8028128: Add a type safe alternative for working with counter based data

Reviewed-by: dholmes, egahlin

hotspot/src/share/vm/classfile/classLoaderData.cpp

@@ -62,13 +62,13 @@
 #include "runtime/safepoint.hpp"
 #include "runtime/synchronizer.hpp"
 #include "utilities/growableArray.hpp"
+#include "utilities/macros.hpp"
 #include "utilities/ostream.hpp"
 
 #if INCLUDE_TRACE
  #include "trace/tracing.hpp"
 #endif
 
-
 ClassLoaderData * ClassLoaderData::_the_null_class_loader_data = NULL;
 
 ClassLoaderData::ClassLoaderData(Handle h_class_loader, bool is_anonymous, Dependencies dependencies) :
@@ -754,7 +754,7 @@ void ClassLoaderDataGraph::post_class_unload_events(void) {
   if (Tracing::enabled()) {
     if (Tracing::is_event_enabled(TraceClassUnloadEvent)) {
       assert(_unloading != NULL, "need class loader data unload list!");
-      _class_unload_time = Tracing::time();
+      _class_unload_time = Ticks::now();
       classes_unloading_do(&class_unload_event);
     }
     Tracing::on_unloading_classes();
@@ -832,7 +832,7 @@ void ClassLoaderData::print_value_on(outputStream* out) const {
 
 #if INCLUDE_TRACE
 
-TracingTime ClassLoaderDataGraph::_class_unload_time;
+Ticks ClassLoaderDataGraph::_class_unload_time;
 
 void ClassLoaderDataGraph::class_unload_event(Klass* const k) {
 

hotspot/src/share/vm/classfile/classLoaderData.hpp

@@ -33,7 +33,7 @@
 #include "utilities/growableArray.hpp"
 
 #if INCLUDE_TRACE
-# include "trace/traceTime.hpp"
+# include "utilities/ticks.hpp"
 #endif
 
 //
@@ -98,7 +98,7 @@ class ClassLoaderDataGraph : public AllStatic {
 
 #if INCLUDE_TRACE
  private:
-  static TracingTime _class_unload_time;
+  static Ticks _class_unload_time;
   static void class_unload_event(Klass* const k);
 #endif
 };

hotspot/src/share/vm/classfile/systemDictionary.cpp

@@ -55,13 +55,13 @@
 #include "runtime/signature.hpp"
 #include "services/classLoadingService.hpp"
 #include "services/threadService.hpp"
+#include "utilities/macros.hpp"
+#include "utilities/ticks.hpp"
 
 #if INCLUDE_TRACE
  #include "trace/tracing.hpp"
- #include "trace/traceMacros.hpp"
 #endif
 
-
 Dictionary*            SystemDictionary::_dictionary          = NULL;
 PlaceholderTable*      SystemDictionary::_placeholders        = NULL;
 Dictionary*            SystemDictionary::_shared_dictionary   = NULL;
@@ -598,7 +598,7 @@ Klass* SystemDictionary::resolve_instance_class_or_null(Symbol* name,
   assert(name != NULL && !FieldType::is_array(name) &&
          !FieldType::is_obj(name), "invalid class name");
 
-  TracingTime class_load_start_time = Tracing::time();
+  Ticks class_load_start_time = Ticks::now();
 
   // UseNewReflection
   // Fix for 4474172; see evaluation for more details
@@ -1006,7 +1006,7 @@ Klass* SystemDictionary::parse_stream(Symbol* class_name,
                                       TRAPS) {
   TempNewSymbol parsed_name = NULL;
 
-  TracingTime class_load_start_time = Tracing::time();
+  Ticks class_load_start_time = Ticks::now();
 
   ClassLoaderData* loader_data;
   if (host_klass.not_null()) {
@@ -2665,13 +2665,12 @@ void SystemDictionary::verify_obj_klass_present(Symbol* class_name,
 }
 
 // utility function for class load event
-void SystemDictionary::post_class_load_event(TracingTime start_time,
+void SystemDictionary::post_class_load_event(const Ticks& start_time,
                                              instanceKlassHandle k,
                                              Handle initiating_loader) {
 #if INCLUDE_TRACE
   EventClassLoad event(UNTIMED);
   if (event.should_commit()) {
-    event.set_endtime(Tracing::time());
     event.set_starttime(start_time);
     event.set_loadedClass(k());
     oop defining_class_loader = k->class_loader();

hotspot/src/share/vm/classfile/systemDictionary.hpp

@@ -31,7 +31,6 @@
 #include "oops/symbol.hpp"
 #include "runtime/java.hpp"
 #include "runtime/reflectionUtils.hpp"
-#include "trace/traceTime.hpp"
 #include "utilities/hashtable.hpp"
 #include "utilities/hashtable.inline.hpp"
 
@@ -78,6 +77,7 @@ class LoaderConstraintTable;
 template <MEMFLAGS F> class HashtableBucket;
 class ResolutionErrorTable;
 class SymbolPropertyTable;
+class Ticks;
 
 // Certain classes are preloaded, such as java.lang.Object and java.lang.String.
 // They are all "well-known", in the sense that no class loader is allowed
@@ -637,7 +637,7 @@ private:
   static void add_to_hierarchy(instanceKlassHandle k, TRAPS);
 
   // event based tracing
-  static void post_class_load_event(TracingTime start_time, instanceKlassHandle k,
+  static void post_class_load_event(const Ticks& start_time, instanceKlassHandle k,
                                     Handle initiating_loader);
   // We pass in the hashtable index so we can calculate it outside of
   // the SystemDictionary_lock.

hotspot/src/share/vm/gc_implementation/concurrentMarkSweep/concurrentMarkSweepGeneration.cpp

@@ -1993,7 +1993,7 @@ void CMSCollector::do_compaction_work(bool clear_all_soft_refs) {
   GenCollectedHeap* gch = GenCollectedHeap::heap();
 
   STWGCTimer* gc_timer = GenMarkSweep::gc_timer();
-  gc_timer->register_gc_start(os::elapsed_counter());
+  gc_timer->register_gc_start();
 
   SerialOldTracer* gc_tracer = GenMarkSweep::gc_tracer();
   gc_tracer->report_gc_start(gch->gc_cause(), gc_timer->gc_start());
@@ -2089,7 +2089,7 @@ void CMSCollector::do_compaction_work(bool clear_all_soft_refs) {
     size_policy()->msc_collection_end(gch->gc_cause());
   }
 
-  gc_timer->register_gc_end(os::elapsed_counter());
+  gc_timer->register_gc_end();
 
   gc_tracer->report_gc_end(gc_timer->gc_end(), gc_timer->time_partitions());
 
@@ -2475,7 +2475,7 @@ void CMSCollector::register_foreground_gc_start(GCCause::Cause cause) {
 
 void CMSCollector::register_gc_start(GCCause::Cause cause) {
   _cms_start_registered = true;
-  _gc_timer_cm->register_gc_start(os::elapsed_counter());
+  _gc_timer_cm->register_gc_start();
   _gc_tracer_cm->report_gc_start(cause, _gc_timer_cm->gc_start());
 }
 
@@ -2483,7 +2483,7 @@ void CMSCollector::register_gc_end() {
   if (_cms_start_registered) {
     report_heap_summary(GCWhen::AfterGC);
 
-    _gc_timer_cm->register_gc_end(os::elapsed_counter());
+    _gc_timer_cm->register_gc_end();
     _gc_tracer_cm->report_gc_end(_gc_timer_cm->gc_end(), _gc_timer_cm->time_partitions());
     _cms_start_registered = false;
   }

hotspot/src/share/vm/gc_implementation/concurrentMarkSweep/vmCMSOperations.cpp

@@ -145,7 +145,7 @@ void VM_CMS_Initial_Mark::doit() {
                                 );
 #endif /* USDT2 */
 
-  _collector->_gc_timer_cm->register_gc_pause_start("Initial Mark", os::elapsed_counter());
+  _collector->_gc_timer_cm->register_gc_pause_start("Initial Mark");
 
   GenCollectedHeap* gch = GenCollectedHeap::heap();
   GCCauseSetter gccs(gch, GCCause::_cms_initial_mark);
@@ -157,7 +157,7 @@ void VM_CMS_Initial_Mark::doit() {
 
   VM_CMS_Operation::verify_after_gc();
 
-  _collector->_gc_timer_cm->register_gc_pause_end(os::elapsed_counter());
+  _collector->_gc_timer_cm->register_gc_pause_end();
 
 #ifndef USDT2
   HS_DTRACE_PROBE(hs_private, cms__initmark__end);
@@ -182,7 +182,7 @@ void VM_CMS_Final_Remark::doit() {
                                 );
 #endif /* USDT2 */
 
-  _collector->_gc_timer_cm->register_gc_pause_start("Final Mark", os::elapsed_counter());
+  _collector->_gc_timer_cm->register_gc_pause_start("Final Mark");
 
   GenCollectedHeap* gch = GenCollectedHeap::heap();
   GCCauseSetter gccs(gch, GCCause::_cms_final_remark);
@@ -195,7 +195,7 @@ void VM_CMS_Final_Remark::doit() {
   VM_CMS_Operation::verify_after_gc();
 
   _collector->save_heap_summary();
-  _collector->_gc_timer_cm->register_gc_pause_end(os::elapsed_counter());
+  _collector->_gc_timer_cm->register_gc_pause_end();
 
 #ifndef USDT2
   HS_DTRACE_PROBE(hs_private, cms__remark__end);

hotspot/src/share/vm/gc_implementation/g1/g1CollectedHeap.cpp

@@ -56,6 +56,7 @@
 #include "oops/oop.inline.hpp"
 #include "oops/oop.pcgc.inline.hpp"
 #include "runtime/vmThread.hpp"
+#include "utilities/ticks.hpp"
 
 size_t G1CollectedHeap::_humongous_object_threshold_in_words = 0;
 
@@ -1284,7 +1285,7 @@ bool G1CollectedHeap::do_collection(bool explicit_gc,
   }
 
   STWGCTimer* gc_timer = G1MarkSweep::gc_timer();
-  gc_timer->register_gc_start(os::elapsed_counter());
+  gc_timer->register_gc_start();
 
   SerialOldTracer* gc_tracer = G1MarkSweep::gc_tracer();
   gc_tracer->report_gc_start(gc_cause(), gc_timer->gc_start());
@@ -1552,7 +1553,7 @@ bool G1CollectedHeap::do_collection(bool explicit_gc,
 
     post_full_gc_dump(gc_timer);
 
-    gc_timer->register_gc_end(os::elapsed_counter());
+    gc_timer->register_gc_end();
     gc_tracer->report_gc_end(gc_timer->gc_end(), gc_timer->time_partitions());
   }
 
@@ -2482,7 +2483,7 @@ void G1CollectedHeap::increment_old_marking_cycles_completed(bool concurrent) {
   FullGCCount_lock->notify_all();
 }
 
-void G1CollectedHeap::register_concurrent_cycle_start(jlong start_time) {
+void G1CollectedHeap::register_concurrent_cycle_start(const Ticks& start_time) {
   _concurrent_cycle_started = true;
   _gc_timer_cm->register_gc_start(start_time);
 
@@ -2496,7 +2497,7 @@ void G1CollectedHeap::register_concurrent_cycle_end() {
       _gc_tracer_cm->report_concurrent_mode_failure();
     }
 
-    _gc_timer_cm->register_gc_end(os::elapsed_counter());
+    _gc_timer_cm->register_gc_end();
     _gc_tracer_cm->report_gc_end(_gc_timer_cm->gc_end(), _gc_timer_cm->time_partitions());
 
     _concurrent_cycle_started = false;
@@ -3887,7 +3888,7 @@ G1CollectedHeap::do_collection_pause_at_safepoint(double target_pause_time_ms) {
     return false;
   }
 
-  _gc_timer_stw->register_gc_start(os::elapsed_counter());
+  _gc_timer_stw->register_gc_start();
 
   _gc_tracer_stw->report_gc_start(gc_cause(), _gc_timer_stw->gc_start());
 
@@ -4265,7 +4266,7 @@ G1CollectedHeap::do_collection_pause_at_safepoint(double target_pause_time_ms) {
 
     _gc_tracer_stw->report_evacuation_info(&evacuation_info);
     _gc_tracer_stw->report_tenuring_threshold(_g1_policy->tenuring_threshold());
-    _gc_timer_stw->register_gc_end(os::elapsed_counter());
+    _gc_timer_stw->register_gc_end();
     _gc_tracer_stw->report_gc_end(_gc_timer_stw->gc_end(), _gc_timer_stw->time_partitions());
   }
   // It should now be safe to tell the concurrent mark thread to start

hotspot/src/share/vm/gc_implementation/g1/g1CollectedHeap.hpp

@@ -72,6 +72,7 @@ class G1NewTracer;
 class G1OldTracer;
 class EvacuationFailedInfo;
 class nmethod;
+class Ticks;
 
 typedef OverflowTaskQueue<StarTask, mtGC>         RefToScanQueue;
 typedef GenericTaskQueueSet<RefToScanQueue, mtGC> RefToScanQueueSet;
@@ -746,7 +747,7 @@ public:
     return _old_marking_cycles_completed;
   }
 
-  void register_concurrent_cycle_start(jlong start_time);
+  void register_concurrent_cycle_start(const Ticks& start_time);
   void register_concurrent_cycle_end();
   void trace_heap_after_concurrent_cycle();
 

hotspot/src/share/vm/gc_implementation/parNew/parNewGeneration.cpp

@@ -915,7 +915,7 @@ void ParNewGeneration::collect(bool   full,
 
   GenCollectedHeap* gch = GenCollectedHeap::heap();
 
-  _gc_timer->register_gc_start(os::elapsed_counter());
+  _gc_timer->register_gc_start();
 
   assert(gch->kind() == CollectedHeap::GenCollectedHeap,
     "not a CMS generational heap");
@@ -1091,7 +1091,7 @@ void ParNewGeneration::collect(bool   full,
   gch->trace_heap_after_gc(&gc_tracer);
   gc_tracer.report_tenuring_threshold(tenuring_threshold());
 
-  _gc_timer->register_gc_end(os::elapsed_counter());
+  _gc_timer->register_gc_end();
 
   gc_tracer.report_gc_end(_gc_timer->gc_end(), _gc_timer->time_partitions());
 }

hotspot/src/share/vm/gc_implementation/parallelScavenge/psMarkSweep.cpp

@@ -114,7 +114,7 @@ bool PSMarkSweep::invoke_no_policy(bool clear_all_softrefs) {
   assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Sanity");
   GCCause::Cause gc_cause = heap->gc_cause();
 
-  _gc_timer->register_gc_start(os::elapsed_counter());
+  _gc_timer->register_gc_start();
   _gc_tracer->report_gc_start(gc_cause, _gc_timer->gc_start());
 
   PSAdaptiveSizePolicy* size_policy = heap->size_policy();
@@ -390,7 +390,7 @@ bool PSMarkSweep::invoke_no_policy(bool clear_all_softrefs) {
   ParallelTaskTerminator::print_termination_counts();
 #endif
 
-  _gc_timer->register_gc_end(os::elapsed_counter());
+  _gc_timer->register_gc_end();
 
   _gc_tracer->report_gc_end(_gc_timer->gc_end(), _gc_timer->time_partitions());
 

hotspot/src/share/vm/gc_implementation/parallelScavenge/psParallelCompact.cpp

@@ -2006,7 +2006,7 @@ bool PSParallelCompact::invoke_no_policy(bool maximum_heap_compaction) {
 
   ParallelScavengeHeap* heap = gc_heap();
 
-  _gc_timer.register_gc_start(os::elapsed_counter());
+  _gc_timer.register_gc_start();
   _gc_tracer.report_gc_start(heap->gc_cause(), _gc_timer.gc_start());
 
   TimeStamp marking_start;
@@ -2244,7 +2244,7 @@ bool PSParallelCompact::invoke_no_policy(bool maximum_heap_compaction) {
   ParallelTaskTerminator::print_termination_counts();
 #endif
 
-  _gc_timer.register_gc_end(os::elapsed_counter());
+  _gc_timer.register_gc_end();
 
   _gc_tracer.report_dense_prefix(dense_prefix(old_space_id));
   _gc_tracer.report_gc_end(_gc_timer.gc_end(), _gc_timer.time_partitions());

hotspot/src/share/vm/gc_implementation/parallelScavenge/psScavenge.cpp

@@ -263,7 +263,7 @@ bool PSScavenge::invoke_no_policy() {
   assert(_preserved_mark_stack.is_empty(), "should be empty");
   assert(_preserved_oop_stack.is_empty(), "should be empty");
 
-  _gc_timer.register_gc_start(os::elapsed_counter());
+  _gc_timer.register_gc_start();
 
   TimeStamp scavenge_entry;
   TimeStamp scavenge_midpoint;
@@ -691,7 +691,7 @@ bool PSScavenge::invoke_no_policy() {
 #endif
 
 
-  _gc_timer.register_gc_end(os::elapsed_counter());
+  _gc_timer.register_gc_end();
 
   _gc_tracer.report_gc_end(_gc_timer.gc_end(), _gc_timer.time_partitions());
 

hotspot/src/share/vm/gc_implementation/shared/gcTimer.cpp

@@ -25,52 +25,55 @@
 #include "precompiled.hpp"
 #include "gc_implementation/shared/gcTimer.hpp"
 #include "utilities/growableArray.hpp"
+#include "utilities/ticks.inline.hpp"
 
-void GCTimer::register_gc_start(jlong time) {
+// the "time" parameter for most functions
+// has a default value set by Ticks::now()
+
+void GCTimer::register_gc_start(const Ticks& time) {
   _time_partitions.clear();
   _gc_start = time;
 }
 
-void GCTimer::register_gc_end(jlong time) {
+void GCTimer::register_gc_end(const Ticks& time) {
   assert(!_time_partitions.has_active_phases(),
       "We should have ended all started phases, before ending the GC");
 
   _gc_end = time;
 }
 
-void GCTimer::register_gc_pause_start(const char* name, jlong time) {
+void GCTimer::register_gc_pause_start(const char* name, const Ticks& time) {
   _time_partitions.report_gc_phase_start(name, time);
 }
 
-void GCTimer::register_gc_pause_end(jlong time) {
+void GCTimer::register_gc_pause_end(const Ticks& time) {
   _time_partitions.report_gc_phase_end(time);
 }
 
-void GCTimer::register_gc_phase_start(const char* name, jlong time) {
+void GCTimer::register_gc_phase_start(const char* name, const Ticks& time) {
   _time_partitions.report_gc_phase_start(name, time);
 }
 
-void GCTimer::register_gc_phase_end(jlong time) {
+void GCTimer::register_gc_phase_end(const Ticks& time) {
   _time_partitions.report_gc_phase_end(time);
 }
 
-
+void STWGCTimer::register_gc_start(const Ticks& time) {
-void STWGCTimer::register_gc_start(jlong time) {
   GCTimer::register_gc_start(time);
   register_gc_pause_start("GC Pause", time);
 }
 
-void STWGCTimer::register_gc_end(jlong time) {
+void STWGCTimer::register_gc_end(const Ticks& time) {
   register_gc_pause_end(time);
   GCTimer::register_gc_end(time);
 }
 
-void ConcurrentGCTimer::register_gc_pause_start(const char* name, jlong time) {
+void ConcurrentGCTimer::register_gc_pause_start(const char* name) {
-  GCTimer::register_gc_pause_start(name, time);
+  GCTimer::register_gc_pause_start(name);
 }
 
-void ConcurrentGCTimer::register_gc_pause_end(jlong time) {
+void ConcurrentGCTimer::register_gc_pause_end() {
-  GCTimer::register_gc_pause_end(time);
+  GCTimer::register_gc_pause_end();
 }
 
 void PhasesStack::clear() {
@@ -111,11 +114,11 @@ TimePartitions::~TimePartitions() {
 void TimePartitions::clear() {
   _phases->clear();
   _active_phases.clear();
-  _sum_of_pauses = 0;
+  _sum_of_pauses = Tickspan();
-  _longest_pause = 0;
+  _longest_pause = Tickspan();
 }
 
-void TimePartitions::report_gc_phase_start(const char* name, jlong time) {
+void TimePartitions::report_gc_phase_start(const char* name, const Ticks& time) {
   assert(_phases->length() <= 1000, "Too many recored phases?");
 
   int level = _active_phases.count();
@@ -133,13 +136,13 @@ void TimePartitions::report_gc_phase_start(const char* name, jlong time) {
 void TimePartitions::update_statistics(GCPhase* phase) {
   // FIXME: This should only be done for pause phases
   if (phase->level() == 0) {
-    jlong pause = phase->end() - phase->start();
+    const Tickspan pause = phase->end() - phase->start();
     _sum_of_pauses += pause;
     _longest_pause = MAX2(pause, _longest_pause);
   }
 }
 
-void TimePartitions::report_gc_phase_end(jlong time) {
+void TimePartitions::report_gc_phase_end(const Ticks& time) {
   int phase_index = _active_phases.pop();
   GCPhase* phase = _phases->adr_at(phase_index);
   phase->set_end(time);
@@ -157,14 +160,6 @@ GCPhase* TimePartitions::phase_at(int index) const {
   return _phases->adr_at(index);
 }
 
-jlong TimePartitions::sum_of_pauses() {
-  return _sum_of_pauses;
-}
-
-jlong TimePartitions::longest_pause() {
-  return _longest_pause;
-}
-
 bool TimePartitions::has_active_phases() {
   return _active_phases.count() > 0;
 }
@@ -194,7 +189,7 @@ class TimePartitionPhasesIteratorTest {
     max_nested_pause_phases();
   }
 
-  static void validate_pause_phase(GCPhase* phase, int level, const char* name, jlong start, jlong end) {
+  static void validate_pause_phase(GCPhase* phase, int level, const char* name, const Ticks& start, const Ticks& end) {
     assert(phase->level() == level, "Incorrect level");
     assert(strcmp(phase->name(), name) == 0, "Incorrect name");
     assert(phase->start() == start, "Incorrect start");
@@ -209,8 +204,8 @@ class TimePartitionPhasesIteratorTest {
     TimePartitionPhasesIterator iter(&time_partitions);
 
     validate_pause_phase(iter.next(), 0, "PausePhase", 2, 8);
-    assert(time_partitions.sum_of_pauses() == 8-2, "Incorrect");
+    assert(time_partitions.sum_of_pauses() == Ticks(8) - Ticks(2), "Incorrect");
-    assert(time_partitions.longest_pause() == 8-2, "Incorrect");
+    assert(time_partitions.longest_pause() == Ticks(8) - Ticks(2), "Incorrect");
 
     assert(!iter.has_next(), "Too many elements");
   }
@@ -227,8 +222,8 @@ class TimePartitionPhasesIteratorTest {
     validate_pause_phase(iter.next(), 0, "PausePhase1", 2, 3);
     validate_pause_phase(iter.next(), 0, "PausePhase2", 4, 6);
 
-    assert(time_partitions.sum_of_pauses() == 3, "Incorrect");
+    assert(time_partitions.sum_of_pauses() == Ticks(3) - Ticks(0), "Incorrect");
-    assert(time_partitions.longest_pause() == 2, "Incorrect");
+    assert(time_partitions.longest_pause() == Ticks(2) - Ticks(0), "Incorrect");
 
     assert(!iter.has_next(), "Too many elements");
   }
@@ -245,8 +240,8 @@ class TimePartitionPhasesIteratorTest {
     validate_pause_phase(iter.next(), 0, "PausePhase", 2, 5);
     validate_pause_phase(iter.next(), 1, "SubPhase", 3, 4);
 
-    assert(time_partitions.sum_of_pauses() == 3, "Incorrect");
+    assert(time_partitions.sum_of_pauses() == Ticks(3) - Ticks(0), "Incorrect");
-    assert(time_partitions.longest_pause() == 3, "Incorrect");
+    assert(time_partitions.longest_pause() == Ticks(3) - Ticks(0), "Incorrect");
 
     assert(!iter.has_next(), "Too many elements");
   }
@@ -269,8 +264,8 @@ class TimePartitionPhasesIteratorTest {
     validate_pause_phase(iter.next(), 2, "SubPhase2", 4, 7);
     validate_pause_phase(iter.next(), 3, "SubPhase3", 5, 6);
 
-    assert(time_partitions.sum_of_pauses() == 7, "Incorrect");
+    assert(time_partitions.sum_of_pauses() == Ticks(7) - Ticks(0), "Incorrect");
-    assert(time_partitions.longest_pause() == 7, "Incorrect");
+    assert(time_partitions.longest_pause() == Ticks(7) - Ticks(0), "Incorrect");
 
     assert(!iter.has_next(), "Too many elements");
   }
@@ -298,8 +293,8 @@ class TimePartitionPhasesIteratorTest {
     validate_pause_phase(iter.next(), 1, "SubPhase3", 7, 8);
     validate_pause_phase(iter.next(), 1, "SubPhase4", 9, 10);
 
-    assert(time_partitions.sum_of_pauses() == 9, "Incorrect");
+    assert(time_partitions.sum_of_pauses() == Ticks(9) - Ticks(0), "Incorrect");
-    assert(time_partitions.longest_pause() == 9, "Incorrect");
+    assert(time_partitions.longest_pause() == Ticks(9) - Ticks(0), "Incorrect");
 
     assert(!iter.has_next(), "Too many elements");
   }
@@ -336,8 +331,8 @@ class TimePartitionPhasesIteratorTest {
     validate_pause_phase(iter.next(), 2, "SubPhase22", 12, 13);
     validate_pause_phase(iter.next(), 1, "SubPhase3", 15, 16);
 
-    assert(time_partitions.sum_of_pauses() == 15, "Incorrect");
+    assert(time_partitions.sum_of_pauses() == Ticks(15) - Ticks(0), "Incorrect");
-    assert(time_partitions.longest_pause() == 15, "Incorrect");
+    assert(time_partitions.longest_pause() == Ticks(15) - Ticks(0), "Incorrect");
 
     assert(!iter.has_next(), "Too many elements");
   }

hotspot/src/share/vm/gc_implementation/shared/gcTimer.hpp

@@ -28,6 +28,7 @@
 #include "memory/allocation.hpp"
 #include "prims/jni_md.h"
 #include "utilities/macros.hpp"
+#include "utilities/ticks.hpp"
 
 class ConcurrentPhase;
 class GCPhase;
@@ -45,21 +46,21 @@ class PhaseVisitor {
 class GCPhase {
   const char* _name;
   int _level;
-  jlong _start;
+  Ticks _start;
-  jlong _end;
+  Ticks _end;
 
  public:
   void set_name(const char* name) { _name = name; }
-  const char* name() { return _name; }
+  const char* name() const { return _name; }
 
-  int level() { return _level; }
+  int level() const { return _level; }
   void set_level(int level) { _level = level; }
 
-  jlong start() { return _start; }
+  const Ticks start() const { return _start; }
-  void set_start(jlong time) { _start = time; }
+  void set_start(const Ticks& time) { _start = time; }
 
-  jlong end() { return _end; }
+  const Ticks end() const { return _end; }
-  void set_end(jlong time) { _end = time; }
+  void set_end(const Ticks& time) { _end = time; }
 
   virtual void accept(PhaseVisitor* visitor) = 0;
 };
@@ -102,22 +103,22 @@ class TimePartitions {
   GrowableArray<PausePhase>* _phases;
   PhasesStack _active_phases;
 
-  jlong _sum_of_pauses;
+  Tickspan _sum_of_pauses;
-  jlong _longest_pause;
+  Tickspan _longest_pause;
 
  public:
   TimePartitions();
   ~TimePartitions();
   void clear();
 
-  void report_gc_phase_start(const char* name, jlong time);
+  void report_gc_phase_start(const char* name, const Ticks& time);
-  void report_gc_phase_end(jlong time);
+  void report_gc_phase_end(const Ticks& time);
 
   int num_phases() const;
   GCPhase* phase_at(int index) const;
 
-  jlong sum_of_pauses();
+  const Tickspan sum_of_pauses() const { return _sum_of_pauses; }
-  jlong longest_pause();
+  const Tickspan longest_pause() const { return _longest_pause; }
 
   bool has_active_phases();
  private:
@@ -133,40 +134,37 @@ class PhasesIterator {
 class GCTimer : public ResourceObj {
   NOT_PRODUCT(friend class GCTimerTest;)
  protected:
-  jlong _gc_start;
+  Ticks _gc_start;
-  jlong _gc_end;
+  Ticks _gc_end;
   TimePartitions _time_partitions;
 
  public:
-  virtual void register_gc_start(jlong time);
+  virtual void register_gc_start(const Ticks& time = Ticks::now());
-  virtual void register_gc_end(jlong time);
+  virtual void register_gc_end(const Ticks& time = Ticks::now());
 
-  void register_gc_phase_start(const char* name, jlong time);
+  void register_gc_phase_start(const char* name, const Ticks& time);
-  void register_gc_phase_end(jlong time);
+  void register_gc_phase_end(const Ticks& time);
 
-  jlong gc_start() { return _gc_start; }
+  const Ticks gc_start() const { return _gc_start; }
-  jlong gc_end() { return _gc_end; }
+  const Ticks gc_end() const { return _gc_end; }
 
   TimePartitions* time_partitions() { return &_time_partitions; }
 
-  long longest_pause();
-  long sum_of_pauses();
-
  protected:
-  void register_gc_pause_start(const char* name, jlong time);
+  void register_gc_pause_start(const char* name, const Ticks& time = Ticks::now());
-  void register_gc_pause_end(jlong time);
+  void register_gc_pause_end(const Ticks& time = Ticks::now());
 };
 
 class STWGCTimer : public GCTimer {
  public:
-  virtual void register_gc_start(jlong time);
+  virtual void register_gc_start(const Ticks& time = Ticks::now());
-  virtual void register_gc_end(jlong time);
+  virtual void register_gc_end(const Ticks& time = Ticks::now());
 };
 
 class ConcurrentGCTimer : public GCTimer {
  public:
-  void register_gc_pause_start(const char* name, jlong time);
+  void register_gc_pause_start(const char* name);
-  void register_gc_pause_end(jlong time);
+  void register_gc_pause_end();
 };
 
 class TimePartitionPhasesIterator {

hotspot/src/share/vm/gc_implementation/shared/gcTrace.cpp

@@ -32,6 +32,7 @@
 #include "memory/referenceProcessorStats.hpp"
 #include "runtime/os.hpp"
 #include "utilities/globalDefinitions.hpp"
+#include "utilities/ticks.inline.hpp"
 
 #if INCLUDE_ALL_GCS
 #include "gc_implementation/g1/evacuationInfo.hpp"
@@ -45,7 +46,7 @@ static GCId create_new_gc_id() {
   return GCTracer_next_gc_id++;
 }
 
-void GCTracer::report_gc_start_impl(GCCause::Cause cause, jlong timestamp) {
+void GCTracer::report_gc_start_impl(GCCause::Cause cause, const Ticks& timestamp) {
   assert_unset_gc_id();
 
   GCId gc_id = create_new_gc_id();
@@ -54,7 +55,7 @@ void GCTracer::report_gc_start_impl(GCCause::Cause cause, jlong timestamp) {
   _shared_gc_info.set_start_timestamp(timestamp);
 }
 
-void GCTracer::report_gc_start(GCCause::Cause cause, jlong timestamp) {
+void GCTracer::report_gc_start(GCCause::Cause cause, const Ticks& timestamp) {
   assert_unset_gc_id();
 
   report_gc_start_impl(cause, timestamp);
@@ -64,7 +65,7 @@ bool GCTracer::has_reported_gc_start() const {
   return _shared_gc_info.id() != SharedGCInfo::UNSET_GCID;
 }
 
-void GCTracer::report_gc_end_impl(jlong timestamp, TimePartitions* time_partitions) {
+void GCTracer::report_gc_end_impl(const Ticks& timestamp, TimePartitions* time_partitions) {
   assert_set_gc_id();
 
   _shared_gc_info.set_sum_of_pauses(time_partitions->sum_of_pauses());
@@ -75,7 +76,7 @@ void GCTracer::report_gc_end_impl(jlong timestamp, TimePartitions* time_partitio
   send_garbage_collection_event();
 }
 
-void GCTracer::report_gc_end(jlong timestamp, TimePartitions* time_partitions) {
+void GCTracer::report_gc_end(const Ticks& timestamp, TimePartitions* time_partitions) {
   assert_set_gc_id();
 
   report_gc_end_impl(timestamp, time_partitions);
@@ -97,10 +98,10 @@ class ObjectCountEventSenderClosure : public KlassInfoClosure {
   const GCId _gc_id;
   const double _size_threshold_percentage;
   const size_t _total_size_in_words;
-  const jlong _timestamp;
+  const Ticks _timestamp;
 
  public:
-  ObjectCountEventSenderClosure(GCId gc_id, size_t total_size_in_words, jlong timestamp) :
+  ObjectCountEventSenderClosure(GCId gc_id, size_t total_size_in_words, const Ticks& timestamp) :
     _gc_id(gc_id),
     _size_threshold_percentage(ObjectCountCutOffPercent / 100),
     _total_size_in_words(total_size_in_words),
@@ -131,9 +132,7 @@ void GCTracer::report_object_count_after_gc(BoolObjectClosure* is_alive_cl) {
     if (!cit.allocation_failed()) {
       HeapInspection hi(false, false, false, NULL);
       hi.populate_table(&cit, is_alive_cl);
-
+      ObjectCountEventSenderClosure event_sender(_shared_gc_info.id(), cit.size_of_instances_in_words(), Ticks::now());
-      jlong timestamp = os::elapsed_counter();
-      ObjectCountEventSenderClosure event_sender(_shared_gc_info.id(), cit.size_of_instances_in_words(), timestamp);
       cit.iterate(&event_sender);
     }
   }
@@ -147,7 +146,7 @@ void GCTracer::report_gc_heap_summary(GCWhen::Type when, const GCHeapSummary& he
   send_meta_space_summary_event(when, meta_space_summary);
 }
 
-void YoungGCTracer::report_gc_end_impl(jlong timestamp, TimePartitions* time_partitions) {
+void YoungGCTracer::report_gc_end_impl(const Ticks& timestamp, TimePartitions* time_partitions) {
   assert_set_gc_id();
   assert(_tenuring_threshold != UNSET_TENURING_THRESHOLD, "Tenuring threshold has not been reported");
 
@@ -167,14 +166,14 @@ void YoungGCTracer::report_tenuring_threshold(const uint tenuring_threshold) {
   _tenuring_threshold = tenuring_threshold;
 }
 
-void OldGCTracer::report_gc_end_impl(jlong timestamp, TimePartitions* time_partitions) {
+void OldGCTracer::report_gc_end_impl(const Ticks& timestamp, TimePartitions* time_partitions) {
   assert_set_gc_id();
 
   GCTracer::report_gc_end_impl(timestamp, time_partitions);
   send_old_gc_event();
 }
 
-void ParallelOldTracer::report_gc_end_impl(jlong timestamp, TimePartitions* time_partitions) {
+void ParallelOldTracer::report_gc_end_impl(const Ticks& timestamp, TimePartitions* time_partitions) {
   assert_set_gc_id();
 
   OldGCTracer::report_gc_end_impl(timestamp, time_partitions);
@@ -200,7 +199,7 @@ void G1NewTracer::report_yc_type(G1YCType type) {
   _g1_young_gc_info.set_type(type);
 }
 
-void G1NewTracer::report_gc_end_impl(jlong timestamp, TimePartitions* time_partitions) {
+void G1NewTracer::report_gc_end_impl(const Ticks& timestamp, TimePartitions* time_partitions) {
   assert_set_gc_id();
 
   YoungGCTracer::report_gc_end_impl(timestamp, time_partitions);

hotspot/src/share/vm/gc_implementation/shared/gcTrace.hpp

@@ -35,6 +35,7 @@
 #include "gc_implementation/g1/g1YCTypes.hpp"
 #endif
 #include "utilities/macros.hpp"
+#include "utilities/ticks.hpp"
 
 typedef uint GCId;
 
@@ -47,8 +48,6 @@ class TimePartitions;
 class BoolObjectClosure;
 
 class SharedGCInfo VALUE_OBJ_CLASS_SPEC {
-  static const jlong UNSET_TIMESTAMP = -1;
-
  public:
   static const GCId UNSET_GCID = (GCId)-1;
 
@@ -56,23 +55,30 @@ class SharedGCInfo VALUE_OBJ_CLASS_SPEC {
   GCId _id;
   GCName _name;
   GCCause::Cause _cause;
-  jlong _start_timestamp;
+  Ticks     _start_timestamp;
-  jlong _end_timestamp;
+  Ticks     _end_timestamp;
-  jlong _sum_of_pauses;
+  Tickspan  _sum_of_pauses;
-  jlong _longest_pause;
+  Tickspan  _longest_pause;
 
  public:
-  SharedGCInfo(GCName name) : _id(UNSET_GCID), _name(name), _cause(GCCause::_last_gc_cause),
+  SharedGCInfo(GCName name) :
-      _start_timestamp(UNSET_TIMESTAMP), _end_timestamp(UNSET_TIMESTAMP), _sum_of_pauses(0), _longest_pause(0) {}
+    _id(UNSET_GCID),
+    _name(name),
+    _cause(GCCause::_last_gc_cause),
+    _start_timestamp(),
+    _end_timestamp(),
+    _sum_of_pauses(),
+    _longest_pause() {
+  }
 
   void set_id(GCId id) { _id = id; }
   GCId id() const { return _id; }
 
-  void set_start_timestamp(jlong timestamp) { _start_timestamp = timestamp; }
+  void set_start_timestamp(const Ticks& timestamp) { _start_timestamp = timestamp; }
-  jlong start_timestamp() const { return _start_timestamp; }
+  const Ticks start_timestamp() const { return _start_timestamp; }
 
-  void set_end_timestamp(jlong timestamp) { _end_timestamp = timestamp; }
+  void set_end_timestamp(const Ticks& timestamp) { _end_timestamp = timestamp; }
-  jlong end_timestamp() const { return _end_timestamp; }
+  const Ticks end_timestamp() const { return _end_timestamp; }
 
   void set_name(GCName name) { _name = name; }
   GCName name() const { return _name; }
@@ -80,11 +86,11 @@ class SharedGCInfo VALUE_OBJ_CLASS_SPEC {
   void set_cause(GCCause::Cause cause) { _cause = cause; }
   GCCause::Cause cause() const { return _cause; }
 
-  void set_sum_of_pauses(jlong duration) { _sum_of_pauses = duration; }
+  void set_sum_of_pauses(const Tickspan& duration) { _sum_of_pauses = duration; }
-  jlong sum_of_pauses() const { return _sum_of_pauses; }
+  const Tickspan sum_of_pauses() const { return _sum_of_pauses; }
 
-  void set_longest_pause(jlong duration) { _longest_pause = duration; }
+  void set_longest_pause(const Tickspan& duration) { _longest_pause = duration; }
-  jlong longest_pause() const { return _longest_pause; }
+  const Tickspan longest_pause() const { return _longest_pause; }
 };
 
 class ParallelOldGCInfo VALUE_OBJ_CLASS_SPEC {
@@ -116,8 +122,8 @@ class GCTracer : public ResourceObj {
   SharedGCInfo _shared_gc_info;
 
  public:
-  void report_gc_start(GCCause::Cause cause, jlong timestamp);
+  void report_gc_start(GCCause::Cause cause, const Ticks& timestamp);
-  void report_gc_end(jlong timestamp, TimePartitions* time_partitions);
+  void report_gc_end(const Ticks& timestamp, TimePartitions* time_partitions);
   void report_gc_heap_summary(GCWhen::Type when, const GCHeapSummary& heap_summary, const MetaspaceSummary& meta_space_summary) const;
   void report_gc_reference_stats(const ReferenceProcessorStats& rp) const;
   void report_object_count_after_gc(BoolObjectClosure* object_filter) NOT_SERVICES_RETURN;
@@ -125,8 +131,8 @@ class GCTracer : public ResourceObj {
 
  protected:
   GCTracer(GCName name) : _shared_gc_info(name) {}
-  virtual void report_gc_start_impl(GCCause::Cause cause, jlong timestamp);
+  virtual void report_gc_start_impl(GCCause::Cause cause, const Ticks& timestamp);
-  virtual void report_gc_end_impl(jlong timestamp, TimePartitions* time_partitions);
+  virtual void report_gc_end_impl(const Ticks& timestamp, TimePartitions* time_partitions);
 
  private:
   void send_garbage_collection_event() const;
@@ -143,7 +149,7 @@ class YoungGCTracer : public GCTracer {
 
  protected:
   YoungGCTracer(GCName name) : GCTracer(name), _tenuring_threshold(UNSET_TENURING_THRESHOLD) {}
-  virtual void report_gc_end_impl(jlong timestamp, TimePartitions* time_partitions);
+  virtual void report_gc_end_impl(const Ticks& timestamp, TimePartitions* time_partitions);
 
  public:
   void report_promotion_failed(const PromotionFailedInfo& pf_info);
@@ -157,7 +163,7 @@ class YoungGCTracer : public GCTracer {
 class OldGCTracer : public GCTracer {
  protected:
   OldGCTracer(GCName name) : GCTracer(name) {}
-  virtual void report_gc_end_impl(jlong timestamp, TimePartitions* time_partitions);
+  virtual void report_gc_end_impl(const Ticks& timestamp, TimePartitions* time_partitions);
 
  public:
   void report_concurrent_mode_failure();
@@ -175,7 +181,7 @@ class ParallelOldTracer : public OldGCTracer {
   void report_dense_prefix(void* dense_prefix);
 
  protected:
-  void report_gc_end_impl(jlong timestamp, TimePartitions* time_partitions);
+  void report_gc_end_impl(const Ticks& timestamp, TimePartitions* time_partitions);
 
  private:
   void send_parallel_old_event() const;
@@ -209,7 +215,7 @@ class G1NewTracer : public YoungGCTracer {
   G1NewTracer() : YoungGCTracer(G1New) {}
 
   void report_yc_type(G1YCType type);
-  void report_gc_end_impl(jlong timestamp, TimePartitions* time_partitions);
+  void report_gc_end_impl(const Ticks& timestamp, TimePartitions* time_partitions);
   void report_evacuation_info(EvacuationInfo* info);
   void report_evacuation_failed(EvacuationFailedInfo& ef_info);
 

hotspot/src/share/vm/gc_implementation/shared/gcTraceSend.cpp

@@ -55,12 +55,11 @@ void GCTracer::send_garbage_collection_event() const {
 }
 
 void GCTracer::send_reference_stats_event(ReferenceType type, size_t count) const {
-  EventGCReferenceStatistics e(UNTIMED);
+  EventGCReferenceStatistics e;
   if (e.should_commit()) {
       e.set_gcId(_shared_gc_info.id());
       e.set_type((u1)type);
       e.set_count(count);
-      e.set_endtime(os::elapsed_counter());
       e.commit();
   }
 }
@@ -107,22 +106,20 @@ static TraceStructCopyFailed to_trace_struct(const CopyFailedInfo& cf_info) {
 }
 
 void YoungGCTracer::send_promotion_failed_event(const PromotionFailedInfo& pf_info) const {
-  EventPromotionFailed e(UNTIMED);
+  EventPromotionFailed e;
   if (e.should_commit()) {
     e.set_gcId(_shared_gc_info.id());
     e.set_data(to_trace_struct(pf_info));
     e.set_thread(pf_info.thread()->thread_id());
-    e.set_endtime(os::elapsed_counter());
     e.commit();
   }
 }
 
 // Common to CMS and G1
 void OldGCTracer::send_concurrent_mode_failure_event() {
-  EventConcurrentModeFailure e(UNTIMED);
+  EventConcurrentModeFailure e;
   if (e.should_commit()) {
     e.set_gcId(_shared_gc_info.id());
-    e.set_endtime(os::elapsed_counter());
     e.commit();
   }
 }
@@ -140,7 +137,7 @@ void G1NewTracer::send_g1_young_gc_event() {
 }
 
 void G1NewTracer::send_evacuation_info_event(EvacuationInfo* info) {
-  EventEvacuationInfo e(UNTIMED);
+  EventEvacuationInfo e;
   if (e.should_commit()) {
     e.set_gcId(_shared_gc_info.id());
     e.set_cSetRegions(info->collectionset_regions());
@@ -151,17 +148,15 @@ void G1NewTracer::send_evacuation_info_event(EvacuationInfo* info) {
     e.set_allocRegionsUsedAfter(info->alloc_regions_used_before() + info->bytes_copied());
     e.set_bytesCopied(info->bytes_copied());
     e.set_regionsFreed(info->regions_freed());
-    e.set_endtime(os::elapsed_counter());
     e.commit();
   }
 }
 
 void G1NewTracer::send_evacuation_failed_event(const EvacuationFailedInfo& ef_info) const {
-  EventEvacuationFailed e(UNTIMED);
+  EventEvacuationFailed e;
   if (e.should_commit()) {
     e.set_gcId(_shared_gc_info.id());
     e.set_data(to_trace_struct(ef_info));
-    e.set_endtime(os::elapsed_counter());
     e.commit();
   }
 }
@@ -195,13 +190,12 @@ class GCHeapSummaryEventSender : public GCHeapSummaryVisitor {
   void visit(const GCHeapSummary* heap_summary) const {
     const VirtualSpaceSummary& heap_space = heap_summary->heap();
 
-    EventGCHeapSummary e(UNTIMED);
+    EventGCHeapSummary e;
     if (e.should_commit()) {
       e.set_gcId(_id);
       e.set_when((u1)_when);
       e.set_heapSpace(to_trace_struct(heap_space));
       e.set_heapUsed(heap_summary->used());
-      e.set_endtime(os::elapsed_counter());
       e.commit();
     }
   }
@@ -216,7 +210,7 @@ class GCHeapSummaryEventSender : public GCHeapSummaryVisitor {
     const SpaceSummary& from_space = ps_heap_summary->from();
     const SpaceSummary& to_space = ps_heap_summary->to();
 
-    EventPSHeapSummary e(UNTIMED);
+    EventPSHeapSummary e;
     if (e.should_commit()) {
       e.set_gcId(_id);
       e.set_when((u1)_when);
@@ -227,7 +221,6 @@ class GCHeapSummaryEventSender : public GCHeapSummaryVisitor {
       e.set_edenSpace(to_trace_struct(ps_heap_summary->eden()));
       e.set_fromSpace(to_trace_struct(ps_heap_summary->from()));
       e.set_toSpace(to_trace_struct(ps_heap_summary->to()));
-      e.set_endtime(os::elapsed_counter());
       e.commit();
     }
   }
@@ -249,14 +242,13 @@ static TraceStructMetaspaceSizes to_trace_struct(const MetaspaceSizes& sizes) {
 }
 
 void GCTracer::send_meta_space_summary_event(GCWhen::Type when, const MetaspaceSummary& meta_space_summary) const {
-  EventMetaspaceSummary e(UNTIMED);
+  EventMetaspaceSummary e;
   if (e.should_commit()) {
     e.set_gcId(_shared_gc_info.id());
     e.set_when((u1) when);
     e.set_metaspace(to_trace_struct(meta_space_summary.meta_space()));
     e.set_dataSpace(to_trace_struct(meta_space_summary.data_space()));
     e.set_classSpace(to_trace_struct(meta_space_summary.class_space()));
-    e.set_endtime(os::elapsed_counter());
     e.commit();
   }
 }

hotspot/src/share/vm/gc_implementation/shared/gcTraceTime.cpp

@@ -31,12 +31,13 @@
 #include "runtime/thread.inline.hpp"
 #include "runtime/timer.hpp"
 #include "utilities/ostream.hpp"
+#include "utilities/ticks.inline.hpp"
 
 
 GCTraceTime::GCTraceTime(const char* title, bool doit, bool print_cr, GCTimer* timer) :
-    _title(title), _doit(doit), _print_cr(print_cr), _timer(timer) {
+    _title(title), _doit(doit), _print_cr(print_cr), _timer(timer), _start_counter() {
   if (_doit || _timer != NULL) {
-    _start_counter = os::elapsed_counter();
+    _start_counter.stamp();
   }
 
   if (_timer != NULL) {
@@ -57,10 +58,10 @@ GCTraceTime::GCTraceTime(const char* title, bool doit, bool print_cr, GCTimer* t
 }
 
 GCTraceTime::~GCTraceTime() {
-  jlong stop_counter = 0;
+  Ticks stop_counter;
 
   if (_doit || _timer != NULL) {
-    stop_counter = os::elapsed_counter();
+    stop_counter.stamp();
   }
 
   if (_timer != NULL) {
@@ -68,11 +69,12 @@ GCTraceTime::~GCTraceTime() {
   }
 
   if (_doit) {
-    double seconds = TimeHelper::counter_to_seconds(stop_counter - _start_counter);
+    const Tickspan duration = stop_counter - _start_counter;
+    double duration_in_seconds = TicksToTimeHelper::seconds(duration);
     if (_print_cr) {
-      gclog_or_tty->print_cr(", %3.7f secs]", seconds);
+      gclog_or_tty->print_cr(", %3.7f secs]", duration_in_seconds);
     } else {
-      gclog_or_tty->print(", %3.7f secs]", seconds);
+      gclog_or_tty->print(", %3.7f secs]", duration_in_seconds);
     }
     gclog_or_tty->flush();
   }

hotspot/src/share/vm/gc_implementation/shared/gcTraceTime.hpp

@@ -26,6 +26,7 @@
 #define SHARE_VM_GC_IMPLEMENTATION_SHARED_GCTRACETIME_HPP
 
 #include "prims/jni_md.h"
+#include "utilities/ticks.hpp"
 
 class GCTimer;
 
@@ -34,7 +35,7 @@ class GCTraceTime {
   bool _doit;
   bool _print_cr;
   GCTimer* _timer;
-  jlong _start_counter;
+  Ticks _start_counter;
 
  public:
   GCTraceTime(const char* title, bool doit, bool print_cr, GCTimer* timer);

hotspot/src/share/vm/gc_implementation/shared/objectCountEventSender.cpp

@@ -28,10 +28,11 @@
 #include "memory/heapInspection.hpp"
 #include "trace/tracing.hpp"
 #include "utilities/globalDefinitions.hpp"
+#include "utilities/ticks.hpp"
 
 #if INCLUDE_SERVICES
 
-void ObjectCountEventSender::send(const KlassInfoEntry* entry, GCId gc_id, jlong timestamp) {
+void ObjectCountEventSender::send(const KlassInfoEntry* entry, GCId gc_id, const Ticks& timestamp) {
 #if INCLUDE_TRACE
   assert(Tracing::is_event_enabled(EventObjectCountAfterGC::eventId),
          "Only call this method if the event is enabled");

hotspot/src/share/vm/gc_implementation/shared/objectCountEventSender.hpp

@@ -32,10 +32,11 @@
 #if INCLUDE_SERVICES
 
 class KlassInfoEntry;
+class Ticks;
 
 class ObjectCountEventSender : public AllStatic {
  public:
-  static void send(const KlassInfoEntry* entry, GCId gc_id, jlong timestamp);
+  static void send(const KlassInfoEntry* entry, GCId gc_id, const Ticks& timestamp);
   static bool should_send_event();
 };
 

hotspot/src/share/vm/memory/defNewGeneration.cpp

@@ -562,7 +562,7 @@ void DefNewGeneration::collect(bool   full,
 
   GenCollectedHeap* gch = GenCollectedHeap::heap();
 
-  _gc_timer->register_gc_start(os::elapsed_counter());
+  _gc_timer->register_gc_start();
   DefNewTracer gc_tracer;
   gc_tracer.report_gc_start(gch->gc_cause(), _gc_timer->gc_start());
 
@@ -709,7 +709,7 @@ void DefNewGeneration::collect(bool   full,
   gch->trace_heap_after_gc(&gc_tracer);
   gc_tracer.report_tenuring_threshold(tenuring_threshold());
 
-  _gc_timer->register_gc_end(os::elapsed_counter());
+  _gc_timer->register_gc_end();
 
   gc_tracer.report_gc_end(_gc_timer->gc_end(), _gc_timer->time_partitions());
 }

hotspot/src/share/vm/memory/generation.cpp

@@ -635,16 +635,16 @@ void OneContigSpaceCardGeneration::collect(bool   full,
     x(ref_processor(), gch->reserved_region());
 
   STWGCTimer* gc_timer = GenMarkSweep::gc_timer();
-  gc_timer->register_gc_start(os::elapsed_counter());
+  gc_timer->register_gc_start();
 
   SerialOldTracer* gc_tracer = GenMarkSweep::gc_tracer();
   gc_tracer->report_gc_start(gch->gc_cause(), gc_timer->gc_start());
 
   GenMarkSweep::invoke_at_safepoint(_level, ref_processor(), clear_all_soft_refs);
 
-  gc_timer->register_gc_end(os::elapsed_counter());
+  gc_timer->register_gc_end();
 
-  gc_tracer->report_gc_end(os::elapsed_counter(), gc_timer->time_partitions());
+  gc_tracer->report_gc_end(gc_timer->gc_end(), gc_timer->time_partitions());
 
   SpecializationStats::print();
 }

hotspot/src/share/vm/opto/compile.hpp

@@ -42,6 +42,7 @@
 #include "runtime/deoptimization.hpp"
 #include "runtime/vmThread.hpp"
 #include "trace/tracing.hpp"
+#include "utilities/ticks.hpp"
 
 class Block;
 class Bundle;
@@ -597,20 +598,19 @@ class Compile : public Phase {
   bool              has_method_handle_invokes() const { return _has_method_handle_invokes;     }
   void          set_has_method_handle_invokes(bool z) {        _has_method_handle_invokes = z; }
 
-  jlong _latest_stage_start_counter;
+  Ticks _latest_stage_start_counter;
 
   void begin_method() {
 #ifndef PRODUCT
     if (_printer) _printer->begin_method(this);
 #endif
-    C->_latest_stage_start_counter = os::elapsed_counter();
+    C->_latest_stage_start_counter.stamp();
   }
 
   void print_method(CompilerPhaseType cpt, int level = 1) {
-    EventCompilerPhase event(UNTIMED);
+    EventCompilerPhase event;
     if (event.should_commit()) {
       event.set_starttime(C->_latest_stage_start_counter);
-      event.set_endtime(os::elapsed_counter());
       event.set_phase((u1) cpt);
       event.set_compileID(C->_compile_id);
       event.set_phaseLevel(level);
@@ -621,14 +621,13 @@ class Compile : public Phase {
 #ifndef PRODUCT
     if (_printer) _printer->print_method(this, CompilerPhaseTypeHelper::to_string(cpt), level);
 #endif
-    C->_latest_stage_start_counter = os::elapsed_counter();
+    C->_latest_stage_start_counter.stamp();
   }
 
   void end_method(int level = 1) {
-    EventCompilerPhase event(UNTIMED);
+    EventCompilerPhase event;
     if (event.should_commit()) {
       event.set_starttime(C->_latest_stage_start_counter);
-      event.set_endtime(os::elapsed_counter());
       event.set_phase((u1) PHASE_END);
       event.set_compileID(C->_compile_id);
       event.set_phaseLevel(level);

hotspot/src/share/vm/runtime/sweeper.cpp

@@ -38,6 +38,7 @@
 #include "runtime/vm_operations.hpp"
 #include "trace/tracing.hpp"
 #include "utilities/events.hpp"
+#include "utilities/ticks.inline.hpp"
 #include "utilities/xmlstream.hpp"
 
 #ifdef ASSERT
@@ -144,10 +145,10 @@ volatile int  NMethodSweeper::_bytes_changed           = 0;    // Counts the tot
                                                                //   3) zombie      -> marked_for_reclamation
 
 int   NMethodSweeper::_total_nof_methods_reclaimed     = 0;    // Accumulated nof methods flushed
-jlong NMethodSweeper::_total_time_sweeping             = 0;    // Accumulated time sweeping
+Tickspan NMethodSweeper::_total_time_sweeping;                 // Accumulated time sweeping
-jlong NMethodSweeper::_total_time_this_sweep           = 0;    // Total time this sweep
+Tickspan NMethodSweeper::_total_time_this_sweep;               // Total time this sweep
-jlong NMethodSweeper::_peak_sweep_time                 = 0;    // Peak time for a full sweep
+Tickspan NMethodSweeper::_peak_sweep_time;                     // Peak time for a full sweep
-jlong NMethodSweeper::_peak_sweep_fraction_time        = 0;    // Peak time sweeping one fraction
+Tickspan NMethodSweeper::_peak_sweep_fraction_time;            // Peak time sweeping one fraction
 int   NMethodSweeper::_hotness_counter_reset_val       = 0;
 
 
@@ -209,7 +210,7 @@ void NMethodSweeper::mark_active_nmethods() {
     _sweep_fractions_left = NmethodSweepFraction;
     _current = CodeCache::first_nmethod();
     _traversals += 1;
-    _total_time_this_sweep = 0;
+    _total_time_this_sweep = Tickspan();
 
     if (PrintMethodFlushing) {
       tty->print_cr("### Sweep: stack traversal %d", _traversals);
@@ -303,7 +304,7 @@ void NMethodSweeper::possibly_sweep() {
 }
 
 void NMethodSweeper::sweep_code_cache() {
-  jlong sweep_start_counter = os::elapsed_counter();
+  Ticks sweep_start_counter = Ticks::now();
 
   _flushed_count                = 0;
   _zombified_count              = 0;
@@ -367,8 +368,8 @@ void NMethodSweeper::sweep_code_cache() {
 
   assert(_sweep_fractions_left > 1 || _current == NULL, "must have scanned the whole cache");
 
-  jlong sweep_end_counter = os::elapsed_counter();
+  const Ticks sweep_end_counter = Ticks::now();
-  jlong sweep_time = sweep_end_counter - sweep_start_counter;
+  const Tickspan sweep_time = sweep_end_counter - sweep_start_counter;
   _total_time_sweeping  += sweep_time;
   _total_time_this_sweep += sweep_time;
   _peak_sweep_fraction_time = MAX2(sweep_time, _peak_sweep_fraction_time);
@@ -389,7 +390,8 @@ void NMethodSweeper::sweep_code_cache() {
 
 #ifdef ASSERT
   if(PrintMethodFlushing) {
-    tty->print_cr("### sweeper:      sweep time(%d): " INT64_FORMAT, _sweep_fractions_left, (jlong)sweep_time);
+    tty->print_cr("### sweeper:      sweep time(%d): "
+      INT64_FORMAT, _sweep_fractions_left, (jlong)sweep_time.value());
   }
 #endif
 

hotspot/src/share/vm/runtime/sweeper.hpp

@@ -25,6 +25,7 @@
 #ifndef SHARE_VM_RUNTIME_SWEEPER_HPP
 #define SHARE_VM_RUNTIME_SWEEPER_HPP
 
+#include "utilities/ticks.hpp"
 // An NmethodSweeper is an incremental cleaner for:
 //    - cleanup inline caches
 //    - reclamation of nmethods
@@ -71,10 +72,10 @@ class NMethodSweeper : public AllStatic {
                                                   //   3) zombie      -> marked_for_reclamation
   // Stat counters
   static int       _total_nof_methods_reclaimed;  // Accumulated nof methods flushed
-  static jlong     _total_time_sweeping;          // Accumulated time sweeping
+  static Tickspan  _total_time_sweeping;          // Accumulated time sweeping
-  static jlong     _total_time_this_sweep;        // Total time this sweep
+  static Tickspan  _total_time_this_sweep;        // Total time this sweep
-  static jlong     _peak_sweep_time;              // Peak time for a full sweep
+  static Tickspan  _peak_sweep_time;              // Peak time for a full sweep
-  static jlong     _peak_sweep_fraction_time;     // Peak time sweeping one fraction
+  static Tickspan  _peak_sweep_fraction_time;     // Peak time sweeping one fraction
 
   static int  process_nmethod(nmethod *nm);
   static void release_nmethod(nmethod* nm);
@@ -87,9 +88,9 @@ class NMethodSweeper : public AllStatic {
  public:
   static long traversal_count()              { return _traversals; }
   static int  total_nof_methods_reclaimed()  { return _total_nof_methods_reclaimed; }
-  static jlong total_time_sweeping()         { return _total_time_sweeping; }
+  static const Tickspan total_time_sweeping()      { return _total_time_sweeping; }
-  static jlong peak_sweep_time()             { return _peak_sweep_time; }
+  static const Tickspan peak_sweep_time()          { return _peak_sweep_time; }
-  static jlong peak_sweep_fraction_time()    { return _peak_sweep_fraction_time; }
+  static const Tickspan peak_sweep_fraction_time() { return _peak_sweep_fraction_time; }
   static void log_sweep(const char* msg, const char* format = NULL, ...);
 
 

hotspot/src/share/vm/trace/noTraceBackend.hpp

@@ -25,9 +25,7 @@
 #define SHARE_VM_TRACE_NOTRACEBACKEND_HPP
 
 #include "prims/jni.h"
-
+#include "trace/traceTime.hpp"
-typedef jlong TracingTime;
-typedef jlong RelativeTracingTime;
 
 class NoTraceBackend {
 public:
@@ -44,5 +42,3 @@ public:
 typedef NoTraceBackend Tracing;
 
 #endif
-
-

hotspot/src/share/vm/trace/trace.xml

@@ -176,8 +176,8 @@ Declares a structure type that can be used in other events.
       <value type="UINT" field="gcId"  label="GC ID" relation="GC_ID" />
       <value type="GCNAME" field="name" label="Name" description="The name of the Garbage Collector" />
       <value type="GCCAUSE" field="cause" label="Cause" description="The reason for triggering this Garbage Collection" />
-      <value type="RELATIVE_TICKS" field="sumOfPauses" label="Sum of Pauses" description="Sum of all the times in which Java execution was paused during the garbage collection" />
+      <value type="TICKSPAN" field="sumOfPauses" label="Sum of Pauses" description="Sum of all the times in which Java execution was paused during the garbage collection" />
-      <value type="RELATIVE_TICKS" field="longestPause" label="Longest Pause" description="Longest individual pause during the garbage collection" />
+      <value type="TICKSPAN" field="longestPause" label="Longest Pause" description="Longest individual pause during the garbage collection" />
     </event>
 
     <event id="GCParallelOld" path="vm/gc/collector/parold_garbage_collection" label="Parallel Old Garbage Collection"

hotspot/src/share/vm/trace/traceBackend.hpp

@@ -47,10 +47,6 @@ public:
     return os::elapsed_counter();
   }
 
-  static TracingTime time_adjustment(jlong time) {
-    return time;
-  }
-
   static void on_unloading_classes(void) {
   }
 };

hotspot/src/share/vm/trace/traceEvent.hpp

@@ -25,26 +25,23 @@
 #ifndef SHARE_VM_TRACE_TRACEEVENT_HPP
 #define SHARE_VM_TRACE_TRACEEVENT_HPP
 
+#include "utilities/macros.hpp"
+
 enum EventStartTime {
   UNTIMED,
   TIMED
 };
 
-#include "utilities/macros.hpp"
-
 #if INCLUDE_TRACE
 
 #include "trace/traceBackend.hpp"
 #include "trace/tracing.hpp"
 #include "tracefiles/traceEventIds.hpp"
 #include "tracefiles/traceTypes.hpp"
+#include "utilities/ticks.hpp"
 
 template<typename T>
 class TraceEvent : public StackObj {
- protected:
-  jlong _startTime;
-  jlong _endTime;
-
  private:
   bool _started;
 #ifdef ASSERT
@@ -54,6 +51,18 @@ class TraceEvent : public StackObj {
   bool _ignore_check;
 #endif
 
+ protected:
+  jlong _startTime;
+  jlong _endTime;
+
+  void set_starttime(const TracingTime& time) {
+    _startTime = time;
+  }
+
+  void set_endtime(const TracingTime& time) {
+    _endTime = time;
+  }
+
  public:
   TraceEvent(EventStartTime timing=TIMED) :
     _startTime(0),
@@ -100,12 +109,12 @@ class TraceEvent : public StackObj {
     set_commited();
   }
 
-  void set_starttime(jlong time) {
+  void set_starttime(const Ticks& time) {
-    _startTime = time;
+    _startTime = time.value();
   }
 
-  void set_endtime(jlong time) {
+  void set_endtime(const Ticks& time) {
-    _endTime = time;
+    _endTime = time.value();
   }
 
   TraceEventId id() const {

hotspot/src/share/vm/trace/traceEventClasses.xsl

@@ -40,6 +40,7 @@
 #include "tracefiles/traceTypes.hpp"
 #include "trace/traceEvent.hpp"
 #include "utilities/macros.hpp"
+#include "utilities/ticks.hpp"
 
 #if INCLUDE_TRACE
 
@@ -55,8 +56,8 @@
 class TraceEvent {
 public:
   TraceEvent() {}
-  void set_starttime(jlong time) const {}
+  void set_starttime(const Ticks& time) {}
-  void set_endtime(jlong time) const {}
+  void set_endtime(const Ticks& time) {}
   bool should_commit() const { return false; }
   void commit() const {}
 };
@@ -170,23 +171,23 @@ public:
   </xsl:if>
 </xsl:template>
 
-
 <xsl:template match="value[@type='TICKS']" mode="write-setters">
 #if INCLUDE_TRACE
-  <xsl:value-of select="concat('void set_', @field, '(jlong time) { _', @field, ' = time; }')"/>
+<xsl:value-of select="concat('  void set_', @field, '(const Ticks&amp; time) { _', @field, ' = time; }')"/>
 #else
-  <xsl:value-of select="concat('void set_', @field, '(jlong ignore) {}')"/>
+<xsl:value-of select="concat('  void set_', @field, '(const Ticks&amp; ignore) {}')"/>
 #endif
 </xsl:template>
 
-<xsl:template match="value[@type='RELATIVE_TICKS']" mode="write-setters">
+<xsl:template match="value[@type='TICKSPAN']" mode="write-setters">
 #if INCLUDE_TRACE
-  <xsl:value-of select="concat('void set_', @field, '(jlong time) { _', @field, ' = time; }')"/>
+  <xsl:value-of select="concat('  void set_', @field, '(const Tickspan&amp; time) { _', @field, ' = time; }')"/>
 #else
-  <xsl:value-of select="concat('void set_', @field, '(jlong ignore) {}')"/>
+  <xsl:value-of select="concat('  void set_', @field, '(const Tickspan&amp; ignore) {}')"/>
 #endif
 </xsl:template>
 
+
 <xsl:template match="value" mode="write-fields">
   <xsl:variable name="type" select="@type"/>
   <xsl:variable name="wt" select="//primary_type[@symbol=$type]/@type"/>
@@ -226,7 +227,17 @@ public:
 <xsl:template match="value" mode="write-data">
   <xsl:variable name="type" select="@type"/>
   <xsl:variable name="wt" select="//primary_type[@symbol=$type]/@writetype"/>
-  <xsl:value-of select="concat('    ts.print_val(&quot;', @label, '&quot;, _', @field, ');')"/>
+  <xsl:choose>
+    <xsl:when test="@type='TICKSPAN'">
+      <xsl:value-of select="concat('    ts.print_val(&quot;', @label, '&quot;, _', @field, '.value());')"/>
+    </xsl:when>
+    <xsl:when test="@type='TICKS'">
+      <xsl:value-of select="concat('    ts.print_val(&quot;', @label, '&quot;, _', @field, '.value());')"/>
+    </xsl:when>
+    <xsl:otherwise>
+      <xsl:value-of select="concat('    ts.print_val(&quot;', @label, '&quot;, _', @field, ');')"/>
+    </xsl:otherwise>
+  </xsl:choose>
   <xsl:if test="position() != last()">
     <xsl:text>
     ts.print(", ");

hotspot/src/share/vm/trace/traceTime.hpp

@@ -28,6 +28,5 @@
 #include "prims/jni.h"
 
 typedef jlong TracingTime;
-typedef jlong RelativeTracingTime;
 
-#endif
+#endif // SHARE_VM_TRACE_TRACETIME_HPP

hotspot/src/share/vm/trace/traceTypes.xsl

@@ -32,9 +32,11 @@
 #ifndef TRACEFILES_JFRTYPES_HPP
 #define TRACEFILES_JFRTYPES_HPP
 
+#include "oops/symbol.hpp"
 #include "trace/traceDataTypes.hpp"
 #include "utilities/globalDefinitions.hpp"
-#include "oops/symbol.hpp"
+#include "utilities/ticks.hpp"
+
 
 enum JVMContentType {
   _not_a_content_type = (JVM_CONTENT_TYPES_START - 1),

hotspot/src/share/vm/trace/tracetypes.xml

@@ -249,13 +249,13 @@ Now we can use the content + data type in declaring event fields.
     <primary_type symbol="NANOS" datatype="LONG" contenttype="NANOS"
                   type="s8" sizeop="sizeof(s8)"/>
 
-    <!-- 64-bit signed integer, SEMANTIC value ABSOLUTE TICKS -->
+    <!-- 64-bit signed integer, SEMANTIC value TICKS -->
     <primary_type symbol="TICKS" datatype="LONG" contenttype="TICKS"
-                  type="s8" sizeop="sizeof(s8)"/>
+                  type="Ticks" sizeop="sizeof(s8)"/>
 
-    <!-- 64-bit signed integer, SEMANTIC value RELATIVE TICKS -->
+    <!-- 64-bit signed integer, SEMANTIC value TICKS duration -->
-    <primary_type symbol="RELATIVE_TICKS" datatype="LONG" contenttype="TICKS"
+    <primary_type symbol="TICKSPAN" datatype="LONG" contenttype="TICKS"
-                  type="s8" sizeop="sizeof(s8)"/>
+                  type="Tickspan" sizeop="sizeof(s8)"/>
 
     <!-- 64-bit unsigned integer, SEMANTIC value ADDRESS (mem loc) -->
     <primary_type symbol="ADDRESS" datatype="U8" contenttype="ADDRESS"

hotspot/src/share/vm/utilities/ticks.cpp

@@ -0,0 +1,68 @@
+/*
+ * Copyright (c) 2013, 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
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ *
+ */
+
+#include "precompiled.hpp"
+#include "runtime/os.hpp"
+#include "utilities/ticks.inline.hpp"
+
+#ifdef ASSERT
+ const jlong Ticks::invalid_time_stamp = -2; // 0xFFFF FFFF`FFFF FFFE
+#endif
+
+void Ticks::stamp() {
+  _stamp_ticks = os::elapsed_counter();
+}
+
+const Ticks Ticks::now() {
+  Ticks t;
+  t.stamp();
+  return t;
+}
+
+Tickspan::Tickspan(const Ticks& end, const Ticks& start) {
+  assert(end.value() != Ticks::invalid_time_stamp, "end is unstamped!");
+  assert(start.value() != Ticks::invalid_time_stamp, "start is unstamped!");
+
+  assert(end >= start, "negative time!");
+
+  _span_ticks = end.value() - start.value();
+}
+
+template <typename ReturnType>
+static ReturnType time_conversion(const Tickspan& span, TicksToTimeHelper::Unit unit) {
+  assert(TicksToTimeHelper::SECONDS == unit ||
+         TicksToTimeHelper::MILLISECONDS == unit, "invalid unit!");
+
+  ReturnType frequency_per_unit = (ReturnType)os::elapsed_frequency() / (ReturnType)unit;
+
+  return (ReturnType) ((ReturnType)span.value() / frequency_per_unit);
+}
+
+double TicksToTimeHelper::seconds(const Tickspan& span) {
+  return time_conversion<double>(span, SECONDS);
+}
+
+jlong TicksToTimeHelper::milliseconds(const Tickspan& span) {
+  return time_conversion<jlong>(span, MILLISECONDS);
+}

hotspot/src/share/vm/utilities/ticks.hpp

@@ -0,0 +1,111 @@
+/*
+ * Copyright (c) 2013, 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
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ *
+ */
+
+#ifndef SHARE_VM_UTILITIES_TICKS_HPP
+#define SHARE_VM_UTILITIES_TICKS_HPP
+
+#include "memory/allocation.hpp"
+#include "utilities/globalDefinitions.hpp"
+
+class Ticks;
+
+class Tickspan VALUE_OBJ_CLASS_SPEC {
+  friend class Ticks;
+  friend Tickspan operator-(const Ticks& end, const Ticks& start);
+
+ private:
+  jlong _span_ticks;
+
+  Tickspan(const Ticks& end, const Ticks& start);
+
+ public:
+  Tickspan() : _span_ticks(0) {}
+
+  Tickspan& operator+=(const Tickspan& rhs) {
+    _span_ticks += rhs._span_ticks;
+    return *this;
+  }
+
+  jlong value() const {
+    return _span_ticks;
+  }
+
+};
+
+class Ticks VALUE_OBJ_CLASS_SPEC {
+ private:
+  jlong _stamp_ticks;
+
+ public:
+  Ticks() : _stamp_ticks(0) {
+    assert((_stamp_ticks = invalid_time_stamp) == invalid_time_stamp,
+      "initial unstamped time value assignment");
+  }
+
+  Ticks& operator+=(const Tickspan& span) {
+    _stamp_ticks += span.value();
+    return *this;
+  }
+
+  Ticks& operator-=(const Tickspan& span) {
+    _stamp_ticks -= span.value();
+    return *this;
+  }
+
+  void stamp();
+
+  jlong value() const {
+    return _stamp_ticks;
+  }
+
+  static const Ticks now();
+
+#ifdef ASSERT
+  static const jlong invalid_time_stamp;
+#endif
+
+#ifndef PRODUCT
+  // only for internal use by GC VM tests
+  friend class TimePartitionPhasesIteratorTest;
+  friend class GCTimerTest;
+
+ private:
+  // implicit type conversion
+  Ticks(int ticks) : _stamp_ticks(ticks) {}
+
+#endif // !PRODUCT
+
+};
+
+class TicksToTimeHelper : public AllStatic {
+ public:
+  enum Unit {
+    SECONDS = 1,
+    MILLISECONDS = 1000
+  };
+  static double seconds(const Tickspan& span);
+  static jlong milliseconds(const Tickspan& span);
+};
+
+#endif // SHARE_VM_UTILITIES_TICKS_HPP

hotspot/src/share/vm/utilities/ticks.inline.hpp

@@ -0,0 +1,97 @@
+/*
+ * Copyright (c) 2013, 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
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ *
+ */
+
+#ifndef SHARE_VM_UTILITIES_TICKS_INLINE_HPP
+#define SHARE_VM_UTILITIES_TICKS_INLINE_HPP
+
+#include "utilities/ticks.hpp"
+
+inline Tickspan operator+(Tickspan lhs, const Tickspan& rhs) {
+  lhs += rhs;
+  return lhs;
+}
+
+inline bool operator==(const Tickspan& lhs, const Tickspan& rhs) {
+  return lhs.value() == rhs.value();
+}
+
+inline bool operator!=(const Tickspan& lhs, const Tickspan& rhs) {
+  return !operator==(lhs,rhs);
+}
+
+inline bool operator<(const Tickspan& lhs, const Tickspan& rhs) {
+  return lhs.value() < rhs.value();
+}
+
+inline bool operator>(const Tickspan& lhs, const Tickspan& rhs) {
+  return operator<(rhs,lhs);
+}
+
+inline bool operator<=(const Tickspan& lhs, const Tickspan& rhs) {
+  return !operator>(lhs,rhs);
+}
+
+inline bool operator>=(const Tickspan& lhs, const Tickspan& rhs) {
+  return !operator<(lhs,rhs);
+}
+
+inline Ticks operator+(Ticks lhs, const Tickspan& span) {
+  lhs += span;
+  return lhs;
+}
+
+inline Ticks operator-(Ticks lhs, const Tickspan& span) {
+  lhs -= span;
+  return lhs;
+}
+
+inline Tickspan operator-(const Ticks& end, const Ticks& start) {
+  return Tickspan(end, start);
+}
+
+inline bool operator==(const Ticks& lhs, const Ticks& rhs) {
+  return lhs.value() == rhs.value();
+}
+
+inline bool operator!=(const Ticks& lhs, const Ticks& rhs) {
+  return !operator==(lhs,rhs);
+}
+
+inline bool operator<(const Ticks& lhs, const Ticks& rhs) {
+  return lhs.value() < rhs.value();
+}
+
+inline bool operator>(const Ticks& lhs, const Ticks& rhs) {
+  return operator<(rhs,lhs);
+}
+
+inline bool operator<=(const Ticks& lhs, const Ticks& rhs) {
+  return !operator>(lhs,rhs);
+}
+
+inline bool operator>=(const Ticks& lhs, const Ticks& rhs) {
+  return !operator<(lhs,rhs);
+}
+
+#endif // SHARE_VM_UTILITIES_TICKS_INLINE_HPP