The Increment application is a Java application that increases N times three different counters. Each increase step is developed by a separated task. The purpose of this application is to show parallelism between the three counters.

Next we provide the main code of this application. The code inside the increment task is the same than the previous example.

// increment.Increment

public static void main(String[] args) throws Exception {
        // Check and get parameters
        if (args.length != 4) {
                throw new Exception("[ERROR] Incorrect number of parameters");
        int N = Integer.parseInt(args[0]);
        int counter1 = Integer.parseInt(args[1]);
        int counter2 = Integer.parseInt(args[2]);
        int counter3 = Integer.parseInt(args[3]);

        // Initialize counter files
        System.out.println("Initial counter values:");
        initializeCounters(counter1, counter2, counter3);

        // Print initial counters state

        // Execute increment tasks
        for (int i = 0; i < N; ++i) {

        // Print final counters state (sync)
        System.out.println("Final counter values:");

As shown in the main code, this application has 4 parameters that stand for:

  1. N: Number of times to increase a counter

  2. InitialValue1: Initial value for counter 1

  3. InitialValue2: Initial value for counter 2

  4. InitialValue3: Initial value for counter 3

Next we will compile and run the Increment application with the -g option to be able to generate the final graph at the end of the execution.

compss@bsc:~$ cd ~/tutorial_apps/java/increment/src/main/java/increment/
compss@bsc:~/tutorial_apps/java/increment/src/main/java/increment$ javac *.java
compss@bsc:~/tutorial_apps/java/increment/src/main/java/increment$ cd ..
compss@bsc:~/tutorial_apps/java/increment/src/main/java$ jar cf increment.jar increment
compss@bsc:~/tutorial_apps/java/increment/src/main/java$ mv increment.jar ~/tutorial_apps/java/increment/jar/

compss@bsc:~$ cd ~/tutorial_apps/java/increment/jar
compss@bsc:~/tutorial_apps/java/increment/jar$ runcompss -g increment.Increment 10 1 2 3
[  INFO] Using default execution type: compss
[  INFO] Using default location for project file: /opt/COMPSs/Runtime/configuration/xml/projects/default_project.xml
[  INFO] Using default location for resources file: /opt/COMPSs/Runtime/configuration/xml/resources/default_resources.xml

----------------- Executing increment.Increment --------------------------

WARNING: COMPSs Properties file is null. Setting default values
[(1028)    API]  -  Starting COMPSs Runtime v<version>
Initial counter values:
- Counter1 value is 1
- Counter2 value is 2
- Counter3 value is 3
Final counter values:
- Counter1 value is 11
- Counter2 value is 12
- Counter3 value is 13
[(4403)    API]  -  Execution Finished


By running the compss_gengraph command users can obtain the task graph of the above execution. Next we provide the set of commands to obtain the graph show in Figure 57.

compss@bsc:~$ cd ~/.COMPSs/increment.Increment_01/monitor/
compss@bsc:~/.COMPSs/increment.Increment_01/monitor$ compss_gengraph
compss@bsc:~/.COMPSs/increment.Increment_01/monitor$ evince complete_graph.pdf
Java increment tasks graph

Figure 57 Java increment tasks graph