NAME

       RpcHdr - header for remote procedure calls

SYNOPSIS

       #include <Dispatch/rpchdr.h>

DESCRIPTION

       An  RpcHdr  enables  an  RPC  request to be sent or received.  To send an RPC request, you
       would insert an RpcHdr into an rpcstream followed by any  arguments  and  then  flush  the
       rpcstream  if  you wanted the request to be sent immediately.  The rpcstream automatically
       fills in each RPC request's length field.  To receive an RPC request, you would extract an
       RpcHdr  from  an  rpcstream  and  examine  the  ``request()''  member  to  determine which
       additional arguments need to be extracted as well.  You can examine the ``ndata()'' member
       too if you need to estimate how much space to allocate.

CONSTRUCTORS

       RpcHdr(void* writer, int request)
       RpcHdr(int request)
       RpcHdr()
              Construct   an   initialized   header  for  an  outgoing  RPC  request  (first  two
              constructors) or construct an uninitialized header  for  an  incoming  RPC  request
              (third  constructor).  To initialize the header, you'll have to store the request's
              protocol number.  You can also store the address of  the  writer  sending  the  RPC
              request  if  you  want  to route the RPC request to a specific reader on the peer's
              side.

PUBLIC OPERATIONS

       unsigned long reader()
       int request()
       unsigned int ndata()
              Get information about the RPC request.  ``reader()'' identifies  the  reader  which
              should  handle the RPC request.  ``request()'' identifies the action that should be
              performed.  ``ndata()'' gives the number of data bytes following the header,  which
              may be useful for estimating the amount of space that must be allocated to store an
              argument.

SEE ALSO

       RpcReader(3I), RpcWriter(3I), rpcstream(3I)