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