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1 /* |
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2 * Copyright (c) 2017, Red Hat, Inc. and/or its affiliates. |
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3 * |
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4 * This code is free software; you can redistribute it and/or modify it |
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5 * under the terms of the GNU General Public License version 2 only, as |
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6 * published by the Free Software Foundation. |
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7 * |
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8 * This code is distributed in the hope that it will be useful, but WITHOUT |
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9 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
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10 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
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11 * version 2 for more details (a copy is included in the LICENSE file that |
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12 * accompanied this code). |
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13 * |
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14 * You should have received a copy of the GNU General Public License version |
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15 * 2 along with this work; if not, write to the Free Software Foundation, |
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16 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
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17 * |
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18 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
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19 * or visit www.oracle.com if you need additional information or have any |
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20 * questions. |
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21 * |
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22 */ |
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23 |
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24 #ifndef SHARE_VM_GC_EPSILON_COLLECTEDHEAP_HPP |
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25 #define SHARE_VM_GC_EPSILON_COLLECTEDHEAP_HPP |
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26 |
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27 #include "gc/shared/collectedHeap.hpp" |
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28 #include "gc/shared/space.hpp" |
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29 #include "gc/epsilon/epsilonCollectorPolicy.hpp" |
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30 #include "gc/epsilon/epsilonMonitoringSupport.hpp" |
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31 #include "gc/epsilon/epsilonBarrierSet.hpp" |
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32 #include "gc/epsilon/epsilon_globals.hpp" |
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33 |
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34 class EpsilonCollectedHeap : public CollectedHeap { |
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35 private: |
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36 EpsilonCollectorPolicy* _policy; |
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37 EpsilonMonitoringSupport* _monitoring_support; |
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38 ContiguousSpace* _space; |
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39 VirtualSpace _virtual_space; |
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40 size_t _max_tlab_size; |
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41 size_t _last_counter_update; |
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42 public: |
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43 EpsilonCollectedHeap(EpsilonCollectorPolicy* p) : _policy(p) {}; |
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44 |
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45 virtual Name kind() const { |
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46 return CollectedHeap::EpsilonCollectedHeap; |
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47 } |
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48 |
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49 virtual const char *name() const { |
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50 return "Epsilon GC"; |
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51 } |
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52 |
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53 virtual jint initialize(); |
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54 |
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55 virtual void post_initialize() {} |
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56 |
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57 static EpsilonCollectedHeap* heap(); |
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58 |
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59 virtual size_t capacity() const { return _virtual_space.committed_size(); } |
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60 virtual size_t used() const { return _space->used(); } |
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61 virtual size_t max_capacity() const { return _virtual_space.reserved_size(); } |
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62 |
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63 virtual bool is_maximal_no_gc() const { |
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64 // No GC is going to happen, unless we are at capacity. |
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65 // At which point we will fail anyway. |
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66 return used() == capacity(); |
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67 } |
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68 |
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69 virtual bool is_in(const void *p) const { return _space->is_in(p); } |
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70 |
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71 virtual bool is_scavengable(oop obj) { |
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72 // Epsilon does not move objects, no objects are scavengable. |
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73 return false; |
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74 } |
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75 |
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76 HeapWord* allocate_work(size_t size); |
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77 virtual HeapWord* mem_allocate(size_t size, bool *gc_overhead_limit_was_exceeded); |
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78 virtual HeapWord* allocate_new_tlab(size_t size); |
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79 |
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80 // TLAB allocations |
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81 virtual bool supports_tlab_allocation() const { return UseTLAB; } |
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82 virtual size_t tlab_capacity(Thread *thr) const { return capacity(); } |
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83 virtual size_t tlab_used(Thread *thr) const { return used(); } |
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84 virtual size_t max_tlab_size() const { return _max_tlab_size; } |
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85 virtual size_t unsafe_max_tlab_alloc(Thread *thr) const; |
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86 |
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87 virtual bool can_elide_tlab_store_barriers() const { |
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88 // No store barriers for Epsilon, allow elision |
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89 return true; |
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90 } |
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91 |
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92 virtual bool can_elide_initializing_store_barrier(oop new_obj) { |
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93 // No card marks for Epsilon, can elide them all. |
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94 return true; |
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95 } |
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96 |
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97 virtual bool card_mark_must_follow_store() const { |
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98 // No card marks for Epsilon. |
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99 return false; |
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100 } |
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101 |
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102 virtual void collect(GCCause::Cause cause); |
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103 virtual void do_full_collection(bool clear_all_soft_refs); |
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104 |
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105 virtual AdaptiveSizePolicy *size_policy() { |
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106 // No such thing for Epsilon |
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107 return NULL; |
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108 } |
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109 |
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110 virtual CollectorPolicy *collector_policy() const { |
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111 return _policy; |
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112 } |
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113 |
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114 virtual void object_iterate(ObjectClosure *cl) { |
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115 safe_object_iterate(cl); |
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116 } |
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117 |
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118 virtual void safe_object_iterate(ObjectClosure *cl); |
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119 |
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120 virtual HeapWord* block_start(const void *addr) const { |
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121 // Epsilon does not support block parsing. |
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122 return NULL; |
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123 } |
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124 |
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125 virtual size_t block_size(const HeapWord *addr) const { |
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126 // Epsilon does not support block parsing. |
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127 return 0; |
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128 } |
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129 |
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130 virtual bool block_is_obj(const HeapWord *addr) const { |
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131 // Epsilon does not support block parsing. |
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132 return false; |
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133 } |
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134 |
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135 virtual jlong millis_since_last_gc() { |
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136 // Report time since the VM start |
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137 return os::elapsed_counter() / NANOSECS_PER_MILLISEC; |
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138 } |
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139 |
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140 virtual void prepare_for_verify() { |
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141 // No heap verification. |
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142 } |
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143 |
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144 virtual void print_gc_threads_on(outputStream *st) const { |
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145 // No GC threads. |
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146 } |
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147 |
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148 virtual void gc_threads_do(ThreadClosure *tc) const { |
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149 // No GC threads. |
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150 } |
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151 |
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152 virtual void print_on(outputStream *st) const; |
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153 virtual void print_tracing_info() const; |
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154 |
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155 virtual void verify(VerifyOption option) { |
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156 // No heap verification for Epsilon. |
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157 } |
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158 |
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159 }; |
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160 |
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161 #endif // SHARE_VM_GC_EPSILON_COLLECTEDHEAP_HPP |