Re: [boost] Re: [thread] null_mutex

From: Peter Dimov (pdimov_at_[hidden])
Date: 2005-06-10 16:34:08

Jody Hagins wrote:
> On Fri, 10 Jun 2005 22:14:41 +0300
> "Peter Dimov" <pdimov_at_[hidden]> wrote:
>
>> How is a condition variable supposed to behave when used with a null
>> mutex?  Is this a legitimate use case?
>
> I believe it is a valid use case.  Consider code for something like a
> popping a message off a message queue.  In such a case, the pop()
> member function would block until the message queue was not empty.
> In a single-thread case (i.e., using null_mutex), you would expect
> some kind of exception, because you can not call pop with an empty
> queue in a single threaded case.

Let's take a step back. Why would I use the message queue at all in a single 
threaded program? Its whole purpose is to enable inter-thread communication, 
right?