1 /*
2 * Copyright (c) 2000, 2017, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "precompiled.hpp"
26 #include "jni.h"
27 #include "jvm.h"
28 #include "classfile/classFileStream.hpp"
29 #include "classfile/vmSymbols.hpp"
30 #include "memory/allocation.inline.hpp"
31 #include "memory/resourceArea.hpp"
32 #include "oops/fieldStreams.hpp"
33 #include "oops/objArrayOop.inline.hpp"
34 #include "oops/oop.inline.hpp"
35 #include "prims/unsafe.hpp"
36 #include "runtime/atomic.hpp"
37 #include "runtime/globals.hpp"
38 #include "runtime/interfaceSupport.hpp"
39 #include "runtime/orderAccess.inline.hpp"
40 #include "runtime/reflection.hpp"
41 #include "runtime/vm_version.hpp"
42 #include "services/threadService.hpp"
43 #include "trace/tracing.hpp"
44 #include "utilities/align.hpp"
45 #include "utilities/copy.hpp"
46 #include "utilities/dtrace.hpp"
47 #include "utilities/macros.hpp"
48 #if INCLUDE_ALL_GCS
49 #include "gc/g1/g1SATBCardTableModRefBS.hpp"
50 #endif // INCLUDE_ALL_GCS
51
52 /**
53 * Implementation of the jdk.internal.misc.Unsafe class
54 */
55
56
57 #define MAX_OBJECT_SIZE \
58 ( arrayOopDesc::header_size(T_DOUBLE) * HeapWordSize \
59 + ((julong)max_jint * sizeof(double)) )
60
61 #define UNSAFE_ENTRY(result_type, header) \
62 JVM_ENTRY(static result_type, header)
63
64 #define UNSAFE_ACCESS_ENTRY(result_type, header) \
65 JVM_ENTRY(static result_type, header) \
66 thread->set_doing_unsafe_access(true);
67
68 #define UNSAFE_LEAF(result_type, header) \
69 JVM_LEAF(static result_type, header)
70
71 #define UNSAFE_ACCESS_LEAF(result_type, header) \
72 JVM_LEAF(static result_type, header) \
73 JavaThread* thread=JavaThread::thread_from_jni_environment(env); \
74 thread->set_doing_unsafe_access(true);
75
76 #define UNSAFE_ACCESS_END \
77 thread->set_doing_unsafe_access(false); \
78 JVM_END
79
80 #define UNSAFE_END JVM_END
81
82 static inline void* addr_from_java(jlong addr) {
83 // This assert fails in a variety of ways on 32-bit systems.
84 // It is impossible to predict whether native code that converts
85 // pointers to longs will sign-extend or zero-extend the addresses.
86 //assert(addr == (uintptr_t)addr, "must not be odd high bits");
87 return (void*)(uintptr_t)addr;
88 }
89
90 static inline jlong addr_to_java(void* p) {
91 assert(p == (void*)(uintptr_t)p, "must not be odd high bits");
92 return (uintptr_t)p;
93 }
94
95
96 // Note: The VM's obj_field and related accessors use byte-scaled
97 // ("unscaled") offsets, just as the unsafe methods do.
98
99 // However, the method Unsafe.fieldOffset explicitly declines to
100 // guarantee this. The field offset values manipulated by the Java user
101 // through the Unsafe API are opaque cookies that just happen to be byte
102 // offsets. We represent this state of affairs by passing the cookies
103 // through conversion functions when going between the VM and the Unsafe API.
104 // The conversion functions just happen to be no-ops at present.
105
106 static inline jlong field_offset_to_byte_offset(jlong field_offset) {
107 return field_offset;
108 }
109
110 static inline jlong field_offset_from_byte_offset(jlong byte_offset) {
111 return byte_offset;
112 }
113
114 static inline void* index_oop_from_field_offset_long(oop p, jlong field_offset) {
115 jlong byte_offset = field_offset_to_byte_offset(field_offset);
116
117 #ifdef ASSERT
118 if (p != NULL) {
119 assert(byte_offset >= 0 && byte_offset <= (jlong)MAX_OBJECT_SIZE, "sane offset");
120 if (byte_offset == (jint)byte_offset) {
121 void* ptr_plus_disp = (address)p + byte_offset;
122 assert((void*)p->obj_field_addr<oop>((jint)byte_offset) == ptr_plus_disp,
123 "raw [ptr+disp] must be consistent with oop::field_base");
124 }
125 jlong p_size = HeapWordSize * (jlong)(p->size());
126 assert(byte_offset < p_size, "Unsafe access: offset " INT64_FORMAT " > object's size " INT64_FORMAT, (int64_t)byte_offset, (int64_t)p_size);
127 }
128 #endif
129
130 if (sizeof(char*) == sizeof(jint)) { // (this constant folds!)
131 return (address)p + (jint) byte_offset;
132 } else {
133 return (address)p + byte_offset;
134 }
135 }
136
137 // Externally callable versions:
138 // (Use these in compiler intrinsics which emulate unsafe primitives.)
139 jlong Unsafe_field_offset_to_byte_offset(jlong field_offset) {
140 return field_offset;
141 }
142 jlong Unsafe_field_offset_from_byte_offset(jlong byte_offset) {
143 return byte_offset;
144 }
145
146
147 ///// Data read/writes on the Java heap and in native (off-heap) memory
148
149 /**
150 * Helper class for accessing memory.
151 *
152 * Normalizes values and wraps accesses in
153 * JavaThread::doing_unsafe_access() if needed.
154 */
155 class MemoryAccess : StackObj {
156 JavaThread* _thread;
157 jobject _obj;
158 jlong _offset;
159
160 // Resolves and returns the address of the memory access
161 void* addr() {
162 return index_oop_from_field_offset_long(JNIHandles::resolve(_obj), _offset);
163 }
164
165 template <typename T>
166 T normalize_for_write(T x) {
167 return x;
168 }
169
170 jboolean normalize_for_write(jboolean x) {
171 return x & 1;
172 }
173
174 template <typename T>
175 T normalize_for_read(T x) {
176 return x;
177 }
178
179 jboolean normalize_for_read(jboolean x) {
180 return x != 0;
181 }
182
183 /**
184 * Helper class to wrap memory accesses in JavaThread::doing_unsafe_access()
185 */
186 class GuardUnsafeAccess {
187 JavaThread* _thread;
188 bool _active;
189
190 public:
191 GuardUnsafeAccess(JavaThread* thread, jobject _obj) : _thread(thread) {
192 if (JNIHandles::resolve(_obj) == NULL) {
193 // native/off-heap access which may raise SIGBUS if accessing
194 // memory mapped file data in a region of the file which has
195 // been truncated and is now invalid
196 _thread->set_doing_unsafe_access(true);
197 _active = true;
198 } else {
199 _active = false;
200 }
201 }
202
203 ~GuardUnsafeAccess() {
204 if (_active) {
205 _thread->set_doing_unsafe_access(false);
206 }
207 }
208 };
209
210 public:
211 MemoryAccess(JavaThread* thread, jobject obj, jlong offset)
212 : _thread(thread), _obj(obj), _offset(offset) {
213 }
214
215 template <typename T>
216 T get() {
217 GuardUnsafeAccess guard(_thread, _obj);
218
219 T* p = (T*)addr();
220
221 T x = normalize_for_read(*p);
222
223 return x;
224 }
225
226 template <typename T>
227 void put(T x) {
228 GuardUnsafeAccess guard(_thread, _obj);
229
230 T* p = (T*)addr();
231
232 *p = normalize_for_write(x);
233 }
234
235
236 template <typename T>
237 T get_volatile() {
238 GuardUnsafeAccess guard(_thread, _obj);
239
240 T* p = (T*)addr();
241
242 if (support_IRIW_for_not_multiple_copy_atomic_cpu) {
243 OrderAccess::fence();
244 }
245
246 T x = OrderAccess::load_acquire((volatile T*)p);
247
248 return normalize_for_read(x);
249 }
250
251 template <typename T>
252 void put_volatile(T x) {
253 GuardUnsafeAccess guard(_thread, _obj);
254
255 T* p = (T*)addr();
256
257 OrderAccess::release_store_fence((volatile T*)p, normalize_for_write(x));
258 }
259
260
261 #ifndef SUPPORTS_NATIVE_CX8
262 jlong get_jlong_locked() {
263 GuardUnsafeAccess guard(_thread, _obj);
264
265 MutexLockerEx mu(UnsafeJlong_lock, Mutex::_no_safepoint_check_flag);
266
267 jlong* p = (jlong*)addr();
268
269 jlong x = Atomic::load(p);
270
271 return x;
272 }
273
274 void put_jlong_locked(jlong x) {
275 GuardUnsafeAccess guard(_thread, _obj);
276
277 MutexLockerEx mu(UnsafeJlong_lock, Mutex::_no_safepoint_check_flag);
278
279 jlong* p = (jlong*)addr();
280
281 Atomic::store(normalize_for_write(x), p);
282 }
283 #endif
284 };
285
286 // Get/PutObject must be special-cased, since it works with handles.
287
288 // We could be accessing the referent field in a reference
289 // object. If G1 is enabled then we need to register non-null
290 // referent with the SATB barrier.
291
292 #if INCLUDE_ALL_GCS
293 static bool is_java_lang_ref_Reference_access(oop o, jlong offset) {
294 if (offset == java_lang_ref_Reference::referent_offset && o != NULL) {
295 Klass* k = o->klass();
296 if (InstanceKlass::cast(k)->reference_type() != REF_NONE) {
297 assert(InstanceKlass::cast(k)->is_subclass_of(SystemDictionary::Reference_klass()), "sanity");
298 return true;
299 }
300 }
301 return false;
302 }
303 #endif
304
305 static void ensure_satb_referent_alive(oop o, jlong offset, oop v) {
306 #if INCLUDE_ALL_GCS
307 if (UseG1GC && v != NULL && is_java_lang_ref_Reference_access(o, offset)) {
308 G1SATBCardTableModRefBS::enqueue(v);
309 }
310 #endif
311 }
312
313 // These functions allow a null base pointer with an arbitrary address.
314 // But if the base pointer is non-null, the offset should make some sense.
315 // That is, it should be in the range [0, MAX_OBJECT_SIZE].
316 UNSAFE_ENTRY(jobject, Unsafe_GetObject(JNIEnv *env, jobject unsafe, jobject obj, jlong offset)) {
317 oop p = JNIHandles::resolve(obj);
318 oop v;
319
320 if (UseCompressedOops) {
321 narrowOop n = *(narrowOop*)index_oop_from_field_offset_long(p, offset);
322 v = oopDesc::decode_heap_oop(n);
323 } else {
324 v = *(oop*)index_oop_from_field_offset_long(p, offset);
325 }
326
327 ensure_satb_referent_alive(p, offset, v);
328
329 return JNIHandles::make_local(env, v);
330 } UNSAFE_END
331
332 UNSAFE_ENTRY(void, Unsafe_PutObject(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jobject x_h)) {
333 oop x = JNIHandles::resolve(x_h);
334 oop p = JNIHandles::resolve(obj);
335
336 if (UseCompressedOops) {
337 oop_store((narrowOop*)index_oop_from_field_offset_long(p, offset), x);
338 } else {
339 oop_store((oop*)index_oop_from_field_offset_long(p, offset), x);
340 }
341 } UNSAFE_END
342
343 UNSAFE_ENTRY(jobject, Unsafe_GetObjectVolatile(JNIEnv *env, jobject unsafe, jobject obj, jlong offset)) {
344 oop p = JNIHandles::resolve(obj);
345 void* addr = index_oop_from_field_offset_long(p, offset);
346
347 volatile oop v;
348
349 if (support_IRIW_for_not_multiple_copy_atomic_cpu) {
350 OrderAccess::fence();
351 }
352
353 if (UseCompressedOops) {
354 volatile narrowOop n = *(volatile narrowOop*) addr;
355 (void)const_cast<oop&>(v = oopDesc::decode_heap_oop(n));
356 } else {
357 (void)const_cast<oop&>(v = *(volatile oop*) addr);
358 }
359
360 ensure_satb_referent_alive(p, offset, v);
361
362 OrderAccess::acquire();
363 return JNIHandles::make_local(env, v);
364 } UNSAFE_END
365
366 UNSAFE_ENTRY(void, Unsafe_PutObjectVolatile(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jobject x_h)) {
367 oop x = JNIHandles::resolve(x_h);
368 oop p = JNIHandles::resolve(obj);
369 void* addr = index_oop_from_field_offset_long(p, offset);
370 OrderAccess::release();
371
372 if (UseCompressedOops) {
373 oop_store((narrowOop*)addr, x);
374 } else {
375 oop_store((oop*)addr, x);
376 }
377
378 OrderAccess::fence();
379 } UNSAFE_END
380
381 UNSAFE_ENTRY(jobject, Unsafe_GetUncompressedObject(JNIEnv *env, jobject unsafe, jlong addr)) {
382 oop v = *(oop*) (address) addr;
383
384 return JNIHandles::make_local(env, v);
385 } UNSAFE_END
386
387 #ifndef SUPPORTS_NATIVE_CX8
388
389 // VM_Version::supports_cx8() is a surrogate for 'supports atomic long memory ops'.
390 //
391 // On platforms which do not support atomic compare-and-swap of jlong (8 byte)
392 // values we have to use a lock-based scheme to enforce atomicity. This has to be
393 // applied to all Unsafe operations that set the value of a jlong field. Even so
394 // the compareAndSetLong operation will not be atomic with respect to direct stores
395 // to the field from Java code. It is important therefore that any Java code that
396 // utilizes these Unsafe jlong operations does not perform direct stores. To permit
397 // direct loads of the field from Java code we must also use Atomic::store within the
398 // locked regions. And for good measure, in case there are direct stores, we also
399 // employ Atomic::load within those regions. Note that the field in question must be
400 // volatile and so must have atomic load/store accesses applied at the Java level.
401 //
402 // The locking scheme could utilize a range of strategies for controlling the locking
403 // granularity: from a lock per-field through to a single global lock. The latter is
404 // the simplest and is used for the current implementation. Note that the Java object
405 // that contains the field, can not, in general, be used for locking. To do so can lead
406 // to deadlocks as we may introduce locking into what appears to the Java code to be a
407 // lock-free path.
408 //
409 // As all the locked-regions are very short and themselves non-blocking we can treat
410 // them as leaf routines and elide safepoint checks (ie we don't perform any thread
411 // state transitions even when blocking for the lock). Note that if we do choose to
412 // add safepoint checks and thread state transitions, we must ensure that we calculate
413 // the address of the field _after_ we have acquired the lock, else the object may have
414 // been moved by the GC
415
416 UNSAFE_ENTRY(jlong, Unsafe_GetLongVolatile(JNIEnv *env, jobject unsafe, jobject obj, jlong offset)) {
417 if (VM_Version::supports_cx8()) {
418 return MemoryAccess(thread, obj, offset).get_volatile<jlong>();
419 } else {
420 return MemoryAccess(thread, obj, offset).get_jlong_locked();
421 }
422 } UNSAFE_END
423
424 UNSAFE_ENTRY(void, Unsafe_PutLongVolatile(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jlong x)) {
425 if (VM_Version::supports_cx8()) {
426 MemoryAccess(thread, obj, offset).put_volatile<jlong>(x);
427 } else {
428 MemoryAccess(thread, obj, offset).put_jlong_locked(x);
429 }
430 } UNSAFE_END
431
432 #endif // not SUPPORTS_NATIVE_CX8
433
434 UNSAFE_LEAF(jboolean, Unsafe_isBigEndian0(JNIEnv *env, jobject unsafe)) {
435 #ifdef VM_LITTLE_ENDIAN
436 return false;
437 #else
438 return true;
439 #endif
440 } UNSAFE_END
441
442 UNSAFE_LEAF(jint, Unsafe_unalignedAccess0(JNIEnv *env, jobject unsafe)) {
443 return UseUnalignedAccesses;
444 } UNSAFE_END
445
446 #define DEFINE_GETSETOOP(java_type, Type) \
447 \
448 UNSAFE_ENTRY(java_type, Unsafe_Get##Type(JNIEnv *env, jobject unsafe, jobject obj, jlong offset)) { \
449 return MemoryAccess(thread, obj, offset).get<java_type>(); \
450 } UNSAFE_END \
451 \
452 UNSAFE_ENTRY(void, Unsafe_Put##Type(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, java_type x)) { \
453 MemoryAccess(thread, obj, offset).put<java_type>(x); \
454 } UNSAFE_END \
455 \
456 // END DEFINE_GETSETOOP.
457
458 DEFINE_GETSETOOP(jboolean, Boolean)
459 DEFINE_GETSETOOP(jbyte, Byte)
460 DEFINE_GETSETOOP(jshort, Short);
461 DEFINE_GETSETOOP(jchar, Char);
462 DEFINE_GETSETOOP(jint, Int);
463 DEFINE_GETSETOOP(jlong, Long);
464 DEFINE_GETSETOOP(jfloat, Float);
465 DEFINE_GETSETOOP(jdouble, Double);
466
467 #undef DEFINE_GETSETOOP
468
469 #define DEFINE_GETSETOOP_VOLATILE(java_type, Type) \
470 \
471 UNSAFE_ENTRY(java_type, Unsafe_Get##Type##Volatile(JNIEnv *env, jobject unsafe, jobject obj, jlong offset)) { \
472 return MemoryAccess(thread, obj, offset).get_volatile<java_type>(); \
473 } UNSAFE_END \
474 \
475 UNSAFE_ENTRY(void, Unsafe_Put##Type##Volatile(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, java_type x)) { \
476 MemoryAccess(thread, obj, offset).put_volatile<java_type>(x); \
477 } UNSAFE_END \
478 \
479 // END DEFINE_GETSETOOP_VOLATILE.
480
481 DEFINE_GETSETOOP_VOLATILE(jboolean, Boolean)
482 DEFINE_GETSETOOP_VOLATILE(jbyte, Byte)
483 DEFINE_GETSETOOP_VOLATILE(jshort, Short);
484 DEFINE_GETSETOOP_VOLATILE(jchar, Char);
485 DEFINE_GETSETOOP_VOLATILE(jint, Int);
486 DEFINE_GETSETOOP_VOLATILE(jfloat, Float);
487 DEFINE_GETSETOOP_VOLATILE(jdouble, Double);
488
489 #ifdef SUPPORTS_NATIVE_CX8
490 DEFINE_GETSETOOP_VOLATILE(jlong, Long);
491 #endif
492
493 #undef DEFINE_GETSETOOP_VOLATILE
494
495 UNSAFE_LEAF(void, Unsafe_LoadFence(JNIEnv *env, jobject unsafe)) {
496 OrderAccess::acquire();
497 } UNSAFE_END
498
499 UNSAFE_LEAF(void, Unsafe_StoreFence(JNIEnv *env, jobject unsafe)) {
500 OrderAccess::release();
501 } UNSAFE_END
502
503 UNSAFE_LEAF(void, Unsafe_FullFence(JNIEnv *env, jobject unsafe)) {
504 OrderAccess::fence();
505 } UNSAFE_END
506
507 ////// Allocation requests
508
509 UNSAFE_ENTRY(jobject, Unsafe_AllocateInstance(JNIEnv *env, jobject unsafe, jclass cls)) {
510 ThreadToNativeFromVM ttnfv(thread);
511 return env->AllocObject(cls);
512 } UNSAFE_END
513
514 UNSAFE_ENTRY(jlong, Unsafe_AllocateMemory0(JNIEnv *env, jobject unsafe, jlong size)) {
515 size_t sz = (size_t)size;
516
517 sz = align_up(sz, HeapWordSize);
518 void* x = os::malloc(sz, mtInternal);
519
520 return addr_to_java(x);
521 } UNSAFE_END
522
523 UNSAFE_ENTRY(jlong, Unsafe_ReallocateMemory0(JNIEnv *env, jobject unsafe, jlong addr, jlong size)) {
524 void* p = addr_from_java(addr);
525 size_t sz = (size_t)size;
526 sz = align_up(sz, HeapWordSize);
527
528 void* x = os::realloc(p, sz, mtInternal);
529
530 return addr_to_java(x);
531 } UNSAFE_END
532
533 UNSAFE_ENTRY(void, Unsafe_FreeMemory0(JNIEnv *env, jobject unsafe, jlong addr)) {
534 void* p = addr_from_java(addr);
535
536 os::free(p);
537 } UNSAFE_END
538
539 UNSAFE_ACCESS_ENTRY(void, Unsafe_SetMemory0(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jlong size, jbyte value)) {
540 size_t sz = (size_t)size;
541
542 oop base = JNIHandles::resolve(obj);
543 void* p = index_oop_from_field_offset_long(base, offset);
544
545 Copy::fill_to_memory_atomic(p, sz, value);
546 } UNSAFE_ACCESS_END
547
548 UNSAFE_ACCESS_ENTRY(void, Unsafe_CopyMemory0(JNIEnv *env, jobject unsafe, jobject srcObj, jlong srcOffset, jobject dstObj, jlong dstOffset, jlong size)) {
549 size_t sz = (size_t)size;
550
551 oop srcp = JNIHandles::resolve(srcObj);
552 oop dstp = JNIHandles::resolve(dstObj);
553
554 void* src = index_oop_from_field_offset_long(srcp, srcOffset);
555 void* dst = index_oop_from_field_offset_long(dstp, dstOffset);
556
557 Copy::conjoint_memory_atomic(src, dst, sz);
558 } UNSAFE_ACCESS_END
559
560 // This function is a leaf since if the source and destination are both in native memory
561 // the copy may potentially be very large, and we don't want to disable GC if we can avoid it.
562 // If either source or destination (or both) are on the heap, the function will enter VM using
563 // JVM_ENTRY_FROM_LEAF
564 UNSAFE_ACCESS_LEAF(void, Unsafe_CopySwapMemory0(JNIEnv *env, jobject unsafe, jobject srcObj, jlong srcOffset, jobject dstObj, jlong dstOffset, jlong size, jlong elemSize)) {
565 size_t sz = (size_t)size;
566 size_t esz = (size_t)elemSize;
567
568 if (srcObj == NULL && dstObj == NULL) {
569 // Both src & dst are in native memory
570 address src = (address)srcOffset;
571 address dst = (address)dstOffset;
572
573 Copy::conjoint_swap(src, dst, sz, esz);
574 } else {
575 // At least one of src/dst are on heap, transition to VM to access raw pointers
576
577 JVM_ENTRY_FROM_LEAF(env, void, Unsafe_CopySwapMemory0) {
578 oop srcp = JNIHandles::resolve(srcObj);
579 oop dstp = JNIHandles::resolve(dstObj);
580
581 address src = (address)index_oop_from_field_offset_long(srcp, srcOffset);
582 address dst = (address)index_oop_from_field_offset_long(dstp, dstOffset);
583
584 Copy::conjoint_swap(src, dst, sz, esz);
585 } JVM_END
586 }
587 } UNSAFE_ACCESS_END
588
589 ////// Random queries
590
591 UNSAFE_LEAF(jint, Unsafe_AddressSize0(JNIEnv *env, jobject unsafe)) {
592 return sizeof(void*);
593 } UNSAFE_END
594
595 UNSAFE_LEAF(jint, Unsafe_PageSize()) {
596 return os::vm_page_size();
597 } UNSAFE_END
598
599 static jlong find_field_offset(jclass clazz, jstring name, TRAPS) {
600 assert(clazz != NULL, "clazz must not be NULL");
601 assert(name != NULL, "name must not be NULL");
602
603 ResourceMark rm(THREAD);
604 char *utf_name = java_lang_String::as_utf8_string(JNIHandles::resolve_non_null(name));
605
606 InstanceKlass* k = InstanceKlass::cast(java_lang_Class::as_Klass(JNIHandles::resolve_non_null(clazz)));
607
608 jint offset = -1;
609 for (JavaFieldStream fs(k); !fs.done(); fs.next()) {
610 Symbol *name = fs.name();
611 if (name->equals(utf_name)) {
612 offset = fs.offset();
613 break;
614 }
615 }
616 if (offset < 0) {
617 THROW_0(vmSymbols::java_lang_InternalError());
618 }
619 return field_offset_from_byte_offset(offset);
620 }
621
622 static jlong find_field_offset(jobject field, int must_be_static, TRAPS) {
623 assert(field != NULL, "field must not be NULL");
624
625 oop reflected = JNIHandles::resolve_non_null(field);
626 oop mirror = java_lang_reflect_Field::clazz(reflected);
627 Klass* k = java_lang_Class::as_Klass(mirror);
628 int slot = java_lang_reflect_Field::slot(reflected);
629 int modifiers = java_lang_reflect_Field::modifiers(reflected);
630
631 if (must_be_static >= 0) {
632 int really_is_static = ((modifiers & JVM_ACC_STATIC) != 0);
633 if (must_be_static != really_is_static) {
634 THROW_0(vmSymbols::java_lang_IllegalArgumentException());
635 }
636 }
637
638 int offset = InstanceKlass::cast(k)->field_offset(slot);
639 return field_offset_from_byte_offset(offset);
640 }
641
642 UNSAFE_ENTRY(jlong, Unsafe_ObjectFieldOffset0(JNIEnv *env, jobject unsafe, jobject field)) {
643 return find_field_offset(field, 0, THREAD);
644 } UNSAFE_END
645
646 UNSAFE_ENTRY(jlong, Unsafe_ObjectFieldOffset1(JNIEnv *env, jobject unsafe, jclass c, jstring name)) {
647 return find_field_offset(c, name, THREAD);
648 } UNSAFE_END
649
650 UNSAFE_ENTRY(jlong, Unsafe_StaticFieldOffset0(JNIEnv *env, jobject unsafe, jobject field)) {
651 return find_field_offset(field, 1, THREAD);
652 } UNSAFE_END
653
654 UNSAFE_ENTRY(jobject, Unsafe_StaticFieldBase0(JNIEnv *env, jobject unsafe, jobject field)) {
655 assert(field != NULL, "field must not be NULL");
656
657 // Note: In this VM implementation, a field address is always a short
658 // offset from the base of a a klass metaobject. Thus, the full dynamic
659 // range of the return type is never used. However, some implementations
660 // might put the static field inside an array shared by many classes,
661 // or even at a fixed address, in which case the address could be quite
662 // large. In that last case, this function would return NULL, since
663 // the address would operate alone, without any base pointer.
664
665 oop reflected = JNIHandles::resolve_non_null(field);
666 oop mirror = java_lang_reflect_Field::clazz(reflected);
667 int modifiers = java_lang_reflect_Field::modifiers(reflected);
668
669 if ((modifiers & JVM_ACC_STATIC) == 0) {
670 THROW_0(vmSymbols::java_lang_IllegalArgumentException());
671 }
672
673 return JNIHandles::make_local(env, mirror);
674 } UNSAFE_END
675
676 UNSAFE_ENTRY(void, Unsafe_EnsureClassInitialized0(JNIEnv *env, jobject unsafe, jobject clazz)) {
677 assert(clazz != NULL, "clazz must not be NULL");
678
679 oop mirror = JNIHandles::resolve_non_null(clazz);
680
681 Klass* klass = java_lang_Class::as_Klass(mirror);
682 if (klass != NULL && klass->should_be_initialized()) {
683 InstanceKlass* k = InstanceKlass::cast(klass);
684 k->initialize(CHECK);
685 }
686 }
687 UNSAFE_END
688
689 UNSAFE_ENTRY(jboolean, Unsafe_ShouldBeInitialized0(JNIEnv *env, jobject unsafe, jobject clazz)) {
690 assert(clazz != NULL, "clazz must not be NULL");
691
692 oop mirror = JNIHandles::resolve_non_null(clazz);
693 Klass* klass = java_lang_Class::as_Klass(mirror);
694
695 if (klass != NULL && klass->should_be_initialized()) {
696 return true;
697 }
698
699 return false;
700 }
701 UNSAFE_END
702
703 static void getBaseAndScale(int& base, int& scale, jclass clazz, TRAPS) {
704 assert(clazz != NULL, "clazz must not be NULL");
705
706 oop mirror = JNIHandles::resolve_non_null(clazz);
707 Klass* k = java_lang_Class::as_Klass(mirror);
708
709 if (k == NULL || !k->is_array_klass()) {
710 THROW(vmSymbols::java_lang_InvalidClassException());
711 } else if (k->is_objArray_klass()) {
712 base = arrayOopDesc::base_offset_in_bytes(T_OBJECT);
713 scale = heapOopSize;
714 } else if (k->is_typeArray_klass()) {
715 TypeArrayKlass* tak = TypeArrayKlass::cast(k);
716 base = tak->array_header_in_bytes();
717 assert(base == arrayOopDesc::base_offset_in_bytes(tak->element_type()), "array_header_size semantics ok");
718 scale = (1 << tak->log2_element_size());
719 } else {
720 ShouldNotReachHere();
721 }
722 }
723
724 UNSAFE_ENTRY(jint, Unsafe_ArrayBaseOffset0(JNIEnv *env, jobject unsafe, jclass clazz)) {
725 int base = 0, scale = 0;
726 getBaseAndScale(base, scale, clazz, CHECK_0);
727
728 return field_offset_from_byte_offset(base);
729 } UNSAFE_END
730
731
732 UNSAFE_ENTRY(jint, Unsafe_ArrayIndexScale0(JNIEnv *env, jobject unsafe, jclass clazz)) {
733 int base = 0, scale = 0;
734 getBaseAndScale(base, scale, clazz, CHECK_0);
735
736 // This VM packs both fields and array elements down to the byte.
737 // But watch out: If this changes, so that array references for
738 // a given primitive type (say, T_BOOLEAN) use different memory units
739 // than fields, this method MUST return zero for such arrays.
740 // For example, the VM used to store sub-word sized fields in full
741 // words in the object layout, so that accessors like getByte(Object,int)
742 // did not really do what one might expect for arrays. Therefore,
743 // this function used to report a zero scale factor, so that the user
744 // would know not to attempt to access sub-word array elements.
745 // // Code for unpacked fields:
746 // if (scale < wordSize) return 0;
747
748 // The following allows for a pretty general fieldOffset cookie scheme,
749 // but requires it to be linear in byte offset.
750 return field_offset_from_byte_offset(scale) - field_offset_from_byte_offset(0);
751 } UNSAFE_END
752
753
754 static inline void throw_new(JNIEnv *env, const char *ename) {
755 jclass cls = env->FindClass(ename);
756 if (env->ExceptionCheck()) {
757 env->ExceptionClear();
758 tty->print_cr("Unsafe: cannot throw %s because FindClass has failed", ename);
759 return;
760 }
761
762 env->ThrowNew(cls, NULL);
763 }
764
765 static jclass Unsafe_DefineClass_impl(JNIEnv *env, jstring name, jbyteArray data, int offset, int length, jobject loader, jobject pd) {
766 // Code lifted from JDK 1.3 ClassLoader.c
767
768 jbyte *body;
769 char *utfName = NULL;
770 jclass result = 0;
771 char buf[128];
772
773 assert(data != NULL, "Class bytes must not be NULL");
774 assert(length >= 0, "length must not be negative: %d", length);
775
776 if (UsePerfData) {
777 ClassLoader::unsafe_defineClassCallCounter()->inc();
778 }
779
780 body = NEW_C_HEAP_ARRAY(jbyte, length, mtInternal);
781 if (body == NULL) {
782 throw_new(env, "java/lang/OutOfMemoryError");
783 return 0;
784 }
785
786 env->GetByteArrayRegion(data, offset, length, body);
787 if (env->ExceptionOccurred()) {
788 goto free_body;
789 }
790
791 if (name != NULL) {
792 uint len = env->GetStringUTFLength(name);
793 int unicode_len = env->GetStringLength(name);
794
795 if (len >= sizeof(buf)) {
796 utfName = NEW_C_HEAP_ARRAY(char, len + 1, mtInternal);
797 if (utfName == NULL) {
798 throw_new(env, "java/lang/OutOfMemoryError");
799 goto free_body;
800 }
801 } else {
802 utfName = buf;
803 }
804
805 env->GetStringUTFRegion(name, 0, unicode_len, utfName);
806
807 for (uint i = 0; i < len; i++) {
808 if (utfName[i] == '.') utfName[i] = '/';
809 }
810 }
811
812 result = JVM_DefineClass(env, utfName, loader, body, length, pd);
813
814 if (utfName && utfName != buf) {
815 FREE_C_HEAP_ARRAY(char, utfName);
816 }
817
818 free_body:
819 FREE_C_HEAP_ARRAY(jbyte, body);
820 return result;
821 }
822
823
824 UNSAFE_ENTRY(jclass, Unsafe_DefineClass0(JNIEnv *env, jobject unsafe, jstring name, jbyteArray data, int offset, int length, jobject loader, jobject pd)) {
825 ThreadToNativeFromVM ttnfv(thread);
826
827 return Unsafe_DefineClass_impl(env, name, data, offset, length, loader, pd);
828 } UNSAFE_END
829
830
831 // define a class but do not make it known to the class loader or system dictionary
832 // - host_class: supplies context for linkage, access control, protection domain, and class loader
833 // if host_class is itself anonymous then it is replaced with its host class.
834 // - data: bytes of a class file, a raw memory address (length gives the number of bytes)
835 // - cp_patches: where non-null entries exist, they replace corresponding CP entries in data
836
837 // When you load an anonymous class U, it works as if you changed its name just before loading,
838 // to a name that you will never use again. Since the name is lost, no other class can directly
839 // link to any member of U. Just after U is loaded, the only way to use it is reflectively,
840 // through java.lang.Class methods like Class.newInstance.
841
842 // The package of an anonymous class must either match its host's class's package or be in the
843 // unnamed package. If it is in the unnamed package then it will be put in its host class's
844 // package.
845 //
846
847 // Access checks for linkage sites within U continue to follow the same rules as for named classes.
848 // An anonymous class also has special privileges to access any member of its host class.
849 // This is the main reason why this loading operation is unsafe. The purpose of this is to
850 // allow language implementations to simulate "open classes"; a host class in effect gets
851 // new code when an anonymous class is loaded alongside it. A less convenient but more
852 // standard way to do this is with reflection, which can also be set to ignore access
853 // restrictions.
854
855 // Access into an anonymous class is possible only through reflection. Therefore, there
856 // are no special access rules for calling into an anonymous class. The relaxed access
857 // rule for the host class is applied in the opposite direction: A host class reflectively
858 // access one of its anonymous classes.
859
860 // If you load the same bytecodes twice, you get two different classes. You can reload
861 // the same bytecodes with or without varying CP patches.
862
863 // By using the CP patching array, you can have a new anonymous class U2 refer to an older one U1.
864 // The bytecodes for U2 should refer to U1 by a symbolic name (doesn't matter what the name is).
865 // The CONSTANT_Class entry for that name can be patched to refer directly to U1.
866
867 // This allows, for example, U2 to use U1 as a superclass or super-interface, or as
868 // an outer class (so that U2 is an anonymous inner class of anonymous U1).
869 // It is not possible for a named class, or an older anonymous class, to refer by
870 // name (via its CP) to a newer anonymous class.
871
872 // CP patching may also be used to modify (i.e., hack) the names of methods, classes,
873 // or type descriptors used in the loaded anonymous class.
874
875 // Finally, CP patching may be used to introduce "live" objects into the constant pool,
876 // instead of "dead" strings. A compiled statement like println((Object)"hello") can
877 // be changed to println(greeting), where greeting is an arbitrary object created before
878 // the anonymous class is loaded. This is useful in dynamic languages, in which
879 // various kinds of metaobjects must be introduced as constants into bytecode.
880 // Note the cast (Object), which tells the verifier to expect an arbitrary object,
881 // not just a literal string. For such ldc instructions, the verifier uses the
882 // type Object instead of String, if the loaded constant is not in fact a String.
883
884 static InstanceKlass*
885 Unsafe_DefineAnonymousClass_impl(JNIEnv *env,
886 jclass host_class, jbyteArray data, jobjectArray cp_patches_jh,
887 u1** temp_alloc,
888 TRAPS) {
889 assert(host_class != NULL, "host_class must not be NULL");
890 assert(data != NULL, "data must not be NULL");
891
892 if (UsePerfData) {
893 ClassLoader::unsafe_defineClassCallCounter()->inc();
894 }
895
896 jint length = typeArrayOop(JNIHandles::resolve_non_null(data))->length();
897 assert(length >= 0, "class_bytes_length must not be negative: %d", length);
898
899 int class_bytes_length = (int) length;
900
901 u1* class_bytes = NEW_C_HEAP_ARRAY(u1, length, mtInternal);
902 if (class_bytes == NULL) {
903 THROW_0(vmSymbols::java_lang_OutOfMemoryError());
904 }
905
906 // caller responsible to free it:
907 *temp_alloc = class_bytes;
908
909 jbyte* array_base = typeArrayOop(JNIHandles::resolve_non_null(data))->byte_at_addr(0);
910 Copy::conjoint_jbytes(array_base, class_bytes, length);
911
912 objArrayHandle cp_patches_h;
913 if (cp_patches_jh != NULL) {
914 oop p = JNIHandles::resolve_non_null(cp_patches_jh);
915 assert(p->is_objArray(), "cp_patches must be an object[]");
916 cp_patches_h = objArrayHandle(THREAD, (objArrayOop)p);
917 }
918
919 const Klass* host_klass = java_lang_Class::as_Klass(JNIHandles::resolve_non_null(host_class));
920
921 // Make sure it's the real host class, not another anonymous class.
922 while (host_klass != NULL && host_klass->is_instance_klass() &&
923 InstanceKlass::cast(host_klass)->is_anonymous()) {
924 host_klass = InstanceKlass::cast(host_klass)->host_klass();
925 }
926
927 // Primitive types have NULL Klass* fields in their java.lang.Class instances.
928 if (host_klass == NULL) {
929 THROW_MSG_0(vmSymbols::java_lang_IllegalArgumentException(), "Host class is null");
930 }
931
932 assert(host_klass->is_instance_klass(), "Host class must be an instance class");
933
934 const char* host_source = host_klass->external_name();
935 Handle host_loader(THREAD, host_klass->class_loader());
936 Handle host_domain(THREAD, host_klass->protection_domain());
937
938 GrowableArray<Handle>* cp_patches = NULL;
939
940 if (cp_patches_h.not_null()) {
941 int alen = cp_patches_h->length();
942
943 for (int i = alen-1; i >= 0; i--) {
944 oop p = cp_patches_h->obj_at(i);
945 if (p != NULL) {
946 Handle patch(THREAD, p);
947
948 if (cp_patches == NULL) {
949 cp_patches = new GrowableArray<Handle>(i+1, i+1, Handle());
950 }
951
952 cp_patches->at_put(i, patch);
953 }
954 }
955 }
956
957 ClassFileStream st(class_bytes, class_bytes_length, host_source, ClassFileStream::verify);
958
959 Symbol* no_class_name = NULL;
960 Klass* anonk = SystemDictionary::parse_stream(no_class_name,
961 host_loader,
962 host_domain,
963 &st,
964 InstanceKlass::cast(host_klass),
965 cp_patches,
966 CHECK_NULL);
967 if (anonk == NULL) {
968 return NULL;
969 }
970
971 return InstanceKlass::cast(anonk);
972 }
973
974 UNSAFE_ENTRY(jclass, Unsafe_DefineAnonymousClass0(JNIEnv *env, jobject unsafe, jclass host_class, jbyteArray data, jobjectArray cp_patches_jh)) {
975 ResourceMark rm(THREAD);
976
977 jobject res_jh = NULL;
978 u1* temp_alloc = NULL;
979
980 InstanceKlass* anon_klass = Unsafe_DefineAnonymousClass_impl(env, host_class, data, cp_patches_jh, &temp_alloc, THREAD);
981 if (anon_klass != NULL) {
982 res_jh = JNIHandles::make_local(env, anon_klass->java_mirror());
983 }
984
985 // try/finally clause:
986 if (temp_alloc != NULL) {
987 FREE_C_HEAP_ARRAY(u1, temp_alloc);
988 }
989
990 // The anonymous class loader data has been artificially been kept alive to
991 // this point. The mirror and any instances of this class have to keep
992 // it alive afterwards.
993 if (anon_klass != NULL) {
994 anon_klass->class_loader_data()->dec_keep_alive();
995 }
996
997 // let caller initialize it as needed...
998
999 return (jclass) res_jh;
1000 } UNSAFE_END
1001
1002
1003
1004 UNSAFE_ENTRY(void, Unsafe_ThrowException(JNIEnv *env, jobject unsafe, jthrowable thr)) {
1005 ThreadToNativeFromVM ttnfv(thread);
1006 env->Throw(thr);
1007 } UNSAFE_END
1008
1009 // JSR166 ------------------------------------------------------------------
1010
1011 UNSAFE_ENTRY(jobject, Unsafe_CompareAndExchangeObject(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jobject e_h, jobject x_h)) {
1012 oop x = JNIHandles::resolve(x_h);
1013 oop e = JNIHandles::resolve(e_h);
1014 oop p = JNIHandles::resolve(obj);
1015 HeapWord* addr = (HeapWord *)index_oop_from_field_offset_long(p, offset);
1016 oop res = oopDesc::atomic_compare_exchange_oop(x, addr, e, true);
1017 if (res == e) {
1018 update_barrier_set((void*)addr, x);
1019 }
1020 return JNIHandles::make_local(env, res);
1021 } UNSAFE_END
1022
1023 UNSAFE_ENTRY(jint, Unsafe_CompareAndExchangeInt(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jint e, jint x)) {
1024 oop p = JNIHandles::resolve(obj);
1025 jint* addr = (jint *) index_oop_from_field_offset_long(p, offset);
1026
1027 return (jint)(Atomic::cmpxchg(x, addr, e));
1028 } UNSAFE_END
1029
1030 UNSAFE_ENTRY(jlong, Unsafe_CompareAndExchangeLong(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jlong e, jlong x)) {
1031 Handle p(THREAD, JNIHandles::resolve(obj));
1032 jlong* addr = (jlong*)index_oop_from_field_offset_long(p(), offset);
1033
1034 #ifdef SUPPORTS_NATIVE_CX8
1035 return (jlong)(Atomic::cmpxchg(x, addr, e));
1036 #else
1037 if (VM_Version::supports_cx8()) {
1038 return (jlong)(Atomic::cmpxchg(x, addr, e));
1039 } else {
1040 MutexLockerEx mu(UnsafeJlong_lock, Mutex::_no_safepoint_check_flag);
1041
1042 jlong val = Atomic::load(addr);
1043 if (val == e) {
1044 Atomic::store(x, addr);
1045 }
1046 return val;
1047 }
1048 #endif
1049 } UNSAFE_END
1050
1051 UNSAFE_ENTRY(jboolean, Unsafe_CompareAndSetObject(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jobject e_h, jobject x_h)) {
1052 oop x = JNIHandles::resolve(x_h);
1053 oop e = JNIHandles::resolve(e_h);
1054 oop p = JNIHandles::resolve(obj);
1055 HeapWord* addr = (HeapWord *)index_oop_from_field_offset_long(p, offset);
1056 oop res = oopDesc::atomic_compare_exchange_oop(x, addr, e, true);
1057 if (res != e) {
1058 return false;
1059 }
1060
1061 update_barrier_set((void*)addr, x);
1062
1063 return true;
1064 } UNSAFE_END
1065
1066 UNSAFE_ENTRY(jboolean, Unsafe_CompareAndSetInt(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jint e, jint x)) {
1067 oop p = JNIHandles::resolve(obj);
1068 jint* addr = (jint *)index_oop_from_field_offset_long(p, offset);
1069
1070 return (jint)(Atomic::cmpxchg(x, addr, e)) == e;
1071 } UNSAFE_END
1072
1073 UNSAFE_ENTRY(jboolean, Unsafe_CompareAndSetLong(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jlong e, jlong x)) {
1074 Handle p(THREAD, JNIHandles::resolve(obj));
1075 jlong* addr = (jlong*)index_oop_from_field_offset_long(p(), offset);
1076
1077 #ifdef SUPPORTS_NATIVE_CX8
1078 return (jlong)(Atomic::cmpxchg(x, addr, e)) == e;
1079 #else
1080 if (VM_Version::supports_cx8()) {
1081 return (jlong)(Atomic::cmpxchg(x, addr, e)) == e;
1082 } else {
1083 MutexLockerEx mu(UnsafeJlong_lock, Mutex::_no_safepoint_check_flag);
1084
1085 jlong val = Atomic::load(addr);
1086 if (val != e) {
1087 return false;
1088 }
1089
1090 Atomic::store(x, addr);
1091 return true;
1092 }
1093 #endif
1094 } UNSAFE_END
1095
1096 UNSAFE_ENTRY(void, Unsafe_Park(JNIEnv *env, jobject unsafe, jboolean isAbsolute, jlong time)) {
1097 EventThreadPark event;
1098 HOTSPOT_THREAD_PARK_BEGIN((uintptr_t) thread->parker(), (int) isAbsolute, time);
1099
1100 JavaThreadParkedState jtps(thread, time != 0);
1101 thread->parker()->park(isAbsolute != 0, time);
1102
1103 HOTSPOT_THREAD_PARK_END((uintptr_t) thread->parker());
1104
1105 if (event.should_commit()) {
1106 oop obj = thread->current_park_blocker();
1107 event.set_parkedClass((obj != NULL) ? obj->klass() : NULL);
1108 event.set_timeout(time);
1109 event.set_address((obj != NULL) ? (TYPE_ADDRESS) cast_from_oop<uintptr_t>(obj) : 0);
1110 event.commit();
1111 }
1112 } UNSAFE_END
1113
1114 UNSAFE_ENTRY(void, Unsafe_Unpark(JNIEnv *env, jobject unsafe, jobject jthread)) {
1115 Parker* p = NULL;
1116
1117 if (jthread != NULL) {
1118 oop java_thread = JNIHandles::resolve_non_null(jthread);
1119 if (java_thread != NULL) {
1120 jlong lp = java_lang_Thread::park_event(java_thread);
1121 if (lp != 0) {
1122 // This cast is OK even though the jlong might have been read
1123 // non-atomically on 32bit systems, since there, one word will
1124 // always be zero anyway and the value set is always the same
1125 p = (Parker*)addr_from_java(lp);
1126 } else {
1127 // Grab lock if apparently null or using older version of library
1128 MutexLocker mu(Threads_lock);
1129 java_thread = JNIHandles::resolve_non_null(jthread);
1130
1131 if (java_thread != NULL) {
1132 JavaThread* thr = java_lang_Thread::thread(java_thread);
1133 if (thr != NULL) {
1134 p = thr->parker();
1135 if (p != NULL) { // Bind to Java thread for next time.
1136 java_lang_Thread::set_park_event(java_thread, addr_to_java(p));
1137 }
1138 }
1139 }
1140 }
1141 }
1142 }
1143
1144 if (p != NULL) {
1145 HOTSPOT_THREAD_UNPARK((uintptr_t) p);
1146 p->unpark();
1147 }
1148 } UNSAFE_END
1149
1150 UNSAFE_ENTRY(jint, Unsafe_GetLoadAverage0(JNIEnv *env, jobject unsafe, jdoubleArray loadavg, jint nelem)) {
1151 const int max_nelem = 3;
1152 double la[max_nelem];
1153 jint ret;
1154
1155 typeArrayOop a = typeArrayOop(JNIHandles::resolve_non_null(loadavg));
1156 assert(a->is_typeArray(), "must be type array");
1157
1158 ret = os::loadavg(la, nelem);
1159 if (ret == -1) {
1160 return -1;
1161 }
1162
1163 // if successful, ret is the number of samples actually retrieved.
1164 assert(ret >= 0 && ret <= max_nelem, "Unexpected loadavg return value");
1165 switch(ret) {
1166 case 3: a->double_at_put(2, (jdouble)la[2]); // fall through
1167 case 2: a->double_at_put(1, (jdouble)la[1]); // fall through
1168 case 1: a->double_at_put(0, (jdouble)la[0]); break;
1169 }
1170
1171 return ret;
1172 } UNSAFE_END
1173
1174
1175 /// JVM_RegisterUnsafeMethods
1176
1177 #define ADR "J"
1178
1179 #define LANG "Ljava/lang/"
1180
1181 #define OBJ LANG "Object;"
1182 #define CLS LANG "Class;"
1183 #define FLD LANG "reflect/Field;"
1184 #define THR LANG "Throwable;"
1185
1186 #define DC_Args LANG "String;[BII" LANG "ClassLoader;" "Ljava/security/ProtectionDomain;"
1187 #define DAC_Args CLS "[B[" OBJ
1188
1189 #define CC (char*) /*cast a literal from (const char*)*/
1190 #define FN_PTR(f) CAST_FROM_FN_PTR(void*, &f)
1191
1192 #define DECLARE_GETPUTOOP(Type, Desc) \
1193 {CC "get" #Type, CC "(" OBJ "J)" #Desc, FN_PTR(Unsafe_Get##Type)}, \
1194 {CC "put" #Type, CC "(" OBJ "J" #Desc ")V", FN_PTR(Unsafe_Put##Type)}, \
1195 {CC "get" #Type "Volatile", CC "(" OBJ "J)" #Desc, FN_PTR(Unsafe_Get##Type##Volatile)}, \
1196 {CC "put" #Type "Volatile", CC "(" OBJ "J" #Desc ")V", FN_PTR(Unsafe_Put##Type##Volatile)}
1197
1198
1199 static JNINativeMethod jdk_internal_misc_Unsafe_methods[] = {
1200 {CC "getObject", CC "(" OBJ "J)" OBJ "", FN_PTR(Unsafe_GetObject)},
1201 {CC "putObject", CC "(" OBJ "J" OBJ ")V", FN_PTR(Unsafe_PutObject)},
1202 {CC "getObjectVolatile",CC "(" OBJ "J)" OBJ "", FN_PTR(Unsafe_GetObjectVolatile)},
1203 {CC "putObjectVolatile",CC "(" OBJ "J" OBJ ")V", FN_PTR(Unsafe_PutObjectVolatile)},
1204
1205 {CC "getUncompressedObject", CC "(" ADR ")" OBJ, FN_PTR(Unsafe_GetUncompressedObject)},
1206
1207 DECLARE_GETPUTOOP(Boolean, Z),
1208 DECLARE_GETPUTOOP(Byte, B),
1209 DECLARE_GETPUTOOP(Short, S),
1210 DECLARE_GETPUTOOP(Char, C),
1211 DECLARE_GETPUTOOP(Int, I),
1212 DECLARE_GETPUTOOP(Long, J),
1213 DECLARE_GETPUTOOP(Float, F),
1214 DECLARE_GETPUTOOP(Double, D),
1215
1216 {CC "allocateMemory0", CC "(J)" ADR, FN_PTR(Unsafe_AllocateMemory0)},
1217 {CC "reallocateMemory0", CC "(" ADR "J)" ADR, FN_PTR(Unsafe_ReallocateMemory0)},
1218 {CC "freeMemory0", CC "(" ADR ")V", FN_PTR(Unsafe_FreeMemory0)},
1219
1220 {CC "objectFieldOffset0", CC "(" FLD ")J", FN_PTR(Unsafe_ObjectFieldOffset0)},
1221 {CC "objectFieldOffset1", CC "(" CLS LANG "String;)J", FN_PTR(Unsafe_ObjectFieldOffset1)},
1222 {CC "staticFieldOffset0", CC "(" FLD ")J", FN_PTR(Unsafe_StaticFieldOffset0)},
1223 {CC "staticFieldBase0", CC "(" FLD ")" OBJ, FN_PTR(Unsafe_StaticFieldBase0)},
1224 {CC "ensureClassInitialized0", CC "(" CLS ")V", FN_PTR(Unsafe_EnsureClassInitialized0)},
1225 {CC "arrayBaseOffset0", CC "(" CLS ")I", FN_PTR(Unsafe_ArrayBaseOffset0)},
1226 {CC "arrayIndexScale0", CC "(" CLS ")I", FN_PTR(Unsafe_ArrayIndexScale0)},
1227 {CC "addressSize0", CC "()I", FN_PTR(Unsafe_AddressSize0)},
1228 {CC "pageSize", CC "()I", FN_PTR(Unsafe_PageSize)},
1229
1230 {CC "defineClass0", CC "(" DC_Args ")" CLS, FN_PTR(Unsafe_DefineClass0)},
1231 {CC "allocateInstance", CC "(" CLS ")" OBJ, FN_PTR(Unsafe_AllocateInstance)},
1232 {CC "throwException", CC "(" THR ")V", FN_PTR(Unsafe_ThrowException)},
1233 {CC "compareAndSetObject",CC "(" OBJ "J" OBJ "" OBJ ")Z", FN_PTR(Unsafe_CompareAndSetObject)},
1234 {CC "compareAndSetInt", CC "(" OBJ "J""I""I"")Z", FN_PTR(Unsafe_CompareAndSetInt)},
1235 {CC "compareAndSetLong", CC "(" OBJ "J""J""J"")Z", FN_PTR(Unsafe_CompareAndSetLong)},
1236 {CC "compareAndExchangeObject", CC "(" OBJ "J" OBJ "" OBJ ")" OBJ, FN_PTR(Unsafe_CompareAndExchangeObject)},
1237 {CC "compareAndExchangeInt", CC "(" OBJ "J""I""I"")I", FN_PTR(Unsafe_CompareAndExchangeInt)},
1238 {CC "compareAndExchangeLong", CC "(" OBJ "J""J""J"")J", FN_PTR(Unsafe_CompareAndExchangeLong)},
1239
1240 {CC "park", CC "(ZJ)V", FN_PTR(Unsafe_Park)},
1241 {CC "unpark", CC "(" OBJ ")V", FN_PTR(Unsafe_Unpark)},
1242
1243 {CC "getLoadAverage0", CC "([DI)I", FN_PTR(Unsafe_GetLoadAverage0)},
1244
1245 {CC "copyMemory0", CC "(" OBJ "J" OBJ "JJ)V", FN_PTR(Unsafe_CopyMemory0)},
1246 {CC "copySwapMemory0", CC "(" OBJ "J" OBJ "JJJ)V", FN_PTR(Unsafe_CopySwapMemory0)},
1247 {CC "setMemory0", CC "(" OBJ "JJB)V", FN_PTR(Unsafe_SetMemory0)},
1248
1249 {CC "defineAnonymousClass0", CC "(" DAC_Args ")" CLS, FN_PTR(Unsafe_DefineAnonymousClass0)},
1250
1251 {CC "shouldBeInitialized0", CC "(" CLS ")Z", FN_PTR(Unsafe_ShouldBeInitialized0)},
1252
1253 {CC "loadFence", CC "()V", FN_PTR(Unsafe_LoadFence)},
1254 {CC "storeFence", CC "()V", FN_PTR(Unsafe_StoreFence)},
1255 {CC "fullFence", CC "()V", FN_PTR(Unsafe_FullFence)},
1256
1257 {CC "isBigEndian0", CC "()Z", FN_PTR(Unsafe_isBigEndian0)},
1258 {CC "unalignedAccess0", CC "()Z", FN_PTR(Unsafe_unalignedAccess0)}
1259 };
1260
1261 #undef CC
1262 #undef FN_PTR
1263
1264 #undef ADR
1265 #undef LANG
1266 #undef OBJ
1267 #undef CLS
1268 #undef FLD
1269 #undef THR
1270 #undef DC_Args
1271 #undef DAC_Args
1272
1273 #undef DECLARE_GETPUTOOP
1274
1275
1276 // This function is exported, used by NativeLookup.
1277 // The Unsafe_xxx functions above are called only from the interpreter.
1278 // The optimizer looks at names and signatures to recognize
1279 // individual functions.
1280
1281 JVM_ENTRY(void, JVM_RegisterJDKInternalMiscUnsafeMethods(JNIEnv *env, jclass unsafeclass)) {
1282 ThreadToNativeFromVM ttnfv(thread);
1283
1284 int ok = env->RegisterNatives(unsafeclass, jdk_internal_misc_Unsafe_methods, sizeof(jdk_internal_misc_Unsafe_methods)/sizeof(JNINativeMethod));
1285 guarantee(ok == 0, "register jdk.internal.misc.Unsafe natives");
1286 } JVM_END