#9 fix race condition by grabbing lock before adding cache entry

cellxgene_gateway/gateway.py

@@ -11,7 +11,7 @@
 import datetime
 import os
 import logging
-from threading import Thread
+from threading import Thread, Lock
 import json
 
 from flask import (
@@ -168,11 +168,12 @@ def filecrawl():
         rendered_html=rendered_html,
     )
 
-
+entry_lock = Lock()
 @app.route("/view/<path:path>", methods=["GET", "PUT", "POST"])
 def do_view(path):
     dataset = get_dataset(path)
     file_path = get_file_path(dataset)
+    with entry_lock:
         match = cache.check_entry(dataset)
         if match is None:
             uascripts = get_extra_scripts()