def malloc_varsize_clear(self, typeid, length, size, itemsize,
offset_to_length):
# Only use the nursery if there are not too many items.
if not raw_malloc_usage(itemsize):
too_many_items = False
else:
# The following line is usually constant-folded because both
# min_nursery_size and itemsize are constants (the latter
# due to inlining).
maxlength_for_minimal_nursery = (self.min_nursery_size // 4 //
raw_malloc_usage(itemsize))
# The actual maximum length for our nursery depends on how
# many times our nursery is bigger than the minimal size.
# The computation is done in this roundabout way so that
# only the only remaining computation is the following
# shift.
maxlength = maxlength_for_minimal_nursery << self.nursery_scale
too_many_items = length > maxlength
if (too_many_items or
(raw_malloc_usage(size) > self.lb_young_var_basesize
and raw_malloc_usage(size) > self.largest_young_var_basesize)):
# ^^^ we do two size comparisons; the first one appears redundant,
# but it can be constant-folded if 'size' is a constant; then
# it almost always folds down to False, which kills the
# second comparison as well.
return SemiSpaceGC.malloc_varsize_clear(self, typeid, length, size,
itemsize, offset_to_length)
# with the above checks we know now that totalsize cannot be more
# than about half of the nursery size; in particular, the + and *
# cannot overflow
size_gc_header = self.gcheaderbuilder.size_gc_header
totalsize = size_gc_header + size + itemsize * length
result = self.nursery_free
if raw_malloc_usage(totalsize) > self.nursery_top - result:
result = self.collect_nursery()
llarena.arena_reserve(result, totalsize)
# GCFLAG_NO_YOUNG_PTRS is never set on young objs
self.init_gc_object(result, typeid, flags=0)
(result + size_gc_header + offset_to_length).signed[0] = length
self.nursery_free = result + llarena.round_up_for_allocation(totalsize)
return llmemory.cast_adr_to_ptr(result + size_gc_header,
llmemory.GCREF)
def malloc_varsize_clear(self, typeid, length, size, itemsize,
offset_to_length):
# Only use the nursery if there are not too many items.
if not raw_malloc_usage(itemsize):
too_many_items = False
else:
# The following line is usually constant-folded because both
# min_nursery_size and itemsize are constants (the latter
# due to inlining).
maxlength_for_minimal_nursery = (self.min_nursery_size // 4 //
raw_malloc_usage(itemsize))
# The actual maximum length for our nursery depends on how
# many times our nursery is bigger than the minimal size.
# The computation is done in this roundabout way so that
# only the only remaining computation is the following
# shift.
maxlength = maxlength_for_minimal_nursery << self.nursery_scale
too_many_items = length > maxlength
if (too_many_items or
(raw_malloc_usage(size) > self.lb_young_var_basesize and
raw_malloc_usage(size) > self.largest_young_var_basesize)):
# ^^^ we do two size comparisons; the first one appears redundant,
# but it can be constant-folded if 'size' is a constant; then
# it almost always folds down to False, which kills the
# second comparison as well.
return SemiSpaceGC.malloc_varsize_clear(self, typeid, length, size,
itemsize, offset_to_length)
# with the above checks we know now that totalsize cannot be more
# than about half of the nursery size; in particular, the + and *
# cannot overflow
size_gc_header = self.gcheaderbuilder.size_gc_header
totalsize = size_gc_header + size + itemsize * length
result = self.nursery_free
if raw_malloc_usage(totalsize) > self.nursery_top - result:
result = self.collect_nursery()
llarena.arena_reserve(result, totalsize)
# GCFLAG_NO_YOUNG_PTRS is never set on young objs
self.init_gc_object(result, typeid, flags=0)
(result + size_gc_header + offset_to_length).signed[0] = length
self.nursery_free = result + llarena.round_up_for_allocation(totalsize)
return llmemory.cast_adr_to_ptr(result+size_gc_header, llmemory.GCREF)
