1 /* 2 * Copyright (c) 2017, 2018, 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_GC_CMS_CMSHEAP_HPP 26 #define SHARE_VM_GC_CMS_CMSHEAP_HPP 27 28 #include "gc/cms/concurrentMarkSweepGeneration.hpp" 29 #include "gc/cms/parNewGeneration.hpp" 30 #include "gc/shared/collectedHeap.hpp" 31 #include "gc/shared/gcCause.hpp" 32 #include "gc/shared/genCollectedHeap.hpp" 33 #include "utilities/growableArray.hpp" 34 35 class CLDClosure; 36 class GenCollectorPolicy; 37 class GCMemoryManager; 38 class MemoryPool; 39 class OopsInGenClosure; 40 class outputStream; 41 class StrongRootsScope; 42 class ThreadClosure; 43 class WorkGang; 44 45 class CMSHeap : public GenCollectedHeap { 46 public: 47 CMSHeap(GenCollectorPolicy *policy); 48 49 // Returns JNI_OK on success 50 virtual jint initialize(); 51 virtual CardTableRS* create_rem_set(const MemRegion& reserved_region); 52 53 // Convenience function to be used in situations where the heap type can be 54 // asserted to be this type. 55 static CMSHeap* heap(); 56 57 virtual Name kind() const { 58 return CollectedHeap::CMS; 59 } 60 61 virtual const char* name() const { 62 return "Concurrent Mark Sweep"; 63 } 64 65 WorkGang* workers() const { return _workers; } 66 67 virtual void print_gc_threads_on(outputStream* st) const; 68 virtual void gc_threads_do(ThreadClosure* tc) const; 69 virtual void print_on_error(outputStream* st) const; 70 71 // Perform a full collection of the heap; intended for use in implementing 72 // "System.gc". This implies as full a collection as the CollectedHeap 73 // supports. Caller does not hold the Heap_lock on entry. 74 void collect(GCCause::Cause cause); 75 76 void stop(); 77 void safepoint_synchronize_begin(); 78 void safepoint_synchronize_end(); 79 80 virtual GrowableArray<GCMemoryManager*> memory_managers(); 81 virtual GrowableArray<MemoryPool*> memory_pools(); 82 83 // If "young_gen_as_roots" is false, younger generations are 84 // not scanned as roots; in this case, the caller must be arranging to 85 // scan the younger generations itself. (For example, a generation might 86 // explicitly mark reachable objects in younger generations, to avoid 87 // excess storage retention.) 88 void cms_process_roots(StrongRootsScope* scope, 89 bool young_gen_as_roots, 90 ScanningOption so, 91 bool only_strong_roots, 92 OopsInGenClosure* root_closure, 93 CLDClosure* cld_closure); 94 95 GCMemoryManager* old_manager() const { return _old_manager; } 96 97 ParNewGeneration* young_gen() const { 98 assert(_young_gen->kind() == Generation::ParNew, "Wrong generation type"); 99 return static_cast<ParNewGeneration*>(_young_gen); 100 } 101 102 ConcurrentMarkSweepGeneration* old_gen() const { 103 assert(_old_gen->kind() == Generation::ConcurrentMarkSweep, "Wrong generation kind"); 104 return static_cast<ConcurrentMarkSweepGeneration*>(_old_gen); 105 } 106 107 // Apply "cur->do_oop" or "older->do_oop" to all the oops in objects 108 // allocated since the last call to save_marks in the young generation. 109 // The "cur" closure is applied to references in the younger generation 110 // at "level", and the "older" closure to older generations. 111 template <typename OopClosureType1, typename OopClosureType2> 112 void oop_since_save_marks_iterate(OopClosureType1* cur, 113 OopClosureType2* older); 114 115 private: 116 WorkGang* _workers; 117 MemoryPool* _eden_pool; 118 MemoryPool* _survivor_pool; 119 MemoryPool* _old_pool; 120 121 virtual void gc_prologue(bool full); 122 virtual void gc_epilogue(bool full); 123 124 virtual void initialize_serviceability(); 125 126 // Accessor for memory state verification support 127 NOT_PRODUCT( 128 virtual size_t skip_header_HeapWords() { return CMSCollector::skip_header_HeapWords(); } 129 ) 130 131 // Returns success or failure. 132 bool create_cms_collector(); 133 134 // In support of ExplicitGCInvokesConcurrent functionality 135 bool should_do_concurrent_full_gc(GCCause::Cause cause); 136 137 void collect_mostly_concurrent(GCCause::Cause cause); 138 }; 139 140 #endif // SHARE_VM_GC_CMS_CMSHEAP_HPP