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"""
Compare the speed of primes sequentially vs. using futures.
"""
import math
import sys
import time
try:
from concurrent.futures import ThreadPoolExecutor
except ImportError:
ThreadPoolExecutor = None
try:
from concurrent.futures import ProcessPoolExecutor
except ImportError:
ProcessPoolExecutor = None
from mpi4py.futures import MPIPoolExecutor
PRIMES = [
112272535095293,
112582705942171,
112272535095293,
115280095190773,
115797848077099,
117450548693743,
993960000099397,
]
def is_prime(n):
if n % 2 == 0:
return False
sqrt_n = math.floor(math.sqrt(n))
for i in range(3, sqrt_n + 1, 2):
if n % i == 0:
return False
return True
def sequential():
return list(map(is_prime, PRIMES))
def with_thread_pool_executor():
if not ThreadPoolExecutor:
return None
with ThreadPoolExecutor(4) as executor:
return list(executor.map(is_prime, PRIMES))
def with_process_pool_executor():
if not ProcessPoolExecutor:
return None
with ProcessPoolExecutor(4) as executor:
return list(executor.map(is_prime, PRIMES))
def with_mpi_pool_executor():
with MPIPoolExecutor(4) as executor:
return list(executor.map(is_prime, PRIMES))
def main():
for name, fn in [
("sequential", sequential),
("threads", with_thread_pool_executor),
("processes", with_process_pool_executor),
("mpi4py", with_mpi_pool_executor),
]:
sys.stdout.write(f"{name.ljust(11)}: ")
sys.stdout.flush()
start = time.time()
result = fn()
if result is None:
sys.stdout.write(" not available\n")
elif result != [True] * len(PRIMES):
sys.stdout.write(" failed\n")
else:
elapsed = time.time() - start
sys.stdout.write(f"{elapsed:5.2f} seconds\n")
sys.stdout.flush()
if __name__ == "__main__":
main()
|
