diff --git a/disk/src/lib.rs b/disk/src/lib.rs
index 7ac0f73..1e9955c 100644
--- a/disk/src/lib.rs
+++ b/disk/src/lib.rs
@@ -10,6 +10,7 @@ use futures_core::Stream;
 use futures_util::future::FusedFuture;
 use bytes::Bytes;
 use std::path::PathBuf;
+use std::sync::Mutex;
 
 pub async fn read_test_1(query: &netpod::AggQuerySingleChannel) -> Result<netpod::BodyStream, Error> {
     let pre = "/data/sf-databuffer/daq_swissfel";
@@ -146,8 +147,10 @@ impl FusedFuture for Fopen1 {
     }
 }
 
+unsafe impl Send for Fopen1 {}
 
-pub fn raw_concat_channel_read_stream(query: &netpod::AggQuerySingleChannel) -> impl Stream<Item=Result<Bytes, Error>> {
+
+pub fn raw_concat_channel_read_stream(query: &netpod::AggQuerySingleChannel) -> impl Stream<Item=Result<Bytes, Error>> + Send {
     use futures_util::{StreamExt, FutureExt, pin_mut, select};
     let mut query = query.clone();
     async_stream::stream! {
@@ -169,11 +172,11 @@ pub fn raw_concat_channel_read_stream(query: &netpod::AggQuerySingleChannel) ->
 }
 
 
-pub fn raw_concat_channel_read_stream_try_open_in_background(query: &netpod::AggQuerySingleChannel) -> impl Stream<Item=Result<Bytes, Error>> {
+pub fn raw_concat_channel_read_stream_try_open_in_background(query: &netpod::AggQuerySingleChannel) -> impl Stream<Item=Result<Bytes, Error>> + Send {
     use futures_util::{StreamExt, FutureExt, pin_mut, select};
     use tokio::io::AsyncReadExt;
     let mut query = query.clone();
-    let mut fopen = None;
+    let mut fopen = Mutex::new(None);
     let mut file: Option<File> = None;
     let mut file_taken_for_read = false;
     async_stream::stream! {
@@ -181,14 +184,14 @@ pub fn raw_concat_channel_read_stream_try_open_in_background(query: &netpod::Agg
         let mut i1 = 0;
         loop {
             {
-                if fopen.is_none() && file.is_none() && !file_taken_for_read {
+                if fopen.lock().unwrap().is_none() && file.is_none() && !file_taken_for_read {
                     query.timebin = 18700 + i1;
-                    fopen = Some(Fopen1::new(datapath(&query)));
+                    fopen.lock().unwrap().replace(Fopen1::new(datapath(&query)));
                     i1 += 1;
                 }
             }
             let blen = query.buffer_size as usize;
-            if fopen.is_some() {
+            if fopen.lock().unwrap().is_some() {
                 if file.is_some() {
                     if reading.is_none() {
                         let mut buf = bytes::BytesMut::with_capacity(blen);
@@ -201,14 +204,15 @@ pub fn raw_concat_channel_read_stream_try_open_in_background(query: &netpod::Agg
                         let a = Box::pin(a);
                         reading = Some(a.fuse());
                     }
+                    let mut fopen3 = fopen.lock().unwrap();
                     let bufres = select! {
                         // TODO can I avoid the unwraps via matching already above?
-                        f = fopen.as_mut().unwrap() => {
-                            fopen = None;
+                        /*f = fopen3.as_mut().unwrap() => {
+                            fopen3.take();
                             file = Some(f.unwrap());
                             info!("opened next file while also waiting on data read");
                             None
-                        }
+                        }*/
                         k = reading.as_mut().unwrap() => {
                             //() == k;
                             reading = None;
@@ -226,14 +230,14 @@ pub fn raw_concat_channel_read_stream_try_open_in_background(query: &netpod::Agg
                 }
                 else {
                     // TODO try to avoid this duplicated code:
-                    select! {
+                    /*select! {
                         // TODO can I avoid the unwraps via matching already above?
-                        f = fopen.as_mut().unwrap() => {
+                        f = fopen.lock().unwrap().as_mut().unwrap() => {
                             fopen = None;
                             file = Some(f.unwrap());
                             info!("opened next file");
                         }
-                    };
+                    };*/
                 }
             }
             else if file.is_some() {
diff --git a/httpret/src/lib.rs b/httpret/src/lib.rs
index 08ab382..6d7f77f 100644
--- a/httpret/src/lib.rs
+++ b/httpret/src/lib.rs
@@ -65,7 +65,7 @@ async fn parsed_raw(req: Request<Body>) -> Result<Response<Body>, Error> {
     let query: AggQuerySingleChannel = serde_json::from_slice(&bodyslice)?;
     //let q = disk::read_test_1(&query).await?;
     //let s = q.inner;
-    let s = disk::raw_concat_channel_read_stream(&query);
+    let s = disk::raw_concat_channel_read_stream_try_open_in_background(&query);
     let res = response(StatusCode::OK)
         .body(Body::wrap_stream(s))?;
     /*