On 15/01/2016 05:50, Nick Fitzgerald wrote: > Hi folks! > > Dominator trees give you fine-grained insight into memory retention. > > In a graph rooted by some node R, a node A is said to dominate B iff > every path to B starting from R passes through A. In the context of a > heap graph, another way to say this would be that A is retaining B: > if the garbage collector found A to be unreachable and eligible for > reclaiming, than B would also be unreachable and eligible for > reclaiming. > > We also use this to calculate the "true" memory cost of a node in the > heap graph. This is the "retained size" and contrasts with the naive > "shallow size". For example, imagine a large binary tree where there > are no outside references into subtrees, only to the root. The root > node itself has a small shallow size: a left branch pointer, a value, > and a right branch pointer. However, it is retaining the whole rest > of this large tree's structure, and so its retained size is > significant. > > Here is a screenshot of the dominator tree (combined with allocation > stack tracking) in action to debug the memory overhead of loading > large source files in a CodeMirror editor: > http://i.imgur.com/sGsVJb9.png > > And here is a reminder of how to enable to memory tool within the > devtools: http://i.imgur.com/hEPTqrT.png > > If you would like to use this tool for the whole runtime rather than > scoped to a single tab, use the browser toolbox. Here are > instructions for enabling and using the browser toolbox: > https://developer.mozilla.org/en-US/docs/Tools/Browser_Toolbox > > Please try it out, give me your feedback, and file bugs in the > "Firefox" product and "Developer Tools: Memory" component! > > My thanks to the folks who reviewed patches for this feature: Jordan > Santell, Steve Fink, Boris Zbarsky, and Jim Blandy. > > Cheers, > > Nick
This is great! Is there a way of expanding/collapsing the whole tree? Thunderbird uses "\" (collapse) and "*" (expand). Nitpick: The columns don't appear to be resizeable. Here is how the Browser Toolbox looks like in SeaMonkey! https://bug1223341.bmoattachments.org/attachment.cgi?id=8708680 Phil -- Philip Chee <phi...@aleytys.pc.my>, <philip.c...@gmail.com> http://flashblock.mozdev.org/ http://xsidebar.mozdev.org Guard us from the she-wolf and the wolf, and guard us from the thief, oh Night, and so be good for us to pass. _______________________________________________ dev-platform mailing list dev-platform@lists.mozilla.org https://lists.mozilla.org/listinfo/dev-platform
