factor/vm/aging_collector.cpp

91 lines
2.3 KiB
C++

#include "master.hpp"
namespace factor {
struct to_aging_copier : no_fixup {
aging_space* aging;
tenured_space* tenured;
to_aging_copier(aging_space* aging, tenured_space* tenured)
: aging(aging), tenured(tenured) { }
object* fixup_data(object* obj) {
if (aging->contains_p(obj) || tenured->contains_p(obj)) {
return obj;
}
// Is there another forwarding pointer?
while (obj->forwarding_pointer_p()) {
object* dest = obj->forwarding_pointer();
obj = dest;
}
if (aging->contains_p(obj) || tenured->contains_p(obj)) {
return obj;
}
cell size = obj->size();
object* newpointer = aging->allot(size);
if (!newpointer)
throw must_start_gc_again();
memcpy(newpointer, obj, size);
obj->forward_to(newpointer);
return newpointer;
}
};
void factor_vm::collect_aging() {
// Promote objects referenced from tenured space to tenured space, copy
// everything else to the aging semi-space, and reset the nursery pointer.
{
// Change the op so that if we fail here, an assertion will be raised.
current_gc->op = COLLECT_TO_TENURED_OP;
slot_visitor<from_tenured_refs_copier>
visitor(this, from_tenured_refs_copier(data->tenured, &mark_stack));
gc_event* event = current_gc->event;
if (event)
event->reset_timer();
visitor.visit_cards(data->tenured, card_points_to_aging, 0xff);
if (event) {
event->ended_phase(PHASE_CARD_SCAN);
event->cards_scanned += visitor.cards_scanned;
event->decks_scanned += visitor.decks_scanned;
}
if (event)
event->reset_timer();
visitor.visit_code_heap_roots(&code->points_to_aging);
if (event) {
event->ended_phase(PHASE_CODE_SCAN);
event->code_blocks_scanned += code->points_to_aging.size();
}
visitor.visit_mark_stack(&mark_stack);
}
{
// If collection fails here, do a to_tenured collection.
current_gc->op = COLLECT_AGING_OP;
std::swap(data->aging, data->aging_semispace);
data->reset_aging();
aging_space *aging = data->aging;
slot_visitor<to_aging_copier>
visitor(this, to_aging_copier(aging, data->tenured));
cell scan = aging->start + aging->occupied_space();
visitor.visit_all_roots();
visitor.cheneys_algorithm(aging, scan);
data->reset_nursery();
code->clear_remembered_set();
}
}
}