void gc_major() {
#ifdef DEBUG_GC
printf("gc: major collection initiated with end old region %zu\n",
(uintptr_t)(heap->end_old));
#endif
#ifdef DEBUG_HEAP
printf("gc: before heap copy: stage 1 major collection\n");
print_heap();
#endif
// collect from old to reserve
gc_copy(old, reserve);
// adjust heap pointers after collection
heap->end_reserve = heap->reserve_avail;
#ifdef VERIFY_HEAP
verify_reserve_heap();
#endif
#ifdef DEBUG_HEAP
printf("gc: before heap copy: stage 2 major collection\n");
print_heap();
#endif
// block move reserve region back to old heap
heap->old_avail = heap->start;
gc_copy(reserve, old);
nuke_assigns();
// adjust heap pointers after collection
heap->end_old = heap->old_avail;
heap->reserve_avail = heap->end_old;
// reset partition of the reserve and nursery to half of non-old region
heap->end_reserve = heap->end_old + heap_reserve_nursery_midpoint();
heap->nursery_avail = heap->end_reserve;
#ifdef DEBUG_HEAP
printf("gc: after heap copy\n");
print_heap_region();
print_heap();
#endif
}
Object* gc_copy(VM* vm, Object* object) {
ObjectHeader* head = &((ObjectHeader*)object)[-1];
debug("gc copy %p\n",head);
long size;
if (!heap_find(vm, head)) return object;
long* bitmap;
Object* obj;
switch(head->type) {
case OBJ_BOXED_ARRAY:
obj = gc_alloc((ObjectType)head->type, head->size);
size = ((int)head->size) / sizeof(long);
debug("size=%ld\n",size);
for(int i = 0; i < size; i++)
obj->field[i] = gc_copy(vm,object->field[i]);
break;
case OBJ_PAIR:
obj = gc_alloc((ObjectType)head->type, head->size);
obj->fst = gc_copy(vm,object->fst);
obj->snd = gc_copy(vm,object->snd);
break;
case OBJ_UNBOXED_ARRAY:
case OBJ_VM:
obj = gc_alloc((ObjectType)head->type, head->size);
memcpy(obj, object, head->size);
break;
case OBJ_RECORD:
size = ((int)head->size) / sizeof(long);
obj = gc_alloc((ObjectType)head->type, head->size);
memcpy(obj, object, head->size);
bitmap = &object->longs[size];
for(int i = 0; i < size; i++) {
if(bitmap[i/sizeof(long)] & (1 << (i % sizeof(long))))
obj->field[i] = gc_copy(vm,object->field[i]);
}
break;
}
return obj;
}
/******************************************************************
*
* Simple generational collection (appel algorithm)
*
******************************************************************/
void gc_minor() {
#ifdef DEBUG_GC
printf("gc: minor collection initiated with nursery start %zu\n",
(uintptr_t)(heap->end_reserve));
#endif
#ifdef DEBUG_HEAP
printf("gc: before heap copy\n");
print_heap();
#endif
// collect from nursery to reserve
gc_copy(nursery, reserve);
prune_assigns(reserve);
#ifdef VERIFY_HEAP
verify_reserve_heap();
#endif
// adjust heap pointers after collection
// the old region is now redefined to the extent of the used reserve
heap->end_old = heap->reserve_avail;
// reset partition of the reserve and nursery to half of non-old region
heap->end_reserve = heap->end_old + heap_reserve_nursery_midpoint();
heap->nursery_avail = heap->end_reserve;
#ifdef DEBUG_HEAP
printf("gc: after heap copy\n");
print_heap_region();
print_heap();
#endif
}
