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from mx import Proxy
import sys
cleaned_up = 0
class DataRecord:
a = 2
b = 3
# Make read-only:
def __public_setattr__(self,what,to):
raise Proxy.AccessError,'read-only'
# Cleanup protocol
def __cleanup__(self):
global cleaned_up
print 'cleaning up',self
cleaned_up = 1
o = DataRecord()
# Wrap the instance:
p = Proxy.InstanceProxy(o,('a',))
# Remove o from the accessible system:
del o
print 'Read p.a through Proxy:',p.a
# This will cause an exception, because the object is read-only
if 1:
try:
p.a = 3
except:
pass
else:
raise AssertionError,'should be read-only'
# This will cause an exception, because no access is given to .b
if 1:
try:
p.b
except Proxy.AccessError:
pass
else:
raise AssertionError,'should give no access'
# Cleanup error tracebacks by overwriting the previous error;
# this should remove the reference to p in the traceback of the
# previous exception.
if 1:
try:
1/0
except:
pass
# Deleting the Proxy will also delete the wrapped object, if there
# is no other reference to it in the system. It will invoke
# the __cleanup__ method in that case.
del p
assert cleaned_up
#
# Creating and deleting weak Proxies and their referenced objects
#
d = {}
p = Proxy.WeakProxy(d)
q = Proxy.WeakProxy(d)
del p
del q
del d
d = {}
p = Proxy.WeakProxy(d)
q = Proxy.WeakProxy(d)
del q
del p
del d
d = {}
p = Proxy.WeakProxy(d)
q = Proxy.WeakProxy(d)
del d
del p
del q
d = {}
p = Proxy.WeakProxy(d)
q = Proxy.WeakProxy(d)
del d
del q
del p
d = {}
p = Proxy.WeakProxy(d)
q = Proxy.WeakProxy(d)
del d
Proxy.checkweakrefs()
try:
p[1]
except Proxy.LostReferenceError:
pass
else:
print '*** Phantom object still alive !'
print
print 'Works.'
|
