NullPointerException in GPars, Actor
<p>Groovy: 1.8.6</p>

<p>GPars: 0.12 or 1.2.1</p>

<p>OS: Ubuntu 14.04 LTS</p>

<pre><code>@Grab(group='org.codehaus.gpars', module='gpars', version='0.12')
import groovyx.gpars.actor.Actor


import groovyx.gpars.actor.Actors


def a = 1
def b = 100000

def reactor2 = Actors.reactor {
    println " $it"
}

def reactor1 = Actors.reactor {
    println "$it"
    reactor2 &lt;&lt; it
}

Actor actor = Actors.actor {
    (a..b).each {reactor1 &lt;&lt; it}
}

actor.join()

reactor1.stop()
reactor1.join()

reactor2.stop()
reactor2.join()
</code></pre>

<p>When this code is executed, NullPointerException is occurred　often. Wider and wider the range of a and b is, more and more easily this error is occurred. But the error is never occurred when the range is limited.</p>

<p>I cannot understand why the error is occurred.</p>