1520645 - Improve vector recycling to avoid heap allocations

Status: RESOLVED FIXED

(Core :: Graphics: WebRender, enhancement)

Description

[Dzmitry Malyshau [:kvark]]

The old vector recycler (see recycle_vec) had a few problems:

1. shrinking to fit would be inevitably followed by re-allocation, since it's unlikely that the consequent sizes are below the immediately followed frames
2. shrinking before clearing means that the existing contents are copied over, which is a waste

Comment 1

[Dzmitry Malyshau [:kvark]]

Attachment: WR improved vector allocation recycler

The old vector recycler had a few problems:        
  1. shrinking to fit would be inevitably followed by re-allocation, since it's unlikely that the consequent sizes are below the immediately followed frames
  2. shrinking before clearing means that the existing contents are copied over, which is a waste

The new code has more complicated logic for recycling, aimed at reducing heap allocations. It's also collecting the statistics.

Comment 2

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/bf95c0c1f962
WR improved vector allocation recycler r=nical

Comment 3

[Arthur Iakab [arthur_iakab]]

https://hg.mozilla.org/mozilla-central/rev/bf95c0c1f962