/vm/compaction.cpp
http://github.com/abeaumont/factor · C++ · 366 lines · 280 code · 68 blank · 18 comment · 16 complexity · be31fd90a6c0375e4b0fcb66aaa1a240 MD5 · raw file
- #include "master.hpp"
- namespace factor {
- struct compaction_fixup {
- static const bool translated_code_block_map = false;
- mark_bits<object> *data_forwarding_map;
- mark_bits<code_block> *code_forwarding_map;
- const object **data_finger;
- const code_block **code_finger;
- explicit compaction_fixup(
- mark_bits<object> *data_forwarding_map_,
- mark_bits<code_block> *code_forwarding_map_,
- const object **data_finger_,
- const code_block **code_finger_) :
- data_forwarding_map(data_forwarding_map_),
- code_forwarding_map(code_forwarding_map_),
- data_finger(data_finger_),
- code_finger(code_finger_) {}
- object *fixup_data(object *obj)
- {
- return data_forwarding_map->forward_block(obj);
- }
- code_block *fixup_code(code_block *compiled)
- {
- return code_forwarding_map->forward_block(compiled);
- }
- object *translate_data(const object *obj)
- {
- if(obj < *data_finger)
- return fixup_data((object *)obj);
- else
- return (object *)obj;
- }
- code_block *translate_code(const code_block *compiled)
- {
- if(compiled < *code_finger)
- return fixup_code((code_block *)compiled);
- else
- return (code_block *)compiled;
- }
- cell size(object *obj)
- {
- if(data_forwarding_map->marked_p(obj))
- return obj->size(*this);
- else
- return data_forwarding_map->unmarked_block_size(obj);
- }
- cell size(code_block *compiled)
- {
- if(code_forwarding_map->marked_p(compiled))
- return compiled->size(*this);
- else
- return code_forwarding_map->unmarked_block_size(compiled);
- }
- };
- struct object_compaction_updater {
- factor_vm *parent;
- compaction_fixup fixup;
- object_start_map *starts;
- explicit object_compaction_updater(factor_vm *parent_, compaction_fixup fixup_) :
- parent(parent_),
- fixup(fixup_),
- starts(&parent->data->tenured->starts) {}
- void operator()(object *old_address, object *new_address, cell size)
- {
- slot_visitor<compaction_fixup> slot_forwarder(parent,fixup);
- slot_forwarder.visit_slots(new_address);
- code_block_visitor<compaction_fixup> code_forwarder(parent,fixup);
- code_forwarder.visit_object_code_block(new_address);
- starts->record_object_start_offset(new_address);
- }
- };
- template<typename Fixup>
- struct code_block_compaction_relocation_visitor {
- factor_vm *parent;
- code_block *old_address;
- Fixup fixup;
- explicit code_block_compaction_relocation_visitor(factor_vm *parent_,
- code_block *old_address_,
- Fixup fixup_) :
- parent(parent_),
- old_address(old_address_),
- fixup(fixup_) {}
- void operator()(instruction_operand op)
- {
- cell old_offset = op.rel_offset() + (cell)old_address->entry_point();
- switch(op.rel_type())
- {
- case RT_LITERAL:
- {
- cell value = op.load_value(old_offset);
- if(immediate_p(value))
- op.store_value(value);
- else
- op.store_value(RETAG(fixup.fixup_data(untag<object>(value)),TAG(value)));
- break;
- }
- case RT_ENTRY_POINT:
- case RT_ENTRY_POINT_PIC:
- case RT_ENTRY_POINT_PIC_TAIL:
- case RT_HERE:
- {
- cell value = op.load_value(old_offset);
- cell offset = TAG(value);
- code_block *compiled = (code_block *)UNTAG(value);
- op.store_value((cell)fixup.fixup_code(compiled) + offset);
- break;
- }
- case RT_THIS:
- case RT_CARDS_OFFSET:
- case RT_DECKS_OFFSET:
- parent->store_external_address(op);
- break;
- default:
- op.store_value(op.load_value(old_offset));
- break;
- }
- }
- };
- template<typename Fixup>
- struct code_block_compaction_updater {
- factor_vm *parent;
- Fixup fixup;
- slot_visitor<Fixup> data_forwarder;
- code_block_visitor<Fixup> code_forwarder;
- explicit code_block_compaction_updater(factor_vm *parent_,
- Fixup fixup_,
- slot_visitor<Fixup> data_forwarder_,
- code_block_visitor<Fixup> code_forwarder_) :
- parent(parent_),
- fixup(fixup_),
- data_forwarder(data_forwarder_),
- code_forwarder(code_forwarder_) {}
- void operator()(code_block *old_address, code_block *new_address, cell size)
- {
- data_forwarder.visit_code_block_objects(new_address);
- code_block_compaction_relocation_visitor<Fixup> visitor(parent,old_address,fixup);
- new_address->each_instruction_operand(visitor);
- }
- };
- /* After a compaction, invalidate any code heap roots which are not
- marked, and also slide the valid roots up so that call sites can be updated
- correctly in case an inline cache compilation triggered compaction. */
- void factor_vm::update_code_roots_for_compaction()
- {
- std::vector<code_root *>::const_iterator iter = code_roots.begin();
- std::vector<code_root *>::const_iterator end = code_roots.end();
- mark_bits<code_block> *state = &code->allocator->state;
- for(; iter < end; iter++)
- {
- code_root *root = *iter;
- code_block *block = (code_block *)(root->value & (~data_alignment + 1));
- /* Offset of return address within 16-byte allocation line */
- cell offset = root->value - (cell)block;
- if(root->valid && state->marked_p(block))
- {
- block = state->forward_block(block);
- root->value = (cell)block + offset;
- }
- else
- root->valid = false;
- }
- }
- /* Compact data and code heaps */
- void factor_vm::collect_compact_impl(bool trace_contexts_p)
- {
- gc_event *event = current_gc->event;
- #if defined(FACTOR_DEBUG)
- code->verify_all_blocks_set();
- #endif
- if(event) event->started_compaction();
- tenured_space *tenured = data->tenured;
- mark_bits<object> *data_forwarding_map = &tenured->state;
- mark_bits<code_block> *code_forwarding_map = &code->allocator->state;
- /* Figure out where blocks are going to go */
- data_forwarding_map->compute_forwarding();
- code_forwarding_map->compute_forwarding();
- const object *data_finger = tenured->first_block();
- const code_block *code_finger = code->allocator->first_block();
- compaction_fixup fixup(data_forwarding_map,code_forwarding_map,&data_finger,&code_finger);
- slot_visitor<compaction_fixup> data_forwarder(this,fixup);
- code_block_visitor<compaction_fixup> code_forwarder(this,fixup);
- code_forwarder.visit_code_roots();
- /* Object start offsets get recomputed by the object_compaction_updater */
- data->tenured->starts.clear_object_start_offsets();
- /* Slide everything in tenured space up, and update data and code heap
- pointers inside objects. */
- object_compaction_updater object_updater(this,fixup);
- tenured->compact(object_updater,fixup,&data_finger);
- /* Slide everything in the code heap up, and update data and code heap
- pointers inside code blocks. */
- code_block_compaction_updater<compaction_fixup> code_block_updater(this,fixup,data_forwarder,code_forwarder);
- code->allocator->compact(code_block_updater,fixup,&code_finger);
- data_forwarder.visit_roots();
- if(trace_contexts_p)
- {
- data_forwarder.visit_contexts();
- code_forwarder.visit_context_code_blocks();
- }
- update_code_roots_for_compaction();
- callbacks->update();
- code->initialize_all_blocks_set();
- if(event) event->ended_compaction();
- }
- struct code_compaction_fixup {
- static const bool translated_code_block_map = false;
- mark_bits<code_block> *code_forwarding_map;
- const code_block **code_finger;
- explicit code_compaction_fixup(mark_bits<code_block> *code_forwarding_map_,
- const code_block **code_finger_) :
- code_forwarding_map(code_forwarding_map_),
- code_finger(code_finger_) {}
- object *fixup_data(object *obj)
- {
- return obj;
- }
- code_block *fixup_code(code_block *compiled)
- {
- return code_forwarding_map->forward_block(compiled);
- }
- object *translate_data(const object *obj)
- {
- return fixup_data((object *)obj);
- }
- code_block *translate_code(const code_block *compiled)
- {
- if(compiled < *code_finger)
- return fixup_code((code_block *)compiled);
- else
- return (code_block *)compiled;
- }
- cell size(object *obj)
- {
- return obj->size();
- }
- cell size(code_block *compiled)
- {
- if(code_forwarding_map->marked_p(compiled))
- return compiled->size(*this);
- else
- return code_forwarding_map->unmarked_block_size(compiled);
- }
- };
- struct object_grow_heap_updater {
- code_block_visitor<code_compaction_fixup> code_forwarder;
- explicit object_grow_heap_updater(code_block_visitor<code_compaction_fixup> code_forwarder_) :
- code_forwarder(code_forwarder_) {}
- void operator()(object *obj)
- {
- code_forwarder.visit_object_code_block(obj);
- }
- };
- /* Compact just the code heap, after growing the data heap */
- void factor_vm::collect_compact_code_impl(bool trace_contexts_p)
- {
- /* Figure out where blocks are going to go */
- mark_bits<code_block> *code_forwarding_map = &code->allocator->state;
- code_forwarding_map->compute_forwarding();
- const code_block *code_finger = code->allocator->first_block();
- code_compaction_fixup fixup(code_forwarding_map,&code_finger);
- slot_visitor<code_compaction_fixup> data_forwarder(this,fixup);
- code_block_visitor<code_compaction_fixup> code_forwarder(this,fixup);
- code_forwarder.visit_code_roots();
- if(trace_contexts_p)
- code_forwarder.visit_context_code_blocks();
- /* Update code heap references in data heap */
- object_grow_heap_updater object_updater(code_forwarder);
- each_object(object_updater);
- /* Slide everything in the code heap up, and update code heap
- pointers inside code blocks. */
- code_block_compaction_updater<code_compaction_fixup> code_block_updater(this,fixup,data_forwarder,code_forwarder);
- code->allocator->compact(code_block_updater,fixup,&code_finger);
- update_code_roots_for_compaction();
- callbacks->update();
- code->initialize_all_blocks_set();
- }
- void factor_vm::collect_compact(bool trace_contexts_p)
- {
- collect_mark_impl(trace_contexts_p);
- collect_compact_impl(trace_contexts_p);
-
- if(data->high_fragmentation_p())
- {
- /* Compaction did not free up enough memory. Grow the heap. */
- set_current_gc_op(collect_growing_heap_op);
- collect_growing_heap(0,trace_contexts_p);
- }
- code->flush_icache();
- }
- void factor_vm::collect_growing_heap(cell requested_size, bool trace_contexts_p)
- {
- /* Grow the data heap and copy all live objects to the new heap. */
- data_heap *old = data;
- set_data_heap(data->grow(requested_size));
- collect_mark_impl(trace_contexts_p);
- collect_compact_code_impl(trace_contexts_p);
- code->flush_icache();
- delete old;
- }
- }