Index: Doc/library/socket.rst
===================================================================
--- Doc/library/socket.rst	(revision 76913)
+++ Doc/library/socket.rst	(working copy)
@@ -161,6 +161,23 @@
    generally useful.)
 
 
+.. data:: SOCK_CLOEXEC
+          SOCK_NONBLOCK
+
+   These two constants, if defined, can be combined with the socket types and
+   allow you to set some flags atomically (thus avoiding possible race
+   conditions and the need for separate calls).
+
+   .. seealso::
+
+      `Secure File Descriptor Handling <http://udrepper.livejournal.com/20407.html>`_
+      for a more thorough explanation.
+
+   Availability: Linux >= 2.6.27.
+
+   .. versionadded:: 2.7
+
+
 .. data:: SO_*
           SOMAXCONN
           MSG_*
Index: Lib/test/test_socket.py
===================================================================
--- Lib/test/test_socket.py	(revision 76913)
+++ Lib/test/test_socket.py	(working copy)
@@ -15,6 +15,10 @@
 import array
 from weakref import proxy
 import signal
+try:
+    import fcntl
+except ImportError:
+    fcntl = False
 
 HOST = test_support.HOST
 MSG = 'Michael Gilfix was here\n'
@@ -1319,6 +1323,57 @@
         self.cli.close()
 
 
+@unittest.skipUnless(hasattr(socket, "SOCK_CLOEXEC"),
+                     "SOCK_CLOEXEC not defined")
+@unittest.skipUnless(fcntl, "module fcntl not available")
+class CloexecConstantTest(unittest.TestCase):
+    def test_SOCK_CLOEXEC(self):
+        s = socket.socket(socket.AF_INET,
+                          socket.SOCK_STREAM | socket.SOCK_CLOEXEC)
+        self.assertTrue(s.type & socket.SOCK_CLOEXEC)
+        self.assertTrue(fcntl.fcntl(s, fcntl.F_GETFD) & fcntl.FD_CLOEXEC)
+
+
+@unittest.skipUnless(hasattr(socket, "SOCK_NONBLOCK"),
+                     "SOCK_NONBLOCK not defined")
+class NonblockConstantTest(unittest.TestCase):
+    def checkNonblock(self, s, nonblock=True, timeout=0.0):
+        if nonblock:
+            self.assertTrue(s.type & socket.SOCK_NONBLOCK)
+            self.assertEqual(s.gettimeout(), timeout)
+        else:
+            self.assertFalse(s.type & socket.SOCK_NONBLOCK)
+            self.assertEqual(s.gettimeout(), None)
+
+    def test_SOCK_NONBLOCK(self):
+        # a lot of it seems silly and redundant, but I wanted to test that
+        # changing back and forth worked ok
+        s = socket.socket(socket.AF_INET,
+                          socket.SOCK_STREAM | socket.SOCK_NONBLOCK)
+        self.checkNonblock(s)
+        s.setblocking(1)
+        self.checkNonblock(s, False)
+        s.setblocking(0)
+        self.checkNonblock(s)
+        s.settimeout(None)
+        self.checkNonblock(s, False)
+        s.settimeout(2.0)
+        self.checkNonblock(s, timeout=2.0)
+        s.setblocking(1)
+        self.checkNonblock(s, False)
+        # defaulttimeout
+        t = socket.getdefaulttimeout()
+        socket.setdefaulttimeout(0.0)
+        self.checkNonblock(socket.socket())
+        socket.setdefaulttimeout(None)
+        self.checkNonblock(socket.socket(), False)
+        socket.setdefaulttimeout(2.0)
+        self.checkNonblock(socket.socket(), timeout=2.0)
+        socket.setdefaulttimeout(None)
+        self.checkNonblock(socket.socket(), False)
+        socket.setdefaulttimeout(t)
+
+
 def test_main():
     tests = [GeneralModuleTests, BasicTCPTest, TCPCloserTest, TCPTimeoutTest,
              TestExceptions, BufferIOTest, BasicTCPTest2]
@@ -1336,6 +1391,8 @@
         NetworkConnectionNoServer,
         NetworkConnectionAttributesTest,
         NetworkConnectionBehaviourTest,
+        CloexecConstantTest,
+        NonblockConstantTest,
     ])
     if hasattr(socket, "socketpair"):
         tests.append(BasicSocketPairTest)
Index: Modules/socketmodule.c
===================================================================
--- Modules/socketmodule.c	(revision 76913)
+++ Modules/socketmodule.c	(working copy)
@@ -620,6 +620,13 @@
 #endif
 #endif
 
+#ifdef SOCK_NONBLOCK
+	if (block)
+		s->sock_type &= (~SOCK_NONBLOCK);
+	else
+		s->sock_type |= SOCK_NONBLOCK;
+#endif
+
 	Py_BEGIN_ALLOW_THREADS
 #ifdef __BEOS__
 	block = !block;
@@ -729,12 +736,19 @@
 	s->sock_family = family;
 	s->sock_type = type;
 	s->sock_proto = proto;
-	s->sock_timeout = defaulttimeout;
 
 	s->errorhandler = &set_error;
 
-	if (defaulttimeout >= 0.0)
-		internal_setblocking(s, 0);
+#ifdef SOCK_NONBLOCK
+	if (type & SOCK_NONBLOCK)
+		s->sock_timeout = 0.0;
+	else
+#endif
+	{
+		s->sock_timeout = defaulttimeout;
+		if (defaulttimeout >= 0.0)
+			internal_setblocking(s, 0);
+	}
 
 #ifdef RISCOS
 	if (taskwindow)
@@ -4704,6 +4718,12 @@
 	PyModule_AddIntConstant(m, "SOCK_RDM", SOCK_RDM);
 #endif
 #endif
+#ifdef	SOCK_CLOEXEC
+	PyModule_AddIntConstant(m, "SOCK_CLOEXEC", SOCK_CLOEXEC);
+#endif
+#ifdef	SOCK_NONBLOCK
+	PyModule_AddIntConstant(m, "SOCK_NONBLOCK", SOCK_NONBLOCK);
+#endif
 
 #ifdef	SO_DEBUG
 	PyModule_AddIntConstant(m, "SO_DEBUG", SO_DEBUG);