| File: | jdk/src/hotspot/share/gc/g1/g1SegmentedArrayFreeMemoryTask.cpp |
| Warning: | line 140, column 11 Value stored to 'next_state' is never read |
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| 1 | /* |
| 2 | * Copyright (c) 2021, 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 | #include "precompiled.hpp" |
| 26 | #include "ci/ciUtilities.hpp" |
| 27 | #include "gc/g1/g1CardSetMemory.inline.hpp" |
| 28 | #include "gc/g1/g1CollectedHeap.hpp" |
| 29 | #include "gc/g1/g1SegmentedArrayFreeMemoryTask.hpp" |
| 30 | #include "gc/g1/g1_globals.hpp" |
| 31 | #include "gc/g1/heapRegionRemSet.hpp" |
| 32 | #include "gc/shared/gcTraceTime.inline.hpp" |
| 33 | #include "gc/shared/suspendibleThreadSet.hpp" |
| 34 | #include "runtime/os.hpp" |
| 35 | |
| 36 | constexpr const char* G1SegmentedArrayFreeMemoryTask::_state_names[]; |
| 37 | |
| 38 | const char* G1SegmentedArrayFreeMemoryTask::get_state_name(State value) const { |
| 39 | return _state_names[static_cast<std::underlying_type_t<State>>(value)]; |
| 40 | } |
| 41 | |
| 42 | bool G1SegmentedArrayFreeMemoryTask::deadline_exceeded(jlong deadline) { |
| 43 | return os::elapsed_counter() >= deadline; |
| 44 | } |
| 45 | |
| 46 | static size_t keep_size(size_t free, size_t used, double percent) { |
| 47 | size_t to_keep = used * percent; |
| 48 | return MIN2(free, to_keep); |
| 49 | } |
| 50 | |
| 51 | bool G1SegmentedArrayFreeMemoryTask::calculate_return_infos(jlong deadline) { |
| 52 | // Ignore the deadline in this step as it is very short. |
| 53 | |
| 54 | G1SegmentedArrayMemoryStats used = _total_used; |
| 55 | G1SegmentedArrayMemoryStats free = G1SegmentedArrayFreePool<mtGCCardSet>::free_list_sizes(); |
| 56 | |
| 57 | _return_info = new G1ReturnMemoryProcessorSet(used.num_pools()); |
| 58 | for (uint i = 0; i < used.num_pools(); i++) { |
| 59 | size_t return_to_vm_size = keep_size(free._num_mem_sizes[i], |
| 60 | used._num_mem_sizes[i], |
| 61 | G1RemSetFreeMemoryKeepExcessRatio); |
| 62 | log_trace(gc, task)(!(LogImpl<(LogTag::_gc), (LogTag::_task), (LogTag::__NO_TAG ), (LogTag::__NO_TAG), (LogTag::__NO_TAG), (LogTag::__NO_TAG) >::is_level(LogLevel::Trace))) ? (void)0 : LogImpl<(LogTag ::_gc), (LogTag::_task), (LogTag::__NO_TAG), (LogTag::__NO_TAG ), (LogTag::__NO_TAG), (LogTag::__NO_TAG)>::write<LogLevel ::Trace>("Segmented Array Free Memory: Type %s: Free: %zu (%zu) " |
| 63 | "Used: %zu Keep: %zu", |
| 64 | G1CardSetConfiguration::mem_object_type_name_str(i), |
| 65 | free._num_mem_sizes[i], free._num_segments[i], |
| 66 | used._num_mem_sizes[i], return_to_vm_size); |
| 67 | |
| 68 | _return_info->append(new G1ReturnMemoryProcessor(return_to_vm_size)); |
| 69 | } |
| 70 | |
| 71 | G1SegmentedArrayFreePool<mtGCCardSet>::update_unlink_processors(_return_info); |
| 72 | return false; |
| 73 | } |
| 74 | |
| 75 | bool G1SegmentedArrayFreeMemoryTask::return_memory_to_vm(jlong deadline) { |
| 76 | for (int i = 0; i < _return_info->length(); i++) { |
| 77 | G1ReturnMemoryProcessor* info = _return_info->at(i); |
| 78 | if (!info->finished_return_to_vm()) { |
| 79 | if (info->return_to_vm(deadline)) { |
| 80 | return true; |
| 81 | } |
| 82 | } |
| 83 | } |
| 84 | return false; |
| 85 | } |
| 86 | |
| 87 | bool G1SegmentedArrayFreeMemoryTask::return_memory_to_os(jlong deadline) { |
| 88 | for (int i = 0; i < _return_info->length(); i++) { |
| 89 | G1ReturnMemoryProcessor* info = _return_info->at(i); |
| 90 | if (!info->finished_return_to_os()) { |
| 91 | if (info->return_to_os(deadline)) { |
| 92 | return true; |
| 93 | } |
| 94 | } |
| 95 | } |
| 96 | return false; |
| 97 | } |
| 98 | |
| 99 | bool G1SegmentedArrayFreeMemoryTask::cleanup_return_infos() { |
| 100 | for (int i = 0; i < _return_info->length(); i++) { |
| 101 | G1ReturnMemoryProcessor* info = _return_info->at(i); |
| 102 | delete info; |
| 103 | } |
| 104 | delete _return_info; |
| 105 | |
| 106 | _return_info = nullptr; |
| 107 | return false; |
| 108 | } |
| 109 | |
| 110 | bool G1SegmentedArrayFreeMemoryTask::free_excess_segmented_array_memory() { |
| 111 | jlong start = os::elapsed_counter(); |
| 112 | jlong end = start + |
| 113 | (os::elapsed_frequency() / 1000) * G1RemSetFreeMemoryStepDurationMillis; |
| 114 | |
| 115 | log_trace(gc, task)(!(LogImpl<(LogTag::_gc), (LogTag::_task), (LogTag::__NO_TAG ), (LogTag::__NO_TAG), (LogTag::__NO_TAG), (LogTag::__NO_TAG) >::is_level(LogLevel::Trace))) ? (void)0 : LogImpl<(LogTag ::_gc), (LogTag::_task), (LogTag::__NO_TAG), (LogTag::__NO_TAG ), (LogTag::__NO_TAG), (LogTag::__NO_TAG)>::write<LogLevel ::Trace>("Segmented Array Free Memory: Step start %1.3f end %1.3f", |
| 116 | TimeHelper::counter_to_millis(start), TimeHelper::counter_to_millis(end)); |
| 117 | |
| 118 | State next_state; |
| 119 | |
| 120 | do { |
| 121 | switch (_state) { |
| 122 | case State::CalculateUsed: { |
| 123 | if (calculate_return_infos(end)) { |
| 124 | next_state = _state; |
| 125 | return true; |
| 126 | } |
| 127 | next_state = State::ReturnToVM; |
| 128 | break; |
| 129 | } |
| 130 | case State::ReturnToVM: { |
| 131 | if (return_memory_to_vm(end)) { |
| 132 | next_state = _state; |
| 133 | return true; |
| 134 | } |
| 135 | next_state = State::ReturnToOS; |
| 136 | break; |
| 137 | } |
| 138 | case State::ReturnToOS: { |
| 139 | if (return_memory_to_os(end)) { |
| 140 | next_state = _state; |
Value stored to 'next_state' is never read | |
| 141 | return true; |
| 142 | } |
| 143 | next_state = State::Cleanup; |
| 144 | break; |
| 145 | } |
| 146 | case State::Cleanup: { |
| 147 | cleanup_return_infos(); |
| 148 | next_state = State::Inactive; |
| 149 | break; |
| 150 | } |
| 151 | default: |
| 152 | log_error(gc, task)(!(LogImpl<(LogTag::_gc), (LogTag::_task), (LogTag::__NO_TAG ), (LogTag::__NO_TAG), (LogTag::__NO_TAG), (LogTag::__NO_TAG) >::is_level(LogLevel::Error))) ? (void)0 : LogImpl<(LogTag ::_gc), (LogTag::_task), (LogTag::__NO_TAG), (LogTag::__NO_TAG ), (LogTag::__NO_TAG), (LogTag::__NO_TAG)>::write<LogLevel ::Error>("Should not try to free excess segmented array memory in %s state", get_state_name(_state)); |
| 153 | ShouldNotReachHere()do { (*g_assert_poison) = 'X';; report_should_not_reach_here( "/home/daniel/Projects/java/jdk/src/hotspot/share/gc/g1/g1SegmentedArrayFreeMemoryTask.cpp" , 153); ::breakpoint(); } while (0); |
| 154 | break; |
| 155 | } |
| 156 | |
| 157 | set_state(next_state); |
| 158 | } while (_state != State::Inactive && !deadline_exceeded(end)); |
| 159 | |
| 160 | log_trace(gc, task)(!(LogImpl<(LogTag::_gc), (LogTag::_task), (LogTag::__NO_TAG ), (LogTag::__NO_TAG), (LogTag::__NO_TAG), (LogTag::__NO_TAG) >::is_level(LogLevel::Trace))) ? (void)0 : LogImpl<(LogTag ::_gc), (LogTag::_task), (LogTag::__NO_TAG), (LogTag::__NO_TAG ), (LogTag::__NO_TAG), (LogTag::__NO_TAG)>::write<LogLevel ::Trace>("Segmented Array Free Memory: Step took %1.3fms, done %s", |
| 161 | TimeHelper::counter_to_millis(os::elapsed_counter() - start), |
| 162 | bool_to_str(_state == State::CalculateUsed)); |
| 163 | |
| 164 | return is_active(); |
| 165 | } |
| 166 | |
| 167 | void G1SegmentedArrayFreeMemoryTask::set_state(State new_state) { |
| 168 | log_trace(gc, task)(!(LogImpl<(LogTag::_gc), (LogTag::_task), (LogTag::__NO_TAG ), (LogTag::__NO_TAG), (LogTag::__NO_TAG), (LogTag::__NO_TAG) >::is_level(LogLevel::Trace))) ? (void)0 : LogImpl<(LogTag ::_gc), (LogTag::_task), (LogTag::__NO_TAG), (LogTag::__NO_TAG ), (LogTag::__NO_TAG), (LogTag::__NO_TAG)>::write<LogLevel ::Trace>("Segmented Array Free Memory: State change from %s to %s", |
| 169 | get_state_name(_state), |
| 170 | get_state_name(new_state)); |
| 171 | _state = new_state; |
| 172 | } |
| 173 | |
| 174 | bool G1SegmentedArrayFreeMemoryTask::is_active() const { |
| 175 | return _state != State::Inactive; |
| 176 | } |
| 177 | |
| 178 | jlong G1SegmentedArrayFreeMemoryTask::reschedule_delay_ms() const { |
| 179 | return G1RemSetFreeMemoryRescheduleDelayMillis; |
| 180 | } |
| 181 | |
| 182 | G1SegmentedArrayFreeMemoryTask::G1SegmentedArrayFreeMemoryTask(const char* name) : |
| 183 | G1ServiceTask(name), _state(State::CalculateUsed), _return_info(nullptr) { } |
| 184 | |
| 185 | void G1SegmentedArrayFreeMemoryTask::execute() { |
| 186 | SuspendibleThreadSetJoiner sts; |
| 187 | |
| 188 | if (free_excess_segmented_array_memory()) { |
| 189 | schedule(reschedule_delay_ms()); |
| 190 | } |
| 191 | } |
| 192 | |
| 193 | void G1SegmentedArrayFreeMemoryTask::notify_new_stats(G1SegmentedArrayMemoryStats* young_gen_stats, |
| 194 | G1SegmentedArrayMemoryStats* collection_set_candidate_stats) { |
| 195 | assert_at_safepoint_on_vm_thread()do { do { if (!(SafepointSynchronize::is_at_safepoint())) { ( *g_assert_poison) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/gc/g1/g1SegmentedArrayFreeMemoryTask.cpp" , 195, "assert(" "SafepointSynchronize::is_at_safepoint()" ") failed" , "should be at a safepoint"); ::breakpoint(); } } while (0); do { if (!(Thread::current_or_null() != __null)) { (*g_assert_poison ) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/gc/g1/g1SegmentedArrayFreeMemoryTask.cpp" , 195, "assert(" "Thread::current_or_null() != __null" ") failed" , "no current thread"); ::breakpoint(); } } while (0); do { if (!(Thread::current()->is_VM_thread())) { (*g_assert_poison ) = 'X';; report_vm_error("/home/daniel/Projects/java/jdk/src/hotspot/share/gc/g1/g1SegmentedArrayFreeMemoryTask.cpp" , 195, "assert(" "Thread::current()->is_VM_thread()" ") failed" , "current thread is not VM thread"); ::breakpoint(); } } while (0); } while (0); |
| 196 | |
| 197 | _total_used = *young_gen_stats; |
| 198 | _total_used.add(*collection_set_candidate_stats); |
| 199 | |
| 200 | if (!is_active()) { |
| 201 | set_state(State::CalculateUsed); |
| 202 | G1CollectedHeap::heap()->service_thread()->schedule_task(this, 0); |
| 203 | } |
| 204 | } |