is_running(): - Use Popen.poll() instead of Popen.returncode to check whether the VM is running or not.
exitcode(): - Use Popen.poll() instead of Popen.returncode to return an updated exit code. _load_io_log(): - Add a try/except to prevent raising exception when qemu io file does not exist. launch(): - If VM is already running, do nothing. - If vm is not running but was not cleaned up, call shutdown() before launching again. - Offload the core of this method to _launch(). - Load the args and try to call _launch(). - Make sure we cleanup on exception. - On exception, print an error message with the qemu command line and output. _launch(): - Execute _pre_launch(), subprocess.Popen() and self._post_launch(). - No try/except here. Any exceptions will be handled by the caller. shutdown(): - Make sure self._popen is not None before calling self._popen.wait(). - Cleanup the message on negative exit codes. - Always execute self._load_io_log() and self._post_shutdown(). Signed-off-by: Amador Pahim <apa...@redhat.com> --- scripts/qemu.py | 69 ++++++++++++++++++++++++++++++++++++++------------------- 1 file changed, 46 insertions(+), 23 deletions(-) diff --git a/scripts/qemu.py b/scripts/qemu.py index fb83e3f998..76d4880f36 100644 --- a/scripts/qemu.py +++ b/scripts/qemu.py @@ -39,6 +39,7 @@ class QEMUMachine(object): self._iolog = None self._socket_scm_helper = socket_scm_helper self._debug = debug + self._shutdown_pending = False # This can be used to add an unused monitor instance. def add_monitor_telnet(self, ip, port): @@ -86,12 +87,12 @@ class QEMUMachine(object): raise def is_running(self): - return self._popen and (self._popen.returncode is None) + return self._popen and (self._popen.poll() is None) def exitcode(self): if self._popen is None: return None - return self._popen.returncode + return self._popen.poll() def get_pid(self): if not self.is_running(): @@ -99,8 +100,11 @@ class QEMUMachine(object): return self._popen.pid def _load_io_log(self): - with open(self._qemu_log_path, "r") as fh: - self._iolog = fh.read() + try: + with open(self._qemu_log_path, "r") as fh: + self._iolog = fh.read() + except IOError: + pass def _base_args(self): if isinstance(self._monitor_address, tuple): @@ -126,25 +130,43 @@ class QEMUMachine(object): self._remove_if_exists(self._qemu_log_path) def launch(self): - '''Launch the VM and establish a QMP connection''' - devnull = open('/dev/null', 'rb') - qemulog = open(self._qemu_log_path, 'wb') + ''' + Try to launch the VM and make sure we cleanup and expose the + command line/output in case of exception. + ''' + if self.is_running(): + return + + if self._shutdown_pending: + sys.stderr.write('shutdown() was not called after previous ' + 'launch(). Calling now.\n') + self.shutdown() + try: - self._pre_launch() - args = self._wrapper + [self._binary] + self._base_args() + self._args - self._popen = subprocess.Popen(args, stdin=devnull, stdout=qemulog, - stderr=subprocess.STDOUT, shell=False) - self._post_launch() + args = None + args = self._wrapper + [self._binary] + self._base_args() + self.args + self._launch(args) + self._shutdown_pending = True except: - if self.is_running(): - self._popen.kill() - self._popen.wait() - self._load_io_log() - self._post_shutdown() + self.shutdown() + sys.stderr.write('Error launching VM.\n%s%s' % + ('Command:\n%s\n' % + ' '.join(args) if args else '', + 'Output:\n%s\n' % + ''.join(self._iolog) if self._iolog else '')) raise + def _launch(self, args): + '''Launch the VM and establish a QMP connection.''' + devnull = open('/dev/null', 'rb') + qemulog = open(self._qemu_log_path, 'wb') + self._pre_launch() + self._popen = subprocess.Popen(args, stdin=devnull, stdout=qemulog, + stderr=subprocess.STDOUT, shell=False) + self._post_launch() + def shutdown(self): - '''Terminate the VM and clean up''' + '''Terminate the VM and clean up.''' if self.is_running(): try: self._qmp.cmd('quit') @@ -152,11 +174,12 @@ class QEMUMachine(object): except: self._popen.kill() - exitcode = self._popen.wait() - if exitcode < 0: - sys.stderr.write('qemu received signal %i: %s\n' % (-exitcode, ' '.join(self._args))) - self._load_io_log() - self._post_shutdown() + if self._popen and self._popen.wait() < 0: + sys.stderr.write('qemu received signal %i\n' % -self.exitcode()) + + self._load_io_log() + self._post_shutdown() + self._shutdown_pending = False underscore_to_dash = string.maketrans('_', '-') def qmp(self, cmd, conv_keys=True, **args): -- 2.13.3