1 /*
2 * Copyright (c) 2000, 2023, 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/classLoader.hpp"
28 #include "classfile/classLoadInfo.hpp"
29 #include "classfile/javaClasses.inline.hpp"
30 #include "classfile/systemDictionary.hpp"
31 #include "classfile/vmSymbols.hpp"
32 #include "jfr/jfrEvents.hpp"
33 #include "jni.h"
34 #include "jvm.h"
35 #include "memory/allocation.inline.hpp"
36 #include "memory/resourceArea.hpp"
37 #include "logging/log.hpp"
38 #include "logging/logStream.hpp"
39 #include "oops/access.inline.hpp"
40 #include "oops/fieldStreams.inline.hpp"
41 #include "oops/flatArrayKlass.hpp"
42 #include "oops/flatArrayOop.inline.hpp"
43 #include "oops/inlineKlass.inline.hpp"
44 #include "oops/instanceKlass.inline.hpp"
45 #include "oops/klass.inline.hpp"
46 #include "oops/objArrayOop.inline.hpp"
47 #include "oops/oop.inline.hpp"
48 #include "oops/typeArrayOop.inline.hpp"
49 #include "prims/jvmtiExport.hpp"
50 #include "prims/unsafe.hpp"
51 #include "runtime/fieldDescriptor.inline.hpp"
52 #include "runtime/globals.hpp"
53 #include "runtime/handles.inline.hpp"
54 #include "runtime/interfaceSupport.inline.hpp"
55 #include "runtime/javaThread.inline.hpp"
56 #include "runtime/jniHandles.inline.hpp"
57 #include "runtime/orderAccess.hpp"
58 #include "runtime/reflection.hpp"
59 #include "runtime/sharedRuntime.hpp"
60 #include "runtime/stubRoutines.hpp"
61 #include "runtime/threadSMR.hpp"
62 #include "runtime/vmOperations.hpp"
63 #include "runtime/vm_version.hpp"
64 #include "services/threadService.hpp"
65 #include "utilities/align.hpp"
66 #include "utilities/copy.hpp"
67 #include "utilities/dtrace.hpp"
68 #include "utilities/macros.hpp"
69
70 /**
71 * Implementation of the jdk.internal.misc.Unsafe class
72 */
73
74
75 #define MAX_OBJECT_SIZE \
76 ( arrayOopDesc::header_size(T_DOUBLE) * HeapWordSize \
77 + ((julong)max_jint * sizeof(double)) )
78
79
80 #define UNSAFE_ENTRY(result_type, header) \
81 JVM_ENTRY(static result_type, header)
82
83 #define UNSAFE_LEAF(result_type, header) \
84 JVM_LEAF(static result_type, header)
85
86 #define UNSAFE_END JVM_END
87
88
89 static inline void* addr_from_java(jlong addr) {
90 // This assert fails in a variety of ways on 32-bit systems.
91 // It is impossible to predict whether native code that converts
92 // pointers to longs will sign-extend or zero-extend the addresses.
93 //assert(addr == (uintptr_t)addr, "must not be odd high bits");
94 return (void*)(uintptr_t)addr;
95 }
96
97 static inline jlong addr_to_java(void* p) {
98 assert(p == (void*)(uintptr_t)p, "must not be odd high bits");
99 return (uintptr_t)p;
100 }
101
102
103 // Note: The VM's obj_field and related accessors use byte-scaled
104 // ("unscaled") offsets, just as the unsafe methods do.
105
106 // However, the method Unsafe.fieldOffset explicitly declines to
107 // guarantee this. The field offset values manipulated by the Java user
108 // through the Unsafe API are opaque cookies that just happen to be byte
109 // offsets. We represent this state of affairs by passing the cookies
110 // through conversion functions when going between the VM and the Unsafe API.
111 // The conversion functions just happen to be no-ops at present.
112
113 static inline jlong field_offset_to_byte_offset(jlong field_offset) {
114 return field_offset;
115 }
116
117 static inline jlong field_offset_from_byte_offset(jlong byte_offset) {
118 return byte_offset;
119 }
120
121 static inline void assert_field_offset_sane(oop p, jlong field_offset) {
122 #ifdef ASSERT
123 jlong byte_offset = field_offset_to_byte_offset(field_offset);
124
125 if (p != nullptr) {
126 assert(byte_offset >= 0 && byte_offset <= (jlong)MAX_OBJECT_SIZE, "sane offset");
127 if (byte_offset == (jint)byte_offset) {
128 void* ptr_plus_disp = cast_from_oop<address>(p) + byte_offset;
129 assert(p->field_addr<void>((jint)byte_offset) == ptr_plus_disp,
130 "raw [ptr+disp] must be consistent with oop::field_addr");
131 }
132 jlong p_size = HeapWordSize * (jlong)(p->size());
133 assert(byte_offset < p_size, "Unsafe access: offset " INT64_FORMAT " > object's size " INT64_FORMAT, (int64_t)byte_offset, (int64_t)p_size);
134 }
135 #endif
136 }
137
138 static inline void* index_oop_from_field_offset_long(oop p, jlong field_offset) {
139 assert_field_offset_sane(p, field_offset);
140 jlong byte_offset = field_offset_to_byte_offset(field_offset);
141
142 if (sizeof(char*) == sizeof(jint)) { // (this constant folds!)
143 return cast_from_oop<address>(p) + (jint) byte_offset;
144 } else {
145 return cast_from_oop<address>(p) + byte_offset;
146 }
147 }
148
149 // Externally callable versions:
150 // (Use these in compiler intrinsics which emulate unsafe primitives.)
151 jlong Unsafe_field_offset_to_byte_offset(jlong field_offset) {
152 return field_offset;
153 }
154 jlong Unsafe_field_offset_from_byte_offset(jlong byte_offset) {
155 return byte_offset;
156 }
157
158 ///// Data read/writes on the Java heap and in native (off-heap) memory
159
160 /**
161 * Helper class to wrap memory accesses in JavaThread::doing_unsafe_access()
162 */
163 class GuardUnsafeAccess {
164 JavaThread* _thread;
165
166 public:
167 GuardUnsafeAccess(JavaThread* thread) : _thread(thread) {
168 // native/off-heap access which may raise SIGBUS if accessing
169 // memory mapped file data in a region of the file which has
170 // been truncated and is now invalid.
171 _thread->set_doing_unsafe_access(true);
172 }
173
174 ~GuardUnsafeAccess() {
175 _thread->set_doing_unsafe_access(false);
176 }
177 };
178
179 /**
180 * Helper class for accessing memory.
181 *
182 * Normalizes values and wraps accesses in
183 * JavaThread::doing_unsafe_access() if needed.
184 */
185 template <typename T>
186 class MemoryAccess : StackObj {
187 JavaThread* _thread;
188 oop _obj;
189 ptrdiff_t _offset;
190
191 // Resolves and returns the address of the memory access.
192 // This raw memory access may fault, so we make sure it happens within the
193 // guarded scope by making the access volatile at least. Since the store
194 // of Thread::set_doing_unsafe_access() is also volatile, these accesses
195 // can not be reordered by the compiler. Therefore, if the access triggers
196 // a fault, we will know that Thread::doing_unsafe_access() returns true.
197 volatile T* addr() {
198 void* addr = index_oop_from_field_offset_long(_obj, _offset);
199 return static_cast<volatile T*>(addr);
200 }
201
202 template <typename U>
203 U normalize_for_write(U x) {
204 return x;
205 }
206
207 jboolean normalize_for_write(jboolean x) {
208 return x & 1;
209 }
210
211 template <typename U>
212 U normalize_for_read(U x) {
213 return x;
214 }
215
216 jboolean normalize_for_read(jboolean x) {
217 return x != 0;
218 }
219
220 public:
221 MemoryAccess(JavaThread* thread, jobject obj, jlong offset)
222 : _thread(thread), _obj(JNIHandles::resolve(obj)), _offset((ptrdiff_t)offset) {
223 assert_field_offset_sane(_obj, offset);
224 }
225
226 T get() {
227 GuardUnsafeAccess guard(_thread);
228 return normalize_for_read(*addr());
229 }
230
231 void put(T x) {
232 GuardUnsafeAccess guard(_thread);
233 assert(_obj == NULL || !_obj->is_inline_type() || _obj->mark().is_larval_state(), "must be an object instance or a larval inline type");
234 *addr() = normalize_for_write(x);
235 }
236
237 T get_volatile() {
238 GuardUnsafeAccess guard(_thread);
239 volatile T ret = RawAccess<MO_SEQ_CST>::load(addr());
240 return normalize_for_read(ret);
241 }
242
243 void put_volatile(T x) {
244 GuardUnsafeAccess guard(_thread);
245 RawAccess<MO_SEQ_CST>::store(addr(), normalize_for_write(x));
246 }
247 };
248
249 #ifdef ASSERT
250 /*
251 * Get the field descriptor of the field of the given object at the given offset.
252 */
253 static bool get_field_descriptor(oop p, jlong offset, fieldDescriptor* fd) {
254 bool found = false;
255 Klass* k = p->klass();
256 if (k->is_instance_klass()) {
257 InstanceKlass* ik = InstanceKlass::cast(k);
258 found = ik->find_field_from_offset((int)offset, false, fd);
259 if (!found && ik->is_mirror_instance_klass()) {
260 Klass* k2 = java_lang_Class::as_Klass(p);
261 if (k2->is_instance_klass()) {
262 ik = InstanceKlass::cast(k2);
263 found = ik->find_field_from_offset((int)offset, true, fd);
264 }
265 }
266 }
267 return found;
268 }
269 #endif // ASSERT
270
271 static void assert_and_log_unsafe_value_access(oop p, jlong offset, InlineKlass* vk) {
272 Klass* k = p->klass();
273 #ifdef ASSERT
274 if (k->is_instance_klass()) {
275 assert_field_offset_sane(p, offset);
276 fieldDescriptor fd;
277 bool found = get_field_descriptor(p, offset, &fd);
278 if (found) {
279 assert(found, "value field not found");
280 assert(fd.is_inlined(), "field not flat");
281 } else {
282 if (log_is_enabled(Trace, valuetypes)) {
283 log_trace(valuetypes)("not a field in %s at offset " UINT64_FORMAT_X,
284 p->klass()->external_name(), (uint64_t)offset);
285 }
286 }
287 } else if (k->is_flatArray_klass()) {
288 FlatArrayKlass* vak = FlatArrayKlass::cast(k);
289 int index = (offset - vak->array_header_in_bytes()) / vak->element_byte_size();
290 address dest = (address)((flatArrayOop)p)->value_at_addr(index, vak->layout_helper());
291 assert(dest == (cast_from_oop<address>(p) + offset), "invalid offset");
292 } else {
293 ShouldNotReachHere();
294 }
295 #endif // ASSERT
296 if (log_is_enabled(Trace, valuetypes)) {
297 if (k->is_flatArray_klass()) {
298 FlatArrayKlass* vak = FlatArrayKlass::cast(k);
299 int index = (offset - vak->array_header_in_bytes()) / vak->element_byte_size();
300 address dest = (address)((flatArrayOop)p)->value_at_addr(index, vak->layout_helper());
301 log_trace(valuetypes)("%s array type %s index %d element size %d offset " UINT64_FORMAT_X " at " INTPTR_FORMAT,
302 p->klass()->external_name(), vak->external_name(),
303 index, vak->element_byte_size(), (uint64_t)offset, p2i(dest));
304 } else {
305 log_trace(valuetypes)("%s field type %s at offset " UINT64_FORMAT_X,
306 p->klass()->external_name(), vk->external_name(), (uint64_t)offset);
307 }
308 }
309 }
310
311 // These functions allow a null base pointer with an arbitrary address.
312 // But if the base pointer is non-null, the offset should make some sense.
313 // That is, it should be in the range [0, MAX_OBJECT_SIZE].
314 UNSAFE_ENTRY(jobject, Unsafe_GetReference(JNIEnv *env, jobject unsafe, jobject obj, jlong offset)) {
315 oop p = JNIHandles::resolve(obj);
316 assert_field_offset_sane(p, offset);
317 oop v = HeapAccess<ON_UNKNOWN_OOP_REF>::oop_load_at(p, offset);
318 return JNIHandles::make_local(THREAD, v);
319 } UNSAFE_END
320
321 UNSAFE_ENTRY(void, Unsafe_PutReference(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jobject x_h)) {
322 oop x = JNIHandles::resolve(x_h);
323 oop p = JNIHandles::resolve(obj);
324 assert_field_offset_sane(p, offset);
325 assert(!p->is_inline_type() || p->mark().is_larval_state(), "must be an object instance or a larval inline type");
326 HeapAccess<ON_UNKNOWN_OOP_REF>::oop_store_at(p, offset, x);
327 } UNSAFE_END
328
329 UNSAFE_ENTRY(jlong, Unsafe_ValueHeaderSize(JNIEnv *env, jobject unsafe, jclass c)) {
330 Klass* k = java_lang_Class::as_Klass(JNIHandles::resolve_non_null(c));
331 InlineKlass* vk = InlineKlass::cast(k);
332 return vk->first_field_offset();
333 } UNSAFE_END
334
335 UNSAFE_ENTRY(jboolean, Unsafe_IsFlattenedField(JNIEnv *env, jobject unsafe, jobject o)) {
336 oop f = JNIHandles::resolve_non_null(o);
337 Klass* k = java_lang_Class::as_Klass(java_lang_reflect_Field::clazz(f));
338 int slot = java_lang_reflect_Field::slot(f);
339 return InstanceKlass::cast(k)->field_is_inlined(slot);
340 } UNSAFE_END
341
342 UNSAFE_ENTRY(jboolean, Unsafe_IsFlattenedArray(JNIEnv *env, jobject unsafe, jclass c)) {
343 Klass* k = java_lang_Class::as_Klass(JNIHandles::resolve_non_null(c));
344 return k->is_flatArray_klass();
345 } UNSAFE_END
346
347 UNSAFE_ENTRY(jobject, Unsafe_UninitializedDefaultValue(JNIEnv *env, jobject unsafe, jclass vc)) {
348 Klass* k = java_lang_Class::as_Klass(JNIHandles::resolve_non_null(vc));
349 InlineKlass* vk = InlineKlass::cast(k);
350 oop v = vk->default_value();
351 return JNIHandles::make_local(THREAD, v);
352 } UNSAFE_END
353
354 UNSAFE_ENTRY(jobject, Unsafe_GetValue(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jclass vc)) {
355 oop base = JNIHandles::resolve(obj);
356 Klass* k = java_lang_Class::as_Klass(JNIHandles::resolve_non_null(vc));
357 InlineKlass* vk = InlineKlass::cast(k);
358 assert_and_log_unsafe_value_access(base, offset, vk);
359 Handle base_h(THREAD, base);
360 oop v = vk->read_inlined_field(base_h(), offset, CHECK_NULL);
361 return JNIHandles::make_local(THREAD, v);
362 } UNSAFE_END
363
364 UNSAFE_ENTRY(void, Unsafe_PutValue(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jclass vc, jobject value)) {
365 oop base = JNIHandles::resolve(obj);
366 Klass* k = java_lang_Class::as_Klass(JNIHandles::resolve_non_null(vc));
367 InlineKlass* vk = InlineKlass::cast(k);
368 assert(!base->is_inline_type() || base->mark().is_larval_state(), "must be an object instance or a larval inline type");
369 assert_and_log_unsafe_value_access(base, offset, vk);
370 oop v = JNIHandles::resolve(value);
371 vk->write_inlined_field(base, offset, v, CHECK);
372 } UNSAFE_END
373
374 UNSAFE_ENTRY(jobject, Unsafe_MakePrivateBuffer(JNIEnv *env, jobject unsafe, jobject value)) {
375 oop v = JNIHandles::resolve_non_null(value);
376 assert(v->is_inline_type(), "must be an inline type instance");
377 Handle vh(THREAD, v);
378 InlineKlass* vk = InlineKlass::cast(v->klass());
379 instanceOop new_value = vk->allocate_instance_buffer(CHECK_NULL);
380 vk->inline_copy_oop_to_new_oop(vh(), new_value);
381 markWord mark = new_value->mark();
382 new_value->set_mark(mark.enter_larval_state());
383 return JNIHandles::make_local(THREAD, new_value);
384 } UNSAFE_END
385
386 UNSAFE_ENTRY(jobject, Unsafe_FinishPrivateBuffer(JNIEnv *env, jobject unsafe, jobject value)) {
387 oop v = JNIHandles::resolve(value);
388 assert(v->mark().is_larval_state(), "must be a larval value");
389 markWord mark = v->mark();
390 v->set_mark(mark.exit_larval_state());
391 return JNIHandles::make_local(THREAD, v);
392 } UNSAFE_END
393
394 UNSAFE_ENTRY(jobject, Unsafe_GetReferenceVolatile(JNIEnv *env, jobject unsafe, jobject obj, jlong offset)) {
395 oop p = JNIHandles::resolve(obj);
396 assert_field_offset_sane(p, offset);
397 oop v = HeapAccess<MO_SEQ_CST | ON_UNKNOWN_OOP_REF>::oop_load_at(p, offset);
398 return JNIHandles::make_local(THREAD, v);
399 } UNSAFE_END
400
401 UNSAFE_ENTRY(void, Unsafe_PutReferenceVolatile(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jobject x_h)) {
402 oop x = JNIHandles::resolve(x_h);
403 oop p = JNIHandles::resolve(obj);
404 assert_field_offset_sane(p, offset);
405 HeapAccess<MO_SEQ_CST | ON_UNKNOWN_OOP_REF>::oop_store_at(p, offset, x);
406 } UNSAFE_END
407
408 UNSAFE_ENTRY(jobject, Unsafe_GetUncompressedObject(JNIEnv *env, jobject unsafe, jlong addr)) {
409 oop v = *(oop*) (address) addr;
410 return JNIHandles::make_local(THREAD, v);
411 } UNSAFE_END
412
413 #define DEFINE_GETSETOOP(java_type, Type) \
414 \
415 UNSAFE_ENTRY(java_type, Unsafe_Get##Type(JNIEnv *env, jobject unsafe, jobject obj, jlong offset)) { \
416 return MemoryAccess<java_type>(thread, obj, offset).get(); \
417 } UNSAFE_END \
418 \
419 UNSAFE_ENTRY(void, Unsafe_Put##Type(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, java_type x)) { \
420 MemoryAccess<java_type>(thread, obj, offset).put(x); \
421 } UNSAFE_END \
422 \
423 // END DEFINE_GETSETOOP.
424
425 DEFINE_GETSETOOP(jboolean, Boolean)
426 DEFINE_GETSETOOP(jbyte, Byte)
427 DEFINE_GETSETOOP(jshort, Short);
428 DEFINE_GETSETOOP(jchar, Char);
429 DEFINE_GETSETOOP(jint, Int);
430 DEFINE_GETSETOOP(jlong, Long);
431 DEFINE_GETSETOOP(jfloat, Float);
432 DEFINE_GETSETOOP(jdouble, Double);
433
434 #undef DEFINE_GETSETOOP
435
436 #define DEFINE_GETSETOOP_VOLATILE(java_type, Type) \
437 \
438 UNSAFE_ENTRY(java_type, Unsafe_Get##Type##Volatile(JNIEnv *env, jobject unsafe, jobject obj, jlong offset)) { \
439 return MemoryAccess<java_type>(thread, obj, offset).get_volatile(); \
440 } UNSAFE_END \
441 \
442 UNSAFE_ENTRY(void, Unsafe_Put##Type##Volatile(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, java_type x)) { \
443 MemoryAccess<java_type>(thread, obj, offset).put_volatile(x); \
444 } UNSAFE_END \
445 \
446 // END DEFINE_GETSETOOP_VOLATILE.
447
448 DEFINE_GETSETOOP_VOLATILE(jboolean, Boolean)
449 DEFINE_GETSETOOP_VOLATILE(jbyte, Byte)
450 DEFINE_GETSETOOP_VOLATILE(jshort, Short);
451 DEFINE_GETSETOOP_VOLATILE(jchar, Char);
452 DEFINE_GETSETOOP_VOLATILE(jint, Int);
453 DEFINE_GETSETOOP_VOLATILE(jlong, Long);
454 DEFINE_GETSETOOP_VOLATILE(jfloat, Float);
455 DEFINE_GETSETOOP_VOLATILE(jdouble, Double);
456
457 #undef DEFINE_GETSETOOP_VOLATILE
458
459 UNSAFE_LEAF(void, Unsafe_FullFence(JNIEnv *env, jobject unsafe)) {
460 OrderAccess::fence();
461 } UNSAFE_END
462
463 ////// Allocation requests
464
465 UNSAFE_ENTRY(jobject, Unsafe_AllocateInstance(JNIEnv *env, jobject unsafe, jclass cls)) {
466 JvmtiVMObjectAllocEventCollector oam;
467 instanceOop i = InstanceKlass::allocate_instance(JNIHandles::resolve_non_null(cls), CHECK_NULL);
468 return JNIHandles::make_local(THREAD, i);
469 } UNSAFE_END
470
471 UNSAFE_ENTRY(jlong, Unsafe_AllocateMemory0(JNIEnv *env, jobject unsafe, jlong size)) {
472 size_t sz = (size_t)size;
473
474 assert(is_aligned(sz, HeapWordSize), "sz not aligned");
475
476 void* x = os::malloc(sz, mtOther);
477
478 return addr_to_java(x);
479 } UNSAFE_END
480
481 UNSAFE_ENTRY(jlong, Unsafe_ReallocateMemory0(JNIEnv *env, jobject unsafe, jlong addr, jlong size)) {
482 void* p = addr_from_java(addr);
483 size_t sz = (size_t)size;
484
485 assert(is_aligned(sz, HeapWordSize), "sz not aligned");
486
487 void* x = os::realloc(p, sz, mtOther);
488
489 return addr_to_java(x);
490 } UNSAFE_END
491
492 UNSAFE_ENTRY(void, Unsafe_FreeMemory0(JNIEnv *env, jobject unsafe, jlong addr)) {
493 void* p = addr_from_java(addr);
494
495 os::free(p);
496 } UNSAFE_END
497
498 UNSAFE_ENTRY(void, Unsafe_SetMemory0(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jlong size, jbyte value)) {
499 size_t sz = (size_t)size;
500
501 oop base = JNIHandles::resolve(obj);
502 void* p = index_oop_from_field_offset_long(base, offset);
503
504 Copy::fill_to_memory_atomic(p, sz, value);
505 } UNSAFE_END
506
507 UNSAFE_ENTRY(void, Unsafe_CopyMemory0(JNIEnv *env, jobject unsafe, jobject srcObj, jlong srcOffset, jobject dstObj, jlong dstOffset, jlong size)) {
508 size_t sz = (size_t)size;
509
510 oop srcp = JNIHandles::resolve(srcObj);
511 oop dstp = JNIHandles::resolve(dstObj);
512
513 void* src = index_oop_from_field_offset_long(srcp, srcOffset);
514 void* dst = index_oop_from_field_offset_long(dstp, dstOffset);
515 {
516 GuardUnsafeAccess guard(thread);
517 if (StubRoutines::unsafe_arraycopy() != nullptr) {
518 MACOS_AARCH64_ONLY(ThreadWXEnable wx(WXExec, thread));
519 StubRoutines::UnsafeArrayCopy_stub()(src, dst, sz);
520 } else {
521 Copy::conjoint_memory_atomic(src, dst, sz);
522 }
523 }
524 } UNSAFE_END
525
526 // This function is a leaf since if the source and destination are both in native memory
527 // the copy may potentially be very large, and we don't want to disable GC if we can avoid it.
528 // If either source or destination (or both) are on the heap, the function will enter VM using
529 // JVM_ENTRY_FROM_LEAF
530 UNSAFE_LEAF(void, Unsafe_CopySwapMemory0(JNIEnv *env, jobject unsafe, jobject srcObj, jlong srcOffset, jobject dstObj, jlong dstOffset, jlong size, jlong elemSize)) {
531 size_t sz = (size_t)size;
532 size_t esz = (size_t)elemSize;
533
534 if (srcObj == nullptr && dstObj == nullptr) {
535 // Both src & dst are in native memory
536 address src = (address)srcOffset;
537 address dst = (address)dstOffset;
538
539 {
540 JavaThread* thread = JavaThread::thread_from_jni_environment(env);
541 GuardUnsafeAccess guard(thread);
542 Copy::conjoint_swap(src, dst, sz, esz);
543 }
544 } else {
545 // At least one of src/dst are on heap, transition to VM to access raw pointers
546
547 JVM_ENTRY_FROM_LEAF(env, void, Unsafe_CopySwapMemory0) {
548 oop srcp = JNIHandles::resolve(srcObj);
549 oop dstp = JNIHandles::resolve(dstObj);
550
551 address src = (address)index_oop_from_field_offset_long(srcp, srcOffset);
552 address dst = (address)index_oop_from_field_offset_long(dstp, dstOffset);
553
554 {
555 GuardUnsafeAccess guard(thread);
556 Copy::conjoint_swap(src, dst, sz, esz);
557 }
558 } JVM_END
559 }
560 } UNSAFE_END
561
562 UNSAFE_LEAF (void, Unsafe_WriteBack0(JNIEnv *env, jobject unsafe, jlong line)) {
563 assert(VM_Version::supports_data_cache_line_flush(), "should not get here");
564 #ifdef ASSERT
565 if (TraceMemoryWriteback) {
566 tty->print_cr("Unsafe: writeback 0x%p", addr_from_java(line));
567 }
568 #endif
569
570 MACOS_AARCH64_ONLY(ThreadWXEnable wx(WXExec, Thread::current()));
571 assert(StubRoutines::data_cache_writeback() != nullptr, "sanity");
572 (StubRoutines::DataCacheWriteback_stub())(addr_from_java(line));
573 } UNSAFE_END
574
575 static void doWriteBackSync0(bool is_pre)
576 {
577 MACOS_AARCH64_ONLY(ThreadWXEnable wx(WXExec, Thread::current()));
578 assert(StubRoutines::data_cache_writeback_sync() != nullptr, "sanity");
579 (StubRoutines::DataCacheWritebackSync_stub())(is_pre);
580 }
581
582 UNSAFE_LEAF (void, Unsafe_WriteBackPreSync0(JNIEnv *env, jobject unsafe)) {
583 assert(VM_Version::supports_data_cache_line_flush(), "should not get here");
584 #ifdef ASSERT
585 if (TraceMemoryWriteback) {
586 tty->print_cr("Unsafe: writeback pre-sync");
587 }
588 #endif
589
590 doWriteBackSync0(true);
591 } UNSAFE_END
592
593 UNSAFE_LEAF (void, Unsafe_WriteBackPostSync0(JNIEnv *env, jobject unsafe)) {
594 assert(VM_Version::supports_data_cache_line_flush(), "should not get here");
595 #ifdef ASSERT
596 if (TraceMemoryWriteback) {
597 tty->print_cr("Unsafe: writeback pre-sync");
598 }
599 #endif
600
601 doWriteBackSync0(false);
602 } UNSAFE_END
603
604 ////// Random queries
605
606 static jlong find_field_offset(jclass clazz, jstring name, TRAPS) {
607 assert(clazz != nullptr, "clazz must not be null");
608 assert(name != nullptr, "name must not be null");
609
610 ResourceMark rm(THREAD);
611 char *utf_name = java_lang_String::as_utf8_string(JNIHandles::resolve_non_null(name));
612
613 InstanceKlass* k = InstanceKlass::cast(java_lang_Class::as_Klass(JNIHandles::resolve_non_null(clazz)));
614
615 jint offset = -1;
616 for (JavaFieldStream fs(k); !fs.done(); fs.next()) {
617 Symbol *name = fs.name();
618 if (name->equals(utf_name)) {
619 offset = fs.offset();
620 break;
621 }
622 }
623 if (offset < 0) {
624 THROW_0(vmSymbols::java_lang_InternalError());
625 }
626 return field_offset_from_byte_offset(offset);
627 }
628
629 static jlong find_field_offset(jobject field, int must_be_static, TRAPS) {
630 assert(field != nullptr, "field must not be null");
631
632 oop reflected = JNIHandles::resolve_non_null(field);
633 oop mirror = java_lang_reflect_Field::clazz(reflected);
634 Klass* k = java_lang_Class::as_Klass(mirror);
635 int slot = java_lang_reflect_Field::slot(reflected);
636 int modifiers = java_lang_reflect_Field::modifiers(reflected);
637
638 if (must_be_static >= 0) {
639 int really_is_static = ((modifiers & JVM_ACC_STATIC) != 0);
640 if (must_be_static != really_is_static) {
641 THROW_0(vmSymbols::java_lang_IllegalArgumentException());
642 }
643 }
644
645 int offset = InstanceKlass::cast(k)->field_offset(slot);
646 return field_offset_from_byte_offset(offset);
647 }
648
649 UNSAFE_ENTRY(jlong, Unsafe_ObjectFieldOffset0(JNIEnv *env, jobject unsafe, jobject field)) {
650 return find_field_offset(field, 0, THREAD);
651 } UNSAFE_END
652
653 UNSAFE_ENTRY(jlong, Unsafe_ObjectFieldOffset1(JNIEnv *env, jobject unsafe, jclass c, jstring name)) {
654 return find_field_offset(c, name, THREAD);
655 } UNSAFE_END
656
657 UNSAFE_ENTRY(jlong, Unsafe_StaticFieldOffset0(JNIEnv *env, jobject unsafe, jobject field)) {
658 return find_field_offset(field, 1, THREAD);
659 } UNSAFE_END
660
661 UNSAFE_ENTRY(jobject, Unsafe_StaticFieldBase0(JNIEnv *env, jobject unsafe, jobject field)) {
662 assert(field != nullptr, "field must not be null");
663
664 // Note: In this VM implementation, a field address is always a short
665 // offset from the base of a klass metaobject. Thus, the full dynamic
666 // range of the return type is never used. However, some implementations
667 // might put the static field inside an array shared by many classes,
668 // or even at a fixed address, in which case the address could be quite
669 // large. In that last case, this function would return null, since
670 // the address would operate alone, without any base pointer.
671
672 oop reflected = JNIHandles::resolve_non_null(field);
673 oop mirror = java_lang_reflect_Field::clazz(reflected);
674 int modifiers = java_lang_reflect_Field::modifiers(reflected);
675
676 if ((modifiers & JVM_ACC_STATIC) == 0) {
677 THROW_0(vmSymbols::java_lang_IllegalArgumentException());
678 }
679
680 return JNIHandles::make_local(THREAD, mirror);
681 } UNSAFE_END
682
683 UNSAFE_ENTRY(void, Unsafe_EnsureClassInitialized0(JNIEnv *env, jobject unsafe, jobject clazz)) {
684 assert(clazz != nullptr, "clazz must not be null");
685
686 oop mirror = JNIHandles::resolve_non_null(clazz);
687
688 Klass* klass = java_lang_Class::as_Klass(mirror);
689 if (klass != nullptr && klass->should_be_initialized()) {
690 InstanceKlass* k = InstanceKlass::cast(klass);
691 k->initialize(CHECK);
692 }
693 }
694 UNSAFE_END
695
696 UNSAFE_ENTRY(jboolean, Unsafe_ShouldBeInitialized0(JNIEnv *env, jobject unsafe, jobject clazz)) {
697 assert(clazz != nullptr, "clazz must not be null");
698
699 oop mirror = JNIHandles::resolve_non_null(clazz);
700 Klass* klass = java_lang_Class::as_Klass(mirror);
701
702 if (klass != nullptr && klass->should_be_initialized()) {
703 return true;
704 }
705
706 return false;
707 }
708 UNSAFE_END
709
710 static void getBaseAndScale(int& base, int& scale, jclass clazz, TRAPS) {
711 assert(clazz != nullptr, "clazz must not be null");
712
713 oop mirror = JNIHandles::resolve_non_null(clazz);
714 Klass* k = java_lang_Class::as_Klass(mirror);
715
716 if (k == nullptr || !k->is_array_klass()) {
717 THROW(vmSymbols::java_lang_InvalidClassException());
718 } else if (k->is_objArray_klass()) {
719 base = arrayOopDesc::base_offset_in_bytes(T_OBJECT);
720 scale = heapOopSize;
721 } else if (k->is_typeArray_klass()) {
722 TypeArrayKlass* tak = TypeArrayKlass::cast(k);
723 base = tak->array_header_in_bytes();
724 assert(base == arrayOopDesc::base_offset_in_bytes(tak->element_type()), "array_header_size semantics ok");
725 scale = (1 << tak->log2_element_size());
726 } else if (k->is_flatArray_klass()) {
727 FlatArrayKlass* vak = FlatArrayKlass::cast(k);
728 InlineKlass* vklass = vak->element_klass();
729 base = vak->array_header_in_bytes();
730 scale = vak->element_byte_size();
731 } else {
732 ShouldNotReachHere();
733 }
734 }
735
736 UNSAFE_ENTRY(jint, Unsafe_ArrayBaseOffset0(JNIEnv *env, jobject unsafe, jclass clazz)) {
737 int base = 0, scale = 0;
738 getBaseAndScale(base, scale, clazz, CHECK_0);
739
740 return field_offset_from_byte_offset(base);
741 } UNSAFE_END
742
743
744 UNSAFE_ENTRY(jint, Unsafe_ArrayIndexScale0(JNIEnv *env, jobject unsafe, jclass clazz)) {
745 int base = 0, scale = 0;
746 getBaseAndScale(base, scale, clazz, CHECK_0);
747
748 // This VM packs both fields and array elements down to the byte.
749 // But watch out: If this changes, so that array references for
750 // a given primitive type (say, T_BOOLEAN) use different memory units
751 // than fields, this method MUST return zero for such arrays.
752 // For example, the VM used to store sub-word sized fields in full
753 // words in the object layout, so that accessors like getByte(Object,int)
754 // did not really do what one might expect for arrays. Therefore,
755 // this function used to report a zero scale factor, so that the user
756 // would know not to attempt to access sub-word array elements.
757 // // Code for unpacked fields:
758 // if (scale < wordSize) return 0;
759
760 // The following allows for a pretty general fieldOffset cookie scheme,
761 // but requires it to be linear in byte offset.
762 return field_offset_from_byte_offset(scale) - field_offset_from_byte_offset(0);
763 } UNSAFE_END
764
765
766 UNSAFE_ENTRY(jlong, Unsafe_GetObjectSize0(JNIEnv* env, jobject o, jobject obj))
767 oop p = JNIHandles::resolve(obj);
768 return p->size() * HeapWordSize;
769 UNSAFE_END
770
771
772 static inline void throw_new(JNIEnv *env, const char *ename) {
773 jclass cls = env->FindClass(ename);
774 if (env->ExceptionCheck()) {
775 env->ExceptionClear();
776 tty->print_cr("Unsafe: cannot throw %s because FindClass has failed", ename);
777 return;
778 }
779
780 env->ThrowNew(cls, nullptr);
781 }
782
783 static jclass Unsafe_DefineClass_impl(JNIEnv *env, jstring name, jbyteArray data, int offset, int length, jobject loader, jobject pd) {
784 // Code lifted from JDK 1.3 ClassLoader.c
785
786 jbyte *body;
787 char *utfName = nullptr;
788 jclass result = 0;
789 char buf[128];
790
791 assert(data != nullptr, "Class bytes must not be null");
792 assert(length >= 0, "length must not be negative: %d", length);
793
794 if (UsePerfData) {
795 ClassLoader::unsafe_defineClassCallCounter()->inc();
796 }
797
798 body = NEW_C_HEAP_ARRAY_RETURN_NULL(jbyte, length, mtInternal);
799 if (body == nullptr) {
800 throw_new(env, "java/lang/OutOfMemoryError");
801 return 0;
802 }
803
804 env->GetByteArrayRegion(data, offset, length, body);
805 if (env->ExceptionOccurred()) {
806 goto free_body;
807 }
808
809 if (name != nullptr) {
810 uint len = env->GetStringUTFLength(name);
811 int unicode_len = env->GetStringLength(name);
812
813 if (len >= sizeof(buf)) {
814 utfName = NEW_C_HEAP_ARRAY_RETURN_NULL(char, len + 1, mtInternal);
815 if (utfName == nullptr) {
816 throw_new(env, "java/lang/OutOfMemoryError");
817 goto free_body;
818 }
819 } else {
820 utfName = buf;
821 }
822
823 env->GetStringUTFRegion(name, 0, unicode_len, utfName);
824
825 for (uint i = 0; i < len; i++) {
826 if (utfName[i] == '.') utfName[i] = '/';
827 }
828 }
829
830 result = JVM_DefineClass(env, utfName, loader, body, length, pd);
831
832 if (utfName && utfName != buf) {
833 FREE_C_HEAP_ARRAY(char, utfName);
834 }
835
836 free_body:
837 FREE_C_HEAP_ARRAY(jbyte, body);
838 return result;
839 }
840
841
842 UNSAFE_ENTRY(jclass, Unsafe_DefineClass0(JNIEnv *env, jobject unsafe, jstring name, jbyteArray data, int offset, int length, jobject loader, jobject pd)) {
843 ThreadToNativeFromVM ttnfv(thread);
844
845 return Unsafe_DefineClass_impl(env, name, data, offset, length, loader, pd);
846 } UNSAFE_END
847
848
849 UNSAFE_ENTRY(void, Unsafe_ThrowException(JNIEnv *env, jobject unsafe, jthrowable thr)) {
850 ThreadToNativeFromVM ttnfv(thread);
851 env->Throw(thr);
852 } UNSAFE_END
853
854 // JSR166 ------------------------------------------------------------------
855
856 UNSAFE_ENTRY(jobject, Unsafe_CompareAndExchangeReference(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jobject e_h, jobject x_h)) {
857 oop x = JNIHandles::resolve(x_h);
858 oop e = JNIHandles::resolve(e_h);
859 oop p = JNIHandles::resolve(obj);
860 assert_field_offset_sane(p, offset);
861 oop res = HeapAccess<ON_UNKNOWN_OOP_REF>::oop_atomic_cmpxchg_at(p, (ptrdiff_t)offset, e, x);
862 return JNIHandles::make_local(THREAD, res);
863 } UNSAFE_END
864
865 UNSAFE_ENTRY(jint, Unsafe_CompareAndExchangeInt(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jint e, jint x)) {
866 oop p = JNIHandles::resolve(obj);
867 volatile jint* addr = (volatile jint*)index_oop_from_field_offset_long(p, offset);
868 return Atomic::cmpxchg(addr, e, x);
869 } UNSAFE_END
870
871 UNSAFE_ENTRY(jlong, Unsafe_CompareAndExchangeLong(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jlong e, jlong x)) {
872 oop p = JNIHandles::resolve(obj);
873 volatile jlong* addr = (volatile jlong*)index_oop_from_field_offset_long(p, offset);
874 return Atomic::cmpxchg(addr, e, x);
875 } UNSAFE_END
876
877 UNSAFE_ENTRY(jboolean, Unsafe_CompareAndSetReference(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jobject e_h, jobject x_h)) {
878 oop x = JNIHandles::resolve(x_h);
879 oop e = JNIHandles::resolve(e_h);
880 oop p = JNIHandles::resolve(obj);
881 assert_field_offset_sane(p, offset);
882 oop ret = HeapAccess<ON_UNKNOWN_OOP_REF>::oop_atomic_cmpxchg_at(p, (ptrdiff_t)offset, e, x);
883 return ret == e;
884 } UNSAFE_END
885
886 UNSAFE_ENTRY(jboolean, Unsafe_CompareAndSetInt(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jint e, jint x)) {
887 oop p = JNIHandles::resolve(obj);
888 volatile jint* addr = (volatile jint*)index_oop_from_field_offset_long(p, offset);
889 return Atomic::cmpxchg(addr, e, x) == e;
890 } UNSAFE_END
891
892 UNSAFE_ENTRY(jboolean, Unsafe_CompareAndSetLong(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jlong e, jlong x)) {
893 oop p = JNIHandles::resolve(obj);
894 volatile jlong* addr = (volatile jlong*)index_oop_from_field_offset_long(p, offset);
895 return Atomic::cmpxchg(addr, e, x) == e;
896 } UNSAFE_END
897
898 static void post_thread_park_event(EventThreadPark* event, const oop obj, jlong timeout_nanos, jlong until_epoch_millis) {
899 assert(event != nullptr, "invariant");
900 event->set_parkedClass((obj != nullptr) ? obj->klass() : nullptr);
901 event->set_timeout(timeout_nanos);
902 event->set_until(until_epoch_millis);
903 event->set_address((obj != nullptr) ? (u8)cast_from_oop<uintptr_t>(obj) : 0);
904 event->commit();
905 }
906
907 UNSAFE_ENTRY(void, Unsafe_Park(JNIEnv *env, jobject unsafe, jboolean isAbsolute, jlong time)) {
908 HOTSPOT_THREAD_PARK_BEGIN((uintptr_t) thread->parker(), (int) isAbsolute, time);
909 EventThreadPark event;
910
911 JavaThreadParkedState jtps(thread, time != 0);
912 thread->parker()->park(isAbsolute != 0, time);
913 if (event.should_commit()) {
914 const oop obj = thread->current_park_blocker();
915 if (time == 0) {
916 post_thread_park_event(&event, obj, min_jlong, min_jlong);
917 } else {
918 if (isAbsolute != 0) {
919 post_thread_park_event(&event, obj, min_jlong, time);
920 } else {
921 post_thread_park_event(&event, obj, time, min_jlong);
922 }
923 }
924 }
925 HOTSPOT_THREAD_PARK_END((uintptr_t) thread->parker());
926 } UNSAFE_END
927
928 UNSAFE_ENTRY(void, Unsafe_Unpark(JNIEnv *env, jobject unsafe, jobject jthread)) {
929 if (jthread != nullptr) {
930 oop thread_oop = JNIHandles::resolve_non_null(jthread);
931 // Get the JavaThread* stored in the java.lang.Thread object _before_
932 // the embedded ThreadsListHandle is constructed so we know if the
933 // early life stage of the JavaThread* is protected. We use acquire
934 // here to ensure that if we see a non-nullptr value, then we also
935 // see the main ThreadsList updates from the JavaThread* being added.
936 FastThreadsListHandle ftlh(thread_oop, java_lang_Thread::thread_acquire(thread_oop));
937 JavaThread* thr = ftlh.protected_java_thread();
938 if (thr != nullptr) {
939 // The still live JavaThread* is protected by the FastThreadsListHandle
940 // so it is safe to access.
941 Parker* p = thr->parker();
942 HOTSPOT_THREAD_UNPARK((uintptr_t) p);
943 p->unpark();
944 }
945 } // FastThreadsListHandle is destroyed here.
946 } UNSAFE_END
947
948 UNSAFE_ENTRY(jint, Unsafe_GetLoadAverage0(JNIEnv *env, jobject unsafe, jdoubleArray loadavg, jint nelem)) {
949 const int max_nelem = 3;
950 double la[max_nelem];
951 jint ret;
952
953 typeArrayOop a = typeArrayOop(JNIHandles::resolve_non_null(loadavg));
954 assert(a->is_typeArray(), "must be type array");
955
956 ret = os::loadavg(la, nelem);
957 if (ret == -1) {
958 return -1;
959 }
960
961 // if successful, ret is the number of samples actually retrieved.
962 assert(ret >= 0 && ret <= max_nelem, "Unexpected loadavg return value");
963 switch(ret) {
964 case 3: a->double_at_put(2, (jdouble)la[2]); // fall through
965 case 2: a->double_at_put(1, (jdouble)la[1]); // fall through
966 case 1: a->double_at_put(0, (jdouble)la[0]); break;
967 }
968
969 return ret;
970 } UNSAFE_END
971
972
973 /// JVM_RegisterUnsafeMethods
974
975 #define ADR "J"
976
977 #define LANG "Ljava/lang/"
978
979 #define OBJ LANG "Object;"
980 #define CLS LANG "Class;"
981 #define FLD LANG "reflect/Field;"
982 #define THR LANG "Throwable;"
983
984 #define DC_Args LANG "String;[BII" LANG "ClassLoader;" "Ljava/security/ProtectionDomain;"
985 #define DAC_Args CLS "[B[" OBJ
986
987 #define CC (char*) /*cast a literal from (const char*)*/
988 #define FN_PTR(f) CAST_FROM_FN_PTR(void*, &f)
989
990 #define DECLARE_GETPUTOOP(Type, Desc) \
991 {CC "get" #Type, CC "(" OBJ "J)" #Desc, FN_PTR(Unsafe_Get##Type)}, \
992 {CC "put" #Type, CC "(" OBJ "J" #Desc ")V", FN_PTR(Unsafe_Put##Type)}, \
993 {CC "get" #Type "Volatile", CC "(" OBJ "J)" #Desc, FN_PTR(Unsafe_Get##Type##Volatile)}, \
994 {CC "put" #Type "Volatile", CC "(" OBJ "J" #Desc ")V", FN_PTR(Unsafe_Put##Type##Volatile)}
995
996
997 static JNINativeMethod jdk_internal_misc_Unsafe_methods[] = {
998 {CC "getReference", CC "(" OBJ "J)" OBJ "", FN_PTR(Unsafe_GetReference)},
999 {CC "putReference", CC "(" OBJ "J" OBJ ")V", FN_PTR(Unsafe_PutReference)},
1000 {CC "getReferenceVolatile", CC "(" OBJ "J)" OBJ, FN_PTR(Unsafe_GetReferenceVolatile)},
1001 {CC "putReferenceVolatile", CC "(" OBJ "J" OBJ ")V", FN_PTR(Unsafe_PutReferenceVolatile)},
1002
1003 {CC "isFlattenedArray", CC "(" CLS ")Z", FN_PTR(Unsafe_IsFlattenedArray)},
1004 {CC "isFlattenedField0", CC "(" OBJ ")Z", FN_PTR(Unsafe_IsFlattenedField)},
1005 {CC "getValue", CC "(" OBJ "J" CLS ")" OBJ, FN_PTR(Unsafe_GetValue)},
1006 {CC "putValue", CC "(" OBJ "J" CLS OBJ ")V", FN_PTR(Unsafe_PutValue)},
1007 {CC "uninitializedDefaultValue", CC "(" CLS ")" OBJ, FN_PTR(Unsafe_UninitializedDefaultValue)},
1008 {CC "makePrivateBuffer", CC "(" OBJ ")" OBJ, FN_PTR(Unsafe_MakePrivateBuffer)},
1009 {CC "finishPrivateBuffer", CC "(" OBJ ")" OBJ, FN_PTR(Unsafe_FinishPrivateBuffer)},
1010 {CC "valueHeaderSize", CC "(" CLS ")J", FN_PTR(Unsafe_ValueHeaderSize)},
1011
1012 {CC "getUncompressedObject", CC "(" ADR ")" OBJ, FN_PTR(Unsafe_GetUncompressedObject)},
1013
1014 DECLARE_GETPUTOOP(Boolean, Z),
1015 DECLARE_GETPUTOOP(Byte, B),
1016 DECLARE_GETPUTOOP(Short, S),
1017 DECLARE_GETPUTOOP(Char, C),
1018 DECLARE_GETPUTOOP(Int, I),
1019 DECLARE_GETPUTOOP(Long, J),
1020 DECLARE_GETPUTOOP(Float, F),
1021 DECLARE_GETPUTOOP(Double, D),
1022
1023 {CC "allocateMemory0", CC "(J)" ADR, FN_PTR(Unsafe_AllocateMemory0)},
1024 {CC "reallocateMemory0", CC "(" ADR "J)" ADR, FN_PTR(Unsafe_ReallocateMemory0)},
1025 {CC "freeMemory0", CC "(" ADR ")V", FN_PTR(Unsafe_FreeMemory0)},
1026
1027 {CC "objectFieldOffset0", CC "(" FLD ")J", FN_PTR(Unsafe_ObjectFieldOffset0)},
1028 {CC "objectFieldOffset1", CC "(" CLS LANG "String;)J", FN_PTR(Unsafe_ObjectFieldOffset1)},
1029 {CC "staticFieldOffset0", CC "(" FLD ")J", FN_PTR(Unsafe_StaticFieldOffset0)},
1030 {CC "staticFieldBase0", CC "(" FLD ")" OBJ, FN_PTR(Unsafe_StaticFieldBase0)},
1031 {CC "ensureClassInitialized0", CC "(" CLS ")V", FN_PTR(Unsafe_EnsureClassInitialized0)},
1032 {CC "arrayBaseOffset0", CC "(" CLS ")I", FN_PTR(Unsafe_ArrayBaseOffset0)},
1033 {CC "arrayIndexScale0", CC "(" CLS ")I", FN_PTR(Unsafe_ArrayIndexScale0)},
1034 {CC "getObjectSize0", CC "(Ljava/lang/Object;)J", FN_PTR(Unsafe_GetObjectSize0)},
1035
1036 {CC "defineClass0", CC "(" DC_Args ")" CLS, FN_PTR(Unsafe_DefineClass0)},
1037 {CC "allocateInstance", CC "(" CLS ")" OBJ, FN_PTR(Unsafe_AllocateInstance)},
1038 {CC "throwException", CC "(" THR ")V", FN_PTR(Unsafe_ThrowException)},
1039 {CC "compareAndSetReference",CC "(" OBJ "J" OBJ "" OBJ ")Z", FN_PTR(Unsafe_CompareAndSetReference)},
1040 {CC "compareAndSetInt", CC "(" OBJ "J""I""I"")Z", FN_PTR(Unsafe_CompareAndSetInt)},
1041 {CC "compareAndSetLong", CC "(" OBJ "J""J""J"")Z", FN_PTR(Unsafe_CompareAndSetLong)},
1042 {CC "compareAndExchangeReference", CC "(" OBJ "J" OBJ "" OBJ ")" OBJ, FN_PTR(Unsafe_CompareAndExchangeReference)},
1043 {CC "compareAndExchangeInt", CC "(" OBJ "J""I""I"")I", FN_PTR(Unsafe_CompareAndExchangeInt)},
1044 {CC "compareAndExchangeLong", CC "(" OBJ "J""J""J"")J", FN_PTR(Unsafe_CompareAndExchangeLong)},
1045
1046 {CC "park", CC "(ZJ)V", FN_PTR(Unsafe_Park)},
1047 {CC "unpark", CC "(" OBJ ")V", FN_PTR(Unsafe_Unpark)},
1048
1049 {CC "getLoadAverage0", CC "([DI)I", FN_PTR(Unsafe_GetLoadAverage0)},
1050
1051 {CC "copyMemory0", CC "(" OBJ "J" OBJ "JJ)V", FN_PTR(Unsafe_CopyMemory0)},
1052 {CC "copySwapMemory0", CC "(" OBJ "J" OBJ "JJJ)V", FN_PTR(Unsafe_CopySwapMemory0)},
1053 {CC "writeback0", CC "(" "J" ")V", FN_PTR(Unsafe_WriteBack0)},
1054 {CC "writebackPreSync0", CC "()V", FN_PTR(Unsafe_WriteBackPreSync0)},
1055 {CC "writebackPostSync0", CC "()V", FN_PTR(Unsafe_WriteBackPostSync0)},
1056 {CC "setMemory0", CC "(" OBJ "JJB)V", FN_PTR(Unsafe_SetMemory0)},
1057
1058 {CC "shouldBeInitialized0", CC "(" CLS ")Z", FN_PTR(Unsafe_ShouldBeInitialized0)},
1059
1060 {CC "fullFence", CC "()V", FN_PTR(Unsafe_FullFence)},
1061 };
1062
1063 #undef CC
1064 #undef FN_PTR
1065
1066 #undef ADR
1067 #undef LANG
1068 #undef OBJ
1069 #undef CLS
1070 #undef FLD
1071 #undef THR
1072 #undef DC_Args
1073 #undef DAC_Args
1074
1075 #undef DECLARE_GETPUTOOP
1076
1077
1078 // This function is exported, used by NativeLookup.
1079 // The Unsafe_xxx functions above are called only from the interpreter.
1080 // The optimizer looks at names and signatures to recognize
1081 // individual functions.
1082
1083 JVM_ENTRY(void, JVM_RegisterJDKInternalMiscUnsafeMethods(JNIEnv *env, jclass unsafeclass)) {
1084 ThreadToNativeFromVM ttnfv(thread);
1085
1086 int ok = env->RegisterNatives(unsafeclass, jdk_internal_misc_Unsafe_methods, sizeof(jdk_internal_misc_Unsafe_methods)/sizeof(JNINativeMethod));
1087 guarantee(ok == 0, "register jdk.internal.misc.Unsafe natives");
1088 } JVM_END