1 def synchronized(lock):

     2     """ Synchronization decorator. """

     3     

     4     def wrap(f):

     5         def newFunction(*args, **kw):

     6             lock.acquire()

     7             try:

     8                 return f(*args, **kw)

     9             finally:

    10                 lock.release()

    11         return newFunction

    12     return wrap

    13 

    14 import sys, os

    15 

    16 def daemonize(stdin='/dev/null', stdout='/dev/null', stderr='/dev/null'):

    17 

    18     # Perform first fork.

    19     try:

    20         pid = os.fork()

    21         if pid > 0:

    22             sys.exit(0) # Exit first parent.

    23     except OSError, e:

    24         sys.stderr.write("fork #1 failed: (%d) %s\n" % (e.errno, e.strerror))

    25         sys.exit(1)

    26 

    27     # Decouple from parent environment.

    28     os.chdir("/")

    29     os.umask(0)

    30     os.setsid()

    31 

    32     # Perform second fork.

    33     try:

    34         pid = os.fork()

    35         if pid > 0:

    36             sys.exit(0) # Exit second parent.

    37     except OSError, e:

    38         sys.stderr.write("fork #2 failed: (%d) %s\n" % (e.errno, e.strerror))

    39         sys.exit(1)

    40 

    41     # The process is now daemonized, redirect standard file descriptors.

    42     for f in sys.stdout, sys.stderr: f.flush()

    43     si = file(stdin, 'r')

    44     so = file(stdout, 'a+')

    45     se = file(stderr, 'a+', 0)

    46     os.dup2(si.fileno(), sys.stdin.fileno())

    47     os.dup2(so.fileno(), sys.stdout.fileno())

    48     os.dup2(se.fileno(), sys.stderr.fileno())