-namespace factor
-{
+namespace factor {
const int mark_bits_granularity = sizeof(cell) * 8;
const int mark_bits_mask = sizeof(cell) * 8 - 1;
-template<typename Block> struct mark_bits {
- cell size;
- cell start;
- cell bits_size;
- cell *marked;
- cell *forwarding;
-
- void clear_mark_bits()
- {
- memset(marked,0,bits_size * sizeof(cell));
- }
-
- void clear_forwarding()
- {
- memset(forwarding,0,bits_size * sizeof(cell));
- }
-
- explicit mark_bits(cell size_, cell start_) :
- size(size_),
- start(start_),
- bits_size(size / data_alignment / mark_bits_granularity),
- marked(new cell[bits_size]),
- forwarding(new cell[bits_size])
- {
- clear_mark_bits();
- clear_forwarding();
- }
-
- ~mark_bits()
- {
- delete[] marked;
- marked = NULL;
- delete[] forwarding;
- forwarding = NULL;
- }
-
- cell block_line(const Block *address)
- {
- return (((cell)address - start) / data_alignment);
- }
-
- Block *line_block(cell line)
- {
- return (Block *)(line * data_alignment + start);
- }
-
- std::pair<cell,cell> bitmap_deref(const Block *address)
- {
- cell line_number = block_line(address);
- cell word_index = (line_number / mark_bits_granularity);
- cell word_shift = (line_number & mark_bits_mask);
- return std::make_pair(word_index,word_shift);
- }
-
- bool bitmap_elt(cell *bits, const Block *address)
- {
- std::pair<cell,cell> position = bitmap_deref(address);
- return (bits[position.first] & ((cell)1 << position.second)) != 0;
- }
-
- Block *next_block_after(const Block *block)
- {
- return (Block *)((cell)block + block->size());
- }
-
- void set_bitmap_range(cell *bits, const Block *address)
- {
- std::pair<cell,cell> start = bitmap_deref(address);
- std::pair<cell,cell> end = bitmap_deref(next_block_after(address));
-
- cell start_mask = ((cell)1 << start.second) - 1;
- cell end_mask = ((cell)1 << end.second) - 1;
-
- if(start.first == end.first)
- bits[start.first] |= start_mask ^ end_mask;
- else
- {
-#ifdef FACTOR_DEBUG
- FACTOR_ASSERT(start.first < bits_size);
-#endif
- bits[start.first] |= ~start_mask;
-
- for(cell index = start.first + 1; index < end.first; index++)
- bits[index] = (cell)-1;
-
- if(end_mask != 0)
- {
-#ifdef FACTOR_DEBUG
- FACTOR_ASSERT(end.first < bits_size);
-#endif
- bits[end.first] |= end_mask;
- }
- }
- }
-
- bool marked_p(const Block *address)
- {
- return bitmap_elt(marked,address);
- }
-
- void set_marked_p(const Block *address)
- {
- set_bitmap_range(marked,address);
- }
-
- /* The eventual destination of a block after compaction is just the number
- of marked blocks before it. Live blocks must be marked on entry. */
- void compute_forwarding()
- {
- cell accum = 0;
- for(cell index = 0; index < bits_size; index++)
- {
- forwarding[index] = accum;
- accum += popcount(marked[index]);
- }
- }
-
- /* We have the popcount for every mark_bits_granularity entries; look
- up and compute the rest */
- Block *forward_block(const Block *original)
- {
-#ifdef FACTOR_DEBUG
- FACTOR_ASSERT(marked_p(original));
-#endif
- std::pair<cell,cell> position = bitmap_deref(original);
- cell offset = (cell)original & (data_alignment - 1);
-
- cell approx_popcount = forwarding[position.first];
- cell mask = ((cell)1 << position.second) - 1;
-
- cell new_line_number = approx_popcount + popcount(marked[position.first] & mask);
- Block *new_block = (Block*)((char*)line_block(new_line_number) + offset);
-#ifdef FACTOR_DEBUG
- FACTOR_ASSERT(new_block <= original);
-#endif
- return new_block;
- }
-
- Block *next_unmarked_block_after(const Block *original)
- {
- std::pair<cell,cell> position = bitmap_deref(original);
- cell bit_index = position.second;
-
- for(cell index = position.first; index < bits_size; index++)
- {
- cell mask = ((fixnum)marked[index] >> bit_index);
- if(~mask)
- {
- /* Found an unmarked block on this page.
- Stop, it's hammer time */
- cell clear_bit = rightmost_clear_bit(mask);
- return line_block(index * mark_bits_granularity + bit_index + clear_bit);
- }
- else
- {
- /* No unmarked blocks on this page.
- Keep looking */
- bit_index = 0;
- }
- }
-
- /* No unmarked blocks were found */
- return (Block *)(this->start + this->size);
- }
-
- Block *next_marked_block_after(const Block *original)
- {
- std::pair<cell,cell> position = bitmap_deref(original);
- cell bit_index = position.second;
-
- for(cell index = position.first; index < bits_size; index++)
- {
- cell mask = (marked[index] >> bit_index);
- if(mask)
- {
- /* Found an marked block on this page.
- Stop, it's hammer time */
- cell set_bit = rightmost_set_bit(mask);
- return line_block(index * mark_bits_granularity + bit_index + set_bit);
- }
- else
- {
- /* No marked blocks on this page.
- Keep looking */
- bit_index = 0;
- }
- }
-
- /* No marked blocks were found */
- return (Block *)(this->start + this->size);
- }
-
- cell unmarked_block_size(Block *original)
- {
- Block *next_marked = next_marked_block_after(original);
- return ((char *)next_marked - (char *)original);
- }
+struct mark_bits {
+ cell size;
+ cell start;
+ cell bits_size;
+ cell* marked;
+ cell* forwarding;
+
+ void clear_mark_bits() { memset(marked, 0, bits_size * sizeof(cell)); }
+
+ void clear_forwarding() { memset(forwarding, 0, bits_size * sizeof(cell)); }
+
+ mark_bits(cell size, cell start)
+ : size(size),
+ start(start),
+ bits_size(size / data_alignment / mark_bits_granularity),
+ marked(new cell[bits_size]),
+ forwarding(new cell[bits_size]) {
+ clear_mark_bits();
+ clear_forwarding();
+ }
+
+ ~mark_bits() {
+ delete[] marked;
+ marked = NULL;
+ delete[] forwarding;
+ forwarding = NULL;
+ }
+
+ cell block_line(cell address) {
+ return (address - start) / data_alignment;
+ }
+
+ cell line_block(cell line) {
+ return line * data_alignment + start;
+ }
+
+ std::pair<cell, cell> bitmap_deref(const cell address) {
+ cell line_number = block_line(address);
+ cell word_index = (line_number / mark_bits_granularity);
+ cell word_shift = (line_number & mark_bits_mask);
+ return std::make_pair(word_index, word_shift);
+ }
+
+ bool bitmap_elt(cell* bits, const cell address) {
+ std::pair<cell, cell> position = bitmap_deref(address);
+ return (bits[position.first] & ((cell)1 << position.second)) != 0;
+ }
+
+ void set_bitmap_range(cell* bits, const cell address, const cell size) {
+ std::pair<cell, cell> start = bitmap_deref(address);
+ std::pair<cell, cell> end = bitmap_deref(address + size);
+
+ cell start_mask = ((cell)1 << start.second) - 1;
+ cell end_mask = ((cell)1 << end.second) - 1;
+
+ if (start.first == end.first)
+ bits[start.first] |= start_mask ^ end_mask;
+ else {
+ FACTOR_ASSERT(start.first < bits_size);
+ bits[start.first] |= ~start_mask;
+
+ for (cell index = start.first + 1; index < end.first; index++)
+ bits[index] = (cell)-1;
+
+ if (end_mask != 0) {
+ FACTOR_ASSERT(end.first < bits_size);
+ bits[end.first] |= end_mask;
+ }
+ }
+ }
+
+ bool marked_p(const cell address) { return bitmap_elt(marked, address); }
+
+ void set_marked_p(const cell address, const cell size) {
+ set_bitmap_range(marked, address, size);
+ }
+
+ // The eventual destination of a block after compaction is just the number
+ // of marked blocks before it. Live blocks must be marked on entry.
+ void compute_forwarding() {
+ cell accum = 0;
+ for (cell index = 0; index < bits_size; index++) {
+ forwarding[index] = accum;
+ accum += popcount(marked[index]);
+ }
+ }
+
+ // We have the popcount for every mark_bits_granularity entries; look
+ // up and compute the rest
+ cell forward_block(const cell original) {
+ FACTOR_ASSERT(marked_p(original));
+ std::pair<cell, cell> position = bitmap_deref(original);
+ cell offset = original & (data_alignment - 1);
+
+ cell approx_popcount = forwarding[position.first];
+ cell mask = ((cell)1 << position.second) - 1;
+
+ cell new_line_number =
+ approx_popcount + popcount(marked[position.first] & mask);
+ cell new_block = line_block(new_line_number) + offset;
+ FACTOR_ASSERT(new_block <= original);
+ return new_block;
+ }
+
+ cell next_unmarked_block_after(const cell original) {
+ std::pair<cell, cell> position = bitmap_deref(original);
+ cell bit_index = position.second;
+
+ for (cell index = position.first; index < bits_size; index++) {
+ cell mask = ((fixnum)marked[index] >> bit_index);
+ if (~mask) {
+ // Found an unmarked block on this page. Stop, it's hammer time
+ cell clear_bit = rightmost_clear_bit(mask);
+ return line_block(index * mark_bits_granularity + bit_index +
+ clear_bit);
+ }
+ // No unmarked blocks on this page. Keep looking
+ bit_index = 0;
+ }
+
+ // No unmarked blocks were found
+ return this->start + this->size;
+ }
+
+ cell next_marked_block_after(const cell original) {
+ std::pair<cell, cell> position = bitmap_deref(original);
+ cell bit_index = position.second;
+
+ for (cell index = position.first; index < bits_size; index++) {
+ cell mask = (marked[index] >> bit_index);
+ if (mask) {
+ // Found an marked block on this page. Stop, it's hammer time
+ cell set_bit = rightmost_set_bit(mask);
+ return line_block(index * mark_bits_granularity + bit_index + set_bit);
+ }
+ // No marked blocks on this page. Keep looking
+ bit_index = 0;
+ }
+
+ // No marked blocks were found
+ return this->start + this->size;
+ }
+
+ cell unmarked_block_size(cell original) {
+ cell next_marked = next_marked_block_after(original);
+ return next_marked - original;
+ }
};
}
projects / factor.git / blobdiff