swung0x48andClaude Opus 5
207c31f6db
The cross-process session is up. A server process is started on its own with an
endpoint and nothing else, it listens; a client started separately connects to
that name; Hello crosses, Welcome comes back with four SegmentRefs, six
descriptors cross by SCM_RIGHTS, and the client maps memory another process
created. ClientSession::Active() is non-null at the end of it, which is the flag
that arms the thirty-seven wire emitters.
INDEPENDENT, NOT FORKED - and that is a correction to this package's first
shape. The version committed an hour ago forked the server and handed it fds
3..6. It worked, and it was less code, but inheritance can only ever produce a
server that is a CHILD OF ITS CLIENT, which is the one arrangement the end state
cannot use: there the server is a standing application and the client is
somewhere else entirely, possibly on another kernel. CONTRACT-P6 §3.1 called
this Dial == Connect and filed it as a later shape. It is the primary one, and
fork/execve survives only as a way to START a process - every descriptor it used
to carry is gone.
What that costs and buys, concretely: the rendezvous becomes a NAME, so
SocketTransport grows Listen/AcceptPair/ConnectTo, with a bounded connect retry
that is the CLIENT's (a launcher that waited for the server to be ready would be
coupling the two again by the back door). The bells stop being inherited fds and
are created by the server and handed over with the segments - slots 4 and 5 of
six SCM_RIGHTS offers. And the client connects TWICE to the same path: an fd
offer is a sendmsg whose ancillary data rides with specific bytes, so it may not
share a socket with the framed control stream, or the frame reassembler and the
descriptor receiver race for the same bytes.
The pieces behind it:
- SessionSegments::AdoptFromDescriptors, which is the same Adopt+Map loop
AttachInProcess has run on every inproc session since P5. That was the point
of writing the inproc attach as dup+Adopt+Map rather than as an alias: only
the origin of the descriptor is new.
- ServerSession::SetExternalDoorbells, the narrow fix for a6 row A7-1 - the
§3.9 accessors abort for every role but InProcess, so a spawn apply thread
died before popping its first record. lk deletes them; until then an injected
pair is honest about where the bells come from.
- MG_Backend::InitServerRoleForSpawn: steps 1 and 2 of the split bring-up
extracted so the server process runs the SAME code the inproc server role
runs. The capability bits are a statement about the server's own backend and
a second copy would diverge the first time a backend registers a slot.
- ClientSession::FinishStartup: everything below the attach - producer, reply
pool, event ring, segment table, encoder, first CapsSnapshot, emitter tables -
shared verbatim between inproc and spawn. Its one parameter is not a
transport question: under inproc the client starts the apply thread because
there is no server-side main; under spawn there is one, and it started the
thread before it sent the first descriptor.
G1 CAUGHT A REAL LEAK on the way: InitServerRoleForSpawn was guarded on the
inside, so the pull build still DEFINED the symbol - 2 added, 1 removed, .text
+16 bytes. The whole function and its declaration are now inside the guard.
"It returns false there" is not the same as "it is not there", and the gate is
what said so.
Gates: ServerSpawnTest 4/4; unit suite 2344 with the same two pre-existing
environmental failures; G1 pull 0 added / 0 removed, .text 10822147 unchanged.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
MobileGL
A desktop OpenGL implementation
MobileGL is a free and open-source project that implements a desktop OpenGL API. The goal is to provide a complete desktop OpenGL implementation with a state management layer and multi-backend support.
Note
Status: In development. Parts of the codebase are incomplete. Current short-term target: OpenGL 4.2 (Core Profile).
Project positioning
MobileGL is an implementation of a desktop OpenGL library. It aims to provide:
- Full OpenGL state management.
- A front-end that exposes OpenGL functions.
- Multiple independent backend implementations, where each backend targets a specific graphics API and remains fully isolated from others.
This project is intended as an implementation/translation layer.
Key components
The repository is organized into following top-level modules:
- MG_State — state tracking and management logic for Graphics APIs.
- MG_Impl — front-end implementations of Graphics APIs that interact with
MG_StateandMG_Backend. - MG_Backend — per-backend translation layer that maps front-end Graphics APIs' semantics and state into concrete backend API calls (e.g. OpenGL ES, Vulkan).
- MG_Util and other utility modules.
Third-party components
MobileGL reuses several open-source projects:
- SPIRV-Cross by KhronosGroup - Apache License 2.0: github
- glslang by KhronosGroup - Various Licenses: github
- DiligentCore by Diligent Graphics - Apache License 2.0: github
- flat_hash_map by Malte Skarupke - Boost Software License 1.0: github
Refer to each component's repository for exact license texts. Any bundled third-party code in this repository is included under the upstream project's license.
Compatibility & target
- Short-term target:
OpenGL 4.2 (Core Profile). - Current development focus:
- Performance improvement
MG_StateandMG_ImplforOpenGL 4.2 (Core Profile)Direct (Vulkan)backendDirect (OpenGL ES)backend
Build Instructions
We currently provide no releases and no precompiled binaries.
If you want to try the project right now, you’ll need to build it yourself:
-
Clone the repository:
git clone https://github.com/MobileGL-Dev/MobileGL.git -
Initialize and update all submodules recursively:
git submodule update --init --recursive -
Follow glslang’s own documentation for its required initiation.
-
Configure and build the project with CMake:
cmake -B build cmake --build buildor do it in a modern way:
cmake -S . -B build -G Ninja -DCMAKE_C_COMPILER=clang -DCMAKE_CXX_COMPILER=clang++ cmake --build buildAlternatively, you can use platform-specific build commands as needed.
Build For macOS
On macOS, MobileGL can be built as a dylib that exposes the normal OpenGL/CGL/NSOpenGL entry points and routes them to the DirectVulkan backend. This is useful for running applications such as Minecraft through their stock GLFW/LWJGL OpenGL path while MobileGL is injected before context creation.
Prerequisites:
- macOS with Clang and Ninja.
- Vulkan loader and MoltenVK installed. With Homebrew, the MoltenVK ICD is commonly located at
/opt/homebrew/etc/vulkan/icd.d/MoltenVK_icd.json.
Configure and build:
cmake -S . -B build-macos-magma \
-G Ninja \
-DCMAKE_BUILD_TYPE=Release \
-DMOBILEGL_BACKEND_TYPE=DirectVulkan \
-DMOBILEGL_BUILD_TEST=OFF \
-DMOBILEGL_BUILD_BENCHMARK=OFF
cmake --build build-macos-magma --target MobileGL -j8
The dylib will be generated at:
build-macos-magma/libMobileGL.dylib
To run Minecraft by MobileGL from a launcher like PrismLauncher, keep the stock LWJGL/GLFW natives and add a wrapper command to the instance settings:
env DYLD_INSERT_LIBRARIES=/absolute/path/to/MobileGL/build-macos-magma/libMobileGL.dylib MOBILEGL_BACKEND_TYPE=DirectVulkan VK_ICD_FILENAMES=/opt/homebrew/etc/vulkan/icd.d/MoltenVK_icd.json
Also make sure the JVM arguments include:
-XstartOnFirstThread
DYLD_INSERT_LIBRARIES must be active before GLFW creates its OpenGL context. After startup, the Minecraft F3 screen should report MobileGL and the Direct (Vulkan) backend if the injection worked.
Build Options
| Option | Description | Default |
|---|---|---|
MOBILEGL_BUILD_TEST |
Build MobileGL tests (requires Clang) | ON |
MOBILEGL_BUILD_BENCHMARK |
Build MobileGL benchmarks (requires Clang) | ON |
MOBILEGL_FORCE_RELEASE_OPT |
Enable O3 and LTO in Debug build | ON |
MOBILEGL_ENABLE_TRACY |
Enable Tracy profiler for performance analysis | OFF |
Notes:
- The project requires C++23.
MG_TestandMG_Benchmarkcan only be built with Clang, not GCC. To enforce Clang, add-DCMAKE_C_COMPILER=clang -DCMAKE_CXX_COMPILER=clang++to your command.- On Android, tests and benchmarks are always disabled.
Environment Variables
MobileGL supports runtime configuration via environment variables.
Supported Keys
| Variable | Description | Allowed Values | Default |
|---|---|---|---|
MOBILEGL_BACKEND_TYPE |
Select active backend implementation at startup. | DirectGLES, DirectVulkan |
DirectGLES |
MOBILEGL_DISABLE_TIMERQUERY |
Disable GPU timer-query exposure and use. | 0, 1 |
0 |
MOBILEGL_ESPRYT_USE_ANGLE |
Load ANGLE EGL/GLES libraries. | 0, 1 |
0 |
MOBILEGL_MAGMA_DISABLE_SUBGROUP |
Disable Vulkan shader subgroup support. | 0, 1 |
0 |
MOBILEGL_ADVERTISE_FP64 |
Advertise GL_ARB_gpu_shader_fp64. GLSL double/dvec/dmat compile and run either way - they are narrowed to 32 bits - so this only changes whether an application is told it has 64-bit precision, which it does not. |
0, 1 |
0 |
MOBILEGL_MAGMA_R11G11B10F_FALLBACK |
Use Magma's R11G11B10F format fallback. | 0, 1 |
0 |
MOBILEGL_MAGMA_FRAMESINFLIGHT |
Set Magma frames in flight. | Integer 1–64 |
3 |
MOBILEGL_ESPRYT_AVOID_SAMPLER_MIPMAP_MIN_FILTER |
Avoid sampler mipmap minification filters. | 0, 1 |
0 |
MOBILEGL_COHERENT_AS_FLUSH |
Treat persistent GL_MAP_FLUSH_EXPLICIT_BIT maps as coherent (app-compat for engines like Flywheel that never flush them). |
0, 1 |
0 |
MOBILEGL_ESPRYT_FORCE_DS_READBACK_EMULATION |
Always emulate depth/stencil glReadPixels/glGetTexImage by shader sampling on Espryt, instead of using the driver's own depth/stencil readback where it has one. |
0, 1 |
0 |
VK_ICD_FILENAMES |
Select the Vulkan ICD used by the Vulkan loader. | Path to an ICD JSON file | Loader default |
License
This project is distributed under GNU LGPL v3.0. See the LICENSE file in the repository for detailed information.