[chit-chat] Evil Console

[kocoten1992]

You know, I love debugging in console, then come this b*ch, it got me real good (when I'm about to hate javascript).

To meet this b*ch, do as follow:

• Open a new tab (chrome or firefox), and F12 that tab
• Open Task Manager (or anything that able to see RAM usage)
• Notice current usage RAM, type in window.x = new Uint8Array(100000000) several times. (don't delete any previous command), just keep paste in and enter.

Hypothetically - when you enter a new window.x = new Uint8Array(100000000), a previous one should be uNrEaChAbLe, because we haven't reference it anywhere therefor there is no way you able to call it out anymore.

Shouldn't it be collected by now ? Take a look of your memory ( 😈 muahahahah)

Now close F12 and open it again, take a look of your memory again ( 👿 )

So exactly what happen ?

Remember before, I told you to not delete previous command, you know why ?

We can't retrieve the previous window.x for sure, but it is still link, the link are the text on the console log. ( 😮 )

window.x = new Uint8Array(100000000) // the text itself are the evil
Uint8Array(100000000) [0, 0, 0…] // the evil

You could try to do it again by delete the text on console, and memory will be release too.

The example above is cute ;) , but consider a more sophisticated where it drive you insane:

• You download each segment of file (like webseed or use mediasource), you sure that after each download, you delete buffer alright ...... and memory still not release. (while f12 is open - of course)

Try to close f12 and reopen it - for the love of god, the text or even the request in tab network could still link to buffer 😖

[DiegoRBaquero]

@kocoten1992 I don't really understand this issue in the context of webtorrent, could you explain a bit further?

[kocoten1992]

@DiegoRBaquero kinda relevant, cause I thought here as like a mini forum for sharing idea and experience in develop webtorrent ... hence this post.

Webtorrent dev will face with big file, just remind that when you open console, it could be the reason that memory won't go away.

[DiegoRBaquero]

When I close the console it does go away. Even without nulling or deferencing it.

[kocoten1992]

Ye, the act of close the console actually dereference it, another way is:

// Ctrl + L (clear console - dereference)
// Then go to Memory Tab, click Collect Garbage
// It work too