Mercurial > hg > truffle
diff src/share/vm/gc_implementation/g1/heapRegionSeq.hpp @ 342:37f87013dfd8
6711316: Open source the Garbage-First garbage collector
Summary: First mercurial integration of the code for the Garbage-First garbage collector.
Reviewed-by: apetrusenko, iveresov, jmasa, sgoldman, tonyp, ysr
author | ysr |
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date | Thu, 05 Jun 2008 15:57:56 -0700 |
parents | |
children | 078b8a0d8d7c |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/src/share/vm/gc_implementation/g1/heapRegionSeq.hpp Thu Jun 05 15:57:56 2008 -0700 @@ -0,0 +1,111 @@ +/* + * Copyright 2001-2007 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(); + + // 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. If the arg is "true" reserved + // (popular regions are considered "empty". + void print_empty_runs(bool reserved_are_empty); + +};