- Tcl-DP remote procedure call support

L'|0u-1v'
L'0u+1v-0u'

proc MyCheck {cmd args} {
    set argc [llength $args]
    case $cmd in {
	Safe   	{return}
	puts	{return}
	eval	{return -code continue}
	set	{
		    if {$argc == 2} {
			error "Permission to set variables denied"
		    } else {
			return
		    }
		}
    }
    return -code break
}

This command arranges a clean closing of an RPC connection, on both sides of the connection. dp_CancelRPC ?peer? ?peer? ...

This command cancels current RPC invocations that are presently waiting for a return value. If no peers are specified, then all current but waiting RPC invocations are canceled. These cancelled RPC's will return an error. dp_RPC peer ?-events events?
?-timeout millisecs ??-timeoutReturn callback???
command ?args ...? This command arranges for the Tcl/Tk command and its args to be evaluated in the remote Tcl/Tk interpreter, using the RPC connection specified by peer. Before the remote evaluation of command and args, the global variable rpcFile in the remote Tcl/Tk interpreter is bound to the peer whose request is being evaluated. (Thus, in your command, you can access the rpcFile variable to figure out the RPC peer that originated the command.) The -events flag to the dp_RPC command lets you specify which events should be handled while waiting for the return value of a RPC. The -events parameter should be a list of the tokens X, rpc, file, timer, idle, all, or none, where each token represents an event type. Presently, a rpc token is the same as a file token. The none token is the default. See Tk_DoOneEvent(3) for more information on these event types. The -timeout flag to the dp_RPC command lets you specify an integer millisecond timeout value for the RPC, which by default will return an error value if the timeout occurs. Supplying a -timeout value of zero or less than zero means that no timeout will be checked. If you want to use timeouts, you must also specify -events to be anything but none. The -timeoutReturn callback, if specified, is evaluated when a timeout occurs. The callback is evaluated with the peer identifier appended. If a timeout occurs and a -timeoutReturn callback was specified, then the return value of the callback is used as the return value of the timed-out dp_RPC. Otherwise the timed-out RPC returns an error. dp_RDO peer ?-callback resultCallback? ?-onerror errorCallback? command ?args ...? This command arranges for command and its args to be remotely evaluated in the Tcl/Tk interpreter whose connection is specified by peer argument. Unlike the dp_RPC command, the dp_RDO command does not wait for a return value to be returned by the remote Tcl/Tk interpreter, but returns immediately. Before the remote evaluation, the global variable rpcFile in the remote Tcl/Tk interpreter is set as described above for the dp_RPC command. You can use the resultCallback parameter of dp_RDO to asynchronously retrieve the value of the remote evaluation. If specified, the callback command appended with the return value of the remote command evaluation is evaluated in the local Tcl/Tk interpreter. If you specify an errorCallback and an error occurs during the remote evaluation, errorCallback will be evaluated with the error message as a parameter. The default value for errorCallback is tkerror. If you wish to ignore errors generated during RDO evaluation, specify the keyword "none" as errorCallback. The following example creates an RPC server to return unique integer identifiers. On the host zonker (the server):

	dp_MakeRPCServer 4545

	dp_Host -
	dp_Host +128.32.149.*
	set myId 0
	proc GetId {} {global myId; incr myId; return $myId}

	set server [dp_MakeRPCClient zonker 4545]
	dp_RPC $server GetId

	set server [dp_MakeRPCClient zonker 4545]
	error -> Connection refused: Host not authorized