diff options
Diffstat (limited to 'libpthread/linuxthreads/sysdeps/arm/pspinlock.c')
-rw-r--r-- | libpthread/linuxthreads/sysdeps/arm/pspinlock.c | 81 |
1 files changed, 81 insertions, 0 deletions
diff --git a/libpthread/linuxthreads/sysdeps/arm/pspinlock.c b/libpthread/linuxthreads/sysdeps/arm/pspinlock.c new file mode 100644 index 000000000..691085270 --- /dev/null +++ b/libpthread/linuxthreads/sysdeps/arm/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 Lesser General Public License as + published by the Free Software Foundation; either version 2.1 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 + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; see the file COPYING.LIB. If + not, see <http://www.gnu.org/licenses/>. */ + +#include <errno.h> +#include <pthread.h> +#include "internals.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) |