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# Very rudimentary test of thread module
# Create a bunch of threads, let each do some work, wait until all are done
from test_support import verbose
import random
import thread
import time
mutex = thread.allocate_lock()
rmutex = thread.allocate_lock() # for calls to random
running = 0
done = thread.allocate_lock()
done.acquire()
numtasks = 10
def task(ident):
global running
rmutex.acquire()
delay = random.random() * numtasks
rmutex.release()
if verbose:
print 'task', ident, 'will run for', round(delay, 1), 'sec'
time.sleep(delay)
if verbose:
print 'task', ident, 'done'
mutex.acquire()
running = running - 1
if running == 0:
done.release()
mutex.release()
next_ident = 0
def newtask():
global next_ident, running
mutex.acquire()
next_ident = next_ident + 1
if verbose:
print 'creating task', next_ident
thread.start_new_thread(task, (next_ident,))
running = running + 1
mutex.release()
for i in range(numtasks):
newtask()
print 'waiting for all tasks to complete'
done.acquire()
print 'all tasks done'
class barrier:
def __init__(self, n):
self.n = n
self.waiting = 0
self.checkin = thread.allocate_lock()
self.checkout = thread.allocate_lock()
self.checkout.acquire()
def enter(self):
checkin, checkout = self.checkin, self.checkout
checkin.acquire()
self.waiting = self.waiting + 1
if self.waiting == self.n:
self.waiting = self.n - 1
checkout.release()
return
checkin.release()
checkout.acquire()
self.waiting = self.waiting - 1
if self.waiting == 0:
checkin.release()
return
checkout.release()
numtrips = 3
def task2(ident):
global running
for i in range(numtrips):
if ident == 0:
# give it a good chance to enter the next
# barrier before the others are all out
# of the current one
delay = 0.001
else:
rmutex.acquire()
delay = random.random() * numtasks
rmutex.release()
if verbose:
print 'task', ident, 'will run for', round(delay, 1), 'sec'
time.sleep(delay)
if verbose:
print 'task', ident, 'entering barrier', i
bar.enter()
if verbose:
print 'task', ident, 'leaving barrier', i
mutex.acquire()
running -= 1
# Must release mutex before releasing done, else the main thread can
# exit and set mutex to None as part of global teardown; then
# mutex.release() raises AttributeError.
finished = running == 0
mutex.release()
if finished:
done.release()
print '\n*** Barrier Test ***'
if done.acquire(0):
raise ValueError, "'done' should have remained acquired"
bar = barrier(numtasks)
running = numtasks
for i in range(numtasks):
thread.start_new_thread(task2, (i,))
done.acquire()
print 'all tasks done'
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