Re: [PATCH v3 09/18] perf ui: Update use of pthread mutex

[Namhyung Kim <namhyung@kernel.org>]

On Fri, Aug 26, 2022 at 11:53 AM Adrian Hunter <adrian.hunter@intel.com> wrote:
> Below seems adequate for now, at least logically, but maybe it
> would confuse clang thread-safety analysis?

I think it's not just about locks, the exit_browser should bail out early
if the setup code was not called.

Thanks,
Namhyung


>
> diff --git a/tools/perf/ui/setup.c b/tools/perf/ui/setup.c
> index 25ded88801a3..6d81be6a349e 100644
> --- a/tools/perf/ui/setup.c
> +++ b/tools/perf/ui/setup.c
> @@ -73,9 +73,17 @@ int stdio__config_color(const struct option *opt __maybe_unused,
>         return 0;
>  }
>
> +/*
> + * exit_browser() can get called without setup_browser() having been called
> + * first, so it is necessary to keep track of whether ui__lock has been
> + * initialized.
> + */
> +static bool ui__lock_initialized;
> +
>  void setup_browser(bool fallback_to_pager)
>  {
>         mutex_init(&ui__lock);
> +       ui__lock_initialized = true;
>         if (use_browser < 2 && (!isatty(1) || dump_trace))
>                 use_browser = 0;
>
> @@ -118,5 +126,6 @@ void exit_browser(bool wait_for_ok)
>         default:
>                 break;
>         }
> -       mutex_destroy(&ui__lock);
> +       if (ui__lock_initialized)
> +               mutex_destroy(&ui__lock);
>  }
>