`parallel-execute``p1``p2``...`procedureEach argument must be a procedure of no arguments.

`parallel-execute`creates a separate process for each argument, and that process applies the argument to no arguments. These processes all run concurrently.See SICP Section 3.4.2, Subsection "Serializers in Scheme".

Example:

(import (srfi 216)) (define x 10) (parallel-execute (lambda () (set! x (* x x))) ; P1 (lambda () (set! x (+ x 1)))) ; P2 ;; May assign to x any of the following: ;; 101 - P1 sets x to 100 and then P2 increments x to 101. ;; 121 - P2 increments x to 11 and then P1 sets x to x * x. ;; 110 - P2 changes x from 10 to 11 between the two times that P1 accesses the value of x during the evaluation of (* x x). ;; 11 - P2 accesses x, then P1 sets x to 100, then P2 sets x. ;; 100 - P1 accesses x (twice), then P2 sets x to 11, then P 1 sets x.