SharedWorker

属性

Inherits properties from its parent, EventTarget, and implements properties from AbstractWorker.

AbstractWorker.onerror

Is an EventListener that is called whenever an ErrorEvent of type error bubbles through the worker.

SharedWorker.port 只读

返回一个 MessagePort对象，该对象可以用来进行通信和对共享进程进行控制。

构造

SharedWorker()

创建一个执行指定url脚本的共享的web进程。

方法

Inherits methods from its parent, EventTarget, and implements properties from AbstractWorker.

示例

In our Basic shared worker example (run shared worker), we have two HTML pages, each of which uses some JavaScript to perform a simple calculation. The different scripts are using the same worker file to perform the calculation — they can both access it, even if their pages are running inside different windows.

下面的代码展示了如何通过SharedWorker() 方法来创建一个共享进程对象。

var myWorker = new SharedWorker("worker.js");

Both scripts then access the worker through a MessagePort object created using the SharedWorker.port property. If the onmessage event is attached using addEventListener, the port is manually started using its start() method:

myWorker.port.start();

When the port is started, both scripts post messages to the worker and handle messages sent from it using port.postMessage() and port.onmessage, respectively:

first.onchange = function() {
    myWorker.port.postMessage([first.value,second.value]);
    console.log('Message posted to worker');
  }
  second.onchange = function() {
    myWorker.port.postMessage([first.value,second.value]);
    console.log('Message posted to worker');
  }
  myWorker.port.onmessage = function(e) {
    result1.textContent = e.data;
    console.log('Message received from worker');
  }

Inside the worker we use the SharedWorkerGlobalScope.onconnect handler to connect to the same port discussed above. The ports associated with that worker are accessible in the connect event's ports property — we then use MessagePort start() method to start the port, and the onmessage handler to deal with messages sent from the main threads.

onconnect = function(e) {
    var port = e.ports[0];
    port.addEventListener('message', function(e) {
      var workerResult = 'Result: ' + (e.data[0] * e.data[1]);
      port.postMessage(workerResult);
    });
    port.start(); // Required when using addEventListener. Otherwise called implicitly by onmessage setter.
}

规范

浏览器兼容性

更多

• Worker
• Using web workers