OSSecureFileWrapper/src/lock.ts

export type Release = { release: () => void };
export default class Lock {
   private _locked: boolean = false;
   get locked() {
      return this._locked;
   }
   private toCome: (() => void)[] = [];

   constructor() {
      this.release = this.release.bind(this);
   }

   async getLock(): Promise<Release> {
      if (!this._locked) return { release: this.lock() };
      else {
         return new Promise<Release>((resolve) => {
            this.toCome.push(() => {
               resolve({ release: this.lock() });
            })
         })
      }
   }

   private lock() {
      this._locked = true;
      return this.release;
   }

   private async release() {
      if (this.toCome.length > 0) {
         this.toCome.shift()();
      } else {
         this._locked = false;
      }
   }
}