Mercurial > hg > graal-compiler
view src/share/vm/gc_implementation/g1/sparsePRT.hpp @ 6135:8f37087fc13f
7171890: C1: add Class.isInstance intrinsic
Summary: Class.cast which calls Class.isInstance is heavily used by the new JSR 292 implementation
Reviewed-by: roland
Contributed-by: Krystal Mok <rednaxelafx@gmail.com>
author | roland |
---|---|
date | Tue, 05 Jun 2012 10:15:27 +0200 |
parents | 97ba643ea3ed |
children | d2a62e0f25eb |
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/* * Copyright (c) 2001, 2011, 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_GC_IMPLEMENTATION_G1_SPARSEPRT_HPP #define SHARE_VM_GC_IMPLEMENTATION_G1_SPARSEPRT_HPP #include "gc_implementation/g1/g1CollectedHeap.inline.hpp" #include "gc_implementation/g1/heapRegion.hpp" #include "memory/allocation.hpp" #include "memory/cardTableModRefBS.hpp" #include "runtime/mutex.hpp" #include "utilities/globalDefinitions.hpp" // Sparse remembered set for a heap region (the "owning" region). Maps // indices of other regions to short sequences of cards in the other region // that might contain pointers into the owner region. // These tables only expand while they are accessed in parallel -- // deletions may be done in single-threaded code. This allows us to allow // unsynchronized reads/iterations, as long as expansions caused by // insertions only enqueue old versions for deletions, but do not delete // old versions synchronously. class SparsePRTEntry: public CHeapObj { public: enum SomePublicConstants { NullEntry = -1, UnrollFactor = 4 }; private: RegionIdx_t _region_ind; int _next_index; CardIdx_t _cards[1]; // WARNING: Don't put any data members beyond this line. Card array has, in fact, variable length. // It should always be the last data member. public: // Returns the size of the entry, used for entry allocation. static size_t size() { return sizeof(SparsePRTEntry) + sizeof(CardIdx_t) * (cards_num() - 1); } // Returns the size of the card array. static int cards_num() { // The number of cards should be a multiple of 4, because that's our current // unrolling factor. static const int s = MAX2<int>(G1RSetSparseRegionEntries & ~(UnrollFactor - 1), UnrollFactor); return s; } // Set the region_ind to the given value, and delete all cards. inline void init(RegionIdx_t region_ind); RegionIdx_t r_ind() const { return _region_ind; } bool valid_entry() const { return r_ind() >= 0; } void set_r_ind(RegionIdx_t rind) { _region_ind = rind; } int next_index() const { return _next_index; } int* next_index_addr() { return &_next_index; } void set_next_index(int ni) { _next_index = ni; } // Returns "true" iff the entry contains the given card index. inline bool contains_card(CardIdx_t card_index) const; // Returns the number of non-NULL card entries. inline int num_valid_cards() const; // Requires that the entry not contain the given card index. If there is // space available, add the given card index to the entry and return // "true"; otherwise, return "false" to indicate that the entry is full. enum AddCardResult { overflow, found, added }; inline AddCardResult add_card(CardIdx_t card_index); // Copy the current entry's cards into "cards". inline void copy_cards(CardIdx_t* cards) const; // Copy the current entry's cards into the "_card" array of "e." inline void copy_cards(SparsePRTEntry* e) const; inline CardIdx_t card(int i) const { return _cards[i]; } }; class RSHashTable : public CHeapObj { friend class RSHashTableIter; enum SomePrivateConstants { NullEntry = -1 }; size_t _capacity; size_t _capacity_mask; size_t _occupied_entries; size_t _occupied_cards; SparsePRTEntry* _entries; int* _buckets; int _free_region; int _free_list; // Requires that the caller hold a lock preventing parallel modifying // operations, and that the the table be less than completely full. If // an entry for "region_ind" is already in the table, finds it and // returns its address; otherwise returns "NULL." SparsePRTEntry* entry_for_region_ind(RegionIdx_t region_ind) const; // Requires that the caller hold a lock preventing parallel modifying // operations, and that the the table be less than completely full. If // an entry for "region_ind" is already in the table, finds it and // returns its address; otherwise allocates, initializes, inserts and // returns a new entry for "region_ind". SparsePRTEntry* entry_for_region_ind_create(RegionIdx_t region_ind); // Returns the index of the next free entry in "_entries". int alloc_entry(); // Declares the entry "fi" to be free. (It must have already been // deleted from any bucket lists. void free_entry(int fi); public: RSHashTable(size_t capacity); ~RSHashTable(); // Attempts to ensure that the given card_index in the given region is in // the sparse table. If successful (because the card was already // present, or because it was successfullly added) returns "true". // Otherwise, returns "false" to indicate that the addition would // overflow the entry for the region. The caller must transfer these // entries to a larger-capacity representation. bool add_card(RegionIdx_t region_id, CardIdx_t card_index); bool get_cards(RegionIdx_t region_id, CardIdx_t* cards); bool delete_entry(RegionIdx_t region_id); bool contains_card(RegionIdx_t region_id, CardIdx_t card_index) const; void add_entry(SparsePRTEntry* e); SparsePRTEntry* get_entry(RegionIdx_t region_id); void clear(); size_t capacity() const { return _capacity; } size_t capacity_mask() const { return _capacity_mask; } size_t occupied_entries() const { return _occupied_entries; } size_t occupied_cards() const { return _occupied_cards; } size_t mem_size() const; SparsePRTEntry* entry(int i) const { return (SparsePRTEntry*)((char*)_entries + SparsePRTEntry::size() * i); } void print(); }; // ValueObj because will be embedded in HRRS iterator. class RSHashTableIter VALUE_OBJ_CLASS_SPEC { int _tbl_ind; // [-1, 0.._rsht->_capacity) int _bl_ind; // [-1, 0.._rsht->_capacity) short _card_ind; // [0..SparsePRTEntry::cards_num()) RSHashTable* _rsht; // If the bucket list pointed to by _bl_ind contains a card, sets // _bl_ind to the index of that entry, and returns the card. // Otherwise, returns SparseEntry::NullEntry. CardIdx_t find_first_card_in_list(); // Computes the proper card index for the card whose offset in the // current region (as indicated by _bl_ind) is "ci". // This is subject to errors when there is iteration concurrent with // modification, but these errors should be benign. size_t compute_card_ind(CardIdx_t ci); public: RSHashTableIter() : _tbl_ind(RSHashTable::NullEntry), _bl_ind(RSHashTable::NullEntry), _card_ind((SparsePRTEntry::cards_num() - 1)), _rsht(NULL) {} void init(RSHashTable* rsht) { _rsht = rsht; _tbl_ind = -1; // So that first increment gets to 0. _bl_ind = RSHashTable::NullEntry; _card_ind = (SparsePRTEntry::cards_num() - 1); } bool has_next(size_t& card_index); }; // Concurrent accesss to a SparsePRT must be serialized by some external // mutex. class SparsePRTIter; class SparsePRTCleanupTask; class SparsePRT VALUE_OBJ_CLASS_SPEC { friend class SparsePRTCleanupTask; // Iterations are done on the _cur hash table, since they only need to // see entries visible at the start of a collection pause. // All other operations are done using the _next hash table. RSHashTable* _cur; RSHashTable* _next; HeapRegion* _hr; enum SomeAdditionalPrivateConstants { InitialCapacity = 16 }; void expand(); bool _expanded; bool expanded() { return _expanded; } void set_expanded(bool b) { _expanded = b; } SparsePRT* _next_expanded; SparsePRT* next_expanded() { return _next_expanded; } void set_next_expanded(SparsePRT* nxt) { _next_expanded = nxt; } bool should_be_on_expanded_list(); static SparsePRT* _head_expanded_list; public: SparsePRT(HeapRegion* hr); ~SparsePRT(); size_t occupied() const { return _next->occupied_cards(); } size_t mem_size() const; // Attempts to ensure that the given card_index in the given region is in // the sparse table. If successful (because the card was already // present, or because it was successfullly added) returns "true". // Otherwise, returns "false" to indicate that the addition would // overflow the entry for the region. The caller must transfer these // entries to a larger-capacity representation. bool add_card(RegionIdx_t region_id, CardIdx_t card_index); // If the table hold an entry for "region_ind", Copies its // cards into "cards", which must be an array of length at least // "SparePRTEntry::cards_num()", and returns "true"; otherwise, // returns "false". bool get_cards(RegionIdx_t region_ind, CardIdx_t* cards); // Return the pointer to the entry associated with the given region. SparsePRTEntry* get_entry(RegionIdx_t region_ind); // If there is an entry for "region_ind", removes it and return "true"; // otherwise returns "false." bool delete_entry(RegionIdx_t region_ind); // Clear the table, and reinitialize to initial capacity. void clear(); // Ensure that "_cur" and "_next" point to the same table. void cleanup(); // Clean up all tables on the expanded list. Called single threaded. static void cleanup_all(); RSHashTable* cur() const { return _cur; } void init_iterator(SparsePRTIter* sprt_iter); static void add_to_expanded_list(SparsePRT* sprt); static SparsePRT* get_from_expanded_list(); // The purpose of these three methods is to help the GC workers // during the cleanup pause to recreate the expanded list, purging // any tables from it that belong to regions that are freed during // cleanup (if we don't purge those tables, there is a race that // causes various crashes; see CR 7014261). // // We chose to recreate the expanded list, instead of purging // entries from it by iterating over it, to avoid this serial phase // at the end of the cleanup pause. // // The three methods below work as follows: // * reset_for_cleanup_tasks() : Nulls the expanded list head at the // start of the cleanup pause. // * do_cleanup_work() : Called by the cleanup workers for every // region that is not free / is being freed by the cleanup // pause. It creates a list of expanded tables whose head / tail // are on the thread-local SparsePRTCleanupTask object. // * finish_cleanup_task() : Called by the cleanup workers after // they complete their cleanup task. It adds the local list into // the global expanded list. It assumes that the // ParGCRareEvent_lock is being held to ensure MT-safety. static void reset_for_cleanup_tasks(); void do_cleanup_work(SparsePRTCleanupTask* sprt_cleanup_task); static void finish_cleanup_task(SparsePRTCleanupTask* sprt_cleanup_task); bool contains_card(RegionIdx_t region_id, CardIdx_t card_index) const { return _next->contains_card(region_id, card_index); } }; class SparsePRTIter: public RSHashTableIter { public: void init(const SparsePRT* sprt) { RSHashTableIter::init(sprt->cur()); } bool has_next(size_t& card_index) { return RSHashTableIter::has_next(card_index); } }; // This allows each worker during a cleanup pause to create a // thread-local list of sparse tables that have been expanded and need // to be processed at the beginning of the next GC pause. This lists // are concatenated into the single expanded list at the end of the // cleanup pause. class SparsePRTCleanupTask VALUE_OBJ_CLASS_SPEC { private: SparsePRT* _head; SparsePRT* _tail; public: SparsePRTCleanupTask() : _head(NULL), _tail(NULL) { } void add(SparsePRT* sprt); SparsePRT* head() { return _head; } SparsePRT* tail() { return _tail; } }; #endif // SHARE_VM_GC_IMPLEMENTATION_G1_SPARSEPRT_HPP