--- /dev/null 2018-05-09 06:13:36.966491568 +0200 +++ new/src/hotspot/share/memory/metaspace/virtualSpaceNode.hpp 2018-05-09 12:24:51.295728499 +0200 @@ -0,0 +1,171 @@ +/* + * Copyright (c) 2018, 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_VIRTUALSPACENODE_HPP_ +#define SHARE_MEMORY_METASPACE_VIRTUALSPACENODE_HPP_ + +#include "memory/virtualspace.hpp" +#include "memory/memRegion.hpp" +#include "utilities/debug.hpp" +#include "utilities/globalDefinitions.hpp" + +class outputStream; + +namespace metaspace { +namespace internals { + +class Metachunk; +class ChunkManager; +class OccupancyMap; + +// A VirtualSpaceList node. +class VirtualSpaceNode : public CHeapObj { + friend class VirtualSpaceList; + + // Link to next VirtualSpaceNode + VirtualSpaceNode* _next; + + // Whether this node is contained in class or metaspace. + const bool _is_class; + + // total in the VirtualSpace + MemRegion _reserved; + ReservedSpace _rs; + VirtualSpace _virtual_space; + MetaWord* _top; + // count of chunks contained in this VirtualSpace + uintx _container_count; + + OccupancyMap* _occupancy_map; + + // Convenience functions to access the _virtual_space + char* low() const { return virtual_space()->low(); } + char* high() const { return virtual_space()->high(); } + + // The first Metachunk will be allocated at the bottom of the + // VirtualSpace + Metachunk* first_chunk() { return (Metachunk*) bottom(); } + + // Committed but unused space in the virtual space + size_t free_words_in_vs() const; + + // True if this node belongs to class metaspace. + bool is_class() const { return _is_class; } + + // Helper function for take_from_committed: allocate padding chunks + // until top is at the given address. + void allocate_padding_chunks_until_top_is_at(MetaWord* target_top); + + public: + + VirtualSpaceNode(bool is_class, size_t byte_size); + VirtualSpaceNode(bool is_class, ReservedSpace rs) : + _is_class(is_class), _top(NULL), _next(NULL), _rs(rs), _container_count(0), _occupancy_map(NULL) {} + ~VirtualSpaceNode(); + + // Convenience functions for logical bottom and end + MetaWord* bottom() const { return (MetaWord*) _virtual_space.low(); } + MetaWord* end() const { return (MetaWord*) _virtual_space.high(); } + + const OccupancyMap* occupancy_map() const { return _occupancy_map; } + OccupancyMap* occupancy_map() { return _occupancy_map; } + + bool contains(const void* ptr) { return ptr >= low() && ptr < high(); } + + size_t reserved_words() const { return _virtual_space.reserved_size() / BytesPerWord; } + size_t committed_words() const { return _virtual_space.actual_committed_size() / BytesPerWord; } + + bool is_pre_committed() const { return _virtual_space.special(); } + + // address of next available space in _virtual_space; + // Accessors + VirtualSpaceNode* next() { return _next; } + void set_next(VirtualSpaceNode* v) { _next = v; } + + void set_reserved(MemRegion const v) { _reserved = v; } + void set_top(MetaWord* v) { _top = v; } + + // Accessors + MemRegion* reserved() { return &_reserved; } + VirtualSpace* virtual_space() const { return (VirtualSpace*) &_virtual_space; } + + // Returns true if "word_size" is available in the VirtualSpace + bool is_available(size_t word_size) { return word_size <= pointer_delta(end(), _top, sizeof(MetaWord)); } + + MetaWord* top() const { return _top; } + void inc_top(size_t word_size) { _top += word_size; } + + uintx container_count() { return _container_count; } + void inc_container_count(); + void dec_container_count(); +#ifdef ASSERT + uintx container_count_slow(); + void verify_container_count(); +#endif + + // used and capacity in this single entry in the list + size_t used_words_in_vs() const; + size_t capacity_words_in_vs() const; + + bool initialize(); + + // get space from the virtual space + Metachunk* take_from_committed(size_t chunk_word_size); + + // Allocate a chunk from the virtual space and return it. + Metachunk* get_chunk_vs(size_t chunk_word_size); + + // Expands/shrinks the committed space in a virtual space. Delegates + // to Virtualspace + bool expand_by(size_t min_words, size_t preferred_words); + + // In preparation for deleting this node, remove all the chunks + // in the node from any freelist. + void purge(ChunkManager* chunk_manager); + + // If an allocation doesn't fit in the current node a new node is created. + // Allocate chunks out of the remaining committed space in this node + // to avoid wasting that memory. + // This always adds up because all the chunk sizes are multiples of + // the smallest chunk size. + void retire(ChunkManager* chunk_manager); + + void print_on(outputStream* st) const { print_on(st, K); } + void print_on(outputStream* st, size_t scale) const; + void print_map(outputStream* st, bool is_class) const; + + // Debug support + DEBUG_ONLY(void mangle();) + // Verify counters, all chunks in this list node and the occupancy map. + DEBUG_ONLY(void verify();) + // Verify that all free chunks in this node are ideally merged + // (there not should be multiple small chunks where a large chunk could exist.) + DEBUG_ONLY(void verify_free_chunks_are_ideally_merged();) + +}; + +} // namespace metaspace +} // namespace internals + +#endif /* SHARE_MEMORY_METASPACE_VIRTUALSPACENODE_HPP_ */