Re: [boost] [lockfree] Faulty (?) static assert

Subject: Re: [boost] [lockfree] Faulty (?) static assert
From: Tim Blechmann (tim_at_[hidden])
Date: 2012-09-02 09:56:48

>>> which implies that 'has_capacity' is allowed to be false. From what I
>>> can see 'has_capacity' could be false, indeed, in particular if the
>>> queue is not bounded in size.
>>
>> the idea is that the default constructor is only allowed, when the
>> capacity is set at compile-time. otherwise the data structure won't be
>> completely lockfree, as creating new nodes will hit the memory allocator.
>> so the assertion is correct, but the initialization of the pool can be
>> changed.
> 
> Hmmm, I do not understand. If the queue is constructed with
> fixed_size<false> (which is the default), this assertion will _always_ fire
> as you're not required to specify a capacity in this case.

that's the purpose of this assertion. if the data structure is not
fixed-sized, you should use the explicit queue(int capacity) constructor
in order to populate the free-list.

cheers, tim