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   1 /*\r
   2         FreeRTOS.org V4.8.0 - 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     *                                                                         *\r
  29     * SAVE TIME AND MONEY!  We can port FreeRTOS.org to your own hardware,    *\r
  30     * and even write all or part of your application on your behalf.          *\r
  31     * See http://www.OpenRTOS.com for details of the services we provide to   *\r
  32     * expedite your project.                                                  *\r
  33     *                                                                         *\r
  34     ***************************************************************************\r
  35     ***************************************************************************\r
  36 \r
  37         Please ensure to read the configuration and relevant port sections of the\r
  38         online documentation.\r
  39 \r
  40         http://www.FreeRTOS.org - Documentation, latest information, license and \r
  41         contact details.\r
  42 \r
  43         http://www.SafeRTOS.com - A version that is certified for use in safety \r
  44         critical systems.\r
  45 \r
  46         http://www.OpenRTOS.com - Commercial support, development, porting, \r
  47         licensing and training services.\r
  48 */\r
  49 \r
  50 \r
  51 #include <stdio.h>\r
  52 #include <stdlib.h>\r
  53 #include <string.h>\r
  54 \r
  55 #include "FreeRTOS.h"\r
  56 #include "task.h"\r
  57 \r
  58 /*\r
  59  * Macro to define the amount of stack available to the idle task.\r
  60  */\r
  61 #define tskIDLE_STACK_SIZE      configMINIMAL_STACK_SIZE\r
  62 \r
  63 \r
  64 /*\r
  65  * Default a definitions for backwards compatibility with old\r
  66  * portmacro.h files.\r
  67  */\r
  68 #ifndef configMAX_TASK_NAME_LEN\r
  69         #define configMAX_TASK_NAME_LEN 16\r
  70 #endif\r
  71 \r
  72 #ifndef configIDLE_SHOULD_YIELD\r
  73         #define configIDLE_SHOULD_YIELD         1\r
  74 #endif\r
  75 \r
  76 #if configMAX_TASK_NAME_LEN < 1\r
  77         #undef configMAX_TASK_NAME_LEN\r
  78         #define configMAX_TASK_NAME_LEN 1\r
  79 #endif\r
  80 \r
  81 #ifndef INCLUDE_xTaskResumeFromISR\r
  82         #define INCLUDE_xTaskResumeFromISR 1\r
  83 #endif\r
  84 \r
  85 #ifndef INCLUDE_xTaskGetSchedulerState\r
  86         #define INCLUDE_xTaskGetSchedulerState 0\r
  87 #endif\r
  88 \r
  89 /*\r
  90  * Task control block.  A task control block (TCB) is allocated to each task,\r
  91  * and stores the context of the task.\r
  92  */\r
  93 typedef struct tskTaskControlBlock\r
  94 {\r
  95         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
  96         xListItem                               xGenericListItem;       /*< List item used to place the TCB in ready and blocked queues. */\r
  97         xListItem                               xEventListItem;         /*< List item used to place the TCB in event lists. */\r
  98         unsigned portBASE_TYPE  uxPriority;                     /*< The priority of the task where 0 is the lowest priority. */\r
  99         portSTACK_TYPE                  *pxStack;                       /*< Points to the start of the stack. */\r
 100         signed portCHAR                 pcTaskName[ configMAX_TASK_NAME_LEN ];/*< Descriptive name given to the task when created.  Facilitates debugging only. */\r
 101 \r
 102         #if ( portCRITICAL_NESTING_IN_TCB == 1 )\r
 103                 unsigned portBASE_TYPE uxCriticalNesting;\r
 104         #endif\r
 105 \r
 106         #if ( configUSE_TRACE_FACILITY == 1 )\r
 107                 unsigned portBASE_TYPE  uxTCBNumber;            /*< This is used for tracing the scheduler and making debugging easier only. */\r
 108         #endif  \r
 109                 \r
 110         #if ( configUSE_MUTEXES == 1 )\r
 111                 unsigned portBASE_TYPE uxBasePriority;\r
 112         #endif\r
 113                 \r
 114 } tskTCB;\r
 115 \r
 116 /*lint -e956 */\r
 117 \r
 118 tskTCB * volatile pxCurrentTCB = NULL;                                  \r
 119 \r
 120 /* Lists for ready and blocked tasks. --------------------*/\r
 121 \r
 122 static xList pxReadyTasksLists[ configMAX_PRIORITIES ]; /*< Prioritised ready tasks. */\r
 123 static xList xDelayedTaskList1;                                                 /*< Delayed tasks. */\r
 124 static xList xDelayedTaskList2;                                                 /*< Delayed tasks (two lists are used - one for delays that have overflowed the current tick count. */\r
 125 static xList * volatile pxDelayedTaskList;                              /*< Points to the delayed task list currently being used. */\r
 126 static xList * volatile pxOverflowDelayedTaskList;              /*< Points to the delayed task list currently being used to hold tasks that have overflowed the current tick count. */\r
 127 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
 128 \r
 129 #if ( INCLUDE_vTaskDelete == 1 )\r
 130 \r
 131         static volatile xList xTasksWaitingTermination;         /*< Tasks that have been deleted - but the their memory not yet freed. */\r
 132         static volatile unsigned portBASE_TYPE uxTasksDeleted = ( unsigned portBASE_TYPE ) 0;\r
 133 \r
 134 #endif\r
 135 \r
 136 #if ( INCLUDE_vTaskSuspend == 1 )\r
 137 \r
 138         static xList xSuspendedTaskList;                                        /*< Tasks that are currently suspended. */\r
 139 \r
 140 #endif\r
 141 \r
 142 /* File private variables. --------------------------------*/\r
 143 static volatile unsigned portBASE_TYPE uxCurrentNumberOfTasks   = ( unsigned portBASE_TYPE ) 0;\r
 144 static volatile portTickType xTickCount                                                 = ( portTickType ) 0;\r
 145 static unsigned portBASE_TYPE uxTopUsedPriority                                 = tskIDLE_PRIORITY;\r
 146 static volatile unsigned portBASE_TYPE uxTopReadyPriority               = tskIDLE_PRIORITY;\r
 147 static volatile signed portBASE_TYPE xSchedulerRunning                  = pdFALSE;\r
 148 static volatile unsigned portBASE_TYPE uxSchedulerSuspended             = ( unsigned portBASE_TYPE ) pdFALSE;\r
 149 static volatile unsigned portBASE_TYPE uxMissedTicks                    = ( unsigned portBASE_TYPE ) 0;\r
 150 static volatile portBASE_TYPE xMissedYield                                              = ( portBASE_TYPE ) pdFALSE;\r
 151 static volatile portBASE_TYPE xNumOfOverflows                                   = ( portBASE_TYPE ) 0;\r
 152 /* Debugging and trace facilities private variables and macros. ------------*/\r
 153 \r
 154 /*\r
 155  * The value used to fill the stack of a task when the task is created.  This\r
 156  * is used purely for checking the high water mark for tasks.\r
 157  */\r
 158 #define tskSTACK_FILL_BYTE      ( 0xa5 )\r
 159 \r
 160 /*\r
 161  * Macros used by vListTask to indicate which state a task is in.\r
 162  */\r
 163 #define tskBLOCKED_CHAR         ( ( signed portCHAR ) 'B' )\r
 164 #define tskREADY_CHAR           ( ( signed portCHAR ) 'R' )\r
 165 #define tskDELETED_CHAR         ( ( signed portCHAR ) 'D' )\r
 166 #define tskSUSPENDED_CHAR       ( ( signed portCHAR ) 'S' )\r
 167 \r
 168 /*\r
 169  * Macros and private variables used by the trace facility.\r
 170  */\r
 171 #if ( configUSE_TRACE_FACILITY == 1 )\r
 172 \r
 173         #define tskSIZE_OF_EACH_TRACE_LINE                      ( ( unsigned portLONG ) ( sizeof( unsigned portLONG ) + sizeof( unsigned portLONG ) ) )\r
 174         static volatile signed portCHAR * volatile pcTraceBuffer;\r
 175         static signed portCHAR *pcTraceBufferStart;\r
 176         static signed portCHAR *pcTraceBufferEnd;\r
 177         static signed portBASE_TYPE xTracing = pdFALSE;\r
 178 \r
 179 #endif\r
 180 \r
 181 /*-----------------------------------------------------------*/\r
 182 \r
 183 /*\r
 184  * Macro that writes a trace of scheduler activity to a buffer.  This trace\r
 185  * shows which task is running when and is very useful as a debugging tool.\r
 186  * As this macro is called each context switch it is a good idea to undefine\r
 187  * it if not using the facility.\r
 188  */\r
 189 #if ( configUSE_TRACE_FACILITY == 1 )\r
 190 \r
 191         #define vWriteTraceToBuffer()                                                                                                                                   \\r
 192         {                                                                                                                                                                                               \\r
 193                 if( xTracing )                                                                                                                                                          \\r
 194                 {                                                                                                                                                                                       \\r
 195                         static unsigned portBASE_TYPE uxPreviousTask = 255;                                                                             \\r
 196                                                                                                                                                                                                         \\r
 197                         if( uxPreviousTask != pxCurrentTCB->uxTCBNumber )                                                                               \\r
 198                         {                                                                                                                                                                               \\r
 199                                 if( ( pcTraceBuffer + tskSIZE_OF_EACH_TRACE_LINE ) < pcTraceBufferEnd )                         \\r
 200                                 {                                                                                                                                                                       \\r
 201                                         uxPreviousTask = pxCurrentTCB->uxTCBNumber;                                                                             \\r
 202                                         *( unsigned portLONG * ) pcTraceBuffer = ( unsigned portLONG ) xTickCount;              \\r
 203                                         pcTraceBuffer += sizeof( unsigned portLONG );                                                                   \\r
 204                                         *( unsigned portLONG * ) pcTraceBuffer = ( unsigned portLONG ) uxPreviousTask;  \\r
 205                                         pcTraceBuffer += sizeof( unsigned portLONG );                                                                   \\r
 206                                 }                                                                                                                                                                       \\r
 207                                 else                                                                                                                                                            \\r
 208                                 {                                                                                                                                                                       \\r
 209                                         xTracing = pdFALSE;                                                                                                                             \\r
 210                                 }                                                                                                                                                                       \\r
 211                         }                                                                                                                                                                               \\r
 212                 }                                                                                                                                                                                       \\r
 213         }\r
 214 \r
 215 #else\r
 216 \r
 217         #define vWriteTraceToBuffer()\r
 218 \r
 219 #endif\r
 220 /*-----------------------------------------------------------*/\r
 221 \r
 222 /*\r
 223  * Place the task represented by pxTCB into the appropriate ready queue for\r
 224  * the task.  It is inserted at the end of the list.  One quirk of this is\r
 225  * that if the task being inserted is at the same priority as the currently\r
 226  * executing task, then it will only be rescheduled after the currently\r
 227  * executing task has been rescheduled.\r
 228  */\r
 229 #define prvAddTaskToReadyQueue( pxTCB )                                                                                                                                                 \\r
 230 {                                                                                                                                                                                                                               \\r
 231         if( pxTCB->uxPriority > uxTopReadyPriority )                                                                                                                            \\r
 232         {                                                                                                                                                                                                                       \\r
 233                 uxTopReadyPriority = pxTCB->uxPriority;                                                                                                                                 \\r
 234         }                                                                                                                                                                                                                       \\r
 235         vListInsertEnd( ( xList * ) &( pxReadyTasksLists[ pxTCB->uxPriority ] ), &( pxTCB->xGenericListItem ) );        \\r
 236 }\r
 237 /*-----------------------------------------------------------*/         \r
 238 \r
 239 /*\r
 240  * Macro that looks at the list of tasks that are currently delayed to see if\r
 241  * any require waking.\r
 242  *\r
 243  * Tasks are stored in the queue in the order of their wake time - meaning\r
 244  * once one tasks has been found whose timer has not expired we need not look\r
 245  * any further down the list.\r
 246  */\r
 247 #define prvCheckDelayedTasks()                                                                                                                                                                          \\r
 248 {                                                                                                                                                                                                                                       \\r
 249 register tskTCB *pxTCB;                                                                                                                                                                                         \\r
 250                                                                                                                                                                                                                                         \\r
 251         while( ( pxTCB = ( tskTCB * ) listGET_OWNER_OF_HEAD_ENTRY( pxDelayedTaskList ) ) != NULL )                                              \\r
 252         {                                                                                                                                                                                                                               \\r
 253                 if( xTickCount < listGET_LIST_ITEM_VALUE( &( pxTCB->xGenericListItem ) ) )                                                                      \\r
 254                 {                                                                                                                                                                                                                       \\r
 255                         break;                                                                                                                                                                                                  \\r
 256                 }                                                                                                                                                                                                                       \\r
 257                 vListRemove( &( pxTCB->xGenericListItem ) );                                                                                                                            \\r
 258                 /* Is the task waiting on an event also? */                                                                                                                                     \\r
 259                 if( pxTCB->xEventListItem.pvContainer )                                                                                                                                         \\r
 260                 {                                                                                                                                                                                                                       \\r
 261                         vListRemove( &( pxTCB->xEventListItem ) );                                                                                                                              \\r
 262                 }                                                                                                                                                                                                                       \\r
 263                 prvAddTaskToReadyQueue( pxTCB );                                                                                                                                                        \\r
 264         }                                                                                                                                                                                                                               \\r
 265 }\r
 266 /*-----------------------------------------------------------*/\r
 267 \r
 268 /*\r
 269  * Call the stack overflow hook function if the stack of the task being swapped\r
 270  * out is currently overflowed, or looks like it might have overflowed in the\r
 271  * past.\r
 272  *\r
 273  * Setting configCHECK_FOR_STACK_OVERFLOW to 1 will cause the macro to check\r
 274  * the current stack state only - comparing the current top of stack value to\r
 275  * the stack limit.  Setting configCHECK_FOR_STACK_OVERFLOW to greater than 1\r
 276  * will also cause the last few stack bytes to be checked to ensure the value\r
 277  * to which the bytes were set when the task was created have not been \r
 278  * overwritten.  Note this second test does not guarantee that an overflowed\r
 279  * stack will always be recognised.\r
 280  */\r
 281 \r
 282 #if( configCHECK_FOR_STACK_OVERFLOW == 0 )\r
 283 \r
 284         /* FreeRTOSConfig.h is not set to check for stack overflows. */\r
 285         #define taskCHECK_FOR_STACK_OVERFLOW()\r
 286 \r
 287 #endif /* configCHECK_FOR_STACK_OVERFLOW == 0 */\r
 288 \r
 289 #if( ( configCHECK_FOR_STACK_OVERFLOW > 0 ) && ( portSTACK_GROWTH >= 0 ) )\r
 290 \r
 291         /* This is an invalid setting. */\r
 292         #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
 293 \r
 294 #endif /* ( configCHECK_FOR_STACK_OVERFLOW > 0 ) && ( portSTACK_GROWTH >= 0 ) */\r
 295 \r
 296 #if( configCHECK_FOR_STACK_OVERFLOW == 1 )\r
 297 \r
 298         /* Only the current stack state is to be checked. */\r
 299         #define taskCHECK_FOR_STACK_OVERFLOW()                                                                                                                          \\r
 300         {                                                                                                                                                                                                       \\r
 301         extern void vApplicationStackOverflowHook( xTaskHandle *pxTask, signed portCHAR *pcTaskName );          \\r
 302                                                                                                                                                                                                                 \\r
 303                 /* Is the currently saved stack pointer within the stack limit? */                                                              \\r
 304                 if( pxCurrentTCB->pxTopOfStack <= pxCurrentTCB->pxStack )                                                                               \\r
 305                 {                                                                                                                                                                                               \\r
 306                         vApplicationStackOverflowHook( ( xTaskHandle ) pxCurrentTCB, pxCurrentTCB->pcTaskName );        \\r
 307                 }                                                                                                                                                                                               \\r
 308         }\r
 309 \r
 310 #endif /* configCHECK_FOR_STACK_OVERFLOW == 1 */\r
 311 \r
 312 #if( configCHECK_FOR_STACK_OVERFLOW > 1 )\r
 313 \r
 314         /* Both the current statck state and the stack fill bytes are to be checked. */\r
 315         #define taskCHECK_FOR_STACK_OVERFLOW()                                                                                                                                                                                                                  \\r
 316         {                                                                                                                                                                                                                                                                                               \\r
 317         extern void vApplicationStackOverflowHook( xTaskHandle *pxTask, signed portCHAR *pcTaskName );                                                                                                  \\r
 318         static const unsigned portCHAR ucExpectedStackBytes[] = {       tskSTACK_FILL_BYTE, tskSTACK_FILL_BYTE, tskSTACK_FILL_BYTE, tskSTACK_FILL_BYTE,         \\r
 319                                                                                                                                 tskSTACK_FILL_BYTE, tskSTACK_FILL_BYTE, tskSTACK_FILL_BYTE, tskSTACK_FILL_BYTE,         \\r
 320                                                                                                                                 tskSTACK_FILL_BYTE, tskSTACK_FILL_BYTE, tskSTACK_FILL_BYTE, tskSTACK_FILL_BYTE,         \\r
 321                                                                                                                                 tskSTACK_FILL_BYTE, tskSTACK_FILL_BYTE, tskSTACK_FILL_BYTE, tskSTACK_FILL_BYTE,         \\r
 322                                                                                                                                 tskSTACK_FILL_BYTE, tskSTACK_FILL_BYTE, tskSTACK_FILL_BYTE, tskSTACK_FILL_BYTE };       \\r
 323                                                                                                                                                                                                                                                                                                         \\r
 324                 /* Is the currently saved stack pointer within the stack limit? */                                                                                                                                                      \\r
 325                 if( pxCurrentTCB->pxTopOfStack <= pxCurrentTCB->pxStack )                                                                                                                                                                       \\r
 326                 {                                                                                                                                                                                                                                                                                       \\r
 327                         vApplicationStackOverflowHook( ( xTaskHandle ) pxCurrentTCB, pxCurrentTCB->pcTaskName );                                                                                                \\r
 328                 }                                                                                                                                                                                                                                                                                       \\r
 329                                                                                                                                                                                                                                                                                                         \\r
 330                 /* Has the extremity of the task stack ever been written over? */                                                                                                                                                       \\r
 331                 if( memcmp( ( void * ) pxCurrentTCB->pxStack, ( void * ) ucExpectedStackBytes, sizeof( ucExpectedStackBytes ) ) != 0 )                                          \\r
 332                 {                                                                                                                                                                                                                                                                                       \\r
 333                         vApplicationStackOverflowHook( ( xTaskHandle ) pxCurrentTCB, pxCurrentTCB->pcTaskName );                                                                                                \\r
 334                 }                                                                                                                                                                                                                                                                                       \\r
 335         }\r
 336 \r
 337 #endif /* #if( configCHECK_FOR_STACK_OVERFLOW > 1 ) */\r
 338 \r
 339 /*-----------------------------------------------------------*/\r
 340 \r
 341 /*\r
 342  * Several functions take an xTaskHandle parameter that can optionally be NULL,\r
 343  * where NULL is used to indicate that the handle of the currently executing\r
 344  * task should be used in place of the parameter.  This macro simply checks to\r
 345  * see if the parameter is NULL and returns a pointer to the appropriate TCB.\r
 346  */\r
 347 #define prvGetTCBFromHandle( pxHandle ) ( ( pxHandle == NULL ) ? ( tskTCB * ) pxCurrentTCB : ( tskTCB * ) pxHandle )\r
 348 \r
 349 \r
 350 /* File private functions. --------------------------------*/\r
 351 \r
 352 /*\r
 353  * Utility to ready a TCB for a given task.  Mainly just copies the parameters\r
 354  * into the TCB structure.\r
 355  */\r
 356 static void prvInitialiseTCBVariables( tskTCB *pxTCB, const signed portCHAR * const pcName, unsigned portBASE_TYPE uxPriority );\r
 357 \r
 358 /*\r
 359  * Utility to ready all the lists used by the scheduler.  This is called\r
 360  * automatically upon the creation of the first task.\r
 361  */\r
 362 static void prvInitialiseTaskLists( void );\r
 363 \r
 364 /*\r
 365  * The idle task, which as all tasks is implemented as a never ending loop.\r
 366  * The idle task is automatically created and added to the ready lists upon\r
 367  * creation of the first user task.\r
 368  *\r
 369  * The portTASK_FUNCTION_PROTO() macro is used to allow port/compiler specific\r
 370  * language extensions.  The equivalent prototype for this function is:\r
 371  *\r
 372  * void prvIdleTask( void *pvParameters );\r
 373  *\r
 374  */\r
 375 static portTASK_FUNCTION_PROTO( prvIdleTask, pvParameters );\r
 376 \r
 377 /*\r
 378  * Utility to free all memory allocated by the scheduler to hold a TCB,\r
 379  * including the stack pointed to by the TCB.\r
 380  *\r
 381  * This does not free memory allocated by the task itself (i.e. memory\r
 382  * allocated by calls to pvPortMalloc from within the tasks application code).\r
 383  */\r
 384 #if ( ( INCLUDE_vTaskDelete == 1 ) || ( INCLUDE_vTaskCleanUpResources == 1 ) )\r
 385         static void prvDeleteTCB( tskTCB *pxTCB );\r
 386 #endif\r
 387 \r
 388 /*\r
 389  * Used only by the idle task.  This checks to see if anything has been placed\r
 390  * in the list of tasks waiting to be deleted.  If so the task is cleaned up\r
 391  * and its TCB deleted.\r
 392  */\r
 393 static void prvCheckTasksWaitingTermination( void );\r
 394 \r
 395 /*\r
 396  * Allocates memory from the heap for a TCB and associated stack.  Checks the\r
 397  * allocation was successful.\r
 398  */\r
 399 static tskTCB *prvAllocateTCBAndStack( unsigned portSHORT usStackDepth );\r
 400 \r
 401 /*\r
 402  * Called from vTaskList.  vListTasks details all the tasks currently under\r
 403  * control of the scheduler.  The tasks may be in one of a number of lists.\r
 404  * prvListTaskWithinSingleList accepts a list and details the tasks from\r
 405  * within just that list.\r
 406  *\r
 407  * THIS FUNCTION IS INTENDED FOR DEBUGGING ONLY, AND SHOULD NOT BE CALLED FROM\r
 408  * NORMAL APPLICATION CODE.\r
 409  */\r
 410 #if ( configUSE_TRACE_FACILITY == 1 )\r
 411 \r
 412         static void prvListTaskWithinSingleList( const signed portCHAR *pcWriteBuffer, xList *pxList, signed portCHAR cStatus );\r
 413 \r
 414 #endif\r
 415 \r
 416 /*\r
 417  * When a task is created, the stack of the task is filled with a known value.\r
 418  * This function determines the 'high water mark' of the task stack by\r
 419  * determining how much of the stack remains at the original preset value.\r
 420  */\r
 421 #if ( ( configUSE_TRACE_FACILITY == 1 ) || ( INCLUDE_uxTaskGetStackHighWaterMark == 1 ) )\r
 422 \r
 423         unsigned portSHORT usTaskCheckFreeStackSpace( const unsigned portCHAR * pucStackByte );\r
 424 \r
 425 #endif\r
 426 \r
 427 /*\r
 428  * Checks that a task being resumed (unsuspended) is actually in the Suspended\r
 429  * state.\r
 430  */\r
 431 #if ( INCLUDE_vTaskSuspend == 1 )\r
 432 \r
 433         static portBASE_TYPE prvIsTaskSuspended( const tskTCB * const pxTCB );  \r
 434 \r
 435 #endif\r
 436 \r
 437 /*lint +e956 */\r
 438 \r
 439 \r
 440 \r
 441 /*-----------------------------------------------------------\r
 442  * TASK CREATION API documented in task.h\r
 443  *----------------------------------------------------------*/\r
 444 \r
 445 signed portBASE_TYPE xTaskCreate( pdTASK_CODE pvTaskCode, const signed portCHAR * const pcName, unsigned portSHORT usStackDepth, void *pvParameters, unsigned portBASE_TYPE uxPriority, xTaskHandle *pxCreatedTask )\r
 446 {\r
 447 signed portBASE_TYPE xReturn;\r
 448 tskTCB * pxNewTCB;\r
 449 #if ( configUSE_TRACE_FACILITY == 1 )\r
 450         static unsigned portBASE_TYPE uxTaskNumber = 0; /*lint !e956 Static is deliberate - this is guarded before use. */\r
 451 #endif\r
 452 \r
 453         /* Allocate the memory required by the TCB and stack for the new task.\r
 454         checking that the allocation was successful. */\r
 455         pxNewTCB = prvAllocateTCBAndStack( usStackDepth );\r
 456 \r
 457         if( pxNewTCB != NULL )\r
 458         {               \r
 459                 portSTACK_TYPE *pxTopOfStack;\r
 460 \r
 461                 /* Setup the newly allocated TCB with the initial state of the task. */\r
 462                 prvInitialiseTCBVariables( pxNewTCB, pcName, uxPriority );\r
 463 \r
 464                 /* Calculate the top of stack address.  This depends on whether the\r
 465                 stack grows from high memory to low (as per the 80x86) or visa versa.\r
 466                 portSTACK_GROWTH is used to make the result positive or negative as\r
 467                 required by the port. */\r
 468                 #if portSTACK_GROWTH < 0\r
 469                 {\r
 470                         pxTopOfStack = pxNewTCB->pxStack + ( usStackDepth - 1 );\r
 471                 }\r
 472                 #else\r
 473                 {\r
 474                         pxTopOfStack = pxNewTCB->pxStack;       \r
 475                 }\r
 476                 #endif\r
 477 \r
 478                 /* Initialize the TCB stack to look as if the task was already running,\r
 479                 but had been interrupted by the scheduler.  The return address is set\r
 480                 to the start of the task function. Once the stack has been initialised\r
 481                 the     top of stack variable is updated. */\r
 482                 pxNewTCB->pxTopOfStack = pxPortInitialiseStack( pxTopOfStack, pvTaskCode, pvParameters );\r
 483 \r
 484                 /* We are going to manipulate the task queues to add this task to a\r
 485                 ready list, so must make sure no interrupts occur. */\r
 486                 portENTER_CRITICAL();\r
 487                 {\r
 488                         uxCurrentNumberOfTasks++;\r
 489                         if( uxCurrentNumberOfTasks == ( unsigned portBASE_TYPE ) 1 )\r
 490                         {\r
 491                                 /* As this is the first task it must also be the current task. */\r
 492                                 pxCurrentTCB =  pxNewTCB;\r
 493 \r
 494                                 /* This is the first task to be created so do the preliminary\r
 495                                 initialisation required.  We will not recover if this call\r
 496                                 fails, but we will report the failure. */\r
 497                                 prvInitialiseTaskLists();\r
 498                         }\r
 499                         else\r
 500                         {       \r
 501                                 /* If the scheduler is not already running, make this task the\r
 502                                 current task if it is the highest priority task to be created\r
 503                                 so far. */\r
 504                                 if( xSchedulerRunning == pdFALSE )\r
 505                                 {\r
 506                                         if( pxCurrentTCB->uxPriority <= uxPriority )\r
 507                                         {\r
 508                                                 pxCurrentTCB = pxNewTCB;        \r
 509                                         }\r
 510                                 }\r
 511                         }                               \r
 512 \r
 513                         /* Remember the top priority to make context switching faster.  Use\r
 514                         the priority in pxNewTCB as this has been capped to a valid value. */\r
 515                         if( pxNewTCB->uxPriority > uxTopUsedPriority )\r
 516                         {\r
 517                                 uxTopUsedPriority = pxNewTCB->uxPriority;\r
 518                         }\r
 519 \r
 520                         #if ( configUSE_TRACE_FACILITY == 1 )\r
 521                         {\r
 522                                 /* Add a counter into the TCB for tracing only. */\r
 523                                 pxNewTCB->uxTCBNumber = uxTaskNumber;\r
 524                                 uxTaskNumber++;\r
 525                         }\r
 526                         #endif\r
 527 \r
 528                         prvAddTaskToReadyQueue( pxNewTCB );\r
 529 \r
 530                         xReturn = pdPASS;\r
 531                         traceTASK_CREATE( pxNewTCB );\r
 532                 }\r
 533                 portEXIT_CRITICAL();\r
 534         }\r
 535         else\r
 536         {\r
 537                 xReturn = errCOULD_NOT_ALLOCATE_REQUIRED_MEMORY;\r
 538                 traceTASK_CREATE_FAILED( pxNewTCB );\r
 539         }\r
 540 \r
 541         if( xReturn == pdPASS )\r
 542         {\r
 543                 if( ( void * ) pxCreatedTask != NULL )\r
 544                 {\r
 545                         /* Pass the TCB out - in an anonymous way.  The calling function/\r
 546                         task can use this as a handle to delete the task later if\r
 547                         required.*/\r
 548                         *pxCreatedTask = ( xTaskHandle ) pxNewTCB;\r
 549                 }\r
 550 \r
 551                 if( xSchedulerRunning != pdFALSE )\r
 552                 {\r
 553                         /* If the created task is of a higher priority than the current task\r
 554                         then it should run now. */\r
 555                         if( pxCurrentTCB->uxPriority < uxPriority )\r
 556                         {\r
 557                                 taskYIELD();\r
 558                         }\r
 559                 }\r
 560         }\r
 561 \r
 562         return xReturn;\r
 563 }\r
 564 /*-----------------------------------------------------------*/\r
 565 \r
 566 #if ( INCLUDE_vTaskDelete == 1 )\r
 567 \r
 568         void vTaskDelete( xTaskHandle pxTaskToDelete )\r
 569         {\r
 570         tskTCB *pxTCB;\r
 571 \r
 572                 taskENTER_CRITICAL();\r
 573                 {\r
 574                         /* Ensure a yield is performed if the current task is being\r
 575                         deleted. */\r
 576                         if( pxTaskToDelete == pxCurrentTCB )\r
 577                         {\r
 578                                 pxTaskToDelete = NULL;\r
 579                         }\r
 580 \r
 581                         /* If null is passed in here then we are deleting ourselves. */\r
 582                         pxTCB = prvGetTCBFromHandle( pxTaskToDelete );\r
 583 \r
 584                         traceTASK_DELETE( pxTCB );\r
 585 \r
 586                         /* Remove task from the ready list and place in the     termination list.\r
 587                         This will stop the task from be scheduled.  The idle task will check\r
 588                         the termination list and free up any memory allocated by the\r
 589                         scheduler for the TCB and stack. */\r
 590                         vListRemove( &( pxTCB->xGenericListItem ) );\r
 591 \r
 592                         /* Is the task waiting on an event also? */                                                                                             \r
 593                         if( pxTCB->xEventListItem.pvContainer )\r
 594                         {\r
 595                                 vListRemove( &( pxTCB->xEventListItem ) );\r
 596                         }\r
 597 \r
 598                         vListInsertEnd( ( xList * ) &xTasksWaitingTermination, &( pxTCB->xGenericListItem ) );\r
 599 \r
 600                         /* Increment the ucTasksDeleted variable so the idle task knows\r
 601                         there is a task that has been deleted and that it should therefore\r
 602                         check the xTasksWaitingTermination list. */\r
 603                         ++uxTasksDeleted;\r
 604                 }\r
 605                 taskEXIT_CRITICAL();\r
 606 \r
 607                 /* Force a reschedule if we have just deleted the current task. */\r
 608                 if( xSchedulerRunning != pdFALSE )\r
 609                 {\r
 610                         if( ( void * ) pxTaskToDelete == NULL )\r
 611                         {\r
 612                                 taskYIELD();\r
 613                         }\r
 614                 }\r
 615         }\r
 616 \r
 617 #endif\r
 618 \r
 619 \r
 620 \r
 621 \r
 622 \r
 623 \r
 624 /*-----------------------------------------------------------\r
 625  * TASK CONTROL API documented in task.h\r
 626  *----------------------------------------------------------*/\r
 627 \r
 628 #if ( INCLUDE_vTaskDelayUntil == 1 )\r
 629 \r
 630         void vTaskDelayUntil( portTickType * const pxPreviousWakeTime, portTickType xTimeIncrement )\r
 631         {\r
 632         portTickType xTimeToWake;\r
 633         portBASE_TYPE xAlreadyYielded, xShouldDelay = pdFALSE;\r
 634 \r
 635                 vTaskSuspendAll();\r
 636                 {\r
 637                         /* Generate the tick time at which the task wants to wake. */\r
 638                         xTimeToWake = *pxPreviousWakeTime + xTimeIncrement;\r
 639 \r
 640                         if( xTickCount < *pxPreviousWakeTime )\r
 641                         {\r
 642                                 /* The tick count has overflowed since this function was\r
 643                                 lasted called.  In this case the only time we should ever\r
 644                                 actually delay is if the wake time has also     overflowed,\r
 645                                 and the wake time is greater than the tick time.  When this\r
 646                                 is the case it is as if neither time had overflowed. */\r
 647                                 if( ( xTimeToWake < *pxPreviousWakeTime ) && ( xTimeToWake > xTickCount ) )\r
 648                                 {\r
 649                                         xShouldDelay = pdTRUE;\r
 650                                 }\r
 651                         }\r
 652                         else\r
 653                         {\r
 654                                 /* The tick time has not overflowed.  In this case we will\r
 655                                 delay if either the wake time has overflowed, and/or the\r
 656                                 tick time is less than the wake time. */\r
 657                                 if( ( xTimeToWake < *pxPreviousWakeTime ) || ( xTimeToWake > xTickCount ) )\r
 658                                 {\r
 659                                         xShouldDelay = pdTRUE;\r
 660                                 }\r
 661                         }\r
 662 \r
 663                         /* Update the wake time ready for the next call. */\r
 664                         *pxPreviousWakeTime = xTimeToWake;\r
 665 \r
 666                         if( xShouldDelay )\r
 667                         {\r
 668                                 traceTASK_DELAY_UNTIL();\r
 669 \r
 670                                 /* We must remove ourselves from the ready list before adding\r
 671                                 ourselves to the blocked list as the same list item is used for\r
 672                                 both lists. */\r
 673                                 vListRemove( ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );\r
 674 \r
 675                                 /* The list item will be inserted in wake time order. */\r
 676                                 listSET_LIST_ITEM_VALUE( &( pxCurrentTCB->xGenericListItem ), xTimeToWake );\r
 677 \r
 678                                 if( xTimeToWake < xTickCount )\r
 679                                 {\r
 680                                         /* Wake time has overflowed.  Place this item in the\r
 681                                         overflow list. */\r
 682                                         vListInsert( ( xList * ) pxOverflowDelayedTaskList, ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );\r
 683                                 }\r
 684                                 else\r
 685                                 {\r
 686                                         /* The wake time has not overflowed, so we can use the\r
 687                                         current block list. */\r
 688                                         vListInsert( ( xList * ) pxDelayedTaskList, ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );\r
 689                                 }\r
 690                         }\r
 691                 }\r
 692                 xAlreadyYielded = xTaskResumeAll();\r
 693 \r
 694                 /* Force a reschedule if xTaskResumeAll has not already done so, we may\r
 695                 have put ourselves to sleep. */\r
 696                 if( !xAlreadyYielded )\r
 697                 {\r
 698                         taskYIELD();\r
 699                 }\r
 700         }       \r
 701         \r
 702 #endif\r
 703 /*-----------------------------------------------------------*/\r
 704 \r
 705 #if ( INCLUDE_vTaskDelay == 1 )\r
 706 \r
 707         void vTaskDelay( portTickType xTicksToDelay )\r
 708         {\r
 709         portTickType xTimeToWake;\r
 710         signed portBASE_TYPE xAlreadyYielded = pdFALSE;\r
 711 \r
 712                 /* A delay time of zero just forces a reschedule. */\r
 713                 if( xTicksToDelay > ( portTickType ) 0 )\r
 714                 {\r
 715                         vTaskSuspendAll();\r
 716                         {\r
 717                                 traceTASK_DELAY();\r
 718 \r
 719                                 /* A task that is removed from the event list while the\r
 720                                 scheduler is suspended will not get placed in the ready\r
 721                                 list or removed from the blocked list until the scheduler\r
 722                                 is resumed.\r
 723                                 \r
 724                                 This task cannot be in an event list as it is the currently\r
 725                                 executing task. */\r
 726 \r
 727                                 /* Calculate the time to wake - this may overflow but this is\r
 728                                 not a problem. */\r
 729                                 xTimeToWake = xTickCount + xTicksToDelay;\r
 730 \r
 731                                 /* We must remove ourselves from the ready list before adding\r
 732                                 ourselves to the blocked list as the same list item is used for\r
 733                                 both lists. */\r
 734                                 vListRemove( ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );\r
 735 \r
 736                                 /* The list item will be inserted in wake time order. */\r
 737                                 listSET_LIST_ITEM_VALUE( &( pxCurrentTCB->xGenericListItem ), xTimeToWake );\r
 738 \r
 739                                 if( xTimeToWake < xTickCount )\r
 740                                 {\r
 741                                         /* Wake time has overflowed.  Place this item in the\r
 742                                         overflow list. */\r
 743                                         vListInsert( ( xList * ) pxOverflowDelayedTaskList, ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );\r
 744                                 }\r
 745                                 else\r
 746                                 {\r
 747                                         /* The wake time has not overflowed, so we can use the\r
 748                                         current block list. */\r
 749                                         vListInsert( ( xList * ) pxDelayedTaskList, ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );\r
 750                                 }\r
 751                         }\r
 752                         xAlreadyYielded = xTaskResumeAll();\r
 753                 }\r
 754                 \r
 755                 /* Force a reschedule if xTaskResumeAll has not already done so, we may\r
 756                 have put ourselves to sleep. */\r
 757                 if( !xAlreadyYielded )\r
 758                 {\r
 759                         taskYIELD();\r
 760                 }\r
 761         }\r
 762         \r
 763 #endif\r
 764 /*-----------------------------------------------------------*/\r
 765 \r
 766 #if ( INCLUDE_uxTaskPriorityGet == 1 )\r
 767 \r
 768         unsigned portBASE_TYPE uxTaskPriorityGet( xTaskHandle pxTask )\r
 769         {\r
 770         tskTCB *pxTCB;\r
 771         unsigned portBASE_TYPE uxReturn;\r
 772 \r
 773                 taskENTER_CRITICAL();\r
 774                 {\r
 775                         /* If null is passed in here then we are changing the\r
 776                         priority of the calling function. */\r
 777                         pxTCB = prvGetTCBFromHandle( pxTask );\r
 778                         uxReturn = pxTCB->uxPriority;\r
 779                 }\r
 780                 taskEXIT_CRITICAL();\r
 781 \r
 782                 return uxReturn;\r
 783         }\r
 784 \r
 785 #endif\r
 786 /*-----------------------------------------------------------*/\r
 787 \r
 788 #if ( INCLUDE_vTaskPrioritySet == 1 )\r
 789 \r
 790         void vTaskPrioritySet( xTaskHandle pxTask, unsigned portBASE_TYPE uxNewPriority )\r
 791         {\r
 792         tskTCB *pxTCB;\r
 793         unsigned portBASE_TYPE uxCurrentPriority, xYieldRequired = pdFALSE;\r
 794 \r
 795                 /* Ensure the new priority is valid. */\r
 796                 if( uxNewPriority >= configMAX_PRIORITIES )\r
 797                 {\r
 798                         uxNewPriority = configMAX_PRIORITIES - 1;\r
 799                 }\r
 800 \r
 801                 taskENTER_CRITICAL();\r
 802                 {\r
 803                         /* If null is passed in here then we are changing the\r
 804                         priority of the calling function. */\r
 805                         pxTCB = prvGetTCBFromHandle( pxTask );\r
 806                         \r
 807                         traceTASK_PRIORITY_SET( pxTask, uxNewPriority );\r
 808 \r
 809                         #if ( configUSE_MUTEXES == 1 )\r
 810                         {\r
 811                                 uxCurrentPriority = pxTCB->uxBasePriority;\r
 812                         }\r
 813                         #else\r
 814                         {\r
 815                                 uxCurrentPriority = pxTCB->uxPriority;\r
 816                         }\r
 817                         #endif\r
 818 \r
 819                         if( uxCurrentPriority != uxNewPriority )\r
 820                         {\r
 821                                 /* The priority change may have readied a task of higher\r
 822                                 priority than the calling task. */\r
 823                                 if( uxNewPriority > uxCurrentPriority )\r
 824                                 {\r
 825                                         if( pxTask != NULL )\r
 826                                         {\r
 827                                                 /* The priority of another task is being raised.  If we\r
 828                                                 were raising the priority of the currently running task\r
 829                                                 there would be no need to switch as it must have already\r
 830                                                 been the highest priority task. */\r
 831                                                 xYieldRequired = pdTRUE;\r
 832                                         }\r
 833                                 }\r
 834                                 else if( pxTask == NULL )\r
 835                                 {\r
 836                                         /* Setting our own priority down means there may now be another\r
 837                                         task of higher priority that is ready to execute. */\r
 838                                         xYieldRequired = pdTRUE;\r
 839                                 }\r
 840                         \r
 841                                 \r
 842 \r
 843                                 #if ( configUSE_MUTEXES == 1 )\r
 844                                 {\r
 845                                         /* Only change the priority being used if the task is not\r
 846                                         currently using an inherited priority. */\r
 847                                         if( pxTCB->uxBasePriority == pxTCB->uxPriority )\r
 848                                         {\r
 849                                                 pxTCB->uxPriority = uxNewPriority;\r
 850                                         }\r
 851                                         \r
 852                                         /* The base priority gets set whatever. */\r
 853                                         pxTCB->uxBasePriority = uxNewPriority;                                  \r
 854                                 }\r
 855                                 #else\r
 856                                 {\r
 857                                         pxTCB->uxPriority = uxNewPriority;\r
 858                                 }\r
 859                                 #endif\r
 860 \r
 861                                 listSET_LIST_ITEM_VALUE( &( pxTCB->xEventListItem ), ( configMAX_PRIORITIES - ( portTickType ) uxNewPriority ) );\r
 862 \r
 863                                 /* If the task is in the blocked or suspended list we need do\r
 864                                 nothing more than change it's priority variable. However, if\r
 865                                 the task is in a ready list it needs to be removed and placed\r
 866                                 in the queue appropriate to its new priority. */\r
 867                                 if( listIS_CONTAINED_WITHIN( &( pxReadyTasksLists[ uxCurrentPriority ] ), &( pxTCB->xGenericListItem ) ) )\r
 868                                 {\r
 869                                         /* The task is currently in its ready list - remove before adding\r
 870                                         it to it's new ready list.  As we are in a critical section we\r
 871                                         can do this even if the scheduler is suspended. */\r
 872                                         vListRemove( &( pxTCB->xGenericListItem ) );\r
 873                                         prvAddTaskToReadyQueue( pxTCB );\r
 874                                 }                       \r
 875                                 \r
 876                                 if( xYieldRequired == pdTRUE )\r
 877                                 {\r
 878                                         taskYIELD();\r
 879                                 }                               \r
 880                         }\r
 881                 }\r
 882                 taskEXIT_CRITICAL();\r
 883         }\r
 884 \r
 885 #endif\r
 886 /*-----------------------------------------------------------*/\r
 887 \r
 888 #if ( INCLUDE_vTaskSuspend == 1 )\r
 889 \r
 890         void vTaskSuspend( xTaskHandle pxTaskToSuspend )\r
 891         {\r
 892         tskTCB *pxTCB;\r
 893 \r
 894                 taskENTER_CRITICAL();\r
 895                 {\r
 896                         /* Ensure a yield is performed if the current task is being\r
 897                         suspended. */\r
 898                         if( pxTaskToSuspend == pxCurrentTCB )\r
 899                         {\r
 900                                 pxTaskToSuspend = NULL;\r
 901                         }\r
 902 \r
 903                         /* If null is passed in here then we are suspending ourselves. */\r
 904                         pxTCB = prvGetTCBFromHandle( pxTaskToSuspend );\r
 905 \r
 906                         traceTASK_SUSPEND( pxTaskToSuspend );\r
 907 \r
 908                         /* Remove task from the ready/delayed list and place in the     suspended list. */\r
 909                         vListRemove( &( pxTCB->xGenericListItem ) );\r
 910 \r
 911                         /* Is the task waiting on an event also? */                                                                                             \r
 912                         if( pxTCB->xEventListItem.pvContainer )\r
 913                         {\r
 914                                 vListRemove( &( pxTCB->xEventListItem ) );\r
 915                         }\r
 916 \r
 917                         vListInsertEnd( ( xList * ) &xSuspendedTaskList, &( pxTCB->xGenericListItem ) );\r
 918                 }\r
 919                 taskEXIT_CRITICAL();\r
 920 \r
 921                 /* We may have just suspended the current task. */\r
 922                 if( ( void * ) pxTaskToSuspend == NULL )\r
 923                 {\r
 924                         taskYIELD();\r
 925                 }\r
 926         }\r
 927 \r
 928 #endif\r
 929 /*-----------------------------------------------------------*/\r
 930 \r
 931 #if ( INCLUDE_vTaskSuspend == 1 )\r
 932 \r
 933         static portBASE_TYPE prvIsTaskSuspended( const tskTCB * const pxTCB )\r
 934         {\r
 935         portBASE_TYPE xReturn = pdFALSE;\r
 936 \r
 937                 /* Is the task we are attempting to resume actually in the\r
 938                 suspended list? */\r
 939                 if( listIS_CONTAINED_WITHIN( &xSuspendedTaskList, &( pxTCB->xGenericListItem ) ) != pdFALSE )\r
 940                 {\r
 941                         /* Has the task already been resumed from within an ISR? */\r
 942                         if( listIS_CONTAINED_WITHIN( &xPendingReadyList, &( pxTCB->xEventListItem ) ) != pdTRUE )\r
 943                         {                       \r
 944                                 /* Is it in the suspended list because it is in the\r
 945                                 Suspended state?  It is possible to be in the suspended\r
 946                                 list because it is blocked on a task with no timeout\r
 947                                 specified. */\r
 948                                 if( listIS_CONTAINED_WITHIN( NULL, &( pxTCB->xEventListItem ) ) == pdTRUE )\r
 949                                 {\r
 950                                         xReturn = pdTRUE;\r
 951                                 }\r
 952                         }\r
 953                 }\r
 954 \r
 955                 return xReturn;\r
 956         }\r
 957 \r
 958 #endif\r
 959 /*-----------------------------------------------------------*/\r
 960 \r
 961 #if ( INCLUDE_vTaskSuspend == 1 )\r
 962 \r
 963         void vTaskResume( xTaskHandle pxTaskToResume )\r
 964         {\r
 965         tskTCB *pxTCB;\r
 966 \r
 967                 /* Remove the task from whichever list it is currently in, and place\r
 968                 it in the ready list. */\r
 969                 pxTCB = ( tskTCB * ) pxTaskToResume;\r
 970 \r
 971                 /* The parameter cannot be NULL as it is impossible to resume the\r
 972                 currently executing task. */\r
 973                 if( pxTCB != NULL )\r
 974                 {\r
 975                         taskENTER_CRITICAL();\r
 976                         {\r
 977                                 if( prvIsTaskSuspended( pxTCB ) == pdTRUE )\r
 978                                 {\r
 979                                         traceTASK_RESUME( pxTCB );\r
 980 \r
 981                                         /* As we are in a critical section we can access the ready\r
 982                                         lists even if the scheduler is suspended. */\r
 983                                         vListRemove(  &( pxTCB->xGenericListItem ) );\r
 984                                         prvAddTaskToReadyQueue( pxTCB );\r
 985 \r
 986                                         /* We may have just resumed a higher priority task. */\r
 987                                         if( pxTCB->uxPriority >= pxCurrentTCB->uxPriority )\r
 988                                         {\r
 989                                                 /* This yield may not cause the task just resumed to run, but\r
 990                                                 will leave the lists in the correct state for the next yield. */\r
 991                                                 taskYIELD();\r
 992                                         }\r
 993                                 }\r
 994                         }\r
 995                         taskEXIT_CRITICAL();\r
 996                 }\r
 997         }\r
 998 \r
 999 #endif\r
1000 \r
1001 /*-----------------------------------------------------------*/\r
1002 \r
1003 #if ( ( INCLUDE_xTaskResumeFromISR == 1 ) && ( INCLUDE_vTaskSuspend == 1 ) )\r
1004 \r
1005         portBASE_TYPE xTaskResumeFromISR( xTaskHandle pxTaskToResume )\r
1006         {\r
1007         portBASE_TYPE xYieldRequired = pdFALSE;\r
1008         tskTCB *pxTCB;\r
1009 \r
1010                 pxTCB = ( tskTCB * ) pxTaskToResume;\r
1011 \r
1012                 if( prvIsTaskSuspended( pxTCB ) == pdTRUE )\r
1013                 {\r
1014                         traceTASK_RESUME_FROM_ISR( pxTCB );\r
1015 \r
1016                         if( uxSchedulerSuspended == ( unsigned portBASE_TYPE ) pdFALSE )\r
1017                         {\r
1018                                 xYieldRequired = ( pxTCB->uxPriority >= pxCurrentTCB->uxPriority );\r
1019                                 vListRemove(  &( pxTCB->xGenericListItem ) );   \r
1020                                 prvAddTaskToReadyQueue( pxTCB );\r
1021                         }\r
1022                         else\r
1023                         {\r
1024                                 /* We cannot access the delayed or ready lists, so will hold this\r
1025                                 task pending until the scheduler is resumed, at which point a\r
1026                                 yield will be performed if necessary. */\r
1027                                 vListInsertEnd( ( xList * ) &( xPendingReadyList ), &( pxTCB->xEventListItem ) );\r
1028                         }\r
1029                 }\r
1030 \r
1031                 return xYieldRequired;\r
1032         }\r
1033 \r
1034 #endif\r
1035 \r
1036 \r
1037 \r
1038 \r
1039 /*-----------------------------------------------------------\r
1040  * PUBLIC SCHEDULER CONTROL documented in task.h\r
1041  *----------------------------------------------------------*/\r
1042 \r
1043 \r
1044 void vTaskStartScheduler( void )\r
1045 {\r
1046 portBASE_TYPE xReturn;\r
1047 \r
1048         /* Add the idle task at the lowest priority. */\r
1049         xReturn = xTaskCreate( prvIdleTask, ( signed portCHAR * ) "IDLE", tskIDLE_STACK_SIZE, ( void * ) NULL, tskIDLE_PRIORITY, ( xTaskHandle * ) NULL );\r
1050 \r
1051         if( xReturn == pdPASS )\r
1052         {\r
1053                 /* Interrupts are turned off here, to ensure a tick does not occur\r
1054                 before or during the call to xPortStartScheduler().  The stacks of\r
1055                 the created tasks contain a status word with interrupts switched on\r
1056                 so interrupts will automatically get re-enabled when the first task\r
1057                 starts to run.\r
1058                 \r
1059                 STEPPING THROUGH HERE USING A DEBUGGER CAN CAUSE BIG PROBLEMS IF THE\r
1060                 DEBUGGER ALLOWS INTERRUPTS TO BE PROCESSED. */\r
1061                 portDISABLE_INTERRUPTS();\r
1062 \r
1063                 xSchedulerRunning = pdTRUE;\r
1064                 xTickCount = ( portTickType ) 0;\r
1065 \r
1066                 /* Setting up the timer tick is hardware specific and thus in the\r
1067                 portable interface. */\r
1068                 if( xPortStartScheduler() )\r
1069                 {\r
1070                         /* Should not reach here as if the scheduler is running the\r
1071                         function will not return. */\r
1072                 }\r
1073                 else\r
1074                 {\r
1075                         /* Should only reach here if a task calls xTaskEndScheduler(). */\r
1076                 }\r
1077         }\r
1078 }\r
1079 /*-----------------------------------------------------------*/\r
1080 \r
1081 void vTaskEndScheduler( void )\r
1082 {\r
1083         /* Stop the scheduler interrupts and call the portable scheduler end\r
1084         routine so the original ISRs can be restored if necessary.  The port\r
1085         layer must ensure interrupts enable     bit is left in the correct state. */\r
1086         portDISABLE_INTERRUPTS();\r
1087         xSchedulerRunning = pdFALSE;\r
1088         vPortEndScheduler();\r
1089 }\r
1090 /*----------------------------------------------------------*/\r
1091 \r
1092 void vTaskSuspendAll( void )\r
1093 {\r
1094         portENTER_CRITICAL();\r
1095                 ++uxSchedulerSuspended;\r
1096         portEXIT_CRITICAL();\r
1097 }\r
1098 /*----------------------------------------------------------*/\r
1099 \r
1100 signed portBASE_TYPE xTaskResumeAll( void )\r
1101 {\r
1102 register tskTCB *pxTCB;\r
1103 signed portBASE_TYPE xAlreadyYielded = pdFALSE;\r
1104 \r
1105         /* It is possible that an ISR caused a task to be removed from an event\r
1106         list while the scheduler was suspended.  If this was the case then the\r
1107         removed task will have been added to the xPendingReadyList.  Once the\r
1108         scheduler has been resumed it is safe to move all the pending ready\r
1109         tasks from this list into their appropriate ready list. */\r
1110         portENTER_CRITICAL();\r
1111         {\r
1112                 --uxSchedulerSuspended;\r
1113 \r
1114                 if( uxSchedulerSuspended == ( unsigned portBASE_TYPE ) pdFALSE )\r
1115                 {                       \r
1116                         if( uxCurrentNumberOfTasks > ( unsigned portBASE_TYPE ) 0 )\r
1117                         {\r
1118                                 portBASE_TYPE xYieldRequired = pdFALSE;\r
1119                                 \r
1120                                 /* Move any readied tasks from the pending list into the\r
1121                                 appropriate ready list. */\r
1122                                 while( ( pxTCB = ( tskTCB * ) listGET_OWNER_OF_HEAD_ENTRY(  ( ( xList * ) &xPendingReadyList ) ) ) != NULL )\r
1123                                 {\r
1124                                         vListRemove( &( pxTCB->xEventListItem ) );\r
1125                                         vListRemove( &( pxTCB->xGenericListItem ) );\r
1126                                         prvAddTaskToReadyQueue( pxTCB );\r
1127                                         \r
1128                                         /* If we have moved a task that has a priority higher than\r
1129                                         the current task then we should yield. */\r
1130                                         if( pxTCB->uxPriority >= pxCurrentTCB->uxPriority )\r
1131                                         {\r
1132                                                 xYieldRequired = pdTRUE;\r
1133                                         }\r
1134                                 }\r
1135 \r
1136                                 /* If any ticks occurred while the scheduler was suspended then\r
1137                                 they should be processed now.  This ensures the tick count does not\r
1138                                 slip, and that any delayed tasks are resumed at the correct time. */\r
1139                                 if( uxMissedTicks > ( unsigned portBASE_TYPE ) 0 )\r
1140                                 {\r
1141                                         while( uxMissedTicks > ( unsigned portBASE_TYPE ) 0 )\r
1142                                         {\r
1143                                                 vTaskIncrementTick();\r
1144                                                 --uxMissedTicks;\r
1145                                         }\r
1146 \r
1147                                         /* As we have processed some ticks it is appropriate to yield\r
1148                                         to ensure the highest priority task that is ready to run is\r
1149                                         the task actually running. */\r
1150                                         #if configUSE_PREEMPTION == 1\r
1151                                         {\r
1152                                                 xYieldRequired = pdTRUE;\r
1153                                         }\r
1154                                         #endif\r
1155                                 }\r
1156                                 \r
1157                                 if( ( xYieldRequired == pdTRUE ) || ( xMissedYield == pdTRUE ) )\r
1158                                 {\r
1159                                         xAlreadyYielded = pdTRUE;\r
1160                                         xMissedYield = pdFALSE;\r
1161                                         taskYIELD();\r
1162                                 }\r
1163                         }\r
1164                 }\r
1165         }\r
1166         portEXIT_CRITICAL();\r
1167 \r
1168         return xAlreadyYielded;\r
1169 }\r
1170 \r
1171 \r
1172 \r
1173 \r
1174 \r
1175 \r
1176 /*-----------------------------------------------------------\r
1177  * PUBLIC TASK UTILITIES documented in task.h\r
1178  *----------------------------------------------------------*/\r
1179 \r
1180 \r
1181 \r
1182 portTickType xTaskGetTickCount( void )\r
1183 {\r
1184 portTickType xTicks;\r
1185 \r
1186         /* Critical section required if running on a 16 bit processor. */\r
1187         taskENTER_CRITICAL();\r
1188         {\r
1189                 xTicks = xTickCount;\r
1190         }\r
1191         taskEXIT_CRITICAL();\r
1192 \r
1193         return xTicks;\r
1194 }\r
1195 /*-----------------------------------------------------------*/\r
1196 \r
1197 unsigned portBASE_TYPE uxTaskGetNumberOfTasks( void )\r
1198 {\r
1199 unsigned portBASE_TYPE uxNumberOfTasks;\r
1200 \r
1201         taskENTER_CRITICAL();\r
1202                 uxNumberOfTasks = uxCurrentNumberOfTasks;\r
1203         taskEXIT_CRITICAL();\r
1204 \r
1205         return uxNumberOfTasks;\r
1206 }\r
1207 /*-----------------------------------------------------------*/\r
1208 \r
1209 #if ( ( configUSE_TRACE_FACILITY == 1 ) && ( INCLUDE_vTaskDelete == 1 ) && ( INCLUDE_vTaskSuspend == 1 ) )\r
1210 \r
1211         void vTaskList( signed portCHAR *pcWriteBuffer )\r
1212         {\r
1213         unsigned portBASE_TYPE uxQueue;\r
1214 \r
1215                 /* This is a VERY costly function that should be used for debug only.\r
1216                 It leaves interrupts disabled for a LONG time. */\r
1217 \r
1218         vTaskSuspendAll();\r
1219                 {\r
1220                         /* Run through all the lists that could potentially contain a TCB and\r
1221                         report the task name, state and stack high water mark. */\r
1222 \r
1223                         pcWriteBuffer[ 0 ] = ( signed portCHAR ) 0x00;\r
1224                         strcat( ( portCHAR * ) pcWriteBuffer, ( const portCHAR * ) "\r\n" );\r
1225 \r
1226                         uxQueue = uxTopUsedPriority + 1;\r
1227 \r
1228                         do\r
1229                         {\r
1230                                 uxQueue--;\r
1231 \r
1232                                 if( !listLIST_IS_EMPTY( &( pxReadyTasksLists[ uxQueue ] ) ) )\r
1233                                 {\r
1234                                         prvListTaskWithinSingleList( pcWriteBuffer, ( xList * ) &( pxReadyTasksLists[ uxQueue ] ), tskREADY_CHAR );                     \r
1235                                 }\r
1236                         }while( uxQueue > ( unsigned portSHORT ) tskIDLE_PRIORITY );\r
1237 \r
1238                         if( !listLIST_IS_EMPTY( pxDelayedTaskList ) )\r
1239                         {\r
1240                                 prvListTaskWithinSingleList( pcWriteBuffer, ( xList * ) pxDelayedTaskList, tskBLOCKED_CHAR );\r
1241                         }\r
1242 \r
1243                         if( !listLIST_IS_EMPTY( pxOverflowDelayedTaskList ) )\r
1244                         {\r
1245                                 prvListTaskWithinSingleList( pcWriteBuffer, ( xList * ) pxOverflowDelayedTaskList, tskBLOCKED_CHAR );\r
1246                         }\r
1247 \r
1248                         if( !listLIST_IS_EMPTY( &xTasksWaitingTermination ) )\r
1249                         {\r
1250                                 prvListTaskWithinSingleList( pcWriteBuffer, ( xList * ) &xTasksWaitingTermination, tskDELETED_CHAR );\r
1251                         }\r
1252 \r
1253                         if( !listLIST_IS_EMPTY( &xSuspendedTaskList ) )\r
1254                         {\r
1255                                 prvListTaskWithinSingleList( pcWriteBuffer, ( xList * ) &xSuspendedTaskList, tskSUSPENDED_CHAR );\r
1256                         }\r
1257                 }\r
1258         xTaskResumeAll();\r
1259         }\r
1260 \r
1261 #endif\r
1262 /*----------------------------------------------------------*/\r
1263 \r
1264 #if ( configUSE_TRACE_FACILITY == 1 )\r
1265 \r
1266         void vTaskStartTrace( signed portCHAR * pcBuffer, unsigned portLONG ulBufferSize )\r
1267         {\r
1268                 portENTER_CRITICAL();\r
1269                 {\r
1270                         pcTraceBuffer = ( signed portCHAR * )pcBuffer;\r
1271                         pcTraceBufferStart = pcBuffer;\r
1272                         pcTraceBufferEnd = pcBuffer + ( ulBufferSize - tskSIZE_OF_EACH_TRACE_LINE );\r
1273                         xTracing = pdTRUE;\r
1274                 }\r
1275                 portEXIT_CRITICAL();\r
1276         }\r
1277 \r
1278 #endif\r
1279 /*----------------------------------------------------------*/\r
1280 \r
1281 #if ( configUSE_TRACE_FACILITY == 1 )\r
1282 \r
1283         unsigned portLONG ulTaskEndTrace( void )\r
1284         {\r
1285         unsigned portLONG ulBufferLength;\r
1286 \r
1287                 portENTER_CRITICAL();\r
1288                         xTracing = pdFALSE;\r
1289                 portEXIT_CRITICAL();\r
1290 \r
1291                 ulBufferLength = ( unsigned portLONG ) ( pcTraceBuffer - pcTraceBufferStart );\r
1292 \r
1293                 return ulBufferLength;\r
1294         }\r
1295 \r
1296 #endif\r
1297 \r
1298 \r
1299 \r
1300 /*-----------------------------------------------------------\r
1301  * SCHEDULER INTERNALS AVAILABLE FOR PORTING PURPOSES\r
1302  * documented in task.h\r
1303  *----------------------------------------------------------*/\r
1304 \r
1305 \r
1306 inline void vTaskIncrementTick( void )\r
1307 {\r
1308         /* Called by the portable layer each time a tick interrupt occurs.\r
1309         Increments the tick then checks to see if the new tick value will cause any\r
1310         tasks to be unblocked. */\r
1311         if( uxSchedulerSuspended == ( unsigned portBASE_TYPE ) pdFALSE )\r
1312         {\r
1313                 ++xTickCount;\r
1314                 if( xTickCount == ( portTickType ) 0 )\r
1315                 {\r
1316                         xList *pxTemp;\r
1317 \r
1318                         /* Tick count has overflowed so we need to swap the delay lists.\r
1319                         If there are any items in pxDelayedTaskList here then there is\r
1320                         an error! */\r
1321                         pxTemp = pxDelayedTaskList;\r
1322                         pxDelayedTaskList = pxOverflowDelayedTaskList;\r
1323                         pxOverflowDelayedTaskList = pxTemp;\r
1324             xNumOfOverflows++;\r
1325                 }\r
1326 \r
1327                 /* See if this tick has made a timeout expire. */\r
1328                 prvCheckDelayedTasks();\r
1329         }\r
1330         else\r
1331         {\r
1332                 ++uxMissedTicks;\r
1333 \r
1334                 /* The tick hook gets called at regular intervals, even if the\r
1335                 scheduler is locked. */\r
1336                 #if ( configUSE_TICK_HOOK == 1 )\r
1337                 {\r
1338                         extern void vApplicationTickHook( void );\r
1339 \r
1340                         vApplicationTickHook();\r
1341                 }\r
1342                 #endif\r
1343         }\r
1344 \r
1345         #if ( configUSE_TICK_HOOK == 1 )\r
1346         {\r
1347                 extern void vApplicationTickHook( void );\r
1348 \r
1349                 /* Guard against the tick hook being called when the missed tick\r
1350                 count is being unwound (when the scheduler is being unlocked. */\r
1351                 if( uxMissedTicks == 0 )\r
1352                 {\r
1353                         vApplicationTickHook();\r
1354                 }\r
1355         }\r
1356         #endif\r
1357 \r
1358         traceTASK_INCREMENT_TICK( xTickCount );\r
1359 }\r
1360 /*-----------------------------------------------------------*/\r
1361 \r
1362 #if ( ( INCLUDE_vTaskCleanUpResources == 1 ) && ( INCLUDE_vTaskSuspend == 1 ) )\r
1363 \r
1364         void vTaskCleanUpResources( void )\r
1365         {\r
1366         unsigned portSHORT usQueue;\r
1367         volatile tskTCB *pxTCB;\r
1368 \r
1369                 usQueue = ( unsigned portSHORT ) uxTopUsedPriority + ( unsigned portSHORT ) 1;\r
1370 \r
1371                 /* Remove any TCB's from the ready queues. */\r
1372                 do\r
1373                 {\r
1374                         usQueue--;\r
1375 \r
1376                         while( !listLIST_IS_EMPTY( &( pxReadyTasksLists[ usQueue ] ) ) )\r
1377                         {\r
1378                                 listGET_OWNER_OF_NEXT_ENTRY( pxTCB, &( pxReadyTasksLists[ usQueue ] ) );\r
1379                                 vListRemove( ( xListItem * ) &( pxTCB->xGenericListItem ) );\r
1380 \r
1381                                 prvDeleteTCB( ( tskTCB * ) pxTCB );\r
1382                         }\r
1383                 }while( usQueue > ( unsigned portSHORT ) tskIDLE_PRIORITY );\r
1384 \r
1385                 /* Remove any TCB's from the delayed queue. */\r
1386                 while( !listLIST_IS_EMPTY( &xDelayedTaskList1 ) )\r
1387                 {\r
1388                         listGET_OWNER_OF_NEXT_ENTRY( pxTCB, &xDelayedTaskList1 );\r
1389                         vListRemove( ( xListItem * ) &( pxTCB->xGenericListItem ) );\r
1390 \r
1391                         prvDeleteTCB( ( tskTCB * ) pxTCB );\r
1392                 }\r
1393 \r
1394                 /* Remove any TCB's from the overflow delayed queue. */\r
1395                 while( !listLIST_IS_EMPTY( &xDelayedTaskList2 ) )\r
1396                 {\r
1397                         listGET_OWNER_OF_NEXT_ENTRY( pxTCB, &xDelayedTaskList2 );\r
1398                         vListRemove( ( xListItem * ) &( pxTCB->xGenericListItem ) );\r
1399 \r
1400                         prvDeleteTCB( ( tskTCB * ) pxTCB );\r
1401                 }\r
1402 \r
1403                 while( !listLIST_IS_EMPTY( &xSuspendedTaskList ) )\r
1404                 {\r
1405                         listGET_OWNER_OF_NEXT_ENTRY( pxTCB, &xSuspendedTaskList );\r
1406                         vListRemove( ( xListItem * ) &( pxTCB->xGenericListItem ) );\r
1407 \r
1408                         prvDeleteTCB( ( tskTCB * ) pxTCB );\r
1409                 }               \r
1410         }\r
1411 \r
1412 #endif\r
1413 /*-----------------------------------------------------------*/\r
1414 \r
1415 void vTaskSwitchContext( void )\r
1416 {\r
1417         traceTASK_SWITCHED_OUT();\r
1418 \r
1419         if( uxSchedulerSuspended != ( unsigned portBASE_TYPE ) pdFALSE )\r
1420         {\r
1421                 /* The scheduler is currently suspended - do not allow a context\r
1422                 switch. */\r
1423                 xMissedYield = pdTRUE;\r
1424                 return;\r
1425         }\r
1426 \r
1427         taskCHECK_FOR_STACK_OVERFLOW();\r
1428 \r
1429         /* Find the highest priority queue that contains ready tasks. */\r
1430         while( listLIST_IS_EMPTY( &( pxReadyTasksLists[ uxTopReadyPriority ] ) ) )\r
1431         {\r
1432                 --uxTopReadyPriority;\r
1433         }\r
1434 \r
1435         /* listGET_OWNER_OF_NEXT_ENTRY walks through the list, so the tasks of the\r
1436         same priority get an equal share of the processor time. */\r
1437         listGET_OWNER_OF_NEXT_ENTRY( pxCurrentTCB, &( pxReadyTasksLists[ uxTopReadyPriority ] ) );\r
1438 \r
1439         traceTASK_SWITCHED_IN();\r
1440         vWriteTraceToBuffer();\r
1441 }\r
1442 /*-----------------------------------------------------------*/\r
1443 \r
1444 void vTaskPlaceOnEventList( const xList * const pxEventList, portTickType xTicksToWait )\r
1445 {\r
1446 portTickType xTimeToWake;\r
1447 \r
1448         /* THIS FUNCTION MUST BE CALLED WITH INTERRUPTS DISABLED OR THE\r
1449         SCHEDULER SUSPENDED. */\r
1450 \r
1451         /* Place the event list item of the TCB in the appropriate event list.\r
1452         This is placed in the list in priority order so the highest priority task\r
1453         is the first to be woken by the event. */\r
1454         vListInsert( ( xList * ) pxEventList, ( xListItem * ) &( pxCurrentTCB->xEventListItem ) );\r
1455 \r
1456         /* We must remove ourselves from the ready list before adding ourselves\r
1457         to the blocked list as the same list item is used for both lists.  We have\r
1458         exclusive access to the ready lists as the scheduler is locked. */\r
1459         vListRemove( ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );\r
1460 \r
1461 \r
1462         #if ( INCLUDE_vTaskSuspend == 1 )\r
1463         {                       \r
1464                 if( xTicksToWait == portMAX_DELAY )\r
1465                 {\r
1466                         /* Add ourselves to the suspended task list instead of a delayed task\r
1467                         list to ensure we are not woken by a timing event.  We will block\r
1468                         indefinitely. */\r
1469                         vListInsertEnd( ( xList * ) &xSuspendedTaskList, ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );\r
1470                 }\r
1471                 else\r
1472                 {\r
1473                         /* Calculate the time at which the task should be woken if the event does\r
1474                         not occur.  This may overflow but this doesn't matter. */\r
1475                         xTimeToWake = xTickCount + xTicksToWait;\r
1476                 \r
1477                         listSET_LIST_ITEM_VALUE( &( pxCurrentTCB->xGenericListItem ), xTimeToWake );\r
1478                 \r
1479                         if( xTimeToWake < xTickCount )\r
1480                         {\r
1481                                 /* Wake time has overflowed.  Place this item in the overflow list. */\r
1482                                 vListInsert( ( xList * ) pxOverflowDelayedTaskList, ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );\r
1483                         }\r
1484                         else\r
1485                         {\r
1486                                 /* The wake time has not overflowed, so we can use the current block list. */\r
1487                                 vListInsert( ( xList * ) pxDelayedTaskList, ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );\r
1488                         }\r
1489                 }\r
1490         }\r
1491         #else\r
1492         {\r
1493                         /* Calculate the time at which the task should be woken if the event does\r
1494                         not occur.  This may overflow but this doesn't matter. */\r
1495                         xTimeToWake = xTickCount + xTicksToWait;\r
1496                 \r
1497                         listSET_LIST_ITEM_VALUE( &( pxCurrentTCB->xGenericListItem ), xTimeToWake );\r
1498                 \r
1499                         if( xTimeToWake < xTickCount )\r
1500                         {\r
1501                                 /* Wake time has overflowed.  Place this item in the overflow list. */\r
1502                                 vListInsert( ( xList * ) pxOverflowDelayedTaskList, ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );\r
1503                         }\r
1504                         else\r
1505                         {\r
1506                                 /* The wake time has not overflowed, so we can use the current block list. */\r
1507                                 vListInsert( ( xList * ) pxDelayedTaskList, ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );\r
1508                         }\r
1509         }\r
1510         #endif\r
1511 }\r
1512 /*-----------------------------------------------------------*/\r
1513 \r
1514 signed portBASE_TYPE xTaskRemoveFromEventList( const xList * const pxEventList )\r
1515 {\r
1516 tskTCB *pxUnblockedTCB;\r
1517 portBASE_TYPE xReturn;\r
1518 \r
1519         /* THIS FUNCTION MUST BE CALLED WITH INTERRUPTS DISABLED OR THE\r
1520         SCHEDULER SUSPENDED.  It can also be called from within an ISR. */\r
1521 \r
1522         /* The event list is sorted in priority order, so we can remove the\r
1523         first in the list, remove the TCB from the delayed list, and add\r
1524         it to the ready list.\r
1525         \r
1526         If an event is for a queue that is locked then this function will never\r
1527         get called - the lock count on the queue will get modified instead.  This\r
1528         means we can always expect exclusive access to the event list here. */\r
1529         pxUnblockedTCB = ( tskTCB * ) listGET_OWNER_OF_HEAD_ENTRY( pxEventList );\r
1530         vListRemove( &( pxUnblockedTCB->xEventListItem ) );\r
1531 \r
1532         if( uxSchedulerSuspended == ( unsigned portBASE_TYPE ) pdFALSE )\r
1533         {\r
1534                 vListRemove( &( pxUnblockedTCB->xGenericListItem ) );\r
1535                 prvAddTaskToReadyQueue( pxUnblockedTCB );\r
1536         }\r
1537         else\r
1538         {\r
1539                 /* We cannot access the delayed or ready lists, so will hold this\r
1540                 task pending until the scheduler is resumed. */\r
1541                 vListInsertEnd( ( xList * ) &( xPendingReadyList ), &( pxUnblockedTCB->xEventListItem ) );\r
1542         }\r
1543 \r
1544         if( pxUnblockedTCB->uxPriority >= pxCurrentTCB->uxPriority )\r
1545         {\r
1546                 /* Return true if the task removed from the event list has\r
1547                 a higher priority than the calling task.  This allows\r
1548                 the calling task to know if it should force a context\r
1549                 switch now. */\r
1550                 xReturn = pdTRUE;\r
1551         }\r
1552         else\r
1553         {\r
1554                 xReturn = pdFALSE;\r
1555         }\r
1556 \r
1557         return xReturn;\r
1558 }\r
1559 /*-----------------------------------------------------------*/\r
1560 \r
1561 void vTaskSetTimeOutState( xTimeOutType * const pxTimeOut )\r
1562 {\r
1563     pxTimeOut->xOverflowCount = xNumOfOverflows;\r
1564     pxTimeOut->xTimeOnEntering = xTickCount;\r
1565 }\r
1566 /*-----------------------------------------------------------*/\r
1567 \r
1568 portBASE_TYPE xTaskCheckForTimeOut( xTimeOutType * const pxTimeOut, portTickType * const pxTicksToWait )\r
1569 {\r
1570 portBASE_TYPE xReturn;\r
1571 \r
1572         portENTER_CRITICAL();\r
1573         {\r
1574                 #if ( INCLUDE_vTaskSuspend == 1 )\r
1575                         /* If INCLUDE_vTaskSuspend is set to 1 and the block time specified is\r
1576                         the maximum block time then the task should block indefinitely, and\r
1577                         therefore never time out. */\r
1578                         if( *pxTicksToWait == portMAX_DELAY )\r
1579                         {\r
1580                                 xReturn = pdFALSE;\r
1581                         }\r
1582                         else /* We are not blocking indefinitely, perform the checks below. */\r
1583                 #endif\r
1584 \r
1585                 if( ( xNumOfOverflows != pxTimeOut->xOverflowCount ) && ( xTickCount >= pxTimeOut->xTimeOnEntering ) )\r
1586                 {\r
1587                         /* The tick count is greater than the time at which vTaskSetTimeout()\r
1588                         was called, but has also overflowed since vTaskSetTimeOut() was called.\r
1589                         It must have wrapped all the way around and gone past us again. This\r
1590                         passed since vTaskSetTimeout() was called. */\r
1591                         xReturn = pdTRUE;\r
1592                 }\r
1593                 else if( ( xTickCount - pxTimeOut->xTimeOnEntering ) < *pxTicksToWait )\r
1594                 {\r
1595                         /* Not a genuine timeout. Adjust parameters for time remaining. */\r
1596                         *pxTicksToWait -= ( xTickCount - pxTimeOut->xTimeOnEntering );\r
1597                         vTaskSetTimeOutState( pxTimeOut );\r
1598                         xReturn = pdFALSE;\r
1599                 }\r
1600                 else\r
1601                 {\r
1602                         xReturn = pdTRUE;\r
1603                 }\r
1604         }\r
1605         portEXIT_CRITICAL();\r
1606 \r
1607     return xReturn;\r
1608 }\r
1609 /*-----------------------------------------------------------*/\r
1610 \r
1611 void vTaskMissedYield( void )\r
1612 {\r
1613         xMissedYield = pdTRUE;\r
1614 }\r
1615 \r
1616 /*\r
1617  * -----------------------------------------------------------\r
1618  * The Idle task.\r
1619  * ----------------------------------------------------------\r
1620  *\r
1621  * The portTASK_FUNCTION() macro is used to allow port/compiler specific\r
1622  * language extensions.  The equivalent prototype for this function is:\r
1623  *\r
1624  * void prvIdleTask( void *pvParameters );\r
1625  *\r
1626  */\r
1627 static portTASK_FUNCTION( prvIdleTask, pvParameters )\r
1628 {\r
1629         /* Stop warnings. */\r
1630         ( void ) pvParameters;\r
1631 \r
1632         for( ;; )\r
1633         {\r
1634                 /* See if any tasks have been deleted. */\r
1635                 prvCheckTasksWaitingTermination();\r
1636 \r
1637                 #if ( configUSE_PREEMPTION == 0 )\r
1638                 {\r
1639                         /* If we are not using preemption we keep forcing a task switch to\r
1640                         see if any other task has become available.  If we are using\r
1641                         preemption we don't need to do this as any task becoming available\r
1642                         will automatically get the processor anyway. */\r
1643                         taskYIELD();    \r
1644                 }\r
1645                 #endif\r
1646 \r
1647                 #if ( ( configUSE_PREEMPTION == 1 ) && ( configIDLE_SHOULD_YIELD == 1 ) )\r
1648                 {\r
1649                         /* When using preemption tasks of equal priority will be\r
1650                         timesliced.  If a task that is sharing the idle priority is ready\r
1651                         to run then the idle task should yield before the end of the\r
1652                         timeslice.\r
1653                         \r
1654                         A critical region is not required here as we are just reading from\r
1655                         the list, and an occasional incorrect value will not matter.  If\r
1656                         the ready list at the idle priority contains more than one task\r
1657                         then a task other than the idle task is ready to execute. */\r
1658                         if( listCURRENT_LIST_LENGTH( &( pxReadyTasksLists[ tskIDLE_PRIORITY ] ) ) > ( unsigned portBASE_TYPE ) 1 )\r
1659                         {\r
1660                                 taskYIELD();\r
1661                         }\r
1662                 }\r
1663                 #endif\r
1664 \r
1665                 #if ( configUSE_IDLE_HOOK == 1 )\r
1666                 {\r
1667                         extern void vApplicationIdleHook( void );\r
1668 \r
1669                         /* Call the user defined function from within the idle task.  This\r
1670                         allows the application designer to add background functionality\r
1671                         without the overhead of a separate task.\r
1672                         NOTE: vApplicationIdleHook() MUST NOT, UNDER ANY CIRCUMSTANCES,\r
1673                         CALL A FUNCTION THAT MIGHT BLOCK. */\r
1674                         vApplicationIdleHook();\r
1675                 }\r
1676                 #endif\r
1677         }\r
1678 } /*lint !e715 pvParameters is not accessed but all task functions require the same prototype. */\r
1679 \r
1680 \r
1681 \r
1682 \r
1683 \r
1684 \r
1685 \r
1686 /*-----------------------------------------------------------\r
1687  * File private functions documented at the top of the file.\r
1688  *----------------------------------------------------------*/\r
1689 \r
1690 \r
1691 \r
1692 static void prvInitialiseTCBVariables( tskTCB *pxTCB, const signed portCHAR * const pcName, unsigned portBASE_TYPE uxPriority )\r
1693 {\r
1694         /* Store the function name in the TCB. */\r
1695         strncpy( ( char * ) pxTCB->pcTaskName, ( const char * ) pcName, ( unsigned portSHORT ) configMAX_TASK_NAME_LEN );\r
1696         pxTCB->pcTaskName[ ( unsigned portSHORT ) configMAX_TASK_NAME_LEN - ( unsigned portSHORT ) 1 ] = '\0';\r
1697 \r
1698         #if ( portCRITICAL_NESTING_IN_TCB == 1 )\r
1699         {\r
1700                 pxTCB->uxCriticalNesting = ( unsigned portBASE_TYPE ) 0;\r
1701         }\r
1702         #endif\r
1703 \r
1704         /* This is used as an array index so must ensure it's not too large. */\r
1705         if( uxPriority >= configMAX_PRIORITIES )\r
1706         {\r
1707                 uxPriority = configMAX_PRIORITIES - 1;\r
1708         }\r
1709 \r
1710         pxTCB->uxPriority = uxPriority;\r
1711         #if ( configUSE_MUTEXES == 1 )\r
1712         {\r
1713                 pxTCB->uxBasePriority = uxPriority;\r
1714         }\r
1715         #endif\r
1716 \r
1717         vListInitialiseItem( &( pxTCB->xGenericListItem ) );\r
1718         vListInitialiseItem( &( pxTCB->xEventListItem ) );\r
1719 \r
1720         /* Set the pxTCB as a link back from the xListItem.  This is so we can get\r
1721         back to the containing TCB from a generic item in a list. */\r
1722         listSET_LIST_ITEM_OWNER( &( pxTCB->xGenericListItem ), pxTCB );\r
1723 \r
1724         /* Event lists are always in priority order. */\r
1725         listSET_LIST_ITEM_VALUE( &( pxTCB->xEventListItem ), configMAX_PRIORITIES - ( portTickType ) uxPriority );\r
1726         listSET_LIST_ITEM_OWNER( &( pxTCB->xEventListItem ), pxTCB );\r
1727 }\r
1728 /*-----------------------------------------------------------*/\r
1729 \r
1730 static void prvInitialiseTaskLists( void )\r
1731 {\r
1732 unsigned portBASE_TYPE uxPriority;\r
1733 \r
1734         for( uxPriority = 0; uxPriority < configMAX_PRIORITIES; uxPriority++ )\r
1735         {\r
1736                 vListInitialise( ( xList * ) &( pxReadyTasksLists[ uxPriority ] ) );\r
1737         }\r
1738 \r
1739         vListInitialise( ( xList * ) &xDelayedTaskList1 );\r
1740         vListInitialise( ( xList * ) &xDelayedTaskList2 );\r
1741         vListInitialise( ( xList * ) &xPendingReadyList );\r
1742 \r
1743         #if ( INCLUDE_vTaskDelete == 1 )\r
1744         {\r
1745                 vListInitialise( ( xList * ) &xTasksWaitingTermination );\r
1746         }\r
1747         #endif\r
1748 \r
1749         #if ( INCLUDE_vTaskSuspend == 1 )\r
1750         {\r
1751                 vListInitialise( ( xList * ) &xSuspendedTaskList );\r
1752         }\r
1753         #endif\r
1754 \r
1755         /* Start with pxDelayedTaskList using list1 and the pxOverflowDelayedTaskList\r
1756         using list2. */\r
1757         pxDelayedTaskList = &xDelayedTaskList1;\r
1758         pxOverflowDelayedTaskList = &xDelayedTaskList2;\r
1759 }\r
1760 /*-----------------------------------------------------------*/\r
1761 \r
1762 static void prvCheckTasksWaitingTermination( void )\r
1763 {                                                       \r
1764         #if ( INCLUDE_vTaskDelete == 1 )\r
1765         {                               \r
1766                 portBASE_TYPE xListIsEmpty;\r
1767 \r
1768                 /* ucTasksDeleted is used to prevent vTaskSuspendAll() being called\r
1769                 too often in the idle task. */\r
1770                 if( uxTasksDeleted > ( unsigned portBASE_TYPE ) 0 )\r
1771                 {\r
1772                         vTaskSuspendAll();\r
1773                                 xListIsEmpty = listLIST_IS_EMPTY( &xTasksWaitingTermination );                          \r
1774                         xTaskResumeAll();\r
1775 \r
1776                         if( !xListIsEmpty )\r
1777                         {\r
1778                                 tskTCB *pxTCB;\r
1779 \r
1780                                 portENTER_CRITICAL();\r
1781                                 {                       \r
1782                                         pxTCB = ( tskTCB * ) listGET_OWNER_OF_HEAD_ENTRY( ( ( xList * ) &xTasksWaitingTermination ) );\r
1783                                         vListRemove( &( pxTCB->xGenericListItem ) );\r
1784                                         --uxCurrentNumberOfTasks;\r
1785                                         --uxTasksDeleted;\r
1786                                 }\r
1787                                 portEXIT_CRITICAL();\r
1788 \r
1789                                 prvDeleteTCB( pxTCB );\r
1790                         }\r
1791                 }\r
1792         }\r
1793         #endif\r
1794 }\r
1795 /*-----------------------------------------------------------*/\r
1796 \r
1797 static tskTCB *prvAllocateTCBAndStack( unsigned portSHORT usStackDepth )\r
1798 {\r
1799 tskTCB *pxNewTCB;\r
1800 \r
1801         /* Allocate space for the TCB.  Where the memory comes from depends on\r
1802         the implementation of the port malloc function. */\r
1803         pxNewTCB = ( tskTCB * ) pvPortMalloc( sizeof( tskTCB ) );\r
1804 \r
1805         if( pxNewTCB != NULL )\r
1806         {\r
1807                 /* Allocate space for the stack used by the task being created.\r
1808                 The base of the stack memory stored in the TCB so the task can\r
1809                 be deleted later if required. */\r
1810                 pxNewTCB->pxStack = ( portSTACK_TYPE * ) pvPortMalloc( ( ( size_t )usStackDepth ) * sizeof( portSTACK_TYPE ) );\r
1811 \r
1812                 if( pxNewTCB->pxStack == NULL )\r
1813                 {\r
1814                         /* Could not allocate the stack.  Delete the allocated TCB. */\r
1815                         vPortFree( pxNewTCB );                  \r
1816                         pxNewTCB = NULL;                        \r
1817                 }               \r
1818                 else\r
1819                 {\r
1820                         /* Just to help debugging. */\r
1821                         memset( pxNewTCB->pxStack, tskSTACK_FILL_BYTE, usStackDepth * sizeof( portSTACK_TYPE ) );\r
1822                 }\r
1823         }\r
1824 \r
1825         return pxNewTCB;\r
1826 }\r
1827 /*-----------------------------------------------------------*/\r
1828 \r
1829 #if ( configUSE_TRACE_FACILITY == 1 )\r
1830 \r
1831         static void prvListTaskWithinSingleList( const signed portCHAR *pcWriteBuffer, xList *pxList, signed portCHAR cStatus )\r
1832         {\r
1833         volatile tskTCB *pxNextTCB, *pxFirstTCB;\r
1834         static portCHAR pcStatusString[ 50 ];\r
1835         unsigned portSHORT usStackRemaining;\r
1836 \r
1837                 /* Write the details of all the TCB's in pxList into the buffer. */\r
1838                 listGET_OWNER_OF_NEXT_ENTRY( pxFirstTCB, pxList );\r
1839                 do\r
1840                 {\r
1841                         listGET_OWNER_OF_NEXT_ENTRY( pxNextTCB, pxList );\r
1842                         usStackRemaining = usTaskCheckFreeStackSpace( ( unsigned portCHAR * ) pxNextTCB->pxStack );\r
1843                         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
1844                         strcat( ( portCHAR * ) pcWriteBuffer, ( portCHAR * ) pcStatusString );\r
1845 \r
1846                 } while( pxNextTCB != pxFirstTCB );\r
1847         }\r
1848 \r
1849 #endif\r
1850 /*-----------------------------------------------------------*/\r
1851 \r
1852 #if ( ( configUSE_TRACE_FACILITY == 1 ) || ( INCLUDE_uxTaskGetStackHighWaterMark == 1 ) )\r
1853 \r
1854         unsigned portSHORT usTaskCheckFreeStackSpace( const unsigned portCHAR * pucStackByte )\r
1855         {\r
1856         register unsigned portSHORT usCount = 0;\r
1857 \r
1858                 while( *pucStackByte == tskSTACK_FILL_BYTE )\r
1859                 {\r
1860                         pucStackByte -= portSTACK_GROWTH;\r
1861                         usCount++;\r
1862                 }\r
1863 \r
1864                 usCount /= sizeof( portSTACK_TYPE );\r
1865 \r
1866                 return usCount;\r
1867         }\r
1868 \r
1869 #endif\r
1870 /*-----------------------------------------------------------*/\r
1871 \r
1872 #if ( INCLUDE_uxTaskGetStackHighWaterMark == 1 )\r
1873 \r
1874         unsigned portBASE_TYPE uxTaskGetStackHighWaterMark( xTaskHandle xTask )\r
1875         {\r
1876         tskTCB *pxTCB;\r
1877 \r
1878                 pxTCB = prvGetTCBFromHandle( xTask );\r
1879                 return usTaskCheckFreeStackSpace( ( unsigned portCHAR * ) pxTCB->pxStack );\r
1880         }\r
1881 \r
1882 #endif\r
1883 /*-----------------------------------------------------------*/\r
1884 \r
1885 #if ( ( INCLUDE_vTaskDelete == 1 ) || ( INCLUDE_vTaskCleanUpResources == 1 ) )\r
1886 \r
1887         static void prvDeleteTCB( tskTCB *pxTCB )\r
1888         {\r
1889                 /* Free up the memory allocated by the scheduler for the task.  It is up to\r
1890                 the task to free any memory allocated at the application level. */\r
1891                 vPortFree( pxTCB->pxStack );\r
1892                 vPortFree( pxTCB );\r
1893         }\r
1894 \r
1895 #endif\r
1896 \r
1897 \r
1898 /*-----------------------------------------------------------*/\r
1899 \r
1900 #if ( INCLUDE_xTaskGetCurrentTaskHandle == 1 )\r
1901 \r
1902         xTaskHandle xTaskGetCurrentTaskHandle( void )\r
1903         {\r
1904         xTaskHandle xReturn;\r
1905 \r
1906                 portENTER_CRITICAL();\r
1907                 {\r
1908                         xReturn = ( xTaskHandle ) pxCurrentTCB;\r
1909                 }\r
1910                 portEXIT_CRITICAL();\r
1911 \r
1912                 return xReturn;\r
1913         }\r
1914 \r
1915 #endif\r
1916 \r
1917 /*-----------------------------------------------------------*/\r
1918 \r
1919 #if ( INCLUDE_xTaskGetSchedulerState == 1 )\r
1920 \r
1921         portBASE_TYPE xTaskGetSchedulerState( void )\r
1922         {\r
1923         portBASE_TYPE xReturn;\r
1924         \r
1925                 if( xSchedulerRunning == pdFALSE )\r
1926                 {\r
1927                         xReturn = taskSCHEDULER_NOT_STARTED;\r
1928                 }\r
1929                 else\r
1930                 {\r
1931                         if( uxSchedulerSuspended == ( unsigned portBASE_TYPE ) pdFALSE )\r
1932                         {\r
1933                                 xReturn = taskSCHEDULER_RUNNING;\r
1934                         }\r
1935                         else\r
1936                         {\r
1937                                 xReturn = taskSCHEDULER_SUSPENDED;\r
1938                         }\r
1939                 }\r
1940                 \r
1941                 return xReturn;\r
1942         }\r
1943 \r
1944 #endif\r
1945 /*-----------------------------------------------------------*/\r
1946 \r
1947 #if ( configUSE_MUTEXES == 1 )\r
1948         \r
1949         void vTaskPriorityInherit( xTaskHandle * const pxMutexHolder )\r
1950         {\r
1951         tskTCB * const pxTCB = ( tskTCB * ) pxMutexHolder;\r
1952 \r
1953                 if( pxTCB->uxPriority < pxCurrentTCB->uxPriority )\r
1954                 {\r
1955                         /* Adjust the mutex holder state to account for its new priority. */\r
1956                         listSET_LIST_ITEM_VALUE( &( pxTCB->xEventListItem ), configMAX_PRIORITIES - ( portTickType ) pxCurrentTCB->uxPriority );\r
1957 \r
1958                         /* If the task being modified is in the ready state it will need to\r
1959                         be moved in to a new list. */\r
1960                         if( listIS_CONTAINED_WITHIN( &( pxReadyTasksLists[ pxTCB->uxPriority ] ), &( pxTCB->xGenericListItem ) ) )\r
1961                         {\r
1962                                 vListRemove( &( pxTCB->xGenericListItem ) );\r
1963 \r
1964                                 /* Inherit the priority before being moved into the new list. */\r
1965                                 pxTCB->uxPriority = pxCurrentTCB->uxPriority;\r
1966                                 prvAddTaskToReadyQueue( pxTCB );\r
1967                         }\r
1968                         else\r
1969                         {\r
1970                                 /* Just inherit the priority. */\r
1971                                 pxTCB->uxPriority = pxCurrentTCB->uxPriority;\r
1972                         }\r
1973                 }\r
1974         }\r
1975 \r
1976 #endif\r
1977 /*-----------------------------------------------------------*/\r
1978 \r
1979 #if ( configUSE_MUTEXES == 1 )  \r
1980 \r
1981         void vTaskPriorityDisinherit( xTaskHandle * const pxMutexHolder )\r
1982         {\r
1983         tskTCB * const pxTCB = ( tskTCB * ) pxMutexHolder;\r
1984 \r
1985                 if( pxMutexHolder != NULL )\r
1986                 {\r
1987                         if( pxTCB->uxPriority != pxTCB->uxBasePriority )\r
1988                         {\r
1989                                 /* We must be the running task to be able to give the mutex back.\r
1990                                 Remove ourselves from the ready list we currently appear in. */\r
1991                                 vListRemove( &( pxTCB->xGenericListItem ) );\r
1992 \r
1993                                 /* Disinherit the priority before adding ourselves into the new\r
1994                                 ready list. */\r
1995                                 pxTCB->uxPriority = pxTCB->uxBasePriority;\r
1996                                 listSET_LIST_ITEM_VALUE( &( pxTCB->xEventListItem ), configMAX_PRIORITIES - ( portTickType ) pxTCB->uxPriority );\r
1997                                 prvAddTaskToReadyQueue( pxTCB );\r
1998                         }\r
1999                 }\r
2000         }\r
2001 \r
2002 #endif\r
2003 /*-----------------------------------------------------------*/\r
2004 \r
2005 #if ( portCRITICAL_NESTING_IN_TCB == 1 )\r
2006 \r
2007         void vTaskEnterCritical( void )\r
2008         {\r
2009                 portDISABLE_INTERRUPTS();\r
2010 \r
2011                 if( xSchedulerRunning != pdFALSE )\r
2012                 {\r
2013                         pxCurrentTCB->uxCriticalNesting++;\r
2014                 }\r
2015         }\r
2016 \r
2017 #endif\r
2018 /*-----------------------------------------------------------*/\r
2019 \r
2020 #if ( portCRITICAL_NESTING_IN_TCB == 1 )\r
2021 \r
2022 void vTaskExitCritical( void )\r
2023 {\r
2024         if( xSchedulerRunning != pdFALSE )\r
2025         {\r
2026                 if( pxCurrentTCB->uxCriticalNesting > 0 )\r
2027                 {\r
2028                         pxCurrentTCB->uxCriticalNesting--;\r
2029 \r
2030                         if( pxCurrentTCB->uxCriticalNesting == 0 )\r
2031                         {\r
2032                                 portENABLE_INTERRUPTS();\r
2033                         }\r
2034                 }\r
2035         }\r
2036 }\r
2037 \r
2038 #endif\r
2039 /*-----------------------------------------------------------*/\r
2040 \r
2041 \r
2042         \r
2043 \r