Re: question on debug hooks

[Paul K <paulclinger@...>]

Hi Thijs,

> Now when running with the different debug mask and count values I expected to see large differences in both counters. But there aren't.
...
>   debug.sethook(hook, mask, count)

I think mask and count are mutually exclusive; in other words, if you
have "c", 100, it doesn't mean that it will be called every 100th
"call" event. I may be mistaken, but last time I checked, count
behaves like a line event with a threshold.

So, sethook(hook, "r", 100) is the same as sethook(hook, "r"). If you
want to get every Nth statement, then try sethook(hook, "", N):

test("", nil)
test("", 100)
test("", 1000)
test("", 50000)

With		nil
    loop count :	4036736
    check count:	0
With		100
    loop count :	3575464
    check count:	335199
With		1000
    loop count :	3100648
    check count:	28017
With		50000
    loop count :	4043297
    check count:	727

Paul.

On Fri, Apr 5, 2013 at 9:33 AM, Thijs Schreijer <thijs@thijsschreijer.nl> wrote:
> List,
>
> I have some behavior I can't explain using a debug hook.
> I created a small test. Both the function running and the debug hook only contain a counter.
> Now when running with the different debug mask and count values I expected to see large differences in both counters. But there aren't.
>
> These are the mask and count values and the counts returned:
> With    c       nil
>     loop count :        2888804
>     check count:        2888813
> With    c       100
>     loop count :        2219481
>     check count:        2404448
> With    c       1000
>     loop count :        2480837
>     check count:        2493768
> With    c       50000
>     loop count :        2410984
>     check count:        2411308
> With    r       nil
>     loop count :        2229461
>     check count:        2229473
> With    r       100
>     loop count :        2019846
>     check count:        2188178
> With    r       1000
>     loop count :        2162406
>     check count:        2173679
> With    r       50000
>     loop count :        2325529
>     check count:        2325842
> With    l       nil
>     loop count :        2111964
>     check count:        2111971
> With    l       100
>     loop count :        2001379
>     check count:        2168168
> With    l       1000
>     loop count :        2106344
>     check count:        2117323
> With    l       50000
>     loop count :        2089613
>     check count:        2089893
>
> Especially with values "l" and 50000, I would have expected the debug counter to be far lower than the loop counter.
> What am I missing? Any help is appreciated.
>
> Thijs
>
> Test script below
>
>
> local gettime = require("socket").gettime
> local t, loopcount, checkcount
>
> local loop = function()
>   while t+1>gettime() do loopcount = loopcount + 1 end
> end
>
> local hook = function() checkcount = checkcount + 1 end
>
> local test = function(mask, count)
>   loopcount = 0
>   checkcount = 0
>   t = gettime()
>   debug.sethook(hook, mask, count)
>   loop()
>   print("With",mask,count)
>   print("    loop count :",loopcount)
>   print("    check count:", checkcount)
> end
>
> test("c", nil)
> test("c", 100)
> test("c", 1000)
> test("c", 50000)
> test("r", nil)
> test("r", 100)
> test("r", 1000)
> test("r", 50000)
> test("l", nil)
> test("l", 100)
> test("l", 1000)
> test("l", 50000)
>
>
>
>
>