X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=ghc%2Frts%2FSchedule.h;h=63dfeb7dd51f89c82788f7f639acb426efbf8366;hb=5638488ba28ec84fbf64bf2742a040e3fa30bed4;hp=7722802cbddcd302699d9777751f727576db3632;hpb=d9d8ab1594dd83d25708dc0d20dfd8e068f1c2e3;p=ghc-hetmet.git diff --git a/ghc/rts/Schedule.h b/ghc/rts/Schedule.h index 7722802..63dfeb7 100644 --- a/ghc/rts/Schedule.h +++ b/ghc/rts/Schedule.h @@ -1,30 +1,32 @@ /* ----------------------------------------------------------------------------- - * $Id: Schedule.h,v 1.35 2002/07/25 18:37:00 sof Exp $ * - * (c) The GHC Team 1998-1999 + * (c) The GHC Team 1998-2005 * * Prototypes for functions in Schedule.c * (RTS internal scheduler interface) * * -------------------------------------------------------------------------*/ -#ifndef __SCHEDULE_H__ -#define __SCHEDULE_H__ +#ifndef SCHEDULE_H +#define SCHEDULE_H + #include "OSThreads.h" +#include "Capability.h" -/* initScheduler(), exitScheduler(), startTasks() - * +/* initScheduler(), exitScheduler() * Called from STG : no * Locks assumed : none */ -extern void initScheduler ( void ); -extern void exitScheduler ( void ); +void initScheduler (void); +void exitScheduler (void); + +// Place a new thread on the run queue of the specified Capability +void scheduleThread (Capability *cap, StgTSO *tso); /* awakenBlockedQueue() * * Takes a pointer to the beginning of a blocked TSO queue, and * wakes up the entire queue. - * * Called from STG : yes * Locks assumed : none */ @@ -33,22 +35,16 @@ void awakenBlockedQueue(StgBlockingQueueElement *q, StgClosure *node); #elif defined(PAR) void awakenBlockedQueue(StgBlockingQueueElement *q, StgClosure *node); #else -void awakenBlockedQueue(StgTSO *tso); +void awakenBlockedQueue (Capability *cap, StgTSO *tso); #endif /* unblockOne() * - * Takes a pointer to the beginning of a blocked TSO queue, and - * removes the first thread, placing it on the runnable queue. - * - * Called from STG : yes - * Locks assumed : none + * Put the specified thread on the run queue of the given Capability. + * Called from STG : yes + * Locks assumed : we own the Capability. */ -#if defined(GRAN) || defined(PAR) -StgBlockingQueueElement *unblockOne(StgBlockingQueueElement *bqe, StgClosure *node); -#else -StgTSO *unblockOne(StgTSO *tso); -#endif +StgTSO * unblockOne(Capability *cap, StgTSO *tso); /* raiseAsync() * @@ -57,26 +53,21 @@ StgTSO *unblockOne(StgTSO *tso); * Called from STG : yes * Locks assumed : none */ -void raiseAsync(StgTSO *tso, StgClosure *exception); -void raiseAsyncWithLock(StgTSO *tso, StgClosure *exception); +void raiseAsync(Capability *cap, StgTSO *tso, StgClosure *exception); -/* awaitEvent() - * - * Raises an exception asynchronously in the specified thread. +/* suspendComputation() * - * Called from STG : NO - * Locks assumed : sched_mutex + * A variant of raiseAsync(), this strips the stack of the specified + * thread down to the stop_here point, leaving a current closure on + * top of the stack at [stop_here - 1]. */ -void awaitEvent(rtsBool wait); /* In Select.c */ +void suspendComputation(Capability *cap, StgTSO *tso, StgPtr stop_here); -/* wakeUpSleepingThreads(nat ticks) - * - * Wakes up any sleeping threads whose timers have expired. - * - * Called from STG : NO - * Locks assumed : sched_mutex - */ -rtsBool wakeUpSleepingThreads(nat); /* In Select.c */ +/* raiseExceptionHelper */ +StgWord raiseExceptionHelper (StgRegTable *reg, StgTSO *tso, StgClosure *exception); + +/* findRetryFrameHelper */ +StgWord findRetryFrameHelper (StgTSO *tso); /* GetRoots(evac_fn f) * @@ -87,7 +78,14 @@ rtsBool wakeUpSleepingThreads(nat); /* In Select.c */ */ void GetRoots(evac_fn); -// ToDo: check whether all fcts below are used in the SMP version, too +/* workerStart() + * + * Entry point for a new worker task. + * Called from STG : NO + * Locks assumed : none + */ +void workerStart(Task *task); + #if defined(GRAN) void awaken_blocked_queue(StgBlockingQueueElement *q, StgClosure *node); void unlink_from_bq(StgTSO* tso, StgClosure* node); @@ -104,13 +102,36 @@ void initThread(StgTSO *tso, nat stack_size); #endif /* Context switch flag. - * Locks required : sched_mutex + * Locks required : none (conflicts are harmless) */ -extern nat context_switch; -extern rtsBool interrupted; +extern int RTS_VAR(context_switch); -/* In Select.c */ -extern nat timestamp; +/* The state of the scheduler. This is used to control the sequence + * of events during shutdown, and when the runtime is interrupted + * using ^C. + */ +#define SCHED_RUNNING 0 /* running as normal */ +#define SCHED_INTERRUPTING 1 /* ^C detected, before threads are deleted */ +#define SCHED_INTERRUPTED 2 /* ^C detected, after threads deleted */ +#define SCHED_SHUTTING_DOWN 3 /* final shutdown */ + +extern rtsBool RTS_VAR(sched_state); + +/* + * flag that tracks whether we have done any execution in this time slice. + */ +#define ACTIVITY_YES 0 /* there has been activity in the current slice */ +#define ACTIVITY_MAYBE_NO 1 /* no activity in the current slice */ +#define ACTIVITY_INACTIVE 2 /* a complete slice has passed with no activity */ +#define ACTIVITY_DONE_GC 3 /* like 2, but we've done a GC too */ + +/* Recent activity flag. + * Locks required : Transition from MAYBE_NO to INACTIVE + * happens in the timer signal, so it is atomic. Trnasition from + * INACTIVE to DONE_GC happens under sched_mutex. No lock required + * to set it to ACTIVITY_YES. + */ +extern nat recent_activity; /* Thread queues. * Locks required : sched_mutex @@ -120,74 +141,44 @@ extern nat timestamp; #if defined(GRAN) // run_queue_hds defined in GranSim.h #else -extern StgTSO *run_queue_hd, *run_queue_tl; -extern StgTSO *blocked_queue_hd, *blocked_queue_tl; -extern StgTSO *sleeping_queue; +extern StgTSO *RTS_VAR(blackhole_queue); +#if !defined(THREADED_RTS) +extern StgTSO *RTS_VAR(blocked_queue_hd), *RTS_VAR(blocked_queue_tl); +extern StgTSO *RTS_VAR(sleeping_queue); #endif -/* Linked list of all threads. */ -extern StgTSO *all_threads; - -#if defined(RTS_SUPPORTS_THREADS) -/* Schedule.c has detailed info on what these do */ -extern Mutex sched_mutex; -extern Condition thread_ready_cond; -extern Condition returning_worker_cond; -extern nat rts_n_waiting_workers; -extern nat rts_n_waiting_tasks; #endif -StgInt forkProcess(StgTSO *tso); - -extern SchedulerStatus rts_mainEvalIO(HaskellObj p, /*out*/HaskellObj *ret); +/* Linked list of all threads. + * Locks required : sched_mutex + */ +extern StgTSO *RTS_VAR(all_threads); + +/* Set to rtsTrue if there are threads on the blackhole_queue, and + * it is possible that one or more of them may be available to run. + * This flag is set to rtsFalse after we've checked the queue, and + * set to rtsTrue just before we run some Haskell code. It is used + * to decide whether we should yield the Capability or not. + * Locks required : none (see scheduleCheckBlackHoles()). + */ +extern rtsBool blackholes_need_checking; +#if defined(THREADED_RTS) +extern Mutex RTS_VAR(sched_mutex); +#endif -/* Called by shutdown_handler(). */ -void interruptStgRts ( void ); +StgBool isThreadBound(StgTSO *tso); -void raiseAsync(StgTSO *tso, StgClosure *exception); -nat run_queue_len(void); +SchedulerStatus rts_mainLazyIO(HaskellObj p, /*out*/HaskellObj *ret); -void resurrectThreads( StgTSO * ); +/* Called by shutdown_handler(). */ +void interruptStgRts (void); -/* Main threads: - * - * These are the threads which clients have requested that we run. - * - * In a 'threaded' build, we might have several concurrent clients all - * waiting for results, and each one will wait on a condition variable - * until the result is available. - * - * In non-SMP, clients are strictly nested: the first client calls - * into the RTS, which might call out again to C with a _ccall_GC, and - * eventually re-enter the RTS. - * - * This is non-abstract at the moment because the garbage collector - * treats pointers to TSOs from the main thread list as "weak" - these - * pointers won't prevent a thread from receiving a BlockedOnDeadMVar - * exception. - * - * Main threads information is kept in a linked list: - */ -typedef struct StgMainThread_ { - StgTSO * tso; - SchedulerStatus stat; - StgClosure ** ret; -#if defined(RTS_SUPPORTS_THREADS) - Condition wakeup; -#endif - struct StgMainThread_ *link; -} StgMainThread; +nat run_queue_len (void); -/* Main thread queue. - * Locks required: sched_mutex. - */ -extern StgMainThread *main_threads; +void resurrectThreads (StgTSO *); void printAllThreads(void); -#ifdef COMPILING_SCHEDULER -static void printThreadBlockage(StgTSO *tso); -static void printThreadStatus(StgTSO *tso); -#endif + /* debugging only */ #ifdef DEBUG @@ -197,82 +188,118 @@ void print_bq (StgClosure *node); void print_bqe (StgBlockingQueueElement *bqe); #endif +void labelThread(StgPtr tso, char *label); + /* ----------------------------------------------------------------------------- - * Some convenient macros... + * Some convenient macros/inline functions... */ +#if !IN_STG_CODE + /* END_TSO_QUEUE and friends now defined in includes/StgMiscClosures.h */ /* Add a thread to the end of the run queue. * NOTE: tso->link should be END_TSO_QUEUE before calling this macro. + * ASSUMES: cap->running_task is the current task. */ -#define APPEND_TO_RUN_QUEUE(tso) \ - ASSERT(tso->link == END_TSO_QUEUE); \ - if (run_queue_hd == END_TSO_QUEUE) { \ - run_queue_hd = tso; \ - } else { \ - run_queue_tl->link = tso; \ - } \ - run_queue_tl = tso; +STATIC_INLINE void +appendToRunQueue (Capability *cap, StgTSO *tso) +{ + ASSERT(tso->link == END_TSO_QUEUE); + if (cap->run_queue_hd == END_TSO_QUEUE) { + cap->run_queue_hd = tso; + } else { + cap->run_queue_tl->link = tso; + } + cap->run_queue_tl = tso; +} /* Push a thread on the beginning of the run queue. Used for * newly awakened threads, so they get run as soon as possible. + * ASSUMES: cap->running_task is the current task. */ -#define PUSH_ON_RUN_QUEUE(tso) \ - tso->link = run_queue_hd; \ - run_queue_hd = tso; \ - if (run_queue_tl == END_TSO_QUEUE) { \ - run_queue_tl = tso; \ +STATIC_INLINE void +pushOnRunQueue (Capability *cap, StgTSO *tso) +{ + tso->link = cap->run_queue_hd; + cap->run_queue_hd = tso; + if (cap->run_queue_tl == END_TSO_QUEUE) { + cap->run_queue_tl = tso; } +} /* Pop the first thread off the runnable queue. */ -#define POP_RUN_QUEUE() \ - ({ StgTSO *t = run_queue_hd; \ - if (t != END_TSO_QUEUE) { \ - run_queue_hd = t->link; \ - t->link = END_TSO_QUEUE; \ - if (run_queue_hd == END_TSO_QUEUE) { \ - run_queue_tl = END_TSO_QUEUE; \ - } \ - } \ - t; \ - }) +STATIC_INLINE StgTSO * +popRunQueue (Capability *cap) +{ + StgTSO *t = cap->run_queue_hd; + ASSERT(t != END_TSO_QUEUE); + cap->run_queue_hd = t->link; + t->link = END_TSO_QUEUE; + if (cap->run_queue_hd == END_TSO_QUEUE) { + cap->run_queue_tl = END_TSO_QUEUE; + } + return t; +} /* Add a thread to the end of the blocked queue. */ -#define APPEND_TO_BLOCKED_QUEUE(tso) \ - ASSERT(tso->link == END_TSO_QUEUE); \ - if (blocked_queue_hd == END_TSO_QUEUE) { \ - blocked_queue_hd = tso; \ - } else { \ - blocked_queue_tl->link = tso; \ - } \ +#if !defined(THREADED_RTS) +STATIC_INLINE void +appendToBlockedQueue(StgTSO *tso) +{ + ASSERT(tso->link == END_TSO_QUEUE); + if (blocked_queue_hd == END_TSO_QUEUE) { + blocked_queue_hd = tso; + } else { + blocked_queue_tl->link = tso; + } blocked_queue_tl = tso; - -/* Signal that a runnable thread has become available, in - * case there are any waiting tasks to execute it. - */ -#if defined(RTS_SUPPORTS_THREADS) -#define THREAD_RUNNABLE() \ - if ( !noCapabilities() ) { \ - signalCondition(&thread_ready_cond); \ - } \ - context_switch = 1; -#else -#define THREAD_RUNNABLE() /* nothing */ +} #endif /* Check whether various thread queues are empty */ -#define EMPTY_QUEUE(q) (q == END_TSO_QUEUE) +STATIC_INLINE rtsBool +emptyQueue (StgTSO *q) +{ + return (q == END_TSO_QUEUE); +} + +STATIC_INLINE rtsBool +emptyRunQueue(Capability *cap) +{ + return emptyQueue(cap->run_queue_hd); +} + +#if !defined(THREADED_RTS) +#define EMPTY_BLOCKED_QUEUE() (emptyQueue(blocked_queue_hd)) +#define EMPTY_SLEEPING_QUEUE() (emptyQueue(sleeping_queue)) +#endif + +STATIC_INLINE rtsBool +emptyThreadQueues(Capability *cap) +{ + return emptyRunQueue(cap) +#if !defined(THREADED_RTS) + && EMPTY_BLOCKED_QUEUE() && EMPTY_SLEEPING_QUEUE() +#endif + ; +} + +#ifdef DEBUG +void sched_belch(char *s, ...) + GNU_ATTRIBUTE(format (printf, 1, 2)); +#endif + +#endif /* !IN_STG_CODE */ -#define EMPTY_RUN_QUEUE() (EMPTY_QUEUE(run_queue_hd)) -#define EMPTY_BLOCKED_QUEUE() (EMPTY_QUEUE(blocked_queue_hd)) -#define EMPTY_SLEEPING_QUEUE() (EMPTY_QUEUE(sleeping_queue)) +STATIC_INLINE void +dirtyTSO (StgTSO *tso) +{ + tso->flags |= TSO_DIRTY; +} -#define EMPTY_THREAD_QUEUES() (EMPTY_RUN_QUEUE() && \ - EMPTY_BLOCKED_QUEUE() && \ - EMPTY_SLEEPING_QUEUE()) +#endif /* SCHEDULE_H */ -#endif /* __SCHEDULE_H__ */