From d830146bf86c667832fc5ecf2bcfcfedd0aee380 Mon Sep 17 00:00:00 2001
From: Erik Johnston <erik@matrix.org>
Date: Wed, 19 Feb 2020 13:34:21 +0000
Subject: [PATCH] Freeze allocated objects on startup.

This may make gc go a bit faster as the gc will know things like
caches/data stores etc. are frozen without having to check.
---
 synapse/app/_base.py | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/synapse/app/_base.py b/synapse/app/_base.py
index 0e8b467a3e..46cf2fb098 100644
--- a/synapse/app/_base.py
+++ b/synapse/app/_base.py
@@ -279,6 +279,12 @@ def start(hs, listeners=None):
 
         setup_sentry(hs)
         setup_sdnotify(hs)
+
+        # We now freeze all allocated objects in the hopes that (almost)
+        # everything currently allocated are things that will be used for the
+        # rest of time. Doing so means less work each GC (hopefully)
+        gc.collect()
+        gc.freeze()
     except Exception:
         traceback.print_exc(file=sys.stderr)
         reactor = hs.get_reactor()