1 /*
2 * Copyright (c) 2000, 2015, 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/vmSymbols.hpp"
27 #include "memory/allocation.inline.hpp"
28 #include "oops/objArrayOop.inline.hpp"
29 #include "oops/oop.inline.hpp"
30 #include "prims/jni.h"
31 #include "prims/jvm.h"
32 #include "runtime/atomic.inline.hpp"
33 #include "runtime/globals.hpp"
34 #include "runtime/interfaceSupport.hpp"
35 #include "runtime/orderAccess.inline.hpp"
36 #include "runtime/reflection.hpp"
37 #include "runtime/vm_version.hpp"
38 #include "services/threadService.hpp"
39 #include "trace/tracing.hpp"
40 #include "utilities/copy.hpp"
41 #include "utilities/dtrace.hpp"
42 #include "utilities/macros.hpp"
43 #if INCLUDE_ALL_GCS
44 #include "gc/g1/g1SATBCardTableModRefBS.hpp"
45 #endif // INCLUDE_ALL_GCS
46
47 PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC
48
49 /*
50 * Implementation of class sun.misc.Unsafe
51 */
52
53
54 #define MAX_OBJECT_SIZE \
55 ( arrayOopDesc::header_size(T_DOUBLE) * HeapWordSize \
56 + ((julong)max_jint * sizeof(double)) )
57
58
59 #define UNSAFE_ENTRY(result_type, header) \
60 JVM_ENTRY(result_type, header)
61
62 // Can't use UNSAFE_LEAF because it has the signature of a straight
63 // call into the runtime (just like JVM_LEAF, funny that) but it's
64 // called like a Java Native and thus the wrapper built for it passes
65 // arguments like a JNI call. It expects those arguments to be popped
66 // from the stack on Intel like all good JNI args are, and adjusts the
67 // stack according. Since the JVM_LEAF call expects no extra
68 // arguments the stack isn't popped in the C code, is pushed by the
69 // wrapper and we get sick.
70 //#define UNSAFE_LEAF(result_type, header) \
71 // JVM_LEAF(result_type, header)
72
73 #define UNSAFE_END JVM_END
74
75 #define UnsafeWrapper(arg) /*nothing, for the present*/
76
77
78 inline void* addr_from_java(jlong addr) {
79 // This assert fails in a variety of ways on 32-bit systems.
80 // It is impossible to predict whether native code that converts
81 // pointers to longs will sign-extend or zero-extend the addresses.
82 //assert(addr == (uintptr_t)addr, "must not be odd high bits");
83 return (void*)(uintptr_t)addr;
84 }
85
86 inline jlong addr_to_java(void* p) {
87 assert(p == (void*)(uintptr_t)p, "must not be odd high bits");
88 return (uintptr_t)p;
89 }
90
91
92 // Note: The VM's obj_field and related accessors use byte-scaled
93 // ("unscaled") offsets, just as the unsafe methods do.
94
95 // However, the method Unsafe.fieldOffset explicitly declines to
96 // guarantee this. The field offset values manipulated by the Java user
97 // through the Unsafe API are opaque cookies that just happen to be byte
98 // offsets. We represent this state of affairs by passing the cookies
99 // through conversion functions when going between the VM and the Unsafe API.
100 // The conversion functions just happen to be no-ops at present.
101
102 inline jlong field_offset_to_byte_offset(jlong field_offset) {
103 return field_offset;
104 }
105
106 inline jlong field_offset_from_byte_offset(jlong byte_offset) {
107 return byte_offset;
108 }
109
110 inline jint invocation_key_from_method_slot(jint slot) {
111 return slot;
112 }
113
114 inline jint invocation_key_to_method_slot(jint key) {
115 return key;
116 }
117
118 inline void* index_oop_from_field_offset_long(oop p, jlong field_offset) {
119 jlong byte_offset = field_offset_to_byte_offset(field_offset);
120 #ifdef ASSERT
121 if (p != NULL) {
122 assert(byte_offset >= 0 && byte_offset <= (jlong)MAX_OBJECT_SIZE, "sane offset");
123 if (byte_offset == (jint)byte_offset) {
124 // We need to preemptively evacuate the object here to make the comparison
125 // in the assert below not give false negatives in case the object
126 // gets moved by concurrent threads while executing this code.
127 p = oopDesc::bs()->resolve_and_maybe_copy_oop(p);
128 void* ptr_plus_disp = (address)p + byte_offset;
129 assert((void*)p->obj_field_addr<oop>((jint)byte_offset) == ptr_plus_disp,
130 "raw [ptr+disp] must be consistent with oop::field_base");
131 }
132 jlong p_size = HeapWordSize * (jlong)(p->size());
133 assert(byte_offset < p_size, err_msg("Unsafe access: offset " INT64_FORMAT " > object's size " INT64_FORMAT, byte_offset, p_size));
134 }
135 #endif
136 if (sizeof(char*) == sizeof(jint)) // (this constant folds!)
137 return (address)p + (jint) byte_offset;
138 else
139 return (address)p + byte_offset;
140 }
141
142 // Externally callable versions:
143 // (Use these in compiler intrinsics which emulate unsafe primitives.)
144 jlong Unsafe_field_offset_to_byte_offset(jlong field_offset) {
145 return field_offset;
146 }
147 jlong Unsafe_field_offset_from_byte_offset(jlong byte_offset) {
148 return byte_offset;
149 }
150 jint Unsafe_invocation_key_from_method_slot(jint slot) {
151 return invocation_key_from_method_slot(slot);
152 }
153 jint Unsafe_invocation_key_to_method_slot(jint key) {
154 return invocation_key_to_method_slot(key);
155 }
156
157
158 ///// Data in the Java heap.
159
160 #define GET_FIELD(obj, offset, type_name, v) \
161 oop p = JNIHandles::resolve(obj); \
162 p = oopDesc::bs()->resolve_oop(p); \
163 type_name v = *(type_name*)index_oop_from_field_offset_long(p, offset)
164
165 #define SET_FIELD(obj, offset, type_name, x) \
166 oop p = JNIHandles::resolve(obj); \
167 p = oopDesc::bs()->resolve_and_maybe_copy_oop(p); \
168 *(type_name*)index_oop_from_field_offset_long(p, offset) = x
169
170 #define GET_FIELD_VOLATILE(obj, offset, type_name, v) \
171 oop p = JNIHandles::resolve(obj); \
172 p = oopDesc::bs()->resolve_oop(p); \
173 if (support_IRIW_for_not_multiple_copy_atomic_cpu) { \
174 OrderAccess::fence(); \
175 } \
176 volatile type_name v = OrderAccess::load_acquire((volatile type_name*)index_oop_from_field_offset_long(p, offset));
177
178 #define SET_FIELD_VOLATILE(obj, offset, type_name, x) \
179 oop p = JNIHandles::resolve(obj); \
180 p = oopDesc::bs()->resolve_and_maybe_copy_oop(p); \
181 OrderAccess::release_store_fence((volatile type_name*)index_oop_from_field_offset_long(p, offset), x);
182
183
184 // Get/SetObject must be special-cased, since it works with handles.
185
186 // These functions allow a null base pointer with an arbitrary address.
187 // But if the base pointer is non-null, the offset should make some sense.
188 // That is, it should be in the range [0, MAX_OBJECT_SIZE].
189 UNSAFE_ENTRY(jobject, Unsafe_GetObject(JNIEnv *env, jobject unsafe, jobject obj, jlong offset))
190 UnsafeWrapper("Unsafe_GetObject");
191 oop p = JNIHandles::resolve(obj);
192 p = oopDesc::bs()->resolve_oop(p);
193 oop v;
194 if (UseCompressedOops) {
195 narrowOop n = *(narrowOop*)index_oop_from_field_offset_long(p, offset);
196 v = oopDesc::decode_heap_oop(n);
197 } else {
198 v = *(oop*)index_oop_from_field_offset_long(p, offset);
199 }
200 jobject ret = JNIHandles::make_local(env, v);
201 #if INCLUDE_ALL_GCS
202 // We could be accessing the referent field in a reference
203 // object. If G1 is enabled then we need to register non-null
204 // referent with the SATB barrier.
205 if (UseG1GC || UseShenandoahGC) {
206 bool needs_barrier = false;
207
208 if (ret != NULL) {
209 if (offset == java_lang_ref_Reference::referent_offset && obj != NULL) {
210 oop o = JNIHandles::resolve(obj);
211 Klass* k = o->klass();
212 if (InstanceKlass::cast(k)->reference_type() != REF_NONE) {
213 assert(InstanceKlass::cast(k)->is_subclass_of(SystemDictionary::Reference_klass()), "sanity");
214 needs_barrier = true;
215 }
216 }
217 }
218
219 if (needs_barrier) {
220 oop referent = JNIHandles::resolve(ret);
221 G1SATBCardTableModRefBS::enqueue(referent);
222 }
223 }
224 #endif // INCLUDE_ALL_GCS
225 return ret;
226 UNSAFE_END
227
228 UNSAFE_ENTRY(void, Unsafe_SetObject(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jobject x_h))
229 UnsafeWrapper("Unsafe_SetObject");
230 oop x = oopDesc::bs()->resolve_oop(JNIHandles::resolve(x_h));
231 oop p = oopDesc::bs()->resolve_and_maybe_copy_oop(JNIHandles::resolve(obj));
232 if (UseCompressedOops) {
233 oop_store((narrowOop*)index_oop_from_field_offset_long(p, offset), x);
234 } else {
235 oop_store((oop*)index_oop_from_field_offset_long(p, offset), x);
236 }
237 UNSAFE_END
238
239 UNSAFE_ENTRY(jobject, Unsafe_GetObjectVolatile(JNIEnv *env, jobject unsafe, jobject obj, jlong offset))
240 UnsafeWrapper("Unsafe_GetObjectVolatile");
241 oop p = JNIHandles::resolve(obj);
242 p = oopDesc::bs()->resolve_oop(p);
243 void* addr = index_oop_from_field_offset_long(p, offset);
244 volatile oop v;
245 if (UseCompressedOops) {
246 volatile narrowOop n = *(volatile narrowOop*) addr;
247 (void)const_cast<oop&>(v = oopDesc::decode_heap_oop(n));
248 } else {
249 (void)const_cast<oop&>(v = *(volatile oop*) addr);
250 }
251 OrderAccess::acquire();
252 return JNIHandles::make_local(env, v);
253 UNSAFE_END
254
255 UNSAFE_ENTRY(void, Unsafe_SetObjectVolatile(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jobject x_h))
256 UnsafeWrapper("Unsafe_SetObjectVolatile");
257 oop x = JNIHandles::resolve(x_h);
258 oop p = JNIHandles::resolve(obj);
259 x = oopDesc::bs()->resolve_oop(x);
260 p = oopDesc::bs()->resolve_and_maybe_copy_oop(p);
261 void* addr = index_oop_from_field_offset_long(p, offset);
262 OrderAccess::release();
263 if (UseCompressedOops) {
264 oop_store((narrowOop*)addr, x);
265 } else {
266 oop_store((oop*)addr, x);
267 }
268 OrderAccess::fence();
269 UNSAFE_END
270
271 UNSAFE_ENTRY(jobject, Unsafe_GetUncompressedObject(JNIEnv *env, jobject unsafe, jlong addr))
272 UnsafeWrapper("Unsafe_GetUncompressedObject");
273 oop v = *(oop*) (address) addr;
274 return JNIHandles::make_local(env, v);
275 UNSAFE_END
276
277 UNSAFE_ENTRY(jclass, Unsafe_GetJavaMirror(JNIEnv *env, jobject unsafe, jlong metaspace_klass))
278 UnsafeWrapper("Unsafe_GetJavaMirror");
279 Klass* klass = (Klass*) (address) metaspace_klass;
280 return (jclass) JNIHandles::make_local(klass->java_mirror());
281 UNSAFE_END
282
283 UNSAFE_ENTRY(jlong, Unsafe_GetKlassPointer(JNIEnv *env, jobject unsafe, jobject obj))
284 UnsafeWrapper("Unsafe_GetKlassPointer");
285 oop o = JNIHandles::resolve(obj);
286 jlong klass = (jlong) (address) o->klass();
287 return klass;
288 UNSAFE_END
289
290 #ifndef SUPPORTS_NATIVE_CX8
291
292 // VM_Version::supports_cx8() is a surrogate for 'supports atomic long memory ops'.
293 //
294 // On platforms which do not support atomic compare-and-swap of jlong (8 byte)
295 // values we have to use a lock-based scheme to enforce atomicity. This has to be
296 // applied to all Unsafe operations that set the value of a jlong field. Even so
297 // the compareAndSwapLong operation will not be atomic with respect to direct stores
298 // to the field from Java code. It is important therefore that any Java code that
299 // utilizes these Unsafe jlong operations does not perform direct stores. To permit
300 // direct loads of the field from Java code we must also use Atomic::store within the
301 // locked regions. And for good measure, in case there are direct stores, we also
302 // employ Atomic::load within those regions. Note that the field in question must be
303 // volatile and so must have atomic load/store accesses applied at the Java level.
304 //
305 // The locking scheme could utilize a range of strategies for controlling the locking
306 // granularity: from a lock per-field through to a single global lock. The latter is
307 // the simplest and is used for the current implementation. Note that the Java object
308 // that contains the field, can not, in general, be used for locking. To do so can lead
309 // to deadlocks as we may introduce locking into what appears to the Java code to be a
310 // lock-free path.
311 //
312 // As all the locked-regions are very short and themselves non-blocking we can treat
313 // them as leaf routines and elide safepoint checks (ie we don't perform any thread
314 // state transitions even when blocking for the lock). Note that if we do choose to
315 // add safepoint checks and thread state transitions, we must ensure that we calculate
316 // the address of the field _after_ we have acquired the lock, else the object may have
317 // been moved by the GC
318
319 UNSAFE_ENTRY(jlong, Unsafe_GetLongVolatile(JNIEnv *env, jobject unsafe, jobject obj, jlong offset))
320 UnsafeWrapper("Unsafe_GetLongVolatile");
321 {
322 if (VM_Version::supports_cx8()) {
323 GET_FIELD_VOLATILE(obj, offset, jlong, v);
324 return v;
325 }
326 else {
327 Handle p (THREAD, oopDesc::bs()->resolve_oop(JNIHandles::resolve(obj)));
328 jlong* addr = (jlong*)(index_oop_from_field_offset_long(p(), offset));
329 MutexLockerEx mu(UnsafeJlong_lock, Mutex::_no_safepoint_check_flag);
330 jlong value = Atomic::load(addr);
331 return value;
332 }
333 }
334 UNSAFE_END
335
336 UNSAFE_ENTRY(void, Unsafe_SetLongVolatile(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jlong x))
337 UnsafeWrapper("Unsafe_SetLongVolatile");
338 {
339 if (VM_Version::supports_cx8()) {
340 SET_FIELD_VOLATILE(obj, offset, jlong, x);
341 }
342 else {
343 Handle p (THREAD, oopDesc::bs()->resolve_and_maybe_copy_oop(JNIHandles::resolve(obj)));
344 jlong* addr = (jlong*)(index_oop_from_field_offset_long(p(), offset));
345 MutexLockerEx mu(UnsafeJlong_lock, Mutex::_no_safepoint_check_flag);
346 Atomic::store(x, addr);
347 }
348 }
349 UNSAFE_END
350
351 #endif // not SUPPORTS_NATIVE_CX8
352
353 UNSAFE_ENTRY(jboolean, Unsafe_isBigEndian0(JNIEnv *env, jobject unsafe))
354 UnsafeWrapper("Unsafe_IsBigEndian0");
355 {
356 #ifdef VM_LITTLE_ENDIAN
357 return false;
358 #else
359 return true;
360 #endif
361 }
362 UNSAFE_END
363
364 UNSAFE_ENTRY(jint, Unsafe_unalignedAccess0(JNIEnv *env, jobject unsafe))
365 UnsafeWrapper("Unsafe_UnalignedAccess0");
366 {
367 return UseUnalignedAccesses;
368 }
369 UNSAFE_END
370
371 #define DEFINE_GETSETOOP(jboolean, Boolean) \
372 \
373 UNSAFE_ENTRY(jboolean, Unsafe_Get##Boolean##140(JNIEnv *env, jobject unsafe, jobject obj, jint offset)) \
374 UnsafeWrapper("Unsafe_Get"#Boolean); \
375 if (obj == NULL) THROW_0(vmSymbols::java_lang_NullPointerException()); \
376 GET_FIELD(obj, offset, jboolean, v); \
377 return v; \
378 UNSAFE_END \
379 \
380 UNSAFE_ENTRY(void, Unsafe_Set##Boolean##140(JNIEnv *env, jobject unsafe, jobject obj, jint offset, jboolean x)) \
381 UnsafeWrapper("Unsafe_Set"#Boolean); \
382 if (obj == NULL) THROW(vmSymbols::java_lang_NullPointerException()); \
383 SET_FIELD(obj, offset, jboolean, x); \
384 UNSAFE_END \
385 \
386 UNSAFE_ENTRY(jboolean, Unsafe_Get##Boolean(JNIEnv *env, jobject unsafe, jobject obj, jlong offset)) \
387 UnsafeWrapper("Unsafe_Get"#Boolean); \
388 GET_FIELD(obj, offset, jboolean, v); \
389 return v; \
390 UNSAFE_END \
391 \
392 UNSAFE_ENTRY(void, Unsafe_Set##Boolean(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jboolean x)) \
393 UnsafeWrapper("Unsafe_Set"#Boolean); \
394 SET_FIELD(obj, offset, jboolean, x); \
395 UNSAFE_END \
396 \
397 // END DEFINE_GETSETOOP.
398
399 DEFINE_GETSETOOP(jboolean, Boolean)
400 DEFINE_GETSETOOP(jbyte, Byte)
401 DEFINE_GETSETOOP(jshort, Short);
402 DEFINE_GETSETOOP(jchar, Char);
403 DEFINE_GETSETOOP(jint, Int);
404 DEFINE_GETSETOOP(jlong, Long);
405 DEFINE_GETSETOOP(jfloat, Float);
406 DEFINE_GETSETOOP(jdouble, Double);
407
408 #undef DEFINE_GETSETOOP
409
410 #define DEFINE_GETSETOOP_VOLATILE(jboolean, Boolean) \
411 \
412 UNSAFE_ENTRY(jboolean, Unsafe_Get##Boolean##Volatile(JNIEnv *env, jobject unsafe, jobject obj, jlong offset)) \
413 UnsafeWrapper("Unsafe_Get"#Boolean); \
414 GET_FIELD_VOLATILE(obj, offset, jboolean, v); \
415 return v; \
416 UNSAFE_END \
417 \
418 UNSAFE_ENTRY(void, Unsafe_Set##Boolean##Volatile(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jboolean x)) \
419 UnsafeWrapper("Unsafe_Set"#Boolean); \
420 SET_FIELD_VOLATILE(obj, offset, jboolean, x); \
421 UNSAFE_END \
422 \
423 // END DEFINE_GETSETOOP_VOLATILE.
424
425 DEFINE_GETSETOOP_VOLATILE(jboolean, Boolean)
426 DEFINE_GETSETOOP_VOLATILE(jbyte, Byte)
427 DEFINE_GETSETOOP_VOLATILE(jshort, Short);
428 DEFINE_GETSETOOP_VOLATILE(jchar, Char);
429 DEFINE_GETSETOOP_VOLATILE(jint, Int);
430 DEFINE_GETSETOOP_VOLATILE(jfloat, Float);
431 DEFINE_GETSETOOP_VOLATILE(jdouble, Double);
432
433 #ifdef SUPPORTS_NATIVE_CX8
434 DEFINE_GETSETOOP_VOLATILE(jlong, Long);
435 #endif
436
437 #undef DEFINE_GETSETOOP_VOLATILE
438
439 // The non-intrinsified versions of setOrdered just use setVolatile
440
441 UNSAFE_ENTRY(void, Unsafe_SetOrderedInt(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jint x))
442 UnsafeWrapper("Unsafe_SetOrderedInt");
443 SET_FIELD_VOLATILE(obj, offset, jint, x);
444 UNSAFE_END
445
446 UNSAFE_ENTRY(void, Unsafe_SetOrderedObject(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jobject x_h))
447 UnsafeWrapper("Unsafe_SetOrderedObject");
448 oop x = JNIHandles::resolve(x_h);
449 oop p = JNIHandles::resolve(obj);
450 x = oopDesc::bs()->resolve_oop(x);
451 p = oopDesc::bs()->resolve_and_maybe_copy_oop(p);
452 void* addr = index_oop_from_field_offset_long(p, offset);
453 OrderAccess::release();
454 if (UseCompressedOops) {
455 oop_store((narrowOop*)addr, x);
456 } else {
457 oop_store((oop*)addr, x);
458 }
459 OrderAccess::fence();
460 UNSAFE_END
461
462 UNSAFE_ENTRY(void, Unsafe_SetOrderedLong(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jlong x))
463 UnsafeWrapper("Unsafe_SetOrderedLong");
464 #ifdef SUPPORTS_NATIVE_CX8
465 SET_FIELD_VOLATILE(obj, offset, jlong, x);
466 #else
467 // Keep old code for platforms which may not have atomic long (8 bytes) instructions
468 {
469 if (VM_Version::supports_cx8()) {
470 SET_FIELD_VOLATILE(obj, offset, jlong, x);
471 }
472 else {
473 Handle p (THREAD, oopDesc::bs()->resolve_and_maybe_copy_oop(JNIHandles::resolve(obj)));
474 jlong* addr = (jlong*)(index_oop_from_field_offset_long(p(), offset));
475 MutexLockerEx mu(UnsafeJlong_lock, Mutex::_no_safepoint_check_flag);
476 Atomic::store(x, addr);
477 }
478 }
479 #endif
480 UNSAFE_END
481
482 UNSAFE_ENTRY(void, Unsafe_LoadFence(JNIEnv *env, jobject unsafe))
483 UnsafeWrapper("Unsafe_LoadFence");
484 OrderAccess::acquire();
485 UNSAFE_END
486
487 UNSAFE_ENTRY(void, Unsafe_StoreFence(JNIEnv *env, jobject unsafe))
488 UnsafeWrapper("Unsafe_StoreFence");
489 OrderAccess::release();
490 UNSAFE_END
491
492 UNSAFE_ENTRY(void, Unsafe_FullFence(JNIEnv *env, jobject unsafe))
493 UnsafeWrapper("Unsafe_FullFence");
494 OrderAccess::fence();
495 UNSAFE_END
496
497 ////// Data in the C heap.
498
499 // Note: These do not throw NullPointerException for bad pointers.
500 // They just crash. Only a oop base pointer can generate a NullPointerException.
501 //
502 #define DEFINE_GETSETNATIVE(java_type, Type, native_type) \
503 \
504 UNSAFE_ENTRY(java_type, Unsafe_GetNative##Type(JNIEnv *env, jobject unsafe, jlong addr)) \
505 UnsafeWrapper("Unsafe_GetNative"#Type); \
506 void* p = addr_from_java(addr); \
507 JavaThread* t = JavaThread::current(); \
508 t->set_doing_unsafe_access(true); \
509 java_type x = *(volatile native_type*)p; \
510 t->set_doing_unsafe_access(false); \
511 return x; \
512 UNSAFE_END \
513 \
514 UNSAFE_ENTRY(void, Unsafe_SetNative##Type(JNIEnv *env, jobject unsafe, jlong addr, java_type x)) \
515 UnsafeWrapper("Unsafe_SetNative"#Type); \
516 JavaThread* t = JavaThread::current(); \
517 t->set_doing_unsafe_access(true); \
518 void* p = addr_from_java(addr); \
519 *(volatile native_type*)p = x; \
520 t->set_doing_unsafe_access(false); \
521 UNSAFE_END \
522 \
523 // END DEFINE_GETSETNATIVE.
524
525 DEFINE_GETSETNATIVE(jbyte, Byte, signed char)
526 DEFINE_GETSETNATIVE(jshort, Short, signed short);
527 DEFINE_GETSETNATIVE(jchar, Char, unsigned short);
528 DEFINE_GETSETNATIVE(jint, Int, jint);
529 // no long -- handled specially
530 DEFINE_GETSETNATIVE(jfloat, Float, float);
531 DEFINE_GETSETNATIVE(jdouble, Double, double);
532
533 #undef DEFINE_GETSETNATIVE
534
535 UNSAFE_ENTRY(jlong, Unsafe_GetNativeLong(JNIEnv *env, jobject unsafe, jlong addr))
536 UnsafeWrapper("Unsafe_GetNativeLong");
537 JavaThread* t = JavaThread::current();
538 // We do it this way to avoid problems with access to heap using 64
539 // bit loads, as jlong in heap could be not 64-bit aligned, and on
540 // some CPUs (SPARC) it leads to SIGBUS.
541 t->set_doing_unsafe_access(true);
542 void* p = addr_from_java(addr);
543 jlong x;
544 if (((intptr_t)p & 7) == 0) {
545 // jlong is aligned, do a volatile access
546 x = *(volatile jlong*)p;
547 } else {
548 jlong_accessor acc;
549 acc.words[0] = ((volatile jint*)p)[0];
550 acc.words[1] = ((volatile jint*)p)[1];
551 x = acc.long_value;
552 }
553 t->set_doing_unsafe_access(false);
554 return x;
555 UNSAFE_END
556
557 UNSAFE_ENTRY(void, Unsafe_SetNativeLong(JNIEnv *env, jobject unsafe, jlong addr, jlong x))
558 UnsafeWrapper("Unsafe_SetNativeLong");
559 JavaThread* t = JavaThread::current();
560 // see comment for Unsafe_GetNativeLong
561 t->set_doing_unsafe_access(true);
562 void* p = addr_from_java(addr);
563 if (((intptr_t)p & 7) == 0) {
564 // jlong is aligned, do a volatile access
565 *(volatile jlong*)p = x;
566 } else {
567 jlong_accessor acc;
568 acc.long_value = x;
569 ((volatile jint*)p)[0] = acc.words[0];
570 ((volatile jint*)p)[1] = acc.words[1];
571 }
572 t->set_doing_unsafe_access(false);
573 UNSAFE_END
574
575
576 UNSAFE_ENTRY(jlong, Unsafe_GetNativeAddress(JNIEnv *env, jobject unsafe, jlong addr))
577 UnsafeWrapper("Unsafe_GetNativeAddress");
578 void* p = addr_from_java(addr);
579 return addr_to_java(*(void**)p);
580 UNSAFE_END
581
582 UNSAFE_ENTRY(void, Unsafe_SetNativeAddress(JNIEnv *env, jobject unsafe, jlong addr, jlong x))
583 UnsafeWrapper("Unsafe_SetNativeAddress");
584 void* p = addr_from_java(addr);
585 *(void**)p = addr_from_java(x);
586 UNSAFE_END
587
588
589 ////// Allocation requests
590
591 UNSAFE_ENTRY(jobject, Unsafe_AllocateInstance(JNIEnv *env, jobject unsafe, jclass cls))
592 UnsafeWrapper("Unsafe_AllocateInstance");
593 {
594 ThreadToNativeFromVM ttnfv(thread);
595 return env->AllocObject(cls);
596 }
597 UNSAFE_END
598
599 UNSAFE_ENTRY(jlong, Unsafe_AllocateMemory(JNIEnv *env, jobject unsafe, jlong size))
600 UnsafeWrapper("Unsafe_AllocateMemory");
601 size_t sz = (size_t)size;
602 if (sz != (julong)size || size < 0) {
603 THROW_0(vmSymbols::java_lang_IllegalArgumentException());
604 }
605 if (sz == 0) {
606 return 0;
607 }
608 sz = round_to(sz, HeapWordSize);
609 void* x = os::malloc(sz, mtInternal);
610 if (x == NULL) {
611 THROW_0(vmSymbols::java_lang_OutOfMemoryError());
612 }
613 //Copy::fill_to_words((HeapWord*)x, sz / HeapWordSize);
614 return addr_to_java(x);
615 UNSAFE_END
616
617 UNSAFE_ENTRY(jlong, Unsafe_ReallocateMemory(JNIEnv *env, jobject unsafe, jlong addr, jlong size))
618 UnsafeWrapper("Unsafe_ReallocateMemory");
619 void* p = addr_from_java(addr);
620 size_t sz = (size_t)size;
621 if (sz != (julong)size || size < 0) {
622 THROW_0(vmSymbols::java_lang_IllegalArgumentException());
623 }
624 if (sz == 0) {
625 os::free(p);
626 return 0;
627 }
628 sz = round_to(sz, HeapWordSize);
629 void* x = (p == NULL) ? os::malloc(sz, mtInternal) : os::realloc(p, sz, mtInternal);
630 if (x == NULL) {
631 THROW_0(vmSymbols::java_lang_OutOfMemoryError());
632 }
633 return addr_to_java(x);
634 UNSAFE_END
635
636 UNSAFE_ENTRY(void, Unsafe_FreeMemory(JNIEnv *env, jobject unsafe, jlong addr))
637 UnsafeWrapper("Unsafe_FreeMemory");
638 void* p = addr_from_java(addr);
639 if (p == NULL) {
640 return;
641 }
642 os::free(p);
643 UNSAFE_END
644
645 UNSAFE_ENTRY(void, Unsafe_SetMemory(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jlong size, jbyte value))
646 UnsafeWrapper("Unsafe_SetMemory");
647 size_t sz = (size_t)size;
648 if (sz != (julong)size || size < 0) {
649 THROW(vmSymbols::java_lang_IllegalArgumentException());
650 }
651 oop base = JNIHandles::resolve(obj);
652 base = oopDesc::bs()->resolve_and_maybe_copy_oop(base);
653 void* p = index_oop_from_field_offset_long(base, offset);
654 Copy::fill_to_memory_atomic(p, sz, value);
655 UNSAFE_END
656
657 UNSAFE_ENTRY(void, Unsafe_CopyMemory(JNIEnv *env, jobject unsafe, jobject srcObj, jlong srcOffset, jobject dstObj, jlong dstOffset, jlong size))
658 UnsafeWrapper("Unsafe_CopyMemory");
659 if (size == 0) {
660 return;
661 }
662 size_t sz = (size_t)size;
663 if (sz != (julong)size || size < 0) {
664 THROW(vmSymbols::java_lang_IllegalArgumentException());
665 }
666 oop srcp = JNIHandles::resolve(srcObj);
667 oop dstp = JNIHandles::resolve(dstObj);
668 srcp = oopDesc::bs()->resolve_oop(srcp);
669 dstp = oopDesc::bs()->resolve_and_maybe_copy_oop(dstp);
670 if (dstp != NULL && !dstp->is_typeArray()) {
671 // NYI: This works only for non-oop arrays at present.
672 // Generalizing it would be reasonable, but requires card marking.
673 // Also, autoboxing a Long from 0L in copyMemory(x,y, 0L,z, n) would be bad.
674 THROW(vmSymbols::java_lang_IllegalArgumentException());
675 }
676 void* src = index_oop_from_field_offset_long(srcp, srcOffset);
677 void* dst = index_oop_from_field_offset_long(dstp, dstOffset);
678 Copy::conjoint_memory_atomic(src, dst, sz);
679 UNSAFE_END
680
681
682 ////// Random queries
683
684 // See comment at file start about UNSAFE_LEAF
685 //UNSAFE_LEAF(jint, Unsafe_AddressSize())
686 UNSAFE_ENTRY(jint, Unsafe_AddressSize(JNIEnv *env, jobject unsafe))
687 UnsafeWrapper("Unsafe_AddressSize");
688 return sizeof(void*);
689 UNSAFE_END
690
691 // See comment at file start about UNSAFE_LEAF
692 //UNSAFE_LEAF(jint, Unsafe_PageSize())
693 UNSAFE_ENTRY(jint, Unsafe_PageSize(JNIEnv *env, jobject unsafe))
694 UnsafeWrapper("Unsafe_PageSize");
695 return os::vm_page_size();
696 UNSAFE_END
697
698 jint find_field_offset(jobject field, int must_be_static, TRAPS) {
699 if (field == NULL) {
700 THROW_0(vmSymbols::java_lang_NullPointerException());
701 }
702
703 oop reflected = JNIHandles::resolve_non_null(field);
704 oop mirror = java_lang_reflect_Field::clazz(reflected);
705 Klass* k = java_lang_Class::as_Klass(mirror);
706 int slot = java_lang_reflect_Field::slot(reflected);
707 int modifiers = java_lang_reflect_Field::modifiers(reflected);
708
709 if (must_be_static >= 0) {
710 int really_is_static = ((modifiers & JVM_ACC_STATIC) != 0);
711 if (must_be_static != really_is_static) {
712 THROW_0(vmSymbols::java_lang_IllegalArgumentException());
713 }
714 }
715
716 int offset = InstanceKlass::cast(k)->field_offset(slot);
717 return field_offset_from_byte_offset(offset);
718 }
719
720 UNSAFE_ENTRY(jlong, Unsafe_ObjectFieldOffset(JNIEnv *env, jobject unsafe, jobject field))
721 UnsafeWrapper("Unsafe_ObjectFieldOffset");
722 return find_field_offset(field, 0, THREAD);
723 UNSAFE_END
724
725 UNSAFE_ENTRY(jlong, Unsafe_StaticFieldOffset(JNIEnv *env, jobject unsafe, jobject field))
726 UnsafeWrapper("Unsafe_StaticFieldOffset");
727 return find_field_offset(field, 1, THREAD);
728 UNSAFE_END
729
730 UNSAFE_ENTRY(jobject, Unsafe_StaticFieldBaseFromField(JNIEnv *env, jobject unsafe, jobject field))
731 UnsafeWrapper("Unsafe_StaticFieldBase");
732 // Note: In this VM implementation, a field address is always a short
733 // offset from the base of a a klass metaobject. Thus, the full dynamic
734 // range of the return type is never used. However, some implementations
735 // might put the static field inside an array shared by many classes,
736 // or even at a fixed address, in which case the address could be quite
737 // large. In that last case, this function would return NULL, since
738 // the address would operate alone, without any base pointer.
739
740 if (field == NULL) THROW_0(vmSymbols::java_lang_NullPointerException());
741
742 oop reflected = JNIHandles::resolve_non_null(field);
743 oop mirror = java_lang_reflect_Field::clazz(reflected);
744 int modifiers = java_lang_reflect_Field::modifiers(reflected);
745
746 if ((modifiers & JVM_ACC_STATIC) == 0) {
747 THROW_0(vmSymbols::java_lang_IllegalArgumentException());
748 }
749
750 return JNIHandles::make_local(env, mirror);
751 UNSAFE_END
752
753 UNSAFE_ENTRY(void, Unsafe_EnsureClassInitialized(JNIEnv *env, jobject unsafe, jobject clazz)) {
754 UnsafeWrapper("Unsafe_EnsureClassInitialized");
755 if (clazz == NULL) {
756 THROW(vmSymbols::java_lang_NullPointerException());
757 }
758 oop mirror = JNIHandles::resolve_non_null(clazz);
759
760 Klass* klass = java_lang_Class::as_Klass(mirror);
761 if (klass != NULL && klass->should_be_initialized()) {
762 InstanceKlass* k = InstanceKlass::cast(klass);
763 k->initialize(CHECK);
764 }
765 }
766 UNSAFE_END
767
768 UNSAFE_ENTRY(jboolean, Unsafe_ShouldBeInitialized(JNIEnv *env, jobject unsafe, jobject clazz)) {
769 UnsafeWrapper("Unsafe_ShouldBeInitialized");
770 if (clazz == NULL) {
771 THROW_(vmSymbols::java_lang_NullPointerException(), false);
772 }
773 oop mirror = JNIHandles::resolve_non_null(clazz);
774 Klass* klass = java_lang_Class::as_Klass(mirror);
775 if (klass != NULL && klass->should_be_initialized()) {
776 return true;
777 }
778 return false;
779 }
780 UNSAFE_END
781
782 static void getBaseAndScale(int& base, int& scale, jclass acls, TRAPS) {
783 if (acls == NULL) {
784 THROW(vmSymbols::java_lang_NullPointerException());
785 }
786 oop mirror = JNIHandles::resolve_non_null(acls);
787 Klass* k = java_lang_Class::as_Klass(mirror);
788 if (k == NULL || !k->oop_is_array()) {
789 THROW(vmSymbols::java_lang_InvalidClassException());
790 } else if (k->oop_is_objArray()) {
791 base = arrayOopDesc::base_offset_in_bytes(T_OBJECT);
792 scale = heapOopSize;
793 } else if (k->oop_is_typeArray()) {
794 TypeArrayKlass* tak = TypeArrayKlass::cast(k);
795 base = tak->array_header_in_bytes();
796 assert(base == arrayOopDesc::base_offset_in_bytes(tak->element_type()), "array_header_size semantics ok");
797 scale = (1 << tak->log2_element_size());
798 } else {
799 ShouldNotReachHere();
800 }
801 }
802
803 UNSAFE_ENTRY(jint, Unsafe_ArrayBaseOffset(JNIEnv *env, jobject unsafe, jclass acls))
804 UnsafeWrapper("Unsafe_ArrayBaseOffset");
805 int base, scale;
806 getBaseAndScale(base, scale, acls, CHECK_0);
807 return field_offset_from_byte_offset(base);
808 UNSAFE_END
809
810
811 UNSAFE_ENTRY(jint, Unsafe_ArrayIndexScale(JNIEnv *env, jobject unsafe, jclass acls))
812 UnsafeWrapper("Unsafe_ArrayIndexScale");
813 int base, scale;
814 getBaseAndScale(base, scale, acls, CHECK_0);
815 // This VM packs both fields and array elements down to the byte.
816 // But watch out: If this changes, so that array references for
817 // a given primitive type (say, T_BOOLEAN) use different memory units
818 // than fields, this method MUST return zero for such arrays.
819 // For example, the VM used to store sub-word sized fields in full
820 // words in the object layout, so that accessors like getByte(Object,int)
821 // did not really do what one might expect for arrays. Therefore,
822 // this function used to report a zero scale factor, so that the user
823 // would know not to attempt to access sub-word array elements.
824 // // Code for unpacked fields:
825 // if (scale < wordSize) return 0;
826
827 // The following allows for a pretty general fieldOffset cookie scheme,
828 // but requires it to be linear in byte offset.
829 return field_offset_from_byte_offset(scale) - field_offset_from_byte_offset(0);
830 UNSAFE_END
831
832
833 static inline void throw_new(JNIEnv *env, const char *ename) {
834 char buf[100];
835 jio_snprintf(buf, 100, "%s%s", "java/lang/", ename);
836 jclass cls = env->FindClass(buf);
837 if (env->ExceptionCheck()) {
838 env->ExceptionClear();
839 tty->print_cr("Unsafe: cannot throw %s because FindClass has failed", buf);
840 return;
841 }
842 char* msg = NULL;
843 env->ThrowNew(cls, msg);
844 }
845
846 static jclass Unsafe_DefineClass_impl(JNIEnv *env, jstring name, jbyteArray data, int offset, int length, jobject loader, jobject pd) {
847 {
848 // Code lifted from JDK 1.3 ClassLoader.c
849
850 jbyte *body;
851 char *utfName;
852 jclass result = 0;
853 char buf[128];
854
855 if (UsePerfData) {
856 ClassLoader::unsafe_defineClassCallCounter()->inc();
857 }
858
859 if (data == NULL) {
860 throw_new(env, "NullPointerException");
861 return 0;
862 }
863
864 /* Work around 4153825. malloc crashes on Solaris when passed a
865 * negative size.
866 */
867 if (length < 0) {
868 throw_new(env, "ArrayIndexOutOfBoundsException");
869 return 0;
870 }
871
872 body = NEW_C_HEAP_ARRAY(jbyte, length, mtInternal);
873
874 if (body == 0) {
875 throw_new(env, "OutOfMemoryError");
876 return 0;
877 }
878
879 env->GetByteArrayRegion(data, offset, length, body);
880
881 if (env->ExceptionOccurred())
882 goto free_body;
883
884 if (name != NULL) {
885 uint len = env->GetStringUTFLength(name);
886 int unicode_len = env->GetStringLength(name);
887 if (len >= sizeof(buf)) {
888 utfName = NEW_C_HEAP_ARRAY(char, len + 1, mtInternal);
889 if (utfName == NULL) {
890 throw_new(env, "OutOfMemoryError");
891 goto free_body;
892 }
893 } else {
894 utfName = buf;
895 }
896 env->GetStringUTFRegion(name, 0, unicode_len, utfName);
897 //VerifyFixClassname(utfName);
898 for (uint i = 0; i < len; i++) {
899 if (utfName[i] == '.') utfName[i] = '/';
900 }
901 } else {
902 utfName = NULL;
903 }
904
905 result = JVM_DefineClass(env, utfName, loader, body, length, pd);
906
907 if (utfName && utfName != buf)
908 FREE_C_HEAP_ARRAY(char, utfName);
909
910 free_body:
911 FREE_C_HEAP_ARRAY(jbyte, body);
912 return result;
913 }
914 }
915
916
917 UNSAFE_ENTRY(jclass, Unsafe_DefineClass(JNIEnv *env, jobject unsafe, jstring name, jbyteArray data, int offset, int length, jobject loader, jobject pd))
918 UnsafeWrapper("Unsafe_DefineClass");
919 {
920 ThreadToNativeFromVM ttnfv(thread);
921 return Unsafe_DefineClass_impl(env, name, data, offset, length, loader, pd);
922 }
923 UNSAFE_END
924
925
926 // define a class but do not make it known to the class loader or system dictionary
927 // - host_class: supplies context for linkage, access control, protection domain, and class loader
928 // - data: bytes of a class file, a raw memory address (length gives the number of bytes)
929 // - cp_patches: where non-null entries exist, they replace corresponding CP entries in data
930
931 // When you load an anonymous class U, it works as if you changed its name just before loading,
932 // to a name that you will never use again. Since the name is lost, no other class can directly
933 // link to any member of U. Just after U is loaded, the only way to use it is reflectively,
934 // through java.lang.Class methods like Class.newInstance.
935
936 // Access checks for linkage sites within U continue to follow the same rules as for named classes.
937 // The package of an anonymous class is given by the package qualifier on the name under which it was loaded.
938 // An anonymous class also has special privileges to access any member of its host class.
939 // This is the main reason why this loading operation is unsafe. The purpose of this is to
940 // allow language implementations to simulate "open classes"; a host class in effect gets
941 // new code when an anonymous class is loaded alongside it. A less convenient but more
942 // standard way to do this is with reflection, which can also be set to ignore access
943 // restrictions.
944
945 // Access into an anonymous class is possible only through reflection. Therefore, there
946 // are no special access rules for calling into an anonymous class. The relaxed access
947 // rule for the host class is applied in the opposite direction: A host class reflectively
948 // access one of its anonymous classes.
949
950 // If you load the same bytecodes twice, you get two different classes. You can reload
951 // the same bytecodes with or without varying CP patches.
952
953 // By using the CP patching array, you can have a new anonymous class U2 refer to an older one U1.
954 // The bytecodes for U2 should refer to U1 by a symbolic name (doesn't matter what the name is).
955 // The CONSTANT_Class entry for that name can be patched to refer directly to U1.
956
957 // This allows, for example, U2 to use U1 as a superclass or super-interface, or as
958 // an outer class (so that U2 is an anonymous inner class of anonymous U1).
959 // It is not possible for a named class, or an older anonymous class, to refer by
960 // name (via its CP) to a newer anonymous class.
961
962 // CP patching may also be used to modify (i.e., hack) the names of methods, classes,
963 // or type descriptors used in the loaded anonymous class.
964
965 // Finally, CP patching may be used to introduce "live" objects into the constant pool,
966 // instead of "dead" strings. A compiled statement like println((Object)"hello") can
967 // be changed to println(greeting), where greeting is an arbitrary object created before
968 // the anonymous class is loaded. This is useful in dynamic languages, in which
969 // various kinds of metaobjects must be introduced as constants into bytecode.
970 // Note the cast (Object), which tells the verifier to expect an arbitrary object,
971 // not just a literal string. For such ldc instructions, the verifier uses the
972 // type Object instead of String, if the loaded constant is not in fact a String.
973
974 static instanceKlassHandle
975 Unsafe_DefineAnonymousClass_impl(JNIEnv *env,
976 jclass host_class, jbyteArray data, jobjectArray cp_patches_jh,
977 HeapWord* *temp_alloc,
978 TRAPS) {
979
980 if (UsePerfData) {
981 ClassLoader::unsafe_defineClassCallCounter()->inc();
982 }
983
984 if (data == NULL) {
985 THROW_0(vmSymbols::java_lang_NullPointerException());
986 }
987
988 jint length = typeArrayOop(JNIHandles::resolve_non_null(data))->length();
989 jint word_length = (length + sizeof(HeapWord)-1) / sizeof(HeapWord);
990 HeapWord* body = NEW_C_HEAP_ARRAY(HeapWord, word_length, mtInternal);
991 if (body == NULL) {
992 THROW_0(vmSymbols::java_lang_OutOfMemoryError());
993 }
994
995 // caller responsible to free it:
996 (*temp_alloc) = body;
997
998 {
999 jbyte* array_base = typeArrayOop(JNIHandles::resolve_non_null(data))->byte_at_addr(0);
1000 Copy::conjoint_words((HeapWord*) array_base, body, word_length);
1001 }
1002
1003 u1* class_bytes = (u1*) body;
1004 int class_bytes_length = (int) length;
1005 if (class_bytes_length < 0) class_bytes_length = 0;
1006 if (class_bytes == NULL
1007 || host_class == NULL
1008 || length != class_bytes_length)
1009 THROW_0(vmSymbols::java_lang_IllegalArgumentException());
1010
1011 objArrayHandle cp_patches_h;
1012 if (cp_patches_jh != NULL) {
1013 oop p = JNIHandles::resolve_non_null(cp_patches_jh);
1014 if (!p->is_objArray())
1015 THROW_0(vmSymbols::java_lang_IllegalArgumentException());
1016 cp_patches_h = objArrayHandle(THREAD, (objArrayOop)p);
1017 }
1018
1019 KlassHandle host_klass(THREAD, java_lang_Class::as_Klass(JNIHandles::resolve_non_null(host_class)));
1020 const char* host_source = host_klass->external_name();
1021 Handle host_loader(THREAD, host_klass->class_loader());
1022 Handle host_domain(THREAD, host_klass->protection_domain());
1023
1024 GrowableArray<Handle>* cp_patches = NULL;
1025 if (cp_patches_h.not_null()) {
1026 int alen = cp_patches_h->length();
1027 for (int i = alen-1; i >= 0; i--) {
1028 oop p = cp_patches_h->obj_at(i);
1029 if (p != NULL) {
1030 Handle patch(THREAD, p);
1031 if (cp_patches == NULL)
1032 cp_patches = new GrowableArray<Handle>(i+1, i+1, Handle());
1033 cp_patches->at_put(i, patch);
1034 }
1035 }
1036 }
1037
1038 ClassFileStream st(class_bytes, class_bytes_length, (char*) host_source);
1039
1040 instanceKlassHandle anon_klass;
1041 {
1042 Symbol* no_class_name = NULL;
1043 Klass* anonk = SystemDictionary::parse_stream(no_class_name,
1044 host_loader, host_domain,
1045 &st, host_klass, cp_patches,
1046 CHECK_NULL);
1047 if (anonk == NULL) return NULL;
1048 anon_klass = instanceKlassHandle(THREAD, anonk);
1049 }
1050
1051 return anon_klass;
1052 }
1053
1054 UNSAFE_ENTRY(jclass, Unsafe_DefineAnonymousClass(JNIEnv *env, jobject unsafe, jclass host_class, jbyteArray data, jobjectArray cp_patches_jh))
1055 {
1056 instanceKlassHandle anon_klass;
1057 jobject res_jh = NULL;
1058
1059 UnsafeWrapper("Unsafe_DefineAnonymousClass");
1060 ResourceMark rm(THREAD);
1061
1062 HeapWord* temp_alloc = NULL;
1063
1064 anon_klass = Unsafe_DefineAnonymousClass_impl(env, host_class, data,
1065 cp_patches_jh,
1066 &temp_alloc, THREAD);
1067 if (anon_klass() != NULL)
1068 res_jh = JNIHandles::make_local(env, anon_klass->java_mirror());
1069
1070 // try/finally clause:
1071 if (temp_alloc != NULL) {
1072 FREE_C_HEAP_ARRAY(HeapWord, temp_alloc);
1073 }
1074
1075 // The anonymous class loader data has been artificially been kept alive to
1076 // this point. The mirror and any instances of this class have to keep
1077 // it alive afterwards.
1078 if (anon_klass() != NULL) {
1079 anon_klass->class_loader_data()->set_keep_alive(false);
1080 }
1081
1082 // let caller initialize it as needed...
1083
1084 return (jclass) res_jh;
1085 }
1086 UNSAFE_END
1087
1088
1089
1090 UNSAFE_ENTRY(void, Unsafe_ThrowException(JNIEnv *env, jobject unsafe, jthrowable thr))
1091 UnsafeWrapper("Unsafe_ThrowException");
1092 {
1093 ThreadToNativeFromVM ttnfv(thread);
1094 env->Throw(thr);
1095 }
1096 UNSAFE_END
1097
1098 // JSR166 ------------------------------------------------------------------
1099
1100 UNSAFE_ENTRY(jboolean, Unsafe_CompareAndSwapObject(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jobject e_h, jobject x_h))
1101 UnsafeWrapper("Unsafe_CompareAndSwapObject");
1102 // We are about to write to this entry so check to see if we need to copy it.
1103 oop p = oopDesc::bs()->resolve_and_maybe_copy_oop(JNIHandles::resolve(obj));
1104 HeapWord* addr = (HeapWord *)index_oop_from_field_offset_long(p, offset);
1105 oop x = JNIHandles::resolve(x_h);
1106 x = oopDesc::bs()->resolve_oop(x);
1107 oop old = JNIHandles::resolve(e_h);
1108 jboolean success;
1109 if (UseShenandoahGC) {
1110 oop expected;
1111 do {
1112 expected = old;
1113 old = oopDesc::atomic_compare_exchange_oop(x, addr, expected, true);
1114 success = (old == expected);
1115 } while ((! success) && oopDesc::bs()->resolve_oop(old) == oopDesc::bs()->resolve_oop(expected));
1116 } else {
1117 success = (old == oopDesc::atomic_compare_exchange_oop(x, addr, old, true));
1118 }
1119 if (success)
1120 update_barrier_set((void*)addr, x);
1121 return success;
1122 UNSAFE_END
1123
1124 UNSAFE_ENTRY(jboolean, Unsafe_CompareAndSwapInt(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jint e, jint x))
1125 UnsafeWrapper("Unsafe_CompareAndSwapInt");
1126 // We are about to write to this entry so check to see if we need to copy it.
1127 oop p = oopDesc::bs()->resolve_and_maybe_copy_oop(JNIHandles::resolve(obj));
1128 jint* addr = (jint *) index_oop_from_field_offset_long(p, offset);
1129 return (jint)(Atomic::cmpxchg(x, addr, e)) == e;
1130 UNSAFE_END
1131
1132 UNSAFE_ENTRY(jboolean, Unsafe_CompareAndSwapLong(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jlong e, jlong x))
1133 UnsafeWrapper("Unsafe_CompareAndSwapLong");
1134 Handle p (THREAD, oopDesc::bs()->resolve_and_maybe_copy_oop(JNIHandles::resolve(obj)));
1135 jlong* addr = (jlong*)(index_oop_from_field_offset_long(p(), offset));
1136 #ifdef SUPPORTS_NATIVE_CX8
1137 return (jlong)(Atomic::cmpxchg(x, addr, e)) == e;
1138 #else
1139 if (VM_Version::supports_cx8())
1140 return (jlong)(Atomic::cmpxchg(x, addr, e)) == e;
1141 else {
1142 jboolean success = false;
1143 MutexLockerEx mu(UnsafeJlong_lock, Mutex::_no_safepoint_check_flag);
1144 jlong val = Atomic::load(addr);
1145 if (val == e) { Atomic::store(x, addr); success = true; }
1146 return success;
1147 }
1148 #endif
1149 UNSAFE_END
1150
1151 UNSAFE_ENTRY(void, Unsafe_Park(JNIEnv *env, jobject unsafe, jboolean isAbsolute, jlong time))
1152 UnsafeWrapper("Unsafe_Park");
1153 EventThreadPark event;
1154 HOTSPOT_THREAD_PARK_BEGIN((uintptr_t) thread->parker(), (int) isAbsolute, time);
1155
1156 JavaThreadParkedState jtps(thread, time != 0);
1157 thread->parker()->park(isAbsolute != 0, time);
1158
1159 HOTSPOT_THREAD_PARK_END((uintptr_t) thread->parker());
1160 if (event.should_commit()) {
1161 oop obj = thread->current_park_blocker();
1162 event.set_klass((obj != NULL) ? obj->klass() : NULL);
1163 event.set_timeout(time);
1164 event.set_address((obj != NULL) ? (TYPE_ADDRESS) cast_from_oop<uintptr_t>(obj) : 0);
1165 event.commit();
1166 }
1167 UNSAFE_END
1168
1169 UNSAFE_ENTRY(void, Unsafe_Unpark(JNIEnv *env, jobject unsafe, jobject jthread))
1170 UnsafeWrapper("Unsafe_Unpark");
1171 Parker* p = NULL;
1172 if (jthread != NULL) {
1173 oop java_thread = JNIHandles::resolve_non_null(jthread);
1174 if (java_thread != NULL) {
1175 jlong lp = java_lang_Thread::park_event(java_thread);
1176 if (lp != 0) {
1177 // This cast is OK even though the jlong might have been read
1178 // non-atomically on 32bit systems, since there, one word will
1179 // always be zero anyway and the value set is always the same
1180 p = (Parker*)addr_from_java(lp);
1181 } else {
1182 // Grab lock if apparently null or using older version of library
1183 MutexLocker mu(Threads_lock);
1184 java_thread = JNIHandles::resolve_non_null(jthread);
1185 if (java_thread != NULL) {
1186 JavaThread* thr = java_lang_Thread::thread(java_thread);
1187 if (thr != NULL) {
1188 p = thr->parker();
1189 if (p != NULL) { // Bind to Java thread for next time.
1190 java_lang_Thread::set_park_event(java_thread, addr_to_java(p));
1191 }
1192 }
1193 }
1194 }
1195 }
1196 }
1197 if (p != NULL) {
1198 HOTSPOT_THREAD_UNPARK((uintptr_t) p);
1199 p->unpark();
1200 }
1201 UNSAFE_END
1202
1203 UNSAFE_ENTRY(jint, Unsafe_Loadavg(JNIEnv *env, jobject unsafe, jdoubleArray loadavg, jint nelem))
1204 UnsafeWrapper("Unsafe_Loadavg");
1205 const int max_nelem = 3;
1206 double la[max_nelem];
1207 jint ret;
1208
1209 typeArrayOop a = typeArrayOop(JNIHandles::resolve_non_null(loadavg));
1210 assert(a->is_typeArray(), "must be type array");
1211
1212 if (nelem < 0 || nelem > max_nelem || a->length() < nelem) {
1213 ThreadToNativeFromVM ttnfv(thread);
1214 throw_new(env, "ArrayIndexOutOfBoundsException");
1215 return -1;
1216 }
1217
1218 ret = os::loadavg(la, nelem);
1219 if (ret == -1) return -1;
1220
1221 // if successful, ret is the number of samples actually retrieved.
1222 assert(ret >= 0 && ret <= max_nelem, "Unexpected loadavg return value");
1223 switch(ret) {
1224 case 3: a->double_at_put(2, (jdouble)la[2]); // fall through
1225 case 2: a->double_at_put(1, (jdouble)la[1]); // fall through
1226 case 1: a->double_at_put(0, (jdouble)la[0]); break;
1227 }
1228 return ret;
1229 UNSAFE_END
1230
1231
1232 /// JVM_RegisterUnsafeMethods
1233
1234 #define ADR "J"
1235
1236 #define LANG "Ljava/lang/"
1237
1238 #define OBJ LANG "Object;"
1239 #define CLS LANG "Class;"
1240 #define FLD LANG "reflect/Field;"
1241 #define THR LANG "Throwable;"
1242
1243 #define DC_Args LANG "String;[BII" LANG "ClassLoader;" "Ljava/security/ProtectionDomain;"
1244 #define DAC_Args CLS "[B[" OBJ
1245
1246 #define CC (char*) /*cast a literal from (const char*)*/
1247 #define FN_PTR(f) CAST_FROM_FN_PTR(void*, &f)
1248
1249 #define DECLARE_GETPUTOOP(Boolean, Z) \
1250 {CC "get" #Boolean, CC "(" OBJ "J)" #Z, FN_PTR(Unsafe_Get##Boolean)}, \
1251 {CC "put" #Boolean, CC "(" OBJ "J" #Z ")V", FN_PTR(Unsafe_Set##Boolean)}, \
1252 {CC "get" #Boolean "Volatile", CC "(" OBJ "J)" #Z, FN_PTR(Unsafe_Get##Boolean##Volatile)}, \
1253 {CC "put" #Boolean "Volatile", CC "(" OBJ "J" #Z ")V", FN_PTR(Unsafe_Set##Boolean##Volatile)}
1254
1255
1256 #define DECLARE_GETPUTNATIVE(Byte, B) \
1257 {CC "get" #Byte, CC "(" ADR ")" #B, FN_PTR(Unsafe_GetNative##Byte)}, \
1258 {CC "put" #Byte, CC "(" ADR#B ")V", FN_PTR(Unsafe_SetNative##Byte)}
1259
1260
1261
1262 static JNINativeMethod methods[] = {
1263 {CC "getObject", CC "(" OBJ "J)" OBJ "", FN_PTR(Unsafe_GetObject)},
1264 {CC "putObject", CC "(" OBJ "J" OBJ ")V", FN_PTR(Unsafe_SetObject)},
1265 {CC "getObjectVolatile",CC "(" OBJ "J)" OBJ "", FN_PTR(Unsafe_GetObjectVolatile)},
1266 {CC "putObjectVolatile",CC "(" OBJ "J" OBJ ")V", FN_PTR(Unsafe_SetObjectVolatile)},
1267
1268 {CC "getUncompressedObject", CC "(" ADR ")" OBJ, FN_PTR(Unsafe_GetUncompressedObject)},
1269 {CC "getJavaMirror", CC "(" ADR ")" CLS, FN_PTR(Unsafe_GetJavaMirror)},
1270 {CC "getKlassPointer", CC "(" OBJ ")" ADR, FN_PTR(Unsafe_GetKlassPointer)},
1271
1272 DECLARE_GETPUTOOP(Boolean, Z),
1273 DECLARE_GETPUTOOP(Byte, B),
1274 DECLARE_GETPUTOOP(Short, S),
1275 DECLARE_GETPUTOOP(Char, C),
1276 DECLARE_GETPUTOOP(Int, I),
1277 DECLARE_GETPUTOOP(Long, J),
1278 DECLARE_GETPUTOOP(Float, F),
1279 DECLARE_GETPUTOOP(Double, D),
1280
1281 DECLARE_GETPUTNATIVE(Byte, B),
1282 DECLARE_GETPUTNATIVE(Short, S),
1283 DECLARE_GETPUTNATIVE(Char, C),
1284 DECLARE_GETPUTNATIVE(Int, I),
1285 DECLARE_GETPUTNATIVE(Long, J),
1286 DECLARE_GETPUTNATIVE(Float, F),
1287 DECLARE_GETPUTNATIVE(Double, D),
1288
1289 {CC "getAddress", CC "(" ADR ")" ADR, FN_PTR(Unsafe_GetNativeAddress)},
1290 {CC "putAddress", CC "(" ADR "" ADR ")V", FN_PTR(Unsafe_SetNativeAddress)},
1291
1292 {CC "allocateMemory", CC "(J)" ADR, FN_PTR(Unsafe_AllocateMemory)},
1293 {CC "reallocateMemory", CC "(" ADR "J)" ADR, FN_PTR(Unsafe_ReallocateMemory)},
1294 {CC "freeMemory", CC "(" ADR ")V", FN_PTR(Unsafe_FreeMemory)},
1295
1296 {CC "objectFieldOffset", CC "(" FLD ")J", FN_PTR(Unsafe_ObjectFieldOffset)},
1297 {CC "staticFieldOffset", CC "(" FLD ")J", FN_PTR(Unsafe_StaticFieldOffset)},
1298 {CC "staticFieldBase", CC "(" FLD ")" OBJ, FN_PTR(Unsafe_StaticFieldBaseFromField)},
1299 {CC "ensureClassInitialized",CC "(" CLS ")V", FN_PTR(Unsafe_EnsureClassInitialized)},
1300 {CC "arrayBaseOffset", CC "(" CLS ")I", FN_PTR(Unsafe_ArrayBaseOffset)},
1301 {CC "arrayIndexScale", CC "(" CLS ")I", FN_PTR(Unsafe_ArrayIndexScale)},
1302 {CC "addressSize", CC "()I", FN_PTR(Unsafe_AddressSize)},
1303 {CC "pageSize", CC "()I", FN_PTR(Unsafe_PageSize)},
1304
1305 {CC "defineClass", CC "(" DC_Args ")" CLS, FN_PTR(Unsafe_DefineClass)},
1306 {CC "allocateInstance", CC "(" CLS ")" OBJ, FN_PTR(Unsafe_AllocateInstance)},
1307 {CC "throwException", CC "(" THR ")V", FN_PTR(Unsafe_ThrowException)},
1308 {CC "compareAndSwapObject", CC "(" OBJ "J" OBJ "" OBJ ")Z", FN_PTR(Unsafe_CompareAndSwapObject)},
1309 {CC "compareAndSwapInt", CC "(" OBJ "J""I""I"")Z", FN_PTR(Unsafe_CompareAndSwapInt)},
1310 {CC "compareAndSwapLong", CC "(" OBJ "J""J""J"")Z", FN_PTR(Unsafe_CompareAndSwapLong)},
1311 {CC "putOrderedObject", CC "(" OBJ "J" OBJ ")V", FN_PTR(Unsafe_SetOrderedObject)},
1312 {CC "putOrderedInt", CC "(" OBJ "JI)V", FN_PTR(Unsafe_SetOrderedInt)},
1313 {CC "putOrderedLong", CC "(" OBJ "JJ)V", FN_PTR(Unsafe_SetOrderedLong)},
1314 {CC "park", CC "(ZJ)V", FN_PTR(Unsafe_Park)},
1315 {CC "unpark", CC "(" OBJ ")V", FN_PTR(Unsafe_Unpark)},
1316
1317 {CC "getLoadAverage", CC "([DI)I", FN_PTR(Unsafe_Loadavg)},
1318
1319 {CC "copyMemory", CC "(" OBJ "J" OBJ "JJ)V", FN_PTR(Unsafe_CopyMemory)},
1320 {CC "setMemory", CC "(" OBJ "JJB)V", FN_PTR(Unsafe_SetMemory)},
1321
1322 {CC "defineAnonymousClass", CC "(" DAC_Args ")" CLS, FN_PTR(Unsafe_DefineAnonymousClass)},
1323
1324 {CC "shouldBeInitialized",CC "(" CLS ")Z", FN_PTR(Unsafe_ShouldBeInitialized)},
1325
1326 {CC "loadFence", CC "()V", FN_PTR(Unsafe_LoadFence)},
1327 {CC "storeFence", CC "()V", FN_PTR(Unsafe_StoreFence)},
1328 {CC "fullFence", CC "()V", FN_PTR(Unsafe_FullFence)},
1329
1330 {CC "isBigEndian0", CC "()Z", FN_PTR(Unsafe_isBigEndian0)},
1331 {CC "unalignedAccess0", CC "()Z", FN_PTR(Unsafe_unalignedAccess0)}
1332 };
1333
1334 #undef CC
1335 #undef FN_PTR
1336
1337 #undef ADR
1338 #undef LANG
1339 #undef OBJ
1340 #undef CLS
1341 #undef FLD
1342 #undef THR
1343 #undef DC_Args
1344 #undef DAC_Args
1345
1346 #undef DECLARE_GETPUTOOP
1347 #undef DECLARE_GETPUTNATIVE
1348
1349
1350 // This one function is exported, used by NativeLookup.
1351 // The Unsafe_xxx functions above are called only from the interpreter.
1352 // The optimizer looks at names and signatures to recognize
1353 // individual functions.
1354
1355 JVM_ENTRY(void, JVM_RegisterUnsafeMethods(JNIEnv *env, jclass unsafeclass))
1356 UnsafeWrapper("JVM_RegisterUnsafeMethods");
1357 {
1358 ThreadToNativeFromVM ttnfv(thread);
1359
1360 int ok = env->RegisterNatives(unsafeclass, methods, sizeof(methods)/sizeof(JNINativeMethod));
1361 guarantee(ok == 0, "register unsafe natives");
1362 }
1363 JVM_END