Datepicker: Memory leak in IE7

Hi DysprosiumDy, thanks for taking the time to contribute to the jQuery UI project. We're going to need a test case that shows the memory leak in order to look into this. For example, see #8164.

Because we get so many tickets, we often need to return them to the initial reporter for more information. If that person does not reply within 14 days, the ticket will automatically be closed, and that has happened in this case. If you still are interested in pursuing this issue, feel free to add a comment with the requested information and we will be happy to reopen the ticket if it is still valid. Thanks!

I request this case to be reopened. I've got a good test case here to reproduce the issue. Apologies that I didn't do this earlier. I did not use jsfiddle because I wanted the page to be as clean as possible. The examples below are therefore hosted on my own server.

Page 1: Datepicker included

• URL: http://www.boardgame-online.com/jqueryui/datepicker.html

Page 2: Datepicker not included

• URL: http://www.boardgame-online.com/jqueryui/nodatepicker.html

I'm using jQuery 1.8.3 and jQuery UI 1.9.2, but the issue is not limited to these versions as mentioned before. On page 1 you can simply refresh the page using IE7 to see memory usage increase by about 2.5 MB each time. This goes on indefinitely. On page 2 you can do the same and will notice no increase in memory usage.

If you want any additional information, I'll be more than happy to provide it!

I'm not seeing anything on those pages other than the jQuery and jQuery UI scripts being included. So the inclusion of the datepicker script itself is causing a leak?

Indeed. We first noticed this problem about a year ago. It took us two days of debugging to discover the source of the memory leak. Our webservice included the datepicker, but didn't use it. We've excluded the datapicker widget ever since. Our customers simply couldn't properly use our service, since they all run IE7.

Interesting, I do see the leak. We might be able to close #4188 because this is a far more specific example.

Unfortunately we probably won't get around to fixing until the datepicker rewrite lands in master, although pull requests are welcome.

Hi All,

How do we get all the instances of datepickers in a page ?

I am using $(window).datepicker("destroy");

But I dont think it will destroy all the controls ?

Any suggestions please ?

Replying to [comment:7 maverick9984]:

Hi All, How do we get all the instances of datepickers in a page ? I am using $(window).datepicker("destroy"); But I dont think it will destroy all the controls ? Any suggestions please ?

maverick9984,

For support use Stack Overflow, the[http://forum.jquery.com/ forums] or #jquery on IRC.

We saw this bug over 1 year ago as well.

When we profiled into it, this is what we found (as nonsensical as it may sound):

• The memory leak is created by merely included the datepicker definition on the page
• Once the datepicker definition is included on the page, the use of ANY jQuery UI widget causes memory leakage
• Strangest of all: if you simply USE the datepicker on the page, the memory leak goes away

In other words, it is only a problem for us in IE7 if the datepicker is included (defined) on the page but is NOT used. Therefore, our workaround is to always keep datepicker as a separate script and only include it on pages where we know we will use it.

IIRC, this is all caused by IE7's shortcoming in the area of not correctly unlinking references to the table elements when they are removed/destroyed from the live DOM... which is why it seems even stranger that the leakage is caused by the definition of the widget rather than the use of it. o_O

Crazy ole IE7....

At this point, we're not going to spend any more time trying to track this down. Datepicker is being rewritten from scratch, and the new version isn't likely to have whatever problem the current version has. If someone wants to send a pull request, we'll gladly review it.