will socket async operation ever complete synchronously?

Question

According to http://support.microsoft.com/kb/156932 there are conditions under which an asynchronous Disk IO operation may complete synchronously. Is this only applicable to Disk IO or can similar conditions apply to Network IO?

UPDATE: i've tested this now with the debugger and have verified that 1) if there is data in the receive buffer the operation will complete synchronously 2) the IOCP will fire a callback regardless.

score 1 · Accepted Answer · answered Jul 16 '13 at 09:49

1

Certainly, if for example you're reading data that is already present in the socket receive buffer. The real question is what difference would it make to you?

answered Jul 16 '13 at 09:49

user207421

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i am using IOCompletionPort with a worker thread pool, so i want to know if i can rely on a callback happening to do my processing or weather i should handle the processing immediately – Lawrence Ward Jul 16 '13 at 09:51
Why? The callback will be called. Let it happen. – user207421 Jul 16 '13 at 09:59
even if ReadFile return true? – Lawrence Ward Jul 16 '13 at 10:01
even **before** ReadFile returns true. That's why the case is named "synchronously". – MSalters Jul 16 '13 at 10:04

will socket async operation ever complete synchronously?

1 Answers1