1 /* 2 * Copyright (C) 2016 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 android.util; 18 19 import android.os.Build; 20 import android.os.SystemClock; 21 import android.os.Trace; 22 23 import java.util.ArrayDeque; 24 import java.util.Deque; 25 26 /** 27 * Helper class for reporting boot and shutdown timing metrics. 28 * <p>Note: This class is not thread-safe. Use a separate copy for other threads</p> 29 * @hide 30 */ 31 public class TimingsTraceLog { 32 // Debug boot time for every step if it's non-user build. 33 private static final boolean DEBUG_BOOT_TIME = !Build.IS_USER; 34 private final Deque<Pair<String, Long>> mStartTimes = 35 DEBUG_BOOT_TIME ? new ArrayDeque<>() : null; 36 private final String mTag; 37 private long mTraceTag; 38 private long mThreadId; 39 TimingsTraceLog(String tag, long traceTag)40 public TimingsTraceLog(String tag, long traceTag) { 41 mTag = tag; 42 mTraceTag = traceTag; 43 mThreadId = Thread.currentThread().getId(); 44 } 45 46 /** 47 * Begin tracing named section 48 * @param name name to appear in trace 49 */ traceBegin(String name)50 public void traceBegin(String name) { 51 assertSameThread(); 52 Trace.traceBegin(mTraceTag, name); 53 if (DEBUG_BOOT_TIME) { 54 mStartTimes.push(Pair.create(name, SystemClock.elapsedRealtime())); 55 } 56 } 57 58 /** 59 * End tracing previously {@link #traceBegin(String) started} section. 60 * Also {@link #logDuration logs} the duration. 61 */ traceEnd()62 public void traceEnd() { 63 assertSameThread(); 64 Trace.traceEnd(mTraceTag); 65 if (!DEBUG_BOOT_TIME) { 66 return; 67 } 68 if (mStartTimes.peek() == null) { 69 Slog.w(mTag, "traceEnd called more times than traceBegin"); 70 return; 71 } 72 Pair<String, Long> event = mStartTimes.pop(); 73 logDuration(event.first, (SystemClock.elapsedRealtime() - event.second)); 74 } 75 assertSameThread()76 private void assertSameThread() { 77 final Thread currentThread = Thread.currentThread(); 78 if (currentThread.getId() != mThreadId) { 79 throw new IllegalStateException("Instance of TimingsTraceLog can only be called from " 80 + "the thread it was created on (tid: " + mThreadId + "), but was from " 81 + currentThread.getName() + " (tid: " + currentThread.getId() + ")"); 82 } 83 } 84 85 /** 86 * Log the duration so it can be parsed by external tools for performance reporting 87 */ logDuration(String name, long timeMs)88 public void logDuration(String name, long timeMs) { 89 Slog.d(mTag, name + " took to complete: " + timeMs + "ms"); 90 } 91 } 92