| /** |
| * Copyright (c) 2021, The Android Open Source Project |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| #ifndef CPP_LIBSYSFSMONITOR_SRC_SYSFSMONITOR_H_ |
| #define CPP_LIBSYSFSMONITOR_SRC_SYSFSMONITOR_H_ |
| |
| #include <android-base/result.h> |
| #include <android-base/unique_fd.h> |
| #include <utils/RefBase.h> |
| |
| #include <functional> |
| #include <string> |
| #include <unordered_set> |
| |
| namespace android { |
| namespace automotive { |
| |
| using CallbackFunc = ::std::function<void(const std::vector<int32_t>&)>; |
| |
| /** |
| * SysfsMonitor monitors sysfs file changes and invokes the registered callback when there is a |
| * change at the sysfs files to monitor. |
| */ |
| class SysfsMonitor final : public RefBase { |
| public: |
| // Initializes SysfsMonitor instance. |
| android::base::Result<void> init(CallbackFunc callback); |
| // Releases resources used for monitoring. |
| android::base::Result<void> release(); |
| // Registers a sysfs file to monitor. |
| android::base::Result<void> registerFd(int32_t fd); |
| // Unregisters a sysfs file to monitor. |
| android::base::Result<void> unregisterFd(int32_t fd); |
| // Starts observing sysfs file changes. |
| android::base::Result<void> observe(); |
| |
| private: |
| android::base::unique_fd mEpollFd; |
| std::unordered_set<int32_t> mMonitoringFds; |
| CallbackFunc mCallback; |
| }; |
| |
| } // namespace automotive |
| } // namespace android |
| |
| #endif // CPP_LIBSYSFSMONITOR_SRC_SYSFSMONITOR_H_ |