--- old/src/hotspot/share/memory/metaspace/rootChunkArea.hpp 2020-09-04 13:58:37.277674783 +0200 +++ /dev/null 2020-09-04 12:37:41.765504620 +0200 @@ -1,211 +0,0 @@ -/* - * Copyright (c) 2020, Oracle and/or its affiliates. All rights reserved. - * Copyright (c) 2020 SAP SE. 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_ROOTCHUNKAREA_HPP -#define SHARE_MEMORY_METASPACE_ROOTCHUNKAREA_HPP - -#include "memory/allocation.hpp" -#include "memory/metaspace/chunkLevel.hpp" -#include "utilities/debug.hpp" -#include "utilities/globalDefinitions.hpp" - -class outputStream; - -namespace metaspace { - -class Metachunk; -class MetachunkClosure; -class FreeChunkListVector; -class VirtualSpaceNode; - - -// RootChunkArea manages a memory area covering a single root chunk. -// -// Such an area may contain a single root chunk, or a number of chunks the -// root chunk was split into. -// -// RootChunkArea contains the functionality to merge and split chunks in -// buddy allocator fashion. -// - -class RootChunkArea { - - // The base address of this area. - // Todo: this may be somewhat superfluous since RootChunkArea only exist in the - // context of a series of chunks, so the address is somewhat implicit. Remove? - const MetaWord* const _base; - - // The first chunk in this area; if this area is maximally - // folded, this is the root chunk covering the whole area size. - Metachunk* _first_chunk; - -public: - - RootChunkArea(const MetaWord* base); - ~RootChunkArea(); - - // Initialize: allocate a root node and a root chunk header; return the - // root chunk header. It will be partly initialized. - // Note: this just allocates a memory-less header; memory itself is allocated inside VirtualSpaceNode. - Metachunk* alloc_root_chunk_header(VirtualSpaceNode* node); - - - // Given a chunk c, split it recursively until you get a chunk of the given target_level. - // - // The resulting target chunk resides at the same address as the original chunk. - // The resulting splinters are added to freelists. - // - // Returns pointer to the result chunk; the splitted-off chunks are added as - // free chunks to the freelists. - void split(chunklevel_t target_level, Metachunk* c, FreeChunkListVector* freelists); - - // Given a chunk, attempt to merge it recursively with its neighboring chunks. - // - // If successful (merged at least once), returns address of - // the merged chunk; NULL otherwise. - // - // The merged chunks are removed from the freelists. - // - // !!! Please note that if this method returns a non-NULL value, the - // original chunk will be invalid and should not be accessed anymore! !!! - Metachunk* merge(Metachunk* c, FreeChunkListVector* freelists); - - // Given a chunk c, which must be "in use" and must not be a root chunk, attempt to - // enlarge it in place by claiming its trailing buddy. - // - // This will only work if c is the leader of the buddy pair and the trailing buddy is free. - // - // If successful, the follower chunk will be removed from the freelists, the leader chunk c will - // double in size (level decreased by one). - // - // On success, true is returned, false otherwise. - bool attempt_enlarge_chunk(Metachunk* c, FreeChunkListVector* freelists); - - /// range /// - - const MetaWord* base() const { return _base; } - size_t word_size() const { return chunklevel::MAX_CHUNK_WORD_SIZE; } - const MetaWord* end() const { return _base + word_size(); } - - // Direct access to the first chunk (use with care) - Metachunk* first_chunk() { return _first_chunk; } - const Metachunk* first_chunk() const { return _first_chunk; } - - // Returns true if this root chunk area is completely free: - // In that case, it should only contain one chunk (maximally merged, so a root chunk) - // and it should be free. - bool is_free() const; - - //// Debug stuff //// - -#ifdef ASSERT - void check_pointer(const MetaWord* p) const { - assert(p >= _base && p < _base + word_size(), - "pointer " PTR_FORMAT " oob for this root area [" PTR_FORMAT ".." PTR_FORMAT ")", - p2i(p), p2i(_base), p2i(_base + word_size())); - } - void verify(bool slow) const; - - // This is a separate operation from verify(). We should be able to call verify() - // from almost anywhere, regardless of state, but verify_area_is_ideally_merged() - // can only be called outside split and merge ops. - void verify_area_is_ideally_merged() const; -#endif // ASSERT - - void print_on(outputStream* st) const; - -}; - - -// RootChunkAreaLUT (lookup table) manages a series of contiguous root chunk areas -// in memory (in the context of a VirtualSpaceNode). It allows finding the containing -// root chunk for any given memory address. It allows for easy iteration over all -// root chunks. -// Beyond that it is unexciting. -class RootChunkAreaLUT { - - // Base address of the whole area. - const MetaWord* const _base; - - // Number of root chunk areas. - const int _num; - - // Array of RootChunkArea objects. - RootChunkArea* _arr; - -#ifdef ASSERT - void check_pointer(const MetaWord* p) const { - assert(p >= base() && p < base() + word_size(), "Invalid pointer"); - } -#endif - - // Given an address into this range, return the index into the area array for the - // area this address falls into. - int index_by_address(const MetaWord* p) const { - DEBUG_ONLY(check_pointer(p);) - int idx = (int)((p - base()) / chunklevel::MAX_CHUNK_WORD_SIZE); - assert(idx >= 0 && idx < _num, "Sanity"); - return idx; - } - -public: - - RootChunkAreaLUT(const MetaWord* base, size_t word_size); - ~RootChunkAreaLUT(); - - // Given a memory address into the range this array covers, return the - // corresponding area object. If none existed at this position, create it - // on demand. - RootChunkArea* get_area_by_address(const MetaWord* p) const { - const int idx = index_by_address(p); - RootChunkArea* ra = _arr + idx; - DEBUG_ONLY(ra->check_pointer(p);) - return _arr + idx; - } - - // Access area by its index - int number_of_areas() const { return _num; } - RootChunkArea* get_area_by_index(int index) { assert(index >= 0 && index < _num, "oob"); return _arr + index; } - const RootChunkArea* get_area_by_index(int index) const { assert(index >= 0 && index < _num, "oob"); return _arr + index; } - - /// range /// - - const MetaWord* base() const { return _base; } - size_t word_size() const { return _num * chunklevel::MAX_CHUNK_WORD_SIZE; } - const MetaWord* end() const { return _base + word_size(); } - - // Returns true if all areas in this area table are free (only contain free chunks). - bool is_free() const; - - DEBUG_ONLY(void verify(bool slow) const;) - - void print_on(outputStream* st) const; - -}; - - -} // namespace metaspace - -#endif // SHARE_MEMORY_METASPACE_ROOTCHUNKAREA_HPP