1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
|
# 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 whrandom
import thread
import time
mutex = thread.allocate_lock()
whmutex = thread.allocate_lock() # for calls to whrandom
running = 0
done = thread.allocate_lock()
done.acquire()
numtasks = 10
def task(ident):
global running
whmutex.acquire()
delay = whrandom.random() * numtasks
whmutex.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:
whmutex.acquire()
delay = whrandom.random() * numtasks
whmutex.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 = running - 1
if running == 0:
done.release()
mutex.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'
|
