perf report: Support multiple events on the TUI

The hists__tty_browse_tree function was created with the loop to print
all events, and its equivalent, hists__tui_browse_tree, was created in a
similar fashion, where it is possible to switch among the multiple
events, if present, using TAB to go the next event, and shift+TAB
(UNTAB) to go to the previous.

The report TUI now shows as the window title the name of the event and a
leak was fixed wrt pstacks.

Cc: Frédéric Weisbecker <[e-mail]>
Cc: Mike Galbraith <[e-mail]>
Cc: Paul Mackerras <[e-mail]>
Cc: Peter Zijlstra <[e-mail]>
Cc: Stephane Eranian <[e-mail]>
Cc: Tom Zanussi <[e-mail]>
LKML-Reference: <new-submission>
Signed-off-by: Arnaldo Carvalho de Melo <[e-mail]>

tools/perf/builtin-report.c

···
 	return ret + fprintf(fp, "\n#\n");
 }
 
+static int hists__tty_browse_tree(struct rb_root *tree, const char *help)
+{
+	struct rb_node *next = rb_first(tree);
+
+	while (next) {
+		struct hists *hists = rb_entry(next, struct hists, rb_node);
+		const char *evname = NULL;
+
+		if (rb_first(&hists->entries) != rb_last(&hists->entries))
+			evname = __event_name(hists->type, hists->config);
+
+		hists__fprintf_nr_sample_events(hists, evname, stdout);
+		hists__fprintf(hists, NULL, false, stdout);
+		fprintf(stdout, "\n\n");
+		next = rb_next(&hists->rb_node);
+	}
+
+	if (sort_order == default_sort_order &&
+	    parent_pattern == default_parent_pattern) {
+		fprintf(stdout, "#\n# (%s)\n#\n", help);
+
+		if (show_threads) {
+			bool style = !strcmp(pretty_printing_style, "raw");
+			perf_read_values_display(stdout, &show_threads_values,
+						 style);
+			perf_read_values_destroy(&show_threads_values);
+		}
+	}
+
+	return 0;
+}
+
 static int __cmd_report(void)
 {
 	int ret = -EINVAL;
···
 		hists = rb_entry(next, struct hists, rb_node);
 		hists__collapse_resort(hists);
 		hists__output_resort(hists);
-		if (use_browser > 0)
-			hists__browse(hists, help, input_name);
-		else {
-			const char *evname = NULL;
-			if (rb_first(&session->hists.entries) !=
-			    rb_last(&session->hists.entries))
-				evname = __event_name(hists->type, hists->config);
-
-			hists__fprintf_nr_sample_events(hists, evname, stdout);
-
-			hists__fprintf(hists, NULL, false, stdout);
-			fprintf(stdout, "\n\n");
-		}
-
 		next = rb_next(&hists->rb_node);
 	}
 
-	if (use_browser <= 0 && sort_order == default_sort_order &&
-	    parent_pattern == default_parent_pattern) {
-		fprintf(stdout, "#\n# (%s)\n#\n", help);
+	if (use_browser > 0)
+		hists__tui_browse_tree(&session->hists_tree, help);
+	else
+		hists__tty_browse_tree(&session->hists_tree, help);
 
-		if (show_threads) {
-			bool style = !strcmp(pretty_printing_style, "raw");
-			perf_read_values_display(stdout, &show_threads_values,
-						 style);
-			perf_read_values_destroy(&show_threads_values);
-		}
-	}
 out_delete:
 	perf_session__delete(session);
 	return ret;

tools/perf/util/hist.h

···
 #ifdef NO_NEWT_SUPPORT
 static inline int hists__browse(struct hists *self __used,
 				const char *helpline __used,
-				const char *input_name __used)
+				const char *ev_name __used)
 {
 	return 0;
 }
+
+static inline int hists__tui_browse_tree(struct rb_root *self __used,
+					 const char *help __used)
+{
+	return 0;
+}
+
 static inline int hist_entry__tui_annotate(struct hist_entry *self __used)
 {
 	return 0;
···
 #else
 #include <newt.h>
 int hists__browse(struct hists *self, const char *helpline,
-		  const char *input_name);
+		  const char *ev_name);
 int hist_entry__tui_annotate(struct hist_entry *self);
+
 #define KEY_LEFT NEWT_KEY_LEFT
 #define KEY_RIGHT NEWT_KEY_RIGHT
+
+int hists__tui_browse_tree(struct rb_root *self, const char *help);
 #endif
 #endif	/* __PERF_HIST_H */

tools/perf/util/newt.c

···
 	newtFormAddHotKey(self->form, 'h');
 	newtFormAddHotKey(self->form, NEWT_KEY_F1);
 	newtFormAddHotKey(self->form, NEWT_KEY_RIGHT);
+	newtFormAddHotKey(self->form, NEWT_KEY_TAB);
+	newtFormAddHotKey(self->form, NEWT_KEY_UNTAB);
 	newtFormAddComponents(self->form, self->tree, NULL);
 	self->selection = newt__symbol_tree_get_current(self->tree);
 
···
 	return he ? he->thread : NULL;
 }
 
-static int hist_browser__title(char *bf, size_t size, const char *input_name,
+static int hist_browser__title(char *bf, size_t size, const char *ev_name,
 			       const struct dso *dso, const struct thread *thread)
 {
 	int printed = 0;
···
 		printed += snprintf(bf + printed, size - printed,
 				    "%sDSO: %s", thread ? " " : "",
 				    dso->short_name);
-	return printed ?: snprintf(bf, size, "Report: %s", input_name);
+	return printed ?: snprintf(bf, size, "Event: %s", ev_name);
 }
 
-int hists__browse(struct hists *self, const char *helpline, const char *input_name)
+int hists__browse(struct hists *self, const char *helpline, const char *ev_name)
 {
 	struct hist_browser *browser = hist_browser__new();
-	struct pstack *fstack = pstack__new(2);
+	struct pstack *fstack;
 	const struct thread *thread_filter = NULL;
 	const struct dso *dso_filter = NULL;
 	struct newtExitStruct es;
 	char msg[160];
-	int err = -1;
+	int key = -1;
 
 	if (browser == NULL)
 		return -1;
···
 
 	ui_helpline__push(helpline);
 
-	hist_browser__title(msg, sizeof(msg), input_name,
+	hist_browser__title(msg, sizeof(msg), ev_name,
 			    dso_filter, thread_filter);
 	if (hist_browser__populate(browser, self, msg) < 0)
 		goto out_free_stack;
···
 		dso = browser->selection->map ? browser->selection->map->dso : NULL;
 
 		if (es.reason == NEWT_EXIT_HOTKEY) {
-			if (es.u.key == NEWT_KEY_F1)
-				goto do_help;
+			key = es.u.key;
 
-			switch (toupper(es.u.key)) {
+			switch (key) {
+			case NEWT_KEY_F1:
+				goto do_help;
+			case NEWT_KEY_TAB:
+			case NEWT_KEY_UNTAB:
+				/*
+				 * Exit the browser, let hists__browser_tree
+				 * go to the next or previous
+				 */
+				goto out_free_stack;
+			default:;
+			}
+
+			key = toupper(key);
+			switch (key) {
 			case 'A':
 				if (browser->selection->map == NULL &&
 				    browser->selection->map->dso->annotate_warned)
···
 				continue;
 			default:;
 			}
-			if (is_exit_key(es.u.key)) {
-				if (es.u.key == NEWT_KEY_ESCAPE) {
+			if (is_exit_key(key)) {
+				if (key == NEWT_KEY_ESCAPE) {
 					if (dialog_yesno("Do you really want to exit?"))
 						break;
 					else
···
 				pstack__push(fstack, &dso_filter);
 			}
 			hists__filter_by_dso(self, dso_filter);
-			hist_browser__title(msg, sizeof(msg), input_name,
+			hist_browser__title(msg, sizeof(msg), ev_name,
 					    dso_filter, thread_filter);
 			if (hist_browser__populate(browser, self, msg) < 0)
 				goto out;
···
 				pstack__push(fstack, &thread_filter);
 			}
 			hists__filter_by_thread(self, thread_filter);
-			hist_browser__title(msg, sizeof(msg), input_name,
+			hist_browser__title(msg, sizeof(msg), ev_name,
 					    dso_filter, thread_filter);
 			if (hist_browser__populate(browser, self, msg) < 0)
 				goto out;
 		}
 	}
-	err = 0;
 out_free_stack:
 	pstack__delete(fstack);
 out:
 	hist_browser__delete(browser);
-	return err;
+	return key;
+}
+
+int hists__tui_browse_tree(struct rb_root *self, const char *help)
+{
+	struct rb_node *first = rb_first(self), *nd = first, *next;
+	int key = 0;
+
+	while (nd) {
+		struct hists *hists = rb_entry(nd, struct hists, rb_node);
+		const char *ev_name = __event_name(hists->type, hists->config);
+
+		key = hists__browse(hists, help, ev_name);
+
+		if (is_exit_key(key))
+			break;
+
+		switch (key) {
+		case NEWT_KEY_TAB:
+			next = rb_next(nd);
+			if (next)
+				nd = next;
+			break;
+		case NEWT_KEY_UNTAB:
+			if (nd == first)
+				continue;
+			nd = rb_prev(nd);
+		default:
+			break;
+		}
+	}
+
+	return key;
 }
 
 static struct newtPercentTreeColors {