Fri, 18 Feb 2011 10:07:34 -0800
7020042: G1: Partially remove fix for 6994628
Summary: Disable reference discovery and processing during concurrent marking by disabling fix for 6994628.
Reviewed-by: tonyp, ysr
1 /*
2 * Copyright (c) 2001, 2011, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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5 * This code is free software; you can redistribute it and/or modify it
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7 * published by the Free Software Foundation.
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10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
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23 */
25 #ifndef SHARE_VM_GC_IMPLEMENTATION_G1_HEAPREGIONSEQ_HPP
26 #define SHARE_VM_GC_IMPLEMENTATION_G1_HEAPREGIONSEQ_HPP
28 #include "gc_implementation/g1/heapRegion.hpp"
29 #include "utilities/growableArray.hpp"
31 class HeapRegion;
32 class HeapRegionClosure;
34 class HeapRegionSeq: public CHeapObj {
36 // _regions is kept sorted by start address order, and no two regions are
37 // overlapping.
38 GrowableArray<HeapRegion*> _regions;
40 // The index in "_regions" at which to start the next allocation search.
41 // (For efficiency only; private to obj_allocate after initialization.)
42 int _alloc_search_start;
44 // Finds a contiguous set of empty regions of length num, starting
45 // from a given index.
46 int find_contiguous_from(int from, size_t num);
48 // Currently, we're choosing collection sets in a round-robin fashion,
49 // starting here.
50 int _next_rr_candidate;
52 // The bottom address of the bottom-most region, or else NULL if there
53 // are no regions in the sequence.
54 char* _seq_bottom;
56 public:
57 // Initializes "this" to the empty sequence of regions.
58 HeapRegionSeq(const size_t max_size);
60 // Adds "hr" to "this" sequence. Requires "hr" not to overlap with
61 // any region already in "this". (Will perform better if regions are
62 // inserted in ascending address order.)
63 void insert(HeapRegion* hr);
65 // Given a HeapRegion*, returns its index within _regions,
66 // or returns -1 if not found.
67 int find(HeapRegion* hr);
69 // Requires the index to be valid, and return the region at the index.
70 HeapRegion* at(size_t i) { return _regions.at((int)i); }
72 // Return the number of regions in the sequence.
73 size_t length();
75 // Returns the number of contiguous regions at the end of the sequence
76 // that are available for allocation.
77 size_t free_suffix();
79 // Find a contiguous set of empty regions of length num and return
80 // the index of the first region or -1 if the search was unsuccessful.
81 int find_contiguous(size_t num);
83 // Apply the "doHeapRegion" method of "blk" to all regions in "this",
84 // in address order, terminating the iteration early
85 // if the "doHeapRegion" method returns "true".
86 void iterate(HeapRegionClosure* blk);
88 // Apply the "doHeapRegion" method of "blk" to all regions in "this",
89 // starting at "r" (or first region, if "r" is NULL), in a circular
90 // manner, terminating the iteration early if the "doHeapRegion" method
91 // returns "true".
92 void iterate_from(HeapRegion* r, HeapRegionClosure* blk);
94 // As above, but start from a given index in the sequence
95 // instead of a given heap region.
96 void iterate_from(int idx, HeapRegionClosure* blk);
98 // Requires "shrink_bytes" to be a multiple of the page size and heap
99 // region granularity. Deletes as many "rightmost" completely free heap
100 // regions from the sequence as comprise shrink_bytes bytes. Returns the
101 // MemRegion indicating the region those regions comprised, and sets
102 // "num_regions_deleted" to the number of regions deleted.
103 MemRegion shrink_by(size_t shrink_bytes, size_t& num_regions_deleted);
105 // If "addr" falls within a region in the sequence, return that region,
106 // or else NULL.
107 inline HeapRegion* addr_to_region(const void* addr);
109 void print();
111 // Prints out runs of empty regions.
112 void print_empty_runs();
114 };
116 #endif // SHARE_VM_GC_IMPLEMENTATION_G1_HEAPREGIONSEQ_HPP