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.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 (support_IRIW_for_not_multiple_copy_atomic_cpu) {
328 OrderAccess::fence();
329 }
330
331 if (UseCompressedOops) {
332 volatile narrowOop n = *(volatile narrowOop*) addr;
333 (void)const_cast<oop&>(v = oopDesc::decode_heap_oop(n));
334 } else {
335 (void)const_cast<oop&>(v = *(volatile oop*) addr);
336 }
337
338 OrderAccess::acquire();
339 return JNIHandles::make_local(env, v);
340 } UNSAFE_END
341
342 UNSAFE_ENTRY(void, Unsafe_PutObjectVolatile(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jobject x_h)) {
343 oop x = JNIHandles::resolve(x_h);
344 oop p = JNIHandles::resolve(obj);
345 void* addr = index_oop_from_field_offset_long(p, offset);
346 OrderAccess::release();
347
348 if (UseCompressedOops) {
349 oop_store((narrowOop*)addr, x);
350 } else {
351 oop_store((oop*)addr, x);
352 }
353
354 OrderAccess::fence();
355 } UNSAFE_END
356
357 UNSAFE_ENTRY(jobject, Unsafe_GetUncompressedObject(JNIEnv *env, jobject unsafe, jlong addr)) {
358 oop v = *(oop*) (address) addr;
359
360 return JNIHandles::make_local(env, v);
361 } UNSAFE_END
362
363 #ifndef SUPPORTS_NATIVE_CX8
364
365 // VM_Version::supports_cx8() is a surrogate for 'supports atomic long memory ops'.
366 //
367 // On platforms which do not support atomic compare-and-swap of jlong (8 byte)
368 // values we have to use a lock-based scheme to enforce atomicity. This has to be
369 // applied to all Unsafe operations that set the value of a jlong field. Even so
370 // the compareAndSwapLong operation will not be atomic with respect to direct stores
371 // to the field from Java code. It is important therefore that any Java code that
372 // utilizes these Unsafe jlong operations does not perform direct stores. To permit
373 // direct loads of the field from Java code we must also use Atomic::store within the
374 // locked regions. And for good measure, in case there are direct stores, we also
375 // employ Atomic::load within those regions. Note that the field in question must be
376 // volatile and so must have atomic load/store accesses applied at the Java level.
377 //
378 // The locking scheme could utilize a range of strategies for controlling the locking
379 // granularity: from a lock per-field through to a single global lock. The latter is
380 // the simplest and is used for the current implementation. Note that the Java object
381 // that contains the field, can not, in general, be used for locking. To do so can lead
382 // to deadlocks as we may introduce locking into what appears to the Java code to be a
383 // lock-free path.
384 //
385 // As all the locked-regions are very short and themselves non-blocking we can treat
386 // them as leaf routines and elide safepoint checks (ie we don't perform any thread
387 // state transitions even when blocking for the lock). Note that if we do choose to
388 // add safepoint checks and thread state transitions, we must ensure that we calculate
389 // the address of the field _after_ we have acquired the lock, else the object may have
390 // been moved by the GC
391
392 UNSAFE_ENTRY(jlong, Unsafe_GetLongVolatile(JNIEnv *env, jobject unsafe, jobject obj, jlong offset)) {
393 if (VM_Version::supports_cx8()) {
394 return MemoryAccess(thread, obj, offset).get_volatile<jlong>();
395 } else {
396 return MemoryAccess(thread, obj, offset).get_jlong_locked();
397 }
398 } UNSAFE_END
399
400 UNSAFE_ENTRY(void, Unsafe_PutLongVolatile(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jlong x)) {
401 if (VM_Version::supports_cx8()) {
402 MemoryAccess(thread, obj, offset).put_volatile<jlong>(x);
403 } else {
404 MemoryAccess(thread, obj, offset).put_jlong_locked(x);
405 }
406 } UNSAFE_END
407
408 #endif // not SUPPORTS_NATIVE_CX8
409
410 UNSAFE_LEAF(jboolean, Unsafe_isBigEndian0(JNIEnv *env, jobject unsafe)) {
411 #ifdef VM_LITTLE_ENDIAN
412 return false;
413 #else
414 return true;
415 #endif
416 } UNSAFE_END
417
418 UNSAFE_LEAF(jint, Unsafe_unalignedAccess0(JNIEnv *env, jobject unsafe)) {
419 return UseUnalignedAccesses;
420 } UNSAFE_END
421
422 #define DEFINE_GETSETOOP(java_type, Type) \
423 \
424 UNSAFE_ENTRY(java_type, Unsafe_Get##Type(JNIEnv *env, jobject unsafe, jobject obj, jlong offset)) { \
425 return MemoryAccess(thread, obj, offset).get<java_type>(); \
426 } UNSAFE_END \
427 \
428 UNSAFE_ENTRY(void, Unsafe_Put##Type(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, java_type x)) { \
429 MemoryAccess(thread, obj, offset).put<java_type>(x); \
430 } UNSAFE_END \
431 \
432 // END DEFINE_GETSETOOP.
433
434 DEFINE_GETSETOOP(jboolean, Boolean)
435 DEFINE_GETSETOOP(jbyte, Byte)
436 DEFINE_GETSETOOP(jshort, Short);
437 DEFINE_GETSETOOP(jchar, Char);
438 DEFINE_GETSETOOP(jint, Int);
439 DEFINE_GETSETOOP(jlong, Long);
440 DEFINE_GETSETOOP(jfloat, Float);
441 DEFINE_GETSETOOP(jdouble, Double);
442
443 #undef DEFINE_GETSETOOP
444
445 #define DEFINE_GETSETOOP_VOLATILE(java_type, Type) \
446 \
447 UNSAFE_ENTRY(java_type, Unsafe_Get##Type##Volatile(JNIEnv *env, jobject unsafe, jobject obj, jlong offset)) { \
448 return MemoryAccess(thread, obj, offset).get_volatile<java_type>(); \
449 } UNSAFE_END \
450 \
451 UNSAFE_ENTRY(void, Unsafe_Put##Type##Volatile(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, java_type x)) { \
452 MemoryAccess(thread, obj, offset).put_volatile<java_type>(x); \
453 } UNSAFE_END \
454 \
455 // END DEFINE_GETSETOOP_VOLATILE.
456
457 DEFINE_GETSETOOP_VOLATILE(jboolean, Boolean)
458 DEFINE_GETSETOOP_VOLATILE(jbyte, Byte)
459 DEFINE_GETSETOOP_VOLATILE(jshort, Short);
460 DEFINE_GETSETOOP_VOLATILE(jchar, Char);
461 DEFINE_GETSETOOP_VOLATILE(jint, Int);
462 DEFINE_GETSETOOP_VOLATILE(jfloat, Float);
463 DEFINE_GETSETOOP_VOLATILE(jdouble, Double);
464
465 #ifdef SUPPORTS_NATIVE_CX8
466 DEFINE_GETSETOOP_VOLATILE(jlong, Long);
467 #endif
468
469 #undef DEFINE_GETSETOOP_VOLATILE
470
471 UNSAFE_LEAF(void, Unsafe_LoadFence(JNIEnv *env, jobject unsafe)) {
472 OrderAccess::acquire();
473 } UNSAFE_END
474
475 UNSAFE_LEAF(void, Unsafe_StoreFence(JNIEnv *env, jobject unsafe)) {
476 OrderAccess::release();
477 } UNSAFE_END
478
479 UNSAFE_LEAF(void, Unsafe_FullFence(JNIEnv *env, jobject unsafe)) {
480 OrderAccess::fence();
481 } UNSAFE_END
482
483 ////// Allocation requests
484
485 UNSAFE_ENTRY(jobject, Unsafe_AllocateInstance(JNIEnv *env, jobject unsafe, jclass cls)) {
486 ThreadToNativeFromVM ttnfv(thread);
487 return env->AllocObject(cls);
488 } UNSAFE_END
489
490 UNSAFE_ENTRY(jlong, Unsafe_AllocateMemory0(JNIEnv *env, jobject unsafe, jlong size)) {
491 size_t sz = (size_t)size;
492
493 sz = round_to(sz, HeapWordSize);
494 void* x = os::malloc(sz, mtInternal);
495
496 return addr_to_java(x);
497 } UNSAFE_END
498
499 UNSAFE_ENTRY(jlong, Unsafe_ReallocateMemory0(JNIEnv *env, jobject unsafe, jlong addr, jlong size)) {
500 void* p = addr_from_java(addr);
501 size_t sz = (size_t)size;
502 sz = round_to(sz, HeapWordSize);
503
504 void* x = os::realloc(p, sz, mtInternal);
505
506 return addr_to_java(x);
507 } UNSAFE_END
508
509 UNSAFE_ENTRY(void, Unsafe_FreeMemory0(JNIEnv *env, jobject unsafe, jlong addr)) {
510 void* p = addr_from_java(addr);
511
512 os::free(p);
513 } UNSAFE_END
514
515 UNSAFE_ENTRY(void, Unsafe_SetMemory0(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jlong size, jbyte value)) {
516 size_t sz = (size_t)size;
517
518 oop base = JNIHandles::resolve(obj);
519 void* p = index_oop_from_field_offset_long(base, offset);
520
521 Copy::fill_to_memory_atomic(p, sz, value);
522 } UNSAFE_END
523
524 UNSAFE_ENTRY(void, Unsafe_CopyMemory0(JNIEnv *env, jobject unsafe, jobject srcObj, jlong srcOffset, jobject dstObj, jlong dstOffset, jlong size)) {
525 size_t sz = (size_t)size;
526
527 oop srcp = JNIHandles::resolve(srcObj);
528 oop dstp = JNIHandles::resolve(dstObj);
529
530 void* src = index_oop_from_field_offset_long(srcp, srcOffset);
531 void* dst = index_oop_from_field_offset_long(dstp, dstOffset);
532
533 Copy::conjoint_memory_atomic(src, dst, sz);
534 } UNSAFE_END
535
536 // This function is a leaf since if the source and destination are both in native memory
537 // the copy may potentially be very large, and we don't want to disable GC if we can avoid it.
538 // If either source or destination (or both) are on the heap, the function will enter VM using
539 // JVM_ENTRY_FROM_LEAF
540 UNSAFE_LEAF(void, Unsafe_CopySwapMemory0(JNIEnv *env, jobject unsafe, jobject srcObj, jlong srcOffset, jobject dstObj, jlong dstOffset, jlong size, jlong elemSize)) {
541 size_t sz = (size_t)size;
542 size_t esz = (size_t)elemSize;
543
544 if (srcObj == NULL && dstObj == NULL) {
545 // Both src & dst are in native memory
546 address src = (address)srcOffset;
547 address dst = (address)dstOffset;
548
549 Copy::conjoint_swap(src, dst, sz, esz);
550 } else {
551 // At least one of src/dst are on heap, transition to VM to access raw pointers
552
553 JVM_ENTRY_FROM_LEAF(env, void, Unsafe_CopySwapMemory0) {
554 oop srcp = JNIHandles::resolve(srcObj);
555 oop dstp = JNIHandles::resolve(dstObj);
556
557 address src = (address)index_oop_from_field_offset_long(srcp, srcOffset);
558 address dst = (address)index_oop_from_field_offset_long(dstp, dstOffset);
559
560 Copy::conjoint_swap(src, dst, sz, esz);
561 } JVM_END
562 }
563 } UNSAFE_END
564
565 ////// Random queries
566
567 UNSAFE_LEAF(jint, Unsafe_AddressSize0(JNIEnv *env, jobject unsafe)) {
568 return sizeof(void*);
569 } UNSAFE_END
570
571 UNSAFE_LEAF(jint, Unsafe_PageSize()) {
572 return os::vm_page_size();
573 } UNSAFE_END
574
575 static jint find_field_offset(jobject field, int must_be_static, TRAPS) {
576 assert(field != NULL, "field must not be NULL");
577
578 oop reflected = JNIHandles::resolve_non_null(field);
579 oop mirror = java_lang_reflect_Field::clazz(reflected);
580 Klass* k = java_lang_Class::as_Klass(mirror);
581 int slot = java_lang_reflect_Field::slot(reflected);
582 int modifiers = java_lang_reflect_Field::modifiers(reflected);
583
584 if (must_be_static >= 0) {
585 int really_is_static = ((modifiers & JVM_ACC_STATIC) != 0);
586 if (must_be_static != really_is_static) {
587 THROW_0(vmSymbols::java_lang_IllegalArgumentException());
588 }
589 }
590
591 int offset = InstanceKlass::cast(k)->field_offset(slot);
592 return field_offset_from_byte_offset(offset);
593 }
594
595 UNSAFE_ENTRY(jlong, Unsafe_ObjectFieldOffset0(JNIEnv *env, jobject unsafe, jobject field)) {
596 return find_field_offset(field, 0, THREAD);
597 } UNSAFE_END
598
599 UNSAFE_ENTRY(jlong, Unsafe_StaticFieldOffset0(JNIEnv *env, jobject unsafe, jobject field)) {
600 return find_field_offset(field, 1, THREAD);
601 } UNSAFE_END
602
603 UNSAFE_ENTRY(jobject, Unsafe_StaticFieldBase0(JNIEnv *env, jobject unsafe, jobject field)) {
604 assert(field != NULL, "field must not be NULL");
605
606 // Note: In this VM implementation, a field address is always a short
607 // offset from the base of a a klass metaobject. Thus, the full dynamic
608 // range of the return type is never used. However, some implementations
609 // might put the static field inside an array shared by many classes,
610 // or even at a fixed address, in which case the address could be quite
611 // large. In that last case, this function would return NULL, since
612 // the address would operate alone, without any base pointer.
613
614 oop reflected = JNIHandles::resolve_non_null(field);
615 oop mirror = java_lang_reflect_Field::clazz(reflected);
616 int modifiers = java_lang_reflect_Field::modifiers(reflected);
617
618 if ((modifiers & JVM_ACC_STATIC) == 0) {
619 THROW_0(vmSymbols::java_lang_IllegalArgumentException());
620 }
621
622 return JNIHandles::make_local(env, mirror);
623 } UNSAFE_END
624
625 UNSAFE_ENTRY(void, Unsafe_EnsureClassInitialized0(JNIEnv *env, jobject unsafe, jobject clazz)) {
626 assert(clazz != NULL, "clazz must not be NULL");
627
628 oop mirror = JNIHandles::resolve_non_null(clazz);
629
630 Klass* klass = java_lang_Class::as_Klass(mirror);
631 if (klass != NULL && klass->should_be_initialized()) {
632 InstanceKlass* k = InstanceKlass::cast(klass);
633 k->initialize(CHECK);
634 }
635 }
636 UNSAFE_END
637
638 UNSAFE_ENTRY(jboolean, Unsafe_ShouldBeInitialized0(JNIEnv *env, jobject unsafe, jobject clazz)) {
639 assert(clazz != NULL, "clazz must not be NULL");
640
641 oop mirror = JNIHandles::resolve_non_null(clazz);
642 Klass* klass = java_lang_Class::as_Klass(mirror);
643
644 if (klass != NULL && klass->should_be_initialized()) {
645 return true;
646 }
647
648 return false;
649 }
650 UNSAFE_END
651
652 static void getBaseAndScale(int& base, int& scale, jclass clazz, TRAPS) {
653 assert(clazz != NULL, "clazz must not be NULL");
654
655 oop mirror = JNIHandles::resolve_non_null(clazz);
656 Klass* k = java_lang_Class::as_Klass(mirror);
657
658 if (k == NULL || !k->is_array_klass()) {
659 THROW(vmSymbols::java_lang_InvalidClassException());
660 } else if (k->is_objArray_klass()) {
661 base = arrayOopDesc::base_offset_in_bytes(T_OBJECT);
662 scale = heapOopSize;
663 } else if (k->is_typeArray_klass()) {
664 TypeArrayKlass* tak = TypeArrayKlass::cast(k);
665 base = tak->array_header_in_bytes();
666 assert(base == arrayOopDesc::base_offset_in_bytes(tak->element_type()), "array_header_size semantics ok");
667 scale = (1 << tak->log2_element_size());
668 } else {
669 ShouldNotReachHere();
670 }
671 }
672
673 UNSAFE_ENTRY(jint, Unsafe_ArrayBaseOffset0(JNIEnv *env, jobject unsafe, jclass clazz)) {
674 int base = 0, scale = 0;
675 getBaseAndScale(base, scale, clazz, CHECK_0);
676
677 return field_offset_from_byte_offset(base);
678 } UNSAFE_END
679
680
681 UNSAFE_ENTRY(jint, Unsafe_ArrayIndexScale0(JNIEnv *env, jobject unsafe, jclass clazz)) {
682 int base = 0, scale = 0;
683 getBaseAndScale(base, scale, clazz, CHECK_0);
684
685 // This VM packs both fields and array elements down to the byte.
686 // But watch out: If this changes, so that array references for
687 // a given primitive type (say, T_BOOLEAN) use different memory units
688 // than fields, this method MUST return zero for such arrays.
689 // For example, the VM used to store sub-word sized fields in full
690 // words in the object layout, so that accessors like getByte(Object,int)
691 // did not really do what one might expect for arrays. Therefore,
692 // this function used to report a zero scale factor, so that the user
693 // would know not to attempt to access sub-word array elements.
694 // // Code for unpacked fields:
695 // if (scale < wordSize) return 0;
696
697 // The following allows for a pretty general fieldOffset cookie scheme,
698 // but requires it to be linear in byte offset.
699 return field_offset_from_byte_offset(scale) - field_offset_from_byte_offset(0);
700 } UNSAFE_END
701
702
703 static inline void throw_new(JNIEnv *env, const char *ename) {
704 char buf[100];
705
706 jio_snprintf(buf, 100, "%s%s", "java/lang/", ename);
707
708 jclass cls = env->FindClass(buf);
709 if (env->ExceptionCheck()) {
710 env->ExceptionClear();
711 tty->print_cr("Unsafe: cannot throw %s because FindClass has failed", buf);
712 return;
713 }
714
715 env->ThrowNew(cls, NULL);
716 }
717
718 static jclass Unsafe_DefineClass_impl(JNIEnv *env, jstring name, jbyteArray data, int offset, int length, jobject loader, jobject pd) {
719 // Code lifted from JDK 1.3 ClassLoader.c
720
721 jbyte *body;
722 char *utfName = NULL;
723 jclass result = 0;
724 char buf[128];
725
726 assert(data != NULL, "Class bytes must not be NULL");
727 assert(length >= 0, "length must not be negative: %d", length);
728
729 if (UsePerfData) {
730 ClassLoader::unsafe_defineClassCallCounter()->inc();
731 }
732
733 body = NEW_C_HEAP_ARRAY(jbyte, length, mtInternal);
734 if (body == NULL) {
735 throw_new(env, "OutOfMemoryError");
736 return 0;
737 }
738
739 env->GetByteArrayRegion(data, offset, length, body);
740 if (env->ExceptionOccurred()) {
741 goto free_body;
742 }
743
744 if (name != NULL) {
745 uint len = env->GetStringUTFLength(name);
746 int unicode_len = env->GetStringLength(name);
747
748 if (len >= sizeof(buf)) {
749 utfName = NEW_C_HEAP_ARRAY(char, len + 1, mtInternal);
750 if (utfName == NULL) {
751 throw_new(env, "OutOfMemoryError");
752 goto free_body;
753 }
754 } else {
755 utfName = buf;
756 }
757
758 env->GetStringUTFRegion(name, 0, unicode_len, utfName);
759
760 for (uint i = 0; i < len; i++) {
761 if (utfName[i] == '.') utfName[i] = '/';
762 }
763 }
764
765 result = JVM_DefineClass(env, utfName, loader, body, length, pd);
766
767 if (utfName && utfName != buf) {
768 FREE_C_HEAP_ARRAY(char, utfName);
769 }
770
771 free_body:
772 FREE_C_HEAP_ARRAY(jbyte, body);
773 return result;
774 }
775
776
777 UNSAFE_ENTRY(jclass, Unsafe_DefineClass0(JNIEnv *env, jobject unsafe, jstring name, jbyteArray data, int offset, int length, jobject loader, jobject pd)) {
778 ThreadToNativeFromVM ttnfv(thread);
779
780 return Unsafe_DefineClass_impl(env, name, data, offset, length, loader, pd);
781 } UNSAFE_END
782
783
784 // define a class but do not make it known to the class loader or system dictionary
785 // - host_class: supplies context for linkage, access control, protection domain, and class loader
786 // - data: bytes of a class file, a raw memory address (length gives the number of bytes)
787 // - cp_patches: where non-null entries exist, they replace corresponding CP entries in data
788
789 // When you load an anonymous class U, it works as if you changed its name just before loading,
790 // to a name that you will never use again. Since the name is lost, no other class can directly
791 // link to any member of U. Just after U is loaded, the only way to use it is reflectively,
792 // through java.lang.Class methods like Class.newInstance.
793
794 // Access checks for linkage sites within U continue to follow the same rules as for named classes.
795 // The package of an anonymous class is given by the package qualifier on the name under which it was loaded.
796 // An anonymous class also has special privileges to access any member of its host class.
797 // This is the main reason why this loading operation is unsafe. The purpose of this is to
798 // allow language implementations to simulate "open classes"; a host class in effect gets
799 // new code when an anonymous class is loaded alongside it. A less convenient but more
800 // standard way to do this is with reflection, which can also be set to ignore access
801 // restrictions.
802
803 // Access into an anonymous class is possible only through reflection. Therefore, there
804 // are no special access rules for calling into an anonymous class. The relaxed access
805 // rule for the host class is applied in the opposite direction: A host class reflectively
806 // access one of its anonymous classes.
807
808 // If you load the same bytecodes twice, you get two different classes. You can reload
809 // the same bytecodes with or without varying CP patches.
810
811 // By using the CP patching array, you can have a new anonymous class U2 refer to an older one U1.
812 // The bytecodes for U2 should refer to U1 by a symbolic name (doesn't matter what the name is).
813 // The CONSTANT_Class entry for that name can be patched to refer directly to U1.
814
815 // This allows, for example, U2 to use U1 as a superclass or super-interface, or as
816 // an outer class (so that U2 is an anonymous inner class of anonymous U1).
817 // It is not possible for a named class, or an older anonymous class, to refer by
818 // name (via its CP) to a newer anonymous class.
819
820 // CP patching may also be used to modify (i.e., hack) the names of methods, classes,
821 // or type descriptors used in the loaded anonymous class.
822
823 // Finally, CP patching may be used to introduce "live" objects into the constant pool,
824 // instead of "dead" strings. A compiled statement like println((Object)"hello") can
825 // be changed to println(greeting), where greeting is an arbitrary object created before
826 // the anonymous class is loaded. This is useful in dynamic languages, in which
827 // various kinds of metaobjects must be introduced as constants into bytecode.
828 // Note the cast (Object), which tells the verifier to expect an arbitrary object,
829 // not just a literal string. For such ldc instructions, the verifier uses the
830 // type Object instead of String, if the loaded constant is not in fact a String.
831
832 static instanceKlassHandle
833 Unsafe_DefineAnonymousClass_impl(JNIEnv *env,
834 jclass host_class, jbyteArray data, jobjectArray cp_patches_jh,
835 u1** temp_alloc,
836 TRAPS) {
837 assert(host_class != NULL, "host_class must not be NULL");
838 assert(data != NULL, "data must not be NULL");
839
840 if (UsePerfData) {
841 ClassLoader::unsafe_defineClassCallCounter()->inc();
842 }
843
844 jint length = typeArrayOop(JNIHandles::resolve_non_null(data))->length();
845 assert(length >= 0, "class_bytes_length must not be negative: %d", length);
846
847 int class_bytes_length = (int) length;
848
849 u1* class_bytes = NEW_C_HEAP_ARRAY(u1, length, mtInternal);
850 if (class_bytes == NULL) {
851 THROW_0(vmSymbols::java_lang_OutOfMemoryError());
852 }
853
854 // caller responsible to free it:
855 *temp_alloc = class_bytes;
856
857 jbyte* array_base = typeArrayOop(JNIHandles::resolve_non_null(data))->byte_at_addr(0);
858 Copy::conjoint_jbytes(array_base, class_bytes, length);
859
860 objArrayHandle cp_patches_h;
861 if (cp_patches_jh != NULL) {
862 oop p = JNIHandles::resolve_non_null(cp_patches_jh);
863 assert(p->is_objArray(), "cp_patches must be an object[]");
864 cp_patches_h = objArrayHandle(THREAD, (objArrayOop)p);
865 }
866
867 const Klass* host_klass = java_lang_Class::as_Klass(JNIHandles::resolve_non_null(host_class));
868
869 // Make sure it's the real host class, not another anonymous class.
870 while (host_klass != NULL && host_klass->is_instance_klass() &&
871 InstanceKlass::cast(host_klass)->is_anonymous()) {
872 host_klass = InstanceKlass::cast(host_klass)->host_klass();
873 }
874
875 // Primitive types have NULL Klass* fields in their java.lang.Class instances.
876 if (host_klass == NULL) {
877 THROW_0(vmSymbols::java_lang_IllegalArgumentException());
878 }
879
880 const char* host_source = host_klass->external_name();
881 Handle host_loader(THREAD, host_klass->class_loader());
882 Handle host_domain(THREAD, host_klass->protection_domain());
883
884 GrowableArray<Handle>* cp_patches = NULL;
885
886 if (cp_patches_h.not_null()) {
887 int alen = cp_patches_h->length();
888
889 for (int i = alen-1; i >= 0; i--) {
890 oop p = cp_patches_h->obj_at(i);
891 if (p != NULL) {
892 Handle patch(THREAD, p);
893
894 if (cp_patches == NULL) {
895 cp_patches = new GrowableArray<Handle>(i+1, i+1, Handle());
896 }
897
898 cp_patches->at_put(i, patch);
899 }
900 }
901 }
902
903 ClassFileStream st(class_bytes, class_bytes_length, host_source, ClassFileStream::verify);
904
905 Symbol* no_class_name = NULL;
906 Klass* anonk = SystemDictionary::parse_stream(no_class_name,
907 host_loader,
908 host_domain,
909 &st,
910 host_klass,
911 cp_patches,
912 CHECK_NULL);
913 if (anonk == NULL) {
914 return NULL;
915 }
916
917 return instanceKlassHandle(THREAD, anonk);
918 }
919
920 UNSAFE_ENTRY(jclass, Unsafe_DefineAnonymousClass0(JNIEnv *env, jobject unsafe, jclass host_class, jbyteArray data, jobjectArray cp_patches_jh)) {
921 ResourceMark rm(THREAD);
922
923 instanceKlassHandle anon_klass;
924 jobject res_jh = NULL;
925 u1* temp_alloc = NULL;
926
927 anon_klass = Unsafe_DefineAnonymousClass_impl(env, host_class, data, cp_patches_jh, &temp_alloc, THREAD);
928 if (anon_klass() != NULL) {
929 res_jh = JNIHandles::make_local(env, anon_klass->java_mirror());
930 }
931
932 // try/finally clause:
933 if (temp_alloc != NULL) {
934 FREE_C_HEAP_ARRAY(u1, temp_alloc);
935 }
936
937 // The anonymous class loader data has been artificially been kept alive to
938 // this point. The mirror and any instances of this class have to keep
939 // it alive afterwards.
940 if (anon_klass() != NULL) {
941 anon_klass->class_loader_data()->dec_keep_alive();
942 }
943
944 // let caller initialize it as needed...
945
946 return (jclass) res_jh;
947 } UNSAFE_END
948
949
950
951 UNSAFE_ENTRY(void, Unsafe_ThrowException(JNIEnv *env, jobject unsafe, jthrowable thr)) {
952 ThreadToNativeFromVM ttnfv(thread);
953 env->Throw(thr);
954 } UNSAFE_END
955
956 // JSR166 ------------------------------------------------------------------
957
958 UNSAFE_ENTRY(jobject, Unsafe_CompareAndExchangeObject(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jobject e_h, jobject x_h)) {
959 oop x = JNIHandles::resolve(x_h);
960 oop e = JNIHandles::resolve(e_h);
961 oop p = JNIHandles::resolve(obj);
962 HeapWord* addr = (HeapWord *)index_oop_from_field_offset_long(p, offset);
963 oop res = oopDesc::atomic_compare_exchange_oop(x, addr, e, true);
964 if (res == e) {
965 update_barrier_set((void*)addr, x);
966 }
967 return JNIHandles::make_local(env, res);
968 } UNSAFE_END
969
970 UNSAFE_ENTRY(jint, Unsafe_CompareAndExchangeInt(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jint e, jint x)) {
971 oop p = JNIHandles::resolve(obj);
972 jint* addr = (jint *) index_oop_from_field_offset_long(p, offset);
973
974 return (jint)(Atomic::cmpxchg(x, addr, e));
975 } UNSAFE_END
976
977 UNSAFE_ENTRY(jlong, Unsafe_CompareAndExchangeLong(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jlong e, jlong x)) {
978 Handle p(THREAD, JNIHandles::resolve(obj));
979 jlong* addr = (jlong*)index_oop_from_field_offset_long(p(), offset);
980
981 #ifdef SUPPORTS_NATIVE_CX8
982 return (jlong)(Atomic::cmpxchg(x, addr, e));
983 #else
984 if (VM_Version::supports_cx8()) {
985 return (jlong)(Atomic::cmpxchg(x, addr, e));
986 } else {
987 MutexLockerEx mu(UnsafeJlong_lock, Mutex::_no_safepoint_check_flag);
988
989 jlong val = Atomic::load(addr);
990 if (val == e) {
991 Atomic::store(x, addr);
992 }
993 return val;
994 }
995 #endif
996 } UNSAFE_END
997
998 UNSAFE_ENTRY(jboolean, Unsafe_CompareAndSwapObject(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jobject e_h, jobject x_h)) {
999 oop x = JNIHandles::resolve(x_h);
1000 oop e = JNIHandles::resolve(e_h);
1001 oop p = JNIHandles::resolve(obj);
1002 HeapWord* addr = (HeapWord *)index_oop_from_field_offset_long(p, offset);
1003 oop res = oopDesc::atomic_compare_exchange_oop(x, addr, e, true);
1004 if (res != e) {
1005 return false;
1006 }
1007
1008 update_barrier_set((void*)addr, x);
1009
1010 return true;
1011 } UNSAFE_END
1012
1013 UNSAFE_ENTRY(jboolean, Unsafe_CompareAndSwapInt(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jint e, jint x)) {
1014 oop p = JNIHandles::resolve(obj);
1015 jint* addr = (jint *)index_oop_from_field_offset_long(p, offset);
1016
1017 return (jint)(Atomic::cmpxchg(x, addr, e)) == e;
1018 } UNSAFE_END
1019
1020 UNSAFE_ENTRY(jboolean, Unsafe_CompareAndSwapLong(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jlong e, jlong x)) {
1021 Handle p(THREAD, JNIHandles::resolve(obj));
1022 jlong* addr = (jlong*)index_oop_from_field_offset_long(p(), offset);
1023
1024 #ifdef SUPPORTS_NATIVE_CX8
1025 return (jlong)(Atomic::cmpxchg(x, addr, e)) == e;
1026 #else
1027 if (VM_Version::supports_cx8()) {
1028 return (jlong)(Atomic::cmpxchg(x, addr, e)) == e;
1029 } else {
1030 MutexLockerEx mu(UnsafeJlong_lock, Mutex::_no_safepoint_check_flag);
1031
1032 jlong val = Atomic::load(addr);
1033 if (val != e) {
1034 return false;
1035 }
1036
1037 Atomic::store(x, addr);
1038 return true;
1039 }
1040 #endif
1041 } UNSAFE_END
1042
1043 UNSAFE_ENTRY(void, Unsafe_Park(JNIEnv *env, jobject unsafe, jboolean isAbsolute, jlong time)) {
1044 EventThreadPark event;
1045 HOTSPOT_THREAD_PARK_BEGIN((uintptr_t) thread->parker(), (int) isAbsolute, time);
1046
1047 JavaThreadParkedState jtps(thread, time != 0);
1048 thread->parker()->park(isAbsolute != 0, time);
1049
1050 HOTSPOT_THREAD_PARK_END((uintptr_t) thread->parker());
1051
1052 if (event.should_commit()) {
1053 oop obj = thread->current_park_blocker();
1054 event.set_parkedClass((obj != NULL) ? obj->klass() : NULL);
1055 event.set_timeout(time);
1056 event.set_address((obj != NULL) ? (TYPE_ADDRESS) cast_from_oop<uintptr_t>(obj) : 0);
1057 event.commit();
1058 }
1059 } UNSAFE_END
1060
1061 UNSAFE_ENTRY(void, Unsafe_Unpark(JNIEnv *env, jobject unsafe, jobject jthread)) {
1062 Parker* p = NULL;
1063
1064 if (jthread != NULL) {
1065 oop java_thread = JNIHandles::resolve_non_null(jthread);
1066 if (java_thread != NULL) {
1067 jlong lp = java_lang_Thread::park_event(java_thread);
1068 if (lp != 0) {
1069 // This cast is OK even though the jlong might have been read
1070 // non-atomically on 32bit systems, since there, one word will
1071 // always be zero anyway and the value set is always the same
1072 p = (Parker*)addr_from_java(lp);
1073 } else {
1074 // Grab lock if apparently null or using older version of library
1075 MutexLocker mu(Threads_lock);
1076 java_thread = JNIHandles::resolve_non_null(jthread);
1077
1078 if (java_thread != NULL) {
1079 JavaThread* thr = java_lang_Thread::thread(java_thread);
1080 if (thr != NULL) {
1081 p = thr->parker();
1082 if (p != NULL) { // Bind to Java thread for next time.
1083 java_lang_Thread::set_park_event(java_thread, addr_to_java(p));
1084 }
1085 }
1086 }
1087 }
1088 }
1089 }
1090
1091 if (p != NULL) {
1092 HOTSPOT_THREAD_UNPARK((uintptr_t) p);
1093 p->unpark();
1094 }
1095 } UNSAFE_END
1096
1097 UNSAFE_ENTRY(jint, Unsafe_GetLoadAverage0(JNIEnv *env, jobject unsafe, jdoubleArray loadavg, jint nelem)) {
1098 const int max_nelem = 3;
1099 double la[max_nelem];
1100 jint ret;
1101
1102 typeArrayOop a = typeArrayOop(JNIHandles::resolve_non_null(loadavg));
1103 assert(a->is_typeArray(), "must be type array");
1104
1105 ret = os::loadavg(la, nelem);
1106 if (ret == -1) {
1107 return -1;
1108 }
1109
1110 // if successful, ret is the number of samples actually retrieved.
1111 assert(ret >= 0 && ret <= max_nelem, "Unexpected loadavg return value");
1112 switch(ret) {
1113 case 3: a->double_at_put(2, (jdouble)la[2]); // fall through
1114 case 2: a->double_at_put(1, (jdouble)la[1]); // fall through
1115 case 1: a->double_at_put(0, (jdouble)la[0]); break;
1116 }
1117
1118 return ret;
1119 } UNSAFE_END
1120
1121
1122 /// JVM_RegisterUnsafeMethods
1123
1124 #define ADR "J"
1125
1126 #define LANG "Ljava/lang/"
1127
1128 #define OBJ LANG "Object;"
1129 #define CLS LANG "Class;"
1130 #define FLD LANG "reflect/Field;"
1131 #define THR LANG "Throwable;"
1132
1133 #define DC_Args LANG "String;[BII" LANG "ClassLoader;" "Ljava/security/ProtectionDomain;"
1134 #define DAC_Args CLS "[B[" OBJ
1135
1136 #define CC (char*) /*cast a literal from (const char*)*/
1137 #define FN_PTR(f) CAST_FROM_FN_PTR(void*, &f)
1138
1139 #define DECLARE_GETPUTOOP(Type, Desc) \
1140 {CC "get" #Type, CC "(" OBJ "J)" #Desc, FN_PTR(Unsafe_Get##Type)}, \
1141 {CC "put" #Type, CC "(" OBJ "J" #Desc ")V", FN_PTR(Unsafe_Put##Type)}, \
1142 {CC "get" #Type "Volatile", CC "(" OBJ "J)" #Desc, FN_PTR(Unsafe_Get##Type##Volatile)}, \
1143 {CC "put" #Type "Volatile", CC "(" OBJ "J" #Desc ")V", FN_PTR(Unsafe_Put##Type##Volatile)}
1144
1145
1146 static JNINativeMethod jdk_internal_misc_Unsafe_methods[] = {
1147 {CC "getObject", CC "(" OBJ "J)" OBJ "", FN_PTR(Unsafe_GetObject)},
1148 {CC "putObject", CC "(" OBJ "J" OBJ ")V", FN_PTR(Unsafe_PutObject)},
1149 {CC "getObjectVolatile",CC "(" OBJ "J)" OBJ "", FN_PTR(Unsafe_GetObjectVolatile)},
1150 {CC "putObjectVolatile",CC "(" OBJ "J" OBJ ")V", FN_PTR(Unsafe_PutObjectVolatile)},
1151
1152 {CC "getUncompressedObject", CC "(" ADR ")" OBJ, FN_PTR(Unsafe_GetUncompressedObject)},
1153
1154 DECLARE_GETPUTOOP(Boolean, Z),
1155 DECLARE_GETPUTOOP(Byte, B),
1156 DECLARE_GETPUTOOP(Short, S),
1157 DECLARE_GETPUTOOP(Char, C),
1158 DECLARE_GETPUTOOP(Int, I),
1159 DECLARE_GETPUTOOP(Long, J),
1160 DECLARE_GETPUTOOP(Float, F),
1161 DECLARE_GETPUTOOP(Double, D),
1162
1163 {CC "allocateMemory0", CC "(J)" ADR, FN_PTR(Unsafe_AllocateMemory0)},
1164 {CC "reallocateMemory0", CC "(" ADR "J)" ADR, FN_PTR(Unsafe_ReallocateMemory0)},
1165 {CC "freeMemory0", CC "(" ADR ")V", FN_PTR(Unsafe_FreeMemory0)},
1166
1167 {CC "objectFieldOffset0", CC "(" FLD ")J", FN_PTR(Unsafe_ObjectFieldOffset0)},
1168 {CC "staticFieldOffset0", CC "(" FLD ")J", FN_PTR(Unsafe_StaticFieldOffset0)},
1169 {CC "staticFieldBase0", CC "(" FLD ")" OBJ, FN_PTR(Unsafe_StaticFieldBase0)},
1170 {CC "ensureClassInitialized0", CC "(" CLS ")V", FN_PTR(Unsafe_EnsureClassInitialized0)},
1171 {CC "arrayBaseOffset0", CC "(" CLS ")I", FN_PTR(Unsafe_ArrayBaseOffset0)},
1172 {CC "arrayIndexScale0", CC "(" CLS ")I", FN_PTR(Unsafe_ArrayIndexScale0)},
1173 {CC "addressSize0", CC "()I", FN_PTR(Unsafe_AddressSize0)},
1174 {CC "pageSize", CC "()I", FN_PTR(Unsafe_PageSize)},
1175
1176 {CC "defineClass0", CC "(" DC_Args ")" CLS, FN_PTR(Unsafe_DefineClass0)},
1177 {CC "allocateInstance", CC "(" CLS ")" OBJ, FN_PTR(Unsafe_AllocateInstance)},
1178 {CC "throwException", CC "(" THR ")V", FN_PTR(Unsafe_ThrowException)},
1179 {CC "compareAndSwapObject", CC "(" OBJ "J" OBJ "" OBJ ")Z", FN_PTR(Unsafe_CompareAndSwapObject)},
1180 {CC "compareAndSwapInt", CC "(" OBJ "J""I""I"")Z", FN_PTR(Unsafe_CompareAndSwapInt)},
1181 {CC "compareAndSwapLong", CC "(" OBJ "J""J""J"")Z", FN_PTR(Unsafe_CompareAndSwapLong)},
1182 {CC "compareAndExchangeObjectVolatile", CC "(" OBJ "J" OBJ "" OBJ ")" OBJ, FN_PTR(Unsafe_CompareAndExchangeObject)},
1183 {CC "compareAndExchangeIntVolatile", CC "(" OBJ "J""I""I"")I", FN_PTR(Unsafe_CompareAndExchangeInt)},
1184 {CC "compareAndExchangeLongVolatile", CC "(" OBJ "J""J""J"")J", FN_PTR(Unsafe_CompareAndExchangeLong)},
1185
1186 {CC "park", CC "(ZJ)V", FN_PTR(Unsafe_Park)},
1187 {CC "unpark", CC "(" OBJ ")V", FN_PTR(Unsafe_Unpark)},
1188
1189 {CC "getLoadAverage0", CC "([DI)I", FN_PTR(Unsafe_GetLoadAverage0)},
1190
1191 {CC "copyMemory0", CC "(" OBJ "J" OBJ "JJ)V", FN_PTR(Unsafe_CopyMemory0)},
1192 {CC "copySwapMemory0", CC "(" OBJ "J" OBJ "JJJ)V", FN_PTR(Unsafe_CopySwapMemory0)},
1193 {CC "setMemory0", CC "(" OBJ "JJB)V", FN_PTR(Unsafe_SetMemory0)},
1194
1195 {CC "defineAnonymousClass0", CC "(" DAC_Args ")" CLS, FN_PTR(Unsafe_DefineAnonymousClass0)},
1196
1197 {CC "shouldBeInitialized0", CC "(" CLS ")Z", FN_PTR(Unsafe_ShouldBeInitialized0)},
1198
1199 {CC "loadFence", CC "()V", FN_PTR(Unsafe_LoadFence)},
1200 {CC "storeFence", CC "()V", FN_PTR(Unsafe_StoreFence)},
1201 {CC "fullFence", CC "()V", FN_PTR(Unsafe_FullFence)},
1202
1203 {CC "isBigEndian0", CC "()Z", FN_PTR(Unsafe_isBigEndian0)},
1204 {CC "unalignedAccess0", CC "()Z", FN_PTR(Unsafe_unalignedAccess0)}
1205 };
1206
1207 #undef CC
1208 #undef FN_PTR
1209
1210 #undef ADR
1211 #undef LANG
1212 #undef OBJ
1213 #undef CLS
1214 #undef FLD
1215 #undef THR
1216 #undef DC_Args
1217 #undef DAC_Args
1218
1219 #undef DECLARE_GETPUTOOP
1220
1221
1222 // This function is exported, used by NativeLookup.
1223 // The Unsafe_xxx functions above are called only from the interpreter.
1224 // The optimizer looks at names and signatures to recognize
1225 // individual functions.
1226
1227 JVM_ENTRY(void, JVM_RegisterJDKInternalMiscUnsafeMethods(JNIEnv *env, jclass unsafeclass)) {
1228 ThreadToNativeFromVM ttnfv(thread);
1229
1230 int ok = env->RegisterNatives(unsafeclass, jdk_internal_misc_Unsafe_methods, sizeof(jdk_internal_misc_Unsafe_methods)/sizeof(JNINativeMethod));
1231 guarantee(ok == 0, "register jdk.internal.misc.Unsafe natives");
1232 } JVM_END