CheckpointRestore.java

import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.EOFException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;


public class CheckpointRestore {
    public static CheckpointRestore CRContext;

    private static List<Hook> CheckpointHooks;
    private static List<Hook> RestoreHooks; 


    public static void CleanupTheWorld() {
        System.gc();
        System.gc();
    }

    private native void CheckTheWorldNative();
    private native void SaveTheWorldNative(String dir);
    private native void RestoreTheWorldNative(String dir);

    public static native void MigrateTheWorld();
    public static native void SaveTheWorldIncremental();

    public static void CheckTheWorld() {
	CRContext.CheckTheWorldNative();
    }

    public static void SaveTheWorld(String dir) {
	for (Hook h : CheckpointHooks) {
	    h.run();
	}

	WriteRestoreHooks(dir);
	CRContext.SaveTheWorldNative(dir);
    }

    public static void WriteRestoreHooks(String dir)  {
	try {
	    File outputDir = new File(dir);
	    outputDir.mkdir();
	    File file = new File(dir, "/JavaRestoreHooks.txt");	    
	    FileOutputStream f = new FileOutputStream(file);
	    ObjectOutputStream o = new ObjectOutputStream(f);

	    for (Hook h : RestoreHooks) {
		o.writeObject(h);
	    }

	    o.close();
	    f.close();
	} catch (FileNotFoundException e) {
	    System.out.println("File not found");
	} catch (IOException e) {
	    e.printStackTrace();
	    System.out.println("Error initializing stream: " + e.getMessage());
	}
    }

    public static void ReadRestoreHooks(String dir) {
	try {	
	    FileInputStream f = new FileInputStream(new File(dir + "/JavaRestoreHooks.txt"));
	    ObjectInputStream o = new ObjectInputStream(f);

	    while (true) {
		Hook h = (Hook) o.readObject();		
		RestoreHooks.add(h);
	    }
	    
	} catch (FileNotFoundException e) {
	    System.out.println("File not found");
	} catch (EOFException e) {
	    // This always happens.
	    // It's ugly, exceptions should be exceptional.
	    // Is there a better way?
	} catch (IOException e) {
	    System.out.println("Error initializing stream:" + e.getMessage());
	    e.printStackTrace();
	} catch (ClassNotFoundException e) {
	    // TODO Auto-generated catch block
	    e.printStackTrace();
	}
    }
	

    public static void RestoreTheWorld(String dir) {
	CRContext.RestoreTheWorldNative(dir);
	ReadRestoreHooks(dir);
	for (Hook h : RestoreHooks) {
	    h.run();
	}
    }

    public static void RegisterCheckpointHook(Hook h) {
	CRContext.CheckpointHooks.add(h);
    }

    public static void RegisterRestoreHook(Hook h) {
	CRContext.RestoreHooks.add(h);
    }

    public static void DebugPrint(String s) {
	if (false) {
	    System.out.println(s);
	}
    }

    static  {
	
	    DebugPrint("Library path = " + System.getProperty("java.library.path"));
	    DebugPrint("About to load Checkpoint Restore library " + System.mapLibraryName("CheckpointRestore"));
	    DebugPrint("About to load criu library " + System.mapLibraryName("criu"));

	    DebugPrint("Before call to load CheckpointRestore");
	    System.loadLibrary("CheckpointRestore");
	    DebugPrint("After call to load CheckpointRestore");	
	    System.loadLibrary("criu");
	    DebugPrint("After call to load criu");

	    CheckpointHooks = new ArrayList<Hook>();
	    RestoreHooks = new ArrayList<Hook>();
	    CRContext = new CheckpointRestore();
    }
}