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   1 /*\r
   2         FreeRTOS.org V4.8.0 - Copyright (C) 2003-2008 Richard Barry.\r
   3 \r
   4         This file is part of the FreeRTOS.org distribution.\r
   5 \r
   6         FreeRTOS.org is free software; you can redistribute it and/or modify\r
   7         it under the terms of the GNU General Public License as published by\r
   8         the Free Software Foundation; either version 2 of the License, or\r
   9         (at your option) any later version.\r
  10 \r
  11         FreeRTOS.org is distributed in the hope that it will be useful,\r
  12         but WITHOUT ANY WARRANTY; without even the implied warranty of\r
  13         MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the\r
  14         GNU General Public License for more details.\r
  15 \r
  16         You should have received a copy of the GNU General Public License\r
  17         along with FreeRTOS.org; if not, write to the Free Software\r
  18         Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA\r
  19 \r
  20         A special exception to the GPL can be applied should you wish to distribute\r
  21         a combined work that includes FreeRTOS.org, without being obliged to provide\r
  22         the source code for any proprietary components.  See the licensing section\r
  23         of http://www.FreeRTOS.org for full details of how and when the exception\r
  24         can be applied.\r
  25 \r
  26         ***************************************************************************\r
  27         ***************************************************************************\r
  28         *                                                                                                                                                 *\r
  29         * SAVE TIME AND MONEY!  Why not get us to quote to get FreeRTOS.org               *\r
  30         * running on your hardware - or even write all or part of your application*\r
  31         * for you?  See http://www.OpenRTOS.com for details.                                      *\r
  32         *                                                                                                                                                 *\r
  33         ***************************************************************************\r
  34         ***************************************************************************\r
  35 \r
  36         Please ensure to read the configuration and relevant port sections of the\r
  37         online documentation.\r
  38 \r
  39         http://www.FreeRTOS.org - Documentation, latest information, license and \r
  40         contact details.\r
  41 \r
  42         http://www.SafeRTOS.com - A version that is certified for use in safety \r
  43         critical systems.\r
  44 \r
  45         http://www.OpenRTOS.com - Commercial support, development, porting, \r
  46         licensing and training services.\r
  47 */\r
  48 \r
  49 \r
  50 #include <stdio.h>\r
  51 #include <stdlib.h>\r
  52 #include <string.h>\r
  53 \r
  54 #include "FreeRTOS.h"\r
  55 #include "task.h"\r
  56 \r
  57 /*\r
  58  * Macro to define the amount of stack available to the idle task.\r
  59  */\r
  60 #define tskIDLE_STACK_SIZE      configMINIMAL_STACK_SIZE\r
  61 \r
  62 \r
  63 /*\r
  64  * Default a definitions for backwards compatibility with old\r
  65  * portmacro.h files.\r
  66  */\r
  67 #ifndef configMAX_TASK_NAME_LEN\r
  68         #define configMAX_TASK_NAME_LEN 16\r
  69 #endif\r
  70 \r
  71 #ifndef configIDLE_SHOULD_YIELD\r
  72         #define configIDLE_SHOULD_YIELD         1\r
  73 #endif\r
  74 \r
  75 #if configMAX_TASK_NAME_LEN < 1\r
  76         #undef configMAX_TASK_NAME_LEN\r
  77         #define configMAX_TASK_NAME_LEN 1\r
  78 #endif\r
  79 \r
  80 #ifndef INCLUDE_xTaskResumeFromISR\r
  81         #define INCLUDE_xTaskResumeFromISR 1\r
  82 #endif\r
  83 \r
  84 #ifndef INCLUDE_xTaskGetSchedulerState\r
  85         #define INCLUDE_xTaskGetSchedulerState 0\r
  86 #endif\r
  87 \r
  88 /*\r
  89  * Task control block.  A task control block (TCB) is allocated to each task,\r
  90  * and stores the context of the task.\r
  91  */\r
  92 typedef struct tskTaskControlBlock\r
  93 {\r
  94         volatile portSTACK_TYPE *pxTopOfStack;          /*< Points to the location of the last item placed on the tasks stack.  THIS MUST BE THE FIRST MEMBER OF THE STRUCT. */\r
  95         xListItem                               xGenericListItem;       /*< List item used to place the TCB in ready and blocked queues. */\r
  96         xListItem                               xEventListItem;         /*< List item used to place the TCB in event lists. */\r
  97         unsigned portBASE_TYPE  uxPriority;                     /*< The priority of the task where 0 is the lowest priority. */\r
  98         portSTACK_TYPE                  *pxStack;                       /*< Points to the start of the stack. */\r
  99         signed portCHAR                 pcTaskName[ configMAX_TASK_NAME_LEN ];/*< Descriptive name given to the task when created.  Facilitates debugging only. */\r
 100 \r
 101         #if ( portCRITICAL_NESTING_IN_TCB == 1 )\r
 102                 unsigned portBASE_TYPE uxCriticalNesting;\r
 103         #endif\r
 104 \r
 105         #if ( configUSE_TRACE_FACILITY == 1 )\r
 106                 unsigned portBASE_TYPE  uxTCBNumber;            /*< This is used for tracing the scheduler and making debugging easier only. */\r
 107         #endif  \r
 108                 \r
 109         #if ( configUSE_MUTEXES == 1 )\r
 110                 unsigned portBASE_TYPE uxBasePriority;\r
 111         #endif\r
 112                 \r
 113 } tskTCB;\r
 114 \r
 115 /*lint -e956 */\r
 116 \r
 117 tskTCB * volatile pxCurrentTCB = NULL;                                  \r
 118 \r
 119 /* Lists for ready and blocked tasks. --------------------*/\r
 120 \r
 121 static xList pxReadyTasksLists[ configMAX_PRIORITIES ]; /*< Prioritised ready tasks. */\r
 122 static xList xDelayedTaskList1;                                                 /*< Delayed tasks. */\r
 123 static xList xDelayedTaskList2;                                                 /*< Delayed tasks (two lists are used - one for delays that have overflowed the current tick count. */\r
 124 static xList * volatile pxDelayedTaskList;                              /*< Points to the delayed task list currently being used. */\r
 125 static xList * volatile pxOverflowDelayedTaskList;              /*< Points to the delayed task list currently being used to hold tasks that have overflowed the current tick count. */\r
 126 static xList xPendingReadyList;                                                 /*< Tasks that have been readied while the scheduler was suspended.  They will be moved to the ready queue when the scheduler is resumed. */\r
 127 \r
 128 #if ( INCLUDE_vTaskDelete == 1 )\r
 129 \r
 130         static volatile xList xTasksWaitingTermination;         /*< Tasks that have been deleted - but the their memory not yet freed. */\r
 131         static volatile unsigned portBASE_TYPE uxTasksDeleted = ( unsigned portBASE_TYPE ) 0;\r
 132 \r
 133 #endif\r
 134 \r
 135 #if ( INCLUDE_vTaskSuspend == 1 )\r
 136 \r
 137         static xList xSuspendedTaskList;                                        /*< Tasks that are currently suspended. */\r
 138 \r
 139 #endif\r
 140 \r
 141 /* File private variables. --------------------------------*/\r
 142 static volatile unsigned portBASE_TYPE uxCurrentNumberOfTasks   = ( unsigned portBASE_TYPE ) 0;\r
 143 static volatile portTickType xTickCount                                                 = ( portTickType ) 0;\r
 144 static unsigned portBASE_TYPE uxTopUsedPriority                                 = tskIDLE_PRIORITY;\r
 145 static volatile unsigned portBASE_TYPE uxTopReadyPriority               = tskIDLE_PRIORITY;\r
 146 static volatile signed portBASE_TYPE xSchedulerRunning                  = pdFALSE;\r
 147 static volatile unsigned portBASE_TYPE uxSchedulerSuspended             = ( unsigned portBASE_TYPE ) pdFALSE;\r
 148 static volatile unsigned portBASE_TYPE uxMissedTicks                    = ( unsigned portBASE_TYPE ) 0;\r
 149 static volatile portBASE_TYPE xMissedYield                                              = ( portBASE_TYPE ) pdFALSE;\r
 150 static volatile portBASE_TYPE xNumOfOverflows                                   = ( portBASE_TYPE ) 0;\r
 151 /* Debugging and trace facilities private variables and macros. ------------*/\r
 152 \r
 153 /*\r
 154  * The value used to fill the stack of a task when the task is created.  This\r
 155  * is used purely for checking the high water mark for tasks.\r
 156  */\r
 157 #define tskSTACK_FILL_BYTE      ( 0xa5 )\r
 158 \r
 159 /*\r
 160  * Macros used by vListTask to indicate which state a task is in.\r
 161  */\r
 162 #define tskBLOCKED_CHAR         ( ( signed portCHAR ) 'B' )\r
 163 #define tskREADY_CHAR           ( ( signed portCHAR ) 'R' )\r
 164 #define tskDELETED_CHAR         ( ( signed portCHAR ) 'D' )\r
 165 #define tskSUSPENDED_CHAR       ( ( signed portCHAR ) 'S' )\r
 166 \r
 167 /*\r
 168  * Macros and private variables used by the trace facility.\r
 169  */\r
 170 #if ( configUSE_TRACE_FACILITY == 1 )\r
 171 \r
 172         #define tskSIZE_OF_EACH_TRACE_LINE                      ( ( unsigned portLONG ) ( sizeof( unsigned portLONG ) + sizeof( unsigned portLONG ) ) )\r
 173         static volatile signed portCHAR * volatile pcTraceBuffer;\r
 174         static signed portCHAR *pcTraceBufferStart;\r
 175         static signed portCHAR *pcTraceBufferEnd;\r
 176         static signed portBASE_TYPE xTracing = pdFALSE;\r
 177 \r
 178 #endif\r
 179 \r
 180 /*-----------------------------------------------------------*/\r
 181 \r
 182 /*\r
 183  * Macro that writes a trace of scheduler activity to a buffer.  This trace\r
 184  * shows which task is running when and is very useful as a debugging tool.\r
 185  * As this macro is called each context switch it is a good idea to undefine\r
 186  * it if not using the facility.\r
 187  */\r
 188 #if ( configUSE_TRACE_FACILITY == 1 )\r
 189 \r
 190         #define vWriteTraceToBuffer()                                                                                                                                   \\r
 191         {                                                                                                                                                                                               \\r
 192                 if( xTracing )                                                                                                                                                          \\r
 193                 {                                                                                                                                                                                       \\r
 194                         static unsigned portBASE_TYPE uxPreviousTask = 255;                                                                             \\r
 195                                                                                                                                                                                                         \\r
 196                         if( uxPreviousTask != pxCurrentTCB->uxTCBNumber )                                                                               \\r
 197                         {                                                                                                                                                                               \\r
 198                                 if( ( pcTraceBuffer + tskSIZE_OF_EACH_TRACE_LINE ) < pcTraceBufferEnd )                         \\r
 199                                 {                                                                                                                                                                       \\r
 200                                         uxPreviousTask = pxCurrentTCB->uxTCBNumber;                                                                             \\r
 201                                         *( unsigned portLONG * ) pcTraceBuffer = ( unsigned portLONG ) xTickCount;              \\r
 202                                         pcTraceBuffer += sizeof( unsigned portLONG );                                                                   \\r
 203                                         *( unsigned portLONG * ) pcTraceBuffer = ( unsigned portLONG ) uxPreviousTask;  \\r
 204                                         pcTraceBuffer += sizeof( unsigned portLONG );                                                                   \\r
 205                                 }                                                                                                                                                                       \\r
 206                                 else                                                                                                                                                            \\r
 207                                 {                                                                                                                                                                       \\r
 208                                         xTracing = pdFALSE;                                                                                                                             \\r
 209                                 }                                                                                                                                                                       \\r
 210                         }                                                                                                                                                                               \\r
 211                 }                                                                                                                                                                                       \\r
 212         }\r
 213 \r
 214 #else\r
 215 \r
 216         #define vWriteTraceToBuffer()\r
 217 \r
 218 #endif\r
 219 /*-----------------------------------------------------------*/\r
 220 \r
 221 /*\r
 222  * Place the task represented by pxTCB into the appropriate ready queue for\r
 223  * the task.  It is inserted at the end of the list.  One quirk of this is\r
 224  * that if the task being inserted is at the same priority as the currently\r
 225  * executing task, then it will only be rescheduled after the currently\r
 226  * executing task has been rescheduled.\r
 227  */\r
 228 #define prvAddTaskToReadyQueue( pxTCB )                                                                                                                                                 \\r
 229 {                                                                                                                                                                                                                               \\r
 230         if( pxTCB->uxPriority > uxTopReadyPriority )                                                                                                                            \\r
 231         {                                                                                                                                                                                                                       \\r
 232                 uxTopReadyPriority = pxTCB->uxPriority;                                                                                                                                 \\r
 233         }                                                                                                                                                                                                                       \\r
 234         vListInsertEnd( ( xList * ) &( pxReadyTasksLists[ pxTCB->uxPriority ] ), &( pxTCB->xGenericListItem ) );        \\r
 235 }\r
 236 /*-----------------------------------------------------------*/         \r
 237 \r
 238 /*\r
 239  * Macro that looks at the list of tasks that are currently delayed to see if\r
 240  * any require waking.\r
 241  *\r
 242  * Tasks are stored in the queue in the order of their wake time - meaning\r
 243  * once one tasks has been found whose timer has not expired we need not look\r
 244  * any further down the list.\r
 245  */\r
 246 #define prvCheckDelayedTasks()                                                                                                                                                                          \\r
 247 {                                                                                                                                                                                                                                       \\r
 248 register tskTCB *pxTCB;                                                                                                                                                                                         \\r
 249                                                                                                                                                                                                                                         \\r
 250         while( ( pxTCB = ( tskTCB * ) listGET_OWNER_OF_HEAD_ENTRY( pxDelayedTaskList ) ) != NULL )                                              \\r
 251         {                                                                                                                                                                                                                               \\r
 252                 if( xTickCount < listGET_LIST_ITEM_VALUE( &( pxTCB->xGenericListItem ) ) )                                                                      \\r
 253                 {                                                                                                                                                                                                                       \\r
 254                         break;                                                                                                                                                                                                  \\r
 255                 }                                                                                                                                                                                                                       \\r
 256                 vListRemove( &( pxTCB->xGenericListItem ) );                                                                                                                            \\r
 257                 /* Is the task waiting on an event also? */                                                                                                                                     \\r
 258                 if( pxTCB->xEventListItem.pvContainer )                                                                                                                                         \\r
 259                 {                                                                                                                                                                                                                       \\r
 260                         vListRemove( &( pxTCB->xEventListItem ) );                                                                                                                              \\r
 261                 }                                                                                                                                                                                                                       \\r
 262                 prvAddTaskToReadyQueue( pxTCB );                                                                                                                                                        \\r
 263         }                                                                                                                                                                                                                               \\r
 264 }\r
 265 /*-----------------------------------------------------------*/\r
 266 \r
 267 /*\r
 268  * Call the stack overflow hook function if the stack of the task being swapped\r
 269  * out is currently overflowed, or looks like it might have overflowed in the\r
 270  * past.\r
 271  *\r
 272  * Setting configCHECK_FOR_STACK_OVERFLOW to 1 will cause the macro to check\r
 273  * the current stack state only - comparing the current top of stack value to\r
 274  * the stack limit.  Setting configCHECK_FOR_STACK_OVERFLOW to greater than 1\r
 275  * will also cause the last few stack bytes to be checked to ensure the value\r
 276  * to which the bytes were set when the task was created have not been \r
 277  * overwritten.  Note this second test does not guarantee that an overflowed\r
 278  * stack will always be recognised.\r
 279  */\r
 280 \r
 281 #if( configCHECK_FOR_STACK_OVERFLOW == 0 )\r
 282 \r
 283         /* FreeRTOSConfig.h is not set to check for stack overflows. */\r
 284         #define taskCHECK_FOR_STACK_OVERFLOW()\r
 285 \r
 286 #endif /* configCHECK_FOR_STACK_OVERFLOW == 0 */\r
 287 \r
 288 #if( ( configCHECK_FOR_STACK_OVERFLOW > 0 ) && ( portSTACK_GROWTH >= 0 ) )\r
 289 \r
 290         /* This is an invalid setting. */\r
 291         #error configCHECK_FOR_STACK_OVERFLOW can only be set to a non zero value on architectures where the stack grows down from high memory.\r
 292 \r
 293 #endif /* ( configCHECK_FOR_STACK_OVERFLOW > 0 ) && ( portSTACK_GROWTH >= 0 ) */\r
 294 \r
 295 #if( configCHECK_FOR_STACK_OVERFLOW == 1 )\r
 296 \r
 297         /* Only the current stack state is to be checked. */\r
 298         #define taskCHECK_FOR_STACK_OVERFLOW()                                                                                                                          \\r
 299         {                                                                                                                                                                                                       \\r
 300         extern void vApplicationStackOverflowHook( xTaskHandle *pxTask, signed portCHAR *pcTaskName );          \\r
 301                                                                                                                                                                                                                 \\r
 302                 /* Is the currently saved stack pointer within the stack limit? */                                                              \\r
 303                 if( pxCurrentTCB->pxTopOfStack <= pxCurrentTCB->pxStack )                                                                               \\r
 304                 {                                                                                                                                                                                               \\r
 305                         vApplicationStackOverflowHook( ( xTaskHandle ) pxCurrentTCB, pxCurrentTCB->pcTaskName );        \\r
 306                 }                                                                                                                                                                                               \\r
 307         }\r
 308 \r
 309 #endif /* configCHECK_FOR_STACK_OVERFLOW == 1 */\r
 310 \r
 311 #if( configCHECK_FOR_STACK_OVERFLOW > 1 )\r
 312 \r
 313         /* Both the current statck state and the stack fill bytes are to be checked. */\r
 314         #define taskCHECK_FOR_STACK_OVERFLOW()                                                                                                                                                                                                                  \\r
 315         {                                                                                                                                                                                                                                                                                               \\r
 316         extern void vApplicationStackOverflowHook( xTaskHandle *pxTask, signed portCHAR *pcTaskName );                                                                                                  \\r
 317         static const unsigned portCHAR ucExpectedStackBytes[] = {       tskSTACK_FILL_BYTE, tskSTACK_FILL_BYTE, tskSTACK_FILL_BYTE, tskSTACK_FILL_BYTE,         \\r
 318                                                                                                                                 tskSTACK_FILL_BYTE, tskSTACK_FILL_BYTE, tskSTACK_FILL_BYTE, tskSTACK_FILL_BYTE,         \\r
 319                                                                                                                                 tskSTACK_FILL_BYTE, tskSTACK_FILL_BYTE, tskSTACK_FILL_BYTE, tskSTACK_FILL_BYTE,         \\r
 320                                                                                                                                 tskSTACK_FILL_BYTE, tskSTACK_FILL_BYTE, tskSTACK_FILL_BYTE, tskSTACK_FILL_BYTE,         \\r
 321                                                                                                                                 tskSTACK_FILL_BYTE, tskSTACK_FILL_BYTE, tskSTACK_FILL_BYTE, tskSTACK_FILL_BYTE };       \\r
 322                                                                                                                                                                                                                                                                                                         \\r
 323                 /* Is the currently saved stack pointer within the stack limit? */                                                                                                                                                      \\r
 324                 if( pxCurrentTCB->pxTopOfStack <= pxCurrentTCB->pxStack )                                                                                                                                                                       \\r
 325                 {                                                                                                                                                                                                                                                                                       \\r
 326                         vApplicationStackOverflowHook( ( xTaskHandle ) pxCurrentTCB, pxCurrentTCB->pcTaskName );                                                                                                \\r
 327                 }                                                                                                                                                                                                                                                                                       \\r
 328                                                                                                                                                                                                                                                                                                         \\r
 329                 /* Has the extremity of the task stack ever been written over? */                                                                                                                                                       \\r
 330                 if( memcmp( ( void * ) pxCurrentTCB->pxStack, ( void * ) ucExpectedStackBytes, sizeof( ucExpectedStackBytes ) ) != 0 )                                          \\r
 331                 {                                                                                                                                                                                                                                                                                       \\r
 332                         vApplicationStackOverflowHook( ( xTaskHandle ) pxCurrentTCB, pxCurrentTCB->pcTaskName );                                                                                                \\r
 333                 }                                                                                                                                                                                                                                                                                       \\r
 334         }\r
 335 \r
 336 #endif /* #if( configCHECK_FOR_STACK_OVERFLOW > 1 ) */\r
 337 \r
 338 /*-----------------------------------------------------------*/\r
 339 \r
 340 /*\r
 341  * Several functions take an xTaskHandle parameter that can optionally be NULL,\r
 342  * where NULL is used to indicate that the handle of the currently executing\r
 343  * task should be used in place of the parameter.  This macro simply checks to\r
 344  * see if the parameter is NULL and returns a pointer to the appropriate TCB.\r
 345  */\r
 346 #define prvGetTCBFromHandle( pxHandle ) ( ( pxHandle == NULL ) ? ( tskTCB * ) pxCurrentTCB : ( tskTCB * ) pxHandle )\r
 347 \r
 348 \r
 349 /* File private functions. --------------------------------*/\r
 350 \r
 351 /*\r
 352  * Utility to ready a TCB for a given task.  Mainly just copies the parameters\r
 353  * into the TCB structure.\r
 354  */\r
 355 static void prvInitialiseTCBVariables( tskTCB *pxTCB, const signed portCHAR * const pcName, unsigned portBASE_TYPE uxPriority );\r
 356 \r
 357 /*\r
 358  * Utility to ready all the lists used by the scheduler.  This is called\r
 359  * automatically upon the creation of the first task.\r
 360  */\r
 361 static void prvInitialiseTaskLists( void );\r
 362 \r
 363 /*\r
 364  * The idle task, which as all tasks is implemented as a never ending loop.\r
 365  * The idle task is automatically created and added to the ready lists upon\r
 366  * creation of the first user task.\r
 367  *\r
 368  * The portTASK_FUNCTION_PROTO() macro is used to allow port/compiler specific\r
 369  * language extensions.  The equivalent prototype for this function is:\r
 370  *\r
 371  * void prvIdleTask( void *pvParameters );\r
 372  *\r
 373  */\r
 374 static portTASK_FUNCTION_PROTO( prvIdleTask, pvParameters );\r
 375 \r
 376 /*\r
 377  * Utility to free all memory allocated by the scheduler to hold a TCB,\r
 378  * including the stack pointed to by the TCB.\r
 379  *\r
 380  * This does not free memory allocated by the task itself (i.e. memory\r
 381  * allocated by calls to pvPortMalloc from within the tasks application code).\r
 382  */\r
 383 #if ( ( INCLUDE_vTaskDelete == 1 ) || ( INCLUDE_vTaskCleanUpResources == 1 ) )\r
 384         static void prvDeleteTCB( tskTCB *pxTCB );\r
 385 #endif\r
 386 \r
 387 /*\r
 388  * Used only by the idle task.  This checks to see if anything has been placed\r
 389  * in the list of tasks waiting to be deleted.  If so the task is cleaned up\r
 390  * and its TCB deleted.\r
 391  */\r
 392 static void prvCheckTasksWaitingTermination( void );\r
 393 \r
 394 /*\r
 395  * Allocates memory from the heap for a TCB and associated stack.  Checks the\r
 396  * allocation was successful.\r
 397  */\r
 398 static tskTCB *prvAllocateTCBAndStack( unsigned portSHORT usStackDepth );\r
 399 \r
 400 /*\r
 401  * Called from vTaskList.  vListTasks details all the tasks currently under\r
 402  * control of the scheduler.  The tasks may be in one of a number of lists.\r
 403  * prvListTaskWithinSingleList accepts a list and details the tasks from\r
 404  * within just that list.\r
 405  *\r
 406  * THIS FUNCTION IS INTENDED FOR DEBUGGING ONLY, AND SHOULD NOT BE CALLED FROM\r
 407  * NORMAL APPLICATION CODE.\r
 408  */\r
 409 #if ( configUSE_TRACE_FACILITY == 1 )\r
 410 \r
 411         static void prvListTaskWithinSingleList( const signed portCHAR *pcWriteBuffer, xList *pxList, signed portCHAR cStatus );\r
 412 \r
 413 #endif\r
 414 \r
 415 /*\r
 416  * When a task is created, the stack of the task is filled with a known value.\r
 417  * This function determines the 'high water mark' of the task stack by\r
 418  * determining how much of the stack remains at the original preset value.\r
 419  */\r
 420 #if ( ( configUSE_TRACE_FACILITY == 1 ) || ( INCLUDE_uxTaskGetStackHighWaterMark == 1 ) )\r
 421 \r
 422         unsigned portSHORT usTaskCheckFreeStackSpace( const unsigned portCHAR * pucStackByte );\r
 423 \r
 424 #endif\r
 425 \r
 426 /*\r
 427  * Checks that a task being resumed (unsuspended) is actually in the Suspended\r
 428  * state.\r
 429  */\r
 430 #if ( INCLUDE_vTaskSuspend == 1 )\r
 431 \r
 432         static portBASE_TYPE prvIsTaskSuspended( const tskTCB * const pxTCB );  \r
 433 \r
 434 #endif\r
 435 \r
 436 /*lint +e956 */\r
 437 \r
 438 \r
 439 \r
 440 /*-----------------------------------------------------------\r
 441  * TASK CREATION API documented in task.h\r
 442  *----------------------------------------------------------*/\r
 443 \r
 444 signed portBASE_TYPE xTaskCreate( pdTASK_CODE pvTaskCode, const signed portCHAR * const pcName, unsigned portSHORT usStackDepth, void *pvParameters, unsigned portBASE_TYPE uxPriority, xTaskHandle *pxCreatedTask )\r
 445 {\r
 446 signed portBASE_TYPE xReturn;\r
 447 tskTCB * pxNewTCB;\r
 448 #if ( configUSE_TRACE_FACILITY == 1 )\r
 449         static unsigned portBASE_TYPE uxTaskNumber = 0; /*lint !e956 Static is deliberate - this is guarded before use. */\r
 450 #endif\r
 451 \r
 452         /* Allocate the memory required by the TCB and stack for the new task.\r
 453         checking that the allocation was successful. */\r
 454         pxNewTCB = prvAllocateTCBAndStack( usStackDepth );\r
 455 \r
 456         if( pxNewTCB != NULL )\r
 457         {               \r
 458                 portSTACK_TYPE *pxTopOfStack;\r
 459 \r
 460                 /* Setup the newly allocated TCB with the initial state of the task. */\r
 461                 prvInitialiseTCBVariables( pxNewTCB, pcName, uxPriority );\r
 462 \r
 463                 /* Calculate the top of stack address.  This depends on whether the\r
 464                 stack grows from high memory to low (as per the 80x86) or visa versa.\r
 465                 portSTACK_GROWTH is used to make the result positive or negative as\r
 466                 required by the port. */\r
 467                 #if portSTACK_GROWTH < 0\r
 468                 {\r
 469                         pxTopOfStack = pxNewTCB->pxStack + ( usStackDepth - 1 );\r
 470                 }\r
 471                 #else\r
 472                 {\r
 473                         pxTopOfStack = pxNewTCB->pxStack;       \r
 474                 }\r
 475                 #endif\r
 476 \r
 477                 /* Initialize the TCB stack to look as if the task was already running,\r
 478                 but had been interrupted by the scheduler.  The return address is set\r
 479                 to the start of the task function. Once the stack has been initialised\r
 480                 the     top of stack variable is updated. */\r
 481                 pxNewTCB->pxTopOfStack = pxPortInitialiseStack( pxTopOfStack, pvTaskCode, pvParameters );\r
 482 \r
 483                 /* We are going to manipulate the task queues to add this task to a\r
 484                 ready list, so must make sure no interrupts occur. */\r
 485                 portENTER_CRITICAL();\r
 486                 {\r
 487                         uxCurrentNumberOfTasks++;\r
 488                         if( uxCurrentNumberOfTasks == ( unsigned portBASE_TYPE ) 1 )\r
 489                         {\r
 490                                 /* As this is the first task it must also be the current task. */\r
 491                                 pxCurrentTCB =  pxNewTCB;\r
 492 \r
 493                                 /* This is the first task to be created so do the preliminary\r
 494                                 initialisation required.  We will not recover if this call\r
 495                                 fails, but we will report the failure. */\r
 496                                 prvInitialiseTaskLists();\r
 497                         }\r
 498                         else\r
 499                         {       \r
 500                                 /* If the scheduler is not already running, make this task the\r
 501                                 current task if it is the highest priority task to be created\r
 502                                 so far. */\r
 503                                 if( xSchedulerRunning == pdFALSE )\r
 504                                 {\r
 505                                         if( pxCurrentTCB->uxPriority <= uxPriority )\r
 506                                         {\r
 507                                                 pxCurrentTCB = pxNewTCB;        \r
 508                                         }\r
 509                                 }\r
 510                         }                               \r
 511 \r
 512                         /* Remember the top priority to make context switching faster.  Use\r
 513                         the priority in pxNewTCB as this has been capped to a valid value. */\r
 514                         if( pxNewTCB->uxPriority > uxTopUsedPriority )\r
 515                         {\r
 516                                 uxTopUsedPriority = pxNewTCB->uxPriority;\r
 517                         }\r
 518 \r
 519                         #if ( configUSE_TRACE_FACILITY == 1 )\r
 520                         {\r
 521                                 /* Add a counter into the TCB for tracing only. */\r
 522                                 pxNewTCB->uxTCBNumber = uxTaskNumber;\r
 523                                 uxTaskNumber++;\r
 524                         }\r
 525                         #endif\r
 526 \r
 527                         prvAddTaskToReadyQueue( pxNewTCB );\r
 528 \r
 529                         xReturn = pdPASS;\r
 530                         traceTASK_CREATE( pxNewTCB );\r
 531                 }\r
 532                 portEXIT_CRITICAL();\r
 533         }\r
 534         else\r
 535         {\r
 536                 xReturn = errCOULD_NOT_ALLOCATE_REQUIRED_MEMORY;\r
 537                 traceTASK_CREATE_FAILED( pxNewTCB );\r
 538         }\r
 539 \r
 540         if( xReturn == pdPASS )\r
 541         {\r
 542                 if( ( void * ) pxCreatedTask != NULL )\r
 543                 {\r
 544                         /* Pass the TCB out - in an anonymous way.  The calling function/\r
 545                         task can use this as a handle to delete the task later if\r
 546                         required.*/\r
 547                         *pxCreatedTask = ( xTaskHandle ) pxNewTCB;\r
 548                 }\r
 549 \r
 550                 if( xSchedulerRunning != pdFALSE )\r
 551                 {\r
 552                         /* If the created task is of a higher priority than the current task\r
 553                         then it should run now. */\r
 554                         if( pxCurrentTCB->uxPriority < uxPriority )\r
 555                         {\r
 556                                 taskYIELD();\r
 557                         }\r
 558                 }\r
 559         }\r
 560 \r
 561         return xReturn;\r
 562 }\r
 563 /*-----------------------------------------------------------*/\r
 564 \r
 565 #if ( INCLUDE_vTaskDelete == 1 )\r
 566 \r
 567         void vTaskDelete( xTaskHandle pxTaskToDelete )\r
 568         {\r
 569         tskTCB *pxTCB;\r
 570 \r
 571                 taskENTER_CRITICAL();\r
 572                 {\r
 573                         /* Ensure a yield is performed if the current task is being\r
 574                         deleted. */\r
 575                         if( pxTaskToDelete == pxCurrentTCB )\r
 576                         {\r
 577                                 pxTaskToDelete = NULL;\r
 578                         }\r
 579 \r
 580                         /* If null is passed in here then we are deleting ourselves. */\r
 581                         pxTCB = prvGetTCBFromHandle( pxTaskToDelete );\r
 582 \r
 583                         traceTASK_DELETE( pxTCB );\r
 584 \r
 585                         /* Remove task from the ready list and place in the     termination list.\r
 586                         This will stop the task from be scheduled.  The idle task will check\r
 587                         the termination list and free up any memory allocated by the\r
 588                         scheduler for the TCB and stack. */\r
 589                         vListRemove( &( pxTCB->xGenericListItem ) );\r
 590 \r
 591                         /* Is the task waiting on an event also? */                                                                                             \r
 592                         if( pxTCB->xEventListItem.pvContainer )\r
 593                         {\r
 594                                 vListRemove( &( pxTCB->xEventListItem ) );\r
 595                         }\r
 596 \r
 597                         vListInsertEnd( ( xList * ) &xTasksWaitingTermination, &( pxTCB->xGenericListItem ) );\r
 598 \r
 599                         /* Increment the ucTasksDeleted variable so the idle task knows\r
 600                         there is a task that has been deleted and that it should therefore\r
 601                         check the xTasksWaitingTermination list. */\r
 602                         ++uxTasksDeleted;\r
 603                 }\r
 604                 taskEXIT_CRITICAL();\r
 605 \r
 606                 /* Force a reschedule if we have just deleted the current task. */\r
 607                 if( xSchedulerRunning != pdFALSE )\r
 608                 {\r
 609                         if( ( void * ) pxTaskToDelete == NULL )\r
 610                         {\r
 611                                 taskYIELD();\r
 612                         }\r
 613                 }\r
 614         }\r
 615 \r
 616 #endif\r
 617 \r
 618 \r
 619 \r
 620 \r
 621 \r
 622 \r
 623 /*-----------------------------------------------------------\r
 624  * TASK CONTROL API documented in task.h\r
 625  *----------------------------------------------------------*/\r
 626 \r
 627 #if ( INCLUDE_vTaskDelayUntil == 1 )\r
 628 \r
 629         void vTaskDelayUntil( portTickType * const pxPreviousWakeTime, portTickType xTimeIncrement )\r
 630         {\r
 631         portTickType xTimeToWake;\r
 632         portBASE_TYPE xAlreadyYielded, xShouldDelay = pdFALSE;\r
 633 \r
 634                 vTaskSuspendAll();\r
 635                 {\r
 636                         /* Generate the tick time at which the task wants to wake. */\r
 637                         xTimeToWake = *pxPreviousWakeTime + xTimeIncrement;\r
 638 \r
 639                         if( xTickCount < *pxPreviousWakeTime )\r
 640                         {\r
 641                                 /* The tick count has overflowed since this function was\r
 642                                 lasted called.  In this case the only time we should ever\r
 643                                 actually delay is if the wake time has also     overflowed,\r
 644                                 and the wake time is greater than the tick time.  When this\r
 645                                 is the case it is as if neither time had overflowed. */\r
 646                                 if( ( xTimeToWake < *pxPreviousWakeTime ) && ( xTimeToWake > xTickCount ) )\r
 647                                 {\r
 648                                         xShouldDelay = pdTRUE;\r
 649                                 }\r
 650                         }\r
 651                         else\r
 652                         {\r
 653                                 /* The tick time has not overflowed.  In this case we will\r
 654                                 delay if either the wake time has overflowed, and/or the\r
 655                                 tick time is less than the wake time. */\r
 656                                 if( ( xTimeToWake < *pxPreviousWakeTime ) || ( xTimeToWake > xTickCount ) )\r
 657                                 {\r
 658                                         xShouldDelay = pdTRUE;\r
 659                                 }\r
 660                         }\r
 661 \r
 662                         /* Update the wake time ready for the next call. */\r
 663                         *pxPreviousWakeTime = xTimeToWake;\r
 664 \r
 665                         if( xShouldDelay )\r
 666                         {\r
 667                                 traceTASK_DELAY_UNTIL();\r
 668 \r
 669                                 /* We must remove ourselves from the ready list before adding\r
 670                                 ourselves to the blocked list as the same list item is used for\r
 671                                 both lists. */\r
 672                                 vListRemove( ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );\r
 673 \r
 674                                 /* The list item will be inserted in wake time order. */\r
 675                                 listSET_LIST_ITEM_VALUE( &( pxCurrentTCB->xGenericListItem ), xTimeToWake );\r
 676 \r
 677                                 if( xTimeToWake < xTickCount )\r
 678                                 {\r
 679                                         /* Wake time has overflowed.  Place this item in the\r
 680                                         overflow list. */\r
 681                                         vListInsert( ( xList * ) pxOverflowDelayedTaskList, ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );\r
 682                                 }\r
 683                                 else\r
 684                                 {\r
 685                                         /* The wake time has not overflowed, so we can use the\r
 686                                         current block list. */\r
 687                                         vListInsert( ( xList * ) pxDelayedTaskList, ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );\r
 688                                 }\r
 689                         }\r
 690                 }\r
 691                 xAlreadyYielded = xTaskResumeAll();\r
 692 \r
 693                 /* Force a reschedule if xTaskResumeAll has not already done so, we may\r
 694                 have put ourselves to sleep. */\r
 695                 if( !xAlreadyYielded )\r
 696                 {\r
 697                         taskYIELD();\r
 698                 }\r
 699         }       \r
 700         \r
 701 #endif\r
 702 /*-----------------------------------------------------------*/\r
 703 \r
 704 #if ( INCLUDE_vTaskDelay == 1 )\r
 705 \r
 706         void vTaskDelay( portTickType xTicksToDelay )\r
 707         {\r
 708         portTickType xTimeToWake;\r
 709         signed portBASE_TYPE xAlreadyYielded = pdFALSE;\r
 710 \r
 711                 /* A delay time of zero just forces a reschedule. */\r
 712                 if( xTicksToDelay > ( portTickType ) 0 )\r
 713                 {\r
 714                         vTaskSuspendAll();\r
 715                         {\r
 716                                 traceTASK_DELAY();\r
 717 \r
 718                                 /* A task that is removed from the event list while the\r
 719                                 scheduler is suspended will not get placed in the ready\r
 720                                 list or removed from the blocked list until the scheduler\r
 721                                 is resumed.\r
 722                                 \r
 723                                 This task cannot be in an event list as it is the currently\r
 724                                 executing task. */\r
 725 \r
 726                                 /* Calculate the time to wake - this may overflow but this is\r
 727                                 not a problem. */\r
 728                                 xTimeToWake = xTickCount + xTicksToDelay;\r
 729 \r
 730                                 /* We must remove ourselves from the ready list before adding\r
 731                                 ourselves to the blocked list as the same list item is used for\r
 732                                 both lists. */\r
 733                                 vListRemove( ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );\r
 734 \r
 735                                 /* The list item will be inserted in wake time order. */\r
 736                                 listSET_LIST_ITEM_VALUE( &( pxCurrentTCB->xGenericListItem ), xTimeToWake );\r
 737 \r
 738                                 if( xTimeToWake < xTickCount )\r
 739                                 {\r
 740                                         /* Wake time has overflowed.  Place this item in the\r
 741                                         overflow list. */\r
 742                                         vListInsert( ( xList * ) pxOverflowDelayedTaskList, ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );\r
 743                                 }\r
 744                                 else\r
 745                                 {\r
 746                                         /* The wake time has not overflowed, so we can use the\r
 747                                         current block list. */\r
 748                                         vListInsert( ( xList * ) pxDelayedTaskList, ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );\r
 749                                 }\r
 750                         }\r
 751                         xAlreadyYielded = xTaskResumeAll();\r
 752                 }\r
 753                 \r
 754                 /* Force a reschedule if xTaskResumeAll has not already done so, we may\r
 755                 have put ourselves to sleep. */\r
 756                 if( !xAlreadyYielded )\r
 757                 {\r
 758                         taskYIELD();\r
 759                 }\r
 760         }\r
 761         \r
 762 #endif\r
 763 /*-----------------------------------------------------------*/\r
 764 \r
 765 #if ( INCLUDE_uxTaskPriorityGet == 1 )\r
 766 \r
 767         unsigned portBASE_TYPE uxTaskPriorityGet( xTaskHandle pxTask )\r
 768         {\r
 769         tskTCB *pxTCB;\r
 770         unsigned portBASE_TYPE uxReturn;\r
 771 \r
 772                 taskENTER_CRITICAL();\r
 773                 {\r
 774                         /* If null is passed in here then we are changing the\r
 775                         priority of the calling function. */\r
 776                         pxTCB = prvGetTCBFromHandle( pxTask );\r
 777                         uxReturn = pxTCB->uxPriority;\r
 778                 }\r
 779                 taskEXIT_CRITICAL();\r
 780 \r
 781                 return uxReturn;\r
 782         }\r
 783 \r
 784 #endif\r
 785 /*-----------------------------------------------------------*/\r
 786 \r
 787 #if ( INCLUDE_vTaskPrioritySet == 1 )\r
 788 \r
 789         void vTaskPrioritySet( xTaskHandle pxTask, unsigned portBASE_TYPE uxNewPriority )\r
 790         {\r
 791         tskTCB *pxTCB;\r
 792         unsigned portBASE_TYPE uxCurrentPriority, xYieldRequired = pdFALSE;\r
 793 \r
 794                 /* Ensure the new priority is valid. */\r
 795                 if( uxNewPriority >= configMAX_PRIORITIES )\r
 796                 {\r
 797                         uxNewPriority = configMAX_PRIORITIES - 1;\r
 798                 }\r
 799 \r
 800                 taskENTER_CRITICAL();\r
 801                 {\r
 802                         /* If null is passed in here then we are changing the\r
 803                         priority of the calling function. */\r
 804                         pxTCB = prvGetTCBFromHandle( pxTask );\r
 805                         \r
 806                         traceTASK_PRIORITY_SET( pxTask, uxNewPriority );\r
 807 \r
 808                         #if ( configUSE_MUTEXES == 1 )\r
 809                         {\r
 810                                 uxCurrentPriority = pxTCB->uxBasePriority;\r
 811                         }\r
 812                         #else\r
 813                         {\r
 814                                 uxCurrentPriority = pxTCB->uxPriority;\r
 815                         }\r
 816                         #endif\r
 817 \r
 818                         if( uxCurrentPriority != uxNewPriority )\r
 819                         {\r
 820                                 /* The priority change may have readied a task of higher\r
 821                                 priority than the calling task. */\r
 822                                 if( uxNewPriority > uxCurrentPriority )\r
 823                                 {\r
 824                                         if( pxTask != NULL )\r
 825                                         {\r
 826                                                 /* The priority of another task is being raised.  If we\r
 827                                                 were raising the priority of the currently running task\r
 828                                                 there would be no need to switch as it must have already\r
 829                                                 been the highest priority task. */\r
 830                                                 xYieldRequired = pdTRUE;\r
 831                                         }\r
 832                                 }\r
 833                                 else if( pxTask == NULL )\r
 834                                 {\r
 835                                         /* Setting our own priority down means there may now be another\r
 836                                         task of higher priority that is ready to execute. */\r
 837                                         xYieldRequired = pdTRUE;\r
 838                                 }\r
 839                         \r
 840                                 \r
 841 \r
 842                                 #if ( configUSE_MUTEXES == 1 )\r
 843                                 {\r
 844                                         /* Only change the priority being used if the task is not\r
 845                                         currently using an inherited priority. */\r
 846                                         if( pxTCB->uxBasePriority == pxTCB->uxPriority )\r
 847                                         {\r
 848                                                 pxTCB->uxPriority = uxNewPriority;\r
 849                                         }\r
 850                                         \r
 851                                         /* The base priority gets set whatever. */\r
 852                                         pxTCB->uxBasePriority = uxNewPriority;                                  \r
 853                                 }\r
 854                                 #else\r
 855                                 {\r
 856                                         pxTCB->uxPriority = uxNewPriority;\r
 857                                 }\r
 858                                 #endif\r
 859 \r
 860                                 listSET_LIST_ITEM_VALUE( &( pxTCB->xEventListItem ), ( configMAX_PRIORITIES - ( portTickType ) uxNewPriority ) );\r
 861 \r
 862                                 /* If the task is in the blocked or suspended list we need do\r
 863                                 nothing more than change it's priority variable. However, if\r
 864                                 the task is in a ready list it needs to be removed and placed\r
 865                                 in the queue appropriate to its new priority. */\r
 866                                 if( listIS_CONTAINED_WITHIN( &( pxReadyTasksLists[ uxCurrentPriority ] ), &( pxTCB->xGenericListItem ) ) )\r
 867                                 {\r
 868                                         /* The task is currently in its ready list - remove before adding\r
 869                                         it to it's new ready list.  As we are in a critical section we\r
 870                                         can do this even if the scheduler is suspended. */\r
 871                                         vListRemove( &( pxTCB->xGenericListItem ) );\r
 872                                         prvAddTaskToReadyQueue( pxTCB );\r
 873                                 }                       \r
 874                                 \r
 875                                 if( xYieldRequired == pdTRUE )\r
 876                                 {\r
 877                                         taskYIELD();\r
 878                                 }                               \r
 879                         }\r
 880                 }\r
 881                 taskEXIT_CRITICAL();\r
 882         }\r
 883 \r
 884 #endif\r
 885 /*-----------------------------------------------------------*/\r
 886 \r
 887 #if ( INCLUDE_vTaskSuspend == 1 )\r
 888 \r
 889         void vTaskSuspend( xTaskHandle pxTaskToSuspend )\r
 890         {\r
 891         tskTCB *pxTCB;\r
 892 \r
 893                 taskENTER_CRITICAL();\r
 894                 {\r
 895                         /* Ensure a yield is performed if the current task is being\r
 896                         suspended. */\r
 897                         if( pxTaskToSuspend == pxCurrentTCB )\r
 898                         {\r
 899                                 pxTaskToSuspend = NULL;\r
 900                         }\r
 901 \r
 902                         /* If null is passed in here then we are suspending ourselves. */\r
 903                         pxTCB = prvGetTCBFromHandle( pxTaskToSuspend );\r
 904 \r
 905                         traceTASK_SUSPEND( pxTaskToSuspend );\r
 906 \r
 907                         /* Remove task from the ready/delayed list and place in the     suspended list. */\r
 908                         vListRemove( &( pxTCB->xGenericListItem ) );\r
 909 \r
 910                         /* Is the task waiting on an event also? */                                                                                             \r
 911                         if( pxTCB->xEventListItem.pvContainer )\r
 912                         {\r
 913                                 vListRemove( &( pxTCB->xEventListItem ) );\r
 914                         }\r
 915 \r
 916                         vListInsertEnd( ( xList * ) &xSuspendedTaskList, &( pxTCB->xGenericListItem ) );\r
 917                 }\r
 918                 taskEXIT_CRITICAL();\r
 919 \r
 920                 /* We may have just suspended the current task. */\r
 921                 if( ( void * ) pxTaskToSuspend == NULL )\r
 922                 {\r
 923                         taskYIELD();\r
 924                 }\r
 925         }\r
 926 \r
 927 #endif\r
 928 /*-----------------------------------------------------------*/\r
 929 \r
 930 #if ( INCLUDE_vTaskSuspend == 1 )\r
 931 \r
 932         static portBASE_TYPE prvIsTaskSuspended( const tskTCB * const pxTCB )\r
 933         {\r
 934         portBASE_TYPE xReturn = pdFALSE;\r
 935 \r
 936                 /* Is the task we are attempting to resume actually in the\r
 937                 suspended list? */\r
 938                 if( listIS_CONTAINED_WITHIN( &xSuspendedTaskList, &( pxTCB->xGenericListItem ) ) != pdFALSE )\r
 939                 {\r
 940                         /* Has the task already been resumed from within an ISR? */\r
 941                         if( listIS_CONTAINED_WITHIN( &xPendingReadyList, &( pxTCB->xEventListItem ) ) != pdTRUE )\r
 942                         {                       \r
 943                                 /* Is it in the suspended list because it is in the\r
 944                                 Suspended state?  It is possible to be in the suspended\r
 945                                 list because it is blocked on a task with no timeout\r
 946                                 specified. */\r
 947                                 if( listIS_CONTAINED_WITHIN( NULL, &( pxTCB->xEventListItem ) ) == pdTRUE )\r
 948                                 {\r
 949                                         xReturn = pdTRUE;\r
 950                                 }\r
 951                         }\r
 952                 }\r
 953 \r
 954                 return xReturn;\r
 955         }\r
 956 \r
 957 #endif\r
 958 /*-----------------------------------------------------------*/\r
 959 \r
 960 #if ( INCLUDE_vTaskSuspend == 1 )\r
 961 \r
 962         void vTaskResume( xTaskHandle pxTaskToResume )\r
 963         {\r
 964         tskTCB *pxTCB;\r
 965 \r
 966                 /* Remove the task from whichever list it is currently in, and place\r
 967                 it in the ready list. */\r
 968                 pxTCB = ( tskTCB * ) pxTaskToResume;\r
 969 \r
 970                 /* The parameter cannot be NULL as it is impossible to resume the\r
 971                 currently executing task. */\r
 972                 if( pxTCB != NULL )\r
 973                 {\r
 974                         taskENTER_CRITICAL();\r
 975                         {\r
 976                                 if( prvIsTaskSuspended( pxTCB ) == pdTRUE )\r
 977                                 {\r
 978                                         traceTASK_RESUME( pxTCB );\r
 979 \r
 980                                         /* As we are in a critical section we can access the ready\r
 981                                         lists even if the scheduler is suspended. */\r
 982                                         vListRemove(  &( pxTCB->xGenericListItem ) );\r
 983                                         prvAddTaskToReadyQueue( pxTCB );\r
 984 \r
 985                                         /* We may have just resumed a higher priority task. */\r
 986                                         if( pxTCB->uxPriority >= pxCurrentTCB->uxPriority )\r
 987                                         {\r
 988                                                 /* This yield may not cause the task just resumed to run, but\r
 989                                                 will leave the lists in the correct state for the next yield. */\r
 990                                                 taskYIELD();\r
 991                                         }\r
 992                                 }\r
 993                         }\r
 994                         taskEXIT_CRITICAL();\r
 995                 }\r
 996         }\r
 997 \r
 998 #endif\r
 999 \r
1000 /*-----------------------------------------------------------*/\r
1001 \r
1002 #if ( ( INCLUDE_xTaskResumeFromISR == 1 ) && ( INCLUDE_vTaskSuspend == 1 ) )\r
1003 \r
1004         portBASE_TYPE xTaskResumeFromISR( xTaskHandle pxTaskToResume )\r
1005         {\r
1006         portBASE_TYPE xYieldRequired = pdFALSE;\r
1007         tskTCB *pxTCB;\r
1008 \r
1009                 pxTCB = ( tskTCB * ) pxTaskToResume;\r
1010 \r
1011                 if( prvIsTaskSuspended( pxTCB ) == pdTRUE )\r
1012                 {\r
1013                         traceTASK_RESUME_FROM_ISR( pxTCB );\r
1014 \r
1015                         if( uxSchedulerSuspended == ( unsigned portBASE_TYPE ) pdFALSE )\r
1016                         {\r
1017                                 xYieldRequired = ( pxTCB->uxPriority >= pxCurrentTCB->uxPriority );\r
1018                                 vListRemove(  &( pxTCB->xGenericListItem ) );   \r
1019                                 prvAddTaskToReadyQueue( pxTCB );\r
1020                         }\r
1021                         else\r
1022                         {\r
1023                                 /* We cannot access the delayed or ready lists, so will hold this\r
1024                                 task pending until the scheduler is resumed, at which point a\r
1025                                 yield will be performed if necessary. */\r
1026                                 vListInsertEnd( ( xList * ) &( xPendingReadyList ), &( pxTCB->xEventListItem ) );\r
1027                         }\r
1028                 }\r
1029 \r
1030                 return xYieldRequired;\r
1031         }\r
1032 \r
1033 #endif\r
1034 \r
1035 \r
1036 \r
1037 \r
1038 /*-----------------------------------------------------------\r
1039  * PUBLIC SCHEDULER CONTROL documented in task.h\r
1040  *----------------------------------------------------------*/\r
1041 \r
1042 \r
1043 void vTaskStartScheduler( void )\r
1044 {\r
1045 portBASE_TYPE xReturn;\r
1046 \r
1047         /* Add the idle task at the lowest priority. */\r
1048         xReturn = xTaskCreate( prvIdleTask, ( signed portCHAR * ) "IDLE", tskIDLE_STACK_SIZE, ( void * ) NULL, tskIDLE_PRIORITY, ( xTaskHandle * ) NULL );\r
1049 \r
1050         if( xReturn == pdPASS )\r
1051         {\r
1052                 /* Interrupts are turned off here, to ensure a tick does not occur\r
1053                 before or during the call to xPortStartScheduler().  The stacks of\r
1054                 the created tasks contain a status word with interrupts switched on\r
1055                 so interrupts will automatically get re-enabled when the first task\r
1056                 starts to run.\r
1057                 \r
1058                 STEPPING THROUGH HERE USING A DEBUGGER CAN CAUSE BIG PROBLEMS IF THE\r
1059                 DEBUGGER ALLOWS INTERRUPTS TO BE PROCESSED. */\r
1060                 portDISABLE_INTERRUPTS();\r
1061 \r
1062                 xSchedulerRunning = pdTRUE;\r
1063                 xTickCount = ( portTickType ) 0;\r
1064 \r
1065                 /* Setting up the timer tick is hardware specific and thus in the\r
1066                 portable interface. */\r
1067                 if( xPortStartScheduler() )\r
1068                 {\r
1069                         /* Should not reach here as if the scheduler is running the\r
1070                         function will not return. */\r
1071                 }\r
1072                 else\r
1073                 {\r
1074                         /* Should only reach here if a task calls xTaskEndScheduler(). */\r
1075                 }\r
1076         }\r
1077 }\r
1078 /*-----------------------------------------------------------*/\r
1079 \r
1080 void vTaskEndScheduler( void )\r
1081 {\r
1082         /* Stop the scheduler interrupts and call the portable scheduler end\r
1083         routine so the original ISRs can be restored if necessary.  The port\r
1084         layer must ensure interrupts enable     bit is left in the correct state. */\r
1085         portDISABLE_INTERRUPTS();\r
1086         xSchedulerRunning = pdFALSE;\r
1087         vPortEndScheduler();\r
1088 }\r
1089 /*----------------------------------------------------------*/\r
1090 \r
1091 void vTaskSuspendAll( void )\r
1092 {\r
1093         portENTER_CRITICAL();\r
1094                 ++uxSchedulerSuspended;\r
1095         portEXIT_CRITICAL();\r
1096 }\r
1097 /*----------------------------------------------------------*/\r
1098 \r
1099 signed portBASE_TYPE xTaskResumeAll( void )\r
1100 {\r
1101 register tskTCB *pxTCB;\r
1102 signed portBASE_TYPE xAlreadyYielded = pdFALSE;\r
1103 \r
1104         /* It is possible that an ISR caused a task to be removed from an event\r
1105         list while the scheduler was suspended.  If this was the case then the\r
1106         removed task will have been added to the xPendingReadyList.  Once the\r
1107         scheduler has been resumed it is safe to move all the pending ready\r
1108         tasks from this list into their appropriate ready list. */\r
1109         portENTER_CRITICAL();\r
1110         {\r
1111                 --uxSchedulerSuspended;\r
1112 \r
1113                 if( uxSchedulerSuspended == ( unsigned portBASE_TYPE ) pdFALSE )\r
1114                 {                       \r
1115                         if( uxCurrentNumberOfTasks > ( unsigned portBASE_TYPE ) 0 )\r
1116                         {\r
1117                                 portBASE_TYPE xYieldRequired = pdFALSE;\r
1118                                 \r
1119                                 /* Move any readied tasks from the pending list into the\r
1120                                 appropriate ready list. */\r
1121                                 while( ( pxTCB = ( tskTCB * ) listGET_OWNER_OF_HEAD_ENTRY(  ( ( xList * ) &xPendingReadyList ) ) ) != NULL )\r
1122                                 {\r
1123                                         vListRemove( &( pxTCB->xEventListItem ) );\r
1124                                         vListRemove( &( pxTCB->xGenericListItem ) );\r
1125                                         prvAddTaskToReadyQueue( pxTCB );\r
1126                                         \r
1127                                         /* If we have moved a task that has a priority higher than\r
1128                                         the current task then we should yield. */\r
1129                                         if( pxTCB->uxPriority >= pxCurrentTCB->uxPriority )\r
1130                                         {\r
1131                                                 xYieldRequired = pdTRUE;\r
1132                                         }\r
1133                                 }\r
1134 \r
1135                                 /* If any ticks occurred while the scheduler was suspended then\r
1136                                 they should be processed now.  This ensures the tick count does not\r
1137                                 slip, and that any delayed tasks are resumed at the correct time. */\r
1138                                 if( uxMissedTicks > ( unsigned portBASE_TYPE ) 0 )\r
1139                                 {\r
1140                                         while( uxMissedTicks > ( unsigned portBASE_TYPE ) 0 )\r
1141                                         {\r
1142                                                 vTaskIncrementTick();\r
1143                                                 --uxMissedTicks;\r
1144                                         }\r
1145 \r
1146                                         /* As we have processed some ticks it is appropriate to yield\r
1147                                         to ensure the highest priority task that is ready to run is\r
1148                                         the task actually running. */\r
1149                                         #if configUSE_PREEMPTION == 1\r
1150                                         {\r
1151                                                 xYieldRequired = pdTRUE;\r
1152                                         }\r
1153                                         #endif\r
1154                                 }\r
1155                                 \r
1156                                 if( ( xYieldRequired == pdTRUE ) || ( xMissedYield == pdTRUE ) )\r
1157                                 {\r
1158                                         xAlreadyYielded = pdTRUE;\r
1159                                         xMissedYield = pdFALSE;\r
1160                                         taskYIELD();\r
1161                                 }\r
1162                         }\r
1163                 }\r
1164         }\r
1165         portEXIT_CRITICAL();\r
1166 \r
1167         return xAlreadyYielded;\r
1168 }\r
1169 \r
1170 \r
1171 \r
1172 \r
1173 \r
1174 \r
1175 /*-----------------------------------------------------------\r
1176  * PUBLIC TASK UTILITIES documented in task.h\r
1177  *----------------------------------------------------------*/\r
1178 \r
1179 \r
1180 \r
1181 portTickType xTaskGetTickCount( void )\r
1182 {\r
1183 portTickType xTicks;\r
1184 \r
1185         /* Critical section required if running on a 16 bit processor. */\r
1186         taskENTER_CRITICAL();\r
1187         {\r
1188                 xTicks = xTickCount;\r
1189         }\r
1190         taskEXIT_CRITICAL();\r
1191 \r
1192         return xTicks;\r
1193 }\r
1194 /*-----------------------------------------------------------*/\r
1195 \r
1196 unsigned portBASE_TYPE uxTaskGetNumberOfTasks( void )\r
1197 {\r
1198 unsigned portBASE_TYPE uxNumberOfTasks;\r
1199 \r
1200         taskENTER_CRITICAL();\r
1201                 uxNumberOfTasks = uxCurrentNumberOfTasks;\r
1202         taskEXIT_CRITICAL();\r
1203 \r
1204         return uxNumberOfTasks;\r
1205 }\r
1206 /*-----------------------------------------------------------*/\r
1207 \r
1208 #if ( ( configUSE_TRACE_FACILITY == 1 ) && ( INCLUDE_vTaskDelete == 1 ) && ( INCLUDE_vTaskSuspend == 1 ) )\r
1209 \r
1210         void vTaskList( signed portCHAR *pcWriteBuffer )\r
1211         {\r
1212         unsigned portBASE_TYPE uxQueue;\r
1213 \r
1214                 /* This is a VERY costly function that should be used for debug only.\r
1215                 It leaves interrupts disabled for a LONG time. */\r
1216 \r
1217         vTaskSuspendAll();\r
1218                 {\r
1219                         /* Run through all the lists that could potentially contain a TCB and\r
1220                         report the task name, state and stack high water mark. */\r
1221 \r
1222                         pcWriteBuffer[ 0 ] = ( signed portCHAR ) 0x00;\r
1223                         strcat( ( portCHAR * ) pcWriteBuffer, ( const portCHAR * ) "\r\n" );\r
1224 \r
1225                         uxQueue = uxTopUsedPriority + 1;\r
1226 \r
1227                         do\r
1228                         {\r
1229                                 uxQueue--;\r
1230 \r
1231                                 if( !listLIST_IS_EMPTY( &( pxReadyTasksLists[ uxQueue ] ) ) )\r
1232                                 {\r
1233                                         prvListTaskWithinSingleList( pcWriteBuffer, ( xList * ) &( pxReadyTasksLists[ uxQueue ] ), tskREADY_CHAR );                     \r
1234                                 }\r
1235                         }while( uxQueue > ( unsigned portSHORT ) tskIDLE_PRIORITY );\r
1236 \r
1237                         if( !listLIST_IS_EMPTY( pxDelayedTaskList ) )\r
1238                         {\r
1239                                 prvListTaskWithinSingleList( pcWriteBuffer, ( xList * ) pxDelayedTaskList, tskBLOCKED_CHAR );\r
1240                         }\r
1241 \r
1242                         if( !listLIST_IS_EMPTY( pxOverflowDelayedTaskList ) )\r
1243                         {\r
1244                                 prvListTaskWithinSingleList( pcWriteBuffer, ( xList * ) pxOverflowDelayedTaskList, tskBLOCKED_CHAR );\r
1245                         }\r
1246 \r
1247                         if( !listLIST_IS_EMPTY( &xTasksWaitingTermination ) )\r
1248                         {\r
1249                                 prvListTaskWithinSingleList( pcWriteBuffer, ( xList * ) &xTasksWaitingTermination, tskDELETED_CHAR );\r
1250                         }\r
1251 \r
1252                         if( !listLIST_IS_EMPTY( &xSuspendedTaskList ) )\r
1253                         {\r
1254                                 prvListTaskWithinSingleList( pcWriteBuffer, ( xList * ) &xSuspendedTaskList, tskSUSPENDED_CHAR );\r
1255                         }\r
1256                 }\r
1257         xTaskResumeAll();\r
1258         }\r
1259 \r
1260 #endif\r
1261 /*----------------------------------------------------------*/\r
1262 \r
1263 #if ( configUSE_TRACE_FACILITY == 1 )\r
1264 \r
1265         void vTaskStartTrace( signed portCHAR * pcBuffer, unsigned portLONG ulBufferSize )\r
1266         {\r
1267                 portENTER_CRITICAL();\r
1268                 {\r
1269                         pcTraceBuffer = ( signed portCHAR * )pcBuffer;\r
1270                         pcTraceBufferStart = pcBuffer;\r
1271                         pcTraceBufferEnd = pcBuffer + ( ulBufferSize - tskSIZE_OF_EACH_TRACE_LINE );\r
1272                         xTracing = pdTRUE;\r
1273                 }\r
1274                 portEXIT_CRITICAL();\r
1275         }\r
1276 \r
1277 #endif\r
1278 /*----------------------------------------------------------*/\r
1279 \r
1280 #if ( configUSE_TRACE_FACILITY == 1 )\r
1281 \r
1282         unsigned portLONG ulTaskEndTrace( void )\r
1283         {\r
1284         unsigned portLONG ulBufferLength;\r
1285 \r
1286                 portENTER_CRITICAL();\r
1287                         xTracing = pdFALSE;\r
1288                 portEXIT_CRITICAL();\r
1289 \r
1290                 ulBufferLength = ( unsigned portLONG ) ( pcTraceBuffer - pcTraceBufferStart );\r
1291 \r
1292                 return ulBufferLength;\r
1293         }\r
1294 \r
1295 #endif\r
1296 \r
1297 \r
1298 \r
1299 /*-----------------------------------------------------------\r
1300  * SCHEDULER INTERNALS AVAILABLE FOR PORTING PURPOSES\r
1301  * documented in task.h\r
1302  *----------------------------------------------------------*/\r
1303 \r
1304 \r
1305 inline void vTaskIncrementTick( void )\r
1306 {\r
1307         /* Called by the portable layer each time a tick interrupt occurs.\r
1308         Increments the tick then checks to see if the new tick value will cause any\r
1309         tasks to be unblocked. */\r
1310         if( uxSchedulerSuspended == ( unsigned portBASE_TYPE ) pdFALSE )\r
1311         {\r
1312                 ++xTickCount;\r
1313                 if( xTickCount == ( portTickType ) 0 )\r
1314                 {\r
1315                         xList *pxTemp;\r
1316 \r
1317                         /* Tick count has overflowed so we need to swap the delay lists.\r
1318                         If there are any items in pxDelayedTaskList here then there is\r
1319                         an error! */\r
1320                         pxTemp = pxDelayedTaskList;\r
1321                         pxDelayedTaskList = pxOverflowDelayedTaskList;\r
1322                         pxOverflowDelayedTaskList = pxTemp;\r
1323             xNumOfOverflows++;\r
1324                 }\r
1325 \r
1326                 /* See if this tick has made a timeout expire. */\r
1327                 prvCheckDelayedTasks();\r
1328         }\r
1329         else\r
1330         {\r
1331                 ++uxMissedTicks;\r
1332 \r
1333                 /* The tick hook gets called at regular intervals, even if the\r
1334                 scheduler is locked. */\r
1335                 #if ( configUSE_TICK_HOOK == 1 )\r
1336                 {\r
1337                         extern void vApplicationTickHook( void );\r
1338 \r
1339                         vApplicationTickHook();\r
1340                 }\r
1341                 #endif\r
1342         }\r
1343 \r
1344         #if ( configUSE_TICK_HOOK == 1 )\r
1345         {\r
1346                 extern void vApplicationTickHook( void );\r
1347 \r
1348                 /* Guard against the tick hook being called when the missed tick\r
1349                 count is being unwound (when the scheduler is being unlocked. */\r
1350                 if( uxMissedTicks == 0 )\r
1351                 {\r
1352                         vApplicationTickHook();\r
1353                 }\r
1354         }\r
1355         #endif\r
1356 \r
1357         traceTASK_INCREMENT_TICK( xTickCount );\r
1358 }\r
1359 /*-----------------------------------------------------------*/\r
1360 \r
1361 #if ( ( INCLUDE_vTaskCleanUpResources == 1 ) && ( INCLUDE_vTaskSuspend == 1 ) )\r
1362 \r
1363         void vTaskCleanUpResources( void )\r
1364         {\r
1365         unsigned portSHORT usQueue;\r
1366         volatile tskTCB *pxTCB;\r
1367 \r
1368                 usQueue = ( unsigned portSHORT ) uxTopUsedPriority + ( unsigned portSHORT ) 1;\r
1369 \r
1370                 /* Remove any TCB's from the ready queues. */\r
1371                 do\r
1372                 {\r
1373                         usQueue--;\r
1374 \r
1375                         while( !listLIST_IS_EMPTY( &( pxReadyTasksLists[ usQueue ] ) ) )\r
1376                         {\r
1377                                 listGET_OWNER_OF_NEXT_ENTRY( pxTCB, &( pxReadyTasksLists[ usQueue ] ) );\r
1378                                 vListRemove( ( xListItem * ) &( pxTCB->xGenericListItem ) );\r
1379 \r
1380                                 prvDeleteTCB( ( tskTCB * ) pxTCB );\r
1381                         }\r
1382                 }while( usQueue > ( unsigned portSHORT ) tskIDLE_PRIORITY );\r
1383 \r
1384                 /* Remove any TCB's from the delayed queue. */\r
1385                 while( !listLIST_IS_EMPTY( &xDelayedTaskList1 ) )\r
1386                 {\r
1387                         listGET_OWNER_OF_NEXT_ENTRY( pxTCB, &xDelayedTaskList1 );\r
1388                         vListRemove( ( xListItem * ) &( pxTCB->xGenericListItem ) );\r
1389 \r
1390                         prvDeleteTCB( ( tskTCB * ) pxTCB );\r
1391                 }\r
1392 \r
1393                 /* Remove any TCB's from the overflow delayed queue. */\r
1394                 while( !listLIST_IS_EMPTY( &xDelayedTaskList2 ) )\r
1395                 {\r
1396                         listGET_OWNER_OF_NEXT_ENTRY( pxTCB, &xDelayedTaskList2 );\r
1397                         vListRemove( ( xListItem * ) &( pxTCB->xGenericListItem ) );\r
1398 \r
1399                         prvDeleteTCB( ( tskTCB * ) pxTCB );\r
1400                 }\r
1401 \r
1402                 while( !listLIST_IS_EMPTY( &xSuspendedTaskList ) )\r
1403                 {\r
1404                         listGET_OWNER_OF_NEXT_ENTRY( pxTCB, &xSuspendedTaskList );\r
1405                         vListRemove( ( xListItem * ) &( pxTCB->xGenericListItem ) );\r
1406 \r
1407                         prvDeleteTCB( ( tskTCB * ) pxTCB );\r
1408                 }               \r
1409         }\r
1410 \r
1411 #endif\r
1412 /*-----------------------------------------------------------*/\r
1413 \r
1414 void vTaskSwitchContext( void )\r
1415 {\r
1416         if( uxSchedulerSuspended != ( unsigned portBASE_TYPE ) pdFALSE )\r
1417         {\r
1418                 /* The scheduler is currently suspended - do not allow a context\r
1419                 switch. */\r
1420                 xMissedYield = pdTRUE;\r
1421                 return;\r
1422         }\r
1423 \r
1424         taskCHECK_FOR_STACK_OVERFLOW();\r
1425 \r
1426         /* Find the highest priority queue that contains ready tasks. */\r
1427         while( listLIST_IS_EMPTY( &( pxReadyTasksLists[ uxTopReadyPriority ] ) ) )\r
1428         {\r
1429                 --uxTopReadyPriority;\r
1430         }\r
1431 \r
1432         /* listGET_OWNER_OF_NEXT_ENTRY walks through the list, so the tasks of the\r
1433         same priority get an equal share of the processor time. */\r
1434         listGET_OWNER_OF_NEXT_ENTRY( pxCurrentTCB, &( pxReadyTasksLists[ uxTopReadyPriority ] ) );\r
1435 \r
1436         traceTASK_SWITCHED_IN();\r
1437         vWriteTraceToBuffer();\r
1438 }\r
1439 /*-----------------------------------------------------------*/\r
1440 \r
1441 void vTaskPlaceOnEventList( const xList * const pxEventList, portTickType xTicksToWait )\r
1442 {\r
1443 portTickType xTimeToWake;\r
1444 \r
1445         /* THIS FUNCTION MUST BE CALLED WITH INTERRUPTS DISABLED OR THE\r
1446         SCHEDULER SUSPENDED. */\r
1447 \r
1448         /* Place the event list item of the TCB in the appropriate event list.\r
1449         This is placed in the list in priority order so the highest priority task\r
1450         is the first to be woken by the event. */\r
1451         vListInsert( ( xList * ) pxEventList, ( xListItem * ) &( pxCurrentTCB->xEventListItem ) );\r
1452 \r
1453         /* We must remove ourselves from the ready list before adding ourselves\r
1454         to the blocked list as the same list item is used for both lists.  We have\r
1455         exclusive access to the ready lists as the scheduler is locked. */\r
1456         vListRemove( ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );\r
1457 \r
1458 \r
1459         #if ( INCLUDE_vTaskSuspend == 1 )\r
1460         {                       \r
1461                 if( xTicksToWait == portMAX_DELAY )\r
1462                 {\r
1463                         /* Add ourselves to the suspended task list instead of a delayed task\r
1464                         list to ensure we are not woken by a timing event.  We will block\r
1465                         indefinitely. */\r
1466                         vListInsertEnd( ( xList * ) &xSuspendedTaskList, ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );\r
1467                 }\r
1468                 else\r
1469                 {\r
1470                         /* Calculate the time at which the task should be woken if the event does\r
1471                         not occur.  This may overflow but this doesn't matter. */\r
1472                         xTimeToWake = xTickCount + xTicksToWait;\r
1473                 \r
1474                         listSET_LIST_ITEM_VALUE( &( pxCurrentTCB->xGenericListItem ), xTimeToWake );\r
1475                 \r
1476                         if( xTimeToWake < xTickCount )\r
1477                         {\r
1478                                 /* Wake time has overflowed.  Place this item in the overflow list. */\r
1479                                 vListInsert( ( xList * ) pxOverflowDelayedTaskList, ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );\r
1480                         }\r
1481                         else\r
1482                         {\r
1483                                 /* The wake time has not overflowed, so we can use the current block list. */\r
1484                                 vListInsert( ( xList * ) pxDelayedTaskList, ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );\r
1485                         }\r
1486                 }\r
1487         }\r
1488         #else\r
1489         {\r
1490                         /* Calculate the time at which the task should be woken if the event does\r
1491                         not occur.  This may overflow but this doesn't matter. */\r
1492                         xTimeToWake = xTickCount + xTicksToWait;\r
1493                 \r
1494                         listSET_LIST_ITEM_VALUE( &( pxCurrentTCB->xGenericListItem ), xTimeToWake );\r
1495                 \r
1496                         if( xTimeToWake < xTickCount )\r
1497                         {\r
1498                                 /* Wake time has overflowed.  Place this item in the overflow list. */\r
1499                                 vListInsert( ( xList * ) pxOverflowDelayedTaskList, ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );\r
1500                         }\r
1501                         else\r
1502                         {\r
1503                                 /* The wake time has not overflowed, so we can use the current block list. */\r
1504                                 vListInsert( ( xList * ) pxDelayedTaskList, ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );\r
1505                         }\r
1506         }\r
1507         #endif\r
1508 }\r
1509 /*-----------------------------------------------------------*/\r
1510 \r
1511 signed portBASE_TYPE xTaskRemoveFromEventList( const xList * const pxEventList )\r
1512 {\r
1513 tskTCB *pxUnblockedTCB;\r
1514 portBASE_TYPE xReturn;\r
1515 \r
1516         /* THIS FUNCTION MUST BE CALLED WITH INTERRUPTS DISABLED OR THE\r
1517         SCHEDULER SUSPENDED.  It can also be called from within an ISR. */\r
1518 \r
1519         /* The event list is sorted in priority order, so we can remove the\r
1520         first in the list, remove the TCB from the delayed list, and add\r
1521         it to the ready list.\r
1522         \r
1523         If an event is for a queue that is locked then this function will never\r
1524         get called - the lock count on the queue will get modified instead.  This\r
1525         means we can always expect exclusive access to the event list here. */\r
1526         pxUnblockedTCB = ( tskTCB * ) listGET_OWNER_OF_HEAD_ENTRY( pxEventList );\r
1527         vListRemove( &( pxUnblockedTCB->xEventListItem ) );\r
1528 \r
1529         if( uxSchedulerSuspended == ( unsigned portBASE_TYPE ) pdFALSE )\r
1530         {\r
1531                 vListRemove( &( pxUnblockedTCB->xGenericListItem ) );\r
1532                 prvAddTaskToReadyQueue( pxUnblockedTCB );\r
1533         }\r
1534         else\r
1535         {\r
1536                 /* We cannot access the delayed or ready lists, so will hold this\r
1537                 task pending until the scheduler is resumed. */\r
1538                 vListInsertEnd( ( xList * ) &( xPendingReadyList ), &( pxUnblockedTCB->xEventListItem ) );\r
1539         }\r
1540 \r
1541         if( pxUnblockedTCB->uxPriority >= pxCurrentTCB->uxPriority )\r
1542         {\r
1543                 /* Return true if the task removed from the event list has\r
1544                 a higher priority than the calling task.  This allows\r
1545                 the calling task to know if it should force a context\r
1546                 switch now. */\r
1547                 xReturn = pdTRUE;\r
1548         }\r
1549         else\r
1550         {\r
1551                 xReturn = pdFALSE;\r
1552         }\r
1553 \r
1554         return xReturn;\r
1555 }\r
1556 /*-----------------------------------------------------------*/\r
1557 \r
1558 void vTaskSetTimeOutState( xTimeOutType * const pxTimeOut )\r
1559 {\r
1560     pxTimeOut->xOverflowCount = xNumOfOverflows;\r
1561     pxTimeOut->xTimeOnEntering = xTickCount;\r
1562 }\r
1563 /*-----------------------------------------------------------*/\r
1564 \r
1565 portBASE_TYPE xTaskCheckForTimeOut( xTimeOutType * const pxTimeOut, portTickType * const pxTicksToWait )\r
1566 {\r
1567 portBASE_TYPE xReturn;\r
1568 \r
1569         portENTER_CRITICAL();\r
1570         {\r
1571                 #if ( INCLUDE_vTaskSuspend == 1 )\r
1572                         /* If INCLUDE_vTaskSuspend is set to 1 and the block time specified is\r
1573                         the maximum block time then the task should block indefinitely, and\r
1574                         therefore never time out. */\r
1575                         if( *pxTicksToWait == portMAX_DELAY )\r
1576                         {\r
1577                                 xReturn = pdFALSE;\r
1578                         }\r
1579                         else /* We are not blocking indefinitely, perform the checks below. */\r
1580                 #endif\r
1581 \r
1582                 if( ( xNumOfOverflows != pxTimeOut->xOverflowCount ) && ( xTickCount >= pxTimeOut->xTimeOnEntering ) )\r
1583                 {\r
1584                         /* The tick count is greater than the time at which vTaskSetTimeout()\r
1585                         was called, but has also overflowed since vTaskSetTimeOut() was called.\r
1586                         It must have wrapped all the way around and gone past us again. This\r
1587                         passed since vTaskSetTimeout() was called. */\r
1588                         xReturn = pdTRUE;\r
1589                 }\r
1590                 else if( ( xTickCount - pxTimeOut->xTimeOnEntering ) < *pxTicksToWait )\r
1591                 {\r
1592                         /* Not a genuine timeout. Adjust parameters for time remaining. */\r
1593                         *pxTicksToWait -= ( xTickCount - pxTimeOut->xTimeOnEntering );\r
1594                         vTaskSetTimeOutState( pxTimeOut );\r
1595                         xReturn = pdFALSE;\r
1596                 }\r
1597                 else\r
1598                 {\r
1599                         xReturn = pdTRUE;\r
1600                 }\r
1601         }\r
1602         portEXIT_CRITICAL();\r
1603 \r
1604     return xReturn;\r
1605 }\r
1606 /*-----------------------------------------------------------*/\r
1607 \r
1608 void vTaskMissedYield( void )\r
1609 {\r
1610         xMissedYield = pdTRUE;\r
1611 }\r
1612 \r
1613 /*\r
1614  * -----------------------------------------------------------\r
1615  * The Idle task.\r
1616  * ----------------------------------------------------------\r
1617  *\r
1618  * The portTASK_FUNCTION() macro is used to allow port/compiler specific\r
1619  * language extensions.  The equivalent prototype for this function is:\r
1620  *\r
1621  * void prvIdleTask( void *pvParameters );\r
1622  *\r
1623  */\r
1624 static portTASK_FUNCTION( prvIdleTask, pvParameters )\r
1625 {\r
1626         /* Stop warnings. */\r
1627         ( void ) pvParameters;\r
1628 \r
1629         for( ;; )\r
1630         {\r
1631                 /* See if any tasks have been deleted. */\r
1632                 prvCheckTasksWaitingTermination();\r
1633 \r
1634                 #if ( configUSE_PREEMPTION == 0 )\r
1635                 {\r
1636                         /* If we are not using preemption we keep forcing a task switch to\r
1637                         see if any other task has become available.  If we are using\r
1638                         preemption we don't need to do this as any task becoming available\r
1639                         will automatically get the processor anyway. */\r
1640                         taskYIELD();    \r
1641                 }\r
1642                 #endif\r
1643 \r
1644                 #if ( ( configUSE_PREEMPTION == 1 ) && ( configIDLE_SHOULD_YIELD == 1 ) )\r
1645                 {\r
1646                         /* When using preemption tasks of equal priority will be\r
1647                         timesliced.  If a task that is sharing the idle priority is ready\r
1648                         to run then the idle task should yield before the end of the\r
1649                         timeslice.\r
1650                         \r
1651                         A critical region is not required here as we are just reading from\r
1652                         the list, and an occasional incorrect value will not matter.  If\r
1653                         the ready list at the idle priority contains more than one task\r
1654                         then a task other than the idle task is ready to execute. */\r
1655                         if( listCURRENT_LIST_LENGTH( &( pxReadyTasksLists[ tskIDLE_PRIORITY ] ) ) > ( unsigned portBASE_TYPE ) 1 )\r
1656                         {\r
1657                                 taskYIELD();\r
1658                         }\r
1659                 }\r
1660                 #endif\r
1661 \r
1662                 #if ( configUSE_IDLE_HOOK == 1 )\r
1663                 {\r
1664                         extern void vApplicationIdleHook( void );\r
1665 \r
1666                         /* Call the user defined function from within the idle task.  This\r
1667                         allows the application designer to add background functionality\r
1668                         without the overhead of a separate task.\r
1669                         NOTE: vApplicationIdleHook() MUST NOT, UNDER ANY CIRCUMSTANCES,\r
1670                         CALL A FUNCTION THAT MIGHT BLOCK. */\r
1671                         vApplicationIdleHook();\r
1672                 }\r
1673                 #endif\r
1674         }\r
1675 } /*lint !e715 pvParameters is not accessed but all task functions require the same prototype. */\r
1676 \r
1677 \r
1678 \r
1679 \r
1680 \r
1681 \r
1682 \r
1683 /*-----------------------------------------------------------\r
1684  * File private functions documented at the top of the file.\r
1685  *----------------------------------------------------------*/\r
1686 \r
1687 \r
1688 \r
1689 static void prvInitialiseTCBVariables( tskTCB *pxTCB, const signed portCHAR * const pcName, unsigned portBASE_TYPE uxPriority )\r
1690 {\r
1691         /* Store the function name in the TCB. */\r
1692         strncpy( ( char * ) pxTCB->pcTaskName, ( const char * ) pcName, ( unsigned portSHORT ) configMAX_TASK_NAME_LEN );\r
1693         pxTCB->pcTaskName[ ( unsigned portSHORT ) configMAX_TASK_NAME_LEN - ( unsigned portSHORT ) 1 ] = '\0';\r
1694 \r
1695         #if ( portCRITICAL_NESTING_IN_TCB == 1 )\r
1696         {\r
1697                 pxTCB->uxCriticalNesting = ( unsigned portBASE_TYPE ) 0;\r
1698         }\r
1699         #endif\r
1700 \r
1701         /* This is used as an array index so must ensure it's not too large. */\r
1702         if( uxPriority >= configMAX_PRIORITIES )\r
1703         {\r
1704                 uxPriority = configMAX_PRIORITIES - 1;\r
1705         }\r
1706 \r
1707         pxTCB->uxPriority = uxPriority;\r
1708         #if ( configUSE_MUTEXES == 1 )\r
1709         {\r
1710                 pxTCB->uxBasePriority = uxPriority;\r
1711         }\r
1712         #endif\r
1713 \r
1714         vListInitialiseItem( &( pxTCB->xGenericListItem ) );\r
1715         vListInitialiseItem( &( pxTCB->xEventListItem ) );\r
1716 \r
1717         /* Set the pxTCB as a link back from the xListItem.  This is so we can get\r
1718         back to the containing TCB from a generic item in a list. */\r
1719         listSET_LIST_ITEM_OWNER( &( pxTCB->xGenericListItem ), pxTCB );\r
1720 \r
1721         /* Event lists are always in priority order. */\r
1722         listSET_LIST_ITEM_VALUE( &( pxTCB->xEventListItem ), configMAX_PRIORITIES - ( portTickType ) uxPriority );\r
1723         listSET_LIST_ITEM_OWNER( &( pxTCB->xEventListItem ), pxTCB );\r
1724 }\r
1725 /*-----------------------------------------------------------*/\r
1726 \r
1727 static void prvInitialiseTaskLists( void )\r
1728 {\r
1729 unsigned portBASE_TYPE uxPriority;\r
1730 \r
1731         for( uxPriority = 0; uxPriority < configMAX_PRIORITIES; uxPriority++ )\r
1732         {\r
1733                 vListInitialise( ( xList * ) &( pxReadyTasksLists[ uxPriority ] ) );\r
1734         }\r
1735 \r
1736         vListInitialise( ( xList * ) &xDelayedTaskList1 );\r
1737         vListInitialise( ( xList * ) &xDelayedTaskList2 );\r
1738         vListInitialise( ( xList * ) &xPendingReadyList );\r
1739 \r
1740         #if ( INCLUDE_vTaskDelete == 1 )\r
1741         {\r
1742                 vListInitialise( ( xList * ) &xTasksWaitingTermination );\r
1743         }\r
1744         #endif\r
1745 \r
1746         #if ( INCLUDE_vTaskSuspend == 1 )\r
1747         {\r
1748                 vListInitialise( ( xList * ) &xSuspendedTaskList );\r
1749         }\r
1750         #endif\r
1751 \r
1752         /* Start with pxDelayedTaskList using list1 and the pxOverflowDelayedTaskList\r
1753         using list2. */\r
1754         pxDelayedTaskList = &xDelayedTaskList1;\r
1755         pxOverflowDelayedTaskList = &xDelayedTaskList2;\r
1756 }\r
1757 /*-----------------------------------------------------------*/\r
1758 \r
1759 static void prvCheckTasksWaitingTermination( void )\r
1760 {                                                       \r
1761         #if ( INCLUDE_vTaskDelete == 1 )\r
1762         {                               \r
1763                 portBASE_TYPE xListIsEmpty;\r
1764 \r
1765                 /* ucTasksDeleted is used to prevent vTaskSuspendAll() being called\r
1766                 too often in the idle task. */\r
1767                 if( uxTasksDeleted > ( unsigned portBASE_TYPE ) 0 )\r
1768                 {\r
1769                         vTaskSuspendAll();\r
1770                                 xListIsEmpty = listLIST_IS_EMPTY( &xTasksWaitingTermination );                          \r
1771                         xTaskResumeAll();\r
1772 \r
1773                         if( !xListIsEmpty )\r
1774                         {\r
1775                                 tskTCB *pxTCB;\r
1776 \r
1777                                 portENTER_CRITICAL();\r
1778                                 {                       \r
1779                                         pxTCB = ( tskTCB * ) listGET_OWNER_OF_HEAD_ENTRY( ( ( xList * ) &xTasksWaitingTermination ) );\r
1780                                         vListRemove( &( pxTCB->xGenericListItem ) );\r
1781                                         --uxCurrentNumberOfTasks;\r
1782                                         --uxTasksDeleted;\r
1783                                 }\r
1784                                 portEXIT_CRITICAL();\r
1785 \r
1786                                 prvDeleteTCB( pxTCB );\r
1787                         }\r
1788                 }\r
1789         }\r
1790         #endif\r
1791 }\r
1792 /*-----------------------------------------------------------*/\r
1793 \r
1794 static tskTCB *prvAllocateTCBAndStack( unsigned portSHORT usStackDepth )\r
1795 {\r
1796 tskTCB *pxNewTCB;\r
1797 \r
1798         /* Allocate space for the TCB.  Where the memory comes from depends on\r
1799         the implementation of the port malloc function. */\r
1800         pxNewTCB = ( tskTCB * ) pvPortMalloc( sizeof( tskTCB ) );\r
1801 \r
1802         if( pxNewTCB != NULL )\r
1803         {\r
1804                 /* Allocate space for the stack used by the task being created.\r
1805                 The base of the stack memory stored in the TCB so the task can\r
1806                 be deleted later if required. */\r
1807                 pxNewTCB->pxStack = ( portSTACK_TYPE * ) pvPortMalloc( ( ( size_t )usStackDepth ) * sizeof( portSTACK_TYPE ) );\r
1808 \r
1809                 if( pxNewTCB->pxStack == NULL )\r
1810                 {\r
1811                         /* Could not allocate the stack.  Delete the allocated TCB. */\r
1812                         vPortFree( pxNewTCB );                  \r
1813                         pxNewTCB = NULL;                        \r
1814                 }               \r
1815                 else\r
1816                 {\r
1817                         /* Just to help debugging. */\r
1818                         memset( pxNewTCB->pxStack, tskSTACK_FILL_BYTE, usStackDepth * sizeof( portSTACK_TYPE ) );\r
1819                 }\r
1820         }\r
1821 \r
1822         return pxNewTCB;\r
1823 }\r
1824 /*-----------------------------------------------------------*/\r
1825 \r
1826 #if ( configUSE_TRACE_FACILITY == 1 )\r
1827 \r
1828         static void prvListTaskWithinSingleList( const signed portCHAR *pcWriteBuffer, xList *pxList, signed portCHAR cStatus )\r
1829         {\r
1830         volatile tskTCB *pxNextTCB, *pxFirstTCB;\r
1831         static portCHAR pcStatusString[ 50 ];\r
1832         unsigned portSHORT usStackRemaining;\r
1833 \r
1834                 /* Write the details of all the TCB's in pxList into the buffer. */\r
1835                 listGET_OWNER_OF_NEXT_ENTRY( pxFirstTCB, pxList );\r
1836                 do\r
1837                 {\r
1838                         listGET_OWNER_OF_NEXT_ENTRY( pxNextTCB, pxList );\r
1839                         usStackRemaining = usTaskCheckFreeStackSpace( ( unsigned portCHAR * ) pxNextTCB->pxStack );\r
1840                         sprintf( pcStatusString, ( portCHAR * ) "%s\t\t%c\t%u\t%u\t%u\r\n", pxNextTCB->pcTaskName, cStatus, ( unsigned int ) pxNextTCB->uxPriority, usStackRemaining, ( unsigned int ) pxNextTCB->uxTCBNumber );\r
1841                         strcat( ( portCHAR * ) pcWriteBuffer, ( portCHAR * ) pcStatusString );\r
1842 \r
1843                 } while( pxNextTCB != pxFirstTCB );\r
1844         }\r
1845 \r
1846 #endif\r
1847 /*-----------------------------------------------------------*/\r
1848 \r
1849 #if ( ( configUSE_TRACE_FACILITY == 1 ) || ( INCLUDE_uxTaskGetStackHighWaterMark == 1 ) )\r
1850 \r
1851         unsigned portSHORT usTaskCheckFreeStackSpace( const unsigned portCHAR * pucStackByte )\r
1852         {\r
1853         register unsigned portSHORT usCount = 0;\r
1854 \r
1855                 while( *pucStackByte == tskSTACK_FILL_BYTE )\r
1856                 {\r
1857                         pucStackByte -= portSTACK_GROWTH;\r
1858                         usCount++;\r
1859                 }\r
1860 \r
1861                 usCount /= sizeof( portSTACK_TYPE );\r
1862 \r
1863                 return usCount;\r
1864         }\r
1865 \r
1866 #endif\r
1867 /*-----------------------------------------------------------*/\r
1868 \r
1869 #if ( INCLUDE_uxTaskGetStackHighWaterMark == 1 )\r
1870 \r
1871         unsigned portBASE_TYPE uxTaskGetStackHighWaterMark( xTaskHandle xTask )\r
1872         {\r
1873         tskTCB *pxTCB;\r
1874 \r
1875                 pxTCB = prvGetTCBFromHandle( xTask );\r
1876                 return usTaskCheckFreeStackSpace( ( unsigned portCHAR * ) pxTCB->pxStack );\r
1877         }\r
1878 \r
1879 #endif\r
1880 /*-----------------------------------------------------------*/\r
1881 \r
1882 #if ( ( INCLUDE_vTaskDelete == 1 ) || ( INCLUDE_vTaskCleanUpResources == 1 ) )\r
1883 \r
1884         static void prvDeleteTCB( tskTCB *pxTCB )\r
1885         {\r
1886                 /* Free up the memory allocated by the scheduler for the task.  It is up to\r
1887                 the task to free any memory allocated at the application level. */\r
1888                 vPortFree( pxTCB->pxStack );\r
1889                 vPortFree( pxTCB );\r
1890         }\r
1891 \r
1892 #endif\r
1893 \r
1894 \r
1895 /*-----------------------------------------------------------*/\r
1896 \r
1897 #if ( INCLUDE_xTaskGetCurrentTaskHandle == 1 )\r
1898 \r
1899         xTaskHandle xTaskGetCurrentTaskHandle( void )\r
1900         {\r
1901         xTaskHandle xReturn;\r
1902 \r
1903                 portENTER_CRITICAL();\r
1904                 {\r
1905                         xReturn = ( xTaskHandle ) pxCurrentTCB;\r
1906                 }\r
1907                 portEXIT_CRITICAL();\r
1908 \r
1909                 return xReturn;\r
1910         }\r
1911 \r
1912 #endif\r
1913 \r
1914 /*-----------------------------------------------------------*/\r
1915 \r
1916 #if ( INCLUDE_xTaskGetSchedulerState == 1 )\r
1917 \r
1918         portBASE_TYPE xTaskGetSchedulerState( void )\r
1919         {\r
1920         portBASE_TYPE xReturn;\r
1921         \r
1922                 if( xSchedulerRunning == pdFALSE )\r
1923                 {\r
1924                         xReturn = taskSCHEDULER_NOT_STARTED;\r
1925                 }\r
1926                 else\r
1927                 {\r
1928                         if( uxSchedulerSuspended == ( unsigned portBASE_TYPE ) pdFALSE )\r
1929                         {\r
1930                                 xReturn = taskSCHEDULER_RUNNING;\r
1931                         }\r
1932                         else\r
1933                         {\r
1934                                 xReturn = taskSCHEDULER_SUSPENDED;\r
1935                         }\r
1936                 }\r
1937                 \r
1938                 return xReturn;\r
1939         }\r
1940 \r
1941 #endif\r
1942 /*-----------------------------------------------------------*/\r
1943 \r
1944 #if ( configUSE_MUTEXES == 1 )\r
1945         \r
1946         void vTaskPriorityInherit( xTaskHandle * const pxMutexHolder )\r
1947         {\r
1948         tskTCB * const pxTCB = ( tskTCB * ) pxMutexHolder;\r
1949 \r
1950                 if( pxTCB->uxPriority < pxCurrentTCB->uxPriority )\r
1951                 {\r
1952                         /* Adjust the mutex holder state to account for its new priority. */\r
1953                         listSET_LIST_ITEM_VALUE( &( pxTCB->xEventListItem ), configMAX_PRIORITIES - ( portTickType ) pxCurrentTCB->uxPriority );\r
1954 \r
1955                         /* If the task being modified is in the ready state it will need to\r
1956                         be moved in to a new list. */\r
1957                         if( listIS_CONTAINED_WITHIN( &( pxReadyTasksLists[ pxTCB->uxPriority ] ), &( pxTCB->xGenericListItem ) ) )\r
1958                         {\r
1959                                 vListRemove( &( pxTCB->xGenericListItem ) );\r
1960 \r
1961                                 /* Inherit the priority before being moved into the new list. */\r
1962                                 pxTCB->uxPriority = pxCurrentTCB->uxPriority;\r
1963                                 prvAddTaskToReadyQueue( pxTCB );\r
1964                         }\r
1965                         else\r
1966                         {\r
1967                                 /* Just inherit the priority. */\r
1968                                 pxTCB->uxPriority = pxCurrentTCB->uxPriority;\r
1969                         }\r
1970                 }\r
1971         }\r
1972 \r
1973 #endif\r
1974 /*-----------------------------------------------------------*/\r
1975 \r
1976 #if ( configUSE_MUTEXES == 1 )  \r
1977 \r
1978         void vTaskPriorityDisinherit( xTaskHandle * const pxMutexHolder )\r
1979         {\r
1980         tskTCB * const pxTCB = ( tskTCB * ) pxMutexHolder;\r
1981 \r
1982                 if( pxMutexHolder != NULL )\r
1983                 {\r
1984                         if( pxTCB->uxPriority != pxTCB->uxBasePriority )\r
1985                         {\r
1986                                 /* We must be the running task to be able to give the mutex back.\r
1987                                 Remove ourselves from the ready list we currently appear in. */\r
1988                                 vListRemove( &( pxTCB->xGenericListItem ) );\r
1989 \r
1990                                 /* Disinherit the priority before adding ourselves into the new\r
1991                                 ready list. */\r
1992                                 pxTCB->uxPriority = pxTCB->uxBasePriority;\r
1993                                 listSET_LIST_ITEM_VALUE( &( pxTCB->xEventListItem ), configMAX_PRIORITIES - ( portTickType ) pxTCB->uxPriority );\r
1994                                 prvAddTaskToReadyQueue( pxTCB );\r
1995                         }\r
1996                 }\r
1997         }\r
1998 \r
1999 #endif\r
2000 /*-----------------------------------------------------------*/\r
2001 \r
2002 #if ( portCRITICAL_NESTING_IN_TCB == 1 )\r
2003 \r
2004         void vTaskEnterCritical( void )\r
2005         {\r
2006                 portDISABLE_INTERRUPTS();\r
2007 \r
2008                 if( xSchedulerRunning != pdFALSE )\r
2009                 {\r
2010                         pxCurrentTCB->uxCriticalNesting++;\r
2011                 }\r
2012         }\r
2013 \r
2014 #endif\r
2015 /*-----------------------------------------------------------*/\r
2016 \r
2017 #if ( portCRITICAL_NESTING_IN_TCB == 1 )\r
2018 \r
2019 void vTaskExitCritical( void )\r
2020 {\r
2021         if( xSchedulerRunning != pdFALSE )\r
2022         {\r
2023                 if( pxCurrentTCB->uxCriticalNesting > 0 )\r
2024                 {\r
2025                         pxCurrentTCB->uxCriticalNesting--;\r
2026 \r
2027                         if( pxCurrentTCB->uxCriticalNesting == 0 )\r
2028                         {\r
2029                                 portENABLE_INTERRUPTS();\r
2030                         }\r
2031                 }\r
2032         }\r
2033 }\r
2034 \r
2035 #endif\r
2036 /*-----------------------------------------------------------*/\r
2037 \r
2038 \r
2039         \r
2040 \r