639235 - mark watch points after the main GC phase

Status: RESOLVED FIXED

(Core :: JavaScript Engine, defect)

Description

[Andreas Gal :gal]

This patch adds an iterative weak pointer marking phase after the main GC is done. We will soon add another types of weak roots int there, so the infrastructure is a good addition anyway. This makes our object mark path a little slimmer.

Comment 1

[Andreas Gal :gal]

Attachment: patch

Comment 2

[Brendan Eich [:brendan]]

Comment on attachment 517204 [details] [diff] [review]
patch

while (true) { if (!foo()) break; ... } is just while (foo()) { ... }, but if you are trying to future-proof, how will adding more if (!foo2()) break; statements scale? Won't you need to break on any false return, but only after calling all?

Jason should be in on this for the watchpoint overhaul he's doing.

/be

Comment 3

[Jason Orendorff [:jorendorff]]

Comment on attachment 517204 [details] [diff] [review]
patch

This doesn't pose any problems for the watchpoint rewrite.

It's scary, because the worst-case performance is O(n^2)... in the GC mark phase, which seems bad. I sure don't know a better way to implement WeakMap, though, and what's good enough for WeakMap is surely good enough for the watchpoint table.

r=me, no nits.

Comment 4

[Andreas Gal :gal]

http://hg.mozilla.org/tracemonkey/rev/97fb5391ed75

Comment 5

[Chris Leary [:cdleary] (not checking bugmail)]

http://hg.mozilla.org/mozilla-central/rev/97fb5391ed75