worker.ts中如何获取context

let worker = new worker.ThreadWorker('entry/ets/workers/Worker.ts', {name:"first worker in Stage model"}); 
let context = getContext(this) 
worker.postMessage(context);

workerPort.onmessage = function(e : MessageEvents) { 
    let context = e.data 
    console.info(`${TAG} onmessage:${JSON.stringify(context.cacheDir)}`) 
}