Dynamic sensor manager -- implementation of basic sensor daemon

Library to handle dynamic sensor connection. There are two way to use
this: as hal extension or standalone hal module.

In hal extension mode: add libdynamic_sensor_ext in dependency of hal,
instantiate DynamicSensorManager with appropriate parameters. Then
for all sensor requests, if the handle is owned by dynamic sensor
manager, forward the request.

In standalone mode, add sensor.dynamic_sensor_hal into device make
file. Usually, this also means multihal is necessary. Add
sensor.dynamic_sensor_hal into multihal configuration file.

A dummy sensor module is included for testing.

Test: tested with cts dynamics sensor related test and demo app.
      also verified sensor basic operation with sensor logger.

Change-Id: I16612935fc21b06c173aca875401ece37c6bde01

1 files changed, 81 insertions, 0 deletions

diff --git a/modules/sensors/dynamic_sensor/ConnectionDetector.h b/modules/sensors/dynamic_sensor/ConnectionDetector.h
new file mode 100644
index 00000000..712d832f
--- /dev/null
+++ b/modules/sensors/dynamic_sensor/ConnectionDetector.h
@@ -0,0 +1,81 @@
+/*
+ * Copyright (C) 2017 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 ANDROID_SENSORHAL_EXT_CONNECTION_DETECTOR_H
+#define ANDROID_SENSORHAL_EXT_CONNECTION_DETECTOR_H
+
+#include "BaseDynamicSensorDaemon.h"
+#include <utils/Thread.h>
+
+#include <regex>
+
+#include <poll.h>
+
+namespace android {
+namespace SensorHalExt {
+
+// Abstraction of connection detector: an entity that calls
+// BaseDynamicSensorDaemon::onConnectionChange() when necessary.
+class ConnectionDetector : virtual public RefBase {
+public:
+    ConnectionDetector(BaseDynamicSensorDaemon *d) : mDaemon(d) { }
+    virtual ~ConnectionDetector() = default;
+protected:
+    BaseDynamicSensorDaemon* mDaemon;
+};
+
+// Open a socket that listen to localhost:port and notify sensor daemon of connection and
+// disconnection event when socket is connected or disconnected, respectively. Only one concurrent
+// client is accepted.
+class SocketConnectionDetector : public ConnectionDetector, public Thread {
+public:
+    SocketConnectionDetector(BaseDynamicSensorDaemon *d, int port);
+    virtual ~SocketConnectionDetector();
+private:
+    // implement virtual of Thread
+    virtual bool threadLoop();
+    int waitForConnection();
+    static void waitForDisconnection(int connFd);
+
+    int mListenFd;
+    std::string mDevice;
+};
+
+// Detect file change under path and notify sensor daemon of connection and disconnection event when
+// file is created in or removed from the directory, respectively.
+class FileConnectionDetector : public ConnectionDetector, public Thread {
+public:
+    FileConnectionDetector(
+            BaseDynamicSensorDaemon *d, const std::string &path, const std::string &regex);
+    virtual ~FileConnectionDetector();
+private:
+    // implement virtual of Thread
+    virtual bool threadLoop();
+
+    bool matches(const std::string &name) const;
+    void processExistingFiles() const;
+    std::string getFullName(const std::string name) const;
+
+    std::string mPath;
+    std::regex mRegex;
+    int mInotifyFd;
+    struct pollfd mPollFd;
+};
+
+} // namespace SensorHalExt
+} // namespace android
+
+#endif // ANDROID_SENSORHAL_EXT_DYNAMIC_SENSOR_DAEMON_H