| /* |
| * Copyright (c) 1997, 2016, 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_UTILITIES_BITMAP_HPP |
| #define SHARE_VM_UTILITIES_BITMAP_HPP |
| |
| #include "memory/allocation.hpp" |
| |
| // Forward decl; |
| class BitMapClosure; |
| |
| // Operations for bitmaps represented as arrays of unsigned integers. |
| // Bit offsets are numbered from 0 to size-1. |
| |
| class BitMap VALUE_OBJ_CLASS_SPEC { |
| friend class BitMap2D; |
| |
| public: |
| typedef size_t idx_t; // Type used for bit and word indices. |
| typedef uintptr_t bm_word_t; // Element type of array that represents |
| // the bitmap. |
| |
| // Hints for range sizes. |
| typedef enum { |
| unknown_range, small_range, large_range |
| } RangeSizeHint; |
| |
| private: |
| bm_word_t* _map; // First word in bitmap |
| idx_t _size; // Size of bitmap (in bits) |
| |
| // Puts the given value at the given offset, using resize() to size |
| // the bitmap appropriately if needed using factor-of-two expansion. |
| void at_put_grow(idx_t index, bool value); |
| |
| protected: |
| // Return the position of bit within the word that contains it (e.g., if |
| // bitmap words are 32 bits, return a number 0 <= n <= 31). |
| static idx_t bit_in_word(idx_t bit) { return bit & (BitsPerWord - 1); } |
| |
| // Return a mask that will select the specified bit, when applied to the word |
| // containing the bit. |
| static bm_word_t bit_mask(idx_t bit) { return (bm_word_t)1 << bit_in_word(bit); } |
| |
| // Return the index of the word containing the specified bit. |
| static idx_t word_index(idx_t bit) { return bit >> LogBitsPerWord; } |
| |
| // Return the bit number of the first bit in the specified word. |
| static idx_t bit_index(idx_t word) { return word << LogBitsPerWord; } |
| |
| // Return the array of bitmap words, or a specific word from it. |
| bm_word_t* map() const { return _map; } |
| bm_word_t map(idx_t word) const { return _map[word]; } |
| |
| // Return a pointer to the word containing the specified bit. |
| bm_word_t* word_addr(idx_t bit) const { return map() + word_index(bit); } |
| |
| // Set a word to a specified value or to all ones; clear a word. |
| void set_word (idx_t word, bm_word_t val) { _map[word] = val; } |
| void set_word (idx_t word) { set_word(word, ~(bm_word_t)0); } |
| void clear_word(idx_t word) { _map[word] = 0; } |
| |
| // Utilities for ranges of bits. Ranges are half-open [beg, end). |
| |
| // Ranges within a single word. |
| bm_word_t inverted_bit_mask_for_range(idx_t beg, idx_t end) const; |
| void set_range_within_word (idx_t beg, idx_t end); |
| void clear_range_within_word (idx_t beg, idx_t end); |
| void par_put_range_within_word (idx_t beg, idx_t end, bool value); |
| |
| // Ranges spanning entire words. |
| void set_range_of_words (idx_t beg, idx_t end); |
| void clear_range_of_words (idx_t beg, idx_t end); |
| void set_large_range_of_words (idx_t beg, idx_t end); |
| void clear_large_range_of_words (idx_t beg, idx_t end); |
| |
| // The index of the first full word in a range. |
| idx_t word_index_round_up(idx_t bit) const; |
| |
| // Verification. |
| void verify_index(idx_t index) const NOT_DEBUG_RETURN; |
| void verify_range(idx_t beg_index, idx_t end_index) const NOT_DEBUG_RETURN; |
| |
| // Statistics. |
| static idx_t* _pop_count_table; |
| static void init_pop_count_table(); |
| static idx_t num_set_bits(bm_word_t w); |
| static idx_t num_set_bits_from_table(unsigned char c); |
| |
| public: |
| |
| // Constructs a bitmap with no map, and size 0. |
| BitMap() : _map(NULL), _size(0) {} |
| |
| // Constructs a bitmap with the given map and size. |
| BitMap(bm_word_t* map, idx_t size_in_bits) :_map(map), _size(size_in_bits) {} |
| |
| // Constructs an empty bitmap of the given size (that is, this clears the |
| // new bitmap). Allocates the map array in resource area if |
| // "in_resource_area" is true, else in the C heap. |
| BitMap(idx_t size_in_bits, bool in_resource_area = true); |
| |
| // Set the map and size. |
| void set_map(bm_word_t* map) { _map = map; } |
| void set_size(idx_t size_in_bits) { _size = size_in_bits; } |
| |
| // Allocates necessary data structure, either in the resource area |
| // or in the C heap, as indicated by "in_resource_area." |
| // Preserves state currently in bit map by copying data. |
| // Zeros any newly-addressable bits. |
| // If "in_resource_area" is false, frees the current map. |
| // (Note that this assumes that all calls to "resize" on the same BitMap |
| // use the same value for "in_resource_area".) |
| void resize(idx_t size_in_bits, bool in_resource_area = true); |
| |
| // Pretouch the entire range of memory this BitMap covers. |
| void pretouch(); |
| |
| // Accessing |
| idx_t size() const { return _size; } |
| idx_t size_in_bytes() const { return size_in_words() * BytesPerWord; } |
| idx_t size_in_words() const { |
| return calc_size_in_words(size()); |
| } |
| |
| static idx_t calc_size_in_words(size_t size_in_bits) { |
| return word_index(size_in_bits + BitsPerWord - 1); |
| } |
| |
| bool at(idx_t index) const { |
| verify_index(index); |
| return (*word_addr(index) & bit_mask(index)) != 0; |
| } |
| |
| // Align bit index up or down to the next bitmap word boundary, or check |
| // alignment. |
| static idx_t word_align_up(idx_t bit) { |
| return align_size_up(bit, BitsPerWord); |
| } |
| static idx_t word_align_down(idx_t bit) { |
| return align_size_down(bit, BitsPerWord); |
| } |
| static bool is_word_aligned(idx_t bit) { |
| return word_align_up(bit) == bit; |
| } |
| |
| // Set or clear the specified bit. |
| inline void set_bit(idx_t bit); |
| inline void clear_bit(idx_t bit); |
| |
| // Atomically set or clear the specified bit. |
| inline bool par_set_bit(idx_t bit); |
| inline bool par_clear_bit(idx_t bit); |
| |
| // Put the given value at the given offset. The parallel version |
| // will CAS the value into the bitmap and is quite a bit slower. |
| // The parallel version also returns a value indicating if the |
| // calling thread was the one that changed the value of the bit. |
| void at_put(idx_t index, bool value); |
| bool par_at_put(idx_t index, bool value); |
| |
| // Update a range of bits. Ranges are half-open [beg, end). |
| void set_range (idx_t beg, idx_t end); |
| void clear_range (idx_t beg, idx_t end); |
| void set_large_range (idx_t beg, idx_t end); |
| void clear_large_range (idx_t beg, idx_t end); |
| void at_put_range(idx_t beg, idx_t end, bool value); |
| void par_at_put_range(idx_t beg, idx_t end, bool value); |
| void at_put_large_range(idx_t beg, idx_t end, bool value); |
| void par_at_put_large_range(idx_t beg, idx_t end, bool value); |
| |
| // Update a range of bits, using a hint about the size. Currently only |
| // inlines the predominant case of a 1-bit range. Works best when hint is a |
| // compile-time constant. |
| void set_range(idx_t beg, idx_t end, RangeSizeHint hint); |
| void clear_range(idx_t beg, idx_t end, RangeSizeHint hint); |
| void par_set_range(idx_t beg, idx_t end, RangeSizeHint hint); |
| void par_clear_range (idx_t beg, idx_t end, RangeSizeHint hint); |
| |
| // Clearing |
| void clear_large(); |
| inline void clear(); |
| |
| // Iteration support. Returns "true" if the iteration completed, false |
| // if the iteration terminated early (because the closure "blk" returned |
| // false). |
| bool iterate(BitMapClosure* blk, idx_t leftIndex, idx_t rightIndex); |
| bool iterate(BitMapClosure* blk) { |
| // call the version that takes an interval |
| return iterate(blk, 0, size()); |
| } |
| |
| // Looking for 1's and 0's at indices equal to or greater than "l_index", |
| // stopping if none has been found before "r_index", and returning |
| // "r_index" (which must be at most "size") in that case. |
| idx_t get_next_one_offset_inline (idx_t l_index, idx_t r_index) const; |
| idx_t get_next_zero_offset_inline(idx_t l_index, idx_t r_index) const; |
| |
| // Like "get_next_one_offset_inline", except requires that "r_index" is |
| // aligned to bitsizeof(bm_word_t). |
| idx_t get_next_one_offset_inline_aligned_right(idx_t l_index, |
| idx_t r_index) const; |
| |
| // Non-inline versionsof the above. |
| idx_t get_next_one_offset (idx_t l_index, idx_t r_index) const; |
| idx_t get_next_zero_offset(idx_t l_index, idx_t r_index) const; |
| |
| idx_t get_next_one_offset(idx_t offset) const { |
| return get_next_one_offset(offset, size()); |
| } |
| idx_t get_next_zero_offset(idx_t offset) const { |
| return get_next_zero_offset(offset, size()); |
| } |
| |
| // Returns the number of bits set in the bitmap. |
| idx_t count_one_bits() const; |
| |
| // Set operations. |
| void set_union(BitMap bits); |
| void set_difference(BitMap bits); |
| void set_intersection(BitMap bits); |
| // Returns true iff "this" is a superset of "bits". |
| bool contains(const BitMap bits) const; |
| // Returns true iff "this and "bits" have a non-empty intersection. |
| bool intersects(const BitMap bits) const; |
| |
| // Returns result of whether this map changed |
| // during the operation |
| bool set_union_with_result(BitMap bits); |
| bool set_difference_with_result(BitMap bits); |
| bool set_intersection_with_result(BitMap bits); |
| |
| // Requires the submap of "bits" starting at offset to be at least as |
| // large as "this". Modifies "this" to be the intersection of its |
| // current contents and the submap of "bits" starting at "offset" of the |
| // same length as "this." |
| // (For expedience, currently requires the offset to be aligned to the |
| // bitsize of a uintptr_t. This should go away in the future though it |
| // will probably remain a good case to optimize.) |
| void set_intersection_at_offset(BitMap bits, idx_t offset); |
| |
| void set_from(BitMap bits); |
| |
| bool is_same(BitMap bits); |
| |
| // Test if all bits are set or cleared |
| bool is_full() const; |
| bool is_empty() const; |
| |
| void print_on_error(outputStream* st, const char* prefix) const; |
| |
| #ifndef PRODUCT |
| public: |
| // Printing |
| void print_on(outputStream* st) const; |
| #endif |
| }; |
| |
| // Convenience class wrapping BitMap which provides multiple bits per slot. |
| class BitMap2D VALUE_OBJ_CLASS_SPEC { |
| public: |
| typedef BitMap::idx_t idx_t; // Type used for bit and word indices. |
| typedef BitMap::bm_word_t bm_word_t; // Element type of array that |
| // represents the bitmap. |
| private: |
| BitMap _map; |
| idx_t _bits_per_slot; |
| |
| idx_t bit_index(idx_t slot_index, idx_t bit_within_slot_index) const { |
| return slot_index * _bits_per_slot + bit_within_slot_index; |
| } |
| |
| void verify_bit_within_slot_index(idx_t index) const { |
| assert(index < _bits_per_slot, "bit_within_slot index out of bounds"); |
| } |
| |
| public: |
| // Construction. bits_per_slot must be greater than 0. |
| BitMap2D(bm_word_t* map, idx_t size_in_slots, idx_t bits_per_slot); |
| |
| // Allocates necessary data structure in resource area. bits_per_slot must be greater than 0. |
| BitMap2D(idx_t size_in_slots, idx_t bits_per_slot); |
| |
| idx_t size_in_bits() { |
| return _map.size(); |
| } |
| |
| // Returns number of full slots that have been allocated |
| idx_t size_in_slots() { |
| // Round down |
| return _map.size() / _bits_per_slot; |
| } |
| |
| bool is_valid_index(idx_t slot_index, idx_t bit_within_slot_index); |
| bool at(idx_t slot_index, idx_t bit_within_slot_index) const; |
| void set_bit(idx_t slot_index, idx_t bit_within_slot_index); |
| void clear_bit(idx_t slot_index, idx_t bit_within_slot_index); |
| void at_put(idx_t slot_index, idx_t bit_within_slot_index, bool value); |
| void at_put_grow(idx_t slot_index, idx_t bit_within_slot_index, bool value); |
| void clear(); |
| }; |
| |
| // Closure for iterating over BitMaps |
| |
| class BitMapClosure VALUE_OBJ_CLASS_SPEC { |
| public: |
| // Callback when bit in map is set. Should normally return "true"; |
| // return of false indicates that the bitmap iteration should terminate. |
| virtual bool do_bit(BitMap::idx_t offset) = 0; |
| }; |
| |
| #endif // SHARE_VM_UTILITIES_BITMAP_HPP |