From b231c423b59a75dd1f6d219ed9464e8edd96789c Mon Sep 17 00:00:00 2001
From: Yang Gao <6821729+criyle@users.noreply.github.com>
Date: Sun, 21 Jan 2024 17:26:22 +0800
Subject: [PATCH] judge: optimize lock (#715)

---
 packages/hydrojudge/src/utils.ts | 17 +++++++++++------
 1 file changed, 11 insertions(+), 6 deletions(-)

diff --git a/packages/hydrojudge/src/utils.ts b/packages/hydrojudge/src/utils.ts
index f30f99dfb..2f32e0f5c 100644
--- a/packages/hydrojudge/src/utils.ts
+++ b/packages/hydrojudge/src/utils.ts
@@ -1,6 +1,6 @@
 import path from 'path';
 import { parse } from 'shell-quote';
-import { fs, sleep } from '@hydrooj/utils';
+import { fs } from '@hydrooj/utils';
 import { FormatError } from './error';
 
 const EMPTY_STR = /^[ \r\n\t]*$/i;
@@ -8,16 +8,21 @@ const EMPTY_STR = /^[ \r\n\t]*$/i;
 export const cmd = parse;
 
 export namespace Lock {
-    const data = {};
+    const queue: Record<string, Array<(res?: any) => void>> = {};
 
     export async function acquire(key: string) {
-        // eslint-disable-next-line no-await-in-loop
-        while (data[key]) await sleep(100);
-        data[key] = true;
+        if (!queue[key]) {
+            queue[key] = [];
+        } else {
+            await new Promise((resolve) => {
+                queue[key].push(resolve);
+            });
+        }
     }
 
     export function release(key: string) {
-        data[key] = false;
+        if (!queue[key].length) delete queue[key];
+        else queue[key].shift()();
     }
 }