bpo-38614: Use test.support.SHORT_TIMEOUT constant (GH-17566)

Replace hardcoded timeout constants in tests with SHORT_TIMEOUT of
test.support, so it's easier to ajdust this timeout for all tests at
once.

SHORT_TIMEOUT is 30 seconds by default, but it can be longer
depending on --timeout command line option.

The change makes almost all timeouts longer, except
test_reap_children() of test_support which is made 2x shorter:
SHORT_TIMEOUT should be enough. If this test starts to fail,
LONG_TIMEOUT should be used instead.

Uniformize also "from test import support" import in some test files.

3 files changed, 16 insertions, 11 deletions

diff --git a/Lib/test/test_asyncio/test_events.py b/Lib/test/test_asyncio/test_events.py
index 52467d8..4cbd1ed 100644
--- a/Lib/test/test_asyncio/test_events.py
+++ b/Lib/test/test_asyncio/test_events.py
@@ -1475,12 +1475,12 @@ class EventLoopTestsMixin:
             return len(data)
 
         test_utils.run_until(self.loop, lambda: reader(data) >= 1,
-                             timeout=10)
+                             timeout=support.SHORT_TIMEOUT)
         self.assertEqual(b'1', data)
 
         transport.write(b'2345')
         test_utils.run_until(self.loop, lambda: reader(data) >= 5,
-                             timeout=10)
+                             timeout=support.SHORT_TIMEOUT)
         self.assertEqual(b'12345', data)
         self.assertEqual('CONNECTED', proto.state)
 
@@ -1531,27 +1531,29 @@ class EventLoopTestsMixin:
             return len(data)
 
         write_transport.write(b'1')
-        test_utils.run_until(self.loop, lambda: reader(data) >= 1, timeout=10)
+        test_utils.run_until(self.loop, lambda: reader(data) >= 1,
+                             timeout=support.SHORT_TIMEOUT)
         self.assertEqual(b'1', data)
         self.assertEqual(['INITIAL', 'CONNECTED'], read_proto.state)
         self.assertEqual('CONNECTED', write_proto.state)
 
         os.write(master, b'a')
         test_utils.run_until(self.loop, lambda: read_proto.nbytes >= 1,
-                             timeout=10)
+                             timeout=support.SHORT_TIMEOUT)
         self.assertEqual(['INITIAL', 'CONNECTED'], read_proto.state)
         self.assertEqual(1, read_proto.nbytes)
         self.assertEqual('CONNECTED', write_proto.state)
 
         write_transport.write(b'2345')
-        test_utils.run_until(self.loop, lambda: reader(data) >= 5, timeout=10)
+        test_utils.run_until(self.loop, lambda: reader(data) >= 5,
+                             timeout=support.SHORT_TIMEOUT)
         self.assertEqual(b'12345', data)
         self.assertEqual(['INITIAL', 'CONNECTED'], read_proto.state)
         self.assertEqual('CONNECTED', write_proto.state)
 
         os.write(master, b'bcde')
         test_utils.run_until(self.loop, lambda: read_proto.nbytes >= 5,
-                             timeout=10)
+                             timeout=support.SHORT_TIMEOUT)
         self.assertEqual(['INITIAL', 'CONNECTED'], read_proto.state)
         self.assertEqual(5, read_proto.nbytes)
         self.assertEqual('CONNECTED', write_proto.state)
diff --git a/Lib/test/test_asyncio/test_sslproto.py b/Lib/test/test_asyncio/test_sslproto.py
index 8e9d4c5..c716eac 100644
--- a/Lib/test/test_asyncio/test_sslproto.py
+++ b/Lib/test/test_asyncio/test_sslproto.py
@@ -274,7 +274,8 @@ class BaseStartTLS(func_tests.FunctionalTestCaseMixin):
 
         with self.tcp_server(serve, timeout=self.TIMEOUT) as srv:
             self.loop.run_until_complete(
-                asyncio.wait_for(client(srv.addr), timeout=10))
+                asyncio.wait_for(client(srv.addr),
+                                 timeout=support.SHORT_TIMEOUT))
 
         # No garbage is left if SSL is closed uncleanly
         client_context = weakref.ref(client_context)
@@ -335,7 +336,8 @@ class BaseStartTLS(func_tests.FunctionalTestCaseMixin):
 
         with self.tcp_server(serve, timeout=self.TIMEOUT) as srv:
             self.loop.run_until_complete(
-                asyncio.wait_for(client(srv.addr), timeout=10))
+                asyncio.wait_for(client(srv.addr),
+                                 timeout=support.SHORT_TIMEOUT))
 
         # No garbage is left for SSL client from loop.create_connection, even
         # if user stores the SSLTransport in corresponding protocol instance
@@ -491,7 +493,8 @@ class BaseStartTLS(func_tests.FunctionalTestCaseMixin):
 
         with self.tcp_server(serve, timeout=self.TIMEOUT) as srv:
             self.loop.run_until_complete(
-                asyncio.wait_for(client(srv.addr), timeout=10))
+                asyncio.wait_for(client(srv.addr),
+                                 timeout=support.SHORT_TIMEOUT))
 
     def test_start_tls_server_1(self):
         HELLO_MSG = b'1' * self.PAYLOAD_SIZE
@@ -619,7 +622,7 @@ class BaseStartTLS(func_tests.FunctionalTestCaseMixin):
                     *addr,
                     ssl=client_sslctx,
                     server_hostname='',
-                    ssl_handshake_timeout=10.0),
+                    ssl_handshake_timeout=support.SHORT_TIMEOUT),
                 0.5)
 
         with self.tcp_server(server,
diff --git a/Lib/test/test_asyncio/utils.py b/Lib/test/test_asyncio/utils.py
index 6d8a6e2..804db91 100644
--- a/Lib/test/test_asyncio/utils.py
+++ b/Lib/test/test_asyncio/utils.py
@@ -107,7 +107,7 @@ def run_briefly(loop):
         gen.close()
 
 
-def run_until(loop, pred, timeout=30):
+def run_until(loop, pred, timeout=support.SHORT_TIMEOUT):
     deadline = time.monotonic() + timeout
     while not pred():
         if timeout is not None: