Re: [AD] X11 unresponsiveness and vsync

[Chris <kcat@xxxxxxxxxx>]

Okay, you can pretty much forget about the previous patch I posted. I 
thought of another solution. Basically what it does is.. everytime an 
input update call is blocked, it increments a variable, and when XUNLOCK 
actually unlocks, it forces an input update for each time missed.

I also noticed a small problem with _xwin_vsync. It does the flush 
buffer thing durring a lock and when it finishes, it reads the 
refresh_count var and waits for the next tic. Shouldn't it read the 
refresh_count var before flushing the buffer in case it tics while 
flushing? That'd be a nice spot for slow down to occur.

I attached patches for both src/x/xwin.c and 
include/allegro/platform/aintunix.h

- Kitty Cat

--- xwin.c	2004-07-11 03:33:10.000000000 -0700
+++ xwin.c	2004-07-12 17:23:50.000000000 -0700
@@ -139,6 +139,10 @@
    NULL         /* window close hook */
 };
 
+#ifndef ALLEGRO_MULTITHREADED
+int _xwin_missed_input;
+#endif
+
 void *allegro_icon = alex_xpm;
 
 int _xwin_last_line = -1;
@@ -2092,13 +2096,13 @@
 
 void _xwin_vsync(void)
 {
+   int prev = retrace_count;
+
    XLOCK();
    _xwin_private_vsync();
    XUNLOCK();
 
    if (_timer_installed) {
-      int prev = retrace_count;
-
       do {
       } while (retrace_count == prev);
    }
@@ -2434,7 +2438,12 @@
 
 void _xwin_handle_input(void)
 {
-   if (_xwin.lock_count) return;
+#ifndef ALLEGRO_MULTITHREADED
+   if (_xwin.lock_count) {
+      ++_xwin_missed_input;
+      return;
+   }
+#endif
 
    XLOCK();
 

--- aintunix.h	2003-02-07 05:29:06.000000000 -0800
+++ aintunix.h	2004-07-12 17:41:27.000000000 -0700
@@ -94,6 +94,10 @@
          _xwin.lock_count++;                    \
       } while (0)
 
+
+#ifndef ALLEGRO_MULTITHREADED
+
+   AL_VAR(int, _xwin_missed_input);
    #define XUNLOCK()                            \
       do {                                      \
          if (_unix_bg_man->multi_threaded) {    \
@@ -101,8 +105,27 @@
                XUnlockDisplay(_xwin.display);   \
          }                                      \
          _xwin.lock_count--;                    \
+         if (_xwin.lock_count == 0) {           \
+            while(_xwin_missed_input) {         \
+               _xwin_handle_input();            \
+               --xwin_missed_input;             \
+            }                                   \
+         }                                      \
       } while (0)
 
+#else
+
+   #define XUNLOCK()                            \
+      do {                                      \
+         if (_unix_bg_man->multi_threaded) {    \
+            if (_xwin.display)                  \
+               XUnlockDisplay(_xwin.display);   \
+         }                                      \
+         _xwin.lock_count--;                    \
+      } while (0)
+
+#endif
+
 #endif