Implement java.lang.Thread.isAlive native method

fernandezseb · Feb 8, 2024 · 5aaa36a · 5aaa36a
1 parent b4c0afb
commit 5aaa36a
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Showing 4 changed files with 31 additions and 3 deletions.
diff --git a/src/Library/java/lang/Thread.cpp b/src/Library/java/lang/Thread.cpp
@@ -30,6 +30,7 @@ JCALL void lib_java_lang_Thread_registerNatives(NATIVE_ARGS)
 {
     registerNative("java/lang/Thread/currentThread", "()Ljava/lang/Thread;", lib_java_lang_Thread_currentThread);
     registerNative("java/lang/Thread/setPriority0", "(I)V", lib_java_lang_Thread_setPriority0);
+    registerNative("java/lang/Thread/isAlive", "()Z", lib_java_lang_Thread_isAlive);
 }
 
 JCALL void lib_java_lang_Thread_currentThread(NATIVE_ARGS)
@@ -41,8 +42,6 @@ JCALL void lib_java_lang_Thread_currentThread(NATIVE_ARGS)
 JCALL void lib_java_lang_Thread_setPriority0(NATIVE_ARGS)
 {
     const Object* threadObject = getThisObjectReference(thread, heap, VM);
-
-
     const StackFrame* currentFrame = thread->m_currentFrame;
     const Variable argument = currentFrame->localVariables[1];
     VM->checkType(argument, VariableType_INT, thread);
@@ -51,3 +50,21 @@ JCALL void lib_java_lang_Thread_setPriority0(NATIVE_ARGS)
     field->data->data = argument.data;
 }
 
+JCALL void lib_java_lang_Thread_isAlive(NATIVE_ARGS)
+{
+    const StackFrame* currentFrame = thread->m_currentFrame;
+    const Variable var = currentFrame->localVariables[0];
+    VM->checkType(var, VariableType_REFERENCE, thread);
+    const u4 objectReference = var.data;
+    const VMThread* vmThread =  VM->getVMThreadByObjectRef(objectReference);
+
+    bool alive = false;
+    if (vmThread != nullptr)
+    {
+        alive = vmThread->alive;
+    }
+
+    StackFrame* returnFrame = thread->getTopFrameNonNative();
+    returnFrame->pushInt(alive? 1 : 0);
+}
+
diff --git a/src/Library/java/lang/Thread.h b/src/Library/java/lang/Thread.h
@@ -4,4 +4,5 @@
 
 JCALL void lib_java_lang_Thread_registerNatives(NATIVE_ARGS);
 JCALL void lib_java_lang_Thread_currentThread(NATIVE_ARGS);
-JCALL void lib_java_lang_Thread_setPriority0(NATIVE_ARGS);
+JCALL void lib_java_lang_Thread_setPriority0(NATIVE_ARGS);
+JCALL void lib_java_lang_Thread_isAlive(NATIVE_ARGS);
diff --git a/src/VM/VM.h b/src/VM/VM.h
@@ -47,6 +47,15 @@ class VM {
     void shutdown();
     void executeLoop(VMThread* thread);
     static void checkType(Variable var, VariableType type, VMThread *thread);
+    VMThread* getVMThreadByObjectRef(const u4 objectReference)
+    {
+        if (m_mainThread.threadObject == objectReference)
+        {
+            return &m_mainThread;
+        }
+
+        return nullptr;
+    }
 private:
     inline static constexpr std::array<Instruction,110> m_instructions{{
         // Constants

diff --git a/src/VM/VMThread.h b/src/VM/VMThread.h
@@ -19,6 +19,7 @@ class VMThread
     std::string_view m_name;
     u4 threadObject{0};
     i1 priority{5};
+    bool alive{false};
 
     explicit VMThread(const std::string_view name, const size_t frameSize) noexcept
         : m_stack(frameSize), m_name(name)