[Boost-users] Multiple calls to tcp::socket::async_receive fail on Windows

Subject: [Boost-users] Multiple calls to tcp::socket::async_receive fail on Windows
From: Peter Chapman (petechap_at_[hidden])
Date: 2009-08-18 11:13:32

I'm under the impression that queueing several async reads will allow
the OS to fill one buffer while the read handler for a previous read
is still executing.

This comes partly from reading:
http://www.jetbyte.com/portfolio-showarticle.asp?articleId=44&catId=1&subcatId=2

Although I can't find any mention of this practice in the asio docs or
examples, it seems to "mostly work". And it makes logical sense.

My program is:
- Single-threaded
- Not using "composed" reads (ie boost::asio::async_read)

On Linux this technique works fine for multiple pending reads.
On Windows, it sometimes leads to handlers being called in the wrong order.

My sample program (attached) can be called in 2 ways:
a) to write a known data stream to a socket
b) to compare the same stream of data to bytes being read from a
socket via multiple async_receive()s.

So in one terminal, receive data using 8 concurrent async_receives:
async_recv.exe receive 8

and in the other:
async_recv.exe send

On Windows (XP Pro 64, boost 1.39), the first program exits within a
few seconds saying "streams differ".
I haven't been able to reproduce the failure on XP Pro 32, Server 2003
or Linux, although this may just be timing dependent.

Am I doing something wrong or unreasonable?

Thanks!
Pete