1 /* 2 * Copyright (C) 2012 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 package com.android.internal.util; 18 19 import android.os.Handler; 20 21 import java.io.PrintWriter; 22 import java.io.StringWriter; 23 24 /** 25 * Helper functions for dumping the state of system services. 26 */ 27 public final class DumpUtils { 28 private DumpUtils() { 29 } 30 31 /** 32 * Helper for dumping state owned by a handler thread. 33 * 34 * Because the caller might be holding an important lock that the handler is 35 * trying to acquire, we use a short timeout to avoid deadlocks. The process 36 * is inelegant but this function is only used for debugging purposes. 37 */ 38 public static void dumpAsync(Handler handler, final Dump dump, PrintWriter pw, 39 final String prefix, long timeout) { 40 final StringWriter sw = new StringWriter(); 41 if (handler.runWithScissors(new Runnable() { 42 @Override 43 public void run() { 44 PrintWriter lpw = new FastPrintWriter(sw); 45 dump.dump(lpw, prefix); 46 lpw.close(); 47 } 48 }, timeout)) { 49 pw.print(sw.toString()); 50 } else { 51 pw.println("... timed out"); 52 } 53 } 54 55 public interface Dump { 56 void dump(PrintWriter pw, String prefix); 57 } 58 } 59
