Merge remote-tracking branch 'origin/develop' into matrix-org-hotfixes

changelog.d/16063.misc

@@ -0,0 +1 @@
+Fix building the nix development environment on MacOS systems.

changelog.d/16169.bugfix

@@ -0,0 +1 @@
+Fix a rare race that could block new events from being sent for up to two minutes. Introduced in v1.90.0.

flake.lock

@@ -8,16 +8,16 @@
         "pre-commit-hooks": "pre-commit-hooks"
       },
       "locked": {
-        "lastModified": 1690534632,
-        "narHash": "sha256-kOXS9x5y17VKliC7wZxyszAYrWdRl1JzggbQl0gyo94=",
+        "lastModified": 1688058187,
+        "narHash": "sha256-ipDcc7qrucpJ0+0eYNlwnE+ISTcq4m03qW+CWUshRXI=",
         "owner": "cachix",
         "repo": "devenv",
-        "rev": "6568e7e485a46bbf32051e4d6347fa1fed8b2f25",
+        "rev": "c8778e3dc30eb9043e218aaa3861d42d4992de77",
         "type": "github"
       },
       "original": {
         "owner": "cachix",
-        "ref": "main",
+        "ref": "v0.6.3",
         "repo": "devenv",
         "type": "github"
       }

flake.nix

@@ -45,7 +45,7 @@
     # Output a development shell for x86_64/aarch64 Linux/Darwin (MacOS).
     systems.url = "github:nix-systems/default";
     # A development environment manager built on Nix. See https://devenv.sh.
-    devenv.url = "github:cachix/devenv/main";
+    devenv.url = "github:cachix/devenv/v0.6.3";
     # Rust toolchain.
     rust-overlay.url = "github:oxalica/rust-overlay";
   };

synapse/storage/schema/main/delta/80/02_read_write_locks_deadlock.sql.postgres

@@ -1,37 +0,0 @@
-/* Copyright 2023 The Matrix.org Foundation C.I.C
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *    http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
--- To avoid the possibility of a deadlock, lock the
--- `worker_read_write_locks_mode` table so that we serialize inserts/deletes
--- for a specific lock name/key.
-
-CREATE OR REPLACE FUNCTION delete_read_write_lock_parent_before() RETURNS trigger AS $$
-BEGIN
-    -- `PERFORM` is a `SELECT` which discards the rows.
-    PERFORM * FROM worker_read_write_locks_mode
-        WHERE
-            lock_name = OLD.lock_name
-            AND lock_key = OLD.lock_key
-        FOR UPDATE;
-
-    RETURN OLD;
-END
-$$
-LANGUAGE plpgsql;
-
-DROP TRIGGER IF EXISTS delete_read_write_lock_parent_before_trigger ON worker_read_write_locks;
-CREATE TRIGGER delete_read_write_lock_parent_before_trigger BEFORE DELETE ON worker_read_write_locks
-    FOR EACH ROW
-    EXECUTE PROCEDURE delete_read_write_lock_parent_before();

synapse/storage/schema/main/delta/80/04_read_write_locks_deadlock.sql.postgres

@@ -0,0 +1,71 @@
+/* Copyright 2023 The Matrix.org Foundation C.I.C
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+
+-- Remove a previous attempt to avoid deadlocks
+DROP TRIGGER IF EXISTS delete_read_write_lock_parent_before_trigger ON worker_read_write_locks;
+DROP FUNCTION IF EXISTS delete_read_write_lock_parent_before;
+
+
+-- Ensure that we keep `worker_read_write_locks_mode` up to date whenever a lock
+-- is released (i.e. a row deleted from `worker_read_write_locks`). Either we
+-- update the `worker_read_write_locks_mode.token` to match another instance
+-- that has currently acquired the lock, or we delete the row if nobody has
+-- currently acquired a lock.
+CREATE OR REPLACE FUNCTION delete_read_write_lock_parent() RETURNS trigger AS $$
+DECLARE
+    new_token TEXT;
+    mode_row_token TEXT;
+BEGIN
+    -- Only update the token in `_mode` if its our token. This prevents
+    -- deadlocks.
+    --
+    -- We shove the token into `mode_row_token`, as otherwise postgres complains
+    -- we're not using the returned data.
+    SELECT token INTO mode_row_token FROM worker_read_write_locks_mode
+        WHERE
+            lock_name = OLD.lock_name
+            AND lock_key = OLD.lock_key
+            AND token = OLD.token
+        FOR UPDATE;
+
+    IF NOT FOUND THEN
+        RETURN NEW;
+    END IF;
+
+    SELECT token INTO new_token FROM worker_read_write_locks
+        WHERE
+            lock_name = OLD.lock_name
+            AND lock_key = OLD.lock_key
+        LIMIT 1 FOR UPDATE SKIP LOCKED;
+
+    IF NOT FOUND THEN
+        DELETE FROM worker_read_write_locks_mode
+            WHERE lock_name = OLD.lock_name AND lock_key = OLD.lock_key AND token = OLD.token;
+    ELSE
+        UPDATE worker_read_write_locks_mode
+            SET token = new_token
+            WHERE lock_name = OLD.lock_name AND lock_key = OLD.lock_key;
+    END IF;
+
+    RETURN NEW;
+END
+$$
+LANGUAGE plpgsql;
+
+DROP TRIGGER IF EXISTS delete_read_write_lock_parent_trigger ON worker_read_write_locks;
+CREATE TRIGGER delete_read_write_lock_parent_trigger AFTER DELETE ON worker_read_write_locks
+    FOR EACH ROW
+    EXECUTE PROCEDURE delete_read_write_lock_parent();