Succeeds with exit code of the process or fails if the process is killed. */ public function join(ProcessHandle $handle): Promise; /** * Forcibly end the child process. * * @param ProcessHandle $handle The process descriptor. * * @throws ProcessException If terminating the process fails. */ public function kill(ProcessHandle $handle); /** * Send a signal signal to the child process * * @param ProcessHandle $handle The process descriptor. * @param int $signo Signal number to send to process. * * @throws ProcessException If sending the signal fails. */ public function signal(ProcessHandle $handle, int $signo); /** * Release all resources held by the process handle. * * @param ProcessHandle $handle The process descriptor. */ public function destroy(ProcessHandle $handle); }