pthread windows event equivalent question
- by ScaryAardvark
I have the following code which replicates the windows manual and auto reset events.
class event
{
public:
event( bool signalled = false, bool ar = true ) :
_auto( ar ),
_signalled( signalled )
{
pthread_mutex_init( &_mutex, NULL );
pthread_cond_init( &_cond, NULL );
}
~event()
{
pthread_cond_destroy( &_cond );
pthread_mutex_destroy( &_mutex );
}
void set()
{
pthread_mutex_lock( &_mutex );
// only set and signal if we are unset
if ( _signalled == false )
{
_signalled = true;
pthread_cond_signal( &_cond );
}
pthread_mutex_unlock( &_mutex );
}
void wait()
{
pthread_mutex_lock( &_mutex );
while ( _signalled == false )
{
pthread_cond_wait( &_cond, &_mutex );
}
// if we're an autoreset event, auto reset
if ( _auto )
{
_signalled = false;
}
pthread_mutex_unlock( &_mutex );
}
void reset()
{
pthread_mutex_lock( &_mutex );
_signalled = false;
pthread_mutex_unlock( &_mutex );
}
private:
pthread_mutex_t _mutex;
pthread_cond_t _cond;
bool _signalled;
bool _auto;
};
My question surrounds the "optimisation" I've put in place in the set() method where I only call pthread_cond_signal() if the event was unsignalled. Is this a valid optimisation or have I introduced some subtle flaw by doing so.
