/* * Copyright (c) 2011, 2012, 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 ClassLoaderData; class MetaWord; class Mutex; class outputStream; class FreeChunk; template class FreeList; template class BinaryTreeDictionary; class SpaceManager; // 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 VirtualSpaceList; class Metaspace : public CHeapObj { friend class VMStructs; friend class SpaceManager; friend class VM_CollectForMetadataAllocation; friend class MetaspaceGC; friend class MetaspaceAux; public: enum MetadataType {ClassType, NonClassType}; private: void initialize(Mutex* lock, size_t initial_size = 0); static size_t _first_chunk_word_size; SpaceManager* _vsm; SpaceManager* vsm() const { return _vsm; } SpaceManager* _class_vsm; SpaceManager* class_vsm() const { return _class_vsm; } 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 VirtualSpaceList* space_list() { return _space_list; } static VirtualSpaceList* class_space_list() { return _class_space_list; } public: Metaspace(Mutex* lock, size_t initial_size); Metaspace(Mutex* lock); ~Metaspace(); // Initialize globals for Metaspace static void global_initialize(); static void initialize_class_space(ReservedSpace rs); static size_t first_chunk_word_size() { return _first_chunk_word_size; } char* bottom() const; size_t used_words(MetadataType mdtype) const; size_t free_words(MetadataType mdtype) const; size_t capacity_words(MetadataType mdtype) const; size_t waste_words(MetadataType mdtype) const; static MetaWord* allocate(ClassLoaderData* loader_data, size_t size, bool read_only, MetadataType mdtype, TRAPS); void deallocate(MetaWord* ptr, size_t byte_size, bool is_class); MetaWord* expand_and_allocate(size_t size, MetadataType mdtype); static bool is_initialized() { return _class_space_list != NULL; } #ifndef PRODUCT bool contains(const void *ptr) const; bool contains_class(const void *ptr) const; #endif void dump(outputStream* const out) const; void print_on(outputStream* st) const; // Debugging support void verify(); }; class MetaspaceAux : AllStatic { // Statistics for class space and data space in metaspace. static size_t used_in_bytes(Metaspace::MetadataType mdtype); static size_t free_in_bytes(Metaspace::MetadataType mdtype); static size_t capacity_in_bytes(Metaspace::MetadataType mdtype); static size_t reserved_in_bytes(Metaspace::MetadataType mdtype); static size_t free_chunks_total(Metaspace::MetadataType mdtype); static size_t free_chunks_total_in_bytes(Metaspace::MetadataType mdtype); public: // Total of space allocated to metadata in all Metaspaces static size_t used_in_bytes() { return used_in_bytes(Metaspace::ClassType) + used_in_bytes(Metaspace::NonClassType); } // Total of available space in all Metaspaces // Total of capacity allocated to all Metaspaces. This includes // space in Metachunks not yet allocated and in the Metachunk // freelist. static size_t capacity_in_bytes() { return capacity_in_bytes(Metaspace::ClassType) + capacity_in_bytes(Metaspace::NonClassType); } // Total space reserved in all Metaspaces static size_t reserved_in_bytes() { return reserved_in_bytes(Metaspace::ClassType) + reserved_in_bytes(Metaspace::NonClassType); } static size_t min_chunk_size(); // 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_waste(outputStream* out); static void dump(outputStream* out); }; // 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 // the capacity of all space in the virtual lists reaches this value, // a GC is induced and the value is increased. This should be changed // to the space actually used for allocations to avoid affects of // fragmentation losses to partially used chunks. Size is in words. static size_t _capacity_until_GC; // After a GC is done any allocation that fails should try to expand // the capacity of the Metaspaces. This flag is set during attempts // to allocate in the VMGCOperation that does the GC. static bool _expand_after_GC; // For a CMS collection, signal that a concurrent collection should // be started. static bool _should_concurrent_collect; static uint _shrink_factor; static void set_capacity_until_GC(size_t v) { _capacity_until_GC = v; } static size_t shrink_factor() { return _shrink_factor; } void set_shrink_factor(uint v) { _shrink_factor = v; } public: static size_t capacity_until_GC() { return _capacity_until_GC; } static size_t capacity_until_GC_in_bytes() { return _capacity_until_GC * BytesPerWord; } static void inc_capacity_until_GC(size_t v) { _capacity_until_GC += v; } static void dec_capacity_until_GC(size_t v) { _capacity_until_GC = _capacity_until_GC > v ? _capacity_until_GC - v : 0; } static bool expand_after_GC() { return _expand_after_GC; } static void set_expand_after_GC(bool v) { _expand_after_GC = 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 word_size); // It is expected that this will be called when the current capacity // has been used and a GC should be considered. static bool should_expand(VirtualSpaceList* vsl, size_t word_size); // Calculate the new high-water mark at which to induce // a GC. static void compute_new_size(); }; #endif // SHARE_VM_MEMORY_METASPACE_HPP