module Event:sig
..end
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.
type 'a
channel
'a
.val new_channel : unit -> 'a channel
type +'a
event
'a
.val send : 'a channel -> 'a -> unit event
send ch v
returns the event consisting in sending the value v
over the channel ch
. The result value of this event is ()
.val receive : 'a channel -> 'a event
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 v
.val choose : 'a event list -> 'a event
choose evl
returns the event that is the alternative of
all the events in the list evl
.val wrap : 'a event -> ('a -> 'b) -> 'b event
wrap ev fn
returns the event that performs the same communications
as ev
, then applies the post-processing function fn
on the return value.val wrap_abort : 'a event -> (unit -> unit) -> 'a event
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.val guard : (unit -> 'a event) -> 'a event
guard fn
returns the event that, when synchronized, computes
fn()
and behaves as the resulting event. This allows to
compute events with side-effects at the time of the synchronization
operation.val sync : 'a event -> 'a
val select : 'a event list -> 'a
select evl
is shorthand for sync(choose evl)
.val poll : 'a event -> 'a option
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.