1 /* -----------------------------------------------------------------------------
3 * (c) The GHC Team 1998-1999
5 * Prototypes for functions in Schedule.c
6 * (RTS internal scheduler interface)
8 * -------------------------------------------------------------------------*/
10 #ifndef __SCHEDULE_H__
11 #define __SCHEDULE_H__
12 #include "OSThreads.h"
14 /* initScheduler(), exitScheduler(), startTasks()
16 * Called from STG : no
17 * Locks assumed : none
19 extern void initScheduler ( void );
20 extern void exitScheduler ( void );
22 /* awakenBlockedQueue()
24 * Takes a pointer to the beginning of a blocked TSO queue, and
25 * wakes up the entire queue.
27 * Called from STG : yes
28 * Locks assumed : none
31 void awakenBlockedQueue(StgBlockingQueueElement *q, StgClosure *node);
33 void awakenBlockedQueue(StgBlockingQueueElement *q, StgClosure *node);
35 void awakenBlockedQueue (StgTSO *tso);
36 void awakenBlockedQueueNoLock (StgTSO *tso);
41 * Takes a pointer to the beginning of a blocked TSO queue, and
42 * removes the first thread, placing it on the runnable queue.
44 * Called from STG : yes
45 * Locks assumed : none
47 #if defined(GRAN) || defined(PAR)
48 StgBlockingQueueElement *unblockOne(StgBlockingQueueElement *bqe, StgClosure *node);
50 StgTSO *unblockOne(StgTSO *tso);
55 * Raises an exception asynchronously in the specified thread.
57 * Called from STG : yes
58 * Locks assumed : none
60 void raiseAsync(StgTSO *tso, StgClosure *exception);
61 void raiseAsyncWithLock(StgTSO *tso, StgClosure *exception);
63 /* raiseExceptionHelper */
64 StgWord raiseExceptionHelper (StgTSO *tso, StgClosure *exception);
66 /* awaitEvent(rtsBool wait)
68 * Checks for blocked threads that need to be woken.
70 * Called from STG : NO
71 * Locks assumed : sched_mutex
73 void awaitEvent(rtsBool wait); /* In Select.c */
75 /* wakeUpSleepingThreads(nat ticks)
77 * Wakes up any sleeping threads whose timers have expired.
79 * Called from STG : NO
80 * Locks assumed : sched_mutex
82 rtsBool wakeUpSleepingThreads(nat); /* In Select.c */
84 /* wakeBlockedWorkerThread()
86 * If a worker thread is currently blocked in awaitEvent(), interrupt it.
88 * Called from STG : NO
89 * Locks assumed : sched_mutex
91 void wakeBlockedWorkerThread(void); /* In Select.c */
93 /* resetWorkerWakeupPipeAfterFork()
95 * Notify Select.c that a fork() has occured
97 * Called from STG : NO
98 * Locks assumed : don't care, but must be called right after fork()
100 void resetWorkerWakeupPipeAfterFork(void); /* In Select.c */
102 /* GetRoots(evac_fn f)
104 * Call f() for each root known to the scheduler.
106 * Called from STG : NO
107 * Locks assumed : ????
109 void GetRoots(evac_fn);
111 // ToDo: check whether all fcts below are used in the SMP version, too
113 void awaken_blocked_queue(StgBlockingQueueElement *q, StgClosure *node);
114 void unlink_from_bq(StgTSO* tso, StgClosure* node);
115 void initThread(StgTSO *tso, nat stack_size, StgInt pri);
117 nat run_queue_len(void);
118 void awaken_blocked_queue(StgBlockingQueueElement *q, StgClosure *node);
119 void initThread(StgTSO *tso, nat stack_size);
121 char *info_type(StgClosure *closure); // dummy
122 char *info_type_by_ip(StgInfoTable *ip); // dummy
123 void awaken_blocked_queue(StgTSO *q);
124 void initThread(StgTSO *tso, nat stack_size);
127 /* Context switch flag.
128 * Locks required : sched_mutex
130 extern nat RTS_VAR(context_switch);
131 extern rtsBool RTS_VAR(interrupted);
134 extern nat RTS_VAR(timestamp);
137 * Locks required : sched_mutex
139 * In GranSim we have one run/blocked_queue per PE.
142 // run_queue_hds defined in GranSim.h
144 extern StgTSO *RTS_VAR(run_queue_hd), *RTS_VAR(run_queue_tl);
145 extern StgTSO *RTS_VAR(blocked_queue_hd), *RTS_VAR(blocked_queue_tl);
146 extern StgTSO *RTS_VAR(sleeping_queue);
148 /* Linked list of all threads. */
149 extern StgTSO *RTS_VAR(all_threads);
151 #if defined(RTS_SUPPORTS_THREADS)
152 /* Schedule.c has detailed info on what these do */
153 extern Mutex RTS_VAR(sched_mutex);
154 extern Condition RTS_VAR(returning_worker_cond);
155 extern nat RTS_VAR(rts_n_waiting_workers);
156 extern nat RTS_VAR(rts_n_waiting_tasks);
159 StgBool isThreadBound(StgTSO *tso);
161 extern SchedulerStatus rts_mainLazyIO(HaskellObj p, /*out*/HaskellObj *ret);
164 /* Called by shutdown_handler(). */
165 void interruptStgRts ( void );
167 void raiseAsync(StgTSO *tso, StgClosure *exception);
168 nat run_queue_len(void);
170 void resurrectThreads( StgTSO * );
174 * These are the threads which clients have requested that we run.
176 * In a 'threaded' build, each of these corresponds to one bound thread.
177 * The pointer to the StgMainThread is passed as a parameter to schedule;
178 * this invocation of schedule will always pass this main thread's
179 * bound_thread_cond to waitForkWorkCapability; OS-thread-switching
180 * takes place using passCapability.
182 * In non-threaded builds, clients are strictly nested: the first client calls
183 * into the RTS, which might call out again to C with a _ccall_GC, and
184 * eventually re-enter the RTS.
186 * This is non-abstract at the moment because the garbage collector
187 * treats pointers to TSOs from the main thread list as "weak" - these
188 * pointers won't prevent a thread from receiving a BlockedOnDeadMVar
191 * Main threads information is kept in a linked list:
193 typedef struct StgMainThread_ {
195 SchedulerStatus stat;
197 #if defined(RTS_SUPPORTS_THREADS)
198 #if defined(THREADED_RTS)
199 Condition bound_thread_cond;
204 struct StgMainThread_ *prev;
205 struct StgMainThread_ *link;
208 /* Main thread queue.
209 * Locks required: sched_mutex.
211 extern StgMainThread *main_threads;
213 void printAllThreads(void);
214 #ifdef COMPILING_SCHEDULER
215 static void printThreadBlockage(StgTSO *tso);
216 static void printThreadStatus(StgTSO *tso);
221 void print_bq (StgClosure *node);
224 void print_bqe (StgBlockingQueueElement *bqe);
227 void labelThread(StgPtr tso, char *label);
229 /* -----------------------------------------------------------------------------
230 * Some convenient macros...
233 /* END_TSO_QUEUE and friends now defined in includes/StgMiscClosures.h */
235 /* Add a thread to the end of the run queue.
236 * NOTE: tso->link should be END_TSO_QUEUE before calling this macro.
238 #define APPEND_TO_RUN_QUEUE(tso) \
239 ASSERT(tso->link == END_TSO_QUEUE); \
240 if (run_queue_hd == END_TSO_QUEUE) { \
241 run_queue_hd = tso; \
243 run_queue_tl->link = tso; \
247 /* Push a thread on the beginning of the run queue. Used for
248 * newly awakened threads, so they get run as soon as possible.
250 #define PUSH_ON_RUN_QUEUE(tso) \
251 tso->link = run_queue_hd; \
252 run_queue_hd = tso; \
253 if (run_queue_tl == END_TSO_QUEUE) { \
254 run_queue_tl = tso; \
257 /* Pop the first thread off the runnable queue.
259 #define POP_RUN_QUEUE(pt) \
260 do { StgTSO *__tmp_t = run_queue_hd; \
261 if (__tmp_t != END_TSO_QUEUE) { \
262 run_queue_hd = __tmp_t->link; \
263 __tmp_t->link = END_TSO_QUEUE; \
264 if (run_queue_hd == END_TSO_QUEUE) { \
265 run_queue_tl = END_TSO_QUEUE; \
271 /* Add a thread to the end of the blocked queue.
273 #define APPEND_TO_BLOCKED_QUEUE(tso) \
274 ASSERT(tso->link == END_TSO_QUEUE); \
275 if (blocked_queue_hd == END_TSO_QUEUE) { \
276 blocked_queue_hd = tso; \
278 blocked_queue_tl->link = tso; \
280 blocked_queue_tl = tso;
282 /* Check whether various thread queues are empty
284 #define EMPTY_QUEUE(q) (q == END_TSO_QUEUE)
286 #define EMPTY_RUN_QUEUE() (EMPTY_QUEUE(run_queue_hd))
287 #define EMPTY_BLOCKED_QUEUE() (EMPTY_QUEUE(blocked_queue_hd))
288 #define EMPTY_SLEEPING_QUEUE() (EMPTY_QUEUE(sleeping_queue))
290 #define EMPTY_THREAD_QUEUES() (EMPTY_RUN_QUEUE() && \
291 EMPTY_BLOCKED_QUEUE() && \
292 EMPTY_SLEEPING_QUEUE())
294 #if defined(RTS_SUPPORTS_THREADS)
295 /* If no task is waiting for a capability,
296 * and if there is work to be done
297 * or if we need to wait for IO or delay requests,
298 * spawn a new worker thread.
301 startSchedulerTaskIfNecessary(void);
305 extern void sched_belch(char *s, ...)
306 GNU_ATTRIBUTE(format (printf, 1, 2));
309 #endif /* __SCHEDULE_H__ */