Subject: Re: [boost] [thread] countdown_latch
From: Michael Marcin (mike.marcin_at_[hidden])
Date: 2013-05-12 18:45:02
On 5/12/2013 6:49 AM, Rob Stewart wrote:
> On May 11, 2013, at 5:29 PM, Gaetano Mendola <mendola_at_[hidden]> wrote:
>> On 21/04/2013 12.54, Rob Stewart wrote:
>>> I'd prefer to create a barrier class and, in your example, it would release waiting threads when two are blocked behind it. IOW, you'd create a barrier for two threads and both thread_proc() and the constructor would wait() on the barrier. Once both threads have called wait(), they are both released. (I plan to present that at C++ Now, this year.)
>> As said that's create a not needed "wait" on the thread body, what the OP (and me for the matter) needs is that *only* thread creator is blocked waiting for the threads to arrive at certain point of the execution.
> It seems to me that wait is inconsequential relative to the cost of creating a thread. If this were part of the thread creation process, an option to thread's constructor, say, there would be some convenience, but the performance difference doesn't seem worthwhile. Have I missed something?
The created thread is already executing when it gets to the latch. Why
would you want to introduce synchronization, and potentially block the
thread, where none is needed?
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