PRB: Named Pipe Write() Limited to 64K

ID: Q119218

The information in this article applies to:

• Microsoft Win32 Application Programming Interface (API) included with:

      - Microsoft Windows NT versions 3.1, 3.5, 3.51, 4.0
  

SYMPTOMS

WriteFile() returns FALSE and GetLastError() returns ERROR_MORE_DATA when WriteFile() writes to a message-mode named pipe using a buffer greater than 64K.

CAUSE

There is a 64K limit on named pipe writes.

RESOLUTION

The error is different from ERROR_MORE_DATA on the reader side, where bytes have already been read and the operation should be retried for the remaining message. The real error is STATUS_BUFFER_OVERFLOW. No data is transmitted; therefore, the write operation must be retried using a smaller buffer.

Additional query words:

Keywords          : kbnetwork kbAPI kbIPC kbKernBase kbPipes kbSDKPlatform kbGrpNet kbGrpKernBase 
Version           : 3.10 3.50 3.51 4.00
Platform          : NT WINDOWS

Last Reviewed: September 12, 1998