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-rw-r--r--linuxthreads/ChangeLog1
-rw-r--r--linuxthreads/Versions3
-rw-r--r--linuxthreads/semaphore.c125
-rw-r--r--linuxthreads/semaphore.h10
4 files changed, 139 insertions, 0 deletions
diff --git a/linuxthreads/ChangeLog b/linuxthreads/ChangeLog
index 2c513dc..5039a12 100644
--- a/linuxthreads/ChangeLog
+++ b/linuxthreads/ChangeLog
@@ -3,6 +3,7 @@
* semaphore.c (sem_timedwait): New function.
Patch by Carl Mailloux <carlm@oricom.ca>.
* semaphore.h: Declare sem_timedwait.
+ * Versions [libpthread] (GLIBC_2.2): Add sem_timedwait.
2000-03-26 Roland McGrath <roland@baalperazim.frob.com>
diff --git a/linuxthreads/Versions b/linuxthreads/Versions
index 1b9de67..2e3673e 100644
--- a/linuxthreads/Versions
+++ b/linuxthreads/Versions
@@ -129,5 +129,8 @@ libpthread {
__pthread_rwlock_init; __pthread_rwlock_destroy; __pthread_rwlock_rdlock;
__pthread_rwlock_tryrdlock; __pthread_rwlock_wrlock;
__pthread_rwlock_trywrlock; __pthread_rwlock_unlock;
+
+ # New functions from IEEE Std. 10003.1-200x.
+ sem_timedwait;
}
}
diff --git a/linuxthreads/semaphore.c b/linuxthreads/semaphore.c
index c4a4f6e..3344d0d 100644
--- a/linuxthreads/semaphore.c
+++ b/linuxthreads/semaphore.c
@@ -190,6 +190,131 @@ int sem_unlink(const char *name)
return -1;
}
+int sem_timedwait(sem_t *sem, const struct timespec *abstime)
+{
+ pthread_descr self = thread_self();
+ pthread_extricate_if extr;
+ int already_canceled = 0;
+ int was_signalled = 0;
+ sigjmp_buf jmpbuf;
+ sigset_t unblock;
+ sigset_t initial_mask;
+
+ __pthread_lock((struct _pthread_fastlock *) &sem->__sem_lock, self);
+ if (sem->__sem_value > 0) {
+ --sem->__sem_value;
+ __pthread_unlock((struct _pthread_fastlock *) &sem->__sem_lock);
+ return 0;
+ }
+
+ if (abstime->tv_nsec < 0 || abstime->tv_nsec >= 1000000000) {
+ /* The standard requires that if the function would block and the
+ time value is illegal, the function returns with an error. */
+ __pthread_unlock((struct _pthread_fastlock *) &sem->__sem_lock);
+ return EINVAL;
+ }
+
+ /* Set up extrication interface */
+ extr.pu_object = sem;
+ extr.pu_extricate_func = new_sem_extricate_func;
+
+ /* Register extrication interface */
+ __pthread_set_own_extricate_if(self, &extr);
+ /* Enqueue only if not already cancelled. */
+ if (!(THREAD_GETMEM(self, p_canceled)
+ && THREAD_GETMEM(self, p_cancelstate) == PTHREAD_CANCEL_ENABLE))
+ enqueue(&sem->__sem_waiting, self);
+ else
+ already_canceled = 1;
+ __pthread_unlock((struct _pthread_fastlock *) &sem->__sem_lock);
+
+ if (already_canceled) {
+ __pthread_set_own_extricate_if(self, 0);
+ pthread_exit(PTHREAD_CANCELED);
+ }
+
+ /* Set up a longjmp handler for the restart signal, unblock
+ the signal and sleep. */
+
+ if (sigsetjmp(jmpbuf, 1) == 0) {
+ THREAD_SETMEM(self, p_signal_jmp, &jmpbuf);
+ THREAD_SETMEM(self, p_signal, 0);
+ /* Unblock the restart signal */
+ sigemptyset(&unblock);
+ sigaddset(&unblock, __pthread_sig_restart);
+ sigprocmask(SIG_UNBLOCK, &unblock, &initial_mask);
+
+ while (1) {
+ struct timeval now;
+ struct timespec reltime;
+
+ /* Compute a time offset relative to now. */
+ __gettimeofday (&now, NULL);
+ reltime.tv_nsec = abstime->tv_nsec - now.tv_usec * 1000;
+ reltime.tv_sec = abstime->tv_sec - now.tv_sec;
+ if (reltime.tv_nsec < 0) {
+ reltime.tv_nsec += 1000000000;
+ reltime.tv_sec -= 1;
+ }
+
+ /* Sleep for the required duration. If woken by a signal,
+ resume waiting as required by Single Unix Specification. */
+ if (reltime.tv_sec < 0 || __libc_nanosleep(&reltime, NULL) == 0)
+ break;
+ }
+
+ /* Block the restart signal again */
+ sigprocmask(SIG_SETMASK, &initial_mask, NULL);
+ was_signalled = 0;
+ } else {
+ was_signalled = 1;
+ }
+ THREAD_SETMEM(self, p_signal_jmp, NULL);
+
+ /* Now was_signalled is true if we exited the above code
+ due to the delivery of a restart signal. In that case,
+ everything is cool. We have been removed from the queue
+ by the other thread, and consumed its signal.
+
+ Otherwise we this thread woke up spontaneously, or due to a signal other
+ than restart. The next thing to do is to try to remove the thread
+ from the queue. This may fail due to a race against another thread
+ trying to do the same. In the failed case, we know we were signalled,
+ and we may also have to consume a restart signal. */
+
+ if (!was_signalled) {
+ int was_on_queue;
+
+ /* __pthread_lock will queue back any spurious restarts that
+ may happen to it. */
+
+ __pthread_lock((struct _pthread_fastlock *)&sem->__sem_lock, self);
+ was_on_queue = remove_from_queue(&sem->__sem_waiting, self);
+ __pthread_unlock((struct _pthread_fastlock *)&sem->__sem_lock);
+
+ if (was_on_queue) {
+ __pthread_set_own_extricate_if(self, 0);
+ return ETIMEDOUT;
+ }
+
+ /* Eat the outstanding restart() from the signaller */
+ suspend(self);
+ }
+ __pthread_set_own_extricate_if(self, 0);
+
+ /* Terminate only if the wakeup came from cancellation. */
+ /* Otherwise ignore cancellation because we got the semaphore. */
+
+ if (THREAD_GETMEM(self, p_woken_by_cancel)
+ && THREAD_GETMEM(self, p_cancelstate) == PTHREAD_CANCEL_ENABLE) {
+ THREAD_SETMEM(self, p_woken_by_cancel, 0);
+ pthread_exit(PTHREAD_CANCELED);
+ }
+ /* We got the semaphore */
+ return 0;
+}
+
+
versioned_symbol (libpthread, __new_sem_init, sem_init, GLIBC_2_1);
versioned_symbol (libpthread, __new_sem_wait, sem_wait, GLIBC_2_1);
versioned_symbol (libpthread, __new_sem_trywait, sem_trywait, GLIBC_2_1);
diff --git a/linuxthreads/semaphore.h b/linuxthreads/semaphore.h
index 21a9dea..583b65e 100644
--- a/linuxthreads/semaphore.h
+++ b/linuxthreads/semaphore.h
@@ -17,6 +17,10 @@
#include <features.h>
#include <sys/types.h>
+#ifdef __USE_XOPEN2K
+# define __need_timespec
+# include <time.h>
+#endif
#ifndef _PTHREAD_DESCR_DEFINED
/* Thread descriptors. Needed for `sem_t' definition. */
@@ -66,6 +70,12 @@ extern int sem_unlink (__const char *__name) __THROW;
/* Wait for SEM being posted. */
extern int sem_wait (sem_t *__sem) __THROW;
+#ifdef __USE_XOPEN2K
+/* Similar to `sem_wait' but wait only until ABSTIME. */
+extern int sem_timedwait (sem_t *__sem, __const struct timespec *__abstime)
+ __THROW;
+#endif
+
/* Test whether SEM is posted. */
extern int sem_trywait (sem_t *__sem) __THROW;