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src/hotspot/share/memory/metaspace/virtualSpaceNode.hpp
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rev 60538 : imported patch jep387-all.patch
*** 1,7 ****
/*
! * Copyright (c) 2018, 2019, 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.
--- 1,8 ----
/*
! * Copyright (c) 2018, 2020, Oracle and/or its affiliates. All rights reserved.
! * Copyright (c) 2018, 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.
*** 23,163 ****
*/
#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 {
! class Metachunk;
! class ChunkManager;
! class OccupancyMap;
- // A VirtualSpaceList node.
class VirtualSpaceNode : public CHeapObj<mtClass> {
- 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
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(); }
- char* low_boundary() const { return virtual_space()->low_boundary(); }
- char* high_boundary() const { return virtual_space()->high_boundary(); }
-
- // 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) :
- _next(NULL), _is_class(is_class), _rs(rs), _top(NULL), _container_count(0), _occupancy_map(NULL) {}
- ~VirtualSpaceNode();
-
- // Convenience functions for logical bottom and (committed) 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_top(MetaWord* v) { _top = v; }
! // Accessors
! 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();
!
! // 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 the committed space by at least min_words words.
! 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 and basic structure. Slow mode: verify all chunks in depth and occupancy map.
! DEBUG_ONLY(void verify(bool slow);)
! // Verify that all free chunks in this node are ideally merged
! // (there should not be multiple small chunks where a large chunk could exist.)
! DEBUG_ONLY(void verify_free_chunks_are_ideally_merged();)
};
} // namespace metaspace
#endif // SHARE_MEMORY_METASPACE_VIRTUALSPACENODE_HPP
--- 24,293 ----
*/
#ifndef SHARE_MEMORY_METASPACE_VIRTUALSPACENODE_HPP
#define SHARE_MEMORY_METASPACE_VIRTUALSPACENODE_HPP
!
! #include "memory/allocation.hpp"
! #include "memory/metaspace/counter.hpp"
! #include "memory/metaspace/commitMask.hpp"
! #include "memory/metaspace/rootChunkArea.hpp"
! #include "memory/metaspace/settings.hpp"
#include "memory/memRegion.hpp"
+ #include "memory/virtualspace.hpp"
#include "utilities/debug.hpp"
+ #include "utilities/bitMap.hpp"
#include "utilities/globalDefinitions.hpp"
+
class outputStream;
namespace metaspace {
! class CommitLimiter;
! class FreeChunkListVector;
!
! // VirtualSpaceNode manages a single contiguous address range of metaspace. Logically that memory
! // region is split up into a sequence of "root chunk areas", each one containing one root chunk
! // or splinters of a root chunk.
! //
! // The underlying memory is also logically divided into a number of "commit granules", units of memory
! // which may be committed or uncommitted independently from each other.
! //
! // (Both root chunk areas and commit granules have not much to do with each other - one is a way to
! // reserve memory for the upper regions, see ChunkManager. One is a way to manage commited memory.)
! //
! // VirtualSpaceNode:
! // - exposes a function to allocate a new root chunk (see VirtualSpaceNode::allocate_root_chunk()).
! //
! // - knows about the commit state of the memory region - which commit granule are committed, which
! // are not. It exposes functions to commit and uncommit regions (without actively committing
! // itself)
! //
! // - It has a reference to a "CommitLimiter", an interface to query whether committing is
! // possible. That interface hides the various ways committing may be limited (GC threshold,
! // MaxMetaspaceSize, ...)
! //
! // - It uses ReservedSpace to reserve its memory. It either owns the ReservedSpace or that
! // space got handed in from outside (ccs).
! //
! //
! //
! //
! // | root chunk area | root chunk area | root chunk area | <-- root chunk areas
! //
! // +-----------------------------------------------------------------------------------------------+
! // | |
! // | `VirtualSpaceNode` memory |
! // | |
! // +-----------------------------------------------------------------------------------------------+
! //
! // |x| |x|x|x| | | | |x|x|x| | | |x|x| | | |x|x|x|x| | | | | | | | |x| | | |x|x|x|x| | | |x| | | |x| <-- commit granules
! //
! // (x = committed)
! //
class VirtualSpaceNode : public CHeapObj<mtClass> {
// Link to next VirtualSpaceNode
VirtualSpaceNode* _next;
! // The underlying space. This has been either created by this node
! // and is owned by it, or has been handed in from outside (e.g. in
! // case of CompressedClassSpace).
ReservedSpace _rs;
! // True if the node owns the reserved space, false if not.
! const bool _owns_rs;
! // Start pointer of the area.
! MetaWord* const _base;
! // Size, in words, of the whole node
! const size_t _word_size;
! // Size, in words, of the range of this node which has been handed out in
! // the form of root chunks.
! size_t _used_words;
!
! // The bitmap describing the commit state of the region:
! // Each bit covers a region of 64K (see constants::commit_granule_size).
! CommitMask _commit_mask;
!
! // An array/lookup table of RootChunkArea objects. Each one describes a root chunk area.
! RootChunkAreaLUT _root_chunk_area_lut;
!
! // Limiter object to ask before expanding the committed size of this node.
! CommitLimiter* const _commit_limiter;
!
! // Points to outside size counters which we are to increase/decrease when we commit/uncommit
! // space from this node.
! SizeCounter* const _total_reserved_words_counter;
! SizeCounter* const _total_committed_words_counter;
!
! /// committing, uncommitting ///
!
! // Given a pointer into this node, calculate the start of the commit granule
! // the pointer points into.
! MetaWord* calc_start_of_granule(MetaWord* p) const {
! DEBUG_ONLY(check_pointer(p));
! return align_down(p, Settings::commit_granule_bytes());
! }
!
! // Given an address range, ensure it is committed.
! //
! // The range has to be aligned to granule size.
! //
! // Function will:
! // - check how many granules in that region are uncommitted; If all are committed, it
! // returns true immediately.
! // - check if committing those uncommitted granules would bring us over the commit limit
! // (GC threshold, MaxMetaspaceSize). If true, it returns false.
! // - commit the memory.
! // - mark the range as committed in the commit mask
! //
! // Returns true if success, false if it did hit a commit limit.
! bool commit_range(MetaWord* p, size_t word_size);
!
! //// creation ////
!
! // Create a new empty node spanning the given given reserved space.
! VirtualSpaceNode(ReservedSpace rs, bool owns_rs, CommitLimiter* limiter,
! SizeCounter* reserve_counter, SizeCounter* commit_counter);
!
! public:
!
! // Create a node of a given size (it will create its own space).
! static VirtualSpaceNode* create_node(size_t word_size, CommitLimiter* limiter, SizeCounter* reserve_words_counter,
! SizeCounter* commit_words_counter);
!
! // Create a node over an existing space
! static VirtualSpaceNode* create_node(ReservedSpace rs, CommitLimiter* limiter, SizeCounter* reserve_words_counter,
! SizeCounter* commit_words_counter);
! ~VirtualSpaceNode();
! // Note: public for gtests only, could be private.
! MetaWord* base() const { return _base; }
! // Reserved size of the whole node.
! size_t word_size() const { return _word_size; }
! //// Chunk allocation, splitting, merging /////
! // Allocate a root chunk from this node. Will fail and return NULL if the node is full
! // - if we used up the whole address space of this node's memory region.
! // (in case this node backs compressed class space, this is how we hit
! // CompressedClassSpaceSize).
! // Note that this just returns reserved memory; caller must take care of committing this
! // chunk before using it.
! Metachunk* allocate_root_chunk();
!
! // 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.
! 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);
!
! // Attempts to purge the node:
! //
! // If all chunks living in this node are free, they will all be removed from
! // the freelist they currently reside in. Then, the node will be deleted.
! //
! // Returns true if the node has been deleted, false if not.
! // !! If this returns true, do not access the node from this point on. !!
! bool attempt_purge(FreeChunkListVector* freelists);
!
! // Attempts to uncommit free areas according to the rules set in settings.
! // Returns number of words uncommitted.
! size_t uncommit_free_areas();
!
! /// misc /////
!
! // Returns size, in words, of the used space in this node alone.
! // (Notes:
! // - This is the space handed out to the ChunkManager, so it is "used" from the viewpoint of this node,
! // but not necessarily used for Metadata.
! // - This may or may not be committed memory.
! size_t used_words() const { return _used_words; }
!
! // Returns size, in words, of how much space is left in this node alone.
! size_t free_words() const { return _word_size - _used_words; }
!
! // Returns size, in words, of committed space in this node alone.
! // Note: iterates over commit mask and hence may be a tad expensive on large nodes.
! size_t committed_words() const;
!
! //// Committing/uncommitting memory /////
!
! // Given an address range, ensure it is committed.
! //
! // The range does not have to be aligned to granule size. However, the function will always commit
! // whole granules.
! //
! // Function will:
! // - check how many granules in that region are uncommitted; If all are committed, it
! // returns true immediately.
! // - check if committing those uncommitted granules would bring us over the commit limit
! // (GC threshold, MaxMetaspaceSize). If true, it returns false.
! // - commit the memory.
! // - mark the range as committed in the commit mask
! //
! // Returns true if success, false if it did hit a commit limit.
! bool ensure_range_is_committed(MetaWord* p, size_t word_size);
!
! // Given an address range (which has to be aligned to commit granule size):
! // - uncommit it
! // - mark it as uncommitted in the commit mask
! void uncommit_range(MetaWord* p, size_t word_size);
!
! //// List stuff ////
! VirtualSpaceNode* next() const { return _next; }
! void set_next(VirtualSpaceNode* vsn) { _next = vsn; }
!
!
! /// Debug stuff ////
!
! // Print a description about this node.
! void print_on(outputStream* st) const;
!
! // Verify counters and basic structure. Slow mode: verify all chunks in depth
! bool contains(const MetaWord* p) const {
! return p >= _base && p < _base + _used_words;
! }
!
! #ifdef ASSERT
! void check_pointer(const MetaWord* p) const {
! assert(contains(p), "invalid pointer");
! }
! void verify(bool slow) const;
! void verify_locked(bool slow) const;
! #endif
};
+
} // namespace metaspace
#endif // SHARE_MEMORY_METASPACE_VIRTUALSPACENODE_HPP
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