1 /* 2 * FreeRTOS Kernel V11.1.0 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 if 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 = ( UBaseType_t ) 0U; 56 static TickType_t xCoRoutineTickCount = ( TickType_t ) 0U; 57 static TickType_t xLastTickCount = ( TickType_t ) 0U; 58 static TickType_t xPassedTicks = ( TickType_t ) 0U; 59 60 /* The initial state of the co-routine when it is created. */ 61 #define corINITIAL_STATE ( 0 ) 62 63 /* 64 * Place the co-routine represented by pxCRCB into the appropriate ready queue 65 * for the priority. It is inserted at the end of the list. 66 * 67 * This macro accesses the co-routine ready lists and therefore must not be 68 * used from within an ISR. 69 */ 70 #define prvAddCoRoutineToReadyQueue( pxCRCB ) \ 71 do { \ 72 if( ( pxCRCB )->uxPriority > uxTopCoRoutineReadyPriority ) \ 73 { \ 74 uxTopCoRoutineReadyPriority = ( pxCRCB )->uxPriority; \ 75 } \ 76 vListInsertEnd( ( List_t * ) &( pxReadyCoRoutineLists[ ( pxCRCB )->uxPriority ] ), &( ( pxCRCB )->xGenericListItem ) ); \ 77 } while( 0 ) 78 79 /* 80 * Utility to ready all the lists used by the scheduler. This is called 81 * automatically upon the creation of the first co-routine. 82 */ 83 static void prvInitialiseCoRoutineLists( void ); 84 85 /* 86 * Co-routines that are readied by an interrupt cannot be placed directly into 87 * the ready lists (there is no mutual exclusion). Instead they are placed in 88 * in the pending ready list in order that they can later be moved to the ready 89 * list by the co-routine scheduler. 90 */ 91 static void prvCheckPendingReadyList( void ); 92 93 /* 94 * Macro that looks at the list of co-routines that are currently delayed to 95 * see if any require waking. 96 * 97 * Co-routines are stored in the queue in the order of their wake time - 98 * meaning once one co-routine has been found whose timer has not expired 99 * we need not look any further down the list. 100 */ 101 static void prvCheckDelayedList( void ); 102 103 /*-----------------------------------------------------------*/ 104 xCoRoutineCreate(crCOROUTINE_CODE pxCoRoutineCode,UBaseType_t uxPriority,UBaseType_t uxIndex)105 BaseType_t xCoRoutineCreate( crCOROUTINE_CODE pxCoRoutineCode, 106 UBaseType_t uxPriority, 107 UBaseType_t uxIndex ) 108 { 109 BaseType_t xReturn; 110 CRCB_t * pxCoRoutine; 111 112 traceENTER_xCoRoutineCreate( pxCoRoutineCode, uxPriority, uxIndex ); 113 114 /* Allocate the memory that will store the co-routine control block. */ 115 /* MISRA Ref 11.5.1 [Malloc memory assignment] */ 116 /* More details at: https://github.com/FreeRTOS/FreeRTOS-Kernel/blob/main/MISRA.md#rule-115 */ 117 /* coverity[misra_c_2012_rule_11_5_violation] */ 118 pxCoRoutine = ( CRCB_t * ) pvPortMalloc( sizeof( CRCB_t ) ); 119 120 if( pxCoRoutine ) 121 { 122 /* If pxCurrentCoRoutine is NULL then this is the first co-routine to 123 * be created and the co-routine data structures need initialising. */ 124 if( pxCurrentCoRoutine == NULL ) 125 { 126 pxCurrentCoRoutine = pxCoRoutine; 127 prvInitialiseCoRoutineLists(); 128 } 129 130 /* Check the priority is within limits. */ 131 if( uxPriority >= configMAX_CO_ROUTINE_PRIORITIES ) 132 { 133 uxPriority = configMAX_CO_ROUTINE_PRIORITIES - 1; 134 } 135 136 /* Fill out the co-routine control block from the function parameters. */ 137 pxCoRoutine->uxState = corINITIAL_STATE; 138 pxCoRoutine->uxPriority = uxPriority; 139 pxCoRoutine->uxIndex = uxIndex; 140 pxCoRoutine->pxCoRoutineFunction = pxCoRoutineCode; 141 142 /* Initialise all the other co-routine control block parameters. */ 143 vListInitialiseItem( &( pxCoRoutine->xGenericListItem ) ); 144 vListInitialiseItem( &( pxCoRoutine->xEventListItem ) ); 145 146 /* Set the co-routine control block as a link back from the ListItem_t. 147 * This is so we can get back to the containing CRCB from a generic item 148 * in a list. */ 149 listSET_LIST_ITEM_OWNER( &( pxCoRoutine->xGenericListItem ), pxCoRoutine ); 150 listSET_LIST_ITEM_OWNER( &( pxCoRoutine->xEventListItem ), pxCoRoutine ); 151 152 /* Event lists are always in priority order. */ 153 listSET_LIST_ITEM_VALUE( &( pxCoRoutine->xEventListItem ), ( ( TickType_t ) configMAX_CO_ROUTINE_PRIORITIES - ( TickType_t ) uxPriority ) ); 154 155 /* Now the co-routine has been initialised it can be added to the ready 156 * list at the correct priority. */ 157 prvAddCoRoutineToReadyQueue( pxCoRoutine ); 158 159 xReturn = pdPASS; 160 } 161 else 162 { 163 xReturn = errCOULD_NOT_ALLOCATE_REQUIRED_MEMORY; 164 } 165 166 traceRETURN_xCoRoutineCreate( xReturn ); 167 168 return xReturn; 169 } 170 /*-----------------------------------------------------------*/ 171 vCoRoutineAddToDelayedList(TickType_t xTicksToDelay,List_t * pxEventList)172 void vCoRoutineAddToDelayedList( TickType_t xTicksToDelay, 173 List_t * pxEventList ) 174 { 175 TickType_t xTimeToWake; 176 177 traceENTER_vCoRoutineAddToDelayedList( xTicksToDelay, pxEventList ); 178 179 /* Calculate the time to wake - this may overflow but this is 180 * not a problem. */ 181 xTimeToWake = xCoRoutineTickCount + xTicksToDelay; 182 183 /* We must remove ourselves from the ready list before adding 184 * ourselves to the blocked list as the same list item is used for 185 * both lists. */ 186 ( void ) uxListRemove( ( ListItem_t * ) &( pxCurrentCoRoutine->xGenericListItem ) ); 187 188 /* The list item will be inserted in wake time order. */ 189 listSET_LIST_ITEM_VALUE( &( pxCurrentCoRoutine->xGenericListItem ), xTimeToWake ); 190 191 if( xTimeToWake < xCoRoutineTickCount ) 192 { 193 /* Wake time has overflowed. Place this item in the 194 * overflow list. */ 195 vListInsert( ( List_t * ) pxOverflowDelayedCoRoutineList, ( ListItem_t * ) &( pxCurrentCoRoutine->xGenericListItem ) ); 196 } 197 else 198 { 199 /* The wake time has not overflowed, so we can use the 200 * current block list. */ 201 vListInsert( ( List_t * ) pxDelayedCoRoutineList, ( ListItem_t * ) &( pxCurrentCoRoutine->xGenericListItem ) ); 202 } 203 204 if( pxEventList ) 205 { 206 /* Also add the co-routine to an event list. If this is done then the 207 * function must be called with interrupts disabled. */ 208 vListInsert( pxEventList, &( pxCurrentCoRoutine->xEventListItem ) ); 209 } 210 211 traceRETURN_vCoRoutineAddToDelayedList(); 212 } 213 /*-----------------------------------------------------------*/ 214 prvCheckPendingReadyList(void)215 static void prvCheckPendingReadyList( void ) 216 { 217 /* Are there any co-routines waiting to get moved to the ready list? These 218 * are co-routines that have been readied by an ISR. The ISR cannot access 219 * the ready lists itself. */ 220 while( listLIST_IS_EMPTY( &xPendingReadyCoRoutineList ) == pdFALSE ) 221 { 222 CRCB_t * pxUnblockedCRCB; 223 224 /* The pending ready list can be accessed by an ISR. */ 225 portDISABLE_INTERRUPTS(); 226 { 227 pxUnblockedCRCB = ( CRCB_t * ) listGET_OWNER_OF_HEAD_ENTRY( ( &xPendingReadyCoRoutineList ) ); 228 ( void ) uxListRemove( &( pxUnblockedCRCB->xEventListItem ) ); 229 } 230 portENABLE_INTERRUPTS(); 231 232 ( void ) uxListRemove( &( pxUnblockedCRCB->xGenericListItem ) ); 233 prvAddCoRoutineToReadyQueue( pxUnblockedCRCB ); 234 } 235 } 236 /*-----------------------------------------------------------*/ 237 prvCheckDelayedList(void)238 static void prvCheckDelayedList( void ) 239 { 240 CRCB_t * pxCRCB; 241 242 xPassedTicks = xTaskGetTickCount() - xLastTickCount; 243 244 while( xPassedTicks ) 245 { 246 xCoRoutineTickCount++; 247 xPassedTicks--; 248 249 /* If the tick count has overflowed we need to swap the ready lists. */ 250 if( xCoRoutineTickCount == 0 ) 251 { 252 List_t * pxTemp; 253 254 /* Tick count has overflowed so we need to swap the delay lists. If there are 255 * any items in pxDelayedCoRoutineList here then there is an error! */ 256 pxTemp = pxDelayedCoRoutineList; 257 pxDelayedCoRoutineList = pxOverflowDelayedCoRoutineList; 258 pxOverflowDelayedCoRoutineList = pxTemp; 259 } 260 261 /* See if this tick has made a timeout expire. */ 262 while( listLIST_IS_EMPTY( pxDelayedCoRoutineList ) == pdFALSE ) 263 { 264 pxCRCB = ( CRCB_t * ) listGET_OWNER_OF_HEAD_ENTRY( pxDelayedCoRoutineList ); 265 266 if( xCoRoutineTickCount < listGET_LIST_ITEM_VALUE( &( pxCRCB->xGenericListItem ) ) ) 267 { 268 /* Timeout not yet expired. */ 269 break; 270 } 271 272 portDISABLE_INTERRUPTS(); 273 { 274 /* The event could have occurred just before this critical 275 * section. If this is the case then the generic list item will 276 * have been moved to the pending ready list and the following 277 * line is still valid. Also the pvContainer parameter will have 278 * been set to NULL so the following lines are also valid. */ 279 ( void ) uxListRemove( &( pxCRCB->xGenericListItem ) ); 280 281 /* Is the co-routine waiting on an event also? */ 282 if( pxCRCB->xEventListItem.pxContainer ) 283 { 284 ( void ) uxListRemove( &( pxCRCB->xEventListItem ) ); 285 } 286 } 287 portENABLE_INTERRUPTS(); 288 289 prvAddCoRoutineToReadyQueue( pxCRCB ); 290 } 291 } 292 293 xLastTickCount = xCoRoutineTickCount; 294 } 295 /*-----------------------------------------------------------*/ 296 vCoRoutineSchedule(void)297 void vCoRoutineSchedule( void ) 298 { 299 traceENTER_vCoRoutineSchedule(); 300 301 /* Only run a co-routine after prvInitialiseCoRoutineLists() has been 302 * called. prvInitialiseCoRoutineLists() is called automatically when a 303 * co-routine is created. */ 304 if( pxDelayedCoRoutineList != NULL ) 305 { 306 /* See if any co-routines readied by events need moving to the ready lists. */ 307 prvCheckPendingReadyList(); 308 309 /* See if any delayed co-routines have timed out. */ 310 prvCheckDelayedList(); 311 312 /* Find the highest priority queue that contains ready co-routines. */ 313 while( listLIST_IS_EMPTY( &( pxReadyCoRoutineLists[ uxTopCoRoutineReadyPriority ] ) ) ) 314 { 315 if( uxTopCoRoutineReadyPriority == 0 ) 316 { 317 /* No more co-routines to check. */ 318 return; 319 } 320 321 --uxTopCoRoutineReadyPriority; 322 } 323 324 /* listGET_OWNER_OF_NEXT_ENTRY walks through the list, so the co-routines 325 * of the same priority get an equal share of the processor time. */ 326 listGET_OWNER_OF_NEXT_ENTRY( pxCurrentCoRoutine, &( pxReadyCoRoutineLists[ uxTopCoRoutineReadyPriority ] ) ); 327 328 /* Call the co-routine. */ 329 ( pxCurrentCoRoutine->pxCoRoutineFunction )( pxCurrentCoRoutine, pxCurrentCoRoutine->uxIndex ); 330 } 331 332 traceRETURN_vCoRoutineSchedule(); 333 } 334 /*-----------------------------------------------------------*/ 335 prvInitialiseCoRoutineLists(void)336 static void prvInitialiseCoRoutineLists( void ) 337 { 338 UBaseType_t uxPriority; 339 340 for( uxPriority = 0; uxPriority < configMAX_CO_ROUTINE_PRIORITIES; uxPriority++ ) 341 { 342 vListInitialise( ( List_t * ) &( pxReadyCoRoutineLists[ uxPriority ] ) ); 343 } 344 345 vListInitialise( ( List_t * ) &xDelayedCoRoutineList1 ); 346 vListInitialise( ( List_t * ) &xDelayedCoRoutineList2 ); 347 vListInitialise( ( List_t * ) &xPendingReadyCoRoutineList ); 348 349 /* Start with pxDelayedCoRoutineList using list1 and the 350 * pxOverflowDelayedCoRoutineList using list2. */ 351 pxDelayedCoRoutineList = &xDelayedCoRoutineList1; 352 pxOverflowDelayedCoRoutineList = &xDelayedCoRoutineList2; 353 } 354 /*-----------------------------------------------------------*/ 355 xCoRoutineRemoveFromEventList(const List_t * pxEventList)356 BaseType_t xCoRoutineRemoveFromEventList( const List_t * pxEventList ) 357 { 358 CRCB_t * pxUnblockedCRCB; 359 BaseType_t xReturn; 360 361 traceENTER_xCoRoutineRemoveFromEventList( pxEventList ); 362 363 /* This function is called from within an interrupt. It can only access 364 * event lists and the pending ready list. This function assumes that a 365 * check has already been made to ensure pxEventList is not empty. */ 366 pxUnblockedCRCB = ( CRCB_t * ) listGET_OWNER_OF_HEAD_ENTRY( pxEventList ); 367 ( void ) uxListRemove( &( pxUnblockedCRCB->xEventListItem ) ); 368 vListInsertEnd( ( List_t * ) &( xPendingReadyCoRoutineList ), &( pxUnblockedCRCB->xEventListItem ) ); 369 370 if( pxUnblockedCRCB->uxPriority >= pxCurrentCoRoutine->uxPriority ) 371 { 372 xReturn = pdTRUE; 373 } 374 else 375 { 376 xReturn = pdFALSE; 377 } 378 379 traceRETURN_xCoRoutineRemoveFromEventList( xReturn ); 380 381 return xReturn; 382 } 383 /*-----------------------------------------------------------*/ 384 385 /* 386 * Reset state in this file. This state is normally initialized at start up. 387 * This function must be called by the application before restarting the 388 * scheduler. 389 */ vCoRoutineResetState(void)390 void vCoRoutineResetState( void ) 391 { 392 /* Lists for ready and blocked co-routines. */ 393 pxDelayedCoRoutineList = NULL; 394 pxOverflowDelayedCoRoutineList = NULL; 395 396 /* Other file private variables. */ 397 pxCurrentCoRoutine = NULL; 398 uxTopCoRoutineReadyPriority = ( UBaseType_t ) 0U; 399 xCoRoutineTickCount = ( TickType_t ) 0U; 400 xLastTickCount = ( TickType_t ) 0U; 401 xPassedTicks = ( TickType_t ) 0U; 402 } 403 /*-----------------------------------------------------------*/ 404 405 #endif /* configUSE_CO_ROUTINES == 0 */ 406
