Re: [Boost-users] Does lock-less queue wait on empty queue ?

Subject: Re: [Boost-users] Does lock-less queue wait on empty queue ?
From: Gavin Lambert (gavinl_at_[hidden])
Date: 2015-05-18 21:28:03

On 19/05/2015 01:02, Sebastian Messerschmidt wrote:
> Am 18.05.2015 um 13:51 schrieb Ran Shalit:
>> Hello,
>>
>> I'm newbie of boost library.
>>
>> I would like to ask if the lockless queue waits on empty queue ? (I
>> actually need it to wait).
> You can easily wait yourself, and everyone would want to wait
> differently, so there is no point in putting into the queue's
> implementation.
> For instance you could give up your scheduler time-slice, or you might
> want to spin-lock
>
> while(!queue.pop(my_data))
> {
>        boost::this_thread::yield(); //give up time slice
> }

You can also do a "real" wait until something has been pushed (which can 
be important as yield() does not let lower-priority threads run), but 
currently doing that requires using either Win32 events or using 
condition variables -- but the latter requires adding a mutex on both 
ends, which may defeat the point of using a lock-free queue in the first 
place.