Hello list, In ACE and on Linux the Proactor pattern is not recommended. Instead of this, ACE_Dev_Poll_Reactor seems to be recommended. It is one of Reactor implementation. ACE_Dev_Poll_Reactor uses epoll in a level-trigger method. But, I am not sure of this information.... I just found some blog essays on internet. Now I wonder about boost.asio. boost.asio must have a proactor implementation on Linux, I guess. How does the proactor of boost.asio work? Does it use epoll? Is it edge-triggered? What about real-time signal? Doesn't boost.asio use real-time signal on Linux? What is the recommended implementation of boost.asio for asynchronous and non-blocking overlapped IO on Linux? Thank you in advance! ---------------------------------------- Journeyer J. Joh o o s a p r o g r a m m e r a t g m a i l d o t c o m ----------------------------------------