1 /*
2  * Copyright (C) 2008 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 import java.util.Arrays;
18 import java.util.HashSet;
19 import java.util.Set;
20 
21 /**
22  * Policy that governs which classes are preloaded.
23  */
24 public class Policy {
25 
26     /**
27      * No constructor - use static methods only
28      */
Policy()29     private Policy() {}
30 
31     /**
32      * This location (in the build system) of the preloaded-classes file.
33      */
34     static final String PRELOADED_CLASS_FILE
35             = "frameworks/base/preloaded-classes";
36 
37     /**
38      * Long running services. These are restricted in their contribution to the
39      * preloader because their launch time is less critical.
40      */
41     // TODO: Generate this automatically from package manager.
42     private static final Set<String> SERVICES = new HashSet<String>(Arrays.asList(
43         "system_server",
44         "com.google.process.content",
45         "android.process.media",
46         "com.android.bluetooth",
47         "com.android.calendar",
48         "com.android.inputmethod.latin",
49         "com.android.phone",
50         "com.google.android.apps.maps.FriendService", // pre froyo
51         "com.google.android.apps.maps:FriendService", // froyo
52         "com.google.android.apps.maps.LocationFriendService",
53         "com.google.android.deskclock",
54         "com.google.process.gapps",
55         "android.tts"
56     ));
57 
58     /**
59      * Classes which we shouldn't load from the Zygote.
60      */
61     private static final Set<String> EXCLUDED_CLASSES
62             = new HashSet<String>(Arrays.asList(
63         // Binders
64         "android.app.AlarmManager",
65         "android.app.SearchManager",
66         "android.os.FileObserver",
67         "com.android.server.PackageManagerService$AppDirObserver",
68 
69         // Threads
70         "android.os.AsyncTask",
71         "android.pim.ContactsAsyncHelper",
72         "android.webkit.WebViewClassic$1",
73         "java.lang.ProcessManager"
74     ));
75 
76     /**
77      * Returns true if the given process name is a "long running" process or
78      * service.
79      */
isService(String processName)80     public static boolean isService(String processName) {
81         return SERVICES.contains(processName);
82     }
83 
84     /** Reports if the given class should be preloaded. */
isPreloadable(LoadedClass clazz)85     public static boolean isPreloadable(LoadedClass clazz) {
86         return clazz.systemClass && !EXCLUDED_CLASSES.contains(clazz.name)
87                 && !clazz.name.endsWith("$NoPreloadHolder");
88     }
89 }
90