mirror of
https://sourceware.org/git/glibc.git
synced 2025-10-30 10:45:40 +03:00
81 lines
2.1 KiB
C
81 lines
2.1 KiB
C
/* POSIX spinlock implementation. SH version.
|
|
Copyright (C) 2000, 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 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>
|
|
#include "internals.h"
|
|
|
|
int
|
|
__pthread_spin_lock (pthread_spinlock_t *lock)
|
|
{
|
|
unsigned int val;
|
|
|
|
do
|
|
asm volatile ("tas.b @%1; movt %0"
|
|
: "=r" (val)
|
|
: "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 ("tas.b @%1; movt %0"
|
|
: "=r" (val)
|
|
: "r" (lock)
|
|
: "memory");
|
|
return val ? 0 : EBUSY;
|
|
}
|
|
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)
|