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/fieldStreams.hpp"
31 #include "oops/objArrayOop.inline.hpp"
32 #include "oops/oop.inline.hpp"
33 #include "prims/jni.h"
34 #include "prims/jvm.h"
35 #include "prims/unsafe.hpp"
36 #include "runtime/atomic.hpp"
37 #include "runtime/globals.hpp"
38 #include "runtime/interfaceSupport.hpp"
39 #include "runtime/orderAccess.inline.hpp"
40 #include "runtime/reflection.hpp"
41 #include "runtime/thread.hpp"
42 #include "runtime/threadSMR.hpp"
43 #include "runtime/vm_version.hpp"
44 #include "services/threadService.hpp"
45 #include "trace/tracing.hpp"
46 #include "utilities/align.hpp"
47 #include "utilities/copy.hpp"
48 #include "utilities/dtrace.hpp"
49 #include "utilities/macros.hpp"
50 #if INCLUDE_ALL_GCS
51 #include "gc/g1/g1SATBCardTableModRefBS.hpp"
52 #endif // INCLUDE_ALL_GCS
53
54 /**
55 * Implementation of the jdk.internal.misc.Unsafe class
56 */
57
58
59 #define MAX_OBJECT_SIZE \
60 ( arrayOopDesc::header_size(T_DOUBLE) * HeapWordSize \
61 + ((julong)max_jint * sizeof(double)) )
62
63
64 #define UNSAFE_ENTRY(result_type, header) \
65 JVM_ENTRY(static result_type, header)
66
67 #define UNSAFE_LEAF(result_type, header) \
68 JVM_LEAF(static result_type, header)
69
70 #define UNSAFE_END JVM_END
71
72
73 static inline void* addr_from_java(jlong addr) {
74 // This assert fails in a variety of ways on 32-bit systems.
75 // It is impossible to predict whether native code that converts
76 // pointers to longs will sign-extend or zero-extend the addresses.
77 //assert(addr == (uintptr_t)addr, "must not be odd high bits");
78 return (void*)(uintptr_t)addr;
79 }
80
81 static inline jlong addr_to_java(void* p) {
82 assert(p == (void*)(uintptr_t)p, "must not be odd high bits");
83 return (uintptr_t)p;
84 }
85
86
87 // Note: The VM's obj_field and related accessors use byte-scaled
88 // ("unscaled") offsets, just as the unsafe methods do.
89
90 // However, the method Unsafe.fieldOffset explicitly declines to
91 // guarantee this. The field offset values manipulated by the Java user
92 // through the Unsafe API are opaque cookies that just happen to be byte
93 // offsets. We represent this state of affairs by passing the cookies
94 // through conversion functions when going between the VM and the Unsafe API.
95 // The conversion functions just happen to be no-ops at present.
96
97 static inline jlong field_offset_to_byte_offset(jlong field_offset) {
98 return field_offset;
99 }
100
101 static inline jlong field_offset_from_byte_offset(jlong byte_offset) {
102 return byte_offset;
103 }
104
105 static inline void* index_oop_from_field_offset_long(oop p, jlong field_offset) {
106 jlong byte_offset = field_offset_to_byte_offset(field_offset);
107
108 #ifdef ASSERT
109 if (p != NULL) {
110 assert(byte_offset >= 0 && byte_offset <= (jlong)MAX_OBJECT_SIZE, "sane offset");
111 if (byte_offset == (jint)byte_offset) {
112 void* ptr_plus_disp = (address)p + byte_offset;
113 assert((void*)p->obj_field_addr<oop>((jint)byte_offset) == ptr_plus_disp,
114 "raw [ptr+disp] must be consistent with oop::field_base");
115 }
116 jlong p_size = HeapWordSize * (jlong)(p->size());
117 assert(byte_offset < p_size, "Unsafe access: offset " INT64_FORMAT " > object's size " INT64_FORMAT, (int64_t)byte_offset, (int64_t)p_size);
118 }
119 #endif
120
121 if (sizeof(char*) == sizeof(jint)) { // (this constant folds!)
122 return (address)p + (jint) byte_offset;
123 } else {
124 return (address)p + byte_offset;
125 }
126 }
127
128 // Externally callable versions:
129 // (Use these in compiler intrinsics which emulate unsafe primitives.)
130 jlong Unsafe_field_offset_to_byte_offset(jlong field_offset) {
131 return field_offset;
132 }
133 jlong Unsafe_field_offset_from_byte_offset(jlong byte_offset) {
134 return byte_offset;
135 }
136
137
138 ///// Data read/writes on the Java heap and in native (off-heap) memory
139
140 /**
141 * Helper class for accessing memory.
142 *
143 * Normalizes values and wraps accesses in
144 * JavaThread::doing_unsafe_access() if needed.
145 */
146 class MemoryAccess : StackObj {
147 JavaThread* _thread;
148 jobject _obj;
149 jlong _offset;
150
151 // Resolves and returns the address of the memory access
152 void* addr() {
153 return index_oop_from_field_offset_long(JNIHandles::resolve(_obj), _offset);
154 }
155
156 template <typename T>
157 T normalize_for_write(T x) {
158 return x;
159 }
160
161 jboolean normalize_for_write(jboolean x) {
162 return x & 1;
163 }
164
165 template <typename T>
166 T normalize_for_read(T x) {
167 return x;
168 }
169
170 jboolean normalize_for_read(jboolean x) {
171 return x != 0;
172 }
173
174 /**
175 * Helper class to wrap memory accesses in JavaThread::doing_unsafe_access()
176 */
177 class GuardUnsafeAccess {
178 JavaThread* _thread;
179 bool _active;
180
181 public:
182 GuardUnsafeAccess(JavaThread* thread, jobject _obj) : _thread(thread) {
183 if (JNIHandles::resolve(_obj) == NULL) {
184 // native/off-heap access which may raise SIGBUS if accessing
185 // memory mapped file data in a region of the file which has
186 // been truncated and is now invalid
187 _thread->set_doing_unsafe_access(true);
188 _active = true;
189 } else {
190 _active = false;
191 }
192 }
193
194 ~GuardUnsafeAccess() {
195 if (_active) {
196 _thread->set_doing_unsafe_access(false);
197 }
198 }
199 };
200
201 public:
202 MemoryAccess(JavaThread* thread, jobject obj, jlong offset)
203 : _thread(thread), _obj(obj), _offset(offset) {
204 }
205
206 template <typename T>
207 T get() {
208 GuardUnsafeAccess guard(_thread, _obj);
209
210 T* p = (T*)addr();
211
212 T x = normalize_for_read(*p);
213
214 return x;
215 }
216
217 template <typename T>
218 void put(T x) {
219 GuardUnsafeAccess guard(_thread, _obj);
220
221 T* p = (T*)addr();
222
223 *p = normalize_for_write(x);
224 }
225
226
227 template <typename T>
228 T get_volatile() {
229 GuardUnsafeAccess guard(_thread, _obj);
230
231 T* p = (T*)addr();
232
233 if (support_IRIW_for_not_multiple_copy_atomic_cpu) {
234 OrderAccess::fence();
235 }
236
237 T x = OrderAccess::load_acquire((volatile T*)p);
238
239 return normalize_for_read(x);
240 }
241
242 template <typename T>
243 void put_volatile(T x) {
244 GuardUnsafeAccess guard(_thread, _obj);
245
246 T* p = (T*)addr();
247
248 OrderAccess::release_store_fence((volatile T*)p, normalize_for_write(x));
249 }
250
251
252 #ifndef SUPPORTS_NATIVE_CX8
253 jlong get_jlong_locked() {
254 GuardUnsafeAccess guard(_thread, _obj);
255
256 MutexLockerEx mu(UnsafeJlong_lock, Mutex::_no_safepoint_check_flag);
257
258 jlong* p = (jlong*)addr();
259
260 jlong x = Atomic::load(p);
261
262 return x;
263 }
264
265 void put_jlong_locked(jlong x) {
266 GuardUnsafeAccess guard(_thread, _obj);
267
268 MutexLockerEx mu(UnsafeJlong_lock, Mutex::_no_safepoint_check_flag);
269
270 jlong* p = (jlong*)addr();
271
272 Atomic::store(normalize_for_write(x), p);
273 }
274 #endif
275 };
276
277 // Get/PutObject must be special-cased, since it works with handles.
278
279 // We could be accessing the referent field in a reference
280 // object. If G1 is enabled then we need to register non-null
281 // referent with the SATB barrier.
282
283 #if INCLUDE_ALL_GCS
284 static bool is_java_lang_ref_Reference_access(oop o, jlong offset) {
285 if (offset == java_lang_ref_Reference::referent_offset && o != NULL) {
286 Klass* k = o->klass();
287 if (InstanceKlass::cast(k)->reference_type() != REF_NONE) {
288 assert(InstanceKlass::cast(k)->is_subclass_of(SystemDictionary::Reference_klass()), "sanity");
289 return true;
290 }
291 }
292 return false;
293 }
294 #endif
295
296 static void ensure_satb_referent_alive(oop o, jlong offset, oop v) {
297 #if INCLUDE_ALL_GCS
298 if (UseG1GC && v != NULL && is_java_lang_ref_Reference_access(o, offset)) {
299 G1SATBCardTableModRefBS::enqueue(v);
300 }
301 #endif
302 }
303
304 // These functions allow a null base pointer with an arbitrary address.
305 // But if the base pointer is non-null, the offset should make some sense.
306 // That is, it should be in the range [0, MAX_OBJECT_SIZE].
307 UNSAFE_ENTRY(jobject, Unsafe_GetObject(JNIEnv *env, jobject unsafe, jobject obj, jlong offset)) {
308 oop p = JNIHandles::resolve(obj);
309 oop v;
310
311 if (UseCompressedOops) {
312 narrowOop n = *(narrowOop*)index_oop_from_field_offset_long(p, offset);
313 v = oopDesc::decode_heap_oop(n);
314 } else {
315 v = *(oop*)index_oop_from_field_offset_long(p, offset);
316 }
317
318 ensure_satb_referent_alive(p, offset, v);
319
320 return JNIHandles::make_local(env, v);
321 } UNSAFE_END
322
323 UNSAFE_ENTRY(void, Unsafe_PutObject(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jobject x_h)) {
324 oop x = JNIHandles::resolve(x_h);
325 oop p = JNIHandles::resolve(obj);
326
327 if (UseCompressedOops) {
328 oop_store((narrowOop*)index_oop_from_field_offset_long(p, offset), x);
329 } else {
330 oop_store((oop*)index_oop_from_field_offset_long(p, offset), x);
331 }
332 } UNSAFE_END
333
334 UNSAFE_ENTRY(jobject, Unsafe_GetObjectVolatile(JNIEnv *env, jobject unsafe, jobject obj, jlong offset)) {
335 oop p = JNIHandles::resolve(obj);
336 void* addr = index_oop_from_field_offset_long(p, offset);
337
338 volatile oop v;
339
340 if (support_IRIW_for_not_multiple_copy_atomic_cpu) {
341 OrderAccess::fence();
342 }
343
344 if (UseCompressedOops) {
345 volatile narrowOop n = *(volatile narrowOop*) addr;
346 (void)const_cast<oop&>(v = oopDesc::decode_heap_oop(n));
347 } else {
348 (void)const_cast<oop&>(v = *(volatile oop*) addr);
349 }
350
351 ensure_satb_referent_alive(p, offset, v);
352
353 OrderAccess::acquire();
354 return JNIHandles::make_local(env, v);
355 } UNSAFE_END
356
357 UNSAFE_ENTRY(void, Unsafe_PutObjectVolatile(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jobject x_h)) {
358 oop x = JNIHandles::resolve(x_h);
359 oop p = JNIHandles::resolve(obj);
360 void* addr = index_oop_from_field_offset_long(p, offset);
361 OrderAccess::release();
362
363 if (UseCompressedOops) {
364 oop_store((narrowOop*)addr, x);
365 } else {
366 oop_store((oop*)addr, x);
367 }
368
369 OrderAccess::fence();
370 } UNSAFE_END
371
372 UNSAFE_ENTRY(jobject, Unsafe_GetUncompressedObject(JNIEnv *env, jobject unsafe, jlong addr)) {
373 oop v = *(oop*) (address) addr;
374
375 return JNIHandles::make_local(env, v);
376 } UNSAFE_END
377
378 #ifndef SUPPORTS_NATIVE_CX8
379
380 // VM_Version::supports_cx8() is a surrogate for 'supports atomic long memory ops'.
381 //
382 // On platforms which do not support atomic compare-and-swap of jlong (8 byte)
383 // values we have to use a lock-based scheme to enforce atomicity. This has to be
384 // applied to all Unsafe operations that set the value of a jlong field. Even so
385 // the compareAndSetLong operation will not be atomic with respect to direct stores
386 // to the field from Java code. It is important therefore that any Java code that
387 // utilizes these Unsafe jlong operations does not perform direct stores. To permit
388 // direct loads of the field from Java code we must also use Atomic::store within the
389 // locked regions. And for good measure, in case there are direct stores, we also
390 // employ Atomic::load within those regions. Note that the field in question must be
391 // volatile and so must have atomic load/store accesses applied at the Java level.
392 //
393 // The locking scheme could utilize a range of strategies for controlling the locking
394 // granularity: from a lock per-field through to a single global lock. The latter is
395 // the simplest and is used for the current implementation. Note that the Java object
396 // that contains the field, can not, in general, be used for locking. To do so can lead
397 // to deadlocks as we may introduce locking into what appears to the Java code to be a
398 // lock-free path.
399 //
400 // As all the locked-regions are very short and themselves non-blocking we can treat
401 // them as leaf routines and elide safepoint checks (ie we don't perform any thread
402 // state transitions even when blocking for the lock). Note that if we do choose to
403 // add safepoint checks and thread state transitions, we must ensure that we calculate
404 // the address of the field _after_ we have acquired the lock, else the object may have
405 // been moved by the GC
406
407 UNSAFE_ENTRY(jlong, Unsafe_GetLongVolatile(JNIEnv *env, jobject unsafe, jobject obj, jlong offset)) {
408 if (VM_Version::supports_cx8()) {
409 return MemoryAccess(thread, obj, offset).get_volatile<jlong>();
410 } else {
411 return MemoryAccess(thread, obj, offset).get_jlong_locked();
412 }
413 } UNSAFE_END
414
415 UNSAFE_ENTRY(void, Unsafe_PutLongVolatile(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jlong x)) {
416 if (VM_Version::supports_cx8()) {
417 MemoryAccess(thread, obj, offset).put_volatile<jlong>(x);
418 } else {
419 MemoryAccess(thread, obj, offset).put_jlong_locked(x);
420 }
421 } UNSAFE_END
422
423 #endif // not SUPPORTS_NATIVE_CX8
424
425 UNSAFE_LEAF(jboolean, Unsafe_isBigEndian0(JNIEnv *env, jobject unsafe)) {
426 #ifdef VM_LITTLE_ENDIAN
427 return false;
428 #else
429 return true;
430 #endif
431 } UNSAFE_END
432
433 UNSAFE_LEAF(jint, Unsafe_unalignedAccess0(JNIEnv *env, jobject unsafe)) {
434 return UseUnalignedAccesses;
435 } UNSAFE_END
436
437 #define DEFINE_GETSETOOP(java_type, Type) \
438 \
439 UNSAFE_ENTRY(java_type, Unsafe_Get##Type(JNIEnv *env, jobject unsafe, jobject obj, jlong offset)) { \
440 return MemoryAccess(thread, obj, offset).get<java_type>(); \
441 } UNSAFE_END \
442 \
443 UNSAFE_ENTRY(void, Unsafe_Put##Type(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, java_type x)) { \
444 MemoryAccess(thread, obj, offset).put<java_type>(x); \
445 } UNSAFE_END \
446 \
447 // END DEFINE_GETSETOOP.
448
449 DEFINE_GETSETOOP(jboolean, Boolean)
450 DEFINE_GETSETOOP(jbyte, Byte)
451 DEFINE_GETSETOOP(jshort, Short);
452 DEFINE_GETSETOOP(jchar, Char);
453 DEFINE_GETSETOOP(jint, Int);
454 DEFINE_GETSETOOP(jlong, Long);
455 DEFINE_GETSETOOP(jfloat, Float);
456 DEFINE_GETSETOOP(jdouble, Double);
457
458 #undef DEFINE_GETSETOOP
459
460 #define DEFINE_GETSETOOP_VOLATILE(java_type, Type) \
461 \
462 UNSAFE_ENTRY(java_type, Unsafe_Get##Type##Volatile(JNIEnv *env, jobject unsafe, jobject obj, jlong offset)) { \
463 return MemoryAccess(thread, obj, offset).get_volatile<java_type>(); \
464 } UNSAFE_END \
465 \
466 UNSAFE_ENTRY(void, Unsafe_Put##Type##Volatile(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, java_type x)) { \
467 MemoryAccess(thread, obj, offset).put_volatile<java_type>(x); \
468 } UNSAFE_END \
469 \
470 // END DEFINE_GETSETOOP_VOLATILE.
471
472 DEFINE_GETSETOOP_VOLATILE(jboolean, Boolean)
473 DEFINE_GETSETOOP_VOLATILE(jbyte, Byte)
474 DEFINE_GETSETOOP_VOLATILE(jshort, Short);
475 DEFINE_GETSETOOP_VOLATILE(jchar, Char);
476 DEFINE_GETSETOOP_VOLATILE(jint, Int);
477 DEFINE_GETSETOOP_VOLATILE(jfloat, Float);
478 DEFINE_GETSETOOP_VOLATILE(jdouble, Double);
479
480 #ifdef SUPPORTS_NATIVE_CX8
481 DEFINE_GETSETOOP_VOLATILE(jlong, Long);
482 #endif
483
484 #undef DEFINE_GETSETOOP_VOLATILE
485
486 UNSAFE_LEAF(void, Unsafe_LoadFence(JNIEnv *env, jobject unsafe)) {
487 OrderAccess::acquire();
488 } UNSAFE_END
489
490 UNSAFE_LEAF(void, Unsafe_StoreFence(JNIEnv *env, jobject unsafe)) {
491 OrderAccess::release();
492 } UNSAFE_END
493
494 UNSAFE_LEAF(void, Unsafe_FullFence(JNIEnv *env, jobject unsafe)) {
495 OrderAccess::fence();
496 } UNSAFE_END
497
498 ////// Allocation requests
499
500 UNSAFE_ENTRY(jobject, Unsafe_AllocateInstance(JNIEnv *env, jobject unsafe, jclass cls)) {
501 ThreadToNativeFromVM ttnfv(thread);
502 return env->AllocObject(cls);
503 } UNSAFE_END
504
505 UNSAFE_ENTRY(jlong, Unsafe_AllocateMemory0(JNIEnv *env, jobject unsafe, jlong size)) {
506 size_t sz = (size_t)size;
507
508 sz = align_up(sz, HeapWordSize);
509 void* x = os::malloc(sz, mtInternal);
510
511 return addr_to_java(x);
512 } UNSAFE_END
513
514 UNSAFE_ENTRY(jlong, Unsafe_ReallocateMemory0(JNIEnv *env, jobject unsafe, jlong addr, jlong size)) {
515 void* p = addr_from_java(addr);
516 size_t sz = (size_t)size;
517 sz = align_up(sz, HeapWordSize);
518
519 void* x = os::realloc(p, sz, mtInternal);
520
521 return addr_to_java(x);
522 } UNSAFE_END
523
524 UNSAFE_ENTRY(void, Unsafe_FreeMemory0(JNIEnv *env, jobject unsafe, jlong addr)) {
525 void* p = addr_from_java(addr);
526
527 os::free(p);
528 } UNSAFE_END
529
530 UNSAFE_ENTRY(void, Unsafe_SetMemory0(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jlong size, jbyte value)) {
531 size_t sz = (size_t)size;
532
533 oop base = JNIHandles::resolve(obj);
534 void* p = index_oop_from_field_offset_long(base, offset);
535
536 Copy::fill_to_memory_atomic(p, sz, value);
537 } UNSAFE_END
538
539 UNSAFE_ENTRY(void, Unsafe_CopyMemory0(JNIEnv *env, jobject unsafe, jobject srcObj, jlong srcOffset, jobject dstObj, jlong dstOffset, jlong size)) {
540 size_t sz = (size_t)size;
541
542 oop srcp = JNIHandles::resolve(srcObj);
543 oop dstp = JNIHandles::resolve(dstObj);
544
545 void* src = index_oop_from_field_offset_long(srcp, srcOffset);
546 void* dst = index_oop_from_field_offset_long(dstp, dstOffset);
547
548 Copy::conjoint_memory_atomic(src, dst, sz);
549 } UNSAFE_END
550
551 // This function is a leaf since if the source and destination are both in native memory
552 // the copy may potentially be very large, and we don't want to disable GC if we can avoid it.
553 // If either source or destination (or both) are on the heap, the function will enter VM using
554 // JVM_ENTRY_FROM_LEAF
555 UNSAFE_LEAF(void, Unsafe_CopySwapMemory0(JNIEnv *env, jobject unsafe, jobject srcObj, jlong srcOffset, jobject dstObj, jlong dstOffset, jlong size, jlong elemSize)) {
556 size_t sz = (size_t)size;
557 size_t esz = (size_t)elemSize;
558
559 if (srcObj == NULL && dstObj == NULL) {
560 // Both src & dst are in native memory
561 address src = (address)srcOffset;
562 address dst = (address)dstOffset;
563
564 Copy::conjoint_swap(src, dst, sz, esz);
565 } else {
566 // At least one of src/dst are on heap, transition to VM to access raw pointers
567
568 JVM_ENTRY_FROM_LEAF(env, void, Unsafe_CopySwapMemory0) {
569 oop srcp = JNIHandles::resolve(srcObj);
570 oop dstp = JNIHandles::resolve(dstObj);
571
572 address src = (address)index_oop_from_field_offset_long(srcp, srcOffset);
573 address dst = (address)index_oop_from_field_offset_long(dstp, dstOffset);
574
575 Copy::conjoint_swap(src, dst, sz, esz);
576 } JVM_END
577 }
578 } UNSAFE_END
579
580 ////// Random queries
581
582 UNSAFE_LEAF(jint, Unsafe_AddressSize0(JNIEnv *env, jobject unsafe)) {
583 return sizeof(void*);
584 } UNSAFE_END
585
586 UNSAFE_LEAF(jint, Unsafe_PageSize()) {
587 return os::vm_page_size();
588 } UNSAFE_END
589
590 static jlong find_field_offset(jclass clazz, jstring name, TRAPS) {
591 assert(clazz != NULL, "clazz must not be NULL");
592 assert(name != NULL, "name must not be NULL");
593
594 ResourceMark rm(THREAD);
595 char *utf_name = java_lang_String::as_utf8_string(JNIHandles::resolve_non_null(name));
596
597 InstanceKlass* k = InstanceKlass::cast(java_lang_Class::as_Klass(JNIHandles::resolve_non_null(clazz)));
598
599 jint offset = -1;
600 for (JavaFieldStream fs(k); !fs.done(); fs.next()) {
601 Symbol *name = fs.name();
602 if (name->equals(utf_name)) {
603 offset = fs.offset();
604 break;
605 }
606 }
607 if (offset < 0) {
608 THROW_0(vmSymbols::java_lang_InternalError());
609 }
610 return field_offset_from_byte_offset(offset);
611 }
612
613 static jlong find_field_offset(jobject field, int must_be_static, TRAPS) {
614 assert(field != NULL, "field must not be NULL");
615
616 oop reflected = JNIHandles::resolve_non_null(field);
617 oop mirror = java_lang_reflect_Field::clazz(reflected);
618 Klass* k = java_lang_Class::as_Klass(mirror);
619 int slot = java_lang_reflect_Field::slot(reflected);
620 int modifiers = java_lang_reflect_Field::modifiers(reflected);
621
622 if (must_be_static >= 0) {
623 int really_is_static = ((modifiers & JVM_ACC_STATIC) != 0);
624 if (must_be_static != really_is_static) {
625 THROW_0(vmSymbols::java_lang_IllegalArgumentException());
626 }
627 }
628
629 int offset = InstanceKlass::cast(k)->field_offset(slot);
630 return field_offset_from_byte_offset(offset);
631 }
632
633 UNSAFE_ENTRY(jlong, Unsafe_ObjectFieldOffset0(JNIEnv *env, jobject unsafe, jobject field)) {
634 return find_field_offset(field, 0, THREAD);
635 } UNSAFE_END
636
637 UNSAFE_ENTRY(jlong, Unsafe_ObjectFieldOffset1(JNIEnv *env, jobject unsafe, jclass c, jstring name)) {
638 return find_field_offset(c, name, THREAD);
639 } UNSAFE_END
640
641 UNSAFE_ENTRY(jlong, Unsafe_StaticFieldOffset0(JNIEnv *env, jobject unsafe, jobject field)) {
642 return find_field_offset(field, 1, THREAD);
643 } UNSAFE_END
644
645 UNSAFE_ENTRY(jobject, Unsafe_StaticFieldBase0(JNIEnv *env, jobject unsafe, jobject field)) {
646 assert(field != NULL, "field must not be NULL");
647
648 // Note: In this VM implementation, a field address is always a short
649 // offset from the base of a a klass metaobject. Thus, the full dynamic
650 // range of the return type is never used. However, some implementations
651 // might put the static field inside an array shared by many classes,
652 // or even at a fixed address, in which case the address could be quite
653 // large. In that last case, this function would return NULL, since
654 // the address would operate alone, without any base pointer.
655
656 oop reflected = JNIHandles::resolve_non_null(field);
657 oop mirror = java_lang_reflect_Field::clazz(reflected);
658 int modifiers = java_lang_reflect_Field::modifiers(reflected);
659
660 if ((modifiers & JVM_ACC_STATIC) == 0) {
661 THROW_0(vmSymbols::java_lang_IllegalArgumentException());
662 }
663
664 return JNIHandles::make_local(env, mirror);
665 } UNSAFE_END
666
667 UNSAFE_ENTRY(void, Unsafe_EnsureClassInitialized0(JNIEnv *env, jobject unsafe, jobject clazz)) {
668 assert(clazz != NULL, "clazz must not be NULL");
669
670 oop mirror = JNIHandles::resolve_non_null(clazz);
671
672 Klass* klass = java_lang_Class::as_Klass(mirror);
673 if (klass != NULL && klass->should_be_initialized()) {
674 InstanceKlass* k = InstanceKlass::cast(klass);
675 k->initialize(CHECK);
676 }
677 }
678 UNSAFE_END
679
680 UNSAFE_ENTRY(jboolean, Unsafe_ShouldBeInitialized0(JNIEnv *env, jobject unsafe, jobject clazz)) {
681 assert(clazz != NULL, "clazz must not be NULL");
682
683 oop mirror = JNIHandles::resolve_non_null(clazz);
684 Klass* klass = java_lang_Class::as_Klass(mirror);
685
686 if (klass != NULL && klass->should_be_initialized()) {
687 return true;
688 }
689
690 return false;
691 }
692 UNSAFE_END
693
694 static void getBaseAndScale(int& base, int& scale, jclass clazz, TRAPS) {
695 assert(clazz != NULL, "clazz must not be NULL");
696
697 oop mirror = JNIHandles::resolve_non_null(clazz);
698 Klass* k = java_lang_Class::as_Klass(mirror);
699
700 if (k == NULL || !k->is_array_klass()) {
701 THROW(vmSymbols::java_lang_InvalidClassException());
702 } else if (k->is_objArray_klass()) {
703 base = arrayOopDesc::base_offset_in_bytes(T_OBJECT);
704 scale = heapOopSize;
705 } else if (k->is_typeArray_klass()) {
706 TypeArrayKlass* tak = TypeArrayKlass::cast(k);
707 base = tak->array_header_in_bytes();
708 assert(base == arrayOopDesc::base_offset_in_bytes(tak->element_type()), "array_header_size semantics ok");
709 scale = (1 << tak->log2_element_size());
710 } else {
711 ShouldNotReachHere();
712 }
713 }
714
715 UNSAFE_ENTRY(jint, Unsafe_ArrayBaseOffset0(JNIEnv *env, jobject unsafe, jclass clazz)) {
716 int base = 0, scale = 0;
717 getBaseAndScale(base, scale, clazz, CHECK_0);
718
719 return field_offset_from_byte_offset(base);
720 } UNSAFE_END
721
722
723 UNSAFE_ENTRY(jint, Unsafe_ArrayIndexScale0(JNIEnv *env, jobject unsafe, jclass clazz)) {
724 int base = 0, scale = 0;
725 getBaseAndScale(base, scale, clazz, CHECK_0);
726
727 // This VM packs both fields and array elements down to the byte.
728 // But watch out: If this changes, so that array references for
729 // a given primitive type (say, T_BOOLEAN) use different memory units
730 // than fields, this method MUST return zero for such arrays.
731 // For example, the VM used to store sub-word sized fields in full
732 // words in the object layout, so that accessors like getByte(Object,int)
733 // did not really do what one might expect for arrays. Therefore,
734 // this function used to report a zero scale factor, so that the user
735 // would know not to attempt to access sub-word array elements.
736 // // Code for unpacked fields:
737 // if (scale < wordSize) return 0;
738
739 // The following allows for a pretty general fieldOffset cookie scheme,
740 // but requires it to be linear in byte offset.
741 return field_offset_from_byte_offset(scale) - field_offset_from_byte_offset(0);
742 } UNSAFE_END
743
744
745 static inline void throw_new(JNIEnv *env, const char *ename) {
746 jclass cls = env->FindClass(ename);
747 if (env->ExceptionCheck()) {
748 env->ExceptionClear();
749 tty->print_cr("Unsafe: cannot throw %s because FindClass has failed", ename);
750 return;
751 }
752
753 env->ThrowNew(cls, NULL);
754 }
755
756 static jclass Unsafe_DefineClass_impl(JNIEnv *env, jstring name, jbyteArray data, int offset, int length, jobject loader, jobject pd) {
757 // Code lifted from JDK 1.3 ClassLoader.c
758
759 jbyte *body;
760 char *utfName = NULL;
761 jclass result = 0;
762 char buf[128];
763
764 assert(data != NULL, "Class bytes must not be NULL");
765 assert(length >= 0, "length must not be negative: %d", length);
766
767 if (UsePerfData) {
768 ClassLoader::unsafe_defineClassCallCounter()->inc();
769 }
770
771 body = NEW_C_HEAP_ARRAY(jbyte, length, mtInternal);
772 if (body == NULL) {
773 throw_new(env, "java/lang/OutOfMemoryError");
774 return 0;
775 }
776
777 env->GetByteArrayRegion(data, offset, length, body);
778 if (env->ExceptionOccurred()) {
779 goto free_body;
780 }
781
782 if (name != NULL) {
783 uint len = env->GetStringUTFLength(name);
784 int unicode_len = env->GetStringLength(name);
785
786 if (len >= sizeof(buf)) {
787 utfName = NEW_C_HEAP_ARRAY(char, len + 1, mtInternal);
788 if (utfName == NULL) {
789 throw_new(env, "java/lang/OutOfMemoryError");
790 goto free_body;
791 }
792 } else {
793 utfName = buf;
794 }
795
796 env->GetStringUTFRegion(name, 0, unicode_len, utfName);
797
798 for (uint i = 0; i < len; i++) {
799 if (utfName[i] == '.') utfName[i] = '/';
800 }
801 }
802
803 result = JVM_DefineClass(env, utfName, loader, body, length, pd);
804
805 if (utfName && utfName != buf) {
806 FREE_C_HEAP_ARRAY(char, utfName);
807 }
808
809 free_body:
810 FREE_C_HEAP_ARRAY(jbyte, body);
811 return result;
812 }
813
814
815 UNSAFE_ENTRY(jclass, Unsafe_DefineClass0(JNIEnv *env, jobject unsafe, jstring name, jbyteArray data, int offset, int length, jobject loader, jobject pd)) {
816 ThreadToNativeFromVM ttnfv(thread);
817
818 return Unsafe_DefineClass_impl(env, name, data, offset, length, loader, pd);
819 } UNSAFE_END
820
821
822 // define a class but do not make it known to the class loader or system dictionary
823 // - host_class: supplies context for linkage, access control, protection domain, and class loader
824 // if host_class is itself anonymous then it is replaced with its host class.
825 // - data: bytes of a class file, a raw memory address (length gives the number of bytes)
826 // - cp_patches: where non-null entries exist, they replace corresponding CP entries in data
827
828 // When you load an anonymous class U, it works as if you changed its name just before loading,
829 // to a name that you will never use again. Since the name is lost, no other class can directly
830 // link to any member of U. Just after U is loaded, the only way to use it is reflectively,
831 // through java.lang.Class methods like Class.newInstance.
832
833 // The package of an anonymous class must either match its host's class's package or be in the
834 // unnamed package. If it is in the unnamed package then it will be put in its host class's
835 // package.
836 //
837
838 // Access checks for linkage sites within U continue to follow the same rules as for named classes.
839 // An anonymous class also has special privileges to access any member of its host class.
840 // This is the main reason why this loading operation is unsafe. The purpose of this is to
841 // allow language implementations to simulate "open classes"; a host class in effect gets
842 // new code when an anonymous class is loaded alongside it. A less convenient but more
843 // standard way to do this is with reflection, which can also be set to ignore access
844 // restrictions.
845
846 // Access into an anonymous class is possible only through reflection. Therefore, there
847 // are no special access rules for calling into an anonymous class. The relaxed access
848 // rule for the host class is applied in the opposite direction: A host class reflectively
849 // access one of its anonymous classes.
850
851 // If you load the same bytecodes twice, you get two different classes. You can reload
852 // the same bytecodes with or without varying CP patches.
853
854 // By using the CP patching array, you can have a new anonymous class U2 refer to an older one U1.
855 // The bytecodes for U2 should refer to U1 by a symbolic name (doesn't matter what the name is).
856 // The CONSTANT_Class entry for that name can be patched to refer directly to U1.
857
858 // This allows, for example, U2 to use U1 as a superclass or super-interface, or as
859 // an outer class (so that U2 is an anonymous inner class of anonymous U1).
860 // It is not possible for a named class, or an older anonymous class, to refer by
861 // name (via its CP) to a newer anonymous class.
862
863 // CP patching may also be used to modify (i.e., hack) the names of methods, classes,
864 // or type descriptors used in the loaded anonymous class.
865
866 // Finally, CP patching may be used to introduce "live" objects into the constant pool,
867 // instead of "dead" strings. A compiled statement like println((Object)"hello") can
868 // be changed to println(greeting), where greeting is an arbitrary object created before
869 // the anonymous class is loaded. This is useful in dynamic languages, in which
870 // various kinds of metaobjects must be introduced as constants into bytecode.
871 // Note the cast (Object), which tells the verifier to expect an arbitrary object,
872 // not just a literal string. For such ldc instructions, the verifier uses the
873 // type Object instead of String, if the loaded constant is not in fact a String.
874
875 static InstanceKlass*
876 Unsafe_DefineAnonymousClass_impl(JNIEnv *env,
877 jclass host_class, jbyteArray data, jobjectArray cp_patches_jh,
878 u1** temp_alloc,
879 TRAPS) {
880 assert(host_class != NULL, "host_class must not be NULL");
881 assert(data != NULL, "data must not be NULL");
882
883 if (UsePerfData) {
884 ClassLoader::unsafe_defineClassCallCounter()->inc();
885 }
886
887 jint length = typeArrayOop(JNIHandles::resolve_non_null(data))->length();
888 assert(length >= 0, "class_bytes_length must not be negative: %d", length);
889
890 int class_bytes_length = (int) length;
891
892 u1* class_bytes = NEW_C_HEAP_ARRAY(u1, length, mtInternal);
893 if (class_bytes == NULL) {
894 THROW_0(vmSymbols::java_lang_OutOfMemoryError());
895 }
896
897 // caller responsible to free it:
898 *temp_alloc = class_bytes;
899
900 jbyte* array_base = typeArrayOop(JNIHandles::resolve_non_null(data))->byte_at_addr(0);
901 Copy::conjoint_jbytes(array_base, class_bytes, length);
902
903 objArrayHandle cp_patches_h;
904 if (cp_patches_jh != NULL) {
905 oop p = JNIHandles::resolve_non_null(cp_patches_jh);
906 assert(p->is_objArray(), "cp_patches must be an object[]");
907 cp_patches_h = objArrayHandle(THREAD, (objArrayOop)p);
908 }
909
910 const Klass* host_klass = java_lang_Class::as_Klass(JNIHandles::resolve_non_null(host_class));
911
912 // Make sure it's the real host class, not another anonymous class.
913 while (host_klass != NULL && host_klass->is_instance_klass() &&
914 InstanceKlass::cast(host_klass)->is_anonymous()) {
915 host_klass = InstanceKlass::cast(host_klass)->host_klass();
916 }
917
918 // Primitive types have NULL Klass* fields in their java.lang.Class instances.
919 if (host_klass == NULL) {
920 THROW_MSG_0(vmSymbols::java_lang_IllegalArgumentException(), "Host class is null");
921 }
922
923 assert(host_klass->is_instance_klass(), "Host class must be an instance class");
924
925 const char* host_source = host_klass->external_name();
926 Handle host_loader(THREAD, host_klass->class_loader());
927 Handle host_domain(THREAD, host_klass->protection_domain());
928
929 GrowableArray<Handle>* cp_patches = NULL;
930
931 if (cp_patches_h.not_null()) {
932 int alen = cp_patches_h->length();
933
934 for (int i = alen-1; i >= 0; i--) {
935 oop p = cp_patches_h->obj_at(i);
936 if (p != NULL) {
937 Handle patch(THREAD, p);
938
939 if (cp_patches == NULL) {
940 cp_patches = new GrowableArray<Handle>(i+1, i+1, Handle());
941 }
942
943 cp_patches->at_put(i, patch);
944 }
945 }
946 }
947
948 ClassFileStream st(class_bytes, class_bytes_length, host_source, ClassFileStream::verify);
949
950 Symbol* no_class_name = NULL;
951 Klass* anonk = SystemDictionary::parse_stream(no_class_name,
952 host_loader,
953 host_domain,
954 &st,
955 InstanceKlass::cast(host_klass),
956 cp_patches,
957 CHECK_NULL);
958 if (anonk == NULL) {
959 return NULL;
960 }
961
962 return InstanceKlass::cast(anonk);
963 }
964
965 UNSAFE_ENTRY(jclass, Unsafe_DefineAnonymousClass0(JNIEnv *env, jobject unsafe, jclass host_class, jbyteArray data, jobjectArray cp_patches_jh)) {
966 ResourceMark rm(THREAD);
967
968 jobject res_jh = NULL;
969 u1* temp_alloc = NULL;
970
971 InstanceKlass* anon_klass = Unsafe_DefineAnonymousClass_impl(env, host_class, data, cp_patches_jh, &temp_alloc, THREAD);
972 if (anon_klass != NULL) {
973 res_jh = JNIHandles::make_local(env, anon_klass->java_mirror());
974 }
975
976 // try/finally clause:
977 if (temp_alloc != NULL) {
978 FREE_C_HEAP_ARRAY(u1, temp_alloc);
979 }
980
981 // The anonymous class loader data has been artificially been kept alive to
982 // this point. The mirror and any instances of this class have to keep
983 // it alive afterwards.
984 if (anon_klass != NULL) {
985 anon_klass->class_loader_data()->dec_keep_alive();
986 }
987
988 // let caller initialize it as needed...
989
990 return (jclass) res_jh;
991 } UNSAFE_END
992
993
994
995 UNSAFE_ENTRY(void, Unsafe_ThrowException(JNIEnv *env, jobject unsafe, jthrowable thr)) {
996 ThreadToNativeFromVM ttnfv(thread);
997 env->Throw(thr);
998 } UNSAFE_END
999
1000 // JSR166 ------------------------------------------------------------------
1001
1002 UNSAFE_ENTRY(jobject, Unsafe_CompareAndExchangeObject(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jobject e_h, jobject x_h)) {
1003 oop x = JNIHandles::resolve(x_h);
1004 oop e = JNIHandles::resolve(e_h);
1005 oop p = JNIHandles::resolve(obj);
1006 HeapWord* addr = (HeapWord *)index_oop_from_field_offset_long(p, offset);
1007 oop res = oopDesc::atomic_compare_exchange_oop(x, addr, e, true);
1008 if (res == e) {
1009 update_barrier_set((void*)addr, x);
1010 }
1011 return JNIHandles::make_local(env, res);
1012 } UNSAFE_END
1013
1014 UNSAFE_ENTRY(jint, Unsafe_CompareAndExchangeInt(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jint e, jint x)) {
1015 oop p = JNIHandles::resolve(obj);
1016 jint* addr = (jint *) index_oop_from_field_offset_long(p, offset);
1017
1018 return (jint)(Atomic::cmpxchg(x, addr, e));
1019 } UNSAFE_END
1020
1021 UNSAFE_ENTRY(jlong, Unsafe_CompareAndExchangeLong(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jlong e, jlong x)) {
1022 Handle p(THREAD, JNIHandles::resolve(obj));
1023 jlong* addr = (jlong*)index_oop_from_field_offset_long(p(), offset);
1024
1025 #ifdef SUPPORTS_NATIVE_CX8
1026 return (jlong)(Atomic::cmpxchg(x, addr, e));
1027 #else
1028 if (VM_Version::supports_cx8()) {
1029 return (jlong)(Atomic::cmpxchg(x, addr, e));
1030 } else {
1031 MutexLockerEx mu(UnsafeJlong_lock, Mutex::_no_safepoint_check_flag);
1032
1033 jlong val = Atomic::load(addr);
1034 if (val == e) {
1035 Atomic::store(x, addr);
1036 }
1037 return val;
1038 }
1039 #endif
1040 } UNSAFE_END
1041
1042 UNSAFE_ENTRY(jboolean, Unsafe_CompareAndSetObject(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jobject e_h, jobject x_h)) {
1043 oop x = JNIHandles::resolve(x_h);
1044 oop e = JNIHandles::resolve(e_h);
1045 oop p = JNIHandles::resolve(obj);
1046 HeapWord* addr = (HeapWord *)index_oop_from_field_offset_long(p, offset);
1047 oop res = oopDesc::atomic_compare_exchange_oop(x, addr, e, true);
1048 if (res != e) {
1049 return false;
1050 }
1051
1052 update_barrier_set((void*)addr, x);
1053
1054 return true;
1055 } UNSAFE_END
1056
1057 UNSAFE_ENTRY(jboolean, Unsafe_CompareAndSetInt(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jint e, jint x)) {
1058 oop p = JNIHandles::resolve(obj);
1059 jint* addr = (jint *)index_oop_from_field_offset_long(p, offset);
1060
1061 return (jint)(Atomic::cmpxchg(x, addr, e)) == e;
1062 } UNSAFE_END
1063
1064 UNSAFE_ENTRY(jboolean, Unsafe_CompareAndSetLong(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jlong e, jlong x)) {
1065 Handle p(THREAD, JNIHandles::resolve(obj));
1066 jlong* addr = (jlong*)index_oop_from_field_offset_long(p(), offset);
1067
1068 #ifdef SUPPORTS_NATIVE_CX8
1069 return (jlong)(Atomic::cmpxchg(x, addr, e)) == e;
1070 #else
1071 if (VM_Version::supports_cx8()) {
1072 return (jlong)(Atomic::cmpxchg(x, addr, e)) == e;
1073 } else {
1074 MutexLockerEx mu(UnsafeJlong_lock, Mutex::_no_safepoint_check_flag);
1075
1076 jlong val = Atomic::load(addr);
1077 if (val != e) {
1078 return false;
1079 }
1080
1081 Atomic::store(x, addr);
1082 return true;
1083 }
1084 #endif
1085 } UNSAFE_END
1086
1087 UNSAFE_ENTRY(void, Unsafe_Park(JNIEnv *env, jobject unsafe, jboolean isAbsolute, jlong time)) {
1088 EventThreadPark event;
1089 HOTSPOT_THREAD_PARK_BEGIN((uintptr_t) thread->parker(), (int) isAbsolute, time);
1090
1091 JavaThreadParkedState jtps(thread, time != 0);
1092 thread->parker()->park(isAbsolute != 0, time);
1093
1094 HOTSPOT_THREAD_PARK_END((uintptr_t) thread->parker());
1095
1096 if (event.should_commit()) {
1097 oop obj = thread->current_park_blocker();
1098 event.set_parkedClass((obj != NULL) ? obj->klass() : NULL);
1099 event.set_timeout(time);
1100 event.set_address((obj != NULL) ? (TYPE_ADDRESS) cast_from_oop<uintptr_t>(obj) : 0);
1101 event.commit();
1102 }
1103 } UNSAFE_END
1104
1105 UNSAFE_ENTRY(void, Unsafe_Unpark(JNIEnv *env, jobject unsafe, jobject jthread)) {
1106 Parker* p = NULL;
1107
1108 if (jthread != NULL) {
1109 ThreadsListHandle tlh;
1110 JavaThread* thr = NULL;
1111 oop java_thread = NULL;
1112 (void) tlh.cv_internal_thread_to_JavaThread(jthread, &thr, &java_thread);
1113 if (java_thread != NULL) {
1114 // This is a valid oop.
1115 jlong lp = java_lang_Thread::park_event(java_thread);
1116 if (lp != 0) {
1117 // This cast is OK even though the jlong might have been read
1118 // non-atomically on 32bit systems, since there, one word will
1119 // always be zero anyway and the value set is always the same
1120 p = (Parker*)addr_from_java(lp);
1121 } else {
1122 // Not cached in the java.lang.Thread oop yet (could be an
1123 // older version of library).
1124 if (thr != NULL) {
1125 // The JavaThread is alive.
1126 p = thr->parker();
1127 if (p != NULL) {
1128 // Cache the Parker in the java.lang.Thread oop for next time.
1129 java_lang_Thread::set_park_event(java_thread, addr_to_java(p));
1130 }
1131 }
1132 }
1133 }
1134 } // ThreadsListHandle is destroyed here.
1135
1136 if (p != NULL) {
1137 HOTSPOT_THREAD_UNPARK((uintptr_t) p);
1138 p->unpark();
1139 }
1140 } UNSAFE_END
1141
1142 UNSAFE_ENTRY(jint, Unsafe_GetLoadAverage0(JNIEnv *env, jobject unsafe, jdoubleArray loadavg, jint nelem)) {
1143 const int max_nelem = 3;
1144 double la[max_nelem];
1145 jint ret;
1146
1147 typeArrayOop a = typeArrayOop(JNIHandles::resolve_non_null(loadavg));
1148 assert(a->is_typeArray(), "must be type array");
1149
1150 ret = os::loadavg(la, nelem);
1151 if (ret == -1) {
1152 return -1;
1153 }
1154
1155 // if successful, ret is the number of samples actually retrieved.
1156 assert(ret >= 0 && ret <= max_nelem, "Unexpected loadavg return value");
1157 switch(ret) {
1158 case 3: a->double_at_put(2, (jdouble)la[2]); // fall through
1159 case 2: a->double_at_put(1, (jdouble)la[1]); // fall through
1160 case 1: a->double_at_put(0, (jdouble)la[0]); break;
1161 }
1162
1163 return ret;
1164 } UNSAFE_END
1165
1166
1167 /// JVM_RegisterUnsafeMethods
1168
1169 #define ADR "J"
1170
1171 #define LANG "Ljava/lang/"
1172
1173 #define OBJ LANG "Object;"
1174 #define CLS LANG "Class;"
1175 #define FLD LANG "reflect/Field;"
1176 #define THR LANG "Throwable;"
1177
1178 #define DC_Args LANG "String;[BII" LANG "ClassLoader;" "Ljava/security/ProtectionDomain;"
1179 #define DAC_Args CLS "[B[" OBJ
1180
1181 #define CC (char*) /*cast a literal from (const char*)*/
1182 #define FN_PTR(f) CAST_FROM_FN_PTR(void*, &f)
1183
1184 #define DECLARE_GETPUTOOP(Type, Desc) \
1185 {CC "get" #Type, CC "(" OBJ "J)" #Desc, FN_PTR(Unsafe_Get##Type)}, \
1186 {CC "put" #Type, CC "(" OBJ "J" #Desc ")V", FN_PTR(Unsafe_Put##Type)}, \
1187 {CC "get" #Type "Volatile", CC "(" OBJ "J)" #Desc, FN_PTR(Unsafe_Get##Type##Volatile)}, \
1188 {CC "put" #Type "Volatile", CC "(" OBJ "J" #Desc ")V", FN_PTR(Unsafe_Put##Type##Volatile)}
1189
1190
1191 static JNINativeMethod jdk_internal_misc_Unsafe_methods[] = {
1192 {CC "getObject", CC "(" OBJ "J)" OBJ "", FN_PTR(Unsafe_GetObject)},
1193 {CC "putObject", CC "(" OBJ "J" OBJ ")V", FN_PTR(Unsafe_PutObject)},
1194 {CC "getObjectVolatile",CC "(" OBJ "J)" OBJ "", FN_PTR(Unsafe_GetObjectVolatile)},
1195 {CC "putObjectVolatile",CC "(" OBJ "J" OBJ ")V", FN_PTR(Unsafe_PutObjectVolatile)},
1196
1197 {CC "getUncompressedObject", CC "(" ADR ")" OBJ, FN_PTR(Unsafe_GetUncompressedObject)},
1198
1199 DECLARE_GETPUTOOP(Boolean, Z),
1200 DECLARE_GETPUTOOP(Byte, B),
1201 DECLARE_GETPUTOOP(Short, S),
1202 DECLARE_GETPUTOOP(Char, C),
1203 DECLARE_GETPUTOOP(Int, I),
1204 DECLARE_GETPUTOOP(Long, J),
1205 DECLARE_GETPUTOOP(Float, F),
1206 DECLARE_GETPUTOOP(Double, D),
1207
1208 {CC "allocateMemory0", CC "(J)" ADR, FN_PTR(Unsafe_AllocateMemory0)},
1209 {CC "reallocateMemory0", CC "(" ADR "J)" ADR, FN_PTR(Unsafe_ReallocateMemory0)},
1210 {CC "freeMemory0", CC "(" ADR ")V", FN_PTR(Unsafe_FreeMemory0)},
1211
1212 {CC "objectFieldOffset0", CC "(" FLD ")J", FN_PTR(Unsafe_ObjectFieldOffset0)},
1213 {CC "objectFieldOffset1", CC "(" CLS LANG "String;)J", FN_PTR(Unsafe_ObjectFieldOffset1)},
1214 {CC "staticFieldOffset0", CC "(" FLD ")J", FN_PTR(Unsafe_StaticFieldOffset0)},
1215 {CC "staticFieldBase0", CC "(" FLD ")" OBJ, FN_PTR(Unsafe_StaticFieldBase0)},
1216 {CC "ensureClassInitialized0", CC "(" CLS ")V", FN_PTR(Unsafe_EnsureClassInitialized0)},
1217 {CC "arrayBaseOffset0", CC "(" CLS ")I", FN_PTR(Unsafe_ArrayBaseOffset0)},
1218 {CC "arrayIndexScale0", CC "(" CLS ")I", FN_PTR(Unsafe_ArrayIndexScale0)},
1219 {CC "addressSize0", CC "()I", FN_PTR(Unsafe_AddressSize0)},
1220 {CC "pageSize", CC "()I", FN_PTR(Unsafe_PageSize)},
1221
1222 {CC "defineClass0", CC "(" DC_Args ")" CLS, FN_PTR(Unsafe_DefineClass0)},
1223 {CC "allocateInstance", CC "(" CLS ")" OBJ, FN_PTR(Unsafe_AllocateInstance)},
1224 {CC "throwException", CC "(" THR ")V", FN_PTR(Unsafe_ThrowException)},
1225 {CC "compareAndSetObject",CC "(" OBJ "J" OBJ "" OBJ ")Z", FN_PTR(Unsafe_CompareAndSetObject)},
1226 {CC "compareAndSetInt", CC "(" OBJ "J""I""I"")Z", FN_PTR(Unsafe_CompareAndSetInt)},
1227 {CC "compareAndSetLong", CC "(" OBJ "J""J""J"")Z", FN_PTR(Unsafe_CompareAndSetLong)},
1228 {CC "compareAndExchangeObject", CC "(" OBJ "J" OBJ "" OBJ ")" OBJ, FN_PTR(Unsafe_CompareAndExchangeObject)},
1229 {CC "compareAndExchangeInt", CC "(" OBJ "J""I""I"")I", FN_PTR(Unsafe_CompareAndExchangeInt)},
1230 {CC "compareAndExchangeLong", CC "(" OBJ "J""J""J"")J", FN_PTR(Unsafe_CompareAndExchangeLong)},
1231
1232 {CC "park", CC "(ZJ)V", FN_PTR(Unsafe_Park)},
1233 {CC "unpark", CC "(" OBJ ")V", FN_PTR(Unsafe_Unpark)},
1234
1235 {CC "getLoadAverage0", CC "([DI)I", FN_PTR(Unsafe_GetLoadAverage0)},
1236
1237 {CC "copyMemory0", CC "(" OBJ "J" OBJ "JJ)V", FN_PTR(Unsafe_CopyMemory0)},
1238 {CC "copySwapMemory0", CC "(" OBJ "J" OBJ "JJJ)V", FN_PTR(Unsafe_CopySwapMemory0)},
1239 {CC "setMemory0", CC "(" OBJ "JJB)V", FN_PTR(Unsafe_SetMemory0)},
1240
1241 {CC "defineAnonymousClass0", CC "(" DAC_Args ")" CLS, FN_PTR(Unsafe_DefineAnonymousClass0)},
1242
1243 {CC "shouldBeInitialized0", CC "(" CLS ")Z", FN_PTR(Unsafe_ShouldBeInitialized0)},
1244
1245 {CC "loadFence", CC "()V", FN_PTR(Unsafe_LoadFence)},
1246 {CC "storeFence", CC "()V", FN_PTR(Unsafe_StoreFence)},
1247 {CC "fullFence", CC "()V", FN_PTR(Unsafe_FullFence)},
1248
1249 {CC "isBigEndian0", CC "()Z", FN_PTR(Unsafe_isBigEndian0)},
1250 {CC "unalignedAccess0", CC "()Z", FN_PTR(Unsafe_unalignedAccess0)}
1251 };
1252
1253 #undef CC
1254 #undef FN_PTR
1255
1256 #undef ADR
1257 #undef LANG
1258 #undef OBJ
1259 #undef CLS
1260 #undef FLD
1261 #undef THR
1262 #undef DC_Args
1263 #undef DAC_Args
1264
1265 #undef DECLARE_GETPUTOOP
1266
1267
1268 // This function is exported, used by NativeLookup.
1269 // The Unsafe_xxx functions above are called only from the interpreter.
1270 // The optimizer looks at names and signatures to recognize
1271 // individual functions.
1272
1273 JVM_ENTRY(void, JVM_RegisterJDKInternalMiscUnsafeMethods(JNIEnv *env, jclass unsafeclass)) {
1274 ThreadToNativeFromVM ttnfv(thread);
1275
1276 int ok = env->RegisterNatives(unsafeclass, jdk_internal_misc_Unsafe_methods, sizeof(jdk_internal_misc_Unsafe_methods)/sizeof(JNINativeMethod));
1277 guarantee(ok == 0, "register jdk.internal.misc.Unsafe natives");
1278 } JVM_END