02-22-09 - Awesome Windows-Firefox Bug

I've written before about how explorer.exe does some weird shit that you can only see when you put the system under very heavy CPU load. Well today I'm running Relacy iterations to test my lock-free stuff (more on this soon, I promise), and it takes like 24 hours + to run a hard core test so I'm browsing the web while it's running. It pegs the CPU at 99% so explorer is really dogging. So I've discovered that when you drag a link to the desktop to make a bookmark, it doesn't read your mouse cursor position right then and make the icon there. It waits until the icon is actually created, first it creates the icon at some default spot over in the top left, and then it reads the mouse position and moves it there. Normally this isn't a big deal, but when it takes multiple seconds to make the icon, it can show up at some spot very far from where you dragged it (and you can lose it completely - for example it's often made under some window)

(I assume this is an explorer.exe bug, but I haven't found a repro outside of firefox, hence the ambiguous attribution in the title).

Of course Windows is full of so many crash bugs that they rightly put all the janky bad-timing and bad-behavior bugs at low priority.

1 comment:

msnopenid said...

This is an explorer bug. You can reproduce it just by copying something to the desktop that will take a long time, e.g., a 200 MB file.

old rants