101 lines
2.4 KiB
C++
101 lines
2.4 KiB
C++
|
#include <fc/interprocess/file_mutex.hpp>
|
||
|
|
//#include <fc/thread/mutex.hpp>
|
||
|
|
#include <fc/thread/mutex.hpp>
|
||
|
|
#include <fc/filesystem.hpp>
|
||
|
|
#include <boost/interprocess/sync/file_lock.hpp>
|
||
|
|
#include <boost/interprocess/sync/scoped_lock.hpp>
|
||
|
|
#include <boost/atomic.hpp>
|
||
|
|
|
||
|
|
#include <fc/thread/thread.hpp>
|
||
|
|
#include <fc/log/logger.hpp>
|
||
|
|
|
||
|
|
namespace fc {
|
||
|
|
namespace bip = boost::interprocess;
|
||
|
|
|
||
|
|
void yield();
|
||
|
|
|
||
|
|
namespace detail {
|
||
|
|
class file_mutex_impl {
|
||
|
|
public:
|
||
|
|
file_mutex_impl( const char* f )
|
||
|
|
:_file_mutex( f ),_reader_count(0){}
|
||
|
|
|
||
|
|
fc::mutex _write_lock;
|
||
|
|
bip::file_lock _file_mutex;
|
||
|
|
boost::atomic<int> _reader_count;
|
||
|
|
};
|
||
|
|
}
|
||
|
|
|
||
|
|
file_mutex::file_mutex( const fc::path& file )
|
||
|
|
{
|
||
|
|
my.reset( new detail::file_mutex_impl( file.generic_string().c_str() ) );
|
||
|
|
}
|
||
|
|
|
||
|
|
file_mutex::~file_mutex() {
|
||
|
|
}
|
||
|
|
|
||
|
|
int file_mutex::readers()const {
|
||
|
|
return my->_reader_count.load();
|
||
|
|
}
|
||
|
|
|
||
|
|
bool file_mutex::try_lock() {
|
||
|
|
return false;
|
||
|
|
if( my->_write_lock.try_lock() ) {
|
||
|
|
if( my->_file_mutex.try_lock() )
|
||
|
|
return true;
|
||
|
|
}
|
||
|
|
if( my->_file_mutex.try_lock() ) {
|
||
|
|
if( my->_write_lock.try_lock() ) {
|
||
|
|
return true;
|
||
|
|
} else {
|
||
|
|
my->_file_mutex.unlock();
|
||
|
|
}
|
||
|
|
}
|
||
|
|
return false;
|
||
|
|
}
|
||
|
|
|
||
|
|
bool file_mutex::try_lock_for( const microseconds& rel_time ) {
|
||
|
|
return false;
|
||
|
|
}
|
||
|
|
|
||
|
|
bool file_mutex::try_lock_until( const time_point& abs_time ) {
|
||
|
|
return false;
|
||
|
|
}
|
||
|
|
|
||
|
|
void file_mutex::lock() {
|
||
|
|
my->_write_lock.lock();
|
||
|
|
while( my->_reader_count.load() > 0 ) {
|
||
|
|
fc::usleep( fc::microseconds(10) );
|
||
|
|
}
|
||
|
|
my->_file_mutex.lock();
|
||
|
|
}
|
||
|
|
|
||
|
|
void file_mutex::unlock() {
|
||
|
|
my->_file_mutex.unlock();
|
||
|
|
my->_write_lock.unlock();
|
||
|
|
}
|
||
|
|
|
||
|
|
void file_mutex::lock_shared() {
|
||
|
|
bip::scoped_lock< fc::mutex > lock( my->_write_lock );
|
||
|
|
if( 0 == my->_reader_count.fetch_add( 1, boost::memory_order_relaxed ) )
|
||
|
|
my->_file_mutex.lock_sharable();
|
||
|
|
}
|
||
|
|
|
||
|
|
void file_mutex::unlock_shared() {
|
||
|
|
if( 1 == my->_reader_count.fetch_add( -1, boost::memory_order_relaxed ) )
|
||
|
|
my->_file_mutex.unlock_sharable();
|
||
|
|
}
|
||
|
|
|
||
|
|
bool file_mutex::try_lock_shared() {
|
||
|
|
return false;
|
||
|
|
if( my->_write_lock.try_lock() ) {
|
||
|
|
if( my->_reader_count.load() == 0 && my->_file_mutex.try_lock_sharable() ) {
|
||
|
|
my->_reader_count++;
|
||
|
|
}
|
||
|
|
my->_write_lock.unlock();
|
||
|
|
}
|
||
|
|
return false;
|
||
|
|
}
|
||
|
|
|
||
|
|
} // namespace fc
|