# # Meaningless Progress bars
APLawrence.com -  Resources for Unix and Linux Systems, Bloggers and the self-employed

Progress bars

I've removed advertising from most of this site and will eventually clean up the few pages where it remains.

While not terribly expensive to maintain, this does cost me something. If I don't get enough donations to cover that expense, I will be shutting the site down in early 2020.

If you found something useful today, please consider a small donation.



Some material is very old and may be incorrect today

© July 2005 Tony Lawrence

We all know that software progress bars have to be taken with a large helping of salt. It's not at all unusual for the bar to have no discernible relationship to reality, and this is particularly apt to be true for operating system installations and software startups. If any percentage indication is shown, it probably cannot be correlated to required time. The percentage is likely to hang in the same place for frustratingly long periods of time or suddenly jump large increments for no apparent reason. Part of this is because for complex tasks, it can be very difficult to estimate completion time, and part of it is surely just programmer laziness.

Mac OS X displays a "Starting MAc OS X" graphic with a lovely blue progress bar that crawls along quite convincingly. In fact, though, it's totally fake. A program called "WaitingForLoginWindow" draws that display, but it isn't really measuring anything - it's just a bar to keep you happy while OS X starts. Well, that's not entirely true. Actually, it's drawing a bar that is calculated to last approximately the same length of time it ran on the last startup. What happens is that the Login Window process kills off this bar display when it is ready to let you log in. The bar stores how long it ran in /var/db/loginwindow.boottime and then goes away. Next time it runs, it uses that stored value to decide how quickly to move the bar. Cute, isn't it?

Well, apparently there is reason and precedence for this deception: it makes users happy even if it is meaningless.. The Placebo Mini-Pattern explains why this is useful and generally a good idea.

See WAITINGFORLOGINWINDOW also.


If you found something useful today, please consider a small donation.



Got something to add? Send me email.





(OLDER)    <- More Stuff -> (NEWER)    (NEWEST)   

Printer Friendly Version

->
-> Meaningless Progress bars


Inexpensive and informative Apple related e-books:

Take Control of Automating Your Mac

Take Control of iCloud, Fifth Edition

Photos for Mac: A Take Control Crash Course

Are Your Bits Flipped?

Take Control of Parallels Desktop 12





More Articles by © Tony Lawrence





Printer Friendly Version

Have you tried Searching this site?

This is a Unix/Linux resource website. It contains technical articles about Unix, Linux and general computing related subjects, opinion, news, help files, how-to's, tutorials and more.

Contact us


Printer Friendly Version





The only problem with the cloud is that at some point it will rain. (Reinhard Posch)




Linux posts

Troubleshooting posts


This post tagged:



Unix/Linux Consultants

Skills Tests

Unix/Linux Book Reviews

My Unix/Linux Troubleshooting Book

This site runs on Linode