beginner, thread & else

[Gigs_]

can someone explain me this code:
----------------------------------
import thread
stdoutmutex = thread.allocate_lock()
exitmutexes = [0] * 10

def counter(myId, count):
     for i in range(count):
         stdoutmutex.acquire()
         print '[%s] => %s' % (myId, i)
         stdoutmutex.release()
     exitmutexes[myId] = 1  # signal main thread

for i in range(10):
     thread.start_new(counter, (i, 100))

while 0 in exitmutexes:
     pass
print 'Main thread exiting.'
-----------------------------------

thread.start_new(counter, (i, 100)) is running  counter function.
Is counter function and while statement executed in same time (other 
things i understand, but can't get into this)?



thanks