begriffs open source - cmsis-freertos/blob

1 /*

2 * FreeRTOS Kernel V10.2.1

4 *

5 * Permission is hereby granted, free of charge, to any person obtaining a copy of

6 * this software and associated documentation files (the "Software"), to deal in

7 * the Software without restriction, including without limitation the rights to

8 * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of

9 * the Software, and to permit persons to whom the Software is furnished to do so,

10 * subject to the following conditions:

11 *

12 * The above copyright notice and this permission notice shall be included in all

13 * copies or substantial portions of the Software.

14 *

15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR

16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS

17 * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR

18 * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER

19 * IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN

20 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

21 *

22 * http://www.FreeRTOS.org

23 * http://aws.amazon.com/freertos

24 *

25 * 1 tab == 4 spaces!

26 */

27

28 /*

29 * Instead of the normal single demo application, the PIC18F demo is split

30 * into several smaller programs of which this is the first. This enables the

31 * demo's to be executed on the RAM limited 40 pin devices. The 64 and 80 pin

32 * devices require a more costly development platform and are not so readily

33 * available.

34 *

35 * The RTOSDemo1 project is configured for a PIC18F452 device. Main1.c starts 5

36 * tasks (including the idle task).

37 *

38 * The first task runs at the idle priority. It repeatedly performs a 32bit

39 * calculation and checks it's result against the expected value. This checks

40 * that the temporary storage utilised by the compiler to hold intermediate

41 * results does not get corrupted when the task gets switched in and out. See

42 * demo/common/minimal/integer.c for more information.

43 *

44 * The second and third tasks pass an incrementing value between each other on

45 * a message queue. See demo/common/minimal/PollQ.c for more information.

46 *

47 * Main1.c also creates a check task. This periodically checks that all the

48 * other tasks are still running and have not experienced any unexpected

49 * results. If all the other tasks are executing correctly an LED is flashed

50 * once every mainCHECK_PERIOD milliseconds. If any of the tasks have not

51 * executed, or report and error, the frequency of the LED flash will increase

52 * to mainERROR_FLASH_RATE.

53 *

54 * On entry to main an 'X' is transmitted. Monitoring the serial port using a

55 * dumb terminal allows for verification that the device is not continuously

56 * being reset (no more than one 'X' should be transmitted).

57 *

58 * http://www.FreeRTOS.org contains important information on the use of the

59 * PIC18F port.

60 */

61

62 /*

63 Changes from V2.0.0

64

65 + Delay periods are now specified using variables and constants of

66 TickType_t rather than unsigned long.

67 */

68

69 /* Scheduler include files. */

70 #include "FreeRTOS.h"

71 #include "task.h"

72

73 /* Demo app include files. */

74 #include "PollQ.h"

75 #include "integer.h"

76 #include "partest.h"

77 #include "serial.h"

78

79 /* The period between executions of the check task before and after an error

80 has been discovered. If an error has been discovered the check task runs

81 more frequently - increasing the LED flash rate. */

82 #define mainNO_ERROR_CHECK_PERIOD ( ( TickType_t ) 1000 / portTICK_PERIOD_MS )

83 #define mainERROR_CHECK_PERIOD ( ( TickType_t ) 100 / portTICK_PERIOD_MS )

84

85 /* Priority definitions for some of the tasks. Other tasks just use the idle

86 priority. */

87 #define mainQUEUE_POLL_PRIORITY ( tskIDLE_PRIORITY + 2 )

88 #define mainCHECK_TASK_PRIORITY ( tskIDLE_PRIORITY + 3 )

89

90 /* The LED that is flashed by the check task. */

91 #define mainCHECK_TASK_LED ( 0 )

92

93 /* Constants required for the communications. Only one character is ever

94 transmitted. */

95 #define mainCOMMS_QUEUE_LENGTH ( 5 )

96 #define mainNO_BLOCK ( ( TickType_t ) 0 )

97 #define mainBAUD_RATE ( ( unsigned long ) 9600 )

98

99 /*

100 * The task function for the "Check" task.

101 */

102 static void vErrorChecks( void *pvParameters );

103

104 /*

105 * Checks the unique counts of other tasks to ensure they are still operational.

106 * Returns pdTRUE if an error is detected, otherwise pdFALSE.

107 */

108 static portBASE_TYPE prvCheckOtherTasksAreStillRunning( void );

109

110 /*-----------------------------------------------------------*/

111

112 /* Creates the tasks, then starts the scheduler. */

113 void main( void )

114 {

115 /* Initialise the required hardware. */

116 vParTestInitialise();

117 vPortInitialiseBlocks();

118

119 /* Send a character so we have some visible feedback of a reset. */

120 xSerialPortInitMinimal( mainBAUD_RATE, mainCOMMS_QUEUE_LENGTH );

121 xSerialPutChar( NULL, 'X', mainNO_BLOCK );

122

123 /* Start the standard demo tasks found in the demo\common directory. */

124 vStartIntegerMathTasks( tskIDLE_PRIORITY );

125 vStartPolledQueueTasks( mainQUEUE_POLL_PRIORITY );

126

127 /* Start the check task defined in this file. */

128 xTaskCreate( vErrorChecks, "Check", configMINIMAL_STACK_SIZE, NULL, mainCHECK_TASK_PRIORITY, NULL );

129

130 /* Start the scheduler. Will never return here. */

131 vTaskStartScheduler();

132 }

133 /*-----------------------------------------------------------*/

134

135 static void vErrorChecks( void *pvParameters )

136 {

137 TickType_t xDelayTime = mainNO_ERROR_CHECK_PERIOD;

138 portBASE_TYPE xErrorOccurred;

139

140 /* Cycle for ever, delaying then checking all the other tasks are still

141 operating without error. */

142 for( ;; )

143 {

144 /* Wait until it is time to check the other tasks. */

145 vTaskDelay( xDelayTime );

146

147 /* Check all the other tasks are running, and running without ever

148 having an error. */

149 xErrorOccurred = prvCheckOtherTasksAreStillRunning();

150

151 /* If an error was detected increase the frequency of the LED flash. */

152 if( xErrorOccurred == pdTRUE )

153 {

154 xDelayTime = mainERROR_CHECK_PERIOD;

155 }

156

157 /* Flash the LED for visual feedback. */

158 vParTestToggleLED( mainCHECK_TASK_LED );

159 }

160 }

161 /*-----------------------------------------------------------*/

162

163 static portBASE_TYPE prvCheckOtherTasksAreStillRunning( void )

164 {

165 portBASE_TYPE xErrorHasOccurred = pdFALSE;

166

167 if( xAreIntegerMathsTaskStillRunning() != pdTRUE )

168 {

169 xErrorHasOccurred = pdTRUE;

170 }

171

172 if( xArePollingQueuesStillRunning() != pdTRUE )

173 {

174 xErrorHasOccurred = pdTRUE;

175 }

176

177 return xErrorHasOccurred;

178 }

179 /*-----------------------------------------------------------*/

180

181