00001 /* 00002 FreeRTOS V6.0.0 - Copyright (C) 2009 Real Time Engineers Ltd. 00003 00004 *************************************************************************** 00005 * * 00006 * If you are: * 00007 * * 00008 * + New to FreeRTOS, * 00009 * + Wanting to learn FreeRTOS or multitasking in general quickly * 00010 * + Looking for basic training, * 00011 * + Wanting to improve your FreeRTOS skills and productivity * 00012 * * 00013 * then take a look at the FreeRTOS eBook * 00014 * * 00015 * "Using the FreeRTOS Real Time Kernel - a Practical Guide" * 00016 * http://www.FreeRTOS.org/Documentation * 00017 * * 00018 * A pdf reference manual is also available. Both are usually delivered * 00019 * to your inbox within 20 minutes to two hours when purchased between 8am * 00020 * and 8pm GMT (although please allow up to 24 hours in case of * 00021 * exceptional circumstances). Thank you for your support! * 00022 * * 00023 *************************************************************************** 00024 00025 This file is part of the FreeRTOS distribution. 00026 00027 FreeRTOS is free software; you can redistribute it and/or modify it under 00028 the terms of the GNU General Public License (version 2) as published by the 00029 Free Software Foundation AND MODIFIED BY the FreeRTOS exception. 00030 ***NOTE*** The exception to the GPL is included to allow you to distribute 00031 a combined work that includes FreeRTOS without being obliged to provide the 00032 source code for proprietary components outside of the FreeRTOS kernel. 00033 FreeRTOS is distributed in the hope that it will be useful, but WITHOUT 00034 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 00035 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for 00036 more details. You should have received a copy of the GNU General Public 00037 License and the FreeRTOS license exception along with FreeRTOS; if not it 00038 can be viewed here: http://www.freertos.org/a00114.html and also obtained 00039 by writing to Richard Barry, contact details for whom are available on the 00040 FreeRTOS WEB site. 00041 00042 1 tab == 4 spaces! 00043 00044 http://www.FreeRTOS.org - Documentation, latest information, license and 00045 contact details. 00046 00047 http://www.SafeRTOS.com - A version that is certified for use in safety 00048 critical systems. 00049 00050 http://www.OpenRTOS.com - Commercial support, development, porting, 00051 licensing and training services. 00052 */ 00053 00054 /* 00055 * This version of integer. c is for use on systems that have limited stack 00056 * space and no display facilities. The complete version can be found in 00057 * the Demo/Common/Full directory. 00058 * 00059 * As with the full version, the tasks created in this file are a good test 00060 * of the scheduler context switch mechanism. The processor has to access 00061 * 32bit variables in two or four chunks (depending on the processor). The low 00062 * priority of these tasks means there is a high probability that a context 00063 * switch will occur mid calculation. See flop. c documentation for 00064 * more information. 00065 * 00066 */ 00067 00068 /* 00069 Changes from V1.2.1 00070 00071 + The constants used in the calculations are larger to ensure the 00072 optimiser does not truncate them to 16 bits. 00073 00074 Changes from V1.2.3 00075 00076 + uxTaskCheck is now just used as a boolean. Instead of incrementing 00077 the variable each cycle of the task, the variable is simply set to 00078 true. sAreIntegerMathsTaskStillRunning() sets it back to false and 00079 expects it to have been set back to true by the time it is called 00080 again. 00081 + A division has been included in the calculation. 00082 */ 00083 00084 #include <stdlib.h> 00085 00086 /* Scheduler include files. */ 00087 #include "FreeRTOS.h" 00088 #include "task.h" 00089 00090 /* Demo program include files. */ 00091 #include "integer.h" 00092 00093 /* The constants used in the calculation. */ 00094 #define intgCONST1 ( ( long ) 123 ) 00095 #define intgCONST2 ( ( long ) 234567 ) 00096 #define intgCONST3 ( ( long ) -3 ) 00097 #define intgCONST4 ( ( long ) 7 ) 00098 #define intgEXPECTED_ANSWER ( ( ( intgCONST1 + intgCONST2 ) * intgCONST3 ) / intgCONST4 ) 00099 00100 #define intgSTACK_SIZE configMINIMAL_STACK_SIZE 00101 00102 /* As this is the minimal version, we will only create one task. */ 00103 #define intgNUMBER_OF_TASKS ( 1 ) 00104 00105 /* The task function. Repeatedly performs a 32 bit calculation, checking the 00106 result against the expected result. If the result is incorrect then the 00107 context switch must have caused some corruption. */ 00108 static portTASK_FUNCTION_PROTO( vCompeteingIntMathTask, pvParameters ); 00109 00110 /* Variables that are set to true within the calculation task to indicate 00111 that the task is still executing. The check task sets the variable back to 00112 false, flagging an error if the variable is still false the next time it 00113 is called. */ 00114 static volatile signed portBASE_TYPE xTaskCheck[ intgNUMBER_OF_TASKS ] = { ( signed portBASE_TYPE ) pdFALSE }; 00115 00116 /*-----------------------------------------------------------*/ 00117 00118 void vStartIntegerMathTasks( unsigned portBASE_TYPE uxPriority ) 00119 { 00120 short sTask; 00121 00122 for( sTask = 0; sTask < intgNUMBER_OF_TASKS; sTask++ ) 00123 { 00124 xTaskCreate( vCompeteingIntMathTask, ( signed char * ) "IntMath", intgSTACK_SIZE, ( void * ) &( xTaskCheck[ sTask ] ), uxPriority, ( xTaskHandle * ) NULL ); 00125 } 00126 } 00127 /*-----------------------------------------------------------*/ 00128 00129 static portTASK_FUNCTION( vCompeteingIntMathTask, pvParameters ) 00130 { 00131 /* These variables are all effectively set to constants so they are volatile to 00132 ensure the compiler does not just get rid of them. */ 00133 volatile long lValue; 00134 short sError = pdFALSE; 00135 volatile signed portBASE_TYPE *pxTaskHasExecuted; 00136 00137 /* Set a pointer to the variable we are going to set to true each 00138 iteration. This is also a good test of the parameter passing mechanism 00139 within each port. */ 00140 pxTaskHasExecuted = ( volatile signed portBASE_TYPE * ) pvParameters; 00141 00142 /* Keep performing a calculation and checking the result against a constant. */ 00143 for( ;; ) 00144 { 00145 /* Perform the calculation. This will store partial value in 00146 registers, resulting in a good test of the context switch mechanism. */ 00147 lValue = intgCONST1; 00148 lValue += intgCONST2; 00149 00150 /* Yield in case cooperative scheduling is being used. */ 00151 #if configUSE_PREEMPTION == 0 00152 { 00153 taskYIELD(); 00154 } 00155 #endif 00156 00157 /* Finish off the calculation. */ 00158 lValue *= intgCONST3; 00159 lValue /= intgCONST4; 00160 00161 /* If the calculation is found to be incorrect we stop setting the 00162 TaskHasExecuted variable so the check task can see an error has 00163 occurred. */ 00164 if( lValue != intgEXPECTED_ANSWER ) /*lint !e774 volatile used to prevent this being optimised out. */ 00165 { 00166 sError = pdTRUE; 00167 } 00168 00169 if( sError == pdFALSE ) 00170 { 00171 /* We have not encountered any errors, so set the flag that show 00172 we are still executing. This will be periodically cleared by 00173 the check task. */ 00174 portENTER_CRITICAL(); 00175 *pxTaskHasExecuted = pdTRUE; 00176 portEXIT_CRITICAL(); 00177 } 00178 00179 /* Yield in case cooperative scheduling is being used. */ 00180 #if configUSE_PREEMPTION == 0 00181 { 00182 taskYIELD(); 00183 } 00184 #endif 00185 } 00186 } 00187 /*-----------------------------------------------------------*/ 00188 00189 /* This is called to check that all the created tasks are still running. */ 00190 portBASE_TYPE xAreIntegerMathsTaskStillRunning( void ) 00191 { 00192 portBASE_TYPE xReturn = pdTRUE; 00193 short sTask; 00194 00195 /* Check the maths tasks are still running by ensuring their check variables 00196 are still being set to true. */ 00197 for( sTask = 0; sTask < intgNUMBER_OF_TASKS; sTask++ ) 00198 { 00199 if( xTaskCheck[ sTask ] == pdFALSE ) 00200 { 00201 /* The check has not incremented so an error exists. */ 00202 xReturn = pdFALSE; 00203 } 00204 00205 /* Reset the check variable so we can tell if it has been set by 00206 the next time around. */ 00207 xTaskCheck[ sTask ] = pdFALSE; 00208 } 00209 00210 return xReturn; 00211 } 00212