From e3d006eb7fd76d6e540cdcaf485eb0724b684c21 Mon Sep 17 00:00:00 2001
From: Junmin Gu <junmin@login3.summit.olcf.ornl.gov>
Date: Tue, 13 Jun 2023 14:54:26 -0400
Subject: [PATCH] added async flag

---
 src/IO/ADIOS/ADIOS2IOHandler.cpp | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/src/IO/ADIOS/ADIOS2IOHandler.cpp b/src/IO/ADIOS/ADIOS2IOHandler.cpp
index 266063b722..0ecb02f3e0 100644
--- a/src/IO/ADIOS/ADIOS2IOHandler.cpp
+++ b/src/IO/ADIOS/ADIOS2IOHandler.cpp
@@ -2995,6 +2995,19 @@ namespace detail
                 m_IO.SetParameter("Profile", "Off");
             }
         }
+        if (notYetConfigured("AsyncWrite"))
+        {
+            if (1 == auxiliary::getEnvNum("OPENPMD_ADIOS2_ASYNC_WRITE", 1) &&
+                notYetConfigured("AsyncWrite"))
+            {
+                m_IO.SetParameter("AsyncWrite", "On");
+            }
+            else
+            {
+                m_IO.SetParameter("AsyncWrite", "Off");
+            }
+        }
+
 #if openPMD_HAVE_MPI
         {
             auto num_substreams =