Change VkPipelineStateCahce to use Hash and LRU LList.

src/gpu/vk/GrVkPipelineStateCache.cpp

 /*
  * Copyright 2016 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "GrVkResourceProvider.h"
 
 #include "GrVkGpu.h"
 #include "GrProcessor.h"
 #include "GrVkPipelineState.h"
 #include "GrVkPipelineStateBuilder.h"
 #include "SkRTConf.h"
-#include "SkTSearch.h"
 #include "glsl/GrGLSLFragmentProcessor.h"
 #include "glsl/GrGLSLProgramDataManager.h"
 
-#ifdef PIPELINE_STATE_CACHE_STATS
-SK_CONF_DECLARE(bool, c_DisplayCache, "gpu.displayCache", false,
+#ifdef GR_PIPELINE_STATE_CACHE_STATS
+SK_CONF_DECLARE(bool, c_DisplayVkPipelineCache, "gpu.displayyVkPipelineCache", false,
                 "Display pipeline state cache usage.");
 #endif
 
-typedef GrGLSLProgramDataManager::UniformHandle UniformHandle;
-
 struct GrVkResourceProvider::PipelineStateCache::Entry {
 
-    Entry() : fPipelineState(nullptr), fLRUStamp(0) {}
+    Entry() : fPipelineState(nullptr) {}
 
-    SkAutoTUnref<GrVkPipelineState> fPipelineState;
-    unsigned int                    fLRUStamp;
-};
-
-struct GrVkResourceProvider::PipelineStateCache::PipelineDescLess {
-    bool operator() (const GrVkPipelineState::Desc& desc, const Entry* entry) {
-        SkASSERT(entry->fPipelineState.get());
-        return GrVkPipelineState::Desc::Less(desc, entry->fPipelineState->getDesc());
+    static const GrVkPipelineState::Desc& GetKey(const Entry* entry) {
+        return entry->fPipelineState->getDesc();
     }
 
-    bool operator() (const Entry* entry, const GrVkPipelineState::Desc& desc) {
-        SkASSERT(entry->fPipelineState.get());
-        return GrVkPipelineState::Desc::Less(entry->fPipelineState->getDesc(), desc);
+    static uint32_t Hash(const GrVkPipelineState::Desc& key) {
+        return key.fChecksum;
     }
+
+    sk_sp<GrVkPipelineState> fPipelineState;
+
+private:
+    SK_DECLARE_INTERNAL_LLIST_INTERFACE(Entry);
 };
 
 GrVkResourceProvider::PipelineStateCache::PipelineStateCache(GrVkGpu* gpu)
     : fCount(0)
-    , fCurrLRUStamp(0)
     , fGpu(gpu)
-#ifdef PIPELINE_STATE_CACHE_STATS
+#ifdef GR_PIPELINE_STATE_CACHE_STATS
     , fTotalRequests(0)
     , fCacheMisses(0)
-    , fHashMisses(0)
 #endif
-{
-    for (int i = 0; i < 1 << kHashBits; ++i) {
-        fHashTable[i] = nullptr;
-    }
-}
+{}
 
 GrVkResourceProvider::PipelineStateCache::~PipelineStateCache() {
     SkASSERT(0 == fCount);
     // dump stats
-#ifdef PIPELINE_STATE_CACHE_STATS
-    if (c_DisplayCache) {
+#ifdef GR_PIPELINE_STATE_CACHE_STATS
+    if (c_DisplayVkPipelineCache) {
         SkDebugf("--- Pipeline State Cache ---\n");
         SkDebugf("Total requests: %d\n", fTotalRequests);
         SkDebugf("Cache misses: %d\n", fCacheMisses);
         SkDebugf("Cache miss %%: %f\n", (fTotalRequests > 0) ?
                  100.f * fCacheMisses / fTotalRequests :
                  0.f);
-        int cacheHits = fTotalRequests - fCacheMisses;
-        SkDebugf("Hash miss %%: %f\n", (cacheHits > 0) ? 100.f * fHashMisses / cacheHits : 0.f);
         SkDebugf("---------------------\n");
     }
 #endif
 }
 
 void GrVkResourceProvider::PipelineStateCache::reset() {
-    for (int i = 0; i < fCount; ++i) {
-        delete fEntries[i];
-        fEntries[i] = nullptr;
-    }
+    fHashTable.foreach([](Entry** entry) {
+        delete *entry;
+    });
+    fHashTable.reset();
     fCount = 0;
-
-    // zero out hash table
-    for (int i = 0; i < 1 << kHashBits; i++) {
-        fHashTable[i] = nullptr;
-    }
-
-    fCurrLRUStamp = 0;
 }
 
 void GrVkResourceProvider::PipelineStateCache::abandon() {
-    for (int i = 0; i < fCount; ++i) {
-        SkASSERT(fEntries[i]->fPipelineState.get());
-        fEntries[i]->fPipelineState->abandonGPUResources();
-    }
+    fHashTable.foreach([](Entry** entry) {
+        SkASSERT((*entry)->fPipelineState.get());
+        (*entry)->fPipelineState->abandonGPUResources();
+    });
+
     this->reset();
 }
 
 void GrVkResourceProvider::PipelineStateCache::release() {
-    for (int i = 0; i < fCount; ++i) {
-        SkASSERT(fEntries[i]->fPipelineState.get());
-        fEntries[i]->fPipelineState->freeGPUResources(fGpu);
-    }
+    fHashTable.foreach([this](Entry** entry) {
+        SkASSERT((*entry)->fPipelineState.get());
+        (*entry)->fPipelineState->freeGPUResources(fGpu);
+    });
+
     this->reset();
 }
 
-int GrVkResourceProvider::PipelineStateCache::search(const GrVkPipelineState::Desc& desc) const {
-    PipelineDescLess less;
-    return SkTSearch(fEntries, fCount, desc, sizeof(Entry*), less);
-}
-
-GrVkPipelineState* GrVkResourceProvider::PipelineStateCache::refPipelineState(
+sk_sp<GrVkPipelineState> GrVkResourceProvider::PipelineStateCache::refPipelineState(
                                                                const GrPipeline& pipeline,
                                                                const GrPrimitiveProcessor& primProc,
-                                                               GrPrimitiveType primiteType,
+                                                               GrPrimitiveType primitiveType,
                                                                const GrVkRenderPass& renderPass) {
-#ifdef PIPELINE_STATE_CACHE_STATS
+#ifdef GR_PIPELINE_STATE_CACHE_STATS
     ++fTotalRequests;
 #endif
-
-    Entry* entry = nullptr;
-
     // Get GrVkProgramDesc
     GrVkPipelineState::Desc desc;
     if (!GrVkProgramDescBuilder::Build(&desc.fProgramDesc,
                                        primProc,
                                        pipeline,
                                        *fGpu->vkCaps().glslCaps())) {
         GrCapsDebugf(fGpu->caps(), "Failed to build vk program descriptor!\n");
         return false;
     }
 
     // Get vulkan specific descriptor key
-    GrVkPipelineState::BuildStateKey(pipeline, primiteType, &desc.fStateKey);
+    GrVkPipelineState::BuildStateKey(pipeline, primitiveType, &desc.fStateKey);
     // Get checksum of entire PipelineDesc
     int keyLength = desc.fStateKey.count();
     SkASSERT(0 == (keyLength % 4));
     // Seed the checksum with the checksum of the programDesc then add the vulkan key to it.
     desc.fChecksum = SkChecksum::Murmur3(desc.fStateKey.begin(), keyLength,
                                          desc.fProgramDesc.getChecksum());
 
-    uint32_t hashIdx = desc.fChecksum;
-    hashIdx ^= hashIdx >> 16;
-    if (kHashBits <= 8) {
-        hashIdx ^= hashIdx >> 8;
+    Entry* entry = nullptr;
+    if (Entry** entryptr = fHashTable.find(desc)) {
+        SkASSERT(*entryptr);
+        entry = *entryptr;
     }
-    hashIdx &= ((1 << kHashBits) - 1);
-    Entry* hashedEntry = fHashTable[hashIdx];
-    if (hashedEntry && hashedEntry->fPipelineState->getDesc() == desc) {
-        SkASSERT(hashedEntry->fPipelineState);
-        entry = hashedEntry;
-    }
-
-    int entryIdx;
-    if (nullptr == entry) {
-        entryIdx = this->search(desc);
-        if (entryIdx >= 0) {
-            entry = fEntries[entryIdx];
-#ifdef PIPELINE_STATE_CACHE_STATS
-            ++fHashMisses;
-#endif
-        }
-    }
-
-    if (nullptr == entry) {
-        // We have a cache miss
-#ifdef PIPELINE_STATE_CACHE_STATS
+    if (!entry) {
+#ifdef GR_PIPELINE_STATE_CACHE_STATS
         ++fCacheMisses;
 #endif
-        GrVkPipelineState* pipelineState =
+        sk_sp<GrVkPipelineState> pipelineState(
             GrVkPipelineStateBuilder::CreatePipelineState(fGpu,
                                                           pipeline,
                                                           primProc,
-                                                          primiteType,
+                                                          primitiveType,
                                                           desc,
-                                                          renderPass);
+                                                          renderPass));
         if (nullptr == pipelineState) {
             return nullptr;
         }
-        int purgeIdx = 0;
         if (fCount < kMaxEntries) {
             entry = new Entry;
-            purgeIdx = fCount++;
-            fEntries[purgeIdx] = entry;
+            fCount++;
         } else {
             SkASSERT(fCount == kMaxEntries);
-            purgeIdx = 0;
-            for (int i = 1; i < kMaxEntries; ++i) {
-                if (fEntries[i]->fLRUStamp < fEntries[purgeIdx]->fLRUStamp) {
-                    purgeIdx = i;
-                }
-            }
-            entry = fEntries[purgeIdx];
-            int purgedHashIdx = entry->fPipelineState->getDesc().fChecksum & ((1 << kHashBits) - 1);
-            if (fHashTable[purgedHashIdx] == entry) {
-                fHashTable[purgedHashIdx] = nullptr;
-            }
+            entry = fLRUList.head();
+            fLRUList.remove(entry);
             entry->fPipelineState->freeGPUResources(fGpu);
+            fHashTable.remove(entry->fPipelineState->getDesc());
         }
-        SkASSERT(fEntries[purgeIdx] == entry);
-        entry->fPipelineState.reset(pipelineState);
-        // We need to shift fEntries around so that the entry currently at purgeIdx is placed
-        // just before the entry at ~entryIdx (in order to keep fEntries sorted by descriptor).
-        entryIdx = ~entryIdx;
-        if (entryIdx < purgeIdx) {
-            //  Let E and P be the entries at index entryIdx and purgeIdx, respectively.
-            //  If the entries array looks like this:
-            //       aaaaEbbbbbPccccc
-            //  we rearrange it to look like this:
-            //       aaaaPEbbbbbccccc
-            size_t copySize = (purgeIdx - entryIdx) * sizeof(Entry*);
-            memmove(fEntries + entryIdx + 1, fEntries + entryIdx, copySize);
-            fEntries[entryIdx] = entry;
-        } else if (purgeIdx < entryIdx) {
-            //  If the entries array looks like this:
-            //       aaaaPbbbbbEccccc
-            //  we rearrange it to look like this:
-            //       aaaabbbbbPEccccc
-            size_t copySize = (entryIdx - purgeIdx - 1) * sizeof(Entry*);
-            memmove(fEntries + purgeIdx, fEntries + purgeIdx + 1, copySize);
-            fEntries[entryIdx - 1] = entry;
-        }
-#ifdef SK_DEBUG
-        SkASSERT(fEntries[0]->fPipelineState.get());
-        for (int i = 0; i < fCount - 1; ++i) {
-            SkASSERT(fEntries[i + 1]->fPipelineState.get());
-            const GrVkPipelineState::Desc& a = fEntries[i]->fPipelineState->getDesc();
-            const GrVkPipelineState::Desc& b = fEntries[i + 1]->fPipelineState->getDesc();
-            SkASSERT(GrVkPipelineState::Desc::Less(a, b));
-            SkASSERT(!GrVkPipelineState::Desc::Less(b, a));
-        }
-#endif
+        entry->fPipelineState = std::move(pipelineState);
+        fHashTable.set(entry);
+        fLRUList.addToTail(entry);
+        return entry->fPipelineState;
+    } else {
+        fLRUList.remove(entry);
+        fLRUList.addToTail(entry);
     }
-
-    fHashTable[hashIdx] = entry;
-    entry->fLRUStamp = fCurrLRUStamp;
-
-    if (SK_MaxU32 == fCurrLRUStamp) {
-        // wrap around! just trash our LRU, one time hit.
-        for (int i = 0; i < fCount; ++i) {
-            fEntries[i]->fLRUStamp = 0;
-        }
-    }
-    ++fCurrLRUStamp;
-    return SkRef(entry->fPipelineState.get());
+    return entry->fPipelineState;
 }