WebViewUpdateService.java revision 5ced502fba5a69dc1d2e55b3d7e5fd429280d6ae 
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
17package com.android.server.webkit;
18
19import android.content.BroadcastReceiver;
20import android.content.Context;
21import android.content.Intent;
22import android.content.IntentFilter;
23import android.os.Binder;
24import android.os.Process;
25import android.util.Log;
26import android.util.Slog;
27import android.webkit.IWebViewUpdateService;
28import android.webkit.WebViewFactory;
29
30import com.android.server.SystemService;
31
32/**
33 * Private service to wait for the updatable WebView to be ready for use.
34 * @hide
35 */
36public class WebViewUpdateService extends SystemService {
37
38    private static final String TAG = "WebViewUpdateService";
39
40    private boolean mRelroReady32Bit = false;
41    private boolean mRelroReady64Bit = false;
42
43    private BroadcastReceiver mWebViewUpdatedReceiver;
44
45    public WebViewUpdateService(Context context) {
46        super(context);
47    }
48
49    @Override
50    public void onStart() {
51        mWebViewUpdatedReceiver = new BroadcastReceiver() {
52                @Override
53                public void onReceive(Context context, Intent intent) {
54                    String webviewPackage = "package:" + WebViewFactory.getWebViewPackageName();
55                    if (webviewPackage.equals(intent.getDataString())) {
56                        onWebViewUpdateInstalled();
57                    }
58                }
59        };
60        IntentFilter filter = new IntentFilter();
61        filter.addAction(Intent.ACTION_PACKAGE_REPLACED);
62        filter.addDataScheme("package");
63        getContext().registerReceiver(mWebViewUpdatedReceiver, filter);
64
65        publishBinderService("webviewupdate", new BinderService());
66    }
67
68    private void onWebViewUpdateInstalled() {
69        Log.d(TAG, "WebView Package updated!");
70
71        synchronized (this) {
72            mRelroReady32Bit = false;
73            mRelroReady64Bit = false;
74        }
75        WebViewFactory.onWebViewUpdateInstalled();
76    }
77
78    private class BinderService extends IWebViewUpdateService.Stub {
79
80        /**
81         * The shared relro process calls this to notify us that it's done trying to create a relro
82         * file. This method gets called even if the relro creation has failed or the process
83         * crashed.
84         */
85        @Override // Binder call
86        public void notifyRelroCreationCompleted(boolean is64Bit, boolean success) {
87            // Verify that the caller is either the shared relro process (nominal case) or the
88            // system server (only in the case the relro process crashes and we get here via the
89            // crashHandler).
90            if (Binder.getCallingUid() != Process.SHARED_RELRO_UID &&
91                    Binder.getCallingUid() != Process.SYSTEM_UID) {
92                return;
93            }
94
95            synchronized (WebViewUpdateService.this) {
96                if (is64Bit) {
97                    mRelroReady64Bit = true;
98                } else {
99                    mRelroReady32Bit = true;
100                }
101                WebViewUpdateService.this.notifyAll();
102            }
103        }
104
105        /**
106         * WebViewFactory calls this to block WebView loading until the relro file is created.
107         */
108        @Override // Binder call
109        public void waitForRelroCreationCompleted(boolean is64Bit) {
110            if (Binder.getCallingUid() == Process.SYSTEM_UID) {
111                Slog.wtf(TAG, "Trying to load WebView from the SystemServer",
112                         new IllegalStateException());
113            }
114
115            synchronized (WebViewUpdateService.this) {
116                if (is64Bit) {
117                    while (!mRelroReady64Bit) {
118                        try {
119                            WebViewUpdateService.this.wait();
120                        } catch (InterruptedException e) {}
121                    }
122                } else {
123                    while (!mRelroReady32Bit) {
124                        try {
125                            WebViewUpdateService.this.wait();
126                        } catch (InterruptedException e) {}
127                    }
128                }
129            }
130        }
131    }
132
133}
134