Module Await_kernel.Await

Terminated is an exception indicating that an operation has been terminated.

t is the type of implementations of awaiting. Operations that need to await something take a t that provides an implementation of awaiting for them to use.

Any awaiting operation can be terminated by the awaiting implementation, which results in a Terminated exception being raised.

with_ terminator ~yield ~await c ~f calls f with an awaiter that has terminator as its terminator, yield c as its implementation of yield, and await c as its implementation of await.

create_global ~terminator ~yield ~await c creates a global awaiter with yield c as its implementation of yield and await c as its implementation of await. Both yield and await must be portable as the returned Await.t is not local, allowing it to escape to other capsules.

terminator t is the terminator associated with t. Awaiting operations should attempt to cancel themselves if they have been terminated, raising Terminated if they succeed in doing so.

await t ~on_terminate ~await_on will use t to attach on_terminate to be signalled on termination and to wait until await_on has been signaled.

Note that the on_terminate trigger may not be used by await. The await_on trigger will be used before await returns.

await_until_terminated t trigger is equivalent to await t ~on_terminate:(Trigger.source trigger) ~await_on:trigger.

await_until_terminated_or_canceled t c trigger is like await_until_terminated t trigger except it will also return in case the cancellation token has been cancelled .

await_with_terminate t trigger ~terminate r will attach a trigger to call terminate r to the terminator of t and wait until trigger has been signalled.

await_with_terminate_or_cancel t c trigger ~terminate_or_cancel r will attach a trigger to call terminate_or_cancel r to both the terminator of t and to the given cancellation token c and then wait until trigger has been signalled.

is_terminated t is Terminator.is_terminated (terminator t).

with_terminator t new_terminator is an awaiter u like t where terminator u is new_terminator.

The main use case of with_terminator is to protect a blocking operation from being terminated by replacing the terminator with Terminator.never:

  blocking_operation (with_terminator t Terminator.never)

await_never_terminated t trigger is await_until_terminated (with_terminator t Terminator.never) trigger.

yield t yields to the scheduler using the implementation of yielding associated with t.

• raises [Terminated]

  if the terminator associated with t has been terminated.