214 lines
5.3 KiB
C++
214 lines
5.3 KiB
C++
namespace factor
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{
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template<typename Block> struct free_list_allocator {
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cell size;
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cell start;
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cell end;
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free_list free_blocks;
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mark_bits<Block> state;
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explicit free_list_allocator(cell size, cell start);
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void initial_free_list(cell occupied);
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bool contains_p(Block *block);
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Block *first_block();
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Block *last_block();
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Block *next_block_after(Block *block);
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Block *next_allocated_block_after(Block *block);
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bool can_allot_p(cell size);
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Block *allot(cell size);
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void free(Block *block);
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cell occupied_space();
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cell free_space();
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cell largest_free_block();
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cell free_block_count();
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void sweep();
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template<typename Iterator, typename Fixup> void compact(Iterator &iter, Fixup fixup, const Block **finger);
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template<typename Iterator, typename Fixup> void iterate(Iterator &iter, Fixup fixup);
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template<typename Iterator> void iterate(Iterator &iter);
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};
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template<typename Block>
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free_list_allocator<Block>::free_list_allocator(cell size_, cell start_) :
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size(size_),
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start(start_),
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end(start_ + size_),
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state(mark_bits<Block>(size_,start_))
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{
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initial_free_list(0);
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}
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template<typename Block> void free_list_allocator<Block>::initial_free_list(cell occupied)
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{
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free_blocks.initial_free_list(start,end,occupied);
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}
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template<typename Block> bool free_list_allocator<Block>::contains_p(Block *block)
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{
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return ((cell)block - start) < size;
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}
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template<typename Block> Block *free_list_allocator<Block>::first_block()
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{
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return (Block *)start;
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}
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template<typename Block> Block *free_list_allocator<Block>::last_block()
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{
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return (Block *)end;
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}
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template<typename Block> Block *free_list_allocator<Block>::next_block_after(Block *block)
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{
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return (Block *)((cell)block + block->size());
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}
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template<typename Block> Block *free_list_allocator<Block>::next_allocated_block_after(Block *block)
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{
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while(block != this->last_block() && block->free_p())
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{
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free_heap_block *free_block = (free_heap_block *)block;
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block = (object *)((cell)free_block + free_block->size());
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}
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if(block == this->last_block())
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return NULL;
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else
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return block;
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}
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template<typename Block> bool free_list_allocator<Block>::can_allot_p(cell size)
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{
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return free_blocks.can_allot_p(size);
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}
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template<typename Block> Block *free_list_allocator<Block>::allot(cell size)
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{
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size = align(size,data_alignment);
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free_heap_block *block = free_blocks.find_free_block(size);
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if(block)
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{
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block = free_blocks.split_free_block(block,size);
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return (Block *)block;
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}
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else
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return NULL;
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}
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template<typename Block> void free_list_allocator<Block>::free(Block *block)
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{
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free_heap_block *free_block = (free_heap_block *)block;
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free_block->make_free(block->size());
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free_blocks.add_to_free_list(free_block);
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}
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template<typename Block> cell free_list_allocator<Block>::free_space()
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{
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return free_blocks.free_space;
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}
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template<typename Block> cell free_list_allocator<Block>::occupied_space()
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{
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return size - free_blocks.free_space;
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}
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template<typename Block> cell free_list_allocator<Block>::largest_free_block()
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{
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return free_blocks.largest_free_block();
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}
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template<typename Block> cell free_list_allocator<Block>::free_block_count()
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{
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return free_blocks.free_block_count;
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}
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template<typename Block>
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void free_list_allocator<Block>::sweep()
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{
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free_blocks.clear_free_list();
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Block *start = this->first_block();
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Block *end = this->last_block();
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while(start != end)
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{
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/* find next unmarked block */
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start = state.next_unmarked_block_after(start);
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if(start != end)
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{
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/* find size */
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cell size = state.unmarked_block_size(start);
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assert(size > 0);
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free_heap_block *free_block = (free_heap_block *)start;
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free_block->make_free(size);
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free_blocks.add_to_free_list(free_block);
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start = (Block *)((char *)start + size);
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}
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}
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}
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template<typename Block, typename Iterator> struct heap_compactor {
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mark_bits<Block> *state;
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char *address;
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Iterator &iter;
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const Block **finger;
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explicit heap_compactor(mark_bits<Block> *state_, Block *address_, Iterator &iter_, const Block **finger_) :
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state(state_), address((char *)address_), iter(iter_), finger(finger_) {}
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void operator()(Block *block, cell size)
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{
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if(this->state->marked_p(block))
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{
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*finger = (Block *)((char *)block + size);
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memmove((Block *)address,block,size);
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iter(block,(Block *)address,size);
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address += size;
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}
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}
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};
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/* The forwarding map must be computed first by calling
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state.compute_forwarding(). */
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template<typename Block>
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template<typename Iterator, typename Fixup>
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void free_list_allocator<Block>::compact(Iterator &iter, Fixup fixup, const Block **finger)
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{
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heap_compactor<Block,Iterator> compactor(&state,first_block(),iter,finger);
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iterate(compactor,fixup);
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/* Now update the free list; there will be a single free block at
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the end */
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free_blocks.initial_free_list(start,end,(cell)compactor.address - start);
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}
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/* During compaction we have to be careful and measure object sizes differently */
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template<typename Block>
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template<typename Iterator, typename Fixup>
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void free_list_allocator<Block>::iterate(Iterator &iter, Fixup fixup)
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{
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Block *scan = first_block();
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Block *end = last_block();
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while(scan != end)
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{
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cell size = fixup.size(scan);
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Block *next = (Block *)((cell)scan + size);
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if(!scan->free_p()) iter(scan,size);
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scan = next;
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}
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}
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template<typename Block>
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template<typename Iterator>
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void free_list_allocator<Block>::iterate(Iterator &iter)
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{
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iterate(iter,no_fixup());
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}
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}
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