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