/* * Copyright (c) 2011, 2020, 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_MEMORY_METASPACE_HPP #define SHARE_MEMORY_METASPACE_HPP #include "memory/allocation.hpp" #include "memory/memRegion.hpp" #include "memory/metaspaceChunkFreeListSummary.hpp" #include "memory/virtualspace.hpp" #include "memory/metaspace/metaspaceSizesSnapshot.hpp" #include "runtime/globals.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 // // block X ---+ +-------------------+ // | | Virtualspace | // | | | // | | | // | |-------------------| // | || Chunk | // | || | // | ||---------- | // +------>||| block 0 | | // ||---------- | // ||| block 1 | | // ||---------- | // || | // |-------------------| // | | // | | // +-------------------+ // class ClassLoaderData; class MetaspaceTracer; class Mutex; class outputStream; class CollectedHeap; namespace metaspace { class ChunkManager; class ClassLoaderMetaspaceStatistics; class Metablock; class Metachunk; class PrintCLDMetaspaceInfoClosure; class SpaceManager; class VirtualSpaceList; class VirtualSpaceNode; } // 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. // Namespace for important central static functions // (auxiliary stuff goes into MetaspaceUtils) class Metaspace : public AllStatic { friend class MetaspaceShared; public: enum MetadataType { ClassType, NonClassType, MetadataTypeCount }; enum MetaspaceType { ZeroMetaspaceType = 0, StandardMetaspaceType = ZeroMetaspaceType, BootMetaspaceType = StandardMetaspaceType + 1, ClassMirrorHolderMetaspaceType = BootMetaspaceType + 1, ReflectionMetaspaceType = ClassMirrorHolderMetaspaceType + 1, MetaspaceTypeCount }; private: // 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 _compressed_class_space_size; static size_t compressed_class_space_size() { return _compressed_class_space_size; } static void set_compressed_class_space_size(size_t size) { _compressed_class_space_size = 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; DEBUG_ONLY(static bool _frozen;) // Virtual Space lists for both classes and other metadata static metaspace::VirtualSpaceList* _space_list; static metaspace::VirtualSpaceList* _class_space_list; static metaspace::ChunkManager* _chunk_manager_metadata; static metaspace::ChunkManager* _chunk_manager_class; static const MetaspaceTracer* _tracer; static bool _initialized; public: static metaspace::VirtualSpaceList* space_list() { return _space_list; } static metaspace::VirtualSpaceList* class_space_list() { return _class_space_list; } static metaspace::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 metaspace::ChunkManager* chunk_manager_metadata() { return _chunk_manager_metadata; } static metaspace::ChunkManager* chunk_manager_class() { return _chunk_manager_class; } static metaspace::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(); } // convenience function static metaspace::ChunkManager* get_chunk_manager(bool is_class) { return is_class ? chunk_manager_class() : chunk_manager_metadata(); } static const MetaspaceTracer* tracer() { return _tracer; } static void freeze() { assert(DumpSharedSpaces, "sanity"); DEBUG_ONLY(_frozen = true;) } static void assert_not_frozen() { assert(!_frozen, "sanity"); } #ifdef _LP64 static void allocate_metaspace_compressed_klass_ptrs(ReservedSpace metaspace_rs, char* requested_addr, address cds_base); #endif private: #ifdef _LP64 static void set_narrow_klass_base_and_shift(ReservedSpace metaspace_rs, address cds_base); static void initialize_class_space(ReservedSpace rs); #endif static ReservedSpace reserve_space(size_t size, size_t alignment, char* requested_addr, bool use_requested_addr); #ifdef PREFERRED_METASPACE_ALIGNMENT static ReservedSpace reserve_preferred_space(size_t size, size_t alignment, bool large_pages, char *requested_addr, bool use_requested_addr); #endif public: static void ergo_initialize(); static void global_initialize(); static void post_initialize(); static void verify_global_initialization(); 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; } static MetaWord* allocate(ClassLoaderData* loader_data, size_t word_size, MetaspaceObj::Type type, TRAPS); static bool contains(const void* ptr); static bool contains_non_shared(const void* ptr); // Free empty virtualspaces static void purge(MetadataType mdtype); static void purge(); static void report_metadata_oome(ClassLoaderData* loader_data, size_t word_size, MetaspaceObj::Type type, MetadataType mdtype, TRAPS); static const char* metadata_type_name(Metaspace::MetadataType mdtype); static void print_compressed_class_space(outputStream* st, const char* requested_addr = 0) NOT_LP64({}); // Return TRUE only if UseCompressedClassPointers is True. static bool using_class_space() { return NOT_LP64(false) LP64_ONLY(UseCompressedClassPointers); } static bool is_class_space_allocation(MetadataType mdType) { return mdType == ClassType && using_class_space(); } static bool initialized() { return _initialized; } }; // Manages the metaspace portion belonging to a class loader class ClassLoaderMetaspace : public CHeapObj { friend class CollectedHeap; // For expand_and_allocate() friend class ZCollectedHeap; // For expand_and_allocate() friend class ShenandoahHeap; // For expand_and_allocate() friend class Metaspace; friend class MetaspaceUtils; friend class metaspace::PrintCLDMetaspaceInfoClosure; friend class VM_CollectForMetadataAllocation; // For expand_and_allocate() private: void initialize(Mutex* lock, Metaspace::MetaspaceType type); // Initialize the first chunk for a Metaspace. Used for // special cases such as the boot class loader, reflection // class loader and hidden class loader. void initialize_first_chunk(Metaspace::MetaspaceType type, Metaspace::MetadataType mdtype); metaspace::Metachunk* get_initialization_chunk(Metaspace::MetaspaceType type, Metaspace::MetadataType mdtype); const Metaspace::MetaspaceType _space_type; Mutex* const _lock; metaspace::SpaceManager* _vsm; metaspace::SpaceManager* _class_vsm; metaspace::SpaceManager* vsm() const { return _vsm; } metaspace::SpaceManager* class_vsm() const { return _class_vsm; } metaspace::SpaceManager* get_space_manager(Metaspace::MetadataType mdtype) { assert(mdtype != Metaspace::MetadataTypeCount, "MetadaTypeCount can't be used as mdtype"); return mdtype == Metaspace::ClassType ? class_vsm() : vsm(); } Mutex* lock() const { return _lock; } MetaWord* expand_and_allocate(size_t size, Metaspace::MetadataType mdtype); size_t class_chunk_size(size_t word_size); // Adds to the given statistic object. Must be locked with CLD metaspace lock. void add_to_statistics_locked(metaspace::ClassLoaderMetaspaceStatistics* out) const; Metaspace::MetaspaceType space_type() const { return _space_type; } public: ClassLoaderMetaspace(Mutex* lock, Metaspace::MetaspaceType type); ~ClassLoaderMetaspace(); // 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, Metaspace::MetadataType mdtype); size_t allocated_blocks_bytes() const; size_t allocated_chunks_bytes() const; void deallocate(MetaWord* ptr, size_t byte_size, bool is_class); void print_on(outputStream* st) const; // Debugging support void verify(); // Adds to the given statistic object. Will lock with CLD metaspace lock. void add_to_statistics(metaspace::ClassLoaderMetaspaceStatistics* out) const; }; // ClassLoaderMetaspace class MetaspaceUtils : AllStatic { // Spacemanager updates running counters. friend class metaspace::SpaceManager; // Special access for error reporting (checks without locks). friend class oopDesc; friend class Klass; // Running counters for statistics concerning in-use chunks. // Note: capacity = used + free + waste + overhead. Note that we do not // count free and waste. Their sum can be deduces from the three other values. // For more details, one should call print_report() from within a safe point. static size_t _capacity_words [Metaspace:: MetadataTypeCount]; static size_t _overhead_words [Metaspace:: MetadataTypeCount]; static volatile size_t _used_words [Metaspace:: MetadataTypeCount]; // Atomically decrement or increment in-use statistic counters static void dec_capacity(Metaspace::MetadataType mdtype, size_t words); static void inc_capacity(Metaspace::MetadataType mdtype, size_t words); static void dec_used(Metaspace::MetadataType mdtype, size_t words); static void inc_used(Metaspace::MetadataType mdtype, size_t words); static void dec_overhead(Metaspace::MetadataType mdtype, size_t words); static void inc_overhead(Metaspace::MetadataType mdtype, size_t words); // Getters for the in-use counters. static size_t capacity_words(Metaspace::MetadataType mdtype) { return _capacity_words[mdtype]; } static size_t used_words(Metaspace::MetadataType mdtype) { return _used_words[mdtype]; } static size_t overhead_words(Metaspace::MetadataType mdtype) { return _overhead_words[mdtype]; } static size_t free_chunks_total_words(Metaspace::MetadataType mdtype); // Helper for print_xx_report. static void print_vs(outputStream* out, size_t scale); public: // Collect used metaspace statistics. This involves walking the CLDG. The resulting // output will be the accumulated values for all live metaspaces. // Note: method does not do any locking. static void collect_statistics(metaspace::ClassLoaderMetaspaceStatistics* out); // 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 capacity_words() { return capacity_words(Metaspace::NonClassType) + capacity_words(Metaspace::ClassType); } static size_t capacity_bytes(Metaspace::MetadataType mdtype) { return capacity_words(mdtype) * BytesPerWord; } static size_t capacity_bytes() { return capacity_words() * BytesPerWord; } static size_t used_words() { return used_words(Metaspace::NonClassType) + used_words(Metaspace::ClassType); } static size_t used_bytes(Metaspace::MetadataType mdtype) { return used_words(mdtype) * BytesPerWord; } static size_t used_bytes() { return used_words() * BytesPerWord; } // Space committed but yet unclaimed by any class loader. static size_t free_in_vs_bytes(); static size_t free_in_vs_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(); // Flags for print_report(). enum ReportFlag { // Show usage by class loader. rf_show_loaders = (1 << 0), // Breaks report down by chunk type (small, medium, ...). rf_break_down_by_chunktype = (1 << 1), // Breaks report down by space type (hidden, reflection, ...). rf_break_down_by_spacetype = (1 << 2), // Print details about the underlying virtual spaces. rf_show_vslist = (1 << 3), // Print metaspace map. rf_show_vsmap = (1 << 4), // If show_loaders: show loaded classes for each loader. rf_show_classes = (1 << 5) }; // This will print out a basic metaspace usage report but // unlike print_report() is guaranteed not to lock or to walk the CLDG. static void print_basic_report(outputStream* st, size_t scale); // Prints a report about the current metaspace state. // Optional parts can be enabled via flags. // Function will walk the CLDG and will lock the expand lock; if that is not // convenient, use print_basic_report() instead. static void print_report(outputStream* out, size_t scale = 0, int flags = 0); static bool has_chunk_free_list(Metaspace::MetadataType mdtype); static MetaspaceChunkFreeListSummary chunk_free_list_summary(Metaspace::MetadataType mdtype); // Log change in used metadata. static void print_metaspace_change(const metaspace::MetaspaceSizesSnapshot& pre_meta_values); static void print_on(outputStream * out); // Prints an ASCII representation of the given space. static void print_metaspace_map(outputStream* out, Metaspace::MetadataType mdtype); static void dump(outputStream* out); static void verify_free_chunks(); // Check internal counters (capacity, 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 size_t _capacity_until_GC; 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(); static void post_initialize(); static size_t capacity_until_GC(); static bool inc_capacity_until_GC(size_t v, size_t* new_cap_until_GC = NULL, size_t* old_cap_until_GC = NULL, bool* can_retry = NULL); static size_t dec_capacity_until_GC(size_t 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_MEMORY_METASPACE_HPP