Start with async and HCI
Bug: 205758693
Test: unit tests
Change-Id: I16a8be44bce5f2d233582ab6db17c30d068fa9c0
diff --git a/bluetooth/async/async_fd_watcher.h b/bluetooth/async/async_fd_watcher.h
new file mode 100644
index 0000000..b50a7a0
--- /dev/null
+++ b/bluetooth/async/async_fd_watcher.h
@@ -0,0 +1,60 @@
+/*
+ * Copyright 2022 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.
+ */
+
+#pragma once
+
+#include <map>
+#include <mutex>
+#include <thread>
+
+namespace android::hardware::bluetooth::async {
+
+using ReadCallback = std::function<void(int)>;
+using TimeoutCallback = std::function<void(void)>;
+
+class AsyncFdWatcher {
+ public:
+ AsyncFdWatcher() = default;
+ ~AsyncFdWatcher();
+
+ int WatchFdForNonBlockingReads(int file_descriptor,
+ const ReadCallback& on_read_fd_ready_callback);
+ int ConfigureTimeout(const std::chrono::milliseconds timeout,
+ const TimeoutCallback& on_timeout_callback);
+ void StopWatchingFileDescriptors();
+
+ private:
+ AsyncFdWatcher(const AsyncFdWatcher&) = delete;
+ AsyncFdWatcher& operator=(const AsyncFdWatcher&) = delete;
+
+ int tryStartThread();
+ int stopThread();
+ int notifyThread();
+ void ThreadRoutine();
+
+ std::atomic_bool running_{false};
+ std::thread thread_;
+ std::mutex internal_mutex_;
+ std::mutex timeout_mutex_;
+
+ std::map<int, ReadCallback> watched_fds_;
+ int notification_listen_fd_;
+ int notification_write_fd_;
+ TimeoutCallback timeout_cb_;
+ std::chrono::milliseconds timeout_ms_;
+};
+
+} // namespace android::hardware::bluetooth::async