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

   1 /*\r
   2         FreeRTOS.org V5.2.0 - 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 it \r
   7         under the terms of the GNU General Public License (version 2) as published\r
   8         by the Free Software Foundation and modified by the FreeRTOS exception.\r
   9 \r
  10         FreeRTOS.org is distributed in the hope that it will be useful, but WITHOUT\r
  11         ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or \r
  12         FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for \r
  13         more details.\r
  14 \r
  15         You should have received a copy of the GNU General Public License along \r
  16         with FreeRTOS.org; if not, write to the Free Software Foundation, Inc., 59 \r
  17         Temple Place, Suite 330, Boston, MA  02111-1307  USA.\r
  18 \r
  19         A special exception to the GPL is included to allow you to distribute a \r
  20         combined work that includes FreeRTOS.org without being obliged to provide\r
  21         the source code for any proprietary components.  See the licensing section\r
  22         of http://www.FreeRTOS.org for full details.\r
  23 \r
  24 \r
  25         ***************************************************************************\r
  26         *                                                                         *\r
  27         * Get the FreeRTOS eBook!  See http://www.FreeRTOS.org/Documentation      *\r
  28         *                                                                         *\r
  29         * This is a concise, step by step, 'hands on' guide that describes both   *\r
  30         * general multitasking concepts and FreeRTOS specifics. It presents and   *\r
  31         * explains numerous examples that are written using the FreeRTOS API.     *\r
  32         * Full source code for all the examples is provided in an accompanying    *\r
  33         * .zip file.                                                              *\r
  34         *                                                                         *\r
  35         ***************************************************************************\r
  36 \r
  37         1 tab == 4 spaces!\r
  38 \r
  39         Please ensure to read the configuration and relevant port sections of the\r
  40         online documentation.\r
  41 \r
  42         http://www.FreeRTOS.org - Documentation, latest information, license and\r
  43         contact details.\r
  44 \r
  45         http://www.SafeRTOS.com - A version that is certified for use in safety\r
  46         critical systems.\r
  47 \r
  48         http://www.OpenRTOS.com - Commercial support, development, porting,\r
  49         licensing and training services.\r
  50 */\r
  51 \r
  52 \r
  53 #include <stdio.h>\r
  54 #include <stdlib.h>\r
  55 #include <string.h>\r
  56 \r
  57 #include "FreeRTOS.h"\r
  58 #include "task.h"\r
  59 #include "StackMacros.h"\r
  60 \r
  61 /*\r
  62  * Macro to define the amount of stack available to the idle task.\r
  63  */\r
  64 #define tskIDLE_STACK_SIZE      configMINIMAL_STACK_SIZE\r
  65 \r
  66 /*\r
  67  * Task control block.  A task control block (TCB) is allocated to each task,\r
  68  * and stores the context of the task.\r
  69  */\r
  70 typedef struct tskTaskControlBlock\r
  71 {\r
  72         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
  73         xListItem                               xGenericListItem;       /*< List item used to place the TCB in ready and blocked queues. */\r
  74         xListItem                               xEventListItem;         /*< List item used to place the TCB in event lists. */\r
  75         unsigned portBASE_TYPE  uxPriority;                     /*< The priority of the task where 0 is the lowest priority. */\r
  76         portSTACK_TYPE                  *pxStack;                       /*< Points to the start of the stack. */\r
  77         signed portCHAR                 pcTaskName[ configMAX_TASK_NAME_LEN ];/*< Descriptive name given to the task when created.  Facilitates debugging only. */\r
  78 \r
  79         #if ( portSTACK_GROWTH > 0 )\r
  80                 portSTACK_TYPE *pxEndOfStack;                   /*< Used for stack overflow checking on architectures where the stack grows up from low memory. */\r
  81         #endif\r
  82 \r
  83         #if ( portCRITICAL_NESTING_IN_TCB == 1 )\r
  84                 unsigned portBASE_TYPE uxCriticalNesting;\r
  85         #endif\r
  86 \r
  87         #if ( configUSE_TRACE_FACILITY == 1 )\r
  88                 unsigned portBASE_TYPE  uxTCBNumber;            /*< This is used for tracing the scheduler and making debugging easier only. */\r
  89         #endif  \r
  90                 \r
  91         #if ( configUSE_MUTEXES == 1 )\r
  92                 unsigned portBASE_TYPE uxBasePriority;\r
  93         #endif\r
  94 \r
  95         #if ( configUSE_APPLICATION_TASK_TAG == 1 )\r
  96                 pdTASK_HOOK_CODE pxTaskTag;\r
  97         #endif\r
  98                 \r
  99 } tskTCB;\r
 100 \r
 101 /*\r
 102  * Some kernel aware debuggers require data to be viewed to be global, rather\r
 103  * than file scope.\r
 104  */\r
 105 #ifdef portREMOVE_STATIC_QUALIFIER\r
 106         #define static\r
 107 #endif\r
 108 \r
 109 /*lint -e956 */\r
 110 \r
 111 tskTCB * volatile pxCurrentTCB = NULL;                                  \r
 112 \r
 113 /* Lists for ready and blocked tasks. --------------------*/\r
 114 \r
 115 static xList pxReadyTasksLists[ configMAX_PRIORITIES ]; /*< Prioritised ready tasks. */\r
 116 static xList xDelayedTaskList1;                                                 /*< Delayed tasks. */\r
 117 static xList xDelayedTaskList2;                                                 /*< Delayed tasks (two lists are used - one for delays that have overflowed the current tick count. */\r
 118 static xList * volatile pxDelayedTaskList;                              /*< Points to the delayed task list currently being used. */\r
 119 static xList * volatile pxOverflowDelayedTaskList;              /*< Points to the delayed task list currently being used to hold tasks that have overflowed the current tick count. */\r
 120 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
 121 \r
 122 #if ( INCLUDE_vTaskDelete == 1 )\r
 123 \r
 124         static volatile xList xTasksWaitingTermination;         /*< Tasks that have been deleted - but the their memory not yet freed. */\r
 125         static volatile unsigned portBASE_TYPE uxTasksDeleted = ( unsigned portBASE_TYPE ) 0;\r
 126 \r
 127 #endif\r
 128 \r
 129 #if ( INCLUDE_vTaskSuspend == 1 )\r
 130 \r
 131         static xList xSuspendedTaskList;                                        /*< Tasks that are currently suspended. */\r
 132 \r
 133 #endif\r
 134 \r
 135 /* File private variables. --------------------------------*/\r
 136 static volatile unsigned portBASE_TYPE uxCurrentNumberOfTasks   = ( unsigned portBASE_TYPE ) 0;\r
 137 static volatile portTickType xTickCount                                                 = ( portTickType ) 0;\r
 138 static unsigned portBASE_TYPE uxTopUsedPriority                                 = tskIDLE_PRIORITY;\r
 139 static volatile unsigned portBASE_TYPE uxTopReadyPriority               = tskIDLE_PRIORITY;\r
 140 static volatile signed portBASE_TYPE xSchedulerRunning                  = pdFALSE;\r
 141 static volatile unsigned portBASE_TYPE uxSchedulerSuspended             = ( unsigned portBASE_TYPE ) pdFALSE;\r
 142 static volatile unsigned portBASE_TYPE uxMissedTicks                    = ( unsigned portBASE_TYPE ) 0;\r
 143 static volatile portBASE_TYPE xMissedYield                                              = ( portBASE_TYPE ) pdFALSE;\r
 144 static volatile portBASE_TYPE xNumOfOverflows                                   = ( portBASE_TYPE ) 0;\r
 145 static unsigned portBASE_TYPE uxTaskNumber = 0;\r
 146 \r
 147 /* Debugging and trace facilities private variables and macros. ------------*/\r
 148 \r
 149 /*\r
 150  * The value used to fill the stack of a task when the task is created.  This\r
 151  * is used purely for checking the high water mark for tasks.\r
 152  */\r
 153 #define tskSTACK_FILL_BYTE      ( 0xa5 )\r
 154 \r
 155 /*\r
 156  * Macros used by vListTask to indicate which state a task is in.\r
 157  */\r
 158 #define tskBLOCKED_CHAR         ( ( signed portCHAR ) 'B' )\r
 159 #define tskREADY_CHAR           ( ( signed portCHAR ) 'R' )\r
 160 #define tskDELETED_CHAR         ( ( signed portCHAR ) 'D' )\r
 161 #define tskSUSPENDED_CHAR       ( ( signed portCHAR ) 'S' )\r
 162 \r
 163 /*\r
 164  * Macros and private variables used by the trace facility.\r
 165  */\r
 166 #if ( configUSE_TRACE_FACILITY == 1 )\r
 167 \r
 168         #define tskSIZE_OF_EACH_TRACE_LINE                      ( ( unsigned portLONG ) ( sizeof( unsigned portLONG ) + sizeof( unsigned portLONG ) ) )\r
 169         static volatile signed portCHAR * volatile pcTraceBuffer;\r
 170         static signed portCHAR *pcTraceBufferStart;\r
 171         static signed portCHAR *pcTraceBufferEnd;\r
 172         static signed portBASE_TYPE xTracing = pdFALSE;\r
 173         static unsigned portBASE_TYPE uxPreviousTask = 255;\r
 174         static portCHAR pcStatusString[ 50 ];\r
 175 #endif\r
 176 \r
 177 /*-----------------------------------------------------------*/\r
 178 \r
 179 /*\r
 180  * Macro that writes a trace of scheduler activity to a buffer.  This trace\r
 181  * shows which task is running when and is very useful as a debugging tool.\r
 182  * As this macro is called each context switch it is a good idea to undefine\r
 183  * it if not using the facility.\r
 184  */\r
 185 #if ( configUSE_TRACE_FACILITY == 1 )\r
 186 \r
 187         #define vWriteTraceToBuffer()                                                                                                                                   \\r
 188         {                                                                                                                                                                                               \\r
 189                 if( xTracing )                                                                                                                                                          \\r
 190                 {                                                                                                                                                                                       \\r
 191                         if( uxPreviousTask != pxCurrentTCB->uxTCBNumber )                                                                               \\r
 192                         {                                                                                                                                                                               \\r
 193                                 if( ( pcTraceBuffer + tskSIZE_OF_EACH_TRACE_LINE ) < pcTraceBufferEnd )                         \\r
 194                                 {                                                                                                                                                                       \\r
 195                                         uxPreviousTask = pxCurrentTCB->uxTCBNumber;                                                                             \\r
 196                                         *( unsigned portLONG * ) pcTraceBuffer = ( unsigned portLONG ) xTickCount;              \\r
 197                                         pcTraceBuffer += sizeof( unsigned portLONG );                                                                   \\r
 198                                         *( unsigned portLONG * ) pcTraceBuffer = ( unsigned portLONG ) uxPreviousTask;  \\r
 199                                         pcTraceBuffer += sizeof( unsigned portLONG );                                                                   \\r
 200                                 }                                                                                                                                                                       \\r
 201                                 else                                                                                                                                                            \\r
 202                                 {                                                                                                                                                                       \\r
 203                                         xTracing = pdFALSE;                                                                                                                             \\r
 204                                 }                                                                                                                                                                       \\r
 205                         }                                                                                                                                                                               \\r
 206                 }                                                                                                                                                                                       \\r
 207         }\r
 208 \r
 209 #else\r
 210 \r
 211         #define vWriteTraceToBuffer()\r
 212 \r
 213 #endif\r
 214 /*-----------------------------------------------------------*/\r
 215 \r
 216 /*\r
 217  * Place the task represented by pxTCB into the appropriate ready queue for\r
 218  * the task.  It is inserted at the end of the list.  One quirk of this is\r
 219  * that if the task being inserted is at the same priority as the currently\r
 220  * executing task, then it will only be rescheduled after the currently\r
 221  * executing task has been rescheduled.\r
 222  */\r
 223 #define prvAddTaskToReadyQueue( pxTCB )                                                                                                                                                 \\r
 224 {                                                                                                                                                                                                                               \\r
 225         if( pxTCB->uxPriority > uxTopReadyPriority )                                                                                                                            \\r
 226         {                                                                                                                                                                                                                       \\r
 227                 uxTopReadyPriority = pxTCB->uxPriority;                                                                                                                                 \\r
 228         }                                                                                                                                                                                                                       \\r
 229         vListInsertEnd( ( xList * ) &( pxReadyTasksLists[ pxTCB->uxPriority ] ), &( pxTCB->xGenericListItem ) );        \\r
 230 }\r
 231 /*-----------------------------------------------------------*/         \r
 232 \r
 233 /*\r
 234  * Macro that looks at the list of tasks that are currently delayed to see if\r
 235  * any require waking.\r
 236  *\r
 237  * Tasks are stored in the queue in the order of their wake time - meaning\r
 238  * once one tasks has been found whose timer has not expired we need not look\r
 239  * any further down the list.\r
 240  */\r
 241 #define prvCheckDelayedTasks()                                                                                                                                                                          \\r
 242 {                                                                                                                                                                                                                                       \\r
 243 register tskTCB *pxTCB;                                                                                                                                                                                         \\r
 244                                                                                                                                                                                                                                         \\r
 245         while( ( pxTCB = ( tskTCB * ) listGET_OWNER_OF_HEAD_ENTRY( pxDelayedTaskList ) ) != NULL )                                              \\r
 246         {                                                                                                                                                                                                                               \\r
 247                 if( xTickCount < listGET_LIST_ITEM_VALUE( &( pxTCB->xGenericListItem ) ) )                                                                      \\r
 248                 {                                                                                                                                                                                                                       \\r
 249                         break;                                                                                                                                                                                                  \\r
 250                 }                                                                                                                                                                                                                       \\r
 251                 vListRemove( &( pxTCB->xGenericListItem ) );                                                                                                                            \\r
 252                 /* Is the task waiting on an event also? */                                                                                                                                     \\r
 253                 if( pxTCB->xEventListItem.pvContainer )                                                                                                                                         \\r
 254                 {                                                                                                                                                                                                                       \\r
 255                         vListRemove( &( pxTCB->xEventListItem ) );                                                                                                                              \\r
 256                 }                                                                                                                                                                                                                       \\r
 257                 prvAddTaskToReadyQueue( pxTCB );                                                                                                                                                        \\r
 258         }                                                                                                                                                                                                                               \\r
 259 }\r
 260 /*-----------------------------------------------------------*/\r
 261 \r
 262 /*\r
 263  * Several functions take an xTaskHandle parameter that can optionally be NULL,\r
 264  * where NULL is used to indicate that the handle of the currently executing\r
 265  * task should be used in place of the parameter.  This macro simply checks to\r
 266  * see if the parameter is NULL and returns a pointer to the appropriate TCB.\r
 267  */\r
 268 #define prvGetTCBFromHandle( pxHandle ) ( ( pxHandle == NULL ) ? ( tskTCB * ) pxCurrentTCB : ( tskTCB * ) pxHandle )\r
 269 \r
 270 \r
 271 /* File private functions. --------------------------------*/\r
 272 \r
 273 /*\r
 274  * Utility to ready a TCB for a given task.  Mainly just copies the parameters\r
 275  * into the TCB structure.\r
 276  */\r
 277 static void prvInitialiseTCBVariables( tskTCB *pxTCB, const signed portCHAR * const pcName, unsigned portBASE_TYPE uxPriority );\r
 278 \r
 279 /*\r
 280  * Utility to ready all the lists used by the scheduler.  This is called\r
 281  * automatically upon the creation of the first task.\r
 282  */\r
 283 static void prvInitialiseTaskLists( void );\r
 284 \r
 285 /*\r
 286  * The idle task, which as all tasks is implemented as a never ending loop.\r
 287  * The idle task is automatically created and added to the ready lists upon\r
 288  * creation of the first user task.\r
 289  *\r
 290  * The portTASK_FUNCTION_PROTO() macro is used to allow port/compiler specific\r
 291  * language extensions.  The equivalent prototype for this function is:\r
 292  *\r
 293  * void prvIdleTask( void *pvParameters );\r
 294  *\r
 295  */\r
 296 static portTASK_FUNCTION_PROTO( prvIdleTask, pvParameters );\r
 297 \r
 298 /*\r
 299  * Utility to free all memory allocated by the scheduler to hold a TCB,\r
 300  * including the stack pointed to by the TCB.\r
 301  *\r
 302  * This does not free memory allocated by the task itself (i.e. memory\r
 303  * allocated by calls to pvPortMalloc from within the tasks application code).\r
 304  */\r
 305 #if ( ( INCLUDE_vTaskDelete == 1 ) || ( INCLUDE_vTaskCleanUpResources == 1 ) )\r
 306         static void prvDeleteTCB( tskTCB *pxTCB );\r
 307 #endif\r
 308 \r
 309 /*\r
 310  * Used only by the idle task.  This checks to see if anything has been placed\r
 311  * in the list of tasks waiting to be deleted.  If so the task is cleaned up\r
 312  * and its TCB deleted.\r
 313  */\r
 314 static void prvCheckTasksWaitingTermination( void );\r
 315 \r
 316 /*\r
 317  * Allocates memory from the heap for a TCB and associated stack.  Checks the\r
 318  * allocation was successful.\r
 319  */\r
 320 static tskTCB *prvAllocateTCBAndStack( unsigned portSHORT usStackDepth );\r
 321 \r
 322 /*\r
 323  * Called from vTaskList.  vListTasks details all the tasks currently under\r
 324  * control of the scheduler.  The tasks may be in one of a number of lists.\r
 325  * prvListTaskWithinSingleList accepts a list and details the tasks from\r
 326  * within just that list.\r
 327  *\r
 328  * THIS FUNCTION IS INTENDED FOR DEBUGGING ONLY, AND SHOULD NOT BE CALLED FROM\r
 329  * NORMAL APPLICATION CODE.\r
 330  */\r
 331 #if ( configUSE_TRACE_FACILITY == 1 )\r
 332 \r
 333         static void prvListTaskWithinSingleList( const signed portCHAR *pcWriteBuffer, xList *pxList, signed portCHAR cStatus );\r
 334 \r
 335 #endif\r
 336 \r
 337 /*\r
 338  * When a task is created, the stack of the task is filled with a known value.\r
 339  * This function determines the 'high water mark' of the task stack by\r
 340  * determining how much of the stack remains at the original preset value.\r
 341  */\r
 342 #if ( ( configUSE_TRACE_FACILITY == 1 ) || ( INCLUDE_uxTaskGetStackHighWaterMark == 1 ) )\r
 343 \r
 344         unsigned portSHORT usTaskCheckFreeStackSpace( const unsigned portCHAR * pucStackByte );\r
 345 \r
 346 #endif\r
 347 \r
 348 \r
 349 /*lint +e956 */\r
 350 \r
 351 \r
 352 \r
 353 /*-----------------------------------------------------------\r
 354  * TASK CREATION API documented in task.h\r
 355  *----------------------------------------------------------*/\r
 356 \r
 357 signed portBASE_TYPE xTaskCreate( pdTASK_CODE pvTaskCode, const signed portCHAR * const pcName, unsigned portSHORT usStackDepth, void *pvParameters, unsigned portBASE_TYPE uxPriority, xTaskHandle *pxCreatedTask )\r
 358 {\r
 359 signed portBASE_TYPE xReturn;\r
 360 tskTCB * pxNewTCB;\r
 361 \r
 362         /* Allocate the memory required by the TCB and stack for the new task.\r
 363         checking that the allocation was successful. */\r
 364         pxNewTCB = prvAllocateTCBAndStack( usStackDepth );\r
 365 \r
 366         if( pxNewTCB != NULL )\r
 367         {               \r
 368                 portSTACK_TYPE *pxTopOfStack;\r
 369 \r
 370                 /* Setup the newly allocated TCB with the initial state of the task. */\r
 371                 prvInitialiseTCBVariables( pxNewTCB, pcName, uxPriority );\r
 372 \r
 373                 /* Calculate the top of stack address.  This depends on whether the\r
 374                 stack grows from high memory to low (as per the 80x86) or visa versa.\r
 375                 portSTACK_GROWTH is used to make the result positive or negative as\r
 376                 required by the port. */\r
 377                 #if portSTACK_GROWTH < 0\r
 378                 {\r
 379                         pxTopOfStack = pxNewTCB->pxStack + ( usStackDepth - 1 );\r
 380                 }\r
 381                 #else\r
 382                 {\r
 383                         pxTopOfStack = pxNewTCB->pxStack;       \r
 384 \r
 385                         /* If we want to use stack checking on architectures that use\r
 386                         a positive stack growth direction then we also need to store the\r
 387                         other extreme of the stack space. */\r
 388                         pxNewTCB->pxEndOfStack = pxNewTCB->pxStack + ( usStackDepth - 1 );\r
 389                 }\r
 390                 #endif\r
 391 \r
 392                 /* Initialize the TCB stack to look as if the task was already running,\r
 393                 but had been interrupted by the scheduler.  The return address is set\r
 394                 to the start of the task function. Once the stack has been initialised\r
 395                 the     top of stack variable is updated. */\r
 396                 pxNewTCB->pxTopOfStack = pxPortInitialiseStack( pxTopOfStack, pvTaskCode, pvParameters );\r
 397 \r
 398                 /* We are going to manipulate the task queues to add this task to a\r
 399                 ready list, so must make sure no interrupts occur. */\r
 400                 portENTER_CRITICAL();\r
 401                 {\r
 402                         uxCurrentNumberOfTasks++;\r
 403                         if( uxCurrentNumberOfTasks == ( unsigned portBASE_TYPE ) 1 )\r
 404                         {\r
 405                                 /* As this is the first task it must also be the current task. */\r
 406                                 pxCurrentTCB =  pxNewTCB;\r
 407 \r
 408                                 /* This is the first task to be created so do the preliminary\r
 409                                 initialisation required.  We will not recover if this call\r
 410                                 fails, but we will report the failure. */\r
 411                                 prvInitialiseTaskLists();\r
 412                         }\r
 413                         else\r
 414                         {       \r
 415                                 /* If the scheduler is not already running, make this task the\r
 416                                 current task if it is the highest priority task to be created\r
 417                                 so far. */\r
 418                                 if( xSchedulerRunning == pdFALSE )\r
 419                                 {\r
 420                                         if( pxCurrentTCB->uxPriority <= uxPriority )\r
 421                                         {\r
 422                                                 pxCurrentTCB = pxNewTCB;        \r
 423                                         }\r
 424                                 }\r
 425                         }                               \r
 426 \r
 427                         /* Remember the top priority to make context switching faster.  Use\r
 428                         the priority in pxNewTCB as this has been capped to a valid value. */\r
 429                         if( pxNewTCB->uxPriority > uxTopUsedPriority )\r
 430                         {\r
 431                                 uxTopUsedPriority = pxNewTCB->uxPriority;\r
 432                         }\r
 433 \r
 434                         #if ( configUSE_TRACE_FACILITY == 1 )\r
 435                         {\r
 436                                 /* Add a counter into the TCB for tracing only. */\r
 437                                 pxNewTCB->uxTCBNumber = uxTaskNumber;\r
 438                         }\r
 439                         #endif\r
 440                         uxTaskNumber++;\r
 441 \r
 442                         prvAddTaskToReadyQueue( pxNewTCB );\r
 443 \r
 444                         xReturn = pdPASS;\r
 445                         traceTASK_CREATE( pxNewTCB );\r
 446                 }\r
 447                 portEXIT_CRITICAL();\r
 448         }\r
 449         else\r
 450         {\r
 451                 xReturn = errCOULD_NOT_ALLOCATE_REQUIRED_MEMORY;\r
 452                 traceTASK_CREATE_FAILED( pxNewTCB );\r
 453         }\r
 454 \r
 455         if( xReturn == pdPASS )\r
 456         {\r
 457                 if( ( void * ) pxCreatedTask != NULL )\r
 458                 {\r
 459                         /* Pass the TCB out - in an anonymous way.  The calling function/\r
 460                         task can use this as a handle to delete the task later if\r
 461                         required.*/\r
 462                         *pxCreatedTask = ( xTaskHandle ) pxNewTCB;\r
 463                 }\r
 464 \r
 465                 if( xSchedulerRunning != pdFALSE )\r
 466                 {\r
 467                         /* If the created task is of a higher priority than the current task\r
 468                         then it should run now. */\r
 469                         if( pxCurrentTCB->uxPriority < uxPriority )\r
 470                         {\r
 471                                 taskYIELD();\r
 472                         }\r
 473                 }\r
 474         }\r
 475 \r
 476         return xReturn;\r
 477 }\r
 478 /*-----------------------------------------------------------*/\r
 479 \r
 480 #if ( INCLUDE_vTaskDelete == 1 )\r
 481 \r
 482         void vTaskDelete( xTaskHandle pxTaskToDelete )\r
 483         {\r
 484         tskTCB *pxTCB;\r
 485 \r
 486                 taskENTER_CRITICAL();\r
 487                 {\r
 488                         /* Ensure a yield is performed if the current task is being\r
 489                         deleted. */\r
 490                         if( pxTaskToDelete == pxCurrentTCB )\r
 491                         {\r
 492                                 pxTaskToDelete = NULL;\r
 493                         }\r
 494 \r
 495                         /* If null is passed in here then we are deleting ourselves. */\r
 496                         pxTCB = prvGetTCBFromHandle( pxTaskToDelete );\r
 497 \r
 498                         traceTASK_DELETE( pxTCB );\r
 499 \r
 500                         /* Remove task from the ready list and place in the     termination list.\r
 501                         This will stop the task from be scheduled.  The idle task will check\r
 502                         the termination list and free up any memory allocated by the\r
 503                         scheduler for the TCB and stack. */\r
 504                         vListRemove( &( pxTCB->xGenericListItem ) );\r
 505 \r
 506                         /* Is the task waiting on an event also? */                                                                                             \r
 507                         if( pxTCB->xEventListItem.pvContainer )\r
 508                         {\r
 509                                 vListRemove( &( pxTCB->xEventListItem ) );\r
 510                         }\r
 511 \r
 512                         vListInsertEnd( ( xList * ) &xTasksWaitingTermination, &( pxTCB->xGenericListItem ) );\r
 513 \r
 514                         /* Increment the ucTasksDeleted variable so the idle task knows\r
 515                         there is a task that has been deleted and that it should therefore\r
 516                         check the xTasksWaitingTermination list. */\r
 517                         ++uxTasksDeleted;\r
 518 \r
 519                         /* Increment the uxTaskNumberVariable also so kernel aware debuggers\r
 520                         can detect that the task lists need re-generating. */                   \r
 521                         uxTaskNumber++;\r
 522                 }\r
 523                 taskEXIT_CRITICAL();\r
 524 \r
 525                 /* Force a reschedule if we have just deleted the current task. */\r
 526                 if( xSchedulerRunning != pdFALSE )\r
 527                 {\r
 528                         if( ( void * ) pxTaskToDelete == NULL )\r
 529                         {\r
 530                                 taskYIELD();\r
 531                         }\r
 532                 }\r
 533         }\r
 534 \r
 535 #endif\r
 536 \r
 537 \r
 538 \r
 539 \r
 540 \r
 541 \r
 542 /*-----------------------------------------------------------\r
 543  * TASK CONTROL API documented in task.h\r
 544  *----------------------------------------------------------*/\r
 545 \r
 546 #if ( INCLUDE_vTaskDelayUntil == 1 )\r
 547 \r
 548         void vTaskDelayUntil( portTickType * const pxPreviousWakeTime, portTickType xTimeIncrement )\r
 549         {\r
 550         portTickType xTimeToWake;\r
 551         portBASE_TYPE xAlreadyYielded, xShouldDelay = pdFALSE;\r
 552 \r
 553                 vTaskSuspendAll();\r
 554                 {\r
 555                         /* Generate the tick time at which the task wants to wake. */\r
 556                         xTimeToWake = *pxPreviousWakeTime + xTimeIncrement;\r
 557 \r
 558                         if( xTickCount < *pxPreviousWakeTime )\r
 559                         {\r
 560                                 /* The tick count has overflowed since this function was\r
 561                                 lasted called.  In this case the only time we should ever\r
 562                                 actually delay is if the wake time has also     overflowed,\r
 563                                 and the wake time is greater than the tick time.  When this\r
 564                                 is the case it is as if neither time had overflowed. */\r
 565                                 if( ( xTimeToWake < *pxPreviousWakeTime ) && ( xTimeToWake > xTickCount ) )\r
 566                                 {\r
 567                                         xShouldDelay = pdTRUE;\r
 568                                 }\r
 569                         }\r
 570                         else\r
 571                         {\r
 572                                 /* The tick time has not overflowed.  In this case we will\r
 573                                 delay if either the wake time has overflowed, and/or the\r
 574                                 tick time is less than the wake time. */\r
 575                                 if( ( xTimeToWake < *pxPreviousWakeTime ) || ( xTimeToWake > xTickCount ) )\r
 576                                 {\r
 577                                         xShouldDelay = pdTRUE;\r
 578                                 }\r
 579                         }\r
 580 \r
 581                         /* Update the wake time ready for the next call. */\r
 582                         *pxPreviousWakeTime = xTimeToWake;\r
 583 \r
 584                         if( xShouldDelay )\r
 585                         {\r
 586                                 traceTASK_DELAY_UNTIL();\r
 587 \r
 588                                 /* We must remove ourselves from the ready list before adding\r
 589                                 ourselves to the blocked list as the same list item is used for\r
 590                                 both lists. */\r
 591                                 vListRemove( ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );\r
 592 \r
 593                                 /* The list item will be inserted in wake time order. */\r
 594                                 listSET_LIST_ITEM_VALUE( &( pxCurrentTCB->xGenericListItem ), xTimeToWake );\r
 595 \r
 596                                 if( xTimeToWake < xTickCount )\r
 597                                 {\r
 598                                         /* Wake time has overflowed.  Place this item in the\r
 599                                         overflow list. */\r
 600                                         vListInsert( ( xList * ) pxOverflowDelayedTaskList, ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );\r
 601                                 }\r
 602                                 else\r
 603                                 {\r
 604                                         /* The wake time has not overflowed, so we can use the\r
 605                                         current block list. */\r
 606                                         vListInsert( ( xList * ) pxDelayedTaskList, ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );\r
 607                                 }\r
 608                         }\r
 609                 }\r
 610                 xAlreadyYielded = xTaskResumeAll();\r
 611 \r
 612                 /* Force a reschedule if xTaskResumeAll has not already done so, we may\r
 613                 have put ourselves to sleep. */\r
 614                 if( !xAlreadyYielded )\r
 615                 {\r
 616                         taskYIELD();\r
 617                 }\r
 618         }       \r
 619         \r
 620 #endif\r
 621 /*-----------------------------------------------------------*/\r
 622 \r
 623 #if ( INCLUDE_vTaskDelay == 1 )\r
 624 \r
 625         void vTaskDelay( portTickType xTicksToDelay )\r
 626         {\r
 627         portTickType xTimeToWake;\r
 628         signed portBASE_TYPE xAlreadyYielded = pdFALSE;\r
 629 \r
 630                 /* A delay time of zero just forces a reschedule. */\r
 631                 if( xTicksToDelay > ( portTickType ) 0 )\r
 632                 {\r
 633                         vTaskSuspendAll();\r
 634                         {\r
 635                                 traceTASK_DELAY();\r
 636 \r
 637                                 /* A task that is removed from the event list while the\r
 638                                 scheduler is suspended will not get placed in the ready\r
 639                                 list or removed from the blocked list until the scheduler\r
 640                                 is resumed.\r
 641                                 \r
 642                                 This task cannot be in an event list as it is the currently\r
 643                                 executing task. */\r
 644 \r
 645                                 /* Calculate the time to wake - this may overflow but this is\r
 646                                 not a problem. */\r
 647                                 xTimeToWake = xTickCount + xTicksToDelay;\r
 648 \r
 649                                 /* We must remove ourselves from the ready list before adding\r
 650                                 ourselves to the blocked list as the same list item is used for\r
 651                                 both lists. */\r
 652                                 vListRemove( ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );\r
 653 \r
 654                                 /* The list item will be inserted in wake time order. */\r
 655                                 listSET_LIST_ITEM_VALUE( &( pxCurrentTCB->xGenericListItem ), xTimeToWake );\r
 656 \r
 657                                 if( xTimeToWake < xTickCount )\r
 658                                 {\r
 659                                         /* Wake time has overflowed.  Place this item in the\r
 660                                         overflow list. */\r
 661                                         vListInsert( ( xList * ) pxOverflowDelayedTaskList, ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );\r
 662                                 }\r
 663                                 else\r
 664                                 {\r
 665                                         /* The wake time has not overflowed, so we can use the\r
 666                                         current block list. */\r
 667                                         vListInsert( ( xList * ) pxDelayedTaskList, ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );\r
 668                                 }\r
 669                         }\r
 670                         xAlreadyYielded = xTaskResumeAll();\r
 671                 }\r
 672                 \r
 673                 /* Force a reschedule if xTaskResumeAll has not already done so, we may\r
 674                 have put ourselves to sleep. */\r
 675                 if( !xAlreadyYielded )\r
 676                 {\r
 677                         taskYIELD();\r
 678                 }\r
 679         }\r
 680         \r
 681 #endif\r
 682 /*-----------------------------------------------------------*/\r
 683 \r
 684 #if ( INCLUDE_uxTaskPriorityGet == 1 )\r
 685 \r
 686         unsigned portBASE_TYPE uxTaskPriorityGet( xTaskHandle pxTask )\r
 687         {\r
 688         tskTCB *pxTCB;\r
 689         unsigned portBASE_TYPE uxReturn;\r
 690 \r
 691                 taskENTER_CRITICAL();\r
 692                 {\r
 693                         /* If null is passed in here then we are changing the\r
 694                         priority of the calling function. */\r
 695                         pxTCB = prvGetTCBFromHandle( pxTask );\r
 696                         uxReturn = pxTCB->uxPriority;\r
 697                 }\r
 698                 taskEXIT_CRITICAL();\r
 699 \r
 700                 return uxReturn;\r
 701         }\r
 702 \r
 703 #endif\r
 704 /*-----------------------------------------------------------*/\r
 705 \r
 706 #if ( INCLUDE_vTaskPrioritySet == 1 )\r
 707 \r
 708         void vTaskPrioritySet( xTaskHandle pxTask, unsigned portBASE_TYPE uxNewPriority )\r
 709         {\r
 710         tskTCB *pxTCB;\r
 711         unsigned portBASE_TYPE uxCurrentPriority, xYieldRequired = pdFALSE;\r
 712 \r
 713                 /* Ensure the new priority is valid. */\r
 714                 if( uxNewPriority >= configMAX_PRIORITIES )\r
 715                 {\r
 716                         uxNewPriority = configMAX_PRIORITIES - 1;\r
 717                 }\r
 718 \r
 719                 taskENTER_CRITICAL();\r
 720                 {\r
 721                         if( pxTask == pxCurrentTCB )\r
 722                         {\r
 723                                 pxTask = NULL;\r
 724                         }\r
 725 \r
 726                         /* If null is passed in here then we are changing the\r
 727                         priority of the calling function. */\r
 728                         pxTCB = prvGetTCBFromHandle( pxTask );\r
 729                         \r
 730                         traceTASK_PRIORITY_SET( pxTask, uxNewPriority );\r
 731 \r
 732                         #if ( configUSE_MUTEXES == 1 )\r
 733                         {\r
 734                                 uxCurrentPriority = pxTCB->uxBasePriority;\r
 735                         }\r
 736                         #else\r
 737                         {\r
 738                                 uxCurrentPriority = pxTCB->uxPriority;\r
 739                         }\r
 740                         #endif\r
 741 \r
 742                         if( uxCurrentPriority != uxNewPriority )\r
 743                         {\r
 744                                 /* The priority change may have readied a task of higher\r
 745                                 priority than the calling task. */\r
 746                                 if( uxNewPriority > uxCurrentPriority )\r
 747                                 {\r
 748                                         if( pxTask != NULL )\r
 749                                         {\r
 750                                                 /* The priority of another task is being raised.  If we\r
 751                                                 were raising the priority of the currently running task\r
 752                                                 there would be no need to switch as it must have already\r
 753                                                 been the highest priority task. */\r
 754                                                 xYieldRequired = pdTRUE;\r
 755                                         }\r
 756                                 }\r
 757                                 else if( pxTask == NULL )\r
 758                                 {\r
 759                                         /* Setting our own priority down means there may now be another\r
 760                                         task of higher priority that is ready to execute. */\r
 761                                         xYieldRequired = pdTRUE;\r
 762                                 }\r
 763                         \r
 764                                 \r
 765 \r
 766                                 #if ( configUSE_MUTEXES == 1 )\r
 767                                 {\r
 768                                         /* Only change the priority being used if the task is not\r
 769                                         currently using an inherited priority. */\r
 770                                         if( pxTCB->uxBasePriority == pxTCB->uxPriority )\r
 771                                         {\r
 772                                                 pxTCB->uxPriority = uxNewPriority;\r
 773                                         }\r
 774                                         \r
 775                                         /* The base priority gets set whatever. */\r
 776                                         pxTCB->uxBasePriority = uxNewPriority;                                  \r
 777                                 }\r
 778                                 #else\r
 779                                 {\r
 780                                         pxTCB->uxPriority = uxNewPriority;\r
 781                                 }\r
 782                                 #endif\r
 783 \r
 784                                 listSET_LIST_ITEM_VALUE( &( pxTCB->xEventListItem ), ( configMAX_PRIORITIES - ( portTickType ) uxNewPriority ) );\r
 785 \r
 786                                 /* If the task is in the blocked or suspended list we need do\r
 787                                 nothing more than change it's priority variable. However, if\r
 788                                 the task is in a ready list it needs to be removed and placed\r
 789                                 in the queue appropriate to its new priority. */\r
 790                                 if( listIS_CONTAINED_WITHIN( &( pxReadyTasksLists[ uxCurrentPriority ] ), &( pxTCB->xGenericListItem ) ) )\r
 791                                 {\r
 792                                         /* The task is currently in its ready list - remove before adding\r
 793                                         it to it's new ready list.  As we are in a critical section we\r
 794                                         can do this even if the scheduler is suspended. */\r
 795                                         vListRemove( &( pxTCB->xGenericListItem ) );\r
 796                                         prvAddTaskToReadyQueue( pxTCB );\r
 797                                 }                       \r
 798                                 \r
 799                                 if( xYieldRequired == pdTRUE )\r
 800                                 {\r
 801                                         taskYIELD();\r
 802                                 }                               \r
 803                         }\r
 804                 }\r
 805                 taskEXIT_CRITICAL();\r
 806         }\r
 807 \r
 808 #endif\r
 809 /*-----------------------------------------------------------*/\r
 810 \r
 811 #if ( INCLUDE_vTaskSuspend == 1 )\r
 812 \r
 813         void vTaskSuspend( xTaskHandle pxTaskToSuspend )\r
 814         {\r
 815         tskTCB *pxTCB;\r
 816 \r
 817                 taskENTER_CRITICAL();\r
 818                 {\r
 819                         /* Ensure a yield is performed if the current task is being\r
 820                         suspended. */\r
 821                         if( pxTaskToSuspend == pxCurrentTCB )\r
 822                         {\r
 823                                 pxTaskToSuspend = NULL;\r
 824                         }\r
 825 \r
 826                         /* If null is passed in here then we are suspending ourselves. */\r
 827                         pxTCB = prvGetTCBFromHandle( pxTaskToSuspend );\r
 828 \r
 829                         traceTASK_SUSPEND( pxTaskToSuspend );\r
 830 \r
 831                         /* Remove task from the ready/delayed list and place in the     suspended list. */\r
 832                         vListRemove( &( pxTCB->xGenericListItem ) );\r
 833 \r
 834                         /* Is the task waiting on an event also? */                                                                                             \r
 835                         if( pxTCB->xEventListItem.pvContainer )\r
 836                         {\r
 837                                 vListRemove( &( pxTCB->xEventListItem ) );\r
 838                         }\r
 839 \r
 840                         vListInsertEnd( ( xList * ) &xSuspendedTaskList, &( pxTCB->xGenericListItem ) );\r
 841                 }\r
 842                 taskEXIT_CRITICAL();\r
 843 \r
 844                 /* We may have just suspended the current task. */\r
 845                 if( ( void * ) pxTaskToSuspend == NULL )\r
 846                 {\r
 847                         taskYIELD();\r
 848                 }\r
 849         }\r
 850 \r
 851 #endif\r
 852 /*-----------------------------------------------------------*/\r
 853 \r
 854 #if ( INCLUDE_vTaskSuspend == 1 )\r
 855 \r
 856         signed portBASE_TYPE xTaskIsTaskSuspended( xTaskHandle xTask )\r
 857         {\r
 858         portBASE_TYPE xReturn = pdFALSE;\r
 859         const tskTCB * const pxTCB = ( tskTCB * ) xTask;\r
 860 \r
 861                 /* Is the task we are attempting to resume actually in the\r
 862                 suspended list? */\r
 863                 if( listIS_CONTAINED_WITHIN( &xSuspendedTaskList, &( pxTCB->xGenericListItem ) ) != pdFALSE )\r
 864                 {\r
 865                         /* Has the task already been resumed from within an ISR? */\r
 866                         if( listIS_CONTAINED_WITHIN( &xPendingReadyList, &( pxTCB->xEventListItem ) ) != pdTRUE )\r
 867                         {                       \r
 868                                 /* Is it in the suspended list because it is in the\r
 869                                 Suspended state?  It is possible to be in the suspended\r
 870                                 list because it is blocked on a task with no timeout\r
 871                                 specified. */\r
 872                                 if( listIS_CONTAINED_WITHIN( NULL, &( pxTCB->xEventListItem ) ) == pdTRUE )\r
 873                                 {\r
 874                                         xReturn = pdTRUE;\r
 875                                 }\r
 876                         }\r
 877                 }\r
 878 \r
 879                 return xReturn;\r
 880         }\r
 881 \r
 882 #endif\r
 883 /*-----------------------------------------------------------*/\r
 884 \r
 885 #if ( INCLUDE_vTaskSuspend == 1 )\r
 886 \r
 887         void vTaskResume( xTaskHandle pxTaskToResume )\r
 888         {\r
 889         tskTCB *pxTCB;\r
 890 \r
 891                 /* Remove the task from whichever list it is currently in, and place\r
 892                 it in the ready list. */\r
 893                 pxTCB = ( tskTCB * ) pxTaskToResume;\r
 894 \r
 895                 /* The parameter cannot be NULL as it is impossible to resume the\r
 896                 currently executing task. */\r
 897                 if( ( pxTCB != NULL ) && ( pxTCB != pxCurrentTCB ) )\r
 898                 {\r
 899                         taskENTER_CRITICAL();\r
 900                         {\r
 901                                 if( xTaskIsTaskSuspended( pxTCB ) == pdTRUE )\r
 902                                 {\r
 903                                         traceTASK_RESUME( pxTCB );\r
 904 \r
 905                                         /* As we are in a critical section we can access the ready\r
 906                                         lists even if the scheduler is suspended. */\r
 907                                         vListRemove(  &( pxTCB->xGenericListItem ) );\r
 908                                         prvAddTaskToReadyQueue( pxTCB );\r
 909 \r
 910                                         /* We may have just resumed a higher priority task. */\r
 911                                         if( pxTCB->uxPriority >= pxCurrentTCB->uxPriority )\r
 912                                         {\r
 913                                                 /* This yield may not cause the task just resumed to run, but\r
 914                                                 will leave the lists in the correct state for the next yield. */\r
 915                                                 taskYIELD();\r
 916                                         }\r
 917                                 }\r
 918                         }\r
 919                         taskEXIT_CRITICAL();\r
 920                 }\r
 921         }\r
 922 \r
 923 #endif\r
 924 \r
 925 /*-----------------------------------------------------------*/\r
 926 \r
 927 #if ( ( INCLUDE_xTaskResumeFromISR == 1 ) && ( INCLUDE_vTaskSuspend == 1 ) )\r
 928 \r
 929         portBASE_TYPE xTaskResumeFromISR( xTaskHandle pxTaskToResume )\r
 930         {\r
 931         portBASE_TYPE xYieldRequired = pdFALSE;\r
 932         tskTCB *pxTCB;\r
 933 \r
 934                 pxTCB = ( tskTCB * ) pxTaskToResume;\r
 935 \r
 936                 if( xTaskIsTaskSuspended( pxTCB ) == pdTRUE )\r
 937                 {\r
 938                         traceTASK_RESUME_FROM_ISR( pxTCB );\r
 939 \r
 940                         if( uxSchedulerSuspended == ( unsigned portBASE_TYPE ) pdFALSE )\r
 941                         {\r
 942                                 xYieldRequired = ( pxTCB->uxPriority >= pxCurrentTCB->uxPriority );\r
 943                                 vListRemove(  &( pxTCB->xGenericListItem ) );   \r
 944                                 prvAddTaskToReadyQueue( pxTCB );\r
 945                         }\r
 946                         else\r
 947                         {\r
 948                                 /* We cannot access the delayed or ready lists, so will hold this\r
 949                                 task pending until the scheduler is resumed, at which point a\r
 950                                 yield will be performed if necessary. */\r
 951                                 vListInsertEnd( ( xList * ) &( xPendingReadyList ), &( pxTCB->xEventListItem ) );\r
 952                         }\r
 953                 }\r
 954 \r
 955                 return xYieldRequired;\r
 956         }\r
 957 \r
 958 #endif\r
 959 \r
 960 \r
 961 \r
 962 \r
 963 /*-----------------------------------------------------------\r
 964  * PUBLIC SCHEDULER CONTROL documented in task.h\r
 965  *----------------------------------------------------------*/\r
 966 \r
 967 \r
 968 void vTaskStartScheduler( void )\r
 969 {\r
 970 portBASE_TYPE xReturn;\r
 971 \r
 972         /* Add the idle task at the lowest priority. */\r
 973         xReturn = xTaskCreate( prvIdleTask, ( signed portCHAR * ) "IDLE", tskIDLE_STACK_SIZE, ( void * ) NULL, tskIDLE_PRIORITY, ( xTaskHandle * ) NULL );\r
 974 \r
 975         if( xReturn == pdPASS )\r
 976         {\r
 977                 /* Interrupts are turned off here, to ensure a tick does not occur\r
 978                 before or during the call to xPortStartScheduler().  The stacks of\r
 979                 the created tasks contain a status word with interrupts switched on\r
 980                 so interrupts will automatically get re-enabled when the first task\r
 981                 starts to run.\r
 982                 \r
 983                 STEPPING THROUGH HERE USING A DEBUGGER CAN CAUSE BIG PROBLEMS IF THE\r
 984                 DEBUGGER ALLOWS INTERRUPTS TO BE PROCESSED. */\r
 985                 portDISABLE_INTERRUPTS();\r
 986 \r
 987                 xSchedulerRunning = pdTRUE;\r
 988                 xTickCount = ( portTickType ) 0;\r
 989 \r
 990                 /* Setting up the timer tick is hardware specific and thus in the\r
 991                 portable interface. */\r
 992                 if( xPortStartScheduler() )\r
 993                 {\r
 994                         /* Should not reach here as if the scheduler is running the\r
 995                         function will not return. */\r
 996                 }\r
 997                 else\r
 998                 {\r
 999                         /* Should only reach here if a task calls xTaskEndScheduler(). */\r
1000                 }\r
1001         }\r
1002 }\r
1003 /*-----------------------------------------------------------*/\r
1004 \r
1005 void vTaskEndScheduler( void )\r
1006 {\r
1007         /* Stop the scheduler interrupts and call the portable scheduler end\r
1008         routine so the original ISRs can be restored if necessary.  The port\r
1009         layer must ensure interrupts enable     bit is left in the correct state. */\r
1010         portDISABLE_INTERRUPTS();\r
1011         xSchedulerRunning = pdFALSE;\r
1012         vPortEndScheduler();\r
1013 }\r
1014 /*----------------------------------------------------------*/\r
1015 \r
1016 void vTaskSuspendAll( void )\r
1017 {\r
1018         /* A critical section is not required as the variable is of type\r
1019         portBASE_TYPE. */\r
1020         ++uxSchedulerSuspended;\r
1021 }\r
1022 /*----------------------------------------------------------*/\r
1023 \r
1024 signed portBASE_TYPE xTaskResumeAll( void )\r
1025 {\r
1026 register tskTCB *pxTCB;\r
1027 signed portBASE_TYPE xAlreadyYielded = pdFALSE;\r
1028 \r
1029         /* It is possible that an ISR caused a task to be removed from an event\r
1030         list while the scheduler was suspended.  If this was the case then the\r
1031         removed task will have been added to the xPendingReadyList.  Once the\r
1032         scheduler has been resumed it is safe to move all the pending ready\r
1033         tasks from this list into their appropriate ready list. */\r
1034         portENTER_CRITICAL();\r
1035         {\r
1036                 --uxSchedulerSuspended;\r
1037 \r
1038                 if( uxSchedulerSuspended == ( unsigned portBASE_TYPE ) pdFALSE )\r
1039                 {                       \r
1040                         if( uxCurrentNumberOfTasks > ( unsigned portBASE_TYPE ) 0 )\r
1041                         {\r
1042                                 portBASE_TYPE xYieldRequired = pdFALSE;\r
1043                                 \r
1044                                 /* Move any readied tasks from the pending list into the\r
1045                                 appropriate ready list. */\r
1046                                 while( ( pxTCB = ( tskTCB * ) listGET_OWNER_OF_HEAD_ENTRY(  ( ( xList * ) &xPendingReadyList ) ) ) != NULL )\r
1047                                 {\r
1048                                         vListRemove( &( pxTCB->xEventListItem ) );\r
1049                                         vListRemove( &( pxTCB->xGenericListItem ) );\r
1050                                         prvAddTaskToReadyQueue( pxTCB );\r
1051                                         \r
1052                                         /* If we have moved a task that has a priority higher than\r
1053                                         the current task then we should yield. */\r
1054                                         if( pxTCB->uxPriority >= pxCurrentTCB->uxPriority )\r
1055                                         {\r
1056                                                 xYieldRequired = pdTRUE;\r
1057                                         }\r
1058                                 }\r
1059 \r
1060                                 /* If any ticks occurred while the scheduler was suspended then\r
1061                                 they should be processed now.  This ensures the tick count does not\r
1062                                 slip, and that any delayed tasks are resumed at the correct time. */\r
1063                                 if( uxMissedTicks > ( unsigned portBASE_TYPE ) 0 )\r
1064                                 {\r
1065                                         while( uxMissedTicks > ( unsigned portBASE_TYPE ) 0 )\r
1066                                         {\r
1067                                                 vTaskIncrementTick();\r
1068                                                 --uxMissedTicks;\r
1069                                         }\r
1070 \r
1071                                         /* As we have processed some ticks it is appropriate to yield\r
1072                                         to ensure the highest priority task that is ready to run is\r
1073                                         the task actually running. */\r
1074                                         #if configUSE_PREEMPTION == 1\r
1075                                         {\r
1076                                                 xYieldRequired = pdTRUE;\r
1077                                         }\r
1078                                         #endif\r
1079                                 }\r
1080                                 \r
1081                                 if( ( xYieldRequired == pdTRUE ) || ( xMissedYield == pdTRUE ) )\r
1082                                 {\r
1083                                         xAlreadyYielded = pdTRUE;\r
1084                                         xMissedYield = pdFALSE;\r
1085                                         taskYIELD();\r
1086                                 }\r
1087                         }\r
1088                 }\r
1089         }\r
1090         portEXIT_CRITICAL();\r
1091 \r
1092         return xAlreadyYielded;\r
1093 }\r
1094 \r
1095 \r
1096 \r
1097 \r
1098 \r
1099 \r
1100 /*-----------------------------------------------------------\r
1101  * PUBLIC TASK UTILITIES documented in task.h\r
1102  *----------------------------------------------------------*/\r
1103 \r
1104 \r
1105 \r
1106 portTickType xTaskGetTickCount( void )\r
1107 {\r
1108 portTickType xTicks;\r
1109 \r
1110         /* Critical section required if running on a 16 bit processor. */\r
1111         taskENTER_CRITICAL();\r
1112         {\r
1113                 xTicks = xTickCount;\r
1114         }\r
1115         taskEXIT_CRITICAL();\r
1116 \r
1117         return xTicks;\r
1118 }\r
1119 /*-----------------------------------------------------------*/\r
1120 \r
1121 unsigned portBASE_TYPE uxTaskGetNumberOfTasks( void )\r
1122 {\r
1123         /* A critical section is not required because the variables are of type\r
1124         portBASE_TYPE. */\r
1125         return uxCurrentNumberOfTasks;\r
1126 }\r
1127 /*-----------------------------------------------------------*/\r
1128 \r
1129 #if ( ( configUSE_TRACE_FACILITY == 1 ) && ( INCLUDE_vTaskDelete == 1 ) && ( INCLUDE_vTaskSuspend == 1 ) )\r
1130 \r
1131         void vTaskList( signed portCHAR *pcWriteBuffer )\r
1132         {\r
1133         unsigned portBASE_TYPE uxQueue;\r
1134 \r
1135                 /* This is a VERY costly function that should be used for debug only.\r
1136                 It leaves interrupts disabled for a LONG time. */\r
1137 \r
1138         vTaskSuspendAll();\r
1139                 {\r
1140                         /* Run through all the lists that could potentially contain a TCB and\r
1141                         report the task name, state and stack high water mark. */\r
1142 \r
1143                         pcWriteBuffer[ 0 ] = ( signed portCHAR ) 0x00;\r
1144                         strcat( ( portCHAR * ) pcWriteBuffer, ( const portCHAR * ) "\r\n" );\r
1145 \r
1146                         uxQueue = uxTopUsedPriority + 1;\r
1147 \r
1148                         do\r
1149                         {\r
1150                                 uxQueue--;\r
1151 \r
1152                                 if( !listLIST_IS_EMPTY( &( pxReadyTasksLists[ uxQueue ] ) ) )\r
1153                                 {\r
1154                                         prvListTaskWithinSingleList( pcWriteBuffer, ( xList * ) &( pxReadyTasksLists[ uxQueue ] ), tskREADY_CHAR );                     \r
1155                                 }\r
1156                         }while( uxQueue > ( unsigned portSHORT ) tskIDLE_PRIORITY );\r
1157 \r
1158                         if( !listLIST_IS_EMPTY( pxDelayedTaskList ) )\r
1159                         {\r
1160                                 prvListTaskWithinSingleList( pcWriteBuffer, ( xList * ) pxDelayedTaskList, tskBLOCKED_CHAR );\r
1161                         }\r
1162 \r
1163                         if( !listLIST_IS_EMPTY( pxOverflowDelayedTaskList ) )\r
1164                         {\r
1165                                 prvListTaskWithinSingleList( pcWriteBuffer, ( xList * ) pxOverflowDelayedTaskList, tskBLOCKED_CHAR );\r
1166                         }\r
1167 \r
1168                         if( !listLIST_IS_EMPTY( &xTasksWaitingTermination ) )\r
1169                         {\r
1170                                 prvListTaskWithinSingleList( pcWriteBuffer, ( xList * ) &xTasksWaitingTermination, tskDELETED_CHAR );\r
1171                         }\r
1172 \r
1173                         if( !listLIST_IS_EMPTY( &xSuspendedTaskList ) )\r
1174                         {\r
1175                                 prvListTaskWithinSingleList( pcWriteBuffer, ( xList * ) &xSuspendedTaskList, tskSUSPENDED_CHAR );\r
1176                         }\r
1177                 }\r
1178         xTaskResumeAll();\r
1179         }\r
1180 \r
1181 #endif\r
1182 /*----------------------------------------------------------*/\r
1183 \r
1184 #if ( configUSE_TRACE_FACILITY == 1 )\r
1185 \r
1186         void vTaskStartTrace( signed portCHAR * pcBuffer, unsigned portLONG ulBufferSize )\r
1187         {\r
1188                 portENTER_CRITICAL();\r
1189                 {\r
1190                         pcTraceBuffer = ( signed portCHAR * )pcBuffer;\r
1191                         pcTraceBufferStart = pcBuffer;\r
1192                         pcTraceBufferEnd = pcBuffer + ( ulBufferSize - tskSIZE_OF_EACH_TRACE_LINE );\r
1193                         xTracing = pdTRUE;\r
1194                 }\r
1195                 portEXIT_CRITICAL();\r
1196         }\r
1197 \r
1198 #endif\r
1199 /*----------------------------------------------------------*/\r
1200 \r
1201 #if ( configUSE_TRACE_FACILITY == 1 )\r
1202 \r
1203         unsigned portLONG ulTaskEndTrace( void )\r
1204         {\r
1205         unsigned portLONG ulBufferLength;\r
1206 \r
1207                 portENTER_CRITICAL();\r
1208                         xTracing = pdFALSE;\r
1209                 portEXIT_CRITICAL();\r
1210 \r
1211                 ulBufferLength = ( unsigned portLONG ) ( pcTraceBuffer - pcTraceBufferStart );\r
1212 \r
1213                 return ulBufferLength;\r
1214         }\r
1215 \r
1216 #endif\r
1217 \r
1218 \r
1219 \r
1220 /*-----------------------------------------------------------\r
1221  * SCHEDULER INTERNALS AVAILABLE FOR PORTING PURPOSES\r
1222  * documented in task.h\r
1223  *----------------------------------------------------------*/\r
1224 \r
1225 \r
1226 void vTaskIncrementTick( void )\r
1227 {\r
1228         /* Called by the portable layer each time a tick interrupt occurs.\r
1229         Increments the tick then checks to see if the new tick value will cause any\r
1230         tasks to be unblocked. */\r
1231         if( uxSchedulerSuspended == ( unsigned portBASE_TYPE ) pdFALSE )\r
1232         {\r
1233                 ++xTickCount;\r
1234                 if( xTickCount == ( portTickType ) 0 )\r
1235                 {\r
1236                         xList *pxTemp;\r
1237 \r
1238                         /* Tick count has overflowed so we need to swap the delay lists.\r
1239                         If there are any items in pxDelayedTaskList here then there is\r
1240                         an error! */\r
1241                         pxTemp = pxDelayedTaskList;\r
1242                         pxDelayedTaskList = pxOverflowDelayedTaskList;\r
1243                         pxOverflowDelayedTaskList = pxTemp;\r
1244             xNumOfOverflows++;\r
1245                 }\r
1246 \r
1247                 /* See if this tick has made a timeout expire. */\r
1248                 prvCheckDelayedTasks();\r
1249         }\r
1250         else\r
1251         {\r
1252                 ++uxMissedTicks;\r
1253 \r
1254                 /* The tick hook gets called at regular intervals, even if the\r
1255                 scheduler is locked. */\r
1256                 #if ( configUSE_TICK_HOOK == 1 )\r
1257                 {\r
1258                         extern void vApplicationTickHook( void );\r
1259 \r
1260                         vApplicationTickHook();\r
1261                 }\r
1262                 #endif\r
1263         }\r
1264 \r
1265         #if ( configUSE_TICK_HOOK == 1 )\r
1266         {\r
1267                 extern void vApplicationTickHook( void );\r
1268 \r
1269                 /* Guard against the tick hook being called when the missed tick\r
1270                 count is being unwound (when the scheduler is being unlocked. */\r
1271                 if( uxMissedTicks == 0 )\r
1272                 {\r
1273                         vApplicationTickHook();\r
1274                 }\r
1275         }\r
1276         #endif\r
1277 \r
1278         traceTASK_INCREMENT_TICK( xTickCount );\r
1279 }\r
1280 /*-----------------------------------------------------------*/\r
1281 \r
1282 #if ( ( INCLUDE_vTaskCleanUpResources == 1 ) && ( INCLUDE_vTaskSuspend == 1 ) )\r
1283 \r
1284         void vTaskCleanUpResources( void )\r
1285         {\r
1286         unsigned portSHORT usQueue;\r
1287         volatile tskTCB *pxTCB;\r
1288 \r
1289                 usQueue = ( unsigned portSHORT ) uxTopUsedPriority + ( unsigned portSHORT ) 1;\r
1290 \r
1291                 /* Remove any TCB's from the ready queues. */\r
1292                 do\r
1293                 {\r
1294                         usQueue--;\r
1295 \r
1296                         while( !listLIST_IS_EMPTY( &( pxReadyTasksLists[ usQueue ] ) ) )\r
1297                         {\r
1298                                 listGET_OWNER_OF_NEXT_ENTRY( pxTCB, &( pxReadyTasksLists[ usQueue ] ) );\r
1299                                 vListRemove( ( xListItem * ) &( pxTCB->xGenericListItem ) );\r
1300 \r
1301                                 prvDeleteTCB( ( tskTCB * ) pxTCB );\r
1302                         }\r
1303                 }while( usQueue > ( unsigned portSHORT ) tskIDLE_PRIORITY );\r
1304 \r
1305                 /* Remove any TCB's from the delayed queue. */\r
1306                 while( !listLIST_IS_EMPTY( &xDelayedTaskList1 ) )\r
1307                 {\r
1308                         listGET_OWNER_OF_NEXT_ENTRY( pxTCB, &xDelayedTaskList1 );\r
1309                         vListRemove( ( xListItem * ) &( pxTCB->xGenericListItem ) );\r
1310 \r
1311                         prvDeleteTCB( ( tskTCB * ) pxTCB );\r
1312                 }\r
1313 \r
1314                 /* Remove any TCB's from the overflow delayed queue. */\r
1315                 while( !listLIST_IS_EMPTY( &xDelayedTaskList2 ) )\r
1316                 {\r
1317                         listGET_OWNER_OF_NEXT_ENTRY( pxTCB, &xDelayedTaskList2 );\r
1318                         vListRemove( ( xListItem * ) &( pxTCB->xGenericListItem ) );\r
1319 \r
1320                         prvDeleteTCB( ( tskTCB * ) pxTCB );\r
1321                 }\r
1322 \r
1323                 while( !listLIST_IS_EMPTY( &xSuspendedTaskList ) )\r
1324                 {\r
1325                         listGET_OWNER_OF_NEXT_ENTRY( pxTCB, &xSuspendedTaskList );\r
1326                         vListRemove( ( xListItem * ) &( pxTCB->xGenericListItem ) );\r
1327 \r
1328                         prvDeleteTCB( ( tskTCB * ) pxTCB );\r
1329                 }               \r
1330         }\r
1331 \r
1332 #endif\r
1333 /*-----------------------------------------------------------*/\r
1334 \r
1335 #if ( configUSE_APPLICATION_TASK_TAG == 1 )\r
1336 \r
1337         void vTaskSetApplicationTaskTag( xTaskHandle xTask, pdTASK_HOOK_CODE pxTagValue )\r
1338         {\r
1339         tskTCB *xTCB;\r
1340 \r
1341                 /* If xTask is NULL then we are setting our own task hook. */\r
1342                 if( xTask == NULL )\r
1343                 {\r
1344                         xTCB = ( tskTCB * ) pxCurrentTCB;\r
1345                 }\r
1346                 else\r
1347                 {\r
1348                         xTCB = ( tskTCB * ) xTask;\r
1349                 }\r
1350                 \r
1351                 /* Save the hook function in the TCB.  A critical section is required as\r
1352                 the value can be accessed from an interrupt. */\r
1353                 portENTER_CRITICAL();\r
1354                         xTCB->pxTaskTag = pxTagValue;\r
1355                 portEXIT_CRITICAL();\r
1356         }\r
1357         \r
1358 #endif\r
1359 /*-----------------------------------------------------------*/\r
1360 \r
1361 #if ( configUSE_APPLICATION_TASK_TAG == 1 )\r
1362 \r
1363         portBASE_TYPE xTaskCallApplicationTaskHook( xTaskHandle xTask, void *pvParameter )\r
1364         {\r
1365         tskTCB *xTCB;\r
1366         portBASE_TYPE xReturn;\r
1367 \r
1368                 /* If xTask is NULL then we are calling our own task hook. */\r
1369                 if( xTask == NULL )\r
1370                 {\r
1371                         xTCB = ( tskTCB * ) pxCurrentTCB;\r
1372                 }\r
1373                 else\r
1374                 {\r
1375                         xTCB = ( tskTCB * ) xTask;\r
1376                 }\r
1377 \r
1378                 if( xTCB->pxTaskTag != NULL )\r
1379                 {\r
1380                         xReturn = xTCB->pxTaskTag( pvParameter );\r
1381                 }\r
1382                 else\r
1383                 {\r
1384                         xReturn = pdFAIL;\r
1385                 }\r
1386 \r
1387                 return xReturn;\r
1388         }\r
1389         \r
1390 #endif\r
1391 /*-----------------------------------------------------------*/\r
1392 \r
1393 void vTaskSwitchContext( void )\r
1394 {\r
1395         traceTASK_SWITCHED_OUT();\r
1396 \r
1397         if( uxSchedulerSuspended != ( unsigned portBASE_TYPE ) pdFALSE )\r
1398         {\r
1399                 /* The scheduler is currently suspended - do not allow a context\r
1400                 switch. */\r
1401                 xMissedYield = pdTRUE;\r
1402                 return;\r
1403         }\r
1404 \r
1405         taskFIRST_CHECK_FOR_STACK_OVERFLOW();\r
1406         taskSECOND_CHECK_FOR_STACK_OVERFLOW();\r
1407 \r
1408         /* Find the highest priority queue that contains ready tasks. */\r
1409         while( listLIST_IS_EMPTY( &( pxReadyTasksLists[ uxTopReadyPriority ] ) ) )\r
1410         {\r
1411                 --uxTopReadyPriority;\r
1412         }\r
1413 \r
1414         /* listGET_OWNER_OF_NEXT_ENTRY walks through the list, so the tasks of the\r
1415         same priority get an equal share of the processor time. */\r
1416         listGET_OWNER_OF_NEXT_ENTRY( pxCurrentTCB, &( pxReadyTasksLists[ uxTopReadyPriority ] ) );\r
1417 \r
1418         traceTASK_SWITCHED_IN();\r
1419         vWriteTraceToBuffer();\r
1420 }\r
1421 /*-----------------------------------------------------------*/\r
1422 \r
1423 void vTaskPlaceOnEventList( const xList * const pxEventList, portTickType xTicksToWait )\r
1424 {\r
1425 portTickType xTimeToWake;\r
1426 \r
1427         /* THIS FUNCTION MUST BE CALLED WITH INTERRUPTS DISABLED OR THE\r
1428         SCHEDULER SUSPENDED. */\r
1429 \r
1430         /* Place the event list item of the TCB in the appropriate event list.\r
1431         This is placed in the list in priority order so the highest priority task\r
1432         is the first to be woken by the event. */\r
1433         vListInsert( ( xList * ) pxEventList, ( xListItem * ) &( pxCurrentTCB->xEventListItem ) );\r
1434 \r
1435         /* We must remove ourselves from the ready list before adding ourselves\r
1436         to the blocked list as the same list item is used for both lists.  We have\r
1437         exclusive access to the ready lists as the scheduler is locked. */\r
1438         vListRemove( ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );\r
1439 \r
1440 \r
1441         #if ( INCLUDE_vTaskSuspend == 1 )\r
1442         {                       \r
1443                 if( xTicksToWait == portMAX_DELAY )\r
1444                 {\r
1445                         /* Add ourselves to the suspended task list instead of a delayed task\r
1446                         list to ensure we are not woken by a timing event.  We will block\r
1447                         indefinitely. */\r
1448                         vListInsertEnd( ( xList * ) &xSuspendedTaskList, ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );\r
1449                 }\r
1450                 else\r
1451                 {\r
1452                         /* Calculate the time at which the task should be woken if the event does\r
1453                         not occur.  This may overflow but this doesn't matter. */\r
1454                         xTimeToWake = xTickCount + xTicksToWait;\r
1455                 \r
1456                         listSET_LIST_ITEM_VALUE( &( pxCurrentTCB->xGenericListItem ), xTimeToWake );\r
1457                 \r
1458                         if( xTimeToWake < xTickCount )\r
1459                         {\r
1460                                 /* Wake time has overflowed.  Place this item in the overflow list. */\r
1461                                 vListInsert( ( xList * ) pxOverflowDelayedTaskList, ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );\r
1462                         }\r
1463                         else\r
1464                         {\r
1465                                 /* The wake time has not overflowed, so we can use the current block list. */\r
1466                                 vListInsert( ( xList * ) pxDelayedTaskList, ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );\r
1467                         }\r
1468                 }\r
1469         }\r
1470         #else\r
1471         {\r
1472                         /* Calculate the time at which the task should be woken if the event does\r
1473                         not occur.  This may overflow but this doesn't matter. */\r
1474                         xTimeToWake = xTickCount + xTicksToWait;\r
1475                 \r
1476                         listSET_LIST_ITEM_VALUE( &( pxCurrentTCB->xGenericListItem ), xTimeToWake );\r
1477                 \r
1478                         if( xTimeToWake < xTickCount )\r
1479                         {\r
1480                                 /* Wake time has overflowed.  Place this item in the overflow list. */\r
1481                                 vListInsert( ( xList * ) pxOverflowDelayedTaskList, ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );\r
1482                         }\r
1483                         else\r
1484                         {\r
1485                                 /* The wake time has not overflowed, so we can use the current block list. */\r
1486                                 vListInsert( ( xList * ) pxDelayedTaskList, ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );\r
1487                         }\r
1488         }\r
1489         #endif\r
1490 }\r
1491 /*-----------------------------------------------------------*/\r
1492 \r
1493 signed portBASE_TYPE xTaskRemoveFromEventList( const xList * const pxEventList )\r
1494 {\r
1495 tskTCB *pxUnblockedTCB;\r
1496 portBASE_TYPE xReturn;\r
1497 \r
1498         /* THIS FUNCTION MUST BE CALLED WITH INTERRUPTS DISABLED OR THE\r
1499         SCHEDULER SUSPENDED.  It can also be called from within an ISR. */\r
1500 \r
1501         /* The event list is sorted in priority order, so we can remove the\r
1502         first in the list, remove the TCB from the delayed list, and add\r
1503         it to the ready list.\r
1504         \r
1505         If an event is for a queue that is locked then this function will never\r
1506         get called - the lock count on the queue will get modified instead.  This\r
1507         means we can always expect exclusive access to the event list here. */\r
1508         pxUnblockedTCB = ( tskTCB * ) listGET_OWNER_OF_HEAD_ENTRY( pxEventList );\r
1509         vListRemove( &( pxUnblockedTCB->xEventListItem ) );\r
1510 \r
1511         if( uxSchedulerSuspended == ( unsigned portBASE_TYPE ) pdFALSE )\r
1512         {\r
1513                 vListRemove( &( pxUnblockedTCB->xGenericListItem ) );\r
1514                 prvAddTaskToReadyQueue( pxUnblockedTCB );\r
1515         }\r
1516         else\r
1517         {\r
1518                 /* We cannot access the delayed or ready lists, so will hold this\r
1519                 task pending until the scheduler is resumed. */\r
1520                 vListInsertEnd( ( xList * ) &( xPendingReadyList ), &( pxUnblockedTCB->xEventListItem ) );\r
1521         }\r
1522 \r
1523         if( pxUnblockedTCB->uxPriority >= pxCurrentTCB->uxPriority )\r
1524         {\r
1525                 /* Return true if the task removed from the event list has\r
1526                 a higher priority than the calling task.  This allows\r
1527                 the calling task to know if it should force a context\r
1528                 switch now. */\r
1529                 xReturn = pdTRUE;\r
1530         }\r
1531         else\r
1532         {\r
1533                 xReturn = pdFALSE;\r
1534         }\r
1535 \r
1536         return xReturn;\r
1537 }\r
1538 /*-----------------------------------------------------------*/\r
1539 \r
1540 void vTaskSetTimeOutState( xTimeOutType * const pxTimeOut )\r
1541 {\r
1542     pxTimeOut->xOverflowCount = xNumOfOverflows;\r
1543     pxTimeOut->xTimeOnEntering = xTickCount;\r
1544 }\r
1545 /*-----------------------------------------------------------*/\r
1546 \r
1547 portBASE_TYPE xTaskCheckForTimeOut( xTimeOutType * const pxTimeOut, portTickType * const pxTicksToWait )\r
1548 {\r
1549 portBASE_TYPE xReturn;\r
1550 \r
1551         portENTER_CRITICAL();\r
1552         {\r
1553                 #if ( INCLUDE_vTaskSuspend == 1 )\r
1554                         /* If INCLUDE_vTaskSuspend is set to 1 and the block time specified is\r
1555                         the maximum block time then the task should block indefinitely, and\r
1556                         therefore never time out. */\r
1557                         if( *pxTicksToWait == portMAX_DELAY )\r
1558                         {\r
1559                                 xReturn = pdFALSE;\r
1560                         }\r
1561                         else /* We are not blocking indefinitely, perform the checks below. */\r
1562                 #endif\r
1563 \r
1564                 if( ( xNumOfOverflows != pxTimeOut->xOverflowCount ) && ( xTickCount >= pxTimeOut->xTimeOnEntering ) )\r
1565                 {\r
1566                         /* The tick count is greater than the time at which vTaskSetTimeout()\r
1567                         was called, but has also overflowed since vTaskSetTimeOut() was called.\r
1568                         It must have wrapped all the way around and gone past us again. This\r
1569                         passed since vTaskSetTimeout() was called. */\r
1570                         xReturn = pdTRUE;\r
1571                 }\r
1572                 else if( ( xTickCount - pxTimeOut->xTimeOnEntering ) < *pxTicksToWait )\r
1573                 {\r
1574                         /* Not a genuine timeout. Adjust parameters for time remaining. */\r
1575                         *pxTicksToWait -= ( xTickCount - pxTimeOut->xTimeOnEntering );\r
1576                         vTaskSetTimeOutState( pxTimeOut );\r
1577                         xReturn = pdFALSE;\r
1578                 }\r
1579                 else\r
1580                 {\r
1581                         xReturn = pdTRUE;\r
1582                 }\r
1583         }\r
1584         portEXIT_CRITICAL();\r
1585 \r
1586     return xReturn;\r
1587 }\r
1588 /*-----------------------------------------------------------*/\r
1589 \r
1590 void vTaskMissedYield( void )\r
1591 {\r
1592         xMissedYield = pdTRUE;\r
1593 }\r
1594 \r
1595 /*\r
1596  * -----------------------------------------------------------\r
1597  * The Idle task.\r
1598  * ----------------------------------------------------------\r
1599  *\r
1600  * The portTASK_FUNCTION() macro is used to allow port/compiler specific\r
1601  * language extensions.  The equivalent prototype for this function is:\r
1602  *\r
1603  * void prvIdleTask( void *pvParameters );\r
1604  *\r
1605  */\r
1606 static portTASK_FUNCTION( prvIdleTask, pvParameters )\r
1607 {\r
1608         /* Stop warnings. */\r
1609         ( void ) pvParameters;\r
1610 \r
1611         for( ;; )\r
1612         {\r
1613                 /* See if any tasks have been deleted. */\r
1614                 prvCheckTasksWaitingTermination();\r
1615 \r
1616                 #if ( configUSE_PREEMPTION == 0 )\r
1617                 {\r
1618                         /* If we are not using preemption we keep forcing a task switch to\r
1619                         see if any other task has become available.  If we are using\r
1620                         preemption we don't need to do this as any task becoming available\r
1621                         will automatically get the processor anyway. */\r
1622                         taskYIELD();    \r
1623                 }\r
1624                 #endif\r
1625 \r
1626                 #if ( ( configUSE_PREEMPTION == 1 ) && ( configIDLE_SHOULD_YIELD == 1 ) )\r
1627                 {\r
1628                         /* When using preemption tasks of equal priority will be\r
1629                         timesliced.  If a task that is sharing the idle priority is ready\r
1630                         to run then the idle task should yield before the end of the\r
1631                         timeslice.\r
1632                         \r
1633                         A critical region is not required here as we are just reading from\r
1634                         the list, and an occasional incorrect value will not matter.  If\r
1635                         the ready list at the idle priority contains more than one task\r
1636                         then a task other than the idle task is ready to execute. */\r
1637                         if( listCURRENT_LIST_LENGTH( &( pxReadyTasksLists[ tskIDLE_PRIORITY ] ) ) > ( unsigned portBASE_TYPE ) 1 )\r
1638                         {\r
1639                                 taskYIELD();\r
1640                         }\r
1641                 }\r
1642                 #endif\r
1643 \r
1644                 #if ( configUSE_IDLE_HOOK == 1 )\r
1645                 {\r
1646                         extern void vApplicationIdleHook( void );\r
1647 \r
1648                         /* Call the user defined function from within the idle task.  This\r
1649                         allows the application designer to add background functionality\r
1650                         without the overhead of a separate task.\r
1651                         NOTE: vApplicationIdleHook() MUST NOT, UNDER ANY CIRCUMSTANCES,\r
1652                         CALL A FUNCTION THAT MIGHT BLOCK. */\r
1653                         vApplicationIdleHook();\r
1654                 }\r
1655                 #endif\r
1656         }\r
1657 } /*lint !e715 pvParameters is not accessed but all task functions require the same prototype. */\r
1658 \r
1659 \r
1660 \r
1661 \r
1662 \r
1663 \r
1664 \r
1665 /*-----------------------------------------------------------\r
1666  * File private functions documented at the top of the file.\r
1667  *----------------------------------------------------------*/\r
1668 \r
1669 \r
1670 \r
1671 static void prvInitialiseTCBVariables( tskTCB *pxTCB, const signed portCHAR * const pcName, unsigned portBASE_TYPE uxPriority )\r
1672 {\r
1673         /* Store the function name in the TCB. */\r
1674         strncpy( ( char * ) pxTCB->pcTaskName, ( const char * ) pcName, ( unsigned portSHORT ) configMAX_TASK_NAME_LEN );\r
1675         pxTCB->pcTaskName[ ( unsigned portSHORT ) configMAX_TASK_NAME_LEN - ( unsigned portSHORT ) 1 ] = '\0';\r
1676 \r
1677         /* This is used as an array index so must ensure it's not too large. */\r
1678         if( uxPriority >= configMAX_PRIORITIES )\r
1679         {\r
1680                 uxPriority = configMAX_PRIORITIES - 1;\r
1681         }\r
1682 \r
1683         pxTCB->uxPriority = uxPriority;\r
1684         #if ( configUSE_MUTEXES == 1 )\r
1685         {\r
1686                 pxTCB->uxBasePriority = uxPriority;\r
1687         }\r
1688         #endif\r
1689 \r
1690         vListInitialiseItem( &( pxTCB->xGenericListItem ) );\r
1691         vListInitialiseItem( &( pxTCB->xEventListItem ) );\r
1692 \r
1693         /* Set the pxTCB as a link back from the xListItem.  This is so we can get\r
1694         back to the containing TCB from a generic item in a list. */\r
1695         listSET_LIST_ITEM_OWNER( &( pxTCB->xGenericListItem ), pxTCB );\r
1696 \r
1697         /* Event lists are always in priority order. */\r
1698         listSET_LIST_ITEM_VALUE( &( pxTCB->xEventListItem ), configMAX_PRIORITIES - ( portTickType ) uxPriority );\r
1699         listSET_LIST_ITEM_OWNER( &( pxTCB->xEventListItem ), pxTCB );\r
1700 \r
1701         #if ( portCRITICAL_NESTING_IN_TCB == 1 )\r
1702         {\r
1703                 pxTCB->uxCriticalNesting = ( unsigned portBASE_TYPE ) 0;\r
1704         }\r
1705         #endif\r
1706 \r
1707         #if ( configUSE_APPLICATION_TASK_TAG == 1 )\r
1708         {\r
1709                 pxTCB->pxTaskTag = NULL;\r
1710         }\r
1711         #endif  \r
1712 }\r
1713 /*-----------------------------------------------------------*/\r
1714 \r
1715 static void prvInitialiseTaskLists( void )\r
1716 {\r
1717 unsigned portBASE_TYPE uxPriority;\r
1718 \r
1719         for( uxPriority = 0; uxPriority < configMAX_PRIORITIES; uxPriority++ )\r
1720         {\r
1721                 vListInitialise( ( xList * ) &( pxReadyTasksLists[ uxPriority ] ) );\r
1722         }\r
1723 \r
1724         vListInitialise( ( xList * ) &xDelayedTaskList1 );\r
1725         vListInitialise( ( xList * ) &xDelayedTaskList2 );\r
1726         vListInitialise( ( xList * ) &xPendingReadyList );\r
1727 \r
1728         #if ( INCLUDE_vTaskDelete == 1 )\r
1729         {\r
1730                 vListInitialise( ( xList * ) &xTasksWaitingTermination );\r
1731         }\r
1732         #endif\r
1733 \r
1734         #if ( INCLUDE_vTaskSuspend == 1 )\r
1735         {\r
1736                 vListInitialise( ( xList * ) &xSuspendedTaskList );\r
1737         }\r
1738         #endif\r
1739 \r
1740         /* Start with pxDelayedTaskList using list1 and the pxOverflowDelayedTaskList\r
1741         using list2. */\r
1742         pxDelayedTaskList = &xDelayedTaskList1;\r
1743         pxOverflowDelayedTaskList = &xDelayedTaskList2;\r
1744 }\r
1745 /*-----------------------------------------------------------*/\r
1746 \r
1747 static void prvCheckTasksWaitingTermination( void )\r
1748 {                                                       \r
1749         #if ( INCLUDE_vTaskDelete == 1 )\r
1750         {                               \r
1751                 portBASE_TYPE xListIsEmpty;\r
1752 \r
1753                 /* ucTasksDeleted is used to prevent vTaskSuspendAll() being called\r
1754                 too often in the idle task. */\r
1755                 if( uxTasksDeleted > ( unsigned portBASE_TYPE ) 0 )\r
1756                 {\r
1757                         vTaskSuspendAll();\r
1758                                 xListIsEmpty = listLIST_IS_EMPTY( &xTasksWaitingTermination );                          \r
1759                         xTaskResumeAll();\r
1760 \r
1761                         if( !xListIsEmpty )\r
1762                         {\r
1763                                 tskTCB *pxTCB;\r
1764 \r
1765                                 portENTER_CRITICAL();\r
1766                                 {                       \r
1767                                         pxTCB = ( tskTCB * ) listGET_OWNER_OF_HEAD_ENTRY( ( ( xList * ) &xTasksWaitingTermination ) );\r
1768                                         vListRemove( &( pxTCB->xGenericListItem ) );\r
1769                                         --uxCurrentNumberOfTasks;\r
1770                                         --uxTasksDeleted;\r
1771                                 }\r
1772                                 portEXIT_CRITICAL();\r
1773 \r
1774                                 prvDeleteTCB( pxTCB );\r
1775                         }\r
1776                 }\r
1777         }\r
1778         #endif\r
1779 }\r
1780 /*-----------------------------------------------------------*/\r
1781 \r
1782 static tskTCB *prvAllocateTCBAndStack( unsigned portSHORT usStackDepth )\r
1783 {\r
1784 tskTCB *pxNewTCB;\r
1785 \r
1786         /* Allocate space for the TCB.  Where the memory comes from depends on\r
1787         the implementation of the port malloc function. */\r
1788         pxNewTCB = ( tskTCB * ) pvPortMalloc( sizeof( tskTCB ) );\r
1789 \r
1790         if( pxNewTCB != NULL )\r
1791         {\r
1792                 /* Allocate space for the stack used by the task being created.\r
1793                 The base of the stack memory stored in the TCB so the task can\r
1794                 be deleted later if required. */\r
1795                 pxNewTCB->pxStack = ( portSTACK_TYPE * ) pvPortMalloc( ( ( size_t )usStackDepth ) * sizeof( portSTACK_TYPE ) );\r
1796 \r
1797                 if( pxNewTCB->pxStack == NULL )\r
1798                 {\r
1799                         /* Could not allocate the stack.  Delete the allocated TCB. */\r
1800                         vPortFree( pxNewTCB );                  \r
1801                         pxNewTCB = NULL;                        \r
1802                 }               \r
1803                 else\r
1804                 {\r
1805                         /* Just to help debugging. */\r
1806                         memset( pxNewTCB->pxStack, tskSTACK_FILL_BYTE, usStackDepth * sizeof( portSTACK_TYPE ) );\r
1807                 }\r
1808         }\r
1809 \r
1810         return pxNewTCB;\r
1811 }\r
1812 /*-----------------------------------------------------------*/\r
1813 \r
1814 #if ( configUSE_TRACE_FACILITY == 1 )\r
1815 \r
1816         static void prvListTaskWithinSingleList( const signed portCHAR *pcWriteBuffer, xList *pxList, signed portCHAR cStatus )\r
1817         {\r
1818         volatile tskTCB *pxNextTCB, *pxFirstTCB;\r
1819         unsigned portSHORT usStackRemaining;\r
1820 \r
1821                 /* Write the details of all the TCB's in pxList into the buffer. */\r
1822                 listGET_OWNER_OF_NEXT_ENTRY( pxFirstTCB, pxList );\r
1823                 do\r
1824                 {\r
1825                         listGET_OWNER_OF_NEXT_ENTRY( pxNextTCB, pxList );\r
1826                         usStackRemaining = usTaskCheckFreeStackSpace( ( unsigned portCHAR * ) pxNextTCB->pxStack );\r
1827                         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
1828                         strcat( ( portCHAR * ) pcWriteBuffer, ( portCHAR * ) pcStatusString );\r
1829 \r
1830                 } while( pxNextTCB != pxFirstTCB );\r
1831         }\r
1832 \r
1833 #endif\r
1834 /*-----------------------------------------------------------*/\r
1835 \r
1836 #if ( ( configUSE_TRACE_FACILITY == 1 ) || ( INCLUDE_uxTaskGetStackHighWaterMark == 1 ) )\r
1837 \r
1838         unsigned portSHORT usTaskCheckFreeStackSpace( const unsigned portCHAR * pucStackByte )\r
1839         {\r
1840         register unsigned portSHORT usCount = 0;\r
1841 \r
1842                 while( *pucStackByte == tskSTACK_FILL_BYTE )\r
1843                 {\r
1844                         pucStackByte -= portSTACK_GROWTH;\r
1845                         usCount++;\r
1846                 }\r
1847 \r
1848                 usCount /= sizeof( portSTACK_TYPE );\r
1849 \r
1850                 return usCount;\r
1851         }\r
1852 \r
1853 #endif\r
1854 /*-----------------------------------------------------------*/\r
1855 \r
1856 #if ( INCLUDE_uxTaskGetStackHighWaterMark == 1 )\r
1857 \r
1858         unsigned portBASE_TYPE uxTaskGetStackHighWaterMark( xTaskHandle xTask )\r
1859         {\r
1860         tskTCB *pxTCB;\r
1861         unsigned portCHAR *pcEndOfStack;\r
1862 \r
1863                 pxTCB = prvGetTCBFromHandle( xTask );\r
1864 \r
1865                 #if portSTACK_GROWTH < 0\r
1866                 {\r
1867                         pcEndOfStack = ( unsigned portCHAR * ) pxTCB->pxStack;\r
1868                 }\r
1869                 #else\r
1870                 {\r
1871                         pcEndOfStack = ( unsigned portCHAR * ) pxTCB->pxEndOfStack;\r
1872                 }\r
1873                 #endif\r
1874 \r
1875                 return usTaskCheckFreeStackSpace( pcEndOfStack );\r
1876         }\r
1877 \r
1878 #endif\r
1879 /*-----------------------------------------------------------*/\r
1880 \r
1881 #if ( ( INCLUDE_vTaskDelete == 1 ) || ( INCLUDE_vTaskCleanUpResources == 1 ) )\r
1882 \r
1883         static void prvDeleteTCB( tskTCB *pxTCB )\r
1884         {\r
1885                 /* Free up the memory allocated by the scheduler for the task.  It is up to\r
1886                 the task to free any memory allocated at the application level. */\r
1887                 vPortFree( pxTCB->pxStack );\r
1888                 vPortFree( pxTCB );\r
1889         }\r
1890 \r
1891 #endif\r
1892 \r
1893 \r
1894 /*-----------------------------------------------------------*/\r
1895 \r
1896 #if ( INCLUDE_xTaskGetCurrentTaskHandle == 1 )\r
1897 \r
1898         xTaskHandle xTaskGetCurrentTaskHandle( void )\r
1899         {\r
1900                 /* A critical section is not required as this is not called from\r
1901                 an interrupt and the current TCB will always be the same for any\r
1902                 individual execution thread. */\r
1903                 return pxCurrentTCB;\r
1904         }\r
1905 \r
1906 #endif\r
1907 \r
1908 /*-----------------------------------------------------------*/\r
1909 \r
1910 #if ( INCLUDE_xTaskGetSchedulerState == 1 )\r
1911 \r
1912         portBASE_TYPE xTaskGetSchedulerState( void )\r
1913         {\r
1914         portBASE_TYPE xReturn;\r
1915         \r
1916                 if( xSchedulerRunning == pdFALSE )\r
1917                 {\r
1918                         xReturn = taskSCHEDULER_NOT_STARTED;\r
1919                 }\r
1920                 else\r
1921                 {\r
1922                         if( uxSchedulerSuspended == ( unsigned portBASE_TYPE ) pdFALSE )\r
1923                         {\r
1924                                 xReturn = taskSCHEDULER_RUNNING;\r
1925                         }\r
1926                         else\r
1927                         {\r
1928                                 xReturn = taskSCHEDULER_SUSPENDED;\r
1929                         }\r
1930                 }\r
1931                 \r
1932                 return xReturn;\r
1933         }\r
1934 \r
1935 #endif\r
1936 /*-----------------------------------------------------------*/\r
1937 \r
1938 #if ( configUSE_MUTEXES == 1 )\r
1939         \r
1940         void vTaskPriorityInherit( xTaskHandle * const pxMutexHolder )\r
1941         {\r
1942         tskTCB * const pxTCB = ( tskTCB * ) pxMutexHolder;\r
1943 \r
1944                 if( pxTCB->uxPriority < pxCurrentTCB->uxPriority )\r
1945                 {\r
1946                         /* Adjust the mutex holder state to account for its new priority. */\r
1947                         listSET_LIST_ITEM_VALUE( &( pxTCB->xEventListItem ), configMAX_PRIORITIES - ( portTickType ) pxCurrentTCB->uxPriority );\r
1948 \r
1949                         /* If the task being modified is in the ready state it will need to\r
1950                         be moved in to a new list. */\r
1951                         if( listIS_CONTAINED_WITHIN( &( pxReadyTasksLists[ pxTCB->uxPriority ] ), &( pxTCB->xGenericListItem ) ) )\r
1952                         {\r
1953                                 vListRemove( &( pxTCB->xGenericListItem ) );\r
1954 \r
1955                                 /* Inherit the priority before being moved into the new list. */\r
1956                                 pxTCB->uxPriority = pxCurrentTCB->uxPriority;\r
1957                                 prvAddTaskToReadyQueue( pxTCB );\r
1958                         }\r
1959                         else\r
1960                         {\r
1961                                 /* Just inherit the priority. */\r
1962                                 pxTCB->uxPriority = pxCurrentTCB->uxPriority;\r
1963                         }\r
1964                 }\r
1965         }\r
1966 \r
1967 #endif\r
1968 /*-----------------------------------------------------------*/\r
1969 \r
1970 #if ( configUSE_MUTEXES == 1 )  \r
1971 \r
1972         void vTaskPriorityDisinherit( xTaskHandle * const pxMutexHolder )\r
1973         {\r
1974         tskTCB * const pxTCB = ( tskTCB * ) pxMutexHolder;\r
1975 \r
1976                 if( pxMutexHolder != NULL )\r
1977                 {\r
1978                         if( pxTCB->uxPriority != pxTCB->uxBasePriority )\r
1979                         {\r
1980                                 /* We must be the running task to be able to give the mutex back.\r
1981                                 Remove ourselves from the ready list we currently appear in. */\r
1982                                 vListRemove( &( pxTCB->xGenericListItem ) );\r
1983 \r
1984                                 /* Disinherit the priority before adding ourselves into the new\r
1985                                 ready list. */\r
1986                                 pxTCB->uxPriority = pxTCB->uxBasePriority;\r
1987                                 listSET_LIST_ITEM_VALUE( &( pxTCB->xEventListItem ), configMAX_PRIORITIES - ( portTickType ) pxTCB->uxPriority );\r
1988                                 prvAddTaskToReadyQueue( pxTCB );\r
1989                         }\r
1990                 }\r
1991         }\r
1992 \r
1993 #endif\r
1994 /*-----------------------------------------------------------*/\r
1995 \r
1996 #if ( portCRITICAL_NESTING_IN_TCB == 1 )\r
1997 \r
1998         void vTaskEnterCritical( void )\r
1999         {\r
2000                 portDISABLE_INTERRUPTS();\r
2001 \r
2002                 if( xSchedulerRunning != pdFALSE )\r
2003                 {\r
2004                         pxCurrentTCB->uxCriticalNesting++;\r
2005                 }\r
2006         }\r
2007 \r
2008 #endif\r
2009 /*-----------------------------------------------------------*/\r
2010 \r
2011 #if ( portCRITICAL_NESTING_IN_TCB == 1 )\r
2012 \r
2013 void vTaskExitCritical( void )\r
2014 {\r
2015         if( xSchedulerRunning != pdFALSE )\r
2016         {\r
2017                 if( pxCurrentTCB->uxCriticalNesting > 0 )\r
2018                 {\r
2019                         pxCurrentTCB->uxCriticalNesting--;\r
2020 \r
2021                         if( pxCurrentTCB->uxCriticalNesting == 0 )\r
2022                         {\r
2023                                 portENABLE_INTERRUPTS();\r
2024                         }\r
2025                 }\r
2026         }\r
2027 }\r
2028 \r
2029 #endif\r
2030 /*-----------------------------------------------------------*/\r
2031 \r
2032 \r
2033         \r
2034 \r