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- /* POSIX spinlock implementation. SPARC32 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"
- /* This implementation is similar to the one used in the Linux kernel. */
- int
- __pthread_spin_lock (pthread_spinlock_t *lock)
- {
- __asm__ __volatile__
- ("1: ldstub [%0], %%g2\n"
- " orcc %%g2, 0x0, %%g0\n"
- " bne,a 2f\n"
- " ldub [%0], %%g2\n"
- ".subsection 2\n"
- "2: orcc %%g2, 0x0, %%g0\n"
- " bne,a 2b\n"
- " ldub [%0], %%g2\n"
- " b,a 1b\n"
- ".previous"
- : /* no outputs */
- : "r" (lock)
- : "g2", "memory", "cc");
- return 0;
- }
- weak_alias (__pthread_spin_lock, pthread_spin_lock)
- int
- __pthread_spin_trylock (pthread_spinlock_t *lock)
- {
- int result;
- __asm__ __volatile__
- ("ldstub [%1], %0"
- : "=r" (result)
- : "r" (lock)
- : "memory");
- return result == 0 ? 0 : EBUSY;
- }
- weak_alias (__pthread_spin_trylock, pthread_spin_trylock)
- int
- __pthread_spin_unlock (pthread_spinlock_t *lock)
- {
- *lock = 0;
- return 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. */
- *lock = 0;
- return 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)
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