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/heapRegionManager.inline.hpp"
  34 #include "gc_implementation/g1/heapRegionSet.inline.hpp"
  35 #include "runtime/orderAccess.inline.hpp"
  36 #include "utilities/taskqueue.hpp"
  37 
  38 // Inline functions for G1CollectedHeap
  39 
  40 inline AllocationContextStats& G1CollectedHeap::allocation_context_stats() {
  41   return _allocation_context_stats;
  42 }
  43 
  44 // Return the region with the given index. It assumes the index is valid.
  45 inline HeapRegion* G1CollectedHeap::region_at(uint index) const { return _hrm.at(index); }
  46 
  47 inline uint G1CollectedHeap::addr_to_region(HeapWord* addr) const {
  48   assert(is_in_reserved(addr),
  49          err_msg("Cannot calculate region index for address "PTR_FORMAT" that is outside of the heap ["PTR_FORMAT", "PTR_FORMAT")",
  50                  p2i(addr), p2i(reserved_region().start()), p2i(reserved_region().end())));
  51   return (uint)(pointer_delta(addr, reserved_region().start(), sizeof(uint8_t)) >> HeapRegion::LogOfHRGrainBytes);
  52 }
  53 
  54 inline HeapWord* G1CollectedHeap::bottom_addr_for_region(uint index) const {
  55   return _hrm.reserved().start() + index * HeapRegion::GrainWords;
  56 }
  57 
  58 template <class T>
  59 inline HeapRegion* G1CollectedHeap::heap_region_containing_raw(const T addr) const {
  60   assert(addr != NULL, "invariant");
  61   assert(is_in_g1_reserved((const void*) addr),
  62       err_msg("Address "PTR_FORMAT" is outside of the heap ranging from ["PTR_FORMAT" to "PTR_FORMAT")",
  63           p2i((void*)addr), p2i(g1_reserved().start()), p2i(g1_reserved().end())));
  64   return _hrm.addr_to_region((HeapWord*) addr);
  65 }
  66 
  67 template <class T>
  68 inline HeapRegion* G1CollectedHeap::heap_region_containing(const T addr) const {
  69   HeapRegion* hr = heap_region_containing_raw(addr);
  70   if (hr->is_continues_humongous()) {
  71     return hr->humongous_start_region();
  72   }
  73   return hr;
  74 }
  75 
  76 inline void G1CollectedHeap::reset_gc_time_stamp() {
  77   _gc_time_stamp = 0;
  78   OrderAccess::fence();
  79   // Clear the cached CSet starting regions and time stamps.
  80   // Their validity is dependent on the GC timestamp.
  81   clear_cset_start_regions();
  82 }
  83 
  84 inline void G1CollectedHeap::increment_gc_time_stamp() {
  85   ++_gc_time_stamp;
  86   OrderAccess::fence();
  87 }
  88 
  89 inline void G1CollectedHeap::old_set_remove(HeapRegion* hr) {
  90   _old_set.remove(hr);
  91 }
  92 
  93 inline bool G1CollectedHeap::obj_in_cs(oop obj) {
  94   HeapRegion* r = _hrm.addr_to_region((HeapWord*) obj);
  95   return r != NULL && r->in_collection_set();
  96 }
  97 
  98 inline HeapWord* G1CollectedHeap::attempt_allocation(size_t word_size,
  99                                                      unsigned int* gc_count_before_ret,
 100                                                      int* gclocker_retry_count_ret) {
 101   assert_heap_not_locked_and_not_at_safepoint();
 102   assert(!is_humongous(word_size), "attempt_allocation() should not "
 103          "be called for humongous allocation requests");
 104 
 105   AllocationContext_t context = AllocationContext::current();
 106   HeapWord* result = _allocator->mutator_alloc_region(context)->attempt_allocation(word_size,
 107                                                                                    false /* bot_updates */);
 108   if (result == NULL) {
 109     result = attempt_allocation_slow(word_size,
 110                                      context,
 111                                      gc_count_before_ret,
 112                                      gclocker_retry_count_ret);
 113   }
 114   assert_heap_not_locked();
 115   if (result != NULL) {
 116     dirty_young_block(result, word_size);
 117   }
 118   return result;
 119 }
 120 
 121 inline HeapWord* G1CollectedHeap::survivor_attempt_allocation(size_t word_size,
 122                                                               AllocationContext_t context) {
 123   assert(!is_humongous(word_size),
 124          "we should not be seeing humongous-size allocations in this path");
 125 
 126   HeapWord* result = _allocator->survivor_gc_alloc_region(context)->attempt_allocation(word_size,
 127                                                                                        false /* bot_updates */);
 128   if (result == NULL) {
 129     MutexLockerEx x(FreeList_lock, Mutex::_no_safepoint_check_flag);
 130     result = _allocator->survivor_gc_alloc_region(context)->attempt_allocation_locked(word_size,
 131                                                                                       false /* bot_updates */);
 132   }
 133   if (result != NULL) {
 134     dirty_young_block(result, word_size);
 135   }
 136   return result;
 137 }
 138 
 139 inline HeapWord* G1CollectedHeap::old_attempt_allocation(size_t word_size,
 140                                                          AllocationContext_t context) {
 141   assert(!is_humongous(word_size),
 142          "we should not be seeing humongous-size allocations in this path");
 143 
 144   HeapWord* result = _allocator->old_gc_alloc_region(context)->attempt_allocation(word_size,
 145                                                                                   true /* bot_updates */);
 146   if (result == NULL) {
 147     MutexLockerEx x(FreeList_lock, Mutex::_no_safepoint_check_flag);
 148     result = _allocator->old_gc_alloc_region(context)->attempt_allocation_locked(word_size,
 149                                                                                  true /* bot_updates */);
 150   }
 151   return result;
 152 }
 153 
 154 // It dirties the cards that cover the block so that so that the post
 155 // write barrier never queues anything when updating objects on this
 156 // block. It is assumed (and in fact we assert) that the block
 157 // belongs to a young region.
 158 inline void
 159 G1CollectedHeap::dirty_young_block(HeapWord* start, size_t word_size) {
 160   assert_heap_not_locked();
 161 
 162   // Assign the containing region to containing_hr so that we don't
 163   // have to keep calling heap_region_containing_raw() in the
 164   // asserts below.
 165   DEBUG_ONLY(HeapRegion* containing_hr = heap_region_containing_raw(start);)
 166   assert(word_size > 0, "pre-condition");
 167   assert(containing_hr->is_in(start), "it should contain start");
 168   assert(containing_hr->is_young(), "it should be young");
 169   assert(!containing_hr->is_humongous(), "it should not be humongous");
 170 
 171   HeapWord* end = start + word_size;
 172   assert(containing_hr->is_in(end - 1), "it should also contain end - 1");
 173 
 174   MemRegion mr(start, end);
 175   g1_barrier_set()->g1_mark_as_young(mr);
 176 }
 177 
 178 inline RefToScanQueue* G1CollectedHeap::task_queue(int i) const {
 179   return _task_queues->queue(i);
 180 }
 181 
 182 inline bool G1CollectedHeap::isMarkedPrev(oop obj) const {
 183   return _cm->prevMarkBitMap()->isMarked((HeapWord *)obj);
 184 }
 185 
 186 inline bool G1CollectedHeap::isMarkedNext(oop obj) const {
 187   return _cm->nextMarkBitMap()->isMarked((HeapWord *)obj);
 188 }
 189 
 190 // This is a fast test on whether a reference points into the
 191 // collection set or not. Assume that the reference
 192 // points into the heap.
 193 inline bool G1CollectedHeap::is_in_cset(oop obj) {
 194   bool ret = _in_cset_fast_test.is_in_cset((HeapWord*)obj);
 195   // let's make sure the result is consistent with what the slower
 196   // test returns
 197   assert( ret || !obj_in_cs(obj), "sanity");
 198   assert(!ret ||  obj_in_cs(obj), "sanity");
 199   return ret;
 200 }
 201 
 202 bool G1CollectedHeap::is_in_cset_or_humongous(const oop obj) {
 203   return _in_cset_fast_test.is_in_cset_or_humongous((HeapWord*)obj);
 204 }
 205 
 206 G1CollectedHeap::in_cset_state_t G1CollectedHeap::in_cset_state(const oop obj) {
 207   return _in_cset_fast_test.at((HeapWord*)obj);
 208 }
 209 
 210 void G1CollectedHeap::register_humongous_region_with_in_cset_fast_test(uint index) {
 211   _in_cset_fast_test.set_humongous(index);
 212 }
 213 
 214 #ifndef PRODUCT
 215 // Support for G1EvacuationFailureALot
 216 
 217 inline bool
 218 G1CollectedHeap::evacuation_failure_alot_for_gc_type(bool gcs_are_young,
 219                                                      bool during_initial_mark,
 220                                                      bool during_marking) {
 221   bool res = false;
 222   if (during_marking) {
 223     res |= G1EvacuationFailureALotDuringConcMark;
 224   }
 225   if (during_initial_mark) {
 226     res |= G1EvacuationFailureALotDuringInitialMark;
 227   }
 228   if (gcs_are_young) {
 229     res |= G1EvacuationFailureALotDuringYoungGC;
 230   } else {
 231     // GCs are mixed
 232     res |= G1EvacuationFailureALotDuringMixedGC;
 233   }
 234   return res;
 235 }
 236 
 237 inline void
 238 G1CollectedHeap::set_evacuation_failure_alot_for_current_gc() {
 239   if (G1EvacuationFailureALot) {
 240     // Note we can't assert that _evacuation_failure_alot_for_current_gc
 241     // is clear here. It may have been set during a previous GC but that GC
 242     // did not copy enough objects (i.e. G1EvacuationFailureALotCount) to
 243     // trigger an evacuation failure and clear the flags and and counts.
 244 
 245     // Check if we have gone over the interval.
 246     const size_t gc_num = total_collections();
 247     const size_t elapsed_gcs = gc_num - _evacuation_failure_alot_gc_number;
 248 
 249     _evacuation_failure_alot_for_current_gc = (elapsed_gcs >= G1EvacuationFailureALotInterval);
 250 
 251     // Now check if G1EvacuationFailureALot is enabled for the current GC type.
 252     const bool gcs_are_young = g1_policy()->gcs_are_young();
 253     const bool during_im = g1_policy()->during_initial_mark_pause();
 254     const bool during_marking = mark_in_progress();
 255 
 256     _evacuation_failure_alot_for_current_gc &=
 257       evacuation_failure_alot_for_gc_type(gcs_are_young,
 258                                           during_im,
 259                                           during_marking);
 260   }
 261 }
 262 
 263 inline bool G1CollectedHeap::evacuation_should_fail() {
 264   if (!G1EvacuationFailureALot || !_evacuation_failure_alot_for_current_gc) {
 265     return false;
 266   }
 267   // G1EvacuationFailureALot is in effect for current GC
 268   // Access to _evacuation_failure_alot_count is not atomic;
 269   // the value does not have to be exact.
 270   if (++_evacuation_failure_alot_count < G1EvacuationFailureALotCount) {
 271     return false;
 272   }
 273   _evacuation_failure_alot_count = 0;
 274   return true;
 275 }
 276 
 277 inline void G1CollectedHeap::reset_evacuation_should_fail() {
 278   if (G1EvacuationFailureALot) {
 279     _evacuation_failure_alot_gc_number = total_collections();
 280     _evacuation_failure_alot_count = 0;
 281     _evacuation_failure_alot_for_current_gc = false;
 282   }
 283 }
 284 #endif  // #ifndef PRODUCT
 285 
 286 inline bool G1CollectedHeap::is_in_young(const oop obj) {
 287   if (obj == NULL) {
 288     return false;
 289   }
 290   return heap_region_containing(obj)->is_young();
 291 }
 292 
 293 // We don't need barriers for initializing stores to objects
 294 // in the young gen: for the SATB pre-barrier, there is no
 295 // pre-value that needs to be remembered; for the remembered-set
 296 // update logging post-barrier, we don't maintain remembered set
 297 // information for young gen objects.
 298 inline bool G1CollectedHeap::can_elide_initializing_store_barrier(oop new_obj) {
 299   return is_in_young(new_obj);
 300 }
 301 
 302 inline bool G1CollectedHeap::is_obj_dead(const oop obj) const {
 303   if (obj == NULL) {
 304     return false;
 305   }
 306   return is_obj_dead(obj, heap_region_containing(obj));
 307 }
 308 
 309 inline bool G1CollectedHeap::is_obj_ill(const oop obj) const {
 310   if (obj == NULL) {
 311     return false;
 312   }
 313   return is_obj_ill(obj, heap_region_containing(obj));
 314 }
 315 
 316 inline void G1CollectedHeap::set_humongous_is_live(oop obj) {
 317   uint region = addr_to_region((HeapWord*)obj);
 318   // We not only set the "live" flag in the humongous_is_live table, but also
 319   // reset the entry in the _in_cset_fast_test table so that subsequent references
 320   // to the same humongous object do not go into the slow path again.
 321   // This is racy, as multiple threads may at the same time enter here, but this
 322   // is benign.
 323   // During collection we only ever set the "live" flag, and only ever clear the
 324   // entry in the in_cset_fast_table.
 325   // We only ever evaluate the contents of these tables (in the VM thread) after
 326   // having synchronized the worker threads with the VM thread, or in the same
 327   // thread (i.e. within the VM thread).
 328   if (!_humongous_is_live.is_live(region)) {
 329     _humongous_is_live.set_live(region);
 330     _in_cset_fast_test.clear_humongous(region);
 331   }
 332 }
 333 
 334 #endif // SHARE_VM_GC_IMPLEMENTATION_G1_G1COLLECTEDHEAP_INLINE_HPP