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

   1 /*\r
   2         FreeRTOS.org V4.0.2 - Copyright (C) 2003-2006 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         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 Changes from V4.0.1\r
 154 \r
 155         + The function vTaskList() now suspends the scheduler rather than disabling\r
 156           interrups during the creation of the task list.  \r
 157         + Allow a task to delete itself by passing in its own handle.  Previously \r
 158           this could only be done by passing in NULL.\r
 159         + The tick hook function is now called only within a tick isr.  Previously\r
 160           it was also called when the tick function was called during the scheduler\r
 161           unlocking process.\r
 162 */\r
 163 \r
 164 #include <stdio.h>\r
 165 #include <stdlib.h>\r
 166 #include <string.h>\r
 167 \r
 168 #include "FreeRTOS.h"\r
 169 #include "task.h"\r
 170 \r
 171 /*\r
 172  * Macro to define the amount of stack available to the idle task.\r
 173  */\r
 174 #define tskIDLE_STACK_SIZE      configMINIMAL_STACK_SIZE\r
 175 \r
 176 \r
 177 /*\r
 178  * Default a definitions for backwards compatibility with old\r
 179  * portmacro.h files.\r
 180  */\r
 181 #ifndef configMAX_TASK_NAME_LEN\r
 182         #define configMAX_TASK_NAME_LEN 16\r
 183 #endif\r
 184 \r
 185 #ifndef INCLUDE_xTaskGetCurrentTaskHandle\r
 186         #define INCLUDE_xTaskGetCurrentTaskHandle 0\r
 187 #endif\r
 188 \r
 189 #ifndef configIDLE_SHOULD_YIELD\r
 190         #define configIDLE_SHOULD_YIELD         1\r
 191 #endif\r
 192 \r
 193 #if configMAX_TASK_NAME_LEN < 1\r
 194         #undef configMAX_TASK_NAME_LEN\r
 195         #define configMAX_TASK_NAME_LEN 1\r
 196 #endif\r
 197 \r
 198 \r
 199 /*\r
 200  * Task control block.  A task control block (TCB) is allocated to each task,\r
 201  * and stores the context of the task.\r
 202  */\r
 203 typedef struct tskTaskControlBlock\r
 204 {\r
 205         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
 206         xListItem                               xGenericListItem;       /*< List item used to place the TCB in ready and blocked queues. */\r
 207         xListItem                               xEventListItem;         /*< List item used to place the TCB in event lists. */\r
 208         unsigned portBASE_TYPE  uxPriority;                     /*< The priority of the task where 0 is the lowest priority. */\r
 209         portSTACK_TYPE                  *pxStack;                       /*< Points to the start of the stack. */\r
 210         unsigned portBASE_TYPE  uxTCBNumber;            /*< This is used for tracing the scheduler and making debugging easier only. */\r
 211         signed portCHAR                 pcTaskName[ configMAX_TASK_NAME_LEN ];/*< Descriptive name given to the task when created.  Facilitates debugging only. */\r
 212         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
 213 } tskTCB;\r
 214 \r
 215 /*lint -e956 */\r
 216 \r
 217 tskTCB * volatile pxCurrentTCB = NULL;                                  \r
 218 \r
 219 /* Lists for ready and blocked tasks. --------------------*/\r
 220 \r
 221 static xList pxReadyTasksLists[ configMAX_PRIORITIES ]; /*< Prioritised ready tasks. */\r
 222 static xList xDelayedTaskList1;                                                 /*< Delayed tasks. */\r
 223 static xList xDelayedTaskList2;                                                 /*< Delayed tasks (two lists are used - one for delays that have overflowed the current tick count. */\r
 224 static xList * volatile pxDelayedTaskList;                              /*< Points to the delayed task list currently being used. */\r
 225 static xList * volatile pxOverflowDelayedTaskList;              /*< Points to the delayed task list currently being used to hold tasks that have overflowed the current tick count. */\r
 226 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
 227 \r
 228 #if ( INCLUDE_vTaskDelete == 1 )\r
 229 \r
 230         static volatile xList xTasksWaitingTermination;         /*< Tasks that have been deleted - but the their memory not yet freed. */\r
 231         static volatile unsigned portBASE_TYPE uxTasksDeleted = ( unsigned portBASE_TYPE ) 0;\r
 232 \r
 233 #endif\r
 234 \r
 235 #if ( INCLUDE_vTaskSuspend == 1 )\r
 236 \r
 237         static xList xSuspendedTaskList;                                        /*< Tasks that are currently suspended. */\r
 238 \r
 239 #endif\r
 240 \r
 241 /* File private variables. --------------------------------*/\r
 242 static volatile unsigned portBASE_TYPE uxCurrentNumberOfTasks   = ( unsigned portBASE_TYPE ) 0;\r
 243 static volatile portTickType xTickCount                                                 = ( portTickType ) 0;\r
 244 static unsigned portBASE_TYPE uxTopUsedPriority                         = tskIDLE_PRIORITY;\r
 245 static volatile unsigned portBASE_TYPE uxTopReadyPriority               = tskIDLE_PRIORITY;\r
 246 static volatile signed portBASE_TYPE xSchedulerRunning                  = pdFALSE;\r
 247 static volatile unsigned portBASE_TYPE uxSchedulerSuspended             = ( unsigned portBASE_TYPE ) pdFALSE;\r
 248 static volatile unsigned portBASE_TYPE uxMissedTicks                    = ( unsigned portBASE_TYPE ) 0;\r
 249 static volatile portBASE_TYPE xMissedYield                                              = ( portBASE_TYPE ) pdFALSE;\r
 250 \r
 251 /* Debugging and trace facilities private variables and macros. ------------*/\r
 252 \r
 253 /*\r
 254  * The value used to fill the stack of a task when the task is created.  This\r
 255  * is used purely for checking the high water mark for tasks.\r
 256  */\r
 257 #define tskSTACK_FILL_BYTE      ( 0xa5 )\r
 258 \r
 259 /*\r
 260  * Macros used by vListTask to indicate which state a task is in.\r
 261  */\r
 262 #define tskBLOCKED_CHAR         ( ( signed portCHAR ) 'B' )\r
 263 #define tskREADY_CHAR           ( ( signed portCHAR ) 'R' )\r
 264 #define tskDELETED_CHAR         ( ( signed portCHAR ) 'D' )\r
 265 #define tskSUSPENDED_CHAR       ( ( signed portCHAR ) 'S' )\r
 266 \r
 267 /*\r
 268  * Macros and private variables used by the trace facility.\r
 269  */\r
 270 #if ( configUSE_TRACE_FACILITY == 1 )\r
 271 \r
 272         #define tskSIZE_OF_EACH_TRACE_LINE                      ( ( unsigned portLONG ) ( sizeof( unsigned portLONG ) + sizeof( unsigned portLONG ) ) )\r
 273         static volatile signed portCHAR * volatile pcTraceBuffer;\r
 274         static signed portCHAR *pcTraceBufferStart;\r
 275         static signed portCHAR *pcTraceBufferEnd;\r
 276         static signed portBASE_TYPE xTracing = pdFALSE;\r
 277 \r
 278 #endif\r
 279 \r
 280 /*\r
 281  * Macro that writes a trace of scheduler activity to a buffer.  This trace\r
 282  * shows which task is running when and is very useful as a debugging tool.\r
 283  * As this macro is called each context switch it is a good idea to undefine\r
 284  * it if not using the facility.\r
 285  */\r
 286 #if ( configUSE_TRACE_FACILITY == 1 )\r
 287 \r
 288         #define vWriteTraceToBuffer()                                                                                                           \\r
 289         {                                                                                                                                                                       \\r
 290                 if( xTracing )                                                                                                                                  \\r
 291                 {                                                                                                                                                               \\r
 292                         static unsigned portBASE_TYPE uxPreviousTask = 255;                                                     \\r
 293                                                                                                                                                                                 \\r
 294                         if( uxPreviousTask != pxCurrentTCB->uxTCBNumber )                                                       \\r
 295                         {                                                                                                                                                       \\r
 296                                 if( ( pcTraceBuffer + tskSIZE_OF_EACH_TRACE_LINE ) < pcTraceBufferEnd ) \\r
 297                                 {                                                                                                                                               \\r
 298                                         uxPreviousTask = pxCurrentTCB->uxTCBNumber;                                                     \\r
 299                                         *( unsigned portLONG * ) pcTraceBuffer = ( unsigned portLONG ) xTickCount;              \\r
 300                                         pcTraceBuffer += sizeof( unsigned portLONG );                                           \\r
 301                                         *( unsigned portLONG * ) pcTraceBuffer = ( unsigned portLONG ) uxPreviousTask;  \\r
 302                                         pcTraceBuffer += sizeof( unsigned portLONG );                                           \\r
 303                                 }                                                                                                                                               \\r
 304                                 else                                                                                                                                    \\r
 305                                 {                                                                                                                                               \\r
 306                                         xTracing = pdFALSE;                                                                                                     \\r
 307                                 }                                                                                                                                               \\r
 308                         }                                                                                                                                                       \\r
 309                 }                                                                                                                                                               \\r
 310         }\r
 311 \r
 312 #else\r
 313 \r
 314         #define vWriteTraceToBuffer()\r
 315 \r
 316 #endif\r
 317 \r
 318 \r
 319 /*\r
 320  * Place the task represented by pxTCB into the appropriate ready queue for\r
 321  * the task.  It is inserted at the end of the list.  One quirk of this is\r
 322  * that if the task being inserted is at the same priority as the currently\r
 323  * executing task, then it will only be rescheduled after the currently\r
 324  * executing task has been rescheduled.\r
 325  */\r
 326 #define prvAddTaskToReadyQueue( pxTCB )                                                                                                                                                 \\r
 327 {                                                                                                                                                                                                                               \\r
 328         if( pxTCB->uxPriority > uxTopReadyPriority )                                                                                                                            \\r
 329         {                                                                                                                                                                                                                       \\r
 330                 uxTopReadyPriority = pxTCB->uxPriority;                                                                                                                                 \\r
 331         }                                                                                                                                                                                                                       \\r
 332         vListInsertEnd( ( xList * ) &( pxReadyTasksLists[ pxTCB->uxPriority ] ), &( pxTCB->xGenericListItem ) );        \\r
 333 }       \r
 334 \r
 335 \r
 336 /*\r
 337  * Macro that looks at the list of tasks that are currently delayed to see if\r
 338  * any require waking.\r
 339  *\r
 340  * Tasks are stored in the queue in the order of their wake time - meaning\r
 341  * once one tasks has been found whose timer has not expired we need not look\r
 342  * any further down the list.\r
 343  */\r
 344 #define prvCheckDelayedTasks()                                                                                                                                  \\r
 345 {                                                                                                                                                                                               \\r
 346 register tskTCB *pxTCB;                                                                                                                                                 \\r
 347                                                                                                                                                                                                 \\r
 348         while( ( pxTCB = ( tskTCB * ) listGET_OWNER_OF_HEAD_ENTRY( pxDelayedTaskList ) ) != NULL )      \\r
 349         {                                                                                                                                                                                       \\r
 350                 if( xTickCount < listGET_LIST_ITEM_VALUE( &( pxTCB->xGenericListItem ) ) )                              \\r
 351                 {                                                                                                                                                                               \\r
 352                         break;                                                                                                                                                          \\r
 353                 }                                                                                                                                                                               \\r
 354                 vListRemove( &( pxTCB->xGenericListItem ) );                                                                                    \\r
 355                 /* Is the task waiting on an event also? */                                                                                             \\r
 356                 if( pxTCB->xEventListItem.pvContainer )                                                                                                 \\r
 357                 {                                                                                                                                                                               \\r
 358                         vListRemove( &( pxTCB->xEventListItem ) );                                                                                      \\r
 359                 }                                                                                                                                                                               \\r
 360                 prvAddTaskToReadyQueue( pxTCB );                                                                                                                \\r
 361         }                                                                                                                                                                                       \\r
 362 }                                                                                                                                                                                       \r
 363 \r
 364 /*\r
 365  * Several functions take an xTaskHandle parameter that can optionally be NULL,\r
 366  * where NULL is used to indicate that the handle of the currently executing\r
 367  * task should be used in place of the parameter.  This macro simply checks to\r
 368  * see if the parameter is NULL and returns a pointer to the appropriate TCB.\r
 369  */\r
 370 #define prvGetTCBFromHandle( pxHandle ) ( ( pxHandle == NULL ) ? ( tskTCB * ) pxCurrentTCB : ( tskTCB * ) pxHandle )\r
 371 \r
 372 \r
 373 /* File private functions. --------------------------------*/\r
 374 \r
 375 /*\r
 376  * Utility to ready a TCB for a given task.  Mainly just copies the parameters\r
 377  * into the TCB structure.\r
 378  */\r
 379 static void prvInitialiseTCBVariables( tskTCB *pxTCB, unsigned portSHORT usStackDepth, const signed portCHAR * const pcName, unsigned portBASE_TYPE uxPriority );\r
 380 \r
 381 /*\r
 382  * Utility to ready all the lists used by the scheduler.  This is called\r
 383  * automatically upon the creation of the first task.\r
 384  */\r
 385 static void prvInitialiseTaskLists( void );\r
 386 \r
 387 /*\r
 388  * The idle task, which as all tasks is implemented as a never ending loop.\r
 389  * The idle task is automatically created and added to the ready lists upon\r
 390  * creation of the first user task.\r
 391  *\r
 392  * The portTASK_FUNCTION_PROTO() macro is used to allow port/compiler specific\r
 393  * language extensions.  The equivalent prototype for this function is:\r
 394  *\r
 395  * void prvIdleTask( void *pvParameters );\r
 396  *\r
 397  */\r
 398 static portTASK_FUNCTION_PROTO( prvIdleTask, pvParameters );\r
 399 \r
 400 /*\r
 401  * Utility to free all memory allocated by the scheduler to hold a TCB,\r
 402  * including the stack pointed to by the TCB.\r
 403  *\r
 404  * This does not free memory allocated by the task itself (i.e. memory\r
 405  * allocated by calls to pvPortMalloc from within the tasks application code).\r
 406  */\r
 407 #if ( ( INCLUDE_vTaskDelete == 1 ) || ( INCLUDE_vTaskCleanUpResources == 1 ) )\r
 408         static void prvDeleteTCB( tskTCB *pxTCB );\r
 409 #endif\r
 410 \r
 411 /*\r
 412  * Used only by the idle task.  This checks to see if anything has been placed\r
 413  * in the list of tasks waiting to be deleted.  If so the task is cleaned up\r
 414  * and its TCB deleted.\r
 415  */\r
 416 static void prvCheckTasksWaitingTermination( void );\r
 417 \r
 418 /*\r
 419  * Allocates memory from the heap for a TCB and associated stack.  Checks the\r
 420  * allocation was successful.\r
 421  */\r
 422 static tskTCB *prvAllocateTCBAndStack( unsigned portSHORT usStackDepth );\r
 423 \r
 424 /*\r
 425  * Called from vTaskList.  vListTasks details all the tasks currently under\r
 426  * control of the scheduler.  The tasks may be in one of a number of lists.\r
 427  * prvListTaskWithinSingleList accepts a list and details the tasks from\r
 428  * within just that list.\r
 429  *\r
 430  * THIS FUNCTION IS INTENDED FOR DEBUGGING ONLY, AND SHOULD NOT BE CALLED FROM\r
 431  * NORMAL APPLICATION CODE.\r
 432  */\r
 433 #if ( configUSE_TRACE_FACILITY == 1 )\r
 434 \r
 435         static void prvListTaskWithinSingleList( signed portCHAR *pcWriteBuffer, xList *pxList, signed portCHAR cStatus );\r
 436 \r
 437 #endif\r
 438 \r
 439 /*\r
 440  * When a task is created, the stack of the task is filled with a known value.\r
 441  * This function determines the 'high water mark' of the task stack by\r
 442  * determining how much of the stack remains at the original preset value.\r
 443  */\r
 444 #if ( configUSE_TRACE_FACILITY == 1 )\r
 445 \r
 446         unsigned portSHORT usTaskCheckFreeStackSpace( const unsigned portCHAR *pucStackByte );\r
 447 \r
 448 #endif\r
 449 \r
 450 /*lint +e956 */\r
 451 \r
 452 \r
 453 \r
 454 \r
 455 \r
 456 /*-----------------------------------------------------------\r
 457  * TASK CREATION API documented in task.h\r
 458  *----------------------------------------------------------*/\r
 459 \r
 460 signed portBASE_TYPE xTaskCreate( pdTASK_CODE pvTaskCode, const signed portCHAR * const pcName, unsigned portSHORT usStackDepth, void *pvParameters, unsigned portBASE_TYPE uxPriority, xTaskHandle *pxCreatedTask )\r
 461 {\r
 462 signed portBASE_TYPE xReturn;\r
 463 tskTCB * pxNewTCB;\r
 464 static unsigned portBASE_TYPE uxTaskNumber = 0; /*lint !e956 Static is deliberate - this is guarded before use. */\r
 465 \r
 466         /* Allocate the memory required by the TCB and stack for the new task.\r
 467         checking that the allocation was successful. */\r
 468         pxNewTCB = prvAllocateTCBAndStack( usStackDepth );\r
 469 \r
 470         if( pxNewTCB != NULL )\r
 471         {               \r
 472                 portSTACK_TYPE *pxTopOfStack;\r
 473 \r
 474                 /* Setup the newly allocated TCB with the initial state of the task. */\r
 475                 prvInitialiseTCBVariables( pxNewTCB, usStackDepth, pcName, uxPriority );\r
 476 \r
 477                 /* Calculate the top of stack address.  This depends on whether the\r
 478                 stack grows from high memory to low (as per the 80x86) or visa versa.\r
 479                 portSTACK_GROWTH is used to make the result positive or negative as\r
 480                 required by the port. */\r
 481                 #if portSTACK_GROWTH < 0\r
 482                 {\r
 483                         pxTopOfStack = pxNewTCB->pxStack + ( pxNewTCB->usStackDepth - 1 );\r
 484                 }\r
 485                 #else\r
 486                 {\r
 487                         pxTopOfStack = pxNewTCB->pxStack;       \r
 488                 }\r
 489                 #endif\r
 490 \r
 491                 /* Initialize the TCB stack to look as if the task was already running,\r
 492                 but had been interrupted by the scheduler.  The return address is set\r
 493                 to the start of the task function. Once the stack has been initialised\r
 494                 the     top of stack variable is updated. */\r
 495                 pxNewTCB->pxTopOfStack = pxPortInitialiseStack( pxTopOfStack, pvTaskCode, pvParameters );\r
 496 \r
 497                 /* We are going to manipulate the task queues to add this task to a\r
 498                 ready list, so must make sure no interrupts occur. */\r
 499                 portENTER_CRITICAL();\r
 500                 {\r
 501                         uxCurrentNumberOfTasks++;\r
 502                         if( uxCurrentNumberOfTasks == ( unsigned portBASE_TYPE ) 1 )\r
 503                         {\r
 504                                 /* As this is the first task it must also be the current task. */\r
 505                                 pxCurrentTCB =  pxNewTCB;\r
 506 \r
 507                                 /* This is the first task to be created so do the preliminary\r
 508                                 initialisation required.  We will not recover if this call\r
 509                                 fails, but we will report the failure. */\r
 510                                 prvInitialiseTaskLists();\r
 511                         }\r
 512                         else\r
 513                         {       \r
 514                                 /* If the scheduler is not already running, make this task the\r
 515                                 current task if it is the highest priority task to be created\r
 516                                 so far. */\r
 517                                 if( xSchedulerRunning == pdFALSE )\r
 518                                 {\r
 519                                         if( pxCurrentTCB->uxPriority <= uxPriority )\r
 520                                         {\r
 521                                                 pxCurrentTCB = pxNewTCB;        \r
 522                                         }\r
 523                                 }\r
 524                         }                               \r
 525 \r
 526                         /* Remember the top priority to make context switching faster.  Use\r
 527                         the priority in pxNewTCB as this has been capped to a valid value. */\r
 528                         if( pxNewTCB->uxPriority > uxTopUsedPriority )\r
 529                         {\r
 530                                 uxTopUsedPriority = pxNewTCB->uxPriority;\r
 531                         }\r
 532 \r
 533                         /* Add a counter into the TCB for tracing only. */\r
 534                         pxNewTCB->uxTCBNumber = uxTaskNumber;\r
 535                         uxTaskNumber++;\r
 536 \r
 537                         prvAddTaskToReadyQueue( pxNewTCB );\r
 538 \r
 539                         xReturn = pdPASS;\r
 540                 }\r
 541                 portEXIT_CRITICAL();\r
 542         }\r
 543         else\r
 544         {\r
 545                 xReturn = errCOULD_NOT_ALLOCATE_REQUIRED_MEMORY;\r
 546         }\r
 547 \r
 548         if( xReturn == pdPASS )\r
 549         {\r
 550                 if( ( void * ) pxCreatedTask != NULL )\r
 551                 {\r
 552                         /* Pass the TCB out - in an anonymous way.  The calling function/\r
 553                         task can use this as a handle to delete the task later if\r
 554                         required.*/\r
 555                         *pxCreatedTask = ( xTaskHandle ) pxNewTCB;\r
 556                 }\r
 557 \r
 558                 if( xSchedulerRunning != pdFALSE )\r
 559                 {\r
 560                         /* If the created task is of a higher priority than the current task\r
 561                         then it should run now. */\r
 562                         if( pxCurrentTCB->uxPriority < uxPriority )\r
 563                         {\r
 564                                 taskYIELD();\r
 565                         }\r
 566                 }\r
 567         }\r
 568 \r
 569         return xReturn;\r
 570 }\r
 571 /*-----------------------------------------------------------*/\r
 572 \r
 573 #if ( INCLUDE_vTaskDelete == 1 )\r
 574 \r
 575         void vTaskDelete( xTaskHandle pxTaskToDelete )\r
 576         {\r
 577         tskTCB *pxTCB;\r
 578 \r
 579                 taskENTER_CRITICAL();\r
 580                 {\r
 581                         /* Ensure a yield is performed if the current task is being \r
 582                         deleted. */\r
 583                         if( pxTaskToDelete == pxCurrentTCB )\r
 584                         {\r
 585                                 pxTaskToDelete = NULL;\r
 586                         }\r
 587 \r
 588                         /* If null is passed in here then we are deleting ourselves. */\r
 589                         pxTCB = prvGetTCBFromHandle( pxTaskToDelete );\r
 590 \r
 591                         /* Remove task from the ready list and place in the     termination list.\r
 592                         This will stop the task from be scheduled.  The idle task will check\r
 593                         the termination list and free up any memory allocated by the\r
 594                         scheduler for the TCB and stack. */\r
 595                         vListRemove( &( pxTCB->xGenericListItem ) );\r
 596 \r
 597                         /* Is the task waiting on an event also? */                                                                                             \r
 598                         if( pxTCB->xEventListItem.pvContainer )\r
 599                         {\r
 600                                 vListRemove( &( pxTCB->xEventListItem ) );\r
 601                         }\r
 602 \r
 603                         vListInsertEnd( ( xList * ) &xTasksWaitingTermination, &( pxTCB->xGenericListItem ) );\r
 604 \r
 605                         /* Increment the ucTasksDeleted variable so the idle task knows\r
 606                         there is a task that has been deleted and that it should therefore\r
 607                         check the xTasksWaitingTermination list. */\r
 608                         ++uxTasksDeleted;\r
 609                 }\r
 610                 taskEXIT_CRITICAL();\r
 611 \r
 612                 /* Force a reschedule if we have just deleted the current task. */\r
 613                 if( ( void * ) pxTaskToDelete == NULL )\r
 614                 {\r
 615                         taskYIELD();\r
 616                 }\r
 617         }\r
 618 \r
 619 #endif\r
 620 \r
 621 \r
 622 \r
 623 \r
 624 \r
 625 \r
 626 /*-----------------------------------------------------------\r
 627  * TASK CONTROL API documented in task.h\r
 628  *----------------------------------------------------------*/\r
 629 \r
 630 #if ( INCLUDE_vTaskDelayUntil == 1 )\r
 631 \r
 632         void vTaskDelayUntil( portTickType *pxPreviousWakeTime, portTickType xTimeIncrement )\r
 633         {\r
 634         portTickType xTimeToWake;\r
 635         portBASE_TYPE xAlreadyYielded, xShouldDelay = pdFALSE;\r
 636 \r
 637                 vTaskSuspendAll();\r
 638                 {\r
 639                         /* Generate the tick time at which the task wants to wake. */\r
 640                         xTimeToWake = *pxPreviousWakeTime + xTimeIncrement;\r
 641 \r
 642                         if( xTickCount < *pxPreviousWakeTime )\r
 643                         {\r
 644                                 /* The tick count has overflowed since this function was\r
 645                                 lasted called.  In this case the only time we should ever\r
 646                                 actually delay is if the wake time has also     overflowed,\r
 647                                 and the wake time is greater than the tick time.  When this\r
 648                                 is the case it is as if neither time had overflowed. */\r
 649                                 if( ( xTimeToWake < *pxPreviousWakeTime ) && ( xTimeToWake > xTickCount ) )\r
 650                                 {\r
 651                                         xShouldDelay = pdTRUE;\r
 652                                 }\r
 653                         }\r
 654                         else\r
 655                         {\r
 656                                 /* The tick time has not overflowed.  In this case we will\r
 657                                 delay if either the wake time has overflowed, and/or the\r
 658                                 tick time is less than the wake time. */\r
 659                                 if( ( xTimeToWake < *pxPreviousWakeTime ) || ( xTimeToWake > xTickCount ) )\r
 660                                 {\r
 661                                         xShouldDelay = pdTRUE;\r
 662                                 }\r
 663                         }\r
 664 \r
 665                         /* Update the wake time ready for the next call. */\r
 666                         *pxPreviousWakeTime = xTimeToWake;\r
 667 \r
 668                         if( xShouldDelay )\r
 669                         {\r
 670                                 /* We must remove ourselves from the ready list before adding\r
 671                                 ourselves to the blocked list as the same list item is used for\r
 672                                 both lists. */\r
 673                                 vListRemove( ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );\r
 674 \r
 675                                 /* The list item will be inserted in wake time order. */\r
 676                                 listSET_LIST_ITEM_VALUE( &( pxCurrentTCB->xGenericListItem ), xTimeToWake );\r
 677 \r
 678                                 if( xTimeToWake < xTickCount )\r
 679                                 {\r
 680                                         /* Wake time has overflowed.  Place this item in the\r
 681                                         overflow list. */\r
 682                                         vListInsert( ( xList * ) pxOverflowDelayedTaskList, ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );\r
 683                                 }\r
 684                                 else\r
 685                                 {\r
 686                                         /* The wake time has not overflowed, so we can use the\r
 687                                         current block list. */\r
 688                                         vListInsert( ( xList * ) pxDelayedTaskList, ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );\r
 689                                 }\r
 690                         }\r
 691                 }\r
 692                 xAlreadyYielded = xTaskResumeAll();\r
 693 \r
 694                 /* Force a reschedule if xTaskResumeAll has not already done so, we may\r
 695                 have put ourselves to sleep. */\r
 696                 if( !xAlreadyYielded )\r
 697                 {\r
 698                         taskYIELD();\r
 699                 }\r
 700         }       \r
 701         \r
 702 #endif\r
 703 /*-----------------------------------------------------------*/\r
 704 \r
 705 #if ( INCLUDE_vTaskDelay == 1 )\r
 706 \r
 707         void vTaskDelay( portTickType xTicksToDelay )\r
 708         {\r
 709         portTickType xTimeToWake;\r
 710         signed portBASE_TYPE xAlreadyYielded = pdFALSE;\r
 711 \r
 712                 /* A delay time of zero just forces a reschedule. */\r
 713                 if( xTicksToDelay > ( portTickType ) 0 )\r
 714                 {\r
 715                         vTaskSuspendAll();\r
 716                         {\r
 717                                 /* A task that is removed from the event list while the\r
 718                                 scheduler is suspended will not get placed in the ready\r
 719                                 list or removed from the blocked list until the scheduler\r
 720                                 is resumed.\r
 721                                 \r
 722                                 This task cannot be in an event list as it is the currently\r
 723                                 executing task. */\r
 724 \r
 725                                 /* Calculate the time to wake - this may overflow but this is\r
 726                                 not a problem. */\r
 727                                 xTimeToWake = xTickCount + xTicksToDelay;\r
 728 \r
 729                                 /* We must remove ourselves from the ready list before adding\r
 730                                 ourselves to the blocked list as the same list item is used for\r
 731                                 both lists. */\r
 732                                 vListRemove( ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );\r
 733 \r
 734                                 /* The list item will be inserted in wake time order. */\r
 735                                 listSET_LIST_ITEM_VALUE( &( pxCurrentTCB->xGenericListItem ), xTimeToWake );\r
 736 \r
 737                                 if( xTimeToWake < xTickCount )\r
 738                                 {\r
 739                                         /* Wake time has overflowed.  Place this item in the\r
 740                                         overflow list. */\r
 741                                         vListInsert( ( xList * ) pxOverflowDelayedTaskList, ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );\r
 742                                 }\r
 743                                 else\r
 744                                 {\r
 745                                         /* The wake time has not overflowed, so we can use the\r
 746                                         current block list. */\r
 747                                         vListInsert( ( xList * ) pxDelayedTaskList, ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );\r
 748                                 }\r
 749                         }\r
 750                         xAlreadyYielded = xTaskResumeAll();\r
 751                 }\r
 752                 \r
 753                 /* Force a reschedule if xTaskResumeAll has not already done so, we may\r
 754                 have put ourselves to sleep. */\r
 755                 if( !xAlreadyYielded )\r
 756                 {\r
 757                         taskYIELD();\r
 758                 }\r
 759         }\r
 760         \r
 761 #endif\r
 762 /*-----------------------------------------------------------*/\r
 763 \r
 764 #if ( INCLUDE_uxTaskPriorityGet == 1 )\r
 765 \r
 766         unsigned portBASE_TYPE uxTaskPriorityGet( xTaskHandle pxTask )\r
 767         {\r
 768         tskTCB *pxTCB;\r
 769         unsigned portBASE_TYPE uxReturn;\r
 770 \r
 771                 taskENTER_CRITICAL();\r
 772                 {\r
 773                         /* If null is passed in here then we are changing the\r
 774                         priority of the calling function. */\r
 775                         pxTCB = prvGetTCBFromHandle( pxTask );\r
 776                         uxReturn = pxTCB->uxPriority;\r
 777                 }\r
 778                 taskEXIT_CRITICAL();\r
 779 \r
 780                 return uxReturn;\r
 781         }\r
 782 \r
 783 #endif\r
 784 /*-----------------------------------------------------------*/\r
 785 \r
 786 #if ( INCLUDE_vTaskPrioritySet == 1 )\r
 787 \r
 788         void vTaskPrioritySet( xTaskHandle pxTask, unsigned portBASE_TYPE uxNewPriority )\r
 789         {\r
 790         tskTCB *pxTCB;\r
 791         unsigned portBASE_TYPE uxCurrentPriority;\r
 792 \r
 793                 /* Ensure the new priority is valid. */\r
 794                 if( uxNewPriority >= configMAX_PRIORITIES )\r
 795                 {\r
 796                         uxNewPriority = configMAX_PRIORITIES - 1;\r
 797                 }\r
 798 \r
 799                 taskENTER_CRITICAL();\r
 800                 {\r
 801                         /* If null is passed in here then we are changing the\r
 802                         priority of the calling function. */\r
 803                         pxTCB = prvGetTCBFromHandle( pxTask );\r
 804                         uxCurrentPriority = pxTCB->uxPriority;\r
 805 \r
 806                         if( uxCurrentPriority != uxNewPriority )\r
 807                         {\r
 808                                 pxTCB->uxPriority = uxNewPriority;\r
 809 \r
 810                                 /* If the task is in the blocked or suspended list we need do\r
 811                                 nothing more than change it's priority variable. However, if\r
 812                                 the task is in a ready list it needs to be removed and placed\r
 813                                 in the queue appropriate to its new priority. */\r
 814                                 if( listIS_CONTAINED_WITHIN( &( pxReadyTasksLists[ uxCurrentPriority ] ), &( pxTCB->xGenericListItem ) ) )\r
 815                                 {\r
 816                                         if( uxSchedulerSuspended == ( unsigned portBASE_TYPE ) pdFALSE )\r
 817                                         {\r
 818                                                 /* The task is currently in its ready list - remove before adding\r
 819                                                 it to it's new ready list. */\r
 820                                                 vListRemove( &( pxTCB->xGenericListItem ) );\r
 821                                                 prvAddTaskToReadyQueue( pxTCB );\r
 822                                         }\r
 823                                         else\r
 824                                         {\r
 825                                                 /* We cannot access the delayed or ready lists, so will hold this\r
 826                                                 task pending until the scheduler is resumed. */\r
 827                                                 vListInsertEnd( ( xList * ) &( xPendingReadyList ), &( pxTCB->xEventListItem ) );\r
 828                                         }\r
 829                                 }                       \r
 830                         }\r
 831                 }\r
 832                 taskEXIT_CRITICAL();\r
 833 \r
 834                 /* The priority change may have readied a task of higher\r
 835                 priority than the calling task. */\r
 836                 taskYIELD();\r
 837         }\r
 838 \r
 839 #endif\r
 840 /*-----------------------------------------------------------*/\r
 841 \r
 842 #if ( INCLUDE_vTaskSuspend == 1 )\r
 843 \r
 844         void vTaskSuspend( xTaskHandle pxTaskToSuspend )\r
 845         {\r
 846         tskTCB *pxTCB;\r
 847 \r
 848                 taskENTER_CRITICAL();\r
 849                 {\r
 850                         /* Ensure a yield is performed if the current task is being \r
 851                         suspended. */\r
 852                         if( pxTaskToSuspend == pxCurrentTCB )\r
 853                         {\r
 854                                 pxTaskToSuspend = NULL;\r
 855                         }\r
 856 \r
 857                         /* If null is passed in here then we are suspending ourselves. */\r
 858                         pxTCB = prvGetTCBFromHandle( pxTaskToSuspend );\r
 859 \r
 860                         /* Remove task from the ready/delayed list and place in the     suspended list. */\r
 861                         vListRemove( &( pxTCB->xGenericListItem ) );\r
 862 \r
 863                         /* Is the task waiting on an event also? */                                                                                             \r
 864                         if( pxTCB->xEventListItem.pvContainer )\r
 865                         {\r
 866                                 vListRemove( &( pxTCB->xEventListItem ) );\r
 867                         }\r
 868 \r
 869                         vListInsertEnd( ( xList * ) &xSuspendedTaskList, &( pxTCB->xGenericListItem ) );\r
 870                 }\r
 871                 taskEXIT_CRITICAL();\r
 872 \r
 873                 /* We may have just suspended the current task. */\r
 874                 if( ( void * ) pxTaskToSuspend == NULL )\r
 875                 {\r
 876                         taskYIELD();\r
 877                 }\r
 878         }\r
 879 \r
 880 #endif\r
 881 /*-----------------------------------------------------------*/\r
 882 \r
 883 #if ( INCLUDE_vTaskSuspend == 1 )\r
 884 \r
 885         void vTaskResume( xTaskHandle pxTaskToResume )\r
 886         {\r
 887         tskTCB *pxTCB;\r
 888         portBASE_TYPE xYieldRequired;\r
 889 \r
 890                 /* Remove the task from whichever list it is currently in, and place\r
 891                 it in the ready list. */\r
 892                 pxTCB = ( tskTCB * ) pxTaskToResume;\r
 893 \r
 894                 /* The parameter cannot be NULL as it is impossible to resume the\r
 895                 currently executing task. */\r
 896                 if( pxTCB != NULL )\r
 897                 {\r
 898                         taskENTER_CRITICAL();\r
 899                         {\r
 900                                 if( uxSchedulerSuspended == ( unsigned portBASE_TYPE ) pdFALSE )\r
 901                                 {\r
 902                                         xYieldRequired = ( pxTCB->uxPriority >= pxCurrentTCB->uxPriority );\r
 903                                         vListRemove(  &( pxTCB->xGenericListItem ) );\r
 904                                         prvAddTaskToReadyQueue( pxTCB );\r
 905                                 }\r
 906                                 else\r
 907                                 {\r
 908                                         /* We cannot access the delayed or ready lists, so will hold this\r
 909                                         task pending until the scheduler is resumed. */\r
 910                                         xYieldRequired = pdFALSE;\r
 911                                         vListInsertEnd( ( xList * ) &( xPendingReadyList ), &( pxTCB->xEventListItem ) );\r
 912                                 }\r
 913                         }\r
 914                         taskEXIT_CRITICAL();\r
 915 \r
 916                         /* We may have just resumed a higher priority task. */\r
 917                         if( xYieldRequired )\r
 918                         {\r
 919                                 /* This yield may not cause the task just resumed to run, but\r
 920                                 will leave the lists in the correct state for the next yield. */\r
 921                                 taskYIELD();\r
 922                         }\r
 923                 }\r
 924         }\r
 925 \r
 926 #endif\r
 927 \r
 928 \r
 929 \r
 930 \r
 931 \r
 932 /*-----------------------------------------------------------\r
 933  * PUBLIC SCHEDULER CONTROL documented in task.h\r
 934  *----------------------------------------------------------*/\r
 935 \r
 936 \r
 937 void vTaskStartScheduler( void )\r
 938 {\r
 939 portBASE_TYPE xReturn;\r
 940 \r
 941         /* Add the idle task at the lowest priority. */\r
 942         xReturn = xTaskCreate( prvIdleTask, ( signed portCHAR * ) "IDLE", tskIDLE_STACK_SIZE, ( void * ) NULL, tskIDLE_PRIORITY, ( xTaskHandle * ) NULL );\r
 943 \r
 944         if( xReturn == pdPASS )\r
 945         {\r
 946                 /* Interrupts are turned off here, to ensure a tick does not occur\r
 947                 before or during the call to xPortStartScheduler().  The stacks of\r
 948                 the created tasks contain a status word with interrupts switched on\r
 949                 so interrupts will automatically get re-enabled when the first task\r
 950                 starts to run.\r
 951                 \r
 952                 STEPPING THROUGH HERE USING A DEBUGGER CAN CAUSE BIG PROBLEMS IF THE\r
 953                 DEBUGGER ALLOWS INTERRUPTS TO BE PROCESSED. */\r
 954                 portDISABLE_INTERRUPTS();\r
 955 \r
 956                 xSchedulerRunning = pdTRUE;\r
 957                 xTickCount = ( portTickType ) 0;\r
 958 \r
 959                 /* Setting up the timer tick is hardware specific and thus in the\r
 960                 portable interface. */\r
 961                 if( xPortStartScheduler() )\r
 962                 {\r
 963                         /* Should not reach here as if the scheduler is running the\r
 964                         function will not return. */\r
 965                 }\r
 966                 else\r
 967                 {\r
 968                         /* Should only reach here if a task calls xTaskEndScheduler(). */\r
 969                 }\r
 970         }\r
 971 }\r
 972 /*-----------------------------------------------------------*/\r
 973 \r
 974 void vTaskEndScheduler( void )\r
 975 {\r
 976         /* Stop the scheduler interrupts and call the portable scheduler end\r
 977         routine so the original ISRs can be restored if necessary.  The port\r
 978         layer must ensure interrupts enable     bit is left in the correct state. */\r
 979         portDISABLE_INTERRUPTS();\r
 980         xSchedulerRunning = pdFALSE;\r
 981         vPortEndScheduler();\r
 982 }\r
 983 /*----------------------------------------------------------*/\r
 984 \r
 985 void vTaskSuspendAll( void )\r
 986 {\r
 987         portENTER_CRITICAL();\r
 988                 ++uxSchedulerSuspended;\r
 989         portEXIT_CRITICAL();\r
 990 }\r
 991 /*----------------------------------------------------------*/\r
 992 \r
 993 signed portBASE_TYPE xTaskResumeAll( void )\r
 994 {\r
 995 register tskTCB *pxTCB;\r
 996 signed portBASE_TYPE xAlreadyYielded = pdFALSE;\r
 997 \r
 998         /* It is possible that an ISR caused a task to be removed from an event\r
 999         list while the scheduler was suspended.  If this was the case then the\r
1000         removed task will have been added to the xPendingReadyList.  Once the\r
1001         scheduler has been resumed it is safe to move all the pending ready\r
1002         tasks from this list into their appropriate ready list. */\r
1003         portENTER_CRITICAL();\r
1004         {\r
1005                 --uxSchedulerSuspended;\r
1006 \r
1007                 if( uxSchedulerSuspended == ( unsigned portBASE_TYPE ) pdFALSE )\r
1008                 {                       \r
1009                         if( uxCurrentNumberOfTasks > ( unsigned portBASE_TYPE ) 0 )\r
1010                         {\r
1011                                 portBASE_TYPE xYieldRequired = pdFALSE;\r
1012                                 \r
1013                                 /* Move any readied tasks from the pending list into the\r
1014                                 appropriate ready list. */\r
1015                                 while( ( pxTCB = ( tskTCB * ) listGET_OWNER_OF_HEAD_ENTRY(  ( ( xList * ) &xPendingReadyList ) ) ) != NULL )\r
1016                                 {\r
1017                                         vListRemove( &( pxTCB->xEventListItem ) );\r
1018                                         vListRemove( &( pxTCB->xGenericListItem ) );\r
1019                                         prvAddTaskToReadyQueue( pxTCB );\r
1020                                         \r
1021                                         /* If we have moved a task that has a priority higher than\r
1022                                         the current task then we should yield. */\r
1023                                         if( pxTCB->uxPriority >= pxCurrentTCB->uxPriority )\r
1024                                         {\r
1025                                                 xYieldRequired = pdTRUE;\r
1026                                         }\r
1027                                 }\r
1028 \r
1029                                 /* If any ticks occurred while the scheduler was suspended then\r
1030                                 they should be processed now.  This ensures the tick count does not\r
1031                                 slip, and that any delayed tasks are resumed at the correct time. */\r
1032                                 if( uxMissedTicks > ( unsigned portBASE_TYPE ) 0 )\r
1033                                 {\r
1034                                         while( uxMissedTicks > ( unsigned portBASE_TYPE ) 0 )\r
1035                                         {\r
1036                                                 vTaskIncrementTick();\r
1037                                                 --uxMissedTicks;\r
1038                                         }\r
1039 \r
1040                                         /* As we have processed some ticks it is appropriate to yield\r
1041                                         to ensure the highest priority task that is ready to run is\r
1042                                         the task actually running. */\r
1043                                         xYieldRequired = pdTRUE;\r
1044                                 }\r
1045                                 \r
1046                                 if( ( xYieldRequired == pdTRUE ) || ( xMissedYield == pdTRUE ) )\r
1047                                 {\r
1048                                         xAlreadyYielded = pdTRUE;\r
1049                                         xMissedYield = pdFALSE;\r
1050                                         taskYIELD();\r
1051                                 }\r
1052                         }\r
1053                 }\r
1054         }\r
1055         portEXIT_CRITICAL();\r
1056 \r
1057         return xAlreadyYielded;\r
1058 }\r
1059 \r
1060 \r
1061 \r
1062 \r
1063 \r
1064 \r
1065 /*-----------------------------------------------------------\r
1066  * PUBLIC TASK UTILITIES documented in task.h\r
1067  *----------------------------------------------------------*/\r
1068 \r
1069 \r
1070 \r
1071 portTickType xTaskGetTickCount( void )\r
1072 {\r
1073 portTickType xTicks;\r
1074 \r
1075         /* Critical section required if running on a 16 bit processor. */\r
1076         taskENTER_CRITICAL();\r
1077         {\r
1078                 xTicks = xTickCount;\r
1079         }\r
1080         taskEXIT_CRITICAL();\r
1081 \r
1082         return xTicks;\r
1083 }\r
1084 /*-----------------------------------------------------------*/\r
1085 \r
1086 unsigned portBASE_TYPE uxTaskGetNumberOfTasks( void )\r
1087 {\r
1088 unsigned portBASE_TYPE uxNumberOfTasks;\r
1089 \r
1090         taskENTER_CRITICAL();\r
1091                 uxNumberOfTasks = uxCurrentNumberOfTasks;\r
1092         taskEXIT_CRITICAL();\r
1093 \r
1094         return uxNumberOfTasks;\r
1095 }\r
1096 /*-----------------------------------------------------------*/\r
1097 \r
1098 #if ( ( configUSE_TRACE_FACILITY == 1 ) && ( INCLUDE_vTaskDelete == 1 ) && ( INCLUDE_vTaskSuspend == 1 ) )\r
1099 \r
1100         void vTaskList( signed portCHAR *pcWriteBuffer )\r
1101         {\r
1102         unsigned portBASE_TYPE uxQueue;\r
1103 \r
1104                 /* This is a VERY costly function that should be used for debug only.\r
1105                 It leaves interrupts disabled for a LONG time. */\r
1106 \r
1107         vTaskSuspendAll();\r
1108                 {\r
1109                         /* Run through all the lists that could potentially contain a TCB and\r
1110                         report the task name, state and stack high water mark. */\r
1111 \r
1112                         pcWriteBuffer[ 0 ] = ( signed portCHAR ) 0x00;\r
1113                         strcat( ( portCHAR * ) pcWriteBuffer, ( const portCHAR * ) "\r\n" );\r
1114 \r
1115                         uxQueue = uxTopUsedPriority + 1;\r
1116 \r
1117                         do\r
1118                         {\r
1119                                 uxQueue--;\r
1120 \r
1121                                 if( !listLIST_IS_EMPTY( &( pxReadyTasksLists[ uxQueue ] ) ) )\r
1122                                 {\r
1123                                         prvListTaskWithinSingleList( pcWriteBuffer, ( xList * ) &( pxReadyTasksLists[ uxQueue ] ), tskREADY_CHAR );                     \r
1124                                 }\r
1125                         }while( uxQueue > ( unsigned portSHORT ) tskIDLE_PRIORITY );\r
1126 \r
1127                         if( !listLIST_IS_EMPTY( pxDelayedTaskList ) )\r
1128                         {\r
1129                                 prvListTaskWithinSingleList( pcWriteBuffer, ( xList * ) pxDelayedTaskList, tskBLOCKED_CHAR );\r
1130                         }\r
1131 \r
1132                         if( !listLIST_IS_EMPTY( pxOverflowDelayedTaskList ) )\r
1133                         {\r
1134                                 prvListTaskWithinSingleList( pcWriteBuffer, ( xList * ) pxOverflowDelayedTaskList, tskBLOCKED_CHAR );\r
1135                         }\r
1136 \r
1137                         if( !listLIST_IS_EMPTY( &xTasksWaitingTermination ) )\r
1138                         {\r
1139                                 prvListTaskWithinSingleList( pcWriteBuffer, ( xList * ) &xTasksWaitingTermination, tskDELETED_CHAR );\r
1140                         }\r
1141 \r
1142                         if( !listLIST_IS_EMPTY( &xSuspendedTaskList ) )\r
1143                         {\r
1144                                 prvListTaskWithinSingleList( pcWriteBuffer, ( xList * ) &xSuspendedTaskList, tskSUSPENDED_CHAR );\r
1145                         }\r
1146                 }\r
1147         xTaskResumeAll();\r
1148         }\r
1149 \r
1150 #endif\r
1151 /*----------------------------------------------------------*/\r
1152 \r
1153 #if ( configUSE_TRACE_FACILITY == 1 )\r
1154 \r
1155         void vTaskStartTrace( signed portCHAR * pcBuffer, unsigned portLONG ulBufferSize )\r
1156         {\r
1157                 portENTER_CRITICAL();\r
1158                 {\r
1159                         pcTraceBuffer = ( volatile signed portCHAR * volatile )pcBuffer;\r
1160                         pcTraceBufferStart = pcBuffer;\r
1161                         pcTraceBufferEnd = pcBuffer + ( ulBufferSize - tskSIZE_OF_EACH_TRACE_LINE );\r
1162                         xTracing = pdTRUE;\r
1163                 }\r
1164                 portEXIT_CRITICAL();\r
1165         }\r
1166 \r
1167 #endif\r
1168 /*----------------------------------------------------------*/\r
1169 \r
1170 #if ( configUSE_TRACE_FACILITY == 1 )\r
1171 \r
1172         unsigned portLONG ulTaskEndTrace( void )\r
1173         {\r
1174         unsigned portLONG ulBufferLength;\r
1175 \r
1176                 portENTER_CRITICAL();\r
1177                         xTracing = pdFALSE;\r
1178                 portEXIT_CRITICAL();\r
1179 \r
1180                 ulBufferLength = ( unsigned portLONG ) ( pcTraceBuffer - pcTraceBufferStart );\r
1181 \r
1182                 return ulBufferLength;\r
1183         }\r
1184 \r
1185 #endif\r
1186 \r
1187 \r
1188 \r
1189 /*-----------------------------------------------------------\r
1190  * SCHEDULER INTERNALS AVAILABLE FOR PORTING PURPOSES\r
1191  * documented in task.h\r
1192  *----------------------------------------------------------*/\r
1193 \r
1194 \r
1195 inline void vTaskIncrementTick( void )\r
1196 {\r
1197         /* Called by the portable layer each time a tick interrupt occurs.\r
1198         Increments the tick then checks to see if the new tick value will cause any\r
1199         tasks to be unblocked. */\r
1200         if( uxSchedulerSuspended == ( unsigned portBASE_TYPE ) pdFALSE )\r
1201         {\r
1202                 ++xTickCount;\r
1203                 if( xTickCount == ( portTickType ) 0 )\r
1204                 {\r
1205                         xList *pxTemp;\r
1206 \r
1207                         /* Tick count has overflowed so we need to swap the delay lists.  \r
1208                         If there are any items in pxDelayedTaskList here then there is \r
1209                         an error! */\r
1210                         pxTemp = pxDelayedTaskList;\r
1211                         pxDelayedTaskList = pxOverflowDelayedTaskList;\r
1212                         pxOverflowDelayedTaskList = pxTemp;\r
1213                 }\r
1214 \r
1215                 /* See if this tick has made a timeout expire. */\r
1216                 prvCheckDelayedTasks();\r
1217         }\r
1218         else\r
1219         {\r
1220                 ++uxMissedTicks;\r
1221 \r
1222                 /* The tick hook gets called at regular intervals, even if the \r
1223                 scheduler is locked. */\r
1224                 #if ( configUSE_TICK_HOOK == 1 )\r
1225                 {\r
1226                         extern void vApplicationTickHook( void );\r
1227 \r
1228                         vApplicationTickHook();\r
1229                 }\r
1230                 #endif\r
1231         }\r
1232 \r
1233         #if ( configUSE_TICK_HOOK == 1 )\r
1234         {\r
1235                 extern void vApplicationTickHook( void );\r
1236 \r
1237                 /* Guard against the tick hook being called when the missed tick\r
1238                 count is being unwound (when the scheduler is being unlocked. */\r
1239                 if( uxMissedTicks == 0 )\r
1240                 {\r
1241                         vApplicationTickHook();\r
1242                 }\r
1243         }\r
1244         #endif\r
1245 }\r
1246 /*-----------------------------------------------------------*/\r
1247 \r
1248 #if ( ( INCLUDE_vTaskCleanUpResources == 1 ) && ( INCLUDE_vTaskSuspend == 1 ) )\r
1249 \r
1250         void vTaskCleanUpResources( void )\r
1251         {\r
1252         unsigned portSHORT usQueue;\r
1253         volatile tskTCB *pxTCB;\r
1254 \r
1255                 usQueue = ( unsigned portSHORT ) uxTopUsedPriority + ( unsigned portSHORT ) 1;\r
1256 \r
1257                 /* Remove any TCB's from the ready queues. */\r
1258                 do\r
1259                 {\r
1260                         usQueue--;\r
1261 \r
1262                         while( !listLIST_IS_EMPTY( &( pxReadyTasksLists[ usQueue ] ) ) )\r
1263                         {\r
1264                                 listGET_OWNER_OF_NEXT_ENTRY( pxTCB, &( pxReadyTasksLists[ usQueue ] ) );\r
1265                                 vListRemove( ( xListItem * ) &( pxTCB->xGenericListItem ) );\r
1266 \r
1267                                 prvDeleteTCB( ( tskTCB * ) pxTCB );\r
1268                         }\r
1269                 }while( usQueue > ( unsigned portSHORT ) tskIDLE_PRIORITY );\r
1270 \r
1271                 /* Remove any TCB's from the delayed queue. */\r
1272                 while( !listLIST_IS_EMPTY( &xDelayedTaskList1 ) )\r
1273                 {\r
1274                         listGET_OWNER_OF_NEXT_ENTRY( pxTCB, &xDelayedTaskList1 );\r
1275                         vListRemove( ( xListItem * ) &( pxTCB->xGenericListItem ) );\r
1276 \r
1277                         prvDeleteTCB( ( tskTCB * ) pxTCB );\r
1278                 }\r
1279 \r
1280                 /* Remove any TCB's from the overflow delayed queue. */\r
1281                 while( !listLIST_IS_EMPTY( &xDelayedTaskList2 ) )\r
1282                 {\r
1283                         listGET_OWNER_OF_NEXT_ENTRY( pxTCB, &xDelayedTaskList2 );\r
1284                         vListRemove( ( xListItem * ) &( pxTCB->xGenericListItem ) );\r
1285 \r
1286                         prvDeleteTCB( ( tskTCB * ) pxTCB );\r
1287                 }\r
1288 \r
1289                 while( !listLIST_IS_EMPTY( &xSuspendedTaskList ) )\r
1290                 {\r
1291                         listGET_OWNER_OF_NEXT_ENTRY( pxTCB, &xSuspendedTaskList );\r
1292                         vListRemove( ( xListItem * ) &( pxTCB->xGenericListItem ) );\r
1293 \r
1294                         prvDeleteTCB( ( tskTCB * ) pxTCB );\r
1295                 }               \r
1296 \r
1297                 while( !listLIST_IS_EMPTY( &xPendingReadyList ) )\r
1298                 {\r
1299                         listGET_OWNER_OF_NEXT_ENTRY( pxTCB, &xPendingReadyList );\r
1300                         vListRemove( ( xListItem * ) &( pxTCB->xGenericListItem ) );\r
1301 \r
1302                         prvDeleteTCB( ( tskTCB * ) pxTCB );\r
1303                 }               \r
1304         }\r
1305 \r
1306 #endif\r
1307 /*-----------------------------------------------------------*/\r
1308 \r
1309 void vTaskSwitchContext( void )\r
1310 {\r
1311         if( uxSchedulerSuspended != ( unsigned portBASE_TYPE ) pdFALSE )\r
1312         {\r
1313                 /* The scheduler is currently suspended - do not allow a context\r
1314                 switch. */\r
1315                 xMissedYield = pdTRUE;\r
1316                 return;\r
1317         }\r
1318 \r
1319         /* Find the highest priority queue that contains ready tasks. */\r
1320         while( listLIST_IS_EMPTY( &( pxReadyTasksLists[ uxTopReadyPriority ] ) ) )\r
1321         {\r
1322                 --uxTopReadyPriority;\r
1323         }\r
1324 \r
1325         /* listGET_OWNER_OF_NEXT_ENTRY walks through the list, so the tasks of the\r
1326         same priority get an equal share of the processor time. */\r
1327         listGET_OWNER_OF_NEXT_ENTRY( pxCurrentTCB, &( pxReadyTasksLists[ uxTopReadyPriority ] ) );\r
1328         vWriteTraceToBuffer();\r
1329 }\r
1330 /*-----------------------------------------------------------*/\r
1331 \r
1332 void vTaskPlaceOnEventList( xList *pxEventList, portTickType xTicksToWait )\r
1333 {\r
1334 portTickType xTimeToWake;\r
1335 \r
1336         /* THIS FUNCTION MUST BE CALLED WITH INTERRUPTS DISABLED OR THE\r
1337         SCHEDULER SUSPENDED. */\r
1338 \r
1339         /* Place the event list item of the TCB in the appropriate event list.\r
1340         This is placed in the list in priority order so the highest priority task\r
1341         is the first to be woken by the event. */\r
1342         vListInsert( ( xList * ) pxEventList, ( xListItem * ) &( pxCurrentTCB->xEventListItem ) );\r
1343 \r
1344         /* Calculate the time at which the task should be woken if the event does\r
1345         not occur.  This may overflow but this doesn't matter. */\r
1346         xTimeToWake = xTickCount + xTicksToWait;\r
1347 \r
1348         /* We must remove ourselves from the ready list before adding ourselves\r
1349         to the blocked list as the same list item is used for both lists.  We have\r
1350         exclusive access to the ready lists as the scheduler is locked. */\r
1351         vListRemove( ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );\r
1352 \r
1353         listSET_LIST_ITEM_VALUE( &( pxCurrentTCB->xGenericListItem ), xTimeToWake );\r
1354 \r
1355         if( xTimeToWake < xTickCount )\r
1356         {\r
1357                 /* Wake time has overflowed.  Place this item in the overflow list. */\r
1358                 vListInsert( ( xList * ) pxOverflowDelayedTaskList, ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );\r
1359         }\r
1360         else\r
1361         {\r
1362                 /* The wake time has not overflowed, so we can use the current block list. */\r
1363                 vListInsert( ( xList * ) pxDelayedTaskList, ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );\r
1364         }\r
1365 }\r
1366 /*-----------------------------------------------------------*/\r
1367 \r
1368 signed portBASE_TYPE xTaskRemoveFromEventList( const xList *pxEventList )\r
1369 {\r
1370 tskTCB *pxUnblockedTCB;\r
1371 portBASE_TYPE xReturn;\r
1372 \r
1373         /* THIS FUNCTION MUST BE CALLED WITH INTERRUPTS DISABLED OR THE\r
1374         SCHEDULER SUSPENDED.  It can also be called from within an ISR. */\r
1375 \r
1376         /* The event list is sorted in priority order, so we can remove the\r
1377         first in the list, remove the TCB from the delayed list, and add\r
1378         it to the ready list.\r
1379         \r
1380         If an event is for a queue that is locked then this function will never\r
1381         get called - the lock count on the queue will get modified instead.  This\r
1382         means we can always expect exclusive access to the event list here. */\r
1383         pxUnblockedTCB = ( tskTCB * ) listGET_OWNER_OF_HEAD_ENTRY( pxEventList );\r
1384         vListRemove( &( pxUnblockedTCB->xEventListItem ) );\r
1385 \r
1386         if( uxSchedulerSuspended == ( unsigned portBASE_TYPE ) pdFALSE )\r
1387         {\r
1388                 vListRemove( &( pxUnblockedTCB->xGenericListItem ) );\r
1389                 prvAddTaskToReadyQueue( pxUnblockedTCB );\r
1390         }\r
1391         else\r
1392         {\r
1393                 /* We cannot access the delayed or ready lists, so will hold this\r
1394                 task pending until the scheduler is resumed. */\r
1395                 vListInsertEnd( ( xList * ) &( xPendingReadyList ), &( pxUnblockedTCB->xEventListItem ) );\r
1396         }\r
1397 \r
1398         if( pxUnblockedTCB->uxPriority >= pxCurrentTCB->uxPriority )\r
1399         {\r
1400                 /* Return true if the task removed from the event list has\r
1401                 a higher priority than the calling task.  This allows\r
1402                 the calling task to know if it should force a context\r
1403                 switch now. */\r
1404                 xReturn = pdTRUE;\r
1405         }\r
1406         else\r
1407         {\r
1408                 xReturn = pdFALSE;\r
1409         }\r
1410 \r
1411         return xReturn;\r
1412 }\r
1413 \r
1414 \r
1415 \r
1416 \r
1417 \r
1418 /*\r
1419  * -----------------------------------------------------------\r
1420  * The Idle task.\r
1421  * ----------------------------------------------------------\r
1422  *\r
1423  * The portTASK_FUNCTION() macro is used to allow port/compiler specific\r
1424  * language extensions.  The equivalent prototype for this function is:\r
1425  *\r
1426  * void prvIdleTask( void *pvParameters );\r
1427  *\r
1428  */\r
1429 static portTASK_FUNCTION( prvIdleTask, pvParameters )\r
1430 {\r
1431         /* Stop warnings. */\r
1432         ( void ) pvParameters;\r
1433 \r
1434         for( ;; )\r
1435         {\r
1436                 /* See if any tasks have been deleted. */\r
1437                 prvCheckTasksWaitingTermination();\r
1438 \r
1439                 #if ( configUSE_PREEMPTION == 0 )\r
1440                 {\r
1441                         /* If we are not using preemption we keep forcing a task switch to\r
1442                         see if any other task has become available.  If we are using\r
1443                         preemption we don't need to do this as any task becoming available\r
1444                         will automatically get the processor anyway. */\r
1445                         taskYIELD();    \r
1446                 }\r
1447                 #endif\r
1448 \r
1449                 #if ( ( configUSE_PREEMPTION == 1 ) && ( configIDLE_SHOULD_YIELD == 1 ) )\r
1450                 {\r
1451                         /* When using preemption tasks of equal priority will be\r
1452                         timesliced.  If a task that is sharing the idle priority is ready\r
1453                         to run then the idle task should yield before the end of the\r
1454                         timeslice.\r
1455                         \r
1456                         A critical region is not required here as we are just reading from\r
1457                         the list, and an occasional incorrect value will not matter.  If\r
1458                         the ready list at the idle priority contains more than one task\r
1459                         then a task other than the idle task is ready to execute. */\r
1460                         if( listCURRENT_LIST_LENGTH( &( pxReadyTasksLists[ tskIDLE_PRIORITY ] ) ) > ( unsigned portBASE_TYPE ) 1 )\r
1461                         {\r
1462                                 taskYIELD();\r
1463                         }\r
1464                 }\r
1465                 #endif\r
1466 \r
1467                 #if ( configUSE_IDLE_HOOK == 1 )\r
1468                 {\r
1469                         extern void vApplicationIdleHook( void );\r
1470 \r
1471                         /* Call the user defined function from within the idle task.  This\r
1472                         allows the application designer to add background functionality\r
1473                         without the overhead of a separate task.\r
1474                         NOTE: vApplicationIdleHook() MUST NOT, UNDER ANY CIRCUMSTANCES,\r
1475                         CALL A FUNCTION THAT MIGHT BLOCK. */\r
1476                         vApplicationIdleHook();\r
1477                 }\r
1478                 #endif\r
1479         }\r
1480 } /*lint !e715 pvParameters is not accessed but all task functions require the same prototype. */\r
1481 \r
1482 \r
1483 \r
1484 \r
1485 \r
1486 \r
1487 \r
1488 /*-----------------------------------------------------------\r
1489  * File private functions documented at the top of the file.\r
1490  *----------------------------------------------------------*/\r
1491 \r
1492 \r
1493 \r
1494 static void prvInitialiseTCBVariables( tskTCB *pxTCB, unsigned portSHORT usStackDepth, const signed portCHAR * const pcName, unsigned portBASE_TYPE uxPriority )\r
1495 {\r
1496         pxTCB->usStackDepth = usStackDepth;\r
1497 \r
1498         /* Store the function name in the TCB. */\r
1499         strncpy( ( char * ) pxTCB->pcTaskName, ( const char * ) pcName, ( unsigned portSHORT ) configMAX_TASK_NAME_LEN );\r
1500         pxTCB->pcTaskName[ ( unsigned portSHORT ) configMAX_TASK_NAME_LEN - ( unsigned portSHORT ) 1 ] = '\0';\r
1501 \r
1502         /* This is used as an array index so must ensure it's not too large. */\r
1503         if( uxPriority >= configMAX_PRIORITIES )\r
1504         {\r
1505                 uxPriority = configMAX_PRIORITIES - 1;\r
1506         }\r
1507 \r
1508         pxTCB->uxPriority = uxPriority;\r
1509 \r
1510         vListInitialiseItem( &( pxTCB->xGenericListItem ) );\r
1511         vListInitialiseItem( &( pxTCB->xEventListItem ) );\r
1512 \r
1513         /* Set the pxTCB as a link back from the xListItem.  This is so we can get\r
1514         back to the containing TCB from a generic item in a list. */\r
1515         listSET_LIST_ITEM_OWNER( &( pxTCB->xGenericListItem ), pxTCB );\r
1516 \r
1517         /* Event lists are always in priority order. */\r
1518         listSET_LIST_ITEM_VALUE( &( pxTCB->xEventListItem ), configMAX_PRIORITIES - ( portTickType ) uxPriority );\r
1519         listSET_LIST_ITEM_OWNER( &( pxTCB->xEventListItem ), pxTCB );\r
1520 }\r
1521 /*-----------------------------------------------------------*/\r
1522 \r
1523 static void prvInitialiseTaskLists( void )\r
1524 {\r
1525 unsigned portBASE_TYPE uxPriority;\r
1526 \r
1527         for( uxPriority = 0; uxPriority < configMAX_PRIORITIES; uxPriority++ )\r
1528         {\r
1529                 vListInitialise( ( xList * ) &( pxReadyTasksLists[ uxPriority ] ) );\r
1530         }\r
1531 \r
1532         vListInitialise( ( xList * ) &xDelayedTaskList1 );\r
1533         vListInitialise( ( xList * ) &xDelayedTaskList2 );\r
1534         vListInitialise( ( xList * ) &xPendingReadyList );\r
1535 \r
1536         #if ( INCLUDE_vTaskDelete == 1 )\r
1537         {\r
1538                 vListInitialise( ( xList * ) &xTasksWaitingTermination );\r
1539         }\r
1540         #endif\r
1541 \r
1542         #if ( INCLUDE_vTaskSuspend == 1 )\r
1543         {\r
1544                 vListInitialise( ( xList * ) &xSuspendedTaskList );\r
1545         }\r
1546         #endif\r
1547 \r
1548         /* Start with pxDelayedTaskList using list1 and the pxOverflowDelayedTaskList\r
1549         using list2. */\r
1550         pxDelayedTaskList = &xDelayedTaskList1;\r
1551         pxOverflowDelayedTaskList = &xDelayedTaskList2;\r
1552 }\r
1553 /*-----------------------------------------------------------*/\r
1554 \r
1555 static void prvCheckTasksWaitingTermination( void )\r
1556 {                                                       \r
1557         #if ( INCLUDE_vTaskDelete == 1 )\r
1558         {                               \r
1559                 portBASE_TYPE xListIsEmpty;\r
1560 \r
1561                 /* ucTasksDeleted is used to prevent vTaskSuspendAll() being called\r
1562                 too often in the idle task. */\r
1563                 if( uxTasksDeleted > ( unsigned portBASE_TYPE ) 0 )\r
1564                 {\r
1565                         vTaskSuspendAll();\r
1566                                 xListIsEmpty = listLIST_IS_EMPTY( &xTasksWaitingTermination );                          \r
1567                         xTaskResumeAll();\r
1568 \r
1569                         if( !xListIsEmpty )\r
1570                         {\r
1571                                 tskTCB *pxTCB;\r
1572 \r
1573                                 portENTER_CRITICAL();\r
1574                                 {                       \r
1575                                         pxTCB = ( tskTCB * ) listGET_OWNER_OF_HEAD_ENTRY( ( ( xList * ) &xTasksWaitingTermination ) );\r
1576                                         vListRemove( &( pxTCB->xGenericListItem ) );\r
1577                                         --uxCurrentNumberOfTasks;\r
1578                                         --uxTasksDeleted;\r
1579                                 }\r
1580                                 portEXIT_CRITICAL();\r
1581 \r
1582                                 prvDeleteTCB( pxTCB );\r
1583                         }\r
1584                 }\r
1585         }\r
1586         #endif\r
1587 }\r
1588 /*-----------------------------------------------------------*/\r
1589 \r
1590 static tskTCB *prvAllocateTCBAndStack( unsigned portSHORT usStackDepth )\r
1591 {\r
1592 tskTCB *pxNewTCB;\r
1593 \r
1594         /* Allocate space for the TCB.  Where the memory comes from depends on\r
1595         the implementation of the port malloc function. */\r
1596         pxNewTCB = ( tskTCB * ) pvPortMalloc( sizeof( tskTCB ) );\r
1597 \r
1598         if( pxNewTCB != NULL )\r
1599         {\r
1600                 /* Allocate space for the stack used by the task being created.\r
1601                 The base of the stack memory stored in the TCB so the task can\r
1602                 be deleted later if required. */\r
1603                 pxNewTCB->pxStack = ( portSTACK_TYPE * ) pvPortMalloc( ( ( size_t )usStackDepth ) * sizeof( portSTACK_TYPE ) );\r
1604 \r
1605                 if( pxNewTCB->pxStack == NULL )\r
1606                 {\r
1607                         /* Could not allocate the stack.  Delete the allocated TCB. */\r
1608                         vPortFree( pxNewTCB );                  \r
1609                         pxNewTCB = NULL;                        \r
1610                 }               \r
1611                 else\r
1612                 {\r
1613                         /* Just to help debugging. */\r
1614                         memset( pxNewTCB->pxStack, tskSTACK_FILL_BYTE, usStackDepth * sizeof( portSTACK_TYPE ) );\r
1615                 }\r
1616         }\r
1617 \r
1618         return pxNewTCB;\r
1619 }\r
1620 /*-----------------------------------------------------------*/\r
1621 \r
1622 #if ( configUSE_TRACE_FACILITY == 1 )\r
1623 \r
1624         static void prvListTaskWithinSingleList( signed portCHAR *pcWriteBuffer, xList *pxList, signed portCHAR cStatus )\r
1625         {\r
1626         volatile tskTCB *pxNextTCB, *pxFirstTCB;\r
1627         static portCHAR pcStatusString[ 50 ];\r
1628         unsigned portSHORT usStackRemaining;\r
1629 \r
1630                 /* Write the details of all the TCB's in pxList into the buffer. */\r
1631                 listGET_OWNER_OF_NEXT_ENTRY( pxFirstTCB, pxList );\r
1632                 do\r
1633                 {\r
1634                         listGET_OWNER_OF_NEXT_ENTRY( pxNextTCB, pxList );\r
1635                         usStackRemaining = usTaskCheckFreeStackSpace( ( unsigned portCHAR * ) pxNextTCB->pxStack );\r
1636                         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
1637                         strcat( ( portCHAR * ) pcWriteBuffer, ( portCHAR * ) pcStatusString );\r
1638 \r
1639                 } while( pxNextTCB != pxFirstTCB );\r
1640         }\r
1641 \r
1642 #endif\r
1643 /*-----------------------------------------------------------*/\r
1644 \r
1645 #if ( configUSE_TRACE_FACILITY == 1 )\r
1646         unsigned portSHORT usTaskCheckFreeStackSpace( const unsigned portCHAR *pucStackByte )\r
1647         {\r
1648         register unsigned portSHORT usCount = 0;\r
1649 \r
1650                 while( *pucStackByte == tskSTACK_FILL_BYTE )\r
1651                 {\r
1652                         pucStackByte -= portSTACK_GROWTH;\r
1653                         usCount++;\r
1654                 }\r
1655 \r
1656                 usCount /= sizeof( portSTACK_TYPE );\r
1657 \r
1658                 return usCount;\r
1659         }\r
1660 #endif\r
1661 /*-----------------------------------------------------------*/\r
1662 \r
1663 \r
1664 \r
1665 #if ( ( INCLUDE_vTaskDelete == 1 ) || ( INCLUDE_vTaskCleanUpResources == 1 ) )\r
1666 \r
1667         static void prvDeleteTCB( tskTCB *pxTCB )\r
1668         {\r
1669                 /* Free up the memory allocated by the scheduler for the task.  It is up to\r
1670                 the task to free any memory allocated at the application level. */\r
1671                 vPortFree( pxTCB->pxStack );\r
1672                 vPortFree( pxTCB );\r
1673         }\r
1674 \r
1675 #endif\r
1676 \r
1677 \r
1678 /*-----------------------------------------------------------*/\r
1679 \r
1680 #if ( INCLUDE_xTaskGetCurrentTaskHandle == 1 )\r
1681 \r
1682         xTaskHandle xTaskGetCurrentTaskHandle( void )\r
1683         {\r
1684         xTaskHandle xReturn;\r
1685 \r
1686                 portENTER_CRITICAL();\r
1687                 {\r
1688                         xReturn = ( xTaskHandle ) pxCurrentTCB;\r
1689                 }\r
1690                 portEXIT_CRITICAL();\r
1691 \r
1692                 return xReturn;\r
1693         }\r
1694 \r
1695 #endif\r
1696 \r
1697 \r
1698 \r
1699 \r
1700 \r