[Monotone-devel] Help: select() like functionality on pipes on Win32 - how?

[Christof Petig]

Good morning,

In an attempt to get the functionality written by me* into the main
branch I implemented a common infrastructure: Portable bidirectional
pipes to a program (like a bidirectional popen()). So far it had been
easy :-S

But the problem lies somewhere else: I have this infrastructure
(netxx_pipe.* on the n.v.m.cvssync.win32 branch**) ready and tested but
... to make netsync over pipes work I need a Netxx::Probe which can cope
with pipes.

On Unix this is a piece of cake: select works against everything. On
Win32 select only works against sockets, not pipes or files. So my
question is:

==> How can I wait for data to get available on a pipe on Win32? <==

I know about SetCommTimeout() (to implement non blocking IO) and
ReadFileEx() (so called overlapping IO) but both methods need an actual
read. There seems to be no way to implement a select like function (on a
single pipe!) on windows.

My current (desperate) plan is to use ReadFileEx to implement
overlapping IO and store the data in the Netxx::Stream for later reading
but if anybody knows an easier way please tell me

  Christof

*) netsync over pipes (local serverless sync), netsync over ssh (remote
serverless sync), cvs pull and push

**) if you want to use this class you might need to fall back to
revision 5b84bca4ea28c6522af6e108f65b6f37dc0deeb3 since newer revisions
are work in progress.

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