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/*
* Copyright (C) 2002-2004 Igor Sysoev
*/
#ifndef _NGX_ATOMIC_H_INCLUDED_
#define _NGX_ATOMIC_H_INCLUDED_
#include <ngx_config.h>
#include <ngx_core.h>
#if ( __i386__ || __amd64__ )
#define NGX_HAVE_ATOMIC_OPS 1
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;
__asm__ volatile (
NGX_SMP_LOCK
" xaddl %0, %2; "
" incl %0; "
: "=q" (old) : "0" (1), "m" (*value));
return old;
}
#if 0
static ngx_inline uint32_t ngx_atomic_dec(ngx_atomic_t *value)
{
uint32_t old;
__asm__ volatile (
NGX_SMP_LOCK
" xaddl %0, %1; "
" decl %0; "
: "=q" (old) : "0" (-1), "m" (*value));
return old;
}
#endif
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;
}
#elif ( __sparc__ )
#define NGX_HAVE_ATOMIC_OPS 1
typedef volatile uint32_t ngx_atomic_t;
static ngx_inline uint32_t ngx_atomic_inc(ngx_atomic_t *value)
{
uint32_t old, new, res;
old = *value;
for ( ;; ) {
new = old + 1;
res = new;
__asm__ volatile (
"casa [%1] 0x80, %2, %0"
: "+r" (res) : "r" (value), "r" (old));
if (res == old) {
return new;
}
old = res;
}
}
static ngx_inline uint32_t ngx_atomic_cmp_set(ngx_atomic_t *lock,
ngx_atomic_t old,
ngx_atomic_t set)
{
uint32_t res = (uint32_t) set;
__asm__ volatile (
"casa [%1] 0x80, %2, %0"
: "+r" (res) : "r" (lock), "r" (old));
return (res == old);
}
#else
#define NGX_HAVE_ATOMIC_OPS 0
typedef volatile uint32_t ngx_atomic_t;
#define ngx_atomic_inc(x) ++(*(x));
static ngx_inline uint32_t ngx_atomic_cmp_set(ngx_atomic_t *lock,
ngx_atomic_t old,
ngx_atomic_t set)
{
return 1;
}
#endif
void ngx_spinlock(ngx_atomic_t *lock, ngx_uint_t spin);
#define ngx_trylock(lock) (*(lock) == 0 && ngx_atomic_cmp_set(lock, 0, 1))
#define ngx_unlock(lock) *(lock) = 0
#endif /* _NGX_ATOMIC_H_INCLUDED_ */
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