Issue #1677694: Refactor and improve test_timeout. Original patch by

Björn Lindqvist.

Lib/test/test_timeout.py

@@ -7,6 +7,7 @@
 skip_expected = not support.is_resource_enabled('network')
 
 import time
+import errno
 import socket
 
 
@@ -101,8 +102,29 @@ class TimeoutTestCase(unittest.TestCase):
     def setUp(self):
         raise NotImplementedError()
 
-    def tearDown(self):
-        self.sock.close()
+    tearDown = setUp
+
+    def _sock_operation(self, count, timeout, method, *args):
+        """
+        Test the specified socket method.
+
+        The method is run at most `count` times and must raise a socket.timeout
+        within `timeout` + self.fuzz seconds.
+        """
+        self.sock.settimeout(timeout)
+        method = getattr(self.sock, method)
+        for i in range(count):
+            t1 = time.time()
+            try:
+                method(*args)
+            except socket.timeout as e:
+                delta = time.time() - t1
+                break
+        else:
+            self.fail('socket.timeout was not raised')
+        # These checks should account for timing unprecision
+        self.assertLess(delta, timeout + self.fuzz)
+        self.assertGreater(delta, timeout - 1.0)
 
 
 class TCPTimeoutTestCase(TimeoutTestCase):
@@ -112,6 +134,9 @@ def setUp(self):
         self.sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
         self.addr_remote = ('www.python.org.', 80)
 
+    def tearDown(self):
+        self.sock.close()
+
     def testConnectTimeout(self):
         # Choose a private address that is unlikely to exist to prevent
         # failures due to the connect succeeding before the timeout.
@@ -119,68 +144,48 @@ def testConnectTimeout(self):
         # with the connect time.  This avoids failing the assertion that
         # the timeout occurred fast enough.
         addr = ('10.0.0.0', 12345)
-
-        # Test connect() timeout
-        _timeout = 0.001
-        self.sock.settimeout(_timeout)
-
-        _t1 = time.time()
-        self.assertRaises(socket.error, self.sock.connect, addr)
-        _t2 = time.time()
-
-        _delta = abs(_t1 - _t2)
-        self.assertTrue(_delta < _timeout + self.fuzz,
-                     "timeout (%g) is more than %g seconds more than expected (%g)"
-                     %(_delta, self.fuzz, _timeout))
+        with support.transient_internet(addr[0]):
+            self._sock_operation(1, 0.001, 'connect', addr)
 
     def testRecvTimeout(self):
         # Test recv() timeout
-        _timeout = 0.02
-
         with support.transient_internet(self.addr_remote[0]):
             self.sock.connect(self.addr_remote)
-            self.sock.settimeout(_timeout)
-
-            _t1 = time.time()
-            self.assertRaises(socket.timeout, self.sock.recv, 1024)
-            _t2 = time.time()
-
-            _delta = abs(_t1 - _t2)
-            self.assertTrue(_delta < _timeout + self.fuzz,
-                         "timeout (%g) is %g seconds more than expected (%g)"
-                         %(_delta, self.fuzz, _timeout))
+            self._sock_operation(1, 1.5, 'recv', 1024)
 
     def testAcceptTimeout(self):
         # Test accept() timeout
-        _timeout = 2
-        self.sock.settimeout(_timeout)
-        # Prevent "Address already in use" socket exceptions
         support.bind_port(self.sock, self.localhost)
         self.sock.listen(5)
-
-        _t1 = time.time()
-        self.assertRaises(socket.error, self.sock.accept)
-        _t2 = time.time()
-
-        _delta = abs(_t1 - _t2)
-        self.assertTrue(_delta < _timeout + self.fuzz,
-                     "timeout (%g) is %g seconds more than expected (%g)"
-                     %(_delta, self.fuzz, _timeout))
+        self._sock_operation(1, 1.5, 'accept')
 
     def testSend(self):
         # Test send() timeout
-        # couldn't figure out how to test it
-        pass
+        with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as serv:
+            support.bind_port(serv, self.localhost)
+            serv.listen(5)
+            self.sock.connect(serv.getsockname())
+            # Send a lot of data in order to bypass buffering in the TCP stack.
+            self._sock_operation(100, 1.5, 'send', b"X" * 200000)
 
     def testSendto(self):
         # Test sendto() timeout
-        # couldn't figure out how to test it
-        pass
+        with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as serv:
+            support.bind_port(serv, self.localhost)
+            serv.listen(5)
+            self.sock.connect(serv.getsockname())
+            # The address argument is ignored since we already connected.
+            self._sock_operation(100, 1.5, 'sendto', b"X" * 200000,
+                                 serv.getsockname())
 
     def testSendall(self):
         # Test sendall() timeout
-        # couldn't figure out how to test it
-        pass
+        with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as serv:
+            support.bind_port(serv, self.localhost)
+            serv.listen(5)
+            self.sock.connect(serv.getsockname())
+            # Send a lot of data in order to bypass buffering in the TCP stack.
+            self._sock_operation(100, 1.5, 'sendall', b"X" * 200000)
 
 
 class UDPTimeoutTestCase(TimeoutTestCase):
@@ -189,21 +194,14 @@ class UDPTimeoutTestCase(TimeoutTestCase):
     def setUp(self):
         self.sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
 
+    def tearDown(self):
+        self.sock.close()
+
     def testRecvfromTimeout(self):
         # Test recvfrom() timeout
-        _timeout = 2
-        self.sock.settimeout(_timeout)
         # Prevent "Address already in use" socket exceptions
         support.bind_port(self.sock, self.localhost)
-
-        _t1 = time.time()
-        self.assertRaises(socket.error, self.sock.recvfrom, 8192)
-        _t2 = time.time()
-
-        _delta = abs(_t1 - _t2)
-        self.assertTrue(_delta < _timeout + self.fuzz,
-                     "timeout (%g) is %g seconds more than expected (%g)"
-                     %(_delta, self.fuzz, _timeout))
+        self._sock_operation(1, 1.5, 'recvfrom', 1024)
 
 
 def test_main():

Misc/NEWS

@@ -159,6 +159,9 @@ Tools/Demos
 Tests
 -----
 
+- Issue #1677694: Refactor and improve test_timeout.  Original patch by
+  Björn Lindqvist.
+
 - Issue #5485: Add tests for the UseForeignDTD method of expat parser objects.
   Patch by Jean-Paul Calderone and Sandro Tosi.