nginx 1.1.11 *) Feature: the "so_keepalive" parameter of the "listen" directive. Thanks to Vsevolod Stakhov. *) Feature: the "if_not_empty" parameter of the "fastcgi/scgi/uwsgi_param" directives. *) Feature: the $https variable. *) Feature: the "proxy_redirect" directive supports variables in the first parameter. *) Feature: the "proxy_redirect" directive supports regular expressions. *) Bugfix: the $sent_http_cache_control variable might contain a wrong value if the "expires" directive was used. Thanks to Yichun Zhang. *) Bugfix: the "read_ahead" directive might not work combined with "try_files" and "open_file_cache". *) Bugfix: a segmentation fault might occur in a worker process if small time was used in the "inactive" parameter of the "proxy_cache_path" directive. *) Bugfix: responses from cache might hang.

/*
 * Copyright (C) Igor Sysoev
 */


#ifndef _NGX_SHMTX_H_INCLUDED_
#define _NGX_SHMTX_H_INCLUDED_


#include <ngx_config.h>
#include <ngx_core.h>


typedef struct {
    ngx_atomic_t   lock;
#if (NGX_HAVE_POSIX_SEM)
    ngx_atomic_t   wait;
#endif
} ngx_shmtx_sh_t;


typedef struct {
#if (NGX_HAVE_ATOMIC_OPS)
    ngx_atomic_t  *lock;
#if (NGX_HAVE_POSIX_SEM)
    ngx_atomic_t  *wait;
    ngx_uint_t     semaphore;
    sem_t          sem;
#endif
#else
    ngx_fd_t       fd;
    u_char        *name;
#endif
    ngx_uint_t     spin;
} ngx_shmtx_t;


ngx_int_t ngx_shmtx_create(ngx_shmtx_t *mtx, ngx_shmtx_sh_t *addr,
    u_char *name);
void ngx_shmtx_destory(ngx_shmtx_t *mtx);
ngx_uint_t ngx_shmtx_trylock(ngx_shmtx_t *mtx);
void ngx_shmtx_lock(ngx_shmtx_t *mtx);
void ngx_shmtx_unlock(ngx_shmtx_t *mtx);
ngx_uint_t ngx_shmtx_force_unlock(ngx_shmtx_t *mtx, ngx_pid_t pid);


#endif /* _NGX_SHMTX_H_INCLUDED_ */