test_subprocess.py 文件源码

def test_leak_fast_process_del_killed(self):
        # Issue #12650: on Unix, if Popen.__del__() was called before the
        # process exited, and the process got killed by a signal, it would never
        # be removed from subprocess._active, which triggered a FD and memory
        # leak.
        # spawn a Popen, delete its reference and kill it
        p = subprocess.Popen([sys.executable, "-c",
                              'import time;'
                              'time.sleep(3)'],
                             stdout=subprocess.PIPE,
                             stderr=subprocess.PIPE)
        self.addCleanup(p.stdout.close)
        self.addCleanup(p.stderr.close)
        ident = id(p)
        pid = p.pid
        del p
        os.kill(pid, signal.SIGKILL)
        # check that p is in the active processes list
        self.assertIn(ident, [id(o) for o in subprocess._active])

        # let some time for the process to exit, and create a new Popen: this
        # should trigger the wait() of p
        time.sleep(0.2)
        with self.assertRaises(EnvironmentError) as c:
            with subprocess.Popen(['nonexisting_i_hope'],
                                  stdout=subprocess.PIPE,
                                  stderr=subprocess.PIPE) as proc:
                pass
        # p should have been wait()ed on, and removed from the _active list
        self.assertRaises(OSError, os.waitpid, pid, 0)
        self.assertNotIn(ident, [id(o) for o in subprocess._active])