/* -----------------------------------------------------------------------------
- * $Id: Select.c,v 1.26 2003/02/22 06:13:41 sof Exp $
*
* (c) The GHC Team 1995-2002
*
/* #include "PosixSource.h" */
#include "Rts.h"
-#ifndef mingw32_TARGET_OS
-/* to the end */
-
#include "Schedule.h"
#include "RtsUtils.h"
#include "RtsFlags.h"
#include <errno.h>
#include <string.h>
+#ifdef HAVE_UNISTD_H
+#include <unistd.h>
+#endif
+
/* last timestamp */
nat timestamp = 0;
-#ifdef RTS_SUPPORTS_THREADS
-static rtsBool isWorkerBlockedInAwaitEvent = rtsFalse;
-static rtsBool workerWakeupPending = rtsFalse;
-static int workerWakeupPipe[2];
-static rtsBool workerWakeupInited = rtsFalse;
-#endif
-
/* There's a clever trick here to avoid problems when the time wraps
* around. Since our maximum delay is smaller than 31 bits of ticks
* (it's actually 31 bits of microseconds), we can safely check
sleeping_queue = tso->link;
tso->why_blocked = NotBlocked;
tso->link = END_TSO_QUEUE;
- IF_DEBUG(scheduler,belch("Waking up sleeping thread %d\n", tso->id));
+ IF_DEBUG(scheduler,debugBelch("Waking up sleeping thread %d\n", tso->id));
PUSH_ON_RUN_QUEUE(tso);
flag = rtsTrue;
}
tv.tv_usec = 0;
IF_DEBUG(scheduler,
- belch("scheduler: checking for threads blocked on I/O");
+ debugBelch("scheduler: checking for threads blocked on I/O");
if (wait) {
- belch(" (waiting)");
+ debugBelch(" (waiting)");
}
- belch("\n");
+ debugBelch("\n");
);
/* loop until we've woken up some threads. This loop is needed
}
}
-#ifdef RTS_SUPPORTS_THREADS
- if(!workerWakeupInited) {
- pipe(workerWakeupPipe);
- workerWakeupInited = rtsTrue;
- }
- FD_SET(workerWakeupPipe[0], &rfd);
- maxfd = workerWakeupPipe[0] > maxfd ? workerWakeupPipe[0] : maxfd;
-#endif
-
- /* Release the scheduler lock while we do the poll.
- * this means that someone might muck with the blocked_queue
- * while we do this, but it shouldn't matter:
- *
- * - another task might poll for I/O and remove one
- * or more threads from the blocked_queue.
- * - more I/O threads may be added to blocked_queue.
- * - more delayed threads may be added to blocked_queue. We'll
- * just subtract delta from their delays after the poll.
- *
- * I believe none of these cases lead to trouble --SDM.
- */
-
-#ifdef RTS_SUPPORTS_THREADS
- isWorkerBlockedInAwaitEvent = rtsTrue;
- workerWakeupPending = rtsFalse;
-#endif
- RELEASE_LOCK(&sched_mutex);
-
/* Check for any interesting events */
tv.tv_sec = min / 1000000;
unblock_all = rtsTrue;
break;
} else {
- fprintf(stderr,"%d\n", errno);
- fflush(stderr);
perror("select");
barf("select failed");
}
}
- ACQUIRE_LOCK(&sched_mutex);
-#ifdef RTS_SUPPORTS_THREADS
- isWorkerBlockedInAwaitEvent = rtsFalse;
-#endif
/* We got a signal; could be one of ours. If so, we need
* to start up the signal handler straight away, otherwise
* we could block for a long time before the signal is
* serviced.
*/
+#if defined(RTS_USER_SIGNALS)
if (signals_pending()) {
- RELEASE_LOCK(&sched_mutex); /* ToDo: kill */
startSignalHandlers();
- ACQUIRE_LOCK(&sched_mutex);
return; /* still hold the lock */
}
+#endif
/* we were interrupted, return to the scheduler immediately.
*/
if (run_queue_hd != END_TSO_QUEUE) {
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
-
-#ifdef RTS_SUPPORTS_THREADS
- isWorkerBlockedInAwaitEvent = rtsTrue;
-#endif
- RELEASE_LOCK(&sched_mutex);
}
- ACQUIRE_LOCK(&sched_mutex);
-
/* Step through the waiting queue, unblocking every thread that now has
* a file descriptor in a ready state.
*/
}
if (ready) {
- IF_DEBUG(scheduler,belch("Waking up blocked thread %d\n", tso->id));
+ IF_DEBUG(scheduler,debugBelch("Waking up blocked thread %d\n", tso->id));
tso->why_blocked = NotBlocked;
tso->link = END_TSO_QUEUE;
PUSH_ON_RUN_QUEUE(tso);
}
}
-#if defined(RTS_SUPPORTS_THREADS)
- // if we were woken up by wakeBlockedWorkerThread,
- // read the dummy byte from the pipe
- if(select_succeeded && FD_ISSET(workerWakeupPipe[0], &rfd)) {
- unsigned char dummy;
- wait = rtsFalse;
- read(workerWakeupPipe[0],&dummy,1);
- }
-#endif
} while (wait && !interrupted && run_queue_hd == END_TSO_QUEUE);
}
-
-
-#ifdef RTS_SUPPORTS_THREADS
-/* wakeBlockedWorkerThread
- *
- * If a worker thread is currently blocked within awaitEvent,
- * wake it.
- * Must be called with sched_mutex held.
- */
-void
-wakeBlockedWorkerThread()
-{
- if(isWorkerBlockedInAwaitEvent && !workerWakeupPending) {
- unsigned char dummy = 42; // Any value will do here
-
- // write something so that select() wakes up
- write(workerWakeupPipe[1],&dummy,1);
- workerWakeupPending = rtsTrue;
- }
-}
-#endif
-
-#endif /* !mingw_TARGET_OS */
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