diff --git a/services/surfaceflinger/CompositionEngine/Android.bp b/services/surfaceflinger/CompositionEngine/Android.bp
index 08147ed..d738ccd 100644
--- a/services/surfaceflinger/CompositionEngine/Android.bp
+++ b/services/surfaceflinger/CompositionEngine/Android.bp
@@ -57,6 +57,7 @@
         "src/planner/LayerState.cpp",
         "src/planner/Planner.cpp",
         "src/planner/Predictor.cpp",
+        "src/planner/TexturePool.cpp",
         "src/ClientCompositionRequestCache.cpp",
         "src/CompositionEngine.cpp",
         "src/Display.cpp",
@@ -107,6 +108,7 @@
         "tests/planner/FlattenerTest.cpp",
         "tests/planner/LayerStateTest.cpp",
         "tests/planner/PredictorTest.cpp",
+        "tests/planner/TexturePoolTest.cpp",
         "tests/CompositionEngineTest.cpp",
         "tests/DisplayColorProfileTest.cpp",
         "tests/DisplayTest.cpp",
diff --git a/services/surfaceflinger/CompositionEngine/include/compositionengine/impl/planner/CachedSet.h b/services/surfaceflinger/CompositionEngine/include/compositionengine/impl/planner/CachedSet.h
index 2c18a60..a4356c5 100644
--- a/services/surfaceflinger/CompositionEngine/include/compositionengine/impl/planner/CachedSet.h
+++ b/services/surfaceflinger/CompositionEngine/include/compositionengine/impl/planner/CachedSet.h
@@ -19,6 +19,7 @@
 #include <compositionengine/Output.h>
 #include <compositionengine/ProjectionSpace.h>
 #include <compositionengine/impl/planner/LayerState.h>
+#include <compositionengine/impl/planner/TexturePool.h>
 #include <renderengine/RenderEngine.h>
 
 #include <chrono>
@@ -64,9 +65,12 @@
     size_t getLayerCount() const { return mLayers.size(); }
     const Layer& getFirstLayer() const { return mLayers[0]; }
     const Rect& getBounds() const { return mBounds; }
+    Rect getTextureBounds() const { return mOutputSpace.content; }
     const Region& getVisibleRegion() const { return mVisibleRegion; }
     size_t getAge() const { return mAge; }
-    const std::shared_ptr<renderengine::ExternalTexture>& getBuffer() const { return mTexture; }
+    std::shared_ptr<renderengine::ExternalTexture> getBuffer() const {
+        return mTexture ? mTexture->get() : nullptr;
+    }
     const sp<Fence>& getDrawFence() const { return mDrawFence; }
     const ProjectionSpace& getOutputSpace() const { return mOutputSpace; }
     ui::Dataspace getOutputDataspace() const { return mOutputDataspace; }
@@ -89,7 +93,7 @@
 
     void setLastUpdate(std::chrono::steady_clock::time_point now) { mLastUpdate = now; }
     void append(const CachedSet& other) {
-        mTexture = nullptr;
+        mTexture.reset();
         mOutputDataspace = ui::Dataspace::UNKNOWN;
         mDrawFence = nullptr;
         mBlurLayer = nullptr;
@@ -105,7 +109,8 @@
     void incrementAge() { ++mAge; }
 
     // Renders the cached set with the supplied output composition state.
-    void render(renderengine::RenderEngine& re, const OutputCompositionState& outputState);
+    void render(renderengine::RenderEngine& re, TexturePool& texturePool,
+                const OutputCompositionState& outputState);
 
     void dump(std::string& result) const;
 
@@ -151,7 +156,9 @@
     Region mVisibleRegion;
     size_t mAge = 0;
 
-    std::shared_ptr<renderengine::ExternalTexture> mTexture;
+    // TODO(b/190411067): This is a shared pointer only because CachedSets are copied into different
+    // containers in the Flattener. Logically this should have unique ownership otherwise.
+    std::shared_ptr<TexturePool::AutoTexture> mTexture;
     sp<Fence> mDrawFence;
     ProjectionSpace mOutputSpace;
     ui::Dataspace mOutputDataspace;
diff --git a/services/surfaceflinger/CompositionEngine/include/compositionengine/impl/planner/Flattener.h b/services/surfaceflinger/CompositionEngine/include/compositionengine/impl/planner/Flattener.h
index c76078d..94a169e 100644
--- a/services/surfaceflinger/CompositionEngine/include/compositionengine/impl/planner/Flattener.h
+++ b/services/surfaceflinger/CompositionEngine/include/compositionengine/impl/planner/Flattener.h
@@ -37,16 +37,18 @@
 
 class Flattener {
 public:
-    Flattener(bool enableHolePunch = false);
+    Flattener(renderengine::RenderEngine& renderEngine, bool enableHolePunch = false);
 
-    void setDisplaySize(ui::Size size) { mDisplaySize = size; }
+    void setDisplaySize(ui::Size size) {
+        mDisplaySize = size;
+        mTexturePool.setDisplaySize(size);
+    }
 
     NonBufferHash flattenLayers(const std::vector<const LayerState*>& layers, NonBufferHash,
                                 std::chrono::steady_clock::time_point now);
 
     // Renders the newest cached sets with the supplied output composition state
-    void renderCachedSets(renderengine::RenderEngine& re,
-                          const OutputCompositionState& outputState);
+    void renderCachedSets(const OutputCompositionState& outputState);
 
     void dump(std::string& result) const;
     void dumpLayers(std::string& result) const;
@@ -145,8 +147,11 @@
 
     void buildCachedSets(std::chrono::steady_clock::time_point now);
 
+    renderengine::RenderEngine& mRenderEngine;
     const bool mEnableHolePunch;
 
+    TexturePool mTexturePool;
+
     ui::Size mDisplaySize;
 
     NonBufferHash mCurrentGeometry;
diff --git a/services/surfaceflinger/CompositionEngine/include/compositionengine/impl/planner/Planner.h b/services/surfaceflinger/CompositionEngine/include/compositionengine/impl/planner/Planner.h
index 4365b93..fd1ddfc 100644
--- a/services/surfaceflinger/CompositionEngine/include/compositionengine/impl/planner/Planner.h
+++ b/services/surfaceflinger/CompositionEngine/include/compositionengine/impl/planner/Planner.h
@@ -41,7 +41,7 @@
 // as a more efficient representation of parts of the layer stack.
 class Planner {
 public:
-    Planner();
+    Planner(renderengine::RenderEngine& renderengine);
 
     void setDisplaySize(ui::Size);
 
@@ -59,8 +59,7 @@
             compositionengine::Output::OutputLayersEnumerator<compositionengine::Output>&& layers);
 
     // The planner will call to the Flattener to render any pending cached set
-    void renderCachedSets(renderengine::RenderEngine& re,
-                          const OutputCompositionState& outputState);
+    void renderCachedSets(const OutputCompositionState& outputState);
 
     void dump(const Vector<String16>& args, std::string&);
 
diff --git a/services/surfaceflinger/CompositionEngine/include/compositionengine/impl/planner/TexturePool.h b/services/surfaceflinger/CompositionEngine/include/compositionengine/impl/planner/TexturePool.h
new file mode 100644
index 0000000..fb53ee0
--- /dev/null
+++ b/services/surfaceflinger/CompositionEngine/include/compositionengine/impl/planner/TexturePool.h
@@ -0,0 +1,102 @@
+/*
+ * Copyright 2021 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 <compositionengine/Output.h>
+#include <compositionengine/ProjectionSpace.h>
+#include <compositionengine/impl/planner/LayerState.h>
+#include <renderengine/RenderEngine.h>
+
+#include <renderengine/ExternalTexture.h>
+#include <chrono>
+#include "android-base/macros.h"
+
+namespace android::compositionengine::impl::planner {
+
+// A pool of textures that only manages textures of a single size.
+// While it is possible to define a texture pool supporting variable-sized textures to save on
+// memory, it is a simpler implementation to only manage screen-sized textures. The texture pool is
+// unbounded - there are a minimum number of textures preallocated. Under heavy system load, new
+// textures may be allocated, but only a maximum number of retained once those textures are no
+// longer necessary.
+class TexturePool {
+public:
+    // RAII class helping with managing textures from the texture pool
+    // Textures once they're no longer used should be returned to the pool instead of outright
+    // deleted.
+    class AutoTexture {
+    public:
+        AutoTexture(TexturePool& texturePool,
+                    std::shared_ptr<renderengine::ExternalTexture> texture, const sp<Fence>& fence)
+              : mTexturePool(texturePool), mTexture(texture), mFence(fence) {}
+
+        ~AutoTexture() { mTexturePool.returnTexture(std::move(mTexture), mFence); }
+
+        sp<Fence> getReadyFence() { return mFence; }
+
+        void setReadyFence(const sp<Fence>& fence) { mFence = fence; }
+
+        // Disable copying and assigning
+        AutoTexture(const AutoTexture&) = delete;
+        AutoTexture& operator=(const AutoTexture&) = delete;
+
+        // Gets a pointer to the underlying external texture
+        const std::shared_ptr<renderengine::ExternalTexture>& get() const { return mTexture; }
+
+    private:
+        TexturePool& mTexturePool;
+        std::shared_ptr<renderengine::ExternalTexture> mTexture;
+        sp<Fence> mFence;
+    };
+
+    TexturePool(renderengine::RenderEngine& renderEngine) : mRenderEngine(renderEngine) {}
+
+    virtual ~TexturePool() = default;
+
+    // Sets the display size for the texture pool.
+    // This will trigger a reallocation for all remaining textures in the pool.
+    // setDisplaySize must be called for the texture pool to be used.
+    void setDisplaySize(ui::Size size);
+
+    // Borrows a new texture from the pool.
+    // If the pool is currently starved of textures, then a new texture is generated.
+    // When the AutoTexture object is destroyed, the scratch texture is automatically returned
+    // to the pool.
+    std::shared_ptr<AutoTexture> borrowTexture();
+
+protected:
+    // Proteted visibility so that they can be used for testing
+    const static constexpr size_t kMinPoolSize = 3;
+    const static constexpr size_t kMaxPoolSize = 4;
+
+    struct Entry {
+        std::shared_ptr<renderengine::ExternalTexture> texture;
+        sp<Fence> fence;
+    };
+
+    std::deque<Entry> mPool;
+
+private:
+    std::shared_ptr<renderengine::ExternalTexture> genTexture();
+    // Returns a previously borrowed texture to the pool.
+    void returnTexture(std::shared_ptr<renderengine::ExternalTexture>&& texture,
+                       const sp<Fence>& fence);
+    renderengine::RenderEngine& mRenderEngine;
+    ui::Size mSize;
+};
+
+} // namespace android::compositionengine::impl::planner
diff --git a/services/surfaceflinger/CompositionEngine/src/Output.cpp b/services/surfaceflinger/CompositionEngine/src/Output.cpp
index e9a8b91..cd2f742 100644
--- a/services/surfaceflinger/CompositionEngine/src/Output.cpp
+++ b/services/surfaceflinger/CompositionEngine/src/Output.cpp
@@ -129,7 +129,7 @@
     }
 
     if (enabled) {
-        mPlanner = std::make_unique<planner::Planner>();
+        mPlanner = std::make_unique<planner::Planner>(getCompositionEngine().getRenderEngine());
         if (mRenderSurface) {
             mPlanner->setDisplaySize(mRenderSurface->getSize());
         }
@@ -1314,7 +1314,7 @@
 
 void Output::renderCachedSets() {
     if (mPlanner) {
-        mPlanner->renderCachedSets(getCompositionEngine().getRenderEngine(), getState());
+        mPlanner->renderCachedSets(getState());
     }
 }
 
diff --git a/services/surfaceflinger/CompositionEngine/src/planner/CachedSet.cpp b/services/surfaceflinger/CompositionEngine/src/planner/CachedSet.cpp
index dcfb05d..69e8c7d 100644
--- a/services/surfaceflinger/CompositionEngine/src/planner/CachedSet.cpp
+++ b/services/surfaceflinger/CompositionEngine/src/planner/CachedSet.cpp
@@ -134,7 +134,7 @@
 }
 
 bool CachedSet::hasReadyBuffer() const {
-    return mTexture != nullptr && mDrawFence->getStatus() == Fence::Status::Signaled;
+    return mTexture && mDrawFence->getStatus() == Fence::Status::Signaled;
 }
 
 std::vector<CachedSet> CachedSet::decompose() const {
@@ -156,7 +156,7 @@
     }
 }
 
-void CachedSet::render(renderengine::RenderEngine& renderEngine,
+void CachedSet::render(renderengine::RenderEngine& renderEngine, TexturePool& texturePool,
                        const OutputCompositionState& outputState) {
     ATRACE_CALL();
     const Rect& viewport = outputState.layerStackSpace.content;
@@ -165,10 +165,7 @@
             ui::Transform::toRotationFlags(outputState.framebufferSpace.orientation);
 
     renderengine::DisplaySettings displaySettings{
-            .physicalDisplay = Rect(-mBounds.left + outputState.framebufferSpace.content.left,
-                                    -mBounds.top + outputState.framebufferSpace.content.top,
-                                    -mBounds.left + outputState.framebufferSpace.content.right,
-                                    -mBounds.top + outputState.framebufferSpace.content.bottom),
+            .physicalDisplay = outputState.framebufferSpace.content,
             .clip = viewport,
             .outputDataspace = outputDataspace,
             .orientation = orientation,
@@ -255,30 +252,33 @@
         layerSettingsPointers.emplace_back(&highlight);
     }
 
-    const uint64_t usageFlags = GraphicBuffer::USAGE_HW_RENDER | GraphicBuffer::USAGE_HW_COMPOSER |
-            GraphicBuffer::USAGE_HW_TEXTURE;
-    sp<GraphicBuffer> buffer = new GraphicBuffer(static_cast<uint32_t>(mBounds.getWidth()),
-                                                 static_cast<uint32_t>(mBounds.getHeight()),
-                                                 HAL_PIXEL_FORMAT_RGBA_8888, 1, usageFlags);
-    const auto texture = std::make_shared<
-            renderengine::ExternalTexture>(buffer, renderEngine,
-                                           renderengine::ExternalTexture::Usage::READABLE |
-                                                   renderengine::ExternalTexture::Usage::WRITEABLE);
-    LOG_ALWAYS_FATAL_IF(buffer->initCheck() != OK);
-    base::unique_fd drawFence;
+    auto texture = texturePool.borrowTexture();
+    LOG_ALWAYS_FATAL_IF(texture->get()->getBuffer()->initCheck() != OK);
 
-    status_t result = renderEngine.drawLayers(displaySettings, layerSettingsPointers, texture,
-                                              false, base::unique_fd(), &drawFence);
+    base::unique_fd bufferFence;
+    if (texture->getReadyFence()) {
+        // Bail out if the buffer is not ready, because there is some pending GPU work left.
+        if (texture->getReadyFence()->getStatus() != Fence::Status::Signaled) {
+            return;
+        }
+        bufferFence.reset(texture->getReadyFence()->dup());
+    }
+
+    base::unique_fd drawFence;
+    status_t result =
+            renderEngine.drawLayers(displaySettings, layerSettingsPointers, texture->get(), false,
+                                    std::move(bufferFence), &drawFence);
 
     if (result == NO_ERROR) {
         mDrawFence = new Fence(drawFence.release());
         mOutputSpace = outputState.framebufferSpace;
-        mTexture = std::move(texture);
+        mTexture = texture;
+        mTexture->setReadyFence(mDrawFence);
         mOutputSpace.orientation = outputState.framebufferSpace.orientation;
         mOutputDataspace = outputDataspace;
         mOrientation = orientation;
     } else {
-        mTexture = nullptr;
+        mTexture.reset();
     }
 }
 
@@ -363,7 +363,7 @@
     base::StringAppendF(&result, "  + Fingerprint %016zx, last update %sago, age %zd\n",
                         mFingerprint, durationString(lastUpdate).c_str(), mAge);
     {
-        const auto b = mTexture ? mTexture->getBuffer().get() : nullptr;
+        const auto b = mTexture ? mTexture->get()->getBuffer().get() : nullptr;
         base::StringAppendF(&result, "    Override buffer: %p\n", b);
     }
     base::StringAppendF(&result, "    HolePunchLayer: %p\n", mHolePunchLayer);
diff --git a/services/surfaceflinger/CompositionEngine/src/planner/Flattener.cpp b/services/surfaceflinger/CompositionEngine/src/planner/Flattener.cpp
index 48fb51f..192c411 100644
--- a/services/surfaceflinger/CompositionEngine/src/planner/Flattener.cpp
+++ b/services/surfaceflinger/CompositionEngine/src/planner/Flattener.cpp
@@ -60,7 +60,10 @@
 
 } // namespace
 
-Flattener::Flattener(bool enableHolePunch) : mEnableHolePunch(enableHolePunch) {
+Flattener::Flattener(renderengine::RenderEngine& renderEngine, bool enableHolePunch)
+      : mRenderEngine(renderEngine),
+        mEnableHolePunch(enableHolePunch),
+        mTexturePool(mRenderEngine) {
     const int timeoutInMs =
             base::GetIntProperty(std::string("debug.sf.layer_caching_active_layer_timeout_ms"), 0);
     if (timeoutInMs != 0) {
@@ -102,14 +105,13 @@
     return hash;
 }
 
-void Flattener::renderCachedSets(renderengine::RenderEngine& renderEngine,
-                                 const OutputCompositionState& outputState) {
+void Flattener::renderCachedSets(const OutputCompositionState& outputState) {
     ATRACE_CALL();
     if (!mNewCachedSet || mNewCachedSet->hasRenderedBuffer()) {
         return;
     }
 
-    mNewCachedSet->render(renderEngine, outputState);
+    mNewCachedSet->render(mRenderEngine, mTexturePool, outputState);
 }
 
 void Flattener::dumpLayers(std::string& result) const {
@@ -285,7 +287,7 @@
                         state.overrideInfo = {
                                 .buffer = mNewCachedSet->getBuffer(),
                                 .acquireFence = mNewCachedSet->getDrawFence(),
-                                .displayFrame = mNewCachedSet->getBounds(),
+                                .displayFrame = mNewCachedSet->getTextureBounds(),
                                 .dataspace = mNewCachedSet->getOutputDataspace(),
                                 .displaySpace = mNewCachedSet->getOutputSpace(),
                                 .damageRegion = Region::INVALID_REGION,
@@ -325,7 +327,7 @@
                 state.overrideInfo = {
                         .buffer = currentLayerIter->getBuffer(),
                         .acquireFence = currentLayerIter->getDrawFence(),
-                        .displayFrame = currentLayerIter->getBounds(),
+                        .displayFrame = currentLayerIter->getTextureBounds(),
                         .dataspace = currentLayerIter->getOutputDataspace(),
                         .displaySpace = currentLayerIter->getOutputSpace(),
                         .damageRegion = Region(),
diff --git a/services/surfaceflinger/CompositionEngine/src/planner/Planner.cpp b/services/surfaceflinger/CompositionEngine/src/planner/Planner.cpp
index 297c0b2..711a634 100644
--- a/services/surfaceflinger/CompositionEngine/src/planner/Planner.cpp
+++ b/services/surfaceflinger/CompositionEngine/src/planner/Planner.cpp
@@ -29,12 +29,13 @@
 
 namespace android::compositionengine::impl::planner {
 
-Planner::Planner()
+Planner::Planner(renderengine::RenderEngine& renderEngine)
       // Implicitly, layer caching must also be enabled for the hole punch or
       // predictor to have any effect.
       // E.g., setprop debug.sf.enable_layer_caching 1, or
       // adb shell service call SurfaceFlinger 1040 i32 1 [i64 <display ID>]
-      : mFlattener(base::GetBoolProperty(std::string("debug.sf.enable_hole_punch_pip"), true)) {
+      : mFlattener(renderEngine,
+                   base::GetBoolProperty(std::string("debug.sf.enable_hole_punch_pip"), true)) {
     mPredictorEnabled =
             base::GetBoolProperty(std::string("debug.sf.enable_planner_prediction"), false);
 }
@@ -160,10 +161,9 @@
                             finalPlan);
 }
 
-void Planner::renderCachedSets(renderengine::RenderEngine& renderEngine,
-                               const OutputCompositionState& outputState) {
+void Planner::renderCachedSets(const OutputCompositionState& outputState) {
     ATRACE_CALL();
-    mFlattener.renderCachedSets(renderEngine, outputState);
+    mFlattener.renderCachedSets(outputState);
 }
 
 void Planner::dump(const Vector<String16>& args, std::string& result) {
diff --git a/services/surfaceflinger/CompositionEngine/src/planner/TexturePool.cpp b/services/surfaceflinger/CompositionEngine/src/planner/TexturePool.cpp
new file mode 100644
index 0000000..e3772a2
--- /dev/null
+++ b/services/surfaceflinger/CompositionEngine/src/planner/TexturePool.cpp
@@ -0,0 +1,84 @@
+/*
+ * Copyright 2021 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.
+ */
+
+// #define LOG_NDEBUG 0
+
+#undef LOG_TAG
+#define LOG_TAG "Planner"
+
+#include <compositionengine/impl/planner/TexturePool.h>
+#include <utils/Log.h>
+
+namespace android::compositionengine::impl::planner {
+
+void TexturePool::setDisplaySize(ui::Size size) {
+    if (mSize == size) {
+        return;
+    }
+    mSize = size;
+    mPool.clear();
+    mPool.resize(kMinPoolSize);
+    std::generate_n(mPool.begin(), kMinPoolSize, [&]() { return Entry{genTexture(), nullptr}; });
+}
+
+std::shared_ptr<TexturePool::AutoTexture> TexturePool::borrowTexture() {
+    if (mPool.empty()) {
+        return std::make_shared<AutoTexture>(*this, genTexture(), nullptr);
+    }
+
+    const auto entry = mPool.front();
+    mPool.pop_front();
+    return std::make_shared<AutoTexture>(*this, entry.texture, entry.fence);
+}
+
+void TexturePool::returnTexture(std::shared_ptr<renderengine::ExternalTexture>&& texture,
+                                const sp<Fence>& fence) {
+    // Drop the texture on the floor if the pool is no longer tracking textures of the same size.
+    if (static_cast<int32_t>(texture->getBuffer()->getWidth()) != mSize.getWidth() ||
+        static_cast<int32_t>(texture->getBuffer()->getHeight()) != mSize.getHeight()) {
+        ALOGV("Deallocating texture from Planner's pool - display size changed (previous: (%dx%d), "
+              "current: (%dx%d))",
+              texture->getBuffer()->getWidth(), texture->getBuffer()->getHeight(), mSize.getWidth(),
+              mSize.getHeight());
+        return;
+    }
+
+    // Also ensure the pool does not grow beyond a maximum size.
+    if (mPool.size() == kMaxPoolSize) {
+        ALOGD("Deallocating texture from Planner's pool - max size [%" PRIu64 "] reached",
+              static_cast<uint64_t>(kMaxPoolSize));
+        return;
+    }
+
+    mPool.push_back({std::move(texture), fence});
+}
+
+std::shared_ptr<renderengine::ExternalTexture> TexturePool::genTexture() {
+    LOG_ALWAYS_FATAL_IF(!mSize.isValid(), "Attempted to generate texture with invalid size");
+    return std::make_shared<
+            renderengine::ExternalTexture>(sp<GraphicBuffer>::
+                                                   make(mSize.getWidth(), mSize.getHeight(),
+                                                        HAL_PIXEL_FORMAT_RGBA_8888, 1,
+                                                        GraphicBuffer::USAGE_HW_RENDER |
+                                                                GraphicBuffer::USAGE_HW_COMPOSER |
+                                                                GraphicBuffer::USAGE_HW_TEXTURE,
+                                                        "Planner"),
+                                           mRenderEngine,
+                                           renderengine::ExternalTexture::Usage::READABLE |
+                                                   renderengine::ExternalTexture::Usage::WRITEABLE);
+}
+
+} // namespace android::compositionengine::impl::planner
\ No newline at end of file
diff --git a/services/surfaceflinger/CompositionEngine/tests/OutputTest.cpp b/services/surfaceflinger/CompositionEngine/tests/OutputTest.cpp
index 52e0428..c381081 100644
--- a/services/surfaceflinger/CompositionEngine/tests/OutputTest.cpp
+++ b/services/surfaceflinger/CompositionEngine/tests/OutputTest.cpp
@@ -143,6 +143,7 @@
         mOutput->setRenderSurfaceForTest(std::unique_ptr<RenderSurface>(mRenderSurface));
 
         mOutput->editState().displaySpace.bounds = kDefaultDisplaySize;
+        EXPECT_CALL(mCompositionEngine, getRenderEngine()).WillRepeatedly(ReturnRef(mRenderEngine));
     }
 
     void injectOutputLayer(InjectedLayer& layer) {
@@ -156,6 +157,7 @@
     static const Rect kDefaultDisplaySize;
 
     StrictMock<mock::CompositionEngine> mCompositionEngine;
+    StrictMock<renderengine::mock::RenderEngine> mRenderEngine;
     mock::DisplayColorProfile* mDisplayColorProfile = new StrictMock<mock::DisplayColorProfile>();
     mock::RenderSurface* mRenderSurface = new StrictMock<mock::RenderSurface>();
     std::shared_ptr<Output> mOutput = createOutput(mCompositionEngine);
diff --git a/services/surfaceflinger/CompositionEngine/tests/planner/CachedSetTest.cpp b/services/surfaceflinger/CompositionEngine/tests/planner/CachedSetTest.cpp
index 8eeb0bf..b15e4f3 100644
--- a/services/surfaceflinger/CompositionEngine/tests/planner/CachedSetTest.cpp
+++ b/services/surfaceflinger/CompositionEngine/tests/planner/CachedSetTest.cpp
@@ -40,6 +40,7 @@
 using impl::planner::CachedSet;
 using impl::planner::LayerState;
 using impl::planner::LayerStateField;
+using impl::planner::TexturePool;
 
 namespace {
 
@@ -50,6 +51,7 @@
 
     return expectedBlurSetting == arg.blurSetting;
 }
+static const ui::Size kOutputSize = ui::Size(1, 1);
 
 class CachedSetTest : public testing::Test {
 public:
@@ -76,9 +78,11 @@
     impl::OutputCompositionState mOutputState;
 
     android::renderengine::mock::RenderEngine mRenderEngine;
+    TexturePool mTexturePool = TexturePool(mRenderEngine);
 };
 
 void CachedSetTest::SetUp() {
+    mTexturePool.setDisplaySize(kOutputSize);
     for (size_t i = 0; i < kNumLayers; i++) {
         auto testLayer = std::make_unique<TestLayer>();
         auto pos = static_cast<int32_t>(i);
@@ -319,7 +323,7 @@
                                 const std::vector<const renderengine::LayerSettings*>& layers,
                                 const std::shared_ptr<renderengine::ExternalTexture>&, const bool,
                                 base::unique_fd&&, base::unique_fd*) -> size_t {
-        EXPECT_EQ(Rect(-1, -1, 9, 4), displaySettings.physicalDisplay);
+        EXPECT_EQ(mOutputState.framebufferSpace.content, displaySettings.physicalDisplay);
         EXPECT_EQ(mOutputState.layerStackSpace.content, displaySettings.clip);
         EXPECT_EQ(ui::Transform::toRotationFlags(mOutputState.framebufferSpace.orientation),
                   displaySettings.orientation);
@@ -333,10 +337,11 @@
     EXPECT_CALL(*layerFE1, prepareClientCompositionList(_)).WillOnce(Return(clientCompList1));
     EXPECT_CALL(*layerFE2, prepareClientCompositionList(_)).WillOnce(Return(clientCompList2));
     EXPECT_CALL(mRenderEngine, drawLayers(_, _, _, _, _, _)).WillOnce(Invoke(drawLayers));
-    cachedSet.render(mRenderEngine, mOutputState);
+    cachedSet.render(mRenderEngine, mTexturePool, mOutputState);
     expectReadyBuffer(cachedSet);
 
     EXPECT_EQ(mOutputState.framebufferSpace, cachedSet.getOutputSpace());
+    EXPECT_EQ(mOutputState.framebufferSpace.content, cachedSet.getTextureBounds());
 
     // Now check that appending a new cached set properly cleans up RenderEngine resources.
     CachedSet::Layer& layer3 = *mTestLayers[2]->cachedSetLayer.get();
@@ -367,7 +372,7 @@
                                 const std::vector<const renderengine::LayerSettings*>& layers,
                                 const std::shared_ptr<renderengine::ExternalTexture>&, const bool,
                                 base::unique_fd&&, base::unique_fd*) -> size_t {
-        EXPECT_EQ(Rect(1, 2, 9, 4), displaySettings.physicalDisplay);
+        EXPECT_EQ(mOutputState.framebufferSpace.content, displaySettings.physicalDisplay);
         EXPECT_EQ(mOutputState.layerStackSpace.content, displaySettings.clip);
         EXPECT_EQ(ui::Transform::toRotationFlags(mOutputState.framebufferSpace.orientation),
                   displaySettings.orientation);
@@ -381,7 +386,7 @@
     EXPECT_CALL(*layerFE1, prepareClientCompositionList(_)).WillOnce(Return(clientCompList1));
     EXPECT_CALL(*layerFE2, prepareClientCompositionList(_)).WillOnce(Return(clientCompList2));
     EXPECT_CALL(mRenderEngine, drawLayers(_, _, _, _, _, _)).WillOnce(Invoke(drawLayers));
-    cachedSet.render(mRenderEngine, mOutputState);
+    cachedSet.render(mRenderEngine, mTexturePool, mOutputState);
     expectReadyBuffer(cachedSet);
 
     EXPECT_EQ(mOutputState.framebufferSpace, cachedSet.getOutputSpace());
@@ -554,7 +559,7 @@
     };
 
     EXPECT_CALL(mRenderEngine, drawLayers(_, _, _, _, _, _)).WillOnce(Invoke(drawLayers));
-    cachedSet.render(mRenderEngine, mOutputState);
+    cachedSet.render(mRenderEngine, mTexturePool, mOutputState);
 }
 
 TEST_F(CachedSetTest, addHolePunch_noBuffer) {
@@ -604,7 +609,7 @@
     };
 
     EXPECT_CALL(mRenderEngine, drawLayers(_, _, _, _, _, _)).WillOnce(Invoke(drawLayers));
-    cachedSet.render(mRenderEngine, mOutputState);
+    cachedSet.render(mRenderEngine, mTexturePool, mOutputState);
 }
 
 TEST_F(CachedSetTest, append_removesHolePunch) {
@@ -741,7 +746,7 @@
     };
 
     EXPECT_CALL(mRenderEngine, drawLayers(_, _, _, _, _, _)).WillOnce(Invoke(drawLayers));
-    cachedSet.render(mRenderEngine, mOutputState);
+    cachedSet.render(mRenderEngine, mTexturePool, mOutputState);
 }
 
 } // namespace
diff --git a/services/surfaceflinger/CompositionEngine/tests/planner/FlattenerTest.cpp b/services/surfaceflinger/CompositionEngine/tests/planner/FlattenerTest.cpp
index 8b03964..e176c98 100644
--- a/services/surfaceflinger/CompositionEngine/tests/planner/FlattenerTest.cpp
+++ b/services/surfaceflinger/CompositionEngine/tests/planner/FlattenerTest.cpp
@@ -46,13 +46,14 @@
 
 class TestableFlattener : public Flattener {
 public:
-    TestableFlattener(bool enableHolePunch) : Flattener(enableHolePunch) {}
+    TestableFlattener(renderengine::RenderEngine& renderEngine, bool enableHolePunch)
+          : Flattener(renderEngine, enableHolePunch) {}
     const std::optional<CachedSet>& getNewCachedSetForTesting() const { return mNewCachedSet; }
 };
 
 class FlattenerTest : public testing::Test {
 public:
-    FlattenerTest() : mFlattener(std::make_unique<TestableFlattener>(true)) {}
+    FlattenerTest() : mFlattener(std::make_unique<TestableFlattener>(mRenderEngine, true)) {}
     void SetUp() override;
 
 protected:
@@ -60,7 +61,7 @@
     void initializeFlattener(const std::vector<const LayerState*>& layers);
     void expectAllLayersFlattened(const std::vector<const LayerState*>& layers);
 
-    // mRenderEngine may be held as a pointer to mFlattener, so mFlattener must be destroyed first.
+    // mRenderEngine is held as a reference in mFlattener, so mFlattener must be destroyed first.
     renderengine::mock::RenderEngine mRenderEngine;
     std::unique_ptr<TestableFlattener> mFlattener;
 
@@ -84,6 +85,7 @@
 };
 
 void FlattenerTest::SetUp() {
+    mFlattener->setDisplaySize({1, 1});
     for (size_t i = 0; i < kNumLayers; i++) {
         auto testLayer = std::make_unique<TestLayer>();
         auto pos = static_cast<int32_t>(i);
@@ -146,13 +148,13 @@
     initializeOverrideBuffer(layers);
     EXPECT_EQ(getNonBufferHash(layers),
               mFlattener->flattenLayers(layers, getNonBufferHash(layers), mTime));
-    mFlattener->renderCachedSets(mRenderEngine, mOutputState);
+    mFlattener->renderCachedSets(mOutputState);
 
     // same geometry, update the internal layer stack
     initializeOverrideBuffer(layers);
     EXPECT_EQ(getNonBufferHash(layers),
               mFlattener->flattenLayers(layers, getNonBufferHash(layers), mTime));
-    mFlattener->renderCachedSets(mRenderEngine, mOutputState);
+    mFlattener->renderCachedSets(mOutputState);
 }
 
 void FlattenerTest::expectAllLayersFlattened(const std::vector<const LayerState*>& layers) {
@@ -162,7 +164,7 @@
     initializeOverrideBuffer(layers);
     EXPECT_EQ(getNonBufferHash(layers),
               mFlattener->flattenLayers(layers, getNonBufferHash(layers), mTime));
-    mFlattener->renderCachedSets(mRenderEngine, mOutputState);
+    mFlattener->renderCachedSets(mOutputState);
 
     for (const auto layer : layers) {
         EXPECT_EQ(nullptr, layer->getOutputLayer()->getState().overrideInfo.buffer);
@@ -172,7 +174,7 @@
     initializeOverrideBuffer(layers);
     EXPECT_NE(getNonBufferHash(layers),
               mFlattener->flattenLayers(layers, getNonBufferHash(layers), mTime));
-    mFlattener->renderCachedSets(mRenderEngine, mOutputState);
+    mFlattener->renderCachedSets(mOutputState);
 
     const auto buffer = layers[0]->getOutputLayer()->getState().overrideInfo.buffer;
     EXPECT_NE(nullptr, buffer);
@@ -207,7 +209,7 @@
     initializeOverrideBuffer(layers);
     EXPECT_EQ(getNonBufferHash(layers),
               mFlattener->flattenLayers(layers, getNonBufferHash(layers), mTime));
-    mFlattener->renderCachedSets(mRenderEngine, mOutputState);
+    mFlattener->renderCachedSets(mOutputState);
 }
 
 TEST_F(FlattenerTest, flattenLayers_basicFlatten) {
@@ -253,7 +255,7 @@
     initializeOverrideBuffer(layers);
     EXPECT_NE(getNonBufferHash(layers),
               mFlattener->flattenLayers(layers, getNonBufferHash(layers), mTime));
-    mFlattener->renderCachedSets(mRenderEngine, mOutputState);
+    mFlattener->renderCachedSets(mOutputState);
 
     EXPECT_NE(nullptr, overrideBuffer1);
     EXPECT_EQ(overrideBuffer1, overrideBuffer2);
@@ -358,7 +360,7 @@
     initializeOverrideBuffer(layers);
     EXPECT_EQ(getNonBufferHash(layers),
               mFlattener->flattenLayers(layers, getNonBufferHash(layers), mTime));
-    mFlattener->renderCachedSets(mRenderEngine, mOutputState);
+    mFlattener->renderCachedSets(mOutputState);
 
     EXPECT_EQ(nullptr, overrideBuffer1);
     EXPECT_EQ(nullptr, overrideBuffer2);
@@ -395,7 +397,7 @@
     initializeOverrideBuffer(layers);
     EXPECT_EQ(getNonBufferHash(layers),
               mFlattener->flattenLayers(layers, getNonBufferHash(layers), mTime));
-    mFlattener->renderCachedSets(mRenderEngine, mOutputState);
+    mFlattener->renderCachedSets(mOutputState);
 
     EXPECT_EQ(nullptr, overrideBuffer1);
     EXPECT_EQ(nullptr, overrideBuffer2);
@@ -404,7 +406,7 @@
     initializeOverrideBuffer(layers);
     EXPECT_NE(getNonBufferHash(layers),
               mFlattener->flattenLayers(layers, getNonBufferHash(layers), mTime));
-    mFlattener->renderCachedSets(mRenderEngine, mOutputState);
+    mFlattener->renderCachedSets(mOutputState);
 
     EXPECT_EQ(nullptr, overrideBuffer1);
     EXPECT_NE(nullptr, overrideBuffer2);
@@ -417,7 +419,7 @@
     initializeOverrideBuffer(layers);
     EXPECT_NE(getNonBufferHash(layers),
               mFlattener->flattenLayers(layers, getNonBufferHash(layers), mTime));
-    mFlattener->renderCachedSets(mRenderEngine, mOutputState);
+    mFlattener->renderCachedSets(mOutputState);
 
     EXPECT_EQ(nullptr, overrideBuffer1);
     EXPECT_NE(nullptr, overrideBuffer2);
@@ -426,7 +428,7 @@
     initializeOverrideBuffer(layers);
     EXPECT_NE(getNonBufferHash(layers),
               mFlattener->flattenLayers(layers, getNonBufferHash(layers), mTime));
-    mFlattener->renderCachedSets(mRenderEngine, mOutputState);
+    mFlattener->renderCachedSets(mOutputState);
 
     EXPECT_NE(nullptr, overrideBuffer1);
     EXPECT_EQ(overrideBuffer1, overrideBuffer2);
@@ -468,7 +470,7 @@
     initializeOverrideBuffer(layers);
     EXPECT_EQ(getNonBufferHash(layers),
               mFlattener->flattenLayers(layers, getNonBufferHash(layers), mTime));
-    mFlattener->renderCachedSets(mRenderEngine, mOutputState);
+    mFlattener->renderCachedSets(mOutputState);
 
     EXPECT_EQ(nullptr, overrideBuffer1);
     EXPECT_EQ(nullptr, overrideBuffer2);
@@ -482,7 +484,7 @@
     EXPECT_NE(getNonBufferHash(layers),
               mFlattener->flattenLayers(layers, getNonBufferHash(layers), mTime));
     mOutputState.framebufferSpace.orientation = ui::ROTATION_90;
-    mFlattener->renderCachedSets(mRenderEngine, mOutputState);
+    mFlattener->renderCachedSets(mOutputState);
 
     EXPECT_NE(nullptr, overrideBuffer1);
     EXPECT_EQ(overrideBuffer1, overrideBuffer2);
@@ -495,7 +497,7 @@
     EXPECT_NE(getNonBufferHash(layers),
               mFlattener->flattenLayers(layers, getNonBufferHash(layers), mTime));
     mOutputState.framebufferSpace.orientation = ui::ROTATION_180;
-    mFlattener->renderCachedSets(mRenderEngine, mOutputState);
+    mFlattener->renderCachedSets(mOutputState);
 
     EXPECT_NE(nullptr, overrideBuffer1);
     EXPECT_EQ(overrideBuffer1, overrideBuffer2);
@@ -510,7 +512,7 @@
     initializeOverrideBuffer(layers);
     EXPECT_NE(getNonBufferHash(layers),
               mFlattener->flattenLayers(layers, getNonBufferHash(layers), mTime));
-    mFlattener->renderCachedSets(mRenderEngine, mOutputState);
+    mFlattener->renderCachedSets(mOutputState);
 
     EXPECT_NE(nullptr, overrideBuffer1);
     EXPECT_EQ(overrideBuffer1, overrideBuffer2);
@@ -522,7 +524,7 @@
     EXPECT_NE(getNonBufferHash(layers),
               mFlattener->flattenLayers(layers, getNonBufferHash(layers), mTime));
     mOutputState.framebufferSpace.orientation = ui::ROTATION_270;
-    mFlattener->renderCachedSets(mRenderEngine, mOutputState);
+    mFlattener->renderCachedSets(mOutputState);
 
     EXPECT_NE(nullptr, overrideBuffer1);
     EXPECT_EQ(overrideBuffer1, overrideBuffer2);
@@ -561,7 +563,7 @@
 
     // This will render a CachedSet.
     EXPECT_CALL(mRenderEngine, drawLayers(_, _, _, _, _, _)).WillOnce(Return(NO_ERROR));
-    mFlattener->renderCachedSets(mRenderEngine, mOutputState);
+    mFlattener->renderCachedSets(mOutputState);
 
     // We've rendered a CachedSet, but we haven't merged it in.
     EXPECT_EQ(nullptr, overrideBuffer1);
@@ -574,7 +576,7 @@
     initializeOverrideBuffer(layers);
     EXPECT_NE(getNonBufferHash(layers),
               mFlattener->flattenLayers(layers, getNonBufferHash(layers), mTime));
-    mFlattener->renderCachedSets(mRenderEngine, mOutputState);
+    mFlattener->renderCachedSets(mOutputState);
 
     EXPECT_NE(nullptr, overrideBuffer1);
     EXPECT_EQ(overrideBuffer1, overrideBuffer2);
@@ -623,7 +625,7 @@
 
     // This will render a CachedSet.
     EXPECT_CALL(mRenderEngine, drawLayers(_, _, _, _, _, _)).WillOnce(Return(NO_ERROR));
-    mFlattener->renderCachedSets(mRenderEngine, mOutputState);
+    mFlattener->renderCachedSets(mOutputState);
 
     // We've rendered a CachedSet, but we haven't merged it in.
     EXPECT_EQ(nullptr, overrideBuffer1);
@@ -636,7 +638,7 @@
     initializeOverrideBuffer(layers);
     EXPECT_NE(getNonBufferHash(layers),
               mFlattener->flattenLayers(layers, getNonBufferHash(layers), mTime));
-    mFlattener->renderCachedSets(mRenderEngine, mOutputState);
+    mFlattener->renderCachedSets(mOutputState);
 
     EXPECT_NE(nullptr, overrideBuffer1);
     EXPECT_EQ(overrideBuffer1, overrideBuffer2);
@@ -680,7 +682,7 @@
     initializeOverrideBuffer(layers);
     EXPECT_EQ(getNonBufferHash(layers),
               mFlattener->flattenLayers(layers, getNonBufferHash(layers), mTime));
-    mFlattener->renderCachedSets(mRenderEngine, mOutputState);
+    mFlattener->renderCachedSets(mOutputState);
 
     for (const auto layer : layers) {
         EXPECT_EQ(nullptr, layer->getOutputLayer()->getState().overrideInfo.buffer);
@@ -690,7 +692,7 @@
     initializeOverrideBuffer(layers);
     EXPECT_NE(getNonBufferHash(layers),
               mFlattener->flattenLayers(layers, getNonBufferHash(layers), mTime));
-    mFlattener->renderCachedSets(mRenderEngine, mOutputState);
+    mFlattener->renderCachedSets(mOutputState);
     EXPECT_NE(nullptr, overrideBuffer1);
     EXPECT_EQ(overrideBuffer1, overrideBuffer2);
     EXPECT_EQ(nullptr, overrideBuffer3);
@@ -724,7 +726,7 @@
     initializeOverrideBuffer(layers);
     EXPECT_EQ(getNonBufferHash(layers),
               mFlattener->flattenLayers(layers, getNonBufferHash(layers), mTime));
-    mFlattener->renderCachedSets(mRenderEngine, mOutputState);
+    mFlattener->renderCachedSets(mOutputState);
 
     for (const auto layer : layers) {
         EXPECT_EQ(nullptr, layer->getOutputLayer()->getState().overrideInfo.buffer);
@@ -735,7 +737,7 @@
     initializeOverrideBuffer(layers);
     EXPECT_EQ(getNonBufferHash(layers),
               mFlattener->flattenLayers(layers, getNonBufferHash(layers), mTime));
-    mFlattener->renderCachedSets(mRenderEngine, mOutputState);
+    mFlattener->renderCachedSets(mOutputState);
     for (const auto layer : layers) {
         EXPECT_EQ(nullptr, layer->getOutputLayer()->getState().overrideInfo.buffer);
     }
@@ -776,7 +778,7 @@
     initializeOverrideBuffer(layers);
     EXPECT_EQ(getNonBufferHash(layers),
               mFlattener->flattenLayers(layers, getNonBufferHash(layers), mTime));
-    mFlattener->renderCachedSets(mRenderEngine, mOutputState);
+    mFlattener->renderCachedSets(mOutputState);
 
     for (const auto layer : layers) {
         EXPECT_EQ(nullptr, layer->getOutputLayer()->getState().overrideInfo.buffer);
@@ -786,7 +788,7 @@
     initializeOverrideBuffer(layers);
     EXPECT_NE(getNonBufferHash(layers),
               mFlattener->flattenLayers(layers, getNonBufferHash(layers), mTime));
-    mFlattener->renderCachedSets(mRenderEngine, mOutputState);
+    mFlattener->renderCachedSets(mOutputState);
     EXPECT_EQ(nullptr, overrideBuffer1);
     EXPECT_EQ(nullptr, blurOverrideBuffer);
     EXPECT_NE(nullptr, overrideBuffer3);
@@ -823,7 +825,7 @@
     initializeOverrideBuffer(layers);
     EXPECT_EQ(getNonBufferHash(layers),
               mFlattener->flattenLayers(layers, getNonBufferHash(layers), mTime));
-    mFlattener->renderCachedSets(mRenderEngine, mOutputState);
+    mFlattener->renderCachedSets(mOutputState);
 
     const auto& cachedSet = mFlattener->getNewCachedSetForTesting();
     ASSERT_NE(std::nullopt, cachedSet);
@@ -837,7 +839,7 @@
     initializeOverrideBuffer(layers);
     EXPECT_NE(getNonBufferHash(layers),
               mFlattener->flattenLayers(layers, getNonBufferHash(layers), mTime));
-    mFlattener->renderCachedSets(mRenderEngine, mOutputState);
+    mFlattener->renderCachedSets(mOutputState);
     EXPECT_NE(nullptr, overrideBuffer1);
     EXPECT_EQ(overrideBuffer2, overrideBuffer1);
     EXPECT_EQ(nullptr, blurOverrideBuffer);
@@ -864,7 +866,7 @@
     initializeOverrideBuffer(layers);
     EXPECT_EQ(getNonBufferHash(layers),
               mFlattener->flattenLayers(layers, getNonBufferHash(layers), mTime));
-    mFlattener->renderCachedSets(mRenderEngine, mOutputState);
+    mFlattener->renderCachedSets(mOutputState);
 
     EXPECT_EQ(nullptr, overrideBuffer1);
     EXPECT_EQ(nullptr, overrideBuffer2);
@@ -872,12 +874,12 @@
     // Simulate attempting to render prior to merging the new cached set with the layer stack.
     // Here we should not try to re-render.
     EXPECT_CALL(mRenderEngine, drawLayers(_, _, _, _, _, _)).Times(0);
-    mFlattener->renderCachedSets(mRenderEngine, mOutputState);
+    mFlattener->renderCachedSets(mOutputState);
 
     // We provide the override buffer now that it's rendered
     EXPECT_NE(getNonBufferHash(layers),
               mFlattener->flattenLayers(layers, getNonBufferHash(layers), mTime));
-    mFlattener->renderCachedSets(mRenderEngine, mOutputState);
+    mFlattener->renderCachedSets(mOutputState);
 
     EXPECT_NE(nullptr, overrideBuffer1);
     EXPECT_EQ(overrideBuffer2, overrideBuffer1);
diff --git a/services/surfaceflinger/CompositionEngine/tests/planner/TexturePoolTest.cpp b/services/surfaceflinger/CompositionEngine/tests/planner/TexturePoolTest.cpp
new file mode 100644
index 0000000..b802e51
--- /dev/null
+++ b/services/surfaceflinger/CompositionEngine/tests/planner/TexturePoolTest.cpp
@@ -0,0 +1,134 @@
+/*
+ * Copyright 2021 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.
+ */
+
+#undef LOG_TAG
+#define LOG_TAG "TexturePoolTest"
+
+#include <compositionengine/impl/planner/TexturePool.h>
+#include <gtest/gtest.h>
+#include <log/log.h>
+#include <renderengine/mock/RenderEngine.h>
+
+namespace android::compositionengine::impl::planner {
+namespace {
+
+const ui::Size kDisplaySize(1, 1);
+const ui::Size kDisplaySizeTwo(2, 2);
+
+class TestableTexturePool : public TexturePool {
+public:
+    TestableTexturePool(renderengine::RenderEngine& renderEngine) : TexturePool(renderEngine) {}
+
+    size_t getMinPoolSize() const { return kMinPoolSize; }
+    size_t getMaxPoolSize() const { return kMaxPoolSize; }
+    size_t getPoolSize() const { return mPool.size(); }
+};
+
+struct TexturePoolTest : public testing::Test {
+    TexturePoolTest() {
+        const ::testing::TestInfo* const test_info =
+                ::testing::UnitTest::GetInstance()->current_test_info();
+        ALOGD("**** Setting up for %s.%s\n", test_info->test_case_name(), test_info->name());
+        mTexturePool.setDisplaySize(kDisplaySize);
+    }
+
+    ~TexturePoolTest() {
+        const ::testing::TestInfo* const test_info =
+                ::testing::UnitTest::GetInstance()->current_test_info();
+        ALOGD("**** Tearing down after %s.%s\n", test_info->test_case_name(), test_info->name());
+    }
+
+    renderengine::mock::RenderEngine mRenderEngine;
+    TestableTexturePool mTexturePool = TestableTexturePool(mRenderEngine);
+};
+
+TEST_F(TexturePoolTest, preallocatesMinPool) {
+    EXPECT_EQ(mTexturePool.getMinPoolSize(), mTexturePool.getPoolSize());
+}
+
+TEST_F(TexturePoolTest, doesNotAllocateBeyondMinPool) {
+    for (size_t i = 0; i < mTexturePool.getMinPoolSize() + 1; i++) {
+        auto texture = mTexturePool.borrowTexture();
+    }
+
+    EXPECT_EQ(mTexturePool.getMinPoolSize(), mTexturePool.getPoolSize());
+}
+
+TEST_F(TexturePoolTest, cyclesUpToMaxPoolSize) {
+    std::unordered_set<uint64_t> bufferIds;
+    std::deque<std::shared_ptr<TexturePool::AutoTexture>> textures;
+    for (size_t i = 0; i < mTexturePool.getMaxPoolSize(); i++) {
+        textures.emplace_back(mTexturePool.borrowTexture());
+        bufferIds.insert(textures.back()->get()->getBuffer()->getId());
+    }
+
+    EXPECT_EQ(mTexturePool.getMaxPoolSize(), bufferIds.size());
+
+    for (size_t i = 0; i < 3; i++) {
+        textures.pop_front();
+        textures.emplace_back(mTexturePool.borrowTexture());
+        bufferIds.insert(textures.back()->get()->getBuffer()->getId());
+    }
+
+    EXPECT_EQ(mTexturePool.getMaxPoolSize(), bufferIds.size());
+}
+
+TEST_F(TexturePoolTest, goesPastMaxSizeAndRebounds) {
+    std::unordered_set<uint64_t> bufferIds;
+    std::vector<std::shared_ptr<TexturePool::AutoTexture>> textures;
+    for (size_t i = 0; i < mTexturePool.getMaxPoolSize() + 2; i++) {
+        textures.emplace_back(mTexturePool.borrowTexture());
+        bufferIds.insert(textures.back()->get()->getBuffer()->getId());
+    }
+
+    EXPECT_EQ(mTexturePool.getMaxPoolSize() + 2, bufferIds.size());
+
+    // Return the textures to the pool.
+    // Now when we cycle through the pool it's again bounded by max textures.
+    textures.clear();
+
+    std::unordered_set<uint64_t> newBufferIds;
+    for (size_t i = 0; i < 2 * mTexturePool.getMaxPoolSize(); i++) {
+        auto texture = mTexturePool.borrowTexture();
+        newBufferIds.insert(texture->get()->getBuffer()->getId());
+    }
+
+    EXPECT_EQ(mTexturePool.getMaxPoolSize(), newBufferIds.size());
+}
+
+TEST_F(TexturePoolTest, reallocatesWhenDisplaySizeChanges) {
+    auto texture = mTexturePool.borrowTexture();
+
+    EXPECT_EQ(kDisplaySize.getWidth(),
+              static_cast<int32_t>(texture->get()->getBuffer()->getWidth()));
+    EXPECT_EQ(kDisplaySize.getHeight(),
+              static_cast<int32_t>(texture->get()->getBuffer()->getHeight()));
+    mTexturePool.setDisplaySize(kDisplaySizeTwo);
+
+    EXPECT_EQ(mTexturePool.getMinPoolSize(), mTexturePool.getPoolSize());
+    texture.reset();
+    // When the texture is returned to the pool, the pool now destroys it.
+    EXPECT_EQ(mTexturePool.getMinPoolSize(), mTexturePool.getPoolSize());
+
+    texture = mTexturePool.borrowTexture();
+    EXPECT_EQ(kDisplaySizeTwo.getWidth(),
+              static_cast<int32_t>(texture->get()->getBuffer()->getWidth()));
+    EXPECT_EQ(kDisplaySizeTwo.getHeight(),
+              static_cast<int32_t>(texture->get()->getBuffer()->getHeight()));
+}
+
+} // namespace
+} // namespace android::compositionengine::impl::planner