SWI-Prolog -- concurrent

Documentation
- Reference manual
  - The SWI-Prolog library
    - library(thread): High level thread primitives
- Packages

Availability::- use_module(library(thread)).(can be autoloaded)

[semidet]concurrent_maplist(:Goal, +List)

[semidet]concurrent_maplist(:Goal, +List1, +List2)

[semidet]concurrent_maplist(:Goal, +List1, +List2, +List3)

Concurrent version of maplist/2. This predicate uses concurrent/3, using multiple worker threads. The number of threads is the minimum of the list length and the number of cores available. The number of cores is determined using the prolog flag cpu_count. If this flag is absent or 1 or List has less than two elements, this predicate calls the corresponding maplist/N version using a wrapper based on once/1. Note that all goals are executed as if wrapped in once/1 and therefore these predicates are semidet.

Note that the the overhead of this predicate is considerable and therefore Goal must be fairly expensive before one reaches a speedup.