1894005 - Investigate adding a per-script alloc site

Status: ASSIGNED

(Core :: JavaScript: GC, task, P2)

Description

[Jon Coppeard (:jonco) (PTO until 5th Jan)]

For objects we've added allocation sites for two specific allocation paths, but there are many places we don't have this. Rather than add alloc sites in every possible location it may be worthwhile adding a per-script allocation site. This would be a more coarse grained fallback but one that is much simpler to implement. (Currently we disable nursery string allocations on a per-zone basis which is like and even more coarse grained setup.)

Comment 1

[Jon Coppeard (:jonco) (PTO until 5th Jan)]

Attachment: Bug 1894005 - Allow UniquePtrs to be used in WeakCache hash maps r?sfink

The problem here is that we copy the keys/values in entryNeedsSweep. I tried
several strategies to avoid this but in the end the simplest thing to do was
add a needsSweep method to the GC policy templates that calls
IsAboutToBeFinalized. I've implemented this only where necessary (and WeakCache
is only used internally nowadays).

Comment 2

[Phabricator Automation]

Comment on attachment 9400473 [details]
Bug 1894005 - Allow UniquePtrs to be used in WeakCache hash maps r?sfink

Revision D209687 was moved to bug 1895462. Setting attachment 9400473 [details] to obsolete.