wip

bindings/javascript/packages/common/async-lock.ts

@@ -0,0 +1,29 @@
+export class AsyncLock {
+    locked: boolean;
+    queue: any[];
+    constructor() {
+        this.locked = false;
+        this.queue = []
+    }
+    async acquire() {
+        if (!this.locked) {
+            this.locked = true;
+            return Promise.resolve();
+        } else {
+            const block = new Promise(resolve => { this.queue.push(resolve) });
+            return block;
+        }
+    }
+    release() {
+        if (this.locked == false) {
+            throw new Error("invalid state: lock was already unlocked");
+        }
+        const item = this.queue.shift();
+        if (item != null) {
+            this.locked = true;
+            item();
+        } else {
+            this.locked = false;
+        }
+    }
+}