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

   1 /*\r
   2         FreeRTOS V4.0.1 - Copyright (C) 2003-2006 Richard Barry.\r
   3 \r
   4         This file is part of the FreeRTOS distribution.\r
   5 \r
   6         FreeRTOS 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 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; 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, 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         See http://www.FreeRTOS.org for documentation, latest information, license\r
  28         and contact details.  Please ensure to read the configuration and relevant\r
  29         port sections of the online documentation.\r
  30         ***************************************************************************\r
  31 */\r
  32 \r
  33 /*\r
  34 Changes from V1.00:\r
  35         \r
  36         + Call to portRESTORE_CONTEXT has been removed.  The first context\r
  37           switch is now performed within sPortStartScheduler().\r
  38 \r
  39 Changes from V1.01:\r
  40 \r
  41         + More use of 8bit data types.\r
  42         + Function name prefixes changed where the data type returned has changed.\r
  43         + configUSE_TRACE_FACILITY is no longer defined by default.\r
  44 \r
  45 Changes from V1.2.0\r
  46 \r
  47         + Introduced ucTopReadyPriority.  This tracks the highest priority ready\r
  48           queue that contains a valid TCB and thus makes the context switch\r
  49           slightly faster.\r
  50 \r
  51         + prvAddTaskToReadyQueue() has been made a macro.\r
  52 \r
  53 Changes from V1.2.6\r
  54 \r
  55         + Added conditional compilation directives.\r
  56         + Extended API.\r
  57         + Rearranged function order.\r
  58         + Creating a task now causes a context switch if the task being created\r
  59           has a higher priority than the calling task - assuming the kernel is\r
  60           running.\r
  61         + vTaskDelete() now only causes a context switch if the calling task is\r
  62           the task being deleted.\r
  63 \r
  64 Changes from V2.0.0\r
  65 \r
  66         + Allow the type of the tick count to be 16 or 32 bits.\r
  67         + Introduce xPendingReadyList feature to allow the time interrupts have to\r
  68           be disabled to be minimised.\r
  69         + Remove the #if( INCLUDE_vTaskSuspendAll ) statements.  vTaskSuspendAll()\r
  70           is now always included as it is used by the scheduler itself.\r
  71 \r
  72 Changes from V2.1.0\r
  73 \r
  74         + Bug fix - pxCurrentTCB is now initialised before the call to\r
  75           prvInitializeTaskLists().  Previously pxCurrentTCB could be accessed\r
  76           while null.\r
  77 \r
  78 Changed from V2.1.1\r
  79 \r
  80         + Change to where lStackSize is declared within sTaskCreate() to prevent\r
  81           compiler warnings with 8051 port.\r
  82 \r
  83 Changes from V2.2.0\r
  84 \r
  85         + Explicit use of 'signed' qualifier on portCHAR types added.\r
  86         + Changed odd calculation of initial pxTopOfStack value when\r
  87           portSTACK_GROWTH < 0.\r
  88         + Removed pcVersionNumber definition.\r
  89 \r
  90 Changes from V2.5.3\r
  91 \r
  92         + cTaskResumeAll() modified to ensure it can be called prior to the task\r
  93           lists being initialised.\r
  94 \r
  95 Changes from V2.5.5\r
  96 \r
  97         + Added API function vTaskDelayUntil().\r
  98         + Added INCLUDE_vTaskDelay conditional compilation.\r
  99 \r
 100 Changes from V2.6.0\r
 101 \r
 102         + Updated the vWriteTraceToBuffer macro to always be 4 byte aligned so it\r
 103           can be used on ARM architectures.\r
 104         + tskMAX_TASK_NAME_LEN definition replaced with the port specific\r
 105           configMAX_TASK_NAME_LEN definition.\r
 106         + Removed the call to strcpy when copying across the task name into the\r
 107           TCB.\r
 108         + Added ucTasksDeleted variable to prevent vTaskSuspendAll() being called\r
 109           too often in the idle task.\r
 110 \r
 111 Changes between V3.0.0 and V2.6.1\r
 112 \r
 113         + When resuming the scheduler a yield is performed if either a tick has\r
 114           been missed, or a task is moved from the pending ready list into a ready\r
 115           list.  Previously a yield was not performed on this second condition.\r
 116         + Introduced the type portBASE_TYPE.  This necessitates several API\r
 117           changes.\r
 118         + Removed the sUsingPreemption variable.  The constant defined in\r
 119           portmacro.h is now used directly.\r
 120         + The idle task can now include an optional hook function - and no longer\r
 121           completes its time slice if other tasks with equal priority to it are\r
 122           ready to run.\r
 123         + See the FreeRTOS.org documentation for more information on V2.x.x to\r
 124           V3.x.x modifications.\r
 125 \r
 126 Changes from V3.1.1\r
 127 \r
 128         + Modified vTaskPrioritySet() and vTaskResume() to allow these functions to\r
 129           be called while the scheduler is suspended.\r
 130         + Corrected the task ordering within event lists.\r
 131 \r
 132 Changes from V3.2.0\r
 133 \r
 134         + Added function xTaskGetCurrentTaskHandle().\r
 135 \r
 136 Changes from V3.2.4\r
 137 \r
 138         + Changed the volatile declarations on some variables to reflect the \r
 139           changes to the list definitions.\r
 140         + Changed the order of the TCB definition so there is commonality between\r
 141           the task control block and a co-routine control block.\r
 142         + Allow the scheduler to be started even if no tasks other than the idle\r
 143           task has been created.  This allows co-routines to run even when no tasks\r
 144           have been created.\r
 145         + The need for a context switch is now signalled if a task woken by an \r
 146           event has a priority greater or equal to the currently running task.\r
 147           Previously this was only greater than.\r
 148 \r
 149 Changes from V4.0.0\r
 150 \r
 151         + Added the xMissedYield handling.\r
 152 */\r
 153 \r
 154 #include <stdio.h>\r
 155 #include <stdlib.h>\r
 156 #include <string.h>\r
 157 \r
 158 #include "FreeRTOS.h"\r
 159 #include "task.h"\r
 160 \r
 161 /*\r
 162  * Macro to define the amount of stack available to the idle task.\r
 163  */\r
 164 #define tskIDLE_STACK_SIZE      configMINIMAL_STACK_SIZE\r
 165 \r
 166 \r
 167 /*\r
 168  * Default a definitions for backwards compatibility with old\r
 169  * portmacro.h files.\r
 170  */\r
 171 #ifndef configMAX_TASK_NAME_LEN\r
 172         #define configMAX_TASK_NAME_LEN 16\r
 173 #endif\r
 174 \r
 175 #ifndef INCLUDE_xTaskGetCurrentTaskHandle\r
 176         #define INCLUDE_xTaskGetCurrentTaskHandle 0\r
 177 #endif\r
 178 \r
 179 #ifndef configIDLE_SHOULD_YIELD\r
 180         #define configIDLE_SHOULD_YIELD         1\r
 181 #endif\r
 182 \r
 183 #if configMAX_TASK_NAME_LEN < 1\r
 184         #undef configMAX_TASK_NAME_LEN\r
 185         #define configMAX_TASK_NAME_LEN 1\r
 186 #endif\r
 187 \r
 188 \r
 189 /*\r
 190  * Task control block.  A task control block (TCB) is allocated to each task,\r
 191  * and stores the context of the task.\r
 192  */\r
 193 typedef struct tskTaskControlBlock\r
 194 {\r
 195         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
 196         xListItem                               xGenericListItem;       /*< List item used to place the TCB in ready and blocked queues. */\r
 197         xListItem                               xEventListItem;         /*< List item used to place the TCB in event lists. */\r
 198         unsigned portBASE_TYPE  uxPriority;                     /*< The priority of the task where 0 is the lowest priority. */\r
 199         portSTACK_TYPE                  *pxStack;                       /*< Points to the start of the stack. */\r
 200         unsigned portBASE_TYPE  uxTCBNumber;            /*< This is used for tracing the scheduler and making debugging easier only. */\r
 201         signed portCHAR                 pcTaskName[ configMAX_TASK_NAME_LEN ];/*< Descriptive name given to the task when created.  Facilitates debugging only. */\r
 202         unsigned portSHORT              usStackDepth;           /*< Total depth of the stack (when empty).  This is defined as the number of variables the stack can hold, not the number of bytes. */\r
 203 } tskTCB;\r
 204 \r
 205 /*lint -e956 */\r
 206 \r
 207 tskTCB * volatile pxCurrentTCB = NULL;                                  \r
 208 \r
 209 /* Lists for ready and blocked tasks. --------------------*/\r
 210 \r
 211 static xList pxReadyTasksLists[ configMAX_PRIORITIES ]; /*< Prioritised ready tasks. */\r
 212 static xList xDelayedTaskList1;                                                 /*< Delayed tasks. */\r
 213 static xList xDelayedTaskList2;                                                 /*< Delayed tasks (two lists are used - one for delays that have overflowed the current tick count. */\r
 214 static xList * volatile pxDelayedTaskList;                              /*< Points to the delayed task list currently being used. */\r
 215 static xList * volatile pxOverflowDelayedTaskList;              /*< Points to the delayed task list currently being used to hold tasks that have overflowed the current tick count. */\r
 216 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
 217 \r
 218 #if ( INCLUDE_vTaskDelete == 1 )\r
 219 \r
 220         static volatile xList xTasksWaitingTermination;         /*< Tasks that have been deleted - but the their memory not yet freed. */\r
 221         static volatile unsigned portBASE_TYPE uxTasksDeleted = ( unsigned portBASE_TYPE ) 0;\r
 222 \r
 223 #endif\r
 224 \r
 225 #if ( INCLUDE_vTaskSuspend == 1 )\r
 226 \r
 227         static xList xSuspendedTaskList;                                        /*< Tasks that are currently suspended. */\r
 228 \r
 229 #endif\r
 230 \r
 231 /* File private variables. --------------------------------*/\r
 232 static volatile unsigned portBASE_TYPE uxCurrentNumberOfTasks   = ( unsigned portBASE_TYPE ) 0;\r
 233 static volatile portTickType xTickCount                                                 = ( portTickType ) 0;\r
 234 static unsigned portBASE_TYPE uxTopUsedPriority                         = tskIDLE_PRIORITY;\r
 235 static volatile unsigned portBASE_TYPE uxTopReadyPriority               = tskIDLE_PRIORITY;\r
 236 static volatile signed portBASE_TYPE xSchedulerRunning                  = pdFALSE;\r
 237 static volatile unsigned portBASE_TYPE uxSchedulerSuspended             = ( unsigned portBASE_TYPE ) pdFALSE;\r
 238 static volatile unsigned portBASE_TYPE uxMissedTicks                    = ( unsigned portBASE_TYPE ) 0;\r
 239 static volatile portBASE_TYPE xMissedYield                                              = ( portBASE_TYPE ) pdFALSE;\r
 240 \r
 241 /* Debugging and trace facilities private variables and macros. ------------*/\r
 242 \r
 243 /*\r
 244  * The value used to fill the stack of a task when the task is created.  This\r
 245  * is used purely for checking the high water mark for tasks.\r
 246  */\r
 247 #define tskSTACK_FILL_BYTE      ( 0xa5 )\r
 248 \r
 249 /*\r
 250  * Macros used by vListTask to indicate which state a task is in.\r
 251  */\r
 252 #define tskBLOCKED_CHAR         ( ( signed portCHAR ) 'B' )\r
 253 #define tskREADY_CHAR           ( ( signed portCHAR ) 'R' )\r
 254 #define tskDELETED_CHAR         ( ( signed portCHAR ) 'D' )\r
 255 #define tskSUSPENDED_CHAR       ( ( signed portCHAR ) 'S' )\r
 256 \r
 257 /*\r
 258  * Macros and private variables used by the trace facility.\r
 259  */\r
 260 #if ( configUSE_TRACE_FACILITY == 1 )\r
 261 \r
 262         #define tskSIZE_OF_EACH_TRACE_LINE                      ( ( unsigned portLONG ) ( sizeof( unsigned portLONG ) + sizeof( unsigned portLONG ) ) )\r
 263         static volatile signed portCHAR * volatile pcTraceBuffer;\r
 264         static signed portCHAR *pcTraceBufferStart;\r
 265         static signed portCHAR *pcTraceBufferEnd;\r
 266         static signed portBASE_TYPE xTracing = pdFALSE;\r
 267 \r
 268 #endif\r
 269 \r
 270 /*\r
 271  * Macro that writes a trace of scheduler activity to a buffer.  This trace\r
 272  * shows which task is running when and is very useful as a debugging tool.\r
 273  * As this macro is called each context switch it is a good idea to undefine\r
 274  * it if not using the facility.\r
 275  */\r
 276 #if ( configUSE_TRACE_FACILITY == 1 )\r
 277 \r
 278         #define vWriteTraceToBuffer()                                                                                                           \\r
 279         {                                                                                                                                                                       \\r
 280                 if( xTracing )                                                                                                                                  \\r
 281                 {                                                                                                                                                               \\r
 282                         static unsigned portBASE_TYPE uxPreviousTask = 255;                                                     \\r
 283                                                                                                                                                                                 \\r
 284                         if( uxPreviousTask != pxCurrentTCB->uxTCBNumber )                                                       \\r
 285                         {                                                                                                                                                       \\r
 286                                 if( ( pcTraceBuffer + tskSIZE_OF_EACH_TRACE_LINE ) < pcTraceBufferEnd ) \\r
 287                                 {                                                                                                                                               \\r
 288                                         uxPreviousTask = pxCurrentTCB->uxTCBNumber;                                                     \\r
 289                                         *( unsigned portLONG * ) pcTraceBuffer = ( unsigned portLONG ) xTickCount;              \\r
 290                                         pcTraceBuffer += sizeof( unsigned portLONG );                                           \\r
 291                                         *( unsigned portLONG * ) pcTraceBuffer = ( unsigned portLONG ) uxPreviousTask;  \\r
 292                                         pcTraceBuffer += sizeof( unsigned portLONG );                                           \\r
 293                                 }                                                                                                                                               \\r
 294                                 else                                                                                                                                    \\r
 295                                 {                                                                                                                                               \\r
 296                                         xTracing = pdFALSE;                                                                                                     \\r
 297                                 }                                                                                                                                               \\r
 298                         }                                                                                                                                                       \\r
 299                 }                                                                                                                                                               \\r
 300         }\r
 301 \r
 302 #else\r
 303 \r
 304         #define vWriteTraceToBuffer()\r
 305 \r
 306 #endif\r
 307 \r
 308 \r
 309 /*\r
 310  * Place the task represented by pxTCB into the appropriate ready queue for\r
 311  * the task.  It is inserted at the end of the list.  One quirk of this is\r
 312  * that if the task being inserted is at the same priority as the currently\r
 313  * executing task, then it will only be rescheduled after the currently\r
 314  * executing task has been rescheduled.\r
 315  */\r
 316 #define prvAddTaskToReadyQueue( pxTCB )                                                                                                                                                 \\r
 317 {                                                                                                                                                                                                                               \\r
 318         if( pxTCB->uxPriority > uxTopReadyPriority )                                                                                                                            \\r
 319         {                                                                                                                                                                                                                       \\r
 320                 uxTopReadyPriority = pxTCB->uxPriority;                                                                                                                                 \\r
 321         }                                                                                                                                                                                                                       \\r
 322         vListInsertEnd( ( xList * ) &( pxReadyTasksLists[ pxTCB->uxPriority ] ), &( pxTCB->xGenericListItem ) );        \\r
 323 }       \r
 324 \r
 325 \r
 326 /*\r
 327  * Macro that looks at the list of tasks that are currently delayed to see if\r
 328  * any require waking.\r
 329  *\r
 330  * Tasks are stored in the queue in the order of their wake time - meaning\r
 331  * once one tasks has been found whose timer has not expired we need not look\r
 332  * any further down the list.\r
 333  */\r
 334 #define prvCheckDelayedTasks()                                                                                                                                  \\r
 335 {                                                                                                                                                                                               \\r
 336 register tskTCB *pxTCB;                                                                                                                                                 \\r
 337                                                                                                                                                                                                 \\r
 338         while( ( pxTCB = ( tskTCB * ) listGET_OWNER_OF_HEAD_ENTRY( pxDelayedTaskList ) ) != NULL )      \\r
 339         {                                                                                                                                                                                       \\r
 340                 if( xTickCount < listGET_LIST_ITEM_VALUE( &( pxTCB->xGenericListItem ) ) )                              \\r
 341                 {                                                                                                                                                                               \\r
 342                         break;                                                                                                                                                          \\r
 343                 }                                                                                                                                                                               \\r
 344                 vListRemove( &( pxTCB->xGenericListItem ) );                                                                                    \\r
 345                 /* Is the task waiting on an event also? */                                                                                             \\r
 346                 if( pxTCB->xEventListItem.pvContainer )                                                                                                 \\r
 347                 {                                                                                                                                                                               \\r
 348                         vListRemove( &( pxTCB->xEventListItem ) );                                                                                      \\r
 349                 }                                                                                                                                                                               \\r
 350                 prvAddTaskToReadyQueue( pxTCB );                                                                                                                \\r
 351         }                                                                                                                                                                                       \\r
 352 }                                                                                                                                                                                       \r
 353 \r
 354 /*\r
 355  * Several functions take an xTaskHandle parameter that can optionally be NULL,\r
 356  * where NULL is used to indicate that the handle of the currently executing\r
 357  * task should be used in place of the parameter.  This macro simply checks to\r
 358  * see if the parameter is NULL and returns a pointer to the appropriate TCB.\r
 359  */\r
 360 #define prvGetTCBFromHandle( pxHandle ) ( ( pxHandle == NULL ) ? ( tskTCB * ) pxCurrentTCB : ( tskTCB * ) pxHandle )\r
 361 \r
 362 \r
 363 /* File private functions. --------------------------------*/\r
 364 \r
 365 /*\r
 366  * Utility to ready a TCB for a given task.  Mainly just copies the parameters\r
 367  * into the TCB structure.\r
 368  */\r
 369 static void prvInitialiseTCBVariables( tskTCB *pxTCB, unsigned portSHORT usStackDepth, const signed portCHAR * const pcName, unsigned portBASE_TYPE uxPriority );\r
 370 \r
 371 /*\r
 372  * Utility to ready all the lists used by the scheduler.  This is called\r
 373  * automatically upon the creation of the first task.\r
 374  */\r
 375 static void prvInitialiseTaskLists( void );\r
 376 \r
 377 /*\r
 378  * The idle task, which as all tasks is implemented as a never ending loop.\r
 379  * The idle task is automatically created and added to the ready lists upon\r
 380  * creation of the first user task.\r
 381  *\r
 382  * The portTASK_FUNCTION_PROTO() macro is used to allow port/compiler specific\r
 383  * language extensions.  The equivalent prototype for this function is:\r
 384  *\r
 385  * void prvIdleTask( void *pvParameters );\r
 386  *\r
 387  */\r
 388 static portTASK_FUNCTION_PROTO( prvIdleTask, pvParameters );\r
 389 \r
 390 /*\r
 391  * Utility to free all memory allocated by the scheduler to hold a TCB,\r
 392  * including the stack pointed to by the TCB.\r
 393  *\r
 394  * This does not free memory allocated by the task itself (i.e. memory\r
 395  * allocated by calls to pvPortMalloc from within the tasks application code).\r
 396  */\r
 397 #if ( ( INCLUDE_vTaskDelete == 1 ) || ( INCLUDE_vTaskCleanUpResources == 1 ) )\r
 398         static void prvDeleteTCB( tskTCB *pxTCB );\r
 399 #endif\r
 400 \r
 401 /*\r
 402  * Used only by the idle task.  This checks to see if anything has been placed\r
 403  * in the list of tasks waiting to be deleted.  If so the task is cleaned up\r
 404  * and its TCB deleted.\r
 405  */\r
 406 static void prvCheckTasksWaitingTermination( void );\r
 407 \r
 408 /*\r
 409  * Allocates memory from the heap for a TCB and associated stack.  Checks the\r
 410  * allocation was successful.\r
 411  */\r
 412 static tskTCB *prvAllocateTCBAndStack( unsigned portSHORT usStackDepth );\r
 413 \r
 414 /*\r
 415  * Called from vTaskList.  vListTasks details all the tasks currently under\r
 416  * control of the scheduler.  The tasks may be in one of a number of lists.\r
 417  * prvListTaskWithinSingleList accepts a list and details the tasks from\r
 418  * within just that list.\r
 419  *\r
 420  * THIS FUNCTION IS INTENDED FOR DEBUGGING ONLY, AND SHOULD NOT BE CALLED FROM\r
 421  * NORMAL APPLICATION CODE.\r
 422  */\r
 423 #if ( configUSE_TRACE_FACILITY == 1 )\r
 424 \r
 425         static void prvListTaskWithinSingleList( signed portCHAR *pcWriteBuffer, xList *pxList, signed portCHAR cStatus );\r
 426 \r
 427 #endif\r
 428 \r
 429 /*\r
 430  * When a task is created, the stack of the task is filled with a known value.\r
 431  * This function determines the 'high water mark' of the task stack by\r
 432  * determining how much of the stack remains at the original preset value.\r
 433  */\r
 434 #if ( configUSE_TRACE_FACILITY == 1 )\r
 435 \r
 436         unsigned portSHORT usTaskCheckFreeStackSpace( const unsigned portCHAR *pucStackByte );\r
 437 \r
 438 #endif\r
 439 \r
 440 /*lint +e956 */\r
 441 \r
 442 \r
 443 \r
 444 \r
 445 \r
 446 /*-----------------------------------------------------------\r
 447  * TASK CREATION API documented in task.h\r
 448  *----------------------------------------------------------*/\r
 449 \r
 450 signed portBASE_TYPE xTaskCreate( pdTASK_CODE pvTaskCode, const signed portCHAR * const pcName, unsigned portSHORT usStackDepth, void *pvParameters, unsigned portBASE_TYPE uxPriority, xTaskHandle *pxCreatedTask )\r
 451 {\r
 452 signed portBASE_TYPE xReturn;\r
 453 tskTCB * pxNewTCB;\r
 454 static unsigned portBASE_TYPE uxTaskNumber = 0; /*lint !e956 Static is deliberate - this is guarded before use. */\r
 455 \r
 456         /* Allocate the memory required by the TCB and stack for the new task.\r
 457         checking that the allocation was successful. */\r
 458         pxNewTCB = prvAllocateTCBAndStack( usStackDepth );\r
 459 \r
 460         if( pxNewTCB != NULL )\r
 461         {               \r
 462                 portSTACK_TYPE *pxTopOfStack;\r
 463 \r
 464                 /* Setup the newly allocated TCB with the initial state of the task. */\r
 465                 prvInitialiseTCBVariables( pxNewTCB, usStackDepth, pcName, uxPriority );\r
 466 \r
 467                 /* Calculate the top of stack address.  This depends on whether the\r
 468                 stack grows from high memory to low (as per the 80x86) or visa versa.\r
 469                 portSTACK_GROWTH is used to make the result positive or negative as\r
 470                 required by the port. */\r
 471                 #if portSTACK_GROWTH < 0\r
 472                 {\r
 473                         pxTopOfStack = pxNewTCB->pxStack + ( pxNewTCB->usStackDepth - 1 );\r
 474                 }\r
 475                 #else\r
 476                 {\r
 477                         pxTopOfStack = pxNewTCB->pxStack;       \r
 478                 }\r
 479                 #endif\r
 480 \r
 481                 /* Initialize the TCB stack to look as if the task was already running,\r
 482                 but had been interrupted by the scheduler.  The return address is set\r
 483                 to the start of the task function. Once the stack has been initialised\r
 484                 the     top of stack variable is updated. */\r
 485                 pxNewTCB->pxTopOfStack = pxPortInitialiseStack( pxTopOfStack, pvTaskCode, pvParameters );\r
 486 \r
 487                 /* We are going to manipulate the task queues to add this task to a\r
 488                 ready list, so must make sure no interrupts occur. */\r
 489                 portENTER_CRITICAL();\r
 490                 {\r
 491                         uxCurrentNumberOfTasks++;\r
 492                         if( uxCurrentNumberOfTasks == ( unsigned portBASE_TYPE ) 1 )\r
 493                         {\r
 494                                 /* As this is the first task it must also be the current task. */\r
 495                                 pxCurrentTCB =  pxNewTCB;\r
 496 \r
 497                                 /* This is the first task to be created so do the preliminary\r
 498                                 initialisation required.  We will not recover if this call\r
 499                                 fails, but we will report the failure. */\r
 500                                 prvInitialiseTaskLists();\r
 501                         }\r
 502                         else\r
 503                         {       \r
 504                                 /* If the scheduler is not already running, make this task the\r
 505                                 current task if it is the highest priority task to be created\r
 506                                 so far. */\r
 507                                 if( xSchedulerRunning == pdFALSE )\r
 508                                 {\r
 509                                         if( pxCurrentTCB->uxPriority <= uxPriority )\r
 510                                         {\r
 511                                                 pxCurrentTCB = pxNewTCB;        \r
 512                                         }\r
 513                                 }\r
 514                         }                               \r
 515 \r
 516                         /* Remember the top priority to make context switching faster.  Use\r
 517                         the priority in pxNewTCB as this has been capped to a valid value. */\r
 518                         if( pxNewTCB->uxPriority > uxTopUsedPriority )\r
 519                         {\r
 520                                 uxTopUsedPriority = pxNewTCB->uxPriority;\r
 521                         }\r
 522 \r
 523                         /* Add a counter into the TCB for tracing only. */\r
 524                         pxNewTCB->uxTCBNumber = uxTaskNumber;\r
 525                         uxTaskNumber++;\r
 526 \r
 527                         prvAddTaskToReadyQueue( pxNewTCB );\r
 528 \r
 529                         xReturn = pdPASS;\r
 530                 }\r
 531                 portEXIT_CRITICAL();\r
 532         }\r
 533         else\r
 534         {\r
 535                 xReturn = errCOULD_NOT_ALLOCATE_REQUIRED_MEMORY;\r
 536         }\r
 537 \r
 538         if( xReturn == pdPASS )\r
 539         {\r
 540                 if( ( void * ) pxCreatedTask != NULL )\r
 541                 {\r
 542                         /* Pass the TCB out - in an anonymous way.  The calling function/\r
 543                         task can use this as a handle to delete the task later if\r
 544                         required.*/\r
 545                         *pxCreatedTask = ( xTaskHandle ) pxNewTCB;\r
 546                 }\r
 547 \r
 548                 if( xSchedulerRunning != pdFALSE )\r
 549                 {\r
 550                         /* If the created task is of a higher priority than the current task\r
 551                         then it should run now. */\r
 552                         if( pxCurrentTCB->uxPriority < uxPriority )\r
 553                         {\r
 554                                 taskYIELD();\r
 555                         }\r
 556                 }\r
 557         }\r
 558 \r
 559         return xReturn;\r
 560 }\r
 561 /*-----------------------------------------------------------*/\r
 562 \r
 563 #if ( INCLUDE_vTaskDelete == 1 )\r
 564 \r
 565         void vTaskDelete( xTaskHandle pxTaskToDelete )\r
 566         {\r
 567         tskTCB *pxTCB;\r
 568 \r
 569                 taskENTER_CRITICAL();\r
 570                 {\r
 571                         /* If null is passed in here then we are deleting ourselves. */\r
 572                         pxTCB = prvGetTCBFromHandle( pxTaskToDelete );\r
 573 \r
 574                         /* Remove task from the ready list and place in the     termination list.\r
 575                         This will stop the task from be scheduled.  The idle task will check\r
 576                         the termination list and free up any memory allocated by the\r
 577                         scheduler for the TCB and stack. */\r
 578                         vListRemove( &( pxTCB->xGenericListItem ) );\r
 579 \r
 580                         /* Is the task waiting on an event also? */                                                                                             \r
 581                         if( pxTCB->xEventListItem.pvContainer )\r
 582                         {\r
 583                                 vListRemove( &( pxTCB->xEventListItem ) );\r
 584                         }\r
 585 \r
 586                         vListInsertEnd( ( xList * ) &xTasksWaitingTermination, &( pxTCB->xGenericListItem ) );\r
 587 \r
 588                         /* Increment the ucTasksDeleted variable so the idle task knows\r
 589                         there is a task that has been deleted and that it should therefore\r
 590                         check the xTasksWaitingTermination list. */\r
 591                         ++uxTasksDeleted;\r
 592                 }\r
 593                 taskEXIT_CRITICAL();\r
 594 \r
 595                 /* Force a reschedule if we have just deleted the current task. */\r
 596                 if( ( void * ) pxTaskToDelete == NULL )\r
 597                 {\r
 598                         taskYIELD();\r
 599                 }\r
 600         }\r
 601 \r
 602 #endif\r
 603 \r
 604 \r
 605 \r
 606 \r
 607 \r
 608 \r
 609 /*-----------------------------------------------------------\r
 610  * TASK CONTROL API documented in task.h\r
 611  *----------------------------------------------------------*/\r
 612 \r
 613 #if ( INCLUDE_vTaskDelayUntil == 1 )\r
 614 \r
 615         void vTaskDelayUntil( portTickType *pxPreviousWakeTime, portTickType xTimeIncrement )\r
 616         {\r
 617         portTickType xTimeToWake;\r
 618         portBASE_TYPE xAlreadyYielded, xShouldDelay = pdFALSE;\r
 619 \r
 620                 vTaskSuspendAll();\r
 621                 {\r
 622                         /* Generate the tick time at which the task wants to wake. */\r
 623                         xTimeToWake = *pxPreviousWakeTime + xTimeIncrement;\r
 624 \r
 625                         if( xTickCount < *pxPreviousWakeTime )\r
 626                         {\r
 627                                 /* The tick count has overflowed since this function was\r
 628                                 lasted called.  In this case the only time we should ever\r
 629                                 actually delay is if the wake time has also     overflowed,\r
 630                                 and the wake time is greater than the tick time.  When this\r
 631                                 is the case it is as if neither time had overflowed. */\r
 632                                 if( ( xTimeToWake < *pxPreviousWakeTime ) && ( xTimeToWake > xTickCount ) )\r
 633                                 {\r
 634                                         xShouldDelay = pdTRUE;\r
 635                                 }\r
 636                         }\r
 637                         else\r
 638                         {\r
 639                                 /* The tick time has not overflowed.  In this case we will\r
 640                                 delay if either the wake time has overflowed, and/or the\r
 641                                 tick time is less than the wake time. */\r
 642                                 if( ( xTimeToWake < *pxPreviousWakeTime ) || ( xTimeToWake > xTickCount ) )\r
 643                                 {\r
 644                                         xShouldDelay = pdTRUE;\r
 645                                 }\r
 646                         }\r
 647 \r
 648                         /* Update the wake time ready for the next call. */\r
 649                         *pxPreviousWakeTime = xTimeToWake;\r
 650 \r
 651                         if( xShouldDelay )\r
 652                         {\r
 653                                 /* We must remove ourselves from the ready list before adding\r
 654                                 ourselves to the blocked list as the same list item is used for\r
 655                                 both lists. */\r
 656                                 vListRemove( ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );\r
 657 \r
 658                                 /* The list item will be inserted in wake time order. */\r
 659                                 listSET_LIST_ITEM_VALUE( &( pxCurrentTCB->xGenericListItem ), xTimeToWake );\r
 660 \r
 661                                 if( xTimeToWake < xTickCount )\r
 662                                 {\r
 663                                         /* Wake time has overflowed.  Place this item in the\r
 664                                         overflow list. */\r
 665                                         vListInsert( ( xList * ) pxOverflowDelayedTaskList, ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );\r
 666                                 }\r
 667                                 else\r
 668                                 {\r
 669                                         /* The wake time has not overflowed, so we can use the\r
 670                                         current block list. */\r
 671                                         vListInsert( ( xList * ) pxDelayedTaskList, ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );\r
 672                                 }\r
 673                         }\r
 674                 }\r
 675                 xAlreadyYielded = xTaskResumeAll();\r
 676 \r
 677                 /* Force a reschedule if xTaskResumeAll has not already done so, we may\r
 678                 have put ourselves to sleep. */\r
 679                 if( !xAlreadyYielded )\r
 680                 {\r
 681                         taskYIELD();\r
 682                 }\r
 683         }       \r
 684         \r
 685 #endif\r
 686 /*-----------------------------------------------------------*/\r
 687 \r
 688 #if ( INCLUDE_vTaskDelay == 1 )\r
 689 \r
 690         void vTaskDelay( portTickType xTicksToDelay )\r
 691         {\r
 692         portTickType xTimeToWake;\r
 693         signed portBASE_TYPE xAlreadyYielded = pdFALSE;\r
 694 \r
 695                 /* A delay time of zero just forces a reschedule. */\r
 696                 if( xTicksToDelay > ( portTickType ) 0 )\r
 697                 {\r
 698                         vTaskSuspendAll();\r
 699                         {\r
 700                                 /* A task that is removed from the event list while the\r
 701                                 scheduler is suspended will not get placed in the ready\r
 702                                 list or removed from the blocked list until the scheduler\r
 703                                 is resumed.\r
 704                                 \r
 705                                 This task cannot be in an event list as it is the currently\r
 706                                 executing task. */\r
 707 \r
 708                                 /* Calculate the time to wake - this may overflow but this is\r
 709                                 not a problem. */\r
 710                                 xTimeToWake = xTickCount + xTicksToDelay;\r
 711 \r
 712                                 /* We must remove ourselves from the ready list before adding\r
 713                                 ourselves to the blocked list as the same list item is used for\r
 714                                 both lists. */\r
 715                                 vListRemove( ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );\r
 716 \r
 717                                 /* The list item will be inserted in wake time order. */\r
 718                                 listSET_LIST_ITEM_VALUE( &( pxCurrentTCB->xGenericListItem ), xTimeToWake );\r
 719 \r
 720                                 if( xTimeToWake < xTickCount )\r
 721                                 {\r
 722                                         /* Wake time has overflowed.  Place this item in the\r
 723                                         overflow list. */\r
 724                                         vListInsert( ( xList * ) pxOverflowDelayedTaskList, ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );\r
 725                                 }\r
 726                                 else\r
 727                                 {\r
 728                                         /* The wake time has not overflowed, so we can use the\r
 729                                         current block list. */\r
 730                                         vListInsert( ( xList * ) pxDelayedTaskList, ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );\r
 731                                 }\r
 732                         }\r
 733                         xAlreadyYielded = xTaskResumeAll();\r
 734                 }\r
 735                 \r
 736                 /* Force a reschedule if xTaskResumeAll has not already done so, we may\r
 737                 have put ourselves to sleep. */\r
 738                 if( !xAlreadyYielded )\r
 739                 {\r
 740                         taskYIELD();\r
 741                 }\r
 742         }\r
 743         \r
 744 #endif\r
 745 /*-----------------------------------------------------------*/\r
 746 \r
 747 #if ( INCLUDE_uxTaskPriorityGet == 1 )\r
 748 \r
 749         unsigned portBASE_TYPE uxTaskPriorityGet( xTaskHandle pxTask )\r
 750         {\r
 751         tskTCB *pxTCB;\r
 752         unsigned portBASE_TYPE uxReturn;\r
 753 \r
 754                 taskENTER_CRITICAL();\r
 755                 {\r
 756                         /* If null is passed in here then we are changing the\r
 757                         priority of the calling function. */\r
 758                         pxTCB = prvGetTCBFromHandle( pxTask );\r
 759                         uxReturn = pxTCB->uxPriority;\r
 760                 }\r
 761                 taskEXIT_CRITICAL();\r
 762 \r
 763                 return uxReturn;\r
 764         }\r
 765 \r
 766 #endif\r
 767 /*-----------------------------------------------------------*/\r
 768 \r
 769 #if ( INCLUDE_vTaskPrioritySet == 1 )\r
 770 \r
 771         void vTaskPrioritySet( xTaskHandle pxTask, unsigned portBASE_TYPE uxNewPriority )\r
 772         {\r
 773         tskTCB *pxTCB;\r
 774         unsigned portBASE_TYPE uxCurrentPriority;\r
 775 \r
 776                 /* Ensure the new priority is valid. */\r
 777                 if( uxNewPriority >= configMAX_PRIORITIES )\r
 778                 {\r
 779                         uxNewPriority = configMAX_PRIORITIES - 1;\r
 780                 }\r
 781 \r
 782                 taskENTER_CRITICAL();\r
 783                 {\r
 784                         /* If null is passed in here then we are changing the\r
 785                         priority of the calling function. */\r
 786                         pxTCB = prvGetTCBFromHandle( pxTask );\r
 787                         uxCurrentPriority = pxTCB->uxPriority;\r
 788 \r
 789                         if( uxCurrentPriority != uxNewPriority )\r
 790                         {\r
 791                                 pxTCB->uxPriority = uxNewPriority;\r
 792 \r
 793                                 /* If the task is in the blocked or suspended list we need do\r
 794                                 nothing more than change it's priority variable. However, if\r
 795                                 the task is in a ready list it needs to be removed and placed\r
 796                                 in the queue appropriate to its new priority. */\r
 797                                 if( listIS_CONTAINED_WITHIN( &( pxReadyTasksLists[ uxCurrentPriority ] ), &( pxTCB->xGenericListItem ) ) )\r
 798                                 {\r
 799                                         if( uxSchedulerSuspended == ( unsigned portBASE_TYPE ) pdFALSE )\r
 800                                         {\r
 801                                                 /* The task is currently in its ready list - remove before adding\r
 802                                                 it to it's new ready list. */\r
 803                                                 vListRemove( &( pxTCB->xGenericListItem ) );\r
 804                                                 prvAddTaskToReadyQueue( pxTCB );\r
 805                                         }\r
 806                                         else\r
 807                                         {\r
 808                                                 /* We cannot access the delayed or ready lists, so will hold this\r
 809                                                 task pending until the scheduler is resumed. */\r
 810                                                 vListInsertEnd( ( xList * ) &( xPendingReadyList ), &( pxTCB->xEventListItem ) );\r
 811                                         }\r
 812                                 }                       \r
 813                         }\r
 814                 }\r
 815                 taskEXIT_CRITICAL();\r
 816 \r
 817                 /* The priority change may have readied a task of higher\r
 818                 priority than the calling task. */\r
 819                 taskYIELD();\r
 820         }\r
 821 \r
 822 #endif\r
 823 /*-----------------------------------------------------------*/\r
 824 \r
 825 #if ( INCLUDE_vTaskSuspend == 1 )\r
 826 \r
 827         void vTaskSuspend( xTaskHandle pxTaskToSuspend )\r
 828         {\r
 829         tskTCB *pxTCB;\r
 830 \r
 831                 taskENTER_CRITICAL();\r
 832                 {\r
 833                         /* If null is passed in here then we are suspending ourselves. */\r
 834                         pxTCB = prvGetTCBFromHandle( pxTaskToSuspend );\r
 835 \r
 836                         /* Remove task from the ready/delayed list and place in the     suspended list. */\r
 837                         vListRemove( &( pxTCB->xGenericListItem ) );\r
 838 \r
 839                         /* Is the task waiting on an event also? */                                                                                             \r
 840                         if( pxTCB->xEventListItem.pvContainer )\r
 841                         {\r
 842                                 vListRemove( &( pxTCB->xEventListItem ) );\r
 843                         }\r
 844 \r
 845                         vListInsertEnd( ( xList * ) &xSuspendedTaskList, &( pxTCB->xGenericListItem ) );\r
 846                 }\r
 847                 taskEXIT_CRITICAL();\r
 848 \r
 849                 /* We may have just suspended the current task. */\r
 850                 if( ( void * ) pxTaskToSuspend == NULL )\r
 851                 {\r
 852                         taskYIELD();\r
 853                 }\r
 854         }\r
 855 \r
 856 #endif\r
 857 /*-----------------------------------------------------------*/\r
 858 \r
 859 #if ( INCLUDE_vTaskSuspend == 1 )\r
 860 \r
 861         void vTaskResume( xTaskHandle pxTaskToResume )\r
 862         {\r
 863         tskTCB *pxTCB;\r
 864         portBASE_TYPE xYieldRequired;\r
 865 \r
 866                 /* Remove the task from whichever list it is currently in, and place\r
 867                 it in the ready list. */\r
 868                 pxTCB = ( tskTCB * ) pxTaskToResume;\r
 869 \r
 870                 /* The parameter cannot be NULL as it is impossible to resume the\r
 871                 currently executing task. */\r
 872                 if( pxTCB != NULL )\r
 873                 {\r
 874                         taskENTER_CRITICAL();\r
 875                         {\r
 876                                 if( uxSchedulerSuspended == ( unsigned portBASE_TYPE ) pdFALSE )\r
 877                                 {\r
 878                                         xYieldRequired = ( pxTCB->uxPriority >= pxCurrentTCB->uxPriority );\r
 879                                         vListRemove(  &( pxTCB->xGenericListItem ) );\r
 880                                         prvAddTaskToReadyQueue( pxTCB );\r
 881                                 }\r
 882                                 else\r
 883                                 {\r
 884                                         /* We cannot access the delayed or ready lists, so will hold this\r
 885                                         task pending until the scheduler is resumed. */\r
 886                                         xYieldRequired = pdFALSE;\r
 887                                         vListInsertEnd( ( xList * ) &( xPendingReadyList ), &( pxTCB->xEventListItem ) );\r
 888                                 }\r
 889                         }\r
 890                         taskEXIT_CRITICAL();\r
 891 \r
 892                         /* We may have just resumed a higher priority task. */\r
 893                         if( xYieldRequired )\r
 894                         {\r
 895                                 /* This yield may not cause the task just resumed to run, but\r
 896                                 will leave the lists in the correct state for the next yield. */\r
 897                                 taskYIELD();\r
 898                         }\r
 899                 }\r
 900         }\r
 901 \r
 902 #endif\r
 903 \r
 904 \r
 905 \r
 906 \r
 907 \r
 908 /*-----------------------------------------------------------\r
 909  * PUBLIC SCHEDULER CONTROL documented in task.h\r
 910  *----------------------------------------------------------*/\r
 911 \r
 912 \r
 913 void vTaskStartScheduler( void )\r
 914 {\r
 915 portBASE_TYPE xReturn;\r
 916 \r
 917         /* Add the idle task at the lowest priority. */\r
 918         xReturn = xTaskCreate( prvIdleTask, ( signed portCHAR * ) "IDLE", tskIDLE_STACK_SIZE, ( void * ) NULL, tskIDLE_PRIORITY, ( xTaskHandle * ) NULL );\r
 919 \r
 920         if( xReturn == pdPASS )\r
 921         {\r
 922                 /* Interrupts are turned off here, to ensure a tick does not occur\r
 923                 before or during the call to xPortStartScheduler().  The stacks of\r
 924                 the created tasks contain a status word with interrupts switched on\r
 925                 so interrupts will automatically get re-enabled when the first task\r
 926                 starts to run.\r
 927                 \r
 928                 STEPPING THROUGH HERE USING A DEBUGGER CAN CAUSE BIG PROBLEMS IF THE\r
 929                 DEBUGGER ALLOWS INTERRUPTS TO BE PROCESSED. */\r
 930                 portDISABLE_INTERRUPTS();\r
 931 \r
 932                 xSchedulerRunning = pdTRUE;\r
 933                 xTickCount = ( portTickType ) 0;\r
 934 \r
 935                 /* Setting up the timer tick is hardware specific and thus in the\r
 936                 portable interface. */\r
 937                 if( xPortStartScheduler() )\r
 938                 {\r
 939                         /* Should not reach here as if the scheduler is running the\r
 940                         function will not return. */\r
 941                 }\r
 942                 else\r
 943                 {\r
 944                         /* Should only reach here if a task calls xTaskEndScheduler(). */\r
 945                 }\r
 946         }\r
 947 }\r
 948 /*-----------------------------------------------------------*/\r
 949 \r
 950 void vTaskEndScheduler( void )\r
 951 {\r
 952         /* Stop the scheduler interrupts and call the portable scheduler end\r
 953         routine so the original ISRs can be restored if necessary.  The port\r
 954         layer must ensure interrupts enable     bit is left in the correct state. */\r
 955         portDISABLE_INTERRUPTS();\r
 956         xSchedulerRunning = pdFALSE;\r
 957         vPortEndScheduler();\r
 958 }\r
 959 /*----------------------------------------------------------*/\r
 960 \r
 961 void vTaskSuspendAll( void )\r
 962 {\r
 963         portENTER_CRITICAL();\r
 964                 ++uxSchedulerSuspended;\r
 965         portEXIT_CRITICAL();\r
 966 }\r
 967 /*----------------------------------------------------------*/\r
 968 \r
 969 signed portBASE_TYPE xTaskResumeAll( void )\r
 970 {\r
 971 register tskTCB *pxTCB;\r
 972 signed portBASE_TYPE xAlreadyYielded = pdFALSE;\r
 973 \r
 974         /* It is possible that an ISR caused a task to be removed from an event\r
 975         list while the scheduler was suspended.  If this was the case then the\r
 976         removed task will have been added to the xPendingReadyList.  Once the\r
 977         scheduler has been resumed it is safe to move all the pending ready\r
 978         tasks from this list into their appropriate ready list. */\r
 979         portENTER_CRITICAL();\r
 980         {\r
 981                 --uxSchedulerSuspended;\r
 982 \r
 983                 if( uxSchedulerSuspended == ( unsigned portBASE_TYPE ) pdFALSE )\r
 984                 {                       \r
 985                         if( uxCurrentNumberOfTasks > ( unsigned portBASE_TYPE ) 0 )\r
 986                         {\r
 987                                 portBASE_TYPE xYieldRequired = pdFALSE;\r
 988                                 \r
 989                                 /* Move any readied tasks from the pending list into the\r
 990                                 appropriate ready list. */\r
 991                                 while( ( pxTCB = ( tskTCB * ) listGET_OWNER_OF_HEAD_ENTRY(  ( ( xList * ) &xPendingReadyList ) ) ) != NULL )\r
 992                                 {\r
 993                                         vListRemove( &( pxTCB->xEventListItem ) );\r
 994                                         vListRemove( &( pxTCB->xGenericListItem ) );\r
 995                                         prvAddTaskToReadyQueue( pxTCB );\r
 996                                         \r
 997                                         /* If we have moved a task that has a priority higher than\r
 998                                         the current task then we should yield. */\r
 999                                         if( pxTCB->uxPriority >= pxCurrentTCB->uxPriority )\r
1000                                         {\r
1001                                                 xYieldRequired = pdTRUE;\r
1002                                         }\r
1003                                 }\r
1004 \r
1005                                 /* If any ticks occurred while the scheduler was suspended then\r
1006                                 they should be processed now.  This ensures the tick count does not\r
1007                                 slip, and that any delayed tasks are resumed at the correct time. */\r
1008                                 if( uxMissedTicks > ( unsigned portBASE_TYPE ) 0 )\r
1009                                 {\r
1010                                         while( uxMissedTicks > ( unsigned portBASE_TYPE ) 0 )\r
1011                                         {\r
1012                                                 vTaskIncrementTick();\r
1013                                                 --uxMissedTicks;\r
1014                                         }\r
1015 \r
1016                                         /* As we have processed some ticks it is appropriate to yield\r
1017                                         to ensure the highest priority task that is ready to run is\r
1018                                         the task actually running. */\r
1019                                         xYieldRequired = pdTRUE;\r
1020                                 }\r
1021                                 \r
1022                                 if( ( xYieldRequired == pdTRUE ) || ( xMissedYield == pdTRUE ) )\r
1023                                 {\r
1024                                         xAlreadyYielded = pdTRUE;\r
1025                                         xMissedYield = pdFALSE;\r
1026                                         taskYIELD();\r
1027                                 }\r
1028                         }\r
1029                 }\r
1030         }\r
1031         portEXIT_CRITICAL();\r
1032 \r
1033         return xAlreadyYielded;\r
1034 }\r
1035 \r
1036 \r
1037 \r
1038 \r
1039 \r
1040 \r
1041 /*-----------------------------------------------------------\r
1042  * PUBLIC TASK UTILITIES documented in task.h\r
1043  *----------------------------------------------------------*/\r
1044 \r
1045 \r
1046 \r
1047 portTickType xTaskGetTickCount( void )\r
1048 {\r
1049 portTickType xTicks;\r
1050 \r
1051         /* Critical section required if running on a 16 bit processor. */\r
1052         taskENTER_CRITICAL();\r
1053         {\r
1054                 xTicks = xTickCount;\r
1055         }\r
1056         taskEXIT_CRITICAL();\r
1057 \r
1058         return xTicks;\r
1059 }\r
1060 /*-----------------------------------------------------------*/\r
1061 \r
1062 unsigned portBASE_TYPE uxTaskGetNumberOfTasks( void )\r
1063 {\r
1064 unsigned portBASE_TYPE uxNumberOfTasks;\r
1065 \r
1066         taskENTER_CRITICAL();\r
1067                 uxNumberOfTasks = uxCurrentNumberOfTasks;\r
1068         taskEXIT_CRITICAL();\r
1069 \r
1070         return uxNumberOfTasks;\r
1071 }\r
1072 /*-----------------------------------------------------------*/\r
1073 \r
1074 #if ( ( configUSE_TRACE_FACILITY == 1 ) && ( INCLUDE_vTaskDelete == 1 ) && ( INCLUDE_vTaskSuspend == 1 ) )\r
1075 \r
1076         void vTaskList( signed portCHAR *pcWriteBuffer )\r
1077         {\r
1078         unsigned portBASE_TYPE uxQueue;\r
1079 \r
1080                 /* This is a VERY costly function that should be used for debug only.\r
1081                 It leaves interrupts disabled for a LONG time. */\r
1082 \r
1083                 taskENTER_CRITICAL();\r
1084                 {\r
1085                         /* Run through all the lists that could potentially contain a TCB and\r
1086                         report the task name, state and stack high water mark. */\r
1087 \r
1088                         pcWriteBuffer[ 0 ] = ( signed portCHAR ) 0x00;\r
1089                         strcat( ( portCHAR * ) pcWriteBuffer, ( const portCHAR * ) "\r\n" );\r
1090 \r
1091                         uxQueue = uxTopUsedPriority + 1;\r
1092 \r
1093                         do\r
1094                         {\r
1095                                 uxQueue--;\r
1096 \r
1097                                 if( !listLIST_IS_EMPTY( &( pxReadyTasksLists[ uxQueue ] ) ) )\r
1098                                 {\r
1099                                         prvListTaskWithinSingleList( pcWriteBuffer, ( xList * ) &( pxReadyTasksLists[ uxQueue ] ), tskREADY_CHAR );                     \r
1100                                 }\r
1101                         }while( uxQueue > ( unsigned portSHORT ) tskIDLE_PRIORITY );\r
1102 \r
1103                         if( !listLIST_IS_EMPTY( pxDelayedTaskList ) )\r
1104                         {\r
1105                                 prvListTaskWithinSingleList( pcWriteBuffer, ( xList * ) pxDelayedTaskList, tskBLOCKED_CHAR );\r
1106                         }\r
1107 \r
1108                         if( !listLIST_IS_EMPTY( pxOverflowDelayedTaskList ) )\r
1109                         {\r
1110                                 prvListTaskWithinSingleList( pcWriteBuffer, ( xList * ) pxOverflowDelayedTaskList, tskBLOCKED_CHAR );\r
1111                         }\r
1112 \r
1113                         if( !listLIST_IS_EMPTY( &xTasksWaitingTermination ) )\r
1114                         {\r
1115                                 prvListTaskWithinSingleList( pcWriteBuffer, ( xList * ) &xTasksWaitingTermination, tskDELETED_CHAR );\r
1116                         }\r
1117 \r
1118                         if( !listLIST_IS_EMPTY( &xSuspendedTaskList ) )\r
1119                         {\r
1120                                 prvListTaskWithinSingleList( pcWriteBuffer, ( xList * ) &xSuspendedTaskList, tskSUSPENDED_CHAR );\r
1121                         }\r
1122                 }\r
1123                 taskEXIT_CRITICAL();\r
1124         }\r
1125 \r
1126 #endif\r
1127 /*----------------------------------------------------------*/\r
1128 \r
1129 #if ( configUSE_TRACE_FACILITY == 1 )\r
1130 \r
1131         void vTaskStartTrace( signed portCHAR * pcBuffer, unsigned portLONG ulBufferSize )\r
1132         {\r
1133                 portENTER_CRITICAL();\r
1134                 {\r
1135                         pcTraceBuffer = ( volatile signed portCHAR * volatile )pcBuffer;\r
1136                         pcTraceBufferStart = pcBuffer;\r
1137                         pcTraceBufferEnd = pcBuffer + ( ulBufferSize - tskSIZE_OF_EACH_TRACE_LINE );\r
1138                         xTracing = pdTRUE;\r
1139                 }\r
1140                 portEXIT_CRITICAL();\r
1141         }\r
1142 \r
1143 #endif\r
1144 /*----------------------------------------------------------*/\r
1145 \r
1146 #if ( configUSE_TRACE_FACILITY == 1 )\r
1147 \r
1148         unsigned portLONG ulTaskEndTrace( void )\r
1149         {\r
1150         unsigned portLONG ulBufferLength;\r
1151 \r
1152                 portENTER_CRITICAL();\r
1153                         xTracing = pdFALSE;\r
1154                 portEXIT_CRITICAL();\r
1155 \r
1156                 ulBufferLength = ( unsigned portLONG ) ( pcTraceBuffer - pcTraceBufferStart );\r
1157 \r
1158                 return ulBufferLength;\r
1159         }\r
1160 \r
1161 #endif\r
1162 \r
1163 \r
1164 \r
1165 /*-----------------------------------------------------------\r
1166  * SCHEDULER INTERNALS AVAILABLE FOR PORTING PURPOSES\r
1167  * documented in task.h\r
1168  *----------------------------------------------------------*/\r
1169 \r
1170 \r
1171 inline void vTaskIncrementTick( void )\r
1172 {\r
1173         /* Called by the portable layer each time a tick interrupt occurs.\r
1174         Increments the tick then checks to see if the new tick value will cause any\r
1175         tasks to be unblocked. */\r
1176         if( uxSchedulerSuspended == ( unsigned portBASE_TYPE ) pdFALSE )\r
1177         {\r
1178                 ++xTickCount;\r
1179                 if( xTickCount == ( portTickType ) 0 )\r
1180                 {\r
1181                         xList *pxTemp;\r
1182 \r
1183                         /* Tick count has overflowed so we need to swap the delay lists.  If there are\r
1184                         any items in pxDelayedTaskList here then there is an error! */\r
1185                         pxTemp = pxDelayedTaskList;\r
1186                         pxDelayedTaskList = pxOverflowDelayedTaskList;\r
1187                         pxOverflowDelayedTaskList = pxTemp;\r
1188                 }\r
1189 \r
1190                 /* See if this tick has made a timeout expire. */\r
1191                 prvCheckDelayedTasks();\r
1192         }\r
1193         else\r
1194         {\r
1195                 ++uxMissedTicks;\r
1196         }\r
1197 \r
1198         #if ( configUSE_TICK_HOOK == 1 )\r
1199         {\r
1200                 extern void vApplicationTickHook( void );\r
1201 \r
1202                 vApplicationTickHook();\r
1203         }\r
1204         #endif\r
1205 }\r
1206 /*-----------------------------------------------------------*/\r
1207 \r
1208 #if ( ( INCLUDE_vTaskCleanUpResources == 1 ) && ( INCLUDE_vTaskSuspend == 1 ) )\r
1209 \r
1210         void vTaskCleanUpResources( void )\r
1211         {\r
1212         unsigned portSHORT usQueue;\r
1213         volatile tskTCB *pxTCB;\r
1214 \r
1215                 usQueue = ( unsigned portSHORT ) uxTopUsedPriority + ( unsigned portSHORT ) 1;\r
1216 \r
1217                 /* Remove any TCB's from the ready queues. */\r
1218                 do\r
1219                 {\r
1220                         usQueue--;\r
1221 \r
1222                         while( !listLIST_IS_EMPTY( &( pxReadyTasksLists[ usQueue ] ) ) )\r
1223                         {\r
1224                                 listGET_OWNER_OF_NEXT_ENTRY( pxTCB, &( pxReadyTasksLists[ usQueue ] ) );\r
1225                                 vListRemove( ( xListItem * ) &( pxTCB->xGenericListItem ) );\r
1226 \r
1227                                 prvDeleteTCB( ( tskTCB * ) pxTCB );\r
1228                         }\r
1229                 }while( usQueue > ( unsigned portSHORT ) tskIDLE_PRIORITY );\r
1230 \r
1231                 /* Remove any TCB's from the delayed queue. */\r
1232                 while( !listLIST_IS_EMPTY( &xDelayedTaskList1 ) )\r
1233                 {\r
1234                         listGET_OWNER_OF_NEXT_ENTRY( pxTCB, &xDelayedTaskList1 );\r
1235                         vListRemove( ( xListItem * ) &( pxTCB->xGenericListItem ) );\r
1236 \r
1237                         prvDeleteTCB( ( tskTCB * ) pxTCB );\r
1238                 }\r
1239 \r
1240                 /* Remove any TCB's from the overflow delayed queue. */\r
1241                 while( !listLIST_IS_EMPTY( &xDelayedTaskList2 ) )\r
1242                 {\r
1243                         listGET_OWNER_OF_NEXT_ENTRY( pxTCB, &xDelayedTaskList2 );\r
1244                         vListRemove( ( xListItem * ) &( pxTCB->xGenericListItem ) );\r
1245 \r
1246                         prvDeleteTCB( ( tskTCB * ) pxTCB );\r
1247                 }\r
1248 \r
1249                 while( !listLIST_IS_EMPTY( &xSuspendedTaskList ) )\r
1250                 {\r
1251                         listGET_OWNER_OF_NEXT_ENTRY( pxTCB, &xSuspendedTaskList );\r
1252                         vListRemove( ( xListItem * ) &( pxTCB->xGenericListItem ) );\r
1253 \r
1254                         prvDeleteTCB( ( tskTCB * ) pxTCB );\r
1255                 }               \r
1256 \r
1257                 while( !listLIST_IS_EMPTY( &xPendingReadyList ) )\r
1258                 {\r
1259                         listGET_OWNER_OF_NEXT_ENTRY( pxTCB, &xPendingReadyList );\r
1260                         vListRemove( ( xListItem * ) &( pxTCB->xGenericListItem ) );\r
1261 \r
1262                         prvDeleteTCB( ( tskTCB * ) pxTCB );\r
1263                 }               \r
1264         }\r
1265 \r
1266 #endif\r
1267 /*-----------------------------------------------------------*/\r
1268 \r
1269 void vTaskSwitchContext( void )\r
1270 {\r
1271         if( uxSchedulerSuspended != ( unsigned portBASE_TYPE ) pdFALSE )\r
1272         {\r
1273                 /* The scheduler is currently suspended - do not allow a context\r
1274                 switch. */\r
1275                 xMissedYield = pdTRUE;\r
1276                 return;\r
1277         }\r
1278 \r
1279         /* Find the highest priority queue that contains ready tasks. */\r
1280         while( listLIST_IS_EMPTY( &( pxReadyTasksLists[ uxTopReadyPriority ] ) ) )\r
1281         {\r
1282                 --uxTopReadyPriority;\r
1283         }\r
1284 \r
1285         /* listGET_OWNER_OF_NEXT_ENTRY walks through the list, so the tasks of the\r
1286         same priority get an equal share of the processor time. */\r
1287         listGET_OWNER_OF_NEXT_ENTRY( pxCurrentTCB, &( pxReadyTasksLists[ uxTopReadyPriority ] ) );\r
1288         vWriteTraceToBuffer();\r
1289 }\r
1290 /*-----------------------------------------------------------*/\r
1291 \r
1292 void vTaskPlaceOnEventList( xList *pxEventList, portTickType xTicksToWait )\r
1293 {\r
1294 portTickType xTimeToWake;\r
1295 \r
1296         /* THIS FUNCTION MUST BE CALLED WITH INTERRUPTS DISABLED OR THE\r
1297         SCHEDULER SUSPENDED. */\r
1298 \r
1299         /* Place the event list item of the TCB in the appropriate event list.\r
1300         This is placed in the list in priority order so the highest priority task\r
1301         is the first to be woken by the event. */\r
1302         vListInsert( ( xList * ) pxEventList, ( xListItem * ) &( pxCurrentTCB->xEventListItem ) );\r
1303 \r
1304         /* Calculate the time at which the task should be woken if the event does\r
1305         not occur.  This may overflow but this doesn't matter. */\r
1306         xTimeToWake = xTickCount + xTicksToWait;\r
1307 \r
1308         /* We must remove ourselves from the ready list before adding ourselves\r
1309         to the blocked list as the same list item is used for both lists.  We have\r
1310         exclusive access to the ready lists as the scheduler is locked. */\r
1311         vListRemove( ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );\r
1312 \r
1313         listSET_LIST_ITEM_VALUE( &( pxCurrentTCB->xGenericListItem ), xTimeToWake );\r
1314 \r
1315         if( xTimeToWake < xTickCount )\r
1316         {\r
1317                 /* Wake time has overflowed.  Place this item in the overflow list. */\r
1318                 vListInsert( ( xList * ) pxOverflowDelayedTaskList, ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );\r
1319         }\r
1320         else\r
1321         {\r
1322                 /* The wake time has not overflowed, so we can use the current block list. */\r
1323                 vListInsert( ( xList * ) pxDelayedTaskList, ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );\r
1324         }\r
1325 }\r
1326 /*-----------------------------------------------------------*/\r
1327 \r
1328 signed portBASE_TYPE xTaskRemoveFromEventList( const xList *pxEventList )\r
1329 {\r
1330 tskTCB *pxUnblockedTCB;\r
1331 portBASE_TYPE xReturn;\r
1332 \r
1333         /* THIS FUNCTION MUST BE CALLED WITH INTERRUPTS DISABLED OR THE\r
1334         SCHEDULER SUSPENDED.  It can also be called from within an ISR. */\r
1335 \r
1336         /* The event list is sorted in priority order, so we can remove the\r
1337         first in the list, remove the TCB from the delayed list, and add\r
1338         it to the ready list.\r
1339         \r
1340         If an event is for a queue that is locked then this function will never\r
1341         get called - the lock count on the queue will get modified instead.  This\r
1342         means we can always expect exclusive access to the event list here. */\r
1343         pxUnblockedTCB = ( tskTCB * ) listGET_OWNER_OF_HEAD_ENTRY( pxEventList );\r
1344         vListRemove( &( pxUnblockedTCB->xEventListItem ) );\r
1345 \r
1346         if( uxSchedulerSuspended == ( unsigned portBASE_TYPE ) pdFALSE )\r
1347         {\r
1348                 vListRemove( &( pxUnblockedTCB->xGenericListItem ) );\r
1349                 prvAddTaskToReadyQueue( pxUnblockedTCB );\r
1350         }\r
1351         else\r
1352         {\r
1353                 /* We cannot access the delayed or ready lists, so will hold this\r
1354                 task pending until the scheduler is resumed. */\r
1355                 vListInsertEnd( ( xList * ) &( xPendingReadyList ), &( pxUnblockedTCB->xEventListItem ) );\r
1356         }\r
1357 \r
1358         if( pxUnblockedTCB->uxPriority >= pxCurrentTCB->uxPriority )\r
1359         {\r
1360                 /* Return true if the task removed from the event list has\r
1361                 a higher priority than the calling task.  This allows\r
1362                 the calling task to know if it should force a context\r
1363                 switch now. */\r
1364                 xReturn = pdTRUE;\r
1365         }\r
1366         else\r
1367         {\r
1368                 xReturn = pdFALSE;\r
1369         }\r
1370 \r
1371         return xReturn;\r
1372 }\r
1373 \r
1374 \r
1375 \r
1376 \r
1377 \r
1378 /*\r
1379  * -----------------------------------------------------------\r
1380  * The Idle task.\r
1381  * ----------------------------------------------------------\r
1382  *\r
1383  * The portTASK_FUNCTION() macro is used to allow port/compiler specific\r
1384  * language extensions.  The equivalent prototype for this function is:\r
1385  *\r
1386  * void prvIdleTask( void *pvParameters );\r
1387  *\r
1388  */\r
1389 static portTASK_FUNCTION( prvIdleTask, pvParameters )\r
1390 {\r
1391         /* Stop warnings. */\r
1392         ( void ) pvParameters;\r
1393 \r
1394         for( ;; )\r
1395         {\r
1396                 /* See if any tasks have been deleted. */\r
1397                 prvCheckTasksWaitingTermination();\r
1398 \r
1399                 #if ( configUSE_PREEMPTION == 0 )\r
1400                 {\r
1401                         /* If we are not using preemption we keep forcing a task switch to\r
1402                         see if any other task has become available.  If we are using\r
1403                         preemption we don't need to do this as any task becoming available\r
1404                         will automatically get the processor anyway. */\r
1405                         taskYIELD();    \r
1406                 }\r
1407                 #endif\r
1408 \r
1409                 #if ( ( configUSE_PREEMPTION == 1 ) && ( configIDLE_SHOULD_YIELD == 1 ) )\r
1410                 {\r
1411                         /* When using preemption tasks of equal priority will be\r
1412                         timesliced.  If a task that is sharing the idle priority is ready\r
1413                         to run then the idle task should yield before the end of the\r
1414                         timeslice.\r
1415                         \r
1416                         A critical region is not required here as we are just reading from\r
1417                         the list, and an occasional incorrect value will not matter.  If\r
1418                         the ready list at the idle priority contains more than one task\r
1419                         then a task other than the idle task is ready to execute. */\r
1420                         if( listCURRENT_LIST_LENGTH( &( pxReadyTasksLists[ tskIDLE_PRIORITY ] ) ) > ( unsigned portBASE_TYPE ) 1 )\r
1421                         {\r
1422                                 taskYIELD();\r
1423                         }\r
1424                 }\r
1425                 #endif\r
1426 \r
1427                 #if ( configUSE_IDLE_HOOK == 1 )\r
1428                 {\r
1429                         extern void vApplicationIdleHook( void );\r
1430 \r
1431                         /* Call the user defined function from within the idle task.  This\r
1432                         allows the application designer to add background functionality\r
1433                         without the overhead of a separate task.\r
1434                         NOTE: vApplicationIdleHook() MUST NOT, UNDER ANY CIRCUMSTANCES,\r
1435                         CALL A FUNCTION THAT MIGHT BLOCK. */\r
1436                         vApplicationIdleHook();\r
1437                 }\r
1438                 #endif\r
1439         }\r
1440 } /*lint !e715 pvParameters is not accessed but all task functions require the same prototype. */\r
1441 \r
1442 \r
1443 \r
1444 \r
1445 \r
1446 \r
1447 \r
1448 /*-----------------------------------------------------------\r
1449  * File private functions documented at the top of the file.\r
1450  *----------------------------------------------------------*/\r
1451 \r
1452 \r
1453 \r
1454 static void prvInitialiseTCBVariables( tskTCB *pxTCB, unsigned portSHORT usStackDepth, const signed portCHAR * const pcName, unsigned portBASE_TYPE uxPriority )\r
1455 {\r
1456         pxTCB->usStackDepth = usStackDepth;\r
1457 \r
1458         /* Store the function name in the TCB. */\r
1459         strncpy( ( char * ) pxTCB->pcTaskName, ( const char * ) pcName, ( unsigned portSHORT ) configMAX_TASK_NAME_LEN );\r
1460         pxTCB->pcTaskName[ ( unsigned portSHORT ) configMAX_TASK_NAME_LEN - ( unsigned portSHORT ) 1 ] = '\0';\r
1461 \r
1462         /* This is used as an array index so must ensure it's not too large. */\r
1463         if( uxPriority >= configMAX_PRIORITIES )\r
1464         {\r
1465                 uxPriority = configMAX_PRIORITIES - 1;\r
1466         }\r
1467 \r
1468         pxTCB->uxPriority = uxPriority;\r
1469 \r
1470         vListInitialiseItem( &( pxTCB->xGenericListItem ) );\r
1471         vListInitialiseItem( &( pxTCB->xEventListItem ) );\r
1472 \r
1473         /* Set the pxTCB as a link back from the xListItem.  This is so we can get\r
1474         back to the containing TCB from a generic item in a list. */\r
1475         listSET_LIST_ITEM_OWNER( &( pxTCB->xGenericListItem ), pxTCB );\r
1476 \r
1477         /* Event lists are always in priority order. */\r
1478         listSET_LIST_ITEM_VALUE( &( pxTCB->xEventListItem ), configMAX_PRIORITIES - ( portTickType ) uxPriority );\r
1479         listSET_LIST_ITEM_OWNER( &( pxTCB->xEventListItem ), pxTCB );\r
1480 }\r
1481 /*-----------------------------------------------------------*/\r
1482 \r
1483 static void prvInitialiseTaskLists( void )\r
1484 {\r
1485 unsigned portBASE_TYPE uxPriority;\r
1486 \r
1487         for( uxPriority = 0; uxPriority < configMAX_PRIORITIES; uxPriority++ )\r
1488         {\r
1489                 vListInitialise( ( xList * ) &( pxReadyTasksLists[ uxPriority ] ) );\r
1490         }\r
1491 \r
1492         vListInitialise( ( xList * ) &xDelayedTaskList1 );\r
1493         vListInitialise( ( xList * ) &xDelayedTaskList2 );\r
1494         vListInitialise( ( xList * ) &xPendingReadyList );\r
1495 \r
1496         #if ( INCLUDE_vTaskDelete == 1 )\r
1497         {\r
1498                 vListInitialise( ( xList * ) &xTasksWaitingTermination );\r
1499         }\r
1500         #endif\r
1501 \r
1502         #if ( INCLUDE_vTaskSuspend == 1 )\r
1503         {\r
1504                 vListInitialise( ( xList * ) &xSuspendedTaskList );\r
1505         }\r
1506         #endif\r
1507 \r
1508         /* Start with pxDelayedTaskList using list1 and the pxOverflowDelayedTaskList\r
1509         using list2. */\r
1510         pxDelayedTaskList = &xDelayedTaskList1;\r
1511         pxOverflowDelayedTaskList = &xDelayedTaskList2;\r
1512 }\r
1513 /*-----------------------------------------------------------*/\r
1514 \r
1515 static void prvCheckTasksWaitingTermination( void )\r
1516 {                                                       \r
1517         #if ( INCLUDE_vTaskDelete == 1 )\r
1518         {                               \r
1519                 portBASE_TYPE xListIsEmpty;\r
1520 \r
1521                 /* ucTasksDeleted is used to prevent vTaskSuspendAll() being called\r
1522                 too often in the idle task. */\r
1523                 if( uxTasksDeleted > ( unsigned portBASE_TYPE ) 0 )\r
1524                 {\r
1525                         vTaskSuspendAll();\r
1526                                 xListIsEmpty = listLIST_IS_EMPTY( &xTasksWaitingTermination );                          \r
1527                         xTaskResumeAll();\r
1528 \r
1529                         if( !xListIsEmpty )\r
1530                         {\r
1531                                 tskTCB *pxTCB;\r
1532 \r
1533                                 portENTER_CRITICAL();\r
1534                                 {                       \r
1535                                         pxTCB = ( tskTCB * ) listGET_OWNER_OF_HEAD_ENTRY( ( ( xList * ) &xTasksWaitingTermination ) );\r
1536                                         vListRemove( &( pxTCB->xGenericListItem ) );\r
1537                                         --uxCurrentNumberOfTasks;\r
1538                                         --uxTasksDeleted;\r
1539                                 }\r
1540                                 portEXIT_CRITICAL();\r
1541 \r
1542                                 prvDeleteTCB( pxTCB );\r
1543                         }\r
1544                 }\r
1545         }\r
1546         #endif\r
1547 }\r
1548 /*-----------------------------------------------------------*/\r
1549 \r
1550 static tskTCB *prvAllocateTCBAndStack( unsigned portSHORT usStackDepth )\r
1551 {\r
1552 tskTCB *pxNewTCB;\r
1553 \r
1554         /* Allocate space for the TCB.  Where the memory comes from depends on\r
1555         the implementation of the port malloc function. */\r
1556         pxNewTCB = ( tskTCB * ) pvPortMalloc( sizeof( tskTCB ) );\r
1557 \r
1558         if( pxNewTCB != NULL )\r
1559         {\r
1560                 /* Allocate space for the stack used by the task being created.\r
1561                 The base of the stack memory stored in the TCB so the task can\r
1562                 be deleted later if required. */\r
1563                 pxNewTCB->pxStack = ( portSTACK_TYPE * ) pvPortMalloc( ( ( size_t )usStackDepth ) * sizeof( portSTACK_TYPE ) );\r
1564 \r
1565                 if( pxNewTCB->pxStack == NULL )\r
1566                 {\r
1567                         /* Could not allocate the stack.  Delete the allocated TCB. */\r
1568                         vPortFree( pxNewTCB );                  \r
1569                         pxNewTCB = NULL;                        \r
1570                 }               \r
1571                 else\r
1572                 {\r
1573                         /* Just to help debugging. */\r
1574                         memset( pxNewTCB->pxStack, tskSTACK_FILL_BYTE, usStackDepth * sizeof( portSTACK_TYPE ) );\r
1575                 }\r
1576         }\r
1577 \r
1578         return pxNewTCB;\r
1579 }\r
1580 /*-----------------------------------------------------------*/\r
1581 \r
1582 #if ( configUSE_TRACE_FACILITY == 1 )\r
1583 \r
1584         static void prvListTaskWithinSingleList( signed portCHAR *pcWriteBuffer, xList *pxList, signed portCHAR cStatus )\r
1585         {\r
1586         volatile tskTCB *pxNextTCB, *pxFirstTCB;\r
1587         static portCHAR pcStatusString[ 50 ];\r
1588         unsigned portSHORT usStackRemaining;\r
1589 \r
1590                 /* Write the details of all the TCB's in pxList into the buffer. */\r
1591                 listGET_OWNER_OF_NEXT_ENTRY( pxFirstTCB, pxList );\r
1592                 do\r
1593                 {\r
1594                         listGET_OWNER_OF_NEXT_ENTRY( pxNextTCB, pxList );\r
1595                         usStackRemaining = usTaskCheckFreeStackSpace( ( unsigned portCHAR * ) pxNextTCB->pxStack );\r
1596                         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
1597                         strcat( ( portCHAR * ) pcWriteBuffer, ( portCHAR * ) pcStatusString );\r
1598 \r
1599                 } while( pxNextTCB != pxFirstTCB );\r
1600         }\r
1601 \r
1602 #endif\r
1603 /*-----------------------------------------------------------*/\r
1604 \r
1605 #if ( configUSE_TRACE_FACILITY == 1 )\r
1606         unsigned portSHORT usTaskCheckFreeStackSpace( const unsigned portCHAR *pucStackByte )\r
1607         {\r
1608         register unsigned portSHORT usCount = 0;\r
1609 \r
1610                 while( *pucStackByte == tskSTACK_FILL_BYTE )\r
1611                 {\r
1612                         pucStackByte -= portSTACK_GROWTH;\r
1613                         usCount++;\r
1614                 }\r
1615 \r
1616                 usCount /= sizeof( portSTACK_TYPE );\r
1617 \r
1618                 return usCount;\r
1619         }\r
1620 #endif\r
1621 /*-----------------------------------------------------------*/\r
1622 \r
1623 \r
1624 \r
1625 #if ( ( INCLUDE_vTaskDelete == 1 ) || ( INCLUDE_vTaskCleanUpResources == 1 ) )\r
1626 \r
1627         static void prvDeleteTCB( tskTCB *pxTCB )\r
1628         {\r
1629                 /* Free up the memory allocated by the scheduler for the task.  It is up to\r
1630                 the task to free any memory allocated at the application level. */\r
1631                 vPortFree( pxTCB->pxStack );\r
1632                 vPortFree( pxTCB );\r
1633         }\r
1634 \r
1635 #endif\r
1636 \r
1637 \r
1638 /*-----------------------------------------------------------*/\r
1639 \r
1640 #if ( INCLUDE_xTaskGetCurrentTaskHandle == 1 )\r
1641 \r
1642         xTaskHandle xTaskGetCurrentTaskHandle( void )\r
1643         {\r
1644         xTaskHandle xReturn;\r
1645 \r
1646                 portENTER_CRITICAL();\r
1647                 {\r
1648                         xReturn = ( xTaskHandle ) pxCurrentTCB;\r
1649                 }\r
1650                 portEXIT_CRITICAL();\r
1651 \r
1652                 return xReturn;\r
1653         }\r
1654 \r
1655 #endif\r
1656 \r
1657 \r
1658 \r
1659 \r
1660 \r