VPKnownObject Constraints for JITServer

runtime/compiler/control/JITClientCompilationThread.cpp

@@ -586,6 +586,24 @@ handleServerMessage(JITServer::ClientStream *client, TR_J9VM *fe, JITServer::Mes
          client->write(response, fe->getObjectClassFromKnownObjectIndex(comp, idx));
          }
          break;
+      case MessageType::VM_getObjectClassFromKnownObjectIndexJLClass:
+         {
+         auto recv = client->getRecvData<TR::KnownObjectTable::Index>();
+         auto idx = std::get<0>(recv);
+         bool isJL;
+         client->write(response, fe->getObjectClassFromKnownObjectIndex(comp, idx, &isJL), isJL);
+         }
+         break;
+      case MessageType::VM_getObjectClassInfoFromObjectReferenceLocation:
+         {
+         auto recv = client->getRecvData<uintptr_t>();
+         uintptr_t objectReferenceLocation = std::get<0>(recv);
+         auto ci = fe->getObjectClassInfoFromObjectReferenceLocation(comp, objectReferenceLocation);
+         client->write(response,
+                       ci,
+                       knot->getPointerLocation(ci.knownObjectIndex));
+         }
+         break;
       case MessageType::VM_stackWalkerMaySkipFrames:
          {
          client->getRecvData<JITServer::Void>();

runtime/compiler/env/VMJ9.cpp

@@ -1213,13 +1213,61 @@ TR_J9VMBase::getObjectClassFromKnownObjectIndex(TR::Compilation *comp, TR::Known
    return clazz;
    }
 
+TR_OpaqueClassBlock *
+TR_J9VMBase::getObjectClassFromKnownObjectIndex(TR::Compilation *comp,
+                                                TR::KnownObjectTable::Index idx,
+                                                bool *isJavaLangClass)
+   {
+   TR::VMAccessCriticalSection vpKnownObjectCriticalSection(comp);
+
+   TR::KnownObjectTable *knot = comp->getKnownObjectTable();
+   if (!knot)
+      return NULL;
+
+   TR_OpaqueClassBlock *clazz = getObjectClass(knot->getPointer(idx));
+   TR_OpaqueClassBlock *jlClass = getClassClassPointer(clazz);
+   *isJavaLangClass = (clazz == jlClass);
+   if (*isJavaLangClass)
+      {
+      clazz = getClassFromJavaLangClass(knot->getPointer(idx));
+      }
+   return clazz;
+   }
 uintptr_t
 TR_J9VMBase::getStaticReferenceFieldAtAddress(uintptr_t fieldAddress)
    {
    TR_ASSERT(haveAccess(), "Must haveAccess in getStaticReferenceFieldAtAddress");
    return (uintptr_t)J9STATIC_OBJECT_LOAD(vmThread(), NULL, fieldAddress);
    }
 
+TR_J9VMBase::ObjectClassInfo
+TR_J9VMBase::getObjectClassInfoFromObjectReferenceLocation(TR::Compilation *comp,
+                                               uintptr_t objectReferenceLocation)
+   {
+   TR_J9VMBase::ObjectClassInfo ci = {};
+   TR::KnownObjectTable *knot = comp->getKnownObjectTable();
+   if (knot)
+      {
+      TR::VMAccessCriticalSection getObjectReferenceLocation(comp);
+      uintptr_t objectReference = getStaticReferenceFieldAtAddress
+         (objectReferenceLocation);
+      ci.clazz   = getObjectClass(objectReference);
+      ci.isString = isString(ci.clazz);
+      ci.jlClass = getClassClassPointer(ci.clazz);
+      ci.isFixedJavaLangClass = (ci.jlClass == ci.clazz);
+      if (ci.isFixedJavaLangClass)
+         {
+         // A FixedClass constraint means something different
+         // when the class happens to be java/lang/Class.
+         // Must add constraints pertaining to the class that
+         // the java/lang/Class object represents.
+         ci.clazz = getClassFromJavaLangClass(objectReference);
+         }
+      ci.knownObjectIndex = knot->getOrCreateIndex(objectReference);
+      }
+   return ci;
+   }
+
 uintptr_t
 TR_J9VMBase::getReferenceFieldAtAddress(uintptr_t fieldAddress)
    {

runtime/compiler/env/VMJ9.h

@@ -635,13 +635,28 @@ class TR_J9VMBase : public TR_FrontEnd
    virtual TR_OpaqueClassBlock *getObjectClass(uintptr_t objectPointer);
    virtual TR_OpaqueClassBlock *getObjectClassAt(uintptr_t objectAddress);
    virtual TR_OpaqueClassBlock *getObjectClassFromKnownObjectIndex(TR::Compilation *comp, TR::KnownObjectTable::Index idx);
+   virtual TR_OpaqueClassBlock *getObjectClassFromKnownObjectIndex(TR::Compilation *comp, TR::KnownObjectTable::Index idx, bool *isJavaLangClass);
    virtual uintptr_t           getReferenceFieldAt(uintptr_t objectPointer, uintptr_t offsetFromHeader);
    virtual uintptr_t           getVolatileReferenceFieldAt(uintptr_t objectPointer, uintptr_t offsetFromHeader);
    virtual uintptr_t           getReferenceFieldAtAddress(uintptr_t fieldAddress);
    virtual uintptr_t           getReferenceFieldAtAddress(void *fieldAddress){ return getReferenceFieldAtAddress((uintptr_t)fieldAddress); }
    virtual uintptr_t           getStaticReferenceFieldAtAddress(uintptr_t fieldAddress);
    virtual int32_t              getInt32FieldAt(uintptr_t objectPointer, uintptr_t fieldOffset);
 
+   /* Used to contain all information needed for getObjectClassInfoFromObjectReferenceLocation
+    * to create a VPKnownObject constraint.
+    */
+   struct ObjectClassInfo
+      {
+      TR_OpaqueClassBlock *clazz;
+      TR_OpaqueClassBlock *jlClass;
+      bool isFixedJavaLangClass;
+      bool isString;
+      TR::KnownObjectTable::Index knownObjectIndex;
+      };
+   virtual ObjectClassInfo getObjectClassInfoFromObjectReferenceLocation
+                                    (TR::Compilation *comp, uintptr_t objectReferenceLocation);
+
    int32_t getInt32Field(uintptr_t objectPointer, const char *fieldName)
       {
       return getInt32FieldAt(objectPointer, getInstanceFieldOffset(getObjectClass(objectPointer), fieldName, "I"));

runtime/compiler/env/VMJ9Server.cpp

@@ -937,12 +937,37 @@ TR_J9ServerVM::getObjectClassFromKnownObjectIndex(TR::Compilation *comp, TR::Kno
    return std::get<0>(stream->read<TR_OpaqueClassBlock *>());
    }
 
+TR_OpaqueClassBlock *
+TR_J9ServerVM::getObjectClassFromKnownObjectIndex(TR::Compilation *comp,
+                                                  TR::KnownObjectTable::Index idx,
+                                                  bool *isJavaLangClass)
+   {
+   JITServer::ServerStream *stream = _compInfoPT->getMethodBeingCompiled()->_stream;
+   stream->write(JITServer::MessageType::VM_getObjectClassFromKnownObjectIndexJLClass, idx);
+   auto recv = stream->read<TR_OpaqueClassBlock *, bool>();
+   *isJavaLangClass = std::get<1>(recv);
+   return std::get<0>(recv);
+   }
+
 uintptr_t
 TR_J9ServerVM::getStaticReferenceFieldAtAddress(uintptr_t fieldAddress)
    {
    TR_ASSERT_FATAL(false, "getStaticReferenceFieldAtAddress() should not be called by JITServer");
    }
 
+TR_J9VMBase::ObjectClassInfo
+TR_J9ServerVM::getObjectClassInfoFromObjectReferenceLocation(TR::Compilation *comp, uintptr_t objectReferenceLocation)
+   {
+   JITServer::ServerStream *stream = _compInfoPT->getMethodBeingCompiled()->_stream;
+   stream->write(JITServer::MessageType::VM_getObjectClassInfoFromObjectReferenceLocation,
+                 objectReferenceLocation);
+   auto recv = stream->read<TR_J9VMBase::ObjectClassInfo, uintptr_t *>();
+   TR_J9VMBase::ObjectClassInfo result = std::get<0>(recv);
+   uintptr_t *objectReferenceLocationClient = std::get<1>(recv);
+   comp->getKnownObjectTable()->updateKnownObjectTableAtServer(result.knownObjectIndex, objectReferenceLocationClient);
+   return result;
+   }
+
 bool
 TR_J9ServerVM::stackWalkerMaySkipFrames(TR_OpaqueMethodBlock *method, TR_OpaqueClassBlock *clazz)
    {

runtime/compiler/env/VMJ9Server.hpp

@@ -111,8 +111,12 @@ class TR_J9ServerVM: public TR_J9VM
    virtual TR_OpaqueClassBlock * getObjectClass(uintptr_t objectPointer) override;
    virtual TR_OpaqueClassBlock * getObjectClassAt(uintptr_t objectAddress) override;
    virtual TR_OpaqueClassBlock *getObjectClassFromKnownObjectIndex(TR::Compilation *comp, TR::KnownObjectTable::Index idx) override;
+   virtual TR_OpaqueClassBlock *getObjectClassFromKnownObjectIndex(TR::Compilation *comp, TR::KnownObjectTable::Index idx, bool *isJavaLangClass) override;
    virtual uintptr_t getStaticReferenceFieldAtAddress(uintptr_t fieldAddress) override;
 
+   virtual ObjectClassInfo getObjectClassInfoFromObjectReferenceLocation
+                              (TR::Compilation *comp, uintptr_t objectReferenceLocation) override;
+
    virtual bool stackWalkerMaySkipFrames(TR_OpaqueMethodBlock *method, TR_OpaqueClassBlock *clazz) override;
    virtual bool hasFinalFieldsInClass(TR_OpaqueClassBlock *clazz) override;
    virtual const char *sampleSignature(TR_OpaqueMethodBlock * aMethod, char *buf, int32_t bufLen, TR_Memory *memory) override;

runtime/compiler/net/CommunicationStream.hpp

@@ -128,7 +128,7 @@ class CommunicationStream
    // likely to lose an increment when merging/rebasing/etc.
    //
    static const uint8_t MAJOR_NUMBER = 1;
-   static const uint16_t MINOR_NUMBER = 74; // ID: Qi304qaThEQ4NoZZkw1O
+   static const uint16_t MINOR_NUMBER = 75; // ID: kzkyjklaOnYjEzzJyIl7
    static const uint8_t PATCH_NUMBER = 0;
    static uint32_t CONFIGURATION_FLAGS;
 

runtime/compiler/net/MessageTypes.cpp

@@ -118,6 +118,8 @@ const char *messageNames[] =
    "VM_getObjectClass",
    "VM_getObjectClassAt",
    "VM_getObjectClassFromKnownObjectIndex",
+   "VM_getObjectClassFromKnownObjectIndexJLClass",
+   "VM_getObjectClassInfoFromObjectReferenceLocation",
    "VM_stackWalkerMaySkipFrames",
    "VM_getStringUTF8Length",
    "VM_classInitIsFinished",

runtime/compiler/net/MessageTypes.hpp

@@ -127,6 +127,8 @@ enum MessageType : uint16_t
    VM_getObjectClass,
    VM_getObjectClassAt,
    VM_getObjectClassFromKnownObjectIndex,
+   VM_getObjectClassFromKnownObjectIndexJLClass,
+   VM_getObjectClassInfoFromObjectReferenceLocation,
    VM_stackWalkerMaySkipFrames,
    VM_getStringUTF8Length,
    VM_classInitIsFinished,