Make mediaserver listen to Codec2 services' deaths

Test: Kill media.extractor or mediaswcodec and observe logcat

Bug: 130071409

Change-Id: Ie785642da99dfe4ff13e78d878817dae3de9f34a
diff --git a/media/libmediaplayerservice/DeathNotifier.cpp b/media/libmediaplayerservice/DeathNotifier.cpp
new file mode 100644
index 0000000..d13bdf5
--- /dev/null
+++ b/media/libmediaplayerservice/DeathNotifier.cpp
@@ -0,0 +1,80 @@
+/*
+ * Copyright 2019 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.
+ */
+
+//#define LOG_NDEBUG 0
+#define LOG_TAG "MediaPlayerService-DeathNotifier"
+#include <android-base/logging.h>
+
+#include "DeathNotifier.h"
+
+namespace android {
+
+class DeathNotifier::DeathRecipient :
+        public IBinder::DeathRecipient,
+        public hardware::hidl_death_recipient {
+public:
+    using Notify = DeathNotifier::Notify;
+
+    DeathRecipient(Notify const& notify): mNotify{notify} {
+    }
+
+    virtual void binderDied(wp<IBinder> const&) override {
+        mNotify();
+    }
+
+    virtual void serviceDied(uint64_t, wp<HBase> const&) override {
+        mNotify();
+    }
+
+private:
+    Notify mNotify;
+};
+
+DeathNotifier::DeathNotifier(sp<IBinder> const& service, Notify const& notify)
+      : mService{std::in_place_index<1>, service},
+        mDeathRecipient{new DeathRecipient(notify)} {
+    service->linkToDeath(mDeathRecipient);
+}
+
+DeathNotifier::DeathNotifier(sp<HBase> const& service, Notify const& notify)
+      : mService{std::in_place_index<2>, service},
+        mDeathRecipient{new DeathRecipient(notify)} {
+    service->linkToDeath(mDeathRecipient, 0);
+}
+
+DeathNotifier::DeathNotifier(DeathNotifier&& other)
+      : mService{other.mService}, mDeathRecipient{other.mDeathRecipient} {
+    other.mService.emplace<0>();
+    other.mDeathRecipient = nullptr;
+}
+
+DeathNotifier::~DeathNotifier() {
+    switch (mService.index()) {
+    case 0:
+        break;
+    case 1:
+        std::get<1>(mService)->unlinkToDeath(mDeathRecipient);
+        break;
+    case 2:
+        std::get<2>(mService)->unlinkToDeath(mDeathRecipient);
+        break;
+    default:
+        CHECK(false) << "Corrupted service type during destruction.";
+    }
+}
+
+} // namespace android
+