1 files changed, 6 insertions, 3 deletions
diff --git a/src/thread_utils.h b/src/thread_utils.h
index fe096a36..2cb87a8d 100644
--- a/src/thread_utils.h
+++ b/src/thread_utils.h
@@ -21,10 +21,14 @@ namespace MOShared {
  *
  */
 template <class It, class Callable>
-void parallelMap(It begin, It end, Callable callable, std::size_t nThreads) {
+void parallelMap(It begin, It end, Callable callable, std::size_t nThreads) 
+{
+  std::mutex m;
   std::vector<std::thread> threads(nThreads);
 
-  std::mutex m;
+  // Create the thread:
+  //  - The mutex is only used to fetch/increment the iterator.
+  //  - The callable is copied in each thread to avoid conflicts.
   for (auto &thread: threads) {
     thread = std::thread([&m, &begin, end, callable]() {
       while (true) {
@@ -43,7 +47,6 @@ void parallelMap(It begin, It end, Callable callable, std::size_t nThreads) {
     });
   }
 
-
   // Join everything:
   for (auto& t : threads) {
     t.join();