dependent target getting excecute multiple times in a parallel target call

问题

i want to run few targets of ANT build in parallel. here is the code i tried

<project name="cis" default="release">

    <property name="Run_excecuted" value="false"/> 

    <target name="run_main">
        <sequential>
            <parallel> 
                <antcall target="dashboard" /> 
                <antcall target="remTraces" /> 
                <param name="Run_excecuted" value="true"/> 
            </parallel> 
        </sequential> 
    </target> 

I have set a property Run_excecuted in the build and have added the condition unless="Run_excecuted" in the required targets

<target name="dashboard" depends="prepare" unless="Run_excecuted">
<target name="remTraces" depends="prepare" unless="Run_excecuted"> 

what is happening is the antcalls are getting invoked in separate instances parallely and the dependencies are getting calculated again. Because of this target "prepare" is running multiple times. i dont want this to happen.How can i do this? property Run_excecuted being set is not helping.

来源：https://stackoverflow.com/questions/19677381/dependent-target-getting-excecute-multiple-times-in-a-parallel-target-call