
parallel +SpecList

   Declares the procedure(s) specified by SpecList as parallel.



Arguments
   SpecList            Comma-separated sequence of expressions of the form Atom/Integer.

Type
   Predicate Database and Compiler

Description
   The parallel annotation specifies that the system is allowed to execute
   the clauses of the annotated predicate in parallel (Or-parallelism),
   instead of sequentially by backtracking.  This has the following
   consequences:


  * the predicate is a source of or-parallelism which will hopefully speed
    up execution of the program on a parallel machine


  * calls to this predicate may return alternative solutions in
    unpredictable order


  * side effects within the parallel execution may happen in unpredictable
    order


   The parallel annotation has simply no effect when the predicate (or a
   particular call to it) is deterministic or when it is used with a
   sequential ECLiPSe system.


   A procedure can be declared parallel before it is actually defined.




Modes and Determinism
   parallel(++) is det

Modules
   This predicate is sensitive to its module context (tool predicate, see @/2).

Exceptions
     4 --- SpecList is not instantiated.
     5 --- SpecList is instantiated, but not to a sequence of    expressions of the form Atom/Integer.

Examples
   
  [eclipse 1]: [user].
   :- parallel p/1.
   p(a).  p(b).  p(c).
  user       compiled traceable 220 bytes in 0.02 seconds
  yes.
  [eclipse 2]: get_flag(p/1, parallel, Flag).
  Flag = on
  yes.
  [eclipse 3]: p(X), use(X).
  % The three clauses of p/1 as well as the resulting goals
  % use(a), use(b) and use(c) may be executed in parallel!






See Also
   compile / 1, get_flag / 3, set_flag / 3
