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91 lines
1.6 KiB
C
91 lines
1.6 KiB
C
#ifndef _NGX_ATOMIC_H_INCLUDED_
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#define _NGX_ATOMIC_H_INCLUDED_
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#include <ngx_config.h>
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#include <ngx_core.h>
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#if ( __i386__ || __amd64__ )
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typedef volatile uint32_t ngx_atomic_t;
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#if (NGX_SMP)
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#define NGX_SMP_LOCK "lock;"
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#else
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#define NGX_SMP_LOCK
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#endif
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static ngx_inline uint32_t ngx_atomic_inc(ngx_atomic_t *value)
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{
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uint32_t old;
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__asm__ volatile (
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NGX_SMP_LOCK
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" xaddl %0, %2; "
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" incl %0; "
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: "=q" (old) : "0" (1), "m" (*value));
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return old;
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}
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static ngx_inline uint32_t ngx_atomic_dec(ngx_atomic_t *value)
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{
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uint32_t old;
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__asm__ volatile (
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NGX_SMP_LOCK
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" xaddl %0, %1; "
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" decl %0; "
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: "=q" (old) : "0" (-1), "m" (*value));
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return old;
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}
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static ngx_inline uint32_t ngx_atomic_cmp_set(ngx_atomic_t *lock,
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ngx_atomic_t old,
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ngx_atomic_t set)
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{
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uint32_t res;
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__asm__ volatile (
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NGX_SMP_LOCK
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" cmpxchgl %3, %1; "
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" setz %%al; "
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" movzbl %%al, %0; "
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: "=a" (res) : "m" (*lock), "a" (old), "q" (set));
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return res;
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}
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#else
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typedef volatile uint32_t ngx_atomic_t;
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/* STUB */
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#define ngx_atomic_inc(x) (*(x))++;
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#define ngx_atomic_dec(x) (*(x))--;
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#define ngx_atomic_cmp_set(lock, old, set) 1
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/**/
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#endif
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void ngx_spinlock(ngx_atomic_t *lock, ngx_uint_t spin);
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#define ngx_trylock(lock) (*(lock) == 0 && ngx_atomic_cmp_set(lock, 0, 1))
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#define ngx_unlock(lock) *(lock) = 0
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#endif /* _NGX_ATOMIC_H_INCLUDED_ */
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