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 43 protected: 44 virtual void check_gen_kinds(); 45 46 public: 47 CMSHeap(GenCollectorPolicy *policy); 48 49 // Returns JNI_OK on success 50 virtual jint initialize(); 51 52 // Convenience function to be used in situations where the heap type can be 53 // asserted to be this type. 54 static CMSHeap* heap(); 55 56 virtual Name kind() const { 57 return CollectedHeap::CMSHeap; 58 } 59 60 virtual const char* name() const { 61 return "Concurrent Mark Sweep"; 62 } 63 64 WorkGang* workers() const { return _workers; } 65 66 virtual void print_gc_threads_on(outputStream* st) const; 67 virtual void gc_threads_do(ThreadClosure* tc) const; 68 virtual void print_on_error(outputStream* st) const; 69 70 // Perform a full collection of the heap; intended for use in implementing 71 // "System.gc". This implies as full a collection as the CollectedHeap 72 // supports. Caller does not hold the Heap_lock on entry. 73 void collect(GCCause::Cause cause); 74 75 bool card_mark_must_follow_store() const { 76 return true; 77 } 78 79 void stop(); 80 void safepoint_synchronize_begin(); 81 void safepoint_synchronize_end(); 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 private: 96 WorkGang* _workers; 97 98 virtual void gc_prologue(bool full); 99 virtual void gc_epilogue(bool full); 100 101 // Accessor for memory state verification support 102 NOT_PRODUCT( 103 virtual size_t skip_header_HeapWords() { return CMSCollector::skip_header_HeapWords(); } 104 ) 105 106 // Returns success or failure. 107 bool create_cms_collector(); 108 109 // In support of ExplicitGCInvokesConcurrent functionality 110 bool should_do_concurrent_full_gc(GCCause::Cause cause); 111 112 void collect_mostly_concurrent(GCCause::Cause cause); 113 }; 114 115 #endif // SHARE_VM_GC_CMS_CMSHEAP_HPP