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-rw-r--r--libpthread/linuxthreads.old/semaphore.c308
1 files changed, 308 insertions, 0 deletions
diff --git a/libpthread/linuxthreads.old/semaphore.c b/libpthread/linuxthreads.old/semaphore.c
new file mode 100644
index 000000000..5be1f5316
--- /dev/null
+++ b/libpthread/linuxthreads.old/semaphore.c
@@ -0,0 +1,308 @@
+/* Linuxthreads - a simple clone()-based implementation of Posix */
+/* threads for Linux. */
+/* Copyright (C) 1996 Xavier Leroy (Xavier.Leroy@inria.fr) */
+/* */
+/* This program is free software; you can redistribute it and/or */
+/* modify it under the terms of the GNU Library General Public License */
+/* as published by the Free Software Foundation; either version 2 */
+/* of the License, or (at your option) any later version. */
+/* */
+/* This program is distributed in the hope that it will be useful, */
+/* but WITHOUT ANY WARRANTY; without even the implied warranty of */
+/* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the */
+/* GNU Library General Public License for more details. */
+
+/* Semaphores a la POSIX 1003.1b */
+
+#include <features.h>
+#define __USE_GNU
+#include <errno.h>
+#include "pthread.h"
+#include "semaphore.h"
+#include "internals.h"
+#include "spinlock.h"
+#include "restart.h"
+#include "queue.h"
+
+int __new_sem_init(sem_t *sem, int pshared, unsigned int value)
+{
+ if (value > SEM_VALUE_MAX) {
+ errno = EINVAL;
+ return -1;
+ }
+ if (pshared) {
+ errno = ENOSYS;
+ return -1;
+ }
+ __pthread_init_lock(&sem->__sem_lock);
+ sem->__sem_value = value;
+ sem->__sem_waiting = NULL;
+ return 0;
+}
+
+/* Function called by pthread_cancel to remove the thread from
+ waiting inside __new_sem_wait. */
+
+static int new_sem_extricate_func(void *obj, pthread_descr th)
+{
+ volatile pthread_descr self = thread_self();
+ sem_t *sem = obj;
+ int did_remove = 0;
+
+ __pthread_lock(&sem->__sem_lock, self);
+ did_remove = remove_from_queue(&sem->__sem_waiting, th);
+ __pthread_unlock(&sem->__sem_lock);
+
+ return did_remove;
+}
+
+int __new_sem_wait(sem_t * sem)
+{
+ volatile pthread_descr self = thread_self();
+ pthread_extricate_if extr;
+ int already_canceled = 0;
+ int spurious_wakeup_count;
+
+ /* Set up extrication interface */
+ extr.pu_object = sem;
+ extr.pu_extricate_func = new_sem_extricate_func;
+
+ __pthread_lock(&sem->__sem_lock, self);
+ if (sem->__sem_value > 0) {
+ sem->__sem_value--;
+ __pthread_unlock(&sem->__sem_lock);
+ return 0;
+ }
+ /* Register extrication interface */
+ THREAD_SETMEM(self, p_sem_avail, 0);
+ __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(&sem->__sem_lock);
+
+ if (already_canceled) {
+ __pthread_set_own_extricate_if(self, 0);
+ pthread_exit(PTHREAD_CANCELED);
+ }
+
+ /* Wait for sem_post or cancellation, or fall through if already canceled */
+ spurious_wakeup_count = 0;
+ while (1)
+ {
+ suspend(self);
+ if (THREAD_GETMEM(self, p_sem_avail) == 0
+ && (THREAD_GETMEM(self, p_woken_by_cancel) == 0
+ || THREAD_GETMEM(self, p_cancelstate) != PTHREAD_CANCEL_ENABLE))
+ {
+ /* Count resumes that don't belong to us. */
+ spurious_wakeup_count++;
+ continue;
+ }
+ break;
+ }
+ __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;
+}
+
+int __new_sem_trywait(sem_t * sem)
+{
+ int retval;
+
+ __pthread_lock(&sem->__sem_lock, NULL);
+ if (sem->__sem_value == 0) {
+ errno = EAGAIN;
+ retval = -1;
+ } else {
+ sem->__sem_value--;
+ retval = 0;
+ }
+ __pthread_unlock(&sem->__sem_lock);
+ return retval;
+}
+
+int __new_sem_post(sem_t * sem)
+{
+ pthread_descr self = thread_self();
+ pthread_descr th;
+ struct pthread_request request;
+
+ if (THREAD_GETMEM(self, p_in_sighandler) == NULL) {
+ __pthread_lock(&sem->__sem_lock, self);
+ if (sem->__sem_waiting == NULL) {
+ if (sem->__sem_value >= SEM_VALUE_MAX) {
+ /* Overflow */
+ errno = ERANGE;
+ __pthread_unlock(&sem->__sem_lock);
+ return -1;
+ }
+ sem->__sem_value++;
+ __pthread_unlock(&sem->__sem_lock);
+ } else {
+ th = dequeue(&sem->__sem_waiting);
+ __pthread_unlock(&sem->__sem_lock);
+ th->p_sem_avail = 1;
+ WRITE_MEMORY_BARRIER();
+ restart(th);
+ }
+ } else {
+ /* If we're in signal handler, delegate post operation to
+ the thread manager. */
+ if (__pthread_manager_request < 0) {
+ if (__pthread_initialize_manager() < 0) {
+ errno = EAGAIN;
+ return -1;
+ }
+ }
+ request.req_kind = REQ_POST;
+ request.req_args.post = sem;
+ TEMP_FAILURE_RETRY(__libc_write(__pthread_manager_request,
+ (char *) &request, sizeof(request)));
+ }
+ return 0;
+}
+
+int __new_sem_getvalue(sem_t * sem, int * sval)
+{
+ *sval = sem->__sem_value;
+ return 0;
+}
+
+int __new_sem_destroy(sem_t * sem)
+{
+ if (sem->__sem_waiting != NULL) {
+ __set_errno (EBUSY);
+ return -1;
+ }
+ return 0;
+}
+
+sem_t *sem_open(const char *name, int oflag, ...)
+{
+ __set_errno (ENOSYS);
+ return SEM_FAILED;
+}
+
+int sem_close(sem_t *sem)
+{
+ __set_errno (ENOSYS);
+ return -1;
+}
+
+int sem_unlink(const char *name)
+{
+ __set_errno (ENOSYS);
+ 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 spurious_wakeup_count;
+
+ __pthread_lock(&sem->__sem_lock, self);
+ if (sem->__sem_value > 0) {
+ --sem->__sem_value;
+ __pthread_unlock(&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(&sem->__sem_lock);
+ __set_errno (EINVAL);
+ return -1;
+ }
+
+ /* Set up extrication interface */
+ extr.pu_object = sem;
+ extr.pu_extricate_func = new_sem_extricate_func;
+
+ /* Register extrication interface */
+ THREAD_SETMEM(self, p_sem_avail, 0);
+ __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(&sem->__sem_lock);
+
+ if (already_canceled) {
+ __pthread_set_own_extricate_if(self, 0);
+ pthread_exit(PTHREAD_CANCELED);
+ }
+
+ spurious_wakeup_count = 0;
+ while (1)
+ {
+ if (timedsuspend(self, abstime) == 0) {
+ int was_on_queue;
+
+ /* __pthread_lock will queue back any spurious restarts that
+ may happen to it. */
+
+ __pthread_lock(&sem->__sem_lock, self);
+ was_on_queue = remove_from_queue(&sem->__sem_waiting, self);
+ __pthread_unlock(&sem->__sem_lock);
+
+ if (was_on_queue) {
+ __pthread_set_own_extricate_if(self, 0);
+ __set_errno (ETIMEDOUT);
+ return -1;
+ }
+
+ /* Eat the outstanding restart() from the signaller */
+ suspend(self);
+ }
+
+ if (THREAD_GETMEM(self, p_sem_avail) == 0
+ && (THREAD_GETMEM(self, p_woken_by_cancel) == 0
+ || THREAD_GETMEM(self, p_cancelstate) != PTHREAD_CANCEL_ENABLE))
+ {
+ /* Count resumes that don't belong to us. */
+ spurious_wakeup_count++;
+ continue;
+ }
+ break;
+ }
+
+ __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;
+}
+
+
+weak_alias (__new_sem_init, sem_init)
+weak_alias (__new_sem_wait, sem_wait)
+weak_alias (__new_sem_trywait, sem_trywait)
+weak_alias (__new_sem_post, sem_post)
+weak_alias (__new_sem_getvalue, sem_getvalue)
+weak_alias (__new_sem_destroy, sem_destroy)
+
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