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authorSamuel Thibault <samuel.thibault@ens-lyon.org>2012-02-19 05:50:33 +0100
committerSamuel Thibault <samuel.thibault@ens-lyon.org>2012-02-19 05:50:33 +0100
commit6b2e5e0d91823c2a6ce5a5cb12ae3d00b82adae7 (patch)
tree30abf5fa5e54f2a079e53228083cf4d230efc102 /libpthread/sysdeps/generic/pt-mutex-unlock.c
parent93ba48b6534f44c41f5739505dc9943d760a1867 (diff)
parentf115339ad63bfb0005bc3d1ebfb05e1a0aecc0db (diff)
Merge branch 'upstream-merged' of git.debian.org:/git/pkg-hurd/hurd into upstream-merged
Diffstat (limited to 'libpthread/sysdeps/generic/pt-mutex-unlock.c')
-rw-r--r--libpthread/sysdeps/generic/pt-mutex-unlock.c108
1 files changed, 108 insertions, 0 deletions
diff --git a/libpthread/sysdeps/generic/pt-mutex-unlock.c b/libpthread/sysdeps/generic/pt-mutex-unlock.c
new file mode 100644
index 00000000..09d70f8f
--- /dev/null
+++ b/libpthread/sysdeps/generic/pt-mutex-unlock.c
@@ -0,0 +1,108 @@
+/* Unlock a mutex. Generic version.
+ Copyright (C) 2000, 2002, 2008 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 <pt-internal.h>
+
+#define LOSE do { * (int *) 0 = 0; } while (1)
+
+/* Unlock MUTEX, rescheduling a waiting thread. */
+int
+__pthread_mutex_unlock (pthread_mutex_t *mutex)
+{
+ struct __pthread *wakeup;
+ const struct __pthread_mutexattr *attr = mutex->attr;
+
+ if (attr == __PTHREAD_ERRORCHECK_MUTEXATTR)
+ attr = &__pthread_errorcheck_mutexattr;
+ if (attr == __PTHREAD_RECURSIVE_MUTEXATTR)
+ attr = &__pthread_recursive_mutexattr;
+
+ __pthread_spin_lock (&mutex->__lock);
+
+ if (! attr || attr->mutex_type == PTHREAD_MUTEX_NORMAL)
+ {
+#if defined(ALWAYS_TRACK_MUTEX_OWNER)
+# ifndef NDEBUG
+ if (_pthread_self ())
+ {
+ assert (mutex->owner);
+ assert (mutex->owner == _pthread_self ());
+ mutex->owner = NULL;
+ }
+# endif
+#endif
+ }
+ else
+ switch (attr->mutex_type)
+ {
+ case PTHREAD_MUTEX_ERRORCHECK:
+ case PTHREAD_MUTEX_RECURSIVE:
+ if (mutex->owner != _pthread_self ())
+ {
+ __pthread_spin_unlock (&mutex->__lock);
+ return EPERM;
+ }
+
+ if (attr->mutex_type == PTHREAD_MUTEX_RECURSIVE)
+ if (--mutex->locks > 0)
+ {
+ __pthread_spin_unlock (&mutex->__lock);
+ return 0;
+ }
+
+ mutex->owner = 0;
+ break;
+
+ default:
+ LOSE;
+ }
+
+
+ if (mutex->__queue == NULL)
+ {
+ __pthread_spin_unlock (&mutex->__held);
+ __pthread_spin_unlock (&mutex->__lock);
+ return 0;
+ }
+
+ wakeup = mutex->__queue;
+ __pthread_dequeue (wakeup);
+
+#ifndef NDEBUG
+# if !defined (ALWAYS_TRACK_MUTEX_OWNER)
+ if (attr && attr->mutex_type != PTHREAD_MUTEX_NORMAL)
+# endif
+ {
+ mutex->owner = wakeup;
+ }
+#endif
+
+ /* We do not unlock MUTEX->held: we are transferring the ownership
+ to the thread that we are waking up. */
+
+ __pthread_spin_unlock (&mutex->__lock);
+ __pthread_wakeup (wakeup);
+
+ return 0;
+}
+
+strong_alias (__pthread_mutex_unlock, _pthread_mutex_unlock);
+strong_alias (__pthread_mutex_unlock, pthread_mutex_unlock);