1 /*
2 * Copyright (c) 2000, 2019, 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 "jni.h"
27 #include "jvm.h"
28 #include "classfile/classFileStream.hpp"
29 #include "classfile/vmSymbols.hpp"
30 #include "jfr/jfrEvents.hpp"
31 #include "memory/allocation.inline.hpp"
32 #include "memory/resourceArea.hpp"
33 #include "logging/log.hpp"
34 #include "logging/logStream.hpp"
35 #include "oops/access.inline.hpp"
36 #include "oops/fieldStreams.hpp"
37 #include "oops/objArrayOop.inline.hpp"
38 #include "oops/oop.inline.hpp"
39 #include "oops/typeArrayOop.inline.hpp"
40 #include "oops/valueArrayKlass.hpp"
41 #include "oops/valueArrayOop.hpp"
42 #include "oops/valueArrayOop.inline.hpp"
43 #include "prims/unsafe.hpp"
44 #include "runtime/atomic.hpp"
45 #include "runtime/fieldDescriptor.inline.hpp"
46 #include "runtime/globals.hpp"
47 #include "runtime/handles.inline.hpp"
48 #include "runtime/interfaceSupport.inline.hpp"
49 #include "runtime/jniHandles.inline.hpp"
50 #include "runtime/orderAccess.hpp"
51 #include "runtime/reflection.hpp"
52 #include "runtime/thread.hpp"
53 #include "runtime/threadSMR.hpp"
54 #include "runtime/vm_version.hpp"
55 #include "services/threadService.hpp"
56 #include "utilities/align.hpp"
57 #include "utilities/copy.hpp"
58 #include "utilities/dtrace.hpp"
59 #include "utilities/macros.hpp"
60
61 /**
62 * Implementation of the jdk.internal.misc.Unsafe class
63 */
64
65
66 #define MAX_OBJECT_SIZE \
67 ( arrayOopDesc::header_size(T_DOUBLE) * HeapWordSize \
68 + ((julong)max_jint * sizeof(double)) )
69
70
71 #define UNSAFE_ENTRY(result_type, header) \
72 JVM_ENTRY(static result_type, header)
73
74 #define UNSAFE_LEAF(result_type, header) \
75 JVM_LEAF(static result_type, header)
76
77 #define UNSAFE_END JVM_END
78
79
80 static inline void* addr_from_java(jlong addr) {
81 // This assert fails in a variety of ways on 32-bit systems.
82 // It is impossible to predict whether native code that converts
83 // pointers to longs will sign-extend or zero-extend the addresses.
84 //assert(addr == (uintptr_t)addr, "must not be odd high bits");
85 return (void*)(uintptr_t)addr;
86 }
87
88 static inline jlong addr_to_java(void* p) {
89 assert(p == (void*)(uintptr_t)p, "must not be odd high bits");
90 return (uintptr_t)p;
91 }
92
93
94 // Note: The VM's obj_field and related accessors use byte-scaled
95 // ("unscaled") offsets, just as the unsafe methods do.
96
97 // However, the method Unsafe.fieldOffset explicitly declines to
98 // guarantee this. The field offset values manipulated by the Java user
99 // through the Unsafe API are opaque cookies that just happen to be byte
100 // offsets. We represent this state of affairs by passing the cookies
101 // through conversion functions when going between the VM and the Unsafe API.
102 // The conversion functions just happen to be no-ops at present.
103
104 static inline jlong field_offset_to_byte_offset(jlong field_offset) {
105 return field_offset;
106 }
107
108 static inline jlong field_offset_from_byte_offset(jlong byte_offset) {
109 return byte_offset;
110 }
111
112 static inline void assert_field_offset_sane(oop p, jlong field_offset) {
113 #ifdef ASSERT
114 jlong byte_offset = field_offset_to_byte_offset(field_offset);
115
116 if (p != NULL) {
117 assert(byte_offset >= 0 && byte_offset <= (jlong)MAX_OBJECT_SIZE, "sane offset");
118 if (byte_offset == (jint)byte_offset) {
119 void* ptr_plus_disp = (address)p + byte_offset;
120 assert(p->field_addr_raw((jint)byte_offset) == ptr_plus_disp,
121 "raw [ptr+disp] must be consistent with oop::field_addr_raw");
122 }
123 jlong p_size = HeapWordSize * (jlong)(p->size());
124 assert(byte_offset < p_size, "Unsafe access: offset " INT64_FORMAT " > object's size " INT64_FORMAT, (int64_t)byte_offset, (int64_t)p_size);
125 }
126 #endif
127 }
128
129 static inline void* index_oop_from_field_offset_long(oop p, jlong field_offset) {
130 assert_field_offset_sane(p, field_offset);
131 jlong byte_offset = field_offset_to_byte_offset(field_offset);
132
133 if (p != NULL) {
134 p = Access<>::resolve(p);
135 }
136
137 if (sizeof(char*) == sizeof(jint)) { // (this constant folds!)
138 return (address)p + (jint) byte_offset;
139 } else {
140 return (address)p + byte_offset;
141 }
142 }
143
144 // Externally callable versions:
145 // (Use these in compiler intrinsics which emulate unsafe primitives.)
146 jlong Unsafe_field_offset_to_byte_offset(jlong field_offset) {
147 return field_offset;
148 }
149 jlong Unsafe_field_offset_from_byte_offset(jlong byte_offset) {
150 return byte_offset;
151 }
152
153 ///// Data read/writes on the Java heap and in native (off-heap) memory
154
155 /**
156 * Helper class for accessing memory.
157 *
158 * Normalizes values and wraps accesses in
159 * JavaThread::doing_unsafe_access() if needed.
160 */
161 template <typename T>
162 class MemoryAccess : StackObj {
163 JavaThread* _thread;
164 oop _obj;
165 ptrdiff_t _offset;
166
167 // Resolves and returns the address of the memory access.
168 // This raw memory access may fault, so we make sure it happens within the
169 // guarded scope by making the access volatile at least. Since the store
170 // of Thread::set_doing_unsafe_access() is also volatile, these accesses
171 // can not be reordered by the compiler. Therefore, if the access triggers
172 // a fault, we will know that Thread::doing_unsafe_access() returns true.
173 volatile T* addr() {
174 void* addr = index_oop_from_field_offset_long(_obj, _offset);
175 return static_cast<volatile T*>(addr);
176 }
177
178 template <typename U>
179 U normalize_for_write(U x) {
180 return x;
181 }
182
183 jboolean normalize_for_write(jboolean x) {
184 return x & 1;
185 }
186
187 template <typename U>
188 U normalize_for_read(U x) {
189 return x;
190 }
191
192 jboolean normalize_for_read(jboolean x) {
193 return x != 0;
194 }
195
196 /**
197 * Helper class to wrap memory accesses in JavaThread::doing_unsafe_access()
198 */
199 class GuardUnsafeAccess {
200 JavaThread* _thread;
201
202 public:
203 GuardUnsafeAccess(JavaThread* thread) : _thread(thread) {
204 // native/off-heap access which may raise SIGBUS if accessing
205 // memory mapped file data in a region of the file which has
206 // been truncated and is now invalid
207 _thread->set_doing_unsafe_access(true);
208 }
209
210 ~GuardUnsafeAccess() {
211 _thread->set_doing_unsafe_access(false);
212 }
213 };
214
215 public:
216 MemoryAccess(JavaThread* thread, jobject obj, jlong offset)
217 : _thread(thread), _obj(JNIHandles::resolve(obj)), _offset((ptrdiff_t)offset) {
218 assert_field_offset_sane(_obj, offset);
219 }
220
221 T get() {
222 if (_obj == NULL) {
223 GuardUnsafeAccess guard(_thread);
224 T ret = RawAccess<>::load(addr());
225 return normalize_for_read(ret);
226 } else {
227 T ret = HeapAccess<>::load_at(_obj, _offset);
228 return normalize_for_read(ret);
229 }
230 }
231
232 void put(T x) {
233 if (_obj == NULL) {
234 GuardUnsafeAccess guard(_thread);
235 RawAccess<>::store(addr(), normalize_for_write(x));
236 } else {
237 assert(!_obj->is_value() || _obj->mark()->is_larval_state(), "must be an object instance or a larval value");
238 HeapAccess<>::store_at(_obj, _offset, normalize_for_write(x));
239 }
240 }
241
242 T get_volatile() {
243 if (_obj == NULL) {
244 GuardUnsafeAccess guard(_thread);
245 volatile T ret = RawAccess<MO_SEQ_CST>::load(addr());
246 return normalize_for_read(ret);
247 } else {
248 T ret = HeapAccess<MO_SEQ_CST>::load_at(_obj, _offset);
249 return normalize_for_read(ret);
250 }
251 }
252
253 void put_volatile(T x) {
254 if (_obj == NULL) {
255 GuardUnsafeAccess guard(_thread);
256 RawAccess<MO_SEQ_CST>::store(addr(), normalize_for_write(x));
257 } else {
258 HeapAccess<MO_SEQ_CST>::store_at(_obj, _offset, normalize_for_write(x));
259 }
260 }
261 };
262
263 #ifdef ASSERT
264 /*
265 * Get the field descriptor of the field of the given object at the given offset.
266 */
267 static bool get_field_descriptor(oop p, jlong offset, fieldDescriptor* fd) {
268 bool found = false;
269 Klass* k = p->klass();
270 if (k->is_instance_klass()) {
271 InstanceKlass* ik = InstanceKlass::cast(k);
272 found = ik->find_field_from_offset((int)offset, false, fd);
273 if (!found && ik->is_mirror_instance_klass()) {
274 Klass* k2 = java_lang_Class::as_Klass(p);
275 if (k2->is_instance_klass()) {
276 ik = InstanceKlass::cast(k2);
277 found = ik->find_field_from_offset((int)offset, true, fd);
278 }
279 }
280 }
281 return found;
282 }
283 #endif // ASSERT
284
285 static void assert_and_log_unsafe_value_access(oop p, jlong offset, ValueKlass* vk) {
286 Klass* k = p->klass();
287 #ifdef ASSERT
288 if (k->is_instance_klass()) {
289 assert_field_offset_sane(p, offset);
290 fieldDescriptor fd;
291 bool found = get_field_descriptor(p, offset, &fd);
292 if (found) {
293 assert(found, "value field not found");
294 assert(fd.is_flattened(), "field not flat");
295 } else {
296 if (log_is_enabled(Trace, valuetypes)) {
297 log_trace(valuetypes)("not a field in %s at offset " SIZE_FORMAT_HEX,
298 p->klass()->external_name(), offset);
299 }
300 }
301 } else if (k->is_valueArray_klass()) {
302 ValueArrayKlass* vak = ValueArrayKlass::cast(k);
303 int index = (offset - vak->array_header_in_bytes()) / vak->element_byte_size();
304 address dest = (address)((valueArrayOop)p)->value_at_addr(index, vak->layout_helper());
305 assert(dest == ((address)p) + offset, "invalid offset");
306 } else {
307 ShouldNotReachHere();
308 }
309 #endif // ASSERT
310 if (log_is_enabled(Trace, valuetypes)) {
311 if (k->is_valueArray_klass()) {
312 ValueArrayKlass* vak = ValueArrayKlass::cast(k);
313 int index = (offset - vak->array_header_in_bytes()) / vak->element_byte_size();
314 address dest = (address)((valueArrayOop)p)->value_at_addr(index, vak->layout_helper());
315 log_trace(valuetypes)("%s array type %s index %d element size %d offset " SIZE_FORMAT_HEX " at " INTPTR_FORMAT,
316 p->klass()->external_name(), vak->external_name(),
317 index, vak->element_byte_size(), offset, p2i(dest));
318 } else {
319 log_trace(valuetypes)("%s field type %s at offset " SIZE_FORMAT_HEX,
320 p->klass()->external_name(), vk->external_name(), offset);
321 }
322 }
323 }
324
325 // These functions allow a null base pointer with an arbitrary address.
326 // But if the base pointer is non-null, the offset should make some sense.
327 // That is, it should be in the range [0, MAX_OBJECT_SIZE].
328 UNSAFE_ENTRY(jobject, Unsafe_GetReference(JNIEnv *env, jobject unsafe, jobject obj, jlong offset)) {
329 oop p = JNIHandles::resolve(obj);
330 assert_field_offset_sane(p, offset);
331 oop v = HeapAccess<ON_UNKNOWN_OOP_REF>::oop_load_at(p, offset);
332 return JNIHandles::make_local(env, v);
333 } UNSAFE_END
334
335 UNSAFE_ENTRY(void, Unsafe_PutReference(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jobject x_h)) {
336 oop x = JNIHandles::resolve(x_h);
337 oop p = JNIHandles::resolve(obj);
338 assert_field_offset_sane(p, offset);
339 assert(!p->is_value() || p->mark()->is_larval_state(), "must be an object instance or a larval value");
340 HeapAccess<ON_UNKNOWN_OOP_REF>::oop_store_at(p, offset, x);
341 } UNSAFE_END
342
343 UNSAFE_ENTRY(jlong, Unsafe_ValueHeaderSize(JNIEnv *env, jobject unsafe, jclass c)) {
344 Klass* k = java_lang_Class::as_Klass(JNIHandles::resolve_non_null(c));
345 ValueKlass* vk = ValueKlass::cast(k);
346 return vk->first_field_offset();
347 } UNSAFE_END
348
349 UNSAFE_ENTRY(jboolean, Unsafe_IsFlattenedArray(JNIEnv *env, jobject unsafe, jclass c)) {
350 Klass* k = java_lang_Class::as_Klass(JNIHandles::resolve_non_null(c));
351 return k->is_valueArray_klass();
352 } UNSAFE_END
353
354 UNSAFE_ENTRY(jobject, Unsafe_UninitializedDefaultValue(JNIEnv *env, jobject unsafe, jclass vc)) {
355 Klass* k = java_lang_Class::as_Klass(JNIHandles::resolve_non_null(vc));
356 ValueKlass* vk = ValueKlass::cast(k);
357 oop v = vk->default_value();
358 return JNIHandles::make_local(env, v);
359 } UNSAFE_END
360
361 UNSAFE_ENTRY(jobject, Unsafe_GetValue(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jclass vc)) {
362 oop base = JNIHandles::resolve(obj);
363 Klass* k = java_lang_Class::as_Klass(JNIHandles::resolve_non_null(vc));
364 ValueKlass* vk = ValueKlass::cast(k);
365 assert_and_log_unsafe_value_access(base, offset, vk);
366 Handle base_h(THREAD, base);
367 oop v = vk->allocate_instance(CHECK_NULL); // allocate instance
368 vk->initialize(CHECK_NULL); // If field is a default value, value class might not be initialized yet
369 vk->value_store(((address)(oopDesc*)base_h()) + offset,
370 vk->data_for_oop(v),
371 true, true);
372 return JNIHandles::make_local(env, v);
373 } UNSAFE_END
374
375 UNSAFE_ENTRY(void, Unsafe_PutValue(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jclass vc, jobject value)) {
376 oop base = JNIHandles::resolve(obj);
377 Klass* k = java_lang_Class::as_Klass(JNIHandles::resolve_non_null(vc));
378 ValueKlass* vk = ValueKlass::cast(k);
379 assert(!base->is_value() || base->mark()->is_larval_state(), "must be an object instance or a larval value");
380 assert_and_log_unsafe_value_access(base, offset, vk);
381 oop v = JNIHandles::resolve(value);
382 vk->value_store(vk->data_for_oop(v),
383 ((address)(oopDesc*)base) + offset, true, true);
384 } UNSAFE_END
385
386 UNSAFE_ENTRY(jobject, Unsafe_MakePrivateBuffer(JNIEnv *env, jobject unsafe, jobject value)) {
387 oop v = JNIHandles::resolve_non_null(value);
388 assert(v->is_value(), "must be a value instance");
389 Handle vh(THREAD, v);
390 ValueKlass* vk = ValueKlass::cast(v->klass());
391 instanceOop new_value = vk->allocate_instance(CHECK_NULL);
392 vk->value_store(vk->data_for_oop(vh()), vk->data_for_oop(new_value), true, false);
393 markOop mark = new_value->mark();
394 new_value->set_mark(mark->enter_larval_state());
395 return JNIHandles::make_local(env, new_value);
396 } UNSAFE_END
397
398 UNSAFE_ENTRY(jobject, Unsafe_FinishPrivateBuffer(JNIEnv *env, jobject unsafe, jobject value)) {
399 oop v = JNIHandles::resolve(value);
400 assert(v->mark()->is_larval_state(), "must be a larval value");
401 markOop mark = v->mark();
402 v->set_mark(mark->exit_larval_state());
403 return JNIHandles::make_local(env, v);
404 } UNSAFE_END
405
406 UNSAFE_ENTRY(jobject, Unsafe_GetReferenceVolatile(JNIEnv *env, jobject unsafe, jobject obj, jlong offset)) {
407 oop p = JNIHandles::resolve(obj);
408 assert_field_offset_sane(p, offset);
409 oop v = HeapAccess<MO_SEQ_CST | ON_UNKNOWN_OOP_REF>::oop_load_at(p, offset);
410 return JNIHandles::make_local(env, v);
411 } UNSAFE_END
412
413 UNSAFE_ENTRY(void, Unsafe_PutReferenceVolatile(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jobject x_h)) {
414 oop x = JNIHandles::resolve(x_h);
415 oop p = JNIHandles::resolve(obj);
416 assert_field_offset_sane(p, offset);
417 HeapAccess<MO_SEQ_CST | ON_UNKNOWN_OOP_REF>::oop_store_at(p, offset, x);
418 } UNSAFE_END
419
420 UNSAFE_ENTRY(jobject, Unsafe_GetUncompressedObject(JNIEnv *env, jobject unsafe, jlong addr)) {
421 oop v = *(oop*) (address) addr;
422 return JNIHandles::make_local(env, v);
423 } UNSAFE_END
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<java_type>(thread, obj, offset).get(); \
441 } UNSAFE_END \
442 \
443 UNSAFE_ENTRY(void, Unsafe_Put##Type(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, java_type x)) { \
444 MemoryAccess<java_type>(thread, obj, offset).put(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<java_type>(thread, obj, offset).get_volatile(); \
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<java_type>(thread, obj, offset).put_volatile(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(jlong, Long);
478 DEFINE_GETSETOOP_VOLATILE(jfloat, Float);
479 DEFINE_GETSETOOP_VOLATILE(jdouble, Double);
480
481 #undef DEFINE_GETSETOOP_VOLATILE
482
483 UNSAFE_LEAF(void, Unsafe_LoadFence(JNIEnv *env, jobject unsafe)) {
484 OrderAccess::acquire();
485 } UNSAFE_END
486
487 UNSAFE_LEAF(void, Unsafe_StoreFence(JNIEnv *env, jobject unsafe)) {
488 OrderAccess::release();
489 } UNSAFE_END
490
491 UNSAFE_LEAF(void, Unsafe_FullFence(JNIEnv *env, jobject unsafe)) {
492 OrderAccess::fence();
493 } UNSAFE_END
494
495 ////// Allocation requests
496
497 UNSAFE_ENTRY(jobject, Unsafe_AllocateInstance(JNIEnv *env, jobject unsafe, jclass cls)) {
498 ThreadToNativeFromVM ttnfv(thread);
499 return env->AllocObject(cls);
500 } UNSAFE_END
501
502 UNSAFE_ENTRY(jlong, Unsafe_AllocateMemory0(JNIEnv *env, jobject unsafe, jlong size)) {
503 size_t sz = (size_t)size;
504
505 sz = align_up(sz, HeapWordSize);
506 void* x = os::malloc(sz, mtOther);
507
508 return addr_to_java(x);
509 } UNSAFE_END
510
511 UNSAFE_ENTRY(jlong, Unsafe_ReallocateMemory0(JNIEnv *env, jobject unsafe, jlong addr, jlong size)) {
512 void* p = addr_from_java(addr);
513 size_t sz = (size_t)size;
514 sz = align_up(sz, HeapWordSize);
515
516 void* x = os::realloc(p, sz, mtOther);
517
518 return addr_to_java(x);
519 } UNSAFE_END
520
521 UNSAFE_ENTRY(void, Unsafe_FreeMemory0(JNIEnv *env, jobject unsafe, jlong addr)) {
522 void* p = addr_from_java(addr);
523
524 os::free(p);
525 } UNSAFE_END
526
527 UNSAFE_ENTRY(void, Unsafe_SetMemory0(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jlong size, jbyte value)) {
528 size_t sz = (size_t)size;
529
530 oop base = JNIHandles::resolve(obj);
531 void* p = index_oop_from_field_offset_long(base, offset);
532
533 Copy::fill_to_memory_atomic(p, sz, value);
534 } UNSAFE_END
535
536 UNSAFE_ENTRY(void, Unsafe_CopyMemory0(JNIEnv *env, jobject unsafe, jobject srcObj, jlong srcOffset, jobject dstObj, jlong dstOffset, jlong size)) {
537 size_t sz = (size_t)size;
538
539 oop srcp = JNIHandles::resolve(srcObj);
540 oop dstp = JNIHandles::resolve(dstObj);
541
542 void* src = index_oop_from_field_offset_long(srcp, srcOffset);
543 void* dst = index_oop_from_field_offset_long(dstp, dstOffset);
544
545 Copy::conjoint_memory_atomic(src, dst, sz);
546 } UNSAFE_END
547
548 // This function is a leaf since if the source and destination are both in native memory
549 // the copy may potentially be very large, and we don't want to disable GC if we can avoid it.
550 // If either source or destination (or both) are on the heap, the function will enter VM using
551 // JVM_ENTRY_FROM_LEAF
552 UNSAFE_LEAF(void, Unsafe_CopySwapMemory0(JNIEnv *env, jobject unsafe, jobject srcObj, jlong srcOffset, jobject dstObj, jlong dstOffset, jlong size, jlong elemSize)) {
553 size_t sz = (size_t)size;
554 size_t esz = (size_t)elemSize;
555
556 if (srcObj == NULL && dstObj == NULL) {
557 // Both src & dst are in native memory
558 address src = (address)srcOffset;
559 address dst = (address)dstOffset;
560
561 Copy::conjoint_swap(src, dst, sz, esz);
562 } else {
563 // At least one of src/dst are on heap, transition to VM to access raw pointers
564
565 JVM_ENTRY_FROM_LEAF(env, void, Unsafe_CopySwapMemory0) {
566 oop srcp = JNIHandles::resolve(srcObj);
567 oop dstp = JNIHandles::resolve(dstObj);
568
569 address src = (address)index_oop_from_field_offset_long(srcp, srcOffset);
570 address dst = (address)index_oop_from_field_offset_long(dstp, dstOffset);
571
572 Copy::conjoint_swap(src, dst, sz, esz);
573 } JVM_END
574 }
575 } UNSAFE_END
576
577 ////// Random queries
578
579 UNSAFE_LEAF(jint, Unsafe_AddressSize0(JNIEnv *env, jobject unsafe)) {
580 return sizeof(void*);
581 } UNSAFE_END
582
583 UNSAFE_LEAF(jint, Unsafe_PageSize()) {
584 return os::vm_page_size();
585 } UNSAFE_END
586
587 static jlong find_field_offset(jclass clazz, jstring name, TRAPS) {
588 assert(clazz != NULL, "clazz must not be NULL");
589 assert(name != NULL, "name must not be NULL");
590
591 ResourceMark rm(THREAD);
592 char *utf_name = java_lang_String::as_utf8_string(JNIHandles::resolve_non_null(name));
593
594 InstanceKlass* k = InstanceKlass::cast(java_lang_Class::as_Klass(JNIHandles::resolve_non_null(clazz)));
595
596 jint offset = -1;
597 for (JavaFieldStream fs(k); !fs.done(); fs.next()) {
598 Symbol *name = fs.name();
599 if (name->equals(utf_name)) {
600 offset = fs.offset();
601 break;
602 }
603 }
604 if (offset < 0) {
605 THROW_0(vmSymbols::java_lang_InternalError());
606 }
607 return field_offset_from_byte_offset(offset);
608 }
609
610 static jlong find_field_offset(jobject field, int must_be_static, TRAPS) {
611 assert(field != NULL, "field must not be NULL");
612
613 oop reflected = JNIHandles::resolve_non_null(field);
614 oop mirror = java_lang_reflect_Field::clazz(reflected);
615 Klass* k = java_lang_Class::as_Klass(mirror);
616 int slot = java_lang_reflect_Field::slot(reflected);
617 int modifiers = java_lang_reflect_Field::modifiers(reflected);
618
619 if (must_be_static >= 0) {
620 int really_is_static = ((modifiers & JVM_ACC_STATIC) != 0);
621 if (must_be_static != really_is_static) {
622 THROW_0(vmSymbols::java_lang_IllegalArgumentException());
623 }
624 }
625
626 int offset = InstanceKlass::cast(k)->field_offset(slot);
627 return field_offset_from_byte_offset(offset);
628 }
629
630 UNSAFE_ENTRY(jlong, Unsafe_ObjectFieldOffset0(JNIEnv *env, jobject unsafe, jobject field)) {
631 return find_field_offset(field, 0, THREAD);
632 } UNSAFE_END
633
634 UNSAFE_ENTRY(jlong, Unsafe_ObjectFieldOffset1(JNIEnv *env, jobject unsafe, jclass c, jstring name)) {
635 return find_field_offset(c, name, THREAD);
636 } UNSAFE_END
637
638 UNSAFE_ENTRY(jlong, Unsafe_StaticFieldOffset0(JNIEnv *env, jobject unsafe, jobject field)) {
639 return find_field_offset(field, 1, THREAD);
640 } UNSAFE_END
641
642 UNSAFE_ENTRY(jobject, Unsafe_StaticFieldBase0(JNIEnv *env, jobject unsafe, jobject field)) {
643 assert(field != NULL, "field must not be NULL");
644
645 // Note: In this VM implementation, a field address is always a short
646 // offset from the base of a a klass metaobject. Thus, the full dynamic
647 // range of the return type is never used. However, some implementations
648 // might put the static field inside an array shared by many classes,
649 // or even at a fixed address, in which case the address could be quite
650 // large. In that last case, this function would return NULL, since
651 // the address would operate alone, without any base pointer.
652
653 oop reflected = JNIHandles::resolve_non_null(field);
654 oop mirror = java_lang_reflect_Field::clazz(reflected);
655 int modifiers = java_lang_reflect_Field::modifiers(reflected);
656
657 if ((modifiers & JVM_ACC_STATIC) == 0) {
658 THROW_0(vmSymbols::java_lang_IllegalArgumentException());
659 }
660
661 return JNIHandles::make_local(env, mirror);
662 } UNSAFE_END
663
664 UNSAFE_ENTRY(void, Unsafe_EnsureClassInitialized0(JNIEnv *env, jobject unsafe, jobject clazz)) {
665 assert(clazz != NULL, "clazz must not be NULL");
666
667 oop mirror = JNIHandles::resolve_non_null(clazz);
668
669 Klass* klass = java_lang_Class::as_Klass(mirror);
670 if (klass != NULL && klass->should_be_initialized()) {
671 InstanceKlass* k = InstanceKlass::cast(klass);
672 k->initialize(CHECK);
673 }
674 }
675 UNSAFE_END
676
677 UNSAFE_ENTRY(jboolean, Unsafe_ShouldBeInitialized0(JNIEnv *env, jobject unsafe, jobject clazz)) {
678 assert(clazz != NULL, "clazz must not be NULL");
679
680 oop mirror = JNIHandles::resolve_non_null(clazz);
681 Klass* klass = java_lang_Class::as_Klass(mirror);
682
683 if (klass != NULL && klass->should_be_initialized()) {
684 return true;
685 }
686
687 return false;
688 }
689 UNSAFE_END
690
691 static void getBaseAndScale(int& base, int& scale, jclass clazz, TRAPS) {
692 assert(clazz != NULL, "clazz must not be NULL");
693
694 oop mirror = JNIHandles::resolve_non_null(clazz);
695 Klass* k = java_lang_Class::as_Klass(mirror);
696
697 if (k == NULL || !k->is_array_klass()) {
698 THROW(vmSymbols::java_lang_InvalidClassException());
699 } else if (k->is_objArray_klass()) {
700 base = arrayOopDesc::base_offset_in_bytes(T_OBJECT);
701 scale = heapOopSize;
702 } else if (k->is_typeArray_klass()) {
703 TypeArrayKlass* tak = TypeArrayKlass::cast(k);
704 base = tak->array_header_in_bytes();
705 assert(base == arrayOopDesc::base_offset_in_bytes(tak->element_type()), "array_header_size semantics ok");
706 scale = (1 << tak->log2_element_size());
707 } else if (k->is_valueArray_klass()) {
708 ValueArrayKlass* vak = ValueArrayKlass::cast(k);
709 ValueKlass* vklass = vak->element_klass();
710 base = vak->array_header_in_bytes();
711 scale = vak->element_byte_size();
712 } else {
713 ShouldNotReachHere();
714 }
715 }
716
717 UNSAFE_ENTRY(jint, Unsafe_ArrayBaseOffset0(JNIEnv *env, jobject unsafe, jclass clazz)) {
718 int base = 0, scale = 0;
719 getBaseAndScale(base, scale, clazz, CHECK_0);
720
721 return field_offset_from_byte_offset(base);
722 } UNSAFE_END
723
724
725 UNSAFE_ENTRY(jint, Unsafe_ArrayIndexScale0(JNIEnv *env, jobject unsafe, jclass clazz)) {
726 int base = 0, scale = 0;
727 getBaseAndScale(base, scale, clazz, CHECK_0);
728
729 // This VM packs both fields and array elements down to the byte.
730 // But watch out: If this changes, so that array references for
731 // a given primitive type (say, T_BOOLEAN) use different memory units
732 // than fields, this method MUST return zero for such arrays.
733 // For example, the VM used to store sub-word sized fields in full
734 // words in the object layout, so that accessors like getByte(Object,int)
735 // did not really do what one might expect for arrays. Therefore,
736 // this function used to report a zero scale factor, so that the user
737 // would know not to attempt to access sub-word array elements.
738 // // Code for unpacked fields:
739 // if (scale < wordSize) return 0;
740
741 // The following allows for a pretty general fieldOffset cookie scheme,
742 // but requires it to be linear in byte offset.
743 return field_offset_from_byte_offset(scale) - field_offset_from_byte_offset(0);
744 } UNSAFE_END
745
746
747 static inline void throw_new(JNIEnv *env, const char *ename) {
748 jclass cls = env->FindClass(ename);
749 if (env->ExceptionCheck()) {
750 env->ExceptionClear();
751 tty->print_cr("Unsafe: cannot throw %s because FindClass has failed", ename);
752 return;
753 }
754
755 env->ThrowNew(cls, NULL);
756 }
757
758 static jclass Unsafe_DefineClass_impl(JNIEnv *env, jstring name, jbyteArray data, int offset, int length, jobject loader, jobject pd) {
759 // Code lifted from JDK 1.3 ClassLoader.c
760
761 jbyte *body;
762 char *utfName = NULL;
763 jclass result = 0;
764 char buf[128];
765
766 assert(data != NULL, "Class bytes must not be NULL");
767 assert(length >= 0, "length must not be negative: %d", length);
768
769 if (UsePerfData) {
770 ClassLoader::unsafe_defineClassCallCounter()->inc();
771 }
772
773 body = NEW_C_HEAP_ARRAY(jbyte, length, mtInternal);
774 if (body == NULL) {
775 throw_new(env, "java/lang/OutOfMemoryError");
776 return 0;
777 }
778
779 env->GetByteArrayRegion(data, offset, length, body);
780 if (env->ExceptionOccurred()) {
781 goto free_body;
782 }
783
784 if (name != NULL) {
785 uint len = env->GetStringUTFLength(name);
786 int unicode_len = env->GetStringLength(name);
787
788 if (len >= sizeof(buf)) {
789 utfName = NEW_C_HEAP_ARRAY(char, len + 1, mtInternal);
790 if (utfName == NULL) {
791 throw_new(env, "java/lang/OutOfMemoryError");
792 goto free_body;
793 }
794 } else {
795 utfName = buf;
796 }
797
798 env->GetStringUTFRegion(name, 0, unicode_len, utfName);
799
800 for (uint i = 0; i < len; i++) {
801 if (utfName[i] == '.') utfName[i] = '/';
802 }
803 }
804
805 result = JVM_DefineClass(env, utfName, loader, body, length, pd);
806
807 if (utfName && utfName != buf) {
808 FREE_C_HEAP_ARRAY(char, utfName);
809 }
810
811 free_body:
812 FREE_C_HEAP_ARRAY(jbyte, body);
813 return result;
814 }
815
816
817 UNSAFE_ENTRY(jclass, Unsafe_DefineClass0(JNIEnv *env, jobject unsafe, jstring name, jbyteArray data, int offset, int length, jobject loader, jobject pd)) {
818 ThreadToNativeFromVM ttnfv(thread);
819
820 return Unsafe_DefineClass_impl(env, name, data, offset, length, loader, pd);
821 } UNSAFE_END
822
823
824 // define a class but do not make it known to the class loader or system dictionary
825 // - host_class: supplies context for linkage, access control, protection domain, and class loader
826 // if host_class is itself anonymous then it is replaced with its host class.
827 // - data: bytes of a class file, a raw memory address (length gives the number of bytes)
828 // - cp_patches: where non-null entries exist, they replace corresponding CP entries in data
829
830 // When you load an anonymous class U, it works as if you changed its name just before loading,
831 // to a name that you will never use again. Since the name is lost, no other class can directly
832 // link to any member of U. Just after U is loaded, the only way to use it is reflectively,
833 // through java.lang.Class methods like Class.newInstance.
834
835 // The package of an anonymous class must either match its host's class's package or be in the
836 // unnamed package. If it is in the unnamed package then it will be put in its host class's
837 // package.
838 //
839
840 // Access checks for linkage sites within U continue to follow the same rules as for named classes.
841 // An anonymous class also has special privileges to access any member of its host class.
842 // This is the main reason why this loading operation is unsafe. The purpose of this is to
843 // allow language implementations to simulate "open classes"; a host class in effect gets
844 // new code when an anonymous class is loaded alongside it. A less convenient but more
845 // standard way to do this is with reflection, which can also be set to ignore access
846 // restrictions.
847
848 // Access into an anonymous class is possible only through reflection. Therefore, there
849 // are no special access rules for calling into an anonymous class. The relaxed access
850 // rule for the host class is applied in the opposite direction: A host class reflectively
851 // access one of its anonymous classes.
852
853 // If you load the same bytecodes twice, you get two different classes. You can reload
854 // the same bytecodes with or without varying CP patches.
855
856 // By using the CP patching array, you can have a new anonymous class U2 refer to an older one U1.
857 // The bytecodes for U2 should refer to U1 by a symbolic name (doesn't matter what the name is).
858 // The CONSTANT_Class entry for that name can be patched to refer directly to U1.
859
860 // This allows, for example, U2 to use U1 as a superclass or super-interface, or as
861 // an outer class (so that U2 is an anonymous inner class of anonymous U1).
862 // It is not possible for a named class, or an older anonymous class, to refer by
863 // name (via its CP) to a newer anonymous class.
864
865 // CP patching may also be used to modify (i.e., hack) the names of methods, classes,
866 // or type descriptors used in the loaded anonymous class.
867
868 // Finally, CP patching may be used to introduce "live" objects into the constant pool,
869 // instead of "dead" strings. A compiled statement like println((Object)"hello") can
870 // be changed to println(greeting), where greeting is an arbitrary object created before
871 // the anonymous class is loaded. This is useful in dynamic languages, in which
872 // various kinds of metaobjects must be introduced as constants into bytecode.
873 // Note the cast (Object), which tells the verifier to expect an arbitrary object,
874 // not just a literal string. For such ldc instructions, the verifier uses the
875 // type Object instead of String, if the loaded constant is not in fact a String.
876
877 static InstanceKlass*
878 Unsafe_DefineAnonymousClass_impl(JNIEnv *env,
879 jclass host_class, jbyteArray data, jobjectArray cp_patches_jh,
880 u1** temp_alloc,
881 TRAPS) {
882 assert(host_class != NULL, "host_class must not be NULL");
883 assert(data != NULL, "data must not be NULL");
884
885 if (UsePerfData) {
886 ClassLoader::unsafe_defineClassCallCounter()->inc();
887 }
888
889 jint length = typeArrayOop(JNIHandles::resolve_non_null(data))->length();
890 assert(length >= 0, "class_bytes_length must not be negative: %d", length);
891
892 int class_bytes_length = (int) length;
893
894 u1* class_bytes = NEW_C_HEAP_ARRAY(u1, length, mtInternal);
895 if (class_bytes == NULL) {
896 THROW_0(vmSymbols::java_lang_OutOfMemoryError());
897 }
898
899 // caller responsible to free it:
900 *temp_alloc = class_bytes;
901
902 ArrayAccess<>::arraycopy_to_native(arrayOop(JNIHandles::resolve_non_null(data)), typeArrayOopDesc::element_offset<jbyte>(0),
903 reinterpret_cast<jbyte*>(class_bytes), length);
904
905 objArrayHandle cp_patches_h;
906 if (cp_patches_jh != NULL) {
907 oop p = JNIHandles::resolve_non_null(cp_patches_jh);
908 assert(p->is_objArray(), "cp_patches must be an object[]");
909 cp_patches_h = objArrayHandle(THREAD, (objArrayOop)p);
910 }
911
912 const Klass* host_klass = java_lang_Class::as_Klass(JNIHandles::resolve_non_null(host_class));
913
914 // Make sure it's the real host class, not another anonymous class.
915 while (host_klass != NULL && host_klass->is_instance_klass() &&
916 InstanceKlass::cast(host_klass)->is_unsafe_anonymous()) {
917 host_klass = InstanceKlass::cast(host_klass)->unsafe_anonymous_host();
918 }
919
920 // Primitive types have NULL Klass* fields in their java.lang.Class instances.
921 if (host_klass == NULL) {
922 THROW_MSG_0(vmSymbols::java_lang_IllegalArgumentException(), "Host class is null");
923 }
924
925 assert(host_klass->is_instance_klass(), "Host class must be an instance class");
926
927 const char* host_source = host_klass->external_name();
928 Handle host_loader(THREAD, host_klass->class_loader());
929 Handle host_domain(THREAD, host_klass->protection_domain());
930
931 GrowableArray<Handle>* cp_patches = NULL;
932
933 if (cp_patches_h.not_null()) {
934 int alen = cp_patches_h->length();
935
936 for (int i = alen-1; i >= 0; i--) {
937 oop p = cp_patches_h->obj_at(i);
938 if (p != NULL) {
939 Handle patch(THREAD, p);
940
941 if (cp_patches == NULL) {
942 cp_patches = new GrowableArray<Handle>(i+1, i+1, Handle());
943 }
944
945 cp_patches->at_put(i, patch);
946 }
947 }
948 }
949
950 ClassFileStream st(class_bytes, class_bytes_length, host_source, ClassFileStream::verify);
951
952 Symbol* no_class_name = NULL;
953 Klass* anonk = SystemDictionary::parse_stream(no_class_name,
954 host_loader,
955 host_domain,
956 &st,
957 InstanceKlass::cast(host_klass),
958 cp_patches,
959 CHECK_NULL);
960 if (anonk == NULL) {
961 return NULL;
962 }
963
964 return InstanceKlass::cast(anonk);
965 }
966
967 UNSAFE_ENTRY(jclass, Unsafe_DefineAnonymousClass0(JNIEnv *env, jobject unsafe, jclass host_class, jbyteArray data, jobjectArray cp_patches_jh)) {
968 ResourceMark rm(THREAD);
969
970 jobject res_jh = NULL;
971 u1* temp_alloc = NULL;
972
973 InstanceKlass* anon_klass = Unsafe_DefineAnonymousClass_impl(env, host_class, data, cp_patches_jh, &temp_alloc, THREAD);
974 if (anon_klass != NULL) {
975 res_jh = JNIHandles::make_local(env, anon_klass->java_mirror());
976 }
977
978 // try/finally clause:
979 if (temp_alloc != NULL) {
980 FREE_C_HEAP_ARRAY(u1, temp_alloc);
981 }
982
983 // The anonymous class loader data has been artificially been kept alive to
984 // this point. The mirror and any instances of this class have to keep
985 // it alive afterwards.
986 if (anon_klass != NULL) {
987 anon_klass->class_loader_data()->dec_keep_alive();
988 }
989
990 // let caller initialize it as needed...
991
992 return (jclass) res_jh;
993 } UNSAFE_END
994
995
996
997 UNSAFE_ENTRY(void, Unsafe_ThrowException(JNIEnv *env, jobject unsafe, jthrowable thr)) {
998 ThreadToNativeFromVM ttnfv(thread);
999 env->Throw(thr);
1000 } UNSAFE_END
1001
1002 // JSR166 ------------------------------------------------------------------
1003
1004 UNSAFE_ENTRY(jobject, Unsafe_CompareAndExchangeReference(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jobject e_h, jobject x_h)) {
1005 oop x = JNIHandles::resolve(x_h);
1006 oop e = JNIHandles::resolve(e_h);
1007 oop p = JNIHandles::resolve(obj);
1008 assert_field_offset_sane(p, offset);
1009 oop res = HeapAccess<ON_UNKNOWN_OOP_REF>::oop_atomic_cmpxchg_at(x, p, (ptrdiff_t)offset, e);
1010 return JNIHandles::make_local(env, res);
1011 } UNSAFE_END
1012
1013 UNSAFE_ENTRY(jint, Unsafe_CompareAndExchangeInt(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jint e, jint x)) {
1014 oop p = JNIHandles::resolve(obj);
1015 if (p == NULL) {
1016 volatile jint* addr = (volatile jint*)index_oop_from_field_offset_long(p, offset);
1017 return RawAccess<>::atomic_cmpxchg(x, addr, e);
1018 } else {
1019 assert_field_offset_sane(p, offset);
1020 return HeapAccess<>::atomic_cmpxchg_at(x, p, (ptrdiff_t)offset, e);
1021 }
1022 } UNSAFE_END
1023
1024 UNSAFE_ENTRY(jlong, Unsafe_CompareAndExchangeLong(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jlong e, jlong x)) {
1025 oop p = JNIHandles::resolve(obj);
1026 if (p == NULL) {
1027 volatile jlong* addr = (volatile jlong*)index_oop_from_field_offset_long(p, offset);
1028 return RawAccess<>::atomic_cmpxchg(x, addr, e);
1029 } else {
1030 assert_field_offset_sane(p, offset);
1031 return HeapAccess<>::atomic_cmpxchg_at(x, p, (ptrdiff_t)offset, e);
1032 }
1033 } UNSAFE_END
1034
1035 UNSAFE_ENTRY(jboolean, Unsafe_CompareAndSetReference(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jobject e_h, jobject x_h)) {
1036 oop x = JNIHandles::resolve(x_h);
1037 oop e = JNIHandles::resolve(e_h);
1038 oop p = JNIHandles::resolve(obj);
1039 assert_field_offset_sane(p, offset);
1040 oop ret = HeapAccess<ON_UNKNOWN_OOP_REF>::oop_atomic_cmpxchg_at(x, p, (ptrdiff_t)offset, e);
1041 return oopDesc::equals(ret, e);
1042 } UNSAFE_END
1043
1044 UNSAFE_ENTRY(jboolean, Unsafe_CompareAndSetInt(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jint e, jint x)) {
1045 oop p = JNIHandles::resolve(obj);
1046 if (p == NULL) {
1047 volatile jint* addr = (volatile jint*)index_oop_from_field_offset_long(p, offset);
1048 return RawAccess<>::atomic_cmpxchg(x, addr, e) == e;
1049 } else {
1050 assert_field_offset_sane(p, offset);
1051 return HeapAccess<>::atomic_cmpxchg_at(x, p, (ptrdiff_t)offset, e) == e;
1052 }
1053 } UNSAFE_END
1054
1055 UNSAFE_ENTRY(jboolean, Unsafe_CompareAndSetLong(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jlong e, jlong x)) {
1056 oop p = JNIHandles::resolve(obj);
1057 if (p == NULL) {
1058 volatile jlong* addr = (volatile jlong*)index_oop_from_field_offset_long(p, offset);
1059 return RawAccess<>::atomic_cmpxchg(x, addr, e) == e;
1060 } else {
1061 assert_field_offset_sane(p, offset);
1062 return HeapAccess<>::atomic_cmpxchg_at(x, p, (ptrdiff_t)offset, e) == e;
1063 }
1064 } UNSAFE_END
1065
1066 static void post_thread_park_event(EventThreadPark* event, const oop obj, jlong timeout_nanos, jlong until_epoch_millis) {
1067 assert(event != NULL, "invariant");
1068 assert(event->should_commit(), "invariant");
1069 event->set_parkedClass((obj != NULL) ? obj->klass() : NULL);
1070 event->set_timeout(timeout_nanos);
1071 event->set_until(until_epoch_millis);
1072 event->set_address((obj != NULL) ? (u8)cast_from_oop<uintptr_t>(obj) : 0);
1073 event->commit();
1074 }
1075
1076 UNSAFE_ENTRY(void, Unsafe_Park(JNIEnv *env, jobject unsafe, jboolean isAbsolute, jlong time)) {
1077 HOTSPOT_THREAD_PARK_BEGIN((uintptr_t) thread->parker(), (int) isAbsolute, time);
1078 EventThreadPark event;
1079
1080 JavaThreadParkedState jtps(thread, time != 0);
1081 thread->parker()->park(isAbsolute != 0, time);
1082 if (event.should_commit()) {
1083 const oop obj = thread->current_park_blocker();
1084 if (time == 0) {
1085 post_thread_park_event(&event, obj, min_jlong, min_jlong);
1086 } else {
1087 if (isAbsolute != 0) {
1088 post_thread_park_event(&event, obj, min_jlong, time);
1089 } else {
1090 post_thread_park_event(&event, obj, time, min_jlong);
1091 }
1092 }
1093 }
1094 HOTSPOT_THREAD_PARK_END((uintptr_t) thread->parker());
1095 } UNSAFE_END
1096
1097 UNSAFE_ENTRY(void, Unsafe_Unpark(JNIEnv *env, jobject unsafe, jobject jthread)) {
1098 Parker* p = NULL;
1099
1100 if (jthread != NULL) {
1101 ThreadsListHandle tlh;
1102 JavaThread* thr = NULL;
1103 oop java_thread = NULL;
1104 (void) tlh.cv_internal_thread_to_JavaThread(jthread, &thr, &java_thread);
1105 if (java_thread != NULL) {
1106 // This is a valid oop.
1107 jlong lp = java_lang_Thread::park_event(java_thread);
1108 if (lp != 0) {
1109 // This cast is OK even though the jlong might have been read
1110 // non-atomically on 32bit systems, since there, one word will
1111 // always be zero anyway and the value set is always the same
1112 p = (Parker*)addr_from_java(lp);
1113 } else {
1114 // Not cached in the java.lang.Thread oop yet (could be an
1115 // older version of library).
1116 if (thr != NULL) {
1117 // The JavaThread is alive.
1118 p = thr->parker();
1119 if (p != NULL) {
1120 // Cache the Parker in the java.lang.Thread oop for next time.
1121 java_lang_Thread::set_park_event(java_thread, addr_to_java(p));
1122 }
1123 }
1124 }
1125 }
1126 } // ThreadsListHandle is destroyed here.
1127
1128 if (p != NULL) {
1129 HOTSPOT_THREAD_UNPARK((uintptr_t) p);
1130 p->unpark();
1131 }
1132 } UNSAFE_END
1133
1134 UNSAFE_ENTRY(jint, Unsafe_GetLoadAverage0(JNIEnv *env, jobject unsafe, jdoubleArray loadavg, jint nelem)) {
1135 const int max_nelem = 3;
1136 double la[max_nelem];
1137 jint ret;
1138
1139 typeArrayOop a = typeArrayOop(JNIHandles::resolve_non_null(loadavg));
1140 assert(a->is_typeArray(), "must be type array");
1141
1142 ret = os::loadavg(la, nelem);
1143 if (ret == -1) {
1144 return -1;
1145 }
1146
1147 // if successful, ret is the number of samples actually retrieved.
1148 assert(ret >= 0 && ret <= max_nelem, "Unexpected loadavg return value");
1149 switch(ret) {
1150 case 3: a->double_at_put(2, (jdouble)la[2]); // fall through
1151 case 2: a->double_at_put(1, (jdouble)la[1]); // fall through
1152 case 1: a->double_at_put(0, (jdouble)la[0]); break;
1153 }
1154
1155 return ret;
1156 } UNSAFE_END
1157
1158
1159 /// JVM_RegisterUnsafeMethods
1160
1161 #define ADR "J"
1162
1163 #define LANG "Ljava/lang/"
1164
1165 #define OBJ LANG "Object;"
1166 #define CLS LANG "Class;"
1167 #define FLD LANG "reflect/Field;"
1168 #define THR LANG "Throwable;"
1169
1170 #define DC_Args LANG "String;[BII" LANG "ClassLoader;" "Ljava/security/ProtectionDomain;"
1171 #define DAC_Args CLS "[B[" OBJ
1172
1173 #define CC (char*) /*cast a literal from (const char*)*/
1174 #define FN_PTR(f) CAST_FROM_FN_PTR(void*, &f)
1175
1176 #define DECLARE_GETPUTOOP(Type, Desc) \
1177 {CC "get" #Type, CC "(" OBJ "J)" #Desc, FN_PTR(Unsafe_Get##Type)}, \
1178 {CC "put" #Type, CC "(" OBJ "J" #Desc ")V", FN_PTR(Unsafe_Put##Type)}, \
1179 {CC "get" #Type "Volatile", CC "(" OBJ "J)" #Desc, FN_PTR(Unsafe_Get##Type##Volatile)}, \
1180 {CC "put" #Type "Volatile", CC "(" OBJ "J" #Desc ")V", FN_PTR(Unsafe_Put##Type##Volatile)}
1181
1182
1183 static JNINativeMethod jdk_internal_misc_Unsafe_methods[] = {
1184 {CC "getReference", CC "(" OBJ "J)" OBJ "", FN_PTR(Unsafe_GetReference)},
1185 {CC "putReference", CC "(" OBJ "J" OBJ ")V", FN_PTR(Unsafe_PutReference)},
1186 {CC "getReferenceVolatile", CC "(" OBJ "J)" OBJ, FN_PTR(Unsafe_GetReferenceVolatile)},
1187 {CC "putReferenceVolatile", CC "(" OBJ "J" OBJ ")V", FN_PTR(Unsafe_PutReferenceVolatile)},
1188
1189 {CC "isFlattenedArray", CC "(" CLS ")Z", FN_PTR(Unsafe_IsFlattenedArray)},
1190 {CC "getValue", CC "(" OBJ "J" CLS ")" OBJ, FN_PTR(Unsafe_GetValue)},
1191 {CC "putValue", CC "(" OBJ "J" CLS OBJ ")V", FN_PTR(Unsafe_PutValue)},
1192 {CC "uninitializedDefaultValue", CC "(" CLS ")" OBJ, FN_PTR(Unsafe_UninitializedDefaultValue)},
1193 {CC "makePrivateBuffer", CC "(" OBJ ")" OBJ, FN_PTR(Unsafe_MakePrivateBuffer)},
1194 {CC "finishPrivateBuffer", CC "(" OBJ ")" OBJ, FN_PTR(Unsafe_FinishPrivateBuffer)},
1195 {CC "valueHeaderSize", CC "(" CLS ")J", FN_PTR(Unsafe_ValueHeaderSize)},
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 "compareAndSetReference",CC "(" OBJ "J" OBJ "" OBJ ")Z", FN_PTR(Unsafe_CompareAndSetReference)},
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 "compareAndExchangeReference", CC "(" OBJ "J" OBJ "" OBJ ")" OBJ, FN_PTR(Unsafe_CompareAndExchangeReference)},
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