Godeps/_workspace/src/gopkg.in/mgo.v2/server.go
func (server *mongoServer) Close() {
	server.Lock()
	server.closed = true
	liveSockets := server.liveSockets
	unusedSockets := server.unusedSockets
	server.liveSockets = nil
	server.unusedSockets = nil
	server.Unlock()
	logf("Connections to %s closing (%d live sockets).", server.Addr, len(liveSockets))
	for i, s := range liveSockets {
		s.Close()
		liveSockets[i] = nil
	}
	for i := range unusedSockets {
		unusedSockets[i] = nil
	}
}
func (server *mongoServer) Close() {
	server.Lock()
	server.closed = true
	liveSockets := server.liveSockets
	unusedSockets := server.unusedSockets
	server.liveSockets = nil
	server.unusedSockets = nil
	server.Unlock()
	logf("Connections to %s closing (%d live sockets).", server.Addr, len(liveSockets))
	for i, s := range liveSockets {
		s.Close()
		liveSockets[i] = nil
	}
	for i := range unusedSockets {
		unusedSockets[i] = nil
	}
}
// Close forces closing all sockets that are alive, whether
// they're currently in use or not.