nginx/src/core/ngx_atomic.h
2004-03-29 17:43:58 +00:00

86 lines
1.4 KiB
C

#ifndef _NGX_ATOMIC_H_INCLUDED_
#define _NGX_ATOMIC_H_INCLUDED_
#include <ngx_config.h>
#include <ngx_core.h>
#if ( __i386__ || __amd64__ )
typedef volatile uint32_t ngx_atomic_t;
#if (NGX_SMP)
#define NGX_SMP_LOCK "lock"
#else
#define NGX_SMP_LOCK
#endif
static ngx_inline uint32_t ngx_atomic_inc(ngx_atomic_t *value)
{
uint32_t old;
old = 1;
__asm__ volatile (
NGX_SMP_LOCK
" xaddl %0, %1; "
: "=q" (old) : "m" (*value));
return old;
}
static ngx_inline uint32_t ngx_atomic_dec(ngx_atomic_t *value)
{
uint32_t old;
old = (uint32_t) -1;
__asm__ volatile (
NGX_SMP_LOCK
" xaddl %0, %1; "
: "=q" (old) : "m" (*value));
return old;
}
static ngx_inline uint32_t ngx_atomic_cmp_set(ngx_atomic_t *lock,
ngx_atomic_t old,
ngx_atomic_t set)
{
uint32_t res;
__asm__ volatile (
NGX_SMP_LOCK
" cmpxchgl %3, %1; "
" setz %%al; "
" movzbl %%al, %0; "
: "+a" (res) : "m" (*lock), "a" (old), "q" (set));
return res;
}
#else
typedef volatile uint32_t ngx_atomic_t;
/* STUB */
#define ngx_atomic_inc(x) (*(x))++;
#define ngx_atomic_dec(x) (*(x))--;
#define ngx_atomic_cmp_set(lock, old, set) 1;
/**/
#endif
#endif /* _NGX_ATOMIC_H_INCLUDED_ */