From d250521cf5171a2c815b380f184f39cd8b1963e5 Mon Sep 17 00:00:00 2001
From: Patrick Cloke <clokep@users.noreply.github.com>
Date: Wed, 2 Sep 2020 07:44:50 -0400
Subject: [PATCH] Convert the main methods run by the reactor to async. (#8213)

---
 changelog.d/8213.misc     |  1 +
 synapse/app/admin_cmd.py  | 20 +++++++++-----------
 synapse/app/homeserver.py | 18 ++++++++----------
 3 files changed, 18 insertions(+), 21 deletions(-)
 create mode 100644 changelog.d/8213.misc

diff --git a/changelog.d/8213.misc b/changelog.d/8213.misc
new file mode 100644
index 000000000000..dfe4c03171d6
--- /dev/null
+++ b/changelog.d/8213.misc
@@ -0,0 +1 @@
+Convert various parts of the codebase to async/await.
diff --git a/synapse/app/admin_cmd.py b/synapse/app/admin_cmd.py
index a37818fe9ab2..b6c90856706c 100644
--- a/synapse/app/admin_cmd.py
+++ b/synapse/app/admin_cmd.py
@@ -79,8 +79,7 @@ def start_listening(self, listeners):
         pass
 
 
-@defer.inlineCallbacks
-def export_data_command(hs, args):
+async def export_data_command(hs, args):
     """Export data for a user.
 
     Args:
@@ -91,10 +90,8 @@ def export_data_command(hs, args):
     user_id = args.user_id
     directory = args.output_directory
 
-    res = yield defer.ensureDeferred(
-        hs.get_handlers().admin_handler.export_user_data(
-            user_id, FileExfiltrationWriter(user_id, directory=directory)
-        )
+    res = await hs.get_handlers().admin_handler.export_user_data(
+        user_id, FileExfiltrationWriter(user_id, directory=directory)
     )
     print(res)
 
@@ -232,14 +229,15 @@ def start(config_options):
     # We also make sure that `_base.start` gets run before we actually run the
     # command.
 
-    @defer.inlineCallbacks
-    def run(_reactor):
+    async def run():
         with LoggingContext("command"):
-            yield _base.start(ss, [])
-            yield args.func(ss, args)
+            _base.start(ss, [])
+            await args.func(ss, args)
 
     _base.start_worker_reactor(
-        "synapse-admin-cmd", config, run_command=lambda: task.react(run)
+        "synapse-admin-cmd",
+        config,
+        run_command=lambda: task.react(lambda _reactor: defer.ensureDeferred(run())),
     )
 
 
diff --git a/synapse/app/homeserver.py b/synapse/app/homeserver.py
index 98d0d14a124b..6014adc8509c 100644
--- a/synapse/app/homeserver.py
+++ b/synapse/app/homeserver.py
@@ -411,26 +411,24 @@ async def do_acme() -> bool:
 
         return provision
 
-    @defer.inlineCallbacks
-    def reprovision_acme():
+    async def reprovision_acme():
         """
         Provision a certificate from ACME, if required, and reload the TLS
         certificate if it's renewed.
         """
-        reprovisioned = yield defer.ensureDeferred(do_acme())
+        reprovisioned = await do_acme()
         if reprovisioned:
             _base.refresh_certificate(hs)
 
-    @defer.inlineCallbacks
-    def start():
+    async def start():
         try:
             # Run the ACME provisioning code, if it's enabled.
             if hs.config.acme_enabled:
                 acme = hs.get_acme_handler()
                 # Start up the webservices which we will respond to ACME
                 # challenges with, and then provision.
-                yield defer.ensureDeferred(acme.start_listening())
-                yield defer.ensureDeferred(do_acme())
+                await acme.start_listening()
+                await do_acme()
 
                 # Check if it needs to be reprovisioned every day.
                 hs.get_clock().looping_call(reprovision_acme, 24 * 60 * 60 * 1000)
@@ -439,8 +437,8 @@ def start():
             if hs.config.oidc_enabled:
                 oidc = hs.get_oidc_handler()
                 # Loading the provider metadata also ensures the provider config is valid.
-                yield defer.ensureDeferred(oidc.load_metadata())
-                yield defer.ensureDeferred(oidc.load_jwks())
+                await oidc.load_metadata()
+                await oidc.load_jwks()
 
             _base.start(hs, config.listeners)
 
@@ -456,7 +454,7 @@ def start():
                 reactor.stop()
             sys.exit(1)
 
-    reactor.callWhenRunning(start)
+    reactor.callWhenRunning(lambda: defer.ensureDeferred(start()))
 
     return hs