Monitor crashes of audio hal service via linkToDeath
Hwbinder 'linkToDeath' mechanism is used to track abrupt
disappearance of server hal objects due to hal server crash.
Upon hal server crash, notifications can be sent to binder
clients if needed, then the audioserver crashes itself as the
current audio HAL design does not provide an easy way to restore
all the transient objects (devices, streams, effects) in their
pre-crash state.
Bug: 34158778
Test: In binderized mode, kill audio hal server
Change-Id: If9265711edc445984601fcb5c29d2c173a370762
diff --git a/media/libaudiohal/HalDeathHandlerHidl.cpp b/media/libaudiohal/HalDeathHandlerHidl.cpp
new file mode 100644
index 0000000..a742671
--- /dev/null
+++ b/media/libaudiohal/HalDeathHandlerHidl.cpp
@@ -0,0 +1,59 @@
+/*
+ * 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.
+ */
+
+#define LOG_TAG "HalDeathHandler"
+//#define LOG_NDEBUG 0
+
+#include <utils/Log.h>
+
+#include <media/audiohal/hidl/HalDeathHandler.h>
+
+namespace android {
+
+ANDROID_SINGLETON_STATIC_INSTANCE(HalDeathHandler);
+
+// static
+sp<HalDeathHandler> HalDeathHandler::getInstance() {
+ return &Singleton<HalDeathHandler>::getInstance();
+}
+
+HalDeathHandler::HalDeathHandler() : mSelf(this) {
+}
+
+HalDeathHandler::~HalDeathHandler() {
+}
+
+void HalDeathHandler::registerAtExitHandler(void* cookie, AtExitHandler handler) {
+ std::lock_guard<std::mutex> guard(mHandlersLock);
+ mHandlers.insert({cookie, handler});
+}
+
+void HalDeathHandler::unregisterAtExitHandler(void* cookie) {
+ std::lock_guard<std::mutex> guard(mHandlersLock);
+ mHandlers.erase(cookie);
+}
+
+void HalDeathHandler::serviceDied(uint64_t /*cookie*/, const wp<IBase>& /*who*/) {
+ // No matter which of the service objects has died,
+ // we need to run all the registered handlers and crash our process.
+ std::lock_guard<std::mutex> guard(mHandlersLock);
+ for (const auto& handler : mHandlers) {
+ handler.second();
+ }
+ LOG_ALWAYS_FATAL("HAL server crashed, need to restart");
+}
+
+} // namespace android