In Java, the function Process.onExit() creates a CompletableFuture as exit handler and this is the enabling feature in Java to wait for any termination of a set of processes.

public Process anyProcTermination(List<Process> procs)  {
    CompletableFuture<Process>[] exitHandlers =
            procs.stream()
                    .map(p -> p.onExit())
                    .toArray(CompletableFuture[]::new);
    CompletableFuture<Object> exitHandle = CompletableFuture.anyOf(exitHandlers);
    return  (Process) exitHandle.join();
}