cron: use prctl to set process name & title (#2524)

wcs/qommon/cron.py

@@ -18,9 +18,9 @@ import os
 import signal
 import time
 try:
-    import dl
+    import prctl
 except ImportError:
-    dl = None
+    prctl = None
 import sys
 
 parent_killed = False
@@ -88,17 +88,10 @@ def spawn_cron(create_publisher):
     cron_pid = os.fork()
     if cron_pid == 0:
         pub = create_publisher()
-        # set process name, this only works on Linux, 15 == PR_SET_NAME
-        if dl:
-            try:
-                libc = dl.open('/lib/libc.so.6')
-            except dl.error:
-                pass
-            else:
-                try:
-                    libc.call('prctl', 15, os.path.basename(sys.argv[0]) + ' [cron]\0', 0, 0, 0)
-                except ValueError: # missing symbol
-                    pass
+        # set process name and title (this only works on Linux)
+        if prctl:
+            prctl.set_name(os.path.basename(sys.argv[0]) + ' [cron]')
+            prctl.set_proctitle(os.path.basename(sys.argv[0]) + ' [cron]')
         signal.signal(signal.SIGTERM, stop_cron_process)
         cron(pub)
         sys.exit(0)