MSBuild CallTargetsParallel

This is an MSBuild task to invoke multiple targets in parallel. It invokes a new instance of msbuild for each target.

Use

Simple target invocation

A simple use is:

<CallTargetsParallel Targets="Target1;Target2" GlobalProperties="PropertyName1;PropertyName2" />

Runs Target1 and Target2 in this project file, passing along the current values of the properties PropertyName1 and PropertyName2.

Installation

Include the CallTargetsParallel.tasks file somewhere in your project, then in the MSBuild file include the line:

<Import Project="CallTargetsParallel.tasks"/>

All features

<ItemGroup>
    <ParallelTargets Include="_global">
        <Property1>value1</Property1>
    </ParallelTargets>
    <ParallelTargets Include="Target1">
        <Property2>value2</Property2> 
    </ParallelTargets>
    <ParallelTargets Include="TargetTwo">
        <Targets>Target2</Targets>
        <Property1>some "value"</Property1>
    </ParallelTargets>
    <ParallelTargets Include="DualExample">
        <Targets>Target1;Target2</Targets>
    </ParallelTargets>
    <ParallelTargets Include="OtherProject">
        <MSBuildFile>myproject.proj</MSBuildFile>
        <Targets>Build</Targets>
        <Property3>$(Property3)</Property3>
    </ParallelTargets>
</ItemGroup>
<CallTargetsParallel Targets="@(ParallelTargets)" GlobalProperties="Property5" />

This will invoke 4 msbuild instances in parallel:

• instance "Target1" will run target Target1, with values Property1=value1, Property2=value2, and Property5 (defined elsewhere)
• instance "TargetTwo" will run target Target2, with values Property1=some "value", and Property5 (defined elsewhere)
• instance "DualExample" will run targets Target1 and Target2, with values Property1=value1, and Property5 (defined elsewhere)
• instance "OtherProject" will run the Build target in myproject.proj, with the current values of Property3 and Property5 (both defined elsehwhere)

Item definitions:

• Include= must have a unique name in the group
• The name "_global" is reserved to define property values that apply to all other items in the group. No targets will be run even if specified.
• The metadata in each include are used as property names, and they cannot be MSBuild reserved names (http://msdn.microsoft.com/en-us/library/ms164313.aspx)
• The metadata item specifies which target(s) to actually invoke. If not specified, the item name (Include= value) is used
• The metadata item specifies which msbuild project file to run. If not specified, the current file is used.

Limitations:

• Property values defined in the target where is invoked cannot be passed. Use DependsOnTargets if other targets need to be called to set property values.

Inspiration

It's quite similar to the MSBuildExtensionPack Parallel task (http://www.msbuildextensionpack.com/help/4.0.8.0/html/23e4198a-c266-e8a3-4aea-7cf131a0837c.htm) but differs in the way it is invoked, making it significantly easier to pass existing properties without worrying about escaping values for command-line execution. I wrote this because I was trying to use parallel tasks in a complex project, and MSBuildExtensionPack's implementation meant I had giant easy-to-mess-up blocks of parameters to be passed to each invocation, and it quickly became unreadable.

License

"New" BSD: http://opensource.org/licenses/bsd-license.php