/* -----------------------------------------------------------------------------
- * $Id: Schedule.h,v 1.5 1999/03/16 13:20:17 simonm Exp $
*
* (c) The GHC Team 1998-1999
*
* Prototypes for functions in Schedule.c
* (RTS internal scheduler interface)
*
- * ---------------------------------------------------------------------------*/
+ * -------------------------------------------------------------------------*/
-/*
- * Initialisation
+#ifndef __SCHEDULE_H__
+#define __SCHEDULE_H__
+#include "OSThreads.h"
+
+/* initScheduler(), exitScheduler(), startTasks()
+ *
+ * Called from STG : no
+ * Locks assumed : none
*/
+extern void initScheduler ( void );
+extern void exitScheduler ( void );
-void initScheduler(void);
+/* 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
+ */
+#if defined(GRAN)
+void awakenBlockedQueue(StgBlockingQueueElement *q, StgClosure *node);
+#elif defined(PAR)
+void awakenBlockedQueue(StgBlockingQueueElement *q, StgClosure *node);
+#else
+void awakenBlockedQueue (StgTSO *tso);
+void awakenBlockedQueueNoLock (StgTSO *tso);
+#endif
-/*
- * Miscellany
+/* 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
*/
+#if defined(GRAN) || defined(PAR)
+StgBlockingQueueElement *unblockOne(StgBlockingQueueElement *bqe, StgClosure *node);
+#else
+StgTSO *unblockOne(StgTSO *tso);
+#endif
-void awaken_blocked_queue(StgTSO *tso);
+/* raiseAsync()
+ *
+ * Raises an exception asynchronously in the specified thread.
+ *
+ * Called from STG : yes
+ * Locks assumed : none
+ */
+void raiseAsync(StgTSO *tso, StgClosure *exception);
+void raiseAsyncWithLock(StgTSO *tso, StgClosure *exception);
+
+/* raiseExceptionHelper */
+StgWord raiseExceptionHelper (StgTSO *tso, StgClosure *exception);
+
+/* awaitEvent(rtsBool wait)
+ *
+ * Checks for blocked threads that need to be woken.
+ *
+ * Called from STG : NO
+ * Locks assumed : sched_mutex
+ */
+void awaitEvent(rtsBool wait); /* In Select.c */
+
+/* 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 */
+
+/* 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 */
+
+/* GetRoots(evac_fn f)
+ *
+ * Call f() for each root known to the scheduler.
+ *
+ * Called from STG : NO
+ * Locks assumed : ????
+ */
+void GetRoots(evac_fn);
+
+// ToDo: check whether all fcts below are used in the SMP version, too
+#if defined(GRAN)
+void awaken_blocked_queue(StgBlockingQueueElement *q, StgClosure *node);
+void unlink_from_bq(StgTSO* tso, StgClosure* node);
+void initThread(StgTSO *tso, nat stack_size, StgInt pri);
+#elif defined(PAR)
+nat run_queue_len(void);
+void awaken_blocked_queue(StgBlockingQueueElement *q, StgClosure *node);
+void initThread(StgTSO *tso, nat stack_size);
+#else
+char *info_type(StgClosure *closure); // dummy
+char *info_type_by_ip(StgInfoTable *ip); // dummy
+void awaken_blocked_queue(StgTSO *q);
void initThread(StgTSO *tso, nat stack_size);
-void interruptStgRts(void);
-void raiseAsync(StgTSO *tso, StgClosure *exception);
+#endif
-extern nat context_switch;
+/* Context switch flag.
+ * Locks required : sched_mutex
+ */
+extern nat RTS_VAR(context_switch);
+extern rtsBool RTS_VAR(interrupted);
-extern StgTSO *run_queue_hd, *run_queue_tl;
-extern StgTSO *blocked_queue_hd, *blocked_queue_tl;
+/* In Select.c */
+extern nat RTS_VAR(timestamp);
-#ifdef COMPILING_RTS_MAIN
-extern DLLIMPORT StgTSO *MainTSO; /* temporary hack */
+/* Thread queues.
+ * Locks required : sched_mutex
+ *
+ * In GranSim we have one run/blocked_queue per PE.
+ */
+#if defined(GRAN)
+// run_queue_hds defined in GranSim.h
#else
-extern StgTSO *MainTSO; /* temporary hack */
+extern StgTSO *RTS_VAR(run_queue_hd), *RTS_VAR(run_queue_tl);
+extern StgTSO *RTS_VAR(blocked_queue_hd), *RTS_VAR(blocked_queue_tl);
+extern StgTSO *RTS_VAR(sleeping_queue);
#endif
-#define END_TSO_QUEUE ((StgTSO *)(void*)&END_TSO_QUEUE_closure)
+/* Linked list of all threads. */
+extern StgTSO *RTS_VAR(all_threads);
-#define PUSH_ON_RUN_QUEUE(tso) \
- if (run_queue_hd == END_TSO_QUEUE) { \
+#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);
+#endif
+
+StgBool rtsSupportsBoundThreads(void);
+StgBool isThreadBound(StgTSO *tso);
+StgInt forkProcess(HsStablePtr *entry);
+
+extern 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 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;
+
+/* Main thread queue.
+ * Locks required: sched_mutex.
+ */
+extern StgMainThread *main_threads;
+
+void printAllThreads(void);
+#ifdef COMPILING_SCHEDULER
+static void printThreadBlockage(StgTSO *tso);
+static void printThreadStatus(StgTSO *tso);
+#endif
+/* debugging only
+ */
+#ifdef DEBUG
+void print_bq (StgClosure *node);
+#endif
+#if defined(PAR)
+void print_bqe (StgBlockingQueueElement *bqe);
+#endif
+
+void labelThread(StgPtr tso, char *label);
+
+/* -----------------------------------------------------------------------------
+ * Some convenient macros...
+ */
+
+/* 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.
+ */
+#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;
-#define END_CAF_LIST stgCast(StgCAF*,(void*)&END_TSO_QUEUE_closure)
+/* Push a thread on the beginning of the run queue. Used for
+ * newly awakened threads, so they get run as soon as possible.
+ */
+#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; \
+ }
+
+/* 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)
+
+/* 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; \
+ } \
+ 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())
+
+#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);
+#endif
+
+#ifdef DEBUG
+extern void sched_belch(char *s, ...);
+#endif
+
+#endif /* __SCHEDULE_H__ */
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