1 /*
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   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
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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_IMPLEMENTATION_G1_G1COLLECTEDHEAP_INLINE_HPP
  26 #define SHARE_VM_GC_IMPLEMENTATION_G1_G1COLLECTEDHEAP_INLINE_HPP
  27 
  28 #include "gc_implementation/g1/concurrentMark.hpp"
  29 #include "gc_implementation/g1/g1CollectedHeap.hpp"
  30 #include "gc_implementation/g1/g1AllocRegion.inline.hpp"
  31 #include "gc_implementation/g1/g1CollectorPolicy.hpp"
  32 #include "gc_implementation/g1/g1SATBCardTableModRefBS.hpp"
  33 #include "gc_implementation/g1/heapRegionSet.inline.hpp"
  34 #include "gc_implementation/g1/heapRegionSeq.inline.hpp"
  35 #include "runtime/orderAccess.inline.hpp"
  36 #include "utilities/taskqueue.hpp"
  37 
  38 // Inline functions for G1CollectedHeap
  39 
  40 // Return the region with the given index. It assumes the index is valid.
  41 inline HeapRegion* G1CollectedHeap::region_at(uint index) const { return _hrs.at(index); }
  42 
  43 inline uint G1CollectedHeap::addr_to_region(HeapWord* addr) const {
  44   assert(is_in_reserved(addr),
  45          err_msg("Cannot calculate region index for address "PTR_FORMAT" that is outside of the heap ["PTR_FORMAT", "PTR_FORMAT")",
  46                  p2i(addr), p2i(_reserved.start()), p2i(_reserved.end())));
  47   return (uint)(pointer_delta(addr, _reserved.start(), sizeof(uint8_t)) >> HeapRegion::LogOfHRGrainBytes);
  48 }
  49 
  50 template <class T>
  51 inline HeapRegion*
  52 G1CollectedHeap::heap_region_containing_raw(const T addr) const {
  53   assert(addr != NULL, "invariant");
  54   assert(_g1_reserved.contains((const void*) addr),
  55       err_msg("Address "PTR_FORMAT" is outside of the heap ranging from ["PTR_FORMAT" to "PTR_FORMAT")",
  56           p2i((void*)addr), p2i(_g1_reserved.start()), p2i(_g1_reserved.end())));
  57   return _hrs.addr_to_region((HeapWord*) addr);
  58 }
  59 
  60 template <class T>
  61 inline HeapRegion*
  62 G1CollectedHeap::heap_region_containing(const T addr) const {
  63   HeapRegion* hr = heap_region_containing_raw(addr);
  64   if (hr->continuesHumongous()) {
  65     return hr->humongous_start_region();
  66   }
  67   return hr;
  68 }
  69 
  70 inline void G1CollectedHeap::reset_gc_time_stamp() {
  71   _gc_time_stamp = 0;
  72   OrderAccess::fence();
  73   // Clear the cached CSet starting regions and time stamps.
  74   // Their validity is dependent on the GC timestamp.
  75   clear_cset_start_regions();
  76 }
  77 
  78 inline void G1CollectedHeap::increment_gc_time_stamp() {
  79   ++_gc_time_stamp;
  80   OrderAccess::fence();
  81 }
  82 
  83 inline void G1CollectedHeap::old_set_remove(HeapRegion* hr) {
  84   _old_set.remove(hr);
  85 }
  86 
  87 inline bool G1CollectedHeap::obj_in_cs(oop obj) {
  88   HeapRegion* r = _hrs.addr_to_region((HeapWord*) obj);
  89   return r != NULL && r->in_collection_set();
  90 }
  91 
  92 inline HeapWord*
  93 G1CollectedHeap::attempt_allocation(size_t word_size,
  94                                     unsigned int* gc_count_before_ret,
  95                                     int* gclocker_retry_count_ret) {
  96   assert_heap_not_locked_and_not_at_safepoint();
  97   assert(!isHumongous(word_size), "attempt_allocation() should not "
  98          "be called for humongous allocation requests");
  99 
 100   HeapWord* result = _mutator_alloc_region.attempt_allocation(word_size,
 101                                                       false /* bot_updates */);
 102   if (result == NULL) {
 103     result = attempt_allocation_slow(word_size,
 104                                      gc_count_before_ret,
 105                                      gclocker_retry_count_ret);
 106   }
 107   assert_heap_not_locked();
 108   if (result != NULL) {
 109     dirty_young_block(result, word_size);
 110   }
 111   return result;
 112 }
 113 
 114 inline HeapWord* G1CollectedHeap::survivor_attempt_allocation(size_t
 115                                                               word_size) {
 116   assert(!isHumongous(word_size),
 117          "we should not be seeing humongous-size allocations in this path");
 118 
 119   HeapWord* result = _survivor_gc_alloc_region.attempt_allocation(word_size,
 120                                                       false /* bot_updates */);
 121   if (result == NULL) {
 122     MutexLockerEx x(FreeList_lock, Mutex::_no_safepoint_check_flag);
 123     result = _survivor_gc_alloc_region.attempt_allocation_locked(word_size,
 124                                                       false /* bot_updates */);
 125   }
 126   if (result != NULL) {
 127     dirty_young_block(result, word_size);
 128   }
 129   return result;
 130 }
 131 
 132 inline HeapWord* G1CollectedHeap::old_attempt_allocation(size_t word_size) {
 133   assert(!isHumongous(word_size),
 134          "we should not be seeing humongous-size allocations in this path");
 135 
 136   HeapWord* result = _old_gc_alloc_region.attempt_allocation(word_size,
 137                                                        true /* bot_updates */);
 138   if (result == NULL) {
 139     MutexLockerEx x(FreeList_lock, Mutex::_no_safepoint_check_flag);
 140     result = _old_gc_alloc_region.attempt_allocation_locked(word_size,
 141                                                        true /* bot_updates */);
 142   }
 143   return result;
 144 }
 145 
 146 // It dirties the cards that cover the block so that so that the post
 147 // write barrier never queues anything when updating objects on this
 148 // block. It is assumed (and in fact we assert) that the block
 149 // belongs to a young region.
 150 inline void
 151 G1CollectedHeap::dirty_young_block(HeapWord* start, size_t word_size) {
 152   assert_heap_not_locked();
 153 
 154   // Assign the containing region to containing_hr so that we don't
 155   // have to keep calling heap_region_containing_raw() in the
 156   // asserts below.
 157   DEBUG_ONLY(HeapRegion* containing_hr = heap_region_containing_raw(start);)
 158   assert(word_size > 0, "pre-condition");
 159   assert(containing_hr->is_in(start), "it should contain start");
 160   assert(containing_hr->is_young(), "it should be young");
 161   assert(!containing_hr->isHumongous(), "it should not be humongous");
 162 
 163   HeapWord* end = start + word_size;
 164   assert(containing_hr->is_in(end - 1), "it should also contain end - 1");
 165 
 166   MemRegion mr(start, end);
 167   g1_barrier_set()->g1_mark_as_young(mr);
 168 }
 169 
 170 inline RefToScanQueue* G1CollectedHeap::task_queue(int i) const {
 171   return _task_queues->queue(i);
 172 }
 173 
 174 inline bool G1CollectedHeap::isMarkedPrev(oop obj) const {
 175   return _cm->prevMarkBitMap()->isMarked((HeapWord *)obj);
 176 }
 177 
 178 inline bool G1CollectedHeap::isMarkedNext(oop obj) const {
 179   return _cm->nextMarkBitMap()->isMarked((HeapWord *)obj);
 180 }
 181 
 182 // This is a fast test on whether a reference points into the
 183 // collection set or not. Assume that the reference
 184 // points into the heap.
 185 inline bool G1CollectedHeap::is_in_cset(oop obj) {
 186   bool ret = _in_cset_fast_test.is_in_cset((HeapWord*)obj);
 187   // let's make sure the result is consistent with what the slower
 188   // test returns
 189   assert( ret || !obj_in_cs(obj), "sanity");
 190   assert(!ret ||  obj_in_cs(obj), "sanity");
 191   return ret;
 192 }
 193 
 194 bool G1CollectedHeap::is_in_cset_or_humongous(const oop obj) {
 195   return _in_cset_fast_test.is_in_cset_or_humongous((HeapWord*)obj);
 196 }
 197 
 198 bool G1CollectedHeap::is_in_cset_and_humongous(const oop obj) {
 199   return _in_cset_fast_test.is_in_cset_and_humongous((HeapWord*)obj);
 200 }
 201 
 202 void G1CollectedHeap::register_humongous_region_with_in_cset_fast_test(uint index) {
 203   _in_cset_fast_test.set_humongous(index);
 204 }
 205 
 206 #ifndef PRODUCT
 207 // Support for G1EvacuationFailureALot
 208 
 209 inline bool
 210 G1CollectedHeap::evacuation_failure_alot_for_gc_type(bool gcs_are_young,
 211                                                      bool during_initial_mark,
 212                                                      bool during_marking) {
 213   bool res = false;
 214   if (during_marking) {
 215     res |= G1EvacuationFailureALotDuringConcMark;
 216   }
 217   if (during_initial_mark) {
 218     res |= G1EvacuationFailureALotDuringInitialMark;
 219   }
 220   if (gcs_are_young) {
 221     res |= G1EvacuationFailureALotDuringYoungGC;
 222   } else {
 223     // GCs are mixed
 224     res |= G1EvacuationFailureALotDuringMixedGC;
 225   }
 226   return res;
 227 }
 228 
 229 inline void
 230 G1CollectedHeap::set_evacuation_failure_alot_for_current_gc() {
 231   if (G1EvacuationFailureALot) {
 232     // Note we can't assert that _evacuation_failure_alot_for_current_gc
 233     // is clear here. It may have been set during a previous GC but that GC
 234     // did not copy enough objects (i.e. G1EvacuationFailureALotCount) to
 235     // trigger an evacuation failure and clear the flags and and counts.
 236 
 237     // Check if we have gone over the interval.
 238     const size_t gc_num = total_collections();
 239     const size_t elapsed_gcs = gc_num - _evacuation_failure_alot_gc_number;
 240 
 241     _evacuation_failure_alot_for_current_gc = (elapsed_gcs >= G1EvacuationFailureALotInterval);
 242 
 243     // Now check if G1EvacuationFailureALot is enabled for the current GC type.
 244     const bool gcs_are_young = g1_policy()->gcs_are_young();
 245     const bool during_im = g1_policy()->during_initial_mark_pause();
 246     const bool during_marking = mark_in_progress();
 247 
 248     _evacuation_failure_alot_for_current_gc &=
 249       evacuation_failure_alot_for_gc_type(gcs_are_young,
 250                                           during_im,
 251                                           during_marking);
 252   }
 253 }
 254 
 255 inline bool
 256 G1CollectedHeap::evacuation_should_fail() {
 257   if (!G1EvacuationFailureALot || !_evacuation_failure_alot_for_current_gc) {
 258     return false;
 259   }
 260   // G1EvacuationFailureALot is in effect for current GC
 261   // Access to _evacuation_failure_alot_count is not atomic;
 262   // the value does not have to be exact.
 263   if (++_evacuation_failure_alot_count < G1EvacuationFailureALotCount) {
 264     return false;
 265   }
 266   _evacuation_failure_alot_count = 0;
 267   return true;
 268 }
 269 
 270 inline void G1CollectedHeap::reset_evacuation_should_fail() {
 271   if (G1EvacuationFailureALot) {
 272     _evacuation_failure_alot_gc_number = total_collections();
 273     _evacuation_failure_alot_count = 0;
 274     _evacuation_failure_alot_for_current_gc = false;
 275   }
 276 }
 277 #endif  // #ifndef PRODUCT
 278 
 279 inline bool G1CollectedHeap::is_in_young(const oop obj) {
 280   if (obj == NULL) {
 281     return false;
 282   }
 283   return heap_region_containing(obj)->is_young();
 284 }
 285 
 286 // We don't need barriers for initializing stores to objects
 287 // in the young gen: for the SATB pre-barrier, there is no
 288 // pre-value that needs to be remembered; for the remembered-set
 289 // update logging post-barrier, we don't maintain remembered set
 290 // information for young gen objects.
 291 inline bool G1CollectedHeap::can_elide_initializing_store_barrier(oop new_obj) {
 292   return is_in_young(new_obj);
 293 }
 294 
 295 inline bool G1CollectedHeap::is_obj_dead(const oop obj) const {
 296   if (obj == NULL) {
 297     return false;
 298   }
 299   return is_obj_dead(obj, heap_region_containing(obj));
 300 }
 301 
 302 inline bool G1CollectedHeap::is_obj_ill(const oop obj) const {
 303   if (obj == NULL) {
 304     return false;
 305   }
 306   return is_obj_ill(obj, heap_region_containing(obj));
 307 }
 308 
 309 inline void G1CollectedHeap::set_humongous_is_live(oop obj) {
 310   uint region = addr_to_region((HeapWord*)obj);
 311   // We not only set the "live" flag in the humongous_is_live table, but also
 312   // reset the entry in the _in_cset_fast_test table so that subsequent references
 313   // to the same humongous object do not go into the slow path again.
 314   // This is racy, as multiple threads may at the same time enter here, but this
 315   // is benign.
 316   // During collection we only ever set the "live" flag, and only ever clear the
 317   // entry in the in_cset_fast_table.
 318   // We only ever evaluate the contents of these tables (in the VM thread) after
 319   // having synchronized the worker threads with the VM thread, or in the same
 320   // thread (i.e. within the VM thread).
 321   if (!_humongous_is_live.is_live(region)) {
 322     _humongous_is_live.set_live(region);
 323     _in_cset_fast_test.clear_humongous(region);
 324   }
 325 }
 326 
 327 #endif // SHARE_VM_GC_IMPLEMENTATION_G1_G1COLLECTEDHEAP_INLINE_HPP