Commit 68b76e0e authored by Duncan Coutts's avatar Duncan Coutts
Browse files

Rearrange shutdownCapability code slightly

This is mostly for the beneift of having sensible places to put tracing
code later. We want a code path that has somewhere to trace (in order):
 (1) starting up all capabilities;
 (2) N * starting up an individual capability;
 (3) N * shutting down an individual capability;
 (4) shutting down all capabilities.
This has to work in both threaded and non-threaded modes.

Locations (1) and (2) are provided by initCapabilities and
initCapability respectively. Previously, there was no loccation for (4)
and while shutdownCapability should be usable for (3) it was only called
in the !THREADED_RTS case.

Now, shutdownCapability is called unconditionally (and the body is
conditonal on THREADED_RTS) and there is a new shutdownCapabilities that
calls shutdownCapability in a loop.
parent cb2d37da
......@@ -676,6 +676,31 @@ prodCapability (Capability *cap, Task *task)
RELEASE_LOCK(&cap->lock);
}
/* ----------------------------------------------------------------------------
* tryGrabCapability
*
* Attempt to gain control of a Capability if it is free.
*
* ------------------------------------------------------------------------- */
rtsBool
tryGrabCapability (Capability *cap, Task *task)
{
if (cap->running_task != NULL) return rtsFalse;
ACQUIRE_LOCK(&cap->lock);
if (cap->running_task != NULL) {
RELEASE_LOCK(&cap->lock);
return rtsFalse;
}
task->cap = cap;
cap->running_task = task;
RELEASE_LOCK(&cap->lock);
return rtsTrue;
}
#endif /* THREADED_RTS */
/* ----------------------------------------------------------------------------
* shutdownCapability
*
......@@ -692,8 +717,9 @@ prodCapability (Capability *cap, Task *task)
* ------------------------------------------------------------------------- */
void
shutdownCapability (Capability *cap, Task *task, rtsBool safe)
shutdownCapability (Capability *cap USED_IF_THREADS, Task *task USED_IF_THREADS, rtsBool safe USED_IF_THREADS)
{
#if defined(THREADED_RTS)
nat i;
task->cap = cap;
......@@ -785,33 +811,20 @@ shutdownCapability (Capability *cap, Task *task, rtsBool safe)
// threads performing foreign calls that will eventually try to
// return via resumeThread() and attempt to grab cap->lock.
// closeMutex(&cap->lock);
#endif /* THREADED_RTS */
}
/* ----------------------------------------------------------------------------
* tryGrabCapability
*
* Attempt to gain control of a Capability if it is free.
*
* ------------------------------------------------------------------------- */
rtsBool
tryGrabCapability (Capability *cap, Task *task)
void
shutdownCapabilities(Task *task, rtsBool safe)
{
if (cap->running_task != NULL) return rtsFalse;
ACQUIRE_LOCK(&cap->lock);
if (cap->running_task != NULL) {
RELEASE_LOCK(&cap->lock);
return rtsFalse;
nat i;
for (i=0; i < n_capabilities; i++) {
ASSERT(task->incall->tso == NULL);
shutdownCapability(&capabilities[i], task, safe);
}
task->cap = cap;
cap->running_task = task;
RELEASE_LOCK(&cap->lock);
return rtsTrue;
}
#endif /* THREADED_RTS */
static void
freeCapability (Capability *cap)
{
......
......@@ -240,11 +240,6 @@ void prodCapability (Capability *cap, Task *task);
//
void prodAllCapabilities (void);
// Waits for a capability to drain of runnable threads and workers,
// and then acquires it. Used at shutdown time.
//
void shutdownCapability (Capability *cap, Task *task, rtsBool wait_foreign);
// Attempt to gain control of a Capability if it is free.
//
rtsBool tryGrabCapability (Capability *cap, Task *task);
......@@ -270,6 +265,15 @@ extern void grabCapability (Capability **pCap);
#endif /* !THREADED_RTS */
// Waits for a capability to drain of runnable threads and workers,
// and then acquires it. Used at shutdown time.
//
void shutdownCapability (Capability *cap, Task *task, rtsBool wait_foreign);
// Shut down all capabilities.
//
void shutdownCapabilities(Task *task, rtsBool wait_foreign);
// cause all capabilities to context switch as soon as possible.
void setContextSwitches(void);
INLINE_HEADER void contextSwitchCapability(Capability *cap);
......
......@@ -2030,16 +2030,7 @@ exitScheduler (rtsBool wait_foreign USED_IF_THREADS)
}
sched_state = SCHED_SHUTTING_DOWN;
#if defined(THREADED_RTS)
{
nat i;
for (i = 0; i < n_capabilities; i++) {
ASSERT(task->incall->tso == NULL);
shutdownCapability(&capabilities[i], task, wait_foreign);
}
}
#endif
shutdownCapabilities(task, wait_foreign);
boundTaskExiting(task);
}
......
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