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/classFileStream.hpp"
27 #include "classfile/vmSymbols.hpp"
28 #include "memory/allocation.inline.hpp"
29 #include "memory/resourceArea.hpp"
30 #include "oops/objArrayOop.inline.hpp"
31 #include "oops/oop.inline.hpp"
32 #include "prims/jni.h"
33 #include "prims/jvm.h"
34 #include "prims/unsafe.hpp"
35 #include "runtime/atomic.inline.hpp"
36 #include "runtime/globals.hpp"
37 #include "runtime/interfaceSupport.hpp"
38 #include "runtime/orderAccess.inline.hpp"
39 #include "runtime/reflection.hpp"
40 #include "runtime/vm_version.hpp"
41 #include "services/threadService.hpp"
42 #include "trace/tracing.hpp"
43 #include "utilities/copy.hpp"
44 #include "utilities/dtrace.hpp"
45 #include "utilities/macros.hpp"
46 #if INCLUDE_ALL_GCS
47 #include "gc/g1/g1SATBCardTableModRefBS.hpp"
48 #endif // INCLUDE_ALL_GCS
49
50 /**
51 * Implementation of the jdk.internal.misc.Unsafe class
52 */
53
54
55 #define MAX_OBJECT_SIZE \
56 ( arrayOopDesc::header_size(T_DOUBLE) * HeapWordSize \
57 + ((julong)max_jint * sizeof(double)) )
58
59
60 #define UNSAFE_ENTRY(result_type, header) \
61 JVM_ENTRY(static result_type, header)
62
63 #define UNSAFE_LEAF(result_type, header) \
64 JVM_LEAF(static result_type, header)
65
66 #define UNSAFE_END JVM_END
67
68
69 static inline void* addr_from_java(jlong addr) {
70 // This assert fails in a variety of ways on 32-bit systems.
71 // It is impossible to predict whether native code that converts
72 // pointers to longs will sign-extend or zero-extend the addresses.
73 //assert(addr == (uintptr_t)addr, "must not be odd high bits");
74 return (void*)(uintptr_t)addr;
75 }
76
77 static inline jlong addr_to_java(void* p) {
78 assert(p == (void*)(uintptr_t)p, "must not be odd high bits");
79 return (uintptr_t)p;
80 }
81
82
83 // Note: The VM's obj_field and related accessors use byte-scaled
84 // ("unscaled") offsets, just as the unsafe methods do.
85
86 // However, the method Unsafe.fieldOffset explicitly declines to
87 // guarantee this. The field offset values manipulated by the Java user
88 // through the Unsafe API are opaque cookies that just happen to be byte
89 // offsets. We represent this state of affairs by passing the cookies
90 // through conversion functions when going between the VM and the Unsafe API.
91 // The conversion functions just happen to be no-ops at present.
92
93 static inline jlong field_offset_to_byte_offset(jlong field_offset) {
94 return field_offset;
95 }
96
97 static inline jlong field_offset_from_byte_offset(jlong byte_offset) {
98 return byte_offset;
99 }
100
101 static inline void* index_oop_from_field_offset_long(oop p, jlong field_offset) {
102 jlong byte_offset = field_offset_to_byte_offset(field_offset);
103
104 #ifdef ASSERT
105 if (p != NULL) {
106 assert(byte_offset >= 0 && byte_offset <= (jlong)MAX_OBJECT_SIZE, "sane offset");
107 if (byte_offset == (jint)byte_offset) {
108 void* ptr_plus_disp = (address)p + byte_offset;
109 assert((void*)p->obj_field_addr<oop>((jint)byte_offset) == ptr_plus_disp,
110 "raw [ptr+disp] must be consistent with oop::field_base");
111 }
112 jlong p_size = HeapWordSize * (jlong)(p->size());
113 assert(byte_offset < p_size, "Unsafe access: offset " INT64_FORMAT " > object's size " INT64_FORMAT, byte_offset, p_size);
114 }
115 #endif
116
117 if (sizeof(char*) == sizeof(jint)) { // (this constant folds!)
118 return (address)p + (jint) byte_offset;
119 } else {
120 return (address)p + byte_offset;
121 }
122 }
123
124 // Externally callable versions:
125 // (Use these in compiler intrinsics which emulate unsafe primitives.)
126 jlong Unsafe_field_offset_to_byte_offset(jlong field_offset) {
127 return field_offset;
128 }
129 jlong Unsafe_field_offset_from_byte_offset(jlong byte_offset) {
130 return byte_offset;
131 }
132
133
134 ///// Data read/writes on the Java heap and in native (off-heap) memory
135
136 /**
137 * Helper class for accessing memory.
138 *
139 * Normalizes values and wraps accesses in
140 * JavaThread::doing_unsafe_access() if needed.
141 */
142 class MemoryAccess : StackObj {
143 JavaThread* _thread;
144 jobject _obj;
145 jlong _offset;
146
147 // Resolves and returns the address of the memory access
148 void* addr() {
149 return index_oop_from_field_offset_long(JNIHandles::resolve(_obj), _offset);
150 }
151
152 template <typename T>
153 T normalize(T x) {
154 return x;
155 }
156
157 jboolean normalize(jboolean x) {
158 return x & 1;
159 }
160
161 /**
162 * Helper class to wrap memory accesses in JavaThread::doing_unsafe_access()
163 */
164 class GuardUnsafeAccess {
165 JavaThread* _thread;
166 bool _active;
167
168 public:
169 GuardUnsafeAccess(JavaThread* thread, jobject _obj) : _thread(thread) {
170 if (JNIHandles::resolve(_obj) == NULL) {
171 // native/off-heap access which may raise SIGBUS if accessing
172 // memory mapped file data in a region of the file which has
173 // been truncated and is now invalid
174 _thread->set_doing_unsafe_access(true);
175 _active = true;
176 } else {
177 _active = false;
178 }
179 }
180
181 ~GuardUnsafeAccess() {
182 if (_active) {
183 _thread->set_doing_unsafe_access(false);
184 }
185 }
186 };
187
188 public:
189 MemoryAccess(JavaThread* thread, jobject obj, jlong offset)
190 : _thread(thread), _obj(obj), _offset(offset) {
191 }
192
193 template <typename T>
194 T get() {
195 GuardUnsafeAccess guard(_thread, _obj);
196
197 T* p = (T*)addr();
198
199 T x = *p;
200
201 return x;
202 }
203
204 template <typename T>
205 void put(T x) {
206 GuardUnsafeAccess guard(_thread, _obj);
207
208 T* p = (T*)addr();
209
210 *p = normalize(x);
211 }
212
213
214 template <typename T>
215 T get_volatile() {
216 GuardUnsafeAccess guard(_thread, _obj);
217
218 T* p = (T*)addr();
219
220 if (support_IRIW_for_not_multiple_copy_atomic_cpu) {
221 OrderAccess::fence();
222 }
223
224 T x = OrderAccess::load_acquire((volatile T*)p);
225
226 return x;
227 }
228
229 template <typename T>
230 void put_volatile(T x) {
231 GuardUnsafeAccess guard(_thread, _obj);
232
233 T* p = (T*)addr();
234
235 OrderAccess::release_store_fence((volatile T*)p, normalize(x));
236 }
237
238
239 #ifndef SUPPORTS_NATIVE_CX8
240 jlong get_jlong_locked() {
241 GuardUnsafeAccess guard(_thread, _obj);
242
243 MutexLockerEx mu(UnsafeJlong_lock, Mutex::_no_safepoint_check_flag);
244
245 jlong* p = (jlong*)addr();
246
247 jlong x = Atomic::load(p);
248
249 return x;
250 }
251
252 void put_jlong_locked(jlong x) {
253 GuardUnsafeAccess guard(_thread, _obj);
254
255 MutexLockerEx mu(UnsafeJlong_lock, Mutex::_no_safepoint_check_flag);
256
257 jlong* p = (jlong*)addr();
258
259 Atomic::store(normalize(x), p);
260 }
261 #endif
262 };
263
264 // Get/PutObject must be special-cased, since it works with handles.
265
266 // These functions allow a null base pointer with an arbitrary address.
267 // But if the base pointer is non-null, the offset should make some sense.
268 // That is, it should be in the range [0, MAX_OBJECT_SIZE].
269 UNSAFE_ENTRY(jobject, Unsafe_GetObject(JNIEnv *env, jobject unsafe, jobject obj, jlong offset)) {
270 oop p = JNIHandles::resolve(obj);
271 oop v;
272
273 if (UseCompressedOops) {
274 narrowOop n = *(narrowOop*)index_oop_from_field_offset_long(p, offset);
275 v = oopDesc::decode_heap_oop(n);
276 } else {
277 v = *(oop*)index_oop_from_field_offset_long(p, offset);
278 }
279
280 jobject ret = JNIHandles::make_local(env, v);
281
282 #if INCLUDE_ALL_GCS
283 // We could be accessing the referent field in a reference
284 // object. If G1 is enabled then we need to register non-null
285 // referent with the SATB barrier.
286 if (UseG1GC) {
287 bool needs_barrier = false;
288
289 if (ret != NULL) {
290 if (offset == java_lang_ref_Reference::referent_offset && obj != NULL) {
291 oop o = JNIHandles::resolve(obj);
292 Klass* k = o->klass();
293 if (InstanceKlass::cast(k)->reference_type() != REF_NONE) {
294 assert(InstanceKlass::cast(k)->is_subclass_of(SystemDictionary::Reference_klass()), "sanity");
295 needs_barrier = true;
296 }
297 }
298 }
299
300 if (needs_barrier) {
301 oop referent = JNIHandles::resolve(ret);
302 G1SATBCardTableModRefBS::enqueue(referent);
303 }
304 }
305 #endif // INCLUDE_ALL_GCS
306
307 return ret;
308 } UNSAFE_END
309
310 UNSAFE_ENTRY(void, Unsafe_PutObject(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jobject x_h)) {
311 oop x = JNIHandles::resolve(x_h);
312 oop p = JNIHandles::resolve(obj);
313
314 if (UseCompressedOops) {
315 oop_store((narrowOop*)index_oop_from_field_offset_long(p, offset), x);
316 } else {
317 oop_store((oop*)index_oop_from_field_offset_long(p, offset), x);
318 }
319 } UNSAFE_END
320
321 UNSAFE_ENTRY(jobject, Unsafe_GetObjectVolatile(JNIEnv *env, jobject unsafe, jobject obj, jlong offset)) {
322 oop p = JNIHandles::resolve(obj);
323 void* addr = index_oop_from_field_offset_long(p, offset);
324
325 volatile oop v;
326
327 if (UseCompressedOops) {
328 volatile narrowOop n = *(volatile narrowOop*) addr;
329 (void)const_cast<oop&>(v = oopDesc::decode_heap_oop(n));
330 } else {
331 (void)const_cast<oop&>(v = *(volatile oop*) addr);
332 }
333
334 OrderAccess::acquire();
335 return JNIHandles::make_local(env, v);
336 } UNSAFE_END
337
338 UNSAFE_ENTRY(void, Unsafe_PutObjectVolatile(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jobject x_h)) {
339 oop x = JNIHandles::resolve(x_h);
340 oop p = JNIHandles::resolve(obj);
341 void* addr = index_oop_from_field_offset_long(p, offset);
342 OrderAccess::release();
343
344 if (UseCompressedOops) {
345 oop_store((narrowOop*)addr, x);
346 } else {
347 oop_store((oop*)addr, x);
348 }
349
350 OrderAccess::fence();
351 } UNSAFE_END
352
353 UNSAFE_ENTRY(jobject, Unsafe_GetUncompressedObject(JNIEnv *env, jobject unsafe, jlong addr)) {
354 oop v = *(oop*) (address) addr;
355
356 return JNIHandles::make_local(env, v);
357 } UNSAFE_END
358
359 #ifndef SUPPORTS_NATIVE_CX8
360
361 // VM_Version::supports_cx8() is a surrogate for 'supports atomic long memory ops'.
362 //
363 // On platforms which do not support atomic compare-and-swap of jlong (8 byte)
364 // values we have to use a lock-based scheme to enforce atomicity. This has to be
365 // applied to all Unsafe operations that set the value of a jlong field. Even so
366 // the compareAndSwapLong operation will not be atomic with respect to direct stores
367 // to the field from Java code. It is important therefore that any Java code that
368 // utilizes these Unsafe jlong operations does not perform direct stores. To permit
369 // direct loads of the field from Java code we must also use Atomic::store within the
370 // locked regions. And for good measure, in case there are direct stores, we also
371 // employ Atomic::load within those regions. Note that the field in question must be
372 // volatile and so must have atomic load/store accesses applied at the Java level.
373 //
374 // The locking scheme could utilize a range of strategies for controlling the locking
375 // granularity: from a lock per-field through to a single global lock. The latter is
376 // the simplest and is used for the current implementation. Note that the Java object
377 // that contains the field, can not, in general, be used for locking. To do so can lead
378 // to deadlocks as we may introduce locking into what appears to the Java code to be a
379 // lock-free path.
380 //
381 // As all the locked-regions are very short and themselves non-blocking we can treat
382 // them as leaf routines and elide safepoint checks (ie we don't perform any thread
383 // state transitions even when blocking for the lock). Note that if we do choose to
384 // add safepoint checks and thread state transitions, we must ensure that we calculate
385 // the address of the field _after_ we have acquired the lock, else the object may have
386 // been moved by the GC
387
388 UNSAFE_ENTRY(jlong, Unsafe_GetLongVolatile(JNIEnv *env, jobject unsafe, jobject obj, jlong offset)) {
389 if (VM_Version::supports_cx8()) {
390 return MemoryAccess(thread, obj, offset).get_volatile<jlong>();
391 } else {
392 return MemoryAccess(thread, obj, offset).get_jlong_locked();
393 }
394 } UNSAFE_END
395
396 UNSAFE_ENTRY(void, Unsafe_PutLongVolatile(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jlong x)) {
397 if (VM_Version::supports_cx8()) {
398 MemoryAccess(thread, obj, offset).put_volatile<jlong>(x);
399 } else {
400 MemoryAccess(thread, obj, offset).put_jlong_locked(x);
401 }
402 } UNSAFE_END
403
404 #endif // not SUPPORTS_NATIVE_CX8
405
406 UNSAFE_LEAF(jboolean, Unsafe_isBigEndian0(JNIEnv *env, jobject unsafe)) {
407 #ifdef VM_LITTLE_ENDIAN
408 return false;
409 #else
410 return true;
411 #endif
412 } UNSAFE_END
413
414 UNSAFE_LEAF(jint, Unsafe_unalignedAccess0(JNIEnv *env, jobject unsafe)) {
415 return UseUnalignedAccesses;
416 } UNSAFE_END
417
418 #define DEFINE_GETSETOOP(java_type, Type) \
419 \
420 UNSAFE_ENTRY(java_type, Unsafe_Get##Type(JNIEnv *env, jobject unsafe, jobject obj, jlong offset)) { \
421 return MemoryAccess(thread, obj, offset).get<java_type>(); \
422 } UNSAFE_END \
423 \
424 UNSAFE_ENTRY(void, Unsafe_Put##Type(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, java_type x)) { \
425 MemoryAccess(thread, obj, offset).put<java_type>(x); \
426 } UNSAFE_END \
427 \
428 // END DEFINE_GETSETOOP.
429
430 DEFINE_GETSETOOP(jboolean, Boolean)
431 DEFINE_GETSETOOP(jbyte, Byte)
432 DEFINE_GETSETOOP(jshort, Short);
433 DEFINE_GETSETOOP(jchar, Char);
434 DEFINE_GETSETOOP(jint, Int);
435 DEFINE_GETSETOOP(jlong, Long);
436 DEFINE_GETSETOOP(jfloat, Float);
437 DEFINE_GETSETOOP(jdouble, Double);
438
439 #undef DEFINE_GETSETOOP
440
441 #define DEFINE_GETSETOOP_VOLATILE(java_type, Type) \
442 \
443 UNSAFE_ENTRY(java_type, Unsafe_Get##Type##Volatile(JNIEnv *env, jobject unsafe, jobject obj, jlong offset)) { \
444 return MemoryAccess(thread, obj, offset).get_volatile<java_type>(); \
445 } UNSAFE_END \
446 \
447 UNSAFE_ENTRY(void, Unsafe_Put##Type##Volatile(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, java_type x)) { \
448 MemoryAccess(thread, obj, offset).put_volatile<java_type>(x); \
449 } UNSAFE_END \
450 \
451 // END DEFINE_GETSETOOP_VOLATILE.
452
453 DEFINE_GETSETOOP_VOLATILE(jboolean, Boolean)
454 DEFINE_GETSETOOP_VOLATILE(jbyte, Byte)
455 DEFINE_GETSETOOP_VOLATILE(jshort, Short);
456 DEFINE_GETSETOOP_VOLATILE(jchar, Char);
457 DEFINE_GETSETOOP_VOLATILE(jint, Int);
458 DEFINE_GETSETOOP_VOLATILE(jfloat, Float);
459 DEFINE_GETSETOOP_VOLATILE(jdouble, Double);
460
461 #ifdef SUPPORTS_NATIVE_CX8
462 DEFINE_GETSETOOP_VOLATILE(jlong, Long);
463 #endif
464
465 #undef DEFINE_GETSETOOP_VOLATILE
466
467 UNSAFE_LEAF(void, Unsafe_LoadFence(JNIEnv *env, jobject unsafe)) {
468 OrderAccess::acquire();
469 } UNSAFE_END
470
471 UNSAFE_LEAF(void, Unsafe_StoreFence(JNIEnv *env, jobject unsafe)) {
472 OrderAccess::release();
473 } UNSAFE_END
474
475 UNSAFE_LEAF(void, Unsafe_FullFence(JNIEnv *env, jobject unsafe)) {
476 OrderAccess::fence();
477 } UNSAFE_END
478
479 ////// Allocation requests
480
481 UNSAFE_ENTRY(jobject, Unsafe_AllocateInstance(JNIEnv *env, jobject unsafe, jclass cls)) {
482 ThreadToNativeFromVM ttnfv(thread);
483 return env->AllocObject(cls);
484 } UNSAFE_END
485
486 UNSAFE_ENTRY(jlong, Unsafe_AllocateMemory0(JNIEnv *env, jobject unsafe, jlong size)) {
487 size_t sz = (size_t)size;
488
489 sz = round_to(sz, HeapWordSize);
490 void* x = os::malloc(sz, mtInternal);
491
492 return addr_to_java(x);
493 } UNSAFE_END
494
495 UNSAFE_ENTRY(jlong, Unsafe_ReallocateMemory0(JNIEnv *env, jobject unsafe, jlong addr, jlong size)) {
496 void* p = addr_from_java(addr);
497 size_t sz = (size_t)size;
498 sz = round_to(sz, HeapWordSize);
499
500 void* x = os::realloc(p, sz, mtInternal);
501
502 return addr_to_java(x);
503 } UNSAFE_END
504
505 UNSAFE_ENTRY(void, Unsafe_FreeMemory0(JNIEnv *env, jobject unsafe, jlong addr)) {
506 void* p = addr_from_java(addr);
507
508 os::free(p);
509 } UNSAFE_END
510
511 UNSAFE_ENTRY(void, Unsafe_SetMemory0(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jlong size, jbyte value)) {
512 size_t sz = (size_t)size;
513
514 oop base = JNIHandles::resolve(obj);
515 void* p = index_oop_from_field_offset_long(base, offset);
516
517 Copy::fill_to_memory_atomic(p, sz, value);
518 } UNSAFE_END
519
520 UNSAFE_ENTRY(void, Unsafe_CopyMemory0(JNIEnv *env, jobject unsafe, jobject srcObj, jlong srcOffset, jobject dstObj, jlong dstOffset, jlong size)) {
521 size_t sz = (size_t)size;
522
523 oop srcp = JNIHandles::resolve(srcObj);
524 oop dstp = JNIHandles::resolve(dstObj);
525
526 void* src = index_oop_from_field_offset_long(srcp, srcOffset);
527 void* dst = index_oop_from_field_offset_long(dstp, dstOffset);
528
529 Copy::conjoint_memory_atomic(src, dst, sz);
530 } UNSAFE_END
531
532 // This function is a leaf since if the source and destination are both in native memory
533 // the copy may potentially be very large, and we don't want to disable GC if we can avoid it.
534 // If either source or destination (or both) are on the heap, the function will enter VM using
535 // JVM_ENTRY_FROM_LEAF
536 UNSAFE_LEAF(void, Unsafe_CopySwapMemory0(JNIEnv *env, jobject unsafe, jobject srcObj, jlong srcOffset, jobject dstObj, jlong dstOffset, jlong size, jlong elemSize)) {
537 size_t sz = (size_t)size;
538 size_t esz = (size_t)elemSize;
539
540 if (srcObj == NULL && dstObj == NULL) {
541 // Both src & dst are in native memory
542 address src = (address)srcOffset;
543 address dst = (address)dstOffset;
544
545 Copy::conjoint_swap(src, dst, sz, esz);
546 } else {
547 // At least one of src/dst are on heap, transition to VM to access raw pointers
548
549 JVM_ENTRY_FROM_LEAF(env, void, Unsafe_CopySwapMemory0) {
550 oop srcp = JNIHandles::resolve(srcObj);
551 oop dstp = JNIHandles::resolve(dstObj);
552
553 address src = (address)index_oop_from_field_offset_long(srcp, srcOffset);
554 address dst = (address)index_oop_from_field_offset_long(dstp, dstOffset);
555
556 Copy::conjoint_swap(src, dst, sz, esz);
557 } JVM_END
558 }
559 } UNSAFE_END
560
561 ////// Random queries
562
563 UNSAFE_LEAF(jint, Unsafe_AddressSize0(JNIEnv *env, jobject unsafe)) {
564 return sizeof(void*);
565 } UNSAFE_END
566
567 UNSAFE_LEAF(jint, Unsafe_PageSize()) {
568 return os::vm_page_size();
569 } UNSAFE_END
570
571 static jint find_field_offset(jobject field, int must_be_static, TRAPS) {
572 assert(field != NULL, "field must not be NULL");
573
574 oop reflected = JNIHandles::resolve_non_null(field);
575 oop mirror = java_lang_reflect_Field::clazz(reflected);
576 Klass* k = java_lang_Class::as_Klass(mirror);
577 int slot = java_lang_reflect_Field::slot(reflected);
578 int modifiers = java_lang_reflect_Field::modifiers(reflected);
579
580 if (must_be_static >= 0) {
581 int really_is_static = ((modifiers & JVM_ACC_STATIC) != 0);
582 if (must_be_static != really_is_static) {
583 THROW_0(vmSymbols::java_lang_IllegalArgumentException());
584 }
585 }
586
587 int offset = InstanceKlass::cast(k)->field_offset(slot);
588 return field_offset_from_byte_offset(offset);
589 }
590
591 UNSAFE_ENTRY(jlong, Unsafe_ObjectFieldOffset0(JNIEnv *env, jobject unsafe, jobject field)) {
592 return find_field_offset(field, 0, THREAD);
593 } UNSAFE_END
594
595 UNSAFE_ENTRY(jlong, Unsafe_StaticFieldOffset0(JNIEnv *env, jobject unsafe, jobject field)) {
596 return find_field_offset(field, 1, THREAD);
597 } UNSAFE_END
598
599 UNSAFE_ENTRY(jobject, Unsafe_StaticFieldBase0(JNIEnv *env, jobject unsafe, jobject field)) {
600 assert(field != NULL, "field must not be NULL");
601
602 // Note: In this VM implementation, a field address is always a short
603 // offset from the base of a a klass metaobject. Thus, the full dynamic
604 // range of the return type is never used. However, some implementations
605 // might put the static field inside an array shared by many classes,
606 // or even at a fixed address, in which case the address could be quite
607 // large. In that last case, this function would return NULL, since
608 // the address would operate alone, without any base pointer.
609
610 oop reflected = JNIHandles::resolve_non_null(field);
611 oop mirror = java_lang_reflect_Field::clazz(reflected);
612 int modifiers = java_lang_reflect_Field::modifiers(reflected);
613
614 if ((modifiers & JVM_ACC_STATIC) == 0) {
615 THROW_0(vmSymbols::java_lang_IllegalArgumentException());
616 }
617
618 return JNIHandles::make_local(env, mirror);
619 } UNSAFE_END
620
621 UNSAFE_ENTRY(void, Unsafe_EnsureClassInitialized0(JNIEnv *env, jobject unsafe, jobject clazz)) {
622 assert(clazz != NULL, "clazz must not be NULL");
623
624 oop mirror = JNIHandles::resolve_non_null(clazz);
625
626 Klass* klass = java_lang_Class::as_Klass(mirror);
627 if (klass != NULL && klass->should_be_initialized()) {
628 InstanceKlass* k = InstanceKlass::cast(klass);
629 k->initialize(CHECK);
630 }
631 }
632 UNSAFE_END
633
634 UNSAFE_ENTRY(jboolean, Unsafe_ShouldBeInitialized0(JNIEnv *env, jobject unsafe, jobject clazz)) {
635 assert(clazz != NULL, "clazz must not be NULL");
636
637 oop mirror = JNIHandles::resolve_non_null(clazz);
638 Klass* klass = java_lang_Class::as_Klass(mirror);
639
640 if (klass != NULL && klass->should_be_initialized()) {
641 return true;
642 }
643
644 return false;
645 }
646 UNSAFE_END
647
648 static void getBaseAndScale(int& base, int& scale, jclass clazz, TRAPS) {
649 assert(clazz != NULL, "clazz must not be NULL");
650
651 oop mirror = JNIHandles::resolve_non_null(clazz);
652 Klass* k = java_lang_Class::as_Klass(mirror);
653
654 if (k == NULL || !k->is_array_klass()) {
655 THROW(vmSymbols::java_lang_InvalidClassException());
656 } else if (k->is_objArray_klass()) {
657 base = arrayOopDesc::base_offset_in_bytes(T_OBJECT);
658 scale = heapOopSize;
659 } else if (k->is_typeArray_klass()) {
660 TypeArrayKlass* tak = TypeArrayKlass::cast(k);
661 base = tak->array_header_in_bytes();
662 assert(base == arrayOopDesc::base_offset_in_bytes(tak->element_type()), "array_header_size semantics ok");
663 scale = (1 << tak->log2_element_size());
664 } else {
665 ShouldNotReachHere();
666 }
667 }
668
669 UNSAFE_ENTRY(jint, Unsafe_ArrayBaseOffset0(JNIEnv *env, jobject unsafe, jclass clazz)) {
670 int base = 0, scale = 0;
671 getBaseAndScale(base, scale, clazz, CHECK_0);
672
673 return field_offset_from_byte_offset(base);
674 } UNSAFE_END
675
676
677 UNSAFE_ENTRY(jint, Unsafe_ArrayIndexScale0(JNIEnv *env, jobject unsafe, jclass clazz)) {
678 int base = 0, scale = 0;
679 getBaseAndScale(base, scale, clazz, CHECK_0);
680
681 // This VM packs both fields and array elements down to the byte.
682 // But watch out: If this changes, so that array references for
683 // a given primitive type (say, T_BOOLEAN) use different memory units
684 // than fields, this method MUST return zero for such arrays.
685 // For example, the VM used to store sub-word sized fields in full
686 // words in the object layout, so that accessors like getByte(Object,int)
687 // did not really do what one might expect for arrays. Therefore,
688 // this function used to report a zero scale factor, so that the user
689 // would know not to attempt to access sub-word array elements.
690 // // Code for unpacked fields:
691 // if (scale < wordSize) return 0;
692
693 // The following allows for a pretty general fieldOffset cookie scheme,
694 // but requires it to be linear in byte offset.
695 return field_offset_from_byte_offset(scale) - field_offset_from_byte_offset(0);
696 } UNSAFE_END
697
698
699 static inline void throw_new(JNIEnv *env, const char *ename) {
700 char buf[100];
701
702 jio_snprintf(buf, 100, "%s%s", "java/lang/", ename);
703
704 jclass cls = env->FindClass(buf);
705 if (env->ExceptionCheck()) {
706 env->ExceptionClear();
707 tty->print_cr("Unsafe: cannot throw %s because FindClass has failed", buf);
708 return;
709 }
710
711 env->ThrowNew(cls, NULL);
712 }
713
714 static jclass Unsafe_DefineClass_impl(JNIEnv *env, jstring name, jbyteArray data, int offset, int length, jobject loader, jobject pd) {
715 // Code lifted from JDK 1.3 ClassLoader.c
716
717 jbyte *body;
718 char *utfName = NULL;
719 jclass result = 0;
720 char buf[128];
721
722 assert(data != NULL, "Class bytes must not be NULL");
723 assert(length >= 0, "length must not be negative: %d", length);
724
725 if (UsePerfData) {
726 ClassLoader::unsafe_defineClassCallCounter()->inc();
727 }
728
729 body = NEW_C_HEAP_ARRAY(jbyte, length, mtInternal);
730 if (body == NULL) {
731 throw_new(env, "OutOfMemoryError");
732 return 0;
733 }
734
735 env->GetByteArrayRegion(data, offset, length, body);
736 if (env->ExceptionOccurred()) {
737 goto free_body;
738 }
739
740 if (name != NULL) {
741 uint len = env->GetStringUTFLength(name);
742 int unicode_len = env->GetStringLength(name);
743
744 if (len >= sizeof(buf)) {
745 utfName = NEW_C_HEAP_ARRAY(char, len + 1, mtInternal);
746 if (utfName == NULL) {
747 throw_new(env, "OutOfMemoryError");
748 goto free_body;
749 }
750 } else {
751 utfName = buf;
752 }
753
754 env->GetStringUTFRegion(name, 0, unicode_len, utfName);
755
756 for (uint i = 0; i < len; i++) {
757 if (utfName[i] == '.') utfName[i] = '/';
758 }
759 }
760
761 result = JVM_DefineClass(env, utfName, loader, body, length, pd);
762
763 if (utfName && utfName != buf) {
764 FREE_C_HEAP_ARRAY(char, utfName);
765 }
766
767 free_body:
768 FREE_C_HEAP_ARRAY(jbyte, body);
769 return result;
770 }
771
772
773 UNSAFE_ENTRY(jclass, Unsafe_DefineClass0(JNIEnv *env, jobject unsafe, jstring name, jbyteArray data, int offset, int length, jobject loader, jobject pd)) {
774 ThreadToNativeFromVM ttnfv(thread);
775
776 return Unsafe_DefineClass_impl(env, name, data, offset, length, loader, pd);
777 } UNSAFE_END
778
779
780 // define a class but do not make it known to the class loader or system dictionary
781 // - host_class: supplies context for linkage, access control, protection domain, and class loader
782 // - data: bytes of a class file, a raw memory address (length gives the number of bytes)
783 // - cp_patches: where non-null entries exist, they replace corresponding CP entries in data
784
785 // When you load an anonymous class U, it works as if you changed its name just before loading,
786 // to a name that you will never use again. Since the name is lost, no other class can directly
787 // link to any member of U. Just after U is loaded, the only way to use it is reflectively,
788 // through java.lang.Class methods like Class.newInstance.
789
790 // Access checks for linkage sites within U continue to follow the same rules as for named classes.
791 // The package of an anonymous class is given by the package qualifier on the name under which it was loaded.
792 // An anonymous class also has special privileges to access any member of its host class.
793 // This is the main reason why this loading operation is unsafe. The purpose of this is to
794 // allow language implementations to simulate "open classes"; a host class in effect gets
795 // new code when an anonymous class is loaded alongside it. A less convenient but more
796 // standard way to do this is with reflection, which can also be set to ignore access
797 // restrictions.
798
799 // Access into an anonymous class is possible only through reflection. Therefore, there
800 // are no special access rules for calling into an anonymous class. The relaxed access
801 // rule for the host class is applied in the opposite direction: A host class reflectively
802 // access one of its anonymous classes.
803
804 // If you load the same bytecodes twice, you get two different classes. You can reload
805 // the same bytecodes with or without varying CP patches.
806
807 // By using the CP patching array, you can have a new anonymous class U2 refer to an older one U1.
808 // The bytecodes for U2 should refer to U1 by a symbolic name (doesn't matter what the name is).
809 // The CONSTANT_Class entry for that name can be patched to refer directly to U1.
810
811 // This allows, for example, U2 to use U1 as a superclass or super-interface, or as
812 // an outer class (so that U2 is an anonymous inner class of anonymous U1).
813 // It is not possible for a named class, or an older anonymous class, to refer by
814 // name (via its CP) to a newer anonymous class.
815
816 // CP patching may also be used to modify (i.e., hack) the names of methods, classes,
817 // or type descriptors used in the loaded anonymous class.
818
819 // Finally, CP patching may be used to introduce "live" objects into the constant pool,
820 // instead of "dead" strings. A compiled statement like println((Object)"hello") can
821 // be changed to println(greeting), where greeting is an arbitrary object created before
822 // the anonymous class is loaded. This is useful in dynamic languages, in which
823 // various kinds of metaobjects must be introduced as constants into bytecode.
824 // Note the cast (Object), which tells the verifier to expect an arbitrary object,
825 // not just a literal string. For such ldc instructions, the verifier uses the
826 // type Object instead of String, if the loaded constant is not in fact a String.
827
828 static instanceKlassHandle
829 Unsafe_DefineAnonymousClass_impl(JNIEnv *env,
830 jclass host_class, jbyteArray data, jobjectArray cp_patches_jh,
831 u1** temp_alloc,
832 TRAPS) {
833 assert(host_class != NULL, "host_class must not be NULL");
834 assert(data != NULL, "data must not be NULL");
835
836 if (UsePerfData) {
837 ClassLoader::unsafe_defineClassCallCounter()->inc();
838 }
839
840 jint length = typeArrayOop(JNIHandles::resolve_non_null(data))->length();
841 assert(length >= 0, "class_bytes_length must not be negative: %d", length);
842
843 int class_bytes_length = (int) length;
844
845 u1* class_bytes = NEW_C_HEAP_ARRAY(u1, length, mtInternal);
846 if (class_bytes == NULL) {
847 THROW_0(vmSymbols::java_lang_OutOfMemoryError());
848 }
849
850 // caller responsible to free it:
851 *temp_alloc = class_bytes;
852
853 jbyte* array_base = typeArrayOop(JNIHandles::resolve_non_null(data))->byte_at_addr(0);
854 Copy::conjoint_jbytes(array_base, class_bytes, length);
855
856 objArrayHandle cp_patches_h;
857 if (cp_patches_jh != NULL) {
858 oop p = JNIHandles::resolve_non_null(cp_patches_jh);
859 assert(p->is_objArray(), "cp_patches must be an object[]");
860 cp_patches_h = objArrayHandle(THREAD, (objArrayOop)p);
861 }
862
863 const Klass* host_klass = java_lang_Class::as_Klass(JNIHandles::resolve_non_null(host_class));
864 // Primitive types have NULL Klass* fields in their java.lang.Class instances.
865 if (host_klass == NULL) {
866 THROW_0(vmSymbols::java_lang_IllegalArgumentException());
867 }
868
869 const char* host_source = host_klass->external_name();
870 Handle host_loader(THREAD, host_klass->class_loader());
871 Handle host_domain(THREAD, host_klass->protection_domain());
872
873 GrowableArray<Handle>* cp_patches = NULL;
874
875 if (cp_patches_h.not_null()) {
876 int alen = cp_patches_h->length();
877
878 for (int i = alen-1; i >= 0; i--) {
879 oop p = cp_patches_h->obj_at(i);
880 if (p != NULL) {
881 Handle patch(THREAD, p);
882
883 if (cp_patches == NULL) {
884 cp_patches = new GrowableArray<Handle>(i+1, i+1, Handle());
885 }
886
887 cp_patches->at_put(i, patch);
888 }
889 }
890 }
891
892 ClassFileStream st(class_bytes, class_bytes_length, host_source, ClassFileStream::verify);
893
894 Symbol* no_class_name = NULL;
895 Klass* anonk = SystemDictionary::parse_stream(no_class_name,
896 host_loader,
897 host_domain,
898 &st,
899 host_klass,
900 cp_patches,
901 CHECK_NULL);
902 if (anonk == NULL) {
903 return NULL;
904 }
905
906 return instanceKlassHandle(THREAD, anonk);
907 }
908
909 UNSAFE_ENTRY(jclass, Unsafe_DefineAnonymousClass0(JNIEnv *env, jobject unsafe, jclass host_class, jbyteArray data, jobjectArray cp_patches_jh)) {
910 ResourceMark rm(THREAD);
911
912 instanceKlassHandle anon_klass;
913 jobject res_jh = NULL;
914 u1* temp_alloc = NULL;
915
916 anon_klass = Unsafe_DefineAnonymousClass_impl(env, host_class, data, cp_patches_jh, &temp_alloc, THREAD);
917 if (anon_klass() != NULL) {
918 res_jh = JNIHandles::make_local(env, anon_klass->java_mirror());
919 }
920
921 // try/finally clause:
922 if (temp_alloc != NULL) {
923 FREE_C_HEAP_ARRAY(u1, temp_alloc);
924 }
925
926 // The anonymous class loader data has been artificially been kept alive to
927 // this point. The mirror and any instances of this class have to keep
928 // it alive afterwards.
929 if (anon_klass() != NULL) {
930 anon_klass->class_loader_data()->dec_keep_alive();
931 }
932
933 // let caller initialize it as needed...
934
935 return (jclass) res_jh;
936 } UNSAFE_END
937
938
939
940 UNSAFE_ENTRY(void, Unsafe_ThrowException(JNIEnv *env, jobject unsafe, jthrowable thr)) {
941 ThreadToNativeFromVM ttnfv(thread);
942 env->Throw(thr);
943 } UNSAFE_END
944
945 // JSR166 ------------------------------------------------------------------
946
947 UNSAFE_ENTRY(jobject, Unsafe_CompareAndExchangeObject(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jobject e_h, jobject x_h)) {
948 oop x = JNIHandles::resolve(x_h);
949 oop e = JNIHandles::resolve(e_h);
950 oop p = JNIHandles::resolve(obj);
951 HeapWord* addr = (HeapWord *)index_oop_from_field_offset_long(p, offset);
952 oop res = oopDesc::atomic_compare_exchange_oop(x, addr, e, true);
953 if (res == e) {
954 update_barrier_set((void*)addr, x);
955 }
956 return JNIHandles::make_local(env, res);
957 } UNSAFE_END
958
959 UNSAFE_ENTRY(jint, Unsafe_CompareAndExchangeInt(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jint e, jint x)) {
960 oop p = JNIHandles::resolve(obj);
961 jint* addr = (jint *) index_oop_from_field_offset_long(p, offset);
962
963 return (jint)(Atomic::cmpxchg(x, addr, e));
964 } UNSAFE_END
965
966 UNSAFE_ENTRY(jlong, Unsafe_CompareAndExchangeLong(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jlong e, jlong x)) {
967 Handle p(THREAD, JNIHandles::resolve(obj));
968 jlong* addr = (jlong*)index_oop_from_field_offset_long(p(), offset);
969
970 #ifdef SUPPORTS_NATIVE_CX8
971 return (jlong)(Atomic::cmpxchg(x, addr, e));
972 #else
973 if (VM_Version::supports_cx8()) {
974 return (jlong)(Atomic::cmpxchg(x, addr, e));
975 } else {
976 MutexLockerEx mu(UnsafeJlong_lock, Mutex::_no_safepoint_check_flag);
977
978 jlong val = Atomic::load(addr);
979 if (val == e) {
980 Atomic::store(x, addr);
981 }
982 return val;
983 }
984 #endif
985 } UNSAFE_END
986
987 UNSAFE_ENTRY(jboolean, Unsafe_CompareAndSwapObject(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jobject e_h, jobject x_h)) {
988 oop x = JNIHandles::resolve(x_h);
989 oop e = JNIHandles::resolve(e_h);
990 oop p = JNIHandles::resolve(obj);
991 HeapWord* addr = (HeapWord *)index_oop_from_field_offset_long(p, offset);
992 oop res = oopDesc::atomic_compare_exchange_oop(x, addr, e, true);
993 if (res != e) {
994 return false;
995 }
996
997 update_barrier_set((void*)addr, x);
998
999 return true;
1000 } UNSAFE_END
1001
1002 UNSAFE_ENTRY(jboolean, Unsafe_CompareAndSwapInt(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jint e, jint x)) {
1003 oop p = JNIHandles::resolve(obj);
1004 jint* addr = (jint *)index_oop_from_field_offset_long(p, offset);
1005
1006 return (jint)(Atomic::cmpxchg(x, addr, e)) == e;
1007 } UNSAFE_END
1008
1009 UNSAFE_ENTRY(jboolean, Unsafe_CompareAndSwapLong(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jlong e, jlong x)) {
1010 Handle p(THREAD, JNIHandles::resolve(obj));
1011 jlong* addr = (jlong*)index_oop_from_field_offset_long(p(), offset);
1012
1013 #ifdef SUPPORTS_NATIVE_CX8
1014 return (jlong)(Atomic::cmpxchg(x, addr, e)) == e;
1015 #else
1016 if (VM_Version::supports_cx8()) {
1017 return (jlong)(Atomic::cmpxchg(x, addr, e)) == e;
1018 } else {
1019 MutexLockerEx mu(UnsafeJlong_lock, Mutex::_no_safepoint_check_flag);
1020
1021 jlong val = Atomic::load(addr);
1022 if (val != e) {
1023 return false;
1024 }
1025
1026 Atomic::store(x, addr);
1027 return true;
1028 }
1029 #endif
1030 } UNSAFE_END
1031
1032 UNSAFE_ENTRY(void, Unsafe_Park(JNIEnv *env, jobject unsafe, jboolean isAbsolute, jlong time)) {
1033 EventThreadPark event;
1034 HOTSPOT_THREAD_PARK_BEGIN((uintptr_t) thread->parker(), (int) isAbsolute, time);
1035
1036 JavaThreadParkedState jtps(thread, time != 0);
1037 thread->parker()->park(isAbsolute != 0, time);
1038
1039 HOTSPOT_THREAD_PARK_END((uintptr_t) thread->parker());
1040
1041 if (event.should_commit()) {
1042 oop obj = thread->current_park_blocker();
1043 event.set_klass((obj != NULL) ? obj->klass() : NULL);
1044 event.set_timeout(time);
1045 event.set_address((obj != NULL) ? (TYPE_ADDRESS) cast_from_oop<uintptr_t>(obj) : 0);
1046 event.commit();
1047 }
1048 } UNSAFE_END
1049
1050 UNSAFE_ENTRY(void, Unsafe_Unpark(JNIEnv *env, jobject unsafe, jobject jthread)) {
1051 Parker* p = NULL;
1052
1053 if (jthread != NULL) {
1054 oop java_thread = JNIHandles::resolve_non_null(jthread);
1055 if (java_thread != NULL) {
1056 jlong lp = java_lang_Thread::park_event(java_thread);
1057 if (lp != 0) {
1058 // This cast is OK even though the jlong might have been read
1059 // non-atomically on 32bit systems, since there, one word will
1060 // always be zero anyway and the value set is always the same
1061 p = (Parker*)addr_from_java(lp);
1062 } else {
1063 // Grab lock if apparently null or using older version of library
1064 MutexLocker mu(Threads_lock);
1065 java_thread = JNIHandles::resolve_non_null(jthread);
1066
1067 if (java_thread != NULL) {
1068 JavaThread* thr = java_lang_Thread::thread(java_thread);
1069 if (thr != NULL) {
1070 p = thr->parker();
1071 if (p != NULL) { // Bind to Java thread for next time.
1072 java_lang_Thread::set_park_event(java_thread, addr_to_java(p));
1073 }
1074 }
1075 }
1076 }
1077 }
1078 }
1079
1080 if (p != NULL) {
1081 HOTSPOT_THREAD_UNPARK((uintptr_t) p);
1082 p->unpark();
1083 }
1084 } UNSAFE_END
1085
1086 UNSAFE_ENTRY(jint, Unsafe_GetLoadAverage0(JNIEnv *env, jobject unsafe, jdoubleArray loadavg, jint nelem)) {
1087 const int max_nelem = 3;
1088 double la[max_nelem];
1089 jint ret;
1090
1091 typeArrayOop a = typeArrayOop(JNIHandles::resolve_non_null(loadavg));
1092 assert(a->is_typeArray(), "must be type array");
1093
1094 ret = os::loadavg(la, nelem);
1095 if (ret == -1) {
1096 return -1;
1097 }
1098
1099 // if successful, ret is the number of samples actually retrieved.
1100 assert(ret >= 0 && ret <= max_nelem, "Unexpected loadavg return value");
1101 switch(ret) {
1102 case 3: a->double_at_put(2, (jdouble)la[2]); // fall through
1103 case 2: a->double_at_put(1, (jdouble)la[1]); // fall through
1104 case 1: a->double_at_put(0, (jdouble)la[0]); break;
1105 }
1106
1107 return ret;
1108 } UNSAFE_END
1109
1110
1111 /// JVM_RegisterUnsafeMethods
1112
1113 #define ADR "J"
1114
1115 #define LANG "Ljava/lang/"
1116
1117 #define OBJ LANG "Object;"
1118 #define CLS LANG "Class;"
1119 #define FLD LANG "reflect/Field;"
1120 #define THR LANG "Throwable;"
1121
1122 #define DC_Args LANG "String;[BII" LANG "ClassLoader;" "Ljava/security/ProtectionDomain;"
1123 #define DAC_Args CLS "[B[" OBJ
1124
1125 #define CC (char*) /*cast a literal from (const char*)*/
1126 #define FN_PTR(f) CAST_FROM_FN_PTR(void*, &f)
1127
1128 #define DECLARE_GETPUTOOP(Type, Desc) \
1129 {CC "get" #Type, CC "(" OBJ "J)" #Desc, FN_PTR(Unsafe_Get##Type)}, \
1130 {CC "put" #Type, CC "(" OBJ "J" #Desc ")V", FN_PTR(Unsafe_Put##Type)}, \
1131 {CC "get" #Type "Volatile", CC "(" OBJ "J)" #Desc, FN_PTR(Unsafe_Get##Type##Volatile)}, \
1132 {CC "put" #Type "Volatile", CC "(" OBJ "J" #Desc ")V", FN_PTR(Unsafe_Put##Type##Volatile)}
1133
1134
1135 static JNINativeMethod jdk_internal_misc_Unsafe_methods[] = {
1136 {CC "getObject", CC "(" OBJ "J)" OBJ "", FN_PTR(Unsafe_GetObject)},
1137 {CC "putObject", CC "(" OBJ "J" OBJ ")V", FN_PTR(Unsafe_PutObject)},
1138 {CC "getObjectVolatile",CC "(" OBJ "J)" OBJ "", FN_PTR(Unsafe_GetObjectVolatile)},
1139 {CC "putObjectVolatile",CC "(" OBJ "J" OBJ ")V", FN_PTR(Unsafe_PutObjectVolatile)},
1140
1141 {CC "getUncompressedObject", CC "(" ADR ")" OBJ, FN_PTR(Unsafe_GetUncompressedObject)},
1142
1143 DECLARE_GETPUTOOP(Boolean, Z),
1144 DECLARE_GETPUTOOP(Byte, B),
1145 DECLARE_GETPUTOOP(Short, S),
1146 DECLARE_GETPUTOOP(Char, C),
1147 DECLARE_GETPUTOOP(Int, I),
1148 DECLARE_GETPUTOOP(Long, J),
1149 DECLARE_GETPUTOOP(Float, F),
1150 DECLARE_GETPUTOOP(Double, D),
1151
1152 {CC "allocateMemory0", CC "(J)" ADR, FN_PTR(Unsafe_AllocateMemory0)},
1153 {CC "reallocateMemory0", CC "(" ADR "J)" ADR, FN_PTR(Unsafe_ReallocateMemory0)},
1154 {CC "freeMemory0", CC "(" ADR ")V", FN_PTR(Unsafe_FreeMemory0)},
1155
1156 {CC "objectFieldOffset0", CC "(" FLD ")J", FN_PTR(Unsafe_ObjectFieldOffset0)},
1157 {CC "staticFieldOffset0", CC "(" FLD ")J", FN_PTR(Unsafe_StaticFieldOffset0)},
1158 {CC "staticFieldBase0", CC "(" FLD ")" OBJ, FN_PTR(Unsafe_StaticFieldBase0)},
1159 {CC "ensureClassInitialized0", CC "(" CLS ")V", FN_PTR(Unsafe_EnsureClassInitialized0)},
1160 {CC "arrayBaseOffset0", CC "(" CLS ")I", FN_PTR(Unsafe_ArrayBaseOffset0)},
1161 {CC "arrayIndexScale0", CC "(" CLS ")I", FN_PTR(Unsafe_ArrayIndexScale0)},
1162 {CC "addressSize0", CC "()I", FN_PTR(Unsafe_AddressSize0)},
1163 {CC "pageSize", CC "()I", FN_PTR(Unsafe_PageSize)},
1164
1165 {CC "defineClass0", CC "(" DC_Args ")" CLS, FN_PTR(Unsafe_DefineClass0)},
1166 {CC "allocateInstance", CC "(" CLS ")" OBJ, FN_PTR(Unsafe_AllocateInstance)},
1167 {CC "throwException", CC "(" THR ")V", FN_PTR(Unsafe_ThrowException)},
1168 {CC "compareAndSwapObject", CC "(" OBJ "J" OBJ "" OBJ ")Z", FN_PTR(Unsafe_CompareAndSwapObject)},
1169 {CC "compareAndSwapInt", CC "(" OBJ "J""I""I"")Z", FN_PTR(Unsafe_CompareAndSwapInt)},
1170 {CC "compareAndSwapLong", CC "(" OBJ "J""J""J"")Z", FN_PTR(Unsafe_CompareAndSwapLong)},
1171 {CC "compareAndExchangeObjectVolatile", CC "(" OBJ "J" OBJ "" OBJ ")" OBJ, FN_PTR(Unsafe_CompareAndExchangeObject)},
1172 {CC "compareAndExchangeIntVolatile", CC "(" OBJ "J""I""I"")I", FN_PTR(Unsafe_CompareAndExchangeInt)},
1173 {CC "compareAndExchangeLongVolatile", CC "(" OBJ "J""J""J"")J", FN_PTR(Unsafe_CompareAndExchangeLong)},
1174
1175 {CC "park", CC "(ZJ)V", FN_PTR(Unsafe_Park)},
1176 {CC "unpark", CC "(" OBJ ")V", FN_PTR(Unsafe_Unpark)},
1177
1178 {CC "getLoadAverage0", CC "([DI)I", FN_PTR(Unsafe_GetLoadAverage0)},
1179
1180 {CC "copyMemory0", CC "(" OBJ "J" OBJ "JJ)V", FN_PTR(Unsafe_CopyMemory0)},
1181 {CC "copySwapMemory0", CC "(" OBJ "J" OBJ "JJJ)V", FN_PTR(Unsafe_CopySwapMemory0)},
1182 {CC "setMemory0", CC "(" OBJ "JJB)V", FN_PTR(Unsafe_SetMemory0)},
1183
1184 {CC "defineAnonymousClass0", CC "(" DAC_Args ")" CLS, FN_PTR(Unsafe_DefineAnonymousClass0)},
1185
1186 {CC "shouldBeInitialized0", CC "(" CLS ")Z", FN_PTR(Unsafe_ShouldBeInitialized0)},
1187
1188 {CC "loadFence", CC "()V", FN_PTR(Unsafe_LoadFence)},
1189 {CC "storeFence", CC "()V", FN_PTR(Unsafe_StoreFence)},
1190 {CC "fullFence", CC "()V", FN_PTR(Unsafe_FullFence)},
1191
1192 {CC "isBigEndian0", CC "()Z", FN_PTR(Unsafe_isBigEndian0)},
1193 {CC "unalignedAccess0", CC "()Z", FN_PTR(Unsafe_unalignedAccess0)}
1194 };
1195
1196 #undef CC
1197 #undef FN_PTR
1198
1199 #undef ADR
1200 #undef LANG
1201 #undef OBJ
1202 #undef CLS
1203 #undef FLD
1204 #undef THR
1205 #undef DC_Args
1206 #undef DAC_Args
1207
1208 #undef DECLARE_GETPUTOOP
1209
1210
1211 // This function is exported, used by NativeLookup.
1212 // The Unsafe_xxx functions above are called only from the interpreter.
1213 // The optimizer looks at names and signatures to recognize
1214 // individual functions.
1215
1216 JVM_ENTRY(void, JVM_RegisterJDKInternalMiscUnsafeMethods(JNIEnv *env, jclass unsafeclass)) {
1217 ThreadToNativeFromVM ttnfv(thread);
1218
1219 int ok = env->RegisterNatives(unsafeclass, jdk_internal_misc_Unsafe_methods, sizeof(jdk_internal_misc_Unsafe_methods)/sizeof(JNINativeMethod));
1220 guarantee(ok == 0, "register jdk.internal.misc.Unsafe natives");
1221 } JVM_END