blob: 35e53027592af89043489a65385888ca9d641b94 [file] [log] [blame] [edit]
# Compute and gather statistics about garbage collection in this process.
# This module depends on the CPython gc module and garbage collection behavior.
import gc, logging, pprint
verbose = False
# A mapping from type objects to a count of instances of those types in the
# garbage collectors all objects list on the previous call to
# _log_garbage_collector_stats().
_previous_obj_type_map = {}
# A set of object ids for everything in the all objects list on the
# previous call to _log_garbage_collector_stats().
_previous_obj_ids = set()
def _log_garbage_collector_stats(minimum_count=10):
"""
Log statistics about how many of what type of Python object exist in this
process.
@param minimum_count: The minimum number of instances of a type for it
to be considered worthy of logging.
"""
global _previous_obj_type_map
global _previous_obj_ids
# We get all objects -before- creating any new objects within this function.
# to avoid having our own local instances in the list.
all_objects = gc.get_objects()
obj = None
new_objects = []
try:
obj_type_map = {}
object_ids = set()
for obj in all_objects:
obj_type = type(obj)
obj_type_map.setdefault(obj_type, 0)
obj_type_map[obj_type] += 1
object_ids.add(id(obj))
whats_new_big_str = ''
if verbose and _previous_obj_ids:
new_object_ids = object_ids - _previous_obj_ids
for obj in all_objects:
if id(obj) in new_object_ids:
new_objects.append(obj)
whats_new_big_str = pprint.pformat(new_objects, indent=1)
finally:
# Never keep references to stuff returned by gc.get_objects() around
# or it'll just make the future cyclic gc runs more difficult.
del all_objects
del obj
del new_objects
delta = {}
for obj_type, count in obj_type_map.iteritems():
if obj_type not in _previous_obj_type_map:
delta[obj_type] = count
elif _previous_obj_type_map[obj_type] != count:
delta[obj_type] = count - _previous_obj_type_map[obj_type]
sorted_stats = reversed(sorted(
(count, obj_type) for obj_type, count in obj_type_map.iteritems()))
sorted_delta = reversed(sorted(
(count, obj_type) for obj_type, count in delta.iteritems()))
logging.debug('Garbage collector object type counts:')
for count, obj_type in sorted_stats:
if count >= minimum_count:
logging.debug(' %d\t%s', count, obj_type)
logging.info('Change in object counts since previous GC stats:')
for change, obj_type in sorted_delta:
if obj_type_map[obj_type] > minimum_count:
logging.info(' %+d\t%s\tto %d', change, obj_type,
obj_type_map[obj_type])
if verbose and whats_new_big_str:
logging.debug('Pretty printed representation of the new objects:')
logging.debug(whats_new_big_str)
_previous_obj_type_map = obj_type_map
if verbose:
_previous_obj_ids = object_ids