X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=ghc%2Frts%2FSchedule.c;h=21bd59be0dc52364a1b1b90847eee3e1ec1e2af7;hb=1828f852e0da737d285bfbfce3bfac26203f4ef5;hp=bfac5745003ef1872dcfc958212d2629c6b0b95d;hpb=5000229d351d1ae209bc7a6ab87c796fcb0c1576;p=ghc-hetmet.git diff --git a/ghc/rts/Schedule.c b/ghc/rts/Schedule.c index bfac574..21bd59b 100644 --- a/ghc/rts/Schedule.c +++ b/ghc/rts/Schedule.c @@ -1,41 +1,11 @@ /* --------------------------------------------------------------------------- * - * (c) The GHC Team, 1998-2004 + * (c) The GHC Team, 1998-2005 * - * Scheduler - * - * Different GHC ways use this scheduler quite differently (see comments below) - * Here is the global picture: - * - * WAY Name CPP flag What's it for - * -------------------------------------- - * mp GUM PARALLEL_HASKELL Parallel execution on a distrib. memory machine - * s SMP SMP Parallel execution on a shared memory machine - * mg GranSim GRAN Simulation of parallel execution - * md GUM/GdH DIST Distributed execution (based on GUM) + * The scheduler and thread-related functionality * * --------------------------------------------------------------------------*/ -/* - * Version with support for distributed memory parallelism aka GUM (WAY=mp): - - The main scheduling loop in GUM iterates until a finish message is received. - In that case a global flag @receivedFinish@ is set and this instance of - the RTS shuts down. See ghc/rts/parallel/HLComms.c:processMessages() - for the handling of incoming messages, such as PP_FINISH. - Note that in the parallel case we have a system manager that coordinates - different PEs, each of which are running one instance of the RTS. - See ghc/rts/parallel/SysMan.c for the main routine of the parallel program. - From this routine processes executing ghc/rts/Main.c are spawned. -- HWL - - * Version with support for simulating parallel execution aka GranSim (WAY=mg): - - The main scheduling code in GranSim is quite different from that in std - (concurrent) Haskell: while concurrent Haskell just iterates over the - threads in the runnable queue, GranSim is event driven, i.e. it iterates - over the events in the global event queue. -- HWL -*/ - #include "PosixSource.h" #include "Rts.h" #include "SchedAPI.h" @@ -46,13 +16,12 @@ #include "Storage.h" #include "StgRun.h" #include "Hooks.h" -#define COMPILING_SCHEDULER #include "Schedule.h" #include "StgMiscClosures.h" #include "Interpreter.h" #include "Exception.h" #include "Printer.h" -#include "Signals.h" +#include "RtsSignals.h" #include "Sanity.h" #include "Stats.h" #include "STM.h" @@ -76,7 +45,11 @@ #endif #include "Sparks.h" #include "Capability.h" -#include "Task.h" +#include "Task.h" +#include "AwaitEvent.h" +#if defined(mingw32_HOST_OS) +#include "win32/IOManager.h" +#endif #ifdef HAVE_SYS_TYPES_H #include @@ -99,22 +72,9 @@ # define STATIC_INLINE static #endif -#ifdef THREADED_RTS -#define USED_IN_THREADED_RTS -#else -#define USED_IN_THREADED_RTS STG_UNUSED -#endif - -#ifdef RTS_SUPPORTS_THREADS -#define USED_WHEN_RTS_SUPPORTS_THREADS -#else -#define USED_WHEN_RTS_SUPPORTS_THREADS STG_UNUSED -#endif - -/* Main thread queue. - * Locks required: sched_mutex. - */ -StgMainThread *main_threads = NULL; +/* ----------------------------------------------------------------------------- + * Global variables + * -------------------------------------------------------------------------- */ #if defined(GRAN) @@ -138,61 +98,52 @@ StgTSO *ccalling_threadss[MAX_PROC]; #else /* !GRAN */ -/* Thread queues. - * Locks required: sched_mutex. - */ -StgTSO *run_queue_hd = NULL; -StgTSO *run_queue_tl = NULL; +#if !defined(THREADED_RTS) +// Blocked/sleeping thrads StgTSO *blocked_queue_hd = NULL; StgTSO *blocked_queue_tl = NULL; -StgTSO *blackhole_queue = NULL; -StgTSO *sleeping_queue = NULL; /* perhaps replace with a hash table? */ +StgTSO *sleeping_queue = NULL; // perhaps replace with a hash table? +#endif +/* Threads blocked on blackholes. + * LOCK: sched_mutex+capability, or all capabilities + */ +StgTSO *blackhole_queue = NULL; #endif /* The blackhole_queue should be checked for threads to wake up. See * Schedule.h for more thorough comment. + * LOCK: none (doesn't matter if we miss an update) */ rtsBool blackholes_need_checking = rtsFalse; /* Linked list of all threads. * Used for detecting garbage collected threads. + * LOCK: sched_mutex+capability, or all capabilities */ StgTSO *all_threads = NULL; -/* When a thread performs a safe C call (_ccall_GC, using old - * terminology), it gets put on the suspended_ccalling_threads - * list. Used by the garbage collector. +/* flag set by signal handler to precipitate a context switch + * LOCK: none (just an advisory flag) */ -static StgTSO *suspended_ccalling_threads; - -/* KH: The following two flags are shared memory locations. There is no need - to lock them, since they are only unset at the end of a scheduler - operation. -*/ - -/* flag set by signal handler to precipitate a context switch */ int context_switch = 0; -/* if this flag is set as well, give up execution */ -rtsBool interrupted = rtsFalse; +/* flag that tracks whether we have done any execution in this time slice. + * LOCK: currently none, perhaps we should lock (but needs to be + * updated in the fast path of the scheduler). + */ +nat recent_activity = ACTIVITY_YES; -/* If this flag is set, we are running Haskell code. Used to detect - * uses of 'foreign import unsafe' that should be 'safe'. +/* if this flag is set as well, give up execution + * LOCK: none (changes once, from false->true) */ -static rtsBool in_haskell = rtsFalse; +rtsBool interrupted = rtsFalse; /* Next thread ID to allocate. - * Locks required: thread_id_mutex + * LOCK: sched_mutex */ static StgThreadID next_thread_id = 1; -/* - * Pointers to the state of the current thread. - * Rule of thumb: if CurrentTSO != NULL, then we're running a Haskell - * thread. If CurrentTSO == NULL, then we're at the scheduler level. - */ - /* The smallest stack size that makes any sense is: * RESERVED_STACK_WORDS (so we can get back from the stack overflow) * + sizeofW(StgStopFrame) (the stg_stop_thread_info frame) @@ -203,10 +154,8 @@ static StgThreadID next_thread_id = 1; * A thread with this stack will bomb immediately with a stack * overflow, which will increase its stack size. */ - #define MIN_STACK_WORDS (RESERVED_STACK_WORDS + sizeofW(StgStopFrame) + 3) - #if defined(GRAN) StgTSO *CurrentTSO; #endif @@ -222,16 +171,15 @@ StgTSO dummy_tso; * in an MT setting, needed to signal that a worker thread shouldn't hang around * in the scheduler when it is out of work. */ -static rtsBool shutting_down_scheduler = rtsFalse; +rtsBool shutting_down_scheduler = rtsFalse; -#if defined(RTS_SUPPORTS_THREADS) -/* ToDo: carefully document the invariants that go together - * with these synchronisation objects. +/* + * This mutex protects most of the global scheduler data in + * the THREADED_RTS and (inc. SMP) runtime. */ -Mutex sched_mutex = INIT_MUTEX_VAR; -Mutex term_mutex = INIT_MUTEX_VAR; - -#endif /* RTS_SUPPORTS_THREADS */ +#if defined(THREADED_RTS) +Mutex sched_mutex; +#endif #if defined(PARALLEL_HASKELL) StgTSO *LastTSO; @@ -239,38 +187,25 @@ rtsTime TimeOfLastYield; rtsBool emitSchedule = rtsTrue; #endif -#if DEBUG -static char *whatNext_strs[] = { - "(unknown)", - "ThreadRunGHC", - "ThreadInterpret", - "ThreadKilled", - "ThreadRelocated", - "ThreadComplete" -}; -#endif - /* ----------------------------------------------------------------------------- * static function prototypes * -------------------------------------------------------------------------- */ -#if defined(RTS_SUPPORTS_THREADS) -static void taskStart(void); -#endif - -static void schedule( StgMainThread *mainThread USED_WHEN_RTS_SUPPORTS_THREADS, - Capability *initialCapability ); +static Capability *schedule (Capability *initialCapability, Task *task); // // These function all encapsulate parts of the scheduler loop, and are // abstracted only to make the structure and control flow of the // scheduler clearer. // -static void schedulePreLoop(void); -static void scheduleStartSignalHandlers(void); -static void scheduleCheckBlockedThreads(void); -static void scheduleCheckBlackHoles(void); -static void scheduleDetectDeadlock(void); +static void schedulePreLoop (void); +#if defined(SMP) +static void schedulePushWork(Capability *cap, Task *task); +#endif +static void scheduleStartSignalHandlers (Capability *cap); +static void scheduleCheckBlockedThreads (Capability *cap); +static void scheduleCheckBlackHoles (Capability *cap); +static void scheduleDetectDeadlock (Capability *cap, Task *task); #if defined(GRAN) static StgTSO *scheduleProcessEvent(rtsEvent *event); #endif @@ -284,68 +219,48 @@ static void scheduleGranParReport(void); #endif static void schedulePostRunThread(void); static rtsBool scheduleHandleHeapOverflow( Capability *cap, StgTSO *t ); -static void scheduleHandleStackOverflow( StgTSO *t); -static rtsBool scheduleHandleYield( StgTSO *t, nat prev_what_next ); +static void scheduleHandleStackOverflow( Capability *cap, Task *task, + StgTSO *t); +static rtsBool scheduleHandleYield( Capability *cap, StgTSO *t, + nat prev_what_next ); static void scheduleHandleThreadBlocked( StgTSO *t ); -static rtsBool scheduleHandleThreadFinished( StgMainThread *mainThread, - Capability *cap, StgTSO *t ); -static rtsBool scheduleDoHeapProfile(void); -static void scheduleDoGC(Capability *cap); - -static void unblockThread(StgTSO *tso); -static rtsBool checkBlackHoles(void); -static SchedulerStatus waitThread_(/*out*/StgMainThread* m, - Capability *initialCapability - ); -static void scheduleThread_ (StgTSO* tso); +static rtsBool scheduleHandleThreadFinished( Capability *cap, Task *task, + StgTSO *t ); +static rtsBool scheduleDoHeapProfile(rtsBool ready_to_gc); +static void scheduleDoGC(Capability *cap, Task *task, rtsBool force_major); + +static void unblockThread(Capability *cap, StgTSO *tso); +static rtsBool checkBlackHoles(Capability *cap); static void AllRoots(evac_fn evac); -static StgTSO *threadStackOverflow(StgTSO *tso); +static StgTSO *threadStackOverflow(Capability *cap, StgTSO *tso); -static void raiseAsync_(StgTSO *tso, StgClosure *exception, - rtsBool stop_at_atomically); +static void raiseAsync_(Capability *cap, StgTSO *tso, StgClosure *exception, + rtsBool stop_at_atomically, StgPtr stop_here); +static void deleteThread (Capability *cap, StgTSO *tso); +static void deleteRunQueue (Capability *cap); + +#ifdef DEBUG static void printThreadBlockage(StgTSO *tso); static void printThreadStatus(StgTSO *tso); +void printThreadQueue(StgTSO *tso); +#endif #if defined(PARALLEL_HASKELL) StgTSO * createSparkThread(rtsSpark spark); StgTSO * activateSpark (rtsSpark spark); #endif -/* ---------------------------------------------------------------------------- - * Starting Tasks - * ------------------------------------------------------------------------- */ - -#if defined(RTS_SUPPORTS_THREADS) -static rtsBool startingWorkerThread = rtsFalse; - -static void -taskStart(void) -{ - ACQUIRE_LOCK(&sched_mutex); - startingWorkerThread = rtsFalse; - schedule(NULL,NULL); - taskStop(); - RELEASE_LOCK(&sched_mutex); -} - -void -startSchedulerTaskIfNecessary(void) -{ - if ( !EMPTY_RUN_QUEUE() - && !shutting_down_scheduler // not if we're shutting down - && !startingWorkerThread) - { - // we don't want to start another worker thread - // just because the last one hasn't yet reached the - // "waiting for capability" state - startingWorkerThread = rtsTrue; - if (!maybeStartNewWorker(taskStart)) { - startingWorkerThread = rtsFalse; - } - } -} +#ifdef DEBUG +static char *whatNext_strs[] = { + "(unknown)", + "ThreadRunGHC", + "ThreadInterpret", + "ThreadKilled", + "ThreadRelocated", + "ThreadComplete" +}; #endif /* ----------------------------------------------------------------------------- @@ -353,22 +268,22 @@ startSchedulerTaskIfNecessary(void) * -------------------------------------------------------------------------- */ STATIC_INLINE void -addToRunQueue( StgTSO *t ) +addToRunQueue( Capability *cap, StgTSO *t ) { #if defined(PARALLEL_HASKELL) if (RtsFlags.ParFlags.doFairScheduling) { // this does round-robin scheduling; good for concurrency - APPEND_TO_RUN_QUEUE(t); + appendToRunQueue(cap,t); } else { // this does unfair scheduling; good for parallelism - PUSH_ON_RUN_QUEUE(t); + pushOnRunQueue(cap,t); } #else // this does round-robin scheduling; good for concurrency - APPEND_TO_RUN_QUEUE(t); + appendToRunQueue(cap,t); #endif } - + /* --------------------------------------------------------------------------- Main scheduling loop. @@ -381,13 +296,6 @@ addToRunQueue( StgTSO *t ) * thread ends * stack overflow - Locking notes: we acquire the scheduler lock once at the beginning - of the scheduler loop, and release it when - - * running a thread, or - * waiting for work, or - * waiting for a GC to complete. - GRAN version: In a GranSim setup this loop iterates over the global event queue. This revolves around the global event queue, which determines what @@ -405,9 +313,8 @@ addToRunQueue( StgTSO *t ) ------------------------------------------------------------------------ */ -static void -schedule( StgMainThread *mainThread USED_WHEN_RTS_SUPPORTS_THREADS, - Capability *initialCapability ) +static Capability * +schedule (Capability *initialCapability, Task *task) { StgTSO *t; Capability *cap; @@ -424,19 +331,19 @@ schedule( StgMainThread *mainThread USED_WHEN_RTS_SUPPORTS_THREADS, #endif nat prev_what_next; rtsBool ready_to_gc; +#if defined(THREADED_RTS) + rtsBool first = rtsTrue; +#endif - // Pre-condition: sched_mutex is held. - // We might have a capability, passed in as initialCapability. cap = initialCapability; -#if !defined(RTS_SUPPORTS_THREADS) - // simply initialise it in the non-threaded case - grabCapability(&cap); -#endif + // Pre-condition: this task owns initialCapability. + // The sched_mutex is *NOT* held + // NB. on return, we still hold a capability. IF_DEBUG(scheduler, - sched_belch("### NEW SCHEDULER LOOP (main thr: %p, cap: %p)", - mainThread, initialCapability); + sched_belch("### NEW SCHEDULER LOOP (task: %p, cap: %p)", + task, initialCapability); ); schedulePreLoop(); @@ -460,32 +367,30 @@ schedule( StgMainThread *mainThread USED_WHEN_RTS_SUPPORTS_THREADS, CurrentTSO = event->tso; #endif - IF_DEBUG(scheduler, printAllThreads()); - -#if defined(RTS_SUPPORTS_THREADS) - // Yield the capability to higher-priority tasks if necessary. - // - if (cap != NULL) { - yieldCapability(&cap); - } - - // If we do not currently hold a capability, we wait for one - // - if (cap == NULL) { - waitForCapability(&sched_mutex, &cap, - mainThread ? &mainThread->bound_thread_cond : NULL); +#if defined(THREADED_RTS) + if (first) { + // don't yield the first time, we want a chance to run this + // thread for a bit, even if there are others banging at the + // door. + first = rtsFalse; + ASSERT_FULL_CAPABILITY_INVARIANTS(cap,task); + } else { + // Yield the capability to higher-priority tasks if necessary. + yieldCapability(&cap, task); } - - // We now have a capability... +#endif + +#ifdef SMP + schedulePushWork(cap,task); #endif // Check whether we have re-entered the RTS from Haskell without // going via suspendThread()/resumeThread (i.e. a 'safe' foreign // call). - if (in_haskell) { + if (cap->in_haskell) { errorBelch("schedule: re-entered unsafely.\n" " Perhaps a 'foreign import unsafe' should be 'safe'?"); - stg_exit(1); + stg_exit(EXIT_FAILURE); } // @@ -495,53 +400,50 @@ schedule( StgMainThread *mainThread USED_WHEN_RTS_SUPPORTS_THREADS, // the threaded RTS. // if (interrupted) { + deleteRunQueue(cap); +#if defined(SMP) + discardSparksCap(cap); +#endif if (shutting_down_scheduler) { IF_DEBUG(scheduler, sched_belch("shutting down")); - releaseCapability(cap); - if (mainThread) { - mainThread->stat = Interrupted; - mainThread->ret = NULL; + // If we are a worker, just exit. If we're a bound thread + // then we will exit below when we've removed our TSO from + // the run queue. + if (task->tso == NULL && emptyRunQueue(cap)) { + return cap; } - return; } else { IF_DEBUG(scheduler, sched_belch("interrupted")); - deleteAllThreads(); } } -#if defined(not_yet) && defined(SMP) - // - // Top up the run queue from our spark pool. We try to make the - // number of threads in the run queue equal to the number of - // free capabilities. - // +#if defined(SMP) + // If the run queue is empty, take a spark and turn it into a thread. { - StgClosure *spark; - if (EMPTY_RUN_QUEUE()) { - spark = findSpark(rtsFalse); - if (spark == NULL) { - break; /* no more sparks in the pool */ - } else { - createSparkThread(spark); + if (emptyRunQueue(cap)) { + StgClosure *spark; + spark = findSpark(cap); + if (spark != NULL) { IF_DEBUG(scheduler, - sched_belch("==^^ turning spark of closure %p into a thread", + sched_belch("turning spark of closure %p into a thread", (StgClosure *)spark)); + createSparkThread(cap,spark); } } } #endif // SMP - scheduleStartSignalHandlers(); + scheduleStartSignalHandlers(cap); // Only check the black holes here if we've nothing else to do. // During normal execution, the black hole list only gets checked // at GC time, to avoid repeatedly traversing this possibly long // list each time around the scheduler. - if (EMPTY_RUN_QUEUE()) { scheduleCheckBlackHoles(); } + if (emptyRunQueue(cap)) { scheduleCheckBlackHoles(cap); } - scheduleCheckBlockedThreads(); + scheduleCheckBlockedThreads(cap); - scheduleDetectDeadlock(); + scheduleDetectDeadlock(cap,task); // Normally, the only way we can get here with no threads to // run is if a keyboard interrupt received during @@ -551,8 +453,8 @@ schedule( StgMainThread *mainThread USED_WHEN_RTS_SUPPORTS_THREADS, // // win32: might be here due to awaitEvent() being abandoned // as a result of a console event having been delivered. - if ( EMPTY_RUN_QUEUE() ) { -#if !defined(RTS_SUPPORTS_THREADS) && !defined(mingw32_HOST_OS) + if ( emptyRunQueue(cap) ) { +#if !defined(THREADED_RTS) && !defined(mingw32_HOST_OS) ASSERT(interrupted); #endif continue; // nothing to do @@ -560,7 +462,7 @@ schedule( StgMainThread *mainThread USED_WHEN_RTS_SUPPORTS_THREADS, #if defined(PARALLEL_HASKELL) scheduleSendPendingMessages(); - if (EMPTY_RUN_QUEUE() && scheduleActivateSpark()) + if (emptyRunQueue(cap) && scheduleActivateSpark()) continue; #if defined(SPARKS) @@ -569,7 +471,7 @@ schedule( StgMainThread *mainThread USED_WHEN_RTS_SUPPORTS_THREADS, /* If we still have no work we need to send a FISH to get a spark from another PE */ - if (EMPTY_RUN_QUEUE()) { + if (emptyRunQueue(cap)) { if (!scheduleGetRemoteWork(&receivedFinish)) continue; ASSERT(rtsFalse); // should not happen at the moment } @@ -590,8 +492,7 @@ schedule( StgMainThread *mainThread USED_WHEN_RTS_SUPPORTS_THREADS, // // Get a thread to run // - ASSERT(run_queue_hd != END_TSO_QUEUE); - POP_RUN_QUEUE(t); + t = popRunQueue(cap); #if defined(GRAN) || defined(PAR) scheduleGranParReport(); // some kind of debuging output @@ -601,63 +502,53 @@ schedule( StgMainThread *mainThread USED_WHEN_RTS_SUPPORTS_THREADS, IF_DEBUG(sanity,checkTSO(t)); #endif -#if defined(RTS_SUPPORTS_THREADS) +#if defined(THREADED_RTS) // Check whether we can run this thread in the current task. // If not, we have to pass our capability to the right task. { - StgMainThread *m = t->main; + Task *bound = t->bound; - if(m) - { - if(m == mainThread) - { - IF_DEBUG(scheduler, - sched_belch("### Running thread %d in bound thread", t->id)); - // yes, the Haskell thread is bound to the current native thread - } - else - { - IF_DEBUG(scheduler, - sched_belch("### thread %d bound to another OS thread", t->id)); - // no, bound to a different Haskell thread: pass to that thread - PUSH_ON_RUN_QUEUE(t); - passCapability(&m->bound_thread_cond); - continue; - } - } - else - { - if(mainThread != NULL) - // The thread we want to run is bound. - { - IF_DEBUG(scheduler, - sched_belch("### this OS thread cannot run thread %d", t->id)); - // no, the current native thread is bound to a different - // Haskell thread, so pass it to any worker thread - PUSH_ON_RUN_QUEUE(t); - passCapabilityToWorker(); - continue; + if (bound) { + if (bound == task) { + IF_DEBUG(scheduler, + sched_belch("### Running thread %d in bound thread", + t->id)); + // yes, the Haskell thread is bound to the current native thread + } else { + IF_DEBUG(scheduler, + sched_belch("### thread %d bound to another OS thread", + t->id)); + // no, bound to a different Haskell thread: pass to that thread + pushOnRunQueue(cap,t); + continue; + } + } else { + // The thread we want to run is unbound. + if (task->tso) { + IF_DEBUG(scheduler, + sched_belch("### this OS thread cannot run thread %d", t->id)); + // no, the current native thread is bound to a different + // Haskell thread, so pass it to any worker thread + pushOnRunQueue(cap,t); + continue; + } } - } } #endif cap->r.rCurrentTSO = t; - /* context switches are now initiated by the timer signal, unless + /* context switches are initiated by the timer signal, unless * the user specified "context switch as often as possible", with * +RTS -C0 */ - if ((RtsFlags.ConcFlags.ctxtSwitchTicks == 0 - && (run_queue_hd != END_TSO_QUEUE - || blocked_queue_hd != END_TSO_QUEUE - || sleeping_queue != END_TSO_QUEUE))) + if (RtsFlags.ConcFlags.ctxtSwitchTicks == 0 + && !emptyThreadQueues(cap)) { context_switch = 1; - + } + run_thread: - RELEASE_LOCK(&sched_mutex); - IF_DEBUG(scheduler, sched_belch("-->> running thread %ld %s ...", (long)t->id, whatNext_strs[t->what_next])); @@ -671,55 +562,81 @@ run_thread: prev_what_next = t->what_next; errno = t->saved_errno; - in_haskell = rtsTrue; + cap->in_haskell = rtsTrue; - switch (prev_what_next) { + recent_activity = ACTIVITY_YES; + switch (prev_what_next) { + case ThreadKilled: case ThreadComplete: /* Thread already finished, return to scheduler. */ ret = ThreadFinished; break; - + case ThreadRunGHC: - ret = StgRun((StgFunPtr) stg_returnToStackTop, &cap->r); + { + StgRegTable *r; + r = StgRun((StgFunPtr) stg_returnToStackTop, &cap->r); + cap = regTableToCapability(r); + ret = r->rRet; break; - + } + case ThreadInterpret: - ret = interpretBCO(cap); + cap = interpretBCO(cap); + ret = cap->r.rRet; break; - + default: - barf("schedule: invalid what_next field"); - } - - // We have run some Haskell code: there might be blackhole-blocked - // threads to wake up now. - if ( blackhole_queue != END_TSO_QUEUE ) { - blackholes_need_checking = rtsTrue; + barf("schedule: invalid what_next field"); } - in_haskell = rtsFalse; + cap->in_haskell = rtsFalse; // The TSO might have moved, eg. if it re-entered the RTS and a GC // happened. So find the new location: t = cap->r.rCurrentTSO; + // We have run some Haskell code: there might be blackhole-blocked + // threads to wake up now. + // Lock-free test here should be ok, we're just setting a flag. + if ( blackhole_queue != END_TSO_QUEUE ) { + blackholes_need_checking = rtsTrue; + } + // And save the current errno in this thread. + // XXX: possibly bogus for SMP because this thread might already + // be running again, see code below. t->saved_errno = errno; +#ifdef SMP + // If ret is ThreadBlocked, and this Task is bound to the TSO that + // blocked, we are in limbo - the TSO is now owned by whatever it + // is blocked on, and may in fact already have been woken up, + // perhaps even on a different Capability. It may be the case + // that task->cap != cap. We better yield this Capability + // immediately and return to normaility. + if (ret == ThreadBlocked) { + IF_DEBUG(scheduler, + sched_belch("--<< thread %d (%s) stopped: blocked\n", + t->id, whatNext_strs[t->what_next])); + continue; + } +#endif + + ASSERT_FULL_CAPABILITY_INVARIANTS(cap,task); + // ---------------------------------------------------------------------- - /* Costs for the scheduler are assigned to CCS_SYSTEM */ + // Costs for the scheduler are assigned to CCS_SYSTEM #if defined(PROFILING) stopHeapProfTimer(); CCCS = CCS_SYSTEM; #endif - ACQUIRE_LOCK(&sched_mutex); - -#if defined(RTS_SUPPORTS_THREADS) - IF_DEBUG(scheduler,debugBelch("sched (task %p): ", osThreadId());); +#if defined(THREADED_RTS) + IF_DEBUG(scheduler,debugBelch("sched (task %p): ", (void *)(unsigned long)(unsigned int)osThreadId());); #elif !defined(GRAN) && !defined(PARALLEL_HASKELL) IF_DEBUG(scheduler,debugBelch("sched: ");); #endif @@ -734,11 +651,11 @@ run_thread: break; case StackOverflow: - scheduleHandleStackOverflow(t); + scheduleHandleStackOverflow(cap,task,t); break; case ThreadYielding: - if (scheduleHandleYield(t, prev_what_next)) { + if (scheduleHandleYield(cap, t, prev_what_next)) { // shortcut for switching between compiler/interpreter: goto run_thread; } @@ -746,19 +663,19 @@ run_thread: case ThreadBlocked: scheduleHandleThreadBlocked(t); - threadPaused(t); break; case ThreadFinished: - if (scheduleHandleThreadFinished(mainThread, cap, t)) return;; + if (scheduleHandleThreadFinished(cap, task, t)) return cap; + ASSERT_FULL_CAPABILITY_INVARIANTS(cap,task); break; default: barf("schedule: invalid thread return code %d", (int)ret); } - if (scheduleDoHeapProfile()) { ready_to_gc = rtsFalse; } - if (ready_to_gc) { scheduleDoGC(cap); } + if (scheduleDoHeapProfile(ready_to_gc)) { ready_to_gc = rtsFalse; } + if (ready_to_gc) { scheduleDoGC(cap,task,rtsFalse); } } /* end of while() */ IF_PAR_DEBUG(verbose, @@ -767,7 +684,6 @@ run_thread: /* ---------------------------------------------------------------------------- * Setting up the scheduler loop - * ASSUMES: sched_mutex * ------------------------------------------------------------------------- */ static void @@ -792,78 +708,202 @@ schedulePreLoop(void) #endif } +/* ----------------------------------------------------------------------------- + * schedulePushWork() + * + * Push work to other Capabilities if we have some. + * -------------------------------------------------------------------------- */ + +#ifdef SMP +static void +schedulePushWork(Capability *cap USED_IF_SMP, + Task *task USED_IF_SMP) +{ + Capability *free_caps[n_capabilities], *cap0; + nat i, n_free_caps; + + // Check whether we have more threads on our run queue, or sparks + // in our pool, that we could hand to another Capability. + if ((emptyRunQueue(cap) || cap->run_queue_hd->link == END_TSO_QUEUE) + && sparkPoolSizeCap(cap) < 2) { + return; + } + + // First grab as many free Capabilities as we can. + for (i=0, n_free_caps=0; i < n_capabilities; i++) { + cap0 = &capabilities[i]; + if (cap != cap0 && tryGrabCapability(cap0,task)) { + if (!emptyRunQueue(cap0) || cap->returning_tasks_hd != NULL) { + // it already has some work, we just grabbed it at + // the wrong moment. Or maybe it's deadlocked! + releaseCapability(cap0); + } else { + free_caps[n_free_caps++] = cap0; + } + } + } + + // we now have n_free_caps free capabilities stashed in + // free_caps[]. Share our run queue equally with them. This is + // probably the simplest thing we could do; improvements we might + // want to do include: + // + // - giving high priority to moving relatively new threads, on + // the gournds that they haven't had time to build up a + // working set in the cache on this CPU/Capability. + // + // - giving low priority to moving long-lived threads + + if (n_free_caps > 0) { + StgTSO *prev, *t, *next; + rtsBool pushed_to_all; + + IF_DEBUG(scheduler, sched_belch("excess threads on run queue and %d free capabilities, sharing...", n_free_caps)); + + i = 0; + pushed_to_all = rtsFalse; + + if (cap->run_queue_hd != END_TSO_QUEUE) { + prev = cap->run_queue_hd; + t = prev->link; + prev->link = END_TSO_QUEUE; + for (; t != END_TSO_QUEUE; t = next) { + next = t->link; + t->link = END_TSO_QUEUE; + if (t->what_next == ThreadRelocated + || t->bound == task) { // don't move my bound thread + prev->link = t; + prev = t; + } else if (i == n_free_caps) { + pushed_to_all = rtsTrue; + i = 0; + // keep one for us + prev->link = t; + prev = t; + } else { + IF_DEBUG(scheduler, sched_belch("pushing thread %d to capability %d", t->id, free_caps[i]->no)); + appendToRunQueue(free_caps[i],t); + if (t->bound) { t->bound->cap = free_caps[i]; } + i++; + } + } + cap->run_queue_tl = prev; + } + + // If there are some free capabilities that we didn't push any + // threads to, then try to push a spark to each one. + if (!pushed_to_all) { + StgClosure *spark; + // i is the next free capability to push to + for (; i < n_free_caps; i++) { + if (emptySparkPoolCap(free_caps[i])) { + spark = findSpark(cap); + if (spark != NULL) { + IF_DEBUG(scheduler, sched_belch("pushing spark %p to capability %d", spark, free_caps[i]->no)); + newSpark(&(free_caps[i]->r), spark); + } + } + } + } + + // release the capabilities + for (i = 0; i < n_free_caps; i++) { + task->cap = free_caps[i]; + releaseCapability(free_caps[i]); + } + } + task->cap = cap; // reset to point to our Capability. +} +#endif + /* ---------------------------------------------------------------------------- * Start any pending signal handlers - * ASSUMES: sched_mutex * ------------------------------------------------------------------------- */ +#if defined(RTS_USER_SIGNALS) && (!defined(THREADED_RTS) || defined(mingw32_HOST_OS)) static void -scheduleStartSignalHandlers(void) +scheduleStartSignalHandlers(Capability *cap) { -#if defined(RTS_USER_SIGNALS) && !defined(RTS_SUPPORTS_THREADS) - if (signals_pending()) { - RELEASE_LOCK(&sched_mutex); /* ToDo: kill */ - startSignalHandlers(); - ACQUIRE_LOCK(&sched_mutex); + if (signals_pending()) { // safe outside the lock + startSignalHandlers(cap); } -#endif } +#else +static void +scheduleStartSignalHandlers(Capability *cap STG_UNUSED) +{ +} +#endif /* ---------------------------------------------------------------------------- * Check for blocked threads that can be woken up. - * ASSUMES: sched_mutex * ------------------------------------------------------------------------- */ static void -scheduleCheckBlockedThreads(void) +scheduleCheckBlockedThreads(Capability *cap USED_IF_NOT_THREADS) { +#if !defined(THREADED_RTS) // // Check whether any waiting threads need to be woken up. If the // run queue is empty, and there are no other tasks running, we // can wait indefinitely for something to happen. // - if ( !EMPTY_QUEUE(blocked_queue_hd) || !EMPTY_QUEUE(sleeping_queue) ) + if ( !emptyQueue(blocked_queue_hd) || !emptyQueue(sleeping_queue) ) { -#if defined(RTS_SUPPORTS_THREADS) - // We shouldn't be here... - barf("schedule: awaitEvent() in threaded RTS"); -#endif - awaitEvent( EMPTY_RUN_QUEUE() && !blackholes_need_checking ); + awaitEvent( emptyRunQueue(cap) && !blackholes_need_checking ); } +#endif } /* ---------------------------------------------------------------------------- * Check for threads blocked on BLACKHOLEs that can be woken up - * ASSUMES: sched_mutex * ------------------------------------------------------------------------- */ static void -scheduleCheckBlackHoles( void ) +scheduleCheckBlackHoles (Capability *cap) { - if ( blackholes_need_checking ) + if ( blackholes_need_checking ) // check without the lock first { - checkBlackHoles(); - blackholes_need_checking = rtsFalse; + ACQUIRE_LOCK(&sched_mutex); + if ( blackholes_need_checking ) { + checkBlackHoles(cap); + blackholes_need_checking = rtsFalse; + } + RELEASE_LOCK(&sched_mutex); } } /* ---------------------------------------------------------------------------- * Detect deadlock conditions and attempt to resolve them. - * ASSUMES: sched_mutex * ------------------------------------------------------------------------- */ static void -scheduleDetectDeadlock(void) +scheduleDetectDeadlock (Capability *cap, Task *task) { + +#if defined(PARALLEL_HASKELL) + // ToDo: add deadlock detection in GUM (similar to SMP) -- HWL + return; +#endif + /* * Detect deadlock: when we have no threads to run, there are no * threads blocked, waiting for I/O, or sleeping, and all the * other tasks are waiting for work, we must have a deadlock of * some description. */ - if ( EMPTY_THREAD_QUEUES() ) + if ( emptyThreadQueues(cap) ) { -#if !defined(PARALLEL_HASKELL) && !defined(RTS_SUPPORTS_THREADS) +#if defined(THREADED_RTS) + /* + * In the threaded RTS, we only check for deadlock if there + * has been no activity in a complete timeslice. This means + * we won't eagerly start a full GC just because we don't have + * any threads to run currently. + */ + if (recent_activity != ACTIVITY_INACTIVE) return; +#endif + IF_DEBUG(scheduler, sched_belch("deadlocked, forcing major GC...")); // Garbage collection can release some new threads due to @@ -871,10 +911,12 @@ scheduleDetectDeadlock(void) // they are unreachable and will therefore be sent an // exception. Any threads thus released will be immediately // runnable. - GarbageCollect(GetRoots,rtsTrue); - if ( !EMPTY_RUN_QUEUE() ) return; + scheduleDoGC( cap, task, rtsTrue/*force major GC*/ ); + recent_activity = ACTIVITY_DONE_GC; + + if ( !emptyRunQueue(cap) ) return; -#if defined(RTS_USER_SIGNALS) +#if defined(RTS_USER_SIGNALS) && (!defined(THREADED_RTS) || defined(mingw32_HOST_OS)) /* If we have user-installed signal handlers, then wait * for signals to arrive rather then bombing out with a * deadlock. @@ -886,39 +928,31 @@ scheduleDetectDeadlock(void) awaitUserSignals(); if (signals_pending()) { - RELEASE_LOCK(&sched_mutex); - startSignalHandlers(); - ACQUIRE_LOCK(&sched_mutex); + startSignalHandlers(cap); } // either we have threads to run, or we were interrupted: - ASSERT(!EMPTY_RUN_QUEUE() || interrupted); + ASSERT(!emptyRunQueue(cap) || interrupted); } #endif +#if !defined(THREADED_RTS) /* Probably a real deadlock. Send the current main thread the - * Deadlock exception (or in the SMP build, send *all* main - * threads the deadlock exception, since none of them can make - * progress). + * Deadlock exception. */ - { - StgMainThread *m; - m = main_threads; - switch (m->tso->why_blocked) { + if (task->tso) { + switch (task->tso->why_blocked) { + case BlockedOnSTM: case BlockedOnBlackHole: case BlockedOnException: case BlockedOnMVar: - raiseAsync(m->tso, (StgClosure *)NonTermination_closure); + raiseAsync(cap, task->tso, (StgClosure *)NonTermination_closure); return; default: barf("deadlock: main thread blocked in a strange way"); } } - -#elif defined(RTS_SUPPORTS_THREADS) - // ToDo: add deadlock detection in threaded RTS -#elif defined(PARALLEL_HASKELL) - // ToDo: add deadlock detection in GUM (similar to SMP) -- HWL + return; #endif } } @@ -1105,7 +1139,7 @@ static void scheduleActivateSpark(void) { #if defined(SPARKS) - ASSERT(EMPTY_RUN_QUEUE()); + ASSERT(emptyRunQueue()); /* We get here if the run queue is empty and want some work. We try to turn a spark into a thread, and add it to the run queue, from where it will be picked up in the next iteration of the scheduler @@ -1164,7 +1198,7 @@ scheduleActivateSpark(void) static rtsBool scheduleGetRemoteWork(rtsBool *receivedFinish) { - ASSERT(EMPTY_RUN_QUEUE()); + ASSERT(emptyRunQueue()); if (RtsFlags.ParFlags.BufferTime) { IF_PAR_DEBUG(verbose, @@ -1343,7 +1377,6 @@ JB: TODO: investigate wether state change field could be nuked /* ---------------------------------------------------------------------------- * After running a thread... - * ASSUMES: sched_mutex * ------------------------------------------------------------------------- */ static void @@ -1435,7 +1468,6 @@ schedulePostRunThread(void) /* ----------------------------------------------------------------------------- * Handle a thread that returned to the scheduler with ThreadHeepOverflow - * ASSUMES: sched_mutex * -------------------------------------------------------------------------- */ static rtsBool @@ -1453,12 +1485,15 @@ scheduleHandleHeapOverflow( Capability *cap, StgTSO *t ) debugBelch("--<< thread %ld (%s) stopped: requesting a large block (size %ld)\n", (long)t->id, whatNext_strs[t->what_next], blocks)); - // don't do this if it would push us over the - // alloc_blocks_lim limit; we'll GC first. - if (alloc_blocks + blocks < alloc_blocks_lim) { + // don't do this if the nursery is (nearly) full, we'll GC first. + if (cap->r.rCurrentNursery->link != NULL || + cap->r.rNursery->n_blocks == 1) { // paranoia to prevent infinite loop + // if the nursery has only one block. - alloc_blocks += blocks; + ACQUIRE_SM_LOCK bd = allocGroup( blocks ); + RELEASE_SM_LOCK + cap->r.rNursery->n_blocks += blocks; // link the new group into the list bd->link = cap->r.rCurrentNursery; @@ -1466,13 +1501,11 @@ scheduleHandleHeapOverflow( Capability *cap, StgTSO *t ) if (cap->r.rCurrentNursery->u.back != NULL) { cap->r.rCurrentNursery->u.back->link = bd; } else { -#ifdef SMP - cap->r.rNursery = g0s0->blocks = bd; -#else +#if !defined(SMP) ASSERT(g0s0->blocks == cap->r.rCurrentNursery && - g0s0->blocks == cap->r.rNursery); - cap->r.rNursery = g0s0->blocks = bd; + g0s0 == cap->r.rNursery); #endif + cap->r.rNursery->blocks = bd; } cap->r.rCurrentNursery->u.back = bd; @@ -1486,20 +1519,15 @@ scheduleHandleHeapOverflow( Capability *cap, StgTSO *t ) { bdescr *x; for (x = bd; x < bd + blocks; x++) { - x->step = g0s0; + x->step = cap->r.rNursery; x->gen_no = 0; x->flags = 0; } } -#if !defined(SMP) - // don't forget to update the block count in g0s0. - g0s0->n_blocks += blocks; - // This assert can be a killer if the app is doing lots // of large block allocations. - ASSERT(countBlocks(g0s0->blocks) == g0s0->n_blocks); -#endif + IF_DEBUG(sanity, checkNurserySanity(cap->r.rNursery)); // now update the nursery to point to the new block cap->r.rCurrentNursery = bd; @@ -1508,19 +1536,14 @@ scheduleHandleHeapOverflow( Capability *cap, StgTSO *t ) // run queue before us and steal the large block, but in that // case the thread will just end up requesting another large // block. - PUSH_ON_RUN_QUEUE(t); + pushOnRunQueue(cap,t); return rtsFalse; /* not actually GC'ing */ } } - /* make all the running tasks block on a condition variable, - * maybe set context_switch and wait till they all pile in, - * then have them wait on a GC condition variable. - */ IF_DEBUG(scheduler, debugBelch("--<< thread %ld (%s) stopped: HeapOverflow\n", (long)t->id, whatNext_strs[t->what_next])); - threadPaused(t); #if defined(GRAN) ASSERT(!is_on_queue(t,CurrentProc)); #elif defined(PARALLEL_HASKELL) @@ -1534,47 +1557,43 @@ scheduleHandleHeapOverflow( Capability *cap, StgTSO *t ) } #endif - PUSH_ON_RUN_QUEUE(t); + pushOnRunQueue(cap,t); return rtsTrue; /* actual GC is done at the end of the while loop in schedule() */ } /* ----------------------------------------------------------------------------- * Handle a thread that returned to the scheduler with ThreadStackOverflow - * ASSUMES: sched_mutex * -------------------------------------------------------------------------- */ static void -scheduleHandleStackOverflow( StgTSO *t) +scheduleHandleStackOverflow (Capability *cap, Task *task, StgTSO *t) { IF_DEBUG(scheduler,debugBelch("--<< thread %ld (%s) stopped, StackOverflow\n", (long)t->id, whatNext_strs[t->what_next])); /* just adjust the stack for this thread, then pop it back * on the run queue. */ - threadPaused(t); { /* enlarge the stack */ - StgTSO *new_t = threadStackOverflow(t); + StgTSO *new_t = threadStackOverflow(cap, t); - /* This TSO has moved, so update any pointers to it from the - * main thread stack. It better not be on any other queues... - * (it shouldn't be). + /* The TSO attached to this Task may have moved, so update the + * pointer to it. */ - if (t->main != NULL) { - t->main->tso = new_t; + if (task->tso == t) { + task->tso = new_t; } - PUSH_ON_RUN_QUEUE(new_t); + pushOnRunQueue(cap,new_t); } } /* ----------------------------------------------------------------------------- * Handle a thread that returned to the scheduler with ThreadYielding - * ASSUMES: sched_mutex * -------------------------------------------------------------------------- */ static rtsBool -scheduleHandleYield( StgTSO *t, nat prev_what_next ) +scheduleHandleYield( Capability *cap, StgTSO *t, nat prev_what_next ) { // Reset the context switch flag. We don't do this just before // running the thread, because that would mean we would lose ticks @@ -1611,8 +1630,6 @@ scheduleHandleYield( StgTSO *t, nat prev_what_next ) return rtsTrue; } - threadPaused(t); - #if defined(GRAN) ASSERT(!is_on_queue(t,CurrentProc)); @@ -1622,7 +1639,7 @@ scheduleHandleYield( StgTSO *t, nat prev_what_next ) #endif - addToRunQueue(t); + addToRunQueue(cap,t); #if defined(GRAN) /* add a ContinueThread event to actually process the thread */ @@ -1639,7 +1656,6 @@ scheduleHandleYield( StgTSO *t, nat prev_what_next ) /* ----------------------------------------------------------------------------- * Handle a thread that returned to the scheduler with ThreadBlocked - * ASSUMES: sched_mutex * -------------------------------------------------------------------------- */ static void @@ -1685,12 +1701,19 @@ scheduleHandleThreadBlocked( StgTSO *t emitSchedule = rtsTrue; #else /* !GRAN */ - /* don't need to do anything. Either the thread is blocked on - * I/O, in which case we'll have called addToBlockedQueue - * previously, or it's blocked on an MVar or Blackhole, in which - * case it'll be on the relevant queue already. - */ + + // We don't need to do anything. The thread is blocked, and it + // has tidied up its stack and placed itself on whatever queue + // it needs to be on. + +#if !defined(SMP) ASSERT(t->why_blocked != NotBlocked); + // This might not be true under SMP: we don't have + // exclusive access to this TSO, so someone might have + // woken it up by now. This actually happens: try + // conc023 +RTS -N2. +#endif + IF_DEBUG(scheduler, debugBelch("--<< thread %d (%s) stopped: ", t->id, whatNext_strs[t->what_next]); @@ -1706,14 +1729,10 @@ scheduleHandleThreadBlocked( StgTSO *t /* ----------------------------------------------------------------------------- * Handle a thread that returned to the scheduler with ThreadFinished - * ASSUMES: sched_mutex * -------------------------------------------------------------------------- */ static rtsBool -scheduleHandleThreadFinished( StgMainThread *mainThread - USED_WHEN_RTS_SUPPORTS_THREADS, - Capability *cap, - StgTSO *t ) +scheduleHandleThreadFinished (Capability *cap STG_UNUSED, Task *task, StgTSO *t) { /* Need to check whether this was a main thread, and if so, * return with the return value. @@ -1767,7 +1786,7 @@ scheduleHandleThreadFinished( StgMainThread *mainThread #endif // PARALLEL_HASKELL // - // Check whether the thread that just completed was a main + // Check whether the thread that just completed was a bound // thread, and if so return with the result. // // There is an assumption here that all thread completion goes @@ -1775,62 +1794,50 @@ scheduleHandleThreadFinished( StgMainThread *mainThread // ends up in the ThreadKilled state, that it stays on the run // queue so it can be dealt with here. // - if ( -#if defined(RTS_SUPPORTS_THREADS) - mainThread != NULL + + if (t->bound) { + + if (t->bound != task) { +#if !defined(THREADED_RTS) + // Must be a bound thread that is not the topmost one. Leave + // it on the run queue until the stack has unwound to the + // point where we can deal with this. Leaving it on the run + // queue also ensures that the garbage collector knows about + // this thread and its return value (it gets dropped from the + // all_threads list so there's no other way to find it). + appendToRunQueue(cap,t); + return rtsFalse; #else - mainThread->tso == t + // this cannot happen in the threaded RTS, because a + // bound thread can only be run by the appropriate Task. + barf("finished bound thread that isn't mine"); #endif - ) - { - // We are a bound thread: this must be our thread that just - // completed. - ASSERT(mainThread->tso == t); + } + + ASSERT(task->tso == t); if (t->what_next == ThreadComplete) { - if (mainThread->ret) { + if (task->ret) { // NOTE: return val is tso->sp[1] (see StgStartup.hc) - *(mainThread->ret) = (StgClosure *)mainThread->tso->sp[1]; + *(task->ret) = (StgClosure *)task->tso->sp[1]; } - mainThread->stat = Success; + task->stat = Success; } else { - if (mainThread->ret) { - *(mainThread->ret) = NULL; + if (task->ret) { + *(task->ret) = NULL; } if (interrupted) { - mainThread->stat = Interrupted; + task->stat = Interrupted; } else { - mainThread->stat = Killed; + task->stat = Killed; } } #ifdef DEBUG - removeThreadLabel((StgWord)mainThread->tso->id); + removeThreadLabel((StgWord)task->tso->id); #endif - if (mainThread->prev == NULL) { - main_threads = mainThread->link; - } else { - mainThread->prev->link = mainThread->link; - } - if (mainThread->link != NULL) { - mainThread->link->prev = NULL; - } - releaseCapability(cap); return rtsTrue; // tells schedule() to return } -#ifdef RTS_SUPPORTS_THREADS - ASSERT(t->main == NULL); -#else - if (t->main != NULL) { - // Must be a main thread that is not the topmost one. Leave - // it on the run queue until the stack has unwound to the - // point where we can deal with this. Leaving it on the run - // queue also ensures that the garbage collector knows about - // this thread and its return value (it gets dropped from the - // all_threads list so there's no other way to find it). - APPEND_TO_RUN_QUEUE(t); - } -#endif return rtsFalse; } @@ -1839,7 +1846,7 @@ scheduleHandleThreadFinished( StgMainThread *mainThread * -------------------------------------------------------------------------- */ static rtsBool -scheduleDoHeapProfile(void) +scheduleDoHeapProfile( rtsBool ready_to_gc STG_UNUSED ) { #if defined(PROFILING) // When we have +RTS -i0 and we're heap profiling, do a census at @@ -1858,17 +1865,16 @@ scheduleDoHeapProfile(void) /* ----------------------------------------------------------------------------- * Perform a garbage collection if necessary - * ASSUMES: sched_mutex * -------------------------------------------------------------------------- */ static void -scheduleDoGC( Capability *cap ) +scheduleDoGC( Capability *cap, Task *task USED_IF_SMP, rtsBool force_major ) { StgTSO *t; #ifdef SMP - int n_capabilities = RtsFlags.ParFlags.nNodes - 1; - // subtract one because we're already holding one. - Capability *caps[n_capabilities]; + static volatile StgWord waiting_for_gc; + rtsBool was_waiting; + nat i; #endif #ifdef SMP @@ -1883,57 +1889,91 @@ scheduleDoGC( Capability *cap ) // the other tasks to sleep and stay asleep. // - caps[n_capabilities] = cap; - while (n_capabilities > 0) { - IF_DEBUG(scheduler, sched_belch("ready_to_gc, grabbing all the capabilies (%d left)", n_capabilities)); - waitForReturnCapability(&sched_mutex, &cap); - n_capabilities--; - caps[n_capabilities] = cap; + was_waiting = cas(&waiting_for_gc, 0, 1); + if (was_waiting) { + do { + IF_DEBUG(scheduler, sched_belch("someone else is trying to GC...")); + yieldCapability(&cap,task); + } while (waiting_for_gc); + return; + } + + for (i=0; i < n_capabilities; i++) { + IF_DEBUG(scheduler, sched_belch("ready_to_gc, grabbing all the capabilies (%d/%d)", i, n_capabilities)); + if (cap != &capabilities[i]) { + Capability *pcap = &capabilities[i]; + // we better hope this task doesn't get migrated to + // another Capability while we're waiting for this one. + // It won't, because load balancing happens while we have + // all the Capabilities, but even so it's a slightly + // unsavoury invariant. + task->cap = pcap; + context_switch = 1; + waitForReturnCapability(&pcap, task); + if (pcap != &capabilities[i]) { + barf("scheduleDoGC: got the wrong capability"); + } + } } + + waiting_for_gc = rtsFalse; #endif /* Kick any transactions which are invalid back to their * atomically frames. When next scheduled they will try to * commit, this commit will fail and they will retry. */ - for (t = all_threads; t != END_TSO_QUEUE; t = t -> link) { - if (t -> what_next != ThreadRelocated && t -> trec != NO_TREC && t -> why_blocked == NotBlocked) { - if (!stmValidateTransaction (t -> trec)) { - IF_DEBUG(stm, sched_belch("trec %p found wasting its time", t)); - - // strip the stack back to the ATOMICALLY_FRAME, aborting - // the (nested) transaction, and saving the stack of any - // partially-evaluated thunks on the heap. - raiseAsync_(t, NULL, rtsTrue); - + { + StgTSO *next; + + for (t = all_threads; t != END_TSO_QUEUE; t = next) { + if (t->what_next == ThreadRelocated) { + next = t->link; + } else { + next = t->global_link; + if (t -> trec != NO_TREC && t -> why_blocked == NotBlocked) { + if (!stmValidateNestOfTransactions (t -> trec)) { + IF_DEBUG(stm, sched_belch("trec %p found wasting its time", t)); + + // strip the stack back to the + // ATOMICALLY_FRAME, aborting the (nested) + // transaction, and saving the stack of any + // partially-evaluated thunks on the heap. + raiseAsync_(cap, t, NULL, rtsTrue, NULL); + #ifdef REG_R1 - ASSERT(get_itbl((StgClosure *)t->sp)->type == ATOMICALLY_FRAME); + ASSERT(get_itbl((StgClosure *)t->sp)->type == ATOMICALLY_FRAME); #endif + } + } } } } // so this happens periodically: - scheduleCheckBlackHoles(); + scheduleCheckBlackHoles(cap); + IF_DEBUG(scheduler, printAllThreads()); + /* everybody back, start the GC. * Could do it in this thread, or signal a condition var * to do it in another thread. Either way, we need to * broadcast on gc_pending_cond afterward. */ -#if defined(RTS_SUPPORTS_THREADS) +#if defined(THREADED_RTS) IF_DEBUG(scheduler,sched_belch("doing GC")); #endif - GarbageCollect(GetRoots,rtsFalse); + GarbageCollect(GetRoots, force_major); #if defined(SMP) - { - // release our stash of capabilities. - nat i; - for (i = 0; i < RtsFlags.ParFlags.nNodes-1; i++) { - releaseCapability(caps[i]); + // release our stash of capabilities. + for (i = 0; i < n_capabilities; i++) { + if (cap != &capabilities[i]) { + task->cap = &capabilities[i]; + releaseCapability(&capabilities[i]); } } + task->cap = cap; #endif #if defined(GRAN) @@ -1956,7 +1996,7 @@ scheduleDoGC( Capability *cap ) StgBool rtsSupportsBoundThreads(void) { -#ifdef THREADED_RTS +#if defined(THREADED_RTS) return rtsTrue; #else return rtsFalse; @@ -1968,10 +2008,10 @@ rtsSupportsBoundThreads(void) * ------------------------------------------------------------------------- */ StgBool -isThreadBound(StgTSO* tso USED_IN_THREADED_RTS) +isThreadBound(StgTSO* tso USED_IF_THREADS) { -#ifdef THREADED_RTS - return (tso->main != NULL); +#if defined(THREADED_RTS) + return (tso->bound != NULL); #endif return rtsFalse; } @@ -1980,13 +2020,13 @@ isThreadBound(StgTSO* tso USED_IN_THREADED_RTS) * Singleton fork(). Do not copy any running threads. * ------------------------------------------------------------------------- */ -#ifndef mingw32_HOST_OS +#if !defined(mingw32_HOST_OS) && !defined(SMP) #define FORKPROCESS_PRIMOP_SUPPORTED #endif #ifdef FORKPROCESS_PRIMOP_SUPPORTED static void -deleteThreadImmediately(StgTSO *tso); +deleteThreadImmediately(Capability *cap, StgTSO *tso); #endif StgInt forkProcess(HsStablePtr *entry @@ -1996,92 +2036,116 @@ forkProcess(HsStablePtr *entry ) { #ifdef FORKPROCESS_PRIMOP_SUPPORTED - pid_t pid; - StgTSO* t,*next; - StgMainThread *m; - SchedulerStatus rc; - - IF_DEBUG(scheduler,sched_belch("forking!")); - rts_lock(); // This not only acquires sched_mutex, it also - // makes sure that no other threads are running - - pid = fork(); - - if (pid) { /* parent */ - - /* just return the pid */ - rts_unlock(); - return pid; + Task *task; + pid_t pid; + StgTSO* t,*next; + Capability *cap; - } else { /* child */ + IF_DEBUG(scheduler,sched_belch("forking!")); + // ToDo: for SMP, we should probably acquire *all* the capabilities + cap = rts_lock(); - // delete all threads - run_queue_hd = run_queue_tl = END_TSO_QUEUE; + pid = fork(); - for (t = all_threads; t != END_TSO_QUEUE; t = next) { - next = t->link; - - // don't allow threads to catch the ThreadKilled exception - deleteThreadImmediately(t); - } - - // wipe the main thread list - while((m = main_threads) != NULL) { - main_threads = m->link; -# ifdef THREADED_RTS - closeCondition(&m->bound_thread_cond); -# endif - stgFree(m); + if (pid) { // parent + + // just return the pid + rts_unlock(cap); + return pid; + + } else { // child + + // delete all threads + cap->run_queue_hd = END_TSO_QUEUE; + cap->run_queue_tl = END_TSO_QUEUE; + + for (t = all_threads; t != END_TSO_QUEUE; t = next) { + next = t->link; + + // don't allow threads to catch the ThreadKilled exception + deleteThreadImmediately(cap,t); + } + + // wipe the task list + ACQUIRE_LOCK(&sched_mutex); + for (task = all_tasks; task != NULL; task=task->all_link) { + if (task != cap->running_task) discardTask(task); + } + RELEASE_LOCK(&sched_mutex); + + cap->suspended_ccalling_tasks = NULL; + +#if defined(THREADED_RTS) + // wipe our spare workers list. + cap->spare_workers = NULL; + cap->returning_tasks_hd = NULL; + cap->returning_tasks_tl = NULL; +#endif + + cap = rts_evalStableIO(cap, entry, NULL); // run the action + rts_checkSchedStatus("forkProcess",cap); + + rts_unlock(cap); + hs_exit(); // clean up and exit + stg_exit(EXIT_SUCCESS); } - - rc = rts_evalStableIO(entry, NULL); // run the action - rts_checkSchedStatus("forkProcess",rc); - - rts_unlock(); - - hs_exit(); // clean up and exit - stg_exit(0); - } #else /* !FORKPROCESS_PRIMOP_SUPPORTED */ - barf("forkProcess#: primop not supported, sorry!\n"); - return -1; + barf("forkProcess#: primop not supported on this platform, sorry!\n"); + return -1; #endif } /* --------------------------------------------------------------------------- - * deleteAllThreads(): kill all the live threads. - * - * This is used when we catch a user interrupt (^C), before performing - * any necessary cleanups and running finalizers. - * - * Locks: sched_mutex held. + * Delete the threads on the run queue of the current capability. * ------------------------------------------------------------------------- */ -void -deleteAllThreads ( void ) +static void +deleteRunQueue (Capability *cap) { - StgTSO* t, *next; - IF_DEBUG(scheduler,sched_belch("deleting all threads")); - for (t = all_threads; t != END_TSO_QUEUE; t = next) { - next = t->global_link; - deleteThread(t); - } - - // 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(blackhole_queue == END_TSO_QUEUE); - ASSERT(sleeping_queue == END_TSO_QUEUE); + StgTSO *t, *next; + for (t = cap->run_queue_hd; t != END_TSO_QUEUE; t = next) { + ASSERT(t->what_next != ThreadRelocated); + next = t->link; + deleteThread(cap, t); + } } /* startThread and insertThread are now in GranSim.c -- HWL */ +/* ----------------------------------------------------------------------------- + Managing the suspended_ccalling_tasks list. + Locks required: sched_mutex + -------------------------------------------------------------------------- */ + +STATIC_INLINE void +suspendTask (Capability *cap, Task *task) +{ + ASSERT(task->next == NULL && task->prev == NULL); + task->next = cap->suspended_ccalling_tasks; + task->prev = NULL; + if (cap->suspended_ccalling_tasks) { + cap->suspended_ccalling_tasks->prev = task; + } + cap->suspended_ccalling_tasks = task; +} + +STATIC_INLINE void +recoverSuspendedTask (Capability *cap, Task *task) +{ + if (task->prev) { + task->prev->next = task->next; + } else { + ASSERT(cap->suspended_ccalling_tasks == task); + cap->suspended_ccalling_tasks = task->next; + } + if (task->next) { + task->next->prev = task->prev; + } + task->next = task->prev = NULL; +} + /* --------------------------------------------------------------------------- * Suspending & resuming Haskell threads. * @@ -2097,102 +2161,94 @@ deleteAllThreads ( void ) * on return from the C function. * ------------------------------------------------------------------------- */ -StgInt -suspendThread( StgRegTable *reg ) +void * +suspendThread (StgRegTable *reg) { - nat tok; Capability *cap; int saved_errno = errno; + StgTSO *tso; + Task *task; - /* assume that *reg is a pointer to the StgRegTable part - * of a Capability. + /* assume that *reg is a pointer to the StgRegTable part of a Capability. */ - cap = (Capability *)((void *)((unsigned char*)reg - sizeof(StgFunTable))); + cap = regTableToCapability(reg); - ACQUIRE_LOCK(&sched_mutex); + task = cap->running_task; + tso = cap->r.rCurrentTSO; IF_DEBUG(scheduler, - sched_belch("thread %d did a _ccall_gc", cap->r.rCurrentTSO->id)); + sched_belch("thread %d did a safe foreign call", cap->r.rCurrentTSO->id)); // XXX this might not be necessary --SDM - cap->r.rCurrentTSO->what_next = ThreadRunGHC; + tso->what_next = ThreadRunGHC; - threadPaused(cap->r.rCurrentTSO); - cap->r.rCurrentTSO->link = suspended_ccalling_threads; - suspended_ccalling_threads = cap->r.rCurrentTSO; + threadPaused(cap,tso); - if(cap->r.rCurrentTSO->blocked_exceptions == NULL) { - cap->r.rCurrentTSO->why_blocked = BlockedOnCCall; - cap->r.rCurrentTSO->blocked_exceptions = END_TSO_QUEUE; + if(tso->blocked_exceptions == NULL) { + tso->why_blocked = BlockedOnCCall; + tso->blocked_exceptions = END_TSO_QUEUE; } else { - cap->r.rCurrentTSO->why_blocked = BlockedOnCCall_NoUnblockExc; + tso->why_blocked = BlockedOnCCall_NoUnblockExc; } - /* Use the thread ID as the token; it should be unique */ - tok = cap->r.rCurrentTSO->id; + // Hand back capability + task->suspended_tso = tso; - /* Hand back capability */ - releaseCapability(cap); + ACQUIRE_LOCK(&cap->lock); + + suspendTask(cap,task); + cap->in_haskell = rtsFalse; + releaseCapability_(cap); -#if defined(RTS_SUPPORTS_THREADS) + RELEASE_LOCK(&cap->lock); + +#if defined(THREADED_RTS) /* Preparing to leave the RTS, so ensure there's a native thread/task waiting to take over. */ - IF_DEBUG(scheduler, sched_belch("worker (token %d): leaving RTS", tok)); + IF_DEBUG(scheduler, sched_belch("thread %d: leaving RTS", tso->id)); #endif - in_haskell = rtsFalse; - RELEASE_LOCK(&sched_mutex); - errno = saved_errno; - return tok; + return task; } StgRegTable * -resumeThread( StgInt tok ) +resumeThread (void *task_) { - StgTSO *tso, **prev; - Capability *cap; - int saved_errno = errno; - -#if defined(RTS_SUPPORTS_THREADS) - /* Wait for permission to re-enter the RTS with the result. */ - ACQUIRE_LOCK(&sched_mutex); - waitForReturnCapability(&sched_mutex, &cap); - - IF_DEBUG(scheduler, sched_belch("worker (token %d): re-entering RTS", tok)); -#else - grabCapability(&cap); -#endif - - /* Remove the thread off of the suspended list */ - prev = &suspended_ccalling_threads; - for (tso = suspended_ccalling_threads; - tso != END_TSO_QUEUE; - prev = &tso->link, tso = tso->link) { - if (tso->id == (StgThreadID)tok) { - *prev = tso->link; - break; + StgTSO *tso; + Capability *cap; + int saved_errno = errno; + Task *task = task_; + + cap = task->cap; + // Wait for permission to re-enter the RTS with the result. + waitForReturnCapability(&cap,task); + // we might be on a different capability now... but if so, our + // entry on the suspended_ccalling_tasks list will also have been + // migrated. + + // Remove the thread from the suspended list + recoverSuspendedTask(cap,task); + + tso = task->suspended_tso; + task->suspended_tso = NULL; + tso->link = END_TSO_QUEUE; + IF_DEBUG(scheduler, sched_belch("thread %d: re-entering RTS", tso->id)); + + if (tso->why_blocked == BlockedOnCCall) { + awakenBlockedQueue(cap,tso->blocked_exceptions); + tso->blocked_exceptions = NULL; } - } - if (tso == END_TSO_QUEUE) { - barf("resumeThread: thread not found"); - } - tso->link = END_TSO_QUEUE; - - if(tso->why_blocked == BlockedOnCCall) { - awakenBlockedQueueNoLock(tso->blocked_exceptions); - tso->blocked_exceptions = NULL; - } - - /* Reset blocking status */ - tso->why_blocked = NotBlocked; + + /* Reset blocking status */ + tso->why_blocked = NotBlocked; + + cap->r.rCurrentTSO = tso; + cap->in_haskell = rtsTrue; + errno = saved_errno; - cap->r.rCurrentTSO = tso; - in_haskell = rtsTrue; - RELEASE_LOCK(&sched_mutex); - errno = saved_errno; - return &cap->r; + return &cap->r; } /* --------------------------------------------------------------------------- @@ -2259,171 +2315,174 @@ StgTSO * createThread(nat size, StgInt pri) #else StgTSO * -createThread(nat size) +createThread(Capability *cap, nat size) #endif { - StgTSO *tso; nat stack_size; + /* sched_mutex is *not* required */ + /* First check whether we should create a thread at all */ #if defined(PARALLEL_HASKELL) - /* check that no more than RtsFlags.ParFlags.maxThreads threads are created */ - if (advisory_thread_count >= RtsFlags.ParFlags.maxThreads) { - threadsIgnored++; - debugBelch("{createThread}Daq ghuH: refusing to create another thread; no more than %d threads allowed (currently %d)\n", - RtsFlags.ParFlags.maxThreads, advisory_thread_count); - return END_TSO_QUEUE; - } - threadsCreated++; + /* check that no more than RtsFlags.ParFlags.maxThreads threads are created */ + if (advisory_thread_count >= RtsFlags.ParFlags.maxThreads) { + threadsIgnored++; + debugBelch("{createThread}Daq ghuH: refusing to create another thread; no more than %d threads allowed (currently %d)\n", + RtsFlags.ParFlags.maxThreads, advisory_thread_count); + return END_TSO_QUEUE; + } + threadsCreated++; #endif #if defined(GRAN) - ASSERT(!RtsFlags.GranFlags.Light || CurrentProc==0); + ASSERT(!RtsFlags.GranFlags.Light || CurrentProc==0); #endif - // ToDo: check whether size = stack_size - TSO_STRUCT_SIZEW - - /* catch ridiculously small stack sizes */ - if (size < MIN_STACK_WORDS + TSO_STRUCT_SIZEW) { - size = MIN_STACK_WORDS + TSO_STRUCT_SIZEW; - } + // ToDo: check whether size = stack_size - TSO_STRUCT_SIZEW - stack_size = size - TSO_STRUCT_SIZEW; + /* catch ridiculously small stack sizes */ + if (size < MIN_STACK_WORDS + TSO_STRUCT_SIZEW) { + size = MIN_STACK_WORDS + TSO_STRUCT_SIZEW; + } - tso = (StgTSO *)allocate(size); - TICK_ALLOC_TSO(stack_size, 0); + stack_size = size - TSO_STRUCT_SIZEW; + + tso = (StgTSO *)allocateLocal(cap, size); + TICK_ALLOC_TSO(stack_size, 0); - SET_HDR(tso, &stg_TSO_info, CCS_SYSTEM); + SET_HDR(tso, &stg_TSO_info, CCS_SYSTEM); #if defined(GRAN) - SET_GRAN_HDR(tso, ThisPE); + SET_GRAN_HDR(tso, ThisPE); #endif - // Always start with the compiled code evaluator - tso->what_next = ThreadRunGHC; - - tso->id = next_thread_id++; - tso->why_blocked = NotBlocked; - tso->blocked_exceptions = NULL; - - tso->saved_errno = 0; - tso->main = NULL; - - tso->stack_size = stack_size; - tso->max_stack_size = round_to_mblocks(RtsFlags.GcFlags.maxStkSize) - - TSO_STRUCT_SIZEW; - tso->sp = (P_)&(tso->stack) + stack_size; + // Always start with the compiled code evaluator + tso->what_next = ThreadRunGHC; - tso->trec = NO_TREC; + tso->why_blocked = NotBlocked; + tso->blocked_exceptions = NULL; + + tso->saved_errno = 0; + tso->bound = NULL; + + tso->stack_size = stack_size; + tso->max_stack_size = round_to_mblocks(RtsFlags.GcFlags.maxStkSize) + - TSO_STRUCT_SIZEW; + tso->sp = (P_)&(tso->stack) + stack_size; + tso->trec = NO_TREC; + #ifdef PROFILING - tso->prof.CCCS = CCS_MAIN; + tso->prof.CCCS = CCS_MAIN; #endif - + /* 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; - + 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) - /* uses more flexible routine in GranSim */ - insertThread(tso, CurrentProc); + /* uses more flexible routine in GranSim */ + insertThread(tso, CurrentProc); #else - /* In a non-GranSim setup the pushing of a TSO onto the runq is separated - * from its creation - */ + /* In a non-GranSim setup the pushing of a TSO onto the runq is separated + * from its creation + */ #endif - + #if defined(GRAN) - if (RtsFlags.GranFlags.GranSimStats.Full) - DumpGranEvent(GR_START,tso); + if (RtsFlags.GranFlags.GranSimStats.Full) + DumpGranEvent(GR_START,tso); #elif defined(PARALLEL_HASKELL) - if (RtsFlags.ParFlags.ParStats.Full) - DumpGranEvent(GR_STARTQ,tso); - /* HACk to avoid SCHEDULE - LastTSO = tso; */ + if (RtsFlags.ParFlags.ParStats.Full) + DumpGranEvent(GR_STARTQ,tso); + /* HACk to avoid SCHEDULE + LastTSO = tso; */ #endif - - /* Link the new thread on the global thread list. - */ - tso->global_link = all_threads; - all_threads = tso; - + + /* Link the new thread on the global thread list. + */ + ACQUIRE_LOCK(&sched_mutex); + tso->id = next_thread_id++; // while we have the mutex + tso->global_link = all_threads; + all_threads = tso; + RELEASE_LOCK(&sched_mutex); + #if defined(DIST) - tso->dist.priority = MandatoryPriority; //by default that is... + tso->dist.priority = MandatoryPriority; //by default that is... #endif - + #if defined(GRAN) - tso->gran.pri = pri; + tso->gran.pri = pri; # if defined(DEBUG) - tso->gran.magic = TSO_MAGIC; // debugging only + tso->gran.magic = TSO_MAGIC; // debugging only # endif - tso->gran.sparkname = 0; - tso->gran.startedat = CURRENT_TIME; - tso->gran.exported = 0; - tso->gran.basicblocks = 0; - tso->gran.allocs = 0; - tso->gran.exectime = 0; - tso->gran.fetchtime = 0; - tso->gran.fetchcount = 0; - tso->gran.blocktime = 0; - tso->gran.blockcount = 0; - tso->gran.blockedat = 0; - tso->gran.globalsparks = 0; - tso->gran.localsparks = 0; - if (RtsFlags.GranFlags.Light) - tso->gran.clock = Now; /* local clock */ - else - tso->gran.clock = 0; - - IF_DEBUG(gran,printTSO(tso)); + tso->gran.sparkname = 0; + tso->gran.startedat = CURRENT_TIME; + tso->gran.exported = 0; + tso->gran.basicblocks = 0; + tso->gran.allocs = 0; + tso->gran.exectime = 0; + tso->gran.fetchtime = 0; + tso->gran.fetchcount = 0; + tso->gran.blocktime = 0; + tso->gran.blockcount = 0; + tso->gran.blockedat = 0; + tso->gran.globalsparks = 0; + tso->gran.localsparks = 0; + if (RtsFlags.GranFlags.Light) + tso->gran.clock = Now; /* local clock */ + else + tso->gran.clock = 0; + + IF_DEBUG(gran,printTSO(tso)); #elif defined(PARALLEL_HASKELL) # if defined(DEBUG) - tso->par.magic = TSO_MAGIC; // debugging only + tso->par.magic = TSO_MAGIC; // debugging only # endif - tso->par.sparkname = 0; - tso->par.startedat = CURRENT_TIME; - tso->par.exported = 0; - tso->par.basicblocks = 0; - tso->par.allocs = 0; - tso->par.exectime = 0; - tso->par.fetchtime = 0; - tso->par.fetchcount = 0; - tso->par.blocktime = 0; - tso->par.blockcount = 0; - tso->par.blockedat = 0; - tso->par.globalsparks = 0; - tso->par.localsparks = 0; + tso->par.sparkname = 0; + tso->par.startedat = CURRENT_TIME; + tso->par.exported = 0; + tso->par.basicblocks = 0; + tso->par.allocs = 0; + tso->par.exectime = 0; + tso->par.fetchtime = 0; + tso->par.fetchcount = 0; + tso->par.blocktime = 0; + tso->par.blockcount = 0; + tso->par.blockedat = 0; + tso->par.globalsparks = 0; + tso->par.localsparks = 0; #endif - + #if defined(GRAN) - globalGranStats.tot_threads_created++; - globalGranStats.threads_created_on_PE[CurrentProc]++; - globalGranStats.tot_sq_len += spark_queue_len(CurrentProc); - globalGranStats.tot_sq_probes++; + globalGranStats.tot_threads_created++; + globalGranStats.threads_created_on_PE[CurrentProc]++; + globalGranStats.tot_sq_len += spark_queue_len(CurrentProc); + globalGranStats.tot_sq_probes++; #elif defined(PARALLEL_HASKELL) - // collect parallel global statistics (currently done together with GC stats) - if (RtsFlags.ParFlags.ParStats.Global && - RtsFlags.GcFlags.giveStats > NO_GC_STATS) { - //debugBelch("Creating thread %d @ %11.2f\n", tso->id, usertime()); - globalParStats.tot_threads_created++; - } + // collect parallel global statistics (currently done together with GC stats) + if (RtsFlags.ParFlags.ParStats.Global && + RtsFlags.GcFlags.giveStats > NO_GC_STATS) { + //debugBelch("Creating thread %d @ %11.2f\n", tso->id, usertime()); + globalParStats.tot_threads_created++; + } #endif - + #if defined(GRAN) - IF_GRAN_DEBUG(pri, - sched_belch("==__ schedule: Created TSO %d (%p);", - CurrentProc, tso, tso->id)); + IF_GRAN_DEBUG(pri, + sched_belch("==__ schedule: Created TSO %d (%p);", + CurrentProc, tso, tso->id)); #elif defined(PARALLEL_HASKELL) - IF_PAR_DEBUG(verbose, - sched_belch("==__ schedule: Created TSO %d (%p); %d threads active", - (long)tso->id, tso, advisory_thread_count)); + IF_PAR_DEBUG(verbose, + sched_belch("==__ schedule: Created TSO %d (%p); %d threads active", + (long)tso->id, tso, advisory_thread_count)); #else - IF_DEBUG(scheduler,sched_belch("created thread %ld, stack size = %lx words", - (long)tso->id, (long)tso->stack_size)); + IF_DEBUG(scheduler,sched_belch("created thread %ld, stack size = %lx words", + (long)tso->id, (long)tso->stack_size)); #endif - return tso; + return tso; } #if defined(PAR) @@ -2486,85 +2545,83 @@ activateSpark (rtsSpark spark) /* --------------------------------------------------------------------------- * scheduleThread() * - * scheduleThread puts a thread on the head of the runnable queue. + * scheduleThread puts a thread on the end of the runnable queue. * This will usually be done immediately after a thread is created. * The caller of scheduleThread must create the thread using e.g. * createThread and push an appropriate closure * on this thread's stack before the scheduler is invoked. * ------------------------------------------------------------------------ */ -static void -scheduleThread_(StgTSO *tso) +void +scheduleThread(Capability *cap, StgTSO *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); - threadRunnable(); + // The thread goes at the *end* of the run-queue, to avoid possible + // starvation of any threads already on the queue. + appendToRunQueue(cap,tso); } -void -scheduleThread(StgTSO* tso) +Capability * +scheduleWaitThread (StgTSO* tso, /*[out]*/HaskellObj* ret, Capability *cap) { - ACQUIRE_LOCK(&sched_mutex); - scheduleThread_(tso); - RELEASE_LOCK(&sched_mutex); -} + Task *task; -#if defined(RTS_SUPPORTS_THREADS) -static Condition bound_cond_cache; -static int bound_cond_cache_full = 0; + // We already created/initialised the Task + task = cap->running_task; + + // This TSO is now a bound thread; make the Task and TSO + // point to each other. + tso->bound = task; + + task->tso = tso; + task->ret = ret; + task->stat = NoStatus; + + appendToRunQueue(cap,tso); + + IF_DEBUG(scheduler, sched_belch("new bound thread (%d)", tso->id)); + +#if defined(GRAN) + /* GranSim specific init */ + CurrentTSO = m->tso; // the TSO to run + procStatus[MainProc] = Busy; // status of main PE + CurrentProc = MainProc; // PE to run it on #endif + cap = schedule(cap,task); + + ASSERT(task->stat != NoStatus); + ASSERT_FULL_CAPABILITY_INVARIANTS(cap,task); + + IF_DEBUG(scheduler, sched_belch("bound thread (%d) finished", task->tso->id)); + return cap; +} + +/* ---------------------------------------------------------------------------- + * Starting Tasks + * ------------------------------------------------------------------------- */ -SchedulerStatus -scheduleWaitThread(StgTSO* tso, /*[out]*/HaskellObj* ret, - Capability *initialCapability) +#if defined(THREADED_RTS) +void +workerStart(Task *task) { - // Precondition: sched_mutex must be held - StgMainThread *m; - - m = stgMallocBytes(sizeof(StgMainThread), "waitThread"); - m->tso = tso; - tso->main = m; - m->ret = ret; - m->stat = NoStatus; - m->link = main_threads; - m->prev = NULL; - if (main_threads != NULL) { - main_threads->prev = m; - } - main_threads = m; - -#if defined(RTS_SUPPORTS_THREADS) - // Allocating a new condition for each thread is expensive, so we - // cache one. This is a pretty feeble hack, but it helps speed up - // consecutive call-ins quite a bit. - if (bound_cond_cache_full) { - m->bound_thread_cond = bound_cond_cache; - bound_cond_cache_full = 0; - } else { - initCondition(&m->bound_thread_cond); - } -#endif + Capability *cap; - /* Put the thread on the main-threads list prior to scheduling the TSO. - Failure to do so introduces a race condition in the MT case (as - identified by Wolfgang Thaller), whereby the new task/OS thread - created by scheduleThread_() would complete prior to the thread - that spawned it managed to put 'itself' on the main-threads list. - The upshot of it all being that the worker thread wouldn't get to - signal the completion of the its work item for the main thread to - see (==> it got stuck waiting.) -- sof 6/02. - */ - IF_DEBUG(scheduler, sched_belch("waiting for thread (%d)", tso->id)); - - APPEND_TO_RUN_QUEUE(tso); - // NB. Don't call threadRunnable() here, because the thread is - // bound and only runnable by *this* OS thread, so waking up other - // workers will just slow things down. + // See startWorkerTask(). + ACQUIRE_LOCK(&task->lock); + cap = task->cap; + RELEASE_LOCK(&task->lock); - return waitThread_(m, initialCapability); + // set the thread-local pointer to the Task: + taskEnter(task); + + // schedule() runs without a lock. + cap = schedule(cap,task); + + // On exit from schedule(), we have a Capability. + releaseCapability(cap); + taskStop(task); } +#endif /* --------------------------------------------------------------------------- * initScheduler() @@ -2580,7 +2637,6 @@ initScheduler(void) { #if defined(GRAN) nat i; - for (i=0; i<=MAX_PROC; i++) { run_queue_hds[i] = END_TSO_QUEUE; run_queue_tls[i] = END_TSO_QUEUE; @@ -2590,19 +2646,14 @@ initScheduler(void) blackhole_queue[i] = END_TSO_QUEUE; sleeping_queue = END_TSO_QUEUE; } -#else - run_queue_hd = END_TSO_QUEUE; - run_queue_tl = END_TSO_QUEUE; +#elif !defined(THREADED_RTS) blocked_queue_hd = END_TSO_QUEUE; blocked_queue_tl = END_TSO_QUEUE; - blackhole_queue = END_TSO_QUEUE; sleeping_queue = END_TSO_QUEUE; -#endif - - suspended_ccalling_threads = END_TSO_QUEUE; +#endif - main_threads = NULL; - all_threads = END_TSO_QUEUE; + blackhole_queue = END_TSO_QUEUE; + all_threads = END_TSO_QUEUE; context_switch = 0; interrupted = 0; @@ -2610,11 +2661,10 @@ initScheduler(void) RtsFlags.ConcFlags.ctxtSwitchTicks = RtsFlags.ConcFlags.ctxtSwitchTime / TICK_MILLISECS; -#if defined(RTS_SUPPORTS_THREADS) +#if defined(THREADED_RTS) /* Initialise the mutex and condition variables used by * the scheduler. */ initMutex(&sched_mutex); - initMutex(&term_mutex); #endif ACQUIRE_LOCK(&sched_mutex); @@ -2624,18 +2674,30 @@ initScheduler(void) * floating around (only SMP builds have more than one). */ initCapabilities(); - -#if defined(RTS_SUPPORTS_THREADS) + initTaskManager(); -#endif -#if defined(SMP) - /* eagerly start some extra workers */ - startTasks(RtsFlags.ParFlags.nNodes, taskStart); +#if defined(SMP) || defined(PARALLEL_HASKELL) + initSparkPools(); #endif -#if /* defined(SMP) ||*/ defined(PARALLEL_HASKELL) - initSparkPools(); +#if defined(SMP) + /* + * Eagerly start one worker to run each Capability, except for + * Capability 0. The idea is that we're probably going to start a + * bound thread on Capability 0 pretty soon, so we don't want a + * worker task hogging it. + */ + { + nat i; + Capability *cap; + for (i = 1; i < n_capabilities; i++) { + cap = &capabilities[i]; + ACQUIRE_LOCK(&cap->lock); + startWorkerTask(cap, workerStart); + RELEASE_LOCK(&cap->lock); + } + } #endif RELEASE_LOCK(&sched_mutex); @@ -2646,57 +2708,23 @@ exitScheduler( void ) { interrupted = rtsTrue; shutting_down_scheduler = rtsTrue; -#if defined(RTS_SUPPORTS_THREADS) - if (threadIsTask(osThreadId())) { taskStop(); } - stopTaskManager(); -#endif -} - -/* ---------------------------------------------------------------------------- - Managing the per-task allocation areas. - - Each capability comes with an allocation area. These are - fixed-length block lists into which allocation can be done. - - ToDo: no support for two-space collection at the moment??? - ------------------------------------------------------------------------- */ -static SchedulerStatus -waitThread_(StgMainThread* m, Capability *initialCapability) -{ - SchedulerStatus stat; - - // Precondition: sched_mutex must be held. - IF_DEBUG(scheduler, sched_belch("new main thread (%d)", m->tso->id)); - -#if defined(GRAN) - /* GranSim specific init */ - CurrentTSO = m->tso; // the TSO to run - procStatus[MainProc] = Busy; // status of main PE - CurrentProc = MainProc; // PE to run it on - schedule(m,initialCapability); -#else - schedule(m,initialCapability); - ASSERT(m->stat != NoStatus); -#endif - - stat = m->stat; +#if defined(THREADED_RTS) + { + Task *task; + nat i; + + ACQUIRE_LOCK(&sched_mutex); + task = newBoundTask(); + RELEASE_LOCK(&sched_mutex); -#if defined(RTS_SUPPORTS_THREADS) - // Free the condition variable, returning it to the cache if possible. - if (!bound_cond_cache_full) { - bound_cond_cache = m->bound_thread_cond; - bound_cond_cache_full = 1; - } else { - closeCondition(&m->bound_thread_cond); - } + for (i = 0; i < n_capabilities; i++) { + shutdownCapability(&capabilities[i], task); + } + boundTaskExiting(task); + stopTaskManager(); + } #endif - - IF_DEBUG(scheduler, sched_belch("main thread (%d) finished", m->tso->id)); - stgFree(m); - - // Postcondition: sched_mutex still held - return stat; } /* --------------------------------------------------------------------------- @@ -2718,59 +2746,56 @@ waitThread_(StgMainThread* m, Capability *initialCapability) void GetRoots( evac_fn evac ) { -#if defined(GRAN) - { nat i; + Capability *cap; + Task *task; + +#if defined(GRAN) for (i=0; i<=RtsFlags.GranFlags.proc; i++) { - if ((run_queue_hds[i] != END_TSO_QUEUE) && ((run_queue_hds[i] != NULL))) - evac((StgClosure **)&run_queue_hds[i]); - if ((run_queue_tls[i] != END_TSO_QUEUE) && ((run_queue_tls[i] != NULL))) - evac((StgClosure **)&run_queue_tls[i]); - - if ((blocked_queue_hds[i] != END_TSO_QUEUE) && ((blocked_queue_hds[i] != NULL))) - evac((StgClosure **)&blocked_queue_hds[i]); - if ((blocked_queue_tls[i] != END_TSO_QUEUE) && ((blocked_queue_tls[i] != NULL))) - evac((StgClosure **)&blocked_queue_tls[i]); - if ((ccalling_threadss[i] != END_TSO_QUEUE) && ((ccalling_threadss[i] != NULL))) - evac((StgClosure **)&ccalling_threads[i]); + if ((run_queue_hds[i] != END_TSO_QUEUE) && ((run_queue_hds[i] != NULL))) + evac((StgClosure **)&run_queue_hds[i]); + if ((run_queue_tls[i] != END_TSO_QUEUE) && ((run_queue_tls[i] != NULL))) + evac((StgClosure **)&run_queue_tls[i]); + + if ((blocked_queue_hds[i] != END_TSO_QUEUE) && ((blocked_queue_hds[i] != NULL))) + evac((StgClosure **)&blocked_queue_hds[i]); + if ((blocked_queue_tls[i] != END_TSO_QUEUE) && ((blocked_queue_tls[i] != NULL))) + evac((StgClosure **)&blocked_queue_tls[i]); + if ((ccalling_threadss[i] != END_TSO_QUEUE) && ((ccalling_threadss[i] != NULL))) + evac((StgClosure **)&ccalling_threads[i]); } - } - markEventQueue(); + markEventQueue(); #else /* !GRAN */ - if (run_queue_hd != END_TSO_QUEUE) { - ASSERT(run_queue_tl != END_TSO_QUEUE); - evac((StgClosure **)&run_queue_hd); - evac((StgClosure **)&run_queue_tl); - } - - if (blocked_queue_hd != END_TSO_QUEUE) { - ASSERT(blocked_queue_tl != END_TSO_QUEUE); - evac((StgClosure **)&blocked_queue_hd); - evac((StgClosure **)&blocked_queue_tl); - } - - if (sleeping_queue != END_TSO_QUEUE) { - evac((StgClosure **)&sleeping_queue); - } -#endif - if (blackhole_queue != END_TSO_QUEUE) { - evac((StgClosure **)&blackhole_queue); - } + for (i = 0; i < n_capabilities; i++) { + cap = &capabilities[i]; + evac((StgClosure **)&cap->run_queue_hd); + evac((StgClosure **)&cap->run_queue_tl); + + for (task = cap->suspended_ccalling_tasks; task != NULL; + task=task->next) { + evac((StgClosure **)&task->suspended_tso); + } + } + +#if !defined(THREADED_RTS) + evac((StgClosure **)&blocked_queue_hd); + evac((StgClosure **)&blocked_queue_tl); + evac((StgClosure **)&sleeping_queue); +#endif +#endif - if (suspended_ccalling_threads != END_TSO_QUEUE) { - evac((StgClosure **)&suspended_ccalling_threads); - } + evac((StgClosure **)&blackhole_queue); -#if defined(PARALLEL_HASKELL) || defined(GRAN) - markSparkQueue(evac); +#if defined(SMP) || defined(PARALLEL_HASKELL) || defined(GRAN) + markSparkQueue(evac); #endif - + #if defined(RTS_USER_SIGNALS) - // mark the signal handlers (signals should be already blocked) - markSignalHandlers(evac); + // mark the signal handlers (signals should be already blocked) + markSignalHandlers(evac); #endif } @@ -2792,18 +2817,23 @@ static void (*extra_roots)(evac_fn); void performGC(void) { - /* Obligated to hold this lock upon entry */ - ACQUIRE_LOCK(&sched_mutex); - GarbageCollect(GetRoots,rtsFalse); - RELEASE_LOCK(&sched_mutex); +#ifdef THREADED_RTS + // ToDo: we have to grab all the capabilities here. + errorBelch("performGC not supported in threaded RTS (yet)"); + stg_exit(EXIT_FAILURE); +#endif + /* Obligated to hold this lock upon entry */ + GarbageCollect(GetRoots,rtsFalse); } void performMajorGC(void) { - ACQUIRE_LOCK(&sched_mutex); - GarbageCollect(GetRoots,rtsTrue); - RELEASE_LOCK(&sched_mutex); +#ifdef THREADED_RTS + errorBelch("performMayjorGC not supported in threaded RTS (yet)"); + stg_exit(EXIT_FAILURE); +#endif + GarbageCollect(GetRoots,rtsTrue); } static void @@ -2816,10 +2846,12 @@ AllRoots(evac_fn evac) void performGCWithRoots(void (*get_roots)(evac_fn)) { - ACQUIRE_LOCK(&sched_mutex); - extra_roots = get_roots; - GarbageCollect(AllRoots,rtsFalse); - RELEASE_LOCK(&sched_mutex); +#ifdef THREADED_RTS + errorBelch("performGCWithRoots not supported in threaded RTS (yet)"); + stg_exit(EXIT_FAILURE); +#endif + extra_roots = get_roots; + GarbageCollect(AllRoots,rtsFalse); } /* ----------------------------------------------------------------------------- @@ -2832,7 +2864,7 @@ performGCWithRoots(void (*get_roots)(evac_fn)) -------------------------------------------------------------------------- */ static StgTSO * -threadStackOverflow(StgTSO *tso) +threadStackOverflow(Capability *cap, StgTSO *tso) { nat new_stack_size, stack_words; lnat new_tso_size; @@ -2850,7 +2882,7 @@ threadStackOverflow(StgTSO *tso) tso->sp+64))); /* Send this thread the StackOverflow exception */ - raiseAsync(tso, (StgClosure *)stackOverflow_closure); + raiseAsync(cap, tso, (StgClosure *)stackOverflow_closure); return tso; } @@ -2864,7 +2896,7 @@ threadStackOverflow(StgTSO *tso) new_tso_size = round_to_mblocks(new_tso_size); /* Be MBLOCK-friendly */ new_stack_size = new_tso_size - TSO_STRUCT_SIZEW; - IF_DEBUG(scheduler, debugBelch("== sched: increasing stack size from %d words to %d.\n", tso->stack_size, new_stack_size)); + IF_DEBUG(scheduler, sched_belch("increasing stack size from %ld words to %d.\n", (long)tso->stack_size, new_stack_size)); dest = (StgTSO *)allocate(new_tso_size); TICK_ALLOC_TSO(new_stack_size,0); @@ -2925,7 +2957,7 @@ unblockCount ( StgBlockingQueueElement *bqe, StgClosure *node ) DumpRawGranEvent(CURRENT_PROC, CURRENT_PROC, GR_RESUMEQ, ((StgTSO *)bqe), ((StgTSO *)bqe)->block_info.closure, 0, 0 /* spark_queue_len(ADVISORY_POOL) */); - if (EMPTY_RUN_QUEUE()) + if (emptyRunQueue()) emitSchedule = rtsTrue; switch (get_itbl(node)->type) { @@ -2942,15 +2974,15 @@ unblockCount ( StgBlockingQueueElement *bqe, StgClosure *node ) break; #endif default: - barf("{unblockOneLocked}Daq Qagh: unexpected closure in blocking queue"); + barf("{unblockOne}Daq Qagh: unexpected closure in blocking queue"); } } } #endif #if defined(GRAN) -static StgBlockingQueueElement * -unblockOneLocked(StgBlockingQueueElement *bqe, StgClosure *node) +StgBlockingQueueElement * +unblockOne(StgBlockingQueueElement *bqe, StgClosure *node) { StgTSO *tso; PEs node_loc, tso_loc; @@ -2989,8 +3021,8 @@ unblockOneLocked(StgBlockingQueueElement *bqe, StgClosure *node) tso->id, tso)); } #elif defined(PARALLEL_HASKELL) -static StgBlockingQueueElement * -unblockOneLocked(StgBlockingQueueElement *bqe, StgClosure *node) +StgBlockingQueueElement * +unblockOne(StgBlockingQueueElement *bqe, StgClosure *node) { StgBlockingQueueElement *next; @@ -3025,7 +3057,7 @@ unblockOneLocked(StgBlockingQueueElement *bqe, StgClosure *node) break; default: - barf("{unblockOneLocked}Daq Qagh: Unexpected IP (%#lx; %s) in blocking queue at %#lx\n", + barf("{unblockOne}Daq Qagh: Unexpected IP (%#lx; %s) in blocking queue at %#lx\n", get_itbl((StgClosure *)bqe), info_type((StgClosure *)bqe), (StgClosure *)bqe); # endif @@ -3033,10 +3065,10 @@ unblockOneLocked(StgBlockingQueueElement *bqe, StgClosure *node) IF_PAR_DEBUG(bq, debugBelch(", %p (%s)\n", bqe, info_type((StgClosure*)bqe))); return next; } +#endif -#else /* !GRAN && !PARALLEL_HASKELL */ -static StgTSO * -unblockOneLocked(StgTSO *tso) +StgTSO * +unblockOne(Capability *cap, StgTSO *tso) { StgTSO *next; @@ -3045,32 +3077,21 @@ unblockOneLocked(StgTSO *tso) tso->why_blocked = NotBlocked; next = tso->link; tso->link = END_TSO_QUEUE; - APPEND_TO_RUN_QUEUE(tso); - threadRunnable(); + + // We might have just migrated this TSO to our Capability: + if (tso->bound) { + tso->bound->cap = cap; + } + + appendToRunQueue(cap,tso); + + // we're holding a newly woken thread, make sure we context switch + // quickly so we can migrate it if necessary. + context_switch = 1; IF_DEBUG(scheduler,sched_belch("waking up thread %ld", (long)tso->id)); return next; } -#endif -#if defined(GRAN) || defined(PARALLEL_HASKELL) -INLINE_ME StgBlockingQueueElement * -unblockOne(StgBlockingQueueElement *bqe, StgClosure *node) -{ - ACQUIRE_LOCK(&sched_mutex); - bqe = unblockOneLocked(bqe, node); - RELEASE_LOCK(&sched_mutex); - return bqe; -} -#else -INLINE_ME StgTSO * -unblockOne(StgTSO *tso) -{ - ACQUIRE_LOCK(&sched_mutex); - tso = unblockOneLocked(tso); - RELEASE_LOCK(&sched_mutex); - return tso; -} -#endif #if defined(GRAN) void @@ -3122,7 +3143,7 @@ awakenBlockedQueue(StgBlockingQueueElement *q, StgClosure *node) //tso = (StgTSO *)bqe; // wastes an assignment to get the type right //tso_loc = where_is(tso); len++; - bqe = unblockOneLocked(bqe, node); + bqe = unblockOne(bqe, node); } /* if this is the BQ of an RBH, we have to put back the info ripped out of @@ -3160,8 +3181,6 @@ awakenBlockedQueue(StgBlockingQueueElement *q, StgClosure *node) { StgBlockingQueueElement *bqe; - ACQUIRE_LOCK(&sched_mutex); - IF_PAR_DEBUG(verbose, debugBelch("##-_ AwBQ for node %p on [%x]: \n", node, mytid)); @@ -3181,29 +3200,20 @@ awakenBlockedQueue(StgBlockingQueueElement *q, StgClosure *node) bqe = q; while (get_itbl(bqe)->type==TSO || get_itbl(bqe)->type==BLOCKED_FETCH) { - bqe = unblockOneLocked(bqe, node); + bqe = unblockOne(bqe, node); } - RELEASE_LOCK(&sched_mutex); } #else /* !GRAN && !PARALLEL_HASKELL */ void -awakenBlockedQueueNoLock(StgTSO *tso) -{ - while (tso != END_TSO_QUEUE) { - tso = unblockOneLocked(tso); - } -} - -void -awakenBlockedQueue(StgTSO *tso) +awakenBlockedQueue(Capability *cap, StgTSO *tso) { - ACQUIRE_LOCK(&sched_mutex); - while (tso != END_TSO_QUEUE) { - tso = unblockOneLocked(tso); - } - RELEASE_LOCK(&sched_mutex); + if (tso == NULL) return; // hack; see bug #1235728, and comments in + // Exception.cmm + while (tso != END_TSO_QUEUE) { + tso = unblockOne(cap,tso); + } } #endif @@ -3217,6 +3227,9 @@ interruptStgRts(void) { interrupted = 1; context_switch = 1; +#if defined(THREADED_RTS) + prodAllCapabilities(); +#endif } /* ----------------------------------------------------------------------------- @@ -3237,7 +3250,7 @@ interruptStgRts(void) */ static void -unblockThread(StgTSO *tso) +unblockThread(Capability *cap, StgTSO *tso) { StgBlockingQueueElement *t, **last; @@ -3340,6 +3353,12 @@ unblockThread(StgTSO *tso) blocked_queue_tl = (StgTSO *)prev; } } +#if defined(mingw32_HOST_OS) + /* (Cooperatively) signal that the worker thread should abort + * the request. + */ + abandonWorkRequest(tso->block_info.async_result->reqID); +#endif goto done; } } @@ -3372,11 +3391,11 @@ unblockThread(StgTSO *tso) tso->link = END_TSO_QUEUE; tso->why_blocked = NotBlocked; tso->block_info.closure = NULL; - PUSH_ON_RUN_QUEUE(tso); + pushOnRunQueue(cap,tso); } #else static void -unblockThread(StgTSO *tso) +unblockThread(Capability *cap, StgTSO *tso) { StgTSO *t, **last; @@ -3453,6 +3472,7 @@ unblockThread(StgTSO *tso) barf("unblockThread (Exception): TSO not found"); } +#if !defined(THREADED_RTS) case BlockedOnRead: case BlockedOnWrite: #if defined(mingw32_HOST_OS) @@ -3474,6 +3494,12 @@ unblockThread(StgTSO *tso) blocked_queue_tl = prev; } } +#if defined(mingw32_HOST_OS) + /* (Cooperatively) signal that the worker thread should abort + * the request. + */ + abandonWorkRequest(tso->block_info.async_result->reqID); +#endif goto done; } } @@ -3496,6 +3522,7 @@ unblockThread(StgTSO *tso) } barf("unblockThread (delay): TSO not found"); } +#endif default: barf("unblockThread"); @@ -3505,7 +3532,7 @@ unblockThread(StgTSO *tso) tso->link = END_TSO_QUEUE; tso->why_blocked = NotBlocked; tso->block_info.closure = NULL; - APPEND_TO_RUN_QUEUE(tso); + appendToRunQueue(cap,tso); } #endif @@ -3525,12 +3552,15 @@ unblockThread(StgTSO *tso) * -------------------------------------------------------------------------- */ static rtsBool -checkBlackHoles( void ) +checkBlackHoles (Capability *cap) { StgTSO **prev, *t; rtsBool any_woke_up = rtsFalse; StgHalfWord type; + // blackhole_queue is global: + ASSERT_LOCK_HELD(&sched_mutex); + IF_DEBUG(scheduler, sched_belch("checking threads blocked on black holes")); // ASSUMES: sched_mutex @@ -3540,7 +3570,10 @@ checkBlackHoles( void ) ASSERT(t->why_blocked == BlockedOnBlackHole); type = get_itbl(t->block_info.closure)->type; if (type != BLACKHOLE && type != CAF_BLACKHOLE) { - t = unblockOneLocked(t); + IF_DEBUG(sanity,checkTSO(t)); + t = unblockOne(cap, t); + // urk, the threads migrate to the current capability + // here, but we'd like to keep them on the original one. *prev = t; any_woke_up = rtsTrue; } else { @@ -3582,59 +3615,31 @@ checkBlackHoles( void ) * CATCH_FRAME on the stack. In either case, we strip the entire * stack and replace the thread with a zombie. * - * Locks: sched_mutex held upon entry nor exit. + * ToDo: in SMP mode, this function is only safe if either (a) we hold + * all the Capabilities (eg. in GC), or (b) we own the Capability that + * the TSO is currently blocked on or on the run queue of. * * -------------------------------------------------------------------------- */ -void -deleteThread(StgTSO *tso) -{ - if (tso->why_blocked != BlockedOnCCall && - tso->why_blocked != BlockedOnCCall_NoUnblockExc) { - raiseAsync(tso,NULL); - } -} - -#ifdef FORKPROCESS_PRIMOP_SUPPORTED -static void -deleteThreadImmediately(StgTSO *tso) -{ // for forkProcess only: - // delete thread without giving it a chance to catch the KillThread exception - - if (tso->what_next == ThreadComplete || tso->what_next == ThreadKilled) { - return; - } - - if (tso->why_blocked != BlockedOnCCall && - tso->why_blocked != BlockedOnCCall_NoUnblockExc) { - unblockThread(tso); - } - - tso->what_next = ThreadKilled; -} -#endif - void -raiseAsyncWithLock(StgTSO *tso, StgClosure *exception) +raiseAsync(Capability *cap, StgTSO *tso, StgClosure *exception) { - /* When raising async exs from contexts where sched_mutex isn't held; - use raiseAsyncWithLock(). */ - ACQUIRE_LOCK(&sched_mutex); - raiseAsync(tso,exception); - RELEASE_LOCK(&sched_mutex); + raiseAsync_(cap, tso, exception, rtsFalse, NULL); } void -raiseAsync(StgTSO *tso, StgClosure *exception) +suspendComputation(Capability *cap, StgTSO *tso, StgPtr stop_here) { - raiseAsync_(tso, exception, rtsFalse); + raiseAsync_(cap, tso, NULL, rtsFalse, stop_here); } static void -raiseAsync_(StgTSO *tso, StgClosure *exception, rtsBool stop_at_atomically) +raiseAsync_(Capability *cap, StgTSO *tso, StgClosure *exception, + rtsBool stop_at_atomically, StgPtr stop_here) { StgRetInfoTable *info; - StgPtr sp; + StgPtr sp, frame; + nat i; // Thread already dead? if (tso->what_next == ThreadComplete || tso->what_next == ThreadKilled) { @@ -3645,7 +3650,7 @@ raiseAsync_(StgTSO *tso, StgClosure *exception, rtsBool stop_at_atomically) sched_belch("raising exception in thread %ld.", (long)tso->id)); // Remove it from any blocking queues - unblockThread(tso); + unblockThread(cap,tso); sp = tso->sp; @@ -3659,8 +3664,8 @@ raiseAsync_(StgTSO *tso, StgClosure *exception, rtsBool stop_at_atomically) sp[0] = (W_)&stg_dummy_ret_closure; } - while (1) { - nat i; + frame = sp + 1; + while (stop_here == NULL || frame < stop_here) { // 1. Let the top of the stack be the "current closure" // @@ -3680,95 +3685,10 @@ raiseAsync_(StgTSO *tso, StgClosure *exception, rtsBool stop_at_atomically) // NB: if we pass an ATOMICALLY_FRAME then abort the associated // transaction - - StgPtr frame; - - frame = sp + 1; info = get_ret_itbl((StgClosure *)frame); - - while (info->i.type != UPDATE_FRAME - && (info->i.type != CATCH_FRAME || exception == NULL) - && info->i.type != STOP_FRAME - && (info->i.type != ATOMICALLY_FRAME || stop_at_atomically == rtsFalse)) - { - if (info->i.type == CATCH_RETRY_FRAME || info->i.type == ATOMICALLY_FRAME) { - // IF we find an ATOMICALLY_FRAME then we abort the - // current transaction and propagate the exception. In - // this case (unlike ordinary exceptions) we do not care - // whether the transaction is valid or not because its - // possible validity cannot have caused the exception - // and will not be visible after the abort. - IF_DEBUG(stm, - debugBelch("Found atomically block delivering async exception\n")); - stmAbortTransaction(tso -> trec); - tso -> trec = stmGetEnclosingTRec(tso -> trec); - } - frame += stack_frame_sizeW((StgClosure *)frame); - info = get_ret_itbl((StgClosure *)frame); - } - + switch (info->i.type) { - - case ATOMICALLY_FRAME: - ASSERT(stop_at_atomically); - ASSERT(stmGetEnclosingTRec(tso->trec) == NO_TREC); - stmCondemnTransaction(tso -> trec); -#ifdef REG_R1 - tso->sp = frame; -#else - // R1 is not a register: the return convention for IO in - // this case puts the return value on the stack, so we - // need to set up the stack to return to the atomically - // frame properly... - tso->sp = frame - 2; - tso->sp[1] = (StgWord) &stg_NO_FINALIZER_closure; // why not? - tso->sp[0] = (StgWord) &stg_ut_1_0_unreg_info; -#endif - tso->what_next = ThreadRunGHC; - return; - case CATCH_FRAME: - // If we find a CATCH_FRAME, and we've got an exception to raise, - // then build the THUNK raise(exception), and leave it on - // top of the CATCH_FRAME ready to enter. - // - { -#ifdef PROFILING - StgCatchFrame *cf = (StgCatchFrame *)frame; -#endif - StgClosure *raise; - - // we've got an exception to raise, so let's pass it to the - // handler in this frame. - // - raise = (StgClosure *)allocate(sizeofW(StgClosure)+1); - TICK_ALLOC_SE_THK(1,0); - SET_HDR(raise,&stg_raise_info,cf->header.prof.ccs); - raise->payload[0] = exception; - - // throw away the stack from Sp up to the CATCH_FRAME. - // - sp = frame - 1; - - /* Ensure that async excpetions are blocked now, so we don't get - * a surprise exception before we get around to executing the - * handler. - */ - if (tso->blocked_exceptions == NULL) { - tso->blocked_exceptions = END_TSO_QUEUE; - } - - /* Put the newly-built THUNK on top of the stack, ready to execute - * when the thread restarts. - */ - sp[0] = (W_)raise; - sp[-1] = (W_)&stg_enter_info; - tso->sp = sp-1; - tso->what_next = ThreadRunGHC; - IF_DEBUG(sanity, checkTSO(tso)); - return; - } - case UPDATE_FRAME: { StgAP_STACK * ap; @@ -3779,7 +3699,7 @@ raiseAsync_(StgTSO *tso, StgClosure *exception, rtsBool stop_at_atomically) // fun field. // words = frame - sp - 1; - ap = (StgAP_STACK *)allocate(PAP_sizeW(words)); + ap = (StgAP_STACK *)allocateLocal(cap,AP_STACK_sizeW(words)); ap->size = words; ap->fun = (StgClosure *)sp[0]; @@ -3799,9 +3719,7 @@ raiseAsync_(StgTSO *tso, StgClosure *exception, rtsBool stop_at_atomically) printObj((StgClosure *)ap); ); - // Replace the updatee with an indirection - happily - // this will also wake up any threads currently - // waiting on the result. + // Replace the updatee with an indirection // // Warning: if we're in a loop, more than one update frame on // the stack may point to the same object. Be careful not to @@ -3818,24 +3736,145 @@ raiseAsync_(StgTSO *tso, StgClosure *exception, rtsBool stop_at_atomically) } sp += sizeofW(StgUpdateFrame) - 1; sp[0] = (W_)ap; // push onto stack - break; + frame = sp + 1; + continue; //no need to bump frame } - + case STOP_FRAME: // We've stripped the entire stack, the thread is now dead. - sp += sizeofW(StgStopFrame); tso->what_next = ThreadKilled; - tso->sp = sp; + tso->sp = frame + sizeofW(StgStopFrame); + return; + + case CATCH_FRAME: + // If we find a CATCH_FRAME, and we've got an exception to raise, + // then build the THUNK raise(exception), and leave it on + // top of the CATCH_FRAME ready to enter. + // + { +#ifdef PROFILING + StgCatchFrame *cf = (StgCatchFrame *)frame; +#endif + StgThunk *raise; + + if (exception == NULL) break; + + // we've got an exception to raise, so let's pass it to the + // handler in this frame. + // + raise = (StgThunk *)allocateLocal(cap,sizeofW(StgThunk)+MIN_UPD_SIZE); + TICK_ALLOC_SE_THK(1,0); + SET_HDR(raise,&stg_raise_info,cf->header.prof.ccs); + raise->payload[0] = exception; + + // throw away the stack from Sp up to the CATCH_FRAME. + // + sp = frame - 1; + + /* Ensure that async excpetions are blocked now, so we don't get + * a surprise exception before we get around to executing the + * handler. + */ + if (tso->blocked_exceptions == NULL) { + tso->blocked_exceptions = END_TSO_QUEUE; + } + + /* Put the newly-built THUNK on top of the stack, ready to execute + * when the thread restarts. + */ + sp[0] = (W_)raise; + sp[-1] = (W_)&stg_enter_info; + tso->sp = sp-1; + tso->what_next = ThreadRunGHC; + IF_DEBUG(sanity, checkTSO(tso)); return; + } + + case ATOMICALLY_FRAME: + if (stop_at_atomically) { + ASSERT(stmGetEnclosingTRec(tso->trec) == NO_TREC); + stmCondemnTransaction(cap, tso -> trec); +#ifdef REG_R1 + tso->sp = frame; +#else + // R1 is not a register: the return convention for IO in + // this case puts the return value on the stack, so we + // need to set up the stack to return to the atomically + // frame properly... + tso->sp = frame - 2; + tso->sp[1] = (StgWord) &stg_NO_FINALIZER_closure; // why not? + tso->sp[0] = (StgWord) &stg_ut_1_0_unreg_info; +#endif + tso->what_next = ThreadRunGHC; + return; + } + // Not stop_at_atomically... fall through and abort the + // transaction. + + case CATCH_RETRY_FRAME: + // IF we find an ATOMICALLY_FRAME then we abort the + // current transaction and propagate the exception. In + // this case (unlike ordinary exceptions) we do not care + // whether the transaction is valid or not because its + // possible validity cannot have caused the exception + // and will not be visible after the abort. + IF_DEBUG(stm, + debugBelch("Found atomically block delivering async exception\n")); + StgTRecHeader *trec = tso -> trec; + StgTRecHeader *outer = stmGetEnclosingTRec(trec); + stmAbortTransaction(cap, trec); + tso -> trec = outer; + break; default: - barf("raiseAsync"); + break; } + + // move on to the next stack frame + frame += stack_frame_sizeW((StgClosure *)frame); } - barf("raiseAsync"); + + // if we got here, then we stopped at stop_here + ASSERT(stop_here != NULL); } /* ----------------------------------------------------------------------------- + Deleting threads + + This is used for interruption (^C) and forking, and corresponds to + raising an exception but without letting the thread catch the + exception. + -------------------------------------------------------------------------- */ + +static void +deleteThread (Capability *cap, StgTSO *tso) +{ + if (tso->why_blocked != BlockedOnCCall && + tso->why_blocked != BlockedOnCCall_NoUnblockExc) { + raiseAsync(cap,tso,NULL); + } +} + +#ifdef FORKPROCESS_PRIMOP_SUPPORTED +static void +deleteThreadImmediately(Capability *cap, StgTSO *tso) +{ // for forkProcess only: + // delete thread without giving it a chance to catch the KillThread exception + + if (tso->what_next == ThreadComplete || tso->what_next == ThreadKilled) { + return; + } + + if (tso->why_blocked != BlockedOnCCall && + tso->why_blocked != BlockedOnCCall_NoUnblockExc) { + unblockThread(cap,tso); + } + + tso->what_next = ThreadKilled; +} +#endif + +/* ----------------------------------------------------------------------------- raiseExceptionHelper This function is called by the raise# primitve, just so that we can @@ -3844,9 +3883,10 @@ raiseAsync_(StgTSO *tso, StgClosure *exception, rtsBool stop_at_atomically) -------------------------------------------------------------------------- */ StgWord -raiseExceptionHelper (StgTSO *tso, StgClosure *exception) +raiseExceptionHelper (StgRegTable *reg, StgTSO *tso, StgClosure *exception) { - StgClosure *raise_closure = NULL; + Capability *cap = regTableToCapability(reg); + StgThunk *raise_closure = NULL; StgPtr p, next; StgRetInfoTable *info; // @@ -3883,11 +3923,11 @@ raiseExceptionHelper (StgTSO *tso, StgClosure *exception) // Only create raise_closure if we need to. if (raise_closure == NULL) { raise_closure = - (StgClosure *)allocate(sizeofW(StgClosure)+MIN_UPD_SIZE); + (StgThunk *)allocateLocal(cap,sizeofW(StgThunk)+MIN_UPD_SIZE); SET_HDR(raise_closure, &stg_raise_info, CCCS); raise_closure->payload[0] = exception; } - UPD_IND(((StgUpdateFrame *)p)->updatee,raise_closure); + UPD_IND(((StgUpdateFrame *)p)->updatee,(StgClosure *)raise_closure); p = next; continue; @@ -3973,42 +4013,51 @@ findRetryFrameHelper (StgTSO *tso) on an MVar, or NonTermination if the thread was blocked on a Black Hole. - Locks: sched_mutex isn't held upon entry nor exit. + Locks: assumes we hold *all* the capabilities. -------------------------------------------------------------------------- */ void -resurrectThreads( StgTSO *threads ) +resurrectThreads (StgTSO *threads) { - StgTSO *tso, *next; - - for (tso = threads; tso != END_TSO_QUEUE; tso = next) { - next = tso->global_link; - tso->global_link = all_threads; - all_threads = tso; - IF_DEBUG(scheduler, sched_belch("resurrecting thread %d", tso->id)); - - switch (tso->why_blocked) { - case BlockedOnMVar: - case BlockedOnException: - /* Called by GC - sched_mutex lock is currently held. */ - raiseAsync(tso,(StgClosure *)BlockedOnDeadMVar_closure); - break; - case BlockedOnBlackHole: - raiseAsync(tso,(StgClosure *)NonTermination_closure); - break; - case BlockedOnSTM: - raiseAsync(tso,(StgClosure *)BlockedIndefinitely_closure); - break; - case NotBlocked: - /* This might happen if the thread was blocked on a black hole - * belonging to a thread that we've just woken up (raiseAsync - * can wake up threads, remember...). - */ - continue; - default: - barf("resurrectThreads: thread blocked in a strange way"); + StgTSO *tso, *next; + Capability *cap; + + for (tso = threads; tso != END_TSO_QUEUE; tso = next) { + next = tso->global_link; + tso->global_link = all_threads; + all_threads = tso; + IF_DEBUG(scheduler, sched_belch("resurrecting thread %d", tso->id)); + + // Wake up the thread on the Capability it was last on for a + // bound thread, or last_free_capability otherwise. + if (tso->bound) { + cap = tso->bound->cap; + } else { + cap = last_free_capability; + } + + switch (tso->why_blocked) { + case BlockedOnMVar: + case BlockedOnException: + /* Called by GC - sched_mutex lock is currently held. */ + raiseAsync(cap, tso,(StgClosure *)BlockedOnDeadMVar_closure); + break; + case BlockedOnBlackHole: + raiseAsync(cap, tso,(StgClosure *)NonTermination_closure); + break; + case BlockedOnSTM: + raiseAsync(cap, tso,(StgClosure *)BlockedIndefinitely_closure); + break; + case NotBlocked: + /* This might happen if the thread was blocked on a black hole + * belonging to a thread that we've just woken up (raiseAsync + * can wake up threads, remember...). + */ + continue; + default: + barf("resurrectThreads: thread blocked in a strange way"); + } } - } } /* ---------------------------------------------------------------------------- @@ -4017,15 +4066,16 @@ resurrectThreads( StgTSO *threads ) * at the Haskell source code level, so enable outside of DEBUG. --sof 7/02] ------------------------------------------------------------------------- */ +#if DEBUG static void printThreadBlockage(StgTSO *tso) { switch (tso->why_blocked) { case BlockedOnRead: - debugBelch("is blocked on read from fd %ld", tso->block_info.fd); + debugBelch("is blocked on read from fd %d", (int)(tso->block_info.fd)); break; case BlockedOnWrite: - debugBelch("is blocked on write to fd %ld", tso->block_info.fd); + debugBelch("is blocked on write to fd %d", (int)(tso->block_info.fd)); break; #if defined(mingw32_HOST_OS) case BlockedOnDoProc: @@ -4033,10 +4083,10 @@ printThreadBlockage(StgTSO *tso) break; #endif case BlockedOnDelay: - debugBelch("is blocked until %ld", tso->block_info.target); + debugBelch("is blocked until %ld", (long)(tso->block_info.target)); break; case BlockedOnMVar: - debugBelch("is blocked on an MVar"); + debugBelch("is blocked on an MVar @ %p", tso->block_info.closure); break; case BlockedOnException: debugBelch("is blocked on delivering an exception to thread %d", @@ -4073,25 +4123,37 @@ printThreadBlockage(StgTSO *tso) } } -static void -printThreadStatus(StgTSO *tso) +void +printThreadStatus(StgTSO *t) { - switch (tso->what_next) { - case ThreadKilled: - debugBelch("has been killed"); - break; - case ThreadComplete: - debugBelch("has completed"); - break; - default: - printThreadBlockage(tso); - } + debugBelch("\tthread %4d @ %p ", t->id, (void *)t); + { + void *label = lookupThreadLabel(t->id); + if (label) debugBelch("[\"%s\"] ",(char *)label); + } + if (t->what_next == ThreadRelocated) { + debugBelch("has been relocated...\n"); + } else { + switch (t->what_next) { + case ThreadKilled: + debugBelch("has been killed"); + break; + case ThreadComplete: + debugBelch("has completed"); + break; + default: + printThreadBlockage(t); + } + debugBelch("\n"); + } } void printAllThreads(void) { - StgTSO *t; + StgTSO *t, *next; + nat i; + Capability *cap; # if defined(GRAN) char time_string[TIME_STR_LEN], node_str[NODE_STR_LEN]; @@ -4109,20 +4171,38 @@ printAllThreads(void) debugBelch("all threads:\n"); # endif - for (t = all_threads; t != END_TSO_QUEUE; t = t->global_link) { - debugBelch("\tthread %d @ %p ", t->id, (void *)t); -#if defined(DEBUG) - { - void *label = lookupThreadLabel(t->id); - if (label) debugBelch("[\"%s\"] ",(char *)label); - } -#endif - printThreadStatus(t); - debugBelch("\n"); + for (i = 0; i < n_capabilities; i++) { + cap = &capabilities[i]; + debugBelch("threads on capability %d:\n", cap->no); + for (t = cap->run_queue_hd; t != END_TSO_QUEUE; t = t->link) { + printThreadStatus(t); + } + } + + debugBelch("other threads:\n"); + for (t = all_threads; t != END_TSO_QUEUE; t = next) { + if (t->why_blocked != NotBlocked) { + printThreadStatus(t); + } + if (t->what_next == ThreadRelocated) { + next = t->link; + } else { + next = t->global_link; + } } } - -#ifdef DEBUG + +// useful from gdb +void +printThreadQueue(StgTSO *t) +{ + nat i = 0; + for (; t != END_TSO_QUEUE; t = t->link) { + printThreadStatus(t); + i++; + } + debugBelch("%d threads on queue\n", i); +} /* Print a whole blocking queue attached to node (debugging only). @@ -4260,33 +4340,34 @@ print_bq (StgClosure *node) static nat run_queue_len(void) { - nat i; - StgTSO *tso; - - for (i=0, tso=run_queue_hd; - tso != END_TSO_QUEUE; - i++, tso=tso->link) - /* nothing */ - - return i; + nat i; + StgTSO *tso; + + for (i=0, tso=run_queue_hd; + tso != END_TSO_QUEUE; + i++, tso=tso->link) { + /* nothing */ + } + + return i; } #endif void sched_belch(char *s, ...) { - va_list ap; - va_start(ap,s); -#ifdef RTS_SUPPORTS_THREADS - debugBelch("sched (task %p): ", osThreadId()); + va_list ap; + va_start(ap,s); +#ifdef THREADED_RTS + debugBelch("sched (task %p): ", (void *)(unsigned long)(unsigned int)osThreadId()); #elif defined(PARALLEL_HASKELL) - debugBelch("== "); + debugBelch("== "); #else - debugBelch("sched: "); + debugBelch("sched: "); #endif - vdebugBelch(s, ap); - debugBelch("\n"); - va_end(ap); + vdebugBelch(s, ap); + debugBelch("\n"); + va_end(ap); } #endif /* DEBUG */