--- a/src/share/vm/gc_implementation/g1/g1CollectedHeap.hpp	Tue Apr 01 14:09:03 2014 +0200
+++ b/src/share/vm/gc_implementation/g1/g1CollectedHeap.hpp	Tue Apr 01 13:57:07 2014 +0200
@@ -209,7 +209,7 @@
   friend class OldGCAllocRegion;
 
   // Closures used in implementation.
-  template <G1Barrier barrier, bool do_mark_object>
+  template <bool do_gen_barrier, G1Barrier barrier, bool do_mark_object>
   friend class G1ParCopyClosure;
   friend class G1IsAliveClosure;
   friend class G1EvacuateFollowersClosure;
@@ -606,11 +606,6 @@
   // may not be a humongous - it must fit into a single heap region.
   HeapWord* par_allocate_during_gc(GCAllocPurpose purpose, size_t word_size);
 
-  HeapWord* allocate_during_gc_slow(GCAllocPurpose purpose,
-                                    HeapRegion*    alloc_region,
-                                    bool           par,
-                                    size_t         word_size);
-
   // Ensure that no further allocations can happen in "r", bearing in mind
   // that parallel threads might be attempting allocations.
   void par_allocate_remaining_space(HeapRegion* r);
@@ -708,20 +703,23 @@
   }
 
   // This is a fast test on whether a reference points into the
-  // collection set or not. Assume that the reference
-  // points into the heap.
+  // collection set or not. It does not assume that the reference
+  // points into the heap; if it doesn't, it will return false.
   bool in_cset_fast_test(oop obj) {
     assert(_in_cset_fast_test != NULL, "sanity");
-    assert(_g1_committed.contains((HeapWord*) obj), err_msg("Given reference outside of heap, is "PTR_FORMAT, (HeapWord*)obj));
-    // no need to subtract the bottom of the heap from obj,
-    // _in_cset_fast_test is biased
-    uintx index = cast_from_oop<uintx>(obj) >> HeapRegion::LogOfHRGrainBytes;
-    bool ret = _in_cset_fast_test[index];
-    // let's make sure the result is consistent with what the slower
-    // test returns
-    assert( ret || !obj_in_cs(obj), "sanity");
-    assert(!ret ||  obj_in_cs(obj), "sanity");
-    return ret;
+    if (_g1_committed.contains((HeapWord*) obj)) {
+      // no need to subtract the bottom of the heap from obj,
+      // _in_cset_fast_test is biased
+      uintx index = cast_from_oop<uintx>(obj) >> HeapRegion::LogOfHRGrainBytes;
+      bool ret = _in_cset_fast_test[index];
+      // let's make sure the result is consistent with what the slower
+      // test returns
+      assert( ret || !obj_in_cs(obj), "sanity");
+      assert(!ret ||  obj_in_cs(obj), "sanity");
+      return ret;
+    } else {
+      return false;
+    }
   }
 
   void clear_cset_fast_test() {
@@ -840,6 +838,11 @@
                                G1KlassScanClosure* scan_klasses,
                                int worker_i);
 
+  // Apply "blk" to all the weak roots of the system.  These include
+  // JNI weak roots, the code cache, system dictionary, symbol table,
+  // string table, and referents of reachable weak refs.
+  void g1_process_weak_roots(OopClosure* root_closure);
+
   // Frees a non-humongous region by initializing its contents and
   // adding it to the free list that's passed as a parameter (this is
   // usually a local list which will be appended to the master free
@@ -1185,6 +1188,15 @@
   // end fields defining the extent of the contiguous allocation region.)
   // But G1CollectedHeap doesn't yet support this.
 
+  // Return an estimate of the maximum allocation that could be performed
+  // without triggering any collection or expansion activity.  In a
+  // generational collector, for example, this is probably the largest
+  // allocation that could be supported (without expansion) in the youngest
+  // generation.  It is "unsafe" because no locks are taken; the result
+  // should be treated as an approximation, not a guarantee, for use in
+  // heuristic resizing decisions.
+  virtual size_t unsafe_max_alloc();
+
   virtual bool is_maximal_no_gc() const {
     return _g1_storage.uncommitted_size() == 0;
   }
@@ -1375,7 +1387,7 @@
   // Divide the heap region sequence into "chunks" of some size (the number
   // of regions divided by the number of parallel threads times some
   // overpartition factor, currently 4).  Assumes that this will be called
-  // in parallel by ParallelGCThreads worker threads with distinct worker
+  // in parallel by ParallelGCThreads worker threads with discinct worker
   // ids in the range [0..max(ParallelGCThreads-1, 1)], that all parallel
   // calls will use the same "claim_value", and that that claim value is
   // different from the claim_value of any heap region before the start of
@@ -1472,11 +1484,9 @@
   // Section on thread-local allocation buffers (TLABs)
   // See CollectedHeap for semantics.
 
-  bool supports_tlab_allocation() const;
-  size_t tlab_capacity(Thread* ignored) const;
-  size_t tlab_used(Thread* ignored) const;
-  size_t max_tlab_size() const;
-  size_t unsafe_max_tlab_alloc(Thread* ignored) const;
+  virtual bool supports_tlab_allocation() const;
+  virtual size_t tlab_capacity(Thread* thr) const;
+  virtual size_t unsafe_max_tlab_alloc(Thread* thr) const;
 
   // Can a compiler initialize a new object without store barriers?
   // This permission only extends from the creation of a new object
@@ -1522,7 +1532,7 @@
   // Returns "true" iff the given word_size is "very large".
   static bool isHumongous(size_t word_size) {
     // Note this has to be strictly greater-than as the TLABs
-    // are capped at the humongous threshold and we want to
+    // are capped at the humongous thresold and we want to
     // ensure that we don't try to allocate a TLAB as
     // humongous and that we don't allocate a humongous
     // object in a TLAB.
@@ -1561,7 +1571,7 @@
   void set_region_short_lived_locked(HeapRegion* hr);
   // add appropriate methods for any other surv rate groups
 
-  YoungList* young_list() const { return _young_list; }
+  YoungList* young_list() { return _young_list; }
 
   // debugging
   bool check_young_list_well_formed() {
@@ -1652,30 +1662,26 @@
 
   // Optimized nmethod scanning support routines
 
-  // Register the given nmethod with the G1 heap.
+  // Register the given nmethod with the G1 heap
   virtual void register_nmethod(nmethod* nm);
 
-  // Unregister the given nmethod from the G1 heap.
+  // Unregister the given nmethod from the G1 heap
   virtual void unregister_nmethod(nmethod* nm);
 
   // Migrate the nmethods in the code root lists of the regions
   // in the collection set to regions in to-space. In the event
   // of an evacuation failure, nmethods that reference objects
-  // that were not successfully evacuated are not migrated.
+  // that were not successfullly evacuated are not migrated.
   void migrate_strong_code_roots();
 
   // During an initial mark pause, mark all the code roots that
   // point into regions *not* in the collection set.
   void mark_strong_code_roots(uint worker_id);
 
-  // Rebuild the strong code root lists for each region
-  // after a full GC.
+  // Rebuild the stong code root lists for each region
+  // after a full GC
   void rebuild_strong_code_roots();
 
-  // Delete entries for dead interned string and clean up unreferenced symbols
-  // in symbol table, possibly in parallel.
-  void unlink_string_and_symbol_table(BoolObjectClosure* is_alive, bool unlink_strings = true, bool unlink_symbols = true);
-
   // Verification
 
   // The following is just to alert the verification code
@@ -1781,6 +1787,95 @@
     ParGCAllocBuffer::retire(end_of_gc, retain);
     _retired = true;
   }
+
+  bool is_retired() {
+    return _retired;
+  }
+};
+
+class G1ParGCAllocBufferContainer {
+protected:
+  static int const _priority_max = 2;
+  G1ParGCAllocBuffer* _priority_buffer[_priority_max];
+
+public:
+  G1ParGCAllocBufferContainer(size_t gclab_word_size) {
+    for (int pr = 0; pr < _priority_max; ++pr) {
+      _priority_buffer[pr] = new G1ParGCAllocBuffer(gclab_word_size);
+    }
+  }
+
+  ~G1ParGCAllocBufferContainer() {
+    for (int pr = 0; pr < _priority_max; ++pr) {
+      assert(_priority_buffer[pr]->is_retired(), "alloc buffers should all retire at this point.");
+      delete _priority_buffer[pr];
+    }
+  }
+
+  HeapWord* allocate(size_t word_sz) {
+    HeapWord* obj;
+    for (int pr = 0; pr < _priority_max; ++pr) {
+      obj = _priority_buffer[pr]->allocate(word_sz);
+      if (obj != NULL) return obj;
+    }
+    return obj;
+  }
+
+  bool contains(void* addr) {
+    for (int pr = 0; pr < _priority_max; ++pr) {
+      if (_priority_buffer[pr]->contains(addr)) return true;
+    }
+    return false;
+  }
+
+  void undo_allocation(HeapWord* obj, size_t word_sz) {
+    bool finish_undo;
+    for (int pr = 0; pr < _priority_max; ++pr) {
+      if (_priority_buffer[pr]->contains(obj)) {
+        _priority_buffer[pr]->undo_allocation(obj, word_sz);
+        finish_undo = true;
+      }
+    }
+    if (!finish_undo) ShouldNotReachHere();
+  }
+
+  size_t words_remaining() {
+    size_t result = 0;
+    for (int pr = 0; pr < _priority_max; ++pr) {
+      result += _priority_buffer[pr]->words_remaining();
+    }
+    return result;
+  }
+
+  size_t words_remaining_in_retired_buffer() {
+    G1ParGCAllocBuffer* retired = _priority_buffer[0];
+    return retired->words_remaining();
+  }
+
+  void flush_stats_and_retire(PLABStats* stats, bool end_of_gc, bool retain) {
+    for (int pr = 0; pr < _priority_max; ++pr) {
+      _priority_buffer[pr]->flush_stats_and_retire(stats, end_of_gc, retain);
+    }
+  }
+
+  void update(bool end_of_gc, bool retain, HeapWord* buf, size_t word_sz) {
+    G1ParGCAllocBuffer* retired_and_set = _priority_buffer[0];
+    retired_and_set->retire(end_of_gc, retain);
+    retired_and_set->set_buf(buf);
+    retired_and_set->set_word_size(word_sz);
+    adjust_priority_order();
+  }
+
+private:
+  void adjust_priority_order() {
+    G1ParGCAllocBuffer* retired_and_set = _priority_buffer[0];
+
+    int last = _priority_max - 1;
+    for (int pr = 0; pr < last; ++pr) {
+      _priority_buffer[pr] = _priority_buffer[pr + 1];
+    }
+    _priority_buffer[last] = retired_and_set;
+  }
 };
 
 class G1ParScanThreadState : public StackObj {
@@ -1791,13 +1886,11 @@
   G1SATBCardTableModRefBS* _ct_bs;
   G1RemSet* _g1_rem;
 
-  G1ParGCAllocBuffer  _surviving_alloc_buffer;
-  G1ParGCAllocBuffer  _tenured_alloc_buffer;
-  G1ParGCAllocBuffer* _alloc_buffers[GCAllocPurposeCount];
+  G1ParGCAllocBufferContainer  _surviving_alloc_buffer;
+  G1ParGCAllocBufferContainer  _tenured_alloc_buffer;
+  G1ParGCAllocBufferContainer* _alloc_buffers[GCAllocPurposeCount];
   ageTable            _age_table;
 
-  G1ParScanClosure    _scanner;
-
   size_t           _alloc_buffer_waste;
   size_t           _undo_waste;
 
@@ -1850,7 +1943,7 @@
   }
 
 public:
-  G1ParScanThreadState(G1CollectedHeap* g1h, uint queue_num, ReferenceProcessor* rp);
+  G1ParScanThreadState(G1CollectedHeap* g1h, uint queue_num);
 
   ~G1ParScanThreadState() {
     FREE_C_HEAP_ARRAY(size_t, _surviving_young_words_base, mtGC);
@@ -1859,7 +1952,7 @@
   RefToScanQueue*   refs()            { return _refs;             }
   ageTable*         age_table()       { return &_age_table;       }
 
-  G1ParGCAllocBuffer* alloc_buffer(GCAllocPurpose purpose) {
+  G1ParGCAllocBufferContainer* alloc_buffer(GCAllocPurpose purpose) {
     return _alloc_buffers[purpose];
   }
 
@@ -1889,15 +1982,13 @@
     HeapWord* obj = NULL;
     size_t gclab_word_size = _g1h->desired_plab_sz(purpose);
     if (word_sz * 100 < gclab_word_size * ParallelGCBufferWastePct) {
-      G1ParGCAllocBuffer* alloc_buf = alloc_buffer(purpose);
-      add_to_alloc_buffer_waste(alloc_buf->words_remaining());
-      alloc_buf->retire(false /* end_of_gc */, false /* retain */);
+      G1ParGCAllocBufferContainer* alloc_buf = alloc_buffer(purpose);
 
       HeapWord* buf = _g1h->par_allocate_during_gc(purpose, gclab_word_size);
       if (buf == NULL) return NULL; // Let caller handle allocation failure.
-      // Otherwise.
-      alloc_buf->set_word_size(gclab_word_size);
-      alloc_buf->set_buf(buf);
+
+      add_to_alloc_buffer_waste(alloc_buf->words_remaining_in_retired_buffer());
+      alloc_buf->update(false /* end_of_gc */, false /* retain */, buf, gclab_word_size);
 
       obj = alloc_buf->allocate(word_sz);
       assert(obj != NULL, "buffer was definitely big enough...");
@@ -1987,8 +2078,6 @@
     }
   }
 
-  oop copy_to_survivor_space(oop const obj);
-
   template <class T> void deal_with_reference(T* ref_to_scan) {
     if (has_partial_array_mask(ref_to_scan)) {
       _partial_scan_cl->do_oop_nv(ref_to_scan);
@@ -2011,7 +2100,6 @@
     }
   }
 
-public:
   void trim_queue();
 };