Python SemiSpaceGC.malloc_varsize_clear方法代码示例

# 需要导入模块: from pypy.rpython.memory.gc.semispace import SemiSpaceGC [as 别名]
# 或者: from pypy.rpython.memory.gc.semispace.SemiSpaceGC import malloc_varsize_clear [as 别名]
 def coalloc_varsize_clear(self, coallocator, typeid,
                           length, size, itemsize,
                           offset_to_length):
     if self.is_in_nursery(coallocator):
         return self.malloc_varsize_clear(typeid, length, size, itemsize,
                                          offset_to_length, True, False)
     else:
         return SemiSpaceGC.malloc_varsize_clear(self, typeid, length, size,
                                                 itemsize, offset_to_length,
                                                 True, False)

# 需要导入模块: from pypy.rpython.memory.gc.semispace import SemiSpaceGC [as 别名]
# 或者: from pypy.rpython.memory.gc.semispace.SemiSpaceGC import malloc_varsize_clear [as 别名]
    def malloc_varsize_clear(self, typeid, length, size, itemsize,
                             offset_to_length, can_collect,
                             has_finalizer=False):
        # 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 (has_finalizer or not can_collect or
            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,
                                                    can_collect, has_finalizer)
        # 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)

# 需要导入模块: from pypy.rpython.memory.gc.semispace import SemiSpaceGC [as 别名]
# 或者: from pypy.rpython.memory.gc.semispace.SemiSpaceGC import malloc_varsize_clear [as 别名]
    def malloc_varsize_clear(self, typeid, length, size, itemsize,
                             offset_to_length, can_collect,
                             has_finalizer=False):
        if has_finalizer or not can_collect:
            return SemiSpaceGC.malloc_varsize_clear(self, typeid, length, size,
                                                    itemsize, offset_to_length,
                                                    can_collect, has_finalizer)
        size_gc_header = self.gcheaderbuilder.size_gc_header
        nonvarsize = size_gc_header + size

        # Compute the maximal length that makes the object still
        # below 'nonlarge_max'.  All the following logic is usually
        # constant-folded because self.nonlarge_max, size and itemsize
        # are all constants (the arguments are constant due to
        # inlining) and self.has_gcptr_in_varsize() is constant-folded.
        if self.has_gcptr_in_varsize(typeid):
            nonlarge_max = self.nonlarge_gcptrs_max
        else:
            nonlarge_max = self.nonlarge_max

        if not raw_malloc_usage(itemsize):
            too_many_items = raw_malloc_usage(nonvarsize) > nonlarge_max
        else:
            maxlength = nonlarge_max - raw_malloc_usage(nonvarsize)
            maxlength = maxlength // raw_malloc_usage(itemsize)
            too_many_items = length > maxlength

        if not too_many_items:
            # With the above checks we know now that totalsize cannot be more
            # than 'nonlarge_max'; in particular, the + and * cannot overflow.
            # Let's try to fit the object in the nursery.
            totalsize = nonvarsize + itemsize * length
            result = self.nursery_free
            if raw_malloc_usage(totalsize) <= self.nursery_top - result:
                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)
        return self.malloc_varsize_slowpath(typeid, length)