http://stxxl.sourceforge.net
<dementiev@mpi-sb.mpg.de>
http://www.boost.org/LICENSE_1_0.txt
#ifndef STXXL_SWITCH_HEADER
#define STXXL_SWITCH_HEADER
#ifdef STXXL_BOOST_THREADS
#include <boost/thread/mutex.hpp>
#include <boost/thread/condition.hpp>
#else
#include <pthread.h>
#endif
#include <stxxl/bits/noncopyable.h>
#include <stxxl/bits/common/error_handling.h>
__STXXL_BEGIN_NAMESPACE
class onoff_switch : private noncopyable
{
#ifdef STXXL_BOOST_THREADS
boost::mutex mutex;
boost::condition cond;
#else
pthread_mutex_t mutex;
pthread_cond_t cond;
#endif
bool _on;
public:
onoff_switch(bool flag = false) : _on(flag)
{
#ifndef STXXL_BOOST_THREADS
check_pthread_call(pthread_mutex_init(&mutex, NULL));
check_pthread_call(pthread_cond_init(&cond, NULL));
#endif
}
~onoff_switch()
{
#ifndef STXXL_BOOST_THREADS
int res = pthread_mutex_trylock(&mutex);
if (res == 0 || res == EBUSY) {
check_pthread_call(pthread_mutex_unlock(&mutex));
} else
stxxl_function_error(resource_error);
check_pthread_call(pthread_mutex_destroy(&mutex));
check_pthread_call(pthread_cond_destroy(&cond));
#endif
}
void on()
{
#ifdef STXXL_BOOST_THREADS
boost::mutex::scoped_lock Lock(mutex);
_on = true;
Lock.unlock();
cond.notify_one();
#else
check_pthread_call(pthread_mutex_lock(&mutex));
_on = true;
check_pthread_call(pthread_mutex_unlock(&mutex));
check_pthread_call(pthread_cond_signal(&cond));
#endif
}
void off()
{
#ifdef STXXL_BOOST_THREADS
boost::mutex::scoped_lock Lock(mutex);
_on = false;
Lock.unlock();
cond.notify_one();
#else
check_pthread_call(pthread_mutex_lock(&mutex));
_on = false;
check_pthread_call(pthread_mutex_unlock(&mutex));
check_pthread_call(pthread_cond_signal(&cond));
#endif
}
void wait_for_on()
{
#ifdef STXXL_BOOST_THREADS
boost::mutex::scoped_lock Lock(mutex);
if (!_on)
cond.wait(Lock);
#else
check_pthread_call(pthread_mutex_lock(&mutex));
if (!_on)
check_pthread_call(pthread_cond_wait(&cond, &mutex));
check_pthread_call(pthread_mutex_unlock(&mutex));
#endif
}
void wait_for_off()
{
#ifdef STXXL_BOOST_THREADS
boost::mutex::scoped_lock Lock(mutex);
if (_on)
cond.wait(Lock);
#else
check_pthread_call(pthread_mutex_lock(&mutex));
if (_on)
check_pthread_call(pthread_cond_wait(&cond, &mutex));
check_pthread_call(pthread_mutex_unlock(&mutex));
#endif
}
bool is_on()
{
#ifdef STXXL_BOOST_THREADS
boost::mutex::scoped_lock Lock(mutex);
return _on;
#else
bool res;
check_pthread_call(pthread_mutex_lock(&mutex));
res = _on;
check_pthread_call(pthread_mutex_unlock(&mutex));
return res;
#endif
}
};
__STXXL_END_NAMESPACE
#endif