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Comment by Brushfire | Hacker News Reader

It handles it less gracefully than I would have assumed. If you are running flash in multiple Chrome windows, this will corrupt ALL of them, instead of just the one visiting the page linked above. Wasnt one of Chrome's huge selling features the idea of memory independence?

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Memory independence + plugin that isn't designed to run multiple processes = plugin that can only run in one process. Imagine if Flash, forced into running twice, tried to read and write from the same cookie / any other kind of data, without any concurrency tools of any kind.

Chrome has to run Flash how Flash wants to be run, because doing otherwise could cause massive problems with any plugin. This is part of why it took so long for them to make Chrome, resolving the memory independence desires with the needs of plugins requires giving some things up. It was either roughly all plugins in existence, or allow the same process to interact with multiple tabs / windows.

This sounds a bit fishy to me. Of course Flash can be run from multiple processes simultaneously since it naturally runs inside of multiple browsers simultaneously, and I assume Chrome has some internal (socket based?) IPC that they're using anyway...

Part of the difficulty is that this problem applies to all plugins. Flash may be able to handle it just fine, in which case it could just be a poor plugin, but what about any other plugin out there?

Heck, Firefox uses a lock-file in your profile to prevent multiple instances from running. What's to stop a plugin from requiring such a file, writing / reading it frequently, and having no error handling because it's only designed to run singly? Ultimately, you either harden the separations to run multiple instances of it, breaking many in the process and possibly damaging data irrecoverably, or you just let the plugin decide and have backwards compatibility, which is hugely important for a browser.

Flash on multiple browsers has completely separate cookie and data stores. Flash on a single browser has a single cookie and data store. Without introducing a complex forking/merging infrastructure for that data (which only Adobe would be able to create anyway) you're stuck with a single process for the plugin for all of the tabs in a single browser.

Flash actually has one cookie & data store. It exists between browsers.

You can see your flash cookies at this website:

http://www.macromedia.com/support/documentation/en/flashplay...

You'll notice that they are the same no matter what browser you use.

This page crashed flash for me! Wow!

Interestingly enough the "libflashplugin.so" bar popped up on Gmail for me the last time that all my Flash instances crashed. I never realized that GMail used Flash. (The bar only seemed to pop up on tabs that were using Flash, not all tabs had the warning at the top)

Gmail uses flash for the file upload progress bar when adding an attachment. Will HTML5 allow developers to add this feature?

Flash is also used to make that popping sound when you get a gtalk message.

It is? Why?

Don't know about HTML5 (I can hope), but it can be accomplished with JS + hidden iframe for uploading. I think it requires querying the server for the progress, but I could be wrong there.

Flash is to blame for that one.

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