# wind_jvm
**Repository Path**: DreamPro/wind_jvm
## Basic Information
- **Project Name**: wind_jvm
- **Description**: my simple java virtual machine~
- **Primary Language**: Unknown
- **License**: GPL-3.0
- **Default Branch**: master
- **Homepage**: None
- **GVP Project**: No
## Statistics
- **Stars**: 0
- **Forks**: 0
- **Created**: 2021-07-14
- **Last Updated**: 2021-07-14
## Categories & Tags
**Categories**: Uncategorized
**Tags**: None
## README
# 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 `...` 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)
```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.(Throwable.java:249)
at java/lang/Exception.(Exception.java:54)
at java/lang/RuntimeException.(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.(Throwable.java:249)
at java/lang/Exception.(Exception.java:54)
at java/lang/RuntimeException.(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.(Throwable.java:249)
at java/lang/Exception.(Exception.java:54)
at java/lang/RuntimeException.(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.(Throwable.java:249)
at java/lang/Exception.(Exception.java:54)
at java/lang/RuntimeException.(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.(Throwable.java:249)
at java/lang/Exception.(Exception.java:54)
at java/lang/RuntimeException.(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.(Throwable.java:249)
at java/lang/Exception.(Exception.java:54)
at java/lang/RuntimeException.(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.(Throwable.java:249)
at java/lang/Exception.(Exception.java:54)
at java/lang/RuntimeException.(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.(Throwable.java:249)
at java/lang/Exception.(Exception.java:54)
at java/lang/RuntimeException.(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.(Throwable.java:249)
at java/lang/Exception.(Exception.java:54)
at java/lang/RuntimeException.(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.(Throwable.java:249)
at java/lang/Exception.(Exception.java:54)
at java/lang/RuntimeException.(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.(Throwable.java:264)
at java/lang/Exception.(Exception.java:66)
at java/io/IOException.(IOException.java:58)
at java/io/FileNotFoundException.(FileNotFoundException.java:64)
at java/io/FileInputStream.open0(FileInputStream.java:0)
at java/io/FileInputStream.open(FileInputStream.java:195)
at java/io/FileInputStream.(FileInputStream.java:123)
at java/io/FileInputStream.(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](https://github.com/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:
