fast/workers/worker-cloneport.html

<body>
<p>Test MessagePort messaging/entangle/detangle across threads. Should print "SUCCESS" when done.</p>
<div id=result></div>
<script>
function log(message)
{
    document.getElementById("result").innerHTML += message + "<br>";
}

if (window.testRunner) {
    testRunner.dumpAsText();
    testRunner.waitUntilDone();
}


var channel = new MessageChannel();
var numMessages = 50000;

// Create a channel which we will use to clone and re-clone one end of a
// MessageChannel.
var cloneChannel = new MessageChannel();
var stopCloning = false;
cloneChannel.port1.onmessage = cloneChannel.port2.onmessage = resendPort;
cloneChannel.port1.start();
cloneChannel.port2.start();
cloneChannel.port1.postMessage("", [channel.port2]);

// Create worker with other end of port and have it send messages back to us
// while we clone our end of the port repeatedly.
var worker = new Worker("resources/worker-cloneport.js");
worker.postMessage("postBack " + numMessages, [channel.port1]);

// Test posting back 50000 messages, make sure ordering is fine
worker.onmessage = function(evt) {
    if (evt.data == "postBackDone") {
        stopCloning = true;
    } else {
        // Log message from worker
        log(evt.data);
    }
}

// Keep cloning the passed port until we're told to stop.
function resendPort(evt)
{
    if (!evt.ports)
        log("FAIL: evt.ports not set");
    if (evt.ports.length != 1)
        log("FAIL: ports.length = " + evt.ports.length);

    if (!stopCloning) {
        evt.target.postMessage("", evt.ports);
    } else {
        // Make sure the messages arrived in order.
        var itemNum = 0;
        // Queue up a task to execute once the messages have been processed. The timeout value is set fairly large to account for Chromium's different message delivery architecture.
        // This only fires in the case of a test failure, so it does not slow down test running.
        var timer = setTimeout(function() {
            log("FAILURE: Received: " + itemNum + " events - expected: " + numMessages);
        }, 1000);
        evt.ports[0].onmessage = function(event) {
            var done = false;
            if (event.data == itemNum) {
                itemNum++;
                if (itemNum == numMessages) {
                    log("SUCCESS - received " + numMessages + " messages.");
                    done = true;
                }
            } else {
                log("FAILURE: Out of order message: expected #: " + itemNum + ", received: " + event.data);
                done = true;
            }
            clearTimeout(timer);
            if (done) {
                gc();
                setTimeout(reportDone, 100);  // Make sure no unexpected events come in.
            }
        }
        evt.ports[0].start();
    }
}

function gc()
{
    if (window.GCController)
        return GCController.collect();

    for (var i = 0; i < 10000; i++) { // force garbage collection (FF requires about 9K allocations before a collect).
        var s = new String("abc");
    }
}
function reportDone()
{
     log("DONE");
     if (window.testRunner)
         testRunner.notifyDone();
}

</script>
</body>
</html>