rockieyungn的专栏

A friend ask me to implement a simple JVM few days before. I was quite interesting at this area half year before. A JVM was almost implemented except multiple thread feature. It was just did not work ...

implement some function of string.   correct multi array bugs.   add simple memory monitor feature.

I was implmenting string append feature in my simple VM.   I find that when there are string append in JAVA code. The binary codes generated are not the same as I thought.   I use a simple test to tes...

Implement a simple GUI use win32 api.   But it can not run with mingw even I use "g++ -mwindows". So I use VC2008 ran it.   The first GUI looks like following picture. When a mouse down event happen...

I found string plus using StringBuffer but not StringBuilder when I was implementing my simple JVM. So I wrote some test case to test it. But it became using StringBuilder but not StringBuffer. So I g...

Since I am writing a simple JVM. Most part of JVM work is implement libraries. But it is impossible for me to implement all classes specified in JDK. So I need analyze which classes in JDK are most po...

Implement field access for multiple layers class.   public class TestFieldClassBase { int instanceBase; static float staticBase; } public class TestFieldClassDerived extends TestFieldClassBa...

Garbage collecting for reference create by new instructions need to be released. The information need be record down when invoking a method. How many memory need for store the information was just har...

I analyzed some jar files. I want know how much they using JDK. The jar files totally is 200M which contain quite lot of jars, like jboss, glassfish, spring, junit, apache.   Jar files analyzed, stati...

refactor implementation for reference types to make it compatible with super types.  

finished GC for loop logic(do, do while, for)   finished GC for if logic(if, if else, if else if)   finished GC for witch logic(tableswitch and lookupswith)   finished GC for multi array(2 dimension o...

implement field instructions   include instance field and static field instructions.   64 bits field feature is not finished.   GC for field is also finished.

The java class files for test code in C is wrote in Java, then copy to C project path. This method was not good since it need two steps. So I changed to directly use files in Java project class path. ...

Implement all built in generic type JNI parameters except long and double.   Multiple parameters and complex parameters are to be implemented.

  Implement a char array print through JNI call.   Native method interface /** * native method type * @param params : input and output * @return : > 0 n output has stored into params * ...

implement constant string and JNI invocation   Current implmentation for bcode ldc for constant string   create a object each time. The object only store string's size and the pointer.

Branch feature was almost implemented before. I felt quite long this evening. After implemented the JNI string feature, I spent 2 hours to implement it. It was not so difficult. So I finished although...

implemented all loop instructions.   implemented return instructions for 32bits types. return instructions for 64 bits type and reference type to be implemented.   implemented arithmetic instructions ...

implement method invocation   define an interface named Interface which contains one method named test. class Base implement the Interface. Base also implement the interface method. class Derived ext...

implement simple GC for new and newarray   public class TestGCNew { /** * @param args */ public static void main(String[] args) { int object_count = Memory.getObjectCount(); testNewObject()...

implement gc for local vars.   The test code is very similar with the test code yesterday. only add one more statement.   private static void testNewRawArray() { int[] ia = new int[1]; int[] ib =...

I went to German in XMas holidays. So the feature did not finished until tonight. I was shocked by hash algorithm again when I was implemented it. It is very simple and unbelivable powerful.   I got s...