*
* WAY Name CPP flag What's it for
* --------------------------------------
- * mp GUM PAR Parallel execution on a distrib. memory machine
+ * mp GUM PARALLEL_HASKELL Parallel execution on a distrib. memory machine
* s SMP SMP Parallel execution on a shared memory machine
* mg GranSim GRAN Simulation of parallel execution
* md GUM/GdH DIST Distributed execution (based on GUM)
#include "RtsUtils.h"
#include "RtsFlags.h"
#include "BlockAlloc.h"
+#include "OSThreads.h"
#include "Storage.h"
#include "StgRun.h"
#include "Hooks.h"
#define COMPILING_SCHEDULER
#include "Schedule.h"
#include "StgMiscClosures.h"
-#include "Storage.h"
#include "Interpreter.h"
#include "Exception.h"
#include "Printer.h"
#include "Signals.h"
#include "Sanity.h"
#include "Stats.h"
+#include "STM.h"
#include "Timer.h"
#include "Prelude.h"
#include "ThreadLabels.h"
#include "Proftimer.h"
#include "ProfHeap.h"
#endif
-#if defined(GRAN) || defined(PAR)
+#if defined(GRAN) || defined(PARALLEL_HASKELL)
# include "GranSimRts.h"
# include "GranSim.h"
# include "ParallelRts.h"
#endif
#include "Sparks.h"
#include "Capability.h"
-#include "OSThreads.h"
#include "Task.h"
#ifdef HAVE_SYS_TYPES_H
#include <errno.h>
#endif
+// Turn off inlining when debugging - it obfuscates things
+#ifdef DEBUG
+# undef STATIC_INLINE
+# define STATIC_INLINE static
+#endif
+
#ifdef THREADED_RTS
#define USED_IN_THREADED_RTS
#else
*/
StgMainThread *main_threads = NULL;
-/* Thread queues.
- * Locks required: sched_mutex.
- */
#if defined(GRAN)
StgTSO* ActiveTSO = NULL; /* for assigning system costs; GranSim-Light only */
#else /* !GRAN */
+/* Thread queues.
+ * Locks required: sched_mutex.
+ */
StgTSO *run_queue_hd = NULL;
StgTSO *run_queue_tl = NULL;
StgTSO *blocked_queue_hd = NULL;
StgTSO *blocked_queue_tl = NULL;
+StgTSO *blackhole_queue = NULL;
StgTSO *sleeping_queue = NULL; /* perhaps replace with a hash table? */
#endif
+/* The blackhole_queue should be checked for threads to wake up. See
+ * Schedule.h for more thorough comment.
+ */
+rtsBool blackholes_need_checking = rtsFalse;
+
/* Linked list of all threads.
* Used for detecting garbage collected threads.
*/
*/
static StgTSO *suspended_ccalling_threads;
-static StgTSO *threadStackOverflow(StgTSO *tso);
-
/* KH: The following two flags are shared memory locations. There is no need
to lock them, since they are only unset at the end of a scheduler
operation.
*/
/* flag set by signal handler to precipitate a context switch */
-nat context_switch = 0;
+int context_switch = 0;
+
+/* flag that tracks whether we have done any execution in this time slice. */
+nat recent_activity = ACTIVITY_YES;
/* if this flag is set as well, give up execution */
rtsBool interrupted = rtsFalse;
*/
StgTSO dummy_tso;
-static rtsBool ready_to_gc;
-
/*
* Set to TRUE when entering a shutdown state (via shutdownHaskellAndExit()) --
* in an MT setting, needed to signal that a worker thread shouldn't hang around
*/
static rtsBool shutting_down_scheduler = rtsFalse;
-void addToBlockedQueue ( StgTSO *tso );
-
-static void schedule ( StgMainThread *mainThread, Capability *initialCapability );
- void interruptStgRts ( void );
-
-static void detectBlackHoles ( void );
-
#if defined(RTS_SUPPORTS_THREADS)
/* ToDo: carefully document the invariants that go together
* with these synchronisation objects.
#endif /* RTS_SUPPORTS_THREADS */
-#if defined(PAR)
+#if defined(PARALLEL_HASKELL)
StgTSO *LastTSO;
rtsTime TimeOfLastYield;
rtsBool emitSchedule = rtsTrue;
};
#endif
-#if defined(PAR)
+/* -----------------------------------------------------------------------------
+ * static function prototypes
+ * -------------------------------------------------------------------------- */
+
+#if defined(RTS_SUPPORTS_THREADS)
+static void taskStart(void);
+#endif
+
+static void schedule( StgMainThread *mainThread USED_WHEN_RTS_SUPPORTS_THREADS,
+ Capability *initialCapability );
+
+//
+// These function all encapsulate parts of the scheduler loop, and are
+// abstracted only to make the structure and control flow of the
+// scheduler clearer.
+//
+static void schedulePreLoop(void);
+static void scheduleStartSignalHandlers(void);
+static void scheduleCheckBlockedThreads(void);
+static void scheduleCheckBlackHoles(void);
+static void scheduleDetectDeadlock(void);
+#if defined(GRAN)
+static StgTSO *scheduleProcessEvent(rtsEvent *event);
+#endif
+#if defined(PARALLEL_HASKELL)
+static StgTSO *scheduleSendPendingMessages(void);
+static void scheduleActivateSpark(void);
+static rtsBool scheduleGetRemoteWork(rtsBool *receivedFinish);
+#endif
+#if defined(PAR) || defined(GRAN)
+static void scheduleGranParReport(void);
+#endif
+static void schedulePostRunThread(void);
+static rtsBool scheduleHandleHeapOverflow( Capability *cap, StgTSO *t );
+static void scheduleHandleStackOverflow( StgTSO *t);
+static rtsBool scheduleHandleYield( StgTSO *t, nat prev_what_next );
+static void scheduleHandleThreadBlocked( StgTSO *t );
+static rtsBool scheduleHandleThreadFinished( StgMainThread *mainThread,
+ Capability *cap, StgTSO *t );
+static rtsBool scheduleDoHeapProfile(rtsBool ready_to_gc);
+static void scheduleDoGC(rtsBool force_major);
+
+static void unblockThread(StgTSO *tso);
+static rtsBool checkBlackHoles(void);
+static SchedulerStatus waitThread_(/*out*/StgMainThread* m,
+ Capability *initialCapability
+ );
+static void scheduleThread_ (StgTSO* tso);
+static void AllRoots(evac_fn evac);
+
+static StgTSO *threadStackOverflow(StgTSO *tso);
+
+static void raiseAsync_(StgTSO *tso, StgClosure *exception,
+ rtsBool stop_at_atomically);
+
+static void printThreadBlockage(StgTSO *tso);
+static void printThreadStatus(StgTSO *tso);
+void printThreadQueue(StgTSO *tso);
+
+#if defined(PARALLEL_HASKELL)
StgTSO * createSparkThread(rtsSpark spark);
StgTSO * activateSpark (rtsSpark spark);
#endif
* ------------------------------------------------------------------------- */
#if defined(RTS_SUPPORTS_THREADS)
-static rtsBool startingWorkerThread = rtsFalse;
+static nat startingWorkerThread = 0;
-static void taskStart(void);
static void
taskStart(void)
{
ACQUIRE_LOCK(&sched_mutex);
- startingWorkerThread = rtsFalse;
+ startingWorkerThread--;
schedule(NULL,NULL);
+ taskStop();
RELEASE_LOCK(&sched_mutex);
}
void
startSchedulerTaskIfNecessary(void)
{
- if(run_queue_hd != END_TSO_QUEUE
- || blocked_queue_hd != END_TSO_QUEUE
- || sleeping_queue != END_TSO_QUEUE)
- {
- if(!startingWorkerThread)
- { // we don't want to start another worker thread
- // just because the last one hasn't yet reached the
- // "waiting for capability" state
- startingWorkerThread = rtsTrue;
- if(!startTask(taskStart))
- {
- startingWorkerThread = rtsFalse;
- }
+ if ( !EMPTY_RUN_QUEUE()
+ && !shutting_down_scheduler // not if we're shutting down
+ && startingWorkerThread==0)
+ {
+ // we don't want to start another worker thread
+ // just because the last one hasn't yet reached the
+ // "waiting for capability" state
+ startingWorkerThread++;
+ if (!maybeStartNewWorker(taskStart)) {
+ startingWorkerThread--;
+ }
}
- }
}
#endif
+/* -----------------------------------------------------------------------------
+ * Putting a thread on the run queue: different scheduling policies
+ * -------------------------------------------------------------------------- */
+
+STATIC_INLINE void
+addToRunQueue( StgTSO *t )
+{
+#if defined(PARALLEL_HASKELL)
+ if (RtsFlags.ParFlags.doFairScheduling) {
+ // this does round-robin scheduling; good for concurrency
+ APPEND_TO_RUN_QUEUE(t);
+ } else {
+ // this does unfair scheduling; good for parallelism
+ PUSH_ON_RUN_QUEUE(t);
+ }
+#else
+ // this does round-robin scheduling; good for concurrency
+ APPEND_TO_RUN_QUEUE(t);
+#endif
+}
+
/* ---------------------------------------------------------------------------
Main scheduling loop.
This is not the ugliest code you could imagine, but it's bloody close.
------------------------------------------------------------------------ */
+
static void
schedule( StgMainThread *mainThread USED_WHEN_RTS_SUPPORTS_THREADS,
Capability *initialCapability )
StgThreadReturnCode ret;
#if defined(GRAN)
rtsEvent *event;
-#elif defined(PAR)
- StgSparkPool *pool;
- rtsSpark spark;
+#elif defined(PARALLEL_HASKELL)
StgTSO *tso;
GlobalTaskId pe;
rtsBool receivedFinish = rtsFalse;
nat tp_size, sp_size; // stats only
# endif
#endif
- rtsBool was_interrupted = rtsFalse;
nat prev_what_next;
+ rtsBool ready_to_gc;
// Pre-condition: sched_mutex is held.
// We might have a capability, passed in as initialCapability.
cap = initialCapability;
-#if defined(RTS_SUPPORTS_THREADS)
- //
- // in the threaded case, the capability is either passed in via the
- // initialCapability parameter, or initialized inside the scheduler
- // loop
- //
- IF_DEBUG(scheduler,
- sched_belch("### NEW SCHEDULER LOOP (main thr: %p, cap: %p)",
- mainThread, initialCapability);
- );
-#else
+#if !defined(RTS_SUPPORTS_THREADS)
// simply initialise it in the non-threaded case
grabCapability(&cap);
#endif
-#if defined(GRAN)
- /* set up first event to get things going */
- /* ToDo: assign costs for system setup and init MainTSO ! */
- new_event(CurrentProc, CurrentProc, CurrentTime[CurrentProc],
- ContinueThread,
- CurrentTSO, (StgClosure*)NULL, (rtsSpark*)NULL);
-
- IF_DEBUG(gran,
- debugBelch("GRAN: Init CurrentTSO (in schedule) = %p\n", CurrentTSO);
- G_TSO(CurrentTSO, 5));
-
- if (RtsFlags.GranFlags.Light) {
- /* Save current time; GranSim Light only */
- CurrentTSO->gran.clock = CurrentTime[CurrentProc];
- }
-
- event = get_next_event();
-
- while (event!=(rtsEvent*)NULL) {
- /* Choose the processor with the next event */
- CurrentProc = event->proc;
- CurrentTSO = event->tso;
+ IF_DEBUG(scheduler,
+ sched_belch("### NEW SCHEDULER LOOP (main thr: %p, cap: %p)",
+ mainThread, initialCapability);
+ );
-#elif defined(PAR)
+ schedulePreLoop();
- while (!receivedFinish) { /* set by processMessages */
- /* when receiving PP_FINISH message */
+ // -----------------------------------------------------------
+ // Scheduler loop starts here:
-#else // everything except GRAN and PAR
+#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 (1) {
+ while (TERMINATION_CONDITION) {
+#if defined(GRAN)
+ /* Choose the processor with the next event */
+ CurrentProc = event->proc;
+ CurrentTSO = event->tso;
#endif
- IF_DEBUG(scheduler, printAllThreads());
-
#if defined(RTS_SUPPORTS_THREADS)
// Yield the capability to higher-priority tasks if necessary.
//
if (cap != NULL) {
- yieldCapability(&cap);
+ yieldCapability(&cap,
+ mainThread ? &mainThread->bound_thread_cond : NULL );
}
// If we do not currently hold a capability, we wait for one
// We now have a capability...
#endif
- //
- // If we're interrupted (the user pressed ^C, or some other
- // termination condition occurred), kill all the currently running
- // threads.
- //
- if (interrupted) {
- IF_DEBUG(scheduler, sched_belch("interrupted"));
- interrupted = rtsFalse;
- was_interrupted = rtsTrue;
-#if defined(RTS_SUPPORTS_THREADS)
- // In the threaded RTS, deadlock detection doesn't work,
- // so just exit right away.
- errorBelch("interrupted");
- releaseCapability(cap);
- RELEASE_LOCK(&sched_mutex);
- shutdownHaskellAndExit(EXIT_SUCCESS);
-#else
- deleteAllThreads();
+#if 0 /* extra sanity checking */
+ {
+ StgMainThread *m;
+ for (m = main_threads; m != NULL; m = m->link) {
+ ASSERT(get_itbl(m->tso)->type == TSO);
+ }
+ }
#endif
- }
-#if defined(RTS_USER_SIGNALS)
- // check for signals each time around the scheduler
- if (signals_pending()) {
- RELEASE_LOCK(&sched_mutex); /* ToDo: kill */
- startSignalHandlers();
- ACQUIRE_LOCK(&sched_mutex);
+ // Check whether we have re-entered the RTS from Haskell without
+ // going via suspendThread()/resumeThread (i.e. a 'safe' foreign
+ // call).
+ if (cap->r.rInHaskell) {
+ errorBelch("schedule: re-entered unsafely.\n"
+ " Perhaps a 'foreign import unsafe' should be 'safe'?");
+ stg_exit(1);
}
-#endif
//
- // Check whether any waiting threads need to be woken up. If the
- // run queue is empty, and there are no other tasks running, we
- // can wait indefinitely for something to happen.
+ // Test for interruption. If interrupted==rtsTrue, then either
+ // we received a keyboard interrupt (^C), or the scheduler is
+ // trying to shut down all the tasks (shutting_down_scheduler) in
+ // the threaded RTS.
//
- if ( !EMPTY_QUEUE(blocked_queue_hd) || !EMPTY_QUEUE(sleeping_queue)
-#if defined(RTS_SUPPORTS_THREADS)
- || EMPTY_RUN_QUEUE()
-#endif
- )
- {
- awaitEvent( EMPTY_RUN_QUEUE() );
+ if (interrupted) {
+ if (shutting_down_scheduler) {
+ IF_DEBUG(scheduler, sched_belch("shutting down"));
+ releaseCapability(cap);
+ if (mainThread) {
+ mainThread->stat = Interrupted;
+ mainThread->ret = NULL;
+ }
+ return;
+ } else {
+ IF_DEBUG(scheduler, sched_belch("interrupted"));
+ deleteAllThreads();
+ }
}
- // we can be interrupted while waiting for I/O...
- if (interrupted) continue;
- /*
- * Detect deadlock: when we have no threads to run, there are no
- * threads waiting on I/O or sleeping, and all the other tasks are
- * waiting for work, we must have a deadlock of some description.
- *
- * We first try to find threads blocked on themselves (ie. black
- * holes), and generate NonTermination exceptions where necessary.
- *
- * If no threads are black holed, we have a deadlock situation, so
- * inform all the main threads.
- */
-#if !defined(PAR) && !defined(RTS_SUPPORTS_THREADS)
- if ( EMPTY_THREAD_QUEUES() )
+#if defined(not_yet) && defined(SMP)
+ //
+ // Top up the run queue from our spark pool. We try to make the
+ // number of threads in the run queue equal to the number of
+ // free capabilities.
+ //
{
- IF_DEBUG(scheduler, sched_belch("deadlocked, forcing major GC..."));
- // Garbage collection can release some new threads due to
- // either (a) finalizers or (b) threads resurrected because
- // they are about to be send BlockedOnDeadMVar. Any threads
- // thus released will be immediately runnable.
- GarbageCollect(GetRoots,rtsTrue);
+ StgClosure *spark;
+ if (EMPTY_RUN_QUEUE()) {
+ spark = findSpark(rtsFalse);
+ if (spark == NULL) {
+ break; /* no more sparks in the pool */
+ } else {
+ createSparkThread(spark);
+ IF_DEBUG(scheduler,
+ sched_belch("==^^ turning spark of closure %p into a thread",
+ (StgClosure *)spark));
+ }
+ }
+ }
+#endif // SMP
- if ( !EMPTY_RUN_QUEUE() ) { goto not_deadlocked; }
+ scheduleStartSignalHandlers();
- IF_DEBUG(scheduler,
- sched_belch("still deadlocked, checking for black holes..."));
- detectBlackHoles();
+ // Only check the black holes here if we've nothing else to do.
+ // During normal execution, the black hole list only gets checked
+ // at GC time, to avoid repeatedly traversing this possibly long
+ // list each time around the scheduler.
+ if (EMPTY_RUN_QUEUE()) { scheduleCheckBlackHoles(); }
- if ( !EMPTY_RUN_QUEUE() ) { goto not_deadlocked; }
+ scheduleCheckBlockedThreads();
-#if defined(RTS_USER_SIGNALS)
- /* If we have user-installed signal handlers, then wait
- * for signals to arrive rather then bombing out with a
- * deadlock.
- */
- if ( anyUserHandlers() ) {
- IF_DEBUG(scheduler,
- sched_belch("still deadlocked, waiting for signals..."));
+ scheduleDetectDeadlock();
- awaitUserSignals();
+ // Normally, the only way we can get here with no threads to
+ // run is if a keyboard interrupt received during
+ // scheduleCheckBlockedThreads() or scheduleDetectDeadlock().
+ // Additionally, it is not fatal for the
+ // threaded RTS to reach here with no threads to run.
+ //
+ // win32: might be here due to awaitEvent() being abandoned
+ // as a result of a console event having been delivered.
+ if ( EMPTY_RUN_QUEUE() ) {
+#if !defined(RTS_SUPPORTS_THREADS) && !defined(mingw32_HOST_OS)
+ ASSERT(interrupted);
+#endif
+ continue; // nothing to do
+ }
- // we might be interrupted...
- if (interrupted) { continue; }
+#if defined(PARALLEL_HASKELL)
+ scheduleSendPendingMessages();
+ if (EMPTY_RUN_QUEUE() && scheduleActivateSpark())
+ continue;
- if (signals_pending()) {
- RELEASE_LOCK(&sched_mutex);
- startSignalHandlers();
- ACQUIRE_LOCK(&sched_mutex);
- }
- ASSERT(!EMPTY_RUN_QUEUE());
- goto not_deadlocked;
- }
+#if defined(SPARKS)
+ ASSERT(next_fish_to_send_at==0); // i.e. no delayed fishes left!
#endif
- /* Probably a real deadlock. Send the current main thread the
- * Deadlock exception (or in the SMP build, send *all* main
- * threads the deadlock exception, since none of them can make
- * progress).
- */
- {
- StgMainThread *m;
- m = main_threads;
- switch (m->tso->why_blocked) {
- case BlockedOnBlackHole:
- case BlockedOnException:
- case BlockedOnMVar:
- raiseAsync(m->tso, (StgClosure *)NonTermination_closure);
- break;
- default:
- barf("deadlock: main thread blocked in a strange way");
- }
- }
+ /* If we still have no work we need to send a FISH to get a spark
+ from another PE */
+ if (EMPTY_RUN_QUEUE()) {
+ 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();
}
- not_deadlocked:
+#endif
-#elif defined(RTS_SUPPORTS_THREADS)
- // ToDo: add deadlock detection in threaded RTS
-#elif defined(PAR)
- // ToDo: add deadlock detection in GUM (similar to SMP) -- HWL
+#if defined(GRAN)
+ scheduleProcessEvent(event);
+#endif
+
+ //
+ // Get a thread to run
+ //
+ ASSERT(run_queue_hd != END_TSO_QUEUE);
+ POP_RUN_QUEUE(t);
+
+#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(RTS_SUPPORTS_THREADS)
- if ( EMPTY_RUN_QUEUE() ) {
- continue; // nothing to do
+ // Check whether we can run this thread in the current task.
+ // If not, we have to pass our capability to the right task.
+ {
+ StgMainThread *m = t->main;
+
+ if(m)
+ {
+ if(m == mainThread)
+ {
+ IF_DEBUG(scheduler,
+ sched_belch("### Running thread %d in bound thread", t->id));
+ // yes, the Haskell thread is bound to the current native thread
+ }
+ else
+ {
+ IF_DEBUG(scheduler,
+ sched_belch("### thread %d bound to another OS thread", t->id));
+ // no, bound to a different Haskell thread: pass to that thread
+ PUSH_ON_RUN_QUEUE(t);
+ continue;
+ }
+ }
+ else
+ {
+ if(mainThread != NULL)
+ // The thread we want to run is unbound.
+ {
+ IF_DEBUG(scheduler,
+ sched_belch("### this OS thread cannot run thread %d", t->id));
+ // no, the current native thread is bound to a different
+ // Haskell thread, so pass it to any worker thread
+ PUSH_ON_RUN_QUEUE(t);
+ continue;
+ }
+ }
}
#endif
-#if defined(GRAN)
- 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;
+ cap->r.rCurrentTSO = t;
- /* Deal with the idle PEs (may issue FindWork or MoveSpark events) */
- if (!RtsFlags.GranFlags.Light)
- handleIdlePEs();
+ /* context switches are now initiated by the timer signal, unless
+ * the user specified "context switch as often as possible", with
+ * +RTS -C0
+ */
+ if ((RtsFlags.ConcFlags.ctxtSwitchTicks == 0
+ && (run_queue_hd != END_TSO_QUEUE
+ || blocked_queue_hd != END_TSO_QUEUE
+ || sleeping_queue != END_TSO_QUEUE)))
+ context_switch = 1;
- IF_DEBUG(gran, debugBelch("GRAN: switch by event-type\n"));
+run_thread:
- /* 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;
- }
+ RELEASE_LOCK(&sched_mutex);
+
+ IF_DEBUG(scheduler, sched_belch("-->> running thread %ld %s ...",
+ (long)t->id, whatNext_strs[t->what_next]));
+
+#if defined(PROFILING)
+ startHeapProfTimer();
+#endif
+
+ // ----------------------------------------------------------------------
+ // Run the current thread
+
+ prev_what_next = t->what_next;
+
+ errno = t->saved_errno;
+ cap->r.rInHaskell = rtsTrue;
+
+ recent_activity = ACTIVITY_YES;
+
+ switch (prev_what_next) {
+
+ case ThreadKilled:
+ case ThreadComplete:
+ /* Thread already finished, return to scheduler. */
+ ret = ThreadFinished;
+ break;
+
+ case ThreadRunGHC:
+ ret = StgRun((StgFunPtr) stg_returnToStackTop, &cap->r);
+ break;
+
+ case ThreadInterpret:
+ ret = interpretBCO(cap);
+ break;
+
+ default:
+ barf("schedule: invalid what_next field");
+ }
+
+#if defined(SMP)
+ // in SMP mode, we might return with a different capability than
+ // we started with, if the Haskell thread made a foreign call. So
+ // let's find out what our current Capability is:
+ cap = myCapability();
+#endif
+
+ cap->r.rInHaskell = rtsFalse;
+
+ // The TSO might have moved, eg. if it re-entered the RTS and a GC
+ // happened. So find the new location:
+ t = cap->r.rCurrentTSO;
+
+ // And save the current errno in this thread.
+ t->saved_errno = errno;
+
+ // ----------------------------------------------------------------------
+
+ /* Costs for the scheduler are assigned to CCS_SYSTEM */
+#if defined(PROFILING)
+ stopHeapProfTimer();
+ CCCS = CCS_SYSTEM;
+#endif
+
+ ACQUIRE_LOCK(&sched_mutex);
+
+ // We have run some Haskell code: there might be blackhole-blocked
+ // threads to wake up now.
+ if ( blackhole_queue != END_TSO_QUEUE ) {
+ blackholes_need_checking = rtsTrue;
+ }
+
+#if defined(RTS_SUPPORTS_THREADS)
+ IF_DEBUG(scheduler,debugBelch("sched (task %p): ", osThreadId()););
+#elif !defined(GRAN) && !defined(PARALLEL_HASKELL)
+ IF_DEBUG(scheduler,debugBelch("sched: "););
+#endif
+
+ schedulePostRunThread();
+
+ ready_to_gc = rtsFalse;
+
+ switch (ret) {
+ case HeapOverflow:
+ ready_to_gc = scheduleHandleHeapOverflow(cap,t);
+ break;
+
+ case StackOverflow:
+ scheduleHandleStackOverflow(t);
+ break;
+
+ case ThreadYielding:
+ if (scheduleHandleYield(t, prev_what_next)) {
+ // shortcut for switching between compiler/interpreter:
+ goto run_thread;
+ }
+ break;
+
+ case ThreadBlocked:
+ scheduleHandleThreadBlocked(t);
+ break;
+
+ case ThreadFinished:
+ if (scheduleHandleThreadFinished(mainThread, cap, t)) return;;
+ break;
+
+ default:
+ barf("schedule: invalid thread return code %d", (int)ret);
+ }
+
+ if (scheduleDoHeapProfile(ready_to_gc)) { ready_to_gc = rtsFalse; }
+ if (ready_to_gc) { scheduleDoGC(rtsFalse); }
+ } /* end of while() */
+
+ IF_PAR_DEBUG(verbose,
+ debugBelch("== Leaving schedule() after having received Finish\n"));
+}
+
+/* ----------------------------------------------------------------------------
+ * Setting up the scheduler loop
+ * ASSUMES: sched_mutex
+ * ------------------------------------------------------------------------- */
+
+static void
+schedulePreLoop(void)
+{
+#if defined(GRAN)
+ /* set up first event to get things going */
+ /* ToDo: assign costs for system setup and init MainTSO ! */
+ new_event(CurrentProc, CurrentProc, CurrentTime[CurrentProc],
+ ContinueThread,
+ CurrentTSO, (StgClosure*)NULL, (rtsSpark*)NULL);
+
+ IF_DEBUG(gran,
+ debugBelch("GRAN: Init CurrentTSO (in schedule) = %p\n",
+ CurrentTSO);
+ G_TSO(CurrentTSO, 5));
+
+ if (RtsFlags.GranFlags.Light) {
+ /* Save current time; GranSim Light only */
+ CurrentTSO->gran.clock = CurrentTime[CurrentProc];
+ }
+#endif
+}
+
+/* ----------------------------------------------------------------------------
+ * Start any pending signal handlers
+ * ASSUMES: sched_mutex
+ * ------------------------------------------------------------------------- */
+
+static void
+scheduleStartSignalHandlers(void)
+{
+#if defined(RTS_USER_SIGNALS) && !defined(RTS_SUPPORTS_THREADS)
+ if (signals_pending()) {
+ RELEASE_LOCK(&sched_mutex); /* ToDo: kill */
+ startSignalHandlers();
+ ACQUIRE_LOCK(&sched_mutex);
+ }
+#endif
+}
+
+/* ----------------------------------------------------------------------------
+ * Check for blocked threads that can be woken up.
+ * ASSUMES: sched_mutex
+ * ------------------------------------------------------------------------- */
+
+static void
+scheduleCheckBlockedThreads(void)
+{
+ //
+ // Check whether any waiting threads need to be woken up. If the
+ // run queue is empty, and there are no other tasks running, we
+ // can wait indefinitely for something to happen.
+ //
+ if ( !EMPTY_QUEUE(blocked_queue_hd) || !EMPTY_QUEUE(sleeping_queue) )
+ {
+#if defined(RTS_SUPPORTS_THREADS)
+ // We shouldn't be here...
+ barf("schedule: awaitEvent() in threaded RTS");
+#else
+ awaitEvent( EMPTY_RUN_QUEUE() && !blackholes_need_checking );
+#endif
+ }
+}
+
+
+/* ----------------------------------------------------------------------------
+ * Check for threads blocked on BLACKHOLEs that can be woken up
+ * ASSUMES: sched_mutex
+ * ------------------------------------------------------------------------- */
+static void
+scheduleCheckBlackHoles( void )
+{
+ if ( blackholes_need_checking )
+ {
+ checkBlackHoles();
+ blackholes_need_checking = rtsFalse;
+ }
+}
+
+/* ----------------------------------------------------------------------------
+ * Detect deadlock conditions and attempt to resolve them.
+ * ASSUMES: sched_mutex
+ * ------------------------------------------------------------------------- */
+
+static void
+scheduleDetectDeadlock()
+{
+
+#if defined(PARALLEL_HASKELL)
+ // ToDo: add deadlock detection in GUM (similar to SMP) -- HWL
+ return;
+#endif
+
+ /*
+ * Detect deadlock: when we have no threads to run, there are no
+ * threads blocked, waiting for I/O, or sleeping, and all the
+ * other tasks are waiting for work, we must have a deadlock of
+ * some description.
+ */
+ if ( EMPTY_THREAD_QUEUES() )
+ {
+#if defined(RTS_SUPPORTS_THREADS)
+ /*
+ * In the threaded RTS, we only check for deadlock if there
+ * has been no activity in a complete timeslice. This means
+ * we won't eagerly start a full GC just because we don't have
+ * any threads to run currently.
+ */
+ if (recent_activity != ACTIVITY_INACTIVE) return;
+#endif
+
+ IF_DEBUG(scheduler, sched_belch("deadlocked, forcing major GC..."));
+
+ // Garbage collection can release some new threads due to
+ // either (a) finalizers or (b) threads resurrected because
+ // they are unreachable and will therefore be sent an
+ // exception. Any threads thus released will be immediately
+ // runnable.
+
+ scheduleDoGC( rtsTrue/*force major GC*/ );
+ recent_activity = ACTIVITY_DONE_GC;
+ if ( !EMPTY_RUN_QUEUE() ) return;
+
+#if defined(RTS_USER_SIGNALS) && !defined(RTS_SUPPORTS_THREADS)
+ /* If we have user-installed signal handlers, then wait
+ * for signals to arrive rather then bombing out with a
+ * deadlock.
+ */
+ if ( anyUserHandlers() ) {
+ IF_DEBUG(scheduler,
+ sched_belch("still deadlocked, waiting for signals..."));
+
+ awaitUserSignals();
+
+ if (signals_pending()) {
+ RELEASE_LOCK(&sched_mutex);
+ startSignalHandlers();
+ ACQUIRE_LOCK(&sched_mutex);
+ }
+
+ // either we have threads to run, or we were interrupted:
+ ASSERT(!EMPTY_RUN_QUEUE() || interrupted);
+ }
+#endif
+
+#if !defined(RTS_SUPPORTS_THREADS)
+ /* Probably a real deadlock. Send the current main thread the
+ * Deadlock exception (or in the SMP build, send *all* main
+ * threads the deadlock exception, since none of them can make
+ * progress).
+ */
+ {
+ StgMainThread *m;
+ m = main_threads;
+ switch (m->tso->why_blocked) {
+ case BlockedOnSTM:
+ case BlockedOnBlackHole:
+ case BlockedOnException:
+ case BlockedOnMVar:
+ raiseAsync(m->tso, (StgClosure *)NonTermination_closure);
+ return;
+ default:
+ barf("deadlock: main thread blocked in a strange way");
+ }
+ }
+#endif
+ }
+}
+
+/* ----------------------------------------------------------------------------
+ * Process an event (GRAN only)
+ * ------------------------------------------------------------------------- */
+
+#if defined(GRAN)
+static StgTSO *
+scheduleProcessEvent(rtsEvent *event)
+{
+ StgTSO *t;
+
+ if (RtsFlags.GranFlags.Light)
+ GranSimLight_enter_system(event, &ActiveTSO); // adjust ActiveTSO etc
+
+ /* adjust time based on time-stamp */
+ if (event->time > CurrentTime[CurrentProc] &&
+ event->evttype != ContinueThread)
+ CurrentTime[CurrentProc] = event->time;
+
+ /* Deal with the idle PEs (may issue FindWork or MoveSpark events) */
+ if (!RtsFlags.GranFlags.Light)
+ handleIdlePEs();
+
+ IF_DEBUG(gran, debugBelch("GRAN: switch by event-type\n"));
+
+ /* main event dispatcher in GranSim */
+ switch (event->evttype) {
+ /* Should just be continuing execution */
+ case ContinueThread:
+ IF_DEBUG(gran, debugBelch("GRAN: doing ContinueThread\n"));
+ /* ToDo: check assertion
+ ASSERT(run_queue_hd != (StgTSO*)NULL &&
+ run_queue_hd != END_TSO_QUEUE);
+ */
+ /* Ignore ContinueThreads for fetching threads (if synchr comm) */
+ if (!RtsFlags.GranFlags.DoAsyncFetch &&
+ procStatus[CurrentProc]==Fetching) {
+ debugBelch("ghuH: Spurious ContinueThread while Fetching ignored; TSO %d (%p) [PE %d]\n",
+ CurrentTSO->id, CurrentTSO, CurrentProc);
+ goto next_thread;
+ }
/* 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",
DumpGranEvent(GR_SCHEDULE, t));
procStatus[CurrentProc] = Busy;
+}
+#endif // GRAN
-#elif defined(PAR)
+/* ----------------------------------------------------------------------------
+ * Send pending messages (PARALLEL_HASKELL only)
+ * ------------------------------------------------------------------------- */
+
+#if defined(PARALLEL_HASKELL)
+static StgTSO *
+scheduleSendPendingMessages(void)
+{
+ StgSparkPool *pool;
+ rtsSpark spark;
+ StgTSO *t;
+
+# if defined(PAR) // global Mem.Mgmt., omit for now
if (PendingFetches != END_BF_QUEUE) {
processFetches();
}
+# endif
+
+ if (RtsFlags.ParFlags.BufferTime) {
+ // if we use message buffering, we must send away all message
+ // packets which have become too old...
+ sendOldBuffers();
+ }
+}
+#endif
- /* ToDo: phps merge with spark activation above */
- /* check whether we have local work and send requests if we have none */
- if (EMPTY_RUN_QUEUE()) { /* no runnable threads */
- /* :-[ no local threads => look out for local sparks */
- /* the spark pool for the current PE */
- pool = &(MainRegTable.rSparks); // generalise to cap = &MainRegTable
- if (advisory_thread_count < RtsFlags.ParFlags.maxThreads &&
- pool->hd < pool->tl) {
- /*
- * ToDo: add GC code check that we really have enough heap afterwards!!
+/* ----------------------------------------------------------------------------
+ * Activate spark threads (PARALLEL_HASKELL only)
+ * ------------------------------------------------------------------------- */
+
+#if defined(PARALLEL_HASKELL)
+static void
+scheduleActivateSpark(void)
+{
+#if defined(SPARKS)
+ ASSERT(EMPTY_RUN_QUEUE());
+/* 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
* thread...
*/
- spark = findSpark(rtsFalse); /* get a spark */
- if (spark != (rtsSpark) NULL) {
- tso = activateSpark(spark); /* turn the spark into a thread */
- IF_PAR_DEBUG(schedule,
- debugBelch("==== schedule: Created TSO %d (%p); %d threads active\n",
- tso->id, tso, advisory_thread_count));
-
- if (tso==END_TSO_QUEUE) { /* failed to activate spark->back to loop */
- debugBelch("==^^ failed to activate spark\n");
- goto next_thread;
- } /* otherwise fall through & pick-up new tso */
- } else {
- IF_PAR_DEBUG(verbose,
- debugBelch("==^^ no local sparks (spark pool contains only NFs: %d)\n",
- spark_queue_len(pool)));
- goto next_thread;
+ spark = findSpark(rtsFalse); /* get a spark */
+ if (spark != (rtsSpark) NULL) {
+ tso = createThreadFromSpark(spark); /* turn the spark into a thread */
+ IF_PAR_DEBUG(fish, // schedule,
+ debugBelch("==== schedule: Created TSO %d (%p); %d threads active\n",
+ tso->id, tso, advisory_thread_count));
+
+ if (tso==END_TSO_QUEUE) { /* failed to activate spark->back to loop */
+ IF_PAR_DEBUG(fish, // schedule,
+ debugBelch("==^^ failed to create thread from spark @ %lx\n",
+ spark));
+ return rtsFalse; /* failed to generate a thread */
+ } /* otherwise fall through & pick-up new tso */
+ } else {
+ IF_PAR_DEBUG(fish, // schedule,
+ debugBelch("==^^ no local sparks (spark pool contains only NFs: %d)\n",
+ spark_queue_len(pool)));
+ return rtsFalse; /* failed to generate a thread */
+ }
+ return rtsTrue; /* success in generating a thread */
+ } else { /* no more threads permitted or pool empty */
+ return rtsFalse; /* failed to generateThread */
+ }
+#else
+ tso = NULL; // avoid compiler warning only
+ return rtsFalse; /* dummy in non-PAR setup */
+#endif // SPARKS
+}
+#endif // PARALLEL_HASKELL
+
+/* ----------------------------------------------------------------------------
+ * Get work from a remote node (PARALLEL_HASKELL only)
+ * ------------------------------------------------------------------------- */
+
+#if defined(PARALLEL_HASKELL)
+static rtsBool
+scheduleGetRemoteWork(rtsBool *receivedFinish)
+{
+ ASSERT(EMPTY_RUN_QUEUE());
+
+ if (RtsFlags.ParFlags.BufferTime) {
+ IF_PAR_DEBUG(verbose,
+ debugBelch("...send all pending data,"));
+ {
+ nat i;
+ for (i=1; i<=nPEs; i++)
+ sendImmediately(i); // send all messages away immediately
}
- }
+ }
+# ifndef SPARKS
+ //++EDEN++ idle() , i.e. send all buffers, wait for work
+ // suppress fishing in EDEN... just look for incoming messages
+ // (blocking receive)
+ IF_PAR_DEBUG(verbose,
+ debugBelch("...wait for incoming messages...\n"));
+ *receivedFinish = processMessages(); // blocking receive...
+
+ // and reenter scheduling loop after having received something
+ // (return rtsFalse below)
+
+# else /* activate SPARKS machinery */
+/* We get here, if we have no work, tried to activate a local spark, but still
+ have no work. We try to get a remote spark, by sending a FISH message.
+ Thread migration should be added here, and triggered when a sequence of
+ fishes returns without work. */
+ delay = (RtsFlags.ParFlags.fishDelay!=0ll ? RtsFlags.ParFlags.fishDelay : 0ll);
- /* If we still have no work we need to send a FISH to get a spark
- from another PE
- */
- if (EMPTY_RUN_QUEUE()) {
/* =8-[ no local sparks => look for work on other PEs */
/*
* We really have absolutely no work. Send out a fish
* we're hoping to see. (Of course, we still have to
* respond to other types of messages.)
*/
- TIME now = msTime() /*CURRENT_TIME*/;
+ rtsTime now = msTime() /*CURRENT_TIME*/;
IF_PAR_DEBUG(verbose,
debugBelch("-- now=%ld\n", now));
- IF_PAR_DEBUG(verbose,
- if (outstandingFishes < RtsFlags.ParFlags.maxFishes &&
- (last_fish_arrived_at!=0 &&
- last_fish_arrived_at+RtsFlags.ParFlags.fishDelay > now)) {
- debugBelch("--$$ delaying FISH until %ld (last fish %ld, delay %ld, now %ld)\n",
- last_fish_arrived_at+RtsFlags.ParFlags.fishDelay,
- last_fish_arrived_at,
- RtsFlags.ParFlags.fishDelay, now);
- });
-
+ IF_PAR_DEBUG(fish, // verbose,
+ if (outstandingFishes < RtsFlags.ParFlags.maxFishes &&
+ (last_fish_arrived_at!=0 &&
+ last_fish_arrived_at+delay > now)) {
+ debugBelch("--$$ <%llu> delaying FISH until %llu (last fish %llu, delay %llu)\n",
+ now, last_fish_arrived_at+delay,
+ last_fish_arrived_at,
+ delay);
+ });
+
if (outstandingFishes < RtsFlags.ParFlags.maxFishes &&
- (last_fish_arrived_at==0 ||
- (last_fish_arrived_at+RtsFlags.ParFlags.fishDelay <= now))) {
- /* outstandingFishes is set in sendFish, processFish;
- avoid flooding system with fishes via delay */
- pe = choosePE();
- sendFish(pe, mytid, NEW_FISH_AGE, NEW_FISH_HISTORY,
- NEW_FISH_HUNGER);
-
- // Global statistics: count no. of fishes
- if (RtsFlags.ParFlags.ParStats.Global &&
- RtsFlags.GcFlags.giveStats > NO_GC_STATS) {
- globalParStats.tot_fish_mess++;
- }
- }
-
- receivedFinish = processMessages();
- goto next_thread;
+ advisory_thread_count < RtsFlags.ParFlags.maxThreads) { // send a FISH, but when?
+ if (last_fish_arrived_at==0 ||
+ (last_fish_arrived_at+delay <= now)) { // send FISH now!
+ /* outstandingFishes is set in sendFish, processFish;
+ avoid flooding system with fishes via delay */
+ next_fish_to_send_at = 0;
+ } else {
+ /* ToDo: this should be done in the main scheduling loop to avoid the
+ busy wait here; not so bad if fish delay is very small */
+ int iq = 0; // DEBUGGING -- HWL
+ next_fish_to_send_at = last_fish_arrived_at+delay; // remember when to send
+ /* send a fish when ready, but process messages that arrive in the meantime */
+ do {
+ if (PacketsWaiting()) {
+ iq++; // DEBUGGING
+ *receivedFinish = processMessages();
}
- } else if (PacketsWaiting()) { /* Look for incoming messages */
- receivedFinish = processMessages();
- }
+ now = msTime();
+ } while (!*receivedFinish || now<next_fish_to_send_at);
+ // JB: This means the fish could become obsolete, if we receive
+ // work. Better check for work again?
+ // last line: while (!receivedFinish || !haveWork || now<...)
+ // next line: if (receivedFinish || haveWork )
+
+ if (*receivedFinish) // no need to send a FISH if we are finishing anyway
+ return rtsFalse; // NB: this will leave scheduler loop
+ // immediately after return!
+
+ IF_PAR_DEBUG(fish, // verbose,
+ debugBelch("--$$ <%llu> sent delayed fish (%d processMessages); active/total threads=%d/%d\n",now,iq,run_queue_len(),advisory_thread_count));
- /* Now we are sure that we have some work available */
- ASSERT(run_queue_hd != END_TSO_QUEUE);
+ }
- /* Take a thread from the run queue, if we have work */
- POP_RUN_QUEUE(t); // take_off_run_queue(END_TSO_QUEUE);
- IF_DEBUG(sanity,checkTSO(t));
+ // JB: IMHO, this should all be hidden inside sendFish(...)
+ /* pe = choosePE();
+ sendFish(pe, thisPE, NEW_FISH_AGE, NEW_FISH_HISTORY,
+ NEW_FISH_HUNGER);
+
+ // Global statistics: count no. of fishes
+ if (RtsFlags.ParFlags.ParStats.Global &&
+ RtsFlags.GcFlags.giveStats > NO_GC_STATS) {
+ globalParStats.tot_fish_mess++;
+ }
+ */
+
+ /* delayed fishes must have been sent by now! */
+ next_fish_to_send_at = 0;
+ }
+
+ *receivedFinish = processMessages();
+# endif /* SPARKS */
+
+ return rtsFalse;
+ /* NB: this function always returns rtsFalse, meaning the scheduler
+ loop continues with the next iteration;
+ rationale:
+ return code means success in finding work; we enter this function
+ if there is no local work, thus have to send a fish which takes
+ time until it arrives with work; in the meantime we should process
+ messages in the main loop;
+ */
+}
+#endif // PARALLEL_HASKELL
+
+/* ----------------------------------------------------------------------------
+ * PAR/GRAN: Report stats & debugging info(?)
+ * ------------------------------------------------------------------------- */
+
+#if defined(PAR) || defined(GRAN)
+static void
+scheduleGranParReport(void)
+{
+ ASSERT(run_queue_hd != END_TSO_QUEUE);
+
+ /* Take a thread from the run queue, if we have work */
+ POP_RUN_QUEUE(t); // take_off_run_queue(END_TSO_QUEUE);
+
+ /* If this TSO has got its outport closed in the meantime,
+ * it mustn't be run. Instead, we have to clean it up as if it was finished.
+ * It has to be marked as TH_DEAD for this purpose.
+ * If it is TH_TERM instead, it is supposed to have finished in the normal way.
+
+JB: TODO: investigate wether state change field could be nuked
+ entirely and replaced by the normal tso state (whatnext
+ field). All we want to do is to kill tsos from outside.
+ */
/* ToDo: write something to the log-file
if (RTSflags.ParFlags.granSimStats && !sameThread)
CurrentTSO = t;
*/
/* the spark pool for the current PE */
- pool = &(MainRegTable.rSparks); // generalise to cap = &MainRegTable
+ pool = &(cap.r.rSparks); // cap = (old) MainCap
IF_DEBUG(scheduler,
debugBelch("--=^ %d threads, %d sparks on [%#x]\n",
run_queue_len(), spark_queue_len(pool), CURRENT_PROC));
-# if 1
- if (0 && RtsFlags.ParFlags.ParStats.Full &&
- t && LastTSO && t->id != LastTSO->id &&
- LastTSO->why_blocked == NotBlocked &&
- LastTSO->what_next != ThreadComplete) {
- // if previously scheduled TSO not blocked we have to record the context switch
- DumpVeryRawGranEvent(TimeOfLastYield, CURRENT_PROC, CURRENT_PROC,
- GR_DESCHEDULE, LastTSO, (StgClosure *)NULL, 0, 0);
- }
+ IF_PAR_DEBUG(fish,
+ debugBelch("--=^ %d threads, %d sparks on [%#x]\n",
+ run_queue_len(), spark_queue_len(pool), CURRENT_PROC));
if (RtsFlags.ParFlags.ParStats.Full &&
- (emitSchedule /* forced emit */ ||
- (t && LastTSO && t->id != LastTSO->id))) {
+ (t->par.sparkname != (StgInt)0) && // only log spark generated threads
+ (emitSchedule || // forced emit
+ (t && LastTSO && t->id != LastTSO->id))) {
/*
we are running a different TSO, so write a schedule event to log file
NB: If we use fair scheduling we also have to write a deschedule
previous tso has blocked whenever we switch to another tso, so
we don't need it in GUM for now
*/
+ IF_PAR_DEBUG(fish, // schedule,
+ debugBelch("____ scheduling spark generated thread %d (%lx) (%lx) via a forced emit\n",t->id,t,t->par.sparkname));
+
DumpRawGranEvent(CURRENT_PROC, CURRENT_PROC,
GR_SCHEDULE, t, (StgClosure *)NULL, 0, 0);
emitSchedule = rtsFalse;
}
-
-# endif
-#else /* !GRAN && !PAR */
-
- // grab a thread from the run queue
- ASSERT(run_queue_hd != END_TSO_QUEUE);
- POP_RUN_QUEUE(t);
-
- // Sanity check the thread we're about to run. This can be
- // expensive if there is lots of thread switching going on...
- IF_DEBUG(sanity,checkTSO(t));
-#endif
-
-#ifdef THREADED_RTS
- {
- StgMainThread *m = t->main;
-
- if(m)
- {
- if(m == mainThread)
- {
- IF_DEBUG(scheduler,
- sched_belch("### Running thread %d in bound thread", t->id));
- // yes, the Haskell thread is bound to the current native thread
- }
- else
- {
- IF_DEBUG(scheduler,
- sched_belch("### thread %d bound to another OS thread", t->id));
- // no, bound to a different Haskell thread: pass to that thread
- PUSH_ON_RUN_QUEUE(t);
- passCapability(&m->bound_thread_cond);
- continue;
- }
- }
- else
- {
- if(mainThread != NULL)
- // The thread we want to run is bound.
- {
- IF_DEBUG(scheduler,
- sched_belch("### this OS thread cannot run thread %d", t->id));
- // no, the current native thread is bound to a different
- // Haskell thread, so pass it to any worker thread
- PUSH_ON_RUN_QUEUE(t);
- passCapabilityToWorker();
- continue;
- }
- }
- }
-#endif
-
- cap->r.rCurrentTSO = t;
-
- /* context switches are now initiated by the timer signal, unless
- * the user specified "context switch as often as possible", with
- * +RTS -C0
- */
- if ((RtsFlags.ConcFlags.ctxtSwitchTicks == 0
- && (run_queue_hd != END_TSO_QUEUE
- || blocked_queue_hd != END_TSO_QUEUE
- || sleeping_queue != END_TSO_QUEUE)))
- context_switch = 1;
-
-run_thread:
-
- RELEASE_LOCK(&sched_mutex);
-
- IF_DEBUG(scheduler, sched_belch("-->> running thread %ld %s ...",
- (long)t->id, whatNext_strs[t->what_next]));
-
-#ifdef PROFILING
- startHeapProfTimer();
+}
#endif
- /* +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ */
- /* Run the current thread
- */
- prev_what_next = t->what_next;
-
- errno = t->saved_errno;
-
- switch (prev_what_next) {
-
- case ThreadKilled:
- case ThreadComplete:
- /* Thread already finished, return to scheduler. */
- ret = ThreadFinished;
- break;
-
- case ThreadRunGHC:
- ret = StgRun((StgFunPtr) stg_returnToStackTop, &cap->r);
- break;
-
- case ThreadInterpret:
- ret = interpretBCO(cap);
- break;
-
- default:
- barf("schedule: invalid what_next field");
- }
-
- // The TSO might have moved, so find the new location:
- t = cap->r.rCurrentTSO;
-
- // And save the current errno in this thread.
- t->saved_errno = errno;
+/* ----------------------------------------------------------------------------
+ * After running a thread...
+ * ASSUMES: sched_mutex
+ * ------------------------------------------------------------------------- */
- /* +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ */
-
- /* Costs for the scheduler are assigned to CCS_SYSTEM */
-#ifdef PROFILING
- stopHeapProfTimer();
- CCCS = CCS_SYSTEM;
-#endif
-
- ACQUIRE_LOCK(&sched_mutex);
-
-#ifdef RTS_SUPPORTS_THREADS
- IF_DEBUG(scheduler,debugBelch("sched (task %p): ", osThreadId()););
-#elif !defined(GRAN) && !defined(PAR)
- IF_DEBUG(scheduler,debugBelch("sched: "););
-#endif
-
+static void
+schedulePostRunThread(void)
+{
#if defined(PAR)
/* HACK 675: if the last thread didn't yield, make sure to print a
SCHEDULE event to the log file when StgRunning the next thread, even
TimeOfLastYield = CURRENT_TIME;
#endif
- switch (ret) {
+ /* some statistics gathering in the parallel case */
+
+#if defined(GRAN) || defined(PAR) || defined(EDEN)
+ switch (ret) {
case HeapOverflow:
-#if defined(GRAN)
+# if defined(GRAN)
IF_DEBUG(gran, DumpGranEvent(GR_DESCHEDULE, t));
globalGranStats.tot_heapover++;
-#elif defined(PAR)
+# elif defined(PAR)
globalParStats.tot_heapover++;
-#endif
+# endif
+ break;
- // did the task ask for a large block?
- if (cap->r.rHpAlloc > BLOCK_SIZE) {
- // if so, get one and push it on the front of the nursery.
- bdescr *bd;
- nat blocks;
-
- blocks = (nat)BLOCK_ROUND_UP(cap->r.rHpAlloc) / BLOCK_SIZE;
+ case StackOverflow:
+# if defined(GRAN)
+ IF_DEBUG(gran,
+ DumpGranEvent(GR_DESCHEDULE, t));
+ globalGranStats.tot_stackover++;
+# elif defined(PAR)
+ // IF_DEBUG(par,
+ // DumpGranEvent(GR_DESCHEDULE, t);
+ globalParStats.tot_stackover++;
+# endif
+ break;
- IF_DEBUG(scheduler,debugBelch("--<< thread %ld (%s) stopped: requesting a large block (size %d)\n",
- (long)t->id, whatNext_strs[t->what_next], blocks));
+ case ThreadYielding:
+# if defined(GRAN)
+ IF_DEBUG(gran,
+ DumpGranEvent(GR_DESCHEDULE, t));
+ globalGranStats.tot_yields++;
+# elif defined(PAR)
+ // IF_DEBUG(par,
+ // DumpGranEvent(GR_DESCHEDULE, t);
+ globalParStats.tot_yields++;
+# endif
+ break;
- // don't do this if it would push us over the
- // alloc_blocks_lim limit; we'll GC first.
- if (alloc_blocks + blocks < alloc_blocks_lim) {
+ case ThreadBlocked:
+# if defined(GRAN)
+ IF_DEBUG(scheduler,
+ debugBelch("--<< thread %ld (%p; %s) stopped, blocking on node %p [PE %d] with BQ: ",
+ t->id, t, whatNext_strs[t->what_next], t->block_info.closure,
+ (t->block_info.closure==(StgClosure*)NULL ? 99 : where_is(t->block_info.closure)));
+ if (t->block_info.closure!=(StgClosure*)NULL)
+ print_bq(t->block_info.closure);
+ debugBelch("\n"));
- alloc_blocks += blocks;
- bd = allocGroup( blocks );
+ // ??? 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;
- // link the new group into the list
- bd->link = cap->r.rCurrentNursery;
- bd->u.back = cap->r.rCurrentNursery->u.back;
- if (cap->r.rCurrentNursery->u.back != NULL) {
- cap->r.rCurrentNursery->u.back->link = bd;
- } else {
- ASSERT(g0s0->blocks == cap->r.rCurrentNursery &&
- g0s0->blocks == cap->r.rNursery);
- cap->r.rNursery = g0s0->blocks = bd;
- }
- cap->r.rCurrentNursery->u.back = bd;
-
- // initialise it as a nursery block. We initialise the
- // step, gen_no, and flags field of *every* sub-block in
- // this large block, because this is easier than making
- // sure that we always find the block head of a large
- // block whenever we call Bdescr() (eg. evacuate() and
- // isAlive() in the GC would both have to do this, at
- // least).
- {
- bdescr *x;
- for (x = bd; x < bd + blocks; x++) {
- x->step = g0s0;
- x->gen_no = 0;
- x->flags = 0;
- }
- }
+ case ThreadFinished:
+ break;
- // don't forget to update the block count in g0s0.
- g0s0->n_blocks += blocks;
- // This assert can be a killer if the app is doing lots
- // of large block allocations.
- ASSERT(countBlocks(g0s0->blocks) == g0s0->n_blocks);
-
- // now update the nursery to point to the new block
- cap->r.rCurrentNursery = bd;
-
- // we might be unlucky and have another thread get on the
- // run queue before us and steal the large block, but in that
- // case the thread will just end up requesting another large
- // block.
- PUSH_ON_RUN_QUEUE(t);
- break;
- }
- }
+ default:
+ barf("parGlobalStats: unknown return code");
+ break;
+ }
+#endif
+}
- /* make all the running tasks block on a condition variable,
- * maybe set context_switch and wait till they all pile in,
- * then have them wait on a GC condition variable.
- */
- IF_DEBUG(scheduler,debugBelch("--<< thread %ld (%s) stopped: HeapOverflow\n",
- (long)t->id, whatNext_strs[t->what_next]));
- threadPaused(t);
+/* -----------------------------------------------------------------------------
+ * Handle a thread that returned to the scheduler with ThreadHeepOverflow
+ * ASSUMES: sched_mutex
+ * -------------------------------------------------------------------------- */
+
+static rtsBool
+scheduleHandleHeapOverflow( Capability *cap, StgTSO *t )
+{
+ // did the task ask for a large block?
+ if (cap->r.rHpAlloc > BLOCK_SIZE) {
+ // if so, get one and push it on the front of the nursery.
+ bdescr *bd;
+ lnat blocks;
+
+ blocks = (lnat)BLOCK_ROUND_UP(cap->r.rHpAlloc) / BLOCK_SIZE;
+
+ IF_DEBUG(scheduler,
+ debugBelch("--<< thread %ld (%s) stopped: requesting a large block (size %ld)\n",
+ (long)t->id, whatNext_strs[t->what_next], blocks));
+
+ // don't do this if the nursery is (nearly) full, we'll GC first.
+ if (cap->r.rCurrentNursery->link != NULL ||
+ cap->r.rNursery->n_blocks == 1) { // paranoia to prevent infinite loop
+ // if the nursery has only one block.
+
+ ACQUIRE_SM_LOCK
+ bd = allocGroup( blocks );
+ RELEASE_SM_LOCK
+ cap->r.rNursery->n_blocks += blocks;
+
+ // link the new group into the list
+ bd->link = cap->r.rCurrentNursery;
+ bd->u.back = cap->r.rCurrentNursery->u.back;
+ if (cap->r.rCurrentNursery->u.back != NULL) {
+ cap->r.rCurrentNursery->u.back->link = bd;
+ } else {
+#if !defined(SMP)
+ ASSERT(g0s0->blocks == cap->r.rCurrentNursery &&
+ g0s0 == cap->r.rNursery);
+#endif
+ cap->r.rNursery->blocks = bd;
+ }
+ cap->r.rCurrentNursery->u.back = bd;
+
+ // initialise it as a nursery block. We initialise the
+ // step, gen_no, and flags field of *every* sub-block in
+ // this large block, because this is easier than making
+ // sure that we always find the block head of a large
+ // block whenever we call Bdescr() (eg. evacuate() and
+ // isAlive() in the GC would both have to do this, at
+ // least).
+ {
+ bdescr *x;
+ for (x = bd; x < bd + blocks; x++) {
+ x->step = cap->r.rNursery;
+ x->gen_no = 0;
+ x->flags = 0;
+ }
+ }
+
+ // This assert can be a killer if the app is doing lots
+ // of large block allocations.
+ IF_DEBUG(sanity, checkNurserySanity(cap->r.rNursery));
+
+ // now update the nursery to point to the new block
+ cap->r.rCurrentNursery = bd;
+
+ // we might be unlucky and have another thread get on the
+ // run queue before us and steal the large block, but in that
+ // case the thread will just end up requesting another large
+ // block.
+ PUSH_ON_RUN_QUEUE(t);
+ return rtsFalse; /* not actually GC'ing */
+ }
+ }
+
+ IF_DEBUG(scheduler,
+ debugBelch("--<< thread %ld (%s) stopped: HeapOverflow\n",
+ (long)t->id, whatNext_strs[t->what_next]));
#if defined(GRAN)
- ASSERT(!is_on_queue(t,CurrentProc));
-#elif defined(PAR)
- /* Currently we emit a DESCHEDULE event before GC in GUM.
- ToDo: either add separate event to distinguish SYSTEM time from rest
- or just nuke this DESCHEDULE (and the following SCHEDULE) */
- if (0 && RtsFlags.ParFlags.ParStats.Full) {
+ ASSERT(!is_on_queue(t,CurrentProc));
+#elif defined(PARALLEL_HASKELL)
+ /* Currently we emit a DESCHEDULE event before GC in GUM.
+ ToDo: either add separate event to distinguish SYSTEM time from rest
+ or just nuke this DESCHEDULE (and the following SCHEDULE) */
+ if (0 && RtsFlags.ParFlags.ParStats.Full) {
DumpRawGranEvent(CURRENT_PROC, CURRENT_PROC,
GR_DESCHEDULE, t, (StgClosure *)NULL, 0, 0);
emitSchedule = rtsTrue;
- }
+ }
#endif
- ready_to_gc = rtsTrue;
- context_switch = 1; /* stop other threads ASAP */
- PUSH_ON_RUN_QUEUE(t);
- /* actual GC is done at the end of the while loop */
- break;
-
- case StackOverflow:
-#if defined(GRAN)
- IF_DEBUG(gran,
- DumpGranEvent(GR_DESCHEDULE, t));
- globalGranStats.tot_stackover++;
-#elif defined(PAR)
- // IF_DEBUG(par,
- // DumpGranEvent(GR_DESCHEDULE, t);
- globalParStats.tot_stackover++;
-#endif
- IF_DEBUG(scheduler,debugBelch("--<< thread %ld (%s) stopped, StackOverflow\n",
- (long)t->id, whatNext_strs[t->what_next]));
- /* just adjust the stack for this thread, then pop it back
- * on the run queue.
- */
- threadPaused(t);
- {
+ PUSH_ON_RUN_QUEUE(t);
+ return rtsTrue;
+ /* actual GC is done at the end of the while loop in schedule() */
+}
+
+/* -----------------------------------------------------------------------------
+ * Handle a thread that returned to the scheduler with ThreadStackOverflow
+ * ASSUMES: sched_mutex
+ * -------------------------------------------------------------------------- */
+
+static void
+scheduleHandleStackOverflow( StgTSO *t)
+{
+ IF_DEBUG(scheduler,debugBelch("--<< thread %ld (%s) stopped, StackOverflow\n",
+ (long)t->id, whatNext_strs[t->what_next]));
+ /* just adjust the stack for this thread, then pop it back
+ * on the run queue.
+ */
+ {
/* enlarge the stack */
StgTSO *new_t = threadStackOverflow(t);
t->main->tso = new_t;
}
PUSH_ON_RUN_QUEUE(new_t);
- }
- break;
+ }
+}
- case ThreadYielding:
- // Reset the context switch flag. We don't do this just before
- // running the thread, because that would mean we would lose ticks
- // during GC, which can lead to unfair scheduling (a thread hogs
- // the CPU because the tick always arrives during GC). This way
- // penalises threads that do a lot of allocation, but that seems
- // better than the alternative.
- context_switch = 0;
+/* -----------------------------------------------------------------------------
+ * Handle a thread that returned to the scheduler with ThreadYielding
+ * ASSUMES: sched_mutex
+ * -------------------------------------------------------------------------- */
+static rtsBool
+scheduleHandleYield( StgTSO *t, nat prev_what_next )
+{
+ // Reset the context switch flag. We don't do this just before
+ // running the thread, because that would mean we would lose ticks
+ // during GC, which can lead to unfair scheduling (a thread hogs
+ // the CPU because the tick always arrives during GC). This way
+ // penalises threads that do a lot of allocation, but that seems
+ // better than the alternative.
+ context_switch = 0;
+
+ /* put the thread back on the run queue. Then, if we're ready to
+ * GC, check whether this is the last task to stop. If so, wake
+ * up the GC thread. getThread will block during a GC until the
+ * GC is finished.
+ */
+ IF_DEBUG(scheduler,
+ if (t->what_next != prev_what_next) {
+ debugBelch("--<< thread %ld (%s) stopped to switch evaluators\n",
+ (long)t->id, whatNext_strs[t->what_next]);
+ } else {
+ debugBelch("--<< thread %ld (%s) stopped, yielding\n",
+ (long)t->id, whatNext_strs[t->what_next]);
+ }
+ );
+
+ IF_DEBUG(sanity,
+ //debugBelch("&& Doing sanity check on yielding TSO %ld.", t->id);
+ checkTSO(t));
+ ASSERT(t->link == END_TSO_QUEUE);
+
+ // Shortcut if we're just switching evaluators: don't bother
+ // doing stack squeezing (which can be expensive), just run the
+ // thread.
+ if (t->what_next != prev_what_next) {
+ return rtsTrue;
+ }
+
#if defined(GRAN)
- IF_DEBUG(gran,
- DumpGranEvent(GR_DESCHEDULE, t));
- globalGranStats.tot_yields++;
-#elif defined(PAR)
- // IF_DEBUG(par,
- // DumpGranEvent(GR_DESCHEDULE, t);
- globalParStats.tot_yields++;
+ ASSERT(!is_on_queue(t,CurrentProc));
+
+ IF_DEBUG(sanity,
+ //debugBelch("&& Doing sanity check on all ThreadQueues (and their TSOs).");
+ checkThreadQsSanity(rtsTrue));
+
#endif
- /* put the thread back on the run queue. Then, if we're ready to
- * GC, check whether this is the last task to stop. If so, wake
- * up the GC thread. getThread will block during a GC until the
- * GC is finished.
- */
- IF_DEBUG(scheduler,
- if (t->what_next != prev_what_next) {
- debugBelch("--<< thread %ld (%s) stopped to switch evaluators\n",
- (long)t->id, whatNext_strs[t->what_next]);
- } else {
- debugBelch("--<< thread %ld (%s) stopped, yielding\n",
- (long)t->id, whatNext_strs[t->what_next]);
- }
- );
-
- IF_DEBUG(sanity,
- //debugBelch("&& Doing sanity check on yielding TSO %ld.", t->id);
- checkTSO(t));
- ASSERT(t->link == END_TSO_QUEUE);
-
- // Shortcut if we're just switching evaluators: don't bother
- // doing stack squeezing (which can be expensive), just run the
- // thread.
- if (t->what_next != prev_what_next) {
- goto run_thread;
- }
- threadPaused(t);
+ addToRunQueue(t);
#if defined(GRAN)
- ASSERT(!is_on_queue(t,CurrentProc));
-
- IF_DEBUG(sanity,
- //debugBelch("&& Doing sanity check on all ThreadQueues (and their TSOs).");
- checkThreadQsSanity(rtsTrue));
-#endif
-
-#if defined(PAR)
- if (RtsFlags.ParFlags.doFairScheduling) {
- /* this does round-robin scheduling; good for concurrency */
- APPEND_TO_RUN_QUEUE(t);
- } else {
- /* this does unfair scheduling; good for parallelism */
- PUSH_ON_RUN_QUEUE(t);
- }
-#else
- // this does round-robin scheduling; good for concurrency
- APPEND_TO_RUN_QUEUE(t);
+ /* add a ContinueThread event to actually process the thread */
+ new_event(CurrentProc, CurrentProc, CurrentTime[CurrentProc],
+ ContinueThread,
+ t, (StgClosure*)NULL, (rtsSpark*)NULL);
+ IF_GRAN_DEBUG(bq,
+ debugBelch("GRAN: eventq and runnableq after adding yielded thread to queue again:\n");
+ G_EVENTQ(0);
+ G_CURR_THREADQ(0));
#endif
+ return rtsFalse;
+}
-#if defined(GRAN)
- /* add a ContinueThread event to actually process the thread */
- new_event(CurrentProc, CurrentProc, CurrentTime[CurrentProc],
- ContinueThread,
- t, (StgClosure*)NULL, (rtsSpark*)NULL);
- IF_GRAN_DEBUG(bq,
- debugBelch("GRAN: eventq and runnableq after adding yielded thread to queue again:\n");
- G_EVENTQ(0);
- G_CURR_THREADQ(0));
-#endif /* GRAN */
- break;
+/* -----------------------------------------------------------------------------
+ * Handle a thread that returned to the scheduler with ThreadBlocked
+ * ASSUMES: sched_mutex
+ * -------------------------------------------------------------------------- */
- case ThreadBlocked:
+static void
+scheduleHandleThreadBlocked( StgTSO *t
+#if !defined(GRAN) && !defined(DEBUG)
+ STG_UNUSED
+#endif
+ )
+{
#if defined(GRAN)
- IF_DEBUG(scheduler,
- debugBelch("--<< thread %ld (%p; %s) stopped, blocking on node %p [PE %d] with BQ: \n",
- t->id, t, whatNext_strs[t->what_next], t->block_info.closure, (t->block_info.closure==(StgClosure*)NULL ? 99 : where_is(t->block_info.closure)));
- if (t->block_info.closure!=(StgClosure*)NULL) print_bq(t->block_info.closure));
-
- // ??? needed; should emit block before
- IF_DEBUG(gran,
- DumpGranEvent(GR_DESCHEDULE, t));
- prune_eventq(t, (StgClosure *)NULL); // prune ContinueThreads for t
- /*
- ngoq Dogh!
+ IF_DEBUG(scheduler,
+ debugBelch("--<< thread %ld (%p; %s) stopped, blocking on node %p [PE %d] with BQ: \n",
+ t->id, t, whatNext_strs[t->what_next], t->block_info.closure, (t->block_info.closure==(StgClosure*)NULL ? 99 : where_is(t->block_info.closure)));
+ if (t->block_info.closure!=(StgClosure*)NULL) print_bq(t->block_info.closure));
+
+ // ??? needed; should emit block before
+ IF_DEBUG(gran,
+ DumpGranEvent(GR_DESCHEDULE, t));
+ prune_eventq(t, (StgClosure *)NULL); // prune ContinueThreads for t
+ /*
+ ngoq Dogh!
ASSERT(procStatus[CurrentProc]==Busy ||
- ((procStatus[CurrentProc]==Fetching) &&
- (t->block_info.closure!=(StgClosure*)NULL)));
+ ((procStatus[CurrentProc]==Fetching) &&
+ (t->block_info.closure!=(StgClosure*)NULL)));
if (run_queue_hds[CurrentProc] == END_TSO_QUEUE &&
- !(!RtsFlags.GranFlags.DoAsyncFetch &&
- procStatus[CurrentProc]==Fetching))
- procStatus[CurrentProc] = Idle;
- */
+ !(!RtsFlags.GranFlags.DoAsyncFetch &&
+ procStatus[CurrentProc]==Fetching))
+ procStatus[CurrentProc] = Idle;
+ */
#elif defined(PAR)
- IF_DEBUG(scheduler,
- debugBelch("--<< thread %ld (%p; %s) stopped, blocking on node %p with BQ: \n",
- t->id, t, whatNext_strs[t->what_next], t->block_info.closure));
- IF_PAR_DEBUG(bq,
+ IF_DEBUG(scheduler,
+ debugBelch("--<< thread %ld (%p; %s) stopped, blocking on node %p with BQ: \n",
+ t->id, t, whatNext_strs[t->what_next], t->block_info.closure));
+ IF_PAR_DEBUG(bq,
+
+ if (t->block_info.closure!=(StgClosure*)NULL)
+ print_bq(t->block_info.closure));
+
+ /* Send a fetch (if BlockedOnGA) and dump event to log file */
+ blockThread(t);
+
+ /* whatever we schedule next, we must log that schedule */
+ emitSchedule = rtsTrue;
+
+#else /* !GRAN */
- if (t->block_info.closure!=(StgClosure*)NULL)
- print_bq(t->block_info.closure));
+ // We don't need to do anything. The thread is blocked, and it
+ // has tidied up its stack and placed itself on whatever queue
+ // it needs to be on.
- /* Send a fetch (if BlockedOnGA) and dump event to log file */
- blockThread(t);
+#if !defined(SMP)
+ ASSERT(t->why_blocked != NotBlocked);
+ // This might not be true under SMP: we don't have
+ // exclusive access to this TSO, so someone might have
+ // woken it up by now. This actually happens: try
+ // conc023 +RTS -N2.
+#endif
- /* whatever we schedule next, we must log that schedule */
- emitSchedule = rtsTrue;
+ IF_DEBUG(scheduler,
+ debugBelch("--<< thread %d (%s) stopped: ",
+ t->id, whatNext_strs[t->what_next]);
+ printThreadBlockage(t);
+ debugBelch("\n"));
+
+ /* Only for dumping event to log file
+ ToDo: do I need this in GranSim, too?
+ blockThread(t);
+ */
+#endif
+}
-#else /* !GRAN */
- /* don't need to do anything. Either the thread is blocked on
- * I/O, in which case we'll have called addToBlockedQueue
- * previously, or it's blocked on an MVar or Blackhole, in which
- * case it'll be on the relevant queue already.
- */
- IF_DEBUG(scheduler,
- debugBelch("--<< thread %d (%s) stopped: ",
- t->id, whatNext_strs[t->what_next]);
- printThreadBlockage(t);
- debugBelch("\n"));
+/* -----------------------------------------------------------------------------
+ * Handle a thread that returned to the scheduler with ThreadFinished
+ * ASSUMES: sched_mutex
+ * -------------------------------------------------------------------------- */
- /* Only for dumping event to log file
- ToDo: do I need this in GranSim, too?
- blockThread(t);
- */
-#endif
- threadPaused(t);
- break;
+static rtsBool
+scheduleHandleThreadFinished( StgMainThread *mainThread
+ USED_WHEN_RTS_SUPPORTS_THREADS,
+ Capability *cap,
+ StgTSO *t )
+{
+ /* Need to check whether this was a main thread, and if so,
+ * return with the return value.
+ *
+ * We also end up here if the thread kills itself with an
+ * uncaught exception, see Exception.cmm.
+ */
+ IF_DEBUG(scheduler,debugBelch("--++ thread %d (%s) finished\n",
+ t->id, whatNext_strs[t->what_next]));
- case ThreadFinished:
- /* Need to check whether this was a main thread, and if so, signal
- * the task that started it with the return value. If we have no
- * more main threads, we probably need to stop all the tasks until
- * we get a new one.
- */
- /* We also end up here if the thread kills itself with an
- * uncaught exception, see Exception.hc.
- */
- IF_DEBUG(scheduler,debugBelch("--++ thread %d (%s) finished\n",
- t->id, whatNext_strs[t->what_next]));
#if defined(GRAN)
endThread(t, CurrentProc); // clean-up the thread
-#elif defined(PAR)
+#elif defined(PARALLEL_HASKELL)
/* For now all are advisory -- HWL */
//if(t->priority==AdvisoryPriority) ??
- advisory_thread_count--;
+ advisory_thread_count--; // JB: Caution with this counter, buggy!
-# ifdef DIST
+# if defined(DIST)
if(t->dist.priority==RevalPriority)
FinishReval(t);
# endif
-
+
+# if defined(EDENOLD)
+ // the thread could still have an outport... (BUG)
+ if (t->eden.outport != -1) {
+ // delete the outport for the tso which has finished...
+ IF_PAR_DEBUG(eden_ports,
+ debugBelch("WARNING: Scheduler removes outport %d for TSO %d.\n",
+ t->eden.outport, t->id));
+ deleteOPT(t);
+ }
+ // thread still in the process (HEAVY BUG! since outport has just been closed...)
+ if (t->eden.epid != -1) {
+ IF_PAR_DEBUG(eden_ports,
+ debugBelch("WARNING: Scheduler removes TSO %d from process %d .\n",
+ t->id, t->eden.epid));
+ removeTSOfromProcess(t);
+ }
+# endif
+
+# if defined(PAR)
if (RtsFlags.ParFlags.ParStats.Full &&
!RtsFlags.ParFlags.ParStats.Suppressed)
DumpEndEvent(CURRENT_PROC, t, rtsFalse /* not mandatory */);
-#endif
+
+ // t->par only contains statistics: left out for now...
+ IF_PAR_DEBUG(fish,
+ debugBelch("**** end thread: ended sparked thread %d (%lx); sparkname: %lx\n",
+ t->id,t,t->par.sparkname));
+# endif
+#endif // PARALLEL_HASKELL
//
// Check whether the thread that just completed was a main
if (mainThread->ret) {
*(mainThread->ret) = NULL;
}
- if (was_interrupted) {
+ if (interrupted) {
mainThread->stat = Interrupted;
} else {
mainThread->stat = Killed;
removeThreadLabel((StgWord)mainThread->tso->id);
#endif
if (mainThread->prev == NULL) {
+ ASSERT(mainThread == main_threads);
main_threads = mainThread->link;
} else {
mainThread->prev->link = mainThread->link;
}
if (mainThread->link != NULL) {
- mainThread->link->prev = NULL;
+ mainThread->link->prev = mainThread->prev;
}
releaseCapability(cap);
- return;
+ return rtsTrue; // tells schedule() to return
}
#ifdef RTS_SUPPORTS_THREADS
APPEND_TO_RUN_QUEUE(t);
}
#endif
- break;
+ return rtsFalse;
+}
- default:
- barf("schedule: invalid thread return code %d", (int)ret);
- }
+/* -----------------------------------------------------------------------------
+ * Perform a heap census, if PROFILING
+ * -------------------------------------------------------------------------- */
-#ifdef PROFILING
+static rtsBool
+scheduleDoHeapProfile( rtsBool ready_to_gc STG_UNUSED )
+{
+#if defined(PROFILING)
// When we have +RTS -i0 and we're heap profiling, do a census at
// every GC. This lets us get repeatable runs for debugging.
if (performHeapProfile ||
GarbageCollect(GetRoots, rtsTrue);
heapCensus();
performHeapProfile = rtsFalse;
- ready_to_gc = rtsFalse; // we already GC'd
+ return rtsTrue; // true <=> we already GC'd
}
#endif
+ return rtsFalse;
+}
- if (ready_to_gc) {
- /* everybody back, start the GC.
- * Could do it in this thread, or signal a condition var
- * to do it in another thread. Either way, we need to
- * broadcast on gc_pending_cond afterward.
- */
-#if defined(RTS_SUPPORTS_THREADS)
- IF_DEBUG(scheduler,sched_belch("doing GC"));
+/* -----------------------------------------------------------------------------
+ * Perform a garbage collection if necessary
+ * ASSUMES: sched_mutex
+ * -------------------------------------------------------------------------- */
+
+static void
+scheduleDoGC( rtsBool force_major )
+{
+ StgTSO *t;
+#ifdef SMP
+ Capability *cap;
+ static rtsBool waiting_for_gc;
+ int n_capabilities = RtsFlags.ParFlags.nNodes - 1;
+ // subtract one because we're already holding one.
+ Capability *caps[n_capabilities];
#endif
- GarbageCollect(GetRoots,rtsFalse);
- ready_to_gc = rtsFalse;
-#if defined(GRAN)
- /* add a ContinueThread event to continue execution of current thread */
- new_event(CurrentProc, CurrentProc, CurrentTime[CurrentProc],
- ContinueThread,
- t, (StgClosure*)NULL, (rtsSpark*)NULL);
- IF_GRAN_DEBUG(bq,
- debugBelch("GRAN: eventq and runnableq after Garbage collection:\n\n");
- G_EVENTQ(0);
- G_CURR_THREADQ(0));
-#endif /* GRAN */
+
+#ifdef SMP
+ // In order to GC, there must be no threads running Haskell code.
+ // Therefore, the GC thread needs to hold *all* the capabilities,
+ // and release them after the GC has completed.
+ //
+ // This seems to be the simplest way: previous attempts involved
+ // making all the threads with capabilities give up their
+ // capabilities and sleep except for the *last* one, which
+ // actually did the GC. But it's quite hard to arrange for all
+ // the other tasks to sleep and stay asleep.
+ //
+ // This does mean that there will be multiple entries in the
+ // thread->capability hash table for the current thread, but
+ // they will be removed as normal when the capabilities are
+ // released again.
+ //
+
+ // Someone else is already trying to GC
+ if (waiting_for_gc) return;
+ waiting_for_gc = rtsTrue;
+
+ while (n_capabilities > 0) {
+ IF_DEBUG(scheduler, sched_belch("ready_to_gc, grabbing all the capabilies (%d left)", n_capabilities));
+ waitForReturnCapability(&sched_mutex, &cap);
+ n_capabilities--;
+ caps[n_capabilities] = cap;
}
-#if defined(GRAN)
- next_thread:
- IF_GRAN_DEBUG(unused,
- print_eventq(EventHd));
+ waiting_for_gc = rtsFalse;
+#endif
- event = get_next_event();
-#elif defined(PAR)
- next_thread:
- /* ToDo: wait for next message to arrive rather than busy wait */
-#endif /* GRAN */
+ /* Kick any transactions which are invalid back to their
+ * atomically frames. When next scheduled they will try to
+ * commit, this commit will fail and they will retry.
+ */
+ {
+ StgTSO *next;
+
+ for (t = all_threads; t != END_TSO_QUEUE; t = next) {
+ if (t->what_next == ThreadRelocated) {
+ next = t->link;
+ } else {
+ next = t->global_link;
+ if (t -> trec != NO_TREC && t -> why_blocked == NotBlocked) {
+ if (!stmValidateNestOfTransactions (t -> trec)) {
+ IF_DEBUG(stm, sched_belch("trec %p found wasting its time", t));
+
+ // strip the stack back to the ATOMICALLY_FRAME, aborting
+ // the (nested) transaction, and saving the stack of any
+ // partially-evaluated thunks on the heap.
+ raiseAsync_(t, NULL, rtsTrue);
+
+#ifdef REG_R1
+ ASSERT(get_itbl((StgClosure *)t->sp)->type == ATOMICALLY_FRAME);
+#endif
+ }
+ }
+ }
+ }
+ }
+
+ // so this happens periodically:
+ scheduleCheckBlackHoles();
+
+ IF_DEBUG(scheduler, printAllThreads());
- } /* end of while(1) */
+ /* everybody back, start the GC.
+ * Could do it in this thread, or signal a condition var
+ * to do it in another thread. Either way, we need to
+ * broadcast on gc_pending_cond afterward.
+ */
+#if defined(RTS_SUPPORTS_THREADS)
+ IF_DEBUG(scheduler,sched_belch("doing GC"));
+#endif
+ GarbageCollect(GetRoots, force_major);
+
+#if defined(SMP)
+ {
+ // release our stash of capabilities.
+ nat i;
+ for (i = 0; i < RtsFlags.ParFlags.nNodes-1; i++) {
+ releaseCapability(caps[i]);
+ }
+ }
+#endif
- IF_PAR_DEBUG(verbose,
- debugBelch("== Leaving schedule() after having received Finish\n"));
+#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 */
}
/* ---------------------------------------------------------------------------
StgBool
rtsSupportsBoundThreads(void)
{
-#ifdef THREADED_RTS
+#if defined(RTS_SUPPORTS_THREADS)
return rtsTrue;
#else
return rtsFalse;
StgBool
isThreadBound(StgTSO* tso USED_IN_THREADED_RTS)
{
-#ifdef THREADED_RTS
+#if defined(RTS_SUPPORTS_THREADS)
return (tso->main != NULL);
#endif
return rtsFalse;
* Singleton fork(). Do not copy any running threads.
* ------------------------------------------------------------------------- */
-#ifndef mingw32_TARGET_OS
+#ifndef mingw32_HOST_OS
#define FORKPROCESS_PRIMOP_SUPPORTED
#endif
stgFree(m);
}
-# ifdef RTS_SUPPORTS_THREADS
- resetTaskManagerAfterFork(); // tell startTask() and friends that
- startingWorkerThread = rtsFalse; // we have no worker threads any more
- resetWorkerWakeupPipeAfterFork();
-# endif
-
rc = rts_evalStableIO(entry, NULL); // run the action
rts_checkSchedStatus("forkProcess",rc);
StgTSO* t, *next;
IF_DEBUG(scheduler,sched_belch("deleting all threads"));
for (t = all_threads; t != END_TSO_QUEUE; t = next) {
- next = t->global_link;
- deleteThread(t);
+ if (t->what_next == ThreadRelocated) {
+ next = t->link;
+ } else {
+ next = t->global_link;
+ deleteThread(t);
+ }
}
// The run queue now contains a bunch of ThreadKilled threads. We
// being GC'd, and we don't want the "main thread has been GC'd" panic.
ASSERT(blocked_queue_hd == END_TSO_QUEUE);
+ ASSERT(blackhole_queue == END_TSO_QUEUE);
ASSERT(sleeping_queue == END_TSO_QUEUE);
}
tok = cap->r.rCurrentTSO->id;
/* Hand back capability */
+ cap->r.rInHaskell = rtsFalse;
releaseCapability(cap);
#if defined(RTS_SUPPORTS_THREADS)
IF_DEBUG(scheduler, sched_belch("worker (token %d): leaving RTS", tok));
#endif
- /* Other threads _might_ be available for execution; signal this */
- THREAD_RUNNABLE();
RELEASE_LOCK(&sched_mutex);
errno = saved_errno;
tso->why_blocked = NotBlocked;
cap->r.rCurrentTSO = tso;
+ cap->r.rInHaskell = rtsTrue;
RELEASE_LOCK(&sched_mutex);
errno = saved_errno;
return &cap->r;
}
-
-/* ---------------------------------------------------------------------------
- * Static functions
- * ------------------------------------------------------------------------ */
-static void unblockThread(StgTSO *tso);
-
/* ---------------------------------------------------------------------------
* Comparing Thread ids.
*
createThread(nat size)
#endif
{
-
StgTSO *tso;
nat stack_size;
/* First check whether we should create a thread at all */
-#if defined(PAR)
+#if defined(PARALLEL_HASKELL)
/* check that no more than RtsFlags.ParFlags.maxThreads threads are created */
if (advisory_thread_count >= RtsFlags.ParFlags.maxThreads) {
threadsIgnored++;
- TSO_STRUCT_SIZEW;
tso->sp = (P_)&(tso->stack) + stack_size;
+ tso->trec = NO_TREC;
+
#ifdef PROFILING
tso->prof.CCCS = CCS_MAIN;
#endif
#if defined(GRAN)
if (RtsFlags.GranFlags.GranSimStats.Full)
DumpGranEvent(GR_START,tso);
-#elif defined(PAR)
+#elif defined(PARALLEL_HASKELL)
if (RtsFlags.ParFlags.ParStats.Full)
DumpGranEvent(GR_STARTQ,tso);
/* HACk to avoid SCHEDULE
tso->gran.clock = 0;
IF_DEBUG(gran,printTSO(tso));
-#elif defined(PAR)
+#elif defined(PARALLEL_HASKELL)
# if defined(DEBUG)
tso->par.magic = TSO_MAGIC; // debugging only
# endif
globalGranStats.threads_created_on_PE[CurrentProc]++;
globalGranStats.tot_sq_len += spark_queue_len(CurrentProc);
globalGranStats.tot_sq_probes++;
-#elif defined(PAR)
+#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) {
IF_GRAN_DEBUG(pri,
sched_belch("==__ schedule: Created TSO %d (%p);",
CurrentProc, tso, tso->id));
-#elif defined(PAR)
- IF_PAR_DEBUG(verbose,
- sched_belch("==__ schedule: Created TSO %d (%p); %d threads active",
- (long)tso->id, tso, advisory_thread_count));
+#elif defined(PARALLEL_HASKELL)
+ IF_PAR_DEBUG(verbose,
+ sched_belch("==__ schedule: Created TSO %d (%p); %d threads active",
+ (long)tso->id, tso, advisory_thread_count));
#else
IF_DEBUG(scheduler,sched_belch("created thread %ld, stack size = %lx words",
- (long)tso->id, (long)tso->stack_size));
+ (long)tso->id, (long)tso->stack_size));
#endif
return tso;
}
all parallel thread creation calls should fall through the following routine.
*/
StgTSO *
-createSparkThread(rtsSpark spark)
+createThreadFromSpark(rtsSpark spark)
{ StgTSO *tso;
ASSERT(spark != (rtsSpark)NULL);
+// JB: TAKE CARE OF THIS COUNTER! BUGGY
if (advisory_thread_count >= RtsFlags.ParFlags.maxThreads)
{ threadsIgnored++;
barf("{createSparkThread}Daq ghuH: refusing to create another thread; no more than %d threads allowed (currently %d)",
tso->priority = AdvisoryPriority;
#endif
pushClosure(tso,spark);
- PUSH_ON_RUN_QUEUE(tso);
- advisory_thread_count++;
+ addToRunQueue(tso);
+ advisory_thread_count++; // JB: TAKE CARE OF THIS COUNTER! BUGGY
}
return tso;
}
Turn a spark into a thread.
ToDo: fix for SMP (needs to acquire SCHED_MUTEX!)
*/
-#if defined(PAR)
+#if 0
StgTSO *
activateSpark (rtsSpark spark)
{
tso = createSparkThread(spark);
if (RtsFlags.ParFlags.ParStats.Full) {
//ASSERT(run_queue_hd == END_TSO_QUEUE); // I think ...
- IF_PAR_DEBUG(verbose,
- debugBelch("==^^ activateSpark: turning spark of closure %p (%s) into a thread\n",
- (StgClosure *)spark, info_type((StgClosure *)spark)));
+ IF_PAR_DEBUG(verbose,
+ debugBelch("==^^ activateSpark: turning spark of closure %p (%s) into a thread\n",
+ (StgClosure *)spark, info_type((StgClosure *)spark)));
}
// ToDo: fwd info on local/global spark to thread -- HWL
// tso->gran.exported = spark->exported;
}
#endif
-static SchedulerStatus waitThread_(/*out*/StgMainThread* m,
- Capability *initialCapability
- );
-
-
/* ---------------------------------------------------------------------------
* scheduleThread()
*
* on this thread's stack before the scheduler is invoked.
* ------------------------------------------------------------------------ */
-static void scheduleThread_ (StgTSO* tso);
-
void
-scheduleThread_(StgTSO *tso)
+scheduleThreadLocked(StgTSO *tso)
{
- // Precondition: sched_mutex must be held.
// The thread goes at the *end* of the run-queue, to avoid possible
// starvation of any threads already on the queue.
APPEND_TO_RUN_QUEUE(tso);
- THREAD_RUNNABLE();
+ threadRunnable();
}
void
scheduleThread(StgTSO* tso)
{
ACQUIRE_LOCK(&sched_mutex);
- scheduleThread_(tso);
+ scheduleThreadLocked(tso);
RELEASE_LOCK(&sched_mutex);
}
IF_DEBUG(scheduler, sched_belch("waiting for thread (%d)", tso->id));
APPEND_TO_RUN_QUEUE(tso);
- // NB. Don't call THREAD_RUNNABLE() here, because the thread is
+ // NB. Don't call threadRunnable() here, because the thread is
// bound and only runnable by *this* OS thread, so waking up other
// workers will just slow things down.
blocked_queue_hds[i] = END_TSO_QUEUE;
blocked_queue_tls[i] = END_TSO_QUEUE;
ccalling_threadss[i] = END_TSO_QUEUE;
+ blackhole_queue[i] = END_TSO_QUEUE;
sleeping_queue = END_TSO_QUEUE;
}
#else
run_queue_tl = END_TSO_QUEUE;
blocked_queue_hd = END_TSO_QUEUE;
blocked_queue_tl = END_TSO_QUEUE;
+ blackhole_queue = END_TSO_QUEUE;
sleeping_queue = END_TSO_QUEUE;
#endif
initCapabilities();
#if defined(RTS_SUPPORTS_THREADS)
- /* start our haskell execution tasks */
- startTaskManager(0,taskStart);
+ initTaskManager();
#endif
-#if /* defined(SMP) ||*/ defined(PAR)
+#if defined(SMP)
+ /* eagerly start some extra workers */
+ startingWorkerThread = RtsFlags.ParFlags.nNodes;
+ startTasks(RtsFlags.ParFlags.nNodes, taskStart);
+#endif
+
+#if /* defined(SMP) ||*/ defined(PARALLEL_HASKELL)
initSparkPools();
#endif
void
exitScheduler( void )
{
+ interrupted = rtsTrue;
+ shutting_down_scheduler = rtsTrue;
+
#if defined(RTS_SUPPORTS_THREADS)
- stopTaskManager();
+ if (threadIsTask(osThreadId())) { taskStop(); }
+ stopTaskManager();
+ //
+ // What can we do here? There are a bunch of worker threads, it
+ // might be nice to let them exit cleanly. There may be some main
+ // threads in the run queue; we should let them return to their
+ // callers with an Interrupted state. We can't in general wait
+ // for all the running Tasks to stop, because some might be off in
+ // a C call that is blocked.
+ //
+ // Letting the run queue drain is the safest thing. That lets any
+ // main threads return that can return, and cleans up all the
+ // runnable threads. Then we grab all the Capabilities to stop
+ // anything unexpected happening while we shut down.
+ //
+ // ToDo: this doesn't let us get the time stats from the worker
+ // tasks, because they haven't called taskStop().
+ //
+ ACQUIRE_LOCK(&sched_mutex);
+ {
+ nat i;
+ for (i = 1000; i > 0; i--) {
+ if (EMPTY_RUN_QUEUE()) {
+ IF_DEBUG(scheduler, sched_belch("run queue is empty"));
+ break;
+ }
+ IF_DEBUG(scheduler, sched_belch("yielding"));
+ RELEASE_LOCK(&sched_mutex);
+ prodWorker();
+ yieldThread();
+ ACQUIRE_LOCK(&sched_mutex);
+ }
+ }
+
+#ifdef SMP
+ {
+ Capability *cap;
+ int n_capabilities = RtsFlags.ParFlags.nNodes;
+ Capability *caps[n_capabilities];
+ nat i;
+
+ while (n_capabilities > 0) {
+ IF_DEBUG(scheduler, sched_belch("exitScheduler: grabbing all the capabilies (%d left)", n_capabilities));
+ waitForReturnCapability(&sched_mutex, &cap);
+ n_capabilities--;
+ caps[n_capabilities] = cap;
+ }
+ }
+#else
+ {
+ Capability *cap;
+ waitForReturnCapability(&sched_mutex, &cap);
+ }
+#endif
#endif
- shutting_down_scheduler = rtsTrue;
}
/* ----------------------------------------------------------------------------
ToDo: no support for two-space collection at the moment???
------------------------------------------------------------------------- */
-static
-SchedulerStatus
+static SchedulerStatus
waitThread_(StgMainThread* m, Capability *initialCapability)
{
SchedulerStatus stat;
}
#endif
+ if (blackhole_queue != END_TSO_QUEUE) {
+ evac((StgClosure **)&blackhole_queue);
+ }
+
if (suspended_ccalling_threads != END_TSO_QUEUE) {
evac((StgClosure **)&suspended_ccalling_threads);
}
-#if defined(PAR) || defined(GRAN)
+#if defined(PARALLEL_HASKELL) || defined(GRAN)
markSparkQueue(evac);
#endif
static StgTSO *
threadStackOverflow(StgTSO *tso)
{
- nat new_stack_size, new_tso_size, stack_words;
+ nat new_stack_size, stack_words;
+ lnat new_tso_size;
StgPtr new_sp;
StgTSO *dest;
* Finally round up so the TSO ends up as a whole number of blocks.
*/
new_stack_size = stg_min(tso->stack_size * 2, tso->max_stack_size);
- new_tso_size = (nat)BLOCK_ROUND_UP(new_stack_size * sizeof(W_) +
+ new_tso_size = (lnat)BLOCK_ROUND_UP(new_stack_size * sizeof(W_) +
TSO_STRUCT_SIZE)/sizeof(W_);
new_tso_size = round_to_mblocks(new_tso_size); /* Be MBLOCK-friendly */
new_stack_size = new_tso_size - TSO_STRUCT_SIZEW;
tso->link = dest;
tso->sp = (P_)&(tso->stack[tso->stack_size]);
tso->why_blocked = NotBlocked;
- dest->mut_link = NULL;
IF_PAR_DEBUG(verbose,
debugBelch("@@ threadStackOverflow of TSO %d (now at %p): stack size increased to %ld\n",
unblockCount ( StgBlockingQueueElement *bqe, StgClosure *node )
{
}
-#elif defined(PAR)
+#elif defined(PARALLEL_HASKELL)
STATIC_INLINE void
unblockCount ( StgBlockingQueueElement *bqe, StgClosure *node )
{
#endif
#if defined(GRAN)
-static StgBlockingQueueElement *
+StgBlockingQueueElement *
unblockOneLocked(StgBlockingQueueElement *bqe, StgClosure *node)
{
StgTSO *tso;
IF_DEBUG(scheduler,debugBelch("-- Waking up thread %ld (%p)\n",
tso->id, tso));
}
-#elif defined(PAR)
-static StgBlockingQueueElement *
+#elif defined(PARALLEL_HASKELL)
+StgBlockingQueueElement *
unblockOneLocked(StgBlockingQueueElement *bqe, StgClosure *node)
{
StgBlockingQueueElement *next;
next = bqe->link;
((StgTSO *)bqe)->link = END_TSO_QUEUE; // debugging?
APPEND_TO_RUN_QUEUE((StgTSO *)bqe);
- THREAD_RUNNABLE();
+ threadRunnable();
unblockCount(bqe, node);
/* reset blocking status after dumping event */
((StgTSO *)bqe)->why_blocked = NotBlocked;
return next;
}
-#else /* !GRAN && !PAR */
-static StgTSO *
+#else /* !GRAN && !PARALLEL_HASKELL */
+StgTSO *
unblockOneLocked(StgTSO *tso)
{
StgTSO *next;
next = tso->link;
tso->link = END_TSO_QUEUE;
APPEND_TO_RUN_QUEUE(tso);
- THREAD_RUNNABLE();
+ threadRunnable();
IF_DEBUG(scheduler,sched_belch("waking up thread %ld", (long)tso->id));
return next;
}
#endif
-#if defined(GRAN) || defined(PAR)
+#if defined(GRAN) || defined(PARALLEL_HASKELL)
INLINE_ME StgBlockingQueueElement *
unblockOne(StgBlockingQueueElement *bqe, StgClosure *node)
{
debugBelch("## BQ Stats of %p: [%d entries] %s\n",
node, len, (bqe!=END_BQ_QUEUE) ? "RBH" : ""));
}
-#elif defined(PAR)
+#elif defined(PARALLEL_HASKELL)
void
awakenBlockedQueue(StgBlockingQueueElement *q, StgClosure *node)
{
RELEASE_LOCK(&sched_mutex);
}
-#else /* !GRAN && !PAR */
+#else /* !GRAN && !PARALLEL_HASKELL */
void
awakenBlockedQueueNoLock(StgTSO *tso)
{
+ if (tso == NULL) return; // hack; see bug #1235728, and comments in
+ // Exception.cmm
while (tso != END_TSO_QUEUE) {
tso = unblockOneLocked(tso);
}
void
awakenBlockedQueue(StgTSO *tso)
{
+ if (tso == NULL) return; // hack; see bug #1235728, and comments in
+ // Exception.cmm
ACQUIRE_LOCK(&sched_mutex);
while (tso != END_TSO_QUEUE) {
tso = unblockOneLocked(tso);
{
interrupted = 1;
context_switch = 1;
-#ifdef RTS_SUPPORTS_THREADS
- wakeBlockedWorkerThread();
-#endif
+ threadRunnable();
+ /* ToDo: if invoked from a signal handler, this threadRunnable
+ * only works if there's another thread (not this one) waiting to
+ * be woken up.
+ */
}
/* -----------------------------------------------------------------------------
This has nothing to do with the UnblockThread event in GranSim. -- HWL
-------------------------------------------------------------------------- */
-#if defined(GRAN) || defined(PAR)
+#if defined(GRAN) || defined(PARALLEL_HASKELL)
/*
NB: only the type of the blocking queue is different in GranSim and GUM
the operations on the queue-elements are the same
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);
{
case BlockedOnRead:
case BlockedOnWrite:
-#if defined(mingw32_TARGET_OS)
+#if defined(mingw32_HOST_OS)
case BlockedOnDoProc:
#endif
{
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;
}
}
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);
{
}
case BlockedOnBlackHole:
- ASSERT(get_itbl(tso->block_info.closure)->type == BLACKHOLE_BQ);
{
- StgBlockingQueue *bq = (StgBlockingQueue *)(tso->block_info.closure);
-
- last = &bq->blocking_queue;
- for (t = bq->blocking_queue; t != END_TSO_QUEUE;
+ last = &blackhole_queue;
+ for (t = blackhole_queue; t != END_TSO_QUEUE;
last = &t->link, t = t->link) {
if (t == tso) {
*last = tso->link;
case BlockedOnRead:
case BlockedOnWrite:
-#if defined(mingw32_TARGET_OS)
+#if defined(mingw32_HOST_OS)
case BlockedOnDoProc:
#endif
{
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;
}
}
#endif
/* -----------------------------------------------------------------------------
+ * checkBlackHoles()
+ *
+ * Check the blackhole_queue for threads that can be woken up. We do
+ * this periodically: before every GC, and whenever the run queue is
+ * empty.
+ *
+ * An elegant solution might be to just wake up all the blocked
+ * threads with awakenBlockedQueue occasionally: they'll go back to
+ * sleep again if the object is still a BLACKHOLE. Unfortunately this
+ * doesn't give us a way to tell whether we've actually managed to
+ * wake up any threads, so we would be busy-waiting.
+ *
+ * -------------------------------------------------------------------------- */
+
+static rtsBool
+checkBlackHoles( void )
+{
+ StgTSO **prev, *t;
+ rtsBool any_woke_up = rtsFalse;
+ StgHalfWord type;
+
+ IF_DEBUG(scheduler, sched_belch("checking threads blocked on black holes"));
+
+ // ASSUMES: sched_mutex
+ prev = &blackhole_queue;
+ t = blackhole_queue;
+ while (t != END_TSO_QUEUE) {
+ ASSERT(t->why_blocked == BlockedOnBlackHole);
+ type = get_itbl(t->block_info.closure)->type;
+ if (type != BLACKHOLE && type != CAF_BLACKHOLE) {
+ IF_DEBUG(sanity,checkTSO(t));
+ t = unblockOneLocked(t);
+ *prev = t;
+ any_woke_up = rtsTrue;
+ } else {
+ prev = &t->link;
+ t = t->link;
+ }
+ }
+
+ return any_woke_up;
+}
+
+/* -----------------------------------------------------------------------------
* raiseAsync()
*
* The following function implements the magic for raising an
void
deleteThread(StgTSO *tso)
{
- raiseAsync(tso,NULL);
+ if (tso->why_blocked != BlockedOnCCall &&
+ tso->why_blocked != BlockedOnCCall_NoUnblockExc) {
+ raiseAsync(tso,NULL);
+ }
}
#ifdef FORKPROCESS_PRIMOP_SUPPORTED
void
raiseAsync(StgTSO *tso, StgClosure *exception)
{
+ raiseAsync_(tso, exception, rtsFalse);
+}
+
+static void
+raiseAsync_(StgTSO *tso, StgClosure *exception, rtsBool stop_at_atomically)
+{
StgRetInfoTable *info;
StgPtr sp;
// 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
+
StgPtr frame;
while (info->i.type != UPDATE_FRAME
&& (info->i.type != CATCH_FRAME || exception == NULL)
- && info->i.type != STOP_FRAME) {
+ && info->i.type != STOP_FRAME
+ && (info->i.type != ATOMICALLY_FRAME || stop_at_atomically == rtsFalse))
+ {
+ if (info->i.type == CATCH_RETRY_FRAME || info->i.type == ATOMICALLY_FRAME) {
+ // IF we find an ATOMICALLY_FRAME then we abort the
+ // current transaction and propagate the exception. In
+ // this case (unlike ordinary exceptions) we do not care
+ // whether the transaction is valid or not because its
+ // possible validity cannot have caused the exception
+ // and will not be visible after the abort.
+ IF_DEBUG(stm,
+ debugBelch("Found atomically block delivering async exception\n"));
+ stmAbortTransaction(tso -> trec);
+ tso -> trec = stmGetEnclosingTRec(tso -> trec);
+ }
frame += stack_frame_sizeW((StgClosure *)frame);
info = get_ret_itbl((StgClosure *)frame);
}
switch (info->i.type) {
+ case ATOMICALLY_FRAME:
+ ASSERT(stop_at_atomically);
+ ASSERT(stmGetEnclosingTRec(tso->trec) == NO_TREC);
+ stmCondemnTransaction(tso -> trec);
+#ifdef REG_R1
+ tso->sp = frame;
+#else
+ // R1 is not a register: the return convention for IO in
+ // this case puts the return value on the stack, so we
+ // need to set up the stack to return to the atomically
+ // frame properly...
+ tso->sp = frame - 2;
+ tso->sp[1] = (StgWord) &stg_NO_FINALIZER_closure; // why not?
+ tso->sp[0] = (StgWord) &stg_ut_1_0_unreg_info;
+#endif
+ tso->what_next = ThreadRunGHC;
+ return;
+
case CATCH_FRAME:
// If we find a CATCH_FRAME, and we've got an exception to raise,
// then build the THUNK raise(exception), and leave it on
#ifdef PROFILING
StgCatchFrame *cf = (StgCatchFrame *)frame;
#endif
- StgClosure *raise;
+ StgThunk *raise;
// we've got an exception to raise, so let's pass it to the
// handler in this frame.
//
- raise = (StgClosure *)allocate(sizeofW(StgClosure)+1);
+ raise = (StgThunk *)allocate(sizeofW(StgThunk)+MIN_UPD_SIZE);
TICK_ALLOC_SE_THK(1,0);
SET_HDR(raise,&stg_raise_info,cf->header.prof.ccs);
raise->payload[0] = exception;
// fun field.
//
words = frame - sp - 1;
- ap = (StgAP_STACK *)allocate(PAP_sizeW(words));
+ ap = (StgAP_STACK *)allocate(AP_STACK_sizeW(words));
ap->size = words;
ap->fun = (StgClosure *)sp[0];
StgWord
raiseExceptionHelper (StgTSO *tso, StgClosure *exception)
{
- StgClosure *raise_closure = NULL;
+ StgThunk *raise_closure = NULL;
StgPtr p, next;
StgRetInfoTable *info;
//
// Only create raise_closure if we need to.
if (raise_closure == NULL) {
raise_closure =
- (StgClosure *)allocate(sizeofW(StgClosure)+MIN_UPD_SIZE);
+ (StgThunk *)allocate(sizeofW(StgThunk)+MIN_UPD_SIZE);
SET_HDR(raise_closure, &stg_raise_info, CCCS);
raise_closure->payload[0] = exception;
}
- UPD_IND(((StgUpdateFrame *)p)->updatee,raise_closure);
+ UPD_IND(((StgUpdateFrame *)p)->updatee,(StgClosure *)raise_closure);
p = next;
continue;
+
+ case ATOMICALLY_FRAME:
+ IF_DEBUG(stm, debugBelch("Found ATOMICALLY_FRAME at %p\n", p));
+ tso->sp = p;
+ return ATOMICALLY_FRAME;
case CATCH_FRAME:
tso->sp = p;
return CATCH_FRAME;
+
+ case CATCH_STM_FRAME:
+ IF_DEBUG(stm, debugBelch("Found CATCH_STM_FRAME at %p\n", p));
+ tso->sp = p;
+ return CATCH_STM_FRAME;
case STOP_FRAME:
tso->sp = p;
return STOP_FRAME;
+ case CATCH_RETRY_FRAME:
default:
p = next;
continue;
}
}
+
+/* -----------------------------------------------------------------------------
+ findRetryFrameHelper
+
+ This function is called by the retry# primitive. It traverses the stack
+ leaving tso->sp referring to the frame which should handle the retry.
+
+ 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 should not expect to see CATCH_FRAME or STOP_FRAME because those should
+ not be created within memory transactions.
+ -------------------------------------------------------------------------- */
+
+StgWord
+findRetryFrameHelper (StgTSO *tso)
+{
+ StgPtr p, next;
+ StgRetInfoTable *info;
+
+ p = tso -> sp;
+ while (1) {
+ info = get_ret_itbl((StgClosure *)p);
+ next = p + stack_frame_sizeW((StgClosure *)p);
+ switch (info->i.type) {
+
+ case ATOMICALLY_FRAME:
+ IF_DEBUG(stm, debugBelch("Found ATOMICALLY_FRAME at %p during retrry\n", p));
+ tso->sp = p;
+ return ATOMICALLY_FRAME;
+
+ case CATCH_RETRY_FRAME:
+ IF_DEBUG(stm, debugBelch("Found CATCH_RETRY_FRAME at %p during retrry\n", p));
+ tso->sp = p;
+ return CATCH_RETRY_FRAME;
+
+ case CATCH_STM_FRAME:
+ default:
+ ASSERT(info->i.type != CATCH_FRAME);
+ ASSERT(info->i.type != STOP_FRAME);
+ p = next;
+ continue;
+ }
+ }
+}
+
/* -----------------------------------------------------------------------------
resurrectThreads is called after garbage collection on the list of
threads found to be garbage. Each of these threads will be woken
case BlockedOnBlackHole:
raiseAsync(tso,(StgClosure *)NonTermination_closure);
break;
+ case BlockedOnSTM:
+ raiseAsync(tso,(StgClosure *)BlockedIndefinitely_closure);
+ break;
case NotBlocked:
/* This might happen if the thread was blocked on a black hole
* belonging to a thread that we've just woken up (raiseAsync
}
}
-/* -----------------------------------------------------------------------------
- * Blackhole detection: if we reach a deadlock, test whether any
- * threads are blocked on themselves. Any threads which are found to
- * be self-blocked get sent a NonTermination exception.
- *
- * This is only done in a deadlock situation in order to avoid
- * performance overhead in the normal case.
- *
- * Locks: sched_mutex is held upon entry and exit.
- * -------------------------------------------------------------------------- */
-
-static void
-detectBlackHoles( void )
-{
- StgTSO *tso = all_threads;
- StgPtr frame;
- StgClosure *blocked_on;
- StgRetInfoTable *info;
-
- for (tso = all_threads; tso != END_TSO_QUEUE; tso = tso->global_link) {
-
- while (tso->what_next == ThreadRelocated) {
- tso = tso->link;
- ASSERT(get_itbl(tso)->type == TSO);
- }
-
- if (tso->why_blocked != BlockedOnBlackHole) {
- continue;
- }
- blocked_on = tso->block_info.closure;
-
- frame = tso->sp;
-
- while(1) {
- info = get_ret_itbl((StgClosure *)frame);
- switch (info->i.type) {
- case UPDATE_FRAME:
- if (((StgUpdateFrame *)frame)->updatee == blocked_on) {
- /* We are blocking on one of our own computations, so
- * send this thread the NonTermination exception.
- */
- IF_DEBUG(scheduler,
- sched_belch("thread %d is blocked on itself", tso->id));
- raiseAsync(tso, (StgClosure *)NonTermination_closure);
- goto done;
- }
-
- frame = (StgPtr)((StgUpdateFrame *)frame + 1);
- continue;
-
- case STOP_FRAME:
- goto done;
-
- // normal stack frames; do nothing except advance the pointer
- default:
- frame += stack_frame_sizeW((StgClosure *)frame);
- }
- }
- done: ;
- }
-}
-
/* ----------------------------------------------------------------------------
* 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]
------------------------------------------------------------------------- */
-static
-void
+static void
printThreadBlockage(StgTSO *tso)
{
switch (tso->why_blocked) {
case BlockedOnRead:
- debugBelch("is blocked on read from fd %d", tso->block_info.fd);
+ debugBelch("is blocked on read from fd %d", (int)(tso->block_info.fd));
break;
case BlockedOnWrite:
- debugBelch("is blocked on write to fd %d", tso->block_info.fd);
+ debugBelch("is blocked on write to fd %d", (int)(tso->block_info.fd));
break;
-#if defined(mingw32_TARGET_OS)
+#if defined(mingw32_HOST_OS)
case BlockedOnDoProc:
- debugBelch("is blocked on proc (request: %d)", tso->block_info.async_result->reqID);
+ debugBelch("is blocked on proc (request: %ld)", tso->block_info.async_result->reqID);
break;
#endif
case BlockedOnDelay:
- debugBelch("is blocked until %d", tso->block_info.target);
+ debugBelch("is blocked until %ld", (long)(tso->block_info.target));
break;
case BlockedOnMVar:
- debugBelch("is blocked on an MVar");
+ debugBelch("is blocked on an MVar @ %p", tso->block_info.closure);
break;
case BlockedOnException:
debugBelch("is blocked on delivering an exception to thread %d",
case NotBlocked:
debugBelch("is not blocked");
break;
-#if defined(PAR)
+#if defined(PARALLEL_HASKELL)
case BlockedOnGA:
debugBelch("is blocked on global address; local FM_BQ is %p (%s)",
tso->block_info.closure, info_type(tso->block_info.closure));
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);
}
}
-static
-void
+static void
printThreadStatus(StgTSO *tso)
{
switch (tso->what_next) {
printAllThreads(void)
{
StgTSO *t;
- void *label;
# if defined(GRAN)
char time_string[TIME_STR_LEN], node_str[NODE_STR_LEN];
time_string, rtsFalse/*no commas!*/);
debugBelch("all threads at [%s]:\n", time_string);
-# elif defined(PAR)
+# elif defined(PARALLEL_HASKELL)
char time_string[TIME_STR_LEN], node_str[NODE_STR_LEN];
ullong_format_string(CURRENT_TIME,
time_string, rtsFalse/*no commas!*/);
debugBelch("all threads:\n");
# endif
- for (t = all_threads; t != END_TSO_QUEUE; t = t->global_link) {
- debugBelch("\tthread %d @ %p ", t->id, (void *)t);
- label = lookupThreadLabel(t->id);
- if (label) debugBelch("[\"%s\"] ",(char *)label);
- printThreadStatus(t);
- debugBelch("\n");
+ for (t = all_threads; t != END_TSO_QUEUE; ) {
+ debugBelch("\tthread %4d @ %p ", t->id, (void *)t);
+#if defined(DEBUG)
+ {
+ void *label = lookupThreadLabel(t->id);
+ if (label) debugBelch("[\"%s\"] ",(char *)label);
+ }
+#endif
+ if (t->what_next == ThreadRelocated) {
+ debugBelch("has been relocated...\n");
+ t = t->link;
+ } else {
+ printThreadStatus(t);
+ debugBelch("\n");
+ t = t->global_link;
+ }
}
}
-
+
#ifdef DEBUG
+// useful from gdb
+void
+printThreadQueue(StgTSO *t)
+{
+ nat i = 0;
+ for (; t != END_TSO_QUEUE; t = t->link) {
+ debugBelch("\tthread %d @ %p ", t->id, (void *)t);
+ if (t->what_next == ThreadRelocated) {
+ debugBelch("has been relocated...\n");
+ } else {
+ printThreadStatus(t);
+ debugBelch("\n");
+ }
+ i++;
+ }
+ debugBelch("%d threads on queue\n", i);
+}
+
/*
Print a whole blocking queue attached to node (debugging only).
*/
-# if defined(PAR)
+# if defined(PARALLEL_HASKELL)
void
print_bq (StgClosure *node)
{
} /* for */
debugBelch("\n");
}
-#else
-/*
- Nice and easy: only TSOs on the blocking queue
-*/
-void
-print_bq (StgClosure *node)
-{
- StgTSO *tso;
-
- ASSERT(node!=(StgClosure*)NULL); // sanity check
- for (tso = ((StgBlockingQueue*)node)->blocking_queue;
- tso != END_TSO_QUEUE;
- tso=tso->link) {
- ASSERT(tso!=NULL && tso!=END_TSO_QUEUE); // sanity check
- ASSERT(get_itbl(tso)->type == TSO); // guess what, sanity check
- debugBelch(" TSO %d (%p),", tso->id, tso);
- }
- debugBelch("\n");
-}
# endif
-#if defined(PAR)
+#if defined(PARALLEL_HASKELL)
static nat
run_queue_len(void)
{
va_start(ap,s);
#ifdef RTS_SUPPORTS_THREADS
debugBelch("sched (task %p): ", osThreadId());
-#elif defined(PAR)
+#elif defined(PARALLEL_HASKELL)
debugBelch("== ");
#else
debugBelch("sched: ");
projects / ghc-hetmet.git / blobdiff