From ad37eae8694af76485e3d598dfa92f60341e4280 Mon Sep 17 00:00:00 2001
From: Charles Hall <charles@computer.surgery>
Date: Tue, 24 Sep 2024 20:05:18 -0700
Subject: [PATCH] use OnceLock instead of RwLock for SERVICES

It actually has the semantics we need. Until we get rid of SERVICES.
---
 src/service.rs | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/src/service.rs b/src/service.rs
index 4bf7c5e2..c2dcb0f8 100644
--- a/src/service.rs
+++ b/src/service.rs
@@ -1,6 +1,6 @@
 use std::{
     collections::{BTreeMap, HashMap},
-    sync::{Arc, Mutex as StdMutex, RwLock as StdRwLock},
+    sync::{Arc, Mutex as StdMutex, OnceLock},
 };
 
 use lru_cache::LruCache;
@@ -22,14 +22,11 @@ pub(crate) mod transaction_ids;
 pub(crate) mod uiaa;
 pub(crate) mod users;
 
-static SERVICES: StdRwLock<Option<&'static Services>> = StdRwLock::new(None);
+static SERVICES: OnceLock<&'static Services> = OnceLock::new();
 
 /// Convenient access to the global [`Services`] instance
 pub(crate) fn services() -> &'static Services {
-    SERVICES
-        .read()
-        .unwrap()
-        .expect("SERVICES should be initialized when this is called")
+    SERVICES.get().expect("`Services::install` should have been called first")
 }
 
 pub(crate) struct Services {
@@ -166,7 +163,10 @@ impl Services {
 
     /// Installs `self` to be globally accessed via [`services`]
     pub(crate) fn install(self) {
-        *SERVICES.write().unwrap() = Some(Box::leak(Box::new(self)));
+        assert!(
+            SERVICES.set(Box::leak(Box::new(self))).is_ok(),
+            "Services::install was called more than once"
+        );
     }
 
     async fn memory_usage(&self) -> String {