(no subject)

[torkell]

Why are Firefox and Opera apparently incapable of running multiple processes for the same user?

The only reason I can think of is because the necessary profile locking is "hard". So why has Internet Explorer been able to do this for ages without any problems?

Comments

[crschmidt.livejournal.com]

Firefox has no problems doing that. Use -ProfileManager -no-remote on the command line to start it. It's not the default because when people click on a new link in an IM window, they don't expect it to open in a new browser.

Opera, I don't know anything about.

[torkell]

I've heard about the first one, but apparently it can cause profile corruption and is not supported.

[crschmidt.livejournal.com]

ProfileManager can? or -no-remote can? I use both all the time.

[torkell]

Whichever combination lets you have multiple Firefox processes with the same profile. The reports I found weren't specific, and I think probably mean "we didn't do anything to make sure it wouldn't corrupt profiles".

[crschmidt.livejournal.com]

Why do you need multiple processes with the *same* profile? I guess I didn't understand the use case, I'm sorry.

[torkell]

The main reason is proper session isolation. As things stand, if one tab crashes (e.g. due to a bug in a plugin), I lose all tabs in all Firefox windows. This isn't the case in Internet Explorer, which can have multiple processes for the same profile.

You can also run into problems even without crashing plugins - I have seen Opera slow to a crawl when opening lots of tabs, but unlike IE I don't have the option of starting a new process to use while the previous one is still loading stuff.

[tau-iota-mu-c.livejournal.com]

I didn't even need the -no-remote when I tried this last.

If you try to create a new profile when another profile is open, then the database telling firefox where the profiles are gets confused because mozilla programmers are a pack of morons. If you close the second firefox after the first one, it tends to work in practice. If not, you just lose the location of the second profile. You can recreate it, and it'll use the old directory and continue to use its old settings. Or maybe I had to edit one of the .js files to point to the old location...

[tau-iota-mu-c.livejournal.com]

Ah, woops, missed the bit about the same profile...

[torkell]

And it doesn't actually work in Firefox 2.0.0.11 on Windows. I can choose separate profiles for each process, but can't share one profile across multiple processes. I'll try a more recent version at some point.