Skip client composition requests

Keep track of client compositions requests in CompositionEngine and
the buffer used to render the request. If the requests do not change
and the buffer matches, reuse the buffer instead of going
to client composition.

Certain layers properties (buffer format, rounded corner or shadows)
will force the device to go into GPU or mixed composition. In mixed
composition scenarios, we can avoid redundant client composition
requests by reusing the RenderSurface buffers. If the device goes
into GPU composition then all the layers will be composited and there
will be no performance benefit.

Bug: b/136561771, b/144690120

Test: dump SurfaceFlinger --timestats -dump
Test: manual testing with mixed and gpu composition scenarios
Test: atest libcompositionengine_test libsurfaceflinger_unittest SurfaceFlinger_test
Change-Id: I466d5dcded0c9fcfa64bc72fd91dfaddd795f315
diff --git a/libs/renderengine/gl/GLESRenderEngine.cpp b/libs/renderengine/gl/GLESRenderEngine.cpp
index 09659fe..e257704 100644
--- a/libs/renderengine/gl/GLESRenderEngine.cpp
+++ b/libs/renderengine/gl/GLESRenderEngine.cpp
@@ -960,7 +960,7 @@
 }
 
 status_t GLESRenderEngine::drawLayers(const DisplaySettings& display,
-                                      const std::vector<LayerSettings>& layers,
+                                      const std::vector<const LayerSettings*>& layers,
                                       ANativeWindowBuffer* const buffer,
                                       const bool useFramebufferCache, base::unique_fd&& bufferFence,
                                       base::unique_fd* drawFence) {
@@ -985,9 +985,9 @@
     // Blurs in multiple layers are not supported, given the cost of the shader.
     const LayerSettings* blurLayer = nullptr;
     if (CC_LIKELY(mBlurFilter != nullptr)) {
-        for (auto const& layer : layers) {
-            if (layer.backgroundBlurRadius > 0) {
-                blurLayer = &layer;
+        for (auto const layer : layers) {
+            if (layer->backgroundBlurRadius > 0) {
+                blurLayer = layer;
             }
         }
     }
@@ -1035,9 +1035,9 @@
                         .setTexCoords(2 /* size */)
                         .setCropCoords(2 /* size */)
                         .build();
-    for (auto const& layer : layers) {
-        if (blurLayer == &layer) {
-            auto status = mBlurFilter->prepare(layer.backgroundBlurRadius);
+    for (auto const layer : layers) {
+        if (blurLayer == layer) {
+            auto status = mBlurFilter->prepare(layer->backgroundBlurRadius);
             if (status != NO_ERROR) {
                 ALOGE("Failed to render blur effect! Aborting GPU composition for buffer (%p).",
                       buffer->handle);
@@ -1065,40 +1065,40 @@
             }
         }
 
-        mState.maxMasteringLuminance = layer.source.buffer.maxMasteringLuminance;
-        mState.maxContentLuminance = layer.source.buffer.maxContentLuminance;
-        mState.projectionMatrix = projectionMatrix * layer.geometry.positionTransform;
+        mState.maxMasteringLuminance = layer->source.buffer.maxMasteringLuminance;
+        mState.maxContentLuminance = layer->source.buffer.maxContentLuminance;
+        mState.projectionMatrix = projectionMatrix * layer->geometry.positionTransform;
 
-        const FloatRect bounds = layer.geometry.boundaries;
+        const FloatRect bounds = layer->geometry.boundaries;
         Mesh::VertexArray<vec2> position(mesh.getPositionArray<vec2>());
         position[0] = vec2(bounds.left, bounds.top);
         position[1] = vec2(bounds.left, bounds.bottom);
         position[2] = vec2(bounds.right, bounds.bottom);
         position[3] = vec2(bounds.right, bounds.top);
 
-        setupLayerCropping(layer, mesh);
-        setColorTransform(display.colorTransform * layer.colorTransform);
+        setupLayerCropping(*layer, mesh);
+        setColorTransform(display.colorTransform * layer->colorTransform);
 
         bool usePremultipliedAlpha = true;
         bool disableTexture = true;
         bool isOpaque = false;
-        if (layer.source.buffer.buffer != nullptr) {
+        if (layer->source.buffer.buffer != nullptr) {
             disableTexture = false;
-            isOpaque = layer.source.buffer.isOpaque;
+            isOpaque = layer->source.buffer.isOpaque;
 
-            sp<GraphicBuffer> gBuf = layer.source.buffer.buffer;
-            bindExternalTextureBuffer(layer.source.buffer.textureName, gBuf,
-                                      layer.source.buffer.fence);
+            sp<GraphicBuffer> gBuf = layer->source.buffer.buffer;
+            bindExternalTextureBuffer(layer->source.buffer.textureName, gBuf,
+                                      layer->source.buffer.fence);
 
-            usePremultipliedAlpha = layer.source.buffer.usePremultipliedAlpha;
-            Texture texture(Texture::TEXTURE_EXTERNAL, layer.source.buffer.textureName);
-            mat4 texMatrix = layer.source.buffer.textureTransform;
+            usePremultipliedAlpha = layer->source.buffer.usePremultipliedAlpha;
+            Texture texture(Texture::TEXTURE_EXTERNAL, layer->source.buffer.textureName);
+            mat4 texMatrix = layer->source.buffer.textureTransform;
 
             texture.setMatrix(texMatrix.asArray());
-            texture.setFiltering(layer.source.buffer.useTextureFiltering);
+            texture.setFiltering(layer->source.buffer.useTextureFiltering);
 
             texture.setDimensions(gBuf->getWidth(), gBuf->getHeight());
-            setSourceY410BT2020(layer.source.buffer.isY410BT2020);
+            setSourceY410BT2020(layer->source.buffer.isY410BT2020);
 
             renderengine::Mesh::VertexArray<vec2> texCoords(mesh.getTexCoordArray<vec2>());
             texCoords[0] = vec2(0.0, 0.0);
@@ -1108,32 +1108,32 @@
             setupLayerTexturing(texture);
         }
 
-        const half3 solidColor = layer.source.solidColor;
-        const half4 color = half4(solidColor.r, solidColor.g, solidColor.b, layer.alpha);
+        const half3 solidColor = layer->source.solidColor;
+        const half4 color = half4(solidColor.r, solidColor.g, solidColor.b, layer->alpha);
         // Buffer sources will have a black solid color ignored in the shader,
         // so in that scenario the solid color passed here is arbitrary.
         setupLayerBlending(usePremultipliedAlpha, isOpaque, disableTexture, color,
-                           layer.geometry.roundedCornersRadius);
-        if (layer.disableBlending) {
+                           layer->geometry.roundedCornersRadius);
+        if (layer->disableBlending) {
             glDisable(GL_BLEND);
         }
-        setSourceDataSpace(layer.sourceDataspace);
+        setSourceDataSpace(layer->sourceDataspace);
 
-        if (layer.shadow.length > 0.0f) {
-            handleShadow(layer.geometry.boundaries, layer.geometry.roundedCornersRadius,
-                         layer.shadow);
+        if (layer->shadow.length > 0.0f) {
+            handleShadow(layer->geometry.boundaries, layer->geometry.roundedCornersRadius,
+                         layer->shadow);
         }
         // We only want to do a special handling for rounded corners when having rounded corners
         // is the only reason it needs to turn on blending, otherwise, we handle it like the
         // usual way since it needs to turn on blending anyway.
-        else if (layer.geometry.roundedCornersRadius > 0.0 && color.a >= 1.0f && isOpaque) {
-            handleRoundedCorners(display, layer, mesh);
+        else if (layer->geometry.roundedCornersRadius > 0.0 && color.a >= 1.0f && isOpaque) {
+            handleRoundedCorners(display, *layer, mesh);
         } else {
             drawMesh(mesh);
         }
 
         // Cleanup if there's a buffer source
-        if (layer.source.buffer.buffer != nullptr) {
+        if (layer->source.buffer.buffer != nullptr) {
             disableBlending();
             setSourceY410BT2020(false);
             disableTexturing();
diff --git a/libs/renderengine/gl/GLESRenderEngine.h b/libs/renderengine/gl/GLESRenderEngine.h
index 547235a..45c85de 100644
--- a/libs/renderengine/gl/GLESRenderEngine.h
+++ b/libs/renderengine/gl/GLESRenderEngine.h
@@ -71,7 +71,8 @@
     bool isProtected() const override { return mInProtectedContext; }
     bool supportsProtectedContent() const override;
     bool useProtectedContext(bool useProtectedContext) override;
-    status_t drawLayers(const DisplaySettings& display, const std::vector<LayerSettings>& layers,
+    status_t drawLayers(const DisplaySettings& display,
+                        const std::vector<const LayerSettings*>& layers,
                         ANativeWindowBuffer* buffer, const bool useFramebufferCache,
                         base::unique_fd&& bufferFence, base::unique_fd* drawFence) override;
 
diff --git a/libs/renderengine/include/renderengine/LayerSettings.h b/libs/renderengine/include/renderengine/LayerSettings.h
index 3dc198f..95e9367 100644
--- a/libs/renderengine/include/renderengine/LayerSettings.h
+++ b/libs/renderengine/include/renderengine/LayerSettings.h
@@ -52,7 +52,7 @@
     // Transform matrix to apply to texture coordinates.
     mat4 textureTransform = mat4();
 
-    // Wheteher to use pre-multiplied alpha
+    // Whether to use pre-multiplied alpha.
     bool usePremultipliedAlpha = true;
 
     // Override flag that alpha for each pixel in the buffer *must* be 1.0.
@@ -153,6 +153,8 @@
     int backgroundBlurRadius = 0;
 };
 
+// Keep in sync with custom comparison function in
+// compositionengine/impl/ClientCompositionRequestCache.cpp
 static inline bool operator==(const Buffer& lhs, const Buffer& rhs) {
     return lhs.buffer == rhs.buffer && lhs.fence == rhs.fence &&
             lhs.textureName == rhs.textureName &&
diff --git a/libs/renderengine/include/renderengine/RenderEngine.h b/libs/renderengine/include/renderengine/RenderEngine.h
index e3c2d84..46f3fc6 100644
--- a/libs/renderengine/include/renderengine/RenderEngine.h
+++ b/libs/renderengine/include/renderengine/RenderEngine.h
@@ -154,7 +154,7 @@
     // @return An error code indicating whether drawing was successful. For
     // now, this always returns NO_ERROR.
     virtual status_t drawLayers(const DisplaySettings& display,
-                                const std::vector<LayerSettings>& layers,
+                                const std::vector<const LayerSettings*>& layers,
                                 ANativeWindowBuffer* buffer, const bool useFramebufferCache,
                                 base::unique_fd&& bufferFence, base::unique_fd* drawFence) = 0;
 
diff --git a/libs/renderengine/include/renderengine/mock/RenderEngine.h b/libs/renderengine/include/renderengine/mock/RenderEngine.h
index 0750e86..3358c69 100644
--- a/libs/renderengine/include/renderengine/mock/RenderEngine.h
+++ b/libs/renderengine/include/renderengine/mock/RenderEngine.h
@@ -56,7 +56,7 @@
     MOCK_CONST_METHOD0(supportsProtectedContent, bool());
     MOCK_METHOD1(useProtectedContext, bool(bool));
     MOCK_METHOD6(drawLayers,
-                 status_t(const DisplaySettings&, const std::vector<LayerSettings>&,
+                 status_t(const DisplaySettings&, const std::vector<const LayerSettings*>&,
                           ANativeWindowBuffer*, const bool, base::unique_fd&&, base::unique_fd*));
 };
 
diff --git a/libs/renderengine/tests/RenderEngineTest.cpp b/libs/renderengine/tests/RenderEngineTest.cpp
index e676740..afcbc50 100644
--- a/libs/renderengine/tests/RenderEngineTest.cpp
+++ b/libs/renderengine/tests/RenderEngineTest.cpp
@@ -249,7 +249,8 @@
     }
 
     void invokeDraw(renderengine::DisplaySettings settings,
-                    std::vector<renderengine::LayerSettings> layers, sp<GraphicBuffer> buffer) {
+                    std::vector<const renderengine::LayerSettings*> layers,
+                    sp<GraphicBuffer> buffer) {
         base::unique_fd fence;
         status_t status = sRE->drawLayers(settings, layers, buffer->getNativeBuffer(), true,
                                           base::unique_fd(), &fence);
@@ -269,7 +270,7 @@
 
     void drawEmptyLayers() {
         renderengine::DisplaySettings settings;
-        std::vector<renderengine::LayerSettings> layers;
+        std::vector<const renderengine::LayerSettings*> layers;
         // Meaningless buffer since we don't do any drawing
         sp<GraphicBuffer> buffer = new GraphicBuffer();
         invokeDraw(settings, layers, buffer);
@@ -440,14 +441,14 @@
     settings.physicalDisplay = fullscreenRect();
     settings.clip = fullscreenRect();
 
-    std::vector<renderengine::LayerSettings> layers;
+    std::vector<const renderengine::LayerSettings*> layers;
 
     renderengine::LayerSettings layer;
     layer.geometry.boundaries = fullscreenRect().toFloatRect();
     SourceVariant::fillColor(layer, r, g, b, this);
     layer.alpha = a;
 
-    layers.push_back(layer);
+    layers.push_back(&layer);
 
     invokeDraw(settings, layers, mBuffer);
 }
@@ -482,14 +483,14 @@
     settings.physicalDisplay = offsetRect();
     settings.clip = offsetRectAtZero();
 
-    std::vector<renderengine::LayerSettings> layers;
+    std::vector<const renderengine::LayerSettings*> layers;
 
     renderengine::LayerSettings layer;
     layer.geometry.boundaries = offsetRectAtZero().toFloatRect();
     SourceVariant::fillColor(layer, 1.0f, 0.0f, 0.0f, this);
     layer.alpha = 1.0f;
 
-    layers.push_back(layer);
+    layers.push_back(&layer);
     invokeDraw(settings, layers, mBuffer);
 }
 
@@ -515,7 +516,7 @@
     settings.clip = Rect(2, 2);
     settings.globalTransform = transform;
 
-    std::vector<renderengine::LayerSettings> layers;
+    std::vector<const renderengine::LayerSettings*> layers;
 
     renderengine::LayerSettings layerOne;
     Rect rectOne(0, 0, 1, 1);
@@ -535,9 +536,9 @@
     SourceVariant::fillColor(layerThree, 0.0f, 0.0f, 1.0f, this);
     layerThree.alpha = 1.0f;
 
-    layers.push_back(layerOne);
-    layers.push_back(layerTwo);
-    layers.push_back(layerThree);
+    layers.push_back(&layerOne);
+    layers.push_back(&layerTwo);
+    layers.push_back(&layerThree);
 
     invokeDraw(settings, layers, mBuffer);
 }
@@ -616,7 +617,7 @@
     // Here logical space is 2x2
     settings.clip = Rect(2, 2);
 
-    std::vector<renderengine::LayerSettings> layers;
+    std::vector<const renderengine::LayerSettings*> layers;
 
     renderengine::LayerSettings layer;
     layer.geometry.boundaries = Rect(1, 1).toFloatRect();
@@ -626,7 +627,7 @@
     layer.source.solidColor = half3(1.0f, 0.0f, 0.0f);
     layer.alpha = 1.0f;
 
-    layers.push_back(layer);
+    layers.push_back(&layer);
 
     invokeDraw(settings, layers, mBuffer);
 }
@@ -647,7 +648,7 @@
     settings.physicalDisplay = fullscreenRect();
     settings.clip = Rect(1, 1);
 
-    std::vector<renderengine::LayerSettings> layers;
+    std::vector<const renderengine::LayerSettings*> layers;
 
     renderengine::LayerSettings layer;
     layer.geometry.boundaries = Rect(1, 1).toFloatRect();
@@ -663,7 +664,7 @@
     layer.alpha = 1.0f;
     layer.geometry.boundaries = Rect(1, 1).toFloatRect();
 
-    layers.push_back(layer);
+    layers.push_back(&layer);
 
     invokeDraw(settings, layers, mBuffer);
 }
@@ -680,7 +681,7 @@
     settings.physicalDisplay = fullscreenRect();
     settings.clip = fullscreenRect();
 
-    std::vector<renderengine::LayerSettings> layers;
+    std::vector<const renderengine::LayerSettings*> layers;
 
     renderengine::LayerSettings layer;
     layer.geometry.boundaries = fullscreenRect().toFloatRect();
@@ -689,7 +690,7 @@
     SourceVariant::fillColor(layer, 1.0f, 0.0f, 0.0f, this);
     layer.alpha = 1.0f;
 
-    layers.push_back(layer);
+    layers.push_back(&layer);
 
     invokeDraw(settings, layers, mBuffer);
 }
@@ -726,26 +727,26 @@
     settings.physicalDisplay = fullscreenRect();
     settings.clip = fullscreenRect();
 
-    std::vector<renderengine::LayerSettings> layers;
+    std::vector<const renderengine::LayerSettings*> layers;
 
     renderengine::LayerSettings backgroundLayer;
     backgroundLayer.geometry.boundaries = fullscreenRect().toFloatRect();
     SourceVariant::fillColor(backgroundLayer, 0.0f, 1.0f, 0.0f, this);
     backgroundLayer.alpha = 1.0f;
-    layers.push_back(backgroundLayer);
+    layers.push_back(&backgroundLayer);
 
     renderengine::LayerSettings leftLayer;
     leftLayer.geometry.boundaries =
             Rect(DEFAULT_DISPLAY_WIDTH / 2, DEFAULT_DISPLAY_HEIGHT).toFloatRect();
     SourceVariant::fillColor(leftLayer, 1.0f, 0.0f, 0.0f, this);
     leftLayer.alpha = 1.0f;
-    layers.push_back(leftLayer);
+    layers.push_back(&leftLayer);
 
     renderengine::LayerSettings blurLayer;
     blurLayer.geometry.boundaries = fullscreenRect().toFloatRect();
     blurLayer.backgroundBlurRadius = blurRadius;
     blurLayer.alpha = 0;
-    layers.push_back(blurLayer);
+    layers.push_back(&blurLayer);
 
     invokeDraw(settings, layers, mBuffer);
 
@@ -761,7 +762,7 @@
     settings.physicalDisplay = fullscreenRect();
     settings.clip = fullscreenRect();
 
-    std::vector<renderengine::LayerSettings> layersFirst;
+    std::vector<const renderengine::LayerSettings*> layersFirst;
 
     renderengine::LayerSettings layerOne;
     layerOne.geometry.boundaries =
@@ -769,14 +770,14 @@
     SourceVariant::fillColor(layerOne, 1.0f, 0.0f, 0.0f, this);
     layerOne.alpha = 0.2;
 
-    layersFirst.push_back(layerOne);
+    layersFirst.push_back(&layerOne);
     invokeDraw(settings, layersFirst, mBuffer);
     expectBufferColor(Rect(DEFAULT_DISPLAY_WIDTH / 3, DEFAULT_DISPLAY_HEIGHT / 3), 51, 0, 0, 51);
     expectBufferColor(Rect(DEFAULT_DISPLAY_WIDTH / 3 + 1, DEFAULT_DISPLAY_HEIGHT / 3 + 1,
                            DEFAULT_DISPLAY_WIDTH, DEFAULT_DISPLAY_HEIGHT),
                       0, 0, 0, 0);
 
-    std::vector<renderengine::LayerSettings> layersSecond;
+    std::vector<const renderengine::LayerSettings*> layersSecond;
     renderengine::LayerSettings layerTwo;
     layerTwo.geometry.boundaries =
             FloatRect(DEFAULT_DISPLAY_WIDTH / 3.0, DEFAULT_DISPLAY_HEIGHT / 3.0,
@@ -784,7 +785,7 @@
     SourceVariant::fillColor(layerTwo, 0.0f, 1.0f, 0.0f, this);
     layerTwo.alpha = 1.0f;
 
-    layersSecond.push_back(layerTwo);
+    layersSecond.push_back(&layerTwo);
     invokeDraw(settings, layersSecond, mBuffer);
 
     expectBufferColor(Rect(DEFAULT_DISPLAY_WIDTH / 3, DEFAULT_DISPLAY_HEIGHT / 3), 0, 0, 0, 0);
@@ -798,7 +799,7 @@
     settings.physicalDisplay = fullscreenRect();
     settings.clip = Rect(1, 1);
 
-    std::vector<renderengine::LayerSettings> layers;
+    std::vector<const renderengine::LayerSettings*> layers;
 
     renderengine::LayerSettings layer;
     // Here will allocate a checker board texture, but transform texture
@@ -833,7 +834,7 @@
     layer.alpha = 1.0f;
     layer.geometry.boundaries = Rect(1, 1).toFloatRect();
 
-    layers.push_back(layer);
+    layers.push_back(&layer);
 
     invokeDraw(settings, layers, mBuffer);
 }
@@ -849,7 +850,7 @@
     // Here logical space is 1x1
     settings.clip = Rect(1, 1);
 
-    std::vector<renderengine::LayerSettings> layers;
+    std::vector<const renderengine::LayerSettings*> layers;
 
     renderengine::LayerSettings layer;
     sp<GraphicBuffer> buf = allocateSourceBuffer(1, 1);
@@ -872,7 +873,7 @@
     layer.alpha = 0.5f;
     layer.geometry.boundaries = Rect(1, 1).toFloatRect();
 
-    layers.push_back(layer);
+    layers.push_back(&layer);
 
     invokeDraw(settings, layers, mBuffer);
 }
@@ -888,7 +889,7 @@
     // Here logical space is 1x1
     settings.clip = Rect(1, 1);
 
-    std::vector<renderengine::LayerSettings> layers;
+    std::vector<const renderengine::LayerSettings*> layers;
 
     renderengine::LayerSettings layer;
     sp<GraphicBuffer> buf = allocateSourceBuffer(1, 1);
@@ -911,7 +912,7 @@
     layer.alpha = 0.5f;
     layer.geometry.boundaries = Rect(1, 1).toFloatRect();
 
-    layers.push_back(layer);
+    layers.push_back(&layer);
 
     invokeDraw(settings, layers, mBuffer);
 }
@@ -928,10 +929,10 @@
     settings.clip = Rect(4, 4);
     settings.globalTransform = mat4::scale(vec4(2, 4, 0, 1));
     settings.clearRegion = Region(Rect(1, 1));
-    std::vector<renderengine::LayerSettings> layers;
+    std::vector<const renderengine::LayerSettings*> layers;
     // dummy layer, without bounds should not render anything
     renderengine::LayerSettings layer;
-    layers.push_back(layer);
+    layers.push_back(&layer);
     invokeDraw(settings, layers, mBuffer);
 }
 
@@ -952,7 +953,7 @@
     settings.physicalDisplay = fullscreenRect();
     settings.clip = fullscreenRect();
 
-    std::vector<renderengine::LayerSettings> layers;
+    std::vector<const renderengine::LayerSettings*> layers;
 
     // add background layer
     renderengine::LayerSettings bgLayer;
@@ -960,20 +961,20 @@
     ColorSourceVariant::fillColor(bgLayer, backgroundColor.r / 255.0f, backgroundColor.g / 255.0f,
                                   backgroundColor.b / 255.0f, this);
     bgLayer.alpha = backgroundColor.a / 255.0f;
-    layers.push_back(bgLayer);
+    layers.push_back(&bgLayer);
 
     // add shadow layer
     renderengine::LayerSettings shadowLayer;
     shadowLayer.geometry.boundaries = castingLayer.geometry.boundaries;
     shadowLayer.alpha = castingLayer.alpha;
     shadowLayer.shadow = shadow;
-    layers.push_back(shadowLayer);
+    layers.push_back(&shadowLayer);
 
     // add layer casting the shadow
     renderengine::LayerSettings layer = castingLayer;
     SourceVariant::fillColor(layer, casterColor.r / 255.0f, casterColor.g / 255.0f,
                              casterColor.b / 255.0f, this);
-    layers.push_back(layer);
+    layers.push_back(&layer);
 
     invokeDraw(settings, layers, mBuffer);
 }
@@ -984,11 +985,11 @@
 
 TEST_F(RenderEngineTest, drawLayers_nullOutputBuffer) {
     renderengine::DisplaySettings settings;
-    std::vector<renderengine::LayerSettings> layers;
+    std::vector<const renderengine::LayerSettings*> layers;
     renderengine::LayerSettings layer;
     layer.geometry.boundaries = fullscreenRect().toFloatRect();
     BufferSourceVariant<ForceOpaqueBufferVariant>::fillColor(layer, 1.0f, 0.0f, 0.0f, this);
-    layers.push_back(layer);
+    layers.push_back(&layer);
     base::unique_fd fence;
     status_t status = sRE->drawLayers(settings, layers, nullptr, true, base::unique_fd(), &fence);
 
@@ -1000,12 +1001,12 @@
     settings.physicalDisplay = fullscreenRect();
     settings.clip = fullscreenRect();
 
-    std::vector<renderengine::LayerSettings> layers;
+    std::vector<const renderengine::LayerSettings*> layers;
     renderengine::LayerSettings layer;
     layer.geometry.boundaries = fullscreenRect().toFloatRect();
     BufferSourceVariant<ForceOpaqueBufferVariant>::fillColor(layer, 1.0f, 0.0f, 0.0f, this);
     layer.alpha = 1.0;
-    layers.push_back(layer);
+    layers.push_back(&layer);
 
     status_t status = sRE->drawLayers(settings, layers, mBuffer->getNativeBuffer(), true,
                                       base::unique_fd(), nullptr);
@@ -1019,12 +1020,12 @@
     settings.physicalDisplay = fullscreenRect();
     settings.clip = fullscreenRect();
 
-    std::vector<renderengine::LayerSettings> layers;
+    std::vector<const renderengine::LayerSettings*> layers;
     renderengine::LayerSettings layer;
     layer.geometry.boundaries = fullscreenRect().toFloatRect();
     BufferSourceVariant<ForceOpaqueBufferVariant>::fillColor(layer, 1.0f, 0.0f, 0.0f, this);
     layer.alpha = 1.0;
-    layers.push_back(layer);
+    layers.push_back(&layer);
 
     status_t status = sRE->drawLayers(settings, layers, mBuffer->getNativeBuffer(), false,
                                       base::unique_fd(), nullptr);
@@ -1223,13 +1224,13 @@
     settings.physicalDisplay = fullscreenRect();
     settings.clip = fullscreenRect();
 
-    std::vector<renderengine::LayerSettings> layers;
+    std::vector<const renderengine::LayerSettings*> layers;
 
     renderengine::LayerSettings layer;
     layer.geometry.boundaries = fullscreenRect().toFloatRect();
     BufferSourceVariant<ForceOpaqueBufferVariant>::fillColor(layer, 1.0f, 0.0f, 0.0f, this);
 
-    layers.push_back(layer);
+    layers.push_back(&layer);
     invokeDraw(settings, layers, mBuffer);
     uint64_t bufferId = layer.source.buffer.buffer->getId();
     EXPECT_TRUE(sRE->isImageCachedForTesting(bufferId));
diff --git a/services/surfaceflinger/BufferLayer.cpp b/services/surfaceflinger/BufferLayer.cpp
index 7845cab..35d0215 100644
--- a/services/surfaceflinger/BufferLayer.cpp
+++ b/services/surfaceflinger/BufferLayer.cpp
@@ -144,11 +144,12 @@
     return inverse(tr);
 }
 
-std::optional<renderengine::LayerSettings> BufferLayer::prepareClientComposition(
+std::optional<compositionengine::LayerFE::LayerSettings> BufferLayer::prepareClientComposition(
         compositionengine::LayerFE::ClientCompositionTargetSettings& targetSettings) {
     ATRACE_CALL();
 
-    auto result = Layer::prepareClientComposition(targetSettings);
+    std::optional<compositionengine::LayerFE::LayerSettings> result =
+            Layer::prepareClientComposition(targetSettings);
     if (!result) {
         return result;
     }
@@ -183,7 +184,7 @@
     bool blackOutLayer = (isProtected() && !targetSettings.supportsProtectedContent) ||
             (isSecure() && !targetSettings.isSecure);
     const State& s(getDrawingState());
-    auto& layer = *result;
+    LayerFE::LayerSettings& layer = *result;
     if (!blackOutLayer) {
         layer.source.buffer.buffer = mBufferInfo.mBuffer;
         layer.source.buffer.isOpaque = isOpaque(s);
@@ -199,6 +200,9 @@
         layer.source.buffer.maxContentLuminance = hasCta861_3
                 ? mBufferInfo.mHdrMetadata.cta8613.maxContentLightLevel
                 : defaultMaxContentLuminance;
+        layer.frameNumber = mCurrentFrameNumber;
+        layer.bufferId = mBufferInfo.mBuffer ? mBufferInfo.mBuffer->getId() : 0;
+
         // TODO: we could be more subtle with isFixedSize()
         const bool useFiltering = targetSettings.needsFiltering || mNeedsFiltering || isFixedSize();
 
@@ -264,9 +268,11 @@
         // layer.
         layer.source.buffer.buffer = nullptr;
         layer.alpha = 1.0;
+        layer.frameNumber = 0;
+        layer.bufferId = 0;
     }
 
-    return result;
+    return layer;
 }
 
 bool BufferLayer::isHdrY410() const {
diff --git a/services/surfaceflinger/BufferLayer.h b/services/surfaceflinger/BufferLayer.h
index 5f5532e..b2398a8 100644
--- a/services/surfaceflinger/BufferLayer.h
+++ b/services/surfaceflinger/BufferLayer.h
@@ -177,7 +177,7 @@
      */
     bool onPreComposition(nsecs_t) override;
     void latchPerFrameState(compositionengine::LayerFECompositionState&) const override;
-    std::optional<renderengine::LayerSettings> prepareClientComposition(
+    std::optional<compositionengine::LayerFE::LayerSettings> prepareClientComposition(
             compositionengine::LayerFE::ClientCompositionTargetSettings&) override;
 
     // Loads the corresponding system property once per process
diff --git a/services/surfaceflinger/ColorLayer.cpp b/services/surfaceflinger/ColorLayer.cpp
index 6aea88a..04854d0 100644
--- a/services/surfaceflinger/ColorLayer.cpp
+++ b/services/surfaceflinger/ColorLayer.cpp
@@ -50,7 +50,7 @@
 
 ColorLayer::~ColorLayer() = default;
 
-std::optional<renderengine::LayerSettings> ColorLayer::prepareClientComposition(
+std::optional<compositionengine::LayerFE::LayerSettings> ColorLayer::prepareClientComposition(
         compositionengine::LayerFE::ClientCompositionTargetSettings& targetSettings) {
     auto result = Layer::prepareClientComposition(targetSettings);
     if (!result) {
diff --git a/services/surfaceflinger/ColorLayer.h b/services/surfaceflinger/ColorLayer.h
index 634a800..9246eb2 100644
--- a/services/surfaceflinger/ColorLayer.h
+++ b/services/surfaceflinger/ColorLayer.h
@@ -46,7 +46,7 @@
      * compositionengine::LayerFE overrides
      */
     void latchPerFrameState(compositionengine::LayerFECompositionState&) const override;
-    std::optional<renderengine::LayerSettings> prepareClientComposition(
+    std::optional<compositionengine::LayerFE::LayerSettings> prepareClientComposition(
             compositionengine::LayerFE::ClientCompositionTargetSettings&) override;
 
     std::shared_ptr<compositionengine::Layer> mCompositionLayer;
diff --git a/services/surfaceflinger/CompositionEngine/Android.bp b/services/surfaceflinger/CompositionEngine/Android.bp
index 42d9875..a634f2f 100644
--- a/services/surfaceflinger/CompositionEngine/Android.bp
+++ b/services/surfaceflinger/CompositionEngine/Android.bp
@@ -44,6 +44,7 @@
     name: "libcompositionengine",
     defaults: ["libcompositionengine_defaults"],
     srcs: [
+        "src/ClientCompositionRequestCache.cpp",
         "src/CompositionEngine.cpp",
         "src/Display.cpp",
         "src/DisplayColorProfile.cpp",
diff --git a/services/surfaceflinger/CompositionEngine/include/compositionengine/Display.h b/services/surfaceflinger/CompositionEngine/include/compositionengine/Display.h
index 9193dc0..a38d1f3 100644
--- a/services/surfaceflinger/CompositionEngine/include/compositionengine/Display.h
+++ b/services/surfaceflinger/CompositionEngine/include/compositionengine/Display.h
@@ -52,6 +52,10 @@
     // Creates a render surface for the display
     virtual void createRenderSurface(const RenderSurfaceCreationArgs&) = 0;
 
+    // Creates a cache to cache duplicate client composition requests and skip
+    // similar requests if needed.
+    virtual void createClientCompositionCache(uint32_t cacheSize) = 0;
+
 protected:
     ~Display() = default;
 };
diff --git a/services/surfaceflinger/CompositionEngine/include/compositionengine/LayerFE.h b/services/surfaceflinger/CompositionEngine/include/compositionengine/LayerFE.h
index e432b1c..f34509f 100644
--- a/services/surfaceflinger/CompositionEngine/include/compositionengine/LayerFE.h
+++ b/services/surfaceflinger/CompositionEngine/include/compositionengine/LayerFE.h
@@ -89,16 +89,26 @@
         Region& clearRegion;
     };
 
+    // A superset of LayerSettings required by RenderEngine to compose a layer
+    // and buffer info to determine duplicate client composition requests.
+    struct LayerSettings : renderengine::LayerSettings {
+        // Currently latched buffer if, 0 if invalid.
+        uint64_t bufferId = 0;
+
+        // Currently latched frame number, 0 if invalid.
+        uint64_t frameNumber = 0;
+    };
+
     // Returns the LayerSettings to pass to RenderEngine::drawLayers, or
     // nullopt_t if the layer does not render
-    virtual std::optional<renderengine::LayerSettings> prepareClientComposition(
+    virtual std::optional<LayerSettings> prepareClientComposition(
             ClientCompositionTargetSettings&) = 0;
 
     // Returns the LayerSettings used to draw shadows around a layer. It is passed
     // to RenderEngine::drawLayers. Returns nullopt_t if the layer does not render
     // shadows.
-    virtual std::optional<renderengine::LayerSettings> prepareShadowClientComposition(
-            const renderengine::LayerSettings& layerSettings, const Rect& displayViewport,
+    virtual std::optional<LayerSettings> prepareShadowClientComposition(
+            const LayerSettings& layerSettings, const Rect& displayViewport,
             ui::Dataspace outputDataspace) = 0;
 
     // Called after the layer is displayed to update the presentation fence
@@ -125,6 +135,13 @@
             lhs.clearRegion.hasSameRects(rhs.clearRegion);
 }
 
+static inline bool operator==(const LayerFE::LayerSettings& lhs,
+                              const LayerFE::LayerSettings& rhs) {
+    return static_cast<const renderengine::LayerSettings&>(lhs) ==
+            static_cast<const renderengine::LayerSettings&>(rhs) &&
+            lhs.bufferId == rhs.bufferId && lhs.frameNumber == rhs.frameNumber;
+}
+
 // Defining PrintTo helps with Google Tests.
 static inline void PrintTo(const LayerFE::ClientCompositionTargetSettings& settings,
                            ::std::ostream* os) {
@@ -140,5 +157,13 @@
     *os << "\n}";
 }
 
+static inline void PrintTo(const LayerFE::LayerSettings& settings, ::std::ostream* os) {
+    *os << "LayerFE::LayerSettings{";
+    PrintTo(static_cast<const renderengine::LayerSettings&>(settings), os);
+    *os << "\n    .bufferId = " << settings.bufferId;
+    *os << "\n    .frameNumber = " << settings.frameNumber;
+    *os << "\n}";
+}
+
 } // namespace compositionengine
 } // namespace android
diff --git a/services/surfaceflinger/CompositionEngine/include/compositionengine/Output.h b/services/surfaceflinger/CompositionEngine/include/compositionengine/Output.h
index 076fdad..7a10c04 100644
--- a/services/surfaceflinger/CompositionEngine/include/compositionengine/Output.h
+++ b/services/surfaceflinger/CompositionEngine/include/compositionengine/Output.h
@@ -271,12 +271,13 @@
     virtual void chooseCompositionStrategy() = 0;
     virtual bool getSkipColorTransform() const = 0;
     virtual FrameFences presentAndGetFrameFences() = 0;
-    virtual std::vector<renderengine::LayerSettings> generateClientCompositionRequests(
+    virtual std::vector<LayerFE::LayerSettings> generateClientCompositionRequests(
             bool supportsProtectedContent, Region& clearRegion, ui::Dataspace outputDataspace) = 0;
     virtual void appendRegionFlashRequests(
             const Region& flashRegion,
-            std::vector<renderengine::LayerSettings>& clientCompositionLayers) = 0;
+            std::vector<LayerFE::LayerSettings>& clientCompositionLayers) = 0;
     virtual void setExpensiveRenderingExpected(bool enabled) = 0;
+    virtual void cacheClientCompositionRequests(uint32_t cacheSize) = 0;
 };
 
 } // namespace android::compositionengine
diff --git a/services/surfaceflinger/CompositionEngine/include/compositionengine/impl/ClientCompositionRequestCache.h b/services/surfaceflinger/CompositionEngine/include/compositionengine/impl/ClientCompositionRequestCache.h
new file mode 100644
index 0000000..c14a6e8
--- /dev/null
+++ b/services/surfaceflinger/CompositionEngine/include/compositionengine/impl/ClientCompositionRequestCache.h
@@ -0,0 +1,66 @@
+/*
+ * Copyright (C) 2020 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma once
+
+#include <cstdint>
+#include <deque>
+
+#include <compositionengine/LayerFE.h>
+#include <renderengine/DisplaySettings.h>
+#include <renderengine/LayerSettings.h>
+
+namespace android {
+
+namespace compositionengine::impl {
+
+// The cache is used to skip duplicate client composition requests. We do so by keeping track
+// of every composition request and the buffer that the request is rendered into. During the
+// next composition request, if the request matches what was rendered into the buffer, then
+// we can skip of the request, pass back an empty fence, and let HWC use the previous render
+// result.
+//
+// The cache is a mapping of the RenderSurface buffer id (unique per process) and a snapshot of
+// the composition request. We need to make sure the request, including the order of the
+// layers, do not change from call to call. The snapshot removes strong references to the
+// client buffer id so we don't extend the lifetime of the buffer by storing it in the cache.
+class ClientCompositionRequestCache {
+public:
+    explicit ClientCompositionRequestCache(uint32_t cacheSize) : mMaxCacheSize(cacheSize){};
+    ~ClientCompositionRequestCache() = default;
+    bool exists(uint64_t bufferId, const renderengine::DisplaySettings& display,
+                const std::vector<LayerFE::LayerSettings>& layerSettings) const;
+    void add(uint64_t bufferId, const renderengine::DisplaySettings& display,
+             const std::vector<LayerFE::LayerSettings>& layerSettings);
+    void remove(uint64_t bufferId);
+
+private:
+    uint32_t mMaxCacheSize;
+    struct ClientCompositionRequest {
+        renderengine::DisplaySettings display;
+        std::vector<LayerFE::LayerSettings> layerSettings;
+        ClientCompositionRequest(const renderengine::DisplaySettings& _display,
+                                 const std::vector<LayerFE::LayerSettings>& _layerSettings);
+        bool equals(const renderengine::DisplaySettings& _display,
+                    const std::vector<LayerFE::LayerSettings>& _layerSettings) const;
+    };
+
+    // Cache of requests, keyed by corresponding GraphicBuffer ID.
+    std::deque<std::pair<uint64_t /* bufferId */, ClientCompositionRequest>> mCache;
+};
+
+} // namespace compositionengine::impl
+} // namespace android
diff --git a/services/surfaceflinger/CompositionEngine/include/compositionengine/impl/Display.h b/services/surfaceflinger/CompositionEngine/include/compositionengine/impl/Display.h
index ace876c..39acb37 100644
--- a/services/surfaceflinger/CompositionEngine/include/compositionengine/impl/Display.h
+++ b/services/surfaceflinger/CompositionEngine/include/compositionengine/impl/Display.h
@@ -60,6 +60,7 @@
     void createDisplayColorProfile(
             const compositionengine::DisplayColorProfileCreationArgs&) override;
     void createRenderSurface(const compositionengine::RenderSurfaceCreationArgs&) override;
+    void createClientCompositionCache(uint32_t cacheSize) override;
 
     // Internal helpers used by chooseCompositionStrategy()
     using ChangedTypes = android::HWComposer::DeviceRequestedChanges::ChangedTypes;
diff --git a/services/surfaceflinger/CompositionEngine/include/compositionengine/impl/Output.h b/services/surfaceflinger/CompositionEngine/include/compositionengine/impl/Output.h
index 3a9776d..240aea8 100644
--- a/services/surfaceflinger/CompositionEngine/include/compositionengine/impl/Output.h
+++ b/services/surfaceflinger/CompositionEngine/include/compositionengine/impl/Output.h
@@ -18,8 +18,10 @@
 
 #include <compositionengine/CompositionEngine.h>
 #include <compositionengine/Output.h>
+#include <compositionengine/impl/ClientCompositionRequestCache.h>
 #include <compositionengine/impl/OutputCompositionState.h>
-
+#include <renderengine/DisplaySettings.h>
+#include <renderengine/LayerSettings.h>
 #include <memory>
 #include <utility>
 #include <vector>
@@ -83,6 +85,7 @@
     void finishFrame(const CompositionRefreshArgs&) override;
     std::optional<base::unique_fd> composeSurfaces(const Region&) override;
     void postFramebuffer() override;
+    void cacheClientCompositionRequests(uint32_t) override;
 
     // Testing
     const ReleasedLayers& getReleasedLayersForTest() const;
@@ -96,11 +99,10 @@
     void chooseCompositionStrategy() override;
     bool getSkipColorTransform() const override;
     compositionengine::Output::FrameFences presentAndGetFrameFences() override;
-    std::vector<renderengine::LayerSettings> generateClientCompositionRequests(
+    std::vector<LayerFE::LayerSettings> generateClientCompositionRequests(
             bool supportsProtectedContent, Region& clearRegion,
             ui::Dataspace outputDataspace) override;
-    void appendRegionFlashRequests(const Region&,
-                                   std::vector<renderengine::LayerSettings>&) override;
+    void appendRegionFlashRequests(const Region&, std::vector<LayerFE::LayerSettings>&) override;
     void setExpensiveRenderingExpected(bool enabled) override;
     void dumpBase(std::string&) const;
 
@@ -128,6 +130,7 @@
 
     ReleasedLayers mReleasedLayers;
     OutputLayer* mLayerRequestingBackgroundBlur = nullptr;
+    std::unique_ptr<ClientCompositionRequestCache> mClientCompositionRequestCache;
 };
 
 // This template factory function standardizes the implementation details of the
diff --git a/services/surfaceflinger/CompositionEngine/include/compositionengine/impl/OutputCompositionState.h b/services/surfaceflinger/CompositionEngine/include/compositionengine/impl/OutputCompositionState.h
index 17d3d3f..34dadb5 100644
--- a/services/surfaceflinger/CompositionEngine/include/compositionengine/impl/OutputCompositionState.h
+++ b/services/surfaceflinger/CompositionEngine/include/compositionengine/impl/OutputCompositionState.h
@@ -45,6 +45,9 @@
     // composition
     bool flipClientTarget{false};
 
+    // If true, the current frame reused the buffer from a previous client composition
+    bool reusedClientComposition{false};
+
     // If true, this output displays layers that are internal-only
     bool layerStackInternal{false};
 
diff --git a/services/surfaceflinger/CompositionEngine/include/compositionengine/mock/Display.h b/services/surfaceflinger/CompositionEngine/include/compositionengine/mock/Display.h
index 57f33ae..3a4c70f 100644
--- a/services/surfaceflinger/CompositionEngine/include/compositionengine/mock/Display.h
+++ b/services/surfaceflinger/CompositionEngine/include/compositionengine/mock/Display.h
@@ -40,6 +40,7 @@
 
     MOCK_METHOD1(createDisplayColorProfile, void(const DisplayColorProfileCreationArgs&));
     MOCK_METHOD1(createRenderSurface, void(const RenderSurfaceCreationArgs&));
+    MOCK_METHOD1(createClientCompositionCache, void(uint32_t));
 };
 
 } // namespace android::compositionengine::mock
diff --git a/services/surfaceflinger/CompositionEngine/include/compositionengine/mock/LayerFE.h b/services/surfaceflinger/CompositionEngine/include/compositionengine/mock/LayerFE.h
index 739490f..163e302 100644
--- a/services/surfaceflinger/CompositionEngine/include/compositionengine/mock/LayerFE.h
+++ b/services/surfaceflinger/CompositionEngine/include/compositionengine/mock/LayerFE.h
@@ -36,11 +36,10 @@
                        void(LayerFECompositionState&, compositionengine::LayerFE::StateSubset));
     MOCK_CONST_METHOD1(latchCursorCompositionState, void(LayerFECompositionState&));
     MOCK_METHOD1(prepareClientComposition,
-                 std::optional<renderengine::LayerSettings>(
+                 std::optional<LayerSettings>(
                          compositionengine::LayerFE::ClientCompositionTargetSettings&));
     MOCK_METHOD3(prepareShadowClientComposition,
-                 std::optional<renderengine::LayerSettings>(const renderengine::LayerSettings&,
-                                                            const Rect&, ui::Dataspace));
+                 std::optional<LayerSettings>(const LayerSettings&, const Rect&, ui::Dataspace));
 
     MOCK_METHOD1(onLayerDisplayed, void(const sp<Fence>&));
 
diff --git a/services/surfaceflinger/CompositionEngine/include/compositionengine/mock/Output.h b/services/surfaceflinger/CompositionEngine/include/compositionengine/mock/Output.h
index 7f5bd06..9135765 100644
--- a/services/surfaceflinger/CompositionEngine/include/compositionengine/mock/Output.h
+++ b/services/surfaceflinger/CompositionEngine/include/compositionengine/mock/Output.h
@@ -107,10 +107,11 @@
     MOCK_METHOD0(presentAndGetFrameFences, compositionengine::Output::FrameFences());
 
     MOCK_METHOD3(generateClientCompositionRequests,
-                 std::vector<renderengine::LayerSettings>(bool, Region&, ui::Dataspace));
+                 std::vector<LayerFE::LayerSettings>(bool, Region&, ui::Dataspace));
     MOCK_METHOD2(appendRegionFlashRequests,
-                 void(const Region&, std::vector<renderengine::LayerSettings>&));
+                 void(const Region&, std::vector<LayerFE::LayerSettings>&));
     MOCK_METHOD1(setExpensiveRenderingExpected, void(bool));
+    MOCK_METHOD1(cacheClientCompositionRequests, void(uint32_t));
 };
 
 } // namespace android::compositionengine::mock
diff --git a/services/surfaceflinger/CompositionEngine/src/ClientCompositionRequestCache.cpp b/services/surfaceflinger/CompositionEngine/src/ClientCompositionRequestCache.cpp
new file mode 100644
index 0000000..acaaf4e
--- /dev/null
+++ b/services/surfaceflinger/CompositionEngine/src/ClientCompositionRequestCache.cpp
@@ -0,0 +1,126 @@
+/*
+ * Copyright (C) 2020 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <algorithm>
+
+#include <compositionengine/impl/ClientCompositionRequestCache.h>
+#include <renderengine/DisplaySettings.h>
+#include <renderengine/LayerSettings.h>
+
+namespace android::compositionengine::impl {
+
+namespace {
+LayerFE::LayerSettings getLayerSettingsSnapshot(const LayerFE::LayerSettings& settings) {
+    LayerFE::LayerSettings snapshot = settings;
+    snapshot.source.buffer.buffer = nullptr;
+    snapshot.source.buffer.fence = nullptr;
+    return snapshot;
+}
+
+inline bool equalIgnoringSource(const renderengine::LayerSettings& lhs,
+                                const renderengine::LayerSettings& rhs) {
+    return lhs.geometry == rhs.geometry && lhs.alpha == rhs.alpha &&
+            lhs.sourceDataspace == rhs.sourceDataspace &&
+            lhs.colorTransform == rhs.colorTransform &&
+            lhs.disableBlending == rhs.disableBlending && lhs.shadow == rhs.shadow;
+}
+
+inline bool equalIgnoringBuffer(const renderengine::Buffer& lhs, const renderengine::Buffer& rhs) {
+    return lhs.textureName == rhs.textureName &&
+            lhs.useTextureFiltering == rhs.useTextureFiltering &&
+            lhs.textureTransform == rhs.textureTransform &&
+            lhs.usePremultipliedAlpha == rhs.usePremultipliedAlpha &&
+            lhs.isOpaque == rhs.isOpaque && lhs.isY410BT2020 == rhs.isY410BT2020 &&
+            lhs.maxMasteringLuminance == rhs.maxMasteringLuminance &&
+            lhs.maxContentLuminance == rhs.maxContentLuminance;
+}
+
+inline bool equalIgnoringBuffer(const renderengine::LayerSettings& lhs,
+                                const renderengine::LayerSettings& rhs) {
+    // compare LayerSettings without LayerSettings.PixelSource
+    return equalIgnoringSource(lhs, rhs) &&
+
+            // compare LayerSettings.PixelSource without buffer
+            lhs.source.solidColor == rhs.source.solidColor &&
+
+            // compare LayerSettings.PixelSource.Buffer without buffer & fence
+            equalIgnoringBuffer(lhs.source.buffer, rhs.source.buffer);
+}
+
+bool layerSettingsAreEqual(const LayerFE::LayerSettings& lhs, const LayerFE::LayerSettings& rhs) {
+    return lhs.bufferId == rhs.bufferId && lhs.frameNumber == rhs.frameNumber &&
+            equalIgnoringBuffer(lhs, rhs);
+}
+
+} // namespace
+
+ClientCompositionRequestCache::ClientCompositionRequest::ClientCompositionRequest(
+        const renderengine::DisplaySettings& initDisplay,
+        const std::vector<LayerFE::LayerSettings>& initLayerSettings)
+      : display(initDisplay) {
+    layerSettings.reserve(initLayerSettings.size());
+    for (const LayerFE::LayerSettings& settings : initLayerSettings) {
+        layerSettings.push_back(getLayerSettingsSnapshot(settings));
+    }
+}
+
+bool ClientCompositionRequestCache::ClientCompositionRequest::equals(
+        const renderengine::DisplaySettings& newDisplay,
+        const std::vector<LayerFE::LayerSettings>& newLayerSettings) const {
+    return newDisplay == display &&
+            std::equal(layerSettings.begin(), layerSettings.end(), newLayerSettings.begin(),
+                       newLayerSettings.end(), layerSettingsAreEqual);
+}
+
+bool ClientCompositionRequestCache::exists(
+        uint64_t bufferId, const renderengine::DisplaySettings& display,
+        const std::vector<LayerFE::LayerSettings>& layerSettings) const {
+    for (const auto& [cachedBufferId, cachedRequest] : mCache) {
+        if (cachedBufferId == bufferId) {
+            return cachedRequest.equals(display, layerSettings);
+        }
+    }
+    return false;
+}
+
+void ClientCompositionRequestCache::add(uint64_t bufferId,
+                                        const renderengine::DisplaySettings& display,
+                                        const std::vector<LayerFE::LayerSettings>& layerSettings) {
+    const ClientCompositionRequest request(display, layerSettings);
+    for (auto& [cachedBufferId, cachedRequest] : mCache) {
+        if (cachedBufferId == bufferId) {
+            cachedRequest = std::move(request);
+            return;
+        }
+    }
+
+    if (mCache.size() >= mMaxCacheSize) {
+        mCache.pop_front();
+    }
+
+    mCache.emplace_back(bufferId, std::move(request));
+}
+
+void ClientCompositionRequestCache::remove(uint64_t bufferId) {
+    for (auto it = mCache.begin(); it != mCache.end(); it++) {
+        if (it->first == bufferId) {
+            mCache.erase(it);
+            return;
+        }
+    }
+}
+
+} // namespace android::compositionengine::impl
diff --git a/services/surfaceflinger/CompositionEngine/src/Display.cpp b/services/surfaceflinger/CompositionEngine/src/Display.cpp
index 20f765c..13f5137 100644
--- a/services/surfaceflinger/CompositionEngine/src/Display.cpp
+++ b/services/surfaceflinger/CompositionEngine/src/Display.cpp
@@ -137,6 +137,10 @@
             compositionengine::impl::createRenderSurface(getCompositionEngine(), *this, args));
 }
 
+void Display::createClientCompositionCache(uint32_t cacheSize) {
+    cacheClientCompositionRequests(cacheSize);
+}
+
 std::unique_ptr<compositionengine::OutputLayer> Display::createOutputLayer(
         const std::shared_ptr<compositionengine::Layer>& layer,
         const sp<compositionengine::LayerFE>& layerFE) const {
diff --git a/services/surfaceflinger/CompositionEngine/src/Output.cpp b/services/surfaceflinger/CompositionEngine/src/Output.cpp
index 650b5c1..df33cf0 100644
--- a/services/surfaceflinger/CompositionEngine/src/Output.cpp
+++ b/services/surfaceflinger/CompositionEngine/src/Output.cpp
@@ -231,6 +231,14 @@
     dirtyEntireOutput();
 }
 
+void Output::cacheClientCompositionRequests(uint32_t cacheSize) {
+    if (cacheSize == 0) {
+        mClientCompositionRequestCache.reset();
+    } else {
+        mClientCompositionRequestCache = std::make_unique<ClientCompositionRequestCache>(cacheSize);
+    }
+};
+
 void Output::setRenderSurfaceForTest(std::unique_ptr<compositionengine::RenderSurface> surface) {
     mRenderSurface = std::move(surface);
 }
@@ -806,6 +814,7 @@
     ALOGV(__FUNCTION__);
 
     const auto& outputState = getState();
+    OutputCompositionState& outputCompositionState = editState();
     const TracedOrdinal<bool> hasClientComposition = {"hasClientComposition",
                                                       outputState.usesClientComposition};
     base::unique_fd readyFence;
@@ -839,7 +848,7 @@
     clientCompositionDisplay.clearRegion = Region::INVALID_REGION;
 
     // Generate the client composition requests for the layers on this output.
-    std::vector<renderengine::LayerSettings> clientCompositionLayers =
+    std::vector<LayerFE::LayerSettings> clientCompositionLayers =
             generateClientCompositionRequests(supportsProtectedContent,
                                               clientCompositionDisplay.clearRegion,
                                               clientCompositionDisplay.outputDataspace);
@@ -871,6 +880,19 @@
         return std::nullopt;
     }
 
+    // Check if the client composition requests were rendered into the provided graphic buffer. If
+    // so, we can reuse the buffer and avoid client composition.
+    if (mClientCompositionRequestCache) {
+        if (mClientCompositionRequestCache->exists(buf->getId(), clientCompositionDisplay,
+                                                   clientCompositionLayers)) {
+            outputCompositionState.reusedClientComposition = true;
+            setExpensiveRenderingExpected(false);
+            return readyFence;
+        }
+        mClientCompositionRequestCache->add(buf->getId(), clientCompositionDisplay,
+                                            clientCompositionLayers);
+    }
+
     // We boost GPU frequency here because there will be color spaces conversion
     // or complex GPU shaders and it's expensive. We boost the GPU frequency so that
     // GPU composition can finish in time. We must reset GPU frequency afterwards,
@@ -882,10 +904,25 @@
         setExpensiveRenderingExpected(true);
     }
 
+    std::vector<const renderengine::LayerSettings*> clientCompositionLayerPointers;
+    clientCompositionLayerPointers.reserve(clientCompositionLayers.size());
+    std::transform(clientCompositionLayers.begin(), clientCompositionLayers.end(),
+                   std::back_inserter(clientCompositionLayerPointers),
+                   [](LayerFE::LayerSettings& settings) -> renderengine::LayerSettings* {
+                       return &settings;
+                   });
+
     const nsecs_t renderEngineStart = systemTime();
-    renderEngine.drawLayers(clientCompositionDisplay, clientCompositionLayers,
-                            buf->getNativeBuffer(), /*useFramebufferCache=*/true, std::move(fd),
-                            &readyFence);
+    status_t status =
+            renderEngine.drawLayers(clientCompositionDisplay, clientCompositionLayerPointers,
+                                    buf->getNativeBuffer(), /*useFramebufferCache=*/true,
+                                    std::move(fd), &readyFence);
+
+    if (status != NO_ERROR && mClientCompositionRequestCache) {
+        // If rendering was not successful, remove the request from the cache.
+        mClientCompositionRequestCache->remove(buf->getId());
+    }
+
     auto& timeStats = getCompositionEngine().getTimeStats();
     if (readyFence.get() < 0) {
         timeStats.recordRenderEngineDuration(renderEngineStart, systemTime());
@@ -898,9 +935,9 @@
     return readyFence;
 }
 
-std::vector<renderengine::LayerSettings> Output::generateClientCompositionRequests(
+std::vector<LayerFE::LayerSettings> Output::generateClientCompositionRequests(
         bool supportsProtectedContent, Region& clearRegion, ui::Dataspace outputDataspace) {
-    std::vector<renderengine::LayerSettings> clientCompositionLayers;
+    std::vector<LayerFE::LayerSettings> clientCompositionLayers;
     ALOGV("Rendering client layers");
 
     const auto& outputState = getState();
@@ -944,15 +981,17 @@
                     supportsProtectedContent,
                     clientComposition ? clearRegion : dummyRegion,
             };
-            if (auto result = layerFE.prepareClientComposition(targetSettings)) {
+            if (std::optional<LayerFE::LayerSettings> result =
+                        layerFE.prepareClientComposition(targetSettings)) {
                 if (!clientComposition) {
-                    auto& layerSettings = *result;
+                    LayerFE::LayerSettings& layerSettings = *result;
                     layerSettings.source.buffer.buffer = nullptr;
                     layerSettings.source.solidColor = half3(0.0, 0.0, 0.0);
                     layerSettings.alpha = half(0.0);
                     layerSettings.disableBlending = true;
+                    layerSettings.frameNumber = 0;
                 } else {
-                    std::optional<renderengine::LayerSettings> shadowLayer =
+                    std::optional<LayerFE::LayerSettings> shadowLayer =
                             layerFE.prepareShadowClientComposition(*result, outputState.viewport,
                                                                    outputDataspace);
                     if (shadowLayer) {
@@ -979,13 +1018,12 @@
 }
 
 void Output::appendRegionFlashRequests(
-        const Region& flashRegion,
-        std::vector<renderengine::LayerSettings>& clientCompositionLayers) {
+        const Region& flashRegion, std::vector<LayerFE::LayerSettings>& clientCompositionLayers) {
     if (flashRegion.isEmpty()) {
         return;
     }
 
-    renderengine::LayerSettings layerSettings;
+    LayerFE::LayerSettings layerSettings;
     layerSettings.source.buffer.buffer = nullptr;
     layerSettings.source.solidColor = half3(1.0, 0.0, 1.0);
     layerSettings.alpha = half(1.0);
@@ -1065,6 +1103,7 @@
     auto& outputState = editState();
     outputState.usesClientComposition = true;
     outputState.usesDeviceComposition = false;
+    outputState.reusedClientComposition = false;
 }
 
 bool Output::getSkipColorTransform() const {
diff --git a/services/surfaceflinger/CompositionEngine/src/OutputCompositionState.cpp b/services/surfaceflinger/CompositionEngine/src/OutputCompositionState.cpp
index 0fcc308..84d79f7 100644
--- a/services/surfaceflinger/CompositionEngine/src/OutputCompositionState.cpp
+++ b/services/surfaceflinger/CompositionEngine/src/OutputCompositionState.cpp
@@ -27,6 +27,7 @@
     dumpVal(out, "usesClientComposition", usesClientComposition);
     dumpVal(out, "usesDeviceComposition", usesDeviceComposition);
     dumpVal(out, "flipClientTarget", flipClientTarget);
+    dumpVal(out, "reusedClientComposition", reusedClientComposition);
 
     dumpVal(out, "layerStack", layerStackId);
     dumpVal(out, "layerStackInternal", layerStackInternal);
diff --git a/services/surfaceflinger/CompositionEngine/tests/OutputTest.cpp b/services/surfaceflinger/CompositionEngine/tests/OutputTest.cpp
index 6761b86..b559e42 100644
--- a/services/surfaceflinger/CompositionEngine/tests/OutputTest.cpp
+++ b/services/surfaceflinger/CompositionEngine/tests/OutputTest.cpp
@@ -47,12 +47,14 @@
 using testing::ByMove;
 using testing::ByRef;
 using testing::DoAll;
+using testing::ElementsAre;
 using testing::ElementsAreArray;
 using testing::Eq;
 using testing::InSequence;
 using testing::Invoke;
 using testing::IsEmpty;
 using testing::Mock;
+using testing::Pointee;
 using testing::Property;
 using testing::Ref;
 using testing::Return;
@@ -62,6 +64,7 @@
 
 constexpr auto TR_IDENT = 0u;
 constexpr auto TR_ROT_90 = HAL_TRANSFORM_ROT_90;
+constexpr auto MAX_CLIENT_COMPOSITION_CACHE_SIZE = 3;
 
 const mat4 kIdentity;
 const mat4 kNonIdentityHalf = mat4() * 0.5;
@@ -2765,9 +2768,9 @@
         // mock implementations.
         MOCK_CONST_METHOD0(getSkipColorTransform, bool());
         MOCK_METHOD3(generateClientCompositionRequests,
-                     std::vector<renderengine::LayerSettings>(bool, Region&, ui::Dataspace));
+                     std::vector<LayerFE::LayerSettings>(bool, Region&, ui::Dataspace));
         MOCK_METHOD2(appendRegionFlashRequests,
-                     void(const Region&, std::vector<renderengine::LayerSettings>&));
+                     void(const Region&, std::vector<LayerFE::LayerSettings>&));
         MOCK_METHOD1(setExpensiveRenderingExpected, void(bool));
     };
 
@@ -2775,6 +2778,7 @@
         mOutput.setDisplayColorProfileForTest(
                 std::unique_ptr<DisplayColorProfile>(mDisplayColorProfile));
         mOutput.setRenderSurfaceForTest(std::unique_ptr<RenderSurface>(mRenderSurface));
+        mOutput.cacheClientCompositionRequests(MAX_CLIENT_COMPOSITION_CACHE_SIZE);
 
         mOutput.mState.frame = kDefaultOutputFrame;
         mOutput.mState.viewport = kDefaultOutputViewport;
@@ -2787,6 +2791,7 @@
         mOutput.mState.needsFiltering = false;
         mOutput.mState.usesClientComposition = true;
         mOutput.mState.usesDeviceComposition = false;
+        mOutput.mState.reusedClientComposition = false;
 
         EXPECT_CALL(mOutput, getCompositionEngine()).WillRepeatedly(ReturnRef(mCompositionEngine));
         EXPECT_CALL(mCompositionEngine, getRenderEngine()).WillRepeatedly(ReturnRef(mRenderEngine));
@@ -2863,7 +2868,7 @@
     EXPECT_CALL(*mDisplayColorProfile, hasWideColorGamut()).WillRepeatedly(Return(true));
     EXPECT_CALL(mRenderEngine, supportsProtectedContent()).WillRepeatedly(Return(false));
     EXPECT_CALL(mOutput, generateClientCompositionRequests(_, _, kDefaultOutputDataspace))
-            .WillRepeatedly(Return(std::vector<renderengine::LayerSettings>{}));
+            .WillRepeatedly(Return(std::vector<LayerFE::LayerSettings>{}));
     EXPECT_CALL(mOutput, appendRegionFlashRequests(RegionEq(kDebugRegion), _))
             .WillRepeatedly(Return());
 
@@ -2877,7 +2882,7 @@
     EXPECT_CALL(*mDisplayColorProfile, hasWideColorGamut()).WillRepeatedly(Return(true));
     EXPECT_CALL(mRenderEngine, supportsProtectedContent()).WillRepeatedly(Return(false));
     EXPECT_CALL(mOutput, generateClientCompositionRequests(_, _, kDefaultOutputDataspace))
-            .WillRepeatedly(Return(std::vector<renderengine::LayerSettings>{}));
+            .WillRepeatedly(Return(std::vector<LayerFE::LayerSettings>{}));
     EXPECT_CALL(mOutput, appendRegionFlashRequests(RegionEq(kDebugRegion), _))
             .WillRepeatedly(Return());
 
@@ -2889,8 +2894,8 @@
 }
 
 TEST_F(OutputComposeSurfacesTest, buildsAndRendersRequestList) {
-    renderengine::LayerSettings r1;
-    renderengine::LayerSettings r2;
+    LayerFE::LayerSettings r1;
+    LayerFE::LayerSettings r2;
 
     r1.geometry.boundaries = FloatRect{1, 2, 3, 4};
     r2.geometry.boundaries = FloatRect{5, 6, 7, 8};
@@ -2899,26 +2904,143 @@
     EXPECT_CALL(*mDisplayColorProfile, hasWideColorGamut()).WillRepeatedly(Return(true));
     EXPECT_CALL(mRenderEngine, supportsProtectedContent()).WillRepeatedly(Return(false));
     EXPECT_CALL(mOutput, generateClientCompositionRequests(_, _, kDefaultOutputDataspace))
-            .WillRepeatedly(Return(std::vector<renderengine::LayerSettings>{r1}));
+            .WillRepeatedly(Return(std::vector<LayerFE::LayerSettings>{r1}));
     EXPECT_CALL(mOutput, appendRegionFlashRequests(RegionEq(kDebugRegion), _))
             .WillRepeatedly(
                     Invoke([&](const Region&,
-                               std::vector<renderengine::LayerSettings>& clientCompositionLayers) {
+                               std::vector<LayerFE::LayerSettings>& clientCompositionLayers) {
                         clientCompositionLayers.emplace_back(r2);
                     }));
 
     EXPECT_CALL(*mRenderSurface, dequeueBuffer(_)).WillRepeatedly(Return(mOutputBuffer));
-    EXPECT_CALL(mRenderEngine, drawLayers(_, ElementsAreArray({r1, r2}), _, true, _, _))
+    EXPECT_CALL(mRenderEngine, drawLayers(_, ElementsAre(Pointee(r1), Pointee(r2)), _, true, _, _))
             .WillRepeatedly(Return(NO_ERROR));
 
     verify().execute().expectAFenceWasReturned();
 }
 
+TEST_F(OutputComposeSurfacesTest, renderDuplicateClientCompositionRequestsWithoutCache) {
+    mOutput.cacheClientCompositionRequests(0);
+    LayerFE::LayerSettings r1;
+    LayerFE::LayerSettings r2;
+
+    r1.geometry.boundaries = FloatRect{1, 2, 3, 4};
+    r2.geometry.boundaries = FloatRect{5, 6, 7, 8};
+
+    EXPECT_CALL(mOutput, getSkipColorTransform()).WillRepeatedly(Return(false));
+    EXPECT_CALL(*mDisplayColorProfile, hasWideColorGamut()).WillRepeatedly(Return(true));
+    EXPECT_CALL(mRenderEngine, supportsProtectedContent()).WillRepeatedly(Return(false));
+    EXPECT_CALL(mOutput, generateClientCompositionRequests(_, _, kDefaultOutputDataspace))
+            .WillRepeatedly(Return(std::vector<LayerFE::LayerSettings>{r1, r2}));
+    EXPECT_CALL(mOutput, appendRegionFlashRequests(RegionEq(kDebugRegion), _))
+            .WillRepeatedly(Return());
+
+    EXPECT_CALL(*mRenderSurface, dequeueBuffer(_)).WillRepeatedly(Return(mOutputBuffer));
+    EXPECT_CALL(mRenderEngine, drawLayers(_, ElementsAre(Pointee(r1), Pointee(r2)), _, true, _, _))
+            .Times(2)
+            .WillOnce(Return(NO_ERROR));
+
+    verify().execute().expectAFenceWasReturned();
+    EXPECT_FALSE(mOutput.mState.reusedClientComposition);
+
+    verify().execute().expectAFenceWasReturned();
+    EXPECT_FALSE(mOutput.mState.reusedClientComposition);
+}
+
+TEST_F(OutputComposeSurfacesTest, skipDuplicateClientCompositionRequests) {
+    mOutput.cacheClientCompositionRequests(3);
+    LayerFE::LayerSettings r1;
+    LayerFE::LayerSettings r2;
+
+    r1.geometry.boundaries = FloatRect{1, 2, 3, 4};
+    r2.geometry.boundaries = FloatRect{5, 6, 7, 8};
+
+    EXPECT_CALL(mOutput, getSkipColorTransform()).WillRepeatedly(Return(false));
+    EXPECT_CALL(*mDisplayColorProfile, hasWideColorGamut()).WillRepeatedly(Return(true));
+    EXPECT_CALL(mRenderEngine, supportsProtectedContent()).WillRepeatedly(Return(false));
+    EXPECT_CALL(mOutput, generateClientCompositionRequests(_, _, kDefaultOutputDataspace))
+            .WillRepeatedly(Return(std::vector<LayerFE::LayerSettings>{r1, r2}));
+    EXPECT_CALL(mOutput, appendRegionFlashRequests(RegionEq(kDebugRegion), _))
+            .WillRepeatedly(Return());
+
+    EXPECT_CALL(*mRenderSurface, dequeueBuffer(_)).WillRepeatedly(Return(mOutputBuffer));
+    EXPECT_CALL(mRenderEngine, drawLayers(_, ElementsAre(Pointee(r1), Pointee(r2)), _, true, _, _))
+            .WillOnce(Return(NO_ERROR));
+    EXPECT_CALL(mOutput, setExpensiveRenderingExpected(false));
+
+    verify().execute().expectAFenceWasReturned();
+    EXPECT_FALSE(mOutput.mState.reusedClientComposition);
+
+    // We do not expect another call to draw layers.
+    verify().execute().expectAFenceWasReturned();
+    EXPECT_TRUE(mOutput.mState.reusedClientComposition);
+}
+
+TEST_F(OutputComposeSurfacesTest, clientCompositionIfBufferChanges) {
+    LayerFE::LayerSettings r1;
+    LayerFE::LayerSettings r2;
+
+    r1.geometry.boundaries = FloatRect{1, 2, 3, 4};
+    r2.geometry.boundaries = FloatRect{5, 6, 7, 8};
+
+    EXPECT_CALL(mOutput, getSkipColorTransform()).WillRepeatedly(Return(false));
+    EXPECT_CALL(*mDisplayColorProfile, hasWideColorGamut()).WillRepeatedly(Return(true));
+    EXPECT_CALL(mRenderEngine, supportsProtectedContent()).WillRepeatedly(Return(false));
+    EXPECT_CALL(mOutput, generateClientCompositionRequests(_, _, kDefaultOutputDataspace))
+            .WillRepeatedly(Return(std::vector<LayerFE::LayerSettings>{r1, r2}));
+    EXPECT_CALL(mOutput, appendRegionFlashRequests(RegionEq(kDebugRegion), _))
+            .WillRepeatedly(Return());
+
+    sp<GraphicBuffer> otherOutputBuffer = new GraphicBuffer();
+    EXPECT_CALL(*mRenderSurface, dequeueBuffer(_))
+            .WillOnce(Return(mOutputBuffer))
+            .WillOnce(Return(otherOutputBuffer));
+    EXPECT_CALL(mRenderEngine, drawLayers(_, ElementsAre(Pointee(r1), Pointee(r2)), _, true, _, _))
+            .WillRepeatedly(Return(NO_ERROR));
+
+    verify().execute().expectAFenceWasReturned();
+    EXPECT_FALSE(mOutput.mState.reusedClientComposition);
+
+    verify().execute().expectAFenceWasReturned();
+    EXPECT_FALSE(mOutput.mState.reusedClientComposition);
+}
+
+TEST_F(OutputComposeSurfacesTest, clientCompositionIfRequestChanges) {
+    LayerFE::LayerSettings r1;
+    LayerFE::LayerSettings r2;
+    LayerFE::LayerSettings r3;
+
+    r1.geometry.boundaries = FloatRect{1, 2, 3, 4};
+    r2.geometry.boundaries = FloatRect{5, 6, 7, 8};
+    r3.geometry.boundaries = FloatRect{5, 6, 7, 9};
+
+    EXPECT_CALL(mOutput, getSkipColorTransform()).WillRepeatedly(Return(false));
+    EXPECT_CALL(*mDisplayColorProfile, hasWideColorGamut()).WillRepeatedly(Return(true));
+    EXPECT_CALL(mRenderEngine, supportsProtectedContent()).WillRepeatedly(Return(false));
+    EXPECT_CALL(mOutput, generateClientCompositionRequests(_, _, kDefaultOutputDataspace))
+            .WillOnce(Return(std::vector<LayerFE::LayerSettings>{r1, r2}))
+            .WillOnce(Return(std::vector<LayerFE::LayerSettings>{r1, r3}));
+    EXPECT_CALL(mOutput, appendRegionFlashRequests(RegionEq(kDebugRegion), _))
+            .WillRepeatedly(Return());
+
+    EXPECT_CALL(*mRenderSurface, dequeueBuffer(_)).WillRepeatedly(Return(mOutputBuffer));
+    EXPECT_CALL(mRenderEngine, drawLayers(_, ElementsAre(Pointee(r1), Pointee(r2)), _, true, _, _))
+            .WillOnce(Return(NO_ERROR));
+    EXPECT_CALL(mRenderEngine, drawLayers(_, ElementsAre(Pointee(r1), Pointee(r3)), _, true, _, _))
+            .WillOnce(Return(NO_ERROR));
+
+    verify().execute().expectAFenceWasReturned();
+    EXPECT_FALSE(mOutput.mState.reusedClientComposition);
+
+    verify().execute().expectAFenceWasReturned();
+    EXPECT_FALSE(mOutput.mState.reusedClientComposition);
+}
+
 struct OutputComposeSurfacesTest_UsesExpectedDisplaySettings : public OutputComposeSurfacesTest {
     OutputComposeSurfacesTest_UsesExpectedDisplaySettings() {
         EXPECT_CALL(mRenderEngine, supportsProtectedContent()).WillRepeatedly(Return(false));
         EXPECT_CALL(mOutput, generateClientCompositionRequests(_, _, kDefaultOutputDataspace))
-                .WillRepeatedly(Return(std::vector<renderengine::LayerSettings>{}));
+                .WillRepeatedly(Return(std::vector<LayerFE::LayerSettings>{}));
         EXPECT_CALL(mOutput, appendRegionFlashRequests(RegionEq(kDebugRegion), _))
                 .WillRepeatedly(Return());
         EXPECT_CALL(*mRenderSurface, dequeueBuffer(_)).WillRepeatedly(Return(mOutputBuffer));
@@ -3048,7 +3170,7 @@
         EXPECT_CALL(*mDisplayColorProfile, hasWideColorGamut()).WillRepeatedly(Return(true));
 
         EXPECT_CALL(mOutput, generateClientCompositionRequests(_, _, _))
-                .WillRepeatedly(Return(std::vector<renderengine::LayerSettings>{}));
+                .WillRepeatedly(Return(std::vector<LayerFE::LayerSettings>{}));
         EXPECT_CALL(mOutput, appendRegionFlashRequests(RegionEq(kDebugRegion), _))
                 .WillRepeatedly(Return());
         EXPECT_CALL(*mRenderSurface, dequeueBuffer(_)).WillRepeatedly(Return(mOutputBuffer));
@@ -3166,7 +3288,7 @@
     mOutput.mState.dataspace = kExpensiveOutputDataspace;
 
     EXPECT_CALL(mOutput, generateClientCompositionRequests(_, _, kExpensiveOutputDataspace))
-            .WillOnce(Return(std::vector<renderengine::LayerSettings>{}));
+            .WillOnce(Return(std::vector<LayerFE::LayerSettings>{}));
 
     // For this test, we also check the call order of key functions.
     InSequence seq;
@@ -3184,7 +3306,7 @@
 struct GenerateClientCompositionRequestsTest : public testing::Test {
     struct OutputPartialMock : public OutputPartialMockBase {
         // compositionengine::Output overrides
-        std::vector<renderengine::LayerSettings> generateClientCompositionRequests(
+        std::vector<LayerFE::LayerSettings> generateClientCompositionRequests(
                 bool supportsProtectedContent, Region& clearRegion,
                 ui::Dataspace dataspace) override {
             return impl::Output::generateClientCompositionRequests(supportsProtectedContent,
@@ -3206,7 +3328,7 @@
         StrictMock<mock::LayerFE> mLayerFE;
         LayerFECompositionState mLayerFEState;
         impl::OutputLayerCompositionState mOutputLayerState;
-        renderengine::LayerSettings mRELayerSettings;
+        LayerFE::LayerSettings mLayerSettings;
     };
 
     GenerateClientCompositionRequestsTest() {
@@ -3237,11 +3359,11 @@
             mLayers[i].mOutputLayerState.clearClientTarget = false;
             mLayers[i].mOutputLayerState.visibleRegion = Region(kDisplayFrame);
             mLayers[i].mLayerFEState.isOpaque = true;
-            mLayers[i].mRELayerSettings.geometry.boundaries =
+            mLayers[i].mLayerSettings.geometry.boundaries =
                     FloatRect{static_cast<float>(i + 1), 0.f, 0.f, 0.f};
-            mLayers[i].mRELayerSettings.source.solidColor = {1.0f, 1.0f, 1.0f};
-            mLayers[i].mRELayerSettings.alpha = 1.0f;
-            mLayers[i].mRELayerSettings.disableBlending = false;
+            mLayers[i].mLayerSettings.source.solidColor = {1.0f, 1.0f, 1.0f};
+            mLayers[i].mLayerSettings.alpha = 1.0f;
+            mLayers[i].mLayerSettings.disableBlending = false;
 
             EXPECT_CALL(mOutput, getOutputLayerOrderedByZByIndex(i))
                     .WillRepeatedly(Return(&mLayers[i].mOutputLayer));
@@ -3292,30 +3414,30 @@
 }
 
 TEST_F(GenerateClientCompositionRequestsTest_ThreeLayers, gathersClientCompositionRequests) {
-    renderengine::LayerSettings mREShadowSettings;
-    mREShadowSettings.source.solidColor = {0.1f, 0.1f, 0.1f};
+    LayerFE::LayerSettings mShadowSettings;
+    mShadowSettings.source.solidColor = {0.1f, 0.1f, 0.1f};
 
     EXPECT_CALL(mLayers[0].mLayerFE, prepareClientComposition(_)).WillOnce(Return(std::nullopt));
     EXPECT_CALL(mLayers[1].mLayerFE, prepareClientComposition(_))
-            .WillOnce(Return(mLayers[1].mRELayerSettings));
+            .WillOnce(Return(mLayers[1].mLayerSettings));
     EXPECT_CALL(mLayers[1].mLayerFE,
-                prepareShadowClientComposition(mLayers[1].mRELayerSettings, kDisplayViewport,
+                prepareShadowClientComposition(mLayers[1].mLayerSettings, kDisplayViewport,
                                                kDisplayDataspace))
             .WillOnce(Return(std::nullopt));
     EXPECT_CALL(mLayers[2].mLayerFE, prepareClientComposition(_))
-            .WillOnce(Return(mLayers[2].mRELayerSettings));
+            .WillOnce(Return(mLayers[2].mLayerSettings));
     EXPECT_CALL(mLayers[2].mLayerFE,
-                prepareShadowClientComposition(mLayers[2].mRELayerSettings, kDisplayViewport,
+                prepareShadowClientComposition(mLayers[2].mLayerSettings, kDisplayViewport,
                                                kDisplayDataspace))
-            .WillOnce(Return(mREShadowSettings));
+            .WillOnce(Return(mShadowSettings));
 
     Region accumClearRegion(Rect(10, 11, 12, 13));
     auto requests = mOutput.generateClientCompositionRequests(false /* supportsProtectedContent */,
                                                               accumClearRegion, kDisplayDataspace);
     ASSERT_EQ(3u, requests.size());
-    EXPECT_EQ(mLayers[1].mRELayerSettings, requests[0]);
-    EXPECT_EQ(mREShadowSettings, requests[1]);
-    EXPECT_EQ(mLayers[2].mRELayerSettings, requests[2]);
+    EXPECT_EQ(mLayers[1].mLayerSettings, requests[0]);
+    EXPECT_EQ(mShadowSettings, requests[1]);
+    EXPECT_EQ(mLayers[2].mLayerSettings, requests[2]);
 
     EXPECT_THAT(accumClearRegion, RegionEq(Region(Rect(10, 11, 12, 13))));
 
@@ -3340,7 +3462,7 @@
     mLayers[2].mLayerFEState.isOpaque = true;
 
     EXPECT_CALL(mLayers[2].mLayerFE, prepareClientComposition(_))
-            .WillOnce(Return(mLayers[2].mRELayerSettings));
+            .WillOnce(Return(mLayers[2].mLayerSettings));
     EXPECT_CALL(mLayers[2].mLayerFE, prepareShadowClientComposition(_, _, _))
             .WillOnce(Return(std::nullopt));
 
@@ -3348,7 +3470,7 @@
     auto requests = mOutput.generateClientCompositionRequests(false /* supportsProtectedContent */,
                                                               accumClearRegion, kDisplayDataspace);
     ASSERT_EQ(1u, requests.size());
-    EXPECT_EQ(mLayers[2].mRELayerSettings, requests[0]);
+    EXPECT_EQ(mLayers[2].mLayerSettings, requests[0]);
 
     EXPECT_THAT(accumClearRegion, RegionEq(Region(Rect(10, 11, 12, 13))));
 }
@@ -3368,7 +3490,7 @@
     mLayers[2].mLayerFEState.isOpaque = false;
 
     EXPECT_CALL(mLayers[2].mLayerFE, prepareClientComposition(_))
-            .WillOnce(Return(mLayers[2].mRELayerSettings));
+            .WillOnce(Return(mLayers[2].mLayerSettings));
     EXPECT_CALL(mLayers[2].mLayerFE, prepareShadowClientComposition(_, _, _))
             .WillOnce(Return(std::nullopt));
 
@@ -3376,7 +3498,7 @@
     auto requests = mOutput.generateClientCompositionRequests(false /* supportsProtectedContent */,
                                                               accumClearRegion, kDisplayDataspace);
     ASSERT_EQ(1u, requests.size());
-    EXPECT_EQ(mLayers[2].mRELayerSettings, requests[0]);
+    EXPECT_EQ(mLayers[2].mLayerSettings, requests[0]);
 
     EXPECT_THAT(accumClearRegion, RegionEq(Region(Rect(10, 11, 12, 13))));
 }
@@ -3401,9 +3523,9 @@
     mLayers[2].mLayerFEState.isOpaque = true;
 
     EXPECT_CALL(mLayers[1].mLayerFE, prepareClientComposition(_))
-            .WillOnce(Return(mLayers[1].mRELayerSettings));
+            .WillOnce(Return(mLayers[1].mLayerSettings));
     EXPECT_CALL(mLayers[2].mLayerFE, prepareClientComposition(_))
-            .WillOnce(Return(mLayers[2].mRELayerSettings));
+            .WillOnce(Return(mLayers[2].mLayerSettings));
     EXPECT_CALL(mLayers[2].mLayerFE, prepareShadowClientComposition(_, _, _))
             .WillOnce(Return(std::nullopt));
 
@@ -3413,13 +3535,13 @@
     ASSERT_EQ(2u, requests.size());
 
     // The second layer is expected to be rendered as alpha=0 black with no blending
-    EXPECT_EQ(mLayers[1].mRELayerSettings.geometry.boundaries, requests[0].geometry.boundaries);
+    EXPECT_EQ(mLayers[1].mLayerSettings.geometry.boundaries, requests[0].geometry.boundaries);
     EXPECT_FALSE(requests[0].source.buffer.buffer);
     EXPECT_EQ((half3{0.f, 0.f, 0.f}), requests[0].source.solidColor);
     EXPECT_EQ(half{0.f}, requests[0].alpha);
     EXPECT_EQ(true, requests[0].disableBlending);
 
-    EXPECT_EQ(mLayers[2].mRELayerSettings, requests[1]);
+    EXPECT_EQ(mLayers[2].mLayerSettings, requests[1]);
 
     EXPECT_THAT(accumClearRegion, RegionEq(Region(Rect(10, 11, 12, 13))));
 }
@@ -3689,12 +3811,12 @@
     leftLayer.mOutputLayerState.clearClientTarget = false;
     leftLayer.mOutputLayerState.visibleRegion = Region(Rect(0, 0, 1000, 1000));
     leftLayer.mLayerFEState.isOpaque = true;
-    leftLayer.mRELayerSettings.source.solidColor = {1.f, 0.f, 0.f};
+    leftLayer.mLayerSettings.source.solidColor = {1.f, 0.f, 0.f};
 
     rightLayer.mOutputLayerState.clearClientTarget = false;
     rightLayer.mOutputLayerState.visibleRegion = Region(Rect(1000, 0, 2000, 1000));
     rightLayer.mLayerFEState.isOpaque = true;
-    rightLayer.mRELayerSettings.source.solidColor = {0.f, 1.f, 0.f};
+    rightLayer.mLayerSettings.source.solidColor = {0.f, 1.f, 0.f};
 
     EXPECT_CALL(mOutput, getOutputLayerCount()).WillRepeatedly(Return(2u));
     EXPECT_CALL(mOutput, getOutputLayerOrderedByZByIndex(0u))
@@ -3716,9 +3838,9 @@
     EXPECT_CALL(leftLayer.mOutputLayer, requiresClientComposition()).WillRepeatedly(Return(true));
     EXPECT_CALL(leftLayer.mOutputLayer, needsFiltering()).WillRepeatedly(Return(false));
     EXPECT_CALL(leftLayer.mLayerFE, prepareClientComposition(Eq(ByRef(leftLayerSettings))))
-            .WillOnce(Return(leftLayer.mRELayerSettings));
+            .WillOnce(Return(leftLayer.mLayerSettings));
     EXPECT_CALL(leftLayer.mLayerFE,
-                prepareShadowClientComposition(leftLayer.mRELayerSettings, kPortraitViewport,
+                prepareShadowClientComposition(leftLayer.mLayerSettings, kPortraitViewport,
                                                kOutputDataspace))
             .WillOnce(Return(std::nullopt));
 
@@ -3734,9 +3856,9 @@
     EXPECT_CALL(rightLayer.mOutputLayer, requiresClientComposition()).WillRepeatedly(Return(true));
     EXPECT_CALL(rightLayer.mOutputLayer, needsFiltering()).WillRepeatedly(Return(false));
     EXPECT_CALL(rightLayer.mLayerFE, prepareClientComposition(Eq(ByRef(rightLayerSettings))))
-            .WillOnce(Return(rightLayer.mRELayerSettings));
+            .WillOnce(Return(rightLayer.mLayerSettings));
     EXPECT_CALL(rightLayer.mLayerFE,
-                prepareShadowClientComposition(rightLayer.mRELayerSettings, kPortraitViewport,
+                prepareShadowClientComposition(rightLayer.mLayerSettings, kPortraitViewport,
                                                kOutputDataspace))
             .WillOnce(Return(std::nullopt));
 
@@ -3744,8 +3866,8 @@
     auto requests = mOutput.generateClientCompositionRequests(supportsProtectedContent,
                                                               accumClearRegion, kOutputDataspace);
     ASSERT_EQ(2u, requests.size());
-    EXPECT_EQ(leftLayer.mRELayerSettings, requests[0]);
-    EXPECT_EQ(rightLayer.mRELayerSettings, requests[1]);
+    EXPECT_EQ(leftLayer.mLayerSettings, requests[0]);
+    EXPECT_EQ(rightLayer.mLayerSettings, requests[1]);
 }
 
 TEST_F(GenerateClientCompositionRequestsTest_ThreeLayers,
@@ -3755,8 +3877,8 @@
     const Region kShadowRegion = Region(kContentWithShadow).subtract(kContent);
     const Region kPartialShadowRegion = Region(kContentWithShadow).subtract(Rect(40, 40, 60, 80));
 
-    renderengine::LayerSettings mREShadowSettings;
-    mREShadowSettings.source.solidColor = {0.1f, 0.1f, 0.1f};
+    LayerFE::LayerSettings mShadowSettings;
+    mShadowSettings.source.solidColor = {0.1f, 0.1f, 0.1f};
 
     mLayers[2].mOutputLayerState.visibleRegion = kPartialShadowRegion;
     mLayers[2].mOutputLayerState.shadowRegion = kShadowRegion;
@@ -3764,18 +3886,18 @@
     EXPECT_CALL(mLayers[0].mOutputLayer, requiresClientComposition()).WillOnce(Return(false));
     EXPECT_CALL(mLayers[1].mOutputLayer, requiresClientComposition()).WillOnce(Return(false));
     EXPECT_CALL(mLayers[2].mLayerFE, prepareClientComposition(_))
-            .WillOnce(Return(mLayers[2].mRELayerSettings));
+            .WillOnce(Return(mLayers[2].mLayerSettings));
     EXPECT_CALL(mLayers[2].mLayerFE,
-                prepareShadowClientComposition(mLayers[2].mRELayerSettings, kDisplayViewport,
+                prepareShadowClientComposition(mLayers[2].mLayerSettings, kDisplayViewport,
                                                kDisplayDataspace))
-            .WillOnce(Return(mREShadowSettings));
+            .WillOnce(Return(mShadowSettings));
 
     Region accumClearRegion(Rect(10, 11, 12, 13));
     auto requests = mOutput.generateClientCompositionRequests(false /* supportsProtectedContent */,
                                                               accumClearRegion, kDisplayDataspace);
     ASSERT_EQ(1u, requests.size());
 
-    EXPECT_EQ(mREShadowSettings, requests[0]);
+    EXPECT_EQ(mShadowSettings, requests[0]);
 }
 
 TEST_F(GenerateClientCompositionRequestsTest_ThreeLayers,
@@ -3786,8 +3908,8 @@
     const Region kPartialContentWithPartialShadowRegion =
             Region(kContentWithShadow).subtract(Rect(40, 40, 50, 80));
 
-    renderengine::LayerSettings mREShadowSettings;
-    mREShadowSettings.source.solidColor = {0.1f, 0.1f, 0.1f};
+    LayerFE::LayerSettings mShadowSettings;
+    mShadowSettings.source.solidColor = {0.1f, 0.1f, 0.1f};
 
     mLayers[2].mOutputLayerState.visibleRegion = kPartialContentWithPartialShadowRegion;
     mLayers[2].mOutputLayerState.shadowRegion = kShadowRegion;
@@ -3795,19 +3917,19 @@
     EXPECT_CALL(mLayers[0].mOutputLayer, requiresClientComposition()).WillOnce(Return(false));
     EXPECT_CALL(mLayers[1].mOutputLayer, requiresClientComposition()).WillOnce(Return(false));
     EXPECT_CALL(mLayers[2].mLayerFE, prepareClientComposition(_))
-            .WillOnce(Return(mLayers[2].mRELayerSettings));
+            .WillOnce(Return(mLayers[2].mLayerSettings));
     EXPECT_CALL(mLayers[2].mLayerFE,
-                prepareShadowClientComposition(mLayers[2].mRELayerSettings, kDisplayViewport,
+                prepareShadowClientComposition(mLayers[2].mLayerSettings, kDisplayViewport,
                                                kDisplayDataspace))
-            .WillOnce(Return(mREShadowSettings));
+            .WillOnce(Return(mShadowSettings));
 
     Region accumClearRegion(Rect(10, 11, 12, 13));
     auto requests = mOutput.generateClientCompositionRequests(false /* supportsProtectedContent */,
                                                               accumClearRegion, kDisplayDataspace);
     ASSERT_EQ(2u, requests.size());
 
-    EXPECT_EQ(mREShadowSettings, requests[0]);
-    EXPECT_EQ(mLayers[2].mRELayerSettings, requests[1]);
+    EXPECT_EQ(mShadowSettings, requests[0]);
+    EXPECT_EQ(mLayers[2].mLayerSettings, requests[1]);
 }
 
 } // namespace
diff --git a/services/surfaceflinger/DisplayDevice.cpp b/services/surfaceflinger/DisplayDevice.cpp
index e2122d1..4ae6dad 100644
--- a/services/surfaceflinger/DisplayDevice.cpp
+++ b/services/surfaceflinger/DisplayDevice.cpp
@@ -70,6 +70,12 @@
                                                                  args.nativeWindow.get()),
                                                          args.nativeWindow, args.displaySurface});
 
+    if (!mFlinger->mDisableClientCompositionCache &&
+        SurfaceFlinger::maxFrameBufferAcquiredBuffers > 0) {
+        mCompositionDisplay->createClientCompositionCache(
+                static_cast<uint32_t>(SurfaceFlinger::maxFrameBufferAcquiredBuffers));
+    }
+
     mCompositionDisplay->createDisplayColorProfile(
             compositionengine::DisplayColorProfileCreationArgs{args.hasWideColorGamut,
                                                                std::move(args.hdrCapabilities),
diff --git a/services/surfaceflinger/Layer.cpp b/services/surfaceflinger/Layer.cpp
index f4d4329..11ae46d 100644
--- a/services/surfaceflinger/Layer.cpp
+++ b/services/surfaceflinger/Layer.cpp
@@ -551,7 +551,7 @@
 // drawing...
 // ---------------------------------------------------------------------------
 
-std::optional<renderengine::LayerSettings> Layer::prepareClientComposition(
+std::optional<compositionengine::LayerFE::LayerSettings> Layer::prepareClientComposition(
         compositionengine::LayerFE::ClientCompositionTargetSettings& targetSettings) {
     if (!getCompositionLayer()) {
         return {};
@@ -559,7 +559,8 @@
 
     FloatRect bounds = getBounds();
     half alpha = getAlpha();
-    renderengine::LayerSettings layerSettings;
+
+    compositionengine::LayerFE::LayerSettings layerSettings;
     layerSettings.geometry.boundaries = bounds;
     if (targetSettings.useIdentityTransform) {
         layerSettings.geometry.positionTransform = mat4();
@@ -581,8 +582,8 @@
     return layerSettings;
 }
 
-std::optional<renderengine::LayerSettings> Layer::prepareShadowClientComposition(
-        const renderengine::LayerSettings& casterLayerSettings, const Rect& displayViewport,
+std::optional<compositionengine::LayerFE::LayerSettings> Layer::prepareShadowClientComposition(
+        const LayerFE::LayerSettings& casterLayerSettings, const Rect& displayViewport,
         ui::Dataspace outputDataspace) {
     renderengine::ShadowSettings shadow = getShadowSettings(displayViewport);
     if (shadow.length <= 0.f) {
@@ -593,7 +594,8 @@
     const bool casterIsOpaque = ((casterLayerSettings.source.buffer.buffer != nullptr) &&
                                  casterLayerSettings.source.buffer.isOpaque);
 
-    renderengine::LayerSettings shadowLayer = casterLayerSettings;
+    compositionengine::LayerFE::LayerSettings shadowLayer = casterLayerSettings;
+
     shadowLayer.shadow = shadow;
     shadowLayer.geometry.boundaries = mBounds; // ignore transparent region
 
@@ -604,13 +606,16 @@
     shadowLayer.shadow.spotColor *= casterAlpha;
     shadowLayer.sourceDataspace = outputDataspace;
     shadowLayer.source.buffer.buffer = nullptr;
+    shadowLayer.source.buffer.fence = nullptr;
+    shadowLayer.frameNumber = 0;
+    shadowLayer.bufferId = 0;
 
     if (shadowLayer.shadow.ambientColor.a <= 0.f && shadowLayer.shadow.spotColor.a <= 0.f) {
         return {};
     }
 
     float casterCornerRadius = shadowLayer.geometry.roundedCornersRadius;
-    const FloatRect& cornerRadiusCropRect = casterLayerSettings.geometry.roundedCornersCrop;
+    const FloatRect& cornerRadiusCropRect = shadowLayer.geometry.roundedCornersCrop;
     const FloatRect& casterRect = shadowLayer.geometry.boundaries;
 
     // crop used to set the corner radius may be larger than the content rect. Adjust the corner
diff --git a/services/surfaceflinger/Layer.h b/services/surfaceflinger/Layer.h
index ffe004f..6acf5fb 100644
--- a/services/surfaceflinger/Layer.h
+++ b/services/surfaceflinger/Layer.h
@@ -527,10 +527,10 @@
     void latchCompositionState(compositionengine::LayerFECompositionState&,
                                compositionengine::LayerFE::StateSubset subset) const override;
     void latchCursorCompositionState(compositionengine::LayerFECompositionState&) const override;
-    std::optional<renderengine::LayerSettings> prepareClientComposition(
+    std::optional<LayerSettings> prepareClientComposition(
             compositionengine::LayerFE::ClientCompositionTargetSettings&) override;
-    std::optional<renderengine::LayerSettings> prepareShadowClientComposition(
-            const renderengine::LayerSettings& layerSettings, const Rect& displayViewport,
+    std::optional<LayerSettings> prepareShadowClientComposition(
+            const LayerFE::LayerSettings& layerSettings, const Rect& displayViewport,
             ui::Dataspace outputDataspace) override;
     void onLayerDisplayed(const sp<Fence>& releaseFence) override;
     const char* getDebugName() const override;
diff --git a/services/surfaceflinger/SurfaceFlinger.cpp b/services/surfaceflinger/SurfaceFlinger.cpp
index 1b1b58b..a894005 100644
--- a/services/surfaceflinger/SurfaceFlinger.cpp
+++ b/services/surfaceflinger/SurfaceFlinger.cpp
@@ -353,6 +353,9 @@
     property_get("debug.sf.luma_sampling", value, "1");
     mLumaSampling = atoi(value);
 
+    property_get("debug.sf.disable_client_composition_cache", value, "1");
+    mDisableClientCompositionCache = atoi(value);
+
     // We should be reading 'persist.sys.sf.color_saturation' here
     // but since /data may be encrypted, we need to wait until after vold
     // comes online to attempt to read the property. The property is
@@ -1893,13 +1896,19 @@
     mHadClientComposition =
             std::any_of(mDisplays.cbegin(), mDisplays.cend(), [](const auto& tokenDisplayPair) {
                 auto& displayDevice = tokenDisplayPair.second;
-                return displayDevice->getCompositionDisplay()->getState().usesClientComposition;
+                return displayDevice->getCompositionDisplay()->getState().usesClientComposition &&
+                        !displayDevice->getCompositionDisplay()->getState().reusedClientComposition;
             });
     mHadDeviceComposition =
             std::any_of(mDisplays.cbegin(), mDisplays.cend(), [](const auto& tokenDisplayPair) {
                 auto& displayDevice = tokenDisplayPair.second;
                 return displayDevice->getCompositionDisplay()->getState().usesDeviceComposition;
             });
+    mReusedClientComposition =
+            std::any_of(mDisplays.cbegin(), mDisplays.cend(), [](const auto& tokenDisplayPair) {
+                auto& displayDevice = tokenDisplayPair.second;
+                return displayDevice->getCompositionDisplay()->getState().reusedClientComposition;
+            });
 
     mVSyncModulator->onRefreshed(mHadClientComposition);
 
@@ -2079,6 +2088,10 @@
         mTimeStats->incrementClientCompositionFrames();
     }
 
+    if (mReusedClientComposition) {
+        mTimeStats->incrementClientCompositionReusedFrames();
+    }
+
     mTimeStats->setPresentFenceGlobal(presentFenceTime);
 
     if (displayDevice && getHwComposer().isConnected(*displayDevice->getId()) &&
@@ -5408,7 +5421,7 @@
     const auto& displayViewport = renderArea.getDisplayViewport();
 
     renderengine::DisplaySettings clientCompositionDisplay;
-    std::vector<renderengine::LayerSettings> clientCompositionLayers;
+    std::vector<compositionengine::LayerFE::LayerSettings> clientCompositionLayers;
 
     // assume that bounds are never offset, and that they are the same as the
     // buffer bounds.
@@ -5469,7 +5482,7 @@
 
     const float alpha = RenderArea::getCaptureFillValue(renderArea.getCaptureFill());
 
-    renderengine::LayerSettings fillLayer;
+    compositionengine::LayerFE::LayerSettings fillLayer;
     fillLayer.source.buffer.buffer = nullptr;
     fillLayer.source.solidColor = half3(0.0, 0.0, 0.0);
     fillLayer.geometry.boundaries = FloatRect(0.0, 0.0, 1.0, 1.0);
@@ -5490,7 +5503,7 @@
         };
         auto result = layer->prepareClientComposition(targetSettings);
         if (result) {
-            std::optional<renderengine::LayerSettings> shadowLayer =
+            std::optional<compositionengine::LayerFE::LayerSettings> shadowLayer =
                     layer->prepareShadowClientComposition(*result, displayViewport,
                                                           clientCompositionDisplay.outputDataspace);
             if (shadowLayer) {
@@ -5500,13 +5513,20 @@
         }
     });
 
+    std::vector<const renderengine::LayerSettings*> clientCompositionLayerPointers;
+    clientCompositionLayers.reserve(clientCompositionLayers.size());
+    std::transform(clientCompositionLayers.begin(), clientCompositionLayers.end(),
+                   std::back_inserter(clientCompositionLayerPointers),
+                   [](compositionengine::LayerFE::LayerSettings& settings)
+                           -> renderengine::LayerSettings* { return &settings; });
+
     clientCompositionDisplay.clearRegion = clearRegion;
     // Use an empty fence for the buffer fence, since we just created the buffer so
     // there is no need for synchronization with the GPU.
     base::unique_fd bufferFence;
     base::unique_fd drawFence;
     getRenderEngine().useProtectedContext(false);
-    getRenderEngine().drawLayers(clientCompositionDisplay, clientCompositionLayers, buffer,
+    getRenderEngine().drawLayers(clientCompositionDisplay, clientCompositionLayerPointers, buffer,
                                  /*useFramebufferCache=*/false, std::move(bufferFence), &drawFence);
 
     *outSyncFd = drawFence.release();
diff --git a/services/surfaceflinger/SurfaceFlinger.h b/services/surfaceflinger/SurfaceFlinger.h
index 7f7d8da..f8980a5 100644
--- a/services/surfaceflinger/SurfaceFlinger.h
+++ b/services/surfaceflinger/SurfaceFlinger.h
@@ -323,6 +323,10 @@
     // Inherit from ClientCache::ErasedRecipient
     void bufferErased(const client_cache_t& clientCacheId) override;
 
+    // If set, disables reusing client composition buffers. This can be set by
+    // debug.sf.disable_client_composition_cache
+    bool mDisableClientCompositionCache = false;
+
 private:
     friend class BufferLayer;
     friend class BufferQueueLayer;
@@ -987,6 +991,10 @@
     // Note that it is possible for a frame to be composed via both client and device
     // composition, for example in the case of overlays.
     bool mHadDeviceComposition = false;
+    // True if in the previous frame, the client composition was skipped by reusing the buffer
+    // used in a previous composition. This can happed if the client composition requests
+    // did not change.
+    bool mReusedClientComposition = false;
 
     enum class BootStage {
         BOOTLOADER,
diff --git a/services/surfaceflinger/TimeStats/TimeStats.cpp b/services/surfaceflinger/TimeStats/TimeStats.cpp
index 44a59fd..c793941 100644
--- a/services/surfaceflinger/TimeStats/TimeStats.cpp
+++ b/services/surfaceflinger/TimeStats/TimeStats.cpp
@@ -155,6 +155,15 @@
     mTimeStats.clientCompositionFrames++;
 }
 
+void TimeStats::incrementClientCompositionReusedFrames() {
+    if (!mEnabled.load()) return;
+
+    ATRACE_CALL();
+
+    std::lock_guard<std::mutex> lock(mMutex);
+    mTimeStats.clientCompositionReusedFrames++;
+}
+
 static int32_t msBetween(nsecs_t start, nsecs_t end) {
     int64_t delta = std::chrono::duration_cast<std::chrono::milliseconds>(
                             std::chrono::nanoseconds(end - start))
@@ -666,6 +675,7 @@
     mTimeStats.totalFrames = 0;
     mTimeStats.missedFrames = 0;
     mTimeStats.clientCompositionFrames = 0;
+    mTimeStats.clientCompositionReusedFrames = 0;
     mTimeStats.displayOnTime = 0;
     mTimeStats.presentToPresent.hist.clear();
     mTimeStats.frameDuration.hist.clear();
diff --git a/services/surfaceflinger/TimeStats/TimeStats.h b/services/surfaceflinger/TimeStats/TimeStats.h
index 5cd421c..4e3ea20 100644
--- a/services/surfaceflinger/TimeStats/TimeStats.h
+++ b/services/surfaceflinger/TimeStats/TimeStats.h
@@ -51,6 +51,7 @@
     virtual void incrementTotalFrames() = 0;
     virtual void incrementMissedFrames() = 0;
     virtual void incrementClientCompositionFrames() = 0;
+    virtual void incrementClientCompositionReusedFrames() = 0;
 
     // Records the start and end times for a frame.
     // The start time is the same as the beginning of a SurfaceFlinger
@@ -178,6 +179,7 @@
     void incrementTotalFrames() override;
     void incrementMissedFrames() override;
     void incrementClientCompositionFrames() override;
+    void incrementClientCompositionReusedFrames() override;
 
     void recordFrameDuration(nsecs_t startTime, nsecs_t endTime) override;
     void recordRenderEngineDuration(nsecs_t startTime, nsecs_t endTime) override;
diff --git a/services/surfaceflinger/TimeStats/timestatsproto/TimeStatsHelper.cpp b/services/surfaceflinger/TimeStats/timestatsproto/TimeStatsHelper.cpp
index 7e43880..0ba90e2 100644
--- a/services/surfaceflinger/TimeStats/timestatsproto/TimeStatsHelper.cpp
+++ b/services/surfaceflinger/TimeStats/timestatsproto/TimeStatsHelper.cpp
@@ -102,6 +102,7 @@
     StringAppendF(&result, "totalFrames = %d\n", totalFrames);
     StringAppendF(&result, "missedFrames = %d\n", missedFrames);
     StringAppendF(&result, "clientCompositionFrames = %d\n", clientCompositionFrames);
+    StringAppendF(&result, "clientCompositionReusedFrames = %d\n", clientCompositionReusedFrames);
     StringAppendF(&result, "displayOnTime = %" PRId64 " ms\n", displayOnTime);
     StringAppendF(&result, "displayConfigStats is as below:\n");
     for (const auto& [fps, duration] : refreshRateStats) {
diff --git a/services/surfaceflinger/TimeStats/timestatsproto/include/timestatsproto/TimeStatsHelper.h b/services/surfaceflinger/TimeStats/timestatsproto/include/timestatsproto/TimeStatsHelper.h
index bd97ecc..702c50e 100644
--- a/services/surfaceflinger/TimeStats/timestatsproto/include/timestatsproto/TimeStatsHelper.h
+++ b/services/surfaceflinger/TimeStats/timestatsproto/include/timestatsproto/TimeStatsHelper.h
@@ -59,6 +59,7 @@
         int32_t totalFrames = 0;
         int32_t missedFrames = 0;
         int32_t clientCompositionFrames = 0;
+        int32_t clientCompositionReusedFrames = 0;
         int64_t displayOnTime = 0;
         Histogram presentToPresent;
         Histogram frameDuration;
diff --git a/services/surfaceflinger/tests/unittests/CompositionTest.cpp b/services/surfaceflinger/tests/unittests/CompositionTest.cpp
index 8a762d4..98cc023 100644
--- a/services/surfaceflinger/tests/unittests/CompositionTest.cpp
+++ b/services/surfaceflinger/tests/unittests/CompositionTest.cpp
@@ -328,8 +328,9 @@
         EXPECT_CALL(*test->mRenderEngine, drawLayers)
                 .WillRepeatedly(
                         [](const renderengine::DisplaySettings& displaySettings,
-                           const std::vector<renderengine::LayerSettings>&, ANativeWindowBuffer*,
-                           const bool, base::unique_fd&&, base::unique_fd*) -> status_t {
+                           const std::vector<const renderengine::LayerSettings*>&,
+                           ANativeWindowBuffer*, const bool, base::unique_fd&&,
+                           base::unique_fd*) -> status_t {
                             EXPECT_EQ(DEFAULT_DISPLAY_MAX_LUMINANCE, displaySettings.maxLuminance);
                             EXPECT_EQ(Rect(DEFAULT_DISPLAY_WIDTH, DEFAULT_DISPLAY_HEIGHT),
                                       displaySettings.physicalDisplay);
@@ -377,8 +378,9 @@
         EXPECT_CALL(*test->mRenderEngine, drawLayers)
                 .WillRepeatedly(
                         [](const renderengine::DisplaySettings& displaySettings,
-                           const std::vector<renderengine::LayerSettings>&, ANativeWindowBuffer*,
-                           const bool, base::unique_fd&&, base::unique_fd*) -> status_t {
+                           const std::vector<const renderengine::LayerSettings*>&,
+                           ANativeWindowBuffer*, const bool, base::unique_fd&&,
+                           base::unique_fd*) -> status_t {
                             EXPECT_EQ(DEFAULT_DISPLAY_MAX_LUMINANCE, displaySettings.maxLuminance);
                             EXPECT_EQ(Rect(DEFAULT_DISPLAY_WIDTH, DEFAULT_DISPLAY_HEIGHT),
                                       displaySettings.physicalDisplay);
@@ -627,7 +629,7 @@
     static void setupREBufferCompositionCommonCallExpectations(CompositionTest* test) {
         EXPECT_CALL(*test->mRenderEngine, drawLayers)
                 .WillOnce([](const renderengine::DisplaySettings& displaySettings,
-                             const std::vector<renderengine::LayerSettings>& layerSettings,
+                             const std::vector<const renderengine::LayerSettings*>& layerSettings,
                              ANativeWindowBuffer*, const bool, base::unique_fd&&,
                              base::unique_fd*) -> status_t {
                     EXPECT_EQ(DEFAULT_DISPLAY_MAX_LUMINANCE, displaySettings.maxLuminance);
@@ -643,16 +645,16 @@
                                          "verification lambda";
                         return NO_ERROR;
                     }
-                    renderengine::LayerSettings layer = layerSettings.back();
-                    EXPECT_THAT(layer.source.buffer.buffer, Not(IsNull()));
-                    EXPECT_THAT(layer.source.buffer.fence, Not(IsNull()));
-                    EXPECT_EQ(DEFAULT_TEXTURE_ID, layer.source.buffer.textureName);
-                    EXPECT_EQ(false, layer.source.buffer.isY410BT2020);
-                    EXPECT_EQ(true, layer.source.buffer.usePremultipliedAlpha);
-                    EXPECT_EQ(false, layer.source.buffer.isOpaque);
-                    EXPECT_EQ(0.0, layer.geometry.roundedCornersRadius);
-                    EXPECT_EQ(ui::Dataspace::UNKNOWN, layer.sourceDataspace);
-                    EXPECT_EQ(LayerProperties::COLOR[3], layer.alpha);
+                    const renderengine::LayerSettings* layer = layerSettings.back();
+                    EXPECT_THAT(layer->source.buffer.buffer, Not(IsNull()));
+                    EXPECT_THAT(layer->source.buffer.fence, Not(IsNull()));
+                    EXPECT_EQ(DEFAULT_TEXTURE_ID, layer->source.buffer.textureName);
+                    EXPECT_EQ(false, layer->source.buffer.isY410BT2020);
+                    EXPECT_EQ(true, layer->source.buffer.usePremultipliedAlpha);
+                    EXPECT_EQ(false, layer->source.buffer.isOpaque);
+                    EXPECT_EQ(0.0, layer->geometry.roundedCornersRadius);
+                    EXPECT_EQ(ui::Dataspace::UNKNOWN, layer->sourceDataspace);
+                    EXPECT_EQ(LayerProperties::COLOR[3], layer->alpha);
                     return NO_ERROR;
                 });
     }
@@ -676,7 +678,7 @@
     static void setupREColorCompositionCallExpectations(CompositionTest* test) {
         EXPECT_CALL(*test->mRenderEngine, drawLayers)
                 .WillOnce([](const renderengine::DisplaySettings& displaySettings,
-                             const std::vector<renderengine::LayerSettings>& layerSettings,
+                             const std::vector<const renderengine::LayerSettings*>& layerSettings,
                              ANativeWindowBuffer*, const bool, base::unique_fd&&,
                              base::unique_fd*) -> status_t {
                     EXPECT_EQ(DEFAULT_DISPLAY_MAX_LUMINANCE, displaySettings.maxLuminance);
@@ -692,14 +694,14 @@
                                    "setupREColorCompositionCallExpectations verification lambda";
                         return NO_ERROR;
                     }
-                    renderengine::LayerSettings layer = layerSettings.back();
-                    EXPECT_THAT(layer.source.buffer.buffer, IsNull());
+                    const renderengine::LayerSettings* layer = layerSettings.back();
+                    EXPECT_THAT(layer->source.buffer.buffer, IsNull());
                     EXPECT_EQ(half3(LayerProperties::COLOR[0], LayerProperties::COLOR[1],
                                     LayerProperties::COLOR[2]),
-                              layer.source.solidColor);
-                    EXPECT_EQ(0.0, layer.geometry.roundedCornersRadius);
-                    EXPECT_EQ(ui::Dataspace::UNKNOWN, layer.sourceDataspace);
-                    EXPECT_EQ(LayerProperties::COLOR[3], layer.alpha);
+                              layer->source.solidColor);
+                    EXPECT_EQ(0.0, layer->geometry.roundedCornersRadius);
+                    EXPECT_EQ(ui::Dataspace::UNKNOWN, layer->sourceDataspace);
+                    EXPECT_EQ(LayerProperties::COLOR[3], layer->alpha);
                     return NO_ERROR;
                 });
     }
@@ -752,7 +754,7 @@
     static void setupInsecureREBufferCompositionCommonCallExpectations(CompositionTest* test) {
         EXPECT_CALL(*test->mRenderEngine, drawLayers)
                 .WillOnce([](const renderengine::DisplaySettings& displaySettings,
-                             const std::vector<renderengine::LayerSettings>& layerSettings,
+                             const std::vector<const renderengine::LayerSettings*>& layerSettings,
                              ANativeWindowBuffer*, const bool, base::unique_fd&&,
                              base::unique_fd*) -> status_t {
                     EXPECT_EQ(DEFAULT_DISPLAY_MAX_LUMINANCE, displaySettings.maxLuminance);
@@ -768,12 +770,12 @@
                                          "verification lambda";
                         return NO_ERROR;
                     }
-                    renderengine::LayerSettings layer = layerSettings.back();
-                    EXPECT_THAT(layer.source.buffer.buffer, IsNull());
-                    EXPECT_EQ(half3(0.0f, 0.0f, 0.0f), layer.source.solidColor);
-                    EXPECT_EQ(0.0, layer.geometry.roundedCornersRadius);
-                    EXPECT_EQ(ui::Dataspace::UNKNOWN, layer.sourceDataspace);
-                    EXPECT_EQ(1.0f, layer.alpha);
+                    const renderengine::LayerSettings* layer = layerSettings.back();
+                    EXPECT_THAT(layer->source.buffer.buffer, IsNull());
+                    EXPECT_EQ(half3(0.0f, 0.0f, 0.0f), layer->source.solidColor);
+                    EXPECT_EQ(0.0, layer->geometry.roundedCornersRadius);
+                    EXPECT_EQ(ui::Dataspace::UNKNOWN, layer->sourceDataspace);
+                    EXPECT_EQ(1.0f, layer->alpha);
                     return NO_ERROR;
                 });
     }
diff --git a/services/surfaceflinger/tests/unittests/TimeStatsTest.cpp b/services/surfaceflinger/tests/unittests/TimeStatsTest.cpp
index c667080..7a834a2 100644
--- a/services/surfaceflinger/tests/unittests/TimeStatsTest.cpp
+++ b/services/surfaceflinger/tests/unittests/TimeStatsTest.cpp
@@ -42,6 +42,7 @@
 
 using testing::_;
 using testing::Contains;
+using testing::HasSubstr;
 using testing::InSequence;
 using testing::SizeIs;
 using testing::UnorderedElementsAre;
@@ -296,6 +297,21 @@
     EXPECT_EQ(CLIENT_COMPOSITION_FRAMES, globalProto.client_composition_frames());
 }
 
+TEST_F(TimeStatsTest, canIncreaseClientCompositionReusedFrames) {
+    // this stat is not in the proto so verify by checking the string dump
+    constexpr size_t CLIENT_COMPOSITION_REUSED_FRAMES = 2;
+
+    EXPECT_TRUE(inputCommand(InputCommand::ENABLE, FMT_STRING).empty());
+    for (size_t i = 0; i < CLIENT_COMPOSITION_REUSED_FRAMES; i++) {
+        ASSERT_NO_FATAL_FAILURE(mTimeStats->incrementClientCompositionReusedFrames());
+    }
+
+    const std::string result(inputCommand(InputCommand::DUMP_ALL, FMT_STRING));
+    const std::string expectedResult =
+            "clientCompositionReusedFrames = " + std::to_string(CLIENT_COMPOSITION_REUSED_FRAMES);
+    EXPECT_THAT(result, HasSubstr(expectedResult));
+}
+
 TEST_F(TimeStatsTest, canInsertGlobalPresentToPresent) {
     EXPECT_TRUE(inputCommand(InputCommand::ENABLE, FMT_STRING).empty());
 
@@ -640,6 +656,16 @@
     EXPECT_EQ(0, globalProto.stats_size());
 }
 
+TEST_F(TimeStatsTest, canClearClientCompositionSkippedFrames) {
+    // this stat is not in the proto so verify by checking the string dump
+    EXPECT_TRUE(inputCommand(InputCommand::ENABLE, FMT_STRING).empty());
+    ASSERT_NO_FATAL_FAILURE(mTimeStats->incrementClientCompositionReusedFrames());
+    EXPECT_TRUE(inputCommand(InputCommand::CLEAR, FMT_STRING).empty());
+
+    const std::string result(inputCommand(InputCommand::DUMP_ALL, FMT_STRING));
+    EXPECT_THAT(result, HasSubstr("clientCompositionReusedFrames = 0"));
+}
+
 TEST_F(TimeStatsTest, canDumpWithMaxLayers) {
     EXPECT_TRUE(inputCommand(InputCommand::ENABLE, FMT_STRING).empty());
 
diff --git a/services/surfaceflinger/tests/unittests/mock/MockTimeStats.h b/services/surfaceflinger/tests/unittests/mock/MockTimeStats.h
index 9ada5ef..d1df08c 100644
--- a/services/surfaceflinger/tests/unittests/mock/MockTimeStats.h
+++ b/services/surfaceflinger/tests/unittests/mock/MockTimeStats.h
@@ -35,6 +35,7 @@
     MOCK_METHOD0(incrementTotalFrames, void());
     MOCK_METHOD0(incrementMissedFrames, void());
     MOCK_METHOD0(incrementClientCompositionFrames, void());
+    MOCK_METHOD0(incrementClientCompositionReusedFrames, void());
     MOCK_METHOD2(recordFrameDuration, void(nsecs_t, nsecs_t));
     MOCK_METHOD2(recordRenderEngineDuration, void(nsecs_t, nsecs_t));
     MOCK_METHOD2(recordRenderEngineDuration, void(nsecs_t, const std::shared_ptr<FenceTime>&));