diff options
Diffstat (limited to 'src/gtimer.c')
| -rw-r--r-- | src/gtimer.c | 54 |
1 files changed, 35 insertions, 19 deletions
diff --git a/src/gtimer.c b/src/gtimer.c index 98556607..8956a190 100644 --- a/src/gtimer.c +++ b/src/gtimer.c @@ -36,14 +36,14 @@ #define GTIMER_FLG_JABBED 0x0004
#define GTIMER_FLG_SCHEDULED 0x0008
-#define TimeIsWithin(time, start, end) (end > start ? (time >= start && time <= end) : (time >= start || time <= end))
+/* Don't rework this macro to use a ternary operator - the gcc compiler stuffs it up */
+#define TimeIsWithin(x, start, end) ((end >= start && x >= start && x <= end) || (end < start && (x >= start || x <= end)))
// This mutex protects access to our tables
static MUTEX_DECL(mutex);
static Thread *pThread = 0;
static GTimer *pTimerHead = 0;
-static systime_t lastTime = 0;
-static SEMAPHORE_DECL(waitsem, 0);
+static BSEMAPHORE_DECL(waitsem, TRUE);
static WORKING_AREA(waTimerThread, GTIMER_THREAD_STACK_SIZE);
/*===========================================================================*/
@@ -55,7 +55,7 @@ static msg_t GTimerThreadHandler(void *arg) { GTimer *pt;
systime_t tm;
systime_t nxtTimeout;
- systime_t tmptime;
+ systime_t lastTime;
GTimerFunction fn;
void *param;
@@ -64,9 +64,11 @@ static msg_t GTimerThreadHandler(void *arg) { #endif
nxtTimeout = TIME_INFINITE;
+ lastTime = 0;
while(1) {
/* Wait for work to do. */
- chSemWaitTimeout(&waitsem, nxtTimeout);
+ chThdYield(); // Give someone else a go no matter how busy we are
+ chBSemWaitTimeout(&waitsem, nxtTimeout);
restartTimerChecks:
@@ -87,11 +89,13 @@ static msg_t GTimerThreadHandler(void *arg) { if ((pt->flags & GTIMER_FLG_PERIODIC) && pt->period != TIME_IMMEDIATE) {
// Yes - Update ready for the next period
if (!(pt->flags & GTIMER_FLG_INFINITE)) {
- do {
- pt->when += pt->period; // We may have skipped a period
- } while (TimeIsWithin(pt->when, lastTime, tm));
+ // We may have skipped a period.
+ // We use this complicated formulae rather than a loop
+ // because the gcc compiler stuffs up the loop so that it
+ // either loops forever or doesn't get executed at all.
+ pt->when += ((tm + pt->period - pt->when) / pt->period) * pt->period;
}
-
+
// We are definitely no longer jabbed
pt->flags &= ~GTIMER_FLG_JABBED;
@@ -120,10 +124,8 @@ static msg_t GTimerThreadHandler(void *arg) { }
// Find when we next need to wake up
- if (!(pt->flags & GTIMER_FLG_INFINITE)) {
- tmptime = pt->when - tm;
- if (tmptime < nxtTimeout) nxtTimeout = tmptime;
- }
+ if (!(pt->flags & GTIMER_FLG_INFINITE) && pt->when - tm < nxtTimeout)
+ nxtTimeout = pt->when - tm;
pt = pt->next;
} while(pt != pTimerHead);
}
@@ -201,11 +203,13 @@ void gtimerStart(GTimer *pt, GTimerFunction fn, void *param, bool_t periodic, sy pt->flags = GTIMER_FLG_SCHEDULED;
if (periodic)
pt->flags |= GTIMER_FLG_PERIODIC;
- if (millisec != TIME_INFINITE) {
+ if (millisec == TIME_INFINITE) {
+ pt->flags |= GTIMER_FLG_INFINITE;
+ pt->period = TIME_INFINITE;
+ } else {
pt->period = MS2ST(millisec);
pt->when = chTimeNow() + pt->period;
- } else
- pt->flags |= GTIMER_FLG_INFINITE;
+ }
// Just pop it on the end of the queue
if (pTimerHead) {
@@ -217,7 +221,8 @@ void gtimerStart(GTimer *pt, GTimerFunction fn, void *param, bool_t periodic, sy pt->next = pt->prev = pTimerHead = pt;
// Bump the thread
- chSemSignal(&waitsem);
+ if (!(pt->flags & GTIMER_FLG_INFINITE))
+ chBSemSignal(&waitsem);
chMtxUnlock();
}
@@ -249,6 +254,17 @@ void gtimerStop(GTimer *pt) { }
/**
+ * @brief Test if a timer is currently active
+ *
+ * @param[in] pt Pointer to a GTimer structure
+ *
+ * @api
+ */
+bool_t gtimerIsActive(GTimer *pt) {
+ return (pt->flags & GTIMER_FLG_SCHEDULED) ? TRUE : FALSE;
+}
+
+/**
* @brief Jab a timer causing the current period to immediate expire
* @details The callback function will be called as soon as possible.
*
@@ -268,7 +284,7 @@ void gtimerJab(GTimer *pt) { pt->flags |= GTIMER_FLG_JABBED;
// Bump the thread
- chSemSignal(&waitsem);
+ chBSemSignal(&waitsem);
chMtxUnlock();
}
@@ -291,7 +307,7 @@ void gtimerJabI(GTimer *pt) { pt->flags |= GTIMER_FLG_JABBED;
// Bump the thread
- chSemSignalI(&waitsem);
+ chBSemSignalI(&waitsem);
}
#endif /* GFX_USE_GTIMER */
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