diff --git a/services/surfaceflinger/CompositionEngine/Android.bp b/services/surfaceflinger/CompositionEngine/Android.bp
index f9e5b9a..88998b0 100644
--- a/services/surfaceflinger/CompositionEngine/Android.bp
+++ b/services/surfaceflinger/CompositionEngine/Android.bp
@@ -103,6 +103,7 @@
     test_suites: ["device-tests"],
     defaults: ["libcompositionengine_defaults"],
     srcs: [
+        "tests/planner/CachedSetTest.cpp",
         "tests/CompositionEngineTest.cpp",
         "tests/DisplayColorProfileTest.cpp",
         "tests/DisplayTest.cpp",
diff --git a/services/surfaceflinger/CompositionEngine/tests/planner/CachedSetTest.cpp b/services/surfaceflinger/CompositionEngine/tests/planner/CachedSetTest.cpp
new file mode 100644
index 0000000..6d1ce4c
--- /dev/null
+++ b/services/surfaceflinger/CompositionEngine/tests/planner/CachedSetTest.cpp
@@ -0,0 +1,318 @@
+/*
+ * 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.
+ */
+
+#include <compositionengine/impl/planner/CachedSet.h>
+#include <compositionengine/impl/planner/LayerState.h>
+#include <compositionengine/mock/LayerFE.h>
+#include <compositionengine/mock/OutputLayer.h>
+#include <gtest/gtest.h>
+#include <renderengine/mock/RenderEngine.h>
+
+namespace android::compositionengine {
+using namespace std::chrono_literals;
+
+using testing::_;
+using testing::DoAll;
+using testing::Invoke;
+using testing::Return;
+using testing::ReturnRef;
+using testing::SetArgPointee;
+
+using impl::planner::CachedSet;
+using impl::planner::LayerState;
+using impl::planner::LayerStateField;
+
+namespace {
+
+class CachedSetTest : public testing::Test {
+public:
+    CachedSetTest() = default;
+    void SetUp() override;
+    void TearDown() override;
+
+protected:
+    const std::chrono::steady_clock::time_point kStartTime = std::chrono::steady_clock::now();
+
+    struct TestLayer {
+        mock::OutputLayer outputLayer;
+        impl::OutputLayerCompositionState outputLayerCompositionState;
+        // LayerFE inherits from RefBase and must be held by an sp<>
+        sp<mock::LayerFE> layerFE;
+        LayerFECompositionState layerFECompositionState;
+
+        std::unique_ptr<LayerState> layerState;
+        std::unique_ptr<CachedSet::Layer> cachedSetLayer;
+    };
+
+    static constexpr size_t kNumLayers = 5;
+    std::vector<std::unique_ptr<TestLayer>> mTestLayers;
+
+    android::renderengine::mock::RenderEngine mRenderEngine;
+};
+
+void CachedSetTest::SetUp() {
+    for (size_t i = 0; i < kNumLayers; i++) {
+        auto testLayer = std::make_unique<TestLayer>();
+        auto pos = static_cast<int32_t>(i);
+        testLayer->outputLayerCompositionState.displayFrame = Rect(pos, pos, pos + 1, pos + 1);
+
+        testLayer->layerFE = sp<mock::LayerFE>::make();
+
+        EXPECT_CALL(*testLayer->layerFE, getSequence)
+                .WillRepeatedly(Return(static_cast<int32_t>(i)));
+        EXPECT_CALL(*testLayer->layerFE, getDebugName).WillRepeatedly(Return("testLayer"));
+        EXPECT_CALL(*testLayer->layerFE, getCompositionState)
+                .WillRepeatedly(Return(&testLayer->layerFECompositionState));
+        EXPECT_CALL(testLayer->outputLayer, getLayerFE)
+                .WillRepeatedly(ReturnRef(*testLayer->layerFE));
+        EXPECT_CALL(testLayer->outputLayer, getState)
+                .WillRepeatedly(ReturnRef(testLayer->outputLayerCompositionState));
+
+        testLayer->layerState = std::make_unique<LayerState>(&testLayer->outputLayer);
+        testLayer->layerState->incrementFramesSinceBufferUpdate();
+        testLayer->cachedSetLayer =
+                std::make_unique<CachedSet::Layer>(testLayer->layerState.get(), kStartTime);
+
+        mTestLayers.emplace_back(std::move(testLayer));
+    }
+}
+
+void CachedSetTest::TearDown() {
+    mTestLayers.clear();
+}
+
+void expectEqual(const CachedSet& cachedSet, const CachedSet::Layer& layer) {
+    EXPECT_EQ(layer.getHash(), cachedSet.getFingerprint());
+    EXPECT_EQ(layer.getLastUpdate(), cachedSet.getLastUpdate());
+    EXPECT_EQ(layer.getDisplayFrame(), cachedSet.getBounds());
+    EXPECT_EQ(1u, cachedSet.getLayerCount());
+    EXPECT_EQ(layer.getState(), cachedSet.getFirstLayer().getState());
+    EXPECT_EQ(0u, cachedSet.getAge());
+    EXPECT_EQ(layer.getHash(), cachedSet.getNonBufferHash());
+}
+
+void expectEqual(const CachedSet& cachedSet, const LayerState& layerState,
+                 std::chrono::steady_clock::time_point lastUpdate) {
+    CachedSet::Layer layer(&layerState, lastUpdate);
+    expectEqual(cachedSet, layer);
+}
+
+void expectNoBuffer(const CachedSet& cachedSet) {
+    EXPECT_EQ(nullptr, cachedSet.getBuffer());
+    EXPECT_EQ(nullptr, cachedSet.getDrawFence());
+    EXPECT_FALSE(cachedSet.hasReadyBuffer());
+}
+
+void expectReadyBuffer(const CachedSet& cachedSet) {
+    EXPECT_NE(nullptr, cachedSet.getBuffer());
+    EXPECT_NE(nullptr, cachedSet.getDrawFence());
+    EXPECT_TRUE(cachedSet.hasReadyBuffer());
+}
+
+TEST_F(CachedSetTest, createFromLayer) {
+    CachedSet::Layer& layer = *mTestLayers[0]->cachedSetLayer.get();
+    CachedSet cachedSet(layer);
+    expectEqual(cachedSet, layer);
+    expectNoBuffer(cachedSet);
+}
+
+TEST_F(CachedSetTest, createFromLayerState) {
+    LayerState& layerState = *mTestLayers[0]->layerState.get();
+    CachedSet cachedSet(&layerState, kStartTime);
+    expectEqual(cachedSet, layerState, kStartTime);
+    expectNoBuffer(cachedSet);
+}
+
+TEST_F(CachedSetTest, addLayer) {
+    CachedSet::Layer& layer1 = *mTestLayers[0]->cachedSetLayer.get();
+    CachedSet::Layer& layer2 = *mTestLayers[1]->cachedSetLayer.get();
+
+    CachedSet cachedSet(layer1);
+    cachedSet.addLayer(layer2.getState(), kStartTime + 10ms);
+
+    EXPECT_EQ(layer1.getHash(), cachedSet.getFingerprint());
+    EXPECT_EQ(kStartTime, cachedSet.getLastUpdate());
+    EXPECT_EQ(Rect(0, 0, 2, 2), cachedSet.getBounds());
+    EXPECT_EQ(2u, cachedSet.getLayerCount());
+    EXPECT_EQ(0u, cachedSet.getAge());
+    expectNoBuffer(cachedSet);
+    // TODO(b/181192080): check that getNonBufferHash returns the correct hash value
+    // EXPECT_EQ(android::hashCombine(layer1.getHash(), layer2.getHash()),
+    // cachedSet.getNonBufferHash());
+}
+
+TEST_F(CachedSetTest, decompose) {
+    CachedSet::Layer& layer1 = *mTestLayers[0]->cachedSetLayer.get();
+    CachedSet::Layer& layer2 = *mTestLayers[1]->cachedSetLayer.get();
+    CachedSet::Layer& layer3 = *mTestLayers[2]->cachedSetLayer.get();
+
+    CachedSet cachedSet(layer1);
+    cachedSet.addLayer(layer2.getState(), kStartTime + 10ms);
+    cachedSet.addLayer(layer3.getState(), kStartTime + 20ms);
+
+    std::vector<CachedSet> decomposed = cachedSet.decompose();
+    EXPECT_EQ(3u, decomposed.size());
+    expectEqual(decomposed[0], *layer1.getState(), kStartTime);
+    expectNoBuffer(decomposed[0]);
+
+    expectEqual(decomposed[1], *layer2.getState(), kStartTime + 10ms);
+    expectNoBuffer(decomposed[1]);
+
+    expectEqual(decomposed[2], *layer3.getState(), kStartTime + 20ms);
+    expectNoBuffer(decomposed[2]);
+}
+
+TEST_F(CachedSetTest, setLastUpdate) {
+    LayerState& layerState = *mTestLayers[0]->layerState.get();
+    CachedSet cachedSet(&layerState, kStartTime);
+    cachedSet.setLastUpdate(kStartTime + 10ms);
+    expectEqual(cachedSet, layerState, kStartTime + 10ms);
+}
+
+TEST_F(CachedSetTest, incrementAge) {
+    CachedSet::Layer& layer = *mTestLayers[0]->cachedSetLayer.get();
+    CachedSet cachedSet(layer);
+    EXPECT_EQ(0u, cachedSet.getAge());
+    cachedSet.incrementAge();
+    EXPECT_EQ(1u, cachedSet.getAge());
+    cachedSet.incrementAge();
+    EXPECT_EQ(2u, cachedSet.getAge());
+}
+
+TEST_F(CachedSetTest, hasBufferUpdate_NoUpdate) {
+    CachedSet::Layer& layer1 = *mTestLayers[0]->cachedSetLayer.get();
+    CachedSet::Layer& layer2 = *mTestLayers[1]->cachedSetLayer.get();
+    CachedSet::Layer& layer3 = *mTestLayers[2]->cachedSetLayer.get();
+
+    CachedSet cachedSet(layer1);
+    cachedSet.addLayer(layer2.getState(), kStartTime + 10ms);
+    cachedSet.addLayer(layer3.getState(), kStartTime + 20ms);
+
+    std::vector<const LayerState*> incomingLayers = {
+            layer1.getState(),
+            layer2.getState(),
+            layer3.getState(),
+    };
+
+    EXPECT_FALSE(cachedSet.hasBufferUpdate(incomingLayers.begin()));
+}
+
+TEST_F(CachedSetTest, hasBufferUpdate_BufferUpdate) {
+    CachedSet::Layer& layer1 = *mTestLayers[0]->cachedSetLayer.get();
+    CachedSet::Layer& layer2 = *mTestLayers[1]->cachedSetLayer.get();
+    CachedSet::Layer& layer3 = *mTestLayers[2]->cachedSetLayer.get();
+
+    CachedSet cachedSet(layer1);
+    cachedSet.addLayer(layer2.getState(), kStartTime + 10ms);
+    cachedSet.addLayer(layer3.getState(), kStartTime + 20ms);
+
+    mTestLayers[1]->layerState->resetFramesSinceBufferUpdate();
+
+    std::vector<const LayerState*> incomingLayers = {
+            layer1.getState(),
+            layer2.getState(),
+            layer3.getState(),
+    };
+
+    EXPECT_TRUE(cachedSet.hasBufferUpdate(incomingLayers.begin()));
+}
+
+TEST_F(CachedSetTest, append) {
+    CachedSet::Layer& layer1 = *mTestLayers[0]->cachedSetLayer.get();
+    CachedSet::Layer& layer2 = *mTestLayers[1]->cachedSetLayer.get();
+    CachedSet::Layer& layer3 = *mTestLayers[2]->cachedSetLayer.get();
+
+    CachedSet cachedSet1(layer1);
+    CachedSet cachedSet2(layer2);
+    cachedSet1.addLayer(layer3.getState(), kStartTime + 10ms);
+    cachedSet1.append(cachedSet2);
+
+    EXPECT_EQ(layer1.getHash(), cachedSet1.getFingerprint());
+    EXPECT_EQ(kStartTime, cachedSet1.getLastUpdate());
+    EXPECT_EQ(Rect(0, 0, 3, 3), cachedSet1.getBounds());
+    EXPECT_EQ(3u, cachedSet1.getLayerCount());
+    EXPECT_EQ(0u, cachedSet1.getAge());
+    expectNoBuffer(cachedSet1);
+    // TODO(b/181192080): check that getNonBufferHash returns the correct hash value
+    // EXPECT_EQ(android::hashCombine(layer1.getHash(), layer2.getHash()),
+    // cachedSet1.getNonBufferHash());
+}
+
+TEST_F(CachedSetTest, updateAge_NoUpdate) {
+    CachedSet::Layer& layer = *mTestLayers[0]->cachedSetLayer.get();
+
+    CachedSet cachedSet(layer);
+    cachedSet.incrementAge();
+    EXPECT_EQ(kStartTime, cachedSet.getLastUpdate());
+    EXPECT_EQ(1u, cachedSet.getAge());
+
+    cachedSet.updateAge(kStartTime + 10ms);
+    EXPECT_EQ(kStartTime, cachedSet.getLastUpdate());
+    EXPECT_EQ(1u, cachedSet.getAge());
+}
+
+TEST_F(CachedSetTest, updateAge_BufferUpdate) {
+    CachedSet::Layer& layer = *mTestLayers[0]->cachedSetLayer.get();
+    mTestLayers[0]->layerState->resetFramesSinceBufferUpdate();
+
+    CachedSet cachedSet(layer);
+    cachedSet.incrementAge();
+    EXPECT_EQ(kStartTime, cachedSet.getLastUpdate());
+    EXPECT_EQ(1u, cachedSet.getAge());
+
+    cachedSet.updateAge(kStartTime + 10ms);
+    EXPECT_EQ(kStartTime + 10ms, cachedSet.getLastUpdate());
+    EXPECT_EQ(0u, cachedSet.getAge());
+}
+
+TEST_F(CachedSetTest, render) {
+    CachedSet::Layer& layer1 = *mTestLayers[0]->cachedSetLayer.get();
+    sp<mock::LayerFE> layerFE1 = mTestLayers[0]->layerFE;
+    CachedSet::Layer& layer2 = *mTestLayers[1]->cachedSetLayer.get();
+    sp<mock::LayerFE> layerFE2 = mTestLayers[1]->layerFE;
+
+    CachedSet cachedSet(layer1);
+    cachedSet.append(CachedSet(layer2));
+
+    std::vector<compositionengine::LayerFE::LayerSettings> clientCompList1;
+    clientCompList1.push_back({});
+    clientCompList1[0].alpha = 0.5f;
+
+    std::vector<compositionengine::LayerFE::LayerSettings> clientCompList2;
+    clientCompList2.push_back({});
+    clientCompList2[0].alpha = 0.75f;
+
+    const auto drawLayers = [&](const renderengine::DisplaySettings& displaySettings,
+                                const std::vector<const renderengine::LayerSettings*>& layers,
+                                const sp<GraphicBuffer>&, const bool, base::unique_fd&&,
+                                base::unique_fd*) -> size_t {
+        EXPECT_EQ(Rect(0, 0, 2, 2), displaySettings.physicalDisplay);
+        EXPECT_EQ(Rect(0, 0, 2, 2), displaySettings.clip);
+        EXPECT_EQ(0.5f, layers[0]->alpha);
+        EXPECT_EQ(0.75f, layers[1]->alpha);
+
+        return NO_ERROR;
+    };
+
+    EXPECT_CALL(*layerFE1, prepareClientCompositionList(_)).WillOnce(Return(clientCompList1));
+    EXPECT_CALL(*layerFE2, prepareClientCompositionList(_)).WillOnce(Return(clientCompList2));
+    EXPECT_CALL(mRenderEngine, drawLayers(_, _, _, _, _, _)).WillOnce(Invoke(drawLayers));
+    cachedSet.render(mRenderEngine);
+    expectReadyBuffer(cachedSet);
+}
+
+} // namespace
+} // namespace android::compositionengine