[tor-commits] [stem/master] Uncaught exception when name_by_pid() fails to call ps

[atagar at torproject.org]

commit efd1c86073ad04ec3c6d79c97dd3db5d3255fdf6
Author: Damian Johnson <atagar at torproject.org>
Date:   Sun Sep 7 21:10:35 2014 -0700

    Uncaught exception when name_by_pid() fails to call ps
    
    Our name_by_pid() function is documented as returning None if it can't deterine
    the process name, but we accidently exposed a possible OSException via our ps
    call. Ran into this during arm development...
    
      File "/home/atagar/Desktop/arm/arm/util/tracker.py", line 398, in _tor_status_listener
        tor_cmd = system.name_by_pid(tor_pid) if tor_pid else None
      File "/home/atagar/Desktop/arm/stem/util/system.py", line 272, in name_by_pid
        results = call(GET_NAME_BY_PID_PS % pid)
      File "/home/atagar/Desktop/arm/stem/util/system.py", line 921, in call
        raise exc
      OSError: ps -p 30834 -o comm returned exit status 1
---
 stem/util/system.py |    5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/stem/util/system.py b/stem/util/system.py
index adfc802..bcd6c0d 100644
--- a/stem/util/system.py
+++ b/stem/util/system.py
@@ -269,7 +269,10 @@ def name_by_pid(pid):
   #   vim
 
   if not process_name:
-    results = call(GET_NAME_BY_PID_PS % pid)
+    try:
+      results = call(GET_NAME_BY_PID_PS % pid)
+    except OSError:
+      pass
 
     if results and len(results) == 2 and results[0] == 'COMMAND':
       process_name = results[1].strip()