diff --git a/services/inputflinger/reader/InputDevice.cpp b/services/inputflinger/reader/InputDevice.cpp
index b86906b..ec8a443 100644
--- a/services/inputflinger/reader/InputDevice.cpp
+++ b/services/inputflinger/reader/InputDevice.cpp
@@ -203,7 +203,7 @@
 
     using Change = InputReaderConfiguration::Change;
 
-    if (!isIgnored()) {
+    if (!changes.any() || !isIgnored()) {
         // Full configuration should happen the first time configure is called
         // and when the device type is changed. Changing a device type can
         // affect various other parameters so should result in a
@@ -503,9 +503,9 @@
         classes.test(InputDeviceClass::TOUCH_MT) && !isSonyDualShock4Touchpad) {
         mappers.push_back(std::make_unique<TouchpadInputMapper>(contextPtr, readerConfig));
     } else if (classes.test(InputDeviceClass::TOUCH_MT)) {
-        mappers.push_back(std::make_unique<MultiTouchInputMapper>(contextPtr, readerConfig));
+        mappers.push_back(createInputMapper<MultiTouchInputMapper>(contextPtr, readerConfig));
     } else if (classes.test(InputDeviceClass::TOUCH)) {
-        mappers.push_back(std::make_unique<SingleTouchInputMapper>(contextPtr, readerConfig));
+        mappers.push_back(createInputMapper<SingleTouchInputMapper>(contextPtr, readerConfig));
     }
 
     // Joystick-like devices.
diff --git a/services/inputflinger/reader/include/InputDevice.h b/services/inputflinger/reader/include/InputDevice.h
index 6303546..0b8a608 100644
--- a/services/inputflinger/reader/include/InputDevice.h
+++ b/services/inputflinger/reader/include/InputDevice.h
@@ -149,6 +149,16 @@
         return *mapper;
     }
 
+    template <class T, typename... Args>
+    T& constructAndAddMapper(int32_t eventHubId, Args... args) {
+        // create mapper
+        auto& devicePair = mDevices[eventHubId];
+        auto& deviceContext = devicePair.first;
+        auto& mappers = devicePair.second;
+        mappers.push_back(createInputMapper<T>(*deviceContext, args...));
+        return static_cast<T&>(*mappers.back());
+    }
+
     // construct and add a controller to the input device
     template <class T>
     T& addController(int32_t eventHubId) {
diff --git a/services/inputflinger/reader/mapper/InputMapper.h b/services/inputflinger/reader/mapper/InputMapper.h
index f017317..06de4c2 100644
--- a/services/inputflinger/reader/mapper/InputMapper.h
+++ b/services/inputflinger/reader/mapper/InputMapper.h
@@ -25,6 +25,20 @@
 #include "VibrationElement.h"
 
 namespace android {
+/**
+ * This is the factory method that must be used to create any InputMapper
+ */
+template <class T, class... Args>
+std::unique_ptr<T> createInputMapper(InputDeviceContext& deviceContext,
+                                     const InputReaderConfiguration& readerConfig, Args... args) {
+    // Using `new` to access non-public constructors.
+    std::unique_ptr<T> mapper(new T(deviceContext, readerConfig, args...));
+    // We need to reset and configure the mapper to ensure it is ready to process event
+    nsecs_t now = systemTime(SYSTEM_TIME_MONOTONIC);
+    std::list<NotifyArgs> unused = mapper->reset(now);
+    unused += mapper->reconfigure(now, readerConfig, /*changes=*/{});
+    return mapper;
+}
 
 /* An input mapper transforms raw input events into cooked event data.
  * A single input device can have multiple associated input mappers in order to interpret
@@ -39,8 +53,15 @@
  */
 class InputMapper {
 public:
-    explicit InputMapper(InputDeviceContext& deviceContext,
-                         const InputReaderConfiguration& readerConfig);
+    /**
+     * Subclasses must either provide a public constructor
+     * or must be-friend the factory method.
+     */
+    template <class T, class... Args>
+    friend std::unique_ptr<T> createInputMapper(InputDeviceContext& deviceContext,
+                                                const InputReaderConfiguration& readerConfig,
+                                                Args... args);
+
     virtual ~InputMapper();
 
     inline int32_t getDeviceId() { return mDeviceContext.getId(); }
@@ -102,6 +123,9 @@
 protected:
     InputDeviceContext& mDeviceContext;
 
+    explicit InputMapper(InputDeviceContext& deviceContext,
+                         const InputReaderConfiguration& readerConfig);
+
     status_t getAbsoluteAxisInfo(int32_t axis, RawAbsoluteAxisInfo* axisInfo);
     void bumpGeneration();
 
diff --git a/services/inputflinger/reader/mapper/MultiTouchInputMapper.h b/services/inputflinger/reader/mapper/MultiTouchInputMapper.h
index a617420..1d788df 100644
--- a/services/inputflinger/reader/mapper/MultiTouchInputMapper.h
+++ b/services/inputflinger/reader/mapper/MultiTouchInputMapper.h
@@ -23,8 +23,11 @@
 
 class MultiTouchInputMapper : public TouchInputMapper {
 public:
-    explicit MultiTouchInputMapper(InputDeviceContext& deviceContext,
-                                   const InputReaderConfiguration& readerConfig);
+    template <class T, class... Args>
+    friend std::unique_ptr<T> createInputMapper(InputDeviceContext& deviceContext,
+                                                const InputReaderConfiguration& readerConfig,
+                                                Args... args);
+
     ~MultiTouchInputMapper() override;
 
     [[nodiscard]] std::list<NotifyArgs> reset(nsecs_t when) override;
@@ -36,6 +39,8 @@
     bool hasStylus() const override;
 
 private:
+    explicit MultiTouchInputMapper(InputDeviceContext& deviceContext,
+                                   const InputReaderConfiguration& readerConfig);
     // simulate_stylus_with_touch is a debug mode that converts all finger pointers reported by this
     // mapper's touchscreen into stylus pointers, and adds SOURCE_STYLUS to the input device.
     // It is used to simulate stylus events for debugging and testing on a device that does not
diff --git a/services/inputflinger/reader/mapper/SingleTouchInputMapper.h b/services/inputflinger/reader/mapper/SingleTouchInputMapper.h
index 9341007..7726bfb 100644
--- a/services/inputflinger/reader/mapper/SingleTouchInputMapper.h
+++ b/services/inputflinger/reader/mapper/SingleTouchInputMapper.h
@@ -23,8 +23,11 @@
 
 class SingleTouchInputMapper : public TouchInputMapper {
 public:
-    explicit SingleTouchInputMapper(InputDeviceContext& deviceContext,
-                                    const InputReaderConfiguration& readerConfig);
+    template <class T, class... Args>
+    friend std::unique_ptr<T> createInputMapper(InputDeviceContext& deviceContext,
+                                                const InputReaderConfiguration& readerConfig,
+                                                Args... args);
+
     ~SingleTouchInputMapper() override;
 
     [[nodiscard]] std::list<NotifyArgs> reset(nsecs_t when) override;
@@ -37,6 +40,8 @@
 
 private:
     SingleTouchMotionAccumulator mSingleTouchMotionAccumulator;
+    explicit SingleTouchInputMapper(InputDeviceContext& deviceContext,
+                                    const InputReaderConfiguration& readerConfig);
 };
 
 } // namespace android
diff --git a/services/inputflinger/reader/mapper/TouchInputMapper.cpp b/services/inputflinger/reader/mapper/TouchInputMapper.cpp
index c72a263..f4d50b8 100644
--- a/services/inputflinger/reader/mapper/TouchInputMapper.cpp
+++ b/services/inputflinger/reader/mapper/TouchInputMapper.cpp
@@ -125,8 +125,7 @@
                                    const InputReaderConfiguration& readerConfig)
       : InputMapper(deviceContext, readerConfig),
         mTouchButtonAccumulator(deviceContext),
-        mConfig(readerConfig),
-        mParameters(computeParameters(deviceContext)) {}
+        mConfig(readerConfig) {}
 
 TouchInputMapper::~TouchInputMapper() {}
 
diff --git a/services/inputflinger/reader/mapper/TouchInputMapper.h b/services/inputflinger/reader/mapper/TouchInputMapper.h
index 7141924..d8b59ca 100644
--- a/services/inputflinger/reader/mapper/TouchInputMapper.h
+++ b/services/inputflinger/reader/mapper/TouchInputMapper.h
@@ -146,8 +146,6 @@
 
 class TouchInputMapper : public InputMapper {
 public:
-    explicit TouchInputMapper(InputDeviceContext& deviceContext,
-                              const InputReaderConfiguration& readerConfig);
     ~TouchInputMapper() override;
 
     uint32_t getSources() const override;
@@ -358,25 +356,28 @@
     nsecs_t mExternalStylusFusionTimeout;
     bool mExternalStylusDataPending;
     // A subset of the buttons in mCurrentRawState that came from an external stylus.
-    int32_t mExternalStylusButtonsApplied;
+    int32_t mExternalStylusButtonsApplied{0};
 
     // True if we sent a HOVER_ENTER event.
-    bool mSentHoverEnter;
+    bool mSentHoverEnter{false};
 
     // Have we assigned pointer IDs for this stream
-    bool mHavePointerIds;
+    bool mHavePointerIds{false};
 
     // Is the current stream of direct touch events aborted
-    bool mCurrentMotionAborted;
+    bool mCurrentMotionAborted{false};
 
     // The time the primary pointer last went down.
-    nsecs_t mDownTime;
+    nsecs_t mDownTime{0};
 
     // The pointer controller, or null if the device is not a pointer.
     std::shared_ptr<PointerControllerInterface> mPointerController;
 
     std::vector<VirtualKey> mVirtualKeys;
 
+    explicit TouchInputMapper(InputDeviceContext& deviceContext,
+                              const InputReaderConfiguration& readerConfig);
+
     virtual void dumpParameters(std::string& dump);
     virtual void configureRawPointerAxes();
     virtual void dumpRawPointerAxes(std::string& dump);
@@ -513,7 +514,7 @@
         STYLUS,
         MOUSE,
     };
-    PointerUsage mPointerUsage;
+    PointerUsage mPointerUsage{PointerUsage::NONE};
 
     struct PointerGesture {
         enum class Mode {
diff --git a/services/inputflinger/tests/InputMapperTest.h b/services/inputflinger/tests/InputMapperTest.h
index d969034..2b6655c 100644
--- a/services/inputflinger/tests/InputMapperTest.h
+++ b/services/inputflinger/tests/InputMapperTest.h
@@ -73,6 +73,17 @@
         return mapper;
     }
 
+    template <class T, typename... Args>
+    T& constructAndAddMapper(Args... args) {
+        // ensure a device entry exists for this eventHubId
+        mDevice->addEmptyEventHubDevice(EVENTHUB_ID);
+        // configure the empty device
+        configureDevice(/*changes=*/{});
+
+        return mDevice->constructAndAddMapper<T>(EVENTHUB_ID, mFakePolicy->getReaderConfiguration(),
+                                                 args...);
+    }
+
     void setDisplayInfoAndReconfigure(int32_t displayId, int32_t width, int32_t height,
                                       ui::Rotation orientation, const std::string& uniqueId,
                                       std::optional<uint8_t> physicalPort,
diff --git a/services/inputflinger/tests/InputReader_test.cpp b/services/inputflinger/tests/InputReader_test.cpp
index 568d4e8..5645f4c 100644
--- a/services/inputflinger/tests/InputReader_test.cpp
+++ b/services/inputflinger/tests/InputReader_test.cpp
@@ -5082,7 +5082,7 @@
 TEST_F(SingleTouchInputMapperTest, GetSources_WhenDeviceTypeIsNotSpecifiedAndNotACursor_ReturnsPointer) {
     prepareButtons();
     prepareAxes(POSITION);
-    SingleTouchInputMapper& mapper = addMapperAndConfigure<SingleTouchInputMapper>();
+    SingleTouchInputMapper& mapper = constructAndAddMapper<SingleTouchInputMapper>();
 
     ASSERT_EQ(AINPUT_SOURCE_MOUSE, mapper.getSources());
 }
@@ -5091,7 +5091,7 @@
     prepareButtons();
     prepareAxes(POSITION);
     addConfigurationProperty("touch.deviceType", "touchScreen");
-    SingleTouchInputMapper& mapper = addMapperAndConfigure<SingleTouchInputMapper>();
+    SingleTouchInputMapper& mapper = constructAndAddMapper<SingleTouchInputMapper>();
 
     ASSERT_EQ(AINPUT_SOURCE_TOUCHSCREEN, mapper.getSources());
 }
@@ -5102,7 +5102,7 @@
     prepareButtons();
     prepareAxes(POSITION);
     prepareVirtualKeys();
-    SingleTouchInputMapper& mapper = addMapperAndConfigure<SingleTouchInputMapper>();
+    SingleTouchInputMapper& mapper = constructAndAddMapper<SingleTouchInputMapper>();
 
     // Unknown key.
     ASSERT_EQ(AKEY_STATE_UNKNOWN, mapper.getKeyCodeState(AINPUT_SOURCE_ANY, AKEYCODE_A));
@@ -5130,7 +5130,7 @@
     prepareButtons();
     prepareAxes(POSITION);
     prepareVirtualKeys();
-    SingleTouchInputMapper& mapper = addMapperAndConfigure<SingleTouchInputMapper>();
+    SingleTouchInputMapper& mapper = constructAndAddMapper<SingleTouchInputMapper>();
 
     // Unknown key.
     ASSERT_EQ(AKEY_STATE_UNKNOWN, mapper.getScanCodeState(AINPUT_SOURCE_ANY, KEY_A));
@@ -5158,7 +5158,7 @@
     prepareButtons();
     prepareAxes(POSITION);
     prepareVirtualKeys();
-    SingleTouchInputMapper& mapper = addMapperAndConfigure<SingleTouchInputMapper>();
+    SingleTouchInputMapper& mapper = constructAndAddMapper<SingleTouchInputMapper>();
 
     uint8_t flags[2] = { 0, 0 };
     ASSERT_TRUE(
@@ -5173,7 +5173,7 @@
     prepareButtons();
     prepareAxes(POSITION);
     prepareVirtualKeys();
-    SingleTouchInputMapper& mapper = addMapperAndConfigure<SingleTouchInputMapper>();
+    SingleTouchInputMapper& mapper = constructAndAddMapper<SingleTouchInputMapper>();
 
     mReader->getContext()->setGlobalMetaState(AMETA_SHIFT_LEFT_ON | AMETA_SHIFT_ON);
 
@@ -5223,7 +5223,7 @@
     prepareButtons();
     prepareAxes(POSITION);
     prepareVirtualKeys();
-    SingleTouchInputMapper& mapper = addMapperAndConfigure<SingleTouchInputMapper>();
+    SingleTouchInputMapper& mapper = constructAndAddMapper<SingleTouchInputMapper>();
 
     mReader->getContext()->setGlobalMetaState(AMETA_SHIFT_LEFT_ON | AMETA_SHIFT_ON);
 
@@ -5344,7 +5344,7 @@
     prepareButtons();
     prepareAxes(POSITION);
     prepareVirtualKeys();
-    SingleTouchInputMapper& mapper = addMapperAndConfigure<SingleTouchInputMapper>();
+    SingleTouchInputMapper& mapper = constructAndAddMapper<SingleTouchInputMapper>();
 
     mReader->getContext()->setGlobalMetaState(AMETA_SHIFT_LEFT_ON | AMETA_SHIFT_ON);
 
@@ -5419,7 +5419,7 @@
     prepareButtons();
     prepareAxes(POSITION);
     prepareVirtualKeys();
-    SingleTouchInputMapper& mapper = addMapperAndConfigure<SingleTouchInputMapper>();
+    SingleTouchInputMapper& mapper = constructAndAddMapper<SingleTouchInputMapper>();
 
     mReader->getContext()->setGlobalMetaState(AMETA_SHIFT_LEFT_ON | AMETA_SHIFT_ON);
 
@@ -5515,7 +5515,7 @@
     prepareButtons();
     prepareAxes(POSITION);
     prepareVirtualKeys();
-    SingleTouchInputMapper& mapper = addMapperAndConfigure<SingleTouchInputMapper>();
+    SingleTouchInputMapper& mapper = constructAndAddMapper<SingleTouchInputMapper>();
 
     mReader->getContext()->setGlobalMetaState(AMETA_SHIFT_LEFT_ON | AMETA_SHIFT_ON);
 
@@ -5605,7 +5605,7 @@
     prepareAxes(POSITION);
     // InputReader works in the un-rotated coordinate space, so orientation-aware devices do not
     // need to be rotated. Touchscreens are orientation-aware by default.
-    SingleTouchInputMapper& mapper = addMapperAndConfigure<SingleTouchInputMapper>();
+    SingleTouchInputMapper& mapper = constructAndAddMapper<SingleTouchInputMapper>();
 
     NotifyMotionArgs args;
 
@@ -5630,7 +5630,7 @@
     // Since InputReader works in the un-rotated coordinate space, only devices that are not
     // orientation-aware are affected by display rotation.
     addConfigurationProperty("touch.orientationAware", "0");
-    SingleTouchInputMapper& mapper = addMapperAndConfigure<SingleTouchInputMapper>();
+    SingleTouchInputMapper& mapper = constructAndAddMapper<SingleTouchInputMapper>();
 
     NotifyMotionArgs args;
 
@@ -5699,7 +5699,7 @@
     addConfigurationProperty("touch.orientation", "ORIENTATION_0");
     clearViewports();
     prepareDisplay(ui::ROTATION_0);
-    auto& mapper = addMapperAndConfigure<SingleTouchInputMapper>();
+    auto& mapper = constructAndAddMapper<SingleTouchInputMapper>();
     NotifyMotionArgs args;
 
     // Orientation 0.
@@ -5723,7 +5723,7 @@
     addConfigurationProperty("touch.orientation", "ORIENTATION_90");
     clearViewports();
     prepareDisplay(ui::ROTATION_0);
-    auto& mapper = addMapperAndConfigure<SingleTouchInputMapper>();
+    auto& mapper = constructAndAddMapper<SingleTouchInputMapper>();
     NotifyMotionArgs args;
 
     // Orientation 90.
@@ -5747,7 +5747,7 @@
     addConfigurationProperty("touch.orientation", "ORIENTATION_180");
     clearViewports();
     prepareDisplay(ui::ROTATION_0);
-    auto& mapper = addMapperAndConfigure<SingleTouchInputMapper>();
+    auto& mapper = constructAndAddMapper<SingleTouchInputMapper>();
     NotifyMotionArgs args;
 
     // Orientation 180.
@@ -5771,7 +5771,7 @@
     addConfigurationProperty("touch.orientation", "ORIENTATION_270");
     clearViewports();
     prepareDisplay(ui::ROTATION_0);
-    auto& mapper = addMapperAndConfigure<SingleTouchInputMapper>();
+    auto& mapper = constructAndAddMapper<SingleTouchInputMapper>();
     NotifyMotionArgs args;
 
     // Orientation 270.
@@ -5795,7 +5795,7 @@
     // orientation-aware are affected by display rotation.
     addConfigurationProperty("touch.orientationAware", "0");
     addConfigurationProperty("touch.orientation", "ORIENTATION_90");
-    auto& mapper = addMapperAndConfigure<SingleTouchInputMapper>();
+    auto& mapper = constructAndAddMapper<SingleTouchInputMapper>();
 
     NotifyMotionArgs args;
 
@@ -5862,7 +5862,7 @@
     prepareAxes(POSITION);
     addConfigurationProperty("touch.orientationAware", "1");
     prepareDisplay(ui::ROTATION_0);
-    auto& mapper = addMapperAndConfigure<SingleTouchInputMapper>();
+    auto& mapper = constructAndAddMapper<SingleTouchInputMapper>();
 
     // Set a physical frame in the display viewport.
     auto viewport = mFakePolicy->getDisplayViewportByType(ViewportType::INTERNAL);
@@ -5916,7 +5916,7 @@
     prepareDisplay(ui::ROTATION_0);
     prepareButtons();
     prepareAxes(POSITION | PRESSURE | TOOL | DISTANCE | TILT);
-    SingleTouchInputMapper& mapper = addMapperAndConfigure<SingleTouchInputMapper>();
+    SingleTouchInputMapper& mapper = constructAndAddMapper<SingleTouchInputMapper>();
 
     // These calculations are based on the input device calibration documentation.
     int32_t rawX = 100;
@@ -5961,7 +5961,7 @@
     prepareLocationCalibration();
     prepareButtons();
     prepareAxes(POSITION);
-    SingleTouchInputMapper& mapper = addMapperAndConfigure<SingleTouchInputMapper>();
+    SingleTouchInputMapper& mapper = constructAndAddMapper<SingleTouchInputMapper>();
 
     int32_t rawX = 100;
     int32_t rawY = 200;
@@ -5983,7 +5983,7 @@
     prepareDisplay(ui::ROTATION_0);
     prepareButtons();
     prepareAxes(POSITION);
-    SingleTouchInputMapper& mapper = addMapperAndConfigure<SingleTouchInputMapper>();
+    SingleTouchInputMapper& mapper = constructAndAddMapper<SingleTouchInputMapper>();
 
     NotifyMotionArgs motionArgs;
     NotifyKeyArgs keyArgs;
@@ -6226,7 +6226,7 @@
     prepareDisplay(ui::ROTATION_0);
     prepareButtons();
     prepareAxes(POSITION);
-    SingleTouchInputMapper& mapper = addMapperAndConfigure<SingleTouchInputMapper>();
+    SingleTouchInputMapper& mapper = constructAndAddMapper<SingleTouchInputMapper>();
 
     NotifyMotionArgs motionArgs;
 
@@ -6362,7 +6362,7 @@
     prepareButtons();
     prepareAxes(POSITION);
     mFakeEventHub->addKey(EVENTHUB_ID, BTN_TOOL_FINGER, 0, AKEYCODE_UNKNOWN, 0);
-    SingleTouchInputMapper& mapper = addMapperAndConfigure<SingleTouchInputMapper>();
+    SingleTouchInputMapper& mapper = constructAndAddMapper<SingleTouchInputMapper>();
 
     NotifyMotionArgs motionArgs;
 
@@ -6433,7 +6433,7 @@
     prepareDisplay(ui::ROTATION_0);
     prepareButtons();
     prepareAxes(POSITION | PRESSURE);
-    SingleTouchInputMapper& mapper = addMapperAndConfigure<SingleTouchInputMapper>();
+    SingleTouchInputMapper& mapper = constructAndAddMapper<SingleTouchInputMapper>();
 
     NotifyMotionArgs motionArgs;
 
@@ -6504,7 +6504,7 @@
     prepareDisplay(ui::ROTATION_0);
     prepareButtons();
     prepareAxes(POSITION | PRESSURE);
-    SingleTouchInputMapper& mapper = addMapperAndConfigure<SingleTouchInputMapper>();
+    SingleTouchInputMapper& mapper = constructAndAddMapper<SingleTouchInputMapper>();
 
     // Touch down.
     processDown(mapper, 100, 200);
@@ -6526,7 +6526,7 @@
     prepareDisplay(ui::ROTATION_0);
     prepareButtons();
     prepareAxes(POSITION | PRESSURE);
-    SingleTouchInputMapper& mapper = addMapperAndConfigure<SingleTouchInputMapper>();
+    SingleTouchInputMapper& mapper = constructAndAddMapper<SingleTouchInputMapper>();
 
     // Set the initial state for the touch pointer.
     mFakeEventHub->setAbsoluteAxisValue(EVENTHUB_ID, ABS_X, 100);
@@ -6554,7 +6554,7 @@
     prepareDisplay(ui::ROTATION_0);
     prepareButtons();
     prepareAxes(POSITION);
-    SingleTouchInputMapper& mapper = addMapperAndConfigure<SingleTouchInputMapper>();
+    SingleTouchInputMapper& mapper = constructAndAddMapper<SingleTouchInputMapper>();
     NotifyMotionArgs motionArgs;
 
     // Down.
@@ -6582,7 +6582,7 @@
     prepareDisplay(ui::ROTATION_0);
     prepareButtons();
     prepareAxes(POSITION);
-    SingleTouchInputMapper& mapper = addMapperAndConfigure<SingleTouchInputMapper>();
+    SingleTouchInputMapper& mapper = constructAndAddMapper<SingleTouchInputMapper>();
     ASSERT_NO_FATAL_FAILURE(mFakeListener->assertNotifyDeviceResetWasCalled());
     NotifyMotionArgs motionArgs;
 
@@ -6642,7 +6642,7 @@
     prepareDisplay(ui::ROTATION_0);
     prepareButtons();
     prepareAxes(POSITION);
-    SingleTouchInputMapper& mapper = addMapperAndConfigure<SingleTouchInputMapper>();
+    SingleTouchInputMapper& mapper = constructAndAddMapper<SingleTouchInputMapper>();
     ASSERT_NO_FATAL_FAILURE(mFakeListener->assertNotifyDeviceResetWasCalled());
 
     // Press a stylus button.
@@ -6683,7 +6683,7 @@
 
     mFakePolicy->setStylusButtonMotionEventsEnabled(false);
 
-    SingleTouchInputMapper& mapper = addMapperAndConfigure<SingleTouchInputMapper>();
+    SingleTouchInputMapper& mapper = constructAndAddMapper<SingleTouchInputMapper>();
     ASSERT_NO_FATAL_FAILURE(mFakeListener->assertNotifyDeviceResetWasCalled());
 
     // Press a stylus button.
@@ -6720,7 +6720,7 @@
     prepareDisplay(ui::ROTATION_0);
     prepareButtons();
     prepareAxes(POSITION);
-    SingleTouchInputMapper& mapper = addMapperAndConfigure<SingleTouchInputMapper>();
+    SingleTouchInputMapper& mapper = constructAndAddMapper<SingleTouchInputMapper>();
     ASSERT_NO_FATAL_FAILURE(mFakeListener->assertNotifyDeviceResetWasCalled());
 
     ASSERT_EQ(AINPUT_SOURCE_TOUCH_NAVIGATION, mapper.getSources());
@@ -6736,7 +6736,7 @@
     mFakeEventHub->addKey(EVENTHUB_ID, BTN_TOOL_PEN, 0, AKEYCODE_UNKNOWN, 0);
     mFakePolicy->setPointerController(fakePointerController);
     mFakePolicy->setStylusPointerIconEnabled(true);
-    SingleTouchInputMapper& mapper = addMapperAndConfigure<SingleTouchInputMapper>();
+    SingleTouchInputMapper& mapper = constructAndAddMapper<SingleTouchInputMapper>();
 
     processKey(mapper, BTN_TOOL_PEN, 1);
     processMove(mapper, 100, 200);
@@ -6760,7 +6760,7 @@
     mFakeEventHub->addKey(EVENTHUB_ID, BTN_TOOL_PEN, 0, AKEYCODE_UNKNOWN, 0);
     mFakePolicy->setPointerController(fakePointerController);
     mFakePolicy->setStylusPointerIconEnabled(false);
-    SingleTouchInputMapper& mapper = addMapperAndConfigure<SingleTouchInputMapper>();
+    SingleTouchInputMapper& mapper = constructAndAddMapper<SingleTouchInputMapper>();
 
     processKey(mapper, BTN_TOOL_PEN, 1);
     processMove(mapper, 100, 200);
@@ -6778,7 +6778,7 @@
     prepareDisplay(ui::ROTATION_0);
     prepareButtons();
     prepareAxes(POSITION);
-    SingleTouchInputMapper& mapper = addMapperAndConfigure<SingleTouchInputMapper>();
+    SingleTouchInputMapper& mapper = constructAndAddMapper<SingleTouchInputMapper>();
 
     // Ensure that the device is created as a touchscreen, not touch navigation.
     ASSERT_EQ(AINPUT_SOURCE_TOUCHSCREEN, mapper.getSources());
@@ -6812,7 +6812,7 @@
     mFakePolicy->updateViewport(*viewport);
     configureDevice(InputReaderConfiguration::Change::DISPLAY_INFO);
 
-    SingleTouchInputMapper& mapper = addMapperAndConfigure<SingleTouchInputMapper>();
+    SingleTouchInputMapper& mapper = constructAndAddMapper<SingleTouchInputMapper>();
 
     // Hovering inside the physical frame produces events.
     processKey(mapper, BTN_TOOL_PEN, 1);
@@ -6918,7 +6918,7 @@
 
     prepareButtons();
     prepareAxes(POSITION);
-    SingleTouchInputMapper& mapper = addMapperAndConfigure<SingleTouchInputMapper>();
+    SingleTouchInputMapper& mapper = constructAndAddMapper<SingleTouchInputMapper>();
 
     NotifyMotionArgs motionArgs;
 
@@ -6953,7 +6953,7 @@
 
     prepareButtons();
     prepareAxes(POSITION);
-    SingleTouchInputMapper& mapper = addMapperAndConfigure<SingleTouchInputMapper>();
+    SingleTouchInputMapper& mapper = constructAndAddMapper<SingleTouchInputMapper>();
 
     NotifyMotionArgs motionArgs;
 
@@ -7082,7 +7082,7 @@
     addConfigurationProperty("touch.orientation", ftl::enum_string(touchscreenOrientation).c_str());
     prepareDisplay(ui::ROTATION_0);
 
-    SingleTouchInputMapper& mapper = addMapperAndConfigure<SingleTouchInputMapper>();
+    SingleTouchInputMapper& mapper = constructAndAddMapper<SingleTouchInputMapper>();
 
     // If the touchscreen is installed in a rotated orientation relative to the display (i.e. in
     // orientations of either 90 or 270) this means the display's natural resolution will be
@@ -7134,7 +7134,7 @@
     addConfigurationProperty("touch.deviceType", "touchScreen");
     prepareDisplay(displayRotation);
 
-    SingleTouchInputMapper& mapper = addMapperAndConfigure<SingleTouchInputMapper>();
+    SingleTouchInputMapper& mapper = constructAndAddMapper<SingleTouchInputMapper>();
 
     const auto& expectedPoints = kMappedCorners.at(displayRotation);
 
@@ -7172,7 +7172,7 @@
     addConfigurationProperty("touch.deviceType", "touchScreen");
     addConfigurationProperty("touch.orientation", "ORIENTATION_270");
 
-    SingleTouchInputMapper& mapper = addMapperAndConfigure<SingleTouchInputMapper>();
+    SingleTouchInputMapper& mapper = constructAndAddMapper<SingleTouchInputMapper>();
 
     // Ori 270, so width and height swapped
     const Rect physicalFrame{0, 0, DISPLAY_HEIGHT, DISPLAY_WIDTH};
@@ -7208,7 +7208,7 @@
     prepareDisplay(displayRotation);
 
     __attribute__((unused)) SingleTouchInputMapper& mapper =
-            addMapperAndConfigure<SingleTouchInputMapper>();
+            constructAndAddMapper<SingleTouchInputMapper>();
 
     const InputDeviceInfo deviceInfo = mDevice->getDeviceInfo();
     // MotionRanges use display pixels as their units
@@ -7253,7 +7253,7 @@
         prepareDisplay(ui::ROTATION_0);
         prepareButtons();
         prepareAxes(POSITION);
-        auto& mapper = addMapperAndConfigure<SingleTouchInputMapper>();
+        auto& mapper = constructAndAddMapper<SingleTouchInputMapper>();
 
         mStylusState.when = ARBITRARY_TIME;
         mStylusState.pressure = 0.f;
@@ -7742,7 +7742,7 @@
     prepareDisplay(ui::ROTATION_0);
     prepareAxes(POSITION);
     prepareVirtualKeys();
-    MultiTouchInputMapper& mapper = addMapperAndConfigure<MultiTouchInputMapper>();
+    MultiTouchInputMapper& mapper = constructAndAddMapper<MultiTouchInputMapper>();
 
     mReader->getContext()->setGlobalMetaState(AMETA_SHIFT_LEFT_ON | AMETA_SHIFT_ON);
 
@@ -8026,7 +8026,7 @@
     mFakeEventHub->addAbsoluteAxis(EVENTHUB_ID, ABS_MT_WIDTH_MINOR, RAW_TOOL_MIN, RAW_TOOL_MAX,
                                    /*flat*/ 0, /*flat*/ 0, /*resolution*/ 15);
 
-    MultiTouchInputMapper& mapper = addMapperAndConfigure<MultiTouchInputMapper>();
+    MultiTouchInputMapper& mapper = constructAndAddMapper<MultiTouchInputMapper>();
 
     // X and Y axes
     assertAxisResolution(mapper, AMOTION_EVENT_AXIS_X, 10 / X_PRECISION);
@@ -8050,7 +8050,7 @@
 
     // We do not add ABS_MT_TOUCH_MAJOR / MINOR or ABS_MT_WIDTH_MAJOR / MINOR axes
 
-    MultiTouchInputMapper& mapper = addMapperAndConfigure<MultiTouchInputMapper>();
+    MultiTouchInputMapper& mapper = constructAndAddMapper<MultiTouchInputMapper>();
 
     // Touch major and minor
     assertAxisNotPresent(mapper, AMOTION_EVENT_AXIS_TOUCH_MAJOR);
@@ -8065,7 +8065,7 @@
     prepareDisplay(ui::ROTATION_0);
     prepareAxes(POSITION | ID);
     prepareVirtualKeys();
-    MultiTouchInputMapper& mapper = addMapperAndConfigure<MultiTouchInputMapper>();
+    MultiTouchInputMapper& mapper = constructAndAddMapper<MultiTouchInputMapper>();
 
     mReader->getContext()->setGlobalMetaState(AMETA_SHIFT_LEFT_ON | AMETA_SHIFT_ON);
 
@@ -8236,7 +8236,7 @@
     prepareDisplay(ui::ROTATION_0);
     prepareAxes(POSITION | ID | SLOT);
     prepareVirtualKeys();
-    MultiTouchInputMapper& mapper = addMapperAndConfigure<MultiTouchInputMapper>();
+    MultiTouchInputMapper& mapper = constructAndAddMapper<MultiTouchInputMapper>();
 
     mReader->getContext()->setGlobalMetaState(AMETA_SHIFT_LEFT_ON | AMETA_SHIFT_ON);
 
@@ -8401,7 +8401,7 @@
     addConfigurationProperty("touch.deviceType", "touchScreen");
     prepareDisplay(ui::ROTATION_0);
     prepareAxes(POSITION | TOUCH | TOOL | PRESSURE | ORIENTATION | ID | MINOR | DISTANCE);
-    MultiTouchInputMapper& mapper = addMapperAndConfigure<MultiTouchInputMapper>();
+    MultiTouchInputMapper& mapper = constructAndAddMapper<MultiTouchInputMapper>();
 
     // These calculations are based on the input device calibration documentation.
     int32_t rawX = 100;
@@ -8451,7 +8451,7 @@
     prepareDisplay(ui::ROTATION_0);
     prepareAxes(POSITION | TOUCH | TOOL | MINOR);
     addConfigurationProperty("touch.size.calibration", "geometric");
-    MultiTouchInputMapper& mapper = addMapperAndConfigure<MultiTouchInputMapper>();
+    MultiTouchInputMapper& mapper = constructAndAddMapper<MultiTouchInputMapper>();
 
     // These calculations are based on the input device calibration documentation.
     int32_t rawX = 100;
@@ -8491,7 +8491,7 @@
     addConfigurationProperty("touch.size.scale", "10");
     addConfigurationProperty("touch.size.bias", "160");
     addConfigurationProperty("touch.size.isSummed", "1");
-    MultiTouchInputMapper& mapper = addMapperAndConfigure<MultiTouchInputMapper>();
+    MultiTouchInputMapper& mapper = constructAndAddMapper<MultiTouchInputMapper>();
 
     // These calculations are based on the input device calibration documentation.
     // Note: We only provide a single common touch/tool value because the device is assumed
@@ -8541,7 +8541,7 @@
     addConfigurationProperty("touch.size.calibration", "area");
     addConfigurationProperty("touch.size.scale", "43");
     addConfigurationProperty("touch.size.bias", "3");
-    MultiTouchInputMapper& mapper = addMapperAndConfigure<MultiTouchInputMapper>();
+    MultiTouchInputMapper& mapper = constructAndAddMapper<MultiTouchInputMapper>();
 
     // These calculations are based on the input device calibration documentation.
     int32_t rawX = 100;
@@ -8573,7 +8573,7 @@
     prepareAxes(POSITION | PRESSURE);
     addConfigurationProperty("touch.pressure.calibration", "amplitude");
     addConfigurationProperty("touch.pressure.scale", "0.01");
-    MultiTouchInputMapper& mapper = addMapperAndConfigure<MultiTouchInputMapper>();
+    MultiTouchInputMapper& mapper = constructAndAddMapper<MultiTouchInputMapper>();
 
     InputDeviceInfo info;
     mapper.populateDeviceInfo(info);
@@ -8605,7 +8605,7 @@
     addConfigurationProperty("touch.deviceType", "touchScreen");
     prepareDisplay(ui::ROTATION_0);
     prepareAxes(POSITION | ID | SLOT);
-    MultiTouchInputMapper& mapper = addMapperAndConfigure<MultiTouchInputMapper>();
+    MultiTouchInputMapper& mapper = constructAndAddMapper<MultiTouchInputMapper>();
 
     NotifyMotionArgs motionArgs;
     NotifyKeyArgs keyArgs;
@@ -8848,7 +8848,7 @@
     addConfigurationProperty("touch.deviceType", "touchScreen");
     prepareDisplay(ui::ROTATION_0);
     prepareAxes(POSITION | ID | SLOT);
-    MultiTouchInputMapper& mapper = addMapperAndConfigure<MultiTouchInputMapper>();
+    MultiTouchInputMapper& mapper = constructAndAddMapper<MultiTouchInputMapper>();
 
     mFakeEventHub->addKey(EVENTHUB_ID, BTN_A, 0, AKEYCODE_STYLUS_BUTTON_PRIMARY, 0);
     mFakeEventHub->addKey(EVENTHUB_ID, 0, 0xabcd, AKEYCODE_STYLUS_BUTTON_SECONDARY, 0);
@@ -8905,7 +8905,7 @@
     addConfigurationProperty("touch.deviceType", "touchScreen");
     prepareDisplay(ui::ROTATION_0);
     prepareAxes(POSITION | ID | SLOT | TOOL_TYPE);
-    MultiTouchInputMapper& mapper = addMapperAndConfigure<MultiTouchInputMapper>();
+    MultiTouchInputMapper& mapper = constructAndAddMapper<MultiTouchInputMapper>();
 
     NotifyMotionArgs motionArgs;
 
@@ -9056,7 +9056,7 @@
     prepareDisplay(ui::ROTATION_0);
     prepareAxes(POSITION | ID | SLOT);
     mFakeEventHub->addKey(EVENTHUB_ID, BTN_TOUCH, 0, AKEYCODE_UNKNOWN, 0);
-    MultiTouchInputMapper& mapper = addMapperAndConfigure<MultiTouchInputMapper>();
+    MultiTouchInputMapper& mapper = constructAndAddMapper<MultiTouchInputMapper>();
 
     NotifyMotionArgs motionArgs;
 
@@ -9126,7 +9126,7 @@
     addConfigurationProperty("touch.deviceType", "touchScreen");
     prepareDisplay(ui::ROTATION_0);
     prepareAxes(POSITION | ID | SLOT | PRESSURE);
-    MultiTouchInputMapper& mapper = addMapperAndConfigure<MultiTouchInputMapper>();
+    MultiTouchInputMapper& mapper = constructAndAddMapper<MultiTouchInputMapper>();
 
     NotifyMotionArgs motionArgs;
 
@@ -9207,7 +9207,7 @@
 
     addConfigurationProperty("touch.deviceType", "touchScreen");
     prepareAxes(POSITION);
-    MultiTouchInputMapper& mapper = addMapperAndConfigure<MultiTouchInputMapper>();
+    MultiTouchInputMapper& mapper = constructAndAddMapper<MultiTouchInputMapper>();
 
     mFakePolicy->addInputPortAssociation(DEVICE_LOCATION, hdmi1);
     mFakePolicy->addInputPortAssociation(usb2, hdmi2);
@@ -9237,7 +9237,7 @@
 TEST_F(MultiTouchInputMapperTest, Configure_AssignsDisplayUniqueId) {
     addConfigurationProperty("touch.deviceType", "touchScreen");
     prepareAxes(POSITION);
-    MultiTouchInputMapper& mapper = addMapperAndConfigure<MultiTouchInputMapper>();
+    MultiTouchInputMapper& mapper = constructAndAddMapper<MultiTouchInputMapper>();
 
     mFakePolicy->addInputUniqueIdAssociation(DEVICE_LOCATION, VIRTUAL_DISPLAY_UNIQUE_ID);
 
@@ -9266,7 +9266,7 @@
 
     prepareDisplay(ui::ROTATION_0);
     prepareAxes(POSITION);
-    MultiTouchInputMapper& mapper = addMapperAndConfigure<MultiTouchInputMapper>();
+    MultiTouchInputMapper& mapper = constructAndAddMapper<MultiTouchInputMapper>();
 
     // Check source is mouse that would obtain the PointerController.
     ASSERT_EQ(AINPUT_SOURCE_MOUSE, mapper.getSources());
@@ -9286,7 +9286,7 @@
 TEST_F(MultiTouchInputMapperTest, Process_SendsReadTime) {
     addConfigurationProperty("touch.deviceType", "touchScreen");
     prepareAxes(POSITION);
-    MultiTouchInputMapper& mapper = addMapperAndConfigure<MultiTouchInputMapper>();
+    MultiTouchInputMapper& mapper = constructAndAddMapper<MultiTouchInputMapper>();
 
     prepareDisplay(ui::ROTATION_0);
     process(mapper, 10, /*readTime=*/11, EV_ABS, ABS_MT_TRACKING_ID, 1);
@@ -9317,7 +9317,7 @@
                                     /*isActive=*/false, UNIQUE_ID, NO_PORT, ViewportType::INTERNAL);
     configureDevice(InputReaderConfiguration::Change::DISPLAY_INFO);
     prepareAxes(POSITION);
-    MultiTouchInputMapper& mapper = addMapperAndConfigure<MultiTouchInputMapper>();
+    MultiTouchInputMapper& mapper = constructAndAddMapper<MultiTouchInputMapper>();
 
     NotifyMotionArgs motionArgs;
     processPosition(mapper, 100, 100);
@@ -9337,7 +9337,7 @@
                                     /*isActive=*/false, UNIQUE_ID, NO_PORT, ViewportType::INTERNAL);
     configureDevice(InputReaderConfiguration::Change::DISPLAY_INFO);
     prepareAxes(POSITION);
-    MultiTouchInputMapper& mapper = addMapperAndConfigure<MultiTouchInputMapper>();
+    MultiTouchInputMapper& mapper = constructAndAddMapper<MultiTouchInputMapper>();
 
     NotifyMotionArgs motionArgs;
     processPosition(mapper, 100, 100);
@@ -9359,7 +9359,7 @@
 
     configureDevice(InputReaderConfiguration::Change::DISPLAY_INFO);
     prepareAxes(POSITION);
-    MultiTouchInputMapper& mapper = addMapperAndConfigure<MultiTouchInputMapper>();
+    MultiTouchInputMapper& mapper = constructAndAddMapper<MultiTouchInputMapper>();
 
     // Finger down
     int32_t x = 100, y = 100;
@@ -9402,7 +9402,7 @@
     // Setup the first touch screen device.
     prepareAxes(POSITION | ID | SLOT);
     addConfigurationProperty("touch.deviceType", "touchScreen");
-    MultiTouchInputMapper& mapper = addMapperAndConfigure<MultiTouchInputMapper>();
+    MultiTouchInputMapper& mapper = constructAndAddMapper<MultiTouchInputMapper>();
 
     // Create the second touch screen device, and enable multi fingers.
     const std::string USB2 = "USB2";
@@ -9426,9 +9426,9 @@
                                             String8("touchScreen"));
 
     // Setup the second touch screen device.
-    MultiTouchInputMapper& mapper2 =
-            device2->addMapper<MultiTouchInputMapper>(SECOND_EVENTHUB_ID,
-                                                      mFakePolicy->getReaderConfiguration());
+    device2->addEmptyEventHubDevice(SECOND_EVENTHUB_ID);
+    MultiTouchInputMapper& mapper2 = device2->constructAndAddMapper<
+            MultiTouchInputMapper>(SECOND_EVENTHUB_ID, mFakePolicy->getReaderConfiguration());
     std::list<NotifyArgs> unused =
             device2->configure(ARBITRARY_TIME, mFakePolicy->getReaderConfiguration(),
                                /*changes=*/{});
@@ -9493,7 +9493,7 @@
     prepareAxes(POSITION);
     addConfigurationProperty("touch.deviceType", "touchScreen");
     prepareDisplay(ui::ROTATION_0);
-    MultiTouchInputMapper& mapper = addMapperAndConfigure<MultiTouchInputMapper>();
+    MultiTouchInputMapper& mapper = constructAndAddMapper<MultiTouchInputMapper>();
 
     NotifyMotionArgs motionArgs;
     // Unrotated video frame
@@ -9517,7 +9517,7 @@
 TEST_F(MultiTouchInputMapperTest, VideoFrames_AreNotRotated) {
     prepareAxes(POSITION);
     addConfigurationProperty("touch.deviceType", "touchScreen");
-    MultiTouchInputMapper& mapper = addMapperAndConfigure<MultiTouchInputMapper>();
+    MultiTouchInputMapper& mapper = constructAndAddMapper<MultiTouchInputMapper>();
     // Unrotated video frame
     TouchVideoFrame frame(3, 2, {1, 2, 3, 4, 5, 6}, {1, 2});
     NotifyMotionArgs motionArgs;
@@ -9542,7 +9542,7 @@
     // Since InputReader works in the un-rotated coordinate space, only devices that are not
     // orientation-aware are affected by display rotation.
     addConfigurationProperty("touch.orientationAware", "0");
-    MultiTouchInputMapper& mapper = addMapperAndConfigure<MultiTouchInputMapper>();
+    MultiTouchInputMapper& mapper = constructAndAddMapper<MultiTouchInputMapper>();
     // Unrotated video frame
     TouchVideoFrame frame(3, 2, {1, 2, 3, 4, 5, 6}, {1, 2});
     NotifyMotionArgs motionArgs;
@@ -9573,7 +9573,7 @@
 TEST_F(MultiTouchInputMapperTest, VideoFrames_MultipleFramesAreNotRotated) {
     prepareAxes(POSITION);
     addConfigurationProperty("touch.deviceType", "touchScreen");
-    MultiTouchInputMapper& mapper = addMapperAndConfigure<MultiTouchInputMapper>();
+    MultiTouchInputMapper& mapper = constructAndAddMapper<MultiTouchInputMapper>();
     // Unrotated video frames. There's no rule that they must all have the same dimensions,
     // so mix these.
     TouchVideoFrame frame1(3, 2, {1, 2, 3, 4, 5, 6}, {1, 2});
@@ -9596,7 +9596,7 @@
     // Since InputReader works in the un-rotated coordinate space, only devices that are not
     // orientation-aware are affected by display rotation.
     addConfigurationProperty("touch.orientationAware", "0");
-    MultiTouchInputMapper& mapper = addMapperAndConfigure<MultiTouchInputMapper>();
+    MultiTouchInputMapper& mapper = constructAndAddMapper<MultiTouchInputMapper>();
     // Unrotated video frames. There's no rule that they must all have the same dimensions,
     // so mix these.
     TouchVideoFrame frame1(3, 2, {1, 2, 3, 4, 5, 6}, {1, 2});
@@ -9633,7 +9633,7 @@
 
     addConfigurationProperty("touch.deviceType", "touchScreen");
     prepareAxes(POSITION);
-    MultiTouchInputMapper& mapper = addMapperAndConfigure<MultiTouchInputMapper>();
+    MultiTouchInputMapper& mapper = constructAndAddMapper<MultiTouchInputMapper>();
 
     ASSERT_EQ(mDevice->isEnabled(), false);
 
@@ -9654,7 +9654,7 @@
     addConfigurationProperty("touch.deviceType", "touchScreen");
     prepareDisplay(ui::ROTATION_0);
     prepareAxes(POSITION | ID | SLOT | TOOL_TYPE);
-    MultiTouchInputMapper& mapper = addMapperAndConfigure<MultiTouchInputMapper>();
+    MultiTouchInputMapper& mapper = constructAndAddMapper<MultiTouchInputMapper>();
 
     NotifyMotionArgs motionArgs;
 
@@ -9699,7 +9699,7 @@
     addConfigurationProperty("touch.deviceType", "touchScreen");
     prepareDisplay(ui::ROTATION_0);
     prepareAxes(POSITION | ID | SLOT | TOOL_TYPE);
-    MultiTouchInputMapper& mapper = addMapperAndConfigure<MultiTouchInputMapper>();
+    MultiTouchInputMapper& mapper = constructAndAddMapper<MultiTouchInputMapper>();
 
     NotifyMotionArgs motionArgs;
 
@@ -9747,7 +9747,7 @@
     addConfigurationProperty("touch.deviceType", "touchScreen");
     prepareDisplay(ui::ROTATION_0);
     prepareAxes(POSITION | ID | SLOT | TOOL_TYPE);
-    MultiTouchInputMapper& mapper = addMapperAndConfigure<MultiTouchInputMapper>();
+    MultiTouchInputMapper& mapper = constructAndAddMapper<MultiTouchInputMapper>();
 
     NotifyMotionArgs motionArgs;
 
@@ -9822,7 +9822,7 @@
     addConfigurationProperty("touch.deviceType", "touchScreen");
     prepareDisplay(ui::ROTATION_0);
     prepareAxes(POSITION | ID | SLOT | TOOL_TYPE);
-    MultiTouchInputMapper& mapper = addMapperAndConfigure<MultiTouchInputMapper>();
+    MultiTouchInputMapper& mapper = constructAndAddMapper<MultiTouchInputMapper>();
 
     NotifyMotionArgs motionArgs;
 
@@ -9920,7 +9920,7 @@
     addConfigurationProperty("touch.deviceType", "touchScreen");
     prepareDisplay(ui::ROTATION_0);
     prepareAxes(POSITION | ID | SLOT | TOOL_TYPE);
-    MultiTouchInputMapper& mapper = addMapperAndConfigure<MultiTouchInputMapper>();
+    MultiTouchInputMapper& mapper = constructAndAddMapper<MultiTouchInputMapper>();
 
     NotifyMotionArgs motionArgs;
 
@@ -9992,7 +9992,7 @@
     addConfigurationProperty("touch.deviceType", "touchScreen");
     prepareDisplay(ui::ROTATION_0);
     prepareAxes(POSITION | ID | SLOT | PRESSURE);
-    MultiTouchInputMapper& mapper = addMapperAndConfigure<MultiTouchInputMapper>();
+    MultiTouchInputMapper& mapper = constructAndAddMapper<MultiTouchInputMapper>();
 
     NotifyMotionArgs motionArgs;
 
@@ -10049,7 +10049,7 @@
     addConfigurationProperty("touch.deviceType", "touchScreen");
     prepareDisplay(ui::ROTATION_0);
     prepareAxes(POSITION | ID | SLOT | PRESSURE);
-    MultiTouchInputMapper& mapper = addMapperAndConfigure<MultiTouchInputMapper>();
+    MultiTouchInputMapper& mapper = constructAndAddMapper<MultiTouchInputMapper>();
 
     // First finger down.
     processId(mapper, FIRST_TRACKING_ID);
@@ -10090,7 +10090,7 @@
     addConfigurationProperty("touch.deviceType", "touchScreen");
     prepareDisplay(ui::ROTATION_0);
     prepareAxes(POSITION | ID | SLOT | PRESSURE);
-    MultiTouchInputMapper& mapper = addMapperAndConfigure<MultiTouchInputMapper>();
+    MultiTouchInputMapper& mapper = constructAndAddMapper<MultiTouchInputMapper>();
 
     // First finger touches down and releases.
     processId(mapper, FIRST_TRACKING_ID);
@@ -10118,7 +10118,7 @@
     addConfigurationProperty("touch.deviceType", "touchScreen");
     prepareDisplay(ui::ROTATION_0);
     prepareAxes(POSITION | ID | SLOT | PRESSURE | TOOL_TYPE);
-    MultiTouchInputMapper& mapper = addMapperAndConfigure<MultiTouchInputMapper>();
+    MultiTouchInputMapper& mapper = constructAndAddMapper<MultiTouchInputMapper>();
     ASSERT_NO_FATAL_FAILURE(mFakeListener->assertNotifyDeviceResetWasCalled());
 
     // Even if the device supports reporting the ABS_MT_TOOL_TYPE axis, which could give it the
@@ -10173,7 +10173,7 @@
             std::make_shared<FakePointerController>();
     mFakePolicy->setPointerController(fakePointerController);
     mFakePolicy->setStylusPointerIconEnabled(true);
-    MultiTouchInputMapper& mapper = addMapperAndConfigure<MultiTouchInputMapper>();
+    MultiTouchInputMapper& mapper = constructAndAddMapper<MultiTouchInputMapper>();
 
     processId(mapper, FIRST_TRACKING_ID);
     processPressure(mapper, RAW_PRESSURE_MIN);
@@ -10200,7 +10200,7 @@
             std::make_shared<FakePointerController>();
     mFakePolicy->setPointerController(fakePointerController);
     mFakePolicy->setStylusPointerIconEnabled(false);
-    MultiTouchInputMapper& mapper = addMapperAndConfigure<MultiTouchInputMapper>();
+    MultiTouchInputMapper& mapper = constructAndAddMapper<MultiTouchInputMapper>();
 
     processId(mapper, FIRST_TRACKING_ID);
     processPressure(mapper, RAW_PRESSURE_MIN);
@@ -10228,7 +10228,7 @@
     prepareAxes(POSITION);
     addConfigurationProperty("touch.deviceType", "touchScreen");
     prepareDisplay(ui::ROTATION_0);
-    MultiTouchInputMapper& mapper = addMapperAndConfigure<MultiTouchInputMapper>();
+    MultiTouchInputMapper& mapper = constructAndAddMapper<MultiTouchInputMapper>();
 
     ASSERT_EQ(AINPUT_SOURCE_TOUCHSCREEN, mapper.getSources());
 
@@ -10263,7 +10263,7 @@
     mFakeEventHub->addKey(EVENTHUB_ID, BTN_TOUCH, 0, AKEYCODE_UNKNOWN, 0);
     mFakePolicy->setPointerCapture(true);
     mFakePolicy->setPointerController(fakePointerController);
-    MultiTouchInputMapper& mapper = addMapperAndConfigure<MultiTouchInputMapper>();
+    MultiTouchInputMapper& mapper = constructAndAddMapper<MultiTouchInputMapper>();
 
     // captured touchpad should be a touchpad source
     NotifyDeviceResetArgs resetArgs;
@@ -10411,7 +10411,7 @@
     mFakeEventHub->addKey(EVENTHUB_ID, BTN_LEFT, 0, AKEYCODE_UNKNOWN, 0);
     mFakeEventHub->addKey(EVENTHUB_ID, BTN_TOUCH, 0, AKEYCODE_UNKNOWN, 0);
     mFakePolicy->setPointerController(fakePointerController);
-    MultiTouchInputMapper& mapper = addMapperAndConfigure<MultiTouchInputMapper>();
+    MultiTouchInputMapper& mapper = constructAndAddMapper<MultiTouchInputMapper>();
     // run uncaptured pointer tests - pushes out generic events
     // FINGER 0 DOWN
     processId(mapper, 3);
@@ -10472,7 +10472,7 @@
     mFakeEventHub->addKey(EVENTHUB_ID, BTN_LEFT, 0, AKEYCODE_UNKNOWN, 0);
     mFakePolicy->setPointerController(fakePointerController);
     mFakePolicy->setPointerCapture(false);
-    MultiTouchInputMapper& mapper = addMapperAndConfigure<MultiTouchInputMapper>();
+    MultiTouchInputMapper& mapper = constructAndAddMapper<MultiTouchInputMapper>();
 
     // uncaptured touchpad should be a pointer device
     ASSERT_EQ(AINPUT_SOURCE_MOUSE, mapper.getSources());
@@ -10496,7 +10496,7 @@
     addConfigurationProperty("touch.deviceType", "touchScreen");
     prepareDisplay(ui::ROTATION_0);
     prepareAxes(POSITION | ID | SLOT | PRESSURE);
-    MultiTouchInputMapper& mapper = addMapperAndConfigure<MultiTouchInputMapper>();
+    MultiTouchInputMapper& mapper = constructAndAddMapper<MultiTouchInputMapper>();
 
     nsecs_t kernelEventTime = ARBITRARY_TIME;
     nsecs_t expectedEventTime = ARBITRARY_TIME;
@@ -10583,7 +10583,7 @@
     // which is greater than fraction of the diagnal length of the touchpad (349).
     // Thus, MaxSwipWidth is 750.
     preparePointerMode(/*xResolution=*/25, /*yResolution=*/25);
-    MultiTouchInputMapper& mapper = addMapperAndConfigure<MultiTouchInputMapper>();
+    MultiTouchInputMapper& mapper = constructAndAddMapper<MultiTouchInputMapper>();
     NotifyMotionArgs motionArgs;
 
     // Two fingers down at once.
@@ -10643,7 +10643,7 @@
     // which is greater than fraction of the diagnal length of the touchpad (349).
     // Thus, MaxSwipWidth is the fraction of the diagnal length, 349.
     preparePointerMode(/*xResolution=*/5, /*yResolution=*/5);
-    MultiTouchInputMapper& mapper = addMapperAndConfigure<MultiTouchInputMapper>();
+    MultiTouchInputMapper& mapper = constructAndAddMapper<MultiTouchInputMapper>();
     NotifyMotionArgs motionArgs;
 
     // Two fingers down at once.
@@ -10699,7 +10699,7 @@
  */
 TEST_F(MultiTouchPointerModeTest, PointerGestureMaxSwipeWidthFreeform) {
     preparePointerMode(/*xResolution=*/25, /*yResolution=*/25);
-    MultiTouchInputMapper& mapper = addMapperAndConfigure<MultiTouchInputMapper>();
+    MultiTouchInputMapper& mapper = constructAndAddMapper<MultiTouchInputMapper>();
 
     NotifyMotionArgs motionArgs;
 
@@ -10794,7 +10794,7 @@
 
 TEST_F(MultiTouchPointerModeTest, TwoFingerSwipeOffsets) {
     preparePointerMode(/*xResolution=*/25, /*yResolution=*/25);
-    MultiTouchInputMapper& mapper = addMapperAndConfigure<MultiTouchInputMapper>();
+    MultiTouchInputMapper& mapper = constructAndAddMapper<MultiTouchInputMapper>();
     NotifyMotionArgs motionArgs;
 
     // Place two fingers down.
@@ -10841,7 +10841,7 @@
 TEST_F(MultiTouchPointerModeTest, WhenViewportActiveStatusChanged_PointerGestureIsReset) {
     preparePointerMode(/*xResolution=*/25, /*yResolution=*/25);
     mFakeEventHub->addKey(EVENTHUB_ID, BTN_TOOL_PEN, 0, AKEYCODE_UNKNOWN, 0);
-    MultiTouchInputMapper& mapper = addMapperAndConfigure<MultiTouchInputMapper>();
+    MultiTouchInputMapper& mapper = constructAndAddMapper<MultiTouchInputMapper>();
     ASSERT_NO_FATAL_FAILURE(mFakeListener->assertNotifyDeviceResetWasCalled());
 
     // Start a stylus gesture.
diff --git a/services/inputflinger/tests/fuzzers/FuzzContainer.h b/services/inputflinger/tests/fuzzers/FuzzContainer.h
index 84ac0fd..b992928 100644
--- a/services/inputflinger/tests/fuzzers/FuzzContainer.h
+++ b/services/inputflinger/tests/fuzzers/FuzzContainer.h
@@ -75,9 +75,12 @@
 
     template <class T, typename... Args>
     T& getMapper(Args... args) {
-        T& mapper = mFuzzDevice->addMapper<T>(mFdp->ConsumeIntegral<int32_t>(), args...);
+        int32_t eventhubId = mFdp->ConsumeIntegral<int32_t>();
+        // ensure a device entry exists for this eventHubId
+        mFuzzDevice->addEmptyEventHubDevice(eventhubId);
         configureDevice();
-        return mapper;
+
+        return mFuzzDevice->template constructAndAddMapper<T>(eventhubId, args...);
     }
 };