Class Blocker

source code

object --+
         |
        Blocker

A Blocker object starts life with 'happened = False'. Tasks can ask to be suspended until 'happened = True'. The value is changed by a call to trigger().

Example:

>>> kettle_boiled = tasks.Blocker()
>>> def make_tea():
        print "Get cup"
        print "Add tea leaves"
        yield kettle_boiled
        print "Pour water into cup"
        print "Brew..."
        yield tasks.TimeoutBlocker(120, "Brewing")
        print "Add milk"
        print "Ready!"
>>> tasks.Task(make_tea())

Then elsewhere, later:

       print "Kettle boiled!"
       kettle_boiled.trigger()

You can also yield a list of Blockers. Your function will resume after any one of them is triggered. Use blocker.happened to find out which one(s). Yielding a Blocker that has already happened is the same as yielding None (gives any other Tasks a chance to run, and then continues).