[bitbake-devel] [PATCH] prserv/serv: Ensure sync happens in the correct thread

[Richard Purdie]

The sync/commit calls are happening in the submission thread which can
race against the handler. The handler may start new transactions which
then causes the submission thread to error with "cannot start a
transaction within a transaction".

The fix is to move the calls to the correct thread.

Signed-off-by: Richard Purdie <richard.purdie at linuxfoundation.org>

diff --git a/bitbake/lib/prserv/serv.py b/bitbake/lib/prserv/serv.py
index 6ab1097..25eb46a 100644
--- a/bitbake/lib/prserv/serv.py
+++ b/bitbake/lib/prserv/serv.py
@@ -76,11 +76,19 @@ class PRServer(SimpleXMLRPCServer):
         In addition, exception handling is done here.
 
         """
+        iter_count = 1
+        # With 60 iterations between syncs and a 0.5 second timeout between
+        # iterations, this will sync if dirty every ~30 seconds.
+        iterations_between_sync = 60
+
         while True:
             (request, client_address) = self.requestqueue.get()
             try:
                 self.finish_request(request, client_address)
                 self.shutdown_request(request)
+                iter_count = (iter_count + 1) % iterations_between_sync
+                if iter_count == 0:
+                    self.table.sync_if_dirty()
             except:
                 self.handle_error(request, client_address)
                 self.shutdown_request(request)
@@ -122,10 +130,6 @@ class PRServer(SimpleXMLRPCServer):
     def work_forever(self,):
         self.quit = False
         self.timeout = 0.5
-        iter_count = 1
-        # With 60 iterations between syncs and a 0.5 second timeout between
-        # iterations, this will sync if dirty every ~30 seconds.
-        iterations_between_sync = 60
 
         logger.info("Started PRServer with DBfile: %s, IP: %s, PORT: %s, PID: %s" %
                      (self.dbfile, self.host, self.port, str(os.getpid())))
@@ -133,9 +137,6 @@ class PRServer(SimpleXMLRPCServer):
         self.handlerthread.start()
         while not self.quit:
             self.handle_request()
-            iter_count = (iter_count + 1) % iterations_between_sync
-            if iter_count == 0:
-                self.table.sync_if_dirty()
 
         self.table.sync()
         logger.info("PRServer: stopping...")