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/shared/collectedHeap.hpp" 29 #include "gc/shared/gcCause.hpp" 30 #include "gc/shared/genCollectedHeap.hpp" 31 32 class CLDClosure; 33 class GenCollectorPolicy; 34 class OopsInGenClosure; 35 class outputStream; 36 class StrongRootsScope; 37 class ThreadClosure; 38 class WorkGang; 39 40 class CMSHeap : public GenCollectedHeap { 41 public: 42 CMSHeap(GenCollectorPolicy *policy); 43 44 // Returns JNI_OK on success 45 virtual jint initialize(); 46 47 virtual void check_gen_kinds(); 48 49 // Convenience function to be used in situations where the heap type can be 50 // asserted to be this type. 51 static CMSHeap* heap(); 52 53 virtual Name kind() const { 54 return CollectedHeap::CMSHeap; 55 } 56 57 virtual const char* name() const { 58 return "Concurrent Mark Sweep"; 59 } 60 61 WorkGang* workers() const { return _workers; } 62 63 virtual void print_gc_threads_on(outputStream* st) const; 64 virtual void gc_threads_do(ThreadClosure* tc) const; 65 virtual void print_on_error(outputStream* st) const; 66 67 // Perform a full collection of the heap; intended for use in implementing 68 // "System.gc". This implies as full a collection as the CollectedHeap 69 // supports. Caller does not hold the Heap_lock on entry. 70 void collect(GCCause::Cause cause); 71 72 bool is_in_closed_subset(const void* p) const { 73 return is_in_reserved(p); 74 } 75 76 bool card_mark_must_follow_store() const { 77 return true; 78 } 79 80 void stop(); 81 82 // If "young_gen_as_roots" is false, younger generations are 83 // not scanned as roots; in this case, the caller must be arranging to 84 // scan the younger generations itself. (For example, a generation might 85 // explicitly mark reachable objects in younger generations, to avoid 86 // excess storage retention.) 87 void cms_process_roots(StrongRootsScope* scope, 88 bool young_gen_as_roots, 89 ScanningOption so, 90 bool only_strong_roots, 91 OopsInGenClosure* root_closure, 92 CLDClosure* cld_closure); 93 94 private: 95 WorkGang* _workers; 96 97 virtual void gc_prologue(bool full); 98 virtual void gc_epilogue(bool full); 99 100 // Accessor for memory state verification support 101 NOT_PRODUCT( 102 virtual size_t skip_header_HeapWords() { return CMSCollector::skip_header_HeapWords(); } 103 ) 104 105 // Returns success or failure. 106 void create_cms_collector(); 107 108 // In support of ExplicitGCInvokesConcurrent functionality 109 bool should_do_concurrent_full_gc(GCCause::Cause cause); 110 111 void collect_mostly_concurrent(GCCause::Cause cause); 112 }; 113 114 #endif // SHARE_VM_GC_CMS_CMSHEAP_HPP