Module Await_kernel.Terminator

t is the type of termination tokens. Tokens become terminated by calls to Source.terminate.

is_terminated t is true if t has been terminated and false otherwise. Once is_terminated t is true it will never again become false.

same t1 t2 determines whether the tokens t1 and t2 are the one and the same.

never is a termination token that is never terminated

always is a termination token that is already terminated.

is_terminatable t is true if the token has an associated source and can be terminated through it and otherwise false.

source t returns the source of the termination token This t or Null in case the token is not terminatable.

with_ f creates a fresh termination token with an associated source and passes both to f. The token is terminated when Source.terminate has been called on the source.

Panics if t still has unsignaled attached triggers when f finishes.

with_linked t f creates a fresh termination token with an associated source and passes both to f. The token is terminated when either t is terminated or Source.terminate has been called on the source.

Panics if t still has unsignaled attached triggers when f finishes.

with_linked_multi ts f creates a fresh termination token with an associated source and passes them both to f. The token is canceled when any of ts are terminated or when Source.terminate has been called on the source.

Panics if t still has unsignaled attached triggers when f finishes.

add_trigger t s attaches s to the token t so that it will be signalled when t is terminated.

Returns

• Terminated if t was already terminated and so s was not attached to it,
• Signaled if s was already signaled and so wasn't attached to t, or
• Attached if t was not terminated and s was not signaled and so s has been attached to t.

add_trigger does not update the trigger s. In particular, a return value of Terminated tells nothing about the state of s.

cancellation t is the underlying cancellation token of the terminator t.

This allows turning termination into cancellation for the purpose of carefully handling resources in critical sections where implicit termination is not desired.