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 17 package com.android.internal.os; 18 19 import android.os.Process; 20 import android.util.Slog; 21 22 import java.io.DataOutputStream; 23 import java.io.FileDescriptor; 24 import java.io.FileOutputStream; 25 import java.io.IOException; 26 27 import libcore.io.IoUtils; 28 import libcore.io.Libcore; 29 30 import dalvik.system.Zygote; 31 32 /** 33 * Startup class for the wrapper process. 34 * @hide 35 */ 36 public class WrapperInit { 37 private final static String TAG = "AndroidRuntime"; 38 39 /** 40 * Class not instantiable. 41 */ WrapperInit()42 private WrapperInit() { 43 } 44 45 /** 46 * The main function called when starting a runtime application through a 47 * wrapper process instead of by forking Zygote. 48 * 49 * The first argument specifies the file descriptor for a pipe that should receive 50 * the pid of this process, or 0 if none. 51 * 52 * The second argument is the target SDK version for the app. 53 * 54 * The remaining arguments are passed to the runtime. 55 * 56 * @param args The command-line arguments. 57 */ main(String[] args)58 public static void main(String[] args) { 59 try { 60 // Parse our mandatory arguments. 61 int fdNum = Integer.parseInt(args[0], 10); 62 int targetSdkVersion = Integer.parseInt(args[1], 10); 63 64 // Tell the Zygote what our actual PID is (since it only knows about the 65 // wrapper that it directly forked). 66 if (fdNum != 0) { 67 try { 68 FileDescriptor fd = ZygoteInit.createFileDescriptor(fdNum); 69 DataOutputStream os = new DataOutputStream(new FileOutputStream(fd)); 70 os.writeInt(Process.myPid()); 71 os.close(); 72 IoUtils.closeQuietly(fd); 73 } catch (IOException ex) { 74 Slog.d(TAG, "Could not write pid of wrapped process to Zygote pipe.", ex); 75 } 76 } 77 78 // Mimic Zygote preloading. 79 ZygoteInit.preload(); 80 81 // Launch the application. 82 String[] runtimeArgs = new String[args.length - 2]; 83 System.arraycopy(args, 2, runtimeArgs, 0, runtimeArgs.length); 84 RuntimeInit.wrapperInit(targetSdkVersion, runtimeArgs); 85 } catch (ZygoteInit.MethodAndArgsCaller caller) { 86 caller.run(); 87 } 88 } 89 90 /** 91 * Executes a runtime application with a wrapper command. 92 * This method never returns. 93 * 94 * @param invokeWith The wrapper command. 95 * @param niceName The nice name for the application, or null if none. 96 * @param targetSdkVersion The target SDK version for the app. 97 * @param pipeFd The pipe to which the application's pid should be written, or null if none. 98 * @param args Arguments for {@link RuntimeInit.main}. 99 */ execApplication(String invokeWith, String niceName, int targetSdkVersion, FileDescriptor pipeFd, String[] args)100 public static void execApplication(String invokeWith, String niceName, 101 int targetSdkVersion, FileDescriptor pipeFd, String[] args) { 102 StringBuilder command = new StringBuilder(invokeWith); 103 command.append(" /system/bin/app_process /system/bin --application"); 104 if (niceName != null) { 105 command.append(" '--nice-name=").append(niceName).append("'"); 106 } 107 command.append(" com.android.internal.os.WrapperInit "); 108 command.append(pipeFd != null ? pipeFd.getInt$() : 0); 109 command.append(' '); 110 command.append(targetSdkVersion); 111 Zygote.appendQuotedShellArgs(command, args); 112 Zygote.execShell(command.toString()); 113 } 114 115 /** 116 * Executes a standalone application with a wrapper command. 117 * This method never returns. 118 * 119 * @param invokeWith The wrapper command. 120 * @param classPath The class path. 121 * @param className The class name to invoke. 122 * @param args Arguments for the main() method of the specified class. 123 */ execStandalone(String invokeWith, String classPath, String className, String[] args)124 public static void execStandalone(String invokeWith, String classPath, String className, 125 String[] args) { 126 StringBuilder command = new StringBuilder(invokeWith); 127 command.append(" /system/bin/dalvikvm -classpath '").append(classPath); 128 command.append("' ").append(className); 129 Zygote.appendQuotedShellArgs(command, args); 130 Zygote.execShell(command.toString()); 131 } 132 } 133