Feb 18, 2009

The Standard C++ PSM for DDS on SourceForge

Hello,

I've recently started CZed a SourceForge project that will provide the reference Standard C++ PSM for DDS. The project page is available here, while the Subversion repository can be navigated from here. The current version of the API is not complete but the bulk of it is in place.

The main idea behind CZed is to have a working C++ PSM before the actual recommendation of the standard takes place. This will ensure that as many people as possible will have experimented the API and feed back comments thus increasing the likelihood that the API is very successful. Thus, take a look at the API and drop me questions, comments, or ideas.

Cheers,
@ngelo

Feb 5, 2009

Choosing OpenSplice DDS

Yesterday I gave a webcast, now available here, which first goes through the strategic, technical, and financial reasons for moving to OpenSplice DDS, and then shows some migration use cases as well as migration tactics.
Strategic vs Tactical Perspective
One of the key point I made in the first part of the webcast was trying to ensure that people look at Open Source in from a strategic as opposed to tactical perspective. In essence, now that OpenSplice DDS is Open Source many people will just see it as a cost effective manner of procuring the best DDS implementation available on the market. This perspective, although correct, is tactical and misses the strategic implication of Open Source, which if properly exploited are those that will bring the highest benefits.

An example, Open Source is a key element in enabling and catalyzing lead-user innovation; some visionary companies in domains characterized by lead-users innovations, such as Aerospace and Defense, have already realized and mastered the strategic relevance of Open Source. Other company are starting to understand its potential and are quickly embracing the new way.

Embracing OpenSplice DDS

The second part of the webcast, focused on showing some use cases motivating a move to OpenSplice DDS. For instance, I showed how OpenSplice DDS can be used to scale-out a data tier by either completely replacing a DBMS, or by offloading or fully federating the DBMS. I also showed how OpenSplice DDS can be used to replace another DDS implementation of yet another pub/sub technology.

From DDS-XYZ to OpenSplice DDS
Finally, one of the topic covered on the webcast was how to actually port applications developed on a DDS-XYZ to OpenSplice DDS. As explained in the webcast this is typically just an exercise of finding and removing calls to proprietary API that might be required by DDS-XYZ. Indeed, as shown by the example below, OpenSplice DDS does not require the use of any custom API for configuring transport or anything else. Configuration completely taken care by external tools. Below is an example that shows the code necessary to write a publisher for a TempSensor Topic.

// -- IDL --
module demo {
module tc {

struct TempSensor {
long tID;
float temp;
float humidity;
};
#pragma keylist TempSensor tID
};
};

// -- Publisher Implementation --

package demo.tc;

import DDS.*;

public class TempSensorApp {

static final String PARTITION = "SensorData";

public static void main(String[] args) {

if (args.length <> ");
System.exit(-1);
}

int tid = Integer.parseInt(args[0]);
int samples = Integer.parseInt(args[1]);

DomainParticipantFactory dpf =
DomainParticipantFactory.get_instance();

/**
* Create Domain Participant
**/
DomainParticipant part =
dpf.create_participant(null,
PARTICIPANT_QOS_DEFAULT.value,
null,
ANY_STATUS.value);

/**
* Regiter Type Support for TempSensor
**/
TempSensorTypeSupport tempSensorTS = new TempSensorTypeSupport();
String tempSensorTN = tempSensorTS.get_type_name();
tempSensorTS.register_type(part, tempSensorTN);

/**
* Create the TempSensor Topic
**/
TopicQosHolder topicQoS = new TopicQosHolder();
part.get_default_topic_qos(topicQoS);
Topic tempSensorTopic = part.create_topic("Demo_TempSensor",
tempSensorTN,
topicQoS.value,
null,
ANY_STATUS.value);


/**
* Create a Publisher
**/
PublisherQosHolder pubQoS = new PublisherQosHolder();
part.get_default_publisher_qos(pubQoS);
pubQoS.value.partition.name = new String[1];
pubQoS.value.partition.name[0] = PARTITION;

Publisher pub =
part.create_publisher(pubQoS.value, null, ANY_STATUS.value);

/**
* Create a Writer
**/
DataWriter writer =
pub.create_datawriter(tempSensorTopic,
DATAWRITER_QOS_USE_TOPIC_QOS.value,
null,
ANY_STATUS.value);

TempSensorDataWriter tempWriter =
TempSensorDataWriterHelper.narrow(writer);

/**
* Register Instance
**/
TempSensor temp = new TempSensor();
temp.tID = tid;

long handle = tempWriter.register_instance(temp);

/**
* Write Sample
**/
temp.temp = 12.1F;
temp.humidity = 0.45F;

for (int i = 0; i <> Temperature = " + temp.temp
+ " - Humidity = " + temp.humidity);

try {
Thread.sleep(1000);
}
catch (InterruptedException e) { }
temp.temp += 0.1;
temp.humidity += 0.01;
}

/**
* Cleanup
**/
tempWriter.dispose(temp, handle);
tempWriter.unregister_instance(temp, handle);

pub.delete_datawriter(tempWriter);

part.delete_publisher(pub);

dpf.delete_participant(part);
}
}

Feb 2, 2009

Sharing Slides

Hello All,

I've just signed up with slideshare.com and from now on most of the slides on DDS or OpenSplice DDS will be available here . For the time being I've uploaded the presentation that explains the vision behind the Open Source launch of OpenSplice DDS, and which also covers the new product structure.

Below is also a neat widget that can be used to check out the various slides I'll be uploading.

Ciao,
@ngelo