Found a bug in the source code. I have forget to get rid of some debug code.
After fix the problem, the echo_iocp program can accept 1000 online connections propriety. Test result : Clients : 1000, Messages Per Client : 1000, Byte Per Message : 52 ExecTimes: 34.229569 seconds client Send Recv total : 1000000 1000000 average : 29215/s 29215/s http://spserver.googlecode.com/files/libevent-1.4.4-iocp.zip >>> >Integrate Windows I/O Completion Port into Libevent > >IOCP is true async i/o model, and libevent is event-driven i/o model. > >1. How to emulate event-driven recv/send ? >It is possible to use IOCP to emulate event-driven mode. When you make read or >write calls, pass in a zero-byte buffer (ie, you can manage your i/o buffers >using event driven semantics). So if you issue a read passing in a zero-byte >length buffer, your will get notified when there is data to read. > >2. How to emulate event-driven accept ? >The WSAEventSelect API provides an event-driven accept mechanism. > >3. How to integrate these two mechanism ? >When we issue a WSARecv or WSASend, we need to pass a OVERLAPPED structure. >This structure has a hEvent member. > >http://msdn.microsoft.com/en-us/library/ms742203(VS.85).aspx >If the lpCompletionRoutine parameter is NULL, the hEvent parameter of >lpOverlapped is signaled when the overlapped operation completes if it >contains a valid event object handle. An application can use >WSAWaitForMultipleEvents or WSAGetOverlappedResult to wait or poll on the >event object. > >We could use one event for all WSARecv/WSASend. > >http://msdn.microsoft.com/en-us/library/ms686211(VS.85).aspx >Setting an event that is already set has no effect. > >So it is possible to use WSAWaitForMultipleEvents to integrate IOCP and >WSAEventSelect. > >4. Solution > >/* objects[0] for iocp operations, object[1..63] for accept */ >HANDLE objects[64]; >struct event * accepts[64]; > >struct win32iocp_event event1; >event1.overlapped.hEvent = objects[0]; >WSARecv( ..., &event1.overlapped, ... ); >.... > >struct win32iocp_event event2; >event2.overlapped.hEvent = objects[0]; >WSASend( ..., &event2.overlapped, ... ); >... > >WSAEventSelect( ev1->ev_fd, objects[1], FD_ACCEPT ); >accepts[1] = ev1; >... > >WSAEventSelect( ev2->ev_fd, objects[2], FD_ACCEPT ); >accepts[2] = ev2; >... > >int index = WSAWaitForMultipleEvents( 64, objects, FALSE, timeout, FALSE ); >index = index - WSA_WAIT_EVENT_0; > >if( index > 0 ) { > struct event * event = win32iocp_op->accepts[index]; > event_active (event, EV_READ | EV_ACCEPT, 1); >} > >if( index == 0 ) { > for( ; ; ) { > GetQueuedCompletionPort( ...... ); > } >} > >5. Limitation >It can only support 63 accept fds. > >6. Source code >http://spserver.googlecode.com/files/libevent-1.4.4-iocp.zip >diff file : libevent-1.4.4-iocp\libevent-iocp\diff.txt >add file : libevent-1.4.4-iocp\WIN32-Code\win32iocp.cpp > > > > > > >liusifan >2008-06-01 > _______________________________________________ Libevent-users mailing list Libevent-users@monkey.org http://monkeymail.org/mailman/listinfo/libevent-users
