os/buffered_port.cpp

This example shows how to communicate between a pair of buffered ports.

/*
 * Copyright (C) 2006-2019 Istituto Italiano di Tecnologia (IIT)
 * Copyright (C) 2006-2010 RobotCub Consortium
 * All rights reserved.
 *
 * This software may be modified and distributed under the terms of the
 * BSD-3-Clause license. See the accompanying LICENSE file for details.
 */

#include <yarp/os/Network.h>
#include <yarp/os/BufferedPort.h>
#include <yarp/os/Bottle.h>
#include <yarp/os/Time.h>
#include <stdio.h>

using namespace yarp::os;

int main() {
    // Initialize YARP - some OSes need network and time service initialization
    Network yarp;

    // Work locally - don't rely on name server (just for this example).
    // If you have a YARP name server running, you can remove this line.
    Network::setLocalMode(true);

    // Create two ports that we'll be using to transmit "Bottle" objects.
    // The ports are buffered, so that sending and receiving can happen
    // in the background.
    BufferedPort<Bottle> in;
    BufferedPort<Bottle> out;

    // we will want to read every message, with no skipping of "old" messages
    // when new ones come in
    in.setStrict();

    // Name the ports
    in.open("/in");
    out.open("/out");

    // Connect the ports so that anything written from /out arrives to /in
    Network::connect("/out","/in");

    // Send one "Bottle" object.  The port is responsible for creating
    // and reusing/destroying that object, since it needs to be sure
    // it exists until communication to all recipients (just one in
    // this case) is complete.
    Bottle& outBot1 = out.prepare();   // Get the object
    outBot1.fromString("hello world"); // Set it up the way we want
    printf("Writing bottle 1 (%s)\n", outBot1.toString().c_str());
    out.write();                       // Now send it on its way

    // Send another "Bottle" object
    Bottle& outBot2 = out.prepare();
    outBot2.fromString("2 3 5 7 11");
    printf("Writing bottle 2 (%s)\n", outBot2.toString().c_str());
    out.writeStrict();                 // writeStrict() will wait for any
                                       // previous communication to finish;
                                       // write() would skip sending if
                                       // there was something being sent

    // Read the first object
    Bottle *inBot1 = in.read();
    printf("Bottle 1 is: %s\n", inBot1->toString().c_str());

    // Read the second object
    Bottle *inBot2 = in.read();
    printf("Bottle 2 is: %s\n", inBot2->toString().c_str());

    return 0;
}