Add GRVkBackendContext.DeviceLost managed binding (#4601)

[ramezgerges]

Description

Fixes #4601. Exposes Skia's Vulkan device-lost callback on GRVkBackendContext and SKGraphiteVkBackendContext so managed callers can register a VK_ERROR_DEVICE_LOST handler — the intended channel for reacting to TDRs / driver resets. Wraps the new C API added in the companion mono/skia PR.

Related issues

Fixes #4601

Required skia PR

Requires mono/skia#338

Areas affected

• Managed API (binding/)
• Native / C API (externals/skia/src/c, include/c)
• Generated P/Invoke bindings
• Native dependency or Skia update
• Views & integrations
• Rendering output / visual behavior
• Performance
• Tests
• Build, packaging, or CI
• Documentation or samples

Changes

Public API

ABI-stable additive changes only.

public delegate void GRVkDeviceLostDelegate(GRVkDeviceLostInfo info);

public enum GRVkDeviceFaultAddressType { None, ReadInvalid, WriteInvalid, ExecuteInvalid,
    InstructionPointerUnknown, InstructionPointerInvalid, InstructionPointerFault }

public readonly struct GRVkDeviceFaultAddressInfo { AddressType, ReportedAddress, AddressPrecision }
public readonly struct GRVkDeviceFaultVendorInfo  { Description, VendorFaultCode, VendorFaultData }

public sealed class GRVkDeviceLostInfo {
    string Description;                              // Skia's message
    GRVkDeviceFaultAddressInfo[] AddressInfos;       // from VK_EXT_device_fault
    GRVkDeviceFaultVendorInfo[]  VendorInfos;        // from VK_EXT_device_fault
    byte[] VendorBinaryData;                         // raw vendor blob
}

public GRVkDeviceLostDelegate GRVkBackendContext.DeviceLost { get; set; }
public GRVkDeviceLostDelegate SKGraphiteVkBackendContext.DeviceLost { get; set; }

Behavior

• Ganesh Vulkan + Graphite Vulkan callers who set DeviceLost now receive a full-fidelity callback on the driver-owned thread whenever Skia detects VK_ERROR_DEVICE_LOST. The payload includes Skia's description string plus the complete VK_EXT_device_fault output (address-info array, vendor-info array, vendor binary blob).
• The passed GRVkDeviceLostInfo is a snapshot — the marshalling proxy copies everything out of Skia's transient std::string / std::vector storage into managed arrays, so handlers may safely stash the object past the callback's return (e.g. to log later, dispatch to a UI thread).
• Lifetime rule (documented): GRVkBackendContext / SKGraphiteVkBackendContext must outlive the GRContext / SKGraphiteContext built from it. Skia holds the callback pointer non-owning on the Context and calls it later; the pin lives on the backend context. Same rule that already applies to GetProcedureAddress. Standard using block ordering handles this naturally.
• When VK_EXT_device_fault is not enabled by the app, the address/vendor arrays and binary data are empty; the description is still populated.
• Callers who leave DeviceLost null get today's behavior.

Testing

Two test files:

• tests/Tests/SkiaSharp/GRVkDeviceLostProxyTest.cs — 5 proxy-level unit tests that invoke DelegateProxies.GRVkDeviceLostProxy directly with synthesized GRVkDeviceLostInfoNative payloads, verifying each marshalling path: description, address-info array, the manual byte-offset walk for vendor infos (the generator emits char[256] as a pointer, so the proxy walks the array with byte* arithmetic), vendor binary blob copy, and exception swallowing.
• tests/VulkanTests/GRVkDeviceLostTest.cs — 5 Vulkan integration tests: property round-trip on both backend contexts, Ganesh + Graphite Context construction with a handler survives full Snap/Insert/Submit/Dispose cycle, repeated setter assignment doesn't leak or double-free.

Re-verified after rebasing onto main (post chrome/m154 and post the per-type binding split in #5056), on Windows x64 with natives rebuilt from source:

Suite	main baseline	This branch	Delta
Core (SkiaSharp.Tests)	6153 pass / 169 fail / 30 skip	6164 pass / 169 fail / 30 skip	+11 pass, +0 fail
Vulkan	4 pass / 21 fail	7 pass / 23 fail	+3 pass, +2 fail
Direct3D	5 pass / 0 fail	5 pass / 0 fail	—
SingletonInit	1 pass / 0 fail	1 pass / 0 fail	—

The +11 core passes are the 5 new proxy tests plus 6 new ApiTests theory cases (3 theories x the 2 new P/Invokes). Core failures are byte-identical to the baseline.

The failures on that machine are environmental, not regressions. That box has no Vulkan ICD and no usable OpenGL context, so the pre-existing GPU failures reproduce identically on unmodified main: all 169 core failures are System.Exception : DC does not have extensions, and all Vulkan failures are vkCreateInstance failed / SharpVk.IncompatibleDriverException. Per the GPU policy these are correctly failures rather than skips, and this change does not add or widen any skip.

Confirmed on real GPU hardware

The suite was then re-run on a machine with a working Vulkan driver (Intel UHD Graphics 620, driver 31.0.101.2137), in an interactive console session:

Suite	Result
SkiaSharp.Vulkan.Tests (incl. all 5 new device-lost tests)	30 pass / 0 fail / 0 skip

All five GRVkDeviceLostTest cases pass against a real Vulkan device, including the two that build a live GRContext / SKGraphiteContext with a handler installed and take it through a full Snap/Insert/Submit/Dispose cycle. Nothing in this change is left unverified by the CPU-only run.

Actually firing VK_ERROR_DEVICE_LOST still requires hardware experiencing a TDR, which remains out of reach in CI and on a healthy dev machine — that specific path is covered by the proxy tests, which drive the marshalling directly.
Actually firing VK_ERROR_DEVICE_LOST requires hardware experiencing a TDR — unreachable in CI. The proxy tests cover the marshalling; the integration tests cover the wiring.

Checklist

• Tests added or updated (if omitted, explain why above)
• Changes above lists all public API and behavioral changes (or "None.")
• New/changed public API? Filed a docs issue in mono/SkiaSharp-API-docs so reference docs can be written later
• Native change? Companion mono/skia PR linked above and bindings regenerated

[github-actions]

📦 Try the packages from this PR

Warning

Do not run these scripts without first reviewing the code in this PR.

Step 1 — Download the packages

bash / macOS / Linux:

curl -fsSL https://raw.githubusercontent.com/mono/SkiaSharp/main/scripts/get-skiasharp-pr.sh | bash -s -- 4655

PowerShell / Windows:

iex "& { $(irm https://raw.githubusercontent.com/mono/SkiaSharp/main/scripts/get-skiasharp-pr.ps1) } 4655"

Step 2 — Add the local NuGet source

dotnet nuget add source ~/.skiasharp/hives/pr-4655/packages --name skiasharp-pr-4655

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Or download manually from Azure Pipelines — look for the nuget artifact on the build for this PR.

Remove the source when you're done:

dotnet nuget remove source skiasharp-pr-4655

[dotnet-policy-service]

Hey there @@ramezgerges! Thank you so much for your PR! Someone from the team will get assigned to your PR shortly and we'll get it reviewed.

[mattleibow]

/azp run

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