diff --git a/services/inputflinger/include/InputReaderBase.h b/services/inputflinger/include/InputReaderBase.h
index 573524e..ffd8bf2 100644
--- a/services/inputflinger/include/InputReaderBase.h
+++ b/services/inputflinger/include/InputReaderBase.h
@@ -78,7 +78,7 @@
      *
      * This method may be called on any thread (usually by the input manager).
      */
-    virtual void getInputDevices(std::vector<InputDeviceInfo>& outInputDevices) = 0;
+    virtual std::vector<InputDeviceInfo> getInputDevices() const = 0;
 
     /* Query current input state. */
     virtual int32_t getScanCodeState(int32_t deviceId, uint32_t sourceMask,
diff --git a/services/inputflinger/reader/InputReader.cpp b/services/inputflinger/reader/InputReader.cpp
index 7c96e54..2028b91 100644
--- a/services/inputflinger/reader/InputReader.cpp
+++ b/services/inputflinger/reader/InputReader.cpp
@@ -87,7 +87,6 @@
     int32_t oldGeneration;
     int32_t timeoutMillis;
     bool inputDevicesChanged = false;
-    std::vector<InputDeviceInfo> inputDevices;
     { // acquire lock
         AutoMutex _l(mLock);
 
@@ -128,13 +127,12 @@
 
         if (oldGeneration != mGeneration) {
             inputDevicesChanged = true;
-            getInputDevicesLocked(inputDevices);
         }
     } // release lock
 
     // Send out a message that the describes the changed input devices.
     if (inputDevicesChanged) {
-        mPolicy->notifyInputDevicesChanged(inputDevices);
+        mPolicy->notifyInputDevicesChanged(getInputDevicesLocked());
     }
 
     // Flush queued events out to the listener.
@@ -474,13 +472,14 @@
     return ++mGeneration;
 }
 
-void InputReader::getInputDevices(std::vector<InputDeviceInfo>& outInputDevices) {
+std::vector<InputDeviceInfo> InputReader::getInputDevices() const {
     AutoMutex _l(mLock);
-    getInputDevicesLocked(outInputDevices);
+    return getInputDevicesLocked();
 }
 
-void InputReader::getInputDevicesLocked(std::vector<InputDeviceInfo>& outInputDevices) {
-    outInputDevices.clear();
+std::vector<InputDeviceInfo> InputReader::getInputDevicesLocked() const {
+    std::vector<InputDeviceInfo> outInputDevices;
+    outInputDevices.reserve(mDeviceToEventHubIdsMap.size());
 
     for (const auto& [device, eventHubIds] : mDeviceToEventHubIdsMap) {
         if (!device->isIgnored()) {
@@ -489,6 +488,7 @@
             outInputDevices.push_back(info);
         }
     }
+    return outInputDevices;
 }
 
 int32_t InputReader::getKeyCodeState(int32_t deviceId, uint32_t sourceMask, int32_t keyCode) {
diff --git a/services/inputflinger/reader/include/InputReader.h b/services/inputflinger/reader/include/InputReader.h
index a902482..563018a 100644
--- a/services/inputflinger/reader/include/InputReader.h
+++ b/services/inputflinger/reader/include/InputReader.h
@@ -61,7 +61,7 @@
     status_t start() override;
     status_t stop() override;
 
-    void getInputDevices(std::vector<InputDeviceInfo>& outInputDevices) override;
+    std::vector<InputDeviceInfo> getInputDevices() const override;
 
     bool isInputDeviceEnabled(int32_t deviceId) override;
 
@@ -121,7 +121,7 @@
 private:
     std::unique_ptr<InputThread> mThread;
 
-    Mutex mLock;
+    mutable Mutex mLock;
 
     Condition mReaderIsAliveCondition;
 
@@ -181,7 +181,7 @@
     int32_t mNextInputDeviceId;
     int32_t nextInputDeviceIdLocked();
 
-    void getInputDevicesLocked(std::vector<InputDeviceInfo>& outInputDevices);
+    std::vector<InputDeviceInfo> getInputDevicesLocked() const;
 
     nsecs_t mDisableVirtualKeysTimeout;
     void disableVirtualKeysUntilLocked(nsecs_t time);
diff --git a/services/inputflinger/tests/InputReader_test.cpp b/services/inputflinger/tests/InputReader_test.cpp
index 54a36a9..b4d58f6 100644
--- a/services/inputflinger/tests/InputReader_test.cpp
+++ b/services/inputflinger/tests/InputReader_test.cpp
@@ -1330,22 +1330,27 @@
     }
 };
 
-TEST_F(InputReaderTest, GetInputDevices) {
+TEST_F(InputReaderTest, ReaderGetInputDevices) {
     ASSERT_NO_FATAL_FAILURE(addDevice(1, "keyboard", InputDeviceClass::KEYBOARD, nullptr));
     ASSERT_NO_FATAL_FAILURE(addDevice(2, "ignored", Flags<InputDeviceClass>(0),
                                       nullptr)); // no classes so device will be ignored
 
-    std::vector<InputDeviceInfo> inputDevices;
-    mReader->getInputDevices(inputDevices);
+    const std::vector<InputDeviceInfo> inputDevices = mReader->getInputDevices();
     ASSERT_EQ(1U, inputDevices.size());
     ASSERT_EQ(END_RESERVED_ID + 1, inputDevices[0].getId());
     ASSERT_STREQ("keyboard", inputDevices[0].getIdentifier().name.c_str());
     ASSERT_EQ(AINPUT_KEYBOARD_TYPE_NON_ALPHABETIC, inputDevices[0].getKeyboardType());
     ASSERT_EQ(AINPUT_SOURCE_KEYBOARD, inputDevices[0].getSources());
     ASSERT_EQ(size_t(0), inputDevices[0].getMotionRanges().size());
+}
+
+TEST_F(InputReaderTest, PolicyGetInputDevices) {
+    ASSERT_NO_FATAL_FAILURE(addDevice(1, "keyboard", InputDeviceClass::KEYBOARD, nullptr));
+    ASSERT_NO_FATAL_FAILURE(addDevice(2, "ignored", Flags<InputDeviceClass>(0),
+                                      nullptr)); // no classes so device will be ignored
 
     // Should also have received a notification describing the new input devices.
-    inputDevices = mFakePolicy->getInputDevices();
+    const std::vector<InputDeviceInfo>& inputDevices = mFakePolicy->getInputDevices();
     ASSERT_EQ(1U, inputDevices.size());
     ASSERT_EQ(END_RESERVED_ID + 1, inputDevices[0].getId());
     ASSERT_STREQ("keyboard", inputDevices[0].getIdentifier().name.c_str());
@@ -1372,9 +1377,7 @@
             addDevice(eventHubIds[1], "fake2", InputDeviceClass::KEYBOARD, nullptr));
 
     // Two devices will be merged to one input device as they have same identifier
-    std::vector<InputDeviceInfo> inputDevices;
-    mReader->getInputDevices(inputDevices);
-    ASSERT_EQ(1U, inputDevices.size());
+    ASSERT_EQ(1U, mReader->getInputDevices().size());
 }
 
 TEST_F(InputReaderTest, WhenEnabledChanges_SendsDeviceResetNotification) {
@@ -1815,20 +1818,17 @@
     ASSERT_EQ(initialNumDevices + 1, mFakePolicy->getInputDevices().size());
 
     // Find the test device by its name.
-    std::vector<InputDeviceInfo> inputDevices;
-    mReader->getInputDevices(inputDevices);
-    InputDeviceInfo* keyboardInfo = nullptr;
-    const char* keyboardName = keyboard->getName();
-    for (unsigned int i = 0; i < initialNumDevices + 1; i++) {
-        if (!strcmp(inputDevices[i].getIdentifier().name.c_str(), keyboardName)) {
-            keyboardInfo = &inputDevices[i];
-            break;
-        }
-    }
-    ASSERT_NE(keyboardInfo, nullptr);
-    ASSERT_EQ(AINPUT_KEYBOARD_TYPE_NON_ALPHABETIC, keyboardInfo->getKeyboardType());
-    ASSERT_EQ(AINPUT_SOURCE_KEYBOARD, keyboardInfo->getSources());
-    ASSERT_EQ(0U, keyboardInfo->getMotionRanges().size());
+    const std::vector<InputDeviceInfo> inputDevices = mReader->getInputDevices();
+    const auto& it =
+            std::find_if(inputDevices.begin(), inputDevices.end(),
+                         [&keyboard](const InputDeviceInfo& info) {
+                             return info.getIdentifier().name == keyboard->getName();
+                         });
+
+    ASSERT_NE(it, inputDevices.end());
+    ASSERT_EQ(AINPUT_KEYBOARD_TYPE_NON_ALPHABETIC, it->getKeyboardType());
+    ASSERT_EQ(AINPUT_SOURCE_KEYBOARD, it->getSources());
+    ASSERT_EQ(0U, it->getMotionRanges().size());
 
     keyboard.reset();
     ASSERT_NO_FATAL_FAILURE(mFakePolicy->assertInputDevicesChanged());