Simple echo isolate fails to work when compiled to JavaScript

[sethladd]

This simple isolates example:

import('dart:isolate');

echo() {
  port.receive((msg, reply) => reply.send("Echo: $msg"));
 }

 void main() {
  SendPort sendPort = spawnFunction(echo);
  sendPort.call("Hello, Dart!").then((response) => print(response));
 }

fails to work when compiled to JavaScript. My version of Frog is perhaps a week old, so perhaps it works in the latest and greatest? However, there's another bug with absolute latest Frog so I can't test with bleeding edge.

[sethladd]

Sorry, here's the errors:

Uncaught Error: SECURITY_ERR: DOM Exception 18

_IsolateNatives._newWorker = function(url) {
  return new Worker(url);
Uncaught Error: SECURITY_ERR: DOM Exception 18
}

I've attached the offending JS file.

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Attachment:
isolates2.dart.js (75.92 KB)

[DartBot]

This comment was originally written by zanekam...@gmail.com

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Same problem for me, in both the "stabler" SDK and the bleeding edge one, as of right now.

[sigmundch]

This might be a problem in how you are loading the HTML file in your browser. In particular, are you loading it directly (e.g. a file:/// url) and the .js file is a relative path?

If so, you might be running into browser restricted permissions. Creating a worker requires a url to the script to run in the worker, we derive this url from the original script you use in the page. Browsers like chrome doesn't allow by default creating a worker to a script that sits in your file system (e.g. a file:/// url).

There are a couple ways to work around this:

• if you are using chrome, you can pass '--allow-file-access-from-files' when launching it.
• you can also set up a tiny websever and load the page from it.

[DartBot]

This comment was originally written by zanekam...@gmail.com

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Nope. I'm running from Visual Studio 2010's integrated web server.

[sigmundch]

• Which browser are you using?
• What is the value of 'url' before the call to 'new Worker(url)'?

[DartBot]

This comment was originally written by zanekami...@gmail.com

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I tested in the latest version of Chrome. Dunno the version number; I'll
check that in a bit.

I'll also look into the worker url thing, too. How can I check on that?
Should I just add some debugging code to the complied JS?

[sigmundch]

Adding debugging code to the compiled JS should be enough. You can also set a breakpoint on that line with the debugger (chrome developer tool) and reload the page afterwards.

[dgrove]

This is using the old isolate API, which is no longer supported.

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Added AssumedStale label.