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/*
* libjingle
* Copyright 2004--2008, Google Inc.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
* 3. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
* EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
* OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
* OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
* ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "talk/base/event.h"
#if defined(WIN32)
#include <windows.h>
#elif defined(POSIX)
#include <pthread.h>
#include <sys/time.h>
#include <time.h>
#else
#error "Must define either WIN32 or POSIX."
#endif
namespace talk_base {
#if defined(WIN32)
Event::Event(bool manual_reset, bool initially_signaled)
: is_manual_reset_(manual_reset),
is_initially_signaled_(initially_signaled),
event_handle_(NULL) {
}
bool Event::EnsureInitialized() {
if (event_handle_ == NULL) {
event_handle_ = ::CreateEvent(NULL, // Security attributes.
is_manual_reset_,
is_initially_signaled_,
NULL); // Name.
}
return (event_handle_ != NULL);
}
Event::~Event() {
if (event_handle_ != NULL) {
CloseHandle(event_handle_);
event_handle_ = NULL;
}
}
bool Event::Set() {
if (!EnsureInitialized())
return false;
SetEvent(event_handle_);
return true;
}
bool Event::Reset() {
if (!EnsureInitialized())
return false;
ResetEvent(event_handle_);
return true;
}
bool Event::Wait(int cms) {
DWORD ms = (cms == kForever)? INFINITE : cms;
if (!EnsureInitialized())
return false;
else
return (WaitForSingleObject(event_handle_, ms) == WAIT_OBJECT_0);
}
#elif defined(POSIX)
Event::Event(bool manual_reset, bool initially_signaled)
: is_manual_reset_(manual_reset),
event_status_(initially_signaled),
event_mutex_initialized_(false),
event_cond_initialized_(false) {
}
bool Event::EnsureInitialized() {
if (!event_mutex_initialized_) {
if (pthread_mutex_init(&event_mutex_, NULL) == 0)
event_mutex_initialized_ = true;
}
if (!event_cond_initialized_) {
if (pthread_cond_init(&event_cond_, NULL) == 0)
event_cond_initialized_ = true;
}
return (event_mutex_initialized_ && event_cond_initialized_);
}
Event::~Event() {
if (event_mutex_initialized_) {
pthread_mutex_destroy(&event_mutex_);
event_mutex_initialized_ = false;
}
if (event_cond_initialized_) {
pthread_cond_destroy(&event_cond_);
event_cond_initialized_ = false;
}
}
bool Event::Set() {
if (!EnsureInitialized())
return false;
pthread_mutex_lock(&event_mutex_);
event_status_ = true;
pthread_cond_broadcast(&event_cond_);
pthread_mutex_unlock(&event_mutex_);
return true;
}
bool Event::Reset() {
if (!EnsureInitialized())
return false;
pthread_mutex_lock(&event_mutex_);
event_status_ = false;
pthread_mutex_unlock(&event_mutex_);
return true;
}
bool Event::Wait(int cms) {
if (!EnsureInitialized())
return false;
pthread_mutex_lock(&event_mutex_);
int error = 0;
if (cms != kForever) {
// Converting from seconds and microseconds (1e-6) plus
// milliseconds (1e-3) to seconds and nanoseconds (1e-9).
struct timeval tv;
gettimeofday(&tv, NULL);
struct timespec ts;
ts.tv_sec = tv.tv_sec + (cms / 1000);
ts.tv_nsec = tv.tv_usec * 1000 + (cms % 1000) * 1000000;
// Handle overflow.
if (ts.tv_nsec >= 1000000000) {
ts.tv_sec++;
ts.tv_nsec -= 1000000000;
}
while (!event_status_ && error == 0)
error = pthread_cond_timedwait(&event_cond_, &event_mutex_, &ts);
} else {
while (!event_status_ && error == 0)
error = pthread_cond_wait(&event_cond_, &event_mutex_);
}
// NOTE(liulk): Exactly one thread will auto-reset this event. All
// the other threads will think it's unsignaled. This seems to be
// consistent with auto-reset events in WIN32.
if (error == 0 && !is_manual_reset_)
event_status_ = false;
pthread_mutex_unlock(&event_mutex_);
return (error == 0);
}
#endif
} // namespace talk_base
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