view src/share/vm/prims/unsafe.cpp @ 2346:e1162778c1c8

7009266: G1: assert(obj->is_oop_or_null(true )) failed: Error Summary: A referent object that is only weakly reachable at the start of concurrent marking but is re-attached to the strongly reachable object graph during marking may not be marked as live. This can cause the reference object to be processed prematurely and leave dangling pointers to the referent object. Implement a read barrier for the java.lang.ref.Reference::referent field by intrinsifying the Reference.get() method, and intercepting accesses though JNI, reflection, and Unsafe, so that when a non-null referent object is read it is also logged in an SATB buffer. Reviewed-by: kvn, iveresov, never, tonyp, dholmes
author johnc
date Thu, 07 Apr 2011 09:53:20 -0700
parents c7f3d0b4570f
children 92add02409c9
line wrap: on
line source
/*
 * Copyright (c) 2000, 2011, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 *
 */

#include "precompiled.hpp"
#include "classfile/vmSymbols.hpp"
#ifndef SERIALGC
#include "gc_implementation/g1/g1SATBCardTableModRefBS.hpp"
#endif // SERIALGC
#include "memory/allocation.inline.hpp"
#include "prims/jni.h"
#include "prims/jvm.h"
#include "runtime/globals.hpp"
#include "runtime/interfaceSupport.hpp"
#include "runtime/reflection.hpp"
#include "runtime/reflectionCompat.hpp"
#include "runtime/synchronizer.hpp"
#include "services/threadService.hpp"
#include "utilities/copy.hpp"
#include "utilities/dtrace.hpp"

/*
 *      Implementation of class sun.misc.Unsafe
 */

HS_DTRACE_PROBE_DECL3(hotspot, thread__park__begin, uintptr_t, int, long long);
HS_DTRACE_PROBE_DECL1(hotspot, thread__park__end, uintptr_t);
HS_DTRACE_PROBE_DECL1(hotspot, thread__unpark, uintptr_t);

#define MAX_OBJECT_SIZE \
  ( arrayOopDesc::header_size(T_DOUBLE) * HeapWordSize \
    + ((julong)max_jint * sizeof(double)) )


#define UNSAFE_ENTRY(result_type, header) \
  JVM_ENTRY(result_type, header)

// Can't use UNSAFE_LEAF because it has the signature of a straight
// call into the runtime (just like JVM_LEAF, funny that) but it's
// called like a Java Native and thus the wrapper built for it passes
// arguments like a JNI call.  It expects those arguments to be popped
// from the stack on Intel like all good JNI args are, and adjusts the
// stack according.  Since the JVM_LEAF call expects no extra
// arguments the stack isn't popped in the C code, is pushed by the
// wrapper and we get sick.
//#define UNSAFE_LEAF(result_type, header) \
//  JVM_LEAF(result_type, header)

#define UNSAFE_END JVM_END

#define UnsafeWrapper(arg) /*nothing, for the present*/


inline void* addr_from_java(jlong addr) {
  // This assert fails in a variety of ways on 32-bit systems.
  // It is impossible to predict whether native code that converts
  // pointers to longs will sign-extend or zero-extend the addresses.
  //assert(addr == (uintptr_t)addr, "must not be odd high bits");
  return (void*)(uintptr_t)addr;
}

inline jlong addr_to_java(void* p) {
  assert(p == (void*)(uintptr_t)p, "must not be odd high bits");
  return (uintptr_t)p;
}


// Note: The VM's obj_field and related accessors use byte-scaled
// ("unscaled") offsets, just as the unsafe methods do.

// However, the method Unsafe.fieldOffset explicitly declines to
// guarantee this.  The field offset values manipulated by the Java user
// through the Unsafe API are opaque cookies that just happen to be byte
// offsets.  We represent this state of affairs by passing the cookies
// through conversion functions when going between the VM and the Unsafe API.
// The conversion functions just happen to be no-ops at present.

inline jlong field_offset_to_byte_offset(jlong field_offset) {
  return field_offset;
}

inline jlong field_offset_from_byte_offset(jlong byte_offset) {
  return byte_offset;
}

inline jint invocation_key_from_method_slot(jint slot) {
  return slot;
}

inline jint invocation_key_to_method_slot(jint key) {
  return key;
}

inline void* index_oop_from_field_offset_long(oop p, jlong field_offset) {
  jlong byte_offset = field_offset_to_byte_offset(field_offset);
  // Don't allow unsafe to be used to read or write the header word of oops
  assert(p == NULL || field_offset >= oopDesc::header_size(), "offset must be outside of header");
#ifdef ASSERT
  if (p != NULL) {
    assert(byte_offset >= 0 && byte_offset <= (jlong)MAX_OBJECT_SIZE, "sane offset");
    if (byte_offset == (jint)byte_offset) {
      void* ptr_plus_disp = (address)p + byte_offset;
      assert((void*)p->obj_field_addr<oop>((jint)byte_offset) == ptr_plus_disp,
             "raw [ptr+disp] must be consistent with oop::field_base");
    }
  }
#endif
  if (sizeof(char*) == sizeof(jint))    // (this constant folds!)
    return (address)p + (jint) byte_offset;
  else
    return (address)p +        byte_offset;
}

// Externally callable versions:
// (Use these in compiler intrinsics which emulate unsafe primitives.)
jlong Unsafe_field_offset_to_byte_offset(jlong field_offset) {
  return field_offset;
}
jlong Unsafe_field_offset_from_byte_offset(jlong byte_offset) {
  return byte_offset;
}
jint Unsafe_invocation_key_from_method_slot(jint slot) {
  return invocation_key_from_method_slot(slot);
}
jint Unsafe_invocation_key_to_method_slot(jint key) {
  return invocation_key_to_method_slot(key);
}


///// Data in the Java heap.

#define GET_FIELD(obj, offset, type_name, v) \
  oop p = JNIHandles::resolve(obj); \
  type_name v = *(type_name*)index_oop_from_field_offset_long(p, offset)

#define SET_FIELD(obj, offset, type_name, x) \
  oop p = JNIHandles::resolve(obj); \
  *(type_name*)index_oop_from_field_offset_long(p, offset) = x

#define GET_FIELD_VOLATILE(obj, offset, type_name, v) \
  oop p = JNIHandles::resolve(obj); \
  volatile type_name v = OrderAccess::load_acquire((volatile type_name*)index_oop_from_field_offset_long(p, offset));

#define SET_FIELD_VOLATILE(obj, offset, type_name, x) \
  oop p = JNIHandles::resolve(obj); \
  OrderAccess::release_store_fence((volatile type_name*)index_oop_from_field_offset_long(p, offset), x);

// Macros for oops that check UseCompressedOops

#define GET_OOP_FIELD(obj, offset, v) \
  oop p = JNIHandles::resolve(obj);   \
  oop v;                              \
  if (UseCompressedOops) {            \
    narrowOop n = *(narrowOop*)index_oop_from_field_offset_long(p, offset); \
    v = oopDesc::decode_heap_oop(n);                                \
  } else {                            \
    v = *(oop*)index_oop_from_field_offset_long(p, offset);                 \
  }

#define GET_OOP_FIELD_VOLATILE(obj, offset, v) \
  oop p = JNIHandles::resolve(obj);   \
  volatile oop v;                     \
  if (UseCompressedOops) {            \
    volatile narrowOop n = *(volatile narrowOop*)index_oop_from_field_offset_long(p, offset); \
    v = oopDesc::decode_heap_oop(n);                               \
  } else {                            \
    v = *(volatile oop*)index_oop_from_field_offset_long(p, offset);       \
  } \
  OrderAccess::acquire();


// Get/SetObject must be special-cased, since it works with handles.

// The xxx140 variants for backward compatibility do not allow a full-width offset.
UNSAFE_ENTRY(jobject, Unsafe_GetObject140(JNIEnv *env, jobject unsafe, jobject obj, jint offset))
  UnsafeWrapper("Unsafe_GetObject");
  if (obj == NULL)  THROW_0(vmSymbols::java_lang_NullPointerException());
  GET_OOP_FIELD(obj, offset, v)
  jobject ret = JNIHandles::make_local(env, v);
#ifndef SERIALGC
  // We could be accessing the referent field in a reference
  // object. If G1 is enabled then we need to register a non-null
  // referent with the SATB barrier.
  if (UseG1GC) {
    bool needs_barrier = false;

    if (ret != NULL) {
      if (offset == java_lang_ref_Reference::referent_offset) {
        oop o = JNIHandles::resolve_non_null(obj);
        klassOop k = o->klass();
        if (instanceKlass::cast(k)->reference_type() != REF_NONE) {
          assert(instanceKlass::cast(k)->is_subclass_of(SystemDictionary::Reference_klass()), "sanity");
          needs_barrier = true;
        }
      }
    }

    if (needs_barrier) {
      oop referent = JNIHandles::resolve(ret);
      G1SATBCardTableModRefBS::enqueue(referent);
    }
  }
#endif // SERIALGC
  return ret;
UNSAFE_END

UNSAFE_ENTRY(void, Unsafe_SetObject140(JNIEnv *env, jobject unsafe, jobject obj, jint offset, jobject x_h))
  UnsafeWrapper("Unsafe_SetObject");
  if (obj == NULL)  THROW(vmSymbols::java_lang_NullPointerException());
  oop x = JNIHandles::resolve(x_h);
  //SET_FIELD(obj, offset, oop, x);
  oop p = JNIHandles::resolve(obj);
  if (UseCompressedOops) {
    if (x != NULL) {
      // If there is a heap base pointer, we are obliged to emit a store barrier.
      oop_store((narrowOop*)index_oop_from_field_offset_long(p, offset), x);
    } else {
      narrowOop n = oopDesc::encode_heap_oop_not_null(x);
      *(narrowOop*)index_oop_from_field_offset_long(p, offset) = n;
    }
  } else {
    if (x != NULL) {
      // If there is a heap base pointer, we are obliged to emit a store barrier.
      oop_store((oop*)index_oop_from_field_offset_long(p, offset), x);
    } else {
      *(oop*)index_oop_from_field_offset_long(p, offset) = x;
    }
  }
UNSAFE_END

// The normal variants allow a null base pointer with an arbitrary address.
// But if the base pointer is non-null, the offset should make some sense.
// That is, it should be in the range [0, MAX_OBJECT_SIZE].
UNSAFE_ENTRY(jobject, Unsafe_GetObject(JNIEnv *env, jobject unsafe, jobject obj, jlong offset))
  UnsafeWrapper("Unsafe_GetObject");
  GET_OOP_FIELD(obj, offset, v)
  jobject ret = JNIHandles::make_local(env, v);
#ifndef SERIALGC
  // We could be accessing the referent field in a reference
  // object. If G1 is enabled then we need to register non-null
  // referent with the SATB barrier.
  if (UseG1GC) {
    bool needs_barrier = false;

    if (ret != NULL) {
      if (offset == java_lang_ref_Reference::referent_offset && obj != NULL) {
        oop o = JNIHandles::resolve(obj);
        klassOop k = o->klass();
        if (instanceKlass::cast(k)->reference_type() != REF_NONE) {
          assert(instanceKlass::cast(k)->is_subclass_of(SystemDictionary::Reference_klass()), "sanity");
          needs_barrier = true;
        }
      }
    }

    if (needs_barrier) {
      oop referent = JNIHandles::resolve(ret);
      G1SATBCardTableModRefBS::enqueue(referent);
    }
  }
#endif // SERIALGC
  return ret;
UNSAFE_END

UNSAFE_ENTRY(void, Unsafe_SetObject(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jobject x_h))
  UnsafeWrapper("Unsafe_SetObject");
  oop x = JNIHandles::resolve(x_h);
  oop p = JNIHandles::resolve(obj);
  if (UseCompressedOops) {
    oop_store((narrowOop*)index_oop_from_field_offset_long(p, offset), x);
  } else {
    oop_store((oop*)index_oop_from_field_offset_long(p, offset), x);
  }
UNSAFE_END

UNSAFE_ENTRY(jobject, Unsafe_GetObjectVolatile(JNIEnv *env, jobject unsafe, jobject obj, jlong offset))
  UnsafeWrapper("Unsafe_GetObjectVolatile");
  GET_OOP_FIELD_VOLATILE(obj, offset, v)
  return JNIHandles::make_local(env, v);
UNSAFE_END

UNSAFE_ENTRY(void, Unsafe_SetObjectVolatile(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jobject x_h))
  UnsafeWrapper("Unsafe_SetObjectVolatile");
  oop x = JNIHandles::resolve(x_h);
  oop p = JNIHandles::resolve(obj);
  void* addr = index_oop_from_field_offset_long(p, offset);
  OrderAccess::release();
  if (UseCompressedOops) {
    oop_store((narrowOop*)addr, x);
  } else {
    oop_store((oop*)addr, x);
  }
  OrderAccess::fence();
UNSAFE_END

#if defined(SPARC) || defined(X86)
// Sparc and X86 have atomic jlong (8 bytes) instructions

#else
// Keep old code for platforms which may not have atomic jlong (8 bytes) instructions

// Volatile long versions must use locks if !VM_Version::supports_cx8().
// support_cx8 is a surrogate for 'supports atomic long memory ops'.

UNSAFE_ENTRY(jlong, Unsafe_GetLongVolatile(JNIEnv *env, jobject unsafe, jobject obj, jlong offset))
  UnsafeWrapper("Unsafe_GetLongVolatile");
  {
    if (VM_Version::supports_cx8()) {
      GET_FIELD_VOLATILE(obj, offset, jlong, v);
      return v;
    }
    else {
      Handle p (THREAD, JNIHandles::resolve(obj));
      jlong* addr = (jlong*)(index_oop_from_field_offset_long(p(), offset));
      ObjectLocker ol(p, THREAD);
      jlong value = *addr;
      return value;
    }
  }
UNSAFE_END

UNSAFE_ENTRY(void, Unsafe_SetLongVolatile(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jlong x))
  UnsafeWrapper("Unsafe_SetLongVolatile");
  {
    if (VM_Version::supports_cx8()) {
      SET_FIELD_VOLATILE(obj, offset, jlong, x);
    }
    else {
      Handle p (THREAD, JNIHandles::resolve(obj));
      jlong* addr = (jlong*)(index_oop_from_field_offset_long(p(), offset));
      ObjectLocker ol(p, THREAD);
      *addr = x;
    }
  }
UNSAFE_END

#endif // not SPARC and not X86

#define DEFINE_GETSETOOP(jboolean, Boolean) \
 \
UNSAFE_ENTRY(jboolean, Unsafe_Get##Boolean##140(JNIEnv *env, jobject unsafe, jobject obj, jint offset)) \
  UnsafeWrapper("Unsafe_Get"#Boolean); \
  if (obj == NULL)  THROW_0(vmSymbols::java_lang_NullPointerException()); \
  GET_FIELD(obj, offset, jboolean, v); \
  return v; \
UNSAFE_END \
 \
UNSAFE_ENTRY(void, Unsafe_Set##Boolean##140(JNIEnv *env, jobject unsafe, jobject obj, jint offset, jboolean x)) \
  UnsafeWrapper("Unsafe_Set"#Boolean); \
  if (obj == NULL)  THROW(vmSymbols::java_lang_NullPointerException()); \
  SET_FIELD(obj, offset, jboolean, x); \
UNSAFE_END \
 \
UNSAFE_ENTRY(jboolean, Unsafe_Get##Boolean(JNIEnv *env, jobject unsafe, jobject obj, jlong offset)) \
  UnsafeWrapper("Unsafe_Get"#Boolean); \
  GET_FIELD(obj, offset, jboolean, v); \
  return v; \
UNSAFE_END \
 \
UNSAFE_ENTRY(void, Unsafe_Set##Boolean(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jboolean x)) \
  UnsafeWrapper("Unsafe_Set"#Boolean); \
  SET_FIELD(obj, offset, jboolean, x); \
UNSAFE_END \
 \
// END DEFINE_GETSETOOP.

DEFINE_GETSETOOP(jboolean, Boolean)
DEFINE_GETSETOOP(jbyte, Byte)
DEFINE_GETSETOOP(jshort, Short);
DEFINE_GETSETOOP(jchar, Char);
DEFINE_GETSETOOP(jint, Int);
DEFINE_GETSETOOP(jlong, Long);
DEFINE_GETSETOOP(jfloat, Float);
DEFINE_GETSETOOP(jdouble, Double);

#undef DEFINE_GETSETOOP

#define DEFINE_GETSETOOP_VOLATILE(jboolean, Boolean) \
 \
UNSAFE_ENTRY(jboolean, Unsafe_Get##Boolean##Volatile(JNIEnv *env, jobject unsafe, jobject obj, jlong offset)) \
  UnsafeWrapper("Unsafe_Get"#Boolean); \
  GET_FIELD_VOLATILE(obj, offset, jboolean, v); \
  return v; \
UNSAFE_END \
 \
UNSAFE_ENTRY(void, Unsafe_Set##Boolean##Volatile(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jboolean x)) \
  UnsafeWrapper("Unsafe_Set"#Boolean); \
  SET_FIELD_VOLATILE(obj, offset, jboolean, x); \
UNSAFE_END \
 \
// END DEFINE_GETSETOOP_VOLATILE.

DEFINE_GETSETOOP_VOLATILE(jboolean, Boolean)
DEFINE_GETSETOOP_VOLATILE(jbyte, Byte)
DEFINE_GETSETOOP_VOLATILE(jshort, Short);
DEFINE_GETSETOOP_VOLATILE(jchar, Char);
DEFINE_GETSETOOP_VOLATILE(jint, Int);
DEFINE_GETSETOOP_VOLATILE(jfloat, Float);
DEFINE_GETSETOOP_VOLATILE(jdouble, Double);

#if defined(SPARC) || defined(X86)
// Sparc and X86 have atomic jlong (8 bytes) instructions
DEFINE_GETSETOOP_VOLATILE(jlong, Long);
#endif

#undef DEFINE_GETSETOOP_VOLATILE

// The non-intrinsified versions of setOrdered just use setVolatile

UNSAFE_ENTRY(void, Unsafe_SetOrderedInt(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jint x))
  UnsafeWrapper("Unsafe_SetOrderedInt");
  SET_FIELD_VOLATILE(obj, offset, jint, x);
UNSAFE_END

UNSAFE_ENTRY(void, Unsafe_SetOrderedObject(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jobject x_h))
  UnsafeWrapper("Unsafe_SetOrderedObject");
  oop x = JNIHandles::resolve(x_h);
  oop p = JNIHandles::resolve(obj);
  void* addr = index_oop_from_field_offset_long(p, offset);
  OrderAccess::release();
  if (UseCompressedOops) {
    oop_store((narrowOop*)addr, x);
  } else {
    oop_store((oop*)addr, x);
  }
  OrderAccess::fence();
UNSAFE_END

UNSAFE_ENTRY(void, Unsafe_SetOrderedLong(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jlong x))
  UnsafeWrapper("Unsafe_SetOrderedLong");
#if defined(SPARC) || defined(X86)
  // Sparc and X86 have atomic jlong (8 bytes) instructions
  SET_FIELD_VOLATILE(obj, offset, jlong, x);
#else
  // Keep old code for platforms which may not have atomic long (8 bytes) instructions
  {
    if (VM_Version::supports_cx8()) {
      SET_FIELD_VOLATILE(obj, offset, jlong, x);
    }
    else {
      Handle p (THREAD, JNIHandles::resolve(obj));
      jlong* addr = (jlong*)(index_oop_from_field_offset_long(p(), offset));
      ObjectLocker ol(p, THREAD);
      *addr = x;
    }
  }
#endif
UNSAFE_END

////// Data in the C heap.

// Note:  These do not throw NullPointerException for bad pointers.
// They just crash.  Only a oop base pointer can generate a NullPointerException.
//
#define DEFINE_GETSETNATIVE(java_type, Type, native_type) \
 \
UNSAFE_ENTRY(java_type, Unsafe_GetNative##Type(JNIEnv *env, jobject unsafe, jlong addr)) \
  UnsafeWrapper("Unsafe_GetNative"#Type); \
  void* p = addr_from_java(addr); \
  JavaThread* t = JavaThread::current(); \
  t->set_doing_unsafe_access(true); \
  java_type x = *(volatile native_type*)p; \
  t->set_doing_unsafe_access(false); \
  return x; \
UNSAFE_END \
 \
UNSAFE_ENTRY(void, Unsafe_SetNative##Type(JNIEnv *env, jobject unsafe, jlong addr, java_type x)) \
  UnsafeWrapper("Unsafe_SetNative"#Type); \
  JavaThread* t = JavaThread::current(); \
  t->set_doing_unsafe_access(true); \
  void* p = addr_from_java(addr); \
  *(volatile native_type*)p = x; \
  t->set_doing_unsafe_access(false); \
UNSAFE_END \
 \
// END DEFINE_GETSETNATIVE.

DEFINE_GETSETNATIVE(jbyte, Byte, signed char)
DEFINE_GETSETNATIVE(jshort, Short, signed short);
DEFINE_GETSETNATIVE(jchar, Char, unsigned short);
DEFINE_GETSETNATIVE(jint, Int, jint);
// no long -- handled specially
DEFINE_GETSETNATIVE(jfloat, Float, float);
DEFINE_GETSETNATIVE(jdouble, Double, double);

#undef DEFINE_GETSETNATIVE

UNSAFE_ENTRY(jlong, Unsafe_GetNativeLong(JNIEnv *env, jobject unsafe, jlong addr))
  UnsafeWrapper("Unsafe_GetNativeLong");
  JavaThread* t = JavaThread::current();
  // We do it this way to avoid problems with access to heap using 64
  // bit loads, as jlong in heap could be not 64-bit aligned, and on
  // some CPUs (SPARC) it leads to SIGBUS.
  t->set_doing_unsafe_access(true);
  void* p = addr_from_java(addr);
  jlong x;
  if (((intptr_t)p & 7) == 0) {
    // jlong is aligned, do a volatile access
    x = *(volatile jlong*)p;
  } else {
    jlong_accessor acc;
    acc.words[0] = ((volatile jint*)p)[0];
    acc.words[1] = ((volatile jint*)p)[1];
    x = acc.long_value;
  }
  t->set_doing_unsafe_access(false);
  return x;
UNSAFE_END

UNSAFE_ENTRY(void, Unsafe_SetNativeLong(JNIEnv *env, jobject unsafe, jlong addr, jlong x))
  UnsafeWrapper("Unsafe_SetNativeLong");
  JavaThread* t = JavaThread::current();
  // see comment for Unsafe_GetNativeLong
  t->set_doing_unsafe_access(true);
  void* p = addr_from_java(addr);
  if (((intptr_t)p & 7) == 0) {
    // jlong is aligned, do a volatile access
    *(volatile jlong*)p = x;
  } else {
    jlong_accessor acc;
    acc.long_value = x;
    ((volatile jint*)p)[0] = acc.words[0];
    ((volatile jint*)p)[1] = acc.words[1];
  }
  t->set_doing_unsafe_access(false);
UNSAFE_END


UNSAFE_ENTRY(jlong, Unsafe_GetNativeAddress(JNIEnv *env, jobject unsafe, jlong addr))
  UnsafeWrapper("Unsafe_GetNativeAddress");
  void* p = addr_from_java(addr);
  return addr_to_java(*(void**)p);
UNSAFE_END

UNSAFE_ENTRY(void, Unsafe_SetNativeAddress(JNIEnv *env, jobject unsafe, jlong addr, jlong x))
  UnsafeWrapper("Unsafe_SetNativeAddress");
  void* p = addr_from_java(addr);
  *(void**)p = addr_from_java(x);
UNSAFE_END


////// Allocation requests

UNSAFE_ENTRY(jobject, Unsafe_AllocateInstance(JNIEnv *env, jobject unsafe, jclass cls))
  UnsafeWrapper("Unsafe_AllocateInstance");
  {
    ThreadToNativeFromVM ttnfv(thread);
    return env->AllocObject(cls);
  }
UNSAFE_END

UNSAFE_ENTRY(jlong, Unsafe_AllocateMemory(JNIEnv *env, jobject unsafe, jlong size))
  UnsafeWrapper("Unsafe_AllocateMemory");
  size_t sz = (size_t)size;
  if (sz != (julong)size || size < 0) {
    THROW_0(vmSymbols::java_lang_IllegalArgumentException());
  }
  if (sz == 0) {
    return 0;
  }
  sz = round_to(sz, HeapWordSize);
  void* x = os::malloc(sz);
  if (x == NULL) {
    THROW_0(vmSymbols::java_lang_OutOfMemoryError());
  }
  //Copy::fill_to_words((HeapWord*)x, sz / HeapWordSize);
  return addr_to_java(x);
UNSAFE_END

UNSAFE_ENTRY(jlong, Unsafe_ReallocateMemory(JNIEnv *env, jobject unsafe, jlong addr, jlong size))
  UnsafeWrapper("Unsafe_ReallocateMemory");
  void* p = addr_from_java(addr);
  size_t sz = (size_t)size;
  if (sz != (julong)size || size < 0) {
    THROW_0(vmSymbols::java_lang_IllegalArgumentException());
  }
  if (sz == 0) {
    os::free(p);
    return 0;
  }
  sz = round_to(sz, HeapWordSize);
  void* x = (p == NULL) ? os::malloc(sz) : os::realloc(p, sz);
  if (x == NULL) {
    THROW_0(vmSymbols::java_lang_OutOfMemoryError());
  }
  return addr_to_java(x);
UNSAFE_END

UNSAFE_ENTRY(void, Unsafe_FreeMemory(JNIEnv *env, jobject unsafe, jlong addr))
  UnsafeWrapper("Unsafe_FreeMemory");
  void* p = addr_from_java(addr);
  if (p == NULL) {
    return;
  }
  os::free(p);
UNSAFE_END

UNSAFE_ENTRY(void, Unsafe_SetMemory(JNIEnv *env, jobject unsafe, jlong addr, jlong size, jbyte value))
  UnsafeWrapper("Unsafe_SetMemory");
  size_t sz = (size_t)size;
  if (sz != (julong)size || size < 0) {
    THROW(vmSymbols::java_lang_IllegalArgumentException());
  }
  char* p = (char*) addr_from_java(addr);
  Copy::fill_to_memory_atomic(p, sz, value);
UNSAFE_END

UNSAFE_ENTRY(void, Unsafe_SetMemory2(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jlong size, jbyte value))
  UnsafeWrapper("Unsafe_SetMemory");
  size_t sz = (size_t)size;
  if (sz != (julong)size || size < 0) {
    THROW(vmSymbols::java_lang_IllegalArgumentException());
  }
  oop base = JNIHandles::resolve(obj);
  void* p = index_oop_from_field_offset_long(base, offset);
  Copy::fill_to_memory_atomic(p, sz, value);
UNSAFE_END

UNSAFE_ENTRY(void, Unsafe_CopyMemory(JNIEnv *env, jobject unsafe, jlong srcAddr, jlong dstAddr, jlong size))
  UnsafeWrapper("Unsafe_CopyMemory");
  if (size == 0) {
    return;
  }
  size_t sz = (size_t)size;
  if (sz != (julong)size || size < 0) {
    THROW(vmSymbols::java_lang_IllegalArgumentException());
  }
  void* src = addr_from_java(srcAddr);
  void* dst = addr_from_java(dstAddr);
  Copy::conjoint_memory_atomic(src, dst, sz);
UNSAFE_END

UNSAFE_ENTRY(void, Unsafe_CopyMemory2(JNIEnv *env, jobject unsafe, jobject srcObj, jlong srcOffset, jobject dstObj, jlong dstOffset, jlong size))
  UnsafeWrapper("Unsafe_CopyMemory");
  if (size == 0) {
    return;
  }
  size_t sz = (size_t)size;
  if (sz != (julong)size || size < 0) {
    THROW(vmSymbols::java_lang_IllegalArgumentException());
  }
  oop srcp = JNIHandles::resolve(srcObj);
  oop dstp = JNIHandles::resolve(dstObj);
  if (dstp != NULL && !dstp->is_typeArray()) {
    // NYI:  This works only for non-oop arrays at present.
    // Generalizing it would be reasonable, but requires card marking.
    // Also, autoboxing a Long from 0L in copyMemory(x,y, 0L,z, n) would be bad.
    THROW(vmSymbols::java_lang_IllegalArgumentException());
  }
  void* src = index_oop_from_field_offset_long(srcp, srcOffset);
  void* dst = index_oop_from_field_offset_long(dstp, dstOffset);
  Copy::conjoint_memory_atomic(src, dst, sz);
UNSAFE_END


////// Random queries

// See comment at file start about UNSAFE_LEAF
//UNSAFE_LEAF(jint, Unsafe_AddressSize())
UNSAFE_ENTRY(jint, Unsafe_AddressSize(JNIEnv *env, jobject unsafe))
  UnsafeWrapper("Unsafe_AddressSize");
  return sizeof(void*);
UNSAFE_END

// See comment at file start about UNSAFE_LEAF
//UNSAFE_LEAF(jint, Unsafe_PageSize())
UNSAFE_ENTRY(jint, Unsafe_PageSize(JNIEnv *env, jobject unsafe))
  UnsafeWrapper("Unsafe_PageSize");
  return os::vm_page_size();
UNSAFE_END

jint find_field_offset(jobject field, int must_be_static, TRAPS) {
  if (field == NULL) {
    THROW_0(vmSymbols::java_lang_NullPointerException());
  }

  oop reflected   = JNIHandles::resolve_non_null(field);
  oop mirror      = java_lang_reflect_Field::clazz(reflected);
  klassOop k      = java_lang_Class::as_klassOop(mirror);
  int slot        = java_lang_reflect_Field::slot(reflected);
  int modifiers   = java_lang_reflect_Field::modifiers(reflected);

  if (must_be_static >= 0) {
    int really_is_static = ((modifiers & JVM_ACC_STATIC) != 0);
    if (must_be_static != really_is_static) {
      THROW_0(vmSymbols::java_lang_IllegalArgumentException());
    }
  }

  int offset = instanceKlass::cast(k)->offset_from_fields(slot);
  return field_offset_from_byte_offset(offset);
}

UNSAFE_ENTRY(jlong, Unsafe_ObjectFieldOffset(JNIEnv *env, jobject unsafe, jobject field))
  UnsafeWrapper("Unsafe_ObjectFieldOffset");
  return find_field_offset(field, 0, THREAD);
UNSAFE_END

UNSAFE_ENTRY(jlong, Unsafe_StaticFieldOffset(JNIEnv *env, jobject unsafe, jobject field))
  UnsafeWrapper("Unsafe_StaticFieldOffset");
  return find_field_offset(field, 1, THREAD);
UNSAFE_END

UNSAFE_ENTRY(jobject, Unsafe_StaticFieldBaseFromField(JNIEnv *env, jobject unsafe, jobject field))
  UnsafeWrapper("Unsafe_StaticFieldBase");
  // Note:  In this VM implementation, a field address is always a short
  // offset from the base of a a klass metaobject.  Thus, the full dynamic
  // range of the return type is never used.  However, some implementations
  // might put the static field inside an array shared by many classes,
  // or even at a fixed address, in which case the address could be quite
  // large.  In that last case, this function would return NULL, since
  // the address would operate alone, without any base pointer.

  if (field == NULL)  THROW_0(vmSymbols::java_lang_NullPointerException());

  oop reflected   = JNIHandles::resolve_non_null(field);
  oop mirror      = java_lang_reflect_Field::clazz(reflected);
  int modifiers   = java_lang_reflect_Field::modifiers(reflected);

  if ((modifiers & JVM_ACC_STATIC) == 0) {
    THROW_0(vmSymbols::java_lang_IllegalArgumentException());
  }

  return JNIHandles::make_local(env, mirror);
UNSAFE_END

//@deprecated
UNSAFE_ENTRY(jint, Unsafe_FieldOffset(JNIEnv *env, jobject unsafe, jobject field))
  UnsafeWrapper("Unsafe_FieldOffset");
  // tries (but fails) to be polymorphic between static and non-static:
  jlong offset = find_field_offset(field, -1, THREAD);
  guarantee(offset == (jint)offset, "offset fits in 32 bits");
  return (jint)offset;
UNSAFE_END

//@deprecated
UNSAFE_ENTRY(jobject, Unsafe_StaticFieldBaseFromClass(JNIEnv *env, jobject unsafe, jobject clazz))
  UnsafeWrapper("Unsafe_StaticFieldBase");
  if (clazz == NULL) {
    THROW_0(vmSymbols::java_lang_NullPointerException());
  }
  return JNIHandles::make_local(env, JNIHandles::resolve_non_null(clazz));
UNSAFE_END

UNSAFE_ENTRY(void, Unsafe_EnsureClassInitialized(JNIEnv *env, jobject unsafe, jobject clazz))
  UnsafeWrapper("Unsafe_EnsureClassInitialized");
  if (clazz == NULL) {
    THROW(vmSymbols::java_lang_NullPointerException());
  }
  oop mirror = JNIHandles::resolve_non_null(clazz);
  instanceKlass* k = instanceKlass::cast(java_lang_Class::as_klassOop(mirror));
  if (k != NULL) {
    k->initialize(CHECK);
  }
UNSAFE_END

static void getBaseAndScale(int& base, int& scale, jclass acls, TRAPS) {
  if (acls == NULL) {
    THROW(vmSymbols::java_lang_NullPointerException());
  }
  oop      mirror = JNIHandles::resolve_non_null(acls);
  klassOop k      = java_lang_Class::as_klassOop(mirror);
  if (k == NULL || !k->klass_part()->oop_is_array()) {
    THROW(vmSymbols::java_lang_InvalidClassException());
  } else if (k->klass_part()->oop_is_objArray()) {
    base  = arrayOopDesc::base_offset_in_bytes(T_OBJECT);
    scale = heapOopSize;
  } else if (k->klass_part()->oop_is_typeArray()) {
    typeArrayKlass* tak = typeArrayKlass::cast(k);
    base  = tak->array_header_in_bytes();
    assert(base == arrayOopDesc::base_offset_in_bytes(tak->element_type()), "array_header_size semantics ok");
    scale = (1 << tak->log2_element_size());
  } else {
    ShouldNotReachHere();
  }
}

UNSAFE_ENTRY(jint, Unsafe_ArrayBaseOffset(JNIEnv *env, jobject unsafe, jclass acls))
  UnsafeWrapper("Unsafe_ArrayBaseOffset");
  int base, scale;
  getBaseAndScale(base, scale, acls, CHECK_0);
  return field_offset_from_byte_offset(base);
UNSAFE_END


UNSAFE_ENTRY(jint, Unsafe_ArrayIndexScale(JNIEnv *env, jobject unsafe, jclass acls))
  UnsafeWrapper("Unsafe_ArrayIndexScale");
  int base, scale;
  getBaseAndScale(base, scale, acls, CHECK_0);
  // This VM packs both fields and array elements down to the byte.
  // But watch out:  If this changes, so that array references for
  // a given primitive type (say, T_BOOLEAN) use different memory units
  // than fields, this method MUST return zero for such arrays.
  // For example, the VM used to store sub-word sized fields in full
  // words in the object layout, so that accessors like getByte(Object,int)
  // did not really do what one might expect for arrays.  Therefore,
  // this function used to report a zero scale factor, so that the user
  // would know not to attempt to access sub-word array elements.
  // // Code for unpacked fields:
  // if (scale < wordSize)  return 0;

  // The following allows for a pretty general fieldOffset cookie scheme,
  // but requires it to be linear in byte offset.
  return field_offset_from_byte_offset(scale) - field_offset_from_byte_offset(0);
UNSAFE_END


static inline void throw_new(JNIEnv *env, const char *ename) {
  char buf[100];
  strcpy(buf, "java/lang/");
  strcat(buf, ename);
  jclass cls = env->FindClass(buf);
  char* msg = NULL;
  env->ThrowNew(cls, msg);
}

static jclass Unsafe_DefineClass(JNIEnv *env, jstring name, jbyteArray data, int offset, int length, jobject loader, jobject pd) {
  {
    // Code lifted from JDK 1.3 ClassLoader.c

    jbyte *body;
    char *utfName;
    jclass result = 0;
    char buf[128];

    if (UsePerfData) {
      ClassLoader::unsafe_defineClassCallCounter()->inc();
    }

    if (data == NULL) {
        throw_new(env, "NullPointerException");
        return 0;
    }

    /* Work around 4153825. malloc crashes on Solaris when passed a
     * negative size.
     */
    if (length < 0) {
        throw_new(env, "ArrayIndexOutOfBoundsException");
        return 0;
    }

    body = NEW_C_HEAP_ARRAY(jbyte, length);

    if (body == 0) {
        throw_new(env, "OutOfMemoryError");
        return 0;
    }

    env->GetByteArrayRegion(data, offset, length, body);

    if (env->ExceptionOccurred())
        goto free_body;

    if (name != NULL) {
        uint len = env->GetStringUTFLength(name);
        int unicode_len = env->GetStringLength(name);
        if (len >= sizeof(buf)) {
            utfName = NEW_C_HEAP_ARRAY(char, len + 1);
            if (utfName == NULL) {
                throw_new(env, "OutOfMemoryError");
                goto free_body;
            }
        } else {
            utfName = buf;
        }
        env->GetStringUTFRegion(name, 0, unicode_len, utfName);
        //VerifyFixClassname(utfName);
        for (uint i = 0; i < len; i++) {
          if (utfName[i] == '.')   utfName[i] = '/';
        }
    } else {
        utfName = NULL;
    }

    result = JVM_DefineClass(env, utfName, loader, body, length, pd);

    if (utfName && utfName != buf)
        FREE_C_HEAP_ARRAY(char, utfName);

 free_body:
    FREE_C_HEAP_ARRAY(jbyte, body);
    return result;
  }
}


UNSAFE_ENTRY(jclass, Unsafe_DefineClass0(JNIEnv *env, jobject unsafe, jstring name, jbyteArray data, int offset, int length))
  UnsafeWrapper("Unsafe_DefineClass");
  {
    ThreadToNativeFromVM ttnfv(thread);

    int depthFromDefineClass0 = 1;
    jclass  caller = JVM_GetCallerClass(env, depthFromDefineClass0);
    jobject loader = (caller == NULL) ? NULL : JVM_GetClassLoader(env, caller);
    jobject pd     = (caller == NULL) ? NULL : JVM_GetProtectionDomain(env, caller);

    return Unsafe_DefineClass(env, name, data, offset, length, loader, pd);
  }
UNSAFE_END


UNSAFE_ENTRY(jclass, Unsafe_DefineClass1(JNIEnv *env, jobject unsafe, jstring name, jbyteArray data, int offset, int length, jobject loader, jobject pd))
  UnsafeWrapper("Unsafe_DefineClass");
  {
    ThreadToNativeFromVM ttnfv(thread);

    return Unsafe_DefineClass(env, name, data, offset, length, loader, pd);
  }
UNSAFE_END

#define DAC_Args CLS"[B["OBJ
// define a class but do not make it known to the class loader or system dictionary
// - host_class:  supplies context for linkage, access control, protection domain, and class loader
// - data:  bytes of a class file, a raw memory address (length gives the number of bytes)
// - cp_patches:  where non-null entries exist, they replace corresponding CP entries in data

// When you load an anonymous class U, it works as if you changed its name just before loading,
// to a name that you will never use again.  Since the name is lost, no other class can directly
// link to any member of U.  Just after U is loaded, the only way to use it is reflectively,
// through java.lang.Class methods like Class.newInstance.

// Access checks for linkage sites within U continue to follow the same rules as for named classes.
// The package of an anonymous class is given by the package qualifier on the name under which it was loaded.
// An anonymous class also has special privileges to access any member of its host class.
// This is the main reason why this loading operation is unsafe.  The purpose of this is to
// allow language implementations to simulate "open classes"; a host class in effect gets
// new code when an anonymous class is loaded alongside it.  A less convenient but more
// standard way to do this is with reflection, which can also be set to ignore access
// restrictions.

// Access into an anonymous class is possible only through reflection.  Therefore, there
// are no special access rules for calling into an anonymous class.  The relaxed access
// rule for the host class is applied in the opposite direction:  A host class reflectively
// access one of its anonymous classes.

// If you load the same bytecodes twice, you get two different classes.  You can reload
// the same bytecodes with or without varying CP patches.

// By using the CP patching array, you can have a new anonymous class U2 refer to an older one U1.
// The bytecodes for U2 should refer to U1 by a symbolic name (doesn't matter what the name is).
// The CONSTANT_Class entry for that name can be patched to refer directly to U1.

// This allows, for example, U2 to use U1 as a superclass or super-interface, or as
// an outer class (so that U2 is an anonymous inner class of anonymous U1).
// It is not possible for a named class, or an older anonymous class, to refer by
// name (via its CP) to a newer anonymous class.

// CP patching may also be used to modify (i.e., hack) the names of methods, classes,
// or type descriptors used in the loaded anonymous class.

// Finally, CP patching may be used to introduce "live" objects into the constant pool,
// instead of "dead" strings.  A compiled statement like println((Object)"hello") can
// be changed to println(greeting), where greeting is an arbitrary object created before
// the anonymous class is loaded.  This is useful in dynamic languages, in which
// various kinds of metaobjects must be introduced as constants into bytecode.
// Note the cast (Object), which tells the verifier to expect an arbitrary object,
// not just a literal string.  For such ldc instructions, the verifier uses the
// type Object instead of String, if the loaded constant is not in fact a String.

static oop
Unsafe_DefineAnonymousClass_impl(JNIEnv *env,
                                 jclass host_class, jbyteArray data, jobjectArray cp_patches_jh,
                                 HeapWord* *temp_alloc,
                                 TRAPS) {

  if (UsePerfData) {
    ClassLoader::unsafe_defineClassCallCounter()->inc();
  }

  if (data == NULL) {
    THROW_0(vmSymbols::java_lang_NullPointerException());
  }

  jint length = typeArrayOop(JNIHandles::resolve_non_null(data))->length();
  jint word_length = (length + sizeof(HeapWord)-1) / sizeof(HeapWord);
  HeapWord* body = NEW_C_HEAP_ARRAY(HeapWord, word_length);
  if (body == NULL) {
    THROW_0(vmSymbols::java_lang_OutOfMemoryError());
  }

  // caller responsible to free it:
  (*temp_alloc) = body;

  {
    jbyte* array_base = typeArrayOop(JNIHandles::resolve_non_null(data))->byte_at_addr(0);
    Copy::conjoint_words((HeapWord*) array_base, body, word_length);
  }

  u1* class_bytes = (u1*) body;
  int class_bytes_length = (int) length;
  if (class_bytes_length < 0)  class_bytes_length = 0;
  if (class_bytes == NULL
      || host_class == NULL
      || length != class_bytes_length)
    THROW_0(vmSymbols::java_lang_IllegalArgumentException());

  objArrayHandle cp_patches_h;
  if (cp_patches_jh != NULL) {
    oop p = JNIHandles::resolve_non_null(cp_patches_jh);
    if (!p->is_objArray())
      THROW_0(vmSymbols::java_lang_IllegalArgumentException());
    cp_patches_h = objArrayHandle(THREAD, (objArrayOop)p);
  }

  KlassHandle host_klass(THREAD, java_lang_Class::as_klassOop(JNIHandles::resolve_non_null(host_class)));
  const char* host_source = host_klass->external_name();
  Handle      host_loader(THREAD, host_klass->class_loader());
  Handle      host_domain(THREAD, host_klass->protection_domain());

  GrowableArray<Handle>* cp_patches = NULL;
  if (cp_patches_h.not_null()) {
    int alen = cp_patches_h->length();
    for (int i = alen-1; i >= 0; i--) {
      oop p = cp_patches_h->obj_at(i);
      if (p != NULL) {
        Handle patch(THREAD, p);
        if (cp_patches == NULL)
          cp_patches = new GrowableArray<Handle>(i+1, i+1, Handle());
        cp_patches->at_put(i, patch);
      }
    }
  }

  ClassFileStream st(class_bytes, class_bytes_length, (char*) host_source);

  instanceKlassHandle anon_klass;
  {
    Symbol* no_class_name = NULL;
    klassOop anonk = SystemDictionary::parse_stream(no_class_name,
                                                    host_loader, host_domain,
                                                    &st, host_klass, cp_patches,
                                                    CHECK_NULL);
    if (anonk == NULL)  return NULL;
    anon_klass = instanceKlassHandle(THREAD, anonk);
  }

  // let caller initialize it as needed...

  return anon_klass->java_mirror();
}

UNSAFE_ENTRY(jclass, Unsafe_DefineAnonymousClass(JNIEnv *env, jobject unsafe, jclass host_class, jbyteArray data, jobjectArray cp_patches_jh))
{
  UnsafeWrapper("Unsafe_DefineAnonymousClass");
  ResourceMark rm(THREAD);

  HeapWord* temp_alloc = NULL;

  jobject res_jh = NULL;

  { oop res_oop = Unsafe_DefineAnonymousClass_impl(env,
                                                   host_class, data, cp_patches_jh,
                                                   &temp_alloc, THREAD);
    if (res_oop != NULL)
      res_jh = JNIHandles::make_local(env, res_oop);
  }

  // try/finally clause:
  if (temp_alloc != NULL) {
    FREE_C_HEAP_ARRAY(HeapWord, temp_alloc);
  }

  return (jclass) res_jh;
}
UNSAFE_END



UNSAFE_ENTRY(void, Unsafe_MonitorEnter(JNIEnv *env, jobject unsafe, jobject jobj))
  UnsafeWrapper("Unsafe_MonitorEnter");
  {
    if (jobj == NULL) {
      THROW(vmSymbols::java_lang_NullPointerException());
    }
    Handle obj(thread, JNIHandles::resolve_non_null(jobj));
    ObjectSynchronizer::jni_enter(obj, CHECK);
  }
UNSAFE_END


UNSAFE_ENTRY(jboolean, Unsafe_TryMonitorEnter(JNIEnv *env, jobject unsafe, jobject jobj))
  UnsafeWrapper("Unsafe_TryMonitorEnter");
  {
    if (jobj == NULL) {
      THROW_(vmSymbols::java_lang_NullPointerException(), JNI_FALSE);
    }
    Handle obj(thread, JNIHandles::resolve_non_null(jobj));
    bool res = ObjectSynchronizer::jni_try_enter(obj, CHECK_0);
    return (res ? JNI_TRUE : JNI_FALSE);
  }
UNSAFE_END


UNSAFE_ENTRY(void, Unsafe_MonitorExit(JNIEnv *env, jobject unsafe, jobject jobj))
  UnsafeWrapper("Unsafe_MonitorExit");
  {
    if (jobj == NULL) {
      THROW(vmSymbols::java_lang_NullPointerException());
    }
    Handle obj(THREAD, JNIHandles::resolve_non_null(jobj));
    ObjectSynchronizer::jni_exit(obj(), CHECK);
  }
UNSAFE_END


UNSAFE_ENTRY(void, Unsafe_ThrowException(JNIEnv *env, jobject unsafe, jthrowable thr))
  UnsafeWrapper("Unsafe_ThrowException");
  {
    ThreadToNativeFromVM ttnfv(thread);
    env->Throw(thr);
  }
UNSAFE_END

// JSR166 ------------------------------------------------------------------

UNSAFE_ENTRY(jboolean, Unsafe_CompareAndSwapObject(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jobject e_h, jobject x_h))
  UnsafeWrapper("Unsafe_CompareAndSwapObject");
  oop x = JNIHandles::resolve(x_h);
  oop e = JNIHandles::resolve(e_h);
  oop p = JNIHandles::resolve(obj);
  HeapWord* addr = (HeapWord *)index_oop_from_field_offset_long(p, offset);
  if (UseCompressedOops) {
    update_barrier_set_pre((narrowOop*)addr, e);
  } else {
    update_barrier_set_pre((oop*)addr, e);
  }
  oop res = oopDesc::atomic_compare_exchange_oop(x, addr, e);
  jboolean success  = (res == e);
  if (success)
    update_barrier_set((void*)addr, x);
  return success;
UNSAFE_END

UNSAFE_ENTRY(jboolean, Unsafe_CompareAndSwapInt(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jint e, jint x))
  UnsafeWrapper("Unsafe_CompareAndSwapInt");
  oop p = JNIHandles::resolve(obj);
  jint* addr = (jint *) index_oop_from_field_offset_long(p, offset);
  return (jint)(Atomic::cmpxchg(x, addr, e)) == e;
UNSAFE_END

UNSAFE_ENTRY(jboolean, Unsafe_CompareAndSwapLong(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jlong e, jlong x))
  UnsafeWrapper("Unsafe_CompareAndSwapLong");
  Handle p (THREAD, JNIHandles::resolve(obj));
  jlong* addr = (jlong*)(index_oop_from_field_offset_long(p(), offset));
  if (VM_Version::supports_cx8())
    return (jlong)(Atomic::cmpxchg(x, addr, e)) == e;
  else {
    jboolean success = false;
    ObjectLocker ol(p, THREAD);
    if (*addr == e) { *addr = x; success = true; }
    return success;
  }
UNSAFE_END

UNSAFE_ENTRY(void, Unsafe_Park(JNIEnv *env, jobject unsafe, jboolean isAbsolute, jlong time))
  UnsafeWrapper("Unsafe_Park");
  HS_DTRACE_PROBE3(hotspot, thread__park__begin, thread->parker(), (int) isAbsolute, time);
  JavaThreadParkedState jtps(thread, time != 0);
  thread->parker()->park(isAbsolute != 0, time);
  HS_DTRACE_PROBE1(hotspot, thread__park__end, thread->parker());
UNSAFE_END

UNSAFE_ENTRY(void, Unsafe_Unpark(JNIEnv *env, jobject unsafe, jobject jthread))
  UnsafeWrapper("Unsafe_Unpark");
  Parker* p = NULL;
  if (jthread != NULL) {
    oop java_thread = JNIHandles::resolve_non_null(jthread);
    if (java_thread != NULL) {
      jlong lp = java_lang_Thread::park_event(java_thread);
      if (lp != 0) {
        // This cast is OK even though the jlong might have been read
        // non-atomically on 32bit systems, since there, one word will
        // always be zero anyway and the value set is always the same
        p = (Parker*)addr_from_java(lp);
      } else {
        // Grab lock if apparently null or using older version of library
        MutexLocker mu(Threads_lock);
        java_thread = JNIHandles::resolve_non_null(jthread);
        if (java_thread != NULL) {
          JavaThread* thr = java_lang_Thread::thread(java_thread);
          if (thr != NULL) {
            p = thr->parker();
            if (p != NULL) { // Bind to Java thread for next time.
              java_lang_Thread::set_park_event(java_thread, addr_to_java(p));
            }
          }
        }
      }
    }
  }
  if (p != NULL) {
    HS_DTRACE_PROBE1(hotspot, thread__unpark, p);
    p->unpark();
  }
UNSAFE_END

UNSAFE_ENTRY(jint, Unsafe_Loadavg(JNIEnv *env, jobject unsafe, jdoubleArray loadavg, jint nelem))
  UnsafeWrapper("Unsafe_Loadavg");
  const int max_nelem = 3;
  double la[max_nelem];
  jint ret;

  typeArrayOop a = typeArrayOop(JNIHandles::resolve_non_null(loadavg));
  assert(a->is_typeArray(), "must be type array");

  if (nelem < 0 || nelem > max_nelem || a->length() < nelem) {
    ThreadToNativeFromVM ttnfv(thread);
    throw_new(env, "ArrayIndexOutOfBoundsException");
    return -1;
  }

  ret = os::loadavg(la, nelem);
  if (ret == -1) return -1;

  // if successful, ret is the number of samples actually retrieved.
  assert(ret >= 0 && ret <= max_nelem, "Unexpected loadavg return value");
  switch(ret) {
    case 3: a->double_at_put(2, (jdouble)la[2]); // fall through
    case 2: a->double_at_put(1, (jdouble)la[1]); // fall through
    case 1: a->double_at_put(0, (jdouble)la[0]); break;
  }
  return ret;
UNSAFE_END

UNSAFE_ENTRY(void, Unsafe_PrefetchRead(JNIEnv* env, jclass ignored, jobject obj, jlong offset))
  UnsafeWrapper("Unsafe_PrefetchRead");
  oop p = JNIHandles::resolve(obj);
  void* addr = index_oop_from_field_offset_long(p, 0);
  Prefetch::read(addr, (intx)offset);
UNSAFE_END

UNSAFE_ENTRY(void, Unsafe_PrefetchWrite(JNIEnv* env, jclass ignored, jobject obj, jlong offset))
  UnsafeWrapper("Unsafe_PrefetchWrite");
  oop p = JNIHandles::resolve(obj);
  void* addr = index_oop_from_field_offset_long(p, 0);
  Prefetch::write(addr, (intx)offset);
UNSAFE_END


/// JVM_RegisterUnsafeMethods

#define ADR "J"

#define LANG "Ljava/lang/"

#define OBJ LANG"Object;"
#define CLS LANG"Class;"
#define CTR LANG"reflect/Constructor;"
#define FLD LANG"reflect/Field;"
#define MTH LANG"reflect/Method;"
#define THR LANG"Throwable;"

#define DC0_Args LANG"String;[BII"
#define DC1_Args DC0_Args LANG"ClassLoader;" "Ljava/security/ProtectionDomain;"

#define CC (char*)  /*cast a literal from (const char*)*/
#define FN_PTR(f) CAST_FROM_FN_PTR(void*, &f)

// define deprecated accessors for compabitility with 1.4.0
#define DECLARE_GETSETOOP_140(Boolean, Z) \
    {CC"get"#Boolean,      CC"("OBJ"I)"#Z,      FN_PTR(Unsafe_Get##Boolean##140)}, \
    {CC"put"#Boolean,      CC"("OBJ"I"#Z")V",   FN_PTR(Unsafe_Set##Boolean##140)}

// Note:  In 1.4.1, getObject and kin take both int and long offsets.
#define DECLARE_GETSETOOP_141(Boolean, Z) \
    {CC"get"#Boolean,      CC"("OBJ"J)"#Z,      FN_PTR(Unsafe_Get##Boolean)}, \
    {CC"put"#Boolean,      CC"("OBJ"J"#Z")V",   FN_PTR(Unsafe_Set##Boolean)}

// Note:  In 1.5.0, there are volatile versions too
#define DECLARE_GETSETOOP(Boolean, Z) \
    {CC"get"#Boolean,      CC"("OBJ"J)"#Z,      FN_PTR(Unsafe_Get##Boolean)}, \
    {CC"put"#Boolean,      CC"("OBJ"J"#Z")V",   FN_PTR(Unsafe_Set##Boolean)}, \
    {CC"get"#Boolean"Volatile",      CC"("OBJ"J)"#Z,      FN_PTR(Unsafe_Get##Boolean##Volatile)}, \
    {CC"put"#Boolean"Volatile",      CC"("OBJ"J"#Z")V",   FN_PTR(Unsafe_Set##Boolean##Volatile)}


#define DECLARE_GETSETNATIVE(Byte, B) \
    {CC"get"#Byte,         CC"("ADR")"#B,       FN_PTR(Unsafe_GetNative##Byte)}, \
    {CC"put"#Byte,         CC"("ADR#B")V",      FN_PTR(Unsafe_SetNative##Byte)}



// %%% These are temporarily supported until the SDK sources
// contain the necessarily updated Unsafe.java.
static JNINativeMethod methods_140[] = {

    {CC"getObject",        CC"("OBJ"I)"OBJ"",   FN_PTR(Unsafe_GetObject140)},
    {CC"putObject",        CC"("OBJ"I"OBJ")V",  FN_PTR(Unsafe_SetObject140)},

    DECLARE_GETSETOOP_140(Boolean, Z),
    DECLARE_GETSETOOP_140(Byte, B),
    DECLARE_GETSETOOP_140(Short, S),
    DECLARE_GETSETOOP_140(Char, C),
    DECLARE_GETSETOOP_140(Int, I),
    DECLARE_GETSETOOP_140(Long, J),
    DECLARE_GETSETOOP_140(Float, F),
    DECLARE_GETSETOOP_140(Double, D),

    DECLARE_GETSETNATIVE(Byte, B),
    DECLARE_GETSETNATIVE(Short, S),
    DECLARE_GETSETNATIVE(Char, C),
    DECLARE_GETSETNATIVE(Int, I),
    DECLARE_GETSETNATIVE(Long, J),
    DECLARE_GETSETNATIVE(Float, F),
    DECLARE_GETSETNATIVE(Double, D),

    {CC"getAddress",         CC"("ADR")"ADR,             FN_PTR(Unsafe_GetNativeAddress)},
    {CC"putAddress",         CC"("ADR""ADR")V",          FN_PTR(Unsafe_SetNativeAddress)},

    {CC"allocateMemory",     CC"(J)"ADR,                 FN_PTR(Unsafe_AllocateMemory)},
    {CC"reallocateMemory",   CC"("ADR"J)"ADR,            FN_PTR(Unsafe_ReallocateMemory)},
//  {CC"setMemory",          CC"("ADR"JB)V",             FN_PTR(Unsafe_SetMemory)},
//  {CC"copyMemory",         CC"("ADR ADR"J)V",          FN_PTR(Unsafe_CopyMemory)},
    {CC"freeMemory",         CC"("ADR")V",               FN_PTR(Unsafe_FreeMemory)},

    {CC"fieldOffset",        CC"("FLD")I",               FN_PTR(Unsafe_FieldOffset)}, //deprecated
    {CC"staticFieldBase",    CC"("CLS")"OBJ,             FN_PTR(Unsafe_StaticFieldBaseFromClass)}, //deprecated
    {CC"ensureClassInitialized",CC"("CLS")V",            FN_PTR(Unsafe_EnsureClassInitialized)},
    {CC"arrayBaseOffset",    CC"("CLS")I",               FN_PTR(Unsafe_ArrayBaseOffset)},
    {CC"arrayIndexScale",    CC"("CLS")I",               FN_PTR(Unsafe_ArrayIndexScale)},
    {CC"addressSize",        CC"()I",                    FN_PTR(Unsafe_AddressSize)},
    {CC"pageSize",           CC"()I",                    FN_PTR(Unsafe_PageSize)},

    {CC"defineClass",        CC"("DC0_Args")"CLS,        FN_PTR(Unsafe_DefineClass0)},
    {CC"defineClass",        CC"("DC1_Args")"CLS,        FN_PTR(Unsafe_DefineClass1)},
    {CC"allocateInstance",   CC"("CLS")"OBJ,             FN_PTR(Unsafe_AllocateInstance)},
    {CC"monitorEnter",       CC"("OBJ")V",               FN_PTR(Unsafe_MonitorEnter)},
    {CC"monitorExit",        CC"("OBJ")V",               FN_PTR(Unsafe_MonitorExit)},
    {CC"throwException",     CC"("THR")V",               FN_PTR(Unsafe_ThrowException)}
};

// These are the old methods prior to the JSR 166 changes in 1.5.0
static JNINativeMethod methods_141[] = {

    {CC"getObject",        CC"("OBJ"J)"OBJ"",   FN_PTR(Unsafe_GetObject)},
    {CC"putObject",        CC"("OBJ"J"OBJ")V",  FN_PTR(Unsafe_SetObject)},

    DECLARE_GETSETOOP_141(Boolean, Z),
    DECLARE_GETSETOOP_141(Byte, B),
    DECLARE_GETSETOOP_141(Short, S),
    DECLARE_GETSETOOP_141(Char, C),
    DECLARE_GETSETOOP_141(Int, I),
    DECLARE_GETSETOOP_141(Long, J),
    DECLARE_GETSETOOP_141(Float, F),
    DECLARE_GETSETOOP_141(Double, D),

    DECLARE_GETSETNATIVE(Byte, B),
    DECLARE_GETSETNATIVE(Short, S),
    DECLARE_GETSETNATIVE(Char, C),
    DECLARE_GETSETNATIVE(Int, I),
    DECLARE_GETSETNATIVE(Long, J),
    DECLARE_GETSETNATIVE(Float, F),
    DECLARE_GETSETNATIVE(Double, D),

    {CC"getAddress",         CC"("ADR")"ADR,             FN_PTR(Unsafe_GetNativeAddress)},
    {CC"putAddress",         CC"("ADR""ADR")V",          FN_PTR(Unsafe_SetNativeAddress)},

    {CC"allocateMemory",     CC"(J)"ADR,                 FN_PTR(Unsafe_AllocateMemory)},
    {CC"reallocateMemory",   CC"("ADR"J)"ADR,            FN_PTR(Unsafe_ReallocateMemory)},
//  {CC"setMemory",          CC"("ADR"JB)V",             FN_PTR(Unsafe_SetMemory)},
//  {CC"copyMemory",         CC"("ADR ADR"J)V",          FN_PTR(Unsafe_CopyMemory)},
    {CC"freeMemory",         CC"("ADR")V",               FN_PTR(Unsafe_FreeMemory)},

    {CC"objectFieldOffset",  CC"("FLD")J",               FN_PTR(Unsafe_ObjectFieldOffset)},
    {CC"staticFieldOffset",  CC"("FLD")J",               FN_PTR(Unsafe_StaticFieldOffset)},
    {CC"staticFieldBase",    CC"("FLD")"OBJ,             FN_PTR(Unsafe_StaticFieldBaseFromField)},
    {CC"ensureClassInitialized",CC"("CLS")V",            FN_PTR(Unsafe_EnsureClassInitialized)},
    {CC"arrayBaseOffset",    CC"("CLS")I",               FN_PTR(Unsafe_ArrayBaseOffset)},
    {CC"arrayIndexScale",    CC"("CLS")I",               FN_PTR(Unsafe_ArrayIndexScale)},
    {CC"addressSize",        CC"()I",                    FN_PTR(Unsafe_AddressSize)},
    {CC"pageSize",           CC"()I",                    FN_PTR(Unsafe_PageSize)},

    {CC"defineClass",        CC"("DC0_Args")"CLS,        FN_PTR(Unsafe_DefineClass0)},
    {CC"defineClass",        CC"("DC1_Args")"CLS,        FN_PTR(Unsafe_DefineClass1)},
    {CC"allocateInstance",   CC"("CLS")"OBJ,             FN_PTR(Unsafe_AllocateInstance)},
    {CC"monitorEnter",       CC"("OBJ")V",               FN_PTR(Unsafe_MonitorEnter)},
    {CC"monitorExit",        CC"("OBJ")V",               FN_PTR(Unsafe_MonitorExit)},
    {CC"throwException",     CC"("THR")V",               FN_PTR(Unsafe_ThrowException)}

};

// These are the old methods prior to the JSR 166 changes in 1.6.0
static JNINativeMethod methods_15[] = {

    {CC"getObject",        CC"("OBJ"J)"OBJ"",   FN_PTR(Unsafe_GetObject)},
    {CC"putObject",        CC"("OBJ"J"OBJ")V",  FN_PTR(Unsafe_SetObject)},
    {CC"getObjectVolatile",CC"("OBJ"J)"OBJ"",   FN_PTR(Unsafe_GetObjectVolatile)},
    {CC"putObjectVolatile",CC"("OBJ"J"OBJ")V",  FN_PTR(Unsafe_SetObjectVolatile)},


    DECLARE_GETSETOOP(Boolean, Z),
    DECLARE_GETSETOOP(Byte, B),
    DECLARE_GETSETOOP(Short, S),
    DECLARE_GETSETOOP(Char, C),
    DECLARE_GETSETOOP(Int, I),
    DECLARE_GETSETOOP(Long, J),
    DECLARE_GETSETOOP(Float, F),
    DECLARE_GETSETOOP(Double, D),

    DECLARE_GETSETNATIVE(Byte, B),
    DECLARE_GETSETNATIVE(Short, S),
    DECLARE_GETSETNATIVE(Char, C),
    DECLARE_GETSETNATIVE(Int, I),
    DECLARE_GETSETNATIVE(Long, J),
    DECLARE_GETSETNATIVE(Float, F),
    DECLARE_GETSETNATIVE(Double, D),

    {CC"getAddress",         CC"("ADR")"ADR,             FN_PTR(Unsafe_GetNativeAddress)},
    {CC"putAddress",         CC"("ADR""ADR")V",          FN_PTR(Unsafe_SetNativeAddress)},

    {CC"allocateMemory",     CC"(J)"ADR,                 FN_PTR(Unsafe_AllocateMemory)},
    {CC"reallocateMemory",   CC"("ADR"J)"ADR,            FN_PTR(Unsafe_ReallocateMemory)},
//  {CC"setMemory",          CC"("ADR"JB)V",             FN_PTR(Unsafe_SetMemory)},
//  {CC"copyMemory",         CC"("ADR ADR"J)V",          FN_PTR(Unsafe_CopyMemory)},
    {CC"freeMemory",         CC"("ADR")V",               FN_PTR(Unsafe_FreeMemory)},

    {CC"objectFieldOffset",  CC"("FLD")J",               FN_PTR(Unsafe_ObjectFieldOffset)},
    {CC"staticFieldOffset",  CC"("FLD")J",               FN_PTR(Unsafe_StaticFieldOffset)},
    {CC"staticFieldBase",    CC"("FLD")"OBJ,             FN_PTR(Unsafe_StaticFieldBaseFromField)},
    {CC"ensureClassInitialized",CC"("CLS")V",            FN_PTR(Unsafe_EnsureClassInitialized)},
    {CC"arrayBaseOffset",    CC"("CLS")I",               FN_PTR(Unsafe_ArrayBaseOffset)},
    {CC"arrayIndexScale",    CC"("CLS")I",               FN_PTR(Unsafe_ArrayIndexScale)},
    {CC"addressSize",        CC"()I",                    FN_PTR(Unsafe_AddressSize)},
    {CC"pageSize",           CC"()I",                    FN_PTR(Unsafe_PageSize)},

    {CC"defineClass",        CC"("DC0_Args")"CLS,        FN_PTR(Unsafe_DefineClass0)},
    {CC"defineClass",        CC"("DC1_Args")"CLS,        FN_PTR(Unsafe_DefineClass1)},
    {CC"allocateInstance",   CC"("CLS")"OBJ,             FN_PTR(Unsafe_AllocateInstance)},
    {CC"monitorEnter",       CC"("OBJ")V",               FN_PTR(Unsafe_MonitorEnter)},
    {CC"monitorExit",        CC"("OBJ")V",               FN_PTR(Unsafe_MonitorExit)},
    {CC"throwException",     CC"("THR")V",               FN_PTR(Unsafe_ThrowException)},
    {CC"compareAndSwapObject", CC"("OBJ"J"OBJ""OBJ")Z",  FN_PTR(Unsafe_CompareAndSwapObject)},
    {CC"compareAndSwapInt",  CC"("OBJ"J""I""I"")Z",      FN_PTR(Unsafe_CompareAndSwapInt)},
    {CC"compareAndSwapLong", CC"("OBJ"J""J""J"")Z",      FN_PTR(Unsafe_CompareAndSwapLong)},
    {CC"park",               CC"(ZJ)V",                  FN_PTR(Unsafe_Park)},
    {CC"unpark",             CC"("OBJ")V",               FN_PTR(Unsafe_Unpark)}

};

// These are the correct methods, moving forward:
static JNINativeMethod methods[] = {

    {CC"getObject",        CC"("OBJ"J)"OBJ"",   FN_PTR(Unsafe_GetObject)},
    {CC"putObject",        CC"("OBJ"J"OBJ")V",  FN_PTR(Unsafe_SetObject)},
    {CC"getObjectVolatile",CC"("OBJ"J)"OBJ"",   FN_PTR(Unsafe_GetObjectVolatile)},
    {CC"putObjectVolatile",CC"("OBJ"J"OBJ")V",  FN_PTR(Unsafe_SetObjectVolatile)},


    DECLARE_GETSETOOP(Boolean, Z),
    DECLARE_GETSETOOP(Byte, B),
    DECLARE_GETSETOOP(Short, S),
    DECLARE_GETSETOOP(Char, C),
    DECLARE_GETSETOOP(Int, I),
    DECLARE_GETSETOOP(Long, J),
    DECLARE_GETSETOOP(Float, F),
    DECLARE_GETSETOOP(Double, D),

    DECLARE_GETSETNATIVE(Byte, B),
    DECLARE_GETSETNATIVE(Short, S),
    DECLARE_GETSETNATIVE(Char, C),
    DECLARE_GETSETNATIVE(Int, I),
    DECLARE_GETSETNATIVE(Long, J),
    DECLARE_GETSETNATIVE(Float, F),
    DECLARE_GETSETNATIVE(Double, D),

    {CC"getAddress",         CC"("ADR")"ADR,             FN_PTR(Unsafe_GetNativeAddress)},
    {CC"putAddress",         CC"("ADR""ADR")V",          FN_PTR(Unsafe_SetNativeAddress)},

    {CC"allocateMemory",     CC"(J)"ADR,                 FN_PTR(Unsafe_AllocateMemory)},
    {CC"reallocateMemory",   CC"("ADR"J)"ADR,            FN_PTR(Unsafe_ReallocateMemory)},
//  {CC"setMemory",          CC"("ADR"JB)V",             FN_PTR(Unsafe_SetMemory)},
//  {CC"copyMemory",         CC"("ADR ADR"J)V",          FN_PTR(Unsafe_CopyMemory)},
    {CC"freeMemory",         CC"("ADR")V",               FN_PTR(Unsafe_FreeMemory)},

    {CC"objectFieldOffset",  CC"("FLD")J",               FN_PTR(Unsafe_ObjectFieldOffset)},
    {CC"staticFieldOffset",  CC"("FLD")J",               FN_PTR(Unsafe_StaticFieldOffset)},
    {CC"staticFieldBase",    CC"("FLD")"OBJ,             FN_PTR(Unsafe_StaticFieldBaseFromField)},
    {CC"ensureClassInitialized",CC"("CLS")V",            FN_PTR(Unsafe_EnsureClassInitialized)},
    {CC"arrayBaseOffset",    CC"("CLS")I",               FN_PTR(Unsafe_ArrayBaseOffset)},
    {CC"arrayIndexScale",    CC"("CLS")I",               FN_PTR(Unsafe_ArrayIndexScale)},
    {CC"addressSize",        CC"()I",                    FN_PTR(Unsafe_AddressSize)},
    {CC"pageSize",           CC"()I",                    FN_PTR(Unsafe_PageSize)},

    {CC"defineClass",        CC"("DC0_Args")"CLS,        FN_PTR(Unsafe_DefineClass0)},
    {CC"defineClass",        CC"("DC1_Args")"CLS,        FN_PTR(Unsafe_DefineClass1)},
    {CC"allocateInstance",   CC"("CLS")"OBJ,             FN_PTR(Unsafe_AllocateInstance)},
    {CC"monitorEnter",       CC"("OBJ")V",               FN_PTR(Unsafe_MonitorEnter)},
    {CC"monitorExit",        CC"("OBJ")V",               FN_PTR(Unsafe_MonitorExit)},
    {CC"tryMonitorEnter",    CC"("OBJ")Z",               FN_PTR(Unsafe_TryMonitorEnter)},
    {CC"throwException",     CC"("THR")V",               FN_PTR(Unsafe_ThrowException)},
    {CC"compareAndSwapObject", CC"("OBJ"J"OBJ""OBJ")Z",  FN_PTR(Unsafe_CompareAndSwapObject)},
    {CC"compareAndSwapInt",  CC"("OBJ"J""I""I"")Z",      FN_PTR(Unsafe_CompareAndSwapInt)},
    {CC"compareAndSwapLong", CC"("OBJ"J""J""J"")Z",      FN_PTR(Unsafe_CompareAndSwapLong)},
    {CC"putOrderedObject",   CC"("OBJ"J"OBJ")V",         FN_PTR(Unsafe_SetOrderedObject)},
    {CC"putOrderedInt",      CC"("OBJ"JI)V",             FN_PTR(Unsafe_SetOrderedInt)},
    {CC"putOrderedLong",     CC"("OBJ"JJ)V",             FN_PTR(Unsafe_SetOrderedLong)},
    {CC"park",               CC"(ZJ)V",                  FN_PTR(Unsafe_Park)},
    {CC"unpark",             CC"("OBJ")V",               FN_PTR(Unsafe_Unpark)}

//    {CC"getLoadAverage",     CC"([DI)I",                 FN_PTR(Unsafe_Loadavg)},

//    {CC"prefetchRead",       CC"("OBJ"J)V",              FN_PTR(Unsafe_PrefetchRead)},
//    {CC"prefetchWrite",      CC"("OBJ"J)V",              FN_PTR(Unsafe_PrefetchWrite)}
//    {CC"prefetchReadStatic", CC"("OBJ"J)V",              FN_PTR(Unsafe_PrefetchRead)},
//    {CC"prefetchWriteStatic",CC"("OBJ"J)V",              FN_PTR(Unsafe_PrefetchWrite)}

};

JNINativeMethod loadavg_method[] = {
    {CC"getLoadAverage",            CC"([DI)I",                 FN_PTR(Unsafe_Loadavg)}
};

JNINativeMethod prefetch_methods[] = {
    {CC"prefetchRead",       CC"("OBJ"J)V",              FN_PTR(Unsafe_PrefetchRead)},
    {CC"prefetchWrite",      CC"("OBJ"J)V",              FN_PTR(Unsafe_PrefetchWrite)},
    {CC"prefetchReadStatic", CC"("OBJ"J)V",              FN_PTR(Unsafe_PrefetchRead)},
    {CC"prefetchWriteStatic",CC"("OBJ"J)V",              FN_PTR(Unsafe_PrefetchWrite)}
};

JNINativeMethod memcopy_methods[] = {
    {CC"copyMemory",         CC"("OBJ"J"OBJ"JJ)V",       FN_PTR(Unsafe_CopyMemory2)},
    {CC"setMemory",          CC"("OBJ"JJB)V",            FN_PTR(Unsafe_SetMemory2)}
};

JNINativeMethod memcopy_methods_15[] = {
    {CC"setMemory",          CC"("ADR"JB)V",             FN_PTR(Unsafe_SetMemory)},
    {CC"copyMemory",         CC"("ADR ADR"J)V",          FN_PTR(Unsafe_CopyMemory)}
};

JNINativeMethod anonk_methods[] = {
    {CC"defineAnonymousClass", CC"("DAC_Args")"CLS,      FN_PTR(Unsafe_DefineAnonymousClass)},
};

#undef CC
#undef FN_PTR

#undef ADR
#undef LANG
#undef OBJ
#undef CLS
#undef CTR
#undef FLD
#undef MTH
#undef THR
#undef DC0_Args
#undef DC1_Args

#undef DECLARE_GETSETOOP
#undef DECLARE_GETSETNATIVE


// This one function is exported, used by NativeLookup.
// The Unsafe_xxx functions above are called only from the interpreter.
// The optimizer looks at names and signatures to recognize
// individual functions.

JVM_ENTRY(void, JVM_RegisterUnsafeMethods(JNIEnv *env, jclass unsafecls))
  UnsafeWrapper("JVM_RegisterUnsafeMethods");
  {
    ThreadToNativeFromVM ttnfv(thread);
    {
      env->RegisterNatives(unsafecls, loadavg_method, sizeof(loadavg_method)/sizeof(JNINativeMethod));
      if (env->ExceptionOccurred()) {
        if (PrintMiscellaneous && (Verbose || WizardMode)) {
          tty->print_cr("Warning:  SDK 1.6 Unsafe.loadavg not found.");
        }
        env->ExceptionClear();
      }
    }
    {
      env->RegisterNatives(unsafecls, prefetch_methods, sizeof(prefetch_methods)/sizeof(JNINativeMethod));
      if (env->ExceptionOccurred()) {
        if (PrintMiscellaneous && (Verbose || WizardMode)) {
          tty->print_cr("Warning:  SDK 1.6 Unsafe.prefetchRead/Write not found.");
        }
        env->ExceptionClear();
      }
    }
    {
      env->RegisterNatives(unsafecls, memcopy_methods, sizeof(memcopy_methods)/sizeof(JNINativeMethod));
      if (env->ExceptionOccurred()) {
        if (PrintMiscellaneous && (Verbose || WizardMode)) {
          tty->print_cr("Warning:  SDK 1.7 Unsafe.copyMemory not found.");
        }
        env->ExceptionClear();
        env->RegisterNatives(unsafecls, memcopy_methods_15, sizeof(memcopy_methods_15)/sizeof(JNINativeMethod));
        if (env->ExceptionOccurred()) {
          if (PrintMiscellaneous && (Verbose || WizardMode)) {
            tty->print_cr("Warning:  SDK 1.5 Unsafe.copyMemory not found.");
          }
          env->ExceptionClear();
        }
      }
    }
    if (AnonymousClasses) {
      env->RegisterNatives(unsafecls, anonk_methods, sizeof(anonk_methods)/sizeof(JNINativeMethod));
      if (env->ExceptionOccurred()) {
        if (PrintMiscellaneous && (Verbose || WizardMode)) {
          tty->print_cr("Warning:  SDK 1.7 Unsafe.defineClass (anonymous version) not found.");
        }
        env->ExceptionClear();
      }
    }
    int status = env->RegisterNatives(unsafecls, methods, sizeof(methods)/sizeof(JNINativeMethod));
    if (env->ExceptionOccurred()) {
      if (PrintMiscellaneous && (Verbose || WizardMode)) {
        tty->print_cr("Warning:  SDK 1.6 version of Unsafe not found.");
      }
      env->ExceptionClear();
      // %%% For now, be backward compatible with an older class:
      status = env->RegisterNatives(unsafecls, methods_15, sizeof(methods_15)/sizeof(JNINativeMethod));
    }
    if (env->ExceptionOccurred()) {
      if (PrintMiscellaneous && (Verbose || WizardMode)) {
        tty->print_cr("Warning:  SDK 1.5 version of Unsafe not found.");
      }
      env->ExceptionClear();
      // %%% For now, be backward compatible with an older class:
      status = env->RegisterNatives(unsafecls, methods_141, sizeof(methods_141)/sizeof(JNINativeMethod));
    }
    if (env->ExceptionOccurred()) {
      if (PrintMiscellaneous && (Verbose || WizardMode)) {
        tty->print_cr("Warning:  SDK 1.4.1 version of Unsafe not found.");
      }
      env->ExceptionClear();
      // %%% For now, be backward compatible with an older class:
      status = env->RegisterNatives(unsafecls, methods_140, sizeof(methods_140)/sizeof(JNINativeMethod));
    }
    guarantee(status == 0, "register unsafe natives");
  }
JVM_END