[Fix] (DirectVulkan): harden the leak-fix round after adversarial review - pipeline memo now drops at every command-buffer boundary (a flush-loop-memoized pipeline could age out and be destroyed while its submission was in flight), mid-frame drains no longer rewind the arena or advance the cache-aging clocks in presenting apps (gated to every 8th drain since the last Present, so readback/fence-heavy frames neither churn conversions nor shrink the 1024-boundary retire window), render-pass eviction notifies the pipeline cache once per sweep batch instead of once per dying pass, descriptor pools use FREE_DESCRIPTOR_SET_BIT so a destroyed layout's cached sets are freed back and credited instead of abandoning pool slots (the live-layout age sweep that could orphan slots is removed - layout destruction is the sole purge path), and renderbuffer respecify parks the old backing for aged destruction instead of destroying it while possibly in flight

MobileGL/MG_Backend/DirectVulkan/Renderer/UniformManager.h

@@ -41,16 +41,15 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         void BeginFrame(Uint32 frameIndex);
         // A ProgramFactory eviction just destroyed this layout: purge every frame
         // slot's cached descriptor sets for it, so a recycled handle value can never
-        // stale-hit sets written for the dead layout's bindings. The sets themselves
-        // are only dropped, never freed - the frame pools are created without
-        // FREE_DESCRIPTOR_SET_BIT and are never reset mid-life, so their pool slots
-        // stay occupied until Shutdown destroys the pools wholesale.
+        // stale-hit sets written for the dead layout's bindings. The sets are
+        // vkFreeDescriptorSets'd back to their pools (created with
+        // FREE_DESCRIPTOR_SET_BIT) and the pool accounting is credited, so program
+        // churn recycles pool capacity instead of abandoning it. GPU-safe: the layout
+        // only dies after >1024 idle frame boundaries, so no in-flight command buffer
+        // references its sets. This is the only eviction path for the per-layout
+        // caches - a live layout's entry must never be purged (its sets would be
+        // unreachable pool slots), so there is deliberately no age-based sweep here.
         void OnDescriptorSetLayoutDestroyed(VkDescriptorSetLayout descriptorSetLayout);
-        // Frame boundary hook: ages the per-layout descriptor-set caches and drops
-        // long-unused entries (mirroring VkRenderPassManager::OnPresent's sweep), so a
-        // shader-churn session's peak layout population does not pin its tracking
-        // vectors forever. Same pool-slot caveat as above.
-        void OnFrameBoundary();
         Bool CollectSampledTextures(const MG_State::GLState::ProgramObject& program,
                                     const ProgramFactory::VkProgramObject& programObj,
                                     Vector<MG_State::GLState::ITextureObject*>& outTextures);
@@ -77,12 +76,17 @@ namespace MobileGL::MG_Backend::DirectVulkan {
             Uint32 allocatedSets = 0;
         };
 
+        // A cached descriptor set together with the pool it was allocated from, so a
+        // layout-destroyed purge can vkFreeDescriptorSets it back and credit the
+        // owning bucket's accounting.
+        struct CachedDescriptorSet {
+            VkDescriptorSet set = VK_NULL_HANDLE;
+            VkDescriptorPool pool = VK_NULL_HANDLE;
+        };
+
         struct DescriptorSetCacheEntry {
-            Vector<VkDescriptorSet> sets;
+            Vector<CachedDescriptorSet> sets;
             Uint32 cursor = 0;
-            // Frame-boundary counter value of the last AcquireDescriptorSet hit; drives
-            // cache eviction (see OnFrameBoundary).
-            Uint64 lastUsedFrame = 0;
         };
 
         struct FrameResources {
@@ -146,9 +150,6 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         Vector<FrameResources> m_frames;
 
         VkDeviceSize m_minDynamicOffsetAlignment = 1;
-        // Monotonic frame-boundary counter (bumped in OnFrameBoundary) for
-        // descriptor-set cache aging.
-        Uint64 m_frameCounter = 0;
         Uint32 m_frameCount = 0;
         Uint32 m_maxBindings = 0;
         Uint32 m_setsPerFrame = 0;