#! /usr/bin/env python
# Copyright (c) 2014 KU Leuven, ESAT-STADIUS
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions
# are met:
#
# 1. Redistributions of source code must retain the above copyright
# notice, this list of conditions and the following disclaimer.
#
# 2. Redistributions in binary form must reproduce the above copyright
# notice, this list of conditions and the following disclaimer in the
# documentation and/or other materials provided with the distribution.
#
# 3. Neither name of copyright holders nor the names of its contributors
# may be used to endorse or promote products derived from this software
# without specific prior written permission.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
# ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR
# CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
# EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
# PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
# PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
# LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
# NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
# SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
import threading
import copy
__all__ = ['pmap', 'Future']
def _fun(f, q_in, q_out):
while True:
i, x = q_in.get()
if i is None:
break
value = f(*x)
if hasattr(f, 'call_log'):
k = list(f.call_log.keys())[-1]
q_out.put((i, value, k))
try:
import multiprocessing
# http://stackoverflow.com/a/16071616
[docs] def pmap(f, *args):
"""Parallel map using multiprocessing.
:param f: the callable
:param args: arguments to f, as iterables
:returns: a list containing the results
.. warning::
This function will not work in IPython: https://github.com/claesenm/optunity/issues/8.
.. warning::
Python's multiprocessing library is incompatible with Jython.
"""
nprocs = multiprocessing.cpu_count()
q_in = multiprocessing.Queue(1)
q_out = multiprocessing.Queue()
proc = [multiprocessing.Process(target=_fun, args=(f, q_in, q_out))
for _ in range(nprocs)]
for p in proc:
p.daemon = True
p.start()
sent = [q_in.put((i, x)) for i, x in enumerate(zip(*args))]
[q_in.put((None, None)) for _ in range(nprocs)]
res = [q_out.get() for _ in range(len(sent))]
[p.join() for p in proc]
# FIXME: strong coupling between pmap and functions.logged
if hasattr(f, 'call_log'):
for _, value, k in sorted(res):
f.call_log[k] = value
return [x for i, x, _ in sorted(res)]
# http://code.activestate.com/recipes/84317-easy-threading-with-futures/
[docs] class Future:
def __init__(self,func,*param):
# Constructor
self.__done=0
self.__result=None
self.__status='working'
self.__S=threading.Semaphore(0)
# Run the actual function in a separate thread
self.__T=threading.Thread(target=self.Wrapper, args=(func, param))
self.__T.setName("FutureThread")
self.__T.daemon=True
self.__T.start()
def __repr__(self):
return '<Future at '+hex(id(self))+':'+self.__status+'>'
def __call__(self):
try:
self.__S.acquire()
# We deepcopy __result to prevent accidental tampering with it.
a=copy.deepcopy(self.__result)
finally:
self.__S.release()
return a
[docs] def join(self):
self.__T.join()
[docs] def Wrapper(self, func, param):
# Run the actual function, and let us housekeep around it
# try:
self.__result=func(*param)
# except:
# self.__result="Exception raised within Future"
self.__status=str(self.__result)
self.__S.release()
except ImportError:
pmap = map
Future = None
if __name__ == '__main__':
pass
