Set-up timeouts on thread-related unittests

[Steven Schveighoffer via Digitalmars-d]

On Fri, 20 Jun 2014 14:30:50 -0400, Sean Kelly <sean at invisibleduck.org>  
wrote:

> On Friday, 20 June 2014 at 18:24:21 UTC, Steven Schveighoffer
> wrote:
>>
>> No, I mean that druntime would run all unit tests with an expectation  
>> that each unit test should time out after N seconds.
>
> I'd be more inclined to have the test runner kill the process if
> it takes more than N seconds to complete and call that a test
> failure.  Figuring out something reasonable to do in the unit
> tester within Druntime would be difficult.

Timing individual tests is more likely to be accurate than timing the  
whole set of unit tests. A slow machine could easily double or triple the  
time the whole thing takes, and it would be difficult to pinpoint a  
reasonable time that all machines would accept. But a single unit test  
block should be really quick, I think 1 second is long enough to say it's  
failed in the vast majority of cases. Of course, if they all take near 1  
second, the total time will be huge. But we are not testing speed, we are  
testing for infinite loops/hangs. The trick is specifying any info to the  
runtime about specific unit tests, we don't have any mechanism to do that.  
UDAs would be perfect.

I don't think it would be that difficult. you just need a separate thread  
(can be written in D but only use C runtime), that exits the process if it  
doesn't get pinged properly. Then the test runner has to ping the thread  
between each test.

-Steve