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   1 /*\r
   2         FreeRTOS.org V4.7.2 - Copyright (C) 2003-2008 Richard Barry.\r
   3 \r
   4         This file is part of the FreeRTOS.org distribution.\r
   5 \r
   6         FreeRTOS.org is free software; you can redistribute it and/or modify\r
   7         it under the terms of the GNU General Public License as published by\r
   8         the Free Software Foundation; either version 2 of the License, or\r
   9         (at your option) any later version.\r
  10 \r
  11         FreeRTOS.org is distributed in the hope that it will be useful,\r
  12         but WITHOUT ANY WARRANTY; without even the implied warranty of\r
  13         MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the\r
  14         GNU General Public License for more details.\r
  15 \r
  16         You should have received a copy of the GNU General Public License\r
  17         along with FreeRTOS.org; if not, write to the Free Software\r
  18         Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA\r
  19 \r
  20         A special exception to the GPL can be applied should you wish to distribute\r
  21         a combined work that includes FreeRTOS.org, without being obliged to provide\r
  22         the source code for any proprietary components.  See the licensing section\r
  23         of http://www.FreeRTOS.org for full details of how and when the exception\r
  24         can be applied.\r
  25 \r
  26         ***************************************************************************\r
  27 \r
  28         Please ensure to read the configuration and relevant port sections of the\r
  29         online documentation.\r
  30 \r
  31         +++ http://www.FreeRTOS.org +++\r
  32         Documentation, latest information, license and contact details.\r
  33 \r
  34         +++ http://www.SafeRTOS.com +++\r
  35         A version that is certified for use in safety critical systems.\r
  36 \r
  37         +++ http://www.OpenRTOS.com +++\r
  38         Commercial support, development, porting, licensing and training services.\r
  39 \r
  40         ***************************************************************************\r
  41 */\r
  42 \r
  43 \r
  44 #include <stdio.h>\r
  45 #include <stdlib.h>\r
  46 #include <string.h>\r
  47 \r
  48 #include "FreeRTOS.h"\r
  49 #include "task.h"\r
  50 \r
  51 /*\r
  52  * Macro to define the amount of stack available to the idle task.\r
  53  */\r
  54 #define tskIDLE_STACK_SIZE      configMINIMAL_STACK_SIZE\r
  55 \r
  56 \r
  57 /*\r
  58  * Default a definitions for backwards compatibility with old\r
  59  * portmacro.h files.\r
  60  */\r
  61 #ifndef configMAX_TASK_NAME_LEN\r
  62         #define configMAX_TASK_NAME_LEN 16\r
  63 #endif\r
  64 \r
  65 #ifndef configIDLE_SHOULD_YIELD\r
  66         #define configIDLE_SHOULD_YIELD         1\r
  67 #endif\r
  68 \r
  69 #if configMAX_TASK_NAME_LEN < 1\r
  70         #undef configMAX_TASK_NAME_LEN\r
  71         #define configMAX_TASK_NAME_LEN 1\r
  72 #endif\r
  73 \r
  74 #ifndef INCLUDE_xTaskResumeFromISR\r
  75         #define INCLUDE_xTaskResumeFromISR 1\r
  76 #endif\r
  77 \r
  78 #ifndef INCLUDE_xTaskGetSchedulerState\r
  79         #define INCLUDE_xTaskGetSchedulerState 0\r
  80 #endif\r
  81 \r
  82 /*\r
  83  * Task control block.  A task control block (TCB) is allocated to each task,\r
  84  * and stores the context of the task.\r
  85  */\r
  86 typedef struct tskTaskControlBlock\r
  87 {\r
  88         volatile portSTACK_TYPE *pxTopOfStack;          /*< Points to the location of the last item placed on the tasks stack.  THIS MUST BE THE FIRST MEMBER OF THE STRUCT. */\r
  89         xListItem                               xGenericListItem;       /*< List item used to place the TCB in ready and blocked queues. */\r
  90         xListItem                               xEventListItem;         /*< List item used to place the TCB in event lists. */\r
  91         unsigned portBASE_TYPE  uxPriority;                     /*< The priority of the task where 0 is the lowest priority. */\r
  92         portSTACK_TYPE                  *pxStack;                       /*< Points to the start of the stack. */\r
  93         signed portCHAR                 pcTaskName[ configMAX_TASK_NAME_LEN ];/*< Descriptive name given to the task when created.  Facilitates debugging only. */\r
  94 \r
  95         #if ( portCRITICAL_NESTING_IN_TCB == 1 )\r
  96                 unsigned portBASE_TYPE uxCriticalNesting;\r
  97         #endif\r
  98 \r
  99         #if ( configUSE_TRACE_FACILITY == 1 )\r
 100                 unsigned portBASE_TYPE  uxTCBNumber;            /*< This is used for tracing the scheduler and making debugging easier only. */\r
 101         #endif  \r
 102                 \r
 103         #if ( configUSE_MUTEXES == 1 )\r
 104                 unsigned portBASE_TYPE uxBasePriority;\r
 105         #endif\r
 106                 \r
 107 } tskTCB;\r
 108 \r
 109 /*lint -e956 */\r
 110 \r
 111 tskTCB * volatile pxCurrentTCB = NULL;                                  \r
 112 \r
 113 /* Lists for ready and blocked tasks. --------------------*/\r
 114 \r
 115 static xList pxReadyTasksLists[ configMAX_PRIORITIES ]; /*< Prioritised ready tasks. */\r
 116 static xList xDelayedTaskList1;                                                 /*< Delayed tasks. */\r
 117 static xList xDelayedTaskList2;                                                 /*< Delayed tasks (two lists are used - one for delays that have overflowed the current tick count. */\r
 118 static xList * volatile pxDelayedTaskList;                              /*< Points to the delayed task list currently being used. */\r
 119 static xList * volatile pxOverflowDelayedTaskList;              /*< Points to the delayed task list currently being used to hold tasks that have overflowed the current tick count. */\r
 120 static xList xPendingReadyList;                                                 /*< Tasks that have been readied while the scheduler was suspended.  They will be moved to the ready queue when the scheduler is resumed. */\r
 121 \r
 122 #if ( INCLUDE_vTaskDelete == 1 )\r
 123 \r
 124         static volatile xList xTasksWaitingTermination;         /*< Tasks that have been deleted - but the their memory not yet freed. */\r
 125         static volatile unsigned portBASE_TYPE uxTasksDeleted = ( unsigned portBASE_TYPE ) 0;\r
 126 \r
 127 #endif\r
 128 \r
 129 #if ( INCLUDE_vTaskSuspend == 1 )\r
 130 \r
 131         static xList xSuspendedTaskList;                                        /*< Tasks that are currently suspended. */\r
 132 \r
 133 #endif\r
 134 \r
 135 /* File private variables. --------------------------------*/\r
 136 static volatile unsigned portBASE_TYPE uxCurrentNumberOfTasks   = ( unsigned portBASE_TYPE ) 0;\r
 137 static volatile portTickType xTickCount                                                 = ( portTickType ) 0;\r
 138 static unsigned portBASE_TYPE uxTopUsedPriority                                 = tskIDLE_PRIORITY;\r
 139 static volatile unsigned portBASE_TYPE uxTopReadyPriority               = tskIDLE_PRIORITY;\r
 140 static volatile signed portBASE_TYPE xSchedulerRunning                  = pdFALSE;\r
 141 static volatile unsigned portBASE_TYPE uxSchedulerSuspended             = ( unsigned portBASE_TYPE ) pdFALSE;\r
 142 static volatile unsigned portBASE_TYPE uxMissedTicks                    = ( unsigned portBASE_TYPE ) 0;\r
 143 static volatile portBASE_TYPE xMissedYield                                              = ( portBASE_TYPE ) pdFALSE;\r
 144 static volatile portBASE_TYPE xNumOfOverflows                                   = ( portBASE_TYPE ) 0;\r
 145 /* Debugging and trace facilities private variables and macros. ------------*/\r
 146 \r
 147 /*\r
 148  * The value used to fill the stack of a task when the task is created.  This\r
 149  * is used purely for checking the high water mark for tasks.\r
 150  */\r
 151 #define tskSTACK_FILL_BYTE      ( 0xa5 )\r
 152 \r
 153 /*\r
 154  * Macros used by vListTask to indicate which state a task is in.\r
 155  */\r
 156 #define tskBLOCKED_CHAR         ( ( signed portCHAR ) 'B' )\r
 157 #define tskREADY_CHAR           ( ( signed portCHAR ) 'R' )\r
 158 #define tskDELETED_CHAR         ( ( signed portCHAR ) 'D' )\r
 159 #define tskSUSPENDED_CHAR       ( ( signed portCHAR ) 'S' )\r
 160 \r
 161 /*\r
 162  * Macros and private variables used by the trace facility.\r
 163  */\r
 164 #if ( configUSE_TRACE_FACILITY == 1 )\r
 165 \r
 166         #define tskSIZE_OF_EACH_TRACE_LINE                      ( ( unsigned portLONG ) ( sizeof( unsigned portLONG ) + sizeof( unsigned portLONG ) ) )\r
 167         static volatile signed portCHAR * volatile pcTraceBuffer;\r
 168         static signed portCHAR *pcTraceBufferStart;\r
 169         static signed portCHAR *pcTraceBufferEnd;\r
 170         static signed portBASE_TYPE xTracing = pdFALSE;\r
 171 \r
 172 #endif\r
 173 \r
 174 /*-----------------------------------------------------------*/\r
 175 \r
 176 /*\r
 177  * Macro that writes a trace of scheduler activity to a buffer.  This trace\r
 178  * shows which task is running when and is very useful as a debugging tool.\r
 179  * As this macro is called each context switch it is a good idea to undefine\r
 180  * it if not using the facility.\r
 181  */\r
 182 #if ( configUSE_TRACE_FACILITY == 1 )\r
 183 \r
 184         #define vWriteTraceToBuffer()                                                                                                                                   \\r
 185         {                                                                                                                                                                                               \\r
 186                 if( xTracing )                                                                                                                                                          \\r
 187                 {                                                                                                                                                                                       \\r
 188                         static unsigned portBASE_TYPE uxPreviousTask = 255;                                                                             \\r
 189                                                                                                                                                                                                         \\r
 190                         if( uxPreviousTask != pxCurrentTCB->uxTCBNumber )                                                                               \\r
 191                         {                                                                                                                                                                               \\r
 192                                 if( ( pcTraceBuffer + tskSIZE_OF_EACH_TRACE_LINE ) < pcTraceBufferEnd )                         \\r
 193                                 {                                                                                                                                                                       \\r
 194                                         uxPreviousTask = pxCurrentTCB->uxTCBNumber;                                                                             \\r
 195                                         *( unsigned portLONG * ) pcTraceBuffer = ( unsigned portLONG ) xTickCount;              \\r
 196                                         pcTraceBuffer += sizeof( unsigned portLONG );                                                                   \\r
 197                                         *( unsigned portLONG * ) pcTraceBuffer = ( unsigned portLONG ) uxPreviousTask;  \\r
 198                                         pcTraceBuffer += sizeof( unsigned portLONG );                                                                   \\r
 199                                 }                                                                                                                                                                       \\r
 200                                 else                                                                                                                                                            \\r
 201                                 {                                                                                                                                                                       \\r
 202                                         xTracing = pdFALSE;                                                                                                                             \\r
 203                                 }                                                                                                                                                                       \\r
 204                         }                                                                                                                                                                               \\r
 205                 }                                                                                                                                                                                       \\r
 206         }\r
 207 \r
 208 #else\r
 209 \r
 210         #define vWriteTraceToBuffer()\r
 211 \r
 212 #endif\r
 213 /*-----------------------------------------------------------*/\r
 214 \r
 215 /*\r
 216  * Place the task represented by pxTCB into the appropriate ready queue for\r
 217  * the task.  It is inserted at the end of the list.  One quirk of this is\r
 218  * that if the task being inserted is at the same priority as the currently\r
 219  * executing task, then it will only be rescheduled after the currently\r
 220  * executing task has been rescheduled.\r
 221  */\r
 222 #define prvAddTaskToReadyQueue( pxTCB )                                                                                                                                                 \\r
 223 {                                                                                                                                                                                                                               \\r
 224         if( pxTCB->uxPriority > uxTopReadyPriority )                                                                                                                            \\r
 225         {                                                                                                                                                                                                                       \\r
 226                 uxTopReadyPriority = pxTCB->uxPriority;                                                                                                                                 \\r
 227         }                                                                                                                                                                                                                       \\r
 228         vListInsertEnd( ( xList * ) &( pxReadyTasksLists[ pxTCB->uxPriority ] ), &( pxTCB->xGenericListItem ) );        \\r
 229 }\r
 230 /*-----------------------------------------------------------*/         \r
 231 \r
 232 /*\r
 233  * Macro that looks at the list of tasks that are currently delayed to see if\r
 234  * any require waking.\r
 235  *\r
 236  * Tasks are stored in the queue in the order of their wake time - meaning\r
 237  * once one tasks has been found whose timer has not expired we need not look\r
 238  * any further down the list.\r
 239  */\r
 240 #define prvCheckDelayedTasks()                                                                                                                                                                          \\r
 241 {                                                                                                                                                                                                                                       \\r
 242 register tskTCB *pxTCB;                                                                                                                                                                                         \\r
 243                                                                                                                                                                                                                                         \\r
 244         while( ( pxTCB = ( tskTCB * ) listGET_OWNER_OF_HEAD_ENTRY( pxDelayedTaskList ) ) != NULL )                                              \\r
 245         {                                                                                                                                                                                                                               \\r
 246                 if( xTickCount < listGET_LIST_ITEM_VALUE( &( pxTCB->xGenericListItem ) ) )                                                                      \\r
 247                 {                                                                                                                                                                                                                       \\r
 248                         break;                                                                                                                                                                                                  \\r
 249                 }                                                                                                                                                                                                                       \\r
 250                 vListRemove( &( pxTCB->xGenericListItem ) );                                                                                                                            \\r
 251                 /* Is the task waiting on an event also? */                                                                                                                                     \\r
 252                 if( pxTCB->xEventListItem.pvContainer )                                                                                                                                         \\r
 253                 {                                                                                                                                                                                                                       \\r
 254                         vListRemove( &( pxTCB->xEventListItem ) );                                                                                                                              \\r
 255                 }                                                                                                                                                                                                                       \\r
 256                 prvAddTaskToReadyQueue( pxTCB );                                                                                                                                                        \\r
 257         }                                                                                                                                                                                                                               \\r
 258 }\r
 259 /*-----------------------------------------------------------*/\r
 260 \r
 261 /*\r
 262  * Call the stack overflow hook function if the stack of the task being swapped\r
 263  * out is currently overflowed, or looks like it might have overflowed in the\r
 264  * past.\r
 265  *\r
 266  * Setting configCHECK_FOR_STACK_OVERFLOW to 1 will cause the macro to check\r
 267  * the current stack state only - comparing the current top of stack value to\r
 268  * the stack limit.  Setting configCHECK_FOR_STACK_OVERFLOW to greater than 1\r
 269  * will also cause the last few stack bytes to be checked to ensure the value\r
 270  * to which the bytes were set when the task was created have not been \r
 271  * overwritten.  Note this second test does not guarantee that an overflown\r
 272  * stack will always be recognised.\r
 273  */\r
 274 \r
 275 #if( configCHECK_FOR_STACK_OVERFLOW == 0 )\r
 276 \r
 277         /* FreeRTOSConfig.h is not set to check for stack overflows. */\r
 278         #define taskCHECK_FOR_STACK_OVERFLOW()\r
 279 \r
 280 #endif /* configCHECK_FOR_STACK_OVERFLOW == 0 */\r
 281 \r
 282 #if( ( configCHECK_FOR_STACK_OVERFLOW > 0 ) && ( portSTACK_GROWTH >= 0 ) )\r
 283 \r
 284         /* This is an invalid setting. */\r
 285         #error configCHECK_FOR_STACK_OVERFLOW can only be set to a non zero value on architectures where the stack grows down from high memory.\r
 286 \r
 287 #endif /* ( configCHECK_FOR_STACK_OVERFLOW > 0 ) && ( portSTACK_GROWTH >= 0 ) */\r
 288 \r
 289 #if( configCHECK_FOR_STACK_OVERFLOW == 1 )\r
 290 \r
 291         /* Only the current stack state is to be checked. */\r
 292         #define taskCHECK_FOR_STACK_OVERFLOW()                                                                                                                          \\r
 293         {                                                                                                                                                                                                       \\r
 294         extern void vApplicationStackOverflowHook( xTaskHandle *pxTask, signed portCHAR *pcTaskName );          \\r
 295                                                                                                                                                                                                                 \\r
 296                 /* Is the currently saved stack pointer within the stack limit? */                                                              \\r
 297                 if( pxCurrentTCB->pxTopOfStack <= pxCurrentTCB->pxStack )                                                                               \\r
 298                 {                                                                                                                                                                                               \\r
 299                         vApplicationStackOverflowHook( pxCurrentTCB, pxCurrentTCB->pcTaskName );                                        \\r
 300                 }                                                                                                                                                                                               \\r
 301         }\r
 302 \r
 303 #endif /* configCHECK_FOR_STACK_OVERFLOW == 1 */\r
 304 \r
 305 #if( configCHECK_FOR_STACK_OVERFLOW > 1 )\r
 306 \r
 307         /* Both the current statck state and the stack fill bytes are to be checked. */\r
 308         #define taskCHECK_FOR_STACK_OVERFLOW()                                                                                                                                                                                                                  \\r
 309         {                                                                                                                                                                                                                                                                                               \\r
 310         extern void vApplicationStackOverflowHook( xTaskHandle *pxTask, signed portCHAR *pcTaskName );                                                                                                  \\r
 311         static const unsigned portCHAR ucExpectedStackBytes[] = {       tskSTACK_FILL_BYTE, tskSTACK_FILL_BYTE, tskSTACK_FILL_BYTE, tskSTACK_FILL_BYTE,         \\r
 312                                                                                                                                 tskSTACK_FILL_BYTE, tskSTACK_FILL_BYTE, tskSTACK_FILL_BYTE, tskSTACK_FILL_BYTE,         \\r
 313                                                                                                                                 tskSTACK_FILL_BYTE, tskSTACK_FILL_BYTE, tskSTACK_FILL_BYTE, tskSTACK_FILL_BYTE,         \\r
 314                                                                                                                                 tskSTACK_FILL_BYTE, tskSTACK_FILL_BYTE, tskSTACK_FILL_BYTE, tskSTACK_FILL_BYTE,         \\r
 315                                                                                                                                 tskSTACK_FILL_BYTE, tskSTACK_FILL_BYTE, tskSTACK_FILL_BYTE, tskSTACK_FILL_BYTE };       \\r
 316                                                                                                                                                                                                                                                                                                         \\r
 317                 /* Is the currently saved stack pointer within the stack limit? */                                                                                                                                                      \\r
 318                 if( pxCurrentTCB->pxTopOfStack <= pxCurrentTCB->pxStack )                                                                                                                                                                       \\r
 319                 {                                                                                                                                                                                                                                                                                       \\r
 320                         vApplicationStackOverflowHook( pxCurrentTCB, pxCurrentTCB->pcTaskName );                                                                                                                                \\r
 321                 }                                                                                                                                                                                                                                                                                       \\r
 322                                                                                                                                                                                                                                                                                                         \\r
 323                 /* Has the extremity of the task stack ever been written over? */                                                                                                                                                       \\r
 324                 if( memcmp( pxCurrentTCB->pxStack, ucExpectedStackBytes, sizeof( ucExpectedStackBytes ) ) != 0 )                                                                                        \\r
 325                 {                                                                                                                                                                                                                                                                                       \\r
 326                         vApplicationStackOverflowHook( pxCurrentTCB, pxCurrentTCB->pcTaskName );                                                                                                                                \\r
 327                 }                                                                                                                                                                                                                                                                                       \\r
 328         }\r
 329 \r
 330 #endif /* #if( configCHECK_FOR_STACK_OVERFLOW > 1 ) */\r
 331 /*-----------------------------------------------------------*/\r
 332 \r
 333 /*\r
 334  * Several functions take an xTaskHandle parameter that can optionally be NULL,\r
 335  * where NULL is used to indicate that the handle of the currently executing\r
 336  * task should be used in place of the parameter.  This macro simply checks to\r
 337  * see if the parameter is NULL and returns a pointer to the appropriate TCB.\r
 338  */\r
 339 #define prvGetTCBFromHandle( pxHandle ) ( ( pxHandle == NULL ) ? ( tskTCB * ) pxCurrentTCB : ( tskTCB * ) pxHandle )\r
 340 \r
 341 \r
 342 /* File private functions. --------------------------------*/\r
 343 \r
 344 /*\r
 345  * Utility to ready a TCB for a given task.  Mainly just copies the parameters\r
 346  * into the TCB structure.\r
 347  */\r
 348 static void prvInitialiseTCBVariables( tskTCB *pxTCB, const signed portCHAR * const pcName, unsigned portBASE_TYPE uxPriority );\r
 349 \r
 350 /*\r
 351  * Utility to ready all the lists used by the scheduler.  This is called\r
 352  * automatically upon the creation of the first task.\r
 353  */\r
 354 static void prvInitialiseTaskLists( void );\r
 355 \r
 356 /*\r
 357  * The idle task, which as all tasks is implemented as a never ending loop.\r
 358  * The idle task is automatically created and added to the ready lists upon\r
 359  * creation of the first user task.\r
 360  *\r
 361  * The portTASK_FUNCTION_PROTO() macro is used to allow port/compiler specific\r
 362  * language extensions.  The equivalent prototype for this function is:\r
 363  *\r
 364  * void prvIdleTask( void *pvParameters );\r
 365  *\r
 366  */\r
 367 static portTASK_FUNCTION_PROTO( prvIdleTask, pvParameters );\r
 368 \r
 369 /*\r
 370  * Utility to free all memory allocated by the scheduler to hold a TCB,\r
 371  * including the stack pointed to by the TCB.\r
 372  *\r
 373  * This does not free memory allocated by the task itself (i.e. memory\r
 374  * allocated by calls to pvPortMalloc from within the tasks application code).\r
 375  */\r
 376 #if ( ( INCLUDE_vTaskDelete == 1 ) || ( INCLUDE_vTaskCleanUpResources == 1 ) )\r
 377         static void prvDeleteTCB( tskTCB *pxTCB );\r
 378 #endif\r
 379 \r
 380 /*\r
 381  * Used only by the idle task.  This checks to see if anything has been placed\r
 382  * in the list of tasks waiting to be deleted.  If so the task is cleaned up\r
 383  * and its TCB deleted.\r
 384  */\r
 385 static void prvCheckTasksWaitingTermination( void );\r
 386 \r
 387 /*\r
 388  * Allocates memory from the heap for a TCB and associated stack.  Checks the\r
 389  * allocation was successful.\r
 390  */\r
 391 static tskTCB *prvAllocateTCBAndStack( unsigned portSHORT usStackDepth );\r
 392 \r
 393 /*\r
 394  * Called from vTaskList.  vListTasks details all the tasks currently under\r
 395  * control of the scheduler.  The tasks may be in one of a number of lists.\r
 396  * prvListTaskWithinSingleList accepts a list and details the tasks from\r
 397  * within just that list.\r
 398  *\r
 399  * THIS FUNCTION IS INTENDED FOR DEBUGGING ONLY, AND SHOULD NOT BE CALLED FROM\r
 400  * NORMAL APPLICATION CODE.\r
 401  */\r
 402 #if ( configUSE_TRACE_FACILITY == 1 )\r
 403 \r
 404         static void prvListTaskWithinSingleList( const signed portCHAR *pcWriteBuffer, xList *pxList, signed portCHAR cStatus );\r
 405 \r
 406 #endif\r
 407 \r
 408 /*\r
 409  * When a task is created, the stack of the task is filled with a known value.\r
 410  * This function determines the 'high water mark' of the task stack by\r
 411  * determining how much of the stack remains at the original preset value.\r
 412  */\r
 413 #if ( ( configUSE_TRACE_FACILITY == 1 ) || ( INCLUDE_uxTaskGetStackHighWaterMark == 1 ) )\r
 414 \r
 415         unsigned portSHORT usTaskCheckFreeStackSpace( const unsigned portCHAR * pucStackByte );\r
 416 \r
 417 #endif\r
 418 \r
 419 /*\r
 420  * Checks that a task being resumed (unsuspended) is actually in the Suspended\r
 421  * state.\r
 422  */\r
 423 #if ( INCLUDE_vTaskSuspend == 1 )\r
 424 \r
 425         static portBASE_TYPE prvIsTaskSuspended( const tskTCB * const pxTCB );  \r
 426 \r
 427 #endif\r
 428 \r
 429 /*lint +e956 */\r
 430 \r
 431 \r
 432 \r
 433 /*-----------------------------------------------------------\r
 434  * TASK CREATION API documented in task.h\r
 435  *----------------------------------------------------------*/\r
 436 \r
 437 signed portBASE_TYPE xTaskCreate( pdTASK_CODE pvTaskCode, const signed portCHAR * const pcName, unsigned portSHORT usStackDepth, void *pvParameters, unsigned portBASE_TYPE uxPriority, xTaskHandle *pxCreatedTask )\r
 438 {\r
 439 signed portBASE_TYPE xReturn;\r
 440 tskTCB * pxNewTCB;\r
 441 #if ( configUSE_TRACE_FACILITY == 1 )\r
 442         static unsigned portBASE_TYPE uxTaskNumber = 0; /*lint !e956 Static is deliberate - this is guarded before use. */\r
 443 #endif\r
 444 \r
 445         /* Allocate the memory required by the TCB and stack for the new task.\r
 446         checking that the allocation was successful. */\r
 447         pxNewTCB = prvAllocateTCBAndStack( usStackDepth );\r
 448 \r
 449         if( pxNewTCB != NULL )\r
 450         {               \r
 451                 portSTACK_TYPE *pxTopOfStack;\r
 452 \r
 453                 /* Setup the newly allocated TCB with the initial state of the task. */\r
 454                 prvInitialiseTCBVariables( pxNewTCB, pcName, uxPriority );\r
 455 \r
 456                 /* Calculate the top of stack address.  This depends on whether the\r
 457                 stack grows from high memory to low (as per the 80x86) or visa versa.\r
 458                 portSTACK_GROWTH is used to make the result positive or negative as\r
 459                 required by the port. */\r
 460                 #if portSTACK_GROWTH < 0\r
 461                 {\r
 462                         pxTopOfStack = pxNewTCB->pxStack + ( usStackDepth - 1 );\r
 463                 }\r
 464                 #else\r
 465                 {\r
 466                         pxTopOfStack = pxNewTCB->pxStack;       \r
 467                 }\r
 468                 #endif\r
 469 \r
 470                 /* Initialize the TCB stack to look as if the task was already running,\r
 471                 but had been interrupted by the scheduler.  The return address is set\r
 472                 to the start of the task function. Once the stack has been initialised\r
 473                 the     top of stack variable is updated. */\r
 474                 pxNewTCB->pxTopOfStack = pxPortInitialiseStack( pxTopOfStack, pvTaskCode, pvParameters );\r
 475 \r
 476                 /* We are going to manipulate the task queues to add this task to a\r
 477                 ready list, so must make sure no interrupts occur. */\r
 478                 portENTER_CRITICAL();\r
 479                 {\r
 480                         uxCurrentNumberOfTasks++;\r
 481                         if( uxCurrentNumberOfTasks == ( unsigned portBASE_TYPE ) 1 )\r
 482                         {\r
 483                                 /* As this is the first task it must also be the current task. */\r
 484                                 pxCurrentTCB =  pxNewTCB;\r
 485 \r
 486                                 /* This is the first task to be created so do the preliminary\r
 487                                 initialisation required.  We will not recover if this call\r
 488                                 fails, but we will report the failure. */\r
 489                                 prvInitialiseTaskLists();\r
 490                         }\r
 491                         else\r
 492                         {       \r
 493                                 /* If the scheduler is not already running, make this task the\r
 494                                 current task if it is the highest priority task to be created\r
 495                                 so far. */\r
 496                                 if( xSchedulerRunning == pdFALSE )\r
 497                                 {\r
 498                                         if( pxCurrentTCB->uxPriority <= uxPriority )\r
 499                                         {\r
 500                                                 pxCurrentTCB = pxNewTCB;        \r
 501                                         }\r
 502                                 }\r
 503                         }                               \r
 504 \r
 505                         /* Remember the top priority to make context switching faster.  Use\r
 506                         the priority in pxNewTCB as this has been capped to a valid value. */\r
 507                         if( pxNewTCB->uxPriority > uxTopUsedPriority )\r
 508                         {\r
 509                                 uxTopUsedPriority = pxNewTCB->uxPriority;\r
 510                         }\r
 511 \r
 512                         #if ( configUSE_TRACE_FACILITY == 1 )\r
 513                         {\r
 514                                 /* Add a counter into the TCB for tracing only. */\r
 515                                 pxNewTCB->uxTCBNumber = uxTaskNumber;\r
 516                                 uxTaskNumber++;\r
 517                         }\r
 518                         #endif\r
 519 \r
 520                         prvAddTaskToReadyQueue( pxNewTCB );\r
 521 \r
 522                         xReturn = pdPASS;\r
 523                         traceTASK_CREATE( pxNewTCB );\r
 524                 }\r
 525                 portEXIT_CRITICAL();\r
 526         }\r
 527         else\r
 528         {\r
 529                 xReturn = errCOULD_NOT_ALLOCATE_REQUIRED_MEMORY;\r
 530                 traceTASK_CREATE_FAILED( pxNewTCB );\r
 531         }\r
 532 \r
 533         if( xReturn == pdPASS )\r
 534         {\r
 535                 if( ( void * ) pxCreatedTask != NULL )\r
 536                 {\r
 537                         /* Pass the TCB out - in an anonymous way.  The calling function/\r
 538                         task can use this as a handle to delete the task later if\r
 539                         required.*/\r
 540                         *pxCreatedTask = ( xTaskHandle ) pxNewTCB;\r
 541                 }\r
 542 \r
 543                 if( xSchedulerRunning != pdFALSE )\r
 544                 {\r
 545                         /* If the created task is of a higher priority than the current task\r
 546                         then it should run now. */\r
 547                         if( pxCurrentTCB->uxPriority < uxPriority )\r
 548                         {\r
 549                                 taskYIELD();\r
 550                         }\r
 551                 }\r
 552         }\r
 553 \r
 554         return xReturn;\r
 555 }\r
 556 /*-----------------------------------------------------------*/\r
 557 \r
 558 #if ( INCLUDE_vTaskDelete == 1 )\r
 559 \r
 560         void vTaskDelete( xTaskHandle pxTaskToDelete )\r
 561         {\r
 562         tskTCB *pxTCB;\r
 563 \r
 564                 taskENTER_CRITICAL();\r
 565                 {\r
 566                         /* Ensure a yield is performed if the current task is being\r
 567                         deleted. */\r
 568                         if( pxTaskToDelete == pxCurrentTCB )\r
 569                         {\r
 570                                 pxTaskToDelete = NULL;\r
 571                         }\r
 572 \r
 573                         /* If null is passed in here then we are deleting ourselves. */\r
 574                         pxTCB = prvGetTCBFromHandle( pxTaskToDelete );\r
 575 \r
 576                         traceTASK_DELETE( pxTCB );\r
 577 \r
 578                         /* Remove task from the ready list and place in the     termination list.\r
 579                         This will stop the task from be scheduled.  The idle task will check\r
 580                         the termination list and free up any memory allocated by the\r
 581                         scheduler for the TCB and stack. */\r
 582                         vListRemove( &( pxTCB->xGenericListItem ) );\r
 583 \r
 584                         /* Is the task waiting on an event also? */                                                                                             \r
 585                         if( pxTCB->xEventListItem.pvContainer )\r
 586                         {\r
 587                                 vListRemove( &( pxTCB->xEventListItem ) );\r
 588                         }\r
 589 \r
 590                         vListInsertEnd( ( xList * ) &xTasksWaitingTermination, &( pxTCB->xGenericListItem ) );\r
 591 \r
 592                         /* Increment the ucTasksDeleted variable so the idle task knows\r
 593                         there is a task that has been deleted and that it should therefore\r
 594                         check the xTasksWaitingTermination list. */\r
 595                         ++uxTasksDeleted;\r
 596                 }\r
 597                 taskEXIT_CRITICAL();\r
 598 \r
 599                 /* Force a reschedule if we have just deleted the current task. */\r
 600                 if( xSchedulerRunning != pdFALSE )\r
 601                 {\r
 602                         if( ( void * ) pxTaskToDelete == NULL )\r
 603                         {\r
 604                                 taskYIELD();\r
 605                         }\r
 606                 }\r
 607         }\r
 608 \r
 609 #endif\r
 610 \r
 611 \r
 612 \r
 613 \r
 614 \r
 615 \r
 616 /*-----------------------------------------------------------\r
 617  * TASK CONTROL API documented in task.h\r
 618  *----------------------------------------------------------*/\r
 619 \r
 620 #if ( INCLUDE_vTaskDelayUntil == 1 )\r
 621 \r
 622         void vTaskDelayUntil( portTickType * const pxPreviousWakeTime, portTickType xTimeIncrement )\r
 623         {\r
 624         portTickType xTimeToWake;\r
 625         portBASE_TYPE xAlreadyYielded, xShouldDelay = pdFALSE;\r
 626 \r
 627                 vTaskSuspendAll();\r
 628                 {\r
 629                         /* Generate the tick time at which the task wants to wake. */\r
 630                         xTimeToWake = *pxPreviousWakeTime + xTimeIncrement;\r
 631 \r
 632                         if( xTickCount < *pxPreviousWakeTime )\r
 633                         {\r
 634                                 /* The tick count has overflowed since this function was\r
 635                                 lasted called.  In this case the only time we should ever\r
 636                                 actually delay is if the wake time has also     overflowed,\r
 637                                 and the wake time is greater than the tick time.  When this\r
 638                                 is the case it is as if neither time had overflowed. */\r
 639                                 if( ( xTimeToWake < *pxPreviousWakeTime ) && ( xTimeToWake > xTickCount ) )\r
 640                                 {\r
 641                                         xShouldDelay = pdTRUE;\r
 642                                 }\r
 643                         }\r
 644                         else\r
 645                         {\r
 646                                 /* The tick time has not overflowed.  In this case we will\r
 647                                 delay if either the wake time has overflowed, and/or the\r
 648                                 tick time is less than the wake time. */\r
 649                                 if( ( xTimeToWake < *pxPreviousWakeTime ) || ( xTimeToWake > xTickCount ) )\r
 650                                 {\r
 651                                         xShouldDelay = pdTRUE;\r
 652                                 }\r
 653                         }\r
 654 \r
 655                         /* Update the wake time ready for the next call. */\r
 656                         *pxPreviousWakeTime = xTimeToWake;\r
 657 \r
 658                         if( xShouldDelay )\r
 659                         {\r
 660                                 traceTASK_DELAY_UNTIL();\r
 661 \r
 662                                 /* We must remove ourselves from the ready list before adding\r
 663                                 ourselves to the blocked list as the same list item is used for\r
 664                                 both lists. */\r
 665                                 vListRemove( ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );\r
 666 \r
 667                                 /* The list item will be inserted in wake time order. */\r
 668                                 listSET_LIST_ITEM_VALUE( &( pxCurrentTCB->xGenericListItem ), xTimeToWake );\r
 669 \r
 670                                 if( xTimeToWake < xTickCount )\r
 671                                 {\r
 672                                         /* Wake time has overflowed.  Place this item in the\r
 673                                         overflow list. */\r
 674                                         vListInsert( ( xList * ) pxOverflowDelayedTaskList, ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );\r
 675                                 }\r
 676                                 else\r
 677                                 {\r
 678                                         /* The wake time has not overflowed, so we can use the\r
 679                                         current block list. */\r
 680                                         vListInsert( ( xList * ) pxDelayedTaskList, ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );\r
 681                                 }\r
 682                         }\r
 683                 }\r
 684                 xAlreadyYielded = xTaskResumeAll();\r
 685 \r
 686                 /* Force a reschedule if xTaskResumeAll has not already done so, we may\r
 687                 have put ourselves to sleep. */\r
 688                 if( !xAlreadyYielded )\r
 689                 {\r
 690                         taskYIELD();\r
 691                 }\r
 692         }       \r
 693         \r
 694 #endif\r
 695 /*-----------------------------------------------------------*/\r
 696 \r
 697 #if ( INCLUDE_vTaskDelay == 1 )\r
 698 \r
 699         void vTaskDelay( portTickType xTicksToDelay )\r
 700         {\r
 701         portTickType xTimeToWake;\r
 702         signed portBASE_TYPE xAlreadyYielded = pdFALSE;\r
 703 \r
 704                 /* A delay time of zero just forces a reschedule. */\r
 705                 if( xTicksToDelay > ( portTickType ) 0 )\r
 706                 {\r
 707                         vTaskSuspendAll();\r
 708                         {\r
 709                                 traceTASK_DELAY();\r
 710 \r
 711                                 /* A task that is removed from the event list while the\r
 712                                 scheduler is suspended will not get placed in the ready\r
 713                                 list or removed from the blocked list until the scheduler\r
 714                                 is resumed.\r
 715                                 \r
 716                                 This task cannot be in an event list as it is the currently\r
 717                                 executing task. */\r
 718 \r
 719                                 /* Calculate the time to wake - this may overflow but this is\r
 720                                 not a problem. */\r
 721                                 xTimeToWake = xTickCount + xTicksToDelay;\r
 722 \r
 723                                 /* We must remove ourselves from the ready list before adding\r
 724                                 ourselves to the blocked list as the same list item is used for\r
 725                                 both lists. */\r
 726                                 vListRemove( ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );\r
 727 \r
 728                                 /* The list item will be inserted in wake time order. */\r
 729                                 listSET_LIST_ITEM_VALUE( &( pxCurrentTCB->xGenericListItem ), xTimeToWake );\r
 730 \r
 731                                 if( xTimeToWake < xTickCount )\r
 732                                 {\r
 733                                         /* Wake time has overflowed.  Place this item in the\r
 734                                         overflow list. */\r
 735                                         vListInsert( ( xList * ) pxOverflowDelayedTaskList, ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );\r
 736                                 }\r
 737                                 else\r
 738                                 {\r
 739                                         /* The wake time has not overflowed, so we can use the\r
 740                                         current block list. */\r
 741                                         vListInsert( ( xList * ) pxDelayedTaskList, ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );\r
 742                                 }\r
 743                         }\r
 744                         xAlreadyYielded = xTaskResumeAll();\r
 745                 }\r
 746                 \r
 747                 /* Force a reschedule if xTaskResumeAll has not already done so, we may\r
 748                 have put ourselves to sleep. */\r
 749                 if( !xAlreadyYielded )\r
 750                 {\r
 751                         taskYIELD();\r
 752                 }\r
 753         }\r
 754         \r
 755 #endif\r
 756 /*-----------------------------------------------------------*/\r
 757 \r
 758 #if ( INCLUDE_uxTaskPriorityGet == 1 )\r
 759 \r
 760         unsigned portBASE_TYPE uxTaskPriorityGet( xTaskHandle pxTask )\r
 761         {\r
 762         tskTCB *pxTCB;\r
 763         unsigned portBASE_TYPE uxReturn;\r
 764 \r
 765                 taskENTER_CRITICAL();\r
 766                 {\r
 767                         /* If null is passed in here then we are changing the\r
 768                         priority of the calling function. */\r
 769                         pxTCB = prvGetTCBFromHandle( pxTask );\r
 770                         uxReturn = pxTCB->uxPriority;\r
 771                 }\r
 772                 taskEXIT_CRITICAL();\r
 773 \r
 774                 return uxReturn;\r
 775         }\r
 776 \r
 777 #endif\r
 778 /*-----------------------------------------------------------*/\r
 779 \r
 780 #if ( INCLUDE_vTaskPrioritySet == 1 )\r
 781 \r
 782         void vTaskPrioritySet( xTaskHandle pxTask, unsigned portBASE_TYPE uxNewPriority )\r
 783         {\r
 784         tskTCB *pxTCB;\r
 785         unsigned portBASE_TYPE uxCurrentPriority, xYieldRequired = pdFALSE;\r
 786 \r
 787                 /* Ensure the new priority is valid. */\r
 788                 if( uxNewPriority >= configMAX_PRIORITIES )\r
 789                 {\r
 790                         uxNewPriority = configMAX_PRIORITIES - 1;\r
 791                 }\r
 792 \r
 793                 taskENTER_CRITICAL();\r
 794                 {\r
 795                         /* If null is passed in here then we are changing the\r
 796                         priority of the calling function. */\r
 797                         pxTCB = prvGetTCBFromHandle( pxTask );\r
 798                         \r
 799                         traceTASK_PRIORITY_SET( pxTask, uxNewPriority );\r
 800 \r
 801                         #if ( configUSE_MUTEXES == 1 )\r
 802                         {\r
 803                                 uxCurrentPriority = pxTCB->uxBasePriority;\r
 804                         }\r
 805                         #else\r
 806                         {\r
 807                                 uxCurrentPriority = pxTCB->uxPriority;\r
 808                         }\r
 809                         #endif\r
 810 \r
 811                         if( uxCurrentPriority != uxNewPriority )\r
 812                         {\r
 813                                 /* The priority change may have readied a task of higher\r
 814                                 priority than the calling task. */\r
 815                                 if( uxNewPriority > uxCurrentPriority )\r
 816                                 {\r
 817                                         if( pxTask != NULL )\r
 818                                         {\r
 819                                                 /* The priority of another task is being raised.  If we\r
 820                                                 were raising the priority of the currently running task\r
 821                                                 there would be no need to switch as it must have already\r
 822                                                 been the highest priority task. */\r
 823                                                 xYieldRequired = pdTRUE;\r
 824                                         }\r
 825                                 }\r
 826                                 else if( pxTask == NULL )\r
 827                                 {\r
 828                                         /* Setting our own priority down means there may now be another\r
 829                                         task of higher priority that is ready to execute. */\r
 830                                         xYieldRequired = pdTRUE;\r
 831                                 }\r
 832                         \r
 833                                 \r
 834 \r
 835                                 #if ( configUSE_MUTEXES == 1 )\r
 836                                 {\r
 837                                         /* Only change the priority being used if the task is not\r
 838                                         currently using an inherited priority. */\r
 839                                         if( pxTCB->uxBasePriority == pxTCB->uxPriority )\r
 840                                         {\r
 841                                                 pxTCB->uxPriority = uxNewPriority;\r
 842                                         }\r
 843                                         \r
 844                                         /* The base priority gets set whatever. */\r
 845                                         pxTCB->uxBasePriority = uxNewPriority;                                  \r
 846                                 }\r
 847                                 #else\r
 848                                 {\r
 849                                         pxTCB->uxPriority = uxNewPriority;\r
 850                                 }\r
 851                                 #endif\r
 852 \r
 853                                 listSET_LIST_ITEM_VALUE( &( pxTCB->xEventListItem ), ( configMAX_PRIORITIES - ( portTickType ) uxNewPriority ) );\r
 854 \r
 855                                 /* If the task is in the blocked or suspended list we need do\r
 856                                 nothing more than change it's priority variable. However, if\r
 857                                 the task is in a ready list it needs to be removed and placed\r
 858                                 in the queue appropriate to its new priority. */\r
 859                                 if( listIS_CONTAINED_WITHIN( &( pxReadyTasksLists[ uxCurrentPriority ] ), &( pxTCB->xGenericListItem ) ) )\r
 860                                 {\r
 861                                         /* The task is currently in its ready list - remove before adding\r
 862                                         it to it's new ready list.  As we are in a critical section we\r
 863                                         can do this even if the scheduler is suspended. */\r
 864                                         vListRemove( &( pxTCB->xGenericListItem ) );\r
 865                                         prvAddTaskToReadyQueue( pxTCB );\r
 866                                 }                       \r
 867                                 \r
 868                                 if( xYieldRequired == pdTRUE )\r
 869                                 {\r
 870                                         taskYIELD();\r
 871                                 }                               \r
 872                         }\r
 873                 }\r
 874                 taskEXIT_CRITICAL();\r
 875         }\r
 876 \r
 877 #endif\r
 878 /*-----------------------------------------------------------*/\r
 879 \r
 880 #if ( INCLUDE_vTaskSuspend == 1 )\r
 881 \r
 882         void vTaskSuspend( xTaskHandle pxTaskToSuspend )\r
 883         {\r
 884         tskTCB *pxTCB;\r
 885 \r
 886                 taskENTER_CRITICAL();\r
 887                 {\r
 888                         /* Ensure a yield is performed if the current task is being\r
 889                         suspended. */\r
 890                         if( pxTaskToSuspend == pxCurrentTCB )\r
 891                         {\r
 892                                 pxTaskToSuspend = NULL;\r
 893                         }\r
 894 \r
 895                         /* If null is passed in here then we are suspending ourselves. */\r
 896                         pxTCB = prvGetTCBFromHandle( pxTaskToSuspend );\r
 897 \r
 898                         traceTASK_SUSPEND( pxTaskToSuspend );\r
 899 \r
 900                         /* Remove task from the ready/delayed list and place in the     suspended list. */\r
 901                         vListRemove( &( pxTCB->xGenericListItem ) );\r
 902 \r
 903                         /* Is the task waiting on an event also? */                                                                                             \r
 904                         if( pxTCB->xEventListItem.pvContainer )\r
 905                         {\r
 906                                 vListRemove( &( pxTCB->xEventListItem ) );\r
 907                         }\r
 908 \r
 909                         vListInsertEnd( ( xList * ) &xSuspendedTaskList, &( pxTCB->xGenericListItem ) );\r
 910                 }\r
 911                 taskEXIT_CRITICAL();\r
 912 \r
 913                 /* We may have just suspended the current task. */\r
 914                 if( ( void * ) pxTaskToSuspend == NULL )\r
 915                 {\r
 916                         taskYIELD();\r
 917                 }\r
 918         }\r
 919 \r
 920 #endif\r
 921 /*-----------------------------------------------------------*/\r
 922 \r
 923 #if ( INCLUDE_vTaskSuspend == 1 )\r
 924 \r
 925         static portBASE_TYPE prvIsTaskSuspended( const tskTCB * const pxTCB )\r
 926         {\r
 927         portBASE_TYPE xReturn = pdFALSE;\r
 928 \r
 929                 /* Is the task we are attempting to resume actually in the\r
 930                 suspended list? */\r
 931                 if( listIS_CONTAINED_WITHIN( &xSuspendedTaskList, &( pxTCB->xGenericListItem ) ) != pdFALSE )\r
 932                 {\r
 933                         /* Has the task already been resumed from within an ISR? */\r
 934                         if( listIS_CONTAINED_WITHIN( &xPendingReadyList, &( pxTCB->xEventListItem ) ) != pdTRUE )\r
 935                         {                       \r
 936                                 /* Is it in the suspended list because it is in the\r
 937                                 Suspended state?  It is possible to be in the suspended\r
 938                                 list because it is blocked on a task with no timeout\r
 939                                 specified. */\r
 940                                 if( listIS_CONTAINED_WITHIN( NULL, &( pxTCB->xEventListItem ) ) == pdTRUE )\r
 941                                 {\r
 942                                         xReturn = pdTRUE;\r
 943                                 }\r
 944                         }\r
 945                 }\r
 946 \r
 947                 return xReturn;\r
 948         }\r
 949 \r
 950 #endif\r
 951 /*-----------------------------------------------------------*/\r
 952 \r
 953 #if ( INCLUDE_vTaskSuspend == 1 )\r
 954 \r
 955         void vTaskResume( xTaskHandle pxTaskToResume )\r
 956         {\r
 957         tskTCB *pxTCB;\r
 958 \r
 959                 /* Remove the task from whichever list it is currently in, and place\r
 960                 it in the ready list. */\r
 961                 pxTCB = ( tskTCB * ) pxTaskToResume;\r
 962 \r
 963                 /* The parameter cannot be NULL as it is impossible to resume the\r
 964                 currently executing task. */\r
 965                 if( pxTCB != NULL )\r
 966                 {\r
 967                         taskENTER_CRITICAL();\r
 968                         {\r
 969                                 if( prvIsTaskSuspended( pxTCB ) == pdTRUE )\r
 970                                 {\r
 971                                         traceTASK_RESUME( pxTCB );\r
 972 \r
 973                                         /* As we are in a critical section we can access the ready\r
 974                                         lists even if the scheduler is suspended. */\r
 975                                         vListRemove(  &( pxTCB->xGenericListItem ) );\r
 976                                         prvAddTaskToReadyQueue( pxTCB );\r
 977 \r
 978                                         /* We may have just resumed a higher priority task. */\r
 979                                         if( pxTCB->uxPriority >= pxCurrentTCB->uxPriority )\r
 980                                         {\r
 981                                                 /* This yield may not cause the task just resumed to run, but\r
 982                                                 will leave the lists in the correct state for the next yield. */\r
 983                                                 taskYIELD();\r
 984                                         }\r
 985                                 }\r
 986                         }\r
 987                         taskEXIT_CRITICAL();\r
 988                 }\r
 989         }\r
 990 \r
 991 #endif\r
 992 \r
 993 /*-----------------------------------------------------------*/\r
 994 \r
 995 #if ( ( INCLUDE_xTaskResumeFromISR == 1 ) && ( INCLUDE_vTaskSuspend == 1 ) )\r
 996 \r
 997         portBASE_TYPE xTaskResumeFromISR( xTaskHandle pxTaskToResume )\r
 998         {\r
 999         portBASE_TYPE xYieldRequired = pdFALSE;\r
1000         tskTCB *pxTCB;\r
1001 \r
1002                 pxTCB = ( tskTCB * ) pxTaskToResume;\r
1003 \r
1004                 if( prvIsTaskSuspended( pxTCB ) == pdTRUE )\r
1005                 {\r
1006                         traceTASK_RESUME_FROM_ISR( pxTCB );\r
1007 \r
1008                         if( uxSchedulerSuspended == ( unsigned portBASE_TYPE ) pdFALSE )\r
1009                         {\r
1010                                 xYieldRequired = ( pxTCB->uxPriority >= pxCurrentTCB->uxPriority );\r
1011                                 vListRemove(  &( pxTCB->xGenericListItem ) );   \r
1012                                 prvAddTaskToReadyQueue( pxTCB );\r
1013                         }\r
1014                         else\r
1015                         {\r
1016                                 /* We cannot access the delayed or ready lists, so will hold this\r
1017                                 task pending until the scheduler is resumed, at which point a\r
1018                                 yield will be performed if necessary. */\r
1019                                 vListInsertEnd( ( xList * ) &( xPendingReadyList ), &( pxTCB->xEventListItem ) );\r
1020                         }\r
1021                 }\r
1022 \r
1023                 return xYieldRequired;\r
1024         }\r
1025 \r
1026 #endif\r
1027 \r
1028 \r
1029 \r
1030 \r
1031 /*-----------------------------------------------------------\r
1032  * PUBLIC SCHEDULER CONTROL documented in task.h\r
1033  *----------------------------------------------------------*/\r
1034 \r
1035 \r
1036 void vTaskStartScheduler( void )\r
1037 {\r
1038 portBASE_TYPE xReturn;\r
1039 \r
1040         /* Add the idle task at the lowest priority. */\r
1041         xReturn = xTaskCreate( prvIdleTask, ( signed portCHAR * ) "IDLE", tskIDLE_STACK_SIZE, ( void * ) NULL, tskIDLE_PRIORITY, ( xTaskHandle * ) NULL );\r
1042 \r
1043         if( xReturn == pdPASS )\r
1044         {\r
1045                 /* Interrupts are turned off here, to ensure a tick does not occur\r
1046                 before or during the call to xPortStartScheduler().  The stacks of\r
1047                 the created tasks contain a status word with interrupts switched on\r
1048                 so interrupts will automatically get re-enabled when the first task\r
1049                 starts to run.\r
1050                 \r
1051                 STEPPING THROUGH HERE USING A DEBUGGER CAN CAUSE BIG PROBLEMS IF THE\r
1052                 DEBUGGER ALLOWS INTERRUPTS TO BE PROCESSED. */\r
1053                 portDISABLE_INTERRUPTS();\r
1054 \r
1055                 xSchedulerRunning = pdTRUE;\r
1056                 xTickCount = ( portTickType ) 0;\r
1057 \r
1058                 /* Setting up the timer tick is hardware specific and thus in the\r
1059                 portable interface. */\r
1060                 if( xPortStartScheduler() )\r
1061                 {\r
1062                         /* Should not reach here as if the scheduler is running the\r
1063                         function will not return. */\r
1064                 }\r
1065                 else\r
1066                 {\r
1067                         /* Should only reach here if a task calls xTaskEndScheduler(). */\r
1068                 }\r
1069         }\r
1070 }\r
1071 /*-----------------------------------------------------------*/\r
1072 \r
1073 void vTaskEndScheduler( void )\r
1074 {\r
1075         /* Stop the scheduler interrupts and call the portable scheduler end\r
1076         routine so the original ISRs can be restored if necessary.  The port\r
1077         layer must ensure interrupts enable     bit is left in the correct state. */\r
1078         portDISABLE_INTERRUPTS();\r
1079         xSchedulerRunning = pdFALSE;\r
1080         vPortEndScheduler();\r
1081 }\r
1082 /*----------------------------------------------------------*/\r
1083 \r
1084 void vTaskSuspendAll( void )\r
1085 {\r
1086         portENTER_CRITICAL();\r
1087                 ++uxSchedulerSuspended;\r
1088         portEXIT_CRITICAL();\r
1089 }\r
1090 /*----------------------------------------------------------*/\r
1091 \r
1092 signed portBASE_TYPE xTaskResumeAll( void )\r
1093 {\r
1094 register tskTCB *pxTCB;\r
1095 signed portBASE_TYPE xAlreadyYielded = pdFALSE;\r
1096 \r
1097         /* It is possible that an ISR caused a task to be removed from an event\r
1098         list while the scheduler was suspended.  If this was the case then the\r
1099         removed task will have been added to the xPendingReadyList.  Once the\r
1100         scheduler has been resumed it is safe to move all the pending ready\r
1101         tasks from this list into their appropriate ready list. */\r
1102         portENTER_CRITICAL();\r
1103         {\r
1104                 --uxSchedulerSuspended;\r
1105 \r
1106                 if( uxSchedulerSuspended == ( unsigned portBASE_TYPE ) pdFALSE )\r
1107                 {                       \r
1108                         if( uxCurrentNumberOfTasks > ( unsigned portBASE_TYPE ) 0 )\r
1109                         {\r
1110                                 portBASE_TYPE xYieldRequired = pdFALSE;\r
1111                                 \r
1112                                 /* Move any readied tasks from the pending list into the\r
1113                                 appropriate ready list. */\r
1114                                 while( ( pxTCB = ( tskTCB * ) listGET_OWNER_OF_HEAD_ENTRY(  ( ( xList * ) &xPendingReadyList ) ) ) != NULL )\r
1115                                 {\r
1116                                         vListRemove( &( pxTCB->xEventListItem ) );\r
1117                                         vListRemove( &( pxTCB->xGenericListItem ) );\r
1118                                         prvAddTaskToReadyQueue( pxTCB );\r
1119                                         \r
1120                                         /* If we have moved a task that has a priority higher than\r
1121                                         the current task then we should yield. */\r
1122                                         if( pxTCB->uxPriority >= pxCurrentTCB->uxPriority )\r
1123                                         {\r
1124                                                 xYieldRequired = pdTRUE;\r
1125                                         }\r
1126                                 }\r
1127 \r
1128                                 /* If any ticks occurred while the scheduler was suspended then\r
1129                                 they should be processed now.  This ensures the tick count does not\r
1130                                 slip, and that any delayed tasks are resumed at the correct time. */\r
1131                                 if( uxMissedTicks > ( unsigned portBASE_TYPE ) 0 )\r
1132                                 {\r
1133                                         while( uxMissedTicks > ( unsigned portBASE_TYPE ) 0 )\r
1134                                         {\r
1135                                                 vTaskIncrementTick();\r
1136                                                 --uxMissedTicks;\r
1137                                         }\r
1138 \r
1139                                         /* As we have processed some ticks it is appropriate to yield\r
1140                                         to ensure the highest priority task that is ready to run is\r
1141                                         the task actually running. */\r
1142                                         #if configUSE_PREEMPTION == 1\r
1143                                         {\r
1144                                                 xYieldRequired = pdTRUE;\r
1145                                         }\r
1146                                         #endif\r
1147                                 }\r
1148                                 \r
1149                                 if( ( xYieldRequired == pdTRUE ) || ( xMissedYield == pdTRUE ) )\r
1150                                 {\r
1151                                         xAlreadyYielded = pdTRUE;\r
1152                                         xMissedYield = pdFALSE;\r
1153                                         taskYIELD();\r
1154                                 }\r
1155                         }\r
1156                 }\r
1157         }\r
1158         portEXIT_CRITICAL();\r
1159 \r
1160         return xAlreadyYielded;\r
1161 }\r
1162 \r
1163 \r
1164 \r
1165 \r
1166 \r
1167 \r
1168 /*-----------------------------------------------------------\r
1169  * PUBLIC TASK UTILITIES documented in task.h\r
1170  *----------------------------------------------------------*/\r
1171 \r
1172 \r
1173 \r
1174 portTickType xTaskGetTickCount( void )\r
1175 {\r
1176 portTickType xTicks;\r
1177 \r
1178         /* Critical section required if running on a 16 bit processor. */\r
1179         taskENTER_CRITICAL();\r
1180         {\r
1181                 xTicks = xTickCount;\r
1182         }\r
1183         taskEXIT_CRITICAL();\r
1184 \r
1185         return xTicks;\r
1186 }\r
1187 /*-----------------------------------------------------------*/\r
1188 \r
1189 unsigned portBASE_TYPE uxTaskGetNumberOfTasks( void )\r
1190 {\r
1191 unsigned portBASE_TYPE uxNumberOfTasks;\r
1192 \r
1193         taskENTER_CRITICAL();\r
1194                 uxNumberOfTasks = uxCurrentNumberOfTasks;\r
1195         taskEXIT_CRITICAL();\r
1196 \r
1197         return uxNumberOfTasks;\r
1198 }\r
1199 /*-----------------------------------------------------------*/\r
1200 \r
1201 #if ( ( configUSE_TRACE_FACILITY == 1 ) && ( INCLUDE_vTaskDelete == 1 ) && ( INCLUDE_vTaskSuspend == 1 ) )\r
1202 \r
1203         void vTaskList( signed portCHAR *pcWriteBuffer )\r
1204         {\r
1205         unsigned portBASE_TYPE uxQueue;\r
1206 \r
1207                 /* This is a VERY costly function that should be used for debug only.\r
1208                 It leaves interrupts disabled for a LONG time. */\r
1209 \r
1210         vTaskSuspendAll();\r
1211                 {\r
1212                         /* Run through all the lists that could potentially contain a TCB and\r
1213                         report the task name, state and stack high water mark. */\r
1214 \r
1215                         pcWriteBuffer[ 0 ] = ( signed portCHAR ) 0x00;\r
1216                         strcat( ( portCHAR * ) pcWriteBuffer, ( const portCHAR * ) "\r\n" );\r
1217 \r
1218                         uxQueue = uxTopUsedPriority + 1;\r
1219 \r
1220                         do\r
1221                         {\r
1222                                 uxQueue--;\r
1223 \r
1224                                 if( !listLIST_IS_EMPTY( &( pxReadyTasksLists[ uxQueue ] ) ) )\r
1225                                 {\r
1226                                         prvListTaskWithinSingleList( pcWriteBuffer, ( xList * ) &( pxReadyTasksLists[ uxQueue ] ), tskREADY_CHAR );                     \r
1227                                 }\r
1228                         }while( uxQueue > ( unsigned portSHORT ) tskIDLE_PRIORITY );\r
1229 \r
1230                         if( !listLIST_IS_EMPTY( pxDelayedTaskList ) )\r
1231                         {\r
1232                                 prvListTaskWithinSingleList( pcWriteBuffer, ( xList * ) pxDelayedTaskList, tskBLOCKED_CHAR );\r
1233                         }\r
1234 \r
1235                         if( !listLIST_IS_EMPTY( pxOverflowDelayedTaskList ) )\r
1236                         {\r
1237                                 prvListTaskWithinSingleList( pcWriteBuffer, ( xList * ) pxOverflowDelayedTaskList, tskBLOCKED_CHAR );\r
1238                         }\r
1239 \r
1240                         if( !listLIST_IS_EMPTY( &xTasksWaitingTermination ) )\r
1241                         {\r
1242                                 prvListTaskWithinSingleList( pcWriteBuffer, ( xList * ) &xTasksWaitingTermination, tskDELETED_CHAR );\r
1243                         }\r
1244 \r
1245                         if( !listLIST_IS_EMPTY( &xSuspendedTaskList ) )\r
1246                         {\r
1247                                 prvListTaskWithinSingleList( pcWriteBuffer, ( xList * ) &xSuspendedTaskList, tskSUSPENDED_CHAR );\r
1248                         }\r
1249                 }\r
1250         xTaskResumeAll();\r
1251         }\r
1252 \r
1253 #endif\r
1254 /*----------------------------------------------------------*/\r
1255 \r
1256 #if ( configUSE_TRACE_FACILITY == 1 )\r
1257 \r
1258         void vTaskStartTrace( signed portCHAR * pcBuffer, unsigned portLONG ulBufferSize )\r
1259         {\r
1260                 portENTER_CRITICAL();\r
1261                 {\r
1262                         pcTraceBuffer = ( signed portCHAR * )pcBuffer;\r
1263                         pcTraceBufferStart = pcBuffer;\r
1264                         pcTraceBufferEnd = pcBuffer + ( ulBufferSize - tskSIZE_OF_EACH_TRACE_LINE );\r
1265                         xTracing = pdTRUE;\r
1266                 }\r
1267                 portEXIT_CRITICAL();\r
1268         }\r
1269 \r
1270 #endif\r
1271 /*----------------------------------------------------------*/\r
1272 \r
1273 #if ( configUSE_TRACE_FACILITY == 1 )\r
1274 \r
1275         unsigned portLONG ulTaskEndTrace( void )\r
1276         {\r
1277         unsigned portLONG ulBufferLength;\r
1278 \r
1279                 portENTER_CRITICAL();\r
1280                         xTracing = pdFALSE;\r
1281                 portEXIT_CRITICAL();\r
1282 \r
1283                 ulBufferLength = ( unsigned portLONG ) ( pcTraceBuffer - pcTraceBufferStart );\r
1284 \r
1285                 return ulBufferLength;\r
1286         }\r
1287 \r
1288 #endif\r
1289 \r
1290 \r
1291 \r
1292 /*-----------------------------------------------------------\r
1293  * SCHEDULER INTERNALS AVAILABLE FOR PORTING PURPOSES\r
1294  * documented in task.h\r
1295  *----------------------------------------------------------*/\r
1296 \r
1297 \r
1298 inline void vTaskIncrementTick( void )\r
1299 {\r
1300         /* Called by the portable layer each time a tick interrupt occurs.\r
1301         Increments the tick then checks to see if the new tick value will cause any\r
1302         tasks to be unblocked. */\r
1303         if( uxSchedulerSuspended == ( unsigned portBASE_TYPE ) pdFALSE )\r
1304         {\r
1305                 ++xTickCount;\r
1306                 if( xTickCount == ( portTickType ) 0 )\r
1307                 {\r
1308                         xList *pxTemp;\r
1309 \r
1310                         /* Tick count has overflowed so we need to swap the delay lists.\r
1311                         If there are any items in pxDelayedTaskList here then there is\r
1312                         an error! */\r
1313                         pxTemp = pxDelayedTaskList;\r
1314                         pxDelayedTaskList = pxOverflowDelayedTaskList;\r
1315                         pxOverflowDelayedTaskList = pxTemp;\r
1316             xNumOfOverflows++;\r
1317                 }\r
1318 \r
1319                 /* See if this tick has made a timeout expire. */\r
1320                 prvCheckDelayedTasks();\r
1321         }\r
1322         else\r
1323         {\r
1324                 ++uxMissedTicks;\r
1325 \r
1326                 /* The tick hook gets called at regular intervals, even if the\r
1327                 scheduler is locked. */\r
1328                 #if ( configUSE_TICK_HOOK == 1 )\r
1329                 {\r
1330                         extern void vApplicationTickHook( void );\r
1331 \r
1332                         vApplicationTickHook();\r
1333                 }\r
1334                 #endif\r
1335         }\r
1336 \r
1337         #if ( configUSE_TICK_HOOK == 1 )\r
1338         {\r
1339                 extern void vApplicationTickHook( void );\r
1340 \r
1341                 /* Guard against the tick hook being called when the missed tick\r
1342                 count is being unwound (when the scheduler is being unlocked. */\r
1343                 if( uxMissedTicks == 0 )\r
1344                 {\r
1345                         vApplicationTickHook();\r
1346                 }\r
1347         }\r
1348         #endif\r
1349 \r
1350         traceTASK_INCREMENT_TICK( xTickCount );\r
1351 }\r
1352 /*-----------------------------------------------------------*/\r
1353 \r
1354 #if ( ( INCLUDE_vTaskCleanUpResources == 1 ) && ( INCLUDE_vTaskSuspend == 1 ) )\r
1355 \r
1356         void vTaskCleanUpResources( void )\r
1357         {\r
1358         unsigned portSHORT usQueue;\r
1359         volatile tskTCB *pxTCB;\r
1360 \r
1361                 usQueue = ( unsigned portSHORT ) uxTopUsedPriority + ( unsigned portSHORT ) 1;\r
1362 \r
1363                 /* Remove any TCB's from the ready queues. */\r
1364                 do\r
1365                 {\r
1366                         usQueue--;\r
1367 \r
1368                         while( !listLIST_IS_EMPTY( &( pxReadyTasksLists[ usQueue ] ) ) )\r
1369                         {\r
1370                                 listGET_OWNER_OF_NEXT_ENTRY( pxTCB, &( pxReadyTasksLists[ usQueue ] ) );\r
1371                                 vListRemove( ( xListItem * ) &( pxTCB->xGenericListItem ) );\r
1372 \r
1373                                 prvDeleteTCB( ( tskTCB * ) pxTCB );\r
1374                         }\r
1375                 }while( usQueue > ( unsigned portSHORT ) tskIDLE_PRIORITY );\r
1376 \r
1377                 /* Remove any TCB's from the delayed queue. */\r
1378                 while( !listLIST_IS_EMPTY( &xDelayedTaskList1 ) )\r
1379                 {\r
1380                         listGET_OWNER_OF_NEXT_ENTRY( pxTCB, &xDelayedTaskList1 );\r
1381                         vListRemove( ( xListItem * ) &( pxTCB->xGenericListItem ) );\r
1382 \r
1383                         prvDeleteTCB( ( tskTCB * ) pxTCB );\r
1384                 }\r
1385 \r
1386                 /* Remove any TCB's from the overflow delayed queue. */\r
1387                 while( !listLIST_IS_EMPTY( &xDelayedTaskList2 ) )\r
1388                 {\r
1389                         listGET_OWNER_OF_NEXT_ENTRY( pxTCB, &xDelayedTaskList2 );\r
1390                         vListRemove( ( xListItem * ) &( pxTCB->xGenericListItem ) );\r
1391 \r
1392                         prvDeleteTCB( ( tskTCB * ) pxTCB );\r
1393                 }\r
1394 \r
1395                 while( !listLIST_IS_EMPTY( &xSuspendedTaskList ) )\r
1396                 {\r
1397                         listGET_OWNER_OF_NEXT_ENTRY( pxTCB, &xSuspendedTaskList );\r
1398                         vListRemove( ( xListItem * ) &( pxTCB->xGenericListItem ) );\r
1399 \r
1400                         prvDeleteTCB( ( tskTCB * ) pxTCB );\r
1401                 }               \r
1402         }\r
1403 \r
1404 #endif\r
1405 /*-----------------------------------------------------------*/\r
1406 \r
1407 void vTaskSwitchContext( void )\r
1408 {\r
1409         if( uxSchedulerSuspended != ( unsigned portBASE_TYPE ) pdFALSE )\r
1410         {\r
1411                 /* The scheduler is currently suspended - do not allow a context\r
1412                 switch. */\r
1413                 xMissedYield = pdTRUE;\r
1414                 return;\r
1415         }\r
1416 \r
1417         taskCHECK_FOR_STACK_OVERFLOW();\r
1418 \r
1419         /* Find the highest priority queue that contains ready tasks. */\r
1420         while( listLIST_IS_EMPTY( &( pxReadyTasksLists[ uxTopReadyPriority ] ) ) )\r
1421         {\r
1422                 --uxTopReadyPriority;\r
1423         }\r
1424 \r
1425         /* listGET_OWNER_OF_NEXT_ENTRY walks through the list, so the tasks of the\r
1426         same priority get an equal share of the processor time. */\r
1427         listGET_OWNER_OF_NEXT_ENTRY( pxCurrentTCB, &( pxReadyTasksLists[ uxTopReadyPriority ] ) );\r
1428 \r
1429         traceTASK_SWITCHED_IN();\r
1430         vWriteTraceToBuffer();\r
1431 }\r
1432 /*-----------------------------------------------------------*/\r
1433 \r
1434 void vTaskPlaceOnEventList( const xList * const pxEventList, portTickType xTicksToWait )\r
1435 {\r
1436 portTickType xTimeToWake;\r
1437 \r
1438         /* THIS FUNCTION MUST BE CALLED WITH INTERRUPTS DISABLED OR THE\r
1439         SCHEDULER SUSPENDED. */\r
1440 \r
1441         /* Place the event list item of the TCB in the appropriate event list.\r
1442         This is placed in the list in priority order so the highest priority task\r
1443         is the first to be woken by the event. */\r
1444         vListInsert( ( xList * ) pxEventList, ( xListItem * ) &( pxCurrentTCB->xEventListItem ) );\r
1445 \r
1446         /* We must remove ourselves from the ready list before adding ourselves\r
1447         to the blocked list as the same list item is used for both lists.  We have\r
1448         exclusive access to the ready lists as the scheduler is locked. */\r
1449         vListRemove( ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );\r
1450 \r
1451 \r
1452         #if ( INCLUDE_vTaskSuspend == 1 )\r
1453         {                       \r
1454                 if( xTicksToWait == portMAX_DELAY )\r
1455                 {\r
1456                         /* Add ourselves to the suspended task list instead of a delayed task\r
1457                         list to ensure we are not woken by a timing event.  We will block\r
1458                         indefinitely. */\r
1459                         vListInsertEnd( ( xList * ) &xSuspendedTaskList, ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );\r
1460                 }\r
1461                 else\r
1462                 {\r
1463                         /* Calculate the time at which the task should be woken if the event does\r
1464                         not occur.  This may overflow but this doesn't matter. */\r
1465                         xTimeToWake = xTickCount + xTicksToWait;\r
1466                 \r
1467                         listSET_LIST_ITEM_VALUE( &( pxCurrentTCB->xGenericListItem ), xTimeToWake );\r
1468                 \r
1469                         if( xTimeToWake < xTickCount )\r
1470                         {\r
1471                                 /* Wake time has overflowed.  Place this item in the overflow list. */\r
1472                                 vListInsert( ( xList * ) pxOverflowDelayedTaskList, ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );\r
1473                         }\r
1474                         else\r
1475                         {\r
1476                                 /* The wake time has not overflowed, so we can use the current block list. */\r
1477                                 vListInsert( ( xList * ) pxDelayedTaskList, ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );\r
1478                         }\r
1479                 }\r
1480         }\r
1481         #else\r
1482         {\r
1483                         /* Calculate the time at which the task should be woken if the event does\r
1484                         not occur.  This may overflow but this doesn't matter. */\r
1485                         xTimeToWake = xTickCount + xTicksToWait;\r
1486                 \r
1487                         listSET_LIST_ITEM_VALUE( &( pxCurrentTCB->xGenericListItem ), xTimeToWake );\r
1488                 \r
1489                         if( xTimeToWake < xTickCount )\r
1490                         {\r
1491                                 /* Wake time has overflowed.  Place this item in the overflow list. */\r
1492                                 vListInsert( ( xList * ) pxOverflowDelayedTaskList, ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );\r
1493                         }\r
1494                         else\r
1495                         {\r
1496                                 /* The wake time has not overflowed, so we can use the current block list. */\r
1497                                 vListInsert( ( xList * ) pxDelayedTaskList, ( xListItem * ) &( pxCurrentTCB->xGenericListItem ) );\r
1498                         }\r
1499         }\r
1500         #endif\r
1501 }\r
1502 /*-----------------------------------------------------------*/\r
1503 \r
1504 signed portBASE_TYPE xTaskRemoveFromEventList( const xList * const pxEventList )\r
1505 {\r
1506 tskTCB *pxUnblockedTCB;\r
1507 portBASE_TYPE xReturn;\r
1508 \r
1509         /* THIS FUNCTION MUST BE CALLED WITH INTERRUPTS DISABLED OR THE\r
1510         SCHEDULER SUSPENDED.  It can also be called from within an ISR. */\r
1511 \r
1512         /* The event list is sorted in priority order, so we can remove the\r
1513         first in the list, remove the TCB from the delayed list, and add\r
1514         it to the ready list.\r
1515         \r
1516         If an event is for a queue that is locked then this function will never\r
1517         get called - the lock count on the queue will get modified instead.  This\r
1518         means we can always expect exclusive access to the event list here. */\r
1519         pxUnblockedTCB = ( tskTCB * ) listGET_OWNER_OF_HEAD_ENTRY( pxEventList );\r
1520         vListRemove( &( pxUnblockedTCB->xEventListItem ) );\r
1521 \r
1522         if( uxSchedulerSuspended == ( unsigned portBASE_TYPE ) pdFALSE )\r
1523         {\r
1524                 vListRemove( &( pxUnblockedTCB->xGenericListItem ) );\r
1525                 prvAddTaskToReadyQueue( pxUnblockedTCB );\r
1526         }\r
1527         else\r
1528         {\r
1529                 /* We cannot access the delayed or ready lists, so will hold this\r
1530                 task pending until the scheduler is resumed. */\r
1531                 vListInsertEnd( ( xList * ) &( xPendingReadyList ), &( pxUnblockedTCB->xEventListItem ) );\r
1532         }\r
1533 \r
1534         if( pxUnblockedTCB->uxPriority >= pxCurrentTCB->uxPriority )\r
1535         {\r
1536                 /* Return true if the task removed from the event list has\r
1537                 a higher priority than the calling task.  This allows\r
1538                 the calling task to know if it should force a context\r
1539                 switch now. */\r
1540                 xReturn = pdTRUE;\r
1541         }\r
1542         else\r
1543         {\r
1544                 xReturn = pdFALSE;\r
1545         }\r
1546 \r
1547         return xReturn;\r
1548 }\r
1549 /*-----------------------------------------------------------*/\r
1550 \r
1551 void vTaskSetTimeOutState( xTimeOutType * const pxTimeOut )\r
1552 {\r
1553     pxTimeOut->xOverflowCount = xNumOfOverflows;\r
1554     pxTimeOut->xTimeOnEntering = xTickCount;\r
1555 }\r
1556 /*-----------------------------------------------------------*/\r
1557 \r
1558 portBASE_TYPE xTaskCheckForTimeOut( xTimeOutType * const pxTimeOut, portTickType * const pxTicksToWait )\r
1559 {\r
1560 portBASE_TYPE xReturn;\r
1561 \r
1562         #if ( INCLUDE_vTaskSuspend == 1 )\r
1563                 /* If INCLUDE_vTaskSuspend is set to 1 and the block time specified is\r
1564                 the maximum block time then the task should block indefinitely, and\r
1565                 therefore never time out. */\r
1566                 if( *pxTicksToWait == portMAX_DELAY )\r
1567                 {\r
1568                         xReturn = pdFALSE;\r
1569                 }\r
1570                 else /* We are not blocking indefinitely, perform the checks below. */\r
1571         #endif\r
1572 \r
1573     if( ( xNumOfOverflows != pxTimeOut->xOverflowCount ) && ( xTickCount >= pxTimeOut->xTimeOnEntering ) )\r
1574     {\r
1575         /* The tick count is greater than the time at which vTaskSetTimeout()\r
1576                 was called, but has also overflowed since vTaskSetTimeOut() was called.\r
1577         It must have wrapped all the way around and gone past us again. This\r
1578         passed since vTaskSetTimeout() was called. */\r
1579         xReturn = pdTRUE;\r
1580     }\r
1581     else if( ( xTickCount - pxTimeOut->xTimeOnEntering ) < *pxTicksToWait )\r
1582     {\r
1583         /* Not a genuine timeout. Adjust parameters for time remaining. */\r
1584         *pxTicksToWait -= ( xTickCount - pxTimeOut->xTimeOnEntering );\r
1585         vTaskSetTimeOutState( pxTimeOut );\r
1586         xReturn = pdFALSE;\r
1587     }\r
1588     else\r
1589     {\r
1590         xReturn = pdTRUE;\r
1591     }\r
1592 \r
1593     return xReturn;\r
1594 }\r
1595 /*-----------------------------------------------------------*/\r
1596 \r
1597 void vTaskMissedYield( void )\r
1598 {\r
1599         xMissedYield = pdTRUE;\r
1600 }\r
1601 \r
1602 /*\r
1603  * -----------------------------------------------------------\r
1604  * The Idle task.\r
1605  * ----------------------------------------------------------\r
1606  *\r
1607  * The portTASK_FUNCTION() macro is used to allow port/compiler specific\r
1608  * language extensions.  The equivalent prototype for this function is:\r
1609  *\r
1610  * void prvIdleTask( void *pvParameters );\r
1611  *\r
1612  */\r
1613 static portTASK_FUNCTION( prvIdleTask, pvParameters )\r
1614 {\r
1615         /* Stop warnings. */\r
1616         ( void ) pvParameters;\r
1617 \r
1618         for( ;; )\r
1619         {\r
1620                 /* See if any tasks have been deleted. */\r
1621                 prvCheckTasksWaitingTermination();\r
1622 \r
1623                 #if ( configUSE_PREEMPTION == 0 )\r
1624                 {\r
1625                         /* If we are not using preemption we keep forcing a task switch to\r
1626                         see if any other task has become available.  If we are using\r
1627                         preemption we don't need to do this as any task becoming available\r
1628                         will automatically get the processor anyway. */\r
1629                         taskYIELD();    \r
1630                 }\r
1631                 #endif\r
1632 \r
1633                 #if ( ( configUSE_PREEMPTION == 1 ) && ( configIDLE_SHOULD_YIELD == 1 ) )\r
1634                 {\r
1635                         /* When using preemption tasks of equal priority will be\r
1636                         timesliced.  If a task that is sharing the idle priority is ready\r
1637                         to run then the idle task should yield before the end of the\r
1638                         timeslice.\r
1639                         \r
1640                         A critical region is not required here as we are just reading from\r
1641                         the list, and an occasional incorrect value will not matter.  If\r
1642                         the ready list at the idle priority contains more than one task\r
1643                         then a task other than the idle task is ready to execute. */\r
1644                         if( listCURRENT_LIST_LENGTH( &( pxReadyTasksLists[ tskIDLE_PRIORITY ] ) ) > ( unsigned portBASE_TYPE ) 1 )\r
1645                         {\r
1646                                 taskYIELD();\r
1647                         }\r
1648                 }\r
1649                 #endif\r
1650 \r
1651                 #if ( configUSE_IDLE_HOOK == 1 )\r
1652                 {\r
1653                         extern void vApplicationIdleHook( void );\r
1654 \r
1655                         /* Call the user defined function from within the idle task.  This\r
1656                         allows the application designer to add background functionality\r
1657                         without the overhead of a separate task.\r
1658                         NOTE: vApplicationIdleHook() MUST NOT, UNDER ANY CIRCUMSTANCES,\r
1659                         CALL A FUNCTION THAT MIGHT BLOCK. */\r
1660                         vApplicationIdleHook();\r
1661                 }\r
1662                 #endif\r
1663         }\r
1664 } /*lint !e715 pvParameters is not accessed but all task functions require the same prototype. */\r
1665 \r
1666 \r
1667 \r
1668 \r
1669 \r
1670 \r
1671 \r
1672 /*-----------------------------------------------------------\r
1673  * File private functions documented at the top of the file.\r
1674  *----------------------------------------------------------*/\r
1675 \r
1676 \r
1677 \r
1678 static void prvInitialiseTCBVariables( tskTCB *pxTCB, const signed portCHAR * const pcName, unsigned portBASE_TYPE uxPriority )\r
1679 {\r
1680         /* Store the function name in the TCB. */\r
1681         strncpy( ( char * ) pxTCB->pcTaskName, ( const char * ) pcName, ( unsigned portSHORT ) configMAX_TASK_NAME_LEN );\r
1682         pxTCB->pcTaskName[ ( unsigned portSHORT ) configMAX_TASK_NAME_LEN - ( unsigned portSHORT ) 1 ] = '\0';\r
1683 \r
1684         #if ( portCRITICAL_NESTING_IN_TCB == 1 )\r
1685         {\r
1686                 pxTCB->uxCriticalNesting = ( unsigned portBASE_TYPE ) 0;\r
1687         }\r
1688         #endif\r
1689 \r
1690         /* This is used as an array index so must ensure it's not too large. */\r
1691         if( uxPriority >= configMAX_PRIORITIES )\r
1692         {\r
1693                 uxPriority = configMAX_PRIORITIES - 1;\r
1694         }\r
1695 \r
1696         pxTCB->uxPriority = uxPriority;\r
1697         #if ( configUSE_MUTEXES == 1 )\r
1698         {\r
1699                 pxTCB->uxBasePriority = uxPriority;\r
1700         }\r
1701         #endif\r
1702 \r
1703         vListInitialiseItem( &( pxTCB->xGenericListItem ) );\r
1704         vListInitialiseItem( &( pxTCB->xEventListItem ) );\r
1705 \r
1706         /* Set the pxTCB as a link back from the xListItem.  This is so we can get\r
1707         back to the containing TCB from a generic item in a list. */\r
1708         listSET_LIST_ITEM_OWNER( &( pxTCB->xGenericListItem ), pxTCB );\r
1709 \r
1710         /* Event lists are always in priority order. */\r
1711         listSET_LIST_ITEM_VALUE( &( pxTCB->xEventListItem ), configMAX_PRIORITIES - ( portTickType ) uxPriority );\r
1712         listSET_LIST_ITEM_OWNER( &( pxTCB->xEventListItem ), pxTCB );\r
1713 }\r
1714 /*-----------------------------------------------------------*/\r
1715 \r
1716 static void prvInitialiseTaskLists( void )\r
1717 {\r
1718 unsigned portBASE_TYPE uxPriority;\r
1719 \r
1720         for( uxPriority = 0; uxPriority < configMAX_PRIORITIES; uxPriority++ )\r
1721         {\r
1722                 vListInitialise( ( xList * ) &( pxReadyTasksLists[ uxPriority ] ) );\r
1723         }\r
1724 \r
1725         vListInitialise( ( xList * ) &xDelayedTaskList1 );\r
1726         vListInitialise( ( xList * ) &xDelayedTaskList2 );\r
1727         vListInitialise( ( xList * ) &xPendingReadyList );\r
1728 \r
1729         #if ( INCLUDE_vTaskDelete == 1 )\r
1730         {\r
1731                 vListInitialise( ( xList * ) &xTasksWaitingTermination );\r
1732         }\r
1733         #endif\r
1734 \r
1735         #if ( INCLUDE_vTaskSuspend == 1 )\r
1736         {\r
1737                 vListInitialise( ( xList * ) &xSuspendedTaskList );\r
1738         }\r
1739         #endif\r
1740 \r
1741         /* Start with pxDelayedTaskList using list1 and the pxOverflowDelayedTaskList\r
1742         using list2. */\r
1743         pxDelayedTaskList = &xDelayedTaskList1;\r
1744         pxOverflowDelayedTaskList = &xDelayedTaskList2;\r
1745 }\r
1746 /*-----------------------------------------------------------*/\r
1747 \r
1748 static void prvCheckTasksWaitingTermination( void )\r
1749 {                                                       \r
1750         #if ( INCLUDE_vTaskDelete == 1 )\r
1751         {                               \r
1752                 portBASE_TYPE xListIsEmpty;\r
1753 \r
1754                 /* ucTasksDeleted is used to prevent vTaskSuspendAll() being called\r
1755                 too often in the idle task. */\r
1756                 if( uxTasksDeleted > ( unsigned portBASE_TYPE ) 0 )\r
1757                 {\r
1758                         vTaskSuspendAll();\r
1759                                 xListIsEmpty = listLIST_IS_EMPTY( &xTasksWaitingTermination );                          \r
1760                         xTaskResumeAll();\r
1761 \r
1762                         if( !xListIsEmpty )\r
1763                         {\r
1764                                 tskTCB *pxTCB;\r
1765 \r
1766                                 portENTER_CRITICAL();\r
1767                                 {                       \r
1768                                         pxTCB = ( tskTCB * ) listGET_OWNER_OF_HEAD_ENTRY( ( ( xList * ) &xTasksWaitingTermination ) );\r
1769                                         vListRemove( &( pxTCB->xGenericListItem ) );\r
1770                                         --uxCurrentNumberOfTasks;\r
1771                                         --uxTasksDeleted;\r
1772                                 }\r
1773                                 portEXIT_CRITICAL();\r
1774 \r
1775                                 prvDeleteTCB( pxTCB );\r
1776                         }\r
1777                 }\r
1778         }\r
1779         #endif\r
1780 }\r
1781 /*-----------------------------------------------------------*/\r
1782 \r
1783 static tskTCB *prvAllocateTCBAndStack( unsigned portSHORT usStackDepth )\r
1784 {\r
1785 tskTCB *pxNewTCB;\r
1786 \r
1787         /* Allocate space for the TCB.  Where the memory comes from depends on\r
1788         the implementation of the port malloc function. */\r
1789         pxNewTCB = ( tskTCB * ) pvPortMalloc( sizeof( tskTCB ) );\r
1790 \r
1791         if( pxNewTCB != NULL )\r
1792         {\r
1793                 /* Allocate space for the stack used by the task being created.\r
1794                 The base of the stack memory stored in the TCB so the task can\r
1795                 be deleted later if required. */\r
1796                 pxNewTCB->pxStack = ( portSTACK_TYPE * ) pvPortMalloc( ( ( size_t )usStackDepth ) * sizeof( portSTACK_TYPE ) );\r
1797 \r
1798                 if( pxNewTCB->pxStack == NULL )\r
1799                 {\r
1800                         /* Could not allocate the stack.  Delete the allocated TCB. */\r
1801                         vPortFree( pxNewTCB );                  \r
1802                         pxNewTCB = NULL;                        \r
1803                 }               \r
1804                 else\r
1805                 {\r
1806                         /* Just to help debugging. */\r
1807                         memset( pxNewTCB->pxStack, tskSTACK_FILL_BYTE, usStackDepth * sizeof( portSTACK_TYPE ) );\r
1808                 }\r
1809         }\r
1810 \r
1811         return pxNewTCB;\r
1812 }\r
1813 /*-----------------------------------------------------------*/\r
1814 \r
1815 #if ( configUSE_TRACE_FACILITY == 1 )\r
1816 \r
1817         static void prvListTaskWithinSingleList( const signed portCHAR *pcWriteBuffer, xList *pxList, signed portCHAR cStatus )\r
1818         {\r
1819         volatile tskTCB *pxNextTCB, *pxFirstTCB;\r
1820         static portCHAR pcStatusString[ 50 ];\r
1821         unsigned portSHORT usStackRemaining;\r
1822 \r
1823                 /* Write the details of all the TCB's in pxList into the buffer. */\r
1824                 listGET_OWNER_OF_NEXT_ENTRY( pxFirstTCB, pxList );\r
1825                 do\r
1826                 {\r
1827                         listGET_OWNER_OF_NEXT_ENTRY( pxNextTCB, pxList );\r
1828                         usStackRemaining = usTaskCheckFreeStackSpace( ( unsigned portCHAR * ) pxNextTCB->pxStack );\r
1829                         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
1830                         strcat( ( portCHAR * ) pcWriteBuffer, ( portCHAR * ) pcStatusString );\r
1831 \r
1832                 } while( pxNextTCB != pxFirstTCB );\r
1833         }\r
1834 \r
1835 #endif\r
1836 /*-----------------------------------------------------------*/\r
1837 \r
1838 #if ( ( configUSE_TRACE_FACILITY == 1 ) || ( INCLUDE_uxTaskGetStackHighWaterMark == 1 ) )\r
1839 \r
1840         unsigned portSHORT usTaskCheckFreeStackSpace( const unsigned portCHAR * pucStackByte )\r
1841         {\r
1842         register unsigned portSHORT usCount = 0;\r
1843 \r
1844                 while( *pucStackByte == tskSTACK_FILL_BYTE )\r
1845                 {\r
1846                         pucStackByte -= portSTACK_GROWTH;\r
1847                         usCount++;\r
1848                 }\r
1849 \r
1850                 usCount /= sizeof( portSTACK_TYPE );\r
1851 \r
1852                 return usCount;\r
1853         }\r
1854 \r
1855 #endif\r
1856 /*-----------------------------------------------------------*/\r
1857 \r
1858 #if ( INCLUDE_uxTaskGetStackHighWaterMark == 1 )\r
1859 \r
1860         unsigned portBASE_TYPE uxTaskGetStackHighWaterMark( void )\r
1861         {\r
1862                 return usTaskCheckFreeStackSpace( pxCurrentTCB->pxStack );\r
1863         }\r
1864 \r
1865 #endif\r
1866 /*-----------------------------------------------------------*/\r
1867 \r
1868 #if ( ( INCLUDE_vTaskDelete == 1 ) || ( INCLUDE_vTaskCleanUpResources == 1 ) )\r
1869 \r
1870         static void prvDeleteTCB( tskTCB *pxTCB )\r
1871         {\r
1872                 /* Free up the memory allocated by the scheduler for the task.  It is up to\r
1873                 the task to free any memory allocated at the application level. */\r
1874                 vPortFree( pxTCB->pxStack );\r
1875                 vPortFree( pxTCB );\r
1876         }\r
1877 \r
1878 #endif\r
1879 \r
1880 \r
1881 /*-----------------------------------------------------------*/\r
1882 \r
1883 #if ( INCLUDE_xTaskGetCurrentTaskHandle == 1 )\r
1884 \r
1885         xTaskHandle xTaskGetCurrentTaskHandle( void )\r
1886         {\r
1887         xTaskHandle xReturn;\r
1888 \r
1889                 portENTER_CRITICAL();\r
1890                 {\r
1891                         xReturn = ( xTaskHandle ) pxCurrentTCB;\r
1892                 }\r
1893                 portEXIT_CRITICAL();\r
1894 \r
1895                 return xReturn;\r
1896         }\r
1897 \r
1898 #endif\r
1899 \r
1900 /*-----------------------------------------------------------*/\r
1901 \r
1902 #if ( INCLUDE_xTaskGetSchedulerState == 1 )\r
1903 \r
1904         portBASE_TYPE xTaskGetSchedulerState( void )\r
1905         {\r
1906         portBASE_TYPE xReturn;\r
1907         \r
1908                 if( xSchedulerRunning == pdFALSE )\r
1909                 {\r
1910                         xReturn = taskSCHEDULER_NOT_STARTED;\r
1911                 }\r
1912                 else\r
1913                 {\r
1914                         if( uxSchedulerSuspended == ( unsigned portBASE_TYPE ) pdFALSE )\r
1915                         {\r
1916                                 xReturn = taskSCHEDULER_RUNNING;\r
1917                         }\r
1918                         else\r
1919                         {\r
1920                                 xReturn = taskSCHEDULER_SUSPENDED;\r
1921                         }\r
1922                 }\r
1923                 \r
1924                 return xReturn;\r
1925         }\r
1926 \r
1927 #endif\r
1928 /*-----------------------------------------------------------*/\r
1929 \r
1930 #if ( configUSE_MUTEXES == 1 )\r
1931         \r
1932         void vTaskPriorityInherit( xTaskHandle * const pxMutexHolder )\r
1933         {\r
1934         tskTCB * const pxTCB = ( tskTCB * ) pxMutexHolder;\r
1935 \r
1936                 if( pxTCB->uxPriority < pxCurrentTCB->uxPriority )\r
1937                 {\r
1938                         /* Adjust the mutex holder state to account for its new priority. */\r
1939                         listSET_LIST_ITEM_VALUE( &( pxTCB->xEventListItem ), configMAX_PRIORITIES - ( portTickType ) pxCurrentTCB->uxPriority );\r
1940 \r
1941                         /* If the task being modified is in the ready state it will need to\r
1942                         be moved in to a new list. */\r
1943                         if( listIS_CONTAINED_WITHIN( &( pxReadyTasksLists[ pxTCB->uxPriority ] ), &( pxTCB->xGenericListItem ) ) )\r
1944                         {\r
1945                                 vListRemove( &( pxTCB->xGenericListItem ) );\r
1946 \r
1947                                 /* Inherit the priority before being moved into the new list. */\r
1948                                 pxTCB->uxPriority = pxCurrentTCB->uxPriority;\r
1949                                 prvAddTaskToReadyQueue( pxTCB );\r
1950                         }\r
1951                         else\r
1952                         {\r
1953                                 /* Just inherit the priority. */\r
1954                                 pxTCB->uxPriority = pxCurrentTCB->uxPriority;\r
1955                         }\r
1956                 }\r
1957         }\r
1958 \r
1959 #endif\r
1960 /*-----------------------------------------------------------*/\r
1961 \r
1962 #if ( configUSE_MUTEXES == 1 )  \r
1963 \r
1964         void vTaskPriorityDisinherit( xTaskHandle * const pxMutexHolder )\r
1965         {\r
1966         tskTCB * const pxTCB = ( tskTCB * ) pxMutexHolder;\r
1967 \r
1968                 if( pxMutexHolder != NULL )\r
1969                 {\r
1970                         if( pxTCB->uxPriority != pxTCB->uxBasePriority )\r
1971                         {\r
1972                                 /* We must be the running task to be able to give the mutex back.\r
1973                                 Remove ourselves from the ready list we currently appear in. */\r
1974                                 vListRemove( &( pxTCB->xGenericListItem ) );\r
1975 \r
1976                                 /* Disinherit the priority before adding ourselves into the new\r
1977                                 ready list. */\r
1978                                 pxTCB->uxPriority = pxTCB->uxBasePriority;\r
1979                                 listSET_LIST_ITEM_VALUE( &( pxTCB->xEventListItem ), configMAX_PRIORITIES - ( portTickType ) pxTCB->uxPriority );\r
1980                                 prvAddTaskToReadyQueue( pxTCB );\r
1981                         }\r
1982                 }\r
1983         }\r
1984 \r
1985 #endif\r
1986 /*-----------------------------------------------------------*/\r
1987 \r
1988 #if ( portCRITICAL_NESTING_IN_TCB == 1 )\r
1989 \r
1990         void vTaskEnterCritical( void )\r
1991         {\r
1992                 portDISABLE_INTERRUPTS();\r
1993 \r
1994                 if( xSchedulerRunning != pdFALSE )\r
1995                 {\r
1996                         pxCurrentTCB->uxCriticalNesting++;\r
1997                 }\r
1998         }\r
1999 \r
2000 #endif\r
2001 /*-----------------------------------------------------------*/\r
2002 \r
2003 #if ( portCRITICAL_NESTING_IN_TCB == 1 )\r
2004 \r
2005 void vTaskExitCritical( void )\r
2006 {\r
2007         if( xSchedulerRunning != pdFALSE )\r
2008         {\r
2009                 if( pxCurrentTCB->uxCriticalNesting > 0 )\r
2010                 {\r
2011                         pxCurrentTCB->uxCriticalNesting--;\r
2012 \r
2013                         if( pxCurrentTCB->uxCriticalNesting == 0 )\r
2014                         {\r
2015                                 portENABLE_INTERRUPTS();\r
2016                         }\r
2017                 }\r
2018         }\r
2019 }\r
2020 \r
2021 #endif\r
2022 /*-----------------------------------------------------------*/\r
2023 \r
2024 \r
2025         \r
2026 \r