1 /* 2 * Copyright (c) 2017, 2018, Red Hat, Inc. 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_EPSILON_COLLECTEDHEAP_HPP 26 #define SHARE_VM_GC_EPSILON_COLLECTEDHEAP_HPP 27 28 #include "gc/shared/collectedHeap.hpp" 29 #include "gc/shared/softRefPolicy.hpp" 30 #include "gc/shared/space.hpp" 31 #include "services/memoryManager.hpp" 32 #include "gc/epsilon/epsilonCollectorPolicy.hpp" 33 #include "gc/epsilon/epsilonMonitoringSupport.hpp" 34 #include "gc/epsilon/epsilonBarrierSet.hpp" 35 #include "gc/epsilon/epsilon_globals.hpp" 36 37 class EpsilonHeap : public CollectedHeap { 38 friend class VMStructs; 39 private: 40 EpsilonCollectorPolicy* _policy; 41 SoftRefPolicy _soft_ref_policy; 42 EpsilonMonitoringSupport* _monitoring_support; 43 MemoryPool* _pool; 44 GCMemoryManager _memory_manager; 45 ContiguousSpace* _space; 46 VirtualSpace _virtual_space; 47 size_t _max_tlab_size; 48 size_t _step_counter_update; 49 size_t _step_heap_print; 50 int64_t _decay_time_ns; 51 volatile size_t _last_counter_update; 52 volatile size_t _last_heap_print; 53 54 public: 55 static EpsilonHeap* heap(); 56 EpsilonHeap(EpsilonCollectorPolicy * p)57 EpsilonHeap(EpsilonCollectorPolicy* p) : 58 _policy(p), 59 _memory_manager("Epsilon Heap", "") {}; 60 kind() const61 virtual Name kind() const { 62 return CollectedHeap::Epsilon; 63 } 64 name() const65 virtual const char* name() const { 66 return "Epsilon"; 67 } 68 collector_policy() const69 virtual CollectorPolicy* collector_policy() const { 70 return _policy; 71 } 72 soft_ref_policy()73 virtual SoftRefPolicy* soft_ref_policy() { 74 return &_soft_ref_policy; 75 } 76 77 virtual jint initialize(); 78 virtual void post_initialize(); 79 virtual void initialize_serviceability(); 80 81 virtual GrowableArray<GCMemoryManager*> memory_managers(); 82 virtual GrowableArray<MemoryPool*> memory_pools(); 83 max_capacity() const84 virtual size_t max_capacity() const { return _virtual_space.reserved_size(); } capacity() const85 virtual size_t capacity() const { return _virtual_space.committed_size(); } used() const86 virtual size_t used() const { return _space->used(); } 87 is_in(const void * p) const88 virtual bool is_in(const void* p) const { 89 return _space->is_in(p); 90 } 91 is_scavengable(oop obj)92 virtual bool is_scavengable(oop obj) { 93 // No GC is going to happen, therefore no objects ever move. 94 return false; 95 } 96 is_maximal_no_gc() const97 virtual bool is_maximal_no_gc() const { 98 // No GC is going to happen. Return "we are at max", when we are about to fail. 99 return used() == capacity(); 100 } 101 102 // Allocation 103 HeapWord* allocate_work(size_t size); 104 virtual HeapWord* mem_allocate(size_t size, bool* gc_overhead_limit_was_exceeded); 105 virtual HeapWord* allocate_new_tlab(size_t min_size, 106 size_t requested_size, 107 size_t* actual_size); 108 109 // TLAB allocation supports_tlab_allocation() const110 virtual bool supports_tlab_allocation() const { return true; } tlab_capacity(Thread * thr) const111 virtual size_t tlab_capacity(Thread* thr) const { return capacity(); } tlab_used(Thread * thr) const112 virtual size_t tlab_used(Thread* thr) const { return used(); } max_tlab_size() const113 virtual size_t max_tlab_size() const { return _max_tlab_size; } 114 virtual size_t unsafe_max_tlab_alloc(Thread* thr) const; 115 116 virtual void collect(GCCause::Cause cause); 117 virtual void do_full_collection(bool clear_all_soft_refs); 118 119 // Heap walking support 120 virtual void safe_object_iterate(ObjectClosure* cl); object_iterate(ObjectClosure * cl)121 virtual void object_iterate(ObjectClosure* cl) { 122 safe_object_iterate(cl); 123 } 124 125 // Object pinning support: every object is implicitly pinned supports_object_pinning() const126 virtual bool supports_object_pinning() const { return true; } pin_object(JavaThread * thread,oop obj)127 virtual oop pin_object(JavaThread* thread, oop obj) { return obj; } unpin_object(JavaThread * thread,oop obj)128 virtual void unpin_object(JavaThread* thread, oop obj) { } 129 130 // No support for block parsing. block_start(const void * addr) const131 virtual HeapWord* block_start(const void* addr) const { return NULL; } block_size(const HeapWord * addr) const132 virtual size_t block_size(const HeapWord* addr) const { return 0; } block_is_obj(const HeapWord * addr) const133 virtual bool block_is_obj(const HeapWord* addr) const { return false; } 134 135 // No GC threads print_gc_threads_on(outputStream * st) const136 virtual void print_gc_threads_on(outputStream* st) const {} gc_threads_do(ThreadClosure * tc) const137 virtual void gc_threads_do(ThreadClosure* tc) const {} 138 139 // No heap verification prepare_for_verify()140 virtual void prepare_for_verify() {} verify(VerifyOption option)141 virtual void verify(VerifyOption option) {} 142 millis_since_last_gc()143 virtual jlong millis_since_last_gc() { 144 // Report time since the VM start 145 return os::elapsed_counter() / NANOSECS_PER_MILLISEC; 146 } 147 148 virtual void print_on(outputStream* st) const; 149 virtual void print_tracing_info() const; 150 151 private: 152 void print_heap_info(size_t used) const; 153 void print_metaspace_info() const; 154 155 }; 156 157 #endif // SHARE_VM_GC_EPSILON_COLLECTEDHEAP_HPP 158