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