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@infinite-Joy
Last active April 22, 2017 07:09
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boilerplate code to implement threading
'''
taken from the raymond hettingers take on threading https://dl.dropboxusercontent.com/u/3967849/pyru/_build/html/threading.html
'''
import threading, time, random, queue
##########################################################################################
# Fuzzing is a technique for amplifying race condition errors to make them more visible
FUZZ = True
def fuzz():
if FUZZ:
time.sleep(random.random())
###########################################################################################
urls = [
'1',
'2',
'3',
'4',
'5'
]
download_queue = queue.Queue()
def download_manager():
'''I have exclusive rights to update the download variable'''
# global counter
while True:
url = download_queue.get()
fuzz()
# response = requests.get(url, timeout=3)
fuzz()
print_queue.put([
'downloaded content from url %s' % url,
'------------------'
])
fuzz()
download_queue.task_done()
t = threading.Thread(target=download_manager)
t.daemon = True
t.start()
del t
###############################################################################
counter = 0
print_queue = queue.Queue()
def print_manager():
'''I have exclusive rights to call the "print" keyword'''
global counter
while True:
job = print_queue.get()
fuzz()
counter += 1
for line in job:
print(line, end='')
fuzz()
print()
fuzz()
# now write to the file
filename = 'somefile.txt'
content = '\n'.join(job)
with open(filename, 'a+') as fw:
fw.write(content)
fw.write('\n')
fuzz()
print_queue.task_done()
fuzz()
t = threading.Thread(target=print_manager)
t.daemon = True
t.start()
del t
####################################################################
def worker(url):
'My job is to increment the counter and print the current count'
download_queue.put(url)
fuzz()
print_queue.put(['Starting up'])
fuzz()
worker_threads = []
for i, url in enumerate(urls):
t = threading.Thread(target=worker, args=(url,))
worker_threads.append(t)
t.start()
fuzz()
download_queue.join()
fuzz()
print_queue.put(['Finishing up'])
fuzz()
print_queue.join()
fuzz()
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