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