fix(withLock): revert improvements due to behavioral change

src/withLock.ts

@@ -1,4 +1,4 @@
-const locks = new Map<any, Map<string, [queue: (() => void)[], onDelete: (() => void)[]]>>();
+const locks = new Map<any, Map<string, Promise<any>>>();
 
 /**
  * Only allow one instance of the callback to run at a time for a given `scope` and `key`.
@@ -25,38 +25,44 @@ export async function withLock<ReturnType, const ScopeType = any>(
     if (callback == null)
         throw new Error("callback is required");
 
-    if (acquireLockSignal?.aborted)
-        throw acquireLockSignal.reason;
+    while (locks.get(scope)?.has(key)) {
+        if (acquireLockSignal?.aborted)
+            throw acquireLockSignal.reason;
 
-    let keyMap = locks.get(scope);
-    if (keyMap == null) {
-        keyMap = new Map();
-        locks.set(scope, keyMap);
-    }
+        try {
+            if (acquireLockSignal != null) {
+                const acquireLockPromise = createAbortSignalAbortPromise(acquireLockSignal);
+
+                await Promise.race([
+                    acquireLockPromise.promise,
+                    locks.get(scope)?.get(key)
+                ]);
+
+                acquireLockPromise.dispose();
+            } else
+                await locks.get(scope)?.get(key);
+        } catch (err) {
+            // we only need to wait here for the promise to resolve, we don't care about the result
+        }
 
-    let [queue, onDelete] = keyMap.get(key) || [];
-    if (queue != null && onDelete != null)
-        await createQueuePromise(queue, acquireLockSignal);
-    else {
-        queue = [];
-        onDelete = [];
-        keyMap.set(key, [queue, onDelete]);
+        if (acquireLockSignal?.aborted)
+            throw acquireLockSignal.reason;
     }
 
+    const promise = callback.call(scope);
+
+    if (!locks.has(scope))
+        locks.set(scope, new Map());
+
+    locks.get(scope)!.set(key, promise);
+
     try {
-        return await callback.call(scope);
+        return await promise;
     } finally {
-        if (queue.length > 0)
-            queue.shift()!();
-        else {
-            locks.get(scope)?.delete(key);
-
-            if (locks.get(scope)?.size === 0)
-                locks.delete(scope);
+        locks.get(scope)?.delete(key);
 
-            while (onDelete.length > 0)
-                onDelete.shift()!();
-        }
+        if (locks.get(scope)?.size === 0)
+            locks.delete(scope);
     }
 }
 
@@ -70,45 +76,75 @@ export function isLockActive(scope: any, key: string): boolean {
 /**
  * Acquire a lock for a given `scope` and `key`.
  */
-export function acquireLock<S = any, K extends string = string>(
+export async function acquireLock<S = any, K extends string = string>(
     scope: S, key: K, acquireLockSignal?: AbortSignal
 ): Promise<Lock<S, K>> {
-    return new Promise<Lock<S, K>>((accept, reject) => {
-        void withLock(scope, key, acquireLockSignal, () => {
-            let releaseLock: () => void;
-            const promise = new Promise<void>((accept) => {
-                releaseLock = accept;
-            });
+    let releaseLock: (param: null) => void;
 
-            accept({
-                scope,
-                key,
-                dispose() {
-                    releaseLock();
-                },
-                [Symbol.dispose]() {
-                    releaseLock();
-                }
-            });
+    await new Promise((accept, reject) => {
+        void withLock(scope, key, acquireLockSignal, async () => {
+            accept(null);
 
-            return promise;
+            await new Promise((accept) => {
+                releaseLock = accept;
+            });
         })
             .catch(reject);
     });
+
+    return {
+        scope,
+        key,
+        dispose() {
+            releaseLock(null);
+        },
+        [Symbol.dispose]() {
+            releaseLock(null);
+        }
+    };
 }
 
 /**
  * Wait for a lock to be released for a given `scope` and `key`.
  */
 export async function waitForLockRelease(scope: any, key: string, signal?: AbortSignal): Promise<void> {
-    if (signal?.aborted)
-        throw signal.reason;
+    // eslint-disable-next-line no-constant-condition
+    while (true) {
+        if (signal?.aborted)
+            throw signal.reason;
+
+        try {
+            if (signal != null) {
+                const signalPromise = createAbortSignalAbortPromise(signal);
+
+                await Promise.race([
+                    signalPromise.promise,
+                    locks.get(scope)?.get(key)
+                ]);
+
+                signalPromise.dispose();
+            } else
+                await locks.get(scope)?.get(key);
+        } catch (err) {
+            // we only need to wait here for the promise to resolve, we don't care about the result
+        }
 
-    const [queue, onDelete] = locks.get(scope)?.get(key) ?? [];
-    if (queue == null || onDelete == null)
-        return;
+        if (signal?.aborted)
+            throw signal.reason;
+
+        if (locks.get(scope)?.has(key))
+            continue;
+
+        await Promise.resolve(); // wait for a microtask to run, so other pending locks can be registered
 
-    await createQueuePromise(onDelete, signal);
+        if (signal?.aborted)
+            throw signal.reason;
+
+        if (locks.get(scope)?.has(key))
+            continue;
+
+        return;
+    }
 }
 
 export type Lock<S = any, K extends string = string> = {
@@ -118,28 +154,36 @@ export type Lock<S = any, K extends string = string> = {
     [Symbol.dispose](): void
 };
 
-function createQueuePromise(queue: (() => void)[], signal?: AbortSignal) {
-    if (signal == null)
-        return new Promise<void>((accept) => void queue.push(accept));
+function createControlledPromise<T = any>() {
+    let resolve: (value: T | Promise<T>) => void;
+    let reject: (reason?: any) => void;
 
-    return new Promise<void>((accept, reject) => {
-        function onAcquireLock() {
-            signal!.removeEventListener("abort", onAbort);
-            accept();
-        }
+    const promise = new Promise<T>((accept, fail) => {
+        resolve = accept;
+        reject = fail;
+    });
 
-        const queueLength = queue.length;
+    return {
+        promise,
+        resolve: resolve!,
+        reject: reject!
+    };
+}
 
-        function onAbort() {
-            const itemIndex = queue.lastIndexOf(onAcquireLock, queueLength);
-            if (itemIndex >= 0)
-                queue.splice(itemIndex, 1);
+function createAbortSignalAbortPromise(signal: AbortSignal) {
+    const acquireLockPromise = createControlledPromise<void>();
 
-            signal!.removeEventListener("abort", onAbort);
-            reject(signal!.reason);
-        }
+    const onAbort = () => {
+        acquireLockPromise.resolve();
+        signal.removeEventListener("abort", onAbort);
+    };
+    signal.addEventListener("abort", onAbort);
 
-        queue.push(onAcquireLock);
-        signal.addEventListener("abort", onAbort);
-    });
+    return {
+        promise: acquireLockPromise.promise,
+        dispose() {
+            signal.removeEventListener("abort", onAbort);
+        }
+    };
 }
+