Re: About use of dlsym()

[Taeung <treeze.taeung@gmail.com>]

Sorry for my poor question.

I didn't know that 'dlopen()', 'dlsym()', 'dlclose()' for DL(Dynamic 
Library).
But I know it.

- Taeung -

On 08/08/2014 03:29 PM, taeung wrote:
> Hello, perf hackers :-)
>
> I'm beginner in perf.
> I'm analysing the sequence of function call and how it was written to 
> update 'report' of gtk view.
>
> This is a thread of a command 'perf report --gtk'
>
> 1. run_argv()
> (in main of perf.c:534)
>
> 2. handle_internal_command()
> (in run_argv of perf.c:420 )
> So far, I've thought this process is to filter what command and option is
>
> 3. cmd_report()
> (in run_builtin of perf.c:319) by function pointer
>
> 4. setup_browser()
> (in cmd_report of builtin-report.c:750)
>
> 5. setup_gtk_browser()
> (in setup_browser of ui/setup.c:74)
>
> 6. perf_gtk__init()
> (in setup_gtk_browser of ui/setup.c:32)
>
> about number 6, I have a question.
>
> In setup_gtk_browser of ui/setup.c: 28 ~ 32,
>
>  28         perf_ui_init = dlsym(perf_gtk_handle, "perf_gtk__init");
>  29         if (perf_ui_init == NULL)
>  30                 goto out_close;
>  31
>  32         if (perf_ui_init() == 0)
>  33                 return 0;
>  34
>
> Why not call directly 'perf_gtk__init()' ?
> Why call the function by function pointer(perf_ui_init) after it is 
> gotten by 'dlsym()' ?
> Why use 'dlsym()' ?
> Is it better than calling directly the function ?
>
> - Taeung -