Mercurial > hg > nginx
view src/core/ngx_shmtx.h @ 6517:657e029bac28
Thread pools: memory barriers in task completion notifications.
The ngx_thread_pool_done object isn't volatile, and at least some
compilers assume that it is permitted to reorder modifications of
volatile and non-volatile objects. Added appropriate ngx_memory_barrier()
calls to make sure all modifications will happen before the lock is released.
Reported by Mindaugas Rasiukevicius,
http://mailman.nginx.org/pipermail/nginx-devel/2016-April/008160.html.
author | Maxim Dounin <mdounin@mdounin.ru> |
---|---|
date | Tue, 19 Apr 2016 17:18:28 +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_ */