Lib/test/test_socket.py

#!/usr/bin/env python

import unittest
from test import test_support

import socket
import select
import time
import thread, threading
import Queue
import sys
from weakref import proxy

PORT = 50007
HOST = 'localhost'
MSG = 'Michael Gilfix was here\n'

class SocketTCPTest(unittest.TestCase):

    def setUp(self):
        self.serv = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
        self.serv.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
        self.serv.bind((HOST, PORT))
        self.serv.listen(1)

    def tearDown(self):
        self.serv.close()
        self.serv = None

class SocketUDPTest(unittest.TestCase):

    def setUp(self):
        self.serv = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
        self.serv.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
        self.serv.bind((HOST, PORT))

    def tearDown(self):
        self.serv.close()
        self.serv = None

class ThreadableTest:
    """Threadable Test class

    The ThreadableTest class makes it easy to create a threaded
    client/server pair from an existing unit test. To create a
    new threaded class from an existing unit test, use multiple
    inheritance:

        class NewClass (OldClass, ThreadableTest):
            pass

    This class defines two new fixture functions with obvious
    purposes for overriding:

        clientSetUp ()
        clientTearDown ()

    Any new test functions within the class must then define
    tests in pairs, where the test name is preceeded with a
    '_' to indicate the client portion of the test. Ex:

        def testFoo(self):
            # Server portion

        def _testFoo(self):
            # Client portion

    Any exceptions raised by the clients during their tests
    are caught and transferred to the main thread to alert
    the testing framework.

    Note, the server setup function cannot call any blocking
    functions that rely on the client thread during setup,
    unless serverExplicityReady() is called just before
    the blocking call (such as in setting up a client/server
    connection and performing the accept() in setUp().
    """

    def __init__(self):
        # Swap the true setup function
        self.__setUp = self.setUp
        self.__tearDown = self.tearDown
        self.setUp = self._setUp
        self.tearDown = self._tearDown

    def serverExplicitReady(self):
        """This method allows the server to explicitly indicate that
        it wants the client thread to proceed. This is useful if the
        server is about to execute a blocking routine that is
        dependent upon the client thread during its setup routine."""
        self.server_ready.set()

    def _setUp(self):
        self.server_ready = threading.Event()
        self.client_ready = threading.Event()
        self.done = threading.Event()
        self.queue = Queue.Queue(1)

        # Do some munging to start the client test.
        methodname = self.id()
        i = methodname.rfind('.')
        methodname = methodname[i+1:]
        test_method = getattr(self, '_' + methodname)
        self.client_thread = thread.start_new_thread(
            self.clientRun, (test_method,))

        self.__setUp()
        if not self.server_ready.isSet():
            self.server_ready.set()
        self.client_ready.wait()

    def _tearDown(self):
        self.__tearDown()
        self.done.wait()

        if not self.queue.empty():
            msg = self.queue.get()
            self.fail(msg)

    def clientRun(self, test_func):
        self.server_ready.wait()
        self.client_ready.set()
        self.clientSetUp()
        if not callable(test_func):
            raise TypeError, "test_func must be a callable function"
        try:
            test_func()
        except Exception, strerror:
            self.queue.put(strerror)
        self.clientTearDown()

    def clientSetUp(self):
        raise NotImplementedError, "clientSetUp must be implemented."

    def clientTearDown(self):
        self.done.set()
        thread.exit()

class ThreadedTCPSocketTest(SocketTCPTest, ThreadableTest):

    def __init__(self, methodName='runTest'):
        SocketTCPTest.__init__(self, methodName=methodName)
        ThreadableTest.__init__(self)

    def clientSetUp(self):
        self.cli = socket.socket(socket.AF_INET, socket.SOCK_STREAM)

    def clientTearDown(self):
        self.cli.close()
        self.cli = None
        ThreadableTest.clientTearDown(self)

class ThreadedUDPSocketTest(SocketUDPTest, ThreadableTest):

    def __init__(self, methodName='runTest'):
        SocketUDPTest.__init__(self, methodName=methodName)
        ThreadableTest.__init__(self)

    def clientSetUp(self):
        self.cli = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)

class SocketConnectedTest(ThreadedTCPSocketTest):

    def __init__(self, methodName='runTest'):
        ThreadedTCPSocketTest.__init__(self, methodName=methodName)

    def setUp(self):
        ThreadedTCPSocketTest.setUp(self)
        # Indicate explicitly we're ready for the client thread to
        # proceed and then perform the blocking call to accept
        self.serverExplicitReady()
        conn, addr = self.serv.accept()
        self.cli_conn = conn

    def tearDown(self):
        self.cli_conn.close()
        self.cli_conn = None
        ThreadedTCPSocketTest.tearDown(self)

    def clientSetUp(self):
        ThreadedTCPSocketTest.clientSetUp(self)
        self.cli.connect((HOST, PORT))
        self.serv_conn = self.cli

    def clientTearDown(self):
        self.serv_conn.close()
        self.serv_conn = None
        ThreadedTCPSocketTest.clientTearDown(self)

class SocketPairTest(unittest.TestCase, ThreadableTest):

    def __init__(self, methodName='runTest'):
        unittest.TestCase.__init__(self, methodName=methodName)
        ThreadableTest.__init__(self)

    def setUp(self):
        self.serv, self.cli = socket.socketpair()

    def tearDown(self):
        self.serv.close()
        self.serv = None

    def clientSetUp(self):
        pass

    def clientTearDown(self):
        self.cli.close()
        self.cli = None
        ThreadableTest.clientTearDown(self)


#######################################################################
## Begin Tests

class GeneralModuleTests(unittest.TestCase):

    def test_weakref(self):
        s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
        p = proxy(s)
        self.assertEqual(p.fileno(), s.fileno())
        s.close()
        s = None
        try:
            p.fileno()
        except ReferenceError:
            pass
        else:
            self.fail('Socket proxy still exists')

    def testSocketError(self):
        # Testing socket module exceptions
        def raise_error(*args, **kwargs):
            raise socket.error
        def raise_herror(*args, **kwargs):
            raise socket.herror
        def raise_gaierror(*args, **kwargs):
            raise socket.gaierror
        self.failUnlessRaises(socket.error, raise_error,
                              "Error raising socket exception.")
        self.failUnlessRaises(socket.error, raise_herror,
                              "Error raising socket exception.")
        self.failUnlessRaises(socket.error, raise_gaierror,
                              "Error raising socket exception.")

    def testCrucialConstants(self):
        # Testing for mission critical constants
        socket.AF_INET
        socket.SOCK_STREAM
        socket.SOCK_DGRAM
        socket.SOCK_RAW
        socket.SOCK_RDM
        socket.SOCK_SEQPACKET
        socket.SOL_SOCKET
        socket.SO_REUSEADDR

    def testHostnameRes(self):
        # Testing hostname resolution mechanisms
        hostname = socket.gethostname()
        try:
            ip = socket.gethostbyname(hostname)
        except socket.error:
            # Probably name lookup wasn't set up right; skip this test
            return
        self.assert_(ip.find('.') >= 0, "Error resolving host to ip.")
        try:
            hname, aliases, ipaddrs = socket.gethostbyaddr(ip)
        except socket.error:
            # Probably a similar problem as above; skip this test
            return
        all_host_names = [hostname, hname] + aliases
        fqhn = socket.getfqdn()
        if not fqhn in all_host_names:
            self.fail("Error testing host resolution mechanisms.")

    def testRefCountGetNameInfo(self):
        # Testing reference count for getnameinfo
        import sys
        if hasattr(sys, "getrefcount"):
            try:
                # On some versions, this loses a reference
                orig = sys.getrefcount(__name__)
                socket.getnameinfo(__name__,0)
            except SystemError:
                if sys.getrefcount(__name__) <> orig:
                    self.fail("socket.getnameinfo loses a reference")

    def testInterpreterCrash(self):
        # Making sure getnameinfo doesn't crash the interpreter
        try:
            # On some versions, this crashes the interpreter.
            socket.getnameinfo(('x', 0, 0, 0), 0)
        except socket.error:
            pass

    def testNtoH(self):
        # This just checks that htons etc. are their own inverse,
        # when looking at the lower 16 or 32 bits.
        sizes = {socket.htonl: 32, socket.ntohl: 32,
                 socket.htons: 16, socket.ntohs: 16}
        for func, size in sizes.items():
            mask = (1L<<size) - 1
            for i in (0, 1, 0xffff, ~0xffff, 2, 0x01234567, 0x76543210):
                self.assertEqual(i & mask, func(func(i&mask)) & mask)

            swapped = func(mask)
            self.assertEqual(swapped & mask, mask)
            self.assertRaises(OverflowError, func, 1L<<34)

    def testGetServBy(self):
        eq = self.assertEqual
        # Find one service that exists, then check all the related interfaces.
        # I've ordered this by protocols that have both a tcp and udp
        # protocol, at least for modern Linuxes.
        if sys.platform in ('linux2', 'freebsd4', 'freebsd5', 'freebsd6',
                            'freebsd7', 'darwin'):
            # avoid the 'echo' service on this platform, as there is an
            # assumption breaking non-standard port/protocol entry
            services = ('daytime', 'qotd', 'domain')
        else:
            services = ('echo', 'daytime', 'domain')
        for service in services:
            try:
                port = socket.getservbyname(service, 'tcp')
                break
            except socket.error:
                pass
        else:
            raise socket.error
        # Try same call with optional protocol omitted
        port2 = socket.getservbyname(service)
        eq(port, port2)
        # Try udp, but don't barf it it doesn't exist
        try:
            udpport = socket.getservbyname(service, 'udp')
        except socket.error:
            udpport = None
        else:
            eq(udpport, port)
        # Now make sure the lookup by port returns the same service name
        eq(socket.getservbyport(port2), service)
        eq(socket.getservbyport(port, 'tcp'), service)
        if udpport is not None:
            eq(socket.getservbyport(udpport, 'udp'), service)

    def testDefaultTimeout(self):
        # Testing default timeout
        # The default timeout should initially be None
        self.assertEqual(socket.getdefaulttimeout(), None)
        s = socket.socket()
        self.assertEqual(s.gettimeout(), None)
        s.close()

        # Set the default timeout to 10, and see if it propagates
        socket.setdefaulttimeout(10)
        self.assertEqual(socket.getdefaulttimeout(), 10)
        s = socket.socket()
        self.assertEqual(s.gettimeout(), 10)
        s.close()

        # Reset the default timeout to None, and see if it propagates
        socket.setdefaulttimeout(None)
        self.assertEqual(socket.getdefaulttimeout(), None)
        s = socket.socket()
        self.assertEqual(s.gettimeout(), None)
        s.close()

        # Check that setting it to an invalid value raises ValueError
        self.assertRaises(ValueError, socket.setdefaulttimeout, -1)

        # Check that setting it to an invalid type raises TypeError
        self.assertRaises(TypeError, socket.setdefaulttimeout, "spam")

    def testIPv4toString(self):
        if not hasattr(socket, 'inet_pton'):
            return # No inet_pton() on this platform
        from socket import inet_aton as f, inet_pton, AF_INET
        g = lambda a: inet_pton(AF_INET, a)

        self.assertEquals('\x00\x00\x00\x00', f('0.0.0.0'))
        self.assertEquals('\xff\x00\xff\x00', f('255.0.255.0'))
        self.assertEquals('\xaa\xaa\xaa\xaa', f('170.170.170.170'))
        self.assertEquals('\x01\x02\x03\x04', f('1.2.3.4'))
        self.assertEquals('\xff\xff\xff\xff', f('255.255.255.255'))

        self.assertEquals('\x00\x00\x00\x00', g('0.0.0.0'))
        self.assertEquals('\xff\x00\xff\x00', g('255.0.255.0'))
        self.assertEquals('\xaa\xaa\xaa\xaa', g('170.170.170.170'))
        self.assertEquals('\xff\xff\xff\xff', g('255.255.255.255'))

    def testIPv6toString(self):
        if not hasattr(socket, 'inet_pton'):
            return # No inet_pton() on this platform
        try:
            from socket import inet_pton, AF_INET6, has_ipv6
            if not has_ipv6:
                return
        except ImportError:
            return
        f = lambda a: inet_pton(AF_INET6, a)

        self.assertEquals('\x00' * 16, f('::'))
        self.assertEquals('\x00' * 16, f('0::0'))
        self.assertEquals('\x00\x01' + '\x00' * 14, f('1::'))
        self.assertEquals(
            '\x45\xef\x76\xcb\x00\x1a\x56\xef\xaf\xeb\x0b\xac\x19\x24\xae\xae',
            f('45ef:76cb:1a:56ef:afeb:bac:1924:aeae')
        )

    def testStringToIPv4(self):
        if not hasattr(socket, 'inet_ntop'):
            return # No inet_ntop() on this platform
        from socket import inet_ntoa as f, inet_ntop, AF_INET
        g = lambda a: inet_ntop(AF_INET, a)

        self.assertEquals('1.0.1.0', f('\x01\x00\x01\x00'))
        self.assertEquals('170.85.170.85', f('\xaa\x55\xaa\x55'))
        self.assertEquals('255.255.255.255', f('\xff\xff\xff\xff'))
        self.assertEquals('1.2.3.4', f('\x01\x02\x03\x04'))

        self.assertEquals('1.0.1.0', g('\x01\x00\x01\x00'))
        self.assertEquals('170.85.170.85', g('\xaa\x55\xaa\x55'))
        self.assertEquals('255.255.255.255', g('\xff\xff\xff\xff'))

    def testStringToIPv6(self):
        if not hasattr(socket, 'inet_ntop'):
            return # No inet_ntop() on this platform
        try:
            from socket import inet_ntop, AF_INET6, has_ipv6
            if not has_ipv6:
                return
        except ImportError:
            return
        f = lambda a: inet_ntop(AF_INET6, a)

        self.assertEquals('::', f('\x00' * 16))
        self.assertEquals('::1', f('\x00' * 15 + '\x01'))
        self.assertEquals(
            'aef:b01:506:1001:ffff:9997:55:170',
            f('\x0a\xef\x0b\x01\x05\x06\x10\x01\xff\xff\x99\x97\x00\x55\x01\x70')
        )

    # XXX The following don't test module-level functionality...

    def testSockName(self):
        # Testing getsockname()
        sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
        sock.bind(("0.0.0.0", PORT+1))
        name = sock.getsockname()
        self.assertEqual(name, ("0.0.0.0", PORT+1))

    def testGetSockOpt(self):
        # Testing getsockopt()
        # We know a socket should start without reuse==0
        sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
        reuse = sock.getsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR)
        self.failIf(reuse != 0, "initial mode is reuse")

    def testSetSockOpt(self):
        # Testing setsockopt()
        sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
        sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
        reuse = sock.getsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR)
        self.failIf(reuse == 0, "failed to set reuse mode")

    def testSendAfterClose(self):
        # testing send() after close() with timeout
        sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
        sock.settimeout(1)
        sock.close()
        self.assertRaises(socket.error, sock.send, "spam")

class BasicTCPTest(SocketConnectedTest):

    def __init__(self, methodName='runTest'):
        SocketConnectedTest.__init__(self, methodName=methodName)

    def testRecv(self):
        # Testing large receive over TCP
        msg = self.cli_conn.recv(1024)
        self.assertEqual(msg, MSG)

    def _testRecv(self):
        self.serv_conn.send(MSG)

    def testOverFlowRecv(self):
        # Testing receive in chunks over TCP
        seg1 = self.cli_conn.recv(len(MSG) - 3)
        seg2 = self.cli_conn.recv(1024)
        msg = seg1 + seg2
        self.assertEqual(msg, MSG)

    def _testOverFlowRecv(self):
        self.serv_conn.send(MSG)

    def testRecvFrom(self):
        # Testing large recvfrom() over TCP
        msg, addr = self.cli_conn.recvfrom(1024)
        self.assertEqual(msg, MSG)

    def _testRecvFrom(self):
        self.serv_conn.send(MSG)

    def testOverFlowRecvFrom(self):
        # Testing recvfrom() in chunks over TCP
        seg1, addr = self.cli_conn.recvfrom(len(MSG)-3)
        seg2, addr = self.cli_conn.recvfrom(1024)
        msg = seg1 + seg2
        self.assertEqual(msg, MSG)

    def _testOverFlowRecvFrom(self):
        self.serv_conn.send(MSG)

    def testSendAll(self):
        # Testing sendall() with a 2048 byte string over TCP
        msg = ''
        while 1:
            read = self.cli_conn.recv(1024)
            if not read:
                break
            msg += read
        self.assertEqual(msg, 'f' * 2048)

    def _testSendAll(self):
        big_chunk = 'f' * 2048
        self.serv_conn.sendall(big_chunk)

    def testFromFd(self):
        # Testing fromfd()
        if not hasattr(socket, "fromfd"):
            return # On Windows, this doesn't exist
        fd = self.cli_conn.fileno()
        sock = socket.fromfd(fd, socket.AF_INET, socket.SOCK_STREAM)
        msg = sock.recv(1024)
        self.assertEqual(msg, MSG)

    def _testFromFd(self):
        self.serv_conn.send(MSG)

    def testShutdown(self):
        # Testing shutdown()
        msg = self.cli_conn.recv(1024)
        self.assertEqual(msg, MSG)

    def _testShutdown(self):
        self.serv_conn.send(MSG)
        self.serv_conn.shutdown(2)

class BasicUDPTest(ThreadedUDPSocketTest):

    def __init__(self, methodName='runTest'):
        ThreadedUDPSocketTest.__init__(self, methodName=methodName)

    def testSendtoAndRecv(self):
        # Testing sendto() and Recv() over UDP
        msg = self.serv.recv(len(MSG))
        self.assertEqual(msg, MSG)

    def _testSendtoAndRecv(self):
        self.cli.sendto(MSG, 0, (HOST, PORT))

    def testRecvFrom(self):
        # Testing recvfrom() over UDP
        msg, addr = self.serv.recvfrom(len(MSG))
        self.assertEqual(msg, MSG)

    def _testRecvFrom(self):
        self.cli.sendto(MSG, 0, (HOST, PORT))

class BasicSocketPairTest(SocketPairTest):

    def __init__(self, methodName='runTest'):
        SocketPairTest.__init__(self, methodName=methodName)

    def testRecv(self):
        msg = self.serv.recv(1024)
        self.assertEqual(msg, MSG)

    def _testRecv(self):
        self.cli.send(MSG)

    def testSend(self):
        self.serv.send(MSG)

    def _testSend(self):
        msg = self.cli.recv(1024)
        self.assertEqual(msg, MSG)

class NonBlockingTCPTests(ThreadedTCPSocketTest):

    def __init__(self, methodName='runTest'):
        ThreadedTCPSocketTest.__init__(self, methodName=methodName)

    def testSetBlocking(self):
        # Testing whether set blocking works
        self.serv.setblocking(0)
        start = time.time()
        try:
            self.serv.accept()
        except socket.error:
            pass
        end = time.time()
        self.assert_((end - start) < 1.0, "Error setting non-blocking mode.")

    def _testSetBlocking(self):
        pass

    def testAccept(self):
        # Testing non-blocking accept
        self.serv.setblocking(0)
        try:
            conn, addr = self.serv.accept()
        except socket.error:
            pass
        else:
            self.fail("Error trying to do non-blocking accept.")
        read, write, err = select.select([self.serv], [], [])
        if self.serv in read:
            conn, addr = self.serv.accept()
        else:
            self.fail("Error trying to do accept after select.")

    def _testAccept(self):
        time.sleep(0.1)
        self.cli.connect((HOST, PORT))

    def testConnect(self):
        # Testing non-blocking connect
        conn, addr = self.serv.accept()

    def _testConnect(self):
        self.cli.settimeout(10)
        self.cli.connect((HOST, PORT))

    def testRecv(self):
        # Testing non-blocking recv
        conn, addr = self.serv.accept()
        conn.setblocking(0)
        try:
            msg = conn.recv(len(MSG))
        except socket.error:
            pass
        else:
            self.fail("Error trying to do non-blocking recv.")
        read, write, err = select.select([conn], [], [])
        if conn in read:
            msg = conn.recv(len(MSG))
            self.assertEqual(msg, MSG)
        else:
            self.fail("Error during select call to non-blocking socket.")

    def _testRecv(self):
        self.cli.connect((HOST, PORT))
        time.sleep(0.1)
        self.cli.send(MSG)

class FileObjectClassTestCase(SocketConnectedTest):

    bufsize = -1 # Use default buffer size

    def __init__(self, methodName='runTest'):
        SocketConnectedTest.__init__(self, methodName=methodName)

    def setUp(self):
        SocketConnectedTest.setUp(self)
        self.serv_file = self.cli_conn.makefile('rb', self.bufsize)

    def tearDown(self):
        self.serv_file.close()
        self.assert_(self.serv_file.closed)
        self.serv_file = None
        SocketConnectedTest.tearDown(self)

    def clientSetUp(self):
        SocketConnectedTest.clientSetUp(self)
        self.cli_file = self.serv_conn.makefile('wb')

    def clientTearDown(self):
        self.cli_file.close()
        self.assert_(self.cli_file.closed)
        self.cli_file = None
        SocketConnectedTest.clientTearDown(self)

    def testSmallRead(self):
        # Performing small file read test
        first_seg = self.serv_file.read(len(MSG)-3)
        second_seg = self.serv_file.read(3)
        msg = first_seg + second_seg
        self.assertEqual(msg, MSG)

    def _testSmallRead(self):
        self.cli_file.write(MSG)
        self.cli_file.flush()

    def testFullRead(self):
        # read until EOF
        msg = self.serv_file.read()
        self.assertEqual(msg, MSG)

    def _testFullRead(self):
        self.cli_file.write(MSG)
        self.cli_file.close()

    def testUnbufferedRead(self):
        # Performing unbuffered file read test
        buf = ''
        while 1:
            char = self.serv_file.read(1)
            if not char:
                break
            buf += char
        self.assertEqual(buf, MSG)

    def _testUnbufferedRead(self):
        self.cli_file.write(MSG)
        self.cli_file.flush()

    def testReadline(self):
        # Performing file readline test
        line = self.serv_file.readline()
        self.assertEqual(line, MSG)

    def _testReadline(self):
        self.cli_file.write(MSG)
        self.cli_file.flush()

    def testClosedAttr(self):
        self.assert_(not self.serv_file.closed)

    def _testClosedAttr(self):
        self.assert_(not self.cli_file.closed)

class UnbufferedFileObjectClassTestCase(FileObjectClassTestCase):

    """Repeat the tests from FileObjectClassTestCase with bufsize==0.

    In this case (and in this case only), it should be possible to
    create a file object, read a line from it, create another file
    object, read another line from it, without loss of data in the
    first file object's buffer.  Note that httplib relies on this
    when reading multiple requests from the same socket."""

    bufsize = 0 # Use unbuffered mode

    def testUnbufferedReadline(self):
        # Read a line, create a new file object, read another line with it
        line = self.serv_file.readline() # first line
        self.assertEqual(line, "A. " + MSG) # first line
        self.serv_file = self.cli_conn.makefile('rb', 0)
        line = self.serv_file.readline() # second line
        self.assertEqual(line, "B. " + MSG) # second line

    def _testUnbufferedReadline(self):
        self.cli_file.write("A. " + MSG)
        self.cli_file.write("B. " + MSG)
        self.cli_file.flush()

class LineBufferedFileObjectClassTestCase(FileObjectClassTestCase):

    bufsize = 1 # Default-buffered for reading; line-buffered for writing


class SmallBufferedFileObjectClassTestCase(FileObjectClassTestCase):

    bufsize = 2 # Exercise the buffering code

class TCPTimeoutTest(SocketTCPTest):

    def testTCPTimeout(self):
        def raise_timeout(*args, **kwargs):
            self.serv.settimeout(1.0)
            self.serv.accept()
        self.failUnlessRaises(socket.timeout, raise_timeout,
                              "Error generating a timeout exception (TCP)")

    def testTimeoutZero(self):
        ok = False
        try:
            self.serv.settimeout(0.0)
            foo = self.serv.accept()
        except socket.timeout:
            self.fail("caught timeout instead of error (TCP)")
        except socket.error:
            ok = True
        except:
            self.fail("caught unexpected exception (TCP)")
        if not ok:
            self.fail("accept() returned success when we did not expect it")

class UDPTimeoutTest(SocketTCPTest):

    def testUDPTimeout(self):
        def raise_timeout(*args, **kwargs):
            self.serv.settimeout(1.0)
            self.serv.recv(1024)
        self.failUnlessRaises(socket.timeout, raise_timeout,
                              "Error generating a timeout exception (UDP)")

    def testTimeoutZero(self):
        ok = False
        try:
            self.serv.settimeout(0.0)
            foo = self.serv.recv(1024)
        except socket.timeout:
            self.fail("caught timeout instead of error (UDP)")
        except socket.error:
            ok = True
        except:
            self.fail("caught unexpected exception (UDP)")
        if not ok:
            self.fail("recv() returned success when we did not expect it")

class TestExceptions(unittest.TestCase):

    def testExceptionTree(self):
        self.assert_(issubclass(socket.error, Exception))
        self.assert_(issubclass(socket.herror, socket.error))
        self.assert_(issubclass(socket.gaierror, socket.error))
        self.assert_(issubclass(socket.timeout, socket.error))


def test_main():
    tests = [GeneralModuleTests, BasicTCPTest, TCPTimeoutTest, TestExceptions]
    if sys.platform != 'mac':
        tests.extend([ BasicUDPTest, UDPTimeoutTest ])

    tests.extend([
        NonBlockingTCPTests,
        FileObjectClassTestCase,
        UnbufferedFileObjectClassTestCase,
        LineBufferedFileObjectClassTestCase,
        SmallBufferedFileObjectClassTestCase
    ])
    if hasattr(socket, "socketpair"):
        tests.append(BasicSocketPairTest)
    test_support.run_unittest(*tests)

if __name__ == "__main__":
    test_main()