From 2eefb5acb847eeb2d10bac860d37c4cef00be67b Mon Sep 17 00:00:00 2001
From: Miika Pekkarinen <miipekk@ihme.org>
Date: Sun, 11 Mar 2007 10:52:36 +0000
Subject: Optimized the gui list code performance, including automatic frame
 dropping and cpu boosting when button events are getting queued. Improved
 scrollwheel acceleration code is needed to notice a real change.

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@12721 a1c6a512-1295-4272-9138-f99709370657
---
 firmware/drivers/button.c | 36 ++++++++++++++++++++++++++++++++++--
 firmware/export/kernel.h  |  1 +
 firmware/kernel.c         | 21 +++++++++++++++++++++
 3 files changed, 56 insertions(+), 2 deletions(-)

(limited to 'firmware')

diff --git a/firmware/drivers/button.c b/firmware/drivers/button.c
index a1fd58c447..7c5858a1e3 100644
--- a/firmware/drivers/button.c
+++ b/firmware/drivers/button.c
@@ -26,6 +26,7 @@
 #include "system.h"
 #include "button.h"
 #include "kernel.h"
+#include "thread.h"
 #include "backlight.h"
 #include "serial.h"
 #include "power.h"
@@ -255,21 +256,52 @@ static void button_tick(void)
     lastbtn = btn & ~(BUTTON_REL | BUTTON_REPEAT);
 }
 
+void button_boost(bool state)
+{
+    static bool boosted = false;
+    
+    if (state && !boosted)
+    {
+        cpu_boost(true);
+        boosted = true;
+    }
+    else if (!state && boosted)
+    {
+        cpu_boost(false);
+        boosted = false;
+    }
+}
+
 long button_get(bool block)
 {
     struct event ev;
-
-    if ( block || !queue_empty(&button_queue) )
+    int pending_count = queue_count(&button_queue);
+    
+    /* Control the CPU boost trying to keep queue empty. */
+    if (pending_count == 0)
+        button_boost(false);
+    else if (pending_count > 2)
+        button_boost(true);
+    
+    if ( block || pending_count )
     {
         queue_wait(&button_queue, &ev);
         return ev.id;
     }
+    
     return BUTTON_NONE;
 }
 
 long button_get_w_tmo(int ticks)
 {
     struct event ev;
+    
+    /* Be sure to keep boosted state. */
+    if (!queue_empty(&button_queue))
+        return button_get(true);
+    
+    button_boost(false);
+    
     queue_wait_w_tmo(&button_queue, &ev, ticks);
     return (ev.id != SYS_TIMEOUT)? ev.id: BUTTON_NONE;
 }
diff --git a/firmware/export/kernel.h b/firmware/export/kernel.h
index cd6a810bad..13e353d736 100644
--- a/firmware/export/kernel.h
+++ b/firmware/export/kernel.h
@@ -123,6 +123,7 @@ extern bool queue_in_queue_send(struct event_queue *q);
 extern bool queue_empty(const struct event_queue* q);
 extern void queue_clear(struct event_queue* q);
 extern void queue_remove_from_head(struct event_queue *q, long id);
+extern int queue_count(const struct event_queue *q);
 extern int queue_broadcast(long id, intptr_t data);
 
 extern void mutex_init(struct mutex *m);
diff --git a/firmware/kernel.c b/firmware/kernel.c
index db7249fdee..c304e455c2 100644
--- a/firmware/kernel.c
+++ b/firmware/kernel.c
@@ -374,6 +374,27 @@ void queue_remove_from_head(struct event_queue *q, long id)
     set_irq_level(oldlevel);
 }
 
+/**
+ * The number of events waiting in the queue.
+ * 
+ * @param struct of event_queue
+ * @return number of events in the queue
+ */
+int queue_count(const struct event_queue *q)
+{
+    int oldlevel = set_irq_level(HIGHEST_IRQ_LEVEL);
+    int result = 0;
+    
+    if (q->read <= q->write)
+        result = q->write - q->read;
+    else
+        result = QUEUE_LENGTH - (q->read - q->write);
+    
+    set_irq_level(oldlevel);
+    
+    return result;
+}
+
 int queue_broadcast(long id, intptr_t data)
 {
    int i;
-- 
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