Mercurial > hg > nginx
view src/core/ngx_murmurhash.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 | 709d7d24239d |
children |
line wrap: on
line source
/* * Copyright (C) Igor Sysoev * Copyright (C) Nginx, Inc. */ #ifndef _NGX_MURMURHASH_H_INCLUDED_ #define _NGX_MURMURHASH_H_INCLUDED_ #include <ngx_config.h> #include <ngx_core.h> uint32_t ngx_murmur_hash2(u_char *data, size_t len); #endif /* _NGX_MURMURHASH_H_INCLUDED_ */