From 707ddd63a1fc9c0c0875a785d8fb9367152ff9c6 Mon Sep 17 00:00:00 2001
From: Philip Rebohle <philip.rebohle@tu-dortmund.de>
Date: Fri, 27 Sep 2024 17:04:37 +0200
Subject: [PATCH] [dxvk] Add stat counter for samplers

---
 src/dxvk/dxvk_device.h    |  8 ++++++++
 src/dxvk/dxvk_sampler.cpp | 12 +++++++++++-
 src/dxvk/dxvk_sampler.h   | 29 ++++++++++++++++++++++++++++-
 3 files changed, 47 insertions(+), 2 deletions(-)

diff --git a/src/dxvk/dxvk_device.h b/src/dxvk/dxvk_device.h
index 26ea98bc3..9876aafb5 100644
--- a/src/dxvk/dxvk_device.h
+++ b/src/dxvk/dxvk_device.h
@@ -401,6 +401,14 @@ namespace dxvk {
      */
     DxvkSharedAllocationCacheStats getMemoryAllocationStats(DxvkMemoryAllocationStats& stats);
 
+    /**
+     * \brief Queries sampler statistics
+     * \returns Sampler stats
+     */
+    DxvkSamplerStats getSamplerStats() {
+      return m_objects.samplerPool().getStats();
+    }
+
     /**
      * \brief Retreves current frame ID
      * \returns Current frame ID
diff --git a/src/dxvk/dxvk_sampler.cpp b/src/dxvk/dxvk_sampler.cpp
index 7555034ea..f2ae525f3 100644
--- a/src/dxvk/dxvk_sampler.cpp
+++ b/src/dxvk/dxvk_sampler.cpp
@@ -151,6 +151,8 @@ namespace dxvk {
 
         sampler->m_lruPrev = nullptr;
         sampler->m_lruNext = nullptr;
+
+        m_samplersLive.store(m_samplersLive.load() + 1u);
       }
 
       // We already took a reference, forward the pointer as-is
@@ -163,9 +165,13 @@ namespace dxvk {
       destroyLeastRecentlyUsedSampler();
 
     // Create new sampler object
-    return &m_samplers.emplace(std::piecewise_construct,
+    DxvkSampler* sampler = &m_samplers.emplace(std::piecewise_construct,
       std::forward_as_tuple(key),
       std::forward_as_tuple(this, key)).first->second;
+
+    m_samplersTotal.store(m_samplers.size());
+    m_samplersLive.store(m_samplersLive.load() + 1u);
+    return sampler;
   }
 
 
@@ -195,6 +201,9 @@ namespace dxvk {
 
     m_lruTail = sampler;
 
+    // Don't need an atomic add for these
+    m_samplersLive.store(m_samplersLive.load() - 1u);
+
     // Try to keep some samplers available for subsequent allocations
     if (m_samplers.size() > MinSamplerCount)
       destroyLeastRecentlyUsedSampler();
@@ -213,6 +222,7 @@ namespace dxvk {
         m_lruTail = nullptr;
 
       m_samplers.erase(sampler->key());
+      m_samplersTotal.store(m_samplers.size());
     }
   }
 
diff --git a/src/dxvk/dxvk_sampler.h b/src/dxvk/dxvk_sampler.h
index 5ae7a475c..80589e5f7 100644
--- a/src/dxvk/dxvk_sampler.h
+++ b/src/dxvk/dxvk_sampler.h
@@ -195,7 +195,18 @@ namespace dxvk {
     VkBorderColor determineBorderColorType() const;
 
   };
-  
+
+
+  /**
+   * \brief Sampler statistics
+   */
+  struct DxvkSamplerStats {
+    /// Number of sampler objects created
+    uint32_t totalCount = 0u;
+    /// Number of samplers currently in use
+    uint32_t liveCount = 0u;
+  };
+
 
   /**
    * \brief Sampler pool
@@ -225,6 +236,19 @@ namespace dxvk {
      */
     Rc<DxvkSampler> createSampler(const DxvkSamplerKey& key);
 
+    /**
+     * \brief Retrieves sampler statistics
+     *
+     * Note that these might be out of date immediately.
+     * \returns Sampler counts
+     */
+    DxvkSamplerStats getStats() const {
+      DxvkSamplerStats stats = { };
+      stats.totalCount = m_samplersTotal.load();
+      stats.liveCount = m_samplersLive.load();
+      return stats;
+    }
+
   private:
 
     DxvkDevice* m_device;
@@ -236,6 +260,9 @@ namespace dxvk {
     DxvkSampler* m_lruHead = nullptr;
     DxvkSampler* m_lruTail = nullptr;
 
+    std::atomic<uint32_t> m_samplersLive = { 0u };
+    std::atomic<uint32_t> m_samplersTotal = { 0u };
+
     void releaseSampler(DxvkSampler* sampler);
 
     void destroyLeastRecentlyUsedSampler();