2403C++,C++20协程通道

原文
通道是一个可用来连接协程,实现不同协程间通信的并发安全队列.

@Test
fun `test know channel`() = runBlocking<Unit> {
    val channel = Channel<Int>()
    //生产者
    val producer = GlobalScope.launch {
        var i = 0
        while (true) {
            delay(1000)
            channel.send(++i)
            println("send $i")
        }
    }
    //消费者
    val consumer = GlobalScope.launch {
        while (true) {
            val element = channel.receive()
            println("receive $element")
        }
    }
    joinAll(producer, consumer)
}
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21

该示例很简单,生产者协程和消费者协程通过通道通信.

C++20协程有通道吗?与go和kotlin那样的通道.
答案是:有,就在yalantinglibs的coro_io里面.

来看看C++20协程通道的用法:

  auto executor = coro_io::get_global_block_executor()->get_asio_executor();
  asio::experimental::channel<void(std::error_code, int)> channel(executor, 1000);
  co_await coro_io::async_send(ch, 42);
  auto [ec, val] = co_await coro_io::async_receive<int>(channel);
  assert(val == 42);
1
2
3
4
5

创建了个容量为1000的通道,后续就可通过该通道实现协程间通信了.
这就是C++20协程通道,用法和go,kotlin的通道类似.