microthreads.py

# https://www.ibm.com/developerworks/jp/linux/library/l-pythrd/
from __future__ import generators;
import time;

threads = []
TIMES = 100000

def stringops():
  for n in xrange(TIMES):
    s = "Mary had a little lamb"
    s = s.upper()
    s = "Mary had a little lamb"
    s = s.lower()
    s = "Mary had a little lamb"
    s = s.replace('a', 'A')

def scheduler():
  for n in xrange(TIMES):
    for thread in threads:
      thread.next()

def upper():
  while 1:
    s = "Mary had a little lamb"
    s = s.upper()
    yield None

def lower():
  for n in xrange(TIMES):
    s = "Mary had a little lamb"
    s = s.lower()
    yield None

def replace():
  while 1:
    s = "Mary had a little lamb"
    s = s.replace('a', 'A')
    yield None

if __name__ == '__main__':
  start = time.clock()
  stringops()
  looptime = time.clock() - start
  print "LOOP TIME: ", looptime
#  global threads
  threads.append(upper())
  threads.append(lower())
  threads.append(replace())
  start = time.clock()
  scheduler()
  threadtime = time.clock() - start
  print "THREAD TIME: ", threadtime