1.1 --- a/src/share/vm/gc_implementation/g1/heapRegionSet.hpp Mon Mar 24 09:14:14 2014 -0700
1.2 +++ b/src/share/vm/gc_implementation/g1/heapRegionSet.hpp Fri Feb 28 15:27:09 2014 +0100
1.3 @@ -1,5 +1,5 @@
1.4 /*
1.5 - * Copyright (c) 2011, 2012, Oracle and/or its affiliates. All rights reserved.
1.6 + * Copyright (c) 2011, 2014, Oracle and/or its affiliates. All rights reserved.
1.7 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
1.8 *
1.9 * This code is free software; you can redistribute it and/or modify it
1.10 @@ -191,11 +191,14 @@
1.11 }
1.12 };
1.13
1.14 -// A set that links all the regions added to it in a singly-linked
1.15 +// A set that links all the regions added to it in a doubly-linked
1.16 // list. We should try to avoid doing operations that iterate over
1.17 // such lists in performance critical paths. Typically we should
1.18 -// add / remove one region at a time or concatenate two lists. All
1.19 -// those operations are done in constant time.
1.20 +// add / remove one region at a time or concatenate two lists. There are
1.21 +// two ways to treat your lists, ordered and un-ordered. All un-ordered
1.22 +// operations are done in constant time. To keep a list ordered only use
1.23 +// add_ordered() to add elements to the list. If a list is not ordered
1.24 +// from start, there is no way to sort it later.
1.25
1.26 class FreeRegionListIterator;
1.27
1.28 @@ -206,6 +209,11 @@
1.29 HeapRegion* _head;
1.30 HeapRegion* _tail;
1.31
1.32 + // _last is used to keep track of where we added an element the last
1.33 + // time in ordered lists. It helps to improve performance when adding
1.34 + // several ordered items in a row.
1.35 + HeapRegion* _last;
1.36 +
1.37 static uint _unrealistically_long_length;
1.38
1.39 void add_as_head_or_tail(FreeRegionList* from_list, bool as_head);
1.40 @@ -229,6 +237,11 @@
1.41
1.42 static void set_unrealistically_long_length(uint len);
1.43
1.44 + // Add hr to the list. The region should not be a member of another set.
1.45 + // Assumes that the list is ordered and will preserve that order. The order
1.46 + // is determined by hrs_index.
1.47 + inline void add_ordered(HeapRegion* hr);
1.48 +
1.49 // It adds hr to the list as the new head. The region should not be
1.50 // a member of another set.
1.51 inline void add_as_head(HeapRegion* hr);
1.52 @@ -244,6 +257,20 @@
1.53 // Convenience method.
1.54 inline HeapRegion* remove_head_or_null();
1.55
1.56 + // Removes and returns the last element (_tail) of the list. It assumes
1.57 + // that the list isn't empty so that it can return a non-NULL value.
1.58 + inline HeapRegion* remove_tail();
1.59 +
1.60 + // Convenience method
1.61 + inline HeapRegion* remove_tail_or_null();
1.62 +
1.63 + // Removes from head or tail based on the given argument.
1.64 + inline HeapRegion* remove_region(bool from_head);
1.65 +
1.66 + // Merge two ordered lists. The result is also ordered. The order is
1.67 + // determined by hrs_index.
1.68 + void add_ordered(FreeRegionList* from_list);
1.69 +
1.70 // It moves the regions from from_list to this list and empties
1.71 // from_list. The new regions will appear in the same order as they
1.72 // were in from_list and be linked in the beginning of this list.
1.73 @@ -276,7 +303,7 @@
1.74 class FreeRegionListIterator : public StackObj {
1.75 private:
1.76 FreeRegionList* _list;
1.77 - HeapRegion* _curr;
1.78 + HeapRegion* _curr;
1.79
1.80 public:
1.81 bool more_available() {
1.82 @@ -296,8 +323,7 @@
1.83 return hr;
1.84 }
1.85
1.86 - FreeRegionListIterator(FreeRegionList* list)
1.87 - : _curr(NULL), _list(list) {
1.88 + FreeRegionListIterator(FreeRegionList* list) : _curr(NULL), _list(list) {
1.89 _curr = list->head();
1.90 }
1.91 };
