Re: [Boost-bugs] [Boost C++ Libraries] #8967: Spurious zero bytes written and eof notifications highlight ASIO IOCP issues

Subject: Re: [Boost-bugs] [Boost C++ Libraries] #8967: Spurious zero bytes written and eof notifications highlight ASIO IOCP issues
From: Boost C++ Libraries (noreply_at_[hidden])
Date: 2014-05-07 00:07:29

#8967: Spurious zero bytes written and eof notifications highlight ASIO IOCP
issues
-------------------------+-------------------------------------------------
  Reporter:              |      Owner:  chris_kohlhoff
  simoncperkins@…        |     Status:  closed
      Type:  Bugs        |  Component:  asio
 Milestone:  To Be       |   Severity:  Problem
  Determined             |   Keywords:  eof GetQueuedCompletionStatus
   Version:  Boost       |  WSARecv WSASend overlapped
  1.54.0                 |
Resolution:  invalid     |
-------------------------+-------------------------------------------------

Comment (by chris_kohlhoff):

 The comment:

 > lpNumberOfBytesRecvd
 >...
 > Use NULL for this parameter if the lpOverlapped parameter is not NULL to
 avoid potentially erroneous results
 >
 > is BAD advice.
 >
 > If call WSARecv and pass NULL as lpNumberOfBytesRecvd and  not-NULL
 lpOverlapped, then your application will generate a bunch of these:
 >
 > Access violation - code c0000005 (first chance)

 describes the problem exactly. I encountered it on Windows XP, or possibly
 2000, but I no longer have the system details. Furthermore, the MSDN
 Library shipped with Visual Studio 2008 did not include the "advice" for
 lpNumberOfBytesRecvd. What it does say is:

 > If an overlapped operation completes immediately, WSARecv returns a
 value of zero and the lpNumberOfBytesRecvd parameter is updated with the
 number of bytes received ...

 This text still appears in the latest MSDN, for what it's worth.

-- 
Ticket URL: <https://svn.boost.org/trac/boost/ticket/8967#comment:11>
Boost C++ Libraries <http://www.boost.org/>
Boost provides free peer-reviewed portable C++ source libraries.