allow adjusting # of cpu cores to use with EMCC_CORES

2 files changed, 2 insertions, 2 deletions

diff --git a/emscripten.py b/emscripten.py
index e64e11e7..fd9c8ba2 100755
--- a/emscripten.py
+++ b/emscripten.py
@@ -160,7 +160,7 @@ def emscript(infile, settings, outfile, libraries=[]):
 
   # Phase 2 - func
 
-  cores = multiprocessing.cpu_count()
+  cores = int(os.environ.get('EMCC_CORES') or multiprocessing.cpu_count())
   assert cores >= 1
   if cores > 1:
     intended_num_chunks = int(round(cores * NUM_CHUNKS_PER_CORE))
diff --git a/tools/js_optimizer.py b/tools/js_optimizer.py
index 753e9db8..69a5bb2b 100644
--- a/tools/js_optimizer.py
+++ b/tools/js_optimizer.py
@@ -100,7 +100,7 @@ def run_on_js(filename, passes, js_engine, jcache):
   total_size = len(js)
   js = None
 
-  cores = multiprocessing.cpu_count()
+  cores = int(os.environ.get('EMCC_CORES') or multiprocessing.cpu_count())
   intended_num_chunks = int(round(cores * NUM_CHUNKS_PER_CORE))
   chunk_size = min(MAX_CHUNK_SIZE, max(MIN_CHUNK_SIZE, total_size / intended_num_chunks))