1 /* 2 * Copyright (c) 2001, 2013, 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/generation.hpp" 32 #include "utilities/macros.hpp" 33 34 // TenuredGeneration models the heap containing old (promoted/tenured) objects. 35 36 class ParGCAllocBufferWithBOT; 37 38 class TenuredGeneration: public OneContigSpaceCardGeneration { 39 friend class VMStructs; 40 protected: 41 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 47 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(); 51 52 GenerationCounters* _gen_counters; 53 CSpaceCounters* _space_counters; 54 55 public: 56 TenuredGeneration(ReservedSpace rs, size_t initial_byte_size, int level, 57 GenRemSet* remset); 58 59 Generation::Name kind() { return Generation::MarkSweepCompact; } 60 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; } 66 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. 71 virtual bool full_collects_younger_generations() const { 72 return !ScavengeBeforeFullGC; 73 } 74 75 virtual void gc_prologue(bool full); 76 virtual void gc_epilogue(bool full); 77 bool should_collect(bool full, 78 size_t word_size, 79 bool is_tlab); 80 81 virtual void collect(bool full, 82 bool clear_all_soft_refs, 83 size_t size, 84 bool is_tlab); 85 virtual void compute_new_size(); 86 87 #if INCLUDE_ALL_GCS 88 // Overrides. 89 virtual oop par_promote(int thread_num, 90 oop obj, markOop m, size_t word_sz); 91 virtual void par_promote_alloc_undo(int thread_num, 92 HeapWord* obj, size_t word_sz); 93 virtual void par_promote_alloc_done(int thread_num); 94 #endif // INCLUDE_ALL_GCS 95 96 // Performance Counter support 97 void update_counters(); 98 99 // Statistics 100 101 virtual void update_gc_stats(int level, bool full); 102 103 virtual bool promotion_attempt_is_safe(size_t max_promoted_in_bytes) const; 104 105 void verify_alloc_buffers_clean(); 106 }; 107 108 #endif // SHARE_VM_MEMORY_TENUREDGENERATION_HPP