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/* -----------------------------------------------------------------------------
*
* (c) The GHC Team 1998-2005
*
* Prototypes for functions in Schedule.c
* (RTS internal scheduler interface)
*
* -------------------------------------------------------------------------*/
#pragma once
#include "rts/OSThreads.h"
#include "Capability.h"
#include "Trace.h"
#include "BeginPrivate.h"
/* initScheduler(), exitScheduler()
* Called from STG : no
* Locks assumed : none
*/
void initScheduler (void);
void exitScheduler (bool wait_foreign);
void freeScheduler (void);
void markScheduler (evac_fn evac, void *user);
// 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 (Capability *cap, 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. See Note [shutdown] in Schedule.c.
*/
#define SCHED_RUNNING 0 /* running as normal */
#define SCHED_INTERRUPTING 1 /* 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, and controls the disabling of the interval timer.
*
* The timer interrupt transitions ACTIVITY_YES into
* ACTIVITY_MAYBE_NO, waits for RtsFlags.GcFlags.idleGCDelayTime,
* and then:
* - if idle GC is no, set ACTIVITY_INACTIVE and wakeUpRts()
* - if idle GC is off, set ACTIVITY_DONE_GC and stopTimer()
*
* If the scheduler finds ACTIVITY_INACTIVE, then it sets
* ACTIVITY_DONE_GC, performs the GC and calls stopTimer().
*
* If the scheduler finds ACTIVITY_DONE_GC and it has a thread to run,
* it enables the timer again with startTimer().
*/
#define ACTIVITY_YES 0
// the RTS is active
#define ACTIVITY_MAYBE_NO 1
// no activity since the last timer signal
#define ACTIVITY_INACTIVE 2
// RtsFlags.GcFlags.idleGCDelayTime has passed with no activity
#define ACTIVITY_DONE_GC 3
// like ACTIVITY_INACTIVE, but we've done a GC too (if idle GC is
// enabled) and the interval timer is now turned off.
/* 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
*/
#if !defined(THREADED_RTS)
extern StgTSO *blocked_queue_hd, *blocked_queue_tl;
extern StgTSO *sleeping_queue;
#endif
extern bool 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/stg/MiscClosures.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;
tso->block_info.prev = END_TSO_QUEUE;
} else {
setTSOLink(cap, cap->run_queue_tl, tso);
setTSOPrev(cap, tso, cap->run_queue_tl);
}
cap->run_queue_tl = tso;
cap->n_run_queue++;
}
/* 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);
tso->block_info.prev = END_TSO_QUEUE;
if (cap->run_queue_hd != END_TSO_QUEUE) {
setTSOPrev(cap, cap->run_queue_hd, tso);
}
cap->run_queue_hd = tso;
if (cap->run_queue_tl == END_TSO_QUEUE) {
cap->run_queue_tl = tso;
}
cap->n_run_queue++;
}
/* 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;
if (t->_link != END_TSO_QUEUE) {
t->_link->block_info.prev = END_TSO_QUEUE;
}
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;
}
cap->n_run_queue--;
return t;
}
INLINE_HEADER StgTSO *
peekRunQueue (Capability *cap)
{
return cap->run_queue_hd;
}
void promoteInRunQueue (Capability *cap, StgTSO *tso);
/* 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 bool
emptyQueue (StgTSO *q)
{
return (q == END_TSO_QUEUE);
}
INLINE_HEADER bool
emptyRunQueue(Capability *cap)
{
return cap->n_run_queue == 0;
}
INLINE_HEADER void
truncateRunQueue(Capability *cap)
{
cap->run_queue_hd = END_TSO_QUEUE;
cap->run_queue_tl = END_TSO_QUEUE;
cap->n_run_queue = 0;
}
#if !defined(THREADED_RTS)
#define EMPTY_BLOCKED_QUEUE() (emptyQueue(blocked_queue_hd))
#define EMPTY_SLEEPING_QUEUE() (emptyQueue(sleeping_queue))
#endif
INLINE_HEADER bool
emptyThreadQueues(Capability *cap)
{
return emptyRunQueue(cap)
#if !defined(THREADED_RTS)
&& EMPTY_BLOCKED_QUEUE() && EMPTY_SLEEPING_QUEUE()
#endif
;
}
#endif /* !IN_STG_CODE */
#include "EndPrivate.h"
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