Still needs better docs.

Improve safety for libuv async and idle watchers.

Fixes #1489.

gevent.pywsgi: Support keep-alive in HTTP/1.0

With tests. Supercedes #1331.

Remove redundant checks for constant values.

Make Semaphores fair.

Preserve order of wakeups. Take steps to avoid going back to the O(n^2) old behaviour, though, much like Greenlet does.

This means we auto-unlink links as we call them. Most users won't notice as that's a very low-level method, but baseserver.py was relying on the same rawlink being called every time a semaphore became ready. That was *a lot*, so this eliminates some calls.

coveralls 1.9 is incompatible with coverage >= 5.0a5

Fix #1464 and fix #1465 by making LockType sleep on failure to non-blocking acquire the lock.

Using sleep doesn't force a trip around the event loop until the switch interval elapses.

More simplification and unification of the file objects

Keeping control this way simplifies and unifies the implementations.

- Fix a concurrency bug in FileObjectPosix that we were hiding with buffering and a RuntimeError.
- Add all the error checking the stdlib does, with a few exceptions that make sense.

See #1441.

And add tests.

Fixes #1441.

Update Python versions, including 3.8 final on Appveyor

Fix pylint 2.4 new warnings.

Attempting to match Python 3.8 fixes in subprocess.py, especially on Windows.

Attempting to fix psutil-related regression in PyPy 7.2

corrected a typo in comments

* Fix tests with TLS1.3

There were hidden assumptions about the order in which greenlets would run.

TLS1.3 changed the handshake in a way that broke those assumptions.

* Attempting to fix the appveyor backdoor test timeouts.

Suspect a buffering issue. Trying to fix by disabling Nagle's algorithm.

Also a cleaner separation of concerns in the backdoor server.

* Brute-force debugging.

* Tweak the backlog and simultaneous accept settings, and drop the extra event listeners we don't need.

* max_accept=1 and dropping the events fixed test__backdoor on windows.

probably it was just the events. test that.

* Brute force debugging for the SSL issues.

* Some of the windows ssl issues may be due to fileno reuse and hence incorrectly multiplexed watchers?

* Even more care with socket lifetimes.

On Python 3.7, use the newer wrapping form that the stdlib uses to create the _sslobj.

* More debugging.

* The preferred method of unwrapping differs on 3.6 and 3.7+

* Checking ordering.

* Partial success, hopefully.

* Lots of progress. Try again.

* More Windows work.

* D'oh. Test cases from 3.7.4 handle some of these issues more gracefully so we will just use them.

* Tweaks.

* Having a hard time getting 3.7 updated on Travis. Try to force the issue.

* Yet another weird error from appveyor.

Add support for Python 3.8b4