Mercurial > hg > nginx
view src/event/ngx_event_posted.c @ 4576:876e6b0814a5
Fixed signed integer overflows in timer code (ticket #145).
Integer overflow is undefined behaviour in C and this indeed caused
problems on Solaris/SPARC (at least in some cases). Fix is to
subtract unsigned integers instead, and then cast result to a signed
one, which is implementation-defined behaviour and used to work.
Strictly speaking, we should compare (unsigned) result with the maximum
value of the corresponding signed integer type instead, this will be
defined behaviour. This will require much more changes though, and
considered to be overkill for now.
author | Maxim Dounin <mdounin@mdounin.ru> |
---|---|
date | Fri, 06 Apr 2012 23:46:09 +0000 |
parents | d620f497c50f |
children | 3377f9459e99 |
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/* * Copyright (C) Igor Sysoev * Copyright (C) Nginx, Inc. */ #include <ngx_config.h> #include <ngx_core.h> #include <ngx_event.h> ngx_thread_volatile ngx_event_t *ngx_posted_accept_events; ngx_thread_volatile ngx_event_t *ngx_posted_events; #if (NGX_THREADS) ngx_mutex_t *ngx_posted_events_mutex; #endif void ngx_event_process_posted(ngx_cycle_t *cycle, ngx_thread_volatile ngx_event_t **posted) { ngx_event_t *ev; for ( ;; ) { ev = (ngx_event_t *) *posted; ngx_log_debug1(NGX_LOG_DEBUG_EVENT, cycle->log, 0, "posted event %p", ev); if (ev == NULL) { return; } ngx_delete_posted_event(ev); ev->handler(ev); } } #if (NGX_THREADS) && !(NGX_WIN32) void ngx_wakeup_worker_thread(ngx_cycle_t *cycle) { ngx_int_t i; #if 0 ngx_uint_t busy; ngx_event_t *ev; busy = 1; if (ngx_mutex_lock(ngx_posted_events_mutex) == NGX_ERROR) { return; } for (ev = (ngx_event_t *) ngx_posted_events; ev; ev = ev->next) { if (*(ev->lock) == 0) { busy = 0; break; } } ngx_mutex_unlock(ngx_posted_events_mutex); if (busy) { return; } #endif for (i = 0; i < ngx_threads_n; i++) { if (ngx_threads[i].state == NGX_THREAD_FREE) { ngx_cond_signal(ngx_threads[i].cv); return; } } } ngx_int_t ngx_event_thread_process_posted(ngx_cycle_t *cycle) { ngx_event_t *ev; for ( ;; ) { ev = (ngx_event_t *) ngx_posted_events; for ( ;; ) { ngx_log_debug1(NGX_LOG_DEBUG_EVENT, cycle->log, 0, "posted event %p", ev); if (ev == NULL) { return NGX_OK; } if (ngx_trylock(ev->lock) == 0) { ngx_log_debug1(NGX_LOG_DEBUG_EVENT, cycle->log, 0, "posted event %p is busy", ev); ev = ev->next; continue; } if (ev->lock != ev->own_lock) { if (*(ev->own_lock)) { ngx_log_error(NGX_LOG_ALERT, cycle->log, 0, "the own lock of the posted event %p is busy", ev); ngx_unlock(ev->lock); ev = ev->next; continue; } *(ev->own_lock) = 1; } ngx_delete_posted_event(ev); ev->locked = 1; ev->ready |= ev->posted_ready; ev->timedout |= ev->posted_timedout; ev->pending_eof |= ev->posted_eof; #if (NGX_HAVE_KQUEUE) ev->kq_errno |= ev->posted_errno; #endif if (ev->posted_available) { ev->available = ev->posted_available; } ev->posted_ready = 0; ev->posted_timedout = 0; ev->posted_eof = 0; #if (NGX_HAVE_KQUEUE) ev->posted_errno = 0; #endif ev->posted_available = 0; ngx_mutex_unlock(ngx_posted_events_mutex); ev->handler(ev); ngx_mutex_lock(ngx_posted_events_mutex); if (ev->locked) { ngx_unlock(ev->lock); if (ev->lock != ev->own_lock) { ngx_unlock(ev->own_lock); } } ngx_log_debug1(NGX_LOG_DEBUG_EVENT, cycle->log, 0, "posted event %p is done", ev); break; } } } #else void ngx_wakeup_worker_thread(ngx_cycle_t *cycle) { } #endif