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Text File  |  1995-10-22  |  2KB  |  107 lines
  1. # Very rudimentary test of thread module
  2.  
  3. # Create a bunch of threads, let each do some work, wait until all are done
  4.  
  5. import whrandom
  6. import thread
  7. import time
  8.  
  9. mutex = thread.allocate_lock()
  10. whmutex = thread.allocate_lock() # for calls to whrandom
  11. running = 0
  12. done = thread.allocate_lock()
  13. done.acquire()
  14.  
  15. numtasks = 10
  16.  
  17. def task(ident):
  18.     global running
  19.     whmutex.acquire()
  20.     delay = whrandom.random() * numtasks
  21.     whmutex.release()
  22.     print 'task', ident, 'will run for', delay, 'sec'
  23.     time.sleep(delay)
  24.     print 'task', ident, 'done'
  25.     mutex.acquire()
  26.     running = running - 1
  27.     if running == 0:
  28.         done.release()
  29.     mutex.release()
  30.  
  31. next_ident = 0
  32. def newtask():
  33.     global next_ident, running
  34.     mutex.acquire()
  35.     next_ident = next_ident + 1
  36.     print 'creating task', next_ident
  37.     thread.start_new_thread(task, (next_ident,))
  38.     running = running + 1
  39.     mutex.release()
  40.  
  41. for i in range(numtasks):
  42.     newtask()
  43.  
  44. print 'waiting for all tasks to complete'
  45. done.acquire()
  46. print 'all tasks done'
  47.  
  48. class barrier:
  49.     def __init__(self, n):
  50.         self.n = n
  51.         self.waiting = 0
  52.         self.checkin  = thread.allocate_lock()
  53.         self.checkout = thread.allocate_lock()
  54.         self.checkout.acquire()
  55.  
  56.     def enter(self):
  57.         checkin, checkout = self.checkin, self.checkout
  58.  
  59.         checkin.acquire()
  60.         self.waiting = self.waiting + 1
  61.         if self.waiting == self.n:
  62.             self.waiting = self.n - 1
  63.             checkout.release()
  64.             return
  65.         checkin.release()
  66.  
  67.         checkout.acquire()
  68.         self.waiting = self.waiting - 1
  69.         if self.waiting == 0:
  70.             checkin.release()
  71.             return
  72.         checkout.release()
  73.  
  74. numtrips = 3
  75. def task2(ident):
  76.     global running
  77.     for i in range(numtrips):
  78.         if ident == 0:
  79.             # give it a good chance to enter the next
  80.             # barrier before the others are all out
  81.             # of the current one
  82.             delay = 0.001
  83.         else:
  84.             whmutex.acquire()
  85.             delay = whrandom.random() * numtasks
  86.             whmutex.release()
  87.         print 'task', ident, 'will run for', delay, 'sec'
  88.         time.sleep(delay)
  89.         print 'task', ident, 'entering barrier', i
  90.         bar.enter()
  91.         print 'task', ident, 'leaving barrier', i
  92.     mutex.acquire()
  93.     running = running - 1
  94.     if running == 0:
  95.         done.release()
  96.     mutex.release()
  97.  
  98. print '\n*** Barrier Test ***'
  99. if done.acquire(0):
  100.     raise ValueError, "'done' should have remained acquired"
  101. bar = barrier(numtasks)
  102. running = numtasks
  103. for i in range(numtasks):
  104.     thread.start_new_thread(task2, (i,))
  105. done.acquire()
  106. print 'all tasks done'
  107.