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

   1 /*\r
   2         FreeRTOS.org V4.0.4 - 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           interrupts 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 Changes from V4.0.3\r
 164 \r
 165         + Extra checks have been placed in vTaskPrioritySet() to avoid unnecessary\r
 166           yields.\r
 167 \r
 168 Changed from V4.0.4\r
 169 \r
 170         + Bug fix:  The 'value' of the event list item is updated when the priority\r
 171           of a task is changed.  Previously only the priority of the TCB itself was\r
 172           changed.\r
 173         + When resuming a task a check is first made to see if the task is actually\r
 174           suspended.\r
 175         + vTaskPrioritySet() and vTaskResume() no longer use the event list item.\r
 176           This has not been necessary since V4.0.1 when the xMissedYield handling\r
 177           was added.\r
 178         + Implement xTaskResumeFromISR().\r
 179 */\r
 180 \r
 181 #include <stdio.h>\r
 182 #include <stdlib.h>\r
 183 #include <string.h>\r
 184 \r
 185 #include "FreeRTOS.h"\r
 186 #include "task.h"\r
 187 \r
 188 /*\r
 189  * Macro to define the amount of stack available to the idle task.\r
 190  */\r
 191 #define tskIDLE_STACK_SIZE      configMINIMAL_STACK_SIZE\r
 192 \r
 193 \r
 194 /*\r
 195  * Default a definitions for backwards compatibility with old\r
 196  * portmacro.h files.\r
 197  */\r
 198 #ifndef configMAX_TASK_NAME_LEN\r
 199         #define configMAX_TASK_NAME_LEN 16\r
 200 #endif\r
 201 \r
 202 #ifndef INCLUDE_xTaskGetCurrentTaskHandle\r
 203         #define INCLUDE_xTaskGetCurrentTaskHandle 0\r
 204 #endif\r
 205 \r
 206 #ifndef configIDLE_SHOULD_YIELD\r
 207         #define configIDLE_SHOULD_YIELD         1\r
 208 #endif\r
 209 \r
 210 #if configMAX_TASK_NAME_LEN < 1\r
 211         #undef configMAX_TASK_NAME_LEN\r
 212         #define configMAX_TASK_NAME_LEN 1\r
 213 #endif\r
 214 \r
 215 #ifndef INCLUDE_xTaskResumeFromISR\r
 216         #define INCLUDE_xTaskResumeFromISR 1\r
 217 #endif \r
 218 \r
 219 /*\r
 220  * Task control block.  A task control block (TCB) is allocated to each task,\r
 221  * and stores the context of the task.\r
 222  */\r
 223 typedef struct tskTaskControlBlock\r
 224 {\r
 225         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
 226         xListItem                               xGenericListItem;       /*< List item used to place the TCB in ready and blocked queues. */\r
 227         xListItem                               xEventListItem;         /*< List item used to place the TCB in event lists. */\r
 228         unsigned portBASE_TYPE  uxPriority;                     /*< The priority of the task where 0 is the lowest priority. */\r
 229         portSTACK_TYPE                  *pxStack;                       /*< Points to the start of the stack. */\r
 230         unsigned portBASE_TYPE  uxTCBNumber;            /*< This is used for tracing the scheduler and making debugging easier only. */\r
 231         signed portCHAR                 pcTaskName[ configMAX_TASK_NAME_LEN ];/*< Descriptive name given to the task when created.  Facilitates debugging only. */\r
 232         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
 233 } tskTCB;\r
 234 \r
 235 /*lint -e956 */\r
 236 \r
 237 tskTCB * volatile pxCurrentTCB = NULL;                                  \r
 238 \r
 239 /* Lists for ready and blocked tasks. --------------------*/\r
 240 \r
 241 static xList pxReadyTasksLists[ configMAX_PRIORITIES ]; /*< Prioritised ready tasks. */\r
 242 static xList xDelayedTaskList1;                                                 /*< Delayed tasks. */\r
 243 static xList xDelayedTaskList2;                                                 /*< Delayed tasks (two lists are used - one for delays that have overflowed the current tick count. */\r
 244 static xList * volatile pxDelayedTaskList;                              /*< Points to the delayed task list currently being used. */\r
 245 static xList * volatile pxOverflowDelayedTaskList;              /*< Points to the delayed task list currently being used to hold tasks that have overflowed the current tick count. */\r
 246 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
 247 \r
 248 #if ( INCLUDE_vTaskDelete == 1 )\r
 249 \r
 250         static volatile xList xTasksWaitingTermination;         /*< Tasks that have been deleted - but the their memory not yet freed. */\r
 251         static volatile unsigned portBASE_TYPE uxTasksDeleted = ( unsigned portBASE_TYPE ) 0;\r
 252 \r
 253 #endif\r
 254 \r
 255 #if ( INCLUDE_vTaskSuspend == 1 )\r
 256 \r
 257         static xList xSuspendedTaskList;                                        /*< Tasks that are currently suspended. */\r
 258 \r
 259 #endif\r
 260 \r
 261 /* File private variables. --------------------------------*/\r
 262 static volatile unsigned portBASE_TYPE uxCurrentNumberOfTasks   = ( unsigned portBASE_TYPE ) 0;\r
 263 static volatile portTickType xTickCount                                                 = ( portTickType ) 0;\r
 264 static unsigned portBASE_TYPE uxTopUsedPriority                         = tskIDLE_PRIORITY;\r
 265 static volatile unsigned portBASE_TYPE uxTopReadyPriority               = tskIDLE_PRIORITY;\r
 266 static volatile signed portBASE_TYPE xSchedulerRunning                  = pdFALSE;\r
 267 static volatile unsigned portBASE_TYPE uxSchedulerSuspended             = ( unsigned portBASE_TYPE ) pdFALSE;\r
 268 static volatile unsigned portBASE_TYPE uxMissedTicks                    = ( unsigned portBASE_TYPE ) 0;\r
 269 static volatile portBASE_TYPE xMissedYield                                              = ( portBASE_TYPE ) pdFALSE;\r
 270 \r
 271 /* Debugging and trace facilities private variables and macros. ------------*/\r
 272 \r
 273 /*\r
 274  * The value used to fill the stack of a task when the task is created.  This\r
 275  * is used purely for checking the high water mark for tasks.\r
 276  */\r
 277 #define tskSTACK_FILL_BYTE      ( 0xa5 )\r
 278 \r
 279 /*\r
 280  * Macros used by vListTask to indicate which state a task is in.\r
 281  */\r
 282 #define tskBLOCKED_CHAR         ( ( signed portCHAR ) 'B' )\r
 283 #define tskREADY_CHAR           ( ( signed portCHAR ) 'R' )\r
 284 #define tskDELETED_CHAR         ( ( signed portCHAR ) 'D' )\r
 285 #define tskSUSPENDED_CHAR       ( ( signed portCHAR ) 'S' )\r
 286 \r
 287 /*\r
 288  * Macros and private variables used by the trace facility.\r
 289  */\r
 290 #if ( configUSE_TRACE_FACILITY == 1 )\r
 291 \r
 292         #define tskSIZE_OF_EACH_TRACE_LINE                      ( ( unsigned portLONG ) ( sizeof( unsigned portLONG ) + sizeof( unsigned portLONG ) ) )\r
 293         static volatile signed portCHAR * volatile pcTraceBuffer;\r
 294         static signed portCHAR *pcTraceBufferStart;\r
 295         static signed portCHAR *pcTraceBufferEnd;\r
 296         static signed portBASE_TYPE xTracing = pdFALSE;\r
 297 \r
 298 #endif\r
 299 \r
 300 /*\r
 301  * Macro that writes a trace of scheduler activity to a buffer.  This trace\r
 302  * shows which task is running when and is very useful as a debugging tool.\r
 303  * As this macro is called each context switch it is a good idea to undefine\r
 304  * it if not using the facility.\r
 305  */\r
 306 #if ( configUSE_TRACE_FACILITY == 1 )\r
 307 \r
 308         #define vWriteTraceToBuffer()                                                                                                                                   \\r
 309         {                                                                                                                                                                                               \\r
 310                 if( xTracing )                                                                                                                                                          \\r
 311                 {                                                                                                                                                                                       \\r
 312                         static unsigned portBASE_TYPE uxPreviousTask = 255;                                                                             \\r
 313                                                                                                                                                                                                         \\r
 314                         if( uxPreviousTask != pxCurrentTCB->uxTCBNumber )                                                                               \\r
 315                         {                                                                                                                                                                               \\r
 316                                 if( ( pcTraceBuffer + tskSIZE_OF_EACH_TRACE_LINE ) < pcTraceBufferEnd )                         \\r
 317                                 {                                                                                                                                                                       \\r
 318                                         uxPreviousTask = pxCurrentTCB->uxTCBNumber;                                                                             \\r
 319                                         *( unsigned portLONG * ) pcTraceBuffer = ( unsigned portLONG ) xTickCount;              \\r
 320                                         pcTraceBuffer += sizeof( unsigned portLONG );                                                                   \\r
 321                                         *( unsigned portLONG * ) pcTraceBuffer = ( unsigned portLONG ) uxPreviousTask;  \\r
 322                                         pcTraceBuffer += sizeof( unsigned portLONG );                                                                   \\r
 323                                 }                                                                                                                                                                       \\r
 324                                 else                                                                                                                                                            \\r
 325                                 {                                                                                                                                                                       \\r
 326                                         xTracing = pdFALSE;                                                                                                                             \\r
 327                                 }                                                                                                                                                                       \\r
 328                         }                                                                                                                                                                               \\r
 329                 }                                                                                                                                                                                       \\r
 330         }\r
 331 \r
 332 #else\r
 333 \r
 334         #define vWriteTraceToBuffer()\r
 335 \r
 336 #endif\r
 337 \r
 338 \r
 339 /*\r
 340  * Place the task represented by pxTCB into the appropriate ready queue for\r
 341  * the task.  It is inserted at the end of the list.  One quirk of this is\r
 342  * that if the task being inserted is at the same priority as the currently\r
 343  * executing task, then it will only be rescheduled after the currently\r
 344  * executing task has been rescheduled.\r
 345  */\r
 346 #define prvAddTaskToReadyQueue( pxTCB )                                                                                                                                                 \\r
 347 {                                                                                                                                                                                                                               \\r
 348         if( pxTCB->uxPriority > uxTopReadyPriority )                                                                                                                            \\r
 349         {                                                                                                                                                                                                                       \\r
 350                 uxTopReadyPriority = pxTCB->uxPriority;                                                                                                                                 \\r
 351         }                                                                                                                                                                                                                       \\r
 352         vListInsertEnd( ( xList * ) &( pxReadyTasksLists[ pxTCB->uxPriority ] ), &( pxTCB->xGenericListItem ) );        \\r
 353 }               \r
 354 \r
 355 /*\r
 356  * Macro that looks at the list of tasks that are currently delayed to see if\r
 357  * any require waking.\r
 358  *\r
 359  * Tasks are stored in the queue in the order of their wake time - meaning\r
 360  * once one tasks has been found whose timer has not expired we need not look\r
 361  * any further down the list.\r
 362  */\r
 363 #define prvCheckDelayedTasks()                                                                                                                                                                          \\r
 364 {                                                                                                                                                                                                                                       \\r
 365 register tskTCB *pxTCB;                                                                                                                                                                                         \\r
 366                                                                                                                                                                                                                                         \\r
 367         while( ( pxTCB = ( tskTCB * ) listGET_OWNER_OF_HEAD_ENTRY( pxDelayedTaskList ) ) != NULL )                                              \\r
 368         {                                                                                                                                                                                                                               \\r
 369                 if( xTickCount < listGET_LIST_ITEM_VALUE( &( pxTCB->xGenericListItem ) ) )                                                                      \\r
 370                 {                                                                                                                                                                                                                       \\r
 371                         break;                                                                                                                                                                                                  \\r
 372                 }                                                                                                                                                                                                                       \\r
 373                 vListRemove( &( pxTCB->xGenericListItem ) );                                                                                                                            \\r
 374                 /* Is the task waiting on an event also? */                                                                                                                                     \\r
 375                 if( pxTCB->xEventListItem.pvContainer )                                                                                                                                         \\r
 376                 {                                                                                                                                                                                                                       \\r
 377                         vListRemove( &( pxTCB->xEventListItem ) );                                                                                                                              \\r
 378                 }                                                                                                                                                                                                                       \\r
 379                 prvAddTaskToReadyQueue( pxTCB );                                                                                                                \\r
 380         }                                                                                                                                                                                                                               \\r
 381 }                                                                                                                                                                                       \r
 382 \r
 383 /*\r
 384  * Several functions take an xTaskHandle parameter that can optionally be NULL,\r
 385  * where NULL is used to indicate that the handle of the currently executing\r
 386  * task should be used in place of the parameter.  This macro simply checks to\r
 387  * see if the parameter is NULL and returns a pointer to the appropriate TCB.\r
 388  */\r
 389 #define prvGetTCBFromHandle( pxHandle ) ( ( pxHandle == NULL ) ? ( tskTCB * ) pxCurrentTCB : ( tskTCB * ) pxHandle )\r
 390 \r
 391 \r
 392 /* File private functions. --------------------------------*/\r
 393 \r
 394 /*\r
 395  * Utility to ready a TCB for a given task.  Mainly just copies the parameters\r
 396  * into the TCB structure.\r
 397  */\r
 398 static void prvInitialiseTCBVariables( tskTCB *pxTCB, unsigned portSHORT usStackDepth, const signed portCHAR * const pcName, unsigned portBASE_TYPE uxPriority );\r
 399 \r
 400 /*\r
 401  * Utility to ready all the lists used by the scheduler.  This is called\r
 402  * automatically upon the creation of the first task.\r
 403  */\r
 404 static void prvInitialiseTaskLists( void );\r
 405 \r
 406 /*\r
 407  * The idle task, which as all tasks is implemented as a never ending loop.\r
 408  * The idle task is automatically created and added to the ready lists upon\r
 409  * creation of the first user task.\r
 410  *\r
 411  * The portTASK_FUNCTION_PROTO() macro is used to allow port/compiler specific\r
 412  * language extensions.  The equivalent prototype for this function is:\r
 413  *\r
 414  * void prvIdleTask( void *pvParameters );\r
 415  *\r
 416  */\r
 417 static portTASK_FUNCTION_PROTO( prvIdleTask, pvParameters );\r
 418 \r
 419 /*\r
 420  * Utility to free all memory allocated by the scheduler to hold a TCB,\r
 421  * including the stack pointed to by the TCB.\r
 422  *\r
 423  * This does not free memory allocated by the task itself (i.e. memory\r
 424  * allocated by calls to pvPortMalloc from within the tasks application code).\r
 425  */\r
 426 #if ( ( INCLUDE_vTaskDelete == 1 ) || ( INCLUDE_vTaskCleanUpResources == 1 ) )\r
 427         static void prvDeleteTCB( tskTCB *pxTCB );\r
 428 #endif\r
 429 \r
 430 /*\r
 431  * Used only by the idle task.  This checks to see if anything has been placed\r
 432  * in the list of tasks waiting to be deleted.  If so the task is cleaned up\r
 433  * and its TCB deleted.\r
 434  */\r
 435 static void prvCheckTasksWaitingTermination( void );\r
 436 \r
 437 /*\r
 438  * Allocates memory from the heap for a TCB and associated stack.  Checks the\r
 439  * allocation was successful.\r
 440  */\r
 441 static tskTCB *prvAllocateTCBAndStack( unsigned portSHORT usStackDepth );\r
 442 \r
 443 /*\r
 444  * Called from vTaskList.  vListTasks details all the tasks currently under\r
 445  * control of the scheduler.  The tasks may be in one of a number of lists.\r
 446  * prvListTaskWithinSingleList accepts a list and details the tasks from\r
 447  * within just that list.\r
 448  *\r
 449  * THIS FUNCTION IS INTENDED FOR DEBUGGING ONLY, AND SHOULD NOT BE CALLED FROM\r
 450  * NORMAL APPLICATION CODE.\r
 451  */\r
 452 #if ( configUSE_TRACE_FACILITY == 1 )\r
 453 \r
 454         static void prvListTaskWithinSingleList( signed portCHAR *pcWriteBuffer, xList *pxList, signed portCHAR cStatus );\r
 455 \r
 456 #endif\r
 457 \r
 458 /*\r
 459  * When a task is created, the stack of the task is filled with a known value.\r
 460  * This function determines the 'high water mark' of the task stack by\r
 461  * determining how much of the stack remains at the original preset value.\r
 462  */\r
 463 #if ( configUSE_TRACE_FACILITY == 1 )\r
 464 \r
 465         unsigned portSHORT usTaskCheckFreeStackSpace( const unsigned portCHAR *pucStackByte );\r
 466 \r
 467 #endif\r
 468 \r
 469 /*lint +e956 */\r
 470 \r
 471 \r
 472 \r
 473 \r
 474 \r
 475 /*-----------------------------------------------------------\r
 476  * TASK CREATION API documented in task.h\r
 477  *----------------------------------------------------------*/\r
 478 \r
 479 signed portBASE_TYPE xTaskCreate( pdTASK_CODE pvTaskCode, const signed portCHAR * const pcName, unsigned portSHORT usStackDepth, void *pvParameters, unsigned portBASE_TYPE uxPriority, xTaskHandle *pxCreatedTask )\r
 480 {\r
 481 signed portBASE_TYPE xReturn;\r
 482 tskTCB * pxNewTCB;\r
 483 static unsigned portBASE_TYPE uxTaskNumber = 0; /*lint !e956 Static is deliberate - this is guarded before use. */\r
 484 \r
 485         /* Allocate the memory required by the TCB and stack for the new task.\r
 486         checking that the allocation was successful. */\r
 487         pxNewTCB = prvAllocateTCBAndStack( usStackDepth );\r
 488 \r
 489         if( pxNewTCB != NULL )\r
 490         {               \r
 491                 portSTACK_TYPE *pxTopOfStack;\r
 492 \r
 493                 /* Setup the newly allocated TCB with the initial state of the task. */\r
 494                 prvInitialiseTCBVariables( pxNewTCB, usStackDepth, pcName, uxPriority );\r
 495 \r
 496                 /* Calculate the top of stack address.  This depends on whether the\r
 497                 stack grows from high memory to low (as per the 80x86) or visa versa.\r
 498                 portSTACK_GROWTH is used to make the result positive or negative as\r
 499                 required by the port. */\r
 500                 #if portSTACK_GROWTH < 0\r
 501                 {\r
 502                         pxTopOfStack = pxNewTCB->pxStack + ( pxNewTCB->usStackDepth - 1 );\r
 503                 }\r
 504                 #else\r
 505                 {\r
 506                         pxTopOfStack = pxNewTCB->pxStack;       \r
 507                 }\r
 508                 #endif\r
 509 \r
 510                 /* Initialize the TCB stack to look as if the task was already running,\r
 511                 but had been interrupted by the scheduler.  The return address is set\r
 512                 to the start of the task function. Once the stack has been initialised\r
 513                 the     top of stack variable is updated. */\r
 514                 pxNewTCB->pxTopOfStack = pxPortInitialiseStack( pxTopOfStack, pvTaskCode, pvParameters );\r
 515 \r
 516                 /* We are going to manipulate the task queues to add this task to a\r
 517                 ready list, so must make sure no interrupts occur. */\r
 518                 portENTER_CRITICAL();\r
 519                 {\r
 520                         uxCurrentNumberOfTasks++;\r
 521                         if( uxCurrentNumberOfTasks == ( unsigned portBASE_TYPE ) 1 )\r
 522                         {\r
 523                                 /* As this is the first task it must also be the current task. */\r
 524                                 pxCurrentTCB =  pxNewTCB;\r
 525 \r
 526                                 /* This is the first task to be created so do the preliminary\r
 527                                 initialisation required.  We will not recover if this call\r
 528                                 fails, but we will report the failure. */\r
 529                                 prvInitialiseTaskLists();\r
 530                         }\r
 531                         else\r
 532                         {       \r
 533                                 /* If the scheduler is not already running, make this task the\r
 534                                 current task if it is the highest priority task to be created\r
 535                                 so far. */\r
 536                                 if( xSchedulerRunning == pdFALSE )\r
 537                                 {\r
 538                                         if( pxCurrentTCB->uxPriority <= uxPriority )\r
 539                                         {\r
 540                                                 pxCurrentTCB = pxNewTCB;        \r
 541                                         }\r
 542                                 }\r
 543                         }                               \r
 544 \r
 545                         /* Remember the top priority to make context switching faster.  Use\r
 546                         the priority in pxNewTCB as this has been capped to a valid value. */\r
 547                         if( pxNewTCB->uxPriority > uxTopUsedPriority )\r
 548                         {\r
 549                                 uxTopUsedPriority = pxNewTCB->uxPriority;\r
 550                         }\r
 551 \r
 552                         /* Add a counter into the TCB for tracing only. */\r
 553                         pxNewTCB->uxTCBNumber = uxTaskNumber;\r
 554                         uxTaskNumber++;\r
 555 \r
 556                         prvAddTaskToReadyQueue( pxNewTCB );\r
 557 \r
 558                         xReturn = pdPASS;\r
 559                 }\r
 560                 portEXIT_CRITICAL();\r
 561         }\r
 562         else\r
 563         {\r
 564                 xReturn = errCOULD_NOT_ALLOCATE_REQUIRED_MEMORY;\r
 565         }\r
 566 \r
 567         if( xReturn == pdPASS )\r
 568         {\r
 569                 if( ( void * ) pxCreatedTask != NULL )\r
 570                 {\r
 571                         /* Pass the TCB out - in an anonymous way.  The calling function/\r
 572                         task can use this as a handle to delete the task later if\r
 573                         required.*/\r
 574                         *pxCreatedTask = ( xTaskHandle ) pxNewTCB;\r
 575                 }\r
 576 \r
 577                 if( xSchedulerRunning != pdFALSE )\r
 578                 {\r
 579                         /* If the created task is of a higher priority than the current task\r
 580                         then it should run now. */\r
 581                         if( pxCurrentTCB->uxPriority < uxPriority )\r
 582                         {\r
 583                                 taskYIELD();\r
 584                         }\r
 585                 }\r
 586         }\r
 587 \r
 588         return xReturn;\r
 589 }\r
 590 /*-----------------------------------------------------------*/\r
 591 \r
 592 #if ( INCLUDE_vTaskDelete == 1 )\r
 593 \r
 594         void vTaskDelete( xTaskHandle pxTaskToDelete )\r
 595         {\r
 596         tskTCB *pxTCB;\r
 597 \r
 598                 taskENTER_CRITICAL();\r
 599                 {\r
 600                         /* Ensure a yield is performed if the current task is being \r
 601                         deleted. */\r
 602                         if( pxTaskToDelete == pxCurrentTCB )\r
 603                         {\r
 604                                 pxTaskToDelete = NULL;\r
 605                         }\r
 606 \r
 607                         /* If null is passed in here then we are deleting ourselves. */\r
 608                         pxTCB = prvGetTCBFromHandle( pxTaskToDelete );\r
 609 \r
 610                         /* Remove task from the ready list and place in the     termination list.\r
 611                         This will stop the task from be scheduled.  The idle task will check\r
 612                         the termination list and free up any memory allocated by the\r
 613                         scheduler for the TCB and stack. */\r
 614                         vListRemove( &( pxTCB->xGenericListItem ) );\r
 615 \r
 616                         /* Is the task waiting on an event also? */                                                                                             \r
 617                         if( pxTCB->xEventListItem.pvContainer )\r
 618                         {\r
 619                                 vListRemove( &( pxTCB->xEventListItem ) );\r
 620                         }\r
 621 \r
 622                         vListInsertEnd( ( xList * ) &xTasksWaitingTermination, &( pxTCB->xGenericListItem ) );\r
 623 \r
 624                         /* Increment the ucTasksDeleted variable so the idle task knows\r
 625                         there is a task that has been deleted and that it should therefore\r
 626                         check the xTasksWaitingTermination list. */\r
 627                         ++uxTasksDeleted;\r
 628                 }\r
 629                 taskEXIT_CRITICAL();\r
 630 \r
 631                 /* Force a reschedule if we have just deleted the current task. */\r
 632                 if( xSchedulerRunning != pdFALSE ) \r
 633                 {\r
 634                         if( ( void * ) pxTaskToDelete == NULL )\r
 635                         {\r
 636                                 taskYIELD();\r
 637                         }\r
 638                 }\r
 639         }\r
 640 \r
 641 #endif\r
 642 \r
 643 \r
 644 \r
 645 \r
 646 \r
 647 \r
 648 /*-----------------------------------------------------------\r
 649  * TASK CONTROL API documented in task.h\r
 650  *----------------------------------------------------------*/\r
 651 \r
 652 #if ( INCLUDE_vTaskDelayUntil == 1 )\r
 653 \r
 654         void vTaskDelayUntil( portTickType *pxPreviousWakeTime, portTickType xTimeIncrement )\r
 655         {\r
 656         portTickType xTimeToWake;\r
 657         portBASE_TYPE xAlreadyYielded, xShouldDelay = pdFALSE;\r
 658 \r
 659                 vTaskSuspendAll();\r
 660                 {\r
 661                         /* Generate the tick time at which the task wants to wake. */\r
 662                         xTimeToWake = *pxPreviousWakeTime + xTimeIncrement;\r
 663 \r
 664                         if( xTickCount < *pxPreviousWakeTime )\r
 665                         {\r
 666                                 /* The tick count has overflowed since this function was\r
 667                                 lasted called.  In this case the only time we should ever\r
 668                                 actually delay is if the wake time has also     overflowed,\r
 669                                 and the wake time is greater than the tick time.  When this\r
 670                                 is the case it is as if neither time had overflowed. */\r
 671                                 if( ( xTimeToWake < *pxPreviousWakeTime ) && ( xTimeToWake > xTickCount ) )\r
 672                                 {\r
 673                                         xShouldDelay = pdTRUE;\r
 674                                 }\r
 675                         }\r
 676                         else\r
 677                         {\r
 678                                 /* The tick time has not overflowed.  In this case we will\r
 679                                 delay if either the wake time has overflowed, and/or the\r
 680                                 tick time is less than the wake time. */\r
 681                                 if( ( xTimeToWake < *pxPreviousWakeTime ) || ( xTimeToWake > xTickCount ) )\r
 682                                 {\r
 683                                         xShouldDelay = pdTRUE;\r
 684                                 }\r
 685                         }\r
 686 \r
 687                         /* Update the wake time ready for the next call. */\r
 688                         *pxPreviousWakeTime = xTimeToWake;\r
 689 \r
 690                         if( xShouldDelay )\r
 691                         {\r
 692                                 /* We must remove ourselves from the ready list before adding\r
 693                                 ourselves to the blocked list as the same list item is used for\r
 694                                 both lists. */\r
 695                                 vListRemove( ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );\r
 696 \r
 697                                 /* The list item will be inserted in wake time order. */\r
 698                                 listSET_LIST_ITEM_VALUE( &( pxCurrentTCB->xGenericListItem ), xTimeToWake );\r
 699 \r
 700                                 if( xTimeToWake < xTickCount )\r
 701                                 {\r
 702                                         /* Wake time has overflowed.  Place this item in the\r
 703                                         overflow list. */\r
 704                                         vListInsert( ( xList * ) pxOverflowDelayedTaskList, ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );\r
 705                                 }\r
 706                                 else\r
 707                                 {\r
 708                                         /* The wake time has not overflowed, so we can use the\r
 709                                         current block list. */\r
 710                                         vListInsert( ( xList * ) pxDelayedTaskList, ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );\r
 711                                 }\r
 712                         }\r
 713                 }\r
 714                 xAlreadyYielded = xTaskResumeAll();\r
 715 \r
 716                 /* Force a reschedule if xTaskResumeAll has not already done so, we may\r
 717                 have put ourselves to sleep. */\r
 718                 if( !xAlreadyYielded )\r
 719                 {\r
 720                         taskYIELD();\r
 721                 }\r
 722         }       \r
 723         \r
 724 #endif\r
 725 /*-----------------------------------------------------------*/\r
 726 \r
 727 #if ( INCLUDE_vTaskDelay == 1 )\r
 728 \r
 729         void vTaskDelay( portTickType xTicksToDelay )\r
 730         {\r
 731         portTickType xTimeToWake;\r
 732         signed portBASE_TYPE xAlreadyYielded = pdFALSE;\r
 733 \r
 734                 /* A delay time of zero just forces a reschedule. */\r
 735                 if( xTicksToDelay > ( portTickType ) 0 )\r
 736                 {\r
 737                         vTaskSuspendAll();\r
 738                         {\r
 739                                 /* A task that is removed from the event list while the\r
 740                                 scheduler is suspended will not get placed in the ready\r
 741                                 list or removed from the blocked list until the scheduler\r
 742                                 is resumed.\r
 743                                 \r
 744                                 This task cannot be in an event list as it is the currently\r
 745                                 executing task. */\r
 746 \r
 747                                 /* Calculate the time to wake - this may overflow but this is\r
 748                                 not a problem. */\r
 749                                 xTimeToWake = xTickCount + xTicksToDelay;\r
 750 \r
 751                                 /* We must remove ourselves from the ready list before adding\r
 752                                 ourselves to the blocked list as the same list item is used for\r
 753                                 both lists. */\r
 754                                 vListRemove( ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );\r
 755 \r
 756                                 /* The list item will be inserted in wake time order. */\r
 757                                 listSET_LIST_ITEM_VALUE( &( pxCurrentTCB->xGenericListItem ), xTimeToWake );\r
 758 \r
 759                                 if( xTimeToWake < xTickCount )\r
 760                                 {\r
 761                                         /* Wake time has overflowed.  Place this item in the\r
 762                                         overflow list. */\r
 763                                         vListInsert( ( xList * ) pxOverflowDelayedTaskList, ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );\r
 764                                 }\r
 765                                 else\r
 766                                 {\r
 767                                         /* The wake time has not overflowed, so we can use the\r
 768                                         current block list. */\r
 769                                         vListInsert( ( xList * ) pxDelayedTaskList, ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );\r
 770                                 }\r
 771                         }\r
 772                         xAlreadyYielded = xTaskResumeAll();\r
 773                 }\r
 774                 \r
 775                 /* Force a reschedule if xTaskResumeAll has not already done so, we may\r
 776                 have put ourselves to sleep. */\r
 777                 if( !xAlreadyYielded )\r
 778                 {\r
 779                         taskYIELD();\r
 780                 }\r
 781         }\r
 782         \r
 783 #endif\r
 784 /*-----------------------------------------------------------*/\r
 785 \r
 786 #if ( INCLUDE_uxTaskPriorityGet == 1 )\r
 787 \r
 788         unsigned portBASE_TYPE uxTaskPriorityGet( xTaskHandle pxTask )\r
 789         {\r
 790         tskTCB *pxTCB;\r
 791         unsigned portBASE_TYPE uxReturn;\r
 792 \r
 793                 taskENTER_CRITICAL();\r
 794                 {\r
 795                         /* If null is passed in here then we are changing the\r
 796                         priority of the calling function. */\r
 797                         pxTCB = prvGetTCBFromHandle( pxTask );\r
 798                         uxReturn = pxTCB->uxPriority;\r
 799                 }\r
 800                 taskEXIT_CRITICAL();\r
 801 \r
 802                 return uxReturn;\r
 803         }\r
 804 \r
 805 #endif\r
 806 /*-----------------------------------------------------------*/\r
 807 \r
 808 #if ( INCLUDE_vTaskPrioritySet == 1 )\r
 809 \r
 810         void vTaskPrioritySet( xTaskHandle pxTask, unsigned portBASE_TYPE uxNewPriority )\r
 811         {\r
 812         tskTCB *pxTCB;\r
 813         unsigned portBASE_TYPE uxCurrentPriority, xYieldRequired = pdFALSE;\r
 814 \r
 815                 /* Ensure the new priority is valid. */\r
 816                 if( uxNewPriority >= configMAX_PRIORITIES )\r
 817                 {\r
 818                         uxNewPriority = configMAX_PRIORITIES - 1;\r
 819                 }\r
 820 \r
 821                 taskENTER_CRITICAL();\r
 822                 {\r
 823                         /* If null is passed in here then we are changing the\r
 824                         priority of the calling function. */\r
 825                         pxTCB = prvGetTCBFromHandle( pxTask );\r
 826                         uxCurrentPriority = pxTCB->uxPriority;\r
 827 \r
 828                         if( uxCurrentPriority != uxNewPriority )\r
 829                         {\r
 830                                 /* The priority change may have readied a task of higher\r
 831                                 priority than the calling task. */\r
 832                                 if( uxNewPriority > pxCurrentTCB->uxPriority ) \r
 833                                 {\r
 834                                         if( pxTask != NULL )\r
 835                                         {\r
 836                                                 /* The priority of another task is being raised.  If we\r
 837                                                 were raising the priority of the currently running task\r
 838                                                 there would be no need to switch as it must have already\r
 839                                                 been the highest priority task. */\r
 840                                                 xYieldRequired = pdTRUE;\r
 841                                         }\r
 842                                 }\r
 843                                 else if( pxTask == NULL )\r
 844                                 {\r
 845                                         /* Setting our own priority down means there may now be another\r
 846                                         task of higher priority that is ready to execute. */\r
 847                                         xYieldRequired = pdTRUE;\r
 848                                 }\r
 849                         \r
 850                                 pxTCB->uxPriority = uxNewPriority;\r
 851                                 listSET_LIST_ITEM_VALUE( &( pxTCB->xEventListItem ), configMAX_PRIORITIES - ( portTickType ) uxNewPriority );\r
 852 \r
 853                                 /* If the task is in the blocked or suspended list we need do\r
 854                                 nothing more than change it's priority variable. However, if\r
 855                                 the task is in a ready list it needs to be removed and placed\r
 856                                 in the queue appropriate to its new priority. */\r
 857                                 if( listIS_CONTAINED_WITHIN( &( pxReadyTasksLists[ uxCurrentPriority ] ), &( pxTCB->xGenericListItem ) ) )\r
 858                                 {\r
 859                                         /* The task is currently in its ready list - remove before adding\r
 860                                         it to it's new ready list.  As we are in a critical section we\r
 861                                         can do this even if the scheduler is suspended. */\r
 862                                         vListRemove( &( pxTCB->xGenericListItem ) );\r
 863                                         prvAddTaskToReadyQueue( pxTCB );\r
 864                                 }                       \r
 865                                 \r
 866                                 if( xYieldRequired == pdTRUE )\r
 867                                 {\r
 868                                         taskYIELD();\r
 869                                 }                               \r
 870                         }\r
 871                 }\r
 872                 taskEXIT_CRITICAL();\r
 873         }\r
 874 \r
 875 #endif\r
 876 /*-----------------------------------------------------------*/\r
 877 \r
 878 #if ( INCLUDE_vTaskSuspend == 1 )\r
 879 \r
 880         void vTaskSuspend( xTaskHandle pxTaskToSuspend )\r
 881         {\r
 882         tskTCB *pxTCB;\r
 883 \r
 884                 taskENTER_CRITICAL();\r
 885                 {\r
 886                         /* Ensure a yield is performed if the current task is being \r
 887                         suspended. */\r
 888                         if( pxTaskToSuspend == pxCurrentTCB )\r
 889                         {\r
 890                                 pxTaskToSuspend = NULL;\r
 891                         }\r
 892 \r
 893                         /* If null is passed in here then we are suspending ourselves. */\r
 894                         pxTCB = prvGetTCBFromHandle( pxTaskToSuspend );\r
 895 \r
 896                         /* Remove task from the ready/delayed list and place in the     suspended list. */\r
 897                         vListRemove( &( pxTCB->xGenericListItem ) );\r
 898 \r
 899                         /* Is the task waiting on an event also? */                                                                                             \r
 900                         if( pxTCB->xEventListItem.pvContainer )\r
 901                         {\r
 902                                 vListRemove( &( pxTCB->xEventListItem ) );\r
 903                         }\r
 904 \r
 905                         vListInsertEnd( ( xList * ) &xSuspendedTaskList, &( pxTCB->xGenericListItem ) );\r
 906                 }\r
 907                 taskEXIT_CRITICAL();\r
 908 \r
 909                 /* We may have just suspended the current task. */\r
 910                 if( ( void * ) pxTaskToSuspend == NULL )\r
 911                 {\r
 912                         taskYIELD();\r
 913                 }\r
 914         }\r
 915 \r
 916 #endif\r
 917 /*-----------------------------------------------------------*/\r
 918 \r
 919 #if ( INCLUDE_vTaskSuspend == 1 )\r
 920 \r
 921         void vTaskResume( xTaskHandle pxTaskToResume )\r
 922         {\r
 923         tskTCB *pxTCB;\r
 924 \r
 925                 /* Remove the task from whichever list it is currently in, and place\r
 926                 it in the ready list. */\r
 927                 pxTCB = ( tskTCB * ) pxTaskToResume;\r
 928 \r
 929                 /* The parameter cannot be NULL as it is impossible to resume the\r
 930                 currently executing task. */\r
 931                 if( pxTCB != NULL )\r
 932                 {\r
 933                         taskENTER_CRITICAL();\r
 934                         {\r
 935                                 /* Is the task we are attempting to resume actually suspended? */\r
 936                                 if( listIS_CONTAINED_WITHIN( &xSuspendedTaskList, &( pxTCB->xGenericListItem ) ) != pdFALSE )\r
 937                                 {\r
 938                                         /* Has the task already been resumed from within an ISR? */\r
 939                                         if( listIS_CONTAINED_WITHIN( &xPendingReadyList, &( pxTCB->xEventListItem ) ) != pdTRUE )\r
 940                                         {                       \r
 941                                                 /* As we are in a critical section we can access the ready \r
 942                                                 lists even if the scheduler is suspended. */\r
 943                                                 vListRemove(  &( pxTCB->xGenericListItem ) );\r
 944                                                 prvAddTaskToReadyQueue( pxTCB );\r
 945 \r
 946                                                 /* We may have just resumed a higher priority task. */\r
 947                                                 if( pxTCB->uxPriority >= pxCurrentTCB->uxPriority )\r
 948                                                 {\r
 949                                                         /* This yield may not cause the task just resumed to run, but\r
 950                                                         will leave the lists in the correct state for the next yield. */\r
 951                                                         taskYIELD();\r
 952                                                 }\r
 953                                         }\r
 954                                 }\r
 955                         }\r
 956                         taskEXIT_CRITICAL();\r
 957                 }\r
 958         }\r
 959 \r
 960 #endif\r
 961 \r
 962 /*-----------------------------------------------------------*/\r
 963 \r
 964 #if ( INCLUDE_xTaskResumeFromISR == 1 )\r
 965 \r
 966         portBASE_TYPE xTaskResumeFromISR( xTaskHandle pxTaskToResume )\r
 967         {\r
 968         portBASE_TYPE xYieldRequired = pdFALSE;\r
 969         tskTCB *pxTCB;\r
 970 \r
 971                 pxTCB = ( tskTCB * ) pxTaskToResume;\r
 972 \r
 973                 /* Is the task we are attempting to resume actually suspended? */\r
 974                 if( listIS_CONTAINED_WITHIN( &xSuspendedTaskList, &( pxTCB->xGenericListItem ) ) != pdFALSE )\r
 975                 {\r
 976                         /* Has the task already been resumed from within an ISR? */\r
 977                         if( listIS_CONTAINED_WITHIN( &xPendingReadyList, &( pxTCB->xEventListItem ) ) != pdTRUE )\r
 978                         {\r
 979                                 if( uxSchedulerSuspended == ( unsigned portBASE_TYPE ) pdFALSE )\r
 980                                 {\r
 981                                         xYieldRequired = ( pxTCB->uxPriority >= pxCurrentTCB->uxPriority );\r
 982                                         vListRemove(  &( pxTCB->xGenericListItem ) );   \r
 983                                         prvAddTaskToReadyQueue( pxTCB );\r
 984                                 }\r
 985                                 else\r
 986                                 {\r
 987                                         /* We cannot access the delayed or ready lists, so will hold this\r
 988                                         task pending until the scheduler is resumed, at which point a \r
 989                                         yield will be preformed if necessary. */\r
 990                                         vListInsertEnd( ( xList * ) &( xPendingReadyList ), &( pxTCB->xEventListItem ) );\r
 991                                 }\r
 992                         }\r
 993                 }\r
 994 \r
 995                 return xYieldRequired;\r
 996         }\r
 997 \r
 998 #endif\r
 999 \r
1000 \r
1001 \r
1002 \r
1003 /*-----------------------------------------------------------\r
1004  * PUBLIC SCHEDULER CONTROL documented in task.h\r
1005  *----------------------------------------------------------*/\r
1006 \r
1007 \r
1008 void vTaskStartScheduler( void )\r
1009 {\r
1010 portBASE_TYPE xReturn;\r
1011 \r
1012         /* Add the idle task at the lowest priority. */\r
1013         xReturn = xTaskCreate( prvIdleTask, ( signed portCHAR * ) "IDLE", tskIDLE_STACK_SIZE, ( void * ) NULL, tskIDLE_PRIORITY, ( xTaskHandle * ) NULL );\r
1014 \r
1015         if( xReturn == pdPASS )\r
1016         {\r
1017                 /* Interrupts are turned off here, to ensure a tick does not occur\r
1018                 before or during the call to xPortStartScheduler().  The stacks of\r
1019                 the created tasks contain a status word with interrupts switched on\r
1020                 so interrupts will automatically get re-enabled when the first task\r
1021                 starts to run.\r
1022                 \r
1023                 STEPPING THROUGH HERE USING A DEBUGGER CAN CAUSE BIG PROBLEMS IF THE\r
1024                 DEBUGGER ALLOWS INTERRUPTS TO BE PROCESSED. */\r
1025                 portDISABLE_INTERRUPTS();\r
1026 \r
1027                 xSchedulerRunning = pdTRUE;\r
1028                 xTickCount = ( portTickType ) 0;\r
1029 \r
1030                 /* Setting up the timer tick is hardware specific and thus in the\r
1031                 portable interface. */\r
1032                 if( xPortStartScheduler() )\r
1033                 {\r
1034                         /* Should not reach here as if the scheduler is running the\r
1035                         function will not return. */\r
1036                 }\r
1037                 else\r
1038                 {\r
1039                         /* Should only reach here if a task calls xTaskEndScheduler(). */\r
1040                 }\r
1041         }\r
1042 }\r
1043 /*-----------------------------------------------------------*/\r
1044 \r
1045 void vTaskEndScheduler( void )\r
1046 {\r
1047         /* Stop the scheduler interrupts and call the portable scheduler end\r
1048         routine so the original ISRs can be restored if necessary.  The port\r
1049         layer must ensure interrupts enable     bit is left in the correct state. */\r
1050         portDISABLE_INTERRUPTS();\r
1051         xSchedulerRunning = pdFALSE;\r
1052         vPortEndScheduler();\r
1053 }\r
1054 /*----------------------------------------------------------*/\r
1055 \r
1056 void vTaskSuspendAll( void )\r
1057 {\r
1058         portENTER_CRITICAL();\r
1059                 ++uxSchedulerSuspended;\r
1060         portEXIT_CRITICAL();\r
1061 }\r
1062 /*----------------------------------------------------------*/\r
1063 \r
1064 signed portBASE_TYPE xTaskResumeAll( void )\r
1065 {\r
1066 register tskTCB *pxTCB;\r
1067 signed portBASE_TYPE xAlreadyYielded = pdFALSE;\r
1068 \r
1069         /* It is possible that an ISR caused a task to be removed from an event\r
1070         list while the scheduler was suspended.  If this was the case then the\r
1071         removed task will have been added to the xPendingReadyList.  Once the\r
1072         scheduler has been resumed it is safe to move all the pending ready\r
1073         tasks from this list into their appropriate ready list. */\r
1074         portENTER_CRITICAL();\r
1075         {\r
1076                 --uxSchedulerSuspended;\r
1077 \r
1078                 if( uxSchedulerSuspended == ( unsigned portBASE_TYPE ) pdFALSE )\r
1079                 {                       \r
1080                         if( uxCurrentNumberOfTasks > ( unsigned portBASE_TYPE ) 0 )\r
1081                         {\r
1082                                 portBASE_TYPE xYieldRequired = pdFALSE;\r
1083                                 \r
1084                                 /* Move any readied tasks from the pending list into the\r
1085                                 appropriate ready list. */\r
1086                                 while( ( pxTCB = ( tskTCB * ) listGET_OWNER_OF_HEAD_ENTRY(  ( ( xList * ) &xPendingReadyList ) ) ) != NULL )\r
1087                                 {\r
1088                                         vListRemove( &( pxTCB->xEventListItem ) );\r
1089                                         vListRemove( &( pxTCB->xGenericListItem ) );\r
1090                                         prvAddTaskToReadyQueue( pxTCB );\r
1091                                         \r
1092                                         /* If we have moved a task that has a priority higher than\r
1093                                         the current task then we should yield. */\r
1094                                         if( pxTCB->uxPriority >= pxCurrentTCB->uxPriority )\r
1095                                         {\r
1096                                                 xYieldRequired = pdTRUE;\r
1097                                         }\r
1098                                 }\r
1099 \r
1100                                 /* If any ticks occurred while the scheduler was suspended then\r
1101                                 they should be processed now.  This ensures the tick count does not\r
1102                                 slip, and that any delayed tasks are resumed at the correct time. */\r
1103                                 if( uxMissedTicks > ( unsigned portBASE_TYPE ) 0 )\r
1104                                 {\r
1105                                         while( uxMissedTicks > ( unsigned portBASE_TYPE ) 0 )\r
1106                                         {\r
1107                                                 vTaskIncrementTick();\r
1108                                                 --uxMissedTicks;\r
1109                                         }\r
1110 \r
1111                                         /* As we have processed some ticks it is appropriate to yield\r
1112                                         to ensure the highest priority task that is ready to run is\r
1113                                         the task actually running. */\r
1114                                         xYieldRequired = pdTRUE;\r
1115                                 }\r
1116                                 \r
1117                                 if( ( xYieldRequired == pdTRUE ) || ( xMissedYield == pdTRUE ) )\r
1118                                 {\r
1119                                         xAlreadyYielded = pdTRUE;\r
1120                                         xMissedYield = pdFALSE;\r
1121                                         taskYIELD();\r
1122                                 }\r
1123                         }\r
1124                 }\r
1125         }\r
1126         portEXIT_CRITICAL();\r
1127 \r
1128         return xAlreadyYielded;\r
1129 }\r
1130 \r
1131 \r
1132 \r
1133 \r
1134 \r
1135 \r
1136 /*-----------------------------------------------------------\r
1137  * PUBLIC TASK UTILITIES documented in task.h\r
1138  *----------------------------------------------------------*/\r
1139 \r
1140 \r
1141 \r
1142 portTickType xTaskGetTickCount( void )\r
1143 {\r
1144 portTickType xTicks;\r
1145 \r
1146         /* Critical section required if running on a 16 bit processor. */\r
1147         taskENTER_CRITICAL();\r
1148         {\r
1149                 xTicks = xTickCount;\r
1150         }\r
1151         taskEXIT_CRITICAL();\r
1152 \r
1153         return xTicks;\r
1154 }\r
1155 /*-----------------------------------------------------------*/\r
1156 \r
1157 unsigned portBASE_TYPE uxTaskGetNumberOfTasks( void )\r
1158 {\r
1159 unsigned portBASE_TYPE uxNumberOfTasks;\r
1160 \r
1161         taskENTER_CRITICAL();\r
1162                 uxNumberOfTasks = uxCurrentNumberOfTasks;\r
1163         taskEXIT_CRITICAL();\r
1164 \r
1165         return uxNumberOfTasks;\r
1166 }\r
1167 /*-----------------------------------------------------------*/\r
1168 \r
1169 #if ( ( configUSE_TRACE_FACILITY == 1 ) && ( INCLUDE_vTaskDelete == 1 ) && ( INCLUDE_vTaskSuspend == 1 ) )\r
1170 \r
1171         void vTaskList( signed portCHAR *pcWriteBuffer )\r
1172         {\r
1173         unsigned portBASE_TYPE uxQueue;\r
1174 \r
1175                 /* This is a VERY costly function that should be used for debug only.\r
1176                 It leaves interrupts disabled for a LONG time. */\r
1177 \r
1178         vTaskSuspendAll();\r
1179                 {\r
1180                         /* Run through all the lists that could potentially contain a TCB and\r
1181                         report the task name, state and stack high water mark. */\r
1182 \r
1183                         pcWriteBuffer[ 0 ] = ( signed portCHAR ) 0x00;\r
1184                         strcat( ( portCHAR * ) pcWriteBuffer, ( const portCHAR * ) "\r\n" );\r
1185 \r
1186                         uxQueue = uxTopUsedPriority + 1;\r
1187 \r
1188                         do\r
1189                         {\r
1190                                 uxQueue--;\r
1191 \r
1192                                 if( !listLIST_IS_EMPTY( &( pxReadyTasksLists[ uxQueue ] ) ) )\r
1193                                 {\r
1194                                         prvListTaskWithinSingleList( pcWriteBuffer, ( xList * ) &( pxReadyTasksLists[ uxQueue ] ), tskREADY_CHAR );                     \r
1195                                 }\r
1196                         }while( uxQueue > ( unsigned portSHORT ) tskIDLE_PRIORITY );\r
1197 \r
1198                         if( !listLIST_IS_EMPTY( pxDelayedTaskList ) )\r
1199                         {\r
1200                                 prvListTaskWithinSingleList( pcWriteBuffer, ( xList * ) pxDelayedTaskList, tskBLOCKED_CHAR );\r
1201                         }\r
1202 \r
1203                         if( !listLIST_IS_EMPTY( pxOverflowDelayedTaskList ) )\r
1204                         {\r
1205                                 prvListTaskWithinSingleList( pcWriteBuffer, ( xList * ) pxOverflowDelayedTaskList, tskBLOCKED_CHAR );\r
1206                         }\r
1207 \r
1208                         if( !listLIST_IS_EMPTY( &xTasksWaitingTermination ) )\r
1209                         {\r
1210                                 prvListTaskWithinSingleList( pcWriteBuffer, ( xList * ) &xTasksWaitingTermination, tskDELETED_CHAR );\r
1211                         }\r
1212 \r
1213                         if( !listLIST_IS_EMPTY( &xSuspendedTaskList ) )\r
1214                         {\r
1215                                 prvListTaskWithinSingleList( pcWriteBuffer, ( xList * ) &xSuspendedTaskList, tskSUSPENDED_CHAR );\r
1216                         }\r
1217                 }\r
1218         xTaskResumeAll();\r
1219         }\r
1220 \r
1221 #endif\r
1222 /*----------------------------------------------------------*/\r
1223 \r
1224 #if ( configUSE_TRACE_FACILITY == 1 )\r
1225 \r
1226         void vTaskStartTrace( signed portCHAR * pcBuffer, unsigned portLONG ulBufferSize )\r
1227         {\r
1228                 portENTER_CRITICAL();\r
1229                 {\r
1230                         pcTraceBuffer = ( volatile signed portCHAR * volatile )pcBuffer;\r
1231                         pcTraceBufferStart = pcBuffer;\r
1232                         pcTraceBufferEnd = pcBuffer + ( ulBufferSize - tskSIZE_OF_EACH_TRACE_LINE );\r
1233                         xTracing = pdTRUE;\r
1234                 }\r
1235                 portEXIT_CRITICAL();\r
1236         }\r
1237 \r
1238 #endif\r
1239 /*----------------------------------------------------------*/\r
1240 \r
1241 #if ( configUSE_TRACE_FACILITY == 1 )\r
1242 \r
1243         unsigned portLONG ulTaskEndTrace( void )\r
1244         {\r
1245         unsigned portLONG ulBufferLength;\r
1246 \r
1247                 portENTER_CRITICAL();\r
1248                         xTracing = pdFALSE;\r
1249                 portEXIT_CRITICAL();\r
1250 \r
1251                 ulBufferLength = ( unsigned portLONG ) ( pcTraceBuffer - pcTraceBufferStart );\r
1252 \r
1253                 return ulBufferLength;\r
1254         }\r
1255 \r
1256 #endif\r
1257 \r
1258 \r
1259 \r
1260 /*-----------------------------------------------------------\r
1261  * SCHEDULER INTERNALS AVAILABLE FOR PORTING PURPOSES\r
1262  * documented in task.h\r
1263  *----------------------------------------------------------*/\r
1264 \r
1265 \r
1266 inline void vTaskIncrementTick( void )\r
1267 {\r
1268         /* Called by the portable layer each time a tick interrupt occurs.\r
1269         Increments the tick then checks to see if the new tick value will cause any\r
1270         tasks to be unblocked. */\r
1271         if( uxSchedulerSuspended == ( unsigned portBASE_TYPE ) pdFALSE )\r
1272         {\r
1273                 ++xTickCount;\r
1274                 if( xTickCount == ( portTickType ) 0 )\r
1275                 {\r
1276                         xList *pxTemp;\r
1277 \r
1278                         /* Tick count has overflowed so we need to swap the delay lists.  \r
1279                         If there are any items in pxDelayedTaskList here then there is \r
1280                         an error! */\r
1281                         pxTemp = pxDelayedTaskList;\r
1282                         pxDelayedTaskList = pxOverflowDelayedTaskList;\r
1283                         pxOverflowDelayedTaskList = pxTemp;\r
1284                 }\r
1285 \r
1286                 /* See if this tick has made a timeout expire. */\r
1287                 prvCheckDelayedTasks();\r
1288         }\r
1289         else\r
1290         {\r
1291                 ++uxMissedTicks;\r
1292 \r
1293                 /* The tick hook gets called at regular intervals, even if the \r
1294                 scheduler is locked. */\r
1295                 #if ( configUSE_TICK_HOOK == 1 )\r
1296                 {\r
1297                         extern void vApplicationTickHook( void );\r
1298 \r
1299                         vApplicationTickHook();\r
1300                 }\r
1301                 #endif\r
1302         }\r
1303 \r
1304         #if ( configUSE_TICK_HOOK == 1 )\r
1305         {\r
1306                 extern void vApplicationTickHook( void );\r
1307 \r
1308                 /* Guard against the tick hook being called when the missed tick\r
1309                 count is being unwound (when the scheduler is being unlocked. */\r
1310                 if( uxMissedTicks == 0 )\r
1311                 {\r
1312                         vApplicationTickHook();\r
1313                 }\r
1314         }\r
1315         #endif\r
1316 }\r
1317 /*-----------------------------------------------------------*/\r
1318 \r
1319 #if ( ( INCLUDE_vTaskCleanUpResources == 1 ) && ( INCLUDE_vTaskSuspend == 1 ) )\r
1320 \r
1321         void vTaskCleanUpResources( void )\r
1322         {\r
1323         unsigned portSHORT usQueue;\r
1324         volatile tskTCB *pxTCB;\r
1325 \r
1326                 usQueue = ( unsigned portSHORT ) uxTopUsedPriority + ( unsigned portSHORT ) 1;\r
1327 \r
1328                 /* Remove any TCB's from the ready queues. */\r
1329                 do\r
1330                 {\r
1331                         usQueue--;\r
1332 \r
1333                         while( !listLIST_IS_EMPTY( &( pxReadyTasksLists[ usQueue ] ) ) )\r
1334                         {\r
1335                                 listGET_OWNER_OF_NEXT_ENTRY( pxTCB, &( pxReadyTasksLists[ usQueue ] ) );\r
1336                                 vListRemove( ( xListItem * ) &( pxTCB->xGenericListItem ) );\r
1337 \r
1338                                 prvDeleteTCB( ( tskTCB * ) pxTCB );\r
1339                         }\r
1340                 }while( usQueue > ( unsigned portSHORT ) tskIDLE_PRIORITY );\r
1341 \r
1342                 /* Remove any TCB's from the delayed queue. */\r
1343                 while( !listLIST_IS_EMPTY( &xDelayedTaskList1 ) )\r
1344                 {\r
1345                         listGET_OWNER_OF_NEXT_ENTRY( pxTCB, &xDelayedTaskList1 );\r
1346                         vListRemove( ( xListItem * ) &( pxTCB->xGenericListItem ) );\r
1347 \r
1348                         prvDeleteTCB( ( tskTCB * ) pxTCB );\r
1349                 }\r
1350 \r
1351                 /* Remove any TCB's from the overflow delayed queue. */\r
1352                 while( !listLIST_IS_EMPTY( &xDelayedTaskList2 ) )\r
1353                 {\r
1354                         listGET_OWNER_OF_NEXT_ENTRY( pxTCB, &xDelayedTaskList2 );\r
1355                         vListRemove( ( xListItem * ) &( pxTCB->xGenericListItem ) );\r
1356 \r
1357                         prvDeleteTCB( ( tskTCB * ) pxTCB );\r
1358                 }\r
1359 \r
1360                 while( !listLIST_IS_EMPTY( &xSuspendedTaskList ) )\r
1361                 {\r
1362                         listGET_OWNER_OF_NEXT_ENTRY( pxTCB, &xSuspendedTaskList );\r
1363                         vListRemove( ( xListItem * ) &( pxTCB->xGenericListItem ) );\r
1364 \r
1365                         prvDeleteTCB( ( tskTCB * ) pxTCB );\r
1366                 }               \r
1367 \r
1368                 while( !listLIST_IS_EMPTY( &xPendingReadyList ) )\r
1369                 {\r
1370                         listGET_OWNER_OF_NEXT_ENTRY( pxTCB, &xPendingReadyList );\r
1371                         vListRemove( ( xListItem * ) &( pxTCB->xGenericListItem ) );\r
1372 \r
1373                         prvDeleteTCB( ( tskTCB * ) pxTCB );\r
1374                 }               \r
1375         }\r
1376 \r
1377 #endif\r
1378 /*-----------------------------------------------------------*/\r
1379 \r
1380 void vTaskSwitchContext( void )\r
1381 {\r
1382         if( uxSchedulerSuspended != ( unsigned portBASE_TYPE ) pdFALSE )\r
1383         {\r
1384                 /* The scheduler is currently suspended - do not allow a context\r
1385                 switch. */\r
1386                 xMissedYield = pdTRUE;\r
1387                 return;\r
1388         }\r
1389 \r
1390         /* Find the highest priority queue that contains ready tasks. */\r
1391         while( listLIST_IS_EMPTY( &( pxReadyTasksLists[ uxTopReadyPriority ] ) ) )\r
1392         {\r
1393                 --uxTopReadyPriority;\r
1394         }\r
1395 \r
1396         /* listGET_OWNER_OF_NEXT_ENTRY walks through the list, so the tasks of the\r
1397         same priority get an equal share of the processor time. */\r
1398         listGET_OWNER_OF_NEXT_ENTRY( pxCurrentTCB, &( pxReadyTasksLists[ uxTopReadyPriority ] ) );\r
1399         vWriteTraceToBuffer();\r
1400 }\r
1401 /*-----------------------------------------------------------*/\r
1402 \r
1403 void vTaskPlaceOnEventList( xList *pxEventList, portTickType xTicksToWait )\r
1404 {\r
1405 portTickType xTimeToWake;\r
1406 \r
1407         /* THIS FUNCTION MUST BE CALLED WITH INTERRUPTS DISABLED OR THE\r
1408         SCHEDULER SUSPENDED. */\r
1409 \r
1410         /* Place the event list item of the TCB in the appropriate event list.\r
1411         This is placed in the list in priority order so the highest priority task\r
1412         is the first to be woken by the event. */\r
1413         vListInsert( ( xList * ) pxEventList, ( xListItem * ) &( pxCurrentTCB->xEventListItem ) );\r
1414 \r
1415         /* Calculate the time at which the task should be woken if the event does\r
1416         not occur.  This may overflow but this doesn't matter. */\r
1417         xTimeToWake = xTickCount + xTicksToWait;\r
1418 \r
1419         /* We must remove ourselves from the ready list before adding ourselves\r
1420         to the blocked list as the same list item is used for both lists.  We have\r
1421         exclusive access to the ready lists as the scheduler is locked. */\r
1422         vListRemove( ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );\r
1423 \r
1424         listSET_LIST_ITEM_VALUE( &( pxCurrentTCB->xGenericListItem ), xTimeToWake );\r
1425 \r
1426         if( xTimeToWake < xTickCount )\r
1427         {\r
1428                 /* Wake time has overflowed.  Place this item in the overflow list. */\r
1429                 vListInsert( ( xList * ) pxOverflowDelayedTaskList, ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );\r
1430         }\r
1431         else\r
1432         {\r
1433                 /* The wake time has not overflowed, so we can use the current block list. */\r
1434                 vListInsert( ( xList * ) pxDelayedTaskList, ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );\r
1435         }\r
1436 }\r
1437 /*-----------------------------------------------------------*/\r
1438 \r
1439 signed portBASE_TYPE xTaskRemoveFromEventList( const xList *pxEventList )\r
1440 {\r
1441 tskTCB *pxUnblockedTCB;\r
1442 portBASE_TYPE xReturn;\r
1443 \r
1444         /* THIS FUNCTION MUST BE CALLED WITH INTERRUPTS DISABLED OR THE\r
1445         SCHEDULER SUSPENDED.  It can also be called from within an ISR. */\r
1446 \r
1447         /* The event list is sorted in priority order, so we can remove the\r
1448         first in the list, remove the TCB from the delayed list, and add\r
1449         it to the ready list.\r
1450         \r
1451         If an event is for a queue that is locked then this function will never\r
1452         get called - the lock count on the queue will get modified instead.  This\r
1453         means we can always expect exclusive access to the event list here. */\r
1454         pxUnblockedTCB = ( tskTCB * ) listGET_OWNER_OF_HEAD_ENTRY( pxEventList );\r
1455         vListRemove( &( pxUnblockedTCB->xEventListItem ) );\r
1456 \r
1457         if( uxSchedulerSuspended == ( unsigned portBASE_TYPE ) pdFALSE )\r
1458         {\r
1459                 vListRemove( &( pxUnblockedTCB->xGenericListItem ) );\r
1460                 prvAddTaskToReadyQueue( pxUnblockedTCB );\r
1461         }\r
1462         else\r
1463         {\r
1464                 /* We cannot access the delayed or ready lists, so will hold this\r
1465                 task pending until the scheduler is resumed. */\r
1466                 vListInsertEnd( ( xList * ) &( xPendingReadyList ), &( pxUnblockedTCB->xEventListItem ) );\r
1467         }\r
1468 \r
1469         if( pxUnblockedTCB->uxPriority >= pxCurrentTCB->uxPriority )\r
1470         {\r
1471                 /* Return true if the task removed from the event list has\r
1472                 a higher priority than the calling task.  This allows\r
1473                 the calling task to know if it should force a context\r
1474                 switch now. */\r
1475                 xReturn = pdTRUE;\r
1476         }\r
1477         else\r
1478         {\r
1479                 xReturn = pdFALSE;\r
1480         }\r
1481 \r
1482         return xReturn;\r
1483 }\r
1484 \r
1485 \r
1486 \r
1487 \r
1488 \r
1489 /*\r
1490  * -----------------------------------------------------------\r
1491  * The Idle task.\r
1492  * ----------------------------------------------------------\r
1493  *\r
1494  * The portTASK_FUNCTION() macro is used to allow port/compiler specific\r
1495  * language extensions.  The equivalent prototype for this function is:\r
1496  *\r
1497  * void prvIdleTask( void *pvParameters );\r
1498  *\r
1499  */\r
1500 static portTASK_FUNCTION( prvIdleTask, pvParameters )\r
1501 {\r
1502         /* Stop warnings. */\r
1503         ( void ) pvParameters;\r
1504 \r
1505         for( ;; )\r
1506         {\r
1507                 /* See if any tasks have been deleted. */\r
1508                 prvCheckTasksWaitingTermination();\r
1509 \r
1510                 #if ( configUSE_PREEMPTION == 0 )\r
1511                 {\r
1512                         /* If we are not using preemption we keep forcing a task switch to\r
1513                         see if any other task has become available.  If we are using\r
1514                         preemption we don't need to do this as any task becoming available\r
1515                         will automatically get the processor anyway. */\r
1516                         taskYIELD();    \r
1517                 }\r
1518                 #endif\r
1519 \r
1520                 #if ( ( configUSE_PREEMPTION == 1 ) && ( configIDLE_SHOULD_YIELD == 1 ) )\r
1521                 {\r
1522                         /* When using preemption tasks of equal priority will be\r
1523                         timesliced.  If a task that is sharing the idle priority is ready\r
1524                         to run then the idle task should yield before the end of the\r
1525                         timeslice.\r
1526                         \r
1527                         A critical region is not required here as we are just reading from\r
1528                         the list, and an occasional incorrect value will not matter.  If\r
1529                         the ready list at the idle priority contains more than one task\r
1530                         then a task other than the idle task is ready to execute. */\r
1531                         if( listCURRENT_LIST_LENGTH( &( pxReadyTasksLists[ tskIDLE_PRIORITY ] ) ) > ( unsigned portBASE_TYPE ) 1 )\r
1532                         {\r
1533                                 taskYIELD();\r
1534                         }\r
1535                 }\r
1536                 #endif\r
1537 \r
1538                 #if ( configUSE_IDLE_HOOK == 1 )\r
1539                 {\r
1540                         extern void vApplicationIdleHook( void );\r
1541 \r
1542                         /* Call the user defined function from within the idle task.  This\r
1543                         allows the application designer to add background functionality\r
1544                         without the overhead of a separate task.\r
1545                         NOTE: vApplicationIdleHook() MUST NOT, UNDER ANY CIRCUMSTANCES,\r
1546                         CALL A FUNCTION THAT MIGHT BLOCK. */\r
1547                         vApplicationIdleHook();\r
1548                 }\r
1549                 #endif\r
1550         }\r
1551 } /*lint !e715 pvParameters is not accessed but all task functions require the same prototype. */\r
1552 \r
1553 \r
1554 \r
1555 \r
1556 \r
1557 \r
1558 \r
1559 /*-----------------------------------------------------------\r
1560  * File private functions documented at the top of the file.\r
1561  *----------------------------------------------------------*/\r
1562 \r
1563 \r
1564 \r
1565 static void prvInitialiseTCBVariables( tskTCB *pxTCB, unsigned portSHORT usStackDepth, const signed portCHAR * const pcName, unsigned portBASE_TYPE uxPriority )\r
1566 {\r
1567         pxTCB->usStackDepth = usStackDepth;\r
1568 \r
1569         /* Store the function name in the TCB. */\r
1570         strncpy( ( char * ) pxTCB->pcTaskName, ( const char * ) pcName, ( unsigned portSHORT ) configMAX_TASK_NAME_LEN );\r
1571         pxTCB->pcTaskName[ ( unsigned portSHORT ) configMAX_TASK_NAME_LEN - ( unsigned portSHORT ) 1 ] = '\0';\r
1572 \r
1573         /* This is used as an array index so must ensure it's not too large. */\r
1574         if( uxPriority >= configMAX_PRIORITIES )\r
1575         {\r
1576                 uxPriority = configMAX_PRIORITIES - 1;\r
1577         }\r
1578 \r
1579         pxTCB->uxPriority = uxPriority;\r
1580 \r
1581         vListInitialiseItem( &( pxTCB->xGenericListItem ) );\r
1582         vListInitialiseItem( &( pxTCB->xEventListItem ) );\r
1583 \r
1584         /* Set the pxTCB as a link back from the xListItem.  This is so we can get\r
1585         back to the containing TCB from a generic item in a list. */\r
1586         listSET_LIST_ITEM_OWNER( &( pxTCB->xGenericListItem ), pxTCB );\r
1587 \r
1588         /* Event lists are always in priority order. */\r
1589         listSET_LIST_ITEM_VALUE( &( pxTCB->xEventListItem ), configMAX_PRIORITIES - ( portTickType ) uxPriority );\r
1590         listSET_LIST_ITEM_OWNER( &( pxTCB->xEventListItem ), pxTCB );\r
1591 }\r
1592 /*-----------------------------------------------------------*/\r
1593 \r
1594 static void prvInitialiseTaskLists( void )\r
1595 {\r
1596 unsigned portBASE_TYPE uxPriority;\r
1597 \r
1598         for( uxPriority = 0; uxPriority < configMAX_PRIORITIES; uxPriority++ )\r
1599         {\r
1600                 vListInitialise( ( xList * ) &( pxReadyTasksLists[ uxPriority ] ) );\r
1601         }\r
1602 \r
1603         vListInitialise( ( xList * ) &xDelayedTaskList1 );\r
1604         vListInitialise( ( xList * ) &xDelayedTaskList2 );\r
1605         vListInitialise( ( xList * ) &xPendingReadyList );\r
1606 \r
1607         #if ( INCLUDE_vTaskDelete == 1 )\r
1608         {\r
1609                 vListInitialise( ( xList * ) &xTasksWaitingTermination );\r
1610         }\r
1611         #endif\r
1612 \r
1613         #if ( INCLUDE_vTaskSuspend == 1 )\r
1614         {\r
1615                 vListInitialise( ( xList * ) &xSuspendedTaskList );\r
1616         }\r
1617         #endif\r
1618 \r
1619         /* Start with pxDelayedTaskList using list1 and the pxOverflowDelayedTaskList\r
1620         using list2. */\r
1621         pxDelayedTaskList = &xDelayedTaskList1;\r
1622         pxOverflowDelayedTaskList = &xDelayedTaskList2;\r
1623 }\r
1624 /*-----------------------------------------------------------*/\r
1625 \r
1626 static void prvCheckTasksWaitingTermination( void )\r
1627 {                                                       \r
1628         #if ( INCLUDE_vTaskDelete == 1 )\r
1629         {                               \r
1630                 portBASE_TYPE xListIsEmpty;\r
1631 \r
1632                 /* ucTasksDeleted is used to prevent vTaskSuspendAll() being called\r
1633                 too often in the idle task. */\r
1634                 if( uxTasksDeleted > ( unsigned portBASE_TYPE ) 0 )\r
1635                 {\r
1636                         vTaskSuspendAll();\r
1637                                 xListIsEmpty = listLIST_IS_EMPTY( &xTasksWaitingTermination );                          \r
1638                         xTaskResumeAll();\r
1639 \r
1640                         if( !xListIsEmpty )\r
1641                         {\r
1642                                 tskTCB *pxTCB;\r
1643 \r
1644                                 portENTER_CRITICAL();\r
1645                                 {                       \r
1646                                         pxTCB = ( tskTCB * ) listGET_OWNER_OF_HEAD_ENTRY( ( ( xList * ) &xTasksWaitingTermination ) );\r
1647                                         vListRemove( &( pxTCB->xGenericListItem ) );\r
1648                                         --uxCurrentNumberOfTasks;\r
1649                                         --uxTasksDeleted;\r
1650                                 }\r
1651                                 portEXIT_CRITICAL();\r
1652 \r
1653                                 prvDeleteTCB( pxTCB );\r
1654                         }\r
1655                 }\r
1656         }\r
1657         #endif\r
1658 }\r
1659 /*-----------------------------------------------------------*/\r
1660 \r
1661 static tskTCB *prvAllocateTCBAndStack( unsigned portSHORT usStackDepth )\r
1662 {\r
1663 tskTCB *pxNewTCB;\r
1664 \r
1665         /* Allocate space for the TCB.  Where the memory comes from depends on\r
1666         the implementation of the port malloc function. */\r
1667         pxNewTCB = ( tskTCB * ) pvPortMalloc( sizeof( tskTCB ) );\r
1668 \r
1669         if( pxNewTCB != NULL )\r
1670         {\r
1671                 /* Allocate space for the stack used by the task being created.\r
1672                 The base of the stack memory stored in the TCB so the task can\r
1673                 be deleted later if required. */\r
1674                 pxNewTCB->pxStack = ( portSTACK_TYPE * ) pvPortMalloc( ( ( size_t )usStackDepth ) * sizeof( portSTACK_TYPE ) );\r
1675 \r
1676                 if( pxNewTCB->pxStack == NULL )\r
1677                 {\r
1678                         /* Could not allocate the stack.  Delete the allocated TCB. */\r
1679                         vPortFree( pxNewTCB );                  \r
1680                         pxNewTCB = NULL;                        \r
1681                 }               \r
1682                 else\r
1683                 {\r
1684                         /* Just to help debugging. */\r
1685                         memset( pxNewTCB->pxStack, tskSTACK_FILL_BYTE, usStackDepth * sizeof( portSTACK_TYPE ) );\r
1686                 }\r
1687         }\r
1688 \r
1689         return pxNewTCB;\r
1690 }\r
1691 /*-----------------------------------------------------------*/\r
1692 \r
1693 #if ( configUSE_TRACE_FACILITY == 1 )\r
1694 \r
1695         static void prvListTaskWithinSingleList( signed portCHAR *pcWriteBuffer, xList *pxList, signed portCHAR cStatus )\r
1696         {\r
1697         volatile tskTCB *pxNextTCB, *pxFirstTCB;\r
1698         static portCHAR pcStatusString[ 50 ];\r
1699         unsigned portSHORT usStackRemaining;\r
1700 \r
1701                 /* Write the details of all the TCB's in pxList into the buffer. */\r
1702                 listGET_OWNER_OF_NEXT_ENTRY( pxFirstTCB, pxList );\r
1703                 do\r
1704                 {\r
1705                         listGET_OWNER_OF_NEXT_ENTRY( pxNextTCB, pxList );\r
1706                         usStackRemaining = usTaskCheckFreeStackSpace( ( unsigned portCHAR * ) pxNextTCB->pxStack );\r
1707                         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
1708                         strcat( ( portCHAR * ) pcWriteBuffer, ( portCHAR * ) pcStatusString );\r
1709 \r
1710                 } while( pxNextTCB != pxFirstTCB );\r
1711         }\r
1712 \r
1713 #endif\r
1714 /*-----------------------------------------------------------*/\r
1715 \r
1716 #if ( configUSE_TRACE_FACILITY == 1 )\r
1717         unsigned portSHORT usTaskCheckFreeStackSpace( const unsigned portCHAR *pucStackByte )\r
1718         {\r
1719         register unsigned portSHORT usCount = 0;\r
1720 \r
1721                 while( *pucStackByte == tskSTACK_FILL_BYTE )\r
1722                 {\r
1723                         pucStackByte -= portSTACK_GROWTH;\r
1724                         usCount++;\r
1725                 }\r
1726 \r
1727                 usCount /= sizeof( portSTACK_TYPE );\r
1728 \r
1729                 return usCount;\r
1730         }\r
1731 #endif\r
1732 /*-----------------------------------------------------------*/\r
1733 \r
1734 \r
1735 \r
1736 #if ( ( INCLUDE_vTaskDelete == 1 ) || ( INCLUDE_vTaskCleanUpResources == 1 ) )\r
1737 \r
1738         static void prvDeleteTCB( tskTCB *pxTCB )\r
1739         {\r
1740                 /* Free up the memory allocated by the scheduler for the task.  It is up to\r
1741                 the task to free any memory allocated at the application level. */\r
1742                 vPortFree( pxTCB->pxStack );\r
1743                 vPortFree( pxTCB );\r
1744         }\r
1745 \r
1746 #endif\r
1747 \r
1748 \r
1749 /*-----------------------------------------------------------*/\r
1750 \r
1751 #if ( INCLUDE_xTaskGetCurrentTaskHandle == 1 )\r
1752 \r
1753         xTaskHandle xTaskGetCurrentTaskHandle( void )\r
1754         {\r
1755         xTaskHandle xReturn;\r
1756 \r
1757                 portENTER_CRITICAL();\r
1758                 {\r
1759                         xReturn = ( xTaskHandle ) pxCurrentTCB;\r
1760                 }\r
1761                 portEXIT_CRITICAL();\r
1762 \r
1763                 return xReturn;\r
1764         }\r
1765 \r
1766 #endif\r
1767 \r
1768 \r
1769 \r
1770 \r
1771 \r