Reimplement threading.Lock, RLock, and Condition with libpthread.

The pthreading module provides Lock, RLock, and Condition synchronization objects compatible with Python native threading module. The implementation, however, is based on POSIX thread library as delivered by the libpthread. The provided objects are designed to be a drop-in replacement for their respective threading counterpart.

Take a look at threading.py of Python 2. Notice that Condition.wait() wakes 20 times a second and checks if the event has been set. This CPU hogging has been fixed in Python 3, but is not expected to change during Python 2 lifetime.

Note: Condition object does not provide the n argument for notifying more than one waiter as in the standard interface api. (see https://bugzilla.redhat.com/show_bug.cgi?id=1117950)

To avoid this waste of resources, put in your main module:

import pthreading
pthreading.monkey_patch()

This would hack the Linux-native threading module, and make it use Linux-native POSIX synchronization objects.

To perform pep8 check and run the tests:

tox

To run only pep8 or the tests, specify the tox env:

tox -e test

For more control over the tests, use py.test directly. In this example we are running only the Event tests, using verbose mode, and aborting on the first failure:

py.test -k TestEvent -vx tests.py

In this example we run the tests and create a coverage report in html format:

py.test --cov pthreading --cov pthread --cov-report html tests.py

To view the coverage report, open htmlcov/index.html.

For more info on py.test, please run py.test -h.

The pthreading code was originally written as part of Vdsm by Cyril Plisko, Saggi Mizrahi and others. For questions, comments and patches please contact vdsm-devel.