view src/os/unix/ngx_setproctitle.h @ 5970:74edc0ccf27a

Core: fixed a race resulting in extra sem_post()'s. The mtx->wait counter was not decremented if we were able to obtain the lock right after incrementing it. This resulted in unneeded sem_post() calls, eventually leading to EOVERFLOW errors being logged, "sem_post() failed while wake shmtx (75: Value too large for defined data type)". To close the race, mtx->wait is now decremented if we obtain the lock right after incrementing it in ngx_shmtx_lock(). The result can become -1 if a concurrent ngx_shmtx_unlock() decrements mtx->wait before the added code does. However, that only leads to one extra iteration in the next call of ngx_shmtx_lock().
author Roman Arutyunyan <arut@nginx.com>
date Wed, 04 Feb 2015 16:22:43 +0300
parents 16013b71feed
children
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/*
 * Copyright (C) Igor Sysoev
 * Copyright (C) Nginx, Inc.
 */


#ifndef _NGX_SETPROCTITLE_H_INCLUDED_
#define _NGX_SETPROCTITLE_H_INCLUDED_


#if (NGX_HAVE_SETPROCTITLE)

/* FreeBSD, NetBSD, OpenBSD */

#define ngx_init_setproctitle(log) NGX_OK
#define ngx_setproctitle(title)    setproctitle("%s", title)


#else /* !NGX_HAVE_SETPROCTITLE */

#if !defined NGX_SETPROCTITLE_USES_ENV

#if (NGX_SOLARIS)

#define NGX_SETPROCTITLE_USES_ENV  1
#define NGX_SETPROCTITLE_PAD       ' '

ngx_int_t ngx_init_setproctitle(ngx_log_t *log);
void ngx_setproctitle(char *title);

#elif (NGX_LINUX) || (NGX_DARWIN)

#define NGX_SETPROCTITLE_USES_ENV  1
#define NGX_SETPROCTITLE_PAD       '\0'

ngx_int_t ngx_init_setproctitle(ngx_log_t *log);
void ngx_setproctitle(char *title);

#else

#define ngx_init_setproctitle(log) NGX_OK
#define ngx_setproctitle(title)

#endif /* OSes */

#endif /* NGX_SETPROCTITLE_USES_ENV */

#endif /* NGX_HAVE_SETPROCTITLE */


#endif /* _NGX_SETPROCTITLE_H_INCLUDED_ */