git.sur5r.net Git - freertos/blob - Source/tasks.c

   1 /*\r
   2         FreeRTOS.org V5.1.2 - Copyright (C) 2003-2009 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     * Get the FreeRTOS eBook!  See http://www.FreeRTOS.org/Documentation      *\r
  30         *                                                                         *\r
  31         * This is a concise, step by step, 'hands on' guide that describes both   *\r
  32         * general multitasking concepts and FreeRTOS specifics. It presents and   *\r
  33         * explains numerous examples that are written using the FreeRTOS API.     *\r
  34         * Full source code for all the examples is provided in an accompanying    *\r
  35         * .zip file.                                                              *\r
  36     *                                                                         *\r
  37     ***************************************************************************\r
  38     ***************************************************************************\r
  39 \r
  40         Please ensure to read the configuration and relevant port sections of the\r
  41         online documentation.\r
  42 \r
  43         http://www.FreeRTOS.org - Documentation, latest information, license and \r
  44         contact details.\r
  45 \r
  46         http://www.SafeRTOS.com - A version that is certified for use in safety \r
  47         critical systems.\r
  48 \r
  49         http://www.OpenRTOS.com - Commercial support, development, porting, \r
  50         licensing and training services.\r
  51 */\r
  52 \r
  53 \r
  54 #include <stdio.h>\r
  55 #include <stdlib.h>\r
  56 #include <string.h>\r
  57 \r
  58 #include "FreeRTOS.h"\r
  59 #include "task.h"\r
  60 #include "StackMacros.h"\r
  61 \r
  62 /*\r
  63  * Macro to define the amount of stack available to the idle task.\r
  64  */\r
  65 #define tskIDLE_STACK_SIZE      configMINIMAL_STACK_SIZE\r
  66 \r
  67 /*\r
  68  * Task control block.  A task control block (TCB) is allocated to each task,\r
  69  * and stores the context of the task.\r
  70  */\r
  71 typedef struct tskTaskControlBlock\r
  72 {\r
  73         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
  74         xListItem                               xGenericListItem;       /*< List item used to place the TCB in ready and blocked queues. */\r
  75         xListItem                               xEventListItem;         /*< List item used to place the TCB in event lists. */\r
  76         unsigned portBASE_TYPE  uxPriority;                     /*< The priority of the task where 0 is the lowest priority. */\r
  77         portSTACK_TYPE                  *pxStack;                       /*< Points to the start of the stack. */\r
  78         signed portCHAR                 pcTaskName[ configMAX_TASK_NAME_LEN ];/*< Descriptive name given to the task when created.  Facilitates debugging only. */\r
  79 \r
  80         #if ( portSTACK_GROWTH > 0 )\r
  81                 portSTACK_TYPE *pxEndOfStack;                   /*< Used for stack overflow checking on architectures where the stack grows up from low memory. */\r
  82         #endif\r
  83 \r
  84         #if ( portCRITICAL_NESTING_IN_TCB == 1 )\r
  85                 unsigned portBASE_TYPE uxCriticalNesting;\r
  86         #endif\r
  87 \r
  88         #if ( configUSE_TRACE_FACILITY == 1 )\r
  89                 unsigned portBASE_TYPE  uxTCBNumber;            /*< This is used for tracing the scheduler and making debugging easier only. */\r
  90         #endif  \r
  91                 \r
  92         #if ( configUSE_MUTEXES == 1 )\r
  93                 unsigned portBASE_TYPE uxBasePriority;\r
  94         #endif\r
  95 \r
  96         #if ( configUSE_APPLICATION_TASK_TAG == 1 )\r
  97                 pdTASK_HOOK_CODE pxTaskTag;\r
  98         #endif\r
  99                 \r
 100 } tskTCB;\r
 101 \r
 102 /*\r
 103  * Some kernel aware debuggers require data to be viewed to be global, rather\r
 104  * than file scope.\r
 105  */\r
 106 #ifdef portREMOVE_STATIC_QUALIFIER\r
 107         #define static\r
 108 #endif\r
 109 \r
 110 /*lint -e956 */\r
 111 \r
 112 tskTCB * volatile pxCurrentTCB = NULL;                                  \r
 113 \r
 114 /* Lists for ready and blocked tasks. --------------------*/\r
 115 \r
 116 static xList pxReadyTasksLists[ configMAX_PRIORITIES ]; /*< Prioritised ready tasks. */\r
 117 static xList xDelayedTaskList1;                                                 /*< Delayed tasks. */\r
 118 static xList xDelayedTaskList2;                                                 /*< Delayed tasks (two lists are used - one for delays that have overflowed the current tick count. */\r
 119 static xList * volatile pxDelayedTaskList;                              /*< Points to the delayed task list currently being used. */\r
 120 static xList * volatile pxOverflowDelayedTaskList;              /*< Points to the delayed task list currently being used to hold tasks that have overflowed the current tick count. */\r
 121 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
 122 \r
 123 #if ( INCLUDE_vTaskDelete == 1 )\r
 124 \r
 125         static volatile xList xTasksWaitingTermination;         /*< Tasks that have been deleted - but the their memory not yet freed. */\r
 126         static volatile unsigned portBASE_TYPE uxTasksDeleted = ( unsigned portBASE_TYPE ) 0;\r
 127 \r
 128 #endif\r
 129 \r
 130 #if ( INCLUDE_vTaskSuspend == 1 )\r
 131 \r
 132         static xList xSuspendedTaskList;                                        /*< Tasks that are currently suspended. */\r
 133 \r
 134 #endif\r
 135 \r
 136 /* File private variables. --------------------------------*/\r
 137 static volatile unsigned portBASE_TYPE uxCurrentNumberOfTasks   = ( unsigned portBASE_TYPE ) 0;\r
 138 static volatile portTickType xTickCount                                                 = ( portTickType ) 0;\r
 139 static unsigned portBASE_TYPE uxTopUsedPriority                                 = tskIDLE_PRIORITY;\r
 140 static volatile unsigned portBASE_TYPE uxTopReadyPriority               = tskIDLE_PRIORITY;\r
 141 static volatile signed portBASE_TYPE xSchedulerRunning                  = pdFALSE;\r
 142 static volatile unsigned portBASE_TYPE uxSchedulerSuspended             = ( unsigned portBASE_TYPE ) pdFALSE;\r
 143 static volatile unsigned portBASE_TYPE uxMissedTicks                    = ( unsigned portBASE_TYPE ) 0;\r
 144 static volatile portBASE_TYPE xMissedYield                                              = ( portBASE_TYPE ) pdFALSE;\r
 145 static volatile portBASE_TYPE xNumOfOverflows                                   = ( portBASE_TYPE ) 0;\r
 146 #if ( configUSE_TRACE_FACILITY == 1 )\r
 147         static unsigned portBASE_TYPE uxTaskNumber = 0; /*lint !e956 Static is deliberate - this is guarded before use. */\r
 148 #endif\r
 149 \r
 150 /* Debugging and trace facilities private variables and macros. ------------*/\r
 151 \r
 152 /*\r
 153  * The value used to fill the stack of a task when the task is created.  This\r
 154  * is used purely for checking the high water mark for tasks.\r
 155  */\r
 156 #define tskSTACK_FILL_BYTE      ( 0xa5 )\r
 157 \r
 158 /*\r
 159  * Macros used by vListTask to indicate which state a task is in.\r
 160  */\r
 161 #define tskBLOCKED_CHAR         ( ( signed portCHAR ) 'B' )\r
 162 #define tskREADY_CHAR           ( ( signed portCHAR ) 'R' )\r
 163 #define tskDELETED_CHAR         ( ( signed portCHAR ) 'D' )\r
 164 #define tskSUSPENDED_CHAR       ( ( signed portCHAR ) 'S' )\r
 165 \r
 166 /*\r
 167  * Macros and private variables used by the trace facility.\r
 168  */\r
 169 #if ( configUSE_TRACE_FACILITY == 1 )\r
 170 \r
 171         #define tskSIZE_OF_EACH_TRACE_LINE                      ( ( unsigned portLONG ) ( sizeof( unsigned portLONG ) + sizeof( unsigned portLONG ) ) )\r
 172         static volatile signed portCHAR * volatile pcTraceBuffer;\r
 173         static signed portCHAR *pcTraceBufferStart;\r
 174         static signed portCHAR *pcTraceBufferEnd;\r
 175         static signed portBASE_TYPE xTracing = pdFALSE;\r
 176         static unsigned portBASE_TYPE uxPreviousTask = 255;\r
 177         static portCHAR pcStatusString[ 50 ];\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                         if( uxPreviousTask != pxCurrentTCB->uxTCBNumber )                                                                               \\r
 195                         {                                                                                                                                                                               \\r
 196                                 if( ( pcTraceBuffer + tskSIZE_OF_EACH_TRACE_LINE ) < pcTraceBufferEnd )                         \\r
 197                                 {                                                                                                                                                                       \\r
 198                                         uxPreviousTask = pxCurrentTCB->uxTCBNumber;                                                                             \\r
 199                                         *( unsigned portLONG * ) pcTraceBuffer = ( unsigned portLONG ) xTickCount;              \\r
 200                                         pcTraceBuffer += sizeof( unsigned portLONG );                                                                   \\r
 201                                         *( unsigned portLONG * ) pcTraceBuffer = ( unsigned portLONG ) uxPreviousTask;  \\r
 202                                         pcTraceBuffer += sizeof( unsigned portLONG );                                                                   \\r
 203                                 }                                                                                                                                                                       \\r
 204                                 else                                                                                                                                                            \\r
 205                                 {                                                                                                                                                                       \\r
 206                                         xTracing = pdFALSE;                                                                                                                             \\r
 207                                 }                                                                                                                                                                       \\r
 208                         }                                                                                                                                                                               \\r
 209                 }                                                                                                                                                                                       \\r
 210         }\r
 211 \r
 212 #else\r
 213 \r
 214         #define vWriteTraceToBuffer()\r
 215 \r
 216 #endif\r
 217 /*-----------------------------------------------------------*/\r
 218 \r
 219 /*\r
 220  * Place the task represented by pxTCB into the appropriate ready queue for\r
 221  * the task.  It is inserted at the end of the list.  One quirk of this is\r
 222  * that if the task being inserted is at the same priority as the currently\r
 223  * executing task, then it will only be rescheduled after the currently\r
 224  * executing task has been rescheduled.\r
 225  */\r
 226 #define prvAddTaskToReadyQueue( pxTCB )                                                                                                                                                 \\r
 227 {                                                                                                                                                                                                                               \\r
 228         if( pxTCB->uxPriority > uxTopReadyPriority )                                                                                                                            \\r
 229         {                                                                                                                                                                                                                       \\r
 230                 uxTopReadyPriority = pxTCB->uxPriority;                                                                                                                                 \\r
 231         }                                                                                                                                                                                                                       \\r
 232         vListInsertEnd( ( xList * ) &( pxReadyTasksLists[ pxTCB->uxPriority ] ), &( pxTCB->xGenericListItem ) );        \\r
 233 }\r
 234 /*-----------------------------------------------------------*/         \r
 235 \r
 236 /*\r
 237  * Macro that looks at the list of tasks that are currently delayed to see if\r
 238  * any require waking.\r
 239  *\r
 240  * Tasks are stored in the queue in the order of their wake time - meaning\r
 241  * once one tasks has been found whose timer has not expired we need not look\r
 242  * any further down the list.\r
 243  */\r
 244 #define prvCheckDelayedTasks()                                                                                                                                                                          \\r
 245 {                                                                                                                                                                                                                                       \\r
 246 register tskTCB *pxTCB;                                                                                                                                                                                         \\r
 247                                                                                                                                                                                                                                         \\r
 248         while( ( pxTCB = ( tskTCB * ) listGET_OWNER_OF_HEAD_ENTRY( pxDelayedTaskList ) ) != NULL )                                              \\r
 249         {                                                                                                                                                                                                                               \\r
 250                 if( xTickCount < listGET_LIST_ITEM_VALUE( &( pxTCB->xGenericListItem ) ) )                                                                      \\r
 251                 {                                                                                                                                                                                                                       \\r
 252                         break;                                                                                                                                                                                                  \\r
 253                 }                                                                                                                                                                                                                       \\r
 254                 vListRemove( &( pxTCB->xGenericListItem ) );                                                                                                                            \\r
 255                 /* Is the task waiting on an event also? */                                                                                                                                     \\r
 256                 if( pxTCB->xEventListItem.pvContainer )                                                                                                                                         \\r
 257                 {                                                                                                                                                                                                                       \\r
 258                         vListRemove( &( pxTCB->xEventListItem ) );                                                                                                                              \\r
 259                 }                                                                                                                                                                                                                       \\r
 260                 prvAddTaskToReadyQueue( pxTCB );                                                                                                                                                        \\r
 261         }                                                                                                                                                                                                                               \\r
 262 }\r
 263 /*-----------------------------------------------------------*/\r
 264 \r
 265 /*\r
 266  * Several functions take an xTaskHandle parameter that can optionally be NULL,\r
 267  * where NULL is used to indicate that the handle of the currently executing\r
 268  * task should be used in place of the parameter.  This macro simply checks to\r
 269  * see if the parameter is NULL and returns a pointer to the appropriate TCB.\r
 270  */\r
 271 #define prvGetTCBFromHandle( pxHandle ) ( ( pxHandle == NULL ) ? ( tskTCB * ) pxCurrentTCB : ( tskTCB * ) pxHandle )\r
 272 \r
 273 \r
 274 /* File private functions. --------------------------------*/\r
 275 \r
 276 /*\r
 277  * Utility to ready a TCB for a given task.  Mainly just copies the parameters\r
 278  * into the TCB structure.\r
 279  */\r
 280 static void prvInitialiseTCBVariables( tskTCB *pxTCB, const signed portCHAR * const pcName, unsigned portBASE_TYPE uxPriority );\r
 281 \r
 282 /*\r
 283  * Utility to ready all the lists used by the scheduler.  This is called\r
 284  * automatically upon the creation of the first task.\r
 285  */\r
 286 static void prvInitialiseTaskLists( void );\r
 287 \r
 288 /*\r
 289  * The idle task, which as all tasks is implemented as a never ending loop.\r
 290  * The idle task is automatically created and added to the ready lists upon\r
 291  * creation of the first user task.\r
 292  *\r
 293  * The portTASK_FUNCTION_PROTO() macro is used to allow port/compiler specific\r
 294  * language extensions.  The equivalent prototype for this function is:\r
 295  *\r
 296  * void prvIdleTask( void *pvParameters );\r
 297  *\r
 298  */\r
 299 static portTASK_FUNCTION_PROTO( prvIdleTask, pvParameters );\r
 300 \r
 301 /*\r
 302  * Utility to free all memory allocated by the scheduler to hold a TCB,\r
 303  * including the stack pointed to by the TCB.\r
 304  *\r
 305  * This does not free memory allocated by the task itself (i.e. memory\r
 306  * allocated by calls to pvPortMalloc from within the tasks application code).\r
 307  */\r
 308 #if ( ( INCLUDE_vTaskDelete == 1 ) || ( INCLUDE_vTaskCleanUpResources == 1 ) )\r
 309         static void prvDeleteTCB( tskTCB *pxTCB );\r
 310 #endif\r
 311 \r
 312 /*\r
 313  * Used only by the idle task.  This checks to see if anything has been placed\r
 314  * in the list of tasks waiting to be deleted.  If so the task is cleaned up\r
 315  * and its TCB deleted.\r
 316  */\r
 317 static void prvCheckTasksWaitingTermination( void );\r
 318 \r
 319 /*\r
 320  * Allocates memory from the heap for a TCB and associated stack.  Checks the\r
 321  * allocation was successful.\r
 322  */\r
 323 static tskTCB *prvAllocateTCBAndStack( unsigned portSHORT usStackDepth );\r
 324 \r
 325 /*\r
 326  * Called from vTaskList.  vListTasks details all the tasks currently under\r
 327  * control of the scheduler.  The tasks may be in one of a number of lists.\r
 328  * prvListTaskWithinSingleList accepts a list and details the tasks from\r
 329  * within just that list.\r
 330  *\r
 331  * THIS FUNCTION IS INTENDED FOR DEBUGGING ONLY, AND SHOULD NOT BE CALLED FROM\r
 332  * NORMAL APPLICATION CODE.\r
 333  */\r
 334 #if ( configUSE_TRACE_FACILITY == 1 )\r
 335 \r
 336         static void prvListTaskWithinSingleList( const signed portCHAR *pcWriteBuffer, xList *pxList, signed portCHAR cStatus );\r
 337 \r
 338 #endif\r
 339 \r
 340 /*\r
 341  * When a task is created, the stack of the task is filled with a known value.\r
 342  * This function determines the 'high water mark' of the task stack by\r
 343  * determining how much of the stack remains at the original preset value.\r
 344  */\r
 345 #if ( ( configUSE_TRACE_FACILITY == 1 ) || ( INCLUDE_uxTaskGetStackHighWaterMark == 1 ) )\r
 346 \r
 347         unsigned portSHORT usTaskCheckFreeStackSpace( const unsigned portCHAR * pucStackByte );\r
 348 \r
 349 #endif\r
 350 \r
 351 \r
 352 /*lint +e956 */\r
 353 \r
 354 \r
 355 \r
 356 /*-----------------------------------------------------------\r
 357  * TASK CREATION API documented in task.h\r
 358  *----------------------------------------------------------*/\r
 359 \r
 360 signed portBASE_TYPE xTaskCreate( pdTASK_CODE pvTaskCode, const signed portCHAR * const pcName, unsigned portSHORT usStackDepth, void *pvParameters, unsigned portBASE_TYPE uxPriority, xTaskHandle *pxCreatedTask )\r
 361 {\r
 362 signed portBASE_TYPE xReturn;\r
 363 tskTCB * pxNewTCB;\r
 364 \r
 365         /* Allocate the memory required by the TCB and stack for the new task.\r
 366         checking that the allocation was successful. */\r
 367         pxNewTCB = prvAllocateTCBAndStack( usStackDepth );\r
 368 \r
 369         if( pxNewTCB != NULL )\r
 370         {               \r
 371                 portSTACK_TYPE *pxTopOfStack;\r
 372 \r
 373                 /* Setup the newly allocated TCB with the initial state of the task. */\r
 374                 prvInitialiseTCBVariables( pxNewTCB, pcName, uxPriority );\r
 375 \r
 376                 /* Calculate the top of stack address.  This depends on whether the\r
 377                 stack grows from high memory to low (as per the 80x86) or visa versa.\r
 378                 portSTACK_GROWTH is used to make the result positive or negative as\r
 379                 required by the port. */\r
 380                 #if portSTACK_GROWTH < 0\r
 381                 {\r
 382                         pxTopOfStack = pxNewTCB->pxStack + ( usStackDepth - 1 );\r
 383                 }\r
 384                 #else\r
 385                 {\r
 386                         pxTopOfStack = pxNewTCB->pxStack;       \r
 387 \r
 388                         /* If we want to use stack checking on architectures that use\r
 389                         a positive stack growth direction then we also need to store the\r
 390                         other extreme of the stack space. */\r
 391                         pxNewTCB->pxEndOfStack = pxNewTCB->pxStack + ( usStackDepth - 1 );\r
 392                 }\r
 393                 #endif\r
 394 \r
 395                 /* Initialize the TCB stack to look as if the task was already running,\r
 396                 but had been interrupted by the scheduler.  The return address is set\r
 397                 to the start of the task function. Once the stack has been initialised\r
 398                 the     top of stack variable is updated. */\r
 399                 pxNewTCB->pxTopOfStack = pxPortInitialiseStack( pxTopOfStack, pvTaskCode, pvParameters );\r
 400 \r
 401                 /* We are going to manipulate the task queues to add this task to a\r
 402                 ready list, so must make sure no interrupts occur. */\r
 403                 portENTER_CRITICAL();\r
 404                 {\r
 405                         uxCurrentNumberOfTasks++;\r
 406                         if( uxCurrentNumberOfTasks == ( unsigned portBASE_TYPE ) 1 )\r
 407                         {\r
 408                                 /* As this is the first task it must also be the current task. */\r
 409                                 pxCurrentTCB =  pxNewTCB;\r
 410 \r
 411                                 /* This is the first task to be created so do the preliminary\r
 412                                 initialisation required.  We will not recover if this call\r
 413                                 fails, but we will report the failure. */\r
 414                                 prvInitialiseTaskLists();\r
 415                         }\r
 416                         else\r
 417                         {       \r
 418                                 /* If the scheduler is not already running, make this task the\r
 419                                 current task if it is the highest priority task to be created\r
 420                                 so far. */\r
 421                                 if( xSchedulerRunning == pdFALSE )\r
 422                                 {\r
 423                                         if( pxCurrentTCB->uxPriority <= uxPriority )\r
 424                                         {\r
 425                                                 pxCurrentTCB = pxNewTCB;        \r
 426                                         }\r
 427                                 }\r
 428                         }                               \r
 429 \r
 430                         /* Remember the top priority to make context switching faster.  Use\r
 431                         the priority in pxNewTCB as this has been capped to a valid value. */\r
 432                         if( pxNewTCB->uxPriority > uxTopUsedPriority )\r
 433                         {\r
 434                                 uxTopUsedPriority = pxNewTCB->uxPriority;\r
 435                         }\r
 436 \r
 437                         #if ( configUSE_TRACE_FACILITY == 1 )\r
 438                         {\r
 439                                 /* Add a counter into the TCB for tracing only. */\r
 440                                 pxNewTCB->uxTCBNumber = uxTaskNumber;\r
 441                                 uxTaskNumber++;\r
 442                         }\r
 443                         #endif\r
 444 \r
 445                         prvAddTaskToReadyQueue( pxNewTCB );\r
 446 \r
 447                         xReturn = pdPASS;\r
 448                         traceTASK_CREATE( pxNewTCB );\r
 449                 }\r
 450                 portEXIT_CRITICAL();\r
 451         }\r
 452         else\r
 453         {\r
 454                 xReturn = errCOULD_NOT_ALLOCATE_REQUIRED_MEMORY;\r
 455                 traceTASK_CREATE_FAILED( pxNewTCB );\r
 456         }\r
 457 \r
 458         if( xReturn == pdPASS )\r
 459         {\r
 460                 if( ( void * ) pxCreatedTask != NULL )\r
 461                 {\r
 462                         /* Pass the TCB out - in an anonymous way.  The calling function/\r
 463                         task can use this as a handle to delete the task later if\r
 464                         required.*/\r
 465                         *pxCreatedTask = ( xTaskHandle ) pxNewTCB;\r
 466                 }\r
 467 \r
 468                 if( xSchedulerRunning != pdFALSE )\r
 469                 {\r
 470                         /* If the created task is of a higher priority than the current task\r
 471                         then it should run now. */\r
 472                         if( pxCurrentTCB->uxPriority < uxPriority )\r
 473                         {\r
 474                                 taskYIELD();\r
 475                         }\r
 476                 }\r
 477         }\r
 478 \r
 479         return xReturn;\r
 480 }\r
 481 /*-----------------------------------------------------------*/\r
 482 \r
 483 #if ( INCLUDE_vTaskDelete == 1 )\r
 484 \r
 485         void vTaskDelete( xTaskHandle pxTaskToDelete )\r
 486         {\r
 487         tskTCB *pxTCB;\r
 488 \r
 489                 taskENTER_CRITICAL();\r
 490                 {\r
 491                         /* Ensure a yield is performed if the current task is being\r
 492                         deleted. */\r
 493                         if( pxTaskToDelete == pxCurrentTCB )\r
 494                         {\r
 495                                 pxTaskToDelete = NULL;\r
 496                         }\r
 497 \r
 498                         /* If null is passed in here then we are deleting ourselves. */\r
 499                         pxTCB = prvGetTCBFromHandle( pxTaskToDelete );\r
 500 \r
 501                         traceTASK_DELETE( pxTCB );\r
 502 \r
 503                         /* Remove task from the ready list and place in the     termination list.\r
 504                         This will stop the task from be scheduled.  The idle task will check\r
 505                         the termination list and free up any memory allocated by the\r
 506                         scheduler for the TCB and stack. */\r
 507                         vListRemove( &( pxTCB->xGenericListItem ) );\r
 508 \r
 509                         /* Is the task waiting on an event also? */                                                                                             \r
 510                         if( pxTCB->xEventListItem.pvContainer )\r
 511                         {\r
 512                                 vListRemove( &( pxTCB->xEventListItem ) );\r
 513                         }\r
 514 \r
 515                         vListInsertEnd( ( xList * ) &xTasksWaitingTermination, &( pxTCB->xGenericListItem ) );\r
 516 \r
 517                         /* Increment the ucTasksDeleted variable so the idle task knows\r
 518                         there is a task that has been deleted and that it should therefore\r
 519                         check the xTasksWaitingTermination list. */\r
 520                         ++uxTasksDeleted;\r
 521                 }\r
 522                 taskEXIT_CRITICAL();\r
 523 \r
 524                 /* Force a reschedule if we have just deleted the current task. */\r
 525                 if( xSchedulerRunning != pdFALSE )\r
 526                 {\r
 527                         if( ( void * ) pxTaskToDelete == NULL )\r
 528                         {\r
 529                                 taskYIELD();\r
 530                         }\r
 531                 }\r
 532         }\r
 533 \r
 534 #endif\r
 535 \r
 536 \r
 537 \r
 538 \r
 539 \r
 540 \r
 541 /*-----------------------------------------------------------\r
 542  * TASK CONTROL API documented in task.h\r
 543  *----------------------------------------------------------*/\r
 544 \r
 545 #if ( INCLUDE_vTaskDelayUntil == 1 )\r
 546 \r
 547         void vTaskDelayUntil( portTickType * const pxPreviousWakeTime, portTickType xTimeIncrement )\r
 548         {\r
 549         portTickType xTimeToWake;\r
 550         portBASE_TYPE xAlreadyYielded, xShouldDelay = pdFALSE;\r
 551 \r
 552                 vTaskSuspendAll();\r
 553                 {\r
 554                         /* Generate the tick time at which the task wants to wake. */\r
 555                         xTimeToWake = *pxPreviousWakeTime + xTimeIncrement;\r
 556 \r
 557                         if( xTickCount < *pxPreviousWakeTime )\r
 558                         {\r
 559                                 /* The tick count has overflowed since this function was\r
 560                                 lasted called.  In this case the only time we should ever\r
 561                                 actually delay is if the wake time has also     overflowed,\r
 562                                 and the wake time is greater than the tick time.  When this\r
 563                                 is the case it is as if neither time had overflowed. */\r
 564                                 if( ( xTimeToWake < *pxPreviousWakeTime ) && ( xTimeToWake > xTickCount ) )\r
 565                                 {\r
 566                                         xShouldDelay = pdTRUE;\r
 567                                 }\r
 568                         }\r
 569                         else\r
 570                         {\r
 571                                 /* The tick time has not overflowed.  In this case we will\r
 572                                 delay if either the wake time has overflowed, and/or the\r
 573                                 tick time is less than the wake time. */\r
 574                                 if( ( xTimeToWake < *pxPreviousWakeTime ) || ( xTimeToWake > xTickCount ) )\r
 575                                 {\r
 576                                         xShouldDelay = pdTRUE;\r
 577                                 }\r
 578                         }\r
 579 \r
 580                         /* Update the wake time ready for the next call. */\r
 581                         *pxPreviousWakeTime = xTimeToWake;\r
 582 \r
 583                         if( xShouldDelay )\r
 584                         {\r
 585                                 traceTASK_DELAY_UNTIL();\r
 586 \r
 587                                 /* We must remove ourselves from the ready list before adding\r
 588                                 ourselves to the blocked list as the same list item is used for\r
 589                                 both lists. */\r
 590                                 vListRemove( ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );\r
 591 \r
 592                                 /* The list item will be inserted in wake time order. */\r
 593                                 listSET_LIST_ITEM_VALUE( &( pxCurrentTCB->xGenericListItem ), xTimeToWake );\r
 594 \r
 595                                 if( xTimeToWake < xTickCount )\r
 596                                 {\r
 597                                         /* Wake time has overflowed.  Place this item in the\r
 598                                         overflow list. */\r
 599                                         vListInsert( ( xList * ) pxOverflowDelayedTaskList, ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );\r
 600                                 }\r
 601                                 else\r
 602                                 {\r
 603                                         /* The wake time has not overflowed, so we can use the\r
 604                                         current block list. */\r
 605                                         vListInsert( ( xList * ) pxDelayedTaskList, ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );\r
 606                                 }\r
 607                         }\r
 608                 }\r
 609                 xAlreadyYielded = xTaskResumeAll();\r
 610 \r
 611                 /* Force a reschedule if xTaskResumeAll has not already done so, we may\r
 612                 have put ourselves to sleep. */\r
 613                 if( !xAlreadyYielded )\r
 614                 {\r
 615                         taskYIELD();\r
 616                 }\r
 617         }       \r
 618         \r
 619 #endif\r
 620 /*-----------------------------------------------------------*/\r
 621 \r
 622 #if ( INCLUDE_vTaskDelay == 1 )\r
 623 \r
 624         void vTaskDelay( portTickType xTicksToDelay )\r
 625         {\r
 626         portTickType xTimeToWake;\r
 627         signed portBASE_TYPE xAlreadyYielded = pdFALSE;\r
 628 \r
 629                 /* A delay time of zero just forces a reschedule. */\r
 630                 if( xTicksToDelay > ( portTickType ) 0 )\r
 631                 {\r
 632                         vTaskSuspendAll();\r
 633                         {\r
 634                                 traceTASK_DELAY();\r
 635 \r
 636                                 /* A task that is removed from the event list while the\r
 637                                 scheduler is suspended will not get placed in the ready\r
 638                                 list or removed from the blocked list until the scheduler\r
 639                                 is resumed.\r
 640                                 \r
 641                                 This task cannot be in an event list as it is the currently\r
 642                                 executing task. */\r
 643 \r
 644                                 /* Calculate the time to wake - this may overflow but this is\r
 645                                 not a problem. */\r
 646                                 xTimeToWake = xTickCount + xTicksToDelay;\r
 647 \r
 648                                 /* We must remove ourselves from the ready list before adding\r
 649                                 ourselves to the blocked list as the same list item is used for\r
 650                                 both lists. */\r
 651                                 vListRemove( ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );\r
 652 \r
 653                                 /* The list item will be inserted in wake time order. */\r
 654                                 listSET_LIST_ITEM_VALUE( &( pxCurrentTCB->xGenericListItem ), xTimeToWake );\r
 655 \r
 656                                 if( xTimeToWake < xTickCount )\r
 657                                 {\r
 658                                         /* Wake time has overflowed.  Place this item in the\r
 659                                         overflow list. */\r
 660                                         vListInsert( ( xList * ) pxOverflowDelayedTaskList, ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );\r
 661                                 }\r
 662                                 else\r
 663                                 {\r
 664                                         /* The wake time has not overflowed, so we can use the\r
 665                                         current block list. */\r
 666                                         vListInsert( ( xList * ) pxDelayedTaskList, ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );\r
 667                                 }\r
 668                         }\r
 669                         xAlreadyYielded = xTaskResumeAll();\r
 670                 }\r
 671                 \r
 672                 /* Force a reschedule if xTaskResumeAll has not already done so, we may\r
 673                 have put ourselves to sleep. */\r
 674                 if( !xAlreadyYielded )\r
 675                 {\r
 676                         taskYIELD();\r
 677                 }\r
 678         }\r
 679         \r
 680 #endif\r
 681 /*-----------------------------------------------------------*/\r
 682 \r
 683 #if ( INCLUDE_uxTaskPriorityGet == 1 )\r
 684 \r
 685         unsigned portBASE_TYPE uxTaskPriorityGet( xTaskHandle pxTask )\r
 686         {\r
 687         tskTCB *pxTCB;\r
 688         unsigned portBASE_TYPE uxReturn;\r
 689 \r
 690                 taskENTER_CRITICAL();\r
 691                 {\r
 692                         /* If null is passed in here then we are changing the\r
 693                         priority of the calling function. */\r
 694                         pxTCB = prvGetTCBFromHandle( pxTask );\r
 695                         uxReturn = pxTCB->uxPriority;\r
 696                 }\r
 697                 taskEXIT_CRITICAL();\r
 698 \r
 699                 return uxReturn;\r
 700         }\r
 701 \r
 702 #endif\r
 703 /*-----------------------------------------------------------*/\r
 704 \r
 705 #if ( INCLUDE_vTaskPrioritySet == 1 )\r
 706 \r
 707         void vTaskPrioritySet( xTaskHandle pxTask, unsigned portBASE_TYPE uxNewPriority )\r
 708         {\r
 709         tskTCB *pxTCB;\r
 710         unsigned portBASE_TYPE uxCurrentPriority, xYieldRequired = pdFALSE;\r
 711 \r
 712                 /* Ensure the new priority is valid. */\r
 713                 if( uxNewPriority >= configMAX_PRIORITIES )\r
 714                 {\r
 715                         uxNewPriority = configMAX_PRIORITIES - 1;\r
 716                 }\r
 717 \r
 718                 taskENTER_CRITICAL();\r
 719                 {\r
 720                         if( pxTask == pxCurrentTCB )\r
 721                         {\r
 722                                 pxTask = NULL;\r
 723                         }\r
 724 \r
 725                         /* If null is passed in here then we are changing the\r
 726                         priority of the calling function. */\r
 727                         pxTCB = prvGetTCBFromHandle( pxTask );\r
 728                         \r
 729                         traceTASK_PRIORITY_SET( pxTask, uxNewPriority );\r
 730 \r
 731                         #if ( configUSE_MUTEXES == 1 )\r
 732                         {\r
 733                                 uxCurrentPriority = pxTCB->uxBasePriority;\r
 734                         }\r
 735                         #else\r
 736                         {\r
 737                                 uxCurrentPriority = pxTCB->uxPriority;\r
 738                         }\r
 739                         #endif\r
 740 \r
 741                         if( uxCurrentPriority != uxNewPriority )\r
 742                         {\r
 743                                 /* The priority change may have readied a task of higher\r
 744                                 priority than the calling task. */\r
 745                                 if( uxNewPriority > uxCurrentPriority )\r
 746                                 {\r
 747                                         if( pxTask != NULL )\r
 748                                         {\r
 749                                                 /* The priority of another task is being raised.  If we\r
 750                                                 were raising the priority of the currently running task\r
 751                                                 there would be no need to switch as it must have already\r
 752                                                 been the highest priority task. */\r
 753                                                 xYieldRequired = pdTRUE;\r
 754                                         }\r
 755                                 }\r
 756                                 else if( pxTask == NULL )\r
 757                                 {\r
 758                                         /* Setting our own priority down means there may now be another\r
 759                                         task of higher priority that is ready to execute. */\r
 760                                         xYieldRequired = pdTRUE;\r
 761                                 }\r
 762                         \r
 763                                 \r
 764 \r
 765                                 #if ( configUSE_MUTEXES == 1 )\r
 766                                 {\r
 767                                         /* Only change the priority being used if the task is not\r
 768                                         currently using an inherited priority. */\r
 769                                         if( pxTCB->uxBasePriority == pxTCB->uxPriority )\r
 770                                         {\r
 771                                                 pxTCB->uxPriority = uxNewPriority;\r
 772                                         }\r
 773                                         \r
 774                                         /* The base priority gets set whatever. */\r
 775                                         pxTCB->uxBasePriority = uxNewPriority;                                  \r
 776                                 }\r
 777                                 #else\r
 778                                 {\r
 779                                         pxTCB->uxPriority = uxNewPriority;\r
 780                                 }\r
 781                                 #endif\r
 782 \r
 783                                 listSET_LIST_ITEM_VALUE( &( pxTCB->xEventListItem ), ( configMAX_PRIORITIES - ( portTickType ) uxNewPriority ) );\r
 784 \r
 785                                 /* If the task is in the blocked or suspended list we need do\r
 786                                 nothing more than change it's priority variable. However, if\r
 787                                 the task is in a ready list it needs to be removed and placed\r
 788                                 in the queue appropriate to its new priority. */\r
 789                                 if( listIS_CONTAINED_WITHIN( &( pxReadyTasksLists[ uxCurrentPriority ] ), &( pxTCB->xGenericListItem ) ) )\r
 790                                 {\r
 791                                         /* The task is currently in its ready list - remove before adding\r
 792                                         it to it's new ready list.  As we are in a critical section we\r
 793                                         can do this even if the scheduler is suspended. */\r
 794                                         vListRemove( &( pxTCB->xGenericListItem ) );\r
 795                                         prvAddTaskToReadyQueue( pxTCB );\r
 796                                 }                       \r
 797                                 \r
 798                                 if( xYieldRequired == pdTRUE )\r
 799                                 {\r
 800                                         taskYIELD();\r
 801                                 }                               \r
 802                         }\r
 803                 }\r
 804                 taskEXIT_CRITICAL();\r
 805         }\r
 806 \r
 807 #endif\r
 808 /*-----------------------------------------------------------*/\r
 809 \r
 810 #if ( INCLUDE_vTaskSuspend == 1 )\r
 811 \r
 812         void vTaskSuspend( xTaskHandle pxTaskToSuspend )\r
 813         {\r
 814         tskTCB *pxTCB;\r
 815 \r
 816                 taskENTER_CRITICAL();\r
 817                 {\r
 818                         /* Ensure a yield is performed if the current task is being\r
 819                         suspended. */\r
 820                         if( pxTaskToSuspend == pxCurrentTCB )\r
 821                         {\r
 822                                 pxTaskToSuspend = NULL;\r
 823                         }\r
 824 \r
 825                         /* If null is passed in here then we are suspending ourselves. */\r
 826                         pxTCB = prvGetTCBFromHandle( pxTaskToSuspend );\r
 827 \r
 828                         traceTASK_SUSPEND( pxTaskToSuspend );\r
 829 \r
 830                         /* Remove task from the ready/delayed list and place in the     suspended list. */\r
 831                         vListRemove( &( pxTCB->xGenericListItem ) );\r
 832 \r
 833                         /* Is the task waiting on an event also? */                                                                                             \r
 834                         if( pxTCB->xEventListItem.pvContainer )\r
 835                         {\r
 836                                 vListRemove( &( pxTCB->xEventListItem ) );\r
 837                         }\r
 838 \r
 839                         vListInsertEnd( ( xList * ) &xSuspendedTaskList, &( pxTCB->xGenericListItem ) );\r
 840                 }\r
 841                 taskEXIT_CRITICAL();\r
 842 \r
 843                 /* We may have just suspended the current task. */\r
 844                 if( ( void * ) pxTaskToSuspend == NULL )\r
 845                 {\r
 846                         taskYIELD();\r
 847                 }\r
 848         }\r
 849 \r
 850 #endif\r
 851 /*-----------------------------------------------------------*/\r
 852 \r
 853 #if ( INCLUDE_vTaskSuspend == 1 )\r
 854 \r
 855         signed portBASE_TYPE xTaskIsTaskSuspended( xTaskHandle xTask )\r
 856         {\r
 857         portBASE_TYPE xReturn = pdFALSE;\r
 858         const tskTCB * const pxTCB = ( tskTCB * ) xTask;\r
 859 \r
 860                 /* Is the task we are attempting to resume actually in the\r
 861                 suspended list? */\r
 862                 if( listIS_CONTAINED_WITHIN( &xSuspendedTaskList, &( pxTCB->xGenericListItem ) ) != pdFALSE )\r
 863                 {\r
 864                         /* Has the task already been resumed from within an ISR? */\r
 865                         if( listIS_CONTAINED_WITHIN( &xPendingReadyList, &( pxTCB->xEventListItem ) ) != pdTRUE )\r
 866                         {                       \r
 867                                 /* Is it in the suspended list because it is in the\r
 868                                 Suspended state?  It is possible to be in the suspended\r
 869                                 list because it is blocked on a task with no timeout\r
 870                                 specified. */\r
 871                                 if( listIS_CONTAINED_WITHIN( NULL, &( pxTCB->xEventListItem ) ) == pdTRUE )\r
 872                                 {\r
 873                                         xReturn = pdTRUE;\r
 874                                 }\r
 875                         }\r
 876                 }\r
 877 \r
 878                 return xReturn;\r
 879         }\r
 880 \r
 881 #endif\r
 882 /*-----------------------------------------------------------*/\r
 883 \r
 884 #if ( INCLUDE_vTaskSuspend == 1 )\r
 885 \r
 886         void vTaskResume( xTaskHandle pxTaskToResume )\r
 887         {\r
 888         tskTCB *pxTCB;\r
 889 \r
 890                 /* Remove the task from whichever list it is currently in, and place\r
 891                 it in the ready list. */\r
 892                 pxTCB = ( tskTCB * ) pxTaskToResume;\r
 893 \r
 894                 /* The parameter cannot be NULL as it is impossible to resume the\r
 895                 currently executing task. */\r
 896                 if( ( pxTCB != NULL ) && ( pxTCB != pxCurrentTCB ) )\r
 897                 {\r
 898                         taskENTER_CRITICAL();\r
 899                         {\r
 900                                 if( xTaskIsTaskSuspended( pxTCB ) == pdTRUE )\r
 901                                 {\r
 902                                         traceTASK_RESUME( pxTCB );\r
 903 \r
 904                                         /* As we are in a critical section we can access the ready\r
 905                                         lists even if the scheduler is suspended. */\r
 906                                         vListRemove(  &( pxTCB->xGenericListItem ) );\r
 907                                         prvAddTaskToReadyQueue( pxTCB );\r
 908 \r
 909                                         /* We may have just resumed a higher priority task. */\r
 910                                         if( pxTCB->uxPriority >= pxCurrentTCB->uxPriority )\r
 911                                         {\r
 912                                                 /* This yield may not cause the task just resumed to run, but\r
 913                                                 will leave the lists in the correct state for the next yield. */\r
 914                                                 taskYIELD();\r
 915                                         }\r
 916                                 }\r
 917                         }\r
 918                         taskEXIT_CRITICAL();\r
 919                 }\r
 920         }\r
 921 \r
 922 #endif\r
 923 \r
 924 /*-----------------------------------------------------------*/\r
 925 \r
 926 #if ( ( INCLUDE_xTaskResumeFromISR == 1 ) && ( INCLUDE_vTaskSuspend == 1 ) )\r
 927 \r
 928         portBASE_TYPE xTaskResumeFromISR( xTaskHandle pxTaskToResume )\r
 929         {\r
 930         portBASE_TYPE xYieldRequired = pdFALSE;\r
 931         tskTCB *pxTCB;\r
 932 \r
 933                 pxTCB = ( tskTCB * ) pxTaskToResume;\r
 934 \r
 935                 if( xTaskIsTaskSuspended( pxTCB ) == pdTRUE )\r
 936                 {\r
 937                         traceTASK_RESUME_FROM_ISR( pxTCB );\r
 938 \r
 939                         if( uxSchedulerSuspended == ( unsigned portBASE_TYPE ) pdFALSE )\r
 940                         {\r
 941                                 xYieldRequired = ( pxTCB->uxPriority >= pxCurrentTCB->uxPriority );\r
 942                                 vListRemove(  &( pxTCB->xGenericListItem ) );   \r
 943                                 prvAddTaskToReadyQueue( pxTCB );\r
 944                         }\r
 945                         else\r
 946                         {\r
 947                                 /* We cannot access the delayed or ready lists, so will hold this\r
 948                                 task pending until the scheduler is resumed, at which point a\r
 949                                 yield will be performed if necessary. */\r
 950                                 vListInsertEnd( ( xList * ) &( xPendingReadyList ), &( pxTCB->xEventListItem ) );\r
 951                         }\r
 952                 }\r
 953 \r
 954                 return xYieldRequired;\r
 955         }\r
 956 \r
 957 #endif\r
 958 \r
 959 \r
 960 \r
 961 \r
 962 /*-----------------------------------------------------------\r
 963  * PUBLIC SCHEDULER CONTROL documented in task.h\r
 964  *----------------------------------------------------------*/\r
 965 \r
 966 \r
 967 void vTaskStartScheduler( void )\r
 968 {\r
 969 portBASE_TYPE xReturn;\r
 970 \r
 971         /* Add the idle task at the lowest priority. */\r
 972         xReturn = xTaskCreate( prvIdleTask, ( signed portCHAR * ) "IDLE", tskIDLE_STACK_SIZE, ( void * ) NULL, tskIDLE_PRIORITY, ( xTaskHandle * ) NULL );\r
 973 \r
 974         if( xReturn == pdPASS )\r
 975         {\r
 976                 /* Interrupts are turned off here, to ensure a tick does not occur\r
 977                 before or during the call to xPortStartScheduler().  The stacks of\r
 978                 the created tasks contain a status word with interrupts switched on\r
 979                 so interrupts will automatically get re-enabled when the first task\r
 980                 starts to run.\r
 981                 \r
 982                 STEPPING THROUGH HERE USING A DEBUGGER CAN CAUSE BIG PROBLEMS IF THE\r
 983                 DEBUGGER ALLOWS INTERRUPTS TO BE PROCESSED. */\r
 984                 portDISABLE_INTERRUPTS();\r
 985 \r
 986                 xSchedulerRunning = pdTRUE;\r
 987                 xTickCount = ( portTickType ) 0;\r
 988 \r
 989                 /* Setting up the timer tick is hardware specific and thus in the\r
 990                 portable interface. */\r
 991                 if( xPortStartScheduler() )\r
 992                 {\r
 993                         /* Should not reach here as if the scheduler is running the\r
 994                         function will not return. */\r
 995                 }\r
 996                 else\r
 997                 {\r
 998                         /* Should only reach here if a task calls xTaskEndScheduler(). */\r
 999                 }\r
1000         }\r
1001 }\r
1002 /*-----------------------------------------------------------*/\r
1003 \r
1004 void vTaskEndScheduler( void )\r
1005 {\r
1006         /* Stop the scheduler interrupts and call the portable scheduler end\r
1007         routine so the original ISRs can be restored if necessary.  The port\r
1008         layer must ensure interrupts enable     bit is left in the correct state. */\r
1009         portDISABLE_INTERRUPTS();\r
1010         xSchedulerRunning = pdFALSE;\r
1011         vPortEndScheduler();\r
1012 }\r
1013 /*----------------------------------------------------------*/\r
1014 \r
1015 void vTaskSuspendAll( void )\r
1016 {\r
1017         /* A critical section is not required as the variable is of type\r
1018         portBASE_TYPE. */\r
1019         ++uxSchedulerSuspended;\r
1020 }\r
1021 /*----------------------------------------------------------*/\r
1022 \r
1023 signed portBASE_TYPE xTaskResumeAll( void )\r
1024 {\r
1025 register tskTCB *pxTCB;\r
1026 signed portBASE_TYPE xAlreadyYielded = pdFALSE;\r
1027 \r
1028         /* It is possible that an ISR caused a task to be removed from an event\r
1029         list while the scheduler was suspended.  If this was the case then the\r
1030         removed task will have been added to the xPendingReadyList.  Once the\r
1031         scheduler has been resumed it is safe to move all the pending ready\r
1032         tasks from this list into their appropriate ready list. */\r
1033         portENTER_CRITICAL();\r
1034         {\r
1035                 --uxSchedulerSuspended;\r
1036 \r
1037                 if( uxSchedulerSuspended == ( unsigned portBASE_TYPE ) pdFALSE )\r
1038                 {                       \r
1039                         if( uxCurrentNumberOfTasks > ( unsigned portBASE_TYPE ) 0 )\r
1040                         {\r
1041                                 portBASE_TYPE xYieldRequired = pdFALSE;\r
1042                                 \r
1043                                 /* Move any readied tasks from the pending list into the\r
1044                                 appropriate ready list. */\r
1045                                 while( ( pxTCB = ( tskTCB * ) listGET_OWNER_OF_HEAD_ENTRY(  ( ( xList * ) &xPendingReadyList ) ) ) != NULL )\r
1046                                 {\r
1047                                         vListRemove( &( pxTCB->xEventListItem ) );\r
1048                                         vListRemove( &( pxTCB->xGenericListItem ) );\r
1049                                         prvAddTaskToReadyQueue( pxTCB );\r
1050                                         \r
1051                                         /* If we have moved a task that has a priority higher than\r
1052                                         the current task then we should yield. */\r
1053                                         if( pxTCB->uxPriority >= pxCurrentTCB->uxPriority )\r
1054                                         {\r
1055                                                 xYieldRequired = pdTRUE;\r
1056                                         }\r
1057                                 }\r
1058 \r
1059                                 /* If any ticks occurred while the scheduler was suspended then\r
1060                                 they should be processed now.  This ensures the tick count does not\r
1061                                 slip, and that any delayed tasks are resumed at the correct time. */\r
1062                                 if( uxMissedTicks > ( unsigned portBASE_TYPE ) 0 )\r
1063                                 {\r
1064                                         while( uxMissedTicks > ( unsigned portBASE_TYPE ) 0 )\r
1065                                         {\r
1066                                                 vTaskIncrementTick();\r
1067                                                 --uxMissedTicks;\r
1068                                         }\r
1069 \r
1070                                         /* As we have processed some ticks it is appropriate to yield\r
1071                                         to ensure the highest priority task that is ready to run is\r
1072                                         the task actually running. */\r
1073                                         #if configUSE_PREEMPTION == 1\r
1074                                         {\r
1075                                                 xYieldRequired = pdTRUE;\r
1076                                         }\r
1077                                         #endif\r
1078                                 }\r
1079                                 \r
1080                                 if( ( xYieldRequired == pdTRUE ) || ( xMissedYield == pdTRUE ) )\r
1081                                 {\r
1082                                         xAlreadyYielded = pdTRUE;\r
1083                                         xMissedYield = pdFALSE;\r
1084                                         taskYIELD();\r
1085                                 }\r
1086                         }\r
1087                 }\r
1088         }\r
1089         portEXIT_CRITICAL();\r
1090 \r
1091         return xAlreadyYielded;\r
1092 }\r
1093 \r
1094 \r
1095 \r
1096 \r
1097 \r
1098 \r
1099 /*-----------------------------------------------------------\r
1100  * PUBLIC TASK UTILITIES documented in task.h\r
1101  *----------------------------------------------------------*/\r
1102 \r
1103 \r
1104 \r
1105 portTickType xTaskGetTickCount( void )\r
1106 {\r
1107 portTickType xTicks;\r
1108 \r
1109         /* Critical section required if running on a 16 bit processor. */\r
1110         taskENTER_CRITICAL();\r
1111         {\r
1112                 xTicks = xTickCount;\r
1113         }\r
1114         taskEXIT_CRITICAL();\r
1115 \r
1116         return xTicks;\r
1117 }\r
1118 /*-----------------------------------------------------------*/\r
1119 \r
1120 unsigned portBASE_TYPE uxTaskGetNumberOfTasks( void )\r
1121 {\r
1122         /* A critical section is not required because the variables are of type\r
1123         portBASE_TYPE. */\r
1124         return uxCurrentNumberOfTasks;\r
1125 }\r
1126 /*-----------------------------------------------------------*/\r
1127 \r
1128 #if ( ( configUSE_TRACE_FACILITY == 1 ) && ( INCLUDE_vTaskDelete == 1 ) && ( INCLUDE_vTaskSuspend == 1 ) )\r
1129 \r
1130         void vTaskList( signed portCHAR *pcWriteBuffer )\r
1131         {\r
1132         unsigned portBASE_TYPE uxQueue;\r
1133 \r
1134                 /* This is a VERY costly function that should be used for debug only.\r
1135                 It leaves interrupts disabled for a LONG time. */\r
1136 \r
1137         vTaskSuspendAll();\r
1138                 {\r
1139                         /* Run through all the lists that could potentially contain a TCB and\r
1140                         report the task name, state and stack high water mark. */\r
1141 \r
1142                         pcWriteBuffer[ 0 ] = ( signed portCHAR ) 0x00;\r
1143                         strcat( ( portCHAR * ) pcWriteBuffer, ( const portCHAR * ) "\r\n" );\r
1144 \r
1145                         uxQueue = uxTopUsedPriority + 1;\r
1146 \r
1147                         do\r
1148                         {\r
1149                                 uxQueue--;\r
1150 \r
1151                                 if( !listLIST_IS_EMPTY( &( pxReadyTasksLists[ uxQueue ] ) ) )\r
1152                                 {\r
1153                                         prvListTaskWithinSingleList( pcWriteBuffer, ( xList * ) &( pxReadyTasksLists[ uxQueue ] ), tskREADY_CHAR );                     \r
1154                                 }\r
1155                         }while( uxQueue > ( unsigned portSHORT ) tskIDLE_PRIORITY );\r
1156 \r
1157                         if( !listLIST_IS_EMPTY( pxDelayedTaskList ) )\r
1158                         {\r
1159                                 prvListTaskWithinSingleList( pcWriteBuffer, ( xList * ) pxDelayedTaskList, tskBLOCKED_CHAR );\r
1160                         }\r
1161 \r
1162                         if( !listLIST_IS_EMPTY( pxOverflowDelayedTaskList ) )\r
1163                         {\r
1164                                 prvListTaskWithinSingleList( pcWriteBuffer, ( xList * ) pxOverflowDelayedTaskList, tskBLOCKED_CHAR );\r
1165                         }\r
1166 \r
1167                         if( !listLIST_IS_EMPTY( &xTasksWaitingTermination ) )\r
1168                         {\r
1169                                 prvListTaskWithinSingleList( pcWriteBuffer, ( xList * ) &xTasksWaitingTermination, tskDELETED_CHAR );\r
1170                         }\r
1171 \r
1172                         if( !listLIST_IS_EMPTY( &xSuspendedTaskList ) )\r
1173                         {\r
1174                                 prvListTaskWithinSingleList( pcWriteBuffer, ( xList * ) &xSuspendedTaskList, tskSUSPENDED_CHAR );\r
1175                         }\r
1176                 }\r
1177         xTaskResumeAll();\r
1178         }\r
1179 \r
1180 #endif\r
1181 /*----------------------------------------------------------*/\r
1182 \r
1183 #if ( configUSE_TRACE_FACILITY == 1 )\r
1184 \r
1185         void vTaskStartTrace( signed portCHAR * pcBuffer, unsigned portLONG ulBufferSize )\r
1186         {\r
1187                 portENTER_CRITICAL();\r
1188                 {\r
1189                         pcTraceBuffer = ( signed portCHAR * )pcBuffer;\r
1190                         pcTraceBufferStart = pcBuffer;\r
1191                         pcTraceBufferEnd = pcBuffer + ( ulBufferSize - tskSIZE_OF_EACH_TRACE_LINE );\r
1192                         xTracing = pdTRUE;\r
1193                 }\r
1194                 portEXIT_CRITICAL();\r
1195         }\r
1196 \r
1197 #endif\r
1198 /*----------------------------------------------------------*/\r
1199 \r
1200 #if ( configUSE_TRACE_FACILITY == 1 )\r
1201 \r
1202         unsigned portLONG ulTaskEndTrace( void )\r
1203         {\r
1204         unsigned portLONG ulBufferLength;\r
1205 \r
1206                 portENTER_CRITICAL();\r
1207                         xTracing = pdFALSE;\r
1208                 portEXIT_CRITICAL();\r
1209 \r
1210                 ulBufferLength = ( unsigned portLONG ) ( pcTraceBuffer - pcTraceBufferStart );\r
1211 \r
1212                 return ulBufferLength;\r
1213         }\r
1214 \r
1215 #endif\r
1216 \r
1217 \r
1218 \r
1219 /*-----------------------------------------------------------\r
1220  * SCHEDULER INTERNALS AVAILABLE FOR PORTING PURPOSES\r
1221  * documented in task.h\r
1222  *----------------------------------------------------------*/\r
1223 \r
1224 \r
1225 void vTaskIncrementTick( void )\r
1226 {\r
1227         /* Called by the portable layer each time a tick interrupt occurs.\r
1228         Increments the tick then checks to see if the new tick value will cause any\r
1229         tasks to be unblocked. */\r
1230         if( uxSchedulerSuspended == ( unsigned portBASE_TYPE ) pdFALSE )\r
1231         {\r
1232                 ++xTickCount;\r
1233                 if( xTickCount == ( portTickType ) 0 )\r
1234                 {\r
1235                         xList *pxTemp;\r
1236 \r
1237                         /* Tick count has overflowed so we need to swap the delay lists.\r
1238                         If there are any items in pxDelayedTaskList here then there is\r
1239                         an error! */\r
1240                         pxTemp = pxDelayedTaskList;\r
1241                         pxDelayedTaskList = pxOverflowDelayedTaskList;\r
1242                         pxOverflowDelayedTaskList = pxTemp;\r
1243             xNumOfOverflows++;\r
1244                 }\r
1245 \r
1246                 /* See if this tick has made a timeout expire. */\r
1247                 prvCheckDelayedTasks();\r
1248         }\r
1249         else\r
1250         {\r
1251                 ++uxMissedTicks;\r
1252 \r
1253                 /* The tick hook gets called at regular intervals, even if the\r
1254                 scheduler is locked. */\r
1255                 #if ( configUSE_TICK_HOOK == 1 )\r
1256                 {\r
1257                         extern void vApplicationTickHook( void );\r
1258 \r
1259                         vApplicationTickHook();\r
1260                 }\r
1261                 #endif\r
1262         }\r
1263 \r
1264         #if ( configUSE_TICK_HOOK == 1 )\r
1265         {\r
1266                 extern void vApplicationTickHook( void );\r
1267 \r
1268                 /* Guard against the tick hook being called when the missed tick\r
1269                 count is being unwound (when the scheduler is being unlocked. */\r
1270                 if( uxMissedTicks == 0 )\r
1271                 {\r
1272                         vApplicationTickHook();\r
1273                 }\r
1274         }\r
1275         #endif\r
1276 \r
1277         traceTASK_INCREMENT_TICK( xTickCount );\r
1278 }\r
1279 /*-----------------------------------------------------------*/\r
1280 \r
1281 #if ( ( INCLUDE_vTaskCleanUpResources == 1 ) && ( INCLUDE_vTaskSuspend == 1 ) )\r
1282 \r
1283         void vTaskCleanUpResources( void )\r
1284         {\r
1285         unsigned portSHORT usQueue;\r
1286         volatile tskTCB *pxTCB;\r
1287 \r
1288                 usQueue = ( unsigned portSHORT ) uxTopUsedPriority + ( unsigned portSHORT ) 1;\r
1289 \r
1290                 /* Remove any TCB's from the ready queues. */\r
1291                 do\r
1292                 {\r
1293                         usQueue--;\r
1294 \r
1295                         while( !listLIST_IS_EMPTY( &( pxReadyTasksLists[ usQueue ] ) ) )\r
1296                         {\r
1297                                 listGET_OWNER_OF_NEXT_ENTRY( pxTCB, &( pxReadyTasksLists[ usQueue ] ) );\r
1298                                 vListRemove( ( xListItem * ) &( pxTCB->xGenericListItem ) );\r
1299 \r
1300                                 prvDeleteTCB( ( tskTCB * ) pxTCB );\r
1301                         }\r
1302                 }while( usQueue > ( unsigned portSHORT ) tskIDLE_PRIORITY );\r
1303 \r
1304                 /* Remove any TCB's from the delayed queue. */\r
1305                 while( !listLIST_IS_EMPTY( &xDelayedTaskList1 ) )\r
1306                 {\r
1307                         listGET_OWNER_OF_NEXT_ENTRY( pxTCB, &xDelayedTaskList1 );\r
1308                         vListRemove( ( xListItem * ) &( pxTCB->xGenericListItem ) );\r
1309 \r
1310                         prvDeleteTCB( ( tskTCB * ) pxTCB );\r
1311                 }\r
1312 \r
1313                 /* Remove any TCB's from the overflow delayed queue. */\r
1314                 while( !listLIST_IS_EMPTY( &xDelayedTaskList2 ) )\r
1315                 {\r
1316                         listGET_OWNER_OF_NEXT_ENTRY( pxTCB, &xDelayedTaskList2 );\r
1317                         vListRemove( ( xListItem * ) &( pxTCB->xGenericListItem ) );\r
1318 \r
1319                         prvDeleteTCB( ( tskTCB * ) pxTCB );\r
1320                 }\r
1321 \r
1322                 while( !listLIST_IS_EMPTY( &xSuspendedTaskList ) )\r
1323                 {\r
1324                         listGET_OWNER_OF_NEXT_ENTRY( pxTCB, &xSuspendedTaskList );\r
1325                         vListRemove( ( xListItem * ) &( pxTCB->xGenericListItem ) );\r
1326 \r
1327                         prvDeleteTCB( ( tskTCB * ) pxTCB );\r
1328                 }               \r
1329         }\r
1330 \r
1331 #endif\r
1332 /*-----------------------------------------------------------*/\r
1333 \r
1334 #if ( configUSE_APPLICATION_TASK_TAG == 1 )\r
1335 \r
1336         void vTaskSetApplicationTaskTag( xTaskHandle xTask, pdTASK_HOOK_CODE pxTagValue )\r
1337         {\r
1338         tskTCB *xTCB;\r
1339 \r
1340                 /* If xTask is NULL then we are setting our own task hook. */\r
1341                 if( xTask == NULL )\r
1342                 {\r
1343                         xTCB = ( tskTCB * ) pxCurrentTCB;\r
1344                 }\r
1345                 else\r
1346                 {\r
1347                         xTCB = ( tskTCB * ) xTask;\r
1348                 }\r
1349                 \r
1350                 /* Save the hook function in the TCB.  A critical section is required as\r
1351                 the value can be accessed from an interrupt. */\r
1352                 portENTER_CRITICAL();\r
1353                         xTCB->pxTaskTag = pxTagValue;\r
1354                 portEXIT_CRITICAL();\r
1355         }\r
1356         \r
1357 #endif\r
1358 /*-----------------------------------------------------------*/\r
1359 \r
1360 #if ( configUSE_APPLICATION_TASK_TAG == 1 )\r
1361 \r
1362         portBASE_TYPE xTaskCallApplicationTaskHook( xTaskHandle xTask, void *pvParameter )\r
1363         {\r
1364         tskTCB *xTCB;\r
1365         portBASE_TYPE xReturn;\r
1366 \r
1367                 /* If xTask is NULL then we are calling our own task hook. */\r
1368                 if( xTask == NULL )\r
1369                 {\r
1370                         xTCB = ( tskTCB * ) pxCurrentTCB;\r
1371                 }\r
1372                 else\r
1373                 {\r
1374                         xTCB = ( tskTCB * ) xTask;\r
1375                 }\r
1376 \r
1377                 if( xTCB->pxTaskTag != NULL )\r
1378                 {\r
1379                         xReturn = xTCB->pxTaskTag( pvParameter );\r
1380                 }\r
1381                 else\r
1382                 {\r
1383                         xReturn = pdFAIL;\r
1384                 }\r
1385 \r
1386                 return xReturn;\r
1387         }\r
1388         \r
1389 #endif\r
1390 /*-----------------------------------------------------------*/\r
1391 \r
1392 void vTaskSwitchContext( void )\r
1393 {\r
1394         traceTASK_SWITCHED_OUT();\r
1395 \r
1396         if( uxSchedulerSuspended != ( unsigned portBASE_TYPE ) pdFALSE )\r
1397         {\r
1398                 /* The scheduler is currently suspended - do not allow a context\r
1399                 switch. */\r
1400                 xMissedYield = pdTRUE;\r
1401                 return;\r
1402         }\r
1403 \r
1404         taskFIRST_CHECK_FOR_STACK_OVERFLOW();\r
1405         taskSECOND_CHECK_FOR_STACK_OVERFLOW();\r
1406 \r
1407         /* Find the highest priority queue that contains ready tasks. */\r
1408         while( listLIST_IS_EMPTY( &( pxReadyTasksLists[ uxTopReadyPriority ] ) ) )\r
1409         {\r
1410                 --uxTopReadyPriority;\r
1411         }\r
1412 \r
1413         /* listGET_OWNER_OF_NEXT_ENTRY walks through the list, so the tasks of the\r
1414         same priority get an equal share of the processor time. */\r
1415         listGET_OWNER_OF_NEXT_ENTRY( pxCurrentTCB, &( pxReadyTasksLists[ uxTopReadyPriority ] ) );\r
1416 \r
1417         traceTASK_SWITCHED_IN();\r
1418         vWriteTraceToBuffer();\r
1419 }\r
1420 /*-----------------------------------------------------------*/\r
1421 \r
1422 void vTaskPlaceOnEventList( const xList * const pxEventList, portTickType xTicksToWait )\r
1423 {\r
1424 portTickType xTimeToWake;\r
1425 \r
1426         /* THIS FUNCTION MUST BE CALLED WITH INTERRUPTS DISABLED OR THE\r
1427         SCHEDULER SUSPENDED. */\r
1428 \r
1429         /* Place the event list item of the TCB in the appropriate event list.\r
1430         This is placed in the list in priority order so the highest priority task\r
1431         is the first to be woken by the event. */\r
1432         vListInsert( ( xList * ) pxEventList, ( xListItem * ) &( pxCurrentTCB->xEventListItem ) );\r
1433 \r
1434         /* We must remove ourselves from the ready list before adding ourselves\r
1435         to the blocked list as the same list item is used for both lists.  We have\r
1436         exclusive access to the ready lists as the scheduler is locked. */\r
1437         vListRemove( ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );\r
1438 \r
1439 \r
1440         #if ( INCLUDE_vTaskSuspend == 1 )\r
1441         {                       \r
1442                 if( xTicksToWait == portMAX_DELAY )\r
1443                 {\r
1444                         /* Add ourselves to the suspended task list instead of a delayed task\r
1445                         list to ensure we are not woken by a timing event.  We will block\r
1446                         indefinitely. */\r
1447                         vListInsertEnd( ( xList * ) &xSuspendedTaskList, ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );\r
1448                 }\r
1449                 else\r
1450                 {\r
1451                         /* Calculate the time at which the task should be woken if the event does\r
1452                         not occur.  This may overflow but this doesn't matter. */\r
1453                         xTimeToWake = xTickCount + xTicksToWait;\r
1454                 \r
1455                         listSET_LIST_ITEM_VALUE( &( pxCurrentTCB->xGenericListItem ), xTimeToWake );\r
1456                 \r
1457                         if( xTimeToWake < xTickCount )\r
1458                         {\r
1459                                 /* Wake time has overflowed.  Place this item in the overflow list. */\r
1460                                 vListInsert( ( xList * ) pxOverflowDelayedTaskList, ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );\r
1461                         }\r
1462                         else\r
1463                         {\r
1464                                 /* The wake time has not overflowed, so we can use the current block list. */\r
1465                                 vListInsert( ( xList * ) pxDelayedTaskList, ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );\r
1466                         }\r
1467                 }\r
1468         }\r
1469         #else\r
1470         {\r
1471                         /* Calculate the time at which the task should be woken if the event does\r
1472                         not occur.  This may overflow but this doesn't matter. */\r
1473                         xTimeToWake = xTickCount + xTicksToWait;\r
1474                 \r
1475                         listSET_LIST_ITEM_VALUE( &( pxCurrentTCB->xGenericListItem ), xTimeToWake );\r
1476                 \r
1477                         if( xTimeToWake < xTickCount )\r
1478                         {\r
1479                                 /* Wake time has overflowed.  Place this item in the overflow list. */\r
1480                                 vListInsert( ( xList * ) pxOverflowDelayedTaskList, ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );\r
1481                         }\r
1482                         else\r
1483                         {\r
1484                                 /* The wake time has not overflowed, so we can use the current block list. */\r
1485                                 vListInsert( ( xList * ) pxDelayedTaskList, ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );\r
1486                         }\r
1487         }\r
1488         #endif\r
1489 }\r
1490 /*-----------------------------------------------------------*/\r
1491 \r
1492 signed portBASE_TYPE xTaskRemoveFromEventList( const xList * const pxEventList )\r
1493 {\r
1494 tskTCB *pxUnblockedTCB;\r
1495 portBASE_TYPE xReturn;\r
1496 \r
1497         /* THIS FUNCTION MUST BE CALLED WITH INTERRUPTS DISABLED OR THE\r
1498         SCHEDULER SUSPENDED.  It can also be called from within an ISR. */\r
1499 \r
1500         /* The event list is sorted in priority order, so we can remove the\r
1501         first in the list, remove the TCB from the delayed list, and add\r
1502         it to the ready list.\r
1503         \r
1504         If an event is for a queue that is locked then this function will never\r
1505         get called - the lock count on the queue will get modified instead.  This\r
1506         means we can always expect exclusive access to the event list here. */\r
1507         pxUnblockedTCB = ( tskTCB * ) listGET_OWNER_OF_HEAD_ENTRY( pxEventList );\r
1508         vListRemove( &( pxUnblockedTCB->xEventListItem ) );\r
1509 \r
1510         if( uxSchedulerSuspended == ( unsigned portBASE_TYPE ) pdFALSE )\r
1511         {\r
1512                 vListRemove( &( pxUnblockedTCB->xGenericListItem ) );\r
1513                 prvAddTaskToReadyQueue( pxUnblockedTCB );\r
1514         }\r
1515         else\r
1516         {\r
1517                 /* We cannot access the delayed or ready lists, so will hold this\r
1518                 task pending until the scheduler is resumed. */\r
1519                 vListInsertEnd( ( xList * ) &( xPendingReadyList ), &( pxUnblockedTCB->xEventListItem ) );\r
1520         }\r
1521 \r
1522         if( pxUnblockedTCB->uxPriority >= pxCurrentTCB->uxPriority )\r
1523         {\r
1524                 /* Return true if the task removed from the event list has\r
1525                 a higher priority than the calling task.  This allows\r
1526                 the calling task to know if it should force a context\r
1527                 switch now. */\r
1528                 xReturn = pdTRUE;\r
1529         }\r
1530         else\r
1531         {\r
1532                 xReturn = pdFALSE;\r
1533         }\r
1534 \r
1535         return xReturn;\r
1536 }\r
1537 /*-----------------------------------------------------------*/\r
1538 \r
1539 void vTaskSetTimeOutState( xTimeOutType * const pxTimeOut )\r
1540 {\r
1541     pxTimeOut->xOverflowCount = xNumOfOverflows;\r
1542     pxTimeOut->xTimeOnEntering = xTickCount;\r
1543 }\r
1544 /*-----------------------------------------------------------*/\r
1545 \r
1546 portBASE_TYPE xTaskCheckForTimeOut( xTimeOutType * const pxTimeOut, portTickType * const pxTicksToWait )\r
1547 {\r
1548 portBASE_TYPE xReturn;\r
1549 \r
1550         portENTER_CRITICAL();\r
1551         {\r
1552                 #if ( INCLUDE_vTaskSuspend == 1 )\r
1553                         /* If INCLUDE_vTaskSuspend is set to 1 and the block time specified is\r
1554                         the maximum block time then the task should block indefinitely, and\r
1555                         therefore never time out. */\r
1556                         if( *pxTicksToWait == portMAX_DELAY )\r
1557                         {\r
1558                                 xReturn = pdFALSE;\r
1559                         }\r
1560                         else /* We are not blocking indefinitely, perform the checks below. */\r
1561                 #endif\r
1562 \r
1563                 if( ( xNumOfOverflows != pxTimeOut->xOverflowCount ) && ( xTickCount >= pxTimeOut->xTimeOnEntering ) )\r
1564                 {\r
1565                         /* The tick count is greater than the time at which vTaskSetTimeout()\r
1566                         was called, but has also overflowed since vTaskSetTimeOut() was called.\r
1567                         It must have wrapped all the way around and gone past us again. This\r
1568                         passed since vTaskSetTimeout() was called. */\r
1569                         xReturn = pdTRUE;\r
1570                 }\r
1571                 else if( ( xTickCount - pxTimeOut->xTimeOnEntering ) < *pxTicksToWait )\r
1572                 {\r
1573                         /* Not a genuine timeout. Adjust parameters for time remaining. */\r
1574                         *pxTicksToWait -= ( xTickCount - pxTimeOut->xTimeOnEntering );\r
1575                         vTaskSetTimeOutState( pxTimeOut );\r
1576                         xReturn = pdFALSE;\r
1577                 }\r
1578                 else\r
1579                 {\r
1580                         xReturn = pdTRUE;\r
1581                 }\r
1582         }\r
1583         portEXIT_CRITICAL();\r
1584 \r
1585     return xReturn;\r
1586 }\r
1587 /*-----------------------------------------------------------*/\r
1588 \r
1589 void vTaskMissedYield( void )\r
1590 {\r
1591         xMissedYield = pdTRUE;\r
1592 }\r
1593 \r
1594 /*\r
1595  * -----------------------------------------------------------\r
1596  * The Idle task.\r
1597  * ----------------------------------------------------------\r
1598  *\r
1599  * The portTASK_FUNCTION() macro is used to allow port/compiler specific\r
1600  * language extensions.  The equivalent prototype for this function is:\r
1601  *\r
1602  * void prvIdleTask( void *pvParameters );\r
1603  *\r
1604  */\r
1605 static portTASK_FUNCTION( prvIdleTask, pvParameters )\r
1606 {\r
1607         /* Stop warnings. */\r
1608         ( void ) pvParameters;\r
1609 \r
1610         for( ;; )\r
1611         {\r
1612                 /* See if any tasks have been deleted. */\r
1613                 prvCheckTasksWaitingTermination();\r
1614 \r
1615                 #if ( configUSE_PREEMPTION == 0 )\r
1616                 {\r
1617                         /* If we are not using preemption we keep forcing a task switch to\r
1618                         see if any other task has become available.  If we are using\r
1619                         preemption we don't need to do this as any task becoming available\r
1620                         will automatically get the processor anyway. */\r
1621                         taskYIELD();    \r
1622                 }\r
1623                 #endif\r
1624 \r
1625                 #if ( ( configUSE_PREEMPTION == 1 ) && ( configIDLE_SHOULD_YIELD == 1 ) )\r
1626                 {\r
1627                         /* When using preemption tasks of equal priority will be\r
1628                         timesliced.  If a task that is sharing the idle priority is ready\r
1629                         to run then the idle task should yield before the end of the\r
1630                         timeslice.\r
1631                         \r
1632                         A critical region is not required here as we are just reading from\r
1633                         the list, and an occasional incorrect value will not matter.  If\r
1634                         the ready list at the idle priority contains more than one task\r
1635                         then a task other than the idle task is ready to execute. */\r
1636                         if( listCURRENT_LIST_LENGTH( &( pxReadyTasksLists[ tskIDLE_PRIORITY ] ) ) > ( unsigned portBASE_TYPE ) 1 )\r
1637                         {\r
1638                                 taskYIELD();\r
1639                         }\r
1640                 }\r
1641                 #endif\r
1642 \r
1643                 #if ( configUSE_IDLE_HOOK == 1 )\r
1644                 {\r
1645                         extern void vApplicationIdleHook( void );\r
1646 \r
1647                         /* Call the user defined function from within the idle task.  This\r
1648                         allows the application designer to add background functionality\r
1649                         without the overhead of a separate task.\r
1650                         NOTE: vApplicationIdleHook() MUST NOT, UNDER ANY CIRCUMSTANCES,\r
1651                         CALL A FUNCTION THAT MIGHT BLOCK. */\r
1652                         vApplicationIdleHook();\r
1653                 }\r
1654                 #endif\r
1655         }\r
1656 } /*lint !e715 pvParameters is not accessed but all task functions require the same prototype. */\r
1657 \r
1658 \r
1659 \r
1660 \r
1661 \r
1662 \r
1663 \r
1664 /*-----------------------------------------------------------\r
1665  * File private functions documented at the top of the file.\r
1666  *----------------------------------------------------------*/\r
1667 \r
1668 \r
1669 \r
1670 static void prvInitialiseTCBVariables( tskTCB *pxTCB, const signed portCHAR * const pcName, unsigned portBASE_TYPE uxPriority )\r
1671 {\r
1672         /* Store the function name in the TCB. */\r
1673         strncpy( ( char * ) pxTCB->pcTaskName, ( const char * ) pcName, ( unsigned portSHORT ) configMAX_TASK_NAME_LEN );\r
1674         pxTCB->pcTaskName[ ( unsigned portSHORT ) configMAX_TASK_NAME_LEN - ( unsigned portSHORT ) 1 ] = '\0';\r
1675 \r
1676         /* This is used as an array index so must ensure it's not too large. */\r
1677         if( uxPriority >= configMAX_PRIORITIES )\r
1678         {\r
1679                 uxPriority = configMAX_PRIORITIES - 1;\r
1680         }\r
1681 \r
1682         pxTCB->uxPriority = uxPriority;\r
1683         #if ( configUSE_MUTEXES == 1 )\r
1684         {\r
1685                 pxTCB->uxBasePriority = uxPriority;\r
1686         }\r
1687         #endif\r
1688 \r
1689         vListInitialiseItem( &( pxTCB->xGenericListItem ) );\r
1690         vListInitialiseItem( &( pxTCB->xEventListItem ) );\r
1691 \r
1692         /* Set the pxTCB as a link back from the xListItem.  This is so we can get\r
1693         back to the containing TCB from a generic item in a list. */\r
1694         listSET_LIST_ITEM_OWNER( &( pxTCB->xGenericListItem ), pxTCB );\r
1695 \r
1696         /* Event lists are always in priority order. */\r
1697         listSET_LIST_ITEM_VALUE( &( pxTCB->xEventListItem ), configMAX_PRIORITIES - ( portTickType ) uxPriority );\r
1698         listSET_LIST_ITEM_OWNER( &( pxTCB->xEventListItem ), pxTCB );\r
1699 \r
1700         #if ( portCRITICAL_NESTING_IN_TCB == 1 )\r
1701         {\r
1702                 pxTCB->uxCriticalNesting = ( unsigned portBASE_TYPE ) 0;\r
1703         }\r
1704         #endif\r
1705 \r
1706         #if ( configUSE_APPLICATION_TASK_TAG == 1 )\r
1707         {\r
1708                 pxTCB->pxTaskTag = NULL;\r
1709         }\r
1710         #endif  \r
1711 }\r
1712 /*-----------------------------------------------------------*/\r
1713 \r
1714 static void prvInitialiseTaskLists( void )\r
1715 {\r
1716 unsigned portBASE_TYPE uxPriority;\r
1717 \r
1718         for( uxPriority = 0; uxPriority < configMAX_PRIORITIES; uxPriority++ )\r
1719         {\r
1720                 vListInitialise( ( xList * ) &( pxReadyTasksLists[ uxPriority ] ) );\r
1721         }\r
1722 \r
1723         vListInitialise( ( xList * ) &xDelayedTaskList1 );\r
1724         vListInitialise( ( xList * ) &xDelayedTaskList2 );\r
1725         vListInitialise( ( xList * ) &xPendingReadyList );\r
1726 \r
1727         #if ( INCLUDE_vTaskDelete == 1 )\r
1728         {\r
1729                 vListInitialise( ( xList * ) &xTasksWaitingTermination );\r
1730         }\r
1731         #endif\r
1732 \r
1733         #if ( INCLUDE_vTaskSuspend == 1 )\r
1734         {\r
1735                 vListInitialise( ( xList * ) &xSuspendedTaskList );\r
1736         }\r
1737         #endif\r
1738 \r
1739         /* Start with pxDelayedTaskList using list1 and the pxOverflowDelayedTaskList\r
1740         using list2. */\r
1741         pxDelayedTaskList = &xDelayedTaskList1;\r
1742         pxOverflowDelayedTaskList = &xDelayedTaskList2;\r
1743 }\r
1744 /*-----------------------------------------------------------*/\r
1745 \r
1746 static void prvCheckTasksWaitingTermination( void )\r
1747 {                                                       \r
1748         #if ( INCLUDE_vTaskDelete == 1 )\r
1749         {                               \r
1750                 portBASE_TYPE xListIsEmpty;\r
1751 \r
1752                 /* ucTasksDeleted is used to prevent vTaskSuspendAll() being called\r
1753                 too often in the idle task. */\r
1754                 if( uxTasksDeleted > ( unsigned portBASE_TYPE ) 0 )\r
1755                 {\r
1756                         vTaskSuspendAll();\r
1757                                 xListIsEmpty = listLIST_IS_EMPTY( &xTasksWaitingTermination );                          \r
1758                         xTaskResumeAll();\r
1759 \r
1760                         if( !xListIsEmpty )\r
1761                         {\r
1762                                 tskTCB *pxTCB;\r
1763 \r
1764                                 portENTER_CRITICAL();\r
1765                                 {                       \r
1766                                         pxTCB = ( tskTCB * ) listGET_OWNER_OF_HEAD_ENTRY( ( ( xList * ) &xTasksWaitingTermination ) );\r
1767                                         vListRemove( &( pxTCB->xGenericListItem ) );\r
1768                                         --uxCurrentNumberOfTasks;\r
1769                                         --uxTasksDeleted;\r
1770                                 }\r
1771                                 portEXIT_CRITICAL();\r
1772 \r
1773                                 prvDeleteTCB( pxTCB );\r
1774                         }\r
1775                 }\r
1776         }\r
1777         #endif\r
1778 }\r
1779 /*-----------------------------------------------------------*/\r
1780 \r
1781 static tskTCB *prvAllocateTCBAndStack( unsigned portSHORT usStackDepth )\r
1782 {\r
1783 tskTCB *pxNewTCB;\r
1784 \r
1785         /* Allocate space for the TCB.  Where the memory comes from depends on\r
1786         the implementation of the port malloc function. */\r
1787         pxNewTCB = ( tskTCB * ) pvPortMalloc( sizeof( tskTCB ) );\r
1788 \r
1789         if( pxNewTCB != NULL )\r
1790         {\r
1791                 /* Allocate space for the stack used by the task being created.\r
1792                 The base of the stack memory stored in the TCB so the task can\r
1793                 be deleted later if required. */\r
1794                 pxNewTCB->pxStack = ( portSTACK_TYPE * ) pvPortMalloc( ( ( size_t )usStackDepth ) * sizeof( portSTACK_TYPE ) );\r
1795 \r
1796                 if( pxNewTCB->pxStack == NULL )\r
1797                 {\r
1798                         /* Could not allocate the stack.  Delete the allocated TCB. */\r
1799                         vPortFree( pxNewTCB );                  \r
1800                         pxNewTCB = NULL;                        \r
1801                 }               \r
1802                 else\r
1803                 {\r
1804                         /* Just to help debugging. */\r
1805                         memset( pxNewTCB->pxStack, tskSTACK_FILL_BYTE, usStackDepth * sizeof( portSTACK_TYPE ) );\r
1806                 }\r
1807         }\r
1808 \r
1809         return pxNewTCB;\r
1810 }\r
1811 /*-----------------------------------------------------------*/\r
1812 \r
1813 #if ( configUSE_TRACE_FACILITY == 1 )\r
1814 \r
1815         static void prvListTaskWithinSingleList( const signed portCHAR *pcWriteBuffer, xList *pxList, signed portCHAR cStatus )\r
1816         {\r
1817         volatile tskTCB *pxNextTCB, *pxFirstTCB;\r
1818         unsigned portSHORT usStackRemaining;\r
1819 \r
1820                 /* Write the details of all the TCB's in pxList into the buffer. */\r
1821                 listGET_OWNER_OF_NEXT_ENTRY( pxFirstTCB, pxList );\r
1822                 do\r
1823                 {\r
1824                         listGET_OWNER_OF_NEXT_ENTRY( pxNextTCB, pxList );\r
1825                         usStackRemaining = usTaskCheckFreeStackSpace( ( unsigned portCHAR * ) pxNextTCB->pxStack );\r
1826                         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
1827                         strcat( ( portCHAR * ) pcWriteBuffer, ( portCHAR * ) pcStatusString );\r
1828 \r
1829                 } while( pxNextTCB != pxFirstTCB );\r
1830         }\r
1831 \r
1832 #endif\r
1833 /*-----------------------------------------------------------*/\r
1834 \r
1835 #if ( ( configUSE_TRACE_FACILITY == 1 ) || ( INCLUDE_uxTaskGetStackHighWaterMark == 1 ) )\r
1836 \r
1837         unsigned portSHORT usTaskCheckFreeStackSpace( const unsigned portCHAR * pucStackByte )\r
1838         {\r
1839         register unsigned portSHORT usCount = 0;\r
1840 \r
1841                 while( *pucStackByte == tskSTACK_FILL_BYTE )\r
1842                 {\r
1843                         pucStackByte -= portSTACK_GROWTH;\r
1844                         usCount++;\r
1845                 }\r
1846 \r
1847                 usCount /= sizeof( portSTACK_TYPE );\r
1848 \r
1849                 return usCount;\r
1850         }\r
1851 \r
1852 #endif\r
1853 /*-----------------------------------------------------------*/\r
1854 \r
1855 #if ( INCLUDE_uxTaskGetStackHighWaterMark == 1 )\r
1856 \r
1857         unsigned portBASE_TYPE uxTaskGetStackHighWaterMark( xTaskHandle xTask )\r
1858         {\r
1859         tskTCB *pxTCB;\r
1860         unsigned portCHAR *pcEndOfStack;\r
1861 \r
1862                 pxTCB = prvGetTCBFromHandle( xTask );\r
1863 \r
1864                 #if portSTACK_GROWTH < 0\r
1865                 {\r
1866                         pcEndOfStack = ( unsigned portCHAR * ) pxTCB->pxStack;\r
1867                 }\r
1868                 #else\r
1869                 {\r
1870                         pcEndOfStack = ( unsigned portCHAR * ) pxTCB->pxEndOfStack;\r
1871                 }\r
1872                 #endif\r
1873 \r
1874                 return usTaskCheckFreeStackSpace( pcEndOfStack );\r
1875         }\r
1876 \r
1877 #endif\r
1878 /*-----------------------------------------------------------*/\r
1879 \r
1880 #if ( ( INCLUDE_vTaskDelete == 1 ) || ( INCLUDE_vTaskCleanUpResources == 1 ) )\r
1881 \r
1882         static void prvDeleteTCB( tskTCB *pxTCB )\r
1883         {\r
1884                 /* Free up the memory allocated by the scheduler for the task.  It is up to\r
1885                 the task to free any memory allocated at the application level. */\r
1886                 vPortFree( pxTCB->pxStack );\r
1887                 vPortFree( pxTCB );\r
1888         }\r
1889 \r
1890 #endif\r
1891 \r
1892 \r
1893 /*-----------------------------------------------------------*/\r
1894 \r
1895 #if ( INCLUDE_xTaskGetCurrentTaskHandle == 1 )\r
1896 \r
1897         xTaskHandle xTaskGetCurrentTaskHandle( void )\r
1898         {\r
1899                 /* A critical section is not required as this is not called from\r
1900                 an interrupt and the current TCB will always be the same for any\r
1901                 individual execution thread. */\r
1902                 return pxCurrentTCB;\r
1903         }\r
1904 \r
1905 #endif\r
1906 \r
1907 /*-----------------------------------------------------------*/\r
1908 \r
1909 #if ( INCLUDE_xTaskGetSchedulerState == 1 )\r
1910 \r
1911         portBASE_TYPE xTaskGetSchedulerState( void )\r
1912         {\r
1913         portBASE_TYPE xReturn;\r
1914         \r
1915                 if( xSchedulerRunning == pdFALSE )\r
1916                 {\r
1917                         xReturn = taskSCHEDULER_NOT_STARTED;\r
1918                 }\r
1919                 else\r
1920                 {\r
1921                         if( uxSchedulerSuspended == ( unsigned portBASE_TYPE ) pdFALSE )\r
1922                         {\r
1923                                 xReturn = taskSCHEDULER_RUNNING;\r
1924                         }\r
1925                         else\r
1926                         {\r
1927                                 xReturn = taskSCHEDULER_SUSPENDED;\r
1928                         }\r
1929                 }\r
1930                 \r
1931                 return xReturn;\r
1932         }\r
1933 \r
1934 #endif\r
1935 /*-----------------------------------------------------------*/\r
1936 \r
1937 #if ( configUSE_MUTEXES == 1 )\r
1938         \r
1939         void vTaskPriorityInherit( xTaskHandle * const pxMutexHolder )\r
1940         {\r
1941         tskTCB * const pxTCB = ( tskTCB * ) pxMutexHolder;\r
1942 \r
1943                 if( pxTCB->uxPriority < pxCurrentTCB->uxPriority )\r
1944                 {\r
1945                         /* Adjust the mutex holder state to account for its new priority. */\r
1946                         listSET_LIST_ITEM_VALUE( &( pxTCB->xEventListItem ), configMAX_PRIORITIES - ( portTickType ) pxCurrentTCB->uxPriority );\r
1947 \r
1948                         /* If the task being modified is in the ready state it will need to\r
1949                         be moved in to a new list. */\r
1950                         if( listIS_CONTAINED_WITHIN( &( pxReadyTasksLists[ pxTCB->uxPriority ] ), &( pxTCB->xGenericListItem ) ) )\r
1951                         {\r
1952                                 vListRemove( &( pxTCB->xGenericListItem ) );\r
1953 \r
1954                                 /* Inherit the priority before being moved into the new list. */\r
1955                                 pxTCB->uxPriority = pxCurrentTCB->uxPriority;\r
1956                                 prvAddTaskToReadyQueue( pxTCB );\r
1957                         }\r
1958                         else\r
1959                         {\r
1960                                 /* Just inherit the priority. */\r
1961                                 pxTCB->uxPriority = pxCurrentTCB->uxPriority;\r
1962                         }\r
1963                 }\r
1964         }\r
1965 \r
1966 #endif\r
1967 /*-----------------------------------------------------------*/\r
1968 \r
1969 #if ( configUSE_MUTEXES == 1 )  \r
1970 \r
1971         void vTaskPriorityDisinherit( xTaskHandle * const pxMutexHolder )\r
1972         {\r
1973         tskTCB * const pxTCB = ( tskTCB * ) pxMutexHolder;\r
1974 \r
1975                 if( pxMutexHolder != NULL )\r
1976                 {\r
1977                         if( pxTCB->uxPriority != pxTCB->uxBasePriority )\r
1978                         {\r
1979                                 /* We must be the running task to be able to give the mutex back.\r
1980                                 Remove ourselves from the ready list we currently appear in. */\r
1981                                 vListRemove( &( pxTCB->xGenericListItem ) );\r
1982 \r
1983                                 /* Disinherit the priority before adding ourselves into the new\r
1984                                 ready list. */\r
1985                                 pxTCB->uxPriority = pxTCB->uxBasePriority;\r
1986                                 listSET_LIST_ITEM_VALUE( &( pxTCB->xEventListItem ), configMAX_PRIORITIES - ( portTickType ) pxTCB->uxPriority );\r
1987                                 prvAddTaskToReadyQueue( pxTCB );\r
1988                         }\r
1989                 }\r
1990         }\r
1991 \r
1992 #endif\r
1993 /*-----------------------------------------------------------*/\r
1994 \r
1995 #if ( portCRITICAL_NESTING_IN_TCB == 1 )\r
1996 \r
1997         void vTaskEnterCritical( void )\r
1998         {\r
1999                 portDISABLE_INTERRUPTS();\r
2000 \r
2001                 if( xSchedulerRunning != pdFALSE )\r
2002                 {\r
2003                         pxCurrentTCB->uxCriticalNesting++;\r
2004                 }\r
2005         }\r
2006 \r
2007 #endif\r
2008 /*-----------------------------------------------------------*/\r
2009 \r
2010 #if ( portCRITICAL_NESTING_IN_TCB == 1 )\r
2011 \r
2012 void vTaskExitCritical( void )\r
2013 {\r
2014         if( xSchedulerRunning != pdFALSE )\r
2015         {\r
2016                 if( pxCurrentTCB->uxCriticalNesting > 0 )\r
2017                 {\r
2018                         pxCurrentTCB->uxCriticalNesting--;\r
2019 \r
2020                         if( pxCurrentTCB->uxCriticalNesting == 0 )\r
2021                         {\r
2022                                 portENABLE_INTERRUPTS();\r
2023                         }\r
2024                 }\r
2025         }\r
2026 }\r
2027 \r
2028 #endif\r
2029 /*-----------------------------------------------------------*/\r
2030 \r
2031 \r
2032         \r
2033 \r