From 67d03aabd0c9b57d00e18d0aca8aca60e27f2ea9 Mon Sep 17 00:00:00 2001
From: Philip Rebohle <philip.rebohle@tu-dortmund.de>
Date: Tue, 21 Jun 2022 19:14:32 +0200
Subject: [PATCH] [dxvk] Make recycler a ring buffer

Ensures that recycled objects actually get reused soon. Somewhat
important for memory efficiency in descriptor pools.
---
 src/dxvk/dxvk_recycler.h | 16 +++++++++-------
 1 file changed, 9 insertions(+), 7 deletions(-)

diff --git a/src/dxvk/dxvk_recycler.h b/src/dxvk/dxvk_recycler.h
index b90befd4..2dd1d595 100644
--- a/src/dxvk/dxvk_recycler.h
+++ b/src/dxvk/dxvk_recycler.h
@@ -31,10 +31,10 @@ namespace dxvk {
     Rc<T> retrieveObject() {
       std::lock_guard<dxvk::mutex> lock(m_mutex);
       
-      if (m_objectId == 0)
+      if (m_get == m_put)
         return nullptr;
       
-      return m_objects.at(--m_objectId);
+      return std::exchange(m_objects[(m_get++) % N], Rc<T>());
     }
     
     /**
@@ -48,15 +48,17 @@ namespace dxvk {
     void returnObject(const Rc<T>& object) {
       std::lock_guard<dxvk::mutex> lock(m_mutex);
       
-      if (m_objectId < N)
-        m_objects.at(m_objectId++) = object;
+      if (m_put - m_get < N)
+        m_objects[(m_put++) % N] = object;
     }
     
   private:
     
-    dxvk::mutex          m_mutex;
-    std::array<Rc<T>, N> m_objects;
-    size_t               m_objectId = 0;
+    dxvk::mutex           m_mutex;
+    std::array<Rc<T>, N>  m_objects;
+
+    uint64_t              m_get = 0;
+    uint64_t              m_put = 0;
     
   };