Re: [PATCH v5 7/8] perf hists browser: Add option for runtime switching perf data file

Feng Tang
2012-10-29T16:03:22Z

Hi Arnaldo,

Thanks for the review.

On Mon, Oct 29, 2012 at 12:06:20PM -0200, Arnaldo Carvalho de Melo wrote:
> Em Tue, Oct 30, 2012 at 11:56:08AM +0800, Feng Tang escreveu:
> > + pwd_dir = opendir(pwd);
> > + if (!pwd_dir)
> > + return ret;
> > +
> > + memset(options, 0, sizeof(options));
> > + memset(options, 0, sizeof(abs_path));
> > +
> > + while ((dent = readdir(pwd_dir))) {
> > + char path[PATH_MAX];
> > + u64 magic;
> > + char *name = dent->d_name;
> > + FILE *file;
> > +
> > + if (!(dent->d_type == DT_REG))
> > + continue;
> > +
> > + snprintf(path, PATH_MAX, "%s/%s", pwd, name);
> > +
> > + file = fopen(path, "r");
> > + if (!file)
> > + continue;
> > +
> > + if (fread(&magic, 1, 8, file) < 8)
> > + goto close_file_and_continue;
> > +
> > + if (is_perf_magic(magic)) {
> > + options[nr_options] = strdup(name);
> > + if (!options[nr_options])
> > + goto close_file_and_continue;
>
> Silently not offering a valid file? At this point I think you should
> warn the user and bail out.

Yeah, we should give a warning message and go on with the valid data
files already got.

> > +
> > + abs_path[nr_options] = strdup(path);
> > + if (!abs_path[nr_options]) {
> > + free(options[nr_options]);
> > + goto close_file_and_continue;
> > + }
> > +
> > + nr_options++;
> > + }
> > +
> > +close_file_and_continue:
> > + fclose(file);
> > + if (nr_options >= 256)
> > + break;
>
> Why is this? At the very least a warning has to be given to the user
> that way too many perf.data files are present, so only the first N are
> in the menu.

Ok.

> > + }
> > + closedir(pwd_dir);
> > +
> > + if (nr_options) {
> > + choice = ui__popup_menu(nr_options, options);
> > + if (choice < nr_options && choice >= 0) {
> > + tmp = strdup(abs_path[choice]);
> > + if (tmp) {
> > + if (is_input_name_malloced)
> > + free((void *)input_name);
> > + input_name = tmp;
> > + is_input_name_malloced = true;
> > + ret = 0;
> > + }
>
> Here you return an error, but will the user get any warning on the
> caller of this function if it returns -1?
>
>
> > + /* Switch to another data file */
> > + else if (choice == switch_data) {
> > +do_data_switch:
> > + if (!switch_data_file()) {
> > + key = K_SWITCH_INPUT_DATA;
> > + break;
> > + }
> > + }
>
> ... no, so it will silently continue and the user will get confused.
>

Yes, I will add more ui_warning() in these error/problematic path

Thanks,
Feng