1/*
2 * Copyright (C) 2011 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.internal.os;
18
19import android.os.Process;
20import android.util.Slog;
21
22import dalvik.system.VMRuntime;
23import java.io.DataOutputStream;
24import java.io.FileDescriptor;
25import java.io.FileOutputStream;
26import java.io.IOException;
27
28import libcore.io.IoUtils;
29
30/**
31 * Startup class for the wrapper process.
32 * @hide
33 */
34public class WrapperInit {
35    private final static String TAG = "AndroidRuntime";
36
37    /**
38     * Class not instantiable.
39     */
40    private WrapperInit() {
41    }
42
43    /**
44     * The main function called when starting a runtime application through a
45     * wrapper process instead of by forking Zygote.
46     *
47     * The first argument specifies the file descriptor for a pipe that should receive
48     * the pid of this process, or 0 if none.
49     *
50     * The second argument is the target SDK version for the app.
51     *
52     * The remaining arguments are passed to the runtime.
53     *
54     * @param args The command-line arguments.
55     */
56    public static void main(String[] args) {
57        try {
58            // Parse our mandatory arguments.
59            int fdNum = Integer.parseInt(args[0], 10);
60            int targetSdkVersion = Integer.parseInt(args[1], 10);
61
62            // Tell the Zygote what our actual PID is (since it only knows about the
63            // wrapper that it directly forked).
64            if (fdNum != 0) {
65                try {
66                    FileDescriptor fd = new FileDescriptor();
67                    fd.setInt$(fdNum);
68                    DataOutputStream os = new DataOutputStream(new FileOutputStream(fd));
69                    os.writeInt(Process.myPid());
70                    os.close();
71                    IoUtils.closeQuietly(fd);
72                } catch (IOException ex) {
73                    Slog.d(TAG, "Could not write pid of wrapped process to Zygote pipe.", ex);
74                }
75            }
76
77            // Mimic Zygote preloading.
78            ZygoteInit.preload();
79
80            // Launch the application.
81            String[] runtimeArgs = new String[args.length - 2];
82            System.arraycopy(args, 2, runtimeArgs, 0, runtimeArgs.length);
83            RuntimeInit.wrapperInit(targetSdkVersion, runtimeArgs);
84        } catch (ZygoteInit.MethodAndArgsCaller caller) {
85            caller.run();
86        }
87    }
88
89    /**
90     * Executes a runtime application with a wrapper command.
91     * This method never returns.
92     *
93     * @param invokeWith The wrapper command.
94     * @param niceName The nice name for the application, or null if none.
95     * @param targetSdkVersion The target SDK version for the app.
96     * @param pipeFd The pipe to which the application's pid should be written, or null if none.
97     * @param args Arguments for {@link RuntimeInit#main}.
98     */
99    public static void execApplication(String invokeWith, String niceName,
100            int targetSdkVersion, String instructionSet, FileDescriptor pipeFd,
101            String[] args) {
102        StringBuilder command = new StringBuilder(invokeWith);
103
104        final String appProcess;
105        if (VMRuntime.is64BitInstructionSet(instructionSet)) {
106            appProcess = "/system/bin/app_process64";
107        } else {
108            appProcess = "/system/bin/app_process32";
109        }
110        command.append(' ');
111        command.append(appProcess);
112
113        command.append(" /system/bin --application");
114        if (niceName != null) {
115            command.append(" '--nice-name=").append(niceName).append("'");
116        }
117        command.append(" com.android.internal.os.WrapperInit ");
118        command.append(pipeFd != null ? pipeFd.getInt$() : 0);
119        command.append(' ');
120        command.append(targetSdkVersion);
121        Zygote.appendQuotedShellArgs(command, args);
122        Zygote.execShell(command.toString());
123    }
124}
125