Merge "Ensure transaction commit callbacks are called at most once." into main (33fe363b) · Commits · e / os / platform_frameworks_native

libs/gui/SurfaceComposerClient.cpp

+5 −1

Original line number	Diff line number	Diff line
		@@ -377,7 +377,6 @@ void TransactionCompletedListener::onTransactionCompleted(ListenerStats listener
		}
		auto& [callbackFunction, callbackSurfaceControls] = callbacksMap[callbackId];
		if (!callbackFunction) {
		ALOGE("cannot call null callback function, skipping");
		continue;
		}
		std::vector<SurfaceControlStats> surfaceControlStats;
		@@ -394,6 +393,11 @@ void TransactionCompletedListener::onTransactionCompleted(ListenerStats listener

		callbackFunction(transactionStats.latchTime, transactionStats.presentFence,
		surfaceControlStats);

		// More than one transaction may contain the same callback id. Erase the callback from
		// the map to ensure that it is only called once. This can happen if transactions are
		// parcelled out of process and applied in both processes.
		callbacksMap.erase(callbackId);
		}

		// handle on complete callbacks

+29 −0

Original line number	Diff line number	Diff line
		@@ -184,6 +184,35 @@ TEST_F(LayerTransactionTest, BufferTakesPriorityOverColor) {
		}
		}

		TEST_F(LayerTransactionTest, CommitCallbackCalledOnce) {
		auto callCount = 0;
		auto commitCallback =
		[&callCount](void* /* context /, nsecs_t / latchTime */,
		const sp<Fence>& /* presentFence */,
		const std::vector<SurfaceControlStats>& /* stats */) mutable {
		callCount++;
		};

		// Create two transactions that both contain the same callback id.
		Transaction t1;
		t1.addTransactionCommittedCallback(commitCallback, nullptr);
		Parcel parcel;
		t1.writeToParcel(&parcel);
		parcel.setDataPosition(0);
		Transaction t2;
		t2.readFromParcel(&parcel);

		// Apply the two transactions. There is a race here as we can't guarantee that the two
		// transactions will be applied within the same SurfaceFlinger commit. If the transactions are
		// applied within the same commit then we verify that callback ids are deduplicated within a
		// single commit. Otherwise, we verify that commit callbacks are deduplicated across separate
		// commits.
		t1.apply();
		t2.apply(/synchronous=/true);

		ASSERT_EQ(callCount, 1);
		}

		} // namespace android

		// TODO(b/129481165): remove the #pragma below and fix conversion issues