Various optimizations to the scheduler.

git-svn-id: svn://svn.code.sf.net/p/chibios/svn/trunk@378 35acf78f-673a-0410-8e92-d51de3d6d3f4

6 files changed, 37 insertions, 17 deletions

diff --git a/src/chlists.c b/src/chlists.c
index 3b173c94d..dcb3b0412 100644
--- a/src/chlists.c
+++ b/src/chlists.c
@@ -47,19 +47,19 @@ void prio_insert(Thread *tp, ThreadsQueue *tqp) {
 }

 

 /*

- * Inserts a Thread into a FIFO queue.

+ * Inserts a Thread into a queue.

  *

  * @param tp the pointer to the thread to be inserted in the list

  * @param tqp the pointer to the threads list header

  */

-void fifo_insert(Thread *tp, ThreadsQueue *tqp) {

+void queue_insert(Thread *tp, ThreadsQueue *tqp) {

 

   tp->p_prev = (tp->p_next = (Thread *)tqp)->p_prev;

   tp->p_prev->p_next = tqp->p_prev = tp;

 }

 

 /*

- * Removes the first-out Thread from a FIFO queue and returns it.

+ * Removes the first-out Thread from a queue and returns it.

  *

  * @param tqp the pointer to the threads list header

  * @return the removed thread pointer

@@ -72,6 +72,19 @@ Thread *fifo_remove(ThreadsQueue *tqp) {
 }

 

 /*

+ * Removes the last-out Thread from a queue and returns it.

+ *

+ * @param tqp the pointer to the threads list header

+ * @return the removed thread pointer

+ */

+Thread *lifo_remove(ThreadsQueue *tqp) {

+  Thread *tp = tqp->p_next;

+

+  (tqp->p_next = tp->p_next)->p_prev = (Thread *)tqp;

+  return tp;

+}

+

+/*

  * Removes a Thread from a FIFO list and returns it.

  *

  * @param tp the pointer to the thread to be removed from the list

diff --git a/src/chmsg.c b/src/chmsg.c
index bcc7117e2..03b7edd01 100644
--- a/src/chmsg.c
+++ b/src/chmsg.c
@@ -40,9 +40,9 @@ msg_t chMsgSend(Thread *tp, msg_t msg) {
   if (tp->p_flags & P_MSGBYPRIO)

     prio_insert(currp, &tp->p_msgqueue);

   else

-    fifo_insert(currp, &tp->p_msgqueue);

+    queue_insert(currp, &tp->p_msgqueue);

 #else

-  fifo_insert(currp, &tp->p_msgqueue);

+  queue_insert(currp, &tp->p_msgqueue);

 #endif

   currp->p_msg = msg;

   currp->p_wtthdp = tp;

@@ -79,9 +79,9 @@ msg_t chMsgSendWithEvent(Thread *tp, msg_t msg, EventSource *esp) {
   if (tp->p_flags & P_MSGBYPRIO)

     prio_insert(currp, &tp->p_msgqueue);

   else

-    fifo_insert(currp, &tp->p_msgqueue);

+    queue_insert(currp, &tp->p_msgqueue);

 #else

-  fifo_insert(currp, &tp->p_msgqueue);

+  queue_insert(currp, &tp->p_msgqueue);

 #endif

   chEvtBroadcastI(esp);

   currp->p_wtthdp = tp;

diff --git a/src/chschd.c b/src/chschd.c
index c97eea1e8..8b606cd1b 100644
--- a/src/chschd.c
+++ b/src/chschd.c
@@ -174,18 +174,17 @@ void chSchWakeupS(Thread *ntp, msg_t msg) {
  * Intended to be called if \p chSchRescRequired() evaluates to \p TRUE.
  */
 void chSchDoRescheduleI(void) {
-  /* put the running thread on the ready queue */
+
   Thread *otp = currp;
-  chSchReadyI(otp);
-  /* pick the first thread from the ready queue */
+  /* pick the first thread from the ready queue and makes it current */
   (currp = fifo_remove(&rlist.r_queue))->p_state = PRCURR;
+  chSchReadyI(otp);
 #ifdef CH_USE_ROUNDROBIN
   rlist.r_preempt = CH_TIME_QUANTUM;
 #endif
 #ifdef CH_USE_TRACE
   chDbgTrace(otp, currp);
 #endif
-  /* switch thread context */
   chSysSwitchI(otp, currp);
 }
 
diff --git a/src/chsem.c b/src/chsem.c
index d1199f072..b5c197b6b 100644
--- a/src/chsem.c
+++ b/src/chsem.c
@@ -72,7 +72,7 @@ void chSemResetI(Semaphore *sp, cnt_t n) {
   cnt = sp->s_cnt;

   sp->s_cnt = n;

   while (cnt++ < 0)

-    chSchReadyI(fifo_remove(&sp->s_queue))->p_rdymsg = RDY_RESET;

+    chSchReadyI(lifo_remove(&sp->s_queue))->p_rdymsg = RDY_RESET;

 }

 

 /**

@@ -101,7 +101,7 @@ msg_t chSemWait(Semaphore *sp) {
 msg_t chSemWaitS(Semaphore *sp) {

 

   if (--sp->s_cnt < 0) {

-    fifo_insert(currp, &sp->s_queue);

+    queue_insert(currp, &sp->s_queue);

     currp->p_wtsemp = sp;

     chSchGoSleepS(PRWTSEM);

     return currp->p_rdymsg;

@@ -140,7 +140,7 @@ msg_t chSemWaitTimeout(Semaphore *sp, systime_t time) {
 msg_t chSemWaitTimeoutS(Semaphore *sp, systime_t time) {

 

   if (--sp->s_cnt < 0) {

-    fifo_insert(currp, &sp->s_queue);

+    queue_insert(currp, &sp->s_queue);

     currp->p_wtsemp = sp;

     return chSchGoSleepTimeoutS(PRWTSEM, time);

   }

@@ -201,7 +201,7 @@ msg_t chSemSignalWait(Semaphore *sps, Semaphore *spw) {
     chSchReadyI(fifo_remove(&sps->s_queue))->p_rdymsg = RDY_OK;

 

   if (--spw->s_cnt < 0) {

-    fifo_insert(currp, &spw->s_queue);

+    queue_insert(currp, &spw->s_queue);

     currp->p_wtsemp = spw;

     chSchGoSleepS(PRWTSEM);

     msg = currp->p_rdymsg;

diff --git a/src/include/inline.h b/src/include/inline.h
index 85de20f3f..9cc18974d 100644
--- a/src/include/inline.h
+++ b/src/include/inline.h
@@ -36,7 +36,7 @@ static INLINE void prio_insert(Thread *tp, ThreadsQueue *tqp) {
   tp->p_prev->p_next = cp->p_prev = tp;

 }

 

-static INLINE void fifo_insert(Thread *tp, ThreadsQueue *tqp) {

+static INLINE void queue_insert(Thread *tp, ThreadsQueue *tqp) {

 

   tp->p_prev = (tp->p_next = (Thread *)tqp)->p_prev;

   tp->p_prev->p_next = tqp->p_prev = tp;

@@ -49,6 +49,13 @@ static INLINE Thread *fifo_remove(ThreadsQueue *tqp) {
   return tp;

 }

 

+static INLINE Thread *lifo_remove(ThreadsQueue *tqp) {

+  Thread *tp = tqp->p_prev;

+

+  (tqp->p_prev = tp->p_prev)->p_next = (Thread *)tqp;

+  return tp;

+}

+

 static INLINE Thread *dequeue(Thread *tp) {

 

   tp->p_prev->p_next = tp->p_next;

diff --git a/src/include/lists.h b/src/include/lists.h
index d98892600..741648a03 100644
--- a/src/include/lists.h
+++ b/src/include/lists.h
@@ -61,8 +61,9 @@ typedef struct {
 extern "C" {

 #endif

   void prio_insert(Thread *tp, ThreadsQueue *tqp);

-  void fifo_insert(Thread *tp, ThreadsQueue *tqp);

+  void queue_insert(Thread *tp, ThreadsQueue *tqp);

   Thread *fifo_remove(ThreadsQueue *tqp);

+  Thread *lifo_remove(ThreadsQueue *tqp);

   Thread *dequeue(Thread *tp);

   void list_insert(Thread *tp, ThreadsList *tlp);

   Thread *list_remove(ThreadsList *tlp);