Marks this operation as cancelled and notifies any waiters.
Marks this operation as completed and takes over the outcome of another TFuture of the same type.
Marks the operation as failed with the specified exception and notifies any waiters.
Sets the result of the operation, marks it as done, and notifies any waiters.
A TFuture covering the simple but common case where the result is simply set by a call to succeed()/fail().
All methods are thread-safe, but usually, succeed()/fail() are only called from a single thread (different from the thread(s) waiting for the result using the TFuture interface, though).