Fork/join blocks provide the primary mechanism for creating concurrent processes.The all | any | none options specify when the code after the fork/join block executes.The default is all.
all :: The default is all. Code after the block executes after all of the concurrent processes are completed.
any :: When any is used, code after the block executes after any single concurrent process is completed.
none :: When none is used, code after the block executes immediately, without waiting for any of the processes to complete.