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author | Jakub Jelinek <jakub@redhat.com> | 2007-07-12 18:26:36 +0000 |
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committer | Jakub Jelinek <jakub@redhat.com> | 2007-07-12 18:26:36 +0000 |
commit | 0ecb606cb6cf65de1d9fc8a919bceb4be476c602 (patch) | |
tree | 2ea1f8305970753e4a657acb2ccc15ca3eec8e2c /linuxthreads/sysdeps/x86_64/pspinlock.c | |
parent | 7d58530341304d403a6626d7f7a1913165fe2f32 (diff) | |
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2.5-18.1
Diffstat (limited to 'linuxthreads/sysdeps/x86_64/pspinlock.c')
-rw-r--r-- | linuxthreads/sysdeps/x86_64/pspinlock.c | 97 |
1 files changed, 0 insertions, 97 deletions
diff --git a/linuxthreads/sysdeps/x86_64/pspinlock.c b/linuxthreads/sysdeps/x86_64/pspinlock.c deleted file mode 100644 index e1b2a66841..0000000000 --- a/linuxthreads/sysdeps/x86_64/pspinlock.c +++ /dev/null @@ -1,97 +0,0 @@ -/* POSIX spinlock implementation. x86-64 version. - Copyright (C) 2001 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; 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> -#include "internals.h" - -/* This implementation is similar to the one used in the Linux kernel. - But the kernel is byte instructions for the memory access. This is - faster but unusable here. The problem is that only 128 - threads/processes could use the spinlock at the same time. If (by - a design error in the program) a thread/process would hold the - spinlock for a time long enough to accumulate 128 waiting - processes, the next one will find a positive value in the spinlock - and assume it is unlocked. We cannot accept that. */ - -int -__pthread_spin_lock (pthread_spinlock_t *lock) -{ - asm volatile - ("\n" - "1:\n\t" - "lock; decl %0\n\t" - "js 2f\n\t" - ".section .text.spinlock,\"ax\"\n" - "2:\n\t" - "cmpl $0,%0\n\t" - "rep; nop\n\t" - "jle 2b\n\t" - "jmp 1b\n\t" - ".previous" - : "=m" (*lock)); - return 0; -} -weak_alias (__pthread_spin_lock, pthread_spin_lock) - - -int -__pthread_spin_trylock (pthread_spinlock_t *lock) -{ - int oldval; - - asm volatile - ("xchgl %0,%1" - : "=r" (oldval), "=m" (*lock) - : "0" (0)); - return oldval > 0 ? 0 : EBUSY; -} -weak_alias (__pthread_spin_trylock, pthread_spin_trylock) - - -int -__pthread_spin_unlock (pthread_spinlock_t *lock) -{ - asm volatile - ("movl $1,%0" - : "=m" (*lock)); - 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 = 1; - 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) |