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FLUSH(5)                      File Formats Manual                     FLUSH(5)



NAME
       flush - abort a message

SYNOPSIS
       Tflush  tag[2] oldtag[2]
       Rflush  tag[2]

DESCRIPTION
       When the response to a request is no longer needed, such as when a user
       interrupts a process doing a read(2), a Tflush request is sent  to  the
       server  to  purge  the  pending response.  The message being flushed is
       identified by oldtag.  The  semantics  of  flush  depends  on  messages
       arriving in order.

       The server must answer the flush message immediately.  If it recognizes
       oldtag as the tag of a pending transaction, it should abort any pending
       response  and discard that tag.  In either case, it should respond with
       an Rflush echoing the tag (not oldtag) of the Tflush message.  A Tflush
       can never be responded to by an Rerror message.

       When  the  client  sends  the  Tflush, it should disregard all messages
       received with tag oldtag until the corresponding Rflush is received, at
       which point oldtag may be recycled for subsequent messages.

       Several exceptional conditions are handled correctly by the above spec-
       ification: sending multiple  flushes  for  a  single  tag,  flushing  a
       Tflush, and flushing an invalid tag.



                                                                      FLUSH(5)