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/* -----------------------------------------------------------------------------
*
* (c) The GHC Team 1998-2005
*
* Prototypes for functions in Schedule.c
* (RTS internal scheduler interface)
*
* -------------------------------------------------------------------------*/
#ifndef SCHEDULE_H
#define SCHEDULE_H
#include "rts/OSThreads.h"
#include "Capability.h"
#include "Trace.h"
BEGIN_RTS_PRIVATE
/* initScheduler(), exitScheduler()
* Called from STG : no
* Locks assumed : none
*/
void initScheduler (void);
void exitScheduler (rtsBool wait_foreign);
void freeScheduler (void);
// Place a new thread on the run queue of the current Capability
void scheduleThread (Capability *cap, StgTSO *tso);
// Place a new thread on the run queue of a specified Capability
// (cap is the currently owned Capability, cpu is the number of
// the desired Capability).
void scheduleThreadOn(Capability *cap, StgWord cpu, StgTSO *tso);
/* wakeUpRts()
*
* Causes an OS thread to wake up and run the scheduler, if necessary.
*/
#if defined(THREADED_RTS)
void wakeUpRts(void);
#endif
/* raiseExceptionHelper */
StgWord raiseExceptionHelper (StgRegTable *reg, StgTSO *tso, StgClosure *exception);
/* findRetryFrameHelper */
StgWord findRetryFrameHelper (StgTSO *tso);
/* Entry point for a new worker */
void scheduleWorker (Capability *cap, Task *task);
/* 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_SHUTTING_DOWN 2 /* final shutdown */
extern volatile StgWord 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 volatile StgWord recent_activity;
/* Thread queues.
* Locks required : sched_mutex
*
* In GranSim we have one run/blocked_queue per PE.
*/
extern StgTSO *blackhole_queue;
#if !defined(THREADED_RTS)
extern StgTSO *blocked_queue_hd, *blocked_queue_tl;
extern StgTSO *sleeping_queue;
#endif
/* 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;
extern rtsBool heap_overflow;
#if defined(THREADED_RTS)
extern Mutex sched_mutex;
#endif
/* Called by shutdown_handler(). */
void interruptStgRts (void);
void resurrectThreads (StgTSO *);
/* -----------------------------------------------------------------------------
* 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.
*/
EXTERN_INLINE void
appendToRunQueue (Capability *cap, StgTSO *tso);
EXTERN_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 {
setTSOLink(cap, cap->run_queue_tl, tso);
}
cap->run_queue_tl = tso;
traceEventThreadRunnable (cap, tso);
}
/* Push a thread on the beginning of the run queue.
* ASSUMES: cap->running_task is the current task.
*/
EXTERN_INLINE void
pushOnRunQueue (Capability *cap, StgTSO *tso);
EXTERN_INLINE void
pushOnRunQueue (Capability *cap, StgTSO *tso)
{
setTSOLink(cap, tso, 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.
*/
INLINE_HEADER 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; // no write barrier req'd
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.
*/
#if !defined(THREADED_RTS)
INLINE_HEADER void
appendToBlockedQueue(StgTSO *tso)
{
ASSERT(tso->_link == END_TSO_QUEUE);
if (blocked_queue_hd == END_TSO_QUEUE) {
blocked_queue_hd = tso;
} else {
setTSOLink(&MainCapability, blocked_queue_tl, tso);
}
blocked_queue_tl = tso;
}
#endif
/* Check whether various thread queues are empty
*/
INLINE_HEADER rtsBool
emptyQueue (StgTSO *q)
{
return (q == END_TSO_QUEUE);
}
INLINE_HEADER 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
INLINE_HEADER rtsBool
emptyThreadQueues(Capability *cap)
{
return emptyRunQueue(cap)
#if !defined(THREADED_RTS)
&& EMPTY_BLOCKED_QUEUE() && EMPTY_SLEEPING_QUEUE()
#endif
;
}
#endif /* !IN_STG_CODE */
END_RTS_PRIVATE
#endif /* SCHEDULE_H */
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