X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=ghc%2Frts%2FSchedule.c;h=52fd4d5df655f76668314dc399cb0fca1111d88c;hb=c520a3a2752ffcec5710a88a8a2e219c20edfc8a;hp=6f4e5f963855585b18b3978f661fca1886ab4760;hpb=c435fef8d44b5681ccee43efe588d5b6bdd71e72;p=ghc-hetmet.git diff --git a/ghc/rts/Schedule.c b/ghc/rts/Schedule.c index 6f4e5f9..52fd4d5 100644 --- a/ghc/rts/Schedule.c +++ b/ghc/rts/Schedule.c @@ -1,58 +1,27 @@ /* --------------------------------------------------------------------------- * - * (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 PAR 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" #include "RtsUtils.h" #include "RtsFlags.h" #include "BlockAlloc.h" +#include "OSThreads.h" #include "Storage.h" #include "StgRun.h" #include "Hooks.h" -#define COMPILING_SCHEDULER #include "Schedule.h" #include "StgMiscClosures.h" -#include "Storage.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" @@ -65,7 +34,7 @@ #include "Proftimer.h" #include "ProfHeap.h" #endif -#if defined(GRAN) || defined(PAR) +#if defined(GRAN) || defined(PARALLEL_HASKELL) # include "GranSimRts.h" # include "GranSim.h" # include "ParallelRts.h" @@ -76,8 +45,11 @@ #endif #include "Sparks.h" #include "Capability.h" -#include "OSThreads.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 @@ -94,26 +66,16 @@ #include #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 +// Turn off inlining when debugging - it obfuscates things +#ifdef DEBUG +# undef STATIC_INLINE +# define STATIC_INLINE static #endif -/* Main thread queue. - * Locks required: sched_mutex. - */ -StgMainThread *main_threads = NULL; +/* ----------------------------------------------------------------------------- + * Global variables + * -------------------------------------------------------------------------- */ -/* Thread queues. - * Locks required: sched_mutex. - */ #if defined(GRAN) StgTSO* ActiveTSO = NULL; /* for assigning system costs; GranSim-Light only */ @@ -136,54 +98,52 @@ StgTSO *ccalling_threadss[MAX_PROC]; #else /* !GRAN */ -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 *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; - -static StgTSO *threadStackOverflow(StgTSO *tso); - -/* 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) */ -rtsBool in_haskell = rtsFalse; +rtsBool sched_state = SCHED_RUNNING; /* 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) @@ -194,10 +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 @@ -208,42 +166,96 @@ StgTSO *CurrentTSO; */ StgTSO dummy_tso; -static rtsBool ready_to_gc; - /* * Set to TRUE when entering a shutdown state (via shutdownHaskellAndExit()) -- * 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; -void addToBlockedQueue ( StgTSO *tso ); - -static void schedule ( StgMainThread *mainThread, Capability *initialCapability ); - void interruptStgRts ( void ); +/* + * This mutex protects most of the global scheduler data in + * the THREADED_RTS runtime. + */ +#if defined(THREADED_RTS) +Mutex sched_mutex; +#endif -#if !defined(PAR) && !defined(RTS_SUPPORTS_THREADS) -static void detectBlackHoles ( void ); +#if defined(PARALLEL_HASKELL) +StgTSO *LastTSO; +rtsTime TimeOfLastYield; +rtsBool emitSchedule = rtsTrue; #endif -static void raiseAsync_(StgTSO *tso, StgClosure *exception, rtsBool stop_at_atomically); +/* ----------------------------------------------------------------------------- + * static function prototypes + * -------------------------------------------------------------------------- */ + +static Capability *schedule (Capability *initialCapability, Task *task); -#if defined(RTS_SUPPORTS_THREADS) -/* ToDo: carefully document the invariants that go together - * with these synchronisation objects. - */ -Mutex sched_mutex = INIT_MUTEX_VAR; -Mutex term_mutex = INIT_MUTEX_VAR; +// +// 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); +#if defined(THREADED_RTS) +static void schedulePushWork(Capability *cap, Task *task); +#endif +static void scheduleStartSignalHandlers (Capability *cap); +static void scheduleCheckBlockedThreads (Capability *cap); +static void scheduleCheckWakeupThreads(Capability *cap USED_IF_NOT_THREADS); +static void scheduleCheckBlackHoles (Capability *cap); +static void scheduleDetectDeadlock (Capability *cap, Task *task); +#if defined(GRAN) +static StgTSO *scheduleProcessEvent(rtsEvent *event); +#endif +#if defined(PARALLEL_HASKELL) +static StgTSO *scheduleSendPendingMessages(void); +static void scheduleActivateSpark(void); +static rtsBool scheduleGetRemoteWork(rtsBool *receivedFinish); +#endif +#if defined(PAR) || defined(GRAN) +static void scheduleGranParReport(void); +#endif +static void schedulePostRunThread(void); +static rtsBool scheduleHandleHeapOverflow( Capability *cap, StgTSO *t ); +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( Capability *cap, Task *task, + StgTSO *t ); +static rtsBool scheduleDoHeapProfile(rtsBool ready_to_gc); +static Capability *scheduleDoGC(Capability *cap, Task *task, + rtsBool force_major, + void (*get_roots)(evac_fn)); + +static void unblockThread(Capability *cap, StgTSO *tso); +static rtsBool checkBlackHoles(Capability *cap); +static void AllRoots(evac_fn evac); + +static StgTSO *threadStackOverflow(Capability *cap, StgTSO *tso); + +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 deleteAllThreads (Capability *cap); -#endif /* RTS_SUPPORTS_THREADS */ +#ifdef DEBUG +static void printThreadBlockage(StgTSO *tso); +static void printThreadStatus(StgTSO *tso); +void printThreadQueue(StgTSO *tso); +#endif -#if defined(PAR) -StgTSO *LastTSO; -rtsTime TimeOfLastYield; -rtsBool emitSchedule = rtsTrue; +#if defined(PARALLEL_HASKELL) +StgTSO * createSparkThread(rtsSpark spark); +StgTSO * activateSpark (rtsSpark spark); #endif -#if DEBUG +#ifdef DEBUG static char *whatNext_strs[] = { "(unknown)", "ThreadRunGHC", @@ -254,48 +266,26 @@ static char *whatNext_strs[] = { }; #endif -#if defined(PAR) -StgTSO * createSparkThread(rtsSpark spark); -StgTSO * activateSpark (rtsSpark spark); -#endif - -/* ---------------------------------------------------------------------------- - * Starting Tasks - * ------------------------------------------------------------------------- */ - -#if defined(RTS_SUPPORTS_THREADS) -static rtsBool startingWorkerThread = rtsFalse; +/* ----------------------------------------------------------------------------- + * Putting a thread on the run queue: different scheduling policies + * -------------------------------------------------------------------------- */ -static void taskStart(void); -static void -taskStart(void) +STATIC_INLINE void +addToRunQueue( Capability *cap, StgTSO *t ) { - ACQUIRE_LOCK(&sched_mutex); - startingWorkerThread = rtsFalse; - schedule(NULL,NULL); - RELEASE_LOCK(&sched_mutex); -} - -void -startSchedulerTaskIfNecessary(void) -{ - if(run_queue_hd != END_TSO_QUEUE - || blocked_queue_hd != END_TSO_QUEUE - || sleeping_queue != END_TSO_QUEUE) - { - if(!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(!startTask(taskStart)) - { - startingWorkerThread = rtsFalse; - } +#if defined(PARALLEL_HASKELL) + if (RtsFlags.ParFlags.doFairScheduling) { + // this does round-robin scheduling; good for concurrency + appendToRunQueue(cap,t); + } else { + // this does unfair scheduling; good for parallelism + pushOnRunQueue(cap,t); } - } -} +#else + // this does round-robin scheduling; good for concurrency + appendToRunQueue(cap,t); #endif +} /* --------------------------------------------------------------------------- Main scheduling loop. @@ -309,13 +299,6 @@ startSchedulerTaskIfNecessary(void) * 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 @@ -332,18 +315,16 @@ startSchedulerTaskIfNecessary(void) This is not the ugliest code you could imagine, but it's bloody close. ------------------------------------------------------------------------ */ -static void -schedule( StgMainThread *mainThread USED_WHEN_RTS_SUPPORTS_THREADS, - Capability *initialCapability ) + +static Capability * +schedule (Capability *initialCapability, Task *task) { StgTSO *t; Capability *cap; StgThreadReturnCode ret; #if defined(GRAN) rtsEvent *event; -#elif defined(PAR) - StgSparkPool *pool; - rtsSpark spark; +#elif defined(PARALLEL_HASKELL) StgTSO *tso; GlobalTaskId pe; rtsBool receivedFinish = rtsFalse; @@ -351,248 +332,754 @@ schedule( StgMainThread *mainThread USED_WHEN_RTS_SUPPORTS_THREADS, nat tp_size, sp_size; // stats only # endif #endif - rtsBool was_interrupted = rtsFalse; 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) - // - // in the threaded case, the capability is either passed in via the - // initialCapability parameter, or initialized inside the scheduler - // loop - // + // 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); ); -#else - // simply initialise it in the non-threaded case - grabCapability(&cap); -#endif -#if defined(GRAN) - /* set up first event to get things going */ - /* ToDo: assign costs for system setup and init MainTSO ! */ - new_event(CurrentProc, CurrentProc, CurrentTime[CurrentProc], - ContinueThread, - CurrentTSO, (StgClosure*)NULL, (rtsSpark*)NULL); - - IF_DEBUG(gran, - debugBelch("GRAN: Init CurrentTSO (in schedule) = %p\n", CurrentTSO); - G_TSO(CurrentTSO, 5)); - - if (RtsFlags.GranFlags.Light) { - /* Save current time; GranSim Light only */ - CurrentTSO->gran.clock = CurrentTime[CurrentProc]; - } - - event = get_next_event(); - - while (event!=(rtsEvent*)NULL) { - /* Choose the processor with the next event */ - CurrentProc = event->proc; - CurrentTSO = event->tso; - -#elif defined(PAR) - - while (!receivedFinish) { /* set by processMessages */ - /* when receiving PP_FINISH message */ - -#else // everything except GRAN and PAR + schedulePreLoop(); - while (1) { + // ----------------------------------------------------------- + // Scheduler loop starts here: +#if defined(PARALLEL_HASKELL) +#define TERMINATION_CONDITION (!receivedFinish) +#elif defined(GRAN) +#define TERMINATION_CONDITION ((event = get_next_event()) != (rtsEvent*)NULL) +#else +#define TERMINATION_CONDITION rtsTrue #endif - IF_DEBUG(scheduler, printAllThreads()); + while (TERMINATION_CONDITION) { -#if defined(RTS_SUPPORTS_THREADS) - // Yield the capability to higher-priority tasks if necessary. - // - if (cap != NULL) { - yieldCapability(&cap); - } +#if defined(GRAN) + /* Choose the processor with the next event */ + CurrentProc = event->proc; + CurrentTSO = event->tso; +#endif - // 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 + +#if defined(THREADED_RTS) + 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); } + // The interruption / shutdown sequence. + // + // In order to cleanly shut down the runtime, we want to: + // * make sure that all main threads return to their callers + // with the state 'Interrupted'. + // * clean up all OS threads assocated with the runtime + // * free all memory etc. // - // If we're interrupted (the user pressed ^C, or some other - // termination condition occurred), kill all the currently running - // threads. + // So the sequence for ^C goes like this: // - if (interrupted) { - IF_DEBUG(scheduler, sched_belch("interrupted")); - interrupted = rtsFalse; - was_interrupted = rtsTrue; -#if defined(RTS_SUPPORTS_THREADS) - // In the threaded RTS, deadlock detection doesn't work, - // so just exit right away. - errorBelch("interrupted"); - releaseCapability(cap); - RELEASE_LOCK(&sched_mutex); - shutdownHaskellAndExit(EXIT_SUCCESS); -#else - deleteAllThreads(); + // * ^C handler sets sched_state := SCHED_INTERRUPTING and + // arranges for some Capability to wake up + // + // * all threads in the system are halted, and the zombies are + // placed on the run queue for cleaning up. We acquire all + // the capabilities in order to delete the threads, this is + // done by scheduleDoGC() for convenience (because GC already + // needs to acquire all the capabilities). We can't kill + // threads involved in foreign calls. + // + // * sched_state := SCHED_INTERRUPTED + // + // * somebody calls shutdownHaskell(), which calls exitScheduler() + // + // * sched_state := SCHED_SHUTTING_DOWN + // + // * all workers exit when the run queue on their capability + // drains. All main threads will also exit when their TSO + // reaches the head of the run queue and they can return. + // + // * eventually all Capabilities will shut down, and the RTS can + // exit. + // + // * We might be left with threads blocked in foreign calls, + // we should really attempt to kill these somehow (TODO); + + switch (sched_state) { + case SCHED_RUNNING: + break; + case SCHED_INTERRUPTING: + IF_DEBUG(scheduler, sched_belch("SCHED_INTERRUPTING")); +#if defined(THREADED_RTS) + discardSparksCap(cap); #endif + /* scheduleDoGC() deletes all the threads */ + cap = scheduleDoGC(cap,task,rtsFalse,GetRoots); + break; + case SCHED_INTERRUPTED: + IF_DEBUG(scheduler, sched_belch("SCHED_INTERRUPTED")); + break; + case SCHED_SHUTTING_DOWN: + IF_DEBUG(scheduler, sched_belch("SCHED_SHUTTING_DOWN")); + // 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; + } + break; + default: + barf("sched_state: %d", sched_state); } -#if defined(RTS_USER_SIGNALS) - // check for signals each time around the scheduler - if (signals_pending()) { - RELEASE_LOCK(&sched_mutex); /* ToDo: kill */ - startSignalHandlers(); - ACQUIRE_LOCK(&sched_mutex); +#if defined(THREADED_RTS) + // If the run queue is empty, take a spark and turn it into a thread. + { + if (emptyRunQueue(cap)) { + StgClosure *spark; + spark = findSpark(cap); + if (spark != NULL) { + IF_DEBUG(scheduler, + sched_belch("turning spark of closure %p into a thread", + (StgClosure *)spark)); + createSparkThread(cap,spark); + } + } } +#endif // THREADED_RTS + + 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 (emptyRunQueue(cap)) { scheduleCheckBlackHoles(cap); } + + scheduleCheckWakeupThreads(cap); + + scheduleCheckBlockedThreads(cap); + + scheduleDetectDeadlock(cap,task); +#if defined(THREADED_RTS) + cap = task->cap; // reload cap, it might have changed #endif + // Normally, the only way we can get here with no threads to + // run is if a keyboard interrupt received during + // scheduleCheckBlockedThreads() or scheduleDetectDeadlock(). + // Additionally, it is not fatal for the + // threaded RTS to reach here with no threads to run. // - // 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 defined(RTS_SUPPORTS_THREADS) - // We shouldn't be here... - barf("schedule: awaitEvent() in threaded RTS"); + // win32: might be here due to awaitEvent() being abandoned + // as a result of a console event having been delivered. + if ( emptyRunQueue(cap) ) { +#if !defined(THREADED_RTS) && !defined(mingw32_HOST_OS) + ASSERT(sched_state >= SCHED_INTERRUPTING); #endif - awaitEvent( EMPTY_RUN_QUEUE() ); + continue; // nothing to do } - // we can be interrupted while waiting for I/O... - if (interrupted) continue; - /* - * Detect deadlock: when we have no threads to run, there are no - * threads waiting on I/O or sleeping, and all the other tasks are - * waiting for work, we must have a deadlock of some description. - * - * We first try to find threads blocked on themselves (ie. black - * holes), and generate NonTermination exceptions where necessary. - * - * If no threads are black holed, we have a deadlock situation, so - * inform all the main threads. - */ -#if !defined(PAR) && !defined(RTS_SUPPORTS_THREADS) - if ( EMPTY_THREAD_QUEUES() ) - { - IF_DEBUG(scheduler, sched_belch("deadlocked, forcing major GC...")); +#if defined(PARALLEL_HASKELL) + scheduleSendPendingMessages(); + if (emptyRunQueue(cap) && scheduleActivateSpark()) + continue; - // Garbage collection can release some new threads due to - // either (a) finalizers or (b) threads resurrected because - // 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() ) { goto not_deadlocked; } +#if defined(SPARKS) + ASSERT(next_fish_to_send_at==0); // i.e. no delayed fishes left! +#endif -#if defined(RTS_USER_SIGNALS) - /* If we have user-installed signal handlers, then wait - * for signals to arrive rather then bombing out with a - * deadlock. - */ - if ( anyUserHandlers() ) { - IF_DEBUG(scheduler, - sched_belch("still deadlocked, waiting for signals...")); + /* If we still have no work we need to send a FISH to get a spark + from another PE */ + if (emptyRunQueue(cap)) { + if (!scheduleGetRemoteWork(&receivedFinish)) continue; + ASSERT(rtsFalse); // should not happen at the moment + } + // from here: non-empty run queue. + // TODO: merge above case with this, only one call processMessages() ! + if (PacketsWaiting()) { /* process incoming messages, if + any pending... only in else + because getRemoteWork waits for + messages as well */ + receivedFinish = processMessages(); + } +#endif - awaitUserSignals(); +#if defined(GRAN) + scheduleProcessEvent(event); +#endif - // we might be interrupted... - if (interrupted) { continue; } + // + // Get a thread to run + // + t = popRunQueue(cap); - if (signals_pending()) { - RELEASE_LOCK(&sched_mutex); - startSignalHandlers(); - ACQUIRE_LOCK(&sched_mutex); - } - ASSERT(!EMPTY_RUN_QUEUE()); - goto not_deadlocked; - } +#if defined(GRAN) || defined(PAR) + scheduleGranParReport(); // some kind of debuging output +#else + // Sanity check the thread we're about to run. This can be + // expensive if there is lots of thread switching going on... + IF_DEBUG(sanity,checkTSO(t)); #endif - /* 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). - */ - { - StgMainThread *m; - m = main_threads; - switch (m->tso->why_blocked) { - case BlockedOnBlackHole: - case BlockedOnException: - case BlockedOnMVar: - raiseAsync(m->tso, (StgClosure *)NonTermination_closure); - break; - default: - barf("deadlock: main thread blocked in a strange way"); +#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. + { + Task *bound = t->bound; + + 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; } } } - not_deadlocked: - -#elif defined(RTS_SUPPORTS_THREADS) - // ToDo: add deadlock detection in threaded RTS -#elif defined(PAR) - // ToDo: add deadlock detection in GUM (similar to SMP) -- HWL #endif -#if defined(RTS_SUPPORTS_THREADS) || defined(mingw32_HOST_OS) - /* win32: might be back here due to awaitEvent() being abandoned - * as a result of a console event having been delivered. + cap->r.rCurrentTSO = t; + + /* context switches are initiated by the timer signal, unless + * the user specified "context switch as often as possible", with + * +RTS -C0 */ - if ( EMPTY_RUN_QUEUE() ) { - continue; // nothing to do + if (RtsFlags.ConcFlags.ctxtSwitchTicks == 0 + && !emptyThreadQueues(cap)) { + context_switch = 1; } + +run_thread: + + IF_DEBUG(scheduler, sched_belch("-->> running thread %ld %s ...", + (long)t->id, whatNext_strs[t->what_next])); + +#if defined(PROFILING) + startHeapProfTimer(); #endif -#if defined(GRAN) - if (RtsFlags.GranFlags.Light) - GranSimLight_enter_system(event, &ActiveTSO); // adjust ActiveTSO etc + // ---------------------------------------------------------------------- + // Run the current thread - /* adjust time based on time-stamp */ - if (event->time > CurrentTime[CurrentProc] && - event->evttype != ContinueThread) - CurrentTime[CurrentProc] = event->time; + ASSERT_FULL_CAPABILITY_INVARIANTS(cap,task); + ASSERT(t->cap == cap); + + prev_what_next = t->what_next; + + errno = t->saved_errno; + cap->in_haskell = rtsTrue; + + dirtyTSO(t); + + recent_activity = ACTIVITY_YES; + + switch (prev_what_next) { + + case ThreadKilled: + case ThreadComplete: + /* Thread already finished, return to scheduler. */ + ret = ThreadFinished; + break; + + case ThreadRunGHC: + { + StgRegTable *r; + r = StgRun((StgFunPtr) stg_returnToStackTop, &cap->r); + cap = regTableToCapability(r); + ret = r->rRet; + break; + } - /* Deal with the idle PEs (may issue FindWork or MoveSpark events) */ - if (!RtsFlags.GranFlags.Light) - handleIdlePEs(); + case ThreadInterpret: + cap = interpretBCO(cap); + ret = cap->r.rRet; + break; + + default: + barf("schedule: invalid what_next field"); + } - IF_DEBUG(gran, debugBelch("GRAN: switch by event-type\n")); + cap->in_haskell = rtsFalse; - /* main event dispatcher in GranSim */ - switch (event->evttype) { - /* Should just be continuing execution */ - case ContinueThread: - IF_DEBUG(gran, debugBelch("GRAN: doing ContinueThread\n")); - /* ToDo: check assertion - ASSERT(run_queue_hd != (StgTSO*)NULL && - run_queue_hd != END_TSO_QUEUE); - */ - /* Ignore ContinueThreads for fetching threads (if synchr comm) */ - if (!RtsFlags.GranFlags.DoAsyncFetch && - procStatus[CurrentProc]==Fetching) { - debugBelch("ghuH: Spurious ContinueThread while Fetching ignored; TSO %d (%p) [PE %d]\n", + // 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; + +#if defined(THREADED_RTS) + // 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); + ASSERT(t->cap == cap); + + // ---------------------------------------------------------------------- + + // Costs for the scheduler are assigned to CCS_SYSTEM +#if defined(PROFILING) + stopHeapProfTimer(); + CCCS = CCS_SYSTEM; +#endif + +#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 + + schedulePostRunThread(); + + ready_to_gc = rtsFalse; + + switch (ret) { + case HeapOverflow: + ready_to_gc = scheduleHandleHeapOverflow(cap,t); + break; + + case StackOverflow: + scheduleHandleStackOverflow(cap,task,t); + break; + + case ThreadYielding: + if (scheduleHandleYield(cap, t, prev_what_next)) { + // shortcut for switching between compiler/interpreter: + goto run_thread; + } + break; + + case ThreadBlocked: + scheduleHandleThreadBlocked(t); + break; + + case ThreadFinished: + 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)) { ready_to_gc = rtsFalse; } + if (ready_to_gc) { + cap = scheduleDoGC(cap,task,rtsFalse,GetRoots); + } + } /* end of while() */ + + IF_PAR_DEBUG(verbose, + debugBelch("== Leaving schedule() after having received Finish\n")); +} + +/* ---------------------------------------------------------------------------- + * Setting up the scheduler loop + * ------------------------------------------------------------------------- */ + +static void +schedulePreLoop(void) +{ +#if defined(GRAN) + /* set up first event to get things going */ + /* ToDo: assign costs for system setup and init MainTSO ! */ + new_event(CurrentProc, CurrentProc, CurrentTime[CurrentProc], + ContinueThread, + CurrentTSO, (StgClosure*)NULL, (rtsSpark*)NULL); + + IF_DEBUG(gran, + debugBelch("GRAN: Init CurrentTSO (in schedule) = %p\n", + CurrentTSO); + G_TSO(CurrentTSO, 5)); + + if (RtsFlags.GranFlags.Light) { + /* Save current time; GranSim Light only */ + CurrentTSO->gran.clock = CurrentTime[CurrentProc]; + } +#endif +} + +/* ----------------------------------------------------------------------------- + * schedulePushWork() + * + * Push work to other Capabilities if we have some. + * -------------------------------------------------------------------------- */ + +#if defined(THREADED_RTS) +static void +schedulePushWork(Capability *cap USED_IF_THREADS, + Task *task USED_IF_THREADS) +{ + Capability *free_caps[n_capabilities], *cap0; + nat i, n_free_caps; + + // migration can be turned off with +RTS -qg + if (!RtsFlags.ParFlags.migrate) return; + + // 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 + || tsoLocked(t)) { // don't move a locked 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]; } + t->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 + * ------------------------------------------------------------------------- */ + +#if defined(RTS_USER_SIGNALS) && (!defined(THREADED_RTS) || defined(mingw32_HOST_OS)) +static void +scheduleStartSignalHandlers(Capability *cap) +{ + if (signals_pending()) { // safe outside the lock + startSignalHandlers(cap); + } +} +#else +static void +scheduleStartSignalHandlers(Capability *cap STG_UNUSED) +{ +} +#endif + +/* ---------------------------------------------------------------------------- + * Check for blocked threads that can be woken up. + * ------------------------------------------------------------------------- */ + +static 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 ( !emptyQueue(blocked_queue_hd) || !emptyQueue(sleeping_queue) ) + { + awaitEvent( emptyRunQueue(cap) && !blackholes_need_checking ); + } +#endif +} + + +/* ---------------------------------------------------------------------------- + * Check for threads woken up by other Capabilities + * ------------------------------------------------------------------------- */ + +static void +scheduleCheckWakeupThreads(Capability *cap USED_IF_THREADS) +{ +#if defined(THREADED_RTS) + // Any threads that were woken up by other Capabilities get + // appended to our run queue. + if (!emptyWakeupQueue(cap)) { + ACQUIRE_LOCK(&cap->lock); + if (emptyRunQueue(cap)) { + cap->run_queue_hd = cap->wakeup_queue_hd; + cap->run_queue_tl = cap->wakeup_queue_tl; + } else { + cap->run_queue_tl->link = cap->wakeup_queue_hd; + cap->run_queue_tl = cap->wakeup_queue_tl; + } + cap->wakeup_queue_hd = cap->wakeup_queue_tl = END_TSO_QUEUE; + RELEASE_LOCK(&cap->lock); + } +#endif +} + +/* ---------------------------------------------------------------------------- + * Check for threads blocked on BLACKHOLEs that can be woken up + * ------------------------------------------------------------------------- */ +static void +scheduleCheckBlackHoles (Capability *cap) +{ + if ( blackholes_need_checking ) // check without the lock first + { + 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. + * ------------------------------------------------------------------------- */ + +static void +scheduleDetectDeadlock (Capability *cap, Task *task) +{ + +#if defined(PARALLEL_HASKELL) + // ToDo: add deadlock detection in GUM (similar to THREADED_RTS) -- 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 ( emptyThreadQueues(cap) ) + { +#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 + // either (a) finalizers or (b) threads resurrected because + // they are unreachable and will therefore be sent an + // exception. Any threads thus released will be immediately + // runnable. + cap = scheduleDoGC (cap, task, rtsTrue/*force major GC*/, GetRoots); + + recent_activity = ACTIVITY_DONE_GC; + + if ( !emptyRunQueue(cap) ) return; + +#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. + */ + if ( anyUserHandlers() ) { + IF_DEBUG(scheduler, + sched_belch("still deadlocked, waiting for signals...")); + + awaitUserSignals(); + + if (signals_pending()) { + startSignalHandlers(cap); + } + + // either we have threads to run, or we were interrupted: + ASSERT(!emptyRunQueue(cap) || sched_state >= SCHED_INTERRUPTING); + } +#endif + +#if !defined(THREADED_RTS) + /* Probably a real deadlock. Send the current main thread the + * Deadlock exception. + */ + if (task->tso) { + switch (task->tso->why_blocked) { + case BlockedOnSTM: + case BlockedOnBlackHole: + case BlockedOnException: + case BlockedOnMVar: + raiseAsync(cap, task->tso, (StgClosure *)NonTermination_closure); + return; + default: + barf("deadlock: main thread blocked in a strange way"); + } + } + return; +#endif + } +} + +/* ---------------------------------------------------------------------------- + * Process an event (GRAN only) + * ------------------------------------------------------------------------- */ + +#if defined(GRAN) +static StgTSO * +scheduleProcessEvent(rtsEvent *event) +{ + StgTSO *t; + + if (RtsFlags.GranFlags.Light) + GranSimLight_enter_system(event, &ActiveTSO); // adjust ActiveTSO etc + + /* adjust time based on time-stamp */ + if (event->time > CurrentTime[CurrentProc] && + event->evttype != ContinueThread) + CurrentTime[CurrentProc] = event->time; + + /* Deal with the idle PEs (may issue FindWork or MoveSpark events) */ + if (!RtsFlags.GranFlags.Light) + handleIdlePEs(); + + IF_DEBUG(gran, debugBelch("GRAN: switch by event-type\n")); + + /* main event dispatcher in GranSim */ + switch (event->evttype) { + /* Should just be continuing execution */ + case ContinueThread: + IF_DEBUG(gran, debugBelch("GRAN: doing ContinueThread\n")); + /* ToDo: check assertion + ASSERT(run_queue_hd != (StgTSO*)NULL && + run_queue_hd != END_TSO_QUEUE); + */ + /* Ignore ContinueThreads for fetching threads (if synchr comm) */ + if (!RtsFlags.GranFlags.DoAsyncFetch && + procStatus[CurrentProc]==Fetching) { + debugBelch("ghuH: Spurious ContinueThread while Fetching ignored; TSO %d (%p) [PE %d]\n", CurrentTSO->id, CurrentTSO, CurrentProc); goto next_thread; } @@ -700,18 +1187,54 @@ schedule( StgMainThread *mainThread USED_WHEN_RTS_SUPPORTS_THREADS, DumpGranEvent(GR_SCHEDULE, t)); procStatus[CurrentProc] = Busy; +} +#endif // GRAN -#elif defined(PAR) +/* ---------------------------------------------------------------------------- + * Send pending messages (PARALLEL_HASKELL only) + * ------------------------------------------------------------------------- */ + +#if defined(PARALLEL_HASKELL) +static StgTSO * +scheduleSendPendingMessages(void) +{ + StgSparkPool *pool; + rtsSpark spark; + StgTSO *t; + +# if defined(PAR) // global Mem.Mgmt., omit for now if (PendingFetches != END_BF_QUEUE) { processFetches(); } +# endif + + if (RtsFlags.ParFlags.BufferTime) { + // if we use message buffering, we must send away all message + // packets which have become too old... + sendOldBuffers(); + } +} +#endif + +/* ---------------------------------------------------------------------------- + * Activate spark threads (PARALLEL_HASKELL only) + * ------------------------------------------------------------------------- */ + +#if defined(PARALLEL_HASKELL) +static void +scheduleActivateSpark(void) +{ +#if defined(SPARKS) + 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 + loop. +*/ - /* ToDo: phps merge with spark activation above */ - /* check whether we have local work and send requests if we have none */ - if (EMPTY_RUN_QUEUE()) { /* no runnable threads */ /* :-[ no local threads => look out for local sparks */ /* the spark pool for the current PE */ - pool = &(MainRegTable.rSparks); // generalise to cap = &MainRegTable + pool = &(cap.r.rSparks); // JB: cap = (old) MainCap if (advisory_thread_count < RtsFlags.ParFlags.maxThreads && pool->hd < pool->tl) { /* @@ -723,29 +1246,73 @@ schedule( StgMainThread *mainThread USED_WHEN_RTS_SUPPORTS_THREADS, * thread... */ - spark = findSpark(rtsFalse); /* get a spark */ - if (spark != (rtsSpark) NULL) { - tso = activateSpark(spark); /* turn the spark into a thread */ - IF_PAR_DEBUG(schedule, - debugBelch("==== schedule: Created TSO %d (%p); %d threads active\n", - tso->id, tso, advisory_thread_count)); - - if (tso==END_TSO_QUEUE) { /* failed to activate spark->back to loop */ - debugBelch("==^^ failed to activate spark\n"); - goto next_thread; - } /* otherwise fall through & pick-up new tso */ - } else { - IF_PAR_DEBUG(verbose, - debugBelch("==^^ no local sparks (spark pool contains only NFs: %d)\n", - spark_queue_len(pool))); - goto next_thread; + spark = findSpark(rtsFalse); /* get a spark */ + if (spark != (rtsSpark) NULL) { + tso = createThreadFromSpark(spark); /* turn the spark into a thread */ + IF_PAR_DEBUG(fish, // schedule, + debugBelch("==== schedule: Created TSO %d (%p); %d threads active\n", + tso->id, tso, advisory_thread_count)); + + if (tso==END_TSO_QUEUE) { /* failed to activate spark->back to loop */ + IF_PAR_DEBUG(fish, // schedule, + debugBelch("==^^ failed to create thread from spark @ %lx\n", + spark)); + return rtsFalse; /* failed to generate a thread */ + } /* otherwise fall through & pick-up new tso */ + } else { + IF_PAR_DEBUG(fish, // schedule, + debugBelch("==^^ no local sparks (spark pool contains only NFs: %d)\n", + spark_queue_len(pool))); + return rtsFalse; /* failed to generate a thread */ + } + return rtsTrue; /* success in generating a thread */ + } else { /* no more threads permitted or pool empty */ + return rtsFalse; /* failed to generateThread */ + } +#else + tso = NULL; // avoid compiler warning only + return rtsFalse; /* dummy in non-PAR setup */ +#endif // SPARKS +} +#endif // PARALLEL_HASKELL + +/* ---------------------------------------------------------------------------- + * Get work from a remote node (PARALLEL_HASKELL only) + * ------------------------------------------------------------------------- */ + +#if defined(PARALLEL_HASKELL) +static rtsBool +scheduleGetRemoteWork(rtsBool *receivedFinish) +{ + ASSERT(emptyRunQueue()); + + if (RtsFlags.ParFlags.BufferTime) { + IF_PAR_DEBUG(verbose, + debugBelch("...send all pending data,")); + { + nat i; + for (i=1; i<=nPEs; i++) + sendImmediately(i); // send all messages away immediately } - } + } +# ifndef SPARKS + //++EDEN++ idle() , i.e. send all buffers, wait for work + // suppress fishing in EDEN... just look for incoming messages + // (blocking receive) + IF_PAR_DEBUG(verbose, + debugBelch("...wait for incoming messages...\n")); + *receivedFinish = processMessages(); // blocking receive... + + // and reenter scheduling loop after having received something + // (return rtsFalse below) + +# else /* activate SPARKS machinery */ +/* We get here, if we have no work, tried to activate a local spark, but still + have no work. We try to get a remote spark, by sending a FISH message. + Thread migration should be added here, and triggered when a sequence of + fishes returns without work. */ + delay = (RtsFlags.ParFlags.fishDelay!=0ll ? RtsFlags.ParFlags.fishDelay : 0ll); - /* If we still have no work we need to send a FISH to get a spark - from another PE - */ - if (EMPTY_RUN_QUEUE()) { /* =8-[ no local sparks => look for work on other PEs */ /* * We really have absolutely no work. Send out a fish @@ -755,48 +1322,106 @@ schedule( StgMainThread *mainThread USED_WHEN_RTS_SUPPORTS_THREADS, * we're hoping to see. (Of course, we still have to * respond to other types of messages.) */ - TIME now = msTime() /*CURRENT_TIME*/; + rtsTime now = msTime() /*CURRENT_TIME*/; IF_PAR_DEBUG(verbose, debugBelch("-- now=%ld\n", now)); - IF_PAR_DEBUG(verbose, - if (outstandingFishes < RtsFlags.ParFlags.maxFishes && - (last_fish_arrived_at!=0 && - last_fish_arrived_at+RtsFlags.ParFlags.fishDelay > now)) { - debugBelch("--$$ delaying FISH until %ld (last fish %ld, delay %ld, now %ld)\n", - last_fish_arrived_at+RtsFlags.ParFlags.fishDelay, - last_fish_arrived_at, - RtsFlags.ParFlags.fishDelay, now); - }); - + IF_PAR_DEBUG(fish, // verbose, + if (outstandingFishes < RtsFlags.ParFlags.maxFishes && + (last_fish_arrived_at!=0 && + last_fish_arrived_at+delay > now)) { + debugBelch("--$$ <%llu> delaying FISH until %llu (last fish %llu, delay %llu)\n", + now, last_fish_arrived_at+delay, + last_fish_arrived_at, + delay); + }); + if (outstandingFishes < RtsFlags.ParFlags.maxFishes && - (last_fish_arrived_at==0 || - (last_fish_arrived_at+RtsFlags.ParFlags.fishDelay <= now))) { - /* outstandingFishes is set in sendFish, processFish; - avoid flooding system with fishes via delay */ - pe = choosePE(); - sendFish(pe, mytid, NEW_FISH_AGE, NEW_FISH_HISTORY, - NEW_FISH_HUNGER); - - // Global statistics: count no. of fishes - if (RtsFlags.ParFlags.ParStats.Global && - RtsFlags.GcFlags.giveStats > NO_GC_STATS) { - globalParStats.tot_fish_mess++; - } - } - - receivedFinish = processMessages(); - goto next_thread; + advisory_thread_count < RtsFlags.ParFlags.maxThreads) { // send a FISH, but when? + if (last_fish_arrived_at==0 || + (last_fish_arrived_at+delay <= now)) { // send FISH now! + /* outstandingFishes is set in sendFish, processFish; + avoid flooding system with fishes via delay */ + next_fish_to_send_at = 0; + } else { + /* ToDo: this should be done in the main scheduling loop to avoid the + busy wait here; not so bad if fish delay is very small */ + int iq = 0; // DEBUGGING -- HWL + next_fish_to_send_at = last_fish_arrived_at+delay; // remember when to send + /* send a fish when ready, but process messages that arrive in the meantime */ + do { + if (PacketsWaiting()) { + iq++; // DEBUGGING + *receivedFinish = processMessages(); } - } else if (PacketsWaiting()) { /* Look for incoming messages */ - receivedFinish = processMessages(); - } + now = msTime(); + } while (!*receivedFinish || now sent delayed fish (%d processMessages); active/total threads=%d/%d\n",now,iq,run_queue_len(),advisory_thread_count)); - /* Now we are sure that we have some work available */ - ASSERT(run_queue_hd != END_TSO_QUEUE); + } - /* Take a thread from the run queue, if we have work */ - POP_RUN_QUEUE(t); // take_off_run_queue(END_TSO_QUEUE); - IF_DEBUG(sanity,checkTSO(t)); + // JB: IMHO, this should all be hidden inside sendFish(...) + /* pe = choosePE(); + sendFish(pe, thisPE, NEW_FISH_AGE, NEW_FISH_HISTORY, + NEW_FISH_HUNGER); + + // Global statistics: count no. of fishes + if (RtsFlags.ParFlags.ParStats.Global && + RtsFlags.GcFlags.giveStats > NO_GC_STATS) { + globalParStats.tot_fish_mess++; + } + */ + + /* delayed fishes must have been sent by now! */ + next_fish_to_send_at = 0; + } + + *receivedFinish = processMessages(); +# endif /* SPARKS */ + + return rtsFalse; + /* NB: this function always returns rtsFalse, meaning the scheduler + loop continues with the next iteration; + rationale: + return code means success in finding work; we enter this function + if there is no local work, thus have to send a fish which takes + time until it arrives with work; in the meantime we should process + messages in the main loop; + */ +} +#endif // PARALLEL_HASKELL + +/* ---------------------------------------------------------------------------- + * PAR/GRAN: Report stats & debugging info(?) + * ------------------------------------------------------------------------- */ + +#if defined(PAR) || defined(GRAN) +static void +scheduleGranParReport(void) +{ + ASSERT(run_queue_hd != END_TSO_QUEUE); + + /* Take a thread from the run queue, if we have work */ + POP_RUN_QUEUE(t); // take_off_run_queue(END_TSO_QUEUE); + + /* If this TSO has got its outport closed in the meantime, + * it mustn't be run. Instead, we have to clean it up as if it was finished. + * It has to be marked as TH_DEAD for this purpose. + * If it is TH_TERM instead, it is supposed to have finished in the normal way. + +JB: TODO: investigate wether state change field could be nuked + entirely and replaced by the normal tso state (whatnext + field). All we want to do is to kill tsos from outside. + */ /* ToDo: write something to the log-file if (RTSflags.ParFlags.granSimStats && !sameThread) @@ -805,25 +1430,20 @@ schedule( StgMainThread *mainThread USED_WHEN_RTS_SUPPORTS_THREADS, CurrentTSO = t; */ /* the spark pool for the current PE */ - pool = &(MainRegTable.rSparks); // generalise to cap = &MainRegTable + pool = &(cap.r.rSparks); // cap = (old) MainCap IF_DEBUG(scheduler, debugBelch("--=^ %d threads, %d sparks on [%#x]\n", run_queue_len(), spark_queue_len(pool), CURRENT_PROC)); -# if 1 - if (0 && RtsFlags.ParFlags.ParStats.Full && - t && LastTSO && t->id != LastTSO->id && - LastTSO->why_blocked == NotBlocked && - LastTSO->what_next != ThreadComplete) { - // if previously scheduled TSO not blocked we have to record the context switch - DumpVeryRawGranEvent(TimeOfLastYield, CURRENT_PROC, CURRENT_PROC, - GR_DESCHEDULE, LastTSO, (StgClosure *)NULL, 0, 0); - } + IF_PAR_DEBUG(fish, + debugBelch("--=^ %d threads, %d sparks on [%#x]\n", + run_queue_len(), spark_queue_len(pool), CURRENT_PROC)); if (RtsFlags.ParFlags.ParStats.Full && - (emitSchedule /* forced emit */ || - (t && LastTSO && t->id != LastTSO->id))) { + (t->par.sparkname != (StgInt)0) && // only log spark generated threads + (emitSchedule || // forced emit + (t && LastTSO && t->id != LastTSO->id))) { /* we are running a different TSO, so write a schedule event to log file NB: If we use fair scheduling we also have to write a deschedule @@ -831,137 +1451,23 @@ schedule( StgMainThread *mainThread USED_WHEN_RTS_SUPPORTS_THREADS, previous tso has blocked whenever we switch to another tso, so we don't need it in GUM for now */ + IF_PAR_DEBUG(fish, // schedule, + debugBelch("____ scheduling spark generated thread %d (%lx) (%lx) via a forced emit\n",t->id,t,t->par.sparkname)); + DumpRawGranEvent(CURRENT_PROC, CURRENT_PROC, GR_SCHEDULE, t, (StgClosure *)NULL, 0, 0); emitSchedule = rtsFalse; } - -# endif -#else /* !GRAN && !PAR */ - - // grab a thread from the run queue - ASSERT(run_queue_hd != END_TSO_QUEUE); - POP_RUN_QUEUE(t); - - // Sanity check the thread we're about to run. This can be - // expensive if there is lots of thread switching going on... - IF_DEBUG(sanity,checkTSO(t)); -#endif - -#ifdef THREADED_RTS - { - StgMainThread *m = t->main; - - 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; - } - } - } +} #endif - cap->r.rCurrentTSO = t; - - /* context switches are now 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))) - 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])); - -#ifdef PROFILING - startHeapProfTimer(); -#endif - - /* +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ */ - /* Run the current thread - */ - prev_what_next = t->what_next; - - errno = t->saved_errno; - in_haskell = rtsTrue; - - 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); - break; - - case ThreadInterpret: - ret = interpretBCO(cap); - break; - - default: - barf("schedule: invalid what_next field"); - } - - in_haskell = rtsFalse; - - // The TSO might have moved, so find the new location: - t = cap->r.rCurrentTSO; - - // And save the current errno in this thread. - t->saved_errno = errno; +/* ---------------------------------------------------------------------------- + * After running a thread... + * ------------------------------------------------------------------------- */ - /* +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ */ - - /* Costs for the scheduler are assigned to CCS_SYSTEM */ -#ifdef PROFILING - stopHeapProfTimer(); - CCCS = CCS_SYSTEM; -#endif - - ACQUIRE_LOCK(&sched_mutex); - -#ifdef RTS_SUPPORTS_THREADS - IF_DEBUG(scheduler,debugBelch("sched (task %p): ", osThreadId());); -#elif !defined(GRAN) && !defined(PAR) - IF_DEBUG(scheduler,debugBelch("sched: ");); -#endif - +static void +schedulePostRunThread(void) +{ #if defined(PAR) /* HACK 675: if the last thread didn't yield, make sure to print a SCHEDULE event to the log file when StgRunning the next thread, even @@ -970,302 +1476,403 @@ run_thread: TimeOfLastYield = CURRENT_TIME; #endif - switch (ret) { + /* some statistics gathering in the parallel case */ + +#if defined(GRAN) || defined(PAR) || defined(EDEN) + switch (ret) { case HeapOverflow: -#if defined(GRAN) +# if defined(GRAN) IF_DEBUG(gran, DumpGranEvent(GR_DESCHEDULE, t)); globalGranStats.tot_heapover++; -#elif defined(PAR) +# elif defined(PAR) globalParStats.tot_heapover++; -#endif +# endif + break; - // did the task ask for a large block? - if (cap->r.rHpAlloc > BLOCK_SIZE) { - // if so, get one and push it on the front of the nursery. - bdescr *bd; - nat blocks; - - blocks = (nat)BLOCK_ROUND_UP(cap->r.rHpAlloc) / BLOCK_SIZE; + case StackOverflow: +# if defined(GRAN) + IF_DEBUG(gran, + DumpGranEvent(GR_DESCHEDULE, t)); + globalGranStats.tot_stackover++; +# elif defined(PAR) + // IF_DEBUG(par, + // DumpGranEvent(GR_DESCHEDULE, t); + globalParStats.tot_stackover++; +# endif + break; - IF_DEBUG(scheduler,debugBelch("--<< thread %ld (%s) stopped: requesting a large block (size %d)\n", - (long)t->id, whatNext_strs[t->what_next], blocks)); + case ThreadYielding: +# if defined(GRAN) + IF_DEBUG(gran, + DumpGranEvent(GR_DESCHEDULE, t)); + globalGranStats.tot_yields++; +# elif defined(PAR) + // IF_DEBUG(par, + // DumpGranEvent(GR_DESCHEDULE, t); + globalParStats.tot_yields++; +# endif + break; - // 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) { + case ThreadBlocked: +# if defined(GRAN) + IF_DEBUG(scheduler, + debugBelch("--<< thread %ld (%p; %s) stopped, blocking on node %p [PE %d] with BQ: ", + t->id, t, whatNext_strs[t->what_next], t->block_info.closure, + (t->block_info.closure==(StgClosure*)NULL ? 99 : where_is(t->block_info.closure))); + if (t->block_info.closure!=(StgClosure*)NULL) + print_bq(t->block_info.closure); + debugBelch("\n")); + + // ??? needed; should emit block before + IF_DEBUG(gran, + DumpGranEvent(GR_DESCHEDULE, t)); + prune_eventq(t, (StgClosure *)NULL); // prune ContinueThreads for t + /* + ngoq Dogh! + ASSERT(procStatus[CurrentProc]==Busy || + ((procStatus[CurrentProc]==Fetching) && + (t->block_info.closure!=(StgClosure*)NULL))); + if (run_queue_hds[CurrentProc] == END_TSO_QUEUE && + !(!RtsFlags.GranFlags.DoAsyncFetch && + procStatus[CurrentProc]==Fetching)) + procStatus[CurrentProc] = Idle; + */ +# elif defined(PAR) +//++PAR++ blockThread() writes the event (change?) +# endif + break; - alloc_blocks += blocks; - bd = allocGroup( blocks ); + case ThreadFinished: + break; - // link the new group into the list - bd->link = cap->r.rCurrentNursery; - bd->u.back = cap->r.rCurrentNursery->u.back; - if (cap->r.rCurrentNursery->u.back != NULL) { - cap->r.rCurrentNursery->u.back->link = bd; - } else { - ASSERT(g0s0->blocks == cap->r.rCurrentNursery && - g0s0->blocks == cap->r.rNursery); - cap->r.rNursery = g0s0->blocks = bd; - } - cap->r.rCurrentNursery->u.back = bd; - - // initialise it as a nursery block. We initialise the - // step, gen_no, and flags field of *every* sub-block in - // this large block, because this is easier than making - // sure that we always find the block head of a large - // block whenever we call Bdescr() (eg. evacuate() and - // isAlive() in the GC would both have to do this, at - // least). - { - bdescr *x; - for (x = bd; x < bd + blocks; x++) { - x->step = g0s0; - x->gen_no = 0; - x->flags = 0; - } - } + default: + barf("parGlobalStats: unknown return code"); + break; + } +#endif +} - // 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); - - // now update the nursery to point to the new block - cap->r.rCurrentNursery = bd; - - // we might be unlucky and have another thread get on the - // 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); - break; - } - } +/* ----------------------------------------------------------------------------- + * Handle a thread that returned to the scheduler with ThreadHeepOverflow + * -------------------------------------------------------------------------- */ - /* 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(PAR) - /* Currently we emit a DESCHEDULE event before GC in GUM. - ToDo: either add separate event to distinguish SYSTEM time from rest - or just nuke this DESCHEDULE (and the following SCHEDULE) */ - if (0 && RtsFlags.ParFlags.ParStats.Full) { - DumpRawGranEvent(CURRENT_PROC, CURRENT_PROC, - GR_DESCHEDULE, t, (StgClosure *)NULL, 0, 0); - emitSchedule = rtsTrue; - } +static rtsBool +scheduleHandleHeapOverflow( Capability *cap, StgTSO *t ) +{ + // did the task ask for a large block? + if (cap->r.rHpAlloc > BLOCK_SIZE) { + // if so, get one and push it on the front of the nursery. + bdescr *bd; + lnat blocks; + + blocks = (lnat)BLOCK_ROUND_UP(cap->r.rHpAlloc) / BLOCK_SIZE; + + IF_DEBUG(scheduler, + 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 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. + + 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; + bd->u.back = cap->r.rCurrentNursery->u.back; + if (cap->r.rCurrentNursery->u.back != NULL) { + cap->r.rCurrentNursery->u.back->link = bd; + } else { +#if !defined(THREADED_RTS) + ASSERT(g0s0->blocks == cap->r.rCurrentNursery && + g0s0 == cap->r.rNursery); #endif - - ready_to_gc = rtsTrue; - PUSH_ON_RUN_QUEUE(t); - /* actual GC is done at the end of the while loop */ - break; - - case StackOverflow: -#if defined(GRAN) - IF_DEBUG(gran, - DumpGranEvent(GR_DESCHEDULE, t)); - globalGranStats.tot_stackover++; -#elif defined(PAR) - // IF_DEBUG(par, - // DumpGranEvent(GR_DESCHEDULE, t); - globalParStats.tot_stackover++; + cap->r.rNursery->blocks = bd; + } + cap->r.rCurrentNursery->u.back = bd; + + // initialise it as a nursery block. We initialise the + // step, gen_no, and flags field of *every* sub-block in + // this large block, because this is easier than making + // sure that we always find the block head of a large + // block whenever we call Bdescr() (eg. evacuate() and + // isAlive() in the GC would both have to do this, at + // least). + { + bdescr *x; + for (x = bd; x < bd + blocks; x++) { + x->step = cap->r.rNursery; + x->gen_no = 0; + x->flags = 0; + } + } + + // This assert can be a killer if the app is doing lots + // of large block allocations. + IF_DEBUG(sanity, checkNurserySanity(cap->r.rNursery)); + + // now update the nursery to point to the new block + cap->r.rCurrentNursery = bd; + + // we might be unlucky and have another thread get on the + // run queue before us and steal the large block, but in that + // case the thread will just end up requesting another large + // block. + pushOnRunQueue(cap,t); + return rtsFalse; /* not actually GC'ing */ + } + } + + IF_DEBUG(scheduler, + debugBelch("--<< thread %ld (%s) stopped: HeapOverflow\n", + (long)t->id, whatNext_strs[t->what_next])); +#if defined(GRAN) + ASSERT(!is_on_queue(t,CurrentProc)); +#elif defined(PARALLEL_HASKELL) + /* Currently we emit a DESCHEDULE event before GC in GUM. + ToDo: either add separate event to distinguish SYSTEM time from rest + or just nuke this DESCHEDULE (and the following SCHEDULE) */ + if (0 && RtsFlags.ParFlags.ParStats.Full) { + DumpRawGranEvent(CURRENT_PROC, CURRENT_PROC, + GR_DESCHEDULE, t, (StgClosure *)NULL, 0, 0); + emitSchedule = rtsTrue; + } #endif - 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); - { + + 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 + * -------------------------------------------------------------------------- */ + +static void +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. + */ + { /* 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); - } - break; + pushOnRunQueue(cap,new_t); + } +} - case ThreadYielding: - // Reset the context switch flag. We don't do this just before - // running the thread, because that would mean we would lose ticks - // during GC, which can lead to unfair scheduling (a thread hogs - // the CPU because the tick always arrives during GC). This way - // penalises threads that do a lot of allocation, but that seems - // better than the alternative. - context_switch = 0; +/* ----------------------------------------------------------------------------- + * Handle a thread that returned to the scheduler with ThreadYielding + * -------------------------------------------------------------------------- */ +static rtsBool +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 + // during GC, which can lead to unfair scheduling (a thread hogs + // the CPU because the tick always arrives during GC). This way + // penalises threads that do a lot of allocation, but that seems + // better than the alternative. + context_switch = 0; + + /* put the thread back on the run queue. Then, if we're ready to + * GC, check whether this is the last task to stop. If so, wake + * up the GC thread. getThread will block during a GC until the + * GC is finished. + */ + IF_DEBUG(scheduler, + if (t->what_next != prev_what_next) { + debugBelch("--<< thread %ld (%s) stopped to switch evaluators\n", + (long)t->id, whatNext_strs[t->what_next]); + } else { + debugBelch("--<< thread %ld (%s) stopped, yielding\n", + (long)t->id, whatNext_strs[t->what_next]); + } + ); + + IF_DEBUG(sanity, + //debugBelch("&& Doing sanity check on yielding TSO %ld.", t->id); + checkTSO(t)); + ASSERT(t->link == END_TSO_QUEUE); + + // Shortcut if we're just switching evaluators: don't bother + // doing stack squeezing (which can be expensive), just run the + // thread. + if (t->what_next != prev_what_next) { + return rtsTrue; + } + #if defined(GRAN) - IF_DEBUG(gran, - DumpGranEvent(GR_DESCHEDULE, t)); - globalGranStats.tot_yields++; -#elif defined(PAR) - // IF_DEBUG(par, - // DumpGranEvent(GR_DESCHEDULE, t); - globalParStats.tot_yields++; + ASSERT(!is_on_queue(t,CurrentProc)); + + IF_DEBUG(sanity, + //debugBelch("&& Doing sanity check on all ThreadQueues (and their TSOs)."); + checkThreadQsSanity(rtsTrue)); + #endif - /* put the thread back on the run queue. Then, if we're ready to - * GC, check whether this is the last task to stop. If so, wake - * up the GC thread. getThread will block during a GC until the - * GC is finished. - */ - IF_DEBUG(scheduler, - if (t->what_next != prev_what_next) { - debugBelch("--<< thread %ld (%s) stopped to switch evaluators\n", - (long)t->id, whatNext_strs[t->what_next]); - } else { - debugBelch("--<< thread %ld (%s) stopped, yielding\n", - (long)t->id, whatNext_strs[t->what_next]); - } - ); - - IF_DEBUG(sanity, - //debugBelch("&& Doing sanity check on yielding TSO %ld.", t->id); - checkTSO(t)); - ASSERT(t->link == END_TSO_QUEUE); - - // Shortcut if we're just switching evaluators: don't bother - // doing stack squeezing (which can be expensive), just run the - // thread. - if (t->what_next != prev_what_next) { - goto run_thread; - } - threadPaused(t); + addToRunQueue(cap,t); #if defined(GRAN) - ASSERT(!is_on_queue(t,CurrentProc)); - - IF_DEBUG(sanity, - //debugBelch("&& Doing sanity check on all ThreadQueues (and their TSOs)."); - checkThreadQsSanity(rtsTrue)); -#endif - -#if defined(PAR) - if (RtsFlags.ParFlags.doFairScheduling) { - /* this does round-robin scheduling; good for concurrency */ - APPEND_TO_RUN_QUEUE(t); - } else { - /* this does unfair scheduling; good for parallelism */ - PUSH_ON_RUN_QUEUE(t); - } -#else - // this does round-robin scheduling; good for concurrency - APPEND_TO_RUN_QUEUE(t); + /* add a ContinueThread event to actually process the thread */ + new_event(CurrentProc, CurrentProc, CurrentTime[CurrentProc], + ContinueThread, + t, (StgClosure*)NULL, (rtsSpark*)NULL); + IF_GRAN_DEBUG(bq, + debugBelch("GRAN: eventq and runnableq after adding yielded thread to queue again:\n"); + G_EVENTQ(0); + G_CURR_THREADQ(0)); #endif + return rtsFalse; +} -#if defined(GRAN) - /* add a ContinueThread event to actually process the thread */ - new_event(CurrentProc, CurrentProc, CurrentTime[CurrentProc], - ContinueThread, - t, (StgClosure*)NULL, (rtsSpark*)NULL); - IF_GRAN_DEBUG(bq, - debugBelch("GRAN: eventq and runnableq after adding yielded thread to queue again:\n"); - G_EVENTQ(0); - G_CURR_THREADQ(0)); -#endif /* GRAN */ - break; +/* ----------------------------------------------------------------------------- + * Handle a thread that returned to the scheduler with ThreadBlocked + * -------------------------------------------------------------------------- */ - case ThreadBlocked: +static void +scheduleHandleThreadBlocked( StgTSO *t +#if !defined(GRAN) && !defined(DEBUG) + STG_UNUSED +#endif + ) +{ #if defined(GRAN) - IF_DEBUG(scheduler, - debugBelch("--<< thread %ld (%p; %s) stopped, blocking on node %p [PE %d] with BQ: \n", - t->id, t, whatNext_strs[t->what_next], t->block_info.closure, (t->block_info.closure==(StgClosure*)NULL ? 99 : where_is(t->block_info.closure))); - if (t->block_info.closure!=(StgClosure*)NULL) print_bq(t->block_info.closure)); - - // ??? needed; should emit block before - IF_DEBUG(gran, - DumpGranEvent(GR_DESCHEDULE, t)); - prune_eventq(t, (StgClosure *)NULL); // prune ContinueThreads for t - /* - ngoq Dogh! + IF_DEBUG(scheduler, + debugBelch("--<< thread %ld (%p; %s) stopped, blocking on node %p [PE %d] with BQ: \n", + t->id, t, whatNext_strs[t->what_next], t->block_info.closure, (t->block_info.closure==(StgClosure*)NULL ? 99 : where_is(t->block_info.closure))); + if (t->block_info.closure!=(StgClosure*)NULL) print_bq(t->block_info.closure)); + + // ??? needed; should emit block before + IF_DEBUG(gran, + DumpGranEvent(GR_DESCHEDULE, t)); + prune_eventq(t, (StgClosure *)NULL); // prune ContinueThreads for t + /* + ngoq Dogh! ASSERT(procStatus[CurrentProc]==Busy || - ((procStatus[CurrentProc]==Fetching) && - (t->block_info.closure!=(StgClosure*)NULL))); + ((procStatus[CurrentProc]==Fetching) && + (t->block_info.closure!=(StgClosure*)NULL))); if (run_queue_hds[CurrentProc] == END_TSO_QUEUE && - !(!RtsFlags.GranFlags.DoAsyncFetch && - procStatus[CurrentProc]==Fetching)) - procStatus[CurrentProc] = Idle; - */ + !(!RtsFlags.GranFlags.DoAsyncFetch && + procStatus[CurrentProc]==Fetching)) + procStatus[CurrentProc] = Idle; + */ #elif defined(PAR) - IF_DEBUG(scheduler, - debugBelch("--<< thread %ld (%p; %s) stopped, blocking on node %p with BQ: \n", - t->id, t, whatNext_strs[t->what_next], t->block_info.closure)); - IF_PAR_DEBUG(bq, + IF_DEBUG(scheduler, + debugBelch("--<< thread %ld (%p; %s) stopped, blocking on node %p with BQ: \n", + t->id, t, whatNext_strs[t->what_next], t->block_info.closure)); + IF_PAR_DEBUG(bq, + + if (t->block_info.closure!=(StgClosure*)NULL) + print_bq(t->block_info.closure)); + + /* Send a fetch (if BlockedOnGA) and dump event to log file */ + blockThread(t); + + /* whatever we schedule next, we must log that schedule */ + emitSchedule = rtsTrue; + +#else /* !GRAN */ - if (t->block_info.closure!=(StgClosure*)NULL) - print_bq(t->block_info.closure)); + // 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. - /* Send a fetch (if BlockedOnGA) and dump event to log file */ - blockThread(t); +#if !defined(THREADED_RTS) + ASSERT(t->why_blocked != NotBlocked); + // This might not be true under THREADED_RTS: 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 - /* whatever we schedule next, we must log that schedule */ - emitSchedule = rtsTrue; + IF_DEBUG(scheduler, + debugBelch("--<< thread %d (%s) stopped: ", + t->id, whatNext_strs[t->what_next]); + printThreadBlockage(t); + debugBelch("\n")); + + /* Only for dumping event to log file + ToDo: do I need this in GranSim, too? + blockThread(t); + */ +#endif +} -#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. - */ - ASSERT(t->why_blocked != NotBlocked); - IF_DEBUG(scheduler, - debugBelch("--<< thread %d (%s) stopped: ", - t->id, whatNext_strs[t->what_next]); - printThreadBlockage(t); - debugBelch("\n")); +/* ----------------------------------------------------------------------------- + * Handle a thread that returned to the scheduler with ThreadFinished + * -------------------------------------------------------------------------- */ - /* Only for dumping event to log file - ToDo: do I need this in GranSim, too? - blockThread(t); - */ -#endif - threadPaused(t); - break; +static rtsBool +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. + * + * We also end up here if the thread kills itself with an + * uncaught exception, see Exception.cmm. + */ + IF_DEBUG(scheduler,debugBelch("--++ thread %d (%s) finished\n", + t->id, whatNext_strs[t->what_next])); - case ThreadFinished: - /* Need to check whether this was a main thread, and if so, signal - * the task that started it with the return value. If we have no - * more main threads, we probably need to stop all the tasks until - * we get a new one. - */ - /* We also end up here if the thread kills itself with an - * uncaught exception, see Exception.hc. - */ - IF_DEBUG(scheduler,debugBelch("--++ thread %d (%s) finished\n", - t->id, whatNext_strs[t->what_next])); #if defined(GRAN) endThread(t, CurrentProc); // clean-up the thread -#elif defined(PAR) +#elif defined(PARALLEL_HASKELL) /* For now all are advisory -- HWL */ //if(t->priority==AdvisoryPriority) ?? - advisory_thread_count--; + advisory_thread_count--; // JB: Caution with this counter, buggy! -# ifdef DIST +# if defined(DIST) if(t->dist.priority==RevalPriority) FinishReval(t); # endif - + +# if defined(EDENOLD) + // the thread could still have an outport... (BUG) + if (t->eden.outport != -1) { + // delete the outport for the tso which has finished... + IF_PAR_DEBUG(eden_ports, + debugBelch("WARNING: Scheduler removes outport %d for TSO %d.\n", + t->eden.outport, t->id)); + deleteOPT(t); + } + // thread still in the process (HEAVY BUG! since outport has just been closed...) + if (t->eden.epid != -1) { + IF_PAR_DEBUG(eden_ports, + debugBelch("WARNING: Scheduler removes TSO %d from process %d .\n", + t->id, t->eden.epid)); + removeTSOfromProcess(t); + } +# endif + +# if defined(PAR) if (RtsFlags.ParFlags.ParStats.Full && !RtsFlags.ParFlags.ParStats.Suppressed) DumpEndEvent(CURRENT_PROC, t, rtsFalse /* not mandatory */); -#endif + + // t->par only contains statistics: left out for now... + IF_PAR_DEBUG(fish, + debugBelch("**** end thread: ended sparked thread %d (%lx); sparkname: %lx\n", + t->id,t,t->par.sparkname)); +# endif +#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 @@ -1273,139 +1880,226 @@ run_thread: // 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 (was_interrupted) { - mainThread->stat = Interrupted; + if (sched_state >= SCHED_INTERRUPTING) { + 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; + 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 - break; + return rtsFalse; +} - default: - barf("schedule: invalid thread return code %d", (int)ret); - } +/* ----------------------------------------------------------------------------- + * Perform a heap census, if PROFILING + * -------------------------------------------------------------------------- */ -#ifdef PROFILING +static rtsBool +scheduleDoHeapProfile( rtsBool ready_to_gc STG_UNUSED ) +{ +#if defined(PROFILING) // When we have +RTS -i0 and we're heap profiling, do a census at // every GC. This lets us get repeatable runs for debugging. if (performHeapProfile || (RtsFlags.ProfFlags.profileInterval==0 && RtsFlags.ProfFlags.doHeapProfile && ready_to_gc)) { + + // checking black holes is necessary before GC, otherwise + // there may be threads that are unreachable except by the + // blackhole queue, which the GC will consider to be + // deadlocked. + scheduleCheckBlackHoles(&MainCapability); + + IF_DEBUG(scheduler, sched_belch("garbage collecting before heap census")); GarbageCollect(GetRoots, rtsTrue); + + IF_DEBUG(scheduler, sched_belch("performing heap census")); heapCensus(); + performHeapProfile = rtsFalse; - ready_to_gc = rtsFalse; // we already GC'd + return rtsTrue; // true <=> we already GC'd } #endif + return rtsFalse; +} - if (ready_to_gc) { - /* 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); - +/* ----------------------------------------------------------------------------- + * Perform a garbage collection if necessary + * -------------------------------------------------------------------------- */ + +static Capability * +scheduleDoGC (Capability *cap, Task *task USED_IF_THREADS, + rtsBool force_major, void (*get_roots)(evac_fn)) +{ + StgTSO *t; +#ifdef THREADED_RTS + static volatile StgWord waiting_for_gc; + rtsBool was_waiting; + nat i; +#endif + +#ifdef THREADED_RTS + // In order to GC, there must be no threads running Haskell code. + // Therefore, the GC thread needs to hold *all* the capabilities, + // and release them after the GC has completed. + // + // This seems to be the simplest way: previous attempts involved + // making all the threads with capabilities give up their + // capabilities and sleep except for the *last* one, which + // actually did the GC. But it's quite hard to arrange for all + // the other tasks to sleep and stay asleep. + // + + was_waiting = cas(&waiting_for_gc, 0, 1); + if (was_waiting) { + do { + IF_DEBUG(scheduler, sched_belch("someone else is trying to GC...")); + if (cap) yieldCapability(&cap,task); + } while (waiting_for_gc); + return cap; // NOTE: task->cap might have changed here + } + + 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. + */ + { + 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_(&capabilities[0], 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: + if (cap) 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_DEBUG(scheduler,sched_belch("doing GC")); + /* + * We now have all the capabilities; if we're in an interrupting + * state, then we should take the opportunity to delete all the + * threads in the system. + */ + if (sched_state >= SCHED_INTERRUPTING) { + deleteAllThreads(&capabilities[0]); + sched_state = SCHED_INTERRUPTED; + } + + /* 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(THREADED_RTS) + IF_DEBUG(scheduler,sched_belch("doing GC")); #endif - GarbageCollect(GetRoots,rtsFalse); - ready_to_gc = rtsFalse; -#if defined(GRAN) - /* add a ContinueThread event to continue execution of current thread */ - new_event(CurrentProc, CurrentProc, CurrentTime[CurrentProc], - ContinueThread, - t, (StgClosure*)NULL, (rtsSpark*)NULL); - IF_GRAN_DEBUG(bq, - debugBelch("GRAN: eventq and runnableq after Garbage collection:\n\n"); - G_EVENTQ(0); - G_CURR_THREADQ(0)); -#endif /* GRAN */ + GarbageCollect(get_roots, force_major); + +#if defined(THREADED_RTS) + // release our stash of capabilities. + for (i = 0; i < n_capabilities; i++) { + if (cap != &capabilities[i]) { + task->cap = &capabilities[i]; + releaseCapability(&capabilities[i]); + } + } + if (cap) { + task->cap = cap; + } else { + task->cap = NULL; } +#endif #if defined(GRAN) - next_thread: - IF_GRAN_DEBUG(unused, - print_eventq(EventHd)); - - event = get_next_event(); -#elif defined(PAR) - next_thread: - /* ToDo: wait for next message to arrive rather than busy wait */ + /* add a ContinueThread event to continue execution of current thread */ + new_event(CurrentProc, CurrentProc, CurrentTime[CurrentProc], + ContinueThread, + t, (StgClosure*)NULL, (rtsSpark*)NULL); + IF_GRAN_DEBUG(bq, + debugBelch("GRAN: eventq and runnableq after Garbage collection:\n\n"); + G_EVENTQ(0); + G_CURR_THREADQ(0)); #endif /* GRAN */ - } /* end of while(1) */ - - IF_PAR_DEBUG(verbose, - debugBelch("== Leaving schedule() after having received Finish\n")); + return cap; } /* --------------------------------------------------------------------------- @@ -1416,7 +2110,7 @@ run_thread: StgBool rtsSupportsBoundThreads(void) { -#ifdef THREADED_RTS +#if defined(THREADED_RTS) return rtsTrue; #else return rtsFalse; @@ -1428,10 +2122,10 @@ 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; } @@ -1440,13 +2134,13 @@ isThreadBound(StgTSO* tso USED_IN_THREADED_RTS) * Singleton fork(). Do not copy any running threads. * ------------------------------------------------------------------------- */ -#ifndef mingw32_HOST_OS +#if !defined(mingw32_HOST_OS) #define FORKPROCESS_PRIMOP_SUPPORTED #endif #ifdef FORKPROCESS_PRIMOP_SUPPORTED static void -deleteThreadImmediately(StgTSO *tso); +deleteThread_(Capability *cap, StgTSO *tso); #endif StgInt forkProcess(HsStablePtr *entry @@ -1456,76 +2150,112 @@ 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 defined(THREADED_RTS) + if (RtsFlags.ParFlags.nNodes > 1) { + errorBelch("forking not supported with +RTS -N greater than 1"); + stg_exit(EXIT_FAILURE); + } +#endif + + 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; + if (pid) { // parent + + // just return the pid + rts_unlock(cap); + return pid; + + } else { // child + + // Now, all OS threads except the thread that forked are + // stopped. We need to stop all Haskell threads, including + // those involved in foreign calls. Also we need to delete + // all Tasks, because they correspond to OS threads that are + // now gone. + + for (t = all_threads; t != END_TSO_QUEUE; t = next) { + if (t->what_next == ThreadRelocated) { + next = t->link; + } else { + next = t->global_link; + // don't allow threads to catch the ThreadKilled + // exception, but we do want to raiseAsync() because these + // threads may be evaluating thunks that we need later. + deleteThread_(cap,t); + } + } + + // Empty the run queue. It seems tempting to let all the + // killed threads stay on the run queue as zombies to be + // cleaned up later, but some of them correspond to bound + // threads for which the corresponding Task does not exist. + cap->run_queue_hd = END_TSO_QUEUE; + cap->run_queue_tl = END_TSO_QUEUE; + + // Any suspended C-calling Tasks are no more, their OS threads + // don't exist now: + cap->suspended_ccalling_tasks = NULL; + + // Empty the all_threads list. Otherwise, the garbage + // collector may attempt to resurrect some of these threads. + all_threads = END_TSO_QUEUE; + + // Wipe the task list, except the current Task. + 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); - // 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 defined(THREADED_RTS) + // Wipe our spare workers list, they no longer exist. New + // workers will be created if necessary. + 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 all the threads in the system * ------------------------------------------------------------------------- */ -void -deleteAllThreads ( void ) +static void +deleteAllThreads ( 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); + if (t->what_next == ThreadRelocated) { + next = t->link; + } else { + next = t->global_link; + deleteThread(cap,t); + } } // The run queue now contains a bunch of ThreadKilled threads. We @@ -1534,12 +2264,43 @@ deleteAllThreads ( void ) // 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. +#if !defined(THREADED_RTS) ASSERT(blocked_queue_hd == END_TSO_QUEUE); ASSERT(sleeping_queue == END_TSO_QUEUE); +#endif } -/* 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. @@ -1556,109 +2317,100 @@ 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); - -#if defined(RTS_SUPPORTS_THREADS) - /* 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)); -#endif + ACQUIRE_LOCK(&cap->lock); - in_haskell = rtsFalse; - RELEASE_LOCK(&sched_mutex); + suspendTask(cap,task); + cap->in_haskell = rtsFalse; + releaseCapability_(cap); - errno = saved_errno; - return tok; -} - -StgRegTable * -resumeThread( StgInt tok ) -{ - 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 + RELEASE_LOCK(&cap->lock); - /* 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; - } - } - 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; +#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("thread %d: leaving RTS", tso->id)); +#endif - cap->r.rCurrentTSO = tso; - in_haskell = rtsTrue; - RELEASE_LOCK(&sched_mutex); errno = saved_errno; - return &cap->r; + return task; } +StgRegTable * +resumeThread (void *task_) +{ + 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; + } + + /* Reset blocking status */ + tso->why_blocked = NotBlocked; + + cap->r.rCurrentTSO = tso; + cap->in_haskell = rtsTrue; + errno = saved_errno; + + /* We might have GC'd, mark the TSO dirty again */ + dirtyTSO(tso); -/* --------------------------------------------------------------------------- - * Static functions - * ------------------------------------------------------------------------ */ -static void unblockThread(StgTSO *tso); + IF_DEBUG(sanity, checkTSO(tso)); + + return &cap->r; +} /* --------------------------------------------------------------------------- * Comparing Thread ids. @@ -1724,171 +2476,176 @@ 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(PAR) - /* 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++; +#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++; #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->flags = TSO_DIRTY; + + tso->saved_errno = 0; + tso->bound = NULL; + tso->cap = cap; + + 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); -#elif defined(PAR) - if (RtsFlags.ParFlags.ParStats.Full) - DumpGranEvent(GR_STARTQ,tso); - /* HACk to avoid SCHEDULE - LastTSO = 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; */ #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)); -#elif defined(PAR) + 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++; -#elif defined(PAR) - // 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++; - } + 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++; + } #endif - + #if defined(GRAN) - IF_GRAN_DEBUG(pri, - sched_belch("==__ schedule: Created TSO %d (%p);", - CurrentProc, tso, tso->id)); -#elif defined(PAR) + 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)); + (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) @@ -1896,9 +2653,10 @@ createThread(nat size) all parallel thread creation calls should fall through the following routine. */ StgTSO * -createSparkThread(rtsSpark spark) +createThreadFromSpark(rtsSpark spark) { StgTSO *tso; ASSERT(spark != (rtsSpark)NULL); +// JB: TAKE CARE OF THIS COUNTER! BUGGY if (advisory_thread_count >= RtsFlags.ParFlags.maxThreads) { threadsIgnored++; barf("{createSparkThread}Daq ghuH: refusing to create another thread; no more than %d threads allowed (currently %d)", @@ -1914,8 +2672,8 @@ createSparkThread(rtsSpark spark) tso->priority = AdvisoryPriority; #endif pushClosure(tso,spark); - PUSH_ON_RUN_QUEUE(tso); - advisory_thread_count++; + addToRunQueue(tso); + advisory_thread_count++; // JB: TAKE CARE OF THIS COUNTER! BUGGY } return tso; } @@ -1925,7 +2683,7 @@ createSparkThread(rtsSpark spark) Turn a spark into a thread. ToDo: fix for SMP (needs to acquire SCHED_MUTEX!) */ -#if defined(PAR) +#if 0 StgTSO * activateSpark (rtsSpark spark) { @@ -1934,9 +2692,9 @@ activateSpark (rtsSpark spark) tso = createSparkThread(spark); if (RtsFlags.ParFlags.ParStats.Full) { //ASSERT(run_queue_hd == END_TSO_QUEUE); // I think ... - IF_PAR_DEBUG(verbose, - debugBelch("==^^ activateSpark: turning spark of closure %p (%s) into a thread\n", - (StgClosure *)spark, info_type((StgClosure *)spark))); + IF_PAR_DEBUG(verbose, + debugBelch("==^^ activateSpark: turning spark of closure %p (%s) into a thread\n", + (StgClosure *)spark, info_type((StgClosure *)spark))); } // ToDo: fwd info on local/global spark to thread -- HWL // tso->gran.exported = spark->exported; @@ -1947,95 +2705,109 @@ activateSpark (rtsSpark spark) } #endif -static SchedulerStatus waitThread_(/*out*/StgMainThread* m, - Capability *initialCapability - ); - - /* --------------------------------------------------------------------------- * 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_(StgTSO *tso) +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) +scheduleThreadOn(Capability *cap, StgWord cpu USED_IF_THREADS, StgTSO *tso) { - ACQUIRE_LOCK(&sched_mutex); - scheduleThread_(tso); - RELEASE_LOCK(&sched_mutex); +#if defined(THREADED_RTS) + tso->flags |= TSO_LOCKED; // we requested explicit affinity; don't + // move this thread from now on. + cpu %= RtsFlags.ParFlags.nNodes; + if (cpu == cap->no) { + appendToRunQueue(cap,tso); + } else { + Capability *target_cap = &capabilities[cpu]; + if (tso->bound) { + tso->bound->cap = target_cap; + } + tso->cap = target_cap; + wakeupThreadOnCapability(target_cap,tso); + } +#else + appendToRunQueue(cap,tso); +#endif } -#if defined(RTS_SUPPORTS_THREADS) -static Condition bound_cond_cache; -static int bound_cond_cache_full = 0; +Capability * +scheduleWaitThread (StgTSO* tso, /*[out]*/HaskellObj* ret, Capability *cap) +{ + Task *task; + + // 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; + tso->cap = cap; + + 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; + Capability *cap; - 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; + // See startWorkerTask(). + ACQUIRE_LOCK(&task->lock); + cap = task->cap; + RELEASE_LOCK(&task->lock); -#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 + // set the thread-local pointer to the Task: + taskEnter(task); - /* 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. + // schedule() runs without a lock. + cap = schedule(cap,task); - return waitThread_(m, initialCapability); + // On exit from schedule(), we have a Capability. + releaseCapability(cap); + taskStop(task); } +#endif /* --------------------------------------------------------------------------- * initScheduler() @@ -2051,116 +2823,101 @@ 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; blocked_queue_hds[i] = END_TSO_QUEUE; blocked_queue_tls[i] = END_TSO_QUEUE; ccalling_threadss[i] = END_TSO_QUEUE; + 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; 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; + sched_state = SCHED_RUNNING; 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); /* A capability holds the state a native thread needs in * order to execute STG code. At least one capability is - * floating around (only SMP builds have more than one). + * floating around (only THREADED_RTS builds have more than one). */ initCapabilities(); - -#if defined(RTS_SUPPORTS_THREADS) - /* start our haskell execution tasks */ - startTaskManager(0,taskStart); -#endif -#if /* defined(SMP) ||*/ defined(PAR) + initTaskManager(); + +#if defined(THREADED_RTS) || defined(PARALLEL_HASKELL) initSparkPools(); #endif +#if defined(THREADED_RTS) + /* + * 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); } void exitScheduler( void ) { -#if defined(RTS_SUPPORTS_THREADS) - stopTaskManager(); -#endif - shutting_down_scheduler = rtsTrue; -} - -/* ---------------------------------------------------------------------------- - 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)); + Task *task = NULL; -#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); +#if defined(THREADED_RTS) + ACQUIRE_LOCK(&sched_mutex); + task = newBoundTask(); + RELEASE_LOCK(&sched_mutex); #endif - stat = m->stat; + // If we haven't killed all the threads yet, do it now. + if (sched_state < SCHED_INTERRUPTED) { + sched_state = SCHED_INTERRUPTING; + scheduleDoGC(NULL,task,rtsFalse,GetRoots); + } + sched_state = SCHED_SHUTTING_DOWN; -#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); - } +#if defined(THREADED_RTS) + { + nat i; + + 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; } /* --------------------------------------------------------------------------- @@ -2182,55 +2939,62 @@ 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 (suspended_ccalling_threads != END_TSO_QUEUE) { - evac((StgClosure **)&suspended_ccalling_threads); - } + for (i = 0; i < n_capabilities; i++) { + cap = &capabilities[i]; + evac((StgClosure **)(void *)&cap->run_queue_hd); + evac((StgClosure **)(void *)&cap->run_queue_tl); +#if defined(THREADED_RTS) + evac((StgClosure **)(void *)&cap->wakeup_queue_hd); + evac((StgClosure **)(void *)&cap->wakeup_queue_tl); +#endif + for (task = cap->suspended_ccalling_tasks; task != NULL; + task=task->next) { + IF_DEBUG(scheduler,sched_belch("evac'ing suspended TSO %d", task->suspended_tso->id)); + evac((StgClosure **)(void *)&task->suspended_tso); + } -#if defined(PAR) || defined(GRAN) - markSparkQueue(evac); + } + + +#if !defined(THREADED_RTS) + evac((StgClosure **)(void *)&blocked_queue_hd); + evac((StgClosure **)(void *)&blocked_queue_tl); + evac((StgClosure **)(void *)&sleeping_queue); +#endif #endif + // evac((StgClosure **)&blackhole_queue); + +#if defined(THREADED_RTS) || 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 } @@ -2249,21 +3013,32 @@ GetRoots( evac_fn evac ) static void (*extra_roots)(evac_fn); +static void +performGC_(rtsBool force_major, void (*get_roots)(evac_fn)) +{ + Task *task = myTask(); + + if (task == NULL) { + ACQUIRE_LOCK(&sched_mutex); + task = newBoundTask(); + RELEASE_LOCK(&sched_mutex); + scheduleDoGC(NULL,task,force_major, get_roots); + boundTaskExiting(task); + } else { + scheduleDoGC(NULL,task,force_major, get_roots); + } +} + void performGC(void) { - /* Obligated to hold this lock upon entry */ - ACQUIRE_LOCK(&sched_mutex); - GarbageCollect(GetRoots,rtsFalse); - RELEASE_LOCK(&sched_mutex); + performGC_(rtsFalse, GetRoots); } void performMajorGC(void) { - ACQUIRE_LOCK(&sched_mutex); - GarbageCollect(GetRoots,rtsTrue); - RELEASE_LOCK(&sched_mutex); + performGC_(rtsTrue, GetRoots); } static void @@ -2276,10 +3051,8 @@ 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); + extra_roots = get_roots; + performGC_(rtsFalse, AllRoots); } /* ----------------------------------------------------------------------------- @@ -2292,9 +3065,10 @@ performGCWithRoots(void (*get_roots)(evac_fn)) -------------------------------------------------------------------------- */ static StgTSO * -threadStackOverflow(StgTSO *tso) +threadStackOverflow(Capability *cap, StgTSO *tso) { - nat new_stack_size, new_tso_size, stack_words; + nat new_stack_size, stack_words; + lnat new_tso_size; StgPtr new_sp; StgTSO *dest; @@ -2309,7 +3083,7 @@ 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; } @@ -2318,12 +3092,12 @@ threadStackOverflow(StgTSO *tso) * Finally round up so the TSO ends up as a whole number of blocks. */ new_stack_size = stg_min(tso->stack_size * 2, tso->max_stack_size); - new_tso_size = (nat)BLOCK_ROUND_UP(new_stack_size * sizeof(W_) + + new_tso_size = (lnat)BLOCK_ROUND_UP(new_stack_size * sizeof(W_) + TSO_STRUCT_SIZE)/sizeof(W_); 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); @@ -2374,7 +3148,7 @@ STATIC_INLINE void unblockCount ( StgBlockingQueueElement *bqe, StgClosure *node ) { } -#elif defined(PAR) +#elif defined(PARALLEL_HASKELL) STATIC_INLINE void unblockCount ( StgBlockingQueueElement *bqe, StgClosure *node ) { @@ -2384,7 +3158,7 @@ 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) { @@ -2401,15 +3175,15 @@ 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; @@ -2447,9 +3221,9 @@ unblockOneLocked(StgBlockingQueueElement *bqe, StgClosure *node) IF_DEBUG(scheduler,debugBelch("-- Waking up thread %ld (%p)\n", tso->id, tso)); } -#elif defined(PAR) -static StgBlockingQueueElement * -unblockOneLocked(StgBlockingQueueElement *bqe, StgClosure *node) +#elif defined(PARALLEL_HASKELL) +StgBlockingQueueElement * +unblockOne(StgBlockingQueueElement *bqe, StgClosure *node) { StgBlockingQueueElement *next; @@ -2484,7 +3258,7 @@ 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 @@ -2492,45 +3266,47 @@ unblockOneLocked(StgBlockingQueueElement *bqe, StgClosure *node) IF_PAR_DEBUG(bq, debugBelch(", %p (%s)\n", bqe, info_type((StgClosure*)bqe))); return next; } +#endif -#else /* !GRAN && !PAR */ -static StgTSO * -unblockOneLocked(StgTSO *tso) +StgTSO * +unblockOne(Capability *cap, StgTSO *tso) { StgTSO *next; ASSERT(get_itbl(tso)->type == TSO); ASSERT(tso->why_blocked != NotBlocked); + tso->why_blocked = NotBlocked; next = tso->link; tso->link = END_TSO_QUEUE; - APPEND_TO_RUN_QUEUE(tso); - threadRunnable(); - IF_DEBUG(scheduler,sched_belch("waking up thread %ld", (long)tso->id)); - return next; -} -#endif -#if defined(GRAN) || defined(PAR) -INLINE_ME StgBlockingQueueElement * -unblockOne(StgBlockingQueueElement *bqe, StgClosure *node) -{ - ACQUIRE_LOCK(&sched_mutex); - bqe = unblockOneLocked(bqe, node); - RELEASE_LOCK(&sched_mutex); - return bqe; -} +#if defined(THREADED_RTS) + if (tso->cap == cap || (!tsoLocked(tso) && RtsFlags.ParFlags.wakeupMigrate)) { + // We are waking up this thread on the current Capability, which + // might involve migrating it from the Capability it was last on. + if (tso->bound) { + ASSERT(tso->bound->cap == tso->cap); + tso->bound->cap = cap; + } + tso->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; + } else { + // we'll try to wake it up on the Capability it was last on. + wakeupThreadOnCapability(tso->cap, tso); + } #else -INLINE_ME StgTSO * -unblockOne(StgTSO *tso) -{ - ACQUIRE_LOCK(&sched_mutex); - tso = unblockOneLocked(tso); - RELEASE_LOCK(&sched_mutex); - return tso; -} + appendToRunQueue(cap,tso); + context_switch = 1; #endif + IF_DEBUG(scheduler,sched_belch("waking up thread %ld on cap %d", (long)tso->id, tso->cap->no)); + return next; +} + + #if defined(GRAN) void awakenBlockedQueue(StgBlockingQueueElement *q, StgClosure *node) @@ -2581,7 +3357,7 @@ 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 @@ -2613,14 +3389,12 @@ awakenBlockedQueue(StgBlockingQueueElement *q, StgClosure *node) debugBelch("## BQ Stats of %p: [%d entries] %s\n", node, len, (bqe!=END_BQ_QUEUE) ? "RBH" : "")); } -#elif defined(PAR) +#elif defined(PARALLEL_HASKELL) void 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)); @@ -2640,29 +3414,20 @@ 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 && !PAR */ - -void -awakenBlockedQueueNoLock(StgTSO *tso) -{ - while (tso != END_TSO_QUEUE) { - tso = unblockOneLocked(tso); - } -} +#else /* !GRAN && !PARALLEL_HASKELL */ 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 @@ -2674,8 +3439,11 @@ awakenBlockedQueue(StgTSO *tso) void interruptStgRts(void) { - interrupted = 1; + sched_state = SCHED_INTERRUPTING; context_switch = 1; +#if defined(THREADED_RTS) + prodAllCapabilities(); +#endif } /* ----------------------------------------------------------------------------- @@ -2686,7 +3454,7 @@ interruptStgRts(void) This has nothing to do with the UnblockThread event in GranSim. -- HWL -------------------------------------------------------------------------- */ -#if defined(GRAN) || defined(PAR) +#if defined(GRAN) || defined(PARALLEL_HASKELL) /* NB: only the type of the blocking queue is different in GranSim and GUM the operations on the queue-elements are the same @@ -2696,7 +3464,7 @@ interruptStgRts(void) */ static void -unblockThread(StgTSO *tso) +unblockThread(Capability *cap, StgTSO *tso) { StgBlockingQueueElement *t, **last; @@ -2799,6 +3567,12 @@ 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; } } @@ -2831,11 +3605,11 @@ 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; @@ -2875,12 +3649,9 @@ unblockThread(StgTSO *tso) } case BlockedOnBlackHole: - ASSERT(get_itbl(tso->block_info.closure)->type == BLACKHOLE_BQ); { - StgBlockingQueue *bq = (StgBlockingQueue *)(tso->block_info.closure); - - last = &bq->blocking_queue; - for (t = bq->blocking_queue; t != END_TSO_QUEUE; + last = &blackhole_queue; + for (t = blackhole_queue; t != END_TSO_QUEUE; last = &t->link, t = t->link) { if (t == tso) { *last = tso->link; @@ -2915,6 +3686,7 @@ unblockThread(StgTSO *tso) barf("unblockThread (Exception): TSO not found"); } +#if !defined(THREADED_RTS) case BlockedOnRead: case BlockedOnWrite: #if defined(mingw32_HOST_OS) @@ -2936,6 +3708,12 @@ 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; } } @@ -2955,21 +3733,77 @@ unblockThread(StgTSO *tso) } goto done; } - } - barf("unblockThread (delay): TSO not found"); + } + barf("unblockThread (delay): TSO not found"); + } +#endif + + default: + barf("unblockThread"); + } + + done: + tso->link = END_TSO_QUEUE; + tso->why_blocked = NotBlocked; + tso->block_info.closure = NULL; + appendToRunQueue(cap,tso); + + // We might have just migrated this TSO to our Capability: + if (tso->bound) { + tso->bound->cap = cap; + } + tso->cap = cap; +} +#endif + +/* ----------------------------------------------------------------------------- + * checkBlackHoles() + * + * Check the blackhole_queue for threads that can be woken up. We do + * this periodically: before every GC, and whenever the run queue is + * empty. + * + * An elegant solution might be to just wake up all the blocked + * threads with awakenBlockedQueue occasionally: they'll go back to + * sleep again if the object is still a BLACKHOLE. Unfortunately this + * doesn't give us a way to tell whether we've actually managed to + * wake up any threads, so we would be busy-waiting. + * + * -------------------------------------------------------------------------- */ + +static rtsBool +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 + prev = &blackhole_queue; + t = blackhole_queue; + while (t != END_TSO_QUEUE) { + ASSERT(t->why_blocked == BlockedOnBlackHole); + type = get_itbl(t->block_info.closure)->type; + if (type != BLACKHOLE && type != CAF_BLACKHOLE) { + 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 { + prev = &t->link; + t = t->link; + } } - default: - barf("unblockThread"); - } - - done: - tso->link = END_TSO_QUEUE; - tso->why_blocked = NotBlocked; - tso->block_info.closure = NULL; - APPEND_TO_RUN_QUEUE(tso); + return any_woke_up; } -#endif /* ----------------------------------------------------------------------------- * raiseAsync() @@ -3001,59 +3835,32 @@ unblockThread(StgTSO *tso) * 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 THREADED_RTS mode, this function is only safe if either + * (a) we hold all the Capabilities (eg. in GC, or if there is only + * one Capability), 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) { @@ -3064,7 +3871,10 @@ 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); + + // mark it dirty; we're about to change its stack. + dirtyTSO(tso); sp = tso->sp; @@ -3078,8 +3888,8 @@ 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" // @@ -3099,95 +3909,10 @@ 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; @@ -3198,7 +3923,7 @@ 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]; @@ -3218,9 +3943,7 @@ 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 @@ -3237,22 +3960,140 @@ 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)+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 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); + } + + // 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 +deleteThread_(Capability *cap, StgTSO *tso) +{ // for forkProcess only: + // like deleteThread(), but we delete threads in foreign calls, too. + + if (tso->why_blocked == BlockedOnCCall || + tso->why_blocked == BlockedOnCCall_NoUnblockExc) { + unblockOne(cap,tso); + tso->what_next = ThreadKilled; + } else { + deleteThread(cap,tso); } - barf("raiseAsync"); } +#endif /* ----------------------------------------------------------------------------- raiseExceptionHelper @@ -3263,9 +4104,10 @@ 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; // @@ -3274,7 +4116,7 @@ raiseExceptionHelper (StgTSO *tso, StgClosure *exception) // thunks which are currently under evaluataion. // - // + // OLD COMMENT (we don't have MIN_UPD_SIZE now): // LDV profiling: stg_raise_info has THUNK as its closure // type. Since a THUNK takes at least MIN_UPD_SIZE words in its // payload, MIN_UPD_SIZE is more approprate than 1. It seems that @@ -3302,11 +4144,11 @@ 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)+1); 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; @@ -3392,42 +4234,46 @@ 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 + cap = tso->cap; + + 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"); + } } - } } /* ---------------------------------------------------------------------------- @@ -3436,27 +4282,27 @@ resurrectThreads( StgTSO *threads ) * at the Haskell source code level, so enable outside of DEBUG. --sof 7/02] ------------------------------------------------------------------------- */ -static -void +#if DEBUG +static void printThreadBlockage(StgTSO *tso) { switch (tso->why_blocked) { case BlockedOnRead: - debugBelch("is blocked on read from fd %d", 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 %d", 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: - debugBelch("is blocked on proc (request: %d)", tso->block_info.async_result->reqID); + debugBelch("is blocked on proc (request: %ld)", tso->block_info.async_result->reqID); break; #endif case BlockedOnDelay: - debugBelch("is blocked until %d", 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", @@ -3468,7 +4314,7 @@ printThreadBlockage(StgTSO *tso) case NotBlocked: debugBelch("is not blocked"); break; -#if defined(PAR) +#if defined(PARALLEL_HASKELL) case BlockedOnGA: debugBelch("is blocked on global address; local FM_BQ is %p (%s)", tso->block_info.closure, info_type(tso->block_info.closure)); @@ -3493,26 +4339,37 @@ printThreadBlockage(StgTSO *tso) } } -static void -printThreadStatus(StgTSO *tso) +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]; @@ -3520,7 +4377,7 @@ printAllThreads(void) time_string, rtsFalse/*no commas!*/); debugBelch("all threads at [%s]:\n", time_string); -# elif defined(PAR) +# elif defined(PARALLEL_HASKELL) char time_string[TIME_STR_LEN], node_str[NODE_STR_LEN]; ullong_format_string(CURRENT_TIME, time_string, rtsFalse/*no commas!*/); @@ -3530,25 +4387,43 @@ 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). */ -# if defined(PAR) +# if defined(PARALLEL_HASKELL) void print_bq (StgClosure *node) { @@ -3675,58 +4550,40 @@ print_bq (StgClosure *node) } /* for */ debugBelch("\n"); } -#else -/* - Nice and easy: only TSOs on the blocking queue -*/ -void -print_bq (StgClosure *node) -{ - StgTSO *tso; - - ASSERT(node!=(StgClosure*)NULL); // sanity check - for (tso = ((StgBlockingQueue*)node)->blocking_queue; - tso != END_TSO_QUEUE; - tso=tso->link) { - ASSERT(tso!=NULL && tso!=END_TSO_QUEUE); // sanity check - ASSERT(get_itbl(tso)->type == TSO); // guess what, sanity check - debugBelch(" TSO %d (%p),", tso->id, tso); - } - debugBelch("\n"); -} # endif -#if defined(PAR) +#if defined(PARALLEL_HASKELL) 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()); -#elif defined(PAR) - debugBelch("== "); + 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("== "); #else - debugBelch("sched: "); + debugBelch("sched: "); #endif - vdebugBelch(s, ap); - debugBelch("\n"); - va_end(ap); + vdebugBelch(s, ap); + debugBelch("\n"); + va_end(ap); } #endif /* DEBUG */