# -*- coding: utf-8 -*-
# MegEngine is Licensed under the Apache License, Version 2.0 (the "License")
#
# Copyright (c) 2014-2020 Megvii Inc. All rights reserved.
#
# Unless required by applicable law or agreed to in writing,
# software distributed under the License is distributed on an
# "AS IS" BASIS, WITHOUT ARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
import functools
import socket
import threading
from typing import List


class Future:
    def __init__(self, ack=True):
        self.ready = threading.Event()
        self.ack = threading.Event() if ack else None

    def set(self, value):
        self.value = value
        self.ready.set()
        if self.ack:
            self.ack.wait()

    def get(self):
        self.ready.wait()
        if self.ack:
            self.ack.set()
        return self.value


def get_free_ports(num: int) -> List[int]:
    """Get one or more free ports.
    """
    socks, ports = [], []
    for i in range(num):
        sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
        sock.bind(("", 0))
        socks.append(sock)
        ports.append(sock.getsockname()[1])
    for sock in socks:
        sock.close()
    return ports