Solution to large dictionaries not released to memory: Run a separate process

gistfile1.txt

import random
import optparse
import gc

from flask import redirect, Flask
from memory_profiler import memory_usage
from multiprocessing import Process

# Create flask app
app = Flask(__name__)
app.debug = True

@app.route('/')
def hello_world():
	###
	# The test:
	# Generate a 2440 mb dictionary and return a blank page.
	###
	def separate_process():
		large_dict = {}
		for x in xrange(125000):
			large_row = {}
			for y in xrange(125):
				large_row[random.randint(1, 10000000000)] = random.randint(1, 10000000000)
			large_dict[random.randint(1, 10000000000)] = large_row

	p = Process(target=separate_process)
	p.start()
	p.join() # this blocks until the process terminates
	
	return ''

@app.after_request
def after(response):
	print memory_usage(-1, interval=.2, timeout=1), "after request"
	return response
	
def main():
	app.config['SECRET_KEY'] = "BLAH"
	
	parser = optparse.OptionParser()
	parser.add_option("--host", default="0.0.0.0") # can't use -h, it's already taken by help
	parser.add_option("-p", "--port", default="5123")
	options, args = parser.parse_args()

	if len(args) > 0:
		parser.error("Unexpected arguments: %s" % args)

	app.run(host=options.host, port=int(options.port))

if __name__ == '__main__':
	# Start app
	main()