使用車用監控計時器協助偵錯 VHAL。車輛監控計時器
不健康的過程監控程序
,程序必須向車輛監控計時器註冊。時間
車輛監控計時器會終止健康狀態不良的過程
和其他應用程式無回應一樣,對 data/anr
的程序
(ANR) 傾印這麼做會讓偵錯程序更為完善。
本文說明廠商 HAL 和服務如何透過 監控車輛監控計時器
供應商 HAL
供應商 HAL 通常會針對 hwbinder
使用執行緒集區。不過
汽車監控器客戶與汽車監控程式 Daemon 通訊
binder
,與 hwbinder
不同。因此
「binder
」的另一個執行緒集區正在使用中。
在 makefile 中指定車輛監控計時器輔助鍵
- 在
shared_libs
中加入carwatchdog_aidl_interface-ndk_platform
:Android.bp
:cc_defaults { name: "vhal_v2_0_defaults", shared_libs: [ "libbinder_ndk", "libhidlbase", "liblog", "libutils", "android.hardware.automotive.vehicle@2.0", "carwatchdog_aidl_interface-ndk_platform", ], cflags: [ "-Wall", "-Wextra", "-Werror", ], }
新增 SELinux 政策
-
允許
system_server
終止 HAL。 如果沒有system_server.te
,請建立一個。它非常 建議您為每部裝置新增 SELinux 政策。 -
允許供應商 HAL 使用繫結器 (
binder_use
巨集) 並將供應商 HAL 新增至carwatchdog
客戶網域 (carwatchdog_client_domain
巨集)。 請查看下方systemserver.te
和vehicle_default.te
的程式碼:system_server.te
# Allow system_server to kill vehicle HAL allow system_server hal_vehicle_server:process sigkill;
hal_vehicle_default.te
# Configuration for register VHAL to car watchdog carwatchdog_client_domain(hal_vehicle_default) binder_use(hal_vehicle_default)
沿用 BnCarWatchdogClient
-
在
checkIfAlive
執行健康狀態檢查。舉例來說,您可以將訊息發布至 執行緒迴圈處理常式如果健康狀態良好,請呼叫ICarWatchdog::tellClientAlive
。 請查看下方WatchogClient.h
和WatchogClient.cpp
的程式碼:WatchogClient.h
class WatchdogClient : public aidl::android::automotive::watchdog::BnCarWatchdogClient { public: explicit WatchdogClient(const ::android::sp<::android::Looper>& handlerLooper, VehicleHalManager* vhalManager);
ndk::ScopedAStatus checkIfAlive(int32_t sessionId, aidl::android::automotive::watchdog::TimeoutLength timeout) override; ndk::ScopedAStatus prepareProcessTermination() override; };WatchogClient.cpp
ndk::ScopedAStatus WatchdogClient::checkIfAlive(int32_t sessionId, TimeoutLength /*timeout*/) { // Implement or call your health check logic here return ndk::ScopedAStatus::ok(); }
啟動繫結器執行緒,並註冊用戶端
- 建立用於繫結器通訊的執行緒集區。如果廠商 HAL 使用 hwbinder 您必須建立另一個執行緒集區,以執行車輛監控的繫結器通訊)。
-
使用名稱搜尋 Daemon,並呼叫
ICarWatchdog::registerClient
。 車輛監控計時器 Daemon 介面名稱為android.automotive.watchdog.ICarWatchdog/default
。 -
根據服務反應,從以下三種逾時類型中選取其中一種
,然後在呼叫
ICarWatchdog::registerClient
:- 重大(3 秒)
- 中等(5 秒)
- 一般(10 秒)
VehicleService.cpp
和WatchogClient.cpp
的程式碼:VehicleService.cpp (車輛服務)
int main(int /* argc */, char* /* argv */ []) { // Set up thread pool for hwbinder configureRpcThreadpool(4, false /* callerWillJoin */); ALOGI("Registering as service..."); status_t status = service->registerAsService(); if (status != OK) { ALOGE("Unable to register vehicle service (%d)", status); return 1; } // Setup a binder thread pool to be a car watchdog client. ABinderProcess_setThreadPoolMaxThreadCount(1); ABinderProcess_startThreadPool(); sp<Looper> looper(Looper::prepare(0 /* opts */)); std::shared_ptr<WatchdogClient> watchdogClient = ndk::SharedRefBase::make<WatchdogClient>(looper, service.get()); // The current health check is done in the main thread, so it falls short of capturing the real // situation. Checking through HAL binder thread should be considered. if (!watchdogClient->initialize()) { ALOGE("Failed to initialize car watchdog client"); return 1; } ALOGI("Ready"); while (true) { looper->pollAll(-1 /* timeoutMillis */); } return 1; }
WatchogClient.cpp
bool WatchdogClient::initialize() { ndk::SpAIBinder binder(AServiceManager_getService("android.automotive.watchdog.ICarWatchdog/default")); if (binder.get() == nullptr) { ALOGE("Failed to get carwatchdog daemon"); return false; } std::shared_ptr<ICarWatchdog> server = ICarWatchdog::fromBinder(binder); if (server == nullptr) { ALOGE("Failed to connect to carwatchdog daemon"); return false; } mWatchdogServer = server; binder = this->asBinder(); if (binder.get() == nullptr) { ALOGE("Failed to get car watchdog client binder object"); return false; } std::shared_ptr<ICarWatchdogClient> client = ICarWatchdogClient::fromBinder(binder); if (client == nullptr) { ALOGE("Failed to get ICarWatchdogClient from binder"); return false; } mTestClient = client; mWatchdogServer->registerClient(client, TimeoutLength::TIMEOUT_NORMAL); ALOGI("Successfully registered the client to car watchdog server"); return true; }
供應商服務 (原生)
指定車輛監控狗的輔助 makefile
- 在
shared_libs
中加入carwatchdog_aidl_interface-ndk_platform
。Android.bp
cc_binary { name: "sample_native_client", srcs: [ "src/*.cpp" ], shared_libs: [ "carwatchdog_aidl_interface-ndk_platform", "libbinder_ndk", ], vendor: true, }
新增 SELinux 政策
- 如要新增 SELinux 政策,請允許供應商服務網域使用繫結器
(
binder_use
巨集),並將供應商服務網域加進carwatchdog
用戶端網域 (carwatchdog_client_domain
巨集)。 請查看下方sample_client.te
和file_contexts
的程式碼:sample_client.te
type sample_client, domain; type sample_client_exec, exec_type, file_type, vendor_file_type; carwatchdog_client_domain(sample_client) init_daemon_domain(sample_client) binder_use(sample_client)
file_contexts
/vendor/bin/sample_native_client u:object_r:sample_client_exec:s0
沿用 BnCarWatchdogClient
- 在
checkIfAlive
中執行健康狀態檢查。您可以選擇發布至 執行緒迴圈處理常式如果健康狀態良好,請呼叫ICarWatchdog::tellClientAlive
。 請查看下方SampleNativeClient.h
和SampleNativeClient.cpp
的程式碼:SampleNativeClient.h
class SampleNativeClient : public BnCarWatchdogClient { public: ndk::ScopedAStatus checkIfAlive(int32_t sessionId, TimeoutLength timeout) override; ndk::ScopedAStatus prepareProcessTermination() override; void initialize(); private: void respondToDaemon(); private: ::android::sp<::android::Looper> mHandlerLooper; std::shared_ptr<ICarWatchdog> mWatchdogServer; std::shared_ptr<ICarWatchdogClient> mClient; int32_t mSessionId; };
SampleNativeClient.cpp
ndk::ScopedAStatus WatchdogClient::checkIfAlive(int32_t sessionId, TimeoutLength timeout) { mHandlerLooper->removeMessages(mMessageHandler, WHAT_CHECK_ALIVE); mSessionId = sessionId; mHandlerLooper->sendMessage(mMessageHandler, Message(WHAT_CHECK_ALIVE)); return ndk::ScopedAStatus::ok(); } // WHAT_CHECK_ALIVE triggers respondToDaemon from thread handler void WatchdogClient::respondToDaemon() { // your health checking method here ndk::ScopedAStatus status = mWatchdogServer->tellClientAlive(mClient, mSessionId); }
啟動繫結器執行緒,並註冊用戶端
車輛監控計時器 Daemon 介面名稱為
android.automotive.watchdog.ICarWatchdog/default
。
- 使用名稱搜尋 Daemon,並呼叫
ICarWatchdog::registerClient
。 請查看下方main.cpp
和SampleNativeClient.cpp
的程式碼:main.cpp
int main(int argc, char** argv) { sp<Looper> looper(Looper::prepare(/*opts=*/0)); ABinderProcess_setThreadPoolMaxThreadCount(1); ABinderProcess_startThreadPool(); std::shared_ptr<SampleNativeClient> client = ndk::SharedRefBase::make<SampleNatvieClient>(looper); // The client is registered in initialize() client->initialize(); ... }
SampleNativeClient.cpp
void SampleNativeClient::initialize() { ndk::SpAIBinder binder(AServiceManager_getService( "android.automotive.watchdog.ICarWatchdog/default")); std::shared_ptr<ICarWatchdog> server = ICarWatchdog::fromBinder(binder); mWatchdogServer = server; ndk::SpAIBinder binder = this->asBinder(); std::shared_ptr<ICarWatchdogClient> client = ICarWatchdogClient::fromBinder(binder) mClient = client; server->registerClient(client, TimeoutLength::TIMEOUT_NORMAL); }
供應商服務 (Android)
沿用 CarWatchdogClientCallback 實作用戶端
- 按照下列方式編輯新檔案:
private final CarWatchdogClientCallback mClientCallback = new CarWatchdogClientCallback() { @Override public boolean onCheckHealthStatus(int sessionId, int timeout) { // Your health check logic here // Returning true implies the client is healthy // If false is returned, the client should call // CarWatchdogManager.tellClientAlive after health check is // completed } @Override public void onPrepareProcessTermination() {} };
註冊用戶端
- 呼叫
CarWatchdogManager.registerClient()
:private void startClient() { CarWatchdogManager manager = (CarWatchdogManager) car.getCarManager( Car.CAR_WATCHDOG_SERVICE); // Choose a proper executor according to your health check method ExecutorService executor = Executors.newFixedThreadPool(1); manager.registerClient(executor, mClientCallback, CarWatchdogManager.TIMEOUT_NORMAL); }
取消註冊用戶端
- 在服務完成後呼叫
CarWatchdogManager.unregisterClient()
:private void finishClient() { CarWatchdogManager manager = (CarWatchdogManager) car.getCarManager( Car.CAR_WATCHDOG_SERVICE); manager.unregisterClient(mClientCallback); }
偵測車輛監控計時器終止的程序
車輛監控計時器傾印/技能程序 (廠商 HAL、供應商原生服務
Android 服務供應商 Android 服務)。
系統停滯或沒有回應透過檢查 logcat 偵測此類傾印。車輛
監控計時器會輸出 carwatchdog killed process_name (pid:process_id)
記錄
程序遭傾印或終止時。因此:
$ adb logcat -s CarServiceHelper | fgrep "carwatchdog killed"
擷取相關記錄。舉例來說,如果 KitchenSink 應用程式 (車子監控計時器) 用戶端) 卡住,所以下列這一行會寫入記錄中:
05-01 09:50:19.683 578 5777 W CarServiceHelper: carwatchdog killed com.google.android.car.kitchensink (pid: 5574)
如要判斷 KitchenSink 應用程式停止運作的原因或位置,請使用程序傾印
就和使用活動 ANR 情況的情況一樣,儲存資源為 /data/anr
。
$ adb root $ adb shell grep -Hn "pid process_pid" /data/anr/*
下列範例輸出內容僅適用於 KitchenSink 應用程式:
$ adb shell su root grep -Hn "pid 5574" /data/anr/*. /data/anr/anr_2020-05-01-09-50-18-290:3:----- pid 5574 at 2020-05-01 09:50:18 ----- /data/anr/anr_2020-05-01-09-50-18-290:285:----- Waiting Channels: pid 5574 at 2020-05-01 09:50:18 -----
找出傾印檔案 (例如 /data/anr/anr_2020-05-01-09-50-18-290
)
),然後開始分析。