我已尝试查看 web-worker 文档，虽然我没有找到我要找的东西，但文档也不是很好，所以我想我只是问问它。
我正在使用 Cordova 开发移动应用程序与外部设备对话。我需要每秒向外部设备发送一些命令。为此，我设置了 Web Workers，它基本上相当于 JavaScript 中的线程。但是有一个命令，要工作，必须转弯外部设备。也就是说，如果设备在尝试处理它时收到任何其他命令，该命令将失败。为此，我只想暂停我的线程。
在 Java 中这很容易。有一个 public void thread.suspend()，然后是 thread.resume()。我的自然倾向是 Web Workers 会将此作为默认功能。 Worker.suspend()、worker.resume()，但我找不到任何文档支持 Workers 有这个想法，尽管这是对多线程的普遍期望。有这样的固有功能吗？如果没有，是否有实现类似功能的最佳实践？
最佳答案
这段代码展示了如何
- 创建三个网络 worker
- 从网络 worker 那里获取计数器值
- 暂停网络 worker
- 检测所有三个 web worker 何时停止
- 重启网络 worker
由于 StackOverflow 片段的限制，网络 worker 代码是内联的。
function getInlineJS() {
var js = $('[type="javascript/worker"]').text();
var blob = new Blob([js], {"type": "text/plain"});
return URL.createObjectURL(blob);
}
var worker_list = [];
var worker_num = 3;
var pause_count = null;
function create_workers() {
var index;
for (index = 0; index < worker_num; index++) {
var web_worker = new Worker(getInlineJS());
var counter_selector = '#counter' + (index + 1);
(function(selector) {
web_worker.onmessage = function(event) {
var paused = event.data['paused'];
if (paused) {
pause_count++;
}
if (pause_count == worker_num) {
// At this point we know the workers have all stopped
$('#pause_count').text(pause_count);
}
var counter = event.data['counter'];
$(selector).text(counter);
}
})(counter_selector);
worker_list.push(web_worker);
}
}
/**
* Send a bogus message to get the workers to send their counters
*/
function update_counters() {
var index;
for (index = 0; index < worker_num; index++) {
var message = {'index': index};
worker_list[index].postMessage(message);
}
}
/**
* Send the pause flag to the workers
* @param pause_state
*/
function pause_counters(pause_state) {
var index;
for (index = 0; index < worker_num; index++) {
var message = {'pause_flag': pause_state};
worker_list[index].postMessage(message);
}
}
var pause_state = false;
$(document).ready(function() {
create_workers();
setInterval(update_counters, 1000);
$('#pause').on('click', function() {
pause_state = !pause_state;
if (pause_state) {
pause_count = 0;
}
else {
$('#pause_count').text('');
}
pause_counters(pause_state);
$('#pause').text(pause_state ? 'Start' : 'Stop');
});
});<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Web Worker</title>
</head>
<body>
<div class="counter">
Counter 1: <span id="counter1"></span>
</div>
<div class="counter">
Counter 2: <span id="counter2"></span>
</div>
<div class="counter">
Counter 3: <span id="counter3"></span>
</div>
<div class="button">
<button id="pause" type="button">Stop</button>
</div>
<div>
Pause Count: <span id="pause_count"></span>
</div>
</body>
<script src="https://code.jquery.com/jquery-3.1.1.js"
integrity="sha256-16cdPddA6VdVInumRGo6IbivbERE8p7CQR3HzTBuELA="
crossorigin="anonymous"></script>
<script src="sync.js"></script>
<script type="javascript/worker">
var pause_flag = false;
var counter = 0;
function run_command() {
if (!pause_flag) {
counter++;
}
}
var interval = setInterval(run_command, 1000);
onmessage = function(event) {
if ('pause_flag' in event.data) {
pause_flag = event.data['pause_flag'];
}
var message = {
"paused": pause_flag,
"counter": counter
};
postMessage(message);
};
</script>
</html>关于javascript - 如何暂停网络 worker ，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/40181746/