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Diffstat (limited to 'libpthread/sysdeps/generic/pt-rwlock-timedwrlock.c')
-rw-r--r--libpthread/sysdeps/generic/pt-rwlock-timedwrlock.c95
1 files changed, 95 insertions, 0 deletions
diff --git a/libpthread/sysdeps/generic/pt-rwlock-timedwrlock.c b/libpthread/sysdeps/generic/pt-rwlock-timedwrlock.c
new file mode 100644
index 00000000..04eab51f
--- /dev/null
+++ b/libpthread/sysdeps/generic/pt-rwlock-timedwrlock.c
@@ -0,0 +1,95 @@
+/* Acquire a rwlock for writing. Generic version.
+ Copyright (C) 2002, 2005 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ The GNU C Library 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.
+
+ The GNU C Library 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.
+
+ You should have received a copy of the GNU Library General Public
+ License along with the GNU C Library; see the file COPYING.LIB. If not,
+ write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ Boston, MA 02111-1307, USA. */
+
+#include <pthread.h>
+#include <assert.h>
+
+#include <pt-internal.h>
+
+/* Acquire RWLOCK for writing blocking until *ABSTIME if we cannot get
+ it. As a special GNU extension, if ABSTIME is NULL then the wait
+ shall not time out. */
+int
+__pthread_rwlock_timedwrlock_internal (struct __pthread_rwlock *rwlock,
+ const struct timespec *abstime)
+{
+ struct __pthread *self;
+
+ __pthread_spin_lock (&rwlock->__lock);
+ if (__pthread_spin_trylock (&rwlock->__held) == 0)
+ /* Successfully acquired the lock. */
+ {
+ assert (rwlock->readerqueue == 0);
+ assert (rwlock->writerqueue == 0);
+ assert (rwlock->readers == 0);
+
+ __pthread_spin_unlock (&rwlock->__lock);
+ return 0;
+ }
+
+ /* The lock is busy. */
+
+ if (abstime && (abstime->tv_nsec < 0 || abstime->tv_nsec >= 1000000000))
+ return EINVAL;
+
+ self = _pthread_self ();
+
+ /* Add ourselves to the queue. */
+ __pthread_enqueue (&rwlock->writerqueue, self);
+ __pthread_spin_unlock (&rwlock->__lock);
+
+ /* Block the thread. */
+ if (abstime)
+ {
+ error_t err;
+
+ err = __pthread_timedblock (self, abstime);
+ if (err)
+ /* We timed out. We may need to disconnect ourself from the
+ waiter queue.
+
+ FIXME: What do we do if we get a wakeup message before we
+ disconnect ourself? It may remain until the next time we
+ block. */
+ {
+ assert (err == ETIMEDOUT);
+
+ __pthread_spin_lock (&rwlock->__lock);
+ if (self->prevp)
+ /* Disconnect ourself. */
+ __pthread_dequeue (self);
+ __pthread_spin_unlock (&rwlock->__lock);
+
+ return err;
+ }
+ }
+ else
+ __pthread_block (self);
+
+ assert (rwlock->readers == 0);
+
+ return 0;
+}
+
+int
+pthread_rwlock_timedwrlock (struct __pthread_rwlock *rwlock,
+ const struct timespec *abstime)
+{
+ return __pthread_rwlock_timedwrlock_internal (rwlock, abstime);
+}