INFO: WSA_FLAG_OVERLAPPED Needed for Timeout on WSASocket (181610)


The information in this article applies to:

  • Microsoft Platform Software Development Kit (SDK) 1.0, when used with:
    • the operating system: Microsoft Windows NT
    • Microsoft Windows 95
    • Microsoft Windows 98
    • the operating system: Microsoft Windows 2000
This article was previously published under Q181610

SUMMARY

If you create a socket using the Winsock 2 WSASocket API and you need to apply a timeout in receive or send operations on the socket, you must specify the WSA_FLAG_OVERLAPPED flag in the WSASocket call.

MORE INFORMATION

If a socket is created without the overlapped I/O attribute, all I/O operations on the socket are synchronous. So if your program has set socket options SO_SNDTIMEO and SO_RCVTIMEO, you need to make sure your socket is created with the overlapped I/O attribute to timeout your blocking send or receive operations.

The overlapped I/O attribute of a socket created via the socket API is set internally. If you use WSASocket API, you need to set the WSA_FLAG_OVERLAPPED flag yourself in the last parameter of this API call.
Modification Type:MinorLast Reviewed:7/11/2005
Keywords:kbAPI kbinfo kbnetwork kbWinsock KB181610
©2004 Microsoft Corporation. All rights reserved.