Infinite Loop using function .call()

[enricoscoda]

The following code:

var c = function() {
    return c.call();
}
c();

doesn't stop even if I limit recursion and block code after 10 seconds using instruction observer:

cx.setInstructionObserverThreshold(10000);
// limit recursion...
cx.setMaximumInterpreterStackDepth(1000);

[gbrail]

When you call "setInstructionObserverThreshold," it just inserts code that
calls Context.observeInstructionCount() every N instructions. The default
implementation of that function does nothing.

If you want to actually do something like throw an exception, then you need
to create a subclass of Context and override that method:

http://mozilla.github.io/rhino/javadoc/org/mozilla/javascript/Context.html#observeInstructionCount(int)

(Typically you do this by overriding ContextFactory to create your own
subclass of Context.)

Then, whatever exception you throw will percolate up to the caller.

Finally, I am pretty sure that "MaximumInterpreterStackDepth" only affects
the code if you are running in interpreted mode, which would only happen if
you explicitly called "setOptimizationLevel" to set the level to -1. The
default is 0, so the code is compiled.

On Tue, Apr 21, 2015 at 9:12 AM, EnricoScoda [email protected]
wrote:

The following code:
var c = function() {
return c.call();
}
c();
doesn't stop even if I limit recursion and block code after 10 seconds
using instruction observer:
cx.setInstructionObserverThreshold(10000);
// limit recursion...
cx.setMaximumInterpreterStackDepth(1000);

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greg brail | apigee https://apigee.com/ | twitter @gbrail
http://twitter.com/gbrail

[enricoscoda]

Hi Greg,
what you describe is implemented in my code and works pretty well in common cases (long evaluations or deep recursions). I played more with it. The following throws "Exceeded maximum stack depth":

var c = function() {
   c();
}
c();

instead this one goes on forever:

var c = function() {
   return c();
}
c();

I can provide you my extended ContextFactory and my extended Context, I you like.
Thanks a lot for the quick response,
Enrico