----- Original Message ----- From: <k-oli@gmx.de> To: <boost@lists.boost.org> Sent: Saturday, November 22, 2008 8:40 PM Subject: [boost] [threadpool] new version - supporting future library(C++0x) from Anthony Williams
Hello,
I've uploaded a new version of boost.threadpool (v17) at http://www.boostpro.com/vault/index.php?action=downloadfile&filename=boost-threadpool.v17.tar.gz&directory=Concurrent%20Programming&.
Hi, I have some suggestion to the interface: Task class * Adding a get_future function allows to use wait_for_all and wait_for_any or overload these functions for tasks. * A task is an asynchronous completion token so it will be great if it shares the same interface as futures: * Add wait, wait_until, wait_for * Add a callback setting and as threads * Add detach (this allows to free the interrupter) * Add interruption_requested * Add join (equivalent to wait) * Add joinable (equivalent interrupter pressent) * It could be useful to get the pool associated to a task (this is possible if task is a inner class of pool, see below). This allows a user having a reference to a task to shutdown a thread pool * Add a function get_thread_pool() * Task can also be seen as asynchronous executors which are able to fork a new task associated to the execution of a function * Add a fork function which will submit a new function to the pool associated to the task task<R>::fork(f); * Add a this_task::fork function which submit a new function to the pool associated to the current worker. This avoid to pass the task or pool as parameters to other functions called in this thread. Pool class * It will be interesting to be able to wait actively on other synchronization mechanisms. * Add a public re_schedule_until_ready template <typename ACT> void re_schedule_until_ready(ACT& fut ) { if ( tss_worker_.get() ) { while ( ! fut.is_ready() ) if ( ! tss_worker_->re_schedule() ) break; } } For example this_task::sleep_until and sleep_for: struct time_reached { time_reached(system_time& abs_time) : abs_time(abs_time) {} bool is_ready() { return get_system_time() >= abs_time_; } }; this_task::sleep_until(system_type& abs_time) { if (this_task::get_thread_pool()) { time_reached t(abs_time); this_task::get_thread_pool()->re_schedule_until_ready(t); } else this_thread::sleep_until(abs_time); } BTW, the friend declaration in tp::pool 'template< typename R > friend class task;' do not works for its use in its inner class 'template< typename Pool > class impl_future_wrapper' (At least not with cygwin gcc 3.4.4 Implementation * I see that the struct impl_future declare its functions virtual? If you declare the task class local to the pool class you will know the pool type and so no need to use a wrapper, i.e. What do you think? The single inconvenient is that the user needs to declare its task as pool_type::task<int> tsk = p.submit(f); But if you we register the task class with Boost.Typeof the user can write BOOST_AUTO(tsk, p.submit(f)) or in C++0x auto tsk = p.submit(f); You just need to add a file // boost/tp/typeof/task.hpp #ifndef BOOST_TP_TYPEOF_TASK__HPP #include <boost/tp/task.hpp> #include <boost/typeof/typeof.hpp> #include BOOST_TYPEOF_INCREMENT_REGISTRATION_GROUP() BOOST_TYPEOF_REGISTER_TEMPLATE(boost::tp::task, 1) #endif Documentation * It is not clear from the documentation which is the role of timed_submit. I supose it is returns if the task can not be put on the channel queue. Could you clarify? Best regrads, _____________________ Vicente Juan Botet Escribá