1 /*
   2  * Copyright (c) 2000, 2016, 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 "classfile/vmSymbols.hpp"
  27 #include "utilities/macros.hpp"
  28 #if INCLUDE_ALL_GCS
  29 #include "gc_implementation/g1/g1SATBCardTableModRefBS.hpp"
  30 #endif // INCLUDE_ALL_GCS
  31 #include "memory/allocation.inline.hpp"
  32 #include "prims/jni.h"
  33 #include "prims/jvm.h"
  34 #include "runtime/globals.hpp"
  35 #include "runtime/interfaceSupport.hpp"
  36 #include "runtime/prefetch.inline.hpp"
  37 #include "runtime/orderAccess.inline.hpp"
  38 #include "runtime/reflection.hpp"
  39 #include "runtime/synchronizer.hpp"
  40 #include "services/threadService.hpp"
  41 #include "trace/tracing.hpp"
  42 #include "utilities/copy.hpp"
  43 #include "utilities/dtrace.hpp"
  44 
  45 PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC
  46 
  47 /*
  48  *      Implementation of class sun.misc.Unsafe
  49  */
  50 
  51 #ifndef USDT2
  52 HS_DTRACE_PROBE_DECL3(hotspot, thread__park__begin, uintptr_t, int, long long);
  53 HS_DTRACE_PROBE_DECL1(hotspot, thread__park__end, uintptr_t);
  54 HS_DTRACE_PROBE_DECL1(hotspot, thread__unpark, uintptr_t);
  55 #endif /* !USDT2 */
  56 
  57 #define MAX_OBJECT_SIZE \
  58   ( arrayOopDesc::header_size(T_DOUBLE) * HeapWordSize \
  59     + ((julong)max_jint * sizeof(double)) )
  60 
  61 
  62 #define UNSAFE_ENTRY(result_type, header) \
  63   JVM_ENTRY(result_type, header)
  64 
  65 // Can't use UNSAFE_LEAF because it has the signature of a straight
  66 // call into the runtime (just like JVM_LEAF, funny that) but it's
  67 // called like a Java Native and thus the wrapper built for it passes
  68 // arguments like a JNI call.  It expects those arguments to be popped
  69 // from the stack on Intel like all good JNI args are, and adjusts the
  70 // stack according.  Since the JVM_LEAF call expects no extra
  71 // arguments the stack isn't popped in the C code, is pushed by the
  72 // wrapper and we get sick.
  73 //#define UNSAFE_LEAF(result_type, header) \
  74 //  JVM_LEAF(result_type, header)
  75 
  76 #define UNSAFE_END JVM_END
  77 
  78 #define UnsafeWrapper(arg) /*nothing, for the present*/
  79 
  80 
  81 inline void* addr_from_java(jlong addr) {
  82   // This assert fails in a variety of ways on 32-bit systems.
  83   // It is impossible to predict whether native code that converts
  84   // pointers to longs will sign-extend or zero-extend the addresses.
  85   //assert(addr == (uintptr_t)addr, "must not be odd high bits");
  86   return (void*)(uintptr_t)addr;
  87 }
  88 
  89 inline jlong addr_to_java(void* p) {
  90   assert(p == (void*)(uintptr_t)p, "must not be odd high bits");
  91   return (uintptr_t)p;
  92 }
  93 
  94 
  95 // Note: The VM's obj_field and related accessors use byte-scaled
  96 // ("unscaled") offsets, just as the unsafe methods do.
  97 
  98 // However, the method Unsafe.fieldOffset explicitly declines to
  99 // guarantee this.  The field offset values manipulated by the Java user
 100 // through the Unsafe API are opaque cookies that just happen to be byte
 101 // offsets.  We represent this state of affairs by passing the cookies
 102 // through conversion functions when going between the VM and the Unsafe API.
 103 // The conversion functions just happen to be no-ops at present.
 104 
 105 inline jlong field_offset_to_byte_offset(jlong field_offset) {
 106   return field_offset;
 107 }
 108 
 109 inline jlong field_offset_from_byte_offset(jlong byte_offset) {
 110   return byte_offset;
 111 }
 112 
 113 inline jint invocation_key_from_method_slot(jint slot) {
 114   return slot;
 115 }
 116 
 117 inline jint invocation_key_to_method_slot(jint key) {
 118   return key;
 119 }
 120 
 121 inline void* index_oop_from_field_offset_long(oop p, jlong field_offset) {
 122   jlong byte_offset = field_offset_to_byte_offset(field_offset);
 123 #ifdef ASSERT
 124   if (p != NULL) {
 125     assert(byte_offset >= 0 && byte_offset <= (jlong)MAX_OBJECT_SIZE, "sane offset");
 126     if (byte_offset == (jint)byte_offset) {
 127       void* ptr_plus_disp = (address)p + byte_offset;
 128       assert((void*)p->obj_field_addr<oop>((jint)byte_offset) == ptr_plus_disp,
 129              "raw [ptr+disp] must be consistent with oop::field_base");
 130     }
 131     jlong p_size = HeapWordSize * (jlong)(p->size());
 132     assert(byte_offset < p_size, err_msg("Unsafe access: offset " INT64_FORMAT " > object's size " INT64_FORMAT, byte_offset, p_size));
 133   }
 134 #endif
 135   if (sizeof(char*) == sizeof(jint))    // (this constant folds!)
 136     return (address)p + (jint) byte_offset;
 137   else
 138     return (address)p +        byte_offset;
 139 }
 140 
 141 // Externally callable versions:
 142 // (Use these in compiler intrinsics which emulate unsafe primitives.)
 143 jlong Unsafe_field_offset_to_byte_offset(jlong field_offset) {
 144   return field_offset;
 145 }
 146 jlong Unsafe_field_offset_from_byte_offset(jlong byte_offset) {
 147   return byte_offset;
 148 }
 149 jint Unsafe_invocation_key_from_method_slot(jint slot) {
 150   return invocation_key_from_method_slot(slot);
 151 }
 152 jint Unsafe_invocation_key_to_method_slot(jint key) {
 153   return invocation_key_to_method_slot(key);
 154 }
 155 
 156 
 157 ///// Data in the Java heap.
 158 
 159 #define truncate_jboolean(x) ((x) & 1)
 160 #define truncate_jbyte(x) (x)
 161 #define truncate_jshort(x) (x)
 162 #define truncate_jchar(x) (x)
 163 #define truncate_jint(x) (x)
 164 #define truncate_jlong(x) (x)
 165 #define truncate_jfloat(x) (x)
 166 #define truncate_jdouble(x) (x)
 167 
 168 #define GET_FIELD(obj, offset, type_name, v) \
 169   oop p = JNIHandles::resolve(obj); \
 170   type_name v = *(type_name*)index_oop_from_field_offset_long(p, offset)
 171 
 172 #define SET_FIELD(obj, offset, type_name, x) \
 173   oop p = JNIHandles::resolve(obj); \
 174   *(type_name*)index_oop_from_field_offset_long(p, offset) = truncate_##type_name(x)
 175 
 176 #define GET_FIELD_VOLATILE(obj, offset, type_name, v) \
 177   oop p = JNIHandles::resolve(obj); \
 178   if (support_IRIW_for_not_multiple_copy_atomic_cpu) { \
 179     OrderAccess::fence(); \
 180   } \
 181   volatile type_name v = OrderAccess::load_acquire((volatile type_name*)index_oop_from_field_offset_long(p, offset));
 182 
 183 #define SET_FIELD_VOLATILE(obj, offset, type_name, x) \
 184   oop p = JNIHandles::resolve(obj); \
 185   OrderAccess::release_store_fence((volatile type_name*)index_oop_from_field_offset_long(p, offset), truncate_##type_name(x));
 186 
 187 // Macros for oops that check UseCompressedOops
 188 
 189 #define GET_OOP_FIELD(obj, offset, v) \
 190   oop p = JNIHandles::resolve(obj);   \
 191   oop v;                              \
 192   if (UseCompressedOops) {            \
 193     narrowOop n = *(narrowOop*)index_oop_from_field_offset_long(p, offset); \
 194     v = oopDesc::decode_heap_oop(n);                                \
 195   } else {                            \
 196     v = *(oop*)index_oop_from_field_offset_long(p, offset);                 \
 197   }
 198 
 199 
 200 // Get/SetObject must be special-cased, since it works with handles.
 201 
 202 // The xxx140 variants for backward compatibility do not allow a full-width offset.
 203 UNSAFE_ENTRY(jobject, Unsafe_GetObject140(JNIEnv *env, jobject unsafe, jobject obj, jint offset))
 204   UnsafeWrapper("Unsafe_GetObject");
 205   if (obj == NULL)  THROW_0(vmSymbols::java_lang_NullPointerException());
 206   GET_OOP_FIELD(obj, offset, v)
 207   jobject ret = JNIHandles::make_local(env, v);
 208 #if INCLUDE_ALL_GCS
 209   // We could be accessing the referent field in a reference
 210   // object. If G1 is enabled then we need to register a non-null
 211   // referent with the SATB barrier.
 212   if (UseG1GC) {
 213     bool needs_barrier = false;
 214 
 215     if (ret != NULL) {
 216       if (offset == java_lang_ref_Reference::referent_offset) {
 217         oop o = JNIHandles::resolve_non_null(obj);
 218         Klass* k = o->klass();
 219         if (InstanceKlass::cast(k)->reference_type() != REF_NONE) {
 220           assert(InstanceKlass::cast(k)->is_subclass_of(SystemDictionary::Reference_klass()), "sanity");
 221           needs_barrier = true;
 222         }
 223       }
 224     }
 225 
 226     if (needs_barrier) {
 227       oop referent = JNIHandles::resolve(ret);
 228       G1SATBCardTableModRefBS::enqueue(referent);
 229     }
 230   }
 231 #endif // INCLUDE_ALL_GCS
 232   return ret;
 233 UNSAFE_END
 234 
 235 UNSAFE_ENTRY(void, Unsafe_SetObject140(JNIEnv *env, jobject unsafe, jobject obj, jint offset, jobject x_h))
 236   UnsafeWrapper("Unsafe_SetObject");
 237   if (obj == NULL)  THROW(vmSymbols::java_lang_NullPointerException());
 238   oop x = JNIHandles::resolve(x_h);
 239   //SET_FIELD(obj, offset, oop, x);
 240   oop p = JNIHandles::resolve(obj);
 241   if (UseCompressedOops) {
 242     if (x != NULL) {
 243       // If there is a heap base pointer, we are obliged to emit a store barrier.
 244       oop_store((narrowOop*)index_oop_from_field_offset_long(p, offset), x);
 245     } else {
 246       narrowOop n = oopDesc::encode_heap_oop_not_null(x);
 247       *(narrowOop*)index_oop_from_field_offset_long(p, offset) = n;
 248     }
 249   } else {
 250     if (x != NULL) {
 251       // If there is a heap base pointer, we are obliged to emit a store barrier.
 252       oop_store((oop*)index_oop_from_field_offset_long(p, offset), x);
 253     } else {
 254       *(oop*)index_oop_from_field_offset_long(p, offset) = x;
 255     }
 256   }
 257 UNSAFE_END
 258 
 259 // The normal variants 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_GetObject(JNIEnv *env, jobject unsafe, jobject obj, jlong offset))
 263   UnsafeWrapper("Unsafe_GetObject");
 264   GET_OOP_FIELD(obj, offset, v)
 265   jobject ret = JNIHandles::make_local(env, v);
 266 #if INCLUDE_ALL_GCS
 267   // We could be accessing the referent field in a reference
 268   // object. If G1 is enabled then we need to register non-null
 269   // referent with the SATB barrier.
 270   if (UseG1GC) {
 271     bool needs_barrier = false;
 272 
 273     if (ret != NULL) {
 274       if (offset == java_lang_ref_Reference::referent_offset && obj != NULL) {
 275         oop o = JNIHandles::resolve(obj);
 276         Klass* k = o->klass();
 277         if (InstanceKlass::cast(k)->reference_type() != REF_NONE) {
 278           assert(InstanceKlass::cast(k)->is_subclass_of(SystemDictionary::Reference_klass()), "sanity");
 279           needs_barrier = true;
 280         }
 281       }
 282     }
 283 
 284     if (needs_barrier) {
 285       oop referent = JNIHandles::resolve(ret);
 286       G1SATBCardTableModRefBS::enqueue(referent);
 287     }
 288   }
 289 #endif // INCLUDE_ALL_GCS
 290   return ret;
 291 UNSAFE_END
 292 
 293 UNSAFE_ENTRY(void, Unsafe_SetObject(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jobject x_h))
 294   UnsafeWrapper("Unsafe_SetObject");
 295   oop x = JNIHandles::resolve(x_h);
 296   oop p = JNIHandles::resolve(obj);
 297   if (UseCompressedOops) {
 298     oop_store((narrowOop*)index_oop_from_field_offset_long(p, offset), x);
 299   } else {
 300     oop_store((oop*)index_oop_from_field_offset_long(p, offset), x);
 301   }
 302 UNSAFE_END
 303 
 304 UNSAFE_ENTRY(jobject, Unsafe_GetObjectVolatile(JNIEnv *env, jobject unsafe, jobject obj, jlong offset))
 305   UnsafeWrapper("Unsafe_GetObjectVolatile");
 306   oop p = JNIHandles::resolve(obj);
 307   void* addr = index_oop_from_field_offset_long(p, offset);
 308   volatile oop v;
 309   if (UseCompressedOops) {
 310     volatile narrowOop n = *(volatile narrowOop*) addr;
 311     (void)const_cast<oop&>(v = oopDesc::decode_heap_oop(n));
 312   } else {
 313     (void)const_cast<oop&>(v = *(volatile oop*) addr);
 314   }
 315   OrderAccess::acquire();
 316   return JNIHandles::make_local(env, v);
 317 UNSAFE_END
 318 
 319 UNSAFE_ENTRY(void, Unsafe_SetObjectVolatile(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jobject x_h))
 320   UnsafeWrapper("Unsafe_SetObjectVolatile");
 321   oop x = JNIHandles::resolve(x_h);
 322   oop p = JNIHandles::resolve(obj);
 323   void* addr = index_oop_from_field_offset_long(p, offset);
 324   OrderAccess::release();
 325   if (UseCompressedOops) {
 326     oop_store((narrowOop*)addr, x);
 327   } else {
 328     oop_store((oop*)addr, x);
 329   }
 330   OrderAccess::fence();
 331 UNSAFE_END
 332 
 333 #ifndef SUPPORTS_NATIVE_CX8
 334 
 335 // VM_Version::supports_cx8() is a surrogate for 'supports atomic long memory ops'.
 336 //
 337 // On platforms which do not support atomic compare-and-swap of jlong (8 byte)
 338 // values we have to use a lock-based scheme to enforce atomicity. This has to be
 339 // applied to all Unsafe operations that set the value of a jlong field. Even so
 340 // the compareAndSwapLong operation will not be atomic with respect to direct stores
 341 // to the field from Java code. It is important therefore that any Java code that
 342 // utilizes these Unsafe jlong operations does not perform direct stores. To permit
 343 // direct loads of the field from Java code we must also use Atomic::store within the
 344 // locked regions. And for good measure, in case there are direct stores, we also
 345 // employ Atomic::load within those regions. Note that the field in question must be
 346 // volatile and so must have atomic load/store accesses applied at the Java level.
 347 //
 348 // The locking scheme could utilize a range of strategies for controlling the locking
 349 // granularity: from a lock per-field through to a single global lock. The latter is
 350 // the simplest and is used for the current implementation. Note that the Java object
 351 // that contains the field, can not, in general, be used for locking. To do so can lead
 352 // to deadlocks as we may introduce locking into what appears to the Java code to be a
 353 // lock-free path.
 354 //
 355 // As all the locked-regions are very short and themselves non-blocking we can treat
 356 // them as leaf routines and elide safepoint checks (ie we don't perform any thread
 357 // state transitions even when blocking for the lock). Note that if we do choose to
 358 // add safepoint checks and thread state transitions, we must ensure that we calculate
 359 // the address of the field _after_ we have acquired the lock, else the object may have
 360 // been moved by the GC
 361 
 362 UNSAFE_ENTRY(jlong, Unsafe_GetLongVolatile(JNIEnv *env, jobject unsafe, jobject obj, jlong offset))
 363   UnsafeWrapper("Unsafe_GetLongVolatile");
 364   {
 365     if (VM_Version::supports_cx8()) {
 366       GET_FIELD_VOLATILE(obj, offset, jlong, v);
 367       return v;
 368     }
 369     else {
 370       Handle p (THREAD, JNIHandles::resolve(obj));
 371       jlong* addr = (jlong*)(index_oop_from_field_offset_long(p(), offset));
 372       MutexLockerEx mu(UnsafeJlong_lock, Mutex::_no_safepoint_check_flag);
 373       jlong value = Atomic::load(addr);
 374       return value;
 375     }
 376   }
 377 UNSAFE_END
 378 
 379 UNSAFE_ENTRY(void, Unsafe_SetLongVolatile(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jlong x))
 380   UnsafeWrapper("Unsafe_SetLongVolatile");
 381   {
 382     if (VM_Version::supports_cx8()) {
 383       SET_FIELD_VOLATILE(obj, offset, jlong, x);
 384     }
 385     else {
 386       Handle p (THREAD, JNIHandles::resolve(obj));
 387       jlong* addr = (jlong*)(index_oop_from_field_offset_long(p(), offset));
 388       MutexLockerEx mu(UnsafeJlong_lock, Mutex::_no_safepoint_check_flag);
 389       Atomic::store(x, addr);
 390     }
 391   }
 392 UNSAFE_END
 393 
 394 #endif // not SUPPORTS_NATIVE_CX8
 395 
 396 #define DEFINE_GETSETOOP(jboolean, Boolean) \
 397  \
 398 UNSAFE_ENTRY(jboolean, Unsafe_Get##Boolean##140(JNIEnv *env, jobject unsafe, jobject obj, jint offset)) \
 399   UnsafeWrapper("Unsafe_Get"#Boolean); \
 400   if (obj == NULL)  THROW_0(vmSymbols::java_lang_NullPointerException()); \
 401   GET_FIELD(obj, offset, jboolean, v); \
 402   return v; \
 403 UNSAFE_END \
 404  \
 405 UNSAFE_ENTRY(void, Unsafe_Set##Boolean##140(JNIEnv *env, jobject unsafe, jobject obj, jint offset, jboolean x)) \
 406   UnsafeWrapper("Unsafe_Set"#Boolean); \
 407   if (obj == NULL)  THROW(vmSymbols::java_lang_NullPointerException()); \
 408   SET_FIELD(obj, offset, jboolean, x); \
 409 UNSAFE_END \
 410  \
 411 UNSAFE_ENTRY(jboolean, Unsafe_Get##Boolean(JNIEnv *env, jobject unsafe, jobject obj, jlong offset)) \
 412   UnsafeWrapper("Unsafe_Get"#Boolean); \
 413   GET_FIELD(obj, offset, jboolean, v); \
 414   return v; \
 415 UNSAFE_END \
 416  \
 417 UNSAFE_ENTRY(void, Unsafe_Set##Boolean(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jboolean x)) \
 418   UnsafeWrapper("Unsafe_Set"#Boolean); \
 419   SET_FIELD(obj, offset, jboolean, x); \
 420 UNSAFE_END \
 421  \
 422 // END DEFINE_GETSETOOP.
 423 
 424 DEFINE_GETSETOOP(jboolean, Boolean)
 425 DEFINE_GETSETOOP(jbyte, Byte)
 426 DEFINE_GETSETOOP(jshort, Short);
 427 DEFINE_GETSETOOP(jchar, Char);
 428 DEFINE_GETSETOOP(jint, Int);
 429 DEFINE_GETSETOOP(jlong, Long);
 430 DEFINE_GETSETOOP(jfloat, Float);
 431 DEFINE_GETSETOOP(jdouble, Double);
 432 
 433 #undef DEFINE_GETSETOOP
 434 
 435 #define DEFINE_GETSETOOP_VOLATILE(jboolean, Boolean) \
 436  \
 437 UNSAFE_ENTRY(jboolean, Unsafe_Get##Boolean##Volatile(JNIEnv *env, jobject unsafe, jobject obj, jlong offset)) \
 438   UnsafeWrapper("Unsafe_Get"#Boolean); \
 439   GET_FIELD_VOLATILE(obj, offset, jboolean, v); \
 440   return v; \
 441 UNSAFE_END \
 442  \
 443 UNSAFE_ENTRY(void, Unsafe_Set##Boolean##Volatile(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jboolean x)) \
 444   UnsafeWrapper("Unsafe_Set"#Boolean); \
 445   SET_FIELD_VOLATILE(obj, offset, jboolean, x); \
 446 UNSAFE_END \
 447  \
 448 // END DEFINE_GETSETOOP_VOLATILE.
 449 
 450 DEFINE_GETSETOOP_VOLATILE(jboolean, Boolean)
 451 DEFINE_GETSETOOP_VOLATILE(jbyte, Byte)
 452 DEFINE_GETSETOOP_VOLATILE(jshort, Short);
 453 DEFINE_GETSETOOP_VOLATILE(jchar, Char);
 454 DEFINE_GETSETOOP_VOLATILE(jint, Int);
 455 DEFINE_GETSETOOP_VOLATILE(jfloat, Float);
 456 DEFINE_GETSETOOP_VOLATILE(jdouble, Double);
 457 
 458 #ifdef SUPPORTS_NATIVE_CX8
 459 DEFINE_GETSETOOP_VOLATILE(jlong, Long);
 460 #endif
 461 
 462 #undef DEFINE_GETSETOOP_VOLATILE
 463 
 464 // The non-intrinsified versions of setOrdered just use setVolatile
 465 
 466 UNSAFE_ENTRY(void, Unsafe_SetOrderedInt(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jint x))
 467   UnsafeWrapper("Unsafe_SetOrderedInt");
 468   SET_FIELD_VOLATILE(obj, offset, jint, x);
 469 UNSAFE_END
 470 
 471 UNSAFE_ENTRY(void, Unsafe_SetOrderedObject(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jobject x_h))
 472   UnsafeWrapper("Unsafe_SetOrderedObject");
 473   oop x = JNIHandles::resolve(x_h);
 474   oop p = JNIHandles::resolve(obj);
 475   void* addr = index_oop_from_field_offset_long(p, offset);
 476   OrderAccess::release();
 477   if (UseCompressedOops) {
 478     oop_store((narrowOop*)addr, x);
 479   } else {
 480     oop_store((oop*)addr, x);
 481   }
 482   OrderAccess::fence();
 483 UNSAFE_END
 484 
 485 UNSAFE_ENTRY(void, Unsafe_SetOrderedLong(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jlong x))
 486   UnsafeWrapper("Unsafe_SetOrderedLong");
 487 #ifdef SUPPORTS_NATIVE_CX8
 488   SET_FIELD_VOLATILE(obj, offset, jlong, x);
 489 #else
 490   // Keep old code for platforms which may not have atomic long (8 bytes) instructions
 491   {
 492     if (VM_Version::supports_cx8()) {
 493       SET_FIELD_VOLATILE(obj, offset, jlong, x);
 494     }
 495     else {
 496       Handle p (THREAD, JNIHandles::resolve(obj));
 497       jlong* addr = (jlong*)(index_oop_from_field_offset_long(p(), offset));
 498       MutexLockerEx mu(UnsafeJlong_lock, Mutex::_no_safepoint_check_flag);
 499       Atomic::store(x, addr);
 500     }
 501   }
 502 #endif
 503 UNSAFE_END
 504 
 505 UNSAFE_ENTRY(void, Unsafe_LoadFence(JNIEnv *env, jobject unsafe))
 506   UnsafeWrapper("Unsafe_LoadFence");
 507   OrderAccess::acquire();
 508 UNSAFE_END
 509 
 510 UNSAFE_ENTRY(void, Unsafe_StoreFence(JNIEnv *env, jobject unsafe))
 511   UnsafeWrapper("Unsafe_StoreFence");
 512   OrderAccess::release();
 513 UNSAFE_END
 514 
 515 UNSAFE_ENTRY(void, Unsafe_FullFence(JNIEnv *env, jobject unsafe))
 516   UnsafeWrapper("Unsafe_FullFence");
 517   OrderAccess::fence();
 518 UNSAFE_END
 519 
 520 ////// Data in the C heap.
 521 
 522 // Note:  These do not throw NullPointerException for bad pointers.
 523 // They just crash.  Only a oop base pointer can generate a NullPointerException.
 524 //
 525 #define DEFINE_GETSETNATIVE(java_type, Type, native_type) \
 526  \
 527 UNSAFE_ENTRY(java_type, Unsafe_GetNative##Type(JNIEnv *env, jobject unsafe, jlong addr)) \
 528   UnsafeWrapper("Unsafe_GetNative"#Type); \
 529   void* p = addr_from_java(addr); \
 530   JavaThread* t = JavaThread::current(); \
 531   t->set_doing_unsafe_access(true); \
 532   java_type x = *(volatile native_type*)p; \
 533   t->set_doing_unsafe_access(false); \
 534   return x; \
 535 UNSAFE_END \
 536  \
 537 UNSAFE_ENTRY(void, Unsafe_SetNative##Type(JNIEnv *env, jobject unsafe, jlong addr, java_type x)) \
 538   UnsafeWrapper("Unsafe_SetNative"#Type); \
 539   JavaThread* t = JavaThread::current(); \
 540   t->set_doing_unsafe_access(true); \
 541   void* p = addr_from_java(addr); \
 542   *(volatile native_type*)p = x; \
 543   t->set_doing_unsafe_access(false); \
 544 UNSAFE_END \
 545  \
 546 // END DEFINE_GETSETNATIVE.
 547 
 548 DEFINE_GETSETNATIVE(jbyte, Byte, signed char)
 549 DEFINE_GETSETNATIVE(jshort, Short, signed short);
 550 DEFINE_GETSETNATIVE(jchar, Char, unsigned short);
 551 DEFINE_GETSETNATIVE(jint, Int, jint);
 552 // no long -- handled specially
 553 DEFINE_GETSETNATIVE(jfloat, Float, float);
 554 DEFINE_GETSETNATIVE(jdouble, Double, double);
 555 
 556 #undef DEFINE_GETSETNATIVE
 557 
 558 UNSAFE_ENTRY(jlong, Unsafe_GetNativeLong(JNIEnv *env, jobject unsafe, jlong addr))
 559   UnsafeWrapper("Unsafe_GetNativeLong");
 560   JavaThread* t = JavaThread::current();
 561   // We do it this way to avoid problems with access to heap using 64
 562   // bit loads, as jlong in heap could be not 64-bit aligned, and on
 563   // some CPUs (SPARC) it leads to SIGBUS.
 564   t->set_doing_unsafe_access(true);
 565   void* p = addr_from_java(addr);
 566   jlong x;
 567   if (((intptr_t)p & 7) == 0) {
 568     // jlong is aligned, do a volatile access
 569     x = *(volatile jlong*)p;
 570   } else {
 571     jlong_accessor acc;
 572     acc.words[0] = ((volatile jint*)p)[0];
 573     acc.words[1] = ((volatile jint*)p)[1];
 574     x = acc.long_value;
 575   }
 576   t->set_doing_unsafe_access(false);
 577   return x;
 578 UNSAFE_END
 579 
 580 UNSAFE_ENTRY(void, Unsafe_SetNativeLong(JNIEnv *env, jobject unsafe, jlong addr, jlong x))
 581   UnsafeWrapper("Unsafe_SetNativeLong");
 582   JavaThread* t = JavaThread::current();
 583   // see comment for Unsafe_GetNativeLong
 584   t->set_doing_unsafe_access(true);
 585   void* p = addr_from_java(addr);
 586   if (((intptr_t)p & 7) == 0) {
 587     // jlong is aligned, do a volatile access
 588     *(volatile jlong*)p = x;
 589   } else {
 590     jlong_accessor acc;
 591     acc.long_value = x;
 592     ((volatile jint*)p)[0] = acc.words[0];
 593     ((volatile jint*)p)[1] = acc.words[1];
 594   }
 595   t->set_doing_unsafe_access(false);
 596 UNSAFE_END
 597 
 598 
 599 UNSAFE_ENTRY(jlong, Unsafe_GetNativeAddress(JNIEnv *env, jobject unsafe, jlong addr))
 600   UnsafeWrapper("Unsafe_GetNativeAddress");
 601   void* p = addr_from_java(addr);
 602   return addr_to_java(*(void**)p);
 603 UNSAFE_END
 604 
 605 UNSAFE_ENTRY(void, Unsafe_SetNativeAddress(JNIEnv *env, jobject unsafe, jlong addr, jlong x))
 606   UnsafeWrapper("Unsafe_SetNativeAddress");
 607   void* p = addr_from_java(addr);
 608   *(void**)p = addr_from_java(x);
 609 UNSAFE_END
 610 
 611 
 612 ////// Allocation requests
 613 
 614 UNSAFE_ENTRY(jobject, Unsafe_AllocateInstance(JNIEnv *env, jobject unsafe, jclass cls))
 615   UnsafeWrapper("Unsafe_AllocateInstance");
 616   {
 617     ThreadToNativeFromVM ttnfv(thread);
 618     return env->AllocObject(cls);
 619   }
 620 UNSAFE_END
 621 
 622 UNSAFE_ENTRY(jlong, Unsafe_AllocateMemory(JNIEnv *env, jobject unsafe, jlong size))
 623   UnsafeWrapper("Unsafe_AllocateMemory");
 624   size_t sz = (size_t)size;
 625   if (sz != (julong)size || size < 0) {
 626     THROW_0(vmSymbols::java_lang_IllegalArgumentException());
 627   }
 628   if (sz == 0) {
 629     return 0;
 630   }
 631   sz = round_to(sz, HeapWordSize);
 632   void* x = os::malloc(sz, mtInternal);
 633   if (x == NULL) {
 634     THROW_0(vmSymbols::java_lang_OutOfMemoryError());
 635   }
 636   //Copy::fill_to_words((HeapWord*)x, sz / HeapWordSize);
 637   return addr_to_java(x);
 638 UNSAFE_END
 639 
 640 UNSAFE_ENTRY(jlong, Unsafe_ReallocateMemory(JNIEnv *env, jobject unsafe, jlong addr, jlong size))
 641   UnsafeWrapper("Unsafe_ReallocateMemory");
 642   void* p = addr_from_java(addr);
 643   size_t sz = (size_t)size;
 644   if (sz != (julong)size || size < 0) {
 645     THROW_0(vmSymbols::java_lang_IllegalArgumentException());
 646   }
 647   if (sz == 0) {
 648     os::free(p);
 649     return 0;
 650   }
 651   sz = round_to(sz, HeapWordSize);
 652   void* x = (p == NULL) ? os::malloc(sz, mtInternal) : os::realloc(p, sz, mtInternal);
 653   if (x == NULL) {
 654     THROW_0(vmSymbols::java_lang_OutOfMemoryError());
 655   }
 656   return addr_to_java(x);
 657 UNSAFE_END
 658 
 659 UNSAFE_ENTRY(void, Unsafe_FreeMemory(JNIEnv *env, jobject unsafe, jlong addr))
 660   UnsafeWrapper("Unsafe_FreeMemory");
 661   void* p = addr_from_java(addr);
 662   if (p == NULL) {
 663     return;
 664   }
 665   os::free(p);
 666 UNSAFE_END
 667 
 668 UNSAFE_ENTRY(void, Unsafe_SetMemory(JNIEnv *env, jobject unsafe, jlong addr, jlong size, jbyte value))
 669   UnsafeWrapper("Unsafe_SetMemory");
 670   size_t sz = (size_t)size;
 671   if (sz != (julong)size || size < 0) {
 672     THROW(vmSymbols::java_lang_IllegalArgumentException());
 673   }
 674   char* p = (char*) addr_from_java(addr);
 675   Copy::fill_to_memory_atomic(p, sz, value);
 676 UNSAFE_END
 677 
 678 UNSAFE_ENTRY(void, Unsafe_SetMemory2(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jlong size, jbyte value))
 679   UnsafeWrapper("Unsafe_SetMemory");
 680   size_t sz = (size_t)size;
 681   if (sz != (julong)size || size < 0) {
 682     THROW(vmSymbols::java_lang_IllegalArgumentException());
 683   }
 684   oop base = JNIHandles::resolve(obj);
 685   void* p = index_oop_from_field_offset_long(base, offset);
 686   Copy::fill_to_memory_atomic(p, sz, value);
 687 UNSAFE_END
 688 
 689 UNSAFE_ENTRY(void, Unsafe_CopyMemory(JNIEnv *env, jobject unsafe, jlong srcAddr, jlong dstAddr, jlong size))
 690   UnsafeWrapper("Unsafe_CopyMemory");
 691   if (size == 0) {
 692     return;
 693   }
 694   size_t sz = (size_t)size;
 695   if (sz != (julong)size || size < 0) {
 696     THROW(vmSymbols::java_lang_IllegalArgumentException());
 697   }
 698   void* src = addr_from_java(srcAddr);
 699   void* dst = addr_from_java(dstAddr);
 700   Copy::conjoint_memory_atomic(src, dst, sz);
 701 UNSAFE_END
 702 
 703 UNSAFE_ENTRY(void, Unsafe_CopyMemory2(JNIEnv *env, jobject unsafe, jobject srcObj, jlong srcOffset, jobject dstObj, jlong dstOffset, jlong size))
 704   UnsafeWrapper("Unsafe_CopyMemory");
 705   if (size == 0) {
 706     return;
 707   }
 708   size_t sz = (size_t)size;
 709   if (sz != (julong)size || size < 0) {
 710     THROW(vmSymbols::java_lang_IllegalArgumentException());
 711   }
 712   oop srcp = JNIHandles::resolve(srcObj);
 713   oop dstp = JNIHandles::resolve(dstObj);
 714   if (dstp != NULL && !dstp->is_typeArray()) {
 715     // NYI:  This works only for non-oop arrays at present.
 716     // Generalizing it would be reasonable, but requires card marking.
 717     // Also, autoboxing a Long from 0L in copyMemory(x,y, 0L,z, n) would be bad.
 718     THROW(vmSymbols::java_lang_IllegalArgumentException());
 719   }
 720   void* src = index_oop_from_field_offset_long(srcp, srcOffset);
 721   void* dst = index_oop_from_field_offset_long(dstp, dstOffset);
 722   Copy::conjoint_memory_atomic(src, dst, sz);
 723 UNSAFE_END
 724 
 725 
 726 ////// Random queries
 727 
 728 // See comment at file start about UNSAFE_LEAF
 729 //UNSAFE_LEAF(jint, Unsafe_AddressSize())
 730 UNSAFE_ENTRY(jint, Unsafe_AddressSize(JNIEnv *env, jobject unsafe))
 731   UnsafeWrapper("Unsafe_AddressSize");
 732   return sizeof(void*);
 733 UNSAFE_END
 734 
 735 // See comment at file start about UNSAFE_LEAF
 736 //UNSAFE_LEAF(jint, Unsafe_PageSize())
 737 UNSAFE_ENTRY(jint, Unsafe_PageSize(JNIEnv *env, jobject unsafe))
 738   UnsafeWrapper("Unsafe_PageSize");
 739   return os::vm_page_size();
 740 UNSAFE_END
 741 
 742 jint find_field_offset(jobject field, int must_be_static, TRAPS) {
 743   if (field == NULL) {
 744     THROW_0(vmSymbols::java_lang_NullPointerException());
 745   }
 746 
 747   oop reflected   = JNIHandles::resolve_non_null(field);
 748   oop mirror      = java_lang_reflect_Field::clazz(reflected);
 749   Klass* k      = java_lang_Class::as_Klass(mirror);
 750   int slot        = java_lang_reflect_Field::slot(reflected);
 751   int modifiers   = java_lang_reflect_Field::modifiers(reflected);
 752 
 753   if (must_be_static >= 0) {
 754     int really_is_static = ((modifiers & JVM_ACC_STATIC) != 0);
 755     if (must_be_static != really_is_static) {
 756       THROW_0(vmSymbols::java_lang_IllegalArgumentException());
 757     }
 758   }
 759 
 760   int offset = InstanceKlass::cast(k)->field_offset(slot);
 761   return field_offset_from_byte_offset(offset);
 762 }
 763 
 764 UNSAFE_ENTRY(jlong, Unsafe_ObjectFieldOffset(JNIEnv *env, jobject unsafe, jobject field))
 765   UnsafeWrapper("Unsafe_ObjectFieldOffset");
 766   return find_field_offset(field, 0, THREAD);
 767 UNSAFE_END
 768 
 769 UNSAFE_ENTRY(jlong, Unsafe_StaticFieldOffset(JNIEnv *env, jobject unsafe, jobject field))
 770   UnsafeWrapper("Unsafe_StaticFieldOffset");
 771   return find_field_offset(field, 1, THREAD);
 772 UNSAFE_END
 773 
 774 UNSAFE_ENTRY(jobject, Unsafe_StaticFieldBaseFromField(JNIEnv *env, jobject unsafe, jobject field))
 775   UnsafeWrapper("Unsafe_StaticFieldBase");
 776   // Note:  In this VM implementation, a field address is always a short
 777   // offset from the base of a a klass metaobject.  Thus, the full dynamic
 778   // range of the return type is never used.  However, some implementations
 779   // might put the static field inside an array shared by many classes,
 780   // or even at a fixed address, in which case the address could be quite
 781   // large.  In that last case, this function would return NULL, since
 782   // the address would operate alone, without any base pointer.
 783 
 784   if (field == NULL)  THROW_0(vmSymbols::java_lang_NullPointerException());
 785 
 786   oop reflected   = JNIHandles::resolve_non_null(field);
 787   oop mirror      = java_lang_reflect_Field::clazz(reflected);
 788   int modifiers   = java_lang_reflect_Field::modifiers(reflected);
 789 
 790   if ((modifiers & JVM_ACC_STATIC) == 0) {
 791     THROW_0(vmSymbols::java_lang_IllegalArgumentException());
 792   }
 793 
 794   return JNIHandles::make_local(env, mirror);
 795 UNSAFE_END
 796 
 797 //@deprecated
 798 UNSAFE_ENTRY(jint, Unsafe_FieldOffset(JNIEnv *env, jobject unsafe, jobject field))
 799   UnsafeWrapper("Unsafe_FieldOffset");
 800   // tries (but fails) to be polymorphic between static and non-static:
 801   jlong offset = find_field_offset(field, -1, THREAD);
 802   guarantee(offset == (jint)offset, "offset fits in 32 bits");
 803   return (jint)offset;
 804 UNSAFE_END
 805 
 806 //@deprecated
 807 UNSAFE_ENTRY(jobject, Unsafe_StaticFieldBaseFromClass(JNIEnv *env, jobject unsafe, jobject clazz))
 808   UnsafeWrapper("Unsafe_StaticFieldBase");
 809   if (clazz == NULL) {
 810     THROW_0(vmSymbols::java_lang_NullPointerException());
 811   }
 812   return JNIHandles::make_local(env, JNIHandles::resolve_non_null(clazz));
 813 UNSAFE_END
 814 
 815 UNSAFE_ENTRY(void, Unsafe_EnsureClassInitialized(JNIEnv *env, jobject unsafe, jobject clazz)) {
 816   UnsafeWrapper("Unsafe_EnsureClassInitialized");
 817   if (clazz == NULL) {
 818     THROW(vmSymbols::java_lang_NullPointerException());
 819   }
 820   oop mirror = JNIHandles::resolve_non_null(clazz);
 821 
 822   Klass* klass = java_lang_Class::as_Klass(mirror);
 823   if (klass != NULL && klass->should_be_initialized()) {
 824     InstanceKlass* k = InstanceKlass::cast(klass);
 825     k->initialize(CHECK);
 826   }
 827 }
 828 UNSAFE_END
 829 
 830 UNSAFE_ENTRY(jboolean, Unsafe_ShouldBeInitialized(JNIEnv *env, jobject unsafe, jobject clazz)) {
 831   UnsafeWrapper("Unsafe_ShouldBeInitialized");
 832   if (clazz == NULL) {
 833     THROW_(vmSymbols::java_lang_NullPointerException(), false);
 834   }
 835   oop mirror = JNIHandles::resolve_non_null(clazz);
 836   Klass* klass = java_lang_Class::as_Klass(mirror);
 837   if (klass != NULL && klass->should_be_initialized()) {
 838     return true;
 839   }
 840   return false;
 841 }
 842 UNSAFE_END
 843 
 844 static void getBaseAndScale(int& base, int& scale, jclass acls, TRAPS) {
 845   if (acls == NULL) {
 846     THROW(vmSymbols::java_lang_NullPointerException());
 847   }
 848   oop      mirror = JNIHandles::resolve_non_null(acls);
 849   Klass* k      = java_lang_Class::as_Klass(mirror);
 850   if (k == NULL || !k->oop_is_array()) {
 851     THROW(vmSymbols::java_lang_InvalidClassException());
 852   } else if (k->oop_is_objArray()) {
 853     base  = arrayOopDesc::base_offset_in_bytes(T_OBJECT);
 854     scale = heapOopSize;
 855   } else if (k->oop_is_typeArray()) {
 856     TypeArrayKlass* tak = TypeArrayKlass::cast(k);
 857     base  = tak->array_header_in_bytes();
 858     assert(base == arrayOopDesc::base_offset_in_bytes(tak->element_type()), "array_header_size semantics ok");
 859     scale = (1 << tak->log2_element_size());
 860   } else {
 861     ShouldNotReachHere();
 862   }
 863 }
 864 
 865 UNSAFE_ENTRY(jint, Unsafe_ArrayBaseOffset(JNIEnv *env, jobject unsafe, jclass acls))
 866   UnsafeWrapper("Unsafe_ArrayBaseOffset");
 867   int base = 0, scale = 0;
 868   getBaseAndScale(base, scale, acls, CHECK_0);
 869   return field_offset_from_byte_offset(base);
 870 UNSAFE_END
 871 
 872 
 873 UNSAFE_ENTRY(jint, Unsafe_ArrayIndexScale(JNIEnv *env, jobject unsafe, jclass acls))
 874   UnsafeWrapper("Unsafe_ArrayIndexScale");
 875   int base = 0, scale = 0;
 876   getBaseAndScale(base, scale, acls, CHECK_0);
 877   // This VM packs both fields and array elements down to the byte.
 878   // But watch out:  If this changes, so that array references for
 879   // a given primitive type (say, T_BOOLEAN) use different memory units
 880   // than fields, this method MUST return zero for such arrays.
 881   // For example, the VM used to store sub-word sized fields in full
 882   // words in the object layout, so that accessors like getByte(Object,int)
 883   // did not really do what one might expect for arrays.  Therefore,
 884   // this function used to report a zero scale factor, so that the user
 885   // would know not to attempt to access sub-word array elements.
 886   // // Code for unpacked fields:
 887   // if (scale < wordSize)  return 0;
 888 
 889   // The following allows for a pretty general fieldOffset cookie scheme,
 890   // but requires it to be linear in byte offset.
 891   return field_offset_from_byte_offset(scale) - field_offset_from_byte_offset(0);
 892 UNSAFE_END
 893 
 894 
 895 static inline void throw_new(JNIEnv *env, const char *ename) {
 896   char buf[100];
 897   strcpy(buf, "java/lang/");
 898   strcat(buf, ename);
 899   jclass cls = env->FindClass(buf);
 900   if (env->ExceptionCheck()) {
 901     env->ExceptionClear();
 902     tty->print_cr("Unsafe: cannot throw %s because FindClass has failed", buf);
 903     return;
 904   }
 905   char* msg = NULL;
 906   env->ThrowNew(cls, msg);
 907 }
 908 
 909 static jclass Unsafe_DefineClass_impl(JNIEnv *env, jstring name, jbyteArray data, int offset, int length, jobject loader, jobject pd) {
 910   {
 911     // Code lifted from JDK 1.3 ClassLoader.c
 912 
 913     jbyte *body;
 914     char *utfName;
 915     jclass result = 0;
 916     char buf[128];
 917 
 918     if (UsePerfData) {
 919       ClassLoader::unsafe_defineClassCallCounter()->inc();
 920     }
 921 
 922     if (data == NULL) {
 923         throw_new(env, "NullPointerException");
 924         return 0;
 925     }
 926 
 927     /* Work around 4153825. malloc crashes on Solaris when passed a
 928      * negative size.
 929      */
 930     if (length < 0) {
 931         throw_new(env, "ArrayIndexOutOfBoundsException");
 932         return 0;
 933     }
 934 
 935     body = NEW_C_HEAP_ARRAY(jbyte, length, mtInternal);
 936 
 937     if (body == 0) {
 938         throw_new(env, "OutOfMemoryError");
 939         return 0;
 940     }
 941 
 942     env->GetByteArrayRegion(data, offset, length, body);
 943 
 944     if (env->ExceptionOccurred())
 945         goto free_body;
 946 
 947     if (name != NULL) {
 948         uint len = env->GetStringUTFLength(name);
 949         int unicode_len = env->GetStringLength(name);
 950         if (len >= sizeof(buf)) {
 951             utfName = NEW_C_HEAP_ARRAY(char, len + 1, mtInternal);
 952             if (utfName == NULL) {
 953                 throw_new(env, "OutOfMemoryError");
 954                 goto free_body;
 955             }
 956         } else {
 957             utfName = buf;
 958         }
 959         env->GetStringUTFRegion(name, 0, unicode_len, utfName);
 960         //VerifyFixClassname(utfName);
 961         for (uint i = 0; i < len; i++) {
 962           if (utfName[i] == '.')   utfName[i] = '/';
 963         }
 964     } else {
 965         utfName = NULL;
 966     }
 967 
 968     result = JVM_DefineClass(env, utfName, loader, body, length, pd);
 969 
 970     if (utfName && utfName != buf)
 971         FREE_C_HEAP_ARRAY(char, utfName, mtInternal);
 972 
 973  free_body:
 974     FREE_C_HEAP_ARRAY(jbyte, body, mtInternal);
 975     return result;
 976   }
 977 }
 978 
 979 
 980 UNSAFE_ENTRY(jclass, Unsafe_DefineClass(JNIEnv *env, jobject unsafe, jstring name, jbyteArray data, int offset, int length, jobject loader, jobject pd))
 981   UnsafeWrapper("Unsafe_DefineClass");
 982   {
 983     ThreadToNativeFromVM ttnfv(thread);
 984     return Unsafe_DefineClass_impl(env, name, data, offset, length, loader, pd);
 985   }
 986 UNSAFE_END
 987 
 988 
 989 UNSAFE_ENTRY(jclass, Unsafe_DefineClass0(JNIEnv *env, jobject unsafe, jstring name, jbyteArray data, int offset, int length))
 990   UnsafeWrapper("Unsafe_DefineClass");
 991   {
 992     ThreadToNativeFromVM ttnfv(thread);
 993 
 994     int depthFromDefineClass0 = 1;
 995     jclass  caller = JVM_GetCallerClass(env, depthFromDefineClass0);
 996     jobject loader = (caller == NULL) ? NULL : JVM_GetClassLoader(env, caller);
 997     jobject pd     = (caller == NULL) ? NULL : JVM_GetProtectionDomain(env, caller);
 998 
 999     return Unsafe_DefineClass_impl(env, name, data, offset, length, loader, pd);
1000   }
1001 UNSAFE_END
1002 
1003 
1004 #define DAC_Args CLS"[B["OBJ
1005 // define a class but do not make it known to the class loader or system dictionary
1006 // - host_class:  supplies context for linkage, access control, protection domain, and class loader
1007 // - data:  bytes of a class file, a raw memory address (length gives the number of bytes)
1008 // - cp_patches:  where non-null entries exist, they replace corresponding CP entries in data
1009 
1010 // When you load an anonymous class U, it works as if you changed its name just before loading,
1011 // to a name that you will never use again.  Since the name is lost, no other class can directly
1012 // link to any member of U.  Just after U is loaded, the only way to use it is reflectively,
1013 // through java.lang.Class methods like Class.newInstance.
1014 
1015 // Access checks for linkage sites within U continue to follow the same rules as for named classes.
1016 // The package of an anonymous class is given by the package qualifier on the name under which it was loaded.
1017 // An anonymous class also has special privileges to access any member of its host class.
1018 // This is the main reason why this loading operation is unsafe.  The purpose of this is to
1019 // allow language implementations to simulate "open classes"; a host class in effect gets
1020 // new code when an anonymous class is loaded alongside it.  A less convenient but more
1021 // standard way to do this is with reflection, which can also be set to ignore access
1022 // restrictions.
1023 
1024 // Access into an anonymous class is possible only through reflection.  Therefore, there
1025 // are no special access rules for calling into an anonymous class.  The relaxed access
1026 // rule for the host class is applied in the opposite direction:  A host class reflectively
1027 // access one of its anonymous classes.
1028 
1029 // If you load the same bytecodes twice, you get two different classes.  You can reload
1030 // the same bytecodes with or without varying CP patches.
1031 
1032 // By using the CP patching array, you can have a new anonymous class U2 refer to an older one U1.
1033 // The bytecodes for U2 should refer to U1 by a symbolic name (doesn't matter what the name is).
1034 // The CONSTANT_Class entry for that name can be patched to refer directly to U1.
1035 
1036 // This allows, for example, U2 to use U1 as a superclass or super-interface, or as
1037 // an outer class (so that U2 is an anonymous inner class of anonymous U1).
1038 // It is not possible for a named class, or an older anonymous class, to refer by
1039 // name (via its CP) to a newer anonymous class.
1040 
1041 // CP patching may also be used to modify (i.e., hack) the names of methods, classes,
1042 // or type descriptors used in the loaded anonymous class.
1043 
1044 // Finally, CP patching may be used to introduce "live" objects into the constant pool,
1045 // instead of "dead" strings.  A compiled statement like println((Object)"hello") can
1046 // be changed to println(greeting), where greeting is an arbitrary object created before
1047 // the anonymous class is loaded.  This is useful in dynamic languages, in which
1048 // various kinds of metaobjects must be introduced as constants into bytecode.
1049 // Note the cast (Object), which tells the verifier to expect an arbitrary object,
1050 // not just a literal string.  For such ldc instructions, the verifier uses the
1051 // type Object instead of String, if the loaded constant is not in fact a String.
1052 
1053 static instanceKlassHandle
1054 Unsafe_DefineAnonymousClass_impl(JNIEnv *env,
1055                                  jclass host_class, jbyteArray data, jobjectArray cp_patches_jh,
1056                                  HeapWord* *temp_alloc,
1057                                  TRAPS) {
1058 
1059   if (UsePerfData) {
1060     ClassLoader::unsafe_defineClassCallCounter()->inc();
1061   }
1062 
1063   if (data == NULL) {
1064     THROW_0(vmSymbols::java_lang_NullPointerException());
1065   }
1066 
1067   jint length = typeArrayOop(JNIHandles::resolve_non_null(data))->length();
1068   jint word_length = (length + sizeof(HeapWord)-1) / sizeof(HeapWord);
1069   HeapWord* body = NEW_C_HEAP_ARRAY(HeapWord, word_length, mtInternal);
1070   if (body == NULL) {
1071     THROW_0(vmSymbols::java_lang_OutOfMemoryError());
1072   }
1073 
1074   // caller responsible to free it:
1075   (*temp_alloc) = body;
1076 
1077   {
1078     jbyte* array_base = typeArrayOop(JNIHandles::resolve_non_null(data))->byte_at_addr(0);
1079     Copy::conjoint_words((HeapWord*) array_base, body, word_length);
1080   }
1081 
1082   u1* class_bytes = (u1*) body;
1083   int class_bytes_length = (int) length;
1084   if (class_bytes_length < 0)  class_bytes_length = 0;
1085   if (class_bytes == NULL
1086       || host_class == NULL
1087       || length != class_bytes_length)
1088     THROW_0(vmSymbols::java_lang_IllegalArgumentException());
1089 
1090   objArrayHandle cp_patches_h;
1091   if (cp_patches_jh != NULL) {
1092     oop p = JNIHandles::resolve_non_null(cp_patches_jh);
1093     if (!p->is_objArray())
1094       THROW_0(vmSymbols::java_lang_IllegalArgumentException());
1095     cp_patches_h = objArrayHandle(THREAD, (objArrayOop)p);
1096   }
1097 
1098   KlassHandle host_klass(THREAD, java_lang_Class::as_Klass(JNIHandles::resolve_non_null(host_class)));
1099   const char* host_source = host_klass->external_name();
1100   Handle      host_loader(THREAD, host_klass->class_loader());
1101   Handle      host_domain(THREAD, host_klass->protection_domain());
1102 
1103   GrowableArray<Handle>* cp_patches = NULL;
1104   if (cp_patches_h.not_null()) {
1105     int alen = cp_patches_h->length();
1106     for (int i = alen-1; i >= 0; i--) {
1107       oop p = cp_patches_h->obj_at(i);
1108       if (p != NULL) {
1109         Handle patch(THREAD, p);
1110         if (cp_patches == NULL)
1111           cp_patches = new GrowableArray<Handle>(i+1, i+1, Handle());
1112         cp_patches->at_put(i, patch);
1113       }
1114     }
1115   }
1116 
1117   ClassFileStream st(class_bytes, class_bytes_length, (char*) host_source);
1118 
1119   instanceKlassHandle anon_klass;
1120   {
1121     Symbol* no_class_name = NULL;
1122     Klass* anonk = SystemDictionary::parse_stream(no_class_name,
1123                                                     host_loader, host_domain,
1124                                                     &st, host_klass, cp_patches,
1125                                                     CHECK_NULL);
1126     if (anonk == NULL)  return NULL;
1127     anon_klass = instanceKlassHandle(THREAD, anonk);
1128   }
1129 
1130   return anon_klass;
1131 }
1132 
1133 UNSAFE_ENTRY(jclass, Unsafe_DefineAnonymousClass(JNIEnv *env, jobject unsafe, jclass host_class, jbyteArray data, jobjectArray cp_patches_jh))
1134 {
1135   instanceKlassHandle anon_klass;
1136   jobject res_jh = NULL;
1137 
1138   UnsafeWrapper("Unsafe_DefineAnonymousClass");
1139   ResourceMark rm(THREAD);
1140 
1141   HeapWord* temp_alloc = NULL;
1142 
1143   anon_klass = Unsafe_DefineAnonymousClass_impl(env, host_class, data,
1144                                                 cp_patches_jh,
1145                                                    &temp_alloc, THREAD);
1146   if (anon_klass() != NULL)
1147     res_jh = JNIHandles::make_local(env, anon_klass->java_mirror());
1148 
1149   // try/finally clause:
1150   if (temp_alloc != NULL) {
1151     FREE_C_HEAP_ARRAY(HeapWord, temp_alloc, mtInternal);
1152   }
1153 
1154   // The anonymous class loader data has been artificially been kept alive to
1155   // this point.   The mirror and any instances of this class have to keep
1156   // it alive afterwards.
1157   if (anon_klass() != NULL) {
1158     anon_klass->class_loader_data()->set_keep_alive(false);
1159   }
1160 
1161   // let caller initialize it as needed...
1162 
1163   return (jclass) res_jh;
1164 }
1165 UNSAFE_END
1166 
1167 
1168 
1169 UNSAFE_ENTRY(void, Unsafe_MonitorEnter(JNIEnv *env, jobject unsafe, jobject jobj))
1170   UnsafeWrapper("Unsafe_MonitorEnter");
1171   {
1172     if (jobj == NULL) {
1173       THROW(vmSymbols::java_lang_NullPointerException());
1174     }
1175     Handle obj(thread, JNIHandles::resolve_non_null(jobj));
1176     ObjectSynchronizer::jni_enter(obj, CHECK);
1177   }
1178 UNSAFE_END
1179 
1180 
1181 UNSAFE_ENTRY(jboolean, Unsafe_TryMonitorEnter(JNIEnv *env, jobject unsafe, jobject jobj))
1182   UnsafeWrapper("Unsafe_TryMonitorEnter");
1183   {
1184     if (jobj == NULL) {
1185       THROW_(vmSymbols::java_lang_NullPointerException(), JNI_FALSE);
1186     }
1187     Handle obj(thread, JNIHandles::resolve_non_null(jobj));
1188     bool res = ObjectSynchronizer::jni_try_enter(obj, CHECK_0);
1189     return (res ? JNI_TRUE : JNI_FALSE);
1190   }
1191 UNSAFE_END
1192 
1193 
1194 UNSAFE_ENTRY(void, Unsafe_MonitorExit(JNIEnv *env, jobject unsafe, jobject jobj))
1195   UnsafeWrapper("Unsafe_MonitorExit");
1196   {
1197     if (jobj == NULL) {
1198       THROW(vmSymbols::java_lang_NullPointerException());
1199     }
1200     Handle obj(THREAD, JNIHandles::resolve_non_null(jobj));
1201     ObjectSynchronizer::jni_exit(obj(), CHECK);
1202   }
1203 UNSAFE_END
1204 
1205 
1206 UNSAFE_ENTRY(void, Unsafe_ThrowException(JNIEnv *env, jobject unsafe, jthrowable thr))
1207   UnsafeWrapper("Unsafe_ThrowException");
1208   {
1209     ThreadToNativeFromVM ttnfv(thread);
1210     env->Throw(thr);
1211   }
1212 UNSAFE_END
1213 
1214 // JSR166 ------------------------------------------------------------------
1215 
1216 UNSAFE_ENTRY(jboolean, Unsafe_CompareAndSwapObject(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jobject e_h, jobject x_h))
1217   UnsafeWrapper("Unsafe_CompareAndSwapObject");
1218   oop x = JNIHandles::resolve(x_h);
1219   oop e = JNIHandles::resolve(e_h);
1220   oop p = JNIHandles::resolve(obj);
1221   HeapWord* addr = (HeapWord *)index_oop_from_field_offset_long(p, offset);
1222   oop res = oopDesc::atomic_compare_exchange_oop(x, addr, e, true);
1223   jboolean success  = (res == e);
1224   if (success)
1225     update_barrier_set((void*)addr, x);
1226   return success;
1227 UNSAFE_END
1228 
1229 UNSAFE_ENTRY(jboolean, Unsafe_CompareAndSwapInt(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jint e, jint x))
1230   UnsafeWrapper("Unsafe_CompareAndSwapInt");
1231   oop p = JNIHandles::resolve(obj);
1232   jint* addr = (jint *) index_oop_from_field_offset_long(p, offset);
1233   return (jint)(Atomic::cmpxchg(x, addr, e)) == e;
1234 UNSAFE_END
1235 
1236 UNSAFE_ENTRY(jboolean, Unsafe_CompareAndSwapLong(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jlong e, jlong x))
1237   UnsafeWrapper("Unsafe_CompareAndSwapLong");
1238   Handle p (THREAD, JNIHandles::resolve(obj));
1239   jlong* addr = (jlong*)(index_oop_from_field_offset_long(p(), offset));
1240 #ifdef SUPPORTS_NATIVE_CX8
1241   return (jlong)(Atomic::cmpxchg(x, addr, e)) == e;
1242 #else
1243   if (VM_Version::supports_cx8())
1244     return (jlong)(Atomic::cmpxchg(x, addr, e)) == e;
1245   else {
1246     jboolean success = false;
1247     MutexLockerEx mu(UnsafeJlong_lock, Mutex::_no_safepoint_check_flag);
1248     jlong val = Atomic::load(addr);
1249     if (val == e) { Atomic::store(x, addr); success = true; }
1250     return success;
1251   }
1252 #endif
1253 UNSAFE_END
1254 
1255 UNSAFE_ENTRY(void, Unsafe_Park(JNIEnv *env, jobject unsafe, jboolean isAbsolute, jlong time))
1256   UnsafeWrapper("Unsafe_Park");
1257   EventThreadPark event;
1258 #ifndef USDT2
1259   HS_DTRACE_PROBE3(hotspot, thread__park__begin, thread->parker(), (int) isAbsolute, time);
1260 #else /* USDT2 */
1261    HOTSPOT_THREAD_PARK_BEGIN(
1262                              (uintptr_t) thread->parker(), (int) isAbsolute, time);
1263 #endif /* USDT2 */
1264   JavaThreadParkedState jtps(thread, time != 0);
1265   thread->parker()->park(isAbsolute != 0, time);
1266 #ifndef USDT2
1267   HS_DTRACE_PROBE1(hotspot, thread__park__end, thread->parker());
1268 #else /* USDT2 */
1269   HOTSPOT_THREAD_PARK_END(
1270                           (uintptr_t) thread->parker());
1271 #endif /* USDT2 */
1272   if (event.should_commit()) {
1273     oop obj = thread->current_park_blocker();
1274     event.set_klass((obj != NULL) ? obj->klass() : NULL);
1275     event.set_timeout(time);
1276     event.set_address((obj != NULL) ? (TYPE_ADDRESS) cast_from_oop<uintptr_t>(obj) : 0);
1277     event.commit();
1278   }
1279 UNSAFE_END
1280 
1281 UNSAFE_ENTRY(void, Unsafe_Unpark(JNIEnv *env, jobject unsafe, jobject jthread))
1282   UnsafeWrapper("Unsafe_Unpark");
1283   Parker* p = NULL;
1284   if (jthread != NULL) {
1285     oop java_thread = JNIHandles::resolve_non_null(jthread);
1286     if (java_thread != NULL) {
1287       jlong lp = java_lang_Thread::park_event(java_thread);
1288       if (lp != 0) {
1289         // This cast is OK even though the jlong might have been read
1290         // non-atomically on 32bit systems, since there, one word will
1291         // always be zero anyway and the value set is always the same
1292         p = (Parker*)addr_from_java(lp);
1293       } else {
1294         // Grab lock if apparently null or using older version of library
1295         MutexLocker mu(Threads_lock);
1296         java_thread = JNIHandles::resolve_non_null(jthread);
1297         if (java_thread != NULL) {
1298           JavaThread* thr = java_lang_Thread::thread(java_thread);
1299           if (thr != NULL) {
1300             p = thr->parker();
1301             if (p != NULL) { // Bind to Java thread for next time.
1302               java_lang_Thread::set_park_event(java_thread, addr_to_java(p));
1303             }
1304           }
1305         }
1306       }
1307     }
1308   }
1309   if (p != NULL) {
1310 #ifndef USDT2
1311     HS_DTRACE_PROBE1(hotspot, thread__unpark, p);
1312 #else /* USDT2 */
1313     HOTSPOT_THREAD_UNPARK(
1314                           (uintptr_t) p);
1315 #endif /* USDT2 */
1316     p->unpark();
1317   }
1318 UNSAFE_END
1319 
1320 UNSAFE_ENTRY(jint, Unsafe_Loadavg(JNIEnv *env, jobject unsafe, jdoubleArray loadavg, jint nelem))
1321   UnsafeWrapper("Unsafe_Loadavg");
1322   const int max_nelem = 3;
1323   double la[max_nelem];
1324   jint ret;
1325 
1326   typeArrayOop a = typeArrayOop(JNIHandles::resolve_non_null(loadavg));
1327   assert(a->is_typeArray(), "must be type array");
1328 
1329   if (nelem < 0 || nelem > max_nelem || a->length() < nelem) {
1330     ThreadToNativeFromVM ttnfv(thread);
1331     throw_new(env, "ArrayIndexOutOfBoundsException");
1332     return -1;
1333   }
1334 
1335   ret = os::loadavg(la, nelem);
1336   if (ret == -1) return -1;
1337 
1338   // if successful, ret is the number of samples actually retrieved.
1339   assert(ret >= 0 && ret <= max_nelem, "Unexpected loadavg return value");
1340   switch(ret) {
1341     case 3: a->double_at_put(2, (jdouble)la[2]); // fall through
1342     case 2: a->double_at_put(1, (jdouble)la[1]); // fall through
1343     case 1: a->double_at_put(0, (jdouble)la[0]); break;
1344   }
1345   return ret;
1346 UNSAFE_END
1347 
1348 UNSAFE_ENTRY(void, Unsafe_PrefetchRead(JNIEnv* env, jclass ignored, jobject obj, jlong offset))
1349   UnsafeWrapper("Unsafe_PrefetchRead");
1350   oop p = JNIHandles::resolve(obj);
1351   void* addr = index_oop_from_field_offset_long(p, 0);
1352   Prefetch::read(addr, (intx)offset);
1353 UNSAFE_END
1354 
1355 UNSAFE_ENTRY(void, Unsafe_PrefetchWrite(JNIEnv* env, jclass ignored, jobject obj, jlong offset))
1356   UnsafeWrapper("Unsafe_PrefetchWrite");
1357   oop p = JNIHandles::resolve(obj);
1358   void* addr = index_oop_from_field_offset_long(p, 0);
1359   Prefetch::write(addr, (intx)offset);
1360 UNSAFE_END
1361 
1362 
1363 /// JVM_RegisterUnsafeMethods
1364 
1365 #define ADR "J"
1366 
1367 #define LANG "Ljava/lang/"
1368 
1369 #define OBJ LANG"Object;"
1370 #define CLS LANG"Class;"
1371 #define CTR LANG"reflect/Constructor;"
1372 #define FLD LANG"reflect/Field;"
1373 #define MTH LANG"reflect/Method;"
1374 #define THR LANG"Throwable;"
1375 
1376 #define DC0_Args LANG"String;[BII"
1377 #define DC_Args  DC0_Args LANG"ClassLoader;" "Ljava/security/ProtectionDomain;"
1378 
1379 #define CC (char*)  /*cast a literal from (const char*)*/
1380 #define FN_PTR(f) CAST_FROM_FN_PTR(void*, &f)
1381 
1382 // define deprecated accessors for compabitility with 1.4.0
1383 #define DECLARE_GETSETOOP_140(Boolean, Z) \
1384     {CC"get"#Boolean,      CC"("OBJ"I)"#Z,      FN_PTR(Unsafe_Get##Boolean##140)}, \
1385     {CC"put"#Boolean,      CC"("OBJ"I"#Z")V",   FN_PTR(Unsafe_Set##Boolean##140)}
1386 
1387 // Note:  In 1.4.1, getObject and kin take both int and long offsets.
1388 #define DECLARE_GETSETOOP_141(Boolean, Z) \
1389     {CC"get"#Boolean,      CC"("OBJ"J)"#Z,      FN_PTR(Unsafe_Get##Boolean)}, \
1390     {CC"put"#Boolean,      CC"("OBJ"J"#Z")V",   FN_PTR(Unsafe_Set##Boolean)}
1391 
1392 // Note:  In 1.5.0, there are volatile versions too
1393 #define DECLARE_GETSETOOP(Boolean, Z) \
1394     {CC"get"#Boolean,      CC"("OBJ"J)"#Z,      FN_PTR(Unsafe_Get##Boolean)}, \
1395     {CC"put"#Boolean,      CC"("OBJ"J"#Z")V",   FN_PTR(Unsafe_Set##Boolean)}, \
1396     {CC"get"#Boolean"Volatile",      CC"("OBJ"J)"#Z,      FN_PTR(Unsafe_Get##Boolean##Volatile)}, \
1397     {CC"put"#Boolean"Volatile",      CC"("OBJ"J"#Z")V",   FN_PTR(Unsafe_Set##Boolean##Volatile)}
1398 
1399 
1400 #define DECLARE_GETSETNATIVE(Byte, B) \
1401     {CC"get"#Byte,         CC"("ADR")"#B,       FN_PTR(Unsafe_GetNative##Byte)}, \
1402     {CC"put"#Byte,         CC"("ADR#B")V",      FN_PTR(Unsafe_SetNative##Byte)}
1403 
1404 
1405 
1406 // These are the methods for 1.4.0
1407 static JNINativeMethod methods_140[] = {
1408     {CC"getObject",        CC"("OBJ"I)"OBJ"",   FN_PTR(Unsafe_GetObject140)},
1409     {CC"putObject",        CC"("OBJ"I"OBJ")V",  FN_PTR(Unsafe_SetObject140)},
1410 
1411     DECLARE_GETSETOOP_140(Boolean, Z),
1412     DECLARE_GETSETOOP_140(Byte, B),
1413     DECLARE_GETSETOOP_140(Short, S),
1414     DECLARE_GETSETOOP_140(Char, C),
1415     DECLARE_GETSETOOP_140(Int, I),
1416     DECLARE_GETSETOOP_140(Long, J),
1417     DECLARE_GETSETOOP_140(Float, F),
1418     DECLARE_GETSETOOP_140(Double, D),
1419 
1420     DECLARE_GETSETNATIVE(Byte, B),
1421     DECLARE_GETSETNATIVE(Short, S),
1422     DECLARE_GETSETNATIVE(Char, C),
1423     DECLARE_GETSETNATIVE(Int, I),
1424     DECLARE_GETSETNATIVE(Long, J),
1425     DECLARE_GETSETNATIVE(Float, F),
1426     DECLARE_GETSETNATIVE(Double, D),
1427 
1428     {CC"getAddress",         CC"("ADR")"ADR,             FN_PTR(Unsafe_GetNativeAddress)},
1429     {CC"putAddress",         CC"("ADR""ADR")V",          FN_PTR(Unsafe_SetNativeAddress)},
1430 
1431     {CC"allocateMemory",     CC"(J)"ADR,                 FN_PTR(Unsafe_AllocateMemory)},
1432     {CC"reallocateMemory",   CC"("ADR"J)"ADR,            FN_PTR(Unsafe_ReallocateMemory)},
1433     {CC"freeMemory",         CC"("ADR")V",               FN_PTR(Unsafe_FreeMemory)},
1434 
1435     {CC"fieldOffset",        CC"("FLD")I",               FN_PTR(Unsafe_FieldOffset)},
1436     {CC"staticFieldBase",    CC"("CLS")"OBJ,             FN_PTR(Unsafe_StaticFieldBaseFromClass)},
1437     {CC"ensureClassInitialized",CC"("CLS")V",            FN_PTR(Unsafe_EnsureClassInitialized)},
1438     {CC"arrayBaseOffset",    CC"("CLS")I",               FN_PTR(Unsafe_ArrayBaseOffset)},
1439     {CC"arrayIndexScale",    CC"("CLS")I",               FN_PTR(Unsafe_ArrayIndexScale)},
1440     {CC"addressSize",        CC"()I",                    FN_PTR(Unsafe_AddressSize)},
1441     {CC"pageSize",           CC"()I",                    FN_PTR(Unsafe_PageSize)},
1442 
1443     {CC"defineClass",        CC"("DC0_Args")"CLS,        FN_PTR(Unsafe_DefineClass0)},
1444     {CC"defineClass",        CC"("DC_Args")"CLS,         FN_PTR(Unsafe_DefineClass)},
1445     {CC"allocateInstance",   CC"("CLS")"OBJ,             FN_PTR(Unsafe_AllocateInstance)},
1446     {CC"monitorEnter",       CC"("OBJ")V",               FN_PTR(Unsafe_MonitorEnter)},
1447     {CC"monitorExit",        CC"("OBJ")V",               FN_PTR(Unsafe_MonitorExit)},
1448     {CC"throwException",     CC"("THR")V",               FN_PTR(Unsafe_ThrowException)}
1449 };
1450 
1451 // These are the methods prior to the JSR 166 changes in 1.5.0
1452 static JNINativeMethod methods_141[] = {
1453     {CC"getObject",        CC"("OBJ"J)"OBJ"",   FN_PTR(Unsafe_GetObject)},
1454     {CC"putObject",        CC"("OBJ"J"OBJ")V",  FN_PTR(Unsafe_SetObject)},
1455 
1456     DECLARE_GETSETOOP_141(Boolean, Z),
1457     DECLARE_GETSETOOP_141(Byte, B),
1458     DECLARE_GETSETOOP_141(Short, S),
1459     DECLARE_GETSETOOP_141(Char, C),
1460     DECLARE_GETSETOOP_141(Int, I),
1461     DECLARE_GETSETOOP_141(Long, J),
1462     DECLARE_GETSETOOP_141(Float, F),
1463     DECLARE_GETSETOOP_141(Double, D),
1464 
1465     DECLARE_GETSETNATIVE(Byte, B),
1466     DECLARE_GETSETNATIVE(Short, S),
1467     DECLARE_GETSETNATIVE(Char, C),
1468     DECLARE_GETSETNATIVE(Int, I),
1469     DECLARE_GETSETNATIVE(Long, J),
1470     DECLARE_GETSETNATIVE(Float, F),
1471     DECLARE_GETSETNATIVE(Double, D),
1472 
1473     {CC"getAddress",         CC"("ADR")"ADR,             FN_PTR(Unsafe_GetNativeAddress)},
1474     {CC"putAddress",         CC"("ADR""ADR")V",          FN_PTR(Unsafe_SetNativeAddress)},
1475 
1476     {CC"allocateMemory",     CC"(J)"ADR,                 FN_PTR(Unsafe_AllocateMemory)},
1477     {CC"reallocateMemory",   CC"("ADR"J)"ADR,            FN_PTR(Unsafe_ReallocateMemory)},
1478     {CC"freeMemory",         CC"("ADR")V",               FN_PTR(Unsafe_FreeMemory)},
1479 
1480     {CC"objectFieldOffset",  CC"("FLD")J",               FN_PTR(Unsafe_ObjectFieldOffset)},
1481     {CC"staticFieldOffset",  CC"("FLD")J",               FN_PTR(Unsafe_StaticFieldOffset)},
1482     {CC"staticFieldBase",    CC"("FLD")"OBJ,             FN_PTR(Unsafe_StaticFieldBaseFromField)},
1483     {CC"ensureClassInitialized",CC"("CLS")V",            FN_PTR(Unsafe_EnsureClassInitialized)},
1484     {CC"arrayBaseOffset",    CC"("CLS")I",               FN_PTR(Unsafe_ArrayBaseOffset)},
1485     {CC"arrayIndexScale",    CC"("CLS")I",               FN_PTR(Unsafe_ArrayIndexScale)},
1486     {CC"addressSize",        CC"()I",                    FN_PTR(Unsafe_AddressSize)},
1487     {CC"pageSize",           CC"()I",                    FN_PTR(Unsafe_PageSize)},
1488 
1489     {CC"defineClass",        CC"("DC0_Args")"CLS,        FN_PTR(Unsafe_DefineClass0)},
1490     {CC"defineClass",        CC"("DC_Args")"CLS,         FN_PTR(Unsafe_DefineClass)},
1491     {CC"allocateInstance",   CC"("CLS")"OBJ,             FN_PTR(Unsafe_AllocateInstance)},
1492     {CC"monitorEnter",       CC"("OBJ")V",               FN_PTR(Unsafe_MonitorEnter)},
1493     {CC"monitorExit",        CC"("OBJ")V",               FN_PTR(Unsafe_MonitorExit)},
1494     {CC"throwException",     CC"("THR")V",               FN_PTR(Unsafe_ThrowException)}
1495 
1496 };
1497 
1498 // These are the methods prior to the JSR 166 changes in 1.6.0
1499 static JNINativeMethod methods_15[] = {
1500     {CC"getObject",        CC"("OBJ"J)"OBJ"",   FN_PTR(Unsafe_GetObject)},
1501     {CC"putObject",        CC"("OBJ"J"OBJ")V",  FN_PTR(Unsafe_SetObject)},
1502     {CC"getObjectVolatile",CC"("OBJ"J)"OBJ"",   FN_PTR(Unsafe_GetObjectVolatile)},
1503     {CC"putObjectVolatile",CC"("OBJ"J"OBJ")V",  FN_PTR(Unsafe_SetObjectVolatile)},
1504 
1505 
1506     DECLARE_GETSETOOP(Boolean, Z),
1507     DECLARE_GETSETOOP(Byte, B),
1508     DECLARE_GETSETOOP(Short, S),
1509     DECLARE_GETSETOOP(Char, C),
1510     DECLARE_GETSETOOP(Int, I),
1511     DECLARE_GETSETOOP(Long, J),
1512     DECLARE_GETSETOOP(Float, F),
1513     DECLARE_GETSETOOP(Double, D),
1514 
1515     DECLARE_GETSETNATIVE(Byte, B),
1516     DECLARE_GETSETNATIVE(Short, S),
1517     DECLARE_GETSETNATIVE(Char, C),
1518     DECLARE_GETSETNATIVE(Int, I),
1519     DECLARE_GETSETNATIVE(Long, J),
1520     DECLARE_GETSETNATIVE(Float, F),
1521     DECLARE_GETSETNATIVE(Double, D),
1522 
1523     {CC"getAddress",         CC"("ADR")"ADR,             FN_PTR(Unsafe_GetNativeAddress)},
1524     {CC"putAddress",         CC"("ADR""ADR")V",          FN_PTR(Unsafe_SetNativeAddress)},
1525 
1526     {CC"allocateMemory",     CC"(J)"ADR,                 FN_PTR(Unsafe_AllocateMemory)},
1527     {CC"reallocateMemory",   CC"("ADR"J)"ADR,            FN_PTR(Unsafe_ReallocateMemory)},
1528     {CC"freeMemory",         CC"("ADR")V",               FN_PTR(Unsafe_FreeMemory)},
1529 
1530     {CC"objectFieldOffset",  CC"("FLD")J",               FN_PTR(Unsafe_ObjectFieldOffset)},
1531     {CC"staticFieldOffset",  CC"("FLD")J",               FN_PTR(Unsafe_StaticFieldOffset)},
1532     {CC"staticFieldBase",    CC"("FLD")"OBJ,             FN_PTR(Unsafe_StaticFieldBaseFromField)},
1533     {CC"ensureClassInitialized",CC"("CLS")V",            FN_PTR(Unsafe_EnsureClassInitialized)},
1534     {CC"arrayBaseOffset",    CC"("CLS")I",               FN_PTR(Unsafe_ArrayBaseOffset)},
1535     {CC"arrayIndexScale",    CC"("CLS")I",               FN_PTR(Unsafe_ArrayIndexScale)},
1536     {CC"addressSize",        CC"()I",                    FN_PTR(Unsafe_AddressSize)},
1537     {CC"pageSize",           CC"()I",                    FN_PTR(Unsafe_PageSize)},
1538 
1539     {CC"defineClass",        CC"("DC0_Args")"CLS,        FN_PTR(Unsafe_DefineClass0)},
1540     {CC"defineClass",        CC"("DC_Args")"CLS,         FN_PTR(Unsafe_DefineClass)},
1541     {CC"allocateInstance",   CC"("CLS")"OBJ,             FN_PTR(Unsafe_AllocateInstance)},
1542     {CC"monitorEnter",       CC"("OBJ")V",               FN_PTR(Unsafe_MonitorEnter)},
1543     {CC"monitorExit",        CC"("OBJ")V",               FN_PTR(Unsafe_MonitorExit)},
1544     {CC"throwException",     CC"("THR")V",               FN_PTR(Unsafe_ThrowException)},
1545     {CC"compareAndSwapObject", CC"("OBJ"J"OBJ""OBJ")Z",  FN_PTR(Unsafe_CompareAndSwapObject)},
1546     {CC"compareAndSwapInt",  CC"("OBJ"J""I""I"")Z",      FN_PTR(Unsafe_CompareAndSwapInt)},
1547     {CC"compareAndSwapLong", CC"("OBJ"J""J""J"")Z",      FN_PTR(Unsafe_CompareAndSwapLong)},
1548     {CC"park",               CC"(ZJ)V",                  FN_PTR(Unsafe_Park)},
1549     {CC"unpark",             CC"("OBJ")V",               FN_PTR(Unsafe_Unpark)}
1550 
1551 };
1552 
1553 // These are the methods for 1.6.0 and 1.7.0
1554 static JNINativeMethod methods_16[] = {
1555     {CC"getObject",        CC"("OBJ"J)"OBJ"",   FN_PTR(Unsafe_GetObject)},
1556     {CC"putObject",        CC"("OBJ"J"OBJ")V",  FN_PTR(Unsafe_SetObject)},
1557     {CC"getObjectVolatile",CC"("OBJ"J)"OBJ"",   FN_PTR(Unsafe_GetObjectVolatile)},
1558     {CC"putObjectVolatile",CC"("OBJ"J"OBJ")V",  FN_PTR(Unsafe_SetObjectVolatile)},
1559 
1560     DECLARE_GETSETOOP(Boolean, Z),
1561     DECLARE_GETSETOOP(Byte, B),
1562     DECLARE_GETSETOOP(Short, S),
1563     DECLARE_GETSETOOP(Char, C),
1564     DECLARE_GETSETOOP(Int, I),
1565     DECLARE_GETSETOOP(Long, J),
1566     DECLARE_GETSETOOP(Float, F),
1567     DECLARE_GETSETOOP(Double, D),
1568 
1569     DECLARE_GETSETNATIVE(Byte, B),
1570     DECLARE_GETSETNATIVE(Short, S),
1571     DECLARE_GETSETNATIVE(Char, C),
1572     DECLARE_GETSETNATIVE(Int, I),
1573     DECLARE_GETSETNATIVE(Long, J),
1574     DECLARE_GETSETNATIVE(Float, F),
1575     DECLARE_GETSETNATIVE(Double, D),
1576 
1577     {CC"getAddress",         CC"("ADR")"ADR,             FN_PTR(Unsafe_GetNativeAddress)},
1578     {CC"putAddress",         CC"("ADR""ADR")V",          FN_PTR(Unsafe_SetNativeAddress)},
1579 
1580     {CC"allocateMemory",     CC"(J)"ADR,                 FN_PTR(Unsafe_AllocateMemory)},
1581     {CC"reallocateMemory",   CC"("ADR"J)"ADR,            FN_PTR(Unsafe_ReallocateMemory)},
1582     {CC"freeMemory",         CC"("ADR")V",               FN_PTR(Unsafe_FreeMemory)},
1583 
1584     {CC"objectFieldOffset",  CC"("FLD")J",               FN_PTR(Unsafe_ObjectFieldOffset)},
1585     {CC"staticFieldOffset",  CC"("FLD")J",               FN_PTR(Unsafe_StaticFieldOffset)},
1586     {CC"staticFieldBase",    CC"("FLD")"OBJ,             FN_PTR(Unsafe_StaticFieldBaseFromField)},
1587     {CC"ensureClassInitialized",CC"("CLS")V",            FN_PTR(Unsafe_EnsureClassInitialized)},
1588     {CC"arrayBaseOffset",    CC"("CLS")I",               FN_PTR(Unsafe_ArrayBaseOffset)},
1589     {CC"arrayIndexScale",    CC"("CLS")I",               FN_PTR(Unsafe_ArrayIndexScale)},
1590     {CC"addressSize",        CC"()I",                    FN_PTR(Unsafe_AddressSize)},
1591     {CC"pageSize",           CC"()I",                    FN_PTR(Unsafe_PageSize)},
1592 
1593     {CC"defineClass",        CC"("DC0_Args")"CLS,        FN_PTR(Unsafe_DefineClass0)},
1594     {CC"defineClass",        CC"("DC_Args")"CLS,         FN_PTR(Unsafe_DefineClass)},
1595     {CC"allocateInstance",   CC"("CLS")"OBJ,             FN_PTR(Unsafe_AllocateInstance)},
1596     {CC"monitorEnter",       CC"("OBJ")V",               FN_PTR(Unsafe_MonitorEnter)},
1597     {CC"monitorExit",        CC"("OBJ")V",               FN_PTR(Unsafe_MonitorExit)},
1598     {CC"tryMonitorEnter",    CC"("OBJ")Z",               FN_PTR(Unsafe_TryMonitorEnter)},
1599     {CC"throwException",     CC"("THR")V",               FN_PTR(Unsafe_ThrowException)},
1600     {CC"compareAndSwapObject", CC"("OBJ"J"OBJ""OBJ")Z",  FN_PTR(Unsafe_CompareAndSwapObject)},
1601     {CC"compareAndSwapInt",  CC"("OBJ"J""I""I"")Z",      FN_PTR(Unsafe_CompareAndSwapInt)},
1602     {CC"compareAndSwapLong", CC"("OBJ"J""J""J"")Z",      FN_PTR(Unsafe_CompareAndSwapLong)},
1603     {CC"putOrderedObject",   CC"("OBJ"J"OBJ")V",         FN_PTR(Unsafe_SetOrderedObject)},
1604     {CC"putOrderedInt",      CC"("OBJ"JI)V",             FN_PTR(Unsafe_SetOrderedInt)},
1605     {CC"putOrderedLong",     CC"("OBJ"JJ)V",             FN_PTR(Unsafe_SetOrderedLong)},
1606     {CC"park",               CC"(ZJ)V",                  FN_PTR(Unsafe_Park)},
1607     {CC"unpark",             CC"("OBJ")V",               FN_PTR(Unsafe_Unpark)}
1608 };
1609 
1610 // These are the methods for 1.8.0
1611 static JNINativeMethod methods_18[] = {
1612     {CC"getObject",        CC"("OBJ"J)"OBJ"",   FN_PTR(Unsafe_GetObject)},
1613     {CC"putObject",        CC"("OBJ"J"OBJ")V",  FN_PTR(Unsafe_SetObject)},
1614     {CC"getObjectVolatile",CC"("OBJ"J)"OBJ"",   FN_PTR(Unsafe_GetObjectVolatile)},
1615     {CC"putObjectVolatile",CC"("OBJ"J"OBJ")V",  FN_PTR(Unsafe_SetObjectVolatile)},
1616 
1617     DECLARE_GETSETOOP(Boolean, Z),
1618     DECLARE_GETSETOOP(Byte, B),
1619     DECLARE_GETSETOOP(Short, S),
1620     DECLARE_GETSETOOP(Char, C),
1621     DECLARE_GETSETOOP(Int, I),
1622     DECLARE_GETSETOOP(Long, J),
1623     DECLARE_GETSETOOP(Float, F),
1624     DECLARE_GETSETOOP(Double, D),
1625 
1626     DECLARE_GETSETNATIVE(Byte, B),
1627     DECLARE_GETSETNATIVE(Short, S),
1628     DECLARE_GETSETNATIVE(Char, C),
1629     DECLARE_GETSETNATIVE(Int, I),
1630     DECLARE_GETSETNATIVE(Long, J),
1631     DECLARE_GETSETNATIVE(Float, F),
1632     DECLARE_GETSETNATIVE(Double, D),
1633 
1634     {CC"getAddress",         CC"("ADR")"ADR,             FN_PTR(Unsafe_GetNativeAddress)},
1635     {CC"putAddress",         CC"("ADR""ADR")V",          FN_PTR(Unsafe_SetNativeAddress)},
1636 
1637     {CC"allocateMemory",     CC"(J)"ADR,                 FN_PTR(Unsafe_AllocateMemory)},
1638     {CC"reallocateMemory",   CC"("ADR"J)"ADR,            FN_PTR(Unsafe_ReallocateMemory)},
1639     {CC"freeMemory",         CC"("ADR")V",               FN_PTR(Unsafe_FreeMemory)},
1640 
1641     {CC"objectFieldOffset",  CC"("FLD")J",               FN_PTR(Unsafe_ObjectFieldOffset)},
1642     {CC"staticFieldOffset",  CC"("FLD")J",               FN_PTR(Unsafe_StaticFieldOffset)},
1643     {CC"staticFieldBase",    CC"("FLD")"OBJ,             FN_PTR(Unsafe_StaticFieldBaseFromField)},
1644     {CC"ensureClassInitialized",CC"("CLS")V",            FN_PTR(Unsafe_EnsureClassInitialized)},
1645     {CC"arrayBaseOffset",    CC"("CLS")I",               FN_PTR(Unsafe_ArrayBaseOffset)},
1646     {CC"arrayIndexScale",    CC"("CLS")I",               FN_PTR(Unsafe_ArrayIndexScale)},
1647     {CC"addressSize",        CC"()I",                    FN_PTR(Unsafe_AddressSize)},
1648     {CC"pageSize",           CC"()I",                    FN_PTR(Unsafe_PageSize)},
1649 
1650     {CC"defineClass",        CC"("DC_Args")"CLS,         FN_PTR(Unsafe_DefineClass)},
1651     {CC"allocateInstance",   CC"("CLS")"OBJ,             FN_PTR(Unsafe_AllocateInstance)},
1652     {CC"monitorEnter",       CC"("OBJ")V",               FN_PTR(Unsafe_MonitorEnter)},
1653     {CC"monitorExit",        CC"("OBJ")V",               FN_PTR(Unsafe_MonitorExit)},
1654     {CC"tryMonitorEnter",    CC"("OBJ")Z",               FN_PTR(Unsafe_TryMonitorEnter)},
1655     {CC"throwException",     CC"("THR")V",               FN_PTR(Unsafe_ThrowException)},
1656     {CC"compareAndSwapObject", CC"("OBJ"J"OBJ""OBJ")Z",  FN_PTR(Unsafe_CompareAndSwapObject)},
1657     {CC"compareAndSwapInt",  CC"("OBJ"J""I""I"")Z",      FN_PTR(Unsafe_CompareAndSwapInt)},
1658     {CC"compareAndSwapLong", CC"("OBJ"J""J""J"")Z",      FN_PTR(Unsafe_CompareAndSwapLong)},
1659     {CC"putOrderedObject",   CC"("OBJ"J"OBJ")V",         FN_PTR(Unsafe_SetOrderedObject)},
1660     {CC"putOrderedInt",      CC"("OBJ"JI)V",             FN_PTR(Unsafe_SetOrderedInt)},
1661     {CC"putOrderedLong",     CC"("OBJ"JJ)V",             FN_PTR(Unsafe_SetOrderedLong)},
1662     {CC"park",               CC"(ZJ)V",                  FN_PTR(Unsafe_Park)},
1663     {CC"unpark",             CC"("OBJ")V",               FN_PTR(Unsafe_Unpark)}
1664 };
1665 
1666 JNINativeMethod loadavg_method[] = {
1667     {CC"getLoadAverage",     CC"([DI)I",                 FN_PTR(Unsafe_Loadavg)}
1668 };
1669 
1670 JNINativeMethod prefetch_methods[] = {
1671     {CC"prefetchRead",       CC"("OBJ"J)V",              FN_PTR(Unsafe_PrefetchRead)},
1672     {CC"prefetchWrite",      CC"("OBJ"J)V",              FN_PTR(Unsafe_PrefetchWrite)},
1673     {CC"prefetchReadStatic", CC"("OBJ"J)V",              FN_PTR(Unsafe_PrefetchRead)},
1674     {CC"prefetchWriteStatic",CC"("OBJ"J)V",              FN_PTR(Unsafe_PrefetchWrite)}
1675 };
1676 
1677 JNINativeMethod memcopy_methods_17[] = {
1678     {CC"copyMemory",         CC"("OBJ"J"OBJ"JJ)V",       FN_PTR(Unsafe_CopyMemory2)},
1679     {CC"setMemory",          CC"("OBJ"JJB)V",            FN_PTR(Unsafe_SetMemory2)}
1680 };
1681 
1682 JNINativeMethod memcopy_methods_15[] = {
1683     {CC"setMemory",          CC"("ADR"JB)V",             FN_PTR(Unsafe_SetMemory)},
1684     {CC"copyMemory",         CC"("ADR ADR"J)V",          FN_PTR(Unsafe_CopyMemory)}
1685 };
1686 
1687 JNINativeMethod anonk_methods[] = {
1688     {CC"defineAnonymousClass", CC"("DAC_Args")"CLS,      FN_PTR(Unsafe_DefineAnonymousClass)},
1689 };
1690 
1691 JNINativeMethod lform_methods[] = {
1692     {CC"shouldBeInitialized",CC"("CLS")Z",               FN_PTR(Unsafe_ShouldBeInitialized)},
1693 };
1694 
1695 JNINativeMethod fence_methods[] = {
1696     {CC"loadFence",          CC"()V",                    FN_PTR(Unsafe_LoadFence)},
1697     {CC"storeFence",         CC"()V",                    FN_PTR(Unsafe_StoreFence)},
1698     {CC"fullFence",          CC"()V",                    FN_PTR(Unsafe_FullFence)},
1699 };
1700 
1701 #undef CC
1702 #undef FN_PTR
1703 
1704 #undef ADR
1705 #undef LANG
1706 #undef OBJ
1707 #undef CLS
1708 #undef CTR
1709 #undef FLD
1710 #undef MTH
1711 #undef THR
1712 #undef DC0_Args
1713 #undef DC_Args
1714 
1715 #undef DECLARE_GETSETOOP
1716 #undef DECLARE_GETSETNATIVE
1717 
1718 
1719 /**
1720  * Helper method to register native methods.
1721  */
1722 static bool register_natives(const char* message, JNIEnv* env, jclass clazz, const JNINativeMethod* methods, jint nMethods) {
1723   int status = env->RegisterNatives(clazz, methods, nMethods);
1724   if (status < 0 || env->ExceptionOccurred()) {
1725     if (PrintMiscellaneous && (Verbose || WizardMode)) {
1726       tty->print_cr("Unsafe:  failed registering %s", message);
1727     }
1728     env->ExceptionClear();
1729     return false;
1730   } else {
1731     if (PrintMiscellaneous && (Verbose || WizardMode)) {
1732       tty->print_cr("Unsafe:  successfully registered %s", message);
1733     }
1734     return true;
1735   }
1736 }
1737 
1738 
1739 // This one function is exported, used by NativeLookup.
1740 // The Unsafe_xxx functions above are called only from the interpreter.
1741 // The optimizer looks at names and signatures to recognize
1742 // individual functions.
1743 
1744 JVM_ENTRY(void, JVM_RegisterUnsafeMethods(JNIEnv *env, jclass unsafecls))
1745   UnsafeWrapper("JVM_RegisterUnsafeMethods");
1746   {
1747     ThreadToNativeFromVM ttnfv(thread);
1748 
1749     // Unsafe methods
1750     {
1751       bool success = false;
1752       // We need to register the 1.6 methods first because the 1.8 methods would register fine on 1.7 and 1.6
1753       if (!success) {
1754         success = register_natives("1.6 methods",   env, unsafecls, methods_16,  sizeof(methods_16)/sizeof(JNINativeMethod));
1755       }
1756       if (!success) {
1757         success = register_natives("1.8 methods",   env, unsafecls, methods_18,  sizeof(methods_18)/sizeof(JNINativeMethod));
1758       }
1759       if (!success) {
1760         success = register_natives("1.5 methods",   env, unsafecls, methods_15,  sizeof(methods_15)/sizeof(JNINativeMethod));
1761       }
1762       if (!success) {
1763         success = register_natives("1.4.1 methods", env, unsafecls, methods_141, sizeof(methods_141)/sizeof(JNINativeMethod));
1764       }
1765       if (!success) {
1766         success = register_natives("1.4.0 methods", env, unsafecls, methods_140, sizeof(methods_140)/sizeof(JNINativeMethod));
1767       }
1768       guarantee(success, "register unsafe natives");
1769     }
1770 
1771     // Unsafe.getLoadAverage
1772     register_natives("1.6 loadavg method", env, unsafecls, loadavg_method, sizeof(loadavg_method)/sizeof(JNINativeMethod));
1773 
1774     // Prefetch methods
1775     register_natives("1.6 prefetch methods", env, unsafecls, prefetch_methods, sizeof(prefetch_methods)/sizeof(JNINativeMethod));
1776 
1777     // Memory copy methods
1778     {
1779       bool success = false;
1780       if (!success) {
1781         success = register_natives("1.7 memory copy methods", env, unsafecls, memcopy_methods_17, sizeof(memcopy_methods_17)/sizeof(JNINativeMethod));
1782       }
1783       if (!success) {
1784         success = register_natives("1.5 memory copy methods", env, unsafecls, memcopy_methods_15, sizeof(memcopy_methods_15)/sizeof(JNINativeMethod));
1785       }
1786     }
1787 
1788     // Unsafe.defineAnonymousClass
1789     if (EnableInvokeDynamic) {
1790       register_natives("1.7 define anonymous class method", env, unsafecls, anonk_methods, sizeof(anonk_methods)/sizeof(JNINativeMethod));
1791     }
1792 
1793     // Unsafe.shouldBeInitialized
1794     if (EnableInvokeDynamic) {
1795       register_natives("1.7 LambdaForm support", env, unsafecls, lform_methods, sizeof(lform_methods)/sizeof(JNINativeMethod));
1796     }
1797 
1798     // Fence methods
1799     register_natives("1.8 fence methods", env, unsafecls, fence_methods, sizeof(fence_methods)/sizeof(JNINativeMethod));
1800   }
1801 JVM_END