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authorUlrich Drepper <drepper@redhat.com>2000-05-25 05:28:08 +0000
committerUlrich Drepper <drepper@redhat.com>2000-05-25 05:28:08 +0000
commit438c13509424f0530157284474cecbe153e2f03b (patch)
tree4635dbcb05ea7e77fb255dcb63ff304cd2c45e14 /sysdeps
parent4decd16ab5ff514ed18d0abb7aefb86fa693b66d (diff)
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Linux/Arm spinlock implementation.
Diffstat (limited to 'sysdeps')
-rw-r--r--sysdeps/arm/linuxthreads/pspinlock.c81
1 files changed, 81 insertions, 0 deletions
diff --git a/sysdeps/arm/linuxthreads/pspinlock.c b/sysdeps/arm/linuxthreads/pspinlock.c
new file mode 100644
index 0000000000..a56881adfd
--- /dev/null
+++ b/sysdeps/arm/linuxthreads/pspinlock.c
@@ -0,0 +1,81 @@
+/* POSIX spinlock implementation. Arm version.
+ Copyright (C) 2000 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 <errno.h>
+#include <pthread.h>
+
+
+int
+__pthread_spin_lock (pthread_spinlock_t *lock)
+{
+ unsigned int val;
+
+ do
+ asm volatile ("swp %0, %1, [%2]"
+ : "=r" (val)
+ : "0" (1), "r" (lock)
+ : "memory");
+ while (val != 0);
+
+ return 0;
+}
+weak_alias (__pthread_spin_lock, pthread_spin_lock)
+
+
+int
+__pthread_spin_trylock (pthread_spinlock_t *lock)
+{
+ unsigned int val;
+
+ asm volatile ("swp %0, %1, [%2]"
+ : "=r" (val)
+ : "0" (1), "r" (lock)
+ : "memory");
+
+ return val ? EBUSY : 0;
+}
+weak_alias (__pthread_spin_trylock, pthread_spin_trylock)
+
+
+int
+__pthread_spin_unlock (pthread_spinlock_t *lock)
+{
+ return *lock = 0;
+}
+weak_alias (__pthread_spin_unlock, pthread_spin_unlock)
+
+
+int
+__pthread_spin_init (pthread_spinlock_t *lock, int pshared)
+{
+ /* We can ignore the `pshared' parameter. Since we are busy-waiting
+ all processes which can access the memory location `lock' points
+ to can use the spinlock. */
+ return *lock = 0;
+}
+weak_alias (__pthread_spin_init, pthread_spin_init)
+
+
+int
+__pthread_spin_destroy (pthread_spinlock_t *lock)
+{
+ /* Nothing to do. */
+ return 0;
+}
+weak_alias (__pthread_spin_destroy, pthread_spin_destroy)