internal static void Start <TStateMachine>(ref TStateMachine stateMachine)
where TStateMachine : IAsyncStateMachine
{
// Async state machines are required not to throw, so no need for try/finally here.
Thread currentThread = Thread.CurrentThread;
ExecutionContextSwitcher ecs = default(ExecutionContextSwitcher);
ExecutionContext.EstablishCopyOnWriteScope(currentThread, ref ecs);
stateMachine.MoveNext();
ecs.Undo(currentThread);
}
public void Start <TStateMachine>(ref TStateMachine stateMachine) where TStateMachine : IAsyncStateMachine
{
if (stateMachine == null)
{
throw new ArgumentNullException("stateMachine");
}
ExecutionContextSwitcher executionContextSwitcher = default(ExecutionContextSwitcher);
RuntimeHelpers.PrepareConstrainedRegions();
try
{
ExecutionContext.EstablishCopyOnWriteScope(ref executionContextSwitcher);
stateMachine.MoveNext();
}
finally
{
executionContextSwitcher.Undo();
}
}
public void Start <TStateMachine>(ref TStateMachine stateMachine) where TStateMachine : IAsyncStateMachine
{
if (stateMachine == null) // TStateMachines are generally non-nullable value types, so this check will be elided
{
ThrowHelper.ThrowArgumentNullException(ExceptionArgument.stateMachine);
}
// Run the MoveNext method within a copy-on-write ExecutionContext scope.
// This allows us to undo any ExecutionContext changes made in MoveNext,
// so that they won't "leak" out of the first await.
Thread currentThread = Thread.CurrentThread;
ExecutionContextSwitcher ecs = default(ExecutionContextSwitcher);
try
{
ExecutionContext.EstablishCopyOnWriteScope(currentThread, ref ecs);
stateMachine.MoveNext();
}
finally
{
ecs.Undo(currentThread);
}
}
