GEVENT, GTIMER & GINPUT subsystems

GEVENT - for passing event structures from Sources to Listeners
GTIMER - thread context based once-off and periodic timers.
GINPUT - extensible, multiple device-type, input sub-system.
gevent & gtimer are code complete, ginput is definition complete but not
code complete.

1 files changed, 302 insertions, 0 deletions

diff --git a/src/gtimer.c b/src/gtimer.c
new file mode 100644
index 00000000..84518a23
--- /dev/null
+++ b/src/gtimer.c
@@ -0,0 +1,302 @@
+/*

+    ChibiOS/GFX - Copyright (C) 2012

+                 Joel Bodenmann aka Tectu <joel@unormal.org>

+

+    This file is part of ChibiOS/GFX.

+

+    ChibiOS/GFX is free software; you can redistribute it and/or modify

+    it under the terms of the GNU General Public License as published by

+    the Free Software Foundation; either version 3 of the License, or

+    (at your option) any later version.

+

+    ChibiOS/GFX is distributed in the hope that it will be useful,

+    but WITHOUT ANY WARRANTY; without even the implied warranty of

+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

+    GNU General Public License for more details.

+

+    You should have received a copy of the GNU General Public License

+    along with this program.  If not, see <http://www.gnu.org/licenses/>.

+*/

+

+/**

+ * @file    src/gtimer.c

+ * @brief   GTIMER Driver code.

+ *

+ * @addtogroup GTIMER

+ * @{

+ */

+#include "ch.h"

+#include "hal.h"

+#include "gtimer.h"

+

+#ifndef _GTIMER_C

+#define _GTIMER_C

+

+#if GFX_USE_GTIMER || defined(__DOXYGEN__)

+

+#define GTIMER_FLG_PERIODIC		0x0001

+#define GTIMER_FLG_INFINITE		0x0002

+#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))

+

+// 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 WORKING_AREA(waTimerThread, GTIMER_THREAD_STACK_SIZE);

+

+/*===========================================================================*/

+/* Driver local functions.                                                   */

+/*===========================================================================*/

+

+static msg_t GTimerThreadHandler(void *arg) {

+	(void)arg;

+	GTimer			*pt;

+	systime_t		tm;

+	systime_t		nxtTimeout;

+	systime_t		tmptime;

+	GTimerFunction	fn;

+	void			*param;

+

+	#if CH_USE_REGISTRY

+		chRegSetThreadName("GTimer");

+	#endif

+

+	nxtTimeout = TIME_INFINITE;

+	while(1) {

+		/* Wait for work to do. */

+		chSemWaitTimeout(&waitsem, nxtTimeout);

+		

+	restartTimerChecks:

+	

+		// Our reference time

+		tm = chTimeNow();

+		nxtTimeout = TIME_INFINITE;

+		

+		/* We need to obtain the mutex */

+		chMtxLock(&mutex);

+

+		if (pTimerHead) {

+			pt = pTimerHead;

+			do {

+				// Do we have something to do for this timer?

+				if ((pt->flags & GTIMER_FLG_JABBED) || (!(pt->flags & GTIMER_FLG_INFINITE) && TimeIsWithin(pt->when, lastTime, tm))) {

+				

+					// Is this timer periodic?

+					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 are definitely no longer jabbed

+						pt->flags &= ~GTIMER_FLG_JABBED;

+						

+					} else {

+						// No - get us off the timers list

+						if (pt->next == pt->prev)

+							pTimerHead = 0;

+						else {

+							pt->next->prev = pt->prev;

+							pt->prev->next = pt->next;

+							if (pTimerHead == pt)

+								pTimerHead = pt->next;

+						}

+						pt->flags = 0;

+					}

+					

+					// Call the callback function

+					fn = pt->fn;

+					param = pt->param;

+					chMtxUnlock();

+					fn(param);

+					

+					// We no longer hold the mutex, the callback function may have taken a while

+					// and our list may have been altered so start again!

+					goto restartTimerChecks;

+				}

+				

+				// Find when we next need to wake up

+				if (!(pt->flags & GTIMER_FLG_INFINITE)) {

+					tmptime = pt->when - tm;

+					if (tmptime < nxtTimeout) nxtTimeout = tmptime;

+				}

+				pt = pt->next;

+			} while(pt != pTimerHead);

+		}

+

+		// Ready for the next loop

+		lastTime = tm;

+		chMtxUnlock();

+	}

+	return 0;

+}

+

+/**

+ * @brief   Initialise a timer.

+ *

+ * @param[in] pt 	pointer to a GTimer structure

+ *

+ * @api

+ */

+void gtimerInit(GTimer *pt) {

+	pt->flags = 0;

+}

+

+/**

+ * @brief   Set a timer going or alter its properties if it is already going.

+ *

+ * @param[in] pt	Pointer to a GTimer structure

+ * @param[in] fn		The callback function

+ * @param[in] param		The parameter to pass to the callback function

+ * @param[in] periodic	Is the timer a periodic timer? FALSE is a once-only timer.

+ * @param[in] millisec	The timer period. The following special values are allowed:

+ *							TIME_IMMEDIATE	causes the callback function to be called asap.

+ *											A periodic timer with this value will fire once only.

+ *							TIME_INFINITE	never timeout (unless triggered by gtimerJab or gtimerJabI)

+ *

+ * @note				If the timer is already active its properties are updated with the new parameters.

+ *						The current period will be immediately canceled (without the callback function being

+ *						called) and the timer will be restart with the new timer properties.

+ * @note				The callback function should be careful not to over-run the thread stack.

+ *						Define a new value for the macro GTIME_THREAD_STACK_SIZE if you want to

+ *						change the default size.

+ * @note				The callback function should return as quickly as possible as all

+ *						timer callbacks are performed by a single thread. If a callback function

+ *						takes too long it could affect the timer response for other timers.

+ * @note				A timer callback function is not a replacement for a dedicated thread if the

+ *						function wants to perform computationally expensive stuff.

+ * @note				As the callback function is called on GTIMER's thread, the function must make sure it uses

+ *						appropriate synchronisation controls such as semaphores or mutexes around any data

+ *						structures it shares with other threads such as the main application thread.

+ *

+ * @api

+ */

+void gtimerStart(GTimer *pt, GTimerFunction fn, void *param, bool_t periodic, systime_t millisec) {

+	chMtxLock(&mutex);

+	

+	// Start our thread if not already going

+	if (!pThread)

+		pThread = chThdCreateStatic(waTimerThread, sizeof(waTimerThread), HIGHPRIO, GTimerThreadHandler, NULL);

+

+	// Is this already scheduled?

+	if (pt->flags & GTIMER_FLG_SCHEDULED) {

+		// Cancel it!

+		if (pt->next == pt->prev)

+			pTimerHead = 0;

+		else {

+			pt->next->prev = pt->prev;

+			pt->prev->next = pt->next;

+			if (pTimerHead == pt)

+				pTimerHead = pt->next;

+		}

+	}

+	

+	// Set up the timer structure

+	pt->fn = fn;

+	pt->param = param;

+	pt->flags = GTIMER_FLG_SCHEDULED;

+	if (periodic)

+		pt->flags |= GTIMER_FLG_PERIODIC;

+	if (millisec != TIME_INFINITE) {

+		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) {

+		pt->next = pTimerHead;

+		pt->prev = pTimerHead->prev;

+		pt->prev->next = pt;

+		pt->next->prev = pt;

+	} else

+		pt->next = pt->prev = pTimerHead = pt;

+

+	// Bump the thread

+	chSemSignal(&waitsem);

+	chMtxUnlock();

+}

+

+/**

+ * @brief   Stop a timer (periodic or otherwise)

+ *

+ * @param[in] pt		Pointer to a GTimer structure

+ *

+ * @note				If the timer is not active this does nothing.

+ *

+ * @api

+ */

+void gtimerStop(GTimer *pt) {

+	chMtxLock(&mutex);

+	if (pt->flags & GTIMER_FLG_SCHEDULED) {

+		// Cancel it!

+		if (pt->next == pt->prev)

+			pTimerHead = 0;

+		else {

+			pt->next->prev = pt->prev;

+			pt->prev->next = pt->next;

+			if (pTimerHead == pt)

+				pTimerHead = pt->next;

+		}

+		// Make sure we know the structure is dead!

+		pt->flags = 0;

+	}

+	chMtxUnlock();

+}

+

+/**

+ * @brief   			Jab a timer causing the current period to immediate expire

+ * @details				The callback function will be called as soon as possible.

+ *

+ * @pre					Use from a normal thread context.

+ *

+ * @param[in] pt		Pointer to a GTimer structure

+ *

+ * @note				If the timer is not active this does nothing.

+ * @note				Repeated Jabs before the callback function actually happens are ignored.

+ *

+ * @api

+ */

+void gtimerJab(GTimer *pt) {

+	chMtxLock(&mutex);

+	

+	// Jab it!

+	pt->flags |= GTIMER_FLG_JABBED;

+

+	// Bump the thread

+	chSemSignal(&waitsem);

+	chMtxUnlock();

+}

+

+/**

+ * @brief   			Jab a timer causing the current period to immediate expire

+ * @details				The callback function will be called as soon as possible.

+ *

+ * @pre					Use from an interrupt routine context.

+ *

+ * @param[in] pt		Pointer to a GTimer structure

+ *

+ * @note				If the timer is not active this does nothing.

+ * @note				Repeated Jabs before the callback function actually happens are ignored.

+ *

+ * @api

+ */

+void gtimerJabI(GTimer *pt) {

+	// Jab it!

+	pt->flags |= GTIMER_FLG_JABBED;

+

+	// Bump the thread

+	chSemSignalI(&waitsem);

+}

+

+#endif /* GFX_USE_GTIMER */

+

+#endif /* _GTIMER_C */

+/** @} */