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Re: [PATCH v2][BZ 14561] Testcase


On 06/04/2013 10:25 AM, OndÅej BÃlka wrote:
> On Tue, Jun 04, 2013 at 09:08:17AM -0400, Carlos O'Donell wrote:
>> This is a good first pass, but we need to make this easier to debug
>> when it fails and when we switch to PASS/FAIL test we should be able
>> to explain which ordering failed.
>>
> I plan to add a breakpoint() function to test which counts times it was
> called before failure(or signal). Then we can output something like:
> 
> FAIL, Type following for debugging:
> 
> SKIP = 2341 gdb command
> b breakpoint_fail
> r
> 
> I could relatively easily add it to most test* with spatch.

Interesting idea.

>> Each of the `return 1'; needs to be able to print the ordering
>> which lead to the failure (since it might be intermittent).
>>
>> If that's too difficult to do then I suggest manually (using
>> a script) unrolling this loop into a static ordering that can
>> use distinct messages for each failure state.
>>
>> Feel free to compact the error message printout to something
>> like: "FAIL: Order was rRr.\n"
>>
> I decided to print sequence of calls.

I like that. Thanks.

> Here is v2.
> 
> 	* bug-srand-srandom-dependency.c: New file.
> 	* Makefile (tests): Add it.
> 
> ---
>  stdlib/Makefile                       |    3 +-
>  stdlib/bug-srand-srandom-dependency.c |   86 +++++++++++++++++++++++++++++++++
>  2 files changed, 88 insertions(+), 1 deletion(-)
>  create mode 100644 stdlib/bug-srand-srandom-dependency.c
> 
> diff --git a/stdlib/Makefile b/stdlib/Makefile
> index 17d80e0..9433cda 100644
> --- a/stdlib/Makefile
> +++ b/stdlib/Makefile
> @@ -71,7 +71,8 @@ tests		:= tst-strtol tst-strtod testmb testrand testsort testdiv   \
>  		   tst-makecontext2 tst-strtod6 tst-unsetenv1		    \
>  		   tst-makecontext3 bug-getcontext bug-fmtmsg1		    \
>  		   tst-secure-getenv tst-strtod-overflow tst-strtod-round   \
> -		   tst-tininess tst-strtod-underflow tst-tls-atexit
> +		   tst-tininess tst-strtod-underflow tst-tls-atexit         \
> +		   bug-srand-srandom-dependency
>  tests-static	:= tst-secure-getenv
>  
>  modules-names	= tst-tls-atexit-lib
> diff --git a/stdlib/bug-srand-srandom-dependency.c b/stdlib/bug-srand-srandom-dependency.c
> new file mode 100644
> index 0000000..2ed5261
> --- /dev/null
> +++ b/stdlib/bug-srand-srandom-dependency.c
> @@ -0,0 +1,86 @@
> +/* Test that srand and srandom do not interact.

Mention BZ#.

> +   Copyright (C) 2013 Free Software Foundation, Inc.
> +   This file is part of the GNU C Library.
> +
> +   The GNU C Library is free software; you can redistribute it and/or
> +   modify it under the terms of the GNU Lesser General Public
> +   License as published by the Free Software Foundation; either
> +   version 2.1 of the License, or (at your option) any later version.
> +
> +   The GNU C Library is distributed in the hope that it will be useful,
> +   but WITHOUT ANY WARRANTY; without even the implied warranty of
> +   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
> +   Lesser General Public License for more details.
> +
> +   You should have received a copy of the GNU Lesser General Public
> +   License along with the GNU C Library; if not, see
> +   <http://www.gnu.org/licenses/>.  */
> +
> +#include <stdio.h>
> +#include <stdlib.h>
> +
> +int
> +do_test (void)
> +{
> +  char buf[1000], *p;

Big enough?

> +#define FAIL {                                                                \
> +    fputs ("Inconsisted results for sequence:\n",stderr);                     \
> +    fputs (buf, stderr);                                                      \
> +    return 1;                                                                 \
> +}

Please make this a function so you can easily put a breakpoint on it.

> +  int rand1, rand2;
> +  int random1, random2;
> +
> +  srand (43);
> +  rand1 = rand ();
> +  rand2 = rand ();
> +  srandom (42);
> +  random1 = random ();
> +  random2 = random ();
> +  /* The six lines above are sequentialy ordered. We try interleave rand and 
> +     random parts in all possible ways and check if they give same results.   */
> +  for (int com = 0; com < 64; com++)
> +    {
> +      p = buf;
> +      int randstate = 0, randomstate = 0;
> +      for (int i = 0; i < 6; i++)
> +	if (com & (1 << i))
> +	  {
> +	    if (randstate == 0)
> +	      p += sprintf (p, "srand(43);\n");
> +	    if (randstate == 1)
> +	      p += sprintf (p, "rand();\n");
> +	    if (randstate == 2)
> +	      p += sprintf (p, "rand();\n");
> +
> +	    if (randstate == 0)
> +	      srand (43);
> +	    if (randstate == 1 && rand1 != rand ())
> +	      FAIL;
> +	    if (randstate == 2 && rand2 != rand ())
> +	      FAIL;
> +	    randstate++;
> +	  }
> +	else
> +	  {
> +	    if (randomstate == 0)
> +	      p += sprintf (p, "srandom(42);\n");
> +	    if (randomstate == 1)
> +	      p += sprintf (p, "random();\n");
> +	    if (randomstate == 2)
> +	      p += sprintf (p, "random();\n");
> +
> +	    if (randomstate == 0)
> +	      srandom (42);
> +	    if (randomstate == 1 && random1 != random ())
> +	      FAIL;
> +	    if (randomstate == 2 && random2 != random ())
> +	      FAIL;
> +	    randomstate++;
> +	  }
> +    }
> +  return 0;
> +}
> +
> +#define TEST_FUNCTION   do_test ()
> +#include "../test-skeleton.c"
> 

Looks good to me with above two changes and proof 
that 1000 bytes is enough, otherwise use 8kb, which
is certainly large enough for 6144 (64*6*13) bytes
of messages.

Cheers,
Carlos.


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