Re: [PATCH v2] perf tools: Make Ctrl-C stop processing on TUI

[Arnaldo Carvalho de Melo <acme@kernel.org>]

Em Fri, May 29, 2015 at 09:53:44PM +0900, Namhyung Kim escreveu:
> It was inconvenient that perf cannot be quit with SIGINT during
> processing samples on TUI especially for large data files.
> 
> This was because the first argument of SLang_init_tty(), abort_char,
> being 0.  The manual says it's the ascii value of the control
> character that will be used to generate the interrupt signal [1].
> Passing -1 means to use the default value (Ctrl-C).
> 
> However, after processing samples, Ctrl-C was used to in other cases as
> well - like stepping back from annotate.  So recover the original
> behavior after processing.

Right, but the way this was implemented it is error prone, I think...

I.e. better would be to enclose whatever section of code we want to be
able to interrupt with control+C with something like:

  ui__control_c_terminates(true);

  process events, etc.

  ui__control_c_terminates(false);

Or some more suitable name, couldn't think right now of any that would
reuse something well established...

The way you implemented it, as soon as we implement a new browser, we
will have to recall this detail to have Control+C working as it always
worked on tools/perf, i.e. not terminating it.

- Arnaldo
 
> [1] http://jedsoft.org/slang/doc/html/cslang-6.html#ss6.1
> 
> Signed-off-by: Namhyung Kim <namhyung@kernel.org>
> ---
>  tools/perf/ui/browsers/annotate.c | 4 ++++
>  tools/perf/ui/browsers/hists.c    | 4 ++++
>  tools/perf/ui/tui/setup.c         | 2 +-
>  3 files changed, 9 insertions(+), 1 deletion(-)
> 
> diff --git a/tools/perf/ui/browsers/annotate.c b/tools/perf/ui/browsers/annotate.c
> index e5250eb2dd57..acb0e23b138e 100644
> --- a/tools/perf/ui/browsers/annotate.c
> +++ b/tools/perf/ui/browsers/annotate.c
> @@ -838,6 +838,10 @@ int map_symbol__tui_annotate(struct map_symbol *ms, struct perf_evsel *evsel,
>  int hist_entry__tui_annotate(struct hist_entry *he, struct perf_evsel *evsel,
>  			     struct hist_browser_timer *hbt)
>  {
> +	/* reset abort key so that it can get Ctrl-C as a key */
> +	SLang_reset_tty();
> +	SLang_init_tty(0, 0, 0);
> +
>  	return map_symbol__tui_annotate(&he->ms, evsel, hbt);
>  }
>  
> diff --git a/tools/perf/ui/browsers/hists.c b/tools/perf/ui/browsers/hists.c
> index f981cb8f0158..e64893f2fd7f 100644
> --- a/tools/perf/ui/browsers/hists.c
> +++ b/tools/perf/ui/browsers/hists.c
> @@ -1741,6 +1741,10 @@ static int perf_evsel__hists_browse(struct perf_evsel *evsel, int nr_events,
>  	if (browser == NULL)
>  		return -1;
>  
> +	/* reset abort key so that it can get Ctrl-C as a key */
> +	SLang_reset_tty();
> +	SLang_init_tty(0, 0, 0);
> +
>  	if (min_pcnt) {
>  		browser->min_pcnt = min_pcnt;
>  		hist_browser__update_nr_entries(browser);
> diff --git a/tools/perf/ui/tui/setup.c b/tools/perf/ui/tui/setup.c
> index b77e1d771363..60d1f29b4b50 100644
> --- a/tools/perf/ui/tui/setup.c
> +++ b/tools/perf/ui/tui/setup.c
> @@ -129,7 +129,7 @@ int ui__init(void)
>  	err = SLsmg_init_smg();
>  	if (err < 0)
>  		goto out;
> -	err = SLang_init_tty(0, 0, 0);
> +	err = SLang_init_tty(-1, 0, 0);
>  	if (err < 0)
>  		goto out;
>  
> -- 
> 2.4.0