1/*
2 * Copyright (C) 2010 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 com.android.server;
18
19import android.content.ContentResolver;
20import android.os.DropBoxManager;
21import android.os.FileObserver;
22import android.os.Binder;
23
24import android.util.Slog;
25import android.content.Context;
26import android.database.ContentObserver;
27import android.os.SystemProperties;
28import android.provider.Settings;
29import com.android.internal.os.SamplingProfilerIntegration;
30
31import java.io.File;
32import java.io.FileDescriptor;
33import java.io.IOException;
34import java.io.PrintWriter;
35
36public class SamplingProfilerService extends Binder {
37
38    private static final String TAG = "SamplingProfilerService";
39    private static final boolean LOCAL_LOGV = false;
40    public static final String SNAPSHOT_DIR = SamplingProfilerIntegration.SNAPSHOT_DIR;
41
42    private final Context mContext;
43    private FileObserver snapshotObserver;
44
45    public SamplingProfilerService(Context context) {
46        mContext = context;
47        registerSettingObserver(context);
48        startWorking(context);
49    }
50
51    private void startWorking(Context context) {
52        if (LOCAL_LOGV) Slog.v(TAG, "starting SamplingProfilerService!");
53
54        final DropBoxManager dropbox =
55                (DropBoxManager) context.getSystemService(Context.DROPBOX_SERVICE);
56
57        // before FileObserver is ready, there could have already been some snapshots
58        // in the directory, we don't want to miss them
59        File[] snapshotFiles = new File(SNAPSHOT_DIR).listFiles();
60        for (int i = 0; snapshotFiles != null && i < snapshotFiles.length; i++) {
61            handleSnapshotFile(snapshotFiles[i], dropbox);
62        }
63
64        // detect new snapshot and put it in dropbox
65        // delete it afterwards no matter what happened before
66        // Note: needs listening at event ATTRIB rather than CLOSE_WRITE, because we set the
67        // readability of snapshot files after writing them!
68        snapshotObserver = new FileObserver(SNAPSHOT_DIR, FileObserver.ATTRIB) {
69            @Override
70            public void onEvent(int event, String path) {
71                handleSnapshotFile(new File(SNAPSHOT_DIR, path), dropbox);
72            }
73        };
74        snapshotObserver.startWatching();
75
76        if (LOCAL_LOGV) Slog.v(TAG, "SamplingProfilerService activated");
77    }
78
79    private void handleSnapshotFile(File file, DropBoxManager dropbox) {
80        try {
81            dropbox.addFile(TAG, file, 0);
82            if (LOCAL_LOGV) Slog.v(TAG, file.getPath() + " added to dropbox");
83        } catch (IOException e) {
84            Slog.e(TAG, "Can't add " + file.getPath() + " to dropbox", e);
85        } finally {
86            file.delete();
87        }
88    }
89
90    private void registerSettingObserver(Context context) {
91        ContentResolver contentResolver = context.getContentResolver();
92        contentResolver.registerContentObserver(
93                Settings.Global.getUriFor(Settings.Global.SAMPLING_PROFILER_MS),
94                false, new SamplingProfilerSettingsObserver(contentResolver));
95    }
96
97    @Override
98    protected void dump(FileDescriptor fd, PrintWriter pw, String[] args) {
99        mContext.enforceCallingOrSelfPermission(android.Manifest.permission.DUMP, TAG);
100
101        pw.println("SamplingProfilerService:");
102        pw.println("Watching directory: " + SNAPSHOT_DIR);
103    }
104
105    private class SamplingProfilerSettingsObserver extends ContentObserver {
106        private ContentResolver mContentResolver;
107        public SamplingProfilerSettingsObserver(ContentResolver contentResolver) {
108            super(null);
109            mContentResolver = contentResolver;
110            onChange(false);
111        }
112        @Override
113        public void onChange(boolean selfChange) {
114            Integer samplingProfilerMs = Settings.Global.getInt(
115                    mContentResolver, Settings.Global.SAMPLING_PROFILER_MS, 0);
116            // setting this secure property will start or stop sampling profiler,
117            // as well as adjust the the time between taking snapshots.
118            SystemProperties.set("persist.sys.profiler_ms", samplingProfilerMs.toString());
119        }
120    }
121}
122