[Qemu-devel] [PATCH v8 08/13] qemu.py: refactor launch()

[Amador Pahim <apahim@redhat.com>]

This is just an refactor to separate the exception handler from the
actual launch procedure, improving the readability and making future
maintenances in this piece of code easier.

Signed-off-by: Amador Pahim <apahim@redhat.com>
---
 scripts/qemu.py | 29 ++++++++++++++++++-----------
 1 file changed, 18 insertions(+), 11 deletions(-)

diff --git a/scripts/qemu.py b/scripts/qemu.py
index 1b77fec48b..06f07bfaa2 100644
--- a/scripts/qemu.py
+++ b/scripts/qemu.py
@@ -160,20 +160,14 @@ class QEMUMachine(object):
             self._remove_if_exists(self._created_files.pop())
 
     def launch(self):
-        '''Launch the VM and establish a QMP connection'''
+        '''
+        Try to launch the VM and make sure we cleanup and expose the
+        command line/output in case of exception.
+        '''
         self._iolog = None
         self._qemu_full_args = None
-        devnull = open(os.path.devnull, 'rb')
         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=self._qemu_log_fd,
-                                           stderr=subprocess.STDOUT,
-                                           shell=False)
-            self._post_launch()
+            self._launch()
         except:
             if self.is_running():
                 self._popen.kill()
@@ -188,6 +182,19 @@ class QEMUMachine(object):
                 LOG.debug('Output: %r', self._iolog)
             raise
 
+    def _launch(self):
+        '''Launch the VM and establish a QMP connection'''
+        devnull = open(os.path.devnull, 'rb')
+        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=self._qemu_log_fd,
+                                       stderr=subprocess.STDOUT,
+                                       shell=False)
+        self._post_launch()
+
     def shutdown(self):
         '''Terminate the VM and clean up'''
         if self.is_running():
-- 
2.13.5