Waiting for pid file to be created before we proceed

tiny_utils.py

@@ -6,6 +6,7 @@
 ## This is the module that recomputes IP and UDP packet checksums
 
 import os, pwd, grp, sys
+import errno
 import signal
 import atexit
 
@@ -45,7 +46,13 @@ def do_daemonize(pid_file):
  write_pid_file2(pid_file, pid)
  sys.exit(0); # exit from second parent
  # wait for the initial process to finish so that pid file is written
- os.waitpid(pid_init, 0)
+ try:
+ os.waitpid(pid_init, 0)
+ except OSError as err:
+ # ECHILD means that initial process has ended
+ if err.errno != errno.ECHILD:
+ raise
+ # pig_file has to be deleted
  atexit.register(os.remove, pid_file)
 
 def write_pid_file2(fname, pid):