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