1 /* 2 * FreeRTOS Kernel V11.0.1 3 * Copyright (C) 2021 Amazon.com, Inc. or its affiliates. All Rights Reserved. 4 * 5 * SPDX-License-Identifier: MIT 6 * 7 * Permission is hereby granted, free of charge, to any person obtaining a copy of 8 * this software and associated documentation files (the "Software"), to deal in 9 * the Software without restriction, including without limitation the rights to 10 * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of 11 * the Software, and to permit persons to whom the Software is furnished to do so, 12 * subject to the following conditions: 13 * 14 * The above copyright notice and this permission notice shall be included in all 15 * copies or substantial portions of the Software. 16 * 17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 18 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS 19 * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR 20 * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER 21 * IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN 22 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. 23 * 24 * https://www.FreeRTOS.org 25 * https://github.com/FreeRTOS 26 * 27 */ 28 29 #include "FreeRTOS.h" 30 #include "task.h" 31 #include "croutine.h" 32 33 /* Remove the whole file is co-routines are not being used. */ 34 #if ( configUSE_CO_ROUTINES != 0 ) 35 36 /* 37 * Some kernel aware debuggers require data to be viewed to be global, rather 38 * than file scope. 39 */ 40 #ifdef portREMOVE_STATIC_QUALIFIER 41 #define static 42 #endif 43 44 45 /* Lists for ready and blocked co-routines. --------------------*/ 46 static List_t pxReadyCoRoutineLists[ configMAX_CO_ROUTINE_PRIORITIES ]; /**< Prioritised ready co-routines. */ 47 static List_t xDelayedCoRoutineList1; /**< Delayed co-routines. */ 48 static List_t xDelayedCoRoutineList2; /**< Delayed co-routines (two lists are used - one for delays that have overflowed the current tick count. */ 49 static List_t * pxDelayedCoRoutineList = NULL; /**< Points to the delayed co-routine list currently being used. */ 50 static List_t * pxOverflowDelayedCoRoutineList = NULL; /**< Points to the delayed co-routine list currently being used to hold co-routines that have overflowed the current tick count. */ 51 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. */ 52 53 /* Other file private variables. --------------------------------*/ 54 CRCB_t * pxCurrentCoRoutine = NULL; 55 static UBaseType_t uxTopCoRoutineReadyPriority = 0; 56 static TickType_t xCoRoutineTickCount = 0, xLastTickCount = 0, xPassedTicks = 0; 57 58 /* The initial state of the co-routine when it is created. */ 59 #define corINITIAL_STATE ( 0 ) 60 61 /* 62 * Place the co-routine represented by pxCRCB into the appropriate ready queue 63 * for the priority. It is inserted at the end of the list. 64 * 65 * This macro accesses the co-routine ready lists and therefore must not be 66 * used from within an ISR. 67 */ 68 #define prvAddCoRoutineToReadyQueue( pxCRCB ) \ 69 do { \ 70 if( ( pxCRCB )->uxPriority > uxTopCoRoutineReadyPriority ) \ 71 { \ 72 uxTopCoRoutineReadyPriority = ( pxCRCB )->uxPriority; \ 73 } \ 74 vListInsertEnd( ( List_t * ) &( pxReadyCoRoutineLists[ ( pxCRCB )->uxPriority ] ), &( ( pxCRCB )->xGenericListItem ) ); \ 75 } while( 0 ) 76 77 /* 78 * Utility to ready all the lists used by the scheduler. This is called 79 * automatically upon the creation of the first co-routine. 80 */ 81 static void prvInitialiseCoRoutineLists( void ); 82 83 /* 84 * Co-routines that are readied by an interrupt cannot be placed directly into 85 * the ready lists (there is no mutual exclusion). Instead they are placed in 86 * in the pending ready list in order that they can later be moved to the ready 87 * list by the co-routine scheduler. 88 */ 89 static void prvCheckPendingReadyList( void ); 90 91 /* 92 * Macro that looks at the list of co-routines that are currently delayed to 93 * see if any require waking. 94 * 95 * Co-routines are stored in the queue in the order of their wake time - 96 * meaning once one co-routine has been found whose timer has not expired 97 * we need not look any further down the list. 98 */ 99 static void prvCheckDelayedList( void ); 100 101 /*-----------------------------------------------------------*/ 102 xCoRoutineCreate(crCOROUTINE_CODE pxCoRoutineCode,UBaseType_t uxPriority,UBaseType_t uxIndex)103 BaseType_t xCoRoutineCreate( crCOROUTINE_CODE pxCoRoutineCode, 104 UBaseType_t uxPriority, 105 UBaseType_t uxIndex ) 106 { 107 BaseType_t xReturn; 108 CRCB_t * pxCoRoutine; 109 110 traceENTER_xCoRoutineCreate( pxCoRoutineCode, uxPriority, uxIndex ); 111 112 /* Allocate the memory that will store the co-routine control block. */ 113 /* MISRA Ref 11.5.1 [Malloc memory assignment] */ 114 /* More details at: https://github.com/FreeRTOS/FreeRTOS-Kernel/blob/main/MISRA.md#rule-115 */ 115 /* coverity[misra_c_2012_rule_11_5_violation] */ 116 pxCoRoutine = ( CRCB_t * ) pvPortMalloc( sizeof( CRCB_t ) ); 117 118 if( pxCoRoutine ) 119 { 120 /* If pxCurrentCoRoutine is NULL then this is the first co-routine to 121 * be created and the co-routine data structures need initialising. */ 122 if( pxCurrentCoRoutine == NULL ) 123 { 124 pxCurrentCoRoutine = pxCoRoutine; 125 prvInitialiseCoRoutineLists(); 126 } 127 128 /* Check the priority is within limits. */ 129 if( uxPriority >= configMAX_CO_ROUTINE_PRIORITIES ) 130 { 131 uxPriority = configMAX_CO_ROUTINE_PRIORITIES - 1; 132 } 133 134 /* Fill out the co-routine control block from the function parameters. */ 135 pxCoRoutine->uxState = corINITIAL_STATE; 136 pxCoRoutine->uxPriority = uxPriority; 137 pxCoRoutine->uxIndex = uxIndex; 138 pxCoRoutine->pxCoRoutineFunction = pxCoRoutineCode; 139 140 /* Initialise all the other co-routine control block parameters. */ 141 vListInitialiseItem( &( pxCoRoutine->xGenericListItem ) ); 142 vListInitialiseItem( &( pxCoRoutine->xEventListItem ) ); 143 144 /* Set the co-routine control block as a link back from the ListItem_t. 145 * This is so we can get back to the containing CRCB from a generic item 146 * in a list. */ 147 listSET_LIST_ITEM_OWNER( &( pxCoRoutine->xGenericListItem ), pxCoRoutine ); 148 listSET_LIST_ITEM_OWNER( &( pxCoRoutine->xEventListItem ), pxCoRoutine ); 149 150 /* Event lists are always in priority order. */ 151 listSET_LIST_ITEM_VALUE( &( pxCoRoutine->xEventListItem ), ( ( TickType_t ) configMAX_CO_ROUTINE_PRIORITIES - ( TickType_t ) uxPriority ) ); 152 153 /* Now the co-routine has been initialised it can be added to the ready 154 * list at the correct priority. */ 155 prvAddCoRoutineToReadyQueue( pxCoRoutine ); 156 157 xReturn = pdPASS; 158 } 159 else 160 { 161 xReturn = errCOULD_NOT_ALLOCATE_REQUIRED_MEMORY; 162 } 163 164 traceRETURN_xCoRoutineCreate( xReturn ); 165 166 return xReturn; 167 } 168 /*-----------------------------------------------------------*/ 169 vCoRoutineAddToDelayedList(TickType_t xTicksToDelay,List_t * pxEventList)170 void vCoRoutineAddToDelayedList( TickType_t xTicksToDelay, 171 List_t * pxEventList ) 172 { 173 TickType_t xTimeToWake; 174 175 traceENTER_vCoRoutineAddToDelayedList( xTicksToDelay, pxEventList ); 176 177 /* Calculate the time to wake - this may overflow but this is 178 * not a problem. */ 179 xTimeToWake = xCoRoutineTickCount + xTicksToDelay; 180 181 /* We must remove ourselves from the ready list before adding 182 * ourselves to the blocked list as the same list item is used for 183 * both lists. */ 184 ( void ) uxListRemove( ( ListItem_t * ) &( pxCurrentCoRoutine->xGenericListItem ) ); 185 186 /* The list item will be inserted in wake time order. */ 187 listSET_LIST_ITEM_VALUE( &( pxCurrentCoRoutine->xGenericListItem ), xTimeToWake ); 188 189 if( xTimeToWake < xCoRoutineTickCount ) 190 { 191 /* Wake time has overflowed. Place this item in the 192 * overflow list. */ 193 vListInsert( ( List_t * ) pxOverflowDelayedCoRoutineList, ( ListItem_t * ) &( pxCurrentCoRoutine->xGenericListItem ) ); 194 } 195 else 196 { 197 /* The wake time has not overflowed, so we can use the 198 * current block list. */ 199 vListInsert( ( List_t * ) pxDelayedCoRoutineList, ( ListItem_t * ) &( pxCurrentCoRoutine->xGenericListItem ) ); 200 } 201 202 if( pxEventList ) 203 { 204 /* Also add the co-routine to an event list. If this is done then the 205 * function must be called with interrupts disabled. */ 206 vListInsert( pxEventList, &( pxCurrentCoRoutine->xEventListItem ) ); 207 } 208 209 traceRETURN_vCoRoutineAddToDelayedList(); 210 } 211 /*-----------------------------------------------------------*/ 212 prvCheckPendingReadyList(void)213 static void prvCheckPendingReadyList( void ) 214 { 215 /* Are there any co-routines waiting to get moved to the ready list? These 216 * are co-routines that have been readied by an ISR. The ISR cannot access 217 * the ready lists itself. */ 218 while( listLIST_IS_EMPTY( &xPendingReadyCoRoutineList ) == pdFALSE ) 219 { 220 CRCB_t * pxUnblockedCRCB; 221 222 /* The pending ready list can be accessed by an ISR. */ 223 portDISABLE_INTERRUPTS(); 224 { 225 pxUnblockedCRCB = ( CRCB_t * ) listGET_OWNER_OF_HEAD_ENTRY( ( &xPendingReadyCoRoutineList ) ); 226 ( void ) uxListRemove( &( pxUnblockedCRCB->xEventListItem ) ); 227 } 228 portENABLE_INTERRUPTS(); 229 230 ( void ) uxListRemove( &( pxUnblockedCRCB->xGenericListItem ) ); 231 prvAddCoRoutineToReadyQueue( pxUnblockedCRCB ); 232 } 233 } 234 /*-----------------------------------------------------------*/ 235 prvCheckDelayedList(void)236 static void prvCheckDelayedList( void ) 237 { 238 CRCB_t * pxCRCB; 239 240 xPassedTicks = xTaskGetTickCount() - xLastTickCount; 241 242 while( xPassedTicks ) 243 { 244 xCoRoutineTickCount++; 245 xPassedTicks--; 246 247 /* If the tick count has overflowed we need to swap the ready lists. */ 248 if( xCoRoutineTickCount == 0 ) 249 { 250 List_t * pxTemp; 251 252 /* Tick count has overflowed so we need to swap the delay lists. If there are 253 * any items in pxDelayedCoRoutineList here then there is an error! */ 254 pxTemp = pxDelayedCoRoutineList; 255 pxDelayedCoRoutineList = pxOverflowDelayedCoRoutineList; 256 pxOverflowDelayedCoRoutineList = pxTemp; 257 } 258 259 /* See if this tick has made a timeout expire. */ 260 while( listLIST_IS_EMPTY( pxDelayedCoRoutineList ) == pdFALSE ) 261 { 262 pxCRCB = ( CRCB_t * ) listGET_OWNER_OF_HEAD_ENTRY( pxDelayedCoRoutineList ); 263 264 if( xCoRoutineTickCount < listGET_LIST_ITEM_VALUE( &( pxCRCB->xGenericListItem ) ) ) 265 { 266 /* Timeout not yet expired. */ 267 break; 268 } 269 270 portDISABLE_INTERRUPTS(); 271 { 272 /* The event could have occurred just before this critical 273 * section. If this is the case then the generic list item will 274 * have been moved to the pending ready list and the following 275 * line is still valid. Also the pvContainer parameter will have 276 * been set to NULL so the following lines are also valid. */ 277 ( void ) uxListRemove( &( pxCRCB->xGenericListItem ) ); 278 279 /* Is the co-routine waiting on an event also? */ 280 if( pxCRCB->xEventListItem.pxContainer ) 281 { 282 ( void ) uxListRemove( &( pxCRCB->xEventListItem ) ); 283 } 284 } 285 portENABLE_INTERRUPTS(); 286 287 prvAddCoRoutineToReadyQueue( pxCRCB ); 288 } 289 } 290 291 xLastTickCount = xCoRoutineTickCount; 292 } 293 /*-----------------------------------------------------------*/ 294 vCoRoutineSchedule(void)295 void vCoRoutineSchedule( void ) 296 { 297 traceENTER_vCoRoutineSchedule(); 298 299 /* Only run a co-routine after prvInitialiseCoRoutineLists() has been 300 * called. prvInitialiseCoRoutineLists() is called automatically when a 301 * co-routine is created. */ 302 if( pxDelayedCoRoutineList != NULL ) 303 { 304 /* See if any co-routines readied by events need moving to the ready lists. */ 305 prvCheckPendingReadyList(); 306 307 /* See if any delayed co-routines have timed out. */ 308 prvCheckDelayedList(); 309 310 /* Find the highest priority queue that contains ready co-routines. */ 311 while( listLIST_IS_EMPTY( &( pxReadyCoRoutineLists[ uxTopCoRoutineReadyPriority ] ) ) ) 312 { 313 if( uxTopCoRoutineReadyPriority == 0 ) 314 { 315 /* No more co-routines to check. */ 316 return; 317 } 318 319 --uxTopCoRoutineReadyPriority; 320 } 321 322 /* listGET_OWNER_OF_NEXT_ENTRY walks through the list, so the co-routines 323 * of the same priority get an equal share of the processor time. */ 324 listGET_OWNER_OF_NEXT_ENTRY( pxCurrentCoRoutine, &( pxReadyCoRoutineLists[ uxTopCoRoutineReadyPriority ] ) ); 325 326 /* Call the co-routine. */ 327 ( pxCurrentCoRoutine->pxCoRoutineFunction )( pxCurrentCoRoutine, pxCurrentCoRoutine->uxIndex ); 328 } 329 330 traceRETURN_vCoRoutineSchedule(); 331 } 332 /*-----------------------------------------------------------*/ 333 prvInitialiseCoRoutineLists(void)334 static void prvInitialiseCoRoutineLists( void ) 335 { 336 UBaseType_t uxPriority; 337 338 for( uxPriority = 0; uxPriority < configMAX_CO_ROUTINE_PRIORITIES; uxPriority++ ) 339 { 340 vListInitialise( ( List_t * ) &( pxReadyCoRoutineLists[ uxPriority ] ) ); 341 } 342 343 vListInitialise( ( List_t * ) &xDelayedCoRoutineList1 ); 344 vListInitialise( ( List_t * ) &xDelayedCoRoutineList2 ); 345 vListInitialise( ( List_t * ) &xPendingReadyCoRoutineList ); 346 347 /* Start with pxDelayedCoRoutineList using list1 and the 348 * pxOverflowDelayedCoRoutineList using list2. */ 349 pxDelayedCoRoutineList = &xDelayedCoRoutineList1; 350 pxOverflowDelayedCoRoutineList = &xDelayedCoRoutineList2; 351 } 352 /*-----------------------------------------------------------*/ 353 xCoRoutineRemoveFromEventList(const List_t * pxEventList)354 BaseType_t xCoRoutineRemoveFromEventList( const List_t * pxEventList ) 355 { 356 CRCB_t * pxUnblockedCRCB; 357 BaseType_t xReturn; 358 359 traceENTER_xCoRoutineRemoveFromEventList( pxEventList ); 360 361 /* This function is called from within an interrupt. It can only access 362 * event lists and the pending ready list. This function assumes that a 363 * check has already been made to ensure pxEventList is not empty. */ 364 pxUnblockedCRCB = ( CRCB_t * ) listGET_OWNER_OF_HEAD_ENTRY( pxEventList ); 365 ( void ) uxListRemove( &( pxUnblockedCRCB->xEventListItem ) ); 366 vListInsertEnd( ( List_t * ) &( xPendingReadyCoRoutineList ), &( pxUnblockedCRCB->xEventListItem ) ); 367 368 if( pxUnblockedCRCB->uxPriority >= pxCurrentCoRoutine->uxPriority ) 369 { 370 xReturn = pdTRUE; 371 } 372 else 373 { 374 xReturn = pdFALSE; 375 } 376 377 traceRETURN_xCoRoutineRemoveFromEventList( xReturn ); 378 379 return xReturn; 380 } 381 382 #endif /* configUSE_CO_ROUTINES == 0 */ 383
