diff --git a/services/surfaceflinger/tests/unittests/TestableSurfaceFlinger.h b/services/surfaceflinger/tests/unittests/TestableSurfaceFlinger.h
index 60285f9..eae5f82 100644
--- a/services/surfaceflinger/tests/unittests/TestableSurfaceFlinger.h
+++ b/services/surfaceflinger/tests/unittests/TestableSurfaceFlinger.h
@@ -421,7 +421,7 @@
         return mFlinger->SurfaceFlinger::getDisplayNativePrimaries(displayToken, primaries);
     }
 
-    auto& getTransactionQueue() { return mFlinger->mTransactionQueue; }
+    auto& getTransactionQueue() { return mFlinger->mLocklessTransactionQueue; }
     auto& getPendingTransactionQueue() { return mFlinger->mPendingTransactionQueues; }
     auto& getTransactionCommittedSignals() { return mFlinger->mTransactionCommittedSignals; }
 
diff --git a/services/surfaceflinger/tests/unittests/TransactionApplicationTest.cpp b/services/surfaceflinger/tests/unittests/TransactionApplicationTest.cpp
index 84f1170..b2da34e 100644
--- a/services/surfaceflinger/tests/unittests/TransactionApplicationTest.cpp
+++ b/services/surfaceflinger/tests/unittests/TransactionApplicationTest.cpp
@@ -117,7 +117,7 @@
     }
 
     void NotPlacedOnTransactionQueue(uint32_t flags) {
-        ASSERT_EQ(0u, mFlinger.getTransactionQueue().size());
+        ASSERT_TRUE(mFlinger.getTransactionQueue().isEmpty());
         EXPECT_CALL(*mFlinger.scheduler(), scheduleFrame()).Times(1);
         TransactionInfo transaction;
         setupSingle(transaction, flags,
@@ -140,12 +140,12 @@
             EXPECT_LE(returnedTime, applicationTime + mFlinger.getAnimationTransactionTimeout());
         }
         // Each transaction should have been placed on the transaction queue
-        auto transactionQueue = mFlinger.getTransactionQueue();
-        EXPECT_EQ(1u, transactionQueue.size());
+        auto& transactionQueue = mFlinger.getTransactionQueue();
+        EXPECT_FALSE(transactionQueue.isEmpty());
     }
 
     void PlaceOnTransactionQueue(uint32_t flags) {
-        ASSERT_EQ(0u, mFlinger.getTransactionQueue().size());
+        ASSERT_TRUE(mFlinger.getTransactionQueue().isEmpty());
         EXPECT_CALL(*mFlinger.scheduler(), scheduleFrame()).Times(1);
 
         // first check will see desired present time has not passed,
@@ -171,12 +171,12 @@
                       applicationSentTime + mFlinger.getAnimationTransactionTimeout());
         }
         // This transaction should have been placed on the transaction queue
-        auto transactionQueue = mFlinger.getTransactionQueue();
-        EXPECT_EQ(1u, transactionQueue.size());
+        auto& transactionQueue = mFlinger.getTransactionQueue();
+        EXPECT_FALSE(transactionQueue.isEmpty());
     }
 
     void BlockedByPriorTransaction(uint32_t flags) {
-        ASSERT_EQ(0u, mFlinger.getTransactionQueue().size());
+        ASSERT_TRUE(mFlinger.getTransactionQueue().isEmpty());
         nsecs_t time = systemTime();
         EXPECT_CALL(*mFlinger.scheduler(), scheduleFrame()).Times(2);
 
@@ -239,8 +239,8 @@
     int mTransactionNumber = 0;
 };
 
-TEST_F(TransactionApplicationTest, Flush_RemovesFromQueue) {
-    ASSERT_EQ(0u, mFlinger.getTransactionQueue().size());
+TEST_F(TransactionApplicationTest, AddToPendingQueue) {
+    ASSERT_TRUE(mFlinger.getTransactionQueue().isEmpty());
     EXPECT_CALL(*mFlinger.scheduler(), scheduleFrame()).Times(1);
 
     TransactionInfo transactionA; // transaction to go on pending queue
@@ -253,10 +253,27 @@
                                  mHasListenerCallbacks, mCallbacks, transactionA.id);
 
     auto& transactionQueue = mFlinger.getTransactionQueue();
-    ASSERT_EQ(1u, transactionQueue.size());
+    ASSERT_FALSE(transactionQueue.isEmpty());
 
-    auto& transactionState = transactionQueue.front();
+    auto transactionState = transactionQueue.pop().value();
     checkEqual(transactionA, transactionState);
+}
+
+TEST_F(TransactionApplicationTest, Flush_RemovesFromQueue) {
+    ASSERT_TRUE(mFlinger.getTransactionQueue().isEmpty());
+    EXPECT_CALL(*mFlinger.scheduler(), scheduleFrame()).Times(1);
+
+    TransactionInfo transactionA; // transaction to go on pending queue
+    setupSingle(transactionA, /*flags*/ 0, /*desiredPresentTime*/ s2ns(1), false,
+                FrameTimelineInfo{});
+    mFlinger.setTransactionState(transactionA.frameTimelineInfo, transactionA.states,
+                                 transactionA.displays, transactionA.flags, transactionA.applyToken,
+                                 transactionA.inputWindowCommands, transactionA.desiredPresentTime,
+                                 transactionA.isAutoTimestamp, transactionA.uncacheBuffer,
+                                 mHasListenerCallbacks, mCallbacks, transactionA.id);
+
+    auto& transactionQueue = mFlinger.getTransactionQueue();
+    ASSERT_FALSE(transactionQueue.isEmpty());
 
     // because flushing uses the cached expected present time, we send an empty
     // transaction here (sending a null applyToken to fake it as from a
@@ -272,7 +289,7 @@
     // passed
     mFlinger.flushTransactionQueues();
 
-    EXPECT_EQ(0u, transactionQueue.size());
+    EXPECT_TRUE(mFlinger.getTransactionQueue().isEmpty());
 }
 
 TEST_F(TransactionApplicationTest, NotPlacedOnTransactionQueue_Synchronous) {
@@ -306,7 +323,9 @@
     void TearDown() override {
         // Clear all transaction queues to release all transactions we sent
         // in the tests. Otherwise, gmock complains about memory leaks.
-        mFlinger.getTransactionQueue().clear();
+        while (!mFlinger.getTransactionQueue().isEmpty()) {
+            mFlinger.getTransactionQueue().pop();
+        }
         mFlinger.getPendingTransactionQueue().clear();
         mFlinger.getTransactionCommittedSignals().clear();
         mFlinger.commitTransactionsLocked(eTransactionMask);
@@ -358,7 +377,7 @@
     void setTransactionStates(const std::vector<TransactionInfo>& transactions,
                               size_t expectedTransactionsApplied,
                               size_t expectedTransactionsPending) {
-        EXPECT_EQ(0u, mFlinger.getTransactionQueue().size());
+        EXPECT_TRUE(mFlinger.getTransactionQueue().isEmpty());
         EXPECT_EQ(0u, mFlinger.getPendingTransactionQueue().size());
 
         for (const auto& transaction : transactions) {
@@ -370,7 +389,7 @@
                                          mHasListenerCallbacks, mCallbacks, transaction.id);
         }
         mFlinger.flushTransactionQueues();
-        EXPECT_EQ(0u, mFlinger.getTransactionQueue().size());
+        EXPECT_TRUE(mFlinger.getTransactionQueue().isEmpty());
         EXPECT_EQ(expectedTransactionsPending, mFlinger.getPendingTransactionQueue().size());
         EXPECT_EQ(expectedTransactionsApplied, mFlinger.getTransactionCommittedSignals().size());
     }