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/*
Copyright (C) 2004 John Orlando
AVRcam: a small real-time image processing engine.
This program 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 2 of the License, or (at your option) any later version.
This program 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, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
For more information on the AVRcam, please contact:
john@jrobot.net
or go to www.jrobot.net for more details regarding the system.
*/
/***********************************************************
Module Name: Executive.c
Module Date: 04/12/2004
Module Auth: John Orlando
Description: This file is responsible for implementing a
minimalist event dispatcher. It keeps track of an event
fifo that waits for new events to come in, and dispatches
them to any entities that care about them.
Revision History:
Date Rel Ver. Notes
4/10/2004 0.1 Module created
6/30/2004 1.0 Initial release for Circuit Cellar
contest.
1/16/2005 1.4 Fixed issue where the interrupts weren't
being turned off when the fastEventBitmask
was being accessed. Also removed redundant
interrupt masking when accessing the
main event fifo. Also fixed issue where
the main event fifo wasn't being checked
for events if an event was pending in
the fast event fifo.
***********************************************************/
/* Includes */
#include <stdlib.h>
#include "CommonDefs.h"
#include "Executive.h"
#include "FrameMgr.h"
#include "CamInterface.h"
#include "UIMgr.h"
#include "UartInterface.h"
#include "CamConfig.h"
#include "Utility.h"
/* Local Variables */
unsigned char Exec_eventFifo[EXEC_EVENT_FIFO_SIZE];
unsigned char Exec_eventFifoHead=0;
unsigned char Exec_eventFifoTail=0;
/* Local Function Definitions */
static unsigned char Exec_readEventFifo(void);
/* Local Structures and Typedefs */
/* Extern Variables */
/* This bitmask holds events that need to be processed as fast as possible */
unsigned char fastEventBitmask = 0x00;
/* Definitions */
#define IS_DATA_IN_EVENT_FIFO() (!(Exec_eventFifoHead == Exec_eventFifoTail))
/***********************************************************
Function Name: Exec_run
Function Description: This function is responsible for
running the main control loop. The control loop is
based on checking both the fast-event bitmask (for high
priority events) and the event FIFO to determine if an
event needs to be handled. The event is then dispatched
to the appropriate handler.
Inputs: none
Outputs: none
***********************************************************/
void Exec_run(void)
{
unsigned char eventGenerated;
while(1)
{
if (fastEventBitmask)
{
/* an event needing fast processing has been received */
/* a received line needs to be processed...this
needs to be processed as quickly as possible */
if (fastEventBitmask & FEV_ACQUIRE_LINE_COMPLETE)
{
DISABLE_INTS();
fastEventBitmask &= ~FEV_ACQUIRE_LINE_COMPLETE;
ENABLE_INTS();
FrameMgr_processLine();
/* also check if serial data needs to be sent
out through UIMgr */
UIMgr_transmitPendingData();
/* we can't just call acquire line again here,
since we don't know if we need to acquire another
line or not (it depends on the FrameMgr to figure
this out) */
}
if (fastEventBitmask & FEV_PROCESS_LINE_COMPLETE)
{
DISABLE_INTS();
fastEventBitmask &= ~FEV_PROCESS_LINE_COMPLETE;
ENABLE_INTS();
FrameMgr_acquireLine();
}
}
if (IS_DATA_IN_EVENT_FIFO() == TRUE)
{
eventGenerated = Exec_readEventFifo();
switch(eventGenerated)
{
case (EV_DUMP_FRAME):
FrameMgr_dispatchEvent(eventGenerated);
break;
case (EV_ENABLE_TRACKING):
FrameMgr_dispatchEvent(eventGenerated);
break;
case (EV_DISABLE_TRACKING):
FrameMgr_dispatchEvent(eventGenerated);
break;
case (EV_ACQUIRE_LINE_COMPLETE):
FrameMgr_dispatchEvent(eventGenerated);
UIMgr_dispatchEvent(eventGenerated);
break;
case (EV_ACQUIRE_FRAME_COMPLETE):
FrameMgr_dispatchEvent(eventGenerated);
break;
case (EV_PROCESS_LINE_COMPLETE):
FrameMgr_dispatchEvent(eventGenerated);
break;
case (EV_PROCESS_FRAME_COMPLETE):
FrameMgr_dispatchEvent(eventGenerated);
break;
case (EV_SERIAL_DATA_RECEIVED):
UIMgr_dispatchEvent(eventGenerated);
FrameMgr_dispatchEvent(eventGenerated);
break;
case (EV_SERIAL_DATA_PENDING_TX):
UIMgr_dispatchEvent(eventGenerated);
break;
default:
break;
}
}
/* toggle the debug line */
}
}
/***********************************************************
Function Name: Exec_readEventFifo
Function Description: This function is responsible for
reading a single event out of the event fifo.
Inputs: none
Outputs: unsigned char-the data read
***********************************************************/
static unsigned char Exec_readEventFifo(void)
{
unsigned char dataByte, tmpTail;
DISABLE_INTS();
/* just return the current tail from the tx fifo */
dataByte = Exec_eventFifo[Exec_eventFifoTail];
tmpTail = (Exec_eventFifoTail+1) & (EXEC_EVENT_FIFO_MASK);
Exec_eventFifoTail = tmpTail;
ENABLE_INTS();
return(dataByte);
}
/***********************************************************
Function Name: Exec_writeEventFifo
Function Description: This function is responsible for
writing a single event to the event fifo and
updating the appropriate pointers.
Inputs: data - the byte to write to the Fifo
Outputs: none
***********************************************************/
void Exec_writeEventFifo(unsigned char event)
{
unsigned char tmpHead;
DISABLE_INTS();
Exec_eventFifo[Exec_eventFifoHead] = event;
/* now move the head up */
tmpHead = (Exec_eventFifoHead + 1) & (EXEC_EVENT_FIFO_MASK);
Exec_eventFifoHead = tmpHead;
ENABLE_INTS();
}