Fixes ResourceWarnings on macOS (#38)

theano/misc/cpucount.py

@@ -26,32 +26,14 @@
 # OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 #
 
-# This function was modified from the original code
-# We can't use the multiprocessing module as it was included in python2.6
-# and we support python 2.4
-
-import os
-import sys
+import multiprocessing
 
 
 def cpuCount():
     """
     Returns the number of CPUs in the system
     """
-    if sys.platform == "win32":
-        try:
-            num = int(os.environ["NUMBER_OF_PROCESSORS"])
-        except (ValueError, KeyError):
-            num = -1
-    elif sys.platform == "darwin":
-        try:
-            num = int(os.popen("sysctl -n hw.ncpu").read())
-        except ValueError:
-            num = -1
-    else:
-        try:
-            num = os.sysconf("SC_NPROCESSORS_ONLN")
-        except (ValueError, OSError, AttributeError):
-            num = -1
-
-    return num
+    try:
+        return multiprocessing.cpu_count()
+    except NotImplementedError:
+        return -1