write node.url and portnum files atomically, to fix race in test_runner

[tahoe-lafs/tahoe-lafs.git] / src / allmydata / node.py

diff --git a/src/allmydata/node.py b/src/allmydata/node.py
index 458c57e1c237d6ee0149f6445f4c45985e40dd0d..aedaf8429f3b38b72cab206331cd42e160f94627 100644 (file)
--- a/src/allmydata/node.py
+++ b/src/allmydata/node.py
@@ -360,7 +360,7 @@ class Node(service.MultiService):
         portnum = l.getPortnum()
         # record which port we're listening on, so we can grab the same one
         # next time
-        open(self._portnumfile, "w").write("%d\n" % portnum)
+        fileutil.write_atomically(self._portnumfile, "%d\n" % portnum, mode="")
 
         base_location = ",".join([ "%s:%d" % (addr, portnum)
                                    for addr in local_addresses ])