Sockets won't block

[%u]

When I open sockets they don't seem to like blocking, and return immediately
when I do a 'receive' (with 0 bytes of data of course)

The routine (client and server in 1) is as follows (excuse all the tracing
'writefln's and a few artifacts from the original C++ version :-)

---- code ----
// $Header: /home/CVS/atm/ATMsock_t.cpp,v 1.1 1980/04/16 23:53:02 graeme Exp $
// $Header: /home/CVS/atm/ATMsock_t.cpp,v 1.1 1980/04/16 23:53:02 graeme Exp $

// Author:	Graeme Defty
// $Date: 1980/04/16 23:53:02 $
/*
	This module runs tests on the ATM Socket class.
*/

static const char pgmid[] =
	"$Id: ATMsock_t.cpp,v 1.1 1980/04/16 23:53:02 graeme Exp $";

// $Source: /home/CVS/atm/ATMsock_t.cpp,v $ //

//#include <fstream>
//#include <signal.h>
//#include <unistd.h>
import std.c.time;
import std.stdio;
import std.string;
import std.socket;

//#include "ATMsock.h"

//#include "assure.h"

// ============ Don't think we need these any more ==========
//static void
//sig_h(int signo) {
//	cout << "Caught signal " << signo << endl;
//	if (signo == SIGINT) exit(0);
//}
// ========================================================

int
main (char[][] args) {

	int portnum = 1234;
	char [] buf;
	char [] rcvbuf;
	Socket	mySock;
	InternetAddress myAddr, farAddr;
	int len;
	int count;
//	struct sigaction sigact;
//	struct sigaction oldsigact;

// first handle the arguments . . .
	if (args.length>2) {
		portnum = atoi(args[2]);
	}
	writefln("Using port number " , portnum , ".");

	// === Signal handling seems to be unneccessary now ====

// then set up signal handling . . .
//	sigact.sa_handler	= sig_h;
//	sigemptyset (&sigact.sa_mask);
//	sigact.sa_flags	= 0;
//	for (len=1; len<48; len++) {
//		if (sigaction(len, &sigact, &oldsigact) == -1) {
//			perror ("Catching Signal");
//		} else {
//			cout << "Signal " << len << " set." << endl;
//		}
//	}

	if (args.length>1 && args[1] == "s") {

		writefln("Test begins for server . . .");

		myAddr = new InternetAddress("127.0.0.1", portnum);
		mySock = new Socket(AddressFamily.INET, SocketType.STREAM);
		writefln("Server created . . .");
		mySock.bind(myAddr);
		writefln(". . . and bound . . .");
		mySock.listen(5);
		writefln(". . . and listening.");

		while (true) {
			Socket otherSock = mySock.accept();
			assert(otherSock.isAlive);
			writefln("Accepted a connection . . .");
			writefln("Far address is ", otherSock.remoteAddress);

			otherSock.blocking = true;
			assert(otherSock.isAlive);
			sleep(1);

			len = otherSock.receive(buf);
			assert(len != Socket.ERROR);
			assert(otherSock.isAlive);
			writefln("Received data (", len , ") '", buf , "'.");

			otherSock.send(buf);
			assert(otherSock.isAlive);
			writefln("Sent that data . . .");
//			mySock.close;
//			writefln(". . . and closed the socket.");
		}

	} else {
		writefln("Test begins for client . . .");

		myAddr = new InternetAddress("127.0.0.1", portnum);
		farAddr = new InternetAddress("127.0.0.1", 1234);

		for (count = 0; count < 12 ; count++) {
			if (count % 1000 == 0) {writefln("Done " , count);}

			mySock = new Socket(AddressFamily.INET, SocketType.STREAM);
			assert(mySock.isAlive);
			writefln("Client created . . .");

			mySock.bind(myAddr);
			assert(mySock.isAlive);
			writefln(". . . and bound . . .");

			mySock.connect(farAddr);
			assert(mySock.isAlive);
			writefln(". . . and connected.");

			writefln("Far address is ", mySock.remoteAddress);

			buf = format("This is data line ", count);
			len = mySock.send(buf);
			assert(mySock.isAlive);
			writefln("Sent (", len , ") '", buf , "' and received '", rcvbuf , "'.");

			len = mySock.receive(rcvbuf);
			assert(mySock.isAlive);
//			assert (buf == rcvbuf, "Sent and received data different!");
			if (buf != rcvbuf) {
				writefln("ERROR: Sent '", buf , "' and received '", rcvbuf , "'.");
			}
			mySock.close();
			sleep(10);
		}
	}
	writefln("Test Done!");
	return 0;
}

---- end code ----

I would appreciate any guidance.

Thanks,

graeme