history plot hang with 100% use

[dd1]

Reporting a hang, web page unresponsive, 100% cpu use, cannot open javascript debugger. How to get there? On the following plot (note that graph low limit is usually set to 1.5, needs to be set to 0 for this test),

click on the graph point inside the “+” button, you will zoom in (good), zoom out to get back.

move the mouse to the data point (data value and time overlay will open) and click on roughly the top of letter “3” and the page will hang. (all the detail is to reproduce the problem, what I was actually doing was clicking on the “+” button but missed it and clicked just below it).

https://daq16.triumf.ca/?cmd=History&group=PWB&panel=v_p2&A=1594164872&B=1594165212

One the page is hung, the only thing I can do is close the tab. So I open the javascript debugger beforehand. Once the page is hung, the profiler does not work (hangs the page). But “source” “pause script execution” works and shows this stack trace: (cannot cut-and-paste it, WTF!)

MHistoryGraph.mouseEvent → redraw → requestAnimationFrame → draw → drawTAxis (line 2713).

K.O.

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[Stefan Ritt]

The problem can actually be reproduced by just clicking on an x or y axis label (outside the graph, but in the axis label area). Fixed in current commit.

[dd1]

confirmed fixed. K.O.