import pwd
import tempfile
import threading
+import fcntl
import logger
os.chdir('/')
os.umask(0)
devnull = os.open(os.devnull, os.O_RDWR)
- for fd in range(3): os.dup2(devnull, fd)
+ os.dup2(devnull, 0)
+ crashlog = os.open('/root/nm.stderr', os.O_RDWR | os.O_APPEND | os.O_CREAT, 0644)
+ os.dup2(crashlog, 1)
+ os.dup2(crashlog, 2)
def fork_as(su, function, *args):
"""fork(), cd / to avoid keeping unused directories open, close all nonstandard file descriptors (to avoid capturing open sockets), fork() again (to avoid zombies) and call <function> with arguments <args> in the grandchild process. If <su> is not None, set our group and user ids appropriately in the child process."""
try: do_write(f)
finally: f.close()
return temporary_filename
+
+
+class NMLock:
+ def __init__(self, file):
+ self.fd = os.open(file, os.O_RDWR|os.O_CREAT, 0600)
+ flags = fcntl.fcntl(self.fd, fcntl.F_GETFD)
+ flags |= fcntl.FD_CLOEXEC
+ fcntl.fcntl(self.fd, fcntl.F_SETFD, flags)
+ def __del__(self):
+ os.close(self.fd)
+ def acquire(self):
+ fcntl.lockf(self.fd, fcntl.LOCK_EX)
+ def release(self):
+ fcntl.lockf(self.fd, fcntl.LOCK_UN)