2 FreeRTOS V4.0.1 - Copyright (C) 2003-2006 Richard Barry.
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4 This file is part of the FreeRTOS distribution.
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6 FreeRTOS is free software; you can redistribute it and/or modify
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7 it under the terms of the GNU General Public License as published by
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8 the Free Software Foundation; either version 2 of the License, or
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9 (at your option) any later version.
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11 FreeRTOS is distributed in the hope that it will be useful,
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12 but WITHOUT ANY WARRANTY; without even the implied warranty of
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13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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14 GNU General Public License for more details.
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16 You should have received a copy of the GNU General Public License
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17 along with FreeRTOS; if not, write to the Free Software
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18 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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20 A special exception to the GPL can be applied should you wish to distribute
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21 a combined work that includes FreeRTOS, without being obliged to provide
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22 the source code for any proprietary components. See the licensing section
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23 of http://www.FreeRTOS.org for full details of how and when the exception
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26 ***************************************************************************
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27 See http://www.FreeRTOS.org for documentation, latest information, license
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28 and contact details. Please ensure to read the configuration and relevant
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29 port sections of the online documentation.
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30 ***************************************************************************
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34 * This demo file demonstrates how to send data between an ISR and a
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35 * co-routine. A tick hook function is used to periodically pass data between
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36 * the RTOS tick and a set of 'hook' co-routines.
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38 * hookNUM_HOOK_CO_ROUTINES co-routines are created. Each co-routine blocks
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39 * to wait for a character to be received on a queue from the tick ISR, checks
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40 * to ensure the character received was that expected, then sends the number
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41 * back to the tick ISR on a different queue.
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43 * The tick ISR checks the numbers received back from the 'hook' co-routines
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44 * matches the number previously sent.
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46 * If at any time a queue function returns unexpectedly, or an incorrect value
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47 * is received either by the tick hook or a co-routine then an error is
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50 * This demo relies on each 'hook' co-routine to execute between each
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51 * hookTICK_CALLS_BEFORE_POST tick interrupts. This and the heavy use of
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52 * queues from within an interrupt may result in an error being detected on
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53 * slower targets simply due to timing.
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56 /* Scheduler includes. */
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57 #include "FreeRTOS.h"
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58 #include "croutine.h"
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61 /* Demo application includes. */
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64 /* The number of 'hook' co-routines that are to be created. */
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65 #define hookNUM_HOOK_CO_ROUTINES ( 4 )
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67 /* The number of times the tick hook should be called before a character is
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68 posted to the 'hook' co-routines. */
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69 #define hookTICK_CALLS_BEFORE_POST ( 250 )
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71 /* There should never be more than one item in any queue at any time. */
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72 #define hookHOOK_QUEUE_LENGTH ( 1 )
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74 /* Don't block when initially posting to the queue. */
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75 #define hookNO_BLOCK_TIME ( 0 )
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77 /* The priority relative to other co-routines (rather than tasks) that the
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78 'hook' co-routines should take. */
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79 #define mainHOOK_CR_PRIORITY ( 1 )
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80 /*-----------------------------------------------------------*/
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83 * The co-routine function itself.
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85 static void prvHookCoRoutine( xCoRoutineHandle xHandle, unsigned portBASE_TYPE uxIndex );
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89 * The tick hook function. This receives a number from each 'hook' co-routine
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90 * then sends a number to each co-routine. An error is flagged if a send or
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91 * receive fails, or an unexpected number is received.
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93 void vApplicationTickHook( void );
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95 /*-----------------------------------------------------------*/
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97 /* Queues used to send data FROM a co-routine TO the tick hook function.
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98 The hook functions received (Rx's) on these queues. One queue per
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99 'hook' co-routine. */
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100 static xQueueHandle xHookRxQueues[ hookNUM_HOOK_CO_ROUTINES ];
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102 /* Queues used to send data FROM the tick hook TO a co-routine function.
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103 The hood function transmits (Tx's) on these queues. One queue per
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104 'hook' co-routine. */
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105 static xQueueHandle xHookTxQueues[ hookNUM_HOOK_CO_ROUTINES ];
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107 /* Set to true if an error is detected at any time. */
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108 static portBASE_TYPE xCoRoutineErrorDetected = pdFALSE;
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110 /*-----------------------------------------------------------*/
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112 void vStartHookCoRoutines( void )
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114 unsigned portBASE_TYPE uxIndex, uxValueToPost = 0;
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116 for( uxIndex = 0; uxIndex < hookNUM_HOOK_CO_ROUTINES; uxIndex++ )
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118 /* Create a queue to transmit to and receive from each 'hook'
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120 xHookRxQueues[ uxIndex ] = xQueueCreate( hookHOOK_QUEUE_LENGTH, sizeof( unsigned portBASE_TYPE ) );
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121 xHookTxQueues[ uxIndex ] = xQueueCreate( hookHOOK_QUEUE_LENGTH, sizeof( unsigned portBASE_TYPE ) );
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123 /* To start things off the tick hook function expects the queue it
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124 uses to receive data to contain a value. */
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125 xQueueSend( xHookRxQueues[ uxIndex ], &uxValueToPost, hookNO_BLOCK_TIME );
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127 /* Create the 'hook' co-routine itself. */
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128 xCoRoutineCreate( prvHookCoRoutine, mainHOOK_CR_PRIORITY, uxIndex );
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131 /*-----------------------------------------------------------*/
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133 static unsigned portBASE_TYPE uxCallCounter = 0, uxNumberToPost = 0;
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134 void vApplicationTickHook( void )
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136 unsigned portBASE_TYPE uxReceivedNumber;
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137 signed portBASE_TYPE xIndex, xCoRoutineWoken;
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139 /* Is it time to talk to the 'hook' co-routines again? */
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141 if( uxCallCounter >= hookTICK_CALLS_BEFORE_POST )
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145 for( xIndex = 0; xIndex < hookNUM_HOOK_CO_ROUTINES; xIndex++ )
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147 xCoRoutineWoken = pdFALSE;
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148 if( crQUEUE_RECEIVE_FROM_ISR( xHookRxQueues[ xIndex ], &uxReceivedNumber, &xCoRoutineWoken ) != pdPASS )
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150 /* There is no reason why we would not expect the queue to
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151 contain a value. */
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152 xCoRoutineErrorDetected = pdTRUE;
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156 /* Each queue used to receive data from the 'hook' co-routines
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157 should contain the number we last posted to the same co-routine. */
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158 if( uxReceivedNumber != uxNumberToPost )
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160 xCoRoutineErrorDetected = pdTRUE;
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163 /* Nothing should be blocked waiting to post to the queue. */
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164 if( xCoRoutineWoken != pdFALSE )
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166 xCoRoutineErrorDetected = pdTRUE;
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171 /* Start the next cycle by posting the next number onto each Tx queue. */
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174 for( xIndex = 0; xIndex < hookNUM_HOOK_CO_ROUTINES; xIndex++ )
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176 if( crQUEUE_SEND_FROM_ISR( xHookTxQueues[ xIndex ], &uxNumberToPost, pdFALSE ) != pdTRUE )
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178 /* Posting to the queue should have woken the co-routine that
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179 was blocked on the queue. */
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180 xCoRoutineErrorDetected = pdTRUE;
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185 /*-----------------------------------------------------------*/
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187 static void prvHookCoRoutine( xCoRoutineHandle xHandle, unsigned portBASE_TYPE uxIndex )
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189 static unsigned portBASE_TYPE uxReceivedValue[ hookNUM_HOOK_CO_ROUTINES ];
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190 portBASE_TYPE xResult;
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192 /* Each co-routine MUST start with a call to crSTART(); */
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193 crSTART( xHandle );
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197 /* Wait to receive a value from the tick hook. */
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199 crQUEUE_RECEIVE( xHandle, xHookTxQueues[ uxIndex ], &( uxReceivedValue[ uxIndex ] ), portMAX_DELAY, &xResult );
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201 /* There is no reason why we should not have received something on
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203 if( xResult != pdPASS )
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205 xCoRoutineErrorDetected = pdTRUE;
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208 /* Send the same number back to the idle hook so it can verify it. */
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210 crQUEUE_SEND( xHandle, xHookRxQueues[ uxIndex ], &( uxReceivedValue[ uxIndex ] ), hookNO_BLOCK_TIME, &xResult );
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211 if( xResult != pdPASS )
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213 /* There is no reason why we should not have been able to post to
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215 xCoRoutineErrorDetected = pdTRUE;
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219 /* Each co-routine MUST end with a call to crEND(). */
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222 /*-----------------------------------------------------------*/
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224 portBASE_TYPE xAreHookCoRoutinesStillRunning( void )
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226 if( xCoRoutineErrorDetected )
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