1 /* 2 * Copyright (c) 2017, 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/shared/collectedHeap.hpp" 30 #include "gc/shared/gcCause.hpp" 31 #include "gc/shared/genCollectedHeap.hpp" 32 33 class CLDClosure; 34 class GenCollectorPolicy; 35 class OopsInGenClosure; 36 class outputStream; 37 class StrongRootsScope; 38 class ThreadClosure; 39 class WorkGang; 40 41 class CMSHeap : public GenCollectedHeap { 42 public: 43 CMSHeap(GenCollectorPolicy *policy); 44 45 // Returns JNI_OK on success 46 virtual jint initialize(); 47 48 virtual void check_gen_kinds(); 49 50 // Convenience function to be used in situations where the heap type can be 51 // asserted to be this type. 52 static CMSHeap* heap(); 53 54 virtual Name kind() const { 55 return CollectedHeap::CMSHeap; 56 } 57 58 virtual const char* name() const { 59 return "Concurrent Mark Sweep"; 60 } 61 62 WorkGang* workers() const { return _workers; } 63 64 virtual void print_gc_threads_on(outputStream* st) const; 65 virtual void gc_threads_do(ThreadClosure* tc) const; 66 virtual void print_on_error(outputStream* st) const; 67 68 // Perform a full collection of the heap; intended for use in implementing 69 // "System.gc". This implies as full a collection as the CollectedHeap 70 // supports. Caller does not hold the Heap_lock on entry. 71 void collect(GCCause::Cause cause); 72 73 bool is_in_closed_subset(const void* p) const { 74 return is_in_reserved(p); 75 } 76 77 bool card_mark_must_follow_store() const { 78 return true; 79 } 80 81 void stop(); 82 void safepoint_synchronize_begin(); 83 void safepoint_synchronize_end(); 84 85 // If "young_gen_as_roots" is false, younger generations are 86 // not scanned as roots; in this case, the caller must be arranging to 87 // scan the younger generations itself. (For example, a generation might 88 // explicitly mark reachable objects in younger generations, to avoid 89 // excess storage retention.) 90 void cms_process_roots(StrongRootsScope* scope, 91 bool young_gen_as_roots, 92 ScanningOption so, 93 bool only_strong_roots, 94 OopsInGenClosure* root_closure, 95 CLDClosure* cld_closure); 96 97 private: 98 WorkGang* _workers; 99 100 virtual void gc_prologue(bool full); 101 virtual void gc_epilogue(bool full); 102 103 // Accessor for memory state verification support 104 NOT_PRODUCT( 105 virtual size_t skip_header_HeapWords() { return CMSCollector::skip_header_HeapWords(); } 106 ) 107 108 // Returns success or failure. 109 void create_cms_collector(); 110 111 // In support of ExplicitGCInvokesConcurrent functionality 112 bool should_do_concurrent_full_gc(GCCause::Cause cause); 113 114 void collect_mostly_concurrent(GCCause::Cause cause); 115 }; 116 117 #endif // SHARE_VM_GC_CMS_CMSHEAP_HPP