Mercurial > hg > truffle
diff src/share/vm/memory/genRemSet.hpp @ 0:a61af66fc99e jdk7-b24
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author | duke |
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date | Sat, 01 Dec 2007 00:00:00 +0000 |
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children | 73e96e5c30df |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/src/share/vm/memory/genRemSet.hpp Sat Dec 01 00:00:00 2007 +0000 @@ -0,0 +1,121 @@ +/* + * Copyright 2001-2006 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. + * + */ + +// A GenRemSet provides ways of iterating over pointers accross generations. +// (This is especially useful for older-to-younger.) + +class Generation; +class BarrierSet; +class OopsInGenClosure; +class CardTableRS; + +class GenRemSet: public CHeapObj { + friend class Generation; + + BarrierSet* _bs; + +public: + enum Name { + CardTable, + Other + }; + + GenRemSet(BarrierSet * bs) : _bs(bs) {} + + virtual Name rs_kind() = 0; + + // These are for dynamic downcasts. Unfortunately that it names the + // possible subtypes (but not that they are subtypes!) Return NULL if + // the cast is invalide. + virtual CardTableRS* as_CardTableRS() { return NULL; } + + // Return the barrier set associated with "this." + BarrierSet* bs() { return _bs; } + + // Do any (sequential) processing necessary to prepare for (possibly + // "parallel", if that arg is true) calls to younger_refs_iterate. + virtual void prepare_for_younger_refs_iterate(bool parallel) = 0; + + // Apply the "do_oop" method of "blk" to (exactly) all oop locations + // 1) that are in objects allocated in "g" at the time of the last call + // to "save_Marks", and + // 2) that point to objects in younger generations. + virtual void younger_refs_iterate(Generation* g, OopsInGenClosure* blk) = 0; + + virtual void younger_refs_in_space_iterate(Space* sp, + OopsInGenClosure* cl) = 0; + + // This method is used to notify the remembered set that "new_val" has + // been written into "field" by the garbage collector. + void write_ref_field_gc(oop* field, oop new_val); +protected: + virtual void write_ref_field_gc_work(oop* field, oop new_val) = 0; +public: + + // A version of the above suitable for use by parallel collectors. + virtual void write_ref_field_gc_par(oop* field, oop new_val) = 0; + + // Resize one of the regions covered by the remembered set. + virtual void resize_covered_region(MemRegion new_region) = 0; + + // If the rem set imposes any alignment restrictions on boundaries + // within the heap, this function tells whether they are met. + virtual bool is_aligned(HeapWord* addr) = 0; + + // If the RS (or BS) imposes an aligment constraint on maximum heap size. + // (This must be static, and dispatch on "nm", because it is called + // before an RS is created.) + static uintx max_alignment_constraint(Name nm); + + virtual void verify() = 0; + + // Verify that the remembered set has no entries for + // the heap interval denoted by mr. + virtual void verify_empty(MemRegion mr) = 0; + + // If appropriate, print some information about the remset on "tty". + virtual void print() {} + + // Informs the RS that the given memregion contains no references to + // younger generations. + virtual void clear(MemRegion mr) = 0; + + // Informs the RS that there are no references to generations + // younger than gen from generations gen and older. + // The parameter clear_perm indicates if the perm_gen's + // remembered set should also be processed/cleared. + virtual void clear_into_younger(Generation* gen, bool clear_perm) = 0; + + // Informs the RS that refs in the given "mr" may have changed + // arbitrarily, and therefore may contain old-to-young pointers. + virtual void invalidate(MemRegion mr) = 0; + + // Informs the RS that refs in this generation + // may have changed arbitrarily, and therefore may contain + // old-to-young pointers in arbitrary locations. The parameter + // younger indicates if the same should be done for younger generations + // as well. The parameter perm indicates if the same should be done for + // perm gen as well. + virtual void invalidate_or_clear(Generation* gen, bool younger, bool perm) = 0; +};