From 06a4a3cdcccc56970f507f617667b9034b2975b0 Mon Sep 17 00:00:00 2001 From: Jason McCarver Date: Fri, 14 Sep 2012 10:02:51 +0100 Subject: xentop.c: Change curses painting behavior to avoid flicker Currently, xentop calls clear() before drawing the screen and calling refresh(). This causes the entire screen to be repainted from scratch on each call to refresh(). It is inefficient and causes visible flicker when using xentop. This patch fixes this by calling erase() instead of clear() which overwrites the current screen with blanks instead. The screen is then drawn as usual in the top() function and refresh() is called. This method allows curses to only repaint the characters that have changed since the last call to refresh(), thus avoiding the flicker and sending fewer characters to the terminal. In the event the screen becomes corrupted, this patch accepts a CTRL-L keystroke from the user which will call clear() and force a repaint of the entire screen. Signed-off-by: Jason McCarver Acked-by: Ian Jackson Committed-by: Ian Campbell --- tools/xenstat/xentop/xentop.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) (limited to 'tools/xenstat') diff --git a/tools/xenstat/xentop/xentop.c b/tools/xenstat/xentop/xentop.c index db9990f50b..dd11927dc2 100644 --- a/tools/xenstat/xentop/xentop.c +++ b/tools/xenstat/xentop/xentop.c @@ -57,6 +57,7 @@ #endif #define KEY_ESCAPE '\x1B' +#define KEY_REPAINT '\x0C' #ifdef HOST_SunOS /* Old curses library on Solaris takes non-const strings. Also, ERR interferes @@ -383,6 +384,9 @@ static int handle_key(int ch) case 'd': case 'D': set_prompt("Delay(sec)", set_delay); break; + case KEY_REPAINT: + clear(); + break; case 'q': case 'Q': case KEY_ESCAPE: return 0; } @@ -1201,7 +1205,7 @@ int main(int argc, char **argv) do { gettimeofday(&curtime, NULL); if(ch != ERR || (curtime.tv_sec - oldtime.tv_sec) >= delay) { - clear(); + erase(); top(); oldtime = curtime; refresh(); -- cgit v1.2.3