1 /*
2 * Copyright (c) 2000, 2017, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "precompiled.hpp"
26 #include "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 "utilities/copy.hpp"
43 #include "utilities/dtrace.hpp"
44 #include "utilities/macros.hpp"
45 #if INCLUDE_ALL_GCS
46 #include "gc/g1/g1SATBCardTableModRefBS.hpp"
47 #endif // INCLUDE_ALL_GCS
48 #if INCLUDE_TRACE
49 #include "trace/tracing.hpp"
50 #endif
51 /**
52 * Implementation of the jdk.internal.misc.Unsafe class
53 */
54
55
56 #define MAX_OBJECT_SIZE \
57 ( arrayOopDesc::header_size(T_DOUBLE) * HeapWordSize \
58 + ((julong)max_jint * sizeof(double)) )
59
60
61 #define UNSAFE_ENTRY(result_type, header) \
62 JVM_ENTRY(static result_type, header)
63
64 #define UNSAFE_LEAF(result_type, header) \
65 JVM_LEAF(static result_type, header)
66
67 #define UNSAFE_END JVM_END
68
69
70 static inline void* addr_from_java(jlong addr) {
71 // This assert fails in a variety of ways on 32-bit systems.
72 // It is impossible to predict whether native code that converts
73 // pointers to longs will sign-extend or zero-extend the addresses.
74 //assert(addr == (uintptr_t)addr, "must not be odd high bits");
75 return (void*)(uintptr_t)addr;
76 }
77
78 static inline jlong addr_to_java(void* p) {
79 assert(p == (void*)(uintptr_t)p, "must not be odd high bits");
80 return (uintptr_t)p;
81 }
82
83
84 // Note: The VM's obj_field and related accessors use byte-scaled
85 // ("unscaled") offsets, just as the unsafe methods do.
86
87 // However, the method Unsafe.fieldOffset explicitly declines to
88 // guarantee this. The field offset values manipulated by the Java user
89 // through the Unsafe API are opaque cookies that just happen to be byte
90 // offsets. We represent this state of affairs by passing the cookies
91 // through conversion functions when going between the VM and the Unsafe API.
92 // The conversion functions just happen to be no-ops at present.
93
94 static inline jlong field_offset_to_byte_offset(jlong field_offset) {
95 return field_offset;
96 }
97
98 static inline jlong field_offset_from_byte_offset(jlong byte_offset) {
99 return byte_offset;
100 }
101
102 static inline void* index_oop_from_field_offset_long(oop p, jlong field_offset) {
103 jlong byte_offset = field_offset_to_byte_offset(field_offset);
104
105 #ifdef ASSERT
106 if (p != NULL) {
107 assert(byte_offset >= 0 && byte_offset <= (jlong)MAX_OBJECT_SIZE, "sane offset");
108 if (byte_offset == (jint)byte_offset) {
109 void* ptr_plus_disp = (address)p + byte_offset;
110 assert((void*)p->obj_field_addr<oop>((jint)byte_offset) == ptr_plus_disp,
111 "raw [ptr+disp] must be consistent with oop::field_base");
112 }
113 jlong p_size = HeapWordSize * (jlong)(p->size());
114 assert(byte_offset < p_size, "Unsafe access: offset " INT64_FORMAT " > object's size " INT64_FORMAT, byte_offset, p_size);
115 }
116 #endif
117
118 if (sizeof(char*) == sizeof(jint)) { // (this constant folds!)
119 return (address)p + (jint) byte_offset;
120 } else {
121 return (address)p + byte_offset;
122 }
123 }
124
125 // Externally callable versions:
126 // (Use these in compiler intrinsics which emulate unsafe primitives.)
127 jlong Unsafe_field_offset_to_byte_offset(jlong field_offset) {
128 return field_offset;
129 }
130 jlong Unsafe_field_offset_from_byte_offset(jlong byte_offset) {
131 return byte_offset;
132 }
133
134
135 ///// Data read/writes on the Java heap and in native (off-heap) memory
136
137 /**
138 * Helper class for accessing memory.
139 *
140 * Normalizes values and wraps accesses in
141 * JavaThread::doing_unsafe_access() if needed.
142 */
143 class MemoryAccess : StackObj {
144 JavaThread* _thread;
145 jobject _obj;
146 jlong _offset;
147
148 // Resolves and returns the address of the memory access
149 void* addr() {
150 return index_oop_from_field_offset_long(JNIHandles::resolve(_obj), _offset);
151 }
152
153 template <typename T>
154 T normalize_for_write(T x) {
155 return x;
156 }
157
158 jboolean normalize_for_write(jboolean x) {
159 return x & 1;
160 }
161
162 template <typename T>
163 T normalize_for_read(T x) {
164 return x;
165 }
166
167 jboolean normalize_for_read(jboolean x) {
168 return x != 0;
169 }
170
171 /**
172 * Helper class to wrap memory accesses in JavaThread::doing_unsafe_access()
173 */
174 class GuardUnsafeAccess {
175 JavaThread* _thread;
176 bool _active;
177
178 public:
179 GuardUnsafeAccess(JavaThread* thread, jobject _obj) : _thread(thread) {
180 if (JNIHandles::resolve(_obj) == NULL) {
181 // native/off-heap access which may raise SIGBUS if accessing
182 // memory mapped file data in a region of the file which has
183 // been truncated and is now invalid
184 _thread->set_doing_unsafe_access(true);
185 _active = true;
186 } else {
187 _active = false;
188 }
189 }
190
191 ~GuardUnsafeAccess() {
192 if (_active) {
193 _thread->set_doing_unsafe_access(false);
194 }
195 }
196 };
197
198 public:
199 MemoryAccess(JavaThread* thread, jobject obj, jlong offset)
200 : _thread(thread), _obj(obj), _offset(offset) {
201 }
202
203 template <typename T>
204 T get() {
205 GuardUnsafeAccess guard(_thread, _obj);
206
207 T* p = (T*)addr();
208
209 T x = normalize_for_read(*p);
210
211 return x;
212 }
213
214 template <typename T>
215 void put(T x) {
216 GuardUnsafeAccess guard(_thread, _obj);
217
218 T* p = (T*)addr();
219
220 *p = normalize_for_write(x);
221 }
222
223
224 template <typename T>
225 T get_volatile() {
226 GuardUnsafeAccess guard(_thread, _obj);
227
228 T* p = (T*)addr();
229
230 if (support_IRIW_for_not_multiple_copy_atomic_cpu) {
231 OrderAccess::fence();
232 }
233
234 T x = OrderAccess::load_acquire((volatile T*)p);
235
236 return normalize_for_read(x);
237 }
238
239 template <typename T>
240 void put_volatile(T x) {
241 GuardUnsafeAccess guard(_thread, _obj);
242
243 T* p = (T*)addr();
244
245 OrderAccess::release_store_fence((volatile T*)p, normalize_for_write(x));
246 }
247
248
249 #ifndef SUPPORTS_NATIVE_CX8
250 jlong get_jlong_locked() {
251 GuardUnsafeAccess guard(_thread, _obj);
252
253 MutexLockerEx mu(UnsafeJlong_lock, Mutex::_no_safepoint_check_flag);
254
255 jlong* p = (jlong*)addr();
256
257 jlong x = Atomic::load(p);
258
259 return x;
260 }
261
262 void put_jlong_locked(jlong x) {
263 GuardUnsafeAccess guard(_thread, _obj);
264
265 MutexLockerEx mu(UnsafeJlong_lock, Mutex::_no_safepoint_check_flag);
266
267 jlong* p = (jlong*)addr();
268
269 Atomic::store(normalize_for_write(x), p);
270 }
271 #endif
272 };
273
274 // Get/PutObject must be special-cased, since it works with handles.
275
276 // We could be accessing the referent field in a reference
277 // object. If G1 is enabled then we need to register non-null
278 // referent with the SATB barrier.
279
280 #if INCLUDE_ALL_GCS
281 static bool is_java_lang_ref_Reference_access(oop o, jlong offset) {
282 if (offset == java_lang_ref_Reference::referent_offset && o != NULL) {
283 Klass* k = o->klass();
284 if (InstanceKlass::cast(k)->reference_type() != REF_NONE) {
285 assert(InstanceKlass::cast(k)->is_subclass_of(SystemDictionary::Reference_klass()), "sanity");
286 return true;
287 }
288 }
289 return false;
290 }
291 #endif
292
293 static void ensure_satb_referent_alive(oop o, jlong offset, oop v) {
294 #if INCLUDE_ALL_GCS
295 if (UseG1GC && v != NULL && is_java_lang_ref_Reference_access(o, offset)) {
296 G1SATBCardTableModRefBS::enqueue(v);
297 }
298 #endif
299 }
300
301 // These functions allow a null base pointer with an arbitrary address.
302 // But if the base pointer is non-null, the offset should make some sense.
303 // That is, it should be in the range [0, MAX_OBJECT_SIZE].
304 UNSAFE_ENTRY(jobject, Unsafe_GetObject(JNIEnv *env, jobject unsafe, jobject obj, jlong offset)) {
305 oop p = JNIHandles::resolve(obj);
306 oop v;
307
308 if (UseCompressedOops) {
309 narrowOop n = *(narrowOop*)index_oop_from_field_offset_long(p, offset);
310 v = oopDesc::decode_heap_oop(n);
311 } else {
312 v = *(oop*)index_oop_from_field_offset_long(p, offset);
313 }
314
315 ensure_satb_referent_alive(p, offset, v);
316
317 return JNIHandles::make_local(env, v);
318 } UNSAFE_END
319
320 UNSAFE_ENTRY(void, Unsafe_PutObject(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jobject x_h)) {
321 oop x = JNIHandles::resolve(x_h);
322 oop p = JNIHandles::resolve(obj);
323
324 if (UseCompressedOops) {
325 oop_store((narrowOop*)index_oop_from_field_offset_long(p, offset), x);
326 } else {
327 oop_store((oop*)index_oop_from_field_offset_long(p, offset), x);
328 }
329 } UNSAFE_END
330
331 UNSAFE_ENTRY(jobject, Unsafe_GetObjectVolatile(JNIEnv *env, jobject unsafe, jobject obj, jlong offset)) {
332 oop p = JNIHandles::resolve(obj);
333 void* addr = index_oop_from_field_offset_long(p, offset);
334
335 volatile oop v;
336
337 if (support_IRIW_for_not_multiple_copy_atomic_cpu) {
338 OrderAccess::fence();
339 }
340
341 if (UseCompressedOops) {
342 volatile narrowOop n = *(volatile narrowOop*) addr;
343 (void)const_cast<oop&>(v = oopDesc::decode_heap_oop(n));
344 } else {
345 (void)const_cast<oop&>(v = *(volatile oop*) addr);
346 }
347
348 ensure_satb_referent_alive(p, offset, v);
349
350 OrderAccess::acquire();
351 return JNIHandles::make_local(env, v);
352 } UNSAFE_END
353
354 UNSAFE_ENTRY(void, Unsafe_PutObjectVolatile(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jobject x_h)) {
355 oop x = JNIHandles::resolve(x_h);
356 oop p = JNIHandles::resolve(obj);
357 void* addr = index_oop_from_field_offset_long(p, offset);
358 OrderAccess::release();
359
360 if (UseCompressedOops) {
361 oop_store((narrowOop*)addr, x);
362 } else {
363 oop_store((oop*)addr, x);
364 }
365
366 OrderAccess::fence();
367 } UNSAFE_END
368
369 UNSAFE_ENTRY(jobject, Unsafe_GetUncompressedObject(JNIEnv *env, jobject unsafe, jlong addr)) {
370 oop v = *(oop*) (address) addr;
371
372 return JNIHandles::make_local(env, v);
373 } UNSAFE_END
374
375 #ifndef SUPPORTS_NATIVE_CX8
376
377 // VM_Version::supports_cx8() is a surrogate for 'supports atomic long memory ops'.
378 //
379 // On platforms which do not support atomic compare-and-swap of jlong (8 byte)
380 // values we have to use a lock-based scheme to enforce atomicity. This has to be
381 // applied to all Unsafe operations that set the value of a jlong field. Even so
382 // the compareAndSetLong operation will not be atomic with respect to direct stores
383 // to the field from Java code. It is important therefore that any Java code that
384 // utilizes these Unsafe jlong operations does not perform direct stores. To permit
385 // direct loads of the field from Java code we must also use Atomic::store within the
386 // locked regions. And for good measure, in case there are direct stores, we also
387 // employ Atomic::load within those regions. Note that the field in question must be
388 // volatile and so must have atomic load/store accesses applied at the Java level.
389 //
390 // The locking scheme could utilize a range of strategies for controlling the locking
391 // granularity: from a lock per-field through to a single global lock. The latter is
392 // the simplest and is used for the current implementation. Note that the Java object
393 // that contains the field, can not, in general, be used for locking. To do so can lead
394 // to deadlocks as we may introduce locking into what appears to the Java code to be a
395 // lock-free path.
396 //
397 // As all the locked-regions are very short and themselves non-blocking we can treat
398 // them as leaf routines and elide safepoint checks (ie we don't perform any thread
399 // state transitions even when blocking for the lock). Note that if we do choose to
400 // add safepoint checks and thread state transitions, we must ensure that we calculate
401 // the address of the field _after_ we have acquired the lock, else the object may have
402 // been moved by the GC
403
404 UNSAFE_ENTRY(jlong, Unsafe_GetLongVolatile(JNIEnv *env, jobject unsafe, jobject obj, jlong offset)) {
405 if (VM_Version::supports_cx8()) {
406 return MemoryAccess(thread, obj, offset).get_volatile<jlong>();
407 } else {
408 return MemoryAccess(thread, obj, offset).get_jlong_locked();
409 }
410 } UNSAFE_END
411
412 UNSAFE_ENTRY(void, Unsafe_PutLongVolatile(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jlong x)) {
413 if (VM_Version::supports_cx8()) {
414 MemoryAccess(thread, obj, offset).put_volatile<jlong>(x);
415 } else {
416 MemoryAccess(thread, obj, offset).put_jlong_locked(x);
417 }
418 } UNSAFE_END
419
420 #endif // not SUPPORTS_NATIVE_CX8
421
422 UNSAFE_LEAF(jboolean, Unsafe_isBigEndian0(JNIEnv *env, jobject unsafe)) {
423 #ifdef VM_LITTLE_ENDIAN
424 return false;
425 #else
426 return true;
427 #endif
428 } UNSAFE_END
429
430 UNSAFE_LEAF(jint, Unsafe_unalignedAccess0(JNIEnv *env, jobject unsafe)) {
431 return UseUnalignedAccesses;
432 } UNSAFE_END
433
434 #define DEFINE_GETSETOOP(java_type, Type) \
435 \
436 UNSAFE_ENTRY(java_type, Unsafe_Get##Type(JNIEnv *env, jobject unsafe, jobject obj, jlong offset)) { \
437 return MemoryAccess(thread, obj, offset).get<java_type>(); \
438 } UNSAFE_END \
439 \
440 UNSAFE_ENTRY(void, Unsafe_Put##Type(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, java_type x)) { \
441 MemoryAccess(thread, obj, offset).put<java_type>(x); \
442 } UNSAFE_END \
443 \
444 // END DEFINE_GETSETOOP.
445
446 DEFINE_GETSETOOP(jboolean, Boolean)
447 DEFINE_GETSETOOP(jbyte, Byte)
448 DEFINE_GETSETOOP(jshort, Short);
449 DEFINE_GETSETOOP(jchar, Char);
450 DEFINE_GETSETOOP(jint, Int);
451 DEFINE_GETSETOOP(jlong, Long);
452 DEFINE_GETSETOOP(jfloat, Float);
453 DEFINE_GETSETOOP(jdouble, Double);
454
455 #undef DEFINE_GETSETOOP
456
457 #define DEFINE_GETSETOOP_VOLATILE(java_type, Type) \
458 \
459 UNSAFE_ENTRY(java_type, Unsafe_Get##Type##Volatile(JNIEnv *env, jobject unsafe, jobject obj, jlong offset)) { \
460 return MemoryAccess(thread, obj, offset).get_volatile<java_type>(); \
461 } UNSAFE_END \
462 \
463 UNSAFE_ENTRY(void, Unsafe_Put##Type##Volatile(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, java_type x)) { \
464 MemoryAccess(thread, obj, offset).put_volatile<java_type>(x); \
465 } UNSAFE_END \
466 \
467 // END DEFINE_GETSETOOP_VOLATILE.
468
469 DEFINE_GETSETOOP_VOLATILE(jboolean, Boolean)
470 DEFINE_GETSETOOP_VOLATILE(jbyte, Byte)
471 DEFINE_GETSETOOP_VOLATILE(jshort, Short);
472 DEFINE_GETSETOOP_VOLATILE(jchar, Char);
473 DEFINE_GETSETOOP_VOLATILE(jint, Int);
474 DEFINE_GETSETOOP_VOLATILE(jfloat, Float);
475 DEFINE_GETSETOOP_VOLATILE(jdouble, Double);
476
477 #ifdef SUPPORTS_NATIVE_CX8
478 DEFINE_GETSETOOP_VOLATILE(jlong, Long);
479 #endif
480
481 #undef DEFINE_GETSETOOP_VOLATILE
482
483 UNSAFE_LEAF(void, Unsafe_LoadFence(JNIEnv *env, jobject unsafe)) {
484 OrderAccess::acquire();
485 } UNSAFE_END
486
487 UNSAFE_LEAF(void, Unsafe_StoreFence(JNIEnv *env, jobject unsafe)) {
488 OrderAccess::release();
489 } UNSAFE_END
490
491 UNSAFE_LEAF(void, Unsafe_FullFence(JNIEnv *env, jobject unsafe)) {
492 OrderAccess::fence();
493 } UNSAFE_END
494
495 ////// Allocation requests
496
497 UNSAFE_ENTRY(jobject, Unsafe_AllocateInstance(JNIEnv *env, jobject unsafe, jclass cls)) {
498 ThreadToNativeFromVM ttnfv(thread);
499 return env->AllocObject(cls);
500 } UNSAFE_END
501
502 UNSAFE_ENTRY(jlong, Unsafe_AllocateMemory0(JNIEnv *env, jobject unsafe, jlong size)) {
503 size_t sz = (size_t)size;
504
505 sz = round_to(sz, HeapWordSize);
506 void* x = os::malloc(sz, mtInternal);
507
508 return addr_to_java(x);
509 } UNSAFE_END
510
511 UNSAFE_ENTRY(jlong, Unsafe_ReallocateMemory0(JNIEnv *env, jobject unsafe, jlong addr, jlong size)) {
512 void* p = addr_from_java(addr);
513 size_t sz = (size_t)size;
514 sz = round_to(sz, HeapWordSize);
515
516 void* x = os::realloc(p, sz, mtInternal);
517
518 return addr_to_java(x);
519 } UNSAFE_END
520
521 UNSAFE_ENTRY(void, Unsafe_FreeMemory0(JNIEnv *env, jobject unsafe, jlong addr)) {
522 void* p = addr_from_java(addr);
523
524 os::free(p);
525 } UNSAFE_END
526
527 UNSAFE_ENTRY(void, Unsafe_SetMemory0(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jlong size, jbyte value)) {
528 size_t sz = (size_t)size;
529
530 oop base = JNIHandles::resolve(obj);
531 void* p = index_oop_from_field_offset_long(base, offset);
532
533 Copy::fill_to_memory_atomic(p, sz, value);
534 } UNSAFE_END
535
536 UNSAFE_ENTRY(void, Unsafe_CopyMemory0(JNIEnv *env, jobject unsafe, jobject srcObj, jlong srcOffset, jobject dstObj, jlong dstOffset, jlong size)) {
537 size_t sz = (size_t)size;
538
539 oop srcp = JNIHandles::resolve(srcObj);
540 oop dstp = JNIHandles::resolve(dstObj);
541
542 void* src = index_oop_from_field_offset_long(srcp, srcOffset);
543 void* dst = index_oop_from_field_offset_long(dstp, dstOffset);
544
545 Copy::conjoint_memory_atomic(src, dst, sz);
546 } UNSAFE_END
547
548 // This function is a leaf since if the source and destination are both in native memory
549 // the copy may potentially be very large, and we don't want to disable GC if we can avoid it.
550 // If either source or destination (or both) are on the heap, the function will enter VM using
551 // JVM_ENTRY_FROM_LEAF
552 UNSAFE_LEAF(void, Unsafe_CopySwapMemory0(JNIEnv *env, jobject unsafe, jobject srcObj, jlong srcOffset, jobject dstObj, jlong dstOffset, jlong size, jlong elemSize)) {
553 size_t sz = (size_t)size;
554 size_t esz = (size_t)elemSize;
555
556 if (srcObj == NULL && dstObj == NULL) {
557 // Both src & dst are in native memory
558 address src = (address)srcOffset;
559 address dst = (address)dstOffset;
560
561 Copy::conjoint_swap(src, dst, sz, esz);
562 } else {
563 // At least one of src/dst are on heap, transition to VM to access raw pointers
564
565 JVM_ENTRY_FROM_LEAF(env, void, Unsafe_CopySwapMemory0) {
566 oop srcp = JNIHandles::resolve(srcObj);
567 oop dstp = JNIHandles::resolve(dstObj);
568
569 address src = (address)index_oop_from_field_offset_long(srcp, srcOffset);
570 address dst = (address)index_oop_from_field_offset_long(dstp, dstOffset);
571
572 Copy::conjoint_swap(src, dst, sz, esz);
573 } JVM_END
574 }
575 } UNSAFE_END
576
577 ////// Random queries
578
579 UNSAFE_LEAF(jint, Unsafe_AddressSize0(JNIEnv *env, jobject unsafe)) {
580 return sizeof(void*);
581 } UNSAFE_END
582
583 UNSAFE_LEAF(jint, Unsafe_PageSize()) {
584 return os::vm_page_size();
585 } UNSAFE_END
586
587 static jint find_field_offset(jobject field, int must_be_static, TRAPS) {
588 assert(field != NULL, "field must not be NULL");
589
590 oop reflected = JNIHandles::resolve_non_null(field);
591 oop mirror = java_lang_reflect_Field::clazz(reflected);
592 Klass* k = java_lang_Class::as_Klass(mirror);
593 int slot = java_lang_reflect_Field::slot(reflected);
594 int modifiers = java_lang_reflect_Field::modifiers(reflected);
595
596 if (must_be_static >= 0) {
597 int really_is_static = ((modifiers & JVM_ACC_STATIC) != 0);
598 if (must_be_static != really_is_static) {
599 THROW_0(vmSymbols::java_lang_IllegalArgumentException());
600 }
601 }
602
603 int offset = InstanceKlass::cast(k)->field_offset(slot);
604 return field_offset_from_byte_offset(offset);
605 }
606
607 UNSAFE_ENTRY(jlong, Unsafe_ObjectFieldOffset0(JNIEnv *env, jobject unsafe, jobject field)) {
608 return find_field_offset(field, 0, THREAD);
609 } UNSAFE_END
610
611 UNSAFE_ENTRY(jlong, Unsafe_StaticFieldOffset0(JNIEnv *env, jobject unsafe, jobject field)) {
612 return find_field_offset(field, 1, THREAD);
613 } UNSAFE_END
614
615 UNSAFE_ENTRY(jobject, Unsafe_StaticFieldBase0(JNIEnv *env, jobject unsafe, jobject field)) {
616 assert(field != NULL, "field must not be NULL");
617
618 // Note: In this VM implementation, a field address is always a short
619 // offset from the base of a a klass metaobject. Thus, the full dynamic
620 // range of the return type is never used. However, some implementations
621 // might put the static field inside an array shared by many classes,
622 // or even at a fixed address, in which case the address could be quite
623 // large. In that last case, this function would return NULL, since
624 // the address would operate alone, without any base pointer.
625
626 oop reflected = JNIHandles::resolve_non_null(field);
627 oop mirror = java_lang_reflect_Field::clazz(reflected);
628 int modifiers = java_lang_reflect_Field::modifiers(reflected);
629
630 if ((modifiers & JVM_ACC_STATIC) == 0) {
631 THROW_0(vmSymbols::java_lang_IllegalArgumentException());
632 }
633
634 return JNIHandles::make_local(env, mirror);
635 } UNSAFE_END
636
637 UNSAFE_ENTRY(void, Unsafe_EnsureClassInitialized0(JNIEnv *env, jobject unsafe, jobject clazz)) {
638 assert(clazz != NULL, "clazz must not be NULL");
639
640 oop mirror = JNIHandles::resolve_non_null(clazz);
641
642 Klass* klass = java_lang_Class::as_Klass(mirror);
643 if (klass != NULL && klass->should_be_initialized()) {
644 InstanceKlass* k = InstanceKlass::cast(klass);
645 k->initialize(CHECK);
646 }
647 }
648 UNSAFE_END
649
650 UNSAFE_ENTRY(jboolean, Unsafe_ShouldBeInitialized0(JNIEnv *env, jobject unsafe, jobject clazz)) {
651 assert(clazz != NULL, "clazz must not be NULL");
652
653 oop mirror = JNIHandles::resolve_non_null(clazz);
654 Klass* klass = java_lang_Class::as_Klass(mirror);
655
656 if (klass != NULL && klass->should_be_initialized()) {
657 return true;
658 }
659
660 return false;
661 }
662 UNSAFE_END
663
664 static void getBaseAndScale(int& base, int& scale, jclass clazz, TRAPS) {
665 assert(clazz != NULL, "clazz must not be NULL");
666
667 oop mirror = JNIHandles::resolve_non_null(clazz);
668 Klass* k = java_lang_Class::as_Klass(mirror);
669
670 if (k == NULL || !k->is_array_klass()) {
671 THROW(vmSymbols::java_lang_InvalidClassException());
672 } else if (k->is_objArray_klass()) {
673 base = arrayOopDesc::base_offset_in_bytes(T_OBJECT);
674 scale = heapOopSize;
675 } else if (k->is_typeArray_klass()) {
676 TypeArrayKlass* tak = TypeArrayKlass::cast(k);
677 base = tak->array_header_in_bytes();
678 assert(base == arrayOopDesc::base_offset_in_bytes(tak->element_type()), "array_header_size semantics ok");
679 scale = (1 << tak->log2_element_size());
680 } else {
681 ShouldNotReachHere();
682 }
683 }
684
685 UNSAFE_ENTRY(jint, Unsafe_ArrayBaseOffset0(JNIEnv *env, jobject unsafe, jclass clazz)) {
686 int base = 0, scale = 0;
687 getBaseAndScale(base, scale, clazz, CHECK_0);
688
689 return field_offset_from_byte_offset(base);
690 } UNSAFE_END
691
692
693 UNSAFE_ENTRY(jint, Unsafe_ArrayIndexScale0(JNIEnv *env, jobject unsafe, jclass clazz)) {
694 int base = 0, scale = 0;
695 getBaseAndScale(base, scale, clazz, CHECK_0);
696
697 // This VM packs both fields and array elements down to the byte.
698 // But watch out: If this changes, so that array references for
699 // a given primitive type (say, T_BOOLEAN) use different memory units
700 // than fields, this method MUST return zero for such arrays.
701 // For example, the VM used to store sub-word sized fields in full
702 // words in the object layout, so that accessors like getByte(Object,int)
703 // did not really do what one might expect for arrays. Therefore,
704 // this function used to report a zero scale factor, so that the user
705 // would know not to attempt to access sub-word array elements.
706 // // Code for unpacked fields:
707 // if (scale < wordSize) return 0;
708
709 // The following allows for a pretty general fieldOffset cookie scheme,
710 // but requires it to be linear in byte offset.
711 return field_offset_from_byte_offset(scale) - field_offset_from_byte_offset(0);
712 } UNSAFE_END
713
714
715 static inline void throw_new(JNIEnv *env, const char *ename) {
716 char buf[100];
717
718 jio_snprintf(buf, 100, "%s%s", "java/lang/", ename);
719
720 jclass cls = env->FindClass(buf);
721 if (env->ExceptionCheck()) {
722 env->ExceptionClear();
723 tty->print_cr("Unsafe: cannot throw %s because FindClass has failed", buf);
724 return;
725 }
726
727 env->ThrowNew(cls, NULL);
728 }
729
730 static jclass Unsafe_DefineClass_impl(JNIEnv *env, jstring name, jbyteArray data, int offset, int length, jobject loader, jobject pd) {
731 // Code lifted from JDK 1.3 ClassLoader.c
732
733 jbyte *body;
734 char *utfName = NULL;
735 jclass result = 0;
736 char buf[128];
737
738 assert(data != NULL, "Class bytes must not be NULL");
739 assert(length >= 0, "length must not be negative: %d", length);
740
741 if (UsePerfData) {
742 ClassLoader::unsafe_defineClassCallCounter()->inc();
743 }
744
745 body = NEW_C_HEAP_ARRAY(jbyte, length, mtInternal);
746 if (body == NULL) {
747 throw_new(env, "OutOfMemoryError");
748 return 0;
749 }
750
751 env->GetByteArrayRegion(data, offset, length, body);
752 if (env->ExceptionOccurred()) {
753 goto free_body;
754 }
755
756 if (name != NULL) {
757 uint len = env->GetStringUTFLength(name);
758 int unicode_len = env->GetStringLength(name);
759
760 if (len >= sizeof(buf)) {
761 utfName = NEW_C_HEAP_ARRAY(char, len + 1, mtInternal);
762 if (utfName == NULL) {
763 throw_new(env, "OutOfMemoryError");
764 goto free_body;
765 }
766 } else {
767 utfName = buf;
768 }
769
770 env->GetStringUTFRegion(name, 0, unicode_len, utfName);
771
772 for (uint i = 0; i < len; i++) {
773 if (utfName[i] == '.') utfName[i] = '/';
774 }
775 }
776
777 result = JVM_DefineClass(env, utfName, loader, body, length, pd);
778
779 if (utfName && utfName != buf) {
780 FREE_C_HEAP_ARRAY(char, utfName);
781 }
782
783 free_body:
784 FREE_C_HEAP_ARRAY(jbyte, body);
785 return result;
786 }
787
788
789 UNSAFE_ENTRY(jclass, Unsafe_DefineClass0(JNIEnv *env, jobject unsafe, jstring name, jbyteArray data, int offset, int length, jobject loader, jobject pd)) {
790 ThreadToNativeFromVM ttnfv(thread);
791
792 return Unsafe_DefineClass_impl(env, name, data, offset, length, loader, pd);
793 } UNSAFE_END
794
795
796 // define a class but do not make it known to the class loader or system dictionary
797 // - host_class: supplies context for linkage, access control, protection domain, and class loader
798 // if host_class is itself anonymous then it is replaced with its host class.
799 // - data: bytes of a class file, a raw memory address (length gives the number of bytes)
800 // - cp_patches: where non-null entries exist, they replace corresponding CP entries in data
801
802 // When you load an anonymous class U, it works as if you changed its name just before loading,
803 // to a name that you will never use again. Since the name is lost, no other class can directly
804 // link to any member of U. Just after U is loaded, the only way to use it is reflectively,
805 // through java.lang.Class methods like Class.newInstance.
806
807 // The package of an anonymous class must either match its host's class's package or be in the
808 // unnamed package. If it is in the unnamed package then it will be put in its host class's
809 // package.
810 //
811
812 // Access checks for linkage sites within U continue to follow the same rules as for named classes.
813 // An anonymous class also has special privileges to access any member of its host class.
814 // This is the main reason why this loading operation is unsafe. The purpose of this is to
815 // allow language implementations to simulate "open classes"; a host class in effect gets
816 // new code when an anonymous class is loaded alongside it. A less convenient but more
817 // standard way to do this is with reflection, which can also be set to ignore access
818 // restrictions.
819
820 // Access into an anonymous class is possible only through reflection. Therefore, there
821 // are no special access rules for calling into an anonymous class. The relaxed access
822 // rule for the host class is applied in the opposite direction: A host class reflectively
823 // access one of its anonymous classes.
824
825 // If you load the same bytecodes twice, you get two different classes. You can reload
826 // the same bytecodes with or without varying CP patches.
827
828 // By using the CP patching array, you can have a new anonymous class U2 refer to an older one U1.
829 // The bytecodes for U2 should refer to U1 by a symbolic name (doesn't matter what the name is).
830 // The CONSTANT_Class entry for that name can be patched to refer directly to U1.
831
832 // This allows, for example, U2 to use U1 as a superclass or super-interface, or as
833 // an outer class (so that U2 is an anonymous inner class of anonymous U1).
834 // It is not possible for a named class, or an older anonymous class, to refer by
835 // name (via its CP) to a newer anonymous class.
836
837 // CP patching may also be used to modify (i.e., hack) the names of methods, classes,
838 // or type descriptors used in the loaded anonymous class.
839
840 // Finally, CP patching may be used to introduce "live" objects into the constant pool,
841 // instead of "dead" strings. A compiled statement like println((Object)"hello") can
842 // be changed to println(greeting), where greeting is an arbitrary object created before
843 // the anonymous class is loaded. This is useful in dynamic languages, in which
844 // various kinds of metaobjects must be introduced as constants into bytecode.
845 // Note the cast (Object), which tells the verifier to expect an arbitrary object,
846 // not just a literal string. For such ldc instructions, the verifier uses the
847 // type Object instead of String, if the loaded constant is not in fact a String.
848
849 static InstanceKlass*
850 Unsafe_DefineAnonymousClass_impl(JNIEnv *env,
851 jclass host_class, jbyteArray data, jobjectArray cp_patches_jh,
852 u1** temp_alloc,
853 TRAPS) {
854 assert(host_class != NULL, "host_class must not be NULL");
855 assert(data != NULL, "data must not be NULL");
856
857 if (UsePerfData) {
858 ClassLoader::unsafe_defineClassCallCounter()->inc();
859 }
860
861 jint length = typeArrayOop(JNIHandles::resolve_non_null(data))->length();
862 assert(length >= 0, "class_bytes_length must not be negative: %d", length);
863
864 int class_bytes_length = (int) length;
865
866 u1* class_bytes = NEW_C_HEAP_ARRAY(u1, length, mtInternal);
867 if (class_bytes == NULL) {
868 THROW_0(vmSymbols::java_lang_OutOfMemoryError());
869 }
870
871 // caller responsible to free it:
872 *temp_alloc = class_bytes;
873
874 jbyte* array_base = typeArrayOop(JNIHandles::resolve_non_null(data))->byte_at_addr(0);
875 Copy::conjoint_jbytes(array_base, class_bytes, length);
876
877 objArrayHandle cp_patches_h;
878 if (cp_patches_jh != NULL) {
879 oop p = JNIHandles::resolve_non_null(cp_patches_jh);
880 assert(p->is_objArray(), "cp_patches must be an object[]");
881 cp_patches_h = objArrayHandle(THREAD, (objArrayOop)p);
882 }
883
884 const Klass* host_klass = java_lang_Class::as_Klass(JNIHandles::resolve_non_null(host_class));
885
886 // Make sure it's the real host class, not another anonymous class.
887 while (host_klass != NULL && host_klass->is_instance_klass() &&
888 InstanceKlass::cast(host_klass)->is_anonymous()) {
889 host_klass = InstanceKlass::cast(host_klass)->host_klass();
890 }
891
892 // Primitive types have NULL Klass* fields in their java.lang.Class instances.
893 if (host_klass == NULL) {
894 THROW_MSG_0(vmSymbols::java_lang_IllegalArgumentException(), "Host class is null");
895 }
896
897 assert(host_klass->is_instance_klass(), "Host class must be an instance class");
898
899 const char* host_source = host_klass->external_name();
900 Handle host_loader(THREAD, host_klass->class_loader());
901 Handle host_domain(THREAD, host_klass->protection_domain());
902
903 GrowableArray<Handle>* cp_patches = NULL;
904
905 if (cp_patches_h.not_null()) {
906 int alen = cp_patches_h->length();
907
908 for (int i = alen-1; i >= 0; i--) {
909 oop p = cp_patches_h->obj_at(i);
910 if (p != NULL) {
911 Handle patch(THREAD, p);
912
913 if (cp_patches == NULL) {
914 cp_patches = new GrowableArray<Handle>(i+1, i+1, Handle());
915 }
916
917 cp_patches->at_put(i, patch);
918 }
919 }
920 }
921
922 ClassFileStream st(class_bytes, class_bytes_length, host_source, ClassFileStream::verify);
923
924 Symbol* no_class_name = NULL;
925 Klass* anonk = SystemDictionary::parse_stream(no_class_name,
926 host_loader,
927 host_domain,
928 &st,
929 InstanceKlass::cast(host_klass),
930 cp_patches,
931 CHECK_NULL);
932 if (anonk == NULL) {
933 return NULL;
934 }
935
936 return InstanceKlass::cast(anonk);
937 }
938
939 UNSAFE_ENTRY(jclass, Unsafe_DefineAnonymousClass0(JNIEnv *env, jobject unsafe, jclass host_class, jbyteArray data, jobjectArray cp_patches_jh)) {
940 ResourceMark rm(THREAD);
941
942 jobject res_jh = NULL;
943 u1* temp_alloc = NULL;
944
945 InstanceKlass* anon_klass = Unsafe_DefineAnonymousClass_impl(env, host_class, data, cp_patches_jh, &temp_alloc, THREAD);
946 if (anon_klass != NULL) {
947 res_jh = JNIHandles::make_local(env, anon_klass->java_mirror());
948 }
949
950 // try/finally clause:
951 if (temp_alloc != NULL) {
952 FREE_C_HEAP_ARRAY(u1, temp_alloc);
953 }
954
955 // The anonymous class loader data has been artificially been kept alive to
956 // this point. The mirror and any instances of this class have to keep
957 // it alive afterwards.
958 if (anon_klass != NULL) {
959 anon_klass->class_loader_data()->dec_keep_alive();
960 }
961
962 // let caller initialize it as needed...
963
964 return (jclass) res_jh;
965 } UNSAFE_END
966
967
968
969 UNSAFE_ENTRY(void, Unsafe_ThrowException(JNIEnv *env, jobject unsafe, jthrowable thr)) {
970 ThreadToNativeFromVM ttnfv(thread);
971 env->Throw(thr);
972 } UNSAFE_END
973
974 // JSR166 ------------------------------------------------------------------
975
976 UNSAFE_ENTRY(jobject, Unsafe_CompareAndExchangeObject(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jobject e_h, jobject x_h)) {
977 oop x = JNIHandles::resolve(x_h);
978 oop e = JNIHandles::resolve(e_h);
979 oop p = JNIHandles::resolve(obj);
980 HeapWord* addr = (HeapWord *)index_oop_from_field_offset_long(p, offset);
981 oop res = oopDesc::atomic_compare_exchange_oop(x, addr, e, true);
982 if (res == e) {
983 update_barrier_set((void*)addr, x);
984 }
985 return JNIHandles::make_local(env, res);
986 } UNSAFE_END
987
988 UNSAFE_ENTRY(jint, Unsafe_CompareAndExchangeInt(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jint e, jint x)) {
989 oop p = JNIHandles::resolve(obj);
990 jint* addr = (jint *) index_oop_from_field_offset_long(p, offset);
991
992 return (jint)(Atomic::cmpxchg(x, addr, e));
993 } UNSAFE_END
994
995 UNSAFE_ENTRY(jlong, Unsafe_CompareAndExchangeLong(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jlong e, jlong x)) {
996 Handle p(THREAD, JNIHandles::resolve(obj));
997 jlong* addr = (jlong*)index_oop_from_field_offset_long(p(), offset);
998
999 #ifdef SUPPORTS_NATIVE_CX8
1000 return (jlong)(Atomic::cmpxchg(x, addr, e));
1001 #else
1002 if (VM_Version::supports_cx8()) {
1003 return (jlong)(Atomic::cmpxchg(x, addr, e));
1004 } else {
1005 MutexLockerEx mu(UnsafeJlong_lock, Mutex::_no_safepoint_check_flag);
1006
1007 jlong val = Atomic::load(addr);
1008 if (val == e) {
1009 Atomic::store(x, addr);
1010 }
1011 return val;
1012 }
1013 #endif
1014 } UNSAFE_END
1015
1016 UNSAFE_ENTRY(jboolean, Unsafe_CompareAndSetObject(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jobject e_h, jobject x_h)) {
1017 oop x = JNIHandles::resolve(x_h);
1018 oop e = JNIHandles::resolve(e_h);
1019 oop p = JNIHandles::resolve(obj);
1020 HeapWord* addr = (HeapWord *)index_oop_from_field_offset_long(p, offset);
1021 oop res = oopDesc::atomic_compare_exchange_oop(x, addr, e, true);
1022 if (res != e) {
1023 return false;
1024 }
1025
1026 update_barrier_set((void*)addr, x);
1027
1028 return true;
1029 } UNSAFE_END
1030
1031 UNSAFE_ENTRY(jboolean, Unsafe_CompareAndSetInt(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jint e, jint x)) {
1032 oop p = JNIHandles::resolve(obj);
1033 jint* addr = (jint *)index_oop_from_field_offset_long(p, offset);
1034
1035 return (jint)(Atomic::cmpxchg(x, addr, e)) == e;
1036 } UNSAFE_END
1037
1038 UNSAFE_ENTRY(jboolean, Unsafe_CompareAndSetLong(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jlong e, jlong x)) {
1039 Handle p(THREAD, JNIHandles::resolve(obj));
1040 jlong* addr = (jlong*)index_oop_from_field_offset_long(p(), offset);
1041
1042 #ifdef SUPPORTS_NATIVE_CX8
1043 return (jlong)(Atomic::cmpxchg(x, addr, e)) == e;
1044 #else
1045 if (VM_Version::supports_cx8()) {
1046 return (jlong)(Atomic::cmpxchg(x, addr, e)) == e;
1047 } else {
1048 MutexLockerEx mu(UnsafeJlong_lock, Mutex::_no_safepoint_check_flag);
1049
1050 jlong val = Atomic::load(addr);
1051 if (val != e) {
1052 return false;
1053 }
1054
1055 Atomic::store(x, addr);
1056 return true;
1057 }
1058 #endif
1059 } UNSAFE_END
1060
1061 #if INCLUDE_TRACE
1062 static void post_thread_park_event(EventThreadPark* event, const oop obj, jlong timeout) {
1063 assert(event != NULL, "invariant");
1064 if (event->should_commit()) {
1065 event->set_parkedClass((obj != NULL) ? obj->klass() : NULL);
1066 event->set_timeout(timeout);
1067 event->set_address((obj != NULL) ? (TYPE_ADDRESS) cast_from_oop<uintptr_t>(obj) : 0);
1068 event->commit();
1069 }
1070 }
1071 #endif
1072
1073 UNSAFE_ENTRY(void, Unsafe_Park(JNIEnv *env, jobject unsafe, jboolean isAbsolute, jlong time)) {
1074 HOTSPOT_THREAD_PARK_BEGIN((uintptr_t) thread->parker(), (int) isAbsolute, time);
1075 TRACE_ONLY(EventThreadPark event;)
1076 JavaThreadParkedState jtps(thread, time != 0);
1077 thread->parker()->park(isAbsolute != 0, time);
1078 HOTSPOT_THREAD_PARK_END((uintptr_t) thread->parker());
1079 TRACE_ONLY(post_thread_park_event(&event, thread->current_park_blocker(), time);)
1080
1081
1082 } UNSAFE_END
1083
1084 UNSAFE_ENTRY(void, Unsafe_Unpark(JNIEnv *env, jobject unsafe, jobject jthread)) {
1085 Parker* p = NULL;
1086
1087 if (jthread != NULL) {
1088 oop java_thread = JNIHandles::resolve_non_null(jthread);
1089 if (java_thread != NULL) {
1090 jlong lp = java_lang_Thread::park_event(java_thread);
1091 if (lp != 0) {
1092 // This cast is OK even though the jlong might have been read
1093 // non-atomically on 32bit systems, since there, one word will
1094 // always be zero anyway and the value set is always the same
1095 p = (Parker*)addr_from_java(lp);
1096 } else {
1097 // Grab lock if apparently null or using older version of library
1098 MutexLocker mu(Threads_lock);
1099 java_thread = JNIHandles::resolve_non_null(jthread);
1100
1101 if (java_thread != NULL) {
1102 JavaThread* thr = java_lang_Thread::thread(java_thread);
1103 if (thr != NULL) {
1104 p = thr->parker();
1105 if (p != NULL) { // Bind to Java thread for next time.
1106 java_lang_Thread::set_park_event(java_thread, addr_to_java(p));
1107 }
1108 }
1109 }
1110 }
1111 }
1112 }
1113
1114 if (p != NULL) {
1115 HOTSPOT_THREAD_UNPARK((uintptr_t) p);
1116 p->unpark();
1117 }
1118 } UNSAFE_END
1119
1120 UNSAFE_ENTRY(jint, Unsafe_GetLoadAverage0(JNIEnv *env, jobject unsafe, jdoubleArray loadavg, jint nelem)) {
1121 const int max_nelem = 3;
1122 double la[max_nelem];
1123 jint ret;
1124
1125 typeArrayOop a = typeArrayOop(JNIHandles::resolve_non_null(loadavg));
1126 assert(a->is_typeArray(), "must be type array");
1127
1128 ret = os::loadavg(la, nelem);
1129 if (ret == -1) {
1130 return -1;
1131 }
1132
1133 // if successful, ret is the number of samples actually retrieved.
1134 assert(ret >= 0 && ret <= max_nelem, "Unexpected loadavg return value");
1135 switch(ret) {
1136 case 3: a->double_at_put(2, (jdouble)la[2]); // fall through
1137 case 2: a->double_at_put(1, (jdouble)la[1]); // fall through
1138 case 1: a->double_at_put(0, (jdouble)la[0]); break;
1139 }
1140
1141 return ret;
1142 } UNSAFE_END
1143
1144
1145 /// JVM_RegisterUnsafeMethods
1146
1147 #define ADR "J"
1148
1149 #define LANG "Ljava/lang/"
1150
1151 #define OBJ LANG "Object;"
1152 #define CLS LANG "Class;"
1153 #define FLD LANG "reflect/Field;"
1154 #define THR LANG "Throwable;"
1155
1156 #define DC_Args LANG "String;[BII" LANG "ClassLoader;" "Ljava/security/ProtectionDomain;"
1157 #define DAC_Args CLS "[B[" OBJ
1158
1159 #define CC (char*) /*cast a literal from (const char*)*/
1160 #define FN_PTR(f) CAST_FROM_FN_PTR(void*, &f)
1161
1162 #define DECLARE_GETPUTOOP(Type, Desc) \
1163 {CC "get" #Type, CC "(" OBJ "J)" #Desc, FN_PTR(Unsafe_Get##Type)}, \
1164 {CC "put" #Type, CC "(" OBJ "J" #Desc ")V", FN_PTR(Unsafe_Put##Type)}, \
1165 {CC "get" #Type "Volatile", CC "(" OBJ "J)" #Desc, FN_PTR(Unsafe_Get##Type##Volatile)}, \
1166 {CC "put" #Type "Volatile", CC "(" OBJ "J" #Desc ")V", FN_PTR(Unsafe_Put##Type##Volatile)}
1167
1168
1169 static JNINativeMethod jdk_internal_misc_Unsafe_methods[] = {
1170 {CC "getObject", CC "(" OBJ "J)" OBJ "", FN_PTR(Unsafe_GetObject)},
1171 {CC "putObject", CC "(" OBJ "J" OBJ ")V", FN_PTR(Unsafe_PutObject)},
1172 {CC "getObjectVolatile",CC "(" OBJ "J)" OBJ "", FN_PTR(Unsafe_GetObjectVolatile)},
1173 {CC "putObjectVolatile",CC "(" OBJ "J" OBJ ")V", FN_PTR(Unsafe_PutObjectVolatile)},
1174
1175 {CC "getUncompressedObject", CC "(" ADR ")" OBJ, FN_PTR(Unsafe_GetUncompressedObject)},
1176
1177 DECLARE_GETPUTOOP(Boolean, Z),
1178 DECLARE_GETPUTOOP(Byte, B),
1179 DECLARE_GETPUTOOP(Short, S),
1180 DECLARE_GETPUTOOP(Char, C),
1181 DECLARE_GETPUTOOP(Int, I),
1182 DECLARE_GETPUTOOP(Long, J),
1183 DECLARE_GETPUTOOP(Float, F),
1184 DECLARE_GETPUTOOP(Double, D),
1185
1186 {CC "allocateMemory0", CC "(J)" ADR, FN_PTR(Unsafe_AllocateMemory0)},
1187 {CC "reallocateMemory0", CC "(" ADR "J)" ADR, FN_PTR(Unsafe_ReallocateMemory0)},
1188 {CC "freeMemory0", CC "(" ADR ")V", FN_PTR(Unsafe_FreeMemory0)},
1189
1190 {CC "objectFieldOffset0", CC "(" FLD ")J", FN_PTR(Unsafe_ObjectFieldOffset0)},
1191 {CC "staticFieldOffset0", CC "(" FLD ")J", FN_PTR(Unsafe_StaticFieldOffset0)},
1192 {CC "staticFieldBase0", CC "(" FLD ")" OBJ, FN_PTR(Unsafe_StaticFieldBase0)},
1193 {CC "ensureClassInitialized0", CC "(" CLS ")V", FN_PTR(Unsafe_EnsureClassInitialized0)},
1194 {CC "arrayBaseOffset0", CC "(" CLS ")I", FN_PTR(Unsafe_ArrayBaseOffset0)},
1195 {CC "arrayIndexScale0", CC "(" CLS ")I", FN_PTR(Unsafe_ArrayIndexScale0)},
1196 {CC "addressSize0", CC "()I", FN_PTR(Unsafe_AddressSize0)},
1197 {CC "pageSize", CC "()I", FN_PTR(Unsafe_PageSize)},
1198
1199 {CC "defineClass0", CC "(" DC_Args ")" CLS, FN_PTR(Unsafe_DefineClass0)},
1200 {CC "allocateInstance", CC "(" CLS ")" OBJ, FN_PTR(Unsafe_AllocateInstance)},
1201 {CC "throwException", CC "(" THR ")V", FN_PTR(Unsafe_ThrowException)},
1202 {CC "compareAndSetObject",CC "(" OBJ "J" OBJ "" OBJ ")Z", FN_PTR(Unsafe_CompareAndSetObject)},
1203 {CC "compareAndSetInt", CC "(" OBJ "J""I""I"")Z", FN_PTR(Unsafe_CompareAndSetInt)},
1204 {CC "compareAndSetLong", CC "(" OBJ "J""J""J"")Z", FN_PTR(Unsafe_CompareAndSetLong)},
1205 {CC "compareAndExchangeObject", CC "(" OBJ "J" OBJ "" OBJ ")" OBJ, FN_PTR(Unsafe_CompareAndExchangeObject)},
1206 {CC "compareAndExchangeInt", CC "(" OBJ "J""I""I"")I", FN_PTR(Unsafe_CompareAndExchangeInt)},
1207 {CC "compareAndExchangeLong", CC "(" OBJ "J""J""J"")J", FN_PTR(Unsafe_CompareAndExchangeLong)},
1208
1209 {CC "park", CC "(ZJ)V", FN_PTR(Unsafe_Park)},
1210 {CC "unpark", CC "(" OBJ ")V", FN_PTR(Unsafe_Unpark)},
1211
1212 {CC "getLoadAverage0", CC "([DI)I", FN_PTR(Unsafe_GetLoadAverage0)},
1213
1214 {CC "copyMemory0", CC "(" OBJ "J" OBJ "JJ)V", FN_PTR(Unsafe_CopyMemory0)},
1215 {CC "copySwapMemory0", CC "(" OBJ "J" OBJ "JJJ)V", FN_PTR(Unsafe_CopySwapMemory0)},
1216 {CC "setMemory0", CC "(" OBJ "JJB)V", FN_PTR(Unsafe_SetMemory0)},
1217
1218 {CC "defineAnonymousClass0", CC "(" DAC_Args ")" CLS, FN_PTR(Unsafe_DefineAnonymousClass0)},
1219
1220 {CC "shouldBeInitialized0", CC "(" CLS ")Z", FN_PTR(Unsafe_ShouldBeInitialized0)},
1221
1222 {CC "loadFence", CC "()V", FN_PTR(Unsafe_LoadFence)},
1223 {CC "storeFence", CC "()V", FN_PTR(Unsafe_StoreFence)},
1224 {CC "fullFence", CC "()V", FN_PTR(Unsafe_FullFence)},
1225
1226 {CC "isBigEndian0", CC "()Z", FN_PTR(Unsafe_isBigEndian0)},
1227 {CC "unalignedAccess0", CC "()Z", FN_PTR(Unsafe_unalignedAccess0)}
1228 };
1229
1230 #undef CC
1231 #undef FN_PTR
1232
1233 #undef ADR
1234 #undef LANG
1235 #undef OBJ
1236 #undef CLS
1237 #undef FLD
1238 #undef THR
1239 #undef DC_Args
1240 #undef DAC_Args
1241
1242 #undef DECLARE_GETPUTOOP
1243
1244
1245 // This function is exported, used by NativeLookup.
1246 // The Unsafe_xxx functions above are called only from the interpreter.
1247 // The optimizer looks at names and signatures to recognize
1248 // individual functions.
1249
1250 JVM_ENTRY(void, JVM_RegisterJDKInternalMiscUnsafeMethods(JNIEnv *env, jclass unsafeclass)) {
1251 ThreadToNativeFromVM ttnfv(thread);
1252
1253 int ok = env->RegisterNatives(unsafeclass, jdk_internal_misc_Unsafe_methods, sizeof(jdk_internal_misc_Unsafe_methods)/sizeof(JNINativeMethod));
1254 guarantee(ok == 0, "register jdk.internal.misc.Unsafe natives");
1255 } JVM_END