jdk8-mips64-public/hotspot: src/share/vm/memory/metaspace.hpp@bdfbb1fb19ca (annotated)

src/share/vm/memory/metaspace.hpp@bdfbb1fb19ca (annotated)

src/share/vm/memory/metaspace.hpp

Tue, 15 Oct 2013 14:28:51 +0200

author: stefank
date: Tue, 15 Oct 2013 14:28:51 +0200
changeset 5941: bdfbb1fb19ca
parent 5863: 85c1ca43713f
child 6027: a6177f601c64
permissions: -rw-r--r--

8026391: The Metachunk header wastes memory
Reviewed-by: coleenp, jmasa

 /*
  * Copyright (c) 2011, 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_METASPACE_HPP
 #define SHARE_VM_MEMORY_METASPACE_HPP
 #include "memory/allocation.hpp"
 #include "memory/memRegion.hpp"
 #include "runtime/virtualspace.hpp"
 #include "utilities/exceptions.hpp"
 // Metaspace
 //
 // Metaspaces are Arenas for the VM's metadata.
 // They are allocated one per class loader object, and one for the null
 // bootstrap class loader
 // Eventually for bootstrap loader we'll have a read-only section and read-write
 // to write for DumpSharedSpaces and read for UseSharedSpaces
 //
 //    block X ---+       +-------------------+
 //               |       |  Virtualspace     |
 //               |       |                   |
 //               |       |                   |
 //               |       |-------------------|
 //               |       || Chunk            |
 //               |       ||                  |
 //               |       ||----------        |
 //               +------>||| block 0 |       |
 //                       ||----------        |
 //                       ||| block 1 |       |
 //                       ||----------        |
 //                       ||                  |
 //                       |-------------------|
 //                       |                   |
 //                       |                   |
 //                       +-------------------+
 //
 class ChunkManager;
 class ClassLoaderData;
 class Metablock;
 class Metachunk;
 class MetaWord;
 class Mutex;
 class outputStream;
 class SpaceManager;
 class VirtualSpaceList;
 // Metaspaces each have a  SpaceManager and allocations
 // are done by the SpaceManager.  Allocations are done
 // out of the current Metachunk.  When the current Metachunk
 // is exhausted, the SpaceManager gets a new one from
 // the current VirtualSpace.  When the VirtualSpace is exhausted
 // the SpaceManager gets a new one.  The SpaceManager
 // also manages freelists of available Chunks.
 //
 // Currently the space manager maintains the list of
 // virtual spaces and the list of chunks in use.  Its
 // allocate() method returns a block for use as a
 // quantum of metadata.
 class Metaspace : public CHeapObj<mtClass> {
   friend class VMStructs;
   friend class SpaceManager;
   friend class VM_CollectForMetadataAllocation;
   friend class MetaspaceGC;
   friend class MetaspaceAux;
  public:
   enum MetadataType {
     ClassType,
     NonClassType,
     MetadataTypeCount
   };
   enum MetaspaceType {
     StandardMetaspaceType,
     BootMetaspaceType,
     ROMetaspaceType,
     ReadWriteMetaspaceType,
     AnonymousMetaspaceType,
     ReflectionMetaspaceType
   };
  private:
   void initialize(Mutex* lock, MetaspaceType type);
   // Get the first chunk for a Metaspace.  Used for
   // special cases such as the boot class loader, reflection
   // class loader and anonymous class loader.
   Metachunk* get_initialization_chunk(MetadataType mdtype,
                                       size_t chunk_word_size,
                                       size_t chunk_bunch);
   // Align up the word size to the allocation word size
   static size_t align_word_size_up(size_t);
   // Aligned size of the metaspace.
   static size_t _class_metaspace_size;
   static size_t class_metaspace_size() {
     return _class_metaspace_size;
   }
   static void set_class_metaspace_size(size_t metaspace_size) {
     _class_metaspace_size = metaspace_size;
   }
   static size_t _first_chunk_word_size;
   static size_t _first_class_chunk_word_size;
   static size_t _commit_alignment;
   static size_t _reserve_alignment;
   SpaceManager* _vsm;
   SpaceManager* vsm() const { return _vsm; }
   SpaceManager* _class_vsm;
   SpaceManager* class_vsm() const { return _class_vsm; }
   // Allocate space for metadata of type mdtype. This is space
   // within a Metachunk and is used by
   //   allocate(ClassLoaderData*, size_t, bool, MetadataType, TRAPS)
   MetaWord* allocate(size_t word_size, MetadataType mdtype);
   // Virtual Space lists for both classes and other metadata
   static VirtualSpaceList* _space_list;
   static VirtualSpaceList* _class_space_list;
   static ChunkManager* _chunk_manager_metadata;
   static ChunkManager* _chunk_manager_class;
  public:
   static VirtualSpaceList* space_list()       { return _space_list; }
   static VirtualSpaceList* class_space_list() { return _class_space_list; }
   static VirtualSpaceList* get_space_list(MetadataType mdtype) {
     assert(mdtype != MetadataTypeCount, "MetadaTypeCount can't be used as mdtype");
     return mdtype == ClassType ? class_space_list() : space_list();
   }
   static ChunkManager* chunk_manager_metadata() { return _chunk_manager_metadata; }
   static ChunkManager* chunk_manager_class()    { return _chunk_manager_class; }
   static ChunkManager* get_chunk_manager(MetadataType mdtype) {
     assert(mdtype != MetadataTypeCount, "MetadaTypeCount can't be used as mdtype");
     return mdtype == ClassType ? chunk_manager_class() : chunk_manager_metadata();
   }
  private:
   // This is used by DumpSharedSpaces only, where only _vsm is used. So we will
   // maintain a single list for now.
   void record_allocation(void* ptr, MetaspaceObj::Type type, size_t word_size);
 #ifdef _LP64
   static void set_narrow_klass_base_and_shift(address metaspace_base, address cds_base);
   // Returns true if can use CDS with metaspace allocated as specified address.
   static bool can_use_cds_with_metaspace_addr(char* metaspace_base, address cds_base);
   static void allocate_metaspace_compressed_klass_ptrs(char* requested_addr, address cds_base);
   static void initialize_class_space(ReservedSpace rs);
 #endif
   class AllocRecord : public CHeapObj<mtClass> {
   public:
     AllocRecord(address ptr, MetaspaceObj::Type type, int byte_size)
       : _next(NULL), _ptr(ptr), _type(type), _byte_size(byte_size) {}
     AllocRecord *_next;
     address _ptr;
     MetaspaceObj::Type _type;
     int _byte_size;
   };
   AllocRecord * _alloc_record_head;
   AllocRecord * _alloc_record_tail;
  public:
   Metaspace(Mutex* lock, MetaspaceType type);
   ~Metaspace();
   static void ergo_initialize();
   static void global_initialize();
   static size_t first_chunk_word_size() { return _first_chunk_word_size; }
   static size_t first_class_chunk_word_size() { return _first_class_chunk_word_size; }
   static size_t reserve_alignment()       { return _reserve_alignment; }
   static size_t reserve_alignment_words() { return _reserve_alignment / BytesPerWord; }
   static size_t commit_alignment()        { return _commit_alignment; }
   static size_t commit_alignment_words()  { return _commit_alignment / BytesPerWord; }
   char*  bottom() const;
   size_t used_words_slow(MetadataType mdtype) const;
   size_t free_words_slow(MetadataType mdtype) const;
   size_t capacity_words_slow(MetadataType mdtype) const;
   size_t used_bytes_slow(MetadataType mdtype) const;
   size_t capacity_bytes_slow(MetadataType mdtype) const;
   static MetaWord* allocate(ClassLoaderData* loader_data, size_t word_size,
                             bool read_only, MetaspaceObj::Type type, TRAPS);
   void deallocate(MetaWord* ptr, size_t byte_size, bool is_class);
   MetaWord* expand_and_allocate(size_t size,
                                 MetadataType mdtype);
   static bool contains(const void *ptr);
   void dump(outputStream* const out) const;
   // Free empty virtualspaces
   static void purge(MetadataType mdtype);
   static void purge();
   static void report_metadata_oome(ClassLoaderData* loader_data, size_t word_size,
                                    MetadataType mdtype, TRAPS);
   void print_on(outputStream* st) const;
   // Debugging support
   void verify();
   class AllocRecordClosure :  public StackObj {
   public:
     virtual void doit(address ptr, MetaspaceObj::Type type, int byte_size) = 0;
   };
   void iterate(AllocRecordClosure *closure);
   // Return TRUE only if UseCompressedClassPointers is True and DumpSharedSpaces is False.
   static bool using_class_space() {
     return NOT_LP64(false) LP64_ONLY(UseCompressedClassPointers && !DumpSharedSpaces);
   }
   static bool is_class_space_allocation(MetadataType mdType) {
     return mdType == ClassType && using_class_space();
   }
 };
 class MetaspaceAux : AllStatic {
   static size_t free_chunks_total_words(Metaspace::MetadataType mdtype);
   // These methods iterate over the classloader data graph
   // for the given Metaspace type.  These are slow.
   static size_t used_bytes_slow(Metaspace::MetadataType mdtype);
   static size_t free_bytes_slow(Metaspace::MetadataType mdtype);
   static size_t capacity_bytes_slow(Metaspace::MetadataType mdtype);
   static size_t capacity_bytes_slow();
   // Running sum of space in all Metachunks that has been
   // allocated to a Metaspace.  This is used instead of
   // iterating over all the classloaders. One for each
   // type of Metadata
   static size_t _allocated_capacity_words[Metaspace:: MetadataTypeCount];
   // Running sum of space in all Metachunks that have
   // are being used for metadata. One for each
   // type of Metadata.
   static size_t _allocated_used_words[Metaspace:: MetadataTypeCount];
  public:
   // Decrement and increment _allocated_capacity_words
   static void dec_capacity(Metaspace::MetadataType type, size_t words);
   static void inc_capacity(Metaspace::MetadataType type, size_t words);
   // Decrement and increment _allocated_used_words
   static void dec_used(Metaspace::MetadataType type, size_t words);
   static void inc_used(Metaspace::MetadataType type, size_t words);
   // Total of space allocated to metadata in all Metaspaces.
   // This sums the space used in each Metachunk by
   // iterating over the classloader data graph
   static size_t used_bytes_slow() {
     return used_bytes_slow(Metaspace::ClassType) +
            used_bytes_slow(Metaspace::NonClassType);
   }
   // Used by MetaspaceCounters
   static size_t free_chunks_total_words();
   static size_t free_chunks_total_bytes();
   static size_t free_chunks_total_bytes(Metaspace::MetadataType mdtype);
   static size_t allocated_capacity_words(Metaspace::MetadataType mdtype) {
     return _allocated_capacity_words[mdtype];
   }
   static size_t allocated_capacity_words() {
     return allocated_capacity_words(Metaspace::NonClassType) +
            allocated_capacity_words(Metaspace::ClassType);
   }
   static size_t allocated_capacity_bytes(Metaspace::MetadataType mdtype) {
     return allocated_capacity_words(mdtype) * BytesPerWord;
   }
   static size_t allocated_capacity_bytes() {
     return allocated_capacity_words() * BytesPerWord;
   }
   static size_t allocated_used_words(Metaspace::MetadataType mdtype) {
     return _allocated_used_words[mdtype];
   }
   static size_t allocated_used_words() {
     return allocated_used_words(Metaspace::NonClassType) +
            allocated_used_words(Metaspace::ClassType);
   }
   static size_t allocated_used_bytes(Metaspace::MetadataType mdtype) {
     return allocated_used_words(mdtype) * BytesPerWord;
   }
   static size_t allocated_used_bytes() {
     return allocated_used_words() * BytesPerWord;
   }
   static size_t free_bytes();
   static size_t free_bytes(Metaspace::MetadataType mdtype);
   static size_t reserved_bytes(Metaspace::MetadataType mdtype);
   static size_t reserved_bytes() {
     return reserved_bytes(Metaspace::ClassType) +
            reserved_bytes(Metaspace::NonClassType);
   }
   static size_t committed_bytes(Metaspace::MetadataType mdtype);
   static size_t committed_bytes() {
     return committed_bytes(Metaspace::ClassType) +
            committed_bytes(Metaspace::NonClassType);
   }
   static size_t min_chunk_size_words();
   static size_t min_chunk_size_bytes() {
     return min_chunk_size_words() * BytesPerWord;
   }
   // Print change in used metadata.
   static void print_metaspace_change(size_t prev_metadata_used);
   static void print_on(outputStream * out);
   static void print_on(outputStream * out, Metaspace::MetadataType mdtype);
   static void print_class_waste(outputStream* out);
   static void print_waste(outputStream* out);
   static void dump(outputStream* out);
   static void verify_free_chunks();
   // Checks that the values returned by allocated_capacity_bytes() and
   // capacity_bytes_slow() are the same.
   static void verify_capacity();
   static void verify_used();
   static void verify_metrics();
 };
 // Metaspace are deallocated when their class loader are GC'ed.
 // This class implements a policy for inducing GC's to recover
 // Metaspaces.
 class MetaspaceGC : AllStatic {
   // The current high-water-mark for inducing a GC.
   // When committed memory of all metaspaces reaches this value,
   // a GC is induced and the value is increased. Size is in bytes.
   static volatile intptr_t _capacity_until_GC;
   // For a CMS collection, signal that a concurrent collection should
   // be started.
   static bool _should_concurrent_collect;
   static uint _shrink_factor;
   static size_t shrink_factor() { return _shrink_factor; }
   void set_shrink_factor(uint v) { _shrink_factor = v; }
  public:
   static void initialize() { _capacity_until_GC = MetaspaceSize; }
   static size_t capacity_until_GC();
   static size_t inc_capacity_until_GC(size_t v);
   static size_t dec_capacity_until_GC(size_t v);
   static bool should_concurrent_collect() { return _should_concurrent_collect; }
   static void set_should_concurrent_collect(bool v) {
     _should_concurrent_collect = v;
   }
   // The amount to increase the high-water-mark (_capacity_until_GC)
   static size_t delta_capacity_until_GC(size_t bytes);
   // Tells if we have can expand metaspace without hitting set limits.
   static bool can_expand(size_t words, bool is_class);
   // Returns amount that we can expand without hitting a GC,
   // measured in words.
   static size_t allowed_expansion();
   // Calculate the new high-water mark at which to induce
   // a GC.
   static void compute_new_size();
 };
 #endif // SHARE_VM_MEMORY_METASPACE_HPP

Mercurial > jdk8-mips64-public > hotspot / annotate

src/share/vm/memory/metaspace.hpp@bdfbb1fb19ca (annotated)

src/share/vm/memory/metaspace.hpp