Use a better mutex

Cargo.lock

@@ -407,6 +407,15 @@ dependencies = [
  "nodrop",
 ]
 
+[[package]]
+name = "async-mutex"
+version = "1.0.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f2158da821e7ba10beee4c01ad1d8f7f49a30675f8761106dd7d569284024d40"
+dependencies = [
+ "event-listener",
+]
+
 [[package]]
 name = "async-trait"
 version = "0.1.31"
@@ -876,6 +885,12 @@ dependencies = [
  "termcolor",
 ]
 
+[[package]]
+name = "event-listener"
+version = "1.0.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0173b36d730a966f1e1aa2a811cc41619aaf50df92df434fdbad0504d39a973d"
+
 [[package]]
 name = "failure"
 version = "0.1.8"
@@ -1965,6 +1980,7 @@ dependencies = [
  "actix-webfinger",
  "ammonia",
  "anyhow",
+ "async-mutex",
  "async-trait",
  "background-jobs",
  "base64 0.12.1",

Cargo.toml

@@ -20,6 +20,7 @@ actix-webfinger = "0.3.0-alpha.6"
 activitystreams-new = { git = "https://git.asonix.dog/asonix/activitystreams-sketch" }
 activitystreams-ext = { git = "https://git.asonix.dog/asonix/activitystreams-ext" }
 ammonia = "3.1.0"
+async-mutex = "1.0.1"
 async-trait = "0.1.24"
 background-jobs = "0.8.0-alpha.2"
 bytes = "0.5.4"

src/data/media.rs

@@ -1,10 +1,11 @@
 use crate::{db::Db, error::MyError};
 use activitystreams_new::primitives::XsdAnyUri;
+use async_mutex::Mutex;
 use bytes::Bytes;
 use futures::join;
 use lru::LruCache;
 use std::{collections::HashMap, sync::Arc, time::Duration};
-use tokio::sync::{Mutex, RwLock};
+use tokio::sync::RwLock;
 use ttl_cache::TtlCache;
 use uuid::Uuid;