| /* |
| * Copyright (C) 2018 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. |
| */ |
| |
| package com.android.server; |
| |
| import android.util.Log; |
| import android.util.LogWriter; |
| import android.util.Slog; |
| |
| import com.android.internal.annotations.VisibleForTesting; |
| import com.android.server.Watchdog.HandlerChecker; |
| |
| import dalvik.system.AnnotatedStackTraceElement; |
| import dalvik.system.VMStack; |
| |
| import java.io.PrintWriter; |
| import java.util.List; |
| |
| /** |
| * Class to give diagnostic messages for Watchdogs. |
| */ |
| class WatchdogDiagnostics { |
| private static String getBlockedOnString(Object blockedOn) { |
| return String.format("- waiting to lock <0x%08x> (a %s)", |
| System.identityHashCode(blockedOn), blockedOn.getClass().getName()); |
| } |
| |
| private static String getLockedString(Object heldLock) { |
| return String.format("- locked <0x%08x> (a %s)", System.identityHashCode(heldLock), |
| heldLock.getClass().getName()); |
| } |
| |
| /** |
| * Print the annotated stack for the given thread. If the annotated stack cannot be retrieved, |
| * returns false. |
| */ |
| @VisibleForTesting |
| public static boolean printAnnotatedStack(Thread thread, PrintWriter out) { |
| AnnotatedStackTraceElement stack[] = VMStack.getAnnotatedThreadStackTrace(thread); |
| if (stack == null) { |
| return false; |
| } |
| out.println(thread.getName() + " annotated stack trace:"); |
| for (AnnotatedStackTraceElement element : stack) { |
| out.println(" at " + element.getStackTraceElement()); |
| if (element.getBlockedOn() != null) { |
| out.println(" " + getBlockedOnString(element.getBlockedOn())); |
| } |
| if (element.getHeldLocks() != null) { |
| for (Object held : element.getHeldLocks()) { |
| out.println(" " + getLockedString(held)); |
| } |
| } |
| } |
| return true; |
| } |
| |
| public static void diagnoseCheckers(final List<HandlerChecker> blockedCheckers) { |
| PrintWriter out = new PrintWriter(new LogWriter(Log.WARN, Watchdog.TAG, Log.LOG_ID_SYSTEM), |
| true); |
| for (int i=0; i<blockedCheckers.size(); i++) { |
| Thread blockedThread = blockedCheckers.get(i).getThread(); |
| if (printAnnotatedStack(blockedThread, out)) { |
| continue; |
| } |
| |
| // Fall back to "regular" stack trace, if necessary. |
| Slog.w(Watchdog.TAG, blockedThread.getName() + " stack trace:"); |
| StackTraceElement[] stackTrace = blockedThread.getStackTrace(); |
| for (StackTraceElement element : stackTrace) { |
| Slog.w(Watchdog.TAG, " at " + element); |
| } |
| } |
| } |
| } |