Mercurial > hg > nginx
view src/core/ngx_radix_tree.h @ 6080:4296627f385a stable-1.6
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 | 3be3de31d7dd |
children |
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/* * Copyright (C) Igor Sysoev * Copyright (C) Nginx, Inc. */ #ifndef _NGX_RADIX_TREE_H_INCLUDED_ #define _NGX_RADIX_TREE_H_INCLUDED_ #include <ngx_config.h> #include <ngx_core.h> #define NGX_RADIX_NO_VALUE (uintptr_t) -1 typedef struct ngx_radix_node_s ngx_radix_node_t; struct ngx_radix_node_s { ngx_radix_node_t *right; ngx_radix_node_t *left; ngx_radix_node_t *parent; uintptr_t value; }; typedef struct { ngx_radix_node_t *root; ngx_pool_t *pool; ngx_radix_node_t *free; char *start; size_t size; } ngx_radix_tree_t; ngx_radix_tree_t *ngx_radix_tree_create(ngx_pool_t *pool, ngx_int_t preallocate); ngx_int_t ngx_radix32tree_insert(ngx_radix_tree_t *tree, uint32_t key, uint32_t mask, uintptr_t value); ngx_int_t ngx_radix32tree_delete(ngx_radix_tree_t *tree, uint32_t key, uint32_t mask); uintptr_t ngx_radix32tree_find(ngx_radix_tree_t *tree, uint32_t key); #if (NGX_HAVE_INET6) ngx_int_t ngx_radix128tree_insert(ngx_radix_tree_t *tree, u_char *key, u_char *mask, uintptr_t value); ngx_int_t ngx_radix128tree_delete(ngx_radix_tree_t *tree, u_char *key, u_char *mask); uintptr_t ngx_radix128tree_find(ngx_radix_tree_t *tree, u_char *key); #endif #endif /* _NGX_RADIX_TREE_H_INCLUDED_ */