On Tue, Sep 5, 2017 at 5:18 AM, Fam Zheng <f...@redhat.com> wrote: > On Fri, 09/01 13:28, Amador Pahim wrote: >> To launch a VM, we need to create basically two files: the monitor >> socket (if it's a UNIX socket) and the qemu log file. >> >> For the qemu log file, we currently just open the path, which will >> create the file if it does not exist or overwrite the file if it does >> exist. >> >> For the monitor socket, if it already exists, we are currently removing >> it, even if it's not created by us. >> >> This patch moves to pre_launch() the responsibility to make sure we only >> create files that are not pre-existent and to populate a list of >> controlled files. This list will then be used as the reference of >> files to remove during the cleanup (post_shutdown()). >> >> Signed-off-by: Amador Pahim <apa...@redhat.com> >> --- >> scripts/qemu.py | 30 +++++++++++++++++++++++------- >> 1 file changed, 23 insertions(+), 7 deletions(-) >> >> diff --git a/scripts/qemu.py b/scripts/qemu.py >> index 3ebe5ee0a4..c26e1412f9 100644 >> --- a/scripts/qemu.py >> +++ b/scripts/qemu.py >> @@ -41,6 +41,7 @@ class QEMUMachine(object): >> monitor_address = os.path.join(test_dir, name + "-monitor.sock") >> self._monitor_address = monitor_address >> self._qemu_log_path = os.path.join(test_dir, name + ".log") >> + self._qemu_log_fd = None >> self._popen = None >> self._binary = binary >> self._args = list(args) # Force copy args in case we modify them >> @@ -50,6 +51,7 @@ class QEMUMachine(object): >> self._socket_scm_helper = socket_scm_helper >> self._debug = debug >> self._qemu_full_args = None >> + self._created_files = [] >> >> # This can be used to add an unused monitor instance. >> def add_monitor_telnet(self, ip, port): >> @@ -128,30 +130,44 @@ class QEMUMachine(object): >> '-display', 'none', '-vga', 'none'] >> >> def _pre_launch(self): >> - self._qmp = qmp.qmp.QEMUMonitorProtocol(self._monitor_address, >> server=True, >> - debug=self._debug) >> + try: >> + self._qmp = qmp.qmp.QEMUMonitorProtocol(self._monitor_address, >> + server=True, >> + debug=self._debug) >> + except: >> + raise > > What's the point of "except: raise"? It seems useless.
The point is to execute the block in the else only when no exception happens. When some exception happens, I want to raise it without executing the else block. > >> + else: >> + if not isinstance(self._monitor_address, tuple): >> + self._created_files.append(self._monitor_address) >> + >> + try: >> + flags = os.O_CREAT | os.O_EXCL | os.O_WRONLY >> + os.open(self._qemu_log_path, flags) > > Why change to os.open() instead of open()? I want to create the file only if it does not exist. The open() flag 'x' is available only in python 3.3. For python <3.3, we need the os.open() to have that feature. > >> + except: >> + raise >> + else: >> + self._created_files.append(self._qemu_log_path) >> + self._qemu_log_fd = open(self._qemu_log_path, 'wb') >> >> def _post_launch(self): >> self._qmp.accept() >> >> def _post_shutdown(self): >> - if not isinstance(self._monitor_address, tuple): >> - self._remove_if_exists(self._monitor_address) >> - self._remove_if_exists(self._qemu_log_path) >> + while self._created_files: >> + self._remove_if_exists(self._created_files.pop()) >> >> def launch(self): >> '''Launch the VM and establish a QMP connection''' >> self._iolog = None >> self._qemu_full_args = None >> devnull = open(os.path.devnull, 'rb') >> - qemulog = open(self._qemu_log_path, 'wb') >> try: >> self._pre_launch() >> self._qemu_full_args = (self._wrapper + [self._binary] + >> self._base_args() + self._args) >> self._popen = subprocess.Popen(self._qemu_full_args, >> stdin=devnull, >> - stdout=qemulog, >> + stdout=self._qemu_log_fd, >> stderr=subprocess.STDOUT, >> shell=False) >> self._post_launch() >> -- >> 2.13.5 >> > > Fam