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/*
* Copyright (C) Igor Sysoev
*/
#ifndef _NGX_SHMTX_H_INCLUDED_
#define _NGX_SHMTX_H_INCLUDED_
#include <ngx_config.h>
#include <ngx_core.h>
typedef struct {
#if (NGX_HAVE_ATOMIC_OPS)
ngx_atomic_t *lock;
#else
ngx_fd_t fd;
u_char *name;
ngx_log_t *log;
#endif
} ngx_shmtx_t;
ngx_int_t ngx_shmtx_create(ngx_shmtx_t *mtx, void *addr, u_char *name,
ngx_log_t *log);
#if (NGX_HAVE_ATOMIC_OPS)
static ngx_inline ngx_uint_t
ngx_shmtx_trylock(ngx_shmtx_t *mtx)
{
if (*mtx->lock == 0 && ngx_atomic_cmp_set(mtx->lock, 0, ngx_pid)) {
return 1;
}
return 0;
}
#define ngx_shmtx_lock(mtx) ngx_spinlock((mtx)->lock, ngx_pid, 1024)
#define ngx_shmtx_unlock(mtx) (void) ngx_atomic_cmp_set((mtx)->lock, ngx_pid, 0)
#define ngx_shmtx_destory(mtx)
#else
static ngx_inline ngx_uint_t
ngx_shmtx_trylock(ngx_shmtx_t *mtx)
{
ngx_err_t err;
err = ngx_trylock_fd(mtx->fd);
if (err == 0) {
return 1;
}
if (err == NGX_EAGAIN) {
return 0;
}
ngx_log_error(NGX_LOG_ALERT, mtx->log, err, ngx_trylock_fd_n " failed");
ngx_abort();
}
static ngx_inline void
ngx_shmtx_lock(ngx_shmtx_t *mtx)
{
ngx_err_t err;
err = ngx_lock_fd(mtx->fd);
if (err == 0) {
return;
}
ngx_log_error(NGX_LOG_ALERT, mtx->log, err, ngx_lock_fd_n " failed");
ngx_abort();
}
static ngx_inline void
ngx_shmtx_unlock(ngx_shmtx_t *mtx)
{
ngx_err_t err;
err = ngx_unlock_fd(mtx->fd);
if (err == 0) {
return;
}
ngx_log_error(NGX_LOG_ALERT, mtx->log, err, ngx_unlock_fd_n " failed");
ngx_abort();
}
void ngx_shmtx_destory(ngx_shmtx_t *mtx);
#endif
#endif /* _NGX_SHMTX_H_INCLUDED_ */
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