"Tom Widmer" <tom_usenet@hotmail.com> wrote in message news:tcl350tm80fqpbma96j3jcsa6i6o3t9dm6@4ax.com... [snip]
Your code does have at least two major errors:
mutex::scoped_lock lock( mutex ); is a function declaration (demonstrating the danger of C++ and "using namespace boost"). You meant: mutex::scoped_lock lock(queue_mutex);
Doh! I dont get why this cold compile at all!
Also, you have implemented a stack rather than a queue; the reader should use front() and pop_front(). This didn't make much difference to the benchmark.
yeah it doesn't.
You should also probably using condition variables rather than thread::yield - thread::yield is rarely needed in properly written multithreaded code (although I've been lucky enough to write most of my threading code in a realtime operating system with deterministic scheduling).
Ok, I'm no MT expert, but I haven't seen any examples of how to do this. It would explain why you have to hack so much to call yield :-)
But in any case, your benchmark does prove a point - circular_buffer seems a bit unnecessary if you have a properly implemented std::deque, as found in Dinkumware's library for one. No ongoing memory allocation has to happen in std::deque either! This is because it can use a circular buffer for the map of blocks, and not throw away empty blocks.
ok. br Thorsten