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Sometimes Fiber.run() returns before yield #178

veselov opened this Issue Jul 16, 2014 · 2 comments


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veselov commented Jul 16, 2014


I was able to distill this. The following code shows run() returning before yield():

var Fiber = require('fibers');
var Future = require('fibers/future');

    console.log("fiber started");
    var f = new Future();
    setTimeout(function(){f.return(0);}, 1000);
    console.log("about to wait");
    console.log("future returned");
console.log("main() done");

The documentation for run() states:

This function will return either the parameter passed to yield(), or the returned value from the fiber's main function.

The documentation for Future.prototype.wait() doesn't say that it will internally make the Fiber yield.

[pawel@druid]~/ws/capi$ node 3.js 
fiber started
about to wait

TypeError: Cannot call method 'reset' of undefined
    at Object.<anonymous> (/home/pawel/ws/capi/3.js:15:10)
    at Module._compile (module.js:456:26)
    at Object.Module._extensions..js (module.js:474:10)
    at Module.load (module.js:356:32)
    at Function.Module._load (module.js:312:12)
    at Function.Module.runMain (module.js:497:10)
    at startup (node.js:119:16)
    at node.js:906:3

node: v0.10.29
fibers: 1.0.1

glasser commented Dec 12, 2014

Yes, but that is how Future works...


laverdet commented Dec 18, 2014

Yeah you should only use Fiber or Future one at a time. I think most users should use only Future, as direct use of Fiber will get you into situations like this.

@laverdet laverdet closed this Dec 18, 2014

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