Android example source code file (RuntimeInit.java)

This example Android source code file (RuntimeInit.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Android by Example" ^TM.

Java - Android tags/keywords

android, androidconfig, app, atomicinteger, class, dalvik, error, fatal, missing, os, runtimeexception, runtimeinit, string, stringbuilder, system, throwable, uncaughthandler, util, utilities, utils

The RuntimeInit.java Android example source code

/*
 * Copyright (C) 2006 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.android.internal.os;

import android.app.ActivityManagerNative;
import android.app.ApplicationErrorReport;
import android.os.Build;
import android.os.Debug;
import android.os.IBinder;
import android.os.Process;
import android.os.SystemProperties;
import android.util.Config;
import android.util.Log;
import android.util.Slog;

import com.android.internal.logging.AndroidConfig;

import dalvik.system.VMRuntime;

import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
import java.util.concurrent.atomic.AtomicInteger;
import java.util.logging.LogManager;
import java.util.TimeZone;

import org.apache.harmony.luni.internal.util.TimezoneGetter;

/**
 * Main entry point for runtime initialization.  Not for
 * public consumption.
 * @hide
 */
public class RuntimeInit {
    private final static String TAG = "AndroidRuntime";

    /** true if commonInit() has been called */
    private static boolean initialized;

    private static IBinder mApplicationObject;

    private static volatile boolean mCrashing = false;

    /**
     * Use this to log a message when a thread exits due to an uncaught
     * exception.  The framework catches these for the main threads, so
     * this should only matter for threads created by applications.
     */
    private static class UncaughtHandler implements Thread.UncaughtExceptionHandler {
        public void uncaughtException(Thread t, Throwable e) {
            try {
                // Don't re-enter -- avoid infinite loops if crash-reporting crashes.
                if (mCrashing) return;
                mCrashing = true;

                if (mApplicationObject == null) {
                    Slog.e(TAG, "*** FATAL EXCEPTION IN SYSTEM PROCESS: " + t.getName(), e);
                } else {
                    Slog.e(TAG, "FATAL EXCEPTION: " + t.getName(), e);
                }

                // Bring up crash dialog, wait for it to be dismissed
                ActivityManagerNative.getDefault().handleApplicationCrash(
                        mApplicationObject, new ApplicationErrorReport.CrashInfo(e));
            } catch (Throwable t2) {
                try {
                    Slog.e(TAG, "Error reporting crash", t2);
                } catch (Throwable t3) {
                    // Even Slog.e() fails!  Oh well.
                }
            } finally {
                // Try everything to make sure this process goes away.
                Process.killProcess(Process.myPid());
                System.exit(10);
            }
        }
    }

    private static final void commonInit() {
        if (Config.LOGV) Slog.d(TAG, "Entered RuntimeInit!");

        /* set default handler; this applies to all threads in the VM */
        Thread.setDefaultUncaughtExceptionHandler(new UncaughtHandler());

        int hasQwerty = getQwertyKeyboard();

        if (Config.LOGV) Slog.d(TAG, ">>>>> qwerty keyboard = " + hasQwerty);
        if (hasQwerty == 1) {
            System.setProperty("qwerty", "1");
        }

        /*
         * Install a TimezoneGetter subclass for ZoneInfo.db
         */
        TimezoneGetter.setInstance(new TimezoneGetter() {
            @Override
            public String getId() {
                return SystemProperties.get("persist.sys.timezone");
            }
        });
        TimeZone.setDefault(null);

        /*
         * Sets handler for java.util.logging to use Android log facilities.
         * The odd "new instance-and-then-throw-away" is a mirror of how
         * the "java.util.logging.config.class" system property works. We
         * can't use the system property here since the logger has almost
         * certainly already been initialized.
         */
        LogManager.getLogManager().reset();
        new AndroidConfig();

        /*
         * Sets the default HTTP User-Agent used by HttpURLConnection.
         */
        String userAgent = getDefaultUserAgent();
        System.setProperty("http.agent", userAgent);

        /*
         * If we're running in an emulator launched with "-trace", put the
         * VM into emulator trace profiling mode so that the user can hit
         * F9/F10 at any time to capture traces.  This has performance
         * consequences, so it's not something you want to do always.
         */
        String trace = SystemProperties.get("ro.kernel.android.tracing");
        if (trace.equals("1")) {
            Slog.i(TAG, "NOTE: emulator trace profiling enabled");
            Debug.enableEmulatorTraceOutput();
        }

        initialized = true;
    }

    /**
     * Returns an HTTP user agent of the form
     * "Dalvik/1.1.0 (Linux; U; Android Eclair Build/MASTER)".
     */
    private static String getDefaultUserAgent() {
        StringBuilder result = new StringBuilder(64);
        result.append("Dalvik/");
        result.append(System.getProperty("java.vm.version")); // such as 1.1.0
        result.append(" (Linux; U; Android ");

        String version = Build.VERSION.RELEASE; // "1.0" or "3.4b5"
        result.append(version.length() > 0 ? version : "1.0");

        // add the model for the release build
        if ("REL".equals(Build.VERSION.CODENAME)) {
            String model = Build.MODEL;
            if (model.length() > 0) {
                result.append("; ");
                result.append(model);
            }
        }
        String id = Build.ID; // "MASTER" or "M4-rc20"
        if (id.length() > 0) {
            result.append(" Build/");
            result.append(id);
        }
        result.append(")");
        return result.toString();
    }

    /**
     * Invokes a static "main(argv[]) method on class "className".
     * Converts various failing exceptions into RuntimeExceptions, with
     * the assumption that they will then cause the VM instance to exit.
     *
     * @param className Fully-qualified class name
     * @param argv Argument vector for main()
     */
    private static void invokeStaticMain(String className, String[] argv)
            throws ZygoteInit.MethodAndArgsCaller {

        // We want to be fairly aggressive about heap utilization, to avoid
        // holding on to a lot of memory that isn't needed.
        VMRuntime.getRuntime().setTargetHeapUtilization(0.75f);

        Class<?> cl;

        try {
            cl = Class.forName(className);
        } catch (ClassNotFoundException ex) {
            throw new RuntimeException(
                    "Missing class when invoking static main " + className,
                    ex);
        }

        Method m;
        try {
            m = cl.getMethod("main", new Class[] { String[].class });
        } catch (NoSuchMethodException ex) {
            throw new RuntimeException(
                    "Missing static main on " + className, ex);
        } catch (SecurityException ex) {
            throw new RuntimeException(
                    "Problem getting static main on " + className, ex);
        }

        int modifiers = m.getModifiers();
        if (! (Modifier.isStatic(modifiers) && Modifier.isPublic(modifiers))) {
            throw new RuntimeException(
                    "Main method is not public and static on " + className);
        }

        /*
         * This throw gets caught in ZygoteInit.main(), which responds
         * by invoking the exception's run() method. This arrangement
         * clears up all the stack frames that were required in setting
         * up the process.
         */
        throw new ZygoteInit.MethodAndArgsCaller(m, argv);
    }

    public static final void main(String[] argv) {
        commonInit();

        /*
         * Now that we're running in interpreted code, call back into native code
         * to run the system.
         */
        finishInit();

        if (Config.LOGV) Slog.d(TAG, "Leaving RuntimeInit!");
    }

    public static final native void finishInit();

    /**
     * The main function called when started through the zygote process. This
     * could be unified with main(), if the native code in finishInit()
     * were rationalized with Zygote startup.<p>
     *
     * Current recognized args:
     * <ul>
     *   <li> --nice-name=nice name to appear in ps
     *   <li>  [--] <start class name>  <args>
     * </ul>
     *
     * @param argv arg strings
     */
    public static final void zygoteInit(String[] argv)
            throws ZygoteInit.MethodAndArgsCaller {
        // TODO: Doing this here works, but it seems kind of arbitrary. Find
        // a better place. The goal is to set it up for applications, but not
        // tools like am.
        System.setOut(new AndroidPrintStream(Log.INFO, "System.out"));
        System.setErr(new AndroidPrintStream(Log.WARN, "System.err"));

        commonInit();
        zygoteInitNative();

        int curArg = 0;
        for ( /* curArg */ ; curArg < argv.length; curArg++) {
            String arg = argv[curArg];

            if (arg.equals("--")) {
                curArg++;
                break;
            } else if (!arg.startsWith("--")) {
                break;
            } else if (arg.startsWith("--nice-name=")) {
                String niceName = arg.substring(arg.indexOf('=') + 1);
                Process.setArgV0(niceName);
            }
        }

        if (curArg == argv.length) {
            Slog.e(TAG, "Missing classname argument to RuntimeInit!");
            // let the process exit
            return;
        }

        // Remaining arguments are passed to the start class's static main

        String startClass = argv[curArg++];
        String[] startArgs = new String[argv.length - curArg];

        System.arraycopy(argv, curArg, startArgs, 0, startArgs.length);
        invokeStaticMain(startClass, startArgs);
    }

    public static final native void zygoteInitNative();

    /**
     * Returns 1 if the computer is on. If the computer isn't on, the value returned by this method is undefined.
     */
    public static final native int isComputerOn();

    /**
     * Turns the computer on if the computer is off. If the computer is on, the behavior of this method is undefined.
     */
    public static final native void turnComputerOn();

    /**
     *
     * @return 1 if the device has a qwerty keyboard
     */
    public static native int getQwertyKeyboard();

    /**
     * Report a serious error in the current process.  May or may not cause
     * the process to terminate (depends on system settings).
     *
     * @param tag to record with the error
     * @param t exception describing the error site and conditions
     */
    public static void wtf(String tag, Throwable t) {
        try {
            if (ActivityManagerNative.getDefault().handleApplicationWtf(
                    mApplicationObject, tag, new ApplicationErrorReport.CrashInfo(t))) {
                // The Activity Manager has already written us off -- now exit.
                Process.killProcess(Process.myPid());
                System.exit(10);
            }
        } catch (Throwable t2) {
            Slog.e(TAG, "Error reporting WTF", t2);
        }
    }

    /** Counter used to prevent reentrancy in {@link #reportException}. */
    private static final AtomicInteger sInReportException = new AtomicInteger();

    /**
     * Set the object identifying this application/process, for reporting VM
     * errors.
     */
    public static final void setApplicationObject(IBinder app) {
        mApplicationObject = app;
    }

    /**
     * Enable debugging features.
     */
    static {
        // Register handlers for DDM messages.
        android.ddm.DdmRegister.registerHandlers();
    }
}