Synopsis

:- use_module(library(spawn)).

retirement(EmployeeId,Name,HireDate) :-
    % start long-running computations in the background
    spawn(query_company_ldap(EmployeeId,Employee)),
    spawn(query_hr_database(EmployeeId,Job)),

    do_something_productive_while_waiting,

    % extract desired details from Employee and Job
    % (blocks until background computations are done)
    Employee = employee(Name,_,_),
    Job = job(_,HireDate,_).

some_numbers(PiN,Rand) :-
    % start long-running computations in the background
    async(calculate_nth_digit_of_pi(21_734,PiN),PiToken),
    async(ask_randomorg_for_a_number(Rand), RandToken),

    % explicitly block until they're done
    await(PiToken),
    writeln(PiN),   % now it has a value
    await(RandToken),
    writeln(Rand).  % now it has a value too

Description

SWI Prolog has great concurrency primitives. For some common operations, those primitives are too low level. You end up reading through a lot of message queue and threading boilerplate code. This library provides high level concurrency predicates which handle all the messy details.

Our aim is to make this library as easy to use as call/1.

Changes in this Version

• First public release

Installation

Using SWI-Prolog 6.3 or later:

?- pack_install(spawn).

This module uses semantic versioning.

Source code available and pull requests accepted at http://github.com/mndrix/spawn

@author Michael Hendricks michael@ndrix.org @license unlicense