -------------------------------------------------------------------------- */
1886 scheduleDoGC (Capability *cap, Task *task USED_IF_THREADS,
1887 rtsBool force_major, void (*get_roots)(evac_fn))
1891 static volatile StgWord waiting_for_gc;
1892 rtsBool was_waiting;
1897 // In order to GC, there must be no threads running Haskell code.
1898 // Therefore, the GC thread needs to hold *all* the capabilities,
1899 // and release them after the GC has completed.
1901 // This seems to be the simplest way: previous attempts involved
1902 // making all the threads with capabilities give up their
1903 // capabilities and sleep except for the *last* one, which
1904 // actually did the GC. But it's quite hard to arrange for all
1905 // the other tasks to sleep and stay asleep.
1908 was_waiting = cas(&waiting_for_gc, 0, 1);
1911 IF_DEBUG(scheduler, sched_belch("someone else is trying to GC..."));
1912 if (cap) yieldCapability(&cap,task);
1913 } while (waiting_for_gc);
1914 return; // NOTE: task->cap might have changed here
1917 for (i=0; i < n_capabilities; i++) {
1918 IF_DEBUG(scheduler, sched_belch("ready_to_gc, grabbing all the capabilies (%d/%d)", i, n_capabilities));
1919 if (cap != &capabilities[i]) {
1920 Capability *pcap = &capabilities[i];
1921 // we better hope this task doesn't get migrated to
1922 // another Capability while we're waiting for this one.
1923 // It won't, because load balancing happens while we have
1924 // all the Capabilities, but even so it's a slightly
1925 // unsavoury invariant.
1928 waitForReturnCapability(&pcap, task);
1929 if (pcap != &capabilities[i]) {
1930 barf("scheduleDoGC: got the wrong capability");
1935 waiting_for_gc = rtsFalse;
1938 /* Kick any transactions which are invalid back to their
1939 * atomically frames. When next scheduled they will try to
1940 * commit, this commit will fail and they will retry.
1945 for (t = all_threads; t != END_TSO_QUEUE; t = next) {
1946 if (t->what_next == ThreadRelocated) {
1949 next = t->global_link;
1950 if (t -> trec != NO_TREC && t -> why_blocked == NotBlocked) {
1951 if (!stmValidateNestOfTransactions (t -> trec)) {
1952 IF_DEBUG(stm, sched_belch("trec %p found wasting its time", t));
1954 // strip the stack back to the
1955 // ATOMICALLY_FRAME, aborting the (nested)
1956 // transaction, and saving the stack of any
1957 // partially-evaluated thunks on the heap.
1958 raiseAsync_(&capabilities[0], t, NULL, rtsTrue, NULL);
1961 ASSERT(get_itbl((StgClosure *)t->sp)->type == ATOMICALLY_FRAME);
1969 // so this happens periodically:
1970 if (cap) scheduleCheckBlackHoles(cap);
1972 IF_DEBUG(scheduler, printAllThreads());
1974 /* everybody back, start the GC.
1975 * Could do it in this thread, or signal a condition var
1976 * to do it in another thread. Either way, we need to
1977 * broadcast on gc_pending_cond afterward.
1979 #if defined(THREADED_RTS)
1980 IF_DEBUG(scheduler,sched_belch("doing GC"));
1982 GarbageCollect(get_roots, force_major);
1984 #if defined(THREADED_RTS)
1985 // release our stash of capabilities.
1986 for (i = 0; i < n_capabilities; i++) {
1987 if (cap != &capabilities[i]) {
1988 task->cap = &capabilities[i];
1989 releaseCapability(&capabilities[i]);
2000 /* add a ContinueThread event to continue execution of current thread */
2001 new_event(CurrentProc, CurrentProc, CurrentTime[CurrentProc],
2003 t, (StgClosure*)NULL, (rtsSpark*)NULL);
2005 debugBelch("GRAN: eventq and runnableq after Garbage collection:\n\n");
2011 /* ---------------------------------------------------------------------------
2012 * rtsSupportsBoundThreads(): is the RTS built to support bound threads?
2013 * used by Control.Concurrent for error checking.
2014 * ------------------------------------------------------------------------- */
2017 rtsSupportsBoundThreads(void)
2019 #if defined(THREADED_RTS)
2026 /* ---------------------------------------------------------------------------
2027 * isThreadBound(tso): check whether tso is bound to an OS thread.
2028 * ------------------------------------------------------------------------- */
2031 isThreadBound(StgTSO* tso USED_IF_THREADS)
2033 #if defined(THREADED_RTS)
2034 return (tso->bound != NULL);
2039 /* ---------------------------------------------------------------------------
2040 * Singleton fork(). Do not copy any running threads.
2041 * ------------------------------------------------------------------------- */
2043 #if !defined(mingw32_HOST_OS)
2044 #define FORKPROCESS_PRIMOP_SUPPORTED
2047 #ifdef FORKPROCESS_PRIMOP_SUPPORTED
2049 deleteThreadImmediately(Capability *cap, StgTSO *tso);
2052 forkProcess(HsStablePtr *entry
2053 #ifndef FORKPROCESS_PRIMOP_SUPPORTED
2058 #ifdef FORKPROCESS_PRIMOP_SUPPORTED
2064 #if defined(THREADED_RTS)
2065 if (RtsFlags.ParFlags.nNodes > 1) {
2066 errorBelch("forking not supported with +RTS -N<n> greater than 1");
2067 stg_exit(EXIT_FAILURE);
2071 IF_DEBUG(scheduler,sched_belch("forking!"));
2073 // ToDo: for SMP, we should probably acquire *all* the capabilities
2078 if (pid) { // parent
2080 // just return the pid
2086 // delete all threads
2087 cap->run_queue_hd = END_TSO_QUEUE;
2088 cap->run_queue_tl = END_TSO_QUEUE;
2090 for (t = all_threads; t != END_TSO_QUEUE; t = next) {
2093 // don't allow threads to catch the ThreadKilled exception
2094 deleteThreadImmediately(cap,t);
2097 // wipe the task list
2098 ACQUIRE_LOCK(&sched_mutex);
2099 for (task = all_tasks; task != NULL; task=task->all_link) {
2100 if (task != cap->running_task) discardTask(task);
2102 RELEASE_LOCK(&sched_mutex);
2104 cap->suspended_ccalling_tasks = NULL;
2106 #if defined(THREADED_RTS)
2107 // wipe our spare workers list.
2108 cap->spare_workers = NULL;
2109 cap->returning_tasks_hd = NULL;
2110 cap->returning_tasks_tl = NULL;
2113 cap = rts_evalStableIO(cap, entry, NULL); // run the action
2114 rts_checkSchedStatus("forkProcess",cap);
2117 hs_exit(); // clean up and exit
2118 stg_exit(EXIT_SUCCESS);
2120 #else /* !FORKPROCESS_PRIMOP_SUPPORTED */
2121 barf("forkProcess#: primop not supported on this platform, sorry!\n");
2126 /* ---------------------------------------------------------------------------
2127 * Delete the threads on the run queue of the current capability.
2128 * ------------------------------------------------------------------------- */
2131 deleteRunQueue (Capability *cap)
2134 for (t = cap->run_queue_hd; t != END_TSO_QUEUE; t = next) {
2135 ASSERT(t->what_next != ThreadRelocated);
2137 deleteThread(cap, t);
2141 /* startThread and insertThread are now in GranSim.c -- HWL */
2144 /* -----------------------------------------------------------------------------
2145 Managing the suspended_ccalling_tasks list.
2146 Locks required: sched_mutex
2147 -------------------------------------------------------------------------- */
2150 suspendTask (Capability *cap, Task *task)
2152 ASSERT(task->next == NULL && task->prev == NULL);
2153 task->next = cap->suspended_ccalling_tasks;
2155 if (cap->suspended_ccalling_tasks) {
2156 cap->suspended_ccalling_tasks->prev = task;
2158 cap->suspended_ccalling_tasks = task;
2162 recoverSuspendedTask (Capability *cap, Task *task)
2165 task->prev->next = task->next;
2167 ASSERT(cap->suspended_ccalling_tasks == task);
2168 cap->suspended_ccalling_tasks = task->next;
2171 task->next->prev = task->prev;
2173 task->next = task->prev = NULL;
2176 /* ---------------------------------------------------------------------------
2177 * Suspending & resuming Haskell threads.
2179 * When making a "safe" call to C (aka _ccall_GC), the task gives back
2180 * its capability before calling the C function. This allows another
2181 * task to pick up the capability and carry on running Haskell
2182 * threads. It also means that if the C call blocks, it won't lock
2185 * The Haskell thread making the C call is put to sleep for the
2186 * duration of the call, on the susepended_ccalling_threads queue. We
2187 * give out a token to the task, which it can use to resume the thread
2188 * on return from the C function.
2189 * ------------------------------------------------------------------------- */
2192 suspendThread (StgRegTable *reg)
2195 int saved_errno = errno;
2199 /* assume that *reg is a pointer to the StgRegTable part of a Capability.
2201 cap = regTableToCapability(reg);
2203 task = cap->running_task;
2204 tso = cap->r.rCurrentTSO;
2207 sched_belch("thread %d did a safe foreign call", cap->r.rCurrentTSO->id));
2209 // XXX this might not be necessary --SDM
2210 tso->what_next = ThreadRunGHC;
2212 threadPaused(cap,tso);
2214 if(tso->blocked_exceptions == NULL) {
2215 tso->why_blocked = BlockedOnCCall;
2216 tso->blocked_exceptions = END_TSO_QUEUE;
2218 tso->why_blocked = BlockedOnCCall_NoUnblockExc;
2221 // Hand back capability
2222 task->suspended_tso = tso;
2224 ACQUIRE_LOCK(&cap->lock);
2226 suspendTask(cap,task);
2227 cap->in_haskell = rtsFalse;
2228 releaseCapability_(cap);
2230 RELEASE_LOCK(&cap->lock);
2232 #if defined(THREADED_RTS)
2233 /* Preparing to leave the RTS, so ensure there's a native thread/task
2234 waiting to take over.
2236 IF_DEBUG(scheduler, sched_belch("thread %d: leaving RTS", tso->id));
2239 errno = saved_errno;
2244 resumeThread (void *task_)
2248 int saved_errno = errno;
2252 // Wait for permission to re-enter the RTS with the result.
2253 waitForReturnCapability(&cap,task);
2254 // we might be on a different capability now... but if so, our
2255 // entry on the suspended_ccalling_tasks list will also have been
2258 // Remove the thread from the suspended list
2259 recoverSuspendedTask(cap,task);
2261 tso = task->suspended_tso;
2262 task->suspended_tso = NULL;
2263 tso->link = END_TSO_QUEUE;
2264 IF_DEBUG(scheduler, sched_belch("thread %d: re-entering RTS", tso->id));
2266 if (tso->why_blocked == BlockedOnCCall) {
2267 awakenBlockedQueue(cap,tso->blocked_exceptions);
2268 tso->blocked_exceptions = NULL;
2271 /* Reset blocking status */
2272 tso->why_blocked = NotBlocked;
2274 cap->r.rCurrentTSO = tso;
2275 cap->in_haskell = rtsTrue;
2276 errno = saved_errno;
2278 /* We might have GC'd, mark the TSO dirty again */
2284 /* ---------------------------------------------------------------------------
2285 * Comparing Thread ids.
2287 * This is used from STG land in the implementation of the
2288 * instances of Eq/Ord for ThreadIds.
2289 * ------------------------------------------------------------------------ */
2292 cmp_thread(StgPtr tso1, StgPtr tso2)
2294 StgThreadID id1 = ((StgTSO *)tso1)->id;
2295 StgThreadID id2 = ((StgTSO *)tso2)->id;
2297 if (id1 < id2) return (-1);
2298 if (id1 > id2) return 1;
2302 /* ---------------------------------------------------------------------------
2303 * Fetching the ThreadID from an StgTSO.
2305 * This is used in the implementation of Show for ThreadIds.
2306 * ------------------------------------------------------------------------ */
2308 rts_getThreadId(StgPtr tso)
2310 return ((StgTSO *)tso)->id;
2315 labelThread(StgPtr tso, char *label)
2320 /* Caveat: Once set, you can only set the thread name to "" */
2321 len = strlen(label)+1;
2322 buf = stgMallocBytes(len * sizeof(char), "Schedule.c:labelThread()");
2323 strncpy(buf,label,len);
2324 /* Update will free the old memory for us */
2325 updateThreadLabel(((StgTSO *)tso)->id,buf);
2329 /* ---------------------------------------------------------------------------
2330 Create a new thread.
2332 The new thread starts with the given stack size. Before the
2333 scheduler can run, however, this thread needs to have a closure
2334 (and possibly some arguments) pushed on its stack. See
2335 pushClosure() in Schedule.h.
2337 createGenThread() and createIOThread() (in SchedAPI.h) are
2338 convenient packaged versions of this function.
2340 currently pri (priority) is only used in a GRAN setup -- HWL
2341 ------------------------------------------------------------------------ */
2343 /* currently pri (priority) is only used in a GRAN setup -- HWL */
2345 createThread(nat size, StgInt pri)
2348 createThread(Capability *cap, nat size)
2354 /* sched_mutex is *not* required */
2356 /* First check whether we should create a thread at all */
2357 #if defined(PARALLEL_HASKELL)
2358 /* check that no more than RtsFlags.ParFlags.maxThreads threads are created */
2359 if (advisory_thread_count >= RtsFlags.ParFlags.maxThreads) {
2361 debugBelch("{createThread}Daq ghuH: refusing to create another thread; no more than %d threads allowed (currently %d)\n",
2362 RtsFlags.ParFlags.maxThreads, advisory_thread_count);
2363 return END_TSO_QUEUE;
2369 ASSERT(!RtsFlags.GranFlags.Light || CurrentProc==0);
2372 // ToDo: check whether size = stack_size - TSO_STRUCT_SIZEW
2374 /* catch ridiculously small stack sizes */
2375 if (size < MIN_STACK_WORDS + TSO_STRUCT_SIZEW) {
2376 size = MIN_STACK_WORDS + TSO_STRUCT_SIZEW;
2379 stack_size = size - TSO_STRUCT_SIZEW;
2381 tso = (StgTSO *)allocateLocal(cap, size);
2382 TICK_ALLOC_TSO(stack_size, 0);
2384 SET_HDR(tso, &stg_TSO_info, CCS_SYSTEM);
2386 SET_GRAN_HDR(tso, ThisPE);
2389 // Always start with the compiled code evaluator
2390 tso->what_next = ThreadRunGHC;
2392 tso->why_blocked = NotBlocked;
2393 tso->blocked_exceptions = NULL;
2394 tso->flags = TSO_DIRTY;
2396 tso->saved_errno = 0;
2399 tso->stack_size = stack_size;
2400 tso->max_stack_size = round_to_mblocks(RtsFlags.GcFlags.maxStkSize)
2402 tso->sp = (P_)&(tso->stack) + stack_size;
2404 tso->trec = NO_TREC;
2407 tso->prof.CCCS = CCS_MAIN;
2410 /* put a stop frame on the stack */
2411 tso->sp -= sizeofW(StgStopFrame);
2412 SET_HDR((StgClosure*)tso->sp,(StgInfoTable *)&stg_stop_thread_info,CCS_SYSTEM);
2413 tso->link = END_TSO_QUEUE;
2417 /* uses more flexible routine in GranSim */
2418 insertThread(tso, CurrentProc);
2420 /* In a non-GranSim setup the pushing of a TSO onto the runq is separated
2426 if (RtsFlags.GranFlags.GranSimStats.Full)
2427 DumpGranEvent(GR_START,tso);
2428 #elif defined(PARALLEL_HASKELL)
2429 if (RtsFlags.ParFlags.ParStats.Full)
2430 DumpGranEvent(GR_STARTQ,tso);
2431 /* HACk to avoid SCHEDULE
2435 /* Link the new thread on the global thread list.
2437 ACQUIRE_LOCK(&sched_mutex);
2438 tso->id = next_thread_id++; // while we have the mutex
2439 tso->global_link = all_threads;
2441 RELEASE_LOCK(&sched_mutex);
2444 tso->dist.priority = MandatoryPriority; //by default that is...
2448 tso->gran.pri = pri;
2450 tso->gran.magic = TSO_MAGIC; // debugging only
2452 tso->gran.sparkname = 0;
2453 tso->gran.startedat = CURRENT_TIME;
2454 tso->gran.exported = 0;
2455 tso->gran.basicblocks = 0;
2456 tso->gran.allocs = 0;
2457 tso->gran.exectime = 0;
2458 tso->gran.fetchtime = 0;
2459 tso->gran.fetchcount = 0;
2460 tso->gran.blocktime = 0;
2461 tso->gran.blockcount = 0;
2462 tso->gran.blockedat = 0;
2463 tso->gran.globalsparks = 0;
2464 tso->gran.localsparks = 0;
2465 if (RtsFlags.GranFlags.Light)
2466 tso->gran.clock = Now; /* local clock */
2468 tso->gran.clock = 0;
2470 IF_DEBUG(gran,printTSO(tso));
2471 #elif defined(PARALLEL_HASKELL)
2473 tso->par.magic = TSO_MAGIC; // debugging only
2475 tso->par.sparkname = 0;
2476 tso->par.startedat = CURRENT_TIME;
2477 tso->par.exported = 0;
2478 tso->par.basicblocks = 0;
2479 tso->par.allocs = 0;
2480 tso->par.exectime = 0;
2481 tso->par.fetchtime = 0;
2482 tso->par.fetchcount = 0;
2483 tso->par.blocktime = 0;
2484 tso->par.blockcount = 0;
2485 tso->par.blockedat = 0;
2486 tso->par.globalsparks = 0;
2487 tso->par.localsparks = 0;
2491 globalGranStats.tot_threads_created++;
2492 globalGranStats.threads_created_on_PE[CurrentProc]++;
2493 globalGranStats.tot_sq_len += spark_queue_len(CurrentProc);
2494 globalGranStats.tot_sq_probes++;
2495 #elif defined(PARALLEL_HASKELL)
2496 // collect parallel global statistics (currently done together with GC stats)
2497 if (RtsFlags.ParFlags.ParStats.Global &&
2498 RtsFlags.GcFlags.giveStats > NO_GC_STATS) {
2499 //debugBelch("Creating thread %d @ %11.2f\n", tso->id, usertime());
2500 globalParStats.tot_threads_created++;
2506 sched_belch("==__ schedule: Created TSO %d (%p);",
2507 CurrentProc, tso, tso->id));
2508 #elif defined(PARALLEL_HASKELL)
2509 IF_PAR_DEBUG(verbose,
2510 sched_belch("==__ schedule: Created TSO %d (%p); %d threads active",
2511 (long)tso->id, tso, advisory_thread_count));
2513 IF_DEBUG(scheduler,sched_belch("created thread %ld, stack size = %lx words",
2514 (long)tso->id, (long)tso->stack_size));
2521 all parallel thread creation calls should fall through the following routine.
2524 createThreadFromSpark(rtsSpark spark)
2526 ASSERT(spark != (rtsSpark)NULL);
2527 // JB: TAKE CARE OF THIS COUNTER! BUGGY
2528 if (advisory_thread_count >= RtsFlags.ParFlags.maxThreads)
2530 barf("{createSparkThread}Daq ghuH: refusing to create another thread; no more than %d threads allowed (currently %d)",
2531 RtsFlags.ParFlags.maxThreads, advisory_thread_count);
2532 return END_TSO_QUEUE;
2536 tso = createThread(RtsFlags.GcFlags.initialStkSize);
2537 if (tso==END_TSO_QUEUE)
2538 barf("createSparkThread: Cannot create TSO");
2540 tso->priority = AdvisoryPriority;
2542 pushClosure(tso,spark);
2544 advisory_thread_count++; // JB: TAKE CARE OF THIS COUNTER! BUGGY
2551 Turn a spark into a thread.
2552 ToDo: fix for SMP (needs to acquire SCHED_MUTEX!)
2556 activateSpark (rtsSpark spark)
2560 tso = createSparkThread(spark);
2561 if (RtsFlags.ParFlags.ParStats.Full) {
2562 //ASSERT(run_queue_hd == END_TSO_QUEUE); // I think ...
2563 IF_PAR_DEBUG(verbose,
2564 debugBelch("==^^ activateSpark: turning spark of closure %p (%s) into a thread\n",
2565 (StgClosure *)spark, info_type((StgClosure *)spark)));
2567 // ToDo: fwd info on local/global spark to thread -- HWL
2568 // tso->gran.exported = spark->exported;
2569 // tso->gran.locked = !spark->global;
2570 // tso->gran.sparkname = spark->name;
2576 /* ---------------------------------------------------------------------------
2579 * scheduleThread puts a thread on the end of the runnable queue.
2580 * This will usually be done immediately after a thread is created.
2581 * The caller of scheduleThread must create the thread using e.g.
2582 * createThread and push an appropriate closure
2583 * on this thread's stack before the scheduler is invoked.
2584 * ------------------------------------------------------------------------ */
2587 scheduleThread(Capability *cap, StgTSO *tso)
2589 // The thread goes at the *end* of the run-queue, to avoid possible
2590 // starvation of any threads already on the queue.
2591 appendToRunQueue(cap,tso);
2595 scheduleWaitThread (StgTSO* tso, /*[out]*/HaskellObj* ret, Capability *cap)
2599 // We already created/initialised the Task
2600 task = cap->running_task;
2602 // This TSO is now a bound thread; make the Task and TSO
2603 // point to each other.
2608 task->stat = NoStatus;
2610 appendToRunQueue(cap,tso);
2612 IF_DEBUG(scheduler, sched_belch("new bound thread (%d)", tso->id));
2615 /* GranSim specific init */
2616 CurrentTSO = m->tso; // the TSO to run
2617 procStatus[MainProc] = Busy; // status of main PE
2618 CurrentProc = MainProc; // PE to run it on
2621 cap = schedule(cap,task);
2623 ASSERT(task->stat != NoStatus);
2624 ASSERT_FULL_CAPABILITY_INVARIANTS(cap,task);
2626 IF_DEBUG(scheduler, sched_belch("bound thread (%d) finished", task->tso->id));
2630 /* ----------------------------------------------------------------------------
2632 * ------------------------------------------------------------------------- */
2634 #if defined(THREADED_RTS)
2636 workerStart(Task *task)
2640 // See startWorkerTask().
2641 ACQUIRE_LOCK(&task->lock);
2643 RELEASE_LOCK(&task->lock);
2645 // set the thread-local pointer to the Task:
2648 // schedule() runs without a lock.
2649 cap = schedule(cap,task);
2651 // On exit from schedule(), we have a Capability.
2652 releaseCapability(cap);
2657 /* ---------------------------------------------------------------------------
2660 * Initialise the scheduler. This resets all the queues - if the
2661 * queues contained any threads, they'll be garbage collected at the
2664 * ------------------------------------------------------------------------ */
2671 for (i=0; i<=MAX_PROC; i++) {
2672 run_queue_hds[i] = END_TSO_QUEUE;
2673 run_queue_tls[i] = END_TSO_QUEUE;
2674 blocked_queue_hds[i] = END_TSO_QUEUE;
2675 blocked_queue_tls[i] = END_TSO_QUEUE;
2676 ccalling_threadss[i] = END_TSO_QUEUE;
2677 blackhole_queue[i] = END_TSO_QUEUE;
2678 sleeping_queue = END_TSO_QUEUE;
2680 #elif !defined(THREADED_RTS)
2681 blocked_queue_hd = END_TSO_QUEUE;
2682 blocked_queue_tl = END_TSO_QUEUE;
2683 sleeping_queue = END_TSO_QUEUE;
2686 blackhole_queue = END_TSO_QUEUE;
2687 all_threads = END_TSO_QUEUE;
2692 RtsFlags.ConcFlags.ctxtSwitchTicks =
2693 RtsFlags.ConcFlags.ctxtSwitchTime / TICK_MILLISECS;
2695 #if defined(THREADED_RTS)
2696 /* Initialise the mutex and condition variables used by
2698 initMutex(&sched_mutex);
2701 ACQUIRE_LOCK(&sched_mutex);
2703 /* A capability holds the state a native thread needs in
2704 * order to execute STG code. At least one capability is
2705 * floating around (only THREADED_RTS builds have more than one).
2711 #if defined(THREADED_RTS) || defined(PARALLEL_HASKELL)
2715 #if defined(THREADED_RTS)
2717 * Eagerly start one worker to run each Capability, except for
2718 * Capability 0. The idea is that we're probably going to start a
2719 * bound thread on Capability 0 pretty soon, so we don't want a
2720 * worker task hogging it.
2725 for (i = 1; i < n_capabilities; i++) {
2726 cap = &capabilities[i];
2727 ACQUIRE_LOCK(&cap->lock);
2728 startWorkerTask(cap, workerStart);
2729 RELEASE_LOCK(&cap->lock);
2734 RELEASE_LOCK(&sched_mutex);
2738 exitScheduler( void )
2740 interrupted = rtsTrue;
2741 shutting_down_scheduler = rtsTrue;
2743 #if defined(THREADED_RTS)
2748 ACQUIRE_LOCK(&sched_mutex);
2749 task = newBoundTask();
2750 RELEASE_LOCK(&sched_mutex);
2752 for (i = 0; i < n_capabilities; i++) {
2753 shutdownCapability(&capabilities[i], task);
2755 boundTaskExiting(task);
2761 /* ---------------------------------------------------------------------------
2762 Where are the roots that we know about?
2764 - all the threads on the runnable queue
2765 - all the threads on the blocked queue
2766 - all the threads on the sleeping queue
2767 - all the thread currently executing a _ccall_GC
2768 - all the "main threads"
2770 ------------------------------------------------------------------------ */
2772 /* This has to be protected either by the scheduler monitor, or by the
2773 garbage collection monitor (probably the latter).
2778 GetRoots( evac_fn evac )
2785 for (i=0; i<=RtsFlags.GranFlags.proc; i++) {
2786 if ((run_queue_hds[i] != END_TSO_QUEUE) && ((run_queue_hds[i] != NULL)))
2787 evac((StgClosure **)&run_queue_hds[i]);
2788 if ((run_queue_tls[i] != END_TSO_QUEUE) && ((run_queue_tls[i] != NULL)))
2789 evac((StgClosure **)&run_queue_tls[i]);
2791 if ((blocked_queue_hds[i] != END_TSO_QUEUE) && ((blocked_queue_hds[i] != NULL)))
2792 evac((StgClosure **)&blocked_queue_hds[i]);
2793 if ((blocked_queue_tls[i] != END_TSO_QUEUE) && ((blocked_queue_tls[i] != NULL)))
2794 evac((StgClosure **)&blocked_queue_tls[i]);
2795 if ((ccalling_threadss[i] != END_TSO_QUEUE) && ((ccalling_threadss[i] != NULL)))
2796 evac((StgClosure **)&ccalling_threads[i]);
2803 for (i = 0; i < n_capabilities; i++) {
2804 cap = &capabilities[i];
2805 evac((StgClosure **)&cap->run_queue_hd);
2806 evac((StgClosure **)&cap->run_queue_tl);
2808 for (task = cap->suspended_ccalling_tasks; task != NULL;
2810 evac((StgClosure **)&task->suspended_tso);
2814 #if !defined(THREADED_RTS)
2815 evac((StgClosure **)(void *)&blocked_queue_hd);
2816 evac((StgClosure **)(void *)&blocked_queue_tl);
2817 evac((StgClosure **)(void *)&sleeping_queue);
2821 // evac((StgClosure **)&blackhole_queue);
2823 #if defined(THREADED_RTS) || defined(PARALLEL_HASKELL) || defined(GRAN)
2824 markSparkQueue(evac);
2827 #if defined(RTS_USER_SIGNALS)
2828 // mark the signal handlers (signals should be already blocked)
2829 markSignalHandlers(evac);
2833 /* -----------------------------------------------------------------------------
2836 This is the interface to the garbage collector from Haskell land.
2837 We provide this so that external C code can allocate and garbage
2838 collect when called from Haskell via _ccall_GC.
2840 It might be useful to provide an interface whereby the programmer
2841 can specify more roots (ToDo).
2843 This needs to be protected by the GC condition variable above. KH.
2844 -------------------------------------------------------------------------- */
2846 static void (*extra_roots)(evac_fn);
2849 performGC_(rtsBool force_major, void (*get_roots)(evac_fn))
2851 Task *task = myTask();
2854 ACQUIRE_LOCK(&sched_mutex);
2855 task = newBoundTask();
2856 RELEASE_LOCK(&sched_mutex);
2857 scheduleDoGC(NULL,task,force_major, get_roots);
2858 boundTaskExiting(task);
2860 scheduleDoGC(NULL,task,force_major, get_roots);
2867 performGC_(rtsFalse, GetRoots);
2871 performMajorGC(void)
2873 performGC_(rtsTrue, GetRoots);
2877 AllRoots(evac_fn evac)
2879 GetRoots(evac); // the scheduler's roots
2880 extra_roots(evac); // the user's roots
2884 performGCWithRoots(void (*get_roots)(evac_fn))
2886 extra_roots = get_roots;
2887 performGC_(rtsFalse, AllRoots);
2890 /* -----------------------------------------------------------------------------
2893 If the thread has reached its maximum stack size, then raise the
2894 StackOverflow exception in the offending thread. Otherwise
2895 relocate the TSO into a larger chunk of memory and adjust its stack
2897 -------------------------------------------------------------------------- */
2900 threadStackOverflow(Capability *cap, StgTSO *tso)
2902 nat new_stack_size, stack_words;
2907 IF_DEBUG(sanity,checkTSO(tso));
2908 if (tso->stack_size >= tso->max_stack_size) {
2911 debugBelch("@@ threadStackOverflow of TSO %ld (%p): stack too large (now %ld; max is %ld)\n",
2912 (long)tso->id, tso, (long)tso->stack_size, (long)tso->max_stack_size);
2913 /* If we're debugging, just print out the top of the stack */
2914 printStackChunk(tso->sp, stg_min(tso->stack+tso->stack_size,
2917 /* Send this thread the StackOverflow exception */
2918 raiseAsync(cap, tso, (StgClosure *)stackOverflow_closure);
2922 /* Try to double the current stack size. If that takes us over the
2923 * maximum stack size for this thread, then use the maximum instead.
2924 * Finally round up so the TSO ends up as a whole number of blocks.
2926 new_stack_size = stg_min(tso->stack_size * 2, tso->max_stack_size);
2927 new_tso_size = (lnat)BLOCK_ROUND_UP(new_stack_size * sizeof(W_) +
2928 TSO_STRUCT_SIZE)/sizeof(W_);
2929 new_tso_size = round_to_mblocks(new_tso_size); /* Be MBLOCK-friendly */
2930 new_stack_size = new_tso_size - TSO_STRUCT_SIZEW;
2932 IF_DEBUG(scheduler, sched_belch("increasing stack size from %ld words to %d.\n", (long)tso->stack_size, new_stack_size));
2934 dest = (StgTSO *)allocate(new_tso_size);
2935 TICK_ALLOC_TSO(new_stack_size,0);
2937 /* copy the TSO block and the old stack into the new area */
2938 memcpy(dest,tso,TSO_STRUCT_SIZE);
2939 stack_words = tso->stack + tso->stack_size - tso->sp;
2940 new_sp = (P_)dest + new_tso_size - stack_words;
2941 memcpy(new_sp, tso->sp, stack_words * sizeof(W_));
2943 /* relocate the stack pointers... */
2945 dest->stack_size = new_stack_size;
2947 /* Mark the old TSO as relocated. We have to check for relocated
2948 * TSOs in the garbage collector and any primops that deal with TSOs.
2950 * It's important to set the sp value to just beyond the end
2951 * of the stack, so we don't attempt to scavenge any part of the
2954 tso->what_next = ThreadRelocated;
2956 tso->sp = (P_)&(tso->stack[tso->stack_size]);
2957 tso->why_blocked = NotBlocked;
2959 IF_PAR_DEBUG(verbose,
2960 debugBelch("@@ threadStackOverflow of TSO %d (now at %p): stack size increased to %ld\n",
2961 tso->id, tso, tso->stack_size);
2962 /* If we're debugging, just print out the top of the stack */
2963 printStackChunk(tso->sp, stg_min(tso->stack+tso->stack_size,
2966 IF_DEBUG(sanity,checkTSO(tso));
2968 IF_DEBUG(scheduler,printTSO(dest));
2974 /* ---------------------------------------------------------------------------
2975 Wake up a queue that was blocked on some resource.
2976 ------------------------------------------------------------------------ */
2980 unblockCount ( StgBlockingQueueElement *bqe, StgClosure *node )
2983 #elif defined(PARALLEL_HASKELL)
2985 unblockCount ( StgBlockingQueueElement *bqe, StgClosure *node )
2987 /* write RESUME events to log file and
2988 update blocked and fetch time (depending on type of the orig closure) */
2989 if (RtsFlags.ParFlags.ParStats.Full) {
2990 DumpRawGranEvent(CURRENT_PROC, CURRENT_PROC,
2991 GR_RESUMEQ, ((StgTSO *)bqe), ((StgTSO *)bqe)->block_info.closure,
2992 0, 0 /* spark_queue_len(ADVISORY_POOL) */);
2993 if (emptyRunQueue())
2994 emitSchedule = rtsTrue;
2996 switch (get_itbl(node)->type) {
2998 ((StgTSO *)bqe)->par.fetchtime += CURRENT_TIME-((StgTSO *)bqe)->par.blockedat;
3003 ((StgTSO *)bqe)->par.blocktime += CURRENT_TIME-((StgTSO *)bqe)->par.blockedat;
3010 barf("{unblockOne}Daq Qagh: unexpected closure in blocking queue");
3017 StgBlockingQueueElement *
3018 unblockOne(StgBlockingQueueElement *bqe, StgClosure *node)
3021 PEs node_loc, tso_loc;
3023 node_loc = where_is(node); // should be lifted out of loop
3024 tso = (StgTSO *)bqe; // wastes an assignment to get the type right
3025 tso_loc = where_is((StgClosure *)tso);
3026 if (IS_LOCAL_TO(PROCS(node),tso_loc)) { // TSO is local
3027 /* !fake_fetch => TSO is on CurrentProc is same as IS_LOCAL_TO */
3028 ASSERT(CurrentProc!=node_loc || tso_loc==CurrentProc);
3029 CurrentTime[CurrentProc] += RtsFlags.GranFlags.Costs.lunblocktime;
3030 // insertThread(tso, node_loc);
3031 new_event(tso_loc, tso_loc, CurrentTime[CurrentProc],
3033 tso, node, (rtsSpark*)NULL);
3034 tso->link = END_TSO_QUEUE; // overwrite link just to be sure
3037 } else { // TSO is remote (actually should be FMBQ)
3038 CurrentTime[CurrentProc] += RtsFlags.GranFlags.Costs.mpacktime +
3039 RtsFlags.GranFlags.Costs.gunblocktime +
3040 RtsFlags.GranFlags.Costs.latency;
3041 new_event(tso_loc, CurrentProc, CurrentTime[CurrentProc],
3043 tso, node, (rtsSpark*)NULL);
3044 tso->link = END_TSO_QUEUE; // overwrite link just to be sure
3047 /* the thread-queue-overhead is accounted for in either Resume or UnblockThread */
3049 debugBelch(" %s TSO %d (%p) [PE %d] (block_info.closure=%p) (next=%p) ,",
3050 (node_loc==tso_loc ? "Local" : "Global"),
3051 tso->id, tso, CurrentProc, tso->block_info.closure, tso->link));
3052 tso->block_info.closure = NULL;
3053 IF_DEBUG(scheduler,debugBelch("-- Waking up thread %ld (%p)\n",
3056 #elif defined(PARALLEL_HASKELL)
3057 StgBlockingQueueElement *
3058 unblockOne(StgBlockingQueueElement *bqe, StgClosure *node)
3060 StgBlockingQueueElement *next;
3062 switch (get_itbl(bqe)->type) {
3064 ASSERT(((StgTSO *)bqe)->why_blocked != NotBlocked);
3065 /* if it's a TSO just push it onto the run_queue */
3067 ((StgTSO *)bqe)->link = END_TSO_QUEUE; // debugging?
3068 APPEND_TO_RUN_QUEUE((StgTSO *)bqe);
3070 unblockCount(bqe, node);
3071 /* reset blocking status after dumping event */
3072 ((StgTSO *)bqe)->why_blocked = NotBlocked;
3076 /* if it's a BLOCKED_FETCH put it on the PendingFetches list */
3078 bqe->link = (StgBlockingQueueElement *)PendingFetches;
3079 PendingFetches = (StgBlockedFetch *)bqe;
3083 /* can ignore this case in a non-debugging setup;
3084 see comments on RBHSave closures above */
3086 /* check that the closure is an RBHSave closure */
3087 ASSERT(get_itbl((StgClosure *)bqe) == &stg_RBH_Save_0_info ||
3088 get_itbl((StgClosure *)bqe) == &stg_RBH_Save_1_info ||
3089 get_itbl((StgClosure *)bqe) == &stg_RBH_Save_2_info);
3093 barf("{unblockOne}Daq Qagh: Unexpected IP (%#lx; %s) in blocking queue at %#lx\n",
3094 get_itbl((StgClosure *)bqe), info_type((StgClosure *)bqe),
3098 IF_PAR_DEBUG(bq, debugBelch(", %p (%s)\n", bqe, info_type((StgClosure*)bqe)));
3104 unblockOne(Capability *cap, StgTSO *tso)
3108 ASSERT(get_itbl(tso)->type == TSO);
3109 ASSERT(tso->why_blocked != NotBlocked);
3110 tso->why_blocked = NotBlocked;
3112 tso->link = END_TSO_QUEUE;
3114 // We might have just migrated this TSO to our Capability:
3116 tso->bound->cap = cap;
3119 appendToRunQueue(cap,tso);
3121 // we're holding a newly woken thread, make sure we context switch
3122 // quickly so we can migrate it if necessary.
3124 IF_DEBUG(scheduler,sched_belch("waking up thread %ld", (long)tso->id));
3131 awakenBlockedQueue(StgBlockingQueueElement *q, StgClosure *node)
3133 StgBlockingQueueElement *bqe;
3138 debugBelch("##-_ AwBQ for node %p on PE %d @ %ld by TSO %d (%p): \n", \
3139 node, CurrentProc, CurrentTime[CurrentProc],
3140 CurrentTSO->id, CurrentTSO));
3142 node_loc = where_is(node);
3144 ASSERT(q == END_BQ_QUEUE ||
3145 get_itbl(q)->type == TSO || // q is either a TSO or an RBHSave
3146 get_itbl(q)->type == CONSTR); // closure (type constructor)
3147 ASSERT(is_unique(node));
3149 /* FAKE FETCH: magically copy the node to the tso's proc;
3150 no Fetch necessary because in reality the node should not have been
3151 moved to the other PE in the first place
3153 if (CurrentProc!=node_loc) {
3155 debugBelch("## node %p is on PE %d but CurrentProc is %d (TSO %d); assuming fake fetch and adjusting bitmask (old: %#x)\n",
3156 node, node_loc, CurrentProc, CurrentTSO->id,
3157 // CurrentTSO, where_is(CurrentTSO),
3158 node->header.gran.procs));
3159 node->header.gran.procs = (node->header.gran.procs) | PE_NUMBER(CurrentProc);
3161 debugBelch("## new bitmask of node %p is %#x\n",
3162 node, node->header.gran.procs));
3163 if (RtsFlags.GranFlags.GranSimStats.Global) {
3164 globalGranStats.tot_fake_fetches++;
3169 // ToDo: check: ASSERT(CurrentProc==node_loc);
3170 while (get_itbl(bqe)->type==TSO) { // q != END_TSO_QUEUE) {
3173 bqe points to the current element in the queue
3174 next points to the next element in the queue
3176 //tso = (StgTSO *)bqe; // wastes an assignment to get the type right
3177 //tso_loc = where_is(tso);
3179 bqe = unblockOne(bqe, node);
3182 /* if this is the BQ of an RBH, we have to put back the info ripped out of
3183 the closure to make room for the anchor of the BQ */
3184 if (bqe!=END_BQ_QUEUE) {
3185 ASSERT(get_itbl(node)->type == RBH && get_itbl(bqe)->type == CONSTR);
3187 ASSERT((info_ptr==&RBH_Save_0_info) ||
3188 (info_ptr==&RBH_Save_1_info) ||
3189 (info_ptr==&RBH_Save_2_info));
3191 /* cf. convertToRBH in RBH.c for writing the RBHSave closure */
3192 ((StgRBH *)node)->blocking_queue = (StgBlockingQueueElement *)((StgRBHSave *)bqe)->payload[0];
3193 ((StgRBH *)node)->mut_link = (StgMutClosure *)((StgRBHSave *)bqe)->payload[1];
3196 debugBelch("## Filled in RBH_Save for %p (%s) at end of AwBQ\n",
3197 node, info_type(node)));
3200 /* statistics gathering */
3201 if (RtsFlags.GranFlags.GranSimStats.Global) {
3202 // globalGranStats.tot_bq_processing_time += bq_processing_time;
3203 globalGranStats.tot_bq_len += len; // total length of all bqs awakened
3204 // globalGranStats.tot_bq_len_local += len_local; // same for local TSOs only
3205 globalGranStats.tot_awbq++; // total no. of bqs awakened
3208 debugBelch("## BQ Stats of %p: [%d entries] %s\n",
3209 node, len, (bqe!=END_BQ_QUEUE) ? "RBH" : ""));
3211 #elif defined(PARALLEL_HASKELL)
3213 awakenBlockedQueue(StgBlockingQueueElement *q, StgClosure *node)
3215 StgBlockingQueueElement *bqe;
3217 IF_PAR_DEBUG(verbose,
3218 debugBelch("##-_ AwBQ for node %p on [%x]: \n",
3222 if(get_itbl(q)->type == CONSTR || q==END_BQ_QUEUE) {
3223 IF_PAR_DEBUG(verbose, debugBelch("## ... nothing to unblock so lets just return. RFP (BUG?)\n"));
3228 ASSERT(q == END_BQ_QUEUE ||
3229 get_itbl(q)->type == TSO ||
3230 get_itbl(q)->type == BLOCKED_FETCH ||
3231 get_itbl(q)->type == CONSTR);
3234 while (get_itbl(bqe)->type==TSO ||
3235 get_itbl(bqe)->type==BLOCKED_FETCH) {
3236 bqe = unblockOne(bqe, node);
3240 #else /* !GRAN && !PARALLEL_HASKELL */
3243 awakenBlockedQueue(Capability *cap, StgTSO *tso)
3245 if (tso == NULL) return; // hack; see bug #1235728, and comments in
3247 while (tso != END_TSO_QUEUE) {
3248 tso = unblockOne(cap,tso);
3253 /* ---------------------------------------------------------------------------
3255 - usually called inside a signal handler so it mustn't do anything fancy.
3256 ------------------------------------------------------------------------ */
3259 interruptStgRts(void)
3263 #if defined(THREADED_RTS)
3264 prodAllCapabilities();
3268 /* -----------------------------------------------------------------------------
3271 This is for use when we raise an exception in another thread, which
3273 This has nothing to do with the UnblockThread event in GranSim. -- HWL
3274 -------------------------------------------------------------------------- */
3276 #if defined(GRAN) || defined(PARALLEL_HASKELL)
3278 NB: only the type of the blocking queue is different in GranSim and GUM
3279 the operations on the queue-elements are the same
3280 long live polymorphism!
3282 Locks: sched_mutex is held upon entry and exit.
3286 unblockThread(Capability *cap, StgTSO *tso)
3288 StgBlockingQueueElement *t, **last;
3290 switch (tso->why_blocked) {
3293 return; /* not blocked */
3296 // Be careful: nothing to do here! We tell the scheduler that the thread
3297 // is runnable and we leave it to the stack-walking code to abort the
3298 // transaction while unwinding the stack. We should perhaps have a debugging
3299 // test to make sure that this really happens and that the 'zombie' transaction
3300 // does not get committed.
3304 ASSERT(get_itbl(tso->block_info.closure)->type == MVAR);
3306 StgBlockingQueueElement *last_tso = END_BQ_QUEUE;
3307 StgMVar *mvar = (StgMVar *)(tso->block_info.closure);
3309 last = (StgBlockingQueueElement **)&mvar->head;
3310 for (t = (StgBlockingQueueElement *)mvar->head;
3312 last = &t->link, last_tso = t, t = t->link) {
3313 if (t == (StgBlockingQueueElement *)tso) {
3314 *last = (StgBlockingQueueElement *)tso->link;
3315 if (mvar->tail == tso) {
3316 mvar->tail = (StgTSO *)last_tso;
3321 barf("unblockThread (MVAR): TSO not found");
3324 case BlockedOnBlackHole:
3325 ASSERT(get_itbl(tso->block_info.closure)->type == BLACKHOLE_BQ);
3327 StgBlockingQueue *bq = (StgBlockingQueue *)(tso->block_info.closure);
3329 last = &bq->blocking_queue;
3330 for (t = bq->blocking_queue;
3332 last = &t->link, t = t->link) {
3333 if (t == (StgBlockingQueueElement *)tso) {
3334 *last = (StgBlockingQueueElement *)tso->link;
3338 barf("unblockThread (BLACKHOLE): TSO not found");
3341 case BlockedOnException:
3343 StgTSO *target = tso->block_info.tso;
3345 ASSERT(get_itbl(target)->type == TSO);
3347 if (target->what_next == ThreadRelocated) {
3348 target = target->link;
3349 ASSERT(get_itbl(target)->type == TSO);
3352 ASSERT(target->blocked_exceptions != NULL);
3354 last = (StgBlockingQueueElement **)&target->blocked_exceptions;
3355 for (t = (StgBlockingQueueElement *)target->blocked_exceptions;
3357 last = &t->link, t = t->link) {
3358 ASSERT(get_itbl(t)->type == TSO);
3359 if (t == (StgBlockingQueueElement *)tso) {
3360 *last = (StgBlockingQueueElement *)tso->link;
3364 barf("unblockThread (Exception): TSO not found");
3368 case BlockedOnWrite:
3369 #if defined(mingw32_HOST_OS)
3370 case BlockedOnDoProc:
3373 /* take TSO off blocked_queue */
3374 StgBlockingQueueElement *prev = NULL;
3375 for (t = (StgBlockingQueueElement *)blocked_queue_hd; t != END_BQ_QUEUE;
3376 prev = t, t = t->link) {
3377 if (t == (StgBlockingQueueElement *)tso) {
3379 blocked_queue_hd = (StgTSO *)t->link;
3380 if ((StgBlockingQueueElement *)blocked_queue_tl == t) {
3381 blocked_queue_tl = END_TSO_QUEUE;
3384 prev->link = t->link;
3385 if ((StgBlockingQueueElement *)blocked_queue_tl == t) {
3386 blocked_queue_tl = (StgTSO *)prev;
3389 #if defined(mingw32_HOST_OS)
3390 /* (Cooperatively) signal that the worker thread should abort
3393 abandonWorkRequest(tso->block_info.async_result->reqID);
3398 barf("unblockThread (I/O): TSO not found");
3401 case BlockedOnDelay:
3403 /* take TSO off sleeping_queue */
3404 StgBlockingQueueElement *prev = NULL;
3405 for (t = (StgBlockingQueueElement *)sleeping_queue; t != END_BQ_QUEUE;
3406 prev = t, t = t->link) {
3407 if (t == (StgBlockingQueueElement *)tso) {
3409 sleeping_queue = (StgTSO *)t->link;
3411 prev->link = t->link;
3416 barf("unblockThread (delay): TSO not found");
3420 barf("unblockThread");
3424 tso->link = END_TSO_QUEUE;
3425 tso->why_blocked = NotBlocked;
3426 tso->block_info.closure = NULL;
3427 pushOnRunQueue(cap,tso);
3431 unblockThread(Capability *cap, StgTSO *tso)
3435 /* To avoid locking unnecessarily. */
3436 if (tso->why_blocked == NotBlocked) {
3440 switch (tso->why_blocked) {
3443 // Be careful: nothing to do here! We tell the scheduler that the thread
3444 // is runnable and we leave it to the stack-walking code to abort the
3445 // transaction while unwinding the stack. We should perhaps have a debugging
3446 // test to make sure that this really happens and that the 'zombie' transaction
3447 // does not get committed.
3451 ASSERT(get_itbl(tso->block_info.closure)->type == MVAR);
3453 StgTSO *last_tso = END_TSO_QUEUE;
3454 StgMVar *mvar = (StgMVar *)(tso->block_info.closure);
3457 for (t = mvar->head; t != END_TSO_QUEUE;
3458 last = &t->link, last_tso = t, t = t->link) {
3461 if (mvar->tail == tso) {
3462 mvar->tail = last_tso;
3467 barf("unblockThread (MVAR): TSO not found");
3470 case BlockedOnBlackHole:
3472 last = &blackhole_queue;
3473 for (t = blackhole_queue; t != END_TSO_QUEUE;
3474 last = &t->link, t = t->link) {
3480 barf("unblockThread (BLACKHOLE): TSO not found");
3483 case BlockedOnException:
3485 StgTSO *target = tso->block_info.tso;
3487 ASSERT(get_itbl(target)->type == TSO);
3489 while (target->what_next == ThreadRelocated) {
3490 target = target->link;
3491 ASSERT(get_itbl(target)->type == TSO);
3494 ASSERT(target->blocked_exceptions != NULL);
3496 last = &target->blocked_exceptions;
3497 for (t = target->blocked_exceptions; t != END_TSO_QUEUE;
3498 last = &t->link, t = t->link) {
3499 ASSERT(get_itbl(t)->type == TSO);
3505 barf("unblockThread (Exception): TSO not found");
3508 #if !defined(THREADED_RTS)
3510 case BlockedOnWrite:
3511 #if defined(mingw32_HOST_OS)
3512 case BlockedOnDoProc:
3515 StgTSO *prev = NULL;
3516 for (t = blocked_queue_hd; t != END_TSO_QUEUE;
3517 prev = t, t = t->link) {
3520 blocked_queue_hd = t->link;
3521 if (blocked_queue_tl == t) {
3522 blocked_queue_tl = END_TSO_QUEUE;
3525 prev->link = t->link;
3526 if (blocked_queue_tl == t) {
3527 blocked_queue_tl = prev;
3530 #if defined(mingw32_HOST_OS)
3531 /* (Cooperatively) signal that the worker thread should abort
3534 abandonWorkRequest(tso->block_info.async_result->reqID);
3539 barf("unblockThread (I/O): TSO not found");
3542 case BlockedOnDelay:
3544 StgTSO *prev = NULL;
3545 for (t = sleeping_queue; t != END_TSO_QUEUE;
3546 prev = t, t = t->link) {
3549 sleeping_queue = t->link;
3551 prev->link = t->link;
3556 barf("unblockThread (delay): TSO not found");
3561 barf("unblockThread");
3565 tso->link = END_TSO_QUEUE;
3566 tso->why_blocked = NotBlocked;
3567 tso->block_info.closure = NULL;
3568 appendToRunQueue(cap,tso);
3572 /* -----------------------------------------------------------------------------
3575 * Check the blackhole_queue for threads that can be woken up. We do
3576 * this periodically: before every GC, and whenever the run queue is
3579 * An elegant solution might be to just wake up all the blocked
3580 * threads with awakenBlockedQueue occasionally: they'll go back to
3581 * sleep again if the object is still a BLACKHOLE. Unfortunately this
3582 * doesn't give us a way to tell whether we've actually managed to
3583 * wake up any threads, so we would be busy-waiting.
3585 * -------------------------------------------------------------------------- */
3588 checkBlackHoles (Capability *cap)
3591 rtsBool any_woke_up = rtsFalse;
3594 // blackhole_queue is global:
3595 ASSERT_LOCK_HELD(&sched_mutex);
3597 IF_DEBUG(scheduler, sched_belch("checking threads blocked on black holes"));
3599 // ASSUMES: sched_mutex
3600 prev = &blackhole_queue;
3601 t = blackhole_queue;
3602 while (t != END_TSO_QUEUE) {
3603 ASSERT(t->why_blocked == BlockedOnBlackHole);
3604 type = get_itbl(t->block_info.closure)->type;
3605 if (type != BLACKHOLE && type != CAF_BLACKHOLE) {
3606 IF_DEBUG(sanity,checkTSO(t));
3607 t = unblockOne(cap, t);
3608 // urk, the threads migrate to the current capability
3609 // here, but we'd like to keep them on the original one.
3611 any_woke_up = rtsTrue;
3621 /* -----------------------------------------------------------------------------
3624 * The following function implements the magic for raising an
3625 * asynchronous exception in an existing thread.
3627 * We first remove the thread from any queue on which it might be
3628 * blocked. The possible blockages are MVARs and BLACKHOLE_BQs.
3630 * We strip the stack down to the innermost CATCH_FRAME, building
3631 * thunks in the heap for all the active computations, so they can
3632 * be restarted if necessary. When we reach a CATCH_FRAME, we build
3633 * an application of the handler to the exception, and push it on
3634 * the top of the stack.
3636 * How exactly do we save all the active computations? We create an
3637 * AP_STACK for every UpdateFrame on the stack. Entering one of these
3638 * AP_STACKs pushes everything from the corresponding update frame
3639 * upwards onto the stack. (Actually, it pushes everything up to the
3640 * next update frame plus a pointer to the next AP_STACK object.
3641 * Entering the next AP_STACK object pushes more onto the stack until we
3642 * reach the last AP_STACK object - at which point the stack should look
3643 * exactly as it did when we killed the TSO and we can continue
3644 * execution by entering the closure on top of the stack.
3646 * We can also kill a thread entirely - this happens if either (a) the
3647 * exception passed to raiseAsync is NULL, or (b) there's no
3648 * CATCH_FRAME on the stack. In either case, we strip the entire
3649 * stack and replace the thread with a zombie.
3651 * ToDo: in THREADED_RTS mode, this function is only safe if either
3652 * (a) we hold all the Capabilities (eg. in GC, or if there is only
3653 * one Capability), or (b) we own the Capability that the TSO is
3654 * currently blocked on or on the run queue of.
3656 * -------------------------------------------------------------------------- */
3659 raiseAsync(Capability *cap, StgTSO *tso, StgClosure *exception)
3661 raiseAsync_(cap, tso, exception, rtsFalse, NULL);
3665 suspendComputation(Capability *cap, StgTSO *tso, StgPtr stop_here)
3667 raiseAsync_(cap, tso, NULL, rtsFalse, stop_here);
3671 raiseAsync_(Capability *cap, StgTSO *tso, StgClosure *exception,
3672 rtsBool stop_at_atomically, StgPtr stop_here)
3674 StgRetInfoTable *info;
3678 // Thread already dead?
3679 if (tso->what_next == ThreadComplete || tso->what_next == ThreadKilled) {
3684 sched_belch("raising exception in thread %ld.", (long)tso->id));
3686 // Remove it from any blocking queues
3687 unblockThread(cap,tso);
3689 // mark it dirty; we're about to change its stack.
3694 // The stack freezing code assumes there's a closure pointer on
3695 // the top of the stack, so we have to arrange that this is the case...
3697 if (sp[0] == (W_)&stg_enter_info) {
3701 sp[0] = (W_)&stg_dummy_ret_closure;
3705 while (stop_here == NULL || frame < stop_here) {
3707 // 1. Let the top of the stack be the "current closure"
3709 // 2. Walk up the stack until we find either an UPDATE_FRAME or a
3712 // 3. If it's an UPDATE_FRAME, then make an AP_STACK containing the
3713 // current closure applied to the chunk of stack up to (but not
3714 // including) the update frame. This closure becomes the "current
3715 // closure". Go back to step 2.
3717 // 4. If it's a CATCH_FRAME, then leave the exception handler on
3718 // top of the stack applied to the exception.
3720 // 5. If it's a STOP_FRAME, then kill the thread.
3722 // NB: if we pass an ATOMICALLY_FRAME then abort the associated
3725 info = get_ret_itbl((StgClosure *)frame);
3727 switch (info->i.type) {
3734 // First build an AP_STACK consisting of the stack chunk above the
3735 // current update frame, with the top word on the stack as the
3738 words = frame - sp - 1;
3739 ap = (StgAP_STACK *)allocateLocal(cap,AP_STACK_sizeW(words));
3742 ap->fun = (StgClosure *)sp[0];
3744 for(i=0; i < (nat)words; ++i) {
3745 ap->payload[i] = (StgClosure *)*sp++;
3748 SET_HDR(ap,&stg_AP_STACK_info,
3749 ((StgClosure *)frame)->header.prof.ccs /* ToDo */);
3750 TICK_ALLOC_UP_THK(words+1,0);
3753 debugBelch("sched: Updating ");
3754 printPtr((P_)((StgUpdateFrame *)frame)->updatee);
3755 debugBelch(" with ");
3756 printObj((StgClosure *)ap);
3759 // Replace the updatee with an indirection
3761 // Warning: if we're in a loop, more than one update frame on
3762 // the stack may point to the same object. Be careful not to
3763 // overwrite an IND_OLDGEN in this case, because we'll screw
3764 // up the mutable lists. To be on the safe side, don't
3765 // overwrite any kind of indirection at all. See also
3766 // threadSqueezeStack in GC.c, where we have to make a similar
3769 if (!closure_IND(((StgUpdateFrame *)frame)->updatee)) {
3770 // revert the black hole
3771 UPD_IND_NOLOCK(((StgUpdateFrame *)frame)->updatee,
3774 sp += sizeofW(StgUpdateFrame) - 1;
3775 sp[0] = (W_)ap; // push onto stack
3777 continue; //no need to bump frame
3781 // We've stripped the entire stack, the thread is now dead.
3782 tso->what_next = ThreadKilled;
3783 tso->sp = frame + sizeofW(StgStopFrame);
3787 // If we find a CATCH_FRAME, and we've got an exception to raise,
3788 // then build the THUNK raise(exception), and leave it on
3789 // top of the CATCH_FRAME ready to enter.
3793 StgCatchFrame *cf = (StgCatchFrame *)frame;
3797 if (exception == NULL) break;
3799 // we've got an exception to raise, so let's pass it to the
3800 // handler in this frame.
3802 raise = (StgThunk *)allocateLocal(cap,sizeofW(StgThunk)+1);
3803 TICK_ALLOC_SE_THK(1,0);
3804 SET_HDR(raise,&stg_raise_info,cf->header.prof.ccs);
3805 raise->payload[0] = exception;
3807 // throw away the stack from Sp up to the CATCH_FRAME.
3811 /* Ensure that async excpetions are blocked now, so we don't get
3812 * a surprise exception before we get around to executing the
3815 if (tso->blocked_exceptions == NULL) {
3816 tso->blocked_exceptions = END_TSO_QUEUE;
3819 /* Put the newly-built THUNK on top of the stack, ready to execute
3820 * when the thread restarts.
3823 sp[-1] = (W_)&stg_enter_info;
3825 tso->what_next = ThreadRunGHC;
3826 IF_DEBUG(sanity, checkTSO(tso));
3830 case ATOMICALLY_FRAME:
3831 if (stop_at_atomically) {
3832 ASSERT(stmGetEnclosingTRec(tso->trec) == NO_TREC);
3833 stmCondemnTransaction(cap, tso -> trec);
3837 // R1 is not a register: the return convention for IO in
3838 // this case puts the return value on the stack, so we
3839 // need to set up the stack to return to the atomically
3840 // frame properly...
3841 tso->sp = frame - 2;
3842 tso->sp[1] = (StgWord) &stg_NO_FINALIZER_closure; // why not?
3843 tso->sp[0] = (StgWord) &stg_ut_1_0_unreg_info;
3845 tso->what_next = ThreadRunGHC;
3848 // Not stop_at_atomically... fall through and abort the
3851 case CATCH_RETRY_FRAME:
3852 // IF we find an ATOMICALLY_FRAME then we abort the
3853 // current transaction and propagate the exception. In
3854 // this case (unlike ordinary exceptions) we do not care
3855 // whether the transaction is valid or not because its
3856 // possible validity cannot have caused the exception
3857 // and will not be visible after the abort.
3859 debugBelch("Found atomically block delivering async exception\n"));
3860 StgTRecHeader *trec = tso -> trec;
3861 StgTRecHeader *outer = stmGetEnclosingTRec(trec);
3862 stmAbortTransaction(cap, trec);
3863 tso -> trec = outer;
3870 // move on to the next stack frame
3871 frame += stack_frame_sizeW((StgClosure *)frame);
3874 // if we got here, then we stopped at stop_here
3875 ASSERT(stop_here != NULL);
3878 /* -----------------------------------------------------------------------------
3881 This is used for interruption (^C) and forking, and corresponds to
3882 raising an exception but without letting the thread catch the
3884 -------------------------------------------------------------------------- */
3887 deleteThread (Capability *cap, StgTSO *tso)
3889 if (tso->why_blocked != BlockedOnCCall &&
3890 tso->why_blocked != BlockedOnCCall_NoUnblockExc) {
3891 raiseAsync(cap,tso,NULL);
3895 #ifdef FORKPROCESS_PRIMOP_SUPPORTED
3897 deleteThreadImmediately(Capability *cap, StgTSO *tso)
3898 { // for forkProcess only:
3899 // delete thread without giving it a chance to catch the KillThread exception
3901 if (tso->what_next == ThreadComplete || tso->what_next == ThreadKilled) {
3905 if (tso->why_blocked != BlockedOnCCall &&
3906 tso->why_blocked != BlockedOnCCall_NoUnblockExc) {
3907 unblockThread(cap,tso);
3910 tso->what_next = ThreadKilled;
3914 /* -----------------------------------------------------------------------------
3915 raiseExceptionHelper
3917 This function is called by the raise# primitve, just so that we can
3918 move some of the tricky bits of raising an exception from C-- into
3919 C. Who knows, it might be a useful re-useable thing here too.
3920 -------------------------------------------------------------------------- */
3923 raiseExceptionHelper (StgRegTable *reg, StgTSO *tso, StgClosure *exception)
3925 Capability *cap = regTableToCapability(reg);
3926 StgThunk *raise_closure = NULL;
3928 StgRetInfoTable *info;
3930 // This closure represents the expression 'raise# E' where E
3931 // is the exception raise. It is used to overwrite all the
3932 // thunks which are currently under evaluataion.
3935 // OLD COMMENT (we don't have MIN_UPD_SIZE now):
3936 // LDV profiling: stg_raise_info has THUNK as its closure
3937 // type. Since a THUNK takes at least MIN_UPD_SIZE words in its
3938 // payload, MIN_UPD_SIZE is more approprate than 1. It seems that
3939 // 1 does not cause any problem unless profiling is performed.
3940 // However, when LDV profiling goes on, we need to linearly scan
3941 // small object pool, where raise_closure is stored, so we should
3942 // use MIN_UPD_SIZE.
3944 // raise_closure = (StgClosure *)RET_STGCALL1(P_,allocate,
3945 // sizeofW(StgClosure)+1);
3949 // Walk up the stack, looking for the catch frame. On the way,
3950 // we update any closures pointed to from update frames with the
3951 // raise closure that we just built.
3955 info = get_ret_itbl((StgClosure *)p);
3956 next = p + stack_frame_sizeW((StgClosure *)p);
3957 switch (info->i.type) {
3960 // Only create raise_closure if we need to.
3961 if (raise_closure == NULL) {
3963 (StgThunk *)allocateLocal(cap,sizeofW(StgThunk)+1);
3964 SET_HDR(raise_closure, &stg_raise_info, CCCS);
3965 raise_closure->payload[0] = exception;
3967 UPD_IND(((StgUpdateFrame *)p)->updatee,(StgClosure *)raise_closure);
3971 case ATOMICALLY_FRAME:
3972 IF_DEBUG(stm, debugBelch("Found ATOMICALLY_FRAME at %p\n", p));
3974 return ATOMICALLY_FRAME;
3980 case CATCH_STM_FRAME:
3981 IF_DEBUG(stm, debugBelch("Found CATCH_STM_FRAME at %p\n", p));
3983 return CATCH_STM_FRAME;
3989 case CATCH_RETRY_FRAME:
3998 /* -----------------------------------------------------------------------------
3999 findRetryFrameHelper
4001 This function is called by the retry# primitive. It traverses the stack
4002 leaving tso->sp referring to the frame which should handle the retry.
4004 This should either be a CATCH_RETRY_FRAME (if the retry# is within an orElse#)
4005 or should be a ATOMICALLY_FRAME (if the retry# reaches the top level).
4007 We skip CATCH_STM_FRAMEs because retries are not considered to be exceptions,
4008 despite the similar implementation.
4010 We should not expect to see CATCH_FRAME or STOP_FRAME because those should
4011 not be created within memory transactions.
4012 -------------------------------------------------------------------------- */
4015 findRetryFrameHelper (StgTSO *tso)
4018 StgRetInfoTable *info;
4022 info = get_ret_itbl((StgClosure *)p);
4023 next = p + stack_frame_sizeW((StgClosure *)p);
4024 switch (info->i.type) {
4026 case ATOMICALLY_FRAME:
4027 IF_DEBUG(stm, debugBelch("Found ATOMICALLY_FRAME at %p during retrry\n", p));
4029 return ATOMICALLY_FRAME;
4031 case CATCH_RETRY_FRAME:
4032 IF_DEBUG(stm, debugBelch("Found CATCH_RETRY_FRAME at %p during retrry\n", p));
4034 return CATCH_RETRY_FRAME;
4036 case CATCH_STM_FRAME:
4038 ASSERT(info->i.type != CATCH_FRAME);
4039 ASSERT(info->i.type != STOP_FRAME);
4046 /* -----------------------------------------------------------------------------
4047 resurrectThreads is called after garbage collection on the list of
4048 threads found to be garbage. Each of these threads will be woken
4049 up and sent a signal: BlockedOnDeadMVar if the thread was blocked
4050 on an MVar, or NonTermination if the thread was blocked on a Black
4053 Locks: assumes we hold *all* the capabilities.
4054 -------------------------------------------------------------------------- */
4057 resurrectThreads (StgTSO *threads)
4062 for (tso = threads; tso != END_TSO_QUEUE; tso = next) {
4063 next = tso->global_link;
4064 tso->global_link = all_threads;
4066 IF_DEBUG(scheduler, sched_belch("resurrecting thread %d", tso->id));
4068 // Wake up the thread on the Capability it was last on for a
4069 // bound thread, or last_free_capability otherwise.
4071 cap = tso->bound->cap;
4073 cap = last_free_capability;
4076 switch (tso->why_blocked) {
4078 case BlockedOnException:
4079 /* Called by GC - sched_mutex lock is currently held. */
4080 raiseAsync(cap, tso,(StgClosure *)BlockedOnDeadMVar_closure);
4082 case BlockedOnBlackHole:
4083 raiseAsync(cap, tso,(StgClosure *)NonTermination_closure);
4086 raiseAsync(cap, tso,(StgClosure *)BlockedIndefinitely_closure);
4089 /* This might happen if the thread was blocked on a black hole
4090 * belonging to a thread that we've just woken up (raiseAsync
4091 * can wake up threads, remember...).
4095 barf("resurrectThreads: thread blocked in a strange way");
4100 /* ----------------------------------------------------------------------------
4101 * Debugging: why is a thread blocked
4102 * [Also provides useful information when debugging threaded programs
4103 * at the Haskell source code level, so enable outside of DEBUG. --sof 7/02]
4104 ------------------------------------------------------------------------- */
4108 printThreadBlockage(StgTSO *tso)
4110 switch (tso->why_blocked) {
4112 debugBelch("is blocked on read from fd %d", (int)(tso->block_info.fd));
4114 case BlockedOnWrite:
4115 debugBelch("is blocked on write to fd %d", (int)(tso->block_info.fd));
4117 #if defined(mingw32_HOST_OS)
4118 case BlockedOnDoProc:
4119 debugBelch("is blocked on proc (request: %ld)", tso->block_info.async_result->reqID);
4122 case BlockedOnDelay:
4123 debugBelch("is blocked until %ld", (long)(tso->block_info.target));
4126 debugBelch("is blocked on an MVar @ %p", tso->block_info.closure);
4128 case BlockedOnException:
4129 debugBelch("is blocked on delivering an exception to thread %d",
4130 tso->block_info.tso->id);
4132 case BlockedOnBlackHole:
4133 debugBelch("is blocked on a black hole");
4136 debugBelch("is not blocked");
4138 #if defined(PARALLEL_HASKELL)
4140 debugBelch("is blocked on global address; local FM_BQ is %p (%s)",
4141 tso->block_info.closure, info_type(tso->block_info.closure));
4143 case BlockedOnGA_NoSend:
4144 debugBelch("is blocked on global address (no send); local FM_BQ is %p (%s)",
4145 tso->block_info.closure, info_type(tso->block_info.closure));
4148 case BlockedOnCCall:
4149 debugBelch("is blocked on an external call");
4151 case BlockedOnCCall_NoUnblockExc:
4152 debugBelch("is blocked on an external call (exceptions were already blocked)");
4155 debugBelch("is blocked on an STM operation");
4158 barf("printThreadBlockage: strange tso->why_blocked: %d for TSO %d (%d)",
4159 tso->why_blocked, tso->id, tso);
4164 printThreadStatus(StgTSO *t)
4166 debugBelch("\tthread %4d @ %p ", t->id, (void *)t);
4168 void *label = lookupThreadLabel(t->id);
4169 if (label) debugBelch("[\"%s\"] ",(char *)label);
4171 if (t->what_next == ThreadRelocated) {
4172 debugBelch("has been relocated...\n");
4174 switch (t->what_next) {
4176 debugBelch("has been killed");
4178 case ThreadComplete:
4179 debugBelch("has completed");
4182 printThreadBlockage(t);
4189 printAllThreads(void)
4196 char time_string[TIME_STR_LEN], node_str[NODE_STR_LEN];
4197 ullong_format_string(TIME_ON_PROC(CurrentProc),
4198 time_string, rtsFalse/*no commas!*/);
4200 debugBelch("all threads at [%s]:\n", time_string);
4201 # elif defined(PARALLEL_HASKELL)
4202 char time_string[TIME_STR_LEN], node_str[NODE_STR_LEN];
4203 ullong_format_string(CURRENT_TIME,
4204 time_string, rtsFalse/*no commas!*/);
4206 debugBelch("all threads at [%s]:\n", time_string);
4208 debugBelch("all threads:\n");
4211 for (i = 0; i < n_capabilities; i++) {
4212 cap = &capabilities[i];
4213 debugBelch("threads on capability %d:\n", cap->no);
4214 for (t = cap->run_queue_hd; t != END_TSO_QUEUE; t = t->link) {
4215 printThreadStatus(t);
4219 debugBelch("other threads:\n");
4220 for (t = all_threads; t != END_TSO_QUEUE; t = next) {
4221 if (t->why_blocked != NotBlocked) {
4222 printThreadStatus(t);
4224 if (t->what_next == ThreadRelocated) {
4227 next = t->global_link;
4234 printThreadQueue(StgTSO *t)
4237 for (; t != END_TSO_QUEUE; t = t->link) {
4238 printThreadStatus(t);
4241 debugBelch("%d threads on queue\n", i);
4245 Print a whole blocking queue attached to node (debugging only).
4247 # if defined(PARALLEL_HASKELL)
4249 print_bq (StgClosure *node)
4251 StgBlockingQueueElement *bqe;
4255 debugBelch("## BQ of closure %p (%s): ",
4256 node, info_type(node));
4258 /* should cover all closures that may have a blocking queue */
4259 ASSERT(get_itbl(node)->type == BLACKHOLE_BQ ||
4260 get_itbl(node)->type == FETCH_ME_BQ ||
4261 get_itbl(node)->type == RBH ||
4262 get_itbl(node)->type == MVAR);
4264 ASSERT(node!=(StgClosure*)NULL); // sanity check
4266 print_bqe(((StgBlockingQueue*)node)->blocking_queue);
4270 Print a whole blocking queue starting with the element bqe.
4273 print_bqe (StgBlockingQueueElement *bqe)
4278 NB: In a parallel setup a BQ of an RBH must end with an RBH_Save closure;
4280 for (end = (bqe==END_BQ_QUEUE);
4281 !end; // iterate until bqe points to a CONSTR
4282 end = (get_itbl(bqe)->type == CONSTR) || (bqe->link==END_BQ_QUEUE),
4283 bqe = end ? END_BQ_QUEUE : bqe->link) {
4284 ASSERT(bqe != END_BQ_QUEUE); // sanity check
4285 ASSERT(bqe != (StgBlockingQueueElement *)NULL); // sanity check
4286 /* types of closures that may appear in a blocking queue */
4287 ASSERT(get_itbl(bqe)->type == TSO ||
4288 get_itbl(bqe)->type == BLOCKED_FETCH ||
4289 get_itbl(bqe)->type == CONSTR);
4290 /* only BQs of an RBH end with an RBH_Save closure */
4291 //ASSERT(get_itbl(bqe)->type != CONSTR || get_itbl(node)->type == RBH);
4293 switch (get_itbl(bqe)->type) {
4295 debugBelch(" TSO %u (%x),",
4296 ((StgTSO *)bqe)->id, ((StgTSO *)bqe));
4299 debugBelch(" BF (node=%p, ga=((%x, %d, %x)),",
4300 ((StgBlockedFetch *)bqe)->node,
4301 ((StgBlockedFetch *)bqe)->ga.payload.gc.gtid,
4302 ((StgBlockedFetch *)bqe)->ga.payload.gc.slot,
4303 ((StgBlockedFetch *)bqe)->ga.weight);
4306 debugBelch(" %s (IP %p),",
4307 (get_itbl(bqe) == &stg_RBH_Save_0_info ? "RBH_Save_0" :
4308 get_itbl(bqe) == &stg_RBH_Save_1_info ? "RBH_Save_1" :
4309 get_itbl(bqe) == &stg_RBH_Save_2_info ? "RBH_Save_2" :
4310 "RBH_Save_?"), get_itbl(bqe));
4313 barf("Unexpected closure type %s in blocking queue", // of %p (%s)",
4314 info_type((StgClosure *)bqe)); // , node, info_type(node));
4320 # elif defined(GRAN)
4322 print_bq (StgClosure *node)
4324 StgBlockingQueueElement *bqe;
4325 PEs node_loc, tso_loc;
4328 /* should cover all closures that may have a blocking queue */
4329 ASSERT(get_itbl(node)->type == BLACKHOLE_BQ ||
4330 get_itbl(node)->type == FETCH_ME_BQ ||
4331 get_itbl(node)->type == RBH);
4333 ASSERT(node!=(StgClosure*)NULL); // sanity check
4334 node_loc = where_is(node);
4336 debugBelch("## BQ of closure %p (%s) on [PE %d]: ",
4337 node, info_type(node), node_loc);
4340 NB: In a parallel setup a BQ of an RBH must end with an RBH_Save closure;
4342 for (bqe = ((StgBlockingQueue*)node)->blocking_queue, end = (bqe==END_BQ_QUEUE);
4343 !end; // iterate until bqe points to a CONSTR
4344 end = (get_itbl(bqe)->type == CONSTR) || (bqe->link==END_BQ_QUEUE), bqe = end ? END_BQ_QUEUE : bqe->link) {
4345 ASSERT(bqe != END_BQ_QUEUE); // sanity check
4346 ASSERT(bqe != (StgBlockingQueueElement *)NULL); // sanity check
4347 /* types of closures that may appear in a blocking queue */
4348 ASSERT(get_itbl(bqe)->type == TSO ||
4349 get_itbl(bqe)->type == CONSTR);
4350 /* only BQs of an RBH end with an RBH_Save closure */
4351 ASSERT(get_itbl(bqe)->type != CONSTR || get_itbl(node)->type == RBH);
4353 tso_loc = where_is((StgClosure *)bqe);
4354 switch (get_itbl(bqe)->type) {
4356 debugBelch(" TSO %d (%p) on [PE %d],",
4357 ((StgTSO *)bqe)->id, (StgTSO *)bqe, tso_loc);
4360 debugBelch(" %s (IP %p),",
4361 (get_itbl(bqe) == &stg_RBH_Save_0_info ? "RBH_Save_0" :
4362 get_itbl(bqe) == &stg_RBH_Save_1_info ? "RBH_Save_1" :
4363 get_itbl(bqe) == &stg_RBH_Save_2_info ? "RBH_Save_2" :
4364 "RBH_Save_?"), get_itbl(bqe));
4367 barf("Unexpected closure type %s in blocking queue of %p (%s)",
4368 info_type((StgClosure *)bqe), node, info_type(node));
4376 #if defined(PARALLEL_HASKELL)
4383 for (i=0, tso=run_queue_hd;
4384 tso != END_TSO_QUEUE;
4385 i++, tso=tso->link) {
4394 sched_belch(char *s, ...)
4399 debugBelch("sched (task %p): ", (void *)(unsigned long)(unsigned int)osThreadId());
4400 #elif defined(PARALLEL_HASKELL)
4403 debugBelch("sched: ");