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

   1 /*\r
   2         FreeRTOS.org V5.1.0 - Copyright (C) 2003-2008 Richard Barry.\r
   3 \r
   4         This file is part of the FreeRTOS.org distribution.\r
   5 \r
   6         FreeRTOS.org is free software; you can redistribute it and/or modify\r
   7         it under the terms of the GNU General Public License as published by\r
   8         the Free Software Foundation; either version 2 of the License, or\r
   9         (at your option) any later version.\r
  10 \r
  11         FreeRTOS.org is distributed in the hope that it will be useful,\r
  12         but WITHOUT ANY WARRANTY; without even the implied warranty of\r
  13         MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the\r
  14         GNU General Public License for more details.\r
  15 \r
  16         You should have received a copy of the GNU General Public License\r
  17         along with FreeRTOS.org; if not, write to the Free Software\r
  18         Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA\r
  19 \r
  20         A special exception to the GPL can be applied should you wish to distribute\r
  21         a combined work that includes FreeRTOS.org, without being obliged to provide\r
  22         the source code for any proprietary components.  See the licensing section\r
  23         of http://www.FreeRTOS.org for full details of how and when the exception\r
  24         can be applied.\r
  25 \r
  26     ***************************************************************************\r
  27     ***************************************************************************\r
  28     *                                                                         *\r
  29     * SAVE TIME AND MONEY!  We can port FreeRTOS.org to your own hardware,    *\r
  30     * and even write all or part of your application on your behalf.          *\r
  31     * See http://www.OpenRTOS.com for details of the services we provide to   *\r
  32     * expedite your project.                                                  *\r
  33     *                                                                         *\r
  34     ***************************************************************************\r
  35     ***************************************************************************\r
  36 \r
  37         Please ensure to read the configuration and relevant port sections of the\r
  38         online documentation.\r
  39 \r
  40         http://www.FreeRTOS.org - Documentation, latest information, license and \r
  41         contact details.\r
  42 \r
  43         http://www.SafeRTOS.com - A version that is certified for use in safety \r
  44         critical systems.\r
  45 \r
  46         http://www.OpenRTOS.com - Commercial support, development, porting, \r
  47         licensing and training services.\r
  48 */\r
  49 \r
  50 \r
  51 #include <stdio.h>\r
  52 #include <stdlib.h>\r
  53 #include <string.h>\r
  54 \r
  55 #include "FreeRTOS.h"\r
  56 #include "task.h"\r
  57 #include "StackMacros.h"\r
  58 \r
  59 /*\r
  60  * Macro to define the amount of stack available to the idle task.\r
  61  */\r
  62 #define tskIDLE_STACK_SIZE      configMINIMAL_STACK_SIZE\r
  63 \r
  64 /*\r
  65  * Task control block.  A task control block (TCB) is allocated to each task,\r
  66  * and stores the context of the task.\r
  67  */\r
  68 typedef struct tskTaskControlBlock\r
  69 {\r
  70         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
  71         xListItem                               xGenericListItem;       /*< List item used to place the TCB in ready and blocked queues. */\r
  72         xListItem                               xEventListItem;         /*< List item used to place the TCB in event lists. */\r
  73         unsigned portBASE_TYPE  uxPriority;                     /*< The priority of the task where 0 is the lowest priority. */\r
  74         portSTACK_TYPE                  *pxStack;                       /*< Points to the start of the stack. */\r
  75         signed portCHAR                 pcTaskName[ configMAX_TASK_NAME_LEN ];/*< Descriptive name given to the task when created.  Facilitates debugging only. */\r
  76 \r
  77         #if ( portSTACK_GROWTH > 0 )\r
  78                 portSTACK_TYPE *pxEndOfStack;                   /*< Used for stack overflow checking on architectures where the stack grows up from low memory. */\r
  79         #endif\r
  80 \r
  81         #if ( portCRITICAL_NESTING_IN_TCB == 1 )\r
  82                 unsigned portBASE_TYPE uxCriticalNesting;\r
  83         #endif\r
  84 \r
  85         #if ( configUSE_TRACE_FACILITY == 1 )\r
  86                 unsigned portBASE_TYPE  uxTCBNumber;            /*< This is used for tracing the scheduler and making debugging easier only. */\r
  87         #endif  \r
  88                 \r
  89         #if ( configUSE_MUTEXES == 1 )\r
  90                 unsigned portBASE_TYPE uxBasePriority;\r
  91         #endif\r
  92 \r
  93         #if ( configUSE_APPLICATION_TASK_TAG == 1 )\r
  94                 pdTASK_HOOK_CODE pxTaskTag;\r
  95         #endif\r
  96                 \r
  97 } tskTCB;\r
  98 \r
  99 /*\r
 100  * Some kernel aware debuggers require data to be viewed to be global, rather\r
 101  * than file scope.\r
 102  */\r
 103 #ifdef portREMOVE_STATIC_QUALIFIER\r
 104         #define static\r
 105 #endif\r
 106 \r
 107 /*lint -e956 */\r
 108 \r
 109 tskTCB * volatile pxCurrentTCB = NULL;                                  \r
 110 \r
 111 /* Lists for ready and blocked tasks. --------------------*/\r
 112 \r
 113 static xList pxReadyTasksLists[ configMAX_PRIORITIES ]; /*< Prioritised ready tasks. */\r
 114 static xList xDelayedTaskList1;                                                 /*< Delayed tasks. */\r
 115 static xList xDelayedTaskList2;                                                 /*< Delayed tasks (two lists are used - one for delays that have overflowed the current tick count. */\r
 116 static xList * volatile pxDelayedTaskList;                              /*< Points to the delayed task list currently being used. */\r
 117 static xList * volatile pxOverflowDelayedTaskList;              /*< Points to the delayed task list currently being used to hold tasks that have overflowed the current tick count. */\r
 118 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
 119 \r
 120 #if ( INCLUDE_vTaskDelete == 1 )\r
 121 \r
 122         static volatile xList xTasksWaitingTermination;         /*< Tasks that have been deleted - but the their memory not yet freed. */\r
 123         static volatile unsigned portBASE_TYPE uxTasksDeleted = ( unsigned portBASE_TYPE ) 0;\r
 124 \r
 125 #endif\r
 126 \r
 127 #if ( INCLUDE_vTaskSuspend == 1 )\r
 128 \r
 129         static xList xSuspendedTaskList;                                        /*< Tasks that are currently suspended. */\r
 130 \r
 131 #endif\r
 132 \r
 133 /* File private variables. --------------------------------*/\r
 134 static volatile unsigned portBASE_TYPE uxCurrentNumberOfTasks   = ( unsigned portBASE_TYPE ) 0;\r
 135 static volatile portTickType xTickCount                                                 = ( portTickType ) 0;\r
 136 static unsigned portBASE_TYPE uxTopUsedPriority                                 = tskIDLE_PRIORITY;\r
 137 static volatile unsigned portBASE_TYPE uxTopReadyPriority               = tskIDLE_PRIORITY;\r
 138 static volatile signed portBASE_TYPE xSchedulerRunning                  = pdFALSE;\r
 139 static volatile unsigned portBASE_TYPE uxSchedulerSuspended             = ( unsigned portBASE_TYPE ) pdFALSE;\r
 140 static volatile unsigned portBASE_TYPE uxMissedTicks                    = ( unsigned portBASE_TYPE ) 0;\r
 141 static volatile portBASE_TYPE xMissedYield                                              = ( portBASE_TYPE ) pdFALSE;\r
 142 static volatile portBASE_TYPE xNumOfOverflows                                   = ( portBASE_TYPE ) 0;\r
 143 #if ( configUSE_TRACE_FACILITY == 1 )\r
 144         static unsigned portBASE_TYPE uxTaskNumber = 0; /*lint !e956 Static is deliberate - this is guarded before use. */\r
 145 #endif\r
 146 \r
 147 /* Debugging and trace facilities private variables and macros. ------------*/\r
 148 \r
 149 /*\r
 150  * The value used to fill the stack of a task when the task is created.  This\r
 151  * is used purely for checking the high water mark for tasks.\r
 152  */\r
 153 #define tskSTACK_FILL_BYTE      ( 0xa5 )\r
 154 \r
 155 /*\r
 156  * Macros used by vListTask to indicate which state a task is in.\r
 157  */\r
 158 #define tskBLOCKED_CHAR         ( ( signed portCHAR ) 'B' )\r
 159 #define tskREADY_CHAR           ( ( signed portCHAR ) 'R' )\r
 160 #define tskDELETED_CHAR         ( ( signed portCHAR ) 'D' )\r
 161 #define tskSUSPENDED_CHAR       ( ( signed portCHAR ) 'S' )\r
 162 \r
 163 /*\r
 164  * Macros and private variables used by the trace facility.\r
 165  */\r
 166 #if ( configUSE_TRACE_FACILITY == 1 )\r
 167 \r
 168         #define tskSIZE_OF_EACH_TRACE_LINE                      ( ( unsigned portLONG ) ( sizeof( unsigned portLONG ) + sizeof( unsigned portLONG ) ) )\r
 169         static volatile signed portCHAR * volatile pcTraceBuffer;\r
 170         static signed portCHAR *pcTraceBufferStart;\r
 171         static signed portCHAR *pcTraceBufferEnd;\r
 172         static signed portBASE_TYPE xTracing = pdFALSE;\r
 173         static unsigned portBASE_TYPE uxPreviousTask = 255;\r
 174         static portCHAR pcStatusString[ 50 ];\r
 175 #endif\r
 176 \r
 177 /*-----------------------------------------------------------*/\r
 178 \r
 179 /*\r
 180  * Macro that writes a trace of scheduler activity to a buffer.  This trace\r
 181  * shows which task is running when and is very useful as a debugging tool.\r
 182  * As this macro is called each context switch it is a good idea to undefine\r
 183  * it if not using the facility.\r
 184  */\r
 185 #if ( configUSE_TRACE_FACILITY == 1 )\r
 186 \r
 187         #define vWriteTraceToBuffer()                                                                                                                                   \\r
 188         {                                                                                                                                                                                               \\r
 189                 if( xTracing )                                                                                                                                                          \\r
 190                 {                                                                                                                                                                                       \\r
 191                         if( uxPreviousTask != pxCurrentTCB->uxTCBNumber )                                                                               \\r
 192                         {                                                                                                                                                                               \\r
 193                                 if( ( pcTraceBuffer + tskSIZE_OF_EACH_TRACE_LINE ) < pcTraceBufferEnd )                         \\r
 194                                 {                                                                                                                                                                       \\r
 195                                         uxPreviousTask = pxCurrentTCB->uxTCBNumber;                                                                             \\r
 196                                         *( unsigned portLONG * ) pcTraceBuffer = ( unsigned portLONG ) xTickCount;              \\r
 197                                         pcTraceBuffer += sizeof( unsigned portLONG );                                                                   \\r
 198                                         *( unsigned portLONG * ) pcTraceBuffer = ( unsigned portLONG ) uxPreviousTask;  \\r
 199                                         pcTraceBuffer += sizeof( unsigned portLONG );                                                                   \\r
 200                                 }                                                                                                                                                                       \\r
 201                                 else                                                                                                                                                            \\r
 202                                 {                                                                                                                                                                       \\r
 203                                         xTracing = pdFALSE;                                                                                                                             \\r
 204                                 }                                                                                                                                                                       \\r
 205                         }                                                                                                                                                                               \\r
 206                 }                                                                                                                                                                                       \\r
 207         }\r
 208 \r
 209 #else\r
 210 \r
 211         #define vWriteTraceToBuffer()\r
 212 \r
 213 #endif\r
 214 /*-----------------------------------------------------------*/\r
 215 \r
 216 /*\r
 217  * Place the task represented by pxTCB into the appropriate ready queue for\r
 218  * the task.  It is inserted at the end of the list.  One quirk of this is\r
 219  * that if the task being inserted is at the same priority as the currently\r
 220  * executing task, then it will only be rescheduled after the currently\r
 221  * executing task has been rescheduled.\r
 222  */\r
 223 #define prvAddTaskToReadyQueue( pxTCB )                                                                                                                                                 \\r
 224 {                                                                                                                                                                                                                               \\r
 225         if( pxTCB->uxPriority > uxTopReadyPriority )                                                                                                                            \\r
 226         {                                                                                                                                                                                                                       \\r
 227                 uxTopReadyPriority = pxTCB->uxPriority;                                                                                                                                 \\r
 228         }                                                                                                                                                                                                                       \\r
 229         vListInsertEnd( ( xList * ) &( pxReadyTasksLists[ pxTCB->uxPriority ] ), &( pxTCB->xGenericListItem ) );        \\r
 230 }\r
 231 /*-----------------------------------------------------------*/         \r
 232 \r
 233 /*\r
 234  * Macro that looks at the list of tasks that are currently delayed to see if\r
 235  * any require waking.\r
 236  *\r
 237  * Tasks are stored in the queue in the order of their wake time - meaning\r
 238  * once one tasks has been found whose timer has not expired we need not look\r
 239  * any further down the list.\r
 240  */\r
 241 #define prvCheckDelayedTasks()                                                                                                                                                                          \\r
 242 {                                                                                                                                                                                                                                       \\r
 243 register tskTCB *pxTCB;                                                                                                                                                                                         \\r
 244                                                                                                                                                                                                                                         \\r
 245         while( ( pxTCB = ( tskTCB * ) listGET_OWNER_OF_HEAD_ENTRY( pxDelayedTaskList ) ) != NULL )                                              \\r
 246         {                                                                                                                                                                                                                               \\r
 247                 if( xTickCount < listGET_LIST_ITEM_VALUE( &( pxTCB->xGenericListItem ) ) )                                                                      \\r
 248                 {                                                                                                                                                                                                                       \\r
 249                         break;                                                                                                                                                                                                  \\r
 250                 }                                                                                                                                                                                                                       \\r
 251                 vListRemove( &( pxTCB->xGenericListItem ) );                                                                                                                            \\r
 252                 /* Is the task waiting on an event also? */                                                                                                                                     \\r
 253                 if( pxTCB->xEventListItem.pvContainer )                                                                                                                                         \\r
 254                 {                                                                                                                                                                                                                       \\r
 255                         vListRemove( &( pxTCB->xEventListItem ) );                                                                                                                              \\r
 256                 }                                                                                                                                                                                                                       \\r
 257                 prvAddTaskToReadyQueue( pxTCB );                                                                                                                                                        \\r
 258         }                                                                                                                                                                                                                               \\r
 259 }\r
 260 /*-----------------------------------------------------------*/\r
 261 \r
 262 /*\r
 263  * Several functions take an xTaskHandle parameter that can optionally be NULL,\r
 264  * where NULL is used to indicate that the handle of the currently executing\r
 265  * task should be used in place of the parameter.  This macro simply checks to\r
 266  * see if the parameter is NULL and returns a pointer to the appropriate TCB.\r
 267  */\r
 268 #define prvGetTCBFromHandle( pxHandle ) ( ( pxHandle == NULL ) ? ( tskTCB * ) pxCurrentTCB : ( tskTCB * ) pxHandle )\r
 269 \r
 270 \r
 271 /* File private functions. --------------------------------*/\r
 272 \r
 273 /*\r
 274  * Utility to ready a TCB for a given task.  Mainly just copies the parameters\r
 275  * into the TCB structure.\r
 276  */\r
 277 static void prvInitialiseTCBVariables( tskTCB *pxTCB, const signed portCHAR * const pcName, unsigned portBASE_TYPE uxPriority );\r
 278 \r
 279 /*\r
 280  * Utility to ready all the lists used by the scheduler.  This is called\r
 281  * automatically upon the creation of the first task.\r
 282  */\r
 283 static void prvInitialiseTaskLists( void );\r
 284 \r
 285 /*\r
 286  * The idle task, which as all tasks is implemented as a never ending loop.\r
 287  * The idle task is automatically created and added to the ready lists upon\r
 288  * creation of the first user task.\r
 289  *\r
 290  * The portTASK_FUNCTION_PROTO() macro is used to allow port/compiler specific\r
 291  * language extensions.  The equivalent prototype for this function is:\r
 292  *\r
 293  * void prvIdleTask( void *pvParameters );\r
 294  *\r
 295  */\r
 296 static portTASK_FUNCTION_PROTO( prvIdleTask, pvParameters );\r
 297 \r
 298 /*\r
 299  * Utility to free all memory allocated by the scheduler to hold a TCB,\r
 300  * including the stack pointed to by the TCB.\r
 301  *\r
 302  * This does not free memory allocated by the task itself (i.e. memory\r
 303  * allocated by calls to pvPortMalloc from within the tasks application code).\r
 304  */\r
 305 #if ( ( INCLUDE_vTaskDelete == 1 ) || ( INCLUDE_vTaskCleanUpResources == 1 ) )\r
 306         static void prvDeleteTCB( tskTCB *pxTCB );\r
 307 #endif\r
 308 \r
 309 /*\r
 310  * Used only by the idle task.  This checks to see if anything has been placed\r
 311  * in the list of tasks waiting to be deleted.  If so the task is cleaned up\r
 312  * and its TCB deleted.\r
 313  */\r
 314 static void prvCheckTasksWaitingTermination( void );\r
 315 \r
 316 /*\r
 317  * Allocates memory from the heap for a TCB and associated stack.  Checks the\r
 318  * allocation was successful.\r
 319  */\r
 320 static tskTCB *prvAllocateTCBAndStack( unsigned portSHORT usStackDepth );\r
 321 \r
 322 /*\r
 323  * Called from vTaskList.  vListTasks details all the tasks currently under\r
 324  * control of the scheduler.  The tasks may be in one of a number of lists.\r
 325  * prvListTaskWithinSingleList accepts a list and details the tasks from\r
 326  * within just that list.\r
 327  *\r
 328  * THIS FUNCTION IS INTENDED FOR DEBUGGING ONLY, AND SHOULD NOT BE CALLED FROM\r
 329  * NORMAL APPLICATION CODE.\r
 330  */\r
 331 #if ( configUSE_TRACE_FACILITY == 1 )\r
 332 \r
 333         static void prvListTaskWithinSingleList( const signed portCHAR *pcWriteBuffer, xList *pxList, signed portCHAR cStatus );\r
 334 \r
 335 #endif\r
 336 \r
 337 /*\r
 338  * When a task is created, the stack of the task is filled with a known value.\r
 339  * This function determines the 'high water mark' of the task stack by\r
 340  * determining how much of the stack remains at the original preset value.\r
 341  */\r
 342 #if ( ( configUSE_TRACE_FACILITY == 1 ) || ( INCLUDE_uxTaskGetStackHighWaterMark == 1 ) )\r
 343 \r
 344         unsigned portSHORT usTaskCheckFreeStackSpace( const unsigned portCHAR * pucStackByte );\r
 345 \r
 346 #endif\r
 347 \r
 348 \r
 349 /*lint +e956 */\r
 350 \r
 351 \r
 352 \r
 353 /*-----------------------------------------------------------\r
 354  * TASK CREATION API documented in task.h\r
 355  *----------------------------------------------------------*/\r
 356 \r
 357 signed portBASE_TYPE xTaskCreate( pdTASK_CODE pvTaskCode, const signed portCHAR * const pcName, unsigned portSHORT usStackDepth, void *pvParameters, unsigned portBASE_TYPE uxPriority, xTaskHandle *pxCreatedTask )\r
 358 {\r
 359 signed portBASE_TYPE xReturn;\r
 360 tskTCB * pxNewTCB;\r
 361 \r
 362         /* Allocate the memory required by the TCB and stack for the new task.\r
 363         checking that the allocation was successful. */\r
 364         pxNewTCB = prvAllocateTCBAndStack( usStackDepth );\r
 365 \r
 366         if( pxNewTCB != NULL )\r
 367         {               \r
 368                 portSTACK_TYPE *pxTopOfStack;\r
 369 \r
 370                 /* Setup the newly allocated TCB with the initial state of the task. */\r
 371                 prvInitialiseTCBVariables( pxNewTCB, pcName, uxPriority );\r
 372 \r
 373                 /* Calculate the top of stack address.  This depends on whether the\r
 374                 stack grows from high memory to low (as per the 80x86) or visa versa.\r
 375                 portSTACK_GROWTH is used to make the result positive or negative as\r
 376                 required by the port. */\r
 377                 #if portSTACK_GROWTH < 0\r
 378                 {\r
 379                         pxTopOfStack = pxNewTCB->pxStack + ( usStackDepth - 1 );\r
 380                 }\r
 381                 #else\r
 382                 {\r
 383                         pxTopOfStack = pxNewTCB->pxStack;       \r
 384 \r
 385                         /* If we want to use stack checking on architectures that use\r
 386                         a positive stack growth direction then we also need to store the\r
 387                         other extreme of the stack space. */\r
 388                         pxNewTCB->pxEndOfStack = pxNewTCB->pxStack + ( usStackDepth - 1 );\r
 389                 }\r
 390                 #endif\r
 391 \r
 392                 /* Initialize the TCB stack to look as if the task was already running,\r
 393                 but had been interrupted by the scheduler.  The return address is set\r
 394                 to the start of the task function. Once the stack has been initialised\r
 395                 the     top of stack variable is updated. */\r
 396                 pxNewTCB->pxTopOfStack = pxPortInitialiseStack( pxTopOfStack, pvTaskCode, pvParameters );\r
 397 \r
 398                 /* We are going to manipulate the task queues to add this task to a\r
 399                 ready list, so must make sure no interrupts occur. */\r
 400                 portENTER_CRITICAL();\r
 401                 {\r
 402                         uxCurrentNumberOfTasks++;\r
 403                         if( uxCurrentNumberOfTasks == ( unsigned portBASE_TYPE ) 1 )\r
 404                         {\r
 405                                 /* As this is the first task it must also be the current task. */\r
 406                                 pxCurrentTCB =  pxNewTCB;\r
 407 \r
 408                                 /* This is the first task to be created so do the preliminary\r
 409                                 initialisation required.  We will not recover if this call\r
 410                                 fails, but we will report the failure. */\r
 411                                 prvInitialiseTaskLists();\r
 412                         }\r
 413                         else\r
 414                         {       \r
 415                                 /* If the scheduler is not already running, make this task the\r
 416                                 current task if it is the highest priority task to be created\r
 417                                 so far. */\r
 418                                 if( xSchedulerRunning == pdFALSE )\r
 419                                 {\r
 420                                         if( pxCurrentTCB->uxPriority <= uxPriority )\r
 421                                         {\r
 422                                                 pxCurrentTCB = pxNewTCB;        \r
 423                                         }\r
 424                                 }\r
 425                         }                               \r
 426 \r
 427                         /* Remember the top priority to make context switching faster.  Use\r
 428                         the priority in pxNewTCB as this has been capped to a valid value. */\r
 429                         if( pxNewTCB->uxPriority > uxTopUsedPriority )\r
 430                         {\r
 431                                 uxTopUsedPriority = pxNewTCB->uxPriority;\r
 432                         }\r
 433 \r
 434                         #if ( configUSE_TRACE_FACILITY == 1 )\r
 435                         {\r
 436                                 /* Add a counter into the TCB for tracing only. */\r
 437                                 pxNewTCB->uxTCBNumber = uxTaskNumber;\r
 438                                 uxTaskNumber++;\r
 439                         }\r
 440                         #endif\r
 441 \r
 442                         prvAddTaskToReadyQueue( pxNewTCB );\r
 443 \r
 444                         xReturn = pdPASS;\r
 445                         traceTASK_CREATE( pxNewTCB );\r
 446                 }\r
 447                 portEXIT_CRITICAL();\r
 448         }\r
 449         else\r
 450         {\r
 451                 xReturn = errCOULD_NOT_ALLOCATE_REQUIRED_MEMORY;\r
 452                 traceTASK_CREATE_FAILED( pxNewTCB );\r
 453         }\r
 454 \r
 455         if( xReturn == pdPASS )\r
 456         {\r
 457                 if( ( void * ) pxCreatedTask != NULL )\r
 458                 {\r
 459                         /* Pass the TCB out - in an anonymous way.  The calling function/\r
 460                         task can use this as a handle to delete the task later if\r
 461                         required.*/\r
 462                         *pxCreatedTask = ( xTaskHandle ) pxNewTCB;\r
 463                 }\r
 464 \r
 465                 if( xSchedulerRunning != pdFALSE )\r
 466                 {\r
 467                         /* If the created task is of a higher priority than the current task\r
 468                         then it should run now. */\r
 469                         if( pxCurrentTCB->uxPriority < uxPriority )\r
 470                         {\r
 471                                 taskYIELD();\r
 472                         }\r
 473                 }\r
 474         }\r
 475 \r
 476         return xReturn;\r
 477 }\r
 478 /*-----------------------------------------------------------*/\r
 479 \r
 480 #if ( INCLUDE_vTaskDelete == 1 )\r
 481 \r
 482         void vTaskDelete( xTaskHandle pxTaskToDelete )\r
 483         {\r
 484         tskTCB *pxTCB;\r
 485 \r
 486                 taskENTER_CRITICAL();\r
 487                 {\r
 488                         /* Ensure a yield is performed if the current task is being\r
 489                         deleted. */\r
 490                         if( pxTaskToDelete == pxCurrentTCB )\r
 491                         {\r
 492                                 pxTaskToDelete = NULL;\r
 493                         }\r
 494 \r
 495                         /* If null is passed in here then we are deleting ourselves. */\r
 496                         pxTCB = prvGetTCBFromHandle( pxTaskToDelete );\r
 497 \r
 498                         traceTASK_DELETE( pxTCB );\r
 499 \r
 500                         /* Remove task from the ready list and place in the     termination list.\r
 501                         This will stop the task from be scheduled.  The idle task will check\r
 502                         the termination list and free up any memory allocated by the\r
 503                         scheduler for the TCB and stack. */\r
 504                         vListRemove( &( pxTCB->xGenericListItem ) );\r
 505 \r
 506                         /* Is the task waiting on an event also? */                                                                                             \r
 507                         if( pxTCB->xEventListItem.pvContainer )\r
 508                         {\r
 509                                 vListRemove( &( pxTCB->xEventListItem ) );\r
 510                         }\r
 511 \r
 512                         vListInsertEnd( ( xList * ) &xTasksWaitingTermination, &( pxTCB->xGenericListItem ) );\r
 513 \r
 514                         /* Increment the ucTasksDeleted variable so the idle task knows\r
 515                         there is a task that has been deleted and that it should therefore\r
 516                         check the xTasksWaitingTermination list. */\r
 517                         ++uxTasksDeleted;\r
 518                 }\r
 519                 taskEXIT_CRITICAL();\r
 520 \r
 521                 /* Force a reschedule if we have just deleted the current task. */\r
 522                 if( xSchedulerRunning != pdFALSE )\r
 523                 {\r
 524                         if( ( void * ) pxTaskToDelete == NULL )\r
 525                         {\r
 526                                 taskYIELD();\r
 527                         }\r
 528                 }\r
 529         }\r
 530 \r
 531 #endif\r
 532 \r
 533 \r
 534 \r
 535 \r
 536 \r
 537 \r
 538 /*-----------------------------------------------------------\r
 539  * TASK CONTROL API documented in task.h\r
 540  *----------------------------------------------------------*/\r
 541 \r
 542 #if ( INCLUDE_vTaskDelayUntil == 1 )\r
 543 \r
 544         void vTaskDelayUntil( portTickType * const pxPreviousWakeTime, portTickType xTimeIncrement )\r
 545         {\r
 546         portTickType xTimeToWake;\r
 547         portBASE_TYPE xAlreadyYielded, xShouldDelay = pdFALSE;\r
 548 \r
 549                 vTaskSuspendAll();\r
 550                 {\r
 551                         /* Generate the tick time at which the task wants to wake. */\r
 552                         xTimeToWake = *pxPreviousWakeTime + xTimeIncrement;\r
 553 \r
 554                         if( xTickCount < *pxPreviousWakeTime )\r
 555                         {\r
 556                                 /* The tick count has overflowed since this function was\r
 557                                 lasted called.  In this case the only time we should ever\r
 558                                 actually delay is if the wake time has also     overflowed,\r
 559                                 and the wake time is greater than the tick time.  When this\r
 560                                 is the case it is as if neither time had overflowed. */\r
 561                                 if( ( xTimeToWake < *pxPreviousWakeTime ) && ( xTimeToWake > xTickCount ) )\r
 562                                 {\r
 563                                         xShouldDelay = pdTRUE;\r
 564                                 }\r
 565                         }\r
 566                         else\r
 567                         {\r
 568                                 /* The tick time has not overflowed.  In this case we will\r
 569                                 delay if either the wake time has overflowed, and/or the\r
 570                                 tick time is less than the wake time. */\r
 571                                 if( ( xTimeToWake < *pxPreviousWakeTime ) || ( xTimeToWake > xTickCount ) )\r
 572                                 {\r
 573                                         xShouldDelay = pdTRUE;\r
 574                                 }\r
 575                         }\r
 576 \r
 577                         /* Update the wake time ready for the next call. */\r
 578                         *pxPreviousWakeTime = xTimeToWake;\r
 579 \r
 580                         if( xShouldDelay )\r
 581                         {\r
 582                                 traceTASK_DELAY_UNTIL();\r
 583 \r
 584                                 /* We must remove ourselves from the ready list before adding\r
 585                                 ourselves to the blocked list as the same list item is used for\r
 586                                 both lists. */\r
 587                                 vListRemove( ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );\r
 588 \r
 589                                 /* The list item will be inserted in wake time order. */\r
 590                                 listSET_LIST_ITEM_VALUE( &( pxCurrentTCB->xGenericListItem ), xTimeToWake );\r
 591 \r
 592                                 if( xTimeToWake < xTickCount )\r
 593                                 {\r
 594                                         /* Wake time has overflowed.  Place this item in the\r
 595                                         overflow list. */\r
 596                                         vListInsert( ( xList * ) pxOverflowDelayedTaskList, ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );\r
 597                                 }\r
 598                                 else\r
 599                                 {\r
 600                                         /* The wake time has not overflowed, so we can use the\r
 601                                         current block list. */\r
 602                                         vListInsert( ( xList * ) pxDelayedTaskList, ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );\r
 603                                 }\r
 604                         }\r
 605                 }\r
 606                 xAlreadyYielded = xTaskResumeAll();\r
 607 \r
 608                 /* Force a reschedule if xTaskResumeAll has not already done so, we may\r
 609                 have put ourselves to sleep. */\r
 610                 if( !xAlreadyYielded )\r
 611                 {\r
 612                         taskYIELD();\r
 613                 }\r
 614         }       \r
 615         \r
 616 #endif\r
 617 /*-----------------------------------------------------------*/\r
 618 \r
 619 #if ( INCLUDE_vTaskDelay == 1 )\r
 620 \r
 621         void vTaskDelay( portTickType xTicksToDelay )\r
 622         {\r
 623         portTickType xTimeToWake;\r
 624         signed portBASE_TYPE xAlreadyYielded = pdFALSE;\r
 625 \r
 626                 /* A delay time of zero just forces a reschedule. */\r
 627                 if( xTicksToDelay > ( portTickType ) 0 )\r
 628                 {\r
 629                         vTaskSuspendAll();\r
 630                         {\r
 631                                 traceTASK_DELAY();\r
 632 \r
 633                                 /* A task that is removed from the event list while the\r
 634                                 scheduler is suspended will not get placed in the ready\r
 635                                 list or removed from the blocked list until the scheduler\r
 636                                 is resumed.\r
 637                                 \r
 638                                 This task cannot be in an event list as it is the currently\r
 639                                 executing task. */\r
 640 \r
 641                                 /* Calculate the time to wake - this may overflow but this is\r
 642                                 not a problem. */\r
 643                                 xTimeToWake = xTickCount + xTicksToDelay;\r
 644 \r
 645                                 /* We must remove ourselves from the ready list before adding\r
 646                                 ourselves to the blocked list as the same list item is used for\r
 647                                 both lists. */\r
 648                                 vListRemove( ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );\r
 649 \r
 650                                 /* The list item will be inserted in wake time order. */\r
 651                                 listSET_LIST_ITEM_VALUE( &( pxCurrentTCB->xGenericListItem ), xTimeToWake );\r
 652 \r
 653                                 if( xTimeToWake < xTickCount )\r
 654                                 {\r
 655                                         /* Wake time has overflowed.  Place this item in the\r
 656                                         overflow list. */\r
 657                                         vListInsert( ( xList * ) pxOverflowDelayedTaskList, ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );\r
 658                                 }\r
 659                                 else\r
 660                                 {\r
 661                                         /* The wake time has not overflowed, so we can use the\r
 662                                         current block list. */\r
 663                                         vListInsert( ( xList * ) pxDelayedTaskList, ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );\r
 664                                 }\r
 665                         }\r
 666                         xAlreadyYielded = xTaskResumeAll();\r
 667                 }\r
 668                 \r
 669                 /* Force a reschedule if xTaskResumeAll has not already done so, we may\r
 670                 have put ourselves to sleep. */\r
 671                 if( !xAlreadyYielded )\r
 672                 {\r
 673                         taskYIELD();\r
 674                 }\r
 675         }\r
 676         \r
 677 #endif\r
 678 /*-----------------------------------------------------------*/\r
 679 \r
 680 #if ( INCLUDE_uxTaskPriorityGet == 1 )\r
 681 \r
 682         unsigned portBASE_TYPE uxTaskPriorityGet( xTaskHandle pxTask )\r
 683         {\r
 684         tskTCB *pxTCB;\r
 685         unsigned portBASE_TYPE uxReturn;\r
 686 \r
 687                 taskENTER_CRITICAL();\r
 688                 {\r
 689                         /* If null is passed in here then we are changing the\r
 690                         priority of the calling function. */\r
 691                         pxTCB = prvGetTCBFromHandle( pxTask );\r
 692                         uxReturn = pxTCB->uxPriority;\r
 693                 }\r
 694                 taskEXIT_CRITICAL();\r
 695 \r
 696                 return uxReturn;\r
 697         }\r
 698 \r
 699 #endif\r
 700 /*-----------------------------------------------------------*/\r
 701 \r
 702 #if ( INCLUDE_vTaskPrioritySet == 1 )\r
 703 \r
 704         void vTaskPrioritySet( xTaskHandle pxTask, unsigned portBASE_TYPE uxNewPriority )\r
 705         {\r
 706         tskTCB *pxTCB;\r
 707         unsigned portBASE_TYPE uxCurrentPriority, xYieldRequired = pdFALSE;\r
 708 \r
 709                 /* Ensure the new priority is valid. */\r
 710                 if( uxNewPriority >= configMAX_PRIORITIES )\r
 711                 {\r
 712                         uxNewPriority = configMAX_PRIORITIES - 1;\r
 713                 }\r
 714 \r
 715                 taskENTER_CRITICAL();\r
 716                 {\r
 717                         if( pxTask == pxCurrentTCB )\r
 718                         {\r
 719                                 pxTask = NULL;\r
 720                         }\r
 721 \r
 722                         /* If null is passed in here then we are changing the\r
 723                         priority of the calling function. */\r
 724                         pxTCB = prvGetTCBFromHandle( pxTask );\r
 725                         \r
 726                         traceTASK_PRIORITY_SET( pxTask, uxNewPriority );\r
 727 \r
 728                         #if ( configUSE_MUTEXES == 1 )\r
 729                         {\r
 730                                 uxCurrentPriority = pxTCB->uxBasePriority;\r
 731                         }\r
 732                         #else\r
 733                         {\r
 734                                 uxCurrentPriority = pxTCB->uxPriority;\r
 735                         }\r
 736                         #endif\r
 737 \r
 738                         if( uxCurrentPriority != uxNewPriority )\r
 739                         {\r
 740                                 /* The priority change may have readied a task of higher\r
 741                                 priority than the calling task. */\r
 742                                 if( uxNewPriority > uxCurrentPriority )\r
 743                                 {\r
 744                                         if( pxTask != NULL )\r
 745                                         {\r
 746                                                 /* The priority of another task is being raised.  If we\r
 747                                                 were raising the priority of the currently running task\r
 748                                                 there would be no need to switch as it must have already\r
 749                                                 been the highest priority task. */\r
 750                                                 xYieldRequired = pdTRUE;\r
 751                                         }\r
 752                                 }\r
 753                                 else if( pxTask == NULL )\r
 754                                 {\r
 755                                         /* Setting our own priority down means there may now be another\r
 756                                         task of higher priority that is ready to execute. */\r
 757                                         xYieldRequired = pdTRUE;\r
 758                                 }\r
 759                         \r
 760                                 \r
 761 \r
 762                                 #if ( configUSE_MUTEXES == 1 )\r
 763                                 {\r
 764                                         /* Only change the priority being used if the task is not\r
 765                                         currently using an inherited priority. */\r
 766                                         if( pxTCB->uxBasePriority == pxTCB->uxPriority )\r
 767                                         {\r
 768                                                 pxTCB->uxPriority = uxNewPriority;\r
 769                                         }\r
 770                                         \r
 771                                         /* The base priority gets set whatever. */\r
 772                                         pxTCB->uxBasePriority = uxNewPriority;                                  \r
 773                                 }\r
 774                                 #else\r
 775                                 {\r
 776                                         pxTCB->uxPriority = uxNewPriority;\r
 777                                 }\r
 778                                 #endif\r
 779 \r
 780                                 listSET_LIST_ITEM_VALUE( &( pxTCB->xEventListItem ), ( configMAX_PRIORITIES - ( portTickType ) uxNewPriority ) );\r
 781 \r
 782                                 /* If the task is in the blocked or suspended list we need do\r
 783                                 nothing more than change it's priority variable. However, if\r
 784                                 the task is in a ready list it needs to be removed and placed\r
 785                                 in the queue appropriate to its new priority. */\r
 786                                 if( listIS_CONTAINED_WITHIN( &( pxReadyTasksLists[ uxCurrentPriority ] ), &( pxTCB->xGenericListItem ) ) )\r
 787                                 {\r
 788                                         /* The task is currently in its ready list - remove before adding\r
 789                                         it to it's new ready list.  As we are in a critical section we\r
 790                                         can do this even if the scheduler is suspended. */\r
 791                                         vListRemove( &( pxTCB->xGenericListItem ) );\r
 792                                         prvAddTaskToReadyQueue( pxTCB );\r
 793                                 }                       \r
 794                                 \r
 795                                 if( xYieldRequired == pdTRUE )\r
 796                                 {\r
 797                                         taskYIELD();\r
 798                                 }                               \r
 799                         }\r
 800                 }\r
 801                 taskEXIT_CRITICAL();\r
 802         }\r
 803 \r
 804 #endif\r
 805 /*-----------------------------------------------------------*/\r
 806 \r
 807 #if ( INCLUDE_vTaskSuspend == 1 )\r
 808 \r
 809         void vTaskSuspend( xTaskHandle pxTaskToSuspend )\r
 810         {\r
 811         tskTCB *pxTCB;\r
 812 \r
 813                 taskENTER_CRITICAL();\r
 814                 {\r
 815                         /* Ensure a yield is performed if the current task is being\r
 816                         suspended. */\r
 817                         if( pxTaskToSuspend == pxCurrentTCB )\r
 818                         {\r
 819                                 pxTaskToSuspend = NULL;\r
 820                         }\r
 821 \r
 822                         /* If null is passed in here then we are suspending ourselves. */\r
 823                         pxTCB = prvGetTCBFromHandle( pxTaskToSuspend );\r
 824 \r
 825                         traceTASK_SUSPEND( pxTaskToSuspend );\r
 826 \r
 827                         /* Remove task from the ready/delayed list and place in the     suspended list. */\r
 828                         vListRemove( &( pxTCB->xGenericListItem ) );\r
 829 \r
 830                         /* Is the task waiting on an event also? */                                                                                             \r
 831                         if( pxTCB->xEventListItem.pvContainer )\r
 832                         {\r
 833                                 vListRemove( &( pxTCB->xEventListItem ) );\r
 834                         }\r
 835 \r
 836                         vListInsertEnd( ( xList * ) &xSuspendedTaskList, &( pxTCB->xGenericListItem ) );\r
 837                 }\r
 838                 taskEXIT_CRITICAL();\r
 839 \r
 840                 /* We may have just suspended the current task. */\r
 841                 if( ( void * ) pxTaskToSuspend == NULL )\r
 842                 {\r
 843                         taskYIELD();\r
 844                 }\r
 845         }\r
 846 \r
 847 #endif\r
 848 /*-----------------------------------------------------------*/\r
 849 \r
 850 #if ( INCLUDE_vTaskSuspend == 1 )\r
 851 \r
 852         signed portBASE_TYPE xTaskIsTaskSuspended( xTaskHandle xTask )\r
 853         {\r
 854         portBASE_TYPE xReturn = pdFALSE;\r
 855         const tskTCB * const pxTCB = ( tskTCB * ) xTask;\r
 856 \r
 857                 /* Is the task we are attempting to resume actually in the\r
 858                 suspended list? */\r
 859                 if( listIS_CONTAINED_WITHIN( &xSuspendedTaskList, &( pxTCB->xGenericListItem ) ) != pdFALSE )\r
 860                 {\r
 861                         /* Has the task already been resumed from within an ISR? */\r
 862                         if( listIS_CONTAINED_WITHIN( &xPendingReadyList, &( pxTCB->xEventListItem ) ) != pdTRUE )\r
 863                         {                       \r
 864                                 /* Is it in the suspended list because it is in the\r
 865                                 Suspended state?  It is possible to be in the suspended\r
 866                                 list because it is blocked on a task with no timeout\r
 867                                 specified. */\r
 868                                 if( listIS_CONTAINED_WITHIN( NULL, &( pxTCB->xEventListItem ) ) == pdTRUE )\r
 869                                 {\r
 870                                         xReturn = pdTRUE;\r
 871                                 }\r
 872                         }\r
 873                 }\r
 874 \r
 875                 return xReturn;\r
 876         }\r
 877 \r
 878 #endif\r
 879 /*-----------------------------------------------------------*/\r
 880 \r
 881 #if ( INCLUDE_vTaskSuspend == 1 )\r
 882 \r
 883         void vTaskResume( xTaskHandle pxTaskToResume )\r
 884         {\r
 885         tskTCB *pxTCB;\r
 886 \r
 887                 /* Remove the task from whichever list it is currently in, and place\r
 888                 it in the ready list. */\r
 889                 pxTCB = ( tskTCB * ) pxTaskToResume;\r
 890 \r
 891                 /* The parameter cannot be NULL as it is impossible to resume the\r
 892                 currently executing task. */\r
 893                 if( ( pxTCB != NULL ) && ( pxTCB != pxCurrentTCB ) )\r
 894                 {\r
 895                         taskENTER_CRITICAL();\r
 896                         {\r
 897                                 if( xTaskIsTaskSuspended( pxTCB ) == pdTRUE )\r
 898                                 {\r
 899                                         traceTASK_RESUME( pxTCB );\r
 900 \r
 901                                         /* As we are in a critical section we can access the ready\r
 902                                         lists even if the scheduler is suspended. */\r
 903                                         vListRemove(  &( pxTCB->xGenericListItem ) );\r
 904                                         prvAddTaskToReadyQueue( pxTCB );\r
 905 \r
 906                                         /* We may have just resumed a higher priority task. */\r
 907                                         if( pxTCB->uxPriority >= pxCurrentTCB->uxPriority )\r
 908                                         {\r
 909                                                 /* This yield may not cause the task just resumed to run, but\r
 910                                                 will leave the lists in the correct state for the next yield. */\r
 911                                                 taskYIELD();\r
 912                                         }\r
 913                                 }\r
 914                         }\r
 915                         taskEXIT_CRITICAL();\r
 916                 }\r
 917         }\r
 918 \r
 919 #endif\r
 920 \r
 921 /*-----------------------------------------------------------*/\r
 922 \r
 923 #if ( ( INCLUDE_xTaskResumeFromISR == 1 ) && ( INCLUDE_vTaskSuspend == 1 ) )\r
 924 \r
 925         portBASE_TYPE xTaskResumeFromISR( xTaskHandle pxTaskToResume )\r
 926         {\r
 927         portBASE_TYPE xYieldRequired = pdFALSE;\r
 928         tskTCB *pxTCB;\r
 929 \r
 930                 pxTCB = ( tskTCB * ) pxTaskToResume;\r
 931 \r
 932                 if( xTaskIsTaskSuspended( pxTCB ) == pdTRUE )\r
 933                 {\r
 934                         traceTASK_RESUME_FROM_ISR( pxTCB );\r
 935 \r
 936                         if( uxSchedulerSuspended == ( unsigned portBASE_TYPE ) pdFALSE )\r
 937                         {\r
 938                                 xYieldRequired = ( pxTCB->uxPriority >= pxCurrentTCB->uxPriority );\r
 939                                 vListRemove(  &( pxTCB->xGenericListItem ) );   \r
 940                                 prvAddTaskToReadyQueue( pxTCB );\r
 941                         }\r
 942                         else\r
 943                         {\r
 944                                 /* We cannot access the delayed or ready lists, so will hold this\r
 945                                 task pending until the scheduler is resumed, at which point a\r
 946                                 yield will be performed if necessary. */\r
 947                                 vListInsertEnd( ( xList * ) &( xPendingReadyList ), &( pxTCB->xEventListItem ) );\r
 948                         }\r
 949                 }\r
 950 \r
 951                 return xYieldRequired;\r
 952         }\r
 953 \r
 954 #endif\r
 955 \r
 956 \r
 957 \r
 958 \r
 959 /*-----------------------------------------------------------\r
 960  * PUBLIC SCHEDULER CONTROL documented in task.h\r
 961  *----------------------------------------------------------*/\r
 962 \r
 963 \r
 964 void vTaskStartScheduler( void )\r
 965 {\r
 966 portBASE_TYPE xReturn;\r
 967 \r
 968         /* Add the idle task at the lowest priority. */\r
 969         xReturn = xTaskCreate( prvIdleTask, ( signed portCHAR * ) "IDLE", tskIDLE_STACK_SIZE, ( void * ) NULL, tskIDLE_PRIORITY, ( xTaskHandle * ) NULL );\r
 970 \r
 971         if( xReturn == pdPASS )\r
 972         {\r
 973                 /* Interrupts are turned off here, to ensure a tick does not occur\r
 974                 before or during the call to xPortStartScheduler().  The stacks of\r
 975                 the created tasks contain a status word with interrupts switched on\r
 976                 so interrupts will automatically get re-enabled when the first task\r
 977                 starts to run.\r
 978                 \r
 979                 STEPPING THROUGH HERE USING A DEBUGGER CAN CAUSE BIG PROBLEMS IF THE\r
 980                 DEBUGGER ALLOWS INTERRUPTS TO BE PROCESSED. */\r
 981                 portDISABLE_INTERRUPTS();\r
 982 \r
 983                 xSchedulerRunning = pdTRUE;\r
 984                 xTickCount = ( portTickType ) 0;\r
 985 \r
 986                 /* Setting up the timer tick is hardware specific and thus in the\r
 987                 portable interface. */\r
 988                 if( xPortStartScheduler() )\r
 989                 {\r
 990                         /* Should not reach here as if the scheduler is running the\r
 991                         function will not return. */\r
 992                 }\r
 993                 else\r
 994                 {\r
 995                         /* Should only reach here if a task calls xTaskEndScheduler(). */\r
 996                 }\r
 997         }\r
 998 }\r
 999 /*-----------------------------------------------------------*/\r
1000 \r
1001 void vTaskEndScheduler( void )\r
1002 {\r
1003         /* Stop the scheduler interrupts and call the portable scheduler end\r
1004         routine so the original ISRs can be restored if necessary.  The port\r
1005         layer must ensure interrupts enable     bit is left in the correct state. */\r
1006         portDISABLE_INTERRUPTS();\r
1007         xSchedulerRunning = pdFALSE;\r
1008         vPortEndScheduler();\r
1009 }\r
1010 /*----------------------------------------------------------*/\r
1011 \r
1012 void vTaskSuspendAll( void )\r
1013 {\r
1014         portENTER_CRITICAL();\r
1015                 ++uxSchedulerSuspended;\r
1016         portEXIT_CRITICAL();\r
1017 }\r
1018 /*----------------------------------------------------------*/\r
1019 \r
1020 signed portBASE_TYPE xTaskResumeAll( void )\r
1021 {\r
1022 register tskTCB *pxTCB;\r
1023 signed portBASE_TYPE xAlreadyYielded = pdFALSE;\r
1024 \r
1025         /* It is possible that an ISR caused a task to be removed from an event\r
1026         list while the scheduler was suspended.  If this was the case then the\r
1027         removed task will have been added to the xPendingReadyList.  Once the\r
1028         scheduler has been resumed it is safe to move all the pending ready\r
1029         tasks from this list into their appropriate ready list. */\r
1030         portENTER_CRITICAL();\r
1031         {\r
1032                 --uxSchedulerSuspended;\r
1033 \r
1034                 if( uxSchedulerSuspended == ( unsigned portBASE_TYPE ) pdFALSE )\r
1035                 {                       \r
1036                         if( uxCurrentNumberOfTasks > ( unsigned portBASE_TYPE ) 0 )\r
1037                         {\r
1038                                 portBASE_TYPE xYieldRequired = pdFALSE;\r
1039                                 \r
1040                                 /* Move any readied tasks from the pending list into the\r
1041                                 appropriate ready list. */\r
1042                                 while( ( pxTCB = ( tskTCB * ) listGET_OWNER_OF_HEAD_ENTRY(  ( ( xList * ) &xPendingReadyList ) ) ) != NULL )\r
1043                                 {\r
1044                                         vListRemove( &( pxTCB->xEventListItem ) );\r
1045                                         vListRemove( &( pxTCB->xGenericListItem ) );\r
1046                                         prvAddTaskToReadyQueue( pxTCB );\r
1047                                         \r
1048                                         /* If we have moved a task that has a priority higher than\r
1049                                         the current task then we should yield. */\r
1050                                         if( pxTCB->uxPriority >= pxCurrentTCB->uxPriority )\r
1051                                         {\r
1052                                                 xYieldRequired = pdTRUE;\r
1053                                         }\r
1054                                 }\r
1055 \r
1056                                 /* If any ticks occurred while the scheduler was suspended then\r
1057                                 they should be processed now.  This ensures the tick count does not\r
1058                                 slip, and that any delayed tasks are resumed at the correct time. */\r
1059                                 if( uxMissedTicks > ( unsigned portBASE_TYPE ) 0 )\r
1060                                 {\r
1061                                         while( uxMissedTicks > ( unsigned portBASE_TYPE ) 0 )\r
1062                                         {\r
1063                                                 vTaskIncrementTick();\r
1064                                                 --uxMissedTicks;\r
1065                                         }\r
1066 \r
1067                                         /* As we have processed some ticks it is appropriate to yield\r
1068                                         to ensure the highest priority task that is ready to run is\r
1069                                         the task actually running. */\r
1070                                         #if configUSE_PREEMPTION == 1\r
1071                                         {\r
1072                                                 xYieldRequired = pdTRUE;\r
1073                                         }\r
1074                                         #endif\r
1075                                 }\r
1076                                 \r
1077                                 if( ( xYieldRequired == pdTRUE ) || ( xMissedYield == pdTRUE ) )\r
1078                                 {\r
1079                                         xAlreadyYielded = pdTRUE;\r
1080                                         xMissedYield = pdFALSE;\r
1081                                         taskYIELD();\r
1082                                 }\r
1083                         }\r
1084                 }\r
1085         }\r
1086         portEXIT_CRITICAL();\r
1087 \r
1088         return xAlreadyYielded;\r
1089 }\r
1090 \r
1091 \r
1092 \r
1093 \r
1094 \r
1095 \r
1096 /*-----------------------------------------------------------\r
1097  * PUBLIC TASK UTILITIES documented in task.h\r
1098  *----------------------------------------------------------*/\r
1099 \r
1100 \r
1101 \r
1102 portTickType xTaskGetTickCount( void )\r
1103 {\r
1104 portTickType xTicks;\r
1105 \r
1106         /* Critical section required if running on a 16 bit processor. */\r
1107         taskENTER_CRITICAL();\r
1108         {\r
1109                 xTicks = xTickCount;\r
1110         }\r
1111         taskEXIT_CRITICAL();\r
1112 \r
1113         return xTicks;\r
1114 }\r
1115 /*-----------------------------------------------------------*/\r
1116 \r
1117 unsigned portBASE_TYPE uxTaskGetNumberOfTasks( void )\r
1118 {\r
1119 unsigned portBASE_TYPE uxNumberOfTasks;\r
1120 \r
1121         taskENTER_CRITICAL();\r
1122                 uxNumberOfTasks = uxCurrentNumberOfTasks;\r
1123         taskEXIT_CRITICAL();\r
1124 \r
1125         return uxNumberOfTasks;\r
1126 }\r
1127 /*-----------------------------------------------------------*/\r
1128 \r
1129 #if ( ( configUSE_TRACE_FACILITY == 1 ) && ( INCLUDE_vTaskDelete == 1 ) && ( INCLUDE_vTaskSuspend == 1 ) )\r
1130 \r
1131         void vTaskList( signed portCHAR *pcWriteBuffer )\r
1132         {\r
1133         unsigned portBASE_TYPE uxQueue;\r
1134 \r
1135                 /* This is a VERY costly function that should be used for debug only.\r
1136                 It leaves interrupts disabled for a LONG time. */\r
1137 \r
1138         vTaskSuspendAll();\r
1139                 {\r
1140                         /* Run through all the lists that could potentially contain a TCB and\r
1141                         report the task name, state and stack high water mark. */\r
1142 \r
1143                         pcWriteBuffer[ 0 ] = ( signed portCHAR ) 0x00;\r
1144                         strcat( ( portCHAR * ) pcWriteBuffer, ( const portCHAR * ) "\r\n" );\r
1145 \r
1146                         uxQueue = uxTopUsedPriority + 1;\r
1147 \r
1148                         do\r
1149                         {\r
1150                                 uxQueue--;\r
1151 \r
1152                                 if( !listLIST_IS_EMPTY( &( pxReadyTasksLists[ uxQueue ] ) ) )\r
1153                                 {\r
1154                                         prvListTaskWithinSingleList( pcWriteBuffer, ( xList * ) &( pxReadyTasksLists[ uxQueue ] ), tskREADY_CHAR );                     \r
1155                                 }\r
1156                         }while( uxQueue > ( unsigned portSHORT ) tskIDLE_PRIORITY );\r
1157 \r
1158                         if( !listLIST_IS_EMPTY( pxDelayedTaskList ) )\r
1159                         {\r
1160                                 prvListTaskWithinSingleList( pcWriteBuffer, ( xList * ) pxDelayedTaskList, tskBLOCKED_CHAR );\r
1161                         }\r
1162 \r
1163                         if( !listLIST_IS_EMPTY( pxOverflowDelayedTaskList ) )\r
1164                         {\r
1165                                 prvListTaskWithinSingleList( pcWriteBuffer, ( xList * ) pxOverflowDelayedTaskList, tskBLOCKED_CHAR );\r
1166                         }\r
1167 \r
1168                         if( !listLIST_IS_EMPTY( &xTasksWaitingTermination ) )\r
1169                         {\r
1170                                 prvListTaskWithinSingleList( pcWriteBuffer, ( xList * ) &xTasksWaitingTermination, tskDELETED_CHAR );\r
1171                         }\r
1172 \r
1173                         if( !listLIST_IS_EMPTY( &xSuspendedTaskList ) )\r
1174                         {\r
1175                                 prvListTaskWithinSingleList( pcWriteBuffer, ( xList * ) &xSuspendedTaskList, tskSUSPENDED_CHAR );\r
1176                         }\r
1177                 }\r
1178         xTaskResumeAll();\r
1179         }\r
1180 \r
1181 #endif\r
1182 /*----------------------------------------------------------*/\r
1183 \r
1184 #if ( configUSE_TRACE_FACILITY == 1 )\r
1185 \r
1186         void vTaskStartTrace( signed portCHAR * pcBuffer, unsigned portLONG ulBufferSize )\r
1187         {\r
1188                 portENTER_CRITICAL();\r
1189                 {\r
1190                         pcTraceBuffer = ( signed portCHAR * )pcBuffer;\r
1191                         pcTraceBufferStart = pcBuffer;\r
1192                         pcTraceBufferEnd = pcBuffer + ( ulBufferSize - tskSIZE_OF_EACH_TRACE_LINE );\r
1193                         xTracing = pdTRUE;\r
1194                 }\r
1195                 portEXIT_CRITICAL();\r
1196         }\r
1197 \r
1198 #endif\r
1199 /*----------------------------------------------------------*/\r
1200 \r
1201 #if ( configUSE_TRACE_FACILITY == 1 )\r
1202 \r
1203         unsigned portLONG ulTaskEndTrace( void )\r
1204         {\r
1205         unsigned portLONG ulBufferLength;\r
1206 \r
1207                 portENTER_CRITICAL();\r
1208                         xTracing = pdFALSE;\r
1209                 portEXIT_CRITICAL();\r
1210 \r
1211                 ulBufferLength = ( unsigned portLONG ) ( pcTraceBuffer - pcTraceBufferStart );\r
1212 \r
1213                 return ulBufferLength;\r
1214         }\r
1215 \r
1216 #endif\r
1217 \r
1218 \r
1219 \r
1220 /*-----------------------------------------------------------\r
1221  * SCHEDULER INTERNALS AVAILABLE FOR PORTING PURPOSES\r
1222  * documented in task.h\r
1223  *----------------------------------------------------------*/\r
1224 \r
1225 \r
1226 void vTaskIncrementTick( void )\r
1227 {\r
1228         /* Called by the portable layer each time a tick interrupt occurs.\r
1229         Increments the tick then checks to see if the new tick value will cause any\r
1230         tasks to be unblocked. */\r
1231         if( uxSchedulerSuspended == ( unsigned portBASE_TYPE ) pdFALSE )\r
1232         {\r
1233                 ++xTickCount;\r
1234                 if( xTickCount == ( portTickType ) 0 )\r
1235                 {\r
1236                         xList *pxTemp;\r
1237 \r
1238                         /* Tick count has overflowed so we need to swap the delay lists.\r
1239                         If there are any items in pxDelayedTaskList here then there is\r
1240                         an error! */\r
1241                         pxTemp = pxDelayedTaskList;\r
1242                         pxDelayedTaskList = pxOverflowDelayedTaskList;\r
1243                         pxOverflowDelayedTaskList = pxTemp;\r
1244             xNumOfOverflows++;\r
1245                 }\r
1246 \r
1247                 /* See if this tick has made a timeout expire. */\r
1248                 prvCheckDelayedTasks();\r
1249         }\r
1250         else\r
1251         {\r
1252                 ++uxMissedTicks;\r
1253 \r
1254                 /* The tick hook gets called at regular intervals, even if the\r
1255                 scheduler is locked. */\r
1256                 #if ( configUSE_TICK_HOOK == 1 )\r
1257                 {\r
1258                         extern void vApplicationTickHook( void );\r
1259 \r
1260                         vApplicationTickHook();\r
1261                 }\r
1262                 #endif\r
1263         }\r
1264 \r
1265         #if ( configUSE_TICK_HOOK == 1 )\r
1266         {\r
1267                 extern void vApplicationTickHook( void );\r
1268 \r
1269                 /* Guard against the tick hook being called when the missed tick\r
1270                 count is being unwound (when the scheduler is being unlocked. */\r
1271                 if( uxMissedTicks == 0 )\r
1272                 {\r
1273                         vApplicationTickHook();\r
1274                 }\r
1275         }\r
1276         #endif\r
1277 \r
1278         traceTASK_INCREMENT_TICK( xTickCount );\r
1279 }\r
1280 /*-----------------------------------------------------------*/\r
1281 \r
1282 #if ( ( INCLUDE_vTaskCleanUpResources == 1 ) && ( INCLUDE_vTaskSuspend == 1 ) )\r
1283 \r
1284         void vTaskCleanUpResources( void )\r
1285         {\r
1286         unsigned portSHORT usQueue;\r
1287         volatile tskTCB *pxTCB;\r
1288 \r
1289                 usQueue = ( unsigned portSHORT ) uxTopUsedPriority + ( unsigned portSHORT ) 1;\r
1290 \r
1291                 /* Remove any TCB's from the ready queues. */\r
1292                 do\r
1293                 {\r
1294                         usQueue--;\r
1295 \r
1296                         while( !listLIST_IS_EMPTY( &( pxReadyTasksLists[ usQueue ] ) ) )\r
1297                         {\r
1298                                 listGET_OWNER_OF_NEXT_ENTRY( pxTCB, &( pxReadyTasksLists[ usQueue ] ) );\r
1299                                 vListRemove( ( xListItem * ) &( pxTCB->xGenericListItem ) );\r
1300 \r
1301                                 prvDeleteTCB( ( tskTCB * ) pxTCB );\r
1302                         }\r
1303                 }while( usQueue > ( unsigned portSHORT ) tskIDLE_PRIORITY );\r
1304 \r
1305                 /* Remove any TCB's from the delayed queue. */\r
1306                 while( !listLIST_IS_EMPTY( &xDelayedTaskList1 ) )\r
1307                 {\r
1308                         listGET_OWNER_OF_NEXT_ENTRY( pxTCB, &xDelayedTaskList1 );\r
1309                         vListRemove( ( xListItem * ) &( pxTCB->xGenericListItem ) );\r
1310 \r
1311                         prvDeleteTCB( ( tskTCB * ) pxTCB );\r
1312                 }\r
1313 \r
1314                 /* Remove any TCB's from the overflow delayed queue. */\r
1315                 while( !listLIST_IS_EMPTY( &xDelayedTaskList2 ) )\r
1316                 {\r
1317                         listGET_OWNER_OF_NEXT_ENTRY( pxTCB, &xDelayedTaskList2 );\r
1318                         vListRemove( ( xListItem * ) &( pxTCB->xGenericListItem ) );\r
1319 \r
1320                         prvDeleteTCB( ( tskTCB * ) pxTCB );\r
1321                 }\r
1322 \r
1323                 while( !listLIST_IS_EMPTY( &xSuspendedTaskList ) )\r
1324                 {\r
1325                         listGET_OWNER_OF_NEXT_ENTRY( pxTCB, &xSuspendedTaskList );\r
1326                         vListRemove( ( xListItem * ) &( pxTCB->xGenericListItem ) );\r
1327 \r
1328                         prvDeleteTCB( ( tskTCB * ) pxTCB );\r
1329                 }               \r
1330         }\r
1331 \r
1332 #endif\r
1333 /*-----------------------------------------------------------*/\r
1334 \r
1335 #if ( configUSE_APPLICATION_TASK_TAG == 1 )\r
1336 \r
1337         void vTaskSetApplicationTaskTag( xTaskHandle xTask, pdTASK_HOOK_CODE pxTagValue )\r
1338         {\r
1339         tskTCB *xTCB;\r
1340 \r
1341                 /* If xTask is NULL then we are setting our own task hook. */\r
1342                 if( xTask == NULL )\r
1343                 {\r
1344                         xTCB = ( tskTCB * ) pxCurrentTCB;\r
1345                 }\r
1346                 else\r
1347                 {\r
1348                         xTCB = ( tskTCB * ) xTask;\r
1349                 }\r
1350                 \r
1351                 /* Save the hook function in the TCB. */\r
1352                 portENTER_CRITICAL();\r
1353                         xTCB->pxTaskTag = pxTagValue;\r
1354                 portEXIT_CRITICAL();\r
1355         }\r
1356         \r
1357 #endif\r
1358 /*-----------------------------------------------------------*/\r
1359 \r
1360 #if ( configUSE_APPLICATION_TASK_TAG == 1 )\r
1361 \r
1362         portBASE_TYPE xTaskCallApplicationTaskHook( xTaskHandle xTask, void *pvParameter )\r
1363         {\r
1364         tskTCB *xTCB;\r
1365         portBASE_TYPE xReturn;\r
1366 \r
1367                 /* If xTask is NULL then we are calling our own task hook. */\r
1368                 if( xTask == NULL )\r
1369                 {\r
1370                         xTCB = ( tskTCB * ) pxCurrentTCB;\r
1371                 }\r
1372                 else\r
1373                 {\r
1374                         xTCB = ( tskTCB * ) xTask;\r
1375                 }\r
1376 \r
1377                 if( xTCB->pxTaskTag != NULL )\r
1378                 {\r
1379                         xReturn = xTCB->pxTaskTag( pvParameter );\r
1380                 }\r
1381                 else\r
1382                 {\r
1383                         xReturn = pdFAIL;\r
1384                 }\r
1385 \r
1386                 return xReturn;\r
1387         }\r
1388         \r
1389 #endif\r
1390 /*-----------------------------------------------------------*/\r
1391 \r
1392 void vTaskSwitchContext( void )\r
1393 {\r
1394         traceTASK_SWITCHED_OUT();\r
1395 \r
1396         if( uxSchedulerSuspended != ( unsigned portBASE_TYPE ) pdFALSE )\r
1397         {\r
1398                 /* The scheduler is currently suspended - do not allow a context\r
1399                 switch. */\r
1400                 xMissedYield = pdTRUE;\r
1401                 return;\r
1402         }\r
1403 \r
1404         taskFIRST_CHECK_FOR_STACK_OVERFLOW();\r
1405         taskSECOND_CHECK_FOR_STACK_OVERFLOW();\r
1406 \r
1407         /* Find the highest priority queue that contains ready tasks. */\r
1408         while( listLIST_IS_EMPTY( &( pxReadyTasksLists[ uxTopReadyPriority ] ) ) )\r
1409         {\r
1410                 --uxTopReadyPriority;\r
1411         }\r
1412 \r
1413         /* listGET_OWNER_OF_NEXT_ENTRY walks through the list, so the tasks of the\r
1414         same priority get an equal share of the processor time. */\r
1415         listGET_OWNER_OF_NEXT_ENTRY( pxCurrentTCB, &( pxReadyTasksLists[ uxTopReadyPriority ] ) );\r
1416 \r
1417         traceTASK_SWITCHED_IN();\r
1418         vWriteTraceToBuffer();\r
1419 }\r
1420 /*-----------------------------------------------------------*/\r
1421 \r
1422 void vTaskPlaceOnEventList( const xList * const pxEventList, portTickType xTicksToWait )\r
1423 {\r
1424 portTickType xTimeToWake;\r
1425 \r
1426         /* THIS FUNCTION MUST BE CALLED WITH INTERRUPTS DISABLED OR THE\r
1427         SCHEDULER SUSPENDED. */\r
1428 \r
1429         /* Place the event list item of the TCB in the appropriate event list.\r
1430         This is placed in the list in priority order so the highest priority task\r
1431         is the first to be woken by the event. */\r
1432         vListInsert( ( xList * ) pxEventList, ( xListItem * ) &( pxCurrentTCB->xEventListItem ) );\r
1433 \r
1434         /* We must remove ourselves from the ready list before adding ourselves\r
1435         to the blocked list as the same list item is used for both lists.  We have\r
1436         exclusive access to the ready lists as the scheduler is locked. */\r
1437         vListRemove( ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );\r
1438 \r
1439 \r
1440         #if ( INCLUDE_vTaskSuspend == 1 )\r
1441         {                       \r
1442                 if( xTicksToWait == portMAX_DELAY )\r
1443                 {\r
1444                         /* Add ourselves to the suspended task list instead of a delayed task\r
1445                         list to ensure we are not woken by a timing event.  We will block\r
1446                         indefinitely. */\r
1447                         vListInsertEnd( ( xList * ) &xSuspendedTaskList, ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );\r
1448                 }\r
1449                 else\r
1450                 {\r
1451                         /* Calculate the time at which the task should be woken if the event does\r
1452                         not occur.  This may overflow but this doesn't matter. */\r
1453                         xTimeToWake = xTickCount + xTicksToWait;\r
1454                 \r
1455                         listSET_LIST_ITEM_VALUE( &( pxCurrentTCB->xGenericListItem ), xTimeToWake );\r
1456                 \r
1457                         if( xTimeToWake < xTickCount )\r
1458                         {\r
1459                                 /* Wake time has overflowed.  Place this item in the overflow list. */\r
1460                                 vListInsert( ( xList * ) pxOverflowDelayedTaskList, ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );\r
1461                         }\r
1462                         else\r
1463                         {\r
1464                                 /* The wake time has not overflowed, so we can use the current block list. */\r
1465                                 vListInsert( ( xList * ) pxDelayedTaskList, ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );\r
1466                         }\r
1467                 }\r
1468         }\r
1469         #else\r
1470         {\r
1471                         /* Calculate the time at which the task should be woken if the event does\r
1472                         not occur.  This may overflow but this doesn't matter. */\r
1473                         xTimeToWake = xTickCount + xTicksToWait;\r
1474                 \r
1475                         listSET_LIST_ITEM_VALUE( &( pxCurrentTCB->xGenericListItem ), xTimeToWake );\r
1476                 \r
1477                         if( xTimeToWake < xTickCount )\r
1478                         {\r
1479                                 /* Wake time has overflowed.  Place this item in the overflow list. */\r
1480                                 vListInsert( ( xList * ) pxOverflowDelayedTaskList, ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );\r
1481                         }\r
1482                         else\r
1483                         {\r
1484                                 /* The wake time has not overflowed, so we can use the current block list. */\r
1485                                 vListInsert( ( xList * ) pxDelayedTaskList, ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );\r
1486                         }\r
1487         }\r
1488         #endif\r
1489 }\r
1490 /*-----------------------------------------------------------*/\r
1491 \r
1492 signed portBASE_TYPE xTaskRemoveFromEventList( const xList * const pxEventList )\r
1493 {\r
1494 tskTCB *pxUnblockedTCB;\r
1495 portBASE_TYPE xReturn;\r
1496 \r
1497         /* THIS FUNCTION MUST BE CALLED WITH INTERRUPTS DISABLED OR THE\r
1498         SCHEDULER SUSPENDED.  It can also be called from within an ISR. */\r
1499 \r
1500         /* The event list is sorted in priority order, so we can remove the\r
1501         first in the list, remove the TCB from the delayed list, and add\r
1502         it to the ready list.\r
1503         \r
1504         If an event is for a queue that is locked then this function will never\r
1505         get called - the lock count on the queue will get modified instead.  This\r
1506         means we can always expect exclusive access to the event list here. */\r
1507         pxUnblockedTCB = ( tskTCB * ) listGET_OWNER_OF_HEAD_ENTRY( pxEventList );\r
1508         vListRemove( &( pxUnblockedTCB->xEventListItem ) );\r
1509 \r
1510         if( uxSchedulerSuspended == ( unsigned portBASE_TYPE ) pdFALSE )\r
1511         {\r
1512                 vListRemove( &( pxUnblockedTCB->xGenericListItem ) );\r
1513                 prvAddTaskToReadyQueue( pxUnblockedTCB );\r
1514         }\r
1515         else\r
1516         {\r
1517                 /* We cannot access the delayed or ready lists, so will hold this\r
1518                 task pending until the scheduler is resumed. */\r
1519                 vListInsertEnd( ( xList * ) &( xPendingReadyList ), &( pxUnblockedTCB->xEventListItem ) );\r
1520         }\r
1521 \r
1522         if( pxUnblockedTCB->uxPriority >= pxCurrentTCB->uxPriority )\r
1523         {\r
1524                 /* Return true if the task removed from the event list has\r
1525                 a higher priority than the calling task.  This allows\r
1526                 the calling task to know if it should force a context\r
1527                 switch now. */\r
1528                 xReturn = pdTRUE;\r
1529         }\r
1530         else\r
1531         {\r
1532                 xReturn = pdFALSE;\r
1533         }\r
1534 \r
1535         return xReturn;\r
1536 }\r
1537 /*-----------------------------------------------------------*/\r
1538 \r
1539 void vTaskSetTimeOutState( xTimeOutType * const pxTimeOut )\r
1540 {\r
1541     pxTimeOut->xOverflowCount = xNumOfOverflows;\r
1542     pxTimeOut->xTimeOnEntering = xTickCount;\r
1543 }\r
1544 /*-----------------------------------------------------------*/\r
1545 \r
1546 portBASE_TYPE xTaskCheckForTimeOut( xTimeOutType * const pxTimeOut, portTickType * const pxTicksToWait )\r
1547 {\r
1548 portBASE_TYPE xReturn;\r
1549 \r
1550         portENTER_CRITICAL();\r
1551         {\r
1552                 #if ( INCLUDE_vTaskSuspend == 1 )\r
1553                         /* If INCLUDE_vTaskSuspend is set to 1 and the block time specified is\r
1554                         the maximum block time then the task should block indefinitely, and\r
1555                         therefore never time out. */\r
1556                         if( *pxTicksToWait == portMAX_DELAY )\r
1557                         {\r
1558                                 xReturn = pdFALSE;\r
1559                         }\r
1560                         else /* We are not blocking indefinitely, perform the checks below. */\r
1561                 #endif\r
1562 \r
1563                 if( ( xNumOfOverflows != pxTimeOut->xOverflowCount ) && ( xTickCount >= pxTimeOut->xTimeOnEntering ) )\r
1564                 {\r
1565                         /* The tick count is greater than the time at which vTaskSetTimeout()\r
1566                         was called, but has also overflowed since vTaskSetTimeOut() was called.\r
1567                         It must have wrapped all the way around and gone past us again. This\r
1568                         passed since vTaskSetTimeout() was called. */\r
1569                         xReturn = pdTRUE;\r
1570                 }\r
1571                 else if( ( xTickCount - pxTimeOut->xTimeOnEntering ) < *pxTicksToWait )\r
1572                 {\r
1573                         /* Not a genuine timeout. Adjust parameters for time remaining. */\r
1574                         *pxTicksToWait -= ( xTickCount - pxTimeOut->xTimeOnEntering );\r
1575                         vTaskSetTimeOutState( pxTimeOut );\r
1576                         xReturn = pdFALSE;\r
1577                 }\r
1578                 else\r
1579                 {\r
1580                         xReturn = pdTRUE;\r
1581                 }\r
1582         }\r
1583         portEXIT_CRITICAL();\r
1584 \r
1585     return xReturn;\r
1586 }\r
1587 /*-----------------------------------------------------------*/\r
1588 \r
1589 void vTaskMissedYield( void )\r
1590 {\r
1591         xMissedYield = pdTRUE;\r
1592 }\r
1593 \r
1594 /*\r
1595  * -----------------------------------------------------------\r
1596  * The Idle task.\r
1597  * ----------------------------------------------------------\r
1598  *\r
1599  * The portTASK_FUNCTION() macro is used to allow port/compiler specific\r
1600  * language extensions.  The equivalent prototype for this function is:\r
1601  *\r
1602  * void prvIdleTask( void *pvParameters );\r
1603  *\r
1604  */\r
1605 static portTASK_FUNCTION( prvIdleTask, pvParameters )\r
1606 {\r
1607         /* Stop warnings. */\r
1608         ( void ) pvParameters;\r
1609 \r
1610         for( ;; )\r
1611         {\r
1612                 /* See if any tasks have been deleted. */\r
1613                 prvCheckTasksWaitingTermination();\r
1614 \r
1615                 #if ( configUSE_PREEMPTION == 0 )\r
1616                 {\r
1617                         /* If we are not using preemption we keep forcing a task switch to\r
1618                         see if any other task has become available.  If we are using\r
1619                         preemption we don't need to do this as any task becoming available\r
1620                         will automatically get the processor anyway. */\r
1621                         taskYIELD();    \r
1622                 }\r
1623                 #endif\r
1624 \r
1625                 #if ( ( configUSE_PREEMPTION == 1 ) && ( configIDLE_SHOULD_YIELD == 1 ) )\r
1626                 {\r
1627                         /* When using preemption tasks of equal priority will be\r
1628                         timesliced.  If a task that is sharing the idle priority is ready\r
1629                         to run then the idle task should yield before the end of the\r
1630                         timeslice.\r
1631                         \r
1632                         A critical region is not required here as we are just reading from\r
1633                         the list, and an occasional incorrect value will not matter.  If\r
1634                         the ready list at the idle priority contains more than one task\r
1635                         then a task other than the idle task is ready to execute. */\r
1636                         if( listCURRENT_LIST_LENGTH( &( pxReadyTasksLists[ tskIDLE_PRIORITY ] ) ) > ( unsigned portBASE_TYPE ) 1 )\r
1637                         {\r
1638                                 taskYIELD();\r
1639                         }\r
1640                 }\r
1641                 #endif\r
1642 \r
1643                 #if ( configUSE_IDLE_HOOK == 1 )\r
1644                 {\r
1645                         extern void vApplicationIdleHook( void );\r
1646 \r
1647                         /* Call the user defined function from within the idle task.  This\r
1648                         allows the application designer to add background functionality\r
1649                         without the overhead of a separate task.\r
1650                         NOTE: vApplicationIdleHook() MUST NOT, UNDER ANY CIRCUMSTANCES,\r
1651                         CALL A FUNCTION THAT MIGHT BLOCK. */\r
1652                         vApplicationIdleHook();\r
1653                 }\r
1654                 #endif\r
1655         }\r
1656 } /*lint !e715 pvParameters is not accessed but all task functions require the same prototype. */\r
1657 \r
1658 \r
1659 \r
1660 \r
1661 \r
1662 \r
1663 \r
1664 /*-----------------------------------------------------------\r
1665  * File private functions documented at the top of the file.\r
1666  *----------------------------------------------------------*/\r
1667 \r
1668 \r
1669 \r
1670 static void prvInitialiseTCBVariables( tskTCB *pxTCB, const signed portCHAR * const pcName, unsigned portBASE_TYPE uxPriority )\r
1671 {\r
1672         /* Store the function name in the TCB. */\r
1673         strncpy( ( char * ) pxTCB->pcTaskName, ( const char * ) pcName, ( unsigned portSHORT ) configMAX_TASK_NAME_LEN );\r
1674         pxTCB->pcTaskName[ ( unsigned portSHORT ) configMAX_TASK_NAME_LEN - ( unsigned portSHORT ) 1 ] = '\0';\r
1675 \r
1676         /* This is used as an array index so must ensure it's not too large. */\r
1677         if( uxPriority >= configMAX_PRIORITIES )\r
1678         {\r
1679                 uxPriority = configMAX_PRIORITIES - 1;\r
1680         }\r
1681 \r
1682         pxTCB->uxPriority = uxPriority;\r
1683         #if ( configUSE_MUTEXES == 1 )\r
1684         {\r
1685                 pxTCB->uxBasePriority = uxPriority;\r
1686         }\r
1687         #endif\r
1688 \r
1689         vListInitialiseItem( &( pxTCB->xGenericListItem ) );\r
1690         vListInitialiseItem( &( pxTCB->xEventListItem ) );\r
1691 \r
1692         /* Set the pxTCB as a link back from the xListItem.  This is so we can get\r
1693         back to the containing TCB from a generic item in a list. */\r
1694         listSET_LIST_ITEM_OWNER( &( pxTCB->xGenericListItem ), pxTCB );\r
1695 \r
1696         /* Event lists are always in priority order. */\r
1697         listSET_LIST_ITEM_VALUE( &( pxTCB->xEventListItem ), configMAX_PRIORITIES - ( portTickType ) uxPriority );\r
1698         listSET_LIST_ITEM_OWNER( &( pxTCB->xEventListItem ), pxTCB );\r
1699 \r
1700         #if ( portCRITICAL_NESTING_IN_TCB == 1 )\r
1701         {\r
1702                 pxTCB->uxCriticalNesting = ( unsigned portBASE_TYPE ) 0;\r
1703         }\r
1704         #endif\r
1705 \r
1706         #if ( configUSE_APPLICATION_TASK_TAG == 1 )\r
1707         {\r
1708                 pxTCB->pxTaskTag = NULL;\r
1709         }\r
1710         #endif  \r
1711 }\r
1712 /*-----------------------------------------------------------*/\r
1713 \r
1714 static void prvInitialiseTaskLists( void )\r
1715 {\r
1716 unsigned portBASE_TYPE uxPriority;\r
1717 \r
1718         for( uxPriority = 0; uxPriority < configMAX_PRIORITIES; uxPriority++ )\r
1719         {\r
1720                 vListInitialise( ( xList * ) &( pxReadyTasksLists[ uxPriority ] ) );\r
1721         }\r
1722 \r
1723         vListInitialise( ( xList * ) &xDelayedTaskList1 );\r
1724         vListInitialise( ( xList * ) &xDelayedTaskList2 );\r
1725         vListInitialise( ( xList * ) &xPendingReadyList );\r
1726 \r
1727         #if ( INCLUDE_vTaskDelete == 1 )\r
1728         {\r
1729                 vListInitialise( ( xList * ) &xTasksWaitingTermination );\r
1730         }\r
1731         #endif\r
1732 \r
1733         #if ( INCLUDE_vTaskSuspend == 1 )\r
1734         {\r
1735                 vListInitialise( ( xList * ) &xSuspendedTaskList );\r
1736         }\r
1737         #endif\r
1738 \r
1739         /* Start with pxDelayedTaskList using list1 and the pxOverflowDelayedTaskList\r
1740         using list2. */\r
1741         pxDelayedTaskList = &xDelayedTaskList1;\r
1742         pxOverflowDelayedTaskList = &xDelayedTaskList2;\r
1743 }\r
1744 /*-----------------------------------------------------------*/\r
1745 \r
1746 static void prvCheckTasksWaitingTermination( void )\r
1747 {                                                       \r
1748         #if ( INCLUDE_vTaskDelete == 1 )\r
1749         {                               \r
1750                 portBASE_TYPE xListIsEmpty;\r
1751 \r
1752                 /* ucTasksDeleted is used to prevent vTaskSuspendAll() being called\r
1753                 too often in the idle task. */\r
1754                 if( uxTasksDeleted > ( unsigned portBASE_TYPE ) 0 )\r
1755                 {\r
1756                         vTaskSuspendAll();\r
1757                                 xListIsEmpty = listLIST_IS_EMPTY( &xTasksWaitingTermination );                          \r
1758                         xTaskResumeAll();\r
1759 \r
1760                         if( !xListIsEmpty )\r
1761                         {\r
1762                                 tskTCB *pxTCB;\r
1763 \r
1764                                 portENTER_CRITICAL();\r
1765                                 {                       \r
1766                                         pxTCB = ( tskTCB * ) listGET_OWNER_OF_HEAD_ENTRY( ( ( xList * ) &xTasksWaitingTermination ) );\r
1767                                         vListRemove( &( pxTCB->xGenericListItem ) );\r
1768                                         --uxCurrentNumberOfTasks;\r
1769                                         --uxTasksDeleted;\r
1770                                 }\r
1771                                 portEXIT_CRITICAL();\r
1772 \r
1773                                 prvDeleteTCB( pxTCB );\r
1774                         }\r
1775                 }\r
1776         }\r
1777         #endif\r
1778 }\r
1779 /*-----------------------------------------------------------*/\r
1780 \r
1781 static tskTCB *prvAllocateTCBAndStack( unsigned portSHORT usStackDepth )\r
1782 {\r
1783 tskTCB *pxNewTCB;\r
1784 \r
1785         /* Allocate space for the TCB.  Where the memory comes from depends on\r
1786         the implementation of the port malloc function. */\r
1787         pxNewTCB = ( tskTCB * ) pvPortMalloc( sizeof( tskTCB ) );\r
1788 \r
1789         if( pxNewTCB != NULL )\r
1790         {\r
1791                 /* Allocate space for the stack used by the task being created.\r
1792                 The base of the stack memory stored in the TCB so the task can\r
1793                 be deleted later if required. */\r
1794                 pxNewTCB->pxStack = ( portSTACK_TYPE * ) pvPortMalloc( ( ( size_t )usStackDepth ) * sizeof( portSTACK_TYPE ) );\r
1795 \r
1796                 if( pxNewTCB->pxStack == NULL )\r
1797                 {\r
1798                         /* Could not allocate the stack.  Delete the allocated TCB. */\r
1799                         vPortFree( pxNewTCB );                  \r
1800                         pxNewTCB = NULL;                        \r
1801                 }               \r
1802                 else\r
1803                 {\r
1804                         /* Just to help debugging. */\r
1805                         memset( pxNewTCB->pxStack, tskSTACK_FILL_BYTE, usStackDepth * sizeof( portSTACK_TYPE ) );\r
1806                 }\r
1807         }\r
1808 \r
1809         return pxNewTCB;\r
1810 }\r
1811 /*-----------------------------------------------------------*/\r
1812 \r
1813 #if ( configUSE_TRACE_FACILITY == 1 )\r
1814 \r
1815         static void prvListTaskWithinSingleList( const signed portCHAR *pcWriteBuffer, xList *pxList, signed portCHAR cStatus )\r
1816         {\r
1817         volatile tskTCB *pxNextTCB, *pxFirstTCB;\r
1818         unsigned portSHORT usStackRemaining;\r
1819 \r
1820                 /* Write the details of all the TCB's in pxList into the buffer. */\r
1821                 listGET_OWNER_OF_NEXT_ENTRY( pxFirstTCB, pxList );\r
1822                 do\r
1823                 {\r
1824                         listGET_OWNER_OF_NEXT_ENTRY( pxNextTCB, pxList );\r
1825                         usStackRemaining = usTaskCheckFreeStackSpace( ( unsigned portCHAR * ) pxNextTCB->pxStack );\r
1826                         sprintf( pcStatusString, ( portCHAR * ) "%s\t\t%c\t%u\t%u\t%u\r\n", pxNextTCB->pcTaskName, cStatus, ( unsigned int ) pxNextTCB->uxPriority, usStackRemaining, ( unsigned int ) pxNextTCB->uxTCBNumber );\r
1827                         strcat( ( portCHAR * ) pcWriteBuffer, ( portCHAR * ) pcStatusString );\r
1828 \r
1829                 } while( pxNextTCB != pxFirstTCB );\r
1830         }\r
1831 \r
1832 #endif\r
1833 /*-----------------------------------------------------------*/\r
1834 \r
1835 #if ( INCLUDE_uxTaskGetStackHighWaterMark == 1 )\r
1836 \r
1837         unsigned portSHORT usTaskCheckFreeStackSpace( const unsigned portCHAR * pucStackByte )\r
1838         {\r
1839         register unsigned portSHORT usCount = 0;\r
1840 \r
1841                 while( *pucStackByte == tskSTACK_FILL_BYTE )\r
1842                 {\r
1843                         pucStackByte -= portSTACK_GROWTH;\r
1844                         usCount++;\r
1845                 }\r
1846 \r
1847                 usCount /= sizeof( portSTACK_TYPE );\r
1848 \r
1849                 return usCount;\r
1850         }\r
1851 \r
1852 #endif\r
1853 /*-----------------------------------------------------------*/\r
1854 \r
1855 #if ( INCLUDE_uxTaskGetStackHighWaterMark == 1 )\r
1856 \r
1857         unsigned portBASE_TYPE uxTaskGetStackHighWaterMark( xTaskHandle xTask )\r
1858         {\r
1859         tskTCB *pxTCB;\r
1860         unsigned portCHAR *pcEndOfStack;\r
1861 \r
1862                 pxTCB = prvGetTCBFromHandle( xTask );\r
1863 \r
1864                 #if portSTACK_GROWTH < 0\r
1865                 {\r
1866                         pcEndOfStack = ( unsigned portCHAR * ) pxTCB->pxStack;\r
1867                 }\r
1868                 #else\r
1869                 {\r
1870                         pcEndOfStack = ( unsigned portCHAR * ) pxTCB->pxEndOfStack;\r
1871                 }\r
1872                 #endif\r
1873 \r
1874                 return usTaskCheckFreeStackSpace( pcEndOfStack );\r
1875         }\r
1876 \r
1877 #endif\r
1878 /*-----------------------------------------------------------*/\r
1879 \r
1880 #if ( ( INCLUDE_vTaskDelete == 1 ) || ( INCLUDE_vTaskCleanUpResources == 1 ) )\r
1881 \r
1882         static void prvDeleteTCB( tskTCB *pxTCB )\r
1883         {\r
1884                 /* Free up the memory allocated by the scheduler for the task.  It is up to\r
1885                 the task to free any memory allocated at the application level. */\r
1886                 vPortFree( pxTCB->pxStack );\r
1887                 vPortFree( pxTCB );\r
1888         }\r
1889 \r
1890 #endif\r
1891 \r
1892 \r
1893 /*-----------------------------------------------------------*/\r
1894 \r
1895 #if ( INCLUDE_xTaskGetCurrentTaskHandle == 1 )\r
1896 \r
1897         xTaskHandle xTaskGetCurrentTaskHandle( void )\r
1898         {\r
1899         xTaskHandle xReturn;\r
1900 \r
1901                 portENTER_CRITICAL();\r
1902                 {\r
1903                         xReturn = ( xTaskHandle ) pxCurrentTCB;\r
1904                 }\r
1905                 portEXIT_CRITICAL();\r
1906 \r
1907                 return xReturn;\r
1908         }\r
1909 \r
1910 #endif\r
1911 \r
1912 /*-----------------------------------------------------------*/\r
1913 \r
1914 #if ( INCLUDE_xTaskGetSchedulerState == 1 )\r
1915 \r
1916         portBASE_TYPE xTaskGetSchedulerState( void )\r
1917         {\r
1918         portBASE_TYPE xReturn;\r
1919         \r
1920                 if( xSchedulerRunning == pdFALSE )\r
1921                 {\r
1922                         xReturn = taskSCHEDULER_NOT_STARTED;\r
1923                 }\r
1924                 else\r
1925                 {\r
1926                         if( uxSchedulerSuspended == ( unsigned portBASE_TYPE ) pdFALSE )\r
1927                         {\r
1928                                 xReturn = taskSCHEDULER_RUNNING;\r
1929                         }\r
1930                         else\r
1931                         {\r
1932                                 xReturn = taskSCHEDULER_SUSPENDED;\r
1933                         }\r
1934                 }\r
1935                 \r
1936                 return xReturn;\r
1937         }\r
1938 \r
1939 #endif\r
1940 /*-----------------------------------------------------------*/\r
1941 \r
1942 #if ( configUSE_MUTEXES == 1 )\r
1943         \r
1944         void vTaskPriorityInherit( xTaskHandle * const pxMutexHolder )\r
1945         {\r
1946         tskTCB * const pxTCB = ( tskTCB * ) pxMutexHolder;\r
1947 \r
1948                 if( pxTCB->uxPriority < pxCurrentTCB->uxPriority )\r
1949                 {\r
1950                         /* Adjust the mutex holder state to account for its new priority. */\r
1951                         listSET_LIST_ITEM_VALUE( &( pxTCB->xEventListItem ), configMAX_PRIORITIES - ( portTickType ) pxCurrentTCB->uxPriority );\r
1952 \r
1953                         /* If the task being modified is in the ready state it will need to\r
1954                         be moved in to a new list. */\r
1955                         if( listIS_CONTAINED_WITHIN( &( pxReadyTasksLists[ pxTCB->uxPriority ] ), &( pxTCB->xGenericListItem ) ) )\r
1956                         {\r
1957                                 vListRemove( &( pxTCB->xGenericListItem ) );\r
1958 \r
1959                                 /* Inherit the priority before being moved into the new list. */\r
1960                                 pxTCB->uxPriority = pxCurrentTCB->uxPriority;\r
1961                                 prvAddTaskToReadyQueue( pxTCB );\r
1962                         }\r
1963                         else\r
1964                         {\r
1965                                 /* Just inherit the priority. */\r
1966                                 pxTCB->uxPriority = pxCurrentTCB->uxPriority;\r
1967                         }\r
1968                 }\r
1969         }\r
1970 \r
1971 #endif\r
1972 /*-----------------------------------------------------------*/\r
1973 \r
1974 #if ( configUSE_MUTEXES == 1 )  \r
1975 \r
1976         void vTaskPriorityDisinherit( xTaskHandle * const pxMutexHolder )\r
1977         {\r
1978         tskTCB * const pxTCB = ( tskTCB * ) pxMutexHolder;\r
1979 \r
1980                 if( pxMutexHolder != NULL )\r
1981                 {\r
1982                         if( pxTCB->uxPriority != pxTCB->uxBasePriority )\r
1983                         {\r
1984                                 /* We must be the running task to be able to give the mutex back.\r
1985                                 Remove ourselves from the ready list we currently appear in. */\r
1986                                 vListRemove( &( pxTCB->xGenericListItem ) );\r
1987 \r
1988                                 /* Disinherit the priority before adding ourselves into the new\r
1989                                 ready list. */\r
1990                                 pxTCB->uxPriority = pxTCB->uxBasePriority;\r
1991                                 listSET_LIST_ITEM_VALUE( &( pxTCB->xEventListItem ), configMAX_PRIORITIES - ( portTickType ) pxTCB->uxPriority );\r
1992                                 prvAddTaskToReadyQueue( pxTCB );\r
1993                         }\r
1994                 }\r
1995         }\r
1996 \r
1997 #endif\r
1998 /*-----------------------------------------------------------*/\r
1999 \r
2000 #if ( portCRITICAL_NESTING_IN_TCB == 1 )\r
2001 \r
2002         void vTaskEnterCritical( void )\r
2003         {\r
2004                 portDISABLE_INTERRUPTS();\r
2005 \r
2006                 if( xSchedulerRunning != pdFALSE )\r
2007                 {\r
2008                         pxCurrentTCB->uxCriticalNesting++;\r
2009                 }\r
2010         }\r
2011 \r
2012 #endif\r
2013 /*-----------------------------------------------------------*/\r
2014 \r
2015 #if ( portCRITICAL_NESTING_IN_TCB == 1 )\r
2016 \r
2017 void vTaskExitCritical( void )\r
2018 {\r
2019         if( xSchedulerRunning != pdFALSE )\r
2020         {\r
2021                 if( pxCurrentTCB->uxCriticalNesting > 0 )\r
2022                 {\r
2023                         pxCurrentTCB->uxCriticalNesting--;\r
2024 \r
2025                         if( pxCurrentTCB->uxCriticalNesting == 0 )\r
2026                         {\r
2027                                 portENABLE_INTERRUPTS();\r
2028                         }\r
2029                 }\r
2030         }\r
2031 }\r
2032 \r
2033 #endif\r
2034 /*-----------------------------------------------------------*/\r
2035 \r
2036 \r
2037         \r
2038 \r