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simgear/simgear/threads/SGThread.cxx

403 lines
9.0 KiB
C++

// SGThread - Simple pthread class wrappers.
//
// Written by Bernie Bright, started April 2001.
//
// Copyright (C) 2001 Bernard Bright - bbright@bigpond.net.au
// Copyright (C) 2011 Mathias Froehlich
//
// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License as
// published by the Free Software Foundation; either version 2 of the
// License, or (at your option) any later version.
//
// This program 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
// General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
//
#ifdef HAVE_CONFIG_H
# include <simgear_config.h>
#endif
#include <simgear/compiler.h>
#include <simgear/debug/logstream.hxx>
#include "SGThread.hxx"
#include <thread>
#include <mutex>
#include <condition_variable>
#include <chrono>
#include <climits>
struct SGThread::PrivateData {
PrivateData()
{
}
~PrivateData()
{
// If we are still having a started thread and nobody waited,
// now detach ...
if (!_started)
return;
_thread.detach();
}
static void *start_routine(void* data)
{
SGThread* thread = reinterpret_cast<SGThread*>(data);
thread->run();
return 0;
}
bool start(SGThread& thread)
{
if (_started)
return false;
try {
_thread = std::thread(start_routine, &thread);
} catch (std::runtime_error &ex) {
return false;
}
_started = true;
return true;
}
void join()
{
if (!_started)
return;
_thread.join();
_started = false;
}
std::thread _thread;
bool _started = false;
};
long SGThread::current( void )
{
#ifdef _WIN32
return (long)GetCurrentThreadId();
#else
return (long)pthread_self();
#endif
}
#if _WIN32
/////////////////////////////////////////////////////////////////////////////
/// win32 threads
/////////////////////////////////////////////////////////////////////////////
#include <list>
#include <windows.h>
struct SGWaitCondition::PrivateData {
~PrivateData(void)
{
// The waiters list should be empty anyway
_mutex.lock();
while (!_pool.empty()) {
CloseHandle(_pool.front());
_pool.pop_front();
}
_mutex.unlock();
}
void signal(void)
{
_mutex.lock();
if (!_waiters.empty())
SetEvent(_waiters.back());
_mutex.unlock();
}
void broadcast(void)
{
_mutex.lock();
for (std::list<HANDLE>::iterator i = _waiters.begin(); i != _waiters.end(); ++i)
SetEvent(*i);
_mutex.unlock();
}
bool wait(std::mutex& externalMutex, DWORD msec)
{
_mutex.lock();
if (_pool.empty())
_waiters.push_front(CreateEvent(NULL, FALSE, FALSE, NULL));
else
_waiters.splice(_waiters.begin(), _pool, _pool.begin());
std::list<HANDLE>::iterator i = _waiters.begin();
_mutex.unlock();
externalMutex.unlock();
DWORD result = WaitForSingleObject(*i, msec);
externalMutex.lock();
_mutex.lock();
if (result != WAIT_OBJECT_0)
result = WaitForSingleObject(*i, 0);
_pool.splice(_pool.begin(), _waiters, i);
_mutex.unlock();
return result == WAIT_OBJECT_0;
}
void wait(std::mutex& externalMutex)
{
wait(externalMutex, INFINITE);
}
// Protect the list of waiters
std::mutex _mutex;
std::list<HANDLE> _waiters;
std::list<HANDLE> _pool;
};
#else
/////////////////////////////////////////////////////////////////////////////
/// posix threads
/////////////////////////////////////////////////////////////////////////////
#include <pthread.h>
#include <cassert>
#include <cerrno>
#include <sys/time.h>
struct SGWaitCondition::PrivateData {
PrivateData(void)
{
int err = pthread_cond_init(&_condition, NULL);
assert(err == 0);
(void)err;
}
~PrivateData(void)
{
int err = pthread_cond_destroy(&_condition);
assert(err == 0);
(void)err;
}
void signal(void)
{
int err = pthread_cond_signal(&_condition);
assert(err == 0);
(void)err;
}
void broadcast(void)
{
int err = pthread_cond_broadcast(&_condition);
assert(err == 0);
(void)err;
}
void wait(std::mutex& mutex)
{
int err = pthread_cond_wait(&_condition, mutex.native_handle());
assert(err == 0);
(void)err;
}
bool wait(std::mutex& mutex, unsigned msec)
{
struct timespec ts;
#ifdef HAVE_CLOCK_GETTIME
if (0 != clock_gettime(CLOCK_REALTIME, &ts))
return false;
#else
struct timeval tv;
if (0 != gettimeofday(&tv, NULL))
return false;
ts.tv_sec = tv.tv_sec;
ts.tv_nsec = tv.tv_usec * 1000;
#endif
ts.tv_nsec += 1000000*(msec % 1000);
if (1000000000 <= ts.tv_nsec) {
ts.tv_nsec -= 1000000000;
ts.tv_sec += 1;
}
ts.tv_sec += msec / 1000;
int evalue = pthread_cond_timedwait(&_condition, mutex.native_handle(), &ts);
if (evalue == 0)
return true;
assert(evalue == ETIMEDOUT);
return false;
}
pthread_cond_t _condition;
};
#endif
SGThread::SGThread() :
_privateData(new PrivateData)
{
}
SGThread::~SGThread()
{
delete _privateData;
_privateData = 0;
}
bool
SGThread::start()
{
return _privateData->start(*this);
}
void
SGThread::join()
{
_privateData->join();
}
SGWaitCondition::SGWaitCondition() :
_privateData(new PrivateData)
{
}
SGWaitCondition::~SGWaitCondition()
{
delete _privateData;
_privateData = 0;
}
void
SGWaitCondition::wait(std::mutex& mutex)
{
_privateData->wait(mutex);
}
bool
SGWaitCondition::wait(std::mutex& mutex, unsigned msec)
{
return _privateData->wait(mutex, msec);
}
void
SGWaitCondition::signal()
{
_privateData->signal();
}
void
SGWaitCondition::broadcast()
{
_privateData->broadcast();
}
SGExclusiveThread::SGExclusiveThread() :
_started(false), _terminated(false), last_await_time(0),
dataReady(false), complete(true), process_ran(false), process_running(false)
{
}
SGExclusiveThread::~SGExclusiveThread()
{
}
void SGExclusiveThread::release() {
std::unique_lock<std::mutex> lck(mutex_);
if (!complete) {
SG_LOG(SG_NASAL, SG_ALERT, "[SGExclusiveThread] not finished - skipping");
return;
}
if (!complete.exchange(false))
SG_LOG(SG_NASAL, SG_ALERT, "[SGExclusiveThread] concurrent failure (2)");
if (dataReady.exchange(true))
SG_LOG(SG_NASAL, SG_ALERT, "[SGExclusiveThread] concurrent failure (1)");
condVar.notify_one();
}
void SGExclusiveThread::wait() {
std::unique_lock<std::mutex> lck(mutex_);
if (!dataReady)
{
do
{
condVar.wait(lck);
} while (!dataReady);
}
}
void SGExclusiveThread::clearAwaitCompletionTime() {
last_await_time = 0;
}
void SGExclusiveThread::awaitCompletion() {
timestamp.stamp();
std::unique_lock<std::mutex> lck(Cmutex_);
if (!complete)
{
do {
CcondVar.wait(lck);
} while (!complete.load());
}
if (process_ran) {
last_await_time = timestamp.elapsedUSec();
process_ran = 0;
}
}
void SGExclusiveThread::setCompletion() {
std::unique_lock<std::mutex> lck(Cmutex_);
if (!dataReady.exchange(false))
SG_LOG(SG_NASAL, SG_ALERT, "[SGExclusiveThread] atomic operation on dataReady failed (5)\n");
if (complete.exchange(true))
SG_LOG(SG_NASAL, SG_ALERT, "[SGExclusiveThread] atomic operation on complete failed (5)\n");
CcondVar.notify_one();
}
void SGExclusiveThread::run()
{
process_running = true;
while (!_terminated) {
wait();
process_ran = process();
setCompletion();
}
process_running = false;
_terminated = false;
_started = false;
}
void SGExclusiveThread::terminate() {
_terminated = true;
release();
join();
}
bool SGExclusiveThread::stop()
{
return true;
}
void SGExclusiveThread::ensure_running()
{
if (!_started)
{
_started = true;
start();
}
}
bool SGExclusiveThread::is_running()
{
return process_running;
}