review comments

Author: abouteiller

ompi/mpi/c/init_thread.c.in

@@ -40,7 +40,8 @@
 PROTOTYPE ERROR_CLASS init_thread(INT_OUT argc, ARGV argv, INT required,
                                   INT_OUT provided)
 {
-    int err, err_arg_required = false, safe_required = MPI_THREAD_SERIALIZED;
+    int err, safe_required = MPI_THREAD_SERIALIZED;
+    bool err_arg_required = false;
     char *env;
 
     ompi_hook_base_mpi_init_thread_top(argc, argv, required, provided);
@@ -54,16 +55,16 @@ PROTOTYPE ERROR_CLASS init_thread(INT_OUT argc, ARGV argv, INT required,
         safe_required = required;
     }
 
-    /* check for environment overrides for required thread level.  If
+    /* check for environment overrides for required thread level. If
      * there is, check to see that it is a valid/supported thread level.
-     *  if it is lower than argument required, set it anyway, program can
-     * check provided == required to verify that required has been ignored
+     * If valid, the environment variable always override the provided thread
+     * level (even if lower than argument `required`). A user program can
+     * check `provided != required` to check if `required` has been overruled.
      */
     if (NULL != (env = getenv("OMPI_MPI_THREAD_LEVEL"))) {
         int env_required = atoi(env);
-        err_arg_required = err_arg_required ||
-                           (env_required != MPI_THREAD_SINGLE && env_required != MPI_THREAD_FUNNELED &&
-                            env_required != MPI_THREAD_SERIALIZED && env_required != MPI_THREAD_MULTIPLE);
+        err_arg_required |= (env_required != MPI_THREAD_SINGLE && env_required != MPI_THREAD_FUNNELED &&
+                             env_required != MPI_THREAD_SERIALIZED && env_required != MPI_THREAD_MULTIPLE);
         if (!err_arg_required) {
             safe_required = env_required;
         }