[erlang-questions] EUnit error test: limit number of processes at runtime

Lukas Larsson <>
Tue May 1 11:56:15 CEST 2012


You could also spawn a slave[1] node in the test with your desired
parameters to test this behaviour. That is how it is done in the
Erlang/OTP test suites.


[1] : http://erlang.org/doc/man/slave.html

On Sat, Apr 28, 2012 at 9:24 PM, Geoff Cant <> wrote:
> From memory there's no way to limit the number of processes allowed aside from the size of the process table. The size of the process table is set at startup and can't be changed, so I guess the answer to your question is No - you have to spawn enough processes to run out. spawn(fun () -> erlang:hibernate(erlang, exit, [normal]) end, []) might help with the memory footprint a bit.
> Cheers,
> -Geoff
> On 2012-04-28, at 10:19 , Christian Kruse wrote:
>> Hi,
>> On 28/04/12 19:11, Kostis Sagonas wrote:
>>>> for an Erlang project I'm working on (Open Source,
>>>> <https://github.com/ckruse/irckerl>  in case someone is curious) I'm
>>>> trying to test a possible error with spawning a process, e.g. maximum
>>>> number of processes reached. Since I don't want to spawn>  32k
>>>> processes for each test run, I'd like to limit the number of possible
>>>> processes for this test only.
>>>> Is this possible? Or is there another solution I can use to test such
>>>> an error case?
>>> Have you considered using the +P option of erl?
>> Yes, but since I want to reduce this limit only for one specific test
>> it is not really a good solution. I would have to set the limit to a
>> specific number of processes for all tests and exceed that limit in
>> the error test. Of course it can be much lower than 32k processes for
>> the test run, but it would be much nicer to limit it only for this one
>> test.
>> Greetings,
>> CK
>> _______________________________________________
>> erlang-questions mailing list
>> http://erlang.org/mailman/listinfo/erlang-questions
> --
> Geoff Cant
> _______________________________________________
> erlang-questions mailing list
> http://erlang.org/mailman/listinfo/erlang-questions

More information about the erlang-questions mailing list