perf ui/tui: Protect windows by ui__lock

Sometimes perf top TUI breaks display with concurrent help/input window
and pr_* messages since they're not protected by ui__lock.

You can check it by pressing (and not releasing) 'h' key on a "perf top
-vvv" TUI session.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1388036284-32342-2-git-send-email-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 16 insertions, 3 deletions

diff --git a/tools/perf/ui/tui/util.c b/tools/perf/ui/tui/util.c
index 092902e30cee..bf890f72fe80 100644
--- a/tools/perf/ui/tui/util.c
+++ b/tools/perf/ui/tui/util.c
@@ -92,6 +92,8 @@ int ui_browser__input_window(const char *title, const char *text, char *input,
                 t = sep + 1;
         }
 
+        pthread_mutex_lock(&ui__lock);
+
         max_len += 2;
         nr_lines += 8;
         y = SLtt_Screen_Rows / 2 - nr_lines / 2;
@@ -120,13 +122,19 @@ int ui_browser__input_window(const char *title, const char *text, char *input,
         SLsmg_write_nstring((char *)exit_msg, max_len);
         SLsmg_refresh();
 
+        pthread_mutex_unlock(&ui__lock);
+
         x += 2;
         len = 0;
         key = ui__getch(delay_secs);
         while (key != K_TIMER && key != K_ENTER && key != K_ESC) {
+                pthread_mutex_lock(&ui__lock);
+
                 if (key == K_BKSPC) {
-                        if (len == 0)
+                        if (len == 0) {
+                                pthread_mutex_unlock(&ui__lock);
                                 goto next_key;
+                        }
                         SLsmg_gotorc(y, x + --len);
                         SLsmg_write_char(' ');
                 } else {
@@ -136,6 +144,8 @@ int ui_browser__input_window(const char *title, const char *text, char *input,
                 }
                 SLsmg_refresh();
 
+                pthread_mutex_unlock(&ui__lock);
+
                 /* XXX more graceful overflow handling needed */
                 if (len == sizeof(buf) - 1) {
                         ui_helpline__push("maximum size of symbol name reached!");
@@ -174,6 +184,8 @@ int ui__question_window(const char *title, const char *text,
                 t = sep + 1;
         }
 
+        pthread_mutex_lock(&ui__lock);
+
         max_len += 2;
         nr_lines += 4;
         y = SLtt_Screen_Rows / 2 - nr_lines / 2,
@@ -195,6 +207,9 @@ int ui__question_window(const char *title, const char *text,
         SLsmg_gotorc(y + nr_lines - 1, x);
         SLsmg_write_nstring((char *)exit_msg, max_len);
         SLsmg_refresh();
+
+        pthread_mutex_unlock(&ui__lock);
+
         return ui__getch(delay_secs);
 }
 
@@ -215,9 +230,7 @@ static int __ui__warning(const char *title, const char *format, va_list args)
         if (vasprintf(&s, format, args) > 0) {
                 int key;
 
-                pthread_mutex_lock(&ui__lock);
                 key = ui__question_window(title, s, "Press any key...", 0);
-                pthread_mutex_unlock(&ui__lock);
                 free(s);
                 return key;
         }