379         self._p = subprocess.Popen(self.args, stdin=subprocess.PIPE,
383         out = self._p.stdout.read(9)
387             out += self._p.stdout.read()
388             self._p.wait(timeout=1)
392         self._p.communicate('q\n')
400             c = self._p.stdout.read(1)
416         self._p.stdin.write(cmd + '\n')
417         self._p.stdin.flush()
426     _p: 'Optional[subprocess.Popen[bytes]]' = None  variable in QemuStorageDaemon
443         self._p = subprocess.Popen(all_args)
447             if self._p.poll() is not None:
458         assert self._pid == self._p.pid
475         self._p.send_signal(kill_signal)
476         self._p.wait()
477         self._p = None
493         if self._p is not None: