java.cpp revision 9111:a41fe5ffa839 
1/*
2 * Copyright (c) 1997, 2015, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25#include "precompiled.hpp"
26#include "classfile/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 "gc/shared/genCollectedHeap.hpp"
33#include "interpreter/bytecodeHistogram.hpp"
34#if INCLUDE_JVMCI
35#include "jvmci/jvmciCompiler.hpp"
36#include "jvmci/jvmciRuntime.hpp"
37#endif
38#include "memory/oopFactory.hpp"
39#include "memory/universe.hpp"
40#include "oops/constantPool.hpp"
41#include "oops/generateOopMap.hpp"
42#include "oops/instanceKlass.hpp"
43#include "oops/instanceOop.hpp"
44#include "oops/method.hpp"
45#include "oops/objArrayOop.hpp"
46#include "oops/oop.inline.hpp"
47#include "oops/symbol.hpp"
48#include "prims/jvmtiExport.hpp"
49#include "runtime/arguments.hpp"
50#include "runtime/biasedLocking.hpp"
51#include "runtime/compilationPolicy.hpp"
52#include "runtime/fprofiler.hpp"
53#include "runtime/init.hpp"
54#include "runtime/interfaceSupport.hpp"
55#include "runtime/java.hpp"
56#include "runtime/memprofiler.hpp"
57#include "runtime/sharedRuntime.hpp"
58#include "runtime/statSampler.hpp"
59#include "runtime/sweeper.hpp"
60#include "runtime/task.hpp"
61#include "runtime/thread.inline.hpp"
62#include "runtime/timer.hpp"
63#include "runtime/vm_operations.hpp"
64#include "services/memTracker.hpp"
65#include "trace/tracing.hpp"
66#include "utilities/dtrace.hpp"
67#include "utilities/globalDefinitions.hpp"
68#include "utilities/histogram.hpp"
69#include "utilities/macros.hpp"
70#include "utilities/vmError.hpp"
71#if INCLUDE_ALL_GCS
72#include "gc/cms/concurrentMarkSweepThread.hpp"
73#include "gc/parallel/psScavenge.hpp"
74#endif // INCLUDE_ALL_GCS
75#ifdef COMPILER1
76#include "c1/c1_Compiler.hpp"
77#include "c1/c1_Runtime1.hpp"
78#endif
79#ifdef COMPILER2
80#include "code/compiledIC.hpp"
81#include "compiler/methodLiveness.hpp"
82#include "opto/compile.hpp"
83#include "opto/indexSet.hpp"
84#include "opto/runtime.hpp"
85#endif
86
87PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC
88
89GrowableArray<Method*>* collected_profiled_methods;
90
91int compare_methods(Method** a, Method** b) {
92  // %%% there can be 32-bit overflow here
93  return ((*b)->invocation_count() + (*b)->compiled_invocation_count())
94       - ((*a)->invocation_count() + (*a)->compiled_invocation_count());
95}
96
97void collect_profiled_methods(Method* m) {
98  Thread* thread = Thread::current();
99  // This HandleMark prevents a huge amount of handles from being added
100  // to the metadata_handles() array on the thread.
101  HandleMark hm(thread);
102  methodHandle mh(thread, m);
103  if ((m->method_data() != NULL) &&
104      (PrintMethodData || CompilerOracle::should_print(mh))) {
105    collected_profiled_methods->push(m);
106  }
107}
108
109void print_method_profiling_data() {
110  if (ProfileInterpreter COMPILER1_PRESENT(|| C1UpdateMethodData) &&
111     (PrintMethodData || CompilerOracle::should_print_methods())) {
112    ResourceMark rm;
113    HandleMark hm;
114    collected_profiled_methods = new GrowableArray<Method*>(1024);
115    ClassLoaderDataGraph::methods_do(collect_profiled_methods);
116    collected_profiled_methods->sort(&compare_methods);
117
118    int count = collected_profiled_methods->length();
119    int total_size = 0;
120    if (count > 0) {
121      for (int index = 0; index < count; index++) {
122        Method* m = collected_profiled_methods->at(index);
123        ttyLocker ttyl;
124        tty->print_cr("------------------------------------------------------------------------");
125        m->print_invocation_count();
126        tty->print_cr("  mdo size: %d bytes", m->method_data()->size_in_bytes());
127        tty->cr();
128        // Dump data on parameters if any
129        if (m->method_data() != NULL && m->method_data()->parameters_type_data() != NULL) {
130          tty->fill_to(2);
131          m->method_data()->parameters_type_data()->print_data_on(tty);
132        }
133        m->print_codes();
134        total_size += m->method_data()->size_in_bytes();
135      }
136      tty->print_cr("------------------------------------------------------------------------");
137      tty->print_cr("Total MDO size: %d bytes", total_size);
138    }
139  }
140}
141
142
143#ifndef PRODUCT
144
145// Statistics printing (method invocation histogram)
146
147GrowableArray<Method*>* collected_invoked_methods;
148
149void collect_invoked_methods(Method* m) {
150  if (m->invocation_count() + m->compiled_invocation_count() >= 1 ) {
151    collected_invoked_methods->push(m);
152  }
153}
154
155
156
157
158void print_method_invocation_histogram() {
159  ResourceMark rm;
160  HandleMark hm;
161  collected_invoked_methods = new GrowableArray<Method*>(1024);
162  SystemDictionary::methods_do(collect_invoked_methods);
163  collected_invoked_methods->sort(&compare_methods);
164  //
165  tty->cr();
166  tty->print_cr("Histogram Over MethodOop Invocation Counters (cutoff = %d):", MethodHistogramCutoff);
167  tty->cr();
168  tty->print_cr("____Count_(I+C)____Method________________________Module_________________");
169  unsigned total = 0, int_total = 0, comp_total = 0, static_total = 0, final_total = 0,
170      synch_total = 0, nativ_total = 0, acces_total = 0;
171  for (int index = 0; index < collected_invoked_methods->length(); index++) {
172    Method* m = collected_invoked_methods->at(index);
173    int c = m->invocation_count() + m->compiled_invocation_count();
174    if (c >= MethodHistogramCutoff) m->print_invocation_count();
175    int_total  += m->invocation_count();
176    comp_total += m->compiled_invocation_count();
177    if (m->is_final())        final_total  += c;
178    if (m->is_static())       static_total += c;
179    if (m->is_synchronized()) synch_total  += c;
180    if (m->is_native())       nativ_total  += c;
181    if (m->is_accessor())     acces_total  += c;
182  }
183  tty->cr();
184  total = int_total + comp_total;
185  tty->print_cr("Invocations summary:");
186  tty->print_cr("\t%9d (%4.1f%%) interpreted",  int_total,    100.0 * int_total    / total);
187  tty->print_cr("\t%9d (%4.1f%%) compiled",     comp_total,   100.0 * comp_total   / total);
188  tty->print_cr("\t%9d (100%%)  total",         total);
189  tty->print_cr("\t%9d (%4.1f%%) synchronized", synch_total,  100.0 * synch_total  / total);
190  tty->print_cr("\t%9d (%4.1f%%) final",        final_total,  100.0 * final_total  / total);
191  tty->print_cr("\t%9d (%4.1f%%) static",       static_total, 100.0 * static_total / total);
192  tty->print_cr("\t%9d (%4.1f%%) native",       nativ_total,  100.0 * nativ_total  / total);
193  tty->print_cr("\t%9d (%4.1f%%) accessor",     acces_total,  100.0 * acces_total  / total);
194  tty->cr();
195  SharedRuntime::print_call_statistics(comp_total);
196}
197
198void print_bytecode_count() {
199  if (CountBytecodes || TraceBytecodes || StopInterpreterAt) {
200    tty->print_cr("[BytecodeCounter::counter_value = %d]", BytecodeCounter::counter_value());
201  }
202}
203
204AllocStats alloc_stats;
205
206
207
208// General statistics printing (profiling ...)
209void print_statistics() {
210#ifdef ASSERT
211
212  if (CountRuntimeCalls) {
213    extern Histogram *RuntimeHistogram;
214    RuntimeHistogram->print();
215  }
216
217  if (CountJNICalls) {
218    extern Histogram *JNIHistogram;
219    JNIHistogram->print();
220  }
221
222  if (CountJVMCalls) {
223    extern Histogram *JVMHistogram;
224    JVMHistogram->print();
225  }
226
227#endif
228
229  if (MemProfiling) {
230    MemProfiler::disengage();
231  }
232
233  if (CITime) {
234    CompileBroker::print_times();
235  }
236
237#ifdef COMPILER1
238  if ((PrintC1Statistics || LogVMOutput || LogCompilation) && UseCompiler) {
239    FlagSetting fs(DisplayVMOutput, DisplayVMOutput && PrintC1Statistics);
240    Runtime1::print_statistics();
241    Deoptimization::print_statistics();
242    SharedRuntime::print_statistics();
243  }
244#endif /* COMPILER1 */
245
246#ifdef COMPILER2
247  if ((PrintOptoStatistics || LogVMOutput || LogCompilation) && UseCompiler) {
248    FlagSetting fs(DisplayVMOutput, DisplayVMOutput && PrintOptoStatistics);
249    Compile::print_statistics();
250#ifndef COMPILER1
251    Deoptimization::print_statistics();
252    SharedRuntime::print_statistics();
253#endif //COMPILER1
254    os::print_statistics();
255  }
256
257  if (PrintLockStatistics || PrintPreciseBiasedLockingStatistics || PrintPreciseRTMLockingStatistics) {
258    OptoRuntime::print_named_counters();
259  }
260
261  if (TimeLivenessAnalysis) {
262    MethodLiveness::print_times();
263  }
264#ifdef ASSERT
265  if (CollectIndexSetStatistics) {
266    IndexSet::print_statistics();
267  }
268#endif // ASSERT
269#else
270#ifdef INCLUDE_JVMCI
271#ifndef COMPILER1
272  if ((TraceDeoptimization || LogVMOutput || LogCompilation) && UseCompiler) {
273    FlagSetting fs(DisplayVMOutput, DisplayVMOutput && TraceDeoptimization);
274    Deoptimization::print_statistics();
275    SharedRuntime::print_statistics();
276  }
277#endif
278#endif
279#endif
280
281  if (PrintNMethodStatistics) {
282    nmethod::print_statistics();
283  }
284  if (CountCompiledCalls) {
285    print_method_invocation_histogram();
286  }
287
288  print_method_profiling_data();
289
290  if (TimeCompilationPolicy) {
291    CompilationPolicy::policy()->print_time();
292  }
293  if (TimeOopMap) {
294    GenerateOopMap::print_time();
295  }
296  if (ProfilerCheckIntervals) {
297    PeriodicTask::print_intervals();
298  }
299  if (PrintSymbolTableSizeHistogram) {
300    SymbolTable::print_histogram();
301  }
302  if (CountBytecodes || TraceBytecodes || StopInterpreterAt) {
303    BytecodeCounter::print();
304  }
305  if (PrintBytecodePairHistogram) {
306    BytecodePairHistogram::print();
307  }
308
309  if (PrintCodeCache) {
310    MutexLockerEx mu(CodeCache_lock, Mutex::_no_safepoint_check_flag);
311    CodeCache::print();
312  }
313
314  if (PrintMethodFlushingStatistics) {
315    NMethodSweeper::print();
316  }
317
318  if (PrintCodeCache2) {
319    MutexLockerEx mu(CodeCache_lock, Mutex::_no_safepoint_check_flag);
320    CodeCache::print_internals();
321  }
322
323  if (PrintVtableStats) {
324    klassVtable::print_statistics();
325    klassItable::print_statistics();
326  }
327  if (VerifyOops) {
328    tty->print_cr("+VerifyOops count: %d", StubRoutines::verify_oop_count());
329  }
330
331  print_bytecode_count();
332  if (PrintMallocStatistics) {
333    tty->print("allocation stats: ");
334    alloc_stats.print();
335    tty->cr();
336  }
337
338  if (PrintSystemDictionaryAtExit) {
339    SystemDictionary::print();
340  }
341
342  if (LogTouchedMethods && PrintTouchedMethodsAtExit) {
343    Method::print_touched_methods(tty);
344  }
345
346  if (PrintBiasedLockingStatistics) {
347    BiasedLocking::print_counters();
348  }
349
350  // Native memory tracking data
351  if (PrintNMTStatistics) {
352    MemTracker::final_report(tty);
353  }
354}
355
356#else // PRODUCT MODE STATISTICS
357
358void print_statistics() {
359
360  if (PrintMethodData) {
361    print_method_profiling_data();
362  }
363
364  if (CITime) {
365    CompileBroker::print_times();
366  }
367
368  if (PrintCodeCache) {
369    MutexLockerEx mu(CodeCache_lock, Mutex::_no_safepoint_check_flag);
370    CodeCache::print();
371  }
372
373  if (PrintMethodFlushingStatistics) {
374    NMethodSweeper::print();
375  }
376
377#ifdef COMPILER2
378  if (PrintPreciseBiasedLockingStatistics || PrintPreciseRTMLockingStatistics) {
379    OptoRuntime::print_named_counters();
380  }
381#endif
382  if (PrintBiasedLockingStatistics) {
383    BiasedLocking::print_counters();
384  }
385
386  // Native memory tracking data
387  if (PrintNMTStatistics) {
388    MemTracker::final_report(tty);
389  }
390
391  if (LogTouchedMethods && PrintTouchedMethodsAtExit) {
392    Method::print_touched_methods(tty);
393  }
394}
395
396#endif
397
398// Note: before_exit() can be executed only once, if more than one threads
399//       are trying to shutdown the VM at the same time, only one thread
400//       can run before_exit() and all other threads must wait.
401void before_exit(JavaThread * thread) {
402  #define BEFORE_EXIT_NOT_RUN 0
403  #define BEFORE_EXIT_RUNNING 1
404  #define BEFORE_EXIT_DONE    2
405  static jint volatile _before_exit_status = BEFORE_EXIT_NOT_RUN;
406
407  // Note: don't use a Mutex to guard the entire before_exit(), as
408  // JVMTI post_thread_end_event and post_vm_death_event will run native code.
409  // A CAS or OSMutex would work just fine but then we need to manipulate
410  // thread state for Safepoint. Here we use Monitor wait() and notify_all()
411  // for synchronization.
412  { MutexLocker ml(BeforeExit_lock);
413    switch (_before_exit_status) {
414    case BEFORE_EXIT_NOT_RUN:
415      _before_exit_status = BEFORE_EXIT_RUNNING;
416      break;
417    case BEFORE_EXIT_RUNNING:
418      while (_before_exit_status == BEFORE_EXIT_RUNNING) {
419        BeforeExit_lock->wait();
420      }
421      assert(_before_exit_status == BEFORE_EXIT_DONE, "invalid state");
422      return;
423    case BEFORE_EXIT_DONE:
424      return;
425    }
426  }
427
428#if INCLUDE_JVMCI
429  JVMCIRuntime::shutdown();
430#endif
431
432  // Hang forever on exit if we're reporting an error.
433  if (ShowMessageBoxOnError && is_error_reported()) {
434    os::infinite_sleep();
435  }
436
437  // Stop the WatcherThread. We do this before disenrolling various
438  // PeriodicTasks to reduce the likelihood of races.
439  if (PeriodicTask::num_tasks() > 0) {
440    WatcherThread::stop();
441  }
442
443  // Print statistics gathered (profiling ...)
444  if (Arguments::has_profile()) {
445    FlatProfiler::disengage();
446    FlatProfiler::print(10);
447  }
448
449  // shut down the StatSampler task
450  StatSampler::disengage();
451  StatSampler::destroy();
452
453  // Stop concurrent GC threads
454  Universe::heap()->stop();
455
456  // Print GC/heap related information.
457  if (PrintGCDetails) {
458    Universe::print();
459    AdaptiveSizePolicyOutput(0);
460    if (Verbose) {
461      ClassLoaderDataGraph::dump_on(gclog_or_tty);
462    }
463  }
464
465  if (PrintBytecodeHistogram) {
466    BytecodeHistogram::print();
467  }
468
469  if (JvmtiExport::should_post_thread_life()) {
470    JvmtiExport::post_thread_end(thread);
471  }
472
473
474  EventThreadEnd event;
475  if (event.should_commit()) {
476      event.set_javalangthread(java_lang_Thread::thread_id(thread->threadObj()));
477      event.commit();
478  }
479
480  // Always call even when there are not JVMTI environments yet, since environments
481  // may be attached late and JVMTI must track phases of VM execution
482  JvmtiExport::post_vm_death();
483  Threads::shutdown_vm_agents();
484
485  // Terminate the signal thread
486  // Note: we don't wait until it actually dies.
487  os::terminate_signal_thread();
488
489  print_statistics();
490  Universe::heap()->print_tracing_info();
491
492  { MutexLocker ml(BeforeExit_lock);
493    _before_exit_status = BEFORE_EXIT_DONE;
494    BeforeExit_lock->notify_all();
495  }
496
497  if (VerifyStringTableAtExit) {
498    int fail_cnt = 0;
499    {
500      MutexLocker ml(StringTable_lock);
501      fail_cnt = StringTable::verify_and_compare_entries();
502    }
503
504    if (fail_cnt != 0) {
505      tty->print_cr("ERROR: fail_cnt=%d", fail_cnt);
506      guarantee(fail_cnt == 0, "unexpected StringTable verification failures");
507    }
508  }
509
510  #undef BEFORE_EXIT_NOT_RUN
511  #undef BEFORE_EXIT_RUNNING
512  #undef BEFORE_EXIT_DONE
513}
514
515void vm_exit(int code) {
516  Thread* thread = ThreadLocalStorage::is_initialized() ?
517    ThreadLocalStorage::get_thread_slow() : NULL;
518  if (thread == NULL) {
519    // we have serious problems -- just exit
520    vm_direct_exit(code);
521  }
522
523  if (VMThread::vm_thread() != NULL) {
524    // Fire off a VM_Exit operation to bring VM to a safepoint and exit
525    VM_Exit op(code);
526    if (thread->is_Java_thread())
527      ((JavaThread*)thread)->set_thread_state(_thread_in_vm);
528    VMThread::execute(&op);
529    // should never reach here; but in case something wrong with VM Thread.
530    vm_direct_exit(code);
531  } else {
532    // VM thread is gone, just exit
533    vm_direct_exit(code);
534  }
535  ShouldNotReachHere();
536}
537
538void notify_vm_shutdown() {
539  // For now, just a dtrace probe.
540  HOTSPOT_VM_SHUTDOWN();
541  HS_DTRACE_WORKAROUND_TAIL_CALL_BUG();
542}
543
544void vm_direct_exit(int code) {
545  notify_vm_shutdown();
546  os::wait_for_keypress_at_exit();
547  os::exit(code);
548}
549
550void vm_perform_shutdown_actions() {
551  // Warning: do not call 'exit_globals()' here. All threads are still running.
552  // Calling 'exit_globals()' will disable thread-local-storage and cause all
553  // kinds of assertions to trigger in debug mode.
554  if (is_init_completed()) {
555    Thread* thread = ThreadLocalStorage::is_initialized() ?
556                     ThreadLocalStorage::get_thread_slow() : NULL;
557    if (thread != NULL && thread->is_Java_thread()) {
558      // We are leaving the VM, set state to native (in case any OS exit
559      // handlers call back to the VM)
560      JavaThread* jt = (JavaThread*)thread;
561      // Must always be walkable or have no last_Java_frame when in
562      // thread_in_native
563      jt->frame_anchor()->make_walkable(jt);
564      jt->set_thread_state(_thread_in_native);
565    }
566  }
567  notify_vm_shutdown();
568}
569
570void vm_shutdown()
571{
572  vm_perform_shutdown_actions();
573  os::wait_for_keypress_at_exit();
574  os::shutdown();
575}
576
577void vm_abort(bool dump_core) {
578  vm_perform_shutdown_actions();
579  os::wait_for_keypress_at_exit();
580  os::abort(dump_core);
581  ShouldNotReachHere();
582}
583
584void vm_notify_during_shutdown(const char* error, const char* message) {
585  if (error != NULL) {
586    tty->print_cr("Error occurred during initialization of VM");
587    tty->print("%s", error);
588    if (message != NULL) {
589      tty->print_cr(": %s", message);
590    }
591    else {
592      tty->cr();
593    }
594  }
595  if (ShowMessageBoxOnError && WizardMode) {
596    fatal("Error occurred during initialization of VM");
597  }
598}
599
600void vm_exit_during_initialization(Handle exception) {
601  tty->print_cr("Error occurred during initialization of VM");
602  // If there are exceptions on this thread it must be cleared
603  // first and here. Any future calls to EXCEPTION_MARK requires
604  // that no pending exceptions exist.
605  Thread *THREAD = Thread::current();
606  if (HAS_PENDING_EXCEPTION) {
607    CLEAR_PENDING_EXCEPTION;
608  }
609  java_lang_Throwable::print(exception, tty);
610  tty->cr();
611  java_lang_Throwable::print_stack_trace(exception(), tty);
612  tty->cr();
613  vm_notify_during_shutdown(NULL, NULL);
614
615  // Failure during initialization, we don't want to dump core
616  vm_abort(false);
617}
618
619void vm_exit_during_initialization(Symbol* ex, const char* message) {
620  ResourceMark rm;
621  vm_notify_during_shutdown(ex->as_C_string(), message);
622
623  // Failure during initialization, we don't want to dump core
624  vm_abort(false);
625}
626
627void vm_exit_during_initialization(const char* error, const char* message) {
628  vm_notify_during_shutdown(error, message);
629
630  // Failure during initialization, we don't want to dump core
631  vm_abort(false);
632}
633
634void vm_shutdown_during_initialization(const char* error, const char* message) {
635  vm_notify_during_shutdown(error, message);
636  vm_shutdown();
637}
638
639JDK_Version JDK_Version::_current;
640const char* JDK_Version::_runtime_name;
641const char* JDK_Version::_runtime_version;
642
643void JDK_Version::initialize() {
644  jdk_version_info info;
645  assert(!_current.is_valid(), "Don't initialize twice");
646
647  void *lib_handle = os::native_java_library();
648  jdk_version_info_fn_t func = CAST_TO_FN_PTR(jdk_version_info_fn_t,
649     os::dll_lookup(lib_handle, "JDK_GetVersionInfo0"));
650
651  if (func == NULL) {
652    // JDK older than 1.6
653    _current._partially_initialized = true;
654  } else {
655    (*func)(&info, sizeof(info));
656
657    int major = JDK_VERSION_MAJOR(info.jdk_version);
658    int minor = JDK_VERSION_MINOR(info.jdk_version);
659    int micro = JDK_VERSION_MICRO(info.jdk_version);
660    int build = JDK_VERSION_BUILD(info.jdk_version);
661    if (major == 1 && minor > 4) {
662      // We represent "1.5.0" as "5.0", but 1.4.2 as itself.
663      major = minor;
664      minor = micro;
665      micro = 0;
666    }
667    // Incompatible with pre-4243978 JDK.
668    if (info.pending_list_uses_discovered_field == 0) {
669      vm_exit_during_initialization(
670        "Incompatible JDK is not using Reference.discovered field for pending list");
671    }
672    _current = JDK_Version(major, minor, micro, info.update_version,
673                           info.special_update_version, build,
674                           info.thread_park_blocker == 1,
675                           info.post_vm_init_hook_enabled == 1);
676  }
677}
678
679void JDK_Version::fully_initialize(
680    uint8_t major, uint8_t minor, uint8_t micro, uint8_t update) {
681  // This is only called when current is less than 1.6 and we've gotten
682  // far enough in the initialization to determine the exact version.
683  assert(major < 6, "not needed for JDK version >= 6");
684  assert(is_partially_initialized(), "must not initialize");
685  if (major < 5) {
686    // JDK verison sequence: 1.2.x, 1.3.x, 1.4.x, 5.0.x, 6.0.x, etc.
687    micro = minor;
688    minor = major;
689    major = 1;
690  }
691  _current = JDK_Version(major, minor, micro, update);
692}
693
694void JDK_Version_init() {
695  JDK_Version::initialize();
696}
697
698static int64_t encode_jdk_version(const JDK_Version& v) {
699  return
700    ((int64_t)v.major_version()          << (BitsPerByte * 5)) |
701    ((int64_t)v.minor_version()          << (BitsPerByte * 4)) |
702    ((int64_t)v.micro_version()          << (BitsPerByte * 3)) |
703    ((int64_t)v.update_version()         << (BitsPerByte * 2)) |
704    ((int64_t)v.special_update_version() << (BitsPerByte * 1)) |
705    ((int64_t)v.build_number()           << (BitsPerByte * 0));
706}
707
708int JDK_Version::compare(const JDK_Version& other) const {
709  assert(is_valid() && other.is_valid(), "Invalid version (uninitialized?)");
710  if (!is_partially_initialized() && other.is_partially_initialized()) {
711    return -(other.compare(*this)); // flip the comparators
712  }
713  assert(!other.is_partially_initialized(), "Not initialized yet");
714  if (is_partially_initialized()) {
715    assert(other.major_version() >= 6,
716           "Invalid JDK version comparison during initialization");
717    return -1;
718  } else {
719    uint64_t e = encode_jdk_version(*this);
720    uint64_t o = encode_jdk_version(other);
721    return (e > o) ? 1 : ((e == o) ? 0 : -1);
722  }
723}
724
725void JDK_Version::to_string(char* buffer, size_t buflen) const {
726  assert(buffer && buflen > 0, "call with useful buffer");
727  size_t index = 0;
728
729  if (!is_valid()) {
730    jio_snprintf(buffer, buflen, "%s", "(uninitialized)");
731  } else if (is_partially_initialized()) {
732    jio_snprintf(buffer, buflen, "%s", "(uninitialized) pre-1.6.0");
733  } else {
734    int rc = jio_snprintf(
735        &buffer[index], buflen - index, "%d.%d", _major, _minor);
736    if (rc == -1) return;
737    index += rc;
738    if (_micro > 0) {
739      rc = jio_snprintf(&buffer[index], buflen - index, ".%d", _micro);
740    }
741    if (_update > 0) {
742      rc = jio_snprintf(&buffer[index], buflen - index, "_%02d", _update);
743      if (rc == -1) return;
744      index += rc;
745    }
746    if (_special > 0) {
747      rc = jio_snprintf(&buffer[index], buflen - index, "%c", _special);
748      if (rc == -1) return;
749      index += rc;
750    }
751    if (_build > 0) {
752      rc = jio_snprintf(&buffer[index], buflen - index, "-b%02d", _build);
753      if (rc == -1) return;
754      index += rc;
755    }
756  }
757}
758