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authorNeal H. Walfield <neal@gnu.org>2002-10-10 23:05:06 +0000
committerNeal H. Walfield <neal@gnu.org>2002-10-10 23:05:06 +0000
commit51c55d85632d43aa362b625ae519d00d559f9e5c (patch)
tree2efb73388ae81c46c1475bcb3133b879a0176bf1 /sysdeps/generic/pt-mutex-trylock.c
Import libpthread.
Diffstat (limited to 'sysdeps/generic/pt-mutex-trylock.c')
-rw-r--r--sysdeps/generic/pt-mutex-trylock.c89
1 files changed, 89 insertions, 0 deletions
diff --git a/sysdeps/generic/pt-mutex-trylock.c b/sysdeps/generic/pt-mutex-trylock.c
new file mode 100644
index 0000000..b3c3fe3
--- /dev/null
+++ b/sysdeps/generic/pt-mutex-trylock.c
@@ -0,0 +1,89 @@
+/* Try to Lock a mutex. Generic version.
+ Copyright (C) 2002 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)
+
+/* Lock MUTEX, block if we can't get it. */
+int
+__pthread_mutex_trylock (struct __pthread_mutex *mutex)
+{
+ int err;
+ struct __pthread *self;
+
+ __pthread_spin_lock (&mutex->__lock);
+ if (__pthread_spin_trylock (&mutex->__held) == 0)
+ /* Acquired the lock. */
+ {
+ if (mutex->attr)
+ switch (mutex->attr->mutex_type)
+ {
+ case PTHREAD_MUTEX_NORMAL:
+ break;
+
+ case PTHREAD_MUTEX_RECURSIVE:
+ mutex->locks = 1;
+ case PTHREAD_MUTEX_ERRORCHECK:
+ mutex->owner = _pthread_self ();
+ break;
+
+ default:
+ LOSE;
+ }
+
+ __pthread_spin_unlock (&mutex->__lock);
+ return 0;
+ }
+
+ err = EBUSY;
+
+ if (mutex->attr)
+ {
+ self = _pthread_self ();
+ switch (mutex->attr->mutex_type)
+ {
+ case PTHREAD_MUTEX_NORMAL:
+ break;
+
+ case PTHREAD_MUTEX_ERRORCHECK:
+ if (mutex->owner == self)
+ err = EDEADLK;
+ break;
+
+ case PTHREAD_MUTEX_RECURSIVE:
+ if (mutex->owner == self)
+ {
+ mutex->locks ++;
+ err = 0;
+ }
+ break;
+
+ default:
+ LOSE;
+ }
+ }
+
+ return err;
+}
+
+weak_alias (__pthread_mutex_trylock, _pthread_mutex_trylock);
+weak_alias (__pthread_mutex_trylock, pthread_mutex_trylock);