Keep packed acquisition arguments and callbacks alive across native calls - #10
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dylanebert wants to merge 3 commits into
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dylanebert wants to merge 3 commits into
dylanebert wants to merge 3 commits into
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* bridge: keep packed acquisition arguments and callbacks alive A CallArena holds every buffer a packed descriptor points into until the request callback runs; device error/loss callbacks live with the adapter; queue and pop-error-scope callback info stay referenced until completion. Version 0.1.7-shallot.1 with platform packages as optional dependencies so a git install finds its native library. * bridge: lock platform packages * bridge: link upstream PR in README
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Supersedes #9, which closed when its source branch was deleted. Same change, now on a branch that stays.
Problem
On bun-webgpu 0.1.7 (Bun 1.4.x), twenty
requestDevicecalls withBun.gc(true)forced between descriptor packing andwgpuAdapterRequestDeviceproduce descriptor drift: devices come back with features and limits that differ from the request, or acquisition fails outright.Cause
WGPUDeviceDescriptorStruct.pack(and every nested struct, string, enum/struct/primitive array and object-pointer array it packs) allocates ArrayBuffers that are only reachable through raw pointers written into the parent buffer. Nothing in JS holds them, so a collection before or during the native call frees memory Dawn is about to read. The same applies torequestAdapteroptions, the callback-info structs,queue.onSubmittedWorkDoneanddevice.popErrorScopecallback info (the pop-scope userdata buffer included). The device's uncaptured-error and device-lostJSCallbacks were locals too, even though native code calls them for the device's lifetime.Fix
structs_ffi.ts:CallArena, passed as a newarenapack option; every buffer a pack allocates (and every object whose.ptrit writes) joins it.requestAdapter/requestDevice: one arena per request, released after the request callback runs (or on failure).GPUAdapter: keeps the device error/loss callbacks referenced.GPUQueue.onSubmittedWorkDone,GPUDevice.popErrorScope: keep the callback info (and userdata) referenced until completion.Evidence
src/acquisition.test.ts: twenty acquisitions with a forced GC plus allocation churn wedged in front of the native call; each device's features and every limit must equal the request. Passes with the fix (800 expects, RTX 4090 / Vulkan, Bun 1.4.2); the existing suite is unchanged (186 pass, 1 skip).🤖 Generated with Claude Code
https://claude.ai/code/session_01FFh77i2dpmMjbVhbEUd5qX