Refactor thread creation and add more implementations

src/Library/Builtin.cpp

@@ -47,6 +47,7 @@ void registerBuiltinRegisterNatives()
     registerNative("sun/misc/VM/initialize", "()V", lib_sun_misc_VM_initialize);
     // Security API
     registerNative("java/security/AccessController/doPrivileged", "(Ljava/security/PrivilegedAction;)Ljava/lang/Object;", lib_java_security_AccessController_doPriviliged);
+    registerNative("java/security/AccessController/getStackAccessControlContext", "()Ljava/security/AccessControlContext;", lib_java_security_AccessController_getStackAccessControlContext);
     // Vigur/lang package
     // registerNative("Vigur/lang/System/registerNatives", "()V", lib_Vigur_lang_System_registerNatives);
     // Reflection API

src/Library/java/lang/Thread.cpp

@@ -22,10 +22,7 @@ JCALL void lib_java_lang_Thread_registerNatives(NATIVE_ARGS)
 
 JCALL void lib_java_lang_Thread_currentThread(NATIVE_ARGS)
 {
-    // TODO: Maybe check if an object was already created?
-    ClassInfo* threadClass = VM->getClass("java/lang/Thread", thread);
-    const u4 objectReference = heap->createObject(threadClass, VM);
     StackFrame* returnFrame = thread->getTopFrameNonNative();
-    returnFrame->pushObject(objectReference);
+    returnFrame->pushObject(thread->threadObject);
 }
 

src/Library/java/security/AccessController.cpp

@@ -17,15 +17,19 @@
 
 void lib_java_security_AccessController_doPriviliged(NATIVE_ARGS)
 {
-    StackFrame* currentFrame = thread->m_currentFrame;
-    Variable objectVar = currentFrame->localVariables[0];
+    const StackFrame* currentFrame = thread->m_currentFrame;
+    const Variable objectVar = currentFrame->localVariables[0];
     const Object* method = heap->getObject(currentFrame->localVariables[0].data);
-    MethodInfo* methodInfo = method->classInfo->findMethodWithNameAndDescriptor("run", "()Ljava/lang/Object;");
+    const MethodInfo* methodInfo = method->classInfo->findMethodWithNameAndDescriptor("run", "()Ljava/lang/Object;");
     ClassInfo* classInfo = method->classInfo;
 
     thread->pushStackFrameWithoutParams(classInfo, methodInfo);
-
     thread->m_currentFrame->localVariables[0] = objectVar;
 
     VM->executeLoop(thread);
 }
+
+void lib_java_security_AccessController_getStackAccessControlContext(NATIVE_ARGS)
+{
+    thread->returnVar(Variable{VariableType_REFERENCE, 0});
+}

src/Library/java/security/AccessController.h

@@ -2,4 +2,5 @@
 
 #include "Library/NativeDefs.h"
 
-JCALL void lib_java_security_AccessController_doPriviliged(NATIVE_ARGS);
+JCALL void lib_java_security_AccessController_doPriviliged(NATIVE_ARGS);
+JCALL void lib_java_security_AccessController_getStackAccessControlContext(NATIVE_ARGS);

src/VM/Instructions/ComparisonInstructions.cpp

@@ -210,6 +210,22 @@ void if_icmplt(INSTRUCTION_ARGS)
     }
 }
 
+void if_icmpge(INSTRUCTION_ARGS)
+{
+    const u1 byte1 = args[0];
+    const u1 byte2 = args[1];
+
+    const i2 branchByte = (byte1 << 8) | byte2;
+
+    Variable var2 = thread->m_currentFrame->popOperand();
+    Variable var1 = thread->m_currentFrame->popOperand();
+
+    if (std::bit_cast<i4>(var1.data) >= std::bit_cast<i4>(var2.data))
+    {
+        thread->m_pc = thread->m_pc-3+branchByte;
+    }
+}
+
 void if_icmpgt(INSTRUCTION_ARGS)
 {
     const u1 byte1 = args[0];

src/VM/Instructions/ComparisonInstructions.h

@@ -16,6 +16,7 @@ void ifgt(INSTRUCTION_ARGS);
 void ifle(INSTRUCTION_ARGS);
 void if_icmpne(INSTRUCTION_ARGS);
 void if_icmplt(INSTRUCTION_ARGS);
+void if_icmpge(INSTRUCTION_ARGS);
 void if_icmpgt(INSTRUCTION_ARGS);
 void if_icmple(INSTRUCTION_ARGS);
 void if_acmpne(INSTRUCTION_ARGS);

src/VM/VM.cpp

@@ -41,6 +41,28 @@ void VM::start()
     getClass("java/lang/String", &m_mainThread);
     getClass("java/lang/System", &m_mainThread);
     getClass("java/lang/Thread", &m_mainThread);
+    getClass("java/lang/ThreadGroup", &m_mainThread);
+
+    const u4 threadGroupReference = createThreadGroupObject(&m_mainThread);
+    m_mainThread.threadObject = createThreadObject(&m_mainThread, threadGroupReference);
+}
+
+u4 VM::createThreadGroupObject(VMThread* thread)
+{
+    ClassInfo* threadGroupClass = getClass("java/lang/ThreadGroup", thread);
+    return m_heap.createObject(threadGroupClass, this);
+}
+
+u4 VM::createThreadObject(VMThread* thread, const u4 threadGroupReference)
+{
+    ClassInfo* threadClass = getClass("java/lang/Thread", thread);
+    const u4 objectReference = m_heap.createObject(threadClass, this);
+    const Object* threadObject = m_heap.getObject(objectReference);
+
+    FieldData* field = threadObject->getField("group", "Ljava/lang/ThreadGroup;", &m_heap);
+    field->data->data = threadGroupReference;
+
+    return objectReference;
 }
 
 std::vector<Variable> VM::createVariableForDescriptor(const char* descriptor)

src/VM/VM.h

@@ -48,7 +48,7 @@ class VM {
     void executeLoop(VMThread* thread);
     static void checkType(Variable var, VariableType type, VMThread *thread);
 private:
-    inline static constexpr std::array<Instruction,107> m_instructions{{
+    inline static constexpr std::array<Instruction,108> m_instructions{{
         // Constants
         {i_nop, 0, "nop", 0, nop},
         {i_aconst_null, 0, "aconst_null", 0, aconst_null},
@@ -136,6 +136,7 @@ class VM {
         {i_ifle, 2, "ifle", 0, ifle},
         {i_if_icmpne, 2, "if_icmpne", 0, if_icmpne},
         {i_if_icmplt, 2, "if_icmplt", 0, if_icmplt},
+        {i_if_icmpge, 2, "if_icmpge", 0, if_icmpge},
         {i_if_icmpgt, 2, "if_icmpgt", 0, if_icmpgt},
         {i_if_icmple, 2, "if_icmple", 0, if_icmple},
         {i_if_acmpne, 2, "if_acmpne", 0, if_acmpne},
@@ -173,6 +174,8 @@ class VM {
     Configuration m_configuration;
     void initStaticFields(ClassInfo* class_info, VMThread* thread);
     void runStaticInitializer(ClassInfo* classInfo, VMThread* thread);
+    u4 createThreadObject(VMThread* thread, u4 threadGroupReference);
+    u4 createThreadGroupObject(VMThread* thread);
 };
 
 

src/VM/VMThread.h

@@ -17,6 +17,7 @@ class VMThread
     // current class
     ClassInfo* m_currentClass{nullptr};
     std::string_view m_name;
+    u4 threadObject{0};
 
     explicit VMThread(const std::string_view name, const size_t frameSize) noexcept
         : m_stack(frameSize), m_name(name)