/* -----------------------------------------------------------------------------
*
- * (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
*/
#elif defined(PAR)
void awakenBlockedQueue(StgBlockingQueueElement *q, StgClosure *node);
#else
-void awakenBlockedQueue (StgTSO *tso);
-void awakenBlockedQueueNoLock (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()
*
* 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);
-/* raiseExceptionHelper */
-StgWord raiseExceptionHelper (StgTSO *tso, StgClosure *exception);
-
-/* awaitEvent(rtsBool wait)
- *
- * Checks for blocked threads that need to be woken.
+/* 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 */
-
-/* wakeBlockedWorkerThread()
- *
- * If a worker thread is currently blocked in awaitEvent(), interrupt it.
- *
- * Called from STG : NO
- * Locks assumed : sched_mutex
- */
-void wakeBlockedWorkerThread(void); /* In Select.c */
+/* raiseExceptionHelper */
+StgWord raiseExceptionHelper (StgRegTable *reg, StgTSO *tso, StgClosure *exception);
-/* resetWorkerWakeupPipeAfterFork()
- *
- * Notify Select.c that a fork() has occured
- *
- * Called from STG : NO
- * Locks assumed : don't care, but must be called right after fork()
- */
-void resetWorkerWakeupPipeAfterFork(void); /* In Select.c */
+/* findRetryFrameHelper */
+StgWord findRetryFrameHelper (StgTSO *tso);
/* GetRoots(evac_fn f)
*
*/
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);
#endif
/* Context switch flag.
- * Locks required : sched_mutex
+ * Locks required : none (conflicts are harmless)
+ */
+extern int RTS_VAR(context_switch);
+
+/* Interrupted flag.
+ * Locks required : none (makes one transition from false->true)
*/
-extern nat RTS_VAR(context_switch);
extern rtsBool RTS_VAR(interrupted);
-/* In Select.c */
-extern nat RTS_VAR(timestamp);
+/* Shutdown flag.
+ * Locks required : none (makes one transition from false->true)
+ */
+extern rtsBool shutting_down_scheduler;
+
+/*
+ * 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
#if defined(GRAN)
// run_queue_hds defined in GranSim.h
#else
-extern StgTSO *RTS_VAR(run_queue_hd), *RTS_VAR(run_queue_tl);
+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. */
+#endif
+
+/* Linked list of all threads.
+ * Locks required : sched_mutex
+ */
extern StgTSO *RTS_VAR(all_threads);
-#if defined(RTS_SUPPORTS_THREADS)
-/* Schedule.c has detailed info on what these do */
-extern Mutex RTS_VAR(sched_mutex);
-extern Condition RTS_VAR(returning_worker_cond);
-extern nat RTS_VAR(rts_n_waiting_workers);
-extern nat RTS_VAR(rts_n_waiting_tasks);
+/* 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
-StgBool rtsSupportsBoundThreads(void);
StgBool isThreadBound(StgTSO *tso);
-extern SchedulerStatus rts_mainLazyIO(HaskellObj p, /*out*/HaskellObj *ret);
-
+SchedulerStatus rts_mainLazyIO(HaskellObj p, /*out*/HaskellObj *ret);
/* Called by shutdown_handler(). */
-void interruptStgRts ( void );
-
-void raiseAsync(StgTSO *tso, StgClosure *exception);
-nat run_queue_len(void);
+void interruptStgRts (void);
-void resurrectThreads( StgTSO * );
-
-/* Main threads:
- *
- * These are the threads which clients have requested that we run.
- *
- * In a 'threaded' build, each of these corresponds to one bound thread.
- * The pointer to the StgMainThread is passed as a parameter to schedule;
- * this invocation of schedule will always pass this main thread's
- * bound_thread_cond to waitForkWorkCapability; OS-thread-switching
- * takes place using passCapability.
- *
- * In non-threaded builds, 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)
-#if defined(THREADED_RTS)
- Condition bound_thread_cond;
-#else
- Condition wakeup;
-#endif
-#endif
- struct StgMainThread_ *prev;
- 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
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(pt) \
- do { StgTSO *__tmp_t = run_queue_hd; \
- if (__tmp_t != END_TSO_QUEUE) { \
- run_queue_hd = __tmp_t->link; \
- __tmp_t->link = END_TSO_QUEUE; \
- if (run_queue_hd == END_TSO_QUEUE) { \
- run_queue_tl = END_TSO_QUEUE; \
- } \
- } \
- pt = __tmp_t; \
- } while(0)
+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() \
- wakeBlockedWorkerThread(); \
- context_switch = 1;
-#else
-#define THREAD_RUNNABLE() /* nothing */
+}
#endif
/* Check whether various thread queues are empty
*/
-#define EMPTY_QUEUE(q) (q == END_TSO_QUEUE)
-
-#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))
-
-#define EMPTY_THREAD_QUEUES() (EMPTY_RUN_QUEUE() && \
- EMPTY_BLOCKED_QUEUE() && \
- EMPTY_SLEEPING_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
-#if defined(RTS_SUPPORTS_THREADS)
-/* If no task is waiting for a capability,
- * and if there is work to be done
- * or if we need to wait for IO or delay requests,
- * spawn a new worker thread.
- */
-void
-startSchedulerTaskIfNecessary(void);
+STATIC_INLINE rtsBool
+emptyThreadQueues(Capability *cap)
+{
+ return emptyRunQueue(cap)
+#if !defined(THREADED_RTS)
+ && EMPTY_BLOCKED_QUEUE() && EMPTY_SLEEPING_QUEUE()
#endif
+ ;
+}
+
+STATIC_INLINE void
+dirtyTSO (StgTSO *tso)
+{
+ tso->flags |= TSO_DIRTY;
+}
#ifdef DEBUG
-extern void sched_belch(char *s, ...)
+void sched_belch(char *s, ...)
GNU_ATTRIBUTE(format (printf, 1, 2));
#endif
-#endif /* __SCHEDULE_H__ */
+#endif /* !IN_STG_CODE */
+
+#endif /* SCHEDULE_H */
+
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