1 /*
   2  * Copyright (c) 2000, 2019, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #include "precompiled.hpp"
  26 #include "jni.h"
  27 #include "jvm.h"
  28 #include "classfile/classFileStream.hpp"
  29 #include "classfile/classLoader.hpp"
  30 #include "classfile/vmSymbols.hpp"
  31 #include "jfr/jfrEvents.hpp"
  32 #include "memory/allocation.inline.hpp"
  33 #include "memory/resourceArea.hpp"
  34 #include "oops/access.inline.hpp"
  35 #include "oops/fieldStreams.inline.hpp"
  36 #include "oops/objArrayOop.inline.hpp"
  37 #include "oops/oop.inline.hpp"
  38 #include "oops/typeArrayOop.inline.hpp"
  39 #include "prims/unsafe.hpp"
  40 #include "runtime/globals.hpp"
  41 #include "runtime/handles.inline.hpp"
  42 #include "runtime/interfaceSupport.inline.hpp"
  43 #include "runtime/jniHandles.inline.hpp"
  44 #include "runtime/orderAccess.hpp"
  45 #include "runtime/reflection.hpp"
  46 #include "runtime/sharedRuntime.hpp"
  47 #include "runtime/thread.hpp"
  48 #include "runtime/threadSMR.hpp"
  49 #include "runtime/vm_version.hpp"
  50 #include "services/threadService.hpp"
  51 #include "utilities/align.hpp"
  52 #include "utilities/copy.hpp"
  53 #include "utilities/dtrace.hpp"
  54 #include "utilities/macros.hpp"
  55 
  56 /**
  57  * Implementation of the jdk.internal.misc.Unsafe class
  58  */
  59 
  60 
  61 #define MAX_OBJECT_SIZE \
  62   ( arrayOopDesc::header_size(T_DOUBLE) * HeapWordSize \
  63     + ((julong)max_jint * sizeof(double)) )
  64 
  65 
  66 #define UNSAFE_ENTRY(result_type, header) \
  67   JVM_ENTRY(static result_type, header)
  68 
  69 #define UNSAFE_LEAF(result_type, header) \
  70   JVM_LEAF(static result_type, header)
  71 
  72 #define UNSAFE_END JVM_END
  73 
  74 
  75 static inline void* addr_from_java(jlong addr) {
  76   // This assert fails in a variety of ways on 32-bit systems.
  77   // It is impossible to predict whether native code that converts
  78   // pointers to longs will sign-extend or zero-extend the addresses.
  79   //assert(addr == (uintptr_t)addr, "must not be odd high bits");
  80   return (void*)(uintptr_t)addr;
  81 }
  82 
  83 static inline jlong addr_to_java(void* p) {
  84   assert(p == (void*)(uintptr_t)p, "must not be odd high bits");
  85   return (uintptr_t)p;
  86 }
  87 
  88 
  89 // Note: The VM's obj_field and related accessors use byte-scaled
  90 // ("unscaled") offsets, just as the unsafe methods do.
  91 
  92 // However, the method Unsafe.fieldOffset explicitly declines to
  93 // guarantee this.  The field offset values manipulated by the Java user
  94 // through the Unsafe API are opaque cookies that just happen to be byte
  95 // offsets.  We represent this state of affairs by passing the cookies
  96 // through conversion functions when going between the VM and the Unsafe API.
  97 // The conversion functions just happen to be no-ops at present.
  98 
  99 static inline jlong field_offset_to_byte_offset(jlong field_offset) {
 100   return field_offset;
 101 }
 102 
 103 static inline jlong field_offset_from_byte_offset(jlong byte_offset) {
 104   return byte_offset;
 105 }
 106 
 107 static inline void assert_field_offset_sane(oop p, jlong field_offset) {
 108 #ifdef ASSERT
 109   jlong byte_offset = field_offset_to_byte_offset(field_offset);
 110 
 111   if (p != NULL) {
 112     assert(byte_offset >= 0 && byte_offset <= (jlong)MAX_OBJECT_SIZE, "sane offset");
 113     if (byte_offset == (jint)byte_offset) {
 114       void* ptr_plus_disp = cast_from_oop<address>(p) + byte_offset;
 115       assert(p->field_addr_raw((jint)byte_offset) == ptr_plus_disp,
 116              "raw [ptr+disp] must be consistent with oop::field_addr_raw");
 117     }
 118     jlong p_size = HeapWordSize * (jlong)(p->size());
 119     assert(byte_offset < p_size, "Unsafe access: offset " INT64_FORMAT " > object's size " INT64_FORMAT, (int64_t)byte_offset, (int64_t)p_size);
 120   }
 121 #endif
 122 }
 123 
 124 static inline void* index_oop_from_field_offset_long(oop p, jlong field_offset) {
 125   assert_field_offset_sane(p, field_offset);
 126   jlong byte_offset = field_offset_to_byte_offset(field_offset);
 127 
 128   if (p != NULL) {
 129     p = Access<>::resolve(p);
 130   }
 131 
 132   if (sizeof(char*) == sizeof(jint)) {   // (this constant folds!)
 133     return cast_from_oop<address>(p) + (jint) byte_offset;
 134   } else {
 135     return cast_from_oop<address>(p) +        byte_offset;
 136   }
 137 }
 138 
 139 // Externally callable versions:
 140 // (Use these in compiler intrinsics which emulate unsafe primitives.)
 141 jlong Unsafe_field_offset_to_byte_offset(jlong field_offset) {
 142   return field_offset;
 143 }
 144 jlong Unsafe_field_offset_from_byte_offset(jlong byte_offset) {
 145   return byte_offset;
 146 }
 147 
 148 
 149 ///// Data read/writes on the Java heap and in native (off-heap) memory
 150 
 151 /**
 152  * Helper class to wrap memory accesses in JavaThread::doing_unsafe_access()
 153  */
 154 class GuardUnsafeAccess {
 155   JavaThread* _thread;
 156 
 157 public:
 158   GuardUnsafeAccess(JavaThread* thread) : _thread(thread) {
 159     // native/off-heap access which may raise SIGBUS if accessing
 160     // memory mapped file data in a region of the file which has
 161     // been truncated and is now invalid.
 162     _thread->set_doing_unsafe_access(true);
 163   }
 164 
 165   ~GuardUnsafeAccess() {
 166     _thread->set_doing_unsafe_access(false);
 167   }
 168 };
 169 
 170 /**
 171  * Helper class for accessing memory.
 172  *
 173  * Normalizes values and wraps accesses in
 174  * JavaThread::doing_unsafe_access() if needed.
 175  */
 176 template <typename T>
 177 class MemoryAccess : StackObj {
 178   JavaThread* _thread;
 179   oop _obj;
 180   ptrdiff_t _offset;
 181 
 182   // Resolves and returns the address of the memory access.
 183   // This raw memory access may fault, so we make sure it happens within the
 184   // guarded scope by making the access volatile at least. Since the store
 185   // of Thread::set_doing_unsafe_access() is also volatile, these accesses
 186   // can not be reordered by the compiler. Therefore, if the access triggers
 187   // a fault, we will know that Thread::doing_unsafe_access() returns true.
 188   volatile T* addr() {
 189     void* addr = index_oop_from_field_offset_long(_obj, _offset);
 190     return static_cast<volatile T*>(addr);
 191   }
 192 
 193   template <typename U>
 194   U normalize_for_write(U x) {
 195     return x;
 196   }
 197 
 198   jboolean normalize_for_write(jboolean x) {
 199     return x & 1;
 200   }
 201 
 202   template <typename U>
 203   U normalize_for_read(U x) {
 204     return x;
 205   }
 206 
 207   jboolean normalize_for_read(jboolean x) {
 208     return x != 0;
 209   }
 210 
 211 public:
 212   MemoryAccess(JavaThread* thread, jobject obj, jlong offset)
 213     : _thread(thread), _obj(JNIHandles::resolve(obj)), _offset((ptrdiff_t)offset) {
 214     assert_field_offset_sane(_obj, offset);
 215   }
 216 
 217   T get() {
 218     if (_obj == NULL) {
 219       GuardUnsafeAccess guard(_thread);
 220       T ret = RawAccess<>::load(addr());
 221       return normalize_for_read(ret);
 222     } else {
 223       T ret = HeapAccess<>::load_at(_obj, _offset);
 224       return normalize_for_read(ret);
 225     }
 226   }
 227 
 228   void put(T x) {
 229     if (_obj == NULL) {
 230       GuardUnsafeAccess guard(_thread);
 231       RawAccess<>::store(addr(), normalize_for_write(x));
 232     } else {
 233       HeapAccess<>::store_at(_obj, _offset, normalize_for_write(x));
 234     }
 235   }
 236 
 237 
 238   T get_volatile() {
 239     if (_obj == NULL) {
 240       GuardUnsafeAccess guard(_thread);
 241       volatile T ret = RawAccess<MO_SEQ_CST>::load(addr());
 242       return normalize_for_read(ret);
 243     } else {
 244       T ret = HeapAccess<MO_SEQ_CST>::load_at(_obj, _offset);
 245       return normalize_for_read(ret);
 246     }
 247   }
 248 
 249   void put_volatile(T x) {
 250     if (_obj == NULL) {
 251       GuardUnsafeAccess guard(_thread);
 252       RawAccess<MO_SEQ_CST>::store(addr(), normalize_for_write(x));
 253     } else {
 254       HeapAccess<MO_SEQ_CST>::store_at(_obj, _offset, normalize_for_write(x));
 255     }
 256   }
 257 };
 258 
 259 // These functions allow a null base pointer with an arbitrary address.
 260 // But if the base pointer is non-null, the offset should make some sense.
 261 // That is, it should be in the range [0, MAX_OBJECT_SIZE].
 262 UNSAFE_ENTRY(jobject, Unsafe_GetReference(JNIEnv *env, jobject unsafe, jobject obj, jlong offset)) {
 263   oop p = JNIHandles::resolve(obj);
 264   assert_field_offset_sane(p, offset);
 265   oop v = HeapAccess<ON_UNKNOWN_OOP_REF>::oop_load_at(p, offset);
 266   return JNIHandles::make_local(env, v);
 267 } UNSAFE_END
 268 
 269 UNSAFE_ENTRY(void, Unsafe_PutReference(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jobject x_h)) {
 270   oop x = JNIHandles::resolve(x_h);
 271   oop p = JNIHandles::resolve(obj);
 272   assert_field_offset_sane(p, offset);
 273   HeapAccess<ON_UNKNOWN_OOP_REF>::oop_store_at(p, offset, x);
 274 } UNSAFE_END
 275 
 276 UNSAFE_ENTRY(jobject, Unsafe_GetReferenceVolatile(JNIEnv *env, jobject unsafe, jobject obj, jlong offset)) {
 277   oop p = JNIHandles::resolve(obj);
 278   assert_field_offset_sane(p, offset);
 279   oop v = HeapAccess<MO_SEQ_CST | ON_UNKNOWN_OOP_REF>::oop_load_at(p, offset);
 280   return JNIHandles::make_local(env, v);
 281 } UNSAFE_END
 282 
 283 UNSAFE_ENTRY(void, Unsafe_PutReferenceVolatile(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jobject x_h)) {
 284   oop x = JNIHandles::resolve(x_h);
 285   oop p = JNIHandles::resolve(obj);
 286   assert_field_offset_sane(p, offset);
 287   HeapAccess<MO_SEQ_CST | ON_UNKNOWN_OOP_REF>::oop_store_at(p, offset, x);
 288 } UNSAFE_END
 289 
 290 UNSAFE_ENTRY(jobject, Unsafe_GetUncompressedObject(JNIEnv *env, jobject unsafe, jlong addr)) {
 291   oop v = *(oop*) (address) addr;
 292   return JNIHandles::make_local(env, v);
 293 } UNSAFE_END
 294 
 295 #define DEFINE_GETSETOOP(java_type, Type) \
 296  \
 297 UNSAFE_ENTRY(java_type, Unsafe_Get##Type(JNIEnv *env, jobject unsafe, jobject obj, jlong offset)) { \
 298   return MemoryAccess<java_type>(thread, obj, offset).get(); \
 299 } UNSAFE_END \
 300  \
 301 UNSAFE_ENTRY(void, Unsafe_Put##Type(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, java_type x)) { \
 302   MemoryAccess<java_type>(thread, obj, offset).put(x); \
 303 } UNSAFE_END \
 304  \
 305 // END DEFINE_GETSETOOP.
 306 
 307 DEFINE_GETSETOOP(jboolean, Boolean)
 308 DEFINE_GETSETOOP(jbyte, Byte)
 309 DEFINE_GETSETOOP(jshort, Short);
 310 DEFINE_GETSETOOP(jchar, Char);
 311 DEFINE_GETSETOOP(jint, Int);
 312 DEFINE_GETSETOOP(jlong, Long);
 313 DEFINE_GETSETOOP(jfloat, Float);
 314 DEFINE_GETSETOOP(jdouble, Double);
 315 
 316 #undef DEFINE_GETSETOOP
 317 
 318 #define DEFINE_GETSETOOP_VOLATILE(java_type, Type) \
 319  \
 320 UNSAFE_ENTRY(java_type, Unsafe_Get##Type##Volatile(JNIEnv *env, jobject unsafe, jobject obj, jlong offset)) { \
 321   return MemoryAccess<java_type>(thread, obj, offset).get_volatile(); \
 322 } UNSAFE_END \
 323  \
 324 UNSAFE_ENTRY(void, Unsafe_Put##Type##Volatile(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, java_type x)) { \
 325   MemoryAccess<java_type>(thread, obj, offset).put_volatile(x); \
 326 } UNSAFE_END \
 327  \
 328 // END DEFINE_GETSETOOP_VOLATILE.
 329 
 330 DEFINE_GETSETOOP_VOLATILE(jboolean, Boolean)
 331 DEFINE_GETSETOOP_VOLATILE(jbyte, Byte)
 332 DEFINE_GETSETOOP_VOLATILE(jshort, Short);
 333 DEFINE_GETSETOOP_VOLATILE(jchar, Char);
 334 DEFINE_GETSETOOP_VOLATILE(jint, Int);
 335 DEFINE_GETSETOOP_VOLATILE(jlong, Long);
 336 DEFINE_GETSETOOP_VOLATILE(jfloat, Float);
 337 DEFINE_GETSETOOP_VOLATILE(jdouble, Double);
 338 
 339 #undef DEFINE_GETSETOOP_VOLATILE
 340 
 341 UNSAFE_LEAF(void, Unsafe_LoadFence(JNIEnv *env, jobject unsafe)) {
 342   OrderAccess::acquire();
 343 } UNSAFE_END
 344 
 345 UNSAFE_LEAF(void, Unsafe_StoreFence(JNIEnv *env, jobject unsafe)) {
 346   OrderAccess::release();
 347 } UNSAFE_END
 348 
 349 UNSAFE_LEAF(void, Unsafe_FullFence(JNIEnv *env, jobject unsafe)) {
 350   OrderAccess::fence();
 351 } UNSAFE_END
 352 
 353 ////// Allocation requests
 354 
 355 UNSAFE_ENTRY(jobject, Unsafe_AllocateInstance(JNIEnv *env, jobject unsafe, jclass cls)) {
 356   ThreadToNativeFromVM ttnfv(thread);
 357   return env->AllocObject(cls);
 358 } UNSAFE_END
 359 
 360 UNSAFE_ENTRY(jlong, Unsafe_AllocateMemory0(JNIEnv *env, jobject unsafe, jlong size)) {
 361   size_t sz = (size_t)size;
 362 
 363   sz = align_up(sz, HeapWordSize);
 364   void* x = os::malloc(sz, mtOther);
 365 
 366   return addr_to_java(x);
 367 } UNSAFE_END
 368 
 369 UNSAFE_ENTRY(jlong, Unsafe_ReallocateMemory0(JNIEnv *env, jobject unsafe, jlong addr, jlong size)) {
 370   void* p = addr_from_java(addr);
 371   size_t sz = (size_t)size;
 372   sz = align_up(sz, HeapWordSize);
 373 
 374   void* x = os::realloc(p, sz, mtOther);
 375 
 376   return addr_to_java(x);
 377 } UNSAFE_END
 378 
 379 UNSAFE_ENTRY(void, Unsafe_FreeMemory0(JNIEnv *env, jobject unsafe, jlong addr)) {
 380   void* p = addr_from_java(addr);
 381 
 382   os::free(p);
 383 } UNSAFE_END
 384 
 385 UNSAFE_ENTRY(void, Unsafe_SetMemory0(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jlong size, jbyte value)) {
 386   size_t sz = (size_t)size;
 387 
 388   oop base = JNIHandles::resolve(obj);
 389   void* p = index_oop_from_field_offset_long(base, offset);
 390 
 391   Copy::fill_to_memory_atomic(p, sz, value);
 392 } UNSAFE_END
 393 
 394 UNSAFE_ENTRY(void, Unsafe_CopyMemory0(JNIEnv *env, jobject unsafe, jobject srcObj, jlong srcOffset, jobject dstObj, jlong dstOffset, jlong size)) {
 395   size_t sz = (size_t)size;
 396 
 397   oop srcp = JNIHandles::resolve(srcObj);
 398   oop dstp = JNIHandles::resolve(dstObj);
 399 
 400   void* src = index_oop_from_field_offset_long(srcp, srcOffset);
 401   void* dst = index_oop_from_field_offset_long(dstp, dstOffset);
 402   {
 403     GuardUnsafeAccess guard(thread);
 404     if (StubRoutines::unsafe_arraycopy() != NULL) {
 405       StubRoutines::UnsafeArrayCopy_stub()(src, dst, sz);
 406     } else {
 407       Copy::conjoint_memory_atomic(src, dst, sz);
 408     }
 409   }
 410 } UNSAFE_END
 411 
 412 // This function is a leaf since if the source and destination are both in native memory
 413 // the copy may potentially be very large, and we don't want to disable GC if we can avoid it.
 414 // If either source or destination (or both) are on the heap, the function will enter VM using
 415 // JVM_ENTRY_FROM_LEAF
 416 UNSAFE_LEAF(void, Unsafe_CopySwapMemory0(JNIEnv *env, jobject unsafe, jobject srcObj, jlong srcOffset, jobject dstObj, jlong dstOffset, jlong size, jlong elemSize)) {
 417   size_t sz = (size_t)size;
 418   size_t esz = (size_t)elemSize;
 419 
 420   if (srcObj == NULL && dstObj == NULL) {
 421     // Both src & dst are in native memory
 422     address src = (address)srcOffset;
 423     address dst = (address)dstOffset;
 424 
 425     {
 426       JavaThread* thread = JavaThread::thread_from_jni_environment(env);
 427       GuardUnsafeAccess guard(thread);
 428       Copy::conjoint_swap(src, dst, sz, esz);
 429     }
 430   } else {
 431     // At least one of src/dst are on heap, transition to VM to access raw pointers
 432 
 433     JVM_ENTRY_FROM_LEAF(env, void, Unsafe_CopySwapMemory0) {
 434       oop srcp = JNIHandles::resolve(srcObj);
 435       oop dstp = JNIHandles::resolve(dstObj);
 436 
 437       address src = (address)index_oop_from_field_offset_long(srcp, srcOffset);
 438       address dst = (address)index_oop_from_field_offset_long(dstp, dstOffset);
 439 
 440       {
 441         GuardUnsafeAccess guard(thread);
 442         Copy::conjoint_swap(src, dst, sz, esz);
 443       }
 444     } JVM_END
 445   }
 446 } UNSAFE_END
 447 
 448 UNSAFE_LEAF (void, Unsafe_WriteBack0(JNIEnv *env, jobject unsafe, jlong line)) {
 449   assert(VM_Version::supports_data_cache_line_flush(), "should not get here");
 450 #ifdef ASSERT
 451   if (TraceMemoryWriteback) {
 452     tty->print_cr("Unsafe: writeback 0x%p", addr_from_java(line));
 453   }
 454 #endif
 455 
 456   assert(StubRoutines::data_cache_writeback() != NULL, "sanity");
 457   (StubRoutines::DataCacheWriteback_stub())(addr_from_java(line));
 458 } UNSAFE_END
 459 
 460 static void doWriteBackSync0(bool is_pre)
 461 {
 462   assert(StubRoutines::data_cache_writeback_sync() != NULL, "sanity");
 463   (StubRoutines::DataCacheWritebackSync_stub())(is_pre);
 464 }
 465 
 466 UNSAFE_LEAF (void, Unsafe_WriteBackPreSync0(JNIEnv *env, jobject unsafe)) {
 467   assert(VM_Version::supports_data_cache_line_flush(), "should not get here");
 468 #ifdef ASSERT
 469   if (TraceMemoryWriteback) {
 470       tty->print_cr("Unsafe: writeback pre-sync");
 471   }
 472 #endif
 473 
 474   doWriteBackSync0(true);
 475 } UNSAFE_END
 476 
 477 UNSAFE_LEAF (void, Unsafe_WriteBackPostSync0(JNIEnv *env, jobject unsafe)) {
 478   assert(VM_Version::supports_data_cache_line_flush(), "should not get here");
 479 #ifdef ASSERT
 480   if (TraceMemoryWriteback) {
 481     tty->print_cr("Unsafe: writeback pre-sync");
 482   }
 483 #endif
 484 
 485   doWriteBackSync0(false);
 486 } UNSAFE_END
 487 
 488 ////// Random queries
 489 
 490 static jlong find_field_offset(jclass clazz, jstring name, TRAPS) {
 491   assert(clazz != NULL, "clazz must not be NULL");
 492   assert(name != NULL, "name must not be NULL");
 493 
 494   ResourceMark rm(THREAD);
 495   char *utf_name = java_lang_String::as_utf8_string(JNIHandles::resolve_non_null(name));
 496 
 497   InstanceKlass* k = InstanceKlass::cast(java_lang_Class::as_Klass(JNIHandles::resolve_non_null(clazz)));
 498 
 499   jint offset = -1;
 500   for (JavaFieldStream fs(k); !fs.done(); fs.next()) {
 501     Symbol *name = fs.name();
 502     if (name->equals(utf_name)) {
 503       offset = fs.offset();
 504       break;
 505     }
 506   }
 507   if (offset < 0) {
 508     THROW_0(vmSymbols::java_lang_InternalError());
 509   }
 510   return field_offset_from_byte_offset(offset);
 511 }
 512 
 513 static jlong find_field_offset(jobject field, int must_be_static, TRAPS) {
 514   assert(field != NULL, "field must not be NULL");
 515 
 516   oop reflected   = JNIHandles::resolve_non_null(field);
 517   oop mirror      = java_lang_reflect_Field::clazz(reflected);
 518   Klass* k        = java_lang_Class::as_Klass(mirror);
 519   int slot        = java_lang_reflect_Field::slot(reflected);
 520   int modifiers   = java_lang_reflect_Field::modifiers(reflected);
 521 
 522   if (must_be_static >= 0) {
 523     int really_is_static = ((modifiers & JVM_ACC_STATIC) != 0);
 524     if (must_be_static != really_is_static) {
 525       THROW_0(vmSymbols::java_lang_IllegalArgumentException());
 526     }
 527   }
 528 
 529   int offset = InstanceKlass::cast(k)->field_offset(slot);
 530   return field_offset_from_byte_offset(offset);
 531 }
 532 
 533 UNSAFE_ENTRY(jlong, Unsafe_ObjectFieldOffset0(JNIEnv *env, jobject unsafe, jobject field)) {
 534   return find_field_offset(field, 0, THREAD);
 535 } UNSAFE_END
 536 
 537 UNSAFE_ENTRY(jlong, Unsafe_ObjectFieldOffset1(JNIEnv *env, jobject unsafe, jclass c, jstring name)) {
 538   return find_field_offset(c, name, THREAD);
 539 } UNSAFE_END
 540 
 541 UNSAFE_ENTRY(jlong, Unsafe_StaticFieldOffset0(JNIEnv *env, jobject unsafe, jobject field)) {
 542   return find_field_offset(field, 1, THREAD);
 543 } UNSAFE_END
 544 
 545 UNSAFE_ENTRY(jobject, Unsafe_StaticFieldBase0(JNIEnv *env, jobject unsafe, jobject field)) {
 546   assert(field != NULL, "field must not be NULL");
 547 
 548   // Note:  In this VM implementation, a field address is always a short
 549   // offset from the base of a a klass metaobject.  Thus, the full dynamic
 550   // range of the return type is never used.  However, some implementations
 551   // might put the static field inside an array shared by many classes,
 552   // or even at a fixed address, in which case the address could be quite
 553   // large.  In that last case, this function would return NULL, since
 554   // the address would operate alone, without any base pointer.
 555 
 556   oop reflected   = JNIHandles::resolve_non_null(field);
 557   oop mirror      = java_lang_reflect_Field::clazz(reflected);
 558   int modifiers   = java_lang_reflect_Field::modifiers(reflected);
 559 
 560   if ((modifiers & JVM_ACC_STATIC) == 0) {
 561     THROW_0(vmSymbols::java_lang_IllegalArgumentException());
 562   }
 563 
 564   return JNIHandles::make_local(env, mirror);
 565 } UNSAFE_END
 566 
 567 UNSAFE_ENTRY(void, Unsafe_EnsureClassInitialized0(JNIEnv *env, jobject unsafe, jobject clazz)) {
 568   assert(clazz != NULL, "clazz must not be NULL");
 569 
 570   oop mirror = JNIHandles::resolve_non_null(clazz);
 571 
 572   Klass* klass = java_lang_Class::as_Klass(mirror);
 573   if (klass != NULL && klass->should_be_initialized()) {
 574     InstanceKlass* k = InstanceKlass::cast(klass);
 575     k->initialize(CHECK);
 576   }
 577 }
 578 UNSAFE_END
 579 
 580 UNSAFE_ENTRY(jboolean, Unsafe_ShouldBeInitialized0(JNIEnv *env, jobject unsafe, jobject clazz)) {
 581   assert(clazz != NULL, "clazz must not be NULL");
 582 
 583   oop mirror = JNIHandles::resolve_non_null(clazz);
 584   Klass* klass = java_lang_Class::as_Klass(mirror);
 585 
 586   if (klass != NULL && klass->should_be_initialized()) {
 587     return true;
 588   }
 589 
 590   return false;
 591 }
 592 UNSAFE_END
 593 
 594 static void getBaseAndScale(int& base, int& scale, jclass clazz, TRAPS) {
 595   assert(clazz != NULL, "clazz must not be NULL");
 596 
 597   oop mirror = JNIHandles::resolve_non_null(clazz);
 598   Klass* k = java_lang_Class::as_Klass(mirror);
 599 
 600   if (k == NULL || !k->is_array_klass()) {
 601     THROW(vmSymbols::java_lang_InvalidClassException());
 602   } else if (k->is_objArray_klass()) {
 603     base  = arrayOopDesc::base_offset_in_bytes(T_OBJECT);
 604     scale = heapOopSize;
 605   } else if (k->is_typeArray_klass()) {
 606     TypeArrayKlass* tak = TypeArrayKlass::cast(k);
 607     base  = tak->array_header_in_bytes();
 608     assert(base == arrayOopDesc::base_offset_in_bytes(tak->element_type()), "array_header_size semantics ok");
 609     scale = (1 << tak->log2_element_size());
 610   } else {
 611     ShouldNotReachHere();
 612   }
 613 }
 614 
 615 UNSAFE_ENTRY(jint, Unsafe_ArrayBaseOffset0(JNIEnv *env, jobject unsafe, jclass clazz)) {
 616   int base = 0, scale = 0;
 617   getBaseAndScale(base, scale, clazz, CHECK_0);
 618 
 619   return field_offset_from_byte_offset(base);
 620 } UNSAFE_END
 621 
 622 
 623 UNSAFE_ENTRY(jint, Unsafe_ArrayIndexScale0(JNIEnv *env, jobject unsafe, jclass clazz)) {
 624   int base = 0, scale = 0;
 625   getBaseAndScale(base, scale, clazz, CHECK_0);
 626 
 627   // This VM packs both fields and array elements down to the byte.
 628   // But watch out:  If this changes, so that array references for
 629   // a given primitive type (say, T_BOOLEAN) use different memory units
 630   // than fields, this method MUST return zero for such arrays.
 631   // For example, the VM used to store sub-word sized fields in full
 632   // words in the object layout, so that accessors like getByte(Object,int)
 633   // did not really do what one might expect for arrays.  Therefore,
 634   // this function used to report a zero scale factor, so that the user
 635   // would know not to attempt to access sub-word array elements.
 636   // // Code for unpacked fields:
 637   // if (scale < wordSize)  return 0;
 638 
 639   // The following allows for a pretty general fieldOffset cookie scheme,
 640   // but requires it to be linear in byte offset.
 641   return field_offset_from_byte_offset(scale) - field_offset_from_byte_offset(0);
 642 } UNSAFE_END
 643 
 644 
 645 static inline void throw_new(JNIEnv *env, const char *ename) {
 646   jclass cls = env->FindClass(ename);
 647   if (env->ExceptionCheck()) {
 648     env->ExceptionClear();
 649     tty->print_cr("Unsafe: cannot throw %s because FindClass has failed", ename);
 650     return;
 651   }
 652 
 653   env->ThrowNew(cls, NULL);
 654 }
 655 
 656 static jclass Unsafe_DefineClass_impl(JNIEnv *env, jstring name, jbyteArray data, int offset, int length, jobject loader, jobject pd) {
 657   // Code lifted from JDK 1.3 ClassLoader.c
 658 
 659   jbyte *body;
 660   char *utfName = NULL;
 661   jclass result = 0;
 662   char buf[128];
 663 
 664   assert(data != NULL, "Class bytes must not be NULL");
 665   assert(length >= 0, "length must not be negative: %d", length);
 666 
 667   if (UsePerfData) {
 668     ClassLoader::unsafe_defineClassCallCounter()->inc();
 669   }
 670 
 671   body = NEW_C_HEAP_ARRAY_RETURN_NULL(jbyte, length, mtInternal);
 672   if (body == NULL) {
 673     throw_new(env, "java/lang/OutOfMemoryError");
 674     return 0;
 675   }
 676 
 677   env->GetByteArrayRegion(data, offset, length, body);
 678   if (env->ExceptionOccurred()) {
 679     goto free_body;
 680   }
 681 
 682   if (name != NULL) {
 683     uint len = env->GetStringUTFLength(name);
 684     int unicode_len = env->GetStringLength(name);
 685 
 686     if (len >= sizeof(buf)) {
 687       utfName = NEW_C_HEAP_ARRAY_RETURN_NULL(char, len + 1, mtInternal);
 688       if (utfName == NULL) {
 689         throw_new(env, "java/lang/OutOfMemoryError");
 690         goto free_body;
 691       }
 692     } else {
 693       utfName = buf;
 694     }
 695 
 696     env->GetStringUTFRegion(name, 0, unicode_len, utfName);
 697 
 698     for (uint i = 0; i < len; i++) {
 699       if (utfName[i] == '.')   utfName[i] = '/';
 700     }
 701   }
 702 
 703   result = JVM_DefineClass(env, utfName, loader, body, length, pd);
 704 
 705   if (utfName && utfName != buf) {
 706     FREE_C_HEAP_ARRAY(char, utfName);
 707   }
 708 
 709  free_body:
 710   FREE_C_HEAP_ARRAY(jbyte, body);
 711   return result;
 712 }
 713 
 714 
 715 UNSAFE_ENTRY(jclass, Unsafe_DefineClass0(JNIEnv *env, jobject unsafe, jstring name, jbyteArray data, int offset, int length, jobject loader, jobject pd)) {
 716   ThreadToNativeFromVM ttnfv(thread);
 717 
 718   return Unsafe_DefineClass_impl(env, name, data, offset, length, loader, pd);
 719 } UNSAFE_END
 720 
 721 
 722 // define a class but do not make it known to the class loader or system dictionary
 723 // - host_class:  supplies context for linkage, access control, protection domain, and class loader
 724 //                if host_class is itself anonymous then it is replaced with its host class.
 725 // - data:  bytes of a class file, a raw memory address (length gives the number of bytes)
 726 // - cp_patches:  where non-null entries exist, they replace corresponding CP entries in data
 727 
 728 // When you load an anonymous class U, it works as if you changed its name just before loading,
 729 // to a name that you will never use again.  Since the name is lost, no other class can directly
 730 // link to any member of U.  Just after U is loaded, the only way to use it is reflectively,
 731 // through java.lang.Class methods like Class.newInstance.
 732 
 733 // The package of an anonymous class must either match its host's class's package or be in the
 734 // unnamed package.  If it is in the unnamed package then it will be put in its host class's
 735 // package.
 736 //
 737 
 738 // Access checks for linkage sites within U continue to follow the same rules as for named classes.
 739 // An anonymous class also has special privileges to access any member of its host class.
 740 // This is the main reason why this loading operation is unsafe.  The purpose of this is to
 741 // allow language implementations to simulate "open classes"; a host class in effect gets
 742 // new code when an anonymous class is loaded alongside it.  A less convenient but more
 743 // standard way to do this is with reflection, which can also be set to ignore access
 744 // restrictions.
 745 
 746 // Access into an anonymous class is possible only through reflection.  Therefore, there
 747 // are no special access rules for calling into an anonymous class.  The relaxed access
 748 // rule for the host class is applied in the opposite direction:  A host class reflectively
 749 // access one of its anonymous classes.
 750 
 751 // If you load the same bytecodes twice, you get two different classes.  You can reload
 752 // the same bytecodes with or without varying CP patches.
 753 
 754 // By using the CP patching array, you can have a new anonymous class U2 refer to an older one U1.
 755 // The bytecodes for U2 should refer to U1 by a symbolic name (doesn't matter what the name is).
 756 // The CONSTANT_Class entry for that name can be patched to refer directly to U1.
 757 
 758 // This allows, for example, U2 to use U1 as a superclass or super-interface, or as
 759 // an outer class (so that U2 is an anonymous inner class of anonymous U1).
 760 // It is not possible for a named class, or an older anonymous class, to refer by
 761 // name (via its CP) to a newer anonymous class.
 762 
 763 // CP patching may also be used to modify (i.e., hack) the names of methods, classes,
 764 // or type descriptors used in the loaded anonymous class.
 765 
 766 // Finally, CP patching may be used to introduce "live" objects into the constant pool,
 767 // instead of "dead" strings.  A compiled statement like println((Object)"hello") can
 768 // be changed to println(greeting), where greeting is an arbitrary object created before
 769 // the anonymous class is loaded.  This is useful in dynamic languages, in which
 770 // various kinds of metaobjects must be introduced as constants into bytecode.
 771 // Note the cast (Object), which tells the verifier to expect an arbitrary object,
 772 // not just a literal string.  For such ldc instructions, the verifier uses the
 773 // type Object instead of String, if the loaded constant is not in fact a String.
 774 
 775 static InstanceKlass*
 776 Unsafe_DefineAnonymousClass_impl(JNIEnv *env,
 777                                  jclass host_class, jbyteArray data, jobjectArray cp_patches_jh,
 778                                  u1** temp_alloc,
 779                                  TRAPS) {
 780   assert(host_class != NULL, "host_class must not be NULL");
 781   assert(data != NULL, "data must not be NULL");
 782 
 783   if (UsePerfData) {
 784     ClassLoader::unsafe_defineClassCallCounter()->inc();
 785   }
 786 
 787   jint length = typeArrayOop(JNIHandles::resolve_non_null(data))->length();
 788   assert(length >= 0, "class_bytes_length must not be negative: %d", length);
 789 
 790   int class_bytes_length = (int) length;
 791 
 792   u1* class_bytes = NEW_C_HEAP_ARRAY_RETURN_NULL(u1, length, mtInternal);
 793   if (class_bytes == NULL) {
 794     THROW_0(vmSymbols::java_lang_OutOfMemoryError());
 795   }
 796 
 797   // caller responsible to free it:
 798   *temp_alloc = class_bytes;
 799 
 800   ArrayAccess<>::arraycopy_to_native(arrayOop(JNIHandles::resolve_non_null(data)), typeArrayOopDesc::element_offset<jbyte>(0),
 801                                      reinterpret_cast<jbyte*>(class_bytes), length);
 802 
 803   objArrayHandle cp_patches_h;
 804   if (cp_patches_jh != NULL) {
 805     oop p = JNIHandles::resolve_non_null(cp_patches_jh);
 806     assert(p->is_objArray(), "cp_patches must be an object[]");
 807     cp_patches_h = objArrayHandle(THREAD, (objArrayOop)p);
 808   }
 809 
 810   const Klass* host_klass = java_lang_Class::as_Klass(JNIHandles::resolve_non_null(host_class));
 811 
 812   // Make sure it's the real host class, not another anonymous class.
 813   while (host_klass != NULL && host_klass->is_instance_klass() &&
 814          InstanceKlass::cast(host_klass)->is_unsafe_anonymous()) {
 815     host_klass = InstanceKlass::cast(host_klass)->unsafe_anonymous_host();
 816   }
 817 
 818   // Primitive types have NULL Klass* fields in their java.lang.Class instances.
 819   if (host_klass == NULL) {
 820     THROW_MSG_0(vmSymbols::java_lang_IllegalArgumentException(), "Host class is null");
 821   }
 822 
 823   assert(host_klass->is_instance_klass(), "Host class must be an instance class");
 824 
 825   const char* host_source = host_klass->external_name();
 826   Handle      host_loader(THREAD, host_klass->class_loader());
 827   Handle      host_domain(THREAD, host_klass->protection_domain());
 828 
 829   GrowableArray<Handle>* cp_patches = NULL;
 830 
 831   if (cp_patches_h.not_null()) {
 832     int alen = cp_patches_h->length();
 833 
 834     for (int i = alen-1; i >= 0; i--) {
 835       oop p = cp_patches_h->obj_at(i);
 836       if (p != NULL) {
 837         Handle patch(THREAD, p);
 838 
 839         if (cp_patches == NULL) {
 840           cp_patches = new GrowableArray<Handle>(i+1, i+1, Handle());
 841         }
 842 
 843         cp_patches->at_put(i, patch);
 844       }
 845     }
 846   }
 847 
 848   ClassFileStream st(class_bytes, class_bytes_length, host_source, ClassFileStream::verify);
 849 
 850   Symbol* no_class_name = NULL;
 851   Klass* anonk = SystemDictionary::parse_stream(no_class_name,
 852                                                 host_loader,
 853                                                 host_domain,
 854                                                 &st,
 855                                                 InstanceKlass::cast(host_klass),
 856                                                 cp_patches,
 857                                                 CHECK_NULL);
 858   if (anonk == NULL) {
 859     return NULL;
 860   }
 861 
 862   return InstanceKlass::cast(anonk);
 863 }
 864 
 865 UNSAFE_ENTRY(jclass, Unsafe_DefineAnonymousClass0(JNIEnv *env, jobject unsafe, jclass host_class, jbyteArray data, jobjectArray cp_patches_jh)) {
 866   ResourceMark rm(THREAD);
 867 
 868   jobject res_jh = NULL;
 869   u1* temp_alloc = NULL;
 870 
 871   InstanceKlass* anon_klass = Unsafe_DefineAnonymousClass_impl(env, host_class, data, cp_patches_jh, &temp_alloc, THREAD);
 872   if (anon_klass != NULL) {
 873     res_jh = JNIHandles::make_local(env, anon_klass->java_mirror());
 874   }
 875 
 876   // try/finally clause:
 877   FREE_C_HEAP_ARRAY(u1, temp_alloc);
 878 
 879   // The anonymous class loader data has been artificially been kept alive to
 880   // this point.   The mirror and any instances of this class have to keep
 881   // it alive afterwards.
 882   if (anon_klass != NULL) {
 883     anon_klass->class_loader_data()->dec_keep_alive();
 884   }
 885 
 886   // let caller initialize it as needed...
 887 
 888   return (jclass) res_jh;
 889 } UNSAFE_END
 890 
 891 
 892 
 893 UNSAFE_ENTRY(void, Unsafe_ThrowException(JNIEnv *env, jobject unsafe, jthrowable thr)) {
 894   ThreadToNativeFromVM ttnfv(thread);
 895   env->Throw(thr);
 896 } UNSAFE_END
 897 
 898 // JSR166 ------------------------------------------------------------------
 899 
 900 UNSAFE_ENTRY(jobject, Unsafe_CompareAndExchangeReference(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jobject e_h, jobject x_h)) {
 901   oop x = JNIHandles::resolve(x_h);
 902   oop e = JNIHandles::resolve(e_h);
 903   oop p = JNIHandles::resolve(obj);
 904   assert_field_offset_sane(p, offset);
 905   oop res = HeapAccess<ON_UNKNOWN_OOP_REF>::oop_atomic_cmpxchg_at(p, (ptrdiff_t)offset, e, x);
 906   return JNIHandles::make_local(env, res);
 907 } UNSAFE_END
 908 
 909 UNSAFE_ENTRY(jint, Unsafe_CompareAndExchangeInt(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jint e, jint x)) {
 910   oop p = JNIHandles::resolve(obj);
 911   if (p == NULL) {
 912     volatile jint* addr = (volatile jint*)index_oop_from_field_offset_long(p, offset);
 913     return RawAccess<>::atomic_cmpxchg(addr, e, x);
 914   } else {
 915     assert_field_offset_sane(p, offset);
 916     return HeapAccess<>::atomic_cmpxchg_at(p, (ptrdiff_t)offset, e, x);
 917   }
 918 } UNSAFE_END
 919 
 920 UNSAFE_ENTRY(jlong, Unsafe_CompareAndExchangeLong(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jlong e, jlong x)) {
 921   oop p = JNIHandles::resolve(obj);
 922   if (p == NULL) {
 923     volatile jlong* addr = (volatile jlong*)index_oop_from_field_offset_long(p, offset);
 924     return RawAccess<>::atomic_cmpxchg(addr, e, x);
 925   } else {
 926     assert_field_offset_sane(p, offset);
 927     return HeapAccess<>::atomic_cmpxchg_at(p, (ptrdiff_t)offset, e, x);
 928   }
 929 } UNSAFE_END
 930 
 931 UNSAFE_ENTRY(jboolean, Unsafe_CompareAndSetReference(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jobject e_h, jobject x_h)) {
 932   oop x = JNIHandles::resolve(x_h);
 933   oop e = JNIHandles::resolve(e_h);
 934   oop p = JNIHandles::resolve(obj);
 935   assert_field_offset_sane(p, offset);
 936   oop ret = HeapAccess<ON_UNKNOWN_OOP_REF>::oop_atomic_cmpxchg_at(p, (ptrdiff_t)offset, e, x);
 937   return ret == e;
 938 } UNSAFE_END
 939 
 940 UNSAFE_ENTRY(jboolean, Unsafe_CompareAndSetInt(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jint e, jint x)) {
 941   oop p = JNIHandles::resolve(obj);
 942   if (p == NULL) {
 943     volatile jint* addr = (volatile jint*)index_oop_from_field_offset_long(p, offset);
 944     return RawAccess<>::atomic_cmpxchg(addr, e, x) == e;
 945   } else {
 946     assert_field_offset_sane(p, offset);
 947     return HeapAccess<>::atomic_cmpxchg_at(p, (ptrdiff_t)offset, e, x) == e;
 948   }
 949 } UNSAFE_END
 950 
 951 UNSAFE_ENTRY(jboolean, Unsafe_CompareAndSetLong(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jlong e, jlong x)) {
 952   oop p = JNIHandles::resolve(obj);
 953   if (p == NULL) {
 954     volatile jlong* addr = (volatile jlong*)index_oop_from_field_offset_long(p, offset);
 955     return RawAccess<>::atomic_cmpxchg(addr, e, x) == e;
 956   } else {
 957     assert_field_offset_sane(p, offset);
 958     return HeapAccess<>::atomic_cmpxchg_at(p, (ptrdiff_t)offset, e, x) == e;
 959   }
 960 } UNSAFE_END
 961 
 962 static void post_thread_park_event(EventThreadPark* event, const oop obj, jlong timeout_nanos, jlong until_epoch_millis) {
 963   assert(event != NULL, "invariant");
 964   assert(event->should_commit(), "invariant");
 965   event->set_parkedClass((obj != NULL) ? obj->klass() : NULL);
 966   event->set_timeout(timeout_nanos);
 967   event->set_until(until_epoch_millis);
 968   event->set_address((obj != NULL) ? (u8)cast_from_oop<uintptr_t>(obj) : 0);
 969   event->commit();
 970 }
 971 
 972 UNSAFE_ENTRY(void, Unsafe_Park(JNIEnv *env, jobject unsafe, jboolean isAbsolute, jlong time)) {
 973   HOTSPOT_THREAD_PARK_BEGIN((uintptr_t) thread->parker(), (int) isAbsolute, time);
 974   EventThreadPark event;
 975 
 976   JavaThreadParkedState jtps(thread, time != 0);
 977   thread->parker()->park(isAbsolute != 0, time);
 978   if (event.should_commit()) {
 979     const oop obj = thread->current_park_blocker();
 980     if (time == 0) {
 981       post_thread_park_event(&event, obj, min_jlong, min_jlong);
 982     } else {
 983       if (isAbsolute != 0) {
 984         post_thread_park_event(&event, obj, min_jlong, time);
 985       } else {
 986         post_thread_park_event(&event, obj, time, min_jlong);
 987       }
 988     }
 989   }
 990   HOTSPOT_THREAD_PARK_END((uintptr_t) thread->parker());
 991 } UNSAFE_END
 992 
 993 UNSAFE_ENTRY(void, Unsafe_Unpark(JNIEnv *env, jobject unsafe, jobject jthread)) {
 994   Parker* p = NULL;
 995 
 996   if (jthread != NULL) {
 997     ThreadsListHandle tlh;
 998     JavaThread* thr = NULL;
 999     oop java_thread = NULL;
1000     (void) tlh.cv_internal_thread_to_JavaThread(jthread, &thr, &java_thread);
1001     if (java_thread != NULL) {
1002       // This is a valid oop.
1003       if (thr != NULL) {
1004         // The JavaThread is alive.
1005         p = thr->parker();
1006       }
1007     }
1008   } // ThreadsListHandle is destroyed here.
1009 
1010   // 'p' points to type-stable-memory if non-NULL. If the target
1011   // thread terminates before we get here the new user of this
1012   // Parker will get a 'spurious' unpark - which is perfectly valid.
1013   if (p != NULL) {
1014     HOTSPOT_THREAD_UNPARK((uintptr_t) p);
1015     p->unpark();
1016   }
1017 } UNSAFE_END
1018 
1019 UNSAFE_ENTRY(jint, Unsafe_GetLoadAverage0(JNIEnv *env, jobject unsafe, jdoubleArray loadavg, jint nelem)) {
1020   const int max_nelem = 3;
1021   double la[max_nelem];
1022   jint ret;
1023 
1024   typeArrayOop a = typeArrayOop(JNIHandles::resolve_non_null(loadavg));
1025   assert(a->is_typeArray(), "must be type array");
1026 
1027   ret = os::loadavg(la, nelem);
1028   if (ret == -1) {
1029     return -1;
1030   }
1031 
1032   // if successful, ret is the number of samples actually retrieved.
1033   assert(ret >= 0 && ret <= max_nelem, "Unexpected loadavg return value");
1034   switch(ret) {
1035     case 3: a->double_at_put(2, (jdouble)la[2]); // fall through
1036     case 2: a->double_at_put(1, (jdouble)la[1]); // fall through
1037     case 1: a->double_at_put(0, (jdouble)la[0]); break;
1038   }
1039 
1040   return ret;
1041 } UNSAFE_END
1042 
1043 
1044 /// JVM_RegisterUnsafeMethods
1045 
1046 #define ADR "J"
1047 
1048 #define LANG "Ljava/lang/"
1049 
1050 #define OBJ LANG "Object;"
1051 #define CLS LANG "Class;"
1052 #define FLD LANG "reflect/Field;"
1053 #define THR LANG "Throwable;"
1054 
1055 #define DC_Args  LANG "String;[BII" LANG "ClassLoader;" "Ljava/security/ProtectionDomain;"
1056 #define DAC_Args CLS "[B[" OBJ
1057 
1058 #define CC (char*)  /*cast a literal from (const char*)*/
1059 #define FN_PTR(f) CAST_FROM_FN_PTR(void*, &f)
1060 
1061 #define DECLARE_GETPUTOOP(Type, Desc) \
1062     {CC "get" #Type,      CC "(" OBJ "J)" #Desc,       FN_PTR(Unsafe_Get##Type)}, \
1063     {CC "put" #Type,      CC "(" OBJ "J" #Desc ")V",   FN_PTR(Unsafe_Put##Type)}, \
1064     {CC "get" #Type "Volatile",      CC "(" OBJ "J)" #Desc,       FN_PTR(Unsafe_Get##Type##Volatile)}, \
1065     {CC "put" #Type "Volatile",      CC "(" OBJ "J" #Desc ")V",   FN_PTR(Unsafe_Put##Type##Volatile)}
1066 
1067 
1068 static JNINativeMethod jdk_internal_misc_Unsafe_methods[] = {
1069     {CC "getReference",         CC "(" OBJ "J)" OBJ "",   FN_PTR(Unsafe_GetReference)},
1070     {CC "putReference",         CC "(" OBJ "J" OBJ ")V",  FN_PTR(Unsafe_PutReference)},
1071     {CC "getReferenceVolatile", CC "(" OBJ "J)" OBJ,      FN_PTR(Unsafe_GetReferenceVolatile)},
1072     {CC "putReferenceVolatile", CC "(" OBJ "J" OBJ ")V",  FN_PTR(Unsafe_PutReferenceVolatile)},
1073 
1074     {CC "getUncompressedObject", CC "(" ADR ")" OBJ,  FN_PTR(Unsafe_GetUncompressedObject)},
1075 
1076     DECLARE_GETPUTOOP(Boolean, Z),
1077     DECLARE_GETPUTOOP(Byte, B),
1078     DECLARE_GETPUTOOP(Short, S),
1079     DECLARE_GETPUTOOP(Char, C),
1080     DECLARE_GETPUTOOP(Int, I),
1081     DECLARE_GETPUTOOP(Long, J),
1082     DECLARE_GETPUTOOP(Float, F),
1083     DECLARE_GETPUTOOP(Double, D),
1084 
1085     {CC "allocateMemory0",    CC "(J)" ADR,              FN_PTR(Unsafe_AllocateMemory0)},
1086     {CC "reallocateMemory0",  CC "(" ADR "J)" ADR,       FN_PTR(Unsafe_ReallocateMemory0)},
1087     {CC "freeMemory0",        CC "(" ADR ")V",           FN_PTR(Unsafe_FreeMemory0)},
1088 
1089     {CC "objectFieldOffset0", CC "(" FLD ")J",           FN_PTR(Unsafe_ObjectFieldOffset0)},
1090     {CC "objectFieldOffset1", CC "(" CLS LANG "String;)J", FN_PTR(Unsafe_ObjectFieldOffset1)},
1091     {CC "staticFieldOffset0", CC "(" FLD ")J",           FN_PTR(Unsafe_StaticFieldOffset0)},
1092     {CC "staticFieldBase0",   CC "(" FLD ")" OBJ,        FN_PTR(Unsafe_StaticFieldBase0)},
1093     {CC "ensureClassInitialized0", CC "(" CLS ")V",      FN_PTR(Unsafe_EnsureClassInitialized0)},
1094     {CC "arrayBaseOffset0",   CC "(" CLS ")I",           FN_PTR(Unsafe_ArrayBaseOffset0)},
1095     {CC "arrayIndexScale0",   CC "(" CLS ")I",           FN_PTR(Unsafe_ArrayIndexScale0)},
1096 
1097     {CC "defineClass0",       CC "(" DC_Args ")" CLS,    FN_PTR(Unsafe_DefineClass0)},
1098     {CC "allocateInstance",   CC "(" CLS ")" OBJ,        FN_PTR(Unsafe_AllocateInstance)},
1099     {CC "throwException",     CC "(" THR ")V",           FN_PTR(Unsafe_ThrowException)},
1100     {CC "compareAndSetReference",CC "(" OBJ "J" OBJ "" OBJ ")Z", FN_PTR(Unsafe_CompareAndSetReference)},
1101     {CC "compareAndSetInt",   CC "(" OBJ "J""I""I"")Z",  FN_PTR(Unsafe_CompareAndSetInt)},
1102     {CC "compareAndSetLong",  CC "(" OBJ "J""J""J"")Z",  FN_PTR(Unsafe_CompareAndSetLong)},
1103     {CC "compareAndExchangeReference", CC "(" OBJ "J" OBJ "" OBJ ")" OBJ, FN_PTR(Unsafe_CompareAndExchangeReference)},
1104     {CC "compareAndExchangeInt",  CC "(" OBJ "J""I""I"")I", FN_PTR(Unsafe_CompareAndExchangeInt)},
1105     {CC "compareAndExchangeLong", CC "(" OBJ "J""J""J"")J", FN_PTR(Unsafe_CompareAndExchangeLong)},
1106 
1107     {CC "park",               CC "(ZJ)V",                FN_PTR(Unsafe_Park)},
1108     {CC "unpark",             CC "(" OBJ ")V",           FN_PTR(Unsafe_Unpark)},
1109 
1110     {CC "getLoadAverage0",    CC "([DI)I",               FN_PTR(Unsafe_GetLoadAverage0)},
1111 
1112     {CC "copyMemory0",        CC "(" OBJ "J" OBJ "JJ)V", FN_PTR(Unsafe_CopyMemory0)},
1113     {CC "copySwapMemory0",    CC "(" OBJ "J" OBJ "JJJ)V", FN_PTR(Unsafe_CopySwapMemory0)},
1114     {CC "writeback0",         CC "(" "J" ")V",           FN_PTR(Unsafe_WriteBack0)},
1115     {CC "writebackPreSync0",  CC "()V",                  FN_PTR(Unsafe_WriteBackPreSync0)},
1116     {CC "writebackPostSync0", CC "()V",                  FN_PTR(Unsafe_WriteBackPostSync0)},
1117     {CC "setMemory0",         CC "(" OBJ "JJB)V",        FN_PTR(Unsafe_SetMemory0)},
1118 
1119     {CC "defineAnonymousClass0", CC "(" DAC_Args ")" CLS, FN_PTR(Unsafe_DefineAnonymousClass0)},
1120 
1121     {CC "shouldBeInitialized0", CC "(" CLS ")Z",         FN_PTR(Unsafe_ShouldBeInitialized0)},
1122 
1123     {CC "loadFence",          CC "()V",                  FN_PTR(Unsafe_LoadFence)},
1124     {CC "storeFence",         CC "()V",                  FN_PTR(Unsafe_StoreFence)},
1125     {CC "fullFence",          CC "()V",                  FN_PTR(Unsafe_FullFence)},
1126 };
1127 
1128 #undef CC
1129 #undef FN_PTR
1130 
1131 #undef ADR
1132 #undef LANG
1133 #undef OBJ
1134 #undef CLS
1135 #undef FLD
1136 #undef THR
1137 #undef DC_Args
1138 #undef DAC_Args
1139 
1140 #undef DECLARE_GETPUTOOP
1141 
1142 
1143 // This function is exported, used by NativeLookup.
1144 // The Unsafe_xxx functions above are called only from the interpreter.
1145 // The optimizer looks at names and signatures to recognize
1146 // individual functions.
1147 
1148 JVM_ENTRY(void, JVM_RegisterJDKInternalMiscUnsafeMethods(JNIEnv *env, jclass unsafeclass)) {
1149   ThreadToNativeFromVM ttnfv(thread);
1150 
1151   int ok = env->RegisterNatives(unsafeclass, jdk_internal_misc_Unsafe_methods, sizeof(jdk_internal_misc_Unsafe_methods)/sizeof(JNINativeMethod));
1152   guarantee(ok == 0, "register jdk.internal.misc.Unsafe natives");
1153 } JVM_END