From 77e279721923e9dd476a4f815e05062014cf4971 Mon Sep 17 00:00:00 2001
From: PixelyIon <pixelyion@protonmail.com>
Date: Sun, 6 Mar 2022 21:18:54 +0530
Subject: [PATCH] Delete expired `weak_ptr`s for Texture/Buffer views

A large amount of Texture/Buffer views would expire before reuse could occur in `Texture::GetView`/`Buffer::GetView`. These can lead to a substantial memory allocation given enough time and they are now deleted during the lookup while iterating on all entries.

It should be noted that there are a lot of duplicate views that don't live long enough to be reused and the ultimate solution here is to make those views live long enough to be reused.
---
 app/src/main/cpp/skyline/gpu/buffer.cpp          | 8 ++++++--
 app/src/main/cpp/skyline/gpu/texture/texture.cpp | 8 ++++++--
 2 files changed, 12 insertions(+), 4 deletions(-)

diff --git a/app/src/main/cpp/skyline/gpu/buffer.cpp b/app/src/main/cpp/skyline/gpu/buffer.cpp
index 62777ef7..7ff5c92e 100644
--- a/app/src/main/cpp/skyline/gpu/buffer.cpp
+++ b/app/src/main/cpp/skyline/gpu/buffer.cpp
@@ -172,10 +172,14 @@ namespace skyline::gpu {
     }
 
     std::shared_ptr<BufferView> Buffer::GetView(vk::DeviceSize offset, vk::DeviceSize range, vk::Format format) {
-        for (const auto &viewWeak : views) {
-            auto view{viewWeak.lock()};
+        for (auto viewIt{views.begin()}; viewIt != views.end();) {
+            auto view{viewIt->lock()};
             if (view && view->offset == offset && view->range == range && view->format == format)
                 return view;
+            else if (!view)
+                viewIt = views.erase(viewIt);
+            else
+                ++viewIt;
         }
 
         auto view{std::make_shared<BufferView>(shared_from_this(), offset, range, format)};
diff --git a/app/src/main/cpp/skyline/gpu/texture/texture.cpp b/app/src/main/cpp/skyline/gpu/texture/texture.cpp
index 5b9ba371..106e64ec 100644
--- a/app/src/main/cpp/skyline/gpu/texture/texture.cpp
+++ b/app/src/main/cpp/skyline/gpu/texture/texture.cpp
@@ -515,10 +515,14 @@ namespace skyline::gpu {
     }
 
     std::shared_ptr<TextureView> Texture::GetView(vk::ImageViewType type, vk::ImageSubresourceRange range, texture::Format pFormat, vk::ComponentMapping mapping) {
-        for (const auto &viewWeak : views) {
-            auto view{viewWeak.lock()};
+        for (auto viewIt{views.begin()}; viewIt != views.end();) {
+            auto view{viewIt->lock()};
             if (view && type == view->type && pFormat == view->format && range == view->range && mapping == view->mapping)
                 return view;
+            else if (!view)
+                viewIt = views.erase(viewIt);
+            else
+                ++viewIt;
         }
 
         auto view{std::make_shared<TextureView>(shared_from_this(), type, range, pFormat, mapping)};