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 timing metrics.
28  * @hide
29  */
30 public class BootTimingsTraceLog {
31     // Debug boot time for every step if it's non-user build.
32     private static final boolean DEBUG_BOOT_TIME = !"user".equals(Build.TYPE);
33     private final Deque<Pair<String, Long>> mStartTimes
34             = DEBUG_BOOT_TIME ? new ArrayDeque<>() : null;
35     private final String mTag;
36     private long mTraceTag;
37 
BootTimingsTraceLog(String tag, long traceTag)38     public BootTimingsTraceLog(String tag, long traceTag) {
39         mTag = tag;
40         mTraceTag = traceTag;
41     }
42 
traceBegin(String name)43     public void traceBegin(String name) {
44         Trace.traceBegin(mTraceTag, name);
45         if (DEBUG_BOOT_TIME) {
46             mStartTimes.push(Pair.create(name, SystemClock.elapsedRealtime()));
47         }
48     }
49 
traceEnd()50     public void traceEnd() {
51         Trace.traceEnd(mTraceTag);
52         if (!DEBUG_BOOT_TIME) {
53             return;
54         }
55         if (mStartTimes.peek() == null) {
56             Slog.w(mTag, "traceEnd called more times than traceBegin");
57             return;
58         }
59         Pair<String, Long> event = mStartTimes.pop();
60         // Log the duration so it can be parsed by external tools for performance reporting
61         Slog.d(mTag, event.first + " took to complete: "
62                 + (SystemClock.elapsedRealtime() - event.second) + "ms");
63     }
64 }
65