bpo-34932: Add socket.TCP_KEEPALIVE for macOS (GH-25079)

(cherry picked from commit d59d737)

Co-authored-by: Shane Harvey <[email protected]>

Author: miss-islington

Doc/library/socket.rst

@@ -381,6 +381,8 @@ Constants
 
    .. versionchanged:: 3.10
       ``IP_RECVTOS`` was added.
+       Added ``TCP_KEEPALIVE``. On MacOS this constant can be used in the same
+       way that ``TCP_KEEPIDLE`` is used on Linux.
 
 .. data:: AF_CAN
           PF_CAN

Lib/test/test_socket.py

@@ -6411,6 +6411,12 @@ def test_length_restriction(self):
             sock.bind(("type", "n" * 64))
 
 
+@unittest.skipUnless(sys.platform == 'darwin', 'macOS specific test')
+class TestMacOSTCPFlags(unittest.TestCase):
+    def test_tcp_keepalive(self):
+        self.assertTrue(socket.TCP_KEEPALIVE)
+
+
 @unittest.skipUnless(sys.platform.startswith("win"), "requires Windows")
 class TestMSWindowsTCPFlags(unittest.TestCase):
     knownTCPFlags = {
@@ -6669,6 +6675,7 @@ def test_main():
         SendfileUsingSendfileTest,
     ])
     tests.append(TestMSWindowsTCPFlags)
+    tests.append(TestMacOSTCPFlags)
 
     thread_info = threading_helper.threading_setup()
     support.run_unittest(*tests)

Misc/NEWS.d/next/macOS/2021-03-29-21-11-23.bpo-34932.f3Hdyd.rst

@@ -0,0 +1 @@
+Add socket.TCP_KEEPALIVE support for macOS. Patch by Shane Harvey.

Modules/socketmodule.c

@@ -8158,6 +8158,10 @@ PyInit__socket(void)
 #endif
 #ifdef  TCP_KEEPIDLE
     PyModule_AddIntMacro(m, TCP_KEEPIDLE);
+#endif
+    /* TCP_KEEPALIVE is OSX's TCP_KEEPIDLE equivalent */
+#if defined(__APPLE__) && defined(TCP_KEEPALIVE)
+    PyModule_AddIntMacro(m, TCP_KEEPALIVE);
 #endif
 #ifdef  TCP_KEEPINTVL
     PyModule_AddIntMacro(m, TCP_KEEPINTVL);