1 /* 2 * Copyright (c) 2012, 2013, 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 27 #include "memory/universe.hpp" 28 #include "oops/oop.inline.hpp" 29 30 #include "classfile/symbolTable.hpp" 31 #include "classfile/classLoaderData.hpp" 32 33 #include "prims/whitebox.hpp" 34 #include "prims/wbtestmethods/parserTests.hpp" 35 36 #include "runtime/arguments.hpp" 37 #include "runtime/interfaceSupport.hpp" 38 #include "runtime/os.hpp" 39 #include "utilities/debug.hpp" 40 #include "utilities/macros.hpp" 41 #include "utilities/exceptions.hpp" 42 43 #if INCLUDE_ALL_GCS 44 #include "gc_implementation/g1/concurrentMark.hpp" 45 #include "gc_implementation/g1/g1CollectedHeap.inline.hpp" 46 #include "gc_implementation/g1/heapRegionRemSet.hpp" 47 #endif // INCLUDE_ALL_GCS 48 49 #ifdef INCLUDE_NMT 50 #include "services/memTracker.hpp" 51 #endif // INCLUDE_NMT 52 53 #include "compiler/compileBroker.hpp" 54 #include "runtime/compilationPolicy.hpp" 55 56 bool WhiteBox::_used = false; 57 58 WB_ENTRY(jlong, WB_GetObjectAddress(JNIEnv* env, jobject o, jobject obj)) 59 return (jlong)(void*)JNIHandles::resolve(obj); 60 WB_END 61 62 WB_ENTRY(jint, WB_GetHeapOopSize(JNIEnv* env, jobject o)) 63 return heapOopSize; 64 WB_END 65 66 67 class WBIsKlassAliveClosure : public KlassClosure { 68 Symbol* _name; 69 bool _found; 70 public: 71 WBIsKlassAliveClosure(Symbol* name) : _name(name), _found(false) {} 72 73 void do_klass(Klass* k) { 74 if (_found) return; 75 Symbol* ksym = k->name(); 76 if (ksym->fast_compare(_name) == 0) { 77 _found = true; 78 } 79 } 80 81 bool found() const { 82 return _found; 83 } 84 }; 85 86 WB_ENTRY(jboolean, WB_IsClassAlive(JNIEnv* env, jobject target, jstring name)) 87 Handle h_name = JNIHandles::resolve(name); 88 if (h_name.is_null()) return false; 89 Symbol* sym = java_lang_String::as_symbol(h_name, CHECK_false); 90 TempNewSymbol tsym(sym); // Make sure to decrement reference count on sym on return 91 92 WBIsKlassAliveClosure closure(sym); 93 ClassLoaderDataGraph::classes_do(&closure); 94 95 return closure.found(); 96 WB_END 97 98 WB_ENTRY(jlong, WB_GetCompressedOopsMaxHeapSize(JNIEnv* env, jobject o)) { 99 return (jlong)Arguments::max_heap_for_compressed_oops(); 100 } 101 WB_END 102 103 WB_ENTRY(void, WB_PrintHeapSizes(JNIEnv* env, jobject o)) { 104 CollectorPolicy * p = Universe::heap()->collector_policy(); 105 gclog_or_tty->print_cr("Minimum heap "SIZE_FORMAT" Initial heap " 106 SIZE_FORMAT" Maximum heap "SIZE_FORMAT" Min alignment "SIZE_FORMAT" Max alignment "SIZE_FORMAT, 107 p->min_heap_byte_size(), p->initial_heap_byte_size(), p->max_heap_byte_size(), 108 p->min_alignment(), p->max_alignment()); 109 } 110 WB_END 111 112 #if INCLUDE_ALL_GCS 113 WB_ENTRY(jboolean, WB_G1IsHumongous(JNIEnv* env, jobject o, jobject obj)) 114 G1CollectedHeap* g1 = G1CollectedHeap::heap(); 115 oop result = JNIHandles::resolve(obj); 116 const HeapRegion* hr = g1->heap_region_containing(result); 117 return hr->isHumongous(); 118 WB_END 119 120 WB_ENTRY(jlong, WB_G1NumFreeRegions(JNIEnv* env, jobject o)) 121 G1CollectedHeap* g1 = G1CollectedHeap::heap(); 122 size_t nr = g1->free_regions(); 123 return (jlong)nr; 124 WB_END 125 126 WB_ENTRY(jboolean, WB_G1InConcurrentMark(JNIEnv* env, jobject o)) 127 G1CollectedHeap* g1 = G1CollectedHeap::heap(); 128 ConcurrentMark* cm = g1->concurrent_mark(); 129 return cm->concurrent_marking_in_progress(); 130 WB_END 131 132 WB_ENTRY(jint, WB_G1RegionSize(JNIEnv* env, jobject o)) 133 return (jint)HeapRegion::GrainBytes; 134 WB_END 135 #endif // INCLUDE_ALL_GCS 136 137 #if INCLUDE_NMT 138 // Alloc memory using the test memory type so that we can use that to see if 139 // NMT picks it up correctly 140 WB_ENTRY(jlong, WB_NMTMalloc(JNIEnv* env, jobject o, jlong size)) 141 jlong addr = 0; 142 143 if (MemTracker::is_on() && !MemTracker::shutdown_in_progress()) { 144 addr = (jlong)(uintptr_t)os::malloc(size, mtTest); 145 } 146 147 return addr; 148 WB_END 149 150 // Free the memory allocated by NMTAllocTest 151 WB_ENTRY(void, WB_NMTFree(JNIEnv* env, jobject o, jlong mem)) 152 os::free((void*)(uintptr_t)mem, mtTest); 153 WB_END 154 155 WB_ENTRY(jlong, WB_NMTReserveMemory(JNIEnv* env, jobject o, jlong size)) 156 jlong addr = 0; 157 158 if (MemTracker::is_on() && !MemTracker::shutdown_in_progress()) { 159 addr = (jlong)(uintptr_t)os::reserve_memory(size); 160 MemTracker::record_virtual_memory_type((address)addr, mtTest); 161 } 162 163 return addr; 164 WB_END 165 166 167 WB_ENTRY(void, WB_NMTCommitMemory(JNIEnv* env, jobject o, jlong addr, jlong size)) 168 os::commit_memory((char *)(uintptr_t)addr, size, !ExecMem); 169 MemTracker::record_virtual_memory_type((address)(uintptr_t)addr, mtTest); 170 WB_END 171 172 WB_ENTRY(void, WB_NMTUncommitMemory(JNIEnv* env, jobject o, jlong addr, jlong size)) 173 os::uncommit_memory((char *)(uintptr_t)addr, size); 174 WB_END 175 176 WB_ENTRY(void, WB_NMTReleaseMemory(JNIEnv* env, jobject o, jlong addr, jlong size)) 177 os::release_memory((char *)(uintptr_t)addr, size); 178 WB_END 179 180 // Block until the current generation of NMT data to be merged, used to reliably test the NMT feature 181 WB_ENTRY(jboolean, WB_NMTWaitForDataMerge(JNIEnv* env)) 182 183 if (!MemTracker::is_on() || MemTracker::shutdown_in_progress()) { 184 return false; 185 } 186 187 return MemTracker::wbtest_wait_for_data_merge(); 188 WB_END 189 190 WB_ENTRY(jboolean, WB_NMTIsDetailSupported(JNIEnv* env)) 191 return MemTracker::tracking_level() == MemTracker::NMT_detail; 192 WB_END 193 194 #endif // INCLUDE_NMT 195 196 static jmethodID reflected_method_to_jmid(JavaThread* thread, JNIEnv* env, jobject method) { 197 assert(method != NULL, "method should not be null"); 198 ThreadToNativeFromVM ttn(thread); 199 return env->FromReflectedMethod(method); 200 } 201 202 WB_ENTRY(void, WB_DeoptimizeAll(JNIEnv* env, jobject o)) 203 MutexLockerEx mu(Compile_lock); 204 CodeCache::mark_all_nmethods_for_deoptimization(); 205 VM_Deoptimize op; 206 VMThread::execute(&op); 207 WB_END 208 209 WB_ENTRY(jint, WB_DeoptimizeMethod(JNIEnv* env, jobject o, jobject method, jboolean is_osr)) 210 jmethodID jmid = reflected_method_to_jmid(thread, env, method); 211 MutexLockerEx mu(Compile_lock); 212 methodHandle mh(THREAD, Method::checked_resolve_jmethod_id(jmid)); 213 int result = 0; 214 nmethod* code; 215 if (is_osr) { 216 int bci = InvocationEntryBci; 217 while ((code = mh->lookup_osr_nmethod_for(bci, CompLevel_none, false)) != NULL) { 218 code->mark_for_deoptimization(); 219 ++result; 220 bci = code->osr_entry_bci() + 1; 221 } 222 } else { 223 code = mh->code(); 224 } 225 if (code != NULL) { 226 code->mark_for_deoptimization(); 227 ++result; 228 } 229 result += CodeCache::mark_for_deoptimization(mh()); 230 if (result > 0) { 231 VM_Deoptimize op; 232 VMThread::execute(&op); 233 } 234 return result; 235 WB_END 236 237 WB_ENTRY(jboolean, WB_IsMethodCompiled(JNIEnv* env, jobject o, jobject method, jboolean is_osr)) 238 jmethodID jmid = reflected_method_to_jmid(thread, env, method); 239 MutexLockerEx mu(Compile_lock); 240 methodHandle mh(THREAD, Method::checked_resolve_jmethod_id(jmid)); 241 nmethod* code = is_osr ? mh->lookup_osr_nmethod_for(InvocationEntryBci, CompLevel_none, false) : mh->code(); 242 if (code == NULL) { 243 return JNI_FALSE; 244 } 245 return (code->is_alive() && !code->is_marked_for_deoptimization()); 246 WB_END 247 248 WB_ENTRY(jboolean, WB_IsMethodCompilable(JNIEnv* env, jobject o, jobject method, jint comp_level, jboolean is_osr)) 249 jmethodID jmid = reflected_method_to_jmid(thread, env, method); 250 MutexLockerEx mu(Compile_lock); 251 methodHandle mh(THREAD, Method::checked_resolve_jmethod_id(jmid)); 252 if (is_osr) { 253 return CompilationPolicy::can_be_osr_compiled(mh, comp_level); 254 } else { 255 return CompilationPolicy::can_be_compiled(mh, comp_level); 256 } 257 WB_END 258 259 WB_ENTRY(jboolean, WB_IsMethodQueuedForCompilation(JNIEnv* env, jobject o, jobject method)) 260 jmethodID jmid = reflected_method_to_jmid(thread, env, method); 261 MutexLockerEx mu(Compile_lock); 262 methodHandle mh(THREAD, Method::checked_resolve_jmethod_id(jmid)); 263 return mh->queued_for_compilation(); 264 WB_END 265 266 WB_ENTRY(jint, WB_GetMethodCompilationLevel(JNIEnv* env, jobject o, jobject method, jboolean is_osr)) 267 jmethodID jmid = reflected_method_to_jmid(thread, env, method); 268 methodHandle mh(THREAD, Method::checked_resolve_jmethod_id(jmid)); 269 nmethod* code = is_osr ? mh->lookup_osr_nmethod_for(InvocationEntryBci, CompLevel_none, false) : mh->code(); 270 return (code != NULL ? code->comp_level() : CompLevel_none); 271 WB_END 272 273 WB_ENTRY(void, WB_MakeMethodNotCompilable(JNIEnv* env, jobject o, jobject method, jint comp_level, jboolean is_osr)) 274 jmethodID jmid = reflected_method_to_jmid(thread, env, method); 275 methodHandle mh(THREAD, Method::checked_resolve_jmethod_id(jmid)); 276 if (is_osr) { 277 mh->set_not_osr_compilable(comp_level, true /* report */, "WhiteBox"); 278 } else { 279 mh->set_not_compilable(comp_level, true /* report */, "WhiteBox"); 280 } 281 WB_END 282 283 WB_ENTRY(jint, WB_GetMethodEntryBci(JNIEnv* env, jobject o, jobject method)) 284 jmethodID jmid = reflected_method_to_jmid(thread, env, method); 285 methodHandle mh(THREAD, Method::checked_resolve_jmethod_id(jmid)); 286 nmethod* code = mh->lookup_osr_nmethod_for(InvocationEntryBci, CompLevel_none, false); 287 return (code != NULL && code->is_osr_method() ? code->osr_entry_bci() : InvocationEntryBci); 288 WB_END 289 290 WB_ENTRY(jboolean, WB_TestSetDontInlineMethod(JNIEnv* env, jobject o, jobject method, jboolean value)) 291 jmethodID jmid = reflected_method_to_jmid(thread, env, method); 292 methodHandle mh(THREAD, Method::checked_resolve_jmethod_id(jmid)); 293 bool result = mh->dont_inline(); 294 mh->set_dont_inline(value == JNI_TRUE); 295 return result; 296 WB_END 297 298 WB_ENTRY(jint, WB_GetCompileQueueSize(JNIEnv* env, jobject o, jint comp_level)) 299 if (comp_level == CompLevel_any) { 300 return CompileBroker::queue_size(CompLevel_full_optimization) /* C2 */ + 301 CompileBroker::queue_size(CompLevel_full_profile) /* C1 */; 302 } else { 303 return CompileBroker::queue_size(comp_level); 304 } 305 WB_END 306 307 WB_ENTRY(jboolean, WB_TestSetForceInlineMethod(JNIEnv* env, jobject o, jobject method, jboolean value)) 308 jmethodID jmid = reflected_method_to_jmid(thread, env, method); 309 methodHandle mh(THREAD, Method::checked_resolve_jmethod_id(jmid)); 310 bool result = mh->force_inline(); 311 mh->set_force_inline(value == JNI_TRUE); 312 return result; 313 WB_END 314 315 WB_ENTRY(jboolean, WB_EnqueueMethodForCompilation(JNIEnv* env, jobject o, jobject method, jint comp_level, jint bci)) 316 jmethodID jmid = reflected_method_to_jmid(thread, env, method); 317 methodHandle mh(THREAD, Method::checked_resolve_jmethod_id(jmid)); 318 nmethod* nm = CompileBroker::compile_method(mh, bci, comp_level, mh, mh->invocation_count(), "WhiteBox", THREAD); 319 MutexLockerEx mu(Compile_lock); 320 return (mh->queued_for_compilation() || nm != NULL); 321 WB_END 322 323 WB_ENTRY(void, WB_ClearMethodState(JNIEnv* env, jobject o, jobject method)) 324 jmethodID jmid = reflected_method_to_jmid(thread, env, method); 325 methodHandle mh(THREAD, Method::checked_resolve_jmethod_id(jmid)); 326 MutexLockerEx mu(Compile_lock); 327 MethodData* mdo = mh->method_data(); 328 MethodCounters* mcs = mh->method_counters(); 329 330 if (mdo != NULL) { 331 mdo->init(); 332 ResourceMark rm; 333 int arg_count = mdo->method()->size_of_parameters(); 334 for (int i = 0; i < arg_count; i++) { 335 mdo->set_arg_modified(i, 0); 336 } 337 } 338 339 mh->clear_not_c1_compilable(); 340 mh->clear_not_c2_compilable(); 341 mh->clear_not_c2_osr_compilable(); 342 NOT_PRODUCT(mh->set_compiled_invocation_count(0)); 343 if (mcs != NULL) { 344 mcs->backedge_counter()->init(); 345 mcs->invocation_counter()->init(); 346 mcs->set_interpreter_invocation_count(0); 347 mcs->set_interpreter_throwout_count(0); 348 349 #ifdef TIERED 350 mcs->set_rate(0.0F); 351 mh->set_prev_event_count(0, THREAD); 352 mh->set_prev_time(0, THREAD); 353 #endif 354 } 355 WB_END 356 357 WB_ENTRY(jboolean, WB_IsInStringTable(JNIEnv* env, jobject o, jstring javaString)) 358 ResourceMark rm(THREAD); 359 int len; 360 jchar* name = java_lang_String::as_unicode_string(JNIHandles::resolve(javaString), len, CHECK_false); 361 return (StringTable::lookup(name, len) != NULL); 362 WB_END 363 364 WB_ENTRY(void, WB_FullGC(JNIEnv* env, jobject o)) 365 Universe::heap()->collector_policy()->set_should_clear_all_soft_refs(true); 366 Universe::heap()->collect(GCCause::_last_ditch_collection); 367 WB_END 368 369 370 WB_ENTRY(void, WB_ReadReservedMemory(JNIEnv* env, jobject o)) 371 // static+volatile in order to force the read to happen 372 // (not be eliminated by the compiler) 373 static char c; 374 static volatile char* p; 375 376 p = os::reserve_memory(os::vm_allocation_granularity(), NULL, 0); 377 if (p == NULL) { 378 THROW_MSG(vmSymbols::java_lang_OutOfMemoryError(), "Failed to reserve memory"); 379 } 380 381 c = *p; 382 WB_END 383 384 //Some convenience methods to deal with objects from java 385 int WhiteBox::offset_for_field(const char* field_name, oop object, 386 Symbol* signature_symbol) { 387 assert(field_name != NULL && strlen(field_name) > 0, "Field name not valid"); 388 Thread* THREAD = Thread::current(); 389 390 //Get the class of our object 391 Klass* arg_klass = object->klass(); 392 //Turn it into an instance-klass 393 InstanceKlass* ik = InstanceKlass::cast(arg_klass); 394 395 //Create symbols to look for in the class 396 TempNewSymbol name_symbol = SymbolTable::lookup(field_name, (int) strlen(field_name), 397 THREAD); 398 399 //To be filled in with an offset of the field we're looking for 400 fieldDescriptor fd; 401 402 Klass* res = ik->find_field(name_symbol, signature_symbol, &fd); 403 if (res == NULL) { 404 tty->print_cr("Invalid layout of %s at %s", ik->external_name(), 405 name_symbol->as_C_string()); 406 fatal("Invalid layout of preloaded class"); 407 } 408 409 //fetch the field at the offset we've found 410 int dest_offset = fd.offset(); 411 412 return dest_offset; 413 } 414 415 416 const char* WhiteBox::lookup_jstring(const char* field_name, oop object) { 417 int offset = offset_for_field(field_name, object, 418 vmSymbols::string_signature()); 419 oop string = object->obj_field(offset); 420 if (string == NULL) { 421 return NULL; 422 } 423 const char* ret = java_lang_String::as_utf8_string(string); 424 return ret; 425 } 426 427 bool WhiteBox::lookup_bool(const char* field_name, oop object) { 428 int offset = 429 offset_for_field(field_name, object, vmSymbols::bool_signature()); 430 bool ret = (object->bool_field(offset) == JNI_TRUE); 431 return ret; 432 } 433 434 435 #define CC (char*) 436 437 static JNINativeMethod methods[] = { 438 {CC"getObjectAddress", CC"(Ljava/lang/Object;)J", (void*)&WB_GetObjectAddress }, 439 {CC"getHeapOopSize", CC"()I", (void*)&WB_GetHeapOopSize }, 440 {CC"isClassAlive0", CC"(Ljava/lang/String;)Z", (void*)&WB_IsClassAlive }, 441 {CC"parseCommandLine", 442 CC"(Ljava/lang/String;[Lsun/hotspot/parser/DiagnosticCommand;)[Ljava/lang/Object;", 443 (void*) &WB_ParseCommandLine 444 }, 445 {CC"getCompressedOopsMaxHeapSize", CC"()J", 446 (void*)&WB_GetCompressedOopsMaxHeapSize}, 447 {CC"printHeapSizes", CC"()V", (void*)&WB_PrintHeapSizes }, 448 #if INCLUDE_ALL_GCS 449 {CC"g1InConcurrentMark", CC"()Z", (void*)&WB_G1InConcurrentMark}, 450 {CC"g1IsHumongous", CC"(Ljava/lang/Object;)Z", (void*)&WB_G1IsHumongous }, 451 {CC"g1NumFreeRegions", CC"()J", (void*)&WB_G1NumFreeRegions }, 452 {CC"g1RegionSize", CC"()I", (void*)&WB_G1RegionSize }, 453 #endif // INCLUDE_ALL_GCS 454 #if INCLUDE_NMT 455 {CC"NMTMalloc", CC"(J)J", (void*)&WB_NMTMalloc }, 456 {CC"NMTFree", CC"(J)V", (void*)&WB_NMTFree }, 457 {CC"NMTReserveMemory", CC"(J)J", (void*)&WB_NMTReserveMemory }, 458 {CC"NMTCommitMemory", CC"(JJ)V", (void*)&WB_NMTCommitMemory }, 459 {CC"NMTUncommitMemory", CC"(JJ)V", (void*)&WB_NMTUncommitMemory }, 460 {CC"NMTReleaseMemory", CC"(JJ)V", (void*)&WB_NMTReleaseMemory }, 461 {CC"NMTWaitForDataMerge", CC"()Z", (void*)&WB_NMTWaitForDataMerge}, 462 {CC"NMTIsDetailSupported",CC"()Z", (void*)&WB_NMTIsDetailSupported}, 463 #endif // INCLUDE_NMT 464 {CC"deoptimizeAll", CC"()V", (void*)&WB_DeoptimizeAll }, 465 {CC"deoptimizeMethod", CC"(Ljava/lang/reflect/Executable;Z)I", 466 (void*)&WB_DeoptimizeMethod }, 467 {CC"isMethodCompiled", CC"(Ljava/lang/reflect/Executable;Z)Z", 468 (void*)&WB_IsMethodCompiled }, 469 {CC"isMethodCompilable", CC"(Ljava/lang/reflect/Executable;IZ)Z", 470 (void*)&WB_IsMethodCompilable}, 471 {CC"isMethodQueuedForCompilation", 472 CC"(Ljava/lang/reflect/Executable;)Z", (void*)&WB_IsMethodQueuedForCompilation}, 473 {CC"makeMethodNotCompilable", 474 CC"(Ljava/lang/reflect/Executable;IZ)V", (void*)&WB_MakeMethodNotCompilable}, 475 {CC"testSetDontInlineMethod", 476 CC"(Ljava/lang/reflect/Executable;Z)Z", (void*)&WB_TestSetDontInlineMethod}, 477 {CC"getMethodCompilationLevel", 478 CC"(Ljava/lang/reflect/Executable;Z)I", (void*)&WB_GetMethodCompilationLevel}, 479 {CC"getMethodEntryBci", 480 CC"(Ljava/lang/reflect/Executable;)I", (void*)&WB_GetMethodEntryBci}, 481 {CC"getCompileQueueSize", 482 CC"(I)I", (void*)&WB_GetCompileQueueSize}, 483 {CC"testSetForceInlineMethod", 484 CC"(Ljava/lang/reflect/Executable;Z)Z", (void*)&WB_TestSetForceInlineMethod}, 485 {CC"enqueueMethodForCompilation", 486 CC"(Ljava/lang/reflect/Executable;II)Z", (void*)&WB_EnqueueMethodForCompilation}, 487 {CC"clearMethodState", 488 CC"(Ljava/lang/reflect/Executable;)V", (void*)&WB_ClearMethodState}, 489 {CC"isInStringTable", CC"(Ljava/lang/String;)Z", (void*)&WB_IsInStringTable }, 490 {CC"fullGC", CC"()V", (void*)&WB_FullGC }, 491 {CC"readReservedMemory", CC"()V", (void*)&WB_ReadReservedMemory }, 492 }; 493 494 #undef CC 495 496 JVM_ENTRY(void, JVM_RegisterWhiteBoxMethods(JNIEnv* env, jclass wbclass)) 497 { 498 if (WhiteBoxAPI) { 499 // Make sure that wbclass is loaded by the null classloader 500 instanceKlassHandle ikh = instanceKlassHandle(JNIHandles::resolve(wbclass)->klass()); 501 Handle loader(ikh->class_loader()); 502 if (loader.is_null()) { 503 ResourceMark rm; 504 ThreadToNativeFromVM ttnfv(thread); // can't be in VM when we call JNI 505 bool result = true; 506 // one by one registration natives for exception catching 507 jclass exceptionKlass = env->FindClass(vmSymbols::java_lang_NoSuchMethodError()->as_C_string()); 508 for (int i = 0, n = sizeof(methods) / sizeof(methods[0]); i < n; ++i) { 509 if (env->RegisterNatives(wbclass, methods + i, 1) != 0) { 510 result = false; 511 if (env->ExceptionCheck() && env->IsInstanceOf(env->ExceptionOccurred(), exceptionKlass)) { 512 // j.l.NoSuchMethodError is thrown when a method can't be found or a method is not native 513 // ignoring the exception 514 tty->print_cr("Warning: 'NoSuchMethodError' on register of sun.hotspot.WhiteBox::%s%s", methods[i].name, methods[i].signature); 515 env->ExceptionClear(); 516 } else { 517 // register is failed w/o exception or w/ unexpected exception 518 tty->print_cr("Warning: unexpected error on register of sun.hotspot.WhiteBox::%s%s. All methods will be unregistered", methods[i].name, methods[i].signature); 519 env->UnregisterNatives(wbclass); 520 break; 521 } 522 } 523 } 524 525 if (result) { 526 WhiteBox::set_used(); 527 } 528 } 529 } 530 } 531 JVM_END