[Fix] (DirectVulkan): age-based eviction for the content-addressed cache family - ProgramFactory entries (shader modules/layouts), PipelineFactory graphics pipelines, compute pipelines and per-layout descriptor-set tracking now retire after ~1024 idle frame boundaries (render-pass-manager sweep precedent), render-pass eviction purges pipelines hashed on the dying handle (closes a handle-recycling stale-pipeline hazard), and the program reflection cache is lifetime-id-keyed and cleared at EGL teardown - shader/program churn no longer grows Vulkan objects without bound

MobileGL/MG_Backend/DirectVulkan/BackendObject_DirectVulkan.cpp

@@ -469,6 +469,9 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         // treat them as signaled/available with zero results from here on.
         BumpRendererGeneration();
         pVulkanRenderer.reset();
+        // The reflection cache is file-scope, not renderer-owned; without this the
+        // deleted programs' reflection strings survive full context teardown.
+        ClearProgramResourceCaches();
         BackendObject::ReleaseEGLResources();
     }
 
@@ -478,6 +481,9 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         // treat them as signaled/available with zero results from here on.
         BumpRendererGeneration();
         pVulkanRenderer.reset();
+        // The reflection cache is file-scope, not renderer-owned; without this the
+        // deleted programs' reflection strings survive full context teardown.
+        ClearProgramResourceCaches();
     }
 
     const RendererInfo& BackendObject_DirectVulkan::GetRendererInfo() const {

MobileGL/MG_Backend/DirectVulkan/DirectVulkan.cpp

@@ -61,6 +61,12 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         };
 
         struct ProgramResourceCache {
+            // Lifetime id of the program the cached reflection belongs to. GL names are
+            // recycled (IndexGenerator hands freed indices straight back), and a
+            // recreated program's backendStateVersion restarts at the same small values,
+            // so the version alone can collide; the never-reused lifetime id makes the
+            // slot's ownership unambiguous.
+            Uint64 programLifetimeId = 0;
             Uint32 backendStateVersion = 0;
             Vector<StorageBlockResource> storageBlocks;
             Vector<BufferVariableResource> bufferVariables;
@@ -82,6 +88,11 @@ namespace MobileGL::MG_Backend::DirectVulkan {
             Uint32 baseInstance = 0;
         };
 
+        // Keyed by GL program name so the freed-name reuse in IndexGenerator bounds the
+        // map at the peak-simultaneous-program high-water mark; each slot's ownership is
+        // checked against the program's lifetime id before it is served (see
+        // GetProgramResourceCache). Cleared wholesale at EGL teardown via
+        // ClearProgramResourceCaches.
         UnorderedMap<GLuint, ProgramResourceCache> g_programResourceCaches;
 
         void ClearReadPixelsOutput(GLsizei width, GLsizei height, GLenum format, GLenum type, void* pixels) {
@@ -142,13 +153,19 @@ namespace MobileGL::MG_Backend::DirectVulkan {
 
         ProgramResourceCache& GetProgramResourceCache(const MG_State::GLState::ProgramObject& program) {
             auto& cache = g_programResourceCaches[program.GetExternalIndex()];
+            const Uint64 programLifetimeId = program.GetLifetimeId();
             const Uint32 backendStateVersion = program.GetBackendStateVersion();
-            if (cache.backendStateVersion == backendStateVersion &&
+            // The lifetime id must match too: a new program that reuses a deleted
+            // program's name and happens to land on the same backendStateVersion (both
+            // count from zero) would otherwise be served the dead program's reflection.
+            if (cache.programLifetimeId == programLifetimeId &&
+                cache.backendStateVersion == backendStateVersion &&
                 (!cache.storageBlocks.empty() || !cache.bufferVariables.empty())) {
                 return cache;
             }
 
             cache = {};
+            cache.programLifetimeId = programLifetimeId;
             cache.backendStateVersion = backendStateVersion;
 
             Vector<SpvReflectShaderModule> modules;
@@ -366,6 +383,15 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         }
     } // namespace
 
+    void ClearProgramResourceCaches() {
+        // Called from EGL teardown while the backend's m_eglStateMutex is held; GL
+        // calls are serialized in this codebase (contexts migrate threads but never
+        // run concurrently), so no other thread can be inside the unsynchronized map.
+        // Live programs in another context self-heal: their entry rebuilds from the
+        // retained generated SPIR-V on the next resource query.
+        g_programResourceCaches.clear();
+    }
+
     GLuint GetShaderStorageBlockIndex(const MG_State::GLState::ProgramObject& program, const String& name) {
         auto& cache = GetProgramResourceCache(program);
         const auto it = std::find_if(cache.storageBlocks.begin(), cache.storageBlocks.end(),

MobileGL/MG_Backend/DirectVulkan/DirectVulkan.h

@@ -23,6 +23,12 @@ namespace MobileGL::MG_Backend::DirectVulkan {
     Uint64 GetRendererGeneration();
     void BumpRendererGeneration();
 
+    // Drops every cached program-resource reflection entry (CPU-side strings/vectors
+    // only, no Vulkan handles). Called at EGL teardown next to the renderer reset;
+    // safe because GL calls are serialized in this codebase, and any still-live
+    // program rebuilds its entry from the retained generated SPIR-V on demand.
+    void ClearProgramResourceCaches();
+
     void ClearBufferfi(GLenum buffer, GLint drawbuffer, GLfloat depth, GLint stencil);
     void ClearBufferfv(GLenum buffer, GLint drawbuffer, const GLfloat* value);
     void ClearBufferuiv(GLenum buffer, GLint drawbuffer, const GLuint* value);

MobileGL/MG_Backend/DirectVulkan/Renderer/PipelineFactory.cpp

@@ -243,23 +243,100 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         const HashType hash = ComputeHash(payload);
         auto it = m_cache.find(hash);
         if (it != m_cache.end()) {
-            return it->second;
+            it->second.lastUsedFrame = m_frameCounter;
+            return it->second.pipeline;
         }
 
         VkPipeline pipeline = CreatePipeline(payload);
-        m_cache.emplace(hash, pipeline);
+        m_cache.emplace(hash, PipelineCacheEntry{pipeline, payload.programHash, payload.renderPass,
+                                                 m_frameCounter});
         return pipeline;
     }
 
     void PipelineFactory::DestroyAll() {
         for (auto& pair : m_cache) {
-            if (pair.second != VK_NULL_HANDLE) {
+            if (pair.second.pipeline != VK_NULL_HANDLE) {
-                vkDestroyPipeline(m_device, pair.second, nullptr);
+                vkDestroyPipeline(m_device, pair.second.pipeline, nullptr);
             }
         }
         m_cache.clear();
     }
 
+    Uint32 PipelineFactory::OnFrameBoundary() {
+        ++m_frameCounter;
+
+        // Sweep cadence and retire age mirror VkRenderPassManager::OnPresent: an entry
+        // idle for more than kRetireAgeFrames frame boundaries cannot be referenced by
+        // any in-flight command buffer (frames-in-flight <= MOBILEGL_MAGMA_FRAMESINFLIGHT),
+        // so immediate vkDestroyPipeline is safe. The caller must drop its "last
+        // pipeline" memo when this returns non-zero: the memo can return a cached
+        // handle without touching this cache, so an evicted pipeline may still be
+        // memoized (present-less flush loops never reset the memo per frame).
+        constexpr Uint64 kSweepInterval = 256;
+        constexpr Uint64 kRetireAgeFrames = 1024;
+        if ((m_frameCounter % kSweepInterval) != 0) {
+            return 0;
+        }
+
+        Uint32 evicted = 0;
+        for (auto it = m_cache.begin(); it != m_cache.end();) {
+            if (m_frameCounter - it->second.lastUsedFrame > kRetireAgeFrames) {
+                if (it->second.pipeline != VK_NULL_HANDLE) {
+                    vkDestroyPipeline(m_device, it->second.pipeline, nullptr);
+                }
+                it = m_cache.erase(it);
+                ++evicted;
+            } else {
+                ++it;
+            }
+        }
+        if (evicted > 0) {
+            MGLOG_D("PipelineFactory::OnFrameBoundary: evicted %u idle pipelines (%zu remain)", evicted,
+                    m_cache.size());
+        }
+        return evicted;
+    }
+
+    Uint32 PipelineFactory::EvictByRenderPass(VkRenderPass renderPass) {
+        Uint32 evicted = 0;
+        for (auto it = m_cache.begin(); it != m_cache.end();) {
+            if (it->second.renderPass == renderPass) {
+                if (it->second.pipeline != VK_NULL_HANDLE) {
+                    vkDestroyPipeline(m_device, it->second.pipeline, nullptr);
+                }
+                it = m_cache.erase(it);
+                ++evicted;
+            } else {
+                ++it;
+            }
+        }
+        if (evicted > 0) {
+            MGLOG_D("PipelineFactory::EvictByRenderPass: evicted %u pipelines for destroyed render pass",
+                    evicted);
+        }
+        return evicted;
+    }
+
+    Uint32 PipelineFactory::EvictByProgramHash(HashType programHash) {
+        Uint32 evicted = 0;
+        for (auto it = m_cache.begin(); it != m_cache.end();) {
+            if (it->second.programHash == programHash) {
+                if (it->second.pipeline != VK_NULL_HANDLE) {
+                    vkDestroyPipeline(m_device, it->second.pipeline, nullptr);
+                }
+                it = m_cache.erase(it);
+                ++evicted;
+            } else {
+                ++it;
+            }
+        }
+        if (evicted > 0) {
+            MGLOG_D("PipelineFactory::EvictByProgramHash: evicted %u pipelines for program hash 0x%llx",
+                    evicted, static_cast<unsigned long long>(programHash));
+        }
+        return evicted;
+    }
+
     VkPipeline PipelineFactory::CreatePipeline(const PipelineCreatePayload& payload) const {
         MOBILEGL_ASSERT(payload.stages != nullptr && !payload.stages->empty(), "PipelineFactory: stages are empty");
         MOBILEGL_ASSERT(payload.vertexInputState != nullptr, "PipelineFactory: vertexInputState is null");

MobileGL/MG_Backend/DirectVulkan/Renderer/PipelineFactory.h

@@ -65,6 +65,26 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         VkPipeline GetOrCreatePipeline(const PipelineCreatePayload& payload);
         void DestroyAll();
 
+        // Frame boundary hook: ages the pipeline cache and destroys long-unused entries
+        // (their command buffers retired many frames ago), mirroring
+        // VkRenderPassManager::OnPresent's sweep. Returns the number of pipelines
+        // destroyed so the caller can drop any memoized VkPipeline handle.
+        Uint32 OnFrameBoundary();
+        // Destroys every cached pipeline hashed on `renderPass`. Only safe when the
+        // caller guarantees GPU idleness for them - the render-pass manager calls this
+        // (via the renderer) for passes its own >1024-boundary-idle sweep just evicted,
+        // and a pipeline hashed on that handle is only ever bound by draws that also
+        // hit the render-pass entry. Also closes the handle-recycling hazard: a
+        // recycled VkRenderPass value must never serve a stale pipeline. Returns the
+        // number destroyed (callers invalidate memos when non-zero); linear scan is
+        // fine, evictions are rare.
+        Uint32 EvictByRenderPass(VkRenderPass renderPass);
+        // Destroys every cached pipeline built from the program with content hash
+        // `programHash`. Called from the ProgramFactory eviction path, which proves the
+        // same >1024-boundary idleness (the program's pipelines are only bound by draws
+        // that stamp its factory entry). Returns the number destroyed.
+        Uint32 EvictByProgramHash(HashType programHash);
+
         // Driver quirk: suppress depth writes on accumulation-blended pipelines. Multi-pass
         // depth-equality rendering (a blended prepass writes depth that later passes re-test
         // with an equality-inclusive compare on the re-rasterized geometry) requires
@@ -87,12 +107,26 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         static Bool ShouldSuppressDepthWrite(const PipelineCreatePayload& payload);
 
     private:
+        struct PipelineCacheEntry {
+            VkPipeline pipeline = VK_NULL_HANDLE;
+            // The hashed inputs the eviction paths key on: programHash ties the entry to
+            // its ProgramFactory entry, renderPass records the exact handle the hash
+            // folded in (the hash is one-way, so targeted eviction needs them verbatim).
+            HashType programHash = 0;
+            VkRenderPass renderPass = VK_NULL_HANDLE;
+            // Frame-boundary counter value of the last GetOrCreatePipeline hit; drives
+            // cache eviction (see OnFrameBoundary).
+            Uint64 lastUsedFrame = 0;
+        };
+
         VkPipeline CreatePipeline(const PipelineCreatePayload& payload) const;
 
         VkDevice m_device = VK_NULL_HANDLE;
         const VulkanRendererConfig& m_config;
         VkPipelineCache m_pipelineCache = VK_NULL_HANDLE;
-        UnorderedMap<HashType, VkPipeline> m_cache;
+        UnorderedMap<HashType, PipelineCacheEntry> m_cache;
+        // Monotonic frame-boundary counter (bumped in OnFrameBoundary) for cache aging.
+        Uint64 m_frameCounter = 0;
         static inline XXH64_state_t* m_hashState = XXH64_createState();
         static inline Bool s_suppressBlendedDepthWrite = false;
     };

MobileGL/MG_Backend/DirectVulkan/Renderer/ProgramFactory.cpp

@@ -1950,11 +1950,17 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         }
         auto it = m_cache.find(hash);
         if (it != m_cache.end()) {
+            // Every draw/dispatch funnels through this lookup (the renderer memos only
+            // skip re-hashing, never the factory lookup), so an actively-used entry is
+            // stamped at least once per frame boundary and can never be aged out while
+            // any in-flight command buffer still references it.
+            it->second.lastUsedFrame = m_frameCounter;
             return it->second;
         }
 
         auto& entry = m_cache[hash];
         entry.hash = hash;
+        entry.lastUsedFrame = m_frameCounter;
         auto& shaders = program.GetAttachedShaders();
         auto& spirv = program.GetGeneratedSpirv();
         Vector<Vector<Uint>> moduleSpirvs(spirv.size());
@@ -2068,4 +2074,42 @@ namespace MobileGL::MG_Backend::DirectVulkan {
 
         return entry;
     }
+
+    void ProgramFactory::OnFrameBoundary() {
+        ++m_frameCounter;
+
+        // Sweep cadence and retire age mirror VkRenderPassManager::OnPresent: an entry
+        // idle for more than kRetireAgeFrames frame boundaries cannot be referenced by
+        // any in-flight command buffer (frames-in-flight <= MOBILEGL_MAGMA_FRAMESINFLIGHT),
+        // so its shader modules and layouts are destroyed immediately - no deferred-
+        // destroy machinery needed. Eviction is content-based, never tied to
+        // glDeleteProgram: the cache is content-hash-shared across GL programs, so a
+        // delete-driven erase could free an entry another live program still resolves.
+        // An evicted entry self-heals - the frontend program keeps its generated
+        // SPIR-V, so the next GetOrCreateProgram rebuilds it (this also covers the
+        // renderer's internal blit/depth-mipmap programs).
+        constexpr Uint64 kSweepInterval = 256;
+        constexpr Uint64 kRetireAgeFrames = 1024;
+        if ((m_frameCounter % kSweepInterval) != 0) {
+            return;
+        }
+
+        for (auto it = m_cache.begin(); it != m_cache.end();) {
+            if (m_frameCounter - it->second.lastUsedFrame > kRetireAgeFrames) {
+                const HashType hash = it->first;
+                const VkDescriptorSetLayout descriptorSetLayout = it->second.descriptorSetLayout;
+                MGLOG_D("ProgramFactory::OnFrameBoundary: evicting idle program entry hash=0x%llx",
+                        static_cast<unsigned long long>(hash));
+                // erase runs ~VkProgramObject (modules/layouts destroyed); notify after
+                // so an observer never observes a half-destroyed entry through a lookup.
+                // Observers only need the handle values to purge their keyed caches.
+                it = m_cache.erase(it);
+                if (m_evictionObserver != nullptr) {
+                    m_evictionObserver->OnProgramEvicted(hash, descriptorSetLayout);
+                }
+            } else {
+                ++it;
+            }
+        }
+    }
 } // namespace MobileGL::MG_Backend::DirectVulkan

MobileGL/MG_Backend/DirectVulkan/Renderer/ProgramFactory.h

@@ -88,6 +88,9 @@ namespace MobileGL::MG_Backend::DirectVulkan {
             // gl_FragDepth); shader-computed depth is immune to the cross-pipeline
             // position-invariance quirk (see PipelineFactory::ShouldSuppressDepthWrite).
             Bool fragmentReplacesDepth = false;
+            // Frame-boundary counter value of the last GetOrCreateProgram hit; drives
+            // cache eviction (see OnFrameBoundary).
+            Uint64 lastUsedFrame = 0;
 
             static inline VkDevice s_device = VK_NULL_HANDLE;
 
@@ -124,6 +127,7 @@ namespace MobileGL::MG_Backend::DirectVulkan {
                 producerOutputComponentCount = other.producerOutputComponentCount;
                 fragmentInputComponentCount = other.fragmentInputComponentCount;
                 fragmentReplacesDepth = other.fragmentReplacesDepth;
+                lastUsedFrame = other.lastUsedFrame;
                 other.hash = 0;
                 other.descriptorSetLayout = VK_NULL_HANDLE;
                 other.pipelineLayout = VK_NULL_HANDLE;
@@ -135,6 +139,7 @@ namespace MobileGL::MG_Backend::DirectVulkan {
                 other.producerOutputComponentCount = 0;
                 other.fragmentInputComponentCount = 0;
                 other.fragmentReplacesDepth = false;
+                other.lastUsedFrame = 0;
             }
             VkProgramObject& operator=(VkProgramObject&& other) noexcept {
                 if (this == &other) {
@@ -170,6 +175,7 @@ namespace MobileGL::MG_Backend::DirectVulkan {
                 producerOutputComponentCount = other.producerOutputComponentCount;
                 fragmentInputComponentCount = other.fragmentInputComponentCount;
                 fragmentReplacesDepth = other.fragmentReplacesDepth;
+                lastUsedFrame = other.lastUsedFrame;
                 other.hash = 0;
                 other.descriptorSetLayout = VK_NULL_HANDLE;
                 other.pipelineLayout = VK_NULL_HANDLE;
@@ -181,6 +187,7 @@ namespace MobileGL::MG_Backend::DirectVulkan {
                 other.producerOutputComponentCount = 0;
                 other.fragmentInputComponentCount = 0;
                 other.fragmentReplacesDepth = false;
+                other.lastUsedFrame = 0;
                 return *this;
             }
 
@@ -210,6 +217,18 @@ namespace MobileGL::MG_Backend::DirectVulkan {
             }
         };
 
+        // Notified when the OnFrameBoundary sweep destroys an aged-out cache entry,
+        // carrying the entry's content hash and the VkDescriptorSetLayout it owned.
+        // Dependent caches (compute pipelines, PipelineFactory entries, UniformManager's
+        // per-layout descriptor sets) must purge in the same step: after vkDestroy the
+        // layout handle value may be recycled for an unrelated layout, and the program
+        // hash may be re-inserted by a later rebuild of the same content.
+        class IEvictionObserver {
+        public:
+            virtual ~IEvictionObserver() = default;
+            virtual void OnProgramEvicted(HashType programHash, VkDescriptorSetLayout descriptorSetLayout) = 0;
+        };
+
         explicit ProgramFactory(VkDevice device, const VulkanRendererConfig& config, Uint32 maxBindings = 16,
                                 Bool shaderDrawParametersEnabled = false,
                                 Bool unformattedFloatStorageImagesEnabled = false)
@@ -225,6 +244,13 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         const VkProgramObject& GetOrCreateProgram(
             const MG_State::GLState::ProgramObject& program, CompileOptionFlags flags);
 
+        // Observer may be null (no notifications). Not owned.
+        void SetEvictionObserver(IEvictionObserver* observer) { m_evictionObserver = observer; }
+        // Frame boundary hook: ages the program cache and evicts long-unused entries
+        // (their command buffers retired many frames ago), mirroring
+        // VkRenderPassManager::OnPresent's sweep.
+        void OnFrameBoundary();
+
         static VkShaderStageFlagBits ToVkStage(ShaderStage stage);
         static VkFormat ConvertSpirvImageFormatToVkFormat(SpvImageFormat format);
         static SamplerNumericDomain UniformTypeToSamplerNumericDomain(GLenum glType);
@@ -266,6 +292,9 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         // shaderStorageImageReadWithoutFormat and shaderStorageImageWriteWithoutFormat.
         Bool m_unformattedFloatStorageImagesEnabled = false;
         mutable ProgramLookupCache m_lastLookup;
+        // Monotonic frame-boundary counter (bumped in OnFrameBoundary) for cache aging.
+        Uint64 m_frameCounter = 0;
+        IEvictionObserver* m_evictionObserver = nullptr;
         static inline XXH64_state_t* m_hashState = XXH64_createState();
     };
 } // namespace MobileGL::MG_Backend::DirectVulkan

MobileGL/MG_Backend/DirectVulkan/Renderer/UniformManager.cpp

@@ -171,6 +171,7 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         m_programFactory = nullptr;
         m_device = VK_NULL_HANDLE;
         m_minDynamicOffsetAlignment = 1;
+        m_frameCounter = 0;
         m_frameCount = 0;
         m_maxBindings = 0;
         m_setsPerFrame = 0;
@@ -211,6 +212,56 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         }
     }
 
+    void UniformManager::OnDescriptorSetLayoutDestroyed(VkDescriptorSetLayout descriptorSetLayout) {
+        SizeT purgedSets = 0;
+        for (auto& frame : m_frames) {
+            const auto it = frame.descriptorSetCacheByLayout.find(descriptorSetLayout);
+            if (it != frame.descriptorSetCacheByLayout.end()) {
+                purgedSets += it->second.sets.size();
+                frame.descriptorSetCacheByLayout.erase(it);
+            }
+        }
+        if (purgedSets > 0) {
+            // The per-draw reuse memo folds the layout handle into its signature; drop
+            // it so a recycled handle value cannot revive a purged set mid-frame.
+            m_hasLastDescriptor = false;
+            MGLOG_D("UniformDescriptorBinder: purged %zu descriptor sets for destroyed layout", purgedSets);
+        }
+    }
+
+    void UniformManager::OnFrameBoundary() {
+        ++m_frameCounter;
+
+        // Sweep cadence and retire age mirror VkRenderPassManager::OnPresent. Only the
+        // CPU-side tracking is reclaimed here: the sets' pool slots stay occupied until
+        // Shutdown destroys the pools (no FREE_DESCRIPTOR_SET_BIT, no mid-life pool
+        // reset), exactly as they would had the entry been kept. What the sweep buys is
+        // that an idle layout's tracking vectors stop accumulating, and that a
+        // destroyed-then-recycled layout handle finds no stale entry to hit.
+        constexpr Uint64 kSweepInterval = 256;
+        constexpr Uint64 kRetireAgeFrames = 1024;
+        if ((m_frameCounter % kSweepInterval) != 0) {
+            return;
+        }
+
+        SizeT purgedSets = 0;
+        for (auto& frame : m_frames) {
+            for (auto it = frame.descriptorSetCacheByLayout.begin();
+                 it != frame.descriptorSetCacheByLayout.end();) {
+                if (m_frameCounter - it->second.lastUsedFrame > kRetireAgeFrames) {
+                    purgedSets += it->second.sets.size();
+                    it = frame.descriptorSetCacheByLayout.erase(it);
+                } else {
+                    ++it;
+                }
+            }
+        }
+        if (purgedSets > 0) {
+            m_hasLastDescriptor = false;
+            MGLOG_D("UniformDescriptorBinder::OnFrameBoundary: dropped %zu idle descriptor sets", purgedSets);
+        }
+    }
+
     Bool UniformManager::ResolveSamplerDescriptor(VkCommandBuffer commandBuffer,
                                                             const MG_State::GLState::ProgramObject& program,
                                                             const ProgramFactory::VkProgramObject& programObj,
@@ -989,6 +1040,10 @@ namespace MobileGL::MG_Backend::DirectVulkan {
                                                   VkDescriptorSet& outDescriptorSet) {
         auto& frame = m_frames[frameIndex];
         auto& cache = frame.descriptorSetCacheByLayout[programObj.descriptorSetLayout];
+        // Every layout used in a frame is acquired at least once (the per-draw
+        // descriptor-reuse memo starts each frame invalidated and folds the layout
+        // into its signature), so an actively-used entry is stamped every frame.
+        cache.lastUsedFrame = m_frameCounter;
         if (cache.cursor < cache.sets.size()) {
             outDescriptorSet = cache.sets[cache.cursor++];
         } else {

MobileGL/MG_Backend/DirectVulkan/Renderer/UniformManager.h

@@ -39,6 +39,18 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         void Shutdown();
 
         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.
+        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);
@@ -68,6 +80,9 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         struct DescriptorSetCacheEntry {
             Vector<VkDescriptorSet> sets;
             Uint32 cursor = 0;
+            // Frame-boundary counter value of the last AcquireDescriptorSet hit; drives
+            // cache eviction (see OnFrameBoundary).
+            Uint64 lastUsedFrame = 0;
         };
 
         struct FrameResources {
@@ -131,6 +146,9 @@ 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;

MobileGL/MG_Backend/DirectVulkan/Renderer/VkRenderPassManager.cpp

@@ -1194,6 +1194,12 @@ namespace MobileGL::MG_Backend::DirectVulkan {
                 if (m_rpFastValid && m_rpFastRenderPassHash == it->first) {
                     m_rpFastValid = false;
                 }
+                // Notify while the handle is still alive: pipelines hashed on it share
+                // the entry's >kRetireAgeFrames idleness (they are only bound by draws
+                // that hit this entry), so the observer may destroy them immediately.
+                if (m_evictionObserver != nullptr) {
+                    m_evictionObserver->OnRenderPassDestroyed(it->second.renderPass);
+                }
                 it = m_renderPasses.erase(it);
             } else {
                 ++it;

MobileGL/MG_Backend/DirectVulkan/Renderer/VkRenderPassManager.h

@@ -157,11 +157,27 @@ namespace MobileGL::MG_Backend::DirectVulkan {
     class VkRenderPassManager {
     public:
         using HashType = Uint64;
+
+        // Notified from the OnPresent sweep for each aged-out entry, BEFORE the entry
+        // destructor destroys its VkRenderPass: pipelines are hashed on the raw handle,
+        // and once destroyed the value may be recycled for an incompatible pass, so
+        // dependent caches must purge everything keyed on it in the same step. The
+        // wholesale paths (Shutdown/RecreateSwapchain) do not notify - their callers
+        // already drop every pipeline outright.
+        class IEvictionObserver {
+        public:
+            virtual ~IEvictionObserver() = default;
+            virtual void OnRenderPassDestroyed(VkRenderPass renderPass) = 0;
+        };
+
         VkRenderPassManager(VkDevice device,
             VkPhysicalDevice physicalDevice, VmaAllocator allocator, const VulkanRendererConfig& config,
             VkClearManager& clearManager, VkTextureManager& textureManager, SwapchainObject& swapchainObject);
         ~VkRenderPassManager();
 
+        // Observer may be null (no notifications). Not owned.
+        void SetEvictionObserver(IEvictionObserver* observer) { m_evictionObserver = observer; }
+
         Bool Initialize();
         void Shutdown();
 
@@ -192,6 +208,7 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         UnorderedMap<Uint64, RenderPassEntry> m_renderPasses;
         // Monotonic frame counter (bumped in OnPresent) for render-pass cache aging.
         Uint64 m_frameCounter = 0;
+        IEvictionObserver* m_evictionObserver = nullptr;
 
         // Bumped whenever a renderbuffer VkImage is (re)created; together with the texture
         // manager's image epoch this invalidates the render-pass fast path on any attachment

MobileGL/MG_Backend/DirectVulkan/Renderer/VulkanRenderer.cpp

@@ -2529,6 +2529,11 @@ void main() {
                                                       m_shaderDrawParametersFeatureEnabled,
                                                       m_unformattedFloatStorageImagesEnabled);
         MOBILEGL_ASSERT(m_programFactory != nullptr, "ProgramFactory creation failed.");
+        // Aging evictions (render passes and program entries) must purge the dependent
+        // pipeline / compute-pipeline / descriptor-set caches in the same step; both
+        // sweeps only run from the frame-boundary seams, long after initialization.
+        m_renderPassManager->SetEvictionObserver(this);
+        m_programFactory->SetEvictionObserver(this);
 
         m_samplerManager = MakeUnique<VkSamplerManager>();
         MOBILEGL_ASSERT(m_samplerManager != nullptr, "VkSamplerManager creation failed.");
@@ -2589,6 +2594,15 @@ void main() {
         DestroyDeferredDepthMipmapCleanup();
         DestroyComputePipelines();
 
+        // No sweep runs during teardown, but the observers point at this renderer
+        // and the factories die at different times below; disconnect them first.
+        if (m_renderPassManager) {
+            m_renderPassManager->SetEvictionObserver(nullptr);
+        }
+        if (m_programFactory) {
+            m_programFactory->SetEvictionObserver(nullptr);
+        }
+
         m_pipelineFactory.reset();
         ShutdownBlitResources();
         ShutdownDepthMipmapResources();
@@ -7241,6 +7255,20 @@ void main() {
         if (m_renderPassManager) {
             m_renderPassManager->OnPresent();
         }
+        // Present-less loops cross frame boundaries here, so the content-addressed
+        // caches age on the same cadence as Present's tail. The pipeline memo can
+        // survive across these boundaries (no per-frame reset on this path), so it
+        // must drop whenever the sweep destroys anything.
+        if (m_programFactory) {
+            m_programFactory->OnFrameBoundary();
+        }
+        if (m_pipelineFactory && m_pipelineFactory->OnFrameBoundary() > 0) {
+            m_lastPipelineValid = false;
+            m_lastPipelineResult = VK_NULL_HANDLE;
+        }
+        if (m_uniformManager) {
+            m_uniformManager->OnFrameBoundary();
+        }
         return true;
     }
 
@@ -7496,6 +7524,16 @@ void main() {
         MOBILEGL_ASSERT(m_imageIndexAcquired < m_swapchainObject.GetImageCount(),
                         "Present, acquired image index out of range");
         m_renderPassManager->OnPresent();
+        // Age the content-addressed caches on the same frame-boundary cadence. Each
+        // keeps its own internal 256-sweep gate, so the per-frame cost is one counter
+        // increment and compare per cache; entries used by this frame's still-
+        // unsubmitted recording were stamped this boundary and can never age out.
+        m_programFactory->OnFrameBoundary();
+        if (m_pipelineFactory->OnFrameBoundary() > 0) {
+            m_lastPipelineValid = false; // an aged-out pipeline may still be memoized
+            m_lastPipelineResult = VK_NULL_HANDLE;
+        }
+        m_uniformManager->OnFrameBoundary();
         auto& frame = m_frameContext.GetCurrent();
         auto* activeRenderPass = VkRenderPassManager::GetActiveRenderPass();
         if (activeRenderPass)
@@ -8528,6 +8566,43 @@ void main() {
         m_computePipelines.clear();
     }
 
+    void VulkanRenderer::OnRenderPassDestroyed(VkRenderPass renderPass) {
+        if (m_pipelineFactory == nullptr) {
+            return;
+        }
+        // The render-pass sweep's >1024-boundary idle guarantee covers these pipelines
+        // too (they are only bound by draws that hit the dying entry), so the factory
+        // destroys them immediately. The memo must drop as well: it can hand out a
+        // cached handle without touching the factory.
+        if (m_pipelineFactory->EvictByRenderPass(renderPass) > 0) {
+            m_lastPipelineValid = false;
+            m_lastPipelineResult = VK_NULL_HANDLE;
+        }
+    }
+
+    void VulkanRenderer::OnProgramEvicted(ProgramFactory::HashType programHash,
+                                          VkDescriptorSetLayout descriptorSetLayout) {
+        // Same >1024-boundary idleness as the program entry: its compute pipeline is
+        // only dispatched, and its graphics pipelines only bound, through paths that
+        // stamp the entry, so immediate destruction is GPU-safe. (The graphics memo
+        // never holds compute pipelines; it only needs invalidating for the factory
+        // eviction below.)
+        const auto computeIt = m_computePipelines.find(programHash);
+        if (computeIt != m_computePipelines.end()) {
+            if (computeIt->second != VK_NULL_HANDLE && m_device != VK_NULL_HANDLE) {
+                vkDestroyPipeline(m_device, computeIt->second, nullptr);
+            }
+            m_computePipelines.erase(computeIt);
+        }
+        if (m_pipelineFactory != nullptr && m_pipelineFactory->EvictByProgramHash(programHash) > 0) {
+            m_lastPipelineValid = false;
+            m_lastPipelineResult = VK_NULL_HANDLE;
+        }
+        if (m_uniformManager != nullptr) {
+            m_uniformManager->OnDescriptorSetLayoutDestroyed(descriptorSetLayout);
+        }
+    }
+
     VkPipeline VulkanRenderer::GetOrCreateComputePipeline(const ProgramFactory::VkProgramObject& programObj) {
         const auto it = m_computePipelines.find(programObj.hash);
         if (it != m_computePipelines.end()) {

MobileGL/MG_Backend/DirectVulkan/Renderer/VulkanRenderer.h

@@ -114,7 +114,10 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         }
     };
 
-    class VulkanRenderer : public IBufferCopyCommandProvider, public FrameContext::IRecordingObserver {
+    class VulkanRenderer : public IBufferCopyCommandProvider,
+                           public FrameContext::IRecordingObserver,
+                           public VkRenderPassManager::IEvictionObserver,
+                           public ProgramFactory::IEvictionObserver {
     public:
         VulkanRenderer(NativeWindowType window, const VulkanRendererConfig& cfg = {});
         ~VulkanRenderer();
@@ -131,6 +134,20 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         // recording, before any render pass.
         void OnFrameCommandRecordingBegan(VkCommandBuffer commandBuffer) override;
 
+        // VkRenderPassManager::IEvictionObserver: the render-pass aging sweep is
+        // destroying a VkRenderPass; evict every graphics pipeline hashed on the
+        // dying handle (they share its >1024-boundary idleness, so immediate
+        // destruction is safe) and drop the last-pipeline memo if any went.
+        void OnRenderPassDestroyed(VkRenderPass renderPass) override;
+
+        // ProgramFactory::IEvictionObserver: an aged-out program entry was
+        // destroyed; evict its compute pipeline and graphics pipelines (same
+        // idleness guarantee - they are only bound through draws/dispatches that
+        // stamp the program entry) and purge the descriptor-set cache entries
+        // keyed by its now-recyclable VkDescriptorSetLayout handle.
+        void OnProgramEvicted(ProgramFactory::HashType programHash,
+                              VkDescriptorSetLayout descriptorSetLayout) override;
+
         Bool SetupDraw(FrameContext::FrameData& frame, GLenum mode, Flags<DrawSetupAspect> aspects,
                        const DrawCmdParam& drawParams,
                        const IndexBufferView* pIndexBufferView = nullptr);