Mercurial > hg > truffle
diff src/share/vm/memory/modRefBarrierSet.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 | ba764ed4b6f2 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/src/share/vm/memory/modRefBarrierSet.hpp Sat Dec 01 00:00:00 2007 +0000 @@ -0,0 +1,104 @@ +/* + * Copyright 2000-2002 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. + * + */ + +// This kind of "BarrierSet" allows a "CollectedHeap" to detect and +// enumerate ref fields that have been modified (since the last +// enumeration), using a card table. + +class OopClosure; +class Generation; + +class ModRefBarrierSet: public BarrierSet { +public: + // Barriers only on ref writes. + bool has_read_ref_barrier() { return false; } + bool has_read_prim_barrier() { return false; } + bool has_write_ref_barrier() { return true; } + bool has_write_prim_barrier() { return false; } + + bool read_ref_needs_barrier(oop* field) { return false; } + bool read_prim_needs_barrier(HeapWord* field, size_t bytes) { return false; } + virtual bool write_ref_needs_barrier(oop* field, oop new_val) = 0; + bool write_prim_needs_barrier(HeapWord* field, size_t bytes, + juint val1, juint val2) { return false; } + + void write_prim_field(oop obj, size_t offset, size_t bytes, + juint val1, juint val2) {} + + void read_ref_field(oop* field) {} + void read_prim_field(HeapWord* field, size_t bytes) {} +protected: + virtual void write_ref_field_work(oop* field, oop new_val) = 0; +public: + void write_prim_field(HeapWord* field, size_t bytes, + juint val1, juint val2) {} + + bool has_read_ref_array_opt() { return false; } + bool has_read_prim_array_opt() { return false; } + bool has_write_prim_array_opt() { return false; } + + bool has_read_region_opt() { return false; } + + + // These operations should assert false unless the correponding operation + // above returns true. + void read_ref_array(MemRegion mr) { + assert(false, "can't call"); + } + void read_prim_array(MemRegion mr) { + assert(false, "can't call"); + } + void write_prim_array(MemRegion mr) { + assert(false, "can't call"); + } + void read_region(MemRegion mr) { + assert(false, "can't call"); + } + + // Invoke "cl->do_oop" on (the address of) every possibly-modifed + // reference field in objects in "sp". If "clear" is "true", the oops + // are no longer considered possibly modified after application of the + // closure. If' "before_save_marks" is true, oops in objects allocated + // after the last call to "save_marks" on "sp" will not be considered. + virtual void mod_oop_in_space_iterate(Space* sp, OopClosure* cl, + bool clear = false, + bool before_save_marks = false) = 0; + + // Causes all refs in "mr" to be assumed to be modified. + virtual void invalidate(MemRegion mr) = 0; + + // The caller guarantees that "mr" contains no references. (Perhaps it's + // objects have been moved elsewhere.) + virtual void clear(MemRegion mr) = 0; + + // Pass along the argument to the superclass. + ModRefBarrierSet(int max_covered_regions) : + BarrierSet(max_covered_regions) {} + +#ifndef PRODUCT + // Verifies that the given region contains no modified references. + virtual void verify_clean_region(MemRegion mr) = 0; +#endif + +};