Add Stable AIDL version of EVS HAL

This CL add a new set of EVS APIs written in Stable AIDL with an empty
IEvsEnumerator implementation.

Bug: 170401743
Bug: 195672428
Bug: 202031799
Bug: 202669715
Test: m -j
Change-Id: I28ff4391ba51b72299ebfae801d21a8ab0e37917
diff --git a/automotive/evs/aidl/vts/FrameHandler.h b/automotive/evs/aidl/vts/FrameHandler.h
new file mode 100644
index 0000000..0b959ab
--- /dev/null
+++ b/automotive/evs/aidl/vts/FrameHandler.h
@@ -0,0 +1,105 @@
+/*
+ * Copyright (C) 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.
+ */
+
+#ifndef AUTOMOTIVE_EVS_VTS_FRAMEHANDLER_H
+#define AUTOMOTIVE_EVS_VTS_FRAMEHANDLER_H
+
+#include <aidl/android/hardware/automotive/evs/BnEvsCameraStream.h>
+#include <aidl/android/hardware/automotive/evs/EvsEventDesc.h>
+#include <aidl/android/hardware/automotive/evs/IEvsCamera.h>
+#include <aidl/android/hardware/automotive/evs/IEvsDisplay.h>
+
+#include <mutex>
+#include <queue>
+
+/*
+ * FrameHandler:
+ * This class can be used to receive camera imagery from an IEvsCamera implementation.  Given an
+ * IEvsDisplay instance at startup, it will forward the received imagery to the display,
+ * providing a trivial implementation of a rear vew camera type application.
+ * Note that the video frames are delivered on a background thread, while the control interface
+ * is actuated from the applications foreground thread.
+ */
+class FrameHandler : public ::aidl::android::hardware::automotive::evs::BnEvsCameraStream {
+  public:
+    enum BufferControlFlag {
+        eAutoReturn,
+        eNoAutoReturn,
+    };
+
+    FrameHandler(
+            const std::shared_ptr<::aidl::android::hardware::automotive::evs::IEvsCamera>& pCamera,
+            const ::aidl::android::hardware::automotive::evs::CameraDesc& cameraInfo,
+            const std::shared_ptr<::aidl::android::hardware::automotive::evs::IEvsDisplay>&
+                    pDisplay,
+            BufferControlFlag mode = eAutoReturn);
+    virtual ~FrameHandler() {
+        if (mCamera != nullptr) {
+            /* shutdown a camera explicitly */
+            shutdown();
+        }
+    }
+
+    void shutdown();
+    bool startStream();
+    void asyncStopStream();
+    void blockingStopStream();
+    bool returnHeldBuffer();
+    bool isRunning();
+    void waitForFrameCount(unsigned frameCount);
+    bool waitForEvent(const ::aidl::android::hardware::automotive::evs::EvsEventDesc& aTargetEvent,
+                      ::aidl::android::hardware::automotive::evs::EvsEventDesc& aReceivedEvent,
+                      bool ignorePayload = false);
+    void getFramesCounters(unsigned* received, unsigned* displayed);
+    void getFrameDimension(unsigned* width, unsigned* height);
+
+  private:
+    // Methods from ::aidl::android::hardware::automotive::evs::IEvsCameraStream follow.
+    ::ndk::ScopedAStatus deliverFrame(
+            const std::vector<::aidl::android::hardware::automotive::evs::BufferDesc>& buffer)
+            override;
+    ::ndk::ScopedAStatus notify(
+            const ::aidl::android::hardware::automotive::evs::EvsEventDesc& event) override;
+
+    // Local implementation details
+    bool copyBufferContents(
+            const ::aidl::android::hardware::automotive::evs::BufferDesc& tgtBuffer,
+            const ::aidl::android::hardware::automotive::evs::BufferDesc& srcBuffer);
+    const char* eventToString(const ::aidl::android::hardware::automotive::evs::EvsEventType aType);
+
+    std::shared_ptr<::aidl::android::hardware::automotive::evs::IEvsCamera> mCamera;
+    ::aidl::android::hardware::automotive::evs::CameraDesc mCameraInfo;
+    std::shared_ptr<::aidl::android::hardware::automotive::evs::IEvsDisplay> mDisplay;
+    BufferControlFlag mReturnMode;
+
+    // Since we get frames delivered to us asynchronously via the IEvsCameraStream interface,
+    // we need to protect all member variables that may be modified while we're streaming
+    // (ie: those below)
+    std::mutex mLock;
+    std::mutex mEventLock;
+    std::condition_variable mEventSignal;
+    std::condition_variable mFrameSignal;
+    std::queue<std::vector<::aidl::android::hardware::automotive::evs::BufferDesc>> mHeldBuffers;
+
+    bool mRunning = false;
+    unsigned mFramesReceived = 0;   // Simple counter -- rolls over eventually!
+    unsigned mFramesDisplayed = 0;  // Simple counter -- rolls over eventually!
+    unsigned mFrameWidth = 0;
+    unsigned mFrameHeight = 0;
+    ::aidl::android::hardware::automotive::evs::EvsEventDesc mLatestEventDesc;
+};
+
+#endif  // AUTOMOTIVE_EVS_VTS_FRAMEHANDLER_H