Remove release fence flags

ce_fence_promise and screenshot_fence_preservation flags
have been out for several releases. They can be deleted,
along with any obsolete code related to the flag removal.

Bug: 351894825
Test: atest SurfaceFlinger_test
Flag: EXEMPT flag removal
Change-Id: Iba6166358c96ff6cfe5c64b68640fcd992c4089f

14 files changed, 57 insertions, 362 deletions

diff --git a/services/surfaceflinger/CompositionEngine/src/CompositionEngine.cpp b/services/surfaceflinger/CompositionEngine/src/CompositionEngine.cpp
index 5c5d0cd74d..cfcce473a2 100644
--- a/services/surfaceflinger/CompositionEngine/src/CompositionEngine.cpp
+++ b/services/surfaceflinger/CompositionEngine/src/CompositionEngine.cpp
@@ -198,25 +198,23 @@ void CompositionEngine::preComposition(CompositionRefreshArgs& args) {
 // these buffers and fire a NO_FENCE to release it. This ensures that all
 // promises for buffer releases are fulfilled at the end of composition.
 void CompositionEngine::postComposition(CompositionRefreshArgs& args) {
-    if (FlagManager::getInstance().ce_fence_promise()) {
-        SFTRACE_CALL();
-        ALOGV(__FUNCTION__);
-
-        for (auto& layerFE : args.layers) {
-            if (layerFE->getReleaseFencePromiseStatus() ==
-                LayerFE::ReleaseFencePromiseStatus::INITIALIZED) {
-                layerFE->setReleaseFence(Fence::NO_FENCE);
-            }
+    SFTRACE_CALL();
+    ALOGV(__FUNCTION__);
+
+    for (auto& layerFE : args.layers) {
+        if (layerFE->getReleaseFencePromiseStatus() ==
+            LayerFE::ReleaseFencePromiseStatus::INITIALIZED) {
+            layerFE->setReleaseFence(Fence::NO_FENCE);
         }
+    }
 
-        // List of layersWithQueuedFrames does not necessarily overlap with
-        // list of layers, so those layersWithQueuedFrames also need any
-        // unfulfilled promises to be resolved for completeness.
-        for (auto& layerFE : args.layersWithQueuedFrames) {
-            if (layerFE->getReleaseFencePromiseStatus() ==
-                LayerFE::ReleaseFencePromiseStatus::INITIALIZED) {
-                layerFE->setReleaseFence(Fence::NO_FENCE);
-            }
+    // List of layersWithQueuedFrames does not necessarily overlap with
+    // list of layers, so those layersWithQueuedFrames also need any
+    // unfulfilled promises to be resolved for completeness.
+    for (auto& layerFE : args.layersWithQueuedFrames) {
+        if (layerFE->getReleaseFencePromiseStatus() ==
+            LayerFE::ReleaseFencePromiseStatus::INITIALIZED) {
+            layerFE->setReleaseFence(Fence::NO_FENCE);
         }
     }
 }
diff --git a/services/surfaceflinger/CompositionEngine/src/Output.cpp b/services/surfaceflinger/CompositionEngine/src/Output.cpp
index 2d8f98f2a4..22ab3d953b 100644
--- a/services/surfaceflinger/CompositionEngine/src/Output.cpp
+++ b/services/surfaceflinger/CompositionEngine/src/Output.cpp
@@ -1610,13 +1610,7 @@ void Output::presentFrameAndReleaseLayers(bool flushEvenWhenDisabled) {
             releaseFence =
                     Fence::merge("LayerRelease", releaseFence, frame.clientTargetAcquireFence);
         }
-        if (FlagManager::getInstance().ce_fence_promise()) {
-            layer->getLayerFE().setReleaseFence(releaseFence);
-        } else {
-            layer->getLayerFE()
-                    .onLayerDisplayed(ftl::yield<FenceResult>(std::move(releaseFence)).share(),
-                                      outputState.layerFilter.layerStack);
-        }
+        layer->getLayerFE().setReleaseFence(releaseFence);
     }
 
     // We've got a list of layers needing fences, that are disjoint with
@@ -1624,12 +1618,7 @@ void Output::presentFrameAndReleaseLayers(bool flushEvenWhenDisabled) {
     // supply them with the present fence.
     for (auto& weakLayer : mReleasedLayers) {
         if (const auto layer = weakLayer.promote()) {
-            if (FlagManager::getInstance().ce_fence_promise()) {
-                layer->setReleaseFence(frame.presentFence);
-            } else {
-                layer->onLayerDisplayed(ftl::yield<FenceResult>(frame.presentFence).share(),
-                                        outputState.layerFilter.layerStack);
-            }
+            layer->setReleaseFence(frame.presentFence);
         }
     }
 
diff --git a/services/surfaceflinger/CompositionEngine/tests/CompositionEngineTest.cpp b/services/surfaceflinger/CompositionEngine/tests/CompositionEngineTest.cpp
index 639164d8c9..48ebc32eb8 100644
--- a/services/surfaceflinger/CompositionEngine/tests/CompositionEngineTest.cpp
+++ b/services/surfaceflinger/CompositionEngine/tests/CompositionEngineTest.cpp
@@ -30,8 +30,6 @@
 #include "TimeStats/TimeStats.h"
 #include "gmock/gmock.h"
 
-#include <variant>
-
 using namespace com::android::graphics::surfaceflinger;
 
 namespace android::compositionengine {
@@ -494,9 +492,6 @@ struct CompositionEnginePostCompositionTest : public CompositionEngineTest {
 };
 
 TEST_F(CompositionEnginePostCompositionTest, postCompositionReleasesAllFences) {
-    SET_FLAG_FOR_TEST(com::android::graphics::surfaceflinger::flags::ce_fence_promise, true);
-    ASSERT_TRUE(FlagManager::getInstance().ce_fence_promise());
-
     EXPECT_CALL(*mLayer1FE, getReleaseFencePromiseStatus)
             .WillOnce(Return(LayerFE::ReleaseFencePromiseStatus::FULFILLED));
     EXPECT_CALL(*mLayer2FE, getReleaseFencePromiseStatus)
diff --git a/services/surfaceflinger/CompositionEngine/tests/OutputTest.cpp b/services/surfaceflinger/CompositionEngine/tests/OutputTest.cpp
index c34168d025..1c18cd28c5 100644
--- a/services/surfaceflinger/CompositionEngine/tests/OutputTest.cpp
+++ b/services/surfaceflinger/CompositionEngine/tests/OutputTest.cpp
@@ -34,7 +34,6 @@
 #include <ui/Rect.h>
 #include <ui/Region.h>
 
-#include <cmath>
 #include <cstdint>
 #include <variant>
 
@@ -3263,57 +3262,9 @@ TEST_F(OutputPostFramebufferTest, ifEnabledMustFlipThenPresentThenSendPresentCom
     mOutput.presentFrameAndReleaseLayers(kFlushEvenWhenDisabled);
 }
 
-TEST_F(OutputPostFramebufferTest, releaseFencesAreSentToLayerFE) {
-    SET_FLAG_FOR_TEST(com::android::graphics::surfaceflinger::flags::ce_fence_promise, false);
-    ASSERT_FALSE(FlagManager::getInstance().ce_fence_promise());
-    // Simulate getting release fences from each layer, and ensure they are passed to the
-    // front-end layer interface for each layer correctly.
-
-    mOutput.mState.isEnabled = true;
-
-    // Create three unique fence instances
-    sp<Fence> layer1Fence = sp<Fence>::make();
-    sp<Fence> layer2Fence = sp<Fence>::make();
-    sp<Fence> layer3Fence = sp<Fence>::make();
-
-    Output::FrameFences frameFences;
-    frameFences.layerFences.emplace(&mLayer1.hwc2Layer, layer1Fence);
-    frameFences.layerFences.emplace(&mLayer2.hwc2Layer, layer2Fence);
-    frameFences.layerFences.emplace(&mLayer3.hwc2Layer, layer3Fence);
-
-    EXPECT_CALL(mOutput, presentFrame()).WillOnce(Return(frameFences));
-    EXPECT_CALL(*mRenderSurface, onPresentDisplayCompleted());
-
-    // Compare the pointers values of each fence to make sure the correct ones
-    // are passed. This happens to work with the current implementation, but
-    // would not survive certain calls like Fence::merge() which would return a
-    // new instance.
-    EXPECT_CALL(*mLayer1.layerFE, onLayerDisplayed(_, _))
-            .WillOnce([&layer1Fence](ftl::SharedFuture<FenceResult> futureFenceResult,
-                                     ui::LayerStack) {
-                EXPECT_EQ(FenceResult(layer1Fence), futureFenceResult.get());
-            });
-    EXPECT_CALL(*mLayer2.layerFE, onLayerDisplayed(_, _))
-            .WillOnce([&layer2Fence](ftl::SharedFuture<FenceResult> futureFenceResult,
-                                     ui::LayerStack) {
-                EXPECT_EQ(FenceResult(layer2Fence), futureFenceResult.get());
-            });
-    EXPECT_CALL(*mLayer3.layerFE, onLayerDisplayed(_, _))
-            .WillOnce([&layer3Fence](ftl::SharedFuture<FenceResult> futureFenceResult,
-                                     ui::LayerStack) {
-                EXPECT_EQ(FenceResult(layer3Fence), futureFenceResult.get());
-            });
-
-    constexpr bool kFlushEvenWhenDisabled = false;
-    mOutput.presentFrameAndReleaseLayers(kFlushEvenWhenDisabled);
-}
-
 TEST_F(OutputPostFramebufferTest, releaseFencesAreSetInLayerFE) {
-    SET_FLAG_FOR_TEST(com::android::graphics::surfaceflinger::flags::ce_fence_promise, true);
-    ASSERT_TRUE(FlagManager::getInstance().ce_fence_promise());
     // Simulate getting release fences from each layer, and ensure they are passed to the
     // front-end layer interface for each layer correctly.
-
     mOutput.mState.isEnabled = true;
 
     // Create three unique fence instances
@@ -3350,37 +3301,7 @@ TEST_F(OutputPostFramebufferTest, releaseFencesAreSetInLayerFE) {
     mOutput.presentFrameAndReleaseLayers(kFlushEvenWhenDisabled);
 }
 
-TEST_F(OutputPostFramebufferTest, releaseFencesIncludeClientTargetAcquireFence) {
-    SET_FLAG_FOR_TEST(com::android::graphics::surfaceflinger::flags::ce_fence_promise, false);
-    ASSERT_FALSE(FlagManager::getInstance().ce_fence_promise());
-
-    mOutput.mState.isEnabled = true;
-    mOutput.mState.usesClientComposition = true;
-
-    Output::FrameFences frameFences;
-    frameFences.clientTargetAcquireFence = sp<Fence>::make();
-    frameFences.layerFences.emplace(&mLayer1.hwc2Layer, sp<Fence>::make());
-    frameFences.layerFences.emplace(&mLayer2.hwc2Layer, sp<Fence>::make());
-    frameFences.layerFences.emplace(&mLayer3.hwc2Layer, sp<Fence>::make());
-
-    EXPECT_CALL(mOutput, presentFrame()).WillOnce(Return(frameFences));
-    EXPECT_CALL(*mRenderSurface, onPresentDisplayCompleted());
-
-    // Fence::merge is called, and since none of the fences are actually valid,
-    // Fence::NO_FENCE is returned and passed to each onLayerDisplayed() call.
-    // This is the best we can do without creating a real kernel fence object.
-    EXPECT_CALL(*mLayer1.layerFE, onLayerDisplayed).WillOnce(Return());
-    EXPECT_CALL(*mLayer2.layerFE, onLayerDisplayed).WillOnce(Return());
-    EXPECT_CALL(*mLayer3.layerFE, onLayerDisplayed).WillOnce(Return());
-
-    constexpr bool kFlushEvenWhenDisabled = false;
-    mOutput.presentFrameAndReleaseLayers(kFlushEvenWhenDisabled);
-}
-
 TEST_F(OutputPostFramebufferTest, setReleaseFencesIncludeClientTargetAcquireFence) {
-    SET_FLAG_FOR_TEST(com::android::graphics::surfaceflinger::flags::ce_fence_promise, true);
-    ASSERT_TRUE(FlagManager::getInstance().ce_fence_promise());
-
     mOutput.mState.isEnabled = true;
     mOutput.mState.usesClientComposition = true;
 
@@ -3403,62 +3324,7 @@ TEST_F(OutputPostFramebufferTest, setReleaseFencesIncludeClientTargetAcquireFenc
     mOutput.presentFrameAndReleaseLayers(kFlushEvenWhenDisabled);
 }
 
-TEST_F(OutputPostFramebufferTest, releasedLayersSentPresentFence) {
-    SET_FLAG_FOR_TEST(com::android::graphics::surfaceflinger::flags::ce_fence_promise, false);
-    ASSERT_FALSE(FlagManager::getInstance().ce_fence_promise());
-
-    mOutput.mState.isEnabled = true;
-    mOutput.mState.usesClientComposition = true;
-
-    // This should happen even if there are no (current) output layers.
-    EXPECT_CALL(mOutput, getOutputLayerCount()).WillOnce(Return(0u));
-
-    // Load up the released layers with some mock instances
-    sp<StrictMock<mock::LayerFE>> releasedLayer1 = sp<StrictMock<mock::LayerFE>>::make();
-    sp<StrictMock<mock::LayerFE>> releasedLayer2 = sp<StrictMock<mock::LayerFE>>::make();
-    sp<StrictMock<mock::LayerFE>> releasedLayer3 = sp<StrictMock<mock::LayerFE>>::make();
-    Output::ReleasedLayers layers;
-    layers.push_back(releasedLayer1);
-    layers.push_back(releasedLayer2);
-    layers.push_back(releasedLayer3);
-    mOutput.setReleasedLayers(std::move(layers));
-
-    // Set up a fake present fence
-    sp<Fence> presentFence = sp<Fence>::make();
-    Output::FrameFences frameFences;
-    frameFences.presentFence = presentFence;
-
-    EXPECT_CALL(mOutput, presentFrame()).WillOnce(Return(frameFences));
-    EXPECT_CALL(*mRenderSurface, onPresentDisplayCompleted());
-
-    // Each released layer should be given the presentFence.
-    EXPECT_CALL(*releasedLayer1, onLayerDisplayed(_, _))
-            .WillOnce([&presentFence](ftl::SharedFuture<FenceResult> futureFenceResult,
-                                      ui::LayerStack) {
-                EXPECT_EQ(FenceResult(presentFence), futureFenceResult.get());
-            });
-    EXPECT_CALL(*releasedLayer2, onLayerDisplayed(_, _))
-            .WillOnce([&presentFence](ftl::SharedFuture<FenceResult> futureFenceResult,
-                                      ui::LayerStack) {
-                EXPECT_EQ(FenceResult(presentFence), futureFenceResult.get());
-            });
-    EXPECT_CALL(*releasedLayer3, onLayerDisplayed(_, _))
-            .WillOnce([&presentFence](ftl::SharedFuture<FenceResult> futureFenceResult,
-                                      ui::LayerStack) {
-                EXPECT_EQ(FenceResult(presentFence), futureFenceResult.get());
-            });
-
-    constexpr bool kFlushEvenWhenDisabled = false;
-    mOutput.presentFrameAndReleaseLayers(kFlushEvenWhenDisabled);
-
-    // After the call the list of released layers should have been cleared.
-    EXPECT_TRUE(mOutput.getReleasedLayersForTest().empty());
-}
-
 TEST_F(OutputPostFramebufferTest, setReleasedLayersSentPresentFence) {
-    SET_FLAG_FOR_TEST(com::android::graphics::surfaceflinger::flags::ce_fence_promise, true);
-    ASSERT_TRUE(FlagManager::getInstance().ce_fence_promise());
-
     mOutput.mState.isEnabled = true;
     mOutput.mState.usesClientComposition = true;
 
diff --git a/services/surfaceflinger/Layer.cpp b/services/surfaceflinger/Layer.cpp
index c14769e61e..e5dc2eeda9 100644
--- a/services/surfaceflinger/Layer.cpp
+++ b/services/surfaceflinger/Layer.cpp
@@ -751,54 +751,6 @@ void Layer::prepareReleaseCallbacks(ftl::Future<FenceResult> futureFenceResult,
     }
 }
 
-void Layer::onLayerDisplayed(ftl::SharedFuture<FenceResult> futureFenceResult,
-                             ui::LayerStack layerStack,
-                             std::function<FenceResult(FenceResult)>&& continuation) {
-    sp<CallbackHandle> ch = findCallbackHandle();
-
-    if (!FlagManager::getInstance().screenshot_fence_preservation() && continuation) {
-        futureFenceResult = ftl::Future(futureFenceResult).then(std::move(continuation)).share();
-    }
-
-    if (ch != nullptr) {
-        ch->previousReleaseCallbackId = mPreviousReleaseCallbackId;
-        ch->previousSharedReleaseFences.emplace_back(std::move(futureFenceResult));
-        ch->name = mName;
-    } else if (FlagManager::getInstance().screenshot_fence_preservation()) {
-        // If we didn't get a release callback yet, e.g. some scenarios when capturing screenshots
-        // asynchronously, then make sure we don't drop the fence.
-        mPreviousReleaseFenceAndContinuations.emplace_back(std::move(futureFenceResult),
-                                                           std::move(continuation));
-        std::vector<FenceAndContinuation> mergedFences;
-        sp<Fence> prevFence = nullptr;
-        // For a layer that's frequently screenshotted, try to merge fences to make sure we don't
-        // grow unbounded.
-        for (const auto& futureAndContinuation : mPreviousReleaseFenceAndContinuations) {
-            auto result = futureAndContinuation.future.wait_for(0s);
-            if (result != std::future_status::ready) {
-                mergedFences.emplace_back(futureAndContinuation);
-                continue;
-            }
-
-            mergeFence(getDebugName(),
-                       futureAndContinuation.chain().get().value_or(Fence::NO_FENCE), prevFence);
-        }
-        if (prevFence != nullptr) {
-            mergedFences.emplace_back(ftl::yield(FenceResult(std::move(prevFence))).share());
-        }
-
-        mPreviousReleaseFenceAndContinuations.swap(mergedFences);
-    }
-
-    if (mBufferInfo.mBuffer) {
-        mPreviouslyPresentedLayerStacks.push_back(layerStack);
-    }
-
-    if (mDrawingState.frameNumber > 0) {
-        mDrawingState.previousFrameNumber = mDrawingState.frameNumber;
-    }
-}
-
 void Layer::releasePendingBuffer(nsecs_t dequeueReadyTime) {
     for (const auto& handle : mDrawingState.callbackHandles) {
         handle->bufferReleaseChannel = mBufferReleaseChannel;
@@ -1111,22 +1063,13 @@ bool Layer::setTransactionCompletedListeners(const std::vector<sp<CallbackHandle
             handle->acquireTimeOrFence = mCallbackHandleAcquireTimeOrFence;
             handle->frameNumber = mDrawingState.frameNumber;
             handle->previousFrameNumber = mDrawingState.previousFrameNumber;
-            if (FlagManager::getInstance().ce_fence_promise() &&
-                mPreviousReleaseBufferEndpoint == handle->listener) {
+            if (mPreviousReleaseBufferEndpoint == handle->listener) {
                 // Add fence from previous screenshot now so that it can be dispatched to the
                 // client.
                 for (auto& [_, future] : mAdditionalPreviousReleaseFences) {
                     handle->previousReleaseFences.emplace_back(std::move(future));
                 }
                 mAdditionalPreviousReleaseFences.clear();
-            } else if (FlagManager::getInstance().screenshot_fence_preservation() &&
-                       mPreviousReleaseBufferEndpoint == handle->listener) {
-                // Add fences from previous screenshots now so that they can be dispatched to the
-                // client.
-                for (const auto& futureAndContinution : mPreviousReleaseFenceAndContinuations) {
-                    handle->previousSharedReleaseFences.emplace_back(futureAndContinution.chain());
-                }
-                mPreviousReleaseFenceAndContinuations.clear();
             }
             // Store so latched time and release fence can be set
             mDrawingState.callbackHandles.push_back(handle);
diff --git a/services/surfaceflinger/Layer.h b/services/surfaceflinger/Layer.h
index ce4b9c4c5a..871ad5e2d4 100644
--- a/services/surfaceflinger/Layer.h
+++ b/services/surfaceflinger/Layer.h
@@ -257,8 +257,6 @@ public:
 
     bool fenceHasSignaled() const;
     void onPreComposition(nsecs_t refreshStartTime);
-    void onLayerDisplayed(ftl::SharedFuture<FenceResult>, ui::LayerStack layerStack,
-                          std::function<FenceResult(FenceResult)>&& continuation = nullptr);
 
     // Tracks mLastClientCompositionFence and gets the callback handle for this layer.
     sp<CallbackHandle> findCallbackHandle();
@@ -387,20 +385,6 @@ public:
     // from the layer.
     std::vector<ui::LayerStack> mPreviouslyPresentedLayerStacks;
 
-    struct FenceAndContinuation {
-        ftl::SharedFuture<FenceResult> future;
-        std::function<FenceResult(FenceResult)> continuation;
-
-        ftl::SharedFuture<FenceResult> chain() const {
-            if (continuation) {
-                return ftl::Future(future).then(continuation).share();
-            } else {
-                return future;
-            }
-        }
-    };
-    std::vector<FenceAndContinuation> mPreviousReleaseFenceAndContinuations;
-
     // Release fences for buffers that have not yet received a release
     // callback. A release callback may not be given when capturing
     // screenshots asynchronously. There may be no buffer update for the
diff --git a/services/surfaceflinger/LayerFE.cpp b/services/surfaceflinger/LayerFE.cpp
index b05f0eecc4..f64ba9e900 100644
--- a/services/surfaceflinger/LayerFE.cpp
+++ b/services/surfaceflinger/LayerFE.cpp
@@ -26,7 +26,6 @@
 
 #include "LayerFE.h"
 #include "SurfaceFlinger.h"
-#include "common/FlagManager.h"
 #include "ui/FenceResult.h"
 #include "ui/LayerStack.h"
 
@@ -84,8 +83,7 @@ LayerFE::~LayerFE() {
     // Ensures that no promise is left unfulfilled before the LayerFE is destroyed.
     // An unfulfilled promise could occur when a screenshot is attempted, but the
     // render area is invalid and there is no memory for the capture result.
-    if (FlagManager::getInstance().ce_fence_promise() &&
-        mReleaseFencePromiseStatus == ReleaseFencePromiseStatus::INITIALIZED) {
+    if (mReleaseFencePromiseStatus == ReleaseFencePromiseStatus::INITIALIZED) {
         setReleaseFence(Fence::NO_FENCE);
     }
 }
diff --git a/services/surfaceflinger/RegionSamplingThread.cpp b/services/surfaceflinger/RegionSamplingThread.cpp
index 06c2f26a6d..011fd9e20a 100644
--- a/services/surfaceflinger/RegionSamplingThread.cpp
+++ b/services/surfaceflinger/RegionSamplingThread.cpp
@@ -355,7 +355,7 @@ void RegionSamplingThread::captureSample() {
 
     FenceResult fenceResult;
     if (FlagManager::getInstance().single_hop_screenshot() &&
-        FlagManager::getInstance().ce_fence_promise() && mFlinger.mRenderEngine->isThreaded()) {
+        mFlinger.mRenderEngine->isThreaded()) {
         std::vector<sp<LayerFE>> layerFEs;
         auto displayState = mFlinger.getSnapshotsFromMainThread(renderAreaBuilder,
                                                                 getLayerSnapshotsFn, layerFEs);
diff --git a/services/surfaceflinger/SurfaceFlinger.cpp b/services/surfaceflinger/SurfaceFlinger.cpp
index cad179cebb..acf50f0076 100644
--- a/services/surfaceflinger/SurfaceFlinger.cpp
+++ b/services/surfaceflinger/SurfaceFlinger.cpp
@@ -2758,16 +2758,6 @@ CompositeResultsPerDisplay SurfaceFlinger::composite(
             compositionengine::Feature::kSnapshotLayerMetadata);
 
     refreshArgs.bufferIdsToUncache = std::move(mBufferIdsToUncache);
-
-    if (!FlagManager::getInstance().ce_fence_promise()) {
-        refreshArgs.layersWithQueuedFrames.reserve(mLayersWithQueuedFrames.size());
-        for (auto& [layer, _] : mLayersWithQueuedFrames) {
-            if (const auto& layerFE = layer->getCompositionEngineLayerFE(
-                        {static_cast<uint32_t>(layer->sequence)}))
-                refreshArgs.layersWithQueuedFrames.push_back(layerFE);
-        }
-    }
-
     refreshArgs.outputColorSetting = mDisplayColorSetting;
     refreshArgs.forceOutputColorMode = mForceColorMode;
 
@@ -2831,51 +2821,35 @@ CompositeResultsPerDisplay SurfaceFlinger::composite(
         layer->onPreComposition(refreshArgs.refreshStartTime);
     }
 
-    if (FlagManager::getInstance().ce_fence_promise()) {
-        for (auto& [layer, layerFE] : layers) {
-            attachReleaseFenceFutureToLayer(layer, layerFE,
-                                            layerFE->mSnapshot->outputFilter.layerStack);
-        }
-
-        refreshArgs.layersWithQueuedFrames.reserve(mLayersWithQueuedFrames.size());
-        for (auto& [layer, _] : mLayersWithQueuedFrames) {
-            if (const auto& layerFE = layer->getCompositionEngineLayerFE(
-                        {static_cast<uint32_t>(layer->sequence)})) {
-                refreshArgs.layersWithQueuedFrames.push_back(layerFE);
-                // Some layers are not displayed and do not yet have a future release fence
-                if (layerFE->getReleaseFencePromiseStatus() ==
-                            LayerFE::ReleaseFencePromiseStatus::UNINITIALIZED ||
-                    layerFE->getReleaseFencePromiseStatus() ==
-                            LayerFE::ReleaseFencePromiseStatus::FULFILLED) {
-                    // layerStack is invalid because layer is not on a display
-                    attachReleaseFenceFutureToLayer(layer.get(), layerFE.get(),
-                                                    ui::INVALID_LAYER_STACK);
-                }
-            }
-        }
-
-        mCompositionEngine->present(refreshArgs);
-        moveSnapshotsFromCompositionArgs(refreshArgs, layers);
-
-        for (auto& [layer, layerFE] : layers) {
-            CompositionResult compositionResult{layerFE->stealCompositionResult()};
-            if (compositionResult.lastClientCompositionFence) {
-                layer->setWasClientComposed(compositionResult.lastClientCompositionFence);
+    for (auto& [layer, layerFE] : layers) {
+        attachReleaseFenceFutureToLayer(layer, layerFE,
+                                        layerFE->mSnapshot->outputFilter.layerStack);
+    }
+
+    refreshArgs.layersWithQueuedFrames.reserve(mLayersWithQueuedFrames.size());
+    for (auto& [layer, _] : mLayersWithQueuedFrames) {
+        if (const auto& layerFE =
+                    layer->getCompositionEngineLayerFE({static_cast<uint32_t>(layer->sequence)})) {
+            refreshArgs.layersWithQueuedFrames.push_back(layerFE);
+            // Some layers are not displayed and do not yet have a future release fence
+            if (layerFE->getReleaseFencePromiseStatus() ==
+                        LayerFE::ReleaseFencePromiseStatus::UNINITIALIZED ||
+                layerFE->getReleaseFencePromiseStatus() ==
+                        LayerFE::ReleaseFencePromiseStatus::FULFILLED) {
+                // layerStack is invalid because layer is not on a display
+                attachReleaseFenceFutureToLayer(layer.get(), layerFE.get(),
+                                                ui::INVALID_LAYER_STACK);
             }
         }
+    }
 
-    } else {
-        mCompositionEngine->present(refreshArgs);
-        moveSnapshotsFromCompositionArgs(refreshArgs, layers);
+    mCompositionEngine->present(refreshArgs);
+    moveSnapshotsFromCompositionArgs(refreshArgs, layers);
 
-        for (auto [layer, layerFE] : layers) {
-            CompositionResult compositionResult{layerFE->stealCompositionResult()};
-            for (auto& [releaseFence, layerStack] : compositionResult.releaseFences) {
-                layer->onLayerDisplayed(std::move(releaseFence), layerStack);
-            }
-            if (compositionResult.lastClientCompositionFence) {
-                layer->setWasClientComposed(compositionResult.lastClientCompositionFence);
-            }
+    for (auto& [layer, layerFE] : layers) {
+        CompositionResult compositionResult{layerFE->stealCompositionResult()};
+        if (compositionResult.lastClientCompositionFence) {
+            layer->setWasClientComposed(compositionResult.lastClientCompositionFence);
         }
     }
 
@@ -3130,13 +3104,8 @@ void SurfaceFlinger::onCompositionPresented(PhysicalDisplayId pacesetterId,
             auto optDisplay = layerStackToDisplay.get(layerStack);
             if (optDisplay && !optDisplay->get()->isVirtual()) {
                 auto fence = getHwComposer().getPresentFence(optDisplay->get()->getPhysicalId());
-                if (FlagManager::getInstance().ce_fence_promise()) {
-                    layer->prepareReleaseCallbacks(ftl::yield<FenceResult>(fence),
-                                                   ui::INVALID_LAYER_STACK);
-                } else {
-                    layer->onLayerDisplayed(ftl::yield<FenceResult>(fence).share(),
-                                            ui::INVALID_LAYER_STACK);
-                }
+                layer->prepareReleaseCallbacks(ftl::yield<FenceResult>(fence),
+                                               ui::INVALID_LAYER_STACK);
             }
         }
         layer->releasePendingBuffer(presentTime.ns());
@@ -7219,8 +7188,7 @@ void SurfaceFlinger::captureScreenCommon(RenderAreaBuilderVariant renderAreaBuil
         return;
     }
 
-    if (FlagManager::getInstance().single_hop_screenshot() &&
-        FlagManager::getInstance().ce_fence_promise() && mRenderEngine->isThreaded()) {
+    if (FlagManager::getInstance().single_hop_screenshot() && mRenderEngine->isThreaded()) {
         std::vector<sp<LayerFE>> layerFEs;
         auto displayState =
                 getSnapshotsFromMainThread(renderAreaBuilder, getLayerSnapshotsFn, layerFEs);
@@ -7461,10 +7429,8 @@ ftl::SharedFuture<FenceResult> SurfaceFlinger::captureScreenshotLegacy(
     auto takeScreenshotFn = [=, this, renderAreaBuilder = std::move(renderAreaBuilder)]() REQUIRES(
                                     kMainThreadContext) mutable -> ftl::SharedFuture<FenceResult> {
         auto layers = getLayerSnapshotsFn();
-        if (FlagManager::getInstance().ce_fence_promise()) {
-            for (auto& [layer, layerFE] : layers) {
-                attachReleaseFenceFutureToLayer(layer, layerFE.get(), ui::INVALID_LAYER_STACK);
-            }
+        for (auto& [layer, layerFE] : layers) {
+            attachReleaseFenceFutureToLayer(layer, layerFE.get(), ui::INVALID_LAYER_STACK);
         }
         auto displayState = getDisplayStateFromRenderAreaBuilder(renderAreaBuilder);
 
@@ -7661,36 +7627,13 @@ ftl::SharedFuture<FenceResult> SurfaceFlinger::renderScreenImpl(
     // TODO(b/196334700) Once we use RenderEngineThreaded everywhere we can always defer the call
     // to CompositionEngine::present.
     ftl::SharedFuture<FenceResult> presentFuture;
-    if (FlagManager::getInstance().single_hop_screenshot() &&
-        FlagManager::getInstance().ce_fence_promise() && mRenderEngine->isThreaded()) {
+    if (FlagManager::getInstance().single_hop_screenshot() && mRenderEngine->isThreaded()) {
         presentFuture = ftl::yield(present()).share();
     } else {
         presentFuture = mRenderEngine->isThreaded() ? ftl::defer(std::move(present)).share()
                                                     : ftl::yield(present()).share();
     }
 
-    if (!FlagManager::getInstance().ce_fence_promise()) {
-        for (auto& [layer, layerFE] : layers) {
-            layer->onLayerDisplayed(presentFuture, ui::INVALID_LAYER_STACK,
-                                    [layerFE = std::move(layerFE)](FenceResult) {
-                                        if (FlagManager::getInstance()
-                                                    .screenshot_fence_preservation()) {
-                                            const auto compositionResult =
-                                                    layerFE->stealCompositionResult();
-                                            const auto& fences = compositionResult.releaseFences;
-                                            // CompositionEngine may choose to cull layers that
-                                            // aren't visible, so pass a non-fence.
-                                            return fences.empty() ? Fence::NO_FENCE
-                                                                  : fences.back().first.get();
-                                        } else {
-                                            return layerFE->stealCompositionResult()
-                                                    .releaseFences.back()
-                                                    .first.get();
-                                        }
-                                    });
-        }
-    }
-
     return presentFuture;
 }
 
diff --git a/services/surfaceflinger/TransactionCallbackInvoker.cpp b/services/surfaceflinger/TransactionCallbackInvoker.cpp
index c6856aea75..de4825ba62 100644
--- a/services/surfaceflinger/TransactionCallbackInvoker.cpp
+++ b/services/surfaceflinger/TransactionCallbackInvoker.cpp
@@ -28,7 +28,6 @@
 #include "Utils/FenceUtils.h"
 
 #include <binder/IInterface.h>
-#include <common/FlagManager.h>
 #include <common/trace.h>
 #include <utils/RefBase.h>
 
@@ -127,14 +126,8 @@ status_t TransactionCallbackInvoker::addCallbackHandle(const sp<CallbackHandle>&
     if (surfaceControl) {
         sp<Fence> prevFence = nullptr;
 
-        if (FlagManager::getInstance().ce_fence_promise()) {
-            for (auto& future : handle->previousReleaseFences) {
-                mergeFence(handle->name.c_str(), future.get().value_or(Fence::NO_FENCE), prevFence);
-            }
-        } else {
-            for (const auto& future : handle->previousSharedReleaseFences) {
-                mergeFence(handle->name.c_str(), future.get().value_or(Fence::NO_FENCE), prevFence);
-            }
+        for (auto& future : handle->previousReleaseFences) {
+            mergeFence(handle->name.c_str(), future.get().value_or(Fence::NO_FENCE), prevFence);
         }
 
         handle->previousReleaseFence = prevFence;
diff --git a/services/surfaceflinger/TransactionCallbackInvoker.h b/services/surfaceflinger/TransactionCallbackInvoker.h
index 14a7487156..d81d8d07f4 100644
--- a/services/surfaceflinger/TransactionCallbackInvoker.h
+++ b/services/surfaceflinger/TransactionCallbackInvoker.h
@@ -43,7 +43,6 @@ public:
     std::string name;
     sp<Fence> previousReleaseFence;
     std::vector<ftl::Future<FenceResult>> previousReleaseFences;
-    std::vector<ftl::SharedFuture<FenceResult>> previousSharedReleaseFences;
     std::variant<nsecs_t, sp<Fence>> acquireTimeOrFence = -1;
     nsecs_t latchTime = -1;
     std::optional<uint32_t> transformHint = std::nullopt;
diff --git a/services/surfaceflinger/common/FlagManager.cpp b/services/surfaceflinger/common/FlagManager.cpp
index 12d6138675..a331491be6 100644
--- a/services/surfaceflinger/common/FlagManager.cpp
+++ b/services/surfaceflinger/common/FlagManager.cpp
@@ -132,7 +132,6 @@ void FlagManager::dump(std::string& result) const {
     DUMP_READ_ONLY_FLAG(fp16_client_target);
     DUMP_READ_ONLY_FLAG(game_default_frame_rate);
     DUMP_READ_ONLY_FLAG(enable_layer_command_batching);
-    DUMP_READ_ONLY_FLAG(screenshot_fence_preservation);
     DUMP_READ_ONLY_FLAG(vulkan_renderengine);
     DUMP_READ_ONLY_FLAG(renderable_buffer_usage);
     DUMP_READ_ONLY_FLAG(vrr_bugfix_24q4);
@@ -140,7 +139,6 @@ void FlagManager::dump(std::string& result) const {
     DUMP_READ_ONLY_FLAG(restore_blur_step);
     DUMP_READ_ONLY_FLAG(dont_skip_on_early_ro);
     DUMP_READ_ONLY_FLAG(protected_if_client);
-    DUMP_READ_ONLY_FLAG(ce_fence_promise);
     DUMP_READ_ONLY_FLAG(idle_screen_refresh_rate_timeout);
     DUMP_READ_ONLY_FLAG(graphite_renderengine);
     DUMP_READ_ONLY_FLAG(filter_frames_before_trace_starts);
@@ -239,7 +237,6 @@ FLAG_MANAGER_READ_ONLY_FLAG(display_protected, "")
 FLAG_MANAGER_READ_ONLY_FLAG(fp16_client_target, "debug.sf.fp16_client_target")
 FLAG_MANAGER_READ_ONLY_FLAG(game_default_frame_rate, "")
 FLAG_MANAGER_READ_ONLY_FLAG(enable_layer_command_batching, "debug.sf.enable_layer_command_batching")
-FLAG_MANAGER_READ_ONLY_FLAG(screenshot_fence_preservation, "debug.sf.screenshot_fence_preservation")
 FLAG_MANAGER_READ_ONLY_FLAG(vulkan_renderengine, "debug.renderengine.vulkan")
 FLAG_MANAGER_READ_ONLY_FLAG(renderable_buffer_usage, "")
 FLAG_MANAGER_READ_ONLY_FLAG(restore_blur_step, "debug.renderengine.restore_blur_step")
@@ -247,7 +244,6 @@ FLAG_MANAGER_READ_ONLY_FLAG(dont_skip_on_early_ro, "")
 FLAG_MANAGER_READ_ONLY_FLAG(protected_if_client, "")
 FLAG_MANAGER_READ_ONLY_FLAG(vrr_bugfix_24q4, "");
 FLAG_MANAGER_READ_ONLY_FLAG(vrr_bugfix_dropped_frame, "")
-FLAG_MANAGER_READ_ONLY_FLAG(ce_fence_promise, "");
 FLAG_MANAGER_READ_ONLY_FLAG(graphite_renderengine, "debug.renderengine.graphite")
 FLAG_MANAGER_READ_ONLY_FLAG(filter_frames_before_trace_starts, "")
 FLAG_MANAGER_READ_ONLY_FLAG(latch_unsignaled_with_auto_refresh_changed, "");
diff --git a/services/surfaceflinger/common/include/common/FlagManager.h b/services/surfaceflinger/common/include/common/FlagManager.h
index a1be19421b..daaf33870d 100644
--- a/services/surfaceflinger/common/include/common/FlagManager.h
+++ b/services/surfaceflinger/common/include/common/FlagManager.h
@@ -70,7 +70,6 @@ public:
     bool fp16_client_target() const;
     bool game_default_frame_rate() const;
     bool enable_layer_command_batching() const;
-    bool screenshot_fence_preservation() const;
     bool vulkan_renderengine() const;
     bool vrr_bugfix_24q4() const;
     bool vrr_bugfix_dropped_frame() const;
@@ -78,7 +77,6 @@ public:
     bool restore_blur_step() const;
     bool dont_skip_on_early_ro() const;
     bool protected_if_client() const;
-    bool ce_fence_promise() const;
     bool idle_screen_refresh_rate_timeout() const;
     bool graphite_renderengine() const;
     bool filter_frames_before_trace_starts() const;
diff --git a/services/surfaceflinger/tests/TransactionTestHarnesses.h b/services/surfaceflinger/tests/TransactionTestHarnesses.h
index 67a524799d..bf5957a89a 100644
--- a/services/surfaceflinger/tests/TransactionTestHarnesses.h
+++ b/services/surfaceflinger/tests/TransactionTestHarnesses.h
@@ -17,7 +17,6 @@
 #define ANDROID_TRANSACTION_TEST_HARNESSES
 
 #include <com_android_graphics_libgui_flags.h>
-#include <common/FlagManager.h>
 #include <ui/DisplayState.h>
 
 #include "LayerTransactionTest.h"
@@ -96,12 +95,8 @@ public:
 #endif // COM_ANDROID_GRAPHICS_LIBGUI_FLAGS(WB_CONSUMER_BASE_OWNS_BQ)
                 t.setDisplayProjection(vDisplay, displayState.orientation,
                                        Rect(displayState.layerStackSpaceRect), Rect(resolution));
-                if (FlagManager::getInstance().ce_fence_promise()) {
-                    t.setDisplayLayerStack(vDisplay, layerStack);
-                    t.setLayerStack(mirrorSc, layerStack);
-                } else {
-                    t.setDisplayLayerStack(vDisplay, ui::DEFAULT_LAYER_STACK);
-                }
+                t.setDisplayLayerStack(vDisplay, layerStack);
+                t.setLayerStack(mirrorSc, layerStack);
                 t.apply();
                 SurfaceComposerClient::Transaction().apply(true);
 
@@ -121,10 +116,8 @@ public:
                 // CompositionEngine::present may attempt to be called on the same
                 // display multiple times. The layerStack is set to invalid here so
                 // that the display is ignored if that scenario occurs.
-                if (FlagManager::getInstance().ce_fence_promise()) {
-                    t.setLayerStack(mirrorSc, ui::INVALID_LAYER_STACK);
-                    t.apply(true);
-                }
+                t.setLayerStack(mirrorSc, ui::INVALID_LAYER_STACK);
+                t.apply(true);
                 SurfaceComposerClient::destroyVirtualDisplay(vDisplay);
                 return sc;
         }