Re: [Valgrind-users] using valgrind to debug uninitialized mem in servern

[Tom H. <to...@co...>]

On 04/02/2021 10:57, Matthias Apitz wrote:
> El día jueves, febrero 04, 2021 a las 09:48:23a. m. +0000, Tom Hughes escribió:
> 
>> On 04/02/2021 09:26, Matthias Apitz wrote:
>>
>>> At the moment we use the following "trick": the librarian runs in
>>> parallel to the client on the desktop a second window with a "tail -f ..."
>>> on valgrinds log file (STDOUT) and the full screen is recorded with
>>> Microsoft teams functionality. So we can use the timestamps in the log
>>> to go to the replay of the recording and can see what the user did
>>> exactly, which data was entered and which button pressed etc.
>>>
>>> Are there other ideas to bring together the valgrind log and the usage
>>> of the application?
>>
>> You could instrument the request processing logic to log details
>> of the request if any errors are detected while processing it, so
>> something like:
>>
>>    #include "valgrind/valgrind.h"
>>
>>    return_type process_request(...)
>>    {
>>      int errors = VALGRIND_COUNT_ERRORS;
>>
>>      // process request as normal
>>
>>      if (VALGRIND_COUNT_ERRORS > errors)
>>      {
>>        VALGRIND_PRINTF("Saw errors processing request %s", request_name);
>>      }
>>    }
>>
>> Obviously you can change it to log whatever details you want.
> 
> Thanks, this looks like a good plan!
> 
> The above are macros, are there additional shared libs to link with our
> process?

No - the valgrind client directives work by generating a special
sequence of assembly language instructions that is spotted by the
valgrind virtual machine and causes valgrind to generate a call to
an internal routine.

Tom

-- 
Tom Hughes (to...@co...)
http://compton.nu/