src/share/vm/gc_implementation/g1/g1ParScanThreadState.cpp

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rev 6626 : imported patch 8035400-move-g1parscanthreadstate-into-own-files
rev 6627 : imported patch 8035400-2-bengt-fixes
rev 6628 : imported patch 8035401-fix-visibility-of-g1parscanthreadstate
rev 6629 : imported patch 8035401-3-fix-constructor
rev 6630 : imported patch 8035401-2-another-inline-try


  52   // non-young regions (where the age is -1)
  53   // We also add a few elements at the beginning and at the end in
  54   // an attempt to eliminate cache contention
  55   uint real_length = 1 + _g1h->g1_policy()->young_cset_region_length();
  56   uint array_length = PADDING_ELEM_NUM +
  57                       real_length +
  58                       PADDING_ELEM_NUM;
  59   _surviving_young_words_base = NEW_C_HEAP_ARRAY(size_t, array_length, mtGC);
  60   if (_surviving_young_words_base == NULL)
  61     vm_exit_out_of_memory(array_length * sizeof(size_t), OOM_MALLOC_ERROR,
  62                           "Not enough space for young surv histo.");
  63   _surviving_young_words = _surviving_young_words_base + PADDING_ELEM_NUM;
  64   memset(_surviving_young_words, 0, (size_t) real_length * sizeof(size_t));
  65 
  66   _alloc_buffers[GCAllocForSurvived] = &_surviving_alloc_buffer;
  67   _alloc_buffers[GCAllocForTenured]  = &_tenured_alloc_buffer;
  68 
  69   _start = os::elapsedTime();
  70 }
  71 





  72 void
  73 G1ParScanThreadState::print_termination_stats_hdr(outputStream* const st)
  74 {
  75   st->print_raw_cr("GC Termination Stats");
  76   st->print_raw_cr("     elapsed  --strong roots-- -------termination-------"
  77                    " ------waste (KiB)------");
  78   st->print_raw_cr("thr     ms        ms      %        ms      %    attempts"
  79                    "  total   alloc    undo");
  80   st->print_raw_cr("--- --------- --------- ------ --------- ------ --------"
  81                    " ------- ------- -------");
  82 }
  83 
  84 void
  85 G1ParScanThreadState::print_termination_stats(int i,
  86                                               outputStream* const st) const
  87 {
  88   const double elapsed_ms = elapsed_time() * 1000.0;
  89   const double s_roots_ms = strong_roots_time() * 1000.0;
  90   const double term_ms    = term_time() * 1000.0;
  91   st->print_cr("%3d %9.2f %9.2f %6.2f "


 123   }
 124   return true;
 125 }
 126 
 127 bool G1ParScanThreadState::verify_task(StarTask ref) const {
 128   if (ref.is_narrow()) {
 129     return verify_ref((narrowOop*) ref);
 130   } else {
 131     return verify_ref((oop*) ref);
 132   }
 133 }
 134 #endif // ASSERT
 135 
 136 void G1ParScanThreadState::trim_queue() {
 137   assert(_evac_failure_cl != NULL, "not set");
 138 
 139   StarTask ref;
 140   do {
 141     // Drain the overflow stack first, so other threads can steal.
 142     while (_refs->pop_overflow(ref)) {
 143       deal_with_reference(ref);
 144     }
 145 
 146     while (_refs->pop_local(ref)) {
 147       deal_with_reference(ref);
 148     }
 149   } while (!_refs->is_empty());
 150 }
 151 
 152 void G1ParScanThreadState::steal_and_trim_queue(RefToScanQueueSet *task_queues) {
 153   StarTask stolen_task;
 154   while (task_queues->steal(queue_num(), hash_seed(), stolen_task)) {
 155     assert(verify_task(stolen_task), "sanity");
 156     deal_with_reference(stolen_task);
 157 
 158     // We've just processed a reference and we might have made
 159     // available new entries on the queues. So we have to make sure
 160     // we drain the queues as necessary.
 161     trim_queue();
 162   }
 163 }
 164 
 165 oop G1ParScanThreadState::copy_to_survivor_space(oop const old) {
 166   size_t word_sz = old->size();
 167   HeapRegion* from_region = _g1h->heap_region_containing_raw(old);
 168   // +1 to make the -1 indexes valid...
 169   int       young_index = from_region->young_index_in_cset()+1;
 170   assert( (from_region->is_young() && young_index >  0) ||
 171          (!from_region->is_young() && young_index == 0), "invariant" );
 172   G1CollectorPolicy* g1p = _g1h->g1_policy();
 173   markOop m = old->mark();
 174   int age = m->has_displaced_mark_helper() ? m->displaced_mark_helper()->age()
 175                                            : m->age();
 176   GCAllocPurpose alloc_purpose = g1p->evacuation_destination(from_region, age,
 177                                                              word_sz);
 178   HeapWord* obj_ptr = allocate(alloc_purpose, word_sz);
 179 #ifndef PRODUCT
 180   // Should this evacuation fail?
 181   if (_g1h->evacuation_should_fail()) {
 182     if (obj_ptr != NULL) {
 183       undo_allocation(alloc_purpose, obj_ptr, word_sz);
 184       obj_ptr = NULL;


 298   }
 299 }
 300 
 301 HeapWord* G1ParScanThreadState::allocate(GCAllocPurpose purpose, size_t word_sz) {
 302   HeapWord* obj = alloc_buffer(purpose)->allocate(word_sz);
 303   if (obj != NULL) {
 304     return obj;
 305   }
 306   return allocate_slow(purpose, word_sz);
 307 }
 308 
 309 void G1ParScanThreadState::retire_alloc_buffers() {
 310   for (int ap = 0; ap < GCAllocPurposeCount; ++ap) {
 311     size_t waste = _alloc_buffers[ap]->words_remaining();
 312     add_to_alloc_buffer_waste(waste);
 313     _alloc_buffers[ap]->flush_stats_and_retire(_g1h->stats_for_purpose((GCAllocPurpose)ap),
 314                                                true /* end_of_gc */,
 315                                                false /* retain */);
 316   }
 317 }
 318 
 319 template <class T> void G1ParScanThreadState::do_oop_evac(T* p, HeapRegion* from) {
 320   assert(!oopDesc::is_null(oopDesc::load_decode_heap_oop(p)),
 321          "Reference should not be NULL here as such are never pushed to the task queue.");
 322   oop obj = oopDesc::load_decode_heap_oop_not_null(p);
 323 
 324   // Although we never intentionally push references outside of the collection
 325   // set, due to (benign) races in the claim mechanism during RSet scanning more
 326   // than one thread might claim the same card. So the same card may be
 327   // processed multiple times. So redo this check.
 328   if (_g1h->in_cset_fast_test(obj)) {
 329     oop forwardee;
 330     if (obj->is_forwarded()) {
 331       forwardee = obj->forwardee();
 332     } else {
 333       forwardee = copy_to_survivor_space(obj);
 334     }
 335     assert(forwardee != NULL, "forwardee should not be NULL");
 336     oopDesc::encode_store_heap_oop(p, forwardee);
 337   }
 338 
 339   assert(obj != NULL, "Must be");
 340   update_rs(from, p, queue_num());
 341 }
 342 
 343 inline void G1ParScanThreadState::do_oop_partial_array(oop* p) {
 344   assert(has_partial_array_mask(p), "invariant");
 345   oop from_obj = clear_partial_array_mask(p);
 346 
 347   assert(Universe::heap()->is_in_reserved(from_obj), "must be in heap.");
 348   assert(from_obj->is_objArray(), "must be obj array");
 349   objArrayOop from_obj_array = objArrayOop(from_obj);
 350   // The from-space object contains the real length.
 351   int length                 = from_obj_array->length();
 352 
 353   assert(from_obj->is_forwarded(), "must be forwarded");
 354   oop to_obj                 = from_obj->forwardee();
 355   assert(from_obj != to_obj, "should not be chunking self-forwarded objects");
 356   objArrayOop to_obj_array   = objArrayOop(to_obj);
 357   // We keep track of the next start index in the length field of the
 358   // to-space object.
 359   int next_index             = to_obj_array->length();
 360   assert(0 <= next_index && next_index < length,
 361          err_msg("invariant, next index: %d, length: %d", next_index, length));
 362 
 363   int start                  = next_index;
 364   int end                    = length;
 365   int remainder              = end - start;
 366   // We'll try not to push a range that's smaller than ParGCArrayScanChunk.
 367   if (remainder > 2 * ParGCArrayScanChunk) {
 368     end = start + ParGCArrayScanChunk;
 369     to_obj_array->set_length(end);
 370     // Push the remainder before we process the range in case another
 371     // worker has run out of things to do and can steal it.
 372     oop* from_obj_p = set_partial_array_mask(from_obj);
 373     push_on_queue(from_obj_p);
 374   } else {
 375     assert(length == end, "sanity");
 376     // We'll process the final range for this object. Restore the length
 377     // so that the heap remains parsable in case of evacuation failure.
 378     to_obj_array->set_length(end);
 379   }
 380   _scanner.set_region(_g1h->heap_region_containing_raw(to_obj));
 381   // Process indexes [start,end). It will also process the header
 382   // along with the first chunk (i.e., the chunk with start == 0).
 383   // Note that at this point the length field of to_obj_array is not
 384   // correct given that we are using it to keep track of the next
 385   // start index. oop_iterate_range() (thankfully!) ignores the length
 386   // field and only relies on the start / end parameters.  It does
 387   // however return the size of the object which will be incorrect. So
 388   // we have to ignore it even if we wanted to use it.
 389   to_obj_array->oop_iterate_range(&_scanner, start, end);
 390 }
 391 
 392 template <class T> inline void G1ParScanThreadState::deal_with_reference(T* ref_to_scan) {
 393   if (!has_partial_array_mask(ref_to_scan)) {
 394     // Note: we can use "raw" versions of "region_containing" because
 395     // "obj_to_scan" is definitely in the heap, and is not in a
 396     // humongous region.
 397     HeapRegion* r = _g1h->heap_region_containing_raw(ref_to_scan);
 398     do_oop_evac(ref_to_scan, r);
 399   } else {
 400     do_oop_partial_array((oop*)ref_to_scan);
 401   }
 402 }
 403 
 404 inline void G1ParScanThreadState::deal_with_reference(StarTask ref) {
 405   assert(verify_task(ref), "sanity");
 406   if (ref.is_narrow()) {
 407     deal_with_reference((narrowOop*)ref);
 408   } else {
 409     deal_with_reference((oop*)ref);
 410   }
 411 }


  52   // non-young regions (where the age is -1)
  53   // We also add a few elements at the beginning and at the end in
  54   // an attempt to eliminate cache contention
  55   uint real_length = 1 + _g1h->g1_policy()->young_cset_region_length();
  56   uint array_length = PADDING_ELEM_NUM +
  57                       real_length +
  58                       PADDING_ELEM_NUM;
  59   _surviving_young_words_base = NEW_C_HEAP_ARRAY(size_t, array_length, mtGC);
  60   if (_surviving_young_words_base == NULL)
  61     vm_exit_out_of_memory(array_length * sizeof(size_t), OOM_MALLOC_ERROR,
  62                           "Not enough space for young surv histo.");
  63   _surviving_young_words = _surviving_young_words_base + PADDING_ELEM_NUM;
  64   memset(_surviving_young_words, 0, (size_t) real_length * sizeof(size_t));
  65 
  66   _alloc_buffers[GCAllocForSurvived] = &_surviving_alloc_buffer;
  67   _alloc_buffers[GCAllocForTenured]  = &_tenured_alloc_buffer;
  68 
  69   _start = os::elapsedTime();
  70 }
  71 
  72 G1ParScanThreadState::~G1ParScanThreadState() {
  73   retire_alloc_buffers();
  74   FREE_C_HEAP_ARRAY(size_t, _surviving_young_words_base, mtGC);
  75 }
  76 
  77 void
  78 G1ParScanThreadState::print_termination_stats_hdr(outputStream* const st)
  79 {
  80   st->print_raw_cr("GC Termination Stats");
  81   st->print_raw_cr("     elapsed  --strong roots-- -------termination-------"
  82                    " ------waste (KiB)------");
  83   st->print_raw_cr("thr     ms        ms      %        ms      %    attempts"
  84                    "  total   alloc    undo");
  85   st->print_raw_cr("--- --------- --------- ------ --------- ------ --------"
  86                    " ------- ------- -------");
  87 }
  88 
  89 void
  90 G1ParScanThreadState::print_termination_stats(int i,
  91                                               outputStream* const st) const
  92 {
  93   const double elapsed_ms = elapsed_time() * 1000.0;
  94   const double s_roots_ms = strong_roots_time() * 1000.0;
  95   const double term_ms    = term_time() * 1000.0;
  96   st->print_cr("%3d %9.2f %9.2f %6.2f "


 128   }
 129   return true;
 130 }
 131 
 132 bool G1ParScanThreadState::verify_task(StarTask ref) const {
 133   if (ref.is_narrow()) {
 134     return verify_ref((narrowOop*) ref);
 135   } else {
 136     return verify_ref((oop*) ref);
 137   }
 138 }
 139 #endif // ASSERT
 140 
 141 void G1ParScanThreadState::trim_queue() {
 142   assert(_evac_failure_cl != NULL, "not set");
 143 
 144   StarTask ref;
 145   do {
 146     // Drain the overflow stack first, so other threads can steal.
 147     while (_refs->pop_overflow(ref)) {
 148       dispatch_reference(ref);
 149     }
 150 
 151     while (_refs->pop_local(ref)) {
 152       dispatch_reference(ref);
 153     }
 154   } while (!_refs->is_empty());
 155 }
 156 













 157 oop G1ParScanThreadState::copy_to_survivor_space(oop const old) {
 158   size_t word_sz = old->size();
 159   HeapRegion* from_region = _g1h->heap_region_containing_raw(old);
 160   // +1 to make the -1 indexes valid...
 161   int       young_index = from_region->young_index_in_cset()+1;
 162   assert( (from_region->is_young() && young_index >  0) ||
 163          (!from_region->is_young() && young_index == 0), "invariant" );
 164   G1CollectorPolicy* g1p = _g1h->g1_policy();
 165   markOop m = old->mark();
 166   int age = m->has_displaced_mark_helper() ? m->displaced_mark_helper()->age()
 167                                            : m->age();
 168   GCAllocPurpose alloc_purpose = g1p->evacuation_destination(from_region, age,
 169                                                              word_sz);
 170   HeapWord* obj_ptr = allocate(alloc_purpose, word_sz);
 171 #ifndef PRODUCT
 172   // Should this evacuation fail?
 173   if (_g1h->evacuation_should_fail()) {
 174     if (obj_ptr != NULL) {
 175       undo_allocation(alloc_purpose, obj_ptr, word_sz);
 176       obj_ptr = NULL;


 290   }
 291 }
 292 
 293 HeapWord* G1ParScanThreadState::allocate(GCAllocPurpose purpose, size_t word_sz) {
 294   HeapWord* obj = alloc_buffer(purpose)->allocate(word_sz);
 295   if (obj != NULL) {
 296     return obj;
 297   }
 298   return allocate_slow(purpose, word_sz);
 299 }
 300 
 301 void G1ParScanThreadState::retire_alloc_buffers() {
 302   for (int ap = 0; ap < GCAllocPurposeCount; ++ap) {
 303     size_t waste = _alloc_buffers[ap]->words_remaining();
 304     add_to_alloc_buffer_waste(waste);
 305     _alloc_buffers[ap]->flush_stats_and_retire(_g1h->stats_for_purpose((GCAllocPurpose)ap),
 306                                                true /* end_of_gc */,
 307                                                false /* retain */);
 308   }
 309 }