1 /* ---------------------------------------------------------------------------
2 * $Id: Schedule.c,v 1.156 2002/09/25 14:46:31 simonmar Exp $
4 * (c) The GHC Team, 1998-2000
8 * Different GHC ways use this scheduler quite differently (see comments below)
9 * Here is the global picture:
11 * WAY Name CPP flag What's it for
12 * --------------------------------------
13 * mp GUM PAR Parallel execution on a distributed memory machine
14 * s SMP SMP Parallel execution on a shared memory machine
15 * mg GranSim GRAN Simulation of parallel execution
16 * md GUM/GdH DIST Distributed execution (based on GUM)
18 * --------------------------------------------------------------------------*/
20 //@node Main scheduling code, , ,
21 //@section Main scheduling code
24 * Version with scheduler monitor support for SMPs (WAY=s):
26 This design provides a high-level API to create and schedule threads etc.
27 as documented in the SMP design document.
29 It uses a monitor design controlled by a single mutex to exercise control
30 over accesses to shared data structures, and builds on the Posix threads
33 The majority of state is shared. In order to keep essential per-task state,
34 there is a Capability structure, which contains all the information
35 needed to run a thread: its STG registers, a pointer to its TSO, a
36 nursery etc. During STG execution, a pointer to the capability is
37 kept in a register (BaseReg).
39 In a non-SMP build, there is one global capability, namely MainRegTable.
43 * Version with support for distributed memory parallelism aka GUM (WAY=mp):
45 The main scheduling loop in GUM iterates until a finish message is received.
46 In that case a global flag @receivedFinish@ is set and this instance of
47 the RTS shuts down. See ghc/rts/parallel/HLComms.c:processMessages()
48 for the handling of incoming messages, such as PP_FINISH.
49 Note that in the parallel case we have a system manager that coordinates
50 different PEs, each of which are running one instance of the RTS.
51 See ghc/rts/parallel/SysMan.c for the main routine of the parallel program.
52 From this routine processes executing ghc/rts/Main.c are spawned. -- HWL
54 * Version with support for simulating parallel execution aka GranSim (WAY=mg):
56 The main scheduling code in GranSim is quite different from that in std
57 (concurrent) Haskell: while concurrent Haskell just iterates over the
58 threads in the runnable queue, GranSim is event driven, i.e. it iterates
59 over the events in the global event queue. -- HWL
64 //* Variables and Data structures::
65 //* Main scheduling loop::
66 //* Suspend and Resume::
68 //* Garbage Collextion Routines::
69 //* Blocking Queue Routines::
70 //* Exception Handling Routines::
71 //* Debugging Routines::
75 //@node Includes, Variables and Data structures, Main scheduling code, Main scheduling code
76 //@subsection Includes
78 #include "PosixSource.h"
85 #include "StgStartup.h"
87 #define COMPILING_SCHEDULER
89 #include "StgMiscClosures.h"
91 #include "Interpreter.h"
92 #include "Exception.h"
100 #include "ThreadLabels.h"
102 #include "Proftimer.h"
103 #include "ProfHeap.h"
105 #if defined(GRAN) || defined(PAR)
106 # include "GranSimRts.h"
107 # include "GranSim.h"
108 # include "ParallelRts.h"
109 # include "Parallel.h"
110 # include "ParallelDebug.h"
111 # include "FetchMe.h"
115 #include "Capability.h"
116 #include "OSThreads.h"
119 #ifdef HAVE_SYS_TYPES_H
120 #include <sys/types.h>
130 //@node Variables and Data structures, Prototypes, Includes, Main scheduling code
131 //@subsection Variables and Data structures
133 /* Main thread queue.
134 * Locks required: sched_mutex.
136 StgMainThread *main_threads = NULL;
139 * Locks required: sched_mutex.
143 StgTSO* ActiveTSO = NULL; /* for assigning system costs; GranSim-Light only */
144 /* rtsTime TimeOfNextEvent, EndOfTimeSlice; now in GranSim.c */
147 In GranSim we have a runnable and a blocked queue for each processor.
148 In order to minimise code changes new arrays run_queue_hds/tls
149 are created. run_queue_hd is then a short cut (macro) for
150 run_queue_hds[CurrentProc] (see GranSim.h).
153 StgTSO *run_queue_hds[MAX_PROC], *run_queue_tls[MAX_PROC];
154 StgTSO *blocked_queue_hds[MAX_PROC], *blocked_queue_tls[MAX_PROC];
155 StgTSO *ccalling_threadss[MAX_PROC];
156 /* We use the same global list of threads (all_threads) in GranSim as in
157 the std RTS (i.e. we are cheating). However, we don't use this list in
158 the GranSim specific code at the moment (so we are only potentially
163 StgTSO *run_queue_hd = NULL;
164 StgTSO *run_queue_tl = NULL;
165 StgTSO *blocked_queue_hd = NULL;
166 StgTSO *blocked_queue_tl = NULL;
167 StgTSO *sleeping_queue = NULL; /* perhaps replace with a hash table? */
171 /* Linked list of all threads.
172 * Used for detecting garbage collected threads.
174 StgTSO *all_threads = NULL;
176 /* When a thread performs a safe C call (_ccall_GC, using old
177 * terminology), it gets put on the suspended_ccalling_threads
178 * list. Used by the garbage collector.
180 static StgTSO *suspended_ccalling_threads;
182 static StgTSO *threadStackOverflow(StgTSO *tso);
184 /* KH: The following two flags are shared memory locations. There is no need
185 to lock them, since they are only unset at the end of a scheduler
189 /* flag set by signal handler to precipitate a context switch */
190 //@cindex context_switch
191 nat context_switch = 0;
193 /* if this flag is set as well, give up execution */
194 //@cindex interrupted
195 rtsBool interrupted = rtsFalse;
197 /* Next thread ID to allocate.
198 * Locks required: thread_id_mutex
200 //@cindex next_thread_id
201 static StgThreadID next_thread_id = 1;
204 * Pointers to the state of the current thread.
205 * Rule of thumb: if CurrentTSO != NULL, then we're running a Haskell
206 * thread. If CurrentTSO == NULL, then we're at the scheduler level.
209 /* The smallest stack size that makes any sense is:
210 * RESERVED_STACK_WORDS (so we can get back from the stack overflow)
211 * + sizeofW(StgStopFrame) (the stg_stop_thread_info frame)
212 * + 1 (the realworld token for an IO thread)
213 * + 1 (the closure to enter)
215 * A thread with this stack will bomb immediately with a stack
216 * overflow, which will increase its stack size.
219 #define MIN_STACK_WORDS (RESERVED_STACK_WORDS + sizeofW(StgStopFrame) + 2)
226 /* This is used in `TSO.h' and gcc 2.96 insists that this variable actually
227 * exists - earlier gccs apparently didn't.
232 static rtsBool ready_to_gc;
235 * Set to TRUE when entering a shutdown state (via shutdownHaskellAndExit()) --
236 * in an MT setting, needed to signal that a worker thread shouldn't hang around
237 * in the scheduler when it is out of work.
239 static rtsBool shutting_down_scheduler = rtsFalse;
241 void addToBlockedQueue ( StgTSO *tso );
243 static void schedule ( void );
244 void interruptStgRts ( void );
246 static void detectBlackHoles ( void );
249 static void sched_belch(char *s, ...);
252 #if defined(RTS_SUPPORTS_THREADS)
253 /* ToDo: carefully document the invariants that go together
254 * with these synchronisation objects.
256 Mutex sched_mutex = INIT_MUTEX_VAR;
257 Mutex term_mutex = INIT_MUTEX_VAR;
260 * A heavyweight solution to the problem of protecting
261 * the thread_id from concurrent update.
263 Mutex thread_id_mutex = INIT_MUTEX_VAR;
267 static Condition gc_pending_cond = INIT_COND_VAR;
271 #endif /* RTS_SUPPORTS_THREADS */
275 rtsTime TimeOfLastYield;
276 rtsBool emitSchedule = rtsTrue;
280 static char *whatNext_strs[] = {
290 StgTSO * createSparkThread(rtsSpark spark);
291 StgTSO * activateSpark (rtsSpark spark);
295 * The thread state for the main thread.
296 // ToDo: check whether not needed any more
300 #if defined(PAR) || defined(RTS_SUPPORTS_THREADS)
301 static void taskStart(void);
312 //@node Main scheduling loop, Suspend and Resume, Prototypes, Main scheduling code
313 //@subsection Main scheduling loop
315 /* ---------------------------------------------------------------------------
316 Main scheduling loop.
318 We use round-robin scheduling, each thread returning to the
319 scheduler loop when one of these conditions is detected:
322 * timer expires (thread yields)
327 Locking notes: we acquire the scheduler lock once at the beginning
328 of the scheduler loop, and release it when
330 * running a thread, or
331 * waiting for work, or
332 * waiting for a GC to complete.
335 In a GranSim setup this loop iterates over the global event queue.
336 This revolves around the global event queue, which determines what
337 to do next. Therefore, it's more complicated than either the
338 concurrent or the parallel (GUM) setup.
341 GUM iterates over incoming messages.
342 It starts with nothing to do (thus CurrentTSO == END_TSO_QUEUE),
343 and sends out a fish whenever it has nothing to do; in-between
344 doing the actual reductions (shared code below) it processes the
345 incoming messages and deals with delayed operations
346 (see PendingFetches).
347 This is not the ugliest code you could imagine, but it's bloody close.
349 ------------------------------------------------------------------------ */
356 StgThreadReturnCode ret;
364 rtsBool receivedFinish = rtsFalse;
366 nat tp_size, sp_size; // stats only
369 rtsBool was_interrupted = rtsFalse;
371 ACQUIRE_LOCK(&sched_mutex);
373 #if defined(RTS_SUPPORTS_THREADS)
374 waitForWorkCapability(&sched_mutex, &cap, rtsFalse);
376 /* simply initialise it in the non-threaded case */
377 grabCapability(&cap);
381 /* set up first event to get things going */
382 /* ToDo: assign costs for system setup and init MainTSO ! */
383 new_event(CurrentProc, CurrentProc, CurrentTime[CurrentProc],
385 CurrentTSO, (StgClosure*)NULL, (rtsSpark*)NULL);
388 fprintf(stderr, "GRAN: Init CurrentTSO (in schedule) = %p\n", CurrentTSO);
389 G_TSO(CurrentTSO, 5));
391 if (RtsFlags.GranFlags.Light) {
392 /* Save current time; GranSim Light only */
393 CurrentTSO->gran.clock = CurrentTime[CurrentProc];
396 event = get_next_event();
398 while (event!=(rtsEvent*)NULL) {
399 /* Choose the processor with the next event */
400 CurrentProc = event->proc;
401 CurrentTSO = event->tso;
405 while (!receivedFinish) { /* set by processMessages */
406 /* when receiving PP_FINISH message */
413 IF_DEBUG(scheduler, printAllThreads());
415 #if defined(RTS_SUPPORTS_THREADS)
416 /* Check to see whether there are any worker threads
417 waiting to deposit external call results. If so,
418 yield our capability */
419 yieldToReturningWorker(&sched_mutex, &cap);
422 /* If we're interrupted (the user pressed ^C, or some other
423 * termination condition occurred), kill all the currently running
427 IF_DEBUG(scheduler, sched_belch("interrupted"));
429 interrupted = rtsFalse;
430 was_interrupted = rtsTrue;
433 /* Go through the list of main threads and wake up any
434 * clients whose computations have finished. ToDo: this
435 * should be done more efficiently without a linear scan
436 * of the main threads list, somehow...
438 #if defined(RTS_SUPPORTS_THREADS)
440 StgMainThread *m, **prev;
441 prev = &main_threads;
442 for (m = main_threads; m != NULL; m = m->link) {
443 switch (m->tso->what_next) {
446 *(m->ret) = (StgClosure *)m->tso->sp[0];
450 broadcastCondition(&m->wakeup);
452 removeThreadLabel((StgWord)m->tso);
456 if (m->ret) *(m->ret) = NULL;
458 if (was_interrupted) {
459 m->stat = Interrupted;
463 broadcastCondition(&m->wakeup);
465 removeThreadLabel((StgWord)m->tso);
474 #else /* not threaded */
477 /* in GUM do this only on the Main PE */
480 /* If our main thread has finished or been killed, return.
483 StgMainThread *m = main_threads;
484 if (m->tso->what_next == ThreadComplete
485 || m->tso->what_next == ThreadKilled) {
487 removeThreadLabel((StgWord)m->tso);
489 main_threads = main_threads->link;
490 if (m->tso->what_next == ThreadComplete) {
491 /* we finished successfully, fill in the return value */
492 if (m->ret) { *(m->ret) = (StgClosure *)m->tso->sp[0]; };
496 if (m->ret) { *(m->ret) = NULL; };
497 if (was_interrupted) {
498 m->stat = Interrupted;
508 /* Top up the run queue from our spark pool. We try to make the
509 * number of threads in the run queue equal to the number of
512 * Disable spark support in SMP for now, non-essential & requires
513 * a little bit of work to make it compile cleanly. -- sof 1/02.
515 #if 0 /* defined(SMP) */
517 nat n = getFreeCapabilities();
518 StgTSO *tso = run_queue_hd;
520 /* Count the run queue */
521 while (n > 0 && tso != END_TSO_QUEUE) {
528 spark = findSpark(rtsFalse);
530 break; /* no more sparks in the pool */
532 /* I'd prefer this to be done in activateSpark -- HWL */
533 /* tricky - it needs to hold the scheduler lock and
534 * not try to re-acquire it -- SDM */
535 createSparkThread(spark);
537 sched_belch("==^^ turning spark of closure %p into a thread",
538 (StgClosure *)spark));
541 /* We need to wake up the other tasks if we just created some
544 if (getFreeCapabilities() - n > 1) {
545 signalCondition( &thread_ready_cond );
550 /* check for signals each time around the scheduler */
551 #ifndef mingw32_TARGET_OS
552 if (signals_pending()) {
553 RELEASE_LOCK(&sched_mutex); /* ToDo: kill */
554 startSignalHandlers();
555 ACQUIRE_LOCK(&sched_mutex);
559 /* Check whether any waiting threads need to be woken up. If the
560 * run queue is empty, and there are no other tasks running, we
561 * can wait indefinitely for something to happen.
562 * ToDo: what if another client comes along & requests another
565 if ( !EMPTY_QUEUE(blocked_queue_hd) || !EMPTY_QUEUE(sleeping_queue) ) {
566 awaitEvent( EMPTY_RUN_QUEUE()
568 && allFreeCapabilities()
572 /* we can be interrupted while waiting for I/O... */
573 if (interrupted) continue;
576 * Detect deadlock: when we have no threads to run, there are no
577 * threads waiting on I/O or sleeping, and all the other tasks are
578 * waiting for work, we must have a deadlock of some description.
580 * We first try to find threads blocked on themselves (ie. black
581 * holes), and generate NonTermination exceptions where necessary.
583 * If no threads are black holed, we have a deadlock situation, so
584 * inform all the main threads.
587 if ( EMPTY_THREAD_QUEUES()
588 #if defined(RTS_SUPPORTS_THREADS)
589 && EMPTY_QUEUE(suspended_ccalling_threads)
592 && allFreeCapabilities()
596 IF_DEBUG(scheduler, sched_belch("deadlocked, forcing major GC..."));
597 #if defined(THREADED_RTS)
598 /* and SMP mode ..? */
599 releaseCapability(cap);
601 // Garbage collection can release some new threads due to
602 // either (a) finalizers or (b) threads resurrected because
603 // they are about to be send BlockedOnDeadMVar. Any threads
604 // thus released will be immediately runnable.
605 GarbageCollect(GetRoots,rtsTrue);
607 if ( !EMPTY_RUN_QUEUE() ) { goto not_deadlocked; }
610 sched_belch("still deadlocked, checking for black holes..."));
613 if ( !EMPTY_RUN_QUEUE() ) { goto not_deadlocked; }
615 #ifndef mingw32_TARGET_OS
616 /* If we have user-installed signal handlers, then wait
617 * for signals to arrive rather then bombing out with a
620 #if defined(RTS_SUPPORTS_THREADS)
621 if ( 0 ) { /* hmm..what to do? Simply stop waiting for
622 a signal with no runnable threads (or I/O
623 suspended ones) leads nowhere quick.
624 For now, simply shut down when we reach this
627 ToDo: define precisely under what conditions
628 the Scheduler should shut down in an MT setting.
631 if ( anyUserHandlers() ) {
634 sched_belch("still deadlocked, waiting for signals..."));
638 // we might be interrupted...
639 if (interrupted) { continue; }
641 if (signals_pending()) {
642 RELEASE_LOCK(&sched_mutex);
643 startSignalHandlers();
644 ACQUIRE_LOCK(&sched_mutex);
646 ASSERT(!EMPTY_RUN_QUEUE());
651 /* Probably a real deadlock. Send the current main thread the
652 * Deadlock exception (or in the SMP build, send *all* main
653 * threads the deadlock exception, since none of them can make
658 #if defined(RTS_SUPPORTS_THREADS)
659 for (m = main_threads; m != NULL; m = m->link) {
660 switch (m->tso->why_blocked) {
661 case BlockedOnBlackHole:
662 raiseAsync(m->tso, (StgClosure *)NonTermination_closure);
664 case BlockedOnException:
666 raiseAsync(m->tso, (StgClosure *)Deadlock_closure);
669 barf("deadlock: main thread blocked in a strange way");
674 switch (m->tso->why_blocked) {
675 case BlockedOnBlackHole:
676 raiseAsync(m->tso, (StgClosure *)NonTermination_closure);
678 case BlockedOnException:
680 raiseAsync(m->tso, (StgClosure *)Deadlock_closure);
683 barf("deadlock: main thread blocked in a strange way");
688 #if defined(RTS_SUPPORTS_THREADS)
689 /* ToDo: revisit conditions (and mechanism) for shutting
690 down a multi-threaded world */
691 IF_DEBUG(scheduler, sched_belch("all done, i think...shutting down."));
692 RELEASE_LOCK(&sched_mutex);
700 /* ToDo: add deadlock detection in GUM (similar to SMP) -- HWL */
704 /* If there's a GC pending, don't do anything until it has
708 IF_DEBUG(scheduler,sched_belch("waiting for GC"));
709 waitCondition( &gc_pending_cond, &sched_mutex );
713 #if defined(RTS_SUPPORTS_THREADS)
714 /* block until we've got a thread on the run queue and a free
718 if ( EMPTY_RUN_QUEUE() ) {
719 /* Give up our capability */
720 releaseCapability(cap);
722 /* If we're in the process of shutting down (& running the
723 * a batch of finalisers), don't wait around.
725 if ( shutting_down_scheduler ) {
726 RELEASE_LOCK(&sched_mutex);
729 IF_DEBUG(scheduler, sched_belch("thread %d: waiting for work", osThreadId()));
730 waitForWorkCapability(&sched_mutex, &cap, rtsTrue);
731 IF_DEBUG(scheduler, sched_belch("thread %d: work now available", osThreadId()));
736 if (RtsFlags.GranFlags.Light)
737 GranSimLight_enter_system(event, &ActiveTSO); // adjust ActiveTSO etc
739 /* adjust time based on time-stamp */
740 if (event->time > CurrentTime[CurrentProc] &&
741 event->evttype != ContinueThread)
742 CurrentTime[CurrentProc] = event->time;
744 /* Deal with the idle PEs (may issue FindWork or MoveSpark events) */
745 if (!RtsFlags.GranFlags.Light)
748 IF_DEBUG(gran, fprintf(stderr, "GRAN: switch by event-type\n"));
750 /* main event dispatcher in GranSim */
751 switch (event->evttype) {
752 /* Should just be continuing execution */
754 IF_DEBUG(gran, fprintf(stderr, "GRAN: doing ContinueThread\n"));
755 /* ToDo: check assertion
756 ASSERT(run_queue_hd != (StgTSO*)NULL &&
757 run_queue_hd != END_TSO_QUEUE);
759 /* Ignore ContinueThreads for fetching threads (if synchr comm) */
760 if (!RtsFlags.GranFlags.DoAsyncFetch &&
761 procStatus[CurrentProc]==Fetching) {
762 belch("ghuH: Spurious ContinueThread while Fetching ignored; TSO %d (%p) [PE %d]",
763 CurrentTSO->id, CurrentTSO, CurrentProc);
766 /* Ignore ContinueThreads for completed threads */
767 if (CurrentTSO->what_next == ThreadComplete) {
768 belch("ghuH: found a ContinueThread event for completed thread %d (%p) [PE %d] (ignoring ContinueThread)",
769 CurrentTSO->id, CurrentTSO, CurrentProc);
772 /* Ignore ContinueThreads for threads that are being migrated */
773 if (PROCS(CurrentTSO)==Nowhere) {
774 belch("ghuH: trying to run the migrating TSO %d (%p) [PE %d] (ignoring ContinueThread)",
775 CurrentTSO->id, CurrentTSO, CurrentProc);
778 /* The thread should be at the beginning of the run queue */
779 if (CurrentTSO!=run_queue_hds[CurrentProc]) {
780 belch("ghuH: TSO %d (%p) [PE %d] is not at the start of the run_queue when doing a ContinueThread",
781 CurrentTSO->id, CurrentTSO, CurrentProc);
782 break; // run the thread anyway
785 new_event(proc, proc, CurrentTime[proc],
787 (StgTSO*)NULL, (StgClosure*)NULL, (rtsSpark*)NULL);
789 */ /* Catches superfluous CONTINUEs -- should be unnecessary */
790 break; // now actually run the thread; DaH Qu'vam yImuHbej
793 do_the_fetchnode(event);
794 goto next_thread; /* handle next event in event queue */
797 do_the_globalblock(event);
798 goto next_thread; /* handle next event in event queue */
801 do_the_fetchreply(event);
802 goto next_thread; /* handle next event in event queue */
804 case UnblockThread: /* Move from the blocked queue to the tail of */
805 do_the_unblock(event);
806 goto next_thread; /* handle next event in event queue */
808 case ResumeThread: /* Move from the blocked queue to the tail of */
809 /* the runnable queue ( i.e. Qu' SImqa'lu') */
810 event->tso->gran.blocktime +=
811 CurrentTime[CurrentProc] - event->tso->gran.blockedat;
812 do_the_startthread(event);
813 goto next_thread; /* handle next event in event queue */
816 do_the_startthread(event);
817 goto next_thread; /* handle next event in event queue */
820 do_the_movethread(event);
821 goto next_thread; /* handle next event in event queue */
824 do_the_movespark(event);
825 goto next_thread; /* handle next event in event queue */
828 do_the_findwork(event);
829 goto next_thread; /* handle next event in event queue */
832 barf("Illegal event type %u\n", event->evttype);
835 /* This point was scheduler_loop in the old RTS */
837 IF_DEBUG(gran, belch("GRAN: after main switch"));
839 TimeOfLastEvent = CurrentTime[CurrentProc];
840 TimeOfNextEvent = get_time_of_next_event();
841 IgnoreEvents=(TimeOfNextEvent==0); // HWL HACK
842 // CurrentTSO = ThreadQueueHd;
844 IF_DEBUG(gran, belch("GRAN: time of next event is: %ld",
847 if (RtsFlags.GranFlags.Light)
848 GranSimLight_leave_system(event, &ActiveTSO);
850 EndOfTimeSlice = CurrentTime[CurrentProc]+RtsFlags.GranFlags.time_slice;
853 belch("GRAN: end of time-slice is %#lx", EndOfTimeSlice));
855 /* in a GranSim setup the TSO stays on the run queue */
857 /* Take a thread from the run queue. */
858 t = POP_RUN_QUEUE(); // take_off_run_queue(t);
861 fprintf(stderr, "GRAN: About to run current thread, which is\n");
864 context_switch = 0; // turned on via GranYield, checking events and time slice
867 DumpGranEvent(GR_SCHEDULE, t));
869 procStatus[CurrentProc] = Busy;
872 if (PendingFetches != END_BF_QUEUE) {
876 /* ToDo: phps merge with spark activation above */
877 /* check whether we have local work and send requests if we have none */
878 if (EMPTY_RUN_QUEUE()) { /* no runnable threads */
879 /* :-[ no local threads => look out for local sparks */
880 /* the spark pool for the current PE */
881 pool = &(MainRegTable.rSparks); // generalise to cap = &MainRegTable
882 if (advisory_thread_count < RtsFlags.ParFlags.maxThreads &&
883 pool->hd < pool->tl) {
885 * ToDo: add GC code check that we really have enough heap afterwards!!
887 * If we're here (no runnable threads) and we have pending
888 * sparks, we must have a space problem. Get enough space
889 * to turn one of those pending sparks into a
893 spark = findSpark(rtsFalse); /* get a spark */
894 if (spark != (rtsSpark) NULL) {
895 tso = activateSpark(spark); /* turn the spark into a thread */
896 IF_PAR_DEBUG(schedule,
897 belch("==== schedule: Created TSO %d (%p); %d threads active",
898 tso->id, tso, advisory_thread_count));
900 if (tso==END_TSO_QUEUE) { /* failed to activate spark->back to loop */
901 belch("==^^ failed to activate spark");
903 } /* otherwise fall through & pick-up new tso */
905 IF_PAR_DEBUG(verbose,
906 belch("==^^ no local sparks (spark pool contains only NFs: %d)",
907 spark_queue_len(pool)));
912 /* If we still have no work we need to send a FISH to get a spark
915 if (EMPTY_RUN_QUEUE()) {
916 /* =8-[ no local sparks => look for work on other PEs */
918 * We really have absolutely no work. Send out a fish
919 * (there may be some out there already), and wait for
920 * something to arrive. We clearly can't run any threads
921 * until a SCHEDULE or RESUME arrives, and so that's what
922 * we're hoping to see. (Of course, we still have to
923 * respond to other types of messages.)
925 TIME now = msTime() /*CURRENT_TIME*/;
926 IF_PAR_DEBUG(verbose,
927 belch("-- now=%ld", now));
928 IF_PAR_DEBUG(verbose,
929 if (outstandingFishes < RtsFlags.ParFlags.maxFishes &&
930 (last_fish_arrived_at!=0 &&
931 last_fish_arrived_at+RtsFlags.ParFlags.fishDelay > now)) {
932 belch("--$$ delaying FISH until %ld (last fish %ld, delay %ld, now %ld)",
933 last_fish_arrived_at+RtsFlags.ParFlags.fishDelay,
934 last_fish_arrived_at,
935 RtsFlags.ParFlags.fishDelay, now);
938 if (outstandingFishes < RtsFlags.ParFlags.maxFishes &&
939 (last_fish_arrived_at==0 ||
940 (last_fish_arrived_at+RtsFlags.ParFlags.fishDelay <= now))) {
941 /* outstandingFishes is set in sendFish, processFish;
942 avoid flooding system with fishes via delay */
944 sendFish(pe, mytid, NEW_FISH_AGE, NEW_FISH_HISTORY,
947 // Global statistics: count no. of fishes
948 if (RtsFlags.ParFlags.ParStats.Global &&
949 RtsFlags.GcFlags.giveStats > NO_GC_STATS) {
950 globalParStats.tot_fish_mess++;
954 receivedFinish = processMessages();
957 } else if (PacketsWaiting()) { /* Look for incoming messages */
958 receivedFinish = processMessages();
961 /* Now we are sure that we have some work available */
962 ASSERT(run_queue_hd != END_TSO_QUEUE);
964 /* Take a thread from the run queue, if we have work */
965 t = POP_RUN_QUEUE(); // take_off_run_queue(END_TSO_QUEUE);
966 IF_DEBUG(sanity,checkTSO(t));
968 /* ToDo: write something to the log-file
969 if (RTSflags.ParFlags.granSimStats && !sameThread)
970 DumpGranEvent(GR_SCHEDULE, RunnableThreadsHd);
974 /* the spark pool for the current PE */
975 pool = &(MainRegTable.rSparks); // generalise to cap = &MainRegTable
978 belch("--=^ %d threads, %d sparks on [%#x]",
979 run_queue_len(), spark_queue_len(pool), CURRENT_PROC));
982 if (0 && RtsFlags.ParFlags.ParStats.Full &&
983 t && LastTSO && t->id != LastTSO->id &&
984 LastTSO->why_blocked == NotBlocked &&
985 LastTSO->what_next != ThreadComplete) {
986 // if previously scheduled TSO not blocked we have to record the context switch
987 DumpVeryRawGranEvent(TimeOfLastYield, CURRENT_PROC, CURRENT_PROC,
988 GR_DESCHEDULE, LastTSO, (StgClosure *)NULL, 0, 0);
991 if (RtsFlags.ParFlags.ParStats.Full &&
992 (emitSchedule /* forced emit */ ||
993 (t && LastTSO && t->id != LastTSO->id))) {
995 we are running a different TSO, so write a schedule event to log file
996 NB: If we use fair scheduling we also have to write a deschedule
997 event for LastTSO; with unfair scheduling we know that the
998 previous tso has blocked whenever we switch to another tso, so
999 we don't need it in GUM for now
1001 DumpRawGranEvent(CURRENT_PROC, CURRENT_PROC,
1002 GR_SCHEDULE, t, (StgClosure *)NULL, 0, 0);
1003 emitSchedule = rtsFalse;
1007 #else /* !GRAN && !PAR */
1009 /* grab a thread from the run queue */
1010 ASSERT(run_queue_hd != END_TSO_QUEUE);
1011 t = POP_RUN_QUEUE();
1012 // Sanity check the thread we're about to run. This can be
1013 // expensive if there is lots of thread switching going on...
1014 IF_DEBUG(sanity,checkTSO(t));
1017 cap->r.rCurrentTSO = t;
1019 /* context switches are now initiated by the timer signal, unless
1020 * the user specified "context switch as often as possible", with
1025 RtsFlags.ProfFlags.profileInterval == 0 ||
1027 (RtsFlags.ConcFlags.ctxtSwitchTicks == 0
1028 && (run_queue_hd != END_TSO_QUEUE
1029 || blocked_queue_hd != END_TSO_QUEUE
1030 || sleeping_queue != END_TSO_QUEUE)))
1035 RELEASE_LOCK(&sched_mutex);
1037 IF_DEBUG(scheduler, sched_belch("-->> Running TSO %ld (%p) %s ...",
1038 t->id, t, whatNext_strs[t->what_next]));
1041 startHeapProfTimer();
1044 /* +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ */
1045 /* Run the current thread
1047 switch (cap->r.rCurrentTSO->what_next) {
1049 case ThreadComplete:
1050 /* Thread already finished, return to scheduler. */
1051 ret = ThreadFinished;
1053 case ThreadEnterGHC:
1054 ret = StgRun((StgFunPtr) stg_enterStackTop, &cap->r);
1057 ret = StgRun((StgFunPtr) stg_returnToStackTop, &cap->r);
1059 case ThreadEnterInterp:
1060 ret = interpretBCO(cap);
1063 barf("schedule: invalid what_next field");
1065 /* +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ */
1067 /* Costs for the scheduler are assigned to CCS_SYSTEM */
1069 stopHeapProfTimer();
1073 ACQUIRE_LOCK(&sched_mutex);
1076 IF_DEBUG(scheduler,fprintf(stderr,"scheduler (task %ld): ", osThreadId()););
1077 #elif !defined(GRAN) && !defined(PAR)
1078 IF_DEBUG(scheduler,fprintf(stderr,"scheduler: "););
1080 t = cap->r.rCurrentTSO;
1083 /* HACK 675: if the last thread didn't yield, make sure to print a
1084 SCHEDULE event to the log file when StgRunning the next thread, even
1085 if it is the same one as before */
1087 TimeOfLastYield = CURRENT_TIME;
1093 IF_DEBUG(gran, DumpGranEvent(GR_DESCHEDULE, t));
1094 globalGranStats.tot_heapover++;
1096 globalParStats.tot_heapover++;
1099 // did the task ask for a large block?
1100 if (cap->r.rHpAlloc > BLOCK_SIZE_W) {
1101 // if so, get one and push it on the front of the nursery.
1105 blocks = (nat)BLOCK_ROUND_UP(cap->r.rHpAlloc * sizeof(W_)) / BLOCK_SIZE;
1107 IF_DEBUG(scheduler,belch("--<< thread %ld (%p; %s) stopped: requesting a large block (size %d)",
1109 whatNext_strs[t->what_next], blocks));
1111 // don't do this if it would push us over the
1112 // alloc_blocks_lim limit; we'll GC first.
1113 if (alloc_blocks + blocks < alloc_blocks_lim) {
1115 alloc_blocks += blocks;
1116 bd = allocGroup( blocks );
1118 // link the new group into the list
1119 bd->link = cap->r.rCurrentNursery;
1120 bd->u.back = cap->r.rCurrentNursery->u.back;
1121 if (cap->r.rCurrentNursery->u.back != NULL) {
1122 cap->r.rCurrentNursery->u.back->link = bd;
1124 ASSERT(g0s0->blocks == cap->r.rCurrentNursery &&
1125 g0s0->blocks == cap->r.rNursery);
1126 cap->r.rNursery = g0s0->blocks = bd;
1128 cap->r.rCurrentNursery->u.back = bd;
1130 // initialise it as a nursery block. We initialise the
1131 // step, gen_no, and flags field of *every* sub-block in
1132 // this large block, because this is easier than making
1133 // sure that we always find the block head of a large
1134 // block whenever we call Bdescr() (eg. evacuate() and
1135 // isAlive() in the GC would both have to do this, at
1139 for (x = bd; x < bd + blocks; x++) {
1147 // don't forget to update the block count in g0s0.
1148 g0s0->n_blocks += blocks;
1149 ASSERT(countBlocks(g0s0->blocks) == g0s0->n_blocks);
1151 // now update the nursery to point to the new block
1152 cap->r.rCurrentNursery = bd;
1154 // we might be unlucky and have another thread get on the
1155 // run queue before us and steal the large block, but in that
1156 // case the thread will just end up requesting another large
1158 PUSH_ON_RUN_QUEUE(t);
1163 /* make all the running tasks block on a condition variable,
1164 * maybe set context_switch and wait till they all pile in,
1165 * then have them wait on a GC condition variable.
1167 IF_DEBUG(scheduler,belch("--<< thread %ld (%p; %s) stopped: HeapOverflow",
1168 t->id, t, whatNext_strs[t->what_next]));
1171 ASSERT(!is_on_queue(t,CurrentProc));
1173 /* Currently we emit a DESCHEDULE event before GC in GUM.
1174 ToDo: either add separate event to distinguish SYSTEM time from rest
1175 or just nuke this DESCHEDULE (and the following SCHEDULE) */
1176 if (0 && RtsFlags.ParFlags.ParStats.Full) {
1177 DumpRawGranEvent(CURRENT_PROC, CURRENT_PROC,
1178 GR_DESCHEDULE, t, (StgClosure *)NULL, 0, 0);
1179 emitSchedule = rtsTrue;
1183 ready_to_gc = rtsTrue;
1184 context_switch = 1; /* stop other threads ASAP */
1185 PUSH_ON_RUN_QUEUE(t);
1186 /* actual GC is done at the end of the while loop */
1192 DumpGranEvent(GR_DESCHEDULE, t));
1193 globalGranStats.tot_stackover++;
1196 // DumpGranEvent(GR_DESCHEDULE, t);
1197 globalParStats.tot_stackover++;
1199 IF_DEBUG(scheduler,belch("--<< thread %ld (%p; %s) stopped, StackOverflow",
1200 t->id, t, whatNext_strs[t->what_next]));
1201 /* just adjust the stack for this thread, then pop it back
1207 /* enlarge the stack */
1208 StgTSO *new_t = threadStackOverflow(t);
1210 /* This TSO has moved, so update any pointers to it from the
1211 * main thread stack. It better not be on any other queues...
1212 * (it shouldn't be).
1214 for (m = main_threads; m != NULL; m = m->link) {
1219 threadPaused(new_t);
1220 PUSH_ON_RUN_QUEUE(new_t);
1224 case ThreadYielding:
1227 DumpGranEvent(GR_DESCHEDULE, t));
1228 globalGranStats.tot_yields++;
1231 // DumpGranEvent(GR_DESCHEDULE, t);
1232 globalParStats.tot_yields++;
1234 /* put the thread back on the run queue. Then, if we're ready to
1235 * GC, check whether this is the last task to stop. If so, wake
1236 * up the GC thread. getThread will block during a GC until the
1240 if (t->what_next == ThreadEnterInterp) {
1241 /* ToDo: or maybe a timer expired when we were in Hugs?
1242 * or maybe someone hit ctrl-C
1244 belch("--<< thread %ld (%p; %s) stopped to switch to Hugs",
1245 t->id, t, whatNext_strs[t->what_next]);
1247 belch("--<< thread %ld (%p; %s) stopped, yielding",
1248 t->id, t, whatNext_strs[t->what_next]);
1255 //belch("&& Doing sanity check on yielding TSO %ld.", t->id);
1257 ASSERT(t->link == END_TSO_QUEUE);
1259 ASSERT(!is_on_queue(t,CurrentProc));
1262 //belch("&& Doing sanity check on all ThreadQueues (and their TSOs).");
1263 checkThreadQsSanity(rtsTrue));
1266 if (RtsFlags.ParFlags.doFairScheduling) {
1267 /* this does round-robin scheduling; good for concurrency */
1268 APPEND_TO_RUN_QUEUE(t);
1270 /* this does unfair scheduling; good for parallelism */
1271 PUSH_ON_RUN_QUEUE(t);
1274 /* this does round-robin scheduling; good for concurrency */
1275 APPEND_TO_RUN_QUEUE(t);
1278 /* add a ContinueThread event to actually process the thread */
1279 new_event(CurrentProc, CurrentProc, CurrentTime[CurrentProc],
1281 t, (StgClosure*)NULL, (rtsSpark*)NULL);
1283 belch("GRAN: eventq and runnableq after adding yielded thread to queue again:");
1292 belch("--<< thread %ld (%p; %s) stopped, blocking on node %p [PE %d] with BQ: ",
1293 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)));
1294 if (t->block_info.closure!=(StgClosure*)NULL) print_bq(t->block_info.closure));
1296 // ??? needed; should emit block before
1298 DumpGranEvent(GR_DESCHEDULE, t));
1299 prune_eventq(t, (StgClosure *)NULL); // prune ContinueThreads for t
1302 ASSERT(procStatus[CurrentProc]==Busy ||
1303 ((procStatus[CurrentProc]==Fetching) &&
1304 (t->block_info.closure!=(StgClosure*)NULL)));
1305 if (run_queue_hds[CurrentProc] == END_TSO_QUEUE &&
1306 !(!RtsFlags.GranFlags.DoAsyncFetch &&
1307 procStatus[CurrentProc]==Fetching))
1308 procStatus[CurrentProc] = Idle;
1312 belch("--<< thread %ld (%p; %s) stopped, blocking on node %p with BQ: ",
1313 t->id, t, whatNext_strs[t->what_next], t->block_info.closure));
1316 if (t->block_info.closure!=(StgClosure*)NULL)
1317 print_bq(t->block_info.closure));
1319 /* Send a fetch (if BlockedOnGA) and dump event to log file */
1322 /* whatever we schedule next, we must log that schedule */
1323 emitSchedule = rtsTrue;
1326 /* don't need to do anything. Either the thread is blocked on
1327 * I/O, in which case we'll have called addToBlockedQueue
1328 * previously, or it's blocked on an MVar or Blackhole, in which
1329 * case it'll be on the relevant queue already.
1332 fprintf(stderr, "--<< thread %d (%p) stopped: ", t->id, t);
1333 printThreadBlockage(t);
1334 fprintf(stderr, "\n"));
1336 /* Only for dumping event to log file
1337 ToDo: do I need this in GranSim, too?
1344 case ThreadFinished:
1345 /* Need to check whether this was a main thread, and if so, signal
1346 * the task that started it with the return value. If we have no
1347 * more main threads, we probably need to stop all the tasks until
1350 /* We also end up here if the thread kills itself with an
1351 * uncaught exception, see Exception.hc.
1353 IF_DEBUG(scheduler,belch("--++ thread %d (%p) finished", t->id, t));
1355 endThread(t, CurrentProc); // clean-up the thread
1357 /* For now all are advisory -- HWL */
1358 //if(t->priority==AdvisoryPriority) ??
1359 advisory_thread_count--;
1362 if(t->dist.priority==RevalPriority)
1366 if (RtsFlags.ParFlags.ParStats.Full &&
1367 !RtsFlags.ParFlags.ParStats.Suppressed)
1368 DumpEndEvent(CURRENT_PROC, t, rtsFalse /* not mandatory */);
1373 barf("schedule: invalid thread return code %d", (int)ret);
1377 if (RtsFlags.ProfFlags.profileInterval==0 || performHeapProfile) {
1378 GarbageCollect(GetRoots, rtsTrue);
1380 performHeapProfile = rtsFalse;
1381 ready_to_gc = rtsFalse; // we already GC'd
1387 && allFreeCapabilities()
1390 /* everybody back, start the GC.
1391 * Could do it in this thread, or signal a condition var
1392 * to do it in another thread. Either way, we need to
1393 * broadcast on gc_pending_cond afterward.
1395 #if defined(RTS_SUPPORTS_THREADS)
1396 IF_DEBUG(scheduler,sched_belch("doing GC"));
1398 GarbageCollect(GetRoots,rtsFalse);
1399 ready_to_gc = rtsFalse;
1401 broadcastCondition(&gc_pending_cond);
1404 /* add a ContinueThread event to continue execution of current thread */
1405 new_event(CurrentProc, CurrentProc, CurrentTime[CurrentProc],
1407 t, (StgClosure*)NULL, (rtsSpark*)NULL);
1409 fprintf(stderr, "GRAN: eventq and runnableq after Garbage collection:\n");
1417 IF_GRAN_DEBUG(unused,
1418 print_eventq(EventHd));
1420 event = get_next_event();
1423 /* ToDo: wait for next message to arrive rather than busy wait */
1426 } /* end of while(1) */
1428 IF_PAR_DEBUG(verbose,
1429 belch("== Leaving schedule() after having received Finish"));
1432 /* ---------------------------------------------------------------------------
1433 * Singleton fork(). Do not copy any running threads.
1434 * ------------------------------------------------------------------------- */
1436 StgInt forkProcess(StgTSO* tso) {
1438 #ifndef mingw32_TARGET_OS
1444 IF_DEBUG(scheduler,sched_belch("forking!"));
1447 if (pid) { /* parent */
1449 /* just return the pid */
1451 } else { /* child */
1452 /* wipe all other threads */
1453 run_queue_hd = run_queue_tl = tso;
1454 tso->link = END_TSO_QUEUE;
1456 /* When clearing out the threads, we need to ensure
1457 that a 'main thread' is left behind; if there isn't,
1458 the Scheduler will shutdown next time it is entered.
1460 ==> we don't kill a thread that's on the main_threads
1461 list (nor the current thread.)
1463 [ Attempts at implementing the more ambitious scheme of
1464 killing the main_threads also, and then adding the
1465 current thread onto the main_threads list if it wasn't
1466 there already, failed -- waitThread() (for one) wasn't
1467 up to it. If it proves to be desirable to also kill
1468 the main threads, then this scheme will have to be
1469 revisited (and fully debugged!)
1474 /* DO NOT TOUCH THE QUEUES directly because most of the code around
1475 us is picky about finding the thread still in its queue when
1476 handling the deleteThread() */
1478 for (t = all_threads; t != END_TSO_QUEUE; t = next) {
1481 /* Don't kill the current thread.. */
1482 if (t->id == tso->id) continue;
1484 /* ..or a main thread */
1485 for (m = main_threads; m != NULL; m = m->link) {
1486 if (m->tso->id == t->id) {
1498 barf("forkProcess#: primop not implemented for mingw32, sorry! (%u)\n", tso->id);
1499 /* pointlessly printing out the TSOs 'id' to avoid CC unused warning. */
1501 #endif /* mingw32 */
1504 /* ---------------------------------------------------------------------------
1505 * deleteAllThreads(): kill all the live threads.
1507 * This is used when we catch a user interrupt (^C), before performing
1508 * any necessary cleanups and running finalizers.
1510 * Locks: sched_mutex held.
1511 * ------------------------------------------------------------------------- */
1513 void deleteAllThreads ( void )
1516 IF_DEBUG(scheduler,sched_belch("deleting all threads"));
1517 for (t = all_threads; t != END_TSO_QUEUE; t = next) {
1518 next = t->global_link;
1521 run_queue_hd = run_queue_tl = END_TSO_QUEUE;
1522 blocked_queue_hd = blocked_queue_tl = END_TSO_QUEUE;
1523 sleeping_queue = END_TSO_QUEUE;
1526 /* startThread and insertThread are now in GranSim.c -- HWL */
1529 //@node Suspend and Resume, Run queue code, Main scheduling loop, Main scheduling code
1530 //@subsection Suspend and Resume
1532 /* ---------------------------------------------------------------------------
1533 * Suspending & resuming Haskell threads.
1535 * When making a "safe" call to C (aka _ccall_GC), the task gives back
1536 * its capability before calling the C function. This allows another
1537 * task to pick up the capability and carry on running Haskell
1538 * threads. It also means that if the C call blocks, it won't lock
1541 * The Haskell thread making the C call is put to sleep for the
1542 * duration of the call, on the susepended_ccalling_threads queue. We
1543 * give out a token to the task, which it can use to resume the thread
1544 * on return from the C function.
1545 * ------------------------------------------------------------------------- */
1548 suspendThread( StgRegTable *reg,
1550 #if !defined(RTS_SUPPORTS_THREADS) && !defined(DEBUG)
1558 /* assume that *reg is a pointer to the StgRegTable part
1561 cap = (Capability *)((void *)reg - sizeof(StgFunTable));
1563 ACQUIRE_LOCK(&sched_mutex);
1566 sched_belch("thread %d did a _ccall_gc (is_concurrent: %d)", cap->r.rCurrentTSO->id,concCall));
1568 threadPaused(cap->r.rCurrentTSO);
1569 cap->r.rCurrentTSO->link = suspended_ccalling_threads;
1570 suspended_ccalling_threads = cap->r.rCurrentTSO;
1572 #if defined(RTS_SUPPORTS_THREADS)
1573 cap->r.rCurrentTSO->why_blocked = BlockedOnCCall;
1576 /* Use the thread ID as the token; it should be unique */
1577 tok = cap->r.rCurrentTSO->id;
1579 /* Hand back capability */
1580 releaseCapability(cap);
1582 #if defined(RTS_SUPPORTS_THREADS)
1583 /* Preparing to leave the RTS, so ensure there's a native thread/task
1584 waiting to take over.
1586 ToDo: optimise this and only create a new task if there's a need
1587 for one (i.e., if there's only one Concurrent Haskell thread alive,
1588 there's no need to create a new task).
1590 IF_DEBUG(scheduler, sched_belch("worker thread (%d): leaving RTS", tok));
1592 startTask(taskStart);
1596 /* Other threads _might_ be available for execution; signal this */
1598 RELEASE_LOCK(&sched_mutex);
1603 resumeThread( StgInt tok,
1605 #if !defined(RTS_SUPPORTS_THREADS)
1610 StgTSO *tso, **prev;
1613 #if defined(RTS_SUPPORTS_THREADS)
1614 /* Wait for permission to re-enter the RTS with the result. */
1616 ACQUIRE_LOCK(&sched_mutex);
1617 grabReturnCapability(&sched_mutex, &cap);
1619 grabCapability(&cap);
1622 grabCapability(&cap);
1625 /* Remove the thread off of the suspended list */
1626 prev = &suspended_ccalling_threads;
1627 for (tso = suspended_ccalling_threads;
1628 tso != END_TSO_QUEUE;
1629 prev = &tso->link, tso = tso->link) {
1630 if (tso->id == (StgThreadID)tok) {
1635 if (tso == END_TSO_QUEUE) {
1636 barf("resumeThread: thread not found");
1638 tso->link = END_TSO_QUEUE;
1639 /* Reset blocking status */
1640 tso->why_blocked = NotBlocked;
1642 cap->r.rCurrentTSO = tso;
1643 RELEASE_LOCK(&sched_mutex);
1648 /* ---------------------------------------------------------------------------
1650 * ------------------------------------------------------------------------ */
1651 static void unblockThread(StgTSO *tso);
1653 /* ---------------------------------------------------------------------------
1654 * Comparing Thread ids.
1656 * This is used from STG land in the implementation of the
1657 * instances of Eq/Ord for ThreadIds.
1658 * ------------------------------------------------------------------------ */
1660 int cmp_thread(const StgTSO *tso1, const StgTSO *tso2)
1662 StgThreadID id1 = tso1->id;
1663 StgThreadID id2 = tso2->id;
1665 if (id1 < id2) return (-1);
1666 if (id1 > id2) return 1;
1670 /* ---------------------------------------------------------------------------
1671 * Fetching the ThreadID from an StgTSO.
1673 * This is used in the implementation of Show for ThreadIds.
1674 * ------------------------------------------------------------------------ */
1675 int rts_getThreadId(const StgTSO *tso)
1681 void labelThread(StgTSO *tso, char *label)
1686 /* Caveat: Once set, you can only set the thread name to "" */
1687 len = strlen(label)+1;
1690 fprintf(stderr,"insufficient memory for labelThread!\n");
1692 strncpy(buf,label,len);
1693 /* Update will free the old memory for us */
1694 updateThreadLabel((StgWord)tso,buf);
1698 /* ---------------------------------------------------------------------------
1699 Create a new thread.
1701 The new thread starts with the given stack size. Before the
1702 scheduler can run, however, this thread needs to have a closure
1703 (and possibly some arguments) pushed on its stack. See
1704 pushClosure() in Schedule.h.
1706 createGenThread() and createIOThread() (in SchedAPI.h) are
1707 convenient packaged versions of this function.
1709 currently pri (priority) is only used in a GRAN setup -- HWL
1710 ------------------------------------------------------------------------ */
1711 //@cindex createThread
1713 /* currently pri (priority) is only used in a GRAN setup -- HWL */
1715 createThread(nat size, StgInt pri)
1718 createThread(nat size)
1725 /* First check whether we should create a thread at all */
1727 /* check that no more than RtsFlags.ParFlags.maxThreads threads are created */
1728 if (advisory_thread_count >= RtsFlags.ParFlags.maxThreads) {
1730 belch("{createThread}Daq ghuH: refusing to create another thread; no more than %d threads allowed (currently %d)",
1731 RtsFlags.ParFlags.maxThreads, advisory_thread_count);
1732 return END_TSO_QUEUE;
1738 ASSERT(!RtsFlags.GranFlags.Light || CurrentProc==0);
1741 // ToDo: check whether size = stack_size - TSO_STRUCT_SIZEW
1743 /* catch ridiculously small stack sizes */
1744 if (size < MIN_STACK_WORDS + TSO_STRUCT_SIZEW) {
1745 size = MIN_STACK_WORDS + TSO_STRUCT_SIZEW;
1748 stack_size = size - TSO_STRUCT_SIZEW;
1750 tso = (StgTSO *)allocate(size);
1751 TICK_ALLOC_TSO(stack_size, 0);
1753 SET_HDR(tso, &stg_TSO_info, CCS_SYSTEM);
1755 SET_GRAN_HDR(tso, ThisPE);
1757 tso->what_next = ThreadEnterGHC;
1759 /* tso->id needs to be unique. For now we use a heavyweight mutex to
1760 * protect the increment operation on next_thread_id.
1761 * In future, we could use an atomic increment instead.
1763 ACQUIRE_LOCK(&thread_id_mutex);
1764 tso->id = next_thread_id++;
1765 RELEASE_LOCK(&thread_id_mutex);
1767 tso->why_blocked = NotBlocked;
1768 tso->blocked_exceptions = NULL;
1770 tso->stack_size = stack_size;
1771 tso->max_stack_size = round_to_mblocks(RtsFlags.GcFlags.maxStkSize)
1773 tso->sp = (P_)&(tso->stack) + stack_size;
1776 tso->prof.CCCS = CCS_MAIN;
1779 /* put a stop frame on the stack */
1780 tso->sp -= sizeofW(StgStopFrame);
1781 SET_HDR((StgClosure*)tso->sp,(StgInfoTable *)&stg_stop_thread_info,CCS_SYSTEM);
1782 tso->su = (StgUpdateFrame*)tso->sp;
1786 tso->link = END_TSO_QUEUE;
1787 /* uses more flexible routine in GranSim */
1788 insertThread(tso, CurrentProc);
1790 /* In a non-GranSim setup the pushing of a TSO onto the runq is separated
1796 if (RtsFlags.GranFlags.GranSimStats.Full)
1797 DumpGranEvent(GR_START,tso);
1799 if (RtsFlags.ParFlags.ParStats.Full)
1800 DumpGranEvent(GR_STARTQ,tso);
1801 /* HACk to avoid SCHEDULE
1805 /* Link the new thread on the global thread list.
1807 tso->global_link = all_threads;
1811 tso->dist.priority = MandatoryPriority; //by default that is...
1815 tso->gran.pri = pri;
1817 tso->gran.magic = TSO_MAGIC; // debugging only
1819 tso->gran.sparkname = 0;
1820 tso->gran.startedat = CURRENT_TIME;
1821 tso->gran.exported = 0;
1822 tso->gran.basicblocks = 0;
1823 tso->gran.allocs = 0;
1824 tso->gran.exectime = 0;
1825 tso->gran.fetchtime = 0;
1826 tso->gran.fetchcount = 0;
1827 tso->gran.blocktime = 0;
1828 tso->gran.blockcount = 0;
1829 tso->gran.blockedat = 0;
1830 tso->gran.globalsparks = 0;
1831 tso->gran.localsparks = 0;
1832 if (RtsFlags.GranFlags.Light)
1833 tso->gran.clock = Now; /* local clock */
1835 tso->gran.clock = 0;
1837 IF_DEBUG(gran,printTSO(tso));
1840 tso->par.magic = TSO_MAGIC; // debugging only
1842 tso->par.sparkname = 0;
1843 tso->par.startedat = CURRENT_TIME;
1844 tso->par.exported = 0;
1845 tso->par.basicblocks = 0;
1846 tso->par.allocs = 0;
1847 tso->par.exectime = 0;
1848 tso->par.fetchtime = 0;
1849 tso->par.fetchcount = 0;
1850 tso->par.blocktime = 0;
1851 tso->par.blockcount = 0;
1852 tso->par.blockedat = 0;
1853 tso->par.globalsparks = 0;
1854 tso->par.localsparks = 0;
1858 globalGranStats.tot_threads_created++;
1859 globalGranStats.threads_created_on_PE[CurrentProc]++;
1860 globalGranStats.tot_sq_len += spark_queue_len(CurrentProc);
1861 globalGranStats.tot_sq_probes++;
1863 // collect parallel global statistics (currently done together with GC stats)
1864 if (RtsFlags.ParFlags.ParStats.Global &&
1865 RtsFlags.GcFlags.giveStats > NO_GC_STATS) {
1866 //fprintf(stderr, "Creating thread %d @ %11.2f\n", tso->id, usertime());
1867 globalParStats.tot_threads_created++;
1873 belch("==__ schedule: Created TSO %d (%p);",
1874 CurrentProc, tso, tso->id));
1876 IF_PAR_DEBUG(verbose,
1877 belch("==__ schedule: Created TSO %d (%p); %d threads active",
1878 tso->id, tso, advisory_thread_count));
1880 IF_DEBUG(scheduler,sched_belch("created thread %ld, stack size = %lx words",
1881 tso->id, tso->stack_size));
1888 all parallel thread creation calls should fall through the following routine.
1891 createSparkThread(rtsSpark spark)
1893 ASSERT(spark != (rtsSpark)NULL);
1894 if (advisory_thread_count >= RtsFlags.ParFlags.maxThreads)
1896 barf("{createSparkThread}Daq ghuH: refusing to create another thread; no more than %d threads allowed (currently %d)",
1897 RtsFlags.ParFlags.maxThreads, advisory_thread_count);
1898 return END_TSO_QUEUE;
1902 tso = createThread(RtsFlags.GcFlags.initialStkSize);
1903 if (tso==END_TSO_QUEUE)
1904 barf("createSparkThread: Cannot create TSO");
1906 tso->priority = AdvisoryPriority;
1908 pushClosure(tso,spark);
1909 PUSH_ON_RUN_QUEUE(tso);
1910 advisory_thread_count++;
1917 Turn a spark into a thread.
1918 ToDo: fix for SMP (needs to acquire SCHED_MUTEX!)
1921 //@cindex activateSpark
1923 activateSpark (rtsSpark spark)
1927 tso = createSparkThread(spark);
1928 if (RtsFlags.ParFlags.ParStats.Full) {
1929 //ASSERT(run_queue_hd == END_TSO_QUEUE); // I think ...
1930 IF_PAR_DEBUG(verbose,
1931 belch("==^^ activateSpark: turning spark of closure %p (%s) into a thread",
1932 (StgClosure *)spark, info_type((StgClosure *)spark)));
1934 // ToDo: fwd info on local/global spark to thread -- HWL
1935 // tso->gran.exported = spark->exported;
1936 // tso->gran.locked = !spark->global;
1937 // tso->gran.sparkname = spark->name;
1943 static SchedulerStatus waitThread_(/*out*/StgMainThread* m
1944 #if defined(THREADED_RTS)
1945 , rtsBool blockWaiting
1950 /* ---------------------------------------------------------------------------
1953 * scheduleThread puts a thread on the head of the runnable queue.
1954 * This will usually be done immediately after a thread is created.
1955 * The caller of scheduleThread must create the thread using e.g.
1956 * createThread and push an appropriate closure
1957 * on this thread's stack before the scheduler is invoked.
1958 * ------------------------------------------------------------------------ */
1960 static void scheduleThread_ (StgTSO* tso, rtsBool createTask);
1963 scheduleThread_(StgTSO *tso
1964 , rtsBool createTask
1965 #if !defined(THREADED_RTS)
1970 ACQUIRE_LOCK(&sched_mutex);
1972 /* Put the new thread on the head of the runnable queue. The caller
1973 * better push an appropriate closure on this thread's stack
1974 * beforehand. In the SMP case, the thread may start running as
1975 * soon as we release the scheduler lock below.
1977 PUSH_ON_RUN_QUEUE(tso);
1978 #if defined(THREADED_RTS)
1979 /* If main() is scheduling a thread, don't bother creating a
1983 startTask(taskStart);
1989 IF_DEBUG(scheduler,printTSO(tso));
1991 RELEASE_LOCK(&sched_mutex);
1994 void scheduleThread(StgTSO* tso)
1996 scheduleThread_(tso, rtsFalse);
2000 scheduleWaitThread(StgTSO* tso, /*[out]*/HaskellObj* ret)
2004 m = stgMallocBytes(sizeof(StgMainThread), "waitThread");
2008 #if defined(RTS_SUPPORTS_THREADS)
2009 initCondition(&m->wakeup);
2012 /* Put the thread on the main-threads list prior to scheduling the TSO.
2013 Failure to do so introduces a race condition in the MT case (as
2014 identified by Wolfgang Thaller), whereby the new task/OS thread
2015 created by scheduleThread_() would complete prior to the thread
2016 that spawned it managed to put 'itself' on the main-threads list.
2017 The upshot of it all being that the worker thread wouldn't get to
2018 signal the completion of the its work item for the main thread to
2019 see (==> it got stuck waiting.) -- sof 6/02.
2021 ACQUIRE_LOCK(&sched_mutex);
2022 IF_DEBUG(scheduler, sched_belch("== scheduler: waiting for thread (%d)\n", tso->id));
2024 m->link = main_threads;
2027 /* Inefficient (scheduleThread_() acquires it again right away),
2028 * but obviously correct.
2030 RELEASE_LOCK(&sched_mutex);
2032 scheduleThread_(tso, rtsTrue);
2033 #if defined(THREADED_RTS)
2034 return waitThread_(m, rtsTrue);
2036 return waitThread_(m);
2040 /* ---------------------------------------------------------------------------
2043 * Initialise the scheduler. This resets all the queues - if the
2044 * queues contained any threads, they'll be garbage collected at the
2047 * ------------------------------------------------------------------------ */
2051 term_handler(int sig STG_UNUSED)
2054 ACQUIRE_LOCK(&term_mutex);
2056 RELEASE_LOCK(&term_mutex);
2067 for (i=0; i<=MAX_PROC; i++) {
2068 run_queue_hds[i] = END_TSO_QUEUE;
2069 run_queue_tls[i] = END_TSO_QUEUE;
2070 blocked_queue_hds[i] = END_TSO_QUEUE;
2071 blocked_queue_tls[i] = END_TSO_QUEUE;
2072 ccalling_threadss[i] = END_TSO_QUEUE;
2073 sleeping_queue = END_TSO_QUEUE;
2076 run_queue_hd = END_TSO_QUEUE;
2077 run_queue_tl = END_TSO_QUEUE;
2078 blocked_queue_hd = END_TSO_QUEUE;
2079 blocked_queue_tl = END_TSO_QUEUE;
2080 sleeping_queue = END_TSO_QUEUE;
2083 suspended_ccalling_threads = END_TSO_QUEUE;
2085 main_threads = NULL;
2086 all_threads = END_TSO_QUEUE;
2091 RtsFlags.ConcFlags.ctxtSwitchTicks =
2092 RtsFlags.ConcFlags.ctxtSwitchTime / TICK_MILLISECS;
2094 #if defined(RTS_SUPPORTS_THREADS)
2095 /* Initialise the mutex and condition variables used by
2097 initMutex(&sched_mutex);
2098 initMutex(&term_mutex);
2099 initMutex(&thread_id_mutex);
2101 initCondition(&thread_ready_cond);
2105 initCondition(&gc_pending_cond);
2108 #if defined(RTS_SUPPORTS_THREADS)
2109 ACQUIRE_LOCK(&sched_mutex);
2112 /* Install the SIGHUP handler */
2115 struct sigaction action,oact;
2117 action.sa_handler = term_handler;
2118 sigemptyset(&action.sa_mask);
2119 action.sa_flags = 0;
2120 if (sigaction(SIGTERM, &action, &oact) != 0) {
2121 barf("can't install TERM handler");
2126 /* A capability holds the state a native thread needs in
2127 * order to execute STG code. At least one capability is
2128 * floating around (only SMP builds have more than one).
2132 #if defined(RTS_SUPPORTS_THREADS)
2133 /* start our haskell execution tasks */
2135 startTaskManager(RtsFlags.ParFlags.nNodes, taskStart);
2137 startTaskManager(0,taskStart);
2141 #if /* defined(SMP) ||*/ defined(PAR)
2145 #if defined(RTS_SUPPORTS_THREADS)
2146 RELEASE_LOCK(&sched_mutex);
2152 exitScheduler( void )
2154 #if defined(RTS_SUPPORTS_THREADS)
2157 shutting_down_scheduler = rtsTrue;
2160 /* -----------------------------------------------------------------------------
2161 Managing the per-task allocation areas.
2163 Each capability comes with an allocation area. These are
2164 fixed-length block lists into which allocation can be done.
2166 ToDo: no support for two-space collection at the moment???
2167 -------------------------------------------------------------------------- */
2169 /* -----------------------------------------------------------------------------
2170 * waitThread is the external interface for running a new computation
2171 * and waiting for the result.
2173 * In the non-SMP case, we create a new main thread, push it on the
2174 * main-thread stack, and invoke the scheduler to run it. The
2175 * scheduler will return when the top main thread on the stack has
2176 * completed or died, and fill in the necessary fields of the
2177 * main_thread structure.
2179 * In the SMP case, we create a main thread as before, but we then
2180 * create a new condition variable and sleep on it. When our new
2181 * main thread has completed, we'll be woken up and the status/result
2182 * will be in the main_thread struct.
2183 * -------------------------------------------------------------------------- */
2186 howManyThreadsAvail ( void )
2190 for (q = run_queue_hd; q != END_TSO_QUEUE; q = q->link)
2192 for (q = blocked_queue_hd; q != END_TSO_QUEUE; q = q->link)
2194 for (q = sleeping_queue; q != END_TSO_QUEUE; q = q->link)
2200 finishAllThreads ( void )
2203 while (run_queue_hd != END_TSO_QUEUE) {
2204 waitThread ( run_queue_hd, NULL);
2206 while (blocked_queue_hd != END_TSO_QUEUE) {
2207 waitThread ( blocked_queue_hd, NULL);
2209 while (sleeping_queue != END_TSO_QUEUE) {
2210 waitThread ( blocked_queue_hd, NULL);
2213 (blocked_queue_hd != END_TSO_QUEUE ||
2214 run_queue_hd != END_TSO_QUEUE ||
2215 sleeping_queue != END_TSO_QUEUE);
2219 waitThread(StgTSO *tso, /*out*/StgClosure **ret)
2223 m = stgMallocBytes(sizeof(StgMainThread), "waitThread");
2227 #if defined(RTS_SUPPORTS_THREADS)
2228 initCondition(&m->wakeup);
2231 /* see scheduleWaitThread() comment */
2232 ACQUIRE_LOCK(&sched_mutex);
2233 IF_DEBUG(scheduler, sched_belch("== scheduler: waiting for thread (%d)\n", tso->id));
2234 m->link = main_threads;
2236 RELEASE_LOCK(&sched_mutex);
2238 IF_DEBUG(scheduler, sched_belch("== scheduler: waiting for thread (%d)\n", tso->id));
2239 #if defined(THREADED_RTS)
2240 return waitThread_(m, rtsFalse);
2242 return waitThread_(m);
2248 waitThread_(StgMainThread* m
2249 #if defined(THREADED_RTS)
2250 , rtsBool blockWaiting
2254 SchedulerStatus stat;
2256 IF_DEBUG(scheduler, sched_belch("== scheduler: new main thread (%d)\n", m->tso->id));
2258 #if defined(RTS_SUPPORTS_THREADS)
2260 # if defined(THREADED_RTS)
2261 if (!blockWaiting) {
2262 /* In the threaded case, the OS thread that called main()
2263 * gets to enter the RTS directly without going via another
2267 ASSERT(m->stat != NoStatus);
2271 ACQUIRE_LOCK(&sched_mutex);
2273 waitCondition(&m->wakeup, &sched_mutex);
2274 } while (m->stat == NoStatus);
2277 /* GranSim specific init */
2278 CurrentTSO = m->tso; // the TSO to run
2279 procStatus[MainProc] = Busy; // status of main PE
2280 CurrentProc = MainProc; // PE to run it on
2284 RELEASE_LOCK(&sched_mutex);
2286 ASSERT(m->stat != NoStatus);
2291 #if defined(RTS_SUPPORTS_THREADS)
2292 closeCondition(&m->wakeup);
2295 IF_DEBUG(scheduler, fprintf(stderr, "== scheduler: main thread (%d) finished\n",
2299 #if defined(THREADED_RTS)
2302 RELEASE_LOCK(&sched_mutex);
2307 //@node Run queue code, Garbage Collextion Routines, Suspend and Resume, Main scheduling code
2308 //@subsection Run queue code
2312 NB: In GranSim we have many run queues; run_queue_hd is actually a macro
2313 unfolding to run_queue_hds[CurrentProc], thus CurrentProc is an
2314 implicit global variable that has to be correct when calling these
2318 /* Put the new thread on the head of the runnable queue.
2319 * The caller of createThread better push an appropriate closure
2320 * on this thread's stack before the scheduler is invoked.
2322 static /* inline */ void
2323 add_to_run_queue(tso)
2326 ASSERT(tso!=run_queue_hd && tso!=run_queue_tl);
2327 tso->link = run_queue_hd;
2329 if (run_queue_tl == END_TSO_QUEUE) {
2334 /* Put the new thread at the end of the runnable queue. */
2335 static /* inline */ void
2336 push_on_run_queue(tso)
2339 ASSERT(get_itbl((StgClosure *)tso)->type == TSO);
2340 ASSERT(run_queue_hd!=NULL && run_queue_tl!=NULL);
2341 ASSERT(tso!=run_queue_hd && tso!=run_queue_tl);
2342 if (run_queue_hd == END_TSO_QUEUE) {
2345 run_queue_tl->link = tso;
2351 Should be inlined because it's used very often in schedule. The tso
2352 argument is actually only needed in GranSim, where we want to have the
2353 possibility to schedule *any* TSO on the run queue, irrespective of the
2354 actual ordering. Therefore, if tso is not the nil TSO then we traverse
2355 the run queue and dequeue the tso, adjusting the links in the queue.
2357 //@cindex take_off_run_queue
2358 static /* inline */ StgTSO*
2359 take_off_run_queue(StgTSO *tso) {
2363 qetlaHbogh Qu' ngaSbogh ghomDaQ {tso} yIteq!
2365 if tso is specified, unlink that tso from the run_queue (doesn't have
2366 to be at the beginning of the queue); GranSim only
2368 if (tso!=END_TSO_QUEUE) {
2369 /* find tso in queue */
2370 for (t=run_queue_hd, prev=END_TSO_QUEUE;
2371 t!=END_TSO_QUEUE && t!=tso;
2375 /* now actually dequeue the tso */
2376 if (prev!=END_TSO_QUEUE) {
2377 ASSERT(run_queue_hd!=t);
2378 prev->link = t->link;
2380 /* t is at beginning of thread queue */
2381 ASSERT(run_queue_hd==t);
2382 run_queue_hd = t->link;
2384 /* t is at end of thread queue */
2385 if (t->link==END_TSO_QUEUE) {
2386 ASSERT(t==run_queue_tl);
2387 run_queue_tl = prev;
2389 ASSERT(run_queue_tl!=t);
2391 t->link = END_TSO_QUEUE;
2393 /* take tso from the beginning of the queue; std concurrent code */
2395 if (t != END_TSO_QUEUE) {
2396 run_queue_hd = t->link;
2397 t->link = END_TSO_QUEUE;
2398 if (run_queue_hd == END_TSO_QUEUE) {
2399 run_queue_tl = END_TSO_QUEUE;
2408 //@node Garbage Collextion Routines, Blocking Queue Routines, Run queue code, Main scheduling code
2409 //@subsection Garbage Collextion Routines
2411 /* ---------------------------------------------------------------------------
2412 Where are the roots that we know about?
2414 - all the threads on the runnable queue
2415 - all the threads on the blocked queue
2416 - all the threads on the sleeping queue
2417 - all the thread currently executing a _ccall_GC
2418 - all the "main threads"
2420 ------------------------------------------------------------------------ */
2422 /* This has to be protected either by the scheduler monitor, or by the
2423 garbage collection monitor (probably the latter).
2428 GetRoots(evac_fn evac)
2433 for (i=0; i<=RtsFlags.GranFlags.proc; i++) {
2434 if ((run_queue_hds[i] != END_TSO_QUEUE) && ((run_queue_hds[i] != NULL)))
2435 evac((StgClosure **)&run_queue_hds[i]);
2436 if ((run_queue_tls[i] != END_TSO_QUEUE) && ((run_queue_tls[i] != NULL)))
2437 evac((StgClosure **)&run_queue_tls[i]);
2439 if ((blocked_queue_hds[i] != END_TSO_QUEUE) && ((blocked_queue_hds[i] != NULL)))
2440 evac((StgClosure **)&blocked_queue_hds[i]);
2441 if ((blocked_queue_tls[i] != END_TSO_QUEUE) && ((blocked_queue_tls[i] != NULL)))
2442 evac((StgClosure **)&blocked_queue_tls[i]);
2443 if ((ccalling_threadss[i] != END_TSO_QUEUE) && ((ccalling_threadss[i] != NULL)))
2444 evac((StgClosure **)&ccalling_threads[i]);
2451 if (run_queue_hd != END_TSO_QUEUE) {
2452 ASSERT(run_queue_tl != END_TSO_QUEUE);
2453 evac((StgClosure **)&run_queue_hd);
2454 evac((StgClosure **)&run_queue_tl);
2457 if (blocked_queue_hd != END_TSO_QUEUE) {
2458 ASSERT(blocked_queue_tl != END_TSO_QUEUE);
2459 evac((StgClosure **)&blocked_queue_hd);
2460 evac((StgClosure **)&blocked_queue_tl);
2463 if (sleeping_queue != END_TSO_QUEUE) {
2464 evac((StgClosure **)&sleeping_queue);
2468 if (suspended_ccalling_threads != END_TSO_QUEUE) {
2469 evac((StgClosure **)&suspended_ccalling_threads);
2472 #if defined(PAR) || defined(GRAN)
2473 markSparkQueue(evac);
2476 #ifndef mingw32_TARGET_OS
2477 // mark the signal handlers (signals should be already blocked)
2478 markSignalHandlers(evac);
2481 // main threads which have completed need to be retained until they
2482 // are dealt with in the main scheduler loop. They won't be
2483 // retained any other way: the GC will drop them from the
2484 // all_threads list, so we have to be careful to treat them as roots
2488 for (m = main_threads; m != NULL; m = m->link) {
2489 switch (m->tso->what_next) {
2490 case ThreadComplete:
2492 evac((StgClosure **)&m->tso);
2501 /* -----------------------------------------------------------------------------
2504 This is the interface to the garbage collector from Haskell land.
2505 We provide this so that external C code can allocate and garbage
2506 collect when called from Haskell via _ccall_GC.
2508 It might be useful to provide an interface whereby the programmer
2509 can specify more roots (ToDo).
2511 This needs to be protected by the GC condition variable above. KH.
2512 -------------------------------------------------------------------------- */
2514 static void (*extra_roots)(evac_fn);
2519 /* Obligated to hold this lock upon entry */
2520 ACQUIRE_LOCK(&sched_mutex);
2521 GarbageCollect(GetRoots,rtsFalse);
2522 RELEASE_LOCK(&sched_mutex);
2526 performMajorGC(void)
2528 ACQUIRE_LOCK(&sched_mutex);
2529 GarbageCollect(GetRoots,rtsTrue);
2530 RELEASE_LOCK(&sched_mutex);
2534 AllRoots(evac_fn evac)
2536 GetRoots(evac); // the scheduler's roots
2537 extra_roots(evac); // the user's roots
2541 performGCWithRoots(void (*get_roots)(evac_fn))
2543 ACQUIRE_LOCK(&sched_mutex);
2544 extra_roots = get_roots;
2545 GarbageCollect(AllRoots,rtsFalse);
2546 RELEASE_LOCK(&sched_mutex);
2549 /* -----------------------------------------------------------------------------
2552 If the thread has reached its maximum stack size, then raise the
2553 StackOverflow exception in the offending thread. Otherwise
2554 relocate the TSO into a larger chunk of memory and adjust its stack
2556 -------------------------------------------------------------------------- */
2559 threadStackOverflow(StgTSO *tso)
2561 nat new_stack_size, new_tso_size, diff, stack_words;
2565 IF_DEBUG(sanity,checkTSO(tso));
2566 if (tso->stack_size >= tso->max_stack_size) {
2569 belch("@@ threadStackOverflow of TSO %d (%p): stack too large (now %ld; max is %ld",
2570 tso->id, tso, tso->stack_size, tso->max_stack_size);
2571 /* If we're debugging, just print out the top of the stack */
2572 printStackChunk(tso->sp, stg_min(tso->stack+tso->stack_size,
2575 /* Send this thread the StackOverflow exception */
2576 raiseAsync(tso, (StgClosure *)stackOverflow_closure);
2580 /* Try to double the current stack size. If that takes us over the
2581 * maximum stack size for this thread, then use the maximum instead.
2582 * Finally round up so the TSO ends up as a whole number of blocks.
2584 new_stack_size = stg_min(tso->stack_size * 2, tso->max_stack_size);
2585 new_tso_size = (nat)BLOCK_ROUND_UP(new_stack_size * sizeof(W_) +
2586 TSO_STRUCT_SIZE)/sizeof(W_);
2587 new_tso_size = round_to_mblocks(new_tso_size); /* Be MBLOCK-friendly */
2588 new_stack_size = new_tso_size - TSO_STRUCT_SIZEW;
2590 IF_DEBUG(scheduler, fprintf(stderr,"== scheduler: increasing stack size from %d words to %d.\n", tso->stack_size, new_stack_size));
2592 dest = (StgTSO *)allocate(new_tso_size);
2593 TICK_ALLOC_TSO(new_stack_size,0);
2595 /* copy the TSO block and the old stack into the new area */
2596 memcpy(dest,tso,TSO_STRUCT_SIZE);
2597 stack_words = tso->stack + tso->stack_size - tso->sp;
2598 new_sp = (P_)dest + new_tso_size - stack_words;
2599 memcpy(new_sp, tso->sp, stack_words * sizeof(W_));
2601 /* relocate the stack pointers... */
2602 diff = (P_)new_sp - (P_)tso->sp; /* In *words* */
2603 dest->su = (StgUpdateFrame *) ((P_)dest->su + diff);
2605 dest->stack_size = new_stack_size;
2607 /* and relocate the update frame list */
2608 relocate_stack(dest, diff);
2610 /* Mark the old TSO as relocated. We have to check for relocated
2611 * TSOs in the garbage collector and any primops that deal with TSOs.
2613 * It's important to set the sp and su values to just beyond the end
2614 * of the stack, so we don't attempt to scavenge any part of the
2617 tso->what_next = ThreadRelocated;
2619 tso->sp = (P_)&(tso->stack[tso->stack_size]);
2620 tso->su = (StgUpdateFrame *)tso->sp;
2621 tso->why_blocked = NotBlocked;
2622 dest->mut_link = NULL;
2624 IF_PAR_DEBUG(verbose,
2625 belch("@@ threadStackOverflow of TSO %d (now at %p): stack size increased to %ld",
2626 tso->id, tso, tso->stack_size);
2627 /* If we're debugging, just print out the top of the stack */
2628 printStackChunk(tso->sp, stg_min(tso->stack+tso->stack_size,
2631 IF_DEBUG(sanity,checkTSO(tso));
2633 IF_DEBUG(scheduler,printTSO(dest));
2639 //@node Blocking Queue Routines, Exception Handling Routines, Garbage Collextion Routines, Main scheduling code
2640 //@subsection Blocking Queue Routines
2642 /* ---------------------------------------------------------------------------
2643 Wake up a queue that was blocked on some resource.
2644 ------------------------------------------------------------------------ */
2648 unblockCount ( StgBlockingQueueElement *bqe, StgClosure *node )
2653 unblockCount ( StgBlockingQueueElement *bqe, StgClosure *node )
2655 /* write RESUME events to log file and
2656 update blocked and fetch time (depending on type of the orig closure) */
2657 if (RtsFlags.ParFlags.ParStats.Full) {
2658 DumpRawGranEvent(CURRENT_PROC, CURRENT_PROC,
2659 GR_RESUMEQ, ((StgTSO *)bqe), ((StgTSO *)bqe)->block_info.closure,
2660 0, 0 /* spark_queue_len(ADVISORY_POOL) */);
2661 if (EMPTY_RUN_QUEUE())
2662 emitSchedule = rtsTrue;
2664 switch (get_itbl(node)->type) {
2666 ((StgTSO *)bqe)->par.fetchtime += CURRENT_TIME-((StgTSO *)bqe)->par.blockedat;
2671 ((StgTSO *)bqe)->par.blocktime += CURRENT_TIME-((StgTSO *)bqe)->par.blockedat;
2678 barf("{unblockOneLocked}Daq Qagh: unexpected closure in blocking queue");
2685 static StgBlockingQueueElement *
2686 unblockOneLocked(StgBlockingQueueElement *bqe, StgClosure *node)
2689 PEs node_loc, tso_loc;
2691 node_loc = where_is(node); // should be lifted out of loop
2692 tso = (StgTSO *)bqe; // wastes an assignment to get the type right
2693 tso_loc = where_is((StgClosure *)tso);
2694 if (IS_LOCAL_TO(PROCS(node),tso_loc)) { // TSO is local
2695 /* !fake_fetch => TSO is on CurrentProc is same as IS_LOCAL_TO */
2696 ASSERT(CurrentProc!=node_loc || tso_loc==CurrentProc);
2697 CurrentTime[CurrentProc] += RtsFlags.GranFlags.Costs.lunblocktime;
2698 // insertThread(tso, node_loc);
2699 new_event(tso_loc, tso_loc, CurrentTime[CurrentProc],
2701 tso, node, (rtsSpark*)NULL);
2702 tso->link = END_TSO_QUEUE; // overwrite link just to be sure
2705 } else { // TSO is remote (actually should be FMBQ)
2706 CurrentTime[CurrentProc] += RtsFlags.GranFlags.Costs.mpacktime +
2707 RtsFlags.GranFlags.Costs.gunblocktime +
2708 RtsFlags.GranFlags.Costs.latency;
2709 new_event(tso_loc, CurrentProc, CurrentTime[CurrentProc],
2711 tso, node, (rtsSpark*)NULL);
2712 tso->link = END_TSO_QUEUE; // overwrite link just to be sure
2715 /* the thread-queue-overhead is accounted for in either Resume or UnblockThread */
2717 fprintf(stderr," %s TSO %d (%p) [PE %d] (block_info.closure=%p) (next=%p) ,",
2718 (node_loc==tso_loc ? "Local" : "Global"),
2719 tso->id, tso, CurrentProc, tso->block_info.closure, tso->link));
2720 tso->block_info.closure = NULL;
2721 IF_DEBUG(scheduler,belch("-- Waking up thread %ld (%p)",
2725 static StgBlockingQueueElement *
2726 unblockOneLocked(StgBlockingQueueElement *bqe, StgClosure *node)
2728 StgBlockingQueueElement *next;
2730 switch (get_itbl(bqe)->type) {
2732 ASSERT(((StgTSO *)bqe)->why_blocked != NotBlocked);
2733 /* if it's a TSO just push it onto the run_queue */
2735 // ((StgTSO *)bqe)->link = END_TSO_QUEUE; // debugging?
2736 PUSH_ON_RUN_QUEUE((StgTSO *)bqe);
2738 unblockCount(bqe, node);
2739 /* reset blocking status after dumping event */
2740 ((StgTSO *)bqe)->why_blocked = NotBlocked;
2744 /* if it's a BLOCKED_FETCH put it on the PendingFetches list */
2746 bqe->link = (StgBlockingQueueElement *)PendingFetches;
2747 PendingFetches = (StgBlockedFetch *)bqe;
2751 /* can ignore this case in a non-debugging setup;
2752 see comments on RBHSave closures above */
2754 /* check that the closure is an RBHSave closure */
2755 ASSERT(get_itbl((StgClosure *)bqe) == &stg_RBH_Save_0_info ||
2756 get_itbl((StgClosure *)bqe) == &stg_RBH_Save_1_info ||
2757 get_itbl((StgClosure *)bqe) == &stg_RBH_Save_2_info);
2761 barf("{unblockOneLocked}Daq Qagh: Unexpected IP (%#lx; %s) in blocking queue at %#lx\n",
2762 get_itbl((StgClosure *)bqe), info_type((StgClosure *)bqe),
2766 IF_PAR_DEBUG(bq, fprintf(stderr, ", %p (%s)", bqe, info_type((StgClosure*)bqe)));
2770 #else /* !GRAN && !PAR */
2772 unblockOneLocked(StgTSO *tso)
2776 ASSERT(get_itbl(tso)->type == TSO);
2777 ASSERT(tso->why_blocked != NotBlocked);
2778 tso->why_blocked = NotBlocked;
2780 PUSH_ON_RUN_QUEUE(tso);
2782 IF_DEBUG(scheduler,sched_belch("waking up thread %ld", tso->id));
2787 #if defined(GRAN) || defined(PAR)
2788 inline StgBlockingQueueElement *
2789 unblockOne(StgBlockingQueueElement *bqe, StgClosure *node)
2791 ACQUIRE_LOCK(&sched_mutex);
2792 bqe = unblockOneLocked(bqe, node);
2793 RELEASE_LOCK(&sched_mutex);
2798 unblockOne(StgTSO *tso)
2800 ACQUIRE_LOCK(&sched_mutex);
2801 tso = unblockOneLocked(tso);
2802 RELEASE_LOCK(&sched_mutex);
2809 awakenBlockedQueue(StgBlockingQueueElement *q, StgClosure *node)
2811 StgBlockingQueueElement *bqe;
2816 belch("##-_ AwBQ for node %p on PE %d @ %ld by TSO %d (%p): ", \
2817 node, CurrentProc, CurrentTime[CurrentProc],
2818 CurrentTSO->id, CurrentTSO));
2820 node_loc = where_is(node);
2822 ASSERT(q == END_BQ_QUEUE ||
2823 get_itbl(q)->type == TSO || // q is either a TSO or an RBHSave
2824 get_itbl(q)->type == CONSTR); // closure (type constructor)
2825 ASSERT(is_unique(node));
2827 /* FAKE FETCH: magically copy the node to the tso's proc;
2828 no Fetch necessary because in reality the node should not have been
2829 moved to the other PE in the first place
2831 if (CurrentProc!=node_loc) {
2833 belch("## node %p is on PE %d but CurrentProc is %d (TSO %d); assuming fake fetch and adjusting bitmask (old: %#x)",
2834 node, node_loc, CurrentProc, CurrentTSO->id,
2835 // CurrentTSO, where_is(CurrentTSO),
2836 node->header.gran.procs));
2837 node->header.gran.procs = (node->header.gran.procs) | PE_NUMBER(CurrentProc);
2839 belch("## new bitmask of node %p is %#x",
2840 node, node->header.gran.procs));
2841 if (RtsFlags.GranFlags.GranSimStats.Global) {
2842 globalGranStats.tot_fake_fetches++;
2847 // ToDo: check: ASSERT(CurrentProc==node_loc);
2848 while (get_itbl(bqe)->type==TSO) { // q != END_TSO_QUEUE) {
2851 bqe points to the current element in the queue
2852 next points to the next element in the queue
2854 //tso = (StgTSO *)bqe; // wastes an assignment to get the type right
2855 //tso_loc = where_is(tso);
2857 bqe = unblockOneLocked(bqe, node);
2860 /* if this is the BQ of an RBH, we have to put back the info ripped out of
2861 the closure to make room for the anchor of the BQ */
2862 if (bqe!=END_BQ_QUEUE) {
2863 ASSERT(get_itbl(node)->type == RBH && get_itbl(bqe)->type == CONSTR);
2865 ASSERT((info_ptr==&RBH_Save_0_info) ||
2866 (info_ptr==&RBH_Save_1_info) ||
2867 (info_ptr==&RBH_Save_2_info));
2869 /* cf. convertToRBH in RBH.c for writing the RBHSave closure */
2870 ((StgRBH *)node)->blocking_queue = (StgBlockingQueueElement *)((StgRBHSave *)bqe)->payload[0];
2871 ((StgRBH *)node)->mut_link = (StgMutClosure *)((StgRBHSave *)bqe)->payload[1];
2874 belch("## Filled in RBH_Save for %p (%s) at end of AwBQ",
2875 node, info_type(node)));
2878 /* statistics gathering */
2879 if (RtsFlags.GranFlags.GranSimStats.Global) {
2880 // globalGranStats.tot_bq_processing_time += bq_processing_time;
2881 globalGranStats.tot_bq_len += len; // total length of all bqs awakened
2882 // globalGranStats.tot_bq_len_local += len_local; // same for local TSOs only
2883 globalGranStats.tot_awbq++; // total no. of bqs awakened
2886 fprintf(stderr,"## BQ Stats of %p: [%d entries] %s\n",
2887 node, len, (bqe!=END_BQ_QUEUE) ? "RBH" : ""));
2891 awakenBlockedQueue(StgBlockingQueueElement *q, StgClosure *node)
2893 StgBlockingQueueElement *bqe;
2895 ACQUIRE_LOCK(&sched_mutex);
2897 IF_PAR_DEBUG(verbose,
2898 belch("##-_ AwBQ for node %p on [%x]: ",
2902 if(get_itbl(q)->type == CONSTR || q==END_BQ_QUEUE) {
2903 IF_PAR_DEBUG(verbose, belch("## ... nothing to unblock so lets just return. RFP (BUG?)"));
2908 ASSERT(q == END_BQ_QUEUE ||
2909 get_itbl(q)->type == TSO ||
2910 get_itbl(q)->type == BLOCKED_FETCH ||
2911 get_itbl(q)->type == CONSTR);
2914 while (get_itbl(bqe)->type==TSO ||
2915 get_itbl(bqe)->type==BLOCKED_FETCH) {
2916 bqe = unblockOneLocked(bqe, node);
2918 RELEASE_LOCK(&sched_mutex);
2921 #else /* !GRAN && !PAR */
2923 awakenBlockedQueue(StgTSO *tso)
2925 ACQUIRE_LOCK(&sched_mutex);
2926 while (tso != END_TSO_QUEUE) {
2927 tso = unblockOneLocked(tso);
2929 RELEASE_LOCK(&sched_mutex);
2933 //@node Exception Handling Routines, Debugging Routines, Blocking Queue Routines, Main scheduling code
2934 //@subsection Exception Handling Routines
2936 /* ---------------------------------------------------------------------------
2938 - usually called inside a signal handler so it mustn't do anything fancy.
2939 ------------------------------------------------------------------------ */
2942 interruptStgRts(void)
2948 /* -----------------------------------------------------------------------------
2951 This is for use when we raise an exception in another thread, which
2953 This has nothing to do with the UnblockThread event in GranSim. -- HWL
2954 -------------------------------------------------------------------------- */
2956 #if defined(GRAN) || defined(PAR)
2958 NB: only the type of the blocking queue is different in GranSim and GUM
2959 the operations on the queue-elements are the same
2960 long live polymorphism!
2962 Locks: sched_mutex is held upon entry and exit.
2966 unblockThread(StgTSO *tso)
2968 StgBlockingQueueElement *t, **last;
2970 switch (tso->why_blocked) {
2973 return; /* not blocked */
2976 ASSERT(get_itbl(tso->block_info.closure)->type == MVAR);
2978 StgBlockingQueueElement *last_tso = END_BQ_QUEUE;
2979 StgMVar *mvar = (StgMVar *)(tso->block_info.closure);
2981 last = (StgBlockingQueueElement **)&mvar->head;
2982 for (t = (StgBlockingQueueElement *)mvar->head;
2984 last = &t->link, last_tso = t, t = t->link) {
2985 if (t == (StgBlockingQueueElement *)tso) {
2986 *last = (StgBlockingQueueElement *)tso->link;
2987 if (mvar->tail == tso) {
2988 mvar->tail = (StgTSO *)last_tso;
2993 barf("unblockThread (MVAR): TSO not found");
2996 case BlockedOnBlackHole:
2997 ASSERT(get_itbl(tso->block_info.closure)->type == BLACKHOLE_BQ);
2999 StgBlockingQueue *bq = (StgBlockingQueue *)(tso->block_info.closure);
3001 last = &bq->blocking_queue;
3002 for (t = bq->blocking_queue;
3004 last = &t->link, t = t->link) {
3005 if (t == (StgBlockingQueueElement *)tso) {
3006 *last = (StgBlockingQueueElement *)tso->link;
3010 barf("unblockThread (BLACKHOLE): TSO not found");
3013 case BlockedOnException:
3015 StgTSO *target = tso->block_info.tso;
3017 ASSERT(get_itbl(target)->type == TSO);
3019 if (target->what_next == ThreadRelocated) {
3020 target = target->link;
3021 ASSERT(get_itbl(target)->type == TSO);
3024 ASSERT(target->blocked_exceptions != NULL);
3026 last = (StgBlockingQueueElement **)&target->blocked_exceptions;
3027 for (t = (StgBlockingQueueElement *)target->blocked_exceptions;
3029 last = &t->link, t = t->link) {
3030 ASSERT(get_itbl(t)->type == TSO);
3031 if (t == (StgBlockingQueueElement *)tso) {
3032 *last = (StgBlockingQueueElement *)tso->link;
3036 barf("unblockThread (Exception): TSO not found");
3040 case BlockedOnWrite:
3042 /* take TSO off blocked_queue */
3043 StgBlockingQueueElement *prev = NULL;
3044 for (t = (StgBlockingQueueElement *)blocked_queue_hd; t != END_BQ_QUEUE;
3045 prev = t, t = t->link) {
3046 if (t == (StgBlockingQueueElement *)tso) {
3048 blocked_queue_hd = (StgTSO *)t->link;
3049 if ((StgBlockingQueueElement *)blocked_queue_tl == t) {
3050 blocked_queue_tl = END_TSO_QUEUE;
3053 prev->link = t->link;
3054 if ((StgBlockingQueueElement *)blocked_queue_tl == t) {
3055 blocked_queue_tl = (StgTSO *)prev;
3061 barf("unblockThread (I/O): TSO not found");
3064 case BlockedOnDelay:
3066 /* take TSO off sleeping_queue */
3067 StgBlockingQueueElement *prev = NULL;
3068 for (t = (StgBlockingQueueElement *)sleeping_queue; t != END_BQ_QUEUE;
3069 prev = t, t = t->link) {
3070 if (t == (StgBlockingQueueElement *)tso) {
3072 sleeping_queue = (StgTSO *)t->link;
3074 prev->link = t->link;
3079 barf("unblockThread (I/O): TSO not found");
3083 barf("unblockThread");
3087 tso->link = END_TSO_QUEUE;
3088 tso->why_blocked = NotBlocked;
3089 tso->block_info.closure = NULL;
3090 PUSH_ON_RUN_QUEUE(tso);
3094 unblockThread(StgTSO *tso)
3098 /* To avoid locking unnecessarily. */
3099 if (tso->why_blocked == NotBlocked) {
3103 switch (tso->why_blocked) {
3106 ASSERT(get_itbl(tso->block_info.closure)->type == MVAR);
3108 StgTSO *last_tso = END_TSO_QUEUE;
3109 StgMVar *mvar = (StgMVar *)(tso->block_info.closure);
3112 for (t = mvar->head; t != END_TSO_QUEUE;
3113 last = &t->link, last_tso = t, t = t->link) {
3116 if (mvar->tail == tso) {
3117 mvar->tail = last_tso;
3122 barf("unblockThread (MVAR): TSO not found");
3125 case BlockedOnBlackHole:
3126 ASSERT(get_itbl(tso->block_info.closure)->type == BLACKHOLE_BQ);
3128 StgBlockingQueue *bq = (StgBlockingQueue *)(tso->block_info.closure);
3130 last = &bq->blocking_queue;
3131 for (t = bq->blocking_queue; t != END_TSO_QUEUE;
3132 last = &t->link, t = t->link) {
3138 barf("unblockThread (BLACKHOLE): TSO not found");
3141 case BlockedOnException:
3143 StgTSO *target = tso->block_info.tso;
3145 ASSERT(get_itbl(target)->type == TSO);
3147 while (target->what_next == ThreadRelocated) {
3148 target = target->link;
3149 ASSERT(get_itbl(target)->type == TSO);
3152 ASSERT(target->blocked_exceptions != NULL);
3154 last = &target->blocked_exceptions;
3155 for (t = target->blocked_exceptions; t != END_TSO_QUEUE;
3156 last = &t->link, t = t->link) {
3157 ASSERT(get_itbl(t)->type == TSO);
3163 barf("unblockThread (Exception): TSO not found");
3167 case BlockedOnWrite:
3169 StgTSO *prev = NULL;
3170 for (t = blocked_queue_hd; t != END_TSO_QUEUE;
3171 prev = t, t = t->link) {
3174 blocked_queue_hd = t->link;
3175 if (blocked_queue_tl == t) {
3176 blocked_queue_tl = END_TSO_QUEUE;
3179 prev->link = t->link;
3180 if (blocked_queue_tl == t) {
3181 blocked_queue_tl = prev;
3187 barf("unblockThread (I/O): TSO not found");
3190 case BlockedOnDelay:
3192 StgTSO *prev = NULL;
3193 for (t = sleeping_queue; t != END_TSO_QUEUE;
3194 prev = t, t = t->link) {
3197 sleeping_queue = t->link;
3199 prev->link = t->link;
3204 barf("unblockThread (I/O): TSO not found");
3208 barf("unblockThread");
3212 tso->link = END_TSO_QUEUE;
3213 tso->why_blocked = NotBlocked;
3214 tso->block_info.closure = NULL;
3215 PUSH_ON_RUN_QUEUE(tso);
3219 /* -----------------------------------------------------------------------------
3222 * The following function implements the magic for raising an
3223 * asynchronous exception in an existing thread.
3225 * We first remove the thread from any queue on which it might be
3226 * blocked. The possible blockages are MVARs and BLACKHOLE_BQs.
3228 * We strip the stack down to the innermost CATCH_FRAME, building
3229 * thunks in the heap for all the active computations, so they can
3230 * be restarted if necessary. When we reach a CATCH_FRAME, we build
3231 * an application of the handler to the exception, and push it on
3232 * the top of the stack.
3234 * How exactly do we save all the active computations? We create an
3235 * AP_UPD for every UpdateFrame on the stack. Entering one of these
3236 * AP_UPDs pushes everything from the corresponding update frame
3237 * upwards onto the stack. (Actually, it pushes everything up to the
3238 * next update frame plus a pointer to the next AP_UPD object.
3239 * Entering the next AP_UPD object pushes more onto the stack until we
3240 * reach the last AP_UPD object - at which point the stack should look
3241 * exactly as it did when we killed the TSO and we can continue
3242 * execution by entering the closure on top of the stack.
3244 * We can also kill a thread entirely - this happens if either (a) the
3245 * exception passed to raiseAsync is NULL, or (b) there's no
3246 * CATCH_FRAME on the stack. In either case, we strip the entire
3247 * stack and replace the thread with a zombie.
3249 * Locks: sched_mutex held upon entry nor exit.
3251 * -------------------------------------------------------------------------- */
3254 deleteThread(StgTSO *tso)
3256 raiseAsync(tso,NULL);
3260 raiseAsyncWithLock(StgTSO *tso, StgClosure *exception)
3262 /* When raising async exs from contexts where sched_mutex isn't held;
3263 use raiseAsyncWithLock(). */
3264 ACQUIRE_LOCK(&sched_mutex);
3265 raiseAsync(tso,exception);
3266 RELEASE_LOCK(&sched_mutex);
3270 raiseAsync(StgTSO *tso, StgClosure *exception)
3272 StgUpdateFrame* su = tso->su;
3273 StgPtr sp = tso->sp;
3275 /* Thread already dead? */
3276 if (tso->what_next == ThreadComplete || tso->what_next == ThreadKilled) {
3280 IF_DEBUG(scheduler, sched_belch("raising exception in thread %ld.", tso->id));
3282 /* Remove it from any blocking queues */
3285 /* The stack freezing code assumes there's a closure pointer on
3286 * the top of the stack. This isn't always the case with compiled
3287 * code, so we have to push a dummy closure on the top which just
3288 * returns to the next return address on the stack.
3290 if ( LOOKS_LIKE_GHC_INFO((void*)*sp) ) {
3291 *(--sp) = (W_)&stg_dummy_ret_closure;
3295 nat words = ((P_)su - (P_)sp) - 1;
3299 ASSERT((P_)su > (P_)sp);
3301 /* If we find a CATCH_FRAME, and we've got an exception to raise,
3302 * then build the THUNK raise(exception), and leave it on
3303 * top of the CATCH_FRAME ready to enter.
3305 if (get_itbl(su)->type == CATCH_FRAME && exception != NULL) {
3307 StgCatchFrame *cf = (StgCatchFrame *)su;
3311 /* we've got an exception to raise, so let's pass it to the
3312 * handler in this frame.
3314 raise = (StgClosure *)allocate(sizeofW(StgClosure)+1);
3315 TICK_ALLOC_SE_THK(1,0);
3316 SET_HDR(raise,&stg_raise_info,cf->header.prof.ccs);
3317 raise->payload[0] = exception;
3319 /* throw away the stack from Sp up to the CATCH_FRAME.
3323 /* Ensure that async excpetions are blocked now, so we don't get
3324 * a surprise exception before we get around to executing the
3327 if (tso->blocked_exceptions == NULL) {
3328 tso->blocked_exceptions = END_TSO_QUEUE;
3331 /* Put the newly-built THUNK on top of the stack, ready to execute
3332 * when the thread restarts.
3337 tso->what_next = ThreadEnterGHC;
3338 IF_DEBUG(sanity, checkTSO(tso));
3342 /* First build an AP_UPD consisting of the stack chunk above the
3343 * current update frame, with the top word on the stack as the
3346 ap = (StgAP_UPD *)allocate(AP_sizeW(words));
3349 ap->fun = (StgClosure *)sp[0];
3351 for(i=0; i < (nat)words; ++i) {
3352 ap->payload[i] = (StgClosure *)*sp++;
3355 switch (get_itbl(su)->type) {
3359 SET_HDR(ap,&stg_AP_UPD_info,su->header.prof.ccs /* ToDo */);
3360 TICK_ALLOC_UP_THK(words+1,0);
3363 fprintf(stderr, "scheduler: Updating ");
3364 printPtr((P_)su->updatee);
3365 fprintf(stderr, " with ");
3366 printObj((StgClosure *)ap);
3369 /* Replace the updatee with an indirection - happily
3370 * this will also wake up any threads currently
3371 * waiting on the result.
3373 * Warning: if we're in a loop, more than one update frame on
3374 * the stack may point to the same object. Be careful not to
3375 * overwrite an IND_OLDGEN in this case, because we'll screw
3376 * up the mutable lists. To be on the safe side, don't
3377 * overwrite any kind of indirection at all. See also
3378 * threadSqueezeStack in GC.c, where we have to make a similar
3381 if (!closure_IND(su->updatee)) {
3382 UPD_IND_NOLOCK(su->updatee,ap); /* revert the black hole */
3385 sp += sizeofW(StgUpdateFrame) -1;
3386 sp[0] = (W_)ap; /* push onto stack */
3392 StgCatchFrame *cf = (StgCatchFrame *)su;
3395 /* We want a PAP, not an AP_UPD. Fortunately, the
3396 * layout's the same.
3398 SET_HDR(ap,&stg_PAP_info,su->header.prof.ccs /* ToDo */);
3399 TICK_ALLOC_UPD_PAP(words+1,0);
3401 /* now build o = FUN(catch,ap,handler) */
3402 o = (StgClosure *)allocate(sizeofW(StgClosure)+2);
3403 TICK_ALLOC_FUN(2,0);
3404 SET_HDR(o,&stg_catch_info,su->header.prof.ccs /* ToDo */);
3405 o->payload[0] = (StgClosure *)ap;
3406 o->payload[1] = cf->handler;
3409 fprintf(stderr, "scheduler: Built ");
3410 printObj((StgClosure *)o);
3413 /* pop the old handler and put o on the stack */
3415 sp += sizeofW(StgCatchFrame) - 1;
3422 StgSeqFrame *sf = (StgSeqFrame *)su;
3425 SET_HDR(ap,&stg_PAP_info,su->header.prof.ccs /* ToDo */);
3426 TICK_ALLOC_UPD_PAP(words+1,0);
3428 /* now build o = FUN(seq,ap) */
3429 o = (StgClosure *)allocate(sizeofW(StgClosure)+1);
3430 TICK_ALLOC_SE_THK(1,0);
3431 SET_HDR(o,&stg_seq_info,su->header.prof.ccs /* ToDo */);
3432 o->payload[0] = (StgClosure *)ap;
3435 fprintf(stderr, "scheduler: Built ");
3436 printObj((StgClosure *)o);
3439 /* pop the old handler and put o on the stack */
3441 sp += sizeofW(StgSeqFrame) - 1;
3447 /* We've stripped the entire stack, the thread is now dead. */
3448 sp += sizeofW(StgStopFrame) - 1;
3449 sp[0] = (W_)exception; /* save the exception */
3450 tso->what_next = ThreadKilled;
3451 tso->su = (StgUpdateFrame *)(sp+1);
3462 /* -----------------------------------------------------------------------------
3463 resurrectThreads is called after garbage collection on the list of
3464 threads found to be garbage. Each of these threads will be woken
3465 up and sent a signal: BlockedOnDeadMVar if the thread was blocked
3466 on an MVar, or NonTermination if the thread was blocked on a Black
3469 Locks: sched_mutex isn't held upon entry nor exit.
3470 -------------------------------------------------------------------------- */
3473 resurrectThreads( StgTSO *threads )
3477 for (tso = threads; tso != END_TSO_QUEUE; tso = next) {
3478 next = tso->global_link;
3479 tso->global_link = all_threads;
3481 IF_DEBUG(scheduler, sched_belch("resurrecting thread %d", tso->id));
3483 switch (tso->why_blocked) {
3485 case BlockedOnException:
3486 /* Called by GC - sched_mutex lock is currently held. */
3487 raiseAsync(tso,(StgClosure *)BlockedOnDeadMVar_closure);
3489 case BlockedOnBlackHole:
3490 raiseAsync(tso,(StgClosure *)NonTermination_closure);
3493 /* This might happen if the thread was blocked on a black hole
3494 * belonging to a thread that we've just woken up (raiseAsync
3495 * can wake up threads, remember...).
3499 barf("resurrectThreads: thread blocked in a strange way");
3504 /* -----------------------------------------------------------------------------
3505 * Blackhole detection: if we reach a deadlock, test whether any
3506 * threads are blocked on themselves. Any threads which are found to
3507 * be self-blocked get sent a NonTermination exception.
3509 * This is only done in a deadlock situation in order to avoid
3510 * performance overhead in the normal case.
3512 * Locks: sched_mutex is held upon entry and exit.
3513 * -------------------------------------------------------------------------- */
3516 detectBlackHoles( void )
3518 StgTSO *t = all_threads;
3519 StgUpdateFrame *frame;
3520 StgClosure *blocked_on;
3522 for (t = all_threads; t != END_TSO_QUEUE; t = t->global_link) {
3524 while (t->what_next == ThreadRelocated) {
3526 ASSERT(get_itbl(t)->type == TSO);
3529 if (t->why_blocked != BlockedOnBlackHole) {
3533 blocked_on = t->block_info.closure;
3535 for (frame = t->su; ; frame = frame->link) {
3536 switch (get_itbl(frame)->type) {
3539 if (frame->updatee == blocked_on) {
3540 /* We are blocking on one of our own computations, so
3541 * send this thread the NonTermination exception.
3544 sched_belch("thread %d is blocked on itself", t->id));
3545 raiseAsync(t, (StgClosure *)NonTermination_closure);
3566 //@node Debugging Routines, Index, Exception Handling Routines, Main scheduling code
3567 //@subsection Debugging Routines
3569 /* -----------------------------------------------------------------------------
3570 * Debugging: why is a thread blocked
3571 * [Also provides useful information when debugging threaded programs
3572 * at the Haskell source code level, so enable outside of DEBUG. --sof 7/02]
3573 -------------------------------------------------------------------------- */
3577 printThreadBlockage(StgTSO *tso)
3579 switch (tso->why_blocked) {
3581 fprintf(stderr,"is blocked on read from fd %d", tso->block_info.fd);
3583 case BlockedOnWrite:
3584 fprintf(stderr,"is blocked on write to fd %d", tso->block_info.fd);
3586 case BlockedOnDelay:
3587 fprintf(stderr,"is blocked until %d", tso->block_info.target);
3590 fprintf(stderr,"is blocked on an MVar");
3592 case BlockedOnException:
3593 fprintf(stderr,"is blocked on delivering an exception to thread %d",
3594 tso->block_info.tso->id);
3596 case BlockedOnBlackHole:
3597 fprintf(stderr,"is blocked on a black hole");
3600 fprintf(stderr,"is not blocked");
3604 fprintf(stderr,"is blocked on global address; local FM_BQ is %p (%s)",
3605 tso->block_info.closure, info_type(tso->block_info.closure));
3607 case BlockedOnGA_NoSend:
3608 fprintf(stderr,"is blocked on global address (no send); local FM_BQ is %p (%s)",
3609 tso->block_info.closure, info_type(tso->block_info.closure));
3612 #if defined(RTS_SUPPORTS_THREADS)
3613 case BlockedOnCCall:
3614 fprintf(stderr,"is blocked on an external call");
3618 barf("printThreadBlockage: strange tso->why_blocked: %d for TSO %d (%d)",
3619 tso->why_blocked, tso->id, tso);
3625 printThreadStatus(StgTSO *tso)
3627 switch (tso->what_next) {
3629 fprintf(stderr,"has been killed");
3631 case ThreadComplete:
3632 fprintf(stderr,"has completed");
3635 printThreadBlockage(tso);
3640 printAllThreads(void)
3646 char time_string[TIME_STR_LEN], node_str[NODE_STR_LEN];
3647 ullong_format_string(TIME_ON_PROC(CurrentProc),
3648 time_string, rtsFalse/*no commas!*/);
3650 fprintf(stderr, "all threads at [%s]:\n", time_string);
3652 char time_string[TIME_STR_LEN], node_str[NODE_STR_LEN];
3653 ullong_format_string(CURRENT_TIME,
3654 time_string, rtsFalse/*no commas!*/);
3656 fprintf(stderr,"all threads at [%s]:\n", time_string);
3658 fprintf(stderr,"all threads:\n");
3661 for (t = all_threads; t != END_TSO_QUEUE; t = t->global_link) {
3662 fprintf(stderr, "\tthread %d @ %p ", t->id, (void *)t);
3663 label = lookupThreadLabel((StgWord)t);
3664 if (label) fprintf(stderr,"[\"%s\"] ",(char *)label);
3665 printThreadStatus(t);
3666 fprintf(stderr,"\n");
3673 Print a whole blocking queue attached to node (debugging only).
3678 print_bq (StgClosure *node)
3680 StgBlockingQueueElement *bqe;
3684 fprintf(stderr,"## BQ of closure %p (%s): ",
3685 node, info_type(node));
3687 /* should cover all closures that may have a blocking queue */
3688 ASSERT(get_itbl(node)->type == BLACKHOLE_BQ ||
3689 get_itbl(node)->type == FETCH_ME_BQ ||
3690 get_itbl(node)->type == RBH ||
3691 get_itbl(node)->type == MVAR);
3693 ASSERT(node!=(StgClosure*)NULL); // sanity check
3695 print_bqe(((StgBlockingQueue*)node)->blocking_queue);
3699 Print a whole blocking queue starting with the element bqe.
3702 print_bqe (StgBlockingQueueElement *bqe)
3707 NB: In a parallel setup a BQ of an RBH must end with an RBH_Save closure;
3709 for (end = (bqe==END_BQ_QUEUE);
3710 !end; // iterate until bqe points to a CONSTR
3711 end = (get_itbl(bqe)->type == CONSTR) || (bqe->link==END_BQ_QUEUE),
3712 bqe = end ? END_BQ_QUEUE : bqe->link) {
3713 ASSERT(bqe != END_BQ_QUEUE); // sanity check
3714 ASSERT(bqe != (StgBlockingQueueElement *)NULL); // sanity check
3715 /* types of closures that may appear in a blocking queue */
3716 ASSERT(get_itbl(bqe)->type == TSO ||
3717 get_itbl(bqe)->type == BLOCKED_FETCH ||
3718 get_itbl(bqe)->type == CONSTR);
3719 /* only BQs of an RBH end with an RBH_Save closure */
3720 //ASSERT(get_itbl(bqe)->type != CONSTR || get_itbl(node)->type == RBH);
3722 switch (get_itbl(bqe)->type) {
3724 fprintf(stderr," TSO %u (%x),",
3725 ((StgTSO *)bqe)->id, ((StgTSO *)bqe));
3728 fprintf(stderr," BF (node=%p, ga=((%x, %d, %x)),",
3729 ((StgBlockedFetch *)bqe)->node,
3730 ((StgBlockedFetch *)bqe)->ga.payload.gc.gtid,
3731 ((StgBlockedFetch *)bqe)->ga.payload.gc.slot,
3732 ((StgBlockedFetch *)bqe)->ga.weight);
3735 fprintf(stderr," %s (IP %p),",
3736 (get_itbl(bqe) == &stg_RBH_Save_0_info ? "RBH_Save_0" :
3737 get_itbl(bqe) == &stg_RBH_Save_1_info ? "RBH_Save_1" :
3738 get_itbl(bqe) == &stg_RBH_Save_2_info ? "RBH_Save_2" :
3739 "RBH_Save_?"), get_itbl(bqe));
3742 barf("Unexpected closure type %s in blocking queue", // of %p (%s)",
3743 info_type((StgClosure *)bqe)); // , node, info_type(node));
3747 fputc('\n', stderr);
3749 # elif defined(GRAN)
3751 print_bq (StgClosure *node)
3753 StgBlockingQueueElement *bqe;
3754 PEs node_loc, tso_loc;
3757 /* should cover all closures that may have a blocking queue */
3758 ASSERT(get_itbl(node)->type == BLACKHOLE_BQ ||
3759 get_itbl(node)->type == FETCH_ME_BQ ||
3760 get_itbl(node)->type == RBH);
3762 ASSERT(node!=(StgClosure*)NULL); // sanity check
3763 node_loc = where_is(node);
3765 fprintf(stderr,"## BQ of closure %p (%s) on [PE %d]: ",
3766 node, info_type(node), node_loc);
3769 NB: In a parallel setup a BQ of an RBH must end with an RBH_Save closure;
3771 for (bqe = ((StgBlockingQueue*)node)->blocking_queue, end = (bqe==END_BQ_QUEUE);
3772 !end; // iterate until bqe points to a CONSTR
3773 end = (get_itbl(bqe)->type == CONSTR) || (bqe->link==END_BQ_QUEUE), bqe = end ? END_BQ_QUEUE : bqe->link) {
3774 ASSERT(bqe != END_BQ_QUEUE); // sanity check
3775 ASSERT(bqe != (StgBlockingQueueElement *)NULL); // sanity check
3776 /* types of closures that may appear in a blocking queue */
3777 ASSERT(get_itbl(bqe)->type == TSO ||
3778 get_itbl(bqe)->type == CONSTR);
3779 /* only BQs of an RBH end with an RBH_Save closure */
3780 ASSERT(get_itbl(bqe)->type != CONSTR || get_itbl(node)->type == RBH);
3782 tso_loc = where_is((StgClosure *)bqe);
3783 switch (get_itbl(bqe)->type) {
3785 fprintf(stderr," TSO %d (%p) on [PE %d],",
3786 ((StgTSO *)bqe)->id, (StgTSO *)bqe, tso_loc);
3789 fprintf(stderr," %s (IP %p),",
3790 (get_itbl(bqe) == &stg_RBH_Save_0_info ? "RBH_Save_0" :
3791 get_itbl(bqe) == &stg_RBH_Save_1_info ? "RBH_Save_1" :
3792 get_itbl(bqe) == &stg_RBH_Save_2_info ? "RBH_Save_2" :
3793 "RBH_Save_?"), get_itbl(bqe));
3796 barf("Unexpected closure type %s in blocking queue of %p (%s)",
3797 info_type((StgClosure *)bqe), node, info_type(node));
3801 fputc('\n', stderr);
3805 Nice and easy: only TSOs on the blocking queue
3808 print_bq (StgClosure *node)
3812 ASSERT(node!=(StgClosure*)NULL); // sanity check
3813 for (tso = ((StgBlockingQueue*)node)->blocking_queue;
3814 tso != END_TSO_QUEUE;
3816 ASSERT(tso!=NULL && tso!=END_TSO_QUEUE); // sanity check
3817 ASSERT(get_itbl(tso)->type == TSO); // guess what, sanity check
3818 fprintf(stderr," TSO %d (%p),", tso->id, tso);
3820 fputc('\n', stderr);
3831 for (i=0, tso=run_queue_hd;
3832 tso != END_TSO_QUEUE;
3841 sched_belch(char *s, ...)
3846 fprintf(stderr, "scheduler (task %ld): ", osThreadId());
3848 fprintf(stderr, "== ");
3850 fprintf(stderr, "scheduler: ");
3852 vfprintf(stderr, s, ap);
3853 fprintf(stderr, "\n");
3860 //@node Index, , Debugging Routines, Main scheduling code
3864 //* StgMainThread:: @cindex\s-+StgMainThread
3865 //* awaken_blocked_queue:: @cindex\s-+awaken_blocked_queue
3866 //* blocked_queue_hd:: @cindex\s-+blocked_queue_hd
3867 //* blocked_queue_tl:: @cindex\s-+blocked_queue_tl
3868 //* context_switch:: @cindex\s-+context_switch
3869 //* createThread:: @cindex\s-+createThread
3870 //* gc_pending_cond:: @cindex\s-+gc_pending_cond
3871 //* initScheduler:: @cindex\s-+initScheduler
3872 //* interrupted:: @cindex\s-+interrupted
3873 //* next_thread_id:: @cindex\s-+next_thread_id
3874 //* print_bq:: @cindex\s-+print_bq
3875 //* run_queue_hd:: @cindex\s-+run_queue_hd
3876 //* run_queue_tl:: @cindex\s-+run_queue_tl
3877 //* sched_mutex:: @cindex\s-+sched_mutex
3878 //* schedule:: @cindex\s-+schedule
3879 //* take_off_run_queue:: @cindex\s-+take_off_run_queue
3880 //* term_mutex:: @cindex\s-+term_mutex