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| 1 | +/* |
| 2 | + * FreeRTOS Kernel V10.2.1 |
| 3 | + * Copyright (C) 2019 Amazon.com, Inc. or its affiliates. All Rights Reserved. |
| 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 | +#include "FreeRTOS.h" |
| 29 | +#include "task.h" |
| 30 | +#include "croutine.h" |
| 31 | + |
| 32 | +/* Remove the whole file is co-routines are not being used. */ |
| 33 | +#if( configUSE_CO_ROUTINES != 0 ) |
| 34 | + |
| 35 | +/* |
| 36 | + * Some kernel aware debuggers require data to be viewed to be global, rather |
| 37 | + * than file scope. |
| 38 | + */ |
| 39 | +#ifdef portREMOVE_STATIC_QUALIFIER |
| 40 | + #define static |
| 41 | +#endif |
| 42 | + |
| 43 | + |
| 44 | +/* Lists for ready and blocked co-routines. --------------------*/ |
| 45 | +static List_t pxReadyCoRoutineLists[ configMAX_CO_ROUTINE_PRIORITIES ]; /*< Prioritised ready co-routines. */ |
| 46 | +static List_t xDelayedCoRoutineList1; /*< Delayed co-routines. */ |
| 47 | +static List_t xDelayedCoRoutineList2; /*< Delayed co-routines (two lists are used - one for delays that have overflowed the current tick count. */ |
| 48 | +static List_t * pxDelayedCoRoutineList; /*< Points to the delayed co-routine list currently being used. */ |
| 49 | +static List_t * pxOverflowDelayedCoRoutineList; /*< Points to the delayed co-routine list currently being used to hold co-routines that have overflowed the current tick count. */ |
| 50 | +static List_t xPendingReadyCoRoutineList; /*< Holds co-routines that have been readied by an external event. They cannot be added directly to the ready lists as the ready lists cannot be accessed by interrupts. */ |
| 51 | + |
| 52 | +/* Other file private variables. --------------------------------*/ |
| 53 | +CRCB_t * pxCurrentCoRoutine = NULL; |
| 54 | +static UBaseType_t uxTopCoRoutineReadyPriority = 0; |
| 55 | +static TickType_t xCoRoutineTickCount = 0, xLastTickCount = 0, xPassedTicks = 0; |
| 56 | + |
| 57 | +/* The initial state of the co-routine when it is created. */ |
| 58 | +#define corINITIAL_STATE ( 0 ) |
| 59 | + |
| 60 | +/* |
| 61 | + * Place the co-routine represented by pxCRCB into the appropriate ready queue |
| 62 | + * for the priority. It is inserted at the end of the list. |
| 63 | + * |
| 64 | + * This macro accesses the co-routine ready lists and therefore must not be |
| 65 | + * used from within an ISR. |
| 66 | + */ |
| 67 | +#define prvAddCoRoutineToReadyQueue( pxCRCB ) \ |
| 68 | +{ \ |
| 69 | + if( pxCRCB->uxPriority > uxTopCoRoutineReadyPriority ) \ |
| 70 | + { \ |
| 71 | + uxTopCoRoutineReadyPriority = pxCRCB->uxPriority; \ |
| 72 | + } \ |
| 73 | + vListInsertEnd( ( List_t * ) &( pxReadyCoRoutineLists[ pxCRCB->uxPriority ] ), &( pxCRCB->xGenericListItem ) ); \ |
| 74 | +} |
| 75 | + |
| 76 | +/* |
| 77 | + * Utility to ready all the lists used by the scheduler. This is called |
| 78 | + * automatically upon the creation of the first co-routine. |
| 79 | + */ |
| 80 | +static void prvInitialiseCoRoutineLists( void ); |
| 81 | + |
| 82 | +/* |
| 83 | + * Co-routines that are readied by an interrupt cannot be placed directly into |
| 84 | + * the ready lists (there is no mutual exclusion). Instead they are placed in |
| 85 | + * in the pending ready list in order that they can later be moved to the ready |
| 86 | + * list by the co-routine scheduler. |
| 87 | + */ |
| 88 | +static void prvCheckPendingReadyList( void ); |
| 89 | + |
| 90 | +/* |
| 91 | + * Macro that looks at the list of co-routines that are currently delayed to |
| 92 | + * see if any require waking. |
| 93 | + * |
| 94 | + * Co-routines are stored in the queue in the order of their wake time - |
| 95 | + * meaning once one co-routine has been found whose timer has not expired |
| 96 | + * we need not look any further down the list. |
| 97 | + */ |
| 98 | +static void prvCheckDelayedList( void ); |
| 99 | + |
| 100 | +/*-----------------------------------------------------------*/ |
| 101 | + |
| 102 | +BaseType_t xCoRoutineCreate( crCOROUTINE_CODE pxCoRoutineCode, UBaseType_t uxPriority, UBaseType_t uxIndex ) |
| 103 | +{ |
| 104 | +BaseType_t xReturn; |
| 105 | +CRCB_t *pxCoRoutine; |
| 106 | + |
| 107 | + /* Allocate the memory that will store the co-routine control block. */ |
| 108 | + pxCoRoutine = ( CRCB_t * ) pvPortMalloc( sizeof( CRCB_t ) ); |
| 109 | + if( pxCoRoutine ) |
| 110 | + { |
| 111 | + /* If pxCurrentCoRoutine is NULL then this is the first co-routine to |
| 112 | + be created and the co-routine data structures need initialising. */ |
| 113 | + if( pxCurrentCoRoutine == NULL ) |
| 114 | + { |
| 115 | + pxCurrentCoRoutine = pxCoRoutine; |
| 116 | + prvInitialiseCoRoutineLists(); |
| 117 | + } |
| 118 | + |
| 119 | + /* Check the priority is within limits. */ |
| 120 | + if( uxPriority >= configMAX_CO_ROUTINE_PRIORITIES ) |
| 121 | + { |
| 122 | + uxPriority = configMAX_CO_ROUTINE_PRIORITIES - 1; |
| 123 | + } |
| 124 | + |
| 125 | + /* Fill out the co-routine control block from the function parameters. */ |
| 126 | + pxCoRoutine->uxState = corINITIAL_STATE; |
| 127 | + pxCoRoutine->uxPriority = uxPriority; |
| 128 | + pxCoRoutine->uxIndex = uxIndex; |
| 129 | + pxCoRoutine->pxCoRoutineFunction = pxCoRoutineCode; |
| 130 | + |
| 131 | + /* Initialise all the other co-routine control block parameters. */ |
| 132 | + vListInitialiseItem( &( pxCoRoutine->xGenericListItem ) ); |
| 133 | + vListInitialiseItem( &( pxCoRoutine->xEventListItem ) ); |
| 134 | + |
| 135 | + /* Set the co-routine control block as a link back from the ListItem_t. |
| 136 | + This is so we can get back to the containing CRCB from a generic item |
| 137 | + in a list. */ |
| 138 | + listSET_LIST_ITEM_OWNER( &( pxCoRoutine->xGenericListItem ), pxCoRoutine ); |
| 139 | + listSET_LIST_ITEM_OWNER( &( pxCoRoutine->xEventListItem ), pxCoRoutine ); |
| 140 | + |
| 141 | + /* Event lists are always in priority order. */ |
| 142 | + listSET_LIST_ITEM_VALUE( &( pxCoRoutine->xEventListItem ), ( ( TickType_t ) configMAX_CO_ROUTINE_PRIORITIES - ( TickType_t ) uxPriority ) ); |
| 143 | + |
| 144 | + /* Now the co-routine has been initialised it can be added to the ready |
| 145 | + list at the correct priority. */ |
| 146 | + prvAddCoRoutineToReadyQueue( pxCoRoutine ); |
| 147 | + |
| 148 | + xReturn = pdPASS; |
| 149 | + } |
| 150 | + else |
| 151 | + { |
| 152 | + xReturn = errCOULD_NOT_ALLOCATE_REQUIRED_MEMORY; |
| 153 | + } |
| 154 | + |
| 155 | + return xReturn; |
| 156 | +} |
| 157 | +/*-----------------------------------------------------------*/ |
| 158 | + |
| 159 | +void vCoRoutineAddToDelayedList( TickType_t xTicksToDelay, List_t *pxEventList ) |
| 160 | +{ |
| 161 | +TickType_t xTimeToWake; |
| 162 | + |
| 163 | + /* Calculate the time to wake - this may overflow but this is |
| 164 | + not a problem. */ |
| 165 | + xTimeToWake = xCoRoutineTickCount + xTicksToDelay; |
| 166 | + |
| 167 | + /* We must remove ourselves from the ready list before adding |
| 168 | + ourselves to the blocked list as the same list item is used for |
| 169 | + both lists. */ |
| 170 | + ( void ) uxListRemove( ( ListItem_t * ) &( pxCurrentCoRoutine->xGenericListItem ) ); |
| 171 | + |
| 172 | + /* The list item will be inserted in wake time order. */ |
| 173 | + listSET_LIST_ITEM_VALUE( &( pxCurrentCoRoutine->xGenericListItem ), xTimeToWake ); |
| 174 | + |
| 175 | + if( xTimeToWake < xCoRoutineTickCount ) |
| 176 | + { |
| 177 | + /* Wake time has overflowed. Place this item in the |
| 178 | + overflow list. */ |
| 179 | + vListInsert( ( List_t * ) pxOverflowDelayedCoRoutineList, ( ListItem_t * ) &( pxCurrentCoRoutine->xGenericListItem ) ); |
| 180 | + } |
| 181 | + else |
| 182 | + { |
| 183 | + /* The wake time has not overflowed, so we can use the |
| 184 | + current block list. */ |
| 185 | + vListInsert( ( List_t * ) pxDelayedCoRoutineList, ( ListItem_t * ) &( pxCurrentCoRoutine->xGenericListItem ) ); |
| 186 | + } |
| 187 | + |
| 188 | + if( pxEventList ) |
| 189 | + { |
| 190 | + /* Also add the co-routine to an event list. If this is done then the |
| 191 | + function must be called with interrupts disabled. */ |
| 192 | + vListInsert( pxEventList, &( pxCurrentCoRoutine->xEventListItem ) ); |
| 193 | + } |
| 194 | +} |
| 195 | +/*-----------------------------------------------------------*/ |
| 196 | + |
| 197 | +static void prvCheckPendingReadyList( void ) |
| 198 | +{ |
| 199 | + /* Are there any co-routines waiting to get moved to the ready list? These |
| 200 | + are co-routines that have been readied by an ISR. The ISR cannot access |
| 201 | + the ready lists itself. */ |
| 202 | + while( listLIST_IS_EMPTY( &xPendingReadyCoRoutineList ) == pdFALSE ) |
| 203 | + { |
| 204 | + CRCB_t *pxUnblockedCRCB; |
| 205 | + |
| 206 | + /* The pending ready list can be accessed by an ISR. */ |
| 207 | + portDISABLE_INTERRUPTS(); |
| 208 | + { |
| 209 | + pxUnblockedCRCB = ( CRCB_t * ) listGET_OWNER_OF_HEAD_ENTRY( (&xPendingReadyCoRoutineList) ); |
| 210 | + ( void ) uxListRemove( &( pxUnblockedCRCB->xEventListItem ) ); |
| 211 | + } |
| 212 | + portENABLE_INTERRUPTS(); |
| 213 | + |
| 214 | + ( void ) uxListRemove( &( pxUnblockedCRCB->xGenericListItem ) ); |
| 215 | + prvAddCoRoutineToReadyQueue( pxUnblockedCRCB ); |
| 216 | + } |
| 217 | +} |
| 218 | +/*-----------------------------------------------------------*/ |
| 219 | + |
| 220 | +static void prvCheckDelayedList( void ) |
| 221 | +{ |
| 222 | +CRCB_t *pxCRCB; |
| 223 | + |
| 224 | + xPassedTicks = xTaskGetTickCount() - xLastTickCount; |
| 225 | + while( xPassedTicks ) |
| 226 | + { |
| 227 | + xCoRoutineTickCount++; |
| 228 | + xPassedTicks--; |
| 229 | + |
| 230 | + /* If the tick count has overflowed we need to swap the ready lists. */ |
| 231 | + if( xCoRoutineTickCount == 0 ) |
| 232 | + { |
| 233 | + List_t * pxTemp; |
| 234 | + |
| 235 | + /* Tick count has overflowed so we need to swap the delay lists. If there are |
| 236 | + any items in pxDelayedCoRoutineList here then there is an error! */ |
| 237 | + pxTemp = pxDelayedCoRoutineList; |
| 238 | + pxDelayedCoRoutineList = pxOverflowDelayedCoRoutineList; |
| 239 | + pxOverflowDelayedCoRoutineList = pxTemp; |
| 240 | + } |
| 241 | + |
| 242 | + /* See if this tick has made a timeout expire. */ |
| 243 | + while( listLIST_IS_EMPTY( pxDelayedCoRoutineList ) == pdFALSE ) |
| 244 | + { |
| 245 | + pxCRCB = ( CRCB_t * ) listGET_OWNER_OF_HEAD_ENTRY( pxDelayedCoRoutineList ); |
| 246 | + |
| 247 | + if( xCoRoutineTickCount < listGET_LIST_ITEM_VALUE( &( pxCRCB->xGenericListItem ) ) ) |
| 248 | + { |
| 249 | + /* Timeout not yet expired. */ |
| 250 | + break; |
| 251 | + } |
| 252 | + |
| 253 | + portDISABLE_INTERRUPTS(); |
| 254 | + { |
| 255 | + /* The event could have occurred just before this critical |
| 256 | + section. If this is the case then the generic list item will |
| 257 | + have been moved to the pending ready list and the following |
| 258 | + line is still valid. Also the pvContainer parameter will have |
| 259 | + been set to NULL so the following lines are also valid. */ |
| 260 | + ( void ) uxListRemove( &( pxCRCB->xGenericListItem ) ); |
| 261 | + |
| 262 | + /* Is the co-routine waiting on an event also? */ |
| 263 | + if( pxCRCB->xEventListItem.pxContainer ) |
| 264 | + { |
| 265 | + ( void ) uxListRemove( &( pxCRCB->xEventListItem ) ); |
| 266 | + } |
| 267 | + } |
| 268 | + portENABLE_INTERRUPTS(); |
| 269 | + |
| 270 | + prvAddCoRoutineToReadyQueue( pxCRCB ); |
| 271 | + } |
| 272 | + } |
| 273 | + |
| 274 | + xLastTickCount = xCoRoutineTickCount; |
| 275 | +} |
| 276 | +/*-----------------------------------------------------------*/ |
| 277 | + |
| 278 | +void vCoRoutineSchedule( void ) |
| 279 | +{ |
| 280 | + /* See if any co-routines readied by events need moving to the ready lists. */ |
| 281 | + prvCheckPendingReadyList(); |
| 282 | + |
| 283 | + /* See if any delayed co-routines have timed out. */ |
| 284 | + prvCheckDelayedList(); |
| 285 | + |
| 286 | + /* Find the highest priority queue that contains ready co-routines. */ |
| 287 | + while( listLIST_IS_EMPTY( &( pxReadyCoRoutineLists[ uxTopCoRoutineReadyPriority ] ) ) ) |
| 288 | + { |
| 289 | + if( uxTopCoRoutineReadyPriority == 0 ) |
| 290 | + { |
| 291 | + /* No more co-routines to check. */ |
| 292 | + return; |
| 293 | + } |
| 294 | + --uxTopCoRoutineReadyPriority; |
| 295 | + } |
| 296 | + |
| 297 | + /* listGET_OWNER_OF_NEXT_ENTRY walks through the list, so the co-routines |
| 298 | + of the same priority get an equal share of the processor time. */ |
| 299 | + listGET_OWNER_OF_NEXT_ENTRY( pxCurrentCoRoutine, &( pxReadyCoRoutineLists[ uxTopCoRoutineReadyPriority ] ) ); |
| 300 | + |
| 301 | + /* Call the co-routine. */ |
| 302 | + ( pxCurrentCoRoutine->pxCoRoutineFunction )( pxCurrentCoRoutine, pxCurrentCoRoutine->uxIndex ); |
| 303 | + |
| 304 | + return; |
| 305 | +} |
| 306 | +/*-----------------------------------------------------------*/ |
| 307 | + |
| 308 | +static void prvInitialiseCoRoutineLists( void ) |
| 309 | +{ |
| 310 | +UBaseType_t uxPriority; |
| 311 | + |
| 312 | + for( uxPriority = 0; uxPriority < configMAX_CO_ROUTINE_PRIORITIES; uxPriority++ ) |
| 313 | + { |
| 314 | + vListInitialise( ( List_t * ) &( pxReadyCoRoutineLists[ uxPriority ] ) ); |
| 315 | + } |
| 316 | + |
| 317 | + vListInitialise( ( List_t * ) &xDelayedCoRoutineList1 ); |
| 318 | + vListInitialise( ( List_t * ) &xDelayedCoRoutineList2 ); |
| 319 | + vListInitialise( ( List_t * ) &xPendingReadyCoRoutineList ); |
| 320 | + |
| 321 | + /* Start with pxDelayedCoRoutineList using list1 and the |
| 322 | + pxOverflowDelayedCoRoutineList using list2. */ |
| 323 | + pxDelayedCoRoutineList = &xDelayedCoRoutineList1; |
| 324 | + pxOverflowDelayedCoRoutineList = &xDelayedCoRoutineList2; |
| 325 | +} |
| 326 | +/*-----------------------------------------------------------*/ |
| 327 | + |
| 328 | +BaseType_t xCoRoutineRemoveFromEventList( const List_t *pxEventList ) |
| 329 | +{ |
| 330 | +CRCB_t *pxUnblockedCRCB; |
| 331 | +BaseType_t xReturn; |
| 332 | + |
| 333 | + /* This function is called from within an interrupt. It can only access |
| 334 | + event lists and the pending ready list. This function assumes that a |
| 335 | + check has already been made to ensure pxEventList is not empty. */ |
| 336 | + pxUnblockedCRCB = ( CRCB_t * ) listGET_OWNER_OF_HEAD_ENTRY( pxEventList ); |
| 337 | + ( void ) uxListRemove( &( pxUnblockedCRCB->xEventListItem ) ); |
| 338 | + vListInsertEnd( ( List_t * ) &( xPendingReadyCoRoutineList ), &( pxUnblockedCRCB->xEventListItem ) ); |
| 339 | + |
| 340 | + if( pxUnblockedCRCB->uxPriority >= pxCurrentCoRoutine->uxPriority ) |
| 341 | + { |
| 342 | + xReturn = pdTRUE; |
| 343 | + } |
| 344 | + else |
| 345 | + { |
| 346 | + xReturn = pdFALSE; |
| 347 | + } |
| 348 | + |
| 349 | + return xReturn; |
| 350 | +} |
| 351 | + |
| 352 | +#endif /* configUSE_CO_ROUTINES == 0 */ |
| 353 | + |
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