Can't share or open `IOSurface` cross process

[thenextman]

Steps to Reproduce

1. Try to use any function to share an IOSurface cross-process on macOS

Expected Behavior

The functions to share and lookup IOSurface should be exported; e.g.

IOSurfaceCreateMachPort
IOSurfaceCreateXPCObject
IOSurfaceLookupFromMachPort
IOSurfaceLookupFromXPCObject

Ideally, I'd also expect to be able to call the deprecated function IOSurfaceLookup. I can manually use IOSurfaceIsGlobal and IOSurfaceGetID, but how do I call the lookup? P/invoking it with a return type of IntPtr isn't helpful when I need an IOSurface to pass to other functions.

Actual Behavior

The functions are not available.

Environment

Visual Studio Professional 2022 for Mac
Version 17.5.3 (build 15)
Installation UUID: 4693e2b8-e552-4d2a-9994-cef0d37548ad

Runtime
.NET 7.0.1 (64-bit)
Architecture: Arm64
Microsoft.macOS.Sdk 12.3.2372; git-rev-head:754abbf6a3563f6267e5717ae832b4ac25b1f2fb; git-branch:release/7.0.1xx-xcode13.3

Roslyn (Language Service)
4.5.0-3.23056.2+97881342e427ff5cdcba8f12b12ff8e6f3564431

NuGet
Version: 6.4.0.117

.NET SDK (Arm64)
SDK: /usr/local/share/dotnet/sdk/7.0.202/Sdks
SDK Versions:
7.0.202
7.0.200
7.0.102
7.0.101
7.0.100
6.0.407
6.0.406
6.0.405
6.0.404
6.0.403
6.0.402
6.0.401
6.0.302
6.0.300
6.0.101
MSBuild SDKs: /Applications/Visual Studio.app/Contents/MonoBundle/MSBuild/Current/bin/Sdks

.NET SDK (x64)
SDK Versions:
6.0.407
6.0.406
6.0.405
6.0.404
6.0.403
6.0.402
6.0.401
6.0.302
6.0.105
6.0.102
6.0.101
5.0.408
5.0.405
5.0.404
3.1.426
3.1.425
3.1.424
3.1.423
3.1.421
3.1.419
3.1.416

.NET Runtime (Arm64)
Runtime: /usr/local/share/dotnet/dotnet
Runtime Versions:
7.0.4
7.0.3
7.0.2
7.0.1
7.0.0
6.0.15
6.0.14
6.0.13
6.0.12
6.0.11
6.0.10
6.0.9
6.0.7
6.0.5
6.0.1

.NET Runtime (x64)
Runtime: /usr/local/share/dotnet/x64/dotnet
Runtime Versions:
6.0.15
6.0.14
6.0.13
6.0.12
6.0.11
6.0.10
6.0.9
6.0.7
6.0.5
6.0.2
6.0.1
5.0.17
5.0.14
5.0.13
3.1.32
3.1.31
3.1.30
3.1.29
3.1.27
3.1.25
3.1.22

Xamarin.Profiler
Version: 1.8.0.49
Location: /Applications/Xamarin Profiler.app/Contents/MacOS/Xamarin Profiler

Updater
Version: 11

Apple Developer Tools
Xcode: 14.2 21534
Build: 14C18

Xamarin.Mac
Version: 9.1.0.5 Visual Studio Professional
Hash: 7738c90
Branch: xcode14.2
Build date: 2023-01-25 15:56:14-0500

Xamarin.iOS
Version: 16.2.0.5 Visual Studio Professional
Hash: 7738c90
Branch: xcode14.2
Build date: 2023-01-25 15:56:15-0500

Xamarin Designer
Version: 17.5.3.47
Hash: e8b5d371c3
Branch: remotes/origin/d17-5
Build date: 2023-03-23 18:30:22 UTC

Xamarin.Android
Version: 13.2.0.0 (Visual Studio Professional)
Commit: xamarin-android/d17-5/797e2e1
Android SDK: /Users/rmarkiewicz/Library/Developer/Xamarin/android-sdk-macosx
Supported Android versions:
12.0 (API level 31)
11.0 (API level 30)
10.0 (API level 29)
9.0 (API level 28)
13.0 (API level 33)

SDK Command-line Tools Version: 7.0
SDK Platform Tools Version: 33.0.2
SDK Build Tools Version: 32.0.0

Build Information:
Mono: 6dd9def
Java.Interop: xamarin/java.interop/main@149d70fe
SQLite: xamarin/sqlite@fdc1e34
Xamarin.Android Tools: xamarin/xamarin-android-tools/main@9f02d77

Microsoft Build of OpenJDK
Java SDK: /Library/Java/JavaVirtualMachines/microsoft-11.jdk
11.0.16.1
Android Designer EPL code available here:
https://github.com/xamarin/AndroidDesigner.EPL

Eclipse Temurin JDK
Java SDK: /Library/Java/JavaVirtualMachines/temurin-8.jdk
1.8.0.302
Android Designer EPL code available here:
https://github.com/xamarin/AndroidDesigner.EPL

Android SDK Manager
Version: 17.5.0.33
Hash: f0c0c52
Branch: remotes/origin/d17-5~2
Build date: 2023-03-23 18:30:27 UTC

Android Device Manager
Version: 0.0.0.1245
Hash: 7f8a990
Branch: 7f8a990
Build date: 2023-03-23 18:30:27 UTC

Build Information
Release ID: 1705030015
Git revision: c7ec3826dd11045a53fa7f2c08ddbd6bd475c05b
Build date: 2023-03-23 18:28:33+00
Build branch: release-17.5
Build lane: release-17.5

Operating System
Mac OS X 13.4.0
Darwin 22.5.0 Darwin Kernel Version 22.5.0
Mon Apr 24 20:52:24 PDT 2023
root:xnu-8796.121.2~5/RELEASE_ARM64_T6000 arm64

Enabled user installed extensions
Project System Tools 0.12

[rolfbjarne]

The DllImports and helper functions would be something like this:

using System.Runtime.InteropServices:
using ObjCRuntime;

static class IOSurfaceHelpers {
	[DllImport ("/System/Library/Frameworks/IOSurface.framework/IOSurface")]
	// mach_port_t IOSurfaceCreateMachPort(IOSurfaceRef buffer);
	static extern /* mach_port_t */ uint IOSurfaceCreateMachPort (/* IOSurfaceRef */ IntPtr buffer);

	[DllImport ("/System/Library/Frameworks/IOSurface.framework/IOSurface")]
	// xpc_object_t IOSurfaceCreateXPCObject(IOSurfaceRef aSurface);
	static extern /* xpc_object_t */ IntPtr IOSurfaceCreateXPCObject (/* IOSurfaceRef */ aSurface);

	[DllImport ("/System/Library/Frameworks/IOSurface.framework/IOSurface")]
	// IOSurfaceRef IOSurfaceLookupFromMachPort(mach_port_t port);
	static extern /* IOSurfaceRef */ IntPtr IOSurfaceLookupFromMachPort (/* mach_port_t */ uint port);

	[DllImport ("/System/Library/Frameworks/IOSurface.framework/IOSurface")]
	// IOSurfaceRef IOSurfaceLookupFromXPCObject(xpc_object_t xobj);
	static extern /* IOSurfaceRef */ IntPtr IOSurfaceLookupFromXPCObject (/* xpc_object_t */ IntPtr xobj);

	[DllImport ("/System/Library/Frameworks/IOSurface.framework/IOSurface")]
	// IOSurfaceRef IOSurfaceLookup(IOSurfaceID csid);
	static extern /*  IOSurfaceRef */ IntPtr IOSurfaceLookup (/* IOSurfaceID */ int csid);

	public static uint CreateMachPort (this IOSurface buffer)
	{
		return IOSurfaceCreateMachPort (buffer.Handle);
	}

	public static NSObject CreateXpcObject (this IOSurface aSurface)
	{
		var rv = IOSurfaceCreateXPCObject (aSurface.Handle);
		return Runtime.GetNSObject (rv);
	}

	public static IOSurface LookupFromMachPort (uint port)
	{
		var rv = IOSurfaceLookupFromMachPort (port);
		return (IOSurface) Runtime.GetNSObject (rv);
	}

	public static IOSurface LookupFromXpcObject (NSObject xobj)
	{
		var rv = IOSurfaceCreateXPCObject (xobj.Handle);
		return (IOSurface) Runtime.GetNSObject (rv);
	}

	public static IOSurface Lookup (int csid)
	{
		var rv = IOSurfaceLookup (csid);
		return (IOSurface) Runtime.GetNSObject (rv);
	}
}

Can you try these and see if it works for you?

[thenextman]

Hi @rolfbjarne

This is working great, thank you!

[rolfbjarne]

Reopening, since we'll want to add these APIs at some point.