Support native API to report sysfs nodes changes

When a sysfs node change is reported, check if any new
perpherals are added and if added, recreate input device.

Test: atest inputfliger_tests
Bug: 265057712
Change-Id: Ic6c0c00de9ae963f0651859bdbc57e45af7ccd07
diff --git a/services/inputflinger/reader/EventHub.cpp b/services/inputflinger/reader/EventHub.cpp
index e65f3af..ee8dde1 100644
--- a/services/inputflinger/reader/EventHub.cpp
+++ b/services/inputflinger/reader/EventHub.cpp
@@ -1531,6 +1531,20 @@
     return associatedDevice;
 }
 
+bool EventHub::AssociatedDevice::isChanged() const {
+    std::unordered_map<int32_t, RawBatteryInfo> newBatteryInfos =
+            readBatteryConfiguration(sysfsRootPath);
+    std::unordered_map<int32_t, RawLightInfo> newLightInfos =
+            readLightsConfiguration(sysfsRootPath);
+    std::optional<RawLayoutInfo> newLayoutInfo = readLayoutConfiguration(sysfsRootPath);
+
+    if (newBatteryInfos == batteryInfos && newLightInfos == lightInfos &&
+        newLayoutInfo == layoutInfo) {
+        return false;
+    }
+    return true;
+}
+
 void EventHub::vibrate(int32_t deviceId, const VibrationElement& element) {
     std::scoped_lock _l(mLock);
     Device* device = getDeviceLocked(deviceId);
@@ -2536,6 +2550,42 @@
     return device->disable();
 }
 
+// TODO(b/274755573): Shift to uevent handling on native side and remove this method
+// Currently using Java UEventObserver to trigger this which uses UEvent infrastructure that uses a
+// NETLINK socket to observe UEvents. We can create similar infrastructure on Eventhub side to
+// directly observe UEvents instead of triggering from Java side.
+void EventHub::sysfsNodeChanged(const std::string& sysfsNodePath) {
+    std::scoped_lock _l(mLock);
+
+    // Check in opening devices
+    for (auto it = mOpeningDevices.begin(); it != mOpeningDevices.end(); it++) {
+        std::unique_ptr<Device>& device = *it;
+        if (device->associatedDevice &&
+            sysfsNodePath.find(device->associatedDevice->sysfsRootPath.string()) !=
+                    std::string::npos &&
+            device->associatedDevice->isChanged()) {
+            it = mOpeningDevices.erase(it);
+            openDeviceLocked(device->path);
+        }
+    }
+
+    // Check in already added device
+    std::vector<Device*> devicesToReopen;
+    for (const auto& [id, device] : mDevices) {
+        if (device->associatedDevice &&
+            sysfsNodePath.find(device->associatedDevice->sysfsRootPath.string()) !=
+                    std::string::npos &&
+            device->associatedDevice->isChanged()) {
+            devicesToReopen.push_back(device.get());
+        }
+    }
+    for (const auto& device : devicesToReopen) {
+        closeDeviceLocked(*device);
+        openDeviceLocked(device->path);
+    }
+    devicesToReopen.clear();
+}
+
 void EventHub::createVirtualKeyboardLocked() {
     InputDeviceIdentifier identifier;
     identifier.name = "Virtual";
diff --git a/services/inputflinger/reader/InputReader.cpp b/services/inputflinger/reader/InputReader.cpp
index 9080cc1..81ac03b 100644
--- a/services/inputflinger/reader/InputReader.cpp
+++ b/services/inputflinger/reader/InputReader.cpp
@@ -928,6 +928,10 @@
     return *associatedDisplayId == displayId;
 }
 
+void InputReader::sysfsNodeChanged(const std::string& sysfsNodePath) {
+    mEventHub->sysfsNodeChanged(sysfsNodePath);
+}
+
 void InputReader::dump(std::string& dump) {
     std::scoped_lock _l(mLock);
 
diff --git a/services/inputflinger/reader/include/EventHub.h b/services/inputflinger/reader/include/EventHub.h
index 0b15efe..20612c7 100644
--- a/services/inputflinger/reader/include/EventHub.h
+++ b/services/inputflinger/reader/include/EventHub.h
@@ -388,6 +388,10 @@
 
     /* Disable an input device. Closes file descriptor to that device. */
     virtual status_t disableDevice(int32_t deviceId) = 0;
+
+    /* Sysfs node changed. Reopen the Eventhub device if any new Peripheral like Light, Battery,
+     * etc. is detected. */
+    virtual void sysfsNodeChanged(const std::string& sysfsNodePath) = 0;
 };
 
 template <std::size_t BITS>
@@ -567,6 +571,8 @@
 
     status_t disableDevice(int32_t deviceId) override final;
 
+    void sysfsNodeChanged(const std::string& sysfsNodePath) override final;
+
     ~EventHub() override;
 
 private:
@@ -578,6 +584,7 @@
         std::unordered_map<int32_t /*lightId*/, RawLightInfo> lightInfos;
         std::optional<RawLayoutInfo> layoutInfo;
 
+        bool isChanged() const;
         bool operator==(const AssociatedDevice&) const = default;
         bool operator!=(const AssociatedDevice&) const = default;
         std::string dump() const;
diff --git a/services/inputflinger/reader/include/InputReader.h b/services/inputflinger/reader/include/InputReader.h
index e9c989a..120e150 100644
--- a/services/inputflinger/reader/include/InputReader.h
+++ b/services/inputflinger/reader/include/InputReader.h
@@ -117,6 +117,8 @@
 
     std::optional<std::string> getBluetoothAddress(int32_t deviceId) const override;
 
+    void sysfsNodeChanged(const std::string& sysfsNodePath) override;
+
 protected:
     // These members are protected so they can be instrumented by test cases.
     virtual std::shared_ptr<InputDevice> createDeviceLocked(int32_t deviceId,