corda/src/builtin.cpp

/* Copyright (c) 2008-2013, Avian Contributors

   Permission to use, copy, modify, and/or distribute this software
   for any purpose with or without fee is hereby granted, provided
   that the above copyright notice and this permission notice appear
   in all copies.

   There is NO WARRANTY for this software.  See license.txt for
   details. */

#include "avian/machine.h"
#include "avian/constants.h"
#include "avian/processor.h"
#include "avian/util.h"

#include <avian/util/runtime-array.h>

using namespace vm;

namespace {

int64_t
search(Thread* t, object loader, object name,
       object (*op)(Thread*, object, object), bool replaceDots)
{
  if (LIKELY(name)) {
    PROTECT(t, loader);
    PROTECT(t, name);

    object n = makeByteArray(t, stringLength(t, name) + 1);
    char* s = reinterpret_cast<char*>(&byteArrayBody(t, n, 0));
    stringChars(t, name, s);
    
    if (replaceDots) {
      replace('.', '/', s);
    }

    return reinterpret_cast<int64_t>(op(t, loader, n));
  } else {
    throwNew(t, Machine::NullPointerExceptionType);
  }
}

object
resolveSystemClassThrow(Thread* t, object loader, object spec)
{
  return resolveSystemClass
    (t, loader, spec, true, Machine::ClassNotFoundExceptionType);
}

object
fieldForOffsetInClass(Thread* t, object c, unsigned offset)
{
  object super = classSuper(t, c);
  if (super) {
    object field = fieldForOffsetInClass(t, super, offset);
    if (field) {
      return field;
    }
  }

  object table = classFieldTable(t, c);
  if (table) {
    for (unsigned i = 0; i < objectArrayLength(t, table); ++i) {
      object field = objectArrayBody(t, table, i);
      if ((fieldFlags(t, field) & ACC_STATIC) == 0
          and fieldOffset(t, field) == offset)
      {
        return field;
      }
    }
  }

  return 0;
}

object
fieldForOffset(Thread* t, object o, unsigned offset)
{
  object c = objectClass(t, o);
  if (classVmFlags(t, c) & SingletonFlag) {
    c = singletonObject(t, o, 0);
    object table = classFieldTable(t, c);
    if (table) {
      for (unsigned i = 0; i < objectArrayLength(t, table); ++i) {
        object field = objectArrayBody(t, table, i);
        if ((fieldFlags(t, field) & ACC_STATIC)
            and fieldOffset(t, field) == offset)
        {
          return field;
        }
      }
    }
    abort(t);
  } else {
    object field = fieldForOffsetInClass(t, c, offset);
    if (field) {
      return field;
    } else {
      abort(t);
    }
  }
}

} // namespace

extern "C" AVIAN_EXPORT void JNICALL
Avian_avian_Classes_initialize
(Thread* t, object, uintptr_t* arguments)
{
  object this_ = reinterpret_cast<object>(arguments[0]);

  initClass(t, this_);
}

extern "C" AVIAN_EXPORT void JNICALL
Avian_avian_Classes_acquireClassLock
(Thread* t, object, uintptr_t*)
{
  acquire(t, t->m->classLock);
}

extern "C" AVIAN_EXPORT void JNICALL
Avian_avian_Classes_releaseClassLock
(Thread* t, object, uintptr_t*)
{
  release(t, t->m->classLock);
}

extern "C" AVIAN_EXPORT int64_t JNICALL
Avian_avian_Classes_resolveVMClass
(Thread* t, object, uintptr_t* arguments)
{
  object loader = reinterpret_cast<object>(arguments[0]);
  object spec = reinterpret_cast<object>(arguments[1]);

  return reinterpret_cast<int64_t>
    (resolveClass(t, loader, spec, true, Machine::ClassNotFoundExceptionType));
}

extern "C" AVIAN_EXPORT int64_t JNICALL
Avian_avian_Classes_defineVMClass
(Thread* t, object, uintptr_t* arguments)
{
  object loader = reinterpret_cast<object>(arguments[0]);
  object b = reinterpret_cast<object>(arguments[1]);
  int offset = arguments[2];
  int length = arguments[3];

  uint8_t* buffer = static_cast<uint8_t*>
    (t->m->heap->allocate(length));
  
  THREAD_RESOURCE2(t, uint8_t*, buffer, int, length,
                   t->m->heap->free(buffer, length));

  memcpy(buffer, &byteArrayBody(t, b, offset), length);

  return reinterpret_cast<int64_t>(defineClass(t, loader, buffer, length));
}

extern "C" AVIAN_EXPORT int64_t JNICALL
Avian_avian_SystemClassLoader_findLoadedVMClass
(Thread* t, object, uintptr_t* arguments)
{
  object loader = reinterpret_cast<object>(arguments[0]);
  object name = reinterpret_cast<object>(arguments[1]);

  return search(t, loader, name, findLoadedClass, true);
}

extern "C" AVIAN_EXPORT int64_t JNICALL
Avian_avian_SystemClassLoader_vmClass
(Thread* t, object, uintptr_t* arguments)
{
  return reinterpret_cast<int64_t>
    (jclassVmClass(t, reinterpret_cast<object>(arguments[0])));
}

extern "C" AVIAN_EXPORT int64_t JNICALL
Avian_avian_SystemClassLoader_findVMClass
(Thread* t, object, uintptr_t* arguments)
{
  object loader = reinterpret_cast<object>(arguments[0]);
  object name = reinterpret_cast<object>(arguments[1]);

  return search(t, loader, name, resolveSystemClassThrow, true);
}

extern "C" AVIAN_EXPORT int64_t JNICALL
Avian_avian_SystemClassLoader_resourceURLPrefix
(Thread* t, object, uintptr_t* arguments)
{
  object loader = reinterpret_cast<object>(arguments[0]);
  object name = reinterpret_cast<object>(arguments[1]);

  if (LIKELY(name)) {
    THREAD_RUNTIME_ARRAY(t, char, n, stringLength(t, name) + 1);
    stringChars(t, name, RUNTIME_ARRAY_BODY(n));

    const char* name = static_cast<Finder*>
      (systemClassLoaderFinder(t, loader))->urlPrefix(RUNTIME_ARRAY_BODY(n));

    return name ? reinterpret_cast<uintptr_t>(makeString(t, "%s", name)) : 0;
  } else {
    throwNew(t, Machine::NullPointerExceptionType);
  }
}

extern "C" AVIAN_EXPORT int64_t JNICALL
Avian_avian_SystemClassLoader_00024ResourceEnumeration_nextResourceURLPrefix
(Thread* t, object, uintptr_t* arguments)
{
  object loader = reinterpret_cast<object>(arguments[1]);
  object name = reinterpret_cast<object>(arguments[2]);
  object finderElementPtrPtr = reinterpret_cast<object>(arguments[3]);

  if (LIKELY(name) && LIKELY(finderElementPtrPtr)) {
    THREAD_RUNTIME_ARRAY(t, char, n, stringLength(t, name) + 1);
    stringChars(t, name, RUNTIME_ARRAY_BODY(n));

    void *&finderElementPtr = reinterpret_cast<void *&>(longArrayBody(t,
      finderElementPtrPtr, 0));
    const char* name = static_cast<Finder*>
      (systemClassLoaderFinder(t, loader))->nextUrlPrefix(RUNTIME_ARRAY_BODY(n),
        finderElementPtr);

    return name ? reinterpret_cast<uintptr_t>(makeString(t, "%s", name)) : 0;
  } else {
    throwNew(t, Machine::NullPointerExceptionType);
  }
}

extern "C" AVIAN_EXPORT int64_t JNICALL
Avian_avian_SystemClassLoader_getClass
(Thread* t, object, uintptr_t* arguments)
{
  return reinterpret_cast<int64_t>
    (getJClass(t, reinterpret_cast<object>(arguments[0])));
}

#ifdef AVIAN_HEAPDUMP

extern "C" AVIAN_EXPORT void JNICALL
Avian_avian_Machine_dumpHeap
(Thread* t, object, uintptr_t* arguments)
{
  object outputFile = reinterpret_cast<object>(*arguments);

  unsigned length = stringLength(t, outputFile);
  THREAD_RUNTIME_ARRAY(t, char, n, length + 1);
  stringChars(t, outputFile, RUNTIME_ARRAY_BODY(n));
  FILE* out = vm::fopen(RUNTIME_ARRAY_BODY(n), "wb");
  if (out) {
    { ENTER(t, Thread::ExclusiveState);
      dumpHeap(t, out);
    }
    fclose(out);
  } else {
    throwNew(t, Machine::RuntimeExceptionType, "file not found: %s",
             RUNTIME_ARRAY_BODY(n));
  }
}

#endif//AVIAN_HEAPDUMP

extern "C" AVIAN_EXPORT void JNICALL
Avian_java_lang_Runtime_exit
(Thread* t, object, uintptr_t* arguments)
{
  shutDown(t);

  t->m->system->exit(arguments[1]);
}

extern "C" AVIAN_EXPORT int64_t JNICALL
Avian_avian_avianvmresource_Handler_00024ResourceInputStream_getContentLength
(Thread* t, object, uintptr_t* arguments)
{
  object path = reinterpret_cast<object>(*arguments);

  if (LIKELY(path)) {
    THREAD_RUNTIME_ARRAY(t, char, p, stringLength(t, path) + 1);
    stringChars(t, path, RUNTIME_ARRAY_BODY(p));

    System::Region* r = t->m->bootFinder->find(RUNTIME_ARRAY_BODY(p));
    if (r == 0) {
      r = t->m->appFinder->find(RUNTIME_ARRAY_BODY(p));
    }

    if (r) {
      jint rSize = r->length();
      r->dispose();
      return rSize;
    }
  }
  return -1;
}

extern "C" AVIAN_EXPORT int64_t JNICALL
Avian_avian_avianvmresource_Handler_00024ResourceInputStream_open
(Thread* t, object, uintptr_t* arguments)
{
  object path = reinterpret_cast<object>(*arguments);

  if (LIKELY(path)) {
    THREAD_RUNTIME_ARRAY(t, char, p, stringLength(t, path) + 1);
    stringChars(t, path, RUNTIME_ARRAY_BODY(p));

    System::Region* r = t->m->bootFinder->find(RUNTIME_ARRAY_BODY(p));
    if (r == 0) {
      r = t->m->appFinder->find(RUNTIME_ARRAY_BODY(p));
    }

    return reinterpret_cast<int64_t>(r);
  } else {
    throwNew(t, Machine::NullPointerExceptionType);
  }
}

extern "C" AVIAN_EXPORT int64_t JNICALL
Avian_avian_avianvmresource_Handler_00024ResourceInputStream_available
(Thread*, object, uintptr_t* arguments)
{
  int64_t peer; memcpy(&peer, arguments, 8);
  int32_t position = arguments[2];

  System::Region* region = reinterpret_cast<System::Region*>(peer);
  return static_cast<jint>(region->length()) - position;
}

extern "C" AVIAN_EXPORT int64_t JNICALL
Avian_avian_avianvmresource_Handler_00024ResourceInputStream_read__JI
(Thread*, object, uintptr_t* arguments)
{
  int64_t peer; memcpy(&peer, arguments, 8);
  int32_t position = arguments[2];

  System::Region* region = reinterpret_cast<System::Region*>(peer);
  if (position >= static_cast<jint>(region->length())) {
    return -1;
  } else {
    return region->start()[position];
  }
}

extern "C" AVIAN_EXPORT int64_t JNICALL
Avian_avian_avianvmresource_Handler_00024ResourceInputStream_read__JI_3BII
(Thread* t, object, uintptr_t* arguments)
{
  int64_t peer; memcpy(&peer, arguments, 8);
  int32_t position = arguments[2];
  object buffer = reinterpret_cast<object>(arguments[3]);
  int32_t offset = arguments[4];
  int32_t length = arguments[5];

  if (length == 0) return 0;
  
  System::Region* region = reinterpret_cast<System::Region*>(peer);
  if (length > static_cast<jint>(region->length()) - position) {
    length = static_cast<jint>(region->length()) - position;
  }
  if (length <= 0) {
    return -1;
  } else {
    memcpy(&byteArrayBody(t, buffer, offset), region->start() + position,
           length);
    return length;
  }
}

extern "C" AVIAN_EXPORT void JNICALL
Avian_avian_avianvmresource_Handler_00024ResourceInputStream_close
(Thread*, object, uintptr_t* arguments)
{
  int64_t peer; memcpy(&peer, arguments, 8);
  reinterpret_cast<System::Region*>(peer)->dispose();
}

extern "C" AVIAN_EXPORT void JNICALL
Avian_avian_Continuations_callWithCurrentContinuation
(Thread* t, object, uintptr_t* arguments)
{
  t->m->processor->callWithCurrentContinuation
    (t, reinterpret_cast<object>(*arguments));

  abort(t);
}

extern "C" AVIAN_EXPORT void JNICALL
Avian_avian_Continuations_dynamicWind2
(Thread* t, object, uintptr_t* arguments)
{
  t->m->processor->dynamicWind
    (t, reinterpret_cast<object>(arguments[0]),
     reinterpret_cast<object>(arguments[1]),
     reinterpret_cast<object>(arguments[2]));

  abort(t);
}

extern "C" AVIAN_EXPORT void JNICALL
Avian_avian_Continuations_00024Continuation_handleResult
(Thread* t, object, uintptr_t* arguments)
{
  t->m->processor->feedResultToContinuation
    (t, reinterpret_cast<object>(arguments[0]),
     reinterpret_cast<object>(arguments[1]));

  abort(t);
}

extern "C" AVIAN_EXPORT void JNICALL
Avian_avian_Continuations_00024Continuation_handleException
(Thread* t, object, uintptr_t* arguments)
{
  t->m->processor->feedExceptionToContinuation
    (t, reinterpret_cast<object>(arguments[0]),
     reinterpret_cast<object>(arguments[1]));

  abort(t);
}

extern "C" AVIAN_EXPORT int64_t JNICALL
Avian_avian_Singleton_getObject
(Thread* t, object, uintptr_t* arguments)
{
  return reinterpret_cast<int64_t>
    (singletonObject(t, reinterpret_cast<object>(arguments[0]), arguments[1]));
}

extern "C" AVIAN_EXPORT int64_t JNICALL
Avian_avian_Singleton_getInt
(Thread* t, object, uintptr_t* arguments)
{
  return singletonValue
    (t, reinterpret_cast<object>(arguments[0]), arguments[1]);
}

extern "C" AVIAN_EXPORT int64_t JNICALL
Avian_avian_Singleton_getLong
(Thread* t, object, uintptr_t* arguments)
{
  int64_t v;
  memcpy(&v, &singletonValue
         (t, reinterpret_cast<object>(arguments[0]), arguments[1]), 8);
  return v;
}

extern "C" AVIAN_EXPORT int64_t JNICALL
Avian_sun_misc_Unsafe_allocateMemory
(Thread* t, object, uintptr_t* arguments)
{
  int64_t size; memcpy(&size, arguments + 1, 8);
  void* p = malloc(size);
  if (p) {
    return reinterpret_cast<int64_t>(p);
  } else {
    throwNew(t, Machine::OutOfMemoryErrorType);
  }
}

extern "C" AVIAN_EXPORT void JNICALL
Avian_sun_misc_Unsafe_freeMemory
(Thread*, object, uintptr_t* arguments)
{
  int64_t p; memcpy(&p, arguments + 1, 8);
  if (p) {
    free(reinterpret_cast<void*>(p));
  }
}

extern "C" AVIAN_EXPORT void JNICALL
Avian_sun_misc_Unsafe_setMemory
(Thread* t, object, uintptr_t* arguments)
{
  object base = reinterpret_cast<object>(arguments[1]);
  int64_t offset; memcpy(&offset, arguments + 2, 8);
  int64_t count; memcpy(&count, arguments + 4, 8);
  int8_t value = arguments[6];

  PROTECT(t, base);

  ACQUIRE(t, t->m->referenceLock);

  if (base) {
    memset(&fieldAtOffset<int8_t>(base, offset), value, count);
  } else {
    memset(reinterpret_cast<int8_t*>(offset), value, count);
  }
}

// NB: The following primitive get/put methods are only used by the
// interpreter.  The JIT/AOT compiler implements them as intrinsics,
// so these versions will be ignored.

extern "C" AVIAN_EXPORT void JNICALL
Avian_sun_misc_Unsafe_putByte__JB
(Thread*, object, uintptr_t* arguments)
{
  int64_t p; memcpy(&p, arguments + 1, 8);
  int8_t v = arguments[3];

  *reinterpret_cast<int8_t*>(p) = v;
}

extern "C" AVIAN_EXPORT void JNICALL
Avian_sun_misc_Unsafe_putShort__JS
(Thread*, object, uintptr_t* arguments)
{
  int64_t p; memcpy(&p, arguments + 1, 8);
  int16_t v = arguments[3];

  *reinterpret_cast<int16_t*>(p) = v;
}

extern "C" AVIAN_EXPORT void JNICALL
Avian_sun_misc_Unsafe_putChar__JC
(Thread* t, object method, uintptr_t* arguments)
{
  Avian_sun_misc_Unsafe_putShort__JS(t, method, arguments);
}

extern "C" AVIAN_EXPORT void JNICALL
Avian_sun_misc_Unsafe_putInt__JI
(Thread*, object, uintptr_t* arguments)
{
  int64_t p; memcpy(&p, arguments + 1, 8);
  int32_t v = arguments[3];

  *reinterpret_cast<int32_t*>(p) = v;
}

extern "C" AVIAN_EXPORT void JNICALL
Avian_sun_misc_Unsafe_putFloat__JF
(Thread* t, object method, uintptr_t* arguments)
{
  Avian_sun_misc_Unsafe_putInt__JI(t, method, arguments);
}

extern "C" AVIAN_EXPORT void JNICALL
Avian_sun_misc_Unsafe_putLong__JJ
(Thread*, object, uintptr_t* arguments)
{
  int64_t p; memcpy(&p, arguments + 1, 8);
  int64_t v; memcpy(&v, arguments + 3, 8);

  *reinterpret_cast<int64_t*>(p) = v;
}

extern "C" AVIAN_EXPORT void JNICALL
Avian_sun_misc_Unsafe_putDouble__JD
(Thread* t, object method, uintptr_t* arguments)
{
  Avian_sun_misc_Unsafe_putLong__JJ(t, method, arguments);
}

extern "C" AVIAN_EXPORT void JNICALL
Avian_sun_misc_Unsafe_putAddress__JJ
(Thread*, object, uintptr_t* arguments)
{
  int64_t p; memcpy(&p, arguments + 1, 8);
  int64_t v; memcpy(&v, arguments + 3, 8);

  *reinterpret_cast<intptr_t*>(p) = v;
}

extern "C" AVIAN_EXPORT int64_t JNICALL
Avian_sun_misc_Unsafe_getByte__J
(Thread*, object, uintptr_t* arguments)
{
  int64_t p; memcpy(&p, arguments + 1, 8);

  return *reinterpret_cast<int8_t*>(p);
}

extern "C" AVIAN_EXPORT int64_t JNICALL
Avian_sun_misc_Unsafe_getShort__J
(Thread*, object, uintptr_t* arguments)
{
  int64_t p; memcpy(&p, arguments + 1, 8);

  return *reinterpret_cast<int16_t*>(p);
}

extern "C" AVIAN_EXPORT int64_t JNICALL
Avian_sun_misc_Unsafe_getChar__J
(Thread* t, object method, uintptr_t* arguments)
{
  return Avian_sun_misc_Unsafe_getShort__J(t, method, arguments);
}

extern "C" AVIAN_EXPORT int64_t JNICALL
Avian_sun_misc_Unsafe_getInt__J
(Thread*, object, uintptr_t* arguments)
{
  int64_t p; memcpy(&p, arguments + 1, 8);

  return *reinterpret_cast<int32_t*>(p);
}

extern "C" AVIAN_EXPORT int64_t JNICALL
Avian_sun_misc_Unsafe_getFloat__J
(Thread* t, object method, uintptr_t* arguments)
{
  return Avian_sun_misc_Unsafe_getInt__J(t, method, arguments);
}

extern "C" AVIAN_EXPORT int64_t JNICALL
Avian_sun_misc_Unsafe_getLong__J
(Thread*, object, uintptr_t* arguments)
{
  int64_t p; memcpy(&p, arguments + 1, 8);

  return *reinterpret_cast<int64_t*>(p);
}

extern "C" AVIAN_EXPORT int64_t JNICALL
Avian_sun_misc_Unsafe_getDouble__J
(Thread* t, object method, uintptr_t* arguments)
{
  return Avian_sun_misc_Unsafe_getLong__J(t, method, arguments);
}

extern "C" AVIAN_EXPORT int64_t JNICALL
Avian_sun_misc_Unsafe_getAddress__J
(Thread*, object, uintptr_t* arguments)
{
  int64_t p; memcpy(&p, arguments + 1, 8);

  return *reinterpret_cast<intptr_t*>(p);
}

extern "C" AVIAN_EXPORT void JNICALL
Avian_sun_misc_Unsafe_copyMemory
(Thread* t, object, uintptr_t* arguments)
{
  object srcBase = reinterpret_cast<object>(arguments[1]);
  int64_t srcOffset; memcpy(&srcOffset, arguments + 2, 8);
  object dstBase = reinterpret_cast<object>(arguments[4]);
  int64_t dstOffset; memcpy(&dstOffset, arguments + 5, 8);
  int64_t count; memcpy(&count, arguments + 7, 8);

  PROTECT(t, srcBase);
  PROTECT(t, dstBase);

  ACQUIRE(t, t->m->referenceLock);

  void* src = srcBase
    ? &fieldAtOffset<uint8_t>(srcBase, srcOffset)
    : reinterpret_cast<uint8_t*>(srcOffset);

  void* dst = dstBase
    ? &fieldAtOffset<uint8_t>(dstBase, dstOffset)
    : reinterpret_cast<uint8_t*>(dstOffset);

  memcpy(dst, src, count);
}

extern "C" AVIAN_EXPORT int64_t JNICALL
Avian_sun_misc_Unsafe_arrayBaseOffset
(Thread*, object, uintptr_t*)
{
  return ArrayBody;
}

extern "C" AVIAN_EXPORT int64_t JNICALL
Avian_java_nio_FixedArrayByteBuffer_allocateFixed
(Thread* t, object, uintptr_t* arguments)
{
  int capacity = arguments[0];
  object address = reinterpret_cast<object>(arguments[1]);
  PROTECT(t, address);

  object array = allocate3
    (t, t->m->heap, Machine::FixedAllocation, ArrayBody + capacity, false);

  setObjectClass(t, array, type(t, Machine::ByteArrayType));
  byteArrayLength(t, array) = capacity;

  longArrayBody(t, address, 0) = reinterpret_cast<intptr_t>(array) + ArrayBody;

  return reinterpret_cast<intptr_t>(array);
}

extern "C" AVIAN_EXPORT int64_t JNICALL
Avian_sun_misc_Unsafe_getObject
(Thread*, object, uintptr_t* arguments)
{
  object o = reinterpret_cast<object>(arguments[1]);
  int64_t offset; memcpy(&offset, arguments + 2, 8);

  return fieldAtOffset<uintptr_t>(o, offset);
}

extern "C" AVIAN_EXPORT void JNICALL
Avian_sun_misc_Unsafe_putObject
(Thread* t, object, uintptr_t* arguments)
{
  object o = reinterpret_cast<object>(arguments[1]);
  int64_t offset; memcpy(&offset, arguments + 2, 8);
  uintptr_t value = arguments[4];

  set(t, o, offset, reinterpret_cast<object>(value));
}

extern "C" AVIAN_EXPORT void JNICALL
Avian_sun_misc_Unsafe_putObjectVolatile
(Thread* t, object, uintptr_t* arguments)
{
  object o = reinterpret_cast<object>(arguments[1]);
  int64_t offset; memcpy(&offset, arguments + 2, 8);
  object value = reinterpret_cast<object>(arguments[4]);
  
  storeStoreMemoryBarrier();
  set(t, o, offset, reinterpret_cast<object>(value));
  storeLoadMemoryBarrier();
}

extern "C" AVIAN_EXPORT void JNICALL
Avian_sun_misc_Unsafe_putOrderedObject
(Thread* t, object method, uintptr_t* arguments)
{
  Avian_sun_misc_Unsafe_putObjectVolatile(t, method, arguments);
}

extern "C" AVIAN_EXPORT int64_t JNICALL
Avian_sun_misc_Unsafe_getObjectVolatile
(Thread*, object, uintptr_t* arguments)
{
  object o = reinterpret_cast<object>(arguments[1]);
  int64_t offset; memcpy(&offset, arguments + 2, 8);
  
  uintptr_t value = fieldAtOffset<uintptr_t>(o, offset);
  loadMemoryBarrier();
  return value;
}

extern "C" AVIAN_EXPORT int64_t JNICALL
Avian_sun_misc_Unsafe_compareAndSwapObject
(Thread* t, object, uintptr_t* arguments)
{
  object target = reinterpret_cast<object>(arguments[1]);
  int64_t offset; memcpy(&offset, arguments + 2, 8);
  uintptr_t expect = arguments[4];
  uintptr_t update = arguments[5];

  bool success = atomicCompareAndSwap
    (&fieldAtOffset<uintptr_t>(target, offset), expect, update);

  if (success) {
    mark(t, target, offset);
  }

  return success;
}

extern "C" AVIAN_EXPORT int64_t JNICALL
Avian_sun_misc_Unsafe_compareAndSwapInt
(Thread*, object, uintptr_t* arguments)
{
  object target = reinterpret_cast<object>(arguments[1]);
  int64_t offset; memcpy(&offset, arguments + 2, 8);
  uint32_t expect = arguments[4];
  uint32_t update = arguments[5];

  return atomicCompareAndSwap32
    (&fieldAtOffset<uint32_t>(target, offset), expect, update);
}

extern "C" AVIAN_EXPORT int64_t JNICALL
Avian_sun_misc_Unsafe_compareAndSwapLong
(Thread* t UNUSED, object, uintptr_t* arguments)
{
  object target = reinterpret_cast<object>(arguments[1]);
  int64_t offset; memcpy(&offset, arguments + 2, 8);
  uint64_t expect; memcpy(&expect, arguments + 4, 8);
  uint64_t update; memcpy(&update, arguments + 6, 8);

#ifdef AVIAN_HAS_CAS64
  return atomicCompareAndSwap64
    (&fieldAtOffset<uint64_t>(target, offset), expect, update);
#else
  ACQUIRE_FIELD_FOR_WRITE(t, fieldForOffset(t, target, offset));
  if (fieldAtOffset<uint64_t>(target, offset) == expect) {
    fieldAtOffset<uint64_t>(target, offset) = update;
    return true;
  } else {
    return false;
  }
#endif
}

extern "C" AVIAN_EXPORT int64_t JNICALL
Avian_sun_misc_Unsafe_getLongVolatile
(Thread* t, object, uintptr_t* arguments)
{
  object o = reinterpret_cast<object>(arguments[1]);
  int64_t offset; memcpy(&offset, arguments + 2, 8);

  object field;
  if (BytesPerWord < 8) {
    field = fieldForOffset(t, o, offset);

    PROTECT(t, field);
    acquire(t, field);        
  }

  int64_t result = fieldAtOffset<int64_t>(o, offset);

  if (BytesPerWord < 8) {
    release(t, field);        
  } else {
    loadMemoryBarrier();
  }

  return result;
}

extern "C" AVIAN_EXPORT void JNICALL
Avian_sun_misc_Unsafe_putLongVolatile
(Thread* t, object, uintptr_t* arguments)
{
  object o = reinterpret_cast<object>(arguments[1]);
  int64_t offset; memcpy(&offset, arguments + 2, 8);
  int64_t value; memcpy(&value, arguments + 4, 8);

  object field;
  if (BytesPerWord < 8) {
    field = fieldForOffset(t, o, offset);

    PROTECT(t, field);
    acquire(t, field);        
  } else {
    storeStoreMemoryBarrier();
  }

  fieldAtOffset<int64_t>(o, offset) = value;

  if (BytesPerWord < 8) {
    release(t, field);
  } else {
    storeLoadMemoryBarrier();
  }
}

extern "C" AVIAN_EXPORT void JNICALL
Avian_sun_misc_Unsafe_putOrderedLong
(Thread* t, object method, uintptr_t* arguments)
{
  // todo: we might be able to use weaker barriers here than
  // putLongVolatile does
  Avian_sun_misc_Unsafe_putLongVolatile(t, method, arguments);
}

extern "C" AVIAN_EXPORT void JNICALL
Avian_sun_misc_Unsafe_unpark
(Thread* t, object, uintptr_t* arguments)
{
  object thread = reinterpret_cast<object>(arguments[1]);
  
  monitorAcquire(t, interruptLock(t, thread));
  threadUnparked(t, thread) = true;
  monitorNotify(t, interruptLock(t, thread));
  monitorRelease(t, interruptLock(t, thread));
}

extern "C" AVIAN_EXPORT void JNICALL
Avian_sun_misc_Unsafe_park
(Thread* t, object, uintptr_t* arguments)
{
  bool absolute = arguments[1];
  int64_t time; memcpy(&time, arguments + 2, 8);
  
  int64_t then = t->m->system->now();

  if (absolute) {
    time -= then;
    if (time <= 0) {
      return;
    }
  } else if (time) {
    // if not absolute, interpret time as nanoseconds, but make sure
    // it doesn't become zero when we convert to milliseconds, since
    // zero is interpreted as infinity below
    time = (time / (1000 * 1000)) + 1;
  }

  monitorAcquire(t, interruptLock(t, t->javaThread));
  bool interrupted = false;
  while (time >= 0
         and (not (threadUnparked(t, t->javaThread)
                   or threadInterrupted(t, t->javaThread)
                   or (interrupted = monitorWait
                       (t, interruptLock(t, t->javaThread), time)))))
  {
    int64_t now = t->m->system->now();
    time -= now - then;
    then = now;
    
    if (time == 0) {
      break;
    }
  }
  if (interrupted) {
    threadInterrupted(t, t->javaThread) = true;
  }
  threadUnparked(t, t->javaThread) = false;
  monitorRelease(t, interruptLock(t, t->javaThread));
}

extern "C" AVIAN_EXPORT void JNICALL
Avian_sun_misc_Unsafe_putIntVolatile
(Thread*, object, uintptr_t* arguments)
{
  object o = reinterpret_cast<object>(arguments[1]);
  int64_t offset; memcpy(&offset, arguments + 2, 8);
  int32_t value = arguments[4];
  
  storeStoreMemoryBarrier();
  fieldAtOffset<int32_t>(o, offset) = value;
  storeLoadMemoryBarrier();
}

extern "C" AVIAN_EXPORT void JNICALL
Avian_sun_misc_Unsafe_putOrderedInt
(Thread* t, object method, uintptr_t* arguments)
{
  Avian_sun_misc_Unsafe_putIntVolatile(t, method, arguments);
}

extern "C" AVIAN_EXPORT int64_t JNICALL
Avian_sun_misc_Unsafe_getIntVolatile
(Thread*, object, uintptr_t* arguments)
{
  object o = reinterpret_cast<object>(arguments[1]);
  int64_t offset; memcpy(&offset, arguments + 2, 8);

  int32_t result = fieldAtOffset<int32_t>(o, offset);
  loadMemoryBarrier();
  return result;
}

extern "C" AVIAN_EXPORT void JNICALL
Avian_sun_misc_Unsafe_throwException
(Thread* t, object, uintptr_t* arguments)
{
  vm::throw_(t, reinterpret_cast<object>(arguments[1]));
}

extern "C" AVIAN_EXPORT int64_t JNICALL
Avian_avian_Classes_primitiveClass
(Thread* t, object, uintptr_t* arguments)
{
  return reinterpret_cast<int64_t>(primitiveClass(t, arguments[0]));
}