RpcHdr (3I)

#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)