JavaScript是单线程？如果没有，我如何才能同步访问共享数据？ [英] Is JavaScript single threaded? If not, how do I get synchronized access to shared data?

问题描述

我有 DIV网页 s的一个鼠标悬停处理程序，旨在显示弹出信息泡沫。我不想在同一时间多个信息泡可见。但是，当用户在两个项目快速移动鼠标时，我有时会收到两个气泡。这不应该发生，因为code为显示弹出取消previous弹出。

I have a web page with DIVs with a mouseover handler that is intended to show a pop-up information bubble. I don't want more than one info bubble to be visible at a time. But when the user moves the mouse rapidly over two items, I sometimes get two bubbles. This should not happen, because the code for showing a pop-up cancels the previous pop-up.

如果这是一个多线程系统那么问题是显而易见的：有两个线程试图表明一个弹出窗口，他们都取消现有的弹出窗口，然后弹出自己的弹出窗口。但我以为JavaScript是始终运行单线程的，这将prevent这一点。我错了吗？在事件处理异步运行，在这种情况下，我需要共享数据同步的访问，或者我应该改为寻找库code错误取消弹出窗口？

If this were a multi-threaded system then the problem would be obvious: there are two threads trying to show a pop-up, and they both cancel existing pop-ups then pop up their own pop-ups. But I assumed JavaScript is always run single-threaded, which would prevent this. Am I wrong? Are event handlers running asynchronously, in which case I need synchronized access to shared data, or should I instead be looking for bugs in the library code for cancelling pop-ups?

编辑补充：

• 在问题库是 SIMILE时间轴和Ajax库;


• 事件处理程序调用 SimileAjax.DOM.cancelEvent（domEvt），我假设基于名称取消事件的冒泡;


• 只是为了勾起回忆更为复杂，有什么我实际上做的是开始一个超时，如果不是由 moustout 取消显示弹出，这正打算prevent弹出烦人闪烁烦人，但有相反的效果。

• The library in question is SIMILE Timeline and its Ajax library;
• The event handler does call SimileAjax.DOM.cancelEvent(domEvt), which I assume based on the name cancels the bubbling of events;
• Just to make thing s more complicated, what I am actually doing is starting a timeout that if not cancelled by a moustout shows the pop-up, this being intended to prevent pop-ups flickering annoyingly but annoyingly having the reverse effect.

我不得不从另外一个戳，看看我能在哪里工作，我错了。 ： - ）

I'll have another poke at it and see if I can work out where I am going wrong. :-)

推荐答案

是，JavaScript是单线程的。即使是像谷歌的Chrome浏览器中，每个标签一个线程。

Yes, Javascript is single-threaded. Even with browsers like Google Chrome, there is one thread per tab.

不知道你是如何尝试取消从另一个弹出，很难说什么是你的问题的原因。

Without knowing how you are trying to cancel one pop-up from another, it's hard to say what is the cause of your problem.

如果您的DIV嵌套在彼此之内，你可能有一个<一个href=\"http://www.google.com/search?hl=en&client=firefox-a&rls=com.ubuntu:en-US:unofficial&hs=qp1&pwst=1&sa=X&oi=spell&resnum=0&ct=result&cd=1&q=javascript+event+propagation&spell=1\"相对=nofollow>事件传播问题。

If your DIVs are nested within one another, you may have an event propagation issue.

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