def unregisterHandler(self, fh):
try:<EOL><INDENT>self.fds.remove(fh)<EOL><DEDENT>except KeyError:<EOL><INDENT>pass<EOL><DEDENT>self.lock.acquire()<EOL>try:<EOL><INDENT>self.data.rollover() <EOL><DEDENT>finally:<EOL><INDENT>self.lock.release()<EOL><DEDENT>if self.closing and not self.fds:<EOL><INDENT>self.data.close()<EOL><DEDENT>
Unregister a file descriptor. Clean data, if such operation has been scheduled.

Parameters
----------
fh : int
    File descriptor.