Revert "Revert "Add ExternalTexture class into RenderEngine inte..."

Revert submission 14199598-revert-14086921-renderengine-external-tex-QJNBWQMQEU

Reason for revert: Prepare for relanding
Reverted Changes:
I01e65a7f4:Revert "Update WaylandRenderSurface to accomodate ...
I7d58118c1:Revert "Update Readback VTS to align with RenderEn...
I1501890f4:Revert "Add ExternalTexture class into RenderEngin...

Added the following fixes:
1. CachedSet renders to intermediate texture variable rather than
mTexture directly, since mTexture is not guaranteed to be nonnull.
2. Add null check when setting new buffer in BLAST.

Bug: 185524947
Bug: 180767535
Test: builds, boots
Test: librenderengine_test
Change-Id: I52ea82e24336b496d996bbe3e445db0affe1abb8
diff --git a/libs/renderengine/skia/AutoBackendTexture.h b/libs/renderengine/skia/AutoBackendTexture.h
index bb75878..2d61cf8 100644
--- a/libs/renderengine/skia/AutoBackendTexture.h
+++ b/libs/renderengine/skia/AutoBackendTexture.h
@@ -21,9 +21,9 @@
 #include <SkImage.h>
 #include <SkSurface.h>
 #include <sys/types.h>
+#include <ui/GraphicTypes.h>
 
 #include "android-base/macros.h"
-#include "ui/GraphicTypes.h"
 
 namespace android {
 namespace renderengine {
@@ -41,13 +41,18 @@
     // of shared ownership with Skia objects, so we wrap it here instead.
     class LocalRef {
     public:
-        LocalRef() {}
+        LocalRef(AutoBackendTexture* texture) { setTexture(texture); }
 
         ~LocalRef() {
             // Destroying the texture is the same as setting it to null
             setTexture(nullptr);
         }
 
+        AutoBackendTexture* getTexture() const { return mTexture; }
+
+        DISALLOW_COPY_AND_ASSIGN(LocalRef);
+
+    private:
         // Sets the texture to locally ref-track.
         void setTexture(AutoBackendTexture* texture) {
             if (mTexture != nullptr) {
@@ -59,12 +64,6 @@
                 mTexture->ref();
             }
         }
-
-        AutoBackendTexture* getTexture() const { return mTexture; }
-
-        DISALLOW_COPY_AND_ASSIGN(LocalRef);
-
-    private:
         AutoBackendTexture* mTexture = nullptr;
     };
 
diff --git a/libs/renderengine/skia/Cache.cpp b/libs/renderengine/skia/Cache.cpp
index 1db20c0..1c2b2fc 100644
--- a/libs/renderengine/skia/Cache.cpp
+++ b/libs/renderengine/skia/Cache.cpp
@@ -46,7 +46,7 @@
 } // namespace
 
 static void drawShadowLayers(SkiaRenderEngine* renderengine, const DisplaySettings& display,
-                             sp<GraphicBuffer> dstBuffer) {
+                             const std::shared_ptr<ExternalTexture>& dstTexture) {
     // Somewhat arbitrary dimensions, but on screen and slightly shorter, based
     // on actual use.
     FloatRect rect(0, 0, display.physicalDisplay.width(), display.physicalDisplay.height() - 30);
@@ -73,7 +73,7 @@
 
     auto layers = std::vector<const LayerSettings*>{&layer};
     // The identity matrix will generate the fast shader
-    renderengine->drawLayers(display, layers, dstBuffer, kUseFrameBufferCache, base::unique_fd(),
+    renderengine->drawLayers(display, layers, dstTexture, kUseFrameBufferCache, base::unique_fd(),
                              nullptr);
     // This matrix, which has different scales for x and y, will
     // generate the slower (more general case) version, which has variants for translucent
@@ -86,13 +86,14 @@
     // clang-format on
     for (auto translucent : {false, true}) {
         layer.shadow.casterIsTranslucent = translucent;
-        renderengine->drawLayers(display, layers, dstBuffer, kUseFrameBufferCache,
+        renderengine->drawLayers(display, layers, dstTexture, kUseFrameBufferCache,
                                  base::unique_fd(), nullptr);
     }
 }
 
 static void drawImageLayers(SkiaRenderEngine* renderengine, const DisplaySettings& display,
-                            sp<GraphicBuffer> dstBuffer, sp<GraphicBuffer> srcBuffer) {
+                            const std::shared_ptr<ExternalTexture>& dstTexture,
+                            const std::shared_ptr<ExternalTexture>& srcTexture) {
     const Rect& displayRect = display.physicalDisplay;
     FloatRect rect(0, 0, displayRect.width(), displayRect.height());
     LayerSettings layer{
@@ -103,7 +104,7 @@
                     },
             .source = PixelSource{.buffer =
                                           Buffer{
-                                                  .buffer = srcBuffer,
+                                                  .buffer = srcTexture,
                                                   .maxMasteringLuminance = 1000.f,
                                                   .maxContentLuminance = 1000.f,
                                           }},
@@ -126,7 +127,7 @@
                 layer.source.buffer.isOpaque = isOpaque;
                 for (auto alpha : {half(.23999f), half(1.0f)}) {
                     layer.alpha = alpha;
-                    renderengine->drawLayers(display, layers, dstBuffer, kUseFrameBufferCache,
+                    renderengine->drawLayers(display, layers, dstTexture, kUseFrameBufferCache,
                                              base::unique_fd(), nullptr);
                 }
             }
@@ -135,7 +136,7 @@
 }
 
 static void drawSolidLayers(SkiaRenderEngine* renderengine, const DisplaySettings& display,
-                            sp<GraphicBuffer> dstBuffer) {
+                            const std::shared_ptr<ExternalTexture>& dstTexture) {
     const Rect& displayRect = display.physicalDisplay;
     FloatRect rect(0, 0, displayRect.width(), displayRect.height());
     LayerSettings layer{
@@ -143,11 +144,11 @@
                     Geometry{
                             .boundaries = rect,
                     },
-            .alpha = 1,
             .source =
                     PixelSource{
                             .solidColor = half3(0.1f, 0.2f, 0.3f),
                     },
+            .alpha = 1,
     };
 
     auto layers = std::vector<const LayerSettings*>{&layer};
@@ -155,14 +156,14 @@
         layer.geometry.positionTransform = transform;
         for (float roundedCornersRadius : {0.0f, 0.05f, 50.f}) {
             layer.geometry.roundedCornersRadius = roundedCornersRadius;
-            renderengine->drawLayers(display, layers, dstBuffer, kUseFrameBufferCache,
+            renderengine->drawLayers(display, layers, dstTexture, kUseFrameBufferCache,
                                      base::unique_fd(), nullptr);
         }
     }
 }
 
 static void drawBlurLayers(SkiaRenderEngine* renderengine, const DisplaySettings& display,
-                           sp<GraphicBuffer> dstBuffer) {
+                           const std::shared_ptr<ExternalTexture>& dstTexture) {
     const Rect& displayRect = display.physicalDisplay;
     FloatRect rect(0, 0, displayRect.width(), displayRect.height());
     LayerSettings layer{
@@ -176,7 +177,7 @@
     auto layers = std::vector<const LayerSettings*>{&layer};
     for (int radius : {9, 60}) {
         layer.backgroundBlurRadius = radius;
-        renderengine->drawLayers(display, layers, dstBuffer, kUseFrameBufferCache,
+        renderengine->drawLayers(display, layers, dstTexture, kUseFrameBufferCache,
                                  base::unique_fd(), nullptr);
     }
 }
@@ -214,6 +215,9 @@
     sp<GraphicBuffer> dstBuffer =
             new GraphicBuffer(displayRect.width(), displayRect.height(), PIXEL_FORMAT_RGBA_8888, 1,
                               usage, "primeShaderCache_dst");
+
+    const auto dstTexture = std::make_shared<ExternalTexture>(dstBuffer, *renderengine,
+                                                              ExternalTexture::Usage::WRITEABLE);
     // This buffer will be the source for the call to drawImageLayers. Draw
     // something to it as a placeholder for what an app draws. We should draw
     // something, but the details are not important. Make use of the shadow layer drawing step
@@ -222,11 +226,16 @@
             new GraphicBuffer(displayRect.width(), displayRect.height(), PIXEL_FORMAT_RGBA_8888, 1,
                               usage, "drawImageLayer_src");
 
-    drawSolidLayers(renderengine, display, dstBuffer);
-    drawShadowLayers(renderengine, display, srcBuffer);
-    drawBlurLayers(renderengine, display, dstBuffer);
+    const auto srcTexture =
+            std::make_shared<ExternalTexture>(srcBuffer, *renderengine,
+                                              ExternalTexture::Usage::READABLE |
+                                                      ExternalTexture::Usage::WRITEABLE);
+
+    drawSolidLayers(renderengine, display, dstTexture);
+    drawShadowLayers(renderengine, display, srcTexture);
+    drawBlurLayers(renderengine, display, dstTexture);
     // The majority of shaders are related to sampling images.
-    drawImageLayers(renderengine, display, dstBuffer, srcBuffer);
+    drawImageLayers(renderengine, display, dstTexture, srcTexture);
 
     // should be the same as AHARDWAREBUFFER_USAGE_GPU_SAMPLED_IMAGE;
     const int64_t usageExternal = GRALLOC_USAGE_HW_TEXTURE;
@@ -234,12 +243,12 @@
     sp<GraphicBuffer> externalBuffer =
             new GraphicBuffer(displayRect.width(), displayRect.height(), PIXEL_FORMAT_RGBA_8888, 1,
                               usageExternal, "primeShaderCache_external");
+    const auto externalTexture =
+            std::make_shared<ExternalTexture>(externalBuffer, *renderengine,
+                                              ExternalTexture::Usage::READABLE);
     // TODO(b/184665179) doubles number of image shader compilations, but only somewhere
     // between 6 and 8 will occur in real uses.
-    drawImageLayers(renderengine, display, dstBuffer, externalBuffer);
-    renderengine->unbindExternalTextureBuffer(externalBuffer->getId());
-
-    renderengine->unbindExternalTextureBuffer(srcBuffer->getId());
+    drawImageLayers(renderengine, display, dstTexture, externalTexture);
 
     const nsecs_t timeAfter = systemTime();
     const float compileTimeMs = static_cast<float>(timeAfter - timeBefore) / 1.0E6;
diff --git a/libs/renderengine/skia/SkiaGLRenderEngine.cpp b/libs/renderengine/skia/SkiaGLRenderEngine.cpp
index df40dd9..37d98a3 100644
--- a/libs/renderengine/skia/SkiaGLRenderEngine.cpp
+++ b/libs/renderengine/skia/SkiaGLRenderEngine.cpp
@@ -329,8 +329,6 @@
 }
 
 SkiaGLRenderEngine::~SkiaGLRenderEngine() {
-    cleanFramebufferCache();
-
     std::lock_guard<std::mutex> lock(mRenderingMutex);
     if (mBlurFilter) {
         delete mBlurFilter;
@@ -484,7 +482,8 @@
             sourceTransfer != destTransfer;
 }
 
-void SkiaGLRenderEngine::cacheExternalTextureBuffer(const sp<GraphicBuffer>& buffer) {
+void SkiaGLRenderEngine::mapExternalTextureBuffer(const sp<GraphicBuffer>& buffer,
+                                                  bool isRenderable) {
     // Only run this if RE is running on its own thread. This way the access to GL
     // operations is guaranteed to be happening on the same thread.
     if (mRenderEngineType != RenderEngineType::SKIA_GL_THREADED) {
@@ -505,25 +504,41 @@
     auto& cache = mInProtectedContext ? mProtectedTextureCache : mTextureCache;
 
     std::lock_guard<std::mutex> lock(mRenderingMutex);
-    auto iter = cache.find(buffer->getId());
-    if (iter != cache.end()) {
-        ALOGV("Texture already exists in cache.");
-    } else {
+    mGraphicBufferExternalRefs[buffer->getId()]++;
+
+    if (const auto& iter = cache.find(buffer->getId()); iter == cache.end()) {
         std::shared_ptr<AutoBackendTexture::LocalRef> imageTextureRef =
-                std::make_shared<AutoBackendTexture::LocalRef>();
-        imageTextureRef->setTexture(
-                new AutoBackendTexture(grContext.get(), buffer->toAHardwareBuffer(), false));
+                std::make_shared<AutoBackendTexture::LocalRef>(
+                        new AutoBackendTexture(grContext.get(), buffer->toAHardwareBuffer(),
+                                               isRenderable));
         cache.insert({buffer->getId(), imageTextureRef});
     }
     // restore the original state of the protected context if necessary
     useProtectedContext(protectedContextState);
 }
 
-void SkiaGLRenderEngine::unbindExternalTextureBuffer(uint64_t bufferId) {
+void SkiaGLRenderEngine::unmapExternalTextureBuffer(const sp<GraphicBuffer>& buffer) {
     ATRACE_CALL();
     std::lock_guard<std::mutex> lock(mRenderingMutex);
-    mTextureCache.erase(bufferId);
-    mProtectedTextureCache.erase(bufferId);
+    if (const auto& iter = mGraphicBufferExternalRefs.find(buffer->getId());
+        iter != mGraphicBufferExternalRefs.end()) {
+        if (iter->second == 0) {
+            ALOGW("Attempted to unmap GraphicBuffer <id: %" PRId64
+                  "> from RenderEngine texture, but the "
+                  "ref count was already zero!",
+                  buffer->getId());
+            mGraphicBufferExternalRefs.erase(buffer->getId());
+            return;
+        }
+
+        iter->second--;
+
+        if (iter->second == 0) {
+            mTextureCache.erase(buffer->getId());
+            mProtectedTextureCache.erase(buffer->getId());
+            mGraphicBufferExternalRefs.erase(buffer->getId());
+        }
+    }
 }
 
 sk_sp<SkShader> SkiaGLRenderEngine::createRuntimeEffectShader(sk_sp<SkShader> shader,
@@ -621,8 +636,8 @@
 
 status_t SkiaGLRenderEngine::drawLayers(const DisplaySettings& display,
                                         const std::vector<const LayerSettings*>& layers,
-                                        const sp<GraphicBuffer>& buffer,
-                                        const bool useFramebufferCache,
+                                        const std::shared_ptr<ExternalTexture>& buffer,
+                                        const bool /*useFramebufferCache*/,
                                         base::unique_fd&& bufferFence, base::unique_fd* drawFence) {
     ATRACE_NAME("SkiaGL::drawLayers");
 
@@ -645,32 +660,18 @@
         return BAD_VALUE;
     }
 
-    validateOutputBufferUsage(buffer);
+    validateOutputBufferUsage(buffer->getBuffer());
 
     auto grContext = mInProtectedContext ? mProtectedGrContext : mGrContext;
     auto& cache = mInProtectedContext ? mProtectedTextureCache : mTextureCache;
-    AHardwareBuffer_Desc bufferDesc;
-    AHardwareBuffer_describe(buffer->toAHardwareBuffer(), &bufferDesc);
 
-    std::shared_ptr<AutoBackendTexture::LocalRef> surfaceTextureRef = nullptr;
-    if (useFramebufferCache) {
-        auto iter = cache.find(buffer->getId());
-        if (iter != cache.end()) {
-            ALOGV("Cache hit!");
-            ATRACE_NAME("Cache hit");
-            surfaceTextureRef = iter->second;
-        }
-    }
-
-    if (surfaceTextureRef == nullptr || surfaceTextureRef->getTexture() == nullptr) {
-        ATRACE_NAME("Cache miss");
-        surfaceTextureRef = std::make_shared<AutoBackendTexture::LocalRef>();
-        surfaceTextureRef->setTexture(
-                new AutoBackendTexture(grContext.get(), buffer->toAHardwareBuffer(), true));
-        if (useFramebufferCache) {
-            ALOGD("Adding to cache");
-            cache.insert({buffer->getId(), surfaceTextureRef});
-        }
+    std::shared_ptr<AutoBackendTexture::LocalRef> surfaceTextureRef;
+    if (const auto& it = cache.find(buffer->getBuffer()->getId()); it != cache.end()) {
+        surfaceTextureRef = it->second;
+    } else {
+        surfaceTextureRef = std::make_shared<AutoBackendTexture::LocalRef>(
+                new AutoBackendTexture(grContext.get(), buffer->getBuffer()->toAHardwareBuffer(),
+                                       true));
     }
 
     const ui::Dataspace dstDataspace =
@@ -876,18 +877,22 @@
         SkPaint paint;
         if (layer->source.buffer.buffer) {
             ATRACE_NAME("DrawImage");
-            validateInputBufferUsage(layer->source.buffer.buffer);
+            validateInputBufferUsage(layer->source.buffer.buffer->getBuffer());
             const auto& item = layer->source.buffer;
             std::shared_ptr<AutoBackendTexture::LocalRef> imageTextureRef = nullptr;
-            auto iter = cache.find(item.buffer->getId());
-            if (iter != cache.end()) {
+
+            if (const auto& iter = cache.find(item.buffer->getBuffer()->getId());
+                iter != cache.end()) {
                 imageTextureRef = iter->second;
             } else {
-                imageTextureRef = std::make_shared<AutoBackendTexture::LocalRef>();
-                imageTextureRef->setTexture(new AutoBackendTexture(grContext.get(),
-                                                                   item.buffer->toAHardwareBuffer(),
-                                                                   false));
-                cache.insert({item.buffer->getId(), imageTextureRef});
+                // If we didn't find the image in the cache, then create a local ref but don't cache
+                // it. If we're using skia, we're guaranteed to run on a dedicated GPU thread so if
+                // we didn't find anything in the cache then we intentionally did not cache this
+                // buffer's resources.
+                imageTextureRef = std::make_shared<AutoBackendTexture::LocalRef>(
+                        new AutoBackendTexture(grContext.get(),
+                                               item.buffer->getBuffer()->toAHardwareBuffer(),
+                                               false));
             }
 
             sk_sp<SkImage> image =
@@ -1200,15 +1205,6 @@
     return eglCreatePbufferSurface(display, placeholderConfig, attributes.data());
 }
 
-void SkiaGLRenderEngine::cleanFramebufferCache() {
-    // TODO(b/180767535) Remove this method and use b/180767535 instead, which would allow
-    // SF to control texture lifecycle more tightly rather than through custom hooks into RE.
-    std::lock_guard<std::mutex> lock(mRenderingMutex);
-    mRuntimeEffects.clear();
-    mProtectedTextureCache.clear();
-    mTextureCache.clear();
-}
-
 int SkiaGLRenderEngine::getContextPriority() {
     int value;
     eglQueryContext(mEGLDisplay, mEGLContext, EGL_CONTEXT_PRIORITY_LEVEL_IMG, &value);
@@ -1281,6 +1277,12 @@
         StringAppendF(&result, "Skia's Wrapped Objects:\n");
         gpuReporter.logOutput(result, true);
 
+        StringAppendF(&result, "RenderEngine tracked buffers: %zu\n",
+                      mGraphicBufferExternalRefs.size());
+        StringAppendF(&result, "Dumping buffer ids...\n");
+        for (const auto& [id, refCounts] : mGraphicBufferExternalRefs) {
+            StringAppendF(&result, "- 0x%" PRIx64 " - %d refs \n", id, refCounts);
+        }
         StringAppendF(&result, "RenderEngine AHB/BackendTexture cache size: %zu\n",
                       mTextureCache.size());
         StringAppendF(&result, "Dumping buffer ids...\n");
diff --git a/libs/renderengine/skia/SkiaGLRenderEngine.h b/libs/renderengine/skia/SkiaGLRenderEngine.h
index 8e77c16..e71c560 100644
--- a/libs/renderengine/skia/SkiaGLRenderEngine.h
+++ b/libs/renderengine/skia/SkiaGLRenderEngine.h
@@ -23,6 +23,7 @@
 #include <GrDirectContext.h>
 #include <SkSurface.h>
 #include <android-base/thread_annotations.h>
+#include <renderengine/ExternalTexture.h>
 #include <renderengine/RenderEngine.h>
 #include <sys/types.h>
 
@@ -52,13 +53,12 @@
     ~SkiaGLRenderEngine() override EXCLUDES(mRenderingMutex);
 
     void primeCache() override;
-    void cacheExternalTextureBuffer(const sp<GraphicBuffer>& buffer) override;
-    void unbindExternalTextureBuffer(uint64_t bufferId) override;
     status_t drawLayers(const DisplaySettings& display,
                         const std::vector<const LayerSettings*>& layers,
-                        const sp<GraphicBuffer>& buffer, const bool useFramebufferCache,
-                        base::unique_fd&& bufferFence, base::unique_fd* drawFence) override;
-    void cleanFramebufferCache() override;
+                        const std::shared_ptr<ExternalTexture>& buffer,
+                        const bool useFramebufferCache, base::unique_fd&& bufferFence,
+                        base::unique_fd* drawFence) override;
+    void cleanFramebufferCache() override {}
     int getContextPriority() override;
     bool isProtected() const override { return mInProtectedContext; }
     bool supportsProtectedContent() const override;
@@ -72,6 +72,8 @@
     void dump(std::string& result) override;
     size_t getMaxTextureSize() const override;
     size_t getMaxViewportDims() const override;
+    void mapExternalTextureBuffer(const sp<GraphicBuffer>& buffer, bool isRenderable) override;
+    void unmapExternalTextureBuffer(const sp<GraphicBuffer>& buffer) override;
 
 private:
     static EGLConfig chooseEglConfig(EGLDisplay display, int format, bool logConfig);
@@ -114,7 +116,9 @@
     const PixelFormat mDefaultPixelFormat;
     const bool mUseColorManagement;
 
-    // Cache of GL textures that we'll store per GraphicBuffer ID
+    // Number of external holders of ExternalTexture references, per GraphicBuffer ID.
+    std::unordered_map<uint64_t, int32_t> mGraphicBufferExternalRefs GUARDED_BY(mRenderingMutex);
+    // Cache of GL textures that we'll store per GraphicBuffer ID, sliced by GPU context.
     std::unordered_map<uint64_t, std::shared_ptr<AutoBackendTexture::LocalRef>> mTextureCache
             GUARDED_BY(mRenderingMutex);
     std::unordered_map<uint64_t, std::shared_ptr<AutoBackendTexture::LocalRef>>
diff --git a/libs/renderengine/skia/SkiaRenderEngine.h b/libs/renderengine/skia/SkiaRenderEngine.h
index 51ef088..308c5ff 100644
--- a/libs/renderengine/skia/SkiaRenderEngine.h
+++ b/libs/renderengine/skia/SkiaRenderEngine.h
@@ -42,15 +42,12 @@
     virtual void primeCache() override{};
     virtual void genTextures(size_t /*count*/, uint32_t* /*names*/) override{};
     virtual void deleteTextures(size_t /*count*/, uint32_t const* /*names*/) override{};
-    virtual void cacheExternalTextureBuffer(const sp<GraphicBuffer>& /*buffer*/){};
-    virtual void unbindExternalTextureBuffer(uint64_t /*bufferId*/){};
-
     virtual bool isProtected() const override { return false; } // mInProtectedContext; }
     virtual bool supportsProtectedContent() const override { return false; };
     virtual bool useProtectedContext(bool /*useProtectedContext*/) override { return false; };
     virtual status_t drawLayers(const DisplaySettings& /*display*/,
                                 const std::vector<const LayerSettings*>& /*layers*/,
-                                const sp<GraphicBuffer>& /*buffer*/,
+                                const std::shared_ptr<ExternalTexture>& /*buffer*/,
                                 const bool /*useFramebufferCache*/,
                                 base::unique_fd&& /*bufferFence*/,
                                 base::unique_fd* /*drawFence*/) override {
@@ -60,6 +57,11 @@
     virtual int getContextPriority() override { return 0; }
     virtual void assertShadersCompiled(int numShaders) {}
     virtual int reportShadersCompiled() { return 0; }
+
+protected:
+    virtual void mapExternalTextureBuffer(const sp<GraphicBuffer>& /*buffer*/,
+                                          bool /*isRenderable*/) override;
+    virtual void unmapExternalTextureBuffer(const sp<GraphicBuffer>& /*buffer*/) override;
 };
 
 } // namespace skia