[Libevent-users] Add support for WINDOWS Overlapped IO

[Toby Douglass]

Zhu Han wrote:
> I have made some mistake when I type the above words. I just mean you 
> should
> issue socket_internal_iocp_read firstly and then let the callbacks to
> consume the data. However, in your code, you invoke the callbacks before
> socket_internal_iocp_read. See the  following snippet:
>      siss->callback_function( siss->socket,
> SOCKET_IOCP_SOCKET_RECV_SUCCESS, siss->read_buffer, byte_count, (void *)
> siss->user_state );
>      socket_internal_iocp_read( siss );

Ah.  Go look at socket_iocp_add_socket().  You'll find the very first 
call to socket_internal_iocp_read() occurs at the end of *that* 
function, which gets the read ball rolling.

> As others have pointed out,  Async WRITE is important for high-performance
> server.

Yes, it's clear.  I'm going to add it.

>> Note though that with GetQueuedCompletionStatus(), the user has no
>> synchronization work to do.  The API handles it all behind the scenes.
> 
> Single-thread event-driven model just means the event loop is running in 
> one thread's context. There a lot of ways to combine it with the multi-thread
> worker.

Ye-e-e-s-s...and no.  I think I understand you to mean that we could, 
for example, arrange it so we have 2xCPU threads running GQCS and when 
one of those threads returns with a complete, we trigger or signal the 
main event loop thread?  the problem with that surely is going to be the 
large amount of thread switching.