more JNI work

classpath/Hello.java

@@ -0,0 +1,5 @@
+public class Hello {
+  public static void main(String[] args) {
+    System.out.println("hello, world!");
+  }
+}

classpath/java/lang/System.cpp

@@ -0,0 +1,13 @@
+#include "stdio.h"
+#include "jni.h"
+
+extern "C" JNIEXPORT void JNICALL
+Java_java_lang_System_Output_println(JNIEnv* e, jobject, jstring s)
+{
+  jboolean isCopy;
+  const char* chars = e->GetStringUTFChars(s, &isCopy);
+  if (chars) {
+    printf("%s", chars);
+  }
+  e->ReleaseStringUTFChars(s, chars);
+}

classpath/java/lang/System.java

@@ -0,0 +1,15 @@
+package java.lang;
+
+public abstract class System {
+  public static final Output out = new Output();
+
+  static {
+    loadLibrary("natives");
+  }
+
+  public static native void loadLibrary(String name);
+
+  public static class Output {
+    public native void println(String s);
+  }
+}

makefile

@@ -2,7 +2,7 @@
 
 bld = build
 src = src
-inp = input
+classpath = classpath
 
 cxx = g++
 cc = gcc
@@ -22,7 +22,7 @@ thread-lflags = -lpthread
 
 cflags = $(warnings) -fPIC -fno-rtti -fno-exceptions -fvisibility=hidden \
 	-I$(src) -I$(bld) $(thread-cflags)
-lflags = $(thread-lflags)
+lflags = $(thread-lflags) -ldl
 test-cflags = -DDEBUG_MEMORY
 stress-cflags = -DDEBUG_MEMORY -DDEBUG_MEMORY_MAJOR
 
@@ -32,6 +32,13 @@ stdcpp-sources = $(src)/stdc++.cpp
 stdcpp-objects = $(call cpp-objects,$(stdcpp-sources),$(src))
 stdcpp-cflags = $(fast) $(cflags)
 
+jni-sources = $(classpath)/java/lang/System.cpp
+jni-objects = $(call cpp-objects,$(jni-sources),$(classpath))
+jni-cflags = -I/usr/lib/jvm/java-6-sun-1.6.0.00/include \
+	-I/usr/lib/jvm/java-6-sun-1.6.0.00/include/linux \
+	$(cflags)
+jni-library = $(bld)/libnatives.so
+
 generated-code = \
 	$(bld)/type-enums.cpp \
 	$(bld)/type-declarations.cpp \
@@ -75,11 +82,10 @@ fast-objects = $(patsubst $(bld)/%,$(bld)/fast-%,$(interpreter-objects))
 fast-executable = $(bld)/fast-vm
 fast-cflags = $(fast) $(cflags)
 
-input = $(bld)/classes/Test.class
+input = $(bld)/classes/Hello.class
 input-depends = \
-	$(bld)/classes/java/lang/Object.class \
-	$(bld)/classes/java/lang/Class.class \
-	$(bld)/classes/vm/VM.class
+	$(bld)/classes/java/lang/System.class \
+	$(jni-library)
 
 gen-run-arg = $(shell echo $(1) | sed -e 's:$(bld)/classes/\(.*\)\.class:\1:')
 args = -cp $(bld)/classes -hs 67108864 $(call gen-run-arg,$(input))
@@ -142,10 +148,11 @@ $(generated-code): %.cpp: $(src)/types.def $(generator-executable)
 $(bld)/type-generator.o: \
 	$(generator-headers)
 
-$(bld)/classes/%.class: $(inp)/%.java
+$(bld)/classes/%.class: $(classpath)/%.java
 	@echo "compiling $(@)"
 	@mkdir -p $(dir $(@))
-	$(javac) -bootclasspath $(inp) -classpath $(inp) -d $(bld)/classes $(<)
+	$(javac) -bootclasspath $(classpath) -classpath $(classpath) \
+		-d $(bld)/classes $(<)
 
 $(stdcpp-objects): $(bld)/%.o: $(src)/%.cpp
 	@echo "compiling $(@)"
@@ -177,6 +184,15 @@ $(fast-objects): $(bld)/fast-%.o: $(src)/%.cpp $(interpreter-depends)
 	@mkdir -p $(dir $(@))
 	$(cxx) $(fast-cflags) -c $(<) -o $(@)
 
+$(jni-objects): $(bld)/%.o: $(classpath)/%.cpp
+	@echo "compiling $(@)"
+	@mkdir -p $(dir $(@))
+	$(cxx) $(jni-cflags) -c $(<) -o $(@)	
+
+$(jni-library): $(jni-objects)
+	@echo "linking $(@)"
+	$(cc) $(lflags) -shared $(^) -o $(@)
+
 $(executable): $(interpreter-objects) $(stdcpp-objects)
 	@echo "linking $(@)"
 	$(cc) $(lflags) $(^) -o $(@)

src/main.cpp

@@ -66,6 +66,8 @@ class System: public vm::System {
   }
 
   virtual void* tryAllocate(unsigned size) {
+    // todo: synchronize access
+
     if (Verbose) {
       fprintf(stderr, "try %d; count: %d; limit: %d\n",
               size, count, limit);
@@ -85,6 +87,8 @@ class System: public vm::System {
   }
 
   virtual void free(const void* p) {
+    // todo: synchronize access
+
     if (p) {
       const uintptr_t* up = static_cast<const uintptr_t*>(p) - 1;
       if (count < *up) {
@@ -110,14 +114,19 @@ class System: public vm::System {
     return 0;
   }
 
-  virtual uint64_t call(void* function, unsigned argumentCount,
-                        uint32_t* argumentTable, uint8_t* argumentSizeTable,
-                        unsigned returnSize)
+  virtual uint64_t call(void* ,//function,
+                        unsigned ,//argumentCount,
+                        uint32_t* ,//argumentTable,
+                        uint8_t* ,//argumentSizeTable,
+                        unsigned )//returnSize)
   {
-    
+    ::abort();
   }
 
-  virtual Status load(Library** lib, const char* name, Library* next) {
+  virtual Status load(vm::System::Library** lib,
+                      const char* name,
+                      vm::System::Library* next)
+  {
     void* p = dlopen(name, RTLD_LAZY);
     if (p) {
       *lib = new (vm::System::allocate(sizeof(Library)))

src/system.h

@@ -44,8 +44,8 @@ class System {
   virtual Status make(Monitor**) = 0;
   virtual uint64_t call(void* function, unsigned argumentCount,
                         uint32_t* argumentTable, uint8_t* argumentSizeTable,
-                        unsigned returnSize);
-  virtual Status load(Library**, const char* name, Library* next);
+                        unsigned returnSize) = 0;
+  virtual Status load(Library**, const char* name, Library* next) = 0;
   virtual void abort() = 0;
 
   void* allocate(unsigned size) {

src/vm.cpp

@@ -4,6 +4,7 @@
 #include "class_finder.h"
 #include "stream.h"
 #include "constants.h"
+#include "jni.h"
 #include "vm.h"
 
 #define PROTECT(thread, name)                                   \
@@ -30,7 +31,6 @@ object& arrayBodyUnsafe(Thread*, object, unsigned);
 void set(Thread*, object&, object);
 object makeString(Thread*, const char*, ...);
 object makeByteArray(Thread*, const char*, ...);
-unsigned objectSize(Thread* t, object o);
 
 object&
 objectClass(object o)
@@ -152,10 +152,11 @@ class Thread {
   unsigned ip;
   unsigned sp;
   unsigned heapIndex;
-  object stack[StackSizeInWords];
-  object heap[HeapSizeInWords];
   Protector* protector;
   Chain* chain;
+  object stack[StackSizeInWords];
+  object heap[HeapSizeInWords];
+  JNIEnv jniEnv;
 };
 
 #include "type-declarations.cpp"
@@ -458,77 +459,6 @@ top(Thread* t)
   return t->stack[t->sp - 1];
 }
 
-int32_t
-builtinToString(Thread* t, int32_t this_)
-{
-  object o = t->stack[this_ - 1];
-  object s = makeString(t, "%s@%p",
-                        &byteArrayBody(t, className(t, objectClass(o)), 0),
-                        o);
-  pushSafe(t, s);
-  return t->sp;
-}
-
-Thread::Thread(Machine* m):
-  vm(m),
-  next(0),
-  child(0),
-  state(NoState),
-  thread(0),
-  frame(0),
-  code(0),
-  exception(0),
-  ip(0),
-  sp(0),
-  heapIndex(0),
-  protector(0),
-  chain(0)
-{
-  if (m->rootThread == 0) {
-    m->rootThread = this;
-    m->unsafe = true;
-
-    Thread* t = this;
-
-#include "type-initializations.cpp"
-
-    object arrayClass = arrayBody(t, t->vm->types, Machine::ArrayType);
-    set(t, objectClass(t->vm->types), arrayClass);
-
-    object classClass = arrayBody(t, m->types, Machine::ClassType);
-    set(t, objectClass(classClass), classClass);
-
-    object intArrayClass = arrayBody(t, m->types, Machine::IntArrayType);
-    set(t, objectClass(intArrayClass), classClass);
-
-    m->unsafe = false;
-
-    m->bootstrapClassMap = makeHashMap(this, 0, 0);
-
-#include "type-java-initializations.cpp"
-
-    m->classMap = makeHashMap(this, 0, 0);
-    m->builtinMap = makeHashMap(this, 0, 0);
-
-    struct {
-      const char* key;
-      void* value;
-    } builtins[] = {
-      { "Java_java_lang_Object_toString",
-        reinterpret_cast<void*>(builtinToString) },
-      { 0, 0 }
-    };
-
-    for (unsigned i = 0; builtins[i].key; ++i) {
-      object key = makeByteArray(t, builtins[i].key);
-      PROTECT(t, key);
-      object value = makePointer(t, builtins[i].value);
-
-      hashMapInsert(t, m->builtinMap, key, value, byteArrayHash);
-    }
-  }
-}
-
 void
 Thread::dispose()
 {
@@ -864,6 +794,22 @@ make(Thread* t, object class_)
   return instance;
 }
 
+unsigned
+objectSize(Thread* t, object o)
+{
+  object class_ = objectClass(o);
+
+  unsigned n = divide(classFixedSize(t, class_), BytesPerWord);
+
+  if (classArrayElementSize(t, class_)) {
+    n += divide(classArrayElementSize(t, class_)
+                * cast<uint32_t>(o, classFixedSize(t, class_) - 4),
+                BytesPerWord);
+  }
+
+  return n;
+}
+
 object
 makeByteArray(Thread* t, const char* format, va_list a)
 {
@@ -915,6 +861,14 @@ makeTrace(Thread* t)
   return trace;
 }
 
+object
+makeRuntimeException(Thread* t, object message)
+{
+  PROTECT(t, message);
+  object trace = makeTrace(t);
+  return makeClassCastException(t, message, trace, 0);
+}
+
 object
 makeArrayIndexOutOfBoundsException(Thread* t, object message)
 {
@@ -1891,7 +1845,7 @@ updateBootstrapClass(Thread* t, object bootstrapClass, object class_)
 
   enter(t, Thread::ExclusiveState);
 
-  memcpy(bootstrapClass, class_, objectSize(t, class_));
+  memcpy(bootstrapClass, class_, objectSize(t, class_) * BytesPerWord);
 
   enter(t, Thread::ActiveState);
 }
@@ -2013,12 +1967,12 @@ makeNativeMethodData(Thread* t, object method, void* function, bool builtin)
                                      methodParameterCount(t, method),
                                      false);
         
-  unsigned argumentTableSize = sizeof(void*) / 4;
+  unsigned argumentTableSize = BytesPerWord / 4;
   unsigned index = 0;
 
   if ((methodFlags(t, method) & ACC_STATIC) == 0) {
     nativeMethodDataParameterCodes(t, data, index++) = ObjectField;
-    argumentTableSize += 1;    
+    argumentTableSize += BytesPerWord / 4;
   }
 
   const char* s = reinterpret_cast<const char*>
@@ -2030,13 +1984,13 @@ makeNativeMethodData(Thread* t, object method, void* function, bool builtin)
 
     switch (*s) {
     case 'L':
-      argumentTableSize += 1;
+      argumentTableSize += BytesPerWord / 4;
       while (*s and *s != ';') ++ s;
       ++ s;
       break;
 
     case '[':
-      argumentTableSize += 1;
+      argumentTableSize += BytesPerWord / 4;
       while (*s == '[') ++ s;
       break;
       
@@ -2108,35 +2062,29 @@ invokeNative(Thread* t, object method)
   uint8_t sizes[parameterCount + 1];
   unsigned offset = 0;
 
-  switch (sizeof(uintptr_t)) {
-  case 4: {
-    sizes[0] = 4;
-    args[offset++] = reinterpret_cast<uintptr_t>(t);
-  } break;
-
-  case 8: {
-    sizes[0] = 8;
-    uint64_t v = reinterpret_cast<uint64_t>(t);
-    args[offset++] = static_cast<uint32_t>(v >> 32);
-    args[offset++] = static_cast<uint32_t>(v & 0xFFFFFFFF);
-  } break;
-    
-  default:
-    abort(t);
-  }
+  sizes[0] = BytesPerWord;
+  JNIEnv* e = &(t->jniEnv);
+  memcpy(args + offset, &e, BytesPerWord);
+  offset += BytesPerWord / 4;
 
   for (unsigned i = 0; i < parameterCount; ++i) {
     unsigned code = nativeMethodDataParameterCodes(t, data, i);
 
     if (code == ObjectField) {
-      sizes[i + 1] = 4;
-      args[offset++] = t->sp + i + 1;
+      sizes[i + 1] = BytesPerWord;
+      unsigned position = (t->sp - parameterCount) + i;
+      if (t->stack[position]) {
+        memcpy(args + offset, t->stack + position, BytesPerWord);
+      } else {
+        memset(args + offset, 0, BytesPerWord);
+      }
+      offset += BytesPerWord / 4;
     } else {
       sizes[i + 1] = primitiveSize(t, code);
       uint64_t v = primitiveValue(t, code, t->stack[t->sp + i]);
       if (sizes[i + 1] == 8) {
-        args[offset++] = static_cast<uint32_t>(v >> 32);
-        args[offset++] = static_cast<uint32_t>(v & 0xFFFFFFFF);
+        memcpy(args + offset, &v, 8);
+        offset += 2;
       } else {
         args[offset++] = v;
       }
@@ -2167,12 +2115,172 @@ invokeNative(Thread* t, object method)
   if (UNLIKELY(t->exception) or returnCode == VoidField) {
     return 0;
   } else if (returnCode == ObjectField) {
-    return (rv == 0 ? 0 : t->stack[rv - 1]);
+    return (rv == 0 ? 0 :
+            *reinterpret_cast<object*>(static_cast<uintptr_t>(rv)));
   } else {
     return makePrimitive(t, returnCode, rv);
   }
 }
 
+void
+builtinLoadLibrary(JNIEnv* e, jstring nameString)
+{
+  Thread* t = static_cast<Thread*>(e->reserved0);
+
+  if (LIKELY(nameString)) {
+    object n = *nameString;
+    char name[stringLength(t, n) + 1];
+    memcpy(name,
+           &byteArrayBody(t, stringBytes(t, n), stringOffset(t, n)),
+           stringLength(t, n));
+    name[stringLength(t, n)] = 0;
+
+    System::Library* lib;
+    if (LIKELY(t->vm->system->success
+               (t->vm->system->load(&lib, name, t->vm->libraries))))
+    {
+      t->vm->libraries = lib;
+    } else {
+      object message = makeString(t, "library not found: %s", name);
+      t->exception = makeRuntimeException(t, message);
+    }
+  } else {
+    t->exception = makeNullPointerException(t);
+  }
+}
+
+jstring
+builtinToString(JNIEnv* e, jobject this_)
+{
+  Thread* t = static_cast<Thread*>(e->reserved0);
+
+  object s = makeString
+    (t, "%s@%p",
+     &byteArrayBody(t, className(t, objectClass(*this_)), 0),
+     *this_);
+
+  pushSafe(t, s);
+  return t->stack + (t->sp - 1);
+}
+
+jsize
+GetStringUTFLength(JNIEnv* e, jstring s)
+{
+  Thread* t = static_cast<Thread*>(e->reserved0);
+  enter(t, Thread::ActiveState);
+
+  jsize length = 0;
+  if (LIKELY(s)) {
+    length = stringLength(t, *s);
+  } else {
+    t->exception = makeNullPointerException(t);
+  }
+
+  enter(t, Thread::IdleState);
+
+  return length;
+}
+
+const char*
+GetStringUTFChars(JNIEnv* e, jstring s, jboolean* isCopy)
+{
+  Thread* t = static_cast<Thread*>(e->reserved0);
+  enter(t, Thread::ActiveState);
+
+  char* chars = 0;
+  if (LIKELY(s)) {
+    chars = static_cast<char*>(t->vm->system->allocate(stringLength(t, *s)));
+
+    memcpy(chars,
+           &byteArrayBody(t, stringBytes(t, *s), stringOffset(t, *s)),
+           stringLength(t, *s));
+
+    chars[stringLength(t, *s)] = 0;
+  } else {
+    t->exception = makeNullPointerException(t);
+  }
+
+  enter(t, Thread::IdleState);
+
+  *isCopy = true;
+  return chars;
+}
+
+void
+ReleaseStringUTFChars(JNIEnv* e, jstring, const char* chars)
+{
+  Thread* t = static_cast<Thread*>(e->reserved0);
+  t->vm->system->free(chars);
+}
+
+Thread::Thread(Machine* m):
+  vm(m),
+  next(0),
+  child(0),
+  state(NoState),
+  thread(0),
+  frame(0),
+  code(0),
+  exception(0),
+  ip(0),
+  sp(0),
+  heapIndex(0),
+  protector(0),
+  chain(0)
+{
+  memset(&jniEnv, 0, sizeof(JNIEnv));
+  jniEnv.reserved0 = this;
+  jniEnv.GetStringUTFLength = GetStringUTFLength;
+  jniEnv.GetStringUTFChars = GetStringUTFChars;
+  jniEnv.ReleaseStringUTFChars = ReleaseStringUTFChars;
+
+  if (m->rootThread == 0) {
+    m->rootThread = this;
+    m->unsafe = true;
+
+    Thread* t = this;
+
+#include "type-initializations.cpp"
+
+    object arrayClass = arrayBody(t, t->vm->types, Machine::ArrayType);
+    set(t, objectClass(t->vm->types), arrayClass);
+
+    object classClass = arrayBody(t, m->types, Machine::ClassType);
+    set(t, objectClass(classClass), classClass);
+
+    object intArrayClass = arrayBody(t, m->types, Machine::IntArrayType);
+    set(t, objectClass(intArrayClass), classClass);
+
+    m->unsafe = false;
+
+    m->bootstrapClassMap = makeHashMap(this, 0, 0);
+
+#include "type-java-initializations.cpp"
+
+    m->classMap = makeHashMap(this, 0, 0);
+    m->builtinMap = makeHashMap(this, 0, 0);
+
+    struct {
+      const char* key;
+      void* value;
+    } builtins[] = {
+      { "Java_java_lang_Object_toString",
+        reinterpret_cast<void*>(builtinToString) },
+      { "Java_java_lang_System_load",
+        reinterpret_cast<void*>(builtinLoadLibrary) },
+      { 0, 0 }
+    };
+
+    for (unsigned i = 0; builtins[i].key; ++i) {
+      object key = makeByteArray(t, builtins[i].key);
+      PROTECT(t, key);
+      object value = makePointer(t, builtins[i].value);
+
+      hashMapInsert(t, m->builtinMap, key, value, byteArrayHash);
+    }
+  }
+}
+
 object
 run(Thread* t)
 {