view src/core/ngx_shmtx.h @ 6768:d9c180fcbfa7 stable-1.10

Event pipe: do not set file's thread_handler if not needed. This fixes a problem with aio threads and sendfile with aio_write switched off, as observed with range requests after fc72784b1f52 (1.9.13). Potential problems with sendfile in threads were previously described in 9fd738b85fad, and this seems to be one of them. The problem occurred as file's thread_handler was set to NULL by event pipe code after a sendfile thread task was scheduled. As a result, no sendfile completion code was executed, and the same buffer was additionally sent using non-threaded sendfile. Fix is to avoid modifying file's thread_handler if aio_write is switched off. Note that with "aio_write on" it is still possible that sendfile will use thread_handler as set by event pipe. This is believed to be safe though, as handlers used are compatible.
author Maxim Dounin <mdounin@mdounin.ru>
date Thu, 01 Sep 2016 20:05:23 +0300
parents 512c741fa841
children
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/*
 * Copyright (C) Igor Sysoev
 * Copyright (C) Nginx, Inc.
 */


#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_destroy(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_ */