server/process: Disable gc around critical sectionyocto-3.1.17yocto-3.1.162020-04.17-dunfell2020-04.16-dunfell1.46.171.46.16

The python gc can trigger whilst we're holding the event stream lock
and when cleaning up objects, they can trigger warnings. This translates
into a new event which would then need the lock and we can deadlock.

Disable gc whilst we hold that lock to avoid this unfortunate and
problematic situation.

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
(cherry picked from commit 96a6303949cefd469bcf5ed250ff512271354357)
Signed-off-by: Steve Sakoman <steve@sakoman.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

1 files changed, 3 insertions, 0 deletions

diff --git a/lib/bb/server/process.py b/lib/bb/server/process.py
index 3c9ed7068..4bdb84ae3 100644
--- a/lib/bb/server/process.py
+++ b/lib/bb/server/process.py
@@ -25,6 +25,7 @@ import subprocess
 import errno
 import re
 import datetime
+import gc
 import bb.server.xmlrpcserver
 from bb import daemonize
 from multiprocessing import queues
@@ -671,8 +672,10 @@ class ConnectionWriter(object):
 
     def send(self, obj):
         obj = multiprocessing.reduction.ForkingPickler.dumps(obj)
+        gc.disable()
         with self.wlock:
             self.writer.send_bytes(obj)
+        gc.enable()
 
     def fileno(self):
         return self.writer.fileno()