1 /* 2 * Copyright (c) 2000, 2015, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 * 23 */ 24 25 #include "precompiled.hpp" 26 #include "classfile/classFileStream.hpp" 27 #include "classfile/vmSymbols.hpp" 28 #include "memory/allocation.inline.hpp" 29 #include "oops/objArrayOop.inline.hpp" 30 #include "oops/oop.inline.hpp" 31 #include "prims/jni.h" 32 #include "prims/jvm.h" 33 #include "runtime/atomic.inline.hpp" 34 #include "runtime/globals.hpp" 35 #include "runtime/interfaceSupport.hpp" 36 #include "runtime/orderAccess.inline.hpp" 37 #include "runtime/reflection.hpp" 38 #include "runtime/vm_version.hpp" 39 #include "services/threadService.hpp" 40 #include "trace/tracing.hpp" 41 #include "utilities/copy.hpp" 42 #include "utilities/dtrace.hpp" 43 #include "utilities/macros.hpp" 44 #if INCLUDE_ALL_GCS 45 #include "gc/g1/g1SATBCardTableModRefBS.hpp" 46 #endif // INCLUDE_ALL_GCS 47 48 /* 49 * Implementation of class Unsafe 50 */ 51 52 53 #define MAX_OBJECT_SIZE \ 54 ( arrayOopDesc::header_size(T_DOUBLE) * HeapWordSize \ 55 + ((julong)max_jint * sizeof(double)) ) 56 57 58 #define UNSAFE_ENTRY(result_type, header) \ 59 JVM_ENTRY(result_type, header) 60 61 // Can't use UNSAFE_LEAF because it has the signature of a straight 62 // call into the runtime (just like JVM_LEAF, funny that) but it's 63 // called like a Java Native and thus the wrapper built for it passes 64 // arguments like a JNI call. It expects those arguments to be popped 65 // from the stack on Intel like all good JNI args are, and adjusts the 66 // stack according. Since the JVM_LEAF call expects no extra 67 // arguments the stack isn't popped in the C code, is pushed by the 68 // wrapper and we get sick. 69 //#define UNSAFE_LEAF(result_type, header) \ 70 // JVM_LEAF(result_type, header) 71 72 #define UNSAFE_END JVM_END 73 74 #define UnsafeWrapper(arg) /*nothing, for the present*/ 75 76 77 inline void* addr_from_java(jlong addr) { 78 // This assert fails in a variety of ways on 32-bit systems. 79 // It is impossible to predict whether native code that converts 80 // pointers to longs will sign-extend or zero-extend the addresses. 81 //assert(addr == (uintptr_t)addr, "must not be odd high bits"); 82 return (void*)(uintptr_t)addr; 83 } 84 85 inline jlong addr_to_java(void* p) { 86 assert(p == (void*)(uintptr_t)p, "must not be odd high bits"); 87 return (uintptr_t)p; 88 } 89 90 91 // Note: The VM's obj_field and related accessors use byte-scaled 92 // ("unscaled") offsets, just as the unsafe methods do. 93 94 // However, the method Unsafe.fieldOffset explicitly declines to 95 // guarantee this. The field offset values manipulated by the Java user 96 // through the Unsafe API are opaque cookies that just happen to be byte 97 // offsets. We represent this state of affairs by passing the cookies 98 // through conversion functions when going between the VM and the Unsafe API. 99 // The conversion functions just happen to be no-ops at present. 100 101 inline jlong field_offset_to_byte_offset(jlong field_offset) { 102 return field_offset; 103 } 104 105 inline jlong field_offset_from_byte_offset(jlong byte_offset) { 106 return byte_offset; 107 } 108 109 inline jint invocation_key_from_method_slot(jint slot) { 110 return slot; 111 } 112 113 inline jint invocation_key_to_method_slot(jint key) { 114 return key; 115 } 116 117 inline void* index_oop_from_field_offset_long(oop p, jlong field_offset) { 118 jlong byte_offset = field_offset_to_byte_offset(field_offset); 119 #ifdef ASSERT 120 if (p != NULL) { 121 assert(byte_offset >= 0 && byte_offset <= (jlong)MAX_OBJECT_SIZE, "sane offset"); 122 if (byte_offset == (jint)byte_offset) { 123 void* ptr_plus_disp = (address)p + byte_offset; 124 assert((void*)p->obj_field_addr<oop>((jint)byte_offset) == ptr_plus_disp, 125 "raw [ptr+disp] must be consistent with oop::field_base"); 126 } 127 jlong p_size = HeapWordSize * (jlong)(p->size()); 128 assert(byte_offset < p_size, "Unsafe access: offset " INT64_FORMAT " > object's size " INT64_FORMAT, byte_offset, p_size); 129 } 130 #endif 131 if (sizeof(char*) == sizeof(jint)) // (this constant folds!) 132 return (address)p + (jint) byte_offset; 133 else 134 return (address)p + byte_offset; 135 } 136 137 // Externally callable versions: 138 // (Use these in compiler intrinsics which emulate unsafe primitives.) 139 jlong Unsafe_field_offset_to_byte_offset(jlong field_offset) { 140 return field_offset; 141 } 142 jlong Unsafe_field_offset_from_byte_offset(jlong byte_offset) { 143 return byte_offset; 144 } 145 jint Unsafe_invocation_key_from_method_slot(jint slot) { 146 return invocation_key_from_method_slot(slot); 147 } 148 jint Unsafe_invocation_key_to_method_slot(jint key) { 149 return invocation_key_to_method_slot(key); 150 } 151 152 153 ///// Data in the Java heap. 154 155 #define GET_FIELD(obj, offset, type_name, v) \ 156 oop p = JNIHandles::resolve(obj); \ 157 type_name v = *(type_name*)index_oop_from_field_offset_long(p, offset) 158 159 #define SET_FIELD(obj, offset, type_name, x) \ 160 oop p = JNIHandles::resolve(obj); \ 161 *(type_name*)index_oop_from_field_offset_long(p, offset) = x 162 163 #define GET_FIELD_VOLATILE(obj, offset, type_name, v) \ 164 oop p = JNIHandles::resolve(obj); \ 165 if (support_IRIW_for_not_multiple_copy_atomic_cpu) { \ 166 OrderAccess::fence(); \ 167 } \ 168 volatile type_name v = OrderAccess::load_acquire((volatile type_name*)index_oop_from_field_offset_long(p, offset)); 169 170 #define SET_FIELD_VOLATILE(obj, offset, type_name, x) \ 171 oop p = JNIHandles::resolve(obj); \ 172 OrderAccess::release_store_fence((volatile type_name*)index_oop_from_field_offset_long(p, offset), x); 173 174 175 // Get/SetObject must be special-cased, since it works with handles. 176 177 // These functions allow a null base pointer with an arbitrary address. 178 // But if the base pointer is non-null, the offset should make some sense. 179 // That is, it should be in the range [0, MAX_OBJECT_SIZE]. 180 UNSAFE_ENTRY(jobject, Unsafe_GetObject(JNIEnv *env, jobject unsafe, jobject obj, jlong offset)) 181 UnsafeWrapper("Unsafe_GetObject"); 182 oop p = JNIHandles::resolve(obj); 183 oop v; 184 if (UseCompressedOops) { 185 narrowOop n = *(narrowOop*)index_oop_from_field_offset_long(p, offset); 186 v = oopDesc::decode_heap_oop(n); 187 } else { 188 v = *(oop*)index_oop_from_field_offset_long(p, offset); 189 } 190 jobject ret = JNIHandles::make_local(env, v); 191 #if INCLUDE_ALL_GCS 192 // We could be accessing the referent field in a reference 193 // object. If G1 is enabled then we need to register non-null 194 // referent with the SATB barrier. 195 if (UseG1GC) { 196 bool needs_barrier = false; 197 198 if (ret != NULL) { 199 if (offset == java_lang_ref_Reference::referent_offset && obj != NULL) { 200 oop o = JNIHandles::resolve(obj); 201 Klass* k = o->klass(); 202 if (InstanceKlass::cast(k)->reference_type() != REF_NONE) { 203 assert(InstanceKlass::cast(k)->is_subclass_of(SystemDictionary::Reference_klass()), "sanity"); 204 needs_barrier = true; 205 } 206 } 207 } 208 209 if (needs_barrier) { 210 oop referent = JNIHandles::resolve(ret); 211 G1SATBCardTableModRefBS::enqueue(referent); 212 } 213 } 214 #endif // INCLUDE_ALL_GCS 215 return ret; 216 UNSAFE_END 217 218 UNSAFE_ENTRY(void, Unsafe_SetObject(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jobject x_h)) 219 UnsafeWrapper("Unsafe_SetObject"); 220 oop x = JNIHandles::resolve(x_h); 221 oop p = JNIHandles::resolve(obj); 222 if (UseCompressedOops) { 223 oop_store((narrowOop*)index_oop_from_field_offset_long(p, offset), x); 224 } else { 225 oop_store((oop*)index_oop_from_field_offset_long(p, offset), x); 226 } 227 UNSAFE_END 228 229 UNSAFE_ENTRY(jobject, Unsafe_GetObjectVolatile(JNIEnv *env, jobject unsafe, jobject obj, jlong offset)) 230 UnsafeWrapper("Unsafe_GetObjectVolatile"); 231 oop p = JNIHandles::resolve(obj); 232 void* addr = index_oop_from_field_offset_long(p, offset); 233 volatile oop v; 234 if (UseCompressedOops) { 235 volatile narrowOop n = *(volatile narrowOop*) addr; 236 (void)const_cast<oop&>(v = oopDesc::decode_heap_oop(n)); 237 } else { 238 (void)const_cast<oop&>(v = *(volatile oop*) addr); 239 } 240 OrderAccess::acquire(); 241 return JNIHandles::make_local(env, v); 242 UNSAFE_END 243 244 UNSAFE_ENTRY(void, Unsafe_SetObjectVolatile(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jobject x_h)) 245 UnsafeWrapper("Unsafe_SetObjectVolatile"); 246 oop x = JNIHandles::resolve(x_h); 247 oop p = JNIHandles::resolve(obj); 248 void* addr = index_oop_from_field_offset_long(p, offset); 249 OrderAccess::release(); 250 if (UseCompressedOops) { 251 oop_store((narrowOop*)addr, x); 252 } else { 253 oop_store((oop*)addr, x); 254 } 255 OrderAccess::fence(); 256 UNSAFE_END 257 258 UNSAFE_ENTRY(jobject, Unsafe_GetUncompressedObject(JNIEnv *env, jobject unsafe, jlong addr)) 259 UnsafeWrapper("Unsafe_GetUncompressedObject"); 260 oop v = *(oop*) (address) addr; 261 return JNIHandles::make_local(env, v); 262 UNSAFE_END 263 264 UNSAFE_ENTRY(jclass, Unsafe_GetJavaMirror(JNIEnv *env, jobject unsafe, jlong metaspace_klass)) 265 UnsafeWrapper("Unsafe_GetJavaMirror"); 266 Klass* klass = (Klass*) (address) metaspace_klass; 267 return (jclass) JNIHandles::make_local(klass->java_mirror()); 268 UNSAFE_END 269 270 UNSAFE_ENTRY(jlong, Unsafe_GetKlassPointer(JNIEnv *env, jobject unsafe, jobject obj)) 271 UnsafeWrapper("Unsafe_GetKlassPointer"); 272 oop o = JNIHandles::resolve(obj); 273 jlong klass = (jlong) (address) o->klass(); 274 return klass; 275 UNSAFE_END 276 277 #ifndef SUPPORTS_NATIVE_CX8 278 279 // VM_Version::supports_cx8() is a surrogate for 'supports atomic long memory ops'. 280 // 281 // On platforms which do not support atomic compare-and-swap of jlong (8 byte) 282 // values we have to use a lock-based scheme to enforce atomicity. This has to be 283 // applied to all Unsafe operations that set the value of a jlong field. Even so 284 // the compareAndSwapLong operation will not be atomic with respect to direct stores 285 // to the field from Java code. It is important therefore that any Java code that 286 // utilizes these Unsafe jlong operations does not perform direct stores. To permit 287 // direct loads of the field from Java code we must also use Atomic::store within the 288 // locked regions. And for good measure, in case there are direct stores, we also 289 // employ Atomic::load within those regions. Note that the field in question must be 290 // volatile and so must have atomic load/store accesses applied at the Java level. 291 // 292 // The locking scheme could utilize a range of strategies for controlling the locking 293 // granularity: from a lock per-field through to a single global lock. The latter is 294 // the simplest and is used for the current implementation. Note that the Java object 295 // that contains the field, can not, in general, be used for locking. To do so can lead 296 // to deadlocks as we may introduce locking into what appears to the Java code to be a 297 // lock-free path. 298 // 299 // As all the locked-regions are very short and themselves non-blocking we can treat 300 // them as leaf routines and elide safepoint checks (ie we don't perform any thread 301 // state transitions even when blocking for the lock). Note that if we do choose to 302 // add safepoint checks and thread state transitions, we must ensure that we calculate 303 // the address of the field _after_ we have acquired the lock, else the object may have 304 // been moved by the GC 305 306 UNSAFE_ENTRY(jlong, Unsafe_GetLongVolatile(JNIEnv *env, jobject unsafe, jobject obj, jlong offset)) 307 UnsafeWrapper("Unsafe_GetLongVolatile"); 308 { 309 if (VM_Version::supports_cx8()) { 310 GET_FIELD_VOLATILE(obj, offset, jlong, v); 311 return v; 312 } 313 else { 314 Handle p (THREAD, JNIHandles::resolve(obj)); 315 jlong* addr = (jlong*)(index_oop_from_field_offset_long(p(), offset)); 316 MutexLockerEx mu(UnsafeJlong_lock, Mutex::_no_safepoint_check_flag); 317 jlong value = Atomic::load(addr); 318 return value; 319 } 320 } 321 UNSAFE_END 322 323 UNSAFE_ENTRY(void, Unsafe_SetLongVolatile(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jlong x)) 324 UnsafeWrapper("Unsafe_SetLongVolatile"); 325 { 326 if (VM_Version::supports_cx8()) { 327 SET_FIELD_VOLATILE(obj, offset, jlong, x); 328 } 329 else { 330 Handle p (THREAD, JNIHandles::resolve(obj)); 331 jlong* addr = (jlong*)(index_oop_from_field_offset_long(p(), offset)); 332 MutexLockerEx mu(UnsafeJlong_lock, Mutex::_no_safepoint_check_flag); 333 Atomic::store(x, addr); 334 } 335 } 336 UNSAFE_END 337 338 #endif // not SUPPORTS_NATIVE_CX8 339 340 UNSAFE_ENTRY(jboolean, Unsafe_isBigEndian0(JNIEnv *env, jobject unsafe)) 341 UnsafeWrapper("Unsafe_IsBigEndian0"); 342 { 343 #ifdef VM_LITTLE_ENDIAN 344 return false; 345 #else 346 return true; 347 #endif 348 } 349 UNSAFE_END 350 351 UNSAFE_ENTRY(jint, Unsafe_unalignedAccess0(JNIEnv *env, jobject unsafe)) 352 UnsafeWrapper("Unsafe_UnalignedAccess0"); 353 { 354 return UseUnalignedAccesses; 355 } 356 UNSAFE_END 357 358 #define DEFINE_GETSETOOP(jboolean, Boolean) \ 359 \ 360 UNSAFE_ENTRY(jboolean, Unsafe_Get##Boolean##140(JNIEnv *env, jobject unsafe, jobject obj, jint offset)) \ 361 UnsafeWrapper("Unsafe_Get"#Boolean); \ 362 if (obj == NULL) THROW_0(vmSymbols::java_lang_NullPointerException()); \ 363 GET_FIELD(obj, offset, jboolean, v); \ 364 return v; \ 365 UNSAFE_END \ 366 \ 367 UNSAFE_ENTRY(void, Unsafe_Set##Boolean##140(JNIEnv *env, jobject unsafe, jobject obj, jint offset, jboolean x)) \ 368 UnsafeWrapper("Unsafe_Set"#Boolean); \ 369 if (obj == NULL) THROW(vmSymbols::java_lang_NullPointerException()); \ 370 SET_FIELD(obj, offset, jboolean, x); \ 371 UNSAFE_END \ 372 \ 373 UNSAFE_ENTRY(jboolean, Unsafe_Get##Boolean(JNIEnv *env, jobject unsafe, jobject obj, jlong offset)) \ 374 UnsafeWrapper("Unsafe_Get"#Boolean); \ 375 GET_FIELD(obj, offset, jboolean, v); \ 376 return v; \ 377 UNSAFE_END \ 378 \ 379 UNSAFE_ENTRY(void, Unsafe_Set##Boolean(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jboolean x)) \ 380 UnsafeWrapper("Unsafe_Set"#Boolean); \ 381 SET_FIELD(obj, offset, jboolean, x); \ 382 UNSAFE_END \ 383 \ 384 // END DEFINE_GETSETOOP. 385 386 DEFINE_GETSETOOP(jboolean, Boolean) 387 DEFINE_GETSETOOP(jbyte, Byte) 388 DEFINE_GETSETOOP(jshort, Short); 389 DEFINE_GETSETOOP(jchar, Char); 390 DEFINE_GETSETOOP(jint, Int); 391 DEFINE_GETSETOOP(jlong, Long); 392 DEFINE_GETSETOOP(jfloat, Float); 393 DEFINE_GETSETOOP(jdouble, Double); 394 395 #undef DEFINE_GETSETOOP 396 397 #define DEFINE_GETSETOOP_VOLATILE(jboolean, Boolean) \ 398 \ 399 UNSAFE_ENTRY(jboolean, Unsafe_Get##Boolean##Volatile(JNIEnv *env, jobject unsafe, jobject obj, jlong offset)) \ 400 UnsafeWrapper("Unsafe_Get"#Boolean); \ 401 GET_FIELD_VOLATILE(obj, offset, jboolean, v); \ 402 return v; \ 403 UNSAFE_END \ 404 \ 405 UNSAFE_ENTRY(void, Unsafe_Set##Boolean##Volatile(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jboolean x)) \ 406 UnsafeWrapper("Unsafe_Set"#Boolean); \ 407 SET_FIELD_VOLATILE(obj, offset, jboolean, x); \ 408 UNSAFE_END \ 409 \ 410 // END DEFINE_GETSETOOP_VOLATILE. 411 412 DEFINE_GETSETOOP_VOLATILE(jboolean, Boolean) 413 DEFINE_GETSETOOP_VOLATILE(jbyte, Byte) 414 DEFINE_GETSETOOP_VOLATILE(jshort, Short); 415 DEFINE_GETSETOOP_VOLATILE(jchar, Char); 416 DEFINE_GETSETOOP_VOLATILE(jint, Int); 417 DEFINE_GETSETOOP_VOLATILE(jfloat, Float); 418 DEFINE_GETSETOOP_VOLATILE(jdouble, Double); 419 420 #ifdef SUPPORTS_NATIVE_CX8 421 DEFINE_GETSETOOP_VOLATILE(jlong, Long); 422 #endif 423 424 #undef DEFINE_GETSETOOP_VOLATILE 425 426 // The non-intrinsified versions of setOrdered just use setVolatile 427 428 UNSAFE_ENTRY(void, Unsafe_SetOrderedInt(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jint x)) 429 UnsafeWrapper("Unsafe_SetOrderedInt"); 430 SET_FIELD_VOLATILE(obj, offset, jint, x); 431 UNSAFE_END 432 433 UNSAFE_ENTRY(void, Unsafe_SetOrderedObject(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jobject x_h)) 434 UnsafeWrapper("Unsafe_SetOrderedObject"); 435 oop x = JNIHandles::resolve(x_h); 436 oop p = JNIHandles::resolve(obj); 437 void* addr = index_oop_from_field_offset_long(p, offset); 438 OrderAccess::release(); 439 if (UseCompressedOops) { 440 oop_store((narrowOop*)addr, x); 441 } else { 442 oop_store((oop*)addr, x); 443 } 444 OrderAccess::fence(); 445 UNSAFE_END 446 447 UNSAFE_ENTRY(void, Unsafe_SetOrderedLong(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jlong x)) 448 UnsafeWrapper("Unsafe_SetOrderedLong"); 449 #ifdef SUPPORTS_NATIVE_CX8 450 SET_FIELD_VOLATILE(obj, offset, jlong, x); 451 #else 452 // Keep old code for platforms which may not have atomic long (8 bytes) instructions 453 { 454 if (VM_Version::supports_cx8()) { 455 SET_FIELD_VOLATILE(obj, offset, jlong, x); 456 } 457 else { 458 Handle p (THREAD, JNIHandles::resolve(obj)); 459 jlong* addr = (jlong*)(index_oop_from_field_offset_long(p(), offset)); 460 MutexLockerEx mu(UnsafeJlong_lock, Mutex::_no_safepoint_check_flag); 461 Atomic::store(x, addr); 462 } 463 } 464 #endif 465 UNSAFE_END 466 467 UNSAFE_ENTRY(void, Unsafe_LoadFence(JNIEnv *env, jobject unsafe)) 468 UnsafeWrapper("Unsafe_LoadFence"); 469 OrderAccess::acquire(); 470 UNSAFE_END 471 472 UNSAFE_ENTRY(void, Unsafe_StoreFence(JNIEnv *env, jobject unsafe)) 473 UnsafeWrapper("Unsafe_StoreFence"); 474 OrderAccess::release(); 475 UNSAFE_END 476 477 UNSAFE_ENTRY(void, Unsafe_FullFence(JNIEnv *env, jobject unsafe)) 478 UnsafeWrapper("Unsafe_FullFence"); 479 OrderAccess::fence(); 480 UNSAFE_END 481 482 ////// Data in the C heap. 483 484 // Note: These do not throw NullPointerException for bad pointers. 485 // They just crash. Only a oop base pointer can generate a NullPointerException. 486 // 487 #define DEFINE_GETSETNATIVE(java_type, Type, native_type) \ 488 \ 489 UNSAFE_ENTRY(java_type, Unsafe_GetNative##Type(JNIEnv *env, jobject unsafe, jlong addr)) \ 490 UnsafeWrapper("Unsafe_GetNative"#Type); \ 491 void* p = addr_from_java(addr); \ 492 JavaThread* t = JavaThread::current(); \ 493 t->set_doing_unsafe_access(true); \ 494 java_type x = *(volatile native_type*)p; \ 495 t->set_doing_unsafe_access(false); \ 496 return x; \ 497 UNSAFE_END \ 498 \ 499 UNSAFE_ENTRY(void, Unsafe_SetNative##Type(JNIEnv *env, jobject unsafe, jlong addr, java_type x)) \ 500 UnsafeWrapper("Unsafe_SetNative"#Type); \ 501 JavaThread* t = JavaThread::current(); \ 502 t->set_doing_unsafe_access(true); \ 503 void* p = addr_from_java(addr); \ 504 *(volatile native_type*)p = x; \ 505 t->set_doing_unsafe_access(false); \ 506 UNSAFE_END \ 507 \ 508 // END DEFINE_GETSETNATIVE. 509 510 DEFINE_GETSETNATIVE(jbyte, Byte, signed char) 511 DEFINE_GETSETNATIVE(jshort, Short, signed short); 512 DEFINE_GETSETNATIVE(jchar, Char, unsigned short); 513 DEFINE_GETSETNATIVE(jint, Int, jint); 514 // no long -- handled specially 515 DEFINE_GETSETNATIVE(jfloat, Float, float); 516 DEFINE_GETSETNATIVE(jdouble, Double, double); 517 518 #undef DEFINE_GETSETNATIVE 519 520 UNSAFE_ENTRY(jlong, Unsafe_GetNativeLong(JNIEnv *env, jobject unsafe, jlong addr)) 521 UnsafeWrapper("Unsafe_GetNativeLong"); 522 JavaThread* t = JavaThread::current(); 523 // We do it this way to avoid problems with access to heap using 64 524 // bit loads, as jlong in heap could be not 64-bit aligned, and on 525 // some CPUs (SPARC) it leads to SIGBUS. 526 t->set_doing_unsafe_access(true); 527 void* p = addr_from_java(addr); 528 jlong x; 529 if (((intptr_t)p & 7) == 0) { 530 // jlong is aligned, do a volatile access 531 x = *(volatile jlong*)p; 532 } else { 533 jlong_accessor acc; 534 acc.words[0] = ((volatile jint*)p)[0]; 535 acc.words[1] = ((volatile jint*)p)[1]; 536 x = acc.long_value; 537 } 538 t->set_doing_unsafe_access(false); 539 return x; 540 UNSAFE_END 541 542 UNSAFE_ENTRY(void, Unsafe_SetNativeLong(JNIEnv *env, jobject unsafe, jlong addr, jlong x)) 543 UnsafeWrapper("Unsafe_SetNativeLong"); 544 JavaThread* t = JavaThread::current(); 545 // see comment for Unsafe_GetNativeLong 546 t->set_doing_unsafe_access(true); 547 void* p = addr_from_java(addr); 548 if (((intptr_t)p & 7) == 0) { 549 // jlong is aligned, do a volatile access 550 *(volatile jlong*)p = x; 551 } else { 552 jlong_accessor acc; 553 acc.long_value = x; 554 ((volatile jint*)p)[0] = acc.words[0]; 555 ((volatile jint*)p)[1] = acc.words[1]; 556 } 557 t->set_doing_unsafe_access(false); 558 UNSAFE_END 559 560 561 UNSAFE_ENTRY(jlong, Unsafe_GetNativeAddress(JNIEnv *env, jobject unsafe, jlong addr)) 562 UnsafeWrapper("Unsafe_GetNativeAddress"); 563 void* p = addr_from_java(addr); 564 return addr_to_java(*(void**)p); 565 UNSAFE_END 566 567 UNSAFE_ENTRY(void, Unsafe_SetNativeAddress(JNIEnv *env, jobject unsafe, jlong addr, jlong x)) 568 UnsafeWrapper("Unsafe_SetNativeAddress"); 569 void* p = addr_from_java(addr); 570 *(void**)p = addr_from_java(x); 571 UNSAFE_END 572 573 574 ////// Allocation requests 575 576 UNSAFE_ENTRY(jobject, Unsafe_AllocateInstance(JNIEnv *env, jobject unsafe, jclass cls)) 577 UnsafeWrapper("Unsafe_AllocateInstance"); 578 { 579 ThreadToNativeFromVM ttnfv(thread); 580 return env->AllocObject(cls); 581 } 582 UNSAFE_END 583 584 UNSAFE_ENTRY(jlong, Unsafe_AllocateMemory(JNIEnv *env, jobject unsafe, jlong size)) 585 UnsafeWrapper("Unsafe_AllocateMemory"); 586 size_t sz = (size_t)size; 587 if (sz != (julong)size || size < 0) { 588 THROW_0(vmSymbols::java_lang_IllegalArgumentException()); 589 } 590 if (sz == 0) { 591 return 0; 592 } 593 sz = round_to(sz, HeapWordSize); 594 void* x = os::malloc(sz, mtInternal); 595 if (x == NULL) { 596 THROW_0(vmSymbols::java_lang_OutOfMemoryError()); 597 } 598 //Copy::fill_to_words((HeapWord*)x, sz / HeapWordSize); 599 return addr_to_java(x); 600 UNSAFE_END 601 602 UNSAFE_ENTRY(jlong, Unsafe_ReallocateMemory(JNIEnv *env, jobject unsafe, jlong addr, jlong size)) 603 UnsafeWrapper("Unsafe_ReallocateMemory"); 604 void* p = addr_from_java(addr); 605 size_t sz = (size_t)size; 606 if (sz != (julong)size || size < 0) { 607 THROW_0(vmSymbols::java_lang_IllegalArgumentException()); 608 } 609 if (sz == 0) { 610 os::free(p); 611 return 0; 612 } 613 sz = round_to(sz, HeapWordSize); 614 void* x = (p == NULL) ? os::malloc(sz, mtInternal) : os::realloc(p, sz, mtInternal); 615 if (x == NULL) { 616 THROW_0(vmSymbols::java_lang_OutOfMemoryError()); 617 } 618 return addr_to_java(x); 619 UNSAFE_END 620 621 UNSAFE_ENTRY(void, Unsafe_FreeMemory(JNIEnv *env, jobject unsafe, jlong addr)) 622 UnsafeWrapper("Unsafe_FreeMemory"); 623 void* p = addr_from_java(addr); 624 if (p == NULL) { 625 return; 626 } 627 os::free(p); 628 UNSAFE_END 629 630 UNSAFE_ENTRY(void, Unsafe_SetMemory(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jlong size, jbyte value)) 631 UnsafeWrapper("Unsafe_SetMemory"); 632 size_t sz = (size_t)size; 633 if (sz != (julong)size || size < 0) { 634 THROW(vmSymbols::java_lang_IllegalArgumentException()); 635 } 636 oop base = JNIHandles::resolve(obj); 637 void* p = index_oop_from_field_offset_long(base, offset); 638 Copy::fill_to_memory_atomic(p, sz, value); 639 UNSAFE_END 640 641 UNSAFE_ENTRY(void, Unsafe_CopyMemory(JNIEnv *env, jobject unsafe, jobject srcObj, jlong srcOffset, jobject dstObj, jlong dstOffset, jlong size)) 642 UnsafeWrapper("Unsafe_CopyMemory"); 643 if (size == 0) { 644 return; 645 } 646 size_t sz = (size_t)size; 647 if (sz != (julong)size || size < 0) { 648 THROW(vmSymbols::java_lang_IllegalArgumentException()); 649 } 650 oop srcp = JNIHandles::resolve(srcObj); 651 oop dstp = JNIHandles::resolve(dstObj); 652 if (dstp != NULL && !dstp->is_typeArray()) { 653 // NYI: This works only for non-oop arrays at present. 654 // Generalizing it would be reasonable, but requires card marking. 655 // Also, autoboxing a Long from 0L in copyMemory(x,y, 0L,z, n) would be bad. 656 THROW(vmSymbols::java_lang_IllegalArgumentException()); 657 } 658 void* src = index_oop_from_field_offset_long(srcp, srcOffset); 659 void* dst = index_oop_from_field_offset_long(dstp, dstOffset); 660 Copy::conjoint_memory_atomic(src, dst, sz); 661 UNSAFE_END 662 663 664 ////// Random queries 665 666 // See comment at file start about UNSAFE_LEAF 667 //UNSAFE_LEAF(jint, Unsafe_AddressSize()) 668 UNSAFE_ENTRY(jint, Unsafe_AddressSize(JNIEnv *env, jobject unsafe)) 669 UnsafeWrapper("Unsafe_AddressSize"); 670 return sizeof(void*); 671 UNSAFE_END 672 673 // See comment at file start about UNSAFE_LEAF 674 //UNSAFE_LEAF(jint, Unsafe_PageSize()) 675 UNSAFE_ENTRY(jint, Unsafe_PageSize(JNIEnv *env, jobject unsafe)) 676 UnsafeWrapper("Unsafe_PageSize"); 677 return os::vm_page_size(); 678 UNSAFE_END 679 680 jint find_field_offset(jobject field, int must_be_static, TRAPS) { 681 if (field == NULL) { 682 THROW_0(vmSymbols::java_lang_NullPointerException()); 683 } 684 685 oop reflected = JNIHandles::resolve_non_null(field); 686 oop mirror = java_lang_reflect_Field::clazz(reflected); 687 Klass* k = java_lang_Class::as_Klass(mirror); 688 int slot = java_lang_reflect_Field::slot(reflected); 689 int modifiers = java_lang_reflect_Field::modifiers(reflected); 690 691 if (must_be_static >= 0) { 692 int really_is_static = ((modifiers & JVM_ACC_STATIC) != 0); 693 if (must_be_static != really_is_static) { 694 THROW_0(vmSymbols::java_lang_IllegalArgumentException()); 695 } 696 } 697 698 int offset = InstanceKlass::cast(k)->field_offset(slot); 699 return field_offset_from_byte_offset(offset); 700 } 701 702 UNSAFE_ENTRY(jlong, Unsafe_ObjectFieldOffset(JNIEnv *env, jobject unsafe, jobject field)) 703 UnsafeWrapper("Unsafe_ObjectFieldOffset"); 704 return find_field_offset(field, 0, THREAD); 705 UNSAFE_END 706 707 UNSAFE_ENTRY(jlong, Unsafe_StaticFieldOffset(JNIEnv *env, jobject unsafe, jobject field)) 708 UnsafeWrapper("Unsafe_StaticFieldOffset"); 709 return find_field_offset(field, 1, THREAD); 710 UNSAFE_END 711 712 UNSAFE_ENTRY(jobject, Unsafe_StaticFieldBaseFromField(JNIEnv *env, jobject unsafe, jobject field)) 713 UnsafeWrapper("Unsafe_StaticFieldBase"); 714 // Note: In this VM implementation, a field address is always a short 715 // offset from the base of a a klass metaobject. Thus, the full dynamic 716 // range of the return type is never used. However, some implementations 717 // might put the static field inside an array shared by many classes, 718 // or even at a fixed address, in which case the address could be quite 719 // large. In that last case, this function would return NULL, since 720 // the address would operate alone, without any base pointer. 721 722 if (field == NULL) THROW_0(vmSymbols::java_lang_NullPointerException()); 723 724 oop reflected = JNIHandles::resolve_non_null(field); 725 oop mirror = java_lang_reflect_Field::clazz(reflected); 726 int modifiers = java_lang_reflect_Field::modifiers(reflected); 727 728 if ((modifiers & JVM_ACC_STATIC) == 0) { 729 THROW_0(vmSymbols::java_lang_IllegalArgumentException()); 730 } 731 732 return JNIHandles::make_local(env, mirror); 733 UNSAFE_END 734 735 UNSAFE_ENTRY(void, Unsafe_EnsureClassInitialized(JNIEnv *env, jobject unsafe, jobject clazz)) { 736 UnsafeWrapper("Unsafe_EnsureClassInitialized"); 737 if (clazz == NULL) { 738 THROW(vmSymbols::java_lang_NullPointerException()); 739 } 740 oop mirror = JNIHandles::resolve_non_null(clazz); 741 742 Klass* klass = java_lang_Class::as_Klass(mirror); 743 if (klass != NULL && klass->should_be_initialized()) { 744 InstanceKlass* k = InstanceKlass::cast(klass); 745 k->initialize(CHECK); 746 } 747 } 748 UNSAFE_END 749 750 UNSAFE_ENTRY(jboolean, Unsafe_ShouldBeInitialized(JNIEnv *env, jobject unsafe, jobject clazz)) { 751 UnsafeWrapper("Unsafe_ShouldBeInitialized"); 752 if (clazz == NULL) { 753 THROW_(vmSymbols::java_lang_NullPointerException(), false); 754 } 755 oop mirror = JNIHandles::resolve_non_null(clazz); 756 Klass* klass = java_lang_Class::as_Klass(mirror); 757 if (klass != NULL && klass->should_be_initialized()) { 758 return true; 759 } 760 return false; 761 } 762 UNSAFE_END 763 764 static void getBaseAndScale(int& base, int& scale, jclass acls, TRAPS) { 765 if (acls == NULL) { 766 THROW(vmSymbols::java_lang_NullPointerException()); 767 } 768 oop mirror = JNIHandles::resolve_non_null(acls); 769 Klass* k = java_lang_Class::as_Klass(mirror); 770 if (k == NULL || !k->is_array_klass()) { 771 THROW(vmSymbols::java_lang_InvalidClassException()); 772 } else if (k->is_objArray_klass()) { 773 base = arrayOopDesc::base_offset_in_bytes(T_OBJECT); 774 scale = heapOopSize; 775 } else if (k->is_typeArray_klass()) { 776 TypeArrayKlass* tak = TypeArrayKlass::cast(k); 777 base = tak->array_header_in_bytes(); 778 assert(base == arrayOopDesc::base_offset_in_bytes(tak->element_type()), "array_header_size semantics ok"); 779 scale = (1 << tak->log2_element_size()); 780 } else { 781 ShouldNotReachHere(); 782 } 783 } 784 785 UNSAFE_ENTRY(jint, Unsafe_ArrayBaseOffset(JNIEnv *env, jobject unsafe, jclass acls)) 786 UnsafeWrapper("Unsafe_ArrayBaseOffset"); 787 int base = 0, scale = 0; 788 getBaseAndScale(base, scale, acls, CHECK_0); 789 return field_offset_from_byte_offset(base); 790 UNSAFE_END 791 792 793 UNSAFE_ENTRY(jint, Unsafe_ArrayIndexScale(JNIEnv *env, jobject unsafe, jclass acls)) 794 UnsafeWrapper("Unsafe_ArrayIndexScale"); 795 int base = 0, scale = 0; 796 getBaseAndScale(base, scale, acls, CHECK_0); 797 // This VM packs both fields and array elements down to the byte. 798 // But watch out: If this changes, so that array references for 799 // a given primitive type (say, T_BOOLEAN) use different memory units 800 // than fields, this method MUST return zero for such arrays. 801 // For example, the VM used to store sub-word sized fields in full 802 // words in the object layout, so that accessors like getByte(Object,int) 803 // did not really do what one might expect for arrays. Therefore, 804 // this function used to report a zero scale factor, so that the user 805 // would know not to attempt to access sub-word array elements. 806 // // Code for unpacked fields: 807 // if (scale < wordSize) return 0; 808 809 // The following allows for a pretty general fieldOffset cookie scheme, 810 // but requires it to be linear in byte offset. 811 return field_offset_from_byte_offset(scale) - field_offset_from_byte_offset(0); 812 UNSAFE_END 813 814 815 static inline void throw_new(JNIEnv *env, const char *ename) { 816 char buf[100]; 817 jio_snprintf(buf, 100, "%s%s", "java/lang/", ename); 818 jclass cls = env->FindClass(buf); 819 if (env->ExceptionCheck()) { 820 env->ExceptionClear(); 821 tty->print_cr("Unsafe: cannot throw %s because FindClass has failed", buf); 822 return; 823 } 824 char* msg = NULL; 825 env->ThrowNew(cls, msg); 826 } 827 828 static jclass Unsafe_DefineClass_impl(JNIEnv *env, jstring name, jbyteArray data, int offset, int length, jobject loader, jobject pd) { 829 { 830 // Code lifted from JDK 1.3 ClassLoader.c 831 832 jbyte *body; 833 char *utfName; 834 jclass result = 0; 835 char buf[128]; 836 837 if (UsePerfData) { 838 ClassLoader::unsafe_defineClassCallCounter()->inc(); 839 } 840 841 if (data == NULL) { 842 throw_new(env, "NullPointerException"); 843 return 0; 844 } 845 846 /* Work around 4153825. malloc crashes on Solaris when passed a 847 * negative size. 848 */ 849 if (length < 0) { 850 throw_new(env, "ArrayIndexOutOfBoundsException"); 851 return 0; 852 } 853 854 body = NEW_C_HEAP_ARRAY(jbyte, length, mtInternal); 855 856 if (body == 0) { 857 throw_new(env, "OutOfMemoryError"); 858 return 0; 859 } 860 861 env->GetByteArrayRegion(data, offset, length, body); 862 863 if (env->ExceptionOccurred()) 864 goto free_body; 865 866 if (name != NULL) { 867 uint len = env->GetStringUTFLength(name); 868 int unicode_len = env->GetStringLength(name); 869 if (len >= sizeof(buf)) { 870 utfName = NEW_C_HEAP_ARRAY(char, len + 1, mtInternal); 871 if (utfName == NULL) { 872 throw_new(env, "OutOfMemoryError"); 873 goto free_body; 874 } 875 } else { 876 utfName = buf; 877 } 878 env->GetStringUTFRegion(name, 0, unicode_len, utfName); 879 //VerifyFixClassname(utfName); 880 for (uint i = 0; i < len; i++) { 881 if (utfName[i] == '.') utfName[i] = '/'; 882 } 883 } else { 884 utfName = NULL; 885 } 886 887 result = JVM_DefineClass(env, utfName, loader, body, length, pd); 888 889 if (utfName && utfName != buf) 890 FREE_C_HEAP_ARRAY(char, utfName); 891 892 free_body: 893 FREE_C_HEAP_ARRAY(jbyte, body); 894 return result; 895 } 896 } 897 898 899 UNSAFE_ENTRY(jclass, Unsafe_DefineClass(JNIEnv *env, jobject unsafe, jstring name, jbyteArray data, int offset, int length, jobject loader, jobject pd)) 900 UnsafeWrapper("Unsafe_DefineClass"); 901 { 902 ThreadToNativeFromVM ttnfv(thread); 903 return Unsafe_DefineClass_impl(env, name, data, offset, length, loader, pd); 904 } 905 UNSAFE_END 906 907 908 // define a class but do not make it known to the class loader or system dictionary 909 // - host_class: supplies context for linkage, access control, protection domain, and class loader 910 // - data: bytes of a class file, a raw memory address (length gives the number of bytes) 911 // - cp_patches: where non-null entries exist, they replace corresponding CP entries in data 912 913 // When you load an anonymous class U, it works as if you changed its name just before loading, 914 // to a name that you will never use again. Since the name is lost, no other class can directly 915 // link to any member of U. Just after U is loaded, the only way to use it is reflectively, 916 // through java.lang.Class methods like Class.newInstance. 917 918 // Access checks for linkage sites within U continue to follow the same rules as for named classes. 919 // The package of an anonymous class is given by the package qualifier on the name under which it was loaded. 920 // An anonymous class also has special privileges to access any member of its host class. 921 // This is the main reason why this loading operation is unsafe. The purpose of this is to 922 // allow language implementations to simulate "open classes"; a host class in effect gets 923 // new code when an anonymous class is loaded alongside it. A less convenient but more 924 // standard way to do this is with reflection, which can also be set to ignore access 925 // restrictions. 926 927 // Access into an anonymous class is possible only through reflection. Therefore, there 928 // are no special access rules for calling into an anonymous class. The relaxed access 929 // rule for the host class is applied in the opposite direction: A host class reflectively 930 // access one of its anonymous classes. 931 932 // If you load the same bytecodes twice, you get two different classes. You can reload 933 // the same bytecodes with or without varying CP patches. 934 935 // By using the CP patching array, you can have a new anonymous class U2 refer to an older one U1. 936 // The bytecodes for U2 should refer to U1 by a symbolic name (doesn't matter what the name is). 937 // The CONSTANT_Class entry for that name can be patched to refer directly to U1. 938 939 // This allows, for example, U2 to use U1 as a superclass or super-interface, or as 940 // an outer class (so that U2 is an anonymous inner class of anonymous U1). 941 // It is not possible for a named class, or an older anonymous class, to refer by 942 // name (via its CP) to a newer anonymous class. 943 944 // CP patching may also be used to modify (i.e., hack) the names of methods, classes, 945 // or type descriptors used in the loaded anonymous class. 946 947 // Finally, CP patching may be used to introduce "live" objects into the constant pool, 948 // instead of "dead" strings. A compiled statement like println((Object)"hello") can 949 // be changed to println(greeting), where greeting is an arbitrary object created before 950 // the anonymous class is loaded. This is useful in dynamic languages, in which 951 // various kinds of metaobjects must be introduced as constants into bytecode. 952 // Note the cast (Object), which tells the verifier to expect an arbitrary object, 953 // not just a literal string. For such ldc instructions, the verifier uses the 954 // type Object instead of String, if the loaded constant is not in fact a String. 955 956 static instanceKlassHandle 957 Unsafe_DefineAnonymousClass_impl(JNIEnv *env, 958 jclass host_class, jbyteArray data, jobjectArray cp_patches_jh, 959 HeapWord* *temp_alloc, 960 TRAPS) { 961 962 if (UsePerfData) { 963 ClassLoader::unsafe_defineClassCallCounter()->inc(); 964 } 965 966 if (data == NULL) { 967 THROW_0(vmSymbols::java_lang_NullPointerException()); 968 } 969 970 jint length = typeArrayOop(JNIHandles::resolve_non_null(data))->length(); 971 jint word_length = (length + sizeof(HeapWord)-1) / sizeof(HeapWord); 972 HeapWord* body = NEW_C_HEAP_ARRAY(HeapWord, word_length, mtInternal); 973 if (body == NULL) { 974 THROW_0(vmSymbols::java_lang_OutOfMemoryError()); 975 } 976 977 // caller responsible to free it: 978 (*temp_alloc) = body; 979 980 { 981 jbyte* array_base = typeArrayOop(JNIHandles::resolve_non_null(data))->byte_at_addr(0); 982 Copy::conjoint_words((HeapWord*) array_base, body, word_length); 983 } 984 985 u1* class_bytes = (u1*) body; 986 int class_bytes_length = (int) length; 987 if (class_bytes_length < 0) class_bytes_length = 0; 988 if (class_bytes == NULL 989 || host_class == NULL 990 || length != class_bytes_length) 991 THROW_0(vmSymbols::java_lang_IllegalArgumentException()); 992 993 objArrayHandle cp_patches_h; 994 if (cp_patches_jh != NULL) { 995 oop p = JNIHandles::resolve_non_null(cp_patches_jh); 996 if (!p->is_objArray()) 997 THROW_0(vmSymbols::java_lang_IllegalArgumentException()); 998 cp_patches_h = objArrayHandle(THREAD, (objArrayOop)p); 999 } 1000 1001 const Klass* host_klass = java_lang_Class::as_Klass(JNIHandles::resolve_non_null(host_class)); 1002 assert(host_klass != NULL, "invariant"); 1003 1004 const char* host_source = host_klass->external_name(); 1005 Handle host_loader(THREAD, host_klass->class_loader()); 1006 Handle host_domain(THREAD, host_klass->protection_domain()); 1007 1008 GrowableArray<Handle>* cp_patches = NULL; 1009 if (cp_patches_h.not_null()) { 1010 int alen = cp_patches_h->length(); 1011 for (int i = alen-1; i >= 0; i--) { 1012 oop p = cp_patches_h->obj_at(i); 1013 if (p != NULL) { 1014 Handle patch(THREAD, p); 1015 if (cp_patches == NULL) 1016 cp_patches = new GrowableArray<Handle>(i+1, i+1, Handle()); 1017 cp_patches->at_put(i, patch); 1018 } 1019 } 1020 } 1021 1022 ClassFileStream st(class_bytes, 1023 class_bytes_length, 1024 host_source, 1025 ClassFileStream::verify); 1026 1027 instanceKlassHandle anon_klass; 1028 { 1029 Symbol* no_class_name = NULL; 1030 Klass* anonk = SystemDictionary::parse_stream(no_class_name, 1031 host_loader, 1032 host_domain, 1033 &st, 1034 host_klass, 1035 cp_patches, 1036 CHECK_NULL); 1037 if (anonk == NULL) return NULL; 1038 anon_klass = instanceKlassHandle(THREAD, anonk); 1039 } 1040 1041 return anon_klass; 1042 } 1043 1044 UNSAFE_ENTRY(jclass, Unsafe_DefineAnonymousClass(JNIEnv *env, jobject unsafe, jclass host_class, jbyteArray data, jobjectArray cp_patches_jh)) 1045 { 1046 instanceKlassHandle anon_klass; 1047 jobject res_jh = NULL; 1048 1049 UnsafeWrapper("Unsafe_DefineAnonymousClass"); 1050 ResourceMark rm(THREAD); 1051 1052 HeapWord* temp_alloc = NULL; 1053 1054 anon_klass = Unsafe_DefineAnonymousClass_impl(env, host_class, data, 1055 cp_patches_jh, 1056 &temp_alloc, THREAD); 1057 if (anon_klass() != NULL) 1058 res_jh = JNIHandles::make_local(env, anon_klass->java_mirror()); 1059 1060 // try/finally clause: 1061 if (temp_alloc != NULL) { 1062 FREE_C_HEAP_ARRAY(HeapWord, temp_alloc); 1063 } 1064 1065 // The anonymous class loader data has been artificially been kept alive to 1066 // this point. The mirror and any instances of this class have to keep 1067 // it alive afterwards. 1068 if (anon_klass() != NULL) { 1069 anon_klass->class_loader_data()->set_keep_alive(false); 1070 } 1071 1072 // let caller initialize it as needed... 1073 1074 return (jclass) res_jh; 1075 } 1076 UNSAFE_END 1077 1078 1079 1080 UNSAFE_ENTRY(void, Unsafe_ThrowException(JNIEnv *env, jobject unsafe, jthrowable thr)) 1081 UnsafeWrapper("Unsafe_ThrowException"); 1082 { 1083 ThreadToNativeFromVM ttnfv(thread); 1084 env->Throw(thr); 1085 } 1086 UNSAFE_END 1087 1088 // JSR166 ------------------------------------------------------------------ 1089 1090 UNSAFE_ENTRY(jboolean, Unsafe_CompareAndSwapObject(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jobject e_h, jobject x_h)) 1091 UnsafeWrapper("Unsafe_CompareAndSwapObject"); 1092 oop x = JNIHandles::resolve(x_h); 1093 oop e = JNIHandles::resolve(e_h); 1094 oop p = JNIHandles::resolve(obj); 1095 HeapWord* addr = (HeapWord *)index_oop_from_field_offset_long(p, offset); 1096 oop res = oopDesc::atomic_compare_exchange_oop(x, addr, e, true); 1097 jboolean success = (res == e); 1098 if (success) 1099 update_barrier_set((void*)addr, x); 1100 return success; 1101 UNSAFE_END 1102 1103 UNSAFE_ENTRY(jboolean, Unsafe_CompareAndSwapInt(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jint e, jint x)) 1104 UnsafeWrapper("Unsafe_CompareAndSwapInt"); 1105 oop p = JNIHandles::resolve(obj); 1106 jint* addr = (jint *) index_oop_from_field_offset_long(p, offset); 1107 return (jint)(Atomic::cmpxchg(x, addr, e)) == e; 1108 UNSAFE_END 1109 1110 UNSAFE_ENTRY(jboolean, Unsafe_CompareAndSwapLong(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jlong e, jlong x)) 1111 UnsafeWrapper("Unsafe_CompareAndSwapLong"); 1112 Handle p (THREAD, JNIHandles::resolve(obj)); 1113 jlong* addr = (jlong*)(index_oop_from_field_offset_long(p(), offset)); 1114 #ifdef SUPPORTS_NATIVE_CX8 1115 return (jlong)(Atomic::cmpxchg(x, addr, e)) == e; 1116 #else 1117 if (VM_Version::supports_cx8()) 1118 return (jlong)(Atomic::cmpxchg(x, addr, e)) == e; 1119 else { 1120 jboolean success = false; 1121 MutexLockerEx mu(UnsafeJlong_lock, Mutex::_no_safepoint_check_flag); 1122 jlong val = Atomic::load(addr); 1123 if (val == e) { Atomic::store(x, addr); success = true; } 1124 return success; 1125 } 1126 #endif 1127 UNSAFE_END 1128 1129 UNSAFE_ENTRY(void, Unsafe_Park(JNIEnv *env, jobject unsafe, jboolean isAbsolute, jlong time)) 1130 UnsafeWrapper("Unsafe_Park"); 1131 EventThreadPark event; 1132 HOTSPOT_THREAD_PARK_BEGIN((uintptr_t) thread->parker(), (int) isAbsolute, time); 1133 1134 JavaThreadParkedState jtps(thread, time != 0); 1135 thread->parker()->park(isAbsolute != 0, time); 1136 1137 HOTSPOT_THREAD_PARK_END((uintptr_t) thread->parker()); 1138 if (event.should_commit()) { 1139 oop obj = thread->current_park_blocker(); 1140 event.set_klass((obj != NULL) ? obj->klass() : NULL); 1141 event.set_timeout(time); 1142 event.set_address((obj != NULL) ? (TYPE_ADDRESS) cast_from_oop<uintptr_t>(obj) : 0); 1143 event.commit(); 1144 } 1145 UNSAFE_END 1146 1147 UNSAFE_ENTRY(void, Unsafe_Unpark(JNIEnv *env, jobject unsafe, jobject jthread)) 1148 UnsafeWrapper("Unsafe_Unpark"); 1149 Parker* p = NULL; 1150 if (jthread != NULL) { 1151 oop java_thread = JNIHandles::resolve_non_null(jthread); 1152 if (java_thread != NULL) { 1153 jlong lp = java_lang_Thread::park_event(java_thread); 1154 if (lp != 0) { 1155 // This cast is OK even though the jlong might have been read 1156 // non-atomically on 32bit systems, since there, one word will 1157 // always be zero anyway and the value set is always the same 1158 p = (Parker*)addr_from_java(lp); 1159 } else { 1160 // Grab lock if apparently null or using older version of library 1161 MutexLocker mu(Threads_lock); 1162 java_thread = JNIHandles::resolve_non_null(jthread); 1163 if (java_thread != NULL) { 1164 JavaThread* thr = java_lang_Thread::thread(java_thread); 1165 if (thr != NULL) { 1166 p = thr->parker(); 1167 if (p != NULL) { // Bind to Java thread for next time. 1168 java_lang_Thread::set_park_event(java_thread, addr_to_java(p)); 1169 } 1170 } 1171 } 1172 } 1173 } 1174 } 1175 if (p != NULL) { 1176 HOTSPOT_THREAD_UNPARK((uintptr_t) p); 1177 p->unpark(); 1178 } 1179 UNSAFE_END 1180 1181 UNSAFE_ENTRY(jint, Unsafe_Loadavg(JNIEnv *env, jobject unsafe, jdoubleArray loadavg, jint nelem)) 1182 UnsafeWrapper("Unsafe_Loadavg"); 1183 const int max_nelem = 3; 1184 double la[max_nelem]; 1185 jint ret; 1186 1187 typeArrayOop a = typeArrayOop(JNIHandles::resolve_non_null(loadavg)); 1188 assert(a->is_typeArray(), "must be type array"); 1189 1190 if (nelem < 0 || nelem > max_nelem || a->length() < nelem) { 1191 ThreadToNativeFromVM ttnfv(thread); 1192 throw_new(env, "ArrayIndexOutOfBoundsException"); 1193 return -1; 1194 } 1195 1196 ret = os::loadavg(la, nelem); 1197 if (ret == -1) return -1; 1198 1199 // if successful, ret is the number of samples actually retrieved. 1200 assert(ret >= 0 && ret <= max_nelem, "Unexpected loadavg return value"); 1201 switch(ret) { 1202 case 3: a->double_at_put(2, (jdouble)la[2]); // fall through 1203 case 2: a->double_at_put(1, (jdouble)la[1]); // fall through 1204 case 1: a->double_at_put(0, (jdouble)la[0]); break; 1205 } 1206 return ret; 1207 UNSAFE_END 1208 1209 1210 /// JVM_RegisterUnsafeMethods 1211 1212 #define ADR "J" 1213 1214 #define LANG "Ljava/lang/" 1215 1216 #define OBJ LANG "Object;" 1217 #define CLS LANG "Class;" 1218 #define FLD LANG "reflect/Field;" 1219 #define THR LANG "Throwable;" 1220 1221 #define DC_Args LANG "String;[BII" LANG "ClassLoader;" "Ljava/security/ProtectionDomain;" 1222 #define DAC_Args CLS "[B[" OBJ 1223 1224 #define CC (char*) /*cast a literal from (const char*)*/ 1225 #define FN_PTR(f) CAST_FROM_FN_PTR(void*, &f) 1226 1227 #define DECLARE_GETPUTOOP(Boolean, Z) \ 1228 {CC "get" #Boolean, CC "(" OBJ "J)" #Z, FN_PTR(Unsafe_Get##Boolean)}, \ 1229 {CC "put" #Boolean, CC "(" OBJ "J" #Z ")V", FN_PTR(Unsafe_Set##Boolean)}, \ 1230 {CC "get" #Boolean "Volatile", CC "(" OBJ "J)" #Z, FN_PTR(Unsafe_Get##Boolean##Volatile)}, \ 1231 {CC "put" #Boolean "Volatile", CC "(" OBJ "J" #Z ")V", FN_PTR(Unsafe_Set##Boolean##Volatile)} 1232 1233 1234 #define DECLARE_GETPUTNATIVE(Byte, B) \ 1235 {CC "get" #Byte, CC "(" ADR ")" #B, FN_PTR(Unsafe_GetNative##Byte)}, \ 1236 {CC "put" #Byte, CC "(" ADR#B ")V", FN_PTR(Unsafe_SetNative##Byte)} 1237 1238 1239 static JNINativeMethod sun_misc_Unsafe_methods[] = { 1240 {CC "getObject", CC "(" OBJ "J)" OBJ "", FN_PTR(Unsafe_GetObject)}, 1241 {CC "putObject", CC "(" OBJ "J" OBJ ")V", FN_PTR(Unsafe_SetObject)}, 1242 {CC "getObjectVolatile",CC "(" OBJ "J)" OBJ "", FN_PTR(Unsafe_GetObjectVolatile)}, 1243 {CC "putObjectVolatile",CC "(" OBJ "J" OBJ ")V", FN_PTR(Unsafe_SetObjectVolatile)}, 1244 1245 {CC "getUncompressedObject", CC "(" ADR ")" OBJ, FN_PTR(Unsafe_GetUncompressedObject)}, 1246 {CC "getJavaMirror", CC "(" ADR ")" CLS, FN_PTR(Unsafe_GetJavaMirror)}, 1247 {CC "getKlassPointer", CC "(" OBJ ")" ADR, FN_PTR(Unsafe_GetKlassPointer)}, 1248 1249 DECLARE_GETPUTOOP(Boolean, Z), 1250 DECLARE_GETPUTOOP(Byte, B), 1251 DECLARE_GETPUTOOP(Short, S), 1252 DECLARE_GETPUTOOP(Char, C), 1253 DECLARE_GETPUTOOP(Int, I), 1254 DECLARE_GETPUTOOP(Long, J), 1255 DECLARE_GETPUTOOP(Float, F), 1256 DECLARE_GETPUTOOP(Double, D), 1257 1258 DECLARE_GETPUTNATIVE(Byte, B), 1259 DECLARE_GETPUTNATIVE(Short, S), 1260 DECLARE_GETPUTNATIVE(Char, C), 1261 DECLARE_GETPUTNATIVE(Int, I), 1262 DECLARE_GETPUTNATIVE(Long, J), 1263 DECLARE_GETPUTNATIVE(Float, F), 1264 DECLARE_GETPUTNATIVE(Double, D), 1265 1266 {CC "getAddress", CC "(" ADR ")" ADR, FN_PTR(Unsafe_GetNativeAddress)}, 1267 {CC "putAddress", CC "(" ADR "" ADR ")V", FN_PTR(Unsafe_SetNativeAddress)}, 1268 1269 {CC "allocateMemory", CC "(J)" ADR, FN_PTR(Unsafe_AllocateMemory)}, 1270 {CC "reallocateMemory", CC "(" ADR "J)" ADR, FN_PTR(Unsafe_ReallocateMemory)}, 1271 {CC "freeMemory", CC "(" ADR ")V", FN_PTR(Unsafe_FreeMemory)}, 1272 1273 {CC "objectFieldOffset", CC "(" FLD ")J", FN_PTR(Unsafe_ObjectFieldOffset)}, 1274 {CC "staticFieldOffset", CC "(" FLD ")J", FN_PTR(Unsafe_StaticFieldOffset)}, 1275 {CC "staticFieldBase", CC "(" FLD ")" OBJ, FN_PTR(Unsafe_StaticFieldBaseFromField)}, 1276 {CC "ensureClassInitialized",CC "(" CLS ")V", FN_PTR(Unsafe_EnsureClassInitialized)}, 1277 {CC "arrayBaseOffset", CC "(" CLS ")I", FN_PTR(Unsafe_ArrayBaseOffset)}, 1278 {CC "arrayIndexScale", CC "(" CLS ")I", FN_PTR(Unsafe_ArrayIndexScale)}, 1279 {CC "addressSize", CC "()I", FN_PTR(Unsafe_AddressSize)}, 1280 {CC "pageSize", CC "()I", FN_PTR(Unsafe_PageSize)}, 1281 1282 {CC "defineClass", CC "(" DC_Args ")" CLS, FN_PTR(Unsafe_DefineClass)}, 1283 {CC "allocateInstance", CC "(" CLS ")" OBJ, FN_PTR(Unsafe_AllocateInstance)}, 1284 {CC "throwException", CC "(" THR ")V", FN_PTR(Unsafe_ThrowException)}, 1285 {CC "compareAndSwapObject", CC "(" OBJ "J" OBJ "" OBJ ")Z", FN_PTR(Unsafe_CompareAndSwapObject)}, 1286 {CC "compareAndSwapInt", CC "(" OBJ "J""I""I"")Z", FN_PTR(Unsafe_CompareAndSwapInt)}, 1287 {CC "compareAndSwapLong", CC "(" OBJ "J""J""J"")Z", FN_PTR(Unsafe_CompareAndSwapLong)}, 1288 {CC "putOrderedObject", CC "(" OBJ "J" OBJ ")V", FN_PTR(Unsafe_SetOrderedObject)}, 1289 {CC "putOrderedInt", CC "(" OBJ "JI)V", FN_PTR(Unsafe_SetOrderedInt)}, 1290 {CC "putOrderedLong", CC "(" OBJ "JJ)V", FN_PTR(Unsafe_SetOrderedLong)}, 1291 {CC "park", CC "(ZJ)V", FN_PTR(Unsafe_Park)}, 1292 {CC "unpark", CC "(" OBJ ")V", FN_PTR(Unsafe_Unpark)}, 1293 1294 {CC "getLoadAverage", CC "([DI)I", FN_PTR(Unsafe_Loadavg)}, 1295 1296 {CC "copyMemory", CC "(" OBJ "J" OBJ "JJ)V", FN_PTR(Unsafe_CopyMemory)}, 1297 {CC "setMemory", CC "(" OBJ "JJB)V", FN_PTR(Unsafe_SetMemory)}, 1298 1299 {CC "defineAnonymousClass", CC "(" DAC_Args ")" CLS, FN_PTR(Unsafe_DefineAnonymousClass)}, 1300 1301 {CC "shouldBeInitialized",CC "(" CLS ")Z", FN_PTR(Unsafe_ShouldBeInitialized)}, 1302 1303 {CC "loadFence", CC "()V", FN_PTR(Unsafe_LoadFence)}, 1304 {CC "storeFence", CC "()V", FN_PTR(Unsafe_StoreFence)}, 1305 {CC "fullFence", CC "()V", FN_PTR(Unsafe_FullFence)}, 1306 }; 1307 1308 static JNINativeMethod jdk_internal_misc_Unsafe_methods[] = { 1309 {CC "getObject", CC "(" OBJ "J)" OBJ "", FN_PTR(Unsafe_GetObject)}, 1310 {CC "putObject", CC "(" OBJ "J" OBJ ")V", FN_PTR(Unsafe_SetObject)}, 1311 {CC "getObjectVolatile",CC "(" OBJ "J)" OBJ "", FN_PTR(Unsafe_GetObjectVolatile)}, 1312 {CC "putObjectVolatile",CC "(" OBJ "J" OBJ ")V", FN_PTR(Unsafe_SetObjectVolatile)}, 1313 1314 {CC "getUncompressedObject", CC "(" ADR ")" OBJ, FN_PTR(Unsafe_GetUncompressedObject)}, 1315 {CC "getJavaMirror", CC "(" ADR ")" CLS, FN_PTR(Unsafe_GetJavaMirror)}, 1316 {CC "getKlassPointer", CC "(" OBJ ")" ADR, FN_PTR(Unsafe_GetKlassPointer)}, 1317 1318 DECLARE_GETPUTOOP(Boolean, Z), 1319 DECLARE_GETPUTOOP(Byte, B), 1320 DECLARE_GETPUTOOP(Short, S), 1321 DECLARE_GETPUTOOP(Char, C), 1322 DECLARE_GETPUTOOP(Int, I), 1323 DECLARE_GETPUTOOP(Long, J), 1324 DECLARE_GETPUTOOP(Float, F), 1325 DECLARE_GETPUTOOP(Double, D), 1326 1327 DECLARE_GETPUTNATIVE(Byte, B), 1328 DECLARE_GETPUTNATIVE(Short, S), 1329 DECLARE_GETPUTNATIVE(Char, C), 1330 DECLARE_GETPUTNATIVE(Int, I), 1331 DECLARE_GETPUTNATIVE(Long, J), 1332 DECLARE_GETPUTNATIVE(Float, F), 1333 DECLARE_GETPUTNATIVE(Double, D), 1334 1335 {CC "getAddress", CC "(" ADR ")" ADR, FN_PTR(Unsafe_GetNativeAddress)}, 1336 {CC "putAddress", CC "(" ADR "" ADR ")V", FN_PTR(Unsafe_SetNativeAddress)}, 1337 1338 {CC "allocateMemory", CC "(J)" ADR, FN_PTR(Unsafe_AllocateMemory)}, 1339 {CC "reallocateMemory", CC "(" ADR "J)" ADR, FN_PTR(Unsafe_ReallocateMemory)}, 1340 {CC "freeMemory", CC "(" ADR ")V", FN_PTR(Unsafe_FreeMemory)}, 1341 1342 {CC "objectFieldOffset", CC "(" FLD ")J", FN_PTR(Unsafe_ObjectFieldOffset)}, 1343 {CC "staticFieldOffset", CC "(" FLD ")J", FN_PTR(Unsafe_StaticFieldOffset)}, 1344 {CC "staticFieldBase", CC "(" FLD ")" OBJ, FN_PTR(Unsafe_StaticFieldBaseFromField)}, 1345 {CC "ensureClassInitialized",CC "(" CLS ")V", FN_PTR(Unsafe_EnsureClassInitialized)}, 1346 {CC "arrayBaseOffset", CC "(" CLS ")I", FN_PTR(Unsafe_ArrayBaseOffset)}, 1347 {CC "arrayIndexScale", CC "(" CLS ")I", FN_PTR(Unsafe_ArrayIndexScale)}, 1348 {CC "addressSize", CC "()I", FN_PTR(Unsafe_AddressSize)}, 1349 {CC "pageSize", CC "()I", FN_PTR(Unsafe_PageSize)}, 1350 1351 {CC "defineClass", CC "(" DC_Args ")" CLS, FN_PTR(Unsafe_DefineClass)}, 1352 {CC "allocateInstance", CC "(" CLS ")" OBJ, FN_PTR(Unsafe_AllocateInstance)}, 1353 {CC "throwException", CC "(" THR ")V", FN_PTR(Unsafe_ThrowException)}, 1354 {CC "compareAndSwapObject", CC "(" OBJ "J" OBJ "" OBJ ")Z", FN_PTR(Unsafe_CompareAndSwapObject)}, 1355 {CC "compareAndSwapInt", CC "(" OBJ "J""I""I"")Z", FN_PTR(Unsafe_CompareAndSwapInt)}, 1356 {CC "compareAndSwapLong", CC "(" OBJ "J""J""J"")Z", FN_PTR(Unsafe_CompareAndSwapLong)}, 1357 {CC "putOrderedObject", CC "(" OBJ "J" OBJ ")V", FN_PTR(Unsafe_SetOrderedObject)}, 1358 {CC "putOrderedInt", CC "(" OBJ "JI)V", FN_PTR(Unsafe_SetOrderedInt)}, 1359 {CC "putOrderedLong", CC "(" OBJ "JJ)V", FN_PTR(Unsafe_SetOrderedLong)}, 1360 {CC "park", CC "(ZJ)V", FN_PTR(Unsafe_Park)}, 1361 {CC "unpark", CC "(" OBJ ")V", FN_PTR(Unsafe_Unpark)}, 1362 1363 {CC "getLoadAverage", CC "([DI)I", FN_PTR(Unsafe_Loadavg)}, 1364 1365 {CC "copyMemory", CC "(" OBJ "J" OBJ "JJ)V", FN_PTR(Unsafe_CopyMemory)}, 1366 {CC "setMemory", CC "(" OBJ "JJB)V", FN_PTR(Unsafe_SetMemory)}, 1367 1368 {CC "defineAnonymousClass", CC "(" DAC_Args ")" CLS, FN_PTR(Unsafe_DefineAnonymousClass)}, 1369 1370 {CC "shouldBeInitialized",CC "(" CLS ")Z", FN_PTR(Unsafe_ShouldBeInitialized)}, 1371 1372 {CC "loadFence", CC "()V", FN_PTR(Unsafe_LoadFence)}, 1373 {CC "storeFence", CC "()V", FN_PTR(Unsafe_StoreFence)}, 1374 {CC "fullFence", CC "()V", FN_PTR(Unsafe_FullFence)}, 1375 1376 {CC "isBigEndian0", CC "()Z", FN_PTR(Unsafe_isBigEndian0)}, 1377 {CC "unalignedAccess0", CC "()Z", FN_PTR(Unsafe_unalignedAccess0)} 1378 }; 1379 1380 #undef CC 1381 #undef FN_PTR 1382 1383 #undef ADR 1384 #undef LANG 1385 #undef OBJ 1386 #undef CLS 1387 #undef FLD 1388 #undef THR 1389 #undef DC_Args 1390 #undef DAC_Args 1391 1392 #undef DECLARE_GETPUTOOP 1393 #undef DECLARE_GETPUTNATIVE 1394 1395 1396 // These two functions are exported, used by NativeLookup. 1397 // The Unsafe_xxx functions above are called only from the interpreter. 1398 // The optimizer looks at names and signatures to recognize 1399 // individual functions. 1400 1401 JVM_ENTRY(void, JVM_RegisterSunMiscUnsafeMethods(JNIEnv *env, jclass unsafeclass)) 1402 UnsafeWrapper("JVM_RegisterSunMiscUnsafeMethods"); 1403 { 1404 ThreadToNativeFromVM ttnfv(thread); 1405 1406 int ok = env->RegisterNatives(unsafeclass, sun_misc_Unsafe_methods, sizeof(sun_misc_Unsafe_methods)/sizeof(JNINativeMethod)); 1407 guarantee(ok == 0, "register sun.misc.Unsafe natives"); 1408 } 1409 JVM_END 1410 1411 JVM_ENTRY(void, JVM_RegisterJDKInternalMiscUnsafeMethods(JNIEnv *env, jclass unsafeclass)) 1412 UnsafeWrapper("JVM_RegisterJDKInternalMiscUnsafeMethods"); 1413 { 1414 ThreadToNativeFromVM ttnfv(thread); 1415 1416 int ok = env->RegisterNatives(unsafeclass, jdk_internal_misc_Unsafe_methods, sizeof(jdk_internal_misc_Unsafe_methods)/sizeof(JNINativeMethod)); 1417 guarantee(ok == 0, "register jdk.internal.misc.Unsafe natives"); 1418 } 1419 JVM_END