
JOAQUIN M. LOPEZ MUÑOZ wrote:
http://www2.open-std.org/JTC1/sc22/wg21/docs/papers/2007/n2276.html
What is the relationship with this proposal of the threadpool library that is being discussed these days here at the Boost list?
My _guess_ is that the C++ standard committee is targeting a thread pool which can help to ease extraction of parallel performance, not a fully configurable templated thread pool with lots of neat features. I believe the standard efforts are inspired by what java (see java.util.concurrency and the part called the fork-join framework) and .NET standard libraries (TPL, task parallel library) and intel thread building blocks (a C++ library) provide. They all have thread pools which internally employs work stealing-based scheduling and tries to keep a number of worker threads equivalent to the number of cores. Above the thread pool, there are constructs such as parallel_for. Having such high-level constructs is going to be very important in extracting parallel performance of thread based languages. Read section 4.6 of my master's thesis to get a basic understanding of thread-level scheduling, it can be found at: www.johantorp.com And see intel TBB excellent tutorial which explains their approach in rather much detail: http://www.threadingbuildingblocks.org/documentation.php My five cents is that it would be great to separate the concerns of a thread pool and scheduling. But the real value for most applications would be to have parallel constructs (such as parallel_for) built on a single thread pool with smart work-stealing scheduling and a number of worker threads hinted to be bound to cores by processor affinity. To my knowledge, out of the .NET, java and TBB, only TBB exposes its thread pool. Hence, a simple interface such as launch_in_pool with a decent implementation might provide a lot more value than a fully configurable thread pool library. In practice, just providing the interface to launch_in_pool has proven difficult as it returns a future value. The problem is nailing down a future interface which is both expressive and can be implemented in a lightweight manner. Best Regards, Johan Torp www.johantorp.com -- View this message in context: http://www.nabble.com/-threadpool--relation-with-TR2-proposal-tp19452045p194... Sent from the Boost - Dev mailing list archive at Nabble.com.