浏览器使用postMessage实现零延时定时器

Posted 2022-03-12 刘翾

原文地址: https://dbaron.org/log/20100309-faster-timeouts
作者: David Baron

浏览器零延时定时器

    (function() 
        var timeouts = [];
        var messageName = "zero-timeout-message";

        // 类似setTimeout, 但是仅仅接受一个函数argument, 没有延迟时间参数(永远是0)
        function setZeroTimeout(fn) 
            timeouts.push(fn);
            window.postMessage(messageName, "*");
        

        function handleMessage(event) 
            if (event.source == window && event.data == messageName) 
                event.stopPropagation();
                if (timeouts.length > 0) 
                    var fn = timeouts.shift();
                    fn();
                
            
        

        window.addEventListener("message", handleMessage, true);

        // Add the one thing we want added to the window object.
        window.setZeroTimeout = setZeroTimeout;
    )();