add process title setting to activities

* they now will show up as Activity Name <id> in the process list
     truncated to 15 characters though

sugar/activity/activity.py

@@ -29,6 +29,7 @@ import tempfile
 import gtk, gobject
 import dbus
 
+from sugar import util        
 from sugar.presence import presenceservice
 from sugar.activity.activityservice import ActivityService
 from sugar.graphics import units
@@ -199,6 +200,13 @@ class Activity(Window, gtk.Container):
         """
         Window.__init__(self)
 
+        # process titles will only show 15 characters
+        # but they get truncated anyway so if more characters
+        # are supported in the future we will get a better view
+        # of the processes
+        proc_title = "%s <%s>" % (get_bundle_name(), handle.activity_id)
+        util.set_proc_title(proc_title)
+
         self.connect('realize', self._realize_cb)
         self.connect('delete-event', self._delete_event_cb)
 
@@ -397,3 +405,4 @@ def get_bundle_path():
     """Return the bundle path for the current process' bundle
     """
     return os.environ['SUGAR_BUNDLE_PATH']
+

sugar/util.py

@@ -103,3 +103,25 @@ def write_service(name, bin, path):
     fileobject = open(dest_filename, 'w')
     service_cp.write(fileobject)
     fileobject.close()
+
+def set_proc_title(title):
+    """Sets the process title so ps and top show more
+       descriptive names.  This does not modify argv[0]
+       and only the first 15 characters will be shown.
+
+       title -- the title you wish to change the process
+                title to 
+
+       Returns True on success.  We don't raise exceptions
+       because if something goes wrong here it is not a big
+       deal as this is intended as a nice thing to have for
+       debugging
+    """
+    try:
+        import ctypes
+        libc = ctypes.CDLL('libc.so.6')
+        libc.prctl(15, str(title), 0, 0, 0)
+
+        return True
+    except:
+        return False