BUG: Winsock 2 APC Calls Get Lost on Windows 95 & 98

ID: Q192569

The information in this article applies to:

• Microsoft Win32 Software Development Kit (SDK) on the following platforms:

      - Windows 95
      - Windows 98
  

SYMPTOMS

Under Windows 95 or Windows 98, Winsock 2 Asynchronous Procedure Calls (APCs) might get lost under stress conditions. This means that callback functions supplied to functions, such as WSASend and WSARecv, when using overlapped I/O might not get called and data could get lost.

CAUSE

Under Windows 95 and Windows 98, memory to complete the APC operation is allocated during the callback. If memory is not available at that time, the APC is lost.

RESOLUTION

If you anticipate servicing a large number of operations in quick succession, do not use callbacks on Windows 95 or Windows 98. Instead, use overlapped I/O signaled through events.

STATUS

Microsoft has confirmed this to be a bug in the Microsoft products listed at the beginning of this article. We are researching this bug and will post new information here in the Microsoft Knowledge Base as it becomes available.

Additional query words:

Keywords          : kbnetwork kbAPI kbSDKPlatform kbWinOS95bug kbWinOS98bug kbWinsock kbGrpNet 
Issue type        : kbbug

Last Reviewed: September 13, 1998