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#!/usr/bin/env python
"""
Put the machine's CPUs under pressure to increase the likelihood of scheduling
weirdness. Useful for exposing otherwise difficult to hit races in the library.
"""
import ctypes
import multiprocessing
import os
LIBC = ctypes.CDLL('libc.so.6')
sched_yield = LIBC.sched_yield
def burn():
while 1:
a, b, c = os.urandom(3)
n = int(((ord(a) << 16) |
(ord(b) << 8) |
(ord(c) << 0)) / 1.6)
print(n)
for x in xrange(n): pass
sched_yield()
mul = 1.5
count = int(mul * multiprocessing.cpu_count())
print(count)
procs = [multiprocessing.Process(target=burn)
for _ in range(count)]
for i, proc in enumerate(procs):
print([i])
proc.start()
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