<div>Thanks Will for the new change. I have a few comments that I'd like you to take into account before moving forward.</div><div><br></div>General comment: Please also update all places where we check for isVMClassLoader (Jnjvm.cpp and JavaAOTCompiler.cpp) to also check for isVMStaticInstance.<br>
<br><div class="gmail_quote">On Thu, Nov 3, 2011 at 3:19 PM, Will Dietz <span dir="ltr"><<a href="mailto:wdietz2@illinois.edu" target="_blank">wdietz2@illinois.edu</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">Inlined below.<br>
<br>
Added a special class "VMStaticInstance" per our previous discussions.<br>
<br>
~Will<br>
<br>
>From f2d553af8173b3615d06b059d5f70a35d5c02fa6 Mon Sep 17 00:00:00 2001<br>
From: Will Dietz <<a href="mailto:w@wdtz.org" target="_blank">w@wdtz.org</a>><br>
Date: Fri, 14 Oct 2011 06:07:15 -0500<br>
Subject: [PATCH 02/17] Implement a number of Java.sun.misc.Unsafe.* methods.<br>
<br>
Of particular interest is the addition of VMStaticInstance, used to<br>
enable us to return a reference to a static instance, even though a<br>
static instance isn't a heap object (and prevents the underlying<br>
static instance from being GC'd while this reference is live).<br>
<br>
This is required for us to support staticFieldBase/staticFieldOffset.<br>
---<br>
lib/J3/ClassLib/Classpath.inc | 195 +++++++++++++++++++++++++++++++++++-<br>
lib/J3/ClassLib/VMStaticInstance.h | 81 +++++++++++++++<br>
lib/J3/VMCore/Makefile | 2 +-<br>
lib/J3/VMCore/VirtualTables.cpp | 11 ++-<br>
4 files changed, 285 insertions(+), 4 deletions(-)<br>
create mode 100644 lib/J3/ClassLib/VMStaticInstance.h<br>
<br>
diff --git a/lib/J3/ClassLib/Classpath.inc b/lib/J3/ClassLib/Classpath.inc<br>
index ccb9607..27fcb45 100644<br>
--- a/lib/J3/ClassLib/Classpath.inc<br>
+++ b/lib/J3/ClassLib/Classpath.inc<br>
@@ -15,12 +15,23 @@<br>
#include "JavaThread.h"<br>
#include "JavaUpcalls.h"<br>
#include "Jnjvm.h"<br>
+#include "Reader.h"<br>
+#include "VMStaticInstance.h"<br>
<br>
<br>
using namespace j3;<br>
<br>
extern "C" {<br>
<br>
+// Convert a 'base' JavaObject to its pointer representation.<br>
+// Handles our special VMStaticInstance wrapper.<br>
+static inline uint8 *baseToPtr(JavaObject *base) {<br>
+ if (VMStaticInstance::isVMStaticInstance(base))<br>
+ return (uint8*)((VMStaticInstance*)base)->getStaticInstance();<br>
+ else<br>
+ return (uint8*)base;<br>
+}<br>
+<br>
// Define hasClassInitializer because of a buggy implementation in Classpath.<br>
JNIEXPORT bool JNICALL Java_java_io_VMObjectStreamClass_hasClassInitializer(<br>
#ifdef NATIVE_JNI<br>
@@ -359,6 +370,186 @@ JavaObject* unsafe, JavaObject* obj, jlong<br>
offset, JavaObject* value) {<br>
mvm::Collector::objectReferenceWriteBarrier((gc*)obj, (gc**)ptr, (gc*)value);<br>
}<br>
<br>
+JNIEXPORT jlong JNICALL Java_sun_misc_Unsafe_allocateMemory(<br>
+JavaObject* unsafe, jlong size) {<br>
+ // TODO: Invalid size/OOM/etc handling!<br>
+ jlong res = 0;<br>
+ BEGIN_NATIVE_EXCEPTION(0)<br>
+ res = (jlong)malloc(size);<br>
+ END_NATIVE_EXCEPTION<br>
+ return res;<br>
+}<br>
+<br>
+JNIEXPORT void JNICALL Java_sun_misc_Unsafe_freeMemory(<br>
+JavaObject* unsafe, jlong ptr) {<br>
+ // TODO: Exception handling...<br>
+ BEGIN_NATIVE_EXCEPTION(0)<br>
+ free((void*)ptr);<br>
+ END_NATIVE_EXCEPTION<br>
+}<br>
+<br>
+JNIEXPORT void JNICALL Java_sun_misc_Unsafe_putLong__JJ(<br>
+JavaObject* unsafe, jlong ptr, jlong value) {<br>
+ BEGIN_NATIVE_EXCEPTION(0)<br>
+ *(jlong*)ptr = value;<br>
+ END_NATIVE_EXCEPTION<br>
+}<br>
+<br>
+JNIEXPORT jbyte JNICALL Java_sun_misc_Unsafe_getByte__J(<br>
+JavaObject* unsafe, jlong ptr) {<br>
+ jbyte res = 0;<br>
+ BEGIN_NATIVE_EXCEPTION(0)<br>
+ res = *(jbyte*)ptr;<br>
+ END_NATIVE_EXCEPTION<br>
+<br>
+ return res;<br>
+}<br>
+<br>
+JNIEXPORT void JNICALL Java_sun_misc_Unsafe_ensureClassInitialized(<br>
+JavaObject* unsafe, JavaObject* clazz) {<br>
+ llvm_gcroot(unsafe, 0);<br>
+ llvm_gcroot(clazz, 0);<br>
+ BEGIN_NATIVE_EXCEPTION(0)<br>
+<br>
+ Jnjvm* vm = JavaThread::get()->getJVM();<br>
+<br>
+ CommonClass * cl = JavaObject::getClass(clazz);<br>
+ assert(cl && cl->isClass());<br></blockquote><div><br></div><div>You should add a cl->resolveClass(), because a java.lang.Class can be created before the class is actually resolved.</div><div><br></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
+ cl->asClass()->initialiseClass(vm);<br>
+<br>
+ END_NATIVE_EXCEPTION;<br>
+}<br>
+<br>
+JNIEXPORT jlong JNICALL Java_sun_misc_Unsafe_staticFieldOffset(<br>
+JavaObject* unsafe, JavaObjectField* _field) {<br>
+ llvm_gcroot(unsafe, 0);<br>
+ llvm_gcroot(_field, 0);<br>
+<br>
+ jlong res = 0;<br>
+ BEGIN_NATIVE_EXCEPTION(0)<br>
+<br>
+ JavaField * field = JavaObjectField::getInternalField(_field);<br>
+ assert(field);<br>
+<br>
+ res = field->ptrOffset;<br>
+<br>
+ END_NATIVE_EXCEPTION;<br>
+<br>
+ return res;<br>
+}<br>
+<br>
+JNIEXPORT JavaObject* JNICALL Java_sun_misc_Unsafe_staticFieldBase(<br>
+JavaObject* unsafe, JavaObjectField* _field) {<br>
+ llvm_gcroot(unsafe, 0);<br>
+ llvm_gcroot(_field, 0);<br>
+ JavaObject* res = 0;<br></blockquote><div><br></div><div>Add a llvm_gcroot(res, 0);</div><div> </div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
+ BEGIN_NATIVE_EXCEPTION(0)<br>
+<br>
+ JavaField * field = JavaObjectField::getInternalField(_field);<br>
+ assert(field);<br>
+ field->classDef->initialiseClass(JavaThread::get()->getJVM());<br>
+<br>
+ void * staticInstance = field->classDef->getStaticInstance();<br>
+ JnjvmClassLoader * JCL = field->classDef->classLoader;<br>
+<br>
+ res = VMStaticInstance::allocate(JCL, staticInstance);<br>
+<br>
+ END_NATIVE_EXCEPTION;<br>
+<br>
+ return res;<br>
+}<br>
+<br>
+JNIEXPORT JavaObject* JNICALL Java_sun_misc_Unsafe_getObjectVolatile(<br>
+JavaObject* unsafe, JavaObject* base, jlong offset) {<br>
+ JavaObject * res = 0;<br>
+ llvm_gcroot(unsafe, 0);<br>
+ llvm_gcroot(base, 0);<br>
+ llvm_gcroot(res, 0);<br>
+<br>
+ BEGIN_NATIVE_EXCEPTION(0)<br>
+ JavaObject** ptr = (JavaObject**) (baseToPtr(base) + offset);<br>
+ res = *ptr;<br>
+ END_NATIVE_EXCEPTION;<br>
+<br>
+ return res;<br>
+}<br>
+<br>
+JNIEXPORT jlong JNICALL Java_sun_misc_Unsafe_arrayBaseOffset(<br>
+JavaObject* unsafe, JavaObject* clazz) {<br>
+ // TODO: Implement me<br></blockquote><div><br></div><div>Change to UNIMPLEMENTED() ?</div><div> </div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
+ return 0;<br>
+}<br>
+<br>
+JNIEXPORT jlong JNICALL Java_sun_misc_Unsafe_arrayIndexScale(<br>
+#ifdef NATIVE_JNI<br>
+JNIEnv *env,<br>
+#endif<br>
+JavaObject* unsafe, JavaObject* clazz) {<br>
+ // TODO: Implement me<br></blockquote><div><br></div><div>Change to UNIMPLEMENTED()?</div><div> </div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
+ return 0;<br>
+}<br>
+<br>
+JNIEXPORT JavaObject* JNICALL<br>
Java_sun_misc_Unsafe_defineClass__Ljava_lang_String_2_3BIILjava_lang_ClassLoader_2Ljava_security_ProtectionDomain_2(<br>
+JavaObject* unsafe, JavaString *name, ArrayObject * bytesArr, jint<br>
off, jint len, JavaObject * loader, JavaObject * pd) {<br>
+ JavaObject* res = 0;<br>
+ llvm_gcroot(res, 0);<br>
+ llvm_gcroot(unsafe, 0);<br>
+ llvm_gcroot(name, 0);<br>
+ llvm_gcroot(bytesArr, 0);<br>
+ llvm_gcroot(loader, 0);<br>
+ llvm_gcroot(pd, 0);<br>
+ BEGIN_NATIVE_EXCEPTION(0)<br>
+<br>
+ Jnjvm* vm = JavaThread::get()->getJVM();<br>
+ JnjvmClassLoader* JCL = NULL;<br>
+ JCL = JnjvmClassLoader::getJnjvmLoaderFromJavaObject(loader, vm);<br>
+<br>
+ jint last = off + len;<br>
+ if (last < bytesArr->size) {<br>
+ assert(0 && "What exception to throw here?");<br>
+ }<br>
+ ClassBytes * bytes = new (JCL->allocator, len) ClassBytes(len);<br>
+ memcpy(bytes->elements, JavaArray::getElements(bytesArr)+off, len);<br>
+ const UTF8* utfName = JavaString::javaToInternal(name, JCL->hashUTF8);<br>
+ UserClass *cl = JCL->constructClass(utfName, bytes);<br>
+<br>
+ if (cl) res = (JavaObject*)cl->getClassDelegatee(vm);<br>
+<br>
+ END_NATIVE_EXCEPTION;<br>
+<br>
+ return res;<br>
+}<br>
+<br>
+JNIEXPORT JavaObject* JNICALL<br>
Java_sun_misc_Unsafe_allocateInstance__Ljava_lang_Class_2(<br>
+JavaObject* unsafe, JavaObjectClass * clazz) {<br>
+ JavaObject* res = 0;<br>
+ llvm_gcroot(unsafe, 0);<br>
+ llvm_gcroot(clazz, 0);<br>
+ llvm_gcroot(res, 0);<br>
+<br>
+ BEGIN_NATIVE_EXCEPTION(0)<br>
+<br>
+ JavaThread* th = JavaThread::get();<br>
+ Jnjvm* vm = th->getJVM();<br>
+<br>
+ UserCommonClass* cl = UserCommonClass::resolvedImplClass(vm, clazz, true);<br>
+ if (cl->isClass())<br>
+ res = cl->asClass()->doNew(vm);<br>
+<br>
+ END_NATIVE_EXCEPTION;<br>
+<br>
+ return res;<br>
+}<br>
+<br>
+<br>
+JNIEXPORT void JNICALL Java_sun_misc_Unsafe_throwException(<br>
+JavaObject* unsafe, JavaObject * obj) {<br>
+ llvm_gcroot(unsafe, 0);<br>
+ llvm_gcroot(obj, 0);<br>
+<br>
+ JavaThread::get()->pendingException = obj;<br></blockquote><div><br></div><div>This should be JavaThread::get()->throwException(obj) (with my latest changes)</div><div> </div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
+}<br>
+<br>
JNIEXPORT void JNICALL Java_sun_misc_Unsafe_registerNatives(JavaObject*) {<br>
// Nothing<br>
}<br>
@@ -369,7 +560,7 @@ JNIEXPORT jtype JNICALL Java_sun_misc_Unsafe_get<br>
## Type ## __Ljava_lang_Object_<br>
JavaObject* unsafe, JavaObject* base, jlong offset) { \<br>
jtype res = 0; \<br>
BEGIN_NATIVE_EXCEPTION(0) \<br>
- jtype* ptr = (jtype*) (((uint8 *) base) + offset); \<br>
+ jtype* ptr = (jtype*) (baseToPtr(base) + offset); \<br>
res = *ptr; \<br>
END_NATIVE_EXCEPTION \<br>
\<br>
@@ -379,7 +570,7 @@ JavaObject* unsafe, JavaObject* base, jlong offset) { \<br>
JNIEXPORT void JNICALL Java_sun_misc_Unsafe_put ## Type ##<br>
__Ljava_lang_Object_2J ## shorttype( \<br>
JavaObject* unsafe, JavaObject* base, jlong offset, jtype val) { \<br>
BEGIN_NATIVE_EXCEPTION(0) \<br>
- jtype* ptr = (jtype*) (((uint8 *) base) + offset); \<br>
+ jtype* ptr = (jtype*) (baseToPtr(base) + offset); \<br>
*ptr = val; \<br>
END_NATIVE_EXCEPTION \<br>
}<br>
diff --git a/lib/J3/ClassLib/VMStaticInstance.h<br>
b/lib/J3/ClassLib/VMStaticInstance.h<br>
new file mode 100644<br>
index 0000000..9f62062<br>
--- /dev/null<br>
+++ b/lib/J3/ClassLib/VMStaticInstance.h<br>
@@ -0,0 +1,81 @@<br>
+//===-------- VMStaticInstance.h - Java wrapper for a static<br>
instance------===//<br>
+//<br>
+// The VMKit project<br>
+//<br>
+// This file is distributed under the University of Illinois Open Source<br>
+// License. See LICENSE.TXT for details.<br>
+//<br>
+//===----------------------------------------------------------------------===//<br>
+<br>
+#ifndef JNJVM_VMSTATICINSTANCE_H<br>
+#define JNJVM_VMSTATICINSTANCE_H<br>
+<br>
+#include "JavaObject.h"<br>
+#include "JnjvmClassLoader.h"<br>
+<br>
+namespace j3 {<br>
+<br>
+/// VMStaticInstance - Wraps a staticInstance, tracing to the creating<br>
+/// ClassLoader to ensure the staticInstance and it's Class don't get<br>
+/// improperly GC'd.<br>
+/// Largely inspired by VMClassLoader.<br>
+///<br>
+class VMStaticInstance : public JavaObject {<br>
+private:<br>
+ /// JCL - The classloader that created this static instance's class<br>
+ ///<br>
+ JnjvmClassLoader* JCL;<br>
+<br>
+ /// staticInstance - The static instance wrapped by this object<br>
+ ///<br>
+ void * staticInstance;<br></blockquote><div><br></div><div>Could you just have one field instead, that contains the Class?</div><div> </div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
+<br>
+public:<br>
+<br>
+ static VMStaticInstance* allocate(JnjvmClassLoader * JCL, void *<br>
staticInstance) {<br>
+ VMStaticInstance* res = 0;<br>
+ llvm_gcroot(res, 0);<br>
+ res = (VMStaticInstance*)gc::operator new(sizeof(VMStaticInstance), &VT);<br>
+ res->staticInstance = staticInstance;<br>
+ res->JCL = JCL;<br>
+ return res;<br>
+ }<br>
+<br>
+ /// VT - The VirtualTable for this GC-class.<br>
+ ///<br>
+ static VirtualTable VT;<br>
+<br>
+ /// Is the object a VMStaticInstance object?<br>
+ ///<br>
+ static bool isVMStaticInstance(JavaObject* obj) {<br>
+ llvm_gcroot(obj, 0);<br>
+ return obj->getVirtualTable() == &VT;<br>
+ }<br>
+<br>
+ /// ~VMStaticInstance - Nothing. Placeholder method<br>
+ /// to give the VirtualTable.<br>
+ ///<br>
+ static void staticDestructor(VMStaticInstance* obj) {<br>
+ llvm_gcroot(obj, 0);<br>
+ // Nothing to do here<br>
+ }<br>
+<br>
+ /// staticTracer - Trace the classloader that created<br>
+ /// the underlying staticInstance<br>
+ ///<br>
+ static void staticTracer(VMStaticInstance* obj, word_t closure) {<br>
+ llvm_gcroot(obj, 0);<br>
+ if (obj->JCL != NULL) obj->JCL->tracer(closure);<br>
+ }<br>
+<br>
+ /// getStaticInstance - Get the static instance contained in this object<br>
+ ///<br>
+ void * getStaticInstance() {<br>
+ return staticInstance;<br>
+ }<br>
+<br>
+};<br>
+<br>
+}<br>
+<br>
+#endif // JNJVM_VMSTATICINSTANCE_H<br>
diff --git a/lib/J3/VMCore/Makefile b/lib/J3/VMCore/Makefile<br>
index fc07061..987919a 100644<br>
--- a/lib/J3/VMCore/Makefile<br>
+++ b/lib/J3/VMCore/Makefile<br>
@@ -14,4 +14,4 @@ MODULE_WITH_GC = J3<br>
<br>
include $(LEVEL)/Makefile.common<br>
<br>
-CXX.Flags += -I$(PROJ_OBJ_DIR)/../ClassLib<br>
-I$(PROJ_OBJ_DIR)/../LLVMRuntime<br>
-I$(PROJ_SRC_DIR)/../ClassLib/$(CLASSPATH_DIR)<br>
-I$(PROJ_SRC_DIR)/../../../include/j3<br>
+CXX.Flags += -I$(PROJ_OBJ_DIR)/../ClassLib<br>
-I$(PROJ_OBJ_DIR)/../LLVMRuntime<br>
-I$(PROJ_SRC_DIR)/../ClassLib/$(CLASSPATH_DIR)<br>
-I$(PROJ_SRC_DIR)/../../../include/j3 -I$(PROJ_SRC_DIR)/../ClassLib<br>
diff --git a/lib/J3/VMCore/VirtualTables.cpp b/lib/J3/VMCore/VirtualTables.cpp<br>
index 68774b7..6b3b999 100644<br>
--- a/lib/J3/VMCore/VirtualTables.cpp<br>
+++ b/lib/J3/VMCore/VirtualTables.cpp<br>
@@ -32,6 +32,7 @@<br>
#include "JnjvmClassLoader.h"<br>
#include "LockedMap.h"<br>
#include "ReferenceQueue.h"<br>
+#include "VMStaticInstance.h"<br>
#include "Zip.h"<br>
<br>
using namespace j3;<br>
@@ -44,7 +45,7 @@ using namespace j3;<br>
// Having many GC classes gives more work to the GC for the scanning phase<br>
// and for the relocation phase (for copying collectors).<br>
//<br>
-// In J3, there is only one internal gc object, the class loader.<br>
+// In J3, there is only one primary internal gc object, the class loader.<br>
// We decided that this was the best solution because<br>
// otherwise it would involve hacks on the java.lang.Classloader class.<br>
// Therefore, we create a new GC class with a finalize method that will<br>
@@ -52,12 +53,20 @@ using namespace j3;<br>
// not reachable anymore. This also relies on the java.lang.Classloader class<br>
// referencing an object of type VMClassLoader (this is the case in GNU<br>
// Classpath with the vmdata field).<br>
+// In addition, to handle support for sun.misc.Unsafe, we have a similar<br>
+// second clsas VMStaticInstance that wraps static instances for use<br>
+// in staticFieldBase and traces the owning ClassLoader to make sure<br>
+// the underlying instance and class don't get GC'd improperly.<br>
//===----------------------------------------------------------------------===//<br>
<br>
VirtualTable VMClassLoader::VT((word_t)VMClassLoader::staticDestructor,<br>
(word_t)VMClassLoader::staticDestructor,<br>
(word_t)VMClassLoader::staticTracer);<br>
<br>
+VirtualTable VMStaticInstance::VT((word_t)VMStaticInstance::staticDestructor,<br>
+ (word_t)VMStaticInstance::staticDestructor,<br>
+ (word_t)VMStaticInstance::staticTracer);<br>
+<br>
//===----------------------------------------------------------------------===//<br>
// Trace methods for Java objects. There are four types of objects:<br>
// (1) java.lang.Object and primitive arrays: no need to trace anything.<br>
<span><font color="#888888">--<br>
1.7.5.1<br>
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</font></span></blockquote></div><br>