_artifactcache/pushreceive.py: Add handshake after sending objects

Ensure all objects have been sent before moving them into the repository
and do not terminate pusher while receiver is still processing.

1 files changed, 12 insertions, 0 deletions

diff --git a/buildstream/_artifactcache/pushreceive.py b/buildstream/_artifactcache/pushreceive.py
index fd5b1d96d..3603e083d 100644
--- a/buildstream/_artifactcache/pushreceive.py
+++ b/buildstream/_artifactcache/pushreceive.py
@@ -496,6 +496,12 @@ class OSTreePusher(object):
         # Send all the objects to receiver, checking status after each
         self.writer.send_putobjects(self.repo, objects)
 
+        # Inform receiver that all objects have been sent
+        self.writer.send_done()
+
+        # Wait until receiver has completed
+        self.reader.receive_done()
+
         return self.close()
 
 
@@ -562,6 +568,9 @@ class OSTreeReceiver(object):
         # Receive the actual objects
         received_objects = self.reader.receive_putobjects(self.repo)
 
+        # Ensure that pusher has sent all objects
+        self.reader.receive_done()
+
         # If we didn't get any objects, we're done
         if len(received_objects) == 0:
             return 0
@@ -579,6 +588,9 @@ class OSTreeReceiver(object):
             logging.debug('Setting ref {} to {}'.format(branch, revs[1]))
             self.repo.set_ref_immediate(None, branch, revs[1], None)
 
+        # Inform pusher that everything is in place
+        self.writer.send_done()
+
         return 0