Merge "Add explicit clearSyncTransaction instead of passing in null" into udc-dev

3 files changed, 74 insertions, 31 deletions

diff --git a/libs/gui/BLASTBufferQueue.cpp b/libs/gui/BLASTBufferQueue.cpp
index fd42b33e49..5c324b29cd 100644
--- a/libs/gui/BLASTBufferQueue.cpp
+++ b/libs/gui/BLASTBufferQueue.cpp
@@ -801,34 +801,24 @@ void BLASTBufferQueue::onFrameCancelled(const uint64_t bufferId) {
     mDequeueTimestamps.erase(bufferId);
 };
 
-void BLASTBufferQueue::syncNextTransaction(
+bool BLASTBufferQueue::syncNextTransaction(
         std::function<void(SurfaceComposerClient::Transaction*)> callback,
         bool acquireSingleBuffer) {
-    std::function<void(SurfaceComposerClient::Transaction*)> prevCallback = nullptr;
-    SurfaceComposerClient::Transaction* prevTransaction = nullptr;
-
-    {
-        std::lock_guard _lock{mMutex};
-        BBQ_TRACE();
-        // We're about to overwrite the previous call so we should invoke that callback
-        // immediately.
-        if (mTransactionReadyCallback) {
-            prevCallback = mTransactionReadyCallback;
-            prevTransaction = mSyncTransaction;
-        }
+    LOG_ALWAYS_FATAL_IF(!callback,
+                        "BLASTBufferQueue: callback passed in to syncNextTransaction must not be "
+                        "NULL");
 
-        mTransactionReadyCallback = callback;
-        if (callback) {
-            mSyncTransaction = new SurfaceComposerClient::Transaction();
-        } else {
-            mSyncTransaction = nullptr;
-        }
-        mAcquireSingleBuffer = mTransactionReadyCallback ? acquireSingleBuffer : true;
+    std::lock_guard _lock{mMutex};
+    BBQ_TRACE();
+    if (mTransactionReadyCallback) {
+        ALOGW("Attempting to overwrite transaction callback in syncNextTransaction");
+        return false;
     }
 
-    if (prevCallback) {
-        prevCallback(prevTransaction);
-    }
+    mTransactionReadyCallback = callback;
+    mSyncTransaction = new SurfaceComposerClient::Transaction();
+    mAcquireSingleBuffer = acquireSingleBuffer;
+    return true;
 }
 
 void BLASTBufferQueue::stopContinuousSyncTransaction() {
@@ -836,20 +826,35 @@ void BLASTBufferQueue::stopContinuousSyncTransaction() {
     SurfaceComposerClient::Transaction* prevTransaction = nullptr;
     {
         std::lock_guard _lock{mMutex};
-        bool invokeCallback = mTransactionReadyCallback && !mAcquireSingleBuffer;
-        if (invokeCallback) {
-            prevCallback = mTransactionReadyCallback;
-            prevTransaction = mSyncTransaction;
+        if (mAcquireSingleBuffer || !mTransactionReadyCallback) {
+            ALOGW("Attempting to stop continuous sync when none are active");
+            return;
         }
+
+        prevCallback = mTransactionReadyCallback;
+        prevTransaction = mSyncTransaction;
+
         mTransactionReadyCallback = nullptr;
         mSyncTransaction = nullptr;
         mAcquireSingleBuffer = true;
     }
+
     if (prevCallback) {
         prevCallback(prevTransaction);
     }
 }
 
+void BLASTBufferQueue::clearSyncTransaction() {
+    std::lock_guard _lock{mMutex};
+    if (!mAcquireSingleBuffer) {
+        ALOGW("Attempting to clear sync transaction when none are active");
+        return;
+    }
+
+    mTransactionReadyCallback = nullptr;
+    mSyncTransaction = nullptr;
+}
+
 bool BLASTBufferQueue::rejectBuffer(const BufferItem& item) {
     if (item.mScalingMode != NATIVE_WINDOW_SCALING_MODE_FREEZE) {
         // Only reject buffers if scaling mode is freeze.
diff --git a/libs/gui/include/gui/BLASTBufferQueue.h b/libs/gui/include/gui/BLASTBufferQueue.h
index 69e9f8a4fb..a49a85984f 100644
--- a/libs/gui/include/gui/BLASTBufferQueue.h
+++ b/libs/gui/include/gui/BLASTBufferQueue.h
@@ -97,9 +97,10 @@ public:
     void releaseBufferCallbackLocked(const ReleaseCallbackId& id, const sp<Fence>& releaseFence,
                                      std::optional<uint32_t> currentMaxAcquiredBufferCount,
                                      bool fakeRelease) REQUIRES(mMutex);
-    void syncNextTransaction(std::function<void(SurfaceComposerClient::Transaction*)> callback,
+    bool syncNextTransaction(std::function<void(SurfaceComposerClient::Transaction*)> callback,
                              bool acquireSingleBuffer = true);
     void stopContinuousSyncTransaction();
+    void clearSyncTransaction();
 
     void mergeWithNextTransaction(SurfaceComposerClient::Transaction* t, uint64_t frameNumber);
     void applyPendingTransactions(uint64_t frameNumber);
diff --git a/libs/gui/tests/BLASTBufferQueue_test.cpp b/libs/gui/tests/BLASTBufferQueue_test.cpp
index b9e75be57d..7067c111a3 100644
--- a/libs/gui/tests/BLASTBufferQueue_test.cpp
+++ b/libs/gui/tests/BLASTBufferQueue_test.cpp
@@ -117,15 +117,17 @@ public:
         mBlastBufferQueueAdapter->syncNextTransaction(callback, acquireSingleBuffer);
     }
 
-    void syncNextTransaction(std::function<void(Transaction*)> callback,
+    bool syncNextTransaction(std::function<void(Transaction*)> callback,
                              bool acquireSingleBuffer = true) {
-        mBlastBufferQueueAdapter->syncNextTransaction(callback, acquireSingleBuffer);
+        return mBlastBufferQueueAdapter->syncNextTransaction(callback, acquireSingleBuffer);
     }
 
     void stopContinuousSyncTransaction() {
         mBlastBufferQueueAdapter->stopContinuousSyncTransaction();
     }
 
+    void clearSyncTransaction() { mBlastBufferQueueAdapter->clearSyncTransaction(); }
+
     int getWidth() { return mBlastBufferQueueAdapter->mSize.width; }
 
     int getHeight() { return mBlastBufferQueueAdapter->mSize.height; }
@@ -1111,7 +1113,11 @@ TEST_F(BLASTBufferQueueTest, SyncNextTransactionOverwrite) {
     ASSERT_NE(nullptr, adapter.getTransactionReadyCallback());
 
     auto callback2 = [](Transaction*) {};
-    adapter.syncNextTransaction(callback2);
+    ASSERT_FALSE(adapter.syncNextTransaction(callback2));
+
+    sp<IGraphicBufferProducer> igbProducer;
+    setUpProducer(adapter, igbProducer);
+    queueBuffer(igbProducer, 0, 255, 0, 0);
 
     std::unique_lock<std::mutex> lock(mutex);
     if (!receivedCallback) {
@@ -1123,6 +1129,37 @@ TEST_F(BLASTBufferQueueTest, SyncNextTransactionOverwrite) {
     ASSERT_TRUE(receivedCallback);
 }
 
+TEST_F(BLASTBufferQueueTest, ClearSyncTransaction) {
+    std::mutex mutex;
+    std::condition_variable callbackReceivedCv;
+    bool receivedCallback = false;
+
+    BLASTBufferQueueHelper adapter(mSurfaceControl, mDisplayWidth, mDisplayHeight);
+    ASSERT_EQ(nullptr, adapter.getTransactionReadyCallback());
+    auto callback = [&](Transaction*) {
+        std::unique_lock<std::mutex> lock(mutex);
+        receivedCallback = true;
+        callbackReceivedCv.notify_one();
+    };
+    adapter.syncNextTransaction(callback);
+    ASSERT_NE(nullptr, adapter.getTransactionReadyCallback());
+
+    adapter.clearSyncTransaction();
+
+    sp<IGraphicBufferProducer> igbProducer;
+    setUpProducer(adapter, igbProducer);
+    queueBuffer(igbProducer, 0, 255, 0, 0);
+
+    std::unique_lock<std::mutex> lock(mutex);
+    if (!receivedCallback) {
+        ASSERT_EQ(callbackReceivedCv.wait_for(lock, std::chrono::seconds(3)),
+                  std::cv_status::timeout)
+                << "did not receive callback";
+    }
+
+    ASSERT_FALSE(receivedCallback);
+}
+
 TEST_F(BLASTBufferQueueTest, SyncNextTransactionDropBuffer) {
     uint8_t r = 255;
     uint8_t g = 0;