From a85044bf9eaa0a7206c1978d3cfd57ab2d7fae2f Mon Sep 17 00:00:00 2001
From: Miika Pekkarinen <miipekk@ihme.org>
Date: Sat, 16 Sep 2006 16:18:11 +0000
Subject: New scheduler, with priorities for swcodec platforms. Frequent task
 switching should be more efficient and tasks are stored in linked lists to
 eliminate unnecessary task switching to improve performance. Audio should no
 longer skip on swcodec targets caused by too CPU hungry UI thread or
 background threads.

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@10958 a1c6a512-1295-4272-9138-f99709370657
---
 firmware/kernel.c | 65 ++++++++++++++++++++++++++-----------------------------
 1 file changed, 31 insertions(+), 34 deletions(-)

(limited to 'firmware/kernel.c')

diff --git a/firmware/kernel.c b/firmware/kernel.c
index 889f950252..4a6d61515a 100644
--- a/firmware/kernel.c
+++ b/firmware/kernel.c
@@ -35,7 +35,6 @@ static void (*tick_funcs[MAX_NUM_TICK_TASKS])(void);
 static struct event_queue *all_queues[32];
 static int num_queues;
 
-void sleep(int ticks) ICODE_ATTR;
 void queue_wait(struct event_queue *q, struct event *ev) ICODE_ATTR;
 
 /****************************************************************************
@@ -71,13 +70,7 @@ void sleep(int ticks)
     } while(counter > 0);
 
 #else
-    /* Always sleep at least 1 tick */
-    int timeout = current_tick + ticks + 1;
-
-    while (TIME_BEFORE( current_tick, timeout )) {
-        sleep_thread();
-    }
-    wake_up_thread();
+    sleep_thread(ticks);
 #endif
 }
 
@@ -86,21 +79,24 @@ void yield(void)
 #if (CONFIG_CPU == S3C2440 || defined(ELIO_TPJ1022) && defined(BOOTLOADER))
     /* Some targets don't like yielding in the bootloader */
 #else
-    switch_thread();
-    wake_up_thread();
+    switch_thread(true, NULL);
 #endif
 }
 
 /****************************************************************************
  * Queue handling stuff
  ****************************************************************************/
-void queue_init(struct event_queue *q)
+void queue_init(struct event_queue *q, bool register_queue)
 {
     q->read = 0;
     q->write = 0;
-
-    /* Add it to the all_queues array */
-    all_queues[num_queues++] = q;
+    q->thread = NULL;
+    
+    if (register_queue)
+    {
+        /* Add it to the all_queues array */
+        all_queues[num_queues++] = q;
+    }
 }
 
 void queue_delete(struct event_queue *q)
@@ -108,6 +104,8 @@ void queue_delete(struct event_queue *q)
     int i;
     bool found = false;
 
+    wakeup_thread(&q->thread);
+    
     /* Find the queue to be deleted */
     for(i = 0;i < num_queues;i++)
     {
@@ -132,26 +130,22 @@ void queue_delete(struct event_queue *q)
 
 void queue_wait(struct event_queue *q, struct event *ev)
 {
-    while(q->read == q->write)
+    if (q->read == q->write)
     {
-        sleep_thread();
+        block_thread(&q->thread, 0);
     }
-    wake_up_thread();
 
     *ev = q->events[(q->read++) & QUEUE_LENGTH_MASK];
 }
 
 void queue_wait_w_tmo(struct event_queue *q, struct event *ev, int ticks)
 {
-    unsigned int timeout = current_tick + ticks;
-
-    while(q->read == q->write && TIME_BEFORE( current_tick, timeout ))
+    if (q->read == q->write && ticks > 0)
     {
-        sleep_thread();
+        block_thread(&q->thread, ticks);
     }
-    wake_up_thread();
 
-    if(q->read != q->write)
+    if (q->read != q->write)
     {
         *ev = q->events[(q->read++) & QUEUE_LENGTH_MASK];
     }
@@ -171,6 +165,9 @@ void queue_post(struct event_queue *q, long id, void *data)
 
     q->events[wr].id = id;
     q->events[wr].data = data;
+    
+    wakeup_thread(&q->thread);
+    
     set_irq_level(oldlevel);
 }
 
@@ -250,7 +247,6 @@ void IMIA0(void)
     }
 
     current_tick++;
-    wake_up_thread();
 
     TSR0 &= ~0x01;
 }
@@ -301,7 +297,6 @@ void TIMER0(void)
     }
 
     current_tick++;
-    wake_up_thread();
 
     TER0 = 0xff; /* Clear all events */
 }
@@ -330,7 +325,6 @@ void TIMER0(void)
     }
 
     current_tick++;
-    wake_up_thread();
 
     /* re-enable timer by clearing the counter */
     TACON |= 0x80;
@@ -382,7 +376,6 @@ void TIMER1(void)
     }
 
     current_tick++;
-    wake_up_thread();
 }
 #endif
 
@@ -415,7 +408,6 @@ void timer_handler(void)
     }
 
     current_tick++;
-    wake_up_thread();
 
     TIMERR0C = 1;
 }
@@ -513,22 +505,27 @@ int tick_remove_task(void (*f)(void))
 void mutex_init(struct mutex *m)
 {
     m->locked = false;
+    m->thread = NULL;
 }
 
 void mutex_lock(struct mutex *m)
 {
-    /* Wait until the lock is open... */
-    while(m->locked)
-        sleep_thread();
-    wake_up_thread();
-
+    if (m->locked)
+    {
+        /* Wait until the lock is open... */
+        block_thread(&m->thread, 0);
+    }
+    
     /* ...and lock it */
     m->locked = true;
 }
 
 void mutex_unlock(struct mutex *m)
 {
-    m->locked = false;
+    if (m->thread == NULL)
+        m->locked = false;
+    else
+        wakeup_thread(&m->thread);
 }
 
 #endif
-- 
cgit v1.2.3