built-in predicate
threaded_call/1-2
¶
Description¶
threaded_call(Goal)
threaded_call(Goal, Tag)
Proves Goal
asynchronously using a new thread. The argument can be a
message sending goal. Calls to this predicate always succeeds and return
immediately. The results (success, failure, or exception) are sent back
to the message queue of the object containing the call (this) and
can be retrieved by calling the
threaded_exit/1 predicate.
The threaded_call/2
variant returns a threaded call identifier tag that
can be used with the threaded_exit/2
and threaded_cancel/1 predicates. Tags shall be regarded
as opaque terms; users shall not rely on its type.
Note
This predicate requires a backend Prolog compiler providing
compatible multi-threading primitives. The value of the read-only
threads flag is set to supported
when that
is the case.
Modes and number of proofs¶
threaded_call(@callable) - one
threaded_call(@callable, --nonvar) - one
Errors¶
Goal
is a variable:instantiation_error
Goal
is neither a variable nor a callable term:type_error(callable, Goal)
Tag
is not a variable:type_error(variable, Goal)
Examples¶
Goal
asynchronously in a new thread:threaded_call(Goal)
::Message
asynchronously in a new thread:threaded_call(::Message)
Object::Message
asynchronously in a new thread:threaded_call(Object::Message)