fibra provides a scheduler for cooperative threads, based on Python 
generators. In the context of fibra, generator objects may be referred
to as tasklets.

The plugin system allows the scheduler to grow features, and act as a 
configurable, multipurpose co-routine trampoline.

Plugins:

fibra.plugins.sleep.SleepPlugin
 * allows tasklets to yield a Sleep value, which causes the task to 
 be paused for an amount of time.

fibra.plugins.tasks.TaskPlugin
 * allows tasklets to yield other tasklets, which are then scheduled.
  Also allows tasklets to wait until another tasklet finishes executing,
  or spawn a tasklet when the current tasklet finishes.

fibra.plugins.nonblock.NonBlockPlugin
 * allows a tasklet to momentarily run an iteration in another thread.
 This is useful for running operations which might usually block the
 scheduler and stall other tasklets.


Copyright (c) 2007,2009 Simon Wittber
Copyright (c) 2018 Mario Frasca

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
THE SOFTWARE.