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

 /*

  * Copyright (c) 2001, 2015, 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/g1BiasedArray.hpp"

 #include "gc_implementation/g1/g1RegionToSpaceMapper.hpp"

 #include "memory/allocation.inline.hpp"

 #include "runtime/virtualspace.hpp"

 #include "services/memTracker.hpp"

 #include "utilities/bitMap.inline.hpp"

 G1RegionToSpaceMapper::G1RegionToSpaceMapper(ReservedSpace rs,

                                              size_t used_size,

                                              size_t page_size,

                                              size_t region_granularity,

                                              MemoryType type) :

   _storage(rs, used_size, page_size),

   _region_granularity(region_granularity),

   _listener(NULL),

   _commit_map() {

   guarantee(is_power_of_2(page_size), "must be");

   guarantee(is_power_of_2(region_granularity), "must be");

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

 }

 // G1RegionToSpaceMapper implementation where the region granularity is larger than

 // or the same as the commit granularity.

 // Basically, the space corresponding to one region region spans several OS pages.

 class G1RegionsLargerThanCommitSizeMapper : public G1RegionToSpaceMapper {

  private:

   size_t _pages_per_region;

  public:

   G1RegionsLargerThanCommitSizeMapper(ReservedSpace rs,

                                       size_t actual_size,

                                       size_t page_size,

                                       size_t alloc_granularity,

                                       size_t commit_factor,

                                       MemoryType type) :

     G1RegionToSpaceMapper(rs, actual_size, page_size, alloc_granularity, type),

     _pages_per_region(alloc_granularity / (page_size * commit_factor)) {

     guarantee(alloc_granularity >= page_size, "allocation granularity smaller than commit granularity");

     _commit_map.resize(rs.size() * commit_factor / alloc_granularity, /* in_resource_area */ false);

   }

   virtual void commit_regions(uint start_idx, size_t num_regions) {

     bool zero_filled = _storage.commit((size_t)start_idx * _pages_per_region, num_regions * _pages_per_region);

     _commit_map.set_range(start_idx, start_idx + num_regions);

     fire_on_commit(start_idx, num_regions, zero_filled);

   }

   virtual void uncommit_regions(uint start_idx, size_t num_regions) {

     _storage.uncommit((size_t)start_idx * _pages_per_region, num_regions * _pages_per_region);

     _commit_map.clear_range(start_idx, start_idx + num_regions);

   }

 };

 // G1RegionToSpaceMapper implementation where the region granularity is smaller

 // than the commit granularity.

 // Basically, the contents of one OS page span several regions.

 class G1RegionsSmallerThanCommitSizeMapper : public G1RegionToSpaceMapper {

  private:

   class CommitRefcountArray : public G1BiasedMappedArray<uint> {

    protected:

      virtual uint default_value() const { return 0; }

   };

   size_t _regions_per_page;

   CommitRefcountArray _refcounts;

   uintptr_t region_idx_to_page_idx(uint region) const {

     return region / _regions_per_page;

   }

  public:

   G1RegionsSmallerThanCommitSizeMapper(ReservedSpace rs,

                                        size_t actual_size,

                                        size_t page_size,

                                        size_t alloc_granularity,

                                        size_t commit_factor,

                                        MemoryType type) :

     G1RegionToSpaceMapper(rs, actual_size, page_size, alloc_granularity, type),

     _regions_per_page((page_size * commit_factor) / alloc_granularity), _refcounts() {

     guarantee((page_size * commit_factor) >= alloc_granularity, "allocation granularity smaller than commit granularity");

     _refcounts.initialize((HeapWord*)rs.base(), (HeapWord*)(rs.base() + align_size_up(rs.size(), page_size)), page_size);

     _commit_map.resize(rs.size() * commit_factor / alloc_granularity, /* in_resource_area */ false);

   }

   virtual void commit_regions(uint start_idx, size_t num_regions) {

     for (uint i = start_idx; i < start_idx + num_regions; i++) {

       assert(!_commit_map.at(i), err_msg("Trying to commit storage at region %u that is already committed", i));

       size_t idx = region_idx_to_page_idx(i);

       uint old_refcount = _refcounts.get_by_index(idx);

       bool zero_filled = false;

       if (old_refcount == 0) {

         zero_filled = _storage.commit(idx, 1);

       }

       _refcounts.set_by_index(idx, old_refcount + 1);

       _commit_map.set_bit(i);

       fire_on_commit(i, 1, zero_filled);

     }

   }

   virtual void uncommit_regions(uint start_idx, size_t num_regions) {

     for (uint i = start_idx; i < start_idx + num_regions; i++) {

       assert(_commit_map.at(i), err_msg("Trying to uncommit storage at region %u that is not committed", i));

       size_t idx = region_idx_to_page_idx(i);

       uint old_refcount = _refcounts.get_by_index(idx);

       assert(old_refcount > 0, "must be");

       if (old_refcount == 1) {

         _storage.uncommit(idx, 1);

       }

       _refcounts.set_by_index(idx, old_refcount - 1);

       _commit_map.clear_bit(i);

     }

   }

 };

 void G1RegionToSpaceMapper::fire_on_commit(uint start_idx, size_t num_regions, bool zero_filled) {

   if (_listener != NULL) {

     _listener->on_commit(start_idx, num_regions, zero_filled);

   }

 }

 G1RegionToSpaceMapper* G1RegionToSpaceMapper::create_mapper(ReservedSpace rs,

                                                             size_t actual_size,

                                                             size_t page_size,

                                                             size_t region_granularity,

                                                             size_t commit_factor,

                                                             MemoryType type) {

   if (region_granularity >= (page_size * commit_factor)) {

     return new G1RegionsLargerThanCommitSizeMapper(rs, actual_size, page_size, region_granularity, commit_factor, type);

   } else {

     return new G1RegionsSmallerThanCommitSizeMapper(rs, actual_size, page_size, region_granularity, commit_factor, type);

   }

 }