#include "Interpreter.h"
#include "Printer.h"
#include "RtsSignals.h"
-#include "Sanity.h"
+#include "sm/Sanity.h"
#include "Stats.h"
#include "STM.h"
#include "Prelude.h"
#include "Proftimer.h"
#include "ProfHeap.h"
#include "Weak.h"
-#include "eventlog/EventLog.h"
#include "sm/GC.h" // waitForGcThreads, releaseGCThreads, N
#include "Sparks.h"
#include "Capability.h"
#endif
static void scheduleStartSignalHandlers (Capability *cap);
static void scheduleCheckBlockedThreads (Capability *cap);
-static void scheduleCheckWakeupThreads(Capability *cap USED_IF_NOT_THREADS);
+static void scheduleProcessInbox(Capability *cap);
static void scheduleCheckBlackHoles (Capability *cap);
static void scheduleDetectDeadlock (Capability *cap, Task *task);
static void schedulePushWork(Capability *cap, Task *task);
static rtsBool checkBlackHoles(Capability *cap);
static StgTSO *threadStackOverflow(Capability *cap, StgTSO *tso);
-static StgTSO *threadStackUnderflow(Task *task, StgTSO *tso);
+static StgTSO *threadStackUnderflow(Capability *cap, Task *task, StgTSO *tso);
static void deleteThread (Capability *cap, StgTSO *tso);
static void deleteAllThreads (Capability *cap);
static void deleteThread_(Capability *cap, StgTSO *tso);
#endif
-#ifdef DEBUG
-static char *whatNext_strs[] = {
- [0] = "(unknown)",
- [ThreadRunGHC] = "ThreadRunGHC",
- [ThreadInterpret] = "ThreadInterpret",
- [ThreadKilled] = "ThreadKilled",
- [ThreadRelocated] = "ThreadRelocated",
- [ThreadComplete] = "ThreadComplete"
-};
-#endif
-
/* -----------------------------------------------------------------------------
* Putting a thread on the run queue: different scheduling policies
* -------------------------------------------------------------------------- */
rtsBool ready_to_gc;
#if defined(THREADED_RTS)
rtsBool first = rtsTrue;
-#endif
rtsBool force_yield = rtsFalse;
+#endif
cap = initialCapability;
// The sched_mutex is *NOT* held
// NB. on return, we still hold a capability.
- debugTrace (DEBUG_sched,
- "### NEW SCHEDULER LOOP (task: %p, cap: %p)",
- task, initialCapability);
+ debugTrace (DEBUG_sched, "cap %d: schedule()", initialCapability->no);
schedulePreLoop();
// If we are a worker, just exit. If we're a bound thread
// then we will exit below when we've removed our TSO from
// the run queue.
- if (task->tso == NULL && emptyRunQueue(cap)) {
+ if (!isBoundTask(task) && emptyRunQueue(cap)) {
return cap;
}
break;
// Check whether we can run this thread in the current task.
// If not, we have to pass our capability to the right task.
{
- Task *bound = t->bound;
+ InCall *bound = t->bound;
if (bound) {
- if (bound == task) {
- debugTrace(DEBUG_sched,
- "### Running thread %lu in bound thread", (unsigned long)t->id);
+ if (bound->task == task) {
// yes, the Haskell thread is bound to the current native thread
} else {
debugTrace(DEBUG_sched,
- "### thread %lu bound to another OS thread", (unsigned long)t->id);
+ "thread %lu bound to another OS thread",
+ (unsigned long)t->id);
// no, bound to a different Haskell thread: pass to that thread
pushOnRunQueue(cap,t);
continue;
}
} else {
// The thread we want to run is unbound.
- if (task->tso) {
+ if (task->incall->tso) {
debugTrace(DEBUG_sched,
- "### this OS thread cannot run thread %lu", (unsigned long)t->id);
+ "this OS thread cannot run thread %lu",
+ (unsigned long)t->id);
// no, the current native thread is bound to a different
// Haskell thread, so pass it to any worker thread
pushOnRunQueue(cap,t);
// that.
cap->r.rCurrentTSO = t;
- debugTrace(DEBUG_sched, "-->> running thread %ld %s ...",
- (long)t->id, whatNext_strs[t->what_next]);
-
startHeapProfTimer();
// Check for exceptions blocked on this thread
ASSERT_FULL_CAPABILITY_INVARIANTS(cap,task);
ASSERT(t->cap == cap);
- ASSERT(t->bound ? t->bound->cap == cap : 1);
+ ASSERT(t->bound ? t->bound->task->cap == cap : 1);
prev_what_next = t->what_next;
if (prev == ACTIVITY_DONE_GC) {
startTimer();
}
- } else {
+ } else if (recent_activity != ACTIVITY_INACTIVE) {
+ // If we reached ACTIVITY_INACTIVE, then don't reset it until
+ // we've done the GC. The thread running here might just be
+ // the IO manager thread that handle_tick() woke up via
+ // wakeUpRts().
recent_activity = ACTIVITY_YES;
}
#endif
- postEvent(cap, EVENT_RUN_THREAD, t->id, 0);
+ traceEventRunThread(cap, t);
switch (prev_what_next) {
t->saved_winerror = GetLastError();
#endif
- postEvent (cap, EVENT_STOP_THREAD, t->id, ret);
+ traceEventStopThread(cap, t, ret);
#if defined(THREADED_RTS)
// If ret is ThreadBlocked, and this Task is bound to the TSO that
// that task->cap != cap. We better yield this Capability
// immediately and return to normaility.
if (ret == ThreadBlocked) {
- debugTrace(DEBUG_sched,
- "--<< thread %lu (%s) stopped: blocked",
- (unsigned long)t->id, whatNext_strs[t->what_next]);
force_yield = rtsTrue;
goto yield;
}
schedulePostRunThread(cap,t);
if (ret != StackOverflow) {
- t = threadStackUnderflow(task,t);
+ t = threadStackUnderflow(cap,task,t);
}
ready_to_gc = rtsFalse;
// list each time around the scheduler.
if (emptyRunQueue(cap)) { scheduleCheckBlackHoles(cap); }
- scheduleCheckWakeupThreads(cap);
+ scheduleProcessInbox(cap);
scheduleCheckBlockedThreads(cap);
// and this task it bound).
return (waiting_for_gc ||
cap->returning_tasks_hd != NULL ||
- (!emptyRunQueue(cap) && (task->tso == NULL
+ (!emptyRunQueue(cap) && (task->incall->tso == NULL
? cap->run_queue_hd->bound != NULL
- : cap->run_queue_hd->bound != task)));
+ : cap->run_queue_hd->bound != task->incall)));
}
// This is the single place where a Task goes to sleep. There are
if (!force_yield &&
!shouldYieldCapability(cap,task) &&
(!emptyRunQueue(cap) ||
- !emptyWakeupQueue(cap) ||
+ !emptyInbox(cap) ||
blackholes_need_checking ||
sched_state >= SCHED_INTERRUPTING))
return;
Capability *free_caps[n_capabilities], *cap0;
nat i, n_free_caps;
- // migration can be turned off with +RTS -qg
+ // migration can be turned off with +RTS -qm
if (!RtsFlags.ParFlags.migrate) return;
// Check whether we have more threads on our run queue, or sparks
for (i=0, n_free_caps=0; i < n_capabilities; i++) {
cap0 = &capabilities[i];
if (cap != cap0 && tryGrabCapability(cap0,task)) {
- if (!emptyRunQueue(cap0) || cap->returning_tasks_hd != NULL) {
+ if (!emptyRunQueue(cap0)
+ || cap->returning_tasks_hd != NULL
+ || cap->inbox != (Message*)END_TSO_QUEUE) {
// it already has some work, we just grabbed it at
// the wrong moment. Or maybe it's deadlocked!
releaseCapability(cap0);
next = t->_link;
t->_link = END_TSO_QUEUE;
if (t->what_next == ThreadRelocated
- || t->bound == task // don't move my bound thread
+ || t->bound == task->incall // don't move my bound thread
|| tsoLocked(t)) { // don't move a locked thread
setTSOLink(cap, prev, t);
prev = t;
setTSOLink(cap, prev, t);
prev = t;
} else {
- debugTrace(DEBUG_sched, "pushing thread %lu to capability %d", (unsigned long)t->id, free_caps[i]->no);
appendToRunQueue(free_caps[i],t);
- postEvent (cap, EVENT_MIGRATE_THREAD, t->id, free_caps[i]->no);
+ traceEventMigrateThread (cap, t, free_caps[i]->no);
- if (t->bound) { t->bound->cap = free_caps[i]; }
+ if (t->bound) { t->bound->task->cap = free_caps[i]; }
t->cap = free_caps[i];
i++;
}
if (spark != NULL) {
debugTrace(DEBUG_sched, "pushing spark %p to capability %d", spark, free_caps[i]->no);
- postEvent(free_caps[i], EVENT_STEAL_SPARK, t->id, cap->no);
+ traceEventStealSpark(free_caps[i], t, cap->no);
newSpark(&(free_caps[i]->r), spark);
}
* Check for threads woken up by other Capabilities
* ------------------------------------------------------------------------- */
+#if defined(THREADED_RTS)
+static void
+executeMessage (Capability *cap, Message *m)
+{
+ const StgInfoTable *i;
+
+loop:
+ write_barrier(); // allow m->header to be modified by another thread
+ i = m->header.info;
+ if (i == &stg_MSG_WAKEUP_info)
+ {
+ MessageWakeup *w = (MessageWakeup *)m;
+ StgTSO *tso = w->tso;
+ debugTraceCap(DEBUG_sched, cap, "message: wakeup thread %ld",
+ (lnat)tso->id);
+ ASSERT(tso->cap == cap);
+ ASSERT(tso->why_blocked == BlockedOnMsgWakeup);
+ ASSERT(tso->block_info.closure == (StgClosure *)m);
+ tso->why_blocked = NotBlocked;
+ appendToRunQueue(cap, tso);
+ }
+ else if (i == &stg_MSG_THROWTO_info)
+ {
+ MessageThrowTo *t = (MessageThrowTo *)m;
+ nat r;
+ const StgInfoTable *i;
+
+ i = lockClosure((StgClosure*)m);
+ if (i != &stg_MSG_THROWTO_info) {
+ unlockClosure((StgClosure*)m, i);
+ goto loop;
+ }
+
+ debugTraceCap(DEBUG_sched, cap, "message: throwTo %ld -> %ld",
+ (lnat)t->source->id, (lnat)t->target->id);
+
+ ASSERT(t->source->why_blocked == BlockedOnMsgThrowTo);
+ ASSERT(t->source->block_info.closure == (StgClosure *)m);
+
+ r = throwToMsg(cap, t);
+
+ switch (r) {
+ case THROWTO_SUCCESS:
+ ASSERT(t->source->sp[0] == (StgWord)&stg_block_throwto_info);
+ t->source->sp += 3;
+ unblockOne(cap, t->source);
+ // this message is done
+ unlockClosure((StgClosure*)m, &stg_IND_info);
+ break;
+ case THROWTO_BLOCKED:
+ // unlock the message
+ unlockClosure((StgClosure*)m, &stg_MSG_THROWTO_info);
+ break;
+ }
+ }
+ else if (i == &stg_IND_info)
+ {
+ // message was revoked
+ return;
+ }
+ else if (i == &stg_WHITEHOLE_info)
+ {
+ goto loop;
+ }
+ else
+ {
+ barf("executeMessage: %p", i);
+ }
+}
+#endif
+
static void
-scheduleCheckWakeupThreads(Capability *cap USED_IF_THREADS)
+scheduleProcessInbox (Capability *cap USED_IF_THREADS)
{
#if defined(THREADED_RTS)
- // Any threads that were woken up by other Capabilities get
- // appended to our run queue.
- if (!emptyWakeupQueue(cap)) {
- ACQUIRE_LOCK(&cap->lock);
- if (emptyRunQueue(cap)) {
- cap->run_queue_hd = cap->wakeup_queue_hd;
- cap->run_queue_tl = cap->wakeup_queue_tl;
- } else {
- setTSOLink(cap, cap->run_queue_tl, cap->wakeup_queue_hd);
- cap->run_queue_tl = cap->wakeup_queue_tl;
- }
- cap->wakeup_queue_hd = cap->wakeup_queue_tl = END_TSO_QUEUE;
- RELEASE_LOCK(&cap->lock);
+ Message *m;
+
+ while (!emptyInbox(cap)) {
+ ACQUIRE_LOCK(&cap->lock);
+ m = cap->inbox;
+ cap->inbox = m->link;
+ RELEASE_LOCK(&cap->lock);
+ executeMessage(cap, (Message *)m);
}
#endif
}
/* Probably a real deadlock. Send the current main thread the
* Deadlock exception.
*/
- if (task->tso) {
- switch (task->tso->why_blocked) {
+ if (task->incall->tso) {
+ switch (task->incall->tso->why_blocked) {
case BlockedOnSTM:
case BlockedOnBlackHole:
- case BlockedOnException:
+ case BlockedOnMsgThrowTo:
case BlockedOnMVar:
- throwToSingleThreaded(cap, task->tso,
+ throwToSingleThreaded(cap, task->incall->tso,
(StgClosure *)nonTermination_closure);
return;
default:
// partially-evaluated thunks on the heap.
throwToSingleThreaded_(cap, t, NULL, rtsTrue);
- ASSERT(get_itbl((StgClosure *)t->sp)->type == ATOMICALLY_FRAME);
+// ASSERT(get_itbl((StgClosure *)t->sp)->type == ATOMICALLY_FRAME);
}
}
debugTrace(DEBUG_sched,
"--<< thread %ld (%s) stopped: requesting a large block (size %ld)\n",
- (long)t->id, whatNext_strs[t->what_next], blocks);
+ (long)t->id, what_next_strs[t->what_next], blocks);
// don't do this if the nursery is (nearly) full, we'll GC first.
if (cap->r.rCurrentNursery->link != NULL ||
if (cap->r.rCurrentNursery->u.back != NULL) {
cap->r.rCurrentNursery->u.back->link = bd;
} else {
-#if !defined(THREADED_RTS)
- ASSERT(g0s0->blocks == cap->r.rCurrentNursery &&
- g0s0 == cap->r.rNursery);
-#endif
cap->r.rNursery->blocks = bd;
}
cap->r.rCurrentNursery->u.back = bd;
{
bdescr *x;
for (x = bd; x < bd + blocks; x++) {
- x->step = cap->r.rNursery;
- x->gen_no = 0;
+ initBdescr(x,g0,g0);
+ x->free = x->start;
x->flags = 0;
}
}
}
}
- debugTrace(DEBUG_sched,
- "--<< thread %ld (%s) stopped: HeapOverflow",
- (long)t->id, whatNext_strs[t->what_next]);
-
if (cap->r.rHpLim == NULL || cap->context_switch) {
// Sometimes we miss a context switch, e.g. when calling
// primitives in a tight loop, MAYBE_GC() doesn't check the
static void
scheduleHandleStackOverflow (Capability *cap, Task *task, StgTSO *t)
{
- debugTrace (DEBUG_sched,
- "--<< thread %ld (%s) stopped, StackOverflow",
- (long)t->id, whatNext_strs[t->what_next]);
-
/* just adjust the stack for this thread, then pop it back
* on the run queue.
*/
/* The TSO attached to this Task may have moved, so update the
* pointer to it.
*/
- if (task->tso == t) {
- task->tso = new_t;
+ if (task->incall->tso == t) {
+ task->incall->tso = new_t;
}
pushOnRunQueue(cap,new_t);
}
static rtsBool
scheduleHandleYield( Capability *cap, StgTSO *t, nat prev_what_next )
{
- // Reset the context switch flag. We don't do this just before
- // running the thread, because that would mean we would lose ticks
- // during GC, which can lead to unfair scheduling (a thread hogs
- // the CPU because the tick always arrives during GC). This way
- // penalises threads that do a lot of allocation, but that seems
- // better than the alternative.
- cap->context_switch = 0;
-
/* put the thread back on the run queue. Then, if we're ready to
* GC, check whether this is the last task to stop. If so, wake
* up the GC thread. getThread will block during a GC until the
* GC is finished.
*/
-#ifdef DEBUG
- if (t->what_next != prev_what_next) {
- debugTrace(DEBUG_sched,
- "--<< thread %ld (%s) stopped to switch evaluators",
- (long)t->id, whatNext_strs[t->what_next]);
- } else {
- debugTrace(DEBUG_sched,
- "--<< thread %ld (%s) stopped, yielding",
- (long)t->id, whatNext_strs[t->what_next]);
- }
-#endif
-
- IF_DEBUG(sanity,
- //debugBelch("&& Doing sanity check on yielding TSO %ld.", t->id);
- checkTSO(t));
+
ASSERT(t->_link == END_TSO_QUEUE);
// Shortcut if we're just switching evaluators: don't bother
// doing stack squeezing (which can be expensive), just run the
// thread.
- if (t->what_next != prev_what_next) {
+ if (cap->context_switch == 0 && t->what_next != prev_what_next) {
+ debugTrace(DEBUG_sched,
+ "--<< thread %ld (%s) stopped to switch evaluators",
+ (long)t->id, what_next_strs[t->what_next]);
return rtsTrue;
}
+ // Reset the context switch flag. We don't do this just before
+ // running the thread, because that would mean we would lose ticks
+ // during GC, which can lead to unfair scheduling (a thread hogs
+ // the CPU because the tick always arrives during GC). This way
+ // penalises threads that do a lot of allocation, but that seems
+ // better than the alternative.
+ cap->context_switch = 0;
+
+ IF_DEBUG(sanity,
+ //debugBelch("&& Doing sanity check on yielding TSO %ld.", t->id);
+ checkTSO(t));
+
addToRunQueue(cap,t);
return rtsFalse;
// exception, see maybePerformBlockedException().
#ifdef DEBUG
- if (traceClass(DEBUG_sched)) {
- debugTraceBegin("--<< thread %lu (%s) stopped: ",
- (unsigned long)t->id, whatNext_strs[t->what_next]);
- printThreadBlockage(t);
- debugTraceEnd();
- }
+ traceThreadStatus(DEBUG_sched, t);
#endif
}
* We also end up here if the thread kills itself with an
* uncaught exception, see Exception.cmm.
*/
- debugTrace(DEBUG_sched, "--++ thread %lu (%s) finished",
- (unsigned long)t->id, whatNext_strs[t->what_next]);
// blocked exceptions can now complete, even if the thread was in
- // blocked mode (see #2910). This unconditionally calls
- // lockTSO(), which ensures that we don't miss any threads that
- // are engaged in throwTo() with this thread as a target.
+ // blocked mode (see #2910).
awakenBlockedExceptionQueue (cap, t);
//
if (t->bound) {
- if (t->bound != task) {
+ if (t->bound != task->incall) {
#if !defined(THREADED_RTS)
// Must be a bound thread that is not the topmost one. Leave
// it on the run queue until the stack has unwound to the
#endif
}
- ASSERT(task->tso == t);
+ ASSERT(task->incall->tso == t);
if (t->what_next == ThreadComplete) {
if (task->ret) {
// NOTE: return val is tso->sp[1] (see StgStartup.hc)
- *(task->ret) = (StgClosure *)task->tso->sp[1];
+ *(task->ret) = (StgClosure *)task->incall->tso->sp[1];
}
task->stat = Success;
} else {
}
}
#ifdef DEBUG
- removeThreadLabel((StgWord)task->tso->id);
+ removeThreadLabel((StgWord)task->incall->tso->id);
#endif
+
+ // We no longer consider this thread and task to be bound to
+ // each other. The TSO lives on until it is GC'd, but the
+ // task is about to be released by the caller, and we don't
+ // want anyone following the pointer from the TSO to the
+ // defunct task (which might have already been
+ // re-used). This was a real bug: the GC updated
+ // tso->bound->tso which lead to a deadlock.
+ t->bound = NULL;
+ task->incall->tso = NULL;
+
return rtsTrue; // tells schedule() to return
}
if (sched_state < SCHED_INTERRUPTING
&& RtsFlags.ParFlags.parGcEnabled
&& N >= RtsFlags.ParFlags.parGcGen
- && ! oldest_gen->steps[0].mark)
+ && ! oldest_gen->mark)
{
gc_type = PENDING_GC_PAR;
} else {
if (gc_type == PENDING_GC_SEQ)
{
- postEvent(cap, EVENT_REQUEST_SEQ_GC, 0, 0);
+ traceEventRequestSeqGc(cap);
+ }
+ else
+ {
+ traceEventRequestParGc(cap);
+ debugTrace(DEBUG_sched, "ready_to_gc, grabbing GC threads");
+ }
+
+ // do this while the other Capabilities stop:
+ if (cap) scheduleCheckBlackHoles(cap);
+
+ if (gc_type == PENDING_GC_SEQ)
+ {
// single-threaded GC: grab all the capabilities
for (i=0; i < n_capabilities; i++) {
debugTrace(DEBUG_sched, "ready_to_gc, grabbing all the capabilies (%d/%d)", i, n_capabilities);
{
// multi-threaded GC: make sure all the Capabilities donate one
// GC thread each.
- postEvent(cap, EVENT_REQUEST_PAR_GC, 0, 0);
- debugTrace(DEBUG_sched, "ready_to_gc, grabbing GC threads");
-
waitForGcThreads(cap);
}
-#endif
- // so this happens periodically:
+#else /* !THREADED_RTS */
+
+ // do this while the other Capabilities stop:
if (cap) scheduleCheckBlackHoles(cap);
-
+
+#endif
+
IF_DEBUG(scheduler, printAllThreads());
delete_threads_and_gc:
heap_census = scheduleNeedHeapProfile(rtsTrue);
+ traceEventGcStart(cap);
#if defined(THREADED_RTS)
- postEvent(cap, EVENT_GC_START, 0, 0);
- debugTrace(DEBUG_sched, "doing GC");
// reset waiting_for_gc *before* GC, so that when the GC threads
// emerge they don't immediately re-enter the GC.
waiting_for_gc = 0;
#else
GarbageCollect(force_major || heap_census, 0, cap);
#endif
- postEvent(cap, EVENT_GC_END, 0, 0);
+ traceEventGcEnd(cap);
if (recent_activity == ACTIVITY_INACTIVE && force_major)
{
)
{
#ifdef FORKPROCESS_PRIMOP_SUPPORTED
- Task *task;
pid_t pid;
StgTSO* t,*next;
Capability *cap;
- nat s;
+ nat g;
#if defined(THREADED_RTS)
if (RtsFlags.ParFlags.nNodes > 1) {
// all Tasks, because they correspond to OS threads that are
// now gone.
- for (s = 0; s < total_steps; s++) {
- for (t = all_steps[s].threads; t != END_TSO_QUEUE; t = next) {
+ for (g = 0; g < RtsFlags.GcFlags.generations; g++) {
+ for (t = generations[g].threads; t != END_TSO_QUEUE; t = next) {
if (t->what_next == ThreadRelocated) {
next = t->_link;
} else {
// Any suspended C-calling Tasks are no more, their OS threads
// don't exist now:
- cap->suspended_ccalling_tasks = NULL;
+ cap->suspended_ccalls = NULL;
// Empty the threads lists. Otherwise, the garbage
// collector may attempt to resurrect some of these threads.
- for (s = 0; s < total_steps; s++) {
- all_steps[s].threads = END_TSO_QUEUE;
+ for (g = 0; g < RtsFlags.GcFlags.generations; g++) {
+ generations[g].threads = END_TSO_QUEUE;
}
- // Wipe the task list, except the current Task.
- ACQUIRE_LOCK(&sched_mutex);
- for (task = all_tasks; task != NULL; task=task->all_link) {
- if (task != cap->running_task) {
-#if defined(THREADED_RTS)
- initMutex(&task->lock); // see #1391
-#endif
- discardTask(task);
- }
- }
- RELEASE_LOCK(&sched_mutex);
+ discardTasksExcept(cap->running_task);
#if defined(THREADED_RTS)
// Wipe our spare workers list, they no longer exist. New
initTimer();
startTimer();
+#if defined(THREADED_RTS)
+ cap = ioManagerStartCap(cap);
+#endif
+
cap = rts_evalStableIO(cap, entry, NULL); // run the action
rts_checkSchedStatus("forkProcess",cap);
// NOTE: only safe to call if we own all capabilities.
StgTSO* t, *next;
- nat s;
+ nat g;
debugTrace(DEBUG_sched,"deleting all threads");
- for (s = 0; s < total_steps; s++) {
- for (t = all_steps[s].threads; t != END_TSO_QUEUE; t = next) {
- if (t->what_next == ThreadRelocated) {
- next = t->_link;
- } else {
- next = t->global_link;
- deleteThread(cap,t);
- }
- }
- }
+ for (g = 0; g < RtsFlags.GcFlags.generations; g++) {
+ for (t = generations[g].threads; t != END_TSO_QUEUE; t = next) {
+ if (t->what_next == ThreadRelocated) {
+ next = t->_link;
+ } else {
+ next = t->global_link;
+ deleteThread(cap,t);
+ }
+ }
+ }
// The run queue now contains a bunch of ThreadKilled threads. We
// must not throw these away: the main thread(s) will be in there
}
/* -----------------------------------------------------------------------------
- Managing the suspended_ccalling_tasks list.
+ Managing the suspended_ccalls list.
Locks required: sched_mutex
-------------------------------------------------------------------------- */
STATIC_INLINE void
suspendTask (Capability *cap, Task *task)
{
- ASSERT(task->next == NULL && task->prev == NULL);
- task->next = cap->suspended_ccalling_tasks;
- task->prev = NULL;
- if (cap->suspended_ccalling_tasks) {
- cap->suspended_ccalling_tasks->prev = task;
- }
- cap->suspended_ccalling_tasks = task;
+ InCall *incall;
+
+ incall = task->incall;
+ ASSERT(incall->next == NULL && incall->prev == NULL);
+ incall->next = cap->suspended_ccalls;
+ incall->prev = NULL;
+ if (cap->suspended_ccalls) {
+ cap->suspended_ccalls->prev = incall;
+ }
+ cap->suspended_ccalls = incall;
}
STATIC_INLINE void
recoverSuspendedTask (Capability *cap, Task *task)
{
- if (task->prev) {
- task->prev->next = task->next;
+ InCall *incall;
+
+ incall = task->incall;
+ if (incall->prev) {
+ incall->prev->next = incall->next;
} else {
- ASSERT(cap->suspended_ccalling_tasks == task);
- cap->suspended_ccalling_tasks = task->next;
+ ASSERT(cap->suspended_ccalls == incall);
+ cap->suspended_ccalls = incall->next;
}
- if (task->next) {
- task->next->prev = task->prev;
+ if (incall->next) {
+ incall->next->prev = incall->prev;
}
- task->next = task->prev = NULL;
+ incall->next = incall->prev = NULL;
}
/* ---------------------------------------------------------------------------
task = cap->running_task;
tso = cap->r.rCurrentTSO;
- postEvent(cap, EVENT_STOP_THREAD, tso->id, THREAD_SUSPENDED_FOREIGN_CALL);
- debugTrace(DEBUG_sched,
- "thread %lu did a safe foreign call",
- (unsigned long)cap->r.rCurrentTSO->id);
+ traceEventStopThread(cap, tso, THREAD_SUSPENDED_FOREIGN_CALL);
// XXX this might not be necessary --SDM
tso->what_next = ThreadRunGHC;
}
// Hand back capability
- task->suspended_tso = tso;
+ task->incall->suspended_tso = tso;
+ task->incall->suspended_cap = cap;
ACQUIRE_LOCK(&cap->lock);
RELEASE_LOCK(&cap->lock);
-#if defined(THREADED_RTS)
- /* Preparing to leave the RTS, so ensure there's a native thread/task
- waiting to take over.
- */
- debugTrace(DEBUG_sched, "thread %lu: leaving RTS", (unsigned long)tso->id);
-#endif
-
errno = saved_errno;
#if mingw32_HOST_OS
SetLastError(saved_winerror);
resumeThread (void *task_)
{
StgTSO *tso;
+ InCall *incall;
Capability *cap;
Task *task = task_;
int saved_errno;
saved_winerror = GetLastError();
#endif
- cap = task->cap;
+ incall = task->incall;
+ cap = incall->suspended_cap;
+ task->cap = cap;
+
// Wait for permission to re-enter the RTS with the result.
waitForReturnCapability(&cap,task);
// we might be on a different capability now... but if so, our
- // entry on the suspended_ccalling_tasks list will also have been
+ // entry on the suspended_ccalls list will also have been
// migrated.
// Remove the thread from the suspended list
recoverSuspendedTask(cap,task);
- tso = task->suspended_tso;
- task->suspended_tso = NULL;
+ tso = incall->suspended_tso;
+ incall->suspended_tso = NULL;
+ incall->suspended_cap = NULL;
tso->_link = END_TSO_QUEUE; // no write barrier reqd
- postEvent(cap, EVENT_RUN_THREAD, tso->id, 0);
- debugTrace(DEBUG_sched, "thread %lu: re-entering RTS", (unsigned long)tso->id);
+ traceEventRunThread(cap, tso);
if (tso->why_blocked == BlockedOnCCall) {
// avoid locking the TSO if we don't have to
- if (tso->blocked_exceptions != END_TSO_QUEUE) {
+ if (tso->blocked_exceptions != END_BLOCKED_EXCEPTIONS_QUEUE) {
awakenBlockedExceptionQueue(cap,tso);
}
tso->flags &= ~(TSO_BLOCKEX | TSO_INTERRUPTIBLE);
if (cpu == cap->no) {
appendToRunQueue(cap,tso);
} else {
- postEvent (cap, EVENT_MIGRATE_THREAD, tso->id, capabilities[cpu].no);
+ traceEventMigrateThread (cap, tso, capabilities[cpu].no);
wakeupThreadOnCapability(cap, &capabilities[cpu], tso);
}
#else
scheduleWaitThread (StgTSO* tso, /*[out]*/HaskellObj* ret, Capability *cap)
{
Task *task;
+ StgThreadID id;
// We already created/initialised the Task
task = cap->running_task;
// This TSO is now a bound thread; make the Task and TSO
// point to each other.
- tso->bound = task;
+ tso->bound = task->incall;
tso->cap = cap;
- task->tso = tso;
+ task->incall->tso = tso;
task->ret = ret;
task->stat = NoStatus;
appendToRunQueue(cap,tso);
- debugTrace(DEBUG_sched, "new bound thread (%lu)", (unsigned long)tso->id);
+ id = tso->id;
+ debugTrace(DEBUG_sched, "new bound thread (%lu)", (unsigned long)id);
cap = schedule(cap,task);
ASSERT(task->stat != NoStatus);
ASSERT_FULL_CAPABILITY_INVARIANTS(cap,task);
- debugTrace(DEBUG_sched, "bound thread (%lu) finished", (unsigned long)task->tso->id);
+ debugTrace(DEBUG_sched, "bound thread (%lu) finished", (unsigned long)id);
return cap;
}
* ------------------------------------------------------------------------- */
#if defined(THREADED_RTS)
-void OSThreadProcAttr
-workerStart(Task *task)
+void scheduleWorker (Capability *cap, Task *task)
{
- Capability *cap;
-
- // See startWorkerTask().
- ACQUIRE_LOCK(&task->lock);
- cap = task->cap;
- RELEASE_LOCK(&task->lock);
-
- if (RtsFlags.ParFlags.setAffinity) {
- setThreadAffinity(cap->no, n_capabilities);
- }
-
- // set the thread-local pointer to the Task:
- taskEnter(task);
-
// schedule() runs without a lock.
cap = schedule(cap,task);
initSparkPools();
#endif
+ RELEASE_LOCK(&sched_mutex);
+
#if defined(THREADED_RTS)
/*
* Eagerly start one worker to run each Capability, except for
for (i = 1; i < n_capabilities; i++) {
cap = &capabilities[i];
ACQUIRE_LOCK(&cap->lock);
- startWorkerTask(cap, workerStart);
+ startWorkerTask(cap);
RELEASE_LOCK(&cap->lock);
}
}
#endif
-
- RELEASE_LOCK(&sched_mutex);
}
void
if (sched_state < SCHED_SHUTTING_DOWN) {
sched_state = SCHED_INTERRUPTING;
waitForReturnCapability(&task->cap,task);
- scheduleDoGC(task->cap,task,rtsFalse);
+ scheduleDoGC(task->cap,task,rtsFalse);
+ ASSERT(task->incall->tso == NULL);
releaseCapability(task->cap);
}
sched_state = SCHED_SHUTTING_DOWN;
nat i;
for (i = 0; i < n_capabilities; i++) {
+ ASSERT(task->incall->tso == NULL);
shutdownCapability(&capabilities[i], task, wait_foreign);
}
- boundTaskExiting(task);
}
#endif
+
+ boundTaskExiting(task);
}
void
// We must grab a new Task here, because the existing Task may be
// associated with a particular Capability, and chained onto the
- // suspended_ccalling_tasks queue.
+ // suspended_ccalls queue.
task = newBoundTask();
waitForReturnCapability(&task->cap,task);
IF_DEBUG(sanity,checkTSO(tso));
- // don't allow throwTo() to modify the blocked_exceptions queue
- // while we are moving the TSO:
- lockClosure((StgClosure *)tso);
-
- if (tso->stack_size >= tso->max_stack_size && !(tso->flags & TSO_BLOCKEX)) {
+ if (tso->stack_size >= tso->max_stack_size
+ && !(tso->flags & TSO_BLOCKEX)) {
// NB. never raise a StackOverflow exception if the thread is
// inside Control.Exceptino.block. It is impractical to protect
// against stack overflow exceptions, since virtually anything
// can raise one (even 'catch'), so this is the only sensible
// thing to do here. See bug #767.
+ //
+
+ if (tso->flags & TSO_SQUEEZED) {
+ return tso;
+ }
+ // #3677: In a stack overflow situation, stack squeezing may
+ // reduce the stack size, but we don't know whether it has been
+ // reduced enough for the stack check to succeed if we try
+ // again. Fortunately stack squeezing is idempotent, so all we
+ // need to do is record whether *any* squeezing happened. If we
+ // are at the stack's absolute -K limit, and stack squeezing
+ // happened, then we try running the thread again. The
+ // TSO_SQUEEZED flag is set by threadPaused() to tell us whether
+ // squeezing happened or not.
debugTrace(DEBUG_gc,
"threadStackOverflow of TSO %ld (%p): stack too large (now %ld; max is %ld)",
tso->sp+64)));
// Send this thread the StackOverflow exception
- unlockTSO(tso);
throwToSingleThreaded(cap, tso, (StgClosure *)stackOverflow_closure);
return tso;
}
+
+ // We also want to avoid enlarging the stack if squeezing has
+ // already released some of it. However, we don't want to get into
+ // a pathalogical situation where a thread has a nearly full stack
+ // (near its current limit, but not near the absolute -K limit),
+ // keeps allocating a little bit, squeezing removes a little bit,
+ // and then it runs again. So to avoid this, if we squeezed *and*
+ // there is still less than BLOCK_SIZE_W words free, then we enlarge
+ // the stack anyway.
+ if ((tso->flags & TSO_SQUEEZED) &&
+ ((W_)(tso->sp - tso->stack) >= BLOCK_SIZE_W)) {
+ return tso;
+ }
+
/* Try to double the current stack size. If that takes us over the
* maximum stack size for this thread, then use the maximum instead
* (that is, unless we're already at or over the max size and we
"increasing stack size from %ld words to %d.",
(long)tso->stack_size, new_stack_size);
- dest = (StgTSO *)allocateLocal(cap,new_tso_size);
+ dest = (StgTSO *)allocate(cap,new_tso_size);
TICK_ALLOC_TSO(new_stack_size,0);
/* copy the TSO block and the old stack into the new area */
tso->sp = (P_)&(tso->stack[tso->stack_size]);
tso->why_blocked = NotBlocked;
- unlockTSO(dest);
- unlockTSO(tso);
-
IF_DEBUG(sanity,checkTSO(dest));
#if 0
IF_DEBUG(scheduler,printTSO(dest));
}
static StgTSO *
-threadStackUnderflow (Task *task STG_UNUSED, StgTSO *tso)
+threadStackUnderflow (Capability *cap, Task *task, StgTSO *tso)
{
bdescr *bd, *new_bd;
lnat free_w, tso_size_w;
return tso;
}
- // don't allow throwTo() to modify the blocked_exceptions queue
- // while we are moving the TSO:
- lockClosure((StgClosure *)tso);
-
// this is the number of words we'll free
free_w = round_to_mblocks(tso_size_w/2);
memcpy(new_tso,tso,TSO_STRUCT_SIZE);
new_tso->stack_size = new_bd->free - new_tso->stack;
+ // The original TSO was dirty and probably on the mutable
+ // list. The new TSO is not yet on the mutable list, so we better
+ // put it there.
+ new_tso->dirty = 0;
+ new_tso->flags &= ~TSO_LINK_DIRTY;
+ dirty_TSO(cap, new_tso);
+
debugTrace(DEBUG_sched, "thread %ld: reducing TSO size from %lu words to %lu",
(long)tso->id, tso_size_w, tso_sizeW(new_tso));
// The TSO attached to this Task may have moved, so update the
// pointer to it.
- if (task->tso == tso) {
- task->tso = new_tso;
+ if (task->incall->tso == tso) {
+ task->incall->tso = new_tso;
}
- unlockTSO(new_tso);
- unlockTSO(tso);
-
IF_DEBUG(sanity,checkTSO(new_tso));
return new_tso;
// Only create raise_closure if we need to.
if (raise_closure == NULL) {
raise_closure =
- (StgThunk *)allocateLocal(cap,sizeofW(StgThunk)+1);
+ (StgThunk *)allocate(cap,sizeofW(StgThunk)+1);
SET_HDR(raise_closure, &stg_raise_info, CCCS);
raise_closure->payload[0] = exception;
}
- UPD_IND(((StgUpdateFrame *)p)->updatee,(StgClosure *)raise_closure);
+ UPD_IND(cap, ((StgUpdateFrame *)p)->updatee,
+ (StgClosure *)raise_closure);
p = next;
continue;
case CATCH_STM_FRAME: {
StgTRecHeader *trec = tso -> trec;
- StgTRecHeader *outer = stmGetEnclosingTRec(trec);
+ StgTRecHeader *outer = trec -> enclosing_trec;
debugTrace(DEBUG_stm,
"found CATCH_STM_FRAME at %p during retry", p);
debugTrace(DEBUG_stm, "trec=%p outer=%p", trec, outer);
{
StgTSO *tso, *next;
Capability *cap;
- step *step;
+ generation *gen;
for (tso = threads; tso != END_TSO_QUEUE; tso = next) {
next = tso->global_link;
- step = Bdescr((P_)tso)->step;
- tso->global_link = step->threads;
- step->threads = tso;
+ gen = Bdescr((P_)tso)->gen;
+ tso->global_link = gen->threads;
+ gen->threads = tso;
debugTrace(DEBUG_sched, "resurrecting thread %lu", (unsigned long)tso->id);
switch (tso->why_blocked) {
case BlockedOnMVar:
- case BlockedOnException:
/* Called by GC - sched_mutex lock is currently held. */
throwToSingleThreaded(cap, tso,
- (StgClosure *)blockedOnDeadMVar_closure);
+ (StgClosure *)blockedIndefinitelyOnMVar_closure);
break;
case BlockedOnBlackHole:
throwToSingleThreaded(cap, tso,
break;
case BlockedOnSTM:
throwToSingleThreaded(cap, tso,
- (StgClosure *)blockedIndefinitely_closure);
+ (StgClosure *)blockedIndefinitelyOnSTM_closure);
break;
case NotBlocked:
/* This might happen if the thread was blocked on a black hole
*/
continue;
default:
- barf("resurrectThreads: thread blocked in a strange way");
+ barf("resurrectThreads: thread blocked in a strange way: %d",
+ tso->why_blocked);
}
}
}
-
-/* -----------------------------------------------------------------------------
- performPendingThrowTos is called after garbage collection, and
- passed a list of threads that were found to have pending throwTos
- (tso->blocked_exceptions was not empty), and were blocked.
- Normally this doesn't happen, because we would deliver the
- exception directly if the target thread is blocked, but there are
- small windows where it might occur on a multiprocessor (see
- throwTo()).
-
- NB. we must be holding all the capabilities at this point, just
- like resurrectThreads().
- -------------------------------------------------------------------------- */
-
-void
-performPendingThrowTos (StgTSO *threads)
-{
- StgTSO *tso, *next;
- Capability *cap;
- step *step;
-
- for (tso = threads; tso != END_TSO_QUEUE; tso = next) {
- next = tso->global_link;
-
- step = Bdescr((P_)tso)->step;
- tso->global_link = step->threads;
- step->threads = tso;
-
- debugTrace(DEBUG_sched, "performing blocked throwTo to thread %lu", (unsigned long)tso->id);
-
- cap = tso->cap;
- maybePerformBlockedException(cap, tso);
- }
-}