+#if !defined(THREADED_RTS) /* to the end */
/*
* Wait/check for external events. Periodically, the
* Scheduler checks for the completion of external operations,
*/
#include "Rts.h"
#include "Schedule.h"
+#include "AwaitEvent.h"
#include <windows.h>
#include "win32/AsyncIO.h"
-#if defined(RTS_SUPPORTS_THREADS)
-#include "Capability.h"
-#endif
+
+// Used to avoid calling abandonRequestWait() if we don't need to.
+// Protected by sched_mutex.
+static nat workerWaitingForRequests = 0;
void
awaitEvent(rtsBool wait)
{
- RELEASE_LOCK(&sched_mutex);
- do {
- /* Try to de-queue completed IO requests */
- if (!awaitRequests(wait)) {
- return;
- }
- ACQUIRE_LOCK(&sched_mutex);
- /* we were interrupted, return to the scheduler immediately.
- */
- if (interrupted) {
- return; /* still hold the lock */
- }
+ int ret;
- /* If new runnable threads have arrived, stop waiting for
- * I/O and run them.
+ do {
+ /* Try to de-queue completed IO requests
*/
- if (run_queue_hd != END_TSO_QUEUE) {
+ workerWaitingForRequests = 1;
+ ret = awaitRequests(wait);
+ workerWaitingForRequests = 0;
+ if (!ret) {
return; /* still hold the lock */
}
-#ifdef RTS_SUPPORTS_THREADS
- /* If another worker thread wants to take over,
- * return to the scheduler
- */
- if (needToYieldToReturningWorker()) {
- return; /* still hold the lock */
- }
-#endif
- RELEASE_LOCK(&sched_mutex);
- } while (wait && !interrupted && run_queue_hd == END_TSO_QUEUE);
-}
+ // Return to the scheduler if:
+ //
+ // - we were interrupted
+ // - new threads have arrived
-#ifdef RTS_SUPPORTS_THREADS
-void
-wakeBlockedWorkerThread()
-{
- abandonRequestWait();
+ } while (wait
+ && !interrupted
+ && emptyRunQueue(&MainCapability)
+ );
}
#endif
-