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src/hotspot/share/runtime/thread.cpp

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rev 47674 : Port 09.17.Thread_SMR_logging_update from JDK9 to JDK10
rev 47675 : sspitsyn, dcubed, eosterlund CR - minor changes prior to OpenJDK review.
rev 47676 : eosterlund, stefank CR - refactor code into threadSMR.cpp and threadSMR.hpp
rev 47677 : eosterlund CR - need more inline fixes.
rev 47678 : eosterlund, stefank CR - more inline and style cleanups
rev 47679 : stefank, coleenp CR - refactor most JavaThreadIterator usage to use JavaThreadIteratorWithHandle.


  53 #include "oops/symbol.hpp"
  54 #include "oops/verifyOopClosure.hpp"
  55 #include "prims/jvm_misc.hpp"
  56 #include "prims/jvmtiExport.hpp"
  57 #include "prims/jvmtiThreadState.hpp"
  58 #include "prims/privilegedStack.hpp"
  59 #include "runtime/arguments.hpp"
  60 #include "runtime/atomic.hpp"
  61 #include "runtime/biasedLocking.hpp"
  62 #include "runtime/commandLineFlagConstraintList.hpp"
  63 #include "runtime/commandLineFlagWriteableList.hpp"
  64 #include "runtime/commandLineFlagRangeList.hpp"
  65 #include "runtime/deoptimization.hpp"
  66 #include "runtime/frame.inline.hpp"
  67 #include "runtime/globals.hpp"
  68 #include "runtime/init.hpp"
  69 #include "runtime/interfaceSupport.hpp"
  70 #include "runtime/java.hpp"
  71 #include "runtime/javaCalls.hpp"
  72 #include "runtime/jniPeriodicChecker.hpp"
  73 #include "runtime/timerTrace.hpp"
  74 #include "runtime/memprofiler.hpp"
  75 #include "runtime/mutexLocker.hpp"
  76 #include "runtime/objectMonitor.hpp"
  77 #include "runtime/orderAccess.inline.hpp"
  78 #include "runtime/osThread.hpp"

  79 #include "runtime/safepoint.hpp"
  80 #include "runtime/sharedRuntime.hpp"
  81 #include "runtime/statSampler.hpp"
  82 #include "runtime/stubRoutines.hpp"
  83 #include "runtime/sweeper.hpp"
  84 #include "runtime/task.hpp"
  85 #include "runtime/thread.inline.hpp"
  86 #include "runtime/threadCritical.hpp"



  87 #include "runtime/vframe.hpp"
  88 #include "runtime/vframeArray.hpp"
  89 #include "runtime/vframe_hp.hpp"
  90 #include "runtime/vmThread.hpp"
  91 #include "runtime/vm_operations.hpp"
  92 #include "runtime/vm_version.hpp"
  93 #include "services/attachListener.hpp"
  94 #include "services/management.hpp"
  95 #include "services/memTracker.hpp"
  96 #include "services/threadService.hpp"
  97 #include "trace/traceMacros.hpp"
  98 #include "trace/tracing.hpp"
  99 #include "utilities/align.hpp"
 100 #include "utilities/defaultStream.hpp"
 101 #include "utilities/dtrace.hpp"
 102 #include "utilities/events.hpp"
 103 #include "utilities/macros.hpp"
 104 #include "utilities/preserveException.hpp"

 105 #include "utilities/vmError.hpp"
 106 #if INCLUDE_ALL_GCS
 107 #include "gc/cms/concurrentMarkSweepThread.hpp"
 108 #include "gc/g1/concurrentMarkThread.inline.hpp"
 109 #include "gc/parallel/pcTasks.hpp"
 110 #endif // INCLUDE_ALL_GCS
 111 #if INCLUDE_JVMCI
 112 #include "jvmci/jvmciCompiler.hpp"
 113 #include "jvmci/jvmciRuntime.hpp"
 114 #include "logging/logHandle.hpp"
 115 #endif
 116 #ifdef COMPILER1
 117 #include "c1/c1_Compiler.hpp"
 118 #endif
 119 #ifdef COMPILER2
 120 #include "opto/c2compiler.hpp"
 121 #include "opto/idealGraphPrinter.hpp"
 122 #endif
 123 #if INCLUDE_RTM_OPT
 124 #include "runtime/rtmLocking.hpp"


 176                                                          AllocFailStrategy::RETURN_NULL);
 177     void* aligned_addr     = align_up(real_malloc_addr, alignment);
 178     assert(((uintptr_t) aligned_addr + (uintptr_t) size) <=
 179            ((uintptr_t) real_malloc_addr + (uintptr_t) aligned_size),
 180            "JavaThread alignment code overflowed allocated storage");
 181     if (aligned_addr != real_malloc_addr) {
 182       log_info(biasedlocking)("Aligned thread " INTPTR_FORMAT " to " INTPTR_FORMAT,
 183                               p2i(real_malloc_addr),
 184                               p2i(aligned_addr));
 185     }
 186     ((Thread*) aligned_addr)->_real_malloc_address = real_malloc_addr;
 187     return aligned_addr;
 188   } else {
 189     return throw_excpt? AllocateHeap(size, flags, CURRENT_PC)
 190                        : AllocateHeap(size, flags, CURRENT_PC, AllocFailStrategy::RETURN_NULL);
 191   }
 192 }
 193 
 194 void Thread::operator delete(void* p) {
 195   if (UseBiasedLocking) {
 196     void* real_malloc_addr = ((Thread*) p)->_real_malloc_address;
 197     FreeHeap(real_malloc_addr);
 198   } else {
 199     FreeHeap(p);
 200   }
 201 }
 202 







 203 
 204 // Base class for all threads: VMThread, WatcherThread, ConcurrentMarkSweepThread,
 205 // JavaThread
 206 
 207 
 208 Thread::Thread() {
 209   // stack and get_thread
 210   set_stack_base(NULL);
 211   set_stack_size(0);
 212   set_self_raw_id(0);
 213   set_lgrp_id(-1);
 214   DEBUG_ONLY(clear_suspendible_thread();)
 215 
 216   // allocated data structures
 217   set_osthread(NULL);
 218   set_resource_area(new (mtThread)ResourceArea());
 219   DEBUG_ONLY(_current_resource_mark = NULL;)
 220   set_handle_area(new (mtThread) HandleArea(NULL));
 221   set_metadata_handles(new (ResourceObj::C_HEAP, mtClass) GrowableArray<Metadata*>(30, true));
 222   set_active_handles(NULL);
 223   set_free_handle_block(NULL);
 224   set_last_handle_mark(NULL);
 225 
 226   // This initial value ==> never claimed.
 227   _oops_do_parity = 0;



 228 
 229   // the handle mark links itself to last_handle_mark
 230   new HandleMark(this);
 231 
 232   // plain initialization
 233   debug_only(_owned_locks = NULL;)
 234   debug_only(_allow_allocation_count = 0;)
 235   NOT_PRODUCT(_allow_safepoint_count = 0;)
 236   NOT_PRODUCT(_skip_gcalot = false;)
 237   _jvmti_env_iteration_count = 0;
 238   set_allocated_bytes(0);
 239   _vm_operation_started_count = 0;
 240   _vm_operation_completed_count = 0;
 241   _current_pending_monitor = NULL;
 242   _current_pending_monitor_is_from_java = true;
 243   _current_waiting_monitor = NULL;
 244   _num_nested_signal = 0;
 245   omFreeList = NULL;
 246   omFreeCount = 0;
 247   omFreeProvision = 32;


 379   _SR_lock = NULL;
 380 
 381   // osthread() can be NULL, if creation of thread failed.
 382   if (osthread() != NULL) os::free_thread(osthread());
 383 
 384   // clear Thread::current if thread is deleting itself.
 385   // Needed to ensure JNI correctly detects non-attached threads.
 386   if (this == Thread::current()) {
 387     clear_thread_current();
 388   }
 389 
 390   CHECK_UNHANDLED_OOPS_ONLY(if (CheckUnhandledOops) delete unhandled_oops();)
 391 }
 392 
 393 // NOTE: dummy function for assertion purpose.
 394 void Thread::run() {
 395   ShouldNotReachHere();
 396 }
 397 
 398 #ifdef ASSERT
 399 // Private method to check for dangling thread pointer
 400 void check_for_dangling_thread_pointer(Thread *thread) {
 401   assert(!thread->is_Java_thread() || Thread::current() == thread || Threads_lock->owned_by_self(),






 402          "possibility of dangling Thread pointer");
 403 }
 404 #endif
 405 
 406 ThreadPriority Thread::get_priority(const Thread* const thread) {
 407   ThreadPriority priority;
 408   // Can return an error!
 409   (void)os::get_priority(thread, priority);
 410   assert(MinPriority <= priority && priority <= MaxPriority, "non-Java priority found");
 411   return priority;
 412 }
 413 
 414 void Thread::set_priority(Thread* thread, ThreadPriority priority) {
 415   debug_only(check_for_dangling_thread_pointer(thread);)
 416   // Can return an error!
 417   (void)os::set_priority(thread, priority);
 418 }
 419 
 420 
 421 void Thread::start(Thread* thread) {


 713 
 714     if (!pending) {
 715       // A cancelled suspend request is the only false return from
 716       // is_ext_suspend_completed() that keeps us from staying in the
 717       // retry loop.
 718       *bits |= 0x00080000;
 719       return false;
 720     }
 721 
 722     if (is_suspended) {
 723       *bits |= 0x00100000;
 724       return true;
 725     }
 726   } // end retry loop
 727 
 728   // thread did not suspend after all our retries
 729   *bits |= 0x00200000;
 730   return false;
 731 }
 732 































 733 #ifndef PRODUCT
 734 void JavaThread::record_jump(address target, address instr, const char* file,
 735                              int line) {
 736 
 737   // This should not need to be atomic as the only way for simultaneous
 738   // updates is via interrupts. Even then this should be rare or non-existent
 739   // and we don't care that much anyway.
 740 
 741   int index = _jmp_ring_index;
 742   _jmp_ring_index = (index + 1) & (jump_ring_buffer_size - 1);
 743   _jmp_ring[index]._target = (intptr_t) target;
 744   _jmp_ring[index]._instruction = (intptr_t) instr;
 745   _jmp_ring[index]._file = file;
 746   _jmp_ring[index]._line = line;
 747 }
 748 #endif // PRODUCT
 749 
 750 void Thread::interrupt(Thread* thread) {
 751   debug_only(check_for_dangling_thread_pointer(thread);)
 752   os::interrupt(thread);


 791 void Thread::metadata_handles_do(void f(Metadata*)) {
 792   // Only walk the Handles in Thread.
 793   if (metadata_handles() != NULL) {
 794     for (int i = 0; i< metadata_handles()->length(); i++) {
 795       f(metadata_handles()->at(i));
 796     }
 797   }
 798 }
 799 
 800 void Thread::print_on(outputStream* st) const {
 801   // get_priority assumes osthread initialized
 802   if (osthread() != NULL) {
 803     int os_prio;
 804     if (os::get_native_priority(this, &os_prio) == OS_OK) {
 805       st->print("os_prio=%d ", os_prio);
 806     }
 807     st->print("tid=" INTPTR_FORMAT " ", p2i(this));
 808     ext().print_on(st);
 809     osthread()->print_on(st);
 810   }







 811   debug_only(if (WizardMode) print_owned_locks_on(st);)
 812 }
 813 

















 814 // Thread::print_on_error() is called by fatal error handler. Don't use
 815 // any lock or allocate memory.
 816 void Thread::print_on_error(outputStream* st, char* buf, int buflen) const {
 817   assert(!(is_Compiler_thread() || is_Java_thread()), "Can't call name() here if it allocates");
 818 
 819   if (is_VM_thread())                 { st->print("VMThread"); }
 820   else if (is_GC_task_thread())       { st->print("GCTaskThread"); }
 821   else if (is_Watcher_thread())       { st->print("WatcherThread"); }
 822   else if (is_ConcurrentGC_thread())  { st->print("ConcurrentGCThread"); }
 823   else                                { st->print("Thread"); }
 824 
 825   if (is_Named_thread()) {
 826     st->print(" \"%s\"", name());
 827   }
 828 
 829   st->print(" [stack: " PTR_FORMAT "," PTR_FORMAT "]",
 830             p2i(stack_end()), p2i(stack_base()));
 831 
 832   if (osthread()) {
 833     st->print(" [id=%d]", osthread()->thread_id());
 834   }







 835 }
 836 
 837 void Thread::print_value_on(outputStream* st) const {
 838   if (is_Named_thread()) {
 839     st->print(" \"%s\" ", name());
 840   }
 841   st->print(INTPTR_FORMAT, p2i(this));   // print address
 842 }
 843 
 844 #ifdef ASSERT
 845 void Thread::print_owned_locks_on(outputStream* st) const {
 846   Monitor *cur = _owned_locks;
 847   if (cur == NULL) {
 848     st->print(" (no locks) ");
 849   } else {
 850     st->print_cr(" Locks owned:");
 851     while (cur) {
 852       cur->print_on(st);
 853       cur = cur->next();
 854     }
 855   }
 856 }
 857 
 858 static int ref_use_count  = 0;
 859 
 860 bool Thread::owns_locks_but_compiled_lock() const {
 861   for (Monitor *cur = _owned_locks; cur; cur = cur->next()) {
 862     if (cur != Compile_lock) return true;
 863   }
 864   return false;
 865 }
 866 
 867 
 868 #endif
 869 
 870 #ifndef PRODUCT
 871 
 872 // The flag: potential_vm_operation notifies if this particular safepoint state could potential
 873 // invoke the vm-thread (i.e., and oop allocation). In that case, we also have to make sure that
 874 // no threads which allow_vm_block's are held
 875 void Thread::check_for_valid_safepoint_state(bool potential_vm_operation) {
 876   // Check if current thread is allowed to block at a safepoint
 877   if (!(_allow_safepoint_count == 0)) {
 878     fatal("Possible safepoint reached by thread that does not allow it");
 879   }
 880   if (is_Java_thread() && ((JavaThread*)this)->thread_state() != _thread_in_vm) {
 881     fatal("LEAF method calling lock?");
 882   }
 883 
 884 #ifdef ASSERT
 885   if (potential_vm_operation && is_Java_thread()
 886       && !Universe::is_bootstrapping()) {
 887     // Make sure we do not hold any locks that the VM thread also uses.
 888     // This could potentially lead to deadlocks
 889     for (Monitor *cur = _owned_locks; cur; cur = cur->next()) {
 890       // Threads_lock is special, since the safepoint synchronization will not start before this is
 891       // acquired. Hence, a JavaThread cannot be holding it at a safepoint. So is VMOperationRequest_lock,
 892       // since it is used to transfer control between JavaThreads and the VMThread
 893       // Do not *exclude* any locks unless you are absolutely sure it is correct. Ask someone else first!


1379 
1380 void WatcherThread::print_on(outputStream* st) const {
1381   st->print("\"%s\" ", name());
1382   Thread::print_on(st);
1383   st->cr();
1384 }
1385 
1386 // ======= JavaThread ========
1387 
1388 #if INCLUDE_JVMCI
1389 
1390 jlong* JavaThread::_jvmci_old_thread_counters;
1391 
1392 bool jvmci_counters_include(JavaThread* thread) {
1393   oop threadObj = thread->threadObj();
1394   return !JVMCICountersExcludeCompiler || !thread->is_Compiler_thread();
1395 }
1396 
1397 void JavaThread::collect_counters(typeArrayOop array) {
1398   if (JVMCICounterSize > 0) {


1399     MutexLocker tl(Threads_lock);

1400     for (int i = 0; i < array->length(); i++) {
1401       array->long_at_put(i, _jvmci_old_thread_counters[i]);
1402     }
1403     for (JavaThread* tp = Threads::first(); tp != NULL; tp = tp->next()) {
1404       if (jvmci_counters_include(tp)) {
1405         for (int i = 0; i < array->length(); i++) {
1406           array->long_at_put(i, array->long_at(i) + tp->_jvmci_counters[i]);
1407         }
1408       }
1409     }
1410   }
1411 }
1412 
1413 #endif // INCLUDE_JVMCI
1414 
1415 // A JavaThread is a normal Java thread
1416 
1417 void JavaThread::initialize() {
1418   // Initialize fields
1419 
1420   set_saved_exception_pc(NULL);
1421   set_threadObj(NULL);
1422   _anchor.clear();
1423   set_entry_point(NULL);
1424   set_jni_functions(jni_functions());
1425   set_callee_target(NULL);
1426   set_vm_result(NULL);
1427   set_vm_result_2(NULL);
1428   set_vframe_array_head(NULL);
1429   set_vframe_array_last(NULL);
1430   set_deferred_locals(NULL);
1431   set_deopt_mark(NULL);
1432   set_deopt_compiled_method(NULL);
1433   clear_must_deopt_id();
1434   set_monitor_chunks(NULL);
1435   set_next(NULL);

1436   set_thread_state(_thread_new);
1437   _terminated = _not_terminated;
1438   _privileged_stack_top = NULL;
1439   _array_for_gc = NULL;
1440   _suspend_equivalent = false;
1441   _in_deopt_handler = 0;
1442   _doing_unsafe_access = false;
1443   _stack_guard_state = stack_guard_unused;
1444 #if INCLUDE_JVMCI
1445   _pending_monitorenter = false;
1446   _pending_deoptimization = -1;
1447   _pending_failed_speculation = NULL;
1448   _pending_transfer_to_interpreter = false;
1449   _adjusting_comp_level = false;
1450   _jvmci._alternate_call_target = NULL;
1451   assert(_jvmci._implicit_exception_pc == NULL, "must be");
1452   if (JVMCICounterSize > 0) {
1453     _jvmci_counters = NEW_C_HEAP_ARRAY(jlong, JVMCICounterSize, mtInternal);
1454     memset(_jvmci_counters, 0, sizeof(jlong) * JVMCICounterSize);
1455   } else {


1692 void JavaThread::thread_main_inner() {
1693   assert(JavaThread::current() == this, "sanity check");
1694   assert(this->threadObj() != NULL, "just checking");
1695 
1696   // Execute thread entry point unless this thread has a pending exception
1697   // or has been stopped before starting.
1698   // Note: Due to JVM_StopThread we can have pending exceptions already!
1699   if (!this->has_pending_exception() &&
1700       !java_lang_Thread::is_stillborn(this->threadObj())) {
1701     {
1702       ResourceMark rm(this);
1703       this->set_native_thread_name(this->get_thread_name());
1704     }
1705     HandleMark hm(this);
1706     this->entry_point()(this, this);
1707   }
1708 
1709   DTRACE_THREAD_PROBE(stop, this);
1710 
1711   this->exit(false);
1712   delete this;
1713 }
1714 
1715 
1716 static void ensure_join(JavaThread* thread) {
1717   // We do not need to grap the Threads_lock, since we are operating on ourself.
1718   Handle threadObj(thread, thread->threadObj());
1719   assert(threadObj.not_null(), "java thread object must exist");
1720   ObjectLocker lock(threadObj, thread);
1721   // Ignore pending exception (ThreadDeath), since we are exiting anyway
1722   thread->clear_pending_exception();
1723   // Thread is exiting. So set thread_status field in  java.lang.Thread class to TERMINATED.
1724   java_lang_Thread::set_thread_status(threadObj(), java_lang_Thread::TERMINATED);
1725   // Clear the native thread instance - this makes isAlive return false and allows the join()
1726   // to complete once we've done the notify_all below
1727   java_lang_Thread::set_thread(threadObj(), NULL);
1728   lock.notify_all(thread);
1729   // Ignore pending exception (ThreadDeath), since we are exiting anyway
1730   thread->clear_pending_exception();
1731 }
1732 
1733 
1734 // For any new cleanup additions, please check to see if they need to be applied to
1735 // cleanup_failed_attach_current_thread as well.
1736 void JavaThread::exit(bool destroy_vm, ExitType exit_type) {
1737   assert(this == JavaThread::current(), "thread consistency check");
1738 









1739   HandleMark hm(this);
1740   Handle uncaught_exception(this, this->pending_exception());
1741   this->clear_pending_exception();
1742   Handle threadObj(this, this->threadObj());
1743   assert(threadObj.not_null(), "Java thread object should be created");
1744 
1745   // FIXIT: This code should be moved into else part, when reliable 1.2/1.3 check is in place
1746   {
1747     EXCEPTION_MARK;
1748 
1749     CLEAR_PENDING_EXCEPTION;
1750   }
1751   if (!destroy_vm) {
1752     if (uncaught_exception.not_null()) {
1753       EXCEPTION_MARK;
1754       // Call method Thread.dispatchUncaughtException().
1755       Klass* thread_klass = SystemDictionary::Thread_klass();
1756       JavaValue result(T_VOID);
1757       JavaCalls::call_virtual(&result,
1758                               threadObj, thread_klass,


1818         // Implied else:
1819         // Things get a little tricky here. We have a pending external
1820         // suspend request, but we are holding the SR_lock so we
1821         // can't just self-suspend. So we temporarily drop the lock
1822         // and then self-suspend.
1823       }
1824 
1825       ThreadBlockInVM tbivm(this);
1826       java_suspend_self();
1827 
1828       // We're done with this suspend request, but we have to loop around
1829       // and check again. Eventually we will get SR_lock without a pending
1830       // external suspend request and will be able to mark ourselves as
1831       // exiting.
1832     }
1833     // no more external suspends are allowed at this point
1834   } else {
1835     // before_exit() has already posted JVMTI THREAD_END events
1836   }
1837 




1838   // Notify waiters on thread object. This has to be done after exit() is called
1839   // on the thread (if the thread is the last thread in a daemon ThreadGroup the
1840   // group should have the destroyed bit set before waiters are notified).
1841   ensure_join(this);
1842   assert(!this->has_pending_exception(), "ensure_join should have cleared");
1843 




1844   // 6282335 JNI DetachCurrentThread spec states that all Java monitors
1845   // held by this thread must be released. The spec does not distinguish
1846   // between JNI-acquired and regular Java monitors. We can only see
1847   // regular Java monitors here if monitor enter-exit matching is broken.
1848   //
1849   // Optionally release any monitors for regular JavaThread exits. This
1850   // is provided as a work around for any bugs in monitor enter-exit
1851   // matching. This can be expensive so it is not enabled by default.
1852   //
1853   // ensure_join() ignores IllegalThreadStateExceptions, and so does
1854   // ObjectSynchronizer::release_monitors_owned_by_thread().
1855   if (exit_type == jni_detach || ObjectMonitor::Knob_ExitRelease) {
1856     // Sanity check even though JNI DetachCurrentThread() would have
1857     // returned JNI_ERR if there was a Java frame. JavaThread exit
1858     // should be done executing Java code by the time we get here.
1859     assert(!this->has_last_Java_frame(),
1860            "should not have a Java frame when detaching or exiting");
1861     ObjectSynchronizer::release_monitors_owned_by_thread(this);
1862     assert(!this->has_pending_exception(), "release_monitors should have cleared");
1863   }


1891 
1892   // We must flush any deferred card marks before removing a thread from
1893   // the list of active threads.
1894   Universe::heap()->flush_deferred_store_barrier(this);
1895   assert(deferred_card_mark().is_empty(), "Should have been flushed");
1896 
1897 #if INCLUDE_ALL_GCS
1898   // We must flush the G1-related buffers before removing a thread
1899   // from the list of active threads. We must do this after any deferred
1900   // card marks have been flushed (above) so that any entries that are
1901   // added to the thread's dirty card queue as a result are not lost.
1902   if (UseG1GC) {
1903     flush_barrier_queues();
1904   }
1905 #endif // INCLUDE_ALL_GCS
1906 
1907   log_info(os, thread)("JavaThread %s (tid: " UINTX_FORMAT ").",
1908     exit_type == JavaThread::normal_exit ? "exiting" : "detaching",
1909     os::current_thread_id());
1910 




1911   // Remove from list of active threads list, and notify VM thread if we are the last non-daemon thread
1912   Threads::remove(this);















1913 }
1914 
1915 #if INCLUDE_ALL_GCS
1916 // Flush G1-related queues.
1917 void JavaThread::flush_barrier_queues() {
1918   satb_mark_queue().flush();
1919   dirty_card_queue().flush();
1920 }
1921 
1922 void JavaThread::initialize_queues() {
1923   assert(!SafepointSynchronize::is_at_safepoint(),
1924          "we should not be at a safepoint");
1925 
1926   SATBMarkQueue& satb_queue = satb_mark_queue();
1927   SATBMarkQueueSet& satb_queue_set = satb_mark_queue_set();
1928   // The SATB queue should have been constructed with its active
1929   // field set to false.
1930   assert(!satb_queue.is_active(), "SATB queue should not be active");
1931   assert(satb_queue.is_empty(), "SATB queue should be empty");
1932   // If we are creating the thread during a marking cycle, we should


1952   if (free_handle_block() != NULL) {
1953     JNIHandleBlock* block = free_handle_block();
1954     set_free_handle_block(NULL);
1955     JNIHandleBlock::release_block(block);
1956   }
1957 
1958   // These have to be removed while this is still a valid thread.
1959   remove_stack_guard_pages();
1960 
1961   if (UseTLAB) {
1962     tlab().make_parsable(true);  // retire TLAB, if any
1963   }
1964 
1965 #if INCLUDE_ALL_GCS
1966   if (UseG1GC) {
1967     flush_barrier_queues();
1968   }
1969 #endif // INCLUDE_ALL_GCS
1970 
1971   Threads::remove(this);
1972   delete this;
1973 }
1974 
1975 
1976 
1977 
1978 JavaThread* JavaThread::active() {
1979   Thread* thread = Thread::current();
1980   if (thread->is_Java_thread()) {
1981     return (JavaThread*) thread;
1982   } else {
1983     assert(thread->is_VM_thread(), "this must be a vm thread");
1984     VM_Operation* op = ((VMThread*) thread)->vm_operation();
1985     JavaThread *ret=op == NULL ? NULL : (JavaThread *)op->calling_thread();
1986     assert(ret->is_Java_thread(), "must be a Java thread");
1987     return ret;
1988   }
1989 }
1990 
1991 bool JavaThread::is_lock_owned(address adr) const {
1992   if (Thread::is_lock_owned(adr)) return true;


2207   }
2208 
2209 
2210   // Interrupt thread so it will wake up from a potential wait()
2211   Thread::interrupt(this);
2212 }
2213 
2214 // External suspension mechanism.
2215 //
2216 // Tell the VM to suspend a thread when ever it knows that it does not hold on
2217 // to any VM_locks and it is at a transition
2218 // Self-suspension will happen on the transition out of the vm.
2219 // Catch "this" coming in from JNIEnv pointers when the thread has been freed
2220 //
2221 // Guarantees on return:
2222 //   + Target thread will not execute any new bytecode (that's why we need to
2223 //     force a safepoint)
2224 //   + Target thread will not enter any new monitors
2225 //
2226 void JavaThread::java_suspend() {
2227   { MutexLocker mu(Threads_lock);
2228     if (!Threads::includes(this) || is_exiting() || this->threadObj() == NULL) {
2229       return;
2230     }
2231   }
2232 
2233   { MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
2234     if (!is_external_suspend()) {
2235       // a racing resume has cancelled us; bail out now
2236       return;
2237     }
2238 
2239     // suspend is done
2240     uint32_t debug_bits = 0;
2241     // Warning: is_ext_suspend_completed() may temporarily drop the
2242     // SR_lock to allow the thread to reach a stable thread state if
2243     // it is currently in a transient thread state.
2244     if (is_ext_suspend_completed(false /* !called_by_wait */,
2245                                  SuspendRetryDelay, &debug_bits)) {
2246       return;
2247     }
2248   }
2249 
2250   VM_ThreadSuspend vm_suspend;
2251   VMThread::execute(&vm_suspend);


2299   // it. This would be a "bad thing (TM)" and cause the stack walker
2300   // to crash. We stay self-suspended until there are no more pending
2301   // external suspend requests.
2302   while (is_external_suspend()) {
2303     ret++;
2304     this->set_ext_suspended();
2305 
2306     // _ext_suspended flag is cleared by java_resume()
2307     while (is_ext_suspended()) {
2308       this->SR_lock()->wait(Mutex::_no_safepoint_check_flag);
2309     }
2310   }
2311 
2312   return ret;
2313 }
2314 
2315 #ifdef ASSERT
2316 // verify the JavaThread has not yet been published in the Threads::list, and
2317 // hence doesn't need protection from concurrent access at this stage
2318 void JavaThread::verify_not_published() {
2319   if (!Threads_lock->owned_by_self()) {
2320     MutexLockerEx ml(Threads_lock,  Mutex::_no_safepoint_check_flag);
2321     assert(!Threads::includes(this),
2322            "java thread shouldn't have been published yet!");
2323   } else {
2324     assert(!Threads::includes(this),
2325            "java thread shouldn't have been published yet!");
2326   }
2327 }
2328 #endif
2329 
2330 // Slow path when the native==>VM/Java barriers detect a safepoint is in
2331 // progress or when _suspend_flags is non-zero.
2332 // Current thread needs to self-suspend if there is a suspend request and/or
2333 // block if a safepoint is in progress.
2334 // Async exception ISN'T checked.
2335 // Note only the ThreadInVMfromNative transition can call this function
2336 // directly and when thread state is _thread_in_native_trans
2337 void JavaThread::check_safepoint_and_suspend_for_native_trans(JavaThread *thread) {
2338   assert(thread->thread_state() == _thread_in_native_trans, "wrong state");
2339 
2340   JavaThread *curJT = JavaThread::current();
2341   bool do_self_suspend = thread->is_external_suspend();
2342 
2343   assert(!curJT->has_last_Java_frame() || curJT->frame_anchor()->walkable(), "Unwalkable stack in native->vm transition");
2344 
2345   // If JNIEnv proxies are allowed, don't self-suspend if the target
2346   // thread is not the current thread. In older versions of jdbx, jdbx


2427   check_special_condition_for_native_trans(thread);
2428 
2429   // Finish the transition
2430   thread->set_thread_state(_thread_in_Java);
2431 
2432   if (thread->do_critical_native_unlock()) {
2433     ThreadInVMfromJavaNoAsyncException tiv(thread);
2434     GCLocker::unlock_critical(thread);
2435     thread->clear_critical_native_unlock();
2436   }
2437 }
2438 
2439 // We need to guarantee the Threads_lock here, since resumes are not
2440 // allowed during safepoint synchronization
2441 // Can only resume from an external suspension
2442 void JavaThread::java_resume() {
2443   assert_locked_or_safepoint(Threads_lock);
2444 
2445   // Sanity check: thread is gone, has started exiting or the thread
2446   // was not externally suspended.
2447   if (!Threads::includes(this) || is_exiting() || !is_external_suspend()) {

2448     return;
2449   }
2450 
2451   MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
2452 
2453   clear_external_suspend();
2454 
2455   if (is_ext_suspended()) {
2456     clear_ext_suspended();
2457     SR_lock()->notify_all();
2458   }
2459 }
2460 
2461 size_t JavaThread::_stack_red_zone_size = 0;
2462 size_t JavaThread::_stack_yellow_zone_size = 0;
2463 size_t JavaThread::_stack_reserved_zone_size = 0;
2464 size_t JavaThread::_stack_shadow_zone_size = 0;
2465 
2466 void JavaThread::create_stack_guard_pages() {
2467   if (!os::uses_stack_guard_pages() || _stack_guard_state != stack_guard_unused) { return; }


2895 void JavaThread::print_name_on_error(outputStream* st, char *buf, int buflen) const {
2896   st->print("%s", get_thread_name_string(buf, buflen));
2897 }
2898 
2899 // Called by fatal error handler. The difference between this and
2900 // JavaThread::print() is that we can't grab lock or allocate memory.
2901 void JavaThread::print_on_error(outputStream* st, char *buf, int buflen) const {
2902   st->print("JavaThread \"%s\"", get_thread_name_string(buf, buflen));
2903   oop thread_obj = threadObj();
2904   if (thread_obj != NULL) {
2905     if (java_lang_Thread::is_daemon(thread_obj)) st->print(" daemon");
2906   }
2907   st->print(" [");
2908   st->print("%s", _get_thread_state_name(_thread_state));
2909   if (osthread()) {
2910     st->print(", id=%d", osthread()->thread_id());
2911   }
2912   st->print(", stack(" PTR_FORMAT "," PTR_FORMAT ")",
2913             p2i(stack_end()), p2i(stack_base()));
2914   st->print("]");







2915   return;
2916 }
2917 
2918 // Verification
2919 
2920 static void frame_verify(frame* f, const RegisterMap *map) { f->verify(map); }
2921 
2922 void JavaThread::verify() {
2923   // Verify oops in the thread.
2924   oops_do(&VerifyOopClosure::verify_oop, NULL);
2925 
2926   // Verify the stack frames.
2927   frames_do(frame_verify);
2928 }
2929 
2930 // CR 6300358 (sub-CR 2137150)
2931 // Most callers of this method assume that it can't return NULL but a
2932 // thread may not have a name whilst it is in the process of attaching to
2933 // the VM - see CR 6412693, and there are places where a JavaThread can be
2934 // seen prior to having it's threadObj set (eg JNI attaching threads and


3299     // a scan.
3300     cf->do_code_blob(_scanned_compiled_method);
3301   }
3302 }
3303 
3304 
3305 // ======= Threads ========
3306 
3307 // The Threads class links together all active threads, and provides
3308 // operations over all threads.  It is protected by its own Mutex
3309 // lock, which is also used in other contexts to protect thread
3310 // operations from having the thread being operated on from exiting
3311 // and going away unexpectedly (e.g., safepoint synchronization)
3312 
3313 JavaThread* Threads::_thread_list = NULL;
3314 int         Threads::_number_of_threads = 0;
3315 int         Threads::_number_of_non_daemon_threads = 0;
3316 int         Threads::_return_code = 0;
3317 int         Threads::_thread_claim_parity = 0;
3318 size_t      JavaThread::_stack_size_at_create = 0;
























3319 #ifdef ASSERT
3320 bool        Threads::_vm_complete = false;
3321 #endif
3322 



















3323 // All JavaThreads
3324 #define ALL_JAVA_THREADS(X) for (JavaThread* X = _thread_list; X; X = X->next())
3325 
3326 // All JavaThreads + all non-JavaThreads (i.e., every thread in the system)
3327 void Threads::threads_do(ThreadClosure* tc) {
3328   assert_locked_or_safepoint(Threads_lock);
3329   // ALL_JAVA_THREADS iterates through all JavaThreads
3330   ALL_JAVA_THREADS(p) {
3331     tc->do_thread(p);
3332   }
3333   // Someday we could have a table or list of all non-JavaThreads.
3334   // For now, just manually iterate through them.
3335   tc->do_thread(VMThread::vm_thread());
3336   Universe::heap()->gc_threads_do(tc);
3337   WatcherThread *wt = WatcherThread::watcher_thread();
3338   // Strictly speaking, the following NULL check isn't sufficient to make sure
3339   // the data for WatcherThread is still valid upon being examined. However,
3340   // considering that WatchThread terminates when the VM is on the way to
3341   // exit at safepoint, the chance of the above is extremely small. The right
3342   // way to prevent termination of WatcherThread would be to acquire
3343   // Terminator_lock, but we can't do that without violating the lock rank
3344   // checking in some cases.


3405   if (result.get_jint() != JNI_OK) {
3406     vm_exit_during_initialization(); // no message or exception
3407   }
3408 
3409   universe_post_module_init();
3410 }
3411 
3412 // Phase 3. final setup - set security manager, system class loader and TCCL
3413 //
3414 //     This will instantiate and set the security manager, set the system class
3415 //     loader as well as the thread context class loader.  The security manager
3416 //     and system class loader may be a custom class loaded from -Xbootclasspath/a,
3417 //     other modules or the application's classpath.
3418 static void call_initPhase3(TRAPS) {
3419   Klass* klass = SystemDictionary::resolve_or_fail(vmSymbols::java_lang_System(), true, CHECK);
3420   JavaValue result(T_VOID);
3421   JavaCalls::call_static(&result, klass, vmSymbols::initPhase3_name(),
3422                                          vmSymbols::void_method_signature(), CHECK);
3423 }
3424 
















































































































































































































3425 void Threads::initialize_java_lang_classes(JavaThread* main_thread, TRAPS) {
3426   TraceTime timer("Initialize java.lang classes", TRACETIME_LOG(Info, startuptime));
3427 
3428   if (EagerXrunInit && Arguments::init_libraries_at_startup()) {
3429     create_vm_init_libraries();
3430   }
3431 
3432   initialize_class(vmSymbols::java_lang_String(), CHECK);
3433 
3434   // Inject CompactStrings value after the static initializers for String ran.
3435   java_lang_String::set_compact_strings(CompactStrings);
3436 
3437   // Initialize java_lang.System (needed before creating the thread)
3438   initialize_class(vmSymbols::java_lang_System(), CHECK);
3439   // The VM creates & returns objects of this class. Make sure it's initialized.
3440   initialize_class(vmSymbols::java_lang_Class(), CHECK);
3441   initialize_class(vmSymbols::java_lang_ThreadGroup(), CHECK);
3442   Handle thread_group = create_initial_thread_group(CHECK);
3443   Universe::set_main_thread_group(thread_group());
3444   initialize_class(vmSymbols::java_lang_Thread(), CHECK);


3583 #if INCLUDE_JVMCI
3584   if (JVMCICounterSize > 0) {
3585     JavaThread::_jvmci_old_thread_counters = NEW_C_HEAP_ARRAY(jlong, JVMCICounterSize, mtInternal);
3586     memset(JavaThread::_jvmci_old_thread_counters, 0, sizeof(jlong) * JVMCICounterSize);
3587   } else {
3588     JavaThread::_jvmci_old_thread_counters = NULL;
3589   }
3590 #endif // INCLUDE_JVMCI
3591 
3592   // Attach the main thread to this os thread
3593   JavaThread* main_thread = new JavaThread();
3594   main_thread->set_thread_state(_thread_in_vm);
3595   main_thread->initialize_thread_current();
3596   // must do this before set_active_handles
3597   main_thread->record_stack_base_and_size();
3598   main_thread->set_active_handles(JNIHandleBlock::allocate_block());
3599 
3600   if (!main_thread->set_as_starting_thread()) {
3601     vm_shutdown_during_initialization(
3602                                       "Failed necessary internal allocation. Out of swap space");
3603     delete main_thread;
3604     *canTryAgain = false; // don't let caller call JNI_CreateJavaVM again
3605     return JNI_ENOMEM;
3606   }
3607 
3608   // Enable guard page *after* os::create_main_thread(), otherwise it would
3609   // crash Linux VM, see notes in os_linux.cpp.
3610   main_thread->create_stack_guard_pages();
3611 
3612   // Initialize Java-Level synchronization subsystem
3613   ObjectMonitor::Initialize();
3614 
3615   // Initialize global modules
3616   jint status = init_globals();
3617   if (status != JNI_OK) {
3618     delete main_thread;
3619     *canTryAgain = false; // don't let caller call JNI_CreateJavaVM again
3620     return status;
3621   }
3622 
3623   if (TRACE_INITIALIZE() != JNI_OK) {
3624     vm_exit_during_initialization("Failed to initialize tracing backend");
3625   }
3626 
3627   // Should be done after the heap is fully created
3628   main_thread->cache_global_variables();
3629 
3630   HandleMark hm;
3631 
3632   { MutexLocker mu(Threads_lock);
3633     Threads::add(main_thread);
3634   }
3635 
3636   // Any JVMTI raw monitors entered in onload will transition into
3637   // real raw monitor. VM is setup enough here for raw monitor enter.
3638   JvmtiExport::transition_pending_onload_raw_monitors();


4004   AgentLibrary* agent;
4005 
4006   for (agent = Arguments::libraries(); agent != NULL; agent = agent->next()) {
4007     OnLoadEntry_t on_load_entry = lookup_jvm_on_load(agent);
4008 
4009     if (on_load_entry != NULL) {
4010       // Invoke the JVM_OnLoad function
4011       JavaThread* thread = JavaThread::current();
4012       ThreadToNativeFromVM ttn(thread);
4013       HandleMark hm(thread);
4014       jint err = (*on_load_entry)(&main_vm, agent->options(), NULL);
4015       if (err != JNI_OK) {
4016         vm_exit_during_initialization("-Xrun library failed to init", agent->name());
4017       }
4018     } else {
4019       vm_exit_during_initialization("Could not find JVM_OnLoad function in -Xrun library", agent->name());
4020     }
4021   }
4022 }
4023 
4024 JavaThread* Threads::find_java_thread_from_java_tid(jlong java_tid) {
4025   assert(Threads_lock->owned_by_self(), "Must hold Threads_lock");
4026 
4027   JavaThread* java_thread = NULL;
4028   // Sequential search for now.  Need to do better optimization later.
4029   for (JavaThread* thread = Threads::first(); thread != NULL; thread = thread->next()) {
4030     oop tobj = thread->threadObj();
4031     if (!thread->is_exiting() &&
4032         tobj != NULL &&
4033         java_tid == java_lang_Thread::thread_id(tobj)) {
4034       java_thread = thread;
4035       break;
4036     }
4037   }
4038   return java_thread;
4039 }
4040 
4041 
4042 // Last thread running calls java.lang.Shutdown.shutdown()
4043 void JavaThread::invoke_shutdown_hooks() {
4044   HandleMark hm(this);
4045 
4046   // We could get here with a pending exception, if so clear it now.
4047   if (this->has_pending_exception()) {
4048     this->clear_pending_exception();
4049   }
4050 
4051   EXCEPTION_MARK;
4052   Klass* shutdown_klass =
4053     SystemDictionary::resolve_or_null(vmSymbols::java_lang_Shutdown(),
4054                                       THREAD);
4055   if (shutdown_klass != NULL) {
4056     // SystemDictionary::resolve_or_null will return null if there was
4057     // an exception.  If we cannot load the Shutdown class, just don't
4058     // call Shutdown.shutdown() at all.  This will mean the shutdown hooks
4059     // and finalizers (if runFinalizersOnExit is set) won't be run.
4060     // Note that if a shutdown hook was registered or runFinalizersOnExit
4061     // was called, the Shutdown class would have already been loaded


4146     VMThread::wait_for_vm_thread_exit();
4147     assert(SafepointSynchronize::is_at_safepoint(), "VM thread should exit at Safepoint");
4148     VMThread::destroy();
4149   }
4150 
4151   // clean up ideal graph printers
4152 #if defined(COMPILER2) && !defined(PRODUCT)
4153   IdealGraphPrinter::clean_up();
4154 #endif
4155 
4156   // Now, all Java threads are gone except daemon threads. Daemon threads
4157   // running Java code or in VM are stopped by the Safepoint. However,
4158   // daemon threads executing native code are still running.  But they
4159   // will be stopped at native=>Java/VM barriers. Note that we can't
4160   // simply kill or suspend them, as it is inherently deadlock-prone.
4161 
4162   VM_Exit::set_vm_exited();
4163 
4164   notify_vm_shutdown();
4165 





4166   delete thread;
4167 
4168 #if INCLUDE_JVMCI
4169   if (JVMCICounterSize > 0) {
4170     FREE_C_HEAP_ARRAY(jlong, JavaThread::_jvmci_old_thread_counters);
4171   }
4172 #endif
4173 
4174   // exit_globals() will delete tty
4175   exit_globals();
4176 
4177   LogConfiguration::finalize();
4178 
4179   return true;
4180 }
4181 
4182 
4183 jboolean Threads::is_supported_jni_version_including_1_1(jint version) {
4184   if (version == JNI_VERSION_1_1) return JNI_TRUE;
4185   return is_supported_jni_version(version);
4186 }
4187 
4188 
4189 jboolean Threads::is_supported_jni_version(jint version) {
4190   if (version == JNI_VERSION_1_2) return JNI_TRUE;
4191   if (version == JNI_VERSION_1_4) return JNI_TRUE;
4192   if (version == JNI_VERSION_1_6) return JNI_TRUE;
4193   if (version == JNI_VERSION_1_8) return JNI_TRUE;
4194   if (version == JNI_VERSION_9) return JNI_TRUE;
4195   if (version == JNI_VERSION_10) return JNI_TRUE;
4196   return JNI_FALSE;
4197 }
4198 










4199 































































































































































































































































































































































































































































































4200 void Threads::add(JavaThread* p, bool force_daemon) {
4201   // The threads lock must be owned at this point
4202   assert_locked_or_safepoint(Threads_lock);
4203 
4204   // See the comment for this method in thread.hpp for its purpose and
4205   // why it is called here.
4206   p->initialize_queues();
4207   p->set_next(_thread_list);
4208   _thread_list = p;





4209   _number_of_threads++;
4210   oop threadObj = p->threadObj();
4211   bool daemon = true;
4212   // Bootstrapping problem: threadObj can be null for initial
4213   // JavaThread (or for threads attached via JNI)
4214   if ((!force_daemon) && (threadObj == NULL || !java_lang_Thread::is_daemon(threadObj))) {
4215     _number_of_non_daemon_threads++;
4216     daemon = false;
4217   }
4218 
4219   ThreadService::add_thread(p, daemon);
4220 














4221   // Possible GC point.
4222   Events::log(p, "Thread added: " INTPTR_FORMAT, p2i(p));
4223 }
4224 
4225 void Threads::remove(JavaThread* p) {
4226 
4227   // Reclaim the objectmonitors from the omInUseList and omFreeList of the moribund thread.
4228   ObjectSynchronizer::omFlush(p);
4229 
4230   // Extra scope needed for Thread_lock, so we can check
4231   // that we do not remove thread without safepoint code notice
4232   { MutexLocker ml(Threads_lock);
4233 
4234     assert(includes(p), "p must be present");
4235 













4236     JavaThread* current = _thread_list;
4237     JavaThread* prev    = NULL;
4238 
4239     while (current != p) {
4240       prev    = current;
4241       current = current->next();
4242     }
4243 
4244     if (prev) {
4245       prev->set_next(current->next());
4246     } else {
4247       _thread_list = p->next();
4248     }

4249     _number_of_threads--;
4250     oop threadObj = p->threadObj();
4251     bool daemon = true;
4252     if (threadObj == NULL || !java_lang_Thread::is_daemon(threadObj)) {
4253       _number_of_non_daemon_threads--;
4254       daemon = false;
4255 
4256       // Only one thread left, do a notify on the Threads_lock so a thread waiting
4257       // on destroy_vm will wake up.
4258       if (number_of_non_daemon_threads() == 1) {
4259         Threads_lock->notify_all();
4260       }
4261     }
4262     ThreadService::remove_thread(p, daemon);
4263 
4264     // Make sure that safepoint code disregard this thread. This is needed since
4265     // the thread might mess around with locks after this point. This can cause it
4266     // to do callbacks into the safepoint code. However, the safepoint code is not aware
4267     // of this thread since it is removed from the queue.
4268     p->set_terminated_value();
4269   } // unlock Threads_lock
4270 
4271   // Since Events::log uses a lock, we grab it outside the Threads_lock
4272   Events::log(p, "Thread exited: " INTPTR_FORMAT, p2i(p));
4273 }
4274 
4275 // Threads_lock must be held when this is called (or must be called during a safepoint)
4276 bool Threads::includes(JavaThread* p) {
4277   assert(Threads_lock->is_locked(), "sanity check");
4278   ALL_JAVA_THREADS(q) {
4279     if (q == p) {
4280       return true;
4281     }
4282   }
4283   return false;
4284 }
4285 
4286 // Operations on the Threads list for GC.  These are not explicitly locked,
4287 // but the garbage collector must provide a safe context for them to run.
4288 // In particular, these things should never be called when the Threads_lock
4289 // is held by some other thread. (Note: the Safepoint abstraction also
4290 // uses the Threads_lock to guarantee this property. It also makes sure that
4291 // all threads gets blocked when exiting or starting).
4292 
4293 void Threads::oops_do(OopClosure* f, CodeBlobClosure* cf) {
4294   ALL_JAVA_THREADS(p) {
4295     p->oops_do(f, cf);
4296   }
4297   VMThread::vm_thread()->oops_do(f, cf);
4298 }
4299 
4300 void Threads::change_thread_claim_parity() {
4301   // Set the new claim parity.
4302   assert(_thread_claim_parity >= 0 && _thread_claim_parity <= 2,
4303          "Not in range.");
4304   _thread_claim_parity++;
4305   if (_thread_claim_parity == 3) _thread_claim_parity = 1;


4378   ThreadHandlesClosure(void f(Metadata*)) : _f(f) {}
4379   virtual void do_thread(Thread* thread) {
4380     thread->metadata_handles_do(_f);
4381   }
4382 };
4383 
4384 void Threads::metadata_handles_do(void f(Metadata*)) {
4385   // Only walk the Handles in Thread.
4386   ThreadHandlesClosure handles_closure(f);
4387   threads_do(&handles_closure);
4388 }
4389 
4390 void Threads::deoptimized_wrt_marked_nmethods() {
4391   ALL_JAVA_THREADS(p) {
4392     p->deoptimized_wrt_marked_nmethods();
4393   }
4394 }
4395 
4396 
4397 // Get count Java threads that are waiting to enter the specified monitor.
4398 GrowableArray<JavaThread*>* Threads::get_pending_threads(int count,
4399                                                          address monitor,
4400                                                          bool doLock) {
4401   assert(doLock || SafepointSynchronize::is_at_safepoint(),
4402          "must grab Threads_lock or be at safepoint");
4403   GrowableArray<JavaThread*>* result = new GrowableArray<JavaThread*>(count);
4404 
4405   int i = 0;
4406   {
4407     MutexLockerEx ml(doLock ? Threads_lock : NULL);
4408     ALL_JAVA_THREADS(p) {
4409       if (!p->can_call_java()) continue;
4410 
4411       address pending = (address)p->current_pending_monitor();
4412       if (pending == monitor) {             // found a match
4413         if (i < count) result->append(p);   // save the first count matches
4414         i++;
4415       }
4416     }
4417   }
4418   return result;
4419 }
4420 
4421 
4422 JavaThread *Threads::owning_thread_from_monitor_owner(address owner,
4423                                                       bool doLock) {
4424   assert(doLock ||
4425          Threads_lock->owned_by_self() ||
4426          SafepointSynchronize::is_at_safepoint(),
4427          "must grab Threads_lock or be at safepoint");
4428 
4429   // NULL owner means not locked so we can skip the search
4430   if (owner == NULL) return NULL;
4431 
4432   {
4433     MutexLockerEx ml(doLock ? Threads_lock : NULL);
4434     ALL_JAVA_THREADS(p) {
4435       // first, see if owner is the address of a Java thread
4436       if (owner == (address)p) return p;
4437     }
4438   }
4439   // Cannot assert on lack of success here since this function may be
4440   // used by code that is trying to report useful problem information
4441   // like deadlock detection.
4442   if (UseHeavyMonitors) return NULL;
4443 
4444   // If we didn't find a matching Java thread and we didn't force use of
4445   // heavyweight monitors, then the owner is the stack address of the
4446   // Lock Word in the owning Java thread's stack.
4447   //
4448   JavaThread* the_owner = NULL;
4449   {
4450     MutexLockerEx ml(doLock ? Threads_lock : NULL);
4451     ALL_JAVA_THREADS(q) {
4452       if (q->is_lock_owned(owner)) {
4453         the_owner = q;
4454         break;
4455       }
4456     }
4457   }
4458   // cannot assert on lack of success here; see above comment
4459   return the_owner;
4460 }
4461 
4462 // Threads::print_on() is called at safepoint by VM_PrintThreads operation.
4463 void Threads::print_on(outputStream* st, bool print_stacks,
4464                        bool internal_format, bool print_concurrent_locks) {
4465   char buf[32];
4466   st->print_raw_cr(os::local_time_string(buf, sizeof(buf)));
4467 
4468   st->print_cr("Full thread dump %s (%s %s):",
4469                Abstract_VM_Version::vm_name(),
4470                Abstract_VM_Version::vm_release(),
4471                Abstract_VM_Version::vm_info_string());
4472   st->cr();
4473 
4474 #if INCLUDE_SERVICES
4475   // Dump concurrent locks
4476   ConcurrentLocksDump concurrent_locks;
4477   if (print_concurrent_locks) {
4478     concurrent_locks.dump_at_safepoint();
4479   }
4480 #endif // INCLUDE_SERVICES
4481 



4482   ALL_JAVA_THREADS(p) {
4483     ResourceMark rm;
4484     p->print_on(st);
4485     if (print_stacks) {
4486       if (internal_format) {
4487         p->trace_stack();
4488       } else {
4489         p->print_stack_on(st);
4490       }
4491     }
4492     st->cr();
4493 #if INCLUDE_SERVICES
4494     if (print_concurrent_locks) {
4495       concurrent_locks.print_locks_on(p, st);
4496     }
4497 #endif // INCLUDE_SERVICES
4498   }
4499 
4500   VMThread::vm_thread()->print_on(st);
4501   st->cr();
4502   Universe::heap()->print_gc_threads_on(st);
4503   WatcherThread* wt = WatcherThread::watcher_thread();
4504   if (wt != NULL) {
4505     wt->print_on(st);
4506     st->cr();
4507   }

4508   st->flush();
4509 }
4510 































































































4511 void Threads::print_on_error(Thread* this_thread, outputStream* st, Thread* current, char* buf,
4512                              int buflen, bool* found_current) {
4513   if (this_thread != NULL) {
4514     bool is_current = (current == this_thread);
4515     *found_current = *found_current || is_current;
4516     st->print("%s", is_current ? "=>" : "  ");
4517 
4518     st->print(PTR_FORMAT, p2i(this_thread));
4519     st->print(" ");
4520     this_thread->print_on_error(st, buf, buflen);
4521     st->cr();
4522   }
4523 }
4524 
4525 class PrintOnErrorClosure : public ThreadClosure {
4526   outputStream* _st;
4527   Thread* _current;
4528   char* _buf;
4529   int _buflen;
4530   bool* _found_current;
4531  public:
4532   PrintOnErrorClosure(outputStream* st, Thread* current, char* buf,
4533                       int buflen, bool* found_current) :
4534    _st(st), _current(current), _buf(buf), _buflen(buflen), _found_current(found_current) {}
4535 
4536   virtual void do_thread(Thread* thread) {
4537     Threads::print_on_error(thread, _st, _current, _buf, _buflen, _found_current);
4538   }
4539 };
4540 
4541 // Threads::print_on_error() is called by fatal error handler. It's possible
4542 // that VM is not at safepoint and/or current thread is inside signal handler.
4543 // Don't print stack trace, as the stack may not be walkable. Don't allocate
4544 // memory (even in resource area), it might deadlock the error handler.
4545 void Threads::print_on_error(outputStream* st, Thread* current, char* buf,
4546                              int buflen) {



4547   bool found_current = false;
4548   st->print_cr("Java Threads: ( => current thread )");
4549   ALL_JAVA_THREADS(thread) {
4550     print_on_error(thread, st, current, buf, buflen, &found_current);
4551   }
4552   st->cr();
4553 
4554   st->print_cr("Other Threads:");
4555   print_on_error(VMThread::vm_thread(), st, current, buf, buflen, &found_current);
4556   print_on_error(WatcherThread::watcher_thread(), st, current, buf, buflen, &found_current);
4557 
4558   PrintOnErrorClosure print_closure(st, current, buf, buflen, &found_current);
4559   Universe::heap()->gc_threads_do(&print_closure);
4560 
4561   if (!found_current) {
4562     st->cr();
4563     st->print("=>" PTR_FORMAT " (exited) ", p2i(current));
4564     current->print_on_error(st, buf, buflen);
4565     st->cr();
4566   }
4567   st->cr();

4568   st->print_cr("Threads with active compile tasks:");
4569   print_threads_compiling(st, buf, buflen);
4570 }
4571 
4572 void Threads::print_threads_compiling(outputStream* st, char* buf, int buflen) {
4573   ALL_JAVA_THREADS(thread) {
4574     if (thread->is_Compiler_thread()) {
4575       CompilerThread* ct = (CompilerThread*) thread;
4576       if (ct->task() != NULL) {
4577         thread->print_name_on_error(st, buf, buflen);
4578         ct->task()->print(st, NULL, true, true);
4579       }
4580     }
4581   }
4582 }
4583 
4584 
4585 // Internal SpinLock and Mutex
4586 // Based on ParkEvent
4587 




  53 #include "oops/symbol.hpp"
  54 #include "oops/verifyOopClosure.hpp"
  55 #include "prims/jvm_misc.hpp"
  56 #include "prims/jvmtiExport.hpp"
  57 #include "prims/jvmtiThreadState.hpp"
  58 #include "prims/privilegedStack.hpp"
  59 #include "runtime/arguments.hpp"
  60 #include "runtime/atomic.hpp"
  61 #include "runtime/biasedLocking.hpp"
  62 #include "runtime/commandLineFlagConstraintList.hpp"
  63 #include "runtime/commandLineFlagWriteableList.hpp"
  64 #include "runtime/commandLineFlagRangeList.hpp"
  65 #include "runtime/deoptimization.hpp"
  66 #include "runtime/frame.inline.hpp"
  67 #include "runtime/globals.hpp"
  68 #include "runtime/init.hpp"
  69 #include "runtime/interfaceSupport.hpp"
  70 #include "runtime/java.hpp"
  71 #include "runtime/javaCalls.hpp"
  72 #include "runtime/jniPeriodicChecker.hpp"

  73 #include "runtime/memprofiler.hpp"
  74 #include "runtime/mutexLocker.hpp"
  75 #include "runtime/objectMonitor.hpp"
  76 #include "runtime/orderAccess.inline.hpp"
  77 #include "runtime/osThread.hpp"
  78 #include "runtime/prefetch.inline.hpp"
  79 #include "runtime/safepoint.hpp"
  80 #include "runtime/sharedRuntime.hpp"
  81 #include "runtime/statSampler.hpp"
  82 #include "runtime/stubRoutines.hpp"
  83 #include "runtime/sweeper.hpp"
  84 #include "runtime/task.hpp"
  85 #include "runtime/thread.inline.hpp"
  86 #include "runtime/threadCritical.hpp"
  87 #include "runtime/threadSMR.inline.hpp"
  88 #include "runtime/timer.hpp"
  89 #include "runtime/timerTrace.hpp"
  90 #include "runtime/vframe.hpp"
  91 #include "runtime/vframeArray.hpp"
  92 #include "runtime/vframe_hp.hpp"
  93 #include "runtime/vmThread.hpp"
  94 #include "runtime/vm_operations.hpp"
  95 #include "runtime/vm_version.hpp"
  96 #include "services/attachListener.hpp"
  97 #include "services/management.hpp"
  98 #include "services/memTracker.hpp"
  99 #include "services/threadService.hpp"
 100 #include "trace/traceMacros.hpp"
 101 #include "trace/tracing.hpp"
 102 #include "utilities/align.hpp"
 103 #include "utilities/defaultStream.hpp"
 104 #include "utilities/dtrace.hpp"
 105 #include "utilities/events.hpp"
 106 #include "utilities/macros.hpp"
 107 #include "utilities/preserveException.hpp"
 108 #include "utilities/resourceHash.hpp"
 109 #include "utilities/vmError.hpp"
 110 #if INCLUDE_ALL_GCS
 111 #include "gc/cms/concurrentMarkSweepThread.hpp"
 112 #include "gc/g1/concurrentMarkThread.inline.hpp"
 113 #include "gc/parallel/pcTasks.hpp"
 114 #endif // INCLUDE_ALL_GCS
 115 #if INCLUDE_JVMCI
 116 #include "jvmci/jvmciCompiler.hpp"
 117 #include "jvmci/jvmciRuntime.hpp"
 118 #include "logging/logHandle.hpp"
 119 #endif
 120 #ifdef COMPILER1
 121 #include "c1/c1_Compiler.hpp"
 122 #endif
 123 #ifdef COMPILER2
 124 #include "opto/c2compiler.hpp"
 125 #include "opto/idealGraphPrinter.hpp"
 126 #endif
 127 #if INCLUDE_RTM_OPT
 128 #include "runtime/rtmLocking.hpp"


 180                                                          AllocFailStrategy::RETURN_NULL);
 181     void* aligned_addr     = align_up(real_malloc_addr, alignment);
 182     assert(((uintptr_t) aligned_addr + (uintptr_t) size) <=
 183            ((uintptr_t) real_malloc_addr + (uintptr_t) aligned_size),
 184            "JavaThread alignment code overflowed allocated storage");
 185     if (aligned_addr != real_malloc_addr) {
 186       log_info(biasedlocking)("Aligned thread " INTPTR_FORMAT " to " INTPTR_FORMAT,
 187                               p2i(real_malloc_addr),
 188                               p2i(aligned_addr));
 189     }
 190     ((Thread*) aligned_addr)->_real_malloc_address = real_malloc_addr;
 191     return aligned_addr;
 192   } else {
 193     return throw_excpt? AllocateHeap(size, flags, CURRENT_PC)
 194                        : AllocateHeap(size, flags, CURRENT_PC, AllocFailStrategy::RETURN_NULL);
 195   }
 196 }
 197 
 198 void Thread::operator delete(void* p) {
 199   if (UseBiasedLocking) {
 200     FreeHeap(((Thread*) p)->_real_malloc_address);

 201   } else {
 202     FreeHeap(p);
 203   }
 204 }
 205 
 206 void JavaThread::smr_delete() {
 207   if (_on_thread_list) {
 208     Threads::smr_delete(this);
 209   } else {
 210     delete this;
 211   }
 212 }
 213 
 214 // Base class for all threads: VMThread, WatcherThread, ConcurrentMarkSweepThread,
 215 // JavaThread
 216 
 217 
 218 Thread::Thread() {
 219   // stack and get_thread
 220   set_stack_base(NULL);
 221   set_stack_size(0);
 222   set_self_raw_id(0);
 223   set_lgrp_id(-1);
 224   DEBUG_ONLY(clear_suspendible_thread();)
 225 
 226   // allocated data structures
 227   set_osthread(NULL);
 228   set_resource_area(new (mtThread)ResourceArea());
 229   DEBUG_ONLY(_current_resource_mark = NULL;)
 230   set_handle_area(new (mtThread) HandleArea(NULL));
 231   set_metadata_handles(new (ResourceObj::C_HEAP, mtClass) GrowableArray<Metadata*>(30, true));
 232   set_active_handles(NULL);
 233   set_free_handle_block(NULL);
 234   set_last_handle_mark(NULL);
 235 
 236   // This initial value ==> never claimed.
 237   _oops_do_parity = 0;
 238   _threads_hazard_ptr = NULL;
 239   _nested_threads_hazard_ptr = NULL;
 240   _nested_threads_hazard_ptr_cnt = 0;
 241 
 242   // the handle mark links itself to last_handle_mark
 243   new HandleMark(this);
 244 
 245   // plain initialization
 246   debug_only(_owned_locks = NULL;)
 247   debug_only(_allow_allocation_count = 0;)
 248   NOT_PRODUCT(_allow_safepoint_count = 0;)
 249   NOT_PRODUCT(_skip_gcalot = false;)
 250   _jvmti_env_iteration_count = 0;
 251   set_allocated_bytes(0);
 252   _vm_operation_started_count = 0;
 253   _vm_operation_completed_count = 0;
 254   _current_pending_monitor = NULL;
 255   _current_pending_monitor_is_from_java = true;
 256   _current_waiting_monitor = NULL;
 257   _num_nested_signal = 0;
 258   omFreeList = NULL;
 259   omFreeCount = 0;
 260   omFreeProvision = 32;


 392   _SR_lock = NULL;
 393 
 394   // osthread() can be NULL, if creation of thread failed.
 395   if (osthread() != NULL) os::free_thread(osthread());
 396 
 397   // clear Thread::current if thread is deleting itself.
 398   // Needed to ensure JNI correctly detects non-attached threads.
 399   if (this == Thread::current()) {
 400     clear_thread_current();
 401   }
 402 
 403   CHECK_UNHANDLED_OOPS_ONLY(if (CheckUnhandledOops) delete unhandled_oops();)
 404 }
 405 
 406 // NOTE: dummy function for assertion purpose.
 407 void Thread::run() {
 408   ShouldNotReachHere();
 409 }
 410 
 411 #ifdef ASSERT
 412 // A JavaThread is considered "dangling" if it is not the current
 413 // thread, has been added the Threads list, the system is not at a
 414 // safepoint and the Thread is not "protected".
 415 //
 416 void Thread::check_for_dangling_thread_pointer(Thread *thread) {
 417   assert(!thread->is_Java_thread() || Thread::current() == thread ||
 418          !((JavaThread *) thread)->on_thread_list() ||
 419          SafepointSynchronize::is_at_safepoint() ||
 420          Threads::is_a_protected_JavaThread_with_lock((JavaThread *) thread),
 421          "possibility of dangling Thread pointer");
 422 }
 423 #endif
 424 
 425 ThreadPriority Thread::get_priority(const Thread* const thread) {
 426   ThreadPriority priority;
 427   // Can return an error!
 428   (void)os::get_priority(thread, priority);
 429   assert(MinPriority <= priority && priority <= MaxPriority, "non-Java priority found");
 430   return priority;
 431 }
 432 
 433 void Thread::set_priority(Thread* thread, ThreadPriority priority) {
 434   debug_only(check_for_dangling_thread_pointer(thread);)
 435   // Can return an error!
 436   (void)os::set_priority(thread, priority);
 437 }
 438 
 439 
 440 void Thread::start(Thread* thread) {


 732 
 733     if (!pending) {
 734       // A cancelled suspend request is the only false return from
 735       // is_ext_suspend_completed() that keeps us from staying in the
 736       // retry loop.
 737       *bits |= 0x00080000;
 738       return false;
 739     }
 740 
 741     if (is_suspended) {
 742       *bits |= 0x00100000;
 743       return true;
 744     }
 745   } // end retry loop
 746 
 747   // thread did not suspend after all our retries
 748   *bits |= 0x00200000;
 749   return false;
 750 }
 751 
 752 // Called from API entry points which perform stack walking. If the
 753 // associated JavaThread is the current thread, then wait_for_suspend
 754 // is not used. Otherwise, it determines if we should wait for the
 755 // "other" thread to complete external suspension. (NOTE: in future
 756 // releases the suspension mechanism should be reimplemented so this
 757 // is not necessary.)
 758 //
 759 bool
 760 JavaThread::is_thread_fully_suspended(bool wait_for_suspend, uint32_t *bits) {
 761   if (this != JavaThread::current()) {
 762     // "other" threads require special handling.
 763     if (wait_for_suspend) {
 764       // We are allowed to wait for the external suspend to complete
 765       // so give the other thread a chance to get suspended.
 766       if (!wait_for_ext_suspend_completion(SuspendRetryCount,
 767                                            SuspendRetryDelay, bits)) {
 768         // Didn't make it so let the caller know.
 769         return false;
 770       }
 771     }
 772     // We aren't allowed to wait for the external suspend to complete
 773     // so if the other thread isn't externally suspended we need to
 774     // let the caller know.
 775     else if (!is_ext_suspend_completed_with_lock(bits)) {
 776       return false;
 777     }
 778   }
 779 
 780   return true;
 781 }
 782 
 783 #ifndef PRODUCT
 784 void JavaThread::record_jump(address target, address instr, const char* file,
 785                              int line) {
 786 
 787   // This should not need to be atomic as the only way for simultaneous
 788   // updates is via interrupts. Even then this should be rare or non-existent
 789   // and we don't care that much anyway.
 790 
 791   int index = _jmp_ring_index;
 792   _jmp_ring_index = (index + 1) & (jump_ring_buffer_size - 1);
 793   _jmp_ring[index]._target = (intptr_t) target;
 794   _jmp_ring[index]._instruction = (intptr_t) instr;
 795   _jmp_ring[index]._file = file;
 796   _jmp_ring[index]._line = line;
 797 }
 798 #endif // PRODUCT
 799 
 800 void Thread::interrupt(Thread* thread) {
 801   debug_only(check_for_dangling_thread_pointer(thread);)
 802   os::interrupt(thread);


 841 void Thread::metadata_handles_do(void f(Metadata*)) {
 842   // Only walk the Handles in Thread.
 843   if (metadata_handles() != NULL) {
 844     for (int i = 0; i< metadata_handles()->length(); i++) {
 845       f(metadata_handles()->at(i));
 846     }
 847   }
 848 }
 849 
 850 void Thread::print_on(outputStream* st) const {
 851   // get_priority assumes osthread initialized
 852   if (osthread() != NULL) {
 853     int os_prio;
 854     if (os::get_native_priority(this, &os_prio) == OS_OK) {
 855       st->print("os_prio=%d ", os_prio);
 856     }
 857     st->print("tid=" INTPTR_FORMAT " ", p2i(this));
 858     ext().print_on(st);
 859     osthread()->print_on(st);
 860   }
 861   if (_threads_hazard_ptr != NULL) {
 862     st->print("_threads_hazard_ptr=" INTPTR_FORMAT, p2i(_threads_hazard_ptr));
 863   }
 864   if (_nested_threads_hazard_ptr != NULL) {
 865     print_nested_threads_hazard_ptrs_on(st);
 866   }
 867   st->print(" ");
 868   debug_only(if (WizardMode) print_owned_locks_on(st);)
 869 }
 870 
 871 void Thread::print_nested_threads_hazard_ptrs_on(outputStream* st) const {
 872   assert(_nested_threads_hazard_ptr != NULL, "must be set to print");
 873 
 874   if (EnableThreadSMRStatistics) {
 875     st->print(", _nested_threads_hazard_ptr_cnt=%u", _nested_threads_hazard_ptr_cnt);
 876   }
 877   st->print(", _nested_threads_hazard_ptrs=");
 878   for (NestedThreadsList* node = _nested_threads_hazard_ptr; node != NULL;
 879        node = node->next()) {
 880     if (node != _nested_threads_hazard_ptr) {
 881       // First node does not need a comma-space separator.
 882       st->print(", ");
 883     }
 884     st->print(INTPTR_FORMAT, p2i(node->t_list()));
 885   }
 886 }
 887 
 888 // Thread::print_on_error() is called by fatal error handler. Don't use
 889 // any lock or allocate memory.
 890 void Thread::print_on_error(outputStream* st, char* buf, int buflen) const {
 891   assert(!(is_Compiler_thread() || is_Java_thread()), "Can't call name() here if it allocates");
 892 
 893   if (is_VM_thread())                 { st->print("VMThread"); }
 894   else if (is_GC_task_thread())       { st->print("GCTaskThread"); }
 895   else if (is_Watcher_thread())       { st->print("WatcherThread"); }
 896   else if (is_ConcurrentGC_thread())  { st->print("ConcurrentGCThread"); }
 897   else                                { st->print("Thread"); }
 898 
 899   if (is_Named_thread()) {
 900     st->print(" \"%s\"", name());
 901   }
 902 
 903   st->print(" [stack: " PTR_FORMAT "," PTR_FORMAT "]",
 904             p2i(stack_end()), p2i(stack_base()));
 905 
 906   if (osthread()) {
 907     st->print(" [id=%d]", osthread()->thread_id());
 908   }
 909 
 910   if (_threads_hazard_ptr != NULL) {
 911     st->print(" _threads_hazard_ptr=" INTPTR_FORMAT, p2i(_threads_hazard_ptr));
 912   }
 913   if (_nested_threads_hazard_ptr != NULL) {
 914     print_nested_threads_hazard_ptrs_on(st);
 915   }
 916 }
 917 
 918 void Thread::print_value_on(outputStream* st) const {
 919   if (is_Named_thread()) {
 920     st->print(" \"%s\" ", name());
 921   }
 922   st->print(INTPTR_FORMAT, p2i(this));   // print address
 923 }
 924 
 925 #ifdef ASSERT
 926 void Thread::print_owned_locks_on(outputStream* st) const {
 927   Monitor *cur = _owned_locks;
 928   if (cur == NULL) {
 929     st->print(" (no locks) ");
 930   } else {
 931     st->print_cr(" Locks owned:");
 932     while (cur) {
 933       cur->print_on(st);
 934       cur = cur->next();
 935     }
 936   }
 937 }
 938 
 939 static int ref_use_count  = 0;
 940 
 941 bool Thread::owns_locks_but_compiled_lock() const {
 942   for (Monitor *cur = _owned_locks; cur; cur = cur->next()) {
 943     if (cur != Compile_lock) return true;
 944   }
 945   return false;
 946 }
 947 
 948 
 949 #endif
 950 
 951 #ifndef PRODUCT
 952 
 953 // The flag: potential_vm_operation notifies if this particular safepoint state could potentially
 954 // invoke the vm-thread (e.g., an oop allocation). In that case, we also have to make sure that
 955 // no threads which allow_vm_block's are held
 956 void Thread::check_for_valid_safepoint_state(bool potential_vm_operation) {
 957   // Check if current thread is allowed to block at a safepoint
 958   if (!(_allow_safepoint_count == 0)) {
 959     fatal("Possible safepoint reached by thread that does not allow it");
 960   }
 961   if (is_Java_thread() && ((JavaThread*)this)->thread_state() != _thread_in_vm) {
 962     fatal("LEAF method calling lock?");
 963   }
 964 
 965 #ifdef ASSERT
 966   if (potential_vm_operation && is_Java_thread()
 967       && !Universe::is_bootstrapping()) {
 968     // Make sure we do not hold any locks that the VM thread also uses.
 969     // This could potentially lead to deadlocks
 970     for (Monitor *cur = _owned_locks; cur; cur = cur->next()) {
 971       // Threads_lock is special, since the safepoint synchronization will not start before this is
 972       // acquired. Hence, a JavaThread cannot be holding it at a safepoint. So is VMOperationRequest_lock,
 973       // since it is used to transfer control between JavaThreads and the VMThread
 974       // Do not *exclude* any locks unless you are absolutely sure it is correct. Ask someone else first!


1460 
1461 void WatcherThread::print_on(outputStream* st) const {
1462   st->print("\"%s\" ", name());
1463   Thread::print_on(st);
1464   st->cr();
1465 }
1466 
1467 // ======= JavaThread ========
1468 
1469 #if INCLUDE_JVMCI
1470 
1471 jlong* JavaThread::_jvmci_old_thread_counters;
1472 
1473 bool jvmci_counters_include(JavaThread* thread) {
1474   oop threadObj = thread->threadObj();
1475   return !JVMCICountersExcludeCompiler || !thread->is_Compiler_thread();
1476 }
1477 
1478 void JavaThread::collect_counters(typeArrayOop array) {
1479   if (JVMCICounterSize > 0) {
1480     // dcubed - Looks like the Threads_lock is for stable access
1481     // to _jvmci_old_thread_counters and _jvmci_counters.
1482     MutexLocker tl(Threads_lock);
1483     JavaThreadIteratorWithHandle jtiwh;
1484     for (int i = 0; i < array->length(); i++) {
1485       array->long_at_put(i, _jvmci_old_thread_counters[i]);
1486     }
1487     for (; JavaThread *tp = jtiwh.next(); ) {
1488       if (jvmci_counters_include(tp)) {
1489         for (int i = 0; i < array->length(); i++) {
1490           array->long_at_put(i, array->long_at(i) + tp->_jvmci_counters[i]);
1491         }
1492       }
1493     }
1494   }
1495 }
1496 
1497 #endif // INCLUDE_JVMCI
1498 
1499 // A JavaThread is a normal Java thread
1500 
1501 void JavaThread::initialize() {
1502   // Initialize fields
1503 
1504   set_saved_exception_pc(NULL);
1505   set_threadObj(NULL);
1506   _anchor.clear();
1507   set_entry_point(NULL);
1508   set_jni_functions(jni_functions());
1509   set_callee_target(NULL);
1510   set_vm_result(NULL);
1511   set_vm_result_2(NULL);
1512   set_vframe_array_head(NULL);
1513   set_vframe_array_last(NULL);
1514   set_deferred_locals(NULL);
1515   set_deopt_mark(NULL);
1516   set_deopt_compiled_method(NULL);
1517   clear_must_deopt_id();
1518   set_monitor_chunks(NULL);
1519   set_next(NULL);
1520   _on_thread_list = false;
1521   set_thread_state(_thread_new);
1522   _terminated = _not_terminated;
1523   _privileged_stack_top = NULL;
1524   _array_for_gc = NULL;
1525   _suspend_equivalent = false;
1526   _in_deopt_handler = 0;
1527   _doing_unsafe_access = false;
1528   _stack_guard_state = stack_guard_unused;
1529 #if INCLUDE_JVMCI
1530   _pending_monitorenter = false;
1531   _pending_deoptimization = -1;
1532   _pending_failed_speculation = NULL;
1533   _pending_transfer_to_interpreter = false;
1534   _adjusting_comp_level = false;
1535   _jvmci._alternate_call_target = NULL;
1536   assert(_jvmci._implicit_exception_pc == NULL, "must be");
1537   if (JVMCICounterSize > 0) {
1538     _jvmci_counters = NEW_C_HEAP_ARRAY(jlong, JVMCICounterSize, mtInternal);
1539     memset(_jvmci_counters, 0, sizeof(jlong) * JVMCICounterSize);
1540   } else {


1777 void JavaThread::thread_main_inner() {
1778   assert(JavaThread::current() == this, "sanity check");
1779   assert(this->threadObj() != NULL, "just checking");
1780 
1781   // Execute thread entry point unless this thread has a pending exception
1782   // or has been stopped before starting.
1783   // Note: Due to JVM_StopThread we can have pending exceptions already!
1784   if (!this->has_pending_exception() &&
1785       !java_lang_Thread::is_stillborn(this->threadObj())) {
1786     {
1787       ResourceMark rm(this);
1788       this->set_native_thread_name(this->get_thread_name());
1789     }
1790     HandleMark hm(this);
1791     this->entry_point()(this, this);
1792   }
1793 
1794   DTRACE_THREAD_PROBE(stop, this);
1795 
1796   this->exit(false);
1797   this->smr_delete();
1798 }
1799 
1800 
1801 static void ensure_join(JavaThread* thread) {
1802   // We do not need to grab the Threads_lock, since we are operating on ourself.
1803   Handle threadObj(thread, thread->threadObj());
1804   assert(threadObj.not_null(), "java thread object must exist");
1805   ObjectLocker lock(threadObj, thread);
1806   // Ignore pending exception (ThreadDeath), since we are exiting anyway
1807   thread->clear_pending_exception();
1808   // Thread is exiting. So set thread_status field in  java.lang.Thread class to TERMINATED.
1809   java_lang_Thread::set_thread_status(threadObj(), java_lang_Thread::TERMINATED);
1810   // Clear the native thread instance - this makes isAlive return false and allows the join()
1811   // to complete once we've done the notify_all below
1812   java_lang_Thread::set_thread(threadObj(), NULL);
1813   lock.notify_all(thread);
1814   // Ignore pending exception (ThreadDeath), since we are exiting anyway
1815   thread->clear_pending_exception();
1816 }
1817 
1818 
1819 // For any new cleanup additions, please check to see if they need to be applied to
1820 // cleanup_failed_attach_current_thread as well.
1821 void JavaThread::exit(bool destroy_vm, ExitType exit_type) {
1822   assert(this == JavaThread::current(), "thread consistency check");
1823 
1824   elapsedTimer _timer_exit_phase1;
1825   elapsedTimer _timer_exit_phase2;
1826   elapsedTimer _timer_exit_phase3;
1827   elapsedTimer _timer_exit_phase4;
1828 
1829   if (log_is_enabled(Debug, os, thread, timer)) {
1830     _timer_exit_phase1.start();
1831   }
1832 
1833   HandleMark hm(this);
1834   Handle uncaught_exception(this, this->pending_exception());
1835   this->clear_pending_exception();
1836   Handle threadObj(this, this->threadObj());
1837   assert(threadObj.not_null(), "Java thread object should be created");
1838 
1839   // FIXIT: This code should be moved into else part, when reliable 1.2/1.3 check is in place
1840   {
1841     EXCEPTION_MARK;
1842 
1843     CLEAR_PENDING_EXCEPTION;
1844   }
1845   if (!destroy_vm) {
1846     if (uncaught_exception.not_null()) {
1847       EXCEPTION_MARK;
1848       // Call method Thread.dispatchUncaughtException().
1849       Klass* thread_klass = SystemDictionary::Thread_klass();
1850       JavaValue result(T_VOID);
1851       JavaCalls::call_virtual(&result,
1852                               threadObj, thread_klass,


1912         // Implied else:
1913         // Things get a little tricky here. We have a pending external
1914         // suspend request, but we are holding the SR_lock so we
1915         // can't just self-suspend. So we temporarily drop the lock
1916         // and then self-suspend.
1917       }
1918 
1919       ThreadBlockInVM tbivm(this);
1920       java_suspend_self();
1921 
1922       // We're done with this suspend request, but we have to loop around
1923       // and check again. Eventually we will get SR_lock without a pending
1924       // external suspend request and will be able to mark ourselves as
1925       // exiting.
1926     }
1927     // no more external suspends are allowed at this point
1928   } else {
1929     // before_exit() has already posted JVMTI THREAD_END events
1930   }
1931 
1932   if (log_is_enabled(Debug, os, thread, timer)) {
1933     _timer_exit_phase1.stop();
1934     _timer_exit_phase2.start();
1935   }
1936   // Notify waiters on thread object. This has to be done after exit() is called
1937   // on the thread (if the thread is the last thread in a daemon ThreadGroup the
1938   // group should have the destroyed bit set before waiters are notified).
1939   ensure_join(this);
1940   assert(!this->has_pending_exception(), "ensure_join should have cleared");
1941 
1942   if (log_is_enabled(Debug, os, thread, timer)) {
1943     _timer_exit_phase2.stop();
1944     _timer_exit_phase3.start();
1945   }
1946   // 6282335 JNI DetachCurrentThread spec states that all Java monitors
1947   // held by this thread must be released. The spec does not distinguish
1948   // between JNI-acquired and regular Java monitors. We can only see
1949   // regular Java monitors here if monitor enter-exit matching is broken.
1950   //
1951   // Optionally release any monitors for regular JavaThread exits. This
1952   // is provided as a work around for any bugs in monitor enter-exit
1953   // matching. This can be expensive so it is not enabled by default.
1954   //
1955   // ensure_join() ignores IllegalThreadStateExceptions, and so does
1956   // ObjectSynchronizer::release_monitors_owned_by_thread().
1957   if (exit_type == jni_detach || ObjectMonitor::Knob_ExitRelease) {
1958     // Sanity check even though JNI DetachCurrentThread() would have
1959     // returned JNI_ERR if there was a Java frame. JavaThread exit
1960     // should be done executing Java code by the time we get here.
1961     assert(!this->has_last_Java_frame(),
1962            "should not have a Java frame when detaching or exiting");
1963     ObjectSynchronizer::release_monitors_owned_by_thread(this);
1964     assert(!this->has_pending_exception(), "release_monitors should have cleared");
1965   }


1993 
1994   // We must flush any deferred card marks before removing a thread from
1995   // the list of active threads.
1996   Universe::heap()->flush_deferred_store_barrier(this);
1997   assert(deferred_card_mark().is_empty(), "Should have been flushed");
1998 
1999 #if INCLUDE_ALL_GCS
2000   // We must flush the G1-related buffers before removing a thread
2001   // from the list of active threads. We must do this after any deferred
2002   // card marks have been flushed (above) so that any entries that are
2003   // added to the thread's dirty card queue as a result are not lost.
2004   if (UseG1GC) {
2005     flush_barrier_queues();
2006   }
2007 #endif // INCLUDE_ALL_GCS
2008 
2009   log_info(os, thread)("JavaThread %s (tid: " UINTX_FORMAT ").",
2010     exit_type == JavaThread::normal_exit ? "exiting" : "detaching",
2011     os::current_thread_id());
2012 
2013   if (log_is_enabled(Debug, os, thread, timer)) {
2014     _timer_exit_phase3.stop();
2015     _timer_exit_phase4.start();
2016   }
2017   // Remove from list of active threads list, and notify VM thread if we are the last non-daemon thread
2018   Threads::remove(this);
2019 
2020   if (log_is_enabled(Debug, os, thread, timer)) {
2021     _timer_exit_phase4.stop();
2022     ResourceMark rm(this);
2023     log_debug(os, thread, timer)("name='%s'"
2024                                  ", exit-phase1=" JLONG_FORMAT
2025                                  ", exit-phase2=" JLONG_FORMAT
2026                                  ", exit-phase3=" JLONG_FORMAT
2027                                  ", exit-phase4=" JLONG_FORMAT,
2028                                  get_thread_name(),
2029                                  _timer_exit_phase1.milliseconds(),
2030                                  _timer_exit_phase2.milliseconds(),
2031                                  _timer_exit_phase3.milliseconds(),
2032                                  _timer_exit_phase4.milliseconds());
2033   }
2034 }
2035 
2036 #if INCLUDE_ALL_GCS
2037 // Flush G1-related queues.
2038 void JavaThread::flush_barrier_queues() {
2039   satb_mark_queue().flush();
2040   dirty_card_queue().flush();
2041 }
2042 
2043 void JavaThread::initialize_queues() {
2044   assert(!SafepointSynchronize::is_at_safepoint(),
2045          "we should not be at a safepoint");
2046 
2047   SATBMarkQueue& satb_queue = satb_mark_queue();
2048   SATBMarkQueueSet& satb_queue_set = satb_mark_queue_set();
2049   // The SATB queue should have been constructed with its active
2050   // field set to false.
2051   assert(!satb_queue.is_active(), "SATB queue should not be active");
2052   assert(satb_queue.is_empty(), "SATB queue should be empty");
2053   // If we are creating the thread during a marking cycle, we should


2073   if (free_handle_block() != NULL) {
2074     JNIHandleBlock* block = free_handle_block();
2075     set_free_handle_block(NULL);
2076     JNIHandleBlock::release_block(block);
2077   }
2078 
2079   // These have to be removed while this is still a valid thread.
2080   remove_stack_guard_pages();
2081 
2082   if (UseTLAB) {
2083     tlab().make_parsable(true);  // retire TLAB, if any
2084   }
2085 
2086 #if INCLUDE_ALL_GCS
2087   if (UseG1GC) {
2088     flush_barrier_queues();
2089   }
2090 #endif // INCLUDE_ALL_GCS
2091 
2092   Threads::remove(this);
2093   this->smr_delete();
2094 }
2095 
2096 
2097 
2098 
2099 JavaThread* JavaThread::active() {
2100   Thread* thread = Thread::current();
2101   if (thread->is_Java_thread()) {
2102     return (JavaThread*) thread;
2103   } else {
2104     assert(thread->is_VM_thread(), "this must be a vm thread");
2105     VM_Operation* op = ((VMThread*) thread)->vm_operation();
2106     JavaThread *ret=op == NULL ? NULL : (JavaThread *)op->calling_thread();
2107     assert(ret->is_Java_thread(), "must be a Java thread");
2108     return ret;
2109   }
2110 }
2111 
2112 bool JavaThread::is_lock_owned(address adr) const {
2113   if (Thread::is_lock_owned(adr)) return true;


2328   }
2329 
2330 
2331   // Interrupt thread so it will wake up from a potential wait()
2332   Thread::interrupt(this);
2333 }
2334 
2335 // External suspension mechanism.
2336 //
2337 // Tell the VM to suspend a thread when ever it knows that it does not hold on
2338 // to any VM_locks and it is at a transition
2339 // Self-suspension will happen on the transition out of the vm.
2340 // Catch "this" coming in from JNIEnv pointers when the thread has been freed
2341 //
2342 // Guarantees on return:
2343 //   + Target thread will not execute any new bytecode (that's why we need to
2344 //     force a safepoint)
2345 //   + Target thread will not enter any new monitors
2346 //
2347 void JavaThread::java_suspend() {
2348   ThreadsListHandle tlh;
2349   if (!tlh.includes(this) || threadObj() == NULL || is_exiting()) {
2350     return;
2351   }

2352 
2353   { MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
2354     if (!is_external_suspend()) {
2355       // a racing resume has cancelled us; bail out now
2356       return;
2357     }
2358 
2359     // suspend is done
2360     uint32_t debug_bits = 0;
2361     // Warning: is_ext_suspend_completed() may temporarily drop the
2362     // SR_lock to allow the thread to reach a stable thread state if
2363     // it is currently in a transient thread state.
2364     if (is_ext_suspend_completed(false /* !called_by_wait */,
2365                                  SuspendRetryDelay, &debug_bits)) {
2366       return;
2367     }
2368   }
2369 
2370   VM_ThreadSuspend vm_suspend;
2371   VMThread::execute(&vm_suspend);


2419   // it. This would be a "bad thing (TM)" and cause the stack walker
2420   // to crash. We stay self-suspended until there are no more pending
2421   // external suspend requests.
2422   while (is_external_suspend()) {
2423     ret++;
2424     this->set_ext_suspended();
2425 
2426     // _ext_suspended flag is cleared by java_resume()
2427     while (is_ext_suspended()) {
2428       this->SR_lock()->wait(Mutex::_no_safepoint_check_flag);
2429     }
2430   }
2431 
2432   return ret;
2433 }
2434 
2435 #ifdef ASSERT
2436 // verify the JavaThread has not yet been published in the Threads::list, and
2437 // hence doesn't need protection from concurrent access at this stage
2438 void JavaThread::verify_not_published() {
2439   ThreadsListHandle tlh;
2440   assert(!tlh.includes(this), "JavaThread shouldn't have been published yet!");






2441 }
2442 #endif
2443 
2444 // Slow path when the native==>VM/Java barriers detect a safepoint is in
2445 // progress or when _suspend_flags is non-zero.
2446 // Current thread needs to self-suspend if there is a suspend request and/or
2447 // block if a safepoint is in progress.
2448 // Async exception ISN'T checked.
2449 // Note only the ThreadInVMfromNative transition can call this function
2450 // directly and when thread state is _thread_in_native_trans
2451 void JavaThread::check_safepoint_and_suspend_for_native_trans(JavaThread *thread) {
2452   assert(thread->thread_state() == _thread_in_native_trans, "wrong state");
2453 
2454   JavaThread *curJT = JavaThread::current();
2455   bool do_self_suspend = thread->is_external_suspend();
2456 
2457   assert(!curJT->has_last_Java_frame() || curJT->frame_anchor()->walkable(), "Unwalkable stack in native->vm transition");
2458 
2459   // If JNIEnv proxies are allowed, don't self-suspend if the target
2460   // thread is not the current thread. In older versions of jdbx, jdbx


2541   check_special_condition_for_native_trans(thread);
2542 
2543   // Finish the transition
2544   thread->set_thread_state(_thread_in_Java);
2545 
2546   if (thread->do_critical_native_unlock()) {
2547     ThreadInVMfromJavaNoAsyncException tiv(thread);
2548     GCLocker::unlock_critical(thread);
2549     thread->clear_critical_native_unlock();
2550   }
2551 }
2552 
2553 // We need to guarantee the Threads_lock here, since resumes are not
2554 // allowed during safepoint synchronization
2555 // Can only resume from an external suspension
2556 void JavaThread::java_resume() {
2557   assert_locked_or_safepoint(Threads_lock);
2558 
2559   // Sanity check: thread is gone, has started exiting or the thread
2560   // was not externally suspended.
2561   ThreadsListHandle tlh;
2562   if (!tlh.includes(this) || is_exiting() || !is_external_suspend()) {
2563     return;
2564   }
2565 
2566   MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
2567 
2568   clear_external_suspend();
2569 
2570   if (is_ext_suspended()) {
2571     clear_ext_suspended();
2572     SR_lock()->notify_all();
2573   }
2574 }
2575 
2576 size_t JavaThread::_stack_red_zone_size = 0;
2577 size_t JavaThread::_stack_yellow_zone_size = 0;
2578 size_t JavaThread::_stack_reserved_zone_size = 0;
2579 size_t JavaThread::_stack_shadow_zone_size = 0;
2580 
2581 void JavaThread::create_stack_guard_pages() {
2582   if (!os::uses_stack_guard_pages() || _stack_guard_state != stack_guard_unused) { return; }


3010 void JavaThread::print_name_on_error(outputStream* st, char *buf, int buflen) const {
3011   st->print("%s", get_thread_name_string(buf, buflen));
3012 }
3013 
3014 // Called by fatal error handler. The difference between this and
3015 // JavaThread::print() is that we can't grab lock or allocate memory.
3016 void JavaThread::print_on_error(outputStream* st, char *buf, int buflen) const {
3017   st->print("JavaThread \"%s\"", get_thread_name_string(buf, buflen));
3018   oop thread_obj = threadObj();
3019   if (thread_obj != NULL) {
3020     if (java_lang_Thread::is_daemon(thread_obj)) st->print(" daemon");
3021   }
3022   st->print(" [");
3023   st->print("%s", _get_thread_state_name(_thread_state));
3024   if (osthread()) {
3025     st->print(", id=%d", osthread()->thread_id());
3026   }
3027   st->print(", stack(" PTR_FORMAT "," PTR_FORMAT ")",
3028             p2i(stack_end()), p2i(stack_base()));
3029   st->print("]");
3030 
3031   if (_threads_hazard_ptr != NULL) {
3032     st->print(" _threads_hazard_ptr=" INTPTR_FORMAT, p2i(_threads_hazard_ptr));
3033   }
3034   if (_nested_threads_hazard_ptr != NULL) {
3035     print_nested_threads_hazard_ptrs_on(st);
3036   }
3037   return;
3038 }
3039 
3040 // Verification
3041 
3042 static void frame_verify(frame* f, const RegisterMap *map) { f->verify(map); }
3043 
3044 void JavaThread::verify() {
3045   // Verify oops in the thread.
3046   oops_do(&VerifyOopClosure::verify_oop, NULL);
3047 
3048   // Verify the stack frames.
3049   frames_do(frame_verify);
3050 }
3051 
3052 // CR 6300358 (sub-CR 2137150)
3053 // Most callers of this method assume that it can't return NULL but a
3054 // thread may not have a name whilst it is in the process of attaching to
3055 // the VM - see CR 6412693, and there are places where a JavaThread can be
3056 // seen prior to having it's threadObj set (eg JNI attaching threads and


3421     // a scan.
3422     cf->do_code_blob(_scanned_compiled_method);
3423   }
3424 }
3425 
3426 
3427 // ======= Threads ========
3428 
3429 // The Threads class links together all active threads, and provides
3430 // operations over all threads.  It is protected by its own Mutex
3431 // lock, which is also used in other contexts to protect thread
3432 // operations from having the thread being operated on from exiting
3433 // and going away unexpectedly (e.g., safepoint synchronization)
3434 
3435 JavaThread*           Threads::_thread_list = NULL;
3436 int                   Threads::_number_of_threads = 0;
3437 int                   Threads::_number_of_non_daemon_threads = 0;
3438 int                   Threads::_return_code = 0;
3439 int                   Threads::_thread_claim_parity = 0;
3440 size_t                JavaThread::_stack_size_at_create = 0;
3441 Monitor*              Threads::_smr_delete_lock =
3442                           new Monitor(Monitor::special, "smr_delete_lock",
3443                                       false /* allow_vm_block */,
3444                                       Monitor::_safepoint_check_never);
3445 // The '_cnt', '_max' and '_times" fields are enabled via
3446 // -XX:+EnableThreadSMRStatistics:
3447 uint                  Threads::_smr_delete_lock_wait_cnt = 0;
3448 uint                  Threads::_smr_delete_lock_wait_max = 0;
3449 volatile jint         Threads::_smr_delete_notify = 0;
3450 volatile jint         Threads::_smr_deleted_thread_cnt = 0;
3451 volatile jint         Threads::_smr_deleted_thread_time_max = 0;
3452 volatile jint         Threads::_smr_deleted_thread_times = 0;
3453 ThreadsList* volatile Threads::_smr_java_thread_list = new ThreadsList(0);
3454 long                  Threads::_smr_java_thread_list_alloc_cnt = 1;
3455 long                  Threads::_smr_java_thread_list_free_cnt = 0;
3456 uint                  Threads::_smr_java_thread_list_max = 0;
3457 uint                  Threads::_smr_nested_thread_list_max = 0;
3458 volatile jint         Threads::_smr_tlh_cnt = 0;
3459 volatile jint         Threads::_smr_tlh_time_max = 0;
3460 volatile jint         Threads::_smr_tlh_times = 0;
3461 ThreadsList*          Threads::_smr_to_delete_list = NULL;
3462 uint                  Threads::_smr_to_delete_list_cnt = 0;
3463 uint                  Threads::_smr_to_delete_list_max = 0;
3464 
3465 #ifdef ASSERT
3466 bool                  Threads::_vm_complete = false;
3467 #endif
3468 
3469 static inline void *prefetch_and_load_ptr(void **addr, intx prefetch_interval) {
3470   Prefetch::read((void*)addr, prefetch_interval);
3471   return *addr;
3472 }
3473 
3474 // Possibly the ugliest for loop the world has seen. C++ does not allow
3475 // multiple types in the declaration section of the for loop. In this case
3476 // we are only dealing with pointers and hence can cast them. It looks ugly
3477 // but macros are ugly and therefore it's fine to make things absurdly ugly.
3478 #define DO_JAVA_THREADS(LIST, X)                                                                                          \
3479     for (JavaThread *MACRO_scan_interval = (JavaThread*)(uintptr_t)PrefetchScanIntervalInBytes,                           \
3480              *MACRO_list = (JavaThread*)(LIST),                                                                           \
3481              **MACRO_end = ((JavaThread**)((ThreadsList*)MACRO_list)->threads()) + ((ThreadsList*)MACRO_list)->length(),  \
3482              **MACRO_current_p = (JavaThread**)((ThreadsList*)MACRO_list)->threads(),                                     \
3483              *X = (JavaThread*)prefetch_and_load_ptr((void**)MACRO_current_p, (intx)MACRO_scan_interval);                 \
3484          MACRO_current_p != MACRO_end;                                                                                    \
3485          MACRO_current_p++,                                                                                               \
3486              X = (JavaThread*)prefetch_and_load_ptr((void**)MACRO_current_p, (intx)MACRO_scan_interval))
3487 
3488 // All JavaThreads
3489 #define ALL_JAVA_THREADS(X) DO_JAVA_THREADS(get_smr_java_thread_list(), X)
3490 
3491 // All JavaThreads + all non-JavaThreads (i.e., every thread in the system)
3492 void Threads::threads_do(ThreadClosure* tc) {
3493   assert_locked_or_safepoint(Threads_lock);
3494   // ALL_JAVA_THREADS iterates through all JavaThreads
3495   ALL_JAVA_THREADS(p) {
3496     tc->do_thread(p);
3497   }
3498   // Someday we could have a table or list of all non-JavaThreads.
3499   // For now, just manually iterate through them.
3500   tc->do_thread(VMThread::vm_thread());
3501   Universe::heap()->gc_threads_do(tc);
3502   WatcherThread *wt = WatcherThread::watcher_thread();
3503   // Strictly speaking, the following NULL check isn't sufficient to make sure
3504   // the data for WatcherThread is still valid upon being examined. However,
3505   // considering that WatchThread terminates when the VM is on the way to
3506   // exit at safepoint, the chance of the above is extremely small. The right
3507   // way to prevent termination of WatcherThread would be to acquire
3508   // Terminator_lock, but we can't do that without violating the lock rank
3509   // checking in some cases.


3570   if (result.get_jint() != JNI_OK) {
3571     vm_exit_during_initialization(); // no message or exception
3572   }
3573 
3574   universe_post_module_init();
3575 }
3576 
3577 // Phase 3. final setup - set security manager, system class loader and TCCL
3578 //
3579 //     This will instantiate and set the security manager, set the system class
3580 //     loader as well as the thread context class loader.  The security manager
3581 //     and system class loader may be a custom class loaded from -Xbootclasspath/a,
3582 //     other modules or the application's classpath.
3583 static void call_initPhase3(TRAPS) {
3584   Klass* klass = SystemDictionary::resolve_or_fail(vmSymbols::java_lang_System(), true, CHECK);
3585   JavaValue result(T_VOID);
3586   JavaCalls::call_static(&result, klass, vmSymbols::initPhase3_name(),
3587                                          vmSymbols::void_method_signature(), CHECK);
3588 }
3589 
3590 // Safe Memory Reclamation (SMR) support:
3591 //
3592 
3593 // Acquire a stable ThreadsList.
3594 //
3595 ThreadsList *Threads::acquire_stable_list(Thread *self, bool is_ThreadsListSetter) {
3596   assert(self != NULL, "sanity check");
3597   // acquire_stable_list_nested_path() will grab the Threads_lock
3598   // so let's make sure the ThreadsListHandle is in a safe place.
3599   // ThreadsListSetter cannot make this check on this code path.
3600   debug_only(if (!is_ThreadsListSetter && StrictSafepointChecks) self->check_for_valid_safepoint_state(/* potential_vm_operation */ false);)
3601 
3602   if (self->get_threads_hazard_ptr() == NULL) {
3603     // The typical case is first.
3604     return acquire_stable_list_fast_path(self);
3605   }
3606 
3607   // The nested case is rare.
3608   return acquire_stable_list_nested_path(self);
3609 }
3610 
3611 // Fast path (and lock free) way to acquire a stable ThreadsList.
3612 //
3613 ThreadsList *Threads::acquire_stable_list_fast_path(Thread *self) {
3614   assert(self != NULL, "sanity check");
3615   assert(self->get_threads_hazard_ptr() == NULL, "sanity check");
3616   assert(self->get_nested_threads_hazard_ptr() == NULL,
3617          "cannot have a nested hazard ptr with a NULL regular hazard ptr");
3618 
3619   ThreadsList* threads;
3620 
3621   // Stable recording of a hazard ptr for SMR. This code does not use
3622   // locks so its use of the _smr_java_thread_list & _threads_hazard_ptr
3623   // fields is racy relative to code that uses those fields with locks.
3624   // OrderAccess and Atomic functions are used to deal with those races.
3625   //
3626   while (true) {
3627     threads = get_smr_java_thread_list();
3628 
3629     // Publish a tagged hazard ptr to denote that the hazard ptr is not
3630     // yet verified as being stable. Due to the fence after the hazard
3631     // ptr write, it will be sequentially consistent w.r.t. the
3632     // sequentially consistent writes of the ThreadsList, even on
3633     // non-multiple copy atomic machines where stores can be observed
3634     // in different order from different observer threads.
3635     ThreadsList* unverified_threads = Thread::tag_hazard_ptr(threads);
3636     self->set_threads_hazard_ptr(unverified_threads);
3637 
3638     // If _smr_java_thread_list has changed, we have lost a race with
3639     // Threads::add() or Threads::remove() and have to try again.
3640     if (get_smr_java_thread_list() != threads) {
3641       continue;
3642     }
3643 
3644     // We try to remove the tag which will verify the hazard ptr as
3645     // being stable. This exchange can race with a scanning thread
3646     // which might invalidate the tagged hazard ptr to keep it from
3647     // being followed to access JavaThread ptrs. If we lose the race,
3648     // we simply retry. If we win the race, then the stable hazard
3649     // ptr is officially published.
3650     if (self->cmpxchg_threads_hazard_ptr(threads, unverified_threads) == unverified_threads) {
3651       break;
3652     }
3653   }
3654 
3655   // A stable hazard ptr has been published letting other threads know
3656   // that the ThreadsList and the JavaThreads reachable from this list
3657   // are protected and hence they should not be deleted until everyone
3658   // agrees it is safe to do so.
3659 
3660   return threads;
3661 }
3662 
3663 // Acquire a nested stable ThreadsList; this is rare so it uses
3664 // Threads_lock.
3665 //
3666 ThreadsList *Threads::acquire_stable_list_nested_path(Thread *self) {
3667   assert(self != NULL, "sanity check");
3668   assert(self->get_threads_hazard_ptr() != NULL,
3669          "cannot have a NULL regular hazard ptr when acquiring a nested hazard ptr");
3670 
3671   // The thread already has a hazard ptr (ThreadsList ref) so we need
3672   // to create a nested ThreadsListHandle with the current ThreadsList
3673   // since it might be different than our current hazard ptr. The need
3674   // for a nested ThreadsListHandle is rare so we do this while holding
3675   // the Threads_lock so we don't race with the scanning code; the code
3676   // is so much simpler this way.
3677 
3678   NestedThreadsList* node;
3679   {
3680     // Only grab the Threads_lock if we don't already own it.
3681     MutexLockerEx ml(Threads_lock->owned_by_self() ? NULL : Threads_lock);
3682     node = new NestedThreadsList(get_smr_java_thread_list());
3683     // We insert at the front of the list to match up with the delete
3684     // in release_stable_list().
3685     node->set_next(self->get_nested_threads_hazard_ptr());
3686     self->set_nested_threads_hazard_ptr(node);
3687     if (EnableThreadSMRStatistics) {
3688       self->inc_nested_threads_hazard_ptr_cnt();
3689       if (self->nested_threads_hazard_ptr_cnt() > _smr_nested_thread_list_max) {
3690         _smr_nested_thread_list_max = self->nested_threads_hazard_ptr_cnt();
3691       }
3692     }
3693   }
3694   log_debug(thread, smr)("tid=" UINTX_FORMAT ": Threads::acquire_stable_list: add NestedThreadsList node containing ThreadsList=" INTPTR_FORMAT, os::current_thread_id(), p2i(node->t_list()));
3695 
3696   return node->t_list();
3697 }
3698 
3699 // Release a stable ThreadsList.
3700 //
3701 void Threads::release_stable_list(Thread *self) {
3702   assert(self != NULL, "sanity check");
3703   // release_stable_list_nested_path() will grab the Threads_lock
3704   // so let's make sure the ThreadsListHandle is in a safe place.
3705   debug_only(if (StrictSafepointChecks) self->check_for_valid_safepoint_state(/* potential_vm_operation */ false);)
3706 
3707   if (self->get_nested_threads_hazard_ptr() == NULL) {
3708     // The typical case is first.
3709     release_stable_list_fast_path(self);
3710     return;
3711   }
3712 
3713   // The nested case is rare.
3714   release_stable_list_nested_path(self);
3715 }
3716 
3717 // Fast path way to release a stable ThreadsList. The release portion
3718 // is lock-free, but the wake up portion is not.
3719 //
3720 void Threads::release_stable_list_fast_path(Thread *self) {
3721   assert(self != NULL, "sanity check");
3722   assert(self->get_threads_hazard_ptr() != NULL, "sanity check");
3723   assert(self->get_nested_threads_hazard_ptr() == NULL,
3724          "cannot have a nested hazard ptr when releasing a regular hazard ptr");
3725 
3726   // After releasing the hazard ptr, other threads may go ahead and
3727   // free up some memory temporarily used by a ThreadsList snapshot.
3728   self->set_threads_hazard_ptr(NULL);
3729 
3730   // We use double-check locking to reduce traffic on the system
3731   // wide smr_delete_lock.
3732   if (Threads::smr_delete_notify()) {
3733     // An exiting thread might be waiting in smr_delete(); we need to
3734     // check with smr_delete_lock to be sure.
3735     release_stable_list_wake_up((char *) "regular hazard ptr");
3736   }
3737 }
3738 
3739 // Release a nested stable ThreadsList; this is rare so it uses
3740 // Threads_lock.
3741 //
3742 void Threads::release_stable_list_nested_path(Thread *self) {
3743   assert(self != NULL, "sanity check");
3744   assert(self->get_nested_threads_hazard_ptr() != NULL, "sanity check");
3745   assert(self->get_threads_hazard_ptr() != NULL,
3746          "must have a regular hazard ptr to have nested hazard ptrs");
3747 
3748   // We have a nested ThreadsListHandle so we have to release it first.
3749   // The need for a nested ThreadsListHandle is rare so we do this while
3750   // holding the Threads_lock so we don't race with the scanning code;
3751   // the code is so much simpler this way.
3752 
3753   NestedThreadsList *node;
3754   {
3755     // Only grab the Threads_lock if we don't already own it.
3756     MutexLockerEx ml(Threads_lock->owned_by_self() ? NULL : Threads_lock);
3757     // We remove from the front of the list to match up with the insert
3758     // in acquire_stable_list().
3759     node = self->get_nested_threads_hazard_ptr();
3760     self->set_nested_threads_hazard_ptr(node->next());
3761     if (EnableThreadSMRStatistics) {
3762       self->dec_nested_threads_hazard_ptr_cnt();
3763     }
3764   }
3765 
3766   // An exiting thread might be waiting in smr_delete(); we need to
3767   // check with smr_delete_lock to be sure.
3768   release_stable_list_wake_up((char *) "nested hazard ptr");
3769 
3770   log_debug(thread, smr)("tid=" UINTX_FORMAT ": Threads::release_stable_list: delete NestedThreadsList node containing ThreadsList=" INTPTR_FORMAT, os::current_thread_id(), p2i(node->t_list()));
3771 
3772   delete node;
3773 }
3774 
3775 // Wake up portion of the release stable ThreadsList protocol;
3776 // uses the smr_delete_lock().
3777 //
3778 void Threads::release_stable_list_wake_up(char *log_str) {
3779   assert(log_str != NULL, "sanity check");
3780 
3781   // Note: smr_delete_lock is held in smr_delete() for the entire
3782   // hazard ptr search so that we do not lose this notify() if
3783   // the exiting thread has to wait. That code path also holds
3784   // Threads_lock (which was grabbed before smr_delete_lock) so that
3785   // threads_do() can be called. This means the system can't start a
3786   // safepoint which means this thread can't take too long to get to
3787   // a safepoint because of being blocked on smr_delete_lock.
3788   //
3789   MonitorLockerEx ml(Threads::smr_delete_lock(), Monitor::_no_safepoint_check_flag);
3790   if (Threads::smr_delete_notify()) {
3791     // Notify any exiting JavaThreads that are waiting in smr_delete()
3792     // that we've released a ThreadsList.
3793     ml.notify_all();
3794     log_debug(thread, smr)("tid=" UINTX_FORMAT ": Threads::release_stable_list notified %s", os::current_thread_id(), log_str);
3795   }
3796 }
3797 
3798 void Threads::initialize_java_lang_classes(JavaThread* main_thread, TRAPS) {
3799   TraceTime timer("Initialize java.lang classes", TRACETIME_LOG(Info, startuptime));
3800 
3801   if (EagerXrunInit && Arguments::init_libraries_at_startup()) {
3802     create_vm_init_libraries();
3803   }
3804 
3805   initialize_class(vmSymbols::java_lang_String(), CHECK);
3806 
3807   // Inject CompactStrings value after the static initializers for String ran.
3808   java_lang_String::set_compact_strings(CompactStrings);
3809 
3810   // Initialize java_lang.System (needed before creating the thread)
3811   initialize_class(vmSymbols::java_lang_System(), CHECK);
3812   // The VM creates & returns objects of this class. Make sure it's initialized.
3813   initialize_class(vmSymbols::java_lang_Class(), CHECK);
3814   initialize_class(vmSymbols::java_lang_ThreadGroup(), CHECK);
3815   Handle thread_group = create_initial_thread_group(CHECK);
3816   Universe::set_main_thread_group(thread_group());
3817   initialize_class(vmSymbols::java_lang_Thread(), CHECK);


3956 #if INCLUDE_JVMCI
3957   if (JVMCICounterSize > 0) {
3958     JavaThread::_jvmci_old_thread_counters = NEW_C_HEAP_ARRAY(jlong, JVMCICounterSize, mtInternal);
3959     memset(JavaThread::_jvmci_old_thread_counters, 0, sizeof(jlong) * JVMCICounterSize);
3960   } else {
3961     JavaThread::_jvmci_old_thread_counters = NULL;
3962   }
3963 #endif // INCLUDE_JVMCI
3964 
3965   // Attach the main thread to this os thread
3966   JavaThread* main_thread = new JavaThread();
3967   main_thread->set_thread_state(_thread_in_vm);
3968   main_thread->initialize_thread_current();
3969   // must do this before set_active_handles
3970   main_thread->record_stack_base_and_size();
3971   main_thread->set_active_handles(JNIHandleBlock::allocate_block());
3972 
3973   if (!main_thread->set_as_starting_thread()) {
3974     vm_shutdown_during_initialization(
3975                                       "Failed necessary internal allocation. Out of swap space");
3976     main_thread->smr_delete();
3977     *canTryAgain = false; // don't let caller call JNI_CreateJavaVM again
3978     return JNI_ENOMEM;
3979   }
3980 
3981   // Enable guard page *after* os::create_main_thread(), otherwise it would
3982   // crash Linux VM, see notes in os_linux.cpp.
3983   main_thread->create_stack_guard_pages();
3984 
3985   // Initialize Java-Level synchronization subsystem
3986   ObjectMonitor::Initialize();
3987 
3988   // Initialize global modules
3989   jint status = init_globals();
3990   if (status != JNI_OK) {
3991     main_thread->smr_delete();
3992     *canTryAgain = false; // don't let caller call JNI_CreateJavaVM again
3993     return status;
3994   }
3995 
3996   if (TRACE_INITIALIZE() != JNI_OK) {
3997     vm_exit_during_initialization("Failed to initialize tracing backend");
3998   }
3999 
4000   // Should be done after the heap is fully created
4001   main_thread->cache_global_variables();
4002 
4003   HandleMark hm;
4004 
4005   { MutexLocker mu(Threads_lock);
4006     Threads::add(main_thread);
4007   }
4008 
4009   // Any JVMTI raw monitors entered in onload will transition into
4010   // real raw monitor. VM is setup enough here for raw monitor enter.
4011   JvmtiExport::transition_pending_onload_raw_monitors();


4377   AgentLibrary* agent;
4378 
4379   for (agent = Arguments::libraries(); agent != NULL; agent = agent->next()) {
4380     OnLoadEntry_t on_load_entry = lookup_jvm_on_load(agent);
4381 
4382     if (on_load_entry != NULL) {
4383       // Invoke the JVM_OnLoad function
4384       JavaThread* thread = JavaThread::current();
4385       ThreadToNativeFromVM ttn(thread);
4386       HandleMark hm(thread);
4387       jint err = (*on_load_entry)(&main_vm, agent->options(), NULL);
4388       if (err != JNI_OK) {
4389         vm_exit_during_initialization("-Xrun library failed to init", agent->name());
4390       }
4391     } else {
4392       vm_exit_during_initialization("Could not find JVM_OnLoad function in -Xrun library", agent->name());
4393     }
4394   }
4395 }
4396 


4397 















4398 // Last thread running calls java.lang.Shutdown.shutdown()
4399 void JavaThread::invoke_shutdown_hooks() {
4400   HandleMark hm(this);
4401 
4402   // We could get here with a pending exception, if so clear it now.
4403   if (this->has_pending_exception()) {
4404     this->clear_pending_exception();
4405   }
4406 
4407   EXCEPTION_MARK;
4408   Klass* shutdown_klass =
4409     SystemDictionary::resolve_or_null(vmSymbols::java_lang_Shutdown(),
4410                                       THREAD);
4411   if (shutdown_klass != NULL) {
4412     // SystemDictionary::resolve_or_null will return null if there was
4413     // an exception.  If we cannot load the Shutdown class, just don't
4414     // call Shutdown.shutdown() at all.  This will mean the shutdown hooks
4415     // and finalizers (if runFinalizersOnExit is set) won't be run.
4416     // Note that if a shutdown hook was registered or runFinalizersOnExit
4417     // was called, the Shutdown class would have already been loaded


4502     VMThread::wait_for_vm_thread_exit();
4503     assert(SafepointSynchronize::is_at_safepoint(), "VM thread should exit at Safepoint");
4504     VMThread::destroy();
4505   }
4506 
4507   // clean up ideal graph printers
4508 #if defined(COMPILER2) && !defined(PRODUCT)
4509   IdealGraphPrinter::clean_up();
4510 #endif
4511 
4512   // Now, all Java threads are gone except daemon threads. Daemon threads
4513   // running Java code or in VM are stopped by the Safepoint. However,
4514   // daemon threads executing native code are still running.  But they
4515   // will be stopped at native=>Java/VM barriers. Note that we can't
4516   // simply kill or suspend them, as it is inherently deadlock-prone.
4517 
4518   VM_Exit::set_vm_exited();
4519 
4520   notify_vm_shutdown();
4521 
4522   // We are after VM_Exit::set_vm_exited() so we can't call
4523   // thread->smr_delete() or we will block on the Threads_lock.
4524   // Deleting the shutdown thread here is safe because another
4525   // JavaThread cannot have an active ThreadsListHandle for
4526   // this JavaThread.
4527   delete thread;
4528 
4529 #if INCLUDE_JVMCI
4530   if (JVMCICounterSize > 0) {
4531     FREE_C_HEAP_ARRAY(jlong, JavaThread::_jvmci_old_thread_counters);
4532   }
4533 #endif
4534 
4535   // exit_globals() will delete tty
4536   exit_globals();
4537 
4538   LogConfiguration::finalize();
4539 
4540   return true;
4541 }
4542 
4543 
4544 jboolean Threads::is_supported_jni_version_including_1_1(jint version) {
4545   if (version == JNI_VERSION_1_1) return JNI_TRUE;
4546   return is_supported_jni_version(version);
4547 }
4548 
4549 
4550 jboolean Threads::is_supported_jni_version(jint version) {
4551   if (version == JNI_VERSION_1_2) return JNI_TRUE;
4552   if (version == JNI_VERSION_1_4) return JNI_TRUE;
4553   if (version == JNI_VERSION_1_6) return JNI_TRUE;
4554   if (version == JNI_VERSION_1_8) return JNI_TRUE;
4555   if (version == JNI_VERSION_9) return JNI_TRUE;
4556   if (version == JNI_VERSION_10) return JNI_TRUE;
4557   return JNI_FALSE;
4558 }
4559 
4560 // Hash table of pointers found by a scan. Used for collecting hazard
4561 // pointers (ThreadsList references). Also used for collecting JavaThreads
4562 // that are indirectly referenced by hazard ptrs. An instance of this
4563 // class only contains one type of pointer.
4564 //
4565 class ThreadScanHashtable : public CHeapObj<mtThread> {
4566  private:
4567   static bool ptr_equals(void * const& s1, void * const& s2) {
4568     return s1 == s2;
4569   }
4570 
4571   static unsigned int ptr_hash(void * const& s1) {
4572     return (unsigned int)(((uint32_t)(uintptr_t)s1) * 2654435761u);
4573   }
4574 
4575   int _table_size;
4576   // ResourceHashtable SIZE is specified at compile time so our
4577   // dynamic _table_size is unused for now; 1031 is the first prime
4578   // after 1024.
4579   typedef ResourceHashtable<void *, int, &ThreadScanHashtable::ptr_hash,
4580                             &ThreadScanHashtable::ptr_equals, 1031,
4581                             ResourceObj::C_HEAP, mtThread> PtrTable;
4582   PtrTable * _ptrs;
4583 
4584  public:
4585   // ResourceHashtable is passed to various functions and populated in
4586   // different places so we allocate it using C_HEAP to make it immune
4587   // from any ResourceMarks that happen to be in the code paths.
4588   ThreadScanHashtable(int table_size) : _table_size(table_size), _ptrs(new (ResourceObj::C_HEAP, mtThread) PtrTable()) {}
4589 
4590   ~ThreadScanHashtable() { delete _ptrs; }
4591 
4592   bool has_entry(void *pointer) {
4593     int *val_ptr = _ptrs->get(pointer);
4594     return val_ptr != NULL && *val_ptr == 1;
4595   }
4596 
4597   void add_entry(void *pointer) {
4598     _ptrs->put(pointer, 1);
4599   }
4600 };
4601 
4602 // Closure to gather JavaThreads indirectly referenced by hazard ptrs
4603 // (ThreadsList references) into a hash table. This closure handles part 2
4604 // of the dance - adding all the JavaThreads referenced by the hazard
4605 // pointer (ThreadsList reference) to the hash table.
4606 //
4607 class AddThreadHazardPointerThreadClosure : public ThreadClosure {
4608  private:
4609   ThreadScanHashtable *_table;
4610 
4611  public:
4612   AddThreadHazardPointerThreadClosure(ThreadScanHashtable *table) : _table(table) {}
4613 
4614   virtual void do_thread(Thread *thread) {
4615     if (!_table->has_entry((void*)thread)) {
4616       // The same JavaThread might be on more than one ThreadsList or
4617       // more than one thread might be using the same ThreadsList. In
4618       // either case, we only need a single entry for a JavaThread.
4619       _table->add_entry((void*)thread);
4620     }
4621   }
4622 };
4623 
4624 // Closure to gather JavaThreads indirectly referenced by hazard ptrs
4625 // (ThreadsList references) into a hash table. This closure handles part 1
4626 // of the dance - hazard ptr chain walking and dispatch to another
4627 // closure.
4628 //
4629 class ScanHazardPtrGatherProtectedThreadsClosure : public ThreadClosure {
4630  private:
4631   ThreadScanHashtable *_table;
4632  public:
4633   ScanHazardPtrGatherProtectedThreadsClosure(ThreadScanHashtable *table) : _table(table) {}
4634 
4635   virtual void do_thread(Thread *thread) {
4636     assert_locked_or_safepoint(Threads_lock);
4637 
4638     if (thread == NULL) return;
4639 
4640     // This code races with Threads::acquire_stable_list() which is
4641     // lock-free so we have to handle some special situations.
4642     //
4643     ThreadsList *current_list = NULL;
4644     while (true) {
4645       current_list = thread->get_threads_hazard_ptr();
4646       // No hazard ptr so nothing more to do.
4647       if (current_list == NULL) {
4648         assert(thread->get_nested_threads_hazard_ptr() == NULL,
4649                "cannot have a nested hazard ptr with a NULL regular hazard ptr");
4650         return;
4651       }
4652 
4653       // If the hazard ptr is verified as stable (since it is not tagged),
4654       // then it is safe to use.
4655       if (!Thread::is_hazard_ptr_tagged(current_list)) break;
4656 
4657       // The hazard ptr is tagged as not yet verified as being stable
4658       // so we are racing with acquire_stable_list(). This exchange
4659       // attempts to invalidate the hazard ptr. If we win the race,
4660       // then we can ignore this unstable hazard ptr and the other
4661       // thread will retry the attempt to publish a stable hazard ptr.
4662       // If we lose the race, then we retry our attempt to look at the
4663       // hazard ptr.
4664       if (thread->cmpxchg_threads_hazard_ptr(NULL, current_list) == current_list) return;
4665     }
4666 
4667     // The current JavaThread has a hazard ptr (ThreadsList reference)
4668     // which might be _smr_java_thread_list or it might be an older
4669     // ThreadsList that has been removed but not freed. In either case,
4670     // the hazard ptr is protecting all the JavaThreads on that
4671     // ThreadsList.
4672     AddThreadHazardPointerThreadClosure add_cl(_table);
4673     current_list->threads_do(&add_cl);
4674 
4675     // Any NestedThreadsLists are also protecting JavaThreads so
4676     // gather those also; the ThreadsLists may be different.
4677     for (NestedThreadsList* node = thread->get_nested_threads_hazard_ptr();
4678          node != NULL; node = node->next()) {
4679       node->t_list()->threads_do(&add_cl);
4680     }
4681   }
4682 };
4683 
4684 // Closure to print JavaThreads that have a hazard ptr (ThreadsList
4685 // reference) that contains an indirect reference to a specific JavaThread.
4686 //
4687 class ScanHazardPtrPrintMatchingThreadsClosure : public ThreadClosure {
4688  private:
4689   JavaThread *_thread;
4690  public:
4691   ScanHazardPtrPrintMatchingThreadsClosure(JavaThread *thread) : _thread(thread) {}
4692 
4693   virtual void do_thread(Thread *thread) {
4694     assert_locked_or_safepoint(Threads_lock);
4695 
4696     if (thread == NULL) return;
4697     ThreadsList *current_list = thread->get_threads_hazard_ptr();
4698     if (current_list == NULL) {
4699       assert(thread->get_nested_threads_hazard_ptr() == NULL,
4700              "cannot have a nested hazard ptr with a NULL regular hazard ptr");
4701       return;
4702     }
4703     // If the hazard ptr is unverified, then ignore it.
4704     if (Thread::is_hazard_ptr_tagged(current_list)) return;
4705 
4706     // The current JavaThread has a hazard ptr (ThreadsList reference)
4707     // which might be _smr_java_thread_list or it might be an older
4708     // ThreadsList that has been removed but not freed. In either case,
4709     // the hazard ptr is protecting all the JavaThreads on that
4710     // ThreadsList, but we only care about matching a specific JavaThread.
4711     DO_JAVA_THREADS(current_list, p) {
4712       if (p == _thread) {
4713         log_debug(thread, smr)("tid=" UINTX_FORMAT ": Threads::smr_delete: thread1=" INTPTR_FORMAT " has a hazard pointer for thread2=" INTPTR_FORMAT, os::current_thread_id(), p2i(thread), p2i(_thread));
4714         break;
4715       }
4716     }
4717 
4718     // Any NestedThreadsLists are also protecting JavaThreads so
4719     // check those also; the ThreadsLists may be different.
4720     for (NestedThreadsList* node = thread->get_nested_threads_hazard_ptr();
4721          node != NULL; node = node->next()) {
4722       DO_JAVA_THREADS(node->t_list(), p) {
4723         if (p == _thread) {
4724           log_debug(thread, smr)("tid=" UINTX_FORMAT ": Threads::smr_delete: thread1=" INTPTR_FORMAT " has a nested hazard pointer for thread2=" INTPTR_FORMAT, os::current_thread_id(), p2i(thread), p2i(_thread));
4725           return;
4726         }
4727       }
4728     }
4729   }
4730 };
4731 
4732 // Return true if the specified JavaThread is protected by a hazard
4733 // pointer (ThreadsList reference). Otherwise, returns false.
4734 //
4735 bool Threads::is_a_protected_JavaThread(JavaThread *thread) {
4736   assert_locked_or_safepoint(Threads_lock);
4737 
4738   // Hash table size should be first power of two higher than twice
4739   // the length of the Threads list.
4740   int hash_table_size = MIN2(_number_of_threads, 32) << 1;
4741   hash_table_size--;
4742   hash_table_size |= hash_table_size >> 1;
4743   hash_table_size |= hash_table_size >> 2;
4744   hash_table_size |= hash_table_size >> 4;
4745   hash_table_size |= hash_table_size >> 8;
4746   hash_table_size |= hash_table_size >> 16;
4747   hash_table_size++;
4748 
4749   // Gather a hash table of the JavaThreads indirectly referenced by
4750   // hazard ptrs.
4751   ThreadScanHashtable *scan_table = new ThreadScanHashtable(hash_table_size);
4752   ScanHazardPtrGatherProtectedThreadsClosure scan_cl(scan_table);
4753   Threads::threads_do(&scan_cl);
4754 
4755   bool thread_is_protected = false;
4756   if (scan_table->has_entry((void*)thread)) {
4757     thread_is_protected = true;
4758   }
4759   delete scan_table;
4760   return thread_is_protected;
4761 }
4762 
4763 // Safely delete a JavaThread when it is no longer in use by a
4764 // ThreadsListHandle.
4765 //
4766 void Threads::smr_delete(JavaThread *thread) {
4767   assert(!Threads_lock->owned_by_self(), "sanity");
4768 
4769   bool has_logged_once = false;
4770   elapsedTimer timer;
4771   if (EnableThreadSMRStatistics) {
4772     timer.start();
4773   }
4774 
4775   while (true) {
4776     {
4777       // No safepoint check because this JavaThread is not on the
4778       // Threads list.
4779       MutexLockerEx ml(Threads_lock, Mutex::_no_safepoint_check_flag);
4780       // Cannot use a MonitorLockerEx helper here because we have
4781       // to drop the Threads_lock first if we wait.
4782       Threads::smr_delete_lock()->lock_without_safepoint_check();
4783       // Set the smr_delete_notify flag after we grab smr_delete_lock
4784       // and before we scan hazard ptrs because we're doing
4785       // double-check locking in release_stable_list().
4786       Threads::set_smr_delete_notify();
4787 
4788       if (!is_a_protected_JavaThread(thread)) {
4789         // This is the common case.
4790         Threads::clear_smr_delete_notify();
4791         Threads::smr_delete_lock()->unlock();
4792         break;
4793       }
4794       if (!has_logged_once) {
4795         has_logged_once = true;
4796         log_debug(thread, smr)("tid=" UINTX_FORMAT ": Threads::smr_delete: thread=" INTPTR_FORMAT " is not deleted.", os::current_thread_id(), p2i(thread));
4797         if (log_is_enabled(Debug, os, thread)) {
4798           ScanHazardPtrPrintMatchingThreadsClosure scan_cl(thread);
4799           Threads::threads_do(&scan_cl);
4800         }
4801       }
4802     } // We have to drop the Threads_lock to wait or delete the thread
4803 
4804     if (EnableThreadSMRStatistics) {
4805       _smr_delete_lock_wait_cnt++;
4806       if (_smr_delete_lock_wait_cnt > _smr_delete_lock_wait_max) {
4807         _smr_delete_lock_wait_max = _smr_delete_lock_wait_cnt;
4808       }
4809     }
4810     // Wait for a release_stable_list() call before we check again. No
4811     // safepoint check, no timeout, and not as suspend equivalent flag
4812     // because this JavaThread is not on the Threads list.
4813     Threads::smr_delete_lock()->wait(Mutex::_no_safepoint_check_flag, 0,
4814                                      !Mutex::_as_suspend_equivalent_flag);
4815     if (EnableThreadSMRStatistics) {
4816       _smr_delete_lock_wait_cnt--;
4817     }
4818 
4819     Threads::clear_smr_delete_notify();
4820     Threads::smr_delete_lock()->unlock();
4821     // Retry the whole scenario.
4822   }
4823 
4824   delete thread;
4825   if (EnableThreadSMRStatistics) {
4826     timer.stop();
4827     jint millis = (jint)timer.milliseconds();
4828     Threads::inc_smr_deleted_thread_cnt();
4829     Threads::add_smr_deleted_thread_times(millis);
4830     Threads::update_smr_deleted_thread_time_max(millis);
4831   }
4832 
4833   log_debug(thread, smr)("tid=" UINTX_FORMAT ": Threads::smr_delete: thread=" INTPTR_FORMAT " is deleted.", os::current_thread_id(), p2i(thread));
4834 }
4835 
4836 bool Threads::smr_delete_notify() {
4837   // Use load_acquire() in order to see any updates to _smr_delete_notify
4838   // earlier than when smr_delete_lock is grabbed.
4839   return (OrderAccess::load_acquire(&_smr_delete_notify) != 0);
4840 }
4841 
4842 // set_smr_delete_notify() and clear_smr_delete_notify() are called
4843 // under the protection of the smr_delete_lock, but we also use an
4844 // Atomic operation to ensure the memory update is seen earlier than
4845 // when the smr_delete_lock is dropped.
4846 //
4847 void Threads::set_smr_delete_notify() {
4848   Atomic::inc(&_smr_delete_notify);
4849 }
4850 
4851 void Threads::clear_smr_delete_notify() {
4852   Atomic::dec(&_smr_delete_notify);
4853 }
4854 
4855 // Closure to gather hazard ptrs (ThreadsList references) into a hash table.
4856 //
4857 class ScanHazardPtrGatherThreadsListClosure : public ThreadClosure {
4858  private:
4859   ThreadScanHashtable *_table;
4860  public:
4861   ScanHazardPtrGatherThreadsListClosure(ThreadScanHashtable *table) : _table(table) {}
4862 
4863   virtual void do_thread(Thread* thread) {
4864     assert_locked_or_safepoint(Threads_lock);
4865 
4866     if (thread == NULL) return;
4867     ThreadsList *threads = thread->get_threads_hazard_ptr();
4868     if (threads == NULL) {
4869       assert(thread->get_nested_threads_hazard_ptr() == NULL,
4870              "cannot have a nested hazard ptr with a NULL regular hazard ptr");
4871       return;
4872     }
4873     // In this closure we always ignore the tag that might mark this
4874     // hazard ptr as not yet verified. If we happen to catch an
4875     // unverified hazard ptr that is subsequently discarded (not
4876     // published), then the only side effect is that we might keep a
4877     // to-be-deleted ThreadsList alive a little longer.
4878     threads = Thread::untag_hazard_ptr(threads);
4879     if (!_table->has_entry((void*)threads)) {
4880       _table->add_entry((void*)threads);
4881     }
4882 
4883     // Any NestedThreadsLists are also protecting JavaThreads so
4884     // gather those also; the ThreadsLists may be different.
4885     for (NestedThreadsList* node = thread->get_nested_threads_hazard_ptr();
4886          node != NULL; node = node->next()) {
4887       threads = node->t_list();
4888       if (!_table->has_entry((void*)threads)) {
4889         _table->add_entry((void*)threads);
4890       }
4891     }
4892   }
4893 };
4894 
4895 // Safely free a ThreadsList after a Threads::add() or Threads::remove().
4896 // The specified ThreadsList may not get deleted during this call if it
4897 // is still in-use (referenced by a hazard ptr). Other ThreadsLists
4898 // in the chain may get deleted by this call if they are no longer in-use.
4899 void Threads::smr_free_list(ThreadsList* threads) {
4900   assert_locked_or_safepoint(Threads_lock);
4901 
4902   threads->set_next_list(_smr_to_delete_list);
4903   _smr_to_delete_list = threads;
4904   if (EnableThreadSMRStatistics) {
4905     _smr_to_delete_list_cnt++;
4906     if (_smr_to_delete_list_cnt > _smr_to_delete_list_max) {
4907       _smr_to_delete_list_max = _smr_to_delete_list_cnt;
4908     }
4909   }
4910 
4911   // Hash table size should be first power of two higher than twice the length of the ThreadsList
4912   int hash_table_size = MIN2(_number_of_threads, 32) << 1;
4913   hash_table_size--;
4914   hash_table_size |= hash_table_size >> 1;
4915   hash_table_size |= hash_table_size >> 2;
4916   hash_table_size |= hash_table_size >> 4;
4917   hash_table_size |= hash_table_size >> 8;
4918   hash_table_size |= hash_table_size >> 16;
4919   hash_table_size++;
4920 
4921   // Gather a hash table of the current hazard ptrs:
4922   ThreadScanHashtable *scan_table = new ThreadScanHashtable(hash_table_size);
4923   ScanHazardPtrGatherThreadsListClosure scan_cl(scan_table);
4924   Threads::threads_do(&scan_cl);
4925 
4926   // Walk through the linked list of pending freeable ThreadsLists
4927   // and free the ones that are not referenced from hazard ptrs.
4928   ThreadsList* current = _smr_to_delete_list;
4929   ThreadsList* prev = NULL;
4930   ThreadsList* next = NULL;
4931   bool threads_is_freed = false;
4932   while (current != NULL) {
4933     next = current->next_list();
4934     if (!scan_table->has_entry((void*)current)) {
4935       // This ThreadsList is not referenced by a hazard ptr.
4936       if (prev != NULL) {
4937         prev->set_next_list(next);
4938       }
4939       if (_smr_to_delete_list == current) {
4940         _smr_to_delete_list = next;
4941       }
4942 
4943       log_debug(thread, smr)("tid=" UINTX_FORMAT ": Threads::smr_free_list: threads=" INTPTR_FORMAT " is freed.", os::current_thread_id(), p2i(current));
4944       if (current == threads) threads_is_freed = true;
4945       delete current;
4946       if (EnableThreadSMRStatistics) {
4947         _smr_java_thread_list_free_cnt++;
4948         _smr_to_delete_list_cnt--;
4949       }
4950     } else {
4951       prev = current;
4952     }
4953     current = next;
4954   }
4955 
4956   if (!threads_is_freed) {
4957     // Only report "is not freed" on the original call to
4958     // smr_free_list() for this ThreadsList.
4959     log_debug(thread, smr)("tid=" UINTX_FORMAT ": Threads::smr_free_list: threads=" INTPTR_FORMAT " is not freed.", os::current_thread_id(), p2i(threads));
4960   }
4961 
4962   delete scan_table;
4963 }
4964 
4965 // Remove a JavaThread from a ThreadsList. The returned ThreadsList is a
4966 // new copy of the specified ThreadsList with the specified JavaThread
4967 // removed.
4968 ThreadsList *ThreadsList::remove_thread(ThreadsList* list, JavaThread* java_thread) {
4969   assert(list->_length > 0, "sanity");
4970 
4971   uint i = 0;
4972   DO_JAVA_THREADS(list, current) {
4973     if (current == java_thread) {
4974       break;
4975     }
4976     i++;
4977   }
4978   assert(i < list->_length, "did not find JavaThread on the list");
4979   const uint index = i;
4980   const uint new_length = list->_length - 1;
4981   const uint head_length = index;
4982   const uint tail_length = (new_length >= index) ? (new_length - index) : 0;
4983   ThreadsList *const new_list = new ThreadsList(new_length);
4984 
4985   if (head_length > 0) {
4986     Copy::disjoint_words((HeapWord*)list->_threads, (HeapWord*)new_list->_threads, head_length);
4987   }
4988   if (tail_length > 0) {
4989     Copy::disjoint_words((HeapWord*)list->_threads + index + 1, (HeapWord*)new_list->_threads + index, tail_length);
4990   }
4991 
4992   return new_list;
4993 }
4994 
4995 // Add a JavaThread to a ThreadsList. The returned ThreadsList is a
4996 // new copy of the specified ThreadsList with the specified JavaThread
4997 // appended to the end.
4998 ThreadsList *ThreadsList::add_thread(ThreadsList *list, JavaThread *java_thread) {
4999   const uint index = list->_length;
5000   const uint new_length = index + 1;
5001   const uint head_length = index;
5002   ThreadsList *const new_list = new ThreadsList(new_length);
5003 
5004   if (head_length > 0) {
5005     Copy::disjoint_words((HeapWord*)list->_threads, (HeapWord*)new_list->_threads, head_length);
5006   }
5007   *(JavaThread**)(new_list->_threads + index) = java_thread;
5008 
5009   return new_list;
5010 }
5011 
5012 int ThreadsList::find_index_of_JavaThread(JavaThread *target) {
5013   if (target == NULL) {
5014     return -1;
5015   }
5016   for (uint i = 0; i < length(); i++) {
5017     if (target == thread_at(i)) {
5018       return (int)i;
5019     }
5020   }
5021   return -1;
5022 }
5023 
5024 JavaThread* ThreadsList::find_JavaThread_from_java_tid(jlong java_tid) const {
5025   DO_JAVA_THREADS(this, thread) {
5026     oop tobj = thread->threadObj();
5027     // Ignore the thread if it hasn't run yet, has exited
5028     // or is starting to exit.
5029     if (tobj != NULL && !thread->is_exiting() &&
5030         java_tid == java_lang_Thread::thread_id(tobj)) {
5031       // found a match
5032       return thread;
5033     }
5034   }
5035   return NULL;
5036 }
5037 
5038 bool ThreadsList::includes(const JavaThread * const p) const {
5039   if (p == NULL) {
5040     return false;
5041   }
5042   DO_JAVA_THREADS(this, q) {
5043     if (q == p) {
5044       return true;
5045     }
5046   }
5047   return false;
5048 }
5049 
5050 void Threads::add(JavaThread* p, bool force_daemon) {
5051   // The threads lock must be owned at this point
5052   assert_locked_or_safepoint(Threads_lock);
5053 
5054   // See the comment for this method in thread.hpp for its purpose and
5055   // why it is called here.
5056   p->initialize_queues();
5057   p->set_next(_thread_list);
5058   _thread_list = p;
5059 
5060   // Once a JavaThread is added to the Threads list, smr_delete() has
5061   // to be used to delete it. Otherwise we can just delete it directly.
5062   p->set_on_thread_list();
5063 
5064   _number_of_threads++;
5065   oop threadObj = p->threadObj();
5066   bool daemon = true;
5067   // Bootstrapping problem: threadObj can be null for initial
5068   // JavaThread (or for threads attached via JNI)
5069   if ((!force_daemon) && (threadObj == NULL || !java_lang_Thread::is_daemon(threadObj))) {
5070     _number_of_non_daemon_threads++;
5071     daemon = false;
5072   }
5073 
5074   ThreadService::add_thread(p, daemon);
5075 
5076   // Maintain fast thread list
5077   ThreadsList *new_list = ThreadsList::add_thread(get_smr_java_thread_list(), p);
5078   if (EnableThreadSMRStatistics) {
5079     _smr_java_thread_list_alloc_cnt++;
5080     if (new_list->length() > _smr_java_thread_list_max) {
5081       _smr_java_thread_list_max = new_list->length();
5082     }
5083   }
5084   // Initial _smr_java_thread_list will not generate a "Threads::add" mesg.
5085   log_debug(thread, smr)("tid=" UINTX_FORMAT ": Threads::add: new ThreadsList=" INTPTR_FORMAT, os::current_thread_id(), p2i(new_list));
5086 
5087   ThreadsList *old_list = xchg_smr_java_thread_list(new_list);
5088   smr_free_list(old_list);
5089 
5090   // Possible GC point.
5091   Events::log(p, "Thread added: " INTPTR_FORMAT, p2i(p));
5092 }
5093 
5094 void Threads::remove(JavaThread* p) {
5095 
5096   // Reclaim the objectmonitors from the omInUseList and omFreeList of the moribund thread.
5097   ObjectSynchronizer::omFlush(p);
5098 
5099   // Extra scope needed for Thread_lock, so we can check
5100   // that we do not remove thread without safepoint code notice
5101   { MutexLocker ml(Threads_lock);
5102 
5103     assert(get_smr_java_thread_list()->includes(p), "p must be present");
5104 
5105     // Maintain fast thread list
5106     ThreadsList *new_list = ThreadsList::remove_thread(get_smr_java_thread_list(), p);
5107     if (EnableThreadSMRStatistics) {
5108       _smr_java_thread_list_alloc_cnt++;
5109       // This list is smaller so no need to check for a "longest" update.
5110     }
5111 
5112     // Final _smr_java_thread_list will not generate a "Threads::remove" mesg.
5113     log_debug(thread, smr)("tid=" UINTX_FORMAT ": Threads::remove: new ThreadsList=" INTPTR_FORMAT, os::current_thread_id(), p2i(new_list));
5114 
5115     ThreadsList *old_list = xchg_smr_java_thread_list(new_list);
5116     smr_free_list(old_list);
5117 
5118     JavaThread* current = _thread_list;
5119     JavaThread* prev    = NULL;
5120 
5121     while (current != p) {
5122       prev    = current;
5123       current = current->next();
5124     }
5125 
5126     if (prev) {
5127       prev->set_next(current->next());
5128     } else {
5129       _thread_list = p->next();
5130     }
5131 
5132     _number_of_threads--;
5133     oop threadObj = p->threadObj();
5134     bool daemon = true;
5135     if (threadObj == NULL || !java_lang_Thread::is_daemon(threadObj)) {
5136       _number_of_non_daemon_threads--;
5137       daemon = false;
5138 
5139       // Only one thread left, do a notify on the Threads_lock so a thread waiting
5140       // on destroy_vm will wake up.
5141       if (number_of_non_daemon_threads() == 1) {
5142         Threads_lock->notify_all();
5143       }
5144     }
5145     ThreadService::remove_thread(p, daemon);
5146 
5147     // Make sure that safepoint code disregard this thread. This is needed since
5148     // the thread might mess around with locks after this point. This can cause it
5149     // to do callbacks into the safepoint code. However, the safepoint code is not aware
5150     // of this thread since it is removed from the queue.
5151     p->set_terminated_value();
5152   } // unlock Threads_lock
5153 
5154   // Since Events::log uses a lock, we grab it outside the Threads_lock
5155   Events::log(p, "Thread exited: " INTPTR_FORMAT, p2i(p));
5156 }
5157 











5158 // Operations on the Threads list for GC.  These are not explicitly locked,
5159 // but the garbage collector must provide a safe context for them to run.
5160 // In particular, these things should never be called when the Threads_lock
5161 // is held by some other thread. (Note: the Safepoint abstraction also
5162 // uses the Threads_lock to guarantee this property. It also makes sure that
5163 // all threads gets blocked when exiting or starting).
5164 
5165 void Threads::oops_do(OopClosure* f, CodeBlobClosure* cf) {
5166   ALL_JAVA_THREADS(p) {
5167     p->oops_do(f, cf);
5168   }
5169   VMThread::vm_thread()->oops_do(f, cf);
5170 }
5171 
5172 void Threads::change_thread_claim_parity() {
5173   // Set the new claim parity.
5174   assert(_thread_claim_parity >= 0 && _thread_claim_parity <= 2,
5175          "Not in range.");
5176   _thread_claim_parity++;
5177   if (_thread_claim_parity == 3) _thread_claim_parity = 1;


5250   ThreadHandlesClosure(void f(Metadata*)) : _f(f) {}
5251   virtual void do_thread(Thread* thread) {
5252     thread->metadata_handles_do(_f);
5253   }
5254 };
5255 
5256 void Threads::metadata_handles_do(void f(Metadata*)) {
5257   // Only walk the Handles in Thread.
5258   ThreadHandlesClosure handles_closure(f);
5259   threads_do(&handles_closure);
5260 }
5261 
5262 void Threads::deoptimized_wrt_marked_nmethods() {
5263   ALL_JAVA_THREADS(p) {
5264     p->deoptimized_wrt_marked_nmethods();
5265   }
5266 }
5267 
5268 
5269 // Get count Java threads that are waiting to enter the specified monitor.
5270 GrowableArray<JavaThread*>* Threads::get_pending_threads(ThreadsList * t_list,
5271                                                          int count,
5272                                                          address monitor) {


5273   GrowableArray<JavaThread*>* result = new GrowableArray<JavaThread*>(count);
5274 
5275   int i = 0;
5276   DO_JAVA_THREADS(t_list, p) {


5277     if (!p->can_call_java()) continue;
5278 
5279     address pending = (address)p->current_pending_monitor();
5280     if (pending == monitor) {             // found a match
5281       if (i < count) result->append(p);   // save the first count matches
5282       i++;
5283     }
5284   }
5285 
5286   return result;
5287 }
5288 
5289 
5290 JavaThread *Threads::owning_thread_from_monitor_owner(ThreadsList * t_list,
5291                                                       address owner) {





5292   // NULL owner means not locked so we can skip the search
5293   if (owner == NULL) return NULL;
5294 
5295   DO_JAVA_THREADS(t_list, p) {


5296     // first, see if owner is the address of a Java thread
5297     if (owner == (address)p) return p;
5298   }
5299 
5300   // Cannot assert on lack of success here since this function may be
5301   // used by code that is trying to report useful problem information
5302   // like deadlock detection.
5303   if (UseHeavyMonitors) return NULL;
5304 
5305   // If we didn't find a matching Java thread and we didn't force use of
5306   // heavyweight monitors, then the owner is the stack address of the
5307   // Lock Word in the owning Java thread's stack.
5308   //
5309   JavaThread* the_owner = NULL;
5310   DO_JAVA_THREADS(t_list, q) {


5311     if (q->is_lock_owned(owner)) {
5312       the_owner = q;
5313       break;
5314     }
5315   }
5316 
5317   // cannot assert on lack of success here; see above comment
5318   return the_owner;
5319 }
5320 
5321 // Threads::print_on() is called at safepoint by VM_PrintThreads operation.
5322 void Threads::print_on(outputStream* st, bool print_stacks,
5323                        bool internal_format, bool print_concurrent_locks) {
5324   char buf[32];
5325   st->print_raw_cr(os::local_time_string(buf, sizeof(buf)));
5326 
5327   st->print_cr("Full thread dump %s (%s %s):",
5328                Abstract_VM_Version::vm_name(),
5329                Abstract_VM_Version::vm_release(),
5330                Abstract_VM_Version::vm_info_string());
5331   st->cr();
5332 
5333 #if INCLUDE_SERVICES
5334   // Dump concurrent locks
5335   ConcurrentLocksDump concurrent_locks;
5336   if (print_concurrent_locks) {
5337     concurrent_locks.dump_at_safepoint();
5338   }
5339 #endif // INCLUDE_SERVICES
5340 
5341   print_smr_info_on(st);
5342   st->cr();
5343 
5344   ALL_JAVA_THREADS(p) {
5345     ResourceMark rm;
5346     p->print_on(st);
5347     if (print_stacks) {
5348       if (internal_format) {
5349         p->trace_stack();
5350       } else {
5351         p->print_stack_on(st);
5352       }
5353     }
5354     st->cr();
5355 #if INCLUDE_SERVICES
5356     if (print_concurrent_locks) {
5357       concurrent_locks.print_locks_on(p, st);
5358     }
5359 #endif // INCLUDE_SERVICES
5360   }
5361 
5362   VMThread::vm_thread()->print_on(st);
5363   st->cr();
5364   Universe::heap()->print_gc_threads_on(st);
5365   WatcherThread* wt = WatcherThread::watcher_thread();
5366   if (wt != NULL) {
5367     wt->print_on(st);
5368     st->cr();
5369   }
5370 
5371   st->flush();
5372 }
5373 
5374 // Log Threads class SMR info.
5375 void Threads::log_smr_statistics() {
5376   LogTarget(Info, thread, smr) log;
5377   if (log.is_enabled()) {
5378     LogStream out(log);
5379     print_smr_info_on(&out);
5380   }
5381 }
5382 
5383 // Print Threads class SMR info.
5384 void Threads::print_smr_info_on(outputStream* st) {
5385   // Only grab the Threads_lock if we don't already own it
5386   // and if we are not reporting an error.
5387   MutexLockerEx ml((Threads_lock->owned_by_self() || VMError::is_error_reported()) ? NULL : Threads_lock);
5388 
5389   st->print_cr("Threads class SMR info:");
5390   st->print_cr("_smr_java_thread_list=" INTPTR_FORMAT ", length=%u, "
5391                "elements={", p2i(_smr_java_thread_list),
5392                _smr_java_thread_list->length());
5393   print_smr_info_elements_on(st, _smr_java_thread_list);
5394   st->print_cr("}");
5395   if (_smr_to_delete_list != NULL) {
5396     st->print_cr("_smr_to_delete_list=" INTPTR_FORMAT ", length=%u, "
5397                  "elements={", p2i(_smr_to_delete_list),
5398                  _smr_to_delete_list->length());
5399     print_smr_info_elements_on(st, _smr_to_delete_list);
5400     st->print_cr("}");
5401     for (ThreadsList *t_list = _smr_to_delete_list->next_list();
5402          t_list != NULL; t_list = t_list->next_list()) {
5403       st->print("next-> " INTPTR_FORMAT ", length=%u, "
5404                 "elements={", p2i(t_list), t_list->length());
5405       print_smr_info_elements_on(st, t_list);
5406       st->print_cr("}");
5407     }
5408   }
5409   if (!EnableThreadSMRStatistics) {
5410     return;
5411   }
5412   st->print_cr("_smr_java_thread_list_alloc_cnt=%ld, "
5413                "_smr_java_thread_list_free_cnt=%ld, "
5414                "_smr_java_thread_list_max=%u, "
5415                "_smr_nested_thread_list_max=%u",
5416                _smr_java_thread_list_alloc_cnt,
5417                _smr_java_thread_list_free_cnt,
5418                _smr_java_thread_list_max,
5419                _smr_nested_thread_list_max);
5420   if (_smr_tlh_cnt > 0) {
5421     st->print_cr("_smr_tlh_cnt=" INT32_FORMAT
5422                  ", _smr_tlh_times=" INT32_FORMAT
5423                  ", avg_smr_tlh_time=%0.2f"
5424                  ", _smr_tlh_time_max=" INT32_FORMAT,
5425                  _smr_tlh_cnt, _smr_tlh_times,
5426                  ((double) _smr_tlh_times / _smr_tlh_cnt),
5427                  _smr_tlh_time_max);
5428   }
5429   if (_smr_deleted_thread_cnt > 0) {
5430     st->print_cr("_smr_deleted_thread_cnt=" INT32_FORMAT
5431                  ", _smr_deleted_thread_times=" INT32_FORMAT
5432                  ", avg_smr_deleted_thread_time=%0.2f"
5433                  ", _smr_deleted_thread_time_max=" INT32_FORMAT,
5434                  _smr_deleted_thread_cnt, _smr_deleted_thread_times,
5435                  ((double) _smr_deleted_thread_times / _smr_deleted_thread_cnt),
5436                  _smr_deleted_thread_time_max);
5437   }
5438   st->print_cr("_smr_delete_lock_wait_cnt=%u, _smr_delete_lock_wait_max=%u",
5439                _smr_delete_lock_wait_cnt, _smr_delete_lock_wait_max);
5440   st->print_cr("_smr_to_delete_list_cnt=%u, _smr_to_delete_list_max=%u",
5441                _smr_to_delete_list_cnt, _smr_to_delete_list_max);
5442 }
5443 
5444 // Print ThreadsList elements (4 per line).
5445 void Threads::print_smr_info_elements_on(outputStream* st,
5446                                          ThreadsList* t_list) {
5447   uint cnt = 0;
5448   JavaThreadIterator jti(t_list);
5449   for (JavaThread *jt = jti.first(); jt != NULL; jt = jti.next()) {
5450     st->print(INTPTR_FORMAT, p2i(jt));
5451     if (cnt < t_list->length() - 1) {
5452       // Separate with comma or comma-space except for the last one.
5453       if (((cnt + 1) % 4) == 0) {
5454         // Four INTPTR_FORMAT fit on an 80 column line so end the
5455         // current line with just a comma.
5456         st->print_cr(",");
5457       } else {
5458         // Not the last one on the current line so use comma-space:
5459         st->print(", ");
5460       }
5461     } else {
5462       // Last one so just end the current line.
5463       st->cr();
5464     }
5465     cnt++;
5466   }
5467 }
5468 
5469 void Threads::print_on_error(Thread* this_thread, outputStream* st, Thread* current, char* buf,
5470                              int buflen, bool* found_current) {
5471   if (this_thread != NULL) {
5472     bool is_current = (current == this_thread);
5473     *found_current = *found_current || is_current;
5474     st->print("%s", is_current ? "=>" : "  ");
5475 
5476     st->print(PTR_FORMAT, p2i(this_thread));
5477     st->print(" ");
5478     this_thread->print_on_error(st, buf, buflen);
5479     st->cr();
5480   }
5481 }
5482 
5483 class PrintOnErrorClosure : public ThreadClosure {
5484   outputStream* _st;
5485   Thread* _current;
5486   char* _buf;
5487   int _buflen;
5488   bool* _found_current;
5489  public:
5490   PrintOnErrorClosure(outputStream* st, Thread* current, char* buf,
5491                       int buflen, bool* found_current) :
5492    _st(st), _current(current), _buf(buf), _buflen(buflen), _found_current(found_current) {}
5493 
5494   virtual void do_thread(Thread* thread) {
5495     Threads::print_on_error(thread, _st, _current, _buf, _buflen, _found_current);
5496   }
5497 };
5498 
5499 // Threads::print_on_error() is called by fatal error handler. It's possible
5500 // that VM is not at safepoint and/or current thread is inside signal handler.
5501 // Don't print stack trace, as the stack may not be walkable. Don't allocate
5502 // memory (even in resource area), it might deadlock the error handler.
5503 void Threads::print_on_error(outputStream* st, Thread* current, char* buf,
5504                              int buflen) {
5505   print_smr_info_on(st);
5506   st->cr();
5507 
5508   bool found_current = false;
5509   st->print_cr("Java Threads: ( => current thread )");
5510   ALL_JAVA_THREADS(thread) {
5511     print_on_error(thread, st, current, buf, buflen, &found_current);
5512   }
5513   st->cr();
5514 
5515   st->print_cr("Other Threads:");
5516   print_on_error(VMThread::vm_thread(), st, current, buf, buflen, &found_current);
5517   print_on_error(WatcherThread::watcher_thread(), st, current, buf, buflen, &found_current);
5518 
5519   PrintOnErrorClosure print_closure(st, current, buf, buflen, &found_current);
5520   Universe::heap()->gc_threads_do(&print_closure);
5521 
5522   if (!found_current) {
5523     st->cr();
5524     st->print("=>" PTR_FORMAT " (exited) ", p2i(current));
5525     current->print_on_error(st, buf, buflen);
5526     st->cr();
5527   }
5528   st->cr();
5529 
5530   st->print_cr("Threads with active compile tasks:");
5531   print_threads_compiling(st, buf, buflen);
5532 }
5533 
5534 void Threads::print_threads_compiling(outputStream* st, char* buf, int buflen) {
5535   ALL_JAVA_THREADS(thread) {
5536     if (thread->is_Compiler_thread()) {
5537       CompilerThread* ct = (CompilerThread*) thread;
5538       if (ct->task() != NULL) {
5539         thread->print_name_on_error(st, buf, buflen);
5540         ct->task()->print(st, NULL, true, true);
5541       }
5542     }
5543   }
5544 }
5545 
5546 
5547 // Internal SpinLock and Mutex
5548 // Based on ParkEvent
5549 


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