[Qemu-devel] [PATCH v12 4/6] qemu.py: use poll() instead of 'returncode'

[Amador Pahim]

The 'returncode' Popen attribute is not guaranteed to be updated. It
actually depends on a call to either poll(), wait() or communicate().

On the other hand, poll() will: "Check if child process has terminated.
Set and return returncode attribute."

Let's use the poll() to check whether the process is running and to get
the updated process exit code, when the process is finished.

Reviewed-by: Fam Zheng <address@hidden>
eviewed-by: Eduardo Habkost <address@hidden>
Signed-off-by: Amador Pahim <address@hidden>
---
 scripts/qemu.py | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/scripts/qemu.py b/scripts/qemu.py
index d6661870ab..874ac2e424 100644
--- a/scripts/qemu.py
+++ b/scripts/qemu.py
@@ -151,12 +151,12 @@ class QEMUMachine(object):
             raise
 
     def is_running(self):
-        return self._popen is not None and self._popen.returncode is None
+        return self._popen is not None 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():
-- 
2.14.3