1 /* -----------------------------------------------------------------------------
2 * $Id: Schedule.h,v 1.32 2002/04/10 11:43:46 stolz Exp $
4 * (c) The GHC Team 1998-1999
6 * Prototypes for functions in Schedule.c
7 * (RTS internal scheduler interface)
9 * -------------------------------------------------------------------------*/
11 #ifndef __SCHEDULE_H__
12 #define __SCHEDULE_H__
13 #include "OSThreads.h"
15 /* initScheduler(), exitScheduler(), startTasks()
17 * Called from STG : no
18 * Locks assumed : none
20 extern void initScheduler ( void );
21 extern void exitScheduler ( void );
23 /* awakenBlockedQueue()
25 * Takes a pointer to the beginning of a blocked TSO queue, and
26 * wakes up the entire queue.
28 * Called from STG : yes
29 * Locks assumed : none
32 void awakenBlockedQueue(StgBlockingQueueElement *q, StgClosure *node);
34 void awakenBlockedQueue(StgBlockingQueueElement *q, StgClosure *node);
36 void awakenBlockedQueue(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);
64 * Raises an exception asynchronously in the specified thread.
66 * Called from STG : NO
67 * Locks assumed : sched_mutex
69 void awaitEvent(rtsBool wait); /* In Select.c */
71 /* wakeUpSleepingThreads(nat ticks)
73 * Wakes up any sleeping threads whose timers have expired.
75 * Called from STG : NO
76 * Locks assumed : sched_mutex
78 rtsBool wakeUpSleepingThreads(nat); /* In Select.c */
80 /* GetRoots(evac_fn f)
82 * Call f() for each root known to the scheduler.
84 * Called from STG : NO
85 * Locks assumed : ????
87 void GetRoots(evac_fn);
89 // ToDo: check whether all fcts below are used in the SMP version, too
91 void awaken_blocked_queue(StgBlockingQueueElement *q, StgClosure *node);
92 void unlink_from_bq(StgTSO* tso, StgClosure* node);
93 void initThread(StgTSO *tso, nat stack_size, StgInt pri);
95 nat run_queue_len(void);
96 void awaken_blocked_queue(StgBlockingQueueElement *q, StgClosure *node);
97 void initThread(StgTSO *tso, nat stack_size);
99 char *info_type(StgClosure *closure); // dummy
100 char *info_type_by_ip(StgInfoTable *ip); // dummy
101 void awaken_blocked_queue(StgTSO *q);
102 void initThread(StgTSO *tso, nat stack_size);
105 /* Context switch flag.
106 * Locks required : sched_mutex
108 extern nat context_switch;
109 extern rtsBool interrupted;
112 extern nat timestamp;
115 * Locks required : sched_mutex
117 * In GranSim we have one run/blocked_queue per PE.
120 // run_queue_hds defined in GranSim.h
122 extern StgTSO *run_queue_hd, *run_queue_tl;
123 extern StgTSO *blocked_queue_hd, *blocked_queue_tl;
124 extern StgTSO *sleeping_queue;
126 /* Linked list of all threads. */
127 extern StgTSO *all_threads;
129 #if defined(RTS_SUPPORTS_THREADS)
130 /* Schedule.c has detailed info on what these do */
131 extern Mutex sched_mutex;
132 extern Condition thread_ready_cond;
133 extern Condition returning_worker_cond;
134 extern nat rts_n_waiting_workers;
135 extern nat rts_n_waiting_tasks;
138 StgInt forkProcess(StgTSO *tso);
140 /* Sigh, RTS-internal versions of waitThread(), scheduleThread(), and
141 rts_evalIO() for the use by main() only. ToDo: better. */
142 extern SchedulerStatus waitThread_(StgTSO *tso,
143 /*out*/StgClosure **ret
144 #if defined(THREADED_RTS)
145 , rtsBool blockWaiting
148 extern SchedulerStatus rts_mainEvalIO(HaskellObj p, /*out*/HaskellObj *ret);
151 /* Called by shutdown_handler(). */
152 void interruptStgRts ( void );
154 void raiseAsync(StgTSO *tso, StgClosure *exception);
155 nat run_queue_len(void);
157 void resurrectThreads( StgTSO * );
161 * These are the threads which clients have requested that we run.
163 * In a 'threaded' build, we might have several concurrent clients all
164 * waiting for results, and each one will wait on a condition variable
165 * until the result is available.
167 * In non-SMP, clients are strictly nested: the first client calls
168 * into the RTS, which might call out again to C with a _ccall_GC, and
169 * eventually re-enter the RTS.
171 * This is non-abstract at the moment because the garbage collector
172 * treats pointers to TSOs from the main thread list as "weak" - these
173 * pointers won't prevent a thread from receiving a BlockedOnDeadMVar
176 * Main threads information is kept in a linked list:
178 typedef struct StgMainThread_ {
180 SchedulerStatus stat;
182 #if defined(RTS_SUPPORTS_THREADS)
185 struct StgMainThread_ *link;
188 /* Main thread queue.
189 * Locks required: sched_mutex.
191 extern StgMainThread *main_threads;
196 void printThreadBlockage(StgTSO *tso);
197 void printThreadStatus(StgTSO *tso);
198 void printAllThreads(void);
200 void print_bq (StgClosure *node);
202 void print_bqe (StgBlockingQueueElement *bqe);
205 /* -----------------------------------------------------------------------------
206 * Some convenient macros...
209 /* END_TSO_QUEUE and friends now defined in includes/StgMiscClosures.h */
211 /* Add a thread to the end of the run queue.
212 * NOTE: tso->link should be END_TSO_QUEUE before calling this macro.
214 #define APPEND_TO_RUN_QUEUE(tso) \
215 ASSERT(tso->link == END_TSO_QUEUE); \
216 if (run_queue_hd == END_TSO_QUEUE) { \
217 run_queue_hd = tso; \
219 run_queue_tl->link = tso; \
223 /* Push a thread on the beginning of the run queue. Used for
224 * newly awakened threads, so they get run as soon as possible.
226 #define PUSH_ON_RUN_QUEUE(tso) \
227 tso->link = run_queue_hd; \
228 run_queue_hd = tso; \
229 if (run_queue_tl == END_TSO_QUEUE) { \
230 run_queue_tl = tso; \
233 /* Pop the first thread off the runnable queue.
235 #define POP_RUN_QUEUE() \
236 ({ StgTSO *t = run_queue_hd; \
237 if (t != END_TSO_QUEUE) { \
238 run_queue_hd = t->link; \
239 t->link = END_TSO_QUEUE; \
240 if (run_queue_hd == END_TSO_QUEUE) { \
241 run_queue_tl = END_TSO_QUEUE; \
247 /* Add a thread to the end of the blocked queue.
249 #define APPEND_TO_BLOCKED_QUEUE(tso) \
250 ASSERT(tso->link == END_TSO_QUEUE); \
251 if (blocked_queue_hd == END_TSO_QUEUE) { \
252 blocked_queue_hd = tso; \
254 blocked_queue_tl->link = tso; \
256 blocked_queue_tl = tso;
258 /* Signal that a runnable thread has become available, in
259 * case there are any waiting tasks to execute it.
261 #if defined(RTS_SUPPORTS_THREADS)
262 #define THREAD_RUNNABLE() \
263 if ( !noCapabilities() ) { \
264 signalCondition(&thread_ready_cond); \
268 #define THREAD_RUNNABLE() /* nothing */
271 /* Check whether various thread queues are empty
273 #define EMPTY_QUEUE(q) (q == END_TSO_QUEUE)
275 #define EMPTY_RUN_QUEUE() (EMPTY_QUEUE(run_queue_hd))
276 #define EMPTY_BLOCKED_QUEUE() (EMPTY_QUEUE(blocked_queue_hd))
277 #define EMPTY_SLEEPING_QUEUE() (EMPTY_QUEUE(sleeping_queue))
279 #define EMPTY_THREAD_QUEUES() (EMPTY_RUN_QUEUE() && \
280 EMPTY_BLOCKED_QUEUE() && \
281 EMPTY_SLEEPING_QUEUE())
283 #endif /* __SCHEDULE_H__ */