1 /*
2 * Copyright (c) 2000, 2025, 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 "sanitizers/ub.hpp"
65 #include "services/threadService.hpp"
66 #include "utilities/align.hpp"
67 #include "utilities/copy.hpp"
68 #include "utilities/dtrace.hpp"
69 #include "utilities/macros.hpp"
70
71 /**
72 * Implementation of the jdk.internal.misc.Unsafe class
73 */
74
75
76 #define MAX_OBJECT_SIZE \
77 ( arrayOopDesc::base_offset_in_bytes(T_DOUBLE) \
78 + ((julong)max_jint * sizeof(double)) )
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 // All memory access methods (e.g. getInt, copyMemory) must use this macro.
87 // We call these methods "scoped" methods, as access to these methods is
88 // typically governed by a "scope" (a MemorySessionImpl object), and no
89 // access is allowed when the scope is no longer alive.
90 //
91 // Closing a scope object (cf. scopedMemoryAccess.cpp) can install
92 // an async exception during a safepoint. When that happens,
93 // scoped methods are not allowed to touch the underlying memory (as that
94 // memory might have been released). Therefore, when entering a scoped method
95 // we check if an async exception has been installed, and return immediately
96 // if that is the case.
97 //
98 // As a rule, we disallow safepoints in the middle of a scoped method.
99 // If an async exception handshake were installed in such a safepoint,
100 // memory access might still occur before the handshake is honored by
101 // the accessing thread.
102 //
103 // Corollary: as threads in native state are considered to be at a safepoint,
104 // scoped methods must NOT be executed while in the native thread state.
105 // Because of this, there can be no UNSAFE_LEAF_SCOPED.
106 #define UNSAFE_ENTRY_SCOPED(result_type, header) \
107 JVM_ENTRY(static result_type, header) \
108 if (thread->has_async_exception_condition()) {return (result_type)0;}
109
110 #define UNSAFE_END JVM_END
111
112
113 static inline void* addr_from_java(jlong addr) {
114 // This assert fails in a variety of ways on 32-bit systems.
115 // It is impossible to predict whether native code that converts
116 // pointers to longs will sign-extend or zero-extend the addresses.
117 //assert(addr == (uintptr_t)addr, "must not be odd high bits");
118 return (void*)(uintptr_t)addr;
119 }
120
121 static inline jlong addr_to_java(void* p) {
122 assert(p == (void*)(uintptr_t)p, "must not be odd high bits");
123 return (uintptr_t)p;
124 }
125
126
127 // Note: The VM's obj_field and related accessors use byte-scaled
128 // ("unscaled") offsets, just as the unsafe methods do.
129
130 // However, the method Unsafe.fieldOffset explicitly declines to
131 // guarantee this. The field offset values manipulated by the Java user
132 // through the Unsafe API are opaque cookies that just happen to be byte
133 // offsets. We represent this state of affairs by passing the cookies
134 // through conversion functions when going between the VM and the Unsafe API.
135 // The conversion functions just happen to be no-ops at present.
136
137 static inline jlong field_offset_to_byte_offset(jlong field_offset) {
138 return field_offset;
139 }
140
141 static inline int field_offset_from_byte_offset(int byte_offset) {
142 return byte_offset;
143 }
144
145 static inline void assert_field_offset_sane(oop p, jlong field_offset) {
146 #ifdef ASSERT
147 jlong byte_offset = field_offset_to_byte_offset(field_offset);
148
149 if (p != nullptr) {
150 assert(byte_offset >= 0 && byte_offset <= (jlong)MAX_OBJECT_SIZE, "sane offset");
151 if (byte_offset == (jint)byte_offset) {
152 void* ptr_plus_disp = cast_from_oop<address>(p) + byte_offset;
153 assert(p->field_addr<void>((jint)byte_offset) == ptr_plus_disp,
154 "raw [ptr+disp] must be consistent with oop::field_addr");
155 }
156 jlong p_size = HeapWordSize * (jlong)(p->size());
157 assert(byte_offset < p_size, "Unsafe access: offset " INT64_FORMAT " > object's size " INT64_FORMAT, (int64_t)byte_offset, (int64_t)p_size);
158 }
159 #endif
160 }
161
162 static inline void* index_oop_from_field_offset_long(oop p, jlong field_offset) {
163 assert_field_offset_sane(p, field_offset);
164 uintptr_t base_address = cast_from_oop<uintptr_t>(p);
165 uintptr_t byte_offset = (uintptr_t)field_offset_to_byte_offset(field_offset);
166 return (void*)(base_address + byte_offset);
167 }
168
169 // Externally callable versions:
170 // (Use these in compiler intrinsics which emulate unsafe primitives.)
171 jlong Unsafe_field_offset_to_byte_offset(jlong field_offset) {
172 return field_offset;
173 }
174 jlong Unsafe_field_offset_from_byte_offset(jlong byte_offset) {
175 return byte_offset;
176 }
177
178 ///// Data read/writes on the Java heap and in native (off-heap) memory
179
180 /**
181 * Helper class to wrap memory accesses in JavaThread::doing_unsafe_access()
182 */
183 class GuardUnsafeAccess {
184 JavaThread* _thread;
185
186 public:
187 GuardUnsafeAccess(JavaThread* thread) : _thread(thread) {
188 // native/off-heap access which may raise SIGBUS if accessing
189 // memory mapped file data in a region of the file which has
190 // been truncated and is now invalid.
191 _thread->set_doing_unsafe_access(true);
192 }
193
194 ~GuardUnsafeAccess() {
195 _thread->set_doing_unsafe_access(false);
196 }
197 };
198
199 /**
200 * Helper class for accessing memory.
201 *
202 * Normalizes values and wraps accesses in
203 * JavaThread::doing_unsafe_access() if needed.
204 */
205 template <typename T>
206 class MemoryAccess : StackObj {
207 JavaThread* _thread;
208 oop _obj;
209 ptrdiff_t _offset;
210
211 // Resolves and returns the address of the memory access.
212 // This raw memory access may fault, so we make sure it happens within the
213 // guarded scope by making the access volatile at least. Since the store
214 // of Thread::set_doing_unsafe_access() is also volatile, these accesses
215 // can not be reordered by the compiler. Therefore, if the access triggers
216 // a fault, we will know that Thread::doing_unsafe_access() returns true.
217 volatile T* addr() {
218 void* addr = index_oop_from_field_offset_long(_obj, _offset);
219 return static_cast<volatile T*>(addr);
220 }
221
222 template <typename U>
223 U normalize_for_write(U x) {
224 return x;
225 }
226
227 jboolean normalize_for_write(jboolean x) {
228 return x & 1;
229 }
230
231 template <typename U>
232 U normalize_for_read(U x) {
233 return x;
234 }
235
236 jboolean normalize_for_read(jboolean x) {
237 return x != 0;
238 }
239
240 public:
241 MemoryAccess(JavaThread* thread, jobject obj, jlong offset)
242 : _thread(thread), _obj(JNIHandles::resolve(obj)), _offset((ptrdiff_t)offset) {
243 assert_field_offset_sane(_obj, offset);
244 }
245
246 T get() {
247 GuardUnsafeAccess guard(_thread);
248 return normalize_for_read(*addr());
249 }
250
251 // we use this method at some places for writing to 0 e.g. to cause a crash;
252 // ubsan does not know that this is the desired behavior
253 ATTRIBUTE_NO_UBSAN
254 void put(T x) {
255 GuardUnsafeAccess guard(_thread);
256 assert(_obj == nullptr || !_obj->is_inline_type() || _obj->mark().is_larval_state(), "must be an object instance or a larval inline type");
257 *addr() = normalize_for_write(x);
258 }
259
260 T get_volatile() {
261 GuardUnsafeAccess guard(_thread);
262 volatile T ret = RawAccess<MO_SEQ_CST>::load(addr());
263 return normalize_for_read(ret);
264 }
265
266 void put_volatile(T x) {
267 GuardUnsafeAccess guard(_thread);
268 RawAccess<MO_SEQ_CST>::store(addr(), normalize_for_write(x));
269 }
270 };
271
272 #ifdef ASSERT
273 /*
274 * Get the field descriptor of the field of the given object at the given offset.
275 */
276 static bool get_field_descriptor(oop p, jlong offset, fieldDescriptor* fd) {
277 bool found = false;
278 Klass* k = p->klass();
279 if (k->is_instance_klass()) {
280 InstanceKlass* ik = InstanceKlass::cast(k);
281 found = ik->find_field_from_offset((int)offset, false, fd);
282 if (!found && ik->is_mirror_instance_klass()) {
283 Klass* k2 = java_lang_Class::as_Klass(p);
284 if (k2->is_instance_klass()) {
285 ik = InstanceKlass::cast(k2);
286 found = ik->find_field_from_offset((int)offset, true, fd);
287 }
288 }
289 }
290 return found;
291 }
292 #endif // ASSERT
293
294 static void assert_and_log_unsafe_value_access(oop p, jlong offset, InlineKlass* vk) {
295 Klass* k = p->klass();
296 #ifdef ASSERT
297 if (k->is_instance_klass()) {
298 assert_field_offset_sane(p, offset);
299 fieldDescriptor fd;
300 bool found = get_field_descriptor(p, offset, &fd);
301 if (found) {
302 assert(found, "value field not found");
303 assert(fd.is_flat(), "field not flat");
304 } else {
305 if (log_is_enabled(Trace, valuetypes)) {
306 log_trace(valuetypes)("not a field in %s at offset " UINT64_FORMAT_X,
307 p->klass()->external_name(), (uint64_t)offset);
308 }
309 }
310 } else if (k->is_flatArray_klass()) {
311 FlatArrayKlass* vak = FlatArrayKlass::cast(k);
312 int index = (offset - vak->array_header_in_bytes()) / vak->element_byte_size();
313 address dest = (address)((flatArrayOop)p)->value_at_addr(index, vak->layout_helper());
314 assert(dest == (cast_from_oop<address>(p) + offset), "invalid offset");
315 } else {
316 ShouldNotReachHere();
317 }
318 #endif // ASSERT
319 if (log_is_enabled(Trace, valuetypes)) {
320 if (k->is_flatArray_klass()) {
321 FlatArrayKlass* vak = FlatArrayKlass::cast(k);
322 int index = (offset - vak->array_header_in_bytes()) / vak->element_byte_size();
323 address dest = (address)((flatArrayOop)p)->value_at_addr(index, vak->layout_helper());
324 log_trace(valuetypes)("%s array type %s index %d element size %d offset " UINT64_FORMAT_X " at " INTPTR_FORMAT,
325 p->klass()->external_name(), vak->external_name(),
326 index, vak->element_byte_size(), (uint64_t)offset, p2i(dest));
327 } else {
328 log_trace(valuetypes)("%s field type %s at offset " UINT64_FORMAT_X,
329 p->klass()->external_name(), vk->external_name(), (uint64_t)offset);
330 }
331 }
332 }
333
334 // These functions allow a null base pointer with an arbitrary address.
335 // But if the base pointer is non-null, the offset should make some sense.
336 // That is, it should be in the range [0, MAX_OBJECT_SIZE].
337 UNSAFE_ENTRY(jobject, Unsafe_GetReference(JNIEnv *env, jobject unsafe, jobject obj, jlong offset)) {
338 oop p = JNIHandles::resolve(obj);
339 assert_field_offset_sane(p, offset);
340 oop v = HeapAccess<ON_UNKNOWN_OOP_REF>::oop_load_at(p, offset);
341 return JNIHandles::make_local(THREAD, v);
342 } UNSAFE_END
343
344 UNSAFE_ENTRY(void, Unsafe_PutReference(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jobject x_h)) {
345 oop x = JNIHandles::resolve(x_h);
346 oop p = JNIHandles::resolve(obj);
347 assert_field_offset_sane(p, offset);
348 assert(!p->is_inline_type() || p->mark().is_larval_state(), "must be an object instance or a larval inline type");
349 HeapAccess<ON_UNKNOWN_OOP_REF>::oop_store_at(p, offset, x);
350 } UNSAFE_END
351
352 UNSAFE_ENTRY(jlong, Unsafe_ValueHeaderSize(JNIEnv *env, jobject unsafe, jclass c)) {
353 Klass* k = java_lang_Class::as_Klass(JNIHandles::resolve_non_null(c));
354 InlineKlass* vk = InlineKlass::cast(k);
355 return vk->first_field_offset();
356 } UNSAFE_END
357
358 UNSAFE_ENTRY(jboolean, Unsafe_IsFlatField(JNIEnv *env, jobject unsafe, jobject o)) {
359 oop f = JNIHandles::resolve_non_null(o);
360 Klass* k = java_lang_Class::as_Klass(java_lang_reflect_Field::clazz(f));
361 int slot = java_lang_reflect_Field::slot(f);
362 return InstanceKlass::cast(k)->field_is_flat(slot);
363 } UNSAFE_END
364
365 UNSAFE_ENTRY(jboolean, Unsafe_HasNullMarker(JNIEnv *env, jobject unsafe, jobject o)) {
366 oop f = JNIHandles::resolve_non_null(o);
367 Klass* k = java_lang_Class::as_Klass(java_lang_reflect_Field::clazz(f));
368 int slot = java_lang_reflect_Field::slot(f);
369 return InstanceKlass::cast(k)->field_has_null_marker(slot);
370 } UNSAFE_END
371
372 UNSAFE_ENTRY(jint, Unsafe_NullMarkerOffset(JNIEnv *env, jobject unsafe, jobject o)) {
373 oop f = JNIHandles::resolve_non_null(o);
374 Klass* k = java_lang_Class::as_Klass(java_lang_reflect_Field::clazz(f));
375 int slot = java_lang_reflect_Field::slot(f);
376 return InstanceKlass::cast(k)->null_marker_offset(slot);
377 } UNSAFE_END
378
379 UNSAFE_ENTRY(jboolean, Unsafe_IsFlatArray(JNIEnv *env, jobject unsafe, jclass c)) {
380 Klass* k = java_lang_Class::as_Klass(JNIHandles::resolve_non_null(c));
381 return k->is_flatArray_klass();
382 } UNSAFE_END
383
384 UNSAFE_ENTRY(jobject, Unsafe_UninitializedDefaultValue(JNIEnv *env, jobject unsafe, jclass vc)) {
385 Klass* k = java_lang_Class::as_Klass(JNIHandles::resolve_non_null(vc));
386 InlineKlass* vk = InlineKlass::cast(k);
387 oop v = vk->default_value();
388 return JNIHandles::make_local(THREAD, v);
389 } UNSAFE_END
390
391 UNSAFE_ENTRY(jobject, Unsafe_GetValue(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jclass vc)) {
392 oop base = JNIHandles::resolve(obj);
393 Klass* k = java_lang_Class::as_Klass(JNIHandles::resolve_non_null(vc));
394 InlineKlass* vk = InlineKlass::cast(k);
395 assert_and_log_unsafe_value_access(base, offset, vk);
396 Handle base_h(THREAD, base);
397 oop v = vk->read_payload_from_addr(base_h(), offset, LayoutKind::PAYLOAD, CHECK_NULL);// TODO FIXME Hard coded layout kind to make the code compile, Unsafe must be upgraded to handle correct layout kind
398 return JNIHandles::make_local(THREAD, v);
399 } UNSAFE_END
400
401 UNSAFE_ENTRY(void, Unsafe_PutValue(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jclass vc, jobject value)) {
402 oop base = JNIHandles::resolve(obj);
403 Klass* k = java_lang_Class::as_Klass(JNIHandles::resolve_non_null(vc));
404 InlineKlass* vk = InlineKlass::cast(k);
405 assert(!base->is_inline_type() || base->mark().is_larval_state(), "must be an object instance or a larval inline type");
406 assert_and_log_unsafe_value_access(base, offset, vk);
407 oop v = JNIHandles::resolve(value);
408 // TODO FIXME: problem below, with new APIs, null checking depends on LayoutKind, but Unsafe APIs are not able to communicate the right layout kind yet
409 vk->write_value_to_addr(v, ((char*)(oopDesc*)base) + offset, LayoutKind::PAYLOAD, true, CHECK);// TODO FIXME Hard coded layout kind to make the code compile, Unsafe must be upgraded to handle correct layout kind
410 } UNSAFE_END
411
412 UNSAFE_ENTRY(jobject, Unsafe_MakePrivateBuffer(JNIEnv *env, jobject unsafe, jobject value)) {
413 oop v = JNIHandles::resolve_non_null(value);
414 assert(v->is_inline_type(), "must be an inline type instance");
415 Handle vh(THREAD, v);
416 InlineKlass* vk = InlineKlass::cast(v->klass());
417 instanceOop new_value = vk->allocate_instance_buffer(CHECK_NULL);
418 vk->copy_payload_to_addr(vk->data_for_oop(vh()), vk->data_for_oop(new_value), LayoutKind::PAYLOAD, false);
419 markWord mark = new_value->mark();
420 new_value->set_mark(mark.enter_larval_state());
421 return JNIHandles::make_local(THREAD, new_value);
422 } UNSAFE_END
423
424 UNSAFE_ENTRY(jobject, Unsafe_FinishPrivateBuffer(JNIEnv *env, jobject unsafe, jobject value)) {
425 oop v = JNIHandles::resolve(value);
426 assert(v->mark().is_larval_state(), "must be a larval value");
427 markWord mark = v->mark();
428 v->set_mark(mark.exit_larval_state());
429 return JNIHandles::make_local(THREAD, v);
430 } UNSAFE_END
431
432 UNSAFE_ENTRY(jobject, Unsafe_GetReferenceVolatile(JNIEnv *env, jobject unsafe, jobject obj, jlong offset)) {
433 oop p = JNIHandles::resolve(obj);
434 assert_field_offset_sane(p, offset);
435 oop v = HeapAccess<MO_SEQ_CST | ON_UNKNOWN_OOP_REF>::oop_load_at(p, offset);
436 return JNIHandles::make_local(THREAD, v);
437 } UNSAFE_END
438
439 UNSAFE_ENTRY(void, Unsafe_PutReferenceVolatile(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jobject x_h)) {
440 oop x = JNIHandles::resolve(x_h);
441 oop p = JNIHandles::resolve(obj);
442 assert_field_offset_sane(p, offset);
443 HeapAccess<MO_SEQ_CST | ON_UNKNOWN_OOP_REF>::oop_store_at(p, offset, x);
444 } UNSAFE_END
445
446 UNSAFE_ENTRY(jobject, Unsafe_GetUncompressedObject(JNIEnv *env, jobject unsafe, jlong addr)) {
447 oop v = *(oop*) (address) addr;
448 return JNIHandles::make_local(THREAD, v);
449 } UNSAFE_END
450
451 #define DEFINE_GETSETOOP(java_type, Type) \
452 \
453 UNSAFE_ENTRY_SCOPED(java_type, Unsafe_Get##Type(JNIEnv *env, jobject unsafe, jobject obj, jlong offset)) { \
454 return MemoryAccess<java_type>(thread, obj, offset).get(); \
455 } UNSAFE_END \
456 \
457 UNSAFE_ENTRY_SCOPED(void, Unsafe_Put##Type(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, java_type x)) { \
458 MemoryAccess<java_type>(thread, obj, offset).put(x); \
459 } UNSAFE_END \
460 \
461 // END DEFINE_GETSETOOP.
462
463 DEFINE_GETSETOOP(jboolean, Boolean)
464 DEFINE_GETSETOOP(jbyte, Byte)
465 DEFINE_GETSETOOP(jshort, Short);
466 DEFINE_GETSETOOP(jchar, Char);
467 DEFINE_GETSETOOP(jint, Int);
468 DEFINE_GETSETOOP(jlong, Long);
469 DEFINE_GETSETOOP(jfloat, Float);
470 DEFINE_GETSETOOP(jdouble, Double);
471
472 #undef DEFINE_GETSETOOP
473
474 #define DEFINE_GETSETOOP_VOLATILE(java_type, Type) \
475 \
476 UNSAFE_ENTRY_SCOPED(java_type, Unsafe_Get##Type##Volatile(JNIEnv *env, jobject unsafe, jobject obj, jlong offset)) { \
477 return MemoryAccess<java_type>(thread, obj, offset).get_volatile(); \
478 } UNSAFE_END \
479 \
480 UNSAFE_ENTRY_SCOPED(void, Unsafe_Put##Type##Volatile(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, java_type x)) { \
481 MemoryAccess<java_type>(thread, obj, offset).put_volatile(x); \
482 } UNSAFE_END \
483 \
484 // END DEFINE_GETSETOOP_VOLATILE.
485
486 DEFINE_GETSETOOP_VOLATILE(jboolean, Boolean)
487 DEFINE_GETSETOOP_VOLATILE(jbyte, Byte)
488 DEFINE_GETSETOOP_VOLATILE(jshort, Short);
489 DEFINE_GETSETOOP_VOLATILE(jchar, Char);
490 DEFINE_GETSETOOP_VOLATILE(jint, Int);
491 DEFINE_GETSETOOP_VOLATILE(jlong, Long);
492 DEFINE_GETSETOOP_VOLATILE(jfloat, Float);
493 DEFINE_GETSETOOP_VOLATILE(jdouble, Double);
494
495 #undef DEFINE_GETSETOOP_VOLATILE
496
497 UNSAFE_LEAF(void, Unsafe_FullFence(JNIEnv *env, jobject unsafe)) {
498 OrderAccess::fence();
499 } UNSAFE_END
500
501 ////// Allocation requests
502
503 UNSAFE_ENTRY(jobject, Unsafe_AllocateInstance(JNIEnv *env, jobject unsafe, jclass cls)) {
504 JvmtiVMObjectAllocEventCollector oam;
505 instanceOop i = InstanceKlass::allocate_instance(JNIHandles::resolve_non_null(cls), CHECK_NULL);
506 return JNIHandles::make_local(THREAD, i);
507 } UNSAFE_END
508
509 UNSAFE_LEAF(jlong, Unsafe_AllocateMemory0(JNIEnv *env, jobject unsafe, jlong size)) {
510 size_t sz = (size_t)size;
511
512 assert(is_aligned(sz, HeapWordSize), "sz not aligned");
513
514 void* x = os::malloc(sz, mtOther);
515
516 return addr_to_java(x);
517 } UNSAFE_END
518
519 UNSAFE_LEAF(jlong, Unsafe_ReallocateMemory0(JNIEnv *env, jobject unsafe, jlong addr, jlong size)) {
520 void* p = addr_from_java(addr);
521 size_t sz = (size_t)size;
522
523 assert(is_aligned(sz, HeapWordSize), "sz not aligned");
524
525 void* x = os::realloc(p, sz, mtOther);
526
527 return addr_to_java(x);
528 } UNSAFE_END
529
530 UNSAFE_LEAF(void, Unsafe_FreeMemory0(JNIEnv *env, jobject unsafe, jlong addr)) {
531 void* p = addr_from_java(addr);
532
533 os::free(p);
534 } UNSAFE_END
535
536 UNSAFE_ENTRY_SCOPED(void, Unsafe_SetMemory0(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jlong size, jbyte value)) {
537 size_t sz = (size_t)size;
538
539 oop base = JNIHandles::resolve(obj);
540 void* p = index_oop_from_field_offset_long(base, offset);
541
542 {
543 GuardUnsafeAccess guard(thread);
544 if (StubRoutines::unsafe_setmemory() != nullptr) {
545 MACOS_AARCH64_ONLY(ThreadWXEnable wx(WXExec, thread));
546 StubRoutines::UnsafeSetMemory_stub()(p, sz, value);
547 } else {
548 Copy::fill_to_memory_atomic(p, sz, value);
549 }
550 }
551 } UNSAFE_END
552
553 UNSAFE_ENTRY_SCOPED(void, Unsafe_CopyMemory0(JNIEnv *env, jobject unsafe, jobject srcObj, jlong srcOffset, jobject dstObj, jlong dstOffset, jlong size)) {
554 size_t sz = (size_t)size;
555
556 oop srcp = JNIHandles::resolve(srcObj);
557 oop dstp = JNIHandles::resolve(dstObj);
558
559 void* src = index_oop_from_field_offset_long(srcp, srcOffset);
560 void* dst = index_oop_from_field_offset_long(dstp, dstOffset);
561 {
562 GuardUnsafeAccess guard(thread);
563 if (StubRoutines::unsafe_arraycopy() != nullptr) {
564 MACOS_AARCH64_ONLY(ThreadWXEnable wx(WXExec, thread));
565 StubRoutines::UnsafeArrayCopy_stub()(src, dst, sz);
566 } else {
567 Copy::conjoint_memory_atomic(src, dst, sz);
568 }
569 }
570 } UNSAFE_END
571
572 UNSAFE_ENTRY_SCOPED(void, Unsafe_CopySwapMemory0(JNIEnv *env, jobject unsafe, jobject srcObj, jlong srcOffset, jobject dstObj, jlong dstOffset, jlong size, jlong elemSize)) {
573 size_t sz = (size_t)size;
574 size_t esz = (size_t)elemSize;
575
576 oop srcp = JNIHandles::resolve(srcObj);
577 oop dstp = JNIHandles::resolve(dstObj);
578
579 address src = (address)index_oop_from_field_offset_long(srcp, srcOffset);
580 address dst = (address)index_oop_from_field_offset_long(dstp, dstOffset);
581
582 {
583 GuardUnsafeAccess guard(thread);
584 Copy::conjoint_swap(src, dst, sz, esz);
585 }
586 } UNSAFE_END
587
588 UNSAFE_LEAF (void, Unsafe_WriteBack0(JNIEnv *env, jobject unsafe, jlong line)) {
589 assert(VM_Version::supports_data_cache_line_flush(), "should not get here");
590 #ifdef ASSERT
591 if (TraceMemoryWriteback) {
592 tty->print_cr("Unsafe: writeback 0x%p", addr_from_java(line));
593 }
594 #endif
595
596 MACOS_AARCH64_ONLY(ThreadWXEnable wx(WXExec, Thread::current()));
597 assert(StubRoutines::data_cache_writeback() != nullptr, "sanity");
598 (StubRoutines::DataCacheWriteback_stub())(addr_from_java(line));
599 } UNSAFE_END
600
601 static void doWriteBackSync0(bool is_pre)
602 {
603 MACOS_AARCH64_ONLY(ThreadWXEnable wx(WXExec, Thread::current()));
604 assert(StubRoutines::data_cache_writeback_sync() != nullptr, "sanity");
605 (StubRoutines::DataCacheWritebackSync_stub())(is_pre);
606 }
607
608 UNSAFE_LEAF (void, Unsafe_WriteBackPreSync0(JNIEnv *env, jobject unsafe)) {
609 assert(VM_Version::supports_data_cache_line_flush(), "should not get here");
610 #ifdef ASSERT
611 if (TraceMemoryWriteback) {
612 tty->print_cr("Unsafe: writeback pre-sync");
613 }
614 #endif
615
616 doWriteBackSync0(true);
617 } UNSAFE_END
618
619 UNSAFE_LEAF (void, Unsafe_WriteBackPostSync0(JNIEnv *env, jobject unsafe)) {
620 assert(VM_Version::supports_data_cache_line_flush(), "should not get here");
621 #ifdef ASSERT
622 if (TraceMemoryWriteback) {
623 tty->print_cr("Unsafe: writeback pre-sync");
624 }
625 #endif
626
627 doWriteBackSync0(false);
628 } UNSAFE_END
629
630 ////// Random queries
631
632 static jlong find_field_offset(jclass clazz, jstring name, TRAPS) {
633 assert(clazz != nullptr, "clazz must not be null");
634 assert(name != nullptr, "name must not be null");
635
636 ResourceMark rm(THREAD);
637 char *utf_name = java_lang_String::as_utf8_string(JNIHandles::resolve_non_null(name));
638
639 InstanceKlass* k = InstanceKlass::cast(java_lang_Class::as_Klass(JNIHandles::resolve_non_null(clazz)));
640
641 jint offset = -1;
642 for (JavaFieldStream fs(k); !fs.done(); fs.next()) {
643 Symbol *name = fs.name();
644 if (name->equals(utf_name)) {
645 offset = fs.offset();
646 break;
647 }
648 }
649 if (offset < 0) {
650 THROW_0(vmSymbols::java_lang_InternalError());
651 }
652 return field_offset_from_byte_offset(offset);
653 }
654
655 static jlong find_field_offset(jobject field, int must_be_static, TRAPS) {
656 assert(field != nullptr, "field must not be null");
657
658 oop reflected = JNIHandles::resolve_non_null(field);
659 oop mirror = java_lang_reflect_Field::clazz(reflected);
660 Klass* k = java_lang_Class::as_Klass(mirror);
661 int slot = java_lang_reflect_Field::slot(reflected);
662 int modifiers = java_lang_reflect_Field::modifiers(reflected);
663
664 if (must_be_static >= 0) {
665 int really_is_static = ((modifiers & JVM_ACC_STATIC) != 0);
666 if (must_be_static != really_is_static) {
667 THROW_0(vmSymbols::java_lang_IllegalArgumentException());
668 }
669 }
670
671 int offset = InstanceKlass::cast(k)->field_offset(slot);
672 return field_offset_from_byte_offset(offset);
673 }
674
675 UNSAFE_ENTRY(jlong, Unsafe_ObjectFieldOffset0(JNIEnv *env, jobject unsafe, jobject field)) {
676 return find_field_offset(field, 0, THREAD);
677 } UNSAFE_END
678
679 UNSAFE_ENTRY(jlong, Unsafe_ObjectFieldOffset1(JNIEnv *env, jobject unsafe, jclass c, jstring name)) {
680 return find_field_offset(c, name, THREAD);
681 } UNSAFE_END
682
683 UNSAFE_ENTRY(jlong, Unsafe_StaticFieldOffset0(JNIEnv *env, jobject unsafe, jobject field)) {
684 return find_field_offset(field, 1, THREAD);
685 } UNSAFE_END
686
687 UNSAFE_ENTRY(jobject, Unsafe_StaticFieldBase0(JNIEnv *env, jobject unsafe, jobject field)) {
688 assert(field != nullptr, "field must not be null");
689
690 // Note: In this VM implementation, a field address is always a short
691 // offset from the base of a klass metaobject. Thus, the full dynamic
692 // range of the return type is never used. However, some implementations
693 // might put the static field inside an array shared by many classes,
694 // or even at a fixed address, in which case the address could be quite
695 // large. In that last case, this function would return null, since
696 // the address would operate alone, without any base pointer.
697
698 oop reflected = JNIHandles::resolve_non_null(field);
699 oop mirror = java_lang_reflect_Field::clazz(reflected);
700 int modifiers = java_lang_reflect_Field::modifiers(reflected);
701
702 if ((modifiers & JVM_ACC_STATIC) == 0) {
703 THROW_NULL(vmSymbols::java_lang_IllegalArgumentException());
704 }
705
706 return JNIHandles::make_local(THREAD, mirror);
707 } UNSAFE_END
708
709 UNSAFE_ENTRY(void, Unsafe_EnsureClassInitialized0(JNIEnv *env, jobject unsafe, jobject clazz)) {
710 assert(clazz != nullptr, "clazz must not be null");
711
712 oop mirror = JNIHandles::resolve_non_null(clazz);
713
714 Klass* klass = java_lang_Class::as_Klass(mirror);
715 if (klass != nullptr && klass->should_be_initialized()) {
716 InstanceKlass* k = InstanceKlass::cast(klass);
717 k->initialize(CHECK);
718 }
719 }
720 UNSAFE_END
721
722 UNSAFE_ENTRY(jboolean, Unsafe_ShouldBeInitialized0(JNIEnv *env, jobject unsafe, jobject clazz)) {
723 assert(clazz != nullptr, "clazz must not be null");
724
725 oop mirror = JNIHandles::resolve_non_null(clazz);
726 Klass* klass = java_lang_Class::as_Klass(mirror);
727
728 if (klass != nullptr && klass->should_be_initialized()) {
729 return true;
730 }
731
732 return false;
733 }
734 UNSAFE_END
735
736 static void getBaseAndScale(int& base, int& scale, jclass clazz, TRAPS) {
737 assert(clazz != nullptr, "clazz must not be null");
738
739 oop mirror = JNIHandles::resolve_non_null(clazz);
740 Klass* k = java_lang_Class::as_Klass(mirror);
741
742 if (k == nullptr || !k->is_array_klass()) {
743 THROW(vmSymbols::java_lang_InvalidClassException());
744 } else if (k->is_objArray_klass()) {
745 base = arrayOopDesc::base_offset_in_bytes(T_OBJECT);
746 scale = heapOopSize;
747 } else if (k->is_typeArray_klass()) {
748 TypeArrayKlass* tak = TypeArrayKlass::cast(k);
749 base = tak->array_header_in_bytes();
750 assert(base == arrayOopDesc::base_offset_in_bytes(tak->element_type()), "array_header_size semantics ok");
751 scale = (1 << tak->log2_element_size());
752 } else if (k->is_flatArray_klass()) {
753 FlatArrayKlass* vak = FlatArrayKlass::cast(k);
754 InlineKlass* vklass = vak->element_klass();
755 base = vak->array_header_in_bytes();
756 scale = vak->element_byte_size();
757 } else {
758 ShouldNotReachHere();
759 }
760 }
761
762 UNSAFE_ENTRY(jint, Unsafe_ArrayBaseOffset0(JNIEnv *env, jobject unsafe, jclass clazz)) {
763 int base = 0, scale = 0;
764 getBaseAndScale(base, scale, clazz, CHECK_0);
765
766 return field_offset_from_byte_offset(base);
767 } UNSAFE_END
768
769
770 UNSAFE_ENTRY(jint, Unsafe_ArrayIndexScale0(JNIEnv *env, jobject unsafe, jclass clazz)) {
771 int base = 0, scale = 0;
772 getBaseAndScale(base, scale, clazz, CHECK_0);
773
774 // This VM packs both fields and array elements down to the byte.
775 // But watch out: If this changes, so that array references for
776 // a given primitive type (say, T_BOOLEAN) use different memory units
777 // than fields, this method MUST return zero for such arrays.
778 // For example, the VM used to store sub-word sized fields in full
779 // words in the object layout, so that accessors like getByte(Object,int)
780 // did not really do what one might expect for arrays. Therefore,
781 // this function used to report a zero scale factor, so that the user
782 // would know not to attempt to access sub-word array elements.
783 // // Code for unpacked fields:
784 // if (scale < wordSize) return 0;
785
786 // The following allows for a pretty general fieldOffset cookie scheme,
787 // but requires it to be linear in byte offset.
788 return field_offset_from_byte_offset(scale) - field_offset_from_byte_offset(0);
789 } UNSAFE_END
790
791
792 UNSAFE_ENTRY(jlong, Unsafe_GetObjectSize0(JNIEnv* env, jobject o, jobject obj))
793 oop p = JNIHandles::resolve(obj);
794 return p->size() * HeapWordSize;
795 UNSAFE_END
796
797
798 static inline void throw_new(JNIEnv *env, const char *ename) {
799 jclass cls = env->FindClass(ename);
800 if (env->ExceptionCheck()) {
801 env->ExceptionClear();
802 tty->print_cr("Unsafe: cannot throw %s because FindClass has failed", ename);
803 return;
804 }
805
806 env->ThrowNew(cls, nullptr);
807 }
808
809 static jclass Unsafe_DefineClass_impl(JNIEnv *env, jstring name, jbyteArray data, int offset, int length, jobject loader, jobject pd) {
810 // Code lifted from JDK 1.3 ClassLoader.c
811
812 jbyte *body;
813 char *utfName = nullptr;
814 jclass result = nullptr;
815 char buf[128];
816
817 assert(data != nullptr, "Class bytes must not be null");
818 assert(length >= 0, "length must not be negative: %d", length);
819
820 if (UsePerfData) {
821 ClassLoader::unsafe_defineClassCallCounter()->inc();
822 }
823
824 body = NEW_C_HEAP_ARRAY_RETURN_NULL(jbyte, length, mtInternal);
825 if (body == nullptr) {
826 throw_new(env, "java/lang/OutOfMemoryError");
827 return nullptr;
828 }
829
830 env->GetByteArrayRegion(data, offset, length, body);
831 if (env->ExceptionCheck()) {
832 goto free_body;
833 }
834
835 if (name != nullptr) {
836 uint len = env->GetStringUTFLength(name);
837 int unicode_len = env->GetStringLength(name);
838
839 if (len >= sizeof(buf)) {
840 utfName = NEW_C_HEAP_ARRAY_RETURN_NULL(char, len + 1, mtInternal);
841 if (utfName == nullptr) {
842 throw_new(env, "java/lang/OutOfMemoryError");
843 goto free_body;
844 }
845 } else {
846 utfName = buf;
847 }
848
849 env->GetStringUTFRegion(name, 0, unicode_len, utfName);
850
851 for (uint i = 0; i < len; i++) {
852 if (utfName[i] == '.') utfName[i] = '/';
853 }
854 }
855
856 result = JVM_DefineClass(env, utfName, loader, body, length, pd);
857
858 if (utfName && utfName != buf) {
859 FREE_C_HEAP_ARRAY(char, utfName);
860 }
861
862 free_body:
863 FREE_C_HEAP_ARRAY(jbyte, body);
864 return result;
865 }
866
867
868 UNSAFE_ENTRY(jclass, Unsafe_DefineClass0(JNIEnv *env, jobject unsafe, jstring name, jbyteArray data, int offset, int length, jobject loader, jobject pd)) {
869 ThreadToNativeFromVM ttnfv(thread);
870
871 return Unsafe_DefineClass_impl(env, name, data, offset, length, loader, pd);
872 } UNSAFE_END
873
874
875 UNSAFE_ENTRY(void, Unsafe_ThrowException(JNIEnv *env, jobject unsafe, jthrowable thr)) {
876 ThreadToNativeFromVM ttnfv(thread);
877 env->Throw(thr);
878 } UNSAFE_END
879
880 // JSR166 ------------------------------------------------------------------
881
882 UNSAFE_ENTRY(jobject, Unsafe_CompareAndExchangeReference(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jobject e_h, jobject x_h)) {
883 oop x = JNIHandles::resolve(x_h);
884 oop e = JNIHandles::resolve(e_h);
885 oop p = JNIHandles::resolve(obj);
886 assert_field_offset_sane(p, offset);
887 oop res = HeapAccess<ON_UNKNOWN_OOP_REF>::oop_atomic_cmpxchg_at(p, (ptrdiff_t)offset, e, x);
888 return JNIHandles::make_local(THREAD, res);
889 } UNSAFE_END
890
891 UNSAFE_ENTRY_SCOPED(jint, Unsafe_CompareAndExchangeInt(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jint e, jint x)) {
892 oop p = JNIHandles::resolve(obj);
893 volatile jint* addr = (volatile jint*)index_oop_from_field_offset_long(p, offset);
894 return Atomic::cmpxchg(addr, e, x);
895 } UNSAFE_END
896
897 UNSAFE_ENTRY_SCOPED(jlong, Unsafe_CompareAndExchangeLong(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jlong e, jlong x)) {
898 oop p = JNIHandles::resolve(obj);
899 volatile jlong* addr = (volatile jlong*)index_oop_from_field_offset_long(p, offset);
900 return Atomic::cmpxchg(addr, e, x);
901 } UNSAFE_END
902
903 UNSAFE_ENTRY(jboolean, Unsafe_CompareAndSetReference(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jobject e_h, jobject x_h)) {
904 oop x = JNIHandles::resolve(x_h);
905 oop e = JNIHandles::resolve(e_h);
906 oop p = JNIHandles::resolve(obj);
907 assert_field_offset_sane(p, offset);
908 oop ret = HeapAccess<ON_UNKNOWN_OOP_REF>::oop_atomic_cmpxchg_at(p, (ptrdiff_t)offset, e, x);
909 return ret == e;
910 } UNSAFE_END
911
912 UNSAFE_ENTRY_SCOPED(jboolean, Unsafe_CompareAndSetInt(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jint e, jint x)) {
913 oop p = JNIHandles::resolve(obj);
914 volatile jint* addr = (volatile jint*)index_oop_from_field_offset_long(p, offset);
915 return Atomic::cmpxchg(addr, e, x) == e;
916 } UNSAFE_END
917
918 UNSAFE_ENTRY_SCOPED(jboolean, Unsafe_CompareAndSetLong(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jlong e, jlong x)) {
919 oop p = JNIHandles::resolve(obj);
920 volatile jlong* addr = (volatile jlong*)index_oop_from_field_offset_long(p, offset);
921 return Atomic::cmpxchg(addr, e, x) == e;
922 } UNSAFE_END
923
924 static void post_thread_park_event(EventThreadPark* event, const oop obj, jlong timeout_nanos, jlong until_epoch_millis) {
925 assert(event != nullptr, "invariant");
926 event->set_parkedClass((obj != nullptr) ? obj->klass() : nullptr);
927 event->set_timeout(timeout_nanos);
928 event->set_until(until_epoch_millis);
929 event->set_address((obj != nullptr) ? (u8)cast_from_oop<uintptr_t>(obj) : 0);
930 event->commit();
931 }
932
933 UNSAFE_ENTRY(void, Unsafe_Park(JNIEnv *env, jobject unsafe, jboolean isAbsolute, jlong time)) {
934 HOTSPOT_THREAD_PARK_BEGIN((uintptr_t) thread->parker(), (int) isAbsolute, time);
935 EventThreadPark event;
936
937 JavaThreadParkedState jtps(thread, time != 0);
938 thread->parker()->park(isAbsolute != 0, time);
939 if (event.should_commit()) {
940 const oop obj = thread->current_park_blocker();
941 if (time == 0) {
942 post_thread_park_event(&event, obj, min_jlong, min_jlong);
943 } else {
944 if (isAbsolute != 0) {
945 post_thread_park_event(&event, obj, min_jlong, time);
946 } else {
947 post_thread_park_event(&event, obj, time, min_jlong);
948 }
949 }
950 }
951 HOTSPOT_THREAD_PARK_END((uintptr_t) thread->parker());
952 } UNSAFE_END
953
954 UNSAFE_ENTRY(void, Unsafe_Unpark(JNIEnv *env, jobject unsafe, jobject jthread)) {
955 if (jthread != nullptr) {
956 oop thread_oop = JNIHandles::resolve_non_null(jthread);
957 // Get the JavaThread* stored in the java.lang.Thread object _before_
958 // the embedded ThreadsListHandle is constructed so we know if the
959 // early life stage of the JavaThread* is protected. We use acquire
960 // here to ensure that if we see a non-nullptr value, then we also
961 // see the main ThreadsList updates from the JavaThread* being added.
962 FastThreadsListHandle ftlh(thread_oop, java_lang_Thread::thread_acquire(thread_oop));
963 JavaThread* thr = ftlh.protected_java_thread();
964 if (thr != nullptr) {
965 // The still live JavaThread* is protected by the FastThreadsListHandle
966 // so it is safe to access.
967 Parker* p = thr->parker();
968 HOTSPOT_THREAD_UNPARK((uintptr_t) p);
969 p->unpark();
970 }
971 } // FastThreadsListHandle is destroyed here.
972 } UNSAFE_END
973
974 UNSAFE_ENTRY(jint, Unsafe_GetLoadAverage0(JNIEnv *env, jobject unsafe, jdoubleArray loadavg, jint nelem)) {
975 const int max_nelem = 3;
976 double la[max_nelem];
977 jint ret;
978
979 typeArrayOop a = typeArrayOop(JNIHandles::resolve_non_null(loadavg));
980 assert(a->is_typeArray(), "must be type array");
981
982 ret = os::loadavg(la, nelem);
983 if (ret == -1) {
984 return -1;
985 }
986
987 // if successful, ret is the number of samples actually retrieved.
988 assert(ret >= 0 && ret <= max_nelem, "Unexpected loadavg return value");
989 switch(ret) {
990 case 3: a->double_at_put(2, (jdouble)la[2]); // fall through
991 case 2: a->double_at_put(1, (jdouble)la[1]); // fall through
992 case 1: a->double_at_put(0, (jdouble)la[0]); break;
993 }
994
995 return ret;
996 } UNSAFE_END
997
998
999 /// JVM_RegisterUnsafeMethods
1000
1001 #define ADR "J"
1002
1003 #define LANG "Ljava/lang/"
1004
1005 #define OBJ LANG "Object;"
1006 #define CLS LANG "Class;"
1007 #define FLD LANG "reflect/Field;"
1008 #define THR LANG "Throwable;"
1009
1010 #define DC_Args LANG "String;[BII" LANG "ClassLoader;" "Ljava/security/ProtectionDomain;"
1011 #define DAC_Args CLS "[B[" OBJ
1012
1013 #define CC (char*) /*cast a literal from (const char*)*/
1014 #define FN_PTR(f) CAST_FROM_FN_PTR(void*, &f)
1015
1016 #define DECLARE_GETPUTOOP(Type, Desc) \
1017 {CC "get" #Type, CC "(" OBJ "J)" #Desc, FN_PTR(Unsafe_Get##Type)}, \
1018 {CC "put" #Type, CC "(" OBJ "J" #Desc ")V", FN_PTR(Unsafe_Put##Type)}, \
1019 {CC "get" #Type "Volatile", CC "(" OBJ "J)" #Desc, FN_PTR(Unsafe_Get##Type##Volatile)}, \
1020 {CC "put" #Type "Volatile", CC "(" OBJ "J" #Desc ")V", FN_PTR(Unsafe_Put##Type##Volatile)}
1021
1022
1023 static JNINativeMethod jdk_internal_misc_Unsafe_methods[] = {
1024 {CC "getReference", CC "(" OBJ "J)" OBJ "", FN_PTR(Unsafe_GetReference)},
1025 {CC "putReference", CC "(" OBJ "J" OBJ ")V", FN_PTR(Unsafe_PutReference)},
1026 {CC "getReferenceVolatile", CC "(" OBJ "J)" OBJ, FN_PTR(Unsafe_GetReferenceVolatile)},
1027 {CC "putReferenceVolatile", CC "(" OBJ "J" OBJ ")V", FN_PTR(Unsafe_PutReferenceVolatile)},
1028
1029 {CC "isFlatArray", CC "(" CLS ")Z", FN_PTR(Unsafe_IsFlatArray)},
1030 {CC "isFlatField0", CC "(" OBJ ")Z", FN_PTR(Unsafe_IsFlatField)},
1031 {CC "hasNullMarker0" , CC "(" OBJ ")Z", FN_PTR(Unsafe_HasNullMarker)},
1032 {CC "nullMarkerOffset0", CC "(" OBJ ")I", FN_PTR(Unsafe_NullMarkerOffset)},
1033 {CC "getValue", CC "(" OBJ "J" CLS ")" OBJ, FN_PTR(Unsafe_GetValue)},
1034 {CC "putValue", CC "(" OBJ "J" CLS OBJ ")V", FN_PTR(Unsafe_PutValue)},
1035 {CC "uninitializedDefaultValue", CC "(" CLS ")" OBJ, FN_PTR(Unsafe_UninitializedDefaultValue)},
1036 {CC "makePrivateBuffer", CC "(" OBJ ")" OBJ, FN_PTR(Unsafe_MakePrivateBuffer)},
1037 {CC "finishPrivateBuffer", CC "(" OBJ ")" OBJ, FN_PTR(Unsafe_FinishPrivateBuffer)},
1038 {CC "valueHeaderSize", CC "(" CLS ")J", FN_PTR(Unsafe_ValueHeaderSize)},
1039
1040 {CC "getUncompressedObject", CC "(" ADR ")" OBJ, FN_PTR(Unsafe_GetUncompressedObject)},
1041
1042 DECLARE_GETPUTOOP(Boolean, Z),
1043 DECLARE_GETPUTOOP(Byte, B),
1044 DECLARE_GETPUTOOP(Short, S),
1045 DECLARE_GETPUTOOP(Char, C),
1046 DECLARE_GETPUTOOP(Int, I),
1047 DECLARE_GETPUTOOP(Long, J),
1048 DECLARE_GETPUTOOP(Float, F),
1049 DECLARE_GETPUTOOP(Double, D),
1050
1051 {CC "allocateMemory0", CC "(J)" ADR, FN_PTR(Unsafe_AllocateMemory0)},
1052 {CC "reallocateMemory0", CC "(" ADR "J)" ADR, FN_PTR(Unsafe_ReallocateMemory0)},
1053 {CC "freeMemory0", CC "(" ADR ")V", FN_PTR(Unsafe_FreeMemory0)},
1054
1055 {CC "objectFieldOffset0", CC "(" FLD ")J", FN_PTR(Unsafe_ObjectFieldOffset0)},
1056 {CC "objectFieldOffset1", CC "(" CLS LANG "String;)J", FN_PTR(Unsafe_ObjectFieldOffset1)},
1057 {CC "staticFieldOffset0", CC "(" FLD ")J", FN_PTR(Unsafe_StaticFieldOffset0)},
1058 {CC "staticFieldBase0", CC "(" FLD ")" OBJ, FN_PTR(Unsafe_StaticFieldBase0)},
1059 {CC "ensureClassInitialized0", CC "(" CLS ")V", FN_PTR(Unsafe_EnsureClassInitialized0)},
1060 {CC "arrayBaseOffset0", CC "(" CLS ")I", FN_PTR(Unsafe_ArrayBaseOffset0)},
1061 {CC "arrayIndexScale0", CC "(" CLS ")I", FN_PTR(Unsafe_ArrayIndexScale0)},
1062 {CC "getObjectSize0", CC "(Ljava/lang/Object;)J", FN_PTR(Unsafe_GetObjectSize0)},
1063
1064 {CC "defineClass0", CC "(" DC_Args ")" CLS, FN_PTR(Unsafe_DefineClass0)},
1065 {CC "allocateInstance", CC "(" CLS ")" OBJ, FN_PTR(Unsafe_AllocateInstance)},
1066 {CC "throwException", CC "(" THR ")V", FN_PTR(Unsafe_ThrowException)},
1067 {CC "compareAndSetReference",CC "(" OBJ "J" OBJ "" OBJ ")Z", FN_PTR(Unsafe_CompareAndSetReference)},
1068 {CC "compareAndSetInt", CC "(" OBJ "J""I""I"")Z", FN_PTR(Unsafe_CompareAndSetInt)},
1069 {CC "compareAndSetLong", CC "(" OBJ "J""J""J"")Z", FN_PTR(Unsafe_CompareAndSetLong)},
1070 {CC "compareAndExchangeReference", CC "(" OBJ "J" OBJ "" OBJ ")" OBJ, FN_PTR(Unsafe_CompareAndExchangeReference)},
1071 {CC "compareAndExchangeInt", CC "(" OBJ "J""I""I"")I", FN_PTR(Unsafe_CompareAndExchangeInt)},
1072 {CC "compareAndExchangeLong", CC "(" OBJ "J""J""J"")J", FN_PTR(Unsafe_CompareAndExchangeLong)},
1073
1074 {CC "park", CC "(ZJ)V", FN_PTR(Unsafe_Park)},
1075 {CC "unpark", CC "(" OBJ ")V", FN_PTR(Unsafe_Unpark)},
1076
1077 {CC "getLoadAverage0", CC "([DI)I", FN_PTR(Unsafe_GetLoadAverage0)},
1078
1079 {CC "copyMemory0", CC "(" OBJ "J" OBJ "JJ)V", FN_PTR(Unsafe_CopyMemory0)},
1080 {CC "copySwapMemory0", CC "(" OBJ "J" OBJ "JJJ)V", FN_PTR(Unsafe_CopySwapMemory0)},
1081 {CC "writeback0", CC "(" "J" ")V", FN_PTR(Unsafe_WriteBack0)},
1082 {CC "writebackPreSync0", CC "()V", FN_PTR(Unsafe_WriteBackPreSync0)},
1083 {CC "writebackPostSync0", CC "()V", FN_PTR(Unsafe_WriteBackPostSync0)},
1084 {CC "setMemory0", CC "(" OBJ "JJB)V", FN_PTR(Unsafe_SetMemory0)},
1085
1086 {CC "shouldBeInitialized0", CC "(" CLS ")Z", FN_PTR(Unsafe_ShouldBeInitialized0)},
1087
1088 {CC "fullFence", CC "()V", FN_PTR(Unsafe_FullFence)},
1089 };
1090
1091 #undef CC
1092 #undef FN_PTR
1093
1094 #undef ADR
1095 #undef LANG
1096 #undef OBJ
1097 #undef CLS
1098 #undef FLD
1099 #undef THR
1100 #undef DC_Args
1101 #undef DAC_Args
1102
1103 #undef DECLARE_GETPUTOOP
1104
1105
1106 // This function is exported, used by NativeLookup.
1107 // The Unsafe_xxx functions above are called only from the interpreter.
1108 // The optimizer looks at names and signatures to recognize
1109 // individual functions.
1110
1111 JVM_ENTRY(void, JVM_RegisterJDKInternalMiscUnsafeMethods(JNIEnv *env, jclass unsafeclass)) {
1112 ThreadToNativeFromVM ttnfv(thread);
1113
1114 int ok = env->RegisterNatives(unsafeclass, jdk_internal_misc_Unsafe_methods, sizeof(jdk_internal_misc_Unsafe_methods)/sizeof(JNINativeMethod));
1115 guarantee(ok == 0, "register jdk.internal.misc.Unsafe natives");
1116 } JVM_END