How to use the gunicorn.util.close_on_exec function in gunicorn

def init_signals(self):
        """\
        Initialize master signal handling. Most of the signals
        are queued. Child signals only wake up the master.
        """
        if self.PIPE:
            map(os.close, self.PIPE)
        self.PIPE = pair = os.pipe()
        map(util.set_non_blocking, pair)
        map(util.close_on_exec, pair)
        self.log.close_on_exec()
        map(lambda s: signal.signal(s, self.signal), self.SIGNALS)
        signal.signal(signal.SIGCHLD, self.handle_chld)

util.set_owner_process(self.cfg.uid, self.cfg.gid,
                               initgroups=self.cfg.initgroups)

        # Reseed the random number generator
        util.seed()

        # For waking ourselves up
        self.PIPE = os.pipe()
        for p in self.PIPE:
            util.set_non_blocking(p)
            util.close_on_exec(p)

        # Prevent fd inheritance
        for s in self.sockets:
            util.close_on_exec(s)
        util.close_on_exec(self.tmp.fileno())

        self.wait_fds = self.sockets + [self.PIPE[0]]

        self.log.close_on_exec()

        self.init_signals()

        # start the reloader
        if self.cfg.reload:
            def changed(fname):
                self.log.info("Worker reloading: %s modified", fname)
                self.alive = False
                self.cfg.worker_int(self)
                time.sleep(0.1)
                sys.exit(0)

util.set_owner_process(self.cfg.uid, self.cfg.gid,
                               initgroups=self.cfg.initgroups)

        # Reseed the random number generator
        util.seed()

        # For waking ourselves up
        self.PIPE = os.pipe()
        for p in self.PIPE:
            util.set_non_blocking(p)
            util.close_on_exec(p)

        # Prevent fd inheritance
        for s in self.sockets:
            util.close_on_exec(s)
        util.close_on_exec(self.tmp.fileno())

        self.wait_fds = self.sockets + [self.PIPE[0]]

        self.log.close_on_exec()

        self.init_signals()

        self.load_wsgi()

        # start the reloader
        if self.cfg.reload:
            def changed(fname):
                self.log.info("Worker reloading: %s modified", fname)
                self.alive = False
                os.write(self.PIPE[1], b"1")
                self.cfg.worker_int(self)

def accept(self, listener):
        client, addr = listener.accept()
        client.setblocking(1)
        util.close_on_exec(client)
        self.handle(listener, client, addr)

def init_signals(self):
        """\
        Initialize master signal handling. Most of the signals
        are queued. Child signals only wake up the master.
        """
        # close old PIPE
        for p in self.PIPE:
            os.close(p)

        # initialize the pipe
        self.PIPE = pair = os.pipe()
        for p in pair:
            util.set_non_blocking(p)
            util.close_on_exec(p)

        self.log.close_on_exec()

        # initialize all signals
        for s in self.SIGNALS:
            signal.signal(s, self.signal)
        signal.signal(signal.SIGCHLD, self.handle_chld)

def init_process(self):
        util.set_owner_process(self.conf.uid, self.conf.gid)
        
        # init pipe
        self.PIPE = os.pipe()
        map(util.set_non_blocking, self.PIPE)
        map(util.close_on_exec, self.PIPE)
        
        # prevent inherientence
        util.close_on_exec(self.socket)
        util.close_on_exec(self.fd)
        self.init_signals()

def init_signals(self):
        """\
        Initialize master signal handling. Most of the signals
        are queued. Child signals only wake up the master.
        """
        # close old PIPE
        for p in self.PIPE:
            os.close(p)

        # initialize the pipe
        self.PIPE = pair = os.pipe()
        for p in pair:
            util.set_non_blocking(p)
            util.close_on_exec(p)

        self.log.close_on_exec()

        # initialize all signals
        for s in self.SIGNALS:
            signal.signal(s, self.signal)
        signal.signal(signal.SIGCHLD, self.handle_chld)

util.set_owner_process(self.cfg.uid, self.cfg.gid,
                               initgroups=self.cfg.initgroups)

        # Reseed the random number generator
        util.seed()

        # For waking ourselves up
        self.PIPE = os.pipe()
        for p in self.PIPE:
            util.set_non_blocking(p)
            util.close_on_exec(p)

        # Prevent fd inheritance
        for s in self.sockets:
            util.close_on_exec(s)
        util.close_on_exec(self.tmp.fileno())

        self.wait_fds = self.sockets + [self.PIPE[0]]

        self.log.close_on_exec()

        self.init_signals()

        self.load_wsgi()

        # start the reloader
        if self.cfg.reload:
            def changed(fname):
                self.log.info("Worker reloading: %s modified", fname)
                self.alive = False
                os.write(self.PIPE[1], b"1")

def accept(self, listener):
        client, addr = listener.accept()
        client.setblocking(1)
        util.close_on_exec(client)
        self.handle(listener, client, addr)

# set environment' variables
        if self.cfg.env:
            for k, v in self.cfg.env.items():
                os.environ[k] = v

        util.set_owner_process(self.cfg.uid, self.cfg.gid,
                               initgroups=self.cfg.initgroups)

        # Reseed the random number generator
        util.seed()

        # For waking ourselves up
        self.PIPE = os.pipe()
        for p in self.PIPE:
            util.set_non_blocking(p)
            util.close_on_exec(p)

        # Prevent fd inheritance
        for s in self.sockets:
            util.close_on_exec(s)
        util.close_on_exec(self.tmp.fileno())

        self.wait_fds = self.sockets + [self.PIPE[0]]

        self.log.close_on_exec()

        self.init_signals()

        # start the reloader
        if self.cfg.reload:
            def changed(fname):
                self.log.info("Worker reloading: %s modified", fname)