Protection for cases where ncores=1

Author: FrancescAlted

blosc2/__init__.py

@@ -242,7 +242,9 @@ class Tuner(Enum):
 The blosc2 version + date.
 """
 # Internal Blosc threading
-nthreads = ncores = detect_number_of_cores() // 2
+nthreads = ncores = detect_number_of_cores()
+if ncores > 1:
+    nthreads = ncores // 2
 """Number of threads to be used in compression/decompression.
 """
 # Protection against too many threads