From 696148e29889b2923f926b27f76979454676506d Mon Sep 17 00:00:00 2001 From: ShadowNinja Date: Sun, 29 Nov 2015 00:17:51 -0500 Subject: [PATCH] Fix Event implementation On non-windows platforms this just used a semaphore, which meant that multiple calls to signal() would result in wait() returning multiple times. --- src/threading/CMakeLists.txt | 1 + src/threading/event.cpp | 95 ++++++++++++++++++++++++++++++++++++ src/threading/event.h | 38 ++++++++++----- 3 files changed, 121 insertions(+), 13 deletions(-) create mode 100644 src/threading/event.cpp diff --git a/src/threading/CMakeLists.txt b/src/threading/CMakeLists.txt index f3d0efc18..5dd60ef1a 100644 --- a/src/threading/CMakeLists.txt +++ b/src/threading/CMakeLists.txt @@ -1,4 +1,5 @@ set(JTHREAD_SRCS + ${CMAKE_CURRENT_SOURCE_DIR}/event.cpp ${CMAKE_CURRENT_SOURCE_DIR}/mutex.cpp ${CMAKE_CURRENT_SOURCE_DIR}/thread.cpp ${CMAKE_CURRENT_SOURCE_DIR}/semaphore.cpp diff --git a/src/threading/event.cpp b/src/threading/event.cpp new file mode 100644 index 000000000..1c458bf1d --- /dev/null +++ b/src/threading/event.cpp @@ -0,0 +1,95 @@ +/* +This file is a part of the JThread package, which contains some object- +oriented thread wrappers for different thread implementations. + +Copyright (c) 2000-2006 Jori Liesenborgs (jori.liesenborgs@gmail.com) + +Permission is hereby granted, free of charge, to any person obtaining a +copy of this software and associated documentation files (the "Software"), +to deal in the Software without restriction, including without limitation +the rights to use, copy, modify, merge, publish, distribute, sublicense, +and/or sell copies of the Software, and to permit persons to whom the +Software is furnished to do so, subject to the following conditions: + +The above copyright notice and this permission notice shall be included in +all copies or substantial portions of the Software. + +THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR +IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, +FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL +THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER +LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING +FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER +DEALINGS IN THE SOFTWARE. +*/ + +#include "threading/event.h" + +#if defined(_WIN32) + #ifndef WIN32_LEAN_AND_MEAN + #define WIN32_LEAN_AND_MEAN + #endif + #include +#endif + + +#if __cplusplus < 201103L +Event::Event() +{ +#ifdef _WIN32 + event = CreateEvent(NULL, false, false, NULL); +#else + pthread_cond_init(&cv, NULL); + pthread_mutex_init(&mutex, NULL); +#endif +} + +Event::~Event() +{ +#ifdef _WIN32 + CloseHandle(event); +#else + pthread_cond_destroy(&cv); + pthread_mutex_destroy(&mutex); +#endif +} +#endif + + +void Event::wait() +{ +#if __cplusplus >= 201103L + MutexAutoLock lock(mutex); + while (!notified) { + cv.wait(lock); + } + notified = false; +#elif defined(_WIN32) + WaitForSingleObject(event, INFINITE); +#else + pthread_mutex_lock(&mutex); + while (!notified) { + pthread_cond_wait(&cv, &mutex); + } + notified = false; + pthread_mutex_unlock(&mutex); +#endif +} + + +void Event::signal() +{ +#if __cplusplus >= 201103L + MutexAutoLock lock(mutex); + notified = true; + cv.notify_one(); +#elif defined(_WIN32) + SetEvent(event); +#else + pthread_mutex_lock(&mutex); + notified = true; + pthread_cond_signal(&cv); + pthread_mutex_unlock(&mutex); +#endif +} + diff --git a/src/threading/event.h b/src/threading/event.h index 0105630e5..ea087e53f 100644 --- a/src/threading/event.h +++ b/src/threading/event.h @@ -26,30 +26,42 @@ DEALINGS IN THE SOFTWARE. #ifndef THREADING_EVENT_H #define THREADING_EVENT_H -#ifdef _WIN32 - #include +#if __cplusplus >= 201103L + #include + #include "threading/mutex.h" +#elif defined(_WIN32) + #include #else - #include "threading/semaphore.h" + #include #endif +/** A syncronization primitive that will wake up one waiting thread when signaled. + * Calling @c signal() multiple times before a waiting thread has had a chance + * to notice the signal will wake only one thread. Additionally, if no threads + * are waiting on the event when it is signaled, the next call to @c wait() + * will return (almost) immediately. + */ class Event { public: -#ifdef _WIN32 - Event() { event = CreateEvent(NULL, false, false, NULL); } - ~Event() { CloseHandle(event); } - void wait() { WaitForSingleObject(event, INFINITE); } - void signal() { SetEvent(event); } -#else - void wait() { sem.wait(); } - void signal() { sem.post(); } +#if __cplusplus < 201103L + Event(); + ~Event(); #endif + void wait(); + void signal(); private: -#ifdef _WIN32 +#if __cplusplus >= 201103L + std::condition_variable cv; + Mutex mutex; + bool notified; +#elif defined(_WIN32) HANDLE event; #else - Semaphore sem; + pthread_cond_t cv; + pthread_mutex_t mutex; + bool notified; #endif };