Thread-launched running processes won't destroy (Java)

Question

Starting multiple threads and having each exec() then destroy() a running java process result in some of the process not being destroyed and still running after program exit. He

Answer 1

I had a very similar issue and the problem with destroy() not working was manifesting even with a single thread.

Process process = processBuilder(ForeverRunningMain.class).start()
long endTime = System.currentTimeMillis() + TIMEOUT_MS; 
while (System.currentTimeMillis() < endTime) {
    sleep(50);
}
process.destroy();

The process was not always destroyed if TIMEOUT_MS was too low. Adding an additional sleep() before destroy() fixed it (even though I don't have an explanation why):

Thread.sleep(300);
process.destroy();