Mercurial > jdk8-mips64-public > hotspot / file revision

 /*

  * Copyright (c) 2013, 2014, Oracle and/or its affiliates. All rights reserved.

  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

  *

  * This code is free software; you can redistribute it and/or modify it

  * under the terms of the GNU General Public License version 2 only, as

  * published by the Free Software Foundation.

  *

  * This code is distributed in the hope that it will be useful, but WITHOUT

  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

  * version 2 for more details (a copy is included in the LICENSE file that

  * accompanied this code).

  *

  * You should have received a copy of the GNU General Public License version

  * 2 along with this work; if not, write to the Free Software Foundation,

  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

  *

  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

  * or visit www.oracle.com if you need additional information or have any

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  */

 #include "precompiled.hpp"

 #include "gc_implementation/g1/g1CardCounts.hpp"

 #include "gc_implementation/g1/g1CollectedHeap.inline.hpp"

 #include "gc_implementation/g1/g1CollectorPolicy.hpp"

 #include "gc_implementation/g1/g1GCPhaseTimes.hpp"

 #include "memory/cardTableModRefBS.hpp"

 #include "services/memTracker.hpp"

 #include "utilities/copy.hpp"

 PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC

 void G1CardCounts::clear_range(size_t from_card_num, size_t to_card_num) {

   if (has_count_table()) {

     assert(from_card_num >= 0 && from_card_num < _committed_max_card_num,

            err_msg("from card num out of range: "SIZE_FORMAT, from_card_num));

     assert(from_card_num < to_card_num,

            err_msg("Wrong order? from: " SIZE_FORMAT ", to: "SIZE_FORMAT,

                    from_card_num, to_card_num));

     assert(to_card_num <= _committed_max_card_num,

            err_msg("to card num out of range: "

                    "to: "SIZE_FORMAT ", "

                    "max: "SIZE_FORMAT,

                    to_card_num, _committed_max_card_num));

     to_card_num = MIN2(_committed_max_card_num, to_card_num);

     Copy::fill_to_bytes(&_card_counts[from_card_num], (to_card_num - from_card_num));

   }

 }

 G1CardCounts::G1CardCounts(G1CollectedHeap *g1h):

   _g1h(g1h), _card_counts(NULL),

   _reserved_max_card_num(0), _committed_max_card_num(0),

   _committed_size(0) {}

 void G1CardCounts::initialize() {

   assert(_g1h->max_capacity() > 0, "initialization order");

   assert(_g1h->capacity() == 0, "initialization order");

   if (G1ConcRSHotCardLimit > 0) {

     // The max value we can store in the counts table is

     // max_jubyte. Guarantee the value of the hot

     // threshold limit is no more than this.

     guarantee(G1ConcRSHotCardLimit <= max_jubyte, "sanity");

     _ct_bs = _g1h->g1_barrier_set();

     _ct_bot = _ct_bs->byte_for_const(_g1h->reserved_region().start());

     // Allocate/Reserve the counts table

     size_t reserved_bytes = _g1h->max_capacity();

     _reserved_max_card_num = reserved_bytes >> CardTableModRefBS::card_shift;

     size_t reserved_size = _reserved_max_card_num * sizeof(jbyte);

     ReservedSpace rs(ReservedSpace::allocation_align_size_up(reserved_size));

     if (!rs.is_reserved()) {

       warning("Could not reserve enough space for the card counts table");

       guarantee(!has_reserved_count_table(), "should be NULL");

       return;

     }

     MemTracker::record_virtual_memory_type((address)rs.base(), mtGC);

     _card_counts_storage.initialize(rs, 0);

     _card_counts = (jubyte*) _card_counts_storage.low();

   }

 }

 void G1CardCounts::resize(size_t heap_capacity) {

   // Expand the card counts table to handle a heap with the given capacity.

   if (!has_reserved_count_table()) {

     // Don't expand if we failed to reserve the card counts table.

     return;

   }

   assert(_committed_size ==

          ReservedSpace::allocation_align_size_up(_committed_size),

          err_msg("Unaligned? committed_size: " SIZE_FORMAT, _committed_size));

   // Verify that the committed space for the card counts matches our

   // committed max card num. Note for some allocation alignments, the

   // amount of space actually committed for the counts table will be able

   // to span more cards than the number spanned by the maximum heap.

   size_t prev_committed_size = _committed_size;

   size_t prev_committed_card_num = committed_to_card_num(prev_committed_size);

   assert(prev_committed_card_num == _committed_max_card_num,

          err_msg("Card mismatch: "

                  "prev: " SIZE_FORMAT ", "

                  "committed: "SIZE_FORMAT", "

                  "reserved: "SIZE_FORMAT,

                  prev_committed_card_num, _committed_max_card_num, _reserved_max_card_num));

   size_t new_size = (heap_capacity >> CardTableModRefBS::card_shift) * sizeof(jbyte);

   size_t new_committed_size = ReservedSpace::allocation_align_size_up(new_size);

   size_t new_committed_card_num = committed_to_card_num(new_committed_size);

   if (_committed_max_card_num < new_committed_card_num) {

     // we need to expand the backing store for the card counts

     size_t expand_size = new_committed_size - prev_committed_size;

     if (!_card_counts_storage.expand_by(expand_size)) {

       warning("Card counts table backing store commit failure");

       return;

     }

     assert(_card_counts_storage.committed_size() == new_committed_size,

            "expansion commit failure");

     _committed_size = new_committed_size;

     _committed_max_card_num = new_committed_card_num;

     clear_range(prev_committed_card_num, _committed_max_card_num);

   }

 }

 uint G1CardCounts::add_card_count(jbyte* card_ptr) {

   // Returns the number of times the card has been refined.

   // If we failed to reserve/commit the counts table, return 0.

   // If card_ptr is beyond the committed end of the counts table,

   // return 0.

   // Otherwise return the actual count.

   // Unless G1ConcRSHotCardLimit has been set appropriately,

   // returning 0 will result in the card being considered

   // cold and will be refined immediately.

   uint count = 0;

   if (has_count_table()) {

     size_t card_num = ptr_2_card_num(card_ptr);

     if (card_num < _committed_max_card_num) {

       count = (uint) _card_counts[card_num];

       if (count < G1ConcRSHotCardLimit) {

         _card_counts[card_num] =

           (jubyte)(MIN2((uintx)(_card_counts[card_num] + 1), G1ConcRSHotCardLimit));

       }

     }

   }

   return count;

 }

 bool G1CardCounts::is_hot(uint count) {

   return (count >= G1ConcRSHotCardLimit);

 }

 void G1CardCounts::clear_region(HeapRegion* hr) {

   assert(!hr->isHumongous(), "Should have been cleared");

   if (has_count_table()) {

     HeapWord* bottom = hr->bottom();

     // We use the last address in hr as hr could be the

     // last region in the heap. In which case trying to find

     // the card for hr->end() will be an OOB accesss to the

     // card table.

     HeapWord* last = hr->end() - 1;

     assert(_g1h->g1_committed().contains(last),

            err_msg("last not in committed: "

                    "last: " PTR_FORMAT ", "

                    "committed: [" PTR_FORMAT ", " PTR_FORMAT ")",

                    last,

                    _g1h->g1_committed().start(),

                    _g1h->g1_committed().end()));

     const jbyte* from_card_ptr = _ct_bs->byte_for_const(bottom);

     const jbyte* last_card_ptr = _ct_bs->byte_for_const(last);

 #ifdef ASSERT

     HeapWord* start_addr = _ct_bs->addr_for(from_card_ptr);

     assert(start_addr == hr->bottom(), "alignment");

     HeapWord* last_addr = _ct_bs->addr_for(last_card_ptr);

     assert((last_addr + CardTableModRefBS::card_size_in_words) == hr->end(), "alignment");

 #endif // ASSERT

     // Clear the counts for the (exclusive) card range.

     size_t from_card_num = ptr_2_card_num(from_card_ptr);

     size_t to_card_num = ptr_2_card_num(last_card_ptr) + 1;

     clear_range(from_card_num, to_card_num);

   }

 }

 void G1CardCounts::clear_all() {

   assert(SafepointSynchronize::is_at_safepoint(), "don't call this otherwise");

   clear_range((size_t)0, _committed_max_card_num);

 }

 G1CardCounts::~G1CardCounts() {

   if (has_reserved_count_table()) {

     _card_counts_storage.release();

   }

 }