X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=ghc%2Frts%2FSchedule.c;h=71c3ec933733518a45574eecf6f77dfedad85730;hb=048304d347f5d18b60d8b346ff2ad9c6666a9b35;hp=44a156b14efaeda223d3a836278abc3ec3545539;hpb=a20ec0ced36bca7cd0594528922dbe31a6186eae;p=ghc-hetmet.git diff --git a/ghc/rts/Schedule.c b/ghc/rts/Schedule.c index 44a156b..71c3ec9 100644 --- a/ghc/rts/Schedule.c +++ b/ghc/rts/Schedule.c @@ -1,7 +1,6 @@ /* --------------------------------------------------------------------------- - * $Id: Schedule.c,v 1.193 2004/03/01 14:18:35 simonmar Exp $ * - * (c) The GHC Team, 1998-2003 + * (c) The GHC Team, 1998-2004 * * Scheduler * @@ -42,9 +41,9 @@ #include "SchedAPI.h" #include "RtsUtils.h" #include "RtsFlags.h" +#include "BlockAlloc.h" #include "Storage.h" #include "StgRun.h" -#include "StgStartup.h" #include "Hooks.h" #define COMPILING_SCHEDULER #include "Schedule.h" @@ -59,6 +58,8 @@ #include "Timer.h" #include "Prelude.h" #include "ThreadLabels.h" +#include "LdvProfile.h" +#include "Updates.h" #ifdef PROFILING #include "Proftimer.h" #include "ProfHeap.h" @@ -234,6 +235,7 @@ rtsBool emitSchedule = rtsTrue; #if DEBUG static char *whatNext_strs[] = { + "(unknown)", "ThreadRunGHC", "ThreadInterpret", "ThreadKilled", @@ -276,7 +278,10 @@ startSchedulerTaskIfNecessary(void) // just because the last one hasn't yet reached the // "waiting for capability" state startingWorkerThread = rtsTrue; - startTask(taskStart); + if(!startTask(taskStart)) + { + startingWorkerThread = rtsFalse; + } } } } @@ -337,7 +342,7 @@ schedule( StgMainThread *mainThread USED_WHEN_RTS_SUPPORTS_THREADS, # endif #endif rtsBool was_interrupted = rtsFalse; - StgTSOWhatNext prev_what_next; + nat prev_what_next; // Pre-condition: sched_mutex is held. // We might have a capability, passed in as initialCapability. @@ -876,8 +881,6 @@ schedule( StgMainThread *mainThread USED_WHEN_RTS_SUPPORTS_THREADS, || blocked_queue_hd != END_TSO_QUEUE || sleeping_queue != END_TSO_QUEUE))) context_switch = 1; - else - context_switch = 0; run_thread: @@ -894,23 +897,35 @@ run_thread: /* Run the current thread */ prev_what_next = t->what_next; + + errno = t->saved_errno; + switch (prev_what_next) { + case ThreadKilled: case ThreadComplete: /* Thread already finished, return to scheduler. */ ret = ThreadFinished; break; + case ThreadRunGHC: - errno = t->saved_errno; ret = StgRun((StgFunPtr) stg_returnToStackTop, &cap->r); - t->saved_errno = errno; break; + case ThreadInterpret: ret = interpretBCO(cap); break; + default: barf("schedule: invalid what_next field"); } + + // The TSO might have moved, so find the new location: + t = cap->r.rCurrentTSO; + + // And save the current errno in this thread. + t->saved_errno = errno; + /* +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ */ /* Costs for the scheduler are assigned to CCS_SYSTEM */ @@ -926,7 +941,6 @@ run_thread: #elif !defined(GRAN) && !defined(PAR) IF_DEBUG(scheduler,fprintf(stderr,"sched: ");); #endif - t = cap->r.rCurrentTSO; #if defined(PAR) /* HACK 675: if the last thread didn't yield, make sure to print a @@ -946,12 +960,12 @@ run_thread: #endif // did the task ask for a large block? - if (cap->r.rHpAlloc > BLOCK_SIZE_W) { + if (cap->r.rHpAlloc > BLOCK_SIZE) { // if so, get one and push it on the front of the nursery. bdescr *bd; nat blocks; - blocks = (nat)BLOCK_ROUND_UP(cap->r.rHpAlloc * sizeof(W_)) / BLOCK_SIZE; + blocks = (nat)BLOCK_ROUND_UP(cap->r.rHpAlloc) / BLOCK_SIZE; IF_DEBUG(scheduler,belch("--<< thread %ld (%s) stopped: requesting a large block (size %d)", t->id, whatNext_strs[t->what_next], blocks)); @@ -1062,12 +1076,19 @@ run_thread: if (t->main != NULL) { t->main->tso = new_t; } - threadPaused(new_t); PUSH_ON_RUN_QUEUE(new_t); } break; case ThreadYielding: + // Reset the context switch flag. We don't do this just before + // running the thread, because that would mean we would lose ticks + // during GC, which can lead to unfair scheduling (a thread hogs + // the CPU because the tick always arrives during GC). This way + // penalises threads that do a lot of allocation, but that seems + // better than the alternative. + context_switch = 0; + #if defined(GRAN) IF_DEBUG(gran, DumpGranEvent(GR_DESCHEDULE, t)); @@ -1380,13 +1401,22 @@ isThreadBound(StgTSO* tso USED_IN_THREADED_RTS) * Singleton fork(). Do not copy any running threads. * ------------------------------------------------------------------------- */ +#ifndef mingw32_TARGET_OS +#define FORKPROCESS_PRIMOP_SUPPORTED +#endif + +#ifdef FORKPROCESS_PRIMOP_SUPPORTED static void deleteThreadImmediately(StgTSO *tso); - +#endif StgInt -forkProcess(HsStablePtr *entry) +forkProcess(HsStablePtr *entry +#ifndef FORKPROCESS_PRIMOP_SUPPORTED + STG_UNUSED +#endif + ) { -#ifndef mingw32_TARGET_OS +#ifdef FORKPROCESS_PRIMOP_SUPPORTED pid_t pid; StgTSO* t,*next; StgMainThread *m; @@ -1420,17 +1450,17 @@ forkProcess(HsStablePtr *entry) // wipe the main thread list while((m = main_threads) != NULL) { main_threads = m->link; -#ifdef THREADED_RTS +# ifdef THREADED_RTS closeCondition(&m->bound_thread_cond); -#endif +# endif stgFree(m); } -#ifdef RTS_SUPPORTS_THREADS +# ifdef RTS_SUPPORTS_THREADS resetTaskManagerAfterFork(); // tell startTask() and friends that startingWorkerThread = rtsFalse; // we have no worker threads any more resetWorkerWakeupPipeAfterFork(); -#endif +# endif rc = rts_evalStableIO(entry, NULL); // run the action rts_checkSchedStatus("forkProcess",rc); @@ -1440,10 +1470,10 @@ forkProcess(HsStablePtr *entry) hs_exit(); // clean up and exit stg_exit(0); } -#else /* mingw32 */ - barf("forkProcess#: primop not implemented for mingw32, sorry!\n"); +#else /* !FORKPROCESS_PRIMOP_SUPPORTED */ + barf("forkProcess#: primop not supported, sorry!\n"); return -1; -#endif /* mingw32 */ +#endif } /* --------------------------------------------------------------------------- @@ -1464,9 +1494,15 @@ deleteAllThreads ( void ) next = t->global_link; deleteThread(t); } - run_queue_hd = run_queue_tl = END_TSO_QUEUE; - blocked_queue_hd = blocked_queue_tl = END_TSO_QUEUE; - sleeping_queue = END_TSO_QUEUE; + + // The run queue now contains a bunch of ThreadKilled threads. We + // must not throw these away: the main thread(s) will be in there + // somewhere, and the main scheduler loop has to deal with it. + // Also, the run queue is the only thing keeping these threads from + // being GC'd, and we don't want the "main thread has been GC'd" panic. + + ASSERT(blocked_queue_hd == END_TSO_QUEUE); + ASSERT(sleeping_queue == END_TSO_QUEUE); } /* startThread and insertThread are now in GranSim.c -- HWL */ @@ -1488,12 +1524,7 @@ deleteAllThreads ( void ) * ------------------------------------------------------------------------- */ StgInt -suspendThread( StgRegTable *reg, - rtsBool concCall -#if !defined(DEBUG) - STG_UNUSED -#endif - ) +suspendThread( StgRegTable *reg ) { nat tok; Capability *cap; @@ -1507,7 +1538,7 @@ suspendThread( StgRegTable *reg, ACQUIRE_LOCK(&sched_mutex); IF_DEBUG(scheduler, - sched_belch("thread %d did a _ccall_gc (is_concurrent: %d)", cap->r.rCurrentTSO->id,concCall)); + sched_belch("thread %d did a _ccall_gc", cap->r.rCurrentTSO->id)); // XXX this might not be necessary --SDM cap->r.rCurrentTSO->what_next = ThreadRunGHC; @@ -1545,8 +1576,7 @@ suspendThread( StgRegTable *reg, } StgRegTable * -resumeThread( StgInt tok, - rtsBool concCall STG_UNUSED ) +resumeThread( StgInt tok ) { StgTSO *tso, **prev; Capability *cap; @@ -1723,9 +1753,10 @@ createThread(nat size) /* put a stop frame on the stack */ tso->sp -= sizeofW(StgStopFrame); SET_HDR((StgClosure*)tso->sp,(StgInfoTable *)&stg_stop_thread_info,CCS_SYSTEM); + tso->link = END_TSO_QUEUE; + // ToDo: check this #if defined(GRAN) - tso->link = END_TSO_QUEUE; /* uses more flexible routine in GranSim */ insertThread(tso, CurrentProc); #else @@ -1902,7 +1933,9 @@ void scheduleThread_(StgTSO *tso) { // Precondition: sched_mutex must be held. - PUSH_ON_RUN_QUEUE(tso); + // The thread goes at the *end* of the run-queue, to avoid possible + // starvation of any threads already on the queue. + APPEND_TO_RUN_QUEUE(tso); THREAD_RUNNABLE(); } @@ -1962,7 +1995,7 @@ scheduleWaitThread(StgTSO* tso, /*[out]*/HaskellObj* ret, */ IF_DEBUG(scheduler, sched_belch("waiting for thread (%d)", tso->id)); - PUSH_ON_RUN_QUEUE(tso); + APPEND_TO_RUN_QUEUE(tso); // NB. Don't call THREAD_RUNNABLE() here, because the thread is // bound and only runnable by *this* OS thread, so waking up other // workers will just slow things down. @@ -2392,8 +2425,8 @@ unblockOneLocked(StgBlockingQueueElement *bqe, StgClosure *node) ASSERT(((StgTSO *)bqe)->why_blocked != NotBlocked); /* if it's a TSO just push it onto the run_queue */ next = bqe->link; - // ((StgTSO *)bqe)->link = END_TSO_QUEUE; // debugging? - PUSH_ON_RUN_QUEUE((StgTSO *)bqe); + ((StgTSO *)bqe)->link = END_TSO_QUEUE; // debugging? + APPEND_TO_RUN_QUEUE((StgTSO *)bqe); THREAD_RUNNABLE(); unblockCount(bqe, node); /* reset blocking status after dumping event */ @@ -2437,7 +2470,8 @@ unblockOneLocked(StgTSO *tso) ASSERT(tso->why_blocked != NotBlocked); tso->why_blocked = NotBlocked; next = tso->link; - PUSH_ON_RUN_QUEUE(tso); + tso->link = END_TSO_QUEUE; + APPEND_TO_RUN_QUEUE(tso); THREAD_RUNNABLE(); IF_DEBUG(scheduler,sched_belch("waking up thread %ld", tso->id)); return next; @@ -2887,7 +2921,7 @@ unblockThread(StgTSO *tso) tso->link = END_TSO_QUEUE; tso->why_blocked = NotBlocked; tso->block_info.closure = NULL; - PUSH_ON_RUN_QUEUE(tso); + APPEND_TO_RUN_QUEUE(tso); } #endif @@ -2931,6 +2965,7 @@ deleteThread(StgTSO *tso) raiseAsync(tso,NULL); } +#ifdef FORKPROCESS_PRIMOP_SUPPORTED static void deleteThreadImmediately(StgTSO *tso) { // for forkProcess only: @@ -2947,6 +2982,7 @@ deleteThreadImmediately(StgTSO *tso) tso->what_next = ThreadKilled; } +#endif void raiseAsyncWithLock(StgTSO *tso, StgClosure *exception) @@ -3105,7 +3141,8 @@ raiseAsync(StgTSO *tso, StgClosure *exception) // if (!closure_IND(((StgUpdateFrame *)frame)->updatee)) { // revert the black hole - UPD_IND_NOLOCK(((StgUpdateFrame *)frame)->updatee,ap); + UPD_IND_NOLOCK(((StgUpdateFrame *)frame)->updatee, + (StgClosure *)ap); } sp += sizeofW(StgUpdateFrame) - 1; sp[0] = (W_)ap; // push onto stack @@ -3127,6 +3164,77 @@ raiseAsync(StgTSO *tso, StgClosure *exception) } /* ----------------------------------------------------------------------------- + raiseExceptionHelper + + This function is called by the raise# primitve, just so that we can + move some of the tricky bits of raising an exception from C-- into + C. Who knows, it might be a useful re-useable thing here too. + -------------------------------------------------------------------------- */ + +StgWord +raiseExceptionHelper (StgTSO *tso, StgClosure *exception) +{ + StgClosure *raise_closure = NULL; + StgPtr p, next; + StgRetInfoTable *info; + // + // This closure represents the expression 'raise# E' where E + // is the exception raise. It is used to overwrite all the + // thunks which are currently under evaluataion. + // + + // + // LDV profiling: stg_raise_info has THUNK as its closure + // type. Since a THUNK takes at least MIN_UPD_SIZE words in its + // payload, MIN_UPD_SIZE is more approprate than 1. It seems that + // 1 does not cause any problem unless profiling is performed. + // However, when LDV profiling goes on, we need to linearly scan + // small object pool, where raise_closure is stored, so we should + // use MIN_UPD_SIZE. + // + // raise_closure = (StgClosure *)RET_STGCALL1(P_,allocate, + // sizeofW(StgClosure)+1); + // + + // + // Walk up the stack, looking for the catch frame. On the way, + // we update any closures pointed to from update frames with the + // raise closure that we just built. + // + p = tso->sp; + while(1) { + info = get_ret_itbl((StgClosure *)p); + next = p + stack_frame_sizeW((StgClosure *)p); + switch (info->i.type) { + + case UPDATE_FRAME: + // Only create raise_closure if we need to. + if (raise_closure == NULL) { + raise_closure = + (StgClosure *)allocate(sizeofW(StgClosure)+MIN_UPD_SIZE); + SET_HDR(raise_closure, &stg_raise_info, CCCS); + raise_closure->payload[0] = exception; + } + UPD_IND(((StgUpdateFrame *)p)->updatee,raise_closure); + p = next; + continue; + + case CATCH_FRAME: + tso->sp = p; + return CATCH_FRAME; + + case STOP_FRAME: + tso->sp = p; + return STOP_FRAME; + + default: + p = next; + continue; + } + } +} + +/* ----------------------------------------------------------------------------- resurrectThreads is called after garbage collection on the list of threads found to be garbage. Each of these threads will be woken up and sent a signal: BlockedOnDeadMVar if the thread was blocked