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   1 /*\r
   2         FreeRTOS.org V4.7.2 - Copyright (C) 2003-2008 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 \r
  28         Please ensure to read the configuration and relevant port sections of the\r
  29         online documentation.\r
  30 \r
  31         +++ http://www.FreeRTOS.org +++\r
  32         Documentation, latest information, license and contact details.\r
  33 \r
  34         +++ http://www.SafeRTOS.com +++\r
  35         A version that is certified for use in safety critical systems.\r
  36 \r
  37         +++ http://www.OpenRTOS.com +++\r
  38         Commercial support, development, porting, licensing and training services.\r
  39 \r
  40         ***************************************************************************\r
  41 */\r
  42 \r
  43 \r
  44 #include <stdio.h>\r
  45 #include <stdlib.h>\r
  46 #include <string.h>\r
  47 \r
  48 #include "FreeRTOS.h"\r
  49 #include "task.h"\r
  50 \r
  51 /*\r
  52  * Macro to define the amount of stack available to the idle task.\r
  53  */\r
  54 #define tskIDLE_STACK_SIZE      configMINIMAL_STACK_SIZE\r
  55 \r
  56 \r
  57 /*\r
  58  * Default a definitions for backwards compatibility with old\r
  59  * portmacro.h files.\r
  60  */\r
  61 #ifndef configMAX_TASK_NAME_LEN\r
  62         #define configMAX_TASK_NAME_LEN 16\r
  63 #endif\r
  64 \r
  65 #ifndef configIDLE_SHOULD_YIELD\r
  66         #define configIDLE_SHOULD_YIELD         1\r
  67 #endif\r
  68 \r
  69 #if configMAX_TASK_NAME_LEN < 1\r
  70         #undef configMAX_TASK_NAME_LEN\r
  71         #define configMAX_TASK_NAME_LEN 1\r
  72 #endif\r
  73 \r
  74 #ifndef INCLUDE_xTaskResumeFromISR\r
  75         #define INCLUDE_xTaskResumeFromISR 1\r
  76 #endif\r
  77 \r
  78 #ifndef INCLUDE_xTaskGetSchedulerState\r
  79         #define INCLUDE_xTaskGetSchedulerState 0\r
  80 #endif\r
  81 \r
  82 /*\r
  83  * Task control block.  A task control block (TCB) is allocated to each task,\r
  84  * and stores the context of the task.\r
  85  */\r
  86 typedef struct tskTaskControlBlock\r
  87 {\r
  88         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
  89         xListItem                               xGenericListItem;       /*< List item used to place the TCB in ready and blocked queues. */\r
  90         xListItem                               xEventListItem;         /*< List item used to place the TCB in event lists. */\r
  91         unsigned portBASE_TYPE  uxPriority;                     /*< The priority of the task where 0 is the lowest priority. */\r
  92         portSTACK_TYPE                  *pxStack;                       /*< Points to the start of the stack. */\r
  93         signed portCHAR                 pcTaskName[ configMAX_TASK_NAME_LEN ];/*< Descriptive name given to the task when created.  Facilitates debugging only. */\r
  94 \r
  95         #if ( portCRITICAL_NESTING_IN_TCB == 1 )\r
  96                 unsigned portBASE_TYPE uxCriticalNesting;\r
  97         #endif\r
  98 \r
  99         #if ( configUSE_TRACE_FACILITY == 1 )\r
 100                 unsigned portBASE_TYPE  uxTCBNumber;            /*< This is used for tracing the scheduler and making debugging easier only. */\r
 101         #endif  \r
 102                 \r
 103         #if ( configUSE_MUTEXES == 1 )\r
 104                 unsigned portBASE_TYPE uxBasePriority;\r
 105         #endif\r
 106                 \r
 107 } tskTCB;\r
 108 \r
 109 /*lint -e956 */\r
 110 \r
 111 tskTCB * volatile pxCurrentTCB = NULL;                                  \r
 112 \r
 113 /* Lists for ready and blocked tasks. --------------------*/\r
 114 \r
 115 static xList pxReadyTasksLists[ configMAX_PRIORITIES ]; /*< Prioritised ready tasks. */\r
 116 static xList xDelayedTaskList1;                                                 /*< Delayed tasks. */\r
 117 static xList xDelayedTaskList2;                                                 /*< Delayed tasks (two lists are used - one for delays that have overflowed the current tick count. */\r
 118 static xList * volatile pxDelayedTaskList;                              /*< Points to the delayed task list currently being used. */\r
 119 static xList * volatile pxOverflowDelayedTaskList;              /*< Points to the delayed task list currently being used to hold tasks that have overflowed the current tick count. */\r
 120 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
 121 \r
 122 #if ( INCLUDE_vTaskDelete == 1 )\r
 123 \r
 124         static volatile xList xTasksWaitingTermination;         /*< Tasks that have been deleted - but the their memory not yet freed. */\r
 125         static volatile unsigned portBASE_TYPE uxTasksDeleted = ( unsigned portBASE_TYPE ) 0;\r
 126 \r
 127 #endif\r
 128 \r
 129 #if ( INCLUDE_vTaskSuspend == 1 )\r
 130 \r
 131         static xList xSuspendedTaskList;                                        /*< Tasks that are currently suspended. */\r
 132 \r
 133 #endif\r
 134 \r
 135 /* File private variables. --------------------------------*/\r
 136 static volatile unsigned portBASE_TYPE uxCurrentNumberOfTasks   = ( unsigned portBASE_TYPE ) 0;\r
 137 static volatile portTickType xTickCount                                                 = ( portTickType ) 0;\r
 138 static unsigned portBASE_TYPE uxTopUsedPriority                                 = tskIDLE_PRIORITY;\r
 139 static volatile unsigned portBASE_TYPE uxTopReadyPriority               = tskIDLE_PRIORITY;\r
 140 static volatile signed portBASE_TYPE xSchedulerRunning                  = pdFALSE;\r
 141 static volatile unsigned portBASE_TYPE uxSchedulerSuspended             = ( unsigned portBASE_TYPE ) pdFALSE;\r
 142 static volatile unsigned portBASE_TYPE uxMissedTicks                    = ( unsigned portBASE_TYPE ) 0;\r
 143 static volatile portBASE_TYPE xMissedYield                                              = ( portBASE_TYPE ) pdFALSE;\r
 144 static volatile portBASE_TYPE xNumOfOverflows                                   = ( portBASE_TYPE ) 0;\r
 145 /* Debugging and trace facilities private variables and macros. ------------*/\r
 146 \r
 147 /*\r
 148  * The value used to fill the stack of a task when the task is created.  This\r
 149  * is used purely for checking the high water mark for tasks.\r
 150  */\r
 151 #define tskSTACK_FILL_BYTE      ( 0xa5 )\r
 152 \r
 153 /*\r
 154  * Macros used by vListTask to indicate which state a task is in.\r
 155  */\r
 156 #define tskBLOCKED_CHAR         ( ( signed portCHAR ) 'B' )\r
 157 #define tskREADY_CHAR           ( ( signed portCHAR ) 'R' )\r
 158 #define tskDELETED_CHAR         ( ( signed portCHAR ) 'D' )\r
 159 #define tskSUSPENDED_CHAR       ( ( signed portCHAR ) 'S' )\r
 160 \r
 161 /*\r
 162  * Macros and private variables used by the trace facility.\r
 163  */\r
 164 #if ( configUSE_TRACE_FACILITY == 1 )\r
 165 \r
 166         #define tskSIZE_OF_EACH_TRACE_LINE                      ( ( unsigned portLONG ) ( sizeof( unsigned portLONG ) + sizeof( unsigned portLONG ) ) )\r
 167         static volatile signed portCHAR * volatile pcTraceBuffer;\r
 168         static signed portCHAR *pcTraceBufferStart;\r
 169         static signed portCHAR *pcTraceBufferEnd;\r
 170         static signed portBASE_TYPE xTracing = pdFALSE;\r
 171 \r
 172 #endif\r
 173 \r
 174 /*-----------------------------------------------------------*/\r
 175 \r
 176 /*\r
 177  * Macro that writes a trace of scheduler activity to a buffer.  This trace\r
 178  * shows which task is running when and is very useful as a debugging tool.\r
 179  * As this macro is called each context switch it is a good idea to undefine\r
 180  * it if not using the facility.\r
 181  */\r
 182 #if ( configUSE_TRACE_FACILITY == 1 )\r
 183 \r
 184         #define vWriteTraceToBuffer()                                                                                                                                   \\r
 185         {                                                                                                                                                                                               \\r
 186                 if( xTracing )                                                                                                                                                          \\r
 187                 {                                                                                                                                                                                       \\r
 188                         static unsigned portBASE_TYPE uxPreviousTask = 255;                                                                             \\r
 189                                                                                                                                                                                                         \\r
 190                         if( uxPreviousTask != pxCurrentTCB->uxTCBNumber )                                                                               \\r
 191                         {                                                                                                                                                                               \\r
 192                                 if( ( pcTraceBuffer + tskSIZE_OF_EACH_TRACE_LINE ) < pcTraceBufferEnd )                         \\r
 193                                 {                                                                                                                                                                       \\r
 194                                         uxPreviousTask = pxCurrentTCB->uxTCBNumber;                                                                             \\r
 195                                         *( unsigned portLONG * ) pcTraceBuffer = ( unsigned portLONG ) xTickCount;              \\r
 196                                         pcTraceBuffer += sizeof( unsigned portLONG );                                                                   \\r
 197                                         *( unsigned portLONG * ) pcTraceBuffer = ( unsigned portLONG ) uxPreviousTask;  \\r
 198                                         pcTraceBuffer += sizeof( unsigned portLONG );                                                                   \\r
 199                                 }                                                                                                                                                                       \\r
 200                                 else                                                                                                                                                            \\r
 201                                 {                                                                                                                                                                       \\r
 202                                         xTracing = pdFALSE;                                                                                                                             \\r
 203                                 }                                                                                                                                                                       \\r
 204                         }                                                                                                                                                                               \\r
 205                 }                                                                                                                                                                                       \\r
 206         }\r
 207 \r
 208 #else\r
 209 \r
 210         #define vWriteTraceToBuffer()\r
 211 \r
 212 #endif\r
 213 /*-----------------------------------------------------------*/\r
 214 \r
 215 /*\r
 216  * Place the task represented by pxTCB into the appropriate ready queue for\r
 217  * the task.  It is inserted at the end of the list.  One quirk of this is\r
 218  * that if the task being inserted is at the same priority as the currently\r
 219  * executing task, then it will only be rescheduled after the currently\r
 220  * executing task has been rescheduled.\r
 221  */\r
 222 #define prvAddTaskToReadyQueue( pxTCB )                                                                                                                                                 \\r
 223 {                                                                                                                                                                                                                               \\r
 224         if( pxTCB->uxPriority > uxTopReadyPriority )                                                                                                                            \\r
 225         {                                                                                                                                                                                                                       \\r
 226                 uxTopReadyPriority = pxTCB->uxPriority;                                                                                                                                 \\r
 227         }                                                                                                                                                                                                                       \\r
 228         vListInsertEnd( ( xList * ) &( pxReadyTasksLists[ pxTCB->uxPriority ] ), &( pxTCB->xGenericListItem ) );        \\r
 229 }\r
 230 /*-----------------------------------------------------------*/         \r
 231 \r
 232 /*\r
 233  * Macro that looks at the list of tasks that are currently delayed to see if\r
 234  * any require waking.\r
 235  *\r
 236  * Tasks are stored in the queue in the order of their wake time - meaning\r
 237  * once one tasks has been found whose timer has not expired we need not look\r
 238  * any further down the list.\r
 239  */\r
 240 #define prvCheckDelayedTasks()                                                                                                                                                                          \\r
 241 {                                                                                                                                                                                                                                       \\r
 242 register tskTCB *pxTCB;                                                                                                                                                                                         \\r
 243                                                                                                                                                                                                                                         \\r
 244         while( ( pxTCB = ( tskTCB * ) listGET_OWNER_OF_HEAD_ENTRY( pxDelayedTaskList ) ) != NULL )                                              \\r
 245         {                                                                                                                                                                                                                               \\r
 246                 if( xTickCount < listGET_LIST_ITEM_VALUE( &( pxTCB->xGenericListItem ) ) )                                                                      \\r
 247                 {                                                                                                                                                                                                                       \\r
 248                         break;                                                                                                                                                                                                  \\r
 249                 }                                                                                                                                                                                                                       \\r
 250                 vListRemove( &( pxTCB->xGenericListItem ) );                                                                                                                            \\r
 251                 /* Is the task waiting on an event also? */                                                                                                                                     \\r
 252                 if( pxTCB->xEventListItem.pvContainer )                                                                                                                                         \\r
 253                 {                                                                                                                                                                                                                       \\r
 254                         vListRemove( &( pxTCB->xEventListItem ) );                                                                                                                              \\r
 255                 }                                                                                                                                                                                                                       \\r
 256                 prvAddTaskToReadyQueue( pxTCB );                                                                                                                                                        \\r
 257         }                                                                                                                                                                                                                               \\r
 258 }\r
 259 /*-----------------------------------------------------------*/\r
 260 \r
 261 /*\r
 262  * Call the stack overflow hook function if the stack of the task being swapped\r
 263  * out is currently overflowed, or looks like it might have overflowed in the\r
 264  * past.\r
 265  *\r
 266  * Setting configCHECK_FOR_STACK_OVERFLOW to 1 will cause the macro to check\r
 267  * the current stack state only - comparing the current top of stack value to\r
 268  * the stack limit.  Setting configCHECK_FOR_STACK_OVERFLOW to greater than 1\r
 269  * will also cause the last few stack bytes to be checked to ensure the value\r
 270  * to which the bytes were set when the task was created have not been \r
 271  * overwritten.  Note this second test does not guarantee that an overflowed\r
 272  * stack will always be recognised.\r
 273  */\r
 274 \r
 275 #if( configCHECK_FOR_STACK_OVERFLOW == 0 )\r
 276 \r
 277         /* FreeRTOSConfig.h is not set to check for stack overflows. */\r
 278         #define taskCHECK_FOR_STACK_OVERFLOW()\r
 279 \r
 280 #endif /* configCHECK_FOR_STACK_OVERFLOW == 0 */\r
 281 \r
 282 #if( ( configCHECK_FOR_STACK_OVERFLOW > 0 ) && ( portSTACK_GROWTH >= 0 ) )\r
 283 \r
 284         /* This is an invalid setting. */\r
 285         #error configCHECK_FOR_STACK_OVERFLOW can only be set to a non zero value on architectures where the stack grows down from high memory.\r
 286 \r
 287 #endif /* ( configCHECK_FOR_STACK_OVERFLOW > 0 ) && ( portSTACK_GROWTH >= 0 ) */\r
 288 \r
 289 #if( configCHECK_FOR_STACK_OVERFLOW == 1 )\r
 290 \r
 291         /* Only the current stack state is to be checked. */\r
 292         #define taskCHECK_FOR_STACK_OVERFLOW()                                                                                                                          \\r
 293         {                                                                                                                                                                                                       \\r
 294         extern void vApplicationStackOverflowHook( xTaskHandle *pxTask, signed portCHAR *pcTaskName );          \\r
 295                                                                                                                                                                                                                 \\r
 296                 /* Is the currently saved stack pointer within the stack limit? */                                                              \\r
 297                 if( pxCurrentTCB->pxTopOfStack <= pxCurrentTCB->pxStack )                                                                               \\r
 298                 {                                                                                                                                                                                               \\r
 299                         vApplicationStackOverflowHook( ( xTaskHandle ) pxCurrentTCB, pxCurrentTCB->pcTaskName );        \\r
 300                 }                                                                                                                                                                                               \\r
 301         }\r
 302 \r
 303 #endif /* configCHECK_FOR_STACK_OVERFLOW == 1 */\r
 304 \r
 305 #if( configCHECK_FOR_STACK_OVERFLOW > 1 )\r
 306 \r
 307         /* Both the current statck state and the stack fill bytes are to be checked. */\r
 308         #define taskCHECK_FOR_STACK_OVERFLOW()                                                                                                                                                                                                                  \\r
 309         {                                                                                                                                                                                                                                                                                               \\r
 310         extern void vApplicationStackOverflowHook( xTaskHandle *pxTask, signed portCHAR *pcTaskName );                                                                                                  \\r
 311         static const unsigned portCHAR ucExpectedStackBytes[] = {       tskSTACK_FILL_BYTE, tskSTACK_FILL_BYTE, tskSTACK_FILL_BYTE, tskSTACK_FILL_BYTE,         \\r
 312                                                                                                                                 tskSTACK_FILL_BYTE, tskSTACK_FILL_BYTE, tskSTACK_FILL_BYTE, tskSTACK_FILL_BYTE,         \\r
 313                                                                                                                                 tskSTACK_FILL_BYTE, tskSTACK_FILL_BYTE, tskSTACK_FILL_BYTE, tskSTACK_FILL_BYTE,         \\r
 314                                                                                                                                 tskSTACK_FILL_BYTE, tskSTACK_FILL_BYTE, tskSTACK_FILL_BYTE, tskSTACK_FILL_BYTE,         \\r
 315                                                                                                                                 tskSTACK_FILL_BYTE, tskSTACK_FILL_BYTE, tskSTACK_FILL_BYTE, tskSTACK_FILL_BYTE };       \\r
 316                                                                                                                                                                                                                                                                                                         \\r
 317                 /* Is the currently saved stack pointer within the stack limit? */                                                                                                                                                      \\r
 318                 if( pxCurrentTCB->pxTopOfStack <= pxCurrentTCB->pxStack )                                                                                                                                                                       \\r
 319                 {                                                                                                                                                                                                                                                                                       \\r
 320                         vApplicationStackOverflowHook( ( xTaskHandle ) pxCurrentTCB, pxCurrentTCB->pcTaskName );                                                                                                \\r
 321                 }                                                                                                                                                                                                                                                                                       \\r
 322                                                                                                                                                                                                                                                                                                         \\r
 323                 /* Has the extremity of the task stack ever been written over? */                                                                                                                                                       \\r
 324                 if( memcmp( ( void * ) pxCurrentTCB->pxStack, ( void * ) ucExpectedStackBytes, sizeof( ucExpectedStackBytes ) ) != 0 )                                          \\r
 325                 {                                                                                                                                                                                                                                                                                       \\r
 326                         vApplicationStackOverflowHook( ( xTaskHandle ) pxCurrentTCB, pxCurrentTCB->pcTaskName );                                                                                                                                \\r
 327                 }                                                                                                                                                                                                                                                                                       \\r
 328         }\r
 329 \r
 330 #endif /* #if( configCHECK_FOR_STACK_OVERFLOW > 1 ) */\r
 331 \r
 332 /*-----------------------------------------------------------*/\r
 333 \r
 334 /*\r
 335  * Several functions take an xTaskHandle parameter that can optionally be NULL,\r
 336  * where NULL is used to indicate that the handle of the currently executing\r
 337  * task should be used in place of the parameter.  This macro simply checks to\r
 338  * see if the parameter is NULL and returns a pointer to the appropriate TCB.\r
 339  */\r
 340 #define prvGetTCBFromHandle( pxHandle ) ( ( pxHandle == NULL ) ? ( tskTCB * ) pxCurrentTCB : ( tskTCB * ) pxHandle )\r
 341 \r
 342 \r
 343 /* File private functions. --------------------------------*/\r
 344 \r
 345 /*\r
 346  * Utility to ready a TCB for a given task.  Mainly just copies the parameters\r
 347  * into the TCB structure.\r
 348  */\r
 349 static void prvInitialiseTCBVariables( tskTCB *pxTCB, const signed portCHAR * const pcName, unsigned portBASE_TYPE uxPriority );\r
 350 \r
 351 /*\r
 352  * Utility to ready all the lists used by the scheduler.  This is called\r
 353  * automatically upon the creation of the first task.\r
 354  */\r
 355 static void prvInitialiseTaskLists( void );\r
 356 \r
 357 /*\r
 358  * The idle task, which as all tasks is implemented as a never ending loop.\r
 359  * The idle task is automatically created and added to the ready lists upon\r
 360  * creation of the first user task.\r
 361  *\r
 362  * The portTASK_FUNCTION_PROTO() macro is used to allow port/compiler specific\r
 363  * language extensions.  The equivalent prototype for this function is:\r
 364  *\r
 365  * void prvIdleTask( void *pvParameters );\r
 366  *\r
 367  */\r
 368 static portTASK_FUNCTION_PROTO( prvIdleTask, pvParameters );\r
 369 \r
 370 /*\r
 371  * Utility to free all memory allocated by the scheduler to hold a TCB,\r
 372  * including the stack pointed to by the TCB.\r
 373  *\r
 374  * This does not free memory allocated by the task itself (i.e. memory\r
 375  * allocated by calls to pvPortMalloc from within the tasks application code).\r
 376  */\r
 377 #if ( ( INCLUDE_vTaskDelete == 1 ) || ( INCLUDE_vTaskCleanUpResources == 1 ) )\r
 378         static void prvDeleteTCB( tskTCB *pxTCB );\r
 379 #endif\r
 380 \r
 381 /*\r
 382  * Used only by the idle task.  This checks to see if anything has been placed\r
 383  * in the list of tasks waiting to be deleted.  If so the task is cleaned up\r
 384  * and its TCB deleted.\r
 385  */\r
 386 static void prvCheckTasksWaitingTermination( void );\r
 387 \r
 388 /*\r
 389  * Allocates memory from the heap for a TCB and associated stack.  Checks the\r
 390  * allocation was successful.\r
 391  */\r
 392 static tskTCB *prvAllocateTCBAndStack( unsigned portSHORT usStackDepth );\r
 393 \r
 394 /*\r
 395  * Called from vTaskList.  vListTasks details all the tasks currently under\r
 396  * control of the scheduler.  The tasks may be in one of a number of lists.\r
 397  * prvListTaskWithinSingleList accepts a list and details the tasks from\r
 398  * within just that list.\r
 399  *\r
 400  * THIS FUNCTION IS INTENDED FOR DEBUGGING ONLY, AND SHOULD NOT BE CALLED FROM\r
 401  * NORMAL APPLICATION CODE.\r
 402  */\r
 403 #if ( configUSE_TRACE_FACILITY == 1 )\r
 404 \r
 405         static void prvListTaskWithinSingleList( const signed portCHAR *pcWriteBuffer, xList *pxList, signed portCHAR cStatus );\r
 406 \r
 407 #endif\r
 408 \r
 409 /*\r
 410  * When a task is created, the stack of the task is filled with a known value.\r
 411  * This function determines the 'high water mark' of the task stack by\r
 412  * determining how much of the stack remains at the original preset value.\r
 413  */\r
 414 #if ( ( configUSE_TRACE_FACILITY == 1 ) || ( INCLUDE_uxTaskGetStackHighWaterMark == 1 ) )\r
 415 \r
 416         unsigned portSHORT usTaskCheckFreeStackSpace( const unsigned portCHAR * pucStackByte );\r
 417 \r
 418 #endif\r
 419 \r
 420 /*\r
 421  * Checks that a task being resumed (unsuspended) is actually in the Suspended\r
 422  * state.\r
 423  */\r
 424 #if ( INCLUDE_vTaskSuspend == 1 )\r
 425 \r
 426         static portBASE_TYPE prvIsTaskSuspended( const tskTCB * const pxTCB );  \r
 427 \r
 428 #endif\r
 429 \r
 430 /*lint +e956 */\r
 431 \r
 432 \r
 433 \r
 434 /*-----------------------------------------------------------\r
 435  * TASK CREATION API documented in task.h\r
 436  *----------------------------------------------------------*/\r
 437 \r
 438 signed portBASE_TYPE xTaskCreate( pdTASK_CODE pvTaskCode, const signed portCHAR * const pcName, unsigned portSHORT usStackDepth, void *pvParameters, unsigned portBASE_TYPE uxPriority, xTaskHandle *pxCreatedTask )\r
 439 {\r
 440 signed portBASE_TYPE xReturn;\r
 441 tskTCB * pxNewTCB;\r
 442 #if ( configUSE_TRACE_FACILITY == 1 )\r
 443         static unsigned portBASE_TYPE uxTaskNumber = 0; /*lint !e956 Static is deliberate - this is guarded before use. */\r
 444 #endif\r
 445 \r
 446         /* Allocate the memory required by the TCB and stack for the new task.\r
 447         checking that the allocation was successful. */\r
 448         pxNewTCB = prvAllocateTCBAndStack( usStackDepth );\r
 449 \r
 450         if( pxNewTCB != NULL )\r
 451         {               \r
 452                 portSTACK_TYPE *pxTopOfStack;\r
 453 \r
 454                 /* Setup the newly allocated TCB with the initial state of the task. */\r
 455                 prvInitialiseTCBVariables( pxNewTCB, pcName, uxPriority );\r
 456 \r
 457                 /* Calculate the top of stack address.  This depends on whether the\r
 458                 stack grows from high memory to low (as per the 80x86) or visa versa.\r
 459                 portSTACK_GROWTH is used to make the result positive or negative as\r
 460                 required by the port. */\r
 461                 #if portSTACK_GROWTH < 0\r
 462                 {\r
 463                         pxTopOfStack = pxNewTCB->pxStack + ( usStackDepth - 1 );\r
 464                 }\r
 465                 #else\r
 466                 {\r
 467                         pxTopOfStack = pxNewTCB->pxStack;       \r
 468                 }\r
 469                 #endif\r
 470 \r
 471                 /* Initialize the TCB stack to look as if the task was already running,\r
 472                 but had been interrupted by the scheduler.  The return address is set\r
 473                 to the start of the task function. Once the stack has been initialised\r
 474                 the     top of stack variable is updated. */\r
 475                 pxNewTCB->pxTopOfStack = pxPortInitialiseStack( pxTopOfStack, pvTaskCode, pvParameters );\r
 476 \r
 477                 /* We are going to manipulate the task queues to add this task to a\r
 478                 ready list, so must make sure no interrupts occur. */\r
 479                 portENTER_CRITICAL();\r
 480                 {\r
 481                         uxCurrentNumberOfTasks++;\r
 482                         if( uxCurrentNumberOfTasks == ( unsigned portBASE_TYPE ) 1 )\r
 483                         {\r
 484                                 /* As this is the first task it must also be the current task. */\r
 485                                 pxCurrentTCB =  pxNewTCB;\r
 486 \r
 487                                 /* This is the first task to be created so do the preliminary\r
 488                                 initialisation required.  We will not recover if this call\r
 489                                 fails, but we will report the failure. */\r
 490                                 prvInitialiseTaskLists();\r
 491                         }\r
 492                         else\r
 493                         {       \r
 494                                 /* If the scheduler is not already running, make this task the\r
 495                                 current task if it is the highest priority task to be created\r
 496                                 so far. */\r
 497                                 if( xSchedulerRunning == pdFALSE )\r
 498                                 {\r
 499                                         if( pxCurrentTCB->uxPriority <= uxPriority )\r
 500                                         {\r
 501                                                 pxCurrentTCB = pxNewTCB;        \r
 502                                         }\r
 503                                 }\r
 504                         }                               \r
 505 \r
 506                         /* Remember the top priority to make context switching faster.  Use\r
 507                         the priority in pxNewTCB as this has been capped to a valid value. */\r
 508                         if( pxNewTCB->uxPriority > uxTopUsedPriority )\r
 509                         {\r
 510                                 uxTopUsedPriority = pxNewTCB->uxPriority;\r
 511                         }\r
 512 \r
 513                         #if ( configUSE_TRACE_FACILITY == 1 )\r
 514                         {\r
 515                                 /* Add a counter into the TCB for tracing only. */\r
 516                                 pxNewTCB->uxTCBNumber = uxTaskNumber;\r
 517                                 uxTaskNumber++;\r
 518                         }\r
 519                         #endif\r
 520 \r
 521                         prvAddTaskToReadyQueue( pxNewTCB );\r
 522 \r
 523                         xReturn = pdPASS;\r
 524                         traceTASK_CREATE( pxNewTCB );\r
 525                 }\r
 526                 portEXIT_CRITICAL();\r
 527         }\r
 528         else\r
 529         {\r
 530                 xReturn = errCOULD_NOT_ALLOCATE_REQUIRED_MEMORY;\r
 531                 traceTASK_CREATE_FAILED( pxNewTCB );\r
 532         }\r
 533 \r
 534         if( xReturn == pdPASS )\r
 535         {\r
 536                 if( ( void * ) pxCreatedTask != NULL )\r
 537                 {\r
 538                         /* Pass the TCB out - in an anonymous way.  The calling function/\r
 539                         task can use this as a handle to delete the task later if\r
 540                         required.*/\r
 541                         *pxCreatedTask = ( xTaskHandle ) pxNewTCB;\r
 542                 }\r
 543 \r
 544                 if( xSchedulerRunning != pdFALSE )\r
 545                 {\r
 546                         /* If the created task is of a higher priority than the current task\r
 547                         then it should run now. */\r
 548                         if( pxCurrentTCB->uxPriority < uxPriority )\r
 549                         {\r
 550                                 taskYIELD();\r
 551                         }\r
 552                 }\r
 553         }\r
 554 \r
 555         return xReturn;\r
 556 }\r
 557 /*-----------------------------------------------------------*/\r
 558 \r
 559 #if ( INCLUDE_vTaskDelete == 1 )\r
 560 \r
 561         void vTaskDelete( xTaskHandle pxTaskToDelete )\r
 562         {\r
 563         tskTCB *pxTCB;\r
 564 \r
 565                 taskENTER_CRITICAL();\r
 566                 {\r
 567                         /* Ensure a yield is performed if the current task is being\r
 568                         deleted. */\r
 569                         if( pxTaskToDelete == pxCurrentTCB )\r
 570                         {\r
 571                                 pxTaskToDelete = NULL;\r
 572                         }\r
 573 \r
 574                         /* If null is passed in here then we are deleting ourselves. */\r
 575                         pxTCB = prvGetTCBFromHandle( pxTaskToDelete );\r
 576 \r
 577                         traceTASK_DELETE( pxTCB );\r
 578 \r
 579                         /* Remove task from the ready list and place in the     termination list.\r
 580                         This will stop the task from be scheduled.  The idle task will check\r
 581                         the termination list and free up any memory allocated by the\r
 582                         scheduler for the TCB and stack. */\r
 583                         vListRemove( &( pxTCB->xGenericListItem ) );\r
 584 \r
 585                         /* Is the task waiting on an event also? */                                                                                             \r
 586                         if( pxTCB->xEventListItem.pvContainer )\r
 587                         {\r
 588                                 vListRemove( &( pxTCB->xEventListItem ) );\r
 589                         }\r
 590 \r
 591                         vListInsertEnd( ( xList * ) &xTasksWaitingTermination, &( pxTCB->xGenericListItem ) );\r
 592 \r
 593                         /* Increment the ucTasksDeleted variable so the idle task knows\r
 594                         there is a task that has been deleted and that it should therefore\r
 595                         check the xTasksWaitingTermination list. */\r
 596                         ++uxTasksDeleted;\r
 597                 }\r
 598                 taskEXIT_CRITICAL();\r
 599 \r
 600                 /* Force a reschedule if we have just deleted the current task. */\r
 601                 if( xSchedulerRunning != pdFALSE )\r
 602                 {\r
 603                         if( ( void * ) pxTaskToDelete == NULL )\r
 604                         {\r
 605                                 taskYIELD();\r
 606                         }\r
 607                 }\r
 608         }\r
 609 \r
 610 #endif\r
 611 \r
 612 \r
 613 \r
 614 \r
 615 \r
 616 \r
 617 /*-----------------------------------------------------------\r
 618  * TASK CONTROL API documented in task.h\r
 619  *----------------------------------------------------------*/\r
 620 \r
 621 #if ( INCLUDE_vTaskDelayUntil == 1 )\r
 622 \r
 623         void vTaskDelayUntil( portTickType * const pxPreviousWakeTime, portTickType xTimeIncrement )\r
 624         {\r
 625         portTickType xTimeToWake;\r
 626         portBASE_TYPE xAlreadyYielded, xShouldDelay = pdFALSE;\r
 627 \r
 628                 vTaskSuspendAll();\r
 629                 {\r
 630                         /* Generate the tick time at which the task wants to wake. */\r
 631                         xTimeToWake = *pxPreviousWakeTime + xTimeIncrement;\r
 632 \r
 633                         if( xTickCount < *pxPreviousWakeTime )\r
 634                         {\r
 635                                 /* The tick count has overflowed since this function was\r
 636                                 lasted called.  In this case the only time we should ever\r
 637                                 actually delay is if the wake time has also     overflowed,\r
 638                                 and the wake time is greater than the tick time.  When this\r
 639                                 is the case it is as if neither time had overflowed. */\r
 640                                 if( ( xTimeToWake < *pxPreviousWakeTime ) && ( xTimeToWake > xTickCount ) )\r
 641                                 {\r
 642                                         xShouldDelay = pdTRUE;\r
 643                                 }\r
 644                         }\r
 645                         else\r
 646                         {\r
 647                                 /* The tick time has not overflowed.  In this case we will\r
 648                                 delay if either the wake time has overflowed, and/or the\r
 649                                 tick time is less than the wake time. */\r
 650                                 if( ( xTimeToWake < *pxPreviousWakeTime ) || ( xTimeToWake > xTickCount ) )\r
 651                                 {\r
 652                                         xShouldDelay = pdTRUE;\r
 653                                 }\r
 654                         }\r
 655 \r
 656                         /* Update the wake time ready for the next call. */\r
 657                         *pxPreviousWakeTime = xTimeToWake;\r
 658 \r
 659                         if( xShouldDelay )\r
 660                         {\r
 661                                 traceTASK_DELAY_UNTIL();\r
 662 \r
 663                                 /* We must remove ourselves from the ready list before adding\r
 664                                 ourselves to the blocked list as the same list item is used for\r
 665                                 both lists. */\r
 666                                 vListRemove( ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );\r
 667 \r
 668                                 /* The list item will be inserted in wake time order. */\r
 669                                 listSET_LIST_ITEM_VALUE( &( pxCurrentTCB->xGenericListItem ), xTimeToWake );\r
 670 \r
 671                                 if( xTimeToWake < xTickCount )\r
 672                                 {\r
 673                                         /* Wake time has overflowed.  Place this item in the\r
 674                                         overflow list. */\r
 675                                         vListInsert( ( xList * ) pxOverflowDelayedTaskList, ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );\r
 676                                 }\r
 677                                 else\r
 678                                 {\r
 679                                         /* The wake time has not overflowed, so we can use the\r
 680                                         current block list. */\r
 681                                         vListInsert( ( xList * ) pxDelayedTaskList, ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );\r
 682                                 }\r
 683                         }\r
 684                 }\r
 685                 xAlreadyYielded = xTaskResumeAll();\r
 686 \r
 687                 /* Force a reschedule if xTaskResumeAll has not already done so, we may\r
 688                 have put ourselves to sleep. */\r
 689                 if( !xAlreadyYielded )\r
 690                 {\r
 691                         taskYIELD();\r
 692                 }\r
 693         }       \r
 694         \r
 695 #endif\r
 696 /*-----------------------------------------------------------*/\r
 697 \r
 698 #if ( INCLUDE_vTaskDelay == 1 )\r
 699 \r
 700         void vTaskDelay( portTickType xTicksToDelay )\r
 701         {\r
 702         portTickType xTimeToWake;\r
 703         signed portBASE_TYPE xAlreadyYielded = pdFALSE;\r
 704 \r
 705                 /* A delay time of zero just forces a reschedule. */\r
 706                 if( xTicksToDelay > ( portTickType ) 0 )\r
 707                 {\r
 708                         vTaskSuspendAll();\r
 709                         {\r
 710                                 traceTASK_DELAY();\r
 711 \r
 712                                 /* A task that is removed from the event list while the\r
 713                                 scheduler is suspended will not get placed in the ready\r
 714                                 list or removed from the blocked list until the scheduler\r
 715                                 is resumed.\r
 716                                 \r
 717                                 This task cannot be in an event list as it is the currently\r
 718                                 executing task. */\r
 719 \r
 720                                 /* Calculate the time to wake - this may overflow but this is\r
 721                                 not a problem. */\r
 722                                 xTimeToWake = xTickCount + xTicksToDelay;\r
 723 \r
 724                                 /* We must remove ourselves from the ready list before adding\r
 725                                 ourselves to the blocked list as the same list item is used for\r
 726                                 both lists. */\r
 727                                 vListRemove( ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );\r
 728 \r
 729                                 /* The list item will be inserted in wake time order. */\r
 730                                 listSET_LIST_ITEM_VALUE( &( pxCurrentTCB->xGenericListItem ), xTimeToWake );\r
 731 \r
 732                                 if( xTimeToWake < xTickCount )\r
 733                                 {\r
 734                                         /* Wake time has overflowed.  Place this item in the\r
 735                                         overflow list. */\r
 736                                         vListInsert( ( xList * ) pxOverflowDelayedTaskList, ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );\r
 737                                 }\r
 738                                 else\r
 739                                 {\r
 740                                         /* The wake time has not overflowed, so we can use the\r
 741                                         current block list. */\r
 742                                         vListInsert( ( xList * ) pxDelayedTaskList, ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );\r
 743                                 }\r
 744                         }\r
 745                         xAlreadyYielded = xTaskResumeAll();\r
 746                 }\r
 747                 \r
 748                 /* Force a reschedule if xTaskResumeAll has not already done so, we may\r
 749                 have put ourselves to sleep. */\r
 750                 if( !xAlreadyYielded )\r
 751                 {\r
 752                         taskYIELD();\r
 753                 }\r
 754         }\r
 755         \r
 756 #endif\r
 757 /*-----------------------------------------------------------*/\r
 758 \r
 759 #if ( INCLUDE_uxTaskPriorityGet == 1 )\r
 760 \r
 761         unsigned portBASE_TYPE uxTaskPriorityGet( xTaskHandle pxTask )\r
 762         {\r
 763         tskTCB *pxTCB;\r
 764         unsigned portBASE_TYPE uxReturn;\r
 765 \r
 766                 taskENTER_CRITICAL();\r
 767                 {\r
 768                         /* If null is passed in here then we are changing the\r
 769                         priority of the calling function. */\r
 770                         pxTCB = prvGetTCBFromHandle( pxTask );\r
 771                         uxReturn = pxTCB->uxPriority;\r
 772                 }\r
 773                 taskEXIT_CRITICAL();\r
 774 \r
 775                 return uxReturn;\r
 776         }\r
 777 \r
 778 #endif\r
 779 /*-----------------------------------------------------------*/\r
 780 \r
 781 #if ( INCLUDE_vTaskPrioritySet == 1 )\r
 782 \r
 783         void vTaskPrioritySet( xTaskHandle pxTask, unsigned portBASE_TYPE uxNewPriority )\r
 784         {\r
 785         tskTCB *pxTCB;\r
 786         unsigned portBASE_TYPE uxCurrentPriority, xYieldRequired = pdFALSE;\r
 787 \r
 788                 /* Ensure the new priority is valid. */\r
 789                 if( uxNewPriority >= configMAX_PRIORITIES )\r
 790                 {\r
 791                         uxNewPriority = configMAX_PRIORITIES - 1;\r
 792                 }\r
 793 \r
 794                 taskENTER_CRITICAL();\r
 795                 {\r
 796                         /* If null is passed in here then we are changing the\r
 797                         priority of the calling function. */\r
 798                         pxTCB = prvGetTCBFromHandle( pxTask );\r
 799                         \r
 800                         traceTASK_PRIORITY_SET( pxTask, uxNewPriority );\r
 801 \r
 802                         #if ( configUSE_MUTEXES == 1 )\r
 803                         {\r
 804                                 uxCurrentPriority = pxTCB->uxBasePriority;\r
 805                         }\r
 806                         #else\r
 807                         {\r
 808                                 uxCurrentPriority = pxTCB->uxPriority;\r
 809                         }\r
 810                         #endif\r
 811 \r
 812                         if( uxCurrentPriority != uxNewPriority )\r
 813                         {\r
 814                                 /* The priority change may have readied a task of higher\r
 815                                 priority than the calling task. */\r
 816                                 if( uxNewPriority > uxCurrentPriority )\r
 817                                 {\r
 818                                         if( pxTask != NULL )\r
 819                                         {\r
 820                                                 /* The priority of another task is being raised.  If we\r
 821                                                 were raising the priority of the currently running task\r
 822                                                 there would be no need to switch as it must have already\r
 823                                                 been the highest priority task. */\r
 824                                                 xYieldRequired = pdTRUE;\r
 825                                         }\r
 826                                 }\r
 827                                 else if( pxTask == NULL )\r
 828                                 {\r
 829                                         /* Setting our own priority down means there may now be another\r
 830                                         task of higher priority that is ready to execute. */\r
 831                                         xYieldRequired = pdTRUE;\r
 832                                 }\r
 833                         \r
 834                                 \r
 835 \r
 836                                 #if ( configUSE_MUTEXES == 1 )\r
 837                                 {\r
 838                                         /* Only change the priority being used if the task is not\r
 839                                         currently using an inherited priority. */\r
 840                                         if( pxTCB->uxBasePriority == pxTCB->uxPriority )\r
 841                                         {\r
 842                                                 pxTCB->uxPriority = uxNewPriority;\r
 843                                         }\r
 844                                         \r
 845                                         /* The base priority gets set whatever. */\r
 846                                         pxTCB->uxBasePriority = uxNewPriority;                                  \r
 847                                 }\r
 848                                 #else\r
 849                                 {\r
 850                                         pxTCB->uxPriority = uxNewPriority;\r
 851                                 }\r
 852                                 #endif\r
 853 \r
 854                                 listSET_LIST_ITEM_VALUE( &( pxTCB->xEventListItem ), ( configMAX_PRIORITIES - ( portTickType ) uxNewPriority ) );\r
 855 \r
 856                                 /* If the task is in the blocked or suspended list we need do\r
 857                                 nothing more than change it's priority variable. However, if\r
 858                                 the task is in a ready list it needs to be removed and placed\r
 859                                 in the queue appropriate to its new priority. */\r
 860                                 if( listIS_CONTAINED_WITHIN( &( pxReadyTasksLists[ uxCurrentPriority ] ), &( pxTCB->xGenericListItem ) ) )\r
 861                                 {\r
 862                                         /* The task is currently in its ready list - remove before adding\r
 863                                         it to it's new ready list.  As we are in a critical section we\r
 864                                         can do this even if the scheduler is suspended. */\r
 865                                         vListRemove( &( pxTCB->xGenericListItem ) );\r
 866                                         prvAddTaskToReadyQueue( pxTCB );\r
 867                                 }                       \r
 868                                 \r
 869                                 if( xYieldRequired == pdTRUE )\r
 870                                 {\r
 871                                         taskYIELD();\r
 872                                 }                               \r
 873                         }\r
 874                 }\r
 875                 taskEXIT_CRITICAL();\r
 876         }\r
 877 \r
 878 #endif\r
 879 /*-----------------------------------------------------------*/\r
 880 \r
 881 #if ( INCLUDE_vTaskSuspend == 1 )\r
 882 \r
 883         void vTaskSuspend( xTaskHandle pxTaskToSuspend )\r
 884         {\r
 885         tskTCB *pxTCB;\r
 886 \r
 887                 taskENTER_CRITICAL();\r
 888                 {\r
 889                         /* Ensure a yield is performed if the current task is being\r
 890                         suspended. */\r
 891                         if( pxTaskToSuspend == pxCurrentTCB )\r
 892                         {\r
 893                                 pxTaskToSuspend = NULL;\r
 894                         }\r
 895 \r
 896                         /* If null is passed in here then we are suspending ourselves. */\r
 897                         pxTCB = prvGetTCBFromHandle( pxTaskToSuspend );\r
 898 \r
 899                         traceTASK_SUSPEND( pxTaskToSuspend );\r
 900 \r
 901                         /* Remove task from the ready/delayed list and place in the     suspended list. */\r
 902                         vListRemove( &( pxTCB->xGenericListItem ) );\r
 903 \r
 904                         /* Is the task waiting on an event also? */                                                                                             \r
 905                         if( pxTCB->xEventListItem.pvContainer )\r
 906                         {\r
 907                                 vListRemove( &( pxTCB->xEventListItem ) );\r
 908                         }\r
 909 \r
 910                         vListInsertEnd( ( xList * ) &xSuspendedTaskList, &( pxTCB->xGenericListItem ) );\r
 911                 }\r
 912                 taskEXIT_CRITICAL();\r
 913 \r
 914                 /* We may have just suspended the current task. */\r
 915                 if( ( void * ) pxTaskToSuspend == NULL )\r
 916                 {\r
 917                         taskYIELD();\r
 918                 }\r
 919         }\r
 920 \r
 921 #endif\r
 922 /*-----------------------------------------------------------*/\r
 923 \r
 924 #if ( INCLUDE_vTaskSuspend == 1 )\r
 925 \r
 926         static portBASE_TYPE prvIsTaskSuspended( const tskTCB * const pxTCB )\r
 927         {\r
 928         portBASE_TYPE xReturn = pdFALSE;\r
 929 \r
 930                 /* Is the task we are attempting to resume actually in the\r
 931                 suspended list? */\r
 932                 if( listIS_CONTAINED_WITHIN( &xSuspendedTaskList, &( pxTCB->xGenericListItem ) ) != pdFALSE )\r
 933                 {\r
 934                         /* Has the task already been resumed from within an ISR? */\r
 935                         if( listIS_CONTAINED_WITHIN( &xPendingReadyList, &( pxTCB->xEventListItem ) ) != pdTRUE )\r
 936                         {                       \r
 937                                 /* Is it in the suspended list because it is in the\r
 938                                 Suspended state?  It is possible to be in the suspended\r
 939                                 list because it is blocked on a task with no timeout\r
 940                                 specified. */\r
 941                                 if( listIS_CONTAINED_WITHIN( NULL, &( pxTCB->xEventListItem ) ) == pdTRUE )\r
 942                                 {\r
 943                                         xReturn = pdTRUE;\r
 944                                 }\r
 945                         }\r
 946                 }\r
 947 \r
 948                 return xReturn;\r
 949         }\r
 950 \r
 951 #endif\r
 952 /*-----------------------------------------------------------*/\r
 953 \r
 954 #if ( INCLUDE_vTaskSuspend == 1 )\r
 955 \r
 956         void vTaskResume( xTaskHandle pxTaskToResume )\r
 957         {\r
 958         tskTCB *pxTCB;\r
 959 \r
 960                 /* Remove the task from whichever list it is currently in, and place\r
 961                 it in the ready list. */\r
 962                 pxTCB = ( tskTCB * ) pxTaskToResume;\r
 963 \r
 964                 /* The parameter cannot be NULL as it is impossible to resume the\r
 965                 currently executing task. */\r
 966                 if( pxTCB != NULL )\r
 967                 {\r
 968                         taskENTER_CRITICAL();\r
 969                         {\r
 970                                 if( prvIsTaskSuspended( pxTCB ) == pdTRUE )\r
 971                                 {\r
 972                                         traceTASK_RESUME( pxTCB );\r
 973 \r
 974                                         /* As we are in a critical section we can access the ready\r
 975                                         lists even if the scheduler is suspended. */\r
 976                                         vListRemove(  &( pxTCB->xGenericListItem ) );\r
 977                                         prvAddTaskToReadyQueue( pxTCB );\r
 978 \r
 979                                         /* We may have just resumed a higher priority task. */\r
 980                                         if( pxTCB->uxPriority >= pxCurrentTCB->uxPriority )\r
 981                                         {\r
 982                                                 /* This yield may not cause the task just resumed to run, but\r
 983                                                 will leave the lists in the correct state for the next yield. */\r
 984                                                 taskYIELD();\r
 985                                         }\r
 986                                 }\r
 987                         }\r
 988                         taskEXIT_CRITICAL();\r
 989                 }\r
 990         }\r
 991 \r
 992 #endif\r
 993 \r
 994 /*-----------------------------------------------------------*/\r
 995 \r
 996 #if ( ( INCLUDE_xTaskResumeFromISR == 1 ) && ( INCLUDE_vTaskSuspend == 1 ) )\r
 997 \r
 998         portBASE_TYPE xTaskResumeFromISR( xTaskHandle pxTaskToResume )\r
 999         {\r
1000         portBASE_TYPE xYieldRequired = pdFALSE;\r
1001         tskTCB *pxTCB;\r
1002 \r
1003                 pxTCB = ( tskTCB * ) pxTaskToResume;\r
1004 \r
1005                 if( prvIsTaskSuspended( pxTCB ) == pdTRUE )\r
1006                 {\r
1007                         traceTASK_RESUME_FROM_ISR( pxTCB );\r
1008 \r
1009                         if( uxSchedulerSuspended == ( unsigned portBASE_TYPE ) pdFALSE )\r
1010                         {\r
1011                                 xYieldRequired = ( pxTCB->uxPriority >= pxCurrentTCB->uxPriority );\r
1012                                 vListRemove(  &( pxTCB->xGenericListItem ) );   \r
1013                                 prvAddTaskToReadyQueue( pxTCB );\r
1014                         }\r
1015                         else\r
1016                         {\r
1017                                 /* We cannot access the delayed or ready lists, so will hold this\r
1018                                 task pending until the scheduler is resumed, at which point a\r
1019                                 yield will be performed if necessary. */\r
1020                                 vListInsertEnd( ( xList * ) &( xPendingReadyList ), &( pxTCB->xEventListItem ) );\r
1021                         }\r
1022                 }\r
1023 \r
1024                 return xYieldRequired;\r
1025         }\r
1026 \r
1027 #endif\r
1028 \r
1029 \r
1030 \r
1031 \r
1032 /*-----------------------------------------------------------\r
1033  * PUBLIC SCHEDULER CONTROL documented in task.h\r
1034  *----------------------------------------------------------*/\r
1035 \r
1036 \r
1037 void vTaskStartScheduler( void )\r
1038 {\r
1039 portBASE_TYPE xReturn;\r
1040 \r
1041         /* Add the idle task at the lowest priority. */\r
1042         xReturn = xTaskCreate( prvIdleTask, ( signed portCHAR * ) "IDLE", tskIDLE_STACK_SIZE, ( void * ) NULL, tskIDLE_PRIORITY, ( xTaskHandle * ) NULL );\r
1043 \r
1044         if( xReturn == pdPASS )\r
1045         {\r
1046                 /* Interrupts are turned off here, to ensure a tick does not occur\r
1047                 before or during the call to xPortStartScheduler().  The stacks of\r
1048                 the created tasks contain a status word with interrupts switched on\r
1049                 so interrupts will automatically get re-enabled when the first task\r
1050                 starts to run.\r
1051                 \r
1052                 STEPPING THROUGH HERE USING A DEBUGGER CAN CAUSE BIG PROBLEMS IF THE\r
1053                 DEBUGGER ALLOWS INTERRUPTS TO BE PROCESSED. */\r
1054                 portDISABLE_INTERRUPTS();\r
1055 \r
1056                 xSchedulerRunning = pdTRUE;\r
1057                 xTickCount = ( portTickType ) 0;\r
1058 \r
1059                 /* Setting up the timer tick is hardware specific and thus in the\r
1060                 portable interface. */\r
1061                 if( xPortStartScheduler() )\r
1062                 {\r
1063                         /* Should not reach here as if the scheduler is running the\r
1064                         function will not return. */\r
1065                 }\r
1066                 else\r
1067                 {\r
1068                         /* Should only reach here if a task calls xTaskEndScheduler(). */\r
1069                 }\r
1070         }\r
1071 }\r
1072 /*-----------------------------------------------------------*/\r
1073 \r
1074 void vTaskEndScheduler( void )\r
1075 {\r
1076         /* Stop the scheduler interrupts and call the portable scheduler end\r
1077         routine so the original ISRs can be restored if necessary.  The port\r
1078         layer must ensure interrupts enable     bit is left in the correct state. */\r
1079         portDISABLE_INTERRUPTS();\r
1080         xSchedulerRunning = pdFALSE;\r
1081         vPortEndScheduler();\r
1082 }\r
1083 /*----------------------------------------------------------*/\r
1084 \r
1085 void vTaskSuspendAll( void )\r
1086 {\r
1087         portENTER_CRITICAL();\r
1088                 ++uxSchedulerSuspended;\r
1089         portEXIT_CRITICAL();\r
1090 }\r
1091 /*----------------------------------------------------------*/\r
1092 \r
1093 signed portBASE_TYPE xTaskResumeAll( void )\r
1094 {\r
1095 register tskTCB *pxTCB;\r
1096 signed portBASE_TYPE xAlreadyYielded = pdFALSE;\r
1097 \r
1098         /* It is possible that an ISR caused a task to be removed from an event\r
1099         list while the scheduler was suspended.  If this was the case then the\r
1100         removed task will have been added to the xPendingReadyList.  Once the\r
1101         scheduler has been resumed it is safe to move all the pending ready\r
1102         tasks from this list into their appropriate ready list. */\r
1103         portENTER_CRITICAL();\r
1104         {\r
1105                 --uxSchedulerSuspended;\r
1106 \r
1107                 if( uxSchedulerSuspended == ( unsigned portBASE_TYPE ) pdFALSE )\r
1108                 {                       \r
1109                         if( uxCurrentNumberOfTasks > ( unsigned portBASE_TYPE ) 0 )\r
1110                         {\r
1111                                 portBASE_TYPE xYieldRequired = pdFALSE;\r
1112                                 \r
1113                                 /* Move any readied tasks from the pending list into the\r
1114                                 appropriate ready list. */\r
1115                                 while( ( pxTCB = ( tskTCB * ) listGET_OWNER_OF_HEAD_ENTRY(  ( ( xList * ) &xPendingReadyList ) ) ) != NULL )\r
1116                                 {\r
1117                                         vListRemove( &( pxTCB->xEventListItem ) );\r
1118                                         vListRemove( &( pxTCB->xGenericListItem ) );\r
1119                                         prvAddTaskToReadyQueue( pxTCB );\r
1120                                         \r
1121                                         /* If we have moved a task that has a priority higher than\r
1122                                         the current task then we should yield. */\r
1123                                         if( pxTCB->uxPriority >= pxCurrentTCB->uxPriority )\r
1124                                         {\r
1125                                                 xYieldRequired = pdTRUE;\r
1126                                         }\r
1127                                 }\r
1128 \r
1129                                 /* If any ticks occurred while the scheduler was suspended then\r
1130                                 they should be processed now.  This ensures the tick count does not\r
1131                                 slip, and that any delayed tasks are resumed at the correct time. */\r
1132                                 if( uxMissedTicks > ( unsigned portBASE_TYPE ) 0 )\r
1133                                 {\r
1134                                         while( uxMissedTicks > ( unsigned portBASE_TYPE ) 0 )\r
1135                                         {\r
1136                                                 vTaskIncrementTick();\r
1137                                                 --uxMissedTicks;\r
1138                                         }\r
1139 \r
1140                                         /* As we have processed some ticks it is appropriate to yield\r
1141                                         to ensure the highest priority task that is ready to run is\r
1142                                         the task actually running. */\r
1143                                         #if configUSE_PREEMPTION == 1\r
1144                                         {\r
1145                                                 xYieldRequired = pdTRUE;\r
1146                                         }\r
1147                                         #endif\r
1148                                 }\r
1149                                 \r
1150                                 if( ( xYieldRequired == pdTRUE ) || ( xMissedYield == pdTRUE ) )\r
1151                                 {\r
1152                                         xAlreadyYielded = pdTRUE;\r
1153                                         xMissedYield = pdFALSE;\r
1154                                         taskYIELD();\r
1155                                 }\r
1156                         }\r
1157                 }\r
1158         }\r
1159         portEXIT_CRITICAL();\r
1160 \r
1161         return xAlreadyYielded;\r
1162 }\r
1163 \r
1164 \r
1165 \r
1166 \r
1167 \r
1168 \r
1169 /*-----------------------------------------------------------\r
1170  * PUBLIC TASK UTILITIES documented in task.h\r
1171  *----------------------------------------------------------*/\r
1172 \r
1173 \r
1174 \r
1175 portTickType xTaskGetTickCount( void )\r
1176 {\r
1177 portTickType xTicks;\r
1178 \r
1179         /* Critical section required if running on a 16 bit processor. */\r
1180         taskENTER_CRITICAL();\r
1181         {\r
1182                 xTicks = xTickCount;\r
1183         }\r
1184         taskEXIT_CRITICAL();\r
1185 \r
1186         return xTicks;\r
1187 }\r
1188 /*-----------------------------------------------------------*/\r
1189 \r
1190 unsigned portBASE_TYPE uxTaskGetNumberOfTasks( void )\r
1191 {\r
1192 unsigned portBASE_TYPE uxNumberOfTasks;\r
1193 \r
1194         taskENTER_CRITICAL();\r
1195                 uxNumberOfTasks = uxCurrentNumberOfTasks;\r
1196         taskEXIT_CRITICAL();\r
1197 \r
1198         return uxNumberOfTasks;\r
1199 }\r
1200 /*-----------------------------------------------------------*/\r
1201 \r
1202 #if ( ( configUSE_TRACE_FACILITY == 1 ) && ( INCLUDE_vTaskDelete == 1 ) && ( INCLUDE_vTaskSuspend == 1 ) )\r
1203 \r
1204         void vTaskList( signed portCHAR *pcWriteBuffer )\r
1205         {\r
1206         unsigned portBASE_TYPE uxQueue;\r
1207 \r
1208                 /* This is a VERY costly function that should be used for debug only.\r
1209                 It leaves interrupts disabled for a LONG time. */\r
1210 \r
1211         vTaskSuspendAll();\r
1212                 {\r
1213                         /* Run through all the lists that could potentially contain a TCB and\r
1214                         report the task name, state and stack high water mark. */\r
1215 \r
1216                         pcWriteBuffer[ 0 ] = ( signed portCHAR ) 0x00;\r
1217                         strcat( ( portCHAR * ) pcWriteBuffer, ( const portCHAR * ) "\r\n" );\r
1218 \r
1219                         uxQueue = uxTopUsedPriority + 1;\r
1220 \r
1221                         do\r
1222                         {\r
1223                                 uxQueue--;\r
1224 \r
1225                                 if( !listLIST_IS_EMPTY( &( pxReadyTasksLists[ uxQueue ] ) ) )\r
1226                                 {\r
1227                                         prvListTaskWithinSingleList( pcWriteBuffer, ( xList * ) &( pxReadyTasksLists[ uxQueue ] ), tskREADY_CHAR );                     \r
1228                                 }\r
1229                         }while( uxQueue > ( unsigned portSHORT ) tskIDLE_PRIORITY );\r
1230 \r
1231                         if( !listLIST_IS_EMPTY( pxDelayedTaskList ) )\r
1232                         {\r
1233                                 prvListTaskWithinSingleList( pcWriteBuffer, ( xList * ) pxDelayedTaskList, tskBLOCKED_CHAR );\r
1234                         }\r
1235 \r
1236                         if( !listLIST_IS_EMPTY( pxOverflowDelayedTaskList ) )\r
1237                         {\r
1238                                 prvListTaskWithinSingleList( pcWriteBuffer, ( xList * ) pxOverflowDelayedTaskList, tskBLOCKED_CHAR );\r
1239                         }\r
1240 \r
1241                         if( !listLIST_IS_EMPTY( &xTasksWaitingTermination ) )\r
1242                         {\r
1243                                 prvListTaskWithinSingleList( pcWriteBuffer, ( xList * ) &xTasksWaitingTermination, tskDELETED_CHAR );\r
1244                         }\r
1245 \r
1246                         if( !listLIST_IS_EMPTY( &xSuspendedTaskList ) )\r
1247                         {\r
1248                                 prvListTaskWithinSingleList( pcWriteBuffer, ( xList * ) &xSuspendedTaskList, tskSUSPENDED_CHAR );\r
1249                         }\r
1250                 }\r
1251         xTaskResumeAll();\r
1252         }\r
1253 \r
1254 #endif\r
1255 /*----------------------------------------------------------*/\r
1256 \r
1257 #if ( configUSE_TRACE_FACILITY == 1 )\r
1258 \r
1259         void vTaskStartTrace( signed portCHAR * pcBuffer, unsigned portLONG ulBufferSize )\r
1260         {\r
1261                 portENTER_CRITICAL();\r
1262                 {\r
1263                         pcTraceBuffer = ( signed portCHAR * )pcBuffer;\r
1264                         pcTraceBufferStart = pcBuffer;\r
1265                         pcTraceBufferEnd = pcBuffer + ( ulBufferSize - tskSIZE_OF_EACH_TRACE_LINE );\r
1266                         xTracing = pdTRUE;\r
1267                 }\r
1268                 portEXIT_CRITICAL();\r
1269         }\r
1270 \r
1271 #endif\r
1272 /*----------------------------------------------------------*/\r
1273 \r
1274 #if ( configUSE_TRACE_FACILITY == 1 )\r
1275 \r
1276         unsigned portLONG ulTaskEndTrace( void )\r
1277         {\r
1278         unsigned portLONG ulBufferLength;\r
1279 \r
1280                 portENTER_CRITICAL();\r
1281                         xTracing = pdFALSE;\r
1282                 portEXIT_CRITICAL();\r
1283 \r
1284                 ulBufferLength = ( unsigned portLONG ) ( pcTraceBuffer - pcTraceBufferStart );\r
1285 \r
1286                 return ulBufferLength;\r
1287         }\r
1288 \r
1289 #endif\r
1290 \r
1291 \r
1292 \r
1293 /*-----------------------------------------------------------\r
1294  * SCHEDULER INTERNALS AVAILABLE FOR PORTING PURPOSES\r
1295  * documented in task.h\r
1296  *----------------------------------------------------------*/\r
1297 \r
1298 \r
1299 inline void vTaskIncrementTick( void )\r
1300 {\r
1301         /* Called by the portable layer each time a tick interrupt occurs.\r
1302         Increments the tick then checks to see if the new tick value will cause any\r
1303         tasks to be unblocked. */\r
1304         if( uxSchedulerSuspended == ( unsigned portBASE_TYPE ) pdFALSE )\r
1305         {\r
1306                 ++xTickCount;\r
1307                 if( xTickCount == ( portTickType ) 0 )\r
1308                 {\r
1309                         xList *pxTemp;\r
1310 \r
1311                         /* Tick count has overflowed so we need to swap the delay lists.\r
1312                         If there are any items in pxDelayedTaskList here then there is\r
1313                         an error! */\r
1314                         pxTemp = pxDelayedTaskList;\r
1315                         pxDelayedTaskList = pxOverflowDelayedTaskList;\r
1316                         pxOverflowDelayedTaskList = pxTemp;\r
1317             xNumOfOverflows++;\r
1318                 }\r
1319 \r
1320                 /* See if this tick has made a timeout expire. */\r
1321                 prvCheckDelayedTasks();\r
1322         }\r
1323         else\r
1324         {\r
1325                 ++uxMissedTicks;\r
1326 \r
1327                 /* The tick hook gets called at regular intervals, even if the\r
1328                 scheduler is locked. */\r
1329                 #if ( configUSE_TICK_HOOK == 1 )\r
1330                 {\r
1331                         extern void vApplicationTickHook( void );\r
1332 \r
1333                         vApplicationTickHook();\r
1334                 }\r
1335                 #endif\r
1336         }\r
1337 \r
1338         #if ( configUSE_TICK_HOOK == 1 )\r
1339         {\r
1340                 extern void vApplicationTickHook( void );\r
1341 \r
1342                 /* Guard against the tick hook being called when the missed tick\r
1343                 count is being unwound (when the scheduler is being unlocked. */\r
1344                 if( uxMissedTicks == 0 )\r
1345                 {\r
1346                         vApplicationTickHook();\r
1347                 }\r
1348         }\r
1349         #endif\r
1350 \r
1351         traceTASK_INCREMENT_TICK( xTickCount );\r
1352 }\r
1353 /*-----------------------------------------------------------*/\r
1354 \r
1355 #if ( ( INCLUDE_vTaskCleanUpResources == 1 ) && ( INCLUDE_vTaskSuspend == 1 ) )\r
1356 \r
1357         void vTaskCleanUpResources( void )\r
1358         {\r
1359         unsigned portSHORT usQueue;\r
1360         volatile tskTCB *pxTCB;\r
1361 \r
1362                 usQueue = ( unsigned portSHORT ) uxTopUsedPriority + ( unsigned portSHORT ) 1;\r
1363 \r
1364                 /* Remove any TCB's from the ready queues. */\r
1365                 do\r
1366                 {\r
1367                         usQueue--;\r
1368 \r
1369                         while( !listLIST_IS_EMPTY( &( pxReadyTasksLists[ usQueue ] ) ) )\r
1370                         {\r
1371                                 listGET_OWNER_OF_NEXT_ENTRY( pxTCB, &( pxReadyTasksLists[ usQueue ] ) );\r
1372                                 vListRemove( ( xListItem * ) &( pxTCB->xGenericListItem ) );\r
1373 \r
1374                                 prvDeleteTCB( ( tskTCB * ) pxTCB );\r
1375                         }\r
1376                 }while( usQueue > ( unsigned portSHORT ) tskIDLE_PRIORITY );\r
1377 \r
1378                 /* Remove any TCB's from the delayed queue. */\r
1379                 while( !listLIST_IS_EMPTY( &xDelayedTaskList1 ) )\r
1380                 {\r
1381                         listGET_OWNER_OF_NEXT_ENTRY( pxTCB, &xDelayedTaskList1 );\r
1382                         vListRemove( ( xListItem * ) &( pxTCB->xGenericListItem ) );\r
1383 \r
1384                         prvDeleteTCB( ( tskTCB * ) pxTCB );\r
1385                 }\r
1386 \r
1387                 /* Remove any TCB's from the overflow delayed queue. */\r
1388                 while( !listLIST_IS_EMPTY( &xDelayedTaskList2 ) )\r
1389                 {\r
1390                         listGET_OWNER_OF_NEXT_ENTRY( pxTCB, &xDelayedTaskList2 );\r
1391                         vListRemove( ( xListItem * ) &( pxTCB->xGenericListItem ) );\r
1392 \r
1393                         prvDeleteTCB( ( tskTCB * ) pxTCB );\r
1394                 }\r
1395 \r
1396                 while( !listLIST_IS_EMPTY( &xSuspendedTaskList ) )\r
1397                 {\r
1398                         listGET_OWNER_OF_NEXT_ENTRY( pxTCB, &xSuspendedTaskList );\r
1399                         vListRemove( ( xListItem * ) &( pxTCB->xGenericListItem ) );\r
1400 \r
1401                         prvDeleteTCB( ( tskTCB * ) pxTCB );\r
1402                 }               \r
1403         }\r
1404 \r
1405 #endif\r
1406 /*-----------------------------------------------------------*/\r
1407 \r
1408 void vTaskSwitchContext( void )\r
1409 {\r
1410         if( uxSchedulerSuspended != ( unsigned portBASE_TYPE ) pdFALSE )\r
1411         {\r
1412                 /* The scheduler is currently suspended - do not allow a context\r
1413                 switch. */\r
1414                 xMissedYield = pdTRUE;\r
1415                 return;\r
1416         }\r
1417 \r
1418         taskCHECK_FOR_STACK_OVERFLOW();\r
1419 \r
1420         /* Find the highest priority queue that contains ready tasks. */\r
1421         while( listLIST_IS_EMPTY( &( pxReadyTasksLists[ uxTopReadyPriority ] ) ) )\r
1422         {\r
1423                 --uxTopReadyPriority;\r
1424         }\r
1425 \r
1426         /* listGET_OWNER_OF_NEXT_ENTRY walks through the list, so the tasks of the\r
1427         same priority get an equal share of the processor time. */\r
1428         listGET_OWNER_OF_NEXT_ENTRY( pxCurrentTCB, &( pxReadyTasksLists[ uxTopReadyPriority ] ) );\r
1429 \r
1430         traceTASK_SWITCHED_IN();\r
1431         vWriteTraceToBuffer();\r
1432 }\r
1433 /*-----------------------------------------------------------*/\r
1434 \r
1435 void vTaskPlaceOnEventList( const xList * const pxEventList, portTickType xTicksToWait )\r
1436 {\r
1437 portTickType xTimeToWake;\r
1438 \r
1439         /* THIS FUNCTION MUST BE CALLED WITH INTERRUPTS DISABLED OR THE\r
1440         SCHEDULER SUSPENDED. */\r
1441 \r
1442         /* Place the event list item of the TCB in the appropriate event list.\r
1443         This is placed in the list in priority order so the highest priority task\r
1444         is the first to be woken by the event. */\r
1445         vListInsert( ( xList * ) pxEventList, ( xListItem * ) &( pxCurrentTCB->xEventListItem ) );\r
1446 \r
1447         /* We must remove ourselves from the ready list before adding ourselves\r
1448         to the blocked list as the same list item is used for both lists.  We have\r
1449         exclusive access to the ready lists as the scheduler is locked. */\r
1450         vListRemove( ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );\r
1451 \r
1452 \r
1453         #if ( INCLUDE_vTaskSuspend == 1 )\r
1454         {                       \r
1455                 if( xTicksToWait == portMAX_DELAY )\r
1456                 {\r
1457                         /* Add ourselves to the suspended task list instead of a delayed task\r
1458                         list to ensure we are not woken by a timing event.  We will block\r
1459                         indefinitely. */\r
1460                         vListInsertEnd( ( xList * ) &xSuspendedTaskList, ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );\r
1461                 }\r
1462                 else\r
1463                 {\r
1464                         /* Calculate the time at which the task should be woken if the event does\r
1465                         not occur.  This may overflow but this doesn't matter. */\r
1466                         xTimeToWake = xTickCount + xTicksToWait;\r
1467                 \r
1468                         listSET_LIST_ITEM_VALUE( &( pxCurrentTCB->xGenericListItem ), xTimeToWake );\r
1469                 \r
1470                         if( xTimeToWake < xTickCount )\r
1471                         {\r
1472                                 /* Wake time has overflowed.  Place this item in the overflow list. */\r
1473                                 vListInsert( ( xList * ) pxOverflowDelayedTaskList, ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );\r
1474                         }\r
1475                         else\r
1476                         {\r
1477                                 /* The wake time has not overflowed, so we can use the current block list. */\r
1478                                 vListInsert( ( xList * ) pxDelayedTaskList, ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );\r
1479                         }\r
1480                 }\r
1481         }\r
1482         #else\r
1483         {\r
1484                         /* Calculate the time at which the task should be woken if the event does\r
1485                         not occur.  This may overflow but this doesn't matter. */\r
1486                         xTimeToWake = xTickCount + xTicksToWait;\r
1487                 \r
1488                         listSET_LIST_ITEM_VALUE( &( pxCurrentTCB->xGenericListItem ), xTimeToWake );\r
1489                 \r
1490                         if( xTimeToWake < xTickCount )\r
1491                         {\r
1492                                 /* Wake time has overflowed.  Place this item in the overflow list. */\r
1493                                 vListInsert( ( xList * ) pxOverflowDelayedTaskList, ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );\r
1494                         }\r
1495                         else\r
1496                         {\r
1497                                 /* The wake time has not overflowed, so we can use the current block list. */\r
1498                                 vListInsert( ( xList * ) pxDelayedTaskList, ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );\r
1499                         }\r
1500         }\r
1501         #endif\r
1502 }\r
1503 /*-----------------------------------------------------------*/\r
1504 \r
1505 signed portBASE_TYPE xTaskRemoveFromEventList( const xList * const pxEventList )\r
1506 {\r
1507 tskTCB *pxUnblockedTCB;\r
1508 portBASE_TYPE xReturn;\r
1509 \r
1510         /* THIS FUNCTION MUST BE CALLED WITH INTERRUPTS DISABLED OR THE\r
1511         SCHEDULER SUSPENDED.  It can also be called from within an ISR. */\r
1512 \r
1513         /* The event list is sorted in priority order, so we can remove the\r
1514         first in the list, remove the TCB from the delayed list, and add\r
1515         it to the ready list.\r
1516         \r
1517         If an event is for a queue that is locked then this function will never\r
1518         get called - the lock count on the queue will get modified instead.  This\r
1519         means we can always expect exclusive access to the event list here. */\r
1520         pxUnblockedTCB = ( tskTCB * ) listGET_OWNER_OF_HEAD_ENTRY( pxEventList );\r
1521         vListRemove( &( pxUnblockedTCB->xEventListItem ) );\r
1522 \r
1523         if( uxSchedulerSuspended == ( unsigned portBASE_TYPE ) pdFALSE )\r
1524         {\r
1525                 vListRemove( &( pxUnblockedTCB->xGenericListItem ) );\r
1526                 prvAddTaskToReadyQueue( pxUnblockedTCB );\r
1527         }\r
1528         else\r
1529         {\r
1530                 /* We cannot access the delayed or ready lists, so will hold this\r
1531                 task pending until the scheduler is resumed. */\r
1532                 vListInsertEnd( ( xList * ) &( xPendingReadyList ), &( pxUnblockedTCB->xEventListItem ) );\r
1533         }\r
1534 \r
1535         if( pxUnblockedTCB->uxPriority >= pxCurrentTCB->uxPriority )\r
1536         {\r
1537                 /* Return true if the task removed from the event list has\r
1538                 a higher priority than the calling task.  This allows\r
1539                 the calling task to know if it should force a context\r
1540                 switch now. */\r
1541                 xReturn = pdTRUE;\r
1542         }\r
1543         else\r
1544         {\r
1545                 xReturn = pdFALSE;\r
1546         }\r
1547 \r
1548         return xReturn;\r
1549 }\r
1550 /*-----------------------------------------------------------*/\r
1551 \r
1552 void vTaskSetTimeOutState( xTimeOutType * const pxTimeOut )\r
1553 {\r
1554     pxTimeOut->xOverflowCount = xNumOfOverflows;\r
1555     pxTimeOut->xTimeOnEntering = xTickCount;\r
1556 }\r
1557 /*-----------------------------------------------------------*/\r
1558 \r
1559 portBASE_TYPE xTaskCheckForTimeOut( xTimeOutType * const pxTimeOut, portTickType * const pxTicksToWait )\r
1560 {\r
1561 portBASE_TYPE xReturn;\r
1562 \r
1563         #if ( INCLUDE_vTaskSuspend == 1 )\r
1564                 /* If INCLUDE_vTaskSuspend is set to 1 and the block time specified is\r
1565                 the maximum block time then the task should block indefinitely, and\r
1566                 therefore never time out. */\r
1567                 if( *pxTicksToWait == portMAX_DELAY )\r
1568                 {\r
1569                         xReturn = pdFALSE;\r
1570                 }\r
1571                 else /* We are not blocking indefinitely, perform the checks below. */\r
1572         #endif\r
1573 \r
1574     if( ( xNumOfOverflows != pxTimeOut->xOverflowCount ) && ( xTickCount >= pxTimeOut->xTimeOnEntering ) )\r
1575     {\r
1576         /* The tick count is greater than the time at which vTaskSetTimeout()\r
1577                 was called, but has also overflowed since vTaskSetTimeOut() was called.\r
1578         It must have wrapped all the way around and gone past us again. This\r
1579         passed since vTaskSetTimeout() was called. */\r
1580         xReturn = pdTRUE;\r
1581     }\r
1582     else if( ( xTickCount - pxTimeOut->xTimeOnEntering ) < *pxTicksToWait )\r
1583     {\r
1584         /* Not a genuine timeout. Adjust parameters for time remaining. */\r
1585         *pxTicksToWait -= ( xTickCount - pxTimeOut->xTimeOnEntering );\r
1586         vTaskSetTimeOutState( pxTimeOut );\r
1587         xReturn = pdFALSE;\r
1588     }\r
1589     else\r
1590     {\r
1591         xReturn = pdTRUE;\r
1592     }\r
1593 \r
1594     return xReturn;\r
1595 }\r
1596 /*-----------------------------------------------------------*/\r
1597 \r
1598 void vTaskMissedYield( void )\r
1599 {\r
1600         xMissedYield = pdTRUE;\r
1601 }\r
1602 \r
1603 /*\r
1604  * -----------------------------------------------------------\r
1605  * The Idle task.\r
1606  * ----------------------------------------------------------\r
1607  *\r
1608  * The portTASK_FUNCTION() macro is used to allow port/compiler specific\r
1609  * language extensions.  The equivalent prototype for this function is:\r
1610  *\r
1611  * void prvIdleTask( void *pvParameters );\r
1612  *\r
1613  */\r
1614 static portTASK_FUNCTION( prvIdleTask, pvParameters )\r
1615 {\r
1616         /* Stop warnings. */\r
1617         ( void ) pvParameters;\r
1618 \r
1619         for( ;; )\r
1620         {\r
1621                 /* See if any tasks have been deleted. */\r
1622                 prvCheckTasksWaitingTermination();\r
1623 \r
1624                 #if ( configUSE_PREEMPTION == 0 )\r
1625                 {\r
1626                         /* If we are not using preemption we keep forcing a task switch to\r
1627                         see if any other task has become available.  If we are using\r
1628                         preemption we don't need to do this as any task becoming available\r
1629                         will automatically get the processor anyway. */\r
1630                         taskYIELD();    \r
1631                 }\r
1632                 #endif\r
1633 \r
1634                 #if ( ( configUSE_PREEMPTION == 1 ) && ( configIDLE_SHOULD_YIELD == 1 ) )\r
1635                 {\r
1636                         /* When using preemption tasks of equal priority will be\r
1637                         timesliced.  If a task that is sharing the idle priority is ready\r
1638                         to run then the idle task should yield before the end of the\r
1639                         timeslice.\r
1640                         \r
1641                         A critical region is not required here as we are just reading from\r
1642                         the list, and an occasional incorrect value will not matter.  If\r
1643                         the ready list at the idle priority contains more than one task\r
1644                         then a task other than the idle task is ready to execute. */\r
1645                         if( listCURRENT_LIST_LENGTH( &( pxReadyTasksLists[ tskIDLE_PRIORITY ] ) ) > ( unsigned portBASE_TYPE ) 1 )\r
1646                         {\r
1647                                 taskYIELD();\r
1648                         }\r
1649                 }\r
1650                 #endif\r
1651 \r
1652                 #if ( configUSE_IDLE_HOOK == 1 )\r
1653                 {\r
1654                         extern void vApplicationIdleHook( void );\r
1655 \r
1656                         /* Call the user defined function from within the idle task.  This\r
1657                         allows the application designer to add background functionality\r
1658                         without the overhead of a separate task.\r
1659                         NOTE: vApplicationIdleHook() MUST NOT, UNDER ANY CIRCUMSTANCES,\r
1660                         CALL A FUNCTION THAT MIGHT BLOCK. */\r
1661                         vApplicationIdleHook();\r
1662                 }\r
1663                 #endif\r
1664         }\r
1665 } /*lint !e715 pvParameters is not accessed but all task functions require the same prototype. */\r
1666 \r
1667 \r
1668 \r
1669 \r
1670 \r
1671 \r
1672 \r
1673 /*-----------------------------------------------------------\r
1674  * File private functions documented at the top of the file.\r
1675  *----------------------------------------------------------*/\r
1676 \r
1677 \r
1678 \r
1679 static void prvInitialiseTCBVariables( tskTCB *pxTCB, const signed portCHAR * const pcName, unsigned portBASE_TYPE uxPriority )\r
1680 {\r
1681         /* Store the function name in the TCB. */\r
1682         strncpy( ( char * ) pxTCB->pcTaskName, ( const char * ) pcName, ( unsigned portSHORT ) configMAX_TASK_NAME_LEN );\r
1683         pxTCB->pcTaskName[ ( unsigned portSHORT ) configMAX_TASK_NAME_LEN - ( unsigned portSHORT ) 1 ] = '\0';\r
1684 \r
1685         #if ( portCRITICAL_NESTING_IN_TCB == 1 )\r
1686         {\r
1687                 pxTCB->uxCriticalNesting = ( unsigned portBASE_TYPE ) 0;\r
1688         }\r
1689         #endif\r
1690 \r
1691         /* This is used as an array index so must ensure it's not too large. */\r
1692         if( uxPriority >= configMAX_PRIORITIES )\r
1693         {\r
1694                 uxPriority = configMAX_PRIORITIES - 1;\r
1695         }\r
1696 \r
1697         pxTCB->uxPriority = uxPriority;\r
1698         #if ( configUSE_MUTEXES == 1 )\r
1699         {\r
1700                 pxTCB->uxBasePriority = uxPriority;\r
1701         }\r
1702         #endif\r
1703 \r
1704         vListInitialiseItem( &( pxTCB->xGenericListItem ) );\r
1705         vListInitialiseItem( &( pxTCB->xEventListItem ) );\r
1706 \r
1707         /* Set the pxTCB as a link back from the xListItem.  This is so we can get\r
1708         back to the containing TCB from a generic item in a list. */\r
1709         listSET_LIST_ITEM_OWNER( &( pxTCB->xGenericListItem ), pxTCB );\r
1710 \r
1711         /* Event lists are always in priority order. */\r
1712         listSET_LIST_ITEM_VALUE( &( pxTCB->xEventListItem ), configMAX_PRIORITIES - ( portTickType ) uxPriority );\r
1713         listSET_LIST_ITEM_OWNER( &( pxTCB->xEventListItem ), pxTCB );\r
1714 }\r
1715 /*-----------------------------------------------------------*/\r
1716 \r
1717 static void prvInitialiseTaskLists( void )\r
1718 {\r
1719 unsigned portBASE_TYPE uxPriority;\r
1720 \r
1721         for( uxPriority = 0; uxPriority < configMAX_PRIORITIES; uxPriority++ )\r
1722         {\r
1723                 vListInitialise( ( xList * ) &( pxReadyTasksLists[ uxPriority ] ) );\r
1724         }\r
1725 \r
1726         vListInitialise( ( xList * ) &xDelayedTaskList1 );\r
1727         vListInitialise( ( xList * ) &xDelayedTaskList2 );\r
1728         vListInitialise( ( xList * ) &xPendingReadyList );\r
1729 \r
1730         #if ( INCLUDE_vTaskDelete == 1 )\r
1731         {\r
1732                 vListInitialise( ( xList * ) &xTasksWaitingTermination );\r
1733         }\r
1734         #endif\r
1735 \r
1736         #if ( INCLUDE_vTaskSuspend == 1 )\r
1737         {\r
1738                 vListInitialise( ( xList * ) &xSuspendedTaskList );\r
1739         }\r
1740         #endif\r
1741 \r
1742         /* Start with pxDelayedTaskList using list1 and the pxOverflowDelayedTaskList\r
1743         using list2. */\r
1744         pxDelayedTaskList = &xDelayedTaskList1;\r
1745         pxOverflowDelayedTaskList = &xDelayedTaskList2;\r
1746 }\r
1747 /*-----------------------------------------------------------*/\r
1748 \r
1749 static void prvCheckTasksWaitingTermination( void )\r
1750 {                                                       \r
1751         #if ( INCLUDE_vTaskDelete == 1 )\r
1752         {                               \r
1753                 portBASE_TYPE xListIsEmpty;\r
1754 \r
1755                 /* ucTasksDeleted is used to prevent vTaskSuspendAll() being called\r
1756                 too often in the idle task. */\r
1757                 if( uxTasksDeleted > ( unsigned portBASE_TYPE ) 0 )\r
1758                 {\r
1759                         vTaskSuspendAll();\r
1760                                 xListIsEmpty = listLIST_IS_EMPTY( &xTasksWaitingTermination );                          \r
1761                         xTaskResumeAll();\r
1762 \r
1763                         if( !xListIsEmpty )\r
1764                         {\r
1765                                 tskTCB *pxTCB;\r
1766 \r
1767                                 portENTER_CRITICAL();\r
1768                                 {                       \r
1769                                         pxTCB = ( tskTCB * ) listGET_OWNER_OF_HEAD_ENTRY( ( ( xList * ) &xTasksWaitingTermination ) );\r
1770                                         vListRemove( &( pxTCB->xGenericListItem ) );\r
1771                                         --uxCurrentNumberOfTasks;\r
1772                                         --uxTasksDeleted;\r
1773                                 }\r
1774                                 portEXIT_CRITICAL();\r
1775 \r
1776                                 prvDeleteTCB( pxTCB );\r
1777                         }\r
1778                 }\r
1779         }\r
1780         #endif\r
1781 }\r
1782 /*-----------------------------------------------------------*/\r
1783 \r
1784 static tskTCB *prvAllocateTCBAndStack( unsigned portSHORT usStackDepth )\r
1785 {\r
1786 tskTCB *pxNewTCB;\r
1787 \r
1788         /* Allocate space for the TCB.  Where the memory comes from depends on\r
1789         the implementation of the port malloc function. */\r
1790         pxNewTCB = ( tskTCB * ) pvPortMalloc( sizeof( tskTCB ) );\r
1791 \r
1792         if( pxNewTCB != NULL )\r
1793         {\r
1794                 /* Allocate space for the stack used by the task being created.\r
1795                 The base of the stack memory stored in the TCB so the task can\r
1796                 be deleted later if required. */\r
1797                 pxNewTCB->pxStack = ( portSTACK_TYPE * ) pvPortMalloc( ( ( size_t )usStackDepth ) * sizeof( portSTACK_TYPE ) );\r
1798 \r
1799                 if( pxNewTCB->pxStack == NULL )\r
1800                 {\r
1801                         /* Could not allocate the stack.  Delete the allocated TCB. */\r
1802                         vPortFree( pxNewTCB );                  \r
1803                         pxNewTCB = NULL;                        \r
1804                 }               \r
1805                 else\r
1806                 {\r
1807                         /* Just to help debugging. */\r
1808                         memset( pxNewTCB->pxStack, tskSTACK_FILL_BYTE, usStackDepth * sizeof( portSTACK_TYPE ) );\r
1809                 }\r
1810         }\r
1811 \r
1812         return pxNewTCB;\r
1813 }\r
1814 /*-----------------------------------------------------------*/\r
1815 \r
1816 #if ( configUSE_TRACE_FACILITY == 1 )\r
1817 \r
1818         static void prvListTaskWithinSingleList( const signed portCHAR *pcWriteBuffer, xList *pxList, signed portCHAR cStatus )\r
1819         {\r
1820         volatile tskTCB *pxNextTCB, *pxFirstTCB;\r
1821         static portCHAR pcStatusString[ 50 ];\r
1822         unsigned portSHORT usStackRemaining;\r
1823 \r
1824                 /* Write the details of all the TCB's in pxList into the buffer. */\r
1825                 listGET_OWNER_OF_NEXT_ENTRY( pxFirstTCB, pxList );\r
1826                 do\r
1827                 {\r
1828                         listGET_OWNER_OF_NEXT_ENTRY( pxNextTCB, pxList );\r
1829                         usStackRemaining = usTaskCheckFreeStackSpace( ( unsigned portCHAR * ) pxNextTCB->pxStack );\r
1830                         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
1831                         strcat( ( portCHAR * ) pcWriteBuffer, ( portCHAR * ) pcStatusString );\r
1832 \r
1833                 } while( pxNextTCB != pxFirstTCB );\r
1834         }\r
1835 \r
1836 #endif\r
1837 /*-----------------------------------------------------------*/\r
1838 \r
1839 #if ( ( configUSE_TRACE_FACILITY == 1 ) || ( INCLUDE_uxTaskGetStackHighWaterMark == 1 ) )\r
1840 \r
1841         unsigned portSHORT usTaskCheckFreeStackSpace( const unsigned portCHAR * pucStackByte )\r
1842         {\r
1843         register unsigned portSHORT usCount = 0;\r
1844 \r
1845                 while( *pucStackByte == tskSTACK_FILL_BYTE )\r
1846                 {\r
1847                         pucStackByte -= portSTACK_GROWTH;\r
1848                         usCount++;\r
1849                 }\r
1850 \r
1851                 usCount /= sizeof( portSTACK_TYPE );\r
1852 \r
1853                 return usCount;\r
1854         }\r
1855 \r
1856 #endif\r
1857 /*-----------------------------------------------------------*/\r
1858 \r
1859 #if ( INCLUDE_uxTaskGetStackHighWaterMark == 1 )\r
1860 \r
1861         unsigned portBASE_TYPE uxTaskGetStackHighWaterMark( void )\r
1862         {\r
1863                 return usTaskCheckFreeStackSpace( ( unsigned portCHAR * ) pxCurrentTCB->pxStack );\r
1864         }\r
1865 \r
1866 #endif\r
1867 /*-----------------------------------------------------------*/\r
1868 \r
1869 #if ( ( INCLUDE_vTaskDelete == 1 ) || ( INCLUDE_vTaskCleanUpResources == 1 ) )\r
1870 \r
1871         static void prvDeleteTCB( tskTCB *pxTCB )\r
1872         {\r
1873                 /* Free up the memory allocated by the scheduler for the task.  It is up to\r
1874                 the task to free any memory allocated at the application level. */\r
1875                 vPortFree( pxTCB->pxStack );\r
1876                 vPortFree( pxTCB );\r
1877         }\r
1878 \r
1879 #endif\r
1880 \r
1881 \r
1882 /*-----------------------------------------------------------*/\r
1883 \r
1884 #if ( INCLUDE_xTaskGetCurrentTaskHandle == 1 )\r
1885 \r
1886         xTaskHandle xTaskGetCurrentTaskHandle( void )\r
1887         {\r
1888         xTaskHandle xReturn;\r
1889 \r
1890                 portENTER_CRITICAL();\r
1891                 {\r
1892                         xReturn = ( xTaskHandle ) pxCurrentTCB;\r
1893                 }\r
1894                 portEXIT_CRITICAL();\r
1895 \r
1896                 return xReturn;\r
1897         }\r
1898 \r
1899 #endif\r
1900 \r
1901 /*-----------------------------------------------------------*/\r
1902 \r
1903 #if ( INCLUDE_xTaskGetSchedulerState == 1 )\r
1904 \r
1905         portBASE_TYPE xTaskGetSchedulerState( void )\r
1906         {\r
1907         portBASE_TYPE xReturn;\r
1908         \r
1909                 if( xSchedulerRunning == pdFALSE )\r
1910                 {\r
1911                         xReturn = taskSCHEDULER_NOT_STARTED;\r
1912                 }\r
1913                 else\r
1914                 {\r
1915                         if( uxSchedulerSuspended == ( unsigned portBASE_TYPE ) pdFALSE )\r
1916                         {\r
1917                                 xReturn = taskSCHEDULER_RUNNING;\r
1918                         }\r
1919                         else\r
1920                         {\r
1921                                 xReturn = taskSCHEDULER_SUSPENDED;\r
1922                         }\r
1923                 }\r
1924                 \r
1925                 return xReturn;\r
1926         }\r
1927 \r
1928 #endif\r
1929 /*-----------------------------------------------------------*/\r
1930 \r
1931 #if ( configUSE_MUTEXES == 1 )\r
1932         \r
1933         void vTaskPriorityInherit( xTaskHandle * const pxMutexHolder )\r
1934         {\r
1935         tskTCB * const pxTCB = ( tskTCB * ) pxMutexHolder;\r
1936 \r
1937                 if( pxTCB->uxPriority < pxCurrentTCB->uxPriority )\r
1938                 {\r
1939                         /* Adjust the mutex holder state to account for its new priority. */\r
1940                         listSET_LIST_ITEM_VALUE( &( pxTCB->xEventListItem ), configMAX_PRIORITIES - ( portTickType ) pxCurrentTCB->uxPriority );\r
1941 \r
1942                         /* If the task being modified is in the ready state it will need to\r
1943                         be moved in to a new list. */\r
1944                         if( listIS_CONTAINED_WITHIN( &( pxReadyTasksLists[ pxTCB->uxPriority ] ), &( pxTCB->xGenericListItem ) ) )\r
1945                         {\r
1946                                 vListRemove( &( pxTCB->xGenericListItem ) );\r
1947 \r
1948                                 /* Inherit the priority before being moved into the new list. */\r
1949                                 pxTCB->uxPriority = pxCurrentTCB->uxPriority;\r
1950                                 prvAddTaskToReadyQueue( pxTCB );\r
1951                         }\r
1952                         else\r
1953                         {\r
1954                                 /* Just inherit the priority. */\r
1955                                 pxTCB->uxPriority = pxCurrentTCB->uxPriority;\r
1956                         }\r
1957                 }\r
1958         }\r
1959 \r
1960 #endif\r
1961 /*-----------------------------------------------------------*/\r
1962 \r
1963 #if ( configUSE_MUTEXES == 1 )  \r
1964 \r
1965         void vTaskPriorityDisinherit( xTaskHandle * const pxMutexHolder )\r
1966         {\r
1967         tskTCB * const pxTCB = ( tskTCB * ) pxMutexHolder;\r
1968 \r
1969                 if( pxMutexHolder != NULL )\r
1970                 {\r
1971                         if( pxTCB->uxPriority != pxTCB->uxBasePriority )\r
1972                         {\r
1973                                 /* We must be the running task to be able to give the mutex back.\r
1974                                 Remove ourselves from the ready list we currently appear in. */\r
1975                                 vListRemove( &( pxTCB->xGenericListItem ) );\r
1976 \r
1977                                 /* Disinherit the priority before adding ourselves into the new\r
1978                                 ready list. */\r
1979                                 pxTCB->uxPriority = pxTCB->uxBasePriority;\r
1980                                 listSET_LIST_ITEM_VALUE( &( pxTCB->xEventListItem ), configMAX_PRIORITIES - ( portTickType ) pxTCB->uxPriority );\r
1981                                 prvAddTaskToReadyQueue( pxTCB );\r
1982                         }\r
1983                 }\r
1984         }\r
1985 \r
1986 #endif\r
1987 /*-----------------------------------------------------------*/\r
1988 \r
1989 #if ( portCRITICAL_NESTING_IN_TCB == 1 )\r
1990 \r
1991         void vTaskEnterCritical( void )\r
1992         {\r
1993                 portDISABLE_INTERRUPTS();\r
1994 \r
1995                 if( xSchedulerRunning != pdFALSE )\r
1996                 {\r
1997                         pxCurrentTCB->uxCriticalNesting++;\r
1998                 }\r
1999         }\r
2000 \r
2001 #endif\r
2002 /*-----------------------------------------------------------*/\r
2003 \r
2004 #if ( portCRITICAL_NESTING_IN_TCB == 1 )\r
2005 \r
2006 void vTaskExitCritical( void )\r
2007 {\r
2008         if( xSchedulerRunning != pdFALSE )\r
2009         {\r
2010                 if( pxCurrentTCB->uxCriticalNesting > 0 )\r
2011                 {\r
2012                         pxCurrentTCB->uxCriticalNesting--;\r
2013 \r
2014                         if( pxCurrentTCB->uxCriticalNesting == 0 )\r
2015                         {\r
2016                                 portENABLE_INTERRUPTS();\r
2017                         }\r
2018                 }\r
2019         }\r
2020 }\r
2021 \r
2022 #endif\r
2023 /*-----------------------------------------------------------*/\r
2024 \r
2025 \r
2026         \r
2027 \r