Mercurial > hg > nginx
view src/core/ngx_md5.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 | d620f497c50f |
children | 9eefb38f0005 |
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/* * Copyright (C) Igor Sysoev * Copyright (C) Nginx, Inc. */ #ifndef _NGX_MD5_H_INCLUDED_ #define _NGX_MD5_H_INCLUDED_ #include <ngx_config.h> #include <ngx_core.h> #if (NGX_HAVE_MD5) #if (NGX_HAVE_OPENSSL_MD5_H) #include <openssl/md5.h> #else #include <md5.h> #endif typedef MD5_CTX ngx_md5_t; #if (NGX_OPENSSL_MD5) #define ngx_md5_init MD5_Init #define ngx_md5_update MD5_Update #define ngx_md5_final MD5_Final #else #define ngx_md5_init MD5Init #define ngx_md5_update MD5Update #define ngx_md5_final MD5Final #endif #else /* !NGX_HAVE_MD5 */ typedef struct { uint64_t bytes; uint32_t a, b, c, d; u_char buffer[64]; } ngx_md5_t; void ngx_md5_init(ngx_md5_t *ctx); void ngx_md5_update(ngx_md5_t *ctx, const void *data, size_t size); void ngx_md5_final(u_char result[16], ngx_md5_t *ctx); #endif #endif /* _NGX_MD5_H_INCLUDED_ */