Thu, 13 Jun 2013 22:02:40 -0700
8014431: cleanup warnings indicated by the -Wunused-value compiler option on linux
Reviewed-by: dholmes, coleenp
Contributed-by: jeremymanson@google.com, calvin.cheung@oracle.com
1 /*
2 * Copyright (c) 2001, 2010, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
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.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
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,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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23 */
25 #ifndef SHARE_VM_MEMORY_TENUREDGENERATION_HPP
26 #define SHARE_VM_MEMORY_TENUREDGENERATION_HPP
28 #include "gc_implementation/shared/cSpaceCounters.hpp"
29 #include "gc_implementation/shared/gcStats.hpp"
30 #include "gc_implementation/shared/generationCounters.hpp"
31 #include "memory/generation.hpp"
32 #include "utilities/macros.hpp"
34 // TenuredGeneration models the heap containing old (promoted/tenured) objects.
36 class ParGCAllocBufferWithBOT;
38 class TenuredGeneration: public OneContigSpaceCardGeneration {
39 friend class VMStructs;
40 protected:
42 #if INCLUDE_ALL_GCS
43 // To support parallel promotion: an array of parallel allocation
44 // buffers, one per thread, initially NULL.
45 ParGCAllocBufferWithBOT** _alloc_buffers;
46 #endif // INCLUDE_ALL_GCS
48 // Retire all alloc buffers before a full GC, so that they will be
49 // re-allocated at the start of the next young GC.
50 void retire_alloc_buffers_before_full_gc();
52 GenerationCounters* _gen_counters;
53 CSpaceCounters* _space_counters;
55 public:
56 TenuredGeneration(ReservedSpace rs, size_t initial_byte_size, int level,
57 GenRemSet* remset);
59 Generation::Name kind() { return Generation::MarkSweepCompact; }
61 // Printing
62 const char* name() const;
63 const char* short_name() const { return "Tenured"; }
64 bool must_be_youngest() const { return false; }
65 bool must_be_oldest() const { return true; }
67 // Does a "full" (forced) collection invoked on this generation collect
68 // all younger generations as well? Note that this is a
69 // hack to allow the collection of the younger gen first if the flag is
70 // set. This is better than using th policy's should_collect_gen0_first()
71 // since that causes us to do an extra unnecessary pair of restart-&-stop-world.
72 virtual bool full_collects_younger_generations() const {
73 return !CollectGen0First;
74 }
76 virtual void gc_prologue(bool full);
77 virtual void gc_epilogue(bool full);
78 bool should_collect(bool full,
79 size_t word_size,
80 bool is_tlab);
82 virtual void collect(bool full,
83 bool clear_all_soft_refs,
84 size_t size,
85 bool is_tlab);
86 virtual void compute_new_size();
88 #if INCLUDE_ALL_GCS
89 // Overrides.
90 virtual oop par_promote(int thread_num,
91 oop obj, markOop m, size_t word_sz);
92 virtual void par_promote_alloc_undo(int thread_num,
93 HeapWord* obj, size_t word_sz);
94 virtual void par_promote_alloc_done(int thread_num);
95 #endif // INCLUDE_ALL_GCS
97 // Performance Counter support
98 void update_counters();
100 // Statistics
102 virtual void update_gc_stats(int level, bool full);
104 virtual bool promotion_attempt_is_safe(size_t max_promoted_in_bytes) const;
106 void verify_alloc_buffers_clean();
107 };
109 #endif // SHARE_VM_MEMORY_TENUREDGENERATION_HPP