RE: [boost] Re: sockets /network programming Requirements

From: scleary_at_[hidden]
Date: 2001-07-31 07:58:45

> The closest match in Windows would be to use i/o completion ports.  
> It's inextricably linked to threading, but completion routines work 
> for both socket and file operations (and perhaps others as well -- 
> you can explicitly signal an operation as complete) and are quite 
> similar to poll().  In addition, they remove the 64 event limitation 
> of WSAWaitForMultipleEvents.

I/O completion ports are only available on NT.  I/O completion routines (a
type of Overlapped operation) do work well, but some asynchronous
capabilities (such as host name lookup) only support Win32 Messages.

> Still, this is a far cry from BSD sockets.  Settling on a portable 
> interface might be difficult... but if the library is buit on select
> () no Windows programmers may use it (I probably wouldn't).

As has been noted, a portable interface for blocking calls would be easy.
But I'd like to see us tackle the asynchronous version if possible.  I agree
with your statement that Win32 programmers will reject any select()-based
solution; it's in WinSock only to ease porting Unix apps.

There's also some differences in the logic between select() and Overlapped
completion notification (whether through I/O completion routines OR
WSAWaitForMultipleEvents): in general, Overlapped tells you when an
operation has completed; select() tells you when an operation may begin.
Win32 programmers will prefer the Overlapped logic.

        -Steve