/// <summary>
/// Cleans up any context or state that may have been built up for a given task.
/// </summary>
/// <param name="task">The task to clean up.</param>
/// <remarks>
/// For many factories, this method is a no-op. But some factories may have built up
/// an AppDomain as part of an individual task instance, and this is their opportunity
/// to shutdown the AppDomain.
/// </remarks>
public void CleanupTask(ITask task)
{
ErrorUtilities.VerifyThrowArgumentNull(task, "task");
AppDomain appDomain;
if (_tasksAndAppDomains.TryGetValue(task, out appDomain))
{
_tasksAndAppDomains.Remove(task);
if (appDomain != null)
{
// Unload the AppDomain asynchronously to avoid a deadlock that can happen because
// AppDomain.Unload blocks for the process's one Finalizer thread to finalize all
// objects. Some objects are RCWs for STA COM objects and as such would need the
// VS main thread to be processing messages in order to finalize. But if the main thread
// is blocked in a non-pumping wait waiting for this build request to complete, we would
// deadlock. By unloading asynchronously, the AppDomain unload can block till the main
// thread is available, even if it isn't available until after this MSBuild Task has
// finished executing.
Task.Run(() => AppDomain.Unload(appDomain));
}
}
TaskHostTask taskAsTaskHostTask = task as TaskHostTask;
if (taskAsTaskHostTask != null)
{
taskAsTaskHostTask.Cleanup();
}
else
{
// It's really not necessary to do it for TaskHostTasks
TaskLoader.RemoveAssemblyResolver();
}
}
/// <summary>
/// This is responsible for cleaning up the task after the OutOfProcTaskHostNode has gathered everything it needs from this execution
/// For example: We will need to hold on new AppDomains created until we finish getting all outputs from the task
/// Add any other cleanup tasks here. Any method calling ExecuteTask must remember to call CleanupTask.
/// </summary>
internal void CleanupTask()
{
if (_taskAppDomain != null)
{
AppDomain.Unload(_taskAppDomain);
}
TaskLoader.RemoveAssemblyResolver();
_wrappedTask = null;
}
/// <summary>
/// This is responsible for cleaning up the task after the OutOfProcTaskHostNode has gathered everything it needs from this execution
/// For example: We will need to hold on new AppDomains created until we finish getting all outputs from the task
/// Add any other cleanup tasks here. Any method calling ExecuteTask must remember to call CleanupTask.
/// </summary>
internal void CleanupTask()
{
#if FEATURE_APPDOMAIN
if (_taskAppDomain != null)
{
AppDomain.Unload(_taskAppDomain);
}
TaskLoader.RemoveAssemblyResolver();
#endif
wrappedTask = null;
}