First-class synchronous communication.
This module implements synchronous inter-thread communications over channels. As in John Reppy's Concurrent ML system, the communication events are first-class values: they can be built and combined independently before being offered for communication.
val new_channel : unit -> 'a channel
Return a new channel.
send ch v returns the event consisting in sending the value
v over the channel
ch. The result value of this event is
receive ch returns the event consisting in receiving a value from the channel
ch. The result value of this event is the value received.
val always : 'a -> 'a event
always v returns an event that is always ready for synchronization. The result value of this event is
choose evl returns the event that is the alternative of all the events in the list
wrap ev fn returns the event that performs the same communications as
ev, then applies the post-processing function
fn on the return value.
wrap_abort ev fn returns the event that performs the same communications as
ev, but if it is not selected the function
fn is called after the synchronization.
guard fn returns the event that, when synchronized, computes
fn() and behaves as the resulting event. This allows events with side-effects to be computed at the time of the synchronization operation.
val sync : 'a event -> 'a
``Synchronize'' on an event: offer all the communication possibilities specified in the event to the outside world, and block until one of the communications succeed. The result value of that communication is returned.
val select : 'a event list -> 'a
``Synchronize'' on an alternative of events.
select evl is shorthand for
val poll : 'a event -> 'a option
Non-blocking version of
Event.sync: offer all the communication possibilities specified in the event to the outside world, and if one can take place immediately, perform it and return
Some r where
r is the result value of that communication. Otherwise, return
None without blocking.