swoole协程阻塞问题

Question

swoole中协程被阻塞

demo.php:

Co::set([
    'trace_flags' => SWOOLE_TRACE_CLOSE
]);


$chan = new \Swoole\Coroutine\Channel();
function task1(\Swoole\Coroutine\Channel $chan) {
    Co::sleep(0.005);
    $chan->push([__METHOD__=>__LINE__]);
}
function task2(\Swoole\Coroutine\Channel $chan) {
    Co::sleep(0.005);
    $chan->push([__METHOD__=>__LINE__]);
}
go("task1", $chan);
go("task2", $chan);
go(function () use ($chan){
    while(!$chan->isEmpty()) {
        var_dump($chan->pop());
    }
});

现象：执行php demo.php长时间阻塞

Answer 1

因为 $chan->isEmpty() === true
while 里面的循环不会被执行
阻塞的原因是因为 $chan 容量为默认为1
第二个push阻塞了

Answer 2

只跑一个协程，为什么立即就退出了？@探索者

$chan = new \Swoole\Coroutine\Channel();
function task1(\Swoole\Coroutine\Channel $chan) {
    Co::sleep(0.005);
    $chan->push([__METHOD__=>__LINE__]);
}
go("task1", $chan);
go(function () use ($chan){
    // isEmpty===true,跳过执行
    while(!$chan->isEmpty()) {
        var_dump($chan->pop());
    }
});