1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/src/share/vm/memory/iterator.hpp Sat Dec 01 00:00:00 2007 +0000
1.3 @@ -0,0 +1,200 @@
1.4 +/*
1.5 + * Copyright 1997-2006 Sun Microsystems, Inc. All Rights Reserved.
1.6 + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
1.7 + *
1.8 + * This code is free software; you can redistribute it and/or modify it
1.9 + * under the terms of the GNU General Public License version 2 only, as
1.10 + * published by the Free Software Foundation.
1.11 + *
1.12 + * This code is distributed in the hope that it will be useful, but WITHOUT
1.13 + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
1.14 + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
1.15 + * version 2 for more details (a copy is included in the LICENSE file that
1.16 + * accompanied this code).
1.17 + *
1.18 + * You should have received a copy of the GNU General Public License version
1.19 + * 2 along with this work; if not, write to the Free Software Foundation,
1.20 + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
1.21 + *
1.22 + * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
1.23 + * CA 95054 USA or visit www.sun.com if you need additional information or
1.24 + * have any questions.
1.25 + *
1.26 + */
1.27 +
1.28 +// The following classes are C++ `closures` for iterating over objects, roots and spaces
1.29 +
1.30 +class ReferenceProcessor;
1.31 +
1.32 +// OopClosure is used for iterating through roots (oop*)
1.33 +
1.34 +class OopClosure : public StackObj {
1.35 + public:
1.36 + ReferenceProcessor* _ref_processor;
1.37 + OopClosure(ReferenceProcessor* rp) : _ref_processor(rp) { }
1.38 + OopClosure() : _ref_processor(NULL) { }
1.39 + virtual void do_oop(oop* o) = 0;
1.40 + virtual void do_oop_v(oop* o) { do_oop(o); }
1.41 +
1.42 + // In support of post-processing of weak links of KlassKlass objects;
1.43 + // see KlassKlass::oop_oop_iterate().
1.44 + virtual const bool should_remember_klasses() const { return false; }
1.45 + virtual void remember_klass(Klass* k) { /* do nothing */ }
1.46 +
1.47 + // If "true", invoke on nmethods (when scanning compiled frames).
1.48 + virtual const bool do_nmethods() const { return false; }
1.49 +
1.50 + // The methods below control how object iterations invoking this closure
1.51 + // should be performed:
1.52 +
1.53 + // If "true", invoke on header klass field.
1.54 + bool do_header() { return true; } // Note that this is non-virtual.
1.55 + // Controls how prefetching is done for invocations of this closure.
1.56 + Prefetch::style prefetch_style() { // Note that this is non-virtual.
1.57 + return Prefetch::do_none;
1.58 + }
1.59 +};
1.60 +
1.61 +// ObjectClosure is used for iterating through an object space
1.62 +
1.63 +class ObjectClosure : public StackObj {
1.64 + public:
1.65 + // Called for each object.
1.66 + virtual void do_object(oop obj) = 0;
1.67 +};
1.68 +
1.69 +
1.70 +class BoolObjectClosure : public ObjectClosure {
1.71 + public:
1.72 + virtual bool do_object_b(oop obj) = 0;
1.73 +};
1.74 +
1.75 +// Applies an oop closure to all ref fields in objects iterated over in an
1.76 +// object iteration.
1.77 +class ObjectToOopClosure: public ObjectClosure {
1.78 + OopClosure* _cl;
1.79 +public:
1.80 + void do_object(oop obj);
1.81 + ObjectToOopClosure(OopClosure* cl) : _cl(cl) {}
1.82 +};
1.83 +
1.84 +// A version of ObjectClosure with "memory" (see _previous_address below)
1.85 +class UpwardsObjectClosure: public BoolObjectClosure {
1.86 + HeapWord* _previous_address;
1.87 + public:
1.88 + UpwardsObjectClosure() : _previous_address(NULL) { }
1.89 + void set_previous(HeapWord* addr) { _previous_address = addr; }
1.90 + HeapWord* previous() { return _previous_address; }
1.91 + // A return value of "true" can be used by the caller to decide
1.92 + // if this object's end should *NOT* be recorded in
1.93 + // _previous_address above.
1.94 + virtual bool do_object_bm(oop obj, MemRegion mr) = 0;
1.95 +};
1.96 +
1.97 +// A version of ObjectClosure that is expected to be robust
1.98 +// in the face of possibly uninitialized objects.
1.99 +class ObjectClosureCareful : public ObjectClosure {
1.100 + public:
1.101 + virtual size_t do_object_careful_m(oop p, MemRegion mr) = 0;
1.102 + virtual size_t do_object_careful(oop p) = 0;
1.103 +};
1.104 +
1.105 +// The following are used in CompactibleFreeListSpace and
1.106 +// ConcurrentMarkSweepGeneration.
1.107 +
1.108 +// Blk closure (abstract class)
1.109 +class BlkClosure : public StackObj {
1.110 + public:
1.111 + virtual size_t do_blk(HeapWord* addr) = 0;
1.112 +};
1.113 +
1.114 +// A version of BlkClosure that is expected to be robust
1.115 +// in the face of possibly uninitialized objects.
1.116 +class BlkClosureCareful : public BlkClosure {
1.117 + public:
1.118 + size_t do_blk(HeapWord* addr) {
1.119 + guarantee(false, "call do_blk_careful instead");
1.120 + return 0;
1.121 + }
1.122 + virtual size_t do_blk_careful(HeapWord* addr) = 0;
1.123 +};
1.124 +
1.125 +// SpaceClosure is used for iterating over spaces
1.126 +
1.127 +class Space;
1.128 +class CompactibleSpace;
1.129 +
1.130 +class SpaceClosure : public StackObj {
1.131 + public:
1.132 + // Called for each space
1.133 + virtual void do_space(Space* s) = 0;
1.134 +};
1.135 +
1.136 +class CompactibleSpaceClosure : public StackObj {
1.137 + public:
1.138 + // Called for each compactible space
1.139 + virtual void do_space(CompactibleSpace* s) = 0;
1.140 +};
1.141 +
1.142 +
1.143 +
1.144 +// MonitorClosure is used for iterating over monitors in the monitors cache
1.145 +
1.146 +class ObjectMonitor;
1.147 +
1.148 +class MonitorClosure : public StackObj {
1.149 + public:
1.150 + // called for each monitor in cache
1.151 + virtual void do_monitor(ObjectMonitor* m) = 0;
1.152 +};
1.153 +
1.154 +// A closure that is applied without any arguments.
1.155 +class VoidClosure : public StackObj {
1.156 + public:
1.157 + // I would have liked to declare this a pure virtual, but that breaks
1.158 + // in mysterious ways, for unknown reasons.
1.159 + virtual void do_void();
1.160 +};
1.161 +
1.162 +
1.163 +// YieldClosure is intended for use by iteration loops
1.164 +// to incrementalize their work, allowing interleaving
1.165 +// of an interruptable task so as to allow other
1.166 +// threads to run (which may not otherwise be able to access
1.167 +// exclusive resources, for instance). Additionally, the
1.168 +// closure also allows for aborting an ongoing iteration
1.169 +// by means of checking the return value from the polling
1.170 +// call.
1.171 +class YieldClosure : public StackObj {
1.172 + public:
1.173 + virtual bool should_return() = 0;
1.174 +};
1.175 +
1.176 +// Abstract closure for serializing data (read or write).
1.177 +
1.178 +class SerializeOopClosure : public OopClosure {
1.179 +public:
1.180 + // Return bool indicating whether closure implements read or write.
1.181 + virtual bool reading() const = 0;
1.182 +
1.183 + // Read/write the int pointed to by i.
1.184 + virtual void do_int(int* i) = 0;
1.185 +
1.186 + // Read/write the size_t pointed to by i.
1.187 + virtual void do_size_t(size_t* i) = 0;
1.188 +
1.189 + // Read/write the void pointer pointed to by p.
1.190 + virtual void do_ptr(void** p) = 0;
1.191 +
1.192 + // Read/write the HeapWord pointer pointed to be p.
1.193 + virtual void do_ptr(HeapWord** p) = 0;
1.194 +
1.195 + // Read/write the region specified.
1.196 + virtual void do_region(u_char* start, size_t size) = 0;
1.197 +
1.198 + // Check/write the tag. If reading, then compare the tag against
1.199 + // the passed in value and fail is they don't match. This allows
1.200 + // for verification that sections of the serialized data are of the
1.201 + // correct length.
1.202 + virtual void do_tag(int tag) = 0;
1.203 +};
