Merge

src/share/vm/gc_implementation/g1/concurrentMark.hpp

@@ -353,6 +353,10 @@ class ConcurrentMark: public CHeapObj {
   friend class CMConcurrentMarkingTask;
   friend class G1ParNoteEndTask;
   friend class CalcLiveObjectsClosure;
+  friend class G1RefProcTaskProxy;
+  friend class G1RefProcTaskExecutor;
+  friend class G1CMParKeepAliveAndDrainClosure;
+  friend class G1CMParDrainMarkingStackClosure;
 
 protected:
   ConcurrentMarkThread* _cmThread;   // the thread doing the work
@@ -936,7 +940,7 @@ private:
   // if this is true, then the task has aborted for some reason
   bool                        _has_aborted;
   // set when the task aborts because it has met its time quota
-  bool                        _has_aborted_timed_out;
+  bool                        _has_timed_out;
   // true when we're draining SATB buffers; this avoids the task
   // aborting due to SATB buffers being available (as we're already
   // dealing with them)
@@ -1041,7 +1045,7 @@ public:
   // trying not to exceed the given duration. However, it might exit
   // prematurely, according to some conditions (i.e. SATB buffers are
   // available for processing).
-  void do_marking_step(double target_ms);
+  void do_marking_step(double target_ms, bool do_stealing, bool do_termination);
 
   // These two calls start and stop the timer
   void record_start_time() {
@@ -1063,6 +1067,7 @@ public:
   bool has_aborted()            { return _has_aborted; }
   void set_has_aborted()        { _has_aborted = true; }
   void clear_has_aborted()      { _has_aborted = false; }
+  bool has_timed_out()          { return _has_timed_out; }
   bool claimed()                { return _claimed; }
 
   // Support routines for the partially scanned region that may be

src/share/vm/gc_implementation/g1/concurrentMarkThread.cpp

@@ -251,7 +251,9 @@ void ConcurrentMarkThread::run() {
 
         // Now do the remainder of the cleanup operation.
         _cm->completeCleanup();
+        _sts.join();
         g1_policy->record_concurrent_mark_cleanup_completed();
+        _sts.leave();
 
         double cleanup_end_sec = os::elapsedTime();
         if (PrintGC) {

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

@@ -4925,10 +4925,11 @@ void G1CollectedHeap::evacuate_collection_set() {
   COMPILER2_PRESENT(DerivedPointerTable::update_pointers());
 }
 
-void G1CollectedHeap::free_region_if_totally_empty(HeapRegion* hr,
+void G1CollectedHeap::free_region_if_empty(HeapRegion* hr,
                                      size_t* pre_used,
                                      FreeRegionList* free_list,
                                      HumongousRegionSet* humongous_proxy_set,
+                                     HRRSCleanupTask* hrrs_cleanup_task,
                                      bool par) {
   if (hr->used() > 0 && hr->max_live_bytes() == 0 && !hr->is_young()) {
     if (hr->isHumongous()) {
@@ -4937,6 +4938,8 @@ void G1CollectedHeap::free_region_if_totally_empty(HeapRegion* hr,
     } else {
       free_region(hr, pre_used, free_list, par);
     }
+  } else {
+    hr->rem_set()->do_cleanup_work(hrrs_cleanup_task);
   }
 }
 

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

@@ -40,6 +40,7 @@
 
 class HeapRegion;
 class HeapRegionSeq;
+class HRRSCleanupTask;
 class PermanentGenerationSpec;
 class GenerationSpec;
 class OopsInHeapRegionClosure;
@@ -1099,10 +1100,11 @@ public:
   // all dead. It calls either free_region() or
   // free_humongous_region() depending on the type of the region that
   // is passed to it.
-  void free_region_if_totally_empty(HeapRegion* hr,
+  void free_region_if_empty(HeapRegion* hr,
                             size_t* pre_used,
                             FreeRegionList* free_list,
                             HumongousRegionSet* humongous_proxy_set,
+                            HRRSCleanupTask* hrrs_cleanup_task,
                             bool par);
 
   // It appends the free list to the master free list and updates the

src/share/vm/gc_implementation/g1/g1_globals.hpp

@@ -81,6 +81,14 @@
   product(intx, G1MarkRegionStackSize, 1024 * 1024,                         \
           "Size of the region stack for concurrent marking.")               \
                                                                             \
+  product(double, G1ConcMarkStepDurationMillis, 10.0,                       \
+          "Target duration of individual concurrent marking steps "         \
+          "in milliseconds.")                                               \
+                                                                            \
+  product(intx, G1RefProcDrainInterval, 10,                                 \
+          "The number of discovered reference objects to process before "   \
+          "draining concurrent marking work queues.")                       \
+                                                                            \
   develop(bool, G1SATBBarrierPrintNullPreVals, false,                       \
           "If true, count frac of ptr writes with null pre-vals.")          \
                                                                             \

src/share/vm/gc_implementation/g1/heapRegionRemSet.cpp

 /*
- * Copyright (c) 2001, 2010, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2001, 2011, 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
@@ -463,7 +463,6 @@ public:
   }
 
   static void par_contract_all();
-
 };
 
 void PosParPRT::par_contract_all() {
@@ -1070,6 +1069,11 @@ bool OtherRegionsTable::contains_reference_locked(OopOrNarrowOopStar from) const
 
 }
 
+void
+OtherRegionsTable::do_cleanup_work(HRRSCleanupTask* hrrs_cleanup_task) {
+  _sparse_table.do_cleanup_work(hrrs_cleanup_task);
+}
+
 // Determines how many threads can add records to an rset in parallel.
 // This can be done by either mutator threads together with the
 // concurrent refinement threads or GC threads.
@@ -1384,6 +1388,19 @@ void HeapRegionRemSet::print_recorded() {
   }
 }
 
+void HeapRegionRemSet::reset_for_cleanup_tasks() {
+  SparsePRT::reset_for_cleanup_tasks();
+}
+
+void HeapRegionRemSet::do_cleanup_work(HRRSCleanupTask* hrrs_cleanup_task) {
+  _other_regions.do_cleanup_work(hrrs_cleanup_task);
+}
+
+void
+HeapRegionRemSet::finish_cleanup_task(HRRSCleanupTask* hrrs_cleanup_task) {
+  SparsePRT::finish_cleanup_task(hrrs_cleanup_task);
+}
+
 #ifndef PRODUCT
 void HeapRegionRemSet::test() {
   os::sleep(Thread::current(), (jlong)5000, false);

src/share/vm/gc_implementation/g1/heapRegionRemSet.hpp

 /*
- * Copyright (c) 2001, 2010, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2001, 2011, 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
@@ -38,6 +38,10 @@ class HeapRegionRemSetIterator;
 class PosParPRT;
 class SparsePRT;
 
+// Essentially a wrapper around SparsePRTCleanupTask. See
+// sparsePRT.hpp for more details.
+class HRRSCleanupTask : public SparsePRTCleanupTask {
+};
 
 // The "_coarse_map" is a bitmap with one bit for each region, where set
 // bits indicate that the corresponding region may contain some pointer
@@ -156,6 +160,8 @@ public:
   // "from_hr" is being cleared; remove any entries from it.
   void clear_incoming_entry(HeapRegion* from_hr);
 
+  void do_cleanup_work(HRRSCleanupTask* hrrs_cleanup_task);
+
   // Declare the heap size (in # of regions) to the OtherRegionsTable.
   // (Uses it to initialize from_card_cache).
   static void init_from_card_cache(size_t max_regions);
@@ -165,10 +171,8 @@ public:
   static void shrink_from_card_cache(size_t new_n_regs);
 
   static void print_from_card_cache();
-
 };
 
-
 class HeapRegionRemSet : public CHeapObj {
   friend class VMStructs;
   friend class HeapRegionRemSetIterator;
@@ -342,11 +346,16 @@ public:
   static void print_recorded();
   static void record_event(Event evnt);
 
+  // These are wrappers for the similarly-named methods on
+  // SparsePRT. Look at sparsePRT.hpp for more details.
+  static void reset_for_cleanup_tasks();
+  void do_cleanup_work(HRRSCleanupTask* hrrs_cleanup_task);
+  static void finish_cleanup_task(HRRSCleanupTask* hrrs_cleanup_task);
+
   // Run unit tests.
 #ifndef PRODUCT
   static void test();
 #endif
-
 };
 
 class HeapRegionRemSetIterator : public CHeapObj {

src/share/vm/gc_implementation/g1/heapRegionSeq.cpp

@@ -195,10 +195,10 @@ int HeapRegionSeq::find_contiguous(size_t num) {
     assert(0 <= res && res < _regions.length(),
            err_msg("res: %d should be valid", res));
     _alloc_search_start = res + (int) num;
-  }
     assert(0 < _alloc_search_start && _alloc_search_start <= _regions.length(),
            err_msg("_alloc_search_start: %d should be valid",
                    _alloc_search_start));
+  }
   return res;
 }
 

src/share/vm/gc_implementation/g1/sparsePRT.cpp

 /*
- * Copyright (c) 2001, 2010, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2001, 2011, 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
@@ -415,6 +415,38 @@ SparsePRT* SparsePRT::get_from_expanded_list() {
   return NULL;
 }
 
+void SparsePRT::reset_for_cleanup_tasks() {
+  _head_expanded_list = NULL;
+}
+
+void SparsePRT::do_cleanup_work(SparsePRTCleanupTask* sprt_cleanup_task) {
+  if (should_be_on_expanded_list()) {
+    sprt_cleanup_task->add(this);
+  }
+}
+
+void SparsePRT::finish_cleanup_task(SparsePRTCleanupTask* sprt_cleanup_task) {
+  assert(ParGCRareEvent_lock->owned_by_self(), "pre-condition");
+  SparsePRT* head = sprt_cleanup_task->head();
+  SparsePRT* tail = sprt_cleanup_task->tail();
+  if (head != NULL) {
+    assert(tail != NULL, "if head is not NULL, so should tail");
+
+    tail->set_next_expanded(_head_expanded_list);
+    _head_expanded_list = head;
+  } else {
+    assert(tail == NULL, "if head is NULL, so should tail");
+  }
+}
+
+bool SparsePRT::should_be_on_expanded_list() {
+  if (_expanded) {
+    assert(_cur != _next, "if _expanded is true, cur should be != _next");
+  } else {
+    assert(_cur == _next, "if _expanded is false, cur should be == _next");
+  }
+  return expanded();
+}
 
 void SparsePRT::cleanup_all() {
   // First clean up all expanded tables so they agree on next and cur.
@@ -484,6 +516,7 @@ void SparsePRT::clear() {
     _cur->clear();
   }
   _next = _cur;
+  _expanded = false;
 }
 
 void SparsePRT::cleanup() {
@@ -518,3 +551,15 @@ void SparsePRT::expand() {
   }
   add_to_expanded_list(this);
 }
+
+void SparsePRTCleanupTask::add(SparsePRT* sprt) {
+  assert(sprt->should_be_on_expanded_list(), "pre-condition");
+
+  sprt->set_next_expanded(NULL);
+  if (_tail != NULL) {
+    _tail->set_next_expanded(sprt);
+  } else {
+    _head = sprt;
+  }
+  _tail = sprt;
+}

src/share/vm/gc_implementation/g1/sparsePRT.hpp

 /*
- * Copyright (c) 2001, 2010, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2001, 2011, 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
@@ -212,8 +212,11 @@ public:
 // mutex.
 
 class SparsePRTIter;
+class SparsePRTCleanupTask;
 
 class SparsePRT VALUE_OBJ_CLASS_SPEC {
+  friend class SparsePRTCleanupTask;
+
   //  Iterations are done on the _cur hash table, since they only need to
   //  see entries visible at the start of a collection pause.
   //  All other operations are done using the _next hash table.
@@ -238,6 +241,8 @@ class SparsePRT VALUE_OBJ_CLASS_SPEC {
   SparsePRT* next_expanded() { return _next_expanded; }
   void set_next_expanded(SparsePRT* nxt) { _next_expanded = nxt; }
 
+  bool should_be_on_expanded_list();
+
   static SparsePRT* _head_expanded_list;
 
 public:
@@ -284,12 +289,36 @@ public:
   static void add_to_expanded_list(SparsePRT* sprt);
   static SparsePRT* get_from_expanded_list();
 
+  // The purpose of these three methods is to help the GC workers
+  // during the cleanup pause to recreate the expanded list, purging
+  // any tables from it that belong to regions that are freed during
+  // cleanup (if we don't purge those tables, there is a race that
+  // causes various crashes; see CR 7014261).
+  //
+  // We chose to recreate the expanded list, instead of purging
+  // entries from it by iterating over it, to avoid this serial phase
+  // at the end of the cleanup pause.
+  //
+  // The three methods below work as follows:
+  // * reset_for_cleanup_tasks() : Nulls the expanded list head at the
+  //   start of the cleanup pause.
+  // * do_cleanup_work() : Called by the cleanup workers for every
+  //   region that is not free / is being freed by the cleanup
+  //   pause. It creates a list of expanded tables whose head / tail
+  //   are on the thread-local SparsePRTCleanupTask object.
+  // * finish_cleanup_task() : Called by the cleanup workers after
+  //   they complete their cleanup task. It adds the local list into
+  //   the global expanded list. It assumes that the
+  //   ParGCRareEvent_lock is being held to ensure MT-safety.
+  static void reset_for_cleanup_tasks();
+  void do_cleanup_work(SparsePRTCleanupTask* sprt_cleanup_task);
+  static void finish_cleanup_task(SparsePRTCleanupTask* sprt_cleanup_task);
+
   bool contains_card(RegionIdx_t region_id, CardIdx_t card_index) const {
     return _next->contains_card(region_id, card_index);
   }
 };
 
-
 class SparsePRTIter: public RSHashTableIter {
 public:
   void init(const SparsePRT* sprt) {
@@ -300,4 +329,22 @@ public:
   }
 };
 
+// This allows each worker during a cleanup pause to create a
+// thread-local list of sparse tables that have been expanded and need
+// to be processed at the beginning of the next GC pause. This lists
+// are concatenated into the single expanded list at the end of the
+// cleanup pause.
+class SparsePRTCleanupTask VALUE_OBJ_CLASS_SPEC {
+private:
+  SparsePRT* _head;
+  SparsePRT* _tail;
+
+public:
+  SparsePRTCleanupTask() : _head(NULL), _tail(NULL) { }
+
+  void add(SparsePRT* sprt);
+  SparsePRT* head() { return _head; }
+  SparsePRT* tail() { return _tail; }
+};
+
 #endif // SHARE_VM_GC_IMPLEMENTATION_G1_SPARSEPRT_HPP

src/share/vm/runtime/arguments.cpp

@@ -1941,10 +1941,16 @@ bool Arguments::check_vm_args_consistency() {
     status = false;
   }
 
+#ifndef SERIALGC
   if (UseG1GC) {
     status = status && verify_percentage(InitiatingHeapOccupancyPercent,
                                          "InitiatingHeapOccupancyPercent");
+    status = status && verify_min_value(G1RefProcDrainInterval, 1,
+                                        "G1RefProcDrainInterval");
+    status = status && verify_min_value((intx)G1ConcMarkStepDurationMillis, 1,
+                                        "G1ConcMarkStepDurationMillis");
   }
+#endif
 
   status = status && verify_interval(RefDiscoveryPolicy,
                                      ReferenceProcessor::DiscoveryPolicyMin,