CoreDX DDS Hello World Example in C#
Here is a CoreDX DDS version of the typical "Hello World" application.
This example consists of two applications: one application that publishes a simple string message Topic (the data contains the string "hello world!"); and one application that subscribes to this topic.
The source code presented here is the 'C#' programming language version of the 'hello world' applications. It can interoperate with 'hello world' applications written in other languages, or running on different hardware platforms.
file: hello.ddl
struct StringMsg
{
string msg;
};
file: hello_pub.cs
/****************************************************************
*
* file: hello_pub.cs
* desc: Provides a simple C# 'hello world' DDS publisher.
* This publishing application will send data
* to the example 'hello world' subscribing
* application (hello_sub).
*
****************************************************************
*
* Coypright(C) 2009-2011 Twin Oaks Computing, Inc
* All rights reserved. Castle Rock, CO 80108
*
*****************************************************************
*
* This file is provided by Twin Oaks Computing, Inc
* as an example. It is provided in the hope that it will be
* useful but WITHOUT ANY WARRANTY; without even the implied
* warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
* PURPOSE. TOC Inc assumes no liability or responsibilty for
* the use of this information for any purpose.
*
****************************************************************/
using System;
using System.Runtime.InteropServices;
using System.Threading;
using System.Collections.Generic;
using com.toc.coredx.DDS;
public class hello_pub {
public static void Main()
{
System.Console.WriteLine("STARTING -------------------------");
DomainParticipantFactory dpf = DomainParticipantFactory.get_instance();
DomainParticipant dp = null;
System.Console.WriteLine("CREATE PARTICIPANT ---------------");
dp = dpf.create_participant(0, /* domain Id */
DDS.PARTICIPANT_QOS_DEFAULT, /* default qos */
null, /* no listener */
0);
System.Console.WriteLine("REGISTERING TYPE -----------------");
ReturnCode_t retval = StringMsgTypeSupport.register_type(dp, null);
System.Console.WriteLine("CREATE TOPIC ---------------------");
Topic top = dp.create_topic("helloTopic", StringMsgTypeSupport.get_type_name(),
null, // default qos
null, 0); // no listener
System.Console.WriteLine("CREATE PUBLISHER -----------------");
PublisherQos pub_qos = null;
PublisherListener pub_listener = null;
Publisher pub = dp.create_publisher(pub_qos, pub_listener, 0);
System.Console.WriteLine("CREATE DATAWRITER ----------------");
DataWriterQos dw_qos = new DataWriterQos();
pub.get_default_datawriter_qos(dw_qos);
DataWriterListener dw_listener = null;
StringMsgDataWriter dw = (StringMsgDataWriter) pub.create_datawriter(top,
dw_qos,
dw_listener,
0);
Thread.Sleep(500);
while ( true ) {
StringMsg data = new StringMsg();
data.msg = "Hello WORLD from C#!";
System.Console.WriteLine("WRITE SAMPLE. ");
/* DDS.HANDLE_NIL says datawriter should compute handle */
retval = dw.write ( data, DDS.HANDLE_NIL );
if ( retval != ReturnCode_t.RETCODE_OK )
System.Console.WriteLine( " ==== DDS_DataWriter_write() error... ");
Thread.Sleep(1000); // 1 second sleep
}
}
};
file: hello_sub.cs
/****************************************************************
*
* file: hello_sub.cs
* desc: Provides a simple C# 'hello world' DDS subscriber.
* This publishing application will send data
* to the example 'hello world' subscribing
* application.
*
****************************************************************
*
* Coypright(C) 2009-2011 Twin Oaks Computing, Inc
* All rights reserved. Castle Rock, CO 80108
*
*****************************************************************
*
* This file is provided by Twin Oaks Computing, Inc
* as an example. It is provided in the hope that it will be
* useful but WITHOUT ANY WARRANTY; without even the implied
* warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
* PURPOSE. TOC Inc assumes no liability or responsibilty for
* the use of this information for any purpose.
*
****************************************************************/
using System;
using System.Runtime.InteropServices;
using System.Threading;
using System.Collections.Generic;
using com.toc.coredx.DDS;
public class hello_sub {
class TestDataReaderListener : DataReaderListener
{
public TestDataReaderListener()
{
this.on_requested_deadline_missed = requested_deadline_missed;
this.on_requested_incompatible_qos = requested_incompatible_qos;
this.on_sample_rejected = sample_rejected;
this.on_liveliness_changed = liveliness_changed;
this.on_data_available = data_available;
this.on_subscription_matched = subscription_matched;
this.on_sample_lost = sample_lost;
}
public void requested_deadline_missed(DataReader dr,
RequestedDeadlineMissedStatus status)
{
System.Console.WriteLine(" @@@@@@@@@@@ REQUESTED DEADLINE MISSED @@@@@");
System.Console.WriteLine(" @@@@@@@@@@@ @@@@@" );
System.Console.WriteLine(" @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@");
}
public void requested_incompatible_qos(DataReader dr,
RequestedIncompatibleQosStatus status)
{
System.Console.WriteLine(" @@@@@@@@@@@ REQUESTED INCOMPAT QOS @@@@@@@@");
System.Console.WriteLine(" @@@@@@@@@@@ dr = " + dr);
System.Console.WriteLine(" @@@@@@@@@@@ @@@@@@@@" );
System.Console.WriteLine(" @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@");
}
public void sample_rejected(DataReader dr,
SampleRejectedStatus status)
{
}
public void liveliness_changed(DataReader dr,
LivelinessChangedStatus status)
{
TopicDescription td = dr.get_topicdescription();
System.Console.WriteLine(" @@@@@@@@@@@ LIVELINESS CHANGED @@@@@@@@@@");
System.Console.WriteLine(" @@@@@@@@@@@ topic = " + td.get_name() + " (type: " + td.get_type_name() + ")");
System.Console.WriteLine(" @@@@@@@@@@@ change = " + status.alive_count_change);
System.Console.WriteLine(" @@@@@@@@@@@ current = " + status.alive_count);
System.Console.WriteLine(" @@@@@@@@@@@ @@@@@@@@@@" );
System.Console.WriteLine(" @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@");
}
public void subscription_matched(DataReader dr,
SubscriptionMatchedStatus status)
{
TopicDescription td = dr.get_topicdescription();
System.Console.WriteLine(" @@@@@@@@@@@ SUBSCRIPTION MATCHED @@@@@@@@@@");
System.Console.WriteLine(" @@@@@@@@@@@ topic = " + td.get_name() + " (type: " + td.get_type_name() + ")");
System.Console.WriteLine(" @@@@@@@@@@@ current = " + status.current_count);
System.Console.WriteLine(" @@@@@@@@@@@ @@@@@@@@@@" );
System.Console.WriteLine(" @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@");
}
public void sample_lost(DataReader dr,
SampleLostStatus status)
{
}
public void data_available(DataReader dr)
{
TopicDescription td = dr.get_topicdescription();
System.Console.WriteLine(" @@@@@@@@@@@ DATA AVAILABLE @@@@@@@@@@");
System.Console.WriteLine(" @@@@@@@@@@@ topic = " + td.get_name() + " (type: " + td.get_type_name() + ")");
StringMsgDataReader string_dr = (StringMsgDataReader)dr;
List samples = new List();
List si = new List();
ReturnCode_t retval = string_dr.take(samples, si, 100,
DDS.ANY_SAMPLE_STATE,
DDS.ANY_VIEW_STATE,
DDS.ANY_INSTANCE_STATE);
System.Console.WriteLine(" @@@@@@@@@@@ DR.read() ===> " + retval);
if (retval == ReturnCode_t.RETCODE_OK)
{
System.Console.WriteLine(" @@@@@@@@@@@ samples.Count= " + samples.Count);
for (int i = 0; i < samples.Count; i++)
{
System.Console.WriteLine(" State : " +
(si[i].instance_state ==
DDS.ALIVE_INSTANCE_STATE?"ALIVE":"NOT ALIVE") );
System.Console.WriteLine(" TimeStamp : " +
si[i].source_timestamp.sec + "." +
si[i].source_timestamp.nanosec);
System.Console.WriteLine(" Handle : " + si[i].instance_handle.value);
System.Console.WriteLine(" WriterHandle: " + si[i].publication_handle.value);
System.Console.WriteLine(" SampleRank : " + si[i].sample_rank);
if (si[i].valid_data)
System.Console.WriteLine(" msg : " + samples[i].msg);
}
string_dr.return_loan(samples, si);
}
System.Console.WriteLine(" @@@@@@@@@@@ @@@@@@@@@@" );
System.Console.WriteLine(" @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@");
}
}
// -----------------------------------------------------------------------
//
// -----------------------------------------------------------------------
public static void Main()
{
System.Console.WriteLine("STARTING -------------------------");
DomainParticipantFactory dpf = DomainParticipantFactory.get_instance();
DomainParticipant dp = null;
System.Console.WriteLine("CREATE PARTICIPANT ---------------");
dp = dpf.create_participant(0, /* domain Id */
DDS.PARTICIPANT_QOS_DEFAULT, /* default qos */
null, /* no listener */
0);
System.Console.WriteLine("REGISTERING TYPE -----------------");
ReturnCode_t retval = StringMsgTypeSupport.register_type(dp, null); //"StringMsg");
System.Console.WriteLine("CREATE TOPIC ---------------------");
Topic top = dp.create_topic("helloTopic",
StringMsgTypeSupport.get_type_name(),
DDS.TOPIC_QOS_DEFAULT,
null, 0); // no listener
DomainParticipantFactory dpf = DomainParticipantFactory.get_instance();
DomainParticipant dp = null;
System.Console.WriteLine("CREATE PARTICIPANT ---------------");
dp = dpf.create_participant(0, /* domain Id */
DDS.PARTICIPANT_QOS_DEFAULT, /* default qos */
null, /* no listener */
0);
System.Console.WriteLine("REGISTERING TYPE -----------------");
ReturnCode_t retval = StringMsgTypeSupport.register_type(dp, null); //"StringMsg");
System.Console.WriteLine("CREATE TOPIC ---------------------");
Topic top = dp.create_topic("helloTopic",
StringMsgTypeSupport.get_type_name(),
DDS.TOPIC_QOS_DEFAULT,
null, 0); // no listener
System.Console.WriteLine("CREATE SUBSCRIBER ----------------");
SubscriberQos sub_qos = null;
SubscriberListener sub_listener = null;
Subscriber sub = dp.create_subscriber(sub_qos, sub_listener, 0);
System.Console.WriteLine("CREATE DATAREADER ----------------");
DataReaderQos dr_qos = new DataReaderQos();
sub.get_default_datareader_qos(dr_qos);
dr_qos.history.depth = 10;
DataReaderListener dr_listener = new TestDataReaderListener();
StringMsgDataReader dr = (StringMsgDataReader) sub.create_datareader(top,
dr_qos,
dr_listener,
DDS.ALL_STATUS);
while ( true ) {
Thread.Sleep(5000); // 5 second sleep
}
}
};