This is done primarily to avoid the 'bare except' pattern, which suppresses ALL exceptions and not just ones that we are anticipating to see.
Replace this with a pattern that isolates the different kind of shutdown paradigms and a new fallback shutdown handler that gracefully attempts one before the other. Move all of the post-shutdown code into _post_shutdown, and adjust the main shutdown() function to ALWAYS call the post_shutdown logic no matter what kind of error we encountered: An expected one (subprocess wait timeout) or an unexpected one (Everything else). In cases where we encounter an expected error in the graceful shutdown timeout, we will not re-raise an exception above shutdown(). Otherwise, after post_shutdown cleanup, we will. I anticipate that this WILL lead to additional bug reports filed against this module, but that is unfortunately somewhat the point: This code shouldn't be hiding failures that exist elsewhere within the python code. Signed-off-by: John Snow <js...@redhat.com> --- python/qemu/machine.py | 93 +++++++++++++++++++++++++++++------------- 1 file changed, 65 insertions(+), 28 deletions(-) diff --git a/python/qemu/machine.py b/python/qemu/machine.py index 041c615052e..a2abd2c35e3 100644 --- a/python/qemu/machine.py +++ b/python/qemu/machine.py @@ -283,6 +283,8 @@ def _post_launch(self): self._qmp.accept() def _post_shutdown(self): + self._load_io_log() + if self._qemu_log_file is not None: self._qemu_log_file.close() self._qemu_log_file = None @@ -296,6 +298,17 @@ def _post_shutdown(self): while len(self._remove_files) > 0: self._remove_if_exists(self._remove_files.pop()) + exitcode = self.exitcode() + if exitcode is not None and exitcode < 0: + msg = 'qemu received signal %i; command: "%s"' + if self._qemu_full_args: + command = ' '.join(self._qemu_full_args) + else: + command = '' + LOG.warning(msg, -int(exitcode), command) + + self._launched = False + def launch(self): """ Launch the VM and make sure we cleanup and expose the @@ -344,12 +357,53 @@ def wait(self): self._popen.wait() if self._qmp: self._qmp.close() - self._load_io_log() self._post_shutdown() - def shutdown(self, has_quit=False, hard=False): + def _hard_shutdown(self) -> None: """ - Terminate the VM and clean up + Kill the VM if it is running. + """ + if not self.is_running(): + return + + self._popen.kill() + self._popen.wait(timeout=60) + + def _soft_shutdown(self, has_quit: bool = False, timeout: int = 3) -> None: + """ + Attempt to shutdown the VM gracefully if it is running. + + :param has_quit: When True, don't attempt to issue 'quit' QMP command + :param timeout: Timeout for graceful shutdown. Default 3 seconds. + """ + if not self.is_running(): + return + + if self._qmp is not None: + if not has_quit: + self._qmp.cmd('quit') + self._qmp.close() + + self._popen.wait(timeout=timeout) + + def _do_shutdown(self, has_quit: bool = False, timeout: int = 3) -> None: + """ + Attempt to shutdown the VM gracefully; fallback to a hard shutdown. + + :param has_quit: When True, don't attempt to issue 'quit' QMP command + :param timeout: Timeout for graceful shutdown. Default 3 seconds. + """ + try: + self._soft_shutdown(has_quit, timeout) + except subprocess.TimeoutExpired: + self._hard_shutdown() + except: + self._hard_shutdown() + raise + + def shutdown(self, has_quit: bool = False, hard: bool = False) -> None: + """ + Terminate the VM (gracefully if possible) and perform cleanup. """ # If we keep the console socket open, we may deadlock waiting # for QEMU to exit, while QEMU is waiting for the socket to @@ -358,35 +412,18 @@ def shutdown(self, has_quit=False, hard=False): self._console_socket.close() self._console_socket = None - if self.is_running(): + try: if hard: - self._popen.kill() - elif self._qmp: - try: - if not has_quit: - self._qmp.cmd('quit') - self._qmp.close() - self._popen.wait(timeout=3) - except: - self._popen.kill() - self._popen.wait() - - self._load_io_log() - self._post_shutdown() - - exitcode = self.exitcode() - if exitcode is not None and exitcode < 0 and \ - not (exitcode == -9 and hard): - msg = 'qemu received signal %i: %s' - if self._qemu_full_args: - command = ' '.join(self._qemu_full_args) + self._hard_shutdown() else: - command = '' - LOG.warning(msg, -int(exitcode), command) - - self._launched = False + self._do_shutdown(has_quit) + finally: + self._post_shutdown() def kill(self): + """ + Terminate the VM forcefully and perform cleanup. + """ self.shutdown(hard=True) def set_qmp_monitor(self, enabled=True): -- 2.21.3