[Qemu-devel] [PATCH v8 10/13] qemu.py: use poll() instead of 'returncode'

Amador Pahim posted 13 patches 8 years, 2 months ago
There is a newer version of this series
[Qemu-devel] [PATCH v8 10/13] qemu.py: use poll() instead of 'returncode'
Posted by Amador Pahim 8 years, 2 months ago
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.

Signed-off-by: Amador Pahim <apahim@redhat.com>
---
 scripts/qemu.py | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/scripts/qemu.py b/scripts/qemu.py
index ede734328b..87a2212b77 100644
--- a/scripts/qemu.py
+++ b/scripts/qemu.py
@@ -102,12 +102,12 @@ 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():
-- 
2.13.5


Re: [Qemu-devel] [PATCH v8 10/13] qemu.py: use poll() instead of 'returncode'
Posted by Fam Zheng 8 years, 2 months ago
On Fri, 09/01 13:28, Amador Pahim wrote:
> 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.
> 
> Signed-off-by: Amador Pahim <apahim@redhat.com>

Reviewed-by: Fam Zheng <famz@redhat.com>