如何在JavaScript中实现锁 [英] How to implement a lock in JavaScript

问题描述

如何在C＃中实现与C＃中的 lock 相当的东西？

How could something equivalent to lock in C# be implemented in JavaScript?

所以，要解释一下'想一个简单的用例是：

So, to explain what I'm thinking a simple use case is:

用户点击按钮 B 。 B 引发onclick事件。如果 B 在事件状态中，事件将等待 B 在传播前位于 ready-state 中。如果 B 在 ready-state 中， B 被锁定并设置为 event-state ，则事件将传播。当事件的传播完成时， B 设置为 ready-state 。

User clicks button B. B raises an onclick event. If B is in event-state the event waits for B to be in ready-state before propagating. If B is in ready-state, B is locked and is set to event-state, then the event propagates. When the event's propagation is complete, B is set to ready-state.

只要从按钮中添加和删除类 ready-state ，我可以看到接近这一点的事情可以完成。但是，问题是用户可以比可以设置变量的速度更快地单击一个按钮两次，因此在某些情况下，此尝试将失败。

I could see how something close to this could be done, simply by adding and removing the class ready-state from the button. However, the problem is that a user can click a button twice in a row faster than the variable can be set, so this attempt at a lock will fail in some circumstances.

有没有人知道如何实现一个不会在JavaScript中失败的锁？

Does anyone know how to implement a lock that will not fail in JavaScript?

推荐答案

在JS中，锁是一个有问题的想法，意图是无线程的，不需要并发保护。你正在寻找结合延迟执行的电话。我关注的模式是使用回调。这样做：

Lock is a questionable idea in JS which is intended to be threadless and not needing concurrency protection. You're looking to combine calls on deferred execution. The pattern I follow for this is the use of callbacks. Something like this:

var functionLock = false;
var functionCallbacks = [];
var lockingFunction = function (callback) {
    if (functionLock) {
        functionCallbacks.push(callback);
    } else {
        $.longRunning(function(response) {
             while(functionCallbacks.length){
                 var thisCallback = functionCallbacks.pop();
                 thisCallback(response);
             }
        });
    }
}

您还可以使用DOM事件侦听器或pubsub解决方案。

You can also implement this using DOM event listeners or a pubsub solution.

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