[Qemu-devel] [PULL 2/2] sdl: shorten the GUI refresh interval when mouse or keyboard is active

[Gerd Hoffmann <kraxel@redhat.com>]

From: Jindřich Makovička <makovick@gmail.com>

Signed-off-by: Jindřich Makovička <makovick@gmail.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
---
 include/ui/sdl2.h |  1 +
 ui/sdl.c          | 22 ++++++++++++++++++++++
 ui/sdl2.c         | 23 +++++++++++++++++++++++
 3 files changed, 46 insertions(+)

diff --git a/include/ui/sdl2.h b/include/ui/sdl2.h
index b7ac38f..3f0b57b 100644
--- a/include/ui/sdl2.h
+++ b/include/ui/sdl2.h
@@ -19,6 +19,7 @@ struct sdl2_console {
     int hidden;
     int opengl;
     int updates;
+    int idle_counter;
     SDL_GLContext winctx;
 #ifdef CONFIG_OPENGL
     ConsoleGLState *gls;
diff --git a/ui/sdl.c b/ui/sdl.c
index c837436..f215fe1 100644
--- a/ui/sdl.c
+++ b/ui/sdl.c
@@ -60,6 +60,11 @@ static SDL_Cursor *guest_sprite = NULL;
 static SDL_PixelFormat host_format;
 static int scaling_active = 0;
 static Notifier mouse_mode_notifier;
+static int idle_counter;
+
+#define SDL_REFRESH_INTERVAL_BUSY 10
+#define SDL_MAX_IDLE_COUNT (2 * GUI_REFRESH_INTERVAL_DEFAULT \
+                            / SDL_REFRESH_INTERVAL_BUSY + 1)
 
 #if 0
 #define DEBUG_SDL
@@ -802,6 +807,7 @@ static void handle_activation(SDL_Event *ev)
 static void sdl_refresh(DisplayChangeListener *dcl)
 {
     SDL_Event ev1, *ev = &ev1;
+    int idle = 1;
 
     if (last_vm_running != runstate_is_running()) {
         last_vm_running = runstate_is_running();
@@ -817,9 +823,11 @@ static void sdl_refresh(DisplayChangeListener *dcl)
             sdl_update(dcl, 0, 0, real_screen->w, real_screen->h);
             break;
         case SDL_KEYDOWN:
+            idle = 0;
             handle_keydown(ev);
             break;
         case SDL_KEYUP:
+            idle = 0;
             handle_keyup(ev);
             break;
         case SDL_QUIT:
@@ -829,10 +837,12 @@ static void sdl_refresh(DisplayChangeListener *dcl)
             }
             break;
         case SDL_MOUSEMOTION:
+            idle = 0;
             handle_mousemotion(ev);
             break;
         case SDL_MOUSEBUTTONDOWN:
         case SDL_MOUSEBUTTONUP:
+            idle = 0;
             handle_mousebutton(ev);
             break;
         case SDL_ACTIVEEVENT:
@@ -847,6 +857,18 @@ static void sdl_refresh(DisplayChangeListener *dcl)
             break;
         }
     }
+
+    if (idle) {
+        if (idle_counter < SDL_MAX_IDLE_COUNT) {
+            idle_counter++;
+            if (idle_counter >= SDL_MAX_IDLE_COUNT) {
+                dcl->update_interval = GUI_REFRESH_INTERVAL_DEFAULT;
+            }
+        }
+    } else {
+        idle_counter = 0;
+        dcl->update_interval = SDL_REFRESH_INTERVAL_BUSY;
+    }
 }
 
 static void sdl_mouse_warp(DisplayChangeListener *dcl,
diff --git a/ui/sdl2.c b/ui/sdl2.c
index 46270f4..c0a76d7 100644
--- a/ui/sdl2.c
+++ b/ui/sdl2.c
@@ -49,6 +49,10 @@ static int guest_x, guest_y;
 static SDL_Cursor *guest_sprite;
 static Notifier mouse_mode_notifier;
 
+#define SDL2_REFRESH_INTERVAL_BUSY 10
+#define SDL2_MAX_IDLE_COUNT (2 * GUI_REFRESH_INTERVAL_DEFAULT \
+                             / SDL2_REFRESH_INTERVAL_BUSY + 1)
+
 static void sdl_update_caption(struct sdl2_console *scon);
 
 static struct sdl2_console *get_scon_from_window(uint32_t window_id)
@@ -578,6 +582,7 @@ static void handle_windowevent(SDL_Event *ev)
 void sdl2_poll_events(struct sdl2_console *scon)
 {
     SDL_Event ev1, *ev = &ev1;
+    int idle = 1;
 
     if (scon->last_vm_running != runstate_is_running()) {
         scon->last_vm_running = runstate_is_running();
@@ -587,12 +592,15 @@ void sdl2_poll_events(struct sdl2_console *scon)
     while (SDL_PollEvent(ev)) {
         switch (ev->type) {
         case SDL_KEYDOWN:
+            idle = 0;
             handle_keydown(ev);
             break;
         case SDL_KEYUP:
+            idle = 0;
             handle_keyup(ev);
             break;
         case SDL_TEXTINPUT:
+            idle = 0;
             handle_textinput(ev);
             break;
         case SDL_QUIT:
@@ -602,13 +610,16 @@ void sdl2_poll_events(struct sdl2_console *scon)
             }
             break;
         case SDL_MOUSEMOTION:
+            idle = 0;
             handle_mousemotion(ev);
             break;
         case SDL_MOUSEBUTTONDOWN:
         case SDL_MOUSEBUTTONUP:
+            idle = 0;
             handle_mousebutton(ev);
             break;
         case SDL_MOUSEWHEEL:
+            idle = 0;
             handle_mousewheel(ev);
             break;
         case SDL_WINDOWEVENT:
@@ -618,6 +629,18 @@ void sdl2_poll_events(struct sdl2_console *scon)
             break;
         }
     }
+
+    if (idle) {
+        if (scon->idle_counter < SDL2_MAX_IDLE_COUNT) {
+            scon->idle_counter++;
+            if (scon->idle_counter >= SDL2_MAX_IDLE_COUNT) {
+                scon->dcl.update_interval = GUI_REFRESH_INTERVAL_DEFAULT;
+            }
+        }
+    } else {
+        scon->idle_counter = 0;
+        scon->dcl.update_interval = SDL2_REFRESH_INTERVAL_BUSY;
+    }
 }
 
 static void sdl_mouse_warp(DisplayChangeListener *dcl,
-- 
1.8.3.1