swung0x48/MobileGL
1
0
Fork 0
mirror of https://github.com/MobileGL-Dev/MobileGL synced 2026-09-12 14:18:31 +09:00
Code Issues Packages Projects Releases Wiki Activity

[Refactor] (MG_State, MG_Backend): PipeResource storage layer + zero-copy coherent persistent maps

Browse Source 
Introduce a Mesa pipe_resource-style PipeResource that owns a GL buffer's bytes
and its backend GPU resource, abstracting WHERE the authoritative bytes live:
 - Shadow mode (non-persistent buffers): a CPU Vector; the backend keeps its own
   GPU copy in sync via BufferBackendOps, exactly as before.
 - Persistent mode (coherent GL_MAP_PERSISTENT maps): the backend's host-visible,
   COHERENT, persistently-mapped GPU memory is the single source of truth. The app
   writes into it directly, every reader resolves against it, and NO per-write
   backend transfer happens. The CPU shadow is released.

BufferObject no longer owns a raw shadow Vector; it holds a PipeResource and
exposes one accessor, MappedData(), that all readers go through. Every buffer-data
consumer (UBO payload, PBO texture upload, indirect draws, resident/streamed
uploads, both backends) was migrated from GetDataReadOnly()->data() to
MappedData(), so a persistent buffer's readers see GPU memory - not a stale
shadow. That stale-shadow inconsistency is what corrupted rendering (wrong UBOs ->
misplaced/"lost" vertices) in the first zero-copy attempt (625c8a6, reverted in
896cafc); routing every consumer through one accessor makes it structurally
impossible.

Backends provide the map via BufferBackendOps::AcquirePersistentMap:
 - DirectVulkan: a HOST_VISIBLE|HOST_COHERENT (required, not just requested),
   persistently mapped resident VkBuffer carrying every usage, seeded from the
   shadow, never recreated; AcquireResidentSlice binds it directly.
 - DirectGLES: EXT_buffer_storage immutable persistent+coherent glMapBufferRange,
   falling back to the shadow when the extension is absent.

Fixes the ~7GB GpuMemory OOM + 100%-CPU/ANR running modern Blaze3D Minecraft on
both Magma and Espryt (per-draw whole-buffer re-upload of the coherent persistent
ring buffer), without the coherency/stale-read hazards of the reverted attempt.

BufferTest: zero-copy stress guard (15,360 draws -> 0 per-draw transfers, and every
reader resolves to GPU memory) + a shadow-fallback test. Host suite: 203/203 pass.
Device verification pending.
This commit is contained in:
swung0x48
2026-07-11 20:18:38 -04:00
parent 0f99d93300
commit c1743aa42d
15 changed files with 577 additions and 101 deletions
Download Patch File Download Diff File Expand all files Collapse all files
MobileGL/MG_Backend/DirectVulkan/Renderer/VkBufferObject.h
+5 -1
View File
@@ -20,6 +20,9 @@ namespace MobileGL::MG_Backend::DirectVulkan {
VkBufferUsageFlags usage = 0;
VmaMemoryUsage memoryUsage = VMA_MEMORY_USAGE_AUTO;
VmaAllocationCreateFlags allocationFlags = 0;
// Memory property bits the allocation MUST satisfy (e.g. HOST_VISIBLE|HOST_COHERENT
// for a persistently-mapped buffer the app writes into without explicit flushes).
VkMemoryPropertyFlags requiredFlags = 0;
};
class VkBufferObject {
@@ -34,7 +37,8 @@ namespace MobileGL::MG_Backend::DirectVulkan {
Bool Create(const VkBufferObjectDesc& desc);
Bool Create(VmaAllocator allocator, VkDeviceSize size, VkBufferUsageFlags usage,
VmaMemoryUsage memoryUsage, VmaAllocationCreateFlags allocationFlags = 0);
VmaMemoryUsage memoryUsage, VmaAllocationCreateFlags allocationFlags = 0,
VkMemoryPropertyFlags requiredFlags = 0);
void Destroy();
void* Map();