RpcHdr - header for remote procedure calls
#include <Dispatch/rpchdr.h>
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.
- 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.
- 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.
RpcReader(3I), RpcWriter(3I), rpcstream(3I)