/// <summary>
/// An internal constructor used by the factory methods on task and its descendent(s).
/// This variant does not capture the ExecutionContext; it is up to the caller to do that.
/// </summary>
/// <param name="action">An action to execute.</param>
/// <param name="state">Optional state to pass to the action.</param>
/// <param name="parent">Parent of Task.</param>
/// <param name="cancellationToken">A CancellationToken for the task.</param>
/// <param name="scheduler">A task scheduler under which the task will run.</param>
/// <param name="creationOptions">Options to control its execution.</param>
/// <param name="internalOptions">Internal options to control its execution</param>
internal Task(Delegate action, object state, Task parent, CancellationToken cancellationToken, TaskCreationOptions creationOptions, InternalTaskOptions internalOptions, TaskScheduler scheduler)
{
if (action == null)
{
throw new ArgumentNullException("action");
}
if (ReferenceEquals(scheduler, null))
{
throw new ArgumentNullException("scheduler");
}
Contract.EndContractBlock();
// This is readonly, and so must be set in the constructor
// Keep a link to your parent if: (A) You are attached, or (B) you are self-replicating.
if
(
((creationOptions & TaskCreationOptions.AttachedToParent) != 0) ||
((internalOptions & InternalTaskOptions.SelfReplicating) != 0)
)
{
_parent = parent;
}
_id = Interlocked.Increment(ref _lastId) - 1;
_status = (int)TaskStatus.Created;
if
(
_parent != null &&
((creationOptions & TaskCreationOptions.AttachedToParent) != 0) &&
((_parent.CreationOptions & TaskCreationOptions.DenyChildAttach) == 0)
)
{
_parent.AddNewChild();
}
Action = action;
State = state;
ExecutingTaskScheduler = scheduler;
_waitHandle = new ManualResetEventSlim(false);
if ((creationOptions &
~(TaskCreationOptions.AttachedToParent |
TaskCreationOptions.LongRunning |
TaskCreationOptions.DenyChildAttach |
TaskCreationOptions.HideScheduler |
TaskCreationOptions.PreferFairness |
TaskCreationOptions.RunContinuationsAsynchronously)) != 0)
{
throw new ArgumentOutOfRangeException("creationOptions");
}
// Throw exception if the user specifies both LongRunning and SelfReplicating
if (((creationOptions & TaskCreationOptions.LongRunning) != 0) &&
((internalOptions & InternalTaskOptions.SelfReplicating) != 0))
{
throw new InvalidOperationException("An attempt was made to create a LongRunning SelfReplicating task.");
}
if ((internalOptions & InternalTaskOptions.ContinuationTask) != 0)
{
// For continuation tasks or TaskCompletionSource.Tasks, begin life in the
// WaitingForActivation state rather than the Created state.
_status = (int)TaskStatus.WaitingForActivation;
}
_creationOptions = creationOptions;
_internalOptions = internalOptions;
// if we have a non-null cancellationToken, allocate the contingent properties to save it
// we need to do this as the very last thing in the construction path, because the CT registration could modify m_stateFlags
if (cancellationToken.CanBeCanceled)
{
AssignCancellationToken(cancellationToken, null, null);
}
}