nginx 0.5.32 *) Change: now nginx tries to set the "worker_priority", "worker_rlimit_nofile", "worker_rlimit_core", and "worker_rlimit_sigpending" without super-user privileges. *) Change: now nginx escapes space and "%" in request to a mail proxy authentication server. *) Change: now nginx escapes "%" in $memcached_key variable. *) Change: the special make target "upgrade1" was defined for online upgrade of 0.1.x versions. *) Feature: the "add_header Last-Modified ..." directive changes the "Last-Modified" response header line. *) Feature: the mail proxy supports AUTHENTICATE in IMAP mode. Thanks to Maxim Dounin. *) Feature: the mail proxy supports STARTTLS in SMTP mode. Thanks to Maxim Dounin. *) Bugfix: nginx did not close directory file on HEAD request if autoindex was used. Thanks to Arkadiusz Patyk. *) Bugfix: the "proxy_hide_header" and "fastcgi_hide_header" directives did not hide response header lines whose name was longer than 32 characters. Thanks to Manlio Perillo. *) Bugfix: active connection counter always increased if mail proxy was used. *) Bugfix: if backend returned response header only using non-buffered proxy, then nginx closed backend connection on timeout. *) Bugfix: nginx did not support several "Connection" request header lines. *) Bugfix: a charset set by the "charset" directive was not appended to the "Content-Type" header set by $r->send_http_header(). *) Bugfix: a segmentation fault might occur in worker process if /dev/poll method was used. *) Bugfix: nginx did not work on FreeBSD/sparc64. *) Bugfix: a segmentation fault occurred in worker process if invalid address was set in the "auth_http" directive. *) Bugfix: now nginx uses default listen backlog value 511 on all platforms except FreeBSD. Thanks to Jiang Hong. *) Bugfix: now Solaris sendfilev() is not used to transfer the client request body to FastCGI-server via the unix domain socket. *) Bugfix: if the same host without specified port was used as backend for HTTP and HTTPS, then nginx used only one port - 80 or 443. *) Bugfix: the "proxy_ignore_client_abort" and "fastcgi_ignore_client_abort" directives did not work; bug appeared in 0.5.13.

/*
 * 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;
#endif
} ngx_shmtx_t;


ngx_int_t ngx_shmtx_create(ngx_shmtx_t *mtx, void *addr, u_char *name);


#if (NGX_HAVE_ATOMIC_OPS)

static ngx_inline ngx_uint_t
ngx_shmtx_trylock(ngx_shmtx_t *mtx)
{
    return (*mtx->lock == 0 && ngx_atomic_cmp_set(mtx->lock, 0, ngx_pid));
}

#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_abort(err, ngx_trylock_fd_n " failed");

    return 0;
}


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_abort(err, ngx_lock_fd_n " failed");
}


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_abort(err, ngx_unlock_fd_n " failed");
}


void ngx_shmtx_destory(ngx_shmtx_t *mtx);

#endif


#endif /* _NGX_SHMTX_H_INCLUDED_ */