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Subject: Re: [Boost-users] condition_variable
From: Nikolai N Fetissov (nikolai-boost_at_[hidden])
Date: 2009-12-10 13:25:32

> Why is it that since we already hold a mutex in the requesting thread, the
> thread handling the response can successfully lock that mutex too? Does
> the
> condition.wait call set something in the lock?
> Thanks,


The idea of wait on a condition variable is to atomically
release the mutex and enter some sort of sleep mode, which is
later interrupted by a wake-up from a different thread.
At that point the mutex is re-aquired.
So, yes, condition.wait() unlocks the mutex and waits for
notification, then locks the mutex again.


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