Icicle\Concurrent\Process\Process::kill PHP Method

    public function kill()
    {
        if (is_resource($this->process)) {
            // Forcefully kill the process using SIGKILL.
            proc_terminate($this->process, 9);
            // "Detach" from the process and let it die asynchronously.
            $this->process = null;
        }
    }

 /**
  * {@inheritdoc}
  */
 public function kill()
 {
     $this->process->kill();
     $this->channel = null;
 }