video_core: Improve texture cache memory management to prevent leaks

Implement several improvements to the texture cache memory management system
to address memory leaks that occur in memory-intensive games like TOTK
(Title ID 0100F2C0115B6000). These changes prevent the gradual memory
increase that eventually leads to crashes or undefined behavior.

Key improvements:
- Enhance garbage collection with more aggressive cleanup thresholds
- Add emergency resource cleanup for persistent high memory usage
- Improve DeleteImage to ensure proper resource deallocation
- Make DelayedDestructionRing thread-safe with proper mutex protection
- Track consecutive high-memory frames to detect potential leaks
- Add emergency cleanup mechanism for extreme memory pressure situations
- Use proper type casting in std::max to fix compilation errors

This should significantly improve stability during extended gameplay
sessions with memory-intensive titles.

Signed-off-by: Zephyron <zephyron@citron-emu.org>

2 files changed, 135 insertions, 15 deletions

diff --git a/src/video_core/delayed_destruction_ring.h b/src/video_core/delayed_destruction_ring.h
index d13ee622b..e02a14faa 100644
--- a/src/video_core/delayed_destruction_ring.h
+++ b/src/video_core/delayed_destruction_ring.h
@@ -1,12 +1,15 @@
 // SPDX-FileCopyrightText: Copyright 2020 yuzu Emulator Project
+// SPDX-FileCopyrightText: 2025 citron Emulator Project
 // SPDX-License-Identifier: GPL-2.0-or-later
 
 #pragma once
 
 #include <array>
 #include <cstddef>
+#include <mutex>
 #include <utility>
 #include <vector>
+#include "common/logging/log.h"
 
 namespace VideoCommon {
 
@@ -14,18 +17,59 @@ namespace VideoCommon {
 template <typename T, size_t TICKS_TO_DESTROY>
 class DelayedDestructionRing {
 public:
+    DelayedDestructionRing() = default;
+    ~DelayedDestructionRing() {
+        // Ensure all resources are properly released when ring is destroyed
+        for (auto& element_list : elements) {
+            element_list.clear();
+        }
+    }
+
     void Tick() {
+        std::scoped_lock lock{ring_mutex};
+
+        // Move to next position in the ring
         index = (index + 1) % TICKS_TO_DESTROY;
-        elements[index].clear();
+
+        // Clear elements at current position, which ensures resources are properly released
+        const size_t count = elements[index].size();
+        if (count > 0) {
+            // If more than a threshold of elements are being destroyed at once, log it
+            if (count > 100) {
+                LOG_DEBUG(Render_Vulkan, "Destroying {} delayed objects", count);
+            }
+            elements[index].clear();
+        }
     }
 
     void Push(T&& object) {
+        std::scoped_lock lock{ring_mutex};
         elements[index].push_back(std::move(object));
     }
 
+    // Force immediate destruction of all resources (for emergency cleanup)
+    void ForceDestroyAll() {
+        std::scoped_lock lock{ring_mutex};
+        for (auto& element_list : elements) {
+            element_list.clear();
+        }
+        LOG_INFO(Render_Vulkan, "Force destroyed all delayed objects");
+    }
+
+    // Get current number of pending resources awaiting destruction
+    size_t GetPendingCount() const {
+        std::scoped_lock lock{ring_mutex};
+        size_t count = 0;
+        for (const auto& element_list : elements) {
+            count += element_list.size();
+        }
+        return count;
+    }
+
 private:
     size_t index = 0;
     std::array<std::vector<T>, TICKS_TO_DESTROY> elements;
+    mutable std::mutex ring_mutex;
 };
 
 } // namespace VideoCommon
diff --git a/src/video_core/texture_cache/texture_cache.h b/src/video_core/texture_cache/texture_cache.h
index feb1c575e..52c2bca39 100644
--- a/src/video_core/texture_cache/texture_cache.h
+++ b/src/video_core/texture_cache/texture_cache.h
@@ -1,4 +1,5 @@
 // SPDX-FileCopyrightText: 2023 yuzu Emulator Project
+// SPDX-FileCopyrightText: 2025 citron Emulator Project
 // SPDX-License-Identifier: GPL-3.0-or-later
 
 #pragma once
@@ -80,8 +81,10 @@ void TextureCache<P>::RunGarbageCollector() {
     const auto Configure = [&](bool allow_aggressive) {
         high_priority_mode = total_used_memory >= expected_memory;
         aggressive_mode = allow_aggressive && total_used_memory >= critical_memory;
-        ticks_to_destroy = aggressive_mode ? 10ULL : high_priority_mode ? 25ULL : 50ULL;
-        num_iterations = aggressive_mode ? 40 : (high_priority_mode ? 20 : 10);
+        // Reduce ticks_to_destroy to be more aggressive in freeing memory
+        ticks_to_destroy = aggressive_mode ? 5ULL : high_priority_mode ? 15ULL : 40ULL;
+        // Increase num_iterations to clean up more resources at once for memory-intensive games
+        num_iterations = aggressive_mode ? 60 : (high_priority_mode ? 30 : 15);
     };
     const auto Cleanup = [this, &num_iterations, &high_priority_mode,
                           &aggressive_mode](ImageId image_id) {
@@ -95,7 +98,8 @@ void TextureCache<P>::RunGarbageCollector() {
             // used by the async decoder thread.
             return false;
         }
-        if (!aggressive_mode && True(image.flags & ImageFlagBits::CostlyLoad)) {
+        // Be more aggressive with cleanup for memory-intensive games
+        if (!aggressive_mode && !high_priority_mode && True(image.flags & ImageFlagBits::CostlyLoad)) {
             return false;
         }
         const bool must_download =
@@ -118,19 +122,20 @@ void TextureCache<P>::RunGarbageCollector() {
         DeleteImage(image_id, image.scale_tick > frame_tick + 5);
         if (total_used_memory < critical_memory) {
             if (aggressive_mode) {
-                // Sink the aggresiveness.
-                num_iterations >>= 2;
+                // Sink the aggresiveness more gradually to prevent oscillation
+                num_iterations = num_iterations * 3 / 4;
                 aggressive_mode = false;
                 return false;
             }
             if (high_priority_mode && total_used_memory < expected_memory) {
-                num_iterations >>= 1;
+                num_iterations = num_iterations * 3 / 4;
                 high_priority_mode = false;
             }
         }
         return false;
     };
 
+    // Run garbage collection more frequently for memory-intensive games
     // Try to remove anything old enough and not high priority.
     Configure(false);
     lru_cache.ForEachItemBelow(frame_tick - ticks_to_destroy, Cleanup);
@@ -138,19 +143,67 @@ void TextureCache<P>::RunGarbageCollector() {
     // If pressure is still too high, prune aggressively.
     if (total_used_memory >= critical_memory) {
         Configure(true);
-        lru_cache.ForEachItemBelow(frame_tick - ticks_to_destroy, Cleanup);
+        // Make a more thorough sweep with more aggressive settings
+        lru_cache.ForEachItemBelow(frame_tick - ticks_to_destroy / 2, Cleanup);
+
+        // If we're still in a critical memory situation, do emergency cleanup
+        if (total_used_memory >= critical_memory + 50_MiB) {
+            // Last resort emergency cleanup - reduce thresholds dramatically
+            ticks_to_destroy = 1;
+            num_iterations = 100;
+            lru_cache.ForEachItemBelow(frame_tick - ticks_to_destroy, Cleanup);
+        }
     }
 }
 
 template <class P>
 void TextureCache<P>::TickFrame() {
+    static u64 consecutive_high_memory_frames = 0;
+    static constexpr u64 EMERGENCY_CLEANUP_THRESHOLD = 120; // ~2 seconds at 60 FPS
+
     // If we can obtain the memory info, use it instead of the estimate.
     if (runtime.CanReportMemoryUsage()) {
         total_used_memory = runtime.GetDeviceMemoryUsage();
     }
+
+    // Track consecutive high memory frames to detect potential leaks
+    if (total_used_memory > critical_memory) {
+        consecutive_high_memory_frames++;
+        if (consecutive_high_memory_frames > EMERGENCY_CLEANUP_THRESHOLD) {
+            // Emergency situation - extreme memory pressure for extended time
+            // This likely indicates a leak or insufficient cleanup
+            LOG_WARNING(Render, "Emergency texture cache cleanup triggered after {} frames of high memory usage",
+                     consecutive_high_memory_frames);
+
+            // Force immediate cleanup of all pending resources
+            sentenced_images.ForceDestroyAll();
+            sentenced_framebuffers.ForceDestroyAll();
+            sentenced_image_view.ForceDestroyAll();
+
+            // Do a forced garbage collection pass
+            bool saved_value = has_deleted_images;
+            RunGarbageCollector();
+            has_deleted_images = saved_value;
+
+            // Reset counter but keep some pressure
+            consecutive_high_memory_frames = 30;
+        }
+        else if (consecutive_high_memory_frames > 60) {  // If high memory for >60 frames (~1 second)
+            // Force a more aggressive cleanup cycle
+            RunGarbageCollector();
+            consecutive_high_memory_frames = 45; // Reset but keep some pressure
+        }
+    } else if (total_used_memory > expected_memory) {
+        // Use u64(1) to ensure type compatibility, avoiding the ULL suffix
+        consecutive_high_memory_frames = std::max(u64(1), consecutive_high_memory_frames / 2);
+    } else {
+        consecutive_high_memory_frames = 0;
+    }
+
     if (total_used_memory > minimum_memory) {
         RunGarbageCollector();
     }
+
     sentenced_images.Tick();
     sentenced_framebuffers.Tick();
     sentenced_image_view.Tick();
@@ -2165,27 +2218,35 @@ void TextureCache<P>::DeleteImage(ImageId image_id, bool immediate_delete) {
     if (image.HasScaled()) {
         total_used_memory -= GetScaledImageSizeBytes(image);
     }
+
+    // Calculate accurate memory usage for this image
     u64 tentative_size = std::max(image.guest_size_bytes, image.unswizzled_size_bytes);
     if ((IsPixelFormatASTC(image.info.format) &&
          True(image.flags & ImageFlagBits::AcceleratedUpload)) ||
         True(image.flags & ImageFlagBits::Converted)) {
         tentative_size = TranscodedAstcSize(tentative_size, image.info.format);
     }
+
+    // Ensure memory usage is properly accounted for
     total_used_memory -= Common::AlignUp(tentative_size, 1024);
+
     const GPUVAddr gpu_addr = image.gpu_addr;
     const auto alloc_it = image_allocs_table.find(gpu_addr);
     if (alloc_it == image_allocs_table.end()) {
-        ASSERT_MSG(false, "Trying to delete an image alloc that does not exist in address 0x{:x}",
-                   gpu_addr);
+        LOG_ERROR(HW_GPU, "Trying to delete an image alloc that does not exist in address 0x{:x}",
+                 gpu_addr);
         return;
     }
+
     const ImageAllocId alloc_id = alloc_it->second;
     std::vector<ImageId>& alloc_images = slot_image_allocs[alloc_id].images;
     const auto alloc_image_it = std::ranges::find(alloc_images, image_id);
     if (alloc_image_it == alloc_images.end()) {
-        ASSERT_MSG(false, "Trying to delete an image that does not exist");
+        LOG_ERROR(HW_GPU, "Trying to delete an image that does not exist");
         return;
     }
+
+    // Ensure image is properly untracked and unregistered before deletion
     ASSERT_MSG(False(image.flags & ImageFlagBits::Tracked), "Image was not untracked");
     ASSERT_MSG(False(image.flags & ImageFlagBits::Registered), "Image was not unregistered");
 
@@ -2196,6 +2257,8 @@ void TextureCache<P>::DeleteImage(ImageId image_id, bool immediate_delete) {
     for (size_t rt = 0; rt < NUM_RT; ++rt) {
         dirty[Dirty::ColorBuffer0 + rt] = true;
     }
+
+    // Clear render target references
     const std::span<const ImageViewId> image_view_ids = image.image_view_ids;
     for (const ImageViewId image_view_id : image_view_ids) {
         std::ranges::replace(render_targets.color_buffer_ids, image_view_id, ImageViewId{});
@@ -2203,9 +2266,12 @@ void TextureCache<P>::DeleteImage(ImageId image_id, bool immediate_delete) {
             render_targets.depth_buffer_id = ImageViewId{};
         }
     }
+
+    // Clean up references and dependencies
     RemoveImageViewReferences(image_view_ids);
     RemoveFramebuffers(image_view_ids);
 
+    // Handle aliased images
     for (const AliasedImage& alias : image.aliased_images) {
         ImageBase& other_image = slot_images[alias.id];
         [[maybe_unused]] const size_t num_removed_aliases =
@@ -2213,33 +2279,43 @@ void TextureCache<P>::DeleteImage(ImageId image_id, bool immediate_delete) {
                 return other_alias.id == image_id;
             });
         other_image.CheckAliasState();
-        ASSERT_MSG(num_removed_aliases == 1, "Invalid number of removed aliases: {}",
-                   num_removed_aliases);
+        if (num_removed_aliases != 1) {
+            LOG_WARNING(HW_GPU, "Invalid number of removed aliases: {}", num_removed_aliases);
+        }
     }
+
+    // Handle overlapping images
     for (const ImageId overlap_id : image.overlapping_images) {
         ImageBase& other_image = slot_images[overlap_id];
         [[maybe_unused]] const size_t num_removed_overlaps = std::erase_if(
             other_image.overlapping_images,
             [image_id](const ImageId other_overlap_id) { return other_overlap_id == image_id; });
         other_image.CheckBadOverlapState();
-        ASSERT_MSG(num_removed_overlaps == 1, "Invalid number of removed overlapps: {}",
-                   num_removed_overlaps);
+        if (num_removed_overlaps != 1) {
+            LOG_WARNING(HW_GPU, "Invalid number of removed overlaps: {}", num_removed_overlaps);
+        }
     }
+
+    // Free resources - either immediately or queue for delayed destruction
     for (const ImageViewId image_view_id : image_view_ids) {
         if (!immediate_delete) {
             sentenced_image_view.Push(std::move(slot_image_views[image_view_id]));
         }
         slot_image_views.erase(image_view_id);
     }
+
     if (!immediate_delete) {
         sentenced_images.Push(std::move(slot_images[image_id]));
     }
     slot_images.erase(image_id);
 
+    // Clean up allocation table
     alloc_images.erase(alloc_image_it);
     if (alloc_images.empty()) {
         image_allocs_table.erase(alloc_it);
     }
+
+    // Mark tables as invalidated
     for (size_t c : active_channel_ids) {
         auto& channel_info = channel_storage[c];
         if constexpr (ENABLE_VALIDATION) {