1 /*
2 * Copyright (c) 2000, 2019, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "precompiled.hpp"
26 #include "jni.h"
27 #include "jvm.h"
28 #include "classfile/classFileStream.hpp"
29 #include "classfile/vmSymbols.hpp"
30 #include "jfr/jfrEvents.hpp"
31 #include "memory/allocation.inline.hpp"
32 #include "memory/resourceArea.hpp"
33 #include "oops/access.inline.hpp"
34 #include "oops/fieldStreams.hpp"
35 #include "oops/objArrayOop.inline.hpp"
36 #include "oops/oop.inline.hpp"
37 #include "oops/typeArrayOop.inline.hpp"
38 #include "prims/unsafe.hpp"
39 #include "runtime/atomic.hpp"
40 #include "runtime/globals.hpp"
41 #include "runtime/handles.inline.hpp"
42 #include "runtime/interfaceSupport.inline.hpp"
43 #include "runtime/jniHandles.inline.hpp"
44 #include "runtime/orderAccess.hpp"
45 #include "runtime/reflection.hpp"
46 #include "runtime/thread.hpp"
47 #include "runtime/threadSMR.hpp"
48 #include "runtime/vm_version.hpp"
49 #include "services/threadService.hpp"
50 #include "utilities/align.hpp"
51 #include "utilities/copy.hpp"
52 #include "utilities/dtrace.hpp"
53 #include "utilities/macros.hpp"
54
55 /**
56 * Implementation of the jdk.internal.misc.Unsafe class
57 */
58
59
60 #define MAX_OBJECT_SIZE \
61 ( arrayOopDesc::header_size(T_DOUBLE) * HeapWordSize \
62 + ((julong)max_jint * sizeof(double)) )
63
64
65 #define UNSAFE_ENTRY(result_type, header) \
66 JVM_ENTRY(static result_type, header)
67
68 #define UNSAFE_LEAF(result_type, header) \
69 JVM_LEAF(static result_type, header)
70
71 #define UNSAFE_END JVM_END
72
73
74 static inline void* addr_from_java(jlong addr) {
75 // This assert fails in a variety of ways on 32-bit systems.
76 // It is impossible to predict whether native code that converts
77 // pointers to longs will sign-extend or zero-extend the addresses.
78 //assert(addr == (uintptr_t)addr, "must not be odd high bits");
79 return (void*)(uintptr_t)addr;
80 }
81
82 static inline jlong addr_to_java(void* p) {
83 assert(p == (void*)(uintptr_t)p, "must not be odd high bits");
84 return (uintptr_t)p;
85 }
86
87
88 // Note: The VM's obj_field and related accessors use byte-scaled
89 // ("unscaled") offsets, just as the unsafe methods do.
90
91 // However, the method Unsafe.fieldOffset explicitly declines to
92 // guarantee this. The field offset values manipulated by the Java user
93 // through the Unsafe API are opaque cookies that just happen to be byte
94 // offsets. We represent this state of affairs by passing the cookies
95 // through conversion functions when going between the VM and the Unsafe API.
96 // The conversion functions just happen to be no-ops at present.
97
98 static inline jlong field_offset_to_byte_offset(jlong field_offset) {
99 return field_offset;
100 }
101
102 static inline jlong field_offset_from_byte_offset(jlong byte_offset) {
103 return byte_offset;
104 }
105
106 static inline void assert_field_offset_sane(oop p, jlong field_offset) {
107 #ifdef ASSERT
108 jlong byte_offset = field_offset_to_byte_offset(field_offset);
109
110 if (p != NULL) {
111 assert(byte_offset >= 0 && byte_offset <= (jlong)MAX_OBJECT_SIZE, "sane offset");
112 if (byte_offset == (jint)byte_offset) {
113 void* ptr_plus_disp = (address)p + byte_offset;
114 assert(p->field_addr_raw((jint)byte_offset) == ptr_plus_disp,
115 "raw [ptr+disp] must be consistent with oop::field_addr_raw");
116 }
117 jlong p_size = HeapWordSize * (jlong)(p->size());
118 assert(byte_offset < p_size, "Unsafe access: offset " INT64_FORMAT " > object's size " INT64_FORMAT, (int64_t)byte_offset, (int64_t)p_size);
119 }
120 #endif
121 }
122
123 static inline void* index_oop_from_field_offset_long(oop p, jlong field_offset) {
124 assert_field_offset_sane(p, field_offset);
125 jlong byte_offset = field_offset_to_byte_offset(field_offset);
126
127 if (p != NULL) {
128 p = Access<>::resolve(p);
129 }
130
131 if (sizeof(char*) == sizeof(jint)) { // (this constant folds!)
132 return (address)p + (jint) byte_offset;
133 } else {
134 return (address)p + byte_offset;
135 }
136 }
137
138 // Externally callable versions:
139 // (Use these in compiler intrinsics which emulate unsafe primitives.)
140 jlong Unsafe_field_offset_to_byte_offset(jlong field_offset) {
141 return field_offset;
142 }
143 jlong Unsafe_field_offset_from_byte_offset(jlong byte_offset) {
144 return byte_offset;
145 }
146
147
148 ///// Data read/writes on the Java heap and in native (off-heap) memory
149
150 /**
151 * Helper class for accessing memory.
152 *
153 * Normalizes values and wraps accesses in
154 * JavaThread::doing_unsafe_access() if needed.
155 */
156 template <typename T>
157 class MemoryAccess : StackObj {
158 JavaThread* _thread;
159 oop _obj;
160 ptrdiff_t _offset;
161
162 // Resolves and returns the address of the memory access.
163 // This raw memory access may fault, so we make sure it happens within the
164 // guarded scope by making the access volatile at least. Since the store
165 // of Thread::set_doing_unsafe_access() is also volatile, these accesses
166 // can not be reordered by the compiler. Therefore, if the access triggers
167 // a fault, we will know that Thread::doing_unsafe_access() returns true.
168 volatile T* addr() {
169 void* addr = index_oop_from_field_offset_long(_obj, _offset);
170 return static_cast<volatile T*>(addr);
171 }
172
173 template <typename U>
174 U normalize_for_write(U x) {
175 return x;
176 }
177
178 jboolean normalize_for_write(jboolean x) {
179 return x & 1;
180 }
181
182 template <typename U>
183 U normalize_for_read(U x) {
184 return x;
185 }
186
187 jboolean normalize_for_read(jboolean x) {
188 return x != 0;
189 }
190
191 /**
192 * Helper class to wrap memory accesses in JavaThread::doing_unsafe_access()
193 */
194 class GuardUnsafeAccess {
195 JavaThread* _thread;
196
197 public:
198 GuardUnsafeAccess(JavaThread* thread) : _thread(thread) {
199 // native/off-heap access which may raise SIGBUS if accessing
200 // memory mapped file data in a region of the file which has
201 // been truncated and is now invalid
202 _thread->set_doing_unsafe_access(true);
203 }
204
205 ~GuardUnsafeAccess() {
206 _thread->set_doing_unsafe_access(false);
207 }
208 };
209
210 public:
211 MemoryAccess(JavaThread* thread, jobject obj, jlong offset)
212 : _thread(thread), _obj(JNIHandles::resolve(obj)), _offset((ptrdiff_t)offset) {
213 assert_field_offset_sane(_obj, offset);
214 }
215
216 T get() {
217 if (_obj == NULL) {
218 GuardUnsafeAccess guard(_thread);
219 T ret = RawAccess<>::load(addr());
220 return normalize_for_read(ret);
221 } else {
222 T ret = HeapAccess<>::load_at(_obj, _offset);
223 return normalize_for_read(ret);
224 }
225 }
226
227 void put(T x) {
228 if (_obj == NULL) {
229 GuardUnsafeAccess guard(_thread);
230 RawAccess<>::store(addr(), normalize_for_write(x));
231 } else {
232 HeapAccess<>::store_at(_obj, _offset, normalize_for_write(x));
233 }
234 }
235
236
237 T get_volatile() {
238 if (_obj == NULL) {
239 GuardUnsafeAccess guard(_thread);
240 volatile T ret = RawAccess<MO_SEQ_CST>::load(addr());
241 return normalize_for_read(ret);
242 } else {
243 T ret = HeapAccess<MO_SEQ_CST>::load_at(_obj, _offset);
244 return normalize_for_read(ret);
245 }
246 }
247
248 void put_volatile(T x) {
249 if (_obj == NULL) {
250 GuardUnsafeAccess guard(_thread);
251 RawAccess<MO_SEQ_CST>::store(addr(), normalize_for_write(x));
252 } else {
253 HeapAccess<MO_SEQ_CST>::store_at(_obj, _offset, normalize_for_write(x));
254 }
255 }
256 };
257
258 // These functions allow a null base pointer with an arbitrary address.
259 // But if the base pointer is non-null, the offset should make some sense.
260 // That is, it should be in the range [0, MAX_OBJECT_SIZE].
261 UNSAFE_ENTRY(jobject, Unsafe_GetReference(JNIEnv *env, jobject unsafe, jobject obj, jlong offset)) {
262 oop p = JNIHandles::resolve(obj);
263 assert_field_offset_sane(p, offset);
264 oop v = HeapAccess<ON_UNKNOWN_OOP_REF>::oop_load_at(p, offset);
265 return JNIHandles::make_local(env, v);
266 } UNSAFE_END
267
268 UNSAFE_ENTRY(void, Unsafe_PutReference(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jobject x_h)) {
269 oop x = JNIHandles::resolve(x_h);
270 oop p = JNIHandles::resolve(obj);
271 assert_field_offset_sane(p, offset);
272 HeapAccess<ON_UNKNOWN_OOP_REF>::oop_store_at(p, offset, x);
273 } UNSAFE_END
274
275 UNSAFE_ENTRY(jobject, Unsafe_GetReferenceVolatile(JNIEnv *env, jobject unsafe, jobject obj, jlong offset)) {
276 oop p = JNIHandles::resolve(obj);
277 assert_field_offset_sane(p, offset);
278 oop v = HeapAccess<MO_SEQ_CST | ON_UNKNOWN_OOP_REF>::oop_load_at(p, offset);
279 return JNIHandles::make_local(env, v);
280 } UNSAFE_END
281
282 UNSAFE_ENTRY(void, Unsafe_PutReferenceVolatile(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jobject x_h)) {
283 oop x = JNIHandles::resolve(x_h);
284 oop p = JNIHandles::resolve(obj);
285 assert_field_offset_sane(p, offset);
286 HeapAccess<MO_SEQ_CST | ON_UNKNOWN_OOP_REF>::oop_store_at(p, offset, x);
287 } UNSAFE_END
288
289 UNSAFE_ENTRY(jobject, Unsafe_GetUncompressedObject(JNIEnv *env, jobject unsafe, jlong addr)) {
290 oop v = *(oop*) (address) addr;
291 return JNIHandles::make_local(env, v);
292 } UNSAFE_END
293
294 UNSAFE_LEAF(jboolean, Unsafe_isBigEndian0(JNIEnv *env, jobject unsafe)) {
295 #ifdef VM_LITTLE_ENDIAN
296 return false;
297 #else
298 return true;
299 #endif
300 } UNSAFE_END
301
302 UNSAFE_LEAF(jint, Unsafe_unalignedAccess0(JNIEnv *env, jobject unsafe)) {
303 return UseUnalignedAccesses;
304 } UNSAFE_END
305
306 #define DEFINE_GETSETOOP(java_type, Type) \
307 \
308 UNSAFE_ENTRY(java_type, Unsafe_Get##Type(JNIEnv *env, jobject unsafe, jobject obj, jlong offset)) { \
309 return MemoryAccess<java_type>(thread, obj, offset).get(); \
310 } UNSAFE_END \
311 \
312 UNSAFE_ENTRY(void, Unsafe_Put##Type(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, java_type x)) { \
313 MemoryAccess<java_type>(thread, obj, offset).put(x); \
314 } UNSAFE_END \
315 \
316 // END DEFINE_GETSETOOP.
317
318 DEFINE_GETSETOOP(jboolean, Boolean)
319 DEFINE_GETSETOOP(jbyte, Byte)
320 DEFINE_GETSETOOP(jshort, Short);
321 DEFINE_GETSETOOP(jchar, Char);
322 DEFINE_GETSETOOP(jint, Int);
323 DEFINE_GETSETOOP(jlong, Long);
324 DEFINE_GETSETOOP(jfloat, Float);
325 DEFINE_GETSETOOP(jdouble, Double);
326
327 #undef DEFINE_GETSETOOP
328
329 #define DEFINE_GETSETOOP_VOLATILE(java_type, Type) \
330 \
331 UNSAFE_ENTRY(java_type, Unsafe_Get##Type##Volatile(JNIEnv *env, jobject unsafe, jobject obj, jlong offset)) { \
332 return MemoryAccess<java_type>(thread, obj, offset).get_volatile(); \
333 } UNSAFE_END \
334 \
335 UNSAFE_ENTRY(void, Unsafe_Put##Type##Volatile(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, java_type x)) { \
336 MemoryAccess<java_type>(thread, obj, offset).put_volatile(x); \
337 } UNSAFE_END \
338 \
339 // END DEFINE_GETSETOOP_VOLATILE.
340
341 DEFINE_GETSETOOP_VOLATILE(jboolean, Boolean)
342 DEFINE_GETSETOOP_VOLATILE(jbyte, Byte)
343 DEFINE_GETSETOOP_VOLATILE(jshort, Short);
344 DEFINE_GETSETOOP_VOLATILE(jchar, Char);
345 DEFINE_GETSETOOP_VOLATILE(jint, Int);
346 DEFINE_GETSETOOP_VOLATILE(jlong, Long);
347 DEFINE_GETSETOOP_VOLATILE(jfloat, Float);
348 DEFINE_GETSETOOP_VOLATILE(jdouble, Double);
349
350 #undef DEFINE_GETSETOOP_VOLATILE
351
352 UNSAFE_LEAF(void, Unsafe_LoadFence(JNIEnv *env, jobject unsafe)) {
353 OrderAccess::acquire();
354 } UNSAFE_END
355
356 UNSAFE_LEAF(void, Unsafe_StoreFence(JNIEnv *env, jobject unsafe)) {
357 OrderAccess::release();
358 } UNSAFE_END
359
360 UNSAFE_LEAF(void, Unsafe_FullFence(JNIEnv *env, jobject unsafe)) {
361 OrderAccess::fence();
362 } UNSAFE_END
363
364 ////// Allocation requests
365
366 UNSAFE_ENTRY(jobject, Unsafe_AllocateInstance(JNIEnv *env, jobject unsafe, jclass cls)) {
367 ThreadToNativeFromVM ttnfv(thread);
368 return env->AllocObject(cls);
369 } UNSAFE_END
370
371 UNSAFE_ENTRY(jlong, Unsafe_AllocateMemory0(JNIEnv *env, jobject unsafe, jlong size)) {
372 size_t sz = (size_t)size;
373
374 sz = align_up(sz, HeapWordSize);
375 void* x = os::malloc(sz, mtOther);
376
377 return addr_to_java(x);
378 } UNSAFE_END
379
380 UNSAFE_ENTRY(jlong, Unsafe_ReallocateMemory0(JNIEnv *env, jobject unsafe, jlong addr, jlong size)) {
381 void* p = addr_from_java(addr);
382 size_t sz = (size_t)size;
383 sz = align_up(sz, HeapWordSize);
384
385 void* x = os::realloc(p, sz, mtOther);
386
387 return addr_to_java(x);
388 } UNSAFE_END
389
390 UNSAFE_ENTRY(void, Unsafe_FreeMemory0(JNIEnv *env, jobject unsafe, jlong addr)) {
391 void* p = addr_from_java(addr);
392
393 os::free(p);
394 } UNSAFE_END
395
396 UNSAFE_ENTRY(void, Unsafe_SetMemory0(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jlong size, jbyte value)) {
397 size_t sz = (size_t)size;
398
399 oop base = JNIHandles::resolve(obj);
400 void* p = index_oop_from_field_offset_long(base, offset);
401
402 Copy::fill_to_memory_atomic(p, sz, value);
403 } UNSAFE_END
404
405 UNSAFE_ENTRY(void, Unsafe_CopyMemory0(JNIEnv *env, jobject unsafe, jobject srcObj, jlong srcOffset, jobject dstObj, jlong dstOffset, jlong size)) {
406 size_t sz = (size_t)size;
407
408 oop srcp = JNIHandles::resolve(srcObj);
409 oop dstp = JNIHandles::resolve(dstObj);
410
411 void* src = index_oop_from_field_offset_long(srcp, srcOffset);
412 void* dst = index_oop_from_field_offset_long(dstp, dstOffset);
413
414 Copy::conjoint_memory_atomic(src, dst, sz);
415 } UNSAFE_END
416
417 // This function is a leaf since if the source and destination are both in native memory
418 // the copy may potentially be very large, and we don't want to disable GC if we can avoid it.
419 // If either source or destination (or both) are on the heap, the function will enter VM using
420 // JVM_ENTRY_FROM_LEAF
421 UNSAFE_LEAF(void, Unsafe_CopySwapMemory0(JNIEnv *env, jobject unsafe, jobject srcObj, jlong srcOffset, jobject dstObj, jlong dstOffset, jlong size, jlong elemSize)) {
422 size_t sz = (size_t)size;
423 size_t esz = (size_t)elemSize;
424
425 if (srcObj == NULL && dstObj == NULL) {
426 // Both src & dst are in native memory
427 address src = (address)srcOffset;
428 address dst = (address)dstOffset;
429
430 Copy::conjoint_swap(src, dst, sz, esz);
431 } else {
432 // At least one of src/dst are on heap, transition to VM to access raw pointers
433
434 JVM_ENTRY_FROM_LEAF(env, void, Unsafe_CopySwapMemory0) {
435 oop srcp = JNIHandles::resolve(srcObj);
436 oop dstp = JNIHandles::resolve(dstObj);
437
438 address src = (address)index_oop_from_field_offset_long(srcp, srcOffset);
439 address dst = (address)index_oop_from_field_offset_long(dstp, dstOffset);
440
441 Copy::conjoint_swap(src, dst, sz, esz);
442 } JVM_END
443 }
444 } UNSAFE_END
445
446 ////// Random queries
447
448 UNSAFE_LEAF(jint, Unsafe_AddressSize0(JNIEnv *env, jobject unsafe)) {
449 return sizeof(void*);
450 } UNSAFE_END
451
452 UNSAFE_LEAF(jint, Unsafe_PageSize()) {
453 return os::vm_page_size();
454 } UNSAFE_END
455
456 static jlong find_field_offset(jclass clazz, jstring name, TRAPS) {
457 assert(clazz != NULL, "clazz must not be NULL");
458 assert(name != NULL, "name must not be NULL");
459
460 ResourceMark rm(THREAD);
461 char *utf_name = java_lang_String::as_utf8_string(JNIHandles::resolve_non_null(name));
462
463 InstanceKlass* k = InstanceKlass::cast(java_lang_Class::as_Klass(JNIHandles::resolve_non_null(clazz)));
464
465 jint offset = -1;
466 for (JavaFieldStream fs(k); !fs.done(); fs.next()) {
467 Symbol *name = fs.name();
468 if (name->equals(utf_name)) {
469 offset = fs.offset();
470 break;
471 }
472 }
473 if (offset < 0) {
474 THROW_0(vmSymbols::java_lang_InternalError());
475 }
476 return field_offset_from_byte_offset(offset);
477 }
478
479 static jlong find_field_offset(jobject field, int must_be_static, TRAPS) {
480 assert(field != NULL, "field must not be NULL");
481
482 oop reflected = JNIHandles::resolve_non_null(field);
483 oop mirror = java_lang_reflect_Field::clazz(reflected);
484 Klass* k = java_lang_Class::as_Klass(mirror);
485 int slot = java_lang_reflect_Field::slot(reflected);
486 int modifiers = java_lang_reflect_Field::modifiers(reflected);
487
488 if (must_be_static >= 0) {
489 int really_is_static = ((modifiers & JVM_ACC_STATIC) != 0);
490 if (must_be_static != really_is_static) {
491 THROW_0(vmSymbols::java_lang_IllegalArgumentException());
492 }
493 }
494
495 int offset = InstanceKlass::cast(k)->field_offset(slot);
496 return field_offset_from_byte_offset(offset);
497 }
498
499 UNSAFE_ENTRY(jlong, Unsafe_ObjectFieldOffset0(JNIEnv *env, jobject unsafe, jobject field)) {
500 return find_field_offset(field, 0, THREAD);
501 } UNSAFE_END
502
503 UNSAFE_ENTRY(jlong, Unsafe_ObjectFieldOffset1(JNIEnv *env, jobject unsafe, jclass c, jstring name)) {
504 return find_field_offset(c, name, THREAD);
505 } UNSAFE_END
506
507 UNSAFE_ENTRY(jlong, Unsafe_StaticFieldOffset0(JNIEnv *env, jobject unsafe, jobject field)) {
508 return find_field_offset(field, 1, THREAD);
509 } UNSAFE_END
510
511 UNSAFE_ENTRY(jobject, Unsafe_StaticFieldBase0(JNIEnv *env, jobject unsafe, jobject field)) {
512 assert(field != NULL, "field must not be NULL");
513
514 // Note: In this VM implementation, a field address is always a short
515 // offset from the base of a a klass metaobject. Thus, the full dynamic
516 // range of the return type is never used. However, some implementations
517 // might put the static field inside an array shared by many classes,
518 // or even at a fixed address, in which case the address could be quite
519 // large. In that last case, this function would return NULL, since
520 // the address would operate alone, without any base pointer.
521
522 oop reflected = JNIHandles::resolve_non_null(field);
523 oop mirror = java_lang_reflect_Field::clazz(reflected);
524 int modifiers = java_lang_reflect_Field::modifiers(reflected);
525
526 if ((modifiers & JVM_ACC_STATIC) == 0) {
527 THROW_0(vmSymbols::java_lang_IllegalArgumentException());
528 }
529
530 return JNIHandles::make_local(env, mirror);
531 } UNSAFE_END
532
533 UNSAFE_ENTRY(void, Unsafe_EnsureClassInitialized0(JNIEnv *env, jobject unsafe, jobject clazz)) {
534 assert(clazz != NULL, "clazz must not be NULL");
535
536 oop mirror = JNIHandles::resolve_non_null(clazz);
537
538 Klass* klass = java_lang_Class::as_Klass(mirror);
539 if (klass != NULL && klass->should_be_initialized()) {
540 InstanceKlass* k = InstanceKlass::cast(klass);
541 k->initialize(CHECK);
542 }
543 }
544 UNSAFE_END
545
546 UNSAFE_ENTRY(jboolean, Unsafe_ShouldBeInitialized0(JNIEnv *env, jobject unsafe, jobject clazz)) {
547 assert(clazz != NULL, "clazz must not be NULL");
548
549 oop mirror = JNIHandles::resolve_non_null(clazz);
550 Klass* klass = java_lang_Class::as_Klass(mirror);
551
552 if (klass != NULL && klass->should_be_initialized()) {
553 return true;
554 }
555
556 return false;
557 }
558 UNSAFE_END
559
560 static void getBaseAndScale(int& base, int& scale, jclass clazz, TRAPS) {
561 assert(clazz != NULL, "clazz must not be NULL");
562
563 oop mirror = JNIHandles::resolve_non_null(clazz);
564 Klass* k = java_lang_Class::as_Klass(mirror);
565
566 if (k == NULL || !k->is_array_klass()) {
567 THROW(vmSymbols::java_lang_InvalidClassException());
568 } else if (k->is_objArray_klass()) {
569 base = arrayOopDesc::base_offset_in_bytes(T_OBJECT);
570 scale = heapOopSize;
571 } else if (k->is_typeArray_klass()) {
572 TypeArrayKlass* tak = TypeArrayKlass::cast(k);
573 base = tak->array_header_in_bytes();
574 assert(base == arrayOopDesc::base_offset_in_bytes(tak->element_type()), "array_header_size semantics ok");
575 scale = (1 << tak->log2_element_size());
576 } else {
577 ShouldNotReachHere();
578 }
579 }
580
581 UNSAFE_ENTRY(jint, Unsafe_ArrayBaseOffset0(JNIEnv *env, jobject unsafe, jclass clazz)) {
582 int base = 0, scale = 0;
583 getBaseAndScale(base, scale, clazz, CHECK_0);
584
585 return field_offset_from_byte_offset(base);
586 } UNSAFE_END
587
588
589 UNSAFE_ENTRY(jint, Unsafe_ArrayIndexScale0(JNIEnv *env, jobject unsafe, jclass clazz)) {
590 int base = 0, scale = 0;
591 getBaseAndScale(base, scale, clazz, CHECK_0);
592
593 // This VM packs both fields and array elements down to the byte.
594 // But watch out: If this changes, so that array references for
595 // a given primitive type (say, T_BOOLEAN) use different memory units
596 // than fields, this method MUST return zero for such arrays.
597 // For example, the VM used to store sub-word sized fields in full
598 // words in the object layout, so that accessors like getByte(Object,int)
599 // did not really do what one might expect for arrays. Therefore,
600 // this function used to report a zero scale factor, so that the user
601 // would know not to attempt to access sub-word array elements.
602 // // Code for unpacked fields:
603 // if (scale < wordSize) return 0;
604
605 // The following allows for a pretty general fieldOffset cookie scheme,
606 // but requires it to be linear in byte offset.
607 return field_offset_from_byte_offset(scale) - field_offset_from_byte_offset(0);
608 } UNSAFE_END
609
610
611 static inline void throw_new(JNIEnv *env, const char *ename) {
612 jclass cls = env->FindClass(ename);
613 if (env->ExceptionCheck()) {
614 env->ExceptionClear();
615 tty->print_cr("Unsafe: cannot throw %s because FindClass has failed", ename);
616 return;
617 }
618
619 env->ThrowNew(cls, NULL);
620 }
621
622 static jclass Unsafe_DefineClass_impl(JNIEnv *env, jstring name, jbyteArray data, int offset, int length, jobject loader, jobject pd) {
623 // Code lifted from JDK 1.3 ClassLoader.c
624
625 jbyte *body;
626 char *utfName = NULL;
627 jclass result = 0;
628 char buf[128];
629
630 assert(data != NULL, "Class bytes must not be NULL");
631 assert(length >= 0, "length must not be negative: %d", length);
632
633 if (UsePerfData) {
634 ClassLoader::unsafe_defineClassCallCounter()->inc();
635 }
636
637 body = NEW_C_HEAP_ARRAY(jbyte, length, mtInternal);
638 if (body == NULL) {
639 throw_new(env, "java/lang/OutOfMemoryError");
640 return 0;
641 }
642
643 env->GetByteArrayRegion(data, offset, length, body);
644 if (env->ExceptionOccurred()) {
645 goto free_body;
646 }
647
648 if (name != NULL) {
649 uint len = env->GetStringUTFLength(name);
650 int unicode_len = env->GetStringLength(name);
651
652 if (len >= sizeof(buf)) {
653 utfName = NEW_C_HEAP_ARRAY(char, len + 1, mtInternal);
654 if (utfName == NULL) {
655 throw_new(env, "java/lang/OutOfMemoryError");
656 goto free_body;
657 }
658 } else {
659 utfName = buf;
660 }
661
662 env->GetStringUTFRegion(name, 0, unicode_len, utfName);
663
664 for (uint i = 0; i < len; i++) {
665 if (utfName[i] == '.') utfName[i] = '/';
666 }
667 }
668
669 result = JVM_DefineClass(env, utfName, loader, body, length, pd);
670
671 if (utfName && utfName != buf) {
672 FREE_C_HEAP_ARRAY(char, utfName);
673 }
674
675 free_body:
676 FREE_C_HEAP_ARRAY(jbyte, body);
677 return result;
678 }
679
680
681 UNSAFE_ENTRY(jclass, Unsafe_DefineClass0(JNIEnv *env, jobject unsafe, jstring name, jbyteArray data, int offset, int length, jobject loader, jobject pd)) {
682 ThreadToNativeFromVM ttnfv(thread);
683
684 return Unsafe_DefineClass_impl(env, name, data, offset, length, loader, pd);
685 } UNSAFE_END
686
687
688 // define a class but do not make it known to the class loader or system dictionary
689 // - host_class: supplies context for linkage, access control, protection domain, and class loader
690 // if host_class is itself anonymous then it is replaced with its host class.
691 // - data: bytes of a class file, a raw memory address (length gives the number of bytes)
692 // - cp_patches: where non-null entries exist, they replace corresponding CP entries in data
693
694 // When you load an anonymous class U, it works as if you changed its name just before loading,
695 // to a name that you will never use again. Since the name is lost, no other class can directly
696 // link to any member of U. Just after U is loaded, the only way to use it is reflectively,
697 // through java.lang.Class methods like Class.newInstance.
698
699 // The package of an anonymous class must either match its host's class's package or be in the
700 // unnamed package. If it is in the unnamed package then it will be put in its host class's
701 // package.
702 //
703
704 // Access checks for linkage sites within U continue to follow the same rules as for named classes.
705 // An anonymous class also has special privileges to access any member of its host class.
706 // This is the main reason why this loading operation is unsafe. The purpose of this is to
707 // allow language implementations to simulate "open classes"; a host class in effect gets
708 // new code when an anonymous class is loaded alongside it. A less convenient but more
709 // standard way to do this is with reflection, which can also be set to ignore access
710 // restrictions.
711
712 // Access into an anonymous class is possible only through reflection. Therefore, there
713 // are no special access rules for calling into an anonymous class. The relaxed access
714 // rule for the host class is applied in the opposite direction: A host class reflectively
715 // access one of its anonymous classes.
716
717 // If you load the same bytecodes twice, you get two different classes. You can reload
718 // the same bytecodes with or without varying CP patches.
719
720 // By using the CP patching array, you can have a new anonymous class U2 refer to an older one U1.
721 // The bytecodes for U2 should refer to U1 by a symbolic name (doesn't matter what the name is).
722 // The CONSTANT_Class entry for that name can be patched to refer directly to U1.
723
724 // This allows, for example, U2 to use U1 as a superclass or super-interface, or as
725 // an outer class (so that U2 is an anonymous inner class of anonymous U1).
726 // It is not possible for a named class, or an older anonymous class, to refer by
727 // name (via its CP) to a newer anonymous class.
728
729 // CP patching may also be used to modify (i.e., hack) the names of methods, classes,
730 // or type descriptors used in the loaded anonymous class.
731
732 // Finally, CP patching may be used to introduce "live" objects into the constant pool,
733 // instead of "dead" strings. A compiled statement like println((Object)"hello") can
734 // be changed to println(greeting), where greeting is an arbitrary object created before
735 // the anonymous class is loaded. This is useful in dynamic languages, in which
736 // various kinds of metaobjects must be introduced as constants into bytecode.
737 // Note the cast (Object), which tells the verifier to expect an arbitrary object,
738 // not just a literal string. For such ldc instructions, the verifier uses the
739 // type Object instead of String, if the loaded constant is not in fact a String.
740
741 static InstanceKlass*
742 Unsafe_DefineAnonymousClass_impl(JNIEnv *env,
743 jclass host_class, jbyteArray data, jobjectArray cp_patches_jh,
744 u1** temp_alloc,
745 TRAPS) {
746 assert(host_class != NULL, "host_class must not be NULL");
747 assert(data != NULL, "data must not be NULL");
748
749 if (UsePerfData) {
750 ClassLoader::unsafe_defineClassCallCounter()->inc();
751 }
752
753 jint length = typeArrayOop(JNIHandles::resolve_non_null(data))->length();
754 assert(length >= 0, "class_bytes_length must not be negative: %d", length);
755
756 int class_bytes_length = (int) length;
757
758 u1* class_bytes = NEW_C_HEAP_ARRAY(u1, length, mtInternal);
759 if (class_bytes == NULL) {
760 THROW_0(vmSymbols::java_lang_OutOfMemoryError());
761 }
762
763 // caller responsible to free it:
764 *temp_alloc = class_bytes;
765
766 ArrayAccess<>::arraycopy_to_native(arrayOop(JNIHandles::resolve_non_null(data)), typeArrayOopDesc::element_offset<jbyte>(0),
767 reinterpret_cast<jbyte*>(class_bytes), length);
768
769 objArrayHandle cp_patches_h;
770 if (cp_patches_jh != NULL) {
771 oop p = JNIHandles::resolve_non_null(cp_patches_jh);
772 assert(p->is_objArray(), "cp_patches must be an object[]");
773 cp_patches_h = objArrayHandle(THREAD, (objArrayOop)p);
774 }
775
776 const Klass* host_klass = java_lang_Class::as_Klass(JNIHandles::resolve_non_null(host_class));
777
778 // Make sure it's the real host class, not another anonymous class.
779 while (host_klass != NULL && host_klass->is_instance_klass() &&
780 InstanceKlass::cast(host_klass)->is_unsafe_anonymous()) {
781 host_klass = InstanceKlass::cast(host_klass)->unsafe_anonymous_host();
782 }
783
784 // Primitive types have NULL Klass* fields in their java.lang.Class instances.
785 if (host_klass == NULL) {
786 THROW_MSG_0(vmSymbols::java_lang_IllegalArgumentException(), "Host class is null");
787 }
788
789 assert(host_klass->is_instance_klass(), "Host class must be an instance class");
790
791 const char* host_source = host_klass->external_name();
792 Handle host_loader(THREAD, host_klass->class_loader());
793 Handle host_domain(THREAD, host_klass->protection_domain());
794
795 GrowableArray<Handle>* cp_patches = NULL;
796
797 if (cp_patches_h.not_null()) {
798 int alen = cp_patches_h->length();
799
800 for (int i = alen-1; i >= 0; i--) {
801 oop p = cp_patches_h->obj_at(i);
802 if (p != NULL) {
803 Handle patch(THREAD, p);
804
805 if (cp_patches == NULL) {
806 cp_patches = new GrowableArray<Handle>(i+1, i+1, Handle());
807 }
808
809 cp_patches->at_put(i, patch);
810 }
811 }
812 }
813
814 ClassFileStream st(class_bytes, class_bytes_length, host_source, ClassFileStream::verify);
815
816 Symbol* no_class_name = NULL;
817 Klass* anonk = SystemDictionary::parse_stream(no_class_name,
818 host_loader,
819 host_domain,
820 &st,
821 InstanceKlass::cast(host_klass),
822 cp_patches,
823 CHECK_NULL);
824 if (anonk == NULL) {
825 return NULL;
826 }
827
828 return InstanceKlass::cast(anonk);
829 }
830
831 UNSAFE_ENTRY(jclass, Unsafe_DefineAnonymousClass0(JNIEnv *env, jobject unsafe, jclass host_class, jbyteArray data, jobjectArray cp_patches_jh)) {
832 ResourceMark rm(THREAD);
833
834 jobject res_jh = NULL;
835 u1* temp_alloc = NULL;
836
837 InstanceKlass* anon_klass = Unsafe_DefineAnonymousClass_impl(env, host_class, data, cp_patches_jh, &temp_alloc, THREAD);
838 if (anon_klass != NULL) {
839 res_jh = JNIHandles::make_local(env, anon_klass->java_mirror());
840 }
841
842 // try/finally clause:
843 if (temp_alloc != NULL) {
844 FREE_C_HEAP_ARRAY(u1, temp_alloc);
845 }
846
847 // The anonymous class loader data has been artificially been kept alive to
848 // this point. The mirror and any instances of this class have to keep
849 // it alive afterwards.
850 if (anon_klass != NULL) {
851 anon_klass->class_loader_data()->dec_keep_alive();
852 }
853
854 // let caller initialize it as needed...
855
856 return (jclass) res_jh;
857 } UNSAFE_END
858
859
860
861 UNSAFE_ENTRY(void, Unsafe_ThrowException(JNIEnv *env, jobject unsafe, jthrowable thr)) {
862 ThreadToNativeFromVM ttnfv(thread);
863 env->Throw(thr);
864 } UNSAFE_END
865
866 // JSR166 ------------------------------------------------------------------
867
868 UNSAFE_ENTRY(jobject, Unsafe_CompareAndExchangeReference(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jobject e_h, jobject x_h)) {
869 oop x = JNIHandles::resolve(x_h);
870 oop e = JNIHandles::resolve(e_h);
871 oop p = JNIHandles::resolve(obj);
872 assert_field_offset_sane(p, offset);
873 oop res = HeapAccess<ON_UNKNOWN_OOP_REF>::oop_atomic_cmpxchg_at(x, p, (ptrdiff_t)offset, e);
874 return JNIHandles::make_local(env, res);
875 } UNSAFE_END
876
877 UNSAFE_ENTRY(jint, Unsafe_CompareAndExchangeInt(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jint e, jint x)) {
878 oop p = JNIHandles::resolve(obj);
879 if (p == NULL) {
880 volatile jint* addr = (volatile jint*)index_oop_from_field_offset_long(p, offset);
881 return RawAccess<>::atomic_cmpxchg(x, addr, e);
882 } else {
883 assert_field_offset_sane(p, offset);
884 return HeapAccess<>::atomic_cmpxchg_at(x, p, (ptrdiff_t)offset, e);
885 }
886 } UNSAFE_END
887
888 UNSAFE_ENTRY(jlong, Unsafe_CompareAndExchangeLong(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jlong e, jlong x)) {
889 oop p = JNIHandles::resolve(obj);
890 if (p == NULL) {
891 volatile jlong* addr = (volatile jlong*)index_oop_from_field_offset_long(p, offset);
892 return RawAccess<>::atomic_cmpxchg(x, addr, e);
893 } else {
894 assert_field_offset_sane(p, offset);
895 return HeapAccess<>::atomic_cmpxchg_at(x, p, (ptrdiff_t)offset, e);
896 }
897 } UNSAFE_END
898
899 UNSAFE_ENTRY(jboolean, Unsafe_CompareAndSetReference(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jobject e_h, jobject x_h)) {
900 oop x = JNIHandles::resolve(x_h);
901 oop e = JNIHandles::resolve(e_h);
902 oop p = JNIHandles::resolve(obj);
903 assert_field_offset_sane(p, offset);
904 oop ret = HeapAccess<ON_UNKNOWN_OOP_REF>::oop_atomic_cmpxchg_at(x, p, (ptrdiff_t)offset, e);
905 return oopDesc::equals(ret, e);
906 } UNSAFE_END
907
908 UNSAFE_ENTRY(jboolean, Unsafe_CompareAndSetInt(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jint e, jint x)) {
909 oop p = JNIHandles::resolve(obj);
910 if (p == NULL) {
911 volatile jint* addr = (volatile jint*)index_oop_from_field_offset_long(p, offset);
912 return RawAccess<>::atomic_cmpxchg(x, addr, e) == e;
913 } else {
914 assert_field_offset_sane(p, offset);
915 return HeapAccess<>::atomic_cmpxchg_at(x, p, (ptrdiff_t)offset, e) == e;
916 }
917 } UNSAFE_END
918
919 UNSAFE_ENTRY(jboolean, Unsafe_CompareAndSetLong(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jlong e, jlong x)) {
920 oop p = JNIHandles::resolve(obj);
921 if (p == NULL) {
922 volatile jlong* addr = (volatile jlong*)index_oop_from_field_offset_long(p, offset);
923 return RawAccess<>::atomic_cmpxchg(x, addr, e) == e;
924 } else {
925 assert_field_offset_sane(p, offset);
926 return HeapAccess<>::atomic_cmpxchg_at(x, p, (ptrdiff_t)offset, e) == e;
927 }
928 } UNSAFE_END
929
930 static void post_thread_park_event(EventThreadPark* event, const oop obj, jlong timeout_nanos, jlong until_epoch_millis) {
931 assert(event != NULL, "invariant");
932 assert(event->should_commit(), "invariant");
933 event->set_parkedClass((obj != NULL) ? obj->klass() : NULL);
934 event->set_timeout(timeout_nanos);
935 event->set_until(until_epoch_millis);
936 event->set_address((obj != NULL) ? (u8)cast_from_oop<uintptr_t>(obj) : 0);
937 event->commit();
938 }
939
940 UNSAFE_ENTRY(void, Unsafe_Park(JNIEnv *env, jobject unsafe, jboolean isAbsolute, jlong time)) {
941 HOTSPOT_THREAD_PARK_BEGIN((uintptr_t) thread->parker(), (int) isAbsolute, time);
942 EventThreadPark event;
943
944 JavaThreadParkedState jtps(thread, time != 0);
945 thread->parker()->park(isAbsolute != 0, time);
946 if (event.should_commit()) {
947 const oop obj = thread->current_park_blocker();
948 if (time == 0) {
949 post_thread_park_event(&event, obj, min_jlong, min_jlong);
950 } else {
951 if (isAbsolute != 0) {
952 post_thread_park_event(&event, obj, min_jlong, time);
953 } else {
954 post_thread_park_event(&event, obj, time, min_jlong);
955 }
956 }
957 }
958 HOTSPOT_THREAD_PARK_END((uintptr_t) thread->parker());
959 } UNSAFE_END
960
961 UNSAFE_ENTRY(void, Unsafe_Unpark(JNIEnv *env, jobject unsafe, jobject jthread)) {
962 Parker* p = NULL;
963
964 if (jthread != NULL) {
965 ThreadsListHandle tlh;
966 JavaThread* thr = NULL;
967 oop java_thread = NULL;
968 (void) tlh.cv_internal_thread_to_JavaThread(jthread, &thr, &java_thread);
969 if (java_thread != NULL) {
970 // This is a valid oop.
971 jlong lp = java_lang_Thread::park_event(java_thread);
972 if (lp != 0) {
973 // This cast is OK even though the jlong might have been read
974 // non-atomically on 32bit systems, since there, one word will
975 // always be zero anyway and the value set is always the same
976 p = (Parker*)addr_from_java(lp);
977 } else {
978 // Not cached in the java.lang.Thread oop yet (could be an
979 // older version of library).
980 if (thr != NULL) {
981 // The JavaThread is alive.
982 p = thr->parker();
983 if (p != NULL) {
984 // Cache the Parker in the java.lang.Thread oop for next time.
985 java_lang_Thread::set_park_event(java_thread, addr_to_java(p));
986 }
987 }
988 }
989 }
990 } // ThreadsListHandle is destroyed here.
991
992 if (p != NULL) {
993 HOTSPOT_THREAD_UNPARK((uintptr_t) p);
994 p->unpark();
995 }
996 } UNSAFE_END
997
998 UNSAFE_ENTRY(jint, Unsafe_GetLoadAverage0(JNIEnv *env, jobject unsafe, jdoubleArray loadavg, jint nelem)) {
999 const int max_nelem = 3;
1000 double la[max_nelem];
1001 jint ret;
1002
1003 typeArrayOop a = typeArrayOop(JNIHandles::resolve_non_null(loadavg));
1004 assert(a->is_typeArray(), "must be type array");
1005
1006 ret = os::loadavg(la, nelem);
1007 if (ret == -1) {
1008 return -1;
1009 }
1010
1011 // if successful, ret is the number of samples actually retrieved.
1012 assert(ret >= 0 && ret <= max_nelem, "Unexpected loadavg return value");
1013 switch(ret) {
1014 case 3: a->double_at_put(2, (jdouble)la[2]); // fall through
1015 case 2: a->double_at_put(1, (jdouble)la[1]); // fall through
1016 case 1: a->double_at_put(0, (jdouble)la[0]); break;
1017 }
1018
1019 return ret;
1020 } UNSAFE_END
1021
1022
1023 /// JVM_RegisterUnsafeMethods
1024
1025 #define ADR "J"
1026
1027 #define LANG "Ljava/lang/"
1028
1029 #define OBJ LANG "Object;"
1030 #define CLS LANG "Class;"
1031 #define FLD LANG "reflect/Field;"
1032 #define THR LANG "Throwable;"
1033
1034 #define DC_Args LANG "String;[BII" LANG "ClassLoader;" "Ljava/security/ProtectionDomain;"
1035 #define DAC_Args CLS "[B[" OBJ
1036
1037 #define CC (char*) /*cast a literal from (const char*)*/
1038 #define FN_PTR(f) CAST_FROM_FN_PTR(void*, &f)
1039
1040 #define DECLARE_GETPUTOOP(Type, Desc) \
1041 {CC "get" #Type, CC "(" OBJ "J)" #Desc, FN_PTR(Unsafe_Get##Type)}, \
1042 {CC "put" #Type, CC "(" OBJ "J" #Desc ")V", FN_PTR(Unsafe_Put##Type)}, \
1043 {CC "get" #Type "Volatile", CC "(" OBJ "J)" #Desc, FN_PTR(Unsafe_Get##Type##Volatile)}, \
1044 {CC "put" #Type "Volatile", CC "(" OBJ "J" #Desc ")V", FN_PTR(Unsafe_Put##Type##Volatile)}
1045
1046
1047 static JNINativeMethod jdk_internal_misc_Unsafe_methods[] = {
1048 {CC "getReference", CC "(" OBJ "J)" OBJ "", FN_PTR(Unsafe_GetReference)},
1049 {CC "putReference", CC "(" OBJ "J" OBJ ")V", FN_PTR(Unsafe_PutReference)},
1050 {CC "getReferenceVolatile", CC "(" OBJ "J)" OBJ, FN_PTR(Unsafe_GetReferenceVolatile)},
1051 {CC "putReferenceVolatile", CC "(" OBJ "J" OBJ ")V", FN_PTR(Unsafe_PutReferenceVolatile)},
1052
1053 {CC "getUncompressedObject", CC "(" ADR ")" OBJ, FN_PTR(Unsafe_GetUncompressedObject)},
1054
1055 DECLARE_GETPUTOOP(Boolean, Z),
1056 DECLARE_GETPUTOOP(Byte, B),
1057 DECLARE_GETPUTOOP(Short, S),
1058 DECLARE_GETPUTOOP(Char, C),
1059 DECLARE_GETPUTOOP(Int, I),
1060 DECLARE_GETPUTOOP(Long, J),
1061 DECLARE_GETPUTOOP(Float, F),
1062 DECLARE_GETPUTOOP(Double, D),
1063
1064 {CC "allocateMemory0", CC "(J)" ADR, FN_PTR(Unsafe_AllocateMemory0)},
1065 {CC "reallocateMemory0", CC "(" ADR "J)" ADR, FN_PTR(Unsafe_ReallocateMemory0)},
1066 {CC "freeMemory0", CC "(" ADR ")V", FN_PTR(Unsafe_FreeMemory0)},
1067
1068 {CC "objectFieldOffset0", CC "(" FLD ")J", FN_PTR(Unsafe_ObjectFieldOffset0)},
1069 {CC "objectFieldOffset1", CC "(" CLS LANG "String;)J", FN_PTR(Unsafe_ObjectFieldOffset1)},
1070 {CC "staticFieldOffset0", CC "(" FLD ")J", FN_PTR(Unsafe_StaticFieldOffset0)},
1071 {CC "staticFieldBase0", CC "(" FLD ")" OBJ, FN_PTR(Unsafe_StaticFieldBase0)},
1072 {CC "ensureClassInitialized0", CC "(" CLS ")V", FN_PTR(Unsafe_EnsureClassInitialized0)},
1073 {CC "arrayBaseOffset0", CC "(" CLS ")I", FN_PTR(Unsafe_ArrayBaseOffset0)},
1074 {CC "arrayIndexScale0", CC "(" CLS ")I", FN_PTR(Unsafe_ArrayIndexScale0)},
1075 {CC "addressSize0", CC "()I", FN_PTR(Unsafe_AddressSize0)},
1076 {CC "pageSize", CC "()I", FN_PTR(Unsafe_PageSize)},
1077
1078 {CC "defineClass0", CC "(" DC_Args ")" CLS, FN_PTR(Unsafe_DefineClass0)},
1079 {CC "allocateInstance", CC "(" CLS ")" OBJ, FN_PTR(Unsafe_AllocateInstance)},
1080 {CC "throwException", CC "(" THR ")V", FN_PTR(Unsafe_ThrowException)},
1081 {CC "compareAndSetReference",CC "(" OBJ "J" OBJ "" OBJ ")Z", FN_PTR(Unsafe_CompareAndSetReference)},
1082 {CC "compareAndSetInt", CC "(" OBJ "J""I""I"")Z", FN_PTR(Unsafe_CompareAndSetInt)},
1083 {CC "compareAndSetLong", CC "(" OBJ "J""J""J"")Z", FN_PTR(Unsafe_CompareAndSetLong)},
1084 {CC "compareAndExchangeReference", CC "(" OBJ "J" OBJ "" OBJ ")" OBJ, FN_PTR(Unsafe_CompareAndExchangeReference)},
1085 {CC "compareAndExchangeInt", CC "(" OBJ "J""I""I"")I", FN_PTR(Unsafe_CompareAndExchangeInt)},
1086 {CC "compareAndExchangeLong", CC "(" OBJ "J""J""J"")J", FN_PTR(Unsafe_CompareAndExchangeLong)},
1087
1088 {CC "park", CC "(ZJ)V", FN_PTR(Unsafe_Park)},
1089 {CC "unpark", CC "(" OBJ ")V", FN_PTR(Unsafe_Unpark)},
1090
1091 {CC "getLoadAverage0", CC "([DI)I", FN_PTR(Unsafe_GetLoadAverage0)},
1092
1093 {CC "copyMemory0", CC "(" OBJ "J" OBJ "JJ)V", FN_PTR(Unsafe_CopyMemory0)},
1094 {CC "copySwapMemory0", CC "(" OBJ "J" OBJ "JJJ)V", FN_PTR(Unsafe_CopySwapMemory0)},
1095 {CC "setMemory0", CC "(" OBJ "JJB)V", FN_PTR(Unsafe_SetMemory0)},
1096
1097 {CC "defineAnonymousClass0", CC "(" DAC_Args ")" CLS, FN_PTR(Unsafe_DefineAnonymousClass0)},
1098
1099 {CC "shouldBeInitialized0", CC "(" CLS ")Z", FN_PTR(Unsafe_ShouldBeInitialized0)},
1100
1101 {CC "loadFence", CC "()V", FN_PTR(Unsafe_LoadFence)},
1102 {CC "storeFence", CC "()V", FN_PTR(Unsafe_StoreFence)},
1103 {CC "fullFence", CC "()V", FN_PTR(Unsafe_FullFence)},
1104
1105 {CC "isBigEndian0", CC "()Z", FN_PTR(Unsafe_isBigEndian0)},
1106 {CC "unalignedAccess0", CC "()Z", FN_PTR(Unsafe_unalignedAccess0)}
1107 };
1108
1109 #undef CC
1110 #undef FN_PTR
1111
1112 #undef ADR
1113 #undef LANG
1114 #undef OBJ
1115 #undef CLS
1116 #undef FLD
1117 #undef THR
1118 #undef DC_Args
1119 #undef DAC_Args
1120
1121 #undef DECLARE_GETPUTOOP
1122
1123
1124 // This function is exported, used by NativeLookup.
1125 // The Unsafe_xxx functions above are called only from the interpreter.
1126 // The optimizer looks at names and signatures to recognize
1127 // individual functions.
1128
1129 JVM_ENTRY(void, JVM_RegisterJDKInternalMiscUnsafeMethods(JNIEnv *env, jclass unsafeclass)) {
1130 ThreadToNativeFromVM ttnfv(thread);
1131
1132 int ok = env->RegisterNatives(unsafeclass, jdk_internal_misc_Unsafe_methods, sizeof(jdk_internal_misc_Unsafe_methods)/sizeof(JNINativeMethod));
1133 guarantee(ok == 0, "register jdk.internal.misc.Unsafe natives");
1134 } JVM_END