Lib.test.test_finalizers.py Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of jython-standalone Show documentation
Jython is an implementation of the high-level, dynamic, object-oriented language Python written in 100% Pure Java, and seamlessly integrated with the Java platform. It thus allows you to run Python on any Java platform.
The newest version!
'''
Created on 06.08.2014
'''

import unittest
import types
import time

from test import test_support


try:
    from java.lang import System
except:
    pass

class GCDetector():
    gcIndex = 0

    def __del__(self):
        GCDetector.gcIndex += 1

maxGCRun = 10

def runGCIfJython():
    try:
        currentIndex = GCDetector.gcIndex
        gcCount = 0
        detector = GCDetector()
        detector = None
        while currentIndex == GCDetector.gcIndex and gcCount < maxGCRun:
            System.gc()
            gcCount += 1
            time.sleep(0.1)
    except:
        pass

finalizeMsgList = []
verbose = False
resurrectedObject_I = None
resurrectedObject_J = None
resurrectedObject_K = None
resurrectedObject_L = None
resurrectedObject_M = None
resurrectedObject_N = None

class ResurrectableDummyClass():

    def __init__(self, name):
        self.name = name
        self.doResurrection = True

    def __str__(self):
        return self.name


class ResurrectableDummyClassNew(object):

    def __init__(self, name):
        self.name = name
        self.doResurrection = True

    def __str__(self):
        return self.name


def __del__I(self):
    global resurrectedObject_I
    finalizeMsgList.append(str(self)+" finalized (ResurrectableDummyClass)")
    if verbose:
        print str(self)+" finalized (ResurrectableDummyClass)"
    if self.doResurrection:
        resurrectedObject_I = self

def __del__J(self):
    global resurrectedObject_J
    finalizeMsgList.append(str(self)+" finalized (ResurrectableDummyClass)")
    if verbose:
        print str(self)+" finalized (ResurrectableDummyClass)"
    if self.doResurrection:
        resurrectedObject_J = self

def __del__K(self):
    global resurrectedObject_K
    finalizeMsgList.append(str(self)+" finalized (ResurrectableDummyClass)")
    if verbose:
        print str(self)+" finalized (ResurrectableDummyClass)"
    if self.doResurrection:
        resurrectedObject_K = self

def __del__L(self):
    global resurrectedObject_L
    finalizeMsgList.append(str(self)+" finalized (ResurrectableDummyClass)")
    if verbose:
        print str(self)+" finalized (ResurrectableDummyClass)"
    if self.doResurrection:
        resurrectedObject_L = self

def __del__M(self):
    global resurrectedObject_M
    finalizeMsgList.append(str(self)+" finalized (ResurrectableDummyClass)")
    if verbose:
        print str(self)+" finalized (ResurrectableDummyClass)"
    if self.doResurrection:
        resurrectedObject_M = self

def __del__N(self):
    global resurrectedObject_N
    finalizeMsgList.append(str(self)+" finalized (ResurrectableDummyClass)")
    if verbose:
        print str(self)+" finalized (ResurrectableDummyClass)"
    if self.doResurrection:
        resurrectedObject_N = self

delI = __del__I
delJ = __del__J
delK = __del__K
delL = __del__L
delM = __del__M
delN = __del__N


class DummyClass():

    def __init__(self, name):
        self.name = name

    def __str__(self):
        return self.name


class DummyClassDel():

    def __init__(self, name):
        self.name = name

    def __str__(self):
        return self.name

    def __del__(self):
        finalizeMsgList.append(str(self)+" finalized (DummyClassDel)")
        if verbose:
            print str(self)+" finalized (DummyClassDel)"


class DummyClassNew(object):

    def __init__(self, name):
        self.name = name

    def __str__(self):
        return self.name

class DummyClassDelNew(object):

    def __init__(self, name):
        self.name = name

    def __str__(self):
        return self.name

    def __del__(self):
        finalizeMsgList.append(str(self)+" finalized (DummyClassDelNew)")
        if verbose:
            print str(self)+" finalized (DummyClassDelNew)"

class DummyFileClassNew(file):

    def __init__(self, name):
        self.name0 = name

    def __str__(self):
        return self.name0

    def __del__(self):
        finalizeMsgList.append(str(self)+" finalized (DummyFileClassNew)")
        if verbose:
            print str(self)+" finalized (DummyFileClassNew)"


def __del__class(self):
    finalizeMsgList.append(str(self)+" finalized (acquired by class)")
    if verbose:
        print str(self)+" finalized (acquired by class)"

def __del__object(self):
    finalizeMsgList.append(str(self)+" finalized (acquired by object)")
    if verbose:
        print str(self)+" finalized (acquired by object)"

def __del__object0():
    finalizeMsgList.append("_ finalized (acquired by object)")
    if verbose:
        print "_ finalized (acquired by object)"

delClass = __del__class
delObject = __del__object
delObject0 = __del__object0

class TestFinalizers(unittest.TestCase):
    def test_finalizer_builtin_oldStyleClass(self):
        A = DummyClassDel("A")
        A = None
        runGCIfJython()
        self.assertIn("A finalized (DummyClassDel)", finalizeMsgList)

    def test_classAcquiresFinalizer_beforeInstanciation_oldStyleClass(self):
        DummyClass.__del__ = delClass
        B = DummyClass("B")
        B = None
        runGCIfJython()
        self.assertIn("B finalized (acquired by class)", finalizeMsgList)
        del DummyClass.__del__

    def test_classAcquiresFinalizer_afterInstanciation_oldStyleClass(self):
        #okay to fail in Jython without the manual __ensure_finalizer__ call
        C = DummyClass("C")
        DummyClass.__del__ = delClass
        try:
            C.__ensure_finalizer__()
        except:
            pass
        C = None
        runGCIfJython()
        self.assertIn("C finalized (acquired by class)", finalizeMsgList)
        del DummyClass.__del__

    def test_instanceAcquiresFinalizer_bound_oldStyleClass(self):
        D = DummyClassDel("D")
        dl = types.MethodType(delObject, D.name)
        D.__del__ = dl
        D = None
        runGCIfJython()
        self.assertNotIn("D finalized (DummyClassDel)", finalizeMsgList)
        self.assertIn("D finalized (acquired by object)", finalizeMsgList)

    def test_finalizer_builtin_newStyleClass(self):
        E = DummyClassDelNew("E")
        E = None
        runGCIfJython()
        self.assertIn("E finalized (DummyClassDelNew)", finalizeMsgList)

    def test_classAcquiresFinalizer_beforeInstanciation_newStyleClass(self):
        DummyClassNew.__del__ = delClass
        F = DummyClassNew("F")
        F = None
        runGCIfJython()
        self.assertIn("F finalized (acquired by class)", finalizeMsgList)
        del DummyClassNew.__del__

    def test_classAcquiresFinalizer_afterInstanciation_newStyleClass(self):
        #okay to fail in Jython without the manual __ensure_finalizer__ call
        G = DummyClassNew("G")
        DummyClassNew.__del__ = delClass
        try:
            G.__ensure_finalizer__()
        except:
            pass
        G = None
        runGCIfJython()
        self.assertIn("G finalized (acquired by class)", finalizeMsgList)
        del DummyClassNew.__del__

    def test_instanceAcquiresFinalizer_bound_newStyleClass(self):
        """
        It seems, CPython prohibits new style instances from acquiring a finalizer.
        """
        H = DummyClassDelNew("H")
        H.__del__ = types.MethodType(delObject, H.name)
        H = None
        runGCIfJython()
        self.assertIn("H finalized (DummyClassDelNew)", finalizeMsgList)
        self.assertNotIn("H finalized (acquired by object)", finalizeMsgList)

    def test_instanceAcquiresFinalizer_bound_newStyleClass2(self):
        """
        In CPython, new style instances can't acquire a finalizer.
        If one calls the instance-acquired __del__ manually, it works, but the gc
        will still call the old one.
        """
        H = DummyClassDelNew("H2")
        H.__del__ = types.MethodType(delObject, H.name)
        H.__del__()
        H = None
        runGCIfJython()
        self.assertIn("H2 finalized (DummyClassDelNew)", finalizeMsgList)
        self.assertIn("H2 finalized (acquired by object)", finalizeMsgList)

    def test_objectResurrection_oldStyleClass(self):
        ResurrectableDummyClass.__del__ = delI
        I = ResurrectableDummyClass("I")
        I = None
        runGCIfJython()
        self.assertIn("I finalized (ResurrectableDummyClass)", finalizeMsgList)
        self.assertEqual(str(resurrectedObject_I), "I")

    def test_objectDoubleResurrection_oldStyleClass(self):
        #okay to fail in Jython without the manual ensureFinalizer calls
        ResurrectableDummyClass.__del__ = delJ
        J = ResurrectableDummyClass("J")
        J = None

        runGCIfJython()
        self.assertIn("J finalized (ResurrectableDummyClass)", finalizeMsgList)
        global resurrectedObject_J
        self.assertEqual(str(resurrectedObject_J), "J")
        J = resurrectedObject_J
        resurrectedObject_J = None
        self.assertIsNone(resurrectedObject_J)
        try:
            #For Jython one can restore the finalizer manually.
            #This is offered as an easy fix if the CPython behavior
            #in this test should be needed for some reason.
            J.__ensure_finalizer__()
        except:
            pass
        J = None

        runGCIfJython()
        self.assertEqual(str(resurrectedObject_J), "J")
        resurrectedObject_J.doResurrection = False
        try:
            #again...
            resurrectedObject_J.__ensure_finalizer__()
        except:
            pass
        resurrectedObject_J = None

        runGCIfJython()
        self.assertIsNone(resurrectedObject_J)


    def test_objectDoubleResurrectionAndFinalize_oldStyleClass(self):
        #okay to fail in Jython without the manual __ensure_finalizer__ calls
        ResurrectableDummyClass.__del__ = delK
        K = ResurrectableDummyClass("K")
        K = None

        runGCIfJython()
        self.assertIn("K finalized (ResurrectableDummyClass)", finalizeMsgList)
        finalizeMsgList.remove("K finalized (ResurrectableDummyClass)")
        self.assertNotIn("K finalized (ResurrectableDummyClass)", finalizeMsgList)
        global resurrectedObject_K
        self.assertEqual(str(resurrectedObject_K), "K")
        K = resurrectedObject_K
        resurrectedObject_K = None
        self.assertIsNone(resurrectedObject_K)
        try:
            K.__ensure_finalizer__()
        except:
            pass
        K = None

        runGCIfJython()
        self.assertIn("K finalized (ResurrectableDummyClass)", finalizeMsgList)
        self.assertEqual(str(resurrectedObject_K), "K")

    def test_objectResurrection_newStyleClass(self):
        ResurrectableDummyClassNew.__del__ = delL
        L = ResurrectableDummyClassNew("L")
        L = None
        runGCIfJython()
        self.assertIn("L finalized (ResurrectableDummyClass)", finalizeMsgList)
        self.assertEqual(str(resurrectedObject_L), "L")

    def test_objectDoubleResurrection_newStyleClass(self):
        #okay to fail in Jython without the manual __ensure_finalizer__ calls
        ResurrectableDummyClassNew.__del__ = delM
        M = ResurrectableDummyClassNew("M")
        M = None

        runGCIfJython()
        self.assertIn("M finalized (ResurrectableDummyClass)", finalizeMsgList)
        global resurrectedObject_M
        self.assertEqual(str(resurrectedObject_M), "M")
        M = resurrectedObject_M
        resurrectedObject_M = None
        self.assertIsNone(resurrectedObject_M, None)
        try:
            M.__ensure_finalizer__()
        except:
            pass
        M = None

        runGCIfJython()
        self.assertEqual(str(resurrectedObject_M), "M")

    def test_objectDoubleResurrectionAndFinalize_newStyleClass(self):
        #okay to fail in Jython without the manual __ensure_finalizer__ calls
        ResurrectableDummyClassNew.__del__ = delN
        N = ResurrectableDummyClassNew("N")
        N = None

        runGCIfJython()
        self.assertIn("N finalized (ResurrectableDummyClass)", finalizeMsgList)
        finalizeMsgList.remove("N finalized (ResurrectableDummyClass)")
        self.assertNotIn("N finalized (ResurrectableDummyClass)", finalizeMsgList)
        global resurrectedObject_N
        self.assertEqual(str(resurrectedObject_N), "N")
        N = resurrectedObject_N
        resurrectedObject_N = None
        self.assertIsNone(resurrectedObject_N)
        try:
            N.__ensure_finalizer__()
        except:
            pass
        N = None

        runGCIfJython()
        self.assertIn("N finalized (ResurrectableDummyClass)", finalizeMsgList)
        self.assertEqual(str(resurrectedObject_N), "N")

    def test_file_overwrite_del(self):
        O = DummyFileClassNew("O")
        O = None

        runGCIfJython()
        self.assertIn("O finalized (DummyFileClassNew)", finalizeMsgList)


def test_main():
    test_support.run_unittest(TestFinalizers)

if __name__ == '__main__':
    test_main()