diff -r caf5eb7dd4a7 -r 882756847a04 hotspot/src/share/vm/memory/metaspace.hpp --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/hotspot/src/share/vm/memory/metaspace.hpp Sat Sep 01 13:25:18 2012 -0400 @@ -0,0 +1,249 @@ +/* + * 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); + +#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