diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/chmtx.c | 11 | ||||
| -rw-r--r-- | src/chschd.c | 12 |
2 files changed, 20 insertions, 3 deletions
diff --git a/src/chmtx.c b/src/chmtx.c index 6f53a615f..822789270 100644 --- a/src/chmtx.c +++ b/src/chmtx.c @@ -189,8 +189,15 @@ void chMtxUnlockS(void) { newprio = mp->m_queue.p_next->p_prio;
mp = mp->m_next;
}
- currp->p_prio = newprio;
- chSchWakeupS(tp, RDY_OK);
+ if (currp->p_prio == newprio)
+ chSchWakeupS(tp, RDY_OK);
+ else {
+ /* Note, changing priority and use chSchWakeupS() is wrong because the
+ internal optimization, see the chSchWakeupS() notes.*/
+ currp->p_prio = newprio;
+ chSchReadyI(tp, RDY_OK);
+ chSchRescheduleS();
+ }
}
}
diff --git a/src/chschd.c b/src/chschd.c index e091bb0a0..78efa57f7 100644 --- a/src/chschd.c +++ b/src/chschd.c @@ -104,6 +104,8 @@ void chSchGoSleepS(t_tstate newstate) { * @note The function is not meant to be used in the user code directly.
* @note It is equivalent to a \p chSchReadyI() followed by a
* \p chSchRescheduleS() but much more efficient.
+ * @note The function assumes that the invoking thread is the highest priority
+ * thread, so you can't use it to change priority and reschedule.
*/
void chSchWakeupS(Thread *ntp, t_msg msg) {
@@ -111,7 +113,15 @@ void chSchWakeupS(Thread *ntp, t_msg msg) { chSchReadyI(ntp, msg);
else {
Thread *otp = currp;
- chSchReadyI(otp, RDY_OK);
+ /* Optimization, assumes that the invoking thread has the highest priority
+ which is always true unless the priority was willingly changed.
+ This assumption allows us to place the thread always on top of the
+ ready list without have to scan it, free lunch.*/
+/* chSchReadyI(otp, RDY_OK);*/
+ otp->p_state = PRREADY;
+ otp->p_rdymsg = RDY_OK;
+ otp->p_next = (otp->p_prev = (Thread *)&rlist.r_queue)->p_next;
+ otp->p_next->p_prev = rlist.r_queue.p_next = otp;
(currp = ntp)->p_state = PRCURR;
ntp->p_rdymsg = msg;
rlist.r_preempt = CH_TIME_QUANTUM;
|