tango.core.sync.Mutex.tryLock

[Jason House]

Sean Kelly wrote:
> Jason House wrote:
>> tryLock does not seem to work as I expected.  I thought it returns if 
>> it was successful or not.  What could possibly cause the code below to 
>> fail?  I'm using linux.
>>
>> myMutex.tryLock();
>> assert(myMutex.tryLock() == false); // fails
> 
> Locks in Tango are recursive, so you're guaranteed to succeed if you 
> already hold the lock.
> 
> 
> Sean

Does that mean that the mutex locking and unlocking calls are thread 
aware?  A given thread can repeatedly lock a mutex but must then unlock 
it the same number of times before the mutex is released for another 
thread to access it?

I was trying to be creative with some queue structures.  I wanted to add 
a blocking version of pop.  If nothing is in the queue, wait for that to 
change...  I was thinking that if I had a mutex that was automatically 
locked when the queue was empty, then I could implement blocking by 
quickly grabbing, then releasing a mutex.  For an empty queue, the lock 
would sit and wait.

It sounds like I can't use tango's Mutex class for this purpose because 
the push's and pop's are done by different threads.  In fact, push calls 
are done by lots of threads.  Is there anything in tango.core.sync that 
I should be using for this purpose?