1 /* 2 * Copyright (c) 2017, 2018, Red Hat, Inc. All rights reserved. 3 * 4 * This code is free software; you can redistribute it and/or modify it 5 * under the terms of the GNU General Public License version 2 only, as 6 * published by the Free Software Foundation. 7 * 8 * This code is distributed in the hope that it will be useful, but WITHOUT 9 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 10 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 11 * version 2 for more details (a copy is included in the LICENSE file that 12 * accompanied this code). 13 * 14 * You should have received a copy of the GNU General Public License version 15 * 2 along with this work; if not, write to the Free Software Foundation, 16 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 17 * 18 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 19 * or visit www.oracle.com if you need additional information or have any 20 * questions. 21 * 22 */ 23 24 #ifndef SHARE_VM_GC_EPSILON_COLLECTEDHEAP_HPP 25 #define SHARE_VM_GC_EPSILON_COLLECTEDHEAP_HPP 26 27 #include "gc/shared/collectedHeap.hpp" 28 #include "gc/shared/softRefPolicy.hpp" 29 #include "gc/shared/space.hpp" 30 #include "services/memoryManager.hpp" 31 #include "gc/epsilon/epsilonCollectorPolicy.hpp" 32 #include "gc/epsilon/epsilonMonitoringSupport.hpp" 33 #include "gc/epsilon/epsilonBarrierSet.hpp" 34 #include "gc/epsilon/epsilon_globals.hpp" 35 36 class EpsilonHeap : public CollectedHeap { 37 private: 38 EpsilonCollectorPolicy* _policy; 39 SoftRefPolicy _soft_ref_policy; 40 EpsilonMonitoringSupport* _monitoring_support; 41 MemoryPool* _pool; 42 GCMemoryManager _memory_manager; 43 ContiguousSpace* _space; 44 VirtualSpace _virtual_space; 45 size_t _max_tlab_size; 46 size_t _last_counter_update; 47 size_t _last_heap_print; 48 size_t _step_counter_update; 49 size_t _step_heap_print; 50 51 public: 52 static EpsilonHeap* heap(); 53 54 EpsilonHeap(EpsilonCollectorPolicy* p) : 55 _policy(p), 56 _memory_manager("Epsilon Heap", "") {}; 57 58 virtual Name kind() const { 59 return CollectedHeap::Epsilon; 60 } 61 62 virtual const char* name() const { 63 return "Epsilon"; 64 } 65 66 virtual CollectorPolicy* collector_policy() const { 67 return _policy; 68 } 69 70 virtual SoftRefPolicy* soft_ref_policy() { 71 return &_soft_ref_policy; 72 } 73 74 virtual jint initialize(); 75 virtual void post_initialize(); 76 virtual void initialize_serviceability(); 77 78 virtual GrowableArray<GCMemoryManager*> memory_managers(); 79 virtual GrowableArray<MemoryPool*> memory_pools(); 80 81 virtual size_t max_capacity() const { return _virtual_space.reserved_size(); } 82 virtual size_t capacity() const { return _virtual_space.committed_size(); } 83 virtual size_t used() const { return _space->used(); } 84 85 virtual bool is_in(const void* p) const { 86 return _space->is_in(p); 87 } 88 89 virtual bool is_scavengable(oop obj) { 90 // No GC is going to happen, therefore no objects ever move. 91 return false; 92 } 93 94 virtual bool is_maximal_no_gc() const { 95 // No GC is going to happen. Return "we are at max", when we are about to fail. 96 return used() == capacity(); 97 } 98 99 // Allocation 100 HeapWord* allocate_work(size_t size); 101 virtual HeapWord* mem_allocate(size_t size, bool* gc_overhead_limit_was_exceeded); 102 virtual HeapWord* allocate_new_tlab(size_t size); 103 104 // TLAB allocation 105 virtual bool supports_tlab_allocation() const { return UseTLAB; } 106 virtual size_t tlab_capacity(Thread* thr) const { return capacity(); } 107 virtual size_t tlab_used(Thread* thr) const { return used(); } 108 virtual size_t max_tlab_size() const { return _max_tlab_size; } 109 virtual size_t unsafe_max_tlab_alloc(Thread* thr) const; 110 111 virtual void collect(GCCause::Cause cause); 112 virtual void do_full_collection(bool clear_all_soft_refs); 113 114 // Heap walking support 115 virtual void safe_object_iterate(ObjectClosure* cl); 116 virtual void object_iterate(ObjectClosure* cl) { 117 safe_object_iterate(cl); 118 } 119 120 // No support for block parsing. 121 virtual HeapWord* block_start(const void* addr) const { return NULL; } 122 virtual size_t block_size(const HeapWord* addr) const { return 0; } 123 virtual bool block_is_obj(const HeapWord* addr) const { return false; } 124 125 // No GC threads 126 virtual void print_gc_threads_on(outputStream* st) const {} 127 virtual void gc_threads_do(ThreadClosure* tc) const {} 128 129 // No heap verification 130 virtual void prepare_for_verify() {} 131 virtual void verify(VerifyOption option) {} 132 133 virtual jlong millis_since_last_gc() { 134 // Report time since the VM start 135 return os::elapsed_counter() / NANOSECS_PER_MILLISEC; 136 } 137 138 virtual void print_on(outputStream* st) const; 139 virtual void print_tracing_info() const; 140 141 }; 142 143 #endif // SHARE_VM_GC_EPSILON_COLLECTEDHEAP_HPP