MultiProcessing

Issue:

Hello,

I want to use multiprocessing on SPAMS library to fasten the computations, but the kernel freezes when I use it.

Environment (conda list):

```
$ conda list

# packages in environment at /Users/amirali/anaconda:
#
# Name Version Build Channel
_license 1.1 py35_1
_nb_ext_conf 0.4.0 py35_1
_tflow_select 2.2.0 eigen
absl-py 0.4.1 py35_0
absl-py 0.9.0
aiofiles 0.5.0
aiohttp 3.6.2
alabaster 0.7.12 py_0
anaconda custom py35hd7b5ba2_0
anaconda-clean 1.1.0 py35_1
anaconda-client 1.7.2 py35_0
anaconda-navigator 1.9.2 py35_0
anaconda-project 0.8.4 py_0
appdirs 1.4.3 pyh91ea838_0
appnope 0.1.0 py35hd172556_0
appscript 1.0.1 py35h1de35cc_1
apr 1.6.3 he795440_0
argcomplete 1.11.1 py_0
asn1crypto 0.24.0 py35_0
astor 0.7.1 py35_0
astroid 2.0.4 py35_0
astropy 1.3.2 np112py35_0
astunparse 1.6.3
async-timeout 3.0.1
atomicwrites 1.4.0 py_0
attrs 19.3.0 py_0
automat 0.8.0 py_0
babel 2.8.0 py_0
backcall 0.1.0 py35_0
backports 1.0 py_2
backports.functools_lru_cache 1.6.1 py_0
backports.shutil_get_terminal_size 1.0.0 py35_2
backports.tempfile 1.0 py_1
backports.weakref 1.0rc1
backports.weakref 1.0.post1 py_1
beautifulsoup4 4.6.3 py35_0
bitarray 0.8.3 py35h1de35cc_0
blas 1.1 openblas conda-forge
blaze 0.10.1 py35_0
bleach 3.1.4 py_0
bleach 1.5.0
blosc 1.16.3 hd9629dc_0
bokeh 0.13.0 py35_0
boto 2.49.0 py35_0
bottleneck 1.2.1 np112py35_0
bs4 0.0.1
bzip2 1.0.8 h1de35cc_0
ca-certificates 2020.6.24 0
cachetools 4.1.0
cairo 1.14.12 hc4e6be7_4
certifi 2018.8.24 py35_1
certifi 2018.11.29
cffi 1.11.5 py35h6174b99_1
chardet 3.0.4 py35_1
chest 0.2.3 py_2
click 7.1.2 py_0
cloudpickle 1.4.1 py_0
clyent 1.2.2 py35_1
color 0.1
colorama 0.4.3 py_0
conda 4.5.11 py35_0
conda-build 3.15.1 py35_0
conda-env 2.6.0 1
conda-package-handling 1.0.4 py_0
conda-verify 3.4.2 py_1
configobj 5.0.6 py35_1
constantly 15.1.0 pyh91ea838_0
contextlib2 0.6.0.post1 py_0
cryptography 2.3.1 py35hdbc3d79_0
curl 7.61.1 ha441bb4_0
cycler 0.10.0 py35hb89929e_0
cyrus-sasl 2.1.26 h26aff7b_3
cython 0.28.5 py35h0a44026_0
cytoolz 0.9.0.1 py35h1de35cc_1
dask 0.14.3 py35_1
dask-core 2.6.0 py_0
datashape 0.5.4 py35_1
dbus 1.13.14 h517e14e_0
decorator 4.4.2 py_0
defusedxml 0.6.0 py_0
dill 0.2.8.2 py35_0
dill 0.3.2
distributed 1.16.3 py35_0
Django 1.11.5
docutils 0.14 py35hb13dbd9_0
dynd-python 0.7.2 py35_0
entrypoints 0.2.3 py35_2
enum34 1.1.6
et_xmlfile 1.0.1 py35h40eb147_0
expat 2.2.6 h0a44026_0
fastcache 1.0.2 py35h1de35cc_2
ffmpeg 4.0 h01ea3c9_0
filelock 3.0.12 py_0
flask 1.1.2 py_0
flask-cors 3.0.8 py_0
fontconfig 2.13.0 h5d5b041_1
freetype 2.9.1 hb4e5f40_0
fribidi 1.0.5 h1de35cc_0
future 0.16.0 py35_2
future 0.18.2
gast 0.3.3 py_0
gdk-pixbuf 2.36.9 1 conda-forge
gdown 3.11.1
get_terminal_size 1.0.0 h7520d66_0
gettext 0.19.8.1 h15daf44_3
gevent 1.3.6 py35h1de35cc_0
giflib 5.2.1 h0b31af3_2 conda-forge
glib 2.63.1 hd977a24_0
glob2 0.7 py_0
gmp 6.1.2 hb37e062_1
gmpy2 2.0.8 py35h212fb8a_2
gobject-introspection 1.56.1 py35hfc82f85_2
google-auth 1.16.1
google-auth-oauthlib 0.4.1
google-pasta 0.2.0
googledrivedownloader 0.4
graphite2 1.3.13 h2098e52_0
graphviz 2.40.1 hefbbd9a_2
greenlet 0.4.15 py35h1de35cc_0
grpcio 1.12.1 py35hd9629dc_0
h5py 2.10.0
h5py 2.8.0 py35h60fea5d_3
harfbuzz 1.8.8 hb8d4a28_0
hdf5 1.8.20 hfa1e0ec_1
heapdict 1.0.1 py_0
html5lib 1.0.1 py_0
html5lib 0.9999999
hyperlink 19.0.0 py_0
icu 58.2 h0a44026_3
idna 2.7 py35_0
idna-ssl 1.1.0
imageio 2.8.0 py_0
imagesize 1.2.0 py_0
importlib_metadata 0.5 py_0 conda-forge
imutils 0.5.2
incremental 17.5.0 py35_0
intel-openmp 2019.4 233
ipykernel 4.10.0 py35_0
ipython 6.5.0 py35_0
ipython_genutils 0.2.0 py35hf129286_0
ipywidgets 5.1.5 py35_0 menpo
isort 4.3.4 py35_0
itsdangerous 1.1.0 py_0
jasper 2.0.14 h636a363_1
jbig 2.1 h4d881f8_0
jdcal 1.4.1 py_0
jedi 0.12.1 py35_0
jinja2 2.11.2 py_0
joblib 0.14.1
jpeg 9d h0b31af3_0 conda-forge
jsonschema 2.6.0 py35h2dd9e4b_0
jupyter 1.0.0 py35_7
jupyter_client 5.3.3 py_0
jupyter_console 5.2.0 py35hd2aa692_1
jupyter_core 4.5.0 py_0
Keras-Preprocessing 1.1.2
keyring 13.2.1 py35_0
kiwisolver 1.0.1 py35h219a9d8_0
krb5 1.16.1 h24a3359_6
lazy-object-proxy 1.3.1 py35h1de35cc_2
leptonica 1.78.0 h75b9b3b_2 conda-forge
libarchive 3.3.3 h786848e_5
libcurl 7.61.1 hf30b1f0_0
libcxx 10.0.0 1
libcxxabi 4.0.1 hcfea43d_1
libdynd 0.7.2 0
libedit 3.1.20181209 hb402a30_0
libffi 3.2.1 h0a44026_6
libgfortran 3.0.1 h93005f0_2
libiconv 1.16 h1de35cc_0
libntlm 1.5 h1de35cc_0
libopenblas 0.2.20 hdc02c5d_7
libopencv 3.4.2 h0d3447a_1
libopus 1.3.1 h1de35cc_0
libpng 1.6.37 ha441bb4_0
libprotobuf 3.6.0 hd9629dc_0
libsodium 1.0.16 h3efe00b_0
libssh2 1.8.0 h322a93b_4
libtiff 4.1.0 hcb84e12_0
libutf8proc 2.1.1 h1de35cc_0
libvpx 1.7.0 h378b8a2_0
libwebp 1.0.2 hd3bf737_5 conda-forge
libxml2 2.9.9 hf6e021a_1
libxslt 1.1.33 h33a18ac_0
llvm-openmp 4.0.1 hcfea43d_1
llvmlite 0.24.0 py35hc454e04_0
loader 2017.9.11
locket 0.2.0 py35h58cf053_1
Logbook 1.5.3
logcc 2018.3.1
lxml 4.2.5 py35hef8c89e_0
lz4-c 1.8.1.2 h1de35cc_0
lzo 2.10 h1de35cc_2
markdown 2.6.11 py35_0
Markdown 2.6.8
markupsafe 1.0 py35h1de35cc_1
matplotlib 3.0.0 py35h54f8f79_0
matplotlib 3.0.3
mccabe 0.6.1 py35h3f6a9a1_0
mistune 0.8.3 py35h1de35cc_1
mkl 2018.0.3 1
mkl-service 1.1.2 py35h6b9c3cc_4
mkl_fft 1.0.9 py35_0 conda-forge
mkl_random 1.0.1 py35_0 conda-forge
more-itertools 8.3.0 py_0
mpc 1.0.3 h7a72875_5
mpfr 3.1.5 h711e7fd_2
mpmath 1.0.0 py35_2
msgpack-python 0.5.6 py35h04f5b5a_1 anaconda
multidict 4.7.6
multipledispatch 0.6.0 py35_0
multiprocess 0.70.10
navigator-updater 0.2.1 py35_0
nb_anacondacloud 1.4.0 py35_0
nb_conda 2.2.1 py35hd4e941f_0
nb_conda_kernels 2.1.0 py35_0
nbconvert 5.5.0 py_0
nbformat 5.0.6 py_0
nbpresent 3.0.2 py35hb9ebbd1_1
ncurses 6.2 h0a44026_1
networkx 2.4 py_0
ninja 1.8.2 py35h04f5b5a_1
nltk 3.3.0 py35_0
nomkl 3.0 0
nose 1.3.7 py35_2
notebook 5.6.0 py35_0
numba 0.39.0 py35h6440ff4_0
numexpr 2.6.5 py35_nomklhd0a1019_0
numpy 1.15.2 py35_blas_openblashd3ea46f_0 [blas_openblas] conda-forge
numpy 1.13.3
numpy 1.18.5
numpy-base 1.14.3 py35h9797aa9_0
numpydoc 0.9.2 py_0
oauthlib 3.1.0
odo 0.5.0 py35_1
olefile 0.46 py_0
openblas 0.2.20 8 conda-forge
openblas-devel 0.2.20 7
opencv 3.4.2 py35h40b0b35_1
opencv-python 4.2.0.34
opencv3 3.1.0 py35_0 menpo
openjpeg 2.3.1 h254dc36_3 conda-forge
openpyxl 2.6.3 py_0
openslide 3.4.1 2 bioconda
openslide-python 1.1.1 py35h470a237_0 bioconda
openssl 1.0.2u h1de35cc_0
opt-einsum 3.2.1
packaging 20.3 py_0
pandas 0.23.4 py35h6440ff4_0
pandoc 2.2.3.2 0
pandocfilters 1.4.2 py35_1
pango 1.42.4 h7e27002_1
parso 0.7.0 py_0
partd 1.1.0 py_0
path.py 12.0.2 py_0
pathlib 1.0.1
pathlib2 2.3.2 py35_0
pathos 0.2.6
patsy 0.5.0 py35_0
pcre 8.43 h0a44026_0
pendulum 2.1.0
pep8 1.7.1 py35_0
pexpect 4.6.0 py35_0
pickleshare 0.7.4 py35h9517181_0
pillow 5.2.0 py35hb68e598_0
Pillow 7.1.2
pip 20.1.1
pip 10.0.1 py35_0
pixman 0.38.0 h1de35cc_0
pkginfo 1.4.2 py35_1
pluggy 0.11.0 py_0
ply 3.11 py35_0
pony 0.7.13
pox 0.2.8
ppft 1.6.6.2
prettytable 0.7.2
progressbar2 3.51.4
prometheus_client 0.7.1 py_0
prompt_toolkit 1.0.15 py35h93950c5_0
protobuf 3.3.0
protobuf 3.6.0 py35h0a44026_0
protobuf 3.12.2
psutil 5.4.7 py35h1de35cc_0
ptyprocess 0.6.0 py35_0
py 1.8.1 py_0
py-opencv 3.4.2 py35h0d3447a_1
pyamg 3.3.0
pyasn1 0.4.8 py_0
pyasn1-modules 0.2.7 py_0
pycocotools 2.0.0 py35h470a237_0 hcc
pycodestyle 2.6.0 py_0
pycosat 0.6.3 py35h745f8c1_0
pycparser 2.20 py_0
pycrypto 2.6.1 py35h1de35cc_8
pycurl 7.43.0.2 py35hdbc3d79_0
pydotplus 2.0.2 py_1
pyflakes 2.2.0 py_0
pygame 1.9.2
pygments 2.6.1 py_0
pylint 2.1.1 py35_0
pyodbc 4.0.24 py35h0a44026_0
pyopenssl 18.0.0 py35_0
pyparsing 2.4.7 py_0
pyqt 5.9.2 py35h655552a_2
pysocks 1.6.8 py35_0
pytables 3.4.4 py35hca30cd5_0
pytesseract 0.3.4
pytest 3.8.1 py35_0
python 3.5.6 hc167b69_0
python-dateutil 2.8.1 py_0
python-graphviz 0.14 py_0
python-libarchive-c 2.9 py_0
python-resize-image 1.1.18
python-spams 2.6.1 py35_blas_openblash6af021c_201 [blas_openblas] conda-forge
python-utils 2.4.0
python.app 2 py35_9
pytorch 1.4.0 py3.5_0 pytorch
pytz 2020.1 py_0
pytzdata 2019.3
pywavelets 0.5.2 np112py35_0
pyyaml 3.13 py35h1de35cc_0
pyzmq 17.1.2 py35h1de35cc_0
qt 5.9.7 h468cd18_1
qtawesome 0.7.0 py_0
qtconsole 4.7.4 py_0
qtpy 1.9.0 py_0
readline 7.0 h1de35cc_5
redis 5.0.3 h1de35cc_0
redis-py 3.5.0 py_0
requests 2.19.1 py35_0
requests 2.21.0
requests-oauthlib 1.3.0
rope 0.17.0 py_0
rsa 4.0
ruamel_yaml 0.15.46 py35h1de35cc_0
scikit-image 0.15.0
scikit-image 0.14.0 py35hfc679d8_1 conda-forge
scikit-learn 0.22.2.post1
scikit-video 1.1.11
scipy 1.4.1
scipy 1.1.0 py35_blas_openblash7943236_201 [blas_openblas] conda-forge
seaborn 0.7.1 py35_0
send2trash 1.5.0 py35_0
serf 1.3.9 h1f07962_0
service_identity 18.1.0 pyh91ea838_0
setuptools 36.2.4
setuptools 47.1.1
setuptools 40.2.0 py35_0
Shapely 1.7.0
simplegeneric 0.8.1 py35_2
singledispatch 3.4.0.3 py35h0acf360_0
sip 4.19.8 py35h0a44026_0
six 1.10.0
six 1.15.0
six 1.11.0 py35_1
sk-video 1.1.10
snappy 1.1.7 he62c110_3
snowballstemmer 2.0.0 py_0
sockjs-tornado 1.0.5 py35_0
sortedcollections 1.1.1 py_0
sortedcontainers 2.0.5 py35_0
sphinx 3.0.3 py_0
sphinxcontrib 1.0 py35_1
sphinxcontrib-applehelp 1.0.2 py_0
sphinxcontrib-devhelp 1.0.2 py_0
sphinxcontrib-htmlhelp 1.0.3 py_0
sphinxcontrib-jsmath 1.0.1 py_0
sphinxcontrib-qthelp 1.0.3 py_0
sphinxcontrib-serializinghtml 1.1.4 py_0
sphinxcontrib-websupport 1.2.1 py_0
spyder 3.3.1 py35_1
spyder-kernels 0.2.6 py35_0
sqlalchemy 1.2.11 py35h1de35cc_0
sqlite 3.31.1 h5c1f38d_1
staintools 2.1.2
statsmodels 0.8.0 np112py35_0
svn 1.10.2 h670755d_0
sympy 1.2 py35_0
tbb 4.3_20141023 0 menpo
tblib 1.6.0 py_0
tensorboard 1.10.0 py35hdc36e2c_0
tensorboard 2.2.2
tensorboard-plugin-wit 1.6.0.post3
tensorflow 1.10.0 eigen_py35h5ac2770_0
tensorflow 2.2.0
tensorflow-base 1.10.0 eigen_py35h4f0eeca_0
tensorflow-estimator 2.2.0
tensorlayer 2.2.3
termcc 2019.8.2
termcolor 1.1.0 py35_1
terminado 0.8.1 py35_1
terminaltables 3.1.0
tesseract 4.1.1 haaf70cb_2 conda-forge
testpath 0.4.4 py_0
tk 8.6.8 ha441bb4_0
toolz 0.10.0 py_0
torch 1.5.1
torch 1.0.0
torchfile 0.1.0
torchsummary 1.5.1
torchvision 0.6.1
torchvision 0.5.0 py35_cpu pytorch
tornado 5.1.1 py35h1de35cc_0
tqdm 4.46.0 py_0
traitlets 4.3.2 py35hd3d1486_0
twisted 17.5.0 py35_0
typed-ast 1.1.0 py35h6952a12_0
typing-extensions 3.7.4.2
umap 0.1.1
umap-learn 0.3.10
unicodecsv 0.14.1 py35h2154ad0_0
unixodbc 2.3.7 h1de35cc_0
urllib3 1.23 py35_0
urllib3 1.24.1
utils 0.9.0
visdom 0.1.8.8
wcwidth 0.1.9 py_0
webencodings 0.5.1 py35_1
websocket-client 0.55.0
websockets 7.0
Werkzeug 0.12.2
werkzeug 1.0.1 py_0
wget 3.2
wheel 0.31.1 py35_0
wheel 0.29.0
widgetsnbextension 1.2.3 py35_1 menpo
wordcloud 1.5.0
wrap 2018.3.1
wrapt 1.10.11 py35h1de35cc_2
wrapt 1.12.1
xlrd 1.2.0 py_0
xlsxwriter 1.2.8 py_0
xlwings 0.11.8 py35_0
xlwt 1.2.0 py35hf70d7fa_0
xz 5.2.5 h1de35cc_0
yaml 0.1.7 hc338f04_2
yarl 1.4.2
zeromq 4.2.5 h0a44026_1
zict 2.0.0 py_0
zlib 1.2.11 h1de35cc_3
zope 1.0 py35_1
zope.interface 4.5.0 py35h1de35cc_0
zstd 1.3.7 h5bba6e5_0

```

Details about conda and system ( conda info ):

```
$ conda info

active environment : None
user config file : /Users/amirali/.condarc
populated config files : /Users/amirali/.condarc
conda version : 4.5.11
conda-build version : 3.15.1
python version : 3.5.6.final.0
base environment : /Users/amirali/anaconda (writable)
channel URLs : https://conda.anaconda.org/menpo/osx-64
https://conda.anaconda.org/menpo/noarch
https://repo.anaconda.com/pkgs/main/osx-64
https://repo.anaconda.com/pkgs/main/noarch
https://repo.anaconda.com/pkgs/free/osx-64
https://repo.anaconda.com/pkgs/free/noarch
https://repo.anaconda.com/pkgs/r/osx-64
https://repo.anaconda.com/pkgs/r/noarch
https://repo.anaconda.com/pkgs/pro/osx-64
https://repo.anaconda.com/pkgs/pro/noarch
https://conda.anaconda.org/conda-forge/osx-64
https://conda.anaconda.org/conda-forge/noarch
package cache : /Users/amirali/anaconda/pkgs
/Users/amirali/.conda/pkgs
envs directories : /Users/amirali/anaconda/envs
/Users/amirali/.conda/envs
platform : osx-64
user-agent : conda/4.5.11 requests/2.19.1 CPython/3.5.6 Darwin/19.3.0 OSX/10.15.3
UID:GID : 501:20
netrc file : None
offline mode : False
```