execute functions in a queue
<p>i have a example who should show what i'd like to do</p>

<pre><code>queue = 2

def function():
    print 'abcd'
    time.sleep(3)

def exec_times(times):
    #do something
    function()

def exec_queue(queue):
    #do something
    function()

exec_times(3)
#things need be working while it waiting for the function finish
time.sleep(10)
</code></pre>

<p>the result should be</p>

<pre><code>abcd
abcd

#after finish the first two function executions
abcd
</code></pre>

<p>so, there is a way to do that without use trhead? </p>

<p>i mean some glib function to do this job.</p>
