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| Dir : //proc/self/root/opt/saltstack/salt/lib/python3.10/site-packages/cherrypy/lib/gctools.py |
import gc
import inspect
import sys
import time
try:
import objgraph
except ImportError:
objgraph = None
import cherrypy
from cherrypy import _cprequest, _cpwsgi
from cherrypy.process.plugins import SimplePlugin
class ReferrerTree(object):
"""An object which gathers all referrers of an object to a given depth."""
peek_length = 40
def __init__(self, ignore=None, maxdepth=2, maxparents=10):
self.ignore = ignore or []
self.ignore.append(inspect.currentframe().f_back)
self.maxdepth = maxdepth
self.maxparents = maxparents
def ascend(self, obj, depth=1):
"""Return a nested list containing referrers of the given object."""
depth += 1
parents = []
# Gather all referrers in one step to minimize
# cascading references due to repr() logic.
refs = gc.get_referrers(obj)
self.ignore.append(refs)
if len(refs) > self.maxparents:
return [('[%s referrers]' % len(refs), [])]
try:
ascendcode = self.ascend.__code__
except AttributeError:
ascendcode = self.ascend.im_func.func_code
for parent in refs:
if inspect.isframe(parent) and parent.f_code is ascendcode:
continue
if parent in self.ignore:
continue
if depth <= self.maxdepth:
parents.append((parent, self.ascend(parent, depth)))
else:
parents.append((parent, []))
return parents
def peek(self, s):
"""Return s, restricted to a sane length."""
if len(s) > (self.peek_length + 3):
half = self.peek_length // 2
return s[:half] + '...' + s[-half:]
else:
return s
def _format(self, obj, descend=True):
"""Return a string representation of a single object."""
if inspect.isframe(obj):
filename, lineno, func, context, index = inspect.getframeinfo(obj)
return "<frame of function '%s'>" % func
if not descend:
return self.peek(repr(obj))
if isinstance(obj, dict):
return '{' + ', '.join(['%s: %s' % (self._format(k, descend=False),
self._format(v, descend=False))
for k, v in obj.items()]) + '}'
elif isinstance(obj, list):
return '[' + ', '.join([self._format(item, descend=False)
for item in obj]) + ']'
elif isinstance(obj, tuple):
return '(' + ', '.join([self._format(item, descend=False)
for item in obj]) + ')'
r = self.peek(repr(obj))
if isinstance(obj, (str, int, float)):
return r
return '%s: %s' % (type(obj), r)
def format(self, tree):
"""Return a list of string reprs from a nested list of referrers."""
output = []
def ascend(branch, depth=1):
for parent, grandparents in branch:
output.append((' ' * depth) + self._format(parent))
if grandparents:
ascend(grandparents, depth + 1)
ascend(tree)
return output
def get_instances(cls):
return [x for x in gc.get_objects() if isinstance(x, cls)]
class RequestCounter(SimplePlugin):
def start(self):
self.count = 0
def before_request(self):
self.count += 1
def after_request(self):
self.count -= 1
request_counter = RequestCounter(cherrypy.engine)
request_counter.subscribe()
def get_context(obj):
if isinstance(obj, _cprequest.Request):
return 'path=%s;stage=%s' % (obj.path_info, obj.stage)
elif isinstance(obj, _cprequest.Response):
return 'status=%s' % obj.status
elif isinstance(obj, _cpwsgi.AppResponse):
return 'PATH_INFO=%s' % obj.environ.get('PATH_INFO', '')
elif hasattr(obj, 'tb_lineno'):
return 'tb_lineno=%s' % obj.tb_lineno
return ''
class GCRoot(object):
"""A CherryPy page handler for testing reference leaks."""
classes = [
(_cprequest.Request, 2, 2,
'Should be 1 in this request thread and 1 in the main thread.'),
(_cprequest.Response, 2, 2,
'Should be 1 in this request thread and 1 in the main thread.'),
(_cpwsgi.AppResponse, 1, 1,
'Should be 1 in this request thread only.'),
]
@cherrypy.expose
def index(self):
return 'Hello, world!'
@cherrypy.expose
def stats(self):
output = ['Statistics:']
for trial in range(10):
if request_counter.count > 0:
break
time.sleep(0.5)
else:
output.append('\nNot all requests closed properly.')
# gc_collect isn't perfectly synchronous, because it may
# break reference cycles that then take time to fully
# finalize. Call it thrice and hope for the best.
gc.collect()
gc.collect()
unreachable = gc.collect()
if unreachable:
if objgraph is not None:
final = objgraph.by_type('Nondestructible')
if final:
objgraph.show_backrefs(final, filename='finalizers.png')
trash = {}
for x in gc.garbage:
trash[type(x)] = trash.get(type(x), 0) + 1
if trash:
output.insert(0, '\n%s unreachable objects:' % unreachable)
trash = [(v, k) for k, v in trash.items()]
trash.sort()
for pair in trash:
output.append(' ' + repr(pair))
# Check declared classes to verify uncollected instances.
# These don't have to be part of a cycle; they can be
# any objects that have unanticipated referrers that keep
# them from being collected.
allobjs = {}
for cls, minobj, maxobj, msg in self.classes:
allobjs[cls] = get_instances(cls)
for cls, minobj, maxobj, msg in self.classes:
objs = allobjs[cls]
lenobj = len(objs)
if lenobj < minobj or lenobj > maxobj:
if minobj == maxobj:
output.append(
'\nExpected %s %r references, got %s.' %
(minobj, cls, lenobj))
else:
output.append(
'\nExpected %s to %s %r references, got %s.' %
(minobj, maxobj, cls, lenobj))
for obj in objs:
if objgraph is not None:
ig = [id(objs), id(inspect.currentframe())]
fname = 'graph_%s_%s.png' % (cls.__name__, id(obj))
objgraph.show_backrefs(
obj, extra_ignore=ig, max_depth=4, too_many=20,
filename=fname, extra_info=get_context)
output.append('\nReferrers for %s (refcount=%s):' %
(repr(obj), sys.getrefcount(obj)))
t = ReferrerTree(ignore=[objs], maxdepth=3)
tree = t.ascend(obj)
output.extend(t.format(tree))
return '\n'.join(output)