1 /*
2 * Copyright (c) 2000, 2017, 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/vmSymbols.hpp"
30 #include "memory/allocation.inline.hpp"
31 #include "memory/resourceArea.hpp"
32 #include "oops/access.inline.hpp"
33 #include "oops/fieldStreams.hpp"
34 #include "oops/objArrayOop.inline.hpp"
35 #include "oops/oop.inline.hpp"
36 #include "prims/unsafe.hpp"
37 #include "runtime/atomic.hpp"
38 #include "runtime/globals.hpp"
39 #include "runtime/interfaceSupport.hpp"
40 #include "runtime/orderAccess.inline.hpp"
41 #include "runtime/reflection.hpp"
42 #include "runtime/thread.hpp"
43 #include "runtime/threadSMR.hpp"
44 #include "runtime/vm_version.hpp"
45 #include "services/threadService.hpp"
46 #include "trace/tracing.hpp"
47 #include "utilities/align.hpp"
48 #include "utilities/copy.hpp"
49 #include "utilities/dtrace.hpp"
50 #include "utilities/macros.hpp"
51
52 /**
53 * Implementation of the jdk.internal.misc.Unsafe class
54 */
55
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(static result_type, header)
64
65 #define UNSAFE_LEAF(result_type, header) \
66 JVM_LEAF(static result_type, header)
67
68 #define UNSAFE_END JVM_END
69
70
71 static inline void* addr_from_java(jlong addr) {
72 // This assert fails in a variety of ways on 32-bit systems.
73 // It is impossible to predict whether native code that converts
74 // pointers to longs will sign-extend or zero-extend the addresses.
75 //assert(addr == (uintptr_t)addr, "must not be odd high bits");
76 return (void*)(uintptr_t)addr;
77 }
78
79 static inline jlong addr_to_java(void* p) {
80 assert(p == (void*)(uintptr_t)p, "must not be odd high bits");
81 return (uintptr_t)p;
82 }
83
84
85 // Note: The VM's obj_field and related accessors use byte-scaled
86 // ("unscaled") offsets, just as the unsafe methods do.
87
88 // However, the method Unsafe.fieldOffset explicitly declines to
89 // guarantee this. The field offset values manipulated by the Java user
90 // through the Unsafe API are opaque cookies that just happen to be byte
91 // offsets. We represent this state of affairs by passing the cookies
92 // through conversion functions when going between the VM and the Unsafe API.
93 // The conversion functions just happen to be no-ops at present.
94
95 static inline jlong field_offset_to_byte_offset(jlong field_offset) {
96 return field_offset;
97 }
98
99 static inline jlong field_offset_from_byte_offset(jlong byte_offset) {
100 return byte_offset;
101 }
102
103 static inline void assert_field_offset_sane(oop p, jlong field_offset) {
104 #ifdef ASSERT
105 jlong byte_offset = field_offset_to_byte_offset(field_offset);
106
107 if (p != NULL) {
108 assert(byte_offset >= 0 && byte_offset <= (jlong)MAX_OBJECT_SIZE, "sane offset");
109 if (byte_offset == (jint)byte_offset) {
110 void* ptr_plus_disp = (address)p + byte_offset;
111 assert((void*)p->obj_field_addr<oop>((jint)byte_offset) == ptr_plus_disp,
112 "raw [ptr+disp] must be consistent with oop::field_base");
113 }
114 jlong p_size = HeapWordSize * (jlong)(p->size());
115 assert(byte_offset < p_size, "Unsafe access: offset " INT64_FORMAT " > object's size " INT64_FORMAT, (int64_t)byte_offset, (int64_t)p_size);
116 }
117 #endif
118 }
119
120 static inline void* index_oop_from_field_offset_long(oop p, jlong field_offset) {
121 assert_field_offset_sane(p, field_offset);
122 jlong byte_offset = field_offset_to_byte_offset(field_offset);
123
124 if (sizeof(char*) == sizeof(jint)) { // (this constant folds!)
125 return (address)p + (jint) byte_offset;
126 } else {
127 return (address)p + byte_offset;
128 }
129 }
130
131 // Externally callable versions:
132 // (Use these in compiler intrinsics which emulate unsafe primitives.)
133 jlong Unsafe_field_offset_to_byte_offset(jlong field_offset) {
134 return field_offset;
135 }
136 jlong Unsafe_field_offset_from_byte_offset(jlong byte_offset) {
137 return byte_offset;
138 }
139
140
141 ///// Data read/writes on the Java heap and in native (off-heap) memory
142
143 /**
144 * Helper class for accessing memory.
145 *
146 * Normalizes values and wraps accesses in
147 * JavaThread::doing_unsafe_access() if needed.
148 */
149 class MemoryAccess : StackObj {
150 JavaThread* _thread;
151 oop _obj;
152 ptrdiff_t _offset;
153
154 // Resolves and returns the address of the memory access
155 void* addr() {
156 return index_oop_from_field_offset_long(_obj, _offset);
157 }
158
159 template <typename T>
160 T normalize_for_write(T x) {
161 return x;
162 }
163
164 jboolean normalize_for_write(jboolean x) {
165 return x & 1;
166 }
167
168 template <typename T>
169 T normalize_for_read(T x) {
170 return x;
171 }
172
173 jboolean normalize_for_read(jboolean x) {
174 return x != 0;
175 }
176
177 /**
178 * Helper class to wrap memory accesses in JavaThread::doing_unsafe_access()
179 */
180 class GuardUnsafeAccess {
181 JavaThread* _thread;
182
183 public:
184 GuardUnsafeAccess(JavaThread* thread) : _thread(thread) {
185 // native/off-heap access which may raise SIGBUS if accessing
186 // memory mapped file data in a region of the file which has
187 // been truncated and is now invalid
188 _thread->set_doing_unsafe_access(true);
189 }
190
191 ~GuardUnsafeAccess() {
192 _thread->set_doing_unsafe_access(false);
193 }
194 };
195
196 public:
197 MemoryAccess(JavaThread* thread, jobject obj, jlong offset)
198 : _thread(thread), _obj(JNIHandles::resolve(obj)), _offset((ptrdiff_t)offset) {
199 assert_field_offset_sane(_obj, offset);
200 }
201
202 template <typename T>
203 T get() {
204 if (oopDesc::is_null(_obj)) {
205 GuardUnsafeAccess guard(_thread);
206 T ret = RawAccess<>::load((volatile T*)addr());
207 return normalize_for_read(ret);
208 } else {
209 T ret = HeapAccess<>::load_at(_obj, _offset);
210 return normalize_for_read(ret);
211 }
212 }
213
214 template <typename T>
215 void put(T x) {
216 if (oopDesc::is_null(_obj)) {
217 GuardUnsafeAccess guard(_thread);
218 RawAccess<>::store((volatile T*)addr(), normalize_for_write(x));
219 } else {
220 HeapAccess<>::store_at(_obj, _offset, normalize_for_write(x));
221 }
222 }
223
224
225 template <typename T>
226 T get_volatile() {
227 if (oopDesc::is_null(_obj)) {
228 GuardUnsafeAccess guard(_thread);
229 volatile T ret = RawAccess<MO_SEQ_CST>::load((volatile T*)addr());
230 return normalize_for_read(ret);
231 } else {
232 T ret = HeapAccess<MO_SEQ_CST>::load_at(_obj, _offset);
233 return normalize_for_read(ret);
234 }
235 }
236
237 template <typename T>
238 void put_volatile(T x) {
239 if (oopDesc::is_null(_obj)) {
240 GuardUnsafeAccess guard(_thread);
241 RawAccess<MO_SEQ_CST>::store((volatile T*)addr(), normalize_for_write(x));
242 } else {
243 HeapAccess<MO_SEQ_CST>::store_at(_obj, _offset, normalize_for_write(x));
244 }
245 }
246 };
247
248 // These functions allow a null base pointer with an arbitrary address.
249 // But if the base pointer is non-null, the offset should make some sense.
250 // That is, it should be in the range [0, MAX_OBJECT_SIZE].
251 UNSAFE_ENTRY(jobject, Unsafe_GetObject(JNIEnv *env, jobject unsafe, jobject obj, jlong offset)) {
252 oop p = JNIHandles::resolve(obj);
253 assert_field_offset_sane(p, offset);
254 oop v = HeapAccess<ON_UNKNOWN_OOP_REF>::oop_load_at(p, offset);
255 return JNIHandles::make_local(env, v);
256 } UNSAFE_END
257
258 UNSAFE_ENTRY(void, Unsafe_PutObject(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jobject x_h)) {
259 oop x = JNIHandles::resolve(x_h);
260 oop p = JNIHandles::resolve(obj);
261 assert_field_offset_sane(p, offset);
262 HeapAccess<ON_UNKNOWN_OOP_REF>::oop_store_at(p, offset, x);
263 } UNSAFE_END
264
265 UNSAFE_ENTRY(jobject, Unsafe_GetObjectVolatile(JNIEnv *env, jobject unsafe, jobject obj, jlong offset)) {
266 oop p = JNIHandles::resolve(obj);
267 assert_field_offset_sane(p, offset);
268 oop v = HeapAccess<MO_SEQ_CST | ON_UNKNOWN_OOP_REF>::oop_load_at(p, offset);
269 return JNIHandles::make_local(env, v);
270 } UNSAFE_END
271
272 UNSAFE_ENTRY(void, Unsafe_PutObjectVolatile(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jobject x_h)) {
273 oop x = JNIHandles::resolve(x_h);
274 oop p = JNIHandles::resolve(obj);
275 assert_field_offset_sane(p, offset);
276 HeapAccess<MO_SEQ_CST | ON_UNKNOWN_OOP_REF>::oop_store_at(p, offset, x);
277 } UNSAFE_END
278
279 UNSAFE_ENTRY(jobject, Unsafe_GetUncompressedObject(JNIEnv *env, jobject unsafe, jlong addr)) {
280 oop v = *(oop*) (address) addr;
281 return JNIHandles::make_local(env, v);
282 } UNSAFE_END
283
284 UNSAFE_LEAF(jboolean, Unsafe_isBigEndian0(JNIEnv *env, jobject unsafe)) {
285 #ifdef VM_LITTLE_ENDIAN
286 return false;
287 #else
288 return true;
289 #endif
290 } UNSAFE_END
291
292 UNSAFE_LEAF(jint, Unsafe_unalignedAccess0(JNIEnv *env, jobject unsafe)) {
293 return UseUnalignedAccesses;
294 } UNSAFE_END
295
296 #define DEFINE_GETSETOOP(java_type, Type) \
297 \
298 UNSAFE_ENTRY(java_type, Unsafe_Get##Type(JNIEnv *env, jobject unsafe, jobject obj, jlong offset)) { \
299 return MemoryAccess(thread, obj, offset).get<java_type>(); \
300 } UNSAFE_END \
301 \
302 UNSAFE_ENTRY(void, Unsafe_Put##Type(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, java_type x)) { \
303 MemoryAccess(thread, obj, offset).put<java_type>(x); \
304 } UNSAFE_END \
305 \
306 // END DEFINE_GETSETOOP.
307
308 DEFINE_GETSETOOP(jboolean, Boolean)
309 DEFINE_GETSETOOP(jbyte, Byte)
310 DEFINE_GETSETOOP(jshort, Short);
311 DEFINE_GETSETOOP(jchar, Char);
312 DEFINE_GETSETOOP(jint, Int);
313 DEFINE_GETSETOOP(jlong, Long);
314 DEFINE_GETSETOOP(jfloat, Float);
315 DEFINE_GETSETOOP(jdouble, Double);
316
317 #undef DEFINE_GETSETOOP
318
319 #define DEFINE_GETSETOOP_VOLATILE(java_type, Type) \
320 \
321 UNSAFE_ENTRY(java_type, Unsafe_Get##Type##Volatile(JNIEnv *env, jobject unsafe, jobject obj, jlong offset)) { \
322 return MemoryAccess(thread, obj, offset).get_volatile<java_type>(); \
323 } UNSAFE_END \
324 \
325 UNSAFE_ENTRY(void, Unsafe_Put##Type##Volatile(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, java_type x)) { \
326 MemoryAccess(thread, obj, offset).put_volatile<java_type>(x); \
327 } UNSAFE_END \
328 \
329 // END DEFINE_GETSETOOP_VOLATILE.
330
331 DEFINE_GETSETOOP_VOLATILE(jboolean, Boolean)
332 DEFINE_GETSETOOP_VOLATILE(jbyte, Byte)
333 DEFINE_GETSETOOP_VOLATILE(jshort, Short);
334 DEFINE_GETSETOOP_VOLATILE(jchar, Char);
335 DEFINE_GETSETOOP_VOLATILE(jint, Int);
336 DEFINE_GETSETOOP_VOLATILE(jlong, Long);
337 DEFINE_GETSETOOP_VOLATILE(jfloat, Float);
338 DEFINE_GETSETOOP_VOLATILE(jdouble, Double);
339
340 #undef DEFINE_GETSETOOP_VOLATILE
341
342 UNSAFE_LEAF(void, Unsafe_LoadFence(JNIEnv *env, jobject unsafe)) {
343 OrderAccess::acquire();
344 } UNSAFE_END
345
346 UNSAFE_LEAF(void, Unsafe_StoreFence(JNIEnv *env, jobject unsafe)) {
347 OrderAccess::release();
348 } UNSAFE_END
349
350 UNSAFE_LEAF(void, Unsafe_FullFence(JNIEnv *env, jobject unsafe)) {
351 OrderAccess::fence();
352 } UNSAFE_END
353
354 ////// Allocation requests
355
356 UNSAFE_ENTRY(jobject, Unsafe_AllocateInstance(JNIEnv *env, jobject unsafe, jclass cls)) {
357 ThreadToNativeFromVM ttnfv(thread);
358 return env->AllocObject(cls);
359 } UNSAFE_END
360
361 UNSAFE_ENTRY(jlong, Unsafe_AllocateMemory0(JNIEnv *env, jobject unsafe, jlong size)) {
362 size_t sz = (size_t)size;
363
364 sz = align_up(sz, HeapWordSize);
365 void* x = os::malloc(sz, mtInternal);
366
367 return addr_to_java(x);
368 } UNSAFE_END
369
370 UNSAFE_ENTRY(jlong, Unsafe_ReallocateMemory0(JNIEnv *env, jobject unsafe, jlong addr, jlong size)) {
371 void* p = addr_from_java(addr);
372 size_t sz = (size_t)size;
373 sz = align_up(sz, HeapWordSize);
374
375 void* x = os::realloc(p, sz, mtInternal);
376
377 return addr_to_java(x);
378 } UNSAFE_END
379
380 UNSAFE_ENTRY(void, Unsafe_FreeMemory0(JNIEnv *env, jobject unsafe, jlong addr)) {
381 void* p = addr_from_java(addr);
382
383 os::free(p);
384 } UNSAFE_END
385
386 UNSAFE_ENTRY(void, Unsafe_SetMemory0(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jlong size, jbyte value)) {
387 size_t sz = (size_t)size;
388
389 oop base = JNIHandles::resolve(obj);
390 void* p = index_oop_from_field_offset_long(base, offset);
391
392 Copy::fill_to_memory_atomic(p, sz, value);
393 } UNSAFE_END
394
395 UNSAFE_ENTRY(void, Unsafe_CopyMemory0(JNIEnv *env, jobject unsafe, jobject srcObj, jlong srcOffset, jobject dstObj, jlong dstOffset, jlong size)) {
396 size_t sz = (size_t)size;
397
398 oop srcp = JNIHandles::resolve(srcObj);
399 oop dstp = JNIHandles::resolve(dstObj);
400
401 void* src = index_oop_from_field_offset_long(srcp, srcOffset);
402 void* dst = index_oop_from_field_offset_long(dstp, dstOffset);
403
404 Copy::conjoint_memory_atomic(src, dst, sz);
405 } UNSAFE_END
406
407 // This function is a leaf since if the source and destination are both in native memory
408 // the copy may potentially be very large, and we don't want to disable GC if we can avoid it.
409 // If either source or destination (or both) are on the heap, the function will enter VM using
410 // JVM_ENTRY_FROM_LEAF
411 UNSAFE_LEAF(void, Unsafe_CopySwapMemory0(JNIEnv *env, jobject unsafe, jobject srcObj, jlong srcOffset, jobject dstObj, jlong dstOffset, jlong size, jlong elemSize)) {
412 size_t sz = (size_t)size;
413 size_t esz = (size_t)elemSize;
414
415 if (srcObj == NULL && dstObj == NULL) {
416 // Both src & dst are in native memory
417 address src = (address)srcOffset;
418 address dst = (address)dstOffset;
419
420 Copy::conjoint_swap(src, dst, sz, esz);
421 } else {
422 // At least one of src/dst are on heap, transition to VM to access raw pointers
423
424 JVM_ENTRY_FROM_LEAF(env, void, Unsafe_CopySwapMemory0) {
425 oop srcp = JNIHandles::resolve(srcObj);
426 oop dstp = JNIHandles::resolve(dstObj);
427
428 address src = (address)index_oop_from_field_offset_long(srcp, srcOffset);
429 address dst = (address)index_oop_from_field_offset_long(dstp, dstOffset);
430
431 Copy::conjoint_swap(src, dst, sz, esz);
432 } JVM_END
433 }
434 } UNSAFE_END
435
436 ////// Random queries
437
438 UNSAFE_LEAF(jint, Unsafe_AddressSize0(JNIEnv *env, jobject unsafe)) {
439 return sizeof(void*);
440 } UNSAFE_END
441
442 UNSAFE_LEAF(jint, Unsafe_PageSize()) {
443 return os::vm_page_size();
444 } UNSAFE_END
445
446 static jlong find_field_offset(jclass clazz, jstring name, TRAPS) {
447 assert(clazz != NULL, "clazz must not be NULL");
448 assert(name != NULL, "name must not be NULL");
449
450 ResourceMark rm(THREAD);
451 char *utf_name = java_lang_String::as_utf8_string(JNIHandles::resolve_non_null(name));
452
453 InstanceKlass* k = InstanceKlass::cast(java_lang_Class::as_Klass(JNIHandles::resolve_non_null(clazz)));
454
455 jint offset = -1;
456 for (JavaFieldStream fs(k); !fs.done(); fs.next()) {
457 Symbol *name = fs.name();
458 if (name->equals(utf_name)) {
459 offset = fs.offset();
460 break;
461 }
462 }
463 if (offset < 0) {
464 THROW_0(vmSymbols::java_lang_InternalError());
465 }
466 return field_offset_from_byte_offset(offset);
467 }
468
469 static jlong find_field_offset(jobject field, int must_be_static, TRAPS) {
470 assert(field != NULL, "field must not be NULL");
471
472 oop reflected = JNIHandles::resolve_non_null(field);
473 oop mirror = java_lang_reflect_Field::clazz(reflected);
474 Klass* k = java_lang_Class::as_Klass(mirror);
475 int slot = java_lang_reflect_Field::slot(reflected);
476 int modifiers = java_lang_reflect_Field::modifiers(reflected);
477
478 if (must_be_static >= 0) {
479 int really_is_static = ((modifiers & JVM_ACC_STATIC) != 0);
480 if (must_be_static != really_is_static) {
481 THROW_0(vmSymbols::java_lang_IllegalArgumentException());
482 }
483 }
484
485 int offset = InstanceKlass::cast(k)->field_offset(slot);
486 return field_offset_from_byte_offset(offset);
487 }
488
489 UNSAFE_ENTRY(jlong, Unsafe_ObjectFieldOffset0(JNIEnv *env, jobject unsafe, jobject field)) {
490 return find_field_offset(field, 0, THREAD);
491 } UNSAFE_END
492
493 UNSAFE_ENTRY(jlong, Unsafe_ObjectFieldOffset1(JNIEnv *env, jobject unsafe, jclass c, jstring name)) {
494 return find_field_offset(c, name, THREAD);
495 } UNSAFE_END
496
497 UNSAFE_ENTRY(jlong, Unsafe_StaticFieldOffset0(JNIEnv *env, jobject unsafe, jobject field)) {
498 return find_field_offset(field, 1, THREAD);
499 } UNSAFE_END
500
501 UNSAFE_ENTRY(jobject, Unsafe_StaticFieldBase0(JNIEnv *env, jobject unsafe, jobject field)) {
502 assert(field != NULL, "field must not be NULL");
503
504 // Note: In this VM implementation, a field address is always a short
505 // offset from the base of a a klass metaobject. Thus, the full dynamic
506 // range of the return type is never used. However, some implementations
507 // might put the static field inside an array shared by many classes,
508 // or even at a fixed address, in which case the address could be quite
509 // large. In that last case, this function would return NULL, since
510 // the address would operate alone, without any base pointer.
511
512 oop reflected = JNIHandles::resolve_non_null(field);
513 oop mirror = java_lang_reflect_Field::clazz(reflected);
514 int modifiers = java_lang_reflect_Field::modifiers(reflected);
515
516 if ((modifiers & JVM_ACC_STATIC) == 0) {
517 THROW_0(vmSymbols::java_lang_IllegalArgumentException());
518 }
519
520 return JNIHandles::make_local(env, mirror);
521 } UNSAFE_END
522
523 UNSAFE_ENTRY(void, Unsafe_EnsureClassInitialized0(JNIEnv *env, jobject unsafe, jobject clazz)) {
524 assert(clazz != NULL, "clazz must not be NULL");
525
526 oop mirror = JNIHandles::resolve_non_null(clazz);
527
528 Klass* klass = java_lang_Class::as_Klass(mirror);
529 if (klass != NULL && klass->should_be_initialized()) {
530 InstanceKlass* k = InstanceKlass::cast(klass);
531 k->initialize(CHECK);
532 }
533 }
534 UNSAFE_END
535
536 UNSAFE_ENTRY(jboolean, Unsafe_ShouldBeInitialized0(JNIEnv *env, jobject unsafe, jobject clazz)) {
537 assert(clazz != NULL, "clazz must not be NULL");
538
539 oop mirror = JNIHandles::resolve_non_null(clazz);
540 Klass* klass = java_lang_Class::as_Klass(mirror);
541
542 if (klass != NULL && klass->should_be_initialized()) {
543 return true;
544 }
545
546 return false;
547 }
548 UNSAFE_END
549
550 static void getBaseAndScale(int& base, int& scale, jclass clazz, TRAPS) {
551 assert(clazz != NULL, "clazz must not be NULL");
552
553 oop mirror = JNIHandles::resolve_non_null(clazz);
554 Klass* k = java_lang_Class::as_Klass(mirror);
555
556 if (k == NULL || !k->is_array_klass()) {
557 THROW(vmSymbols::java_lang_InvalidClassException());
558 } else if (k->is_objArray_klass()) {
559 base = arrayOopDesc::base_offset_in_bytes(T_OBJECT);
560 scale = heapOopSize;
561 } else if (k->is_typeArray_klass()) {
562 TypeArrayKlass* tak = TypeArrayKlass::cast(k);
563 base = tak->array_header_in_bytes();
564 assert(base == arrayOopDesc::base_offset_in_bytes(tak->element_type()), "array_header_size semantics ok");
565 scale = (1 << tak->log2_element_size());
566 } else {
567 ShouldNotReachHere();
568 }
569 }
570
571 UNSAFE_ENTRY(jint, Unsafe_ArrayBaseOffset0(JNIEnv *env, jobject unsafe, jclass clazz)) {
572 int base = 0, scale = 0;
573 getBaseAndScale(base, scale, clazz, CHECK_0);
574
575 return field_offset_from_byte_offset(base);
576 } UNSAFE_END
577
578
579 UNSAFE_ENTRY(jint, Unsafe_ArrayIndexScale0(JNIEnv *env, jobject unsafe, jclass clazz)) {
580 int base = 0, scale = 0;
581 getBaseAndScale(base, scale, clazz, CHECK_0);
582
583 // This VM packs both fields and array elements down to the byte.
584 // But watch out: If this changes, so that array references for
585 // a given primitive type (say, T_BOOLEAN) use different memory units
586 // than fields, this method MUST return zero for such arrays.
587 // For example, the VM used to store sub-word sized fields in full
588 // words in the object layout, so that accessors like getByte(Object,int)
589 // did not really do what one might expect for arrays. Therefore,
590 // this function used to report a zero scale factor, so that the user
591 // would know not to attempt to access sub-word array elements.
592 // // Code for unpacked fields:
593 // if (scale < wordSize) return 0;
594
595 // The following allows for a pretty general fieldOffset cookie scheme,
596 // but requires it to be linear in byte offset.
597 return field_offset_from_byte_offset(scale) - field_offset_from_byte_offset(0);
598 } UNSAFE_END
599
600
601 static inline void throw_new(JNIEnv *env, const char *ename) {
602 jclass cls = env->FindClass(ename);
603 if (env->ExceptionCheck()) {
604 env->ExceptionClear();
605 tty->print_cr("Unsafe: cannot throw %s because FindClass has failed", ename);
606 return;
607 }
608
609 env->ThrowNew(cls, NULL);
610 }
611
612 static jclass Unsafe_DefineClass_impl(JNIEnv *env, jstring name, jbyteArray data, int offset, int length, jobject loader, jobject pd) {
613 // Code lifted from JDK 1.3 ClassLoader.c
614
615 jbyte *body;
616 char *utfName = NULL;
617 jclass result = 0;
618 char buf[128];
619
620 assert(data != NULL, "Class bytes must not be NULL");
621 assert(length >= 0, "length must not be negative: %d", length);
622
623 if (UsePerfData) {
624 ClassLoader::unsafe_defineClassCallCounter()->inc();
625 }
626
627 body = NEW_C_HEAP_ARRAY(jbyte, length, mtInternal);
628 if (body == NULL) {
629 throw_new(env, "java/lang/OutOfMemoryError");
630 return 0;
631 }
632
633 env->GetByteArrayRegion(data, offset, length, body);
634 if (env->ExceptionOccurred()) {
635 goto free_body;
636 }
637
638 if (name != NULL) {
639 uint len = env->GetStringUTFLength(name);
640 int unicode_len = env->GetStringLength(name);
641
642 if (len >= sizeof(buf)) {
643 utfName = NEW_C_HEAP_ARRAY(char, len + 1, mtInternal);
644 if (utfName == NULL) {
645 throw_new(env, "java/lang/OutOfMemoryError");
646 goto free_body;
647 }
648 } else {
649 utfName = buf;
650 }
651
652 env->GetStringUTFRegion(name, 0, unicode_len, utfName);
653
654 for (uint i = 0; i < len; i++) {
655 if (utfName[i] == '.') utfName[i] = '/';
656 }
657 }
658
659 result = JVM_DefineClass(env, utfName, loader, body, length, pd);
660
661 if (utfName && utfName != buf) {
662 FREE_C_HEAP_ARRAY(char, utfName);
663 }
664
665 free_body:
666 FREE_C_HEAP_ARRAY(jbyte, body);
667 return result;
668 }
669
670
671 UNSAFE_ENTRY(jclass, Unsafe_DefineClass0(JNIEnv *env, jobject unsafe, jstring name, jbyteArray data, int offset, int length, jobject loader, jobject pd)) {
672 ThreadToNativeFromVM ttnfv(thread);
673
674 return Unsafe_DefineClass_impl(env, name, data, offset, length, loader, pd);
675 } UNSAFE_END
676
677
678 // define a class but do not make it known to the class loader or system dictionary
679 // - host_class: supplies context for linkage, access control, protection domain, and class loader
680 // if host_class is itself anonymous then it is replaced with its host class.
681 // - data: bytes of a class file, a raw memory address (length gives the number of bytes)
682 // - cp_patches: where non-null entries exist, they replace corresponding CP entries in data
683
684 // When you load an anonymous class U, it works as if you changed its name just before loading,
685 // to a name that you will never use again. Since the name is lost, no other class can directly
686 // link to any member of U. Just after U is loaded, the only way to use it is reflectively,
687 // through java.lang.Class methods like Class.newInstance.
688
689 // The package of an anonymous class must either match its host's class's package or be in the
690 // unnamed package. If it is in the unnamed package then it will be put in its host class's
691 // package.
692 //
693
694 // Access checks for linkage sites within U continue to follow the same rules as for named classes.
695 // An anonymous class also has special privileges to access any member of its host class.
696 // This is the main reason why this loading operation is unsafe. The purpose of this is to
697 // allow language implementations to simulate "open classes"; a host class in effect gets
698 // new code when an anonymous class is loaded alongside it. A less convenient but more
699 // standard way to do this is with reflection, which can also be set to ignore access
700 // restrictions.
701
702 // Access into an anonymous class is possible only through reflection. Therefore, there
703 // are no special access rules for calling into an anonymous class. The relaxed access
704 // rule for the host class is applied in the opposite direction: A host class reflectively
705 // access one of its anonymous classes.
706
707 // If you load the same bytecodes twice, you get two different classes. You can reload
708 // the same bytecodes with or without varying CP patches.
709
710 // By using the CP patching array, you can have a new anonymous class U2 refer to an older one U1.
711 // The bytecodes for U2 should refer to U1 by a symbolic name (doesn't matter what the name is).
712 // The CONSTANT_Class entry for that name can be patched to refer directly to U1.
713
714 // This allows, for example, U2 to use U1 as a superclass or super-interface, or as
715 // an outer class (so that U2 is an anonymous inner class of anonymous U1).
716 // It is not possible for a named class, or an older anonymous class, to refer by
717 // name (via its CP) to a newer anonymous class.
718
719 // CP patching may also be used to modify (i.e., hack) the names of methods, classes,
720 // or type descriptors used in the loaded anonymous class.
721
722 // Finally, CP patching may be used to introduce "live" objects into the constant pool,
723 // instead of "dead" strings. A compiled statement like println((Object)"hello") can
724 // be changed to println(greeting), where greeting is an arbitrary object created before
725 // the anonymous class is loaded. This is useful in dynamic languages, in which
726 // various kinds of metaobjects must be introduced as constants into bytecode.
727 // Note the cast (Object), which tells the verifier to expect an arbitrary object,
728 // not just a literal string. For such ldc instructions, the verifier uses the
729 // type Object instead of String, if the loaded constant is not in fact a String.
730
731 static InstanceKlass*
732 Unsafe_DefineAnonymousClass_impl(JNIEnv *env,
733 jclass host_class, jbyteArray data, jobjectArray cp_patches_jh,
734 u1** temp_alloc,
735 TRAPS) {
736 assert(host_class != NULL, "host_class must not be NULL");
737 assert(data != NULL, "data must not be NULL");
738
739 if (UsePerfData) {
740 ClassLoader::unsafe_defineClassCallCounter()->inc();
741 }
742
743 jint length = typeArrayOop(JNIHandles::resolve_non_null(data))->length();
744 assert(length >= 0, "class_bytes_length must not be negative: %d", length);
745
746 int class_bytes_length = (int) length;
747
748 u1* class_bytes = NEW_C_HEAP_ARRAY(u1, length, mtInternal);
749 if (class_bytes == NULL) {
750 THROW_0(vmSymbols::java_lang_OutOfMemoryError());
751 }
752
753 // caller responsible to free it:
754 *temp_alloc = class_bytes;
755
756 jbyte* array_base = typeArrayOop(JNIHandles::resolve_non_null(data))->byte_at_addr(0);
757 Copy::conjoint_jbytes(array_base, class_bytes, length);
758
759 objArrayHandle cp_patches_h;
760 if (cp_patches_jh != NULL) {
761 oop p = JNIHandles::resolve_non_null(cp_patches_jh);
762 assert(p->is_objArray(), "cp_patches must be an object[]");
763 cp_patches_h = objArrayHandle(THREAD, (objArrayOop)p);
764 }
765
766 const Klass* host_klass = java_lang_Class::as_Klass(JNIHandles::resolve_non_null(host_class));
767
768 // Make sure it's the real host class, not another anonymous class.
769 while (host_klass != NULL && host_klass->is_instance_klass() &&
770 InstanceKlass::cast(host_klass)->is_anonymous()) {
771 host_klass = InstanceKlass::cast(host_klass)->host_klass();
772 }
773
774 // Primitive types have NULL Klass* fields in their java.lang.Class instances.
775 if (host_klass == NULL) {
776 THROW_MSG_0(vmSymbols::java_lang_IllegalArgumentException(), "Host class is null");
777 }
778
779 assert(host_klass->is_instance_klass(), "Host class must be an instance class");
780
781 const char* host_source = host_klass->external_name();
782 Handle host_loader(THREAD, host_klass->class_loader());
783 Handle host_domain(THREAD, host_klass->protection_domain());
784
785 GrowableArray<Handle>* cp_patches = NULL;
786
787 if (cp_patches_h.not_null()) {
788 int alen = cp_patches_h->length();
789
790 for (int i = alen-1; i >= 0; i--) {
791 oop p = cp_patches_h->obj_at(i);
792 if (p != NULL) {
793 Handle patch(THREAD, p);
794
795 if (cp_patches == NULL) {
796 cp_patches = new GrowableArray<Handle>(i+1, i+1, Handle());
797 }
798
799 cp_patches->at_put(i, patch);
800 }
801 }
802 }
803
804 ClassFileStream st(class_bytes, class_bytes_length, host_source, ClassFileStream::verify);
805
806 Symbol* no_class_name = NULL;
807 Klass* anonk = SystemDictionary::parse_stream(no_class_name,
808 host_loader,
809 host_domain,
810 &st,
811 InstanceKlass::cast(host_klass),
812 cp_patches,
813 CHECK_NULL);
814 if (anonk == NULL) {
815 return NULL;
816 }
817
818 return InstanceKlass::cast(anonk);
819 }
820
821 UNSAFE_ENTRY(jclass, Unsafe_DefineAnonymousClass0(JNIEnv *env, jobject unsafe, jclass host_class, jbyteArray data, jobjectArray cp_patches_jh)) {
822 ResourceMark rm(THREAD);
823
824 jobject res_jh = NULL;
825 u1* temp_alloc = NULL;
826
827 InstanceKlass* anon_klass = Unsafe_DefineAnonymousClass_impl(env, host_class, data, cp_patches_jh, &temp_alloc, THREAD);
828 if (anon_klass != NULL) {
829 res_jh = JNIHandles::make_local(env, anon_klass->java_mirror());
830 }
831
832 // try/finally clause:
833 if (temp_alloc != NULL) {
834 FREE_C_HEAP_ARRAY(u1, temp_alloc);
835 }
836
837 // The anonymous class loader data has been artificially been kept alive to
838 // this point. The mirror and any instances of this class have to keep
839 // it alive afterwards.
840 if (anon_klass != NULL) {
841 anon_klass->class_loader_data()->dec_keep_alive();
842 }
843
844 // let caller initialize it as needed...
845
846 return (jclass) res_jh;
847 } UNSAFE_END
848
849
850
851 UNSAFE_ENTRY(void, Unsafe_ThrowException(JNIEnv *env, jobject unsafe, jthrowable thr)) {
852 ThreadToNativeFromVM ttnfv(thread);
853 env->Throw(thr);
854 } UNSAFE_END
855
856 // JSR166 ------------------------------------------------------------------
857
858 UNSAFE_ENTRY(jobject, Unsafe_CompareAndExchangeObject(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jobject e_h, jobject x_h)) {
859 oop x = JNIHandles::resolve(x_h);
860 oop e = JNIHandles::resolve(e_h);
861 oop p = JNIHandles::resolve(obj);
862 assert_field_offset_sane(p, offset);
863 oop res = HeapAccess<ON_UNKNOWN_OOP_REF>::oop_atomic_cmpxchg_at(x, p, (ptrdiff_t)offset, e);
864 return JNIHandles::make_local(env, res);
865 } UNSAFE_END
866
867 UNSAFE_ENTRY(jint, Unsafe_CompareAndExchangeInt(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jint e, jint x)) {
868 oop p = JNIHandles::resolve(obj);
869 if (oopDesc::is_null(p)) {
870 volatile jint* addr = (volatile jint*)index_oop_from_field_offset_long(p, offset);
871 return RawAccess<>::atomic_cmpxchg(x, addr, e);
872 } else {
873 assert_field_offset_sane(p, offset);
874 return HeapAccess<>::atomic_cmpxchg_at(x, p, (ptrdiff_t)offset, e);
875 }
876 } UNSAFE_END
877
878 UNSAFE_ENTRY(jlong, Unsafe_CompareAndExchangeLong(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jlong e, jlong x)) {
879 oop p = JNIHandles::resolve(obj);
880 if (oopDesc::is_null(p)) {
881 volatile jlong* addr = (volatile jlong*)index_oop_from_field_offset_long(p, offset);
882 return RawAccess<>::atomic_cmpxchg(x, addr, e);
883 } else {
884 assert_field_offset_sane(p, offset);
885 return HeapAccess<>::atomic_cmpxchg_at(x, p, (ptrdiff_t)offset, e);
886 }
887 } UNSAFE_END
888
889 UNSAFE_ENTRY(jboolean, Unsafe_CompareAndSetObject(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jobject e_h, jobject x_h)) {
890 oop x = JNIHandles::resolve(x_h);
891 oop e = JNIHandles::resolve(e_h);
892 oop p = JNIHandles::resolve(obj);
893 assert_field_offset_sane(p, offset);
894 oop ret = HeapAccess<ON_UNKNOWN_OOP_REF>::oop_atomic_cmpxchg_at(x, p, (ptrdiff_t)offset, e);
895 return ret == e;
896 } UNSAFE_END
897
898 UNSAFE_ENTRY(jboolean, Unsafe_CompareAndSetInt(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jint e, jint x)) {
899 oop p = JNIHandles::resolve(obj);
900 if (oopDesc::is_null(p)) {
901 volatile jint* addr = (volatile jint*)index_oop_from_field_offset_long(p, offset);
902 return RawAccess<>::atomic_cmpxchg(x, addr, e) == e;
903 } else {
904 assert_field_offset_sane(p, offset);
905 return HeapAccess<>::atomic_cmpxchg_at(x, p, (ptrdiff_t)offset, e) == e;
906 }
907 } UNSAFE_END
908
909 UNSAFE_ENTRY(jboolean, Unsafe_CompareAndSetLong(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jlong e, jlong x)) {
910 oop p = JNIHandles::resolve(obj);
911 if (oopDesc::is_null(p)) {
912 volatile jlong* addr = (volatile jlong*)index_oop_from_field_offset_long(p, offset);
913 return RawAccess<>::atomic_cmpxchg(x, addr, e) == e;
914 } else {
915 assert_field_offset_sane(p, offset);
916 return HeapAccess<>::atomic_cmpxchg_at(x, p, (ptrdiff_t)offset, e) == e;
917 }
918 } UNSAFE_END
919
920 UNSAFE_ENTRY(void, Unsafe_Park(JNIEnv *env, jobject unsafe, jboolean isAbsolute, jlong time)) {
921 EventThreadPark event;
922 HOTSPOT_THREAD_PARK_BEGIN((uintptr_t) thread->parker(), (int) isAbsolute, time);
923
924 JavaThreadParkedState jtps(thread, time != 0);
925 thread->parker()->park(isAbsolute != 0, time);
926
927 HOTSPOT_THREAD_PARK_END((uintptr_t) thread->parker());
928
929 if (event.should_commit()) {
930 oop obj = thread->current_park_blocker();
931 event.set_parkedClass((obj != NULL) ? obj->klass() : NULL);
932 event.set_timeout(time);
933 event.set_address((obj != NULL) ? (TYPE_ADDRESS) cast_from_oop<uintptr_t>(obj) : 0);
934 event.commit();
935 }
936 } UNSAFE_END
937
938 UNSAFE_ENTRY(void, Unsafe_Unpark(JNIEnv *env, jobject unsafe, jobject jthread)) {
939 Parker* p = NULL;
940
941 if (jthread != NULL) {
942 ThreadsListHandle tlh;
943 JavaThread* thr = NULL;
944 oop java_thread = NULL;
945 (void) tlh.cv_internal_thread_to_JavaThread(jthread, &thr, &java_thread);
946 if (java_thread != NULL) {
947 // This is a valid oop.
948 jlong lp = java_lang_Thread::park_event(java_thread);
949 if (lp != 0) {
950 // This cast is OK even though the jlong might have been read
951 // non-atomically on 32bit systems, since there, one word will
952 // always be zero anyway and the value set is always the same
953 p = (Parker*)addr_from_java(lp);
954 } else {
955 // Not cached in the java.lang.Thread oop yet (could be an
956 // older version of library).
957 if (thr != NULL) {
958 // The JavaThread is alive.
959 p = thr->parker();
960 if (p != NULL) {
961 // Cache the Parker in the java.lang.Thread oop for next time.
962 java_lang_Thread::set_park_event(java_thread, addr_to_java(p));
963 }
964 }
965 }
966 }
967 } // ThreadsListHandle is destroyed here.
968
969 if (p != NULL) {
970 HOTSPOT_THREAD_UNPARK((uintptr_t) p);
971 p->unpark();
972 }
973 } UNSAFE_END
974
975 UNSAFE_ENTRY(jint, Unsafe_GetLoadAverage0(JNIEnv *env, jobject unsafe, jdoubleArray loadavg, jint nelem)) {
976 const int max_nelem = 3;
977 double la[max_nelem];
978 jint ret;
979
980 typeArrayOop a = typeArrayOop(JNIHandles::resolve_non_null(loadavg));
981 assert(a->is_typeArray(), "must be type array");
982
983 ret = os::loadavg(la, nelem);
984 if (ret == -1) {
985 return -1;
986 }
987
988 // if successful, ret is the number of samples actually retrieved.
989 assert(ret >= 0 && ret <= max_nelem, "Unexpected loadavg return value");
990 switch(ret) {
991 case 3: a->double_at_put(2, (jdouble)la[2]); // fall through
992 case 2: a->double_at_put(1, (jdouble)la[1]); // fall through
993 case 1: a->double_at_put(0, (jdouble)la[0]); break;
994 }
995
996 return ret;
997 } UNSAFE_END
998
999
1000 /// JVM_RegisterUnsafeMethods
1001
1002 #define ADR "J"
1003
1004 #define LANG "Ljava/lang/"
1005
1006 #define OBJ LANG "Object;"
1007 #define CLS LANG "Class;"
1008 #define FLD LANG "reflect/Field;"
1009 #define THR LANG "Throwable;"
1010
1011 #define DC_Args LANG "String;[BII" LANG "ClassLoader;" "Ljava/security/ProtectionDomain;"
1012 #define DAC_Args CLS "[B[" OBJ
1013
1014 #define CC (char*) /*cast a literal from (const char*)*/
1015 #define FN_PTR(f) CAST_FROM_FN_PTR(void*, &f)
1016
1017 #define DECLARE_GETPUTOOP(Type, Desc) \
1018 {CC "get" #Type, CC "(" OBJ "J)" #Desc, FN_PTR(Unsafe_Get##Type)}, \
1019 {CC "put" #Type, CC "(" OBJ "J" #Desc ")V", FN_PTR(Unsafe_Put##Type)}, \
1020 {CC "get" #Type "Volatile", CC "(" OBJ "J)" #Desc, FN_PTR(Unsafe_Get##Type##Volatile)}, \
1021 {CC "put" #Type "Volatile", CC "(" OBJ "J" #Desc ")V", FN_PTR(Unsafe_Put##Type##Volatile)}
1022
1023
1024 static JNINativeMethod jdk_internal_misc_Unsafe_methods[] = {
1025 {CC "getObject", CC "(" OBJ "J)" OBJ "", FN_PTR(Unsafe_GetObject)},
1026 {CC "putObject", CC "(" OBJ "J" OBJ ")V", FN_PTR(Unsafe_PutObject)},
1027 {CC "getObjectVolatile",CC "(" OBJ "J)" OBJ "", FN_PTR(Unsafe_GetObjectVolatile)},
1028 {CC "putObjectVolatile",CC "(" OBJ "J" OBJ ")V", FN_PTR(Unsafe_PutObjectVolatile)},
1029
1030 {CC "getUncompressedObject", CC "(" ADR ")" OBJ, FN_PTR(Unsafe_GetUncompressedObject)},
1031
1032 DECLARE_GETPUTOOP(Boolean, Z),
1033 DECLARE_GETPUTOOP(Byte, B),
1034 DECLARE_GETPUTOOP(Short, S),
1035 DECLARE_GETPUTOOP(Char, C),
1036 DECLARE_GETPUTOOP(Int, I),
1037 DECLARE_GETPUTOOP(Long, J),
1038 DECLARE_GETPUTOOP(Float, F),
1039 DECLARE_GETPUTOOP(Double, D),
1040
1041 {CC "allocateMemory0", CC "(J)" ADR, FN_PTR(Unsafe_AllocateMemory0)},
1042 {CC "reallocateMemory0", CC "(" ADR "J)" ADR, FN_PTR(Unsafe_ReallocateMemory0)},
1043 {CC "freeMemory0", CC "(" ADR ")V", FN_PTR(Unsafe_FreeMemory0)},
1044
1045 {CC "objectFieldOffset0", CC "(" FLD ")J", FN_PTR(Unsafe_ObjectFieldOffset0)},
1046 {CC "objectFieldOffset1", CC "(" CLS LANG "String;)J", FN_PTR(Unsafe_ObjectFieldOffset1)},
1047 {CC "staticFieldOffset0", CC "(" FLD ")J", FN_PTR(Unsafe_StaticFieldOffset0)},
1048 {CC "staticFieldBase0", CC "(" FLD ")" OBJ, FN_PTR(Unsafe_StaticFieldBase0)},
1049 {CC "ensureClassInitialized0", CC "(" CLS ")V", FN_PTR(Unsafe_EnsureClassInitialized0)},
1050 {CC "arrayBaseOffset0", CC "(" CLS ")I", FN_PTR(Unsafe_ArrayBaseOffset0)},
1051 {CC "arrayIndexScale0", CC "(" CLS ")I", FN_PTR(Unsafe_ArrayIndexScale0)},
1052 {CC "addressSize0", CC "()I", FN_PTR(Unsafe_AddressSize0)},
1053 {CC "pageSize", CC "()I", FN_PTR(Unsafe_PageSize)},
1054
1055 {CC "defineClass0", CC "(" DC_Args ")" CLS, FN_PTR(Unsafe_DefineClass0)},
1056 {CC "allocateInstance", CC "(" CLS ")" OBJ, FN_PTR(Unsafe_AllocateInstance)},
1057 {CC "throwException", CC "(" THR ")V", FN_PTR(Unsafe_ThrowException)},
1058 {CC "compareAndSetObject",CC "(" OBJ "J" OBJ "" OBJ ")Z", FN_PTR(Unsafe_CompareAndSetObject)},
1059 {CC "compareAndSetInt", CC "(" OBJ "J""I""I"")Z", FN_PTR(Unsafe_CompareAndSetInt)},
1060 {CC "compareAndSetLong", CC "(" OBJ "J""J""J"")Z", FN_PTR(Unsafe_CompareAndSetLong)},
1061 {CC "compareAndExchangeObject", CC "(" OBJ "J" OBJ "" OBJ ")" OBJ, FN_PTR(Unsafe_CompareAndExchangeObject)},
1062 {CC "compareAndExchangeInt", CC "(" OBJ "J""I""I"")I", FN_PTR(Unsafe_CompareAndExchangeInt)},
1063 {CC "compareAndExchangeLong", CC "(" OBJ "J""J""J"")J", FN_PTR(Unsafe_CompareAndExchangeLong)},
1064
1065 {CC "park", CC "(ZJ)V", FN_PTR(Unsafe_Park)},
1066 {CC "unpark", CC "(" OBJ ")V", FN_PTR(Unsafe_Unpark)},
1067
1068 {CC "getLoadAverage0", CC "([DI)I", FN_PTR(Unsafe_GetLoadAverage0)},
1069
1070 {CC "copyMemory0", CC "(" OBJ "J" OBJ "JJ)V", FN_PTR(Unsafe_CopyMemory0)},
1071 {CC "copySwapMemory0", CC "(" OBJ "J" OBJ "JJJ)V", FN_PTR(Unsafe_CopySwapMemory0)},
1072 {CC "setMemory0", CC "(" OBJ "JJB)V", FN_PTR(Unsafe_SetMemory0)},
1073
1074 {CC "defineAnonymousClass0", CC "(" DAC_Args ")" CLS, FN_PTR(Unsafe_DefineAnonymousClass0)},
1075
1076 {CC "shouldBeInitialized0", CC "(" CLS ")Z", FN_PTR(Unsafe_ShouldBeInitialized0)},
1077
1078 {CC "loadFence", CC "()V", FN_PTR(Unsafe_LoadFence)},
1079 {CC "storeFence", CC "()V", FN_PTR(Unsafe_StoreFence)},
1080 {CC "fullFence", CC "()V", FN_PTR(Unsafe_FullFence)},
1081
1082 {CC "isBigEndian0", CC "()Z", FN_PTR(Unsafe_isBigEndian0)},
1083 {CC "unalignedAccess0", CC "()Z", FN_PTR(Unsafe_unalignedAccess0)}
1084 };
1085
1086 #undef CC
1087 #undef FN_PTR
1088
1089 #undef ADR
1090 #undef LANG
1091 #undef OBJ
1092 #undef CLS
1093 #undef FLD
1094 #undef THR
1095 #undef DC_Args
1096 #undef DAC_Args
1097
1098 #undef DECLARE_GETPUTOOP
1099
1100
1101 // This function is exported, used by NativeLookup.
1102 // The Unsafe_xxx functions above are called only from the interpreter.
1103 // The optimizer looks at names and signatures to recognize
1104 // individual functions.
1105
1106 JVM_ENTRY(void, JVM_RegisterJDKInternalMiscUnsafeMethods(JNIEnv *env, jclass unsafeclass)) {
1107 ThreadToNativeFromVM ttnfv(thread);
1108
1109 int ok = env->RegisterNatives(unsafeclass, jdk_internal_misc_Unsafe_methods, sizeof(jdk_internal_misc_Unsafe_methods)/sizeof(JNINativeMethod));
1110 guarantee(ok == 0, "register jdk.internal.misc.Unsafe natives");
1111 } JVM_END