[MRG] OpenMP support (#260)

* Added : OpenMP support
Restored : Epsilon and Debug mode
Replaced : parmap => multiprocessing is now replace by multithreading

* Commit clean up

* Number of CPUs correctly calculated on SLURM clusters

* Corrected number of processes for cluster slurm

* Mistake corrected

* parmap is now deprecated

* Now a different solver is used depending on the requested number of threads

* Tiny mistake corrected

* Folders are now in the ot library instead of at the root

* Helpers is now correctly placed

* Attempt to make compilation work smoothly

* OS compatible path

* NumThreads now defaults to 1

* Better flags

* Mistake corrected in case of OpenMP unavailability

* Revert OpenMP flags modification, which do not compile on Windows

* Test helper functions

* Helpers comments

* Documentation update

* File title corrected

* Warning no longer using print

* Last attempt for macos compilation

* pls work

* atempt

* solving a type error

* TypeError OpenMP

* Compilation finally working on Windows

* Bug solve, number of threads now correctly selected

* 64 bits solver to avoid overflows for bigger problems

* 64 bits EMD corrected

Co-authored-by: kguerda-idris <ssos023@jean-zay3.idris.fr>
Co-authored-by: ncassereau-idris <84033440+ncassereau-idris@users.noreply.github.com>
Co-authored-by: ncassereau <nathan.cassereau@idris.fr>
Co-authored-by: Rémi Flamary <remi.flamary@gmail.com>

1 files changed, 5 insertions, 33 deletions

diff --git a/ot/utils.py b/ot/utils.py
index 4dac0c5..6a782e6 100644
--- a/ot/utils.py
+++ b/ot/utils.py
@@ -7,7 +7,6 @@ Various useful functions
 #
 # License: MIT License
 
-import multiprocessing
 from functools import reduce
 import time
 
@@ -311,38 +310,11 @@ def label_normalization(y, start=0):
     return y
 
 
-def fun(f, q_in, q_out):
-    """ Utility function for parmap with no serializing problems """
-    while True:
-        i, x = q_in.get()
-        if i is None:
-            break
-        q_out.put((i, f(x)))
-
-
-def parmap(f, X, nprocs=multiprocessing.cpu_count()):
-    """ paralell map for multiprocessing (only map on windows)"""
-
-    if not sys.platform.endswith('win32') and not sys.platform.endswith('darwin'):
-
-        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(X)]
-        [q_in.put((None, None)) for _ in range(nprocs)]
-        res = [q_out.get() for _ in range(len(sent))]
-
-        [p.join() for p in proc]
-
-        return [x for i, x in sorted(res)]
-    else:
-        return list(map(f, X))
+def parmap(f, X, nprocs="default"):
+    """ paralell map for multiprocessing.
+    The function has been deprecated and only performs a regular map.
+    """
+    return list(map(f, X))
 
 
 def check_params(**kwargs):