[perf] UIRenderer::Dispatch heap-allocates a std::vector per custom dispatch (UI-WebGPU.cpp) #132

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opened 2026-06-17 21:18:56 +02:00 by jorijnvdgraaf · 0 comments

jorijnvdgraaf commented

2026-06-17 21:18:56 +02:00

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Found by an adversarially-verified performance audit (confirmed real after a skeptic pass).

Location: implementations/Crafter.Graphics-UI-WebGPU.cpp:180-207
Severity: low · Effort: trivial · Category: allocation

Problem

UIRenderer::Dispatch builds a std::vector<uint32_t> handles with reserve, forcing one malloc+free per dispatch; custom compute dispatches run per-frame. The count is bounded and known at pipeline-load.

Fix

Fixed-capacity std::array<uint32_t, kMaxBindings> or a reused thread_local vector. Secondary WebGPU path, modest absolute cost.

Found by an adversarially-verified performance audit (confirmed real after a skeptic pass). **Location:** `implementations/Crafter.Graphics-UI-WebGPU.cpp:180-207` **Severity:** low · **Effort:** trivial · **Category:** allocation ### Problem `UIRenderer::Dispatch` builds a `std::vector<uint32_t> handles` with `reserve`, forcing one malloc+free per dispatch; custom compute dispatches run per-frame. The count is bounded and known at pipeline-load. ### Fix Fixed-capacity `std::array<uint32_t, kMaxBindings>` or a reused `thread_local` vector. Secondary WebGPU path, modest absolute cost.

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2026-06-18 15:49:08 +02:00