1 /* 2 * Copyright (c) 2001, 2015, 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 6 * under the terms of the GNU General Public License version 2 only, as 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. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 * 23 */ 24 25 #ifndef SHARE_VM_MEMORY_TENUREDGENERATION_HPP 26 #define SHARE_VM_MEMORY_TENUREDGENERATION_HPP 27 28 #include "gc_implementation/shared/cSpaceCounters.hpp" 29 #include "gc_implementation/shared/gcStats.hpp" 30 #include "gc_implementation/shared/generationCounters.hpp" 31 #include "memory/cardGeneration.hpp" 32 #include "utilities/macros.hpp" 33 34 // TenuredGeneration models the heap containing old (promoted/tenured) objects 35 // contained in a single contiguous space. 36 // 37 // Garbage collection is performed using mark-compact. 38 39 class TenuredGeneration: public CardGeneration { 40 friend class VMStructs; 41 // Abstractly, this is a subtype that gets access to protected fields. 42 friend class VM_PopulateDumpSharedSpace; 43 44 protected: 45 ContiguousSpace* _the_space; // Actual space holding objects 46 47 GenerationCounters* _gen_counters; 48 CSpaceCounters* _space_counters; 49 50 // Allocation failure 51 virtual bool expand(size_t bytes, size_t expand_bytes); 52 53 // Accessing spaces 54 ContiguousSpace* space() const { return _the_space; } 55 56 void assert_correct_size_change_locking(); 57 public: 58 TenuredGeneration(ReservedSpace rs, 59 size_t initial_byte_size, 60 GenRemSet* remset); 61 62 Generation::Name kind() { return Generation::MarkSweepCompact; } 63 64 // Printing 65 const char* name() const { return "tenured generation"; } 66 const char* short_name() const { return "Tenured"; } 67 68 // Does a "full" (forced) collection invoked on this generation collect 69 // all younger generations as well? Note that this is a 70 // hack to allow the collection of the younger gen first if the flag is 71 // set. 72 virtual bool full_collects_younger_generations() const { 73 return !ScavengeBeforeFullGC; 74 } 75 76 size_t unsafe_max_alloc_nogc() const; 77 size_t contiguous_available() const; 78 79 // Iteration 80 void object_iterate(ObjectClosure* blk); 81 82 virtual inline HeapWord* allocate(size_t word_size, bool is_tlab); 83 virtual inline HeapWord* par_allocate(size_t word_size, bool is_tlab); 84 85 #define TenuredGen_SINCE_SAVE_MARKS_DECL(OopClosureType, nv_suffix) \ 86 void oop_since_save_marks_iterate##nv_suffix(OopClosureType* cl); 87 TenuredGen_SINCE_SAVE_MARKS_DECL(OopsInGenClosure,_v) 88 SPECIALIZED_SINCE_SAVE_MARKS_CLOSURES(TenuredGen_SINCE_SAVE_MARKS_DECL) 89 90 void save_marks(); 91 void reset_saved_marks(); 92 bool no_allocs_since_save_marks(); 93 94 inline size_t block_size(const HeapWord* addr) const; 95 96 inline bool block_is_obj(const HeapWord* addr) const; 97 98 virtual void collect(bool full, 99 bool clear_all_soft_refs, 100 size_t size, 101 bool is_tlab); 102 HeapWord* expand_and_allocate(size_t size, 103 bool is_tlab, 104 bool parallel = false); 105 106 virtual void prepare_for_verify(); 107 108 109 virtual void gc_prologue(bool full); 110 virtual void gc_epilogue(bool full); 111 bool should_collect(bool full, 112 size_t word_size, 113 bool is_tlab); 114 115 virtual void compute_new_size(); 116 117 // Performance Counter support 118 void update_counters(); 119 120 virtual void record_spaces_top(); 121 122 // Statistics 123 124 virtual void update_gc_stats(Generation* current_generation, bool full); 125 126 virtual bool promotion_attempt_is_safe(size_t max_promoted_in_bytes) const; 127 128 virtual void verify(); 129 virtual void print_on(outputStream* st) const; 130 }; 131 132 #endif // SHARE_VM_MEMORY_TENUREDGENERATION_HPP