tango.core.sync.Mutex.tryLock

[Jason House]

Sean Kelly wrote:
> You should look at Condition.  Use is something like this:
> 
> auto myMutex = new Mutex;
> auto myCondition = new Condition( myMutex );
> 
> Thread A (producer):
> 
> synchronized( myMutex ) {
>     myQueue.push( data );
>     myCond.notify();
> }
> 
> Thread B (consumer):
> 
> synchronized( myMutex ) {
>     while( myQueue.isEmpty )
>         myCond.wait();
> }


Correct me if I'm wrong, but the Mutex operation of tango does not do 
strange interaction with the synchronized keyword?  Wouldn't Thread B's 
"synchrnoized( myMutex )" cause Thread A to be unable to enter its 
"synchronized( myMutex )"?


> 
> In essence, Conditions are associated with a specific mutex, which is 
> atomically unlocked when wait() is called.  Thus, when thread B waits it 
> allows thread A to enter the protected region to add more data to the 
> queue.  When wait unblocks it atomically acquires the mutex again, by 
> which time thread A will have exited the protected region (earlier 
> implementations actually blocked thread A and simply transferred 
> control--this was indicated by 'signal' rather than 'notify').
> 
> 
> Sean