[Fix] (MG_Backend/DirectVulkan): render-pass cache grew unbounded; age entries per present and evict after 1024 unused frames

MobileGL/MG_Backend/DirectVulkan/Renderer/VkRenderPassManager.cpp

@@ -602,6 +602,7 @@ namespace MobileGL::MG_Backend::DirectVulkan {
             m_rpFastRenderPassHash == activeRenderPass->hash && !hasPendingClearOnFramebuffer()) {
             auto activeIt = m_renderPasses.find(activeRenderPass->hash);
             if (activeIt != m_renderPasses.end()) {
+                activeIt->second.lastUsedFrame = m_frameCounter;
                 return activeIt->second;
             }
         }
@@ -623,12 +624,15 @@ namespace MobileGL::MG_Backend::DirectVulkan {
             m_rpFastTexEpoch = m_textureManager.GetTextureImageEpoch();
             m_rpFastRbEpoch = m_renderbufferImageEpoch;
             m_rpFastRenderPassHash = activeRenderPass->hash;
+            activeIt->second.lastUsedFrame = m_frameCounter;
             return activeIt->second;
         }
         auto hash = ComputeHash(fbo, swapchainImageIndex, true);
         auto it = m_renderPasses.find(hash);
-        if (it != m_renderPasses.end())
+        if (it != m_renderPasses.end()) {
+            it->second.lastUsedFrame = m_frameCounter;
             return it->second;
+        }
 
         Bool isDefaultFbo = fbo.IsDefaultFramebuffer();
         // Color attachment
@@ -1026,9 +1030,36 @@ namespace MobileGL::MG_Backend::DirectVulkan {
                 extent.x(),
                 extent.y());
         auto [insertedIt, _] = m_renderPasses.emplace(hash, Move(renderPassEntry));
+        insertedIt->second.lastUsedFrame = m_frameCounter;
         return insertedIt->second;
     }
 
+    void VkRenderPassManager::OnPresent() {
+        ++m_frameCounter;
+
+        // Sweep occasionally; evict entries whose last use is far past every
+        // in-flight frame so their VkRenderPass/VkFramebuffer can be destroyed
+        // safely (RenderPassEntry's destructor releases the handles).
+        constexpr Uint64 kSweepInterval = 256;
+        constexpr Uint64 kRetireAgeFrames = 1024;
+        if ((m_frameCounter % kSweepInterval) != 0) {
+            return;
+        }
+
+        const Uint64 activeHash = s_hasActiveRenderPass ? s_activeRenderPass.hash : 0;
+        for (auto it = m_renderPasses.begin(); it != m_renderPasses.end();) {
+            const Bool isActive = s_hasActiveRenderPass && it->first == activeHash;
+            if (!isActive && m_frameCounter - it->second.lastUsedFrame > kRetireAgeFrames) {
+                if (m_rpFastValid && m_rpFastRenderPassHash == it->first) {
+                    m_rpFastValid = false;
+                }
+                it = m_renderPasses.erase(it);
+            } else {
+                ++it;
+            }
+        }
+    }
+
     Bool VkRenderPassManager::BeginRenderPass(VkCommandBuffer commandBuffer, RenderPassEntry& renderPassEntry) {
         // TODO: Transition all the attachments into proper layout before starting the render pass
         VkRenderPassBeginInfo renderPassBeginInfo;

MobileGL/MG_Backend/DirectVulkan/Renderer/VkRenderPassManager.h

@@ -75,6 +75,8 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         IntVec2 extent = {0, 0};
         // VkFramebufferCreateInfo::layers of the entry's framebuffer (>1 for layered GL attachments).
         Uint32 layers = 1;
+        // Frame counter value of the last GetOrCreateRenderPass hit; drives cache eviction.
+        Uint64 lastUsedFrame = 0;
 
         RenderPassEntry() = default;
         RenderPassEntry(const RenderPassEntry&) = delete;
@@ -91,6 +93,7 @@ namespace MobileGL::MG_Backend::DirectVulkan {
             std::swap(sampleCount, that.sampleCount);
             std::swap(extent, that.extent);
             std::swap(layers, that.layers);
+            std::swap(lastUsedFrame, that.lastUsedFrame);
         }
         RenderPassEntry(
             Uint64 hash,
@@ -172,6 +175,9 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         void QueueRenderbufferClear(const ClearAttachmentPayload& clearPayload,
                                     const MG_State::GLState::FramebufferAttachmentObject& attachment);
         void PopPendingRenderbufferClear(MG_State::GLState::RenderbufferObject* renderbuffer);
+        // Frame boundary hook: ages the render-pass cache and evicts long-unused
+        // entries (their command buffers retired many frames ago).
+        void OnPresent();
         static Bool BeginRenderPass(VkCommandBuffer commandBuffer, RenderPassEntry& renderPassEntry);
         static Bool EndRenderPass(VkCommandBuffer commandBuffer);
         static ActiveRenderPassInfo* GetActiveRenderPass();
@@ -184,6 +190,8 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         VkTextureManager& m_textureManager;
         SwapchainObject& m_swapchainObject;
         UnorderedMap<Uint64, RenderPassEntry> m_renderPasses;
+        // Monotonic frame counter (bumped in OnPresent) for render-pass cache aging.
+        Uint64 m_frameCounter = 0;
 
         // 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

@@ -6268,6 +6268,7 @@ void main() {
     void VulkanRenderer::Present() {
         MOBILEGL_ASSERT(m_imageIndexAcquired < m_swapchainObject.GetImageCount(),
                         "Present, acquired image index out of range");
+        m_renderPassManager->OnPresent();
         auto& frame = m_frameContext.GetCurrent();
         auto* activeRenderPass = VkRenderPassManager::GetActiveRenderPass();
         if (activeRenderPass)