Re: [Boost-users] [statechart] Asynchronous Machines

From: David Greene (greened_at_[hidden])
Date: 2006-02-22 11:33:43

Andreas Huber wrote:

>>Hmm...I was going to use a synchronous machine due to the state
>>access problems I outlined in another message, but now I see that
>>won't work if terminated_ is in cacheable memory and there is no
>>hardware coherence.  For my purposes that's probably ok because
>>we'll only run on machines with hardware coherence.  Therefore
>>if I understand you correctly, it's ok if different threads
>>calls process_event() as long as the call (and any call to
>>statechart routines) are guarded by mutexes to avoid the
>>non-reentrancy problems.
> 
> That'll probably work, given that you use a single mutex to protect scheduler 
> & machine. However, this is rather ugly as you end up locking two mutextes 
> whenever you queue an event.

Does this imply that there's a mutex in state_machine somewhere that
gets locked on some operations?  That could definitely be problematic
and I'll have to take extra care to avoid deadlock.

                               -Dave