|Maintainer||Bas van Dijk <email@example.com> , Roel van Dijk <firstname.lastname@example.org>|
An Event is a simple mechanism for communication between threads: one thread signals an event and other threads wait for it.
An event has a state which is either "set" or "cleared". This state can
be changed with the corresponding functions
function blocks until the state is "set". An important property of setting
an event is that all threads waiting for it are woken.
It was inspired by the Python
Event object. See:
This module is designed to be imported qualified. We suggest importing it like:
import Control.Concurrent.Event ( Event ) import qualified Control.Concurrent.Event as Event ( ... )
An event is in one of two possible states: "set" or "cleared".
Waiting for events
Block until the event is
set or until a timer expires.
The timeout is specified in microseconds.
If the event is "cleared" and a timeout of 0 μs is specified the
False without blocking.
Negative timeouts are treated the same as a timeout of 0 μs.
Changes the state of the event to "set". All threads that where waiting
for this event are woken. Threads that
wait after the state is changed to
"set" will not block at all.