1 /*
   2  * Copyright (c) 1997, 2014, 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/classLoader.hpp"
  27 #include "classfile/stringTable.hpp"
  28 #include "classfile/systemDictionary.hpp"
  29 #include "code/codeCache.hpp"
  30 #include "compiler/compileBroker.hpp"
  31 #include "compiler/compilerOracle.hpp"
  32 #include "interpreter/bytecodeHistogram.hpp"
  33 #include "memory/genCollectedHeap.hpp"
  34 #include "memory/oopFactory.hpp"
  35 #include "memory/universe.hpp"
  36 #include "oops/constantPool.hpp"
  37 #include "oops/generateOopMap.hpp"
  38 #include "oops/instanceKlass.hpp"
  39 #include "oops/instanceOop.hpp"
  40 #include "oops/method.hpp"
  41 #include "oops/objArrayOop.hpp"
  42 #include "oops/oop.inline.hpp"
  43 #include "oops/symbol.hpp"
  44 #include "prims/jvmtiExport.hpp"
  45 #include "runtime/arguments.hpp"
  46 #include "runtime/biasedLocking.hpp"
  47 #include "runtime/compilationPolicy.hpp"
  48 #include "runtime/fprofiler.hpp"
  49 #include "runtime/init.hpp"
  50 #include "runtime/interfaceSupport.hpp"
  51 #include "runtime/java.hpp"
  52 #include "runtime/memprofiler.hpp"
  53 #include "runtime/sharedRuntime.hpp"
  54 #include "runtime/statSampler.hpp"
  55 #include "runtime/sweeper.hpp"
  56 #include "runtime/task.hpp"
  57 #include "runtime/thread.inline.hpp"
  58 #include "runtime/timer.hpp"
  59 #include "runtime/vm_operations.hpp"
  60 #include "services/memTracker.hpp"
  61 #include "trace/tracing.hpp"
  62 #include "utilities/dtrace.hpp"
  63 #include "utilities/globalDefinitions.hpp"
  64 #include "utilities/histogram.hpp"
  65 #include "utilities/macros.hpp"
  66 #include "utilities/vmError.hpp"
  67 #if INCLUDE_ALL_GCS
  68 #include "gc_implementation/concurrentMarkSweep/concurrentMarkSweepThread.hpp"
  69 #include "gc_implementation/parallelScavenge/psScavenge.hpp"
  70 #endif // INCLUDE_ALL_GCS
  71 #ifdef COMPILER1
  72 #include "c1/c1_Compiler.hpp"
  73 #include "c1/c1_Runtime1.hpp"
  74 #endif
  75 #ifdef COMPILER2
  76 #include "code/compiledIC.hpp"
  77 #include "compiler/methodLiveness.hpp"
  78 #include "opto/compile.hpp"
  79 #include "opto/indexSet.hpp"
  80 #include "opto/runtime.hpp"
  81 #endif
  82 
  83 PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC
  84 
  85 GrowableArray<Method*>* collected_profiled_methods;
  86 
  87 int compare_methods(Method** a, Method** b) {
  88   // %%% there can be 32-bit overflow here
  89   return ((*b)->invocation_count() + (*b)->compiled_invocation_count())
  90        - ((*a)->invocation_count() + (*a)->compiled_invocation_count());
  91 }
  92 
  93 void collect_profiled_methods(Method* m) {
  94   Thread* thread = Thread::current();
  95   // This HandleMark prevents a huge amount of handles from being added
  96   // to the metadata_handles() array on the thread.
  97   HandleMark hm(thread);
  98   methodHandle mh(thread, m);
  99   if ((m->method_data() != NULL) &&
 100       (PrintMethodData || CompilerOracle::should_print(mh))) {
 101     collected_profiled_methods->push(m);
 102   }
 103 }
 104 
 105 void print_method_profiling_data() {
 106   if (ProfileInterpreter COMPILER1_PRESENT(|| C1UpdateMethodData) &&
 107      (PrintMethodData || CompilerOracle::should_print_methods())) {
 108     ResourceMark rm;
 109     HandleMark hm;
 110     collected_profiled_methods = new GrowableArray<Method*>(1024);
 111     ClassLoaderDataGraph::methods_do(collect_profiled_methods);
 112     collected_profiled_methods->sort(&compare_methods);
 113 
 114     int count = collected_profiled_methods->length();
 115     int total_size = 0;
 116     if (count > 0) {
 117       for (int index = 0; index < count; index++) {
 118         Method* m = collected_profiled_methods->at(index);
 119         ttyLocker ttyl;
 120         tty->print_cr("------------------------------------------------------------------------");
 121         m->print_invocation_count();
 122         tty->print_cr("  mdo size: %d bytes", m->method_data()->size_in_bytes());
 123         tty->cr();
 124         // Dump data on parameters if any
 125         if (m->method_data() != NULL && m->method_data()->parameters_type_data() != NULL) {
 126           tty->fill_to(2);
 127           m->method_data()->parameters_type_data()->print_data_on(tty);
 128         }
 129         m->print_codes();
 130         total_size += m->method_data()->size_in_bytes();
 131       }
 132       tty->print_cr("------------------------------------------------------------------------");
 133       tty->print_cr("Total MDO size: %d bytes", total_size);
 134     }
 135   }
 136 }
 137 
 138 
 139 #ifndef PRODUCT
 140 
 141 // Statistics printing (method invocation histogram)
 142 
 143 GrowableArray<Method*>* collected_invoked_methods;
 144 
 145 void collect_invoked_methods(Method* m) {
 146   if (m->invocation_count() + m->compiled_invocation_count() >= 1 ) {
 147     collected_invoked_methods->push(m);
 148   }
 149 }
 150 
 151 
 152 
 153 
 154 void print_method_invocation_histogram() {
 155   ResourceMark rm;
 156   HandleMark hm;
 157   collected_invoked_methods = new GrowableArray<Method*>(1024);
 158   SystemDictionary::methods_do(collect_invoked_methods);
 159   collected_invoked_methods->sort(&compare_methods);
 160   //
 161   tty->cr();
 162   tty->print_cr("Histogram Over MethodOop Invocation Counters (cutoff = %d):", MethodHistogramCutoff);
 163   tty->cr();
 164   tty->print_cr("____Count_(I+C)____Method________________________Module_________________");
 165   unsigned total = 0, int_total = 0, comp_total = 0, static_total = 0, final_total = 0,
 166       synch_total = 0, nativ_total = 0, acces_total = 0;
 167   for (int index = 0; index < collected_invoked_methods->length(); index++) {
 168     Method* m = collected_invoked_methods->at(index);
 169     int c = m->invocation_count() + m->compiled_invocation_count();
 170     if (c >= MethodHistogramCutoff) m->print_invocation_count();
 171     int_total  += m->invocation_count();
 172     comp_total += m->compiled_invocation_count();
 173     if (m->is_final())        final_total  += c;
 174     if (m->is_static())       static_total += c;
 175     if (m->is_synchronized()) synch_total  += c;
 176     if (m->is_native())       nativ_total  += c;
 177     if (m->is_accessor())     acces_total  += c;
 178   }
 179   tty->cr();
 180   total = int_total + comp_total;
 181   tty->print_cr("Invocations summary:");
 182   tty->print_cr("\t%9d (%4.1f%%) interpreted",  int_total,    100.0 * int_total    / total);
 183   tty->print_cr("\t%9d (%4.1f%%) compiled",     comp_total,   100.0 * comp_total   / total);
 184   tty->print_cr("\t%9d (100%%)  total",         total);
 185   tty->print_cr("\t%9d (%4.1f%%) synchronized", synch_total,  100.0 * synch_total  / total);
 186   tty->print_cr("\t%9d (%4.1f%%) final",        final_total,  100.0 * final_total  / total);
 187   tty->print_cr("\t%9d (%4.1f%%) static",       static_total, 100.0 * static_total / total);
 188   tty->print_cr("\t%9d (%4.1f%%) native",       nativ_total,  100.0 * nativ_total  / total);
 189   tty->print_cr("\t%9d (%4.1f%%) accessor",     acces_total,  100.0 * acces_total  / total);
 190   tty->cr();
 191   SharedRuntime::print_call_statistics(comp_total);
 192 }
 193 
 194 void print_bytecode_count() {
 195   if (CountBytecodes || TraceBytecodes || StopInterpreterAt) {
 196     tty->print_cr("[BytecodeCounter::counter_value = %d]", BytecodeCounter::counter_value());
 197   }
 198 }
 199 
 200 AllocStats alloc_stats;
 201 
 202 
 203 
 204 // General statistics printing (profiling ...)
 205 void print_statistics() {
 206 #ifdef ASSERT
 207 
 208   if (CountRuntimeCalls) {
 209     extern Histogram *RuntimeHistogram;
 210     RuntimeHistogram->print();
 211   }
 212 
 213   if (CountJNICalls) {
 214     extern Histogram *JNIHistogram;
 215     JNIHistogram->print();
 216   }
 217 
 218   if (CountJVMCalls) {
 219     extern Histogram *JVMHistogram;
 220     JVMHistogram->print();
 221   }
 222 
 223 #endif
 224 
 225   if (MemProfiling) {
 226     MemProfiler::disengage();
 227   }
 228 
 229   if (CITime) {
 230     CompileBroker::print_times();
 231   }
 232 
 233 #ifdef COMPILER1
 234   if ((PrintC1Statistics || LogVMOutput || LogCompilation) && UseCompiler) {
 235     FlagSetting fs(DisplayVMOutput, DisplayVMOutput && PrintC1Statistics);
 236     Runtime1::print_statistics();
 237     Deoptimization::print_statistics();
 238     SharedRuntime::print_statistics();
 239     nmethod::print_statistics();
 240   }
 241 #endif /* COMPILER1 */
 242 
 243 #ifdef COMPILER2
 244   if ((PrintOptoStatistics || LogVMOutput || LogCompilation) && UseCompiler) {
 245     FlagSetting fs(DisplayVMOutput, DisplayVMOutput && PrintOptoStatistics);
 246     Compile::print_statistics();
 247 #ifndef COMPILER1
 248     Deoptimization::print_statistics();
 249     nmethod::print_statistics();
 250     SharedRuntime::print_statistics();
 251 #endif //COMPILER1
 252     os::print_statistics();
 253   }
 254 
 255   if (PrintLockStatistics || PrintPreciseBiasedLockingStatistics || PrintPreciseRTMLockingStatistics) {
 256     OptoRuntime::print_named_counters();
 257   }
 258 
 259   if (TimeLivenessAnalysis) {
 260     MethodLiveness::print_times();
 261   }
 262 #ifdef ASSERT
 263   if (CollectIndexSetStatistics) {
 264     IndexSet::print_statistics();
 265   }
 266 #endif // ASSERT
 267 #endif // COMPILER2
 268   if (CountCompiledCalls) {
 269     print_method_invocation_histogram();
 270   }
 271 
 272   print_method_profiling_data();
 273 
 274   if (TimeCompilationPolicy) {
 275     CompilationPolicy::policy()->print_time();
 276   }
 277   if (TimeOopMap) {
 278     GenerateOopMap::print_time();
 279   }
 280   if (ProfilerCheckIntervals) {
 281     PeriodicTask::print_intervals();
 282   }
 283   if (PrintSymbolTableSizeHistogram) {
 284     SymbolTable::print_histogram();
 285   }
 286   if (CountBytecodes || TraceBytecodes || StopInterpreterAt) {
 287     BytecodeCounter::print();
 288   }
 289   if (PrintBytecodePairHistogram) {
 290     BytecodePairHistogram::print();
 291   }
 292 
 293   if (PrintCodeCache) {
 294     MutexLockerEx mu(CodeCache_lock, Mutex::_no_safepoint_check_flag);
 295     CodeCache::print();
 296   }
 297 
 298   if (PrintMethodFlushingStatistics) {
 299     NMethodSweeper::print();
 300   }
 301 
 302   if (PrintCodeCache2) {
 303     MutexLockerEx mu(CodeCache_lock, Mutex::_no_safepoint_check_flag);
 304     CodeCache::print_internals();
 305   }
 306 
 307   if (PrintClassStatistics) {
 308     SystemDictionary::print_class_statistics();
 309   }
 310   if (PrintMethodStatistics) {
 311     SystemDictionary::print_method_statistics();
 312   }
 313 
 314   if (PrintVtableStats) {
 315     klassVtable::print_statistics();
 316     klassItable::print_statistics();
 317   }
 318   if (VerifyOops) {
 319     tty->print_cr("+VerifyOops count: %d", StubRoutines::verify_oop_count());
 320   }
 321 
 322   print_bytecode_count();
 323   if (PrintMallocStatistics) {
 324     tty->print("allocation stats: ");
 325     alloc_stats.print();
 326     tty->cr();
 327   }
 328 
 329   if (PrintSystemDictionaryAtExit) {
 330     SystemDictionary::print();
 331   }
 332 
 333   if (PrintBiasedLockingStatistics) {
 334     BiasedLocking::print_counters();
 335   }
 336 
 337 #ifdef ENABLE_ZAP_DEAD_LOCALS
 338 #ifdef COMPILER2
 339   if (ZapDeadCompiledLocals) {
 340     tty->print_cr("Compile::CompiledZap_count = %d", Compile::CompiledZap_count);
 341     tty->print_cr("OptoRuntime::ZapDeadCompiledLocals_count = %d", OptoRuntime::ZapDeadCompiledLocals_count);
 342   }
 343 #endif // COMPILER2
 344 #endif // ENABLE_ZAP_DEAD_LOCALS
 345   // Native memory tracking data
 346   if (PrintNMTStatistics) {
 347     MemTracker::final_report(tty);
 348   }
 349 }
 350 
 351 #else // PRODUCT MODE STATISTICS
 352 
 353 void print_statistics() {
 354 
 355   if (PrintMethodData) {
 356     print_method_profiling_data();
 357   }
 358 
 359   if (CITime) {
 360     CompileBroker::print_times();
 361   }
 362 
 363   if (PrintCodeCache) {
 364     MutexLockerEx mu(CodeCache_lock, Mutex::_no_safepoint_check_flag);
 365     CodeCache::print();
 366   }
 367 
 368   if (PrintMethodFlushingStatistics) {
 369     NMethodSweeper::print();
 370   }
 371 
 372 #ifdef COMPILER2
 373   if (PrintPreciseBiasedLockingStatistics || PrintPreciseRTMLockingStatistics) {
 374     OptoRuntime::print_named_counters();
 375   }
 376 #endif
 377   if (PrintBiasedLockingStatistics) {
 378     BiasedLocking::print_counters();
 379   }
 380 
 381   // Native memory tracking data
 382   if (PrintNMTStatistics) {
 383     MemTracker::final_report(tty);
 384   }
 385 }
 386 
 387 #endif
 388 
 389 // Note: before_exit() can be executed only once, if more than one threads
 390 //       are trying to shutdown the VM at the same time, only one thread
 391 //       can run before_exit() and all other threads must wait.
 392 void before_exit(JavaThread * thread) {
 393   #define BEFORE_EXIT_NOT_RUN 0
 394   #define BEFORE_EXIT_RUNNING 1
 395   #define BEFORE_EXIT_DONE    2
 396   static jint volatile _before_exit_status = BEFORE_EXIT_NOT_RUN;
 397 
 398   // Note: don't use a Mutex to guard the entire before_exit(), as
 399   // JVMTI post_thread_end_event and post_vm_death_event will run native code.
 400   // A CAS or OSMutex would work just fine but then we need to manipulate
 401   // thread state for Safepoint. Here we use Monitor wait() and notify_all()
 402   // for synchronization.
 403   { MutexLocker ml(BeforeExit_lock);
 404     switch (_before_exit_status) {
 405     case BEFORE_EXIT_NOT_RUN:
 406       _before_exit_status = BEFORE_EXIT_RUNNING;
 407       break;
 408     case BEFORE_EXIT_RUNNING:
 409       while (_before_exit_status == BEFORE_EXIT_RUNNING) {
 410         BeforeExit_lock->wait();
 411       }
 412       assert(_before_exit_status == BEFORE_EXIT_DONE, "invalid state");
 413       return;
 414     case BEFORE_EXIT_DONE:
 415       return;
 416     }
 417   }
 418 
 419   // Hang forever on exit if we're reporting an error.
 420   if (ShowMessageBoxOnError && is_error_reported()) {
 421     os::infinite_sleep();
 422   }
 423 
 424   // Terminate watcher thread - must before disenrolling any periodic task
 425   if (PeriodicTask::num_tasks() > 0)
 426     WatcherThread::stop();
 427 
 428   // Print statistics gathered (profiling ...)
 429   if (Arguments::has_profile()) {
 430     FlatProfiler::disengage();
 431     FlatProfiler::print(10);
 432   }
 433 
 434   // shut down the StatSampler task
 435   StatSampler::disengage();
 436   StatSampler::destroy();
 437 
 438   // Stop concurrent GC threads
 439   Universe::heap()->stop();
 440 
 441   // Print GC/heap related information.
 442   if (PrintGCDetails) {
 443     Universe::print();
 444     AdaptiveSizePolicyOutput(0);
 445     if (Verbose) {
 446       ClassLoaderDataGraph::dump_on(gclog_or_tty);
 447     }
 448   }
 449 
 450   if (PrintBytecodeHistogram) {
 451     BytecodeHistogram::print();
 452   }
 453 
 454   if (JvmtiExport::should_post_thread_life()) {
 455     JvmtiExport::post_thread_end(thread);
 456   }
 457 
 458 
 459   EventThreadEnd event;
 460   if (event.should_commit()) {
 461       event.set_javalangthread(java_lang_Thread::thread_id(thread->threadObj()));
 462       event.commit();
 463   }
 464 
 465   // Always call even when there are not JVMTI environments yet, since environments
 466   // may be attached late and JVMTI must track phases of VM execution
 467   JvmtiExport::post_vm_death();
 468   Threads::shutdown_vm_agents();
 469 
 470   // Terminate the signal thread
 471   // Note: we don't wait until it actually dies.
 472   os::terminate_signal_thread();
 473 
 474   print_statistics();
 475   Universe::heap()->print_tracing_info();
 476 
 477   { MutexLocker ml(BeforeExit_lock);
 478     _before_exit_status = BEFORE_EXIT_DONE;
 479     BeforeExit_lock->notify_all();
 480   }
 481 
 482   if (VerifyStringTableAtExit) {
 483     int fail_cnt = 0;
 484     {
 485       MutexLocker ml(StringTable_lock);
 486       fail_cnt = StringTable::verify_and_compare_entries();
 487     }
 488 
 489     if (fail_cnt != 0) {
 490       tty->print_cr("ERROR: fail_cnt=%d", fail_cnt);
 491       guarantee(fail_cnt == 0, "unexpected StringTable verification failures");
 492     }
 493   }
 494 
 495   #undef BEFORE_EXIT_NOT_RUN
 496   #undef BEFORE_EXIT_RUNNING
 497   #undef BEFORE_EXIT_DONE
 498 }
 499 
 500 void vm_exit(int code) {
 501   Thread* thread = ThreadLocalStorage::is_initialized() ?
 502     ThreadLocalStorage::get_thread_slow() : NULL;
 503   if (thread == NULL) {
 504     // we have serious problems -- just exit
 505     vm_direct_exit(code);
 506   }
 507 
 508   if (VMThread::vm_thread() != NULL) {
 509     // Fire off a VM_Exit operation to bring VM to a safepoint and exit
 510     VM_Exit op(code);
 511     if (thread->is_Java_thread())
 512       ((JavaThread*)thread)->set_thread_state(_thread_in_vm);
 513     VMThread::execute(&op);
 514     // should never reach here; but in case something wrong with VM Thread.
 515     vm_direct_exit(code);
 516   } else {
 517     // VM thread is gone, just exit
 518     vm_direct_exit(code);
 519   }
 520   ShouldNotReachHere();
 521 }
 522 
 523 void notify_vm_shutdown() {
 524   // For now, just a dtrace probe.
 525   HOTSPOT_VM_SHUTDOWN();
 526   HS_DTRACE_WORKAROUND_TAIL_CALL_BUG();
 527 }
 528 
 529 void vm_direct_exit(int code) {
 530   notify_vm_shutdown();
 531   os::wait_for_keypress_at_exit();
 532   os::exit(code);
 533 }
 534 
 535 void vm_perform_shutdown_actions() {
 536   // Warning: do not call 'exit_globals()' here. All threads are still running.
 537   // Calling 'exit_globals()' will disable thread-local-storage and cause all
 538   // kinds of assertions to trigger in debug mode.
 539   if (is_init_completed()) {
 540     Thread* thread = ThreadLocalStorage::is_initialized() ?
 541                      ThreadLocalStorage::get_thread_slow() : NULL;
 542     if (thread != NULL && thread->is_Java_thread()) {
 543       // We are leaving the VM, set state to native (in case any OS exit
 544       // handlers call back to the VM)
 545       JavaThread* jt = (JavaThread*)thread;
 546       // Must always be walkable or have no last_Java_frame when in
 547       // thread_in_native
 548       jt->frame_anchor()->make_walkable(jt);
 549       jt->set_thread_state(_thread_in_native);
 550     }
 551   }
 552   notify_vm_shutdown();
 553 }
 554 
 555 void vm_shutdown()
 556 {
 557   vm_perform_shutdown_actions();
 558   os::wait_for_keypress_at_exit();
 559   os::shutdown();
 560 }
 561 
 562 void vm_abort(bool dump_core) {
 563   vm_perform_shutdown_actions();
 564   os::wait_for_keypress_at_exit();
 565   os::abort(dump_core);
 566   ShouldNotReachHere();
 567 }
 568 
 569 void vm_notify_during_shutdown(const char* error, const char* message) {
 570   if (error != NULL) {
 571     tty->print_cr("Error occurred during initialization of VM");
 572     tty->print("%s", error);
 573     if (message != NULL) {
 574       tty->print_cr(": %s", message);
 575     }
 576     else {
 577       tty->cr();
 578     }
 579   }
 580   if (ShowMessageBoxOnError && WizardMode) {
 581     fatal("Error occurred during initialization of VM");
 582   }
 583 }
 584 
 585 void vm_exit_during_initialization(Handle exception) {
 586   tty->print_cr("Error occurred during initialization of VM");
 587   // If there are exceptions on this thread it must be cleared
 588   // first and here. Any future calls to EXCEPTION_MARK requires
 589   // that no pending exceptions exist.
 590   Thread *THREAD = Thread::current();
 591   if (HAS_PENDING_EXCEPTION) {
 592     CLEAR_PENDING_EXCEPTION;
 593   }
 594   java_lang_Throwable::print(exception, tty);
 595   tty->cr();
 596   java_lang_Throwable::print_stack_trace(exception(), tty);
 597   tty->cr();
 598   vm_notify_during_shutdown(NULL, NULL);
 599 
 600   // Failure during initialization, we don't want to dump core
 601   vm_abort(false);
 602 }
 603 
 604 void vm_exit_during_initialization(Symbol* ex, const char* message) {
 605   ResourceMark rm;
 606   vm_notify_during_shutdown(ex->as_C_string(), message);
 607 
 608   // Failure during initialization, we don't want to dump core
 609   vm_abort(false);
 610 }
 611 
 612 void vm_exit_during_initialization(const char* error, const char* message) {
 613   vm_notify_during_shutdown(error, message);
 614 
 615   // Failure during initialization, we don't want to dump core
 616   vm_abort(false);
 617 }
 618 
 619 void vm_shutdown_during_initialization(const char* error, const char* message) {
 620   vm_notify_during_shutdown(error, message);
 621   vm_shutdown();
 622 }
 623 
 624 JDK_Version JDK_Version::_current;
 625 const char* JDK_Version::_runtime_name;
 626 const char* JDK_Version::_runtime_version;
 627 
 628 void JDK_Version::initialize() {
 629   jdk_version_info info;
 630   assert(!_current.is_valid(), "Don't initialize twice");
 631 
 632   void *lib_handle = os::native_java_library();
 633   jdk_version_info_fn_t func = CAST_TO_FN_PTR(jdk_version_info_fn_t,
 634      os::dll_lookup(lib_handle, "JDK_GetVersionInfo0"));
 635 
 636   if (func == NULL) {
 637     // JDK older than 1.6
 638     _current._partially_initialized = true;
 639   } else {
 640     (*func)(&info, sizeof(info));
 641 
 642     int major = JDK_VERSION_MAJOR(info.jdk_version);
 643     int minor = JDK_VERSION_MINOR(info.jdk_version);
 644     int micro = JDK_VERSION_MICRO(info.jdk_version);
 645     int build = JDK_VERSION_BUILD(info.jdk_version);
 646     if (major == 1 && minor > 4) {
 647       // We represent "1.5.0" as "5.0", but 1.4.2 as itself.
 648       major = minor;
 649       minor = micro;
 650       micro = 0;
 651     }
 652     _current = JDK_Version(major, minor, micro, info.update_version,
 653                            info.special_update_version, build,
 654                            info.thread_park_blocker == 1,
 655                            info.post_vm_init_hook_enabled == 1,
 656                            info.pending_list_uses_discovered_field == 1);
 657   }
 658 }
 659 
 660 void JDK_Version::fully_initialize(
 661     uint8_t major, uint8_t minor, uint8_t micro, uint8_t update) {
 662   // This is only called when current is less than 1.6 and we've gotten
 663   // far enough in the initialization to determine the exact version.
 664   assert(major < 6, "not needed for JDK version >= 6");
 665   assert(is_partially_initialized(), "must not initialize");
 666   if (major < 5) {
 667     // JDK verison sequence: 1.2.x, 1.3.x, 1.4.x, 5.0.x, 6.0.x, etc.
 668     micro = minor;
 669     minor = major;
 670     major = 1;
 671   }
 672   _current = JDK_Version(major, minor, micro, update);
 673 }
 674 
 675 void JDK_Version_init() {
 676   JDK_Version::initialize();
 677 }
 678 
 679 static int64_t encode_jdk_version(const JDK_Version& v) {
 680   return
 681     ((int64_t)v.major_version()          << (BitsPerByte * 5)) |
 682     ((int64_t)v.minor_version()          << (BitsPerByte * 4)) |
 683     ((int64_t)v.micro_version()          << (BitsPerByte * 3)) |
 684     ((int64_t)v.update_version()         << (BitsPerByte * 2)) |
 685     ((int64_t)v.special_update_version() << (BitsPerByte * 1)) |
 686     ((int64_t)v.build_number()           << (BitsPerByte * 0));
 687 }
 688 
 689 int JDK_Version::compare(const JDK_Version& other) const {
 690   assert(is_valid() && other.is_valid(), "Invalid version (uninitialized?)");
 691   if (!is_partially_initialized() && other.is_partially_initialized()) {
 692     return -(other.compare(*this)); // flip the comparators
 693   }
 694   assert(!other.is_partially_initialized(), "Not initialized yet");
 695   if (is_partially_initialized()) {
 696     assert(other.major_version() >= 6,
 697            "Invalid JDK version comparison during initialization");
 698     return -1;
 699   } else {
 700     uint64_t e = encode_jdk_version(*this);
 701     uint64_t o = encode_jdk_version(other);
 702     return (e > o) ? 1 : ((e == o) ? 0 : -1);
 703   }
 704 }
 705 
 706 void JDK_Version::to_string(char* buffer, size_t buflen) const {
 707   assert(buffer && buflen > 0, "call with useful buffer");
 708   size_t index = 0;
 709 
 710   if (!is_valid()) {
 711     jio_snprintf(buffer, buflen, "%s", "(uninitialized)");
 712   } else if (is_partially_initialized()) {
 713     jio_snprintf(buffer, buflen, "%s", "(uninitialized) pre-1.6.0");
 714   } else {
 715     int rc = jio_snprintf(
 716         &buffer[index], buflen - index, "%d.%d", _major, _minor);
 717     if (rc == -1) return;
 718     index += rc;
 719     if (_micro > 0) {
 720       rc = jio_snprintf(&buffer[index], buflen - index, ".%d", _micro);
 721     }
 722     if (_update > 0) {
 723       rc = jio_snprintf(&buffer[index], buflen - index, "_%02d", _update);
 724       if (rc == -1) return;
 725       index += rc;
 726     }
 727     if (_special > 0) {
 728       rc = jio_snprintf(&buffer[index], buflen - index, "%c", _special);
 729       if (rc == -1) return;
 730       index += rc;
 731     }
 732     if (_build > 0) {
 733       rc = jio_snprintf(&buffer[index], buflen - index, "-b%02d", _build);
 734       if (rc == -1) return;
 735       index += rc;
 736     }
 737   }
 738 }