Class CancellationTokenSource

Add a cancellation handler function. The handler will be invoked synchronously if this.isCanceled === true. Otherwise, it will be invoked synchronously upon cancellation, unless it is removed prior to cancellation.

The handler function must not throw any exceptions when called.

Precondition

The handler function must not already be registered.

Returns

A function that unregisters the handler.

Trigger cancellation.

If this.isCanceled === false, then each registered cancellation handler is invoked synchronously.

Unregister a cancellation handler function. If this.isCanceled, or the specified handler function has not been registered, then this function has no effect.