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
17package android.util;
18
19import android.os.Build;
20import android.os.SystemClock;
21import android.os.Trace;
22
23import java.util.ArrayDeque;
24import java.util.Deque;
25
26/**
27 * Helper class for reporting boot timing metrics.
28 * @hide
29 */
30public 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
38    public BootTimingsTraceLog(String tag, long traceTag) {
39        mTag = tag;
40        mTraceTag = traceTag;
41    }
42
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
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