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

   1 /*\r
   2         FreeRTOS.org V5.1.2 - Copyright (C) 2003-2009 Richard Barry.\r
   3 \r
   4         This file is part of the FreeRTOS.org distribution.\r
   5 \r
   6         FreeRTOS.org is free software; you can redistribute it and/or modify\r
   7         it under the terms of the GNU General Public License as published by\r
   8         the Free Software Foundation; either version 2 of the License, or\r
   9         (at your option) any later version.\r
  10 \r
  11         FreeRTOS.org is distributed in the hope that it will be useful,\r
  12         but WITHOUT ANY WARRANTY; without even the implied warranty of\r
  13         MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the\r
  14         GNU General Public License for more details.\r
  15 \r
  16         You should have received a copy of the GNU General Public License\r
  17         along with FreeRTOS.org; if not, write to the Free Software\r
  18         Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA\r
  19 \r
  20         A special exception to the GPL can be applied should you wish to distribute\r
  21         a combined work that includes FreeRTOS.org, without being obliged to provide\r
  22         the source code for any proprietary components.  See the licensing section\r
  23         of http://www.FreeRTOS.org for full details of how and when the exception\r
  24         can be applied.\r
  25 \r
  26     ***************************************************************************\r
  27     ***************************************************************************\r
  28     *                                                                         *\r
  29     * Get the FreeRTOS eBook!  See http://www.FreeRTOS.org/Documentation      *\r
  30         *                                                                         *\r
  31         * This is a concise, step by step, 'hands on' guide that describes both   *\r
  32         * general multitasking concepts and FreeRTOS specifics. It presents and   *\r
  33         * explains numerous examples that are written using the FreeRTOS API.     *\r
  34         * Full source code for all the examples is provided in an accompanying    *\r
  35         * .zip file.                                                              *\r
  36     *                                                                         *\r
  37     ***************************************************************************\r
  38     ***************************************************************************\r
  39 \r
  40         Please ensure to read the configuration and relevant port sections of the\r
  41         online documentation.\r
  42 \r
  43         http://www.FreeRTOS.org - Documentation, latest information, license and \r
  44         contact details.\r
  45 \r
  46         http://www.SafeRTOS.com - A version that is certified for use in safety \r
  47         critical systems.\r
  48 \r
  49         http://www.OpenRTOS.com - Commercial support, development, porting, \r
  50         licensing and training services.\r
  51 */\r
  52 \r
  53 \r
  54 #include <stdio.h>\r
  55 #include <stdlib.h>\r
  56 #include <string.h>\r
  57 \r
  58 #include "FreeRTOS.h"\r
  59 #include "task.h"\r
  60 #include "StackMacros.h"\r
  61 \r
  62 /*\r
  63  * Macro to define the amount of stack available to the idle task.\r
  64  */\r
  65 #define tskIDLE_STACK_SIZE      configMINIMAL_STACK_SIZE\r
  66 \r
  67 /*\r
  68  * Task control block.  A task control block (TCB) is allocated to each task,\r
  69  * and stores the context of the task.\r
  70  */\r
  71 typedef struct tskTaskControlBlock\r
  72 {\r
  73         volatile portSTACK_TYPE *pxTopOfStack;          /*< Points to the location of the last item placed on the tasks stack.  THIS MUST BE THE FIRST MEMBER OF THE STRUCT. */\r
  74         xListItem                               xGenericListItem;       /*< List item used to place the TCB in ready and blocked queues. */\r
  75         xListItem                               xEventListItem;         /*< List item used to place the TCB in event lists. */\r
  76         unsigned portBASE_TYPE  uxPriority;                     /*< The priority of the task where 0 is the lowest priority. */\r
  77         portSTACK_TYPE                  *pxStack;                       /*< Points to the start of the stack. */\r
  78         signed portCHAR                 pcTaskName[ configMAX_TASK_NAME_LEN ];/*< Descriptive name given to the task when created.  Facilitates debugging only. */\r
  79 \r
  80         #if ( portSTACK_GROWTH > 0 )\r
  81                 portSTACK_TYPE *pxEndOfStack;                   /*< Used for stack overflow checking on architectures where the stack grows up from low memory. */\r
  82         #endif\r
  83 \r
  84         #if ( portCRITICAL_NESTING_IN_TCB == 1 )\r
  85                 unsigned portBASE_TYPE uxCriticalNesting;\r
  86         #endif\r
  87 \r
  88         #if ( configUSE_TRACE_FACILITY == 1 )\r
  89                 unsigned portBASE_TYPE  uxTCBNumber;            /*< This is used for tracing the scheduler and making debugging easier only. */\r
  90         #endif  \r
  91                 \r
  92         #if ( configUSE_MUTEXES == 1 )\r
  93                 unsigned portBASE_TYPE uxBasePriority;\r
  94         #endif\r
  95 \r
  96         #if ( configUSE_APPLICATION_TASK_TAG == 1 )\r
  97                 pdTASK_HOOK_CODE pxTaskTag;\r
  98         #endif\r
  99                 \r
 100 } tskTCB;\r
 101 \r
 102 /*\r
 103  * Some kernel aware debuggers require data to be viewed to be global, rather\r
 104  * than file scope.\r
 105  */\r
 106 #ifdef portREMOVE_STATIC_QUALIFIER\r
 107         #define static\r
 108 #endif\r
 109 \r
 110 /*lint -e956 */\r
 111 \r
 112 tskTCB * volatile pxCurrentTCB = NULL;                                  \r
 113 \r
 114 /* Lists for ready and blocked tasks. --------------------*/\r
 115 \r
 116 static xList pxReadyTasksLists[ configMAX_PRIORITIES ]; /*< Prioritised ready tasks. */\r
 117 static xList xDelayedTaskList1;                                                 /*< Delayed tasks. */\r
 118 static xList xDelayedTaskList2;                                                 /*< Delayed tasks (two lists are used - one for delays that have overflowed the current tick count. */\r
 119 static xList * volatile pxDelayedTaskList;                              /*< Points to the delayed task list currently being used. */\r
 120 static xList * volatile pxOverflowDelayedTaskList;              /*< Points to the delayed task list currently being used to hold tasks that have overflowed the current tick count. */\r
 121 static xList xPendingReadyList;                                                 /*< Tasks that have been readied while the scheduler was suspended.  They will be moved to the ready queue when the scheduler is resumed. */\r
 122 \r
 123 #if ( INCLUDE_vTaskDelete == 1 )\r
 124 \r
 125         static volatile xList xTasksWaitingTermination;         /*< Tasks that have been deleted - but the their memory not yet freed. */\r
 126         static volatile unsigned portBASE_TYPE uxTasksDeleted = ( unsigned portBASE_TYPE ) 0;\r
 127 \r
 128 #endif\r
 129 \r
 130 #if ( INCLUDE_vTaskSuspend == 1 )\r
 131 \r
 132         static xList xSuspendedTaskList;                                        /*< Tasks that are currently suspended. */\r
 133 \r
 134 #endif\r
 135 \r
 136 /* File private variables. --------------------------------*/\r
 137 static volatile unsigned portBASE_TYPE uxCurrentNumberOfTasks   = ( unsigned portBASE_TYPE ) 0;\r
 138 static volatile portTickType xTickCount                                                 = ( portTickType ) 0;\r
 139 static unsigned portBASE_TYPE uxTopUsedPriority                                 = tskIDLE_PRIORITY;\r
 140 static volatile unsigned portBASE_TYPE uxTopReadyPriority               = tskIDLE_PRIORITY;\r
 141 static volatile signed portBASE_TYPE xSchedulerRunning                  = pdFALSE;\r
 142 static volatile unsigned portBASE_TYPE uxSchedulerSuspended             = ( unsigned portBASE_TYPE ) pdFALSE;\r
 143 static volatile unsigned portBASE_TYPE uxMissedTicks                    = ( unsigned portBASE_TYPE ) 0;\r
 144 static volatile portBASE_TYPE xMissedYield                                              = ( portBASE_TYPE ) pdFALSE;\r
 145 static volatile portBASE_TYPE xNumOfOverflows                                   = ( portBASE_TYPE ) 0;\r
 146 #if ( configUSE_TRACE_FACILITY == 1 )\r
 147         static unsigned portBASE_TYPE uxTaskNumber = 0; /*lint !e956 Static is deliberate - this is guarded before use. */\r
 148 #endif\r
 149 \r
 150 /* Debugging and trace facilities private variables and macros. ------------*/\r
 151 \r
 152 /*\r
 153  * The value used to fill the stack of a task when the task is created.  This\r
 154  * is used purely for checking the high water mark for tasks.\r
 155  */\r
 156 #define tskSTACK_FILL_BYTE      ( 0xa5 )\r
 157 \r
 158 /*\r
 159  * Macros used by vListTask to indicate which state a task is in.\r
 160  */\r
 161 #define tskBLOCKED_CHAR         ( ( signed portCHAR ) 'B' )\r
 162 #define tskREADY_CHAR           ( ( signed portCHAR ) 'R' )\r
 163 #define tskDELETED_CHAR         ( ( signed portCHAR ) 'D' )\r
 164 #define tskSUSPENDED_CHAR       ( ( signed portCHAR ) 'S' )\r
 165 \r
 166 /*\r
 167  * Macros and private variables used by the trace facility.\r
 168  */\r
 169 #if ( configUSE_TRACE_FACILITY == 1 )\r
 170 \r
 171         #define tskSIZE_OF_EACH_TRACE_LINE                      ( ( unsigned portLONG ) ( sizeof( unsigned portLONG ) + sizeof( unsigned portLONG ) ) )\r
 172         static volatile signed portCHAR * volatile pcTraceBuffer;\r
 173         static signed portCHAR *pcTraceBufferStart;\r
 174         static signed portCHAR *pcTraceBufferEnd;\r
 175         static signed portBASE_TYPE xTracing = pdFALSE;\r
 176         static unsigned portBASE_TYPE uxPreviousTask = 255;\r
 177         static portCHAR pcStatusString[ 50 ];\r
 178 #endif\r
 179 \r
 180 /*-----------------------------------------------------------*/\r
 181 \r
 182 /*\r
 183  * Macro that writes a trace of scheduler activity to a buffer.  This trace\r
 184  * shows which task is running when and is very useful as a debugging tool.\r
 185  * As this macro is called each context switch it is a good idea to undefine\r
 186  * it if not using the facility.\r
 187  */\r
 188 #if ( configUSE_TRACE_FACILITY == 1 )\r
 189 \r
 190         #define vWriteTraceToBuffer()                                                                                                                                   \\r
 191         {                                                                                                                                                                                               \\r
 192                 if( xTracing )                                                                                                                                                          \\r
 193                 {                                                                                                                                                                                       \\r
 194                         if( uxPreviousTask != pxCurrentTCB->uxTCBNumber )                                                                               \\r
 195                         {                                                                                                                                                                               \\r
 196                                 if( ( pcTraceBuffer + tskSIZE_OF_EACH_TRACE_LINE ) < pcTraceBufferEnd )                         \\r
 197                                 {                                                                                                                                                                       \\r
 198                                         uxPreviousTask = pxCurrentTCB->uxTCBNumber;                                                                             \\r
 199                                         *( unsigned portLONG * ) pcTraceBuffer = ( unsigned portLONG ) xTickCount;              \\r
 200                                         pcTraceBuffer += sizeof( unsigned portLONG );                                                                   \\r
 201                                         *( unsigned portLONG * ) pcTraceBuffer = ( unsigned portLONG ) uxPreviousTask;  \\r
 202                                         pcTraceBuffer += sizeof( unsigned portLONG );                                                                   \\r
 203                                 }                                                                                                                                                                       \\r
 204                                 else                                                                                                                                                            \\r
 205                                 {                                                                                                                                                                       \\r
 206                                         xTracing = pdFALSE;                                                                                                                             \\r
 207                                 }                                                                                                                                                                       \\r
 208                         }                                                                                                                                                                               \\r
 209                 }                                                                                                                                                                                       \\r
 210         }\r
 211 \r
 212 #else\r
 213 \r
 214         #define vWriteTraceToBuffer()\r
 215 \r
 216 #endif\r
 217 /*-----------------------------------------------------------*/\r
 218 \r
 219 /*\r
 220  * Place the task represented by pxTCB into the appropriate ready queue for\r
 221  * the task.  It is inserted at the end of the list.  One quirk of this is\r
 222  * that if the task being inserted is at the same priority as the currently\r
 223  * executing task, then it will only be rescheduled after the currently\r
 224  * executing task has been rescheduled.\r
 225  */\r
 226 #define prvAddTaskToReadyQueue( pxTCB )                                                                                                                                                 \\r
 227 {                                                                                                                                                                                                                               \\r
 228         if( pxTCB->uxPriority > uxTopReadyPriority )                                                                                                                            \\r
 229         {                                                                                                                                                                                                                       \\r
 230                 uxTopReadyPriority = pxTCB->uxPriority;                                                                                                                                 \\r
 231         }                                                                                                                                                                                                                       \\r
 232         vListInsertEnd( ( xList * ) &( pxReadyTasksLists[ pxTCB->uxPriority ] ), &( pxTCB->xGenericListItem ) );        \\r
 233 }\r
 234 /*-----------------------------------------------------------*/         \r
 235 \r
 236 /*\r
 237  * Macro that looks at the list of tasks that are currently delayed to see if\r
 238  * any require waking.\r
 239  *\r
 240  * Tasks are stored in the queue in the order of their wake time - meaning\r
 241  * once one tasks has been found whose timer has not expired we need not look\r
 242  * any further down the list.\r
 243  */\r
 244 #define prvCheckDelayedTasks()                                                                                                                                                                          \\r
 245 {                                                                                                                                                                                                                                       \\r
 246 register tskTCB *pxTCB;                                                                                                                                                                                         \\r
 247                                                                                                                                                                                                                                         \\r
 248         while( ( pxTCB = ( tskTCB * ) listGET_OWNER_OF_HEAD_ENTRY( pxDelayedTaskList ) ) != NULL )                                              \\r
 249         {                                                                                                                                                                                                                               \\r
 250                 if( xTickCount < listGET_LIST_ITEM_VALUE( &( pxTCB->xGenericListItem ) ) )                                                                      \\r
 251                 {                                                                                                                                                                                                                       \\r
 252                         break;                                                                                                                                                                                                  \\r
 253                 }                                                                                                                                                                                                                       \\r
 254                 vListRemove( &( pxTCB->xGenericListItem ) );                                                                                                                            \\r
 255                 /* Is the task waiting on an event also? */                                                                                                                                     \\r
 256                 if( pxTCB->xEventListItem.pvContainer )                                                                                                                                         \\r
 257                 {                                                                                                                                                                                                                       \\r
 258                         vListRemove( &( pxTCB->xEventListItem ) );                                                                                                                              \\r
 259                 }                                                                                                                                                                                                                       \\r
 260                 prvAddTaskToReadyQueue( pxTCB );                                                                                                                                                        \\r
 261         }                                                                                                                                                                                                                               \\r
 262 }\r
 263 /*-----------------------------------------------------------*/\r
 264 \r
 265 /*\r
 266  * Several functions take an xTaskHandle parameter that can optionally be NULL,\r
 267  * where NULL is used to indicate that the handle of the currently executing\r
 268  * task should be used in place of the parameter.  This macro simply checks to\r
 269  * see if the parameter is NULL and returns a pointer to the appropriate TCB.\r
 270  */\r
 271 #define prvGetTCBFromHandle( pxHandle ) ( ( pxHandle == NULL ) ? ( tskTCB * ) pxCurrentTCB : ( tskTCB * ) pxHandle )\r
 272 \r
 273 \r
 274 /* File private functions. --------------------------------*/\r
 275 \r
 276 /*\r
 277  * Utility to ready a TCB for a given task.  Mainly just copies the parameters\r
 278  * into the TCB structure.\r
 279  */\r
 280 static void prvInitialiseTCBVariables( tskTCB *pxTCB, const signed portCHAR * const pcName, unsigned portBASE_TYPE uxPriority );\r
 281 \r
 282 /*\r
 283  * Utility to ready all the lists used by the scheduler.  This is called\r
 284  * automatically upon the creation of the first task.\r
 285  */\r
 286 static void prvInitialiseTaskLists( void );\r
 287 \r
 288 /*\r
 289  * The idle task, which as all tasks is implemented as a never ending loop.\r
 290  * The idle task is automatically created and added to the ready lists upon\r
 291  * creation of the first user task.\r
 292  *\r
 293  * The portTASK_FUNCTION_PROTO() macro is used to allow port/compiler specific\r
 294  * language extensions.  The equivalent prototype for this function is:\r
 295  *\r
 296  * void prvIdleTask( void *pvParameters );\r
 297  *\r
 298  */\r
 299 static portTASK_FUNCTION_PROTO( prvIdleTask, pvParameters );\r
 300 \r
 301 /*\r
 302  * Utility to free all memory allocated by the scheduler to hold a TCB,\r
 303  * including the stack pointed to by the TCB.\r
 304  *\r
 305  * This does not free memory allocated by the task itself (i.e. memory\r
 306  * allocated by calls to pvPortMalloc from within the tasks application code).\r
 307  */\r
 308 #if ( ( INCLUDE_vTaskDelete == 1 ) || ( INCLUDE_vTaskCleanUpResources == 1 ) )\r
 309         static void prvDeleteTCB( tskTCB *pxTCB );\r
 310 #endif\r
 311 \r
 312 /*\r
 313  * Used only by the idle task.  This checks to see if anything has been placed\r
 314  * in the list of tasks waiting to be deleted.  If so the task is cleaned up\r
 315  * and its TCB deleted.\r
 316  */\r
 317 static void prvCheckTasksWaitingTermination( void );\r
 318 \r
 319 /*\r
 320  * Allocates memory from the heap for a TCB and associated stack.  Checks the\r
 321  * allocation was successful.\r
 322  */\r
 323 static tskTCB *prvAllocateTCBAndStack( unsigned portSHORT usStackDepth );\r
 324 \r
 325 /*\r
 326  * Called from vTaskList.  vListTasks details all the tasks currently under\r
 327  * control of the scheduler.  The tasks may be in one of a number of lists.\r
 328  * prvListTaskWithinSingleList accepts a list and details the tasks from\r
 329  * within just that list.\r
 330  *\r
 331  * THIS FUNCTION IS INTENDED FOR DEBUGGING ONLY, AND SHOULD NOT BE CALLED FROM\r
 332  * NORMAL APPLICATION CODE.\r
 333  */\r
 334 #if ( configUSE_TRACE_FACILITY == 1 )\r
 335 \r
 336         static void prvListTaskWithinSingleList( const signed portCHAR *pcWriteBuffer, xList *pxList, signed portCHAR cStatus );\r
 337 \r
 338 #endif\r
 339 \r
 340 /*\r
 341  * When a task is created, the stack of the task is filled with a known value.\r
 342  * This function determines the 'high water mark' of the task stack by\r
 343  * determining how much of the stack remains at the original preset value.\r
 344  */\r
 345 #if ( ( configUSE_TRACE_FACILITY == 1 ) || ( INCLUDE_uxTaskGetStackHighWaterMark == 1 ) )\r
 346 \r
 347         unsigned portSHORT usTaskCheckFreeStackSpace( const unsigned portCHAR * pucStackByte );\r
 348 \r
 349 #endif\r
 350 \r
 351 \r
 352 /*lint +e956 */\r
 353 \r
 354 \r
 355 \r
 356 /*-----------------------------------------------------------\r
 357  * TASK CREATION API documented in task.h\r
 358  *----------------------------------------------------------*/\r
 359 \r
 360 signed portBASE_TYPE xTaskCreate( pdTASK_CODE pvTaskCode, const signed portCHAR * const pcName, unsigned portSHORT usStackDepth, void *pvParameters, unsigned portBASE_TYPE uxPriority, xTaskHandle *pxCreatedTask )\r
 361 {\r
 362 signed portBASE_TYPE xReturn;\r
 363 tskTCB * pxNewTCB;\r
 364 \r
 365         /* Allocate the memory required by the TCB and stack for the new task.\r
 366         checking that the allocation was successful. */\r
 367         pxNewTCB = prvAllocateTCBAndStack( usStackDepth );\r
 368 \r
 369         if( pxNewTCB != NULL )\r
 370         {               \r
 371                 portSTACK_TYPE *pxTopOfStack;\r
 372 \r
 373                 /* Setup the newly allocated TCB with the initial state of the task. */\r
 374                 prvInitialiseTCBVariables( pxNewTCB, pcName, uxPriority );\r
 375 \r
 376                 /* Calculate the top of stack address.  This depends on whether the\r
 377                 stack grows from high memory to low (as per the 80x86) or visa versa.\r
 378                 portSTACK_GROWTH is used to make the result positive or negative as\r
 379                 required by the port. */\r
 380                 #if portSTACK_GROWTH < 0\r
 381                 {\r
 382                         pxTopOfStack = pxNewTCB->pxStack + ( usStackDepth - 1 );\r
 383                 }\r
 384                 #else\r
 385                 {\r
 386                         pxTopOfStack = pxNewTCB->pxStack;       \r
 387 \r
 388                         /* If we want to use stack checking on architectures that use\r
 389                         a positive stack growth direction then we also need to store the\r
 390                         other extreme of the stack space. */\r
 391                         pxNewTCB->pxEndOfStack = pxNewTCB->pxStack + ( usStackDepth - 1 );\r
 392                 }\r
 393                 #endif\r
 394 \r
 395                 /* Initialize the TCB stack to look as if the task was already running,\r
 396                 but had been interrupted by the scheduler.  The return address is set\r
 397                 to the start of the task function. Once the stack has been initialised\r
 398                 the     top of stack variable is updated. */\r
 399                 pxNewTCB->pxTopOfStack = pxPortInitialiseStack( pxTopOfStack, pvTaskCode, pvParameters );\r
 400 \r
 401                 /* We are going to manipulate the task queues to add this task to a\r
 402                 ready list, so must make sure no interrupts occur. */\r
 403                 portENTER_CRITICAL();\r
 404                 {\r
 405                         uxCurrentNumberOfTasks++;\r
 406                         if( uxCurrentNumberOfTasks == ( unsigned portBASE_TYPE ) 1 )\r
 407                         {\r
 408                                 /* As this is the first task it must also be the current task. */\r
 409                                 pxCurrentTCB =  pxNewTCB;\r
 410 \r
 411                                 /* This is the first task to be created so do the preliminary\r
 412                                 initialisation required.  We will not recover if this call\r
 413                                 fails, but we will report the failure. */\r
 414                                 prvInitialiseTaskLists();\r
 415                         }\r
 416                         else\r
 417                         {       \r
 418                                 /* If the scheduler is not already running, make this task the\r
 419                                 current task if it is the highest priority task to be created\r
 420                                 so far. */\r
 421                                 if( xSchedulerRunning == pdFALSE )\r
 422                                 {\r
 423                                         if( pxCurrentTCB->uxPriority <= uxPriority )\r
 424                                         {\r
 425                                                 pxCurrentTCB = pxNewTCB;        \r
 426                                         }\r
 427                                 }\r
 428                         }                               \r
 429 \r
 430                         /* Remember the top priority to make context switching faster.  Use\r
 431                         the priority in pxNewTCB as this has been capped to a valid value. */\r
 432                         if( pxNewTCB->uxPriority > uxTopUsedPriority )\r
 433                         {\r
 434                                 uxTopUsedPriority = pxNewTCB->uxPriority;\r
 435                         }\r
 436 \r
 437                         #if ( configUSE_TRACE_FACILITY == 1 )\r
 438                         {\r
 439                                 /* Add a counter into the TCB for tracing only. */\r
 440                                 pxNewTCB->uxTCBNumber = uxTaskNumber;\r
 441                                 uxTaskNumber++;\r
 442                         }\r
 443                         #endif\r
 444 \r
 445                         prvAddTaskToReadyQueue( pxNewTCB );\r
 446 \r
 447                         xReturn = pdPASS;\r
 448                         traceTASK_CREATE( pxNewTCB );\r
 449                 }\r
 450                 portEXIT_CRITICAL();\r
 451         }\r
 452         else\r
 453         {\r
 454                 xReturn = errCOULD_NOT_ALLOCATE_REQUIRED_MEMORY;\r
 455                 traceTASK_CREATE_FAILED( pxNewTCB );\r
 456         }\r
 457 \r
 458         if( xReturn == pdPASS )\r
 459         {\r
 460                 if( ( void * ) pxCreatedTask != NULL )\r
 461                 {\r
 462                         /* Pass the TCB out - in an anonymous way.  The calling function/\r
 463                         task can use this as a handle to delete the task later if\r
 464                         required.*/\r
 465                         *pxCreatedTask = ( xTaskHandle ) pxNewTCB;\r
 466                 }\r
 467 \r
 468                 if( xSchedulerRunning != pdFALSE )\r
 469                 {\r
 470                         /* If the created task is of a higher priority than the current task\r
 471                         then it should run now. */\r
 472                         if( pxCurrentTCB->uxPriority < uxPriority )\r
 473                         {\r
 474                                 taskYIELD();\r
 475                         }\r
 476                 }\r
 477         }\r
 478 \r
 479         return xReturn;\r
 480 }\r
 481 /*-----------------------------------------------------------*/\r
 482 \r
 483 #if ( INCLUDE_vTaskDelete == 1 )\r
 484 \r
 485         void vTaskDelete( xTaskHandle pxTaskToDelete )\r
 486         {\r
 487         tskTCB *pxTCB;\r
 488 \r
 489                 taskENTER_CRITICAL();\r
 490                 {\r
 491                         /* Ensure a yield is performed if the current task is being\r
 492                         deleted. */\r
 493                         if( pxTaskToDelete == pxCurrentTCB )\r
 494                         {\r
 495                                 pxTaskToDelete = NULL;\r
 496                         }\r
 497 \r
 498                         /* If null is passed in here then we are deleting ourselves. */\r
 499                         pxTCB = prvGetTCBFromHandle( pxTaskToDelete );\r
 500 \r
 501                         traceTASK_DELETE( pxTCB );\r
 502 \r
 503                         /* Remove task from the ready list and place in the     termination list.\r
 504                         This will stop the task from be scheduled.  The idle task will check\r
 505                         the termination list and free up any memory allocated by the\r
 506                         scheduler for the TCB and stack. */\r
 507                         vListRemove( &( pxTCB->xGenericListItem ) );\r
 508 \r
 509                         /* Is the task waiting on an event also? */                                                                                             \r
 510                         if( pxTCB->xEventListItem.pvContainer )\r
 511                         {\r
 512                                 vListRemove( &( pxTCB->xEventListItem ) );\r
 513                         }\r
 514 \r
 515                         vListInsertEnd( ( xList * ) &xTasksWaitingTermination, &( pxTCB->xGenericListItem ) );\r
 516 \r
 517                         /* Increment the ucTasksDeleted variable so the idle task knows\r
 518                         there is a task that has been deleted and that it should therefore\r
 519                         check the xTasksWaitingTermination list. */\r
 520                         ++uxTasksDeleted;\r
 521                 }\r
 522                 taskEXIT_CRITICAL();\r
 523 \r
 524                 /* Force a reschedule if we have just deleted the current task. */\r
 525                 if( xSchedulerRunning != pdFALSE )\r
 526                 {\r
 527                         if( ( void * ) pxTaskToDelete == NULL )\r
 528                         {\r
 529                                 taskYIELD();\r
 530                         }\r
 531                 }\r
 532         }\r
 533 \r
 534 #endif\r
 535 \r
 536 \r
 537 \r
 538 \r
 539 \r
 540 \r
 541 /*-----------------------------------------------------------\r
 542  * TASK CONTROL API documented in task.h\r
 543  *----------------------------------------------------------*/\r
 544 \r
 545 #if ( INCLUDE_vTaskDelayUntil == 1 )\r
 546 \r
 547         void vTaskDelayUntil( portTickType * const pxPreviousWakeTime, portTickType xTimeIncrement )\r
 548         {\r
 549         portTickType xTimeToWake;\r
 550         portBASE_TYPE xAlreadyYielded, xShouldDelay = pdFALSE;\r
 551 \r
 552                 vTaskSuspendAll();\r
 553                 {\r
 554                         /* Generate the tick time at which the task wants to wake. */\r
 555                         xTimeToWake = *pxPreviousWakeTime + xTimeIncrement;\r
 556 \r
 557                         if( xTickCount < *pxPreviousWakeTime )\r
 558                         {\r
 559                                 /* The tick count has overflowed since this function was\r
 560                                 lasted called.  In this case the only time we should ever\r
 561                                 actually delay is if the wake time has also     overflowed,\r
 562                                 and the wake time is greater than the tick time.  When this\r
 563                                 is the case it is as if neither time had overflowed. */\r
 564                                 if( ( xTimeToWake < *pxPreviousWakeTime ) && ( xTimeToWake > xTickCount ) )\r
 565                                 {\r
 566                                         xShouldDelay = pdTRUE;\r
 567                                 }\r
 568                         }\r
 569                         else\r
 570                         {\r
 571                                 /* The tick time has not overflowed.  In this case we will\r
 572                                 delay if either the wake time has overflowed, and/or the\r
 573                                 tick time is less than the wake time. */\r
 574                                 if( ( xTimeToWake < *pxPreviousWakeTime ) || ( xTimeToWake > xTickCount ) )\r
 575                                 {\r
 576                                         xShouldDelay = pdTRUE;\r
 577                                 }\r
 578                         }\r
 579 \r
 580                         /* Update the wake time ready for the next call. */\r
 581                         *pxPreviousWakeTime = xTimeToWake;\r
 582 \r
 583                         if( xShouldDelay )\r
 584                         {\r
 585                                 traceTASK_DELAY_UNTIL();\r
 586 \r
 587                                 /* We must remove ourselves from the ready list before adding\r
 588                                 ourselves to the blocked list as the same list item is used for\r
 589                                 both lists. */\r
 590                                 vListRemove( ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );\r
 591 \r
 592                                 /* The list item will be inserted in wake time order. */\r
 593                                 listSET_LIST_ITEM_VALUE( &( pxCurrentTCB->xGenericListItem ), xTimeToWake );\r
 594 \r
 595                                 if( xTimeToWake < xTickCount )\r
 596                                 {\r
 597                                         /* Wake time has overflowed.  Place this item in the\r
 598                                         overflow list. */\r
 599                                         vListInsert( ( xList * ) pxOverflowDelayedTaskList, ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );\r
 600                                 }\r
 601                                 else\r
 602                                 {\r
 603                                         /* The wake time has not overflowed, so we can use the\r
 604                                         current block list. */\r
 605                                         vListInsert( ( xList * ) pxDelayedTaskList, ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );\r
 606                                 }\r
 607                         }\r
 608                 }\r
 609                 xAlreadyYielded = xTaskResumeAll();\r
 610 \r
 611                 /* Force a reschedule if xTaskResumeAll has not already done so, we may\r
 612                 have put ourselves to sleep. */\r
 613                 if( !xAlreadyYielded )\r
 614                 {\r
 615                         taskYIELD();\r
 616                 }\r
 617         }       \r
 618         \r
 619 #endif\r
 620 /*-----------------------------------------------------------*/\r
 621 \r
 622 #if ( INCLUDE_vTaskDelay == 1 )\r
 623 \r
 624         void vTaskDelay( portTickType xTicksToDelay )\r
 625         {\r
 626         portTickType xTimeToWake;\r
 627         signed portBASE_TYPE xAlreadyYielded = pdFALSE;\r
 628 \r
 629                 /* A delay time of zero just forces a reschedule. */\r
 630                 if( xTicksToDelay > ( portTickType ) 0 )\r
 631                 {\r
 632                         vTaskSuspendAll();\r
 633                         {\r
 634                                 traceTASK_DELAY();\r
 635 \r
 636                                 /* A task that is removed from the event list while the\r
 637                                 scheduler is suspended will not get placed in the ready\r
 638                                 list or removed from the blocked list until the scheduler\r
 639                                 is resumed.\r
 640                                 \r
 641                                 This task cannot be in an event list as it is the currently\r
 642                                 executing task. */\r
 643 \r
 644                                 /* Calculate the time to wake - this may overflow but this is\r
 645                                 not a problem. */\r
 646                                 xTimeToWake = xTickCount + xTicksToDelay;\r
 647 \r
 648                                 /* We must remove ourselves from the ready list before adding\r
 649                                 ourselves to the blocked list as the same list item is used for\r
 650                                 both lists. */\r
 651                                 vListRemove( ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );\r
 652 \r
 653                                 /* The list item will be inserted in wake time order. */\r
 654                                 listSET_LIST_ITEM_VALUE( &( pxCurrentTCB->xGenericListItem ), xTimeToWake );\r
 655 \r
 656                                 if( xTimeToWake < xTickCount )\r
 657                                 {\r
 658                                         /* Wake time has overflowed.  Place this item in the\r
 659                                         overflow list. */\r
 660                                         vListInsert( ( xList * ) pxOverflowDelayedTaskList, ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );\r
 661                                 }\r
 662                                 else\r
 663                                 {\r
 664                                         /* The wake time has not overflowed, so we can use the\r
 665                                         current block list. */\r
 666                                         vListInsert( ( xList * ) pxDelayedTaskList, ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );\r
 667                                 }\r
 668                         }\r
 669                         xAlreadyYielded = xTaskResumeAll();\r
 670                 }\r
 671                 \r
 672                 /* Force a reschedule if xTaskResumeAll has not already done so, we may\r
 673                 have put ourselves to sleep. */\r
 674                 if( !xAlreadyYielded )\r
 675                 {\r
 676                         taskYIELD();\r
 677                 }\r
 678         }\r
 679         \r
 680 #endif\r
 681 /*-----------------------------------------------------------*/\r
 682 \r
 683 #if ( INCLUDE_uxTaskPriorityGet == 1 )\r
 684 \r
 685         unsigned portBASE_TYPE uxTaskPriorityGet( xTaskHandle pxTask )\r
 686         {\r
 687         tskTCB *pxTCB;\r
 688         unsigned portBASE_TYPE uxReturn;\r
 689 \r
 690                 taskENTER_CRITICAL();\r
 691                 {\r
 692                         /* If null is passed in here then we are changing the\r
 693                         priority of the calling function. */\r
 694                         pxTCB = prvGetTCBFromHandle( pxTask );\r
 695                         uxReturn = pxTCB->uxPriority;\r
 696                 }\r
 697                 taskEXIT_CRITICAL();\r
 698 \r
 699                 return uxReturn;\r
 700         }\r
 701 \r
 702 #endif\r
 703 /*-----------------------------------------------------------*/\r
 704 \r
 705 #if ( INCLUDE_vTaskPrioritySet == 1 )\r
 706 \r
 707         void vTaskPrioritySet( xTaskHandle pxTask, unsigned portBASE_TYPE uxNewPriority )\r
 708         {\r
 709         tskTCB *pxTCB;\r
 710         unsigned portBASE_TYPE uxCurrentPriority, xYieldRequired = pdFALSE;\r
 711 \r
 712                 /* Ensure the new priority is valid. */\r
 713                 if( uxNewPriority >= configMAX_PRIORITIES )\r
 714                 {\r
 715                         uxNewPriority = configMAX_PRIORITIES - 1;\r
 716                 }\r
 717 \r
 718                 taskENTER_CRITICAL();\r
 719                 {\r
 720                         if( pxTask == pxCurrentTCB )\r
 721                         {\r
 722                                 pxTask = NULL;\r
 723                         }\r
 724 \r
 725                         /* If null is passed in here then we are changing the\r
 726                         priority of the calling function. */\r
 727                         pxTCB = prvGetTCBFromHandle( pxTask );\r
 728                         \r
 729                         traceTASK_PRIORITY_SET( pxTask, uxNewPriority );\r
 730 \r
 731                         #if ( configUSE_MUTEXES == 1 )\r
 732                         {\r
 733                                 uxCurrentPriority = pxTCB->uxBasePriority;\r
 734                         }\r
 735                         #else\r
 736                         {\r
 737                                 uxCurrentPriority = pxTCB->uxPriority;\r
 738                         }\r
 739                         #endif\r
 740 \r
 741                         if( uxCurrentPriority != uxNewPriority )\r
 742                         {\r
 743                                 /* The priority change may have readied a task of higher\r
 744                                 priority than the calling task. */\r
 745                                 if( uxNewPriority > uxCurrentPriority )\r
 746                                 {\r
 747                                         if( pxTask != NULL )\r
 748                                         {\r
 749                                                 /* The priority of another task is being raised.  If we\r
 750                                                 were raising the priority of the currently running task\r
 751                                                 there would be no need to switch as it must have already\r
 752                                                 been the highest priority task. */\r
 753                                                 xYieldRequired = pdTRUE;\r
 754                                         }\r
 755                                 }\r
 756                                 else if( pxTask == NULL )\r
 757                                 {\r
 758                                         /* Setting our own priority down means there may now be another\r
 759                                         task of higher priority that is ready to execute. */\r
 760                                         xYieldRequired = pdTRUE;\r
 761                                 }\r
 762                         \r
 763                                 \r
 764 \r
 765                                 #if ( configUSE_MUTEXES == 1 )\r
 766                                 {\r
 767                                         /* Only change the priority being used if the task is not\r
 768                                         currently using an inherited priority. */\r
 769                                         if( pxTCB->uxBasePriority == pxTCB->uxPriority )\r
 770                                         {\r
 771                                                 pxTCB->uxPriority = uxNewPriority;\r
 772                                         }\r
 773                                         \r
 774                                         /* The base priority gets set whatever. */\r
 775                                         pxTCB->uxBasePriority = uxNewPriority;                                  \r
 776                                 }\r
 777                                 #else\r
 778                                 {\r
 779                                         pxTCB->uxPriority = uxNewPriority;\r
 780                                 }\r
 781                                 #endif\r
 782 \r
 783                                 listSET_LIST_ITEM_VALUE( &( pxTCB->xEventListItem ), ( configMAX_PRIORITIES - ( portTickType ) uxNewPriority ) );\r
 784 \r
 785                                 /* If the task is in the blocked or suspended list we need do\r
 786                                 nothing more than change it's priority variable. However, if\r
 787                                 the task is in a ready list it needs to be removed and placed\r
 788                                 in the queue appropriate to its new priority. */\r
 789                                 if( listIS_CONTAINED_WITHIN( &( pxReadyTasksLists[ uxCurrentPriority ] ), &( pxTCB->xGenericListItem ) ) )\r
 790                                 {\r
 791                                         /* The task is currently in its ready list - remove before adding\r
 792                                         it to it's new ready list.  As we are in a critical section we\r
 793                                         can do this even if the scheduler is suspended. */\r
 794                                         vListRemove( &( pxTCB->xGenericListItem ) );\r
 795                                         prvAddTaskToReadyQueue( pxTCB );\r
 796                                 }                       \r
 797                                 \r
 798                                 if( xYieldRequired == pdTRUE )\r
 799                                 {\r
 800                                         taskYIELD();\r
 801                                 }                               \r
 802                         }\r
 803                 }\r
 804                 taskEXIT_CRITICAL();\r
 805         }\r
 806 \r
 807 #endif\r
 808 /*-----------------------------------------------------------*/\r
 809 \r
 810 #if ( INCLUDE_vTaskSuspend == 1 )\r
 811 \r
 812         void vTaskSuspend( xTaskHandle pxTaskToSuspend )\r
 813         {\r
 814         tskTCB *pxTCB;\r
 815 \r
 816                 taskENTER_CRITICAL();\r
 817                 {\r
 818                         /* Ensure a yield is performed if the current task is being\r
 819                         suspended. */\r
 820                         if( pxTaskToSuspend == pxCurrentTCB )\r
 821                         {\r
 822                                 pxTaskToSuspend = NULL;\r
 823                         }\r
 824 \r
 825                         /* If null is passed in here then we are suspending ourselves. */\r
 826                         pxTCB = prvGetTCBFromHandle( pxTaskToSuspend );\r
 827 \r
 828                         traceTASK_SUSPEND( pxTaskToSuspend );\r
 829 \r
 830                         /* Remove task from the ready/delayed list and place in the     suspended list. */\r
 831                         vListRemove( &( pxTCB->xGenericListItem ) );\r
 832 \r
 833                         /* Is the task waiting on an event also? */                                                                                             \r
 834                         if( pxTCB->xEventListItem.pvContainer )\r
 835                         {\r
 836                                 vListRemove( &( pxTCB->xEventListItem ) );\r
 837                         }\r
 838 \r
 839                         vListInsertEnd( ( xList * ) &xSuspendedTaskList, &( pxTCB->xGenericListItem ) );\r
 840                 }\r
 841                 taskEXIT_CRITICAL();\r
 842 \r
 843                 /* We may have just suspended the current task. */\r
 844                 if( ( void * ) pxTaskToSuspend == NULL )\r
 845                 {\r
 846                         taskYIELD();\r
 847                 }\r
 848         }\r
 849 \r
 850 #endif\r
 851 /*-----------------------------------------------------------*/\r
 852 \r
 853 #if ( INCLUDE_vTaskSuspend == 1 )\r
 854 \r
 855         signed portBASE_TYPE xTaskIsTaskSuspended( xTaskHandle xTask )\r
 856         {\r
 857         portBASE_TYPE xReturn = pdFALSE;\r
 858         const tskTCB * const pxTCB = ( tskTCB * ) xTask;\r
 859 \r
 860                 /* Is the task we are attempting to resume actually in the\r
 861                 suspended list? */\r
 862                 if( listIS_CONTAINED_WITHIN( &xSuspendedTaskList, &( pxTCB->xGenericListItem ) ) != pdFALSE )\r
 863                 {\r
 864                         /* Has the task already been resumed from within an ISR? */\r
 865                         if( listIS_CONTAINED_WITHIN( &xPendingReadyList, &( pxTCB->xEventListItem ) ) != pdTRUE )\r
 866                         {                       \r
 867                                 /* Is it in the suspended list because it is in the\r
 868                                 Suspended state?  It is possible to be in the suspended\r
 869                                 list because it is blocked on a task with no timeout\r
 870                                 specified. */\r
 871                                 if( listIS_CONTAINED_WITHIN( NULL, &( pxTCB->xEventListItem ) ) == pdTRUE )\r
 872                                 {\r
 873                                         xReturn = pdTRUE;\r
 874                                 }\r
 875                         }\r
 876                 }\r
 877 \r
 878                 return xReturn;\r
 879         }\r
 880 \r
 881 #endif\r
 882 /*-----------------------------------------------------------*/\r
 883 \r
 884 #if ( INCLUDE_vTaskSuspend == 1 )\r
 885 \r
 886         void vTaskResume( xTaskHandle pxTaskToResume )\r
 887         {\r
 888         tskTCB *pxTCB;\r
 889 \r
 890                 /* Remove the task from whichever list it is currently in, and place\r
 891                 it in the ready list. */\r
 892                 pxTCB = ( tskTCB * ) pxTaskToResume;\r
 893 \r
 894                 /* The parameter cannot be NULL as it is impossible to resume the\r
 895                 currently executing task. */\r
 896                 if( ( pxTCB != NULL ) && ( pxTCB != pxCurrentTCB ) )\r
 897                 {\r
 898                         taskENTER_CRITICAL();\r
 899                         {\r
 900                                 if( xTaskIsTaskSuspended( pxTCB ) == pdTRUE )\r
 901                                 {\r
 902                                         traceTASK_RESUME( pxTCB );\r
 903 \r
 904                                         /* As we are in a critical section we can access the ready\r
 905                                         lists even if the scheduler is suspended. */\r
 906                                         vListRemove(  &( pxTCB->xGenericListItem ) );\r
 907                                         prvAddTaskToReadyQueue( pxTCB );\r
 908 \r
 909                                         /* We may have just resumed a higher priority task. */\r
 910                                         if( pxTCB->uxPriority >= pxCurrentTCB->uxPriority )\r
 911                                         {\r
 912                                                 /* This yield may not cause the task just resumed to run, but\r
 913                                                 will leave the lists in the correct state for the next yield. */\r
 914                                                 taskYIELD();\r
 915                                         }\r
 916                                 }\r
 917                         }\r
 918                         taskEXIT_CRITICAL();\r
 919                 }\r
 920         }\r
 921 \r
 922 #endif\r
 923 \r
 924 /*-----------------------------------------------------------*/\r
 925 \r
 926 #if ( ( INCLUDE_xTaskResumeFromISR == 1 ) && ( INCLUDE_vTaskSuspend == 1 ) )\r
 927 \r
 928         portBASE_TYPE xTaskResumeFromISR( xTaskHandle pxTaskToResume )\r
 929         {\r
 930         portBASE_TYPE xYieldRequired = pdFALSE;\r
 931         tskTCB *pxTCB;\r
 932 \r
 933                 pxTCB = ( tskTCB * ) pxTaskToResume;\r
 934 \r
 935                 if( xTaskIsTaskSuspended( pxTCB ) == pdTRUE )\r
 936                 {\r
 937                         traceTASK_RESUME_FROM_ISR( pxTCB );\r
 938 \r
 939                         if( uxSchedulerSuspended == ( unsigned portBASE_TYPE ) pdFALSE )\r
 940                         {\r
 941                                 xYieldRequired = ( pxTCB->uxPriority >= pxCurrentTCB->uxPriority );\r
 942                                 vListRemove(  &( pxTCB->xGenericListItem ) );   \r
 943                                 prvAddTaskToReadyQueue( pxTCB );\r
 944                         }\r
 945                         else\r
 946                         {\r
 947                                 /* We cannot access the delayed or ready lists, so will hold this\r
 948                                 task pending until the scheduler is resumed, at which point a\r
 949                                 yield will be performed if necessary. */\r
 950                                 vListInsertEnd( ( xList * ) &( xPendingReadyList ), &( pxTCB->xEventListItem ) );\r
 951                         }\r
 952                 }\r
 953 \r
 954                 return xYieldRequired;\r
 955         }\r
 956 \r
 957 #endif\r
 958 \r
 959 \r
 960 \r
 961 \r
 962 /*-----------------------------------------------------------\r
 963  * PUBLIC SCHEDULER CONTROL documented in task.h\r
 964  *----------------------------------------------------------*/\r
 965 \r
 966 \r
 967 void vTaskStartScheduler( void )\r
 968 {\r
 969 portBASE_TYPE xReturn;\r
 970 \r
 971         /* Add the idle task at the lowest priority. */\r
 972         xReturn = xTaskCreate( prvIdleTask, ( signed portCHAR * ) "IDLE", tskIDLE_STACK_SIZE, ( void * ) NULL, tskIDLE_PRIORITY, ( xTaskHandle * ) NULL );\r
 973 \r
 974         if( xReturn == pdPASS )\r
 975         {\r
 976                 /* Interrupts are turned off here, to ensure a tick does not occur\r
 977                 before or during the call to xPortStartScheduler().  The stacks of\r
 978                 the created tasks contain a status word with interrupts switched on\r
 979                 so interrupts will automatically get re-enabled when the first task\r
 980                 starts to run.\r
 981                 \r
 982                 STEPPING THROUGH HERE USING A DEBUGGER CAN CAUSE BIG PROBLEMS IF THE\r
 983                 DEBUGGER ALLOWS INTERRUPTS TO BE PROCESSED. */\r
 984                 portDISABLE_INTERRUPTS();\r
 985 \r
 986                 xSchedulerRunning = pdTRUE;\r
 987                 xTickCount = ( portTickType ) 0;\r
 988 \r
 989                 /* Setting up the timer tick is hardware specific and thus in the\r
 990                 portable interface. */\r
 991                 if( xPortStartScheduler() )\r
 992                 {\r
 993                         /* Should not reach here as if the scheduler is running the\r
 994                         function will not return. */\r
 995                 }\r
 996                 else\r
 997                 {\r
 998                         /* Should only reach here if a task calls xTaskEndScheduler(). */\r
 999                 }\r
1000         }\r
1001 }\r
1002 /*-----------------------------------------------------------*/\r
1003 \r
1004 void vTaskEndScheduler( void )\r
1005 {\r
1006         /* Stop the scheduler interrupts and call the portable scheduler end\r
1007         routine so the original ISRs can be restored if necessary.  The port\r
1008         layer must ensure interrupts enable     bit is left in the correct state. */\r
1009         portDISABLE_INTERRUPTS();\r
1010         xSchedulerRunning = pdFALSE;\r
1011         vPortEndScheduler();\r
1012 }\r
1013 /*----------------------------------------------------------*/\r
1014 \r
1015 void vTaskSuspendAll( void )\r
1016 {\r
1017         portENTER_CRITICAL();\r
1018                 ++uxSchedulerSuspended;\r
1019         portEXIT_CRITICAL();\r
1020 }\r
1021 /*----------------------------------------------------------*/\r
1022 \r
1023 signed portBASE_TYPE xTaskResumeAll( void )\r
1024 {\r
1025 register tskTCB *pxTCB;\r
1026 signed portBASE_TYPE xAlreadyYielded = pdFALSE;\r
1027 \r
1028         /* It is possible that an ISR caused a task to be removed from an event\r
1029         list while the scheduler was suspended.  If this was the case then the\r
1030         removed task will have been added to the xPendingReadyList.  Once the\r
1031         scheduler has been resumed it is safe to move all the pending ready\r
1032         tasks from this list into their appropriate ready list. */\r
1033         portENTER_CRITICAL();\r
1034         {\r
1035                 --uxSchedulerSuspended;\r
1036 \r
1037                 if( uxSchedulerSuspended == ( unsigned portBASE_TYPE ) pdFALSE )\r
1038                 {                       \r
1039                         if( uxCurrentNumberOfTasks > ( unsigned portBASE_TYPE ) 0 )\r
1040                         {\r
1041                                 portBASE_TYPE xYieldRequired = pdFALSE;\r
1042                                 \r
1043                                 /* Move any readied tasks from the pending list into the\r
1044                                 appropriate ready list. */\r
1045                                 while( ( pxTCB = ( tskTCB * ) listGET_OWNER_OF_HEAD_ENTRY(  ( ( xList * ) &xPendingReadyList ) ) ) != NULL )\r
1046                                 {\r
1047                                         vListRemove( &( pxTCB->xEventListItem ) );\r
1048                                         vListRemove( &( pxTCB->xGenericListItem ) );\r
1049                                         prvAddTaskToReadyQueue( pxTCB );\r
1050                                         \r
1051                                         /* If we have moved a task that has a priority higher than\r
1052                                         the current task then we should yield. */\r
1053                                         if( pxTCB->uxPriority >= pxCurrentTCB->uxPriority )\r
1054                                         {\r
1055                                                 xYieldRequired = pdTRUE;\r
1056                                         }\r
1057                                 }\r
1058 \r
1059                                 /* If any ticks occurred while the scheduler was suspended then\r
1060                                 they should be processed now.  This ensures the tick count does not\r
1061                                 slip, and that any delayed tasks are resumed at the correct time. */\r
1062                                 if( uxMissedTicks > ( unsigned portBASE_TYPE ) 0 )\r
1063                                 {\r
1064                                         while( uxMissedTicks > ( unsigned portBASE_TYPE ) 0 )\r
1065                                         {\r
1066                                                 vTaskIncrementTick();\r
1067                                                 --uxMissedTicks;\r
1068                                         }\r
1069 \r
1070                                         /* As we have processed some ticks it is appropriate to yield\r
1071                                         to ensure the highest priority task that is ready to run is\r
1072                                         the task actually running. */\r
1073                                         #if configUSE_PREEMPTION == 1\r
1074                                         {\r
1075                                                 xYieldRequired = pdTRUE;\r
1076                                         }\r
1077                                         #endif\r
1078                                 }\r
1079                                 \r
1080                                 if( ( xYieldRequired == pdTRUE ) || ( xMissedYield == pdTRUE ) )\r
1081                                 {\r
1082                                         xAlreadyYielded = pdTRUE;\r
1083                                         xMissedYield = pdFALSE;\r
1084                                         taskYIELD();\r
1085                                 }\r
1086                         }\r
1087                 }\r
1088         }\r
1089         portEXIT_CRITICAL();\r
1090 \r
1091         return xAlreadyYielded;\r
1092 }\r
1093 \r
1094 \r
1095 \r
1096 \r
1097 \r
1098 \r
1099 /*-----------------------------------------------------------\r
1100  * PUBLIC TASK UTILITIES documented in task.h\r
1101  *----------------------------------------------------------*/\r
1102 \r
1103 \r
1104 \r
1105 portTickType xTaskGetTickCount( void )\r
1106 {\r
1107 portTickType xTicks;\r
1108 \r
1109         /* Critical section required if running on a 16 bit processor. */\r
1110         taskENTER_CRITICAL();\r
1111         {\r
1112                 xTicks = xTickCount;\r
1113         }\r
1114         taskEXIT_CRITICAL();\r
1115 \r
1116         return xTicks;\r
1117 }\r
1118 /*-----------------------------------------------------------*/\r
1119 \r
1120 unsigned portBASE_TYPE uxTaskGetNumberOfTasks( void )\r
1121 {\r
1122 unsigned portBASE_TYPE uxNumberOfTasks;\r
1123 \r
1124         taskENTER_CRITICAL();\r
1125                 uxNumberOfTasks = uxCurrentNumberOfTasks;\r
1126         taskEXIT_CRITICAL();\r
1127 \r
1128         return uxNumberOfTasks;\r
1129 }\r
1130 /*-----------------------------------------------------------*/\r
1131 \r
1132 #if ( ( configUSE_TRACE_FACILITY == 1 ) && ( INCLUDE_vTaskDelete == 1 ) && ( INCLUDE_vTaskSuspend == 1 ) )\r
1133 \r
1134         void vTaskList( signed portCHAR *pcWriteBuffer )\r
1135         {\r
1136         unsigned portBASE_TYPE uxQueue;\r
1137 \r
1138                 /* This is a VERY costly function that should be used for debug only.\r
1139                 It leaves interrupts disabled for a LONG time. */\r
1140 \r
1141         vTaskSuspendAll();\r
1142                 {\r
1143                         /* Run through all the lists that could potentially contain a TCB and\r
1144                         report the task name, state and stack high water mark. */\r
1145 \r
1146                         pcWriteBuffer[ 0 ] = ( signed portCHAR ) 0x00;\r
1147                         strcat( ( portCHAR * ) pcWriteBuffer, ( const portCHAR * ) "\r\n" );\r
1148 \r
1149                         uxQueue = uxTopUsedPriority + 1;\r
1150 \r
1151                         do\r
1152                         {\r
1153                                 uxQueue--;\r
1154 \r
1155                                 if( !listLIST_IS_EMPTY( &( pxReadyTasksLists[ uxQueue ] ) ) )\r
1156                                 {\r
1157                                         prvListTaskWithinSingleList( pcWriteBuffer, ( xList * ) &( pxReadyTasksLists[ uxQueue ] ), tskREADY_CHAR );                     \r
1158                                 }\r
1159                         }while( uxQueue > ( unsigned portSHORT ) tskIDLE_PRIORITY );\r
1160 \r
1161                         if( !listLIST_IS_EMPTY( pxDelayedTaskList ) )\r
1162                         {\r
1163                                 prvListTaskWithinSingleList( pcWriteBuffer, ( xList * ) pxDelayedTaskList, tskBLOCKED_CHAR );\r
1164                         }\r
1165 \r
1166                         if( !listLIST_IS_EMPTY( pxOverflowDelayedTaskList ) )\r
1167                         {\r
1168                                 prvListTaskWithinSingleList( pcWriteBuffer, ( xList * ) pxOverflowDelayedTaskList, tskBLOCKED_CHAR );\r
1169                         }\r
1170 \r
1171                         if( !listLIST_IS_EMPTY( &xTasksWaitingTermination ) )\r
1172                         {\r
1173                                 prvListTaskWithinSingleList( pcWriteBuffer, ( xList * ) &xTasksWaitingTermination, tskDELETED_CHAR );\r
1174                         }\r
1175 \r
1176                         if( !listLIST_IS_EMPTY( &xSuspendedTaskList ) )\r
1177                         {\r
1178                                 prvListTaskWithinSingleList( pcWriteBuffer, ( xList * ) &xSuspendedTaskList, tskSUSPENDED_CHAR );\r
1179                         }\r
1180                 }\r
1181         xTaskResumeAll();\r
1182         }\r
1183 \r
1184 #endif\r
1185 /*----------------------------------------------------------*/\r
1186 \r
1187 #if ( configUSE_TRACE_FACILITY == 1 )\r
1188 \r
1189         void vTaskStartTrace( signed portCHAR * pcBuffer, unsigned portLONG ulBufferSize )\r
1190         {\r
1191                 portENTER_CRITICAL();\r
1192                 {\r
1193                         pcTraceBuffer = ( signed portCHAR * )pcBuffer;\r
1194                         pcTraceBufferStart = pcBuffer;\r
1195                         pcTraceBufferEnd = pcBuffer + ( ulBufferSize - tskSIZE_OF_EACH_TRACE_LINE );\r
1196                         xTracing = pdTRUE;\r
1197                 }\r
1198                 portEXIT_CRITICAL();\r
1199         }\r
1200 \r
1201 #endif\r
1202 /*----------------------------------------------------------*/\r
1203 \r
1204 #if ( configUSE_TRACE_FACILITY == 1 )\r
1205 \r
1206         unsigned portLONG ulTaskEndTrace( void )\r
1207         {\r
1208         unsigned portLONG ulBufferLength;\r
1209 \r
1210                 portENTER_CRITICAL();\r
1211                         xTracing = pdFALSE;\r
1212                 portEXIT_CRITICAL();\r
1213 \r
1214                 ulBufferLength = ( unsigned portLONG ) ( pcTraceBuffer - pcTraceBufferStart );\r
1215 \r
1216                 return ulBufferLength;\r
1217         }\r
1218 \r
1219 #endif\r
1220 \r
1221 \r
1222 \r
1223 /*-----------------------------------------------------------\r
1224  * SCHEDULER INTERNALS AVAILABLE FOR PORTING PURPOSES\r
1225  * documented in task.h\r
1226  *----------------------------------------------------------*/\r
1227 \r
1228 \r
1229 void vTaskIncrementTick( void )\r
1230 {\r
1231         /* Called by the portable layer each time a tick interrupt occurs.\r
1232         Increments the tick then checks to see if the new tick value will cause any\r
1233         tasks to be unblocked. */\r
1234         if( uxSchedulerSuspended == ( unsigned portBASE_TYPE ) pdFALSE )\r
1235         {\r
1236                 ++xTickCount;\r
1237                 if( xTickCount == ( portTickType ) 0 )\r
1238                 {\r
1239                         xList *pxTemp;\r
1240 \r
1241                         /* Tick count has overflowed so we need to swap the delay lists.\r
1242                         If there are any items in pxDelayedTaskList here then there is\r
1243                         an error! */\r
1244                         pxTemp = pxDelayedTaskList;\r
1245                         pxDelayedTaskList = pxOverflowDelayedTaskList;\r
1246                         pxOverflowDelayedTaskList = pxTemp;\r
1247             xNumOfOverflows++;\r
1248                 }\r
1249 \r
1250                 /* See if this tick has made a timeout expire. */\r
1251                 prvCheckDelayedTasks();\r
1252         }\r
1253         else\r
1254         {\r
1255                 ++uxMissedTicks;\r
1256 \r
1257                 /* The tick hook gets called at regular intervals, even if the\r
1258                 scheduler is locked. */\r
1259                 #if ( configUSE_TICK_HOOK == 1 )\r
1260                 {\r
1261                         extern void vApplicationTickHook( void );\r
1262 \r
1263                         vApplicationTickHook();\r
1264                 }\r
1265                 #endif\r
1266         }\r
1267 \r
1268         #if ( configUSE_TICK_HOOK == 1 )\r
1269         {\r
1270                 extern void vApplicationTickHook( void );\r
1271 \r
1272                 /* Guard against the tick hook being called when the missed tick\r
1273                 count is being unwound (when the scheduler is being unlocked. */\r
1274                 if( uxMissedTicks == 0 )\r
1275                 {\r
1276                         vApplicationTickHook();\r
1277                 }\r
1278         }\r
1279         #endif\r
1280 \r
1281         traceTASK_INCREMENT_TICK( xTickCount );\r
1282 }\r
1283 /*-----------------------------------------------------------*/\r
1284 \r
1285 #if ( ( INCLUDE_vTaskCleanUpResources == 1 ) && ( INCLUDE_vTaskSuspend == 1 ) )\r
1286 \r
1287         void vTaskCleanUpResources( void )\r
1288         {\r
1289         unsigned portSHORT usQueue;\r
1290         volatile tskTCB *pxTCB;\r
1291 \r
1292                 usQueue = ( unsigned portSHORT ) uxTopUsedPriority + ( unsigned portSHORT ) 1;\r
1293 \r
1294                 /* Remove any TCB's from the ready queues. */\r
1295                 do\r
1296                 {\r
1297                         usQueue--;\r
1298 \r
1299                         while( !listLIST_IS_EMPTY( &( pxReadyTasksLists[ usQueue ] ) ) )\r
1300                         {\r
1301                                 listGET_OWNER_OF_NEXT_ENTRY( pxTCB, &( pxReadyTasksLists[ usQueue ] ) );\r
1302                                 vListRemove( ( xListItem * ) &( pxTCB->xGenericListItem ) );\r
1303 \r
1304                                 prvDeleteTCB( ( tskTCB * ) pxTCB );\r
1305                         }\r
1306                 }while( usQueue > ( unsigned portSHORT ) tskIDLE_PRIORITY );\r
1307 \r
1308                 /* Remove any TCB's from the delayed queue. */\r
1309                 while( !listLIST_IS_EMPTY( &xDelayedTaskList1 ) )\r
1310                 {\r
1311                         listGET_OWNER_OF_NEXT_ENTRY( pxTCB, &xDelayedTaskList1 );\r
1312                         vListRemove( ( xListItem * ) &( pxTCB->xGenericListItem ) );\r
1313 \r
1314                         prvDeleteTCB( ( tskTCB * ) pxTCB );\r
1315                 }\r
1316 \r
1317                 /* Remove any TCB's from the overflow delayed queue. */\r
1318                 while( !listLIST_IS_EMPTY( &xDelayedTaskList2 ) )\r
1319                 {\r
1320                         listGET_OWNER_OF_NEXT_ENTRY( pxTCB, &xDelayedTaskList2 );\r
1321                         vListRemove( ( xListItem * ) &( pxTCB->xGenericListItem ) );\r
1322 \r
1323                         prvDeleteTCB( ( tskTCB * ) pxTCB );\r
1324                 }\r
1325 \r
1326                 while( !listLIST_IS_EMPTY( &xSuspendedTaskList ) )\r
1327                 {\r
1328                         listGET_OWNER_OF_NEXT_ENTRY( pxTCB, &xSuspendedTaskList );\r
1329                         vListRemove( ( xListItem * ) &( pxTCB->xGenericListItem ) );\r
1330 \r
1331                         prvDeleteTCB( ( tskTCB * ) pxTCB );\r
1332                 }               \r
1333         }\r
1334 \r
1335 #endif\r
1336 /*-----------------------------------------------------------*/\r
1337 \r
1338 #if ( configUSE_APPLICATION_TASK_TAG == 1 )\r
1339 \r
1340         void vTaskSetApplicationTaskTag( xTaskHandle xTask, pdTASK_HOOK_CODE pxTagValue )\r
1341         {\r
1342         tskTCB *xTCB;\r
1343 \r
1344                 /* If xTask is NULL then we are setting our own task hook. */\r
1345                 if( xTask == NULL )\r
1346                 {\r
1347                         xTCB = ( tskTCB * ) pxCurrentTCB;\r
1348                 }\r
1349                 else\r
1350                 {\r
1351                         xTCB = ( tskTCB * ) xTask;\r
1352                 }\r
1353                 \r
1354                 /* Save the hook function in the TCB. */\r
1355                 portENTER_CRITICAL();\r
1356                         xTCB->pxTaskTag = pxTagValue;\r
1357                 portEXIT_CRITICAL();\r
1358         }\r
1359         \r
1360 #endif\r
1361 /*-----------------------------------------------------------*/\r
1362 \r
1363 #if ( configUSE_APPLICATION_TASK_TAG == 1 )\r
1364 \r
1365         portBASE_TYPE xTaskCallApplicationTaskHook( xTaskHandle xTask, void *pvParameter )\r
1366         {\r
1367         tskTCB *xTCB;\r
1368         portBASE_TYPE xReturn;\r
1369 \r
1370                 /* If xTask is NULL then we are calling our own task hook. */\r
1371                 if( xTask == NULL )\r
1372                 {\r
1373                         xTCB = ( tskTCB * ) pxCurrentTCB;\r
1374                 }\r
1375                 else\r
1376                 {\r
1377                         xTCB = ( tskTCB * ) xTask;\r
1378                 }\r
1379 \r
1380                 if( xTCB->pxTaskTag != NULL )\r
1381                 {\r
1382                         xReturn = xTCB->pxTaskTag( pvParameter );\r
1383                 }\r
1384                 else\r
1385                 {\r
1386                         xReturn = pdFAIL;\r
1387                 }\r
1388 \r
1389                 return xReturn;\r
1390         }\r
1391         \r
1392 #endif\r
1393 /*-----------------------------------------------------------*/\r
1394 \r
1395 void vTaskSwitchContext( void )\r
1396 {\r
1397         traceTASK_SWITCHED_OUT();\r
1398 \r
1399         if( uxSchedulerSuspended != ( unsigned portBASE_TYPE ) pdFALSE )\r
1400         {\r
1401                 /* The scheduler is currently suspended - do not allow a context\r
1402                 switch. */\r
1403                 xMissedYield = pdTRUE;\r
1404                 return;\r
1405         }\r
1406 \r
1407         taskFIRST_CHECK_FOR_STACK_OVERFLOW();\r
1408         taskSECOND_CHECK_FOR_STACK_OVERFLOW();\r
1409 \r
1410         /* Find the highest priority queue that contains ready tasks. */\r
1411         while( listLIST_IS_EMPTY( &( pxReadyTasksLists[ uxTopReadyPriority ] ) ) )\r
1412         {\r
1413                 --uxTopReadyPriority;\r
1414         }\r
1415 \r
1416         /* listGET_OWNER_OF_NEXT_ENTRY walks through the list, so the tasks of the\r
1417         same priority get an equal share of the processor time. */\r
1418         listGET_OWNER_OF_NEXT_ENTRY( pxCurrentTCB, &( pxReadyTasksLists[ uxTopReadyPriority ] ) );\r
1419 \r
1420         traceTASK_SWITCHED_IN();\r
1421         vWriteTraceToBuffer();\r
1422 }\r
1423 /*-----------------------------------------------------------*/\r
1424 \r
1425 void vTaskPlaceOnEventList( const xList * const pxEventList, portTickType xTicksToWait )\r
1426 {\r
1427 portTickType xTimeToWake;\r
1428 \r
1429         /* THIS FUNCTION MUST BE CALLED WITH INTERRUPTS DISABLED OR THE\r
1430         SCHEDULER SUSPENDED. */\r
1431 \r
1432         /* Place the event list item of the TCB in the appropriate event list.\r
1433         This is placed in the list in priority order so the highest priority task\r
1434         is the first to be woken by the event. */\r
1435         vListInsert( ( xList * ) pxEventList, ( xListItem * ) &( pxCurrentTCB->xEventListItem ) );\r
1436 \r
1437         /* We must remove ourselves from the ready list before adding ourselves\r
1438         to the blocked list as the same list item is used for both lists.  We have\r
1439         exclusive access to the ready lists as the scheduler is locked. */\r
1440         vListRemove( ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );\r
1441 \r
1442 \r
1443         #if ( INCLUDE_vTaskSuspend == 1 )\r
1444         {                       \r
1445                 if( xTicksToWait == portMAX_DELAY )\r
1446                 {\r
1447                         /* Add ourselves to the suspended task list instead of a delayed task\r
1448                         list to ensure we are not woken by a timing event.  We will block\r
1449                         indefinitely. */\r
1450                         vListInsertEnd( ( xList * ) &xSuspendedTaskList, ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );\r
1451                 }\r
1452                 else\r
1453                 {\r
1454                         /* Calculate the time at which the task should be woken if the event does\r
1455                         not occur.  This may overflow but this doesn't matter. */\r
1456                         xTimeToWake = xTickCount + xTicksToWait;\r
1457                 \r
1458                         listSET_LIST_ITEM_VALUE( &( pxCurrentTCB->xGenericListItem ), xTimeToWake );\r
1459                 \r
1460                         if( xTimeToWake < xTickCount )\r
1461                         {\r
1462                                 /* Wake time has overflowed.  Place this item in the overflow list. */\r
1463                                 vListInsert( ( xList * ) pxOverflowDelayedTaskList, ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );\r
1464                         }\r
1465                         else\r
1466                         {\r
1467                                 /* The wake time has not overflowed, so we can use the current block list. */\r
1468                                 vListInsert( ( xList * ) pxDelayedTaskList, ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );\r
1469                         }\r
1470                 }\r
1471         }\r
1472         #else\r
1473         {\r
1474                         /* Calculate the time at which the task should be woken if the event does\r
1475                         not occur.  This may overflow but this doesn't matter. */\r
1476                         xTimeToWake = xTickCount + xTicksToWait;\r
1477                 \r
1478                         listSET_LIST_ITEM_VALUE( &( pxCurrentTCB->xGenericListItem ), xTimeToWake );\r
1479                 \r
1480                         if( xTimeToWake < xTickCount )\r
1481                         {\r
1482                                 /* Wake time has overflowed.  Place this item in the overflow list. */\r
1483                                 vListInsert( ( xList * ) pxOverflowDelayedTaskList, ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );\r
1484                         }\r
1485                         else\r
1486                         {\r
1487                                 /* The wake time has not overflowed, so we can use the current block list. */\r
1488                                 vListInsert( ( xList * ) pxDelayedTaskList, ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );\r
1489                         }\r
1490         }\r
1491         #endif\r
1492 }\r
1493 /*-----------------------------------------------------------*/\r
1494 \r
1495 signed portBASE_TYPE xTaskRemoveFromEventList( const xList * const pxEventList )\r
1496 {\r
1497 tskTCB *pxUnblockedTCB;\r
1498 portBASE_TYPE xReturn;\r
1499 \r
1500         /* THIS FUNCTION MUST BE CALLED WITH INTERRUPTS DISABLED OR THE\r
1501         SCHEDULER SUSPENDED.  It can also be called from within an ISR. */\r
1502 \r
1503         /* The event list is sorted in priority order, so we can remove the\r
1504         first in the list, remove the TCB from the delayed list, and add\r
1505         it to the ready list.\r
1506         \r
1507         If an event is for a queue that is locked then this function will never\r
1508         get called - the lock count on the queue will get modified instead.  This\r
1509         means we can always expect exclusive access to the event list here. */\r
1510         pxUnblockedTCB = ( tskTCB * ) listGET_OWNER_OF_HEAD_ENTRY( pxEventList );\r
1511         vListRemove( &( pxUnblockedTCB->xEventListItem ) );\r
1512 \r
1513         if( uxSchedulerSuspended == ( unsigned portBASE_TYPE ) pdFALSE )\r
1514         {\r
1515                 vListRemove( &( pxUnblockedTCB->xGenericListItem ) );\r
1516                 prvAddTaskToReadyQueue( pxUnblockedTCB );\r
1517         }\r
1518         else\r
1519         {\r
1520                 /* We cannot access the delayed or ready lists, so will hold this\r
1521                 task pending until the scheduler is resumed. */\r
1522                 vListInsertEnd( ( xList * ) &( xPendingReadyList ), &( pxUnblockedTCB->xEventListItem ) );\r
1523         }\r
1524 \r
1525         if( pxUnblockedTCB->uxPriority >= pxCurrentTCB->uxPriority )\r
1526         {\r
1527                 /* Return true if the task removed from the event list has\r
1528                 a higher priority than the calling task.  This allows\r
1529                 the calling task to know if it should force a context\r
1530                 switch now. */\r
1531                 xReturn = pdTRUE;\r
1532         }\r
1533         else\r
1534         {\r
1535                 xReturn = pdFALSE;\r
1536         }\r
1537 \r
1538         return xReturn;\r
1539 }\r
1540 /*-----------------------------------------------------------*/\r
1541 \r
1542 void vTaskSetTimeOutState( xTimeOutType * const pxTimeOut )\r
1543 {\r
1544     pxTimeOut->xOverflowCount = xNumOfOverflows;\r
1545     pxTimeOut->xTimeOnEntering = xTickCount;\r
1546 }\r
1547 /*-----------------------------------------------------------*/\r
1548 \r
1549 portBASE_TYPE xTaskCheckForTimeOut( xTimeOutType * const pxTimeOut, portTickType * const pxTicksToWait )\r
1550 {\r
1551 portBASE_TYPE xReturn;\r
1552 \r
1553         portENTER_CRITICAL();\r
1554         {\r
1555                 #if ( INCLUDE_vTaskSuspend == 1 )\r
1556                         /* If INCLUDE_vTaskSuspend is set to 1 and the block time specified is\r
1557                         the maximum block time then the task should block indefinitely, and\r
1558                         therefore never time out. */\r
1559                         if( *pxTicksToWait == portMAX_DELAY )\r
1560                         {\r
1561                                 xReturn = pdFALSE;\r
1562                         }\r
1563                         else /* We are not blocking indefinitely, perform the checks below. */\r
1564                 #endif\r
1565 \r
1566                 if( ( xNumOfOverflows != pxTimeOut->xOverflowCount ) && ( xTickCount >= pxTimeOut->xTimeOnEntering ) )\r
1567                 {\r
1568                         /* The tick count is greater than the time at which vTaskSetTimeout()\r
1569                         was called, but has also overflowed since vTaskSetTimeOut() was called.\r
1570                         It must have wrapped all the way around and gone past us again. This\r
1571                         passed since vTaskSetTimeout() was called. */\r
1572                         xReturn = pdTRUE;\r
1573                 }\r
1574                 else if( ( xTickCount - pxTimeOut->xTimeOnEntering ) < *pxTicksToWait )\r
1575                 {\r
1576                         /* Not a genuine timeout. Adjust parameters for time remaining. */\r
1577                         *pxTicksToWait -= ( xTickCount - pxTimeOut->xTimeOnEntering );\r
1578                         vTaskSetTimeOutState( pxTimeOut );\r
1579                         xReturn = pdFALSE;\r
1580                 }\r
1581                 else\r
1582                 {\r
1583                         xReturn = pdTRUE;\r
1584                 }\r
1585         }\r
1586         portEXIT_CRITICAL();\r
1587 \r
1588     return xReturn;\r
1589 }\r
1590 /*-----------------------------------------------------------*/\r
1591 \r
1592 void vTaskMissedYield( void )\r
1593 {\r
1594         xMissedYield = pdTRUE;\r
1595 }\r
1596 \r
1597 /*\r
1598  * -----------------------------------------------------------\r
1599  * The Idle task.\r
1600  * ----------------------------------------------------------\r
1601  *\r
1602  * The portTASK_FUNCTION() macro is used to allow port/compiler specific\r
1603  * language extensions.  The equivalent prototype for this function is:\r
1604  *\r
1605  * void prvIdleTask( void *pvParameters );\r
1606  *\r
1607  */\r
1608 static portTASK_FUNCTION( prvIdleTask, pvParameters )\r
1609 {\r
1610         /* Stop warnings. */\r
1611         ( void ) pvParameters;\r
1612 \r
1613         for( ;; )\r
1614         {\r
1615                 /* See if any tasks have been deleted. */\r
1616                 prvCheckTasksWaitingTermination();\r
1617 \r
1618                 #if ( configUSE_PREEMPTION == 0 )\r
1619                 {\r
1620                         /* If we are not using preemption we keep forcing a task switch to\r
1621                         see if any other task has become available.  If we are using\r
1622                         preemption we don't need to do this as any task becoming available\r
1623                         will automatically get the processor anyway. */\r
1624                         taskYIELD();    \r
1625                 }\r
1626                 #endif\r
1627 \r
1628                 #if ( ( configUSE_PREEMPTION == 1 ) && ( configIDLE_SHOULD_YIELD == 1 ) )\r
1629                 {\r
1630                         /* When using preemption tasks of equal priority will be\r
1631                         timesliced.  If a task that is sharing the idle priority is ready\r
1632                         to run then the idle task should yield before the end of the\r
1633                         timeslice.\r
1634                         \r
1635                         A critical region is not required here as we are just reading from\r
1636                         the list, and an occasional incorrect value will not matter.  If\r
1637                         the ready list at the idle priority contains more than one task\r
1638                         then a task other than the idle task is ready to execute. */\r
1639                         if( listCURRENT_LIST_LENGTH( &( pxReadyTasksLists[ tskIDLE_PRIORITY ] ) ) > ( unsigned portBASE_TYPE ) 1 )\r
1640                         {\r
1641                                 taskYIELD();\r
1642                         }\r
1643                 }\r
1644                 #endif\r
1645 \r
1646                 #if ( configUSE_IDLE_HOOK == 1 )\r
1647                 {\r
1648                         extern void vApplicationIdleHook( void );\r
1649 \r
1650                         /* Call the user defined function from within the idle task.  This\r
1651                         allows the application designer to add background functionality\r
1652                         without the overhead of a separate task.\r
1653                         NOTE: vApplicationIdleHook() MUST NOT, UNDER ANY CIRCUMSTANCES,\r
1654                         CALL A FUNCTION THAT MIGHT BLOCK. */\r
1655                         vApplicationIdleHook();\r
1656                 }\r
1657                 #endif\r
1658         }\r
1659 } /*lint !e715 pvParameters is not accessed but all task functions require the same prototype. */\r
1660 \r
1661 \r
1662 \r
1663 \r
1664 \r
1665 \r
1666 \r
1667 /*-----------------------------------------------------------\r
1668  * File private functions documented at the top of the file.\r
1669  *----------------------------------------------------------*/\r
1670 \r
1671 \r
1672 \r
1673 static void prvInitialiseTCBVariables( tskTCB *pxTCB, const signed portCHAR * const pcName, unsigned portBASE_TYPE uxPriority )\r
1674 {\r
1675         /* Store the function name in the TCB. */\r
1676         strncpy( ( char * ) pxTCB->pcTaskName, ( const char * ) pcName, ( unsigned portSHORT ) configMAX_TASK_NAME_LEN );\r
1677         pxTCB->pcTaskName[ ( unsigned portSHORT ) configMAX_TASK_NAME_LEN - ( unsigned portSHORT ) 1 ] = '\0';\r
1678 \r
1679         /* This is used as an array index so must ensure it's not too large. */\r
1680         if( uxPriority >= configMAX_PRIORITIES )\r
1681         {\r
1682                 uxPriority = configMAX_PRIORITIES - 1;\r
1683         }\r
1684 \r
1685         pxTCB->uxPriority = uxPriority;\r
1686         #if ( configUSE_MUTEXES == 1 )\r
1687         {\r
1688                 pxTCB->uxBasePriority = uxPriority;\r
1689         }\r
1690         #endif\r
1691 \r
1692         vListInitialiseItem( &( pxTCB->xGenericListItem ) );\r
1693         vListInitialiseItem( &( pxTCB->xEventListItem ) );\r
1694 \r
1695         /* Set the pxTCB as a link back from the xListItem.  This is so we can get\r
1696         back to the containing TCB from a generic item in a list. */\r
1697         listSET_LIST_ITEM_OWNER( &( pxTCB->xGenericListItem ), pxTCB );\r
1698 \r
1699         /* Event lists are always in priority order. */\r
1700         listSET_LIST_ITEM_VALUE( &( pxTCB->xEventListItem ), configMAX_PRIORITIES - ( portTickType ) uxPriority );\r
1701         listSET_LIST_ITEM_OWNER( &( pxTCB->xEventListItem ), pxTCB );\r
1702 \r
1703         #if ( portCRITICAL_NESTING_IN_TCB == 1 )\r
1704         {\r
1705                 pxTCB->uxCriticalNesting = ( unsigned portBASE_TYPE ) 0;\r
1706         }\r
1707         #endif\r
1708 \r
1709         #if ( configUSE_APPLICATION_TASK_TAG == 1 )\r
1710         {\r
1711                 pxTCB->pxTaskTag = NULL;\r
1712         }\r
1713         #endif  \r
1714 }\r
1715 /*-----------------------------------------------------------*/\r
1716 \r
1717 static void prvInitialiseTaskLists( void )\r
1718 {\r
1719 unsigned portBASE_TYPE uxPriority;\r
1720 \r
1721         for( uxPriority = 0; uxPriority < configMAX_PRIORITIES; uxPriority++ )\r
1722         {\r
1723                 vListInitialise( ( xList * ) &( pxReadyTasksLists[ uxPriority ] ) );\r
1724         }\r
1725 \r
1726         vListInitialise( ( xList * ) &xDelayedTaskList1 );\r
1727         vListInitialise( ( xList * ) &xDelayedTaskList2 );\r
1728         vListInitialise( ( xList * ) &xPendingReadyList );\r
1729 \r
1730         #if ( INCLUDE_vTaskDelete == 1 )\r
1731         {\r
1732                 vListInitialise( ( xList * ) &xTasksWaitingTermination );\r
1733         }\r
1734         #endif\r
1735 \r
1736         #if ( INCLUDE_vTaskSuspend == 1 )\r
1737         {\r
1738                 vListInitialise( ( xList * ) &xSuspendedTaskList );\r
1739         }\r
1740         #endif\r
1741 \r
1742         /* Start with pxDelayedTaskList using list1 and the pxOverflowDelayedTaskList\r
1743         using list2. */\r
1744         pxDelayedTaskList = &xDelayedTaskList1;\r
1745         pxOverflowDelayedTaskList = &xDelayedTaskList2;\r
1746 }\r
1747 /*-----------------------------------------------------------*/\r
1748 \r
1749 static void prvCheckTasksWaitingTermination( void )\r
1750 {                                                       \r
1751         #if ( INCLUDE_vTaskDelete == 1 )\r
1752         {                               \r
1753                 portBASE_TYPE xListIsEmpty;\r
1754 \r
1755                 /* ucTasksDeleted is used to prevent vTaskSuspendAll() being called\r
1756                 too often in the idle task. */\r
1757                 if( uxTasksDeleted > ( unsigned portBASE_TYPE ) 0 )\r
1758                 {\r
1759                         vTaskSuspendAll();\r
1760                                 xListIsEmpty = listLIST_IS_EMPTY( &xTasksWaitingTermination );                          \r
1761                         xTaskResumeAll();\r
1762 \r
1763                         if( !xListIsEmpty )\r
1764                         {\r
1765                                 tskTCB *pxTCB;\r
1766 \r
1767                                 portENTER_CRITICAL();\r
1768                                 {                       \r
1769                                         pxTCB = ( tskTCB * ) listGET_OWNER_OF_HEAD_ENTRY( ( ( xList * ) &xTasksWaitingTermination ) );\r
1770                                         vListRemove( &( pxTCB->xGenericListItem ) );\r
1771                                         --uxCurrentNumberOfTasks;\r
1772                                         --uxTasksDeleted;\r
1773                                 }\r
1774                                 portEXIT_CRITICAL();\r
1775 \r
1776                                 prvDeleteTCB( pxTCB );\r
1777                         }\r
1778                 }\r
1779         }\r
1780         #endif\r
1781 }\r
1782 /*-----------------------------------------------------------*/\r
1783 \r
1784 static tskTCB *prvAllocateTCBAndStack( unsigned portSHORT usStackDepth )\r
1785 {\r
1786 tskTCB *pxNewTCB;\r
1787 \r
1788         /* Allocate space for the TCB.  Where the memory comes from depends on\r
1789         the implementation of the port malloc function. */\r
1790         pxNewTCB = ( tskTCB * ) pvPortMalloc( sizeof( tskTCB ) );\r
1791 \r
1792         if( pxNewTCB != NULL )\r
1793         {\r
1794                 /* Allocate space for the stack used by the task being created.\r
1795                 The base of the stack memory stored in the TCB so the task can\r
1796                 be deleted later if required. */\r
1797                 pxNewTCB->pxStack = ( portSTACK_TYPE * ) pvPortMalloc( ( ( size_t )usStackDepth ) * sizeof( portSTACK_TYPE ) );\r
1798 \r
1799                 if( pxNewTCB->pxStack == NULL )\r
1800                 {\r
1801                         /* Could not allocate the stack.  Delete the allocated TCB. */\r
1802                         vPortFree( pxNewTCB );                  \r
1803                         pxNewTCB = NULL;                        \r
1804                 }               \r
1805                 else\r
1806                 {\r
1807                         /* Just to help debugging. */\r
1808                         memset( pxNewTCB->pxStack, tskSTACK_FILL_BYTE, usStackDepth * sizeof( portSTACK_TYPE ) );\r
1809                 }\r
1810         }\r
1811 \r
1812         return pxNewTCB;\r
1813 }\r
1814 /*-----------------------------------------------------------*/\r
1815 \r
1816 #if ( configUSE_TRACE_FACILITY == 1 )\r
1817 \r
1818         static void prvListTaskWithinSingleList( const signed portCHAR *pcWriteBuffer, xList *pxList, signed portCHAR cStatus )\r
1819         {\r
1820         volatile tskTCB *pxNextTCB, *pxFirstTCB;\r
1821         unsigned portSHORT usStackRemaining;\r
1822 \r
1823                 /* Write the details of all the TCB's in pxList into the buffer. */\r
1824                 listGET_OWNER_OF_NEXT_ENTRY( pxFirstTCB, pxList );\r
1825                 do\r
1826                 {\r
1827                         listGET_OWNER_OF_NEXT_ENTRY( pxNextTCB, pxList );\r
1828                         usStackRemaining = usTaskCheckFreeStackSpace( ( unsigned portCHAR * ) pxNextTCB->pxStack );\r
1829                         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
1830                         strcat( ( portCHAR * ) pcWriteBuffer, ( portCHAR * ) pcStatusString );\r
1831 \r
1832                 } while( pxNextTCB != pxFirstTCB );\r
1833         }\r
1834 \r
1835 #endif\r
1836 /*-----------------------------------------------------------*/\r
1837 \r
1838 #if ( ( configUSE_TRACE_FACILITY == 1 ) || ( INCLUDE_uxTaskGetStackHighWaterMark == 1 ) )\r
1839 \r
1840         unsigned portSHORT usTaskCheckFreeStackSpace( const unsigned portCHAR * pucStackByte )\r
1841         {\r
1842         register unsigned portSHORT usCount = 0;\r
1843 \r
1844                 while( *pucStackByte == tskSTACK_FILL_BYTE )\r
1845                 {\r
1846                         pucStackByte -= portSTACK_GROWTH;\r
1847                         usCount++;\r
1848                 }\r
1849 \r
1850                 usCount /= sizeof( portSTACK_TYPE );\r
1851 \r
1852                 return usCount;\r
1853         }\r
1854 \r
1855 #endif\r
1856 /*-----------------------------------------------------------*/\r
1857 \r
1858 #if ( INCLUDE_uxTaskGetStackHighWaterMark == 1 )\r
1859 \r
1860         unsigned portBASE_TYPE uxTaskGetStackHighWaterMark( xTaskHandle xTask )\r
1861         {\r
1862         tskTCB *pxTCB;\r
1863         unsigned portCHAR *pcEndOfStack;\r
1864 \r
1865                 pxTCB = prvGetTCBFromHandle( xTask );\r
1866 \r
1867                 #if portSTACK_GROWTH < 0\r
1868                 {\r
1869                         pcEndOfStack = ( unsigned portCHAR * ) pxTCB->pxStack;\r
1870                 }\r
1871                 #else\r
1872                 {\r
1873                         pcEndOfStack = ( unsigned portCHAR * ) pxTCB->pxEndOfStack;\r
1874                 }\r
1875                 #endif\r
1876 \r
1877                 return usTaskCheckFreeStackSpace( pcEndOfStack );\r
1878         }\r
1879 \r
1880 #endif\r
1881 /*-----------------------------------------------------------*/\r
1882 \r
1883 #if ( ( INCLUDE_vTaskDelete == 1 ) || ( INCLUDE_vTaskCleanUpResources == 1 ) )\r
1884 \r
1885         static void prvDeleteTCB( tskTCB *pxTCB )\r
1886         {\r
1887                 /* Free up the memory allocated by the scheduler for the task.  It is up to\r
1888                 the task to free any memory allocated at the application level. */\r
1889                 vPortFree( pxTCB->pxStack );\r
1890                 vPortFree( pxTCB );\r
1891         }\r
1892 \r
1893 #endif\r
1894 \r
1895 \r
1896 /*-----------------------------------------------------------*/\r
1897 \r
1898 #if ( INCLUDE_xTaskGetCurrentTaskHandle == 1 )\r
1899 \r
1900         xTaskHandle xTaskGetCurrentTaskHandle( void )\r
1901         {\r
1902         xTaskHandle xReturn;\r
1903 \r
1904                 portENTER_CRITICAL();\r
1905                 {\r
1906                         xReturn = ( xTaskHandle ) pxCurrentTCB;\r
1907                 }\r
1908                 portEXIT_CRITICAL();\r
1909 \r
1910                 return xReturn;\r
1911         }\r
1912 \r
1913 #endif\r
1914 \r
1915 /*-----------------------------------------------------------*/\r
1916 \r
1917 #if ( INCLUDE_xTaskGetSchedulerState == 1 )\r
1918 \r
1919         portBASE_TYPE xTaskGetSchedulerState( void )\r
1920         {\r
1921         portBASE_TYPE xReturn;\r
1922         \r
1923                 if( xSchedulerRunning == pdFALSE )\r
1924                 {\r
1925                         xReturn = taskSCHEDULER_NOT_STARTED;\r
1926                 }\r
1927                 else\r
1928                 {\r
1929                         if( uxSchedulerSuspended == ( unsigned portBASE_TYPE ) pdFALSE )\r
1930                         {\r
1931                                 xReturn = taskSCHEDULER_RUNNING;\r
1932                         }\r
1933                         else\r
1934                         {\r
1935                                 xReturn = taskSCHEDULER_SUSPENDED;\r
1936                         }\r
1937                 }\r
1938                 \r
1939                 return xReturn;\r
1940         }\r
1941 \r
1942 #endif\r
1943 /*-----------------------------------------------------------*/\r
1944 \r
1945 #if ( configUSE_MUTEXES == 1 )\r
1946         \r
1947         void vTaskPriorityInherit( xTaskHandle * const pxMutexHolder )\r
1948         {\r
1949         tskTCB * const pxTCB = ( tskTCB * ) pxMutexHolder;\r
1950 \r
1951                 if( pxTCB->uxPriority < pxCurrentTCB->uxPriority )\r
1952                 {\r
1953                         /* Adjust the mutex holder state to account for its new priority. */\r
1954                         listSET_LIST_ITEM_VALUE( &( pxTCB->xEventListItem ), configMAX_PRIORITIES - ( portTickType ) pxCurrentTCB->uxPriority );\r
1955 \r
1956                         /* If the task being modified is in the ready state it will need to\r
1957                         be moved in to a new list. */\r
1958                         if( listIS_CONTAINED_WITHIN( &( pxReadyTasksLists[ pxTCB->uxPriority ] ), &( pxTCB->xGenericListItem ) ) )\r
1959                         {\r
1960                                 vListRemove( &( pxTCB->xGenericListItem ) );\r
1961 \r
1962                                 /* Inherit the priority before being moved into the new list. */\r
1963                                 pxTCB->uxPriority = pxCurrentTCB->uxPriority;\r
1964                                 prvAddTaskToReadyQueue( pxTCB );\r
1965                         }\r
1966                         else\r
1967                         {\r
1968                                 /* Just inherit the priority. */\r
1969                                 pxTCB->uxPriority = pxCurrentTCB->uxPriority;\r
1970                         }\r
1971                 }\r
1972         }\r
1973 \r
1974 #endif\r
1975 /*-----------------------------------------------------------*/\r
1976 \r
1977 #if ( configUSE_MUTEXES == 1 )  \r
1978 \r
1979         void vTaskPriorityDisinherit( xTaskHandle * const pxMutexHolder )\r
1980         {\r
1981         tskTCB * const pxTCB = ( tskTCB * ) pxMutexHolder;\r
1982 \r
1983                 if( pxMutexHolder != NULL )\r
1984                 {\r
1985                         if( pxTCB->uxPriority != pxTCB->uxBasePriority )\r
1986                         {\r
1987                                 /* We must be the running task to be able to give the mutex back.\r
1988                                 Remove ourselves from the ready list we currently appear in. */\r
1989                                 vListRemove( &( pxTCB->xGenericListItem ) );\r
1990 \r
1991                                 /* Disinherit the priority before adding ourselves into the new\r
1992                                 ready list. */\r
1993                                 pxTCB->uxPriority = pxTCB->uxBasePriority;\r
1994                                 listSET_LIST_ITEM_VALUE( &( pxTCB->xEventListItem ), configMAX_PRIORITIES - ( portTickType ) pxTCB->uxPriority );\r
1995                                 prvAddTaskToReadyQueue( pxTCB );\r
1996                         }\r
1997                 }\r
1998         }\r
1999 \r
2000 #endif\r
2001 /*-----------------------------------------------------------*/\r
2002 \r
2003 #if ( portCRITICAL_NESTING_IN_TCB == 1 )\r
2004 \r
2005         void vTaskEnterCritical( void )\r
2006         {\r
2007                 portDISABLE_INTERRUPTS();\r
2008 \r
2009                 if( xSchedulerRunning != pdFALSE )\r
2010                 {\r
2011                         pxCurrentTCB->uxCriticalNesting++;\r
2012                 }\r
2013         }\r
2014 \r
2015 #endif\r
2016 /*-----------------------------------------------------------*/\r
2017 \r
2018 #if ( portCRITICAL_NESTING_IN_TCB == 1 )\r
2019 \r
2020 void vTaskExitCritical( void )\r
2021 {\r
2022         if( xSchedulerRunning != pdFALSE )\r
2023         {\r
2024                 if( pxCurrentTCB->uxCriticalNesting > 0 )\r
2025                 {\r
2026                         pxCurrentTCB->uxCriticalNesting--;\r
2027 \r
2028                         if( pxCurrentTCB->uxCriticalNesting == 0 )\r
2029                         {\r
2030                                 portENABLE_INTERRUPTS();\r
2031                         }\r
2032                 }\r
2033         }\r
2034 }\r
2035 \r
2036 #endif\r
2037 /*-----------------------------------------------------------*/\r
2038 \r
2039 \r
2040         \r
2041 \r