one shouldn't try to en/dequeue from one thread, while another thread is running the constructor/destuctor. maybe it should formulated in a better way ...
Operating on a deleted object is always undefined behaviour. I think it's not related to lockfree datastructures.
true
bool enqueue(T const & t); Shouldn't this function throw an exception if t cannot be enqueued?
i would prefer not to throw an exception! if a constant-size freelist is used, the enqueue operation may fail, although no `error' occurred. i prefer this interface
If memory for the operation cannot be obtained, I believe common practice is to throw an exception. IMO, it does not matter if a fixed size pool is exhausted or the global heap, since the effect is the same -> a no op. With current interface I'd need to always check return value for every enqueue for out of memory conditions, something I don't need to do with any other container.
true ... but if you use the fixed-size memory pool, you would have to add a try/catch block ...
bool empty(void) //warning Not thread-safe I think this function should be removed from public interface if it cannot be implemented in a thread safe manner.
i would prefer to keep it, but warn about the thread safety. i am also thinking about adding thread-unsafe version of enqueue/dequeue/push/pop, since they can be implemented in a more efficient way than the thread-safe versions. one can think of a use case, that one thread fills a fifo/queue and then notifies consumer threads ...
Would if suffice to add another constructor for that? template<class Iterator> fifo(Iterator first, Iterator last)
Then you can have an optimized way of populating the lockfree container,without adding unsafe member functions.
for my most important use case, this would not be sufficient. during some times, i am accessing my fifos from a single thread only, during other times by multiple threads ... cheers, tim -- tim@klingt.org http://tim.klingt.org Silence is only frightening to people who are compulsively verbalizing. William S. Burroughs