1 /* ---------------------------------------------------------------------------
2 * $Id: Schedule.c,v 1.140 2002/04/23 14:20:18 sof 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"
88 #include "StgMiscClosures.h"
90 #include "Interpreter.h"
91 #include "Exception.h"
100 #include "Proftimer.h"
101 #include "ProfHeap.h"
103 #if defined(GRAN) || defined(PAR)
104 # include "GranSimRts.h"
105 # include "GranSim.h"
106 # include "ParallelRts.h"
107 # include "Parallel.h"
108 # include "ParallelDebug.h"
109 # include "FetchMe.h"
113 #include "Capability.h"
114 #include "OSThreads.h"
117 #ifdef HAVE_SYS_TYPES_H
118 #include <sys/types.h>
126 //@node Variables and Data structures, Prototypes, Includes, Main scheduling code
127 //@subsection Variables and Data structures
129 /* Main thread queue.
130 * Locks required: sched_mutex.
132 StgMainThread *main_threads;
135 * Locks required: sched_mutex.
139 StgTSO* ActiveTSO = NULL; /* for assigning system costs; GranSim-Light only */
140 /* rtsTime TimeOfNextEvent, EndOfTimeSlice; now in GranSim.c */
143 In GranSim we have a runnable and a blocked queue for each processor.
144 In order to minimise code changes new arrays run_queue_hds/tls
145 are created. run_queue_hd is then a short cut (macro) for
146 run_queue_hds[CurrentProc] (see GranSim.h).
149 StgTSO *run_queue_hds[MAX_PROC], *run_queue_tls[MAX_PROC];
150 StgTSO *blocked_queue_hds[MAX_PROC], *blocked_queue_tls[MAX_PROC];
151 StgTSO *ccalling_threadss[MAX_PROC];
152 /* We use the same global list of threads (all_threads) in GranSim as in
153 the std RTS (i.e. we are cheating). However, we don't use this list in
154 the GranSim specific code at the moment (so we are only potentially
159 StgTSO *run_queue_hd, *run_queue_tl;
160 StgTSO *blocked_queue_hd, *blocked_queue_tl;
161 StgTSO *sleeping_queue; /* perhaps replace with a hash table? */
165 /* Linked list of all threads.
166 * Used for detecting garbage collected threads.
170 /* When a thread performs a safe C call (_ccall_GC, using old
171 * terminology), it gets put on the suspended_ccalling_threads
172 * list. Used by the garbage collector.
174 static StgTSO *suspended_ccalling_threads;
176 static StgTSO *threadStackOverflow(StgTSO *tso);
178 /* KH: The following two flags are shared memory locations. There is no need
179 to lock them, since they are only unset at the end of a scheduler
183 /* flag set by signal handler to precipitate a context switch */
184 //@cindex context_switch
187 /* if this flag is set as well, give up execution */
188 //@cindex interrupted
191 /* Next thread ID to allocate.
192 * Locks required: sched_mutex
194 //@cindex next_thread_id
195 StgThreadID next_thread_id = 1;
198 * Pointers to the state of the current thread.
199 * Rule of thumb: if CurrentTSO != NULL, then we're running a Haskell
200 * thread. If CurrentTSO == NULL, then we're at the scheduler level.
203 /* The smallest stack size that makes any sense is:
204 * RESERVED_STACK_WORDS (so we can get back from the stack overflow)
205 * + sizeofW(StgStopFrame) (the stg_stop_thread_info frame)
206 * + 1 (the realworld token for an IO thread)
207 * + 1 (the closure to enter)
209 * A thread with this stack will bomb immediately with a stack
210 * overflow, which will increase its stack size.
213 #define MIN_STACK_WORDS (RESERVED_STACK_WORDS + sizeofW(StgStopFrame) + 2)
220 /* This is used in `TSO.h' and gcc 2.96 insists that this variable actually
221 * exists - earlier gccs apparently didn't.
228 void addToBlockedQueue ( StgTSO *tso );
230 static void schedule ( void );
231 void interruptStgRts ( void );
233 static StgTSO * createThread_ ( nat size, rtsBool have_lock, StgInt pri );
235 static StgTSO * createThread_ ( nat size, rtsBool have_lock );
238 static void detectBlackHoles ( void );
241 static void sched_belch(char *s, ...);
244 #if defined(RTS_SUPPORTS_THREADS)
245 /* ToDo: carefully document the invariants that go together
246 * with these synchronisation objects.
248 Mutex sched_mutex = INIT_MUTEX_VAR;
249 Mutex term_mutex = INIT_MUTEX_VAR;
252 static Condition gc_pending_cond = INIT_COND_VAR;
256 #endif /* RTS_SUPPORTS_THREADS */
260 rtsTime TimeOfLastYield;
261 rtsBool emitSchedule = rtsTrue;
265 char *whatNext_strs[] = {
273 char *threadReturnCode_strs[] = {
274 "HeapOverflow", /* might also be StackOverflow */
283 StgTSO * createSparkThread(rtsSpark spark);
284 StgTSO * activateSpark (rtsSpark spark);
288 * The thread state for the main thread.
289 // ToDo: check whether not needed any more
293 #if defined(PAR) || defined(RTS_SUPPORTS_THREADS)
294 static void taskStart(void);
305 //@node Main scheduling loop, Suspend and Resume, Prototypes, Main scheduling code
306 //@subsection Main scheduling loop
308 /* ---------------------------------------------------------------------------
309 Main scheduling loop.
311 We use round-robin scheduling, each thread returning to the
312 scheduler loop when one of these conditions is detected:
315 * timer expires (thread yields)
320 Locking notes: we acquire the scheduler lock once at the beginning
321 of the scheduler loop, and release it when
323 * running a thread, or
324 * waiting for work, or
325 * waiting for a GC to complete.
328 In a GranSim setup this loop iterates over the global event queue.
329 This revolves around the global event queue, which determines what
330 to do next. Therefore, it's more complicated than either the
331 concurrent or the parallel (GUM) setup.
334 GUM iterates over incoming messages.
335 It starts with nothing to do (thus CurrentTSO == END_TSO_QUEUE),
336 and sends out a fish whenever it has nothing to do; in-between
337 doing the actual reductions (shared code below) it processes the
338 incoming messages and deals with delayed operations
339 (see PendingFetches).
340 This is not the ugliest code you could imagine, but it's bloody close.
342 ------------------------------------------------------------------------ */
349 StgThreadReturnCode ret;
357 rtsBool receivedFinish = rtsFalse;
359 nat tp_size, sp_size; // stats only
362 rtsBool was_interrupted = rtsFalse;
364 ACQUIRE_LOCK(&sched_mutex);
366 #if defined(RTS_SUPPORTS_THREADS)
367 waitForWorkCapability(&sched_mutex, &cap, rtsFalse);
369 /* simply initialise it in the non-threaded case */
370 grabCapability(&cap);
374 /* set up first event to get things going */
375 /* ToDo: assign costs for system setup and init MainTSO ! */
376 new_event(CurrentProc, CurrentProc, CurrentTime[CurrentProc],
378 CurrentTSO, (StgClosure*)NULL, (rtsSpark*)NULL);
381 fprintf(stderr, "GRAN: Init CurrentTSO (in schedule) = %p\n", CurrentTSO);
382 G_TSO(CurrentTSO, 5));
384 if (RtsFlags.GranFlags.Light) {
385 /* Save current time; GranSim Light only */
386 CurrentTSO->gran.clock = CurrentTime[CurrentProc];
389 event = get_next_event();
391 while (event!=(rtsEvent*)NULL) {
392 /* Choose the processor with the next event */
393 CurrentProc = event->proc;
394 CurrentTSO = event->tso;
398 while (!receivedFinish) { /* set by processMessages */
399 /* when receiving PP_FINISH message */
406 IF_DEBUG(scheduler, printAllThreads());
408 #if defined(RTS_SUPPORTS_THREADS)
409 /* Check to see whether there are any worker threads
410 waiting to deposit external call results. If so,
411 yield our capability */
412 yieldToReturningWorker(&sched_mutex, &cap);
415 /* If we're interrupted (the user pressed ^C, or some other
416 * termination condition occurred), kill all the currently running
420 IF_DEBUG(scheduler, sched_belch("interrupted"));
422 interrupted = rtsFalse;
423 was_interrupted = rtsTrue;
426 /* Go through the list of main threads and wake up any
427 * clients whose computations have finished. ToDo: this
428 * should be done more efficiently without a linear scan
429 * of the main threads list, somehow...
431 #if defined(RTS_SUPPORTS_THREADS)
433 StgMainThread *m, **prev;
434 prev = &main_threads;
435 for (m = main_threads; m != NULL; m = m->link) {
436 switch (m->tso->what_next) {
439 *(m->ret) = (StgClosure *)m->tso->sp[0];
443 broadcastCondition(&m->wakeup);
446 m->tso->label = NULL;
450 if (m->ret) *(m->ret) = NULL;
452 if (was_interrupted) {
453 m->stat = Interrupted;
457 broadcastCondition(&m->wakeup);
460 m->tso->label = NULL;
469 #else /* not threaded */
472 /* in GUM do this only on the Main PE */
475 /* If our main thread has finished or been killed, return.
478 StgMainThread *m = main_threads;
479 if (m->tso->what_next == ThreadComplete
480 || m->tso->what_next == ThreadKilled) {
483 m->tso->label = NULL;
485 main_threads = main_threads->link;
486 if (m->tso->what_next == ThreadComplete) {
487 /* we finished successfully, fill in the return value */
488 if (m->ret) { *(m->ret) = (StgClosure *)m->tso->sp[0]; };
492 if (m->ret) { *(m->ret) = NULL; };
493 if (was_interrupted) {
494 m->stat = Interrupted;
504 /* Top up the run queue from our spark pool. We try to make the
505 * number of threads in the run queue equal to the number of
508 * Disable spark support in SMP for now, non-essential & requires
509 * a little bit of work to make it compile cleanly. -- sof 1/02.
511 #if 0 /* defined(SMP) */
513 nat n = getFreeCapabilities();
514 StgTSO *tso = run_queue_hd;
516 /* Count the run queue */
517 while (n > 0 && tso != END_TSO_QUEUE) {
524 spark = findSpark(rtsFalse);
526 break; /* no more sparks in the pool */
528 /* I'd prefer this to be done in activateSpark -- HWL */
529 /* tricky - it needs to hold the scheduler lock and
530 * not try to re-acquire it -- SDM */
531 createSparkThread(spark);
533 sched_belch("==^^ turning spark of closure %p into a thread",
534 (StgClosure *)spark));
537 /* We need to wake up the other tasks if we just created some
540 if (getFreeCapabilities() - n > 1) {
541 signalCondition( &thread_ready_cond );
546 /* check for signals each time around the scheduler */
547 #ifndef mingw32_TARGET_OS
548 if (signals_pending()) {
549 RELEASE_LOCK(&sched_mutex); /* ToDo: kill */
550 startSignalHandlers();
551 ACQUIRE_LOCK(&sched_mutex);
555 /* Check whether any waiting threads need to be woken up. If the
556 * run queue is empty, and there are no other tasks running, we
557 * can wait indefinitely for something to happen.
558 * ToDo: what if another client comes along & requests another
561 if ( !EMPTY_QUEUE(blocked_queue_hd) || !EMPTY_QUEUE(sleeping_queue) ) {
562 awaitEvent( EMPTY_RUN_QUEUE()
564 && allFreeCapabilities()
568 /* we can be interrupted while waiting for I/O... */
569 if (interrupted) continue;
572 * Detect deadlock: when we have no threads to run, there are no
573 * threads waiting on I/O or sleeping, and all the other tasks are
574 * waiting for work, we must have a deadlock of some description.
576 * We first try to find threads blocked on themselves (ie. black
577 * holes), and generate NonTermination exceptions where necessary.
579 * If no threads are black holed, we have a deadlock situation, so
580 * inform all the main threads.
583 if ( EMPTY_THREAD_QUEUES()
584 #if defined(RTS_SUPPORTS_THREADS)
585 && EMPTY_QUEUE(suspended_ccalling_threads)
588 && allFreeCapabilities()
592 IF_DEBUG(scheduler, sched_belch("deadlocked, forcing major GC..."));
593 #if defined(THREADED_RTS)
594 /* and SMP mode ..? */
595 releaseCapability(cap);
597 // Garbage collection can release some new threads due to
598 // either (a) finalizers or (b) threads resurrected because
599 // they are about to be send BlockedOnDeadMVar. Any threads
600 // thus released will be immediately runnable.
601 GarbageCollect(GetRoots,rtsTrue);
603 if ( !EMPTY_RUN_QUEUE() ) { goto not_deadlocked; }
606 sched_belch("still deadlocked, checking for black holes..."));
609 if ( !EMPTY_RUN_QUEUE() ) { goto not_deadlocked; }
611 #ifndef mingw32_TARGET_OS
612 /* If we have user-installed signal handlers, then wait
613 * for signals to arrive rather then bombing out with a
616 #if defined(RTS_SUPPORTS_THREADS)
617 if ( 0 ) { /* hmm..what to do? Simply stop waiting for
618 a signal with no runnable threads (or I/O
619 suspended ones) leads nowhere quick.
620 For now, simply shut down when we reach this
623 ToDo: define precisely under what conditions
624 the Scheduler should shut down in an MT setting.
627 if ( anyUserHandlers() ) {
630 sched_belch("still deadlocked, waiting for signals..."));
634 // we might be interrupted...
635 if (interrupted) { continue; }
637 if (signals_pending()) {
638 RELEASE_LOCK(&sched_mutex);
639 startSignalHandlers();
640 ACQUIRE_LOCK(&sched_mutex);
642 ASSERT(!EMPTY_RUN_QUEUE());
647 /* Probably a real deadlock. Send the current main thread the
648 * Deadlock exception (or in the SMP build, send *all* main
649 * threads the deadlock exception, since none of them can make
654 #if defined(RTS_SUPPORTS_THREADS)
655 for (m = main_threads; m != NULL; m = m->link) {
656 switch (m->tso->why_blocked) {
657 case BlockedOnBlackHole:
658 raiseAsync(m->tso, (StgClosure *)NonTermination_closure);
660 case BlockedOnException:
662 raiseAsync(m->tso, (StgClosure *)Deadlock_closure);
665 barf("deadlock: main thread blocked in a strange way");
670 switch (m->tso->why_blocked) {
671 case BlockedOnBlackHole:
672 raiseAsync(m->tso, (StgClosure *)NonTermination_closure);
674 case BlockedOnException:
676 raiseAsync(m->tso, (StgClosure *)Deadlock_closure);
679 barf("deadlock: main thread blocked in a strange way");
684 #if defined(RTS_SUPPORTS_THREADS)
685 /* ToDo: revisit conditions (and mechanism) for shutting
686 down a multi-threaded world */
687 IF_DEBUG(scheduler, sched_belch("all done, i think...shutting down."));
688 shutdownHaskellAndExit(0);
694 /* ToDo: add deadlock detection in GUM (similar to SMP) -- HWL */
698 /* If there's a GC pending, don't do anything until it has
702 IF_DEBUG(scheduler,sched_belch("waiting for GC"));
703 waitCondition( &gc_pending_cond, &sched_mutex );
707 #if defined(RTS_SUPPORTS_THREADS)
708 /* block until we've got a thread on the run queue and a free
712 if ( EMPTY_RUN_QUEUE() ) {
713 /* Give up our capability */
714 releaseCapability(cap);
715 IF_DEBUG(scheduler, sched_belch("thread %d: waiting for work", osThreadId()));
716 waitForWorkCapability(&sched_mutex, &cap, rtsTrue);
717 IF_DEBUG(scheduler, sched_belch("thread %d: work now available", osThreadId()));
719 while ( EMPTY_RUN_QUEUE() ) {
720 waitForWorkCapability(&sched_mutex, &cap);
721 IF_DEBUG(scheduler, sched_belch("thread %d: work now available", osThreadId()));
728 if (RtsFlags.GranFlags.Light)
729 GranSimLight_enter_system(event, &ActiveTSO); // adjust ActiveTSO etc
731 /* adjust time based on time-stamp */
732 if (event->time > CurrentTime[CurrentProc] &&
733 event->evttype != ContinueThread)
734 CurrentTime[CurrentProc] = event->time;
736 /* Deal with the idle PEs (may issue FindWork or MoveSpark events) */
737 if (!RtsFlags.GranFlags.Light)
740 IF_DEBUG(gran, fprintf(stderr, "GRAN: switch by event-type\n"));
742 /* main event dispatcher in GranSim */
743 switch (event->evttype) {
744 /* Should just be continuing execution */
746 IF_DEBUG(gran, fprintf(stderr, "GRAN: doing ContinueThread\n"));
747 /* ToDo: check assertion
748 ASSERT(run_queue_hd != (StgTSO*)NULL &&
749 run_queue_hd != END_TSO_QUEUE);
751 /* Ignore ContinueThreads for fetching threads (if synchr comm) */
752 if (!RtsFlags.GranFlags.DoAsyncFetch &&
753 procStatus[CurrentProc]==Fetching) {
754 belch("ghuH: Spurious ContinueThread while Fetching ignored; TSO %d (%p) [PE %d]",
755 CurrentTSO->id, CurrentTSO, CurrentProc);
758 /* Ignore ContinueThreads for completed threads */
759 if (CurrentTSO->what_next == ThreadComplete) {
760 belch("ghuH: found a ContinueThread event for completed thread %d (%p) [PE %d] (ignoring ContinueThread)",
761 CurrentTSO->id, CurrentTSO, CurrentProc);
764 /* Ignore ContinueThreads for threads that are being migrated */
765 if (PROCS(CurrentTSO)==Nowhere) {
766 belch("ghuH: trying to run the migrating TSO %d (%p) [PE %d] (ignoring ContinueThread)",
767 CurrentTSO->id, CurrentTSO, CurrentProc);
770 /* The thread should be at the beginning of the run queue */
771 if (CurrentTSO!=run_queue_hds[CurrentProc]) {
772 belch("ghuH: TSO %d (%p) [PE %d] is not at the start of the run_queue when doing a ContinueThread",
773 CurrentTSO->id, CurrentTSO, CurrentProc);
774 break; // run the thread anyway
777 new_event(proc, proc, CurrentTime[proc],
779 (StgTSO*)NULL, (StgClosure*)NULL, (rtsSpark*)NULL);
781 */ /* Catches superfluous CONTINUEs -- should be unnecessary */
782 break; // now actually run the thread; DaH Qu'vam yImuHbej
785 do_the_fetchnode(event);
786 goto next_thread; /* handle next event in event queue */
789 do_the_globalblock(event);
790 goto next_thread; /* handle next event in event queue */
793 do_the_fetchreply(event);
794 goto next_thread; /* handle next event in event queue */
796 case UnblockThread: /* Move from the blocked queue to the tail of */
797 do_the_unblock(event);
798 goto next_thread; /* handle next event in event queue */
800 case ResumeThread: /* Move from the blocked queue to the tail of */
801 /* the runnable queue ( i.e. Qu' SImqa'lu') */
802 event->tso->gran.blocktime +=
803 CurrentTime[CurrentProc] - event->tso->gran.blockedat;
804 do_the_startthread(event);
805 goto next_thread; /* handle next event in event queue */
808 do_the_startthread(event);
809 goto next_thread; /* handle next event in event queue */
812 do_the_movethread(event);
813 goto next_thread; /* handle next event in event queue */
816 do_the_movespark(event);
817 goto next_thread; /* handle next event in event queue */
820 do_the_findwork(event);
821 goto next_thread; /* handle next event in event queue */
824 barf("Illegal event type %u\n", event->evttype);
827 /* This point was scheduler_loop in the old RTS */
829 IF_DEBUG(gran, belch("GRAN: after main switch"));
831 TimeOfLastEvent = CurrentTime[CurrentProc];
832 TimeOfNextEvent = get_time_of_next_event();
833 IgnoreEvents=(TimeOfNextEvent==0); // HWL HACK
834 // CurrentTSO = ThreadQueueHd;
836 IF_DEBUG(gran, belch("GRAN: time of next event is: %ld",
839 if (RtsFlags.GranFlags.Light)
840 GranSimLight_leave_system(event, &ActiveTSO);
842 EndOfTimeSlice = CurrentTime[CurrentProc]+RtsFlags.GranFlags.time_slice;
845 belch("GRAN: end of time-slice is %#lx", EndOfTimeSlice));
847 /* in a GranSim setup the TSO stays on the run queue */
849 /* Take a thread from the run queue. */
850 t = POP_RUN_QUEUE(); // take_off_run_queue(t);
853 fprintf(stderr, "GRAN: About to run current thread, which is\n");
856 context_switch = 0; // turned on via GranYield, checking events and time slice
859 DumpGranEvent(GR_SCHEDULE, t));
861 procStatus[CurrentProc] = Busy;
864 if (PendingFetches != END_BF_QUEUE) {
868 /* ToDo: phps merge with spark activation above */
869 /* check whether we have local work and send requests if we have none */
870 if (EMPTY_RUN_QUEUE()) { /* no runnable threads */
871 /* :-[ no local threads => look out for local sparks */
872 /* the spark pool for the current PE */
873 pool = &(MainRegTable.rSparks); // generalise to cap = &MainRegTable
874 if (advisory_thread_count < RtsFlags.ParFlags.maxThreads &&
875 pool->hd < pool->tl) {
877 * ToDo: add GC code check that we really have enough heap afterwards!!
879 * If we're here (no runnable threads) and we have pending
880 * sparks, we must have a space problem. Get enough space
881 * to turn one of those pending sparks into a
885 spark = findSpark(rtsFalse); /* get a spark */
886 if (spark != (rtsSpark) NULL) {
887 tso = activateSpark(spark); /* turn the spark into a thread */
888 IF_PAR_DEBUG(schedule,
889 belch("==== schedule: Created TSO %d (%p); %d threads active",
890 tso->id, tso, advisory_thread_count));
892 if (tso==END_TSO_QUEUE) { /* failed to activate spark->back to loop */
893 belch("==^^ failed to activate spark");
895 } /* otherwise fall through & pick-up new tso */
897 IF_PAR_DEBUG(verbose,
898 belch("==^^ no local sparks (spark pool contains only NFs: %d)",
899 spark_queue_len(pool)));
904 /* If we still have no work we need to send a FISH to get a spark
907 if (EMPTY_RUN_QUEUE()) {
908 /* =8-[ no local sparks => look for work on other PEs */
910 * We really have absolutely no work. Send out a fish
911 * (there may be some out there already), and wait for
912 * something to arrive. We clearly can't run any threads
913 * until a SCHEDULE or RESUME arrives, and so that's what
914 * we're hoping to see. (Of course, we still have to
915 * respond to other types of messages.)
917 TIME now = msTime() /*CURRENT_TIME*/;
918 IF_PAR_DEBUG(verbose,
919 belch("-- now=%ld", now));
920 IF_PAR_DEBUG(verbose,
921 if (outstandingFishes < RtsFlags.ParFlags.maxFishes &&
922 (last_fish_arrived_at!=0 &&
923 last_fish_arrived_at+RtsFlags.ParFlags.fishDelay > now)) {
924 belch("--$$ delaying FISH until %ld (last fish %ld, delay %ld, now %ld)",
925 last_fish_arrived_at+RtsFlags.ParFlags.fishDelay,
926 last_fish_arrived_at,
927 RtsFlags.ParFlags.fishDelay, now);
930 if (outstandingFishes < RtsFlags.ParFlags.maxFishes &&
931 (last_fish_arrived_at==0 ||
932 (last_fish_arrived_at+RtsFlags.ParFlags.fishDelay <= now))) {
933 /* outstandingFishes is set in sendFish, processFish;
934 avoid flooding system with fishes via delay */
936 sendFish(pe, mytid, NEW_FISH_AGE, NEW_FISH_HISTORY,
939 // Global statistics: count no. of fishes
940 if (RtsFlags.ParFlags.ParStats.Global &&
941 RtsFlags.GcFlags.giveStats > NO_GC_STATS) {
942 globalParStats.tot_fish_mess++;
946 receivedFinish = processMessages();
949 } else if (PacketsWaiting()) { /* Look for incoming messages */
950 receivedFinish = processMessages();
953 /* Now we are sure that we have some work available */
954 ASSERT(run_queue_hd != END_TSO_QUEUE);
956 /* Take a thread from the run queue, if we have work */
957 t = POP_RUN_QUEUE(); // take_off_run_queue(END_TSO_QUEUE);
958 IF_DEBUG(sanity,checkTSO(t));
960 /* ToDo: write something to the log-file
961 if (RTSflags.ParFlags.granSimStats && !sameThread)
962 DumpGranEvent(GR_SCHEDULE, RunnableThreadsHd);
966 /* the spark pool for the current PE */
967 pool = &(MainRegTable.rSparks); // generalise to cap = &MainRegTable
970 belch("--=^ %d threads, %d sparks on [%#x]",
971 run_queue_len(), spark_queue_len(pool), CURRENT_PROC));
974 if (0 && RtsFlags.ParFlags.ParStats.Full &&
975 t && LastTSO && t->id != LastTSO->id &&
976 LastTSO->why_blocked == NotBlocked &&
977 LastTSO->what_next != ThreadComplete) {
978 // if previously scheduled TSO not blocked we have to record the context switch
979 DumpVeryRawGranEvent(TimeOfLastYield, CURRENT_PROC, CURRENT_PROC,
980 GR_DESCHEDULE, LastTSO, (StgClosure *)NULL, 0, 0);
983 if (RtsFlags.ParFlags.ParStats.Full &&
984 (emitSchedule /* forced emit */ ||
985 (t && LastTSO && t->id != LastTSO->id))) {
987 we are running a different TSO, so write a schedule event to log file
988 NB: If we use fair scheduling we also have to write a deschedule
989 event for LastTSO; with unfair scheduling we know that the
990 previous tso has blocked whenever we switch to another tso, so
991 we don't need it in GUM for now
993 DumpRawGranEvent(CURRENT_PROC, CURRENT_PROC,
994 GR_SCHEDULE, t, (StgClosure *)NULL, 0, 0);
995 emitSchedule = rtsFalse;
999 #else /* !GRAN && !PAR */
1001 /* grab a thread from the run queue */
1002 ASSERT(run_queue_hd != END_TSO_QUEUE);
1003 t = POP_RUN_QUEUE();
1004 // Sanity check the thread we're about to run. This can be
1005 // expensive if there is lots of thread switching going on...
1006 IF_DEBUG(sanity,checkTSO(t));
1009 cap->r.rCurrentTSO = t;
1011 /* context switches are now initiated by the timer signal, unless
1012 * the user specified "context switch as often as possible", with
1017 RtsFlags.ProfFlags.profileInterval == 0 ||
1019 (RtsFlags.ConcFlags.ctxtSwitchTicks == 0
1020 && (run_queue_hd != END_TSO_QUEUE
1021 || blocked_queue_hd != END_TSO_QUEUE
1022 || sleeping_queue != END_TSO_QUEUE)))
1027 RELEASE_LOCK(&sched_mutex);
1029 IF_DEBUG(scheduler, sched_belch("-->> Running TSO %ld (%p) %s ...",
1030 t->id, t, whatNext_strs[t->what_next]));
1033 startHeapProfTimer();
1036 /* +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ */
1037 /* Run the current thread
1039 switch (cap->r.rCurrentTSO->what_next) {
1041 case ThreadComplete:
1042 /* Thread already finished, return to scheduler. */
1043 ret = ThreadFinished;
1045 case ThreadEnterGHC:
1046 ret = StgRun((StgFunPtr) stg_enterStackTop, &cap->r);
1049 ret = StgRun((StgFunPtr) stg_returnToStackTop, &cap->r);
1051 case ThreadEnterInterp:
1052 ret = interpretBCO(cap);
1055 barf("schedule: invalid what_next field");
1057 /* +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ */
1059 /* Costs for the scheduler are assigned to CCS_SYSTEM */
1061 stopHeapProfTimer();
1065 ACQUIRE_LOCK(&sched_mutex);
1068 IF_DEBUG(scheduler,fprintf(stderr,"scheduler (task %ld): ", osThreadId()););
1069 #elif !defined(GRAN) && !defined(PAR)
1070 IF_DEBUG(scheduler,fprintf(stderr,"scheduler: "););
1072 t = cap->r.rCurrentTSO;
1075 /* HACK 675: if the last thread didn't yield, make sure to print a
1076 SCHEDULE event to the log file when StgRunning the next thread, even
1077 if it is the same one as before */
1079 TimeOfLastYield = CURRENT_TIME;
1085 IF_DEBUG(gran, DumpGranEvent(GR_DESCHEDULE, t));
1086 globalGranStats.tot_heapover++;
1088 globalParStats.tot_heapover++;
1091 // did the task ask for a large block?
1092 if (cap->r.rHpAlloc > BLOCK_SIZE_W) {
1093 // if so, get one and push it on the front of the nursery.
1097 blocks = (nat)BLOCK_ROUND_UP(cap->r.rHpAlloc * sizeof(W_)) / BLOCK_SIZE;
1099 IF_DEBUG(scheduler,belch("--<< thread %ld (%p; %s) stopped: requesting a large block (size %d)",
1101 whatNext_strs[t->what_next], blocks));
1103 // don't do this if it would push us over the
1104 // alloc_blocks_lim limit; we'll GC first.
1105 if (alloc_blocks + blocks < alloc_blocks_lim) {
1107 alloc_blocks += blocks;
1108 bd = allocGroup( blocks );
1110 // link the new group into the list
1111 bd->link = cap->r.rCurrentNursery;
1112 bd->u.back = cap->r.rCurrentNursery->u.back;
1113 if (cap->r.rCurrentNursery->u.back != NULL) {
1114 cap->r.rCurrentNursery->u.back->link = bd;
1116 ASSERT(g0s0->blocks == cap->r.rCurrentNursery &&
1117 g0s0->blocks == cap->r.rNursery);
1118 cap->r.rNursery = g0s0->blocks = bd;
1120 cap->r.rCurrentNursery->u.back = bd;
1122 // initialise it as a nursery block
1126 bd->free = bd->start;
1128 // don't forget to update the block count in g0s0.
1129 g0s0->n_blocks += blocks;
1130 ASSERT(countBlocks(g0s0->blocks) == g0s0->n_blocks);
1132 // now update the nursery to point to the new block
1133 cap->r.rCurrentNursery = bd;
1135 // we might be unlucky and have another thread get on the
1136 // run queue before us and steal the large block, but in that
1137 // case the thread will just end up requesting another large
1139 PUSH_ON_RUN_QUEUE(t);
1144 /* make all the running tasks block on a condition variable,
1145 * maybe set context_switch and wait till they all pile in,
1146 * then have them wait on a GC condition variable.
1148 IF_DEBUG(scheduler,belch("--<< thread %ld (%p; %s) stopped: HeapOverflow",
1149 t->id, t, whatNext_strs[t->what_next]));
1152 ASSERT(!is_on_queue(t,CurrentProc));
1154 /* Currently we emit a DESCHEDULE event before GC in GUM.
1155 ToDo: either add separate event to distinguish SYSTEM time from rest
1156 or just nuke this DESCHEDULE (and the following SCHEDULE) */
1157 if (0 && RtsFlags.ParFlags.ParStats.Full) {
1158 DumpRawGranEvent(CURRENT_PROC, CURRENT_PROC,
1159 GR_DESCHEDULE, t, (StgClosure *)NULL, 0, 0);
1160 emitSchedule = rtsTrue;
1164 ready_to_gc = rtsTrue;
1165 context_switch = 1; /* stop other threads ASAP */
1166 PUSH_ON_RUN_QUEUE(t);
1167 /* actual GC is done at the end of the while loop */
1173 DumpGranEvent(GR_DESCHEDULE, t));
1174 globalGranStats.tot_stackover++;
1177 // DumpGranEvent(GR_DESCHEDULE, t);
1178 globalParStats.tot_stackover++;
1180 IF_DEBUG(scheduler,belch("--<< thread %ld (%p; %s) stopped, StackOverflow",
1181 t->id, t, whatNext_strs[t->what_next]));
1182 /* just adjust the stack for this thread, then pop it back
1188 /* enlarge the stack */
1189 StgTSO *new_t = threadStackOverflow(t);
1191 /* This TSO has moved, so update any pointers to it from the
1192 * main thread stack. It better not be on any other queues...
1193 * (it shouldn't be).
1195 for (m = main_threads; m != NULL; m = m->link) {
1200 threadPaused(new_t);
1201 PUSH_ON_RUN_QUEUE(new_t);
1205 case ThreadYielding:
1208 DumpGranEvent(GR_DESCHEDULE, t));
1209 globalGranStats.tot_yields++;
1212 // DumpGranEvent(GR_DESCHEDULE, t);
1213 globalParStats.tot_yields++;
1215 /* put the thread back on the run queue. Then, if we're ready to
1216 * GC, check whether this is the last task to stop. If so, wake
1217 * up the GC thread. getThread will block during a GC until the
1221 if (t->what_next == ThreadEnterInterp) {
1222 /* ToDo: or maybe a timer expired when we were in Hugs?
1223 * or maybe someone hit ctrl-C
1225 belch("--<< thread %ld (%p; %s) stopped to switch to Hugs",
1226 t->id, t, whatNext_strs[t->what_next]);
1228 belch("--<< thread %ld (%p; %s) stopped, yielding",
1229 t->id, t, whatNext_strs[t->what_next]);
1236 //belch("&& Doing sanity check on yielding TSO %ld.", t->id);
1238 ASSERT(t->link == END_TSO_QUEUE);
1240 ASSERT(!is_on_queue(t,CurrentProc));
1243 //belch("&& Doing sanity check on all ThreadQueues (and their TSOs).");
1244 checkThreadQsSanity(rtsTrue));
1247 if (RtsFlags.ParFlags.doFairScheduling) {
1248 /* this does round-robin scheduling; good for concurrency */
1249 APPEND_TO_RUN_QUEUE(t);
1251 /* this does unfair scheduling; good for parallelism */
1252 PUSH_ON_RUN_QUEUE(t);
1255 /* this does round-robin scheduling; good for concurrency */
1256 APPEND_TO_RUN_QUEUE(t);
1259 /* add a ContinueThread event to actually process the thread */
1260 new_event(CurrentProc, CurrentProc, CurrentTime[CurrentProc],
1262 t, (StgClosure*)NULL, (rtsSpark*)NULL);
1264 belch("GRAN: eventq and runnableq after adding yielded thread to queue again:");
1273 belch("--<< thread %ld (%p; %s) stopped, blocking on node %p [PE %d] with BQ: ",
1274 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)));
1275 if (t->block_info.closure!=(StgClosure*)NULL) print_bq(t->block_info.closure));
1277 // ??? needed; should emit block before
1279 DumpGranEvent(GR_DESCHEDULE, t));
1280 prune_eventq(t, (StgClosure *)NULL); // prune ContinueThreads for t
1283 ASSERT(procStatus[CurrentProc]==Busy ||
1284 ((procStatus[CurrentProc]==Fetching) &&
1285 (t->block_info.closure!=(StgClosure*)NULL)));
1286 if (run_queue_hds[CurrentProc] == END_TSO_QUEUE &&
1287 !(!RtsFlags.GranFlags.DoAsyncFetch &&
1288 procStatus[CurrentProc]==Fetching))
1289 procStatus[CurrentProc] = Idle;
1293 belch("--<< thread %ld (%p; %s) stopped, blocking on node %p with BQ: ",
1294 t->id, t, whatNext_strs[t->what_next], t->block_info.closure));
1297 if (t->block_info.closure!=(StgClosure*)NULL)
1298 print_bq(t->block_info.closure));
1300 /* Send a fetch (if BlockedOnGA) and dump event to log file */
1303 /* whatever we schedule next, we must log that schedule */
1304 emitSchedule = rtsTrue;
1307 /* don't need to do anything. Either the thread is blocked on
1308 * I/O, in which case we'll have called addToBlockedQueue
1309 * previously, or it's blocked on an MVar or Blackhole, in which
1310 * case it'll be on the relevant queue already.
1313 fprintf(stderr, "--<< thread %d (%p) stopped: ", t->id, t);
1314 printThreadBlockage(t);
1315 fprintf(stderr, "\n"));
1317 /* Only for dumping event to log file
1318 ToDo: do I need this in GranSim, too?
1325 case ThreadFinished:
1326 /* Need to check whether this was a main thread, and if so, signal
1327 * the task that started it with the return value. If we have no
1328 * more main threads, we probably need to stop all the tasks until
1331 /* We also end up here if the thread kills itself with an
1332 * uncaught exception, see Exception.hc.
1334 IF_DEBUG(scheduler,belch("--++ thread %d (%p) finished", t->id, t));
1336 endThread(t, CurrentProc); // clean-up the thread
1338 /* For now all are advisory -- HWL */
1339 //if(t->priority==AdvisoryPriority) ??
1340 advisory_thread_count--;
1343 if(t->dist.priority==RevalPriority)
1347 if (RtsFlags.ParFlags.ParStats.Full &&
1348 !RtsFlags.ParFlags.ParStats.Suppressed)
1349 DumpEndEvent(CURRENT_PROC, t, rtsFalse /* not mandatory */);
1354 barf("schedule: invalid thread return code %d", (int)ret);
1358 if (RtsFlags.ProfFlags.profileInterval==0 || performHeapProfile) {
1359 GarbageCollect(GetRoots, rtsTrue);
1361 performHeapProfile = rtsFalse;
1362 ready_to_gc = rtsFalse; // we already GC'd
1368 && allFreeCapabilities()
1371 /* everybody back, start the GC.
1372 * Could do it in this thread, or signal a condition var
1373 * to do it in another thread. Either way, we need to
1374 * broadcast on gc_pending_cond afterward.
1376 #if defined(RTS_SUPPORTS_THREADS)
1377 IF_DEBUG(scheduler,sched_belch("doing GC"));
1379 GarbageCollect(GetRoots,rtsFalse);
1380 ready_to_gc = rtsFalse;
1382 broadcastCondition(&gc_pending_cond);
1385 /* add a ContinueThread event to continue execution of current thread */
1386 new_event(CurrentProc, CurrentProc, CurrentTime[CurrentProc],
1388 t, (StgClosure*)NULL, (rtsSpark*)NULL);
1390 fprintf(stderr, "GRAN: eventq and runnableq after Garbage collection:\n");
1398 IF_GRAN_DEBUG(unused,
1399 print_eventq(EventHd));
1401 event = get_next_event();
1404 /* ToDo: wait for next message to arrive rather than busy wait */
1407 } /* end of while(1) */
1409 IF_PAR_DEBUG(verbose,
1410 belch("== Leaving schedule() after having received Finish"));
1413 /* ---------------------------------------------------------------------------
1414 * Singleton fork(). Do not copy any running threads.
1415 * ------------------------------------------------------------------------- */
1417 StgInt forkProcess(StgTSO* tso) {
1419 #ifndef mingw32_TARGET_OS
1423 IF_DEBUG(scheduler,sched_belch("forking!"));
1426 if (pid) { /* parent */
1428 /* just return the pid */
1430 } else { /* child */
1431 /* wipe all other threads */
1433 tso->link = END_TSO_QUEUE;
1435 /* DO NOT TOUCH THE QUEUES directly because most of the code around
1436 us is picky about finding the threat still in its queue when
1437 handling the deleteThread() */
1439 for (t = all_threads; t != END_TSO_QUEUE; t = next) {
1441 if (t->id != tso->id) {
1448 barf("forkProcess#: primop not implemented for mingw32, sorry! (%u)\n", tso->id);
1449 /* pointlessly printing out the TSOs 'id' to avoid CC unused warning. */
1451 #endif /* mingw32 */
1454 /* ---------------------------------------------------------------------------
1455 * deleteAllThreads(): kill all the live threads.
1457 * This is used when we catch a user interrupt (^C), before performing
1458 * any necessary cleanups and running finalizers.
1460 * Locks: sched_mutex held.
1461 * ------------------------------------------------------------------------- */
1463 void deleteAllThreads ( void )
1466 IF_DEBUG(scheduler,sched_belch("deleting all threads"));
1467 for (t = all_threads; t != END_TSO_QUEUE; t = next) {
1468 next = t->global_link;
1471 run_queue_hd = run_queue_tl = END_TSO_QUEUE;
1472 blocked_queue_hd = blocked_queue_tl = END_TSO_QUEUE;
1473 sleeping_queue = END_TSO_QUEUE;
1476 /* startThread and insertThread are now in GranSim.c -- HWL */
1479 //@node Suspend and Resume, Run queue code, Main scheduling loop, Main scheduling code
1480 //@subsection Suspend and Resume
1482 /* ---------------------------------------------------------------------------
1483 * Suspending & resuming Haskell threads.
1485 * When making a "safe" call to C (aka _ccall_GC), the task gives back
1486 * its capability before calling the C function. This allows another
1487 * task to pick up the capability and carry on running Haskell
1488 * threads. It also means that if the C call blocks, it won't lock
1491 * The Haskell thread making the C call is put to sleep for the
1492 * duration of the call, on the susepended_ccalling_threads queue. We
1493 * give out a token to the task, which it can use to resume the thread
1494 * on return from the C function.
1495 * ------------------------------------------------------------------------- */
1498 suspendThread( StgRegTable *reg,
1500 #if !defined(RTS_SUPPORTS_THREADS) && !defined(DEBUG)
1508 /* assume that *reg is a pointer to the StgRegTable part
1511 cap = (Capability *)((void *)reg - sizeof(StgFunTable));
1513 ACQUIRE_LOCK(&sched_mutex);
1516 sched_belch("thread %d did a _ccall_gc (is_concurrent: %d)", cap->r.rCurrentTSO->id,concCall));
1518 threadPaused(cap->r.rCurrentTSO);
1519 cap->r.rCurrentTSO->link = suspended_ccalling_threads;
1520 suspended_ccalling_threads = cap->r.rCurrentTSO;
1522 #if defined(RTS_SUPPORTS_THREADS)
1523 cap->r.rCurrentTSO->why_blocked = BlockedOnCCall;
1526 /* Use the thread ID as the token; it should be unique */
1527 tok = cap->r.rCurrentTSO->id;
1529 /* Hand back capability */
1530 releaseCapability(cap);
1532 #if defined(RTS_SUPPORTS_THREADS)
1533 /* Preparing to leave the RTS, so ensure there's a native thread/task
1534 waiting to take over.
1536 ToDo: optimise this and only create a new task if there's a need
1537 for one (i.e., if there's only one Concurrent Haskell thread alive,
1538 there's no need to create a new task).
1540 IF_DEBUG(scheduler, sched_belch("worker thread (%d): leaving RTS", tok));
1542 startTask(taskStart);
1546 /* Other threads _might_ be available for execution; signal this */
1548 RELEASE_LOCK(&sched_mutex);
1553 resumeThread( StgInt tok,
1555 #if !defined(RTS_SUPPORTS_THREADS)
1560 StgTSO *tso, **prev;
1563 #if defined(RTS_SUPPORTS_THREADS)
1564 /* Wait for permission to re-enter the RTS with the result. */
1566 ACQUIRE_LOCK(&sched_mutex);
1567 grabReturnCapability(&sched_mutex, &cap);
1569 grabCapability(&cap);
1572 grabCapability(&cap);
1575 /* Remove the thread off of the suspended list */
1576 prev = &suspended_ccalling_threads;
1577 for (tso = suspended_ccalling_threads;
1578 tso != END_TSO_QUEUE;
1579 prev = &tso->link, tso = tso->link) {
1580 if (tso->id == (StgThreadID)tok) {
1585 if (tso == END_TSO_QUEUE) {
1586 barf("resumeThread: thread not found");
1588 tso->link = END_TSO_QUEUE;
1589 /* Reset blocking status */
1590 tso->why_blocked = NotBlocked;
1592 cap->r.rCurrentTSO = tso;
1593 RELEASE_LOCK(&sched_mutex);
1598 /* ---------------------------------------------------------------------------
1600 * ------------------------------------------------------------------------ */
1601 static void unblockThread(StgTSO *tso);
1603 /* ---------------------------------------------------------------------------
1604 * Comparing Thread ids.
1606 * This is used from STG land in the implementation of the
1607 * instances of Eq/Ord for ThreadIds.
1608 * ------------------------------------------------------------------------ */
1610 int cmp_thread(const StgTSO *tso1, const StgTSO *tso2)
1612 StgThreadID id1 = tso1->id;
1613 StgThreadID id2 = tso2->id;
1615 if (id1 < id2) return (-1);
1616 if (id1 > id2) return 1;
1620 /* ---------------------------------------------------------------------------
1621 * Fetching the ThreadID from an StgTSO.
1623 * This is used in the implementation of Show for ThreadIds.
1624 * ------------------------------------------------------------------------ */
1625 int rts_getThreadId(const StgTSO *tso)
1631 void labelThread(StgTSO *tso, char *label)
1636 /* Caveat: Once set, you can only set the thread name to "" */
1637 len = strlen(label)+1;
1638 buf = realloc(tso->label,len);
1640 fprintf(stderr,"insufficient memory for labelThread!\n");
1644 strncpy(buf,label,len);
1649 /* ---------------------------------------------------------------------------
1650 Create a new thread.
1652 The new thread starts with the given stack size. Before the
1653 scheduler can run, however, this thread needs to have a closure
1654 (and possibly some arguments) pushed on its stack. See
1655 pushClosure() in Schedule.h.
1657 createGenThread() and createIOThread() (in SchedAPI.h) are
1658 convenient packaged versions of this function.
1660 currently pri (priority) is only used in a GRAN setup -- HWL
1661 ------------------------------------------------------------------------ */
1662 //@cindex createThread
1664 /* currently pri (priority) is only used in a GRAN setup -- HWL */
1666 createThread(nat stack_size, StgInt pri)
1668 return createThread_(stack_size, rtsFalse, pri);
1672 createThread_(nat size, rtsBool have_lock, StgInt pri)
1676 createThread(nat stack_size)
1678 return createThread_(stack_size, rtsFalse);
1682 createThread_(nat size, rtsBool have_lock)
1689 /* First check whether we should create a thread at all */
1691 /* check that no more than RtsFlags.ParFlags.maxThreads threads are created */
1692 if (advisory_thread_count >= RtsFlags.ParFlags.maxThreads) {
1694 belch("{createThread}Daq ghuH: refusing to create another thread; no more than %d threads allowed (currently %d)",
1695 RtsFlags.ParFlags.maxThreads, advisory_thread_count);
1696 return END_TSO_QUEUE;
1702 ASSERT(!RtsFlags.GranFlags.Light || CurrentProc==0);
1705 // ToDo: check whether size = stack_size - TSO_STRUCT_SIZEW
1707 /* catch ridiculously small stack sizes */
1708 if (size < MIN_STACK_WORDS + TSO_STRUCT_SIZEW) {
1709 size = MIN_STACK_WORDS + TSO_STRUCT_SIZEW;
1712 stack_size = size - TSO_STRUCT_SIZEW;
1714 tso = (StgTSO *)allocate(size);
1715 TICK_ALLOC_TSO(stack_size, 0);
1717 SET_HDR(tso, &stg_TSO_info, CCS_SYSTEM);
1719 SET_GRAN_HDR(tso, ThisPE);
1721 tso->what_next = ThreadEnterGHC;
1727 /* tso->id needs to be unique. For now we use a heavyweight mutex to
1728 * protect the increment operation on next_thread_id.
1729 * In future, we could use an atomic increment instead.
1732 if (!have_lock) { ACQUIRE_LOCK(&sched_mutex); }
1734 tso->id = next_thread_id++;
1736 if (!have_lock) { RELEASE_LOCK(&sched_mutex); }
1739 tso->why_blocked = NotBlocked;
1740 tso->blocked_exceptions = NULL;
1742 tso->stack_size = stack_size;
1743 tso->max_stack_size = round_to_mblocks(RtsFlags.GcFlags.maxStkSize)
1745 tso->sp = (P_)&(tso->stack) + stack_size;
1748 tso->prof.CCCS = CCS_MAIN;
1751 /* put a stop frame on the stack */
1752 tso->sp -= sizeofW(StgStopFrame);
1753 SET_HDR((StgClosure*)tso->sp,(StgInfoTable *)&stg_stop_thread_info,CCS_SYSTEM);
1754 tso->su = (StgUpdateFrame*)tso->sp;
1758 tso->link = END_TSO_QUEUE;
1759 /* uses more flexible routine in GranSim */
1760 insertThread(tso, CurrentProc);
1762 /* In a non-GranSim setup the pushing of a TSO onto the runq is separated
1768 if (RtsFlags.GranFlags.GranSimStats.Full)
1769 DumpGranEvent(GR_START,tso);
1771 if (RtsFlags.ParFlags.ParStats.Full)
1772 DumpGranEvent(GR_STARTQ,tso);
1773 /* HACk to avoid SCHEDULE
1777 /* Link the new thread on the global thread list.
1779 tso->global_link = all_threads;
1783 tso->dist.priority = MandatoryPriority; //by default that is...
1787 tso->gran.pri = pri;
1789 tso->gran.magic = TSO_MAGIC; // debugging only
1791 tso->gran.sparkname = 0;
1792 tso->gran.startedat = CURRENT_TIME;
1793 tso->gran.exported = 0;
1794 tso->gran.basicblocks = 0;
1795 tso->gran.allocs = 0;
1796 tso->gran.exectime = 0;
1797 tso->gran.fetchtime = 0;
1798 tso->gran.fetchcount = 0;
1799 tso->gran.blocktime = 0;
1800 tso->gran.blockcount = 0;
1801 tso->gran.blockedat = 0;
1802 tso->gran.globalsparks = 0;
1803 tso->gran.localsparks = 0;
1804 if (RtsFlags.GranFlags.Light)
1805 tso->gran.clock = Now; /* local clock */
1807 tso->gran.clock = 0;
1809 IF_DEBUG(gran,printTSO(tso));
1812 tso->par.magic = TSO_MAGIC; // debugging only
1814 tso->par.sparkname = 0;
1815 tso->par.startedat = CURRENT_TIME;
1816 tso->par.exported = 0;
1817 tso->par.basicblocks = 0;
1818 tso->par.allocs = 0;
1819 tso->par.exectime = 0;
1820 tso->par.fetchtime = 0;
1821 tso->par.fetchcount = 0;
1822 tso->par.blocktime = 0;
1823 tso->par.blockcount = 0;
1824 tso->par.blockedat = 0;
1825 tso->par.globalsparks = 0;
1826 tso->par.localsparks = 0;
1830 globalGranStats.tot_threads_created++;
1831 globalGranStats.threads_created_on_PE[CurrentProc]++;
1832 globalGranStats.tot_sq_len += spark_queue_len(CurrentProc);
1833 globalGranStats.tot_sq_probes++;
1835 // collect parallel global statistics (currently done together with GC stats)
1836 if (RtsFlags.ParFlags.ParStats.Global &&
1837 RtsFlags.GcFlags.giveStats > NO_GC_STATS) {
1838 //fprintf(stderr, "Creating thread %d @ %11.2f\n", tso->id, usertime());
1839 globalParStats.tot_threads_created++;
1845 belch("==__ schedule: Created TSO %d (%p);",
1846 CurrentProc, tso, tso->id));
1848 IF_PAR_DEBUG(verbose,
1849 belch("==__ schedule: Created TSO %d (%p); %d threads active",
1850 tso->id, tso, advisory_thread_count));
1852 IF_DEBUG(scheduler,sched_belch("created thread %ld, stack size = %lx words",
1853 tso->id, tso->stack_size));
1860 all parallel thread creation calls should fall through the following routine.
1863 createSparkThread(rtsSpark spark)
1865 ASSERT(spark != (rtsSpark)NULL);
1866 if (advisory_thread_count >= RtsFlags.ParFlags.maxThreads)
1868 barf("{createSparkThread}Daq ghuH: refusing to create another thread; no more than %d threads allowed (currently %d)",
1869 RtsFlags.ParFlags.maxThreads, advisory_thread_count);
1870 return END_TSO_QUEUE;
1874 tso = createThread_(RtsFlags.GcFlags.initialStkSize, rtsTrue);
1875 if (tso==END_TSO_QUEUE)
1876 barf("createSparkThread: Cannot create TSO");
1878 tso->priority = AdvisoryPriority;
1880 pushClosure(tso,spark);
1881 PUSH_ON_RUN_QUEUE(tso);
1882 advisory_thread_count++;
1889 Turn a spark into a thread.
1890 ToDo: fix for SMP (needs to acquire SCHED_MUTEX!)
1893 //@cindex activateSpark
1895 activateSpark (rtsSpark spark)
1899 tso = createSparkThread(spark);
1900 if (RtsFlags.ParFlags.ParStats.Full) {
1901 //ASSERT(run_queue_hd == END_TSO_QUEUE); // I think ...
1902 IF_PAR_DEBUG(verbose,
1903 belch("==^^ activateSpark: turning spark of closure %p (%s) into a thread",
1904 (StgClosure *)spark, info_type((StgClosure *)spark)));
1906 // ToDo: fwd info on local/global spark to thread -- HWL
1907 // tso->gran.exported = spark->exported;
1908 // tso->gran.locked = !spark->global;
1909 // tso->gran.sparkname = spark->name;
1915 /* ---------------------------------------------------------------------------
1918 * scheduleThread puts a thread on the head of the runnable queue.
1919 * This will usually be done immediately after a thread is created.
1920 * The caller of scheduleThread must create the thread using e.g.
1921 * createThread and push an appropriate closure
1922 * on this thread's stack before the scheduler is invoked.
1923 * ------------------------------------------------------------------------ */
1925 static void scheduleThread_ (StgTSO* tso, rtsBool createTask);
1928 scheduleThread_(StgTSO *tso
1929 , rtsBool createTask
1930 #if !defined(THREADED_RTS)
1935 ACQUIRE_LOCK(&sched_mutex);
1937 /* Put the new thread on the head of the runnable queue. The caller
1938 * better push an appropriate closure on this thread's stack
1939 * beforehand. In the SMP case, the thread may start running as
1940 * soon as we release the scheduler lock below.
1942 PUSH_ON_RUN_QUEUE(tso);
1943 #if defined(THREADED_RTS)
1944 /* If main() is scheduling a thread, don't bother creating a
1948 startTask(taskStart);
1954 IF_DEBUG(scheduler,printTSO(tso));
1956 RELEASE_LOCK(&sched_mutex);
1959 void scheduleThread(StgTSO* tso)
1961 return scheduleThread_(tso, rtsFalse);
1964 void scheduleExtThread(StgTSO* tso)
1966 return scheduleThread_(tso, rtsTrue);
1969 /* ---------------------------------------------------------------------------
1972 * Initialise the scheduler. This resets all the queues - if the
1973 * queues contained any threads, they'll be garbage collected at the
1976 * ------------------------------------------------------------------------ */
1980 term_handler(int sig STG_UNUSED)
1983 ACQUIRE_LOCK(&term_mutex);
1985 RELEASE_LOCK(&term_mutex);
1996 for (i=0; i<=MAX_PROC; i++) {
1997 run_queue_hds[i] = END_TSO_QUEUE;
1998 run_queue_tls[i] = END_TSO_QUEUE;
1999 blocked_queue_hds[i] = END_TSO_QUEUE;
2000 blocked_queue_tls[i] = END_TSO_QUEUE;
2001 ccalling_threadss[i] = END_TSO_QUEUE;
2002 sleeping_queue = END_TSO_QUEUE;
2005 run_queue_hd = END_TSO_QUEUE;
2006 run_queue_tl = END_TSO_QUEUE;
2007 blocked_queue_hd = END_TSO_QUEUE;
2008 blocked_queue_tl = END_TSO_QUEUE;
2009 sleeping_queue = END_TSO_QUEUE;
2012 suspended_ccalling_threads = END_TSO_QUEUE;
2014 main_threads = NULL;
2015 all_threads = END_TSO_QUEUE;
2020 RtsFlags.ConcFlags.ctxtSwitchTicks =
2021 RtsFlags.ConcFlags.ctxtSwitchTime / TICK_MILLISECS;
2023 #if defined(RTS_SUPPORTS_THREADS)
2024 /* Initialise the mutex and condition variables used by
2026 initMutex(&sched_mutex);
2027 initMutex(&term_mutex);
2029 initCondition(&thread_ready_cond);
2033 initCondition(&gc_pending_cond);
2036 #if defined(RTS_SUPPORTS_THREADS)
2037 ACQUIRE_LOCK(&sched_mutex);
2040 /* Install the SIGHUP handler */
2043 struct sigaction action,oact;
2045 action.sa_handler = term_handler;
2046 sigemptyset(&action.sa_mask);
2047 action.sa_flags = 0;
2048 if (sigaction(SIGTERM, &action, &oact) != 0) {
2049 barf("can't install TERM handler");
2054 /* A capability holds the state a native thread needs in
2055 * order to execute STG code. At least one capability is
2056 * floating around (only SMP builds have more than one).
2060 #if defined(RTS_SUPPORTS_THREADS)
2061 /* start our haskell execution tasks */
2063 startTaskManager(RtsFlags.ParFlags.nNodes, taskStart);
2065 startTaskManager(0,taskStart);
2069 #if /* defined(SMP) ||*/ defined(PAR)
2073 #if defined(RTS_SUPPORTS_THREADS)
2074 RELEASE_LOCK(&sched_mutex);
2080 exitScheduler( void )
2082 #if defined(RTS_SUPPORTS_THREADS)
2087 /* -----------------------------------------------------------------------------
2088 Managing the per-task allocation areas.
2090 Each capability comes with an allocation area. These are
2091 fixed-length block lists into which allocation can be done.
2093 ToDo: no support for two-space collection at the moment???
2094 -------------------------------------------------------------------------- */
2096 /* -----------------------------------------------------------------------------
2097 * waitThread is the external interface for running a new computation
2098 * and waiting for the result.
2100 * In the non-SMP case, we create a new main thread, push it on the
2101 * main-thread stack, and invoke the scheduler to run it. The
2102 * scheduler will return when the top main thread on the stack has
2103 * completed or died, and fill in the necessary fields of the
2104 * main_thread structure.
2106 * In the SMP case, we create a main thread as before, but we then
2107 * create a new condition variable and sleep on it. When our new
2108 * main thread has completed, we'll be woken up and the status/result
2109 * will be in the main_thread struct.
2110 * -------------------------------------------------------------------------- */
2113 howManyThreadsAvail ( void )
2117 for (q = run_queue_hd; q != END_TSO_QUEUE; q = q->link)
2119 for (q = blocked_queue_hd; q != END_TSO_QUEUE; q = q->link)
2121 for (q = sleeping_queue; q != END_TSO_QUEUE; q = q->link)
2127 finishAllThreads ( void )
2130 while (run_queue_hd != END_TSO_QUEUE) {
2131 waitThread ( run_queue_hd, NULL);
2133 while (blocked_queue_hd != END_TSO_QUEUE) {
2134 waitThread ( blocked_queue_hd, NULL);
2136 while (sleeping_queue != END_TSO_QUEUE) {
2137 waitThread ( blocked_queue_hd, NULL);
2140 (blocked_queue_hd != END_TSO_QUEUE ||
2141 run_queue_hd != END_TSO_QUEUE ||
2142 sleeping_queue != END_TSO_QUEUE);
2146 waitThread(StgTSO *tso, /*out*/StgClosure **ret)
2148 IF_DEBUG(scheduler, sched_belch("== scheduler: waiting for thread (%d)\n", tso->id));
2149 #if defined(THREADED_RTS)
2150 return waitThread_(tso,ret, rtsFalse);
2152 return waitThread_(tso,ret);
2157 waitThread_(StgTSO *tso,
2158 /*out*/StgClosure **ret
2159 #if defined(THREADED_RTS)
2160 , rtsBool blockWaiting
2165 SchedulerStatus stat;
2167 ACQUIRE_LOCK(&sched_mutex);
2168 IF_DEBUG(scheduler, sched_belch("== scheduler: waiting for thread (%d)\n", tso->id));
2170 m = stgMallocBytes(sizeof(StgMainThread), "waitThread");
2175 #if defined(RTS_SUPPORTS_THREADS)
2176 initCondition(&m->wakeup);
2179 m->link = main_threads;
2182 IF_DEBUG(scheduler, sched_belch("== scheduler: new main thread (%d)\n", m->tso->id));
2184 #if defined(RTS_SUPPORTS_THREADS)
2186 # if defined(THREADED_RTS)
2187 if (!blockWaiting) {
2188 /* In the threaded case, the OS thread that called main()
2189 * gets to enter the RTS directly without going via another
2192 RELEASE_LOCK(&sched_mutex);
2194 ASSERT(m->stat != NoStatus);
2198 IF_DEBUG(scheduler, sched_belch("sfoo"));
2200 waitCondition(&m->wakeup, &sched_mutex);
2201 } while (m->stat == NoStatus);
2204 /* GranSim specific init */
2205 CurrentTSO = m->tso; // the TSO to run
2206 procStatus[MainProc] = Busy; // status of main PE
2207 CurrentProc = MainProc; // PE to run it on
2211 RELEASE_LOCK(&sched_mutex);
2213 ASSERT(m->stat != NoStatus);
2218 #if defined(RTS_SUPPORTS_THREADS)
2219 closeCondition(&m->wakeup);
2222 IF_DEBUG(scheduler, fprintf(stderr, "== scheduler: main thread (%d) finished\n",
2226 #if defined(THREADED_RTS)
2229 RELEASE_LOCK(&sched_mutex);
2234 //@node Run queue code, Garbage Collextion Routines, Suspend and Resume, Main scheduling code
2235 //@subsection Run queue code
2239 NB: In GranSim we have many run queues; run_queue_hd is actually a macro
2240 unfolding to run_queue_hds[CurrentProc], thus CurrentProc is an
2241 implicit global variable that has to be correct when calling these
2245 /* Put the new thread on the head of the runnable queue.
2246 * The caller of createThread better push an appropriate closure
2247 * on this thread's stack before the scheduler is invoked.
2249 static /* inline */ void
2250 add_to_run_queue(tso)
2253 ASSERT(tso!=run_queue_hd && tso!=run_queue_tl);
2254 tso->link = run_queue_hd;
2256 if (run_queue_tl == END_TSO_QUEUE) {
2261 /* Put the new thread at the end of the runnable queue. */
2262 static /* inline */ void
2263 push_on_run_queue(tso)
2266 ASSERT(get_itbl((StgClosure *)tso)->type == TSO);
2267 ASSERT(run_queue_hd!=NULL && run_queue_tl!=NULL);
2268 ASSERT(tso!=run_queue_hd && tso!=run_queue_tl);
2269 if (run_queue_hd == END_TSO_QUEUE) {
2272 run_queue_tl->link = tso;
2278 Should be inlined because it's used very often in schedule. The tso
2279 argument is actually only needed in GranSim, where we want to have the
2280 possibility to schedule *any* TSO on the run queue, irrespective of the
2281 actual ordering. Therefore, if tso is not the nil TSO then we traverse
2282 the run queue and dequeue the tso, adjusting the links in the queue.
2284 //@cindex take_off_run_queue
2285 static /* inline */ StgTSO*
2286 take_off_run_queue(StgTSO *tso) {
2290 qetlaHbogh Qu' ngaSbogh ghomDaQ {tso} yIteq!
2292 if tso is specified, unlink that tso from the run_queue (doesn't have
2293 to be at the beginning of the queue); GranSim only
2295 if (tso!=END_TSO_QUEUE) {
2296 /* find tso in queue */
2297 for (t=run_queue_hd, prev=END_TSO_QUEUE;
2298 t!=END_TSO_QUEUE && t!=tso;
2302 /* now actually dequeue the tso */
2303 if (prev!=END_TSO_QUEUE) {
2304 ASSERT(run_queue_hd!=t);
2305 prev->link = t->link;
2307 /* t is at beginning of thread queue */
2308 ASSERT(run_queue_hd==t);
2309 run_queue_hd = t->link;
2311 /* t is at end of thread queue */
2312 if (t->link==END_TSO_QUEUE) {
2313 ASSERT(t==run_queue_tl);
2314 run_queue_tl = prev;
2316 ASSERT(run_queue_tl!=t);
2318 t->link = END_TSO_QUEUE;
2320 /* take tso from the beginning of the queue; std concurrent code */
2322 if (t != END_TSO_QUEUE) {
2323 run_queue_hd = t->link;
2324 t->link = END_TSO_QUEUE;
2325 if (run_queue_hd == END_TSO_QUEUE) {
2326 run_queue_tl = END_TSO_QUEUE;
2335 //@node Garbage Collextion Routines, Blocking Queue Routines, Run queue code, Main scheduling code
2336 //@subsection Garbage Collextion Routines
2338 /* ---------------------------------------------------------------------------
2339 Where are the roots that we know about?
2341 - all the threads on the runnable queue
2342 - all the threads on the blocked queue
2343 - all the threads on the sleeping queue
2344 - all the thread currently executing a _ccall_GC
2345 - all the "main threads"
2347 ------------------------------------------------------------------------ */
2349 /* This has to be protected either by the scheduler monitor, or by the
2350 garbage collection monitor (probably the latter).
2355 GetRoots(evac_fn evac)
2360 for (i=0; i<=RtsFlags.GranFlags.proc; i++) {
2361 if ((run_queue_hds[i] != END_TSO_QUEUE) && ((run_queue_hds[i] != NULL)))
2362 evac((StgClosure **)&run_queue_hds[i]);
2363 if ((run_queue_tls[i] != END_TSO_QUEUE) && ((run_queue_tls[i] != NULL)))
2364 evac((StgClosure **)&run_queue_tls[i]);
2366 if ((blocked_queue_hds[i] != END_TSO_QUEUE) && ((blocked_queue_hds[i] != NULL)))
2367 evac((StgClosure **)&blocked_queue_hds[i]);
2368 if ((blocked_queue_tls[i] != END_TSO_QUEUE) && ((blocked_queue_tls[i] != NULL)))
2369 evac((StgClosure **)&blocked_queue_tls[i]);
2370 if ((ccalling_threadss[i] != END_TSO_QUEUE) && ((ccalling_threadss[i] != NULL)))
2371 evac((StgClosure **)&ccalling_threads[i]);
2378 if (run_queue_hd != END_TSO_QUEUE) {
2379 ASSERT(run_queue_tl != END_TSO_QUEUE);
2380 evac((StgClosure **)&run_queue_hd);
2381 evac((StgClosure **)&run_queue_tl);
2384 if (blocked_queue_hd != END_TSO_QUEUE) {
2385 ASSERT(blocked_queue_tl != END_TSO_QUEUE);
2386 evac((StgClosure **)&blocked_queue_hd);
2387 evac((StgClosure **)&blocked_queue_tl);
2390 if (sleeping_queue != END_TSO_QUEUE) {
2391 evac((StgClosure **)&sleeping_queue);
2395 if (suspended_ccalling_threads != END_TSO_QUEUE) {
2396 evac((StgClosure **)&suspended_ccalling_threads);
2399 #if defined(PAR) || defined(GRAN)
2400 markSparkQueue(evac);
2404 /* -----------------------------------------------------------------------------
2407 This is the interface to the garbage collector from Haskell land.
2408 We provide this so that external C code can allocate and garbage
2409 collect when called from Haskell via _ccall_GC.
2411 It might be useful to provide an interface whereby the programmer
2412 can specify more roots (ToDo).
2414 This needs to be protected by the GC condition variable above. KH.
2415 -------------------------------------------------------------------------- */
2417 void (*extra_roots)(evac_fn);
2422 /* Obligated to hold this lock upon entry */
2423 ACQUIRE_LOCK(&sched_mutex);
2424 GarbageCollect(GetRoots,rtsFalse);
2425 RELEASE_LOCK(&sched_mutex);
2429 performMajorGC(void)
2431 ACQUIRE_LOCK(&sched_mutex);
2432 GarbageCollect(GetRoots,rtsTrue);
2433 RELEASE_LOCK(&sched_mutex);
2437 AllRoots(evac_fn evac)
2439 GetRoots(evac); // the scheduler's roots
2440 extra_roots(evac); // the user's roots
2444 performGCWithRoots(void (*get_roots)(evac_fn))
2446 ACQUIRE_LOCK(&sched_mutex);
2447 extra_roots = get_roots;
2448 GarbageCollect(AllRoots,rtsFalse);
2449 RELEASE_LOCK(&sched_mutex);
2452 /* -----------------------------------------------------------------------------
2455 If the thread has reached its maximum stack size, then raise the
2456 StackOverflow exception in the offending thread. Otherwise
2457 relocate the TSO into a larger chunk of memory and adjust its stack
2459 -------------------------------------------------------------------------- */
2462 threadStackOverflow(StgTSO *tso)
2464 nat new_stack_size, new_tso_size, diff, stack_words;
2468 IF_DEBUG(sanity,checkTSO(tso));
2469 if (tso->stack_size >= tso->max_stack_size) {
2472 belch("@@ threadStackOverflow of TSO %d (%p): stack too large (now %ld; max is %ld",
2473 tso->id, tso, tso->stack_size, tso->max_stack_size);
2474 /* If we're debugging, just print out the top of the stack */
2475 printStackChunk(tso->sp, stg_min(tso->stack+tso->stack_size,
2478 /* Send this thread the StackOverflow exception */
2479 raiseAsync(tso, (StgClosure *)stackOverflow_closure);
2483 /* Try to double the current stack size. If that takes us over the
2484 * maximum stack size for this thread, then use the maximum instead.
2485 * Finally round up so the TSO ends up as a whole number of blocks.
2487 new_stack_size = stg_min(tso->stack_size * 2, tso->max_stack_size);
2488 new_tso_size = (nat)BLOCK_ROUND_UP(new_stack_size * sizeof(W_) +
2489 TSO_STRUCT_SIZE)/sizeof(W_);
2490 new_tso_size = round_to_mblocks(new_tso_size); /* Be MBLOCK-friendly */
2491 new_stack_size = new_tso_size - TSO_STRUCT_SIZEW;
2493 IF_DEBUG(scheduler, fprintf(stderr,"== scheduler: increasing stack size from %d words to %d.\n", tso->stack_size, new_stack_size));
2495 dest = (StgTSO *)allocate(new_tso_size);
2496 TICK_ALLOC_TSO(new_stack_size,0);
2498 /* copy the TSO block and the old stack into the new area */
2499 memcpy(dest,tso,TSO_STRUCT_SIZE);
2500 stack_words = tso->stack + tso->stack_size - tso->sp;
2501 new_sp = (P_)dest + new_tso_size - stack_words;
2502 memcpy(new_sp, tso->sp, stack_words * sizeof(W_));
2504 /* relocate the stack pointers... */
2505 diff = (P_)new_sp - (P_)tso->sp; /* In *words* */
2506 dest->su = (StgUpdateFrame *) ((P_)dest->su + diff);
2508 dest->stack_size = new_stack_size;
2510 /* and relocate the update frame list */
2511 relocate_stack(dest, diff);
2513 /* Mark the old TSO as relocated. We have to check for relocated
2514 * TSOs in the garbage collector and any primops that deal with TSOs.
2516 * It's important to set the sp and su values to just beyond the end
2517 * of the stack, so we don't attempt to scavenge any part of the
2520 tso->what_next = ThreadRelocated;
2522 tso->sp = (P_)&(tso->stack[tso->stack_size]);
2523 tso->su = (StgUpdateFrame *)tso->sp;
2524 tso->why_blocked = NotBlocked;
2525 dest->mut_link = NULL;
2527 IF_PAR_DEBUG(verbose,
2528 belch("@@ threadStackOverflow of TSO %d (now at %p): stack size increased to %ld",
2529 tso->id, tso, tso->stack_size);
2530 /* If we're debugging, just print out the top of the stack */
2531 printStackChunk(tso->sp, stg_min(tso->stack+tso->stack_size,
2534 IF_DEBUG(sanity,checkTSO(tso));
2536 IF_DEBUG(scheduler,printTSO(dest));
2542 //@node Blocking Queue Routines, Exception Handling Routines, Garbage Collextion Routines, Main scheduling code
2543 //@subsection Blocking Queue Routines
2545 /* ---------------------------------------------------------------------------
2546 Wake up a queue that was blocked on some resource.
2547 ------------------------------------------------------------------------ */
2551 unblockCount ( StgBlockingQueueElement *bqe, StgClosure *node )
2556 unblockCount ( StgBlockingQueueElement *bqe, StgClosure *node )
2558 /* write RESUME events to log file and
2559 update blocked and fetch time (depending on type of the orig closure) */
2560 if (RtsFlags.ParFlags.ParStats.Full) {
2561 DumpRawGranEvent(CURRENT_PROC, CURRENT_PROC,
2562 GR_RESUMEQ, ((StgTSO *)bqe), ((StgTSO *)bqe)->block_info.closure,
2563 0, 0 /* spark_queue_len(ADVISORY_POOL) */);
2564 if (EMPTY_RUN_QUEUE())
2565 emitSchedule = rtsTrue;
2567 switch (get_itbl(node)->type) {
2569 ((StgTSO *)bqe)->par.fetchtime += CURRENT_TIME-((StgTSO *)bqe)->par.blockedat;
2574 ((StgTSO *)bqe)->par.blocktime += CURRENT_TIME-((StgTSO *)bqe)->par.blockedat;
2581 barf("{unblockOneLocked}Daq Qagh: unexpected closure in blocking queue");
2588 static StgBlockingQueueElement *
2589 unblockOneLocked(StgBlockingQueueElement *bqe, StgClosure *node)
2592 PEs node_loc, tso_loc;
2594 node_loc = where_is(node); // should be lifted out of loop
2595 tso = (StgTSO *)bqe; // wastes an assignment to get the type right
2596 tso_loc = where_is((StgClosure *)tso);
2597 if (IS_LOCAL_TO(PROCS(node),tso_loc)) { // TSO is local
2598 /* !fake_fetch => TSO is on CurrentProc is same as IS_LOCAL_TO */
2599 ASSERT(CurrentProc!=node_loc || tso_loc==CurrentProc);
2600 CurrentTime[CurrentProc] += RtsFlags.GranFlags.Costs.lunblocktime;
2601 // insertThread(tso, node_loc);
2602 new_event(tso_loc, tso_loc, CurrentTime[CurrentProc],
2604 tso, node, (rtsSpark*)NULL);
2605 tso->link = END_TSO_QUEUE; // overwrite link just to be sure
2608 } else { // TSO is remote (actually should be FMBQ)
2609 CurrentTime[CurrentProc] += RtsFlags.GranFlags.Costs.mpacktime +
2610 RtsFlags.GranFlags.Costs.gunblocktime +
2611 RtsFlags.GranFlags.Costs.latency;
2612 new_event(tso_loc, CurrentProc, CurrentTime[CurrentProc],
2614 tso, node, (rtsSpark*)NULL);
2615 tso->link = END_TSO_QUEUE; // overwrite link just to be sure
2618 /* the thread-queue-overhead is accounted for in either Resume or UnblockThread */
2620 fprintf(stderr," %s TSO %d (%p) [PE %d] (block_info.closure=%p) (next=%p) ,",
2621 (node_loc==tso_loc ? "Local" : "Global"),
2622 tso->id, tso, CurrentProc, tso->block_info.closure, tso->link));
2623 tso->block_info.closure = NULL;
2624 IF_DEBUG(scheduler,belch("-- Waking up thread %ld (%p)",
2628 static StgBlockingQueueElement *
2629 unblockOneLocked(StgBlockingQueueElement *bqe, StgClosure *node)
2631 StgBlockingQueueElement *next;
2633 switch (get_itbl(bqe)->type) {
2635 ASSERT(((StgTSO *)bqe)->why_blocked != NotBlocked);
2636 /* if it's a TSO just push it onto the run_queue */
2638 // ((StgTSO *)bqe)->link = END_TSO_QUEUE; // debugging?
2639 PUSH_ON_RUN_QUEUE((StgTSO *)bqe);
2641 unblockCount(bqe, node);
2642 /* reset blocking status after dumping event */
2643 ((StgTSO *)bqe)->why_blocked = NotBlocked;
2647 /* if it's a BLOCKED_FETCH put it on the PendingFetches list */
2649 bqe->link = (StgBlockingQueueElement *)PendingFetches;
2650 PendingFetches = (StgBlockedFetch *)bqe;
2654 /* can ignore this case in a non-debugging setup;
2655 see comments on RBHSave closures above */
2657 /* check that the closure is an RBHSave closure */
2658 ASSERT(get_itbl((StgClosure *)bqe) == &stg_RBH_Save_0_info ||
2659 get_itbl((StgClosure *)bqe) == &stg_RBH_Save_1_info ||
2660 get_itbl((StgClosure *)bqe) == &stg_RBH_Save_2_info);
2664 barf("{unblockOneLocked}Daq Qagh: Unexpected IP (%#lx; %s) in blocking queue at %#lx\n",
2665 get_itbl((StgClosure *)bqe), info_type((StgClosure *)bqe),
2669 IF_PAR_DEBUG(bq, fprintf(stderr, ", %p (%s)", bqe, info_type((StgClosure*)bqe)));
2673 #else /* !GRAN && !PAR */
2675 unblockOneLocked(StgTSO *tso)
2679 ASSERT(get_itbl(tso)->type == TSO);
2680 ASSERT(tso->why_blocked != NotBlocked);
2681 tso->why_blocked = NotBlocked;
2683 PUSH_ON_RUN_QUEUE(tso);
2685 IF_DEBUG(scheduler,sched_belch("waking up thread %ld", tso->id));
2690 #if defined(GRAN) || defined(PAR)
2691 inline StgBlockingQueueElement *
2692 unblockOne(StgBlockingQueueElement *bqe, StgClosure *node)
2694 ACQUIRE_LOCK(&sched_mutex);
2695 bqe = unblockOneLocked(bqe, node);
2696 RELEASE_LOCK(&sched_mutex);
2701 unblockOne(StgTSO *tso)
2703 ACQUIRE_LOCK(&sched_mutex);
2704 tso = unblockOneLocked(tso);
2705 RELEASE_LOCK(&sched_mutex);
2712 awakenBlockedQueue(StgBlockingQueueElement *q, StgClosure *node)
2714 StgBlockingQueueElement *bqe;
2719 belch("##-_ AwBQ for node %p on PE %d @ %ld by TSO %d (%p): ", \
2720 node, CurrentProc, CurrentTime[CurrentProc],
2721 CurrentTSO->id, CurrentTSO));
2723 node_loc = where_is(node);
2725 ASSERT(q == END_BQ_QUEUE ||
2726 get_itbl(q)->type == TSO || // q is either a TSO or an RBHSave
2727 get_itbl(q)->type == CONSTR); // closure (type constructor)
2728 ASSERT(is_unique(node));
2730 /* FAKE FETCH: magically copy the node to the tso's proc;
2731 no Fetch necessary because in reality the node should not have been
2732 moved to the other PE in the first place
2734 if (CurrentProc!=node_loc) {
2736 belch("## node %p is on PE %d but CurrentProc is %d (TSO %d); assuming fake fetch and adjusting bitmask (old: %#x)",
2737 node, node_loc, CurrentProc, CurrentTSO->id,
2738 // CurrentTSO, where_is(CurrentTSO),
2739 node->header.gran.procs));
2740 node->header.gran.procs = (node->header.gran.procs) | PE_NUMBER(CurrentProc);
2742 belch("## new bitmask of node %p is %#x",
2743 node, node->header.gran.procs));
2744 if (RtsFlags.GranFlags.GranSimStats.Global) {
2745 globalGranStats.tot_fake_fetches++;
2750 // ToDo: check: ASSERT(CurrentProc==node_loc);
2751 while (get_itbl(bqe)->type==TSO) { // q != END_TSO_QUEUE) {
2754 bqe points to the current element in the queue
2755 next points to the next element in the queue
2757 //tso = (StgTSO *)bqe; // wastes an assignment to get the type right
2758 //tso_loc = where_is(tso);
2760 bqe = unblockOneLocked(bqe, node);
2763 /* if this is the BQ of an RBH, we have to put back the info ripped out of
2764 the closure to make room for the anchor of the BQ */
2765 if (bqe!=END_BQ_QUEUE) {
2766 ASSERT(get_itbl(node)->type == RBH && get_itbl(bqe)->type == CONSTR);
2768 ASSERT((info_ptr==&RBH_Save_0_info) ||
2769 (info_ptr==&RBH_Save_1_info) ||
2770 (info_ptr==&RBH_Save_2_info));
2772 /* cf. convertToRBH in RBH.c for writing the RBHSave closure */
2773 ((StgRBH *)node)->blocking_queue = (StgBlockingQueueElement *)((StgRBHSave *)bqe)->payload[0];
2774 ((StgRBH *)node)->mut_link = (StgMutClosure *)((StgRBHSave *)bqe)->payload[1];
2777 belch("## Filled in RBH_Save for %p (%s) at end of AwBQ",
2778 node, info_type(node)));
2781 /* statistics gathering */
2782 if (RtsFlags.GranFlags.GranSimStats.Global) {
2783 // globalGranStats.tot_bq_processing_time += bq_processing_time;
2784 globalGranStats.tot_bq_len += len; // total length of all bqs awakened
2785 // globalGranStats.tot_bq_len_local += len_local; // same for local TSOs only
2786 globalGranStats.tot_awbq++; // total no. of bqs awakened
2789 fprintf(stderr,"## BQ Stats of %p: [%d entries] %s\n",
2790 node, len, (bqe!=END_BQ_QUEUE) ? "RBH" : ""));
2794 awakenBlockedQueue(StgBlockingQueueElement *q, StgClosure *node)
2796 StgBlockingQueueElement *bqe;
2798 ACQUIRE_LOCK(&sched_mutex);
2800 IF_PAR_DEBUG(verbose,
2801 belch("##-_ AwBQ for node %p on [%x]: ",
2805 if(get_itbl(q)->type == CONSTR || q==END_BQ_QUEUE) {
2806 IF_PAR_DEBUG(verbose, belch("## ... nothing to unblock so lets just return. RFP (BUG?)"));
2811 ASSERT(q == END_BQ_QUEUE ||
2812 get_itbl(q)->type == TSO ||
2813 get_itbl(q)->type == BLOCKED_FETCH ||
2814 get_itbl(q)->type == CONSTR);
2817 while (get_itbl(bqe)->type==TSO ||
2818 get_itbl(bqe)->type==BLOCKED_FETCH) {
2819 bqe = unblockOneLocked(bqe, node);
2821 RELEASE_LOCK(&sched_mutex);
2824 #else /* !GRAN && !PAR */
2826 awakenBlockedQueue(StgTSO *tso)
2828 ACQUIRE_LOCK(&sched_mutex);
2829 while (tso != END_TSO_QUEUE) {
2830 tso = unblockOneLocked(tso);
2832 RELEASE_LOCK(&sched_mutex);
2836 //@node Exception Handling Routines, Debugging Routines, Blocking Queue Routines, Main scheduling code
2837 //@subsection Exception Handling Routines
2839 /* ---------------------------------------------------------------------------
2841 - usually called inside a signal handler so it mustn't do anything fancy.
2842 ------------------------------------------------------------------------ */
2845 interruptStgRts(void)
2851 /* -----------------------------------------------------------------------------
2854 This is for use when we raise an exception in another thread, which
2856 This has nothing to do with the UnblockThread event in GranSim. -- HWL
2857 -------------------------------------------------------------------------- */
2859 #if defined(GRAN) || defined(PAR)
2861 NB: only the type of the blocking queue is different in GranSim and GUM
2862 the operations on the queue-elements are the same
2863 long live polymorphism!
2865 Locks: sched_mutex is held upon entry and exit.
2869 unblockThread(StgTSO *tso)
2871 StgBlockingQueueElement *t, **last;
2873 switch (tso->why_blocked) {
2876 return; /* not blocked */
2879 ASSERT(get_itbl(tso->block_info.closure)->type == MVAR);
2881 StgBlockingQueueElement *last_tso = END_BQ_QUEUE;
2882 StgMVar *mvar = (StgMVar *)(tso->block_info.closure);
2884 last = (StgBlockingQueueElement **)&mvar->head;
2885 for (t = (StgBlockingQueueElement *)mvar->head;
2887 last = &t->link, last_tso = t, t = t->link) {
2888 if (t == (StgBlockingQueueElement *)tso) {
2889 *last = (StgBlockingQueueElement *)tso->link;
2890 if (mvar->tail == tso) {
2891 mvar->tail = (StgTSO *)last_tso;
2896 barf("unblockThread (MVAR): TSO not found");
2899 case BlockedOnBlackHole:
2900 ASSERT(get_itbl(tso->block_info.closure)->type == BLACKHOLE_BQ);
2902 StgBlockingQueue *bq = (StgBlockingQueue *)(tso->block_info.closure);
2904 last = &bq->blocking_queue;
2905 for (t = bq->blocking_queue;
2907 last = &t->link, t = t->link) {
2908 if (t == (StgBlockingQueueElement *)tso) {
2909 *last = (StgBlockingQueueElement *)tso->link;
2913 barf("unblockThread (BLACKHOLE): TSO not found");
2916 case BlockedOnException:
2918 StgTSO *target = tso->block_info.tso;
2920 ASSERT(get_itbl(target)->type == TSO);
2922 if (target->what_next == ThreadRelocated) {
2923 target = target->link;
2924 ASSERT(get_itbl(target)->type == TSO);
2927 ASSERT(target->blocked_exceptions != NULL);
2929 last = (StgBlockingQueueElement **)&target->blocked_exceptions;
2930 for (t = (StgBlockingQueueElement *)target->blocked_exceptions;
2932 last = &t->link, t = t->link) {
2933 ASSERT(get_itbl(t)->type == TSO);
2934 if (t == (StgBlockingQueueElement *)tso) {
2935 *last = (StgBlockingQueueElement *)tso->link;
2939 barf("unblockThread (Exception): TSO not found");
2943 case BlockedOnWrite:
2945 /* take TSO off blocked_queue */
2946 StgBlockingQueueElement *prev = NULL;
2947 for (t = (StgBlockingQueueElement *)blocked_queue_hd; t != END_BQ_QUEUE;
2948 prev = t, t = t->link) {
2949 if (t == (StgBlockingQueueElement *)tso) {
2951 blocked_queue_hd = (StgTSO *)t->link;
2952 if ((StgBlockingQueueElement *)blocked_queue_tl == t) {
2953 blocked_queue_tl = END_TSO_QUEUE;
2956 prev->link = t->link;
2957 if ((StgBlockingQueueElement *)blocked_queue_tl == t) {
2958 blocked_queue_tl = (StgTSO *)prev;
2964 barf("unblockThread (I/O): TSO not found");
2967 case BlockedOnDelay:
2969 /* take TSO off sleeping_queue */
2970 StgBlockingQueueElement *prev = NULL;
2971 for (t = (StgBlockingQueueElement *)sleeping_queue; t != END_BQ_QUEUE;
2972 prev = t, t = t->link) {
2973 if (t == (StgBlockingQueueElement *)tso) {
2975 sleeping_queue = (StgTSO *)t->link;
2977 prev->link = t->link;
2982 barf("unblockThread (I/O): TSO not found");
2986 barf("unblockThread");
2990 tso->link = END_TSO_QUEUE;
2991 tso->why_blocked = NotBlocked;
2992 tso->block_info.closure = NULL;
2993 PUSH_ON_RUN_QUEUE(tso);
2997 unblockThread(StgTSO *tso)
3001 /* To avoid locking unnecessarily. */
3002 if (tso->why_blocked == NotBlocked) {
3006 switch (tso->why_blocked) {
3009 ASSERT(get_itbl(tso->block_info.closure)->type == MVAR);
3011 StgTSO *last_tso = END_TSO_QUEUE;
3012 StgMVar *mvar = (StgMVar *)(tso->block_info.closure);
3015 for (t = mvar->head; t != END_TSO_QUEUE;
3016 last = &t->link, last_tso = t, t = t->link) {
3019 if (mvar->tail == tso) {
3020 mvar->tail = last_tso;
3025 barf("unblockThread (MVAR): TSO not found");
3028 case BlockedOnBlackHole:
3029 ASSERT(get_itbl(tso->block_info.closure)->type == BLACKHOLE_BQ);
3031 StgBlockingQueue *bq = (StgBlockingQueue *)(tso->block_info.closure);
3033 last = &bq->blocking_queue;
3034 for (t = bq->blocking_queue; t != END_TSO_QUEUE;
3035 last = &t->link, t = t->link) {
3041 barf("unblockThread (BLACKHOLE): TSO not found");
3044 case BlockedOnException:
3046 StgTSO *target = tso->block_info.tso;
3048 ASSERT(get_itbl(target)->type == TSO);
3050 while (target->what_next == ThreadRelocated) {
3051 target = target->link;
3052 ASSERT(get_itbl(target)->type == TSO);
3055 ASSERT(target->blocked_exceptions != NULL);
3057 last = &target->blocked_exceptions;
3058 for (t = target->blocked_exceptions; t != END_TSO_QUEUE;
3059 last = &t->link, t = t->link) {
3060 ASSERT(get_itbl(t)->type == TSO);
3066 barf("unblockThread (Exception): TSO not found");
3070 case BlockedOnWrite:
3072 StgTSO *prev = NULL;
3073 for (t = blocked_queue_hd; t != END_TSO_QUEUE;
3074 prev = t, t = t->link) {
3077 blocked_queue_hd = t->link;
3078 if (blocked_queue_tl == t) {
3079 blocked_queue_tl = END_TSO_QUEUE;
3082 prev->link = t->link;
3083 if (blocked_queue_tl == t) {
3084 blocked_queue_tl = prev;
3090 barf("unblockThread (I/O): TSO not found");
3093 case BlockedOnDelay:
3095 StgTSO *prev = NULL;
3096 for (t = sleeping_queue; t != END_TSO_QUEUE;
3097 prev = t, t = t->link) {
3100 sleeping_queue = t->link;
3102 prev->link = t->link;
3107 barf("unblockThread (I/O): TSO not found");
3111 barf("unblockThread");
3115 tso->link = END_TSO_QUEUE;
3116 tso->why_blocked = NotBlocked;
3117 tso->block_info.closure = NULL;
3118 PUSH_ON_RUN_QUEUE(tso);
3122 /* -----------------------------------------------------------------------------
3125 * The following function implements the magic for raising an
3126 * asynchronous exception in an existing thread.
3128 * We first remove the thread from any queue on which it might be
3129 * blocked. The possible blockages are MVARs and BLACKHOLE_BQs.
3131 * We strip the stack down to the innermost CATCH_FRAME, building
3132 * thunks in the heap for all the active computations, so they can
3133 * be restarted if necessary. When we reach a CATCH_FRAME, we build
3134 * an application of the handler to the exception, and push it on
3135 * the top of the stack.
3137 * How exactly do we save all the active computations? We create an
3138 * AP_UPD for every UpdateFrame on the stack. Entering one of these
3139 * AP_UPDs pushes everything from the corresponding update frame
3140 * upwards onto the stack. (Actually, it pushes everything up to the
3141 * next update frame plus a pointer to the next AP_UPD object.
3142 * Entering the next AP_UPD object pushes more onto the stack until we
3143 * reach the last AP_UPD object - at which point the stack should look
3144 * exactly as it did when we killed the TSO and we can continue
3145 * execution by entering the closure on top of the stack.
3147 * We can also kill a thread entirely - this happens if either (a) the
3148 * exception passed to raiseAsync is NULL, or (b) there's no
3149 * CATCH_FRAME on the stack. In either case, we strip the entire
3150 * stack and replace the thread with a zombie.
3152 * Locks: sched_mutex held upon entry nor exit.
3154 * -------------------------------------------------------------------------- */
3157 deleteThread(StgTSO *tso)
3159 raiseAsync(tso,NULL);
3163 raiseAsyncWithLock(StgTSO *tso, StgClosure *exception)
3165 /* When raising async exs from contexts where sched_mutex isn't held;
3166 use raiseAsyncWithLock(). */
3167 ACQUIRE_LOCK(&sched_mutex);
3168 raiseAsync(tso,exception);
3169 RELEASE_LOCK(&sched_mutex);
3173 raiseAsync(StgTSO *tso, StgClosure *exception)
3175 StgUpdateFrame* su = tso->su;
3176 StgPtr sp = tso->sp;
3178 /* Thread already dead? */
3179 if (tso->what_next == ThreadComplete || tso->what_next == ThreadKilled) {
3183 IF_DEBUG(scheduler, sched_belch("raising exception in thread %ld.", tso->id));
3185 /* Remove it from any blocking queues */
3188 IF_DEBUG(scheduler, sched_belch("raising exception in thread %ld.", tso->id));
3189 /* The stack freezing code assumes there's a closure pointer on
3190 * the top of the stack. This isn't always the case with compiled
3191 * code, so we have to push a dummy closure on the top which just
3192 * returns to the next return address on the stack.
3194 if ( LOOKS_LIKE_GHC_INFO((void*)*sp) ) {
3195 *(--sp) = (W_)&stg_dummy_ret_closure;
3199 nat words = ((P_)su - (P_)sp) - 1;
3203 /* If we find a CATCH_FRAME, and we've got an exception to raise,
3204 * then build the THUNK raise(exception), and leave it on
3205 * top of the CATCH_FRAME ready to enter.
3207 if (get_itbl(su)->type == CATCH_FRAME && exception != NULL) {
3209 StgCatchFrame *cf = (StgCatchFrame *)su;
3213 /* we've got an exception to raise, so let's pass it to the
3214 * handler in this frame.
3216 raise = (StgClosure *)allocate(sizeofW(StgClosure)+1);
3217 TICK_ALLOC_SE_THK(1,0);
3218 SET_HDR(raise,&stg_raise_info,cf->header.prof.ccs);
3219 raise->payload[0] = exception;
3221 /* throw away the stack from Sp up to the CATCH_FRAME.
3225 /* Ensure that async excpetions are blocked now, so we don't get
3226 * a surprise exception before we get around to executing the
3229 if (tso->blocked_exceptions == NULL) {
3230 tso->blocked_exceptions = END_TSO_QUEUE;
3233 /* Put the newly-built THUNK on top of the stack, ready to execute
3234 * when the thread restarts.
3239 tso->what_next = ThreadEnterGHC;
3240 IF_DEBUG(sanity, checkTSO(tso));
3244 /* First build an AP_UPD consisting of the stack chunk above the
3245 * current update frame, with the top word on the stack as the
3248 ap = (StgAP_UPD *)allocate(AP_sizeW(words));
3253 ap->fun = (StgClosure *)sp[0];
3255 for(i=0; i < (nat)words; ++i) {
3256 ap->payload[i] = (StgClosure *)*sp++;
3259 switch (get_itbl(su)->type) {
3263 SET_HDR(ap,&stg_AP_UPD_info,su->header.prof.ccs /* ToDo */);
3264 TICK_ALLOC_UP_THK(words+1,0);
3267 fprintf(stderr, "scheduler: Updating ");
3268 printPtr((P_)su->updatee);
3269 fprintf(stderr, " with ");
3270 printObj((StgClosure *)ap);
3273 /* Replace the updatee with an indirection - happily
3274 * this will also wake up any threads currently
3275 * waiting on the result.
3277 * Warning: if we're in a loop, more than one update frame on
3278 * the stack may point to the same object. Be careful not to
3279 * overwrite an IND_OLDGEN in this case, because we'll screw
3280 * up the mutable lists. To be on the safe side, don't
3281 * overwrite any kind of indirection at all. See also
3282 * threadSqueezeStack in GC.c, where we have to make a similar
3285 if (!closure_IND(su->updatee)) {
3286 UPD_IND_NOLOCK(su->updatee,ap); /* revert the black hole */
3289 sp += sizeofW(StgUpdateFrame) -1;
3290 sp[0] = (W_)ap; /* push onto stack */
3296 StgCatchFrame *cf = (StgCatchFrame *)su;
3299 /* We want a PAP, not an AP_UPD. Fortunately, the
3300 * layout's the same.
3302 SET_HDR(ap,&stg_PAP_info,su->header.prof.ccs /* ToDo */);
3303 TICK_ALLOC_UPD_PAP(words+1,0);
3305 /* now build o = FUN(catch,ap,handler) */
3306 o = (StgClosure *)allocate(sizeofW(StgClosure)+2);
3307 TICK_ALLOC_FUN(2,0);
3308 SET_HDR(o,&stg_catch_info,su->header.prof.ccs /* ToDo */);
3309 o->payload[0] = (StgClosure *)ap;
3310 o->payload[1] = cf->handler;
3313 fprintf(stderr, "scheduler: Built ");
3314 printObj((StgClosure *)o);
3317 /* pop the old handler and put o on the stack */
3319 sp += sizeofW(StgCatchFrame) - 1;
3326 StgSeqFrame *sf = (StgSeqFrame *)su;
3329 SET_HDR(ap,&stg_PAP_info,su->header.prof.ccs /* ToDo */);
3330 TICK_ALLOC_UPD_PAP(words+1,0);
3332 /* now build o = FUN(seq,ap) */
3333 o = (StgClosure *)allocate(sizeofW(StgClosure)+1);
3334 TICK_ALLOC_SE_THK(1,0);
3335 SET_HDR(o,&stg_seq_info,su->header.prof.ccs /* ToDo */);
3336 o->payload[0] = (StgClosure *)ap;
3339 fprintf(stderr, "scheduler: Built ");
3340 printObj((StgClosure *)o);
3343 /* pop the old handler and put o on the stack */
3345 sp += sizeofW(StgSeqFrame) - 1;
3351 /* We've stripped the entire stack, the thread is now dead. */
3352 sp += sizeofW(StgStopFrame) - 1;
3353 sp[0] = (W_)exception; /* save the exception */
3354 tso->what_next = ThreadKilled;
3355 tso->su = (StgUpdateFrame *)(sp+1);
3366 /* -----------------------------------------------------------------------------
3367 resurrectThreads is called after garbage collection on the list of
3368 threads found to be garbage. Each of these threads will be woken
3369 up and sent a signal: BlockedOnDeadMVar if the thread was blocked
3370 on an MVar, or NonTermination if the thread was blocked on a Black
3373 Locks: sched_mutex isn't held upon entry nor exit.
3374 -------------------------------------------------------------------------- */
3377 resurrectThreads( StgTSO *threads )
3381 for (tso = threads; tso != END_TSO_QUEUE; tso = next) {
3382 next = tso->global_link;
3383 tso->global_link = all_threads;
3385 IF_DEBUG(scheduler, sched_belch("resurrecting thread %d", tso->id));
3387 switch (tso->why_blocked) {
3389 case BlockedOnException:
3390 /* Called by GC - sched_mutex lock is currently held. */
3391 raiseAsync(tso,(StgClosure *)BlockedOnDeadMVar_closure);
3393 case BlockedOnBlackHole:
3394 raiseAsync(tso,(StgClosure *)NonTermination_closure);
3397 /* This might happen if the thread was blocked on a black hole
3398 * belonging to a thread that we've just woken up (raiseAsync
3399 * can wake up threads, remember...).
3403 barf("resurrectThreads: thread blocked in a strange way");
3408 /* -----------------------------------------------------------------------------
3409 * Blackhole detection: if we reach a deadlock, test whether any
3410 * threads are blocked on themselves. Any threads which are found to
3411 * be self-blocked get sent a NonTermination exception.
3413 * This is only done in a deadlock situation in order to avoid
3414 * performance overhead in the normal case.
3416 * Locks: sched_mutex is held upon entry and exit.
3417 * -------------------------------------------------------------------------- */
3420 detectBlackHoles( void )
3422 StgTSO *t = all_threads;
3423 StgUpdateFrame *frame;
3424 StgClosure *blocked_on;
3426 for (t = all_threads; t != END_TSO_QUEUE; t = t->global_link) {
3428 while (t->what_next == ThreadRelocated) {
3430 ASSERT(get_itbl(t)->type == TSO);
3433 if (t->why_blocked != BlockedOnBlackHole) {
3437 blocked_on = t->block_info.closure;
3439 for (frame = t->su; ; frame = frame->link) {
3440 switch (get_itbl(frame)->type) {
3443 if (frame->updatee == blocked_on) {
3444 /* We are blocking on one of our own computations, so
3445 * send this thread the NonTermination exception.
3448 sched_belch("thread %d is blocked on itself", t->id));
3449 raiseAsync(t, (StgClosure *)NonTermination_closure);
3470 //@node Debugging Routines, Index, Exception Handling Routines, Main scheduling code
3471 //@subsection Debugging Routines
3473 /* -----------------------------------------------------------------------------
3474 Debugging: why is a thread blocked
3475 -------------------------------------------------------------------------- */
3480 printThreadBlockage(StgTSO *tso)
3482 switch (tso->why_blocked) {
3484 fprintf(stderr,"is blocked on read from fd %d", tso->block_info.fd);
3486 case BlockedOnWrite:
3487 fprintf(stderr,"is blocked on write to fd %d", tso->block_info.fd);
3489 case BlockedOnDelay:
3490 fprintf(stderr,"is blocked until %d", tso->block_info.target);
3493 fprintf(stderr,"is blocked on an MVar");
3495 case BlockedOnException:
3496 fprintf(stderr,"is blocked on delivering an exception to thread %d",
3497 tso->block_info.tso->id);
3499 case BlockedOnBlackHole:
3500 fprintf(stderr,"is blocked on a black hole");
3503 fprintf(stderr,"is not blocked");
3507 fprintf(stderr,"is blocked on global address; local FM_BQ is %p (%s)",
3508 tso->block_info.closure, info_type(tso->block_info.closure));
3510 case BlockedOnGA_NoSend:
3511 fprintf(stderr,"is blocked on global address (no send); local FM_BQ is %p (%s)",
3512 tso->block_info.closure, info_type(tso->block_info.closure));
3515 #if defined(RTS_SUPPORTS_THREADS)
3516 case BlockedOnCCall:
3517 fprintf(stderr,"is blocked on an external call");
3521 barf("printThreadBlockage: strange tso->why_blocked: %d for TSO %d (%d)",
3522 tso->why_blocked, tso->id, tso);
3527 printThreadStatus(StgTSO *tso)
3529 switch (tso->what_next) {
3531 fprintf(stderr,"has been killed");
3533 case ThreadComplete:
3534 fprintf(stderr,"has completed");
3537 printThreadBlockage(tso);
3542 printAllThreads(void)
3547 char time_string[TIME_STR_LEN], node_str[NODE_STR_LEN];
3548 ullong_format_string(TIME_ON_PROC(CurrentProc),
3549 time_string, rtsFalse/*no commas!*/);
3551 sched_belch("all threads at [%s]:", time_string);
3553 char time_string[TIME_STR_LEN], node_str[NODE_STR_LEN];
3554 ullong_format_string(CURRENT_TIME,
3555 time_string, rtsFalse/*no commas!*/);
3557 sched_belch("all threads at [%s]:", time_string);
3559 sched_belch("all threads:");
3562 for (t = all_threads; t != END_TSO_QUEUE; t = t->global_link) {
3563 fprintf(stderr, "\tthread %d ", t->id);
3564 if (t->label) fprintf(stderr,"[\"%s\"] ",t->label);
3565 printThreadStatus(t);
3566 fprintf(stderr,"\n");
3571 Print a whole blocking queue attached to node (debugging only).
3576 print_bq (StgClosure *node)
3578 StgBlockingQueueElement *bqe;
3582 fprintf(stderr,"## BQ of closure %p (%s): ",
3583 node, info_type(node));
3585 /* should cover all closures that may have a blocking queue */
3586 ASSERT(get_itbl(node)->type == BLACKHOLE_BQ ||
3587 get_itbl(node)->type == FETCH_ME_BQ ||
3588 get_itbl(node)->type == RBH ||
3589 get_itbl(node)->type == MVAR);
3591 ASSERT(node!=(StgClosure*)NULL); // sanity check
3593 print_bqe(((StgBlockingQueue*)node)->blocking_queue);
3597 Print a whole blocking queue starting with the element bqe.
3600 print_bqe (StgBlockingQueueElement *bqe)
3605 NB: In a parallel setup a BQ of an RBH must end with an RBH_Save closure;
3607 for (end = (bqe==END_BQ_QUEUE);
3608 !end; // iterate until bqe points to a CONSTR
3609 end = (get_itbl(bqe)->type == CONSTR) || (bqe->link==END_BQ_QUEUE),
3610 bqe = end ? END_BQ_QUEUE : bqe->link) {
3611 ASSERT(bqe != END_BQ_QUEUE); // sanity check
3612 ASSERT(bqe != (StgBlockingQueueElement *)NULL); // sanity check
3613 /* types of closures that may appear in a blocking queue */
3614 ASSERT(get_itbl(bqe)->type == TSO ||
3615 get_itbl(bqe)->type == BLOCKED_FETCH ||
3616 get_itbl(bqe)->type == CONSTR);
3617 /* only BQs of an RBH end with an RBH_Save closure */
3618 //ASSERT(get_itbl(bqe)->type != CONSTR || get_itbl(node)->type == RBH);
3620 switch (get_itbl(bqe)->type) {
3622 fprintf(stderr," TSO %u (%x),",
3623 ((StgTSO *)bqe)->id, ((StgTSO *)bqe));
3626 fprintf(stderr," BF (node=%p, ga=((%x, %d, %x)),",
3627 ((StgBlockedFetch *)bqe)->node,
3628 ((StgBlockedFetch *)bqe)->ga.payload.gc.gtid,
3629 ((StgBlockedFetch *)bqe)->ga.payload.gc.slot,
3630 ((StgBlockedFetch *)bqe)->ga.weight);
3633 fprintf(stderr," %s (IP %p),",
3634 (get_itbl(bqe) == &stg_RBH_Save_0_info ? "RBH_Save_0" :
3635 get_itbl(bqe) == &stg_RBH_Save_1_info ? "RBH_Save_1" :
3636 get_itbl(bqe) == &stg_RBH_Save_2_info ? "RBH_Save_2" :
3637 "RBH_Save_?"), get_itbl(bqe));
3640 barf("Unexpected closure type %s in blocking queue", // of %p (%s)",
3641 info_type((StgClosure *)bqe)); // , node, info_type(node));
3645 fputc('\n', stderr);
3647 # elif defined(GRAN)
3649 print_bq (StgClosure *node)
3651 StgBlockingQueueElement *bqe;
3652 PEs node_loc, tso_loc;
3655 /* should cover all closures that may have a blocking queue */
3656 ASSERT(get_itbl(node)->type == BLACKHOLE_BQ ||
3657 get_itbl(node)->type == FETCH_ME_BQ ||
3658 get_itbl(node)->type == RBH);
3660 ASSERT(node!=(StgClosure*)NULL); // sanity check
3661 node_loc = where_is(node);
3663 fprintf(stderr,"## BQ of closure %p (%s) on [PE %d]: ",
3664 node, info_type(node), node_loc);
3667 NB: In a parallel setup a BQ of an RBH must end with an RBH_Save closure;
3669 for (bqe = ((StgBlockingQueue*)node)->blocking_queue, end = (bqe==END_BQ_QUEUE);
3670 !end; // iterate until bqe points to a CONSTR
3671 end = (get_itbl(bqe)->type == CONSTR) || (bqe->link==END_BQ_QUEUE), bqe = end ? END_BQ_QUEUE : bqe->link) {
3672 ASSERT(bqe != END_BQ_QUEUE); // sanity check
3673 ASSERT(bqe != (StgBlockingQueueElement *)NULL); // sanity check
3674 /* types of closures that may appear in a blocking queue */
3675 ASSERT(get_itbl(bqe)->type == TSO ||
3676 get_itbl(bqe)->type == CONSTR);
3677 /* only BQs of an RBH end with an RBH_Save closure */
3678 ASSERT(get_itbl(bqe)->type != CONSTR || get_itbl(node)->type == RBH);
3680 tso_loc = where_is((StgClosure *)bqe);
3681 switch (get_itbl(bqe)->type) {
3683 fprintf(stderr," TSO %d (%p) on [PE %d],",
3684 ((StgTSO *)bqe)->id, (StgTSO *)bqe, tso_loc);
3687 fprintf(stderr," %s (IP %p),",
3688 (get_itbl(bqe) == &stg_RBH_Save_0_info ? "RBH_Save_0" :
3689 get_itbl(bqe) == &stg_RBH_Save_1_info ? "RBH_Save_1" :
3690 get_itbl(bqe) == &stg_RBH_Save_2_info ? "RBH_Save_2" :
3691 "RBH_Save_?"), get_itbl(bqe));
3694 barf("Unexpected closure type %s in blocking queue of %p (%s)",
3695 info_type((StgClosure *)bqe), node, info_type(node));
3699 fputc('\n', stderr);
3703 Nice and easy: only TSOs on the blocking queue
3706 print_bq (StgClosure *node)
3710 ASSERT(node!=(StgClosure*)NULL); // sanity check
3711 for (tso = ((StgBlockingQueue*)node)->blocking_queue;
3712 tso != END_TSO_QUEUE;
3714 ASSERT(tso!=NULL && tso!=END_TSO_QUEUE); // sanity check
3715 ASSERT(get_itbl(tso)->type == TSO); // guess what, sanity check
3716 fprintf(stderr," TSO %d (%p),", tso->id, tso);
3718 fputc('\n', stderr);
3729 for (i=0, tso=run_queue_hd;
3730 tso != END_TSO_QUEUE;
3739 sched_belch(char *s, ...)
3744 fprintf(stderr, "scheduler (task %ld): ", osThreadId());
3746 fprintf(stderr, "== ");
3748 fprintf(stderr, "scheduler: ");
3750 vfprintf(stderr, s, ap);
3751 fprintf(stderr, "\n");
3757 //@node Index, , Debugging Routines, Main scheduling code
3761 //* StgMainThread:: @cindex\s-+StgMainThread
3762 //* awaken_blocked_queue:: @cindex\s-+awaken_blocked_queue
3763 //* blocked_queue_hd:: @cindex\s-+blocked_queue_hd
3764 //* blocked_queue_tl:: @cindex\s-+blocked_queue_tl
3765 //* context_switch:: @cindex\s-+context_switch
3766 //* createThread:: @cindex\s-+createThread
3767 //* gc_pending_cond:: @cindex\s-+gc_pending_cond
3768 //* initScheduler:: @cindex\s-+initScheduler
3769 //* interrupted:: @cindex\s-+interrupted
3770 //* next_thread_id:: @cindex\s-+next_thread_id
3771 //* print_bq:: @cindex\s-+print_bq
3772 //* run_queue_hd:: @cindex\s-+run_queue_hd
3773 //* run_queue_tl:: @cindex\s-+run_queue_tl
3774 //* sched_mutex:: @cindex\s-+sched_mutex
3775 //* schedule:: @cindex\s-+schedule
3776 //* take_off_run_queue:: @cindex\s-+take_off_run_queue
3777 //* term_mutex:: @cindex\s-+term_mutex