jdk8-mips64-public/hotspot: src/share/vm/gc_implementation/g1/heapRegionSeq.hpp@15c5903cf9e1 (annotated)

src/share/vm/gc_implementation/g1/heapRegionSeq.hpp@15c5903cf9e1 (annotated)

src/share/vm/gc_implementation/g1/heapRegionSeq.hpp

Mon, 03 Aug 2009 12:59:30 -0700

author: johnc
date: Mon, 03 Aug 2009 12:59:30 -0700
changeset 1324: 15c5903cf9e1
parent 1279: bd02caa94611
child 1907: c18cbe5936b8
permissions: -rw-r--r--

6865703: G1: Parallelize hot card cache cleanup
Summary: Have the GC worker threads clear the hot card cache in parallel by having each worker thread claim a chunk of the card cache and process the cards in that chunk. The size of the chunks that each thread will claim is determined at VM initialization from the size of the card cache and the number of worker threads.
Reviewed-by: jmasa, tonyp

 /*
  * Copyright 2001-2009 Sun Microsystems, Inc.  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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
  * CA 95054 USA or visit www.sun.com if you need additional information or
  * have any questions.
  *
  */
 class HeapRegion;
 class HeapRegionClosure;
 class HeapRegionSeq: public CHeapObj {
   // _regions is kept sorted by start address order, and no two regions are
   // overlapping.
   GrowableArray<HeapRegion*> _regions;
   // The index in "_regions" at which to start the next allocation search.
   // (For efficiency only; private to obj_allocate after initialization.)
   int _alloc_search_start;
   // Attempts to allocate a block of the (assumed humongous) word_size,
   // starting at the region "ind".
   HeapWord* alloc_obj_from_region_index(int ind, size_t word_size);
   // Currently, we're choosing collection sets in a round-robin fashion,
   // starting here.
   int _next_rr_candidate;
   // The bottom address of the bottom-most region, or else NULL if there
   // are no regions in the sequence.
   char* _seq_bottom;
  public:
   // Initializes "this" to the empty sequence of regions.
   HeapRegionSeq(const size_t max_size);
   // Adds "hr" to "this" sequence.  Requires "hr" not to overlap with
   // any region already in "this".  (Will perform better if regions are
   // inserted in ascending address order.)
   void insert(HeapRegion* hr);
   // Given a HeapRegion*, returns its index within _regions,
   // or returns -1 if not found.
   int find(HeapRegion* hr);
   // Requires the index to be valid, and return the region at the index.
   HeapRegion* at(size_t i) { return _regions.at((int)i); }
   // Return the number of regions in the sequence.
   size_t length();
   // Returns the number of contiguous regions at the end of the sequence
   // that are available for allocation.
   size_t free_suffix();
   // Requires "word_size" to be humongous (in the technical sense).  If
   // possible, allocates a contiguous subsequence of the heap regions to
   // satisfy the allocation, and returns the address of the beginning of
   // that sequence, otherwise returns NULL.
   HeapWord* obj_allocate(size_t word_size);
   // Apply the "doHeapRegion" method of "blk" to all regions in "this",
   // in address order, terminating the iteration early
   // if the "doHeapRegion" method returns "true".
   void iterate(HeapRegionClosure* blk);
   // Apply the "doHeapRegion" method of "blk" to all regions in "this",
   // starting at "r" (or first region, if "r" is NULL), in a circular
   // manner, terminating the iteration early if the "doHeapRegion" method
   // returns "true".
   void iterate_from(HeapRegion* r, HeapRegionClosure* blk);
   // As above, but start from a given index in the sequence
   // instead of a given heap region.
   void iterate_from(int idx, HeapRegionClosure* blk);
   // Requires "shrink_bytes" to be a multiple of the page size and heap
   // region granularity.  Deletes as many "rightmost" completely free heap
   // regions from the sequence as comprise shrink_bytes bytes.  Returns the
   // MemRegion indicating the region those regions comprised, and sets
   // "num_regions_deleted" to the number of regions deleted.
   MemRegion shrink_by(size_t shrink_bytes, size_t& num_regions_deleted);
   // If "addr" falls within a region in the sequence, return that region,
   // or else NULL.
   HeapRegion* addr_to_region(const void* addr);
   void print();
   // Prints out runs of empty regions.
   void print_empty_runs();
 };

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src/share/vm/gc_implementation/g1/heapRegionSeq.hpp@15c5903cf9e1 (annotated)

src/share/vm/gc_implementation/g1/heapRegionSeq.hpp