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 sched_state = SCHED_RUNNING;
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 Capability *scheduleDoGC(Capability *cap, Task *task,
232 void (*get_roots)(evac_fn));
234 static void unblockThread(Capability *cap, StgTSO *tso);
235 static rtsBool checkBlackHoles(Capability *cap);
236 static void AllRoots(evac_fn evac);
238 static StgTSO *threadStackOverflow(Capability *cap, StgTSO *tso);
240 static void raiseAsync_(Capability *cap, StgTSO *tso, StgClosure *exception,
241 rtsBool stop_at_atomically, StgPtr stop_here);
243 static void deleteThread (Capability *cap, StgTSO *tso);
244 static void deleteAllThreads (Capability *cap);
247 static void printThreadBlockage(StgTSO *tso);
248 static void printThreadStatus(StgTSO *tso);
249 void printThreadQueue(StgTSO *tso);
252 #if defined(PARALLEL_HASKELL)
253 StgTSO * createSparkThread(rtsSpark spark);
254 StgTSO * activateSpark (rtsSpark spark);
258 static char *whatNext_strs[] = {
268 /* -----------------------------------------------------------------------------
269 * Putting a thread on the run queue: different scheduling policies
270 * -------------------------------------------------------------------------- */
273 addToRunQueue( Capability *cap, StgTSO *t )
275 #if defined(PARALLEL_HASKELL)
276 if (RtsFlags.ParFlags.doFairScheduling) {
277 // this does round-robin scheduling; good for concurrency
278 appendToRunQueue(cap,t);
280 // this does unfair scheduling; good for parallelism
281 pushOnRunQueue(cap,t);
284 // this does round-robin scheduling; good for concurrency
285 appendToRunQueue(cap,t);
289 /* ---------------------------------------------------------------------------
290 Main scheduling loop.
292 We use round-robin scheduling, each thread returning to the
293 scheduler loop when one of these conditions is detected:
296 * timer expires (thread yields)
302 In a GranSim setup this loop iterates over the global event queue.
303 This revolves around the global event queue, which determines what
304 to do next. Therefore, it's more complicated than either the
305 concurrent or the parallel (GUM) setup.
308 GUM iterates over incoming messages.
309 It starts with nothing to do (thus CurrentTSO == END_TSO_QUEUE),
310 and sends out a fish whenever it has nothing to do; in-between
311 doing the actual reductions (shared code below) it processes the
312 incoming messages and deals with delayed operations
313 (see PendingFetches).
314 This is not the ugliest code you could imagine, but it's bloody close.
316 ------------------------------------------------------------------------ */
319 schedule (Capability *initialCapability, Task *task)
323 StgThreadReturnCode ret;
326 #elif defined(PARALLEL_HASKELL)
329 rtsBool receivedFinish = rtsFalse;
331 nat tp_size, sp_size; // stats only
336 #if defined(THREADED_RTS)
337 rtsBool first = rtsTrue;
340 cap = initialCapability;
342 // Pre-condition: this task owns initialCapability.
343 // The sched_mutex is *NOT* held
344 // NB. on return, we still hold a capability.
347 sched_belch("### NEW SCHEDULER LOOP (task: %p, cap: %p)",
348 task, initialCapability);
353 // -----------------------------------------------------------
354 // Scheduler loop starts here:
356 #if defined(PARALLEL_HASKELL)
357 #define TERMINATION_CONDITION (!receivedFinish)
359 #define TERMINATION_CONDITION ((event = get_next_event()) != (rtsEvent*)NULL)
361 #define TERMINATION_CONDITION rtsTrue
364 while (TERMINATION_CONDITION) {
367 /* Choose the processor with the next event */
368 CurrentProc = event->proc;
369 CurrentTSO = event->tso;
372 #if defined(THREADED_RTS)
374 // don't yield the first time, we want a chance to run this
375 // thread for a bit, even if there are others banging at the
378 ASSERT_FULL_CAPABILITY_INVARIANTS(cap,task);
380 // Yield the capability to higher-priority tasks if necessary.
381 yieldCapability(&cap, task);
385 #if defined(THREADED_RTS)
386 schedulePushWork(cap,task);
389 // Check whether we have re-entered the RTS from Haskell without
390 // going via suspendThread()/resumeThread (i.e. a 'safe' foreign
392 if (cap->in_haskell) {
393 errorBelch("schedule: re-entered unsafely.\n"
394 " Perhaps a 'foreign import unsafe' should be 'safe'?");
395 stg_exit(EXIT_FAILURE);
398 // The interruption / shutdown sequence.
400 // In order to cleanly shut down the runtime, we want to:
401 // * make sure that all main threads return to their callers
402 // with the state 'Interrupted'.
403 // * clean up all OS threads assocated with the runtime
404 // * free all memory etc.
406 // So the sequence for ^C goes like this:
408 // * ^C handler sets sched_state := SCHED_INTERRUPTING and
409 // arranges for some Capability to wake up
411 // * all threads in the system are halted, and the zombies are
412 // placed on the run queue for cleaning up. We acquire all
413 // the capabilities in order to delete the threads, this is
414 // done by scheduleDoGC() for convenience (because GC already
415 // needs to acquire all the capabilities). We can't kill
416 // threads involved in foreign calls.
418 // * sched_state := SCHED_INTERRUPTED
420 // * somebody calls shutdownHaskell(), which calls exitScheduler()
422 // * sched_state := SCHED_SHUTTING_DOWN
424 // * all workers exit when the run queue on their capability
425 // drains. All main threads will also exit when their TSO
426 // reaches the head of the run queue and they can return.
428 // * eventually all Capabilities will shut down, and the RTS can
431 // * We might be left with threads blocked in foreign calls,
432 // we should really attempt to kill these somehow (TODO);
434 switch (sched_state) {
437 case SCHED_INTERRUPTING:
438 IF_DEBUG(scheduler, sched_belch("SCHED_INTERRUPTING"));
439 #if defined(THREADED_RTS)
440 discardSparksCap(cap);
442 /* scheduleDoGC() deletes all the threads */
443 cap = scheduleDoGC(cap,task,rtsFalse,GetRoots);
445 case SCHED_INTERRUPTED:
446 IF_DEBUG(scheduler, sched_belch("SCHED_INTERRUPTED"));
448 case SCHED_SHUTTING_DOWN:
449 IF_DEBUG(scheduler, sched_belch("SCHED_SHUTTING_DOWN"));
450 // If we are a worker, just exit. If we're a bound thread
451 // then we will exit below when we've removed our TSO from
453 if (task->tso == NULL && emptyRunQueue(cap)) {
458 barf("sched_state: %d", sched_state);
461 #if defined(THREADED_RTS)
462 // If the run queue is empty, take a spark and turn it into a thread.
464 if (emptyRunQueue(cap)) {
466 spark = findSpark(cap);
469 sched_belch("turning spark of closure %p into a thread",
470 (StgClosure *)spark));
471 createSparkThread(cap,spark);
475 #endif // THREADED_RTS
477 scheduleStartSignalHandlers(cap);
479 // Only check the black holes here if we've nothing else to do.
480 // During normal execution, the black hole list only gets checked
481 // at GC time, to avoid repeatedly traversing this possibly long
482 // list each time around the scheduler.
483 if (emptyRunQueue(cap)) { scheduleCheckBlackHoles(cap); }
485 scheduleCheckBlockedThreads(cap);
487 scheduleDetectDeadlock(cap,task);
488 #if defined(THREADED_RTS)
489 cap = task->cap; // reload cap, it might have changed
492 // Normally, the only way we can get here with no threads to
493 // run is if a keyboard interrupt received during
494 // scheduleCheckBlockedThreads() or scheduleDetectDeadlock().
495 // Additionally, it is not fatal for the
496 // threaded RTS to reach here with no threads to run.
498 // win32: might be here due to awaitEvent() being abandoned
499 // as a result of a console event having been delivered.
500 if ( emptyRunQueue(cap) ) {
501 #if !defined(THREADED_RTS) && !defined(mingw32_HOST_OS)
502 ASSERT(sched_state >= SCHED_INTERRUPTING);
504 continue; // nothing to do
507 #if defined(PARALLEL_HASKELL)
508 scheduleSendPendingMessages();
509 if (emptyRunQueue(cap) && scheduleActivateSpark())
513 ASSERT(next_fish_to_send_at==0); // i.e. no delayed fishes left!
516 /* If we still have no work we need to send a FISH to get a spark
518 if (emptyRunQueue(cap)) {
519 if (!scheduleGetRemoteWork(&receivedFinish)) continue;
520 ASSERT(rtsFalse); // should not happen at the moment
522 // from here: non-empty run queue.
523 // TODO: merge above case with this, only one call processMessages() !
524 if (PacketsWaiting()) { /* process incoming messages, if
525 any pending... only in else
526 because getRemoteWork waits for
528 receivedFinish = processMessages();
533 scheduleProcessEvent(event);
537 // Get a thread to run
539 t = popRunQueue(cap);
541 #if defined(GRAN) || defined(PAR)
542 scheduleGranParReport(); // some kind of debuging output
544 // Sanity check the thread we're about to run. This can be
545 // expensive if there is lots of thread switching going on...
546 IF_DEBUG(sanity,checkTSO(t));
549 #if defined(THREADED_RTS)
550 // Check whether we can run this thread in the current task.
551 // If not, we have to pass our capability to the right task.
553 Task *bound = t->bound;
558 sched_belch("### Running thread %d in bound thread",
560 // yes, the Haskell thread is bound to the current native thread
563 sched_belch("### thread %d bound to another OS thread",
565 // no, bound to a different Haskell thread: pass to that thread
566 pushOnRunQueue(cap,t);
570 // The thread we want to run is unbound.
573 sched_belch("### this OS thread cannot run thread %d", t->id));
574 // no, the current native thread is bound to a different
575 // Haskell thread, so pass it to any worker thread
576 pushOnRunQueue(cap,t);
583 cap->r.rCurrentTSO = t;
585 /* context switches are initiated by the timer signal, unless
586 * the user specified "context switch as often as possible", with
589 if (RtsFlags.ConcFlags.ctxtSwitchTicks == 0
590 && !emptyThreadQueues(cap)) {
596 IF_DEBUG(scheduler, sched_belch("-->> running thread %ld %s ...",
597 (long)t->id, whatNext_strs[t->what_next]));
599 #if defined(PROFILING)
600 startHeapProfTimer();
603 // ----------------------------------------------------------------------
604 // Run the current thread
606 ASSERT_FULL_CAPABILITY_INVARIANTS(cap,task);
608 prev_what_next = t->what_next;
610 errno = t->saved_errno;
611 cap->in_haskell = rtsTrue;
615 recent_activity = ACTIVITY_YES;
617 switch (prev_what_next) {
621 /* Thread already finished, return to scheduler. */
622 ret = ThreadFinished;
628 r = StgRun((StgFunPtr) stg_returnToStackTop, &cap->r);
629 cap = regTableToCapability(r);
634 case ThreadInterpret:
635 cap = interpretBCO(cap);
640 barf("schedule: invalid what_next field");
643 cap->in_haskell = rtsFalse;
645 // The TSO might have moved, eg. if it re-entered the RTS and a GC
646 // happened. So find the new location:
647 t = cap->r.rCurrentTSO;
649 // We have run some Haskell code: there might be blackhole-blocked
650 // threads to wake up now.
651 // Lock-free test here should be ok, we're just setting a flag.
652 if ( blackhole_queue != END_TSO_QUEUE ) {
653 blackholes_need_checking = rtsTrue;
656 // And save the current errno in this thread.
657 // XXX: possibly bogus for SMP because this thread might already
658 // be running again, see code below.
659 t->saved_errno = errno;
661 #if defined(THREADED_RTS)
662 // If ret is ThreadBlocked, and this Task is bound to the TSO that
663 // blocked, we are in limbo - the TSO is now owned by whatever it
664 // is blocked on, and may in fact already have been woken up,
665 // perhaps even on a different Capability. It may be the case
666 // that task->cap != cap. We better yield this Capability
667 // immediately and return to normaility.
668 if (ret == ThreadBlocked) {
670 sched_belch("--<< thread %d (%s) stopped: blocked\n",
671 t->id, whatNext_strs[t->what_next]));
676 ASSERT_FULL_CAPABILITY_INVARIANTS(cap,task);
678 // ----------------------------------------------------------------------
680 // Costs for the scheduler are assigned to CCS_SYSTEM
681 #if defined(PROFILING)
686 #if defined(THREADED_RTS)
687 IF_DEBUG(scheduler,debugBelch("sched (task %p): ", (void *)(unsigned long)(unsigned int)osThreadId()););
688 #elif !defined(GRAN) && !defined(PARALLEL_HASKELL)
689 IF_DEBUG(scheduler,debugBelch("sched: "););
692 schedulePostRunThread();
694 ready_to_gc = rtsFalse;
698 ready_to_gc = scheduleHandleHeapOverflow(cap,t);
702 scheduleHandleStackOverflow(cap,task,t);
706 if (scheduleHandleYield(cap, t, prev_what_next)) {
707 // shortcut for switching between compiler/interpreter:
713 scheduleHandleThreadBlocked(t);
717 if (scheduleHandleThreadFinished(cap, task, t)) return cap;
718 ASSERT_FULL_CAPABILITY_INVARIANTS(cap,task);
722 barf("schedule: invalid thread return code %d", (int)ret);
725 if (scheduleDoHeapProfile(ready_to_gc)) { ready_to_gc = rtsFalse; }
727 cap = scheduleDoGC(cap,task,rtsFalse,GetRoots);
729 } /* end of while() */
731 IF_PAR_DEBUG(verbose,
732 debugBelch("== Leaving schedule() after having received Finish\n"));
735 /* ----------------------------------------------------------------------------
736 * Setting up the scheduler loop
737 * ------------------------------------------------------------------------- */
740 schedulePreLoop(void)
743 /* set up first event to get things going */
744 /* ToDo: assign costs for system setup and init MainTSO ! */
745 new_event(CurrentProc, CurrentProc, CurrentTime[CurrentProc],
747 CurrentTSO, (StgClosure*)NULL, (rtsSpark*)NULL);
750 debugBelch("GRAN: Init CurrentTSO (in schedule) = %p\n",
752 G_TSO(CurrentTSO, 5));
754 if (RtsFlags.GranFlags.Light) {
755 /* Save current time; GranSim Light only */
756 CurrentTSO->gran.clock = CurrentTime[CurrentProc];
761 /* -----------------------------------------------------------------------------
764 * Push work to other Capabilities if we have some.
765 * -------------------------------------------------------------------------- */
767 #if defined(THREADED_RTS)
769 schedulePushWork(Capability *cap USED_IF_THREADS,
770 Task *task USED_IF_THREADS)
772 Capability *free_caps[n_capabilities], *cap0;
775 // Check whether we have more threads on our run queue, or sparks
776 // in our pool, that we could hand to another Capability.
777 if ((emptyRunQueue(cap) || cap->run_queue_hd->link == END_TSO_QUEUE)
778 && sparkPoolSizeCap(cap) < 2) {
782 // First grab as many free Capabilities as we can.
783 for (i=0, n_free_caps=0; i < n_capabilities; i++) {
784 cap0 = &capabilities[i];
785 if (cap != cap0 && tryGrabCapability(cap0,task)) {
786 if (!emptyRunQueue(cap0) || cap->returning_tasks_hd != NULL) {
787 // it already has some work, we just grabbed it at
788 // the wrong moment. Or maybe it's deadlocked!
789 releaseCapability(cap0);
791 free_caps[n_free_caps++] = cap0;
796 // we now have n_free_caps free capabilities stashed in
797 // free_caps[]. Share our run queue equally with them. This is
798 // probably the simplest thing we could do; improvements we might
799 // want to do include:
801 // - giving high priority to moving relatively new threads, on
802 // the gournds that they haven't had time to build up a
803 // working set in the cache on this CPU/Capability.
805 // - giving low priority to moving long-lived threads
807 if (n_free_caps > 0) {
808 StgTSO *prev, *t, *next;
809 rtsBool pushed_to_all;
811 IF_DEBUG(scheduler, sched_belch("excess threads on run queue and %d free capabilities, sharing...", n_free_caps));
814 pushed_to_all = rtsFalse;
816 if (cap->run_queue_hd != END_TSO_QUEUE) {
817 prev = cap->run_queue_hd;
819 prev->link = END_TSO_QUEUE;
820 for (; t != END_TSO_QUEUE; t = next) {
822 t->link = END_TSO_QUEUE;
823 if (t->what_next == ThreadRelocated
824 || t->bound == task) { // don't move my bound thread
827 } else if (i == n_free_caps) {
828 pushed_to_all = rtsTrue;
834 IF_DEBUG(scheduler, sched_belch("pushing thread %d to capability %d", t->id, free_caps[i]->no));
835 appendToRunQueue(free_caps[i],t);
836 if (t->bound) { t->bound->cap = free_caps[i]; }
840 cap->run_queue_tl = prev;
843 // If there are some free capabilities that we didn't push any
844 // threads to, then try to push a spark to each one.
845 if (!pushed_to_all) {
847 // i is the next free capability to push to
848 for (; i < n_free_caps; i++) {
849 if (emptySparkPoolCap(free_caps[i])) {
850 spark = findSpark(cap);
852 IF_DEBUG(scheduler, sched_belch("pushing spark %p to capability %d", spark, free_caps[i]->no));
853 newSpark(&(free_caps[i]->r), spark);
859 // release the capabilities
860 for (i = 0; i < n_free_caps; i++) {
861 task->cap = free_caps[i];
862 releaseCapability(free_caps[i]);
865 task->cap = cap; // reset to point to our Capability.
869 /* ----------------------------------------------------------------------------
870 * Start any pending signal handlers
871 * ------------------------------------------------------------------------- */
873 #if defined(RTS_USER_SIGNALS) && (!defined(THREADED_RTS) || defined(mingw32_HOST_OS))
875 scheduleStartSignalHandlers(Capability *cap)
877 if (signals_pending()) { // safe outside the lock
878 startSignalHandlers(cap);
883 scheduleStartSignalHandlers(Capability *cap STG_UNUSED)
888 /* ----------------------------------------------------------------------------
889 * Check for blocked threads that can be woken up.
890 * ------------------------------------------------------------------------- */
893 scheduleCheckBlockedThreads(Capability *cap USED_IF_NOT_THREADS)
895 #if !defined(THREADED_RTS)
897 // Check whether any waiting threads need to be woken up. If the
898 // run queue is empty, and there are no other tasks running, we
899 // can wait indefinitely for something to happen.
901 if ( !emptyQueue(blocked_queue_hd) || !emptyQueue(sleeping_queue) )
903 awaitEvent( emptyRunQueue(cap) && !blackholes_need_checking );
909 /* ----------------------------------------------------------------------------
910 * Check for threads blocked on BLACKHOLEs that can be woken up
911 * ------------------------------------------------------------------------- */
913 scheduleCheckBlackHoles (Capability *cap)
915 if ( blackholes_need_checking ) // check without the lock first
917 ACQUIRE_LOCK(&sched_mutex);
918 if ( blackholes_need_checking ) {
919 checkBlackHoles(cap);
920 blackholes_need_checking = rtsFalse;
922 RELEASE_LOCK(&sched_mutex);
926 /* ----------------------------------------------------------------------------
927 * Detect deadlock conditions and attempt to resolve them.
928 * ------------------------------------------------------------------------- */
931 scheduleDetectDeadlock (Capability *cap, Task *task)
934 #if defined(PARALLEL_HASKELL)
935 // ToDo: add deadlock detection in GUM (similar to THREADED_RTS) -- HWL
940 * Detect deadlock: when we have no threads to run, there are no
941 * threads blocked, waiting for I/O, or sleeping, and all the
942 * other tasks are waiting for work, we must have a deadlock of
945 if ( emptyThreadQueues(cap) )
947 #if defined(THREADED_RTS)
949 * In the threaded RTS, we only check for deadlock if there
950 * has been no activity in a complete timeslice. This means
951 * we won't eagerly start a full GC just because we don't have
952 * any threads to run currently.
954 if (recent_activity != ACTIVITY_INACTIVE) return;
957 IF_DEBUG(scheduler, sched_belch("deadlocked, forcing major GC..."));
959 // Garbage collection can release some new threads due to
960 // either (a) finalizers or (b) threads resurrected because
961 // they are unreachable and will therefore be sent an
962 // exception. Any threads thus released will be immediately
964 cap = scheduleDoGC (cap, task, rtsTrue/*force major GC*/, GetRoots);
966 recent_activity = ACTIVITY_DONE_GC;
968 if ( !emptyRunQueue(cap) ) return;
970 #if defined(RTS_USER_SIGNALS) && (!defined(THREADED_RTS) || defined(mingw32_HOST_OS))
971 /* If we have user-installed signal handlers, then wait
972 * for signals to arrive rather then bombing out with a
975 if ( anyUserHandlers() ) {
977 sched_belch("still deadlocked, waiting for signals..."));
981 if (signals_pending()) {
982 startSignalHandlers(cap);
985 // either we have threads to run, or we were interrupted:
986 ASSERT(!emptyRunQueue(cap) || sched_state >= SCHED_INTERRUPTING);
990 #if !defined(THREADED_RTS)
991 /* Probably a real deadlock. Send the current main thread the
992 * Deadlock exception.
995 switch (task->tso->why_blocked) {
997 case BlockedOnBlackHole:
998 case BlockedOnException:
1000 raiseAsync(cap, task->tso, (StgClosure *)NonTermination_closure);
1003 barf("deadlock: main thread blocked in a strange way");
1011 /* ----------------------------------------------------------------------------
1012 * Process an event (GRAN only)
1013 * ------------------------------------------------------------------------- */
1017 scheduleProcessEvent(rtsEvent *event)
1021 if (RtsFlags.GranFlags.Light)
1022 GranSimLight_enter_system(event, &ActiveTSO); // adjust ActiveTSO etc
1024 /* adjust time based on time-stamp */
1025 if (event->time > CurrentTime[CurrentProc] &&
1026 event->evttype != ContinueThread)
1027 CurrentTime[CurrentProc] = event->time;
1029 /* Deal with the idle PEs (may issue FindWork or MoveSpark events) */
1030 if (!RtsFlags.GranFlags.Light)
1033 IF_DEBUG(gran, debugBelch("GRAN: switch by event-type\n"));
1035 /* main event dispatcher in GranSim */
1036 switch (event->evttype) {
1037 /* Should just be continuing execution */
1038 case ContinueThread:
1039 IF_DEBUG(gran, debugBelch("GRAN: doing ContinueThread\n"));
1040 /* ToDo: check assertion
1041 ASSERT(run_queue_hd != (StgTSO*)NULL &&
1042 run_queue_hd != END_TSO_QUEUE);
1044 /* Ignore ContinueThreads for fetching threads (if synchr comm) */
1045 if (!RtsFlags.GranFlags.DoAsyncFetch &&
1046 procStatus[CurrentProc]==Fetching) {
1047 debugBelch("ghuH: Spurious ContinueThread while Fetching ignored; TSO %d (%p) [PE %d]\n",
1048 CurrentTSO->id, CurrentTSO, CurrentProc);
1051 /* Ignore ContinueThreads for completed threads */
1052 if (CurrentTSO->what_next == ThreadComplete) {
1053 debugBelch("ghuH: found a ContinueThread event for completed thread %d (%p) [PE %d] (ignoring ContinueThread)\n",
1054 CurrentTSO->id, CurrentTSO, CurrentProc);
1057 /* Ignore ContinueThreads for threads that are being migrated */
1058 if (PROCS(CurrentTSO)==Nowhere) {
1059 debugBelch("ghuH: trying to run the migrating TSO %d (%p) [PE %d] (ignoring ContinueThread)\n",
1060 CurrentTSO->id, CurrentTSO, CurrentProc);
1063 /* The thread should be at the beginning of the run queue */
1064 if (CurrentTSO!=run_queue_hds[CurrentProc]) {
1065 debugBelch("ghuH: TSO %d (%p) [PE %d] is not at the start of the run_queue when doing a ContinueThread\n",
1066 CurrentTSO->id, CurrentTSO, CurrentProc);
1067 break; // run the thread anyway
1070 new_event(proc, proc, CurrentTime[proc],
1072 (StgTSO*)NULL, (StgClosure*)NULL, (rtsSpark*)NULL);
1074 */ /* Catches superfluous CONTINUEs -- should be unnecessary */
1075 break; // now actually run the thread; DaH Qu'vam yImuHbej
1078 do_the_fetchnode(event);
1079 goto next_thread; /* handle next event in event queue */
1082 do_the_globalblock(event);
1083 goto next_thread; /* handle next event in event queue */
1086 do_the_fetchreply(event);
1087 goto next_thread; /* handle next event in event queue */
1089 case UnblockThread: /* Move from the blocked queue to the tail of */
1090 do_the_unblock(event);
1091 goto next_thread; /* handle next event in event queue */
1093 case ResumeThread: /* Move from the blocked queue to the tail of */
1094 /* the runnable queue ( i.e. Qu' SImqa'lu') */
1095 event->tso->gran.blocktime +=
1096 CurrentTime[CurrentProc] - event->tso->gran.blockedat;
1097 do_the_startthread(event);
1098 goto next_thread; /* handle next event in event queue */
1101 do_the_startthread(event);
1102 goto next_thread; /* handle next event in event queue */
1105 do_the_movethread(event);
1106 goto next_thread; /* handle next event in event queue */
1109 do_the_movespark(event);
1110 goto next_thread; /* handle next event in event queue */
1113 do_the_findwork(event);
1114 goto next_thread; /* handle next event in event queue */
1117 barf("Illegal event type %u\n", event->evttype);
1120 /* This point was scheduler_loop in the old RTS */
1122 IF_DEBUG(gran, debugBelch("GRAN: after main switch\n"));
1124 TimeOfLastEvent = CurrentTime[CurrentProc];
1125 TimeOfNextEvent = get_time_of_next_event();
1126 IgnoreEvents=(TimeOfNextEvent==0); // HWL HACK
1127 // CurrentTSO = ThreadQueueHd;
1129 IF_DEBUG(gran, debugBelch("GRAN: time of next event is: %ld\n",
1132 if (RtsFlags.GranFlags.Light)
1133 GranSimLight_leave_system(event, &ActiveTSO);
1135 EndOfTimeSlice = CurrentTime[CurrentProc]+RtsFlags.GranFlags.time_slice;
1138 debugBelch("GRAN: end of time-slice is %#lx\n", EndOfTimeSlice));
1140 /* in a GranSim setup the TSO stays on the run queue */
1142 /* Take a thread from the run queue. */
1143 POP_RUN_QUEUE(t); // take_off_run_queue(t);
1146 debugBelch("GRAN: About to run current thread, which is\n");
1149 context_switch = 0; // turned on via GranYield, checking events and time slice
1152 DumpGranEvent(GR_SCHEDULE, t));
1154 procStatus[CurrentProc] = Busy;
1158 /* ----------------------------------------------------------------------------
1159 * Send pending messages (PARALLEL_HASKELL only)
1160 * ------------------------------------------------------------------------- */
1162 #if defined(PARALLEL_HASKELL)
1164 scheduleSendPendingMessages(void)
1170 # if defined(PAR) // global Mem.Mgmt., omit for now
1171 if (PendingFetches != END_BF_QUEUE) {
1176 if (RtsFlags.ParFlags.BufferTime) {
1177 // if we use message buffering, we must send away all message
1178 // packets which have become too old...
1184 /* ----------------------------------------------------------------------------
1185 * Activate spark threads (PARALLEL_HASKELL only)
1186 * ------------------------------------------------------------------------- */
1188 #if defined(PARALLEL_HASKELL)
1190 scheduleActivateSpark(void)
1193 ASSERT(emptyRunQueue());
1194 /* We get here if the run queue is empty and want some work.
1195 We try to turn a spark into a thread, and add it to the run queue,
1196 from where it will be picked up in the next iteration of the scheduler
1200 /* :-[ no local threads => look out for local sparks */
1201 /* the spark pool for the current PE */
1202 pool = &(cap.r.rSparks); // JB: cap = (old) MainCap
1203 if (advisory_thread_count < RtsFlags.ParFlags.maxThreads &&
1204 pool->hd < pool->tl) {
1206 * ToDo: add GC code check that we really have enough heap afterwards!!
1208 * If we're here (no runnable threads) and we have pending
1209 * sparks, we must have a space problem. Get enough space
1210 * to turn one of those pending sparks into a
1214 spark = findSpark(rtsFalse); /* get a spark */
1215 if (spark != (rtsSpark) NULL) {
1216 tso = createThreadFromSpark(spark); /* turn the spark into a thread */
1217 IF_PAR_DEBUG(fish, // schedule,
1218 debugBelch("==== schedule: Created TSO %d (%p); %d threads active\n",
1219 tso->id, tso, advisory_thread_count));
1221 if (tso==END_TSO_QUEUE) { /* failed to activate spark->back to loop */
1222 IF_PAR_DEBUG(fish, // schedule,
1223 debugBelch("==^^ failed to create thread from spark @ %lx\n",
1225 return rtsFalse; /* failed to generate a thread */
1226 } /* otherwise fall through & pick-up new tso */
1228 IF_PAR_DEBUG(fish, // schedule,
1229 debugBelch("==^^ no local sparks (spark pool contains only NFs: %d)\n",
1230 spark_queue_len(pool)));
1231 return rtsFalse; /* failed to generate a thread */
1233 return rtsTrue; /* success in generating a thread */
1234 } else { /* no more threads permitted or pool empty */
1235 return rtsFalse; /* failed to generateThread */
1238 tso = NULL; // avoid compiler warning only
1239 return rtsFalse; /* dummy in non-PAR setup */
1242 #endif // PARALLEL_HASKELL
1244 /* ----------------------------------------------------------------------------
1245 * Get work from a remote node (PARALLEL_HASKELL only)
1246 * ------------------------------------------------------------------------- */
1248 #if defined(PARALLEL_HASKELL)
1250 scheduleGetRemoteWork(rtsBool *receivedFinish)
1252 ASSERT(emptyRunQueue());
1254 if (RtsFlags.ParFlags.BufferTime) {
1255 IF_PAR_DEBUG(verbose,
1256 debugBelch("...send all pending data,"));
1259 for (i=1; i<=nPEs; i++)
1260 sendImmediately(i); // send all messages away immediately
1264 //++EDEN++ idle() , i.e. send all buffers, wait for work
1265 // suppress fishing in EDEN... just look for incoming messages
1266 // (blocking receive)
1267 IF_PAR_DEBUG(verbose,
1268 debugBelch("...wait for incoming messages...\n"));
1269 *receivedFinish = processMessages(); // blocking receive...
1271 // and reenter scheduling loop after having received something
1272 // (return rtsFalse below)
1274 # else /* activate SPARKS machinery */
1275 /* We get here, if we have no work, tried to activate a local spark, but still
1276 have no work. We try to get a remote spark, by sending a FISH message.
1277 Thread migration should be added here, and triggered when a sequence of
1278 fishes returns without work. */
1279 delay = (RtsFlags.ParFlags.fishDelay!=0ll ? RtsFlags.ParFlags.fishDelay : 0ll);
1281 /* =8-[ no local sparks => look for work on other PEs */
1283 * We really have absolutely no work. Send out a fish
1284 * (there may be some out there already), and wait for
1285 * something to arrive. We clearly can't run any threads
1286 * until a SCHEDULE or RESUME arrives, and so that's what
1287 * we're hoping to see. (Of course, we still have to
1288 * respond to other types of messages.)
1290 rtsTime now = msTime() /*CURRENT_TIME*/;
1291 IF_PAR_DEBUG(verbose,
1292 debugBelch("-- now=%ld\n", now));
1293 IF_PAR_DEBUG(fish, // verbose,
1294 if (outstandingFishes < RtsFlags.ParFlags.maxFishes &&
1295 (last_fish_arrived_at!=0 &&
1296 last_fish_arrived_at+delay > now)) {
1297 debugBelch("--$$ <%llu> delaying FISH until %llu (last fish %llu, delay %llu)\n",
1298 now, last_fish_arrived_at+delay,
1299 last_fish_arrived_at,
1303 if (outstandingFishes < RtsFlags.ParFlags.maxFishes &&
1304 advisory_thread_count < RtsFlags.ParFlags.maxThreads) { // send a FISH, but when?
1305 if (last_fish_arrived_at==0 ||
1306 (last_fish_arrived_at+delay <= now)) { // send FISH now!
1307 /* outstandingFishes is set in sendFish, processFish;
1308 avoid flooding system with fishes via delay */
1309 next_fish_to_send_at = 0;
1311 /* ToDo: this should be done in the main scheduling loop to avoid the
1312 busy wait here; not so bad if fish delay is very small */
1313 int iq = 0; // DEBUGGING -- HWL
1314 next_fish_to_send_at = last_fish_arrived_at+delay; // remember when to send
1315 /* send a fish when ready, but process messages that arrive in the meantime */
1317 if (PacketsWaiting()) {
1319 *receivedFinish = processMessages();
1322 } while (!*receivedFinish || now<next_fish_to_send_at);
1323 // JB: This means the fish could become obsolete, if we receive
1324 // work. Better check for work again?
1325 // last line: while (!receivedFinish || !haveWork || now<...)
1326 // next line: if (receivedFinish || haveWork )
1328 if (*receivedFinish) // no need to send a FISH if we are finishing anyway
1329 return rtsFalse; // NB: this will leave scheduler loop
1330 // immediately after return!
1332 IF_PAR_DEBUG(fish, // verbose,
1333 debugBelch("--$$ <%llu> sent delayed fish (%d processMessages); active/total threads=%d/%d\n",now,iq,run_queue_len(),advisory_thread_count));
1337 // JB: IMHO, this should all be hidden inside sendFish(...)
1339 sendFish(pe, thisPE, NEW_FISH_AGE, NEW_FISH_HISTORY,
1342 // Global statistics: count no. of fishes
1343 if (RtsFlags.ParFlags.ParStats.Global &&
1344 RtsFlags.GcFlags.giveStats > NO_GC_STATS) {
1345 globalParStats.tot_fish_mess++;
1349 /* delayed fishes must have been sent by now! */
1350 next_fish_to_send_at = 0;
1353 *receivedFinish = processMessages();
1354 # endif /* SPARKS */
1357 /* NB: this function always returns rtsFalse, meaning the scheduler
1358 loop continues with the next iteration;
1360 return code means success in finding work; we enter this function
1361 if there is no local work, thus have to send a fish which takes
1362 time until it arrives with work; in the meantime we should process
1363 messages in the main loop;
1366 #endif // PARALLEL_HASKELL
1368 /* ----------------------------------------------------------------------------
1369 * PAR/GRAN: Report stats & debugging info(?)
1370 * ------------------------------------------------------------------------- */
1372 #if defined(PAR) || defined(GRAN)
1374 scheduleGranParReport(void)
1376 ASSERT(run_queue_hd != END_TSO_QUEUE);
1378 /* Take a thread from the run queue, if we have work */
1379 POP_RUN_QUEUE(t); // take_off_run_queue(END_TSO_QUEUE);
1381 /* If this TSO has got its outport closed in the meantime,
1382 * it mustn't be run. Instead, we have to clean it up as if it was finished.
1383 * It has to be marked as TH_DEAD for this purpose.
1384 * If it is TH_TERM instead, it is supposed to have finished in the normal way.
1386 JB: TODO: investigate wether state change field could be nuked
1387 entirely and replaced by the normal tso state (whatnext
1388 field). All we want to do is to kill tsos from outside.
1391 /* ToDo: write something to the log-file
1392 if (RTSflags.ParFlags.granSimStats && !sameThread)
1393 DumpGranEvent(GR_SCHEDULE, RunnableThreadsHd);
1397 /* the spark pool for the current PE */
1398 pool = &(cap.r.rSparks); // cap = (old) MainCap
1401 debugBelch("--=^ %d threads, %d sparks on [%#x]\n",
1402 run_queue_len(), spark_queue_len(pool), CURRENT_PROC));
1405 debugBelch("--=^ %d threads, %d sparks on [%#x]\n",
1406 run_queue_len(), spark_queue_len(pool), CURRENT_PROC));
1408 if (RtsFlags.ParFlags.ParStats.Full &&
1409 (t->par.sparkname != (StgInt)0) && // only log spark generated threads
1410 (emitSchedule || // forced emit
1411 (t && LastTSO && t->id != LastTSO->id))) {
1413 we are running a different TSO, so write a schedule event to log file
1414 NB: If we use fair scheduling we also have to write a deschedule
1415 event for LastTSO; with unfair scheduling we know that the
1416 previous tso has blocked whenever we switch to another tso, so
1417 we don't need it in GUM for now
1419 IF_PAR_DEBUG(fish, // schedule,
1420 debugBelch("____ scheduling spark generated thread %d (%lx) (%lx) via a forced emit\n",t->id,t,t->par.sparkname));
1422 DumpRawGranEvent(CURRENT_PROC, CURRENT_PROC,
1423 GR_SCHEDULE, t, (StgClosure *)NULL, 0, 0);
1424 emitSchedule = rtsFalse;
1429 /* ----------------------------------------------------------------------------
1430 * After running a thread...
1431 * ------------------------------------------------------------------------- */
1434 schedulePostRunThread(void)
1437 /* HACK 675: if the last thread didn't yield, make sure to print a
1438 SCHEDULE event to the log file when StgRunning the next thread, even
1439 if it is the same one as before */
1441 TimeOfLastYield = CURRENT_TIME;
1444 /* some statistics gathering in the parallel case */
1446 #if defined(GRAN) || defined(PAR) || defined(EDEN)
1450 IF_DEBUG(gran, DumpGranEvent(GR_DESCHEDULE, t));
1451 globalGranStats.tot_heapover++;
1453 globalParStats.tot_heapover++;
1460 DumpGranEvent(GR_DESCHEDULE, t));
1461 globalGranStats.tot_stackover++;
1464 // DumpGranEvent(GR_DESCHEDULE, t);
1465 globalParStats.tot_stackover++;
1469 case ThreadYielding:
1472 DumpGranEvent(GR_DESCHEDULE, t));
1473 globalGranStats.tot_yields++;
1476 // DumpGranEvent(GR_DESCHEDULE, t);
1477 globalParStats.tot_yields++;
1484 debugBelch("--<< thread %ld (%p; %s) stopped, blocking on node %p [PE %d] with BQ: ",
1485 t->id, t, whatNext_strs[t->what_next], t->block_info.closure,
1486 (t->block_info.closure==(StgClosure*)NULL ? 99 : where_is(t->block_info.closure)));
1487 if (t->block_info.closure!=(StgClosure*)NULL)
1488 print_bq(t->block_info.closure);
1491 // ??? needed; should emit block before
1493 DumpGranEvent(GR_DESCHEDULE, t));
1494 prune_eventq(t, (StgClosure *)NULL); // prune ContinueThreads for t
1497 ASSERT(procStatus[CurrentProc]==Busy ||
1498 ((procStatus[CurrentProc]==Fetching) &&
1499 (t->block_info.closure!=(StgClosure*)NULL)));
1500 if (run_queue_hds[CurrentProc] == END_TSO_QUEUE &&
1501 !(!RtsFlags.GranFlags.DoAsyncFetch &&
1502 procStatus[CurrentProc]==Fetching))
1503 procStatus[CurrentProc] = Idle;
1506 //++PAR++ blockThread() writes the event (change?)
1510 case ThreadFinished:
1514 barf("parGlobalStats: unknown return code");
1520 /* -----------------------------------------------------------------------------
1521 * Handle a thread that returned to the scheduler with ThreadHeepOverflow
1522 * -------------------------------------------------------------------------- */
1525 scheduleHandleHeapOverflow( Capability *cap, StgTSO *t )
1527 // did the task ask for a large block?
1528 if (cap->r.rHpAlloc > BLOCK_SIZE) {
1529 // if so, get one and push it on the front of the nursery.
1533 blocks = (lnat)BLOCK_ROUND_UP(cap->r.rHpAlloc) / BLOCK_SIZE;
1536 debugBelch("--<< thread %ld (%s) stopped: requesting a large block (size %ld)\n",
1537 (long)t->id, whatNext_strs[t->what_next], blocks));
1539 // don't do this if the nursery is (nearly) full, we'll GC first.
1540 if (cap->r.rCurrentNursery->link != NULL ||
1541 cap->r.rNursery->n_blocks == 1) { // paranoia to prevent infinite loop
1542 // if the nursery has only one block.
1545 bd = allocGroup( blocks );
1547 cap->r.rNursery->n_blocks += blocks;
1549 // link the new group into the list
1550 bd->link = cap->r.rCurrentNursery;
1551 bd->u.back = cap->r.rCurrentNursery->u.back;
1552 if (cap->r.rCurrentNursery->u.back != NULL) {
1553 cap->r.rCurrentNursery->u.back->link = bd;
1555 #if !defined(THREADED_RTS)
1556 ASSERT(g0s0->blocks == cap->r.rCurrentNursery &&
1557 g0s0 == cap->r.rNursery);
1559 cap->r.rNursery->blocks = bd;
1561 cap->r.rCurrentNursery->u.back = bd;
1563 // initialise it as a nursery block. We initialise the
1564 // step, gen_no, and flags field of *every* sub-block in
1565 // this large block, because this is easier than making
1566 // sure that we always find the block head of a large
1567 // block whenever we call Bdescr() (eg. evacuate() and
1568 // isAlive() in the GC would both have to do this, at
1572 for (x = bd; x < bd + blocks; x++) {
1573 x->step = cap->r.rNursery;
1579 // This assert can be a killer if the app is doing lots
1580 // of large block allocations.
1581 IF_DEBUG(sanity, checkNurserySanity(cap->r.rNursery));
1583 // now update the nursery to point to the new block
1584 cap->r.rCurrentNursery = bd;
1586 // we might be unlucky and have another thread get on the
1587 // run queue before us and steal the large block, but in that
1588 // case the thread will just end up requesting another large
1590 pushOnRunQueue(cap,t);
1591 return rtsFalse; /* not actually GC'ing */
1596 debugBelch("--<< thread %ld (%s) stopped: HeapOverflow\n",
1597 (long)t->id, whatNext_strs[t->what_next]));
1599 ASSERT(!is_on_queue(t,CurrentProc));
1600 #elif defined(PARALLEL_HASKELL)
1601 /* Currently we emit a DESCHEDULE event before GC in GUM.
1602 ToDo: either add separate event to distinguish SYSTEM time from rest
1603 or just nuke this DESCHEDULE (and the following SCHEDULE) */
1604 if (0 && RtsFlags.ParFlags.ParStats.Full) {
1605 DumpRawGranEvent(CURRENT_PROC, CURRENT_PROC,
1606 GR_DESCHEDULE, t, (StgClosure *)NULL, 0, 0);
1607 emitSchedule = rtsTrue;
1611 pushOnRunQueue(cap,t);
1613 /* actual GC is done at the end of the while loop in schedule() */
1616 /* -----------------------------------------------------------------------------
1617 * Handle a thread that returned to the scheduler with ThreadStackOverflow
1618 * -------------------------------------------------------------------------- */
1621 scheduleHandleStackOverflow (Capability *cap, Task *task, StgTSO *t)
1623 IF_DEBUG(scheduler,debugBelch("--<< thread %ld (%s) stopped, StackOverflow\n",
1624 (long)t->id, whatNext_strs[t->what_next]));
1625 /* just adjust the stack for this thread, then pop it back
1629 /* enlarge the stack */
1630 StgTSO *new_t = threadStackOverflow(cap, t);
1632 /* The TSO attached to this Task may have moved, so update the
1635 if (task->tso == t) {
1638 pushOnRunQueue(cap,new_t);
1642 /* -----------------------------------------------------------------------------
1643 * Handle a thread that returned to the scheduler with ThreadYielding
1644 * -------------------------------------------------------------------------- */
1647 scheduleHandleYield( Capability *cap, StgTSO *t, nat prev_what_next )
1649 // Reset the context switch flag. We don't do this just before
1650 // running the thread, because that would mean we would lose ticks
1651 // during GC, which can lead to unfair scheduling (a thread hogs
1652 // the CPU because the tick always arrives during GC). This way
1653 // penalises threads that do a lot of allocation, but that seems
1654 // better than the alternative.
1657 /* put the thread back on the run queue. Then, if we're ready to
1658 * GC, check whether this is the last task to stop. If so, wake
1659 * up the GC thread. getThread will block during a GC until the
1663 if (t->what_next != prev_what_next) {
1664 debugBelch("--<< thread %ld (%s) stopped to switch evaluators\n",
1665 (long)t->id, whatNext_strs[t->what_next]);
1667 debugBelch("--<< thread %ld (%s) stopped, yielding\n",
1668 (long)t->id, whatNext_strs[t->what_next]);
1673 //debugBelch("&& Doing sanity check on yielding TSO %ld.", t->id);
1675 ASSERT(t->link == END_TSO_QUEUE);
1677 // Shortcut if we're just switching evaluators: don't bother
1678 // doing stack squeezing (which can be expensive), just run the
1680 if (t->what_next != prev_what_next) {
1685 ASSERT(!is_on_queue(t,CurrentProc));
1688 //debugBelch("&& Doing sanity check on all ThreadQueues (and their TSOs).");
1689 checkThreadQsSanity(rtsTrue));
1693 addToRunQueue(cap,t);
1696 /* add a ContinueThread event to actually process the thread */
1697 new_event(CurrentProc, CurrentProc, CurrentTime[CurrentProc],
1699 t, (StgClosure*)NULL, (rtsSpark*)NULL);
1701 debugBelch("GRAN: eventq and runnableq after adding yielded thread to queue again:\n");
1708 /* -----------------------------------------------------------------------------
1709 * Handle a thread that returned to the scheduler with ThreadBlocked
1710 * -------------------------------------------------------------------------- */
1713 scheduleHandleThreadBlocked( StgTSO *t
1714 #if !defined(GRAN) && !defined(DEBUG)
1721 debugBelch("--<< thread %ld (%p; %s) stopped, blocking on node %p [PE %d] with BQ: \n",
1722 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)));
1723 if (t->block_info.closure!=(StgClosure*)NULL) print_bq(t->block_info.closure));
1725 // ??? needed; should emit block before
1727 DumpGranEvent(GR_DESCHEDULE, t));
1728 prune_eventq(t, (StgClosure *)NULL); // prune ContinueThreads for t
1731 ASSERT(procStatus[CurrentProc]==Busy ||
1732 ((procStatus[CurrentProc]==Fetching) &&
1733 (t->block_info.closure!=(StgClosure*)NULL)));
1734 if (run_queue_hds[CurrentProc] == END_TSO_QUEUE &&
1735 !(!RtsFlags.GranFlags.DoAsyncFetch &&
1736 procStatus[CurrentProc]==Fetching))
1737 procStatus[CurrentProc] = Idle;
1741 debugBelch("--<< thread %ld (%p; %s) stopped, blocking on node %p with BQ: \n",
1742 t->id, t, whatNext_strs[t->what_next], t->block_info.closure));
1745 if (t->block_info.closure!=(StgClosure*)NULL)
1746 print_bq(t->block_info.closure));
1748 /* Send a fetch (if BlockedOnGA) and dump event to log file */
1751 /* whatever we schedule next, we must log that schedule */
1752 emitSchedule = rtsTrue;
1756 // We don't need to do anything. The thread is blocked, and it
1757 // has tidied up its stack and placed itself on whatever queue
1758 // it needs to be on.
1760 #if !defined(THREADED_RTS)
1761 ASSERT(t->why_blocked != NotBlocked);
1762 // This might not be true under THREADED_RTS: we don't have
1763 // exclusive access to this TSO, so someone might have
1764 // woken it up by now. This actually happens: try
1765 // conc023 +RTS -N2.
1769 debugBelch("--<< thread %d (%s) stopped: ",
1770 t->id, whatNext_strs[t->what_next]);
1771 printThreadBlockage(t);
1774 /* Only for dumping event to log file
1775 ToDo: do I need this in GranSim, too?
1781 /* -----------------------------------------------------------------------------
1782 * Handle a thread that returned to the scheduler with ThreadFinished
1783 * -------------------------------------------------------------------------- */
1786 scheduleHandleThreadFinished (Capability *cap STG_UNUSED, Task *task, StgTSO *t)
1788 /* Need to check whether this was a main thread, and if so,
1789 * return with the return value.
1791 * We also end up here if the thread kills itself with an
1792 * uncaught exception, see Exception.cmm.
1794 IF_DEBUG(scheduler,debugBelch("--++ thread %d (%s) finished\n",
1795 t->id, whatNext_strs[t->what_next]));
1798 endThread(t, CurrentProc); // clean-up the thread
1799 #elif defined(PARALLEL_HASKELL)
1800 /* For now all are advisory -- HWL */
1801 //if(t->priority==AdvisoryPriority) ??
1802 advisory_thread_count--; // JB: Caution with this counter, buggy!
1805 if(t->dist.priority==RevalPriority)
1809 # if defined(EDENOLD)
1810 // the thread could still have an outport... (BUG)
1811 if (t->eden.outport != -1) {
1812 // delete the outport for the tso which has finished...
1813 IF_PAR_DEBUG(eden_ports,
1814 debugBelch("WARNING: Scheduler removes outport %d for TSO %d.\n",
1815 t->eden.outport, t->id));
1818 // thread still in the process (HEAVY BUG! since outport has just been closed...)
1819 if (t->eden.epid != -1) {
1820 IF_PAR_DEBUG(eden_ports,
1821 debugBelch("WARNING: Scheduler removes TSO %d from process %d .\n",
1822 t->id, t->eden.epid));
1823 removeTSOfromProcess(t);
1828 if (RtsFlags.ParFlags.ParStats.Full &&
1829 !RtsFlags.ParFlags.ParStats.Suppressed)
1830 DumpEndEvent(CURRENT_PROC, t, rtsFalse /* not mandatory */);
1832 // t->par only contains statistics: left out for now...
1834 debugBelch("**** end thread: ended sparked thread %d (%lx); sparkname: %lx\n",
1835 t->id,t,t->par.sparkname));
1837 #endif // PARALLEL_HASKELL
1840 // Check whether the thread that just completed was a bound
1841 // thread, and if so return with the result.
1843 // There is an assumption here that all thread completion goes
1844 // through this point; we need to make sure that if a thread
1845 // ends up in the ThreadKilled state, that it stays on the run
1846 // queue so it can be dealt with here.
1851 if (t->bound != task) {
1852 #if !defined(THREADED_RTS)
1853 // Must be a bound thread that is not the topmost one. Leave
1854 // it on the run queue until the stack has unwound to the
1855 // point where we can deal with this. Leaving it on the run
1856 // queue also ensures that the garbage collector knows about
1857 // this thread and its return value (it gets dropped from the
1858 // all_threads list so there's no other way to find it).
1859 appendToRunQueue(cap,t);
1862 // this cannot happen in the threaded RTS, because a
1863 // bound thread can only be run by the appropriate Task.
1864 barf("finished bound thread that isn't mine");
1868 ASSERT(task->tso == t);
1870 if (t->what_next == ThreadComplete) {
1872 // NOTE: return val is tso->sp[1] (see StgStartup.hc)
1873 *(task->ret) = (StgClosure *)task->tso->sp[1];
1875 task->stat = Success;
1878 *(task->ret) = NULL;
1880 if (sched_state >= SCHED_INTERRUPTING) {
1881 task->stat = Interrupted;
1883 task->stat = Killed;
1887 removeThreadLabel((StgWord)task->tso->id);
1889 return rtsTrue; // tells schedule() to return
1895 /* -----------------------------------------------------------------------------
1896 * Perform a heap census, if PROFILING
1897 * -------------------------------------------------------------------------- */
1900 scheduleDoHeapProfile( rtsBool ready_to_gc STG_UNUSED )
1902 #if defined(PROFILING)
1903 // When we have +RTS -i0 and we're heap profiling, do a census at
1904 // every GC. This lets us get repeatable runs for debugging.
1905 if (performHeapProfile ||
1906 (RtsFlags.ProfFlags.profileInterval==0 &&
1907 RtsFlags.ProfFlags.doHeapProfile && ready_to_gc)) {
1909 // checking black holes is necessary before GC, otherwise
1910 // there may be threads that are unreachable except by the
1911 // blackhole queue, which the GC will consider to be
1913 scheduleCheckBlackHoles(&MainCapability);
1915 IF_DEBUG(scheduler, sched_belch("garbage collecting before heap census"));
1916 GarbageCollect(GetRoots, rtsTrue);
1918 IF_DEBUG(scheduler, sched_belch("performing heap census"));
1921 performHeapProfile = rtsFalse;
1922 return rtsTrue; // true <=> we already GC'd
1928 /* -----------------------------------------------------------------------------
1929 * Perform a garbage collection if necessary
1930 * -------------------------------------------------------------------------- */
1933 scheduleDoGC (Capability *cap, Task *task USED_IF_THREADS,
1934 rtsBool force_major, void (*get_roots)(evac_fn))
1938 static volatile StgWord waiting_for_gc;
1939 rtsBool was_waiting;
1944 // In order to GC, there must be no threads running Haskell code.
1945 // Therefore, the GC thread needs to hold *all* the capabilities,
1946 // and release them after the GC has completed.
1948 // This seems to be the simplest way: previous attempts involved
1949 // making all the threads with capabilities give up their
1950 // capabilities and sleep except for the *last* one, which
1951 // actually did the GC. But it's quite hard to arrange for all
1952 // the other tasks to sleep and stay asleep.
1955 was_waiting = cas(&waiting_for_gc, 0, 1);
1958 IF_DEBUG(scheduler, sched_belch("someone else is trying to GC..."));
1959 if (cap) yieldCapability(&cap,task);
1960 } while (waiting_for_gc);
1961 return cap; // NOTE: task->cap might have changed here
1964 for (i=0; i < n_capabilities; i++) {
1965 IF_DEBUG(scheduler, sched_belch("ready_to_gc, grabbing all the capabilies (%d/%d)", i, n_capabilities));
1966 if (cap != &capabilities[i]) {
1967 Capability *pcap = &capabilities[i];
1968 // we better hope this task doesn't get migrated to
1969 // another Capability while we're waiting for this one.
1970 // It won't, because load balancing happens while we have
1971 // all the Capabilities, but even so it's a slightly
1972 // unsavoury invariant.
1975 waitForReturnCapability(&pcap, task);
1976 if (pcap != &capabilities[i]) {
1977 barf("scheduleDoGC: got the wrong capability");
1982 waiting_for_gc = rtsFalse;
1985 /* Kick any transactions which are invalid back to their
1986 * atomically frames. When next scheduled they will try to
1987 * commit, this commit will fail and they will retry.
1992 for (t = all_threads; t != END_TSO_QUEUE; t = next) {
1993 if (t->what_next == ThreadRelocated) {
1996 next = t->global_link;
1997 if (t -> trec != NO_TREC && t -> why_blocked == NotBlocked) {
1998 if (!stmValidateNestOfTransactions (t -> trec)) {
1999 IF_DEBUG(stm, sched_belch("trec %p found wasting its time", t));
2001 // strip the stack back to the
2002 // ATOMICALLY_FRAME, aborting the (nested)
2003 // transaction, and saving the stack of any
2004 // partially-evaluated thunks on the heap.
2005 raiseAsync_(&capabilities[0], t, NULL, rtsTrue, NULL);
2008 ASSERT(get_itbl((StgClosure *)t->sp)->type == ATOMICALLY_FRAME);
2016 // so this happens periodically:
2017 if (cap) scheduleCheckBlackHoles(cap);
2019 IF_DEBUG(scheduler, printAllThreads());
2022 * We now have all the capabilities; if we're in an interrupting
2023 * state, then we should take the opportunity to delete all the
2024 * threads in the system.
2026 if (sched_state >= SCHED_INTERRUPTING) {
2027 deleteAllThreads(&capabilities[0]);
2028 sched_state = SCHED_INTERRUPTED;
2031 /* everybody back, start the GC.
2032 * Could do it in this thread, or signal a condition var
2033 * to do it in another thread. Either way, we need to
2034 * broadcast on gc_pending_cond afterward.
2036 #if defined(THREADED_RTS)
2037 IF_DEBUG(scheduler,sched_belch("doing GC"));
2039 GarbageCollect(get_roots, force_major);
2041 #if defined(THREADED_RTS)
2042 // release our stash of capabilities.
2043 for (i = 0; i < n_capabilities; i++) {
2044 if (cap != &capabilities[i]) {
2045 task->cap = &capabilities[i];
2046 releaseCapability(&capabilities[i]);
2057 /* add a ContinueThread event to continue execution of current thread */
2058 new_event(CurrentProc, CurrentProc, CurrentTime[CurrentProc],
2060 t, (StgClosure*)NULL, (rtsSpark*)NULL);
2062 debugBelch("GRAN: eventq and runnableq after Garbage collection:\n\n");
2070 /* ---------------------------------------------------------------------------
2071 * rtsSupportsBoundThreads(): is the RTS built to support bound threads?
2072 * used by Control.Concurrent for error checking.
2073 * ------------------------------------------------------------------------- */
2076 rtsSupportsBoundThreads(void)
2078 #if defined(THREADED_RTS)
2085 /* ---------------------------------------------------------------------------
2086 * isThreadBound(tso): check whether tso is bound to an OS thread.
2087 * ------------------------------------------------------------------------- */
2090 isThreadBound(StgTSO* tso USED_IF_THREADS)
2092 #if defined(THREADED_RTS)
2093 return (tso->bound != NULL);
2098 /* ---------------------------------------------------------------------------
2099 * Singleton fork(). Do not copy any running threads.
2100 * ------------------------------------------------------------------------- */
2102 #if !defined(mingw32_HOST_OS)
2103 #define FORKPROCESS_PRIMOP_SUPPORTED
2106 #ifdef FORKPROCESS_PRIMOP_SUPPORTED
2108 deleteThreadImmediately(Capability *cap, StgTSO *tso);
2111 forkProcess(HsStablePtr *entry
2112 #ifndef FORKPROCESS_PRIMOP_SUPPORTED
2117 #ifdef FORKPROCESS_PRIMOP_SUPPORTED
2123 #if defined(THREADED_RTS)
2124 if (RtsFlags.ParFlags.nNodes > 1) {
2125 errorBelch("forking not supported with +RTS -N<n> greater than 1");
2126 stg_exit(EXIT_FAILURE);
2130 IF_DEBUG(scheduler,sched_belch("forking!"));
2132 // ToDo: for SMP, we should probably acquire *all* the capabilities
2137 if (pid) { // parent
2139 // just return the pid
2145 // delete all threads
2146 cap->run_queue_hd = END_TSO_QUEUE;
2147 cap->run_queue_tl = END_TSO_QUEUE;
2149 for (t = all_threads; t != END_TSO_QUEUE; t = next) {
2152 // don't allow threads to catch the ThreadKilled exception
2153 deleteThreadImmediately(cap,t);
2156 // wipe the task list
2157 ACQUIRE_LOCK(&sched_mutex);
2158 for (task = all_tasks; task != NULL; task=task->all_link) {
2159 if (task != cap->running_task) discardTask(task);
2161 RELEASE_LOCK(&sched_mutex);
2163 cap->suspended_ccalling_tasks = NULL;
2165 #if defined(THREADED_RTS)
2166 // wipe our spare workers list.
2167 cap->spare_workers = NULL;
2168 cap->returning_tasks_hd = NULL;
2169 cap->returning_tasks_tl = NULL;
2172 cap = rts_evalStableIO(cap, entry, NULL); // run the action
2173 rts_checkSchedStatus("forkProcess",cap);
2176 hs_exit(); // clean up and exit
2177 stg_exit(EXIT_SUCCESS);
2179 #else /* !FORKPROCESS_PRIMOP_SUPPORTED */
2180 barf("forkProcess#: primop not supported on this platform, sorry!\n");
2185 /* ---------------------------------------------------------------------------
2186 * Delete all the threads in the system
2187 * ------------------------------------------------------------------------- */
2190 deleteAllThreads ( Capability *cap )
2193 IF_DEBUG(scheduler,sched_belch("deleting all threads"));
2194 for (t = all_threads; t != END_TSO_QUEUE; t = next) {
2195 if (t->what_next == ThreadRelocated) {
2198 next = t->global_link;
2199 deleteThread(cap,t);
2203 // The run queue now contains a bunch of ThreadKilled threads. We
2204 // must not throw these away: the main thread(s) will be in there
2205 // somewhere, and the main scheduler loop has to deal with it.
2206 // Also, the run queue is the only thing keeping these threads from
2207 // being GC'd, and we don't want the "main thread has been GC'd" panic.
2209 #if !defined(THREADED_RTS)
2210 ASSERT(blocked_queue_hd == END_TSO_QUEUE);
2211 ASSERT(sleeping_queue == END_TSO_QUEUE);
2215 /* -----------------------------------------------------------------------------
2216 Managing the suspended_ccalling_tasks list.
2217 Locks required: sched_mutex
2218 -------------------------------------------------------------------------- */
2221 suspendTask (Capability *cap, Task *task)
2223 ASSERT(task->next == NULL && task->prev == NULL);
2224 task->next = cap->suspended_ccalling_tasks;
2226 if (cap->suspended_ccalling_tasks) {
2227 cap->suspended_ccalling_tasks->prev = task;
2229 cap->suspended_ccalling_tasks = task;
2233 recoverSuspendedTask (Capability *cap, Task *task)
2236 task->prev->next = task->next;
2238 ASSERT(cap->suspended_ccalling_tasks == task);
2239 cap->suspended_ccalling_tasks = task->next;
2242 task->next->prev = task->prev;
2244 task->next = task->prev = NULL;
2247 /* ---------------------------------------------------------------------------
2248 * Suspending & resuming Haskell threads.
2250 * When making a "safe" call to C (aka _ccall_GC), the task gives back
2251 * its capability before calling the C function. This allows another
2252 * task to pick up the capability and carry on running Haskell
2253 * threads. It also means that if the C call blocks, it won't lock
2256 * The Haskell thread making the C call is put to sleep for the
2257 * duration of the call, on the susepended_ccalling_threads queue. We
2258 * give out a token to the task, which it can use to resume the thread
2259 * on return from the C function.
2260 * ------------------------------------------------------------------------- */
2263 suspendThread (StgRegTable *reg)
2266 int saved_errno = errno;
2270 /* assume that *reg is a pointer to the StgRegTable part of a Capability.
2272 cap = regTableToCapability(reg);
2274 task = cap->running_task;
2275 tso = cap->r.rCurrentTSO;
2278 sched_belch("thread %d did a safe foreign call", cap->r.rCurrentTSO->id));
2280 // XXX this might not be necessary --SDM
2281 tso->what_next = ThreadRunGHC;
2283 threadPaused(cap,tso);
2285 if(tso->blocked_exceptions == NULL) {
2286 tso->why_blocked = BlockedOnCCall;
2287 tso->blocked_exceptions = END_TSO_QUEUE;
2289 tso->why_blocked = BlockedOnCCall_NoUnblockExc;
2292 // Hand back capability
2293 task->suspended_tso = tso;
2295 ACQUIRE_LOCK(&cap->lock);
2297 suspendTask(cap,task);
2298 cap->in_haskell = rtsFalse;
2299 releaseCapability_(cap);
2301 RELEASE_LOCK(&cap->lock);
2303 #if defined(THREADED_RTS)
2304 /* Preparing to leave the RTS, so ensure there's a native thread/task
2305 waiting to take over.
2307 IF_DEBUG(scheduler, sched_belch("thread %d: leaving RTS", tso->id));
2310 errno = saved_errno;
2315 resumeThread (void *task_)
2319 int saved_errno = errno;
2323 // Wait for permission to re-enter the RTS with the result.
2324 waitForReturnCapability(&cap,task);
2325 // we might be on a different capability now... but if so, our
2326 // entry on the suspended_ccalling_tasks list will also have been
2329 // Remove the thread from the suspended list
2330 recoverSuspendedTask(cap,task);
2332 tso = task->suspended_tso;
2333 task->suspended_tso = NULL;
2334 tso->link = END_TSO_QUEUE;
2335 IF_DEBUG(scheduler, sched_belch("thread %d: re-entering RTS", tso->id));
2337 if (tso->why_blocked == BlockedOnCCall) {
2338 awakenBlockedQueue(cap,tso->blocked_exceptions);
2339 tso->blocked_exceptions = NULL;
2342 /* Reset blocking status */
2343 tso->why_blocked = NotBlocked;
2345 cap->r.rCurrentTSO = tso;
2346 cap->in_haskell = rtsTrue;
2347 errno = saved_errno;
2349 /* We might have GC'd, mark the TSO dirty again */
2352 IF_DEBUG(sanity, checkTSO(tso));
2357 /* ---------------------------------------------------------------------------
2358 * Comparing Thread ids.
2360 * This is used from STG land in the implementation of the
2361 * instances of Eq/Ord for ThreadIds.
2362 * ------------------------------------------------------------------------ */
2365 cmp_thread(StgPtr tso1, StgPtr tso2)
2367 StgThreadID id1 = ((StgTSO *)tso1)->id;
2368 StgThreadID id2 = ((StgTSO *)tso2)->id;
2370 if (id1 < id2) return (-1);
2371 if (id1 > id2) return 1;
2375 /* ---------------------------------------------------------------------------
2376 * Fetching the ThreadID from an StgTSO.
2378 * This is used in the implementation of Show for ThreadIds.
2379 * ------------------------------------------------------------------------ */
2381 rts_getThreadId(StgPtr tso)
2383 return ((StgTSO *)tso)->id;
2388 labelThread(StgPtr tso, char *label)
2393 /* Caveat: Once set, you can only set the thread name to "" */
2394 len = strlen(label)+1;
2395 buf = stgMallocBytes(len * sizeof(char), "Schedule.c:labelThread()");
2396 strncpy(buf,label,len);
2397 /* Update will free the old memory for us */
2398 updateThreadLabel(((StgTSO *)tso)->id,buf);
2402 /* ---------------------------------------------------------------------------
2403 Create a new thread.
2405 The new thread starts with the given stack size. Before the
2406 scheduler can run, however, this thread needs to have a closure
2407 (and possibly some arguments) pushed on its stack. See
2408 pushClosure() in Schedule.h.
2410 createGenThread() and createIOThread() (in SchedAPI.h) are
2411 convenient packaged versions of this function.
2413 currently pri (priority) is only used in a GRAN setup -- HWL
2414 ------------------------------------------------------------------------ */
2416 /* currently pri (priority) is only used in a GRAN setup -- HWL */
2418 createThread(nat size, StgInt pri)
2421 createThread(Capability *cap, nat size)
2427 /* sched_mutex is *not* required */
2429 /* First check whether we should create a thread at all */
2430 #if defined(PARALLEL_HASKELL)
2431 /* check that no more than RtsFlags.ParFlags.maxThreads threads are created */
2432 if (advisory_thread_count >= RtsFlags.ParFlags.maxThreads) {
2434 debugBelch("{createThread}Daq ghuH: refusing to create another thread; no more than %d threads allowed (currently %d)\n",
2435 RtsFlags.ParFlags.maxThreads, advisory_thread_count);
2436 return END_TSO_QUEUE;
2442 ASSERT(!RtsFlags.GranFlags.Light || CurrentProc==0);
2445 // ToDo: check whether size = stack_size - TSO_STRUCT_SIZEW
2447 /* catch ridiculously small stack sizes */
2448 if (size < MIN_STACK_WORDS + TSO_STRUCT_SIZEW) {
2449 size = MIN_STACK_WORDS + TSO_STRUCT_SIZEW;
2452 stack_size = size - TSO_STRUCT_SIZEW;
2454 tso = (StgTSO *)allocateLocal(cap, size);
2455 TICK_ALLOC_TSO(stack_size, 0);
2457 SET_HDR(tso, &stg_TSO_info, CCS_SYSTEM);
2459 SET_GRAN_HDR(tso, ThisPE);
2462 // Always start with the compiled code evaluator
2463 tso->what_next = ThreadRunGHC;
2465 tso->why_blocked = NotBlocked;
2466 tso->blocked_exceptions = NULL;
2467 tso->flags = TSO_DIRTY;
2469 tso->saved_errno = 0;
2472 tso->stack_size = stack_size;
2473 tso->max_stack_size = round_to_mblocks(RtsFlags.GcFlags.maxStkSize)
2475 tso->sp = (P_)&(tso->stack) + stack_size;
2477 tso->trec = NO_TREC;
2480 tso->prof.CCCS = CCS_MAIN;
2483 /* put a stop frame on the stack */
2484 tso->sp -= sizeofW(StgStopFrame);
2485 SET_HDR((StgClosure*)tso->sp,(StgInfoTable *)&stg_stop_thread_info,CCS_SYSTEM);
2486 tso->link = END_TSO_QUEUE;
2490 /* uses more flexible routine in GranSim */
2491 insertThread(tso, CurrentProc);
2493 /* In a non-GranSim setup the pushing of a TSO onto the runq is separated
2499 if (RtsFlags.GranFlags.GranSimStats.Full)
2500 DumpGranEvent(GR_START,tso);
2501 #elif defined(PARALLEL_HASKELL)
2502 if (RtsFlags.ParFlags.ParStats.Full)
2503 DumpGranEvent(GR_STARTQ,tso);
2504 /* HACk to avoid SCHEDULE
2508 /* Link the new thread on the global thread list.
2510 ACQUIRE_LOCK(&sched_mutex);
2511 tso->id = next_thread_id++; // while we have the mutex
2512 tso->global_link = all_threads;
2514 RELEASE_LOCK(&sched_mutex);
2517 tso->dist.priority = MandatoryPriority; //by default that is...
2521 tso->gran.pri = pri;
2523 tso->gran.magic = TSO_MAGIC; // debugging only
2525 tso->gran.sparkname = 0;
2526 tso->gran.startedat = CURRENT_TIME;
2527 tso->gran.exported = 0;
2528 tso->gran.basicblocks = 0;
2529 tso->gran.allocs = 0;
2530 tso->gran.exectime = 0;
2531 tso->gran.fetchtime = 0;
2532 tso->gran.fetchcount = 0;
2533 tso->gran.blocktime = 0;
2534 tso->gran.blockcount = 0;
2535 tso->gran.blockedat = 0;
2536 tso->gran.globalsparks = 0;
2537 tso->gran.localsparks = 0;
2538 if (RtsFlags.GranFlags.Light)
2539 tso->gran.clock = Now; /* local clock */
2541 tso->gran.clock = 0;
2543 IF_DEBUG(gran,printTSO(tso));
2544 #elif defined(PARALLEL_HASKELL)
2546 tso->par.magic = TSO_MAGIC; // debugging only
2548 tso->par.sparkname = 0;
2549 tso->par.startedat = CURRENT_TIME;
2550 tso->par.exported = 0;
2551 tso->par.basicblocks = 0;
2552 tso->par.allocs = 0;
2553 tso->par.exectime = 0;
2554 tso->par.fetchtime = 0;
2555 tso->par.fetchcount = 0;
2556 tso->par.blocktime = 0;
2557 tso->par.blockcount = 0;
2558 tso->par.blockedat = 0;
2559 tso->par.globalsparks = 0;
2560 tso->par.localsparks = 0;
2564 globalGranStats.tot_threads_created++;
2565 globalGranStats.threads_created_on_PE[CurrentProc]++;
2566 globalGranStats.tot_sq_len += spark_queue_len(CurrentProc);
2567 globalGranStats.tot_sq_probes++;
2568 #elif defined(PARALLEL_HASKELL)
2569 // collect parallel global statistics (currently done together with GC stats)
2570 if (RtsFlags.ParFlags.ParStats.Global &&
2571 RtsFlags.GcFlags.giveStats > NO_GC_STATS) {
2572 //debugBelch("Creating thread %d @ %11.2f\n", tso->id, usertime());
2573 globalParStats.tot_threads_created++;
2579 sched_belch("==__ schedule: Created TSO %d (%p);",
2580 CurrentProc, tso, tso->id));
2581 #elif defined(PARALLEL_HASKELL)
2582 IF_PAR_DEBUG(verbose,
2583 sched_belch("==__ schedule: Created TSO %d (%p); %d threads active",
2584 (long)tso->id, tso, advisory_thread_count));
2586 IF_DEBUG(scheduler,sched_belch("created thread %ld, stack size = %lx words",
2587 (long)tso->id, (long)tso->stack_size));
2594 all parallel thread creation calls should fall through the following routine.
2597 createThreadFromSpark(rtsSpark spark)
2599 ASSERT(spark != (rtsSpark)NULL);
2600 // JB: TAKE CARE OF THIS COUNTER! BUGGY
2601 if (advisory_thread_count >= RtsFlags.ParFlags.maxThreads)
2603 barf("{createSparkThread}Daq ghuH: refusing to create another thread; no more than %d threads allowed (currently %d)",
2604 RtsFlags.ParFlags.maxThreads, advisory_thread_count);
2605 return END_TSO_QUEUE;
2609 tso = createThread(RtsFlags.GcFlags.initialStkSize);
2610 if (tso==END_TSO_QUEUE)
2611 barf("createSparkThread: Cannot create TSO");
2613 tso->priority = AdvisoryPriority;
2615 pushClosure(tso,spark);
2617 advisory_thread_count++; // JB: TAKE CARE OF THIS COUNTER! BUGGY
2624 Turn a spark into a thread.
2625 ToDo: fix for SMP (needs to acquire SCHED_MUTEX!)
2629 activateSpark (rtsSpark spark)
2633 tso = createSparkThread(spark);
2634 if (RtsFlags.ParFlags.ParStats.Full) {
2635 //ASSERT(run_queue_hd == END_TSO_QUEUE); // I think ...
2636 IF_PAR_DEBUG(verbose,
2637 debugBelch("==^^ activateSpark: turning spark of closure %p (%s) into a thread\n",
2638 (StgClosure *)spark, info_type((StgClosure *)spark)));
2640 // ToDo: fwd info on local/global spark to thread -- HWL
2641 // tso->gran.exported = spark->exported;
2642 // tso->gran.locked = !spark->global;
2643 // tso->gran.sparkname = spark->name;
2649 /* ---------------------------------------------------------------------------
2652 * scheduleThread puts a thread on the end of the runnable queue.
2653 * This will usually be done immediately after a thread is created.
2654 * The caller of scheduleThread must create the thread using e.g.
2655 * createThread and push an appropriate closure
2656 * on this thread's stack before the scheduler is invoked.
2657 * ------------------------------------------------------------------------ */
2660 scheduleThread(Capability *cap, StgTSO *tso)
2662 // The thread goes at the *end* of the run-queue, to avoid possible
2663 // starvation of any threads already on the queue.
2664 appendToRunQueue(cap,tso);
2668 scheduleWaitThread (StgTSO* tso, /*[out]*/HaskellObj* ret, Capability *cap)
2672 // We already created/initialised the Task
2673 task = cap->running_task;
2675 // This TSO is now a bound thread; make the Task and TSO
2676 // point to each other.
2681 task->stat = NoStatus;
2683 appendToRunQueue(cap,tso);
2685 IF_DEBUG(scheduler, sched_belch("new bound thread (%d)", tso->id));
2688 /* GranSim specific init */
2689 CurrentTSO = m->tso; // the TSO to run
2690 procStatus[MainProc] = Busy; // status of main PE
2691 CurrentProc = MainProc; // PE to run it on
2694 cap = schedule(cap,task);
2696 ASSERT(task->stat != NoStatus);
2697 ASSERT_FULL_CAPABILITY_INVARIANTS(cap,task);
2699 IF_DEBUG(scheduler, sched_belch("bound thread (%d) finished", task->tso->id));
2703 /* ----------------------------------------------------------------------------
2705 * ------------------------------------------------------------------------- */
2707 #if defined(THREADED_RTS)
2709 workerStart(Task *task)
2713 // See startWorkerTask().
2714 ACQUIRE_LOCK(&task->lock);
2716 RELEASE_LOCK(&task->lock);
2718 // set the thread-local pointer to the Task:
2721 // schedule() runs without a lock.
2722 cap = schedule(cap,task);
2724 // On exit from schedule(), we have a Capability.
2725 releaseCapability(cap);
2730 /* ---------------------------------------------------------------------------
2733 * Initialise the scheduler. This resets all the queues - if the
2734 * queues contained any threads, they'll be garbage collected at the
2737 * ------------------------------------------------------------------------ */
2744 for (i=0; i<=MAX_PROC; i++) {
2745 run_queue_hds[i] = END_TSO_QUEUE;
2746 run_queue_tls[i] = END_TSO_QUEUE;
2747 blocked_queue_hds[i] = END_TSO_QUEUE;
2748 blocked_queue_tls[i] = END_TSO_QUEUE;
2749 ccalling_threadss[i] = END_TSO_QUEUE;
2750 blackhole_queue[i] = END_TSO_QUEUE;
2751 sleeping_queue = END_TSO_QUEUE;
2753 #elif !defined(THREADED_RTS)
2754 blocked_queue_hd = END_TSO_QUEUE;
2755 blocked_queue_tl = END_TSO_QUEUE;
2756 sleeping_queue = END_TSO_QUEUE;
2759 blackhole_queue = END_TSO_QUEUE;
2760 all_threads = END_TSO_QUEUE;
2763 sched_state = SCHED_RUNNING;
2765 RtsFlags.ConcFlags.ctxtSwitchTicks =
2766 RtsFlags.ConcFlags.ctxtSwitchTime / TICK_MILLISECS;
2768 #if defined(THREADED_RTS)
2769 /* Initialise the mutex and condition variables used by
2771 initMutex(&sched_mutex);
2774 ACQUIRE_LOCK(&sched_mutex);
2776 /* A capability holds the state a native thread needs in
2777 * order to execute STG code. At least one capability is
2778 * floating around (only THREADED_RTS builds have more than one).
2784 #if defined(THREADED_RTS) || defined(PARALLEL_HASKELL)
2788 #if defined(THREADED_RTS)
2790 * Eagerly start one worker to run each Capability, except for
2791 * Capability 0. The idea is that we're probably going to start a
2792 * bound thread on Capability 0 pretty soon, so we don't want a
2793 * worker task hogging it.
2798 for (i = 1; i < n_capabilities; i++) {
2799 cap = &capabilities[i];
2800 ACQUIRE_LOCK(&cap->lock);
2801 startWorkerTask(cap, workerStart);
2802 RELEASE_LOCK(&cap->lock);
2807 RELEASE_LOCK(&sched_mutex);
2811 exitScheduler( void )
2815 #if defined(THREADED_RTS)
2816 ACQUIRE_LOCK(&sched_mutex);
2817 task = newBoundTask();
2818 RELEASE_LOCK(&sched_mutex);
2821 // If we haven't killed all the threads yet, do it now.
2822 if (sched_state < SCHED_INTERRUPTED) {
2823 sched_state = SCHED_INTERRUPTING;
2824 scheduleDoGC(NULL,task,rtsFalse,GetRoots);
2826 sched_state = SCHED_SHUTTING_DOWN;
2828 #if defined(THREADED_RTS)
2832 for (i = 0; i < n_capabilities; i++) {
2833 shutdownCapability(&capabilities[i], task);
2835 boundTaskExiting(task);
2841 /* ---------------------------------------------------------------------------
2842 Where are the roots that we know about?
2844 - all the threads on the runnable queue
2845 - all the threads on the blocked queue
2846 - all the threads on the sleeping queue
2847 - all the thread currently executing a _ccall_GC
2848 - all the "main threads"
2850 ------------------------------------------------------------------------ */
2852 /* This has to be protected either by the scheduler monitor, or by the
2853 garbage collection monitor (probably the latter).
2858 GetRoots( evac_fn evac )
2865 for (i=0; i<=RtsFlags.GranFlags.proc; i++) {
2866 if ((run_queue_hds[i] != END_TSO_QUEUE) && ((run_queue_hds[i] != NULL)))
2867 evac((StgClosure **)&run_queue_hds[i]);
2868 if ((run_queue_tls[i] != END_TSO_QUEUE) && ((run_queue_tls[i] != NULL)))
2869 evac((StgClosure **)&run_queue_tls[i]);
2871 if ((blocked_queue_hds[i] != END_TSO_QUEUE) && ((blocked_queue_hds[i] != NULL)))
2872 evac((StgClosure **)&blocked_queue_hds[i]);
2873 if ((blocked_queue_tls[i] != END_TSO_QUEUE) && ((blocked_queue_tls[i] != NULL)))
2874 evac((StgClosure **)&blocked_queue_tls[i]);
2875 if ((ccalling_threadss[i] != END_TSO_QUEUE) && ((ccalling_threadss[i] != NULL)))
2876 evac((StgClosure **)&ccalling_threads[i]);
2883 for (i = 0; i < n_capabilities; i++) {
2884 cap = &capabilities[i];
2885 evac((StgClosure **)&cap->run_queue_hd);
2886 evac((StgClosure **)&cap->run_queue_tl);
2888 for (task = cap->suspended_ccalling_tasks; task != NULL;
2890 evac((StgClosure **)&task->suspended_tso);
2894 #if !defined(THREADED_RTS)
2895 evac((StgClosure **)(void *)&blocked_queue_hd);
2896 evac((StgClosure **)(void *)&blocked_queue_tl);
2897 evac((StgClosure **)(void *)&sleeping_queue);
2901 // evac((StgClosure **)&blackhole_queue);
2903 #if defined(THREADED_RTS) || defined(PARALLEL_HASKELL) || defined(GRAN)
2904 markSparkQueue(evac);
2907 #if defined(RTS_USER_SIGNALS)
2908 // mark the signal handlers (signals should be already blocked)
2909 markSignalHandlers(evac);
2913 /* -----------------------------------------------------------------------------
2916 This is the interface to the garbage collector from Haskell land.
2917 We provide this so that external C code can allocate and garbage
2918 collect when called from Haskell via _ccall_GC.
2920 It might be useful to provide an interface whereby the programmer
2921 can specify more roots (ToDo).
2923 This needs to be protected by the GC condition variable above. KH.
2924 -------------------------------------------------------------------------- */
2926 static void (*extra_roots)(evac_fn);
2929 performGC_(rtsBool force_major, void (*get_roots)(evac_fn))
2931 Task *task = myTask();
2934 ACQUIRE_LOCK(&sched_mutex);
2935 task = newBoundTask();
2936 RELEASE_LOCK(&sched_mutex);
2937 scheduleDoGC(NULL,task,force_major, get_roots);
2938 boundTaskExiting(task);
2940 scheduleDoGC(NULL,task,force_major, get_roots);
2947 performGC_(rtsFalse, GetRoots);
2951 performMajorGC(void)
2953 performGC_(rtsTrue, GetRoots);
2957 AllRoots(evac_fn evac)
2959 GetRoots(evac); // the scheduler's roots
2960 extra_roots(evac); // the user's roots
2964 performGCWithRoots(void (*get_roots)(evac_fn))
2966 extra_roots = get_roots;
2967 performGC_(rtsFalse, AllRoots);
2970 /* -----------------------------------------------------------------------------
2973 If the thread has reached its maximum stack size, then raise the
2974 StackOverflow exception in the offending thread. Otherwise
2975 relocate the TSO into a larger chunk of memory and adjust its stack
2977 -------------------------------------------------------------------------- */
2980 threadStackOverflow(Capability *cap, StgTSO *tso)
2982 nat new_stack_size, stack_words;
2987 IF_DEBUG(sanity,checkTSO(tso));
2988 if (tso->stack_size >= tso->max_stack_size) {
2991 debugBelch("@@ threadStackOverflow of TSO %ld (%p): stack too large (now %ld; max is %ld)\n",
2992 (long)tso->id, tso, (long)tso->stack_size, (long)tso->max_stack_size);
2993 /* If we're debugging, just print out the top of the stack */
2994 printStackChunk(tso->sp, stg_min(tso->stack+tso->stack_size,
2997 /* Send this thread the StackOverflow exception */
2998 raiseAsync(cap, tso, (StgClosure *)stackOverflow_closure);
3002 /* Try to double the current stack size. If that takes us over the
3003 * maximum stack size for this thread, then use the maximum instead.
3004 * Finally round up so the TSO ends up as a whole number of blocks.
3006 new_stack_size = stg_min(tso->stack_size * 2, tso->max_stack_size);
3007 new_tso_size = (lnat)BLOCK_ROUND_UP(new_stack_size * sizeof(W_) +
3008 TSO_STRUCT_SIZE)/sizeof(W_);
3009 new_tso_size = round_to_mblocks(new_tso_size); /* Be MBLOCK-friendly */
3010 new_stack_size = new_tso_size - TSO_STRUCT_SIZEW;
3012 IF_DEBUG(scheduler, sched_belch("increasing stack size from %ld words to %d.\n", (long)tso->stack_size, new_stack_size));
3014 dest = (StgTSO *)allocate(new_tso_size);
3015 TICK_ALLOC_TSO(new_stack_size,0);
3017 /* copy the TSO block and the old stack into the new area */
3018 memcpy(dest,tso,TSO_STRUCT_SIZE);
3019 stack_words = tso->stack + tso->stack_size - tso->sp;
3020 new_sp = (P_)dest + new_tso_size - stack_words;
3021 memcpy(new_sp, tso->sp, stack_words * sizeof(W_));
3023 /* relocate the stack pointers... */
3025 dest->stack_size = new_stack_size;
3027 /* Mark the old TSO as relocated. We have to check for relocated
3028 * TSOs in the garbage collector and any primops that deal with TSOs.
3030 * It's important to set the sp value to just beyond the end
3031 * of the stack, so we don't attempt to scavenge any part of the
3034 tso->what_next = ThreadRelocated;
3036 tso->sp = (P_)&(tso->stack[tso->stack_size]);
3037 tso->why_blocked = NotBlocked;
3039 IF_PAR_DEBUG(verbose,
3040 debugBelch("@@ threadStackOverflow of TSO %d (now at %p): stack size increased to %ld\n",
3041 tso->id, tso, tso->stack_size);
3042 /* If we're debugging, just print out the top of the stack */
3043 printStackChunk(tso->sp, stg_min(tso->stack+tso->stack_size,
3046 IF_DEBUG(sanity,checkTSO(tso));
3048 IF_DEBUG(scheduler,printTSO(dest));
3054 /* ---------------------------------------------------------------------------
3055 Wake up a queue that was blocked on some resource.
3056 ------------------------------------------------------------------------ */
3060 unblockCount ( StgBlockingQueueElement *bqe, StgClosure *node )
3063 #elif defined(PARALLEL_HASKELL)
3065 unblockCount ( StgBlockingQueueElement *bqe, StgClosure *node )
3067 /* write RESUME events to log file and
3068 update blocked and fetch time (depending on type of the orig closure) */
3069 if (RtsFlags.ParFlags.ParStats.Full) {
3070 DumpRawGranEvent(CURRENT_PROC, CURRENT_PROC,
3071 GR_RESUMEQ, ((StgTSO *)bqe), ((StgTSO *)bqe)->block_info.closure,
3072 0, 0 /* spark_queue_len(ADVISORY_POOL) */);
3073 if (emptyRunQueue())
3074 emitSchedule = rtsTrue;
3076 switch (get_itbl(node)->type) {
3078 ((StgTSO *)bqe)->par.fetchtime += CURRENT_TIME-((StgTSO *)bqe)->par.blockedat;
3083 ((StgTSO *)bqe)->par.blocktime += CURRENT_TIME-((StgTSO *)bqe)->par.blockedat;
3090 barf("{unblockOne}Daq Qagh: unexpected closure in blocking queue");
3097 StgBlockingQueueElement *
3098 unblockOne(StgBlockingQueueElement *bqe, StgClosure *node)
3101 PEs node_loc, tso_loc;
3103 node_loc = where_is(node); // should be lifted out of loop
3104 tso = (StgTSO *)bqe; // wastes an assignment to get the type right
3105 tso_loc = where_is((StgClosure *)tso);
3106 if (IS_LOCAL_TO(PROCS(node),tso_loc)) { // TSO is local
3107 /* !fake_fetch => TSO is on CurrentProc is same as IS_LOCAL_TO */
3108 ASSERT(CurrentProc!=node_loc || tso_loc==CurrentProc);
3109 CurrentTime[CurrentProc] += RtsFlags.GranFlags.Costs.lunblocktime;
3110 // insertThread(tso, node_loc);
3111 new_event(tso_loc, tso_loc, CurrentTime[CurrentProc],
3113 tso, node, (rtsSpark*)NULL);
3114 tso->link = END_TSO_QUEUE; // overwrite link just to be sure
3117 } else { // TSO is remote (actually should be FMBQ)
3118 CurrentTime[CurrentProc] += RtsFlags.GranFlags.Costs.mpacktime +
3119 RtsFlags.GranFlags.Costs.gunblocktime +
3120 RtsFlags.GranFlags.Costs.latency;
3121 new_event(tso_loc, CurrentProc, CurrentTime[CurrentProc],
3123 tso, node, (rtsSpark*)NULL);
3124 tso->link = END_TSO_QUEUE; // overwrite link just to be sure
3127 /* the thread-queue-overhead is accounted for in either Resume or UnblockThread */
3129 debugBelch(" %s TSO %d (%p) [PE %d] (block_info.closure=%p) (next=%p) ,",
3130 (node_loc==tso_loc ? "Local" : "Global"),
3131 tso->id, tso, CurrentProc, tso->block_info.closure, tso->link));
3132 tso->block_info.closure = NULL;
3133 IF_DEBUG(scheduler,debugBelch("-- Waking up thread %ld (%p)\n",
3136 #elif defined(PARALLEL_HASKELL)
3137 StgBlockingQueueElement *
3138 unblockOne(StgBlockingQueueElement *bqe, StgClosure *node)
3140 StgBlockingQueueElement *next;
3142 switch (get_itbl(bqe)->type) {
3144 ASSERT(((StgTSO *)bqe)->why_blocked != NotBlocked);
3145 /* if it's a TSO just push it onto the run_queue */
3147 ((StgTSO *)bqe)->link = END_TSO_QUEUE; // debugging?
3148 APPEND_TO_RUN_QUEUE((StgTSO *)bqe);
3150 unblockCount(bqe, node);
3151 /* reset blocking status after dumping event */
3152 ((StgTSO *)bqe)->why_blocked = NotBlocked;
3156 /* if it's a BLOCKED_FETCH put it on the PendingFetches list */
3158 bqe->link = (StgBlockingQueueElement *)PendingFetches;
3159 PendingFetches = (StgBlockedFetch *)bqe;
3163 /* can ignore this case in a non-debugging setup;
3164 see comments on RBHSave closures above */
3166 /* check that the closure is an RBHSave closure */
3167 ASSERT(get_itbl((StgClosure *)bqe) == &stg_RBH_Save_0_info ||
3168 get_itbl((StgClosure *)bqe) == &stg_RBH_Save_1_info ||
3169 get_itbl((StgClosure *)bqe) == &stg_RBH_Save_2_info);
3173 barf("{unblockOne}Daq Qagh: Unexpected IP (%#lx; %s) in blocking queue at %#lx\n",
3174 get_itbl((StgClosure *)bqe), info_type((StgClosure *)bqe),
3178 IF_PAR_DEBUG(bq, debugBelch(", %p (%s)\n", bqe, info_type((StgClosure*)bqe)));
3184 unblockOne(Capability *cap, StgTSO *tso)
3188 ASSERT(get_itbl(tso)->type == TSO);
3189 ASSERT(tso->why_blocked != NotBlocked);
3190 tso->why_blocked = NotBlocked;
3192 tso->link = END_TSO_QUEUE;
3194 // We might have just migrated this TSO to our Capability:
3196 tso->bound->cap = cap;
3199 appendToRunQueue(cap,tso);
3201 // we're holding a newly woken thread, make sure we context switch
3202 // quickly so we can migrate it if necessary.
3204 IF_DEBUG(scheduler,sched_belch("waking up thread %ld", (long)tso->id));
3211 awakenBlockedQueue(StgBlockingQueueElement *q, StgClosure *node)
3213 StgBlockingQueueElement *bqe;
3218 debugBelch("##-_ AwBQ for node %p on PE %d @ %ld by TSO %d (%p): \n", \
3219 node, CurrentProc, CurrentTime[CurrentProc],
3220 CurrentTSO->id, CurrentTSO));
3222 node_loc = where_is(node);
3224 ASSERT(q == END_BQ_QUEUE ||
3225 get_itbl(q)->type == TSO || // q is either a TSO or an RBHSave
3226 get_itbl(q)->type == CONSTR); // closure (type constructor)
3227 ASSERT(is_unique(node));
3229 /* FAKE FETCH: magically copy the node to the tso's proc;
3230 no Fetch necessary because in reality the node should not have been
3231 moved to the other PE in the first place
3233 if (CurrentProc!=node_loc) {
3235 debugBelch("## node %p is on PE %d but CurrentProc is %d (TSO %d); assuming fake fetch and adjusting bitmask (old: %#x)\n",
3236 node, node_loc, CurrentProc, CurrentTSO->id,
3237 // CurrentTSO, where_is(CurrentTSO),
3238 node->header.gran.procs));
3239 node->header.gran.procs = (node->header.gran.procs) | PE_NUMBER(CurrentProc);
3241 debugBelch("## new bitmask of node %p is %#x\n",
3242 node, node->header.gran.procs));
3243 if (RtsFlags.GranFlags.GranSimStats.Global) {
3244 globalGranStats.tot_fake_fetches++;
3249 // ToDo: check: ASSERT(CurrentProc==node_loc);
3250 while (get_itbl(bqe)->type==TSO) { // q != END_TSO_QUEUE) {
3253 bqe points to the current element in the queue
3254 next points to the next element in the queue
3256 //tso = (StgTSO *)bqe; // wastes an assignment to get the type right
3257 //tso_loc = where_is(tso);
3259 bqe = unblockOne(bqe, node);
3262 /* if this is the BQ of an RBH, we have to put back the info ripped out of
3263 the closure to make room for the anchor of the BQ */
3264 if (bqe!=END_BQ_QUEUE) {
3265 ASSERT(get_itbl(node)->type == RBH && get_itbl(bqe)->type == CONSTR);
3267 ASSERT((info_ptr==&RBH_Save_0_info) ||
3268 (info_ptr==&RBH_Save_1_info) ||
3269 (info_ptr==&RBH_Save_2_info));
3271 /* cf. convertToRBH in RBH.c for writing the RBHSave closure */
3272 ((StgRBH *)node)->blocking_queue = (StgBlockingQueueElement *)((StgRBHSave *)bqe)->payload[0];
3273 ((StgRBH *)node)->mut_link = (StgMutClosure *)((StgRBHSave *)bqe)->payload[1];
3276 debugBelch("## Filled in RBH_Save for %p (%s) at end of AwBQ\n",
3277 node, info_type(node)));
3280 /* statistics gathering */
3281 if (RtsFlags.GranFlags.GranSimStats.Global) {
3282 // globalGranStats.tot_bq_processing_time += bq_processing_time;
3283 globalGranStats.tot_bq_len += len; // total length of all bqs awakened
3284 // globalGranStats.tot_bq_len_local += len_local; // same for local TSOs only
3285 globalGranStats.tot_awbq++; // total no. of bqs awakened
3288 debugBelch("## BQ Stats of %p: [%d entries] %s\n",
3289 node, len, (bqe!=END_BQ_QUEUE) ? "RBH" : ""));
3291 #elif defined(PARALLEL_HASKELL)
3293 awakenBlockedQueue(StgBlockingQueueElement *q, StgClosure *node)
3295 StgBlockingQueueElement *bqe;
3297 IF_PAR_DEBUG(verbose,
3298 debugBelch("##-_ AwBQ for node %p on [%x]: \n",
3302 if(get_itbl(q)->type == CONSTR || q==END_BQ_QUEUE) {
3303 IF_PAR_DEBUG(verbose, debugBelch("## ... nothing to unblock so lets just return. RFP (BUG?)\n"));
3308 ASSERT(q == END_BQ_QUEUE ||
3309 get_itbl(q)->type == TSO ||
3310 get_itbl(q)->type == BLOCKED_FETCH ||
3311 get_itbl(q)->type == CONSTR);
3314 while (get_itbl(bqe)->type==TSO ||
3315 get_itbl(bqe)->type==BLOCKED_FETCH) {
3316 bqe = unblockOne(bqe, node);
3320 #else /* !GRAN && !PARALLEL_HASKELL */
3323 awakenBlockedQueue(Capability *cap, StgTSO *tso)
3325 if (tso == NULL) return; // hack; see bug #1235728, and comments in
3327 while (tso != END_TSO_QUEUE) {
3328 tso = unblockOne(cap,tso);
3333 /* ---------------------------------------------------------------------------
3335 - usually called inside a signal handler so it mustn't do anything fancy.
3336 ------------------------------------------------------------------------ */
3339 interruptStgRts(void)
3341 sched_state = SCHED_INTERRUPTING;
3343 #if defined(THREADED_RTS)
3344 prodAllCapabilities();
3348 /* -----------------------------------------------------------------------------
3351 This is for use when we raise an exception in another thread, which
3353 This has nothing to do with the UnblockThread event in GranSim. -- HWL
3354 -------------------------------------------------------------------------- */
3356 #if defined(GRAN) || defined(PARALLEL_HASKELL)
3358 NB: only the type of the blocking queue is different in GranSim and GUM
3359 the operations on the queue-elements are the same
3360 long live polymorphism!
3362 Locks: sched_mutex is held upon entry and exit.
3366 unblockThread(Capability *cap, StgTSO *tso)
3368 StgBlockingQueueElement *t, **last;
3370 switch (tso->why_blocked) {
3373 return; /* not blocked */
3376 // Be careful: nothing to do here! We tell the scheduler that the thread
3377 // is runnable and we leave it to the stack-walking code to abort the
3378 // transaction while unwinding the stack. We should perhaps have a debugging
3379 // test to make sure that this really happens and that the 'zombie' transaction
3380 // does not get committed.
3384 ASSERT(get_itbl(tso->block_info.closure)->type == MVAR);
3386 StgBlockingQueueElement *last_tso = END_BQ_QUEUE;
3387 StgMVar *mvar = (StgMVar *)(tso->block_info.closure);
3389 last = (StgBlockingQueueElement **)&mvar->head;
3390 for (t = (StgBlockingQueueElement *)mvar->head;
3392 last = &t->link, last_tso = t, t = t->link) {
3393 if (t == (StgBlockingQueueElement *)tso) {
3394 *last = (StgBlockingQueueElement *)tso->link;
3395 if (mvar->tail == tso) {
3396 mvar->tail = (StgTSO *)last_tso;
3401 barf("unblockThread (MVAR): TSO not found");
3404 case BlockedOnBlackHole:
3405 ASSERT(get_itbl(tso->block_info.closure)->type == BLACKHOLE_BQ);
3407 StgBlockingQueue *bq = (StgBlockingQueue *)(tso->block_info.closure);
3409 last = &bq->blocking_queue;
3410 for (t = bq->blocking_queue;
3412 last = &t->link, t = t->link) {
3413 if (t == (StgBlockingQueueElement *)tso) {
3414 *last = (StgBlockingQueueElement *)tso->link;
3418 barf("unblockThread (BLACKHOLE): TSO not found");
3421 case BlockedOnException:
3423 StgTSO *target = tso->block_info.tso;
3425 ASSERT(get_itbl(target)->type == TSO);
3427 if (target->what_next == ThreadRelocated) {
3428 target = target->link;
3429 ASSERT(get_itbl(target)->type == TSO);
3432 ASSERT(target->blocked_exceptions != NULL);
3434 last = (StgBlockingQueueElement **)&target->blocked_exceptions;
3435 for (t = (StgBlockingQueueElement *)target->blocked_exceptions;
3437 last = &t->link, t = t->link) {
3438 ASSERT(get_itbl(t)->type == TSO);
3439 if (t == (StgBlockingQueueElement *)tso) {
3440 *last = (StgBlockingQueueElement *)tso->link;
3444 barf("unblockThread (Exception): TSO not found");
3448 case BlockedOnWrite:
3449 #if defined(mingw32_HOST_OS)
3450 case BlockedOnDoProc:
3453 /* take TSO off blocked_queue */
3454 StgBlockingQueueElement *prev = NULL;
3455 for (t = (StgBlockingQueueElement *)blocked_queue_hd; t != END_BQ_QUEUE;
3456 prev = t, t = t->link) {
3457 if (t == (StgBlockingQueueElement *)tso) {
3459 blocked_queue_hd = (StgTSO *)t->link;
3460 if ((StgBlockingQueueElement *)blocked_queue_tl == t) {
3461 blocked_queue_tl = END_TSO_QUEUE;
3464 prev->link = t->link;
3465 if ((StgBlockingQueueElement *)blocked_queue_tl == t) {
3466 blocked_queue_tl = (StgTSO *)prev;
3469 #if defined(mingw32_HOST_OS)
3470 /* (Cooperatively) signal that the worker thread should abort
3473 abandonWorkRequest(tso->block_info.async_result->reqID);
3478 barf("unblockThread (I/O): TSO not found");
3481 case BlockedOnDelay:
3483 /* take TSO off sleeping_queue */
3484 StgBlockingQueueElement *prev = NULL;
3485 for (t = (StgBlockingQueueElement *)sleeping_queue; t != END_BQ_QUEUE;
3486 prev = t, t = t->link) {
3487 if (t == (StgBlockingQueueElement *)tso) {
3489 sleeping_queue = (StgTSO *)t->link;
3491 prev->link = t->link;
3496 barf("unblockThread (delay): TSO not found");
3500 barf("unblockThread");
3504 tso->link = END_TSO_QUEUE;
3505 tso->why_blocked = NotBlocked;
3506 tso->block_info.closure = NULL;
3507 pushOnRunQueue(cap,tso);
3511 unblockThread(Capability *cap, StgTSO *tso)
3515 /* To avoid locking unnecessarily. */
3516 if (tso->why_blocked == NotBlocked) {
3520 switch (tso->why_blocked) {
3523 // Be careful: nothing to do here! We tell the scheduler that the thread
3524 // is runnable and we leave it to the stack-walking code to abort the
3525 // transaction while unwinding the stack. We should perhaps have a debugging
3526 // test to make sure that this really happens and that the 'zombie' transaction
3527 // does not get committed.
3531 ASSERT(get_itbl(tso->block_info.closure)->type == MVAR);
3533 StgTSO *last_tso = END_TSO_QUEUE;
3534 StgMVar *mvar = (StgMVar *)(tso->block_info.closure);
3537 for (t = mvar->head; t != END_TSO_QUEUE;
3538 last = &t->link, last_tso = t, t = t->link) {
3541 if (mvar->tail == tso) {
3542 mvar->tail = last_tso;
3547 barf("unblockThread (MVAR): TSO not found");
3550 case BlockedOnBlackHole:
3552 last = &blackhole_queue;
3553 for (t = blackhole_queue; t != END_TSO_QUEUE;
3554 last = &t->link, t = t->link) {
3560 barf("unblockThread (BLACKHOLE): TSO not found");
3563 case BlockedOnException:
3565 StgTSO *target = tso->block_info.tso;
3567 ASSERT(get_itbl(target)->type == TSO);
3569 while (target->what_next == ThreadRelocated) {
3570 target = target->link;
3571 ASSERT(get_itbl(target)->type == TSO);
3574 ASSERT(target->blocked_exceptions != NULL);
3576 last = &target->blocked_exceptions;
3577 for (t = target->blocked_exceptions; t != END_TSO_QUEUE;
3578 last = &t->link, t = t->link) {
3579 ASSERT(get_itbl(t)->type == TSO);
3585 barf("unblockThread (Exception): TSO not found");
3588 #if !defined(THREADED_RTS)
3590 case BlockedOnWrite:
3591 #if defined(mingw32_HOST_OS)
3592 case BlockedOnDoProc:
3595 StgTSO *prev = NULL;
3596 for (t = blocked_queue_hd; t != END_TSO_QUEUE;
3597 prev = t, t = t->link) {
3600 blocked_queue_hd = t->link;
3601 if (blocked_queue_tl == t) {
3602 blocked_queue_tl = END_TSO_QUEUE;
3605 prev->link = t->link;
3606 if (blocked_queue_tl == t) {
3607 blocked_queue_tl = prev;
3610 #if defined(mingw32_HOST_OS)
3611 /* (Cooperatively) signal that the worker thread should abort
3614 abandonWorkRequest(tso->block_info.async_result->reqID);
3619 barf("unblockThread (I/O): TSO not found");
3622 case BlockedOnDelay:
3624 StgTSO *prev = NULL;
3625 for (t = sleeping_queue; t != END_TSO_QUEUE;
3626 prev = t, t = t->link) {
3629 sleeping_queue = t->link;
3631 prev->link = t->link;
3636 barf("unblockThread (delay): TSO not found");
3641 barf("unblockThread");
3645 tso->link = END_TSO_QUEUE;
3646 tso->why_blocked = NotBlocked;
3647 tso->block_info.closure = NULL;
3648 appendToRunQueue(cap,tso);
3650 // We might have just migrated this TSO to our Capability:
3652 tso->bound->cap = cap;
3657 /* -----------------------------------------------------------------------------
3660 * Check the blackhole_queue for threads that can be woken up. We do
3661 * this periodically: before every GC, and whenever the run queue is
3664 * An elegant solution might be to just wake up all the blocked
3665 * threads with awakenBlockedQueue occasionally: they'll go back to
3666 * sleep again if the object is still a BLACKHOLE. Unfortunately this
3667 * doesn't give us a way to tell whether we've actually managed to
3668 * wake up any threads, so we would be busy-waiting.
3670 * -------------------------------------------------------------------------- */
3673 checkBlackHoles (Capability *cap)
3676 rtsBool any_woke_up = rtsFalse;
3679 // blackhole_queue is global:
3680 ASSERT_LOCK_HELD(&sched_mutex);
3682 IF_DEBUG(scheduler, sched_belch("checking threads blocked on black holes"));
3684 // ASSUMES: sched_mutex
3685 prev = &blackhole_queue;
3686 t = blackhole_queue;
3687 while (t != END_TSO_QUEUE) {
3688 ASSERT(t->why_blocked == BlockedOnBlackHole);
3689 type = get_itbl(t->block_info.closure)->type;
3690 if (type != BLACKHOLE && type != CAF_BLACKHOLE) {
3691 IF_DEBUG(sanity,checkTSO(t));
3692 t = unblockOne(cap, t);
3693 // urk, the threads migrate to the current capability
3694 // here, but we'd like to keep them on the original one.
3696 any_woke_up = rtsTrue;
3706 /* -----------------------------------------------------------------------------
3709 * The following function implements the magic for raising an
3710 * asynchronous exception in an existing thread.
3712 * We first remove the thread from any queue on which it might be
3713 * blocked. The possible blockages are MVARs and BLACKHOLE_BQs.
3715 * We strip the stack down to the innermost CATCH_FRAME, building
3716 * thunks in the heap for all the active computations, so they can
3717 * be restarted if necessary. When we reach a CATCH_FRAME, we build
3718 * an application of the handler to the exception, and push it on
3719 * the top of the stack.
3721 * How exactly do we save all the active computations? We create an
3722 * AP_STACK for every UpdateFrame on the stack. Entering one of these
3723 * AP_STACKs pushes everything from the corresponding update frame
3724 * upwards onto the stack. (Actually, it pushes everything up to the
3725 * next update frame plus a pointer to the next AP_STACK object.
3726 * Entering the next AP_STACK object pushes more onto the stack until we
3727 * reach the last AP_STACK object - at which point the stack should look
3728 * exactly as it did when we killed the TSO and we can continue
3729 * execution by entering the closure on top of the stack.
3731 * We can also kill a thread entirely - this happens if either (a) the
3732 * exception passed to raiseAsync is NULL, or (b) there's no
3733 * CATCH_FRAME on the stack. In either case, we strip the entire
3734 * stack and replace the thread with a zombie.
3736 * ToDo: in THREADED_RTS mode, this function is only safe if either
3737 * (a) we hold all the Capabilities (eg. in GC, or if there is only
3738 * one Capability), or (b) we own the Capability that the TSO is
3739 * currently blocked on or on the run queue of.
3741 * -------------------------------------------------------------------------- */
3744 raiseAsync(Capability *cap, StgTSO *tso, StgClosure *exception)
3746 raiseAsync_(cap, tso, exception, rtsFalse, NULL);
3750 suspendComputation(Capability *cap, StgTSO *tso, StgPtr stop_here)
3752 raiseAsync_(cap, tso, NULL, rtsFalse, stop_here);
3756 raiseAsync_(Capability *cap, StgTSO *tso, StgClosure *exception,
3757 rtsBool stop_at_atomically, StgPtr stop_here)
3759 StgRetInfoTable *info;
3763 // Thread already dead?
3764 if (tso->what_next == ThreadComplete || tso->what_next == ThreadKilled) {
3769 sched_belch("raising exception in thread %ld.", (long)tso->id));
3771 // Remove it from any blocking queues
3772 unblockThread(cap,tso);
3774 // mark it dirty; we're about to change its stack.
3779 // The stack freezing code assumes there's a closure pointer on
3780 // the top of the stack, so we have to arrange that this is the case...
3782 if (sp[0] == (W_)&stg_enter_info) {
3786 sp[0] = (W_)&stg_dummy_ret_closure;
3790 while (stop_here == NULL || frame < stop_here) {
3792 // 1. Let the top of the stack be the "current closure"
3794 // 2. Walk up the stack until we find either an UPDATE_FRAME or a
3797 // 3. If it's an UPDATE_FRAME, then make an AP_STACK containing the
3798 // current closure applied to the chunk of stack up to (but not
3799 // including) the update frame. This closure becomes the "current
3800 // closure". Go back to step 2.
3802 // 4. If it's a CATCH_FRAME, then leave the exception handler on
3803 // top of the stack applied to the exception.
3805 // 5. If it's a STOP_FRAME, then kill the thread.
3807 // NB: if we pass an ATOMICALLY_FRAME then abort the associated
3810 info = get_ret_itbl((StgClosure *)frame);
3812 switch (info->i.type) {
3819 // First build an AP_STACK consisting of the stack chunk above the
3820 // current update frame, with the top word on the stack as the
3823 words = frame - sp - 1;
3824 ap = (StgAP_STACK *)allocateLocal(cap,AP_STACK_sizeW(words));
3827 ap->fun = (StgClosure *)sp[0];
3829 for(i=0; i < (nat)words; ++i) {
3830 ap->payload[i] = (StgClosure *)*sp++;
3833 SET_HDR(ap,&stg_AP_STACK_info,
3834 ((StgClosure *)frame)->header.prof.ccs /* ToDo */);
3835 TICK_ALLOC_UP_THK(words+1,0);
3838 debugBelch("sched: Updating ");
3839 printPtr((P_)((StgUpdateFrame *)frame)->updatee);
3840 debugBelch(" with ");
3841 printObj((StgClosure *)ap);
3844 // Replace the updatee with an indirection
3846 // Warning: if we're in a loop, more than one update frame on
3847 // the stack may point to the same object. Be careful not to
3848 // overwrite an IND_OLDGEN in this case, because we'll screw
3849 // up the mutable lists. To be on the safe side, don't
3850 // overwrite any kind of indirection at all. See also
3851 // threadSqueezeStack in GC.c, where we have to make a similar
3854 if (!closure_IND(((StgUpdateFrame *)frame)->updatee)) {
3855 // revert the black hole
3856 UPD_IND_NOLOCK(((StgUpdateFrame *)frame)->updatee,
3859 sp += sizeofW(StgUpdateFrame) - 1;
3860 sp[0] = (W_)ap; // push onto stack
3862 continue; //no need to bump frame
3866 // We've stripped the entire stack, the thread is now dead.
3867 tso->what_next = ThreadKilled;
3868 tso->sp = frame + sizeofW(StgStopFrame);
3872 // If we find a CATCH_FRAME, and we've got an exception to raise,
3873 // then build the THUNK raise(exception), and leave it on
3874 // top of the CATCH_FRAME ready to enter.
3878 StgCatchFrame *cf = (StgCatchFrame *)frame;
3882 if (exception == NULL) break;
3884 // we've got an exception to raise, so let's pass it to the
3885 // handler in this frame.
3887 raise = (StgThunk *)allocateLocal(cap,sizeofW(StgThunk)+1);
3888 TICK_ALLOC_SE_THK(1,0);
3889 SET_HDR(raise,&stg_raise_info,cf->header.prof.ccs);
3890 raise->payload[0] = exception;
3892 // throw away the stack from Sp up to the CATCH_FRAME.
3896 /* Ensure that async excpetions are blocked now, so we don't get
3897 * a surprise exception before we get around to executing the
3900 if (tso->blocked_exceptions == NULL) {
3901 tso->blocked_exceptions = END_TSO_QUEUE;
3904 /* Put the newly-built THUNK on top of the stack, ready to execute
3905 * when the thread restarts.
3908 sp[-1] = (W_)&stg_enter_info;
3910 tso->what_next = ThreadRunGHC;
3911 IF_DEBUG(sanity, checkTSO(tso));
3915 case ATOMICALLY_FRAME:
3916 if (stop_at_atomically) {
3917 ASSERT(stmGetEnclosingTRec(tso->trec) == NO_TREC);
3918 stmCondemnTransaction(cap, tso -> trec);
3922 // R1 is not a register: the return convention for IO in
3923 // this case puts the return value on the stack, so we
3924 // need to set up the stack to return to the atomically
3925 // frame properly...
3926 tso->sp = frame - 2;
3927 tso->sp[1] = (StgWord) &stg_NO_FINALIZER_closure; // why not?
3928 tso->sp[0] = (StgWord) &stg_ut_1_0_unreg_info;
3930 tso->what_next = ThreadRunGHC;
3933 // Not stop_at_atomically... fall through and abort the
3936 case CATCH_RETRY_FRAME:
3937 // IF we find an ATOMICALLY_FRAME then we abort the
3938 // current transaction and propagate the exception. In
3939 // this case (unlike ordinary exceptions) we do not care
3940 // whether the transaction is valid or not because its
3941 // possible validity cannot have caused the exception
3942 // and will not be visible after the abort.
3944 debugBelch("Found atomically block delivering async exception\n"));
3945 StgTRecHeader *trec = tso -> trec;
3946 StgTRecHeader *outer = stmGetEnclosingTRec(trec);
3947 stmAbortTransaction(cap, trec);
3948 tso -> trec = outer;
3955 // move on to the next stack frame
3956 frame += stack_frame_sizeW((StgClosure *)frame);
3959 // if we got here, then we stopped at stop_here
3960 ASSERT(stop_here != NULL);
3963 /* -----------------------------------------------------------------------------
3966 This is used for interruption (^C) and forking, and corresponds to
3967 raising an exception but without letting the thread catch the
3969 -------------------------------------------------------------------------- */
3972 deleteThread (Capability *cap, StgTSO *tso)
3974 if (tso->why_blocked != BlockedOnCCall &&
3975 tso->why_blocked != BlockedOnCCall_NoUnblockExc) {
3976 raiseAsync(cap,tso,NULL);
3980 #ifdef FORKPROCESS_PRIMOP_SUPPORTED
3982 deleteThreadImmediately(Capability *cap, StgTSO *tso)
3983 { // for forkProcess only:
3984 // delete thread without giving it a chance to catch the KillThread exception
3986 if (tso->what_next == ThreadComplete || tso->what_next == ThreadKilled) {
3990 if (tso->why_blocked != BlockedOnCCall &&
3991 tso->why_blocked != BlockedOnCCall_NoUnblockExc) {
3992 unblockThread(cap,tso);
3995 tso->what_next = ThreadKilled;
3999 /* -----------------------------------------------------------------------------
4000 raiseExceptionHelper
4002 This function is called by the raise# primitve, just so that we can
4003 move some of the tricky bits of raising an exception from C-- into
4004 C. Who knows, it might be a useful re-useable thing here too.
4005 -------------------------------------------------------------------------- */
4008 raiseExceptionHelper (StgRegTable *reg, StgTSO *tso, StgClosure *exception)
4010 Capability *cap = regTableToCapability(reg);
4011 StgThunk *raise_closure = NULL;
4013 StgRetInfoTable *info;
4015 // This closure represents the expression 'raise# E' where E
4016 // is the exception raise. It is used to overwrite all the
4017 // thunks which are currently under evaluataion.
4020 // OLD COMMENT (we don't have MIN_UPD_SIZE now):
4021 // LDV profiling: stg_raise_info has THUNK as its closure
4022 // type. Since a THUNK takes at least MIN_UPD_SIZE words in its
4023 // payload, MIN_UPD_SIZE is more approprate than 1. It seems that
4024 // 1 does not cause any problem unless profiling is performed.
4025 // However, when LDV profiling goes on, we need to linearly scan
4026 // small object pool, where raise_closure is stored, so we should
4027 // use MIN_UPD_SIZE.
4029 // raise_closure = (StgClosure *)RET_STGCALL1(P_,allocate,
4030 // sizeofW(StgClosure)+1);
4034 // Walk up the stack, looking for the catch frame. On the way,
4035 // we update any closures pointed to from update frames with the
4036 // raise closure that we just built.
4040 info = get_ret_itbl((StgClosure *)p);
4041 next = p + stack_frame_sizeW((StgClosure *)p);
4042 switch (info->i.type) {
4045 // Only create raise_closure if we need to.
4046 if (raise_closure == NULL) {
4048 (StgThunk *)allocateLocal(cap,sizeofW(StgThunk)+1);
4049 SET_HDR(raise_closure, &stg_raise_info, CCCS);
4050 raise_closure->payload[0] = exception;
4052 UPD_IND(((StgUpdateFrame *)p)->updatee,(StgClosure *)raise_closure);
4056 case ATOMICALLY_FRAME:
4057 IF_DEBUG(stm, debugBelch("Found ATOMICALLY_FRAME at %p\n", p));
4059 return ATOMICALLY_FRAME;
4065 case CATCH_STM_FRAME:
4066 IF_DEBUG(stm, debugBelch("Found CATCH_STM_FRAME at %p\n", p));
4068 return CATCH_STM_FRAME;
4074 case CATCH_RETRY_FRAME:
4083 /* -----------------------------------------------------------------------------
4084 findRetryFrameHelper
4086 This function is called by the retry# primitive. It traverses the stack
4087 leaving tso->sp referring to the frame which should handle the retry.
4089 This should either be a CATCH_RETRY_FRAME (if the retry# is within an orElse#)
4090 or should be a ATOMICALLY_FRAME (if the retry# reaches the top level).
4092 We skip CATCH_STM_FRAMEs because retries are not considered to be exceptions,
4093 despite the similar implementation.
4095 We should not expect to see CATCH_FRAME or STOP_FRAME because those should
4096 not be created within memory transactions.
4097 -------------------------------------------------------------------------- */
4100 findRetryFrameHelper (StgTSO *tso)
4103 StgRetInfoTable *info;
4107 info = get_ret_itbl((StgClosure *)p);
4108 next = p + stack_frame_sizeW((StgClosure *)p);
4109 switch (info->i.type) {
4111 case ATOMICALLY_FRAME:
4112 IF_DEBUG(stm, debugBelch("Found ATOMICALLY_FRAME at %p during retrry\n", p));
4114 return ATOMICALLY_FRAME;
4116 case CATCH_RETRY_FRAME:
4117 IF_DEBUG(stm, debugBelch("Found CATCH_RETRY_FRAME at %p during retrry\n", p));
4119 return CATCH_RETRY_FRAME;
4121 case CATCH_STM_FRAME:
4123 ASSERT(info->i.type != CATCH_FRAME);
4124 ASSERT(info->i.type != STOP_FRAME);
4131 /* -----------------------------------------------------------------------------
4132 resurrectThreads is called after garbage collection on the list of
4133 threads found to be garbage. Each of these threads will be woken
4134 up and sent a signal: BlockedOnDeadMVar if the thread was blocked
4135 on an MVar, or NonTermination if the thread was blocked on a Black
4138 Locks: assumes we hold *all* the capabilities.
4139 -------------------------------------------------------------------------- */
4142 resurrectThreads (StgTSO *threads)
4147 for (tso = threads; tso != END_TSO_QUEUE; tso = next) {
4148 next = tso->global_link;
4149 tso->global_link = all_threads;
4151 IF_DEBUG(scheduler, sched_belch("resurrecting thread %d", tso->id));
4153 // Wake up the thread on the Capability it was last on for a
4154 // bound thread, or last_free_capability otherwise.
4156 cap = tso->bound->cap;
4158 cap = last_free_capability;
4161 switch (tso->why_blocked) {
4163 case BlockedOnException:
4164 /* Called by GC - sched_mutex lock is currently held. */
4165 raiseAsync(cap, tso,(StgClosure *)BlockedOnDeadMVar_closure);
4167 case BlockedOnBlackHole:
4168 raiseAsync(cap, tso,(StgClosure *)NonTermination_closure);
4171 raiseAsync(cap, tso,(StgClosure *)BlockedIndefinitely_closure);
4174 /* This might happen if the thread was blocked on a black hole
4175 * belonging to a thread that we've just woken up (raiseAsync
4176 * can wake up threads, remember...).
4180 barf("resurrectThreads: thread blocked in a strange way");
4185 /* ----------------------------------------------------------------------------
4186 * Debugging: why is a thread blocked
4187 * [Also provides useful information when debugging threaded programs
4188 * at the Haskell source code level, so enable outside of DEBUG. --sof 7/02]
4189 ------------------------------------------------------------------------- */
4193 printThreadBlockage(StgTSO *tso)
4195 switch (tso->why_blocked) {
4197 debugBelch("is blocked on read from fd %d", (int)(tso->block_info.fd));
4199 case BlockedOnWrite:
4200 debugBelch("is blocked on write to fd %d", (int)(tso->block_info.fd));
4202 #if defined(mingw32_HOST_OS)
4203 case BlockedOnDoProc:
4204 debugBelch("is blocked on proc (request: %ld)", tso->block_info.async_result->reqID);
4207 case BlockedOnDelay:
4208 debugBelch("is blocked until %ld", (long)(tso->block_info.target));
4211 debugBelch("is blocked on an MVar @ %p", tso->block_info.closure);
4213 case BlockedOnException:
4214 debugBelch("is blocked on delivering an exception to thread %d",
4215 tso->block_info.tso->id);
4217 case BlockedOnBlackHole:
4218 debugBelch("is blocked on a black hole");
4221 debugBelch("is not blocked");
4223 #if defined(PARALLEL_HASKELL)
4225 debugBelch("is blocked on global address; local FM_BQ is %p (%s)",
4226 tso->block_info.closure, info_type(tso->block_info.closure));
4228 case BlockedOnGA_NoSend:
4229 debugBelch("is blocked on global address (no send); local FM_BQ is %p (%s)",
4230 tso->block_info.closure, info_type(tso->block_info.closure));
4233 case BlockedOnCCall:
4234 debugBelch("is blocked on an external call");
4236 case BlockedOnCCall_NoUnblockExc:
4237 debugBelch("is blocked on an external call (exceptions were already blocked)");
4240 debugBelch("is blocked on an STM operation");
4243 barf("printThreadBlockage: strange tso->why_blocked: %d for TSO %d (%d)",
4244 tso->why_blocked, tso->id, tso);
4249 printThreadStatus(StgTSO *t)
4251 debugBelch("\tthread %4d @ %p ", t->id, (void *)t);
4253 void *label = lookupThreadLabel(t->id);
4254 if (label) debugBelch("[\"%s\"] ",(char *)label);
4256 if (t->what_next == ThreadRelocated) {
4257 debugBelch("has been relocated...\n");
4259 switch (t->what_next) {
4261 debugBelch("has been killed");
4263 case ThreadComplete:
4264 debugBelch("has completed");
4267 printThreadBlockage(t);
4274 printAllThreads(void)
4281 char time_string[TIME_STR_LEN], node_str[NODE_STR_LEN];
4282 ullong_format_string(TIME_ON_PROC(CurrentProc),
4283 time_string, rtsFalse/*no commas!*/);
4285 debugBelch("all threads at [%s]:\n", time_string);
4286 # elif defined(PARALLEL_HASKELL)
4287 char time_string[TIME_STR_LEN], node_str[NODE_STR_LEN];
4288 ullong_format_string(CURRENT_TIME,
4289 time_string, rtsFalse/*no commas!*/);
4291 debugBelch("all threads at [%s]:\n", time_string);
4293 debugBelch("all threads:\n");
4296 for (i = 0; i < n_capabilities; i++) {
4297 cap = &capabilities[i];
4298 debugBelch("threads on capability %d:\n", cap->no);
4299 for (t = cap->run_queue_hd; t != END_TSO_QUEUE; t = t->link) {
4300 printThreadStatus(t);
4304 debugBelch("other threads:\n");
4305 for (t = all_threads; t != END_TSO_QUEUE; t = next) {
4306 if (t->why_blocked != NotBlocked) {
4307 printThreadStatus(t);
4309 if (t->what_next == ThreadRelocated) {
4312 next = t->global_link;
4319 printThreadQueue(StgTSO *t)
4322 for (; t != END_TSO_QUEUE; t = t->link) {
4323 printThreadStatus(t);
4326 debugBelch("%d threads on queue\n", i);
4330 Print a whole blocking queue attached to node (debugging only).
4332 # if defined(PARALLEL_HASKELL)
4334 print_bq (StgClosure *node)
4336 StgBlockingQueueElement *bqe;
4340 debugBelch("## BQ of closure %p (%s): ",
4341 node, info_type(node));
4343 /* should cover all closures that may have a blocking queue */
4344 ASSERT(get_itbl(node)->type == BLACKHOLE_BQ ||
4345 get_itbl(node)->type == FETCH_ME_BQ ||
4346 get_itbl(node)->type == RBH ||
4347 get_itbl(node)->type == MVAR);
4349 ASSERT(node!=(StgClosure*)NULL); // sanity check
4351 print_bqe(((StgBlockingQueue*)node)->blocking_queue);
4355 Print a whole blocking queue starting with the element bqe.
4358 print_bqe (StgBlockingQueueElement *bqe)
4363 NB: In a parallel setup a BQ of an RBH must end with an RBH_Save closure;
4365 for (end = (bqe==END_BQ_QUEUE);
4366 !end; // iterate until bqe points to a CONSTR
4367 end = (get_itbl(bqe)->type == CONSTR) || (bqe->link==END_BQ_QUEUE),
4368 bqe = end ? END_BQ_QUEUE : bqe->link) {
4369 ASSERT(bqe != END_BQ_QUEUE); // sanity check
4370 ASSERT(bqe != (StgBlockingQueueElement *)NULL); // sanity check
4371 /* types of closures that may appear in a blocking queue */
4372 ASSERT(get_itbl(bqe)->type == TSO ||
4373 get_itbl(bqe)->type == BLOCKED_FETCH ||
4374 get_itbl(bqe)->type == CONSTR);
4375 /* only BQs of an RBH end with an RBH_Save closure */
4376 //ASSERT(get_itbl(bqe)->type != CONSTR || get_itbl(node)->type == RBH);
4378 switch (get_itbl(bqe)->type) {
4380 debugBelch(" TSO %u (%x),",
4381 ((StgTSO *)bqe)->id, ((StgTSO *)bqe));
4384 debugBelch(" BF (node=%p, ga=((%x, %d, %x)),",
4385 ((StgBlockedFetch *)bqe)->node,
4386 ((StgBlockedFetch *)bqe)->ga.payload.gc.gtid,
4387 ((StgBlockedFetch *)bqe)->ga.payload.gc.slot,
4388 ((StgBlockedFetch *)bqe)->ga.weight);
4391 debugBelch(" %s (IP %p),",
4392 (get_itbl(bqe) == &stg_RBH_Save_0_info ? "RBH_Save_0" :
4393 get_itbl(bqe) == &stg_RBH_Save_1_info ? "RBH_Save_1" :
4394 get_itbl(bqe) == &stg_RBH_Save_2_info ? "RBH_Save_2" :
4395 "RBH_Save_?"), get_itbl(bqe));
4398 barf("Unexpected closure type %s in blocking queue", // of %p (%s)",
4399 info_type((StgClosure *)bqe)); // , node, info_type(node));
4405 # elif defined(GRAN)
4407 print_bq (StgClosure *node)
4409 StgBlockingQueueElement *bqe;
4410 PEs node_loc, tso_loc;
4413 /* should cover all closures that may have a blocking queue */
4414 ASSERT(get_itbl(node)->type == BLACKHOLE_BQ ||
4415 get_itbl(node)->type == FETCH_ME_BQ ||
4416 get_itbl(node)->type == RBH);
4418 ASSERT(node!=(StgClosure*)NULL); // sanity check
4419 node_loc = where_is(node);
4421 debugBelch("## BQ of closure %p (%s) on [PE %d]: ",
4422 node, info_type(node), node_loc);
4425 NB: In a parallel setup a BQ of an RBH must end with an RBH_Save closure;
4427 for (bqe = ((StgBlockingQueue*)node)->blocking_queue, end = (bqe==END_BQ_QUEUE);
4428 !end; // iterate until bqe points to a CONSTR
4429 end = (get_itbl(bqe)->type == CONSTR) || (bqe->link==END_BQ_QUEUE), bqe = end ? END_BQ_QUEUE : bqe->link) {
4430 ASSERT(bqe != END_BQ_QUEUE); // sanity check
4431 ASSERT(bqe != (StgBlockingQueueElement *)NULL); // sanity check
4432 /* types of closures that may appear in a blocking queue */
4433 ASSERT(get_itbl(bqe)->type == TSO ||
4434 get_itbl(bqe)->type == CONSTR);
4435 /* only BQs of an RBH end with an RBH_Save closure */
4436 ASSERT(get_itbl(bqe)->type != CONSTR || get_itbl(node)->type == RBH);
4438 tso_loc = where_is((StgClosure *)bqe);
4439 switch (get_itbl(bqe)->type) {
4441 debugBelch(" TSO %d (%p) on [PE %d],",
4442 ((StgTSO *)bqe)->id, (StgTSO *)bqe, tso_loc);
4445 debugBelch(" %s (IP %p),",
4446 (get_itbl(bqe) == &stg_RBH_Save_0_info ? "RBH_Save_0" :
4447 get_itbl(bqe) == &stg_RBH_Save_1_info ? "RBH_Save_1" :
4448 get_itbl(bqe) == &stg_RBH_Save_2_info ? "RBH_Save_2" :
4449 "RBH_Save_?"), get_itbl(bqe));
4452 barf("Unexpected closure type %s in blocking queue of %p (%s)",
4453 info_type((StgClosure *)bqe), node, info_type(node));
4461 #if defined(PARALLEL_HASKELL)
4468 for (i=0, tso=run_queue_hd;
4469 tso != END_TSO_QUEUE;
4470 i++, tso=tso->link) {
4479 sched_belch(char *s, ...)
4484 debugBelch("sched (task %p): ", (void *)(unsigned long)(unsigned int)osThreadId());
4485 #elif defined(PARALLEL_HASKELL)
4488 debugBelch("sched: ");