Run several ant tasks on the same VM

Question

I'm running unit test using ant

<target name="test" depends="tomcatDeploy" description="Build and run tests">
    <ant dir="${aDir}" target="test"/>
    <ant dir="${bDir}" target="test"/>
    <ant dir="${cDir}" target="test"/>
    <ant dir="${dDir}/ExtFramework"  target="test"/>
</target>

and I want to run them all on the same VM - otherwise I get a lot of overhead in the creation of the jvm & re-creation of statics and so forth.

Is there a way to do this?

Answer 1

The task by itself doesn't create a new VM. Are your tests creating a new VM?

Answer 2

I think the subant task is what you're looking for. Assuming all of your subdirectories have a common parent, you can do something like the following:

<target name="test" depends="tomcatDeploy" description="Build and run tests">
    <subant target="test">
        <fileset dir="${parent}" includes="**/build.xml"/>
    </subant>
</target>

EDIT How are you running the tests? If you are using the junit task, do you have fork="yes"? If so, that will run the tests in a new VM. Change that to fork="no" to run the tests in the same VM.

Answer 3

Try to minimize the problem: Does your test create a new VM if you start it manually via JUnit? Or does the problem only occur in combination with ant?
Probably it's JUnit or your tests creating a new VM and leak memory.

Answer 4

<parallel threadCount='4'>
  <ant target='TargetThatConsumesLotsOfCPUTimeAndMemory'>
    <param name='file' value='one.txt'/>
  </ant>
  <ant target='TargetThatConsumesLotsOfCPUTimeAndMemory'>
    <param name='file' value='two.txt'/>

  </ant>
  <ant target='TargetThatConsumesLotsOfCPUTimeAndMemory'>
    <param name='file' value='three.txt'/>
  </ant>
  <!-- repeated about 40 times -->
</parallel>

http://www.java-tips.org/other-api-tips/ant/how-to-use-parallel-task.html