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