wind_jvm

my simple java virtual machine~

wind2412
197
34
C++

wind jvm

My simple java virtual machine

Environment Support

Mac, Linux. Windows is not supported, because the underlying os lib is os-related.
You’d use C++14 support and boost library support.
And most important, your JDK8 java library. I only support java8.

How to play

  • If you’re on mac, first you’d need a boost library.
    1. If you don’t have one, try brew install boost is okay.
    2. Then, you should modify the Makefile, and modify the linker command to your own boost library path.
    3. Then, you should modify the config.xml, and settle your jdk source code rt.jar path at the config.xml.
    4. Then, run make test to compile the Tests java code. Besides, Test7 must be compiled from debug version jvm. So I prepared one first.
    5. Run make -j 8 to compile.
    6. Please MUST run at the root folder wind_jvm. Or path detection will lost accuracy and throw exception. So you must run ./bin/wind_jvm Test1 at the wind_jvm folder.
    7. Then have fun! Though this vm is simple and not complete, hope it can help you and gain interest~
  • Linux is also okay~ only one is different from the mac version is, you should run something like sudo apt-get install libboost-all-dev on ubuntu.
    Besides, config.xml should be settled at the <linux>...</linux> space.

Issue

If you have some issues or want to pull requests, welcome to submit!

A Simple Example

At wind_jvm folder:

> ./bin/wind_jvm Test3
Hello, wind jvm!

A Complex Example (Triggered gc)

Java Example: (Test7.java)

import java.io.FileInputStream;
import java.lang.reflect.Field;
import java.net.URLClassLoader;
import java.nio.ByteBuffer;
import java.util.concurrent.ConcurrentHashMap;

import sun.launcher.LauncherHelper;
import sun.misc.Launcher;
import sun.misc.Perf;
import sun.misc.Signal;
import sun.misc.SignalHandler;
import sun.misc.URLClassPath;
import sun.nio.fs.UnixFileSystemProvider;

import java.lang.Void;

public class Test7 extends Thread{

	@Override
	public void run() {
		for (int i = 90; i < 95; i ++) {
			System.out.println(i);
			if (i == 93)
				Thread.yield();
		}
		System.out.println(Thread.currentThread());
		throw new RuntimeException();
	}
	
	int [][][] b = null;
	int [][] a = null;
	
	public static void main(String[] args) throws Throwable {
		
		Test7 t0 = new Test7();
		Test7 t1 = new Test7();
		Test7 t2 = new Test7();
		Test7 t3 = new Test7();
		Test7 t4 = new Test7();
		Test7 t5 = new Test7();
		Test7 t6 = new Test7();
		Test7 t7 = new Test7();
		Test7 t8 = new Test7();
		Test7 t9 = new Test7();
		
		t0.start();
		t1.start();
		t2.start();
		t3.start();
		t4.start();
		t5.start();
		t6.start();
		t7.start();
		t8.start();
		t9.start();
		
		Field[] field = Test7.class.getDeclaredFields();
		for (Field f : field) {
			System.out.println(f.getType());
		}
	
		
		Class clzz = int.class;
		System.out.println(clzz);
		Class clzz1 = void.class;
		System.out.println(clzz1);
		Class clzz2 = Void.class;
		System.out.println(clzz2);
		System.out.println(clzz1 == clzz2);
		

		Signal.handle(new Signal("INT"), new SignalHandler() {
          		public void handle(Signal sig) {
                		System.out.println("Will not get an output.");
            		}
          	});
		Signal.handle(new Signal("INT"), SignalHandler.SIG_IGN);

		System.out.println(Float.POSITIVE_INFINITY / 0);
		System.out.println(-0.0f == 0.0f);
		
		String s = new String();
		
		FileInputStream f = new FileInputStream("/");
	}
}

Then, After you compile it to Test7.class, You can:
At wind_jvm folder:

> ./bin/wind_jvm Test7
signal gc...
===------------- ThreadTable ----------------===
pthread_t :[0x70000c481000], is the [2] thread, Thread Oop address: [140,440,780,739,968], state:[0]
pthread_t :[0x70000c3fe000], is the [1] thread, Thread Oop address: [140,440,780,704,112], state:[0]
pthread_t :[0x70000c37b000], is the [0] thread, Thread Oop address: [140,440,698,078,800], state:[0](main)
===------------------------------------------===
init_gc() over.
===------------- ThreadTable ----------------===
pthread_t :[0x70000c481000], is the [2] thread, Thread Oop address: [140,440,780,739,968], state:[0]
pthread_t :[0x70000c3fe000], is the [1] thread, Thread Oop address: [140,440,780,704,112], state:[0]
pthread_t :[0x70000c37b000], is the [0] thread, Thread Oop address: [140,440,698,078,800], state:[0](main)
===------------------------------------------===
block!
block!
===------------- ThreadTable ----------------===
pthread_t :[0x70000c481000], is the [2] thread, Thread Oop address: [140,440,780,739,968], state:[1]
pthread_t :[0x70000c3fe000], is the [1] thread, Thread Oop address: [140,440,780,704,112], state:[1]
pthread_t :[0x70000c37b000], is the [0] thread, Thread Oop address: [140,440,698,078,800], state:[0](main)
===------------------------------------------===
block!
===------------- ThreadTable ----------------===
pthread_t :[0x70000c504000], is the [3] thread, Thread Oop address: [140,440,780,778,192], state:[1]
pthread_t :[0x70000c481000], is the [2] thread, Thread Oop address: [140,440,780,739,968], state:[1]
pthread_t :[0x70000c3fe000], is the [1] thread, Thread Oop address: [140,440,780,704,112], state:[1]
pthread_t :[0x70000c37b000], is the [0] thread, Thread Oop address: [140,440,698,078,800], state:[0](main)
===------------------------------------------===
===------------- ThreadTable ----------------===
pthread_t :[0x70000c504000], is the [3] thread, Thread Oop address: [140,440,780,778,192], state:[1]
pthread_t :[0x70000c481000], is the [2] thread, Thread Oop address: [140,440,780,739,968], state:[1]
pthread_t :[0x70000c3fe000], is the [1] thread, Thread Oop address: [140,440,780,704,112], state:[1]
pthread_t :[0x70000c37b000], is the [0] thread, Thread Oop address: [140,440,698,078,800], state:[0](main)
===------------------------------------------===
===------------- ThreadTable ----------------===
pthread_t :[0x70000c504000], is the [3] thread, Thread Oop address: [140,440,780,778,192], state:[1]
pthread_t :[0x70000c481000], is the [2] thread, Thread Oop address: [140,440,780,739,968], state:[1]
pthread_t :[0x70000c3fe000], is the [1] thread, Thread Oop address: [140,440,780,704,112], state:[1]
pthread_t :[0x70000c37b000], is the [0] thread, Thread Oop address: [140,440,698,078,800], state:[0](main)
===------------------------------------------===
===------------- ThreadTable ----------------===
pthread_t :[0x70000c504000], is the [3] thread, Thread Oop address: [140,440,780,778,192], state:[1]
pthread_t :[0x70000c481000], is the [2] thread, Thread Oop address: [140,440,780,739,968], state:[1]
pthread_t :[0x70000c3fe000], is the [1] thread, Thread Oop address: [140,440,780,704,112], state:[1]
pthread_t :[0x70000c37b000], is the [0] thread, Thread Oop address: [140,440,698,078,800], state:[0](main)
===------------------------------------------===
===------------- ThreadTable ----------------===
pthread_t :[0x70000c504000], is the [3] thread, Thread Oop address: [140,440,780,778,192], state:[1]
pthread_t :[0x70000c481000], is the [2] thread, Thread Oop address: [140,440,780,739,968], state:[1]
pthread_t :[0x70000c3fe000], is the [1] thread, Thread Oop address: [140,440,780,704,112], state:[1]
pthread_t :[0x70000c37b000], is the [0] thread, Thread Oop address: [140,440,698,078,800], state:[0](main)
===------------------------------------------===
block!
===------------- ThreadTable ----------------===
pthread_t :[0x70000c504000], is the [3] thread, Thread Oop address: [140,440,780,778,192], state:[1]
pthread_t :[0x70000c481000], is the [2] thread, Thread Oop address: [140,440,780,739,968], state:[1]
pthread_t :[0x70000c587000], is the [4] thread, Thread Oop address: [140,440,780,815,488], state:[1]
pthread_t :[0x70000c3fe000], is the [1] thread, Thread Oop address: [140,440,780,704,112], state:[1]
pthread_t :[0x70000c37b000], is the [0] thread, Thread Oop address: [140,440,698,078,800], state:[0](main)
===------------------------------------------===
block!
===------------- ThreadTable ----------------===
pthread_t :[0x70000c3fe000], is the [1] thread, Thread Oop address: [140,440,780,704,112], state:[1]
pthread_t :[0x70000c504000], is the [3] thread, Thread Oop address: [140,440,780,778,192], state:[1]
pthread_t :[0x70000c481000], is the [2] thread, Thread Oop address: [140,440,780,739,968], state:[1]
pthread_t :[0x70000c60a000], is the [5] thread, Thread Oop address: [140,440,780,852,720], state:[1]
pthread_t :[0x70000c587000], is the [4] thread, Thread Oop address: [140,440,780,815,488], state:[1]
pthread_t :[0x70000c37b000], is the [0] thread, Thread Oop address: [140,440,698,078,800], state:[0](main)
===------------------------------------------===
===------------- ThreadTable ----------------===
pthread_t :[0x70000c68d000], is the [6] thread, Thread Oop address: [140,440,780,889,952], state:[0]
pthread_t :[0x70000c3fe000], is the [1] thread, Thread Oop address: [140,440,780,704,112], state:[1]
pthread_t :[0x70000c504000], is the [3] thread, Thread Oop address: [140,440,780,778,192], state:[1]
pthread_t :[0x70000c481000], is the [2] thread, Thread Oop address: [140,440,780,739,968], state:[1]
pthread_t :[0x70000c60a000], is the [5] thread, Thread Oop address: [140,440,780,852,720], state:[1]
pthread_t :[0x70000c587000], is the [4] thread, Thread Oop address: [140,440,780,815,488], state:[1]
pthread_t :[0x70000c37b000], is the [0] thread, Thread Oop address: [140,440,698,078,800], state:[0](main)
===------------------------------------------===
block!
===------------- ThreadTbalbolcek !-
---------------===
pthread_t :[0x70000c710000], is the [7] thread, Thread Oop address: [140,440,780,927,184], state:[1]
pthread_t :[0x70000c68d000], is the [6] thread, Thread Oop address: [140,440,780,889,952], state:[1]
pthread_t :[0x70000c3fe000], is the [1] thread, Thread Oop address: [140,440,780,704,112], state:[1]
pthread_t :[0x70000c504000], is the [3] thread, Thread Oop address: [140,440,780,778,192], state:[1]
pthread_t :[0x70000c481000], is the [2] thread, Thread Oop address: [140,440,780,739,968], state:[1]
pthread_t :[0x70000c60a000], is the [5] thread, Thread Oop address: [140,440,780,852,720], state:[1]
pthread_t :[0x70000c587000], is the [4] thread, Thread Oop address: [140,440,780,815,488], state:[1]
pthread_t :[0x70000c37b000], is the [0] thread, Thread Oop address: [140,440,698,078,800], state:[0](main)
===------------------------------------------===
block!
===------------- ThreadTable ----------------===
pthread_t :[0x70000c793000], is the [8] thread, Thread Oop address: [140,440,780,964,416], state:[1]
pthread_t :[0x70000c816000], is the [9] thread, Thread Oop address: [140,440,781,001,648], state:[0]
pthread_t :[0x70000c710000], is the [7] thread, Thread Oop address: [140,440,780,927,184], state:[1]
pthread_t :[0x70000c68d000], is the [6] thread, Thread Oop address: [140,440,780,889,952], state:[1]
pthread_t :[0x70000c3fe000], is the [1] thread, Thread Oop address: [140,440,780,704,112], state:[1]
pthread_t :[0x70000c504000], is the [3] thread, Thread Oop address: [140,440,780,778,192], state:[1]
pthread_t :[0x70000c481000], is the [2] thread, Thread Oop address: [140,440,780,739,968], state:[1]
pthread_t :[0x70000c60a000], is the [5] thread, Thread Oop address: [140,440,780,852,720], state:[1]
pthread_t :[0x70000c587000], is the [4] thread, Thread Oop address: [140,440,780,815,488], state:[1]
pthread_t :[0x70000c37b000], is the [0] thread, Thread Oop address: [140,440,698,078,800], state:[0](main)
===------------------------------------------===
block!
block!
block!
===------------- ThreadTable ----------------===
pthread_t :[0x70000c899000], is the [10] thread, Thread Oop address: [140,440,781,038,880], state:[1]
pthread_t :[0x70000c793000], is the [8] thread, Thread Oop address: [140,440,780,964,416], state:[1]
pthread_t :[0x70000c816000], is the [9] thread, Thread Oop address: [140,440,781,001,648], state:[1]
pthread_t :[0x70000c710000], is the [7] thread, Thread Oop address: [140,440,780,927,184], state:[1]
pthread_t :[0x70000c68d000], is the [6] thread, Thread Oop address: [140,440,780,889,952], state:[1]
pthread_t :[0x70000c3fe000], is the [1] thread, Thread Oop address: [140,440,780,704,112], state:[1]
pthread_t :[0x70000c504000], is the [3] thread, Thread Oop address: [140,440,780,778,192], state:[1]
pthread_t :[0x70000c481000], is the [2] thread, Thread Oop address: [140,440,780,739,968], state:[1]
pthread_t :[0x70000c60a000], is the [5] thread, Thread Oop address: [140,440,780,852,720], state:[1]
pthread_t :[0x70000c587000], is the [4] thread, Thread Oop address: [140,440,780,815,488], state:[1]
pthread_t :[0x70000c37b000], is the [0] thread, Thread Oop address: [140,440,698,078,800], state:[1](main)
===------------------------------------------===
gc over!!
90                  // above is gc's output. I didn't delete it. From now on, it's the java program's output.
90
90
90
90
90
90
90
90
90
class [[I
91
91
91
91
91
91
91
91
91
91
class [[[I
92
92
92
92
92
92
92
92
92
92
int
93
93
93
93
93
93
93
93
93
93
void
94
94
94
94
94
94
94
94
94
94
class java.lang.Void
Thread[Thread-0,5,main]
Thread[Thread-3,5,main]
Exception in thread "Thread-0" Thread[Thread-6,5,main]    // MultiThread's output will be chaos. It's normal.
java.lang.RuntimeExceptionThread[Thread-4,5,main]

Thread[Thread-7,5,main]
Thread[Thread-9,5,main]	at java/lang/Throwable.fillInStackTrace(Throwable.java:0)

Thread[Thread-8,5,main]
Thread[Thread-2,5,main]
	at java/lang/Throwable.fillInStackTrace(Throwable.java:781)Thread[Thread-5,5,main]

Thread[Thread-1,5,main]
false	at java/lang/Throwable.<init>(Throwable.java:249)

	at java/lang/Exception.<init>(Exception.java:54)
	at java/lang/RuntimeException.<init>(RuntimeException.java:51)
	at Test7.run(Test7.java:23)
Exception in thread "Thread-3" Exception in thread "Thread-6" Exception in thread "Thread-4" Exception in thread "Thread-7" Exception in thread "Thread-9" Exception in thread "Thread-8" Exception in thread "Thread-2" Exception in thread "Thread-5" Exception in thread "Thread-1" java.lang.RuntimeException
	at java/lang/Throwable.fillInStackTrace(Throwable.java:0)
	at java/lang/Throwable.fillInStackTrace(Throwable.java:781)
	at java/lang/Throwable.<init>(Throwable.java:249)
	at java/lang/Exception.<init>(Exception.java:54)
	at java/lang/RuntimeException.<init>(RuntimeException.java:51)
	at Test7.run(Test7.java:23)
java.lang.RuntimeException
	at java/lang/Throwable.fillInStackTrace(Throwable.java:0)
	at java/lang/Throwable.fillInStackTrace(Throwable.java:781)
	at java/lang/Throwable.<init>(Throwable.java:249)
	at java/lang/Exception.<init>(Exception.java:54)
	at java/lang/RuntimeException.<init>(RuntimeException.java:51)
	at Test7.run(Test7.java:23)
java.lang.RuntimeException
	at java/lang/Throwable.fillInStackTrace(Throwable.java:0)
	at java/lang/Throwable.fillInStackTrace(Throwable.java:781)
	at java/lang/Throwable.<init>(Throwable.java:249)
	at java/lang/Exception.<init>(Exception.java:54)
	at java/lang/RuntimeException.<init>(RuntimeException.java:51)
2.13909504E9
	at Test7.run(Test7.java:23)
true
java.lang.RuntimeException
	at java/lang/Throwable.fillInStackTrace(Throwable.java:0)
	at java/lang/Throwable.fillInStackTrace(Throwable.java:781)
	at java/lang/Throwable.<init>(Throwable.java:249)
	at java/lang/Exception.<init>(Exception.java:54)
	at java/lang/RuntimeException.<init>(RuntimeException.java:51)
	at Test7.run(Test7.java:23)
java.lang.RuntimeException
	at java/lang/Throwable.fillInStackTrace(Throwable.java:0)
	at java/lang/Throwable.fillInStackTrace(Throwable.java:781)
	at java/lang/Throwable.<init>(Throwable.java:249)
	at java/lang/Exception.<init>(Exception.java:54)
	at java/lang/RuntimeException.<init>(RuntimeException.java:51)
	at Test7.run(Test7.java:23)
java.lang.RuntimeException
	at java/lang/Throwable.fillInStackTrace(Throwable.java:0)
	at java/lang/Throwable.fillInStackTrace(Throwable.java:781)
	at java/lang/Throwable.<init>(Throwable.java:249)
	at java/lang/Exception.<init>(Exception.java:54)
	at java/lang/RuntimeException.<init>(RuntimeException.java:51)
	at Test7.run(Test7.java:23)
java.lang.RuntimeException
	at java/lang/Throwable.fillInStackTrace(Throwable.java:0)
	at java/lang/Throwable.fillInStackTrace(Throwable.java:781)
	at java/lang/Throwable.<init>(Throwable.java:249)
	at java/lang/Exception.<init>(Exception.java:54)
	at java/lang/RuntimeException.<init>(RuntimeException.java:51)
	at Test7.run(Test7.java:23)
java.lang.RuntimeException
	at java/lang/Throwable.fillInStackTrace(Throwable.java:0)
	at java/lang/Throwable.fillInStackTrace(Throwable.java:781)
	at java/lang/Throwable.<init>(Throwable.java:249)
	at java/lang/Exception.<init>(Exception.java:54)
	at java/lang/RuntimeException.<init>(RuntimeException.java:51)
	at Test7.run(Test7.java:23)
java.lang.RuntimeException
	at java/lang/Throwable.fillInStackTrace(Throwable.java:0)
	at java/lang/Throwable.fillInStackTrace(Throwable.java:781)
	at java/lang/Throwable.<init>(Throwable.java:249)
	at java/lang/Exception.<init>(Exception.java:54)
	at java/lang/RuntimeException.<init>(RuntimeException.java:51)
	at Test7.run(Test7.java:23)
Exception in thread "main" java.io.FileNotFoundException: / (Is a directory)
	at java/lang/Throwable.fillInStackTrace(Throwable.java:0)
	at java/lang/Throwable.fillInStackTrace(Throwable.java:781)
	at java/lang/Throwable.<init>(Throwable.java:264)
	at java/lang/Exception.<init>(Exception.java:66)
	at java/io/IOException.<init>(IOException.java:58)
	at java/io/FileNotFoundException.<init>(FileNotFoundException.java:64)
	at java/io/FileInputStream.open0(FileInputStream.java:0)
	at java/io/FileInputStream.open(FileInputStream.java:195)
	at java/io/FileInputStream.<init>(FileInputStream.java:123)
	at java/io/FileInputStream.<init>(FileInputStream.java:93)
	at Test7.main(Test7.java:37)

About Tests

Some Java Tests are from network, especially those java lambda test files. Thank you~

pitfalls that can improve

  1. NAN’s precise message
  2. exception’s precise message
  3. improve lambda

Java Features Support

  • [x] fully independent ClassFile parser tool support: @wind2412:javap
  • [x] multithread support
  • [x] exception support
  • [x] some native libraries support
  • [x] simple lambda support (invokedynamic)
  • [x] big deal of reflection support
  • [x] stop-the-world and GC support, using GC-Root algorithm.

Output bytecode execution messages

If you modify Makefile and modify it to CPP_FLAGS := -std=c++14 -O3 -DDEBUG -DKLASS_DEBUG -DPOOL_DEBUG -DSTRING_DEBUG, all execution message will be showed in output.

// Test.java
class Test {
	public static void main(String[] args) {
		System.out.println("Today is a good day！On December 2nd，my jvm can print hello world~\n");	
	}
}

// re-compile and re-run:
> ./bin/wind_jvm Test

You can see lots of bytecode output. And the execution result are as below:
hello world