Bug 295749 – Deprecate FastMalloc macro for new types

• Status: RESOLVED
• Resolution: FIXED
• Component: New Bugs

[Marcus Plutowski]

rdar://155564529

TZone is fully deployed, and is essentially perf-neutral. We want to move every type that we can from FastMalloc to TZoneMalloc, but don't want to do so all at once due to stability concerns / the possibility of novel perf regressions. Moreover, there are types with variable-width sizes (e.g. trailing arrays) which cannot always / generally be allocated with TZones.

As such, we should do the following:
  1. Change the macro name to make it clear that it should not be used by new types
  2. Update the documentation in FastMalloc.h to point developers towards using TZoneMalloc
  3. Update FastMalloc to take in the class-name as a parameter to make it easier to handle the transition.

[Marcus Plutowski]

Pull request: https://github.com/WebKit/WebKit/pull/47897

[EWS]

Committed 297491@main (d9db853f14ab): <https://commits.webkit.org/297491@main>

Reviewed commits have been landed. Closing PR #47897 and removing active labels.

[EWS]

Committed 297506@main (411f20469889): <https://commits.webkit.org/297506@main>

Reviewed commits have been landed. Closing PR #48165 and removing active labels.

[Marcus Plutowski]

Re-opening for pull request https://github.com/WebKit/WebKit/pull/48188

[EWS]

Committed 297540@main (37d4a6880db9): <https://commits.webkit.org/297540@main>

Reviewed commits have been landed. Closing PR #48188 and removing active labels.