Mercurial > hg > nginx
view auto/init @ 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 | 85dea406e18f |
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# Copyright (C) Igor Sysoev # Copyright (C) Nginx, Inc. NGX_MAKEFILE=$NGX_OBJS/Makefile NGX_MODULES_C=$NGX_OBJS/ngx_modules.c NGX_AUTO_HEADERS_H=$NGX_OBJS/ngx_auto_headers.h NGX_AUTO_CONFIG_H=$NGX_OBJS/ngx_auto_config.h NGX_AUTOTEST=$NGX_OBJS/autotest NGX_AUTOCONF_ERR=$NGX_OBJS/autoconf.err # STUBs NGX_ERR=$NGX_OBJS/autoconf.err MAKEFILE=$NGX_OBJS/Makefile NGX_PCH= NGX_USE_PCH= # check the echo's "-n" option and "\c" capability if echo "test\c" | grep c >/dev/null; then if echo -n test | grep n >/dev/null; then ngx_n= ngx_c= else ngx_n=-n ngx_c= fi else ngx_n= ngx_c='\c' fi # create Makefile cat << END > Makefile default: build clean: rm -rf Makefile $NGX_OBJS END