8212879: Make JVMTI TagMap table concurrent

Co-authored-by: Kim Barrett <kbarrett@openjdk.org>
Co-authored-by: Coleen Phillimore <coleenp@openjdk.org>
Reviewed-by: stefank, ihse, zgu, eosterlund, sspitsyn, kbarrett

Author: coleenp

make/hotspot/lib/JvmFeatures.gmk

@@ -84,7 +84,7 @@ ifneq ($(call check-jvm-feature, jvmti), true)
       jvmtiImpl.cpp jvmtiManageCapabilities.cpp jvmtiRawMonitor.cpp jvmtiUtil.cpp jvmtiTrace.cpp \
       jvmtiCodeBlobEvents.cpp jvmtiEnv.cpp jvmtiRedefineClasses.cpp jvmtiEnvBase.cpp jvmtiEnvThreadState.cpp \
       jvmtiTagMap.cpp jvmtiEventController.cpp evmCompat.cpp jvmtiEnter.xsl jvmtiExport.cpp \
-      jvmtiClassFileReconstituter.cpp
+      jvmtiClassFileReconstituter.cpp jvmtiTagMapTable.cpp
 endif
 
 ifneq ($(call check-jvm-feature, jvmci), true)

src/hotspot/share/classfile/dictionary.cpp

@@ -96,23 +96,6 @@ void Dictionary::free_entry(DictionaryEntry* entry) {
 }
 
 const int _resize_load_trigger = 5;       // load factor that will trigger the resize
-const double _resize_factor    = 2.0;     // by how much we will resize using current number of entries
-const int _resize_max_size     = 40423;   // the max dictionary size allowed
-const int _primelist[] = {107, 1009, 2017, 4049, 5051, 10103, 20201, _resize_max_size};
-const int _prime_array_size = sizeof(_primelist)/sizeof(int);
-
-// Calculate next "good" dictionary size based on requested count
-static int calculate_dictionary_size(int requested) {
-  int newsize = _primelist[0];
-  int index = 0;
-  for (newsize = _primelist[index]; index < (_prime_array_size - 1);
-       newsize = _primelist[++index]) {
-    if (requested <= newsize) {
-      break;
-    }
-  }
-  return newsize;
-}
 
 bool Dictionary::does_any_dictionary_needs_resizing() {
   return Dictionary::_some_dictionary_needs_resizing;
@@ -128,15 +111,14 @@ void Dictionary::check_if_needs_resize() {
 }
 
 bool Dictionary::resize_if_needed() {
+  assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint");
   int desired_size = 0;
   if (_needs_resizing == true) {
-    desired_size = calculate_dictionary_size((int)(_resize_factor*number_of_entries()));
-    if (desired_size >= _resize_max_size) {
-      desired_size = _resize_max_size;
-      // We have reached the limit, turn resizing off
-      _resizable = false;
-    }
-    if ((desired_size != 0) && (desired_size != table_size())) {
+    desired_size = calculate_resize(false);
+    assert(desired_size != 0, "bug in calculate_resize");
+    if (desired_size == table_size()) {
+      _resizable = false; // hit max
+    } else {
       if (!resize(desired_size)) {
         // Something went wrong, turn resizing off
         _resizable = false;

src/hotspot/share/gc/shared/oopStorageSet.hpp

@@ -38,7 +38,7 @@ class OopStorageSet : public AllStatic {
 public:
   // Must be updated when new OopStorages are introduced
   static const uint strong_count = 4 JVMTI_ONLY(+ 1);
-  static const uint weak_count = 5 JFR_ONLY(+ 1);
+  static const uint weak_count = 5 JVMTI_ONLY(+ 1) JFR_ONLY(+ 1);
   static const uint all_count = strong_count + weak_count;
 
 private:

src/hotspot/share/gc/shared/weakProcessor.cpp

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2017, 2019, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2017, 2020, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -37,16 +37,30 @@
 #include "runtime/globals.hpp"
 #include "utilities/macros.hpp"
 
-void WeakProcessor::do_serial_parts(BoolObjectClosure* is_alive,
-                                    OopClosure* keep_alive) {
-  WeakProcessorPhases::Iterator it = WeakProcessorPhases::serial_iterator();
-  for ( ; !it.is_end(); ++it) {
-    WeakProcessorPhases::processor(*it)(is_alive, keep_alive);
-  }
+#if INCLUDE_JVMTI
+#include "prims/jvmtiTagMap.hpp"
+#endif // INCLUDE_JVMTI
+
+void notify_jvmti_tagmaps() {
+#if INCLUDE_JVMTI
+  // Notify JVMTI tagmaps that a STW weak reference processing might be
+  // clearing entries, so the tagmaps need cleaning.  Doing this here allows
+  // the tagmap's oopstorage notification handler to not care whether it's
+  // invoked by STW or concurrent reference processing.
+  JvmtiTagMap::set_needs_cleaning();
+
+  // Notify JVMTI tagmaps that a STW collection may have moved objects, so
+  // the tagmaps need rehashing.  This isn't the right place for this, but
+  // is convenient because all the STW collectors use WeakProcessor.  One
+  // problem is that the end of a G1 concurrent collection also comes here,
+  // possibly triggering unnecessary rehashes.
+  JvmtiTagMap::set_needs_rehashing();
+#endif // INCLUDE_JVMTI
 }
 
 void WeakProcessor::weak_oops_do(BoolObjectClosure* is_alive, OopClosure* keep_alive) {
-  do_serial_parts(is_alive, keep_alive);
+
+  notify_jvmti_tagmaps();
 
   OopStorageSet::Iterator it = OopStorageSet::weak_iterator();
   for ( ; !it.is_end(); ++it) {
@@ -61,8 +75,6 @@ void WeakProcessor::weak_oops_do(BoolObjectClosure* is_alive, OopClosure* keep_a
 }
 
 void WeakProcessor::oops_do(OopClosure* closure) {
-  AlwaysTrueClosure always_true;
-  do_serial_parts(&always_true, closure);
 
   OopStorageSet::Iterator it = OopStorageSet::weak_iterator();
   for ( ; !it.is_end(); ++it) {
@@ -106,12 +118,12 @@ void WeakProcessor::Task::initialize() {
   if (_phase_times) {
     _phase_times->set_active_workers(_nworkers);
   }
+  notify_jvmti_tagmaps();
 }
 
 WeakProcessor::Task::Task(uint nworkers) :
   _phase_times(NULL),
   _nworkers(nworkers),
-  _serial_phases_done(WeakProcessorPhases::serial_phase_count),
   _storage_states()
 {
   initialize();
@@ -120,7 +132,6 @@ WeakProcessor::Task::Task(uint nworkers) :
 WeakProcessor::Task::Task(WeakProcessorPhaseTimes* phase_times, uint nworkers) :
   _phase_times(phase_times),
   _nworkers(nworkers),
-  _serial_phases_done(WeakProcessorPhases::serial_phase_count),
   _storage_states()
 {
   initialize();

src/hotspot/share/gc/shared/weakProcessor.hpp

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2017, 2019, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2017, 2020, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -72,16 +72,13 @@ class WeakProcessor : AllStatic {
 
 private:
   class GangTask;
-
-  static void do_serial_parts(BoolObjectClosure* is_alive, OopClosure* keep_alive);
 };
 
 class WeakProcessor::Task {
   typedef OopStorage::ParState<false, false> StorageState;
 
   WeakProcessorPhaseTimes* _phase_times;
   uint _nworkers;
-  SubTasksDone _serial_phases_done;
   OopStorageSetWeakParState<false, false> _storage_states;
 
   void initialize();

src/hotspot/share/gc/shared/weakProcessor.inline.hpp

@@ -96,33 +96,17 @@ void WeakProcessor::Task::work(uint worker_id,
 
   typedef WeakProcessorPhases::Iterator Iterator;
 
-  for (Iterator it = WeakProcessorPhases::serial_iterator(); !it.is_end(); ++it) {
-    WeakProcessorPhase phase = *it;
-    CountingIsAliveClosure<IsAlive> cl(is_alive);
-    uint serial_index = WeakProcessorPhases::serial_index(phase);
-    if (_serial_phases_done.try_claim_task(serial_index)) {
-      WeakProcessorPhaseTimeTracker pt(_phase_times, phase);
-      WeakProcessorPhases::processor(phase)(&cl, keep_alive);
-      if (_phase_times != NULL) {
-        _phase_times->record_phase_items(phase, cl.num_dead(), cl.num_total());
-      }
-    }
-  }
-
   for (Iterator it = WeakProcessorPhases::oopstorage_iterator(); !it.is_end(); ++it) {
     WeakProcessorPhase phase = *it;
     CountingSkippedIsAliveClosure<IsAlive, KeepAlive> cl(is_alive, keep_alive);
     WeakProcessorPhaseTimeTracker pt(_phase_times, phase, worker_id);
-    uint oopstorage_index = WeakProcessorPhases::oopstorage_index(phase);
-    StorageState* cur_state = _storage_states.par_state(oopstorage_index);
+    StorageState* cur_state = _storage_states.par_state(phase);
     cur_state->oops_do(&cl);
     cur_state->increment_num_dead(cl.num_skipped() + cl.num_dead());
     if (_phase_times != NULL) {
       _phase_times->record_worker_items(worker_id, phase, cl.num_dead(), cl.num_total());
     }
   }
-
-  _serial_phases_done.all_tasks_completed(_nworkers);
 }
 
 class WeakProcessor::GangTask : public AbstractGangTask {

src/hotspot/share/gc/shared/weakProcessorPhaseTimes.cpp

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2018, 2019, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2018, 2020, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -33,48 +33,12 @@
 #include "utilities/globalDefinitions.hpp"
 #include "utilities/ticks.hpp"
 
-static uint serial_phase_index(WeakProcessorPhase phase) {
-  return WeakProcessorPhases::serial_index(phase);
-}
-
-static bool is_serial_phase(WeakProcessorPhase phase) {
-  return WeakProcessorPhases::is_serial(phase);
-}
-
-static void assert_serial_phase(WeakProcessorPhase phase) {
-  assert(is_serial_phase(phase),
-         "Not a serial phase %u", static_cast<uint>(phase));
-}
-
-static void assert_oopstorage_phase(WeakProcessorPhase phase) {
-  assert(WeakProcessorPhases::is_oopstorage(phase),
-         "Not an oopstorage phase %u", static_cast<uint>(phase));
-}
-
 const double uninitialized_time = -1.0;
 
 #ifdef ASSERT
 static bool is_initialized_time(double t) { return t >= 0.0; }
-static bool is_initialized_items(size_t i) { return i != 0; }
 #endif // ASSERT
 
-static void reset_times(double* times, size_t ntimes) {
-  for (size_t i = 0; i < ntimes; ++i) {
-    times[i] = uninitialized_time;
-  }
-}
-
-static void reset_items(size_t* items, size_t nitems) {
-  for (size_t i = 0; i < nitems; ++i) {
-    items[i] = 0;
-  }
-}
-
-void WeakProcessorPhaseTimes::reset_phase_data() {
-  reset_times(_phase_times_sec, ARRAY_SIZE(_phase_times_sec));
-  reset_items(_phase_dead_items, ARRAY_SIZE(_phase_dead_items));
-  reset_items(_phase_total_items, ARRAY_SIZE(_phase_total_items));
-}
 
 WeakProcessorPhaseTimes::WeakProcessorPhaseTimes(uint max_threads) :
   _max_threads(max_threads),
@@ -84,8 +48,6 @@ WeakProcessorPhaseTimes::WeakProcessorPhaseTimes(uint max_threads) :
 {
   assert(_max_threads > 0, "max_threads must not be zero");
 
-  reset_phase_data();
-
   WorkerDataArray<double>** wpt = _worker_data;
   OopStorageSet::Iterator it = OopStorageSet::weak_iterator();
   for ( ; !it.is_end(); ++it) {
@@ -122,7 +84,6 @@ void WeakProcessorPhaseTimes::set_active_workers(uint n) {
 void WeakProcessorPhaseTimes::reset() {
   _active_workers = 0;
   _total_time_sec = uninitialized_time;
-  reset_phase_data();
   for (size_t i = 0; i < ARRAY_SIZE(_worker_data); ++i) {
     _worker_data[i]->reset();
   }
@@ -138,34 +99,8 @@ void WeakProcessorPhaseTimes::record_total_time_sec(double time_sec) {
   _total_time_sec = time_sec;
 }
 
-double WeakProcessorPhaseTimes::phase_time_sec(WeakProcessorPhase phase) const {
-  assert_serial_phase(phase);
-  assert(is_initialized_time(_phase_times_sec[serial_phase_index(phase)]),
-         "phase time not set %u", serial_phase_index(phase));
-  return _phase_times_sec[serial_phase_index(phase)];
-}
-
-void WeakProcessorPhaseTimes::record_phase_time_sec(WeakProcessorPhase phase, double time_sec) {
-  assert_serial_phase(phase);
-  assert(!is_initialized_time(_phase_times_sec[serial_phase_index(phase)]),
-         "Already set time for phase %u", serial_phase_index(phase));
-  _phase_times_sec[serial_phase_index(phase)] = time_sec;
-}
-
-void WeakProcessorPhaseTimes::record_phase_items(WeakProcessorPhase phase, size_t num_dead, size_t num_total) {
-  assert_serial_phase(phase);
-  uint p = serial_phase_index(phase);
-  assert(!is_initialized_items(_phase_dead_items[p]),
-         "Already set dead items for phase %u", p);
-  assert(!is_initialized_items(_phase_total_items[p]),
-         "Already set total items for phase %u", p);
-  _phase_dead_items[p] = num_dead;
-  _phase_total_items[p] = num_total;
-}
-
 WorkerDataArray<double>* WeakProcessorPhaseTimes::worker_data(WeakProcessorPhase phase) const {
-  assert_oopstorage_phase(phase);
-  return _worker_data[WeakProcessorPhases::oopstorage_index(phase)];
+  return _worker_data[phase];
 }
 
 double WeakProcessorPhaseTimes::worker_time_sec(uint worker_id, WeakProcessorPhase phase) const {
@@ -213,29 +148,15 @@ WeakProcessorPhaseTimeTracker::WeakProcessorPhaseTimeTracker(WeakProcessorPhaseT
   _worker_id(worker_id),
   _start_time(Ticks::now())
 {
-  assert_oopstorage_phase(_phase);
   assert(_times == NULL || worker_id < _times->active_workers(),
          "Invalid worker_id %u", worker_id);
 }
 
-WeakProcessorPhaseTimeTracker::WeakProcessorPhaseTimeTracker(WeakProcessorPhaseTimes* times,
-                                                             WeakProcessorPhase phase) :
-  _times(times),
-  _phase(phase),
-  _worker_id(0),
-  _start_time(Ticks::now())
-{
-  assert_serial_phase(phase);
-}
 
 WeakProcessorPhaseTimeTracker::~WeakProcessorPhaseTimeTracker() {
   if (_times != NULL) {
     double time_sec = elapsed_time_sec(_start_time, Ticks::now());
-    if (is_serial_phase(_phase)) {
-      _times->record_phase_time_sec(_phase, time_sec);
-    } else {
-      _times->record_worker_time_sec(_worker_id, _phase, time_sec);
-    }
+    _times->record_worker_time_sec(_worker_id, _phase, time_sec);
   }
 }
 
@@ -251,25 +172,6 @@ static const char* indent_str(size_t i) {
 
 #define TIME_FORMAT "%.1lfms"
 
-void WeakProcessorPhaseTimes::log_st_phase(WeakProcessorPhase phase,
-                                           uint indent) const {
-  assert_serial_phase(phase);
-  log_debug(gc, phases)("%s%s: " TIME_FORMAT,
-                        indent_str(indent),
-                        WeakProcessorPhases::description(phase),
-                        phase_time_sec(phase) * MILLIUNITS);
-
-  log_debug(gc, phases)("%s%s: " SIZE_FORMAT,
-                        indent_str(indent + 1),
-                        "Dead",
-                        _phase_dead_items[serial_phase_index(phase)]);
-
-  log_debug(gc, phases)("%s%s: " SIZE_FORMAT,
-                        indent_str(indent + 1),
-                        "Total",
-                        _phase_total_items[serial_phase_index(phase)]);
-}
-
 void WeakProcessorPhaseTimes::log_mt_phase_summary(WeakProcessorPhase phase,
                                                    uint indent) const {
   LogTarget(Debug, gc, phases) lt;
@@ -302,9 +204,6 @@ void WeakProcessorPhaseTimes::log_mt_phase_details(WorkerDataArray<T>* data,
 void WeakProcessorPhaseTimes::log_print_phases(uint indent) const {
   if (log_is_enabled(Debug, gc, phases)) {
     typedef WeakProcessorPhases::Iterator Iterator;
-    for (Iterator it = WeakProcessorPhases::serial_iterator(); !it.is_end(); ++it) {
-      log_st_phase(*it, indent);
-    }
     for (Iterator it = WeakProcessorPhases::oopstorage_iterator(); !it.is_end(); ++it) {
       log_mt_phase_summary(*it, indent);
     }