Andrew, test_cancel2 test fails 1 out of 10 times on my machine (log below).  Could you please take a look?

Also, can you rename sendfile tests to 'test_sock_sendfile_*'?


{pydev} ~/d/p/cpython (master %) » ./python.exe -m test test_asyncio -v -m test_cancel2
== CPython 3.7.0a4+ (heads/master:9d411c119f, Jan 23 2018, 15:12:10) [Clang 9.0.0 (clang-900.0.39.2)]
== Darwin-17.3.0-x86_64-i386-64bit little-endian
== cwd: /Users/yury/dev/pydev/cpython/build/test_python_65406
== CPU count: 8
== encodings: locale=UTF-8, FS=utf-8
Run tests sequentially
0:00:00 load avg: 1.80 [1/1] test_asyncio
test_cancel2 (test.test_asyncio.test_unix_events.SelectorEventLoopUnixSockSendfileTests) ... ERROR

======================================================================
ERROR: test_cancel2 (test.test_asyncio.test_unix_events.SelectorEventLoopUnixSockSendfileTests)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/Users/yury/dev/pydev/cpython/Lib/test/test_asyncio/test_unix_events.py", line 487, in cleanup
    proto.transport.close()
AttributeError: 'NoneType' object has no attribute 'close'

----------------------------------------------------------------------
Ran 1 test in 0.010s

FAILED (errors=1)
Task was destroyed but it is pending!
task: <Task pending coro=<BaseSelectorEventLoop._accept_connection2() done, defined at /Users/yury/dev/pydev/cpython/Lib/asyncio/selector_events.py:200> wait_for=<Future pending cb=[<TaskWakeupMethWrapper object at 0x10731c2e8>()]>>
test test_asyncio failed
test_asyncio failed