1 /*
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   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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   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.
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   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  *
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  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
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  24 
  25 #ifndef SHARE_VM_GC_G1_G1COLLECTEDHEAP_INLINE_HPP
  26 #define SHARE_VM_GC_G1_G1COLLECTEDHEAP_INLINE_HPP
  27 
  28 #include "gc/g1/g1CollectedHeap.hpp"
  29 #include "gc/g1/g1CollectorState.hpp"
  30 #include "gc/g1/g1ConcurrentMark.inline.hpp"
  31 #include "gc/g1/g1SATBCardTableModRefBS.hpp"
  32 #include "gc/g1/heapRegionManager.inline.hpp"
  33 #include "gc/g1/heapRegionSet.inline.hpp"
  34 #include "gc/shared/taskqueue.hpp"
  35 #include "runtime/orderAccess.inline.hpp"
  36 
  37 G1EvacStats* G1CollectedHeap::alloc_buffer_stats(InCSetState dest) {
  38   switch (dest.value()) {
  39     case InCSetState::Young:
  40       return &_survivor_evac_stats;
  41     case InCSetState::Old:
  42       return &_old_evac_stats;
  43     default:
  44       ShouldNotReachHere();
  45       return NULL; // Keep some compilers happy
  46   }
  47 }
  48 
  49 size_t G1CollectedHeap::desired_plab_sz(InCSetState dest) {
  50   size_t gclab_word_size = alloc_buffer_stats(dest)->desired_plab_sz(G1CollectedHeap::heap()->workers()->active_workers());
  51   // Prevent humongous PLAB sizes for two reasons:
  52   // * PLABs are allocated using a similar paths as oops, but should
  53   //   never be in a humongous region
  54   // * Allowing humongous PLABs needlessly churns the region free lists
  55   return MIN2(_humongous_object_threshold_in_words, gclab_word_size);
  56 }
  57 
  58 // Inline functions for G1CollectedHeap
  59 
  60 inline AllocationContextStats& G1CollectedHeap::allocation_context_stats() {
  61   return _allocation_context_stats;
  62 }
  63 
  64 // Return the region with the given index. It assumes the index is valid.
  65 inline HeapRegion* G1CollectedHeap::region_at(uint index) const { return _hrm.at(index); }
  66 
  67 inline HeapRegion* G1CollectedHeap::next_region_in_humongous(HeapRegion* hr) const {
  68   return _hrm.next_region_in_humongous(hr);
  69 }
  70 
  71 inline uint G1CollectedHeap::addr_to_region(HeapWord* addr) const {
  72   assert(is_in_reserved(addr),
  73          "Cannot calculate region index for address " PTR_FORMAT " that is outside of the heap [" PTR_FORMAT ", " PTR_FORMAT ")",
  74          p2i(addr), p2i(reserved_region().start()), p2i(reserved_region().end()));
  75   return (uint)(pointer_delta(addr, reserved_region().start(), sizeof(uint8_t)) >> HeapRegion::LogOfHRGrainBytes);
  76 }
  77 
  78 inline HeapWord* G1CollectedHeap::bottom_addr_for_region(uint index) const {
  79   return _hrm.reserved().start() + index * HeapRegion::GrainWords;
  80 }
  81 
  82 template <class T>
  83 inline HeapRegion* G1CollectedHeap::heap_region_containing(const T addr) const {
  84   assert(addr != NULL, "invariant");
  85   assert(is_in_g1_reserved((const void*) addr),
  86          "Address " PTR_FORMAT " is outside of the heap ranging from [" PTR_FORMAT " to " PTR_FORMAT ")",
  87          p2i((void*)addr), p2i(g1_reserved().start()), p2i(g1_reserved().end()));
  88   return _hrm.addr_to_region((HeapWord*) addr);
  89 }
  90 
  91 inline void G1CollectedHeap::reset_gc_time_stamp() {
  92   assert_at_safepoint(true);
  93   _gc_time_stamp = 0;
  94 }
  95 
  96 inline void G1CollectedHeap::increment_gc_time_stamp() {
  97   assert_at_safepoint(true);
  98   ++_gc_time_stamp;
  99 }
 100 
 101 inline void G1CollectedHeap::old_set_add(HeapRegion* hr) {
 102   _old_set.add(hr);
 103 }
 104 
 105 inline void G1CollectedHeap::old_set_remove(HeapRegion* hr) {
 106   _old_set.remove(hr);
 107 }
 108 
 109 // It dirties the cards that cover the block so that the post
 110 // write barrier never queues anything when updating objects on this
 111 // block. It is assumed (and in fact we assert) that the block
 112 // belongs to a young region.
 113 inline void
 114 G1CollectedHeap::dirty_young_block(HeapWord* start, size_t word_size) {
 115   assert_heap_not_locked();
 116 
 117   // Assign the containing region to containing_hr so that we don't
 118   // have to keep calling heap_region_containing() in the
 119   // asserts below.
 120   DEBUG_ONLY(HeapRegion* containing_hr = heap_region_containing(start);)
 121   assert(word_size > 0, "pre-condition");
 122   assert(containing_hr->is_in(start), "it should contain start");
 123   assert(containing_hr->is_young(), "it should be young");
 124   assert(!containing_hr->is_humongous(), "it should not be humongous");
 125 
 126   HeapWord* end = start + word_size;
 127   assert(containing_hr->is_in(end - 1), "it should also contain end - 1");
 128 
 129   MemRegion mr(start, end);
 130   g1_barrier_set()->g1_mark_as_young(mr);
 131 }
 132 
 133 inline RefToScanQueue* G1CollectedHeap::task_queue(uint i) const {
 134   return _task_queues->queue(i);
 135 }
 136 
 137 inline bool G1CollectedHeap::isMarkedNext(oop obj) const {
 138   return _cm->nextMarkBitMap()->isMarked((HeapWord *)obj);
 139 }
 140 
 141 inline bool G1CollectedHeap::is_in_cset(oop obj) {
 142   return is_in_cset((HeapWord*)obj);
 143 }
 144 
 145 inline bool G1CollectedHeap::is_in_cset(HeapWord* addr) {
 146   return _in_cset_fast_test.is_in_cset(addr);
 147 }
 148 
 149 bool G1CollectedHeap::is_in_cset(const HeapRegion* hr) {
 150   return _in_cset_fast_test.is_in_cset(hr);
 151 }
 152 
 153 bool G1CollectedHeap::is_in_cset_or_humongous(const oop obj) {
 154   return _in_cset_fast_test.is_in_cset_or_humongous((HeapWord*)obj);
 155 }
 156 
 157 InCSetState G1CollectedHeap::in_cset_state(const oop obj) {
 158   return _in_cset_fast_test.at((HeapWord*)obj);
 159 }
 160 
 161 void G1CollectedHeap::register_humongous_region_with_cset(uint index) {
 162   _in_cset_fast_test.set_humongous(index);
 163 }
 164 
 165 #ifndef PRODUCT
 166 // Support for G1EvacuationFailureALot
 167 
 168 inline bool
 169 G1CollectedHeap::evacuation_failure_alot_for_gc_type(bool gcs_are_young,
 170                                                      bool during_initial_mark,
 171                                                      bool during_marking) {
 172   bool res = false;
 173   if (during_marking) {
 174     res |= G1EvacuationFailureALotDuringConcMark;
 175   }
 176   if (during_initial_mark) {
 177     res |= G1EvacuationFailureALotDuringInitialMark;
 178   }
 179   if (gcs_are_young) {
 180     res |= G1EvacuationFailureALotDuringYoungGC;
 181   } else {
 182     // GCs are mixed
 183     res |= G1EvacuationFailureALotDuringMixedGC;
 184   }
 185   return res;
 186 }
 187 
 188 inline void
 189 G1CollectedHeap::set_evacuation_failure_alot_for_current_gc() {
 190   if (G1EvacuationFailureALot) {
 191     // Note we can't assert that _evacuation_failure_alot_for_current_gc
 192     // is clear here. It may have been set during a previous GC but that GC
 193     // did not copy enough objects (i.e. G1EvacuationFailureALotCount) to
 194     // trigger an evacuation failure and clear the flags and and counts.
 195 
 196     // Check if we have gone over the interval.
 197     const size_t gc_num = total_collections();
 198     const size_t elapsed_gcs = gc_num - _evacuation_failure_alot_gc_number;
 199 
 200     _evacuation_failure_alot_for_current_gc = (elapsed_gcs >= G1EvacuationFailureALotInterval);
 201 
 202     // Now check if G1EvacuationFailureALot is enabled for the current GC type.
 203     const bool gcs_are_young = collector_state()->gcs_are_young();
 204     const bool during_im = collector_state()->during_initial_mark_pause();
 205     const bool during_marking = collector_state()->mark_in_progress();
 206 
 207     _evacuation_failure_alot_for_current_gc &=
 208       evacuation_failure_alot_for_gc_type(gcs_are_young,
 209                                           during_im,
 210                                           during_marking);
 211   }
 212 }
 213 
 214 inline bool G1CollectedHeap::evacuation_should_fail() {
 215   if (!G1EvacuationFailureALot || !_evacuation_failure_alot_for_current_gc) {
 216     return false;
 217   }
 218   // G1EvacuationFailureALot is in effect for current GC
 219   // Access to _evacuation_failure_alot_count is not atomic;
 220   // the value does not have to be exact.
 221   if (++_evacuation_failure_alot_count < G1EvacuationFailureALotCount) {
 222     return false;
 223   }
 224   _evacuation_failure_alot_count = 0;
 225   return true;
 226 }
 227 
 228 inline void G1CollectedHeap::reset_evacuation_should_fail() {
 229   if (G1EvacuationFailureALot) {
 230     _evacuation_failure_alot_gc_number = total_collections();
 231     _evacuation_failure_alot_count = 0;
 232     _evacuation_failure_alot_for_current_gc = false;
 233   }
 234 }
 235 #endif  // #ifndef PRODUCT
 236 
 237 inline bool G1CollectedHeap::is_in_young(const oop obj) {
 238   if (obj == NULL) {
 239     return false;
 240   }
 241   return heap_region_containing(obj)->is_young();
 242 }
 243 
 244 // We don't need barriers for initializing stores to objects
 245 // in the young gen: for the SATB pre-barrier, there is no
 246 // pre-value that needs to be remembered; for the remembered-set
 247 // update logging post-barrier, we don't maintain remembered set
 248 // information for young gen objects.
 249 inline bool G1CollectedHeap::can_elide_initializing_store_barrier(oop new_obj) {
 250   return is_in_young(new_obj);
 251 }
 252 
 253 inline bool G1CollectedHeap::is_obj_dead(const oop obj) const {
 254   if (obj == NULL) {
 255     return false;
 256   }
 257   return is_obj_dead(obj, heap_region_containing(obj));
 258 }
 259 
 260 inline bool G1CollectedHeap::is_obj_ill(const oop obj) const {
 261   if (obj == NULL) {
 262     return false;
 263   }
 264   return is_obj_ill(obj, heap_region_containing(obj));
 265 }
 266 
 267 inline void G1CollectedHeap::set_humongous_reclaim_candidate(uint region, bool value) {
 268   assert(_hrm.at(region)->is_starts_humongous(), "Must start a humongous object");
 269   _humongous_reclaim_candidates.set_candidate(region, value);
 270 }
 271 
 272 inline bool G1CollectedHeap::is_humongous_reclaim_candidate(uint region) {
 273   assert(_hrm.at(region)->is_starts_humongous(), "Must start a humongous object");
 274   return _humongous_reclaim_candidates.is_candidate(region);
 275 }
 276 
 277 inline void G1CollectedHeap::set_humongous_is_live(oop obj) {
 278   uint region = addr_to_region((HeapWord*)obj);
 279   // Clear the flag in the humongous_reclaim_candidates table.  Also
 280   // reset the entry in the _in_cset_fast_test table so that subsequent references
 281   // to the same humongous object do not go into the slow path again.
 282   // This is racy, as multiple threads may at the same time enter here, but this
 283   // is benign.
 284   // During collection we only ever clear the "candidate" flag, and only ever clear the
 285   // entry in the in_cset_fast_table.
 286   // We only ever evaluate the contents of these tables (in the VM thread) after
 287   // having synchronized the worker threads with the VM thread, or in the same
 288   // thread (i.e. within the VM thread).
 289   if (is_humongous_reclaim_candidate(region)) {
 290     set_humongous_reclaim_candidate(region, false);
 291     _in_cset_fast_test.clear_humongous(region);
 292   }
 293 }
 294 
 295 #endif // SHARE_VM_GC_G1_G1COLLECTEDHEAP_INLINE_HPP