perf ui: Improve handling sigwinch a bit

No need to unblock it at each ui__getch() and also allow other users to
check if a resize is needed, or force an refresh of terminal dimensions.

The 'force' one shouldn't be needed, but its in a slow path, so leave it
like that for now, I'll revisit this another day.

Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-aujchu6yx3bfy64non1rky0w@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

5 files changed, 82 insertions, 47 deletions

diff --git a/tools/perf/util/ui/browser.c b/tools/perf/util/ui/browser.c
index 5359f371d30a..370c4703cec8 100644
--- a/tools/perf/util/ui/browser.c
+++ b/tools/perf/util/ui/browser.c
@@ -4,6 +4,7 @@
 #include "libslang.h"
 #include <newt.h>
 #include "ui.h"
+#include "util.h"
 #include <linux/compiler.h>
 #include <linux/list.h>
 #include <linux/rbtree.h>
@@ -291,53 +292,10 @@ void ui_browser__update_nr_entries(struct ui_browser *browser, u32 nr_entries)
         browser->seek(browser, browser->top_idx, SEEK_SET);
 }
 
-static int ui__getch(int delay_secs)
-{
-        struct timeval timeout, *ptimeout = delay_secs ? &timeout : NULL;
-        fd_set read_set;
-        int err, key;
-
-        FD_ZERO(&read_set);
-        FD_SET(0, &read_set);
-
-        if (delay_secs) {
-                timeout.tv_sec = delay_secs;
-                timeout.tv_usec = 0;
-        }
-
-        err = select(1, &read_set, NULL, NULL, ptimeout);
-
-        if (err == 0)
-                return K_TIMER;
-
-        if (err == -1) {
-                if (errno == EINTR)
-                        return K_RESIZE;
-                return K_ERROR;
-        }
-
-        key = SLang_getkey();
-        if (key != K_ESC)
-                return key;
-
-        FD_ZERO(&read_set);
-        FD_SET(0, &read_set);
-        timeout.tv_sec = 0;
-        timeout.tv_usec = 20;
-        err = select(1, &read_set, NULL, NULL, &timeout);
-        if (err == 0)
-                return K_ESC;
-
-        SLang_ungetkey(key);
-        return SLkp_getkey();
-}
-
 int ui_browser__run(struct ui_browser *self, int delay_secs)
 {
         int err, key;
 
-        pthread__unblock_sigwinch();
-
         while (1) {
                 off_t offset;
 
@@ -351,10 +309,7 @@ int ui_browser__run(struct ui_browser *self, int delay_secs)
                 key = ui__getch(delay_secs);
 
                 if (key == K_RESIZE) {
-                        pthread_mutex_lock(&ui__lock);
-                        SLtt_get_screen_size();
-                        SLsmg_reinit_smg();
-                        pthread_mutex_unlock(&ui__lock);
+                        ui__refresh_dimensions(false);
                         ui_browser__refresh_dimensions(self);
                         __ui_browser__show_title(self, self->title);
                         ui_helpline__puts(self->helpline);
diff --git a/tools/perf/util/ui/progress.c b/tools/perf/util/ui/progress.c
index 68d2c548abe3..295e366b6311 100644
--- a/tools/perf/util/ui/progress.c
+++ b/tools/perf/util/ui/progress.c
@@ -14,6 +14,7 @@ void ui_progress__update(u64 curr, u64 total, const char *title)
         if (use_browser <= 0)
                 return;
 
+        ui__refresh_dimensions(true);
         pthread_mutex_lock(&ui__lock);
         y = SLtt_Screen_Rows / 2 - 2;
         SLsmg_set_color(0);
diff --git a/tools/perf/util/ui/setup.c b/tools/perf/util/ui/setup.c
index 1e6ba06980c4..c4e025fbd6b9 100644
--- a/tools/perf/util/ui/setup.c
+++ b/tools/perf/util/ui/setup.c
@@ -7,10 +7,85 @@
 #include "browser.h"
 #include "helpline.h"
 #include "ui.h"
+#include "util.h"
 #include "libslang.h"
+#include "keysyms.h"
 
 pthread_mutex_t ui__lock = PTHREAD_MUTEX_INITIALIZER;
 
+static volatile int ui__need_resize;
+
+void ui__refresh_dimensions(bool force)
+{
+        if (force || ui__need_resize) {
+                ui__need_resize = 0;
+                pthread_mutex_lock(&ui__lock);
+                SLtt_get_screen_size();
+                SLsmg_reinit_smg();
+                pthread_mutex_unlock(&ui__lock);
+        }
+}
+
+static void ui__sigwinch(int sig __used)
+{
+        ui__need_resize = 1;
+}
+
+static void ui__setup_sigwinch(void)
+{
+        static bool done;
+
+        if (done)
+                return;
+
+        done = true;
+        pthread__unblock_sigwinch();
+        signal(SIGWINCH, ui__sigwinch);
+}
+
+int ui__getch(int delay_secs)
+{
+        struct timeval timeout, *ptimeout = delay_secs ? &timeout : NULL;
+        fd_set read_set;
+        int err, key;
+
+        ui__setup_sigwinch();
+
+        FD_ZERO(&read_set);
+        FD_SET(0, &read_set);
+
+        if (delay_secs) {
+                timeout.tv_sec = delay_secs;
+                timeout.tv_usec = 0;
+        }
+
+        err = select(1, &read_set, NULL, NULL, ptimeout);
+
+        if (err == 0)
+                return K_TIMER;
+
+        if (err == -1) {
+                if (errno == EINTR)
+                        return K_RESIZE;
+                return K_ERROR;
+        }
+
+        key = SLang_getkey();
+        if (key != K_ESC)
+                return key;
+
+        FD_ZERO(&read_set);
+        FD_SET(0, &read_set);
+        timeout.tv_sec = 0;
+        timeout.tv_usec = 20;
+        err = select(1, &read_set, NULL, NULL, &timeout);
+        if (err == 0)
+                return K_ESC;
+
+        SLang_ungetkey(key);
+        return SLkp_getkey();
+}
+
 static void newt_suspend(void *d __used)
 {
         newtSuspend();
diff --git a/tools/perf/util/ui/ui.h b/tools/perf/util/ui/ui.h
index d264e059c829..7b67045479f6 100644
--- a/tools/perf/util/ui/ui.h
+++ b/tools/perf/util/ui/ui.h
@@ -2,7 +2,10 @@
 #define _PERF_UI_H_ 1
 
 #include <pthread.h>
+#include <stdbool.h>
 
 extern pthread_mutex_t ui__lock;
 
+void ui__refresh_dimensions(bool force);
+
 #endif /* _PERF_UI_H_ */
diff --git a/tools/perf/util/ui/util.h b/tools/perf/util/ui/util.h
index afcbc1d99531..e53c3d334903 100644
--- a/tools/perf/util/ui/util.h
+++ b/tools/perf/util/ui/util.h
@@ -3,6 +3,7 @@
 
 #include <stdbool.h>
 
+int ui__getch(int delay_secs);
 int ui__popup_menu(int argc, char * const argv[]);
 int ui__help_window(const char *text);
 bool ui__dialog_yesno(const char *msg);