Mercurial > hg > graal-compiler
view src/share/vm/memory/iterator.hpp @ 21826:41c3c456e326 jdk8u45-b01
Merge
author | asaha |
---|---|
date | Fri, 12 Dec 2014 14:39:40 -0800 |
parents | 2c6ef90f030a |
children | 7848fc12602b |
line wrap: on
line source
/* * Copyright (c) 1997, 2013, Oracle and/or its affiliates. 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. * */ #ifndef SHARE_VM_MEMORY_ITERATOR_HPP #define SHARE_VM_MEMORY_ITERATOR_HPP #include "memory/allocation.hpp" #include "memory/memRegion.hpp" #include "runtime/prefetch.hpp" #include "utilities/top.hpp" // The following classes are C++ `closures` for iterating over objects, roots and spaces class CodeBlob; class nmethod; class ReferenceProcessor; class DataLayout; class KlassClosure; class ClassLoaderData; // 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 references to Java objects. class OopClosure : public Closure { public: 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); } }; // ExtendedOopClosure adds extra code to be run during oop iterations. // This is needed by the GC and is extracted to a separate type to not // pollute the OopClosure interface. class ExtendedOopClosure : public OopClosure { public: ReferenceProcessor* _ref_processor; ExtendedOopClosure(ReferenceProcessor* rp) : _ref_processor(rp) { } ExtendedOopClosure() : OopClosure(), _ref_processor(NULL) { } // If the do_metadata functions return "true", // we invoke the following when running oop_iterate(): // // 1) do_klass on the header klass pointer. // 2) do_klass on the klass pointer in the mirrors. // 3) do_class_loader_data on the class loader data in class loaders. // // The virtual (without suffix) and the non-virtual (with _nv suffix) need // to be updated together, or else the devirtualization will break. // // Providing default implementations of the _nv functions unfortunately // removes the compile-time safeness, but reduces the clutter for the // ExtendedOopClosures that don't need to walk the metadata. // Currently, only CMS and G1 need these. virtual bool do_metadata() { return do_metadata_nv(); } bool do_metadata_v() { return do_metadata(); } bool do_metadata_nv() { return false; } virtual void do_klass(Klass* k) { do_klass_nv(k); } void do_klass_v(Klass* k) { do_klass(k); } void do_klass_nv(Klass* k) { ShouldNotReachHere(); } virtual void do_class_loader_data(ClassLoaderData* cld) { ShouldNotReachHere(); } // 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; } }; // Wrapper closure only used to implement oop_iterate_no_header(). class NoHeaderExtendedOopClosure : public ExtendedOopClosure { OopClosure* _wrapped_closure; public: NoHeaderExtendedOopClosure(OopClosure* cl) : _wrapped_closure(cl) {} // Warning: this calls the virtual version do_oop in the the wrapped closure. void do_oop_nv(oop* p) { _wrapped_closure->do_oop(p); } void do_oop_nv(narrowOop* p) { _wrapped_closure->do_oop(p); } void do_oop(oop* p) { assert(false, "Only the _nv versions should be used"); _wrapped_closure->do_oop(p); } void do_oop(narrowOop* p) { assert(false, "Only the _nv versions should be used"); _wrapped_closure->do_oop(p);} }; class KlassClosure : public Closure { public: virtual void do_klass(Klass* k) = 0; }; class CLDClosure : public Closure { public: virtual void do_cld(ClassLoaderData* cld) = 0; }; class KlassToOopClosure : public KlassClosure { friend class MetadataAwareOopClosure; friend class MetadataAwareOopsInGenClosure; OopClosure* _oop_closure; // Used when _oop_closure couldn't be set in an initialization list. void initialize(OopClosure* oop_closure) { assert(_oop_closure == NULL, "Should only be called once"); _oop_closure = oop_closure; } public: KlassToOopClosure(OopClosure* oop_closure = NULL) : _oop_closure(oop_closure) {} virtual void do_klass(Klass* k); }; class CLDToOopClosure : public CLDClosure { OopClosure* _oop_closure; KlassToOopClosure _klass_closure; bool _must_claim_cld; public: CLDToOopClosure(OopClosure* oop_closure, bool must_claim_cld = true) : _oop_closure(oop_closure), _klass_closure(oop_closure), _must_claim_cld(must_claim_cld) {} void do_cld(ClassLoaderData* cld); }; class CLDToKlassAndOopClosure : public CLDClosure { friend class SharedHeap; friend class G1CollectedHeap; protected: OopClosure* _oop_closure; KlassClosure* _klass_closure; bool _must_claim_cld; public: CLDToKlassAndOopClosure(KlassClosure* klass_closure, OopClosure* oop_closure, bool must_claim_cld) : _oop_closure(oop_closure), _klass_closure(klass_closure), _must_claim_cld(must_claim_cld) {} void do_cld(ClassLoaderData* cld); }; // The base class for all concurrent marking closures, // that participates in class unloading. // It's used to proxy through the metadata to the oops defined in them. class MetadataAwareOopClosure: public ExtendedOopClosure { KlassToOopClosure _klass_closure; public: MetadataAwareOopClosure() : ExtendedOopClosure() { _klass_closure.initialize(this); } MetadataAwareOopClosure(ReferenceProcessor* rp) : ExtendedOopClosure(rp) { _klass_closure.initialize(this); } virtual bool do_metadata() { return do_metadata_nv(); } inline bool do_metadata_nv() { return true; } virtual void do_klass(Klass* k); void do_klass_nv(Klass* k); virtual void do_class_loader_data(ClassLoaderData* cld); }; // 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 Closure { 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 { ExtendedOopClosure* _cl; public: void do_object(oop obj); ObjectToOopClosure(ExtendedOopClosure* cl) : _cl(cl) {} }; // 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; }; // CodeBlobClosure is used for iterating through code blobs // in the code cache or on thread stacks class CodeBlobClosure : public Closure { public: // Called for each code blob. virtual void do_code_blob(CodeBlob* cb) = 0; }; // Applies an oop closure to all ref fields in code blobs // iterated over in an object iteration. class CodeBlobToOopClosure : public CodeBlobClosure { OopClosure* _cl; bool _fix_relocations; protected: void do_nmethod(nmethod* nm); public: CodeBlobToOopClosure(OopClosure* cl, bool fix_relocations) : _cl(cl), _fix_relocations(fix_relocations) {} virtual void do_code_blob(CodeBlob* cb); const static bool FixRelocations = true; }; class MarkingCodeBlobClosure : public CodeBlobToOopClosure { public: MarkingCodeBlobClosure(OopClosure* cl, bool fix_relocations) : CodeBlobToOopClosure(cl, fix_relocations) {} // Called for each code blob, but at most once per unique blob. virtual void do_code_blob(CodeBlob* cb); class MarkScope : public StackObj { protected: bool _active; public: MarkScope(bool activate = true); // = { if (active) nmethod::oops_do_marking_prologue(); } ~MarkScope(); // = { if (active) nmethod::oops_do_marking_epilogue(); } }; }; // 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 SerializeClosure : public Closure { public: // Return bool indicating whether closure implements read or write. virtual bool reading() const = 0; // Read/write the void pointer pointed to by p. virtual void do_ptr(void** 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; }; class SymbolClosure : public StackObj { public: virtual void do_symbol(Symbol**) = 0; // Clear LSB in symbol address; it can be set by CPSlot. static Symbol* load_symbol(Symbol** p) { return (Symbol*)(intptr_t(*p) & ~1); } // Store symbol, adjusting new pointer if the original pointer was adjusted // (symbol references in constant pool slots have their LSB set to 1). static void store_symbol(Symbol** p, Symbol* sym) { *p = (Symbol*)(intptr_t(sym) | (intptr_t(*p) & 1)); } }; // Helper defines for ExtendOopClosure #define if_do_metadata_checked(closure, nv_suffix) \ /* Make sure the non-virtual and the virtual versions match. */ \ assert(closure->do_metadata##nv_suffix() == closure->do_metadata(), \ "Inconsistency in do_metadata"); \ if (closure->do_metadata##nv_suffix()) #define assert_should_ignore_metadata(closure, nv_suffix) \ assert(!closure->do_metadata##nv_suffix(), "Code to handle metadata is not implemented") #endif // SHARE_VM_MEMORY_ITERATOR_HPP