1 /*
2 * Copyright (c) 2000, 2016, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "precompiled.hpp"
26 #include "classfile/classFileStream.hpp"
27 #include "classfile/vmSymbols.hpp"
28 #include "memory/allocation.inline.hpp"
29 #include "memory/resourceArea.hpp"
30 #include "oops/objArrayOop.inline.hpp"
31 #include "oops/oop.inline.hpp"
32 #include "prims/jni.h"
33 #include "prims/jvm.h"
34 #include "prims/unsafe.hpp"
35 #include "runtime/atomic.inline.hpp"
36 #include "runtime/globals.hpp"
37 #include "runtime/interfaceSupport.hpp"
38 #include "runtime/orderAccess.inline.hpp"
39 #include "runtime/reflection.hpp"
40 #include "runtime/vm_version.hpp"
41 #include "services/threadService.hpp"
42 #include "trace/tracing.hpp"
43 #include "utilities/copy.hpp"
44 #include "utilities/dtrace.hpp"
45 #include "utilities/macros.hpp"
46 #if INCLUDE_ALL_GCS
47 #include "gc/g1/g1SATBCardTableModRefBS.hpp"
48 #endif // INCLUDE_ALL_GCS
49
50 /**
51 * Implementation of the jdk.internal.misc.Unsafe class
52 */
53
54
55 #define MAX_OBJECT_SIZE \
56 ( arrayOopDesc::header_size(T_DOUBLE) * HeapWordSize \
57 + ((julong)max_jint * sizeof(double)) )
58
59
60 #define UNSAFE_ENTRY(result_type, header) \
61 JVM_ENTRY(static result_type, header)
62
63 #define UNSAFE_LEAF(result_type, header) \
64 JVM_LEAF(static result_type, header)
65
66 #define UNSAFE_END JVM_END
67
68
69 static inline void* addr_from_java(jlong addr) {
70 // This assert fails in a variety of ways on 32-bit systems.
71 // It is impossible to predict whether native code that converts
72 // pointers to longs will sign-extend or zero-extend the addresses.
73 //assert(addr == (uintptr_t)addr, "must not be odd high bits");
74 return (void*)(uintptr_t)addr;
75 }
76
77 static inline jlong addr_to_java(void* p) {
78 assert(p == (void*)(uintptr_t)p, "must not be odd high bits");
79 return (uintptr_t)p;
80 }
81
82
83 // Note: The VM's obj_field and related accessors use byte-scaled
84 // ("unscaled") offsets, just as the unsafe methods do.
85
86 // However, the method Unsafe.fieldOffset explicitly declines to
87 // guarantee this. The field offset values manipulated by the Java user
88 // through the Unsafe API are opaque cookies that just happen to be byte
89 // offsets. We represent this state of affairs by passing the cookies
90 // through conversion functions when going between the VM and the Unsafe API.
91 // The conversion functions just happen to be no-ops at present.
92
93 static inline jlong field_offset_to_byte_offset(jlong field_offset) {
94 return field_offset;
95 }
96
97 static inline jlong field_offset_from_byte_offset(jlong byte_offset) {
98 return byte_offset;
99 }
100
101 static inline void* index_oop_from_field_offset_long(oop p, jlong field_offset) {
102 jlong byte_offset = field_offset_to_byte_offset(field_offset);
103
104 #ifdef ASSERT
105 if (p != NULL) {
106 assert(byte_offset >= 0 && byte_offset <= (jlong)MAX_OBJECT_SIZE, "sane offset");
107 if (byte_offset == (jint)byte_offset) {
108 void* ptr_plus_disp = (address)p + byte_offset;
109 assert((void*)p->obj_field_addr<oop>((jint)byte_offset) == ptr_plus_disp,
110 "raw [ptr+disp] must be consistent with oop::field_base");
111 }
112 jlong p_size = HeapWordSize * (jlong)(p->size());
113 assert(byte_offset < p_size, "Unsafe access: offset " INT64_FORMAT " > object's size " INT64_FORMAT, byte_offset, p_size);
114 }
115 #endif
116
117 if (sizeof(char*) == sizeof(jint)) { // (this constant folds!)
118 return (address)p + (jint) byte_offset;
119 } else {
120 return (address)p + byte_offset;
121 }
122 }
123
124 // Externally callable versions:
125 // (Use these in compiler intrinsics which emulate unsafe primitives.)
126 jlong Unsafe_field_offset_to_byte_offset(jlong field_offset) {
127 return field_offset;
128 }
129 jlong Unsafe_field_offset_from_byte_offset(jlong byte_offset) {
130 return byte_offset;
131 }
132
133
134 ///// Data in the Java heap.
135
136 #define GET_FIELD(obj, offset, type_name, v) \
137 oop p = JNIHandles::resolve(obj); \
138 type_name v = *(type_name*)index_oop_from_field_offset_long(p, offset)
139
140 #define SET_FIELD(obj, offset, type_name, x) \
141 oop p = JNIHandles::resolve(obj); \
142 *(type_name*)index_oop_from_field_offset_long(p, offset) = x
143
144 #define GET_FIELD_VOLATILE(obj, offset, type_name, v) \
145 oop p = JNIHandles::resolve(obj); \
146 if (support_IRIW_for_not_multiple_copy_atomic_cpu) { \
147 OrderAccess::fence(); \
148 } \
149 volatile type_name v = OrderAccess::load_acquire((volatile type_name*)index_oop_from_field_offset_long(p, offset));
150
151 #define SET_FIELD_VOLATILE(obj, offset, type_name, x) \
152 oop p = JNIHandles::resolve(obj); \
153 OrderAccess::release_store_fence((volatile type_name*)index_oop_from_field_offset_long(p, offset), x);
154
155
156 // Get/SetObject must be special-cased, since it works with handles.
157
158 // These functions allow a null base pointer with an arbitrary address.
159 // But if the base pointer is non-null, the offset should make some sense.
160 // That is, it should be in the range [0, MAX_OBJECT_SIZE].
161 UNSAFE_ENTRY(jobject, Unsafe_GetObject(JNIEnv *env, jobject unsafe, jobject obj, jlong offset)) {
162 oop p = JNIHandles::resolve(obj);
163 oop v;
164
165 if (UseCompressedOops) {
166 narrowOop n = *(narrowOop*)index_oop_from_field_offset_long(p, offset);
167 v = oopDesc::decode_heap_oop(n);
168 } else {
169 v = *(oop*)index_oop_from_field_offset_long(p, offset);
170 }
171
172 jobject ret = JNIHandles::make_local(env, v);
173
174 #if INCLUDE_ALL_GCS
175 // We could be accessing the referent field in a reference
176 // object. If G1 is enabled then we need to register non-null
177 // referent with the SATB barrier.
178 if (UseG1GC) {
179 bool needs_barrier = false;
180
181 if (ret != NULL) {
182 if (offset == java_lang_ref_Reference::referent_offset && obj != NULL) {
183 oop o = JNIHandles::resolve(obj);
184 Klass* k = o->klass();
185 if (InstanceKlass::cast(k)->reference_type() != REF_NONE) {
186 assert(InstanceKlass::cast(k)->is_subclass_of(SystemDictionary::Reference_klass()), "sanity");
187 needs_barrier = true;
188 }
189 }
190 }
191
192 if (needs_barrier) {
193 oop referent = JNIHandles::resolve(ret);
194 G1SATBCardTableModRefBS::enqueue(referent);
195 }
196 }
197 #endif // INCLUDE_ALL_GCS
198
199 return ret;
200 } UNSAFE_END
201
202 UNSAFE_ENTRY(void, Unsafe_SetObject(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jobject x_h)) {
203 oop x = JNIHandles::resolve(x_h);
204 oop p = JNIHandles::resolve(obj);
205
206 if (UseCompressedOops) {
207 oop_store((narrowOop*)index_oop_from_field_offset_long(p, offset), x);
208 } else {
209 oop_store((oop*)index_oop_from_field_offset_long(p, offset), x);
210 }
211 } UNSAFE_END
212
213 UNSAFE_ENTRY(jobject, Unsafe_GetObjectVolatile(JNIEnv *env, jobject unsafe, jobject obj, jlong offset)) {
214 oop p = JNIHandles::resolve(obj);
215 void* addr = index_oop_from_field_offset_long(p, offset);
216
217 volatile oop v;
218
219 if (UseCompressedOops) {
220 volatile narrowOop n = *(volatile narrowOop*) addr;
221 (void)const_cast<oop&>(v = oopDesc::decode_heap_oop(n));
222 } else {
223 (void)const_cast<oop&>(v = *(volatile oop*) addr);
224 }
225
226 OrderAccess::acquire();
227 return JNIHandles::make_local(env, v);
228 } UNSAFE_END
229
230 UNSAFE_ENTRY(void, Unsafe_SetObjectVolatile(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jobject x_h)) {
231 oop x = JNIHandles::resolve(x_h);
232 oop p = JNIHandles::resolve(obj);
233 void* addr = index_oop_from_field_offset_long(p, offset);
234 OrderAccess::release();
235
236 if (UseCompressedOops) {
237 oop_store((narrowOop*)addr, x);
238 } else {
239 oop_store((oop*)addr, x);
240 }
241
242 OrderAccess::fence();
243 } UNSAFE_END
244
245 UNSAFE_ENTRY(jobject, Unsafe_GetUncompressedObject(JNIEnv *env, jobject unsafe, jlong addr)) {
246 oop v = *(oop*) (address) addr;
247
248 return JNIHandles::make_local(env, v);
249 } UNSAFE_END
250
251 UNSAFE_ENTRY(jclass, Unsafe_GetJavaMirror(JNIEnv *env, jobject unsafe, jlong metaspace_klass)) {
252 Klass* klass = (Klass*) (address) metaspace_klass;
253
254 return (jclass) JNIHandles::make_local(klass->java_mirror());
255 } UNSAFE_END
256
257 UNSAFE_ENTRY(jlong, Unsafe_GetKlassPointer(JNIEnv *env, jobject unsafe, jobject obj)) {
258 oop o = JNIHandles::resolve(obj);
259 jlong klass = (jlong) (address) o->klass();
260
261 return klass;
262 } UNSAFE_END
263
264 #ifndef SUPPORTS_NATIVE_CX8
265
266 // VM_Version::supports_cx8() is a surrogate for 'supports atomic long memory ops'.
267 //
268 // On platforms which do not support atomic compare-and-swap of jlong (8 byte)
269 // values we have to use a lock-based scheme to enforce atomicity. This has to be
270 // applied to all Unsafe operations that set the value of a jlong field. Even so
271 // the compareAndSwapLong operation will not be atomic with respect to direct stores
272 // to the field from Java code. It is important therefore that any Java code that
273 // utilizes these Unsafe jlong operations does not perform direct stores. To permit
274 // direct loads of the field from Java code we must also use Atomic::store within the
275 // locked regions. And for good measure, in case there are direct stores, we also
276 // employ Atomic::load within those regions. Note that the field in question must be
277 // volatile and so must have atomic load/store accesses applied at the Java level.
278 //
279 // The locking scheme could utilize a range of strategies for controlling the locking
280 // granularity: from a lock per-field through to a single global lock. The latter is
281 // the simplest and is used for the current implementation. Note that the Java object
282 // that contains the field, can not, in general, be used for locking. To do so can lead
283 // to deadlocks as we may introduce locking into what appears to the Java code to be a
284 // lock-free path.
285 //
286 // As all the locked-regions are very short and themselves non-blocking we can treat
287 // them as leaf routines and elide safepoint checks (ie we don't perform any thread
288 // state transitions even when blocking for the lock). Note that if we do choose to
289 // add safepoint checks and thread state transitions, we must ensure that we calculate
290 // the address of the field _after_ we have acquired the lock, else the object may have
291 // been moved by the GC
292
293 UNSAFE_ENTRY(jlong, Unsafe_GetLongVolatile(JNIEnv *env, jobject unsafe, jobject obj, jlong offset)) {
294 if (VM_Version::supports_cx8()) {
295 GET_FIELD_VOLATILE(obj, offset, jlong, v);
296 return v;
297 } else {
298 Handle p (THREAD, JNIHandles::resolve(obj));
299 jlong* addr = (jlong*)(index_oop_from_field_offset_long(p(), offset));
300 MutexLockerEx mu(UnsafeJlong_lock, Mutex::_no_safepoint_check_flag);
301 jlong value = Atomic::load(addr);
302 return value;
303 }
304 } UNSAFE_END
305
306 UNSAFE_ENTRY(void, Unsafe_SetLongVolatile(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jlong x)) {
307 if (VM_Version::supports_cx8()) {
308 SET_FIELD_VOLATILE(obj, offset, jlong, x);
309 } else {
310 Handle p (THREAD, JNIHandles::resolve(obj));
311 jlong* addr = (jlong*)(index_oop_from_field_offset_long(p(), offset));
312 MutexLockerEx mu(UnsafeJlong_lock, Mutex::_no_safepoint_check_flag);
313 Atomic::store(x, addr);
314 }
315 } UNSAFE_END
316
317 #endif // not SUPPORTS_NATIVE_CX8
318
319 UNSAFE_LEAF(jboolean, Unsafe_isBigEndian0(JNIEnv *env, jobject unsafe)) {
320 #ifdef VM_LITTLE_ENDIAN
321 return false;
322 #else
323 return true;
324 #endif
325 } UNSAFE_END
326
327 UNSAFE_LEAF(jint, Unsafe_unalignedAccess0(JNIEnv *env, jobject unsafe)) {
328 return UseUnalignedAccesses;
329 } UNSAFE_END
330
331 #define DEFINE_GETSETOOP(java_type, Type) \
332 \
333 UNSAFE_ENTRY(java_type, Unsafe_Get##Type(JNIEnv *env, jobject unsafe, jobject obj, jlong offset)) { \
334 GET_FIELD(obj, offset, java_type, v); \
335 return v; \
336 } UNSAFE_END \
337 \
338 UNSAFE_ENTRY(void, Unsafe_Set##Type(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, java_type x)) { \
339 SET_FIELD(obj, offset, java_type, x); \
340 } UNSAFE_END \
341 \
342 // END DEFINE_GETSETOOP.
343
344 DEFINE_GETSETOOP(jboolean, Boolean)
345 DEFINE_GETSETOOP(jbyte, Byte)
346 DEFINE_GETSETOOP(jshort, Short);
347 DEFINE_GETSETOOP(jchar, Char);
348 DEFINE_GETSETOOP(jint, Int);
349 DEFINE_GETSETOOP(jlong, Long);
350 DEFINE_GETSETOOP(jfloat, Float);
351 DEFINE_GETSETOOP(jdouble, Double);
352
353 #undef DEFINE_GETSETOOP
354
355 #define DEFINE_GETSETOOP_VOLATILE(java_type, Type) \
356 \
357 UNSAFE_ENTRY(java_type, Unsafe_Get##Type##Volatile(JNIEnv *env, jobject unsafe, jobject obj, jlong offset)) { \
358 GET_FIELD_VOLATILE(obj, offset, java_type, v); \
359 return v; \
360 } UNSAFE_END \
361 \
362 UNSAFE_ENTRY(void, Unsafe_Set##Type##Volatile(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, java_type x)) { \
363 SET_FIELD_VOLATILE(obj, offset, java_type, x); \
364 } UNSAFE_END \
365 \
366 // END DEFINE_GETSETOOP_VOLATILE.
367
368 DEFINE_GETSETOOP_VOLATILE(jboolean, Boolean)
369 DEFINE_GETSETOOP_VOLATILE(jbyte, Byte)
370 DEFINE_GETSETOOP_VOLATILE(jshort, Short);
371 DEFINE_GETSETOOP_VOLATILE(jchar, Char);
372 DEFINE_GETSETOOP_VOLATILE(jint, Int);
373 DEFINE_GETSETOOP_VOLATILE(jfloat, Float);
374 DEFINE_GETSETOOP_VOLATILE(jdouble, Double);
375
376 #ifdef SUPPORTS_NATIVE_CX8
377 DEFINE_GETSETOOP_VOLATILE(jlong, Long);
378 #endif
379
380 #undef DEFINE_GETSETOOP_VOLATILE
381
382 UNSAFE_LEAF(void, Unsafe_LoadFence(JNIEnv *env, jobject unsafe)) {
383 OrderAccess::acquire();
384 } UNSAFE_END
385
386 UNSAFE_LEAF(void, Unsafe_StoreFence(JNIEnv *env, jobject unsafe)) {
387 OrderAccess::release();
388 } UNSAFE_END
389
390 UNSAFE_LEAF(void, Unsafe_FullFence(JNIEnv *env, jobject unsafe)) {
391 OrderAccess::fence();
392 } UNSAFE_END
393
394 ////// Data in the C heap.
395
396 // Note: These do not throw NullPointerException for bad pointers.
397 // They just crash. Only a oop base pointer can generate a NullPointerException.
398 //
399 #define DEFINE_GETSETNATIVE(java_type, Type, native_type) \
400 \
401 UNSAFE_ENTRY(java_type, Unsafe_GetNative##Type(JNIEnv *env, jobject unsafe, jlong addr)) { \
402 void* p = addr_from_java(addr); \
403 JavaThread* t = JavaThread::current(); \
404 t->set_doing_unsafe_access(true); \
405 java_type x = *(volatile native_type*)p; \
406 t->set_doing_unsafe_access(false); \
407 return x; \
408 } UNSAFE_END \
409 \
410 UNSAFE_ENTRY(void, Unsafe_SetNative##Type(JNIEnv *env, jobject unsafe, jlong addr, java_type x)) { \
411 JavaThread* t = JavaThread::current(); \
412 t->set_doing_unsafe_access(true); \
413 void* p = addr_from_java(addr); \
414 *(volatile native_type*)p = x; \
415 t->set_doing_unsafe_access(false); \
416 } UNSAFE_END \
417 \
418 // END DEFINE_GETSETNATIVE.
419
420 DEFINE_GETSETNATIVE(jbyte, Byte, signed char)
421 DEFINE_GETSETNATIVE(jshort, Short, signed short);
422 DEFINE_GETSETNATIVE(jchar, Char, unsigned short);
423 DEFINE_GETSETNATIVE(jint, Int, jint);
424 // no long -- handled specially
425 DEFINE_GETSETNATIVE(jfloat, Float, float);
426 DEFINE_GETSETNATIVE(jdouble, Double, double);
427
428 #undef DEFINE_GETSETNATIVE
429
430 UNSAFE_ENTRY(jlong, Unsafe_GetNativeLong(JNIEnv *env, jobject unsafe, jlong addr)) {
431 JavaThread* t = JavaThread::current();
432 // We do it this way to avoid problems with access to heap using 64
433 // bit loads, as jlong in heap could be not 64-bit aligned, and on
434 // some CPUs (SPARC) it leads to SIGBUS.
435 t->set_doing_unsafe_access(true);
436 void* p = addr_from_java(addr);
437 jlong x;
438
439 if (is_ptr_aligned(p, sizeof(jlong)) == 0) {
440 // jlong is aligned, do a volatile access
441 x = *(volatile jlong*)p;
442 } else {
443 jlong_accessor acc;
444 acc.words[0] = ((volatile jint*)p)[0];
445 acc.words[1] = ((volatile jint*)p)[1];
446 x = acc.long_value;
447 }
448
449 t->set_doing_unsafe_access(false);
450
451 return x;
452 } UNSAFE_END
453
454 UNSAFE_ENTRY(void, Unsafe_SetNativeLong(JNIEnv *env, jobject unsafe, jlong addr, jlong x)) {
455 JavaThread* t = JavaThread::current();
456 // see comment for Unsafe_GetNativeLong
457 t->set_doing_unsafe_access(true);
458 void* p = addr_from_java(addr);
459
460 if (is_ptr_aligned(p, sizeof(jlong))) {
461 // jlong is aligned, do a volatile access
462 *(volatile jlong*)p = x;
463 } else {
464 jlong_accessor acc;
465 acc.long_value = x;
466 ((volatile jint*)p)[0] = acc.words[0];
467 ((volatile jint*)p)[1] = acc.words[1];
468 }
469
470 t->set_doing_unsafe_access(false);
471 } UNSAFE_END
472
473
474 UNSAFE_LEAF(jlong, Unsafe_GetNativeAddress(JNIEnv *env, jobject unsafe, jlong addr)) {
475 void* p = addr_from_java(addr);
476
477 return addr_to_java(*(void**)p);
478 } UNSAFE_END
479
480 UNSAFE_LEAF(void, Unsafe_SetNativeAddress(JNIEnv *env, jobject unsafe, jlong addr, jlong x)) {
481 void* p = addr_from_java(addr);
482 *(void**)p = addr_from_java(x);
483 } UNSAFE_END
484
485
486 ////// Allocation requests
487
488 UNSAFE_ENTRY(jobject, Unsafe_AllocateInstance(JNIEnv *env, jobject unsafe, jclass cls)) {
489 ThreadToNativeFromVM ttnfv(thread);
490 return env->AllocObject(cls);
491 } UNSAFE_END
492
493 UNSAFE_ENTRY(jlong, Unsafe_AllocateMemory0(JNIEnv *env, jobject unsafe, jlong size)) {
494 size_t sz = (size_t)size;
495
496 sz = round_to(sz, HeapWordSize);
497 void* x = os::malloc(sz, mtInternal);
498
499 return addr_to_java(x);
500 } UNSAFE_END
501
502 UNSAFE_ENTRY(jlong, Unsafe_ReallocateMemory0(JNIEnv *env, jobject unsafe, jlong addr, jlong size)) {
503 void* p = addr_from_java(addr);
504 size_t sz = (size_t)size;
505 sz = round_to(sz, HeapWordSize);
506
507 void* x = os::realloc(p, sz, mtInternal);
508
509 return addr_to_java(x);
510 } UNSAFE_END
511
512 UNSAFE_ENTRY(void, Unsafe_FreeMemory0(JNIEnv *env, jobject unsafe, jlong addr)) {
513 void* p = addr_from_java(addr);
514
515 os::free(p);
516 } UNSAFE_END
517
518 UNSAFE_ENTRY(void, Unsafe_SetMemory0(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jlong size, jbyte value)) {
519 size_t sz = (size_t)size;
520
521 oop base = JNIHandles::resolve(obj);
522 void* p = index_oop_from_field_offset_long(base, offset);
523
524 Copy::fill_to_memory_atomic(p, sz, value);
525 } UNSAFE_END
526
527 UNSAFE_ENTRY(void, Unsafe_CopyMemory0(JNIEnv *env, jobject unsafe, jobject srcObj, jlong srcOffset, jobject dstObj, jlong dstOffset, jlong size)) {
528 size_t sz = (size_t)size;
529
530 oop srcp = JNIHandles::resolve(srcObj);
531 oop dstp = JNIHandles::resolve(dstObj);
532
533 void* src = index_oop_from_field_offset_long(srcp, srcOffset);
534 void* dst = index_oop_from_field_offset_long(dstp, dstOffset);
535
536 Copy::conjoint_memory_atomic(src, dst, sz);
537 } UNSAFE_END
538
539 // This function is a leaf since if the source and destination are both in native memory
540 // the copy may potentially be very large, and we don't want to disable GC if we can avoid it.
541 // If either source or destination (or both) are on the heap, the function will enter VM using
542 // JVM_ENTRY_FROM_LEAF
543 UNSAFE_LEAF(void, Unsafe_CopySwapMemory0(JNIEnv *env, jobject unsafe, jobject srcObj, jlong srcOffset, jobject dstObj, jlong dstOffset, jlong size, jlong elemSize)) {
544 size_t sz = (size_t)size;
545 size_t esz = (size_t)elemSize;
546
547 if (srcObj == NULL && dstObj == NULL) {
548 // Both src & dst are in native memory
549 address src = (address)srcOffset;
550 address dst = (address)dstOffset;
551
552 Copy::conjoint_swap(src, dst, sz, esz);
553 } else {
554 // At least one of src/dst are on heap, transition to VM to access raw pointers
555
556 JVM_ENTRY_FROM_LEAF(env, void, Unsafe_CopySwapMemory0) {
557 oop srcp = JNIHandles::resolve(srcObj);
558 oop dstp = JNIHandles::resolve(dstObj);
559
560 address src = (address)index_oop_from_field_offset_long(srcp, srcOffset);
561 address dst = (address)index_oop_from_field_offset_long(dstp, dstOffset);
562
563 Copy::conjoint_swap(src, dst, sz, esz);
564 } JVM_END
565 }
566 } UNSAFE_END
567
568 ////// Random queries
569
570 UNSAFE_LEAF(jint, Unsafe_AddressSize0(JNIEnv *env, jobject unsafe)) {
571 return sizeof(void*);
572 } UNSAFE_END
573
574 UNSAFE_LEAF(jint, Unsafe_PageSize()) {
575 return os::vm_page_size();
576 } UNSAFE_END
577
578 static jint find_field_offset(jobject field, int must_be_static, TRAPS) {
579 assert(field != NULL, "field must not be NULL");
580
581 oop reflected = JNIHandles::resolve_non_null(field);
582 oop mirror = java_lang_reflect_Field::clazz(reflected);
583 Klass* k = java_lang_Class::as_Klass(mirror);
584 int slot = java_lang_reflect_Field::slot(reflected);
585 int modifiers = java_lang_reflect_Field::modifiers(reflected);
586
587 if (must_be_static >= 0) {
588 int really_is_static = ((modifiers & JVM_ACC_STATIC) != 0);
589 if (must_be_static != really_is_static) {
590 THROW_0(vmSymbols::java_lang_IllegalArgumentException());
591 }
592 }
593
594 int offset = InstanceKlass::cast(k)->field_offset(slot);
595 return field_offset_from_byte_offset(offset);
596 }
597
598 UNSAFE_ENTRY(jlong, Unsafe_ObjectFieldOffset0(JNIEnv *env, jobject unsafe, jobject field)) {
599 return find_field_offset(field, 0, THREAD);
600 } UNSAFE_END
601
602 UNSAFE_ENTRY(jlong, Unsafe_StaticFieldOffset0(JNIEnv *env, jobject unsafe, jobject field)) {
603 return find_field_offset(field, 1, THREAD);
604 } UNSAFE_END
605
606 UNSAFE_ENTRY(jobject, Unsafe_StaticFieldBase0(JNIEnv *env, jobject unsafe, jobject field)) {
607 assert(field != NULL, "field must not be NULL");
608
609 // Note: In this VM implementation, a field address is always a short
610 // offset from the base of a a klass metaobject. Thus, the full dynamic
611 // range of the return type is never used. However, some implementations
612 // might put the static field inside an array shared by many classes,
613 // or even at a fixed address, in which case the address could be quite
614 // large. In that last case, this function would return NULL, since
615 // the address would operate alone, without any base pointer.
616
617 oop reflected = JNIHandles::resolve_non_null(field);
618 oop mirror = java_lang_reflect_Field::clazz(reflected);
619 int modifiers = java_lang_reflect_Field::modifiers(reflected);
620
621 if ((modifiers & JVM_ACC_STATIC) == 0) {
622 THROW_0(vmSymbols::java_lang_IllegalArgumentException());
623 }
624
625 return JNIHandles::make_local(env, mirror);
626 } UNSAFE_END
627
628 UNSAFE_ENTRY(void, Unsafe_EnsureClassInitialized0(JNIEnv *env, jobject unsafe, jobject clazz)) {
629 assert(clazz != NULL, "clazz must not be NULL");
630
631 oop mirror = JNIHandles::resolve_non_null(clazz);
632
633 Klass* klass = java_lang_Class::as_Klass(mirror);
634 if (klass != NULL && klass->should_be_initialized()) {
635 InstanceKlass* k = InstanceKlass::cast(klass);
636 k->initialize(CHECK);
637 }
638 }
639 UNSAFE_END
640
641 UNSAFE_ENTRY(jboolean, Unsafe_ShouldBeInitialized0(JNIEnv *env, jobject unsafe, jobject clazz)) {
642 assert(clazz != NULL, "clazz must not be NULL");
643
644 oop mirror = JNIHandles::resolve_non_null(clazz);
645 Klass* klass = java_lang_Class::as_Klass(mirror);
646
647 if (klass != NULL && klass->should_be_initialized()) {
648 return true;
649 }
650
651 return false;
652 }
653 UNSAFE_END
654
655 static void getBaseAndScale(int& base, int& scale, jclass clazz, TRAPS) {
656 assert(clazz != NULL, "clazz must not be NULL");
657
658 oop mirror = JNIHandles::resolve_non_null(clazz);
659 Klass* k = java_lang_Class::as_Klass(mirror);
660
661 if (k == NULL || !k->is_array_klass()) {
662 THROW(vmSymbols::java_lang_InvalidClassException());
663 } else if (k->is_objArray_klass()) {
664 base = arrayOopDesc::base_offset_in_bytes(T_OBJECT);
665 scale = heapOopSize;
666 } else if (k->is_typeArray_klass()) {
667 TypeArrayKlass* tak = TypeArrayKlass::cast(k);
668 base = tak->array_header_in_bytes();
669 assert(base == arrayOopDesc::base_offset_in_bytes(tak->element_type()), "array_header_size semantics ok");
670 scale = (1 << tak->log2_element_size());
671 } else {
672 ShouldNotReachHere();
673 }
674 }
675
676 UNSAFE_ENTRY(jint, Unsafe_ArrayBaseOffset0(JNIEnv *env, jobject unsafe, jclass clazz)) {
677 int base = 0, scale = 0;
678 getBaseAndScale(base, scale, clazz, CHECK_0);
679
680 return field_offset_from_byte_offset(base);
681 } UNSAFE_END
682
683
684 UNSAFE_ENTRY(jint, Unsafe_ArrayIndexScale0(JNIEnv *env, jobject unsafe, jclass clazz)) {
685 int base = 0, scale = 0;
686 getBaseAndScale(base, scale, clazz, CHECK_0);
687
688 // This VM packs both fields and array elements down to the byte.
689 // But watch out: If this changes, so that array references for
690 // a given primitive type (say, T_BOOLEAN) use different memory units
691 // than fields, this method MUST return zero for such arrays.
692 // For example, the VM used to store sub-word sized fields in full
693 // words in the object layout, so that accessors like getByte(Object,int)
694 // did not really do what one might expect for arrays. Therefore,
695 // this function used to report a zero scale factor, so that the user
696 // would know not to attempt to access sub-word array elements.
697 // // Code for unpacked fields:
698 // if (scale < wordSize) return 0;
699
700 // The following allows for a pretty general fieldOffset cookie scheme,
701 // but requires it to be linear in byte offset.
702 return field_offset_from_byte_offset(scale) - field_offset_from_byte_offset(0);
703 } UNSAFE_END
704
705
706 static inline void throw_new(JNIEnv *env, const char *ename) {
707 char buf[100];
708
709 jio_snprintf(buf, 100, "%s%s", "java/lang/", ename);
710
711 jclass cls = env->FindClass(buf);
712 if (env->ExceptionCheck()) {
713 env->ExceptionClear();
714 tty->print_cr("Unsafe: cannot throw %s because FindClass has failed", buf);
715 return;
716 }
717
718 env->ThrowNew(cls, NULL);
719 }
720
721 static jclass Unsafe_DefineClass_impl(JNIEnv *env, jstring name, jbyteArray data, int offset, int length, jobject loader, jobject pd) {
722 // Code lifted from JDK 1.3 ClassLoader.c
723
724 jbyte *body;
725 char *utfName = NULL;
726 jclass result = 0;
727 char buf[128];
728
729 assert(data != NULL, "Class bytes must not be NULL");
730 assert(length >= 0, "length must not be negative: %d", length);
731
732 if (UsePerfData) {
733 ClassLoader::unsafe_defineClassCallCounter()->inc();
734 }
735
736 body = NEW_C_HEAP_ARRAY(jbyte, length, mtInternal);
737 if (body == NULL) {
738 throw_new(env, "OutOfMemoryError");
739 return 0;
740 }
741
742 env->GetByteArrayRegion(data, offset, length, body);
743 if (env->ExceptionOccurred()) {
744 goto free_body;
745 }
746
747 if (name != NULL) {
748 uint len = env->GetStringUTFLength(name);
749 int unicode_len = env->GetStringLength(name);
750
751 if (len >= sizeof(buf)) {
752 utfName = NEW_C_HEAP_ARRAY(char, len + 1, mtInternal);
753 if (utfName == NULL) {
754 throw_new(env, "OutOfMemoryError");
755 goto free_body;
756 }
757 } else {
758 utfName = buf;
759 }
760
761 env->GetStringUTFRegion(name, 0, unicode_len, utfName);
762
763 for (uint i = 0; i < len; i++) {
764 if (utfName[i] == '.') utfName[i] = '/';
765 }
766 }
767
768 result = JVM_DefineClass(env, utfName, loader, body, length, pd);
769
770 if (utfName && utfName != buf) {
771 FREE_C_HEAP_ARRAY(char, utfName);
772 }
773
774 free_body:
775 FREE_C_HEAP_ARRAY(jbyte, body);
776 return result;
777 }
778
779
780 UNSAFE_ENTRY(jclass, Unsafe_DefineClass0(JNIEnv *env, jobject unsafe, jstring name, jbyteArray data, int offset, int length, jobject loader, jobject pd)) {
781 ThreadToNativeFromVM ttnfv(thread);
782
783 return Unsafe_DefineClass_impl(env, name, data, offset, length, loader, pd);
784 } UNSAFE_END
785
786
787 // define a class but do not make it known to the class loader or system dictionary
788 // - host_class: supplies context for linkage, access control, protection domain, and class loader
789 // - data: bytes of a class file, a raw memory address (length gives the number of bytes)
790 // - cp_patches: where non-null entries exist, they replace corresponding CP entries in data
791
792 // When you load an anonymous class U, it works as if you changed its name just before loading,
793 // to a name that you will never use again. Since the name is lost, no other class can directly
794 // link to any member of U. Just after U is loaded, the only way to use it is reflectively,
795 // through java.lang.Class methods like Class.newInstance.
796
797 // Access checks for linkage sites within U continue to follow the same rules as for named classes.
798 // The package of an anonymous class is given by the package qualifier on the name under which it was loaded.
799 // An anonymous class also has special privileges to access any member of its host class.
800 // This is the main reason why this loading operation is unsafe. The purpose of this is to
801 // allow language implementations to simulate "open classes"; a host class in effect gets
802 // new code when an anonymous class is loaded alongside it. A less convenient but more
803 // standard way to do this is with reflection, which can also be set to ignore access
804 // restrictions.
805
806 // Access into an anonymous class is possible only through reflection. Therefore, there
807 // are no special access rules for calling into an anonymous class. The relaxed access
808 // rule for the host class is applied in the opposite direction: A host class reflectively
809 // access one of its anonymous classes.
810
811 // If you load the same bytecodes twice, you get two different classes. You can reload
812 // the same bytecodes with or without varying CP patches.
813
814 // By using the CP patching array, you can have a new anonymous class U2 refer to an older one U1.
815 // The bytecodes for U2 should refer to U1 by a symbolic name (doesn't matter what the name is).
816 // The CONSTANT_Class entry for that name can be patched to refer directly to U1.
817
818 // This allows, for example, U2 to use U1 as a superclass or super-interface, or as
819 // an outer class (so that U2 is an anonymous inner class of anonymous U1).
820 // It is not possible for a named class, or an older anonymous class, to refer by
821 // name (via its CP) to a newer anonymous class.
822
823 // CP patching may also be used to modify (i.e., hack) the names of methods, classes,
824 // or type descriptors used in the loaded anonymous class.
825
826 // Finally, CP patching may be used to introduce "live" objects into the constant pool,
827 // instead of "dead" strings. A compiled statement like println((Object)"hello") can
828 // be changed to println(greeting), where greeting is an arbitrary object created before
829 // the anonymous class is loaded. This is useful in dynamic languages, in which
830 // various kinds of metaobjects must be introduced as constants into bytecode.
831 // Note the cast (Object), which tells the verifier to expect an arbitrary object,
832 // not just a literal string. For such ldc instructions, the verifier uses the
833 // type Object instead of String, if the loaded constant is not in fact a String.
834
835 static instanceKlassHandle
836 Unsafe_DefineAnonymousClass_impl(JNIEnv *env,
837 jclass host_class, jbyteArray data, jobjectArray cp_patches_jh,
838 u1** temp_alloc,
839 TRAPS) {
840 assert(host_class != NULL, "host_class must not be NULL");
841 assert(data != NULL, "data must not be NULL");
842
843 if (UsePerfData) {
844 ClassLoader::unsafe_defineClassCallCounter()->inc();
845 }
846
847 jint length = typeArrayOop(JNIHandles::resolve_non_null(data))->length();
848 assert(length >= 0, "class_bytes_length must not be negative: %d", length);
849
850 int class_bytes_length = (int) length;
851
852 u1* class_bytes = NEW_C_HEAP_ARRAY(u1, length, mtInternal);
853 if (class_bytes == NULL) {
854 THROW_0(vmSymbols::java_lang_OutOfMemoryError());
855 }
856
857 // caller responsible to free it:
858 *temp_alloc = class_bytes;
859
860 jbyte* array_base = typeArrayOop(JNIHandles::resolve_non_null(data))->byte_at_addr(0);
861 Copy::conjoint_jbytes(array_base, class_bytes, length);
862
863 objArrayHandle cp_patches_h;
864 if (cp_patches_jh != NULL) {
865 oop p = JNIHandles::resolve_non_null(cp_patches_jh);
866 assert(p->is_objArray(), "cp_patches must be an object[]");
867 cp_patches_h = objArrayHandle(THREAD, (objArrayOop)p);
868 }
869
870 const Klass* host_klass = java_lang_Class::as_Klass(JNIHandles::resolve_non_null(host_class));
871 // Primitive types have NULL Klass* fields in their java.lang.Class instances.
872 if (host_klass == NULL) {
873 THROW_0(vmSymbols::java_lang_IllegalArgumentException());
874 }
875
876 const char* host_source = host_klass->external_name();
877 Handle host_loader(THREAD, host_klass->class_loader());
878 Handle host_domain(THREAD, host_klass->protection_domain());
879
880 GrowableArray<Handle>* cp_patches = NULL;
881
882 if (cp_patches_h.not_null()) {
883 int alen = cp_patches_h->length();
884
885 for (int i = alen-1; i >= 0; i--) {
886 oop p = cp_patches_h->obj_at(i);
887 if (p != NULL) {
888 Handle patch(THREAD, p);
889
890 if (cp_patches == NULL) {
891 cp_patches = new GrowableArray<Handle>(i+1, i+1, Handle());
892 }
893
894 cp_patches->at_put(i, patch);
895 }
896 }
897 }
898
899 ClassFileStream st(class_bytes, class_bytes_length, host_source, ClassFileStream::verify);
900
901 Symbol* no_class_name = NULL;
902 Klass* anonk = SystemDictionary::parse_stream(no_class_name,
903 host_loader,
904 host_domain,
905 &st,
906 host_klass,
907 cp_patches,
908 CHECK_NULL);
909 if (anonk == NULL) {
910 return NULL;
911 }
912
913 return instanceKlassHandle(THREAD, anonk);
914 }
915
916 UNSAFE_ENTRY(jclass, Unsafe_DefineAnonymousClass0(JNIEnv *env, jobject unsafe, jclass host_class, jbyteArray data, jobjectArray cp_patches_jh)) {
917 ResourceMark rm(THREAD);
918
919 instanceKlassHandle anon_klass;
920 jobject res_jh = NULL;
921 u1* temp_alloc = NULL;
922
923 anon_klass = Unsafe_DefineAnonymousClass_impl(env, host_class, data, cp_patches_jh, &temp_alloc, THREAD);
924 if (anon_klass() != NULL) {
925 res_jh = JNIHandles::make_local(env, anon_klass->java_mirror());
926 }
927
928 // try/finally clause:
929 if (temp_alloc != NULL) {
930 FREE_C_HEAP_ARRAY(u1, temp_alloc);
931 }
932
933 // The anonymous class loader data has been artificially been kept alive to
934 // this point. The mirror and any instances of this class have to keep
935 // it alive afterwards.
936 if (anon_klass() != NULL) {
937 anon_klass->class_loader_data()->set_keep_alive(false);
938 }
939
940 // let caller initialize it as needed...
941
942 return (jclass) res_jh;
943 } UNSAFE_END
944
945
946
947 UNSAFE_ENTRY(void, Unsafe_ThrowException(JNIEnv *env, jobject unsafe, jthrowable thr)) {
948 ThreadToNativeFromVM ttnfv(thread);
949 env->Throw(thr);
950 } UNSAFE_END
951
952 // JSR166 ------------------------------------------------------------------
953
954 UNSAFE_ENTRY(jobject, Unsafe_CompareAndExchangeObject(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jobject e_h, jobject x_h)) {
955 oop x = JNIHandles::resolve(x_h);
956 oop e = JNIHandles::resolve(e_h);
957 oop p = JNIHandles::resolve(obj);
958 HeapWord* addr = (HeapWord *)index_oop_from_field_offset_long(p, offset);
959 oop res = oopDesc::atomic_compare_exchange_oop(x, addr, e, true);
960 if (res == e) {
961 update_barrier_set((void*)addr, x);
962 }
963 return JNIHandles::make_local(env, res);
964 } UNSAFE_END
965
966 UNSAFE_ENTRY(jint, Unsafe_CompareAndExchangeInt(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jint e, jint x)) {
967 oop p = JNIHandles::resolve(obj);
968 jint* addr = (jint *) index_oop_from_field_offset_long(p, offset);
969
970 return (jint)(Atomic::cmpxchg(x, addr, e));
971 } UNSAFE_END
972
973 UNSAFE_ENTRY(jlong, Unsafe_CompareAndExchangeLong(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jlong e, jlong x)) {
974 Handle p (THREAD, JNIHandles::resolve(obj));
975 jlong* addr = (jlong*)(index_oop_from_field_offset_long(p(), offset));
976
977 #ifdef SUPPORTS_NATIVE_CX8
978 return (jlong)(Atomic::cmpxchg(x, addr, e));
979 #else
980 if (VM_Version::supports_cx8()) {
981 return (jlong)(Atomic::cmpxchg(x, addr, e));
982 } else {
983 MutexLockerEx mu(UnsafeJlong_lock, Mutex::_no_safepoint_check_flag);
984
985 jlong val = Atomic::load(addr);
986 if (val == e) {
987 Atomic::store(x, addr);
988 }
989 return val;
990 }
991 #endif
992 } UNSAFE_END
993
994 UNSAFE_ENTRY(jboolean, Unsafe_CompareAndSwapObject(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jobject e_h, jobject x_h)) {
995 oop x = JNIHandles::resolve(x_h);
996 oop e = JNIHandles::resolve(e_h);
997 oop p = JNIHandles::resolve(obj);
998 HeapWord* addr = (HeapWord *)index_oop_from_field_offset_long(p, offset);
999 oop res = oopDesc::atomic_compare_exchange_oop(x, addr, e, true);
1000 if (res != e) {
1001 return false;
1002 }
1003
1004 update_barrier_set((void*)addr, x);
1005
1006 return true;
1007 } UNSAFE_END
1008
1009 UNSAFE_ENTRY(jboolean, Unsafe_CompareAndSwapInt(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jint e, jint x)) {
1010 oop p = JNIHandles::resolve(obj);
1011 jint* addr = (jint *) index_oop_from_field_offset_long(p, offset);
1012
1013 return (jint)(Atomic::cmpxchg(x, addr, e)) == e;
1014 } UNSAFE_END
1015
1016 UNSAFE_ENTRY(jboolean, Unsafe_CompareAndSwapLong(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jlong e, jlong x)) {
1017 Handle p(THREAD, JNIHandles::resolve(obj));
1018 jlong* addr = (jlong*)index_oop_from_field_offset_long(p(), offset);
1019
1020 #ifdef SUPPORTS_NATIVE_CX8
1021 return (jlong)(Atomic::cmpxchg(x, addr, e)) == e;
1022 #else
1023 if (VM_Version::supports_cx8()) {
1024 return (jlong)(Atomic::cmpxchg(x, addr, e)) == e;
1025 } else {
1026 MutexLockerEx mu(UnsafeJlong_lock, Mutex::_no_safepoint_check_flag);
1027
1028 jlong val = Atomic::load(addr);
1029 if (val != e) {
1030 return false;
1031 }
1032
1033 Atomic::store(x, addr);
1034 return true;
1035 }
1036 #endif
1037 } UNSAFE_END
1038
1039 UNSAFE_ENTRY(void, Unsafe_Park(JNIEnv *env, jobject unsafe, jboolean isAbsolute, jlong time)) {
1040 EventThreadPark event;
1041 HOTSPOT_THREAD_PARK_BEGIN((uintptr_t) thread->parker(), (int) isAbsolute, time);
1042
1043 JavaThreadParkedState jtps(thread, time != 0);
1044 thread->parker()->park(isAbsolute != 0, time);
1045
1046 HOTSPOT_THREAD_PARK_END((uintptr_t) thread->parker());
1047
1048 if (event.should_commit()) {
1049 oop obj = thread->current_park_blocker();
1050 event.set_klass((obj != NULL) ? obj->klass() : NULL);
1051 event.set_timeout(time);
1052 event.set_address((obj != NULL) ? (TYPE_ADDRESS) cast_from_oop<uintptr_t>(obj) : 0);
1053 event.commit();
1054 }
1055 } UNSAFE_END
1056
1057 UNSAFE_ENTRY(void, Unsafe_Unpark(JNIEnv *env, jobject unsafe, jobject jthread)) {
1058 Parker* p = NULL;
1059
1060 if (jthread != NULL) {
1061 oop java_thread = JNIHandles::resolve_non_null(jthread);
1062 if (java_thread != NULL) {
1063 jlong lp = java_lang_Thread::park_event(java_thread);
1064 if (lp != 0) {
1065 // This cast is OK even though the jlong might have been read
1066 // non-atomically on 32bit systems, since there, one word will
1067 // always be zero anyway and the value set is always the same
1068 p = (Parker*)addr_from_java(lp);
1069 } else {
1070 // Grab lock if apparently null or using older version of library
1071 MutexLocker mu(Threads_lock);
1072 java_thread = JNIHandles::resolve_non_null(jthread);
1073
1074 if (java_thread != NULL) {
1075 JavaThread* thr = java_lang_Thread::thread(java_thread);
1076 if (thr != NULL) {
1077 p = thr->parker();
1078 if (p != NULL) { // Bind to Java thread for next time.
1079 java_lang_Thread::set_park_event(java_thread, addr_to_java(p));
1080 }
1081 }
1082 }
1083 }
1084 }
1085 }
1086
1087 if (p != NULL) {
1088 HOTSPOT_THREAD_UNPARK((uintptr_t) p);
1089 p->unpark();
1090 }
1091 } UNSAFE_END
1092
1093 UNSAFE_ENTRY(jint, Unsafe_GetLoadAverage0(JNIEnv *env, jobject unsafe, jdoubleArray loadavg, jint nelem)) {
1094 const int max_nelem = 3;
1095 double la[max_nelem];
1096 jint ret;
1097
1098 typeArrayOop a = typeArrayOop(JNIHandles::resolve_non_null(loadavg));
1099 assert(a->is_typeArray(), "must be type array");
1100
1101 ret = os::loadavg(la, nelem);
1102 if (ret == -1) {
1103 return -1;
1104 }
1105
1106 // if successful, ret is the number of samples actually retrieved.
1107 assert(ret >= 0 && ret <= max_nelem, "Unexpected loadavg return value");
1108 switch(ret) {
1109 case 3: a->double_at_put(2, (jdouble)la[2]); // fall through
1110 case 2: a->double_at_put(1, (jdouble)la[1]); // fall through
1111 case 1: a->double_at_put(0, (jdouble)la[0]); break;
1112 }
1113
1114 return ret;
1115 } UNSAFE_END
1116
1117
1118 /// JVM_RegisterUnsafeMethods
1119
1120 #define ADR "J"
1121
1122 #define LANG "Ljava/lang/"
1123
1124 #define OBJ LANG "Object;"
1125 #define CLS LANG "Class;"
1126 #define FLD LANG "reflect/Field;"
1127 #define THR LANG "Throwable;"
1128
1129 #define DC_Args LANG "String;[BII" LANG "ClassLoader;" "Ljava/security/ProtectionDomain;"
1130 #define DAC_Args CLS "[B[" OBJ
1131
1132 #define CC (char*) /*cast a literal from (const char*)*/
1133 #define FN_PTR(f) CAST_FROM_FN_PTR(void*, &f)
1134
1135 #define DECLARE_GETPUTOOP(Type, Desc) \
1136 {CC "get" #Type, CC "(" OBJ "J)" #Desc, FN_PTR(Unsafe_Get##Type)}, \
1137 {CC "put" #Type, CC "(" OBJ "J" #Desc ")V", FN_PTR(Unsafe_Set##Type)}, \
1138 {CC "get" #Type "Volatile", CC "(" OBJ "J)" #Desc, FN_PTR(Unsafe_Get##Type##Volatile)}, \
1139 {CC "put" #Type "Volatile", CC "(" OBJ "J" #Desc ")V", FN_PTR(Unsafe_Set##Type##Volatile)}
1140
1141
1142 #define DECLARE_GETPUTNATIVE(Byte, B) \
1143 {CC "get" #Byte, CC "(" ADR ")" #B, FN_PTR(Unsafe_GetNative##Byte)}, \
1144 {CC "put" #Byte, CC "(" ADR#B ")V", FN_PTR(Unsafe_SetNative##Byte)}
1145
1146 static JNINativeMethod jdk_internal_misc_Unsafe_methods[] = {
1147 {CC "getObject", CC "(" OBJ "J)" OBJ "", FN_PTR(Unsafe_GetObject)},
1148 {CC "putObject", CC "(" OBJ "J" OBJ ")V", FN_PTR(Unsafe_SetObject)},
1149 {CC "getObjectVolatile",CC "(" OBJ "J)" OBJ "", FN_PTR(Unsafe_GetObjectVolatile)},
1150 {CC "putObjectVolatile",CC "(" OBJ "J" OBJ ")V", FN_PTR(Unsafe_SetObjectVolatile)},
1151
1152 {CC "getUncompressedObject", CC "(" ADR ")" OBJ, FN_PTR(Unsafe_GetUncompressedObject)},
1153 {CC "getJavaMirror", CC "(" ADR ")" CLS, FN_PTR(Unsafe_GetJavaMirror)},
1154 {CC "getKlassPointer", CC "(" OBJ ")" ADR, FN_PTR(Unsafe_GetKlassPointer)},
1155
1156 DECLARE_GETPUTOOP(Boolean, Z),
1157 DECLARE_GETPUTOOP(Byte, B),
1158 DECLARE_GETPUTOOP(Short, S),
1159 DECLARE_GETPUTOOP(Char, C),
1160 DECLARE_GETPUTOOP(Int, I),
1161 DECLARE_GETPUTOOP(Long, J),
1162 DECLARE_GETPUTOOP(Float, F),
1163 DECLARE_GETPUTOOP(Double, D),
1164
1165 DECLARE_GETPUTNATIVE(Byte, B),
1166 DECLARE_GETPUTNATIVE(Short, S),
1167 DECLARE_GETPUTNATIVE(Char, C),
1168 DECLARE_GETPUTNATIVE(Int, I),
1169 DECLARE_GETPUTNATIVE(Long, J),
1170 DECLARE_GETPUTNATIVE(Float, F),
1171 DECLARE_GETPUTNATIVE(Double, D),
1172
1173 {CC "getAddress", CC "(" ADR ")" ADR, FN_PTR(Unsafe_GetNativeAddress)},
1174 {CC "putAddress", CC "(" ADR "" ADR ")V", FN_PTR(Unsafe_SetNativeAddress)},
1175
1176 {CC "allocateMemory0", CC "(J)" ADR, FN_PTR(Unsafe_AllocateMemory0)},
1177 {CC "reallocateMemory0", CC "(" ADR "J)" ADR, FN_PTR(Unsafe_ReallocateMemory0)},
1178 {CC "freeMemory0", CC "(" ADR ")V", FN_PTR(Unsafe_FreeMemory0)},
1179
1180 {CC "objectFieldOffset0", CC "(" FLD ")J", FN_PTR(Unsafe_ObjectFieldOffset0)},
1181 {CC "staticFieldOffset0", CC "(" FLD ")J", FN_PTR(Unsafe_StaticFieldOffset0)},
1182 {CC "staticFieldBase0", CC "(" FLD ")" OBJ, FN_PTR(Unsafe_StaticFieldBase0)},
1183 {CC "ensureClassInitialized0", CC "(" CLS ")V", FN_PTR(Unsafe_EnsureClassInitialized0)},
1184 {CC "arrayBaseOffset0", CC "(" CLS ")I", FN_PTR(Unsafe_ArrayBaseOffset0)},
1185 {CC "arrayIndexScale0", CC "(" CLS ")I", FN_PTR(Unsafe_ArrayIndexScale0)},
1186 {CC "addressSize0", CC "()I", FN_PTR(Unsafe_AddressSize0)},
1187 {CC "pageSize", CC "()I", FN_PTR(Unsafe_PageSize)},
1188
1189 {CC "defineClass0", CC "(" DC_Args ")" CLS, FN_PTR(Unsafe_DefineClass0)},
1190 {CC "allocateInstance", CC "(" CLS ")" OBJ, FN_PTR(Unsafe_AllocateInstance)},
1191 {CC "throwException", CC "(" THR ")V", FN_PTR(Unsafe_ThrowException)},
1192 {CC "compareAndSwapObject", CC "(" OBJ "J" OBJ "" OBJ ")Z", FN_PTR(Unsafe_CompareAndSwapObject)},
1193 {CC "compareAndSwapInt", CC "(" OBJ "J""I""I"")Z", FN_PTR(Unsafe_CompareAndSwapInt)},
1194 {CC "compareAndSwapLong", CC "(" OBJ "J""J""J"")Z", FN_PTR(Unsafe_CompareAndSwapLong)},
1195 {CC "compareAndExchangeObjectVolatile", CC "(" OBJ "J" OBJ "" OBJ ")" OBJ, FN_PTR(Unsafe_CompareAndExchangeObject)},
1196 {CC "compareAndExchangeIntVolatile", CC "(" OBJ "J""I""I"")I", FN_PTR(Unsafe_CompareAndExchangeInt)},
1197 {CC "compareAndExchangeLongVolatile", CC "(" OBJ "J""J""J"")J", FN_PTR(Unsafe_CompareAndExchangeLong)},
1198
1199 {CC "park", CC "(ZJ)V", FN_PTR(Unsafe_Park)},
1200 {CC "unpark", CC "(" OBJ ")V", FN_PTR(Unsafe_Unpark)},
1201
1202 {CC "getLoadAverage0", CC "([DI)I", FN_PTR(Unsafe_GetLoadAverage0)},
1203
1204 {CC "copyMemory0", CC "(" OBJ "J" OBJ "JJ)V", FN_PTR(Unsafe_CopyMemory0)},
1205 {CC "copySwapMemory0", CC "(" OBJ "J" OBJ "JJJ)V", FN_PTR(Unsafe_CopySwapMemory0)},
1206 {CC "setMemory0", CC "(" OBJ "JJB)V", FN_PTR(Unsafe_SetMemory0)},
1207
1208 {CC "defineAnonymousClass0", CC "(" DAC_Args ")" CLS, FN_PTR(Unsafe_DefineAnonymousClass0)},
1209
1210 {CC "shouldBeInitialized0", CC "(" CLS ")Z", FN_PTR(Unsafe_ShouldBeInitialized0)},
1211
1212 {CC "loadFence", CC "()V", FN_PTR(Unsafe_LoadFence)},
1213 {CC "storeFence", CC "()V", FN_PTR(Unsafe_StoreFence)},
1214 {CC "fullFence", CC "()V", FN_PTR(Unsafe_FullFence)},
1215
1216 {CC "isBigEndian0", CC "()Z", FN_PTR(Unsafe_isBigEndian0)},
1217 {CC "unalignedAccess0", CC "()Z", FN_PTR(Unsafe_unalignedAccess0)}
1218 };
1219
1220 #undef CC
1221 #undef FN_PTR
1222
1223 #undef ADR
1224 #undef LANG
1225 #undef OBJ
1226 #undef CLS
1227 #undef FLD
1228 #undef THR
1229 #undef DC_Args
1230 #undef DAC_Args
1231
1232 #undef DECLARE_GETPUTOOP
1233 #undef DECLARE_GETPUTNATIVE
1234
1235
1236 // This function is exported, used by NativeLookup.
1237 // The Unsafe_xxx functions above are called only from the interpreter.
1238 // The optimizer looks at names and signatures to recognize
1239 // individual functions.
1240
1241 JVM_ENTRY(void, JVM_RegisterJDKInternalMiscUnsafeMethods(JNIEnv *env, jclass unsafeclass)) {
1242 ThreadToNativeFromVM ttnfv(thread);
1243
1244 int ok = env->RegisterNatives(unsafeclass, jdk_internal_misc_Unsafe_methods, sizeof(jdk_internal_misc_Unsafe_methods)/sizeof(JNINativeMethod));
1245 guarantee(ok == 0, "register jdk.internal.misc.Unsafe natives");
1246 } JVM_END