1 /*
   2  * Copyright (c) 1997, 2011, 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/javaClasses.hpp"
  27 #include "classfile/systemDictionary.hpp"
  28 #include "classfile/verifier.hpp"
  29 #include "classfile/vmSymbols.hpp"
  30 #include "compiler/compileBroker.hpp"
  31 #include "gc_implementation/shared/markSweep.inline.hpp"
  32 #include "gc_interface/collectedHeap.inline.hpp"
  33 #include "interpreter/oopMapCache.hpp"
  34 #include "interpreter/rewriter.hpp"
  35 #include "jvmtifiles/jvmti.h"
  36 #include "memory/genOopClosures.inline.hpp"
  37 #include "memory/oopFactory.hpp"
  38 #include "memory/permGen.hpp"
  39 #include "oops/instanceKlass.hpp"
  40 #include "oops/instanceMirrorKlass.hpp"
  41 #include "oops/instanceOop.hpp"
  42 #include "oops/methodOop.hpp"
  43 #include "oops/objArrayKlassKlass.hpp"
  44 #include "oops/oop.inline.hpp"
  45 #include "oops/symbol.hpp"
  46 #include "prims/jvmtiExport.hpp"
  47 #include "prims/jvmtiRedefineClassesTrace.hpp"
  48 #include "runtime/fieldDescriptor.hpp"
  49 #include "runtime/handles.inline.hpp"
  50 #include "runtime/javaCalls.hpp"
  51 #include "runtime/mutexLocker.hpp"
  52 #include "services/threadService.hpp"
  53 #include "utilities/dtrace.hpp"
  54 #ifdef TARGET_OS_FAMILY_linux
  55 # include "thread_linux.inline.hpp"
  56 #endif
  57 #ifdef TARGET_OS_FAMILY_solaris
  58 # include "thread_solaris.inline.hpp"
  59 #endif
  60 #ifdef TARGET_OS_FAMILY_windows
  61 # include "thread_windows.inline.hpp"
  62 #endif
  63 #ifndef SERIALGC
  64 #include "gc_implementation/g1/g1CollectedHeap.inline.hpp"
  65 #include "gc_implementation/g1/g1OopClosures.inline.hpp"
  66 #include "gc_implementation/g1/g1RemSet.inline.hpp"
  67 #include "gc_implementation/g1/heapRegionSeq.inline.hpp"
  68 #include "gc_implementation/parNew/parOopClosures.inline.hpp"
  69 #include "gc_implementation/parallelScavenge/psPromotionManager.inline.hpp"
  70 #include "gc_implementation/parallelScavenge/psScavenge.inline.hpp"
  71 #include "oops/oop.pcgc.inline.hpp"
  72 #endif
  73 #ifdef COMPILER1
  74 #include "c1/c1_Compiler.hpp"
  75 #endif
  76 
  77 #ifdef DTRACE_ENABLED
  78 
  79 HS_DTRACE_PROBE_DECL4(hotspot, class__initialization__required,
  80   char*, intptr_t, oop, intptr_t);
  81 HS_DTRACE_PROBE_DECL5(hotspot, class__initialization__recursive,
  82   char*, intptr_t, oop, intptr_t, int);
  83 HS_DTRACE_PROBE_DECL5(hotspot, class__initialization__concurrent,
  84   char*, intptr_t, oop, intptr_t, int);
  85 HS_DTRACE_PROBE_DECL5(hotspot, class__initialization__erroneous,
  86   char*, intptr_t, oop, intptr_t, int);
  87 HS_DTRACE_PROBE_DECL5(hotspot, class__initialization__super__failed,
  88   char*, intptr_t, oop, intptr_t, int);
  89 HS_DTRACE_PROBE_DECL5(hotspot, class__initialization__clinit,
  90   char*, intptr_t, oop, intptr_t, int);
  91 HS_DTRACE_PROBE_DECL5(hotspot, class__initialization__error,
  92   char*, intptr_t, oop, intptr_t, int);
  93 HS_DTRACE_PROBE_DECL5(hotspot, class__initialization__end,
  94   char*, intptr_t, oop, intptr_t, int);
  95 
  96 #define DTRACE_CLASSINIT_PROBE(type, clss, thread_type)          \
  97   {                                                              \
  98     char* data = NULL;                                           \
  99     int len = 0;                                                 \
 100     Symbol* name = (clss)->name();                               \
 101     if (name != NULL) {                                          \
 102       data = (char*)name->bytes();                               \
 103       len = name->utf8_length();                                 \
 104     }                                                            \
 105     HS_DTRACE_PROBE4(hotspot, class__initialization__##type,     \
 106       data, len, (clss)->class_loader(), thread_type);           \
 107   }
 108 
 109 #define DTRACE_CLASSINIT_PROBE_WAIT(type, clss, thread_type, wait) \
 110   {                                                              \
 111     char* data = NULL;                                           \
 112     int len = 0;                                                 \
 113     Symbol* name = (clss)->name();                               \
 114     if (name != NULL) {                                          \
 115       data = (char*)name->bytes();                               \
 116       len = name->utf8_length();                                 \
 117     }                                                            \
 118     HS_DTRACE_PROBE5(hotspot, class__initialization__##type,     \
 119       data, len, (clss)->class_loader(), thread_type, wait);     \
 120   }
 121 
 122 #else //  ndef DTRACE_ENABLED
 123 
 124 #define DTRACE_CLASSINIT_PROBE(type, clss, thread_type)
 125 #define DTRACE_CLASSINIT_PROBE_WAIT(type, clss, thread_type, wait)
 126 
 127 #endif //  ndef DTRACE_ENABLED
 128 
 129 bool instanceKlass::should_be_initialized() const {
 130   return !is_initialized();
 131 }
 132 
 133 klassVtable* instanceKlass::vtable() const {
 134   return new klassVtable(as_klassOop(), start_of_vtable(), vtable_length() / vtableEntry::size());
 135 }
 136 
 137 klassItable* instanceKlass::itable() const {
 138   return new klassItable(as_klassOop());
 139 }
 140 
 141 void instanceKlass::eager_initialize(Thread *thread) {
 142   if (!EagerInitialization) return;
 143 
 144   if (this->is_not_initialized()) {
 145     // abort if the the class has a class initializer
 146     if (this->class_initializer() != NULL) return;
 147 
 148     // abort if it is java.lang.Object (initialization is handled in genesis)
 149     klassOop super = this->super();
 150     if (super == NULL) return;
 151 
 152     // abort if the super class should be initialized
 153     if (!instanceKlass::cast(super)->is_initialized()) return;
 154 
 155     // call body to expose the this pointer
 156     instanceKlassHandle this_oop(thread, this->as_klassOop());
 157     eager_initialize_impl(this_oop);
 158   }
 159 }
 160 
 161 
 162 void instanceKlass::eager_initialize_impl(instanceKlassHandle this_oop) {
 163   EXCEPTION_MARK;
 164   ObjectLocker ol(this_oop, THREAD);
 165 
 166   // abort if someone beat us to the initialization
 167   if (!this_oop->is_not_initialized()) return;  // note: not equivalent to is_initialized()
 168 
 169   ClassState old_state = this_oop->_init_state;
 170   link_class_impl(this_oop, true, THREAD);
 171   if (HAS_PENDING_EXCEPTION) {
 172     CLEAR_PENDING_EXCEPTION;
 173     // Abort if linking the class throws an exception.
 174 
 175     // Use a test to avoid redundantly resetting the state if there's
 176     // no change.  Set_init_state() asserts that state changes make
 177     // progress, whereas here we might just be spinning in place.
 178     if( old_state != this_oop->_init_state )
 179       this_oop->set_init_state (old_state);
 180   } else {
 181     // linking successfull, mark class as initialized
 182     this_oop->set_init_state (fully_initialized);
 183     // trace
 184     if (TraceClassInitialization) {
 185       ResourceMark rm(THREAD);
 186       tty->print_cr("[Initialized %s without side effects]", this_oop->external_name());
 187     }
 188   }
 189 }
 190 
 191 
 192 // See "The Virtual Machine Specification" section 2.16.5 for a detailed explanation of the class initialization
 193 // process. The step comments refers to the procedure described in that section.
 194 // Note: implementation moved to static method to expose the this pointer.
 195 void instanceKlass::initialize(TRAPS) {
 196   if (this->should_be_initialized()) {
 197     HandleMark hm(THREAD);
 198     instanceKlassHandle this_oop(THREAD, this->as_klassOop());
 199     initialize_impl(this_oop, CHECK);
 200     // Note: at this point the class may be initialized
 201     //       OR it may be in the state of being initialized
 202     //       in case of recursive initialization!
 203   } else {
 204     assert(is_initialized(), "sanity check");
 205   }
 206 }
 207 
 208 
 209 bool instanceKlass::verify_code(
 210     instanceKlassHandle this_oop, bool throw_verifyerror, TRAPS) {
 211   // 1) Verify the bytecodes
 212   Verifier::Mode mode =
 213     throw_verifyerror ? Verifier::ThrowException : Verifier::NoException;
 214   return Verifier::verify(this_oop, mode, this_oop->should_verify_class(), CHECK_false);
 215 }
 216 
 217 
 218 // Used exclusively by the shared spaces dump mechanism to prevent
 219 // classes mapped into the shared regions in new VMs from appearing linked.
 220 
 221 void instanceKlass::unlink_class() {
 222   assert(is_linked(), "must be linked");
 223   _init_state = loaded;
 224 }
 225 
 226 void instanceKlass::link_class(TRAPS) {
 227   assert(is_loaded(), "must be loaded");
 228   if (!is_linked()) {
 229     instanceKlassHandle this_oop(THREAD, this->as_klassOop());
 230     link_class_impl(this_oop, true, CHECK);
 231   }
 232 }
 233 
 234 // Called to verify that a class can link during initialization, without
 235 // throwing a VerifyError.
 236 bool instanceKlass::link_class_or_fail(TRAPS) {
 237   assert(is_loaded(), "must be loaded");
 238   if (!is_linked()) {
 239     instanceKlassHandle this_oop(THREAD, this->as_klassOop());
 240     link_class_impl(this_oop, false, CHECK_false);
 241   }
 242   return is_linked();
 243 }
 244 
 245 bool instanceKlass::link_class_impl(
 246     instanceKlassHandle this_oop, bool throw_verifyerror, TRAPS) {
 247   // check for error state
 248   if (this_oop->is_in_error_state()) {
 249     ResourceMark rm(THREAD);
 250     THROW_MSG_(vmSymbols::java_lang_NoClassDefFoundError(),
 251                this_oop->external_name(), false);
 252   }
 253   // return if already verified
 254   if (this_oop->is_linked()) {
 255     return true;
 256   }
 257 
 258   // Timing
 259   // timer handles recursion
 260   assert(THREAD->is_Java_thread(), "non-JavaThread in link_class_impl");
 261   JavaThread* jt = (JavaThread*)THREAD;
 262 
 263   // link super class before linking this class
 264   instanceKlassHandle super(THREAD, this_oop->super());
 265   if (super.not_null()) {
 266     if (super->is_interface()) {  // check if super class is an interface
 267       ResourceMark rm(THREAD);
 268       Exceptions::fthrow(
 269         THREAD_AND_LOCATION,
 270         vmSymbols::java_lang_IncompatibleClassChangeError(),
 271         "class %s has interface %s as super class",
 272         this_oop->external_name(),
 273         super->external_name()
 274       );
 275       return false;
 276     }
 277 
 278     link_class_impl(super, throw_verifyerror, CHECK_false);
 279   }
 280 
 281   // link all interfaces implemented by this class before linking this class
 282   objArrayHandle interfaces (THREAD, this_oop->local_interfaces());
 283   int num_interfaces = interfaces->length();
 284   for (int index = 0; index < num_interfaces; index++) {
 285     HandleMark hm(THREAD);
 286     instanceKlassHandle ih(THREAD, klassOop(interfaces->obj_at(index)));
 287     link_class_impl(ih, throw_verifyerror, CHECK_false);
 288   }
 289 
 290   // in case the class is linked in the process of linking its superclasses
 291   if (this_oop->is_linked()) {
 292     return true;
 293   }
 294 
 295   // trace only the link time for this klass that includes
 296   // the verification time
 297   PerfClassTraceTime vmtimer(ClassLoader::perf_class_link_time(),
 298                              ClassLoader::perf_class_link_selftime(),
 299                              ClassLoader::perf_classes_linked(),
 300                              jt->get_thread_stat()->perf_recursion_counts_addr(),
 301                              jt->get_thread_stat()->perf_timers_addr(),
 302                              PerfClassTraceTime::CLASS_LINK);
 303 
 304   // verification & rewriting
 305   {
 306     ObjectLocker ol(this_oop, THREAD);
 307     // rewritten will have been set if loader constraint error found
 308     // on an earlier link attempt
 309     // don't verify or rewrite if already rewritten
 310     if (!this_oop->is_linked()) {
 311       if (!this_oop->is_rewritten()) {
 312         {
 313           // Timer includes any side effects of class verification (resolution,
 314           // etc), but not recursive entry into verify_code().
 315           PerfClassTraceTime timer(ClassLoader::perf_class_verify_time(),
 316                                    ClassLoader::perf_class_verify_selftime(),
 317                                    ClassLoader::perf_classes_verified(),
 318                                    jt->get_thread_stat()->perf_recursion_counts_addr(),
 319                                    jt->get_thread_stat()->perf_timers_addr(),
 320                                    PerfClassTraceTime::CLASS_VERIFY);
 321           bool verify_ok = verify_code(this_oop, throw_verifyerror, THREAD);
 322           if (!verify_ok) {
 323             return false;
 324           }
 325         }
 326 
 327         // Just in case a side-effect of verify linked this class already
 328         // (which can sometimes happen since the verifier loads classes
 329         // using custom class loaders, which are free to initialize things)
 330         if (this_oop->is_linked()) {
 331           return true;
 332         }
 333 
 334         // also sets rewritten
 335         this_oop->rewrite_class(CHECK_false);
 336       }
 337 
 338       // relocate jsrs and link methods after they are all rewritten
 339       this_oop->relocate_and_link_methods(CHECK_false);
 340 
 341       // Initialize the vtable and interface table after
 342       // methods have been rewritten since rewrite may
 343       // fabricate new methodOops.
 344       // also does loader constraint checking
 345       if (!this_oop()->is_shared()) {
 346         ResourceMark rm(THREAD);
 347         this_oop->vtable()->initialize_vtable(true, CHECK_false);
 348         this_oop->itable()->initialize_itable(true, CHECK_false);
 349       }
 350 #ifdef ASSERT
 351       else {
 352         ResourceMark rm(THREAD);
 353         this_oop->vtable()->verify(tty, true);
 354         // In case itable verification is ever added.
 355         // this_oop->itable()->verify(tty, true);
 356       }
 357 #endif
 358       this_oop->set_init_state(linked);
 359       if (JvmtiExport::should_post_class_prepare()) {
 360         Thread *thread = THREAD;
 361         assert(thread->is_Java_thread(), "thread->is_Java_thread()");
 362         JvmtiExport::post_class_prepare((JavaThread *) thread, this_oop());
 363       }
 364     }
 365   }
 366   return true;
 367 }
 368 
 369 
 370 // Rewrite the byte codes of all of the methods of a class.
 371 // The rewriter must be called exactly once. Rewriting must happen after
 372 // verification but before the first method of the class is executed.
 373 void instanceKlass::rewrite_class(TRAPS) {
 374   assert(is_loaded(), "must be loaded");
 375   instanceKlassHandle this_oop(THREAD, this->as_klassOop());
 376   if (this_oop->is_rewritten()) {
 377     assert(this_oop()->is_shared(), "rewriting an unshared class?");
 378     return;
 379   }
 380   Rewriter::rewrite(this_oop, CHECK);
 381   this_oop->set_rewritten();
 382 }
 383 
 384 // Now relocate and link method entry points after class is rewritten.
 385 // This is outside is_rewritten flag. In case of an exception, it can be
 386 // executed more than once.
 387 void instanceKlass::relocate_and_link_methods(TRAPS) {
 388   assert(is_loaded(), "must be loaded");
 389   instanceKlassHandle this_oop(THREAD, this->as_klassOop());
 390   Rewriter::relocate_and_link(this_oop, CHECK);
 391 }
 392 
 393 
 394 void instanceKlass::initialize_impl(instanceKlassHandle this_oop, TRAPS) {
 395   // Make sure klass is linked (verified) before initialization
 396   // A class could already be verified, since it has been reflected upon.
 397   this_oop->link_class(CHECK);
 398 
 399   DTRACE_CLASSINIT_PROBE(required, instanceKlass::cast(this_oop()), -1);
 400 
 401   bool wait = false;
 402 
 403   // refer to the JVM book page 47 for description of steps
 404   // Step 1
 405   { ObjectLocker ol(this_oop, THREAD);
 406 
 407     Thread *self = THREAD; // it's passed the current thread
 408 
 409     // Step 2
 410     // If we were to use wait() instead of waitInterruptibly() then
 411     // we might end up throwing IE from link/symbol resolution sites
 412     // that aren't expected to throw.  This would wreak havoc.  See 6320309.
 413     while(this_oop->is_being_initialized() && !this_oop->is_reentrant_initialization(self)) {
 414         wait = true;
 415       ol.waitUninterruptibly(CHECK);
 416     }
 417 
 418     // Step 3
 419     if (this_oop->is_being_initialized() && this_oop->is_reentrant_initialization(self)) {
 420       DTRACE_CLASSINIT_PROBE_WAIT(recursive, instanceKlass::cast(this_oop()), -1,wait);
 421       return;
 422     }
 423 
 424     // Step 4
 425     if (this_oop->is_initialized()) {
 426       DTRACE_CLASSINIT_PROBE_WAIT(concurrent, instanceKlass::cast(this_oop()), -1,wait);
 427       return;
 428     }
 429 
 430     // Step 5
 431     if (this_oop->is_in_error_state()) {
 432       DTRACE_CLASSINIT_PROBE_WAIT(erroneous, instanceKlass::cast(this_oop()), -1,wait);
 433       ResourceMark rm(THREAD);
 434       const char* desc = "Could not initialize class ";
 435       const char* className = this_oop->external_name();
 436       size_t msglen = strlen(desc) + strlen(className) + 1;
 437       char* message = NEW_RESOURCE_ARRAY(char, msglen);
 438       if (NULL == message) {
 439         // Out of memory: can't create detailed error message
 440         THROW_MSG(vmSymbols::java_lang_NoClassDefFoundError(), className);
 441       } else {
 442         jio_snprintf(message, msglen, "%s%s", desc, className);
 443         THROW_MSG(vmSymbols::java_lang_NoClassDefFoundError(), message);
 444       }
 445     }
 446 
 447     // Step 6
 448     this_oop->set_init_state(being_initialized);
 449     this_oop->set_init_thread(self);
 450   }
 451 
 452   // Step 7
 453   klassOop super_klass = this_oop->super();
 454   if (super_klass != NULL && !this_oop->is_interface() && Klass::cast(super_klass)->should_be_initialized()) {
 455     Klass::cast(super_klass)->initialize(THREAD);
 456 
 457     if (HAS_PENDING_EXCEPTION) {
 458       Handle e(THREAD, PENDING_EXCEPTION);
 459       CLEAR_PENDING_EXCEPTION;
 460       {
 461         EXCEPTION_MARK;
 462         this_oop->set_initialization_state_and_notify(initialization_error, THREAD); // Locks object, set state, and notify all waiting threads
 463         CLEAR_PENDING_EXCEPTION;   // ignore any exception thrown, superclass initialization error is thrown below
 464       }
 465       DTRACE_CLASSINIT_PROBE_WAIT(super__failed, instanceKlass::cast(this_oop()), -1,wait);
 466       THROW_OOP(e());
 467     }
 468   }
 469 
 470   // Step 8
 471   {
 472     assert(THREAD->is_Java_thread(), "non-JavaThread in initialize_impl");
 473     JavaThread* jt = (JavaThread*)THREAD;
 474     DTRACE_CLASSINIT_PROBE_WAIT(clinit, instanceKlass::cast(this_oop()), -1,wait);
 475     // Timer includes any side effects of class initialization (resolution,
 476     // etc), but not recursive entry into call_class_initializer().
 477     PerfClassTraceTime timer(ClassLoader::perf_class_init_time(),
 478                              ClassLoader::perf_class_init_selftime(),
 479                              ClassLoader::perf_classes_inited(),
 480                              jt->get_thread_stat()->perf_recursion_counts_addr(),
 481                              jt->get_thread_stat()->perf_timers_addr(),
 482                              PerfClassTraceTime::CLASS_CLINIT);
 483     this_oop->call_class_initializer(THREAD);
 484   }
 485 
 486   // Step 9
 487   if (!HAS_PENDING_EXCEPTION) {
 488     this_oop->set_initialization_state_and_notify(fully_initialized, CHECK);
 489     { ResourceMark rm(THREAD);
 490       debug_only(this_oop->vtable()->verify(tty, true);)
 491     }
 492   }
 493   else {
 494     // Step 10 and 11
 495     Handle e(THREAD, PENDING_EXCEPTION);
 496     CLEAR_PENDING_EXCEPTION;
 497     {
 498       EXCEPTION_MARK;
 499       this_oop->set_initialization_state_and_notify(initialization_error, THREAD);
 500       CLEAR_PENDING_EXCEPTION;   // ignore any exception thrown, class initialization error is thrown below
 501     }
 502     DTRACE_CLASSINIT_PROBE_WAIT(error, instanceKlass::cast(this_oop()), -1,wait);
 503     if (e->is_a(SystemDictionary::Error_klass())) {
 504       THROW_OOP(e());
 505     } else {
 506       JavaCallArguments args(e);
 507       THROW_ARG(vmSymbols::java_lang_ExceptionInInitializerError(),
 508                 vmSymbols::throwable_void_signature(),
 509                 &args);
 510     }
 511   }
 512   DTRACE_CLASSINIT_PROBE_WAIT(end, instanceKlass::cast(this_oop()), -1,wait);
 513 }
 514 
 515 
 516 // Note: implementation moved to static method to expose the this pointer.
 517 void instanceKlass::set_initialization_state_and_notify(ClassState state, TRAPS) {
 518   instanceKlassHandle kh(THREAD, this->as_klassOop());
 519   set_initialization_state_and_notify_impl(kh, state, CHECK);
 520 }
 521 
 522 void instanceKlass::set_initialization_state_and_notify_impl(instanceKlassHandle this_oop, ClassState state, TRAPS) {
 523   ObjectLocker ol(this_oop, THREAD);
 524   this_oop->set_init_state(state);
 525   ol.notify_all(CHECK);
 526 }
 527 
 528 void instanceKlass::add_implementor(klassOop k) {
 529   assert(Compile_lock->owned_by_self(), "");
 530   // Filter out my subinterfaces.
 531   // (Note: Interfaces are never on the subklass list.)
 532   if (instanceKlass::cast(k)->is_interface()) return;
 533 
 534   // Filter out subclasses whose supers already implement me.
 535   // (Note: CHA must walk subclasses of direct implementors
 536   // in order to locate indirect implementors.)
 537   klassOop sk = instanceKlass::cast(k)->super();
 538   if (sk != NULL && instanceKlass::cast(sk)->implements_interface(as_klassOop()))
 539     // We only need to check one immediate superclass, since the
 540     // implements_interface query looks at transitive_interfaces.
 541     // Any supers of the super have the same (or fewer) transitive_interfaces.
 542     return;
 543 
 544   // Update number of implementors
 545   int i = _nof_implementors++;
 546 
 547   // Record this implementor, if there are not too many already
 548   if (i < implementors_limit) {
 549     assert(_implementors[i] == NULL, "should be exactly one implementor");
 550     oop_store_without_check((oop*)&_implementors[i], k);
 551   } else if (i == implementors_limit) {
 552     // clear out the list on first overflow
 553     for (int i2 = 0; i2 < implementors_limit; i2++)
 554       oop_store_without_check((oop*)&_implementors[i2], NULL);
 555   }
 556 
 557   // The implementor also implements the transitive_interfaces
 558   for (int index = 0; index < local_interfaces()->length(); index++) {
 559     instanceKlass::cast(klassOop(local_interfaces()->obj_at(index)))->add_implementor(k);
 560   }
 561 }
 562 
 563 void instanceKlass::init_implementor() {
 564   for (int i = 0; i < implementors_limit; i++)
 565     oop_store_without_check((oop*)&_implementors[i], NULL);
 566   _nof_implementors = 0;
 567 }
 568 
 569 
 570 void instanceKlass::process_interfaces(Thread *thread) {
 571   // link this class into the implementors list of every interface it implements
 572   KlassHandle this_as_oop (thread, this->as_klassOop());
 573   for (int i = local_interfaces()->length() - 1; i >= 0; i--) {
 574     assert(local_interfaces()->obj_at(i)->is_klass(), "must be a klass");
 575     instanceKlass* interf = instanceKlass::cast(klassOop(local_interfaces()->obj_at(i)));
 576     assert(interf->is_interface(), "expected interface");
 577     interf->add_implementor(this_as_oop());
 578   }
 579 }
 580 
 581 bool instanceKlass::can_be_primary_super_slow() const {
 582   if (is_interface())
 583     return false;
 584   else
 585     return Klass::can_be_primary_super_slow();
 586 }
 587 
 588 objArrayOop instanceKlass::compute_secondary_supers(int num_extra_slots, TRAPS) {
 589   // The secondaries are the implemented interfaces.
 590   instanceKlass* ik = instanceKlass::cast(as_klassOop());
 591   objArrayHandle interfaces (THREAD, ik->transitive_interfaces());
 592   int num_secondaries = num_extra_slots + interfaces->length();
 593   if (num_secondaries == 0) {
 594     return Universe::the_empty_system_obj_array();
 595   } else if (num_extra_slots == 0) {
 596     return interfaces();
 597   } else {
 598     // a mix of both
 599     objArrayOop secondaries = oopFactory::new_system_objArray(num_secondaries, CHECK_NULL);
 600     for (int i = 0; i < interfaces->length(); i++) {
 601       secondaries->obj_at_put(num_extra_slots+i, interfaces->obj_at(i));
 602     }
 603     return secondaries;
 604   }
 605 }
 606 
 607 bool instanceKlass::compute_is_subtype_of(klassOop k) {
 608   if (Klass::cast(k)->is_interface()) {
 609     return implements_interface(k);
 610   } else {
 611     return Klass::compute_is_subtype_of(k);
 612   }
 613 }
 614 
 615 bool instanceKlass::implements_interface(klassOop k) const {
 616   if (as_klassOop() == k) return true;
 617   assert(Klass::cast(k)->is_interface(), "should be an interface class");
 618   for (int i = 0; i < transitive_interfaces()->length(); i++) {
 619     if (transitive_interfaces()->obj_at(i) == k) {
 620       return true;
 621     }
 622   }
 623   return false;
 624 }
 625 
 626 objArrayOop instanceKlass::allocate_objArray(int n, int length, TRAPS) {
 627   if (length < 0) THROW_0(vmSymbols::java_lang_NegativeArraySizeException());
 628   if (length > arrayOopDesc::max_array_length(T_OBJECT)) {
 629     report_java_out_of_memory("Requested array size exceeds VM limit");
 630     THROW_OOP_0(Universe::out_of_memory_error_array_size());
 631   }
 632   int size = objArrayOopDesc::object_size(length);
 633   klassOop ak = array_klass(n, CHECK_NULL);
 634   KlassHandle h_ak (THREAD, ak);
 635   objArrayOop o =
 636     (objArrayOop)CollectedHeap::array_allocate(h_ak, size, length, CHECK_NULL);
 637   return o;
 638 }
 639 
 640 instanceOop instanceKlass::register_finalizer(instanceOop i, TRAPS) {
 641   if (TraceFinalizerRegistration) {
 642     tty->print("Registered ");
 643     i->print_value_on(tty);
 644     tty->print_cr(" (" INTPTR_FORMAT ") as finalizable", (address)i);
 645   }
 646   instanceHandle h_i(THREAD, i);
 647   // Pass the handle as argument, JavaCalls::call expects oop as jobjects
 648   JavaValue result(T_VOID);
 649   JavaCallArguments args(h_i);
 650   methodHandle mh (THREAD, Universe::finalizer_register_method());
 651   JavaCalls::call(&result, mh, &args, CHECK_NULL);
 652   return h_i();
 653 }
 654 
 655 instanceOop instanceKlass::allocate_instance(TRAPS) {
 656   assert(!oop_is_instanceMirror(), "wrong allocation path");
 657   bool has_finalizer_flag = has_finalizer(); // Query before possible GC
 658   int size = size_helper();  // Query before forming handle.
 659 
 660   KlassHandle h_k(THREAD, as_klassOop());
 661 
 662   instanceOop i;
 663 
 664   i = (instanceOop)CollectedHeap::obj_allocate(h_k, size, CHECK_NULL);
 665   if (has_finalizer_flag && !RegisterFinalizersAtInit) {
 666     i = register_finalizer(i, CHECK_NULL);
 667   }
 668   return i;
 669 }
 670 
 671 instanceOop instanceKlass::allocate_permanent_instance(TRAPS) {
 672   // Finalizer registration occurs in the Object.<init> constructor
 673   // and constructors normally aren't run when allocating perm
 674   // instances so simply disallow finalizable perm objects.  This can
 675   // be relaxed if a need for it is found.
 676   assert(!has_finalizer(), "perm objects not allowed to have finalizers");
 677   assert(!oop_is_instanceMirror(), "wrong allocation path");
 678   int size = size_helper();  // Query before forming handle.
 679   KlassHandle h_k(THREAD, as_klassOop());
 680   instanceOop i = (instanceOop)
 681     CollectedHeap::permanent_obj_allocate(h_k, size, CHECK_NULL);
 682   return i;
 683 }
 684 
 685 void instanceKlass::check_valid_for_instantiation(bool throwError, TRAPS) {
 686   if (is_interface() || is_abstract()) {
 687     ResourceMark rm(THREAD);
 688     THROW_MSG(throwError ? vmSymbols::java_lang_InstantiationError()
 689               : vmSymbols::java_lang_InstantiationException(), external_name());
 690   }
 691   if (as_klassOop() == SystemDictionary::Class_klass()) {
 692     ResourceMark rm(THREAD);
 693     THROW_MSG(throwError ? vmSymbols::java_lang_IllegalAccessError()
 694               : vmSymbols::java_lang_IllegalAccessException(), external_name());
 695   }
 696 }
 697 
 698 klassOop instanceKlass::array_klass_impl(bool or_null, int n, TRAPS) {
 699   instanceKlassHandle this_oop(THREAD, as_klassOop());
 700   return array_klass_impl(this_oop, or_null, n, THREAD);
 701 }
 702 
 703 klassOop instanceKlass::array_klass_impl(instanceKlassHandle this_oop, bool or_null, int n, TRAPS) {
 704   if (this_oop->array_klasses() == NULL) {
 705     if (or_null) return NULL;
 706 
 707     ResourceMark rm;
 708     JavaThread *jt = (JavaThread *)THREAD;
 709     {
 710       // Atomic creation of array_klasses
 711       MutexLocker mc(Compile_lock, THREAD);   // for vtables
 712       MutexLocker ma(MultiArray_lock, THREAD);
 713 
 714       // Check if update has already taken place
 715       if (this_oop->array_klasses() == NULL) {
 716         objArrayKlassKlass* oakk =
 717           (objArrayKlassKlass*)Universe::objArrayKlassKlassObj()->klass_part();
 718 
 719         klassOop  k = oakk->allocate_objArray_klass(1, this_oop, CHECK_NULL);
 720         this_oop->set_array_klasses(k);
 721       }
 722     }
 723   }
 724   // _this will always be set at this point
 725   objArrayKlass* oak = (objArrayKlass*)this_oop->array_klasses()->klass_part();
 726   if (or_null) {
 727     return oak->array_klass_or_null(n);
 728   }
 729   return oak->array_klass(n, CHECK_NULL);
 730 }
 731 
 732 klassOop instanceKlass::array_klass_impl(bool or_null, TRAPS) {
 733   return array_klass_impl(or_null, 1, THREAD);
 734 }
 735 
 736 void instanceKlass::call_class_initializer(TRAPS) {
 737   instanceKlassHandle ik (THREAD, as_klassOop());
 738   call_class_initializer_impl(ik, THREAD);
 739 }
 740 
 741 static int call_class_initializer_impl_counter = 0;   // for debugging
 742 
 743 methodOop instanceKlass::class_initializer() {
 744   methodOop clinit = find_method(
 745       vmSymbols::class_initializer_name(), vmSymbols::void_method_signature());
 746   if (clinit != NULL && clinit->has_valid_initializer_flags()) {
 747     return clinit;
 748   }
 749   return NULL;
 750 }
 751 
 752 void instanceKlass::call_class_initializer_impl(instanceKlassHandle this_oop, TRAPS) {
 753   methodHandle h_method(THREAD, this_oop->class_initializer());
 754   assert(!this_oop->is_initialized(), "we cannot initialize twice");
 755   if (TraceClassInitialization) {
 756     tty->print("%d Initializing ", call_class_initializer_impl_counter++);
 757     this_oop->name()->print_value();
 758     tty->print_cr("%s (" INTPTR_FORMAT ")", h_method() == NULL ? "(no method)" : "", (address)this_oop());
 759   }
 760   if (h_method() != NULL) {
 761     JavaCallArguments args; // No arguments
 762     JavaValue result(T_VOID);
 763     JavaCalls::call(&result, h_method, &args, CHECK); // Static call (no args)
 764   }
 765 }
 766 
 767 
 768 void instanceKlass::mask_for(methodHandle method, int bci,
 769   InterpreterOopMap* entry_for) {
 770   // Dirty read, then double-check under a lock.
 771   if (_oop_map_cache == NULL) {
 772     // Otherwise, allocate a new one.
 773     MutexLocker x(OopMapCacheAlloc_lock);
 774     // First time use. Allocate a cache in C heap
 775     if (_oop_map_cache == NULL) {
 776       _oop_map_cache = new OopMapCache();
 777     }
 778   }
 779   // _oop_map_cache is constant after init; lookup below does is own locking.
 780   _oop_map_cache->lookup(method, bci, entry_for);
 781 }
 782 
 783 
 784 bool instanceKlass::find_local_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
 785   const int n = fields()->length();
 786   for (int i = 0; i < n; i += next_offset ) {
 787     int name_index = fields()->ushort_at(i + name_index_offset);
 788     int sig_index  = fields()->ushort_at(i + signature_index_offset);
 789     Symbol* f_name = constants()->symbol_at(name_index);
 790     Symbol* f_sig  = constants()->symbol_at(sig_index);
 791     if (f_name == name && f_sig == sig) {
 792       fd->initialize(as_klassOop(), i);
 793       return true;
 794     }
 795   }
 796   return false;
 797 }
 798 
 799 
 800 void instanceKlass::shared_symbols_iterate(SymbolClosure* closure) {
 801   Klass::shared_symbols_iterate(closure);
 802   closure->do_symbol(&_generic_signature);
 803   closure->do_symbol(&_source_file_name);
 804   closure->do_symbol(&_source_debug_extension);
 805 
 806   const int n = fields()->length();
 807   for (int i = 0; i < n; i += next_offset ) {
 808     int name_index = fields()->ushort_at(i + name_index_offset);
 809     closure->do_symbol(constants()->symbol_at_addr(name_index));
 810     int sig_index  = fields()->ushort_at(i + signature_index_offset);
 811     closure->do_symbol(constants()->symbol_at_addr(sig_index));
 812   }
 813 }
 814 
 815 
 816 klassOop instanceKlass::find_interface_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
 817   const int n = local_interfaces()->length();
 818   for (int i = 0; i < n; i++) {
 819     klassOop intf1 = klassOop(local_interfaces()->obj_at(i));
 820     assert(Klass::cast(intf1)->is_interface(), "just checking type");
 821     // search for field in current interface
 822     if (instanceKlass::cast(intf1)->find_local_field(name, sig, fd)) {
 823       assert(fd->is_static(), "interface field must be static");
 824       return intf1;
 825     }
 826     // search for field in direct superinterfaces
 827     klassOop intf2 = instanceKlass::cast(intf1)->find_interface_field(name, sig, fd);
 828     if (intf2 != NULL) return intf2;
 829   }
 830   // otherwise field lookup fails
 831   return NULL;
 832 }
 833 
 834 
 835 klassOop instanceKlass::find_field(Symbol* name, Symbol* sig, fieldDescriptor* fd) const {
 836   // search order according to newest JVM spec (5.4.3.2, p.167).
 837   // 1) search for field in current klass
 838   if (find_local_field(name, sig, fd)) {
 839     return as_klassOop();
 840   }
 841   // 2) search for field recursively in direct superinterfaces
 842   { klassOop intf = find_interface_field(name, sig, fd);
 843     if (intf != NULL) return intf;
 844   }
 845   // 3) apply field lookup recursively if superclass exists
 846   { klassOop supr = super();
 847     if (supr != NULL) return instanceKlass::cast(supr)->find_field(name, sig, fd);
 848   }
 849   // 4) otherwise field lookup fails
 850   return NULL;
 851 }
 852 
 853 
 854 klassOop instanceKlass::find_field(Symbol* name, Symbol* sig, bool is_static, fieldDescriptor* fd) const {
 855   // search order according to newest JVM spec (5.4.3.2, p.167).
 856   // 1) search for field in current klass
 857   if (find_local_field(name, sig, fd)) {
 858     if (fd->is_static() == is_static) return as_klassOop();
 859   }
 860   // 2) search for field recursively in direct superinterfaces
 861   if (is_static) {
 862     klassOop intf = find_interface_field(name, sig, fd);
 863     if (intf != NULL) return intf;
 864   }
 865   // 3) apply field lookup recursively if superclass exists
 866   { klassOop supr = super();
 867     if (supr != NULL) return instanceKlass::cast(supr)->find_field(name, sig, is_static, fd);
 868   }
 869   // 4) otherwise field lookup fails
 870   return NULL;
 871 }
 872 
 873 
 874 bool instanceKlass::find_local_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const {
 875   int length = fields()->length();
 876   for (int i = 0; i < length; i += next_offset) {
 877     if (offset_from_fields( i ) == offset) {
 878       fd->initialize(as_klassOop(), i);
 879       if (fd->is_static() == is_static) return true;
 880     }
 881   }
 882   return false;
 883 }
 884 
 885 
 886 bool instanceKlass::find_field_from_offset(int offset, bool is_static, fieldDescriptor* fd) const {
 887   klassOop klass = as_klassOop();
 888   while (klass != NULL) {
 889     if (instanceKlass::cast(klass)->find_local_field_from_offset(offset, is_static, fd)) {
 890       return true;
 891     }
 892     klass = Klass::cast(klass)->super();
 893   }
 894   return false;
 895 }
 896 
 897 
 898 void instanceKlass::methods_do(void f(methodOop method)) {
 899   int len = methods()->length();
 900   for (int index = 0; index < len; index++) {
 901     methodOop m = methodOop(methods()->obj_at(index));
 902     assert(m->is_method(), "must be method");
 903     f(m);
 904   }
 905 }
 906 
 907 
 908 void instanceKlass::do_local_static_fields(FieldClosure* cl) {
 909   fieldDescriptor fd;
 910   int length = fields()->length();
 911   for (int i = 0; i < length; i += next_offset) {
 912     fd.initialize(as_klassOop(), i);
 913     if (fd.is_static()) cl->do_field(&fd);
 914   }
 915 }
 916 
 917 
 918 void instanceKlass::do_local_static_fields(void f(fieldDescriptor*, TRAPS), TRAPS) {
 919   instanceKlassHandle h_this(THREAD, as_klassOop());
 920   do_local_static_fields_impl(h_this, f, CHECK);
 921 }
 922 
 923 
 924 void instanceKlass::do_local_static_fields_impl(instanceKlassHandle this_oop, void f(fieldDescriptor* fd, TRAPS), TRAPS) {
 925   fieldDescriptor fd;
 926   int length = this_oop->fields()->length();
 927   for (int i = 0; i < length; i += next_offset) {
 928     fd.initialize(this_oop(), i);
 929     if (fd.is_static()) { f(&fd, CHECK); } // Do NOT remove {}! (CHECK macro expands into several statements)
 930   }
 931 }
 932 
 933 
 934 static int compare_fields_by_offset(int* a, int* b) {
 935   return a[0] - b[0];
 936 }
 937 
 938 void instanceKlass::do_nonstatic_fields(FieldClosure* cl) {
 939   instanceKlass* super = superklass();
 940   if (super != NULL) {
 941     super->do_nonstatic_fields(cl);
 942   }
 943   fieldDescriptor fd;
 944   int length = fields()->length();
 945   // In DebugInfo nonstatic fields are sorted by offset.
 946   int* fields_sorted = NEW_C_HEAP_ARRAY(int, 2*(length+1));
 947   int j = 0;
 948   for (int i = 0; i < length; i += next_offset) {
 949     fd.initialize(as_klassOop(), i);
 950     if (!fd.is_static()) {
 951       fields_sorted[j + 0] = fd.offset();
 952       fields_sorted[j + 1] = i;
 953       j += 2;
 954     }
 955   }
 956   if (j > 0) {
 957     length = j;
 958     // _sort_Fn is defined in growableArray.hpp.
 959     qsort(fields_sorted, length/2, 2*sizeof(int), (_sort_Fn)compare_fields_by_offset);
 960     for (int i = 0; i < length; i += 2) {
 961       fd.initialize(as_klassOop(), fields_sorted[i + 1]);
 962       assert(!fd.is_static() && fd.offset() == fields_sorted[i], "only nonstatic fields");
 963       cl->do_field(&fd);
 964     }
 965   }
 966   FREE_C_HEAP_ARRAY(int, fields_sorted);
 967 }
 968 
 969 
 970 void instanceKlass::array_klasses_do(void f(klassOop k)) {
 971   if (array_klasses() != NULL)
 972     arrayKlass::cast(array_klasses())->array_klasses_do(f);
 973 }
 974 
 975 
 976 void instanceKlass::with_array_klasses_do(void f(klassOop k)) {
 977   f(as_klassOop());
 978   array_klasses_do(f);
 979 }
 980 
 981 #ifdef ASSERT
 982 static int linear_search(objArrayOop methods, Symbol* name, Symbol* signature) {
 983   int len = methods->length();
 984   for (int index = 0; index < len; index++) {
 985     methodOop m = (methodOop)(methods->obj_at(index));
 986     assert(m->is_method(), "must be method");
 987     if (m->signature() == signature && m->name() == name) {
 988        return index;
 989     }
 990   }
 991   return -1;
 992 }
 993 #endif
 994 
 995 methodOop instanceKlass::find_method(Symbol* name, Symbol* signature) const {
 996   return instanceKlass::find_method(methods(), name, signature);
 997 }
 998 
 999 methodOop instanceKlass::find_method(objArrayOop methods, Symbol* name, Symbol* signature) {
1000   int len = methods->length();
1001   // methods are sorted, so do binary search
1002   int l = 0;
1003   int h = len - 1;
1004   while (l <= h) {
1005     int mid = (l + h) >> 1;
1006     methodOop m = (methodOop)methods->obj_at(mid);
1007     assert(m->is_method(), "must be method");
1008     int res = m->name()->fast_compare(name);
1009     if (res == 0) {
1010       // found matching name; do linear search to find matching signature
1011       // first, quick check for common case
1012       if (m->signature() == signature) return m;
1013       // search downwards through overloaded methods
1014       int i;
1015       for (i = mid - 1; i >= l; i--) {
1016         methodOop m = (methodOop)methods->obj_at(i);
1017         assert(m->is_method(), "must be method");
1018         if (m->name() != name) break;
1019         if (m->signature() == signature) return m;
1020       }
1021       // search upwards
1022       for (i = mid + 1; i <= h; i++) {
1023         methodOop m = (methodOop)methods->obj_at(i);
1024         assert(m->is_method(), "must be method");
1025         if (m->name() != name) break;
1026         if (m->signature() == signature) return m;
1027       }
1028       // not found
1029 #ifdef ASSERT
1030       int index = linear_search(methods, name, signature);
1031       assert(index == -1, err_msg("binary search should have found entry %d", index));
1032 #endif
1033       return NULL;
1034     } else if (res < 0) {
1035       l = mid + 1;
1036     } else {
1037       h = mid - 1;
1038     }
1039   }
1040 #ifdef ASSERT
1041   int index = linear_search(methods, name, signature);
1042   assert(index == -1, err_msg("binary search should have found entry %d", index));
1043 #endif
1044   return NULL;
1045 }
1046 
1047 methodOop instanceKlass::uncached_lookup_method(Symbol* name, Symbol* signature) const {
1048   klassOop klass = as_klassOop();
1049   while (klass != NULL) {
1050     methodOop method = instanceKlass::cast(klass)->find_method(name, signature);
1051     if (method != NULL) return method;
1052     klass = instanceKlass::cast(klass)->super();
1053   }
1054   return NULL;
1055 }
1056 
1057 // lookup a method in all the interfaces that this class implements
1058 methodOop instanceKlass::lookup_method_in_all_interfaces(Symbol* name,
1059                                                          Symbol* signature) const {
1060   objArrayOop all_ifs = instanceKlass::cast(as_klassOop())->transitive_interfaces();
1061   int num_ifs = all_ifs->length();
1062   instanceKlass *ik = NULL;
1063   for (int i = 0; i < num_ifs; i++) {
1064     ik = instanceKlass::cast(klassOop(all_ifs->obj_at(i)));
1065     methodOop m = ik->lookup_method(name, signature);
1066     if (m != NULL) {
1067       return m;
1068     }
1069   }
1070   return NULL;
1071 }
1072 
1073 /* jni_id_for_impl for jfieldIds only */
1074 JNIid* instanceKlass::jni_id_for_impl(instanceKlassHandle this_oop, int offset) {
1075   MutexLocker ml(JfieldIdCreation_lock);
1076   // Retry lookup after we got the lock
1077   JNIid* probe = this_oop->jni_ids() == NULL ? NULL : this_oop->jni_ids()->find(offset);
1078   if (probe == NULL) {
1079     // Slow case, allocate new static field identifier
1080     probe = new JNIid(this_oop->as_klassOop(), offset, this_oop->jni_ids());
1081     this_oop->set_jni_ids(probe);
1082   }
1083   return probe;
1084 }
1085 
1086 
1087 /* jni_id_for for jfieldIds only */
1088 JNIid* instanceKlass::jni_id_for(int offset) {
1089   JNIid* probe = jni_ids() == NULL ? NULL : jni_ids()->find(offset);
1090   if (probe == NULL) {
1091     probe = jni_id_for_impl(this->as_klassOop(), offset);
1092   }
1093   return probe;
1094 }
1095 
1096 
1097 // Lookup or create a jmethodID.
1098 // This code is called by the VMThread and JavaThreads so the
1099 // locking has to be done very carefully to avoid deadlocks
1100 // and/or other cache consistency problems.
1101 //
1102 jmethodID instanceKlass::get_jmethod_id(instanceKlassHandle ik_h, methodHandle method_h) {
1103   size_t idnum = (size_t)method_h->method_idnum();
1104   jmethodID* jmeths = ik_h->methods_jmethod_ids_acquire();
1105   size_t length = 0;
1106   jmethodID id = NULL;
1107 
1108   // We use a double-check locking idiom here because this cache is
1109   // performance sensitive. In the normal system, this cache only
1110   // transitions from NULL to non-NULL which is safe because we use
1111   // release_set_methods_jmethod_ids() to advertise the new cache.
1112   // A partially constructed cache should never be seen by a racing
1113   // thread. We also use release_store_ptr() to save a new jmethodID
1114   // in the cache so a partially constructed jmethodID should never be
1115   // seen either. Cache reads of existing jmethodIDs proceed without a
1116   // lock, but cache writes of a new jmethodID requires uniqueness and
1117   // creation of the cache itself requires no leaks so a lock is
1118   // generally acquired in those two cases.
1119   //
1120   // If the RedefineClasses() API has been used, then this cache can
1121   // grow and we'll have transitions from non-NULL to bigger non-NULL.
1122   // Cache creation requires no leaks and we require safety between all
1123   // cache accesses and freeing of the old cache so a lock is generally
1124   // acquired when the RedefineClasses() API has been used.
1125 
1126   if (jmeths != NULL) {
1127     // the cache already exists
1128     if (!ik_h->idnum_can_increment()) {
1129       // the cache can't grow so we can just get the current values
1130       get_jmethod_id_length_value(jmeths, idnum, &length, &id);
1131     } else {
1132       // cache can grow so we have to be more careful
1133       if (Threads::number_of_threads() == 0 ||
1134           SafepointSynchronize::is_at_safepoint()) {
1135         // we're single threaded or at a safepoint - no locking needed
1136         get_jmethod_id_length_value(jmeths, idnum, &length, &id);
1137       } else {
1138         MutexLocker ml(JmethodIdCreation_lock);
1139         get_jmethod_id_length_value(jmeths, idnum, &length, &id);
1140       }
1141     }
1142   }
1143   // implied else:
1144   // we need to allocate a cache so default length and id values are good
1145 
1146   if (jmeths == NULL ||   // no cache yet
1147       length <= idnum ||  // cache is too short
1148       id == NULL) {       // cache doesn't contain entry
1149 
1150     // This function can be called by the VMThread so we have to do all
1151     // things that might block on a safepoint before grabbing the lock.
1152     // Otherwise, we can deadlock with the VMThread or have a cache
1153     // consistency issue. These vars keep track of what we might have
1154     // to free after the lock is dropped.
1155     jmethodID  to_dealloc_id     = NULL;
1156     jmethodID* to_dealloc_jmeths = NULL;
1157 
1158     // may not allocate new_jmeths or use it if we allocate it
1159     jmethodID* new_jmeths = NULL;
1160     if (length <= idnum) {
1161       // allocate a new cache that might be used
1162       size_t size = MAX2(idnum+1, (size_t)ik_h->idnum_allocated_count());
1163       new_jmeths = NEW_C_HEAP_ARRAY(jmethodID, size+1);
1164       memset(new_jmeths, 0, (size+1)*sizeof(jmethodID));
1165       // cache size is stored in element[0], other elements offset by one
1166       new_jmeths[0] = (jmethodID)size;
1167     }
1168 
1169     // allocate a new jmethodID that might be used
1170     jmethodID new_id = NULL;
1171     if (method_h->is_old() && !method_h->is_obsolete()) {
1172       // The method passed in is old (but not obsolete), we need to use the current version
1173       methodOop current_method = ik_h->method_with_idnum((int)idnum);
1174       assert(current_method != NULL, "old and but not obsolete, so should exist");
1175       methodHandle current_method_h(current_method == NULL? method_h() : current_method);
1176       new_id = JNIHandles::make_jmethod_id(current_method_h);
1177     } else {
1178       // It is the current version of the method or an obsolete method,
1179       // use the version passed in
1180       new_id = JNIHandles::make_jmethod_id(method_h);
1181     }
1182 
1183     if (Threads::number_of_threads() == 0 ||
1184         SafepointSynchronize::is_at_safepoint()) {
1185       // we're single threaded or at a safepoint - no locking needed
1186       id = get_jmethod_id_fetch_or_update(ik_h, idnum, new_id, new_jmeths,
1187                                           &to_dealloc_id, &to_dealloc_jmeths);
1188     } else {
1189       MutexLocker ml(JmethodIdCreation_lock);
1190       id = get_jmethod_id_fetch_or_update(ik_h, idnum, new_id, new_jmeths,
1191                                           &to_dealloc_id, &to_dealloc_jmeths);
1192     }
1193 
1194     // The lock has been dropped so we can free resources.
1195     // Free up either the old cache or the new cache if we allocated one.
1196     if (to_dealloc_jmeths != NULL) {
1197       FreeHeap(to_dealloc_jmeths);
1198     }
1199     // free up the new ID since it wasn't needed
1200     if (to_dealloc_id != NULL) {
1201       JNIHandles::destroy_jmethod_id(to_dealloc_id);
1202     }
1203   }
1204   return id;
1205 }
1206 
1207 
1208 // Common code to fetch the jmethodID from the cache or update the
1209 // cache with the new jmethodID. This function should never do anything
1210 // that causes the caller to go to a safepoint or we can deadlock with
1211 // the VMThread or have cache consistency issues.
1212 //
1213 jmethodID instanceKlass::get_jmethod_id_fetch_or_update(
1214             instanceKlassHandle ik_h, size_t idnum, jmethodID new_id,
1215             jmethodID* new_jmeths, jmethodID* to_dealloc_id_p,
1216             jmethodID** to_dealloc_jmeths_p) {
1217   assert(new_id != NULL, "sanity check");
1218   assert(to_dealloc_id_p != NULL, "sanity check");
1219   assert(to_dealloc_jmeths_p != NULL, "sanity check");
1220   assert(Threads::number_of_threads() == 0 ||
1221          SafepointSynchronize::is_at_safepoint() ||
1222          JmethodIdCreation_lock->owned_by_self(), "sanity check");
1223 
1224   // reacquire the cache - we are locked, single threaded or at a safepoint
1225   jmethodID* jmeths = ik_h->methods_jmethod_ids_acquire();
1226   jmethodID  id     = NULL;
1227   size_t     length = 0;
1228 
1229   if (jmeths == NULL ||                         // no cache yet
1230       (length = (size_t)jmeths[0]) <= idnum) {  // cache is too short
1231     if (jmeths != NULL) {
1232       // copy any existing entries from the old cache
1233       for (size_t index = 0; index < length; index++) {
1234         new_jmeths[index+1] = jmeths[index+1];
1235       }
1236       *to_dealloc_jmeths_p = jmeths;  // save old cache for later delete
1237     }
1238     ik_h->release_set_methods_jmethod_ids(jmeths = new_jmeths);
1239   } else {
1240     // fetch jmethodID (if any) from the existing cache
1241     id = jmeths[idnum+1];
1242     *to_dealloc_jmeths_p = new_jmeths;  // save new cache for later delete
1243   }
1244   if (id == NULL) {
1245     // No matching jmethodID in the existing cache or we have a new
1246     // cache or we just grew the cache. This cache write is done here
1247     // by the first thread to win the foot race because a jmethodID
1248     // needs to be unique once it is generally available.
1249     id = new_id;
1250 
1251     // The jmethodID cache can be read while unlocked so we have to
1252     // make sure the new jmethodID is complete before installing it
1253     // in the cache.
1254     OrderAccess::release_store_ptr(&jmeths[idnum+1], id);
1255   } else {
1256     *to_dealloc_id_p = new_id; // save new id for later delete
1257   }
1258   return id;
1259 }
1260 
1261 
1262 // Common code to get the jmethodID cache length and the jmethodID
1263 // value at index idnum if there is one.
1264 //
1265 void instanceKlass::get_jmethod_id_length_value(jmethodID* cache,
1266        size_t idnum, size_t *length_p, jmethodID* id_p) {
1267   assert(cache != NULL, "sanity check");
1268   assert(length_p != NULL, "sanity check");
1269   assert(id_p != NULL, "sanity check");
1270 
1271   // cache size is stored in element[0], other elements offset by one
1272   *length_p = (size_t)cache[0];
1273   if (*length_p <= idnum) {  // cache is too short
1274     *id_p = NULL;
1275   } else {
1276     *id_p = cache[idnum+1];  // fetch jmethodID (if any)
1277   }
1278 }
1279 
1280 
1281 // Lookup a jmethodID, NULL if not found.  Do no blocking, no allocations, no handles
1282 jmethodID instanceKlass::jmethod_id_or_null(methodOop method) {
1283   size_t idnum = (size_t)method->method_idnum();
1284   jmethodID* jmeths = methods_jmethod_ids_acquire();
1285   size_t length;                                // length assigned as debugging crumb
1286   jmethodID id = NULL;
1287   if (jmeths != NULL &&                         // If there is a cache
1288       (length = (size_t)jmeths[0]) > idnum) {   // and if it is long enough,
1289     id = jmeths[idnum+1];                       // Look up the id (may be NULL)
1290   }
1291   return id;
1292 }
1293 
1294 
1295 // Cache an itable index
1296 void instanceKlass::set_cached_itable_index(size_t idnum, int index) {
1297   int* indices = methods_cached_itable_indices_acquire();
1298   int* to_dealloc_indices = NULL;
1299 
1300   // We use a double-check locking idiom here because this cache is
1301   // performance sensitive. In the normal system, this cache only
1302   // transitions from NULL to non-NULL which is safe because we use
1303   // release_set_methods_cached_itable_indices() to advertise the
1304   // new cache. A partially constructed cache should never be seen
1305   // by a racing thread. Cache reads and writes proceed without a
1306   // lock, but creation of the cache itself requires no leaks so a
1307   // lock is generally acquired in that case.
1308   //
1309   // If the RedefineClasses() API has been used, then this cache can
1310   // grow and we'll have transitions from non-NULL to bigger non-NULL.
1311   // Cache creation requires no leaks and we require safety between all
1312   // cache accesses and freeing of the old cache so a lock is generally
1313   // acquired when the RedefineClasses() API has been used.
1314 
1315   if (indices == NULL || idnum_can_increment()) {
1316     // we need a cache or the cache can grow
1317     MutexLocker ml(JNICachedItableIndex_lock);
1318     // reacquire the cache to see if another thread already did the work
1319     indices = methods_cached_itable_indices_acquire();
1320     size_t length = 0;
1321     // cache size is stored in element[0], other elements offset by one
1322     if (indices == NULL || (length = (size_t)indices[0]) <= idnum) {
1323       size_t size = MAX2(idnum+1, (size_t)idnum_allocated_count());
1324       int* new_indices = NEW_C_HEAP_ARRAY(int, size+1);
1325       new_indices[0] = (int)size;
1326       // copy any existing entries
1327       size_t i;
1328       for (i = 0; i < length; i++) {
1329         new_indices[i+1] = indices[i+1];
1330       }
1331       // Set all the rest to -1
1332       for (i = length; i < size; i++) {
1333         new_indices[i+1] = -1;
1334       }
1335       if (indices != NULL) {
1336         // We have an old cache to delete so save it for after we
1337         // drop the lock.
1338         to_dealloc_indices = indices;
1339       }
1340       release_set_methods_cached_itable_indices(indices = new_indices);
1341     }
1342 
1343     if (idnum_can_increment()) {
1344       // this cache can grow so we have to write to it safely
1345       indices[idnum+1] = index;
1346     }
1347   } else {
1348     CHECK_UNHANDLED_OOPS_ONLY(Thread::current()->clear_unhandled_oops());
1349   }
1350 
1351   if (!idnum_can_increment()) {
1352     // The cache cannot grow and this JNI itable index value does not
1353     // have to be unique like a jmethodID. If there is a race to set it,
1354     // it doesn't matter.
1355     indices[idnum+1] = index;
1356   }
1357 
1358   if (to_dealloc_indices != NULL) {
1359     // we allocated a new cache so free the old one
1360     FreeHeap(to_dealloc_indices);
1361   }
1362 }
1363 
1364 
1365 // Retrieve a cached itable index
1366 int instanceKlass::cached_itable_index(size_t idnum) {
1367   int* indices = methods_cached_itable_indices_acquire();
1368   if (indices != NULL && ((size_t)indices[0]) > idnum) {
1369      // indices exist and are long enough, retrieve possible cached
1370     return indices[idnum+1];
1371   }
1372   return -1;
1373 }
1374 
1375 
1376 //
1377 // nmethodBucket is used to record dependent nmethods for
1378 // deoptimization.  nmethod dependencies are actually <klass, method>
1379 // pairs but we really only care about the klass part for purposes of
1380 // finding nmethods which might need to be deoptimized.  Instead of
1381 // recording the method, a count of how many times a particular nmethod
1382 // was recorded is kept.  This ensures that any recording errors are
1383 // noticed since an nmethod should be removed as many times are it's
1384 // added.
1385 //
1386 class nmethodBucket {
1387  private:
1388   nmethod*       _nmethod;
1389   int            _count;
1390   nmethodBucket* _next;
1391 
1392  public:
1393   nmethodBucket(nmethod* nmethod, nmethodBucket* next) {
1394     _nmethod = nmethod;
1395     _next = next;
1396     _count = 1;
1397   }
1398   int count()                             { return _count; }
1399   int increment()                         { _count += 1; return _count; }
1400   int decrement()                         { _count -= 1; assert(_count >= 0, "don't underflow"); return _count; }
1401   nmethodBucket* next()                   { return _next; }
1402   void set_next(nmethodBucket* b)         { _next = b; }
1403   nmethod* get_nmethod()                  { return _nmethod; }
1404 };
1405 
1406 
1407 //
1408 // Walk the list of dependent nmethods searching for nmethods which
1409 // are dependent on the changes that were passed in and mark them for
1410 // deoptimization.  Returns the number of nmethods found.
1411 //
1412 int instanceKlass::mark_dependent_nmethods(DepChange& changes) {
1413   assert_locked_or_safepoint(CodeCache_lock);
1414   int found = 0;
1415   nmethodBucket* b = _dependencies;
1416   while (b != NULL) {
1417     nmethod* nm = b->get_nmethod();
1418     // since dependencies aren't removed until an nmethod becomes a zombie,
1419     // the dependency list may contain nmethods which aren't alive.
1420     if (nm->is_alive() && !nm->is_marked_for_deoptimization() && nm->check_dependency_on(changes)) {
1421       if (TraceDependencies) {
1422         ResourceMark rm;
1423         tty->print_cr("Marked for deoptimization");
1424         tty->print_cr("  context = %s", this->external_name());
1425         changes.print();
1426         nm->print();
1427         nm->print_dependencies();
1428       }
1429       nm->mark_for_deoptimization();
1430       found++;
1431     }
1432     b = b->next();
1433   }
1434   return found;
1435 }
1436 
1437 
1438 //
1439 // Add an nmethodBucket to the list of dependencies for this nmethod.
1440 // It's possible that an nmethod has multiple dependencies on this klass
1441 // so a count is kept for each bucket to guarantee that creation and
1442 // deletion of dependencies is consistent.
1443 //
1444 void instanceKlass::add_dependent_nmethod(nmethod* nm) {
1445   assert_locked_or_safepoint(CodeCache_lock);
1446   nmethodBucket* b = _dependencies;
1447   nmethodBucket* last = NULL;
1448   while (b != NULL) {
1449     if (nm == b->get_nmethod()) {
1450       b->increment();
1451       return;
1452     }
1453     b = b->next();
1454   }
1455   _dependencies = new nmethodBucket(nm, _dependencies);
1456 }
1457 
1458 
1459 //
1460 // Decrement count of the nmethod in the dependency list and remove
1461 // the bucket competely when the count goes to 0.  This method must
1462 // find a corresponding bucket otherwise there's a bug in the
1463 // recording of dependecies.
1464 //
1465 void instanceKlass::remove_dependent_nmethod(nmethod* nm) {
1466   assert_locked_or_safepoint(CodeCache_lock);
1467   nmethodBucket* b = _dependencies;
1468   nmethodBucket* last = NULL;
1469   while (b != NULL) {
1470     if (nm == b->get_nmethod()) {
1471       if (b->decrement() == 0) {
1472         if (last == NULL) {
1473           _dependencies = b->next();
1474         } else {
1475           last->set_next(b->next());
1476         }
1477         delete b;
1478       }
1479       return;
1480     }
1481     last = b;
1482     b = b->next();
1483   }
1484 #ifdef ASSERT
1485   tty->print_cr("### %s can't find dependent nmethod:", this->external_name());
1486   nm->print();
1487 #endif // ASSERT
1488   ShouldNotReachHere();
1489 }
1490 
1491 
1492 #ifndef PRODUCT
1493 void instanceKlass::print_dependent_nmethods(bool verbose) {
1494   nmethodBucket* b = _dependencies;
1495   int idx = 0;
1496   while (b != NULL) {
1497     nmethod* nm = b->get_nmethod();
1498     tty->print("[%d] count=%d { ", idx++, b->count());
1499     if (!verbose) {
1500       nm->print_on(tty, "nmethod");
1501       tty->print_cr(" } ");
1502     } else {
1503       nm->print();
1504       nm->print_dependencies();
1505       tty->print_cr("--- } ");
1506     }
1507     b = b->next();
1508   }
1509 }
1510 
1511 
1512 bool instanceKlass::is_dependent_nmethod(nmethod* nm) {
1513   nmethodBucket* b = _dependencies;
1514   while (b != NULL) {
1515     if (nm == b->get_nmethod()) {
1516       return true;
1517     }
1518     b = b->next();
1519   }
1520   return false;
1521 }
1522 #endif //PRODUCT
1523 
1524 
1525 #ifdef ASSERT
1526 template <class T> void assert_is_in(T *p) {
1527   T heap_oop = oopDesc::load_heap_oop(p);
1528   if (!oopDesc::is_null(heap_oop)) {
1529     oop o = oopDesc::decode_heap_oop_not_null(heap_oop);
1530     assert(Universe::heap()->is_in(o), "should be in heap");
1531   }
1532 }
1533 template <class T> void assert_is_in_closed_subset(T *p) {
1534   T heap_oop = oopDesc::load_heap_oop(p);
1535   if (!oopDesc::is_null(heap_oop)) {
1536     oop o = oopDesc::decode_heap_oop_not_null(heap_oop);
1537     assert(Universe::heap()->is_in_closed_subset(o), "should be in closed");
1538   }
1539 }
1540 template <class T> void assert_is_in_reserved(T *p) {
1541   T heap_oop = oopDesc::load_heap_oop(p);
1542   if (!oopDesc::is_null(heap_oop)) {
1543     oop o = oopDesc::decode_heap_oop_not_null(heap_oop);
1544     assert(Universe::heap()->is_in_reserved(o), "should be in reserved");
1545   }
1546 }
1547 template <class T> void assert_nothing(T *p) {}
1548 
1549 #else
1550 template <class T> void assert_is_in(T *p) {}
1551 template <class T> void assert_is_in_closed_subset(T *p) {}
1552 template <class T> void assert_is_in_reserved(T *p) {}
1553 template <class T> void assert_nothing(T *p) {}
1554 #endif // ASSERT
1555 
1556 //
1557 // Macros that iterate over areas of oops which are specialized on type of
1558 // oop pointer either narrow or wide, depending on UseCompressedOops
1559 //
1560 // Parameters are:
1561 //   T         - type of oop to point to (either oop or narrowOop)
1562 //   start_p   - starting pointer for region to iterate over
1563 //   count     - number of oops or narrowOops to iterate over
1564 //   do_oop    - action to perform on each oop (it's arbitrary C code which
1565 //               makes it more efficient to put in a macro rather than making
1566 //               it a template function)
1567 //   assert_fn - assert function which is template function because performance
1568 //               doesn't matter when enabled.
1569 #define InstanceKlass_SPECIALIZED_OOP_ITERATE( \
1570   T, start_p, count, do_oop,                \
1571   assert_fn)                                \
1572 {                                           \
1573   T* p         = (T*)(start_p);             \
1574   T* const end = p + (count);               \
1575   while (p < end) {                         \
1576     (assert_fn)(p);                         \
1577     do_oop;                                 \
1578     ++p;                                    \
1579   }                                         \
1580 }
1581 
1582 #define InstanceKlass_SPECIALIZED_OOP_REVERSE_ITERATE( \
1583   T, start_p, count, do_oop,                \
1584   assert_fn)                                \
1585 {                                           \
1586   T* const start = (T*)(start_p);           \
1587   T*       p     = start + (count);         \
1588   while (start < p) {                       \
1589     --p;                                    \
1590     (assert_fn)(p);                         \
1591     do_oop;                                 \
1592   }                                         \
1593 }
1594 
1595 #define InstanceKlass_SPECIALIZED_BOUNDED_OOP_ITERATE( \
1596   T, start_p, count, low, high,             \
1597   do_oop, assert_fn)                        \
1598 {                                           \
1599   T* const l = (T*)(low);                   \
1600   T* const h = (T*)(high);                  \
1601   assert(mask_bits((intptr_t)l, sizeof(T)-1) == 0 && \
1602          mask_bits((intptr_t)h, sizeof(T)-1) == 0,   \
1603          "bounded region must be properly aligned"); \
1604   T* p       = (T*)(start_p);               \
1605   T* end     = p + (count);                 \
1606   if (p < l) p = l;                         \
1607   if (end > h) end = h;                     \
1608   while (p < end) {                         \
1609     (assert_fn)(p);                         \
1610     do_oop;                                 \
1611     ++p;                                    \
1612   }                                         \
1613 }
1614 
1615 
1616 // The following macros call specialized macros, passing either oop or
1617 // narrowOop as the specialization type.  These test the UseCompressedOops
1618 // flag.
1619 #define InstanceKlass_OOP_MAP_ITERATE(obj, do_oop, assert_fn)            \
1620 {                                                                        \
1621   /* Compute oopmap block range. The common case                         \
1622      is nonstatic_oop_map_size == 1. */                                  \
1623   OopMapBlock* map           = start_of_nonstatic_oop_maps();            \
1624   OopMapBlock* const end_map = map + nonstatic_oop_map_count();          \
1625   if (UseCompressedOops) {                                               \
1626     while (map < end_map) {                                              \
1627       InstanceKlass_SPECIALIZED_OOP_ITERATE(narrowOop,                   \
1628         obj->obj_field_addr<narrowOop>(map->offset()), map->count(),     \
1629         do_oop, assert_fn)                                               \
1630       ++map;                                                             \
1631     }                                                                    \
1632   } else {                                                               \
1633     while (map < end_map) {                                              \
1634       InstanceKlass_SPECIALIZED_OOP_ITERATE(oop,                         \
1635         obj->obj_field_addr<oop>(map->offset()), map->count(),           \
1636         do_oop, assert_fn)                                               \
1637       ++map;                                                             \
1638     }                                                                    \
1639   }                                                                      \
1640 }
1641 
1642 #define InstanceKlass_OOP_MAP_REVERSE_ITERATE(obj, do_oop, assert_fn)    \
1643 {                                                                        \
1644   OopMapBlock* const start_map = start_of_nonstatic_oop_maps();          \
1645   OopMapBlock* map             = start_map + nonstatic_oop_map_count();  \
1646   if (UseCompressedOops) {                                               \
1647     while (start_map < map) {                                            \
1648       --map;                                                             \
1649       InstanceKlass_SPECIALIZED_OOP_REVERSE_ITERATE(narrowOop,           \
1650         obj->obj_field_addr<narrowOop>(map->offset()), map->count(),     \
1651         do_oop, assert_fn)                                               \
1652     }                                                                    \
1653   } else {                                                               \
1654     while (start_map < map) {                                            \
1655       --map;                                                             \
1656       InstanceKlass_SPECIALIZED_OOP_REVERSE_ITERATE(oop,                 \
1657         obj->obj_field_addr<oop>(map->offset()), map->count(),           \
1658         do_oop, assert_fn)                                               \
1659     }                                                                    \
1660   }                                                                      \
1661 }
1662 
1663 #define InstanceKlass_BOUNDED_OOP_MAP_ITERATE(obj, low, high, do_oop,    \
1664                                               assert_fn)                 \
1665 {                                                                        \
1666   /* Compute oopmap block range. The common case is                      \
1667      nonstatic_oop_map_size == 1, so we accept the                       \
1668      usually non-existent extra overhead of examining                    \
1669      all the maps. */                                                    \
1670   OopMapBlock* map           = start_of_nonstatic_oop_maps();            \
1671   OopMapBlock* const end_map = map + nonstatic_oop_map_count();          \
1672   if (UseCompressedOops) {                                               \
1673     while (map < end_map) {                                              \
1674       InstanceKlass_SPECIALIZED_BOUNDED_OOP_ITERATE(narrowOop,           \
1675         obj->obj_field_addr<narrowOop>(map->offset()), map->count(),     \
1676         low, high,                                                       \
1677         do_oop, assert_fn)                                               \
1678       ++map;                                                             \
1679     }                                                                    \
1680   } else {                                                               \
1681     while (map < end_map) {                                              \
1682       InstanceKlass_SPECIALIZED_BOUNDED_OOP_ITERATE(oop,                 \
1683         obj->obj_field_addr<oop>(map->offset()), map->count(),           \
1684         low, high,                                                       \
1685         do_oop, assert_fn)                                               \
1686       ++map;                                                             \
1687     }                                                                    \
1688   }                                                                      \
1689 }
1690 
1691 void instanceKlass::oop_follow_contents(oop obj) {
1692   assert(obj != NULL, "can't follow the content of NULL object");
1693   obj->follow_header();
1694   InstanceKlass_OOP_MAP_ITERATE( \
1695     obj, \
1696     MarkSweep::mark_and_push(p), \
1697     assert_is_in_closed_subset)
1698 }
1699 
1700 #ifndef SERIALGC
1701 void instanceKlass::oop_follow_contents(ParCompactionManager* cm,
1702                                         oop obj) {
1703   assert(obj != NULL, "can't follow the content of NULL object");
1704   obj->follow_header(cm);
1705   InstanceKlass_OOP_MAP_ITERATE( \
1706     obj, \
1707     PSParallelCompact::mark_and_push(cm, p), \
1708     assert_is_in)
1709 }
1710 #endif // SERIALGC
1711 
1712 // closure's do_header() method dicates whether the given closure should be
1713 // applied to the klass ptr in the object header.
1714 
1715 #define InstanceKlass_OOP_OOP_ITERATE_DEFN(OopClosureType, nv_suffix)        \
1716                                                                              \
1717 int instanceKlass::oop_oop_iterate##nv_suffix(oop obj, OopClosureType* closure) { \
1718   SpecializationStats::record_iterate_call##nv_suffix(SpecializationStats::ik);\
1719   /* header */                                                          \
1720   if (closure->do_header()) {                                           \
1721     obj->oop_iterate_header(closure);                                   \
1722   }                                                                     \
1723   InstanceKlass_OOP_MAP_ITERATE(                                        \
1724     obj,                                                                \
1725     SpecializationStats::                                               \
1726       record_do_oop_call##nv_suffix(SpecializationStats::ik);           \
1727     (closure)->do_oop##nv_suffix(p),                                    \
1728     assert_is_in_closed_subset)                                         \
1729   return size_helper();                                                 \
1730 }
1731 
1732 #ifndef SERIALGC
1733 #define InstanceKlass_OOP_OOP_ITERATE_BACKWARDS_DEFN(OopClosureType, nv_suffix) \
1734                                                                                 \
1735 int instanceKlass::oop_oop_iterate_backwards##nv_suffix(oop obj,                \
1736                                               OopClosureType* closure) {        \
1737   SpecializationStats::record_iterate_call##nv_suffix(SpecializationStats::ik); \
1738   /* header */                                                                  \
1739   if (closure->do_header()) {                                                   \
1740     obj->oop_iterate_header(closure);                                           \
1741   }                                                                             \
1742   /* instance variables */                                                      \
1743   InstanceKlass_OOP_MAP_REVERSE_ITERATE(                                        \
1744     obj,                                                                        \
1745     SpecializationStats::record_do_oop_call##nv_suffix(SpecializationStats::ik);\
1746     (closure)->do_oop##nv_suffix(p),                                            \
1747     assert_is_in_closed_subset)                                                 \
1748    return size_helper();                                                        \
1749 }
1750 #endif // !SERIALGC
1751 
1752 #define InstanceKlass_OOP_OOP_ITERATE_DEFN_m(OopClosureType, nv_suffix) \
1753                                                                         \
1754 int instanceKlass::oop_oop_iterate##nv_suffix##_m(oop obj,              \
1755                                                   OopClosureType* closure, \
1756                                                   MemRegion mr) {          \
1757   SpecializationStats::record_iterate_call##nv_suffix(SpecializationStats::ik);\
1758   if (closure->do_header()) {                                            \
1759     obj->oop_iterate_header(closure, mr);                                \
1760   }                                                                      \
1761   InstanceKlass_BOUNDED_OOP_MAP_ITERATE(                                 \
1762     obj, mr.start(), mr.end(),                                           \
1763     (closure)->do_oop##nv_suffix(p),                                     \
1764     assert_is_in_closed_subset)                                          \
1765   return size_helper();                                                  \
1766 }
1767 
1768 ALL_OOP_OOP_ITERATE_CLOSURES_1(InstanceKlass_OOP_OOP_ITERATE_DEFN)
1769 ALL_OOP_OOP_ITERATE_CLOSURES_2(InstanceKlass_OOP_OOP_ITERATE_DEFN)
1770 ALL_OOP_OOP_ITERATE_CLOSURES_1(InstanceKlass_OOP_OOP_ITERATE_DEFN_m)
1771 ALL_OOP_OOP_ITERATE_CLOSURES_2(InstanceKlass_OOP_OOP_ITERATE_DEFN_m)
1772 #ifndef SERIALGC
1773 ALL_OOP_OOP_ITERATE_CLOSURES_1(InstanceKlass_OOP_OOP_ITERATE_BACKWARDS_DEFN)
1774 ALL_OOP_OOP_ITERATE_CLOSURES_2(InstanceKlass_OOP_OOP_ITERATE_BACKWARDS_DEFN)
1775 #endif // !SERIALGC
1776 
1777 int instanceKlass::oop_adjust_pointers(oop obj) {
1778   int size = size_helper();
1779   InstanceKlass_OOP_MAP_ITERATE( \
1780     obj, \
1781     MarkSweep::adjust_pointer(p), \
1782     assert_is_in)
1783   obj->adjust_header();
1784   return size;
1785 }
1786 
1787 #ifndef SERIALGC
1788 void instanceKlass::oop_push_contents(PSPromotionManager* pm, oop obj) {
1789   InstanceKlass_OOP_MAP_REVERSE_ITERATE( \
1790     obj, \
1791     if (PSScavenge::should_scavenge(p)) { \
1792       pm->claim_or_forward_depth(p); \
1793     }, \
1794     assert_nothing )
1795 }
1796 
1797 int instanceKlass::oop_update_pointers(ParCompactionManager* cm, oop obj) {
1798   InstanceKlass_OOP_MAP_ITERATE( \
1799     obj, \
1800     PSParallelCompact::adjust_pointer(p), \
1801     assert_nothing)
1802   return size_helper();
1803 }
1804 
1805 #endif // SERIALGC
1806 
1807 // This klass is alive but the implementor link is not followed/updated.
1808 // Subklass and sibling links are handled by Klass::follow_weak_klass_links
1809 
1810 void instanceKlass::follow_weak_klass_links(
1811   BoolObjectClosure* is_alive, OopClosure* keep_alive) {
1812   assert(is_alive->do_object_b(as_klassOop()), "this oop should be live");
1813   if (ClassUnloading) {
1814     for (int i = 0; i < implementors_limit; i++) {
1815       klassOop impl = _implementors[i];
1816       if (impl == NULL)  break;  // no more in the list
1817       if (!is_alive->do_object_b(impl)) {
1818         // remove this guy from the list by overwriting him with the tail
1819         int lasti = --_nof_implementors;
1820         assert(lasti >= i && lasti < implementors_limit, "just checking");
1821         _implementors[i] = _implementors[lasti];
1822         _implementors[lasti] = NULL;
1823         --i; // rerun the loop at this index
1824       }
1825     }
1826   } else {
1827     for (int i = 0; i < implementors_limit; i++) {
1828       keep_alive->do_oop(&adr_implementors()[i]);
1829     }
1830   }
1831   Klass::follow_weak_klass_links(is_alive, keep_alive);
1832 }
1833 
1834 void instanceKlass::remove_unshareable_info() {
1835   Klass::remove_unshareable_info();
1836   init_implementor();
1837 }
1838 
1839 static void clear_all_breakpoints(methodOop m) {
1840   m->clear_all_breakpoints();
1841 }
1842 
1843 void instanceKlass::release_C_heap_structures() {
1844   // Deallocate oop map cache
1845   if (_oop_map_cache != NULL) {
1846     delete _oop_map_cache;
1847     _oop_map_cache = NULL;
1848   }
1849 
1850   // Deallocate JNI identifiers for jfieldIDs
1851   JNIid::deallocate(jni_ids());
1852   set_jni_ids(NULL);
1853 
1854   jmethodID* jmeths = methods_jmethod_ids_acquire();
1855   if (jmeths != (jmethodID*)NULL) {
1856     release_set_methods_jmethod_ids(NULL);
1857     FreeHeap(jmeths);
1858   }
1859 
1860   int* indices = methods_cached_itable_indices_acquire();
1861   if (indices != (int*)NULL) {
1862     release_set_methods_cached_itable_indices(NULL);
1863     FreeHeap(indices);
1864   }
1865 
1866   // release dependencies
1867   nmethodBucket* b = _dependencies;
1868   _dependencies = NULL;
1869   while (b != NULL) {
1870     nmethodBucket* next = b->next();
1871     delete b;
1872     b = next;
1873   }
1874 
1875   // Deallocate breakpoint records
1876   if (breakpoints() != 0x0) {
1877     methods_do(clear_all_breakpoints);
1878     assert(breakpoints() == 0x0, "should have cleared breakpoints");
1879   }
1880 
1881   // deallocate information about previous versions
1882   if (_previous_versions != NULL) {
1883     for (int i = _previous_versions->length() - 1; i >= 0; i--) {
1884       PreviousVersionNode * pv_node = _previous_versions->at(i);
1885       delete pv_node;
1886     }
1887     delete _previous_versions;
1888     _previous_versions = NULL;
1889   }
1890 
1891   // deallocate the cached class file
1892   if (_cached_class_file_bytes != NULL) {
1893     os::free(_cached_class_file_bytes);
1894     _cached_class_file_bytes = NULL;
1895     _cached_class_file_len = 0;
1896   }
1897 
1898   // Decrement symbol reference counts associated with the unloaded class.
1899   if (_name != NULL) _name->decrement_refcount();
1900   // unreference array name derived from this class name (arrays of an unloaded
1901   // class can't be referenced anymore).
1902   if (_array_name != NULL)  _array_name->decrement_refcount();
1903   if (_source_file_name != NULL) _source_file_name->decrement_refcount();
1904   if (_source_debug_extension != NULL) _source_debug_extension->decrement_refcount();
1905   // walk constant pool and decrement symbol reference counts
1906   _constants->unreference_symbols();
1907 }
1908 
1909 void instanceKlass::set_source_file_name(Symbol* n) {
1910   _source_file_name = n;
1911   if (_source_file_name != NULL) _source_file_name->increment_refcount();
1912 }
1913 
1914 void instanceKlass::set_source_debug_extension(Symbol* n) {
1915   _source_debug_extension = n;
1916   if (_source_debug_extension != NULL) _source_debug_extension->increment_refcount();
1917 }
1918 
1919 address instanceKlass::static_field_addr(int offset) {
1920   return (address)(offset + instanceMirrorKlass::offset_of_static_fields() + (intptr_t)java_mirror());
1921 }
1922 
1923 
1924 const char* instanceKlass::signature_name() const {
1925   const char* src = (const char*) (name()->as_C_string());
1926   const int src_length = (int)strlen(src);
1927   char* dest = NEW_RESOURCE_ARRAY(char, src_length + 3);
1928   int src_index = 0;
1929   int dest_index = 0;
1930   dest[dest_index++] = 'L';
1931   while (src_index < src_length) {
1932     dest[dest_index++] = src[src_index++];
1933   }
1934   dest[dest_index++] = ';';
1935   dest[dest_index] = '\0';
1936   return dest;
1937 }
1938 
1939 // different verisons of is_same_class_package
1940 bool instanceKlass::is_same_class_package(klassOop class2) {
1941   klassOop class1 = as_klassOop();
1942   oop classloader1 = instanceKlass::cast(class1)->class_loader();
1943   Symbol* classname1 = Klass::cast(class1)->name();
1944 
1945   if (Klass::cast(class2)->oop_is_objArray()) {
1946     class2 = objArrayKlass::cast(class2)->bottom_klass();
1947   }
1948   oop classloader2;
1949   if (Klass::cast(class2)->oop_is_instance()) {
1950     classloader2 = instanceKlass::cast(class2)->class_loader();
1951   } else {
1952     assert(Klass::cast(class2)->oop_is_typeArray(), "should be type array");
1953     classloader2 = NULL;
1954   }
1955   Symbol* classname2 = Klass::cast(class2)->name();
1956 
1957   return instanceKlass::is_same_class_package(classloader1, classname1,
1958                                               classloader2, classname2);
1959 }
1960 
1961 bool instanceKlass::is_same_class_package(oop classloader2, Symbol* classname2) {
1962   klassOop class1 = as_klassOop();
1963   oop classloader1 = instanceKlass::cast(class1)->class_loader();
1964   Symbol* classname1 = Klass::cast(class1)->name();
1965 
1966   return instanceKlass::is_same_class_package(classloader1, classname1,
1967                                               classloader2, classname2);
1968 }
1969 
1970 // return true if two classes are in the same package, classloader
1971 // and classname information is enough to determine a class's package
1972 bool instanceKlass::is_same_class_package(oop class_loader1, Symbol* class_name1,
1973                                           oop class_loader2, Symbol* class_name2) {
1974   if (class_loader1 != class_loader2) {
1975     return false;
1976   } else if (class_name1 == class_name2) {
1977     return true;                // skip painful bytewise comparison
1978   } else {
1979     ResourceMark rm;
1980 
1981     // The Symbol*'s are in UTF8 encoding. Since we only need to check explicitly
1982     // for ASCII characters ('/', 'L', '['), we can keep them in UTF8 encoding.
1983     // Otherwise, we just compare jbyte values between the strings.
1984     const jbyte *name1 = class_name1->base();
1985     const jbyte *name2 = class_name2->base();
1986 
1987     const jbyte *last_slash1 = UTF8::strrchr(name1, class_name1->utf8_length(), '/');
1988     const jbyte *last_slash2 = UTF8::strrchr(name2, class_name2->utf8_length(), '/');
1989 
1990     if ((last_slash1 == NULL) || (last_slash2 == NULL)) {
1991       // One of the two doesn't have a package.  Only return true
1992       // if the other one also doesn't have a package.
1993       return last_slash1 == last_slash2;
1994     } else {
1995       // Skip over '['s
1996       if (*name1 == '[') {
1997         do {
1998           name1++;
1999         } while (*name1 == '[');
2000         if (*name1 != 'L') {
2001           // Something is terribly wrong.  Shouldn't be here.
2002           return false;
2003         }
2004       }
2005       if (*name2 == '[') {
2006         do {
2007           name2++;
2008         } while (*name2 == '[');
2009         if (*name2 != 'L') {
2010           // Something is terribly wrong.  Shouldn't be here.
2011           return false;
2012         }
2013       }
2014 
2015       // Check that package part is identical
2016       int length1 = last_slash1 - name1;
2017       int length2 = last_slash2 - name2;
2018 
2019       return UTF8::equal(name1, length1, name2, length2);
2020     }
2021   }
2022 }
2023 
2024 // Returns true iff super_method can be overridden by a method in targetclassname
2025 // See JSL 3rd edition 8.4.6.1
2026 // Assumes name-signature match
2027 // "this" is instanceKlass of super_method which must exist
2028 // note that the instanceKlass of the method in the targetclassname has not always been created yet
2029 bool instanceKlass::is_override(methodHandle super_method, Handle targetclassloader, Symbol* targetclassname, TRAPS) {
2030    // Private methods can not be overridden
2031    if (super_method->is_private()) {
2032      return false;
2033    }
2034    // If super method is accessible, then override
2035    if ((super_method->is_protected()) ||
2036        (super_method->is_public())) {
2037      return true;
2038    }
2039    // Package-private methods are not inherited outside of package
2040    assert(super_method->is_package_private(), "must be package private");
2041    return(is_same_class_package(targetclassloader(), targetclassname));
2042 }
2043 
2044 /* defined for now in jvm.cpp, for historical reasons *--
2045 klassOop instanceKlass::compute_enclosing_class_impl(instanceKlassHandle self,
2046                                                      Symbol*& simple_name_result, TRAPS) {
2047   ...
2048 }
2049 */
2050 
2051 // tell if two classes have the same enclosing class (at package level)
2052 bool instanceKlass::is_same_package_member_impl(instanceKlassHandle class1,
2053                                                 klassOop class2_oop, TRAPS) {
2054   if (class2_oop == class1->as_klassOop())          return true;
2055   if (!Klass::cast(class2_oop)->oop_is_instance())  return false;
2056   instanceKlassHandle class2(THREAD, class2_oop);
2057 
2058   // must be in same package before we try anything else
2059   if (!class1->is_same_class_package(class2->class_loader(), class2->name()))
2060     return false;
2061 
2062   // As long as there is an outer1.getEnclosingClass,
2063   // shift the search outward.
2064   instanceKlassHandle outer1 = class1;
2065   for (;;) {
2066     // As we walk along, look for equalities between outer1 and class2.
2067     // Eventually, the walks will terminate as outer1 stops
2068     // at the top-level class around the original class.
2069     bool ignore_inner_is_member;
2070     klassOop next = outer1->compute_enclosing_class(&ignore_inner_is_member,
2071                                                     CHECK_false);
2072     if (next == NULL)  break;
2073     if (next == class2())  return true;
2074     outer1 = instanceKlassHandle(THREAD, next);
2075   }
2076 
2077   // Now do the same for class2.
2078   instanceKlassHandle outer2 = class2;
2079   for (;;) {
2080     bool ignore_inner_is_member;
2081     klassOop next = outer2->compute_enclosing_class(&ignore_inner_is_member,
2082                                                     CHECK_false);
2083     if (next == NULL)  break;
2084     // Might as well check the new outer against all available values.
2085     if (next == class1())  return true;
2086     if (next == outer1())  return true;
2087     outer2 = instanceKlassHandle(THREAD, next);
2088   }
2089 
2090   // If by this point we have not found an equality between the
2091   // two classes, we know they are in separate package members.
2092   return false;
2093 }
2094 
2095 
2096 jint instanceKlass::compute_modifier_flags(TRAPS) const {
2097   klassOop k = as_klassOop();
2098   jint access = access_flags().as_int();
2099 
2100   // But check if it happens to be member class.
2101   typeArrayOop inner_class_list = inner_classes();
2102   int length = (inner_class_list == NULL) ? 0 : inner_class_list->length();
2103   assert (length % instanceKlass::inner_class_next_offset == 0, "just checking");
2104   if (length > 0) {
2105     typeArrayHandle inner_class_list_h(THREAD, inner_class_list);
2106     instanceKlassHandle ik(THREAD, k);
2107     for (int i = 0; i < length; i += instanceKlass::inner_class_next_offset) {
2108       int ioff = inner_class_list_h->ushort_at(
2109                       i + instanceKlass::inner_class_inner_class_info_offset);
2110 
2111       // Inner class attribute can be zero, skip it.
2112       // Strange but true:  JVM spec. allows null inner class refs.
2113       if (ioff == 0) continue;
2114 
2115       // only look at classes that are already loaded
2116       // since we are looking for the flags for our self.
2117       Symbol* inner_name = ik->constants()->klass_name_at(ioff);
2118       if ((ik->name() == inner_name)) {
2119         // This is really a member class.
2120         access = inner_class_list_h->ushort_at(i + instanceKlass::inner_class_access_flags_offset);
2121         break;
2122       }
2123     }
2124   }
2125   // Remember to strip ACC_SUPER bit
2126   return (access & (~JVM_ACC_SUPER)) & JVM_ACC_WRITTEN_FLAGS;
2127 }
2128 
2129 jint instanceKlass::jvmti_class_status() const {
2130   jint result = 0;
2131 
2132   if (is_linked()) {
2133     result |= JVMTI_CLASS_STATUS_VERIFIED | JVMTI_CLASS_STATUS_PREPARED;
2134   }
2135 
2136   if (is_initialized()) {
2137     assert(is_linked(), "Class status is not consistent");
2138     result |= JVMTI_CLASS_STATUS_INITIALIZED;
2139   }
2140   if (is_in_error_state()) {
2141     result |= JVMTI_CLASS_STATUS_ERROR;
2142   }
2143   return result;
2144 }
2145 
2146 methodOop instanceKlass::method_at_itable(klassOop holder, int index, TRAPS) {
2147   itableOffsetEntry* ioe = (itableOffsetEntry*)start_of_itable();
2148   int method_table_offset_in_words = ioe->offset()/wordSize;
2149   int nof_interfaces = (method_table_offset_in_words - itable_offset_in_words())
2150                        / itableOffsetEntry::size();
2151 
2152   for (int cnt = 0 ; ; cnt ++, ioe ++) {
2153     // If the interface isn't implemented by the receiver class,
2154     // the VM should throw IncompatibleClassChangeError.
2155     if (cnt >= nof_interfaces) {
2156       THROW_0(vmSymbols::java_lang_IncompatibleClassChangeError());
2157     }
2158 
2159     klassOop ik = ioe->interface_klass();
2160     if (ik == holder) break;
2161   }
2162 
2163   itableMethodEntry* ime = ioe->first_method_entry(as_klassOop());
2164   methodOop m = ime[index].method();
2165   if (m == NULL) {
2166     THROW_0(vmSymbols::java_lang_AbstractMethodError());
2167   }
2168   return m;
2169 }
2170 
2171 // On-stack replacement stuff
2172 void instanceKlass::add_osr_nmethod(nmethod* n) {
2173   // only one compilation can be active
2174   NEEDS_CLEANUP
2175   // This is a short non-blocking critical region, so the no safepoint check is ok.
2176   OsrList_lock->lock_without_safepoint_check();
2177   assert(n->is_osr_method(), "wrong kind of nmethod");
2178   n->set_osr_link(osr_nmethods_head());
2179   set_osr_nmethods_head(n);
2180   // Raise the highest osr level if necessary
2181   if (TieredCompilation) {
2182     methodOop m = n->method();
2183     m->set_highest_osr_comp_level(MAX2(m->highest_osr_comp_level(), n->comp_level()));
2184   }
2185   // Remember to unlock again
2186   OsrList_lock->unlock();
2187 
2188   // Get rid of the osr methods for the same bci that have lower levels.
2189   if (TieredCompilation) {
2190     for (int l = CompLevel_limited_profile; l < n->comp_level(); l++) {
2191       nmethod *inv = lookup_osr_nmethod(n->method(), n->osr_entry_bci(), l, true);
2192       if (inv != NULL && inv->is_in_use()) {
2193         inv->make_not_entrant();
2194       }
2195     }
2196   }
2197 }
2198 
2199 
2200 void instanceKlass::remove_osr_nmethod(nmethod* n) {
2201   // This is a short non-blocking critical region, so the no safepoint check is ok.
2202   OsrList_lock->lock_without_safepoint_check();
2203   assert(n->is_osr_method(), "wrong kind of nmethod");
2204   nmethod* last = NULL;
2205   nmethod* cur  = osr_nmethods_head();
2206   int max_level = CompLevel_none;  // Find the max comp level excluding n
2207   methodOop m = n->method();
2208   // Search for match
2209   while(cur != NULL && cur != n) {
2210     if (TieredCompilation) {
2211       // Find max level before n
2212       max_level = MAX2(max_level, cur->comp_level());
2213     }
2214     last = cur;
2215     cur = cur->osr_link();
2216   }
2217   nmethod* next = NULL;
2218   if (cur == n) {
2219     next = cur->osr_link();
2220     if (last == NULL) {
2221       // Remove first element
2222       set_osr_nmethods_head(next);
2223     } else {
2224       last->set_osr_link(next);
2225     }
2226   }
2227   n->set_osr_link(NULL);
2228   if (TieredCompilation) {
2229     cur = next;
2230     while (cur != NULL) {
2231       // Find max level after n
2232       max_level = MAX2(max_level, cur->comp_level());
2233       cur = cur->osr_link();
2234     }
2235     m->set_highest_osr_comp_level(max_level);
2236   }
2237   // Remember to unlock again
2238   OsrList_lock->unlock();
2239 }
2240 
2241 nmethod* instanceKlass::lookup_osr_nmethod(const methodOop m, int bci, int comp_level, bool match_level) const {
2242   // This is a short non-blocking critical region, so the no safepoint check is ok.
2243   OsrList_lock->lock_without_safepoint_check();
2244   nmethod* osr = osr_nmethods_head();
2245   nmethod* best = NULL;
2246   while (osr != NULL) {
2247     assert(osr->is_osr_method(), "wrong kind of nmethod found in chain");
2248     // There can be a time when a c1 osr method exists but we are waiting
2249     // for a c2 version. When c2 completes its osr nmethod we will trash
2250     // the c1 version and only be able to find the c2 version. However
2251     // while we overflow in the c1 code at back branches we don't want to
2252     // try and switch to the same code as we are already running
2253 
2254     if (osr->method() == m &&
2255         (bci == InvocationEntryBci || osr->osr_entry_bci() == bci)) {
2256       if (match_level) {
2257         if (osr->comp_level() == comp_level) {
2258           // Found a match - return it.
2259           OsrList_lock->unlock();
2260           return osr;
2261         }
2262       } else {
2263         if (best == NULL || (osr->comp_level() > best->comp_level())) {
2264           if (osr->comp_level() == CompLevel_highest_tier) {
2265             // Found the best possible - return it.
2266             OsrList_lock->unlock();
2267             return osr;
2268           }
2269           best = osr;
2270         }
2271       }
2272     }
2273     osr = osr->osr_link();
2274   }
2275   OsrList_lock->unlock();
2276   if (best != NULL && best->comp_level() >= comp_level && match_level == false) {
2277     return best;
2278   }
2279   return NULL;
2280 }
2281 
2282 // -----------------------------------------------------------------------------------------------------
2283 #ifndef PRODUCT
2284 
2285 // Printing
2286 
2287 #define BULLET  " - "
2288 
2289 void FieldPrinter::do_field(fieldDescriptor* fd) {
2290   _st->print(BULLET);
2291    if (_obj == NULL) {
2292      fd->print_on(_st);
2293      _st->cr();
2294    } else {
2295      fd->print_on_for(_st, _obj);
2296      _st->cr();
2297    }
2298 }
2299 
2300 
2301 void instanceKlass::oop_print_on(oop obj, outputStream* st) {
2302   Klass::oop_print_on(obj, st);
2303 
2304   if (as_klassOop() == SystemDictionary::String_klass()) {
2305     typeArrayOop value  = java_lang_String::value(obj);
2306     juint        offset = java_lang_String::offset(obj);
2307     juint        length = java_lang_String::length(obj);
2308     if (value != NULL &&
2309         value->is_typeArray() &&
2310         offset          <= (juint) value->length() &&
2311         offset + length <= (juint) value->length()) {
2312       st->print(BULLET"string: ");
2313       Handle h_obj(obj);
2314       java_lang_String::print(h_obj, st);
2315       st->cr();
2316       if (!WizardMode)  return;  // that is enough
2317     }
2318   }
2319 
2320   st->print_cr(BULLET"---- fields (total size %d words):", oop_size(obj));
2321   FieldPrinter print_field(st, obj);
2322   do_nonstatic_fields(&print_field);
2323 
2324   if (as_klassOop() == SystemDictionary::Class_klass()) {
2325     st->print(BULLET"signature: ");
2326     java_lang_Class::print_signature(obj, st);
2327     st->cr();
2328     klassOop mirrored_klass = java_lang_Class::as_klassOop(obj);
2329     st->print(BULLET"fake entry for mirror: ");
2330     mirrored_klass->print_value_on(st);
2331     st->cr();
2332     st->print(BULLET"fake entry resolved_constructor: ");
2333     methodOop ctor = java_lang_Class::resolved_constructor(obj);
2334     ctor->print_value_on(st);
2335     klassOop array_klass = java_lang_Class::array_klass(obj);
2336     st->cr();
2337     st->print(BULLET"fake entry for array: ");
2338     array_klass->print_value_on(st);
2339     st->cr();
2340     st->print_cr(BULLET"fake entry for oop_size: %d", java_lang_Class::oop_size(obj));
2341     st->print_cr(BULLET"fake entry for static_oop_field_count: %d", java_lang_Class::static_oop_field_count(obj));
2342     klassOop real_klass = java_lang_Class::as_klassOop(obj);
2343     if (real_klass != NULL && real_klass->klass_part()->oop_is_instance()) {
2344       instanceKlass::cast(real_klass)->do_local_static_fields(&print_field);
2345     }
2346   } else if (as_klassOop() == SystemDictionary::MethodType_klass()) {
2347     st->print(BULLET"signature: ");
2348     java_lang_invoke_MethodType::print_signature(obj, st);
2349     st->cr();
2350   }
2351 }
2352 
2353 #endif //PRODUCT
2354 
2355 void instanceKlass::oop_print_value_on(oop obj, outputStream* st) {
2356   st->print("a ");
2357   name()->print_value_on(st);
2358   obj->print_address_on(st);
2359   if (as_klassOop() == SystemDictionary::String_klass()
2360       && java_lang_String::value(obj) != NULL) {
2361     ResourceMark rm;
2362     int len = java_lang_String::length(obj);
2363     int plen = (len < 24 ? len : 12);
2364     char* str = java_lang_String::as_utf8_string(obj, 0, plen);
2365     st->print(" = \"%s\"", str);
2366     if (len > plen)
2367       st->print("...[%d]", len);
2368   } else if (as_klassOop() == SystemDictionary::Class_klass()) {
2369     klassOop k = java_lang_Class::as_klassOop(obj);
2370     st->print(" = ");
2371     if (k != NULL) {
2372       k->print_value_on(st);
2373     } else {
2374       const char* tname = type2name(java_lang_Class::primitive_type(obj));
2375       st->print("%s", tname ? tname : "type?");
2376     }
2377   } else if (as_klassOop() == SystemDictionary::MethodType_klass()) {
2378     st->print(" = ");
2379     java_lang_invoke_MethodType::print_signature(obj, st);
2380   } else if (java_lang_boxing_object::is_instance(obj)) {
2381     st->print(" = ");
2382     java_lang_boxing_object::print(obj, st);
2383   }
2384 }
2385 
2386 const char* instanceKlass::internal_name() const {
2387   return external_name();
2388 }
2389 
2390 // Verification
2391 
2392 class VerifyFieldClosure: public OopClosure {
2393  protected:
2394   template <class T> void do_oop_work(T* p) {
2395     guarantee(Universe::heap()->is_in_closed_subset(p), "should be in heap");
2396     oop obj = oopDesc::load_decode_heap_oop(p);
2397     if (!obj->is_oop_or_null()) {
2398       tty->print_cr("Failed: " PTR_FORMAT " -> " PTR_FORMAT, p, (address)obj);
2399       Universe::print();
2400       guarantee(false, "boom");
2401     }
2402   }
2403  public:
2404   virtual void do_oop(oop* p)       { VerifyFieldClosure::do_oop_work(p); }
2405   virtual void do_oop(narrowOop* p) { VerifyFieldClosure::do_oop_work(p); }
2406 };
2407 
2408 void instanceKlass::oop_verify_on(oop obj, outputStream* st) {
2409   Klass::oop_verify_on(obj, st);
2410   VerifyFieldClosure blk;
2411   oop_oop_iterate(obj, &blk);
2412 }
2413 
2414 #ifndef PRODUCT
2415 
2416 void instanceKlass::verify_class_klass_nonstatic_oop_maps(klassOop k) {
2417   // This verification code is disabled.  JDK_Version::is_gte_jdk14x_version()
2418   // cannot be called since this function is called before the VM is
2419   // able to determine what JDK version is running with.
2420   // The check below always is false since 1.4.
2421   return;
2422 
2423   // This verification code temporarily disabled for the 1.4
2424   // reflection implementation since java.lang.Class now has
2425   // Java-level instance fields. Should rewrite this to handle this
2426   // case.
2427   if (!(JDK_Version::is_gte_jdk14x_version() && UseNewReflection)) {
2428     // Verify that java.lang.Class instances have a fake oop field added.
2429     instanceKlass* ik = instanceKlass::cast(k);
2430 
2431     // Check that we have the right class
2432     static bool first_time = true;
2433     guarantee(k == SystemDictionary::Class_klass() && first_time, "Invalid verify of maps");
2434     first_time = false;
2435     const int extra = java_lang_Class::number_of_fake_oop_fields;
2436     guarantee(ik->nonstatic_field_size() == extra, "just checking");
2437     guarantee(ik->nonstatic_oop_map_count() == 1, "just checking");
2438     guarantee(ik->size_helper() == align_object_size(instanceOopDesc::header_size() + extra), "just checking");
2439 
2440     // Check that the map is (2,extra)
2441     int offset = java_lang_Class::klass_offset;
2442 
2443     OopMapBlock* map = ik->start_of_nonstatic_oop_maps();
2444     guarantee(map->offset() == offset && map->count() == (unsigned int) extra,
2445               "sanity");
2446   }
2447 }
2448 
2449 #endif // ndef PRODUCT
2450 
2451 // JNIid class for jfieldIDs only
2452 // Note to reviewers:
2453 // These JNI functions are just moved over to column 1 and not changed
2454 // in the compressed oops workspace.
2455 JNIid::JNIid(klassOop holder, int offset, JNIid* next) {
2456   _holder = holder;
2457   _offset = offset;
2458   _next = next;
2459   debug_only(_is_static_field_id = false;)
2460 }
2461 
2462 
2463 JNIid* JNIid::find(int offset) {
2464   JNIid* current = this;
2465   while (current != NULL) {
2466     if (current->offset() == offset) return current;
2467     current = current->next();
2468   }
2469   return NULL;
2470 }
2471 
2472 void JNIid::oops_do(OopClosure* f) {
2473   for (JNIid* cur = this; cur != NULL; cur = cur->next()) {
2474     f->do_oop(cur->holder_addr());
2475   }
2476 }
2477 
2478 void JNIid::deallocate(JNIid* current) {
2479   while (current != NULL) {
2480     JNIid* next = current->next();
2481     delete current;
2482     current = next;
2483   }
2484 }
2485 
2486 
2487 void JNIid::verify(klassOop holder) {
2488   int first_field_offset  = instanceMirrorKlass::offset_of_static_fields();
2489   int end_field_offset;
2490   end_field_offset = first_field_offset + (instanceKlass::cast(holder)->static_field_size() * wordSize);
2491 
2492   JNIid* current = this;
2493   while (current != NULL) {
2494     guarantee(current->holder() == holder, "Invalid klass in JNIid");
2495 #ifdef ASSERT
2496     int o = current->offset();
2497     if (current->is_static_field_id()) {
2498       guarantee(o >= first_field_offset  && o < end_field_offset,  "Invalid static field offset in JNIid");
2499     }
2500 #endif
2501     current = current->next();
2502   }
2503 }
2504 
2505 
2506 #ifdef ASSERT
2507 void instanceKlass::set_init_state(ClassState state) {
2508   bool good_state = as_klassOop()->is_shared() ? (_init_state <= state)
2509                                                : (_init_state < state);
2510   assert(good_state || state == allocated, "illegal state transition");
2511   _init_state = state;
2512 }
2513 #endif
2514 
2515 
2516 // RedefineClasses() support for previous versions:
2517 
2518 // Add an information node that contains weak references to the
2519 // interesting parts of the previous version of the_class.
2520 // This is also where we clean out any unused weak references.
2521 // Note that while we delete nodes from the _previous_versions
2522 // array, we never delete the array itself until the klass is
2523 // unloaded. The has_been_redefined() query depends on that fact.
2524 //
2525 void instanceKlass::add_previous_version(instanceKlassHandle ikh,
2526        BitMap* emcp_methods, int emcp_method_count) {
2527   assert(Thread::current()->is_VM_thread(),
2528          "only VMThread can add previous versions");
2529 
2530   if (_previous_versions == NULL) {
2531     // This is the first previous version so make some space.
2532     // Start with 2 elements under the assumption that the class
2533     // won't be redefined much.
2534     _previous_versions =  new (ResourceObj::C_HEAP)
2535                             GrowableArray<PreviousVersionNode *>(2, true);
2536   }
2537 
2538   // RC_TRACE macro has an embedded ResourceMark
2539   RC_TRACE(0x00000100, ("adding previous version ref for %s @%d, EMCP_cnt=%d",
2540     ikh->external_name(), _previous_versions->length(), emcp_method_count));
2541   constantPoolHandle cp_h(ikh->constants());
2542   jobject cp_ref;
2543   if (cp_h->is_shared()) {
2544     // a shared ConstantPool requires a regular reference; a weak
2545     // reference would be collectible
2546     cp_ref = JNIHandles::make_global(cp_h);
2547   } else {
2548     cp_ref = JNIHandles::make_weak_global(cp_h);
2549   }
2550   PreviousVersionNode * pv_node = NULL;
2551   objArrayOop old_methods = ikh->methods();
2552 
2553   if (emcp_method_count == 0) {
2554     // non-shared ConstantPool gets a weak reference
2555     pv_node = new PreviousVersionNode(cp_ref, !cp_h->is_shared(), NULL);
2556     RC_TRACE(0x00000400,
2557       ("add: all methods are obsolete; flushing any EMCP weak refs"));
2558   } else {
2559     int local_count = 0;
2560     GrowableArray<jweak>* method_refs = new (ResourceObj::C_HEAP)
2561       GrowableArray<jweak>(emcp_method_count, true);
2562     for (int i = 0; i < old_methods->length(); i++) {
2563       if (emcp_methods->at(i)) {
2564         // this old method is EMCP so save a weak ref
2565         methodOop old_method = (methodOop) old_methods->obj_at(i);
2566         methodHandle old_method_h(old_method);
2567         jweak method_ref = JNIHandles::make_weak_global(old_method_h);
2568         method_refs->append(method_ref);
2569         if (++local_count >= emcp_method_count) {
2570           // no more EMCP methods so bail out now
2571           break;
2572         }
2573       }
2574     }
2575     // non-shared ConstantPool gets a weak reference
2576     pv_node = new PreviousVersionNode(cp_ref, !cp_h->is_shared(), method_refs);
2577   }
2578 
2579   _previous_versions->append(pv_node);
2580 
2581   // Using weak references allows the interesting parts of previous
2582   // classes to be GC'ed when they are no longer needed. Since the
2583   // caller is the VMThread and we are at a safepoint, this is a good
2584   // time to clear out unused weak references.
2585 
2586   RC_TRACE(0x00000400, ("add: previous version length=%d",
2587     _previous_versions->length()));
2588 
2589   // skip the last entry since we just added it
2590   for (int i = _previous_versions->length() - 2; i >= 0; i--) {
2591     // check the previous versions array for a GC'ed weak refs
2592     pv_node = _previous_versions->at(i);
2593     cp_ref = pv_node->prev_constant_pool();
2594     assert(cp_ref != NULL, "cp ref was unexpectedly cleared");
2595     if (cp_ref == NULL) {
2596       delete pv_node;
2597       _previous_versions->remove_at(i);
2598       // Since we are traversing the array backwards, we don't have to
2599       // do anything special with the index.
2600       continue;  // robustness
2601     }
2602 
2603     constantPoolOop cp = (constantPoolOop)JNIHandles::resolve(cp_ref);
2604     if (cp == NULL) {
2605       // this entry has been GC'ed so remove it
2606       delete pv_node;
2607       _previous_versions->remove_at(i);
2608       // Since we are traversing the array backwards, we don't have to
2609       // do anything special with the index.
2610       continue;
2611     } else {
2612       RC_TRACE(0x00000400, ("add: previous version @%d is alive", i));
2613     }
2614 
2615     GrowableArray<jweak>* method_refs = pv_node->prev_EMCP_methods();
2616     if (method_refs != NULL) {
2617       RC_TRACE(0x00000400, ("add: previous methods length=%d",
2618         method_refs->length()));
2619       for (int j = method_refs->length() - 1; j >= 0; j--) {
2620         jweak method_ref = method_refs->at(j);
2621         assert(method_ref != NULL, "weak method ref was unexpectedly cleared");
2622         if (method_ref == NULL) {
2623           method_refs->remove_at(j);
2624           // Since we are traversing the array backwards, we don't have to
2625           // do anything special with the index.
2626           continue;  // robustness
2627         }
2628 
2629         methodOop method = (methodOop)JNIHandles::resolve(method_ref);
2630         if (method == NULL || emcp_method_count == 0) {
2631           // This method entry has been GC'ed or the current
2632           // RedefineClasses() call has made all methods obsolete
2633           // so remove it.
2634           JNIHandles::destroy_weak_global(method_ref);
2635           method_refs->remove_at(j);
2636         } else {
2637           // RC_TRACE macro has an embedded ResourceMark
2638           RC_TRACE(0x00000400,
2639             ("add: %s(%s): previous method @%d in version @%d is alive",
2640             method->name()->as_C_string(), method->signature()->as_C_string(),
2641             j, i));
2642         }
2643       }
2644     }
2645   }
2646 
2647   int obsolete_method_count = old_methods->length() - emcp_method_count;
2648 
2649   if (emcp_method_count != 0 && obsolete_method_count != 0 &&
2650       _previous_versions->length() > 1) {
2651     // We have a mix of obsolete and EMCP methods. If there is more
2652     // than the previous version that we just added, then we have to
2653     // clear out any matching EMCP method entries the hard way.
2654     int local_count = 0;
2655     for (int i = 0; i < old_methods->length(); i++) {
2656       if (!emcp_methods->at(i)) {
2657         // only obsolete methods are interesting
2658         methodOop old_method = (methodOop) old_methods->obj_at(i);
2659         Symbol* m_name = old_method->name();
2660         Symbol* m_signature = old_method->signature();
2661 
2662         // skip the last entry since we just added it
2663         for (int j = _previous_versions->length() - 2; j >= 0; j--) {
2664           // check the previous versions array for a GC'ed weak refs
2665           pv_node = _previous_versions->at(j);
2666           cp_ref = pv_node->prev_constant_pool();
2667           assert(cp_ref != NULL, "cp ref was unexpectedly cleared");
2668           if (cp_ref == NULL) {
2669             delete pv_node;
2670             _previous_versions->remove_at(j);
2671             // Since we are traversing the array backwards, we don't have to
2672             // do anything special with the index.
2673             continue;  // robustness
2674           }
2675 
2676           constantPoolOop cp = (constantPoolOop)JNIHandles::resolve(cp_ref);
2677           if (cp == NULL) {
2678             // this entry has been GC'ed so remove it
2679             delete pv_node;
2680             _previous_versions->remove_at(j);
2681             // Since we are traversing the array backwards, we don't have to
2682             // do anything special with the index.
2683             continue;
2684           }
2685 
2686           GrowableArray<jweak>* method_refs = pv_node->prev_EMCP_methods();
2687           if (method_refs == NULL) {
2688             // We have run into a PreviousVersion generation where
2689             // all methods were made obsolete during that generation's
2690             // RedefineClasses() operation. At the time of that
2691             // operation, all EMCP methods were flushed so we don't
2692             // have to go back any further.
2693             //
2694             // A NULL method_refs is different than an empty method_refs.
2695             // We cannot infer any optimizations about older generations
2696             // from an empty method_refs for the current generation.
2697             break;
2698           }
2699 
2700           for (int k = method_refs->length() - 1; k >= 0; k--) {
2701             jweak method_ref = method_refs->at(k);
2702             assert(method_ref != NULL,
2703               "weak method ref was unexpectedly cleared");
2704             if (method_ref == NULL) {
2705               method_refs->remove_at(k);
2706               // Since we are traversing the array backwards, we don't
2707               // have to do anything special with the index.
2708               continue;  // robustness
2709             }
2710 
2711             methodOop method = (methodOop)JNIHandles::resolve(method_ref);
2712             if (method == NULL) {
2713               // this method entry has been GC'ed so skip it
2714               JNIHandles::destroy_weak_global(method_ref);
2715               method_refs->remove_at(k);
2716               continue;
2717             }
2718 
2719             if (method->name() == m_name &&
2720                 method->signature() == m_signature) {
2721               // The current RedefineClasses() call has made all EMCP
2722               // versions of this method obsolete so mark it as obsolete
2723               // and remove the weak ref.
2724               RC_TRACE(0x00000400,
2725                 ("add: %s(%s): flush obsolete method @%d in version @%d",
2726                 m_name->as_C_string(), m_signature->as_C_string(), k, j));
2727 
2728               method->set_is_obsolete();
2729               JNIHandles::destroy_weak_global(method_ref);
2730               method_refs->remove_at(k);
2731               break;
2732             }
2733           }
2734 
2735           // The previous loop may not find a matching EMCP method, but
2736           // that doesn't mean that we can optimize and not go any
2737           // further back in the PreviousVersion generations. The EMCP
2738           // method for this generation could have already been GC'ed,
2739           // but there still may be an older EMCP method that has not
2740           // been GC'ed.
2741         }
2742 
2743         if (++local_count >= obsolete_method_count) {
2744           // no more obsolete methods so bail out now
2745           break;
2746         }
2747       }
2748     }
2749   }
2750 } // end add_previous_version()
2751 
2752 
2753 // Determine if instanceKlass has a previous version.
2754 bool instanceKlass::has_previous_version() const {
2755   if (_previous_versions == NULL) {
2756     // no previous versions array so answer is easy
2757     return false;
2758   }
2759 
2760   for (int i = _previous_versions->length() - 1; i >= 0; i--) {
2761     // Check the previous versions array for an info node that hasn't
2762     // been GC'ed
2763     PreviousVersionNode * pv_node = _previous_versions->at(i);
2764 
2765     jobject cp_ref = pv_node->prev_constant_pool();
2766     assert(cp_ref != NULL, "cp reference was unexpectedly cleared");
2767     if (cp_ref == NULL) {
2768       continue;  // robustness
2769     }
2770 
2771     constantPoolOop cp = (constantPoolOop)JNIHandles::resolve(cp_ref);
2772     if (cp != NULL) {
2773       // we have at least one previous version
2774       return true;
2775     }
2776 
2777     // We don't have to check the method refs. If the constant pool has
2778     // been GC'ed then so have the methods.
2779   }
2780 
2781   // all of the underlying nodes' info has been GC'ed
2782   return false;
2783 } // end has_previous_version()
2784 
2785 methodOop instanceKlass::method_with_idnum(int idnum) {
2786   methodOop m = NULL;
2787   if (idnum < methods()->length()) {
2788     m = (methodOop) methods()->obj_at(idnum);
2789   }
2790   if (m == NULL || m->method_idnum() != idnum) {
2791     for (int index = 0; index < methods()->length(); ++index) {
2792       m = (methodOop) methods()->obj_at(index);
2793       if (m->method_idnum() == idnum) {
2794         return m;
2795       }
2796     }
2797   }
2798   return m;
2799 }
2800 
2801 
2802 // Set the annotation at 'idnum' to 'anno'.
2803 // We don't want to create or extend the array if 'anno' is NULL, since that is the
2804 // default value.  However, if the array exists and is long enough, we must set NULL values.
2805 void instanceKlass::set_methods_annotations_of(int idnum, typeArrayOop anno, objArrayOop* md_p) {
2806   objArrayOop md = *md_p;
2807   if (md != NULL && md->length() > idnum) {
2808     md->obj_at_put(idnum, anno);
2809   } else if (anno != NULL) {
2810     // create the array
2811     int length = MAX2(idnum+1, (int)_idnum_allocated_count);
2812     md = oopFactory::new_system_objArray(length, Thread::current());
2813     if (*md_p != NULL) {
2814       // copy the existing entries
2815       for (int index = 0; index < (*md_p)->length(); index++) {
2816         md->obj_at_put(index, (*md_p)->obj_at(index));
2817       }
2818     }
2819     set_annotations(md, md_p);
2820     md->obj_at_put(idnum, anno);
2821   } // if no array and idnum isn't included there is nothing to do
2822 }
2823 
2824 // Construct a PreviousVersionNode entry for the array hung off
2825 // the instanceKlass.
2826 PreviousVersionNode::PreviousVersionNode(jobject prev_constant_pool,
2827   bool prev_cp_is_weak, GrowableArray<jweak>* prev_EMCP_methods) {
2828 
2829   _prev_constant_pool = prev_constant_pool;
2830   _prev_cp_is_weak = prev_cp_is_weak;
2831   _prev_EMCP_methods = prev_EMCP_methods;
2832 }
2833 
2834 
2835 // Destroy a PreviousVersionNode
2836 PreviousVersionNode::~PreviousVersionNode() {
2837   if (_prev_constant_pool != NULL) {
2838     if (_prev_cp_is_weak) {
2839       JNIHandles::destroy_weak_global(_prev_constant_pool);
2840     } else {
2841       JNIHandles::destroy_global(_prev_constant_pool);
2842     }
2843   }
2844 
2845   if (_prev_EMCP_methods != NULL) {
2846     for (int i = _prev_EMCP_methods->length() - 1; i >= 0; i--) {
2847       jweak method_ref = _prev_EMCP_methods->at(i);
2848       if (method_ref != NULL) {
2849         JNIHandles::destroy_weak_global(method_ref);
2850       }
2851     }
2852     delete _prev_EMCP_methods;
2853   }
2854 }
2855 
2856 
2857 // Construct a PreviousVersionInfo entry
2858 PreviousVersionInfo::PreviousVersionInfo(PreviousVersionNode *pv_node) {
2859   _prev_constant_pool_handle = constantPoolHandle();  // NULL handle
2860   _prev_EMCP_method_handles = NULL;
2861 
2862   jobject cp_ref = pv_node->prev_constant_pool();
2863   assert(cp_ref != NULL, "constant pool ref was unexpectedly cleared");
2864   if (cp_ref == NULL) {
2865     return;  // robustness
2866   }
2867 
2868   constantPoolOop cp = (constantPoolOop)JNIHandles::resolve(cp_ref);
2869   if (cp == NULL) {
2870     // Weak reference has been GC'ed. Since the constant pool has been
2871     // GC'ed, the methods have also been GC'ed.
2872     return;
2873   }
2874 
2875   // make the constantPoolOop safe to return
2876   _prev_constant_pool_handle = constantPoolHandle(cp);
2877 
2878   GrowableArray<jweak>* method_refs = pv_node->prev_EMCP_methods();
2879   if (method_refs == NULL) {
2880     // the instanceKlass did not have any EMCP methods
2881     return;
2882   }
2883 
2884   _prev_EMCP_method_handles = new GrowableArray<methodHandle>(10);
2885 
2886   int n_methods = method_refs->length();
2887   for (int i = 0; i < n_methods; i++) {
2888     jweak method_ref = method_refs->at(i);
2889     assert(method_ref != NULL, "weak method ref was unexpectedly cleared");
2890     if (method_ref == NULL) {
2891       continue;  // robustness
2892     }
2893 
2894     methodOop method = (methodOop)JNIHandles::resolve(method_ref);
2895     if (method == NULL) {
2896       // this entry has been GC'ed so skip it
2897       continue;
2898     }
2899 
2900     // make the methodOop safe to return
2901     _prev_EMCP_method_handles->append(methodHandle(method));
2902   }
2903 }
2904 
2905 
2906 // Destroy a PreviousVersionInfo
2907 PreviousVersionInfo::~PreviousVersionInfo() {
2908   // Since _prev_EMCP_method_handles is not C-heap allocated, we
2909   // don't have to delete it.
2910 }
2911 
2912 
2913 // Construct a helper for walking the previous versions array
2914 PreviousVersionWalker::PreviousVersionWalker(instanceKlass *ik) {
2915   _previous_versions = ik->previous_versions();
2916   _current_index = 0;
2917   // _hm needs no initialization
2918   _current_p = NULL;
2919 }
2920 
2921 
2922 // Destroy a PreviousVersionWalker
2923 PreviousVersionWalker::~PreviousVersionWalker() {
2924   // Delete the current info just in case the caller didn't walk to
2925   // the end of the previous versions list. No harm if _current_p is
2926   // already NULL.
2927   delete _current_p;
2928 
2929   // When _hm is destroyed, all the Handles returned in
2930   // PreviousVersionInfo objects will be destroyed.
2931   // Also, after this destructor is finished it will be
2932   // safe to delete the GrowableArray allocated in the
2933   // PreviousVersionInfo objects.
2934 }
2935 
2936 
2937 // Return the interesting information for the next previous version
2938 // of the klass. Returns NULL if there are no more previous versions.
2939 PreviousVersionInfo* PreviousVersionWalker::next_previous_version() {
2940   if (_previous_versions == NULL) {
2941     // no previous versions so nothing to return
2942     return NULL;
2943   }
2944 
2945   delete _current_p;  // cleanup the previous info for the caller
2946   _current_p = NULL;  // reset to NULL so we don't delete same object twice
2947 
2948   int length = _previous_versions->length();
2949 
2950   while (_current_index < length) {
2951     PreviousVersionNode * pv_node = _previous_versions->at(_current_index++);
2952     PreviousVersionInfo * pv_info = new (ResourceObj::C_HEAP)
2953                                           PreviousVersionInfo(pv_node);
2954 
2955     constantPoolHandle cp_h = pv_info->prev_constant_pool_handle();
2956     if (cp_h.is_null()) {
2957       delete pv_info;
2958 
2959       // The underlying node's info has been GC'ed so try the next one.
2960       // We don't have to check the methods. If the constant pool has
2961       // GC'ed then so have the methods.
2962       continue;
2963     }
2964 
2965     // Found a node with non GC'ed info so return it. The caller will
2966     // need to delete pv_info when they are done with it.
2967     _current_p = pv_info;
2968     return pv_info;
2969   }
2970 
2971   // all of the underlying nodes' info has been GC'ed
2972   return NULL;
2973 } // end next_previous_version()
--- EOF ---