Mercurial > hg > truffle
view src/share/vm/memory/iterator.hpp @ 690:d142f1feeed5
Merge
author | acorn |
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date | Sun, 29 Mar 2009 18:19:05 -0400 |
parents | 1ee8caae33af |
children | 05f89f00a864 148e5441d916 |
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/* * Copyright 1997-2008 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. * */ // The following classes are C++ `closures` for iterating over objects, roots and spaces class ReferenceProcessor; // Closure provides abortability. class Closure : public StackObj { protected: bool _abort; void set_abort() { _abort = true; } public: Closure() : _abort(false) {} // A subtype can use this mechanism to indicate to some iterator mapping // functions that the iteration should cease. bool abort() { return _abort; } void clear_abort() { _abort = false; } }; // OopClosure is used for iterating through roots (oop*) class OopClosure : public Closure { public: ReferenceProcessor* _ref_processor; OopClosure(ReferenceProcessor* rp) : _ref_processor(rp) { } OopClosure() : _ref_processor(NULL) { } virtual void do_oop(oop* o) = 0; virtual void do_oop_v(oop* o) { do_oop(o); } virtual void do_oop(narrowOop* o) = 0; virtual void do_oop_v(narrowOop* o) { do_oop(o); } // In support of post-processing of weak links of KlassKlass objects; // see KlassKlass::oop_oop_iterate(). virtual const bool should_remember_klasses() const { return false; } virtual void remember_klass(Klass* k) { /* do nothing */ } // If "true", invoke on nmethods (when scanning compiled frames). virtual const bool do_nmethods() const { return false; } // The methods below control how object iterations invoking this closure // should be performed: // If "true", invoke on header klass field. bool do_header() { return true; } // Note that this is non-virtual. // Controls how prefetching is done for invocations of this closure. Prefetch::style prefetch_style() { // Note that this is non-virtual. return Prefetch::do_none; } // True iff this closure may be safely applied more than once to an oop // location without an intervening "major reset" (like the end of a GC). virtual bool idempotent() { return false; } virtual bool apply_to_weak_ref_discovered_field() { return false; } }; // ObjectClosure is used for iterating through an object space class ObjectClosure : public Closure { public: // Called for each object. virtual void do_object(oop obj) = 0; }; class BoolObjectClosure : public ObjectClosure { public: virtual bool do_object_b(oop obj) = 0; }; // Applies an oop closure to all ref fields in objects iterated over in an // object iteration. class ObjectToOopClosure: public ObjectClosure { OopClosure* _cl; public: void do_object(oop obj); ObjectToOopClosure(OopClosure* cl) : _cl(cl) {} }; // A version of ObjectClosure with "memory" (see _previous_address below) class UpwardsObjectClosure: public BoolObjectClosure { HeapWord* _previous_address; public: UpwardsObjectClosure() : _previous_address(NULL) { } void set_previous(HeapWord* addr) { _previous_address = addr; } HeapWord* previous() { return _previous_address; } // A return value of "true" can be used by the caller to decide // if this object's end should *NOT* be recorded in // _previous_address above. virtual bool do_object_bm(oop obj, MemRegion mr) = 0; }; // A version of ObjectClosure that is expected to be robust // in the face of possibly uninitialized objects. class ObjectClosureCareful : public ObjectClosure { public: virtual size_t do_object_careful_m(oop p, MemRegion mr) = 0; virtual size_t do_object_careful(oop p) = 0; }; // The following are used in CompactibleFreeListSpace and // ConcurrentMarkSweepGeneration. // Blk closure (abstract class) class BlkClosure : public StackObj { public: virtual size_t do_blk(HeapWord* addr) = 0; }; // A version of BlkClosure that is expected to be robust // in the face of possibly uninitialized objects. class BlkClosureCareful : public BlkClosure { public: size_t do_blk(HeapWord* addr) { guarantee(false, "call do_blk_careful instead"); return 0; } virtual size_t do_blk_careful(HeapWord* addr) = 0; }; // SpaceClosure is used for iterating over spaces class Space; class CompactibleSpace; class SpaceClosure : public StackObj { public: // Called for each space virtual void do_space(Space* s) = 0; }; class CompactibleSpaceClosure : public StackObj { public: // Called for each compactible space virtual void do_space(CompactibleSpace* s) = 0; }; // MonitorClosure is used for iterating over monitors in the monitors cache class ObjectMonitor; class MonitorClosure : public StackObj { public: // called for each monitor in cache virtual void do_monitor(ObjectMonitor* m) = 0; }; // A closure that is applied without any arguments. class VoidClosure : public StackObj { public: // I would have liked to declare this a pure virtual, but that breaks // in mysterious ways, for unknown reasons. virtual void do_void(); }; // YieldClosure is intended for use by iteration loops // to incrementalize their work, allowing interleaving // of an interruptable task so as to allow other // threads to run (which may not otherwise be able to access // exclusive resources, for instance). Additionally, the // closure also allows for aborting an ongoing iteration // by means of checking the return value from the polling // call. class YieldClosure : public StackObj { public: virtual bool should_return() = 0; }; // Abstract closure for serializing data (read or write). class SerializeOopClosure : public OopClosure { public: // Return bool indicating whether closure implements read or write. virtual bool reading() const = 0; // Read/write the int pointed to by i. virtual void do_int(int* i) = 0; // Read/write the size_t pointed to by i. virtual void do_size_t(size_t* i) = 0; // Read/write the void pointer pointed to by p. virtual void do_ptr(void** p) = 0; // Read/write the HeapWord pointer pointed to be p. virtual void do_ptr(HeapWord** p) = 0; // Read/write the region specified. virtual void do_region(u_char* start, size_t size) = 0; // Check/write the tag. If reading, then compare the tag against // the passed in value and fail is they don't match. This allows // for verification that sections of the serialized data are of the // correct length. virtual void do_tag(int tag) = 0; };