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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/posix
parent93ba48b6534f44c41f5739505dc9943d760a1867 (diff)
parentf115339ad63bfb0005bc3d1ebfb05e1a0aecc0db (diff)
Merge branch 'upstream-merged' of git.debian.org:/git/pkg-hurd/hurd into upstream-merged
Diffstat (limited to 'libpthread/sysdeps/posix')
-rw-r--r--libpthread/sysdeps/posix/pt-spin.c54
1 files changed, 54 insertions, 0 deletions
diff --git a/libpthread/sysdeps/posix/pt-spin.c b/libpthread/sysdeps/posix/pt-spin.c
new file mode 100644
index 00000000..cb809c64
--- /dev/null
+++ b/libpthread/sysdeps/posix/pt-spin.c
@@ -0,0 +1,54 @@
+/* Spin locks.
+ Copyright (C) 2000, 2004, 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 <sched.h>
+
+/* The default for single processor machines; don't spin, it's
+ pointless. */
+#ifndef __PTHREAD_SPIN_COUNT
+# define __PTHREAD_SPIN_COUNT 1
+#endif
+
+/* The number of times to spin while trying to lock a spin lock object
+ before yielding the processor. */
+int __pthread_spin_count = __PTHREAD_SPIN_COUNT;
+
+
+/* Lock the spin lock object LOCK. If the lock is held by another
+ thread spin until it becomes available. */
+int
+_pthread_spin_lock (__pthread_spinlock_t *lock)
+{
+ int i;
+
+ while (1)
+ {
+ for (i = 0; i < __pthread_spin_count; i++)
+ {
+ if (__pthread_spin_trylock (lock) == 0)
+ return 0;
+ }
+
+ __sched_yield ();
+ }
+}
+
+weak_alias (_pthread_spin_lock, pthread_spin_lock);
+weak_alias (_pthread_spin_lock, __pthread_spin_lock);