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29 * This demo application file demonstrates the use of queues to pass data
30 * between co-routines.
32 * N represents the number of 'fixed delay' co-routines that are created and
33 * is set during initialisation.
35 * N 'fixed delay' co-routines are created that just block for a fixed
36 * period then post the number of an LED onto a queue. Each such co-routine
37 * uses a different block period. A single 'flash' co-routine is also created
38 * that blocks on the same queue, waiting for the number of the next LED it
39 * should flash. Upon receiving a number it simply toggle the instructed LED
40 * then blocks on the queue once more. In this manner each LED from LED 0 to
41 * LED N-1 is caused to flash at a different rate.
43 * The 'fixed delay' co-routines are created with co-routine priority 0. The
44 * flash co-routine is created with co-routine priority 1. This means that
45 * the queue should never contain more than a single item. This is because
46 * posting to the queue will unblock the 'flash' co-routine, and as this has
47 * a priority greater than the tasks posting to the queue it is guaranteed to
48 * have emptied the queue and blocked once again before the queue can contain
49 * any more date. An error is indicated if an attempt to post data to the
50 * queue fails - indicating that the queue is already full.
54 /* Scheduler includes. */
59 /* Demo application includes. */
63 /* The queue should only need to be of length 1. See the description at the
65 #define crfQUEUE_LENGTH 1
67 #define crfFIXED_DELAY_PRIORITY 0
68 #define crfFLASH_PRIORITY 1
70 /* Only one flash co-routine is created so the index is not significant. */
71 #define crfFLASH_INDEX 0
73 /* Don't allow more than crfMAX_FLASH_TASKS 'fixed delay' co-routines to be
75 #define crfMAX_FLASH_TASKS 8
77 /* We don't want to block when posting to the queue. */
78 #define crfPOSTING_BLOCK_TIME 0
80 /* Added by MPi, this define is added in order to make the vParTestToggleLED()
81 work. This basically differentiates the PDR09 from PDR00. 7-seg display LEDs connected
82 to PDR09 (SEG1) are used by the prvFlashCoRoutine() and PDR00 (SEG2) are used by tasks. */
83 #define PDR00_Offset 8
86 * The 'fixed delay' co-routine as described at the top of the file.
88 static void prvFixedDelayCoRoutine( CoRoutineHandle_t xHandle, unsigned portBASE_TYPE uxIndex );
91 * The 'flash' co-routine as described at the top of the file.
93 static void prvFlashCoRoutine( CoRoutineHandle_t xHandle, unsigned portBASE_TYPE uxIndex );
95 /* The queue used to pass data between the 'fixed delay' co-routines and the
96 'flash' co-routine. */
97 static QueueHandle_t xFlashQueue;
99 /* This will be set to pdFALSE if we detect an error. */
100 static unsigned portBASE_TYPE uxCoRoutineFlashStatus = pdPASS;
102 /*-----------------------------------------------------------*/
105 * See the header file for details.
107 void vStartFlashCoRoutines( unsigned portBASE_TYPE uxNumberToCreate )
109 unsigned portBASE_TYPE uxIndex;
111 if( uxNumberToCreate > crfMAX_FLASH_TASKS )
113 uxNumberToCreate = crfMAX_FLASH_TASKS;
116 /* Create the queue used to pass data between the co-routines. */
117 xFlashQueue = xQueueCreate( crfQUEUE_LENGTH, sizeof( unsigned portBASE_TYPE ) );
121 /* Create uxNumberToCreate 'fixed delay' co-routines. */
122 for( uxIndex = 0; uxIndex < uxNumberToCreate; uxIndex++ )
124 xCoRoutineCreate( prvFixedDelayCoRoutine, crfFIXED_DELAY_PRIORITY, uxIndex );
127 /* Create the 'flash' co-routine. */
128 xCoRoutineCreate( prvFlashCoRoutine, crfFLASH_PRIORITY, crfFLASH_INDEX );
131 /*-----------------------------------------------------------*/
133 static void prvFixedDelayCoRoutine( CoRoutineHandle_t xHandle, unsigned portBASE_TYPE uxIndex )
135 /* Even though this is a co-routine the xResult variable does not need to be
136 static as we do not need it to maintain its state between blocks. */
137 signed portBASE_TYPE xResult;
138 /* The uxIndex parameter of the co-routine function is used as an index into
139 the xFlashRates array to obtain the delay period to use. */
140 static const TickType_t xFlashRates[ crfMAX_FLASH_TASKS ] = { 150 / portTICK_PERIOD_MS,
141 200 / portTICK_PERIOD_MS,
142 250 / portTICK_PERIOD_MS,
143 300 / portTICK_PERIOD_MS,
144 350 / portTICK_PERIOD_MS,
145 400 / portTICK_PERIOD_MS,
146 450 / portTICK_PERIOD_MS,
147 500 / portTICK_PERIOD_MS };
149 /* Co-routines MUST start with a call to crSTART. */
154 /* Post our uxIndex value onto the queue. This is used as the LED to
156 crQUEUE_SEND( xHandle, xFlashQueue, ( void * ) &uxIndex, crfPOSTING_BLOCK_TIME, &xResult );
158 if( xResult != pdPASS )
160 /* For the reasons stated at the top of the file we should always
161 find that we can post to the queue. If we could not then an error
163 uxCoRoutineFlashStatus = pdFAIL;
166 crDELAY( xHandle, xFlashRates[ uxIndex ] );
169 /* Co-routines MUST end with a call to crEND. */
172 /*-----------------------------------------------------------*/
174 static void prvFlashCoRoutine( CoRoutineHandle_t xHandle, unsigned portBASE_TYPE uxIndex )
176 /* Even though this is a co-routine the variable do not need to be
177 static as we do not need it to maintain their state between blocks. */
178 signed portBASE_TYPE xResult;
179 unsigned portBASE_TYPE uxLEDToFlash;
181 /* Co-routines MUST start with a call to crSTART. */
187 /* Block to wait for the number of the LED to flash. */
188 crQUEUE_RECEIVE( xHandle, xFlashQueue, &uxLEDToFlash, portMAX_DELAY, &xResult );
190 if( xResult != pdPASS )
192 /* We would not expect to wake unless we received something. */
193 uxCoRoutineFlashStatus = pdFAIL;
197 /* We received the number of an LED to flash - flash it! */
198 /* Added by MPi, PDR00_Offset is added in order to make the
199 vParTestToggleLED() work. */
200 vParTestToggleLED( uxLEDToFlash + PDR00_Offset );
204 /* Co-routines MUST end with a call to crEND. */
207 /*-----------------------------------------------------------*/
209 portBASE_TYPE xAreFlashCoRoutinesStillRunning( void )
211 /* Return pdPASS or pdFAIL depending on whether an error has been detected
213 return uxCoRoutineFlashStatus;