X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=rts%2FSchedule.c;h=141c973f3aa09693f4e94c4a6f3253163469727d;hb=0506cb7ec75321eaacc6c279d01d82368d2ca125;hp=d9adda415cba2a0c4b55b9b61698f439c416b285;hpb=7434fb5be86c7cc59c520dc07dc96b27b4fb1406;p=ghc-hetmet.git diff --git a/rts/Schedule.c b/rts/Schedule.c index d9adda4..141c973 100644 --- a/rts/Schedule.c +++ b/rts/Schedule.c @@ -1,17 +1,17 @@ /* --------------------------------------------------------------------------- * - * (c) The GHC Team, 1998-2005 + * (c) The GHC Team, 1998-2006 * * The scheduler and thread-related functionality * * --------------------------------------------------------------------------*/ #include "PosixSource.h" +#define KEEP_LOCKCLOSURE #include "Rts.h" #include "SchedAPI.h" #include "RtsUtils.h" #include "RtsFlags.h" -#include "BlockAlloc.h" #include "OSThreads.h" #include "Storage.h" #include "StgRun.h" @@ -19,7 +19,6 @@ #include "Schedule.h" #include "StgMiscClosures.h" #include "Interpreter.h" -#include "Exception.h" #include "Printer.h" #include "RtsSignals.h" #include "Sanity.h" @@ -30,19 +29,14 @@ #include "ThreadLabels.h" #include "LdvProfile.h" #include "Updates.h" -#ifdef PROFILING #include "Proftimer.h" #include "ProfHeap.h" -#endif -#if defined(GRAN) || defined(PARALLEL_HASKELL) -# include "GranSimRts.h" -# include "GranSim.h" -# include "ParallelRts.h" -# include "Parallel.h" -# include "ParallelDebug.h" -# include "FetchMe.h" -# include "HLC.h" -#endif +#include "GC.h" +#include "Weak.h" +#include "EventLog.h" + +/* PARALLEL_HASKELL includes go here */ + #include "Sparks.h" #include "Capability.h" #include "Task.h" @@ -51,6 +45,9 @@ #include "win32/IOManager.h" #endif #include "Trace.h" +#include "RaiseAsync.h" +#include "Threads.h" +#include "ThrIOManager.h" #ifdef HAVE_SYS_TYPES_H #include @@ -77,28 +74,6 @@ * Global variables * -------------------------------------------------------------------------- */ -#if defined(GRAN) - -StgTSO* ActiveTSO = NULL; /* for assigning system costs; GranSim-Light only */ -/* rtsTime TimeOfNextEvent, EndOfTimeSlice; now in GranSim.c */ - -/* - In GranSim we have a runnable and a blocked queue for each processor. - In order to minimise code changes new arrays run_queue_hds/tls - are created. run_queue_hd is then a short cut (macro) for - run_queue_hds[CurrentProc] (see GranSim.h). - -- HWL -*/ -StgTSO *run_queue_hds[MAX_PROC], *run_queue_tls[MAX_PROC]; -StgTSO *blocked_queue_hds[MAX_PROC], *blocked_queue_tls[MAX_PROC]; -StgTSO *ccalling_threadss[MAX_PROC]; -/* We use the same global list of threads (all_threads) in GranSim as in - the std RTS (i.e. we are cheating). However, we don't use this list in - the GranSim specific code at the moment (so we are only potentially - cheating). */ - -#else /* !GRAN */ - #if !defined(THREADED_RTS) // Blocked/sleeping thrads StgTSO *blocked_queue_hd = NULL; @@ -110,7 +85,6 @@ StgTSO *sleeping_queue = NULL; // perhaps replace with a hash table? * 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. @@ -118,48 +92,24 @@ StgTSO *blackhole_queue = NULL; */ 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; - -/* flag set by signal handler to precipitate a context switch - * LOCK: none (just an advisory flag) +/* Set to true when the latest garbage collection failed to reclaim + * enough space, and the runtime should proceed to shut itself down in + * an orderly fashion (emitting profiling info etc.) */ -int context_switch = 0; +rtsBool heap_overflow = 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). + * + * NB. must be StgWord, we do xchg() on it. */ -nat recent_activity = ACTIVITY_YES; +volatile StgWord recent_activity = ACTIVITY_YES; /* if this flag is set as well, give up execution - * LOCK: none (changes once, from false->true) - */ -rtsBool sched_state = SCHED_RUNNING; - -/* Next thread ID to allocate. - * LOCK: sched_mutex - */ -static StgThreadID next_thread_id = 1; - -/* 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) - * + 1 (the closure to enter) - * + 1 (stg_ap_v_ret) - * + 1 (spare slot req'd by stg_ap_v_ret) - * - * A thread with this stack will bomb immediately with a stack - * overflow, which will increase its stack size. + * LOCK: none (changes monotonically) */ -#define MIN_STACK_WORDS (RESERVED_STACK_WORDS + sizeofW(StgStopFrame) + 3) - -#if defined(GRAN) -StgTSO *CurrentTSO; -#endif +volatile StgWord sched_state = SCHED_RUNNING; /* This is used in `TSO.h' and gcc 2.96 insists that this variable actually * exists - earlier gccs apparently didn't. @@ -182,10 +132,8 @@ rtsBool shutting_down_scheduler = rtsFalse; Mutex sched_mutex; #endif -#if defined(PARALLEL_HASKELL) -StgTSO *LastTSO; -rtsTime TimeOfLastYield; -rtsBool emitSchedule = rtsTrue; +#if !defined(mingw32_HOST_OS) +#define FORKPROCESS_PRIMOP_SUPPORTED #endif /* ----------------------------------------------------------------------------- @@ -200,26 +148,24 @@ static Capability *schedule (Capability *initialCapability, Task *task); // scheduler clearer. // static void schedulePreLoop (void); +static void scheduleFindWork (Capability *cap); #if defined(THREADED_RTS) -static void schedulePushWork(Capability *cap, Task *task); +static void scheduleYield (Capability **pcap, 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 +static void schedulePushWork(Capability *cap, Task *task); #if defined(PARALLEL_HASKELL) -static StgTSO *scheduleSendPendingMessages(void); -static void scheduleActivateSpark(void); -static rtsBool scheduleGetRemoteWork(rtsBool *receivedFinish); +static rtsBool scheduleGetRemoteWork(Capability *cap); +static void scheduleSendPendingMessages(void); #endif -#if defined(PAR) || defined(GRAN) -static void scheduleGranParReport(void); +#if defined(PARALLEL_HASKELL) || defined(THREADED_RTS) +static void scheduleActivateSpark(Capability *cap); #endif -static void schedulePostRunThread(void); +static void schedulePostRunThread(Capability *cap, StgTSO *t); static rtsBool scheduleHandleHeapOverflow( Capability *cap, StgTSO *t ); static void scheduleHandleStackOverflow( Capability *cap, Task *task, StgTSO *t); @@ -228,32 +174,20 @@ static rtsBool scheduleHandleYield( Capability *cap, StgTSO *t, static void scheduleHandleThreadBlocked( StgTSO *t ); static rtsBool scheduleHandleThreadFinished( Capability *cap, Task *task, StgTSO *t ); -static rtsBool scheduleDoHeapProfile(rtsBool ready_to_gc); +static rtsBool scheduleNeedHeapProfile(rtsBool ready_to_gc); static Capability *scheduleDoGC(Capability *cap, Task *task, - rtsBool force_major, - void (*get_roots)(evac_fn)); + rtsBool force_major); -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 StgTSO *threadStackUnderflow(Task *task, StgTSO *tso); static void deleteThread (Capability *cap, StgTSO *tso); static void deleteAllThreads (Capability *cap); -#ifdef DEBUG -static void printThreadBlockage(StgTSO *tso); -static void printThreadStatus(StgTSO *tso); -void printThreadQueue(StgTSO *tso); -#endif - -#if defined(PARALLEL_HASKELL) -StgTSO * createSparkThread(rtsSpark spark); -StgTSO * activateSpark (rtsSpark spark); +#ifdef FORKPROCESS_PRIMOP_SUPPORTED +static void deleteThread_(Capability *cap, StgTSO *tso); #endif #ifdef DEBUG @@ -305,6 +239,7 @@ addToRunQueue( Capability *cap, StgTSO *t ) This revolves around the global event queue, which determines what to do next. Therefore, it's more complicated than either the concurrent or the parallel (GUM) setup. + This version has been entirely removed (JB 2008/08). GUM version: GUM iterates over incoming messages. @@ -315,6 +250,12 @@ addToRunQueue( Capability *cap, StgTSO *t ) (see PendingFetches). This is not the ugliest code you could imagine, but it's bloody close. + (JB 2008/08) This version was formerly indicated by a PP-Flag PAR, + now by PP-flag PARALLEL_HASKELL. The Eden RTS (in GHC-6.x) uses it, + as well as future GUM versions. This file has been refurbished to + only contain valid code, which is however incomplete, refers to + invalid includes etc. + ------------------------------------------------------------------------ */ static Capability * @@ -323,15 +264,8 @@ schedule (Capability *initialCapability, Task *task) StgTSO *t; Capability *cap; StgThreadReturnCode ret; -#if defined(GRAN) - rtsEvent *event; -#elif defined(PARALLEL_HASKELL) - StgTSO *tso; - GlobalTaskId pe; +#if defined(PARALLEL_HASKELL) rtsBool receivedFinish = rtsFalse; -# if defined(DEBUG) - nat tp_size, sp_size; // stats only -# endif #endif nat prev_what_next; rtsBool ready_to_gc; @@ -349,6 +283,12 @@ schedule (Capability *initialCapability, Task *task) "### NEW SCHEDULER LOOP (task: %p, cap: %p)", task, initialCapability); + if (running_finalizers) { + errorBelch("error: a C finalizer called back into Haskell.\n" + " use Foreign.Concurrent.newForeignPtr for Haskell finalizers."); + stg_exit(EXIT_FAILURE); + } + schedulePreLoop(); // ----------------------------------------------------------- @@ -356,37 +296,12 @@ schedule (Capability *initialCapability, Task *task) #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 while (TERMINATION_CONDITION) { -#if defined(GRAN) - /* Choose the processor with the next event */ - CurrentProc = event->proc; - CurrentTSO = event->tso; -#endif - -#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); - } -#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). @@ -439,8 +354,15 @@ schedule (Capability *initialCapability, Task *task) discardSparksCap(cap); #endif /* scheduleDoGC() deletes all the threads */ - cap = scheduleDoGC(cap,task,rtsFalse,GetRoots); - break; + cap = scheduleDoGC(cap,task,rtsFalse); + + // after scheduleDoGC(), we must be shutting down. Either some + // other Capability did the final GC, or we did it above, + // either way we can fall through to the SCHED_SHUTTING_DOWN + // case now. + ASSERT(sched_state == SCHED_SHUTTING_DOWN); + // fall through + case SCHED_SHUTTING_DOWN: debugTrace(DEBUG_sched, "SCHED_SHUTTING_DOWN"); // If we are a worker, just exit. If we're a bound thread @@ -454,35 +376,29 @@ schedule (Capability *initialCapability, Task *task) barf("sched_state: %d", sched_state); } -#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) { - debugTrace(DEBUG_sched, - "turning spark of closure %p into a thread", - (StgClosure *)spark); - createSparkThread(cap,spark); - } - } - } -#endif // THREADED_RTS + scheduleFindWork(cap); - scheduleStartSignalHandlers(cap); + /* work pushing, currently relevant only for THREADED_RTS: + (pushes threads, wakes up idle capabilities for stealing) */ + schedulePushWork(cap,task); - // 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); } +#if defined(PARALLEL_HASKELL) + /* since we perform a blocking receive and continue otherwise, + either we never reach here or we definitely have work! */ + // from here: non-empty run queue + ASSERT(!emptyRunQueue(cap)); - scheduleCheckWakeupThreads(cap); + if (PacketsWaiting()) { /* now process incoming messages, if any + pending... - scheduleCheckBlockedThreads(cap); + CAUTION: scheduleGetRemoteWork called + above, waits for messages as well! */ + processMessages(cap, &receivedFinish); + } +#endif // PARALLEL_HASKELL: non-empty run queue! scheduleDetectDeadlock(cap,task); + #if defined(THREADED_RTS) cap = task->cap; // reload cap, it might have changed #endif @@ -495,54 +411,37 @@ schedule (Capability *initialCapability, Task *task) // // 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 - continue; // nothing to do + +#if defined(THREADED_RTS) + if (first) + { + // XXX: ToDo + // // 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); } -#if defined(PARALLEL_HASKELL) - scheduleSendPendingMessages(); - if (emptyRunQueue(cap) && scheduleActivateSpark()) - continue; - -#if defined(SPARKS) - ASSERT(next_fish_to_send_at==0); // i.e. no delayed fishes left! + yield: + scheduleYield(&cap,task); + if (emptyRunQueue(cap)) continue; // look for work again #endif - /* 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(); +#if !defined(THREADED_RTS) && !defined(mingw32_HOST_OS) + if ( emptyRunQueue(cap) ) { + ASSERT(sched_state >= SCHED_INTERRUPTING); } #endif -#if defined(GRAN) - scheduleProcessEvent(event); -#endif - // // Get a thread to run // t = popRunQueue(cap); -#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 #if defined(THREADED_RTS) // Check whether we can run this thread in the current task. @@ -553,11 +452,11 @@ schedule (Capability *initialCapability, Task *task) if (bound) { if (bound == task) { debugTrace(DEBUG_sched, - "### Running thread %d in bound thread", t->id); + "### Running thread %lu in bound thread", (unsigned long)t->id); // yes, the Haskell thread is bound to the current native thread } else { debugTrace(DEBUG_sched, - "### thread %d bound to another OS thread", t->id); + "### thread %lu bound to another OS thread", (unsigned long)t->id); // no, bound to a different Haskell thread: pass to that thread pushOnRunQueue(cap,t); continue; @@ -566,7 +465,7 @@ schedule (Capability *initialCapability, Task *task) // The thread we want to run is unbound. if (task->tso) { debugTrace(DEBUG_sched, - "### this OS thread cannot run thread %d", t->id); + "### this OS thread cannot run thread %lu", (unsigned long)t->id); // no, the current native thread is bound to a different // Haskell thread, so pass it to any worker thread pushOnRunQueue(cap,t); @@ -576,40 +475,72 @@ schedule (Capability *initialCapability, Task *task) } #endif - cap->r.rCurrentTSO = t; - + // If we're shutting down, and this thread has not yet been + // killed, kill it now. This sometimes happens when a finalizer + // thread is created by the final GC, or a thread previously + // in a foreign call returns. + if (sched_state >= SCHED_INTERRUPTING && + !(t->what_next == ThreadComplete || t->what_next == ThreadKilled)) { + deleteThread(cap,t); + } + /* context switches are initiated by the timer signal, unless * the user specified "context switch as often as possible", with * +RTS -C0 */ if (RtsFlags.ConcFlags.ctxtSwitchTicks == 0 && !emptyThreadQueues(cap)) { - context_switch = 1; + cap->context_switch = 1; } run_thread: + // CurrentTSO is the thread to run. t might be different if we + // loop back to run_thread, so make sure to set CurrentTSO after + // that. + cap->r.rCurrentTSO = t; + debugTrace(DEBUG_sched, "-->> running thread %ld %s ...", (long)t->id, whatNext_strs[t->what_next]); -#if defined(PROFILING) startHeapProfTimer(); -#endif + + // Check for exceptions blocked on this thread + maybePerformBlockedException (cap, t); // ---------------------------------------------------------------------- // Run the current thread ASSERT_FULL_CAPABILITY_INVARIANTS(cap,task); ASSERT(t->cap == cap); + ASSERT(t->bound ? t->bound->cap == cap : 1); prev_what_next = t->what_next; errno = t->saved_errno; +#if mingw32_HOST_OS + SetLastError(t->saved_winerror); +#endif + cap->in_haskell = rtsTrue; - dirtyTSO(t); + dirty_TSO(cap,t); + +#if defined(THREADED_RTS) + if (recent_activity == ACTIVITY_DONE_GC) { + // ACTIVITY_DONE_GC means we turned off the timer signal to + // conserve power (see #1623). Re-enable it here. + nat prev; + prev = xchg((P_)&recent_activity, ACTIVITY_YES); + if (prev == ACTIVITY_DONE_GC) { + startTimer(); + } + } else { + recent_activity = ACTIVITY_YES; + } +#endif - recent_activity = ACTIVITY_YES; + postEvent(cap, EVENT_RUN_THREAD, t->id, 0); switch (prev_what_next) { @@ -654,6 +585,12 @@ run_thread: // XXX: possibly bogus for SMP because this thread might already // be running again, see code below. t->saved_errno = errno; +#if mingw32_HOST_OS + // Similarly for Windows error code + t->saved_winerror = GetLastError(); +#endif + + postEvent (cap, EVENT_STOP_THREAD, t->id, ret); #if defined(THREADED_RTS) // If ret is ThreadBlocked, and this Task is bound to the TSO that @@ -664,9 +601,9 @@ run_thread: // immediately and return to normaility. if (ret == ThreadBlocked) { debugTrace(DEBUG_sched, - "--<< thread %d (%s) stopped: blocked", - t->id, whatNext_strs[t->what_next]); - continue; + "--<< thread %lu (%s) stopped: blocked", + (unsigned long)t->id, whatNext_strs[t->what_next]); + goto yield; } #endif @@ -676,12 +613,14 @@ run_thread: // ---------------------------------------------------------------------- // Costs for the scheduler are assigned to CCS_SYSTEM -#if defined(PROFILING) stopHeapProfTimer(); +#if defined(PROFILING) CCCS = CCS_SYSTEM; #endif - schedulePostRunThread(); + schedulePostRunThread(cap,t); + + t = threadStackUnderflow(task,t); ready_to_gc = rtsFalse; @@ -714,14 +653,10 @@ run_thread: 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); + if (ready_to_gc || scheduleNeedHeapProfile(ready_to_gc)) { + cap = scheduleDoGC(cap,task,rtsFalse); } } /* end of while() */ - - debugTrace(PAR_DEBUG_verbose, - "== Leaving schedule() after having received Finish"); } /* ---------------------------------------------------------------------------- @@ -731,36 +666,122 @@ run_thread: 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); - - debugTrace (DEBUG_gran, - "GRAN: Init CurrentTSO (in schedule) = %p", - CurrentTSO); - IF_DEBUG(gran, G_TSO(CurrentTSO, 5)); - - if (RtsFlags.GranFlags.Light) { - /* Save current time; GranSim Light only */ - CurrentTSO->gran.clock = CurrentTime[CurrentProc]; - } + // initialisation for scheduler - what cannot go into initScheduler() +} + +/* ----------------------------------------------------------------------------- + * scheduleFindWork() + * + * Search for work to do, and handle messages from elsewhere. + * -------------------------------------------------------------------------- */ + +static void +scheduleFindWork (Capability *cap) +{ + 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); + +#if defined(THREADED_RTS) || defined(PARALLEL_HASKELL) + if (emptyRunQueue(cap)) { scheduleActivateSpark(cap); } +#endif + +#if defined(PARALLEL_HASKELL) + // if messages have been buffered... + scheduleSendPendingMessages(); +#endif + +#if defined(PARALLEL_HASKELL) + if (emptyRunQueue(cap)) { + receivedFinish = scheduleGetRemoteWork(cap); + continue; // a new round, (hopefully) with new work + /* + in GUM, this a) sends out a FISH and returns IF no fish is + out already + b) (blocking) awaits and receives messages + + in Eden, this is only the blocking receive, as b) in GUM. + */ + } #endif } +#if defined(THREADED_RTS) +STATIC_INLINE rtsBool +shouldYieldCapability (Capability *cap, Task *task) +{ + // we need to yield this capability to someone else if.. + // - another thread is initiating a GC + // - another Task is returning from a foreign call + // - the thread at the head of the run queue cannot be run + // by this Task (it is bound to another Task, or it is unbound + // and this task it bound). + return (waiting_for_gc || + cap->returning_tasks_hd != NULL || + (!emptyRunQueue(cap) && (task->tso == NULL + ? cap->run_queue_hd->bound != NULL + : cap->run_queue_hd->bound != task))); +} + +// This is the single place where a Task goes to sleep. There are +// two reasons it might need to sleep: +// - there are no threads to run +// - we need to yield this Capability to someone else +// (see shouldYieldCapability()) +// +// Careful: the scheduler loop is quite delicate. Make sure you run +// the tests in testsuite/concurrent (all ways) after modifying this, +// and also check the benchmarks in nofib/parallel for regressions. + +static void +scheduleYield (Capability **pcap, Task *task) +{ + Capability *cap = *pcap; + + // if we have work, and we don't need to give up the Capability, continue. + if (!shouldYieldCapability(cap,task) && + (!emptyRunQueue(cap) || + !emptyWakeupQueue(cap) || + blackholes_need_checking || + sched_state >= SCHED_INTERRUPTING)) + return; + + // otherwise yield (sleep), and keep yielding if necessary. + do { + yieldCapability(&cap,task); + } + while (shouldYieldCapability(cap,task)); + + // note there may still be no threads on the run queue at this + // point, the caller has to check. + + *pcap = cap; + return; +} +#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) { + /* following code not for PARALLEL_HASKELL. I kept the call general, + future GUM versions might use pushing in a distributed setup */ +#if defined(THREADED_RTS) + Capability *free_caps[n_capabilities], *cap0; nat i, n_free_caps; @@ -769,9 +790,11 @@ schedulePushWork(Capability *cap USED_IF_THREADS, // 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; + if (cap->run_queue_hd == END_TSO_QUEUE) { + if (sparkPoolSizeCap(cap) < 2) return; + } else { + if (cap->run_queue_hd->_link == END_TSO_QUEUE && + sparkPoolSizeCap(cap) < 1) return; } // First grab as many free Capabilities as we can. @@ -803,32 +826,40 @@ schedulePushWork(Capability *cap USED_IF_THREADS, StgTSO *prev, *t, *next; rtsBool pushed_to_all; - debugTrace(DEBUG_sched, "excess threads on run queue and %d free capabilities, sharing...", n_free_caps); + debugTrace(DEBUG_sched, + "cap %d: %s and %d free capabilities, sharing...", + cap->no, + (!emptyRunQueue(cap) && cap->run_queue_hd->_link != END_TSO_QUEUE)? + "excess threads on run queue":"sparks to share (>=2)", + 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; + t = prev->_link; + prev->_link = END_TSO_QUEUE; for (; t != END_TSO_QUEUE; t = next) { - next = t->link; - t->link = END_TSO_QUEUE; + 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; + setTSOLink(cap, prev, t); prev = t; } else if (i == n_free_caps) { pushed_to_all = rtsTrue; i = 0; // keep one for us - prev->link = t; + setTSOLink(cap, prev, t); prev = t; } else { - debugTrace(DEBUG_sched, "pushing thread %d to capability %d", t->id, free_caps[i]->no); + debugTrace(DEBUG_sched, "pushing thread %lu to capability %d", (unsigned long)t->id, free_caps[i]->no); appendToRunQueue(free_caps[i],t); + + postEvent (cap, EVENT_MIGRATE_THREAD, t->id, free_caps[i]->no); + if (t->bound) { t->bound->cap = free_caps[i]; } t->cap = free_caps[i]; i++; @@ -837,6 +868,9 @@ schedulePushWork(Capability *cap USED_IF_THREADS, cap->run_queue_tl = prev; } +#ifdef SPARK_PUSHING + /* JB I left this code in place, it would work but is not necessary */ + // 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) { @@ -844,7 +878,7 @@ schedulePushWork(Capability *cap USED_IF_THREADS, // i is the next free capability to push to for (; i < n_free_caps; i++) { if (emptySparkPoolCap(free_caps[i])) { - spark = findSpark(cap); + spark = tryStealSpark(cap->sparks); if (spark != NULL) { debugTrace(DEBUG_sched, "pushing spark %p to capability %d", spark, free_caps[i]->no); newSpark(&(free_caps[i]->r), spark); @@ -852,26 +886,30 @@ schedulePushWork(Capability *cap USED_IF_THREADS, } } } +#endif /* SPARK_PUSHING */ // release the capabilities for (i = 0; i < n_free_caps; i++) { task->cap = free_caps[i]; - releaseCapability(free_caps[i]); + releaseAndWakeupCapability(free_caps[i]); } } task->cap = cap; // reset to point to our Capability. + +#endif /* THREADED_RTS */ + } -#endif /* ---------------------------------------------------------------------------- * Start any pending signal handlers * ------------------------------------------------------------------------- */ -#if defined(RTS_USER_SIGNALS) && (!defined(THREADED_RTS) || defined(mingw32_HOST_OS)) +#if defined(RTS_USER_SIGNALS) && !defined(THREADED_RTS) static void scheduleStartSignalHandlers(Capability *cap) { - if (signals_pending()) { // safe outside the lock + if (RtsFlags.MiscFlags.install_signal_handlers && signals_pending()) { + // safe outside the lock startSignalHandlers(cap); } } @@ -919,7 +957,7 @@ scheduleCheckWakeupThreads(Capability *cap USED_IF_THREADS) 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; + setTSOLink(cap, cap->run_queue_tl, cap->wakeup_queue_hd); cap->run_queue_tl = cap->wakeup_queue_tl; } cap->wakeup_queue_hd = cap->wakeup_queue_tl = END_TSO_QUEUE; @@ -938,8 +976,13 @@ scheduleCheckBlackHoles (Capability *cap) { ACQUIRE_LOCK(&sched_mutex); if ( blackholes_need_checking ) { - checkBlackHoles(cap); blackholes_need_checking = rtsFalse; + // important that we reset the flag *before* checking the + // blackhole queue, otherwise we could get deadlock. This + // happens as follows: we wake up a thread that + // immediately runs on another Capability, blocks on a + // blackhole, and then we reset the blackholes_need_checking flag. + checkBlackHoles(cap); } RELEASE_LOCK(&sched_mutex); } @@ -983,18 +1026,19 @@ scheduleDetectDeadlock (Capability *cap, Task *task) // 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); + cap = scheduleDoGC (cap, task, rtsTrue/*force major GC*/); + // when force_major == rtsTrue. scheduleDoGC sets + // recent_activity to ACTIVITY_DONE_GC and turns off the timer + // signal. - recent_activity = ACTIVITY_DONE_GC; - if ( !emptyRunQueue(cap) ) return; -#if defined(RTS_USER_SIGNALS) && (!defined(THREADED_RTS) || defined(mingw32_HOST_OS)) +#if defined(RTS_USER_SIGNALS) && !defined(THREADED_RTS) /* If we have user-installed signal handlers, then wait * for signals to arrive rather then bombing out with a * deadlock. */ - if ( anyUserHandlers() ) { + if ( RtsFlags.MiscFlags.install_signal_handlers && anyUserHandlers() ) { debugTrace(DEBUG_sched, "still deadlocked, waiting for signals..."); @@ -1006,6 +1050,8 @@ scheduleDetectDeadlock (Capability *cap, Task *task) // either we have threads to run, or we were interrupted: ASSERT(!emptyRunQueue(cap) || sched_state >= SCHED_INTERRUPTING); + + return; } #endif @@ -1019,7 +1065,8 @@ scheduleDetectDeadlock (Capability *cap, Task *task) case BlockedOnBlackHole: case BlockedOnException: case BlockedOnMVar: - raiseAsync(cap, task->tso, (StgClosure *)NonTermination_closure); + throwToSingleThreaded(cap, task->tso, + (StgClosure *)nonTermination_closure); return; default: barf("deadlock: main thread blocked in a strange way"); @@ -1030,164 +1077,15 @@ scheduleDetectDeadlock (Capability *cap, Task *task) } } -/* ---------------------------------------------------------------------------- - * 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; - } - /* Ignore ContinueThreads for completed threads */ - if (CurrentTSO->what_next == ThreadComplete) { - debugBelch("ghuH: found a ContinueThread event for completed thread %d (%p) [PE %d] (ignoring ContinueThread)\n", - CurrentTSO->id, CurrentTSO, CurrentProc); - goto next_thread; - } - /* Ignore ContinueThreads for threads that are being migrated */ - if (PROCS(CurrentTSO)==Nowhere) { - debugBelch("ghuH: trying to run the migrating TSO %d (%p) [PE %d] (ignoring ContinueThread)\n", - CurrentTSO->id, CurrentTSO, CurrentProc); - goto next_thread; - } - /* The thread should be at the beginning of the run queue */ - if (CurrentTSO!=run_queue_hds[CurrentProc]) { - debugBelch("ghuH: TSO %d (%p) [PE %d] is not at the start of the run_queue when doing a ContinueThread\n", - CurrentTSO->id, CurrentTSO, CurrentProc); - break; // run the thread anyway - } - /* - new_event(proc, proc, CurrentTime[proc], - FindWork, - (StgTSO*)NULL, (StgClosure*)NULL, (rtsSpark*)NULL); - goto next_thread; - */ /* Catches superfluous CONTINUEs -- should be unnecessary */ - break; // now actually run the thread; DaH Qu'vam yImuHbej - - case FetchNode: - do_the_fetchnode(event); - goto next_thread; /* handle next event in event queue */ - - case GlobalBlock: - do_the_globalblock(event); - goto next_thread; /* handle next event in event queue */ - - case FetchReply: - do_the_fetchreply(event); - goto next_thread; /* handle next event in event queue */ - - case UnblockThread: /* Move from the blocked queue to the tail of */ - do_the_unblock(event); - goto next_thread; /* handle next event in event queue */ - - case ResumeThread: /* Move from the blocked queue to the tail of */ - /* the runnable queue ( i.e. Qu' SImqa'lu') */ - event->tso->gran.blocktime += - CurrentTime[CurrentProc] - event->tso->gran.blockedat; - do_the_startthread(event); - goto next_thread; /* handle next event in event queue */ - - case StartThread: - do_the_startthread(event); - goto next_thread; /* handle next event in event queue */ - - case MoveThread: - do_the_movethread(event); - goto next_thread; /* handle next event in event queue */ - - case MoveSpark: - do_the_movespark(event); - goto next_thread; /* handle next event in event queue */ - - case FindWork: - do_the_findwork(event); - goto next_thread; /* handle next event in event queue */ - - default: - barf("Illegal event type %u\n", event->evttype); - } /* switch */ - - /* This point was scheduler_loop in the old RTS */ - - IF_DEBUG(gran, debugBelch("GRAN: after main switch\n")); - - TimeOfLastEvent = CurrentTime[CurrentProc]; - TimeOfNextEvent = get_time_of_next_event(); - IgnoreEvents=(TimeOfNextEvent==0); // HWL HACK - // CurrentTSO = ThreadQueueHd; - - IF_DEBUG(gran, debugBelch("GRAN: time of next event is: %ld\n", - TimeOfNextEvent)); - - if (RtsFlags.GranFlags.Light) - GranSimLight_leave_system(event, &ActiveTSO); - - EndOfTimeSlice = CurrentTime[CurrentProc]+RtsFlags.GranFlags.time_slice; - - IF_DEBUG(gran, - debugBelch("GRAN: end of time-slice is %#lx\n", EndOfTimeSlice)); - - /* in a GranSim setup the TSO stays on the run queue */ - t = CurrentTSO; - /* Take a thread from the run queue. */ - POP_RUN_QUEUE(t); // take_off_run_queue(t); - - IF_DEBUG(gran, - debugBelch("GRAN: About to run current thread, which is\n"); - G_TSO(t,5)); - - context_switch = 0; // turned on via GranYield, checking events and time slice - - IF_DEBUG(gran, - DumpGranEvent(GR_SCHEDULE, t)); - - procStatus[CurrentProc] = Busy; -} -#endif // GRAN /* ---------------------------------------------------------------------------- * Send pending messages (PARALLEL_HASKELL only) * ------------------------------------------------------------------------- */ #if defined(PARALLEL_HASKELL) -static StgTSO * +static void scheduleSendPendingMessages(void) { - StgSparkPool *pool; - rtsSpark spark; - StgTSO *t; # if defined(PAR) // global Mem.Mgmt., omit for now if (PendingFetches != END_BF_QUEUE) { @@ -1204,75 +1102,33 @@ scheduleSendPendingMessages(void) #endif /* ---------------------------------------------------------------------------- - * Activate spark threads (PARALLEL_HASKELL only) + * Activate spark threads (PARALLEL_HASKELL and THREADED_RTS) * ------------------------------------------------------------------------- */ -#if defined(PARALLEL_HASKELL) +#if defined(PARALLEL_HASKELL) || defined(THREADED_RTS) static void -scheduleActivateSpark(void) +scheduleActivateSpark(Capability *cap) { -#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. -*/ - - /* :-[ no local threads => look out for local sparks */ - /* the spark pool for the current PE */ - pool = &(cap.r.rSparks); // JB: cap = (old) MainCap - if (advisory_thread_count < RtsFlags.ParFlags.maxThreads && - pool->hd < pool->tl) { - /* - * ToDo: add GC code check that we really have enough heap afterwards!! - * Old comment: - * If we're here (no runnable threads) and we have pending - * sparks, we must have a space problem. Get enough space - * to turn one of those pending sparks into a - * 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 + if (anySparks()) + { + createSparkThread(cap); + debugTrace(DEBUG_sched, "creating a spark thread"); + } } -#endif // PARALLEL_HASKELL +#endif // PARALLEL_HASKELL || THREADED_RTS /* ---------------------------------------------------------------------------- * Get work from a remote node (PARALLEL_HASKELL only) * ------------------------------------------------------------------------- */ #if defined(PARALLEL_HASKELL) -static rtsBool -scheduleGetRemoteWork(rtsBool *receivedFinish) +static rtsBool /* return value used in PARALLEL_HASKELL only */ +scheduleGetRemoteWork (Capability *cap STG_UNUSED) { - ASSERT(emptyRunQueue()); +#if defined(PARALLEL_HASKELL) + rtsBool receivedFinish = rtsFalse; + // idle() , i.e. send all buffers, wait for work if (RtsFlags.ParFlags.BufferTime) { IF_PAR_DEBUG(verbose, debugBelch("...send all pending data,")); @@ -1282,262 +1138,64 @@ scheduleGetRemoteWork(rtsBool *receivedFinish) 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); - - /* =8-[ no local sparks => look for work on other PEs */ - /* - * We really have absolutely no work. Send out a fish - * (there may be some out there already), and wait for - * something to arrive. We clearly can't run any threads - * until a SCHEDULE or RESUME arrives, and so that's what - * we're hoping to see. (Of course, we still have to - * respond to other types of messages.) - */ - rtsTime now = msTime() /*CURRENT_TIME*/; - IF_PAR_DEBUG(verbose, - debugBelch("-- now=%ld\n", 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 && - 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(); - } - now = msTime(); - } while (!*receivedFinish || now sent delayed fish (%d processMessages); active/total threads=%d/%d\n",now,iq,run_queue_len(),advisory_thread_count)); - - } - - // 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++; - } - */ + /* this would be the place for fishing in GUM... - /* 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 + if (no-earlier-fish-around) + sendFish(choosePe()); + */ -/* ---------------------------------------------------------------------------- - * PAR/GRAN: Report stats & debugging info(?) - * ------------------------------------------------------------------------- */ + // Eden:just look for incoming messages (blocking receive) + IF_PAR_DEBUG(verbose, + debugBelch("...wait for incoming messages...\n")); + processMessages(cap, &receivedFinish); // blocking receive... -#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); + return receivedFinish; + // reenter scheduling look after having received something - /* 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. +#else /* !PARALLEL_HASKELL, i.e. THREADED_RTS */ -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. - */ + return rtsFalse; /* return value unused in THREADED_RTS */ - /* ToDo: write something to the log-file - if (RTSflags.ParFlags.granSimStats && !sameThread) - DumpGranEvent(GR_SCHEDULE, RunnableThreadsHd); - - CurrentTSO = t; - */ - /* the spark pool for the current PE */ - 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_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 && - (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 - event for LastTSO; with unfair scheduling we know that the - 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 +#endif /* PARALLEL_HASKELL */ +} +#endif // PARALLEL_HASKELL || THREADED_RTS /* ---------------------------------------------------------------------------- * After running a thread... * ------------------------------------------------------------------------- */ static void -schedulePostRunThread(void) +schedulePostRunThread (Capability *cap, StgTSO *t) { -#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 - if it is the same one as before */ - LastTSO = t; - TimeOfLastYield = CURRENT_TIME; -#endif + // We have to be able to catch transactions that are in an + // infinite loop as a result of seeing an inconsistent view of + // memory, e.g. + // + // atomically $ do + // [a,b] <- mapM readTVar [ta,tb] + // when (a == b) loop + // + // and a is never equal to b given a consistent view of memory. + // + if (t -> trec != NO_TREC && t -> why_blocked == NotBlocked) { + if (!stmValidateNestOfTransactions (t -> trec)) { + debugTrace(DEBUG_sched | DEBUG_stm, + "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. + throwToSingleThreaded_(cap, t, NULL, rtsTrue); + + ASSERT(get_itbl((StgClosure *)t->sp)->type == ATOMICALLY_FRAME); + } + } /* some statistics gathering in the parallel case */ - -#if defined(GRAN) || defined(PAR) || defined(EDEN) - switch (ret) { - case HeapOverflow: -# if defined(GRAN) - IF_DEBUG(gran, DumpGranEvent(GR_DESCHEDULE, t)); - globalGranStats.tot_heapover++; -# elif defined(PAR) - globalParStats.tot_heapover++; -# endif - 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++; -# endif - break; - - 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; - - case ThreadBlocked: -# if defined(GRAN) - debugTrace(DEBUG_sched, - "--<< 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; - - case ThreadFinished: - break; - - default: - barf("parGlobalStats: unknown return code"); - break; - } -#endif -} +} /* ----------------------------------------------------------------------------- * Handle a thread that returned to the scheduler with ThreadHeepOverflow @@ -1615,23 +1273,19 @@ scheduleHandleHeapOverflow( Capability *cap, StgTSO *t ) } debugTrace(DEBUG_sched, - "--<< thread %ld (%s) stopped: HeapOverflow\n", + "--<< thread %ld (%s) stopped: HeapOverflow", (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; + if (cap->r.rHpLim == NULL || cap->context_switch) { + // Sometimes we miss a context switch, e.g. when calling + // primitives in a tight loop, MAYBE_GC() doesn't check the + // context switch flag, and we end up waiting for a GC. + // See #1984, and concurrent/should_run/1984 + cap->context_switch = 0; + addToRunQueue(cap,t); + } else { + pushOnRunQueue(cap,t); } -#endif - - pushOnRunQueue(cap,t); return rtsTrue; /* actual GC is done at the end of the while loop in schedule() */ } @@ -1644,7 +1298,7 @@ static void scheduleHandleStackOverflow (Capability *cap, Task *task, StgTSO *t) { debugTrace (DEBUG_sched, - "--<< thread %ld (%s) stopped, StackOverflow\n", + "--<< thread %ld (%s) stopped, StackOverflow", (long)t->id, whatNext_strs[t->what_next]); /* just adjust the stack for this thread, then pop it back @@ -1677,7 +1331,7 @@ scheduleHandleYield( Capability *cap, StgTSO *t, nat prev_what_next ) // 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; + cap->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 @@ -1687,11 +1341,11 @@ scheduleHandleYield( Capability *cap, StgTSO *t, nat prev_what_next ) #ifdef DEBUG if (t->what_next != prev_what_next) { debugTrace(DEBUG_sched, - "--<< thread %ld (%s) stopped to switch evaluators\n", + "--<< thread %ld (%s) stopped to switch evaluators", (long)t->id, whatNext_strs[t->what_next]); } else { debugTrace(DEBUG_sched, - "--<< thread %ld (%s) stopped, yielding\n", + "--<< thread %ld (%s) stopped, yielding", (long)t->id, whatNext_strs[t->what_next]); } #endif @@ -1699,7 +1353,7 @@ scheduleHandleYield( Capability *cap, StgTSO *t, nat prev_what_next ) IF_DEBUG(sanity, //debugBelch("&& Doing sanity check on yielding TSO %ld.", t->id); checkTSO(t)); - ASSERT(t->link == END_TSO_QUEUE); + 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 @@ -1707,28 +1361,9 @@ scheduleHandleYield( Capability *cap, StgTSO *t, nat prev_what_next ) if (t->what_next != prev_what_next) { return rtsTrue; } - -#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 addToRunQueue(cap,t); -#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 return rtsFalse; } @@ -1743,69 +1378,28 @@ scheduleHandleThreadBlocked( StgTSO *t #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! - 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) - 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 */ // We don't need to do anything. The thread is blocked, and it // has tidied up its stack and placed itself on whatever queue // it needs to be on. -#if !defined(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 + // ASSERT(t->why_blocked != NotBlocked); + // Not true: for example, + // - in THREADED_RTS, the thread may already have been woken + // up by another Capability. This actually happens: try + // conc023 +RTS -N2. + // - the thread may have woken itself up already, because + // threadPaused() might have raised a blocked throwTo + // exception, see maybePerformBlockedException(). #ifdef DEBUG if (traceClass(DEBUG_sched)) { - debugTraceBegin("--<< thread %d (%s) stopped: ", - t->id, whatNext_strs[t->what_next]); + debugTraceBegin("--<< thread %lu (%s) stopped: ", + (unsigned long)t->id, whatNext_strs[t->what_next]); printThreadBlockage(t); debugTraceEnd(); } #endif - - /* Only for dumping event to log file - ToDo: do I need this in GranSim, too? - blockThread(t); - */ -#endif } /* ----------------------------------------------------------------------------- @@ -1821,50 +1415,14 @@ scheduleHandleThreadFinished (Capability *cap STG_UNUSED, Task *task, StgTSO *t) * We also end up here if the thread kills itself with an * uncaught exception, see Exception.cmm. */ - debugTrace(DEBUG_sched, "--++ thread %d (%s) finished", - t->id, whatNext_strs[t->what_next]); - -#if defined(GRAN) - endThread(t, CurrentProc); // clean-up the thread -#elif defined(PARALLEL_HASKELL) - /* For now all are advisory -- HWL */ - //if(t->priority==AdvisoryPriority) ?? - advisory_thread_count--; // JB: Caution with this counter, buggy! - -# 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 + debugTrace(DEBUG_sched, "--++ thread %lu (%s) finished", + (unsigned long)t->id, whatNext_strs[t->what_next]); -# if defined(PAR) - if (RtsFlags.ParFlags.ParStats.Full && - !RtsFlags.ParFlags.ParStats.Suppressed) - DumpEndEvent(CURRENT_PROC, t, rtsFalse /* not mandatory */); - - // 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 + // blocked exceptions can now complete, even if the thread was in + // blocked mode (see #2910). This unconditionally calls + // lockTSO(), which ensures that we don't miss any threads that + // are engaged in throwTo() with this thread as a target. + awakenBlockedExceptionQueue (cap, t); // // Check whether the thread that just completed was a bound @@ -1885,7 +1443,7 @@ scheduleHandleThreadFinished (Capability *cap STG_UNUSED, Task *task, StgTSO *t) // 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). + // step->threads list so there's no other way to find it). appendToRunQueue(cap,t); return rtsFalse; #else @@ -1908,7 +1466,11 @@ scheduleHandleThreadFinished (Capability *cap STG_UNUSED, Task *task, StgTSO *t) *(task->ret) = NULL; } if (sched_state >= SCHED_INTERRUPTING) { - task->stat = Interrupted; + if (heap_overflow) { + task->stat = HeapExhausted; + } else { + task->stat = Interrupted; + } } else { task->stat = Killed; } @@ -1923,36 +1485,21 @@ scheduleHandleThreadFinished (Capability *cap STG_UNUSED, Task *task, StgTSO *t) } /* ----------------------------------------------------------------------------- - * Perform a heap census, if PROFILING + * Perform a heap census * -------------------------------------------------------------------------- */ static rtsBool -scheduleDoHeapProfile( rtsBool ready_to_gc STG_UNUSED ) +scheduleNeedHeapProfile( 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); - - debugTrace(DEBUG_sched, "garbage collecting before heap census"); - GarbageCollect(GetRoots, rtsTrue); - - debugTrace(DEBUG_sched, "performing heap census"); - heapCensus(); - - performHeapProfile = rtsFalse; - return rtsTrue; // true <=> we already GC'd + return rtsTrue; + } else { + return rtsFalse; } -#endif - return rtsFalse; } /* ----------------------------------------------------------------------------- @@ -1960,17 +1507,34 @@ scheduleDoHeapProfile( rtsBool ready_to_gc STG_UNUSED ) * -------------------------------------------------------------------------- */ static Capability * -scheduleDoGC (Capability *cap, Task *task USED_IF_THREADS, - rtsBool force_major, void (*get_roots)(evac_fn)) +scheduleDoGC (Capability *cap, Task *task USED_IF_THREADS, rtsBool force_major) { - StgTSO *t; + rtsBool heap_census; #ifdef THREADED_RTS - static volatile StgWord waiting_for_gc; - rtsBool was_waiting; + /* extern static volatile StgWord waiting_for_gc; + lives inside capability.c */ + rtsBool gc_type, prev_pending_gc; nat i; #endif + if (sched_state == SCHED_SHUTTING_DOWN) { + // The final GC has already been done, and the system is + // shutting down. We'll probably deadlock if we try to GC + // now. + return cap; + } + #ifdef THREADED_RTS + if (sched_state < SCHED_INTERRUPTING + && RtsFlags.ParFlags.parGcEnabled + && N >= RtsFlags.ParFlags.parGcGen + && ! oldest_gen->steps[0].mark) + { + gc_type = PENDING_GC_PAR; + } else { + gc_type = PENDING_GC_SEQ; + } + // 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. @@ -1981,164 +1545,169 @@ scheduleDoGC (Capability *cap, Task *task USED_IF_THREADS, // 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) { + + /* Other capabilities are prevented from running yet more Haskell + threads if waiting_for_gc is set. Tested inside + yieldCapability() and releaseCapability() in Capability.c */ + + prev_pending_gc = cas(&waiting_for_gc, 0, gc_type); + if (prev_pending_gc) { do { - debugTrace(DEBUG_sched, "someone else is trying to GC..."); - if (cap) yieldCapability(&cap,task); + debugTrace(DEBUG_sched, "someone else is trying to GC (%d)...", + prev_pending_gc); + ASSERT(cap); + yieldCapability(&cap,task); } while (waiting_for_gc); return cap; // NOTE: task->cap might have changed here } - for (i=0; i < n_capabilities; i++) { - debugTrace(DEBUG_sched, "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"); - } - } + setContextSwitches(); + + // The final shutdown GC is always single-threaded, because it's + // possible that some of the Capabilities have no worker threads. + + if (gc_type == PENDING_GC_SEQ) + { + postEvent(cap, EVENT_REQUEST_SEQ_GC, 0, 0); + // single-threaded GC: grab all the capabilities + for (i=0; i < n_capabilities; i++) { + debugTrace(DEBUG_sched, "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; + waitForReturnCapability(&pcap, task); + if (pcap != &capabilities[i]) { + barf("scheduleDoGC: got the wrong capability"); + } + } + } } + else + { + // multi-threaded GC: make sure all the Capabilities donate one + // GC thread each. + postEvent(cap, EVENT_REQUEST_PAR_GC, 0, 0); + debugTrace(DEBUG_sched, "ready_to_gc, grabbing GC threads"); - waiting_for_gc = rtsFalse; + waitForGcThreads(cap); + } #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)) { - debugTrace(DEBUG_sched | DEBUG_stm, - "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); -#endif - } - } - } - } - } - // so this happens periodically: if (cap) scheduleCheckBlackHoles(cap); IF_DEBUG(scheduler, printAllThreads()); +delete_threads_and_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]); + if (sched_state == SCHED_INTERRUPTING) { + deleteAllThreads(cap); sched_state = SCHED_SHUTTING_DOWN; } + + heap_census = scheduleNeedHeapProfile(rtsTrue); - /* 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) + postEvent(cap, EVENT_GC_START, 0, 0); debugTrace(DEBUG_sched, "doing GC"); + // reset waiting_for_gc *before* GC, so that when the GC threads + // emerge they don't immediately re-enter the GC. + waiting_for_gc = 0; + GarbageCollect(force_major || heap_census, gc_type, cap); +#else + GarbageCollect(force_major || heap_census, 0, cap); #endif - 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]); - } + postEvent(cap, EVENT_GC_END, 0, 0); + + if (recent_activity == ACTIVITY_INACTIVE && force_major) + { + // We are doing a GC because the system has been idle for a + // timeslice and we need to check for deadlock. Record the + // fact that we've done a GC and turn off the timer signal; + // it will get re-enabled if we run any threads after the GC. + recent_activity = ACTIVITY_DONE_GC; + stopTimer(); } - if (cap) { - task->cap = cap; - } else { - task->cap = NULL; + else + { + // the GC might have taken long enough for the timer to set + // recent_activity = ACTIVITY_INACTIVE, but we aren't + // necessarily deadlocked: + recent_activity = ACTIVITY_YES; + } + +#if defined(THREADED_RTS) + if (gc_type == PENDING_GC_PAR) + { + releaseGCThreads(cap); } #endif -#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 */ + if (heap_census) { + debugTrace(DEBUG_sched, "performing heap census"); + heapCensus(); + performHeapProfile = rtsFalse; + } - return cap; -} + if (heap_overflow && sched_state < SCHED_INTERRUPTING) { + // GC set the heap_overflow flag, so we should proceed with + // an orderly shutdown now. Ultimately we want the main + // thread to return to its caller with HeapExhausted, at which + // point the caller should call hs_exit(). The first step is + // to delete all the threads. + // + // Another way to do this would be to raise an exception in + // the main thread, which we really should do because it gives + // the program a chance to clean up. But how do we find the + // main thread? It should presumably be the same one that + // gets ^C exceptions, but that's all done on the Haskell side + // (GHC.TopHandler). + sched_state = SCHED_INTERRUPTING; + goto delete_threads_and_gc; + } -/* --------------------------------------------------------------------------- - * rtsSupportsBoundThreads(): is the RTS built to support bound threads? - * used by Control.Concurrent for error checking. - * ------------------------------------------------------------------------- */ - -StgBool -rtsSupportsBoundThreads(void) -{ -#if defined(THREADED_RTS) - return rtsTrue; -#else - return rtsFalse; +#ifdef SPARKBALANCE + /* JB + Once we are all together... this would be the place to balance all + spark pools. No concurrent stealing or adding of new sparks can + occur. Should be defined in Sparks.c. */ + balanceSparkPoolsCaps(n_capabilities, capabilities); #endif -} -/* --------------------------------------------------------------------------- - * isThreadBound(tso): check whether tso is bound to an OS thread. - * ------------------------------------------------------------------------- */ - -StgBool -isThreadBound(StgTSO* tso USED_IF_THREADS) -{ #if defined(THREADED_RTS) - return (tso->bound != NULL); + if (gc_type == PENDING_GC_SEQ) { + // 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 - return rtsFalse; + + return cap; } /* --------------------------------------------------------------------------- * Singleton fork(). Do not copy any running threads. * ------------------------------------------------------------------------- */ -#if !defined(mingw32_HOST_OS) -#define FORKPROCESS_PRIMOP_SUPPORTED -#endif - -#ifdef FORKPROCESS_PRIMOP_SUPPORTED -static void -deleteThread_(Capability *cap, StgTSO *tso); -#endif -StgInt +pid_t forkProcess(HsStablePtr *entry #ifndef FORKPROCESS_PRIMOP_SUPPORTED STG_UNUSED @@ -2150,6 +1719,7 @@ forkProcess(HsStablePtr *entry pid_t pid; StgTSO* t,*next; Capability *cap; + nat s; #if defined(THREADED_RTS) if (RtsFlags.ParFlags.nNodes > 1) { @@ -2163,25 +1733,44 @@ forkProcess(HsStablePtr *entry // ToDo: for SMP, we should probably acquire *all* the capabilities cap = rts_lock(); + // no funny business: hold locks while we fork, otherwise if some + // other thread is holding a lock when the fork happens, the data + // structure protected by the lock will forever be in an + // inconsistent state in the child. See also #1391. + ACQUIRE_LOCK(&sched_mutex); + ACQUIRE_LOCK(&cap->lock); + ACQUIRE_LOCK(&cap->running_task->lock); + pid = fork(); if (pid) { // parent + RELEASE_LOCK(&sched_mutex); + RELEASE_LOCK(&cap->lock); + RELEASE_LOCK(&cap->running_task->lock); + // just return the pid rts_unlock(cap); return pid; } else { // child +#if defined(THREADED_RTS) + initMutex(&sched_mutex); + initMutex(&cap->lock); + initMutex(&cap->running_task->lock); +#endif + // 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) { + for (s = 0; s < total_steps; s++) { + for (t = all_steps[s].threads; t != END_TSO_QUEUE; t = next) { if (t->what_next == ThreadRelocated) { - next = t->link; + next = t->_link; } else { next = t->global_link; // don't allow threads to catch the ThreadKilled @@ -2189,6 +1778,7 @@ forkProcess(HsStablePtr *entry // threads may be evaluating thunks that we need later. deleteThread_(cap,t); } + } } // Empty the run queue. It seems tempting to let all the @@ -2202,14 +1792,19 @@ forkProcess(HsStablePtr *entry // don't exist now: cap->suspended_ccalling_tasks = NULL; - // Empty the all_threads list. Otherwise, the garbage + // Empty the threads lists. Otherwise, the garbage // collector may attempt to resurrect some of these threads. - all_threads = END_TSO_QUEUE; + for (s = 0; s < total_steps; s++) { + all_steps[s].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) { +#if defined(THREADED_RTS) + initMutex(&task->lock); // see #1391 +#endif discardTask(task); } } @@ -2223,6 +1818,11 @@ forkProcess(HsStablePtr *entry cap->returning_tasks_tl = NULL; #endif + // On Unix, all timers are reset in the child, so we need to start + // the timer again. + initTimer(); + startTimer(); + cap = rts_evalStableIO(cap, entry, NULL); // run the action rts_checkSchedStatus("forkProcess",cap); @@ -2243,26 +1843,32 @@ forkProcess(HsStablePtr *entry static void deleteAllThreads ( Capability *cap ) { - StgTSO* t, *next; - debugTrace(DEBUG_sched,"deleting all threads"); - for (t = all_threads; t != END_TSO_QUEUE; t = next) { - if (t->what_next == ThreadRelocated) { - next = t->link; - } else { - next = t->global_link; - deleteThread(cap,t); + // NOTE: only safe to call if we own all capabilities. + + StgTSO* t, *next; + nat s; + + debugTrace(DEBUG_sched,"deleting all threads"); + for (s = 0; s < total_steps; s++) { + for (t = all_steps[s].threads; t != END_TSO_QUEUE; t = next) { + 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 - // must not throw these away: the main thread(s) will be in there - // somewhere, and the main scheduler loop has to deal with it. - // Also, the run queue is the only thing keeping these threads from - // being GC'd, and we don't want the "main thread has been GC'd" panic. + // The run queue now contains a bunch of ThreadKilled threads. We + // must not throw these away: the main thread(s) will be in there + // somewhere, and the main scheduler loop has to deal with it. + // Also, the run queue is the only thing keeping these threads from + // being GC'd, and we don't want the "main thread has been GC'd" panic. #if !defined(THREADED_RTS) - ASSERT(blocked_queue_hd == END_TSO_QUEUE); - ASSERT(sleeping_queue == END_TSO_QUEUE); + ASSERT(blocked_queue_hd == END_TSO_QUEUE); + ASSERT(sleeping_queue == END_TSO_QUEUE); #endif } @@ -2317,9 +1923,17 @@ void * suspendThread (StgRegTable *reg) { Capability *cap; - int saved_errno = errno; + int saved_errno; StgTSO *tso; Task *task; +#if mingw32_HOST_OS + StgWord32 saved_winerror; +#endif + + saved_errno = errno; +#if mingw32_HOST_OS + saved_winerror = GetLastError(); +#endif /* assume that *reg is a pointer to the StgRegTable part of a Capability. */ @@ -2328,18 +1942,20 @@ suspendThread (StgRegTable *reg) task = cap->running_task; tso = cap->r.rCurrentTSO; + postEvent(cap, EVENT_STOP_THREAD, tso->id, THREAD_SUSPENDED_FOREIGN_CALL); debugTrace(DEBUG_sched, - "thread %d did a safe foreign call", - cap->r.rCurrentTSO->id); + "thread %lu did a safe foreign call", + (unsigned long)cap->r.rCurrentTSO->id); // XXX this might not be necessary --SDM tso->what_next = ThreadRunGHC; threadPaused(cap,tso); - if(tso->blocked_exceptions == NULL) { + if ((tso->flags & TSO_BLOCKEX) == 0) { tso->why_blocked = BlockedOnCCall; - tso->blocked_exceptions = END_TSO_QUEUE; + tso->flags |= TSO_BLOCKEX; + tso->flags &= ~TSO_INTERRUPTIBLE; } else { tso->why_blocked = BlockedOnCCall_NoUnblockExc; } @@ -2351,7 +1967,7 @@ suspendThread (StgRegTable *reg) suspendTask(cap,task); cap->in_haskell = rtsFalse; - releaseCapability_(cap); + releaseCapability_(cap,rtsFalse); RELEASE_LOCK(&cap->lock); @@ -2359,10 +1975,13 @@ suspendThread (StgRegTable *reg) /* Preparing to leave the RTS, so ensure there's a native thread/task waiting to take over. */ - debugTrace(DEBUG_sched, "thread %d: leaving RTS", tso->id); + debugTrace(DEBUG_sched, "thread %lu: leaving RTS", (unsigned long)tso->id); #endif errno = saved_errno; +#if mingw32_HOST_OS + SetLastError(saved_winerror); +#endif return task; } @@ -2371,8 +1990,16 @@ resumeThread (void *task_) { StgTSO *tso; Capability *cap; - int saved_errno = errno; Task *task = task_; + int saved_errno; +#if mingw32_HOST_OS + StgWord32 saved_winerror; +#endif + + saved_errno = errno; +#if mingw32_HOST_OS + saved_winerror = GetLastError(); +#endif cap = task->cap; // Wait for permission to re-enter the RTS with the result. @@ -2386,12 +2013,17 @@ resumeThread (void *task_) tso = task->suspended_tso; task->suspended_tso = NULL; - tso->link = END_TSO_QUEUE; - debugTrace(DEBUG_sched, "thread %d: re-entering RTS", tso->id); + tso->_link = END_TSO_QUEUE; // no write barrier reqd + + postEvent(cap, EVENT_RUN_THREAD, tso->id, 0); + debugTrace(DEBUG_sched, "thread %lu: re-entering RTS", (unsigned long)tso->id); if (tso->why_blocked == BlockedOnCCall) { - awakenBlockedQueue(cap,tso->blocked_exceptions); - tso->blocked_exceptions = NULL; + // avoid locking the TSO if we don't have to + if (tso->blocked_exceptions != END_TSO_QUEUE) { + awakenBlockedExceptionQueue(cap,tso); + } + tso->flags &= ~(TSO_BLOCKEX | TSO_INTERRUPTIBLE); } /* Reset blocking status */ @@ -2400,9 +2032,12 @@ resumeThread (void *task_) cap->r.rCurrentTSO = tso; cap->in_haskell = rtsTrue; errno = saved_errno; +#if mingw32_HOST_OS + SetLastError(saved_winerror); +#endif /* We might have GC'd, mark the TSO dirty again */ - dirtyTSO(tso); + dirty_TSO(cap,tso); IF_DEBUG(sanity, checkTSO(tso)); @@ -2410,300 +2045,6 @@ resumeThread (void *task_) } /* --------------------------------------------------------------------------- - * Comparing Thread ids. - * - * This is used from STG land in the implementation of the - * instances of Eq/Ord for ThreadIds. - * ------------------------------------------------------------------------ */ - -int -cmp_thread(StgPtr tso1, StgPtr tso2) -{ - StgThreadID id1 = ((StgTSO *)tso1)->id; - StgThreadID id2 = ((StgTSO *)tso2)->id; - - if (id1 < id2) return (-1); - if (id1 > id2) return 1; - return 0; -} - -/* --------------------------------------------------------------------------- - * Fetching the ThreadID from an StgTSO. - * - * This is used in the implementation of Show for ThreadIds. - * ------------------------------------------------------------------------ */ -int -rts_getThreadId(StgPtr tso) -{ - return ((StgTSO *)tso)->id; -} - -#ifdef DEBUG -void -labelThread(StgPtr tso, char *label) -{ - int len; - void *buf; - - /* Caveat: Once set, you can only set the thread name to "" */ - len = strlen(label)+1; - buf = stgMallocBytes(len * sizeof(char), "Schedule.c:labelThread()"); - strncpy(buf,label,len); - /* Update will free the old memory for us */ - updateThreadLabel(((StgTSO *)tso)->id,buf); -} -#endif /* DEBUG */ - -/* --------------------------------------------------------------------------- - Create a new thread. - - The new thread starts with the given stack size. Before the - scheduler can run, however, this thread needs to have a closure - (and possibly some arguments) pushed on its stack. See - pushClosure() in Schedule.h. - - createGenThread() and createIOThread() (in SchedAPI.h) are - convenient packaged versions of this function. - - currently pri (priority) is only used in a GRAN setup -- HWL - ------------------------------------------------------------------------ */ -#if defined(GRAN) -/* currently pri (priority) is only used in a GRAN setup -- HWL */ -StgTSO * -createThread(nat size, StgInt pri) -#else -StgTSO * -createThread(Capability *cap, nat size) -#endif -{ - StgTSO *tso; - nat stack_size; - - /* sched_mutex is *not* required */ - - /* First check whether we should create a thread at all */ -#if defined(PARALLEL_HASKELL) - /* check that no more than RtsFlags.ParFlags.maxThreads threads are created */ - if (advisory_thread_count >= RtsFlags.ParFlags.maxThreads) { - threadsIgnored++; - debugBelch("{createThread}Daq ghuH: refusing to create another thread; no more than %d threads allowed (currently %d)\n", - RtsFlags.ParFlags.maxThreads, advisory_thread_count); - return END_TSO_QUEUE; - } - threadsCreated++; -#endif - -#if defined(GRAN) - 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; - } - - 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); -#if defined(GRAN) - SET_GRAN_HDR(tso, ThisPE); -#endif - - // Always start with the compiled code evaluator - tso->what_next = ThreadRunGHC; - - 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; -#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; - - // ToDo: check this -#if defined(GRAN) - /* 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 - */ -#endif - -#if defined(GRAN) - 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. - */ - 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... -#endif - -#if defined(GRAN) - tso->gran.pri = pri; -# if defined(DEBUG) - 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(PARALLEL_HASKELL) -# if defined(DEBUG) - 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; -#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(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) - debugTrace(GRAN_DEBUG_pri, - "==__ schedule: Created TSO %d (%p);", - CurrentProc, tso, tso->id); -#elif defined(PARALLEL_HASKELL) - debugTrace(PAR_DEBUG_verbose, - "==__ schedule: Created TSO %d (%p); %d threads active", - (long)tso->id, tso, advisory_thread_count); -#else - debugTrace(DEBUG_sched, - "created thread %ld, stack size = %lx words", - (long)tso->id, (long)tso->stack_size); -#endif - return tso; -} - -#if defined(PAR) -/* RFP: - all parallel thread creation calls should fall through the following routine. -*/ -StgTSO * -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)", - RtsFlags.ParFlags.maxThreads, advisory_thread_count); - return END_TSO_QUEUE; - } - else - { threadsCreated++; - tso = createThread(RtsFlags.GcFlags.initialStkSize); - if (tso==END_TSO_QUEUE) - barf("createSparkThread: Cannot create TSO"); -#if defined(DIST) - tso->priority = AdvisoryPriority; -#endif - pushClosure(tso,spark); - addToRunQueue(tso); - advisory_thread_count++; // JB: TAKE CARE OF THIS COUNTER! BUGGY - } - return tso; -} -#endif - -/* - Turn a spark into a thread. - ToDo: fix for SMP (needs to acquire SCHED_MUTEX!) -*/ -#if 0 -StgTSO * -activateSpark (rtsSpark spark) -{ - StgTSO *tso; - - 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))); - } - // ToDo: fwd info on local/global spark to thread -- HWL - // tso->gran.exported = spark->exported; - // tso->gran.locked = !spark->global; - // tso->gran.sparkname = spark->name; - - return tso; -} -#endif - -/* --------------------------------------------------------------------------- * scheduleThread() * * scheduleThread puts a thread on the end of the runnable queue. @@ -2731,12 +2072,8 @@ scheduleThreadOn(Capability *cap, StgWord cpu USED_IF_THREADS, StgTSO *tso) 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); + postEvent (cap, EVENT_MIGRATE_THREAD, tso->id, capabilities[cpu].no); + wakeupThreadOnCapability(cap, &capabilities[cpu], tso); } #else appendToRunQueue(cap,tso); @@ -2762,21 +2099,14 @@ scheduleWaitThread (StgTSO* tso, /*[out]*/HaskellObj* ret, Capability *cap) appendToRunQueue(cap,tso); - debugTrace(DEBUG_sched, "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 + debugTrace(DEBUG_sched, "new bound thread (%lu)", (unsigned long)tso->id); cap = schedule(cap,task); ASSERT(task->stat != NoStatus); ASSERT_FULL_CAPABILITY_INVARIANTS(cap,task); - debugTrace(DEBUG_sched, "bound thread (%d) finished", task->tso->id); + debugTrace(DEBUG_sched, "bound thread (%lu) finished", (unsigned long)task->tso->id); return cap; } @@ -2785,7 +2115,7 @@ scheduleWaitThread (StgTSO* tso, /*[out]*/HaskellObj* ret, Capability *cap) * ------------------------------------------------------------------------- */ #if defined(THREADED_RTS) -void +void OSThreadProcAttr workerStart(Task *task) { Capability *cap; @@ -2795,15 +2125,32 @@ workerStart(Task *task) cap = task->cap; RELEASE_LOCK(&task->lock); + if (RtsFlags.ParFlags.setAffinity) { + setThreadAffinity(cap->no, n_capabilities); + } + // set the thread-local pointer to the Task: taskEnter(task); // schedule() runs without a lock. cap = schedule(cap,task); - // On exit from schedule(), we have a Capability. - releaseCapability(cap); + // On exit from schedule(), we have a Capability, but possibly not + // the same one we started with. + + // During shutdown, the requirement is that after all the + // Capabilities are shut down, all workers that are shutting down + // have finished workerTaskStop(). This is why we hold on to + // cap->lock until we've finished workerTaskStop() below. + // + // There may be workers still involved in foreign calls; those + // will just block in waitForReturnCapability() because the + // Capability has been shut down. + // + ACQUIRE_LOCK(&cap->lock); + releaseCapability_(cap,rtsFalse); workerTaskStop(task); + RELEASE_LOCK(&cap->lock); } #endif @@ -2819,32 +2166,17 @@ workerStart(Task *task) void 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; - } -#elif !defined(THREADED_RTS) +#if !defined(THREADED_RTS) blocked_queue_hd = END_TSO_QUEUE; blocked_queue_tl = END_TSO_QUEUE; sleeping_queue = END_TSO_QUEUE; #endif blackhole_queue = END_TSO_QUEUE; - all_threads = END_TSO_QUEUE; - context_switch = 0; sched_state = SCHED_RUNNING; + recent_activity = ACTIVITY_YES; - RtsFlags.ConcFlags.ctxtSwitchTicks = - RtsFlags.ConcFlags.ctxtSwitchTime / TICK_MILLISECS; - #if defined(THREADED_RTS) /* Initialise the mutex and condition variables used by * the scheduler. */ @@ -2884,26 +2216,30 @@ initScheduler(void) } #endif - trace(TRACE_sched, "start: %d capabilities", n_capabilities); - RELEASE_LOCK(&sched_mutex); } void -exitScheduler( void ) +exitScheduler( + rtsBool wait_foreign +#if !defined(THREADED_RTS) + __attribute__((unused)) +#endif +) + /* see Capability.c, shutdownCapability() */ { Task *task = NULL; -#if defined(THREADED_RTS) ACQUIRE_LOCK(&sched_mutex); task = newBoundTask(); RELEASE_LOCK(&sched_mutex); -#endif // If we haven't killed all the threads yet, do it now. if (sched_state < SCHED_SHUTTING_DOWN) { sched_state = SCHED_INTERRUPTING; - scheduleDoGC(NULL,task,rtsFalse,GetRoots); + waitForReturnCapability(&task->cap,task); + scheduleDoGC(task->cap,task,rtsFalse); + releaseCapability(task->cap); } sched_state = SCHED_SHUTTING_DOWN; @@ -2912,90 +2248,35 @@ exitScheduler( void ) nat i; for (i = 0; i < n_capabilities; i++) { - shutdownCapability(&capabilities[i], task); + shutdownCapability(&capabilities[i], task, wait_foreign); } boundTaskExiting(task); - stopTaskManager(); } #endif } -/* --------------------------------------------------------------------------- - Where are the roots that we know about? - - - all the threads on the runnable queue - - all the threads on the blocked queue - - all the threads on the sleeping queue - - all the thread currently executing a _ccall_GC - - all the "main threads" - - ------------------------------------------------------------------------ */ - -/* This has to be protected either by the scheduler monitor, or by the - garbage collection monitor (probably the latter). - KH @ 25/10/99 -*/ - void -GetRoots( evac_fn evac ) +freeScheduler( void ) { - nat i; - Capability *cap; - Task *task; + nat still_running; -#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]); + ACQUIRE_LOCK(&sched_mutex); + still_running = freeTaskManager(); + // We can only free the Capabilities if there are no Tasks still + // running. We might have a Task about to return from a foreign + // call into waitForReturnCapability(), for example (actually, + // this should be the *only* thing that a still-running Task can + // do at this point, and it will block waiting for the + // Capability). + if (still_running == 0) { + freeCapabilities(); + if (n_capabilities != 1) { + stgFree(capabilities); + } } - - markEventQueue(); - -#else /* !GRAN */ - - for (i = 0; i < n_capabilities; i++) { - cap = &capabilities[i]; - evac((StgClosure **)(void *)&cap->run_queue_hd); - evac((StgClosure **)(void *)&cap->run_queue_tl); + RELEASE_LOCK(&sched_mutex); #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) { - debugTrace(DEBUG_sched, - "evac'ing suspended TSO %d", task->suspended_tso->id); - evac((StgClosure **)(void *)&task->suspended_tso); - } - - } - - -#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); + closeMutex(&sched_mutex); #endif } @@ -3005,53 +2286,36 @@ GetRoots( evac_fn evac ) This is the interface to the garbage collector from Haskell land. We provide this so that external C code can allocate and garbage collect when called from Haskell via _ccall_GC. - - It might be useful to provide an interface whereby the programmer - can specify more roots (ToDo). - - This needs to be protected by the GC condition variable above. KH. -------------------------------------------------------------------------- */ -static void (*extra_roots)(evac_fn); - static void -performGC_(rtsBool force_major, void (*get_roots)(evac_fn)) +performGC_(rtsBool force_major) { Task *task; + // We must grab a new Task here, because the existing Task may be // associated with a particular Capability, and chained onto the // suspended_ccalling_tasks queue. ACQUIRE_LOCK(&sched_mutex); task = newBoundTask(); RELEASE_LOCK(&sched_mutex); - scheduleDoGC(NULL,task,force_major, get_roots); + + waitForReturnCapability(&task->cap,task); + scheduleDoGC(task->cap,task,force_major); + releaseCapability(task->cap); boundTaskExiting(task); } void performGC(void) { - performGC_(rtsFalse, GetRoots); + performGC_(rtsFalse); } void performMajorGC(void) { - performGC_(rtsTrue, GetRoots); -} - -static void -AllRoots(evac_fn evac) -{ - GetRoots(evac); // the scheduler's roots - extra_roots(evac); // the user's roots -} - -void -performGCWithRoots(void (*get_roots)(evac_fn)) -{ - extra_roots = get_roots; - performGC_(rtsFalse, AllRoots); + performGC_(rtsTrue); } /* ----------------------------------------------------------------------------- @@ -3072,36 +2336,54 @@ threadStackOverflow(Capability *cap, StgTSO *tso) StgTSO *dest; IF_DEBUG(sanity,checkTSO(tso)); - if (tso->stack_size >= tso->max_stack_size) { + + // don't allow throwTo() to modify the blocked_exceptions queue + // while we are moving the TSO: + lockClosure((StgClosure *)tso); + + if (tso->stack_size >= tso->max_stack_size && !(tso->flags & TSO_BLOCKEX)) { + // NB. never raise a StackOverflow exception if the thread is + // inside Control.Exceptino.block. It is impractical to protect + // against stack overflow exceptions, since virtually anything + // can raise one (even 'catch'), so this is the only sensible + // thing to do here. See bug #767. debugTrace(DEBUG_gc, - "threadStackOverflow of TSO %ld (%p): stack too large (now %ld; max is %ld)\n", + "threadStackOverflow of TSO %ld (%p): stack too large (now %ld; max is %ld)", (long)tso->id, tso, (long)tso->stack_size, (long)tso->max_stack_size); IF_DEBUG(gc, /* If we're debugging, just print out the top of the stack */ printStackChunk(tso->sp, stg_min(tso->stack+tso->stack_size, tso->sp+64))); - /* Send this thread the StackOverflow exception */ - raiseAsync(cap, tso, (StgClosure *)stackOverflow_closure); - return tso; + // Send this thread the StackOverflow exception + unlockTSO(tso); + throwToSingleThreaded(cap, tso, (StgClosure *)stackOverflow_closure); + return tso; } /* Try to double the current stack size. If that takes us over the - * maximum stack size for this thread, then use the maximum instead. - * Finally round up so the TSO ends up as a whole number of blocks. + * maximum stack size for this thread, then use the maximum instead + * (that is, unless we're already at or over the max size and we + * can't raise the StackOverflow exception (see above), in which + * case just double the size). 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); + if (tso->stack_size >= tso->max_stack_size) { + new_stack_size = tso->stack_size * 2; + } else { + new_stack_size = stg_min(tso->stack_size * 2, tso->max_stack_size); + } 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; debugTrace(DEBUG_sched, - "increasing stack size from %ld words to %d.\n", + "increasing stack size from %ld words to %d.", (long)tso->stack_size, new_stack_size); - dest = (StgTSO *)allocate(new_tso_size); + dest = (StgTSO *)allocateLocal(cap,new_tso_size); TICK_ALLOC_TSO(new_stack_size,0); /* copy the TSO block and the old stack into the new area */ @@ -3122,7 +2404,7 @@ threadStackOverflow(Capability *cap, StgTSO *tso) * dead TSO's stack. */ tso->what_next = ThreadRelocated; - tso->link = dest; + setTSOLink(cap,tso,dest); tso->sp = (P_)&(tso->stack[tso->stack_size]); tso->why_blocked = NotBlocked; @@ -3133,7 +2415,10 @@ threadStackOverflow(Capability *cap, StgTSO *tso) printStackChunk(tso->sp, stg_min(tso->stack+tso->stack_size, tso->sp+64))); - IF_DEBUG(sanity,checkTSO(tso)); + unlockTSO(dest); + unlockTSO(tso); + + IF_DEBUG(sanity,checkTSO(dest)); #if 0 IF_DEBUG(scheduler,printTSO(dest)); #endif @@ -3141,300 +2426,55 @@ threadStackOverflow(Capability *cap, StgTSO *tso) return dest; } -/* --------------------------------------------------------------------------- - Wake up a queue that was blocked on some resource. - ------------------------------------------------------------------------ */ - -#if defined(GRAN) -STATIC_INLINE void -unblockCount ( StgBlockingQueueElement *bqe, StgClosure *node ) -{ -} -#elif defined(PARALLEL_HASKELL) -STATIC_INLINE void -unblockCount ( StgBlockingQueueElement *bqe, StgClosure *node ) +static StgTSO * +threadStackUnderflow (Task *task STG_UNUSED, StgTSO *tso) { - /* write RESUME events to log file and - update blocked and fetch time (depending on type of the orig closure) */ - if (RtsFlags.ParFlags.ParStats.Full) { - DumpRawGranEvent(CURRENT_PROC, CURRENT_PROC, - GR_RESUMEQ, ((StgTSO *)bqe), ((StgTSO *)bqe)->block_info.closure, - 0, 0 /* spark_queue_len(ADVISORY_POOL) */); - if (emptyRunQueue()) - emitSchedule = rtsTrue; - - switch (get_itbl(node)->type) { - case FETCH_ME_BQ: - ((StgTSO *)bqe)->par.fetchtime += CURRENT_TIME-((StgTSO *)bqe)->par.blockedat; - break; - case RBH: - case FETCH_ME: - case BLACKHOLE_BQ: - ((StgTSO *)bqe)->par.blocktime += CURRENT_TIME-((StgTSO *)bqe)->par.blockedat; - break; -#ifdef DIST - case MVAR: - break; -#endif - default: - barf("{unblockOne}Daq Qagh: unexpected closure in blocking queue"); - } - } -} -#endif + bdescr *bd, *new_bd; + lnat free_w, tso_size_w; + StgTSO *new_tso; -#if defined(GRAN) -StgBlockingQueueElement * -unblockOne(StgBlockingQueueElement *bqe, StgClosure *node) -{ - StgTSO *tso; - PEs node_loc, tso_loc; - - node_loc = where_is(node); // should be lifted out of loop - tso = (StgTSO *)bqe; // wastes an assignment to get the type right - tso_loc = where_is((StgClosure *)tso); - if (IS_LOCAL_TO(PROCS(node),tso_loc)) { // TSO is local - /* !fake_fetch => TSO is on CurrentProc is same as IS_LOCAL_TO */ - ASSERT(CurrentProc!=node_loc || tso_loc==CurrentProc); - CurrentTime[CurrentProc] += RtsFlags.GranFlags.Costs.lunblocktime; - // insertThread(tso, node_loc); - new_event(tso_loc, tso_loc, CurrentTime[CurrentProc], - ResumeThread, - tso, node, (rtsSpark*)NULL); - tso->link = END_TSO_QUEUE; // overwrite link just to be sure - // len_local++; - // len++; - } else { // TSO is remote (actually should be FMBQ) - CurrentTime[CurrentProc] += RtsFlags.GranFlags.Costs.mpacktime + - RtsFlags.GranFlags.Costs.gunblocktime + - RtsFlags.GranFlags.Costs.latency; - new_event(tso_loc, CurrentProc, CurrentTime[CurrentProc], - UnblockThread, - tso, node, (rtsSpark*)NULL); - tso->link = END_TSO_QUEUE; // overwrite link just to be sure - // len++; - } - /* the thread-queue-overhead is accounted for in either Resume or UnblockThread */ - IF_GRAN_DEBUG(bq, - debugBelch(" %s TSO %d (%p) [PE %d] (block_info.closure=%p) (next=%p) ,", - (node_loc==tso_loc ? "Local" : "Global"), - tso->id, tso, CurrentProc, tso->block_info.closure, tso->link)); - tso->block_info.closure = NULL; - debugTrace(DEBUG_sched, "-- waking up thread %ld (%p)\n", - tso->id, tso)); -} -#elif defined(PARALLEL_HASKELL) -StgBlockingQueueElement * -unblockOne(StgBlockingQueueElement *bqe, StgClosure *node) -{ - StgBlockingQueueElement *next; - - switch (get_itbl(bqe)->type) { - case TSO: - ASSERT(((StgTSO *)bqe)->why_blocked != NotBlocked); - /* if it's a TSO just push it onto the run_queue */ - next = bqe->link; - ((StgTSO *)bqe)->link = END_TSO_QUEUE; // debugging? - APPEND_TO_RUN_QUEUE((StgTSO *)bqe); - threadRunnable(); - unblockCount(bqe, node); - /* reset blocking status after dumping event */ - ((StgTSO *)bqe)->why_blocked = NotBlocked; - break; - - case BLOCKED_FETCH: - /* if it's a BLOCKED_FETCH put it on the PendingFetches list */ - next = bqe->link; - bqe->link = (StgBlockingQueueElement *)PendingFetches; - PendingFetches = (StgBlockedFetch *)bqe; - break; - -# if defined(DEBUG) - /* can ignore this case in a non-debugging setup; - see comments on RBHSave closures above */ - case CONSTR: - /* check that the closure is an RBHSave closure */ - ASSERT(get_itbl((StgClosure *)bqe) == &stg_RBH_Save_0_info || - get_itbl((StgClosure *)bqe) == &stg_RBH_Save_1_info || - get_itbl((StgClosure *)bqe) == &stg_RBH_Save_2_info); - break; + tso_size_w = tso_sizeW(tso); - default: - 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 + if (tso_size_w < MBLOCK_SIZE_W || + (nat)(tso->stack + tso->stack_size - tso->sp) > tso->stack_size / 4) + { + return tso; } - IF_PAR_DEBUG(bq, debugBelch(", %p (%s)\n", bqe, info_type((StgClosure*)bqe))); - return next; -} -#endif -StgTSO * -unblockOne(Capability *cap, StgTSO *tso) -{ - StgTSO *next; + // don't allow throwTo() to modify the blocked_exceptions queue + // while we are moving the TSO: + lockClosure((StgClosure *)tso); - ASSERT(get_itbl(tso)->type == TSO); - ASSERT(tso->why_blocked != NotBlocked); + // this is the number of words we'll free + free_w = round_to_mblocks(tso_size_w/2); - tso->why_blocked = NotBlocked; - next = tso->link; - tso->link = END_TSO_QUEUE; + bd = Bdescr((StgPtr)tso); + new_bd = splitLargeBlock(bd, free_w / BLOCK_SIZE_W); + bd->free = bd->start + TSO_STRUCT_SIZEW; -#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 - appendToRunQueue(cap,tso); - context_switch = 1; -#endif - - debugTrace(DEBUG_sched, - "waking up thread %ld on cap %d", - (long)tso->id, tso->cap->no); - - return next; -} - - -#if defined(GRAN) -void -awakenBlockedQueue(StgBlockingQueueElement *q, StgClosure *node) -{ - StgBlockingQueueElement *bqe; - PEs node_loc; - nat len = 0; - - IF_GRAN_DEBUG(bq, - debugBelch("##-_ AwBQ for node %p on PE %d @ %ld by TSO %d (%p): \n", \ - node, CurrentProc, CurrentTime[CurrentProc], - CurrentTSO->id, CurrentTSO)); + new_tso = (StgTSO *)new_bd->start; + memcpy(new_tso,tso,TSO_STRUCT_SIZE); + new_tso->stack_size = new_bd->free - new_tso->stack; - node_loc = where_is(node); + debugTrace(DEBUG_sched, "thread %ld: reducing TSO size from %lu words to %lu", + (long)tso->id, tso_size_w, tso_sizeW(new_tso)); - ASSERT(q == END_BQ_QUEUE || - get_itbl(q)->type == TSO || // q is either a TSO or an RBHSave - get_itbl(q)->type == CONSTR); // closure (type constructor) - ASSERT(is_unique(node)); + tso->what_next = ThreadRelocated; + tso->_link = new_tso; // no write barrier reqd: same generation - /* FAKE FETCH: magically copy the node to the tso's proc; - no Fetch necessary because in reality the node should not have been - moved to the other PE in the first place - */ - if (CurrentProc!=node_loc) { - IF_GRAN_DEBUG(bq, - debugBelch("## node %p is on PE %d but CurrentProc is %d (TSO %d); assuming fake fetch and adjusting bitmask (old: %#x)\n", - node, node_loc, CurrentProc, CurrentTSO->id, - // CurrentTSO, where_is(CurrentTSO), - node->header.gran.procs)); - node->header.gran.procs = (node->header.gran.procs) | PE_NUMBER(CurrentProc); - IF_GRAN_DEBUG(bq, - debugBelch("## new bitmask of node %p is %#x\n", - node, node->header.gran.procs)); - if (RtsFlags.GranFlags.GranSimStats.Global) { - globalGranStats.tot_fake_fetches++; + // The TSO attached to this Task may have moved, so update the + // pointer to it. + if (task->tso == tso) { + task->tso = new_tso; } - } - bqe = q; - // ToDo: check: ASSERT(CurrentProc==node_loc); - while (get_itbl(bqe)->type==TSO) { // q != END_TSO_QUEUE) { - //next = bqe->link; - /* - bqe points to the current element in the queue - next points to the next element in the queue - */ - //tso = (StgTSO *)bqe; // wastes an assignment to get the type right - //tso_loc = where_is(tso); - len++; - bqe = unblockOne(bqe, node); - } + unlockTSO(new_tso); + unlockTSO(tso); - /* if this is the BQ of an RBH, we have to put back the info ripped out of - the closure to make room for the anchor of the BQ */ - if (bqe!=END_BQ_QUEUE) { - ASSERT(get_itbl(node)->type == RBH && get_itbl(bqe)->type == CONSTR); - /* - ASSERT((info_ptr==&RBH_Save_0_info) || - (info_ptr==&RBH_Save_1_info) || - (info_ptr==&RBH_Save_2_info)); - */ - /* cf. convertToRBH in RBH.c for writing the RBHSave closure */ - ((StgRBH *)node)->blocking_queue = (StgBlockingQueueElement *)((StgRBHSave *)bqe)->payload[0]; - ((StgRBH *)node)->mut_link = (StgMutClosure *)((StgRBHSave *)bqe)->payload[1]; - - IF_GRAN_DEBUG(bq, - debugBelch("## Filled in RBH_Save for %p (%s) at end of AwBQ\n", - node, info_type(node))); - } + IF_DEBUG(sanity,checkTSO(new_tso)); - /* statistics gathering */ - if (RtsFlags.GranFlags.GranSimStats.Global) { - // globalGranStats.tot_bq_processing_time += bq_processing_time; - globalGranStats.tot_bq_len += len; // total length of all bqs awakened - // globalGranStats.tot_bq_len_local += len_local; // same for local TSOs only - globalGranStats.tot_awbq++; // total no. of bqs awakened - } - IF_GRAN_DEBUG(bq, - debugBelch("## BQ Stats of %p: [%d entries] %s\n", - node, len, (bqe!=END_BQ_QUEUE) ? "RBH" : "")); + return new_tso; } -#elif defined(PARALLEL_HASKELL) -void -awakenBlockedQueue(StgBlockingQueueElement *q, StgClosure *node) -{ - StgBlockingQueueElement *bqe; - - IF_PAR_DEBUG(verbose, - debugBelch("##-_ AwBQ for node %p on [%x]: \n", - node, mytid)); -#ifdef DIST - //RFP - if(get_itbl(q)->type == CONSTR || q==END_BQ_QUEUE) { - IF_PAR_DEBUG(verbose, debugBelch("## ... nothing to unblock so lets just return. RFP (BUG?)\n")); - return; - } -#endif - - ASSERT(q == END_BQ_QUEUE || - get_itbl(q)->type == TSO || - get_itbl(q)->type == BLOCKED_FETCH || - get_itbl(q)->type == CONSTR); - - bqe = q; - while (get_itbl(bqe)->type==TSO || - get_itbl(bqe)->type==BLOCKED_FETCH) { - bqe = unblockOne(bqe, node); - } -} - -#else /* !GRAN && !PARALLEL_HASKELL */ - -void -awakenBlockedQueue(Capability *cap, StgTSO *tso) -{ - if (tso == NULL) return; // hack; see bug #1235728, and comments in - // Exception.cmm - while (tso != END_TSO_QUEUE) { - tso = unblockOne(cap,tso); - } -} -#endif /* --------------------------------------------------------------------------- Interrupt execution @@ -3445,7 +2485,7 @@ void interruptStgRts(void) { sched_state = SCHED_INTERRUPTING; - context_switch = 1; + setContextSwitches(); wakeUpRts(); } @@ -3466,329 +2506,12 @@ void wakeUpRts(void) { #if defined(THREADED_RTS) -#if !defined(mingw32_HOST_OS) // This forces the IO Manager thread to wakeup, which will // in turn ensure that some OS thread wakes up and runs the // scheduler loop, which will cause a GC and deadlock check. ioManagerWakeup(); -#else - // On Windows this might be safe enough, because we aren't - // in a signal handler. Later we should use the IO Manager, - // though. - prodOneCapability(); -#endif -#endif -} - -/* ----------------------------------------------------------------------------- - Unblock a thread - - This is for use when we raise an exception in another thread, which - may be blocked. - This has nothing to do with the UnblockThread event in GranSim. -- HWL - -------------------------------------------------------------------------- */ - -#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 - long live polymorphism! - - Locks: sched_mutex is held upon entry and exit. - -*/ -static void -unblockThread(Capability *cap, StgTSO *tso) -{ - StgBlockingQueueElement *t, **last; - - switch (tso->why_blocked) { - - case NotBlocked: - return; /* not blocked */ - - case BlockedOnSTM: - // Be careful: nothing to do here! We tell the scheduler that the thread - // is runnable and we leave it to the stack-walking code to abort the - // transaction while unwinding the stack. We should perhaps have a debugging - // test to make sure that this really happens and that the 'zombie' transaction - // does not get committed. - goto done; - - case BlockedOnMVar: - ASSERT(get_itbl(tso->block_info.closure)->type == MVAR); - { - StgBlockingQueueElement *last_tso = END_BQ_QUEUE; - StgMVar *mvar = (StgMVar *)(tso->block_info.closure); - - last = (StgBlockingQueueElement **)&mvar->head; - for (t = (StgBlockingQueueElement *)mvar->head; - t != END_BQ_QUEUE; - last = &t->link, last_tso = t, t = t->link) { - if (t == (StgBlockingQueueElement *)tso) { - *last = (StgBlockingQueueElement *)tso->link; - if (mvar->tail == tso) { - mvar->tail = (StgTSO *)last_tso; - } - goto done; - } - } - barf("unblockThread (MVAR): TSO not found"); - } - - 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_BQ_QUEUE; - last = &t->link, t = t->link) { - if (t == (StgBlockingQueueElement *)tso) { - *last = (StgBlockingQueueElement *)tso->link; - goto done; - } - } - barf("unblockThread (BLACKHOLE): TSO not found"); - } - - case BlockedOnException: - { - StgTSO *target = tso->block_info.tso; - - ASSERT(get_itbl(target)->type == TSO); - - if (target->what_next == ThreadRelocated) { - target = target->link; - ASSERT(get_itbl(target)->type == TSO); - } - - ASSERT(target->blocked_exceptions != NULL); - - last = (StgBlockingQueueElement **)&target->blocked_exceptions; - for (t = (StgBlockingQueueElement *)target->blocked_exceptions; - t != END_BQ_QUEUE; - last = &t->link, t = t->link) { - ASSERT(get_itbl(t)->type == TSO); - if (t == (StgBlockingQueueElement *)tso) { - *last = (StgBlockingQueueElement *)tso->link; - goto done; - } - } - barf("unblockThread (Exception): TSO not found"); - } - - case BlockedOnRead: - case BlockedOnWrite: -#if defined(mingw32_HOST_OS) - case BlockedOnDoProc: -#endif - { - /* take TSO off blocked_queue */ - StgBlockingQueueElement *prev = NULL; - for (t = (StgBlockingQueueElement *)blocked_queue_hd; t != END_BQ_QUEUE; - prev = t, t = t->link) { - if (t == (StgBlockingQueueElement *)tso) { - if (prev == NULL) { - blocked_queue_hd = (StgTSO *)t->link; - if ((StgBlockingQueueElement *)blocked_queue_tl == t) { - blocked_queue_tl = END_TSO_QUEUE; - } - } else { - prev->link = t->link; - if ((StgBlockingQueueElement *)blocked_queue_tl == t) { - 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; - } - } - barf("unblockThread (I/O): TSO not found"); - } - - case BlockedOnDelay: - { - /* take TSO off sleeping_queue */ - StgBlockingQueueElement *prev = NULL; - for (t = (StgBlockingQueueElement *)sleeping_queue; t != END_BQ_QUEUE; - prev = t, t = t->link) { - if (t == (StgBlockingQueueElement *)tso) { - if (prev == NULL) { - sleeping_queue = (StgTSO *)t->link; - } else { - prev->link = t->link; - } - goto done; - } - } - barf("unblockThread (delay): TSO not found"); - } - - default: - barf("unblockThread"); - } - - done: - tso->link = END_TSO_QUEUE; - tso->why_blocked = NotBlocked; - tso->block_info.closure = NULL; - pushOnRunQueue(cap,tso); -} -#else -static void -unblockThread(Capability *cap, StgTSO *tso) -{ - StgTSO *t, **last; - - /* To avoid locking unnecessarily. */ - if (tso->why_blocked == NotBlocked) { - return; - } - - switch (tso->why_blocked) { - - case BlockedOnSTM: - // Be careful: nothing to do here! We tell the scheduler that the thread - // is runnable and we leave it to the stack-walking code to abort the - // transaction while unwinding the stack. We should perhaps have a debugging - // test to make sure that this really happens and that the 'zombie' transaction - // does not get committed. - goto done; - - case BlockedOnMVar: - ASSERT(get_itbl(tso->block_info.closure)->type == MVAR); - { - StgTSO *last_tso = END_TSO_QUEUE; - StgMVar *mvar = (StgMVar *)(tso->block_info.closure); - - last = &mvar->head; - for (t = mvar->head; t != END_TSO_QUEUE; - last = &t->link, last_tso = t, t = t->link) { - if (t == tso) { - *last = tso->link; - if (mvar->tail == tso) { - mvar->tail = last_tso; - } - goto done; - } - } - barf("unblockThread (MVAR): TSO not found"); - } - - case BlockedOnBlackHole: - { - last = &blackhole_queue; - for (t = blackhole_queue; t != END_TSO_QUEUE; - last = &t->link, t = t->link) { - if (t == tso) { - *last = tso->link; - goto done; - } - } - barf("unblockThread (BLACKHOLE): TSO not found"); - } - - case BlockedOnException: - { - StgTSO *target = tso->block_info.tso; - - ASSERT(get_itbl(target)->type == TSO); - - while (target->what_next == ThreadRelocated) { - target = target->link; - ASSERT(get_itbl(target)->type == TSO); - } - - ASSERT(target->blocked_exceptions != NULL); - - last = &target->blocked_exceptions; - for (t = target->blocked_exceptions; t != END_TSO_QUEUE; - last = &t->link, t = t->link) { - ASSERT(get_itbl(t)->type == TSO); - if (t == tso) { - *last = tso->link; - goto done; - } - } - barf("unblockThread (Exception): TSO not found"); - } - -#if !defined(THREADED_RTS) - case BlockedOnRead: - case BlockedOnWrite: -#if defined(mingw32_HOST_OS) - case BlockedOnDoProc: -#endif - { - StgTSO *prev = NULL; - for (t = blocked_queue_hd; t != END_TSO_QUEUE; - prev = t, t = t->link) { - if (t == tso) { - if (prev == NULL) { - blocked_queue_hd = t->link; - if (blocked_queue_tl == t) { - blocked_queue_tl = END_TSO_QUEUE; - } - } else { - prev->link = t->link; - if (blocked_queue_tl == t) { - 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; - } - } - barf("unblockThread (I/O): TSO not found"); - } - - case BlockedOnDelay: - { - StgTSO *prev = NULL; - for (t = sleeping_queue; t != END_TSO_QUEUE; - prev = t, t = t->link) { - if (t == tso) { - if (prev == NULL) { - sleeping_queue = t->link; - } else { - prev->link = t->link; - } - goto done; - } - } - 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() @@ -3821,18 +2544,20 @@ checkBlackHoles (Capability *cap) prev = &blackhole_queue; t = blackhole_queue; while (t != END_TSO_QUEUE) { + if (t->what_next == ThreadRelocated) { + t = t->_link; + continue; + } ASSERT(t->why_blocked == BlockedOnBlackHole); - type = get_itbl(t->block_info.closure)->type; + type = get_itbl(UNTAG_CLOSURE(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; + prev = &t->_link; + t = t->_link; } } @@ -3840,264 +2565,6 @@ checkBlackHoles (Capability *cap) } /* ----------------------------------------------------------------------------- - * raiseAsync() - * - * The following function implements the magic for raising an - * asynchronous exception in an existing thread. - * - * We first remove the thread from any queue on which it might be - * blocked. The possible blockages are MVARs and BLACKHOLE_BQs. - * - * We strip the stack down to the innermost CATCH_FRAME, building - * thunks in the heap for all the active computations, so they can - * be restarted if necessary. When we reach a CATCH_FRAME, we build - * an application of the handler to the exception, and push it on - * the top of the stack. - * - * How exactly do we save all the active computations? We create an - * AP_STACK for every UpdateFrame on the stack. Entering one of these - * AP_STACKs pushes everything from the corresponding update frame - * upwards onto the stack. (Actually, it pushes everything up to the - * next update frame plus a pointer to the next AP_STACK object. - * Entering the next AP_STACK object pushes more onto the stack until we - * reach the last AP_STACK object - at which point the stack should look - * exactly as it did when we killed the TSO and we can continue - * execution by entering the closure on top of the stack. - * - * We can also kill a thread entirely - this happens if either (a) the - * exception passed to raiseAsync is NULL, or (b) there's no - * CATCH_FRAME on the stack. In either case, we strip the entire - * stack and replace the thread with a zombie. - * - * 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 -raiseAsync(Capability *cap, StgTSO *tso, StgClosure *exception) -{ - raiseAsync_(cap, tso, exception, rtsFalse, NULL); -} - -void -suspendComputation(Capability *cap, StgTSO *tso, StgPtr stop_here) -{ - raiseAsync_(cap, tso, NULL, rtsFalse, stop_here); -} - -static void -raiseAsync_(Capability *cap, StgTSO *tso, StgClosure *exception, - rtsBool stop_at_atomically, StgPtr stop_here) -{ - StgRetInfoTable *info; - StgPtr sp, frame; - nat i; - - // Thread already dead? - if (tso->what_next == ThreadComplete || tso->what_next == ThreadKilled) { - return; - } - - debugTrace(DEBUG_sched, - "raising exception in thread %ld.", (long)tso->id); - - // Remove it from any blocking queues - unblockThread(cap,tso); - - // mark it dirty; we're about to change its stack. - dirtyTSO(tso); - - sp = tso->sp; - - // The stack freezing code assumes there's a closure pointer on - // the top of the stack, so we have to arrange that this is the case... - // - if (sp[0] == (W_)&stg_enter_info) { - sp++; - } else { - sp--; - sp[0] = (W_)&stg_dummy_ret_closure; - } - - frame = sp + 1; - while (stop_here == NULL || frame < stop_here) { - - // 1. Let the top of the stack be the "current closure" - // - // 2. Walk up the stack until we find either an UPDATE_FRAME or a - // CATCH_FRAME. - // - // 3. If it's an UPDATE_FRAME, then make an AP_STACK containing the - // current closure applied to the chunk of stack up to (but not - // including) the update frame. This closure becomes the "current - // closure". Go back to step 2. - // - // 4. If it's a CATCH_FRAME, then leave the exception handler on - // top of the stack applied to the exception. - // - // 5. If it's a STOP_FRAME, then kill the thread. - // - // NB: if we pass an ATOMICALLY_FRAME then abort the associated - // transaction - - info = get_ret_itbl((StgClosure *)frame); - - switch (info->i.type) { - - case UPDATE_FRAME: - { - StgAP_STACK * ap; - nat words; - - // First build an AP_STACK consisting of the stack chunk above the - // current update frame, with the top word on the stack as the - // fun field. - // - words = frame - sp - 1; - ap = (StgAP_STACK *)allocateLocal(cap,AP_STACK_sizeW(words)); - - ap->size = words; - ap->fun = (StgClosure *)sp[0]; - sp++; - for(i=0; i < (nat)words; ++i) { - ap->payload[i] = (StgClosure *)*sp++; - } - - SET_HDR(ap,&stg_AP_STACK_info, - ((StgClosure *)frame)->header.prof.ccs /* ToDo */); - TICK_ALLOC_UP_THK(words+1,0); - - //IF_DEBUG(scheduler, - // debugBelch("sched: Updating "); - // printPtr((P_)((StgUpdateFrame *)frame)->updatee); - // debugBelch(" with "); - // printObj((StgClosure *)ap); - // ); - - // 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 - // overwrite an IND_OLDGEN in this case, because we'll screw - // up the mutable lists. To be on the safe side, don't - // overwrite any kind of indirection at all. See also - // threadSqueezeStack in GC.c, where we have to make a similar - // check. - // - if (!closure_IND(((StgUpdateFrame *)frame)->updatee)) { - // revert the black hole - UPD_IND_NOLOCK(((StgUpdateFrame *)frame)->updatee, - (StgClosure *)ap); - } - sp += sizeofW(StgUpdateFrame) - 1; - sp[0] = (W_)ap; // push onto stack - frame = sp + 1; - continue; //no need to bump frame - } - - case STOP_FRAME: - // We've stripped the entire stack, the thread is now dead. - tso->what_next = ThreadKilled; - 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. - debugTrace(DEBUG_stm, - "found atomically block delivering async exception"); - - StgTRecHeader *trec = tso -> trec; - StgTRecHeader *outer = stmGetEnclosingTRec(trec); - stmAbortTransaction(cap, trec); - tso -> trec = outer; - break; - - default: - 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 @@ -4108,10 +2575,15 @@ raiseAsync_(Capability *cap, StgTSO *tso, StgClosure *exception, static void deleteThread (Capability *cap, StgTSO *tso) { - if (tso->why_blocked != BlockedOnCCall && - tso->why_blocked != BlockedOnCCall_NoUnblockExc) { - raiseAsync(cap,tso,NULL); - } + // NOTE: must only be called on a TSO that we have exclusive + // access to, because we will call throwToSingleThreaded() below. + // The TSO must be on the run queue of the Capability we own, or + // we must own all Capabilities. + + if (tso->why_blocked != BlockedOnCCall && + tso->why_blocked != BlockedOnCCall_NoUnblockExc) { + throwToSingleThreaded(cap,tso,NULL); + } } #ifdef FORKPROCESS_PRIMOP_SUPPORTED @@ -4223,8 +2695,9 @@ raiseExceptionHelper (StgRegTable *reg, StgTSO *tso, StgClosure *exception) This should either be a CATCH_RETRY_FRAME (if the retry# is within an orElse#) or should be a ATOMICALLY_FRAME (if the retry# reaches the top level). - We skip CATCH_STM_FRAMEs because retries are not considered to be exceptions, - despite the similar implementation. + We skip CATCH_STM_FRAMEs (aborting and rolling back the nested tx that they + create) because retries are not considered to be exceptions, despite the + similar implementation. We should not expect to see CATCH_FRAME or STOP_FRAME because those should not be created within memory transactions. @@ -4244,7 +2717,7 @@ findRetryFrameHelper (StgTSO *tso) case ATOMICALLY_FRAME: debugTrace(DEBUG_stm, - "found ATOMICALLY_FRAME at %p during retrry", p); + "found ATOMICALLY_FRAME at %p during retry", p); tso->sp = p; return ATOMICALLY_FRAME; @@ -4254,7 +2727,20 @@ findRetryFrameHelper (StgTSO *tso) tso->sp = p; return CATCH_RETRY_FRAME; - case CATCH_STM_FRAME: + case CATCH_STM_FRAME: { + StgTRecHeader *trec = tso -> trec; + StgTRecHeader *outer = stmGetEnclosingTRec(trec); + debugTrace(DEBUG_stm, + "found CATCH_STM_FRAME at %p during retry", p); + debugTrace(DEBUG_stm, "trec=%p outer=%p", trec, outer); + stmAbortTransaction(tso -> cap, trec); + stmFreeAbortedTRec(tso -> cap, trec); + tso -> trec = outer; + p = next; + continue; + } + + default: ASSERT(info->i.type != CATCH_FRAME); ASSERT(info->i.type != STOP_FRAME); @@ -4279,12 +2765,16 @@ resurrectThreads (StgTSO *threads) { StgTSO *tso, *next; Capability *cap; + step *step; for (tso = threads; tso != END_TSO_QUEUE; tso = next) { next = tso->global_link; - tso->global_link = all_threads; - all_threads = tso; - debugTrace(DEBUG_sched, "resurrecting thread %d", tso->id); + + step = Bdescr((P_)tso)->step; + tso->global_link = step->threads; + step->threads = tso; + + debugTrace(DEBUG_sched, "resurrecting thread %lu", (unsigned long)tso->id); // Wake up the thread on the Capability it was last on cap = tso->cap; @@ -4293,13 +2783,16 @@ resurrectThreads (StgTSO *threads) case BlockedOnMVar: case BlockedOnException: /* Called by GC - sched_mutex lock is currently held. */ - raiseAsync(cap, tso,(StgClosure *)BlockedOnDeadMVar_closure); + throwToSingleThreaded(cap, tso, + (StgClosure *)blockedOnDeadMVar_closure); break; case BlockedOnBlackHole: - raiseAsync(cap, tso,(StgClosure *)NonTermination_closure); + throwToSingleThreaded(cap, tso, + (StgClosure *)nonTermination_closure); break; case BlockedOnSTM: - raiseAsync(cap, tso,(StgClosure *)BlockedIndefinitely_closure); + throwToSingleThreaded(cap, tso, + (StgClosure *)blockedIndefinitely_closure); break; case NotBlocked: /* This might happen if the thread was blocked on a black hole @@ -4313,297 +2806,36 @@ resurrectThreads (StgTSO *threads) } } -/* ---------------------------------------------------------------------------- - * Debugging: why is a thread blocked - * [Also provides useful information when debugging threaded programs - * at the Haskell source code level, so enable outside of DEBUG. --sof 7/02] - ------------------------------------------------------------------------- */ - -#if DEBUG -static void -printThreadBlockage(StgTSO *tso) -{ - switch (tso->why_blocked) { - case BlockedOnRead: - debugBelch("is blocked on read from fd %d", (int)(tso->block_info.fd)); - break; - case BlockedOnWrite: - 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: %ld)", tso->block_info.async_result->reqID); - break; -#endif - case BlockedOnDelay: - debugBelch("is blocked until %ld", (long)(tso->block_info.target)); - break; - case BlockedOnMVar: - debugBelch("is blocked on an MVar @ %p", tso->block_info.closure); - break; - case BlockedOnException: - debugBelch("is blocked on delivering an exception to thread %d", - tso->block_info.tso->id); - break; - case BlockedOnBlackHole: - debugBelch("is blocked on a black hole"); - break; - case NotBlocked: - debugBelch("is not blocked"); - break; -#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)); - break; - case BlockedOnGA_NoSend: - debugBelch("is blocked on global address (no send); local FM_BQ is %p (%s)", - tso->block_info.closure, info_type(tso->block_info.closure)); - break; -#endif - case BlockedOnCCall: - debugBelch("is blocked on an external call"); - break; - case BlockedOnCCall_NoUnblockExc: - debugBelch("is blocked on an external call (exceptions were already blocked)"); - break; - case BlockedOnSTM: - debugBelch("is blocked on an STM operation"); - break; - default: - barf("printThreadBlockage: strange tso->why_blocked: %d for TSO %d (%d)", - tso->why_blocked, tso->id, tso); - } -} - -void -printThreadStatus(StgTSO *t) -{ - 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"); - } -} +/* ----------------------------------------------------------------------------- + performPendingThrowTos is called after garbage collection, and + passed a list of threads that were found to have pending throwTos + (tso->blocked_exceptions was not empty), and were blocked. + Normally this doesn't happen, because we would deliver the + exception directly if the target thread is blocked, but there are + small windows where it might occur on a multiprocessor (see + throwTo()). + + NB. we must be holding all the capabilities at this point, just + like resurrectThreads(). + -------------------------------------------------------------------------- */ void -printAllThreads(void) +performPendingThrowTos (StgTSO *threads) { - StgTSO *t, *next; - nat i; - Capability *cap; - -# if defined(GRAN) - char time_string[TIME_STR_LEN], node_str[NODE_STR_LEN]; - ullong_format_string(TIME_ON_PROC(CurrentProc), - time_string, rtsFalse/*no commas!*/); - - debugBelch("all threads at [%s]:\n", time_string); -# 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!*/); - - debugBelch("all threads at [%s]:\n", time_string); -# else - debugBelch("all threads:\n"); -# endif - - 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; - } - } -} - -// 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(PARALLEL_HASKELL) -void -print_bq (StgClosure *node) -{ - StgBlockingQueueElement *bqe; - StgTSO *tso; - rtsBool end; - - debugBelch("## BQ of closure %p (%s): ", - node, info_type(node)); - - /* should cover all closures that may have a blocking queue */ - ASSERT(get_itbl(node)->type == BLACKHOLE_BQ || - get_itbl(node)->type == FETCH_ME_BQ || - get_itbl(node)->type == RBH || - get_itbl(node)->type == MVAR); - - ASSERT(node!=(StgClosure*)NULL); // sanity check - - print_bqe(((StgBlockingQueue*)node)->blocking_queue); -} - -/* - Print a whole blocking queue starting with the element bqe. -*/ -void -print_bqe (StgBlockingQueueElement *bqe) -{ - rtsBool end; - - /* - NB: In a parallel setup a BQ of an RBH must end with an RBH_Save closure; - */ - for (end = (bqe==END_BQ_QUEUE); - !end; // iterate until bqe points to a CONSTR - end = (get_itbl(bqe)->type == CONSTR) || (bqe->link==END_BQ_QUEUE), - bqe = end ? END_BQ_QUEUE : bqe->link) { - ASSERT(bqe != END_BQ_QUEUE); // sanity check - ASSERT(bqe != (StgBlockingQueueElement *)NULL); // sanity check - /* types of closures that may appear in a blocking queue */ - ASSERT(get_itbl(bqe)->type == TSO || - get_itbl(bqe)->type == BLOCKED_FETCH || - get_itbl(bqe)->type == CONSTR); - /* only BQs of an RBH end with an RBH_Save closure */ - //ASSERT(get_itbl(bqe)->type != CONSTR || get_itbl(node)->type == RBH); - - switch (get_itbl(bqe)->type) { - case TSO: - debugBelch(" TSO %u (%x),", - ((StgTSO *)bqe)->id, ((StgTSO *)bqe)); - break; - case BLOCKED_FETCH: - debugBelch(" BF (node=%p, ga=((%x, %d, %x)),", - ((StgBlockedFetch *)bqe)->node, - ((StgBlockedFetch *)bqe)->ga.payload.gc.gtid, - ((StgBlockedFetch *)bqe)->ga.payload.gc.slot, - ((StgBlockedFetch *)bqe)->ga.weight); - break; - case CONSTR: - debugBelch(" %s (IP %p),", - (get_itbl(bqe) == &stg_RBH_Save_0_info ? "RBH_Save_0" : - get_itbl(bqe) == &stg_RBH_Save_1_info ? "RBH_Save_1" : - get_itbl(bqe) == &stg_RBH_Save_2_info ? "RBH_Save_2" : - "RBH_Save_?"), get_itbl(bqe)); - break; - default: - barf("Unexpected closure type %s in blocking queue", // of %p (%s)", - info_type((StgClosure *)bqe)); // , node, info_type(node)); - break; - } - } /* for */ - debugBelch("\n"); -} -# elif defined(GRAN) -void -print_bq (StgClosure *node) -{ - StgBlockingQueueElement *bqe; - PEs node_loc, tso_loc; - rtsBool end; - - /* should cover all closures that may have a blocking queue */ - ASSERT(get_itbl(node)->type == BLACKHOLE_BQ || - get_itbl(node)->type == FETCH_ME_BQ || - get_itbl(node)->type == RBH); - - ASSERT(node!=(StgClosure*)NULL); // sanity check - node_loc = where_is(node); + StgTSO *tso, *next; + Capability *cap; + step *step; - debugBelch("## BQ of closure %p (%s) on [PE %d]: ", - node, info_type(node), node_loc); + for (tso = threads; tso != END_TSO_QUEUE; tso = next) { + next = tso->global_link; - /* - NB: In a parallel setup a BQ of an RBH must end with an RBH_Save closure; - */ - for (bqe = ((StgBlockingQueue*)node)->blocking_queue, end = (bqe==END_BQ_QUEUE); - !end; // iterate until bqe points to a CONSTR - end = (get_itbl(bqe)->type == CONSTR) || (bqe->link==END_BQ_QUEUE), bqe = end ? END_BQ_QUEUE : bqe->link) { - ASSERT(bqe != END_BQ_QUEUE); // sanity check - ASSERT(bqe != (StgBlockingQueueElement *)NULL); // sanity check - /* types of closures that may appear in a blocking queue */ - ASSERT(get_itbl(bqe)->type == TSO || - get_itbl(bqe)->type == CONSTR); - /* only BQs of an RBH end with an RBH_Save closure */ - ASSERT(get_itbl(bqe)->type != CONSTR || get_itbl(node)->type == RBH); - - tso_loc = where_is((StgClosure *)bqe); - switch (get_itbl(bqe)->type) { - case TSO: - debugBelch(" TSO %d (%p) on [PE %d],", - ((StgTSO *)bqe)->id, (StgTSO *)bqe, tso_loc); - break; - case CONSTR: - debugBelch(" %s (IP %p),", - (get_itbl(bqe) == &stg_RBH_Save_0_info ? "RBH_Save_0" : - get_itbl(bqe) == &stg_RBH_Save_1_info ? "RBH_Save_1" : - get_itbl(bqe) == &stg_RBH_Save_2_info ? "RBH_Save_2" : - "RBH_Save_?"), get_itbl(bqe)); - break; - default: - barf("Unexpected closure type %s in blocking queue of %p (%s)", - info_type((StgClosure *)bqe), node, info_type(node)); - break; - } - } /* for */ - debugBelch("\n"); -} -# endif + step = Bdescr((P_)tso)->step; + tso->global_link = step->threads; + step->threads = tso; -#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 */ - } + debugTrace(DEBUG_sched, "performing blocked throwTo to thread %lu", (unsigned long)tso->id); - return i; + cap = tso->cap; + maybePerformBlockedException(cap, tso); + } } -#endif - -#endif /* DEBUG */