/* Copyright (c) 2007-2016 Contributors as noted in the AUTHORS file This file is part of libzmq, the ZeroMQ core engine in C++. libzmq is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License (LGPL) as published by the Free Software Foundation; either version 3 of the License, or (at your option) any later version. As a special exception, the Contributors give you permission to link this library with independent modules to produce an executable, regardless of the license terms of these independent modules, and to copy and distribute the resulting executable under terms of your choice, provided that you also meet, for each linked independent module, the terms and conditions of the license of that module. An independent module is a module which is not derived from or based on this library. If you modify this library, you must extend this exception to your version of the library. libzmq is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details. You should have received a copy of the GNU Lesser General Public License along with this program. If not, see <http://www.gnu.org/licenses/>. */ #ifndef __ZMQ_CONDITON_VARIABLE_HPP_INCLUDED__ #define __ZMQ_CONDITON_VARIABLE_HPP_INCLUDED__ #include "clock.hpp" #include "err.hpp" #include "mutex.hpp" // Condition variable class encapsulates OS mutex in a platform-independent way. #ifdef ZMQ_HAVE_WINDOWS #include "windows.hpp" #if defined(_MSC_VER) #if _MSC_VER >= 1800 #define _SUPPORT_CONDITION_VARIABLE 1 #else #define _SUPPORT_CONDITION_VARIABLE 0 #endif #else #if _cplusplus >= 201103L #define _SUPPORT_CONDITION_VARIABLE 1 #else #define _SUPPORT_CONDITION_VARIABLE 0 #endif #endif // Condition variable is supported from Windows Vista only, to use condition variable define _WIN32_WINNT to 0x0600 #if _WIN32_WINNT < 0x0600 && !_SUPPORT_CONDITION_VARIABLE namespace zmq { class condition_variable_t { public: inline condition_variable_t () { zmq_assert (false); } inline ~condition_variable_t () {} inline int wait (mutex_t *mutex_, int timeout_) { zmq_assert (false); return -1; } inline void broadcast () { zmq_assert (false); } private: // Disable copy construction and assignment. condition_variable_t (const condition_variable_t &); void operator= (const condition_variable_t &); }; } #else #if _SUPPORT_CONDITION_VARIABLE || defined(ZMQ_HAVE_WINDOWS_TARGET_XP) #include <condition_variable> #include <mutex> #endif namespace zmq { #if !defined(ZMQ_HAVE_WINDOWS_TARGET_XP) && _WIN32_WINNT >= 0x0600 class condition_variable_t { public: inline condition_variable_t () { InitializeConditionVariable (&cv); } inline ~condition_variable_t () {} inline int wait (mutex_t *mutex_, int timeout_) { int rc = SleepConditionVariableCS (&cv, mutex_->get_cs (), timeout_); if (rc != 0) return 0; rc = GetLastError (); if (rc != ERROR_TIMEOUT) win_assert (rc); errno = EAGAIN; return -1; } inline void broadcast () { WakeAllConditionVariable (&cv); } private: CONDITION_VARIABLE cv; // Disable copy construction and assignment. condition_variable_t (const condition_variable_t &); void operator= (const condition_variable_t &); }; #else class condition_variable_t { public: inline condition_variable_t () {} inline ~condition_variable_t () {} inline int wait (mutex_t *mutex_, int timeout_) { std::unique_lock<std::mutex> lck (mtx); // lock mtx mutex_->unlock (); // unlock mutex_ int res = 0; if (timeout_ == -1) { cv.wait ( lck); // unlock mtx and wait cv.notify_all(), lock mtx after cv.notify_all() } else if (cv.wait_for (lck, std::chrono::milliseconds (timeout_)) == std::cv_status::timeout) { // time expired errno = EAGAIN; res = -1; } lck.unlock (); // unlock mtx mutex_->lock (); // lock mutex_ return res; } inline void broadcast () { std::unique_lock<std::mutex> lck (mtx); // lock mtx cv.notify_all (); } private: std::condition_variable cv; std::mutex mtx; // Disable copy construction and assignment. condition_variable_t (const condition_variable_t &); void operator= (const condition_variable_t &); }; #endif } #endif #elif defined ZMQ_HAVE_VXWORKS #include <sysLib.h> namespace zmq { class condition_variable_t { public: inline condition_variable_t () {} inline ~condition_variable_t () { scoped_lock_t l (m_listenersMutex); for (size_t i = 0; i < m_listeners.size (); i++) { semDelete (m_listeners[i]); } } inline int wait (mutex_t *mutex_, int timeout_) { //Atomically releases lock, blocks the current executing thread, //and adds it to the list of threads waiting on *this. The thread //will be unblocked when broadcast() is executed. //It may also be unblocked spuriously. When unblocked, regardless //of the reason, lock is reacquired and wait exits. SEM_ID sem = semBCreate (SEM_Q_PRIORITY, SEM_EMPTY); { scoped_lock_t l (m_listenersMutex); m_listeners.push_back (sem); } mutex_->unlock (); int rc; if (timeout_ < 0) rc = semTake (sem, WAIT_FOREVER); else { int ticksPerSec = sysClkRateGet (); int timeoutTicks = (timeout_ * ticksPerSec) / 1000 + 1; rc = semTake (sem, timeoutTicks); } { scoped_lock_t l (m_listenersMutex); // remove sem from listeners for (size_t i = 0; i < m_listeners.size (); i++) { if (m_listeners[i] == sem) { m_listeners.erase (m_listeners.begin () + i); break; } } semDelete (sem); } mutex_->lock (); if (rc == 0) return 0; if (rc == S_objLib_OBJ_TIMEOUT) { errno = EAGAIN; return -1; } return -1; } inline void broadcast () { scoped_lock_t l (m_listenersMutex); for (size_t i = 0; i < m_listeners.size (); i++) { semGive (m_listeners[i]); } } private: mutex_t m_listenersMutex; std::vector<SEM_ID> m_listeners; // Disable copy construction and assignment. condition_variable_t (const condition_variable_t &); const condition_variable_t &operator= (const condition_variable_t &); }; } #else #include <pthread.h> #if defined(__ANDROID_API__) && __ANDROID_API__ < 21 #define ANDROID_LEGACY extern "C" int pthread_cond_timedwait_monotonic_np (pthread_cond_t *, pthread_mutex_t *, const struct timespec *); #endif namespace zmq { class condition_variable_t { public: inline condition_variable_t () { pthread_condattr_t attr; pthread_condattr_init (&attr); #if !defined(ZMQ_HAVE_OSX) && !defined(ANDROID_LEGACY) pthread_condattr_setclock (&attr, CLOCK_MONOTONIC); #endif int rc = pthread_cond_init (&cond, &attr); posix_assert (rc); } inline ~condition_variable_t () { int rc = pthread_cond_destroy (&cond); posix_assert (rc); } inline int wait (mutex_t *mutex_, int timeout_) { int rc; if (timeout_ != -1) { struct timespec timeout; #ifdef ZMQ_HAVE_OSX timeout.tv_sec = 0; timeout.tv_nsec = 0; #else clock_gettime (CLOCK_MONOTONIC, &timeout); #endif timeout.tv_sec += timeout_ / 1000; timeout.tv_nsec += (timeout_ % 1000) * 1000000; if (timeout.tv_nsec > 1000000000) { timeout.tv_sec++; timeout.tv_nsec -= 1000000000; } #ifdef ZMQ_HAVE_OSX rc = pthread_cond_timedwait_relative_np ( &cond, mutex_->get_mutex (), &timeout); #elif defined(ANDROID_LEGACY) rc = pthread_cond_timedwait_monotonic_np ( &cond, mutex_->get_mutex (), &timeout); #else rc = pthread_cond_timedwait (&cond, mutex_->get_mutex (), &timeout); #endif } else rc = pthread_cond_wait (&cond, mutex_->get_mutex ()); if (rc == 0) return 0; if (rc == ETIMEDOUT) { errno = EAGAIN; return -1; } posix_assert (rc); return -1; } inline void broadcast () { int rc = pthread_cond_broadcast (&cond); posix_assert (rc); } private: pthread_cond_t cond; // Disable copy construction and assignment. condition_variable_t (const condition_variable_t &); const condition_variable_t &operator= (const condition_variable_t &); }; } #endif #endif