1 /* 2 * Copyright (c) 2000, 2018, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 * 23 */ 24 25 #include "precompiled.hpp" 26 #include "jni.h" 27 #include "jvm.h" 28 #include "classfile/classFileStream.hpp" 29 #include "classfile/vmSymbols.hpp" 30 #include "jfr/jfrEvents.hpp" 31 #include "memory/allocation.inline.hpp" 32 #include "memory/resourceArea.hpp" 33 #include "logging/log.hpp" 34 #include "oops/access.inline.hpp" 35 #include "oops/fieldStreams.hpp" 36 #include "oops/objArrayOop.inline.hpp" 37 #include "oops/oop.inline.hpp" 38 #include "oops/typeArrayOop.inline.hpp" 39 #include "oops/valueArrayKlass.hpp" 40 #include "oops/valueArrayOop.hpp" 41 #include "oops/valueArrayOop.inline.hpp" 42 #include "prims/unsafe.hpp" 43 #include "runtime/atomic.hpp" 44 #include "runtime/fieldDescriptor.inline.hpp" 45 #include "runtime/globals.hpp" 46 #include "runtime/interfaceSupport.inline.hpp" 47 #include "runtime/jniHandles.inline.hpp" 48 #include "runtime/orderAccess.hpp" 49 #include "runtime/reflection.hpp" 50 #include "runtime/thread.hpp" 51 #include "runtime/threadSMR.hpp" 52 #include "runtime/vm_version.hpp" 53 #include "services/threadService.hpp" 54 #include "utilities/align.hpp" 55 #include "utilities/copy.hpp" 56 #include "utilities/dtrace.hpp" 57 #include "utilities/macros.hpp" 58 59 /** 60 * Implementation of the jdk.internal.misc.Unsafe class 61 */ 62 63 64 #define MAX_OBJECT_SIZE \ 65 ( arrayOopDesc::header_size(T_DOUBLE) * HeapWordSize \ 66 + ((julong)max_jint * sizeof(double)) ) 67 68 69 #define UNSAFE_ENTRY(result_type, header) \ 70 JVM_ENTRY(static result_type, header) 71 72 #define UNSAFE_LEAF(result_type, header) \ 73 JVM_LEAF(static result_type, header) 74 75 #define UNSAFE_END JVM_END 76 77 78 static 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 static 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 static inline jlong field_offset_to_byte_offset(jlong field_offset) { 103 return field_offset; 104 } 105 106 static inline jlong field_offset_from_byte_offset(jlong byte_offset) { 107 return byte_offset; 108 } 109 110 static inline void assert_field_offset_sane(oop p, jlong field_offset) { 111 #ifdef ASSERT 112 jlong byte_offset = field_offset_to_byte_offset(field_offset); 113 114 if (p != NULL) { 115 assert(byte_offset >= 0 && byte_offset <= (jlong)MAX_OBJECT_SIZE, "sane offset"); 116 if (byte_offset == (jint)byte_offset) { 117 void* ptr_plus_disp = (address)p + byte_offset; 118 assert(p->field_addr_raw((jint)byte_offset) == ptr_plus_disp, 119 "raw [ptr+disp] must be consistent with oop::field_addr_raw"); 120 } 121 jlong p_size = HeapWordSize * (jlong)(p->size()); 122 assert(byte_offset < p_size, "Unsafe access: offset " INT64_FORMAT " > object's size " INT64_FORMAT, (int64_t)byte_offset, (int64_t)p_size); 123 } 124 #endif 125 } 126 127 static inline void* index_oop_from_field_offset_long(oop p, jlong field_offset) { 128 assert_field_offset_sane(p, field_offset); 129 jlong byte_offset = field_offset_to_byte_offset(field_offset); 130 131 if (p != NULL) { 132 p = Access<>::resolve(p); 133 } 134 135 if (sizeof(char*) == sizeof(jint)) { // (this constant folds!) 136 return (address)p + (jint) byte_offset; 137 } else { 138 return (address)p + byte_offset; 139 } 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 } 150 151 152 ///// Data read/writes on the Java heap and in native (off-heap) memory 153 154 /** 155 * Helper class for accessing memory. 156 * 157 * Normalizes values and wraps accesses in 158 * JavaThread::doing_unsafe_access() if needed. 159 */ 160 template <typename T> 161 class MemoryAccess : StackObj { 162 JavaThread* _thread; 163 oop _obj; 164 ptrdiff_t _offset; 165 166 // Resolves and returns the address of the memory access. 167 // This raw memory access may fault, so we make sure it happens within the 168 // guarded scope by making the access volatile at least. Since the store 169 // of Thread::set_doing_unsafe_access() is also volatile, these accesses 170 // can not be reordered by the compiler. Therefore, if the access triggers 171 // a fault, we will know that Thread::doing_unsafe_access() returns true. 172 volatile T* addr() { 173 void* addr = index_oop_from_field_offset_long(_obj, _offset); 174 return static_cast<volatile T*>(addr); 175 } 176 177 template <typename U> 178 U normalize_for_write(U x) { 179 return x; 180 } 181 182 jboolean normalize_for_write(jboolean x) { 183 return x & 1; 184 } 185 186 template <typename U> 187 U normalize_for_read(U x) { 188 return x; 189 } 190 191 jboolean normalize_for_read(jboolean x) { 192 return x != 0; 193 } 194 195 /** 196 * Helper class to wrap memory accesses in JavaThread::doing_unsafe_access() 197 */ 198 class GuardUnsafeAccess { 199 JavaThread* _thread; 200 201 public: 202 GuardUnsafeAccess(JavaThread* thread) : _thread(thread) { 203 // native/off-heap access which may raise SIGBUS if accessing 204 // memory mapped file data in a region of the file which has 205 // been truncated and is now invalid 206 _thread->set_doing_unsafe_access(true); 207 } 208 209 ~GuardUnsafeAccess() { 210 _thread->set_doing_unsafe_access(false); 211 } 212 }; 213 214 public: 215 MemoryAccess(JavaThread* thread, jobject obj, jlong offset) 216 : _thread(thread), _obj(JNIHandles::resolve(obj)), _offset((ptrdiff_t)offset) { 217 assert_field_offset_sane(_obj, offset); 218 } 219 220 T get() { 221 if (_obj == NULL) { 222 GuardUnsafeAccess guard(_thread); 223 T ret = RawAccess<>::load(addr()); 224 return normalize_for_read(ret); 225 } else { 226 T ret = HeapAccess<>::load_at(_obj, _offset); 227 return normalize_for_read(ret); 228 } 229 } 230 231 void put(T x) { 232 if (_obj == NULL) { 233 GuardUnsafeAccess guard(_thread); 234 RawAccess<>::store(addr(), normalize_for_write(x)); 235 } else { 236 HeapAccess<>::store_at(_obj, _offset, normalize_for_write(x)); 237 } 238 } 239 240 241 T get_volatile() { 242 if (_obj == NULL) { 243 GuardUnsafeAccess guard(_thread); 244 volatile T ret = RawAccess<MO_SEQ_CST>::load(addr()); 245 return normalize_for_read(ret); 246 } else { 247 T ret = HeapAccess<MO_SEQ_CST>::load_at(_obj, _offset); 248 return normalize_for_read(ret); 249 } 250 } 251 252 void put_volatile(T x) { 253 if (_obj == NULL) { 254 GuardUnsafeAccess guard(_thread); 255 RawAccess<MO_SEQ_CST>::store(addr(), normalize_for_write(x)); 256 } else { 257 HeapAccess<MO_SEQ_CST>::store_at(_obj, _offset, normalize_for_write(x)); 258 } 259 } 260 }; 261 262 #ifdef ASSERT 263 /* 264 * Get the field descriptor of the field of the given object at the given offset. 265 */ 266 static bool get_field_descriptor(oop p, jlong offset, fieldDescriptor* fd) { 267 bool found = false; 268 Klass* k = p->klass(); 269 if (k->is_instance_klass()) { 270 InstanceKlass* ik = InstanceKlass::cast(k); 271 found = ik->find_field_from_offset((int)offset, false, fd); 272 if (!found && ik->is_mirror_instance_klass()) { 273 Klass* k2 = java_lang_Class::as_Klass(p); 274 if (k2->is_instance_klass()) { 275 ik = InstanceKlass::cast(k2); 276 found = ik->find_field_from_offset((int)offset, true, fd); 277 } 278 } 279 } 280 return found; 281 } 282 #endif // ASSERT 283 284 static void assert_and_log_unsafe_value_type_access(oop p, jlong offset, ValueKlass* vk) { 285 Klass* k = p->klass(); 286 287 #ifdef ASSERT 288 if (k->is_instance_klass()) { 289 assert_field_offset_sane(p, offset); 290 fieldDescriptor fd; 291 bool found = get_field_descriptor(p, offset, &fd); 292 assert(found, "value field not found"); 293 assert(fd.is_flattened(), "field not flat"); 294 } else if (k->is_valueArray_klass()) { 295 ValueArrayKlass* vak = ValueArrayKlass::cast(k); 296 int index = (offset - vak->array_header_in_bytes()) / vak->element_byte_size(); 297 address dest = (address)((valueArrayOop)p)->value_at_addr(index, vak->layout_helper()); 298 assert(dest == ((address)p) + offset, "invalid offset"); 299 } else { 300 ShouldNotReachHere(); 301 } 302 #endif // ASSERT 303 304 if (log_is_enabled(Trace, valuetypes)) { 305 if (k->is_valueArray_klass()) { 306 ValueArrayKlass* vak = ValueArrayKlass::cast(k); 307 int index = (offset - vak->array_header_in_bytes()) / vak->element_byte_size(); 308 address dest = (address)((valueArrayOop)p)->value_at_addr(index, vak->layout_helper()); 309 log_trace(valuetypes)("array type %s index %d element size %d offset " SIZE_FORMAT_HEX " at " INTPTR_FORMAT, 310 vak->external_name(), index, vak->element_byte_size(), offset, p2i(dest)); 311 } else { 312 log_trace(valuetypes)("field type %s at offset " SIZE_FORMAT_HEX, 313 vk->external_name(), offset); 314 } 315 } 316 } 317 318 // These functions allow a null base pointer with an arbitrary address. 319 // But if the base pointer is non-null, the offset should make some sense. 320 // That is, it should be in the range [0, MAX_OBJECT_SIZE]. 321 UNSAFE_ENTRY(jobject, Unsafe_GetReference(JNIEnv *env, jobject unsafe, jobject obj, jlong offset)) { 322 oop p = JNIHandles::resolve(obj); 323 assert_field_offset_sane(p, offset); 324 oop v = HeapAccess<ON_UNKNOWN_OOP_REF>::oop_load_at(p, offset); 325 return JNIHandles::make_local(env, v); 326 } UNSAFE_END 327 328 UNSAFE_ENTRY(void, Unsafe_PutReference(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jobject x_h)) { 329 oop x = JNIHandles::resolve(x_h); 330 oop p = JNIHandles::resolve(obj); 331 assert_field_offset_sane(p, offset); 332 HeapAccess<ON_UNKNOWN_OOP_REF>::oop_store_at(p, offset, x); 333 } UNSAFE_END 334 335 UNSAFE_ENTRY(jboolean, Unsafe_IsFlattenedArray(JNIEnv *env, jobject unsafe, jclass c)) { 336 Klass* k = java_lang_Class::as_Klass(JNIHandles::resolve_non_null(c)); 337 return k->is_valueArray_klass(); 338 } UNSAFE_END 339 340 UNSAFE_ENTRY(jobject, Unsafe_GetValue(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jclass c)) { 341 oop p = JNIHandles::resolve(obj); 342 Klass* k = java_lang_Class::as_Klass(JNIHandles::resolve_non_null(c)); 343 ValueKlass* vk = ValueKlass::cast(k); 344 assert_and_log_unsafe_value_type_access(p, offset, vk); 345 Handle p_h(THREAD, p); 346 oop v = vk->allocate_instance(CHECK_NULL); // allocate instance 347 vk->initialize(CHECK_NULL); // If field is a default value, value class might not be initialized yet 348 vk->value_store(((char*)(oopDesc*)p_h()) + offset, 349 vk->data_for_oop(v), 350 true, true); 351 return JNIHandles::make_local(env, v); 352 } UNSAFE_END 353 354 UNSAFE_ENTRY(void, Unsafe_PutValue(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jclass c, jobject value)) { 355 oop v = JNIHandles::resolve(value); 356 oop p = JNIHandles::resolve(obj); 357 Klass* k = java_lang_Class::as_Klass(JNIHandles::resolve_non_null(c)); 358 ValueKlass* vk = ValueKlass::cast(k); 359 assert_and_log_unsafe_value_type_access(p, offset, vk); 360 vk->value_store(vk->data_for_oop(v), 361 ((char*)(oopDesc*)p) + offset, true, true); 362 } UNSAFE_END 363 364 UNSAFE_ENTRY(jobject, Unsafe_GetReferenceVolatile(JNIEnv *env, jobject unsafe, jobject obj, jlong offset)) { 365 oop p = JNIHandles::resolve(obj); 366 assert_field_offset_sane(p, offset); 367 oop v = HeapAccess<MO_SEQ_CST | ON_UNKNOWN_OOP_REF>::oop_load_at(p, offset); 368 return JNIHandles::make_local(env, v); 369 } UNSAFE_END 370 371 UNSAFE_ENTRY(void, Unsafe_PutReferenceVolatile(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jobject x_h)) { 372 oop x = JNIHandles::resolve(x_h); 373 oop p = JNIHandles::resolve(obj); 374 assert_field_offset_sane(p, offset); 375 HeapAccess<MO_SEQ_CST | ON_UNKNOWN_OOP_REF>::oop_store_at(p, offset, x); 376 } UNSAFE_END 377 378 UNSAFE_ENTRY(jobject, Unsafe_GetUncompressedObject(JNIEnv *env, jobject unsafe, jlong addr)) { 379 oop v = *(oop*) (address) addr; 380 return JNIHandles::make_local(env, v); 381 } UNSAFE_END 382 383 UNSAFE_LEAF(jboolean, Unsafe_isBigEndian0(JNIEnv *env, jobject unsafe)) { 384 #ifdef VM_LITTLE_ENDIAN 385 return false; 386 #else 387 return true; 388 #endif 389 } UNSAFE_END 390 391 UNSAFE_LEAF(jint, Unsafe_unalignedAccess0(JNIEnv *env, jobject unsafe)) { 392 return UseUnalignedAccesses; 393 } UNSAFE_END 394 395 #define DEFINE_GETSETOOP(java_type, Type) \ 396 \ 397 UNSAFE_ENTRY(java_type, Unsafe_Get##Type(JNIEnv *env, jobject unsafe, jobject obj, jlong offset)) { \ 398 return MemoryAccess<java_type>(thread, obj, offset).get(); \ 399 } UNSAFE_END \ 400 \ 401 UNSAFE_ENTRY(void, Unsafe_Put##Type(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, java_type x)) { \ 402 MemoryAccess<java_type>(thread, obj, offset).put(x); \ 403 } UNSAFE_END \ 404 \ 405 // END DEFINE_GETSETOOP. 406 407 DEFINE_GETSETOOP(jboolean, Boolean) 408 DEFINE_GETSETOOP(jbyte, Byte) 409 DEFINE_GETSETOOP(jshort, Short); 410 DEFINE_GETSETOOP(jchar, Char); 411 DEFINE_GETSETOOP(jint, Int); 412 DEFINE_GETSETOOP(jlong, Long); 413 DEFINE_GETSETOOP(jfloat, Float); 414 DEFINE_GETSETOOP(jdouble, Double); 415 416 #undef DEFINE_GETSETOOP 417 418 #define DEFINE_GETSETOOP_VOLATILE(java_type, Type) \ 419 \ 420 UNSAFE_ENTRY(java_type, Unsafe_Get##Type##Volatile(JNIEnv *env, jobject unsafe, jobject obj, jlong offset)) { \ 421 return MemoryAccess<java_type>(thread, obj, offset).get_volatile(); \ 422 } UNSAFE_END \ 423 \ 424 UNSAFE_ENTRY(void, Unsafe_Put##Type##Volatile(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, java_type x)) { \ 425 MemoryAccess<java_type>(thread, obj, offset).put_volatile(x); \ 426 } UNSAFE_END \ 427 \ 428 // END DEFINE_GETSETOOP_VOLATILE. 429 430 DEFINE_GETSETOOP_VOLATILE(jboolean, Boolean) 431 DEFINE_GETSETOOP_VOLATILE(jbyte, Byte) 432 DEFINE_GETSETOOP_VOLATILE(jshort, Short); 433 DEFINE_GETSETOOP_VOLATILE(jchar, Char); 434 DEFINE_GETSETOOP_VOLATILE(jint, Int); 435 DEFINE_GETSETOOP_VOLATILE(jlong, Long); 436 DEFINE_GETSETOOP_VOLATILE(jfloat, Float); 437 DEFINE_GETSETOOP_VOLATILE(jdouble, Double); 438 439 #undef DEFINE_GETSETOOP_VOLATILE 440 441 UNSAFE_LEAF(void, Unsafe_LoadFence(JNIEnv *env, jobject unsafe)) { 442 OrderAccess::acquire(); 443 } UNSAFE_END 444 445 UNSAFE_LEAF(void, Unsafe_StoreFence(JNIEnv *env, jobject unsafe)) { 446 OrderAccess::release(); 447 } UNSAFE_END 448 449 UNSAFE_LEAF(void, Unsafe_FullFence(JNIEnv *env, jobject unsafe)) { 450 OrderAccess::fence(); 451 } UNSAFE_END 452 453 ////// Allocation requests 454 455 UNSAFE_ENTRY(jobject, Unsafe_AllocateInstance(JNIEnv *env, jobject unsafe, jclass cls)) { 456 ThreadToNativeFromVM ttnfv(thread); 457 return env->AllocObject(cls); 458 } UNSAFE_END 459 460 UNSAFE_ENTRY(jlong, Unsafe_AllocateMemory0(JNIEnv *env, jobject unsafe, jlong size)) { 461 size_t sz = (size_t)size; 462 463 sz = align_up(sz, HeapWordSize); 464 void* x = os::malloc(sz, mtOther); 465 466 return addr_to_java(x); 467 } UNSAFE_END 468 469 UNSAFE_ENTRY(jlong, Unsafe_ReallocateMemory0(JNIEnv *env, jobject unsafe, jlong addr, jlong size)) { 470 void* p = addr_from_java(addr); 471 size_t sz = (size_t)size; 472 sz = align_up(sz, HeapWordSize); 473 474 void* x = os::realloc(p, sz, mtOther); 475 476 return addr_to_java(x); 477 } UNSAFE_END 478 479 UNSAFE_ENTRY(void, Unsafe_FreeMemory0(JNIEnv *env, jobject unsafe, jlong addr)) { 480 void* p = addr_from_java(addr); 481 482 os::free(p); 483 } UNSAFE_END 484 485 UNSAFE_ENTRY(void, Unsafe_SetMemory0(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jlong size, jbyte value)) { 486 size_t sz = (size_t)size; 487 488 oop base = JNIHandles::resolve(obj); 489 void* p = index_oop_from_field_offset_long(base, offset); 490 491 Copy::fill_to_memory_atomic(p, sz, value); 492 } UNSAFE_END 493 494 UNSAFE_ENTRY(void, Unsafe_CopyMemory0(JNIEnv *env, jobject unsafe, jobject srcObj, jlong srcOffset, jobject dstObj, jlong dstOffset, jlong size)) { 495 size_t sz = (size_t)size; 496 497 oop srcp = JNIHandles::resolve(srcObj); 498 oop dstp = JNIHandles::resolve(dstObj); 499 500 void* src = index_oop_from_field_offset_long(srcp, srcOffset); 501 void* dst = index_oop_from_field_offset_long(dstp, dstOffset); 502 503 Copy::conjoint_memory_atomic(src, dst, sz); 504 } UNSAFE_END 505 506 // This function is a leaf since if the source and destination are both in native memory 507 // the copy may potentially be very large, and we don't want to disable GC if we can avoid it. 508 // If either source or destination (or both) are on the heap, the function will enter VM using 509 // JVM_ENTRY_FROM_LEAF 510 UNSAFE_LEAF(void, Unsafe_CopySwapMemory0(JNIEnv *env, jobject unsafe, jobject srcObj, jlong srcOffset, jobject dstObj, jlong dstOffset, jlong size, jlong elemSize)) { 511 size_t sz = (size_t)size; 512 size_t esz = (size_t)elemSize; 513 514 if (srcObj == NULL && dstObj == NULL) { 515 // Both src & dst are in native memory 516 address src = (address)srcOffset; 517 address dst = (address)dstOffset; 518 519 Copy::conjoint_swap(src, dst, sz, esz); 520 } else { 521 // At least one of src/dst are on heap, transition to VM to access raw pointers 522 523 JVM_ENTRY_FROM_LEAF(env, void, Unsafe_CopySwapMemory0) { 524 oop srcp = JNIHandles::resolve(srcObj); 525 oop dstp = JNIHandles::resolve(dstObj); 526 527 address src = (address)index_oop_from_field_offset_long(srcp, srcOffset); 528 address dst = (address)index_oop_from_field_offset_long(dstp, dstOffset); 529 530 Copy::conjoint_swap(src, dst, sz, esz); 531 } JVM_END 532 } 533 } UNSAFE_END 534 535 ////// Random queries 536 537 UNSAFE_LEAF(jint, Unsafe_AddressSize0(JNIEnv *env, jobject unsafe)) { 538 return sizeof(void*); 539 } UNSAFE_END 540 541 UNSAFE_LEAF(jint, Unsafe_PageSize()) { 542 return os::vm_page_size(); 543 } UNSAFE_END 544 545 static jlong find_field_offset(jclass clazz, jstring name, TRAPS) { 546 assert(clazz != NULL, "clazz must not be NULL"); 547 assert(name != NULL, "name must not be NULL"); 548 549 ResourceMark rm(THREAD); 550 char *utf_name = java_lang_String::as_utf8_string(JNIHandles::resolve_non_null(name)); 551 552 InstanceKlass* k = InstanceKlass::cast(java_lang_Class::as_Klass(JNIHandles::resolve_non_null(clazz))); 553 554 jint offset = -1; 555 for (JavaFieldStream fs(k); !fs.done(); fs.next()) { 556 Symbol *name = fs.name(); 557 if (name->equals(utf_name)) { 558 offset = fs.offset(); 559 break; 560 } 561 } 562 if (offset < 0) { 563 THROW_0(vmSymbols::java_lang_InternalError()); 564 } 565 return field_offset_from_byte_offset(offset); 566 } 567 568 static jlong find_field_offset(jobject field, int must_be_static, TRAPS) { 569 assert(field != NULL, "field must not be NULL"); 570 571 oop reflected = JNIHandles::resolve_non_null(field); 572 oop mirror = java_lang_reflect_Field::clazz(reflected); 573 Klass* k = java_lang_Class::as_Klass(mirror); 574 int slot = java_lang_reflect_Field::slot(reflected); 575 int modifiers = java_lang_reflect_Field::modifiers(reflected); 576 577 if (must_be_static >= 0) { 578 int really_is_static = ((modifiers & JVM_ACC_STATIC) != 0); 579 if (must_be_static != really_is_static) { 580 THROW_0(vmSymbols::java_lang_IllegalArgumentException()); 581 } 582 } 583 584 int offset = InstanceKlass::cast(k)->field_offset(slot); 585 return field_offset_from_byte_offset(offset); 586 } 587 588 UNSAFE_ENTRY(jlong, Unsafe_ObjectFieldOffset0(JNIEnv *env, jobject unsafe, jobject field)) { 589 return find_field_offset(field, 0, THREAD); 590 } UNSAFE_END 591 592 UNSAFE_ENTRY(jlong, Unsafe_ObjectFieldOffset1(JNIEnv *env, jobject unsafe, jclass c, jstring name)) { 593 return find_field_offset(c, name, THREAD); 594 } UNSAFE_END 595 596 UNSAFE_ENTRY(jlong, Unsafe_StaticFieldOffset0(JNIEnv *env, jobject unsafe, jobject field)) { 597 return find_field_offset(field, 1, THREAD); 598 } UNSAFE_END 599 600 UNSAFE_ENTRY(jobject, Unsafe_StaticFieldBase0(JNIEnv *env, jobject unsafe, jobject field)) { 601 assert(field != NULL, "field must not be NULL"); 602 603 // Note: In this VM implementation, a field address is always a short 604 // offset from the base of a a klass metaobject. Thus, the full dynamic 605 // range of the return type is never used. However, some implementations 606 // might put the static field inside an array shared by many classes, 607 // or even at a fixed address, in which case the address could be quite 608 // large. In that last case, this function would return NULL, since 609 // the address would operate alone, without any base pointer. 610 611 oop reflected = JNIHandles::resolve_non_null(field); 612 oop mirror = java_lang_reflect_Field::clazz(reflected); 613 int modifiers = java_lang_reflect_Field::modifiers(reflected); 614 615 if ((modifiers & JVM_ACC_STATIC) == 0) { 616 THROW_0(vmSymbols::java_lang_IllegalArgumentException()); 617 } 618 619 return JNIHandles::make_local(env, mirror); 620 } UNSAFE_END 621 622 UNSAFE_ENTRY(void, Unsafe_EnsureClassInitialized0(JNIEnv *env, jobject unsafe, jobject clazz)) { 623 assert(clazz != NULL, "clazz must not be NULL"); 624 625 oop mirror = JNIHandles::resolve_non_null(clazz); 626 627 Klass* klass = java_lang_Class::as_Klass(mirror); 628 if (klass != NULL && klass->should_be_initialized()) { 629 InstanceKlass* k = InstanceKlass::cast(klass); 630 k->initialize(CHECK); 631 } 632 } 633 UNSAFE_END 634 635 UNSAFE_ENTRY(jboolean, Unsafe_ShouldBeInitialized0(JNIEnv *env, jobject unsafe, jobject clazz)) { 636 assert(clazz != NULL, "clazz must not be NULL"); 637 638 oop mirror = JNIHandles::resolve_non_null(clazz); 639 Klass* klass = java_lang_Class::as_Klass(mirror); 640 641 if (klass != NULL && klass->should_be_initialized()) { 642 return true; 643 } 644 645 return false; 646 } 647 UNSAFE_END 648 649 static void getBaseAndScale(int& base, int& scale, jclass clazz, TRAPS) { 650 assert(clazz != NULL, "clazz must not be NULL"); 651 652 oop mirror = JNIHandles::resolve_non_null(clazz); 653 Klass* k = java_lang_Class::as_Klass(mirror); 654 655 if (k == NULL || !k->is_array_klass()) { 656 THROW(vmSymbols::java_lang_InvalidClassException()); 657 } else if (k->is_objArray_klass()) { 658 base = arrayOopDesc::base_offset_in_bytes(T_OBJECT); 659 scale = heapOopSize; 660 } else if (k->is_typeArray_klass()) { 661 TypeArrayKlass* tak = TypeArrayKlass::cast(k); 662 base = tak->array_header_in_bytes(); 663 assert(base == arrayOopDesc::base_offset_in_bytes(tak->element_type()), "array_header_size semantics ok"); 664 scale = (1 << tak->log2_element_size()); 665 } else if (k->is_valueArray_klass()) { 666 ValueArrayKlass* vak = ValueArrayKlass::cast(k); 667 ValueKlass* vklass = vak->element_klass(); 668 base = vak->array_header_in_bytes(); 669 scale = vak->element_byte_size(); 670 } else { 671 ShouldNotReachHere(); 672 } 673 } 674 675 UNSAFE_ENTRY(jint, Unsafe_ArrayBaseOffset0(JNIEnv *env, jobject unsafe, jclass clazz)) { 676 int base = 0, scale = 0; 677 getBaseAndScale(base, scale, clazz, CHECK_0); 678 679 return field_offset_from_byte_offset(base); 680 } UNSAFE_END 681 682 683 UNSAFE_ENTRY(jint, Unsafe_ArrayIndexScale0(JNIEnv *env, jobject unsafe, jclass clazz)) { 684 int base = 0, scale = 0; 685 getBaseAndScale(base, scale, clazz, CHECK_0); 686 687 // This VM packs both fields and array elements down to the byte. 688 // But watch out: If this changes, so that array references for 689 // a given primitive type (say, T_BOOLEAN) use different memory units 690 // than fields, this method MUST return zero for such arrays. 691 // For example, the VM used to store sub-word sized fields in full 692 // words in the object layout, so that accessors like getByte(Object,int) 693 // did not really do what one might expect for arrays. Therefore, 694 // this function used to report a zero scale factor, so that the user 695 // would know not to attempt to access sub-word array elements. 696 // // Code for unpacked fields: 697 // if (scale < wordSize) return 0; 698 699 // The following allows for a pretty general fieldOffset cookie scheme, 700 // but requires it to be linear in byte offset. 701 return field_offset_from_byte_offset(scale) - field_offset_from_byte_offset(0); 702 } UNSAFE_END 703 704 705 static inline void throw_new(JNIEnv *env, const char *ename) { 706 jclass cls = env->FindClass(ename); 707 if (env->ExceptionCheck()) { 708 env->ExceptionClear(); 709 tty->print_cr("Unsafe: cannot throw %s because FindClass has failed", ename); 710 return; 711 } 712 713 env->ThrowNew(cls, NULL); 714 } 715 716 static jclass Unsafe_DefineClass_impl(JNIEnv *env, jstring name, jbyteArray data, int offset, int length, jobject loader, jobject pd) { 717 // Code lifted from JDK 1.3 ClassLoader.c 718 719 jbyte *body; 720 char *utfName = NULL; 721 jclass result = 0; 722 char buf[128]; 723 724 assert(data != NULL, "Class bytes must not be NULL"); 725 assert(length >= 0, "length must not be negative: %d", length); 726 727 if (UsePerfData) { 728 ClassLoader::unsafe_defineClassCallCounter()->inc(); 729 } 730 731 body = NEW_C_HEAP_ARRAY(jbyte, length, mtInternal); 732 if (body == NULL) { 733 throw_new(env, "java/lang/OutOfMemoryError"); 734 return 0; 735 } 736 737 env->GetByteArrayRegion(data, offset, length, body); 738 if (env->ExceptionOccurred()) { 739 goto free_body; 740 } 741 742 if (name != NULL) { 743 uint len = env->GetStringUTFLength(name); 744 int unicode_len = env->GetStringLength(name); 745 746 if (len >= sizeof(buf)) { 747 utfName = NEW_C_HEAP_ARRAY(char, len + 1, mtInternal); 748 if (utfName == NULL) { 749 throw_new(env, "java/lang/OutOfMemoryError"); 750 goto free_body; 751 } 752 } else { 753 utfName = buf; 754 } 755 756 env->GetStringUTFRegion(name, 0, unicode_len, utfName); 757 758 for (uint i = 0; i < len; i++) { 759 if (utfName[i] == '.') utfName[i] = '/'; 760 } 761 } 762 763 result = JVM_DefineClass(env, utfName, loader, body, length, pd); 764 765 if (utfName && utfName != buf) { 766 FREE_C_HEAP_ARRAY(char, utfName); 767 } 768 769 free_body: 770 FREE_C_HEAP_ARRAY(jbyte, body); 771 return result; 772 } 773 774 775 UNSAFE_ENTRY(jclass, Unsafe_DefineClass0(JNIEnv *env, jobject unsafe, jstring name, jbyteArray data, int offset, int length, jobject loader, jobject pd)) { 776 ThreadToNativeFromVM ttnfv(thread); 777 778 return Unsafe_DefineClass_impl(env, name, data, offset, length, loader, pd); 779 } UNSAFE_END 780 781 782 // define a class but do not make it known to the class loader or system dictionary 783 // - host_class: supplies context for linkage, access control, protection domain, and class loader 784 // if host_class is itself anonymous then it is replaced with its host class. 785 // - data: bytes of a class file, a raw memory address (length gives the number of bytes) 786 // - cp_patches: where non-null entries exist, they replace corresponding CP entries in data 787 788 // When you load an anonymous class U, it works as if you changed its name just before loading, 789 // to a name that you will never use again. Since the name is lost, no other class can directly 790 // link to any member of U. Just after U is loaded, the only way to use it is reflectively, 791 // through java.lang.Class methods like Class.newInstance. 792 793 // The package of an anonymous class must either match its host's class's package or be in the 794 // unnamed package. If it is in the unnamed package then it will be put in its host class's 795 // package. 796 // 797 798 // Access checks for linkage sites within U continue to follow the same rules as for named classes. 799 // An anonymous class also has special privileges to access any member of its host class. 800 // This is the main reason why this loading operation is unsafe. The purpose of this is to 801 // allow language implementations to simulate "open classes"; a host class in effect gets 802 // new code when an anonymous class is loaded alongside it. A less convenient but more 803 // standard way to do this is with reflection, which can also be set to ignore access 804 // restrictions. 805 806 // Access into an anonymous class is possible only through reflection. Therefore, there 807 // are no special access rules for calling into an anonymous class. The relaxed access 808 // rule for the host class is applied in the opposite direction: A host class reflectively 809 // access one of its anonymous classes. 810 811 // If you load the same bytecodes twice, you get two different classes. You can reload 812 // the same bytecodes with or without varying CP patches. 813 814 // By using the CP patching array, you can have a new anonymous class U2 refer to an older one U1. 815 // The bytecodes for U2 should refer to U1 by a symbolic name (doesn't matter what the name is). 816 // The CONSTANT_Class entry for that name can be patched to refer directly to U1. 817 818 // This allows, for example, U2 to use U1 as a superclass or super-interface, or as 819 // an outer class (so that U2 is an anonymous inner class of anonymous U1). 820 // It is not possible for a named class, or an older anonymous class, to refer by 821 // name (via its CP) to a newer anonymous class. 822 823 // CP patching may also be used to modify (i.e., hack) the names of methods, classes, 824 // or type descriptors used in the loaded anonymous class. 825 826 // Finally, CP patching may be used to introduce "live" objects into the constant pool, 827 // instead of "dead" strings. A compiled statement like println((Object)"hello") can 828 // be changed to println(greeting), where greeting is an arbitrary object created before 829 // the anonymous class is loaded. This is useful in dynamic languages, in which 830 // various kinds of metaobjects must be introduced as constants into bytecode. 831 // Note the cast (Object), which tells the verifier to expect an arbitrary object, 832 // not just a literal string. For such ldc instructions, the verifier uses the 833 // type Object instead of String, if the loaded constant is not in fact a String. 834 835 static InstanceKlass* 836 Unsafe_DefineAnonymousClass_impl(JNIEnv *env, 837 jclass host_class, jbyteArray data, jobjectArray cp_patches_jh, 838 u1** temp_alloc, 839 TRAPS) { 840 assert(host_class != NULL, "host_class must not be NULL"); 841 assert(data != NULL, "data must not be NULL"); 842 843 if (UsePerfData) { 844 ClassLoader::unsafe_defineClassCallCounter()->inc(); 845 } 846 847 jint length = typeArrayOop(JNIHandles::resolve_non_null(data))->length(); 848 assert(length >= 0, "class_bytes_length must not be negative: %d", length); 849 850 int class_bytes_length = (int) length; 851 852 u1* class_bytes = NEW_C_HEAP_ARRAY(u1, length, mtInternal); 853 if (class_bytes == NULL) { 854 THROW_0(vmSymbols::java_lang_OutOfMemoryError()); 855 } 856 857 // caller responsible to free it: 858 *temp_alloc = class_bytes; 859 860 ArrayAccess<>::arraycopy_to_native(arrayOop(JNIHandles::resolve_non_null(data)), typeArrayOopDesc::element_offset<jbyte>(0), 861 reinterpret_cast<jbyte*>(class_bytes), length); 862 863 objArrayHandle cp_patches_h; 864 if (cp_patches_jh != NULL) { 865 oop p = JNIHandles::resolve_non_null(cp_patches_jh); 866 assert(p->is_objArray(), "cp_patches must be an object[]"); 867 cp_patches_h = objArrayHandle(THREAD, (objArrayOop)p); 868 } 869 870 const Klass* host_klass = java_lang_Class::as_Klass(JNIHandles::resolve_non_null(host_class)); 871 872 // Make sure it's the real host class, not another anonymous class. 873 while (host_klass != NULL && host_klass->is_instance_klass() && 874 InstanceKlass::cast(host_klass)->is_unsafe_anonymous()) { 875 host_klass = InstanceKlass::cast(host_klass)->unsafe_anonymous_host(); 876 } 877 878 // Primitive types have NULL Klass* fields in their java.lang.Class instances. 879 if (host_klass == NULL) { 880 THROW_MSG_0(vmSymbols::java_lang_IllegalArgumentException(), "Host class is null"); 881 } 882 883 assert(host_klass->is_instance_klass(), "Host class must be an instance class"); 884 885 const char* host_source = host_klass->external_name(); 886 Handle host_loader(THREAD, host_klass->class_loader()); 887 Handle host_domain(THREAD, host_klass->protection_domain()); 888 889 GrowableArray<Handle>* cp_patches = NULL; 890 891 if (cp_patches_h.not_null()) { 892 int alen = cp_patches_h->length(); 893 894 for (int i = alen-1; i >= 0; i--) { 895 oop p = cp_patches_h->obj_at(i); 896 if (p != NULL) { 897 Handle patch(THREAD, p); 898 899 if (cp_patches == NULL) { 900 cp_patches = new GrowableArray<Handle>(i+1, i+1, Handle()); 901 } 902 903 cp_patches->at_put(i, patch); 904 } 905 } 906 } 907 908 ClassFileStream st(class_bytes, class_bytes_length, host_source, ClassFileStream::verify); 909 910 Symbol* no_class_name = NULL; 911 Klass* anonk = SystemDictionary::parse_stream(no_class_name, 912 host_loader, 913 host_domain, 914 &st, 915 InstanceKlass::cast(host_klass), 916 cp_patches, 917 CHECK_NULL); 918 if (anonk == NULL) { 919 return NULL; 920 } 921 922 return InstanceKlass::cast(anonk); 923 } 924 925 UNSAFE_ENTRY(jclass, Unsafe_DefineAnonymousClass0(JNIEnv *env, jobject unsafe, jclass host_class, jbyteArray data, jobjectArray cp_patches_jh)) { 926 ResourceMark rm(THREAD); 927 928 jobject res_jh = NULL; 929 u1* temp_alloc = NULL; 930 931 InstanceKlass* anon_klass = Unsafe_DefineAnonymousClass_impl(env, host_class, data, cp_patches_jh, &temp_alloc, THREAD); 932 if (anon_klass != NULL) { 933 res_jh = JNIHandles::make_local(env, anon_klass->java_mirror()); 934 } 935 936 // try/finally clause: 937 if (temp_alloc != NULL) { 938 FREE_C_HEAP_ARRAY(u1, temp_alloc); 939 } 940 941 // The anonymous class loader data has been artificially been kept alive to 942 // this point. The mirror and any instances of this class have to keep 943 // it alive afterwards. 944 if (anon_klass != NULL) { 945 anon_klass->class_loader_data()->dec_keep_alive(); 946 } 947 948 // let caller initialize it as needed... 949 950 return (jclass) res_jh; 951 } UNSAFE_END 952 953 954 955 UNSAFE_ENTRY(void, Unsafe_ThrowException(JNIEnv *env, jobject unsafe, jthrowable thr)) { 956 ThreadToNativeFromVM ttnfv(thread); 957 env->Throw(thr); 958 } UNSAFE_END 959 960 // JSR166 ------------------------------------------------------------------ 961 962 UNSAFE_ENTRY(jobject, Unsafe_CompareAndExchangeReference(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jobject e_h, jobject x_h)) { 963 oop x = JNIHandles::resolve(x_h); 964 oop e = JNIHandles::resolve(e_h); 965 oop p = JNIHandles::resolve(obj); 966 assert_field_offset_sane(p, offset); 967 oop res = HeapAccess<ON_UNKNOWN_OOP_REF>::oop_atomic_cmpxchg_at(x, p, (ptrdiff_t)offset, e); 968 return JNIHandles::make_local(env, res); 969 } UNSAFE_END 970 971 UNSAFE_ENTRY(jint, Unsafe_CompareAndExchangeInt(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jint e, jint x)) { 972 oop p = JNIHandles::resolve(obj); 973 if (p == NULL) { 974 volatile jint* addr = (volatile jint*)index_oop_from_field_offset_long(p, offset); 975 return RawAccess<>::atomic_cmpxchg(x, addr, e); 976 } else { 977 assert_field_offset_sane(p, offset); 978 return HeapAccess<>::atomic_cmpxchg_at(x, p, (ptrdiff_t)offset, e); 979 } 980 } UNSAFE_END 981 982 UNSAFE_ENTRY(jlong, Unsafe_CompareAndExchangeLong(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jlong e, jlong x)) { 983 oop p = JNIHandles::resolve(obj); 984 if (p == NULL) { 985 volatile jlong* addr = (volatile jlong*)index_oop_from_field_offset_long(p, offset); 986 return RawAccess<>::atomic_cmpxchg(x, addr, e); 987 } else { 988 assert_field_offset_sane(p, offset); 989 return HeapAccess<>::atomic_cmpxchg_at(x, p, (ptrdiff_t)offset, e); 990 } 991 } UNSAFE_END 992 993 UNSAFE_ENTRY(jboolean, Unsafe_CompareAndSetReference(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jobject e_h, jobject x_h)) { 994 oop x = JNIHandles::resolve(x_h); 995 oop e = JNIHandles::resolve(e_h); 996 oop p = JNIHandles::resolve(obj); 997 assert_field_offset_sane(p, offset); 998 oop ret = HeapAccess<ON_UNKNOWN_OOP_REF>::oop_atomic_cmpxchg_at(x, p, (ptrdiff_t)offset, e); 999 return oopDesc::equals(ret, e); 1000 } UNSAFE_END 1001 1002 UNSAFE_ENTRY(jboolean, Unsafe_CompareAndSetInt(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jint e, jint x)) { 1003 oop p = JNIHandles::resolve(obj); 1004 if (p == NULL) { 1005 volatile jint* addr = (volatile jint*)index_oop_from_field_offset_long(p, offset); 1006 return RawAccess<>::atomic_cmpxchg(x, addr, e) == e; 1007 } else { 1008 assert_field_offset_sane(p, offset); 1009 return HeapAccess<>::atomic_cmpxchg_at(x, p, (ptrdiff_t)offset, e) == e; 1010 } 1011 } UNSAFE_END 1012 1013 UNSAFE_ENTRY(jboolean, Unsafe_CompareAndSetLong(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jlong e, jlong x)) { 1014 oop p = JNIHandles::resolve(obj); 1015 if (p == NULL) { 1016 volatile jlong* addr = (volatile jlong*)index_oop_from_field_offset_long(p, offset); 1017 return RawAccess<>::atomic_cmpxchg(x, addr, e) == e; 1018 } else { 1019 assert_field_offset_sane(p, offset); 1020 return HeapAccess<>::atomic_cmpxchg_at(x, p, (ptrdiff_t)offset, e) == e; 1021 } 1022 } UNSAFE_END 1023 1024 static void post_thread_park_event(EventThreadPark* event, const oop obj, jlong timeout) { 1025 assert(event != NULL, "invariant"); 1026 assert(event->should_commit(), "invariant"); 1027 event->set_parkedClass((obj != NULL) ? obj->klass() : NULL); 1028 event->set_timeout(timeout); 1029 event->set_address((obj != NULL) ? (u8)cast_from_oop<uintptr_t>(obj) : 0); 1030 event->commit(); 1031 } 1032 1033 UNSAFE_ENTRY(void, Unsafe_Park(JNIEnv *env, jobject unsafe, jboolean isAbsolute, jlong time)) { 1034 HOTSPOT_THREAD_PARK_BEGIN((uintptr_t) thread->parker(), (int) isAbsolute, time); 1035 EventThreadPark event; 1036 1037 JavaThreadParkedState jtps(thread, time != 0); 1038 thread->parker()->park(isAbsolute != 0, time); 1039 if (event.should_commit()) { 1040 post_thread_park_event(&event, thread->current_park_blocker(), time); 1041 } 1042 HOTSPOT_THREAD_PARK_END((uintptr_t) thread->parker()); 1043 } UNSAFE_END 1044 1045 UNSAFE_ENTRY(void, Unsafe_Unpark(JNIEnv *env, jobject unsafe, jobject jthread)) { 1046 Parker* p = NULL; 1047 1048 if (jthread != NULL) { 1049 ThreadsListHandle tlh; 1050 JavaThread* thr = NULL; 1051 oop java_thread = NULL; 1052 (void) tlh.cv_internal_thread_to_JavaThread(jthread, &thr, &java_thread); 1053 if (java_thread != NULL) { 1054 // This is a valid oop. 1055 jlong lp = java_lang_Thread::park_event(java_thread); 1056 if (lp != 0) { 1057 // This cast is OK even though the jlong might have been read 1058 // non-atomically on 32bit systems, since there, one word will 1059 // always be zero anyway and the value set is always the same 1060 p = (Parker*)addr_from_java(lp); 1061 } else { 1062 // Not cached in the java.lang.Thread oop yet (could be an 1063 // older version of library). 1064 if (thr != NULL) { 1065 // The JavaThread is alive. 1066 p = thr->parker(); 1067 if (p != NULL) { 1068 // Cache the Parker in the java.lang.Thread oop for next time. 1069 java_lang_Thread::set_park_event(java_thread, addr_to_java(p)); 1070 } 1071 } 1072 } 1073 } 1074 } // ThreadsListHandle is destroyed here. 1075 1076 if (p != NULL) { 1077 HOTSPOT_THREAD_UNPARK((uintptr_t) p); 1078 p->unpark(); 1079 } 1080 } UNSAFE_END 1081 1082 UNSAFE_ENTRY(jint, Unsafe_GetLoadAverage0(JNIEnv *env, jobject unsafe, jdoubleArray loadavg, jint nelem)) { 1083 const int max_nelem = 3; 1084 double la[max_nelem]; 1085 jint ret; 1086 1087 typeArrayOop a = typeArrayOop(JNIHandles::resolve_non_null(loadavg)); 1088 assert(a->is_typeArray(), "must be type array"); 1089 1090 ret = os::loadavg(la, nelem); 1091 if (ret == -1) { 1092 return -1; 1093 } 1094 1095 // if successful, ret is the number of samples actually retrieved. 1096 assert(ret >= 0 && ret <= max_nelem, "Unexpected loadavg return value"); 1097 switch(ret) { 1098 case 3: a->double_at_put(2, (jdouble)la[2]); // fall through 1099 case 2: a->double_at_put(1, (jdouble)la[1]); // fall through 1100 case 1: a->double_at_put(0, (jdouble)la[0]); break; 1101 } 1102 1103 return ret; 1104 } UNSAFE_END 1105 1106 1107 /// JVM_RegisterUnsafeMethods 1108 1109 #define ADR "J" 1110 1111 #define LANG "Ljava/lang/" 1112 1113 #define OBJ LANG "Object;" 1114 #define CLS LANG "Class;" 1115 #define FLD LANG "reflect/Field;" 1116 #define THR LANG "Throwable;" 1117 1118 #define DC_Args LANG "String;[BII" LANG "ClassLoader;" "Ljava/security/ProtectionDomain;" 1119 #define DAC_Args CLS "[B[" OBJ 1120 1121 #define CC (char*) /*cast a literal from (const char*)*/ 1122 #define FN_PTR(f) CAST_FROM_FN_PTR(void*, &f) 1123 1124 #define DECLARE_GETPUTOOP(Type, Desc) \ 1125 {CC "get" #Type, CC "(" OBJ "J)" #Desc, FN_PTR(Unsafe_Get##Type)}, \ 1126 {CC "put" #Type, CC "(" OBJ "J" #Desc ")V", FN_PTR(Unsafe_Put##Type)}, \ 1127 {CC "get" #Type "Volatile", CC "(" OBJ "J)" #Desc, FN_PTR(Unsafe_Get##Type##Volatile)}, \ 1128 {CC "put" #Type "Volatile", CC "(" OBJ "J" #Desc ")V", FN_PTR(Unsafe_Put##Type##Volatile)} 1129 1130 1131 static JNINativeMethod jdk_internal_misc_Unsafe_methods[] = { 1132 {CC "getReference", CC "(" OBJ "J)" OBJ "", FN_PTR(Unsafe_GetReference)}, 1133 {CC "putReference", CC "(" OBJ "J" OBJ ")V", FN_PTR(Unsafe_PutReference)}, 1134 {CC "getReferenceVolatile", CC "(" OBJ "J)" OBJ, FN_PTR(Unsafe_GetReferenceVolatile)}, 1135 {CC "putReferenceVolatile", CC "(" OBJ "J" OBJ ")V", FN_PTR(Unsafe_PutReferenceVolatile)}, 1136 1137 {CC "isFlattenedArray", CC "(" CLS ")Z", FN_PTR(Unsafe_IsFlattenedArray)}, 1138 {CC "getValue", CC "(" OBJ "J" CLS ")" OBJ "", FN_PTR(Unsafe_GetValue)}, 1139 {CC "putValue", CC "(" OBJ "J" CLS OBJ ")V", FN_PTR(Unsafe_PutValue)}, 1140 1141 {CC "getUncompressedObject", CC "(" ADR ")" OBJ, FN_PTR(Unsafe_GetUncompressedObject)}, 1142 1143 DECLARE_GETPUTOOP(Boolean, Z), 1144 DECLARE_GETPUTOOP(Byte, B), 1145 DECLARE_GETPUTOOP(Short, S), 1146 DECLARE_GETPUTOOP(Char, C), 1147 DECLARE_GETPUTOOP(Int, I), 1148 DECLARE_GETPUTOOP(Long, J), 1149 DECLARE_GETPUTOOP(Float, F), 1150 DECLARE_GETPUTOOP(Double, D), 1151 1152 {CC "allocateMemory0", CC "(J)" ADR, FN_PTR(Unsafe_AllocateMemory0)}, 1153 {CC "reallocateMemory0", CC "(" ADR "J)" ADR, FN_PTR(Unsafe_ReallocateMemory0)}, 1154 {CC "freeMemory0", CC "(" ADR ")V", FN_PTR(Unsafe_FreeMemory0)}, 1155 1156 {CC "objectFieldOffset0", CC "(" FLD ")J", FN_PTR(Unsafe_ObjectFieldOffset0)}, 1157 {CC "objectFieldOffset1", CC "(" CLS LANG "String;)J", FN_PTR(Unsafe_ObjectFieldOffset1)}, 1158 {CC "staticFieldOffset0", CC "(" FLD ")J", FN_PTR(Unsafe_StaticFieldOffset0)}, 1159 {CC "staticFieldBase0", CC "(" FLD ")" OBJ, FN_PTR(Unsafe_StaticFieldBase0)}, 1160 {CC "ensureClassInitialized0", CC "(" CLS ")V", FN_PTR(Unsafe_EnsureClassInitialized0)}, 1161 {CC "arrayBaseOffset0", CC "(" CLS ")I", FN_PTR(Unsafe_ArrayBaseOffset0)}, 1162 {CC "arrayIndexScale0", CC "(" CLS ")I", FN_PTR(Unsafe_ArrayIndexScale0)}, 1163 {CC "addressSize0", CC "()I", FN_PTR(Unsafe_AddressSize0)}, 1164 {CC "pageSize", CC "()I", FN_PTR(Unsafe_PageSize)}, 1165 1166 {CC "defineClass0", CC "(" DC_Args ")" CLS, FN_PTR(Unsafe_DefineClass0)}, 1167 {CC "allocateInstance", CC "(" CLS ")" OBJ, FN_PTR(Unsafe_AllocateInstance)}, 1168 {CC "throwException", CC "(" THR ")V", FN_PTR(Unsafe_ThrowException)}, 1169 {CC "compareAndSetReference",CC "(" OBJ "J" OBJ "" OBJ ")Z", FN_PTR(Unsafe_CompareAndSetReference)}, 1170 {CC "compareAndSetInt", CC "(" OBJ "J""I""I"")Z", FN_PTR(Unsafe_CompareAndSetInt)}, 1171 {CC "compareAndSetLong", CC "(" OBJ "J""J""J"")Z", FN_PTR(Unsafe_CompareAndSetLong)}, 1172 {CC "compareAndExchangeReference", CC "(" OBJ "J" OBJ "" OBJ ")" OBJ, FN_PTR(Unsafe_CompareAndExchangeReference)}, 1173 {CC "compareAndExchangeInt", CC "(" OBJ "J""I""I"")I", FN_PTR(Unsafe_CompareAndExchangeInt)}, 1174 {CC "compareAndExchangeLong", CC "(" OBJ "J""J""J"")J", FN_PTR(Unsafe_CompareAndExchangeLong)}, 1175 1176 {CC "park", CC "(ZJ)V", FN_PTR(Unsafe_Park)}, 1177 {CC "unpark", CC "(" OBJ ")V", FN_PTR(Unsafe_Unpark)}, 1178 1179 {CC "getLoadAverage0", CC "([DI)I", FN_PTR(Unsafe_GetLoadAverage0)}, 1180 1181 {CC "copyMemory0", CC "(" OBJ "J" OBJ "JJ)V", FN_PTR(Unsafe_CopyMemory0)}, 1182 {CC "copySwapMemory0", CC "(" OBJ "J" OBJ "JJJ)V", FN_PTR(Unsafe_CopySwapMemory0)}, 1183 {CC "setMemory0", CC "(" OBJ "JJB)V", FN_PTR(Unsafe_SetMemory0)}, 1184 1185 {CC "defineAnonymousClass0", CC "(" DAC_Args ")" CLS, FN_PTR(Unsafe_DefineAnonymousClass0)}, 1186 1187 {CC "shouldBeInitialized0", CC "(" CLS ")Z", FN_PTR(Unsafe_ShouldBeInitialized0)}, 1188 1189 {CC "loadFence", CC "()V", FN_PTR(Unsafe_LoadFence)}, 1190 {CC "storeFence", CC "()V", FN_PTR(Unsafe_StoreFence)}, 1191 {CC "fullFence", CC "()V", FN_PTR(Unsafe_FullFence)}, 1192 1193 {CC "isBigEndian0", CC "()Z", FN_PTR(Unsafe_isBigEndian0)}, 1194 {CC "unalignedAccess0", CC "()Z", FN_PTR(Unsafe_unalignedAccess0)} 1195 }; 1196 1197 #undef CC 1198 #undef FN_PTR 1199 1200 #undef ADR 1201 #undef LANG 1202 #undef OBJ 1203 #undef CLS 1204 #undef FLD 1205 #undef THR 1206 #undef DC_Args 1207 #undef DAC_Args 1208 1209 #undef DECLARE_GETPUTOOP 1210 1211 1212 // This function is exported, used by NativeLookup. 1213 // The Unsafe_xxx functions above are called only from the interpreter. 1214 // The optimizer looks at names and signatures to recognize 1215 // individual functions. 1216 1217 JVM_ENTRY(void, JVM_RegisterJDKInternalMiscUnsafeMethods(JNIEnv *env, jclass unsafeclass)) { 1218 ThreadToNativeFromVM ttnfv(thread); 1219 1220 int ok = env->RegisterNatives(unsafeclass, jdk_internal_misc_Unsafe_methods, sizeof(jdk_internal_misc_Unsafe_methods)/sizeof(JNINativeMethod)); 1221 guarantee(ok == 0, "register jdk.internal.misc.Unsafe natives"); 1222 } JVM_END