view src/http/ngx_http_busy_lock.h @ 3440:88741ec7731a stable-0.7

merge r3294, r3305: Fix a bug introduced in r2032: After a child process has read a terminate message from a channel, the process tries to read the channel again. The kernel (at least FreeBSD) may preempt the process and sends a SIGIO signal to a master process. The master process sends a new terminate message, the kernel switches again to the the child process, and the child process reads the messages instead of an EAGAIN error. And this may repeat over and over. Being that the child process can not exit the cycle and test the termination flag set by the message handler. The fix disallow the master process to send a new terminate message on SIGIO signal reception. It may send the message only on SIGALARM signal.
author Igor Sysoev <igor@sysoev.ru>
date Mon, 01 Feb 2010 15:49:36 +0000
parents 4c43e25d11ea
children d620f497c50f
line wrap: on
line source


/*
 * Copyright (C) Igor Sysoev
 */


#ifndef _NGX_HTTP_BUSY_LOCK_H_INCLUDED_
#define _NGX_HTTP_BUSY_LOCK_H_INCLUDED_


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


typedef struct {
    u_char             *md5_mask;
    char               *md5;
    int                 cacheable;

    int                 busy;
    int                 max_busy;

    int                 waiting;
    int                 max_waiting;

    time_t              timeout;

    ngx_event_mutex_t  *mutex;
} ngx_http_busy_lock_t;


typedef struct {
    time_t         time;
    ngx_event_t   *event;
    void         (*event_handler)(ngx_event_t *ev);
    u_char        *md5;
    int            slot;
} ngx_http_busy_lock_ctx_t;


int ngx_http_busy_lock(ngx_http_busy_lock_t *bl, ngx_http_busy_lock_ctx_t *bc);
int ngx_http_busy_lock_cacheable(ngx_http_busy_lock_t *bl,
                                 ngx_http_busy_lock_ctx_t *bc, int lock);
void ngx_http_busy_unlock(ngx_http_busy_lock_t *bl,
                          ngx_http_busy_lock_ctx_t *bc);

char *ngx_http_set_busy_lock_slot(ngx_conf_t *cf, ngx_command_t *cmd,
                                  void *conf);


#endif /* _NGX_HTTP_BUSY_LOCK_H_INCLUDED_ */