This function allocates Intel® Cilk™ Plus data structures, starting the runtime. This function is documented for completeness; it should never be necessary to call this function explicitly, as the runtime system calls it automatically when needed (for example, to execute the first
cilk_for in a program).
Even if you properly use a lock to protect a resource (such as a simple variable or a list or other data structure), the actual order that two strands modify the resource is not deterministic. For example, suppose the following code fragment is part of a function that is spawned, so that several strands may be executing the code in parallel.