2 * FreeRTOS Kernel <DEVELOPMENT BRANCH>
3 * Copyright (C) 2021 Amazon.com, Inc. or its affiliates. All Rights Reserved.
5 * SPDX-License-Identifier: MIT
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24 * https://www.FreeRTOS.org
25 * https://github.com/FreeRTOS
33 #ifndef INC_FREERTOS_H
34 #error "include FreeRTOS.h must appear in source files before include task.h"
45 /*-----------------------------------------------------------
46 * MACROS AND DEFINITIONS
47 *----------------------------------------------------------*/
50 * If tskKERNEL_VERSION_NUMBER ends with + it represents the version in development
51 * after the numbered release.
53 * The tskKERNEL_VERSION_MAJOR, tskKERNEL_VERSION_MINOR, tskKERNEL_VERSION_BUILD
54 * values will reflect the last released version number.
56 #define tskKERNEL_VERSION_NUMBER "V10.4.4+"
57 #define tskKERNEL_VERSION_MAJOR 10
58 #define tskKERNEL_VERSION_MINOR 4
59 #define tskKERNEL_VERSION_BUILD 4
61 /* MPU region parameters passed in ulParameters
62 * of MemoryRegion_t struct. */
63 #define tskMPU_REGION_READ_ONLY ( 1UL << 0UL )
64 #define tskMPU_REGION_READ_WRITE ( 1UL << 1UL )
65 #define tskMPU_REGION_EXECUTE_NEVER ( 1UL << 2UL )
66 #define tskMPU_REGION_NORMAL_MEMORY ( 1UL << 3UL )
67 #define tskMPU_REGION_DEVICE_MEMORY ( 1UL << 4UL )
69 /* The direct to task notification feature used to have only a single notification
70 * per task. Now there is an array of notifications per task that is dimensioned by
71 * configTASK_NOTIFICATION_ARRAY_ENTRIES. For backward compatibility, any use of the
72 * original direct to task notification defaults to using the first index in the
74 #define tskDEFAULT_INDEX_TO_NOTIFY ( 0 )
79 * Type by which tasks are referenced. For example, a call to xTaskCreate
80 * returns (via a pointer parameter) an TaskHandle_t variable that can then
81 * be used as a parameter to vTaskDelete to delete the task.
83 * \defgroup TaskHandle_t TaskHandle_t
86 struct tskTaskControlBlock; /* The old naming convention is used to prevent breaking kernel aware debuggers. */
87 typedef struct tskTaskControlBlock * TaskHandle_t;
90 * Defines the prototype to which the application task hook function must
93 typedef BaseType_t (* TaskHookFunction_t)( void * );
95 /* Task states returned by eTaskGetState. */
98 eRunning = 0, /* A task is querying the state of itself, so must be running. */
99 eReady, /* The task being queried is in a ready or pending ready list. */
100 eBlocked, /* The task being queried is in the Blocked state. */
101 eSuspended, /* The task being queried is in the Suspended state, or is in the Blocked state with an infinite time out. */
102 eDeleted, /* The task being queried has been deleted, but its TCB has not yet been freed. */
103 eInvalid /* Used as an 'invalid state' value. */
106 /* Actions that can be performed when vTaskNotify() is called. */
109 eNoAction = 0, /* Notify the task without updating its notify value. */
110 eSetBits, /* Set bits in the task's notification value. */
111 eIncrement, /* Increment the task's notification value. */
112 eSetValueWithOverwrite, /* Set the task's notification value to a specific value even if the previous value has not yet been read by the task. */
113 eSetValueWithoutOverwrite /* Set the task's notification value if the previous value has been read by the task. */
117 * Used internally only.
119 typedef struct xTIME_OUT
121 BaseType_t xOverflowCount;
122 TickType_t xTimeOnEntering;
126 * Defines the memory ranges allocated to the task when an MPU is used.
128 typedef struct xMEMORY_REGION
130 void * pvBaseAddress;
131 uint32_t ulLengthInBytes;
132 uint32_t ulParameters;
136 * Parameters required to create an MPU protected task.
138 typedef struct xTASK_PARAMETERS
140 TaskFunction_t pvTaskCode;
141 const char * pcName; /*lint !e971 Unqualified char types are allowed for strings and single characters only. */
142 configSTACK_DEPTH_TYPE usStackDepth;
144 UBaseType_t uxPriority;
145 StackType_t * puxStackBuffer;
146 MemoryRegion_t xRegions[ portNUM_CONFIGURABLE_REGIONS ];
147 #if ( ( portUSING_MPU_WRAPPERS == 1 ) && ( configSUPPORT_STATIC_ALLOCATION == 1 ) )
148 StaticTask_t * const pxTaskBuffer;
152 /* Used with the uxTaskGetSystemState() function to return the state of each task
154 typedef struct xTASK_STATUS
156 TaskHandle_t xHandle; /* The handle of the task to which the rest of the information in the structure relates. */
157 const char * pcTaskName; /* A pointer to the task's name. This value will be invalid if the task was deleted since the structure was populated! */ /*lint !e971 Unqualified char types are allowed for strings and single characters only. */
158 UBaseType_t xTaskNumber; /* A number unique to the task. */
159 eTaskState eCurrentState; /* The state in which the task existed when the structure was populated. */
160 UBaseType_t uxCurrentPriority; /* The priority at which the task was running (may be inherited) when the structure was populated. */
161 UBaseType_t uxBasePriority; /* The priority to which the task will return if the task's current priority has been inherited to avoid unbounded priority inversion when obtaining a mutex. Only valid if configUSE_MUTEXES is defined as 1 in FreeRTOSConfig.h. */
162 configRUN_TIME_COUNTER_TYPE ulRunTimeCounter; /* The total run time allocated to the task so far, as defined by the run time stats clock. See https://www.FreeRTOS.org/rtos-run-time-stats.html. Only valid when configGENERATE_RUN_TIME_STATS is defined as 1 in FreeRTOSConfig.h. */
163 StackType_t * pxStackBase; /* Points to the lowest address of the task's stack area. */
164 #if ( ( portSTACK_GROWTH > 0 ) && ( configRECORD_STACK_HIGH_ADDRESS == 1 ) )
165 StackType_t * pxTopOfStack; /* Points to the top address of the task's stack area. */
166 StackType_t * pxEndOfStack; /* Points to the end address of the task's stack area. */
168 configSTACK_DEPTH_TYPE usStackHighWaterMark; /* The minimum amount of stack space that has remained for the task since the task was created. The closer this value is to zero the closer the task has come to overflowing its stack. */
171 /* Possible return values for eTaskConfirmSleepModeStatus(). */
174 eAbortSleep = 0, /* A task has been made ready or a context switch pended since portSUPPRESS_TICKS_AND_SLEEP() was called - abort entering a sleep mode. */
175 eStandardSleep, /* Enter a sleep mode that will not last any longer than the expected idle time. */
176 #if ( INCLUDE_vTaskSuspend == 1 )
177 eNoTasksWaitingTimeout /* No tasks are waiting for a timeout so it is safe to enter a sleep mode that can only be exited by an external interrupt. */
178 #endif /* INCLUDE_vTaskSuspend */
182 * Defines the priority used by the idle task. This must not be modified.
186 #define tskIDLE_PRIORITY ( ( UBaseType_t ) 0U )
191 * Macro for forcing a context switch.
193 * \defgroup taskYIELD taskYIELD
194 * \ingroup SchedulerControl
196 #define taskYIELD() portYIELD()
201 * Macro to mark the start of a critical code region. Preemptive context
202 * switches cannot occur when in a critical region.
204 * NOTE: This may alter the stack (depending on the portable implementation)
205 * so must be used with care!
207 * \defgroup taskENTER_CRITICAL taskENTER_CRITICAL
208 * \ingroup SchedulerControl
210 #define taskENTER_CRITICAL() portENTER_CRITICAL()
211 #define taskENTER_CRITICAL_FROM_ISR() portSET_INTERRUPT_MASK_FROM_ISR()
216 * Macro to mark the end of a critical code region. Preemptive context
217 * switches cannot occur when in a critical region.
219 * NOTE: This may alter the stack (depending on the portable implementation)
220 * so must be used with care!
222 * \defgroup taskEXIT_CRITICAL taskEXIT_CRITICAL
223 * \ingroup SchedulerControl
225 #define taskEXIT_CRITICAL() portEXIT_CRITICAL()
226 #define taskEXIT_CRITICAL_FROM_ISR( x ) portCLEAR_INTERRUPT_MASK_FROM_ISR( x )
231 * Macro to disable all maskable interrupts.
233 * \defgroup taskDISABLE_INTERRUPTS taskDISABLE_INTERRUPTS
234 * \ingroup SchedulerControl
236 #define taskDISABLE_INTERRUPTS() portDISABLE_INTERRUPTS()
241 * Macro to enable microcontroller interrupts.
243 * \defgroup taskENABLE_INTERRUPTS taskENABLE_INTERRUPTS
244 * \ingroup SchedulerControl
246 #define taskENABLE_INTERRUPTS() portENABLE_INTERRUPTS()
248 /* Definitions returned by xTaskGetSchedulerState(). taskSCHEDULER_SUSPENDED is
249 * 0 to generate more optimal code when configASSERT() is defined as the constant
250 * is used in assert() statements. */
251 #define taskSCHEDULER_SUSPENDED ( ( BaseType_t ) 0 )
252 #define taskSCHEDULER_NOT_STARTED ( ( BaseType_t ) 1 )
253 #define taskSCHEDULER_RUNNING ( ( BaseType_t ) 2 )
256 /*-----------------------------------------------------------
258 *----------------------------------------------------------*/
263 * BaseType_t xTaskCreate(
264 * TaskFunction_t pxTaskCode,
265 * const char *pcName,
266 * configSTACK_DEPTH_TYPE usStackDepth,
267 * void *pvParameters,
268 * UBaseType_t uxPriority,
269 * TaskHandle_t *pxCreatedTask
273 * Create a new task and add it to the list of tasks that are ready to run.
275 * Internally, within the FreeRTOS implementation, tasks use two blocks of
276 * memory. The first block is used to hold the task's data structures. The
277 * second block is used by the task as its stack. If a task is created using
278 * xTaskCreate() then both blocks of memory are automatically dynamically
279 * allocated inside the xTaskCreate() function. (see
280 * https://www.FreeRTOS.org/a00111.html). If a task is created using
281 * xTaskCreateStatic() then the application writer must provide the required
282 * memory. xTaskCreateStatic() therefore allows a task to be created without
283 * using any dynamic memory allocation.
285 * See xTaskCreateStatic() for a version that does not use any dynamic memory
288 * xTaskCreate() can only be used to create a task that has unrestricted
289 * access to the entire microcontroller memory map. Systems that include MPU
290 * support can alternatively create an MPU constrained task using
291 * xTaskCreateRestricted().
293 * @param pxTaskCode Pointer to the task entry function. Tasks
294 * must be implemented to never return (i.e. continuous loop).
296 * @param pcName A descriptive name for the task. This is mainly used to
297 * facilitate debugging. Max length defined by configMAX_TASK_NAME_LEN - default
300 * @param usStackDepth The size of the task stack specified as the number of
301 * variables the stack can hold - not the number of bytes. For example, if
302 * the stack is 16 bits wide and usStackDepth is defined as 100, 200 bytes
303 * will be allocated for stack storage.
305 * @param pvParameters Pointer that will be used as the parameter for the task
308 * @param uxPriority The priority at which the task should run. Systems that
309 * include MPU support can optionally create tasks in a privileged (system)
310 * mode by setting bit portPRIVILEGE_BIT of the priority parameter. For
311 * example, to create a privileged task at priority 2 the uxPriority parameter
312 * should be set to ( 2 | portPRIVILEGE_BIT ).
314 * @param pxCreatedTask Used to pass back a handle by which the created task
317 * @return pdPASS if the task was successfully created and added to a ready
318 * list, otherwise an error code defined in the file projdefs.h
322 * // Task to be created.
323 * void vTaskCode( void * pvParameters )
327 * // Task code goes here.
331 * // Function that creates a task.
332 * void vOtherFunction( void )
334 * static uint8_t ucParameterToPass;
335 * TaskHandle_t xHandle = NULL;
337 * // Create the task, storing the handle. Note that the passed parameter ucParameterToPass
338 * // must exist for the lifetime of the task, so in this case is declared static. If it was just an
339 * // an automatic stack variable it might no longer exist, or at least have been corrupted, by the time
340 * // the new task attempts to access it.
341 * xTaskCreate( vTaskCode, "NAME", STACK_SIZE, &ucParameterToPass, tskIDLE_PRIORITY, &xHandle );
342 * configASSERT( xHandle );
344 * // Use the handle to delete the task.
345 * if( xHandle != NULL )
347 * vTaskDelete( xHandle );
351 * \defgroup xTaskCreate xTaskCreate
354 #if ( configSUPPORT_DYNAMIC_ALLOCATION == 1 )
355 BaseType_t xTaskCreate( TaskFunction_t pxTaskCode,
356 const char * const pcName, /*lint !e971 Unqualified char types are allowed for strings and single characters only. */
357 const configSTACK_DEPTH_TYPE usStackDepth,
358 void * const pvParameters,
359 UBaseType_t uxPriority,
360 TaskHandle_t * const pxCreatedTask ) PRIVILEGED_FUNCTION;
366 * TaskHandle_t xTaskCreateStatic( TaskFunction_t pxTaskCode,
367 * const char *pcName,
368 * uint32_t ulStackDepth,
369 * void *pvParameters,
370 * UBaseType_t uxPriority,
371 * StackType_t *puxStackBuffer,
372 * StaticTask_t *pxTaskBuffer );
375 * Create a new task and add it to the list of tasks that are ready to run.
377 * Internally, within the FreeRTOS implementation, tasks use two blocks of
378 * memory. The first block is used to hold the task's data structures. The
379 * second block is used by the task as its stack. If a task is created using
380 * xTaskCreate() then both blocks of memory are automatically dynamically
381 * allocated inside the xTaskCreate() function. (see
382 * https://www.FreeRTOS.org/a00111.html). If a task is created using
383 * xTaskCreateStatic() then the application writer must provide the required
384 * memory. xTaskCreateStatic() therefore allows a task to be created without
385 * using any dynamic memory allocation.
387 * @param pxTaskCode Pointer to the task entry function. Tasks
388 * must be implemented to never return (i.e. continuous loop).
390 * @param pcName A descriptive name for the task. This is mainly used to
391 * facilitate debugging. The maximum length of the string is defined by
392 * configMAX_TASK_NAME_LEN in FreeRTOSConfig.h.
394 * @param ulStackDepth The size of the task stack specified as the number of
395 * variables the stack can hold - not the number of bytes. For example, if
396 * the stack is 32-bits wide and ulStackDepth is defined as 100 then 400 bytes
397 * will be allocated for stack storage.
399 * @param pvParameters Pointer that will be used as the parameter for the task
402 * @param uxPriority The priority at which the task will run.
404 * @param puxStackBuffer Must point to a StackType_t array that has at least
405 * ulStackDepth indexes - the array will then be used as the task's stack,
406 * removing the need for the stack to be allocated dynamically.
408 * @param pxTaskBuffer Must point to a variable of type StaticTask_t, which will
409 * then be used to hold the task's data structures, removing the need for the
410 * memory to be allocated dynamically.
412 * @return If neither puxStackBuffer nor pxTaskBuffer are NULL, then the task
413 * will be created and a handle to the created task is returned. If either
414 * puxStackBuffer or pxTaskBuffer are NULL then the task will not be created and
420 * // Dimensions of the buffer that the task being created will use as its stack.
421 * // NOTE: This is the number of words the stack will hold, not the number of
422 * // bytes. For example, if each stack item is 32-bits, and this is set to 100,
423 * // then 400 bytes (100 * 32-bits) will be allocated.
424 #define STACK_SIZE 200
426 * // Structure that will hold the TCB of the task being created.
427 * StaticTask_t xTaskBuffer;
429 * // Buffer that the task being created will use as its stack. Note this is
430 * // an array of StackType_t variables. The size of StackType_t is dependent on
432 * StackType_t xStack[ STACK_SIZE ];
434 * // Function that implements the task being created.
435 * void vTaskCode( void * pvParameters )
437 * // The parameter value is expected to be 1 as 1 is passed in the
438 * // pvParameters value in the call to xTaskCreateStatic().
439 * configASSERT( ( uint32_t ) pvParameters == 1UL );
443 * // Task code goes here.
447 * // Function that creates a task.
448 * void vOtherFunction( void )
450 * TaskHandle_t xHandle = NULL;
452 * // Create the task without using any dynamic memory allocation.
453 * xHandle = xTaskCreateStatic(
454 * vTaskCode, // Function that implements the task.
455 * "NAME", // Text name for the task.
456 * STACK_SIZE, // Stack size in words, not bytes.
457 * ( void * ) 1, // Parameter passed into the task.
458 * tskIDLE_PRIORITY,// Priority at which the task is created.
459 * xStack, // Array to use as the task's stack.
460 * &xTaskBuffer ); // Variable to hold the task's data structure.
462 * // puxStackBuffer and pxTaskBuffer were not NULL, so the task will have
463 * // been created, and xHandle will be the task's handle. Use the handle
464 * // to suspend the task.
465 * vTaskSuspend( xHandle );
468 * \defgroup xTaskCreateStatic xTaskCreateStatic
471 #if ( configSUPPORT_STATIC_ALLOCATION == 1 )
472 TaskHandle_t xTaskCreateStatic( TaskFunction_t pxTaskCode,
473 const char * const pcName, /*lint !e971 Unqualified char types are allowed for strings and single characters only. */
474 const uint32_t ulStackDepth,
475 void * const pvParameters,
476 UBaseType_t uxPriority,
477 StackType_t * const puxStackBuffer,
478 StaticTask_t * const pxTaskBuffer ) PRIVILEGED_FUNCTION;
479 #endif /* configSUPPORT_STATIC_ALLOCATION */
484 * BaseType_t xTaskCreateRestricted( TaskParameters_t *pxTaskDefinition, TaskHandle_t *pxCreatedTask );
487 * Only available when configSUPPORT_DYNAMIC_ALLOCATION is set to 1.
489 * xTaskCreateRestricted() should only be used in systems that include an MPU
492 * Create a new task and add it to the list of tasks that are ready to run.
493 * The function parameters define the memory regions and associated access
494 * permissions allocated to the task.
496 * See xTaskCreateRestrictedStatic() for a version that does not use any
497 * dynamic memory allocation.
499 * @param pxTaskDefinition Pointer to a structure that contains a member
500 * for each of the normal xTaskCreate() parameters (see the xTaskCreate() API
501 * documentation) plus an optional stack buffer and the memory region
504 * @param pxCreatedTask Used to pass back a handle by which the created task
507 * @return pdPASS if the task was successfully created and added to a ready
508 * list, otherwise an error code defined in the file projdefs.h
512 * // Create an TaskParameters_t structure that defines the task to be created.
513 * static const TaskParameters_t xCheckTaskParameters =
515 * vATask, // pvTaskCode - the function that implements the task.
516 * "ATask", // pcName - just a text name for the task to assist debugging.
517 * 100, // usStackDepth - the stack size DEFINED IN WORDS.
518 * NULL, // pvParameters - passed into the task function as the function parameters.
519 * ( 1UL | portPRIVILEGE_BIT ),// uxPriority - task priority, set the portPRIVILEGE_BIT if the task should run in a privileged state.
520 * cStackBuffer,// puxStackBuffer - the buffer to be used as the task stack.
522 * // xRegions - Allocate up to three separate memory regions for access by
523 * // the task, with appropriate access permissions. Different processors have
524 * // different memory alignment requirements - refer to the FreeRTOS documentation
525 * // for full information.
527 * // Base address Length Parameters
528 * { cReadWriteArray, 32, portMPU_REGION_READ_WRITE },
529 * { cReadOnlyArray, 32, portMPU_REGION_READ_ONLY },
530 * { cPrivilegedOnlyAccessArray, 128, portMPU_REGION_PRIVILEGED_READ_WRITE }
536 * TaskHandle_t xHandle;
538 * // Create a task from the const structure defined above. The task handle
539 * // is requested (the second parameter is not NULL) but in this case just for
540 * // demonstration purposes as its not actually used.
541 * xTaskCreateRestricted( &xRegTest1Parameters, &xHandle );
543 * // Start the scheduler.
544 * vTaskStartScheduler();
546 * // Will only get here if there was insufficient memory to create the idle
547 * // and/or timer task.
551 * \defgroup xTaskCreateRestricted xTaskCreateRestricted
554 #if ( portUSING_MPU_WRAPPERS == 1 )
555 BaseType_t xTaskCreateRestricted( const TaskParameters_t * const pxTaskDefinition,
556 TaskHandle_t * pxCreatedTask ) PRIVILEGED_FUNCTION;
562 * BaseType_t xTaskCreateRestrictedStatic( TaskParameters_t *pxTaskDefinition, TaskHandle_t *pxCreatedTask );
565 * Only available when configSUPPORT_STATIC_ALLOCATION is set to 1.
567 * xTaskCreateRestrictedStatic() should only be used in systems that include an
568 * MPU implementation.
570 * Internally, within the FreeRTOS implementation, tasks use two blocks of
571 * memory. The first block is used to hold the task's data structures. The
572 * second block is used by the task as its stack. If a task is created using
573 * xTaskCreateRestricted() then the stack is provided by the application writer,
574 * and the memory used to hold the task's data structure is automatically
575 * dynamically allocated inside the xTaskCreateRestricted() function. If a task
576 * is created using xTaskCreateRestrictedStatic() then the application writer
577 * must provide the memory used to hold the task's data structures too.
578 * xTaskCreateRestrictedStatic() therefore allows a memory protected task to be
579 * created without using any dynamic memory allocation.
581 * @param pxTaskDefinition Pointer to a structure that contains a member
582 * for each of the normal xTaskCreate() parameters (see the xTaskCreate() API
583 * documentation) plus an optional stack buffer and the memory region
584 * definitions. If configSUPPORT_STATIC_ALLOCATION is set to 1 the structure
585 * contains an additional member, which is used to point to a variable of type
586 * StaticTask_t - which is then used to hold the task's data structure.
588 * @param pxCreatedTask Used to pass back a handle by which the created task
591 * @return pdPASS if the task was successfully created and added to a ready
592 * list, otherwise an error code defined in the file projdefs.h
596 * // Create an TaskParameters_t structure that defines the task to be created.
597 * // The StaticTask_t variable is only included in the structure when
598 * // configSUPPORT_STATIC_ALLOCATION is set to 1. The PRIVILEGED_DATA macro can
599 * // be used to force the variable into the RTOS kernel's privileged data area.
600 * static PRIVILEGED_DATA StaticTask_t xTaskBuffer;
601 * static const TaskParameters_t xCheckTaskParameters =
603 * vATask, // pvTaskCode - the function that implements the task.
604 * "ATask", // pcName - just a text name for the task to assist debugging.
605 * 100, // usStackDepth - the stack size DEFINED IN WORDS.
606 * NULL, // pvParameters - passed into the task function as the function parameters.
607 * ( 1UL | portPRIVILEGE_BIT ),// uxPriority - task priority, set the portPRIVILEGE_BIT if the task should run in a privileged state.
608 * cStackBuffer,// puxStackBuffer - the buffer to be used as the task stack.
610 * // xRegions - Allocate up to three separate memory regions for access by
611 * // the task, with appropriate access permissions. Different processors have
612 * // different memory alignment requirements - refer to the FreeRTOS documentation
613 * // for full information.
615 * // Base address Length Parameters
616 * { cReadWriteArray, 32, portMPU_REGION_READ_WRITE },
617 * { cReadOnlyArray, 32, portMPU_REGION_READ_ONLY },
618 * { cPrivilegedOnlyAccessArray, 128, portMPU_REGION_PRIVILEGED_READ_WRITE }
621 * &xTaskBuffer; // Holds the task's data structure.
626 * TaskHandle_t xHandle;
628 * // Create a task from the const structure defined above. The task handle
629 * // is requested (the second parameter is not NULL) but in this case just for
630 * // demonstration purposes as its not actually used.
631 * xTaskCreateRestrictedStatic( &xRegTest1Parameters, &xHandle );
633 * // Start the scheduler.
634 * vTaskStartScheduler();
636 * // Will only get here if there was insufficient memory to create the idle
637 * // and/or timer task.
641 * \defgroup xTaskCreateRestrictedStatic xTaskCreateRestrictedStatic
644 #if ( ( portUSING_MPU_WRAPPERS == 1 ) && ( configSUPPORT_STATIC_ALLOCATION == 1 ) )
645 BaseType_t xTaskCreateRestrictedStatic( const TaskParameters_t * const pxTaskDefinition,
646 TaskHandle_t * pxCreatedTask ) PRIVILEGED_FUNCTION;
652 * void vTaskAllocateMPURegions( TaskHandle_t xTask, const MemoryRegion_t * const pxRegions );
655 * Memory regions are assigned to a restricted task when the task is created by
656 * a call to xTaskCreateRestricted(). These regions can be redefined using
657 * vTaskAllocateMPURegions().
659 * @param xTask The handle of the task being updated.
661 * @param[in] pxRegions A pointer to a MemoryRegion_t structure that contains the
662 * new memory region definitions.
666 * // Define an array of MemoryRegion_t structures that configures an MPU region
667 * // allowing read/write access for 1024 bytes starting at the beginning of the
668 * // ucOneKByte array. The other two of the maximum 3 definable regions are
669 * // unused so set to zero.
670 * static const MemoryRegion_t xAltRegions[ portNUM_CONFIGURABLE_REGIONS ] =
672 * // Base address Length Parameters
673 * { ucOneKByte, 1024, portMPU_REGION_READ_WRITE },
678 * void vATask( void *pvParameters )
680 * // This task was created such that it has access to certain regions of
681 * // memory as defined by the MPU configuration. At some point it is
682 * // desired that these MPU regions are replaced with that defined in the
683 * // xAltRegions const struct above. Use a call to vTaskAllocateMPURegions()
684 * // for this purpose. NULL is used as the task handle to indicate that this
685 * // function should modify the MPU regions of the calling task.
686 * vTaskAllocateMPURegions( NULL, xAltRegions );
688 * // Now the task can continue its function, but from this point on can only
689 * // access its stack and the ucOneKByte array (unless any other statically
690 * // defined or shared regions have been declared elsewhere).
693 * \defgroup vTaskAllocateMPURegions vTaskAllocateMPURegions
696 void vTaskAllocateMPURegions( TaskHandle_t xTask,
697 const MemoryRegion_t * const pxRegions ) PRIVILEGED_FUNCTION;
702 * void vTaskDelete( TaskHandle_t xTaskToDelete );
705 * INCLUDE_vTaskDelete must be defined as 1 for this function to be available.
706 * See the configuration section for more information.
708 * Remove a task from the RTOS real time kernel's management. The task being
709 * deleted will be removed from all ready, blocked, suspended and event lists.
711 * NOTE: The idle task is responsible for freeing the kernel allocated
712 * memory from tasks that have been deleted. It is therefore important that
713 * the idle task is not starved of microcontroller processing time if your
714 * application makes any calls to vTaskDelete (). Memory allocated by the
715 * task code is not automatically freed, and should be freed before the task
718 * See the demo application file death.c for sample code that utilises
721 * @param xTaskToDelete The handle of the task to be deleted. Passing NULL will
722 * cause the calling task to be deleted.
726 * void vOtherFunction( void )
728 * TaskHandle_t xHandle;
730 * // Create the task, storing the handle.
731 * xTaskCreate( vTaskCode, "NAME", STACK_SIZE, NULL, tskIDLE_PRIORITY, &xHandle );
733 * // Use the handle to delete the task.
734 * vTaskDelete( xHandle );
737 * \defgroup vTaskDelete vTaskDelete
740 void vTaskDelete( TaskHandle_t xTaskToDelete ) PRIVILEGED_FUNCTION;
742 /*-----------------------------------------------------------
744 *----------------------------------------------------------*/
749 * void vTaskDelay( const TickType_t xTicksToDelay );
752 * Delay a task for a given number of ticks. The actual time that the
753 * task remains blocked depends on the tick rate. The constant
754 * portTICK_PERIOD_MS can be used to calculate real time from the tick
755 * rate - with the resolution of one tick period.
757 * INCLUDE_vTaskDelay must be defined as 1 for this function to be available.
758 * See the configuration section for more information.
761 * vTaskDelay() specifies a time at which the task wishes to unblock relative to
762 * the time at which vTaskDelay() is called. For example, specifying a block
763 * period of 100 ticks will cause the task to unblock 100 ticks after
764 * vTaskDelay() is called. vTaskDelay() does not therefore provide a good method
765 * of controlling the frequency of a periodic task as the path taken through the
766 * code, as well as other task and interrupt activity, will affect the frequency
767 * at which vTaskDelay() gets called and therefore the time at which the task
768 * next executes. See xTaskDelayUntil() for an alternative API function designed
769 * to facilitate fixed frequency execution. It does this by specifying an
770 * absolute time (rather than a relative time) at which the calling task should
773 * @param xTicksToDelay The amount of time, in tick periods, that
774 * the calling task should block.
778 * void vTaskFunction( void * pvParameters )
780 * // Block for 500ms.
781 * const TickType_t xDelay = 500 / portTICK_PERIOD_MS;
785 * // Simply toggle the LED every 500ms, blocking between each toggle.
787 * vTaskDelay( xDelay );
791 * \defgroup vTaskDelay vTaskDelay
794 void vTaskDelay( const TickType_t xTicksToDelay ) PRIVILEGED_FUNCTION;
799 * BaseType_t xTaskDelayUntil( TickType_t *pxPreviousWakeTime, const TickType_t xTimeIncrement );
802 * INCLUDE_xTaskDelayUntil must be defined as 1 for this function to be available.
803 * See the configuration section for more information.
805 * Delay a task until a specified time. This function can be used by periodic
806 * tasks to ensure a constant execution frequency.
808 * This function differs from vTaskDelay () in one important aspect: vTaskDelay () will
809 * cause a task to block for the specified number of ticks from the time vTaskDelay () is
810 * called. It is therefore difficult to use vTaskDelay () by itself to generate a fixed
811 * execution frequency as the time between a task starting to execute and that task
812 * calling vTaskDelay () may not be fixed [the task may take a different path though the
813 * code between calls, or may get interrupted or preempted a different number of times
814 * each time it executes].
816 * Whereas vTaskDelay () specifies a wake time relative to the time at which the function
817 * is called, xTaskDelayUntil () specifies the absolute (exact) time at which it wishes to
820 * The macro pdMS_TO_TICKS() can be used to calculate the number of ticks from a
821 * time specified in milliseconds with a resolution of one tick period.
823 * @param pxPreviousWakeTime Pointer to a variable that holds the time at which the
824 * task was last unblocked. The variable must be initialised with the current time
825 * prior to its first use (see the example below). Following this the variable is
826 * automatically updated within xTaskDelayUntil ().
828 * @param xTimeIncrement The cycle time period. The task will be unblocked at
829 * time *pxPreviousWakeTime + xTimeIncrement. Calling xTaskDelayUntil with the
830 * same xTimeIncrement parameter value will cause the task to execute with
831 * a fixed interface period.
833 * @return Value which can be used to check whether the task was actually delayed.
834 * Will be pdTRUE if the task way delayed and pdFALSE otherwise. A task will not
835 * be delayed if the next expected wake time is in the past.
839 * // Perform an action every 10 ticks.
840 * void vTaskFunction( void * pvParameters )
842 * TickType_t xLastWakeTime;
843 * const TickType_t xFrequency = 10;
844 * BaseType_t xWasDelayed;
846 * // Initialise the xLastWakeTime variable with the current time.
847 * xLastWakeTime = xTaskGetTickCount ();
850 * // Wait for the next cycle.
851 * xWasDelayed = xTaskDelayUntil( &xLastWakeTime, xFrequency );
853 * // Perform action here. xWasDelayed value can be used to determine
854 * // whether a deadline was missed if the code here took too long.
858 * \defgroup xTaskDelayUntil xTaskDelayUntil
861 BaseType_t xTaskDelayUntil( TickType_t * const pxPreviousWakeTime,
862 const TickType_t xTimeIncrement ) PRIVILEGED_FUNCTION;
865 * vTaskDelayUntil() is the older version of xTaskDelayUntil() and does not
868 #define vTaskDelayUntil( pxPreviousWakeTime, xTimeIncrement ) \
870 ( void ) xTaskDelayUntil( ( pxPreviousWakeTime ), ( xTimeIncrement ) ); \
877 * BaseType_t xTaskAbortDelay( TaskHandle_t xTask );
880 * INCLUDE_xTaskAbortDelay must be defined as 1 in FreeRTOSConfig.h for this
881 * function to be available.
883 * A task will enter the Blocked state when it is waiting for an event. The
884 * event it is waiting for can be a temporal event (waiting for a time), such
885 * as when vTaskDelay() is called, or an event on an object, such as when
886 * xQueueReceive() or ulTaskNotifyTake() is called. If the handle of a task
887 * that is in the Blocked state is used in a call to xTaskAbortDelay() then the
888 * task will leave the Blocked state, and return from whichever function call
889 * placed the task into the Blocked state.
891 * There is no 'FromISR' version of this function as an interrupt would need to
892 * know which object a task was blocked on in order to know which actions to
893 * take. For example, if the task was blocked on a queue the interrupt handler
894 * would then need to know if the queue was locked.
896 * @param xTask The handle of the task to remove from the Blocked state.
898 * @return If the task referenced by xTask was not in the Blocked state then
899 * pdFAIL is returned. Otherwise pdPASS is returned.
901 * \defgroup xTaskAbortDelay xTaskAbortDelay
904 BaseType_t xTaskAbortDelay( TaskHandle_t xTask ) PRIVILEGED_FUNCTION;
909 * UBaseType_t uxTaskPriorityGet( const TaskHandle_t xTask );
912 * INCLUDE_uxTaskPriorityGet must be defined as 1 for this function to be available.
913 * See the configuration section for more information.
915 * Obtain the priority of any task.
917 * @param xTask Handle of the task to be queried. Passing a NULL
918 * handle results in the priority of the calling task being returned.
920 * @return The priority of xTask.
924 * void vAFunction( void )
926 * TaskHandle_t xHandle;
928 * // Create a task, storing the handle.
929 * xTaskCreate( vTaskCode, "NAME", STACK_SIZE, NULL, tskIDLE_PRIORITY, &xHandle );
933 * // Use the handle to obtain the priority of the created task.
934 * // It was created with tskIDLE_PRIORITY, but may have changed
936 * if( uxTaskPriorityGet( xHandle ) != tskIDLE_PRIORITY )
938 * // The task has changed it's priority.
943 * // Is our priority higher than the created task?
944 * if( uxTaskPriorityGet( xHandle ) < uxTaskPriorityGet( NULL ) )
946 * // Our priority (obtained using NULL handle) is higher.
950 * \defgroup uxTaskPriorityGet uxTaskPriorityGet
953 UBaseType_t uxTaskPriorityGet( const TaskHandle_t xTask ) PRIVILEGED_FUNCTION;
958 * UBaseType_t uxTaskPriorityGetFromISR( const TaskHandle_t xTask );
961 * A version of uxTaskPriorityGet() that can be used from an ISR.
963 UBaseType_t uxTaskPriorityGetFromISR( const TaskHandle_t xTask ) PRIVILEGED_FUNCTION;
968 * eTaskState eTaskGetState( TaskHandle_t xTask );
971 * INCLUDE_eTaskGetState must be defined as 1 for this function to be available.
972 * See the configuration section for more information.
974 * Obtain the state of any task. States are encoded by the eTaskState
977 * @param xTask Handle of the task to be queried.
979 * @return The state of xTask at the time the function was called. Note the
980 * state of the task might change between the function being called, and the
981 * functions return value being tested by the calling task.
983 eTaskState eTaskGetState( TaskHandle_t xTask ) PRIVILEGED_FUNCTION;
988 * void vTaskGetInfo( TaskHandle_t xTask, TaskStatus_t *pxTaskStatus, BaseType_t xGetFreeStackSpace, eTaskState eState );
991 * configUSE_TRACE_FACILITY must be defined as 1 for this function to be
992 * available. See the configuration section for more information.
994 * Populates a TaskStatus_t structure with information about a task.
996 * @param xTask Handle of the task being queried. If xTask is NULL then
997 * information will be returned about the calling task.
999 * @param pxTaskStatus A pointer to the TaskStatus_t structure that will be
1000 * filled with information about the task referenced by the handle passed using
1001 * the xTask parameter.
1003 * @param xGetFreeStackSpace The TaskStatus_t structure contains a member to report
1004 * the stack high water mark of the task being queried. Calculating the stack
1005 * high water mark takes a relatively long time, and can make the system
1006 * temporarily unresponsive - so the xGetFreeStackSpace parameter is provided to
1007 * allow the high water mark checking to be skipped. The high watermark value
1008 * will only be written to the TaskStatus_t structure if xGetFreeStackSpace is
1009 * not set to pdFALSE;
1011 * @param eState The TaskStatus_t structure contains a member to report the
1012 * state of the task being queried. Obtaining the task state is not as fast as
1013 * a simple assignment - so the eState parameter is provided to allow the state
1014 * information to be omitted from the TaskStatus_t structure. To obtain state
1015 * information then set eState to eInvalid - otherwise the value passed in
1016 * eState will be reported as the task state in the TaskStatus_t structure.
1020 * void vAFunction( void )
1022 * TaskHandle_t xHandle;
1023 * TaskStatus_t xTaskDetails;
1025 * // Obtain the handle of a task from its name.
1026 * xHandle = xTaskGetHandle( "Task_Name" );
1028 * // Check the handle is not NULL.
1029 * configASSERT( xHandle );
1031 * // Use the handle to obtain further information about the task.
1032 * vTaskGetInfo( xHandle,
1034 * pdTRUE, // Include the high water mark in xTaskDetails.
1035 * eInvalid ); // Include the task state in xTaskDetails.
1038 * \defgroup vTaskGetInfo vTaskGetInfo
1041 void vTaskGetInfo( TaskHandle_t xTask,
1042 TaskStatus_t * pxTaskStatus,
1043 BaseType_t xGetFreeStackSpace,
1044 eTaskState eState ) PRIVILEGED_FUNCTION;
1049 * void vTaskPrioritySet( TaskHandle_t xTask, UBaseType_t uxNewPriority );
1052 * INCLUDE_vTaskPrioritySet must be defined as 1 for this function to be available.
1053 * See the configuration section for more information.
1055 * Set the priority of any task.
1057 * A context switch will occur before the function returns if the priority
1058 * being set is higher than the currently executing task.
1060 * @param xTask Handle to the task for which the priority is being set.
1061 * Passing a NULL handle results in the priority of the calling task being set.
1063 * @param uxNewPriority The priority to which the task will be set.
1067 * void vAFunction( void )
1069 * TaskHandle_t xHandle;
1071 * // Create a task, storing the handle.
1072 * xTaskCreate( vTaskCode, "NAME", STACK_SIZE, NULL, tskIDLE_PRIORITY, &xHandle );
1076 * // Use the handle to raise the priority of the created task.
1077 * vTaskPrioritySet( xHandle, tskIDLE_PRIORITY + 1 );
1081 * // Use a NULL handle to raise our priority to the same value.
1082 * vTaskPrioritySet( NULL, tskIDLE_PRIORITY + 1 );
1085 * \defgroup vTaskPrioritySet vTaskPrioritySet
1088 void vTaskPrioritySet( TaskHandle_t xTask,
1089 UBaseType_t uxNewPriority ) PRIVILEGED_FUNCTION;
1094 * void vTaskSuspend( TaskHandle_t xTaskToSuspend );
1097 * INCLUDE_vTaskSuspend must be defined as 1 for this function to be available.
1098 * See the configuration section for more information.
1100 * Suspend any task. When suspended a task will never get any microcontroller
1101 * processing time, no matter what its priority.
1103 * Calls to vTaskSuspend are not accumulative -
1104 * i.e. calling vTaskSuspend () twice on the same task still only requires one
1105 * call to vTaskResume () to ready the suspended task.
1107 * @param xTaskToSuspend Handle to the task being suspended. Passing a NULL
1108 * handle will cause the calling task to be suspended.
1112 * void vAFunction( void )
1114 * TaskHandle_t xHandle;
1116 * // Create a task, storing the handle.
1117 * xTaskCreate( vTaskCode, "NAME", STACK_SIZE, NULL, tskIDLE_PRIORITY, &xHandle );
1121 * // Use the handle to suspend the created task.
1122 * vTaskSuspend( xHandle );
1126 * // The created task will not run during this period, unless
1127 * // another task calls vTaskResume( xHandle ).
1132 * // Suspend ourselves.
1133 * vTaskSuspend( NULL );
1135 * // We cannot get here unless another task calls vTaskResume
1136 * // with our handle as the parameter.
1139 * \defgroup vTaskSuspend vTaskSuspend
1142 void vTaskSuspend( TaskHandle_t xTaskToSuspend ) PRIVILEGED_FUNCTION;
1147 * void vTaskResume( TaskHandle_t xTaskToResume );
1150 * INCLUDE_vTaskSuspend must be defined as 1 for this function to be available.
1151 * See the configuration section for more information.
1153 * Resumes a suspended task.
1155 * A task that has been suspended by one or more calls to vTaskSuspend ()
1156 * will be made available for running again by a single call to
1159 * @param xTaskToResume Handle to the task being readied.
1163 * void vAFunction( void )
1165 * TaskHandle_t xHandle;
1167 * // Create a task, storing the handle.
1168 * xTaskCreate( vTaskCode, "NAME", STACK_SIZE, NULL, tskIDLE_PRIORITY, &xHandle );
1172 * // Use the handle to suspend the created task.
1173 * vTaskSuspend( xHandle );
1177 * // The created task will not run during this period, unless
1178 * // another task calls vTaskResume( xHandle ).
1183 * // Resume the suspended task ourselves.
1184 * vTaskResume( xHandle );
1186 * // The created task will once again get microcontroller processing
1187 * // time in accordance with its priority within the system.
1190 * \defgroup vTaskResume vTaskResume
1193 void vTaskResume( TaskHandle_t xTaskToResume ) PRIVILEGED_FUNCTION;
1198 * void xTaskResumeFromISR( TaskHandle_t xTaskToResume );
1201 * INCLUDE_xTaskResumeFromISR must be defined as 1 for this function to be
1202 * available. See the configuration section for more information.
1204 * An implementation of vTaskResume() that can be called from within an ISR.
1206 * A task that has been suspended by one or more calls to vTaskSuspend ()
1207 * will be made available for running again by a single call to
1208 * xTaskResumeFromISR ().
1210 * xTaskResumeFromISR() should not be used to synchronise a task with an
1211 * interrupt if there is a chance that the interrupt could arrive prior to the
1212 * task being suspended - as this can lead to interrupts being missed. Use of a
1213 * semaphore as a synchronisation mechanism would avoid this eventuality.
1215 * @param xTaskToResume Handle to the task being readied.
1217 * @return pdTRUE if resuming the task should result in a context switch,
1218 * otherwise pdFALSE. This is used by the ISR to determine if a context switch
1219 * may be required following the ISR.
1221 * \defgroup vTaskResumeFromISR vTaskResumeFromISR
1224 BaseType_t xTaskResumeFromISR( TaskHandle_t xTaskToResume ) PRIVILEGED_FUNCTION;
1226 /*-----------------------------------------------------------
1228 *----------------------------------------------------------*/
1233 * void vTaskStartScheduler( void );
1236 * Starts the real time kernel tick processing. After calling the kernel
1237 * has control over which tasks are executed and when.
1239 * See the demo application file main.c for an example of creating
1240 * tasks and starting the kernel.
1244 * void vAFunction( void )
1246 * // Create at least one task before starting the kernel.
1247 * xTaskCreate( vTaskCode, "NAME", STACK_SIZE, NULL, tskIDLE_PRIORITY, NULL );
1249 * // Start the real time kernel with preemption.
1250 * vTaskStartScheduler ();
1252 * // Will not get here unless a task calls vTaskEndScheduler ()
1256 * \defgroup vTaskStartScheduler vTaskStartScheduler
1257 * \ingroup SchedulerControl
1259 void vTaskStartScheduler( void ) PRIVILEGED_FUNCTION;
1264 * void vTaskEndScheduler( void );
1267 * NOTE: At the time of writing only the x86 real mode port, which runs on a PC
1268 * in place of DOS, implements this function.
1270 * Stops the real time kernel tick. All created tasks will be automatically
1271 * deleted and multitasking (either preemptive or cooperative) will
1272 * stop. Execution then resumes from the point where vTaskStartScheduler ()
1273 * was called, as if vTaskStartScheduler () had just returned.
1275 * See the demo application file main. c in the demo/PC directory for an
1276 * example that uses vTaskEndScheduler ().
1278 * vTaskEndScheduler () requires an exit function to be defined within the
1279 * portable layer (see vPortEndScheduler () in port. c for the PC port). This
1280 * performs hardware specific operations such as stopping the kernel tick.
1282 * vTaskEndScheduler () will cause all of the resources allocated by the
1283 * kernel to be freed - but will not free resources allocated by application
1288 * void vTaskCode( void * pvParameters )
1292 * // Task code goes here.
1294 * // At some point we want to end the real time kernel processing
1296 * vTaskEndScheduler ();
1300 * void vAFunction( void )
1302 * // Create at least one task before starting the kernel.
1303 * xTaskCreate( vTaskCode, "NAME", STACK_SIZE, NULL, tskIDLE_PRIORITY, NULL );
1305 * // Start the real time kernel with preemption.
1306 * vTaskStartScheduler ();
1308 * // Will only get here when the vTaskCode () task has called
1309 * // vTaskEndScheduler (). When we get here we are back to single task
1314 * \defgroup vTaskEndScheduler vTaskEndScheduler
1315 * \ingroup SchedulerControl
1317 void vTaskEndScheduler( void ) PRIVILEGED_FUNCTION;
1322 * void vTaskSuspendAll( void );
1325 * Suspends the scheduler without disabling interrupts. Context switches will
1326 * not occur while the scheduler is suspended.
1328 * After calling vTaskSuspendAll () the calling task will continue to execute
1329 * without risk of being swapped out until a call to xTaskResumeAll () has been
1332 * API functions that have the potential to cause a context switch (for example,
1333 * xTaskDelayUntil(), xQueueSend(), etc.) must not be called while the scheduler
1338 * void vTask1( void * pvParameters )
1342 * // Task code goes here.
1346 * // At some point the task wants to perform a long operation during
1347 * // which it does not want to get swapped out. It cannot use
1348 * // taskENTER_CRITICAL ()/taskEXIT_CRITICAL () as the length of the
1349 * // operation may cause interrupts to be missed - including the
1352 * // Prevent the real time kernel swapping out the task.
1353 * vTaskSuspendAll ();
1355 * // Perform the operation here. There is no need to use critical
1356 * // sections as we have all the microcontroller processing time.
1357 * // During this time interrupts will still operate and the kernel
1358 * // tick count will be maintained.
1362 * // The operation is complete. Restart the kernel.
1363 * xTaskResumeAll ();
1367 * \defgroup vTaskSuspendAll vTaskSuspendAll
1368 * \ingroup SchedulerControl
1370 void vTaskSuspendAll( void ) PRIVILEGED_FUNCTION;
1375 * BaseType_t xTaskResumeAll( void );
1378 * Resumes scheduler activity after it was suspended by a call to
1379 * vTaskSuspendAll().
1381 * xTaskResumeAll() only resumes the scheduler. It does not unsuspend tasks
1382 * that were previously suspended by a call to vTaskSuspend().
1384 * @return If resuming the scheduler caused a context switch then pdTRUE is
1385 * returned, otherwise pdFALSE is returned.
1389 * void vTask1( void * pvParameters )
1393 * // Task code goes here.
1397 * // At some point the task wants to perform a long operation during
1398 * // which it does not want to get swapped out. It cannot use
1399 * // taskENTER_CRITICAL ()/taskEXIT_CRITICAL () as the length of the
1400 * // operation may cause interrupts to be missed - including the
1403 * // Prevent the real time kernel swapping out the task.
1404 * vTaskSuspendAll ();
1406 * // Perform the operation here. There is no need to use critical
1407 * // sections as we have all the microcontroller processing time.
1408 * // During this time interrupts will still operate and the real
1409 * // time kernel tick count will be maintained.
1413 * // The operation is complete. Restart the kernel. We want to force
1414 * // a context switch - but there is no point if resuming the scheduler
1415 * // caused a context switch already.
1416 * if( !xTaskResumeAll () )
1423 * \defgroup xTaskResumeAll xTaskResumeAll
1424 * \ingroup SchedulerControl
1426 BaseType_t xTaskResumeAll( void ) PRIVILEGED_FUNCTION;
1428 /*-----------------------------------------------------------
1430 *----------------------------------------------------------*/
1435 * TickType_t xTaskGetTickCount( void );
1438 * @return The count of ticks since vTaskStartScheduler was called.
1440 * \defgroup xTaskGetTickCount xTaskGetTickCount
1441 * \ingroup TaskUtils
1443 TickType_t xTaskGetTickCount( void ) PRIVILEGED_FUNCTION;
1448 * TickType_t xTaskGetTickCountFromISR( void );
1451 * @return The count of ticks since vTaskStartScheduler was called.
1453 * This is a version of xTaskGetTickCount() that is safe to be called from an
1454 * ISR - provided that TickType_t is the natural word size of the
1455 * microcontroller being used or interrupt nesting is either not supported or
1458 * \defgroup xTaskGetTickCountFromISR xTaskGetTickCountFromISR
1459 * \ingroup TaskUtils
1461 TickType_t xTaskGetTickCountFromISR( void ) PRIVILEGED_FUNCTION;
1466 * uint16_t uxTaskGetNumberOfTasks( void );
1469 * @return The number of tasks that the real time kernel is currently managing.
1470 * This includes all ready, blocked and suspended tasks. A task that
1471 * has been deleted but not yet freed by the idle task will also be
1472 * included in the count.
1474 * \defgroup uxTaskGetNumberOfTasks uxTaskGetNumberOfTasks
1475 * \ingroup TaskUtils
1477 UBaseType_t uxTaskGetNumberOfTasks( void ) PRIVILEGED_FUNCTION;
1482 * char *pcTaskGetName( TaskHandle_t xTaskToQuery );
1485 * @return The text (human readable) name of the task referenced by the handle
1486 * xTaskToQuery. A task can query its own name by either passing in its own
1487 * handle, or by setting xTaskToQuery to NULL.
1489 * \defgroup pcTaskGetName pcTaskGetName
1490 * \ingroup TaskUtils
1492 char * pcTaskGetName( TaskHandle_t xTaskToQuery ) PRIVILEGED_FUNCTION; /*lint !e971 Unqualified char types are allowed for strings and single characters only. */
1497 * TaskHandle_t xTaskGetHandle( const char *pcNameToQuery );
1500 * NOTE: This function takes a relatively long time to complete and should be
1503 * @return The handle of the task that has the human readable name pcNameToQuery.
1504 * NULL is returned if no matching name is found. INCLUDE_xTaskGetHandle
1505 * must be set to 1 in FreeRTOSConfig.h for pcTaskGetHandle() to be available.
1507 * \defgroup pcTaskGetHandle pcTaskGetHandle
1508 * \ingroup TaskUtils
1510 TaskHandle_t xTaskGetHandle( const char * pcNameToQuery ) PRIVILEGED_FUNCTION; /*lint !e971 Unqualified char types are allowed for strings and single characters only. */
1515 * BaseType_t xTaskGetStaticBuffers( TaskHandle_t xTask,
1516 * StackType_t ** ppuxStackBuffer,
1517 * StaticTask_t ** ppxTaskBuffer );
1520 * Retrieve pointers to a statically created task's data structure
1521 * buffer and stack buffer. These are the same buffers that are supplied
1522 * at the time of creation.
1524 * @param xTask The task for which to retrieve the buffers.
1526 * @param ppuxStackBuffer Used to return a pointer to the task's stack buffer.
1528 * @param ppxTaskBuffer Used to return a pointer to the task's data structure
1531 * @return pdTRUE if buffers were retrieved, pdFALSE otherwise.
1533 * \defgroup xTaskGetStaticBuffers xTaskGetStaticBuffers
1534 * \ingroup TaskUtils
1536 #if ( configSUPPORT_STATIC_ALLOCATION == 1 )
1537 BaseType_t xTaskGetStaticBuffers( TaskHandle_t xTask,
1538 StackType_t ** ppuxStackBuffer,
1539 StaticTask_t ** ppxTaskBuffer ) PRIVILEGED_FUNCTION;
1540 #endif /* configSUPPORT_STATIC_ALLOCATION */
1545 * UBaseType_t uxTaskGetStackHighWaterMark( TaskHandle_t xTask );
1548 * INCLUDE_uxTaskGetStackHighWaterMark must be set to 1 in FreeRTOSConfig.h for
1549 * this function to be available.
1551 * Returns the high water mark of the stack associated with xTask. That is,
1552 * the minimum free stack space there has been (in words, so on a 32 bit machine
1553 * a value of 1 means 4 bytes) since the task started. The smaller the returned
1554 * number the closer the task has come to overflowing its stack.
1556 * uxTaskGetStackHighWaterMark() and uxTaskGetStackHighWaterMark2() are the
1557 * same except for their return type. Using configSTACK_DEPTH_TYPE allows the
1558 * user to determine the return type. It gets around the problem of the value
1559 * overflowing on 8-bit types without breaking backward compatibility for
1560 * applications that expect an 8-bit return type.
1562 * @param xTask Handle of the task associated with the stack to be checked.
1563 * Set xTask to NULL to check the stack of the calling task.
1565 * @return The smallest amount of free stack space there has been (in words, so
1566 * actual spaces on the stack rather than bytes) since the task referenced by
1567 * xTask was created.
1569 UBaseType_t uxTaskGetStackHighWaterMark( TaskHandle_t xTask ) PRIVILEGED_FUNCTION;
1574 * configSTACK_DEPTH_TYPE uxTaskGetStackHighWaterMark2( TaskHandle_t xTask );
1577 * INCLUDE_uxTaskGetStackHighWaterMark2 must be set to 1 in FreeRTOSConfig.h for
1578 * this function to be available.
1580 * Returns the high water mark of the stack associated with xTask. That is,
1581 * the minimum free stack space there has been (in words, so on a 32 bit machine
1582 * a value of 1 means 4 bytes) since the task started. The smaller the returned
1583 * number the closer the task has come to overflowing its stack.
1585 * uxTaskGetStackHighWaterMark() and uxTaskGetStackHighWaterMark2() are the
1586 * same except for their return type. Using configSTACK_DEPTH_TYPE allows the
1587 * user to determine the return type. It gets around the problem of the value
1588 * overflowing on 8-bit types without breaking backward compatibility for
1589 * applications that expect an 8-bit return type.
1591 * @param xTask Handle of the task associated with the stack to be checked.
1592 * Set xTask to NULL to check the stack of the calling task.
1594 * @return The smallest amount of free stack space there has been (in words, so
1595 * actual spaces on the stack rather than bytes) since the task referenced by
1596 * xTask was created.
1598 configSTACK_DEPTH_TYPE uxTaskGetStackHighWaterMark2( TaskHandle_t xTask ) PRIVILEGED_FUNCTION;
1600 /* When using trace macros it is sometimes necessary to include task.h before
1601 * FreeRTOS.h. When this is done TaskHookFunction_t will not yet have been defined,
1602 * so the following two prototypes will cause a compilation error. This can be
1603 * fixed by simply guarding against the inclusion of these two prototypes unless
1604 * they are explicitly required by the configUSE_APPLICATION_TASK_TAG configuration
1606 #ifdef configUSE_APPLICATION_TASK_TAG
1607 #if configUSE_APPLICATION_TASK_TAG == 1
1612 * void vTaskSetApplicationTaskTag( TaskHandle_t xTask, TaskHookFunction_t pxHookFunction );
1615 * Sets pxHookFunction to be the task hook function used by the task xTask.
1616 * Passing xTask as NULL has the effect of setting the calling tasks hook
1619 void vTaskSetApplicationTaskTag( TaskHandle_t xTask,
1620 TaskHookFunction_t pxHookFunction ) PRIVILEGED_FUNCTION;
1625 * void xTaskGetApplicationTaskTag( TaskHandle_t xTask );
1628 * Returns the pxHookFunction value assigned to the task xTask. Do not
1629 * call from an interrupt service routine - call
1630 * xTaskGetApplicationTaskTagFromISR() instead.
1632 TaskHookFunction_t xTaskGetApplicationTaskTag( TaskHandle_t xTask ) PRIVILEGED_FUNCTION;
1637 * void xTaskGetApplicationTaskTagFromISR( TaskHandle_t xTask );
1640 * Returns the pxHookFunction value assigned to the task xTask. Can
1641 * be called from an interrupt service routine.
1643 TaskHookFunction_t xTaskGetApplicationTaskTagFromISR( TaskHandle_t xTask ) PRIVILEGED_FUNCTION;
1644 #endif /* configUSE_APPLICATION_TASK_TAG ==1 */
1645 #endif /* ifdef configUSE_APPLICATION_TASK_TAG */
1647 #if ( configNUM_THREAD_LOCAL_STORAGE_POINTERS > 0 )
1649 /* Each task contains an array of pointers that is dimensioned by the
1650 * configNUM_THREAD_LOCAL_STORAGE_POINTERS setting in FreeRTOSConfig.h. The
1651 * kernel does not use the pointers itself, so the application writer can use
1652 * the pointers for any purpose they wish. The following two functions are
1653 * used to set and query a pointer respectively. */
1654 void vTaskSetThreadLocalStoragePointer( TaskHandle_t xTaskToSet,
1656 void * pvValue ) PRIVILEGED_FUNCTION;
1657 void * pvTaskGetThreadLocalStoragePointer( TaskHandle_t xTaskToQuery,
1658 BaseType_t xIndex ) PRIVILEGED_FUNCTION;
1662 #if ( configCHECK_FOR_STACK_OVERFLOW > 0 )
1667 * void vApplicationStackOverflowHook( TaskHandle_t xTask, char *pcTaskName);
1670 * The application stack overflow hook is called when a stack overflow is detected for a task.
1672 * Details on stack overflow detection can be found here: https://www.FreeRTOS.org/Stacks-and-stack-overflow-checking.html
1674 * @param xTask the task that just exceeded its stack boundaries.
1675 * @param pcTaskName A character string containing the name of the offending task.
1677 void vApplicationStackOverflowHook( TaskHandle_t xTask,
1678 char * pcTaskName );
1682 #if ( configUSE_IDLE_HOOK == 1 )
1687 * void vApplicationIdleHook( void );
1690 * The application idle hook is called by the idle task.
1691 * This allows the application designer to add background functionality without
1692 * the overhead of a separate task.
1693 * NOTE: vApplicationIdleHook() MUST NOT, UNDER ANY CIRCUMSTANCES, CALL A FUNCTION THAT MIGHT BLOCK.
1695 void vApplicationIdleHook( void );
1700 #if ( configUSE_TICK_HOOK != 0 )
1705 * void vApplicationTickHook( void );
1708 * This hook function is called in the system tick handler after any OS work is completed.
1710 void vApplicationTickHook( void ); /*lint !e526 Symbol not defined as it is an application callback. */
1714 #if ( configSUPPORT_STATIC_ALLOCATION == 1 )
1719 * void vApplicationGetIdleTaskMemory( StaticTask_t ** ppxIdleTaskTCBBuffer, StackType_t ** ppxIdleTaskStackBuffer, uint32_t *pulIdleTaskStackSize )
1722 * This function is used to provide a statically allocated block of memory to FreeRTOS to hold the Idle Task TCB. This function is required when
1723 * configSUPPORT_STATIC_ALLOCATION is set. For more information see this URI: https://www.FreeRTOS.org/a00110.html#configSUPPORT_STATIC_ALLOCATION
1725 * @param ppxIdleTaskTCBBuffer A handle to a statically allocated TCB buffer
1726 * @param ppxIdleTaskStackBuffer A handle to a statically allocated Stack buffer for the idle task
1727 * @param pulIdleTaskStackSize A pointer to the number of elements that will fit in the allocated stack buffer
1729 void vApplicationGetIdleTaskMemory( StaticTask_t ** ppxIdleTaskTCBBuffer,
1730 StackType_t ** ppxIdleTaskStackBuffer,
1731 uint32_t * pulIdleTaskStackSize ); /*lint !e526 Symbol not defined as it is an application callback. */
1737 * BaseType_t xTaskCallApplicationTaskHook( TaskHandle_t xTask, void *pvParameter );
1740 * Calls the hook function associated with xTask. Passing xTask as NULL has
1741 * the effect of calling the Running tasks (the calling task) hook function.
1743 * pvParameter is passed to the hook function for the task to interpret as it
1744 * wants. The return value is the value returned by the task hook function
1745 * registered by the user.
1747 BaseType_t xTaskCallApplicationTaskHook( TaskHandle_t xTask,
1748 void * pvParameter ) PRIVILEGED_FUNCTION;
1751 * xTaskGetIdleTaskHandle() is only available if
1752 * INCLUDE_xTaskGetIdleTaskHandle is set to 1 in FreeRTOSConfig.h.
1754 * Simply returns the handle of the idle task. It is not valid to call
1755 * xTaskGetIdleTaskHandle() before the scheduler has been started.
1757 TaskHandle_t xTaskGetIdleTaskHandle( void ) PRIVILEGED_FUNCTION;
1760 * configUSE_TRACE_FACILITY must be defined as 1 in FreeRTOSConfig.h for
1761 * uxTaskGetSystemState() to be available.
1763 * uxTaskGetSystemState() populates an TaskStatus_t structure for each task in
1764 * the system. TaskStatus_t structures contain, among other things, members
1765 * for the task handle, task name, task priority, task state, and total amount
1766 * of run time consumed by the task. See the TaskStatus_t structure
1767 * definition in this file for the full member list.
1769 * NOTE: This function is intended for debugging use only as its use results in
1770 * the scheduler remaining suspended for an extended period.
1772 * @param pxTaskStatusArray A pointer to an array of TaskStatus_t structures.
1773 * The array must contain at least one TaskStatus_t structure for each task
1774 * that is under the control of the RTOS. The number of tasks under the control
1775 * of the RTOS can be determined using the uxTaskGetNumberOfTasks() API function.
1777 * @param uxArraySize The size of the array pointed to by the pxTaskStatusArray
1778 * parameter. The size is specified as the number of indexes in the array, or
1779 * the number of TaskStatus_t structures contained in the array, not by the
1780 * number of bytes in the array.
1782 * @param pulTotalRunTime If configGENERATE_RUN_TIME_STATS is set to 1 in
1783 * FreeRTOSConfig.h then *pulTotalRunTime is set by uxTaskGetSystemState() to the
1784 * total run time (as defined by the run time stats clock, see
1785 * https://www.FreeRTOS.org/rtos-run-time-stats.html) since the target booted.
1786 * pulTotalRunTime can be set to NULL to omit the total run time information.
1788 * @return The number of TaskStatus_t structures that were populated by
1789 * uxTaskGetSystemState(). This should equal the number returned by the
1790 * uxTaskGetNumberOfTasks() API function, but will be zero if the value passed
1791 * in the uxArraySize parameter was too small.
1795 * // This example demonstrates how a human readable table of run time stats
1796 * // information is generated from raw data provided by uxTaskGetSystemState().
1797 * // The human readable table is written to pcWriteBuffer
1798 * void vTaskGetRunTimeStats( char *pcWriteBuffer )
1800 * TaskStatus_t *pxTaskStatusArray;
1801 * volatile UBaseType_t uxArraySize, x;
1802 * configRUN_TIME_COUNTER_TYPE ulTotalRunTime, ulStatsAsPercentage;
1804 * // Make sure the write buffer does not contain a string.
1805 * pcWriteBuffer = 0x00;
1807 * // Take a snapshot of the number of tasks in case it changes while this
1808 * // function is executing.
1809 * uxArraySize = uxTaskGetNumberOfTasks();
1811 * // Allocate a TaskStatus_t structure for each task. An array could be
1812 * // allocated statically at compile time.
1813 * pxTaskStatusArray = pvPortMalloc( uxArraySize * sizeof( TaskStatus_t ) );
1815 * if( pxTaskStatusArray != NULL )
1817 * // Generate raw status information about each task.
1818 * uxArraySize = uxTaskGetSystemState( pxTaskStatusArray, uxArraySize, &ulTotalRunTime );
1820 * // For percentage calculations.
1821 * ulTotalRunTime /= 100UL;
1823 * // Avoid divide by zero errors.
1824 * if( ulTotalRunTime > 0 )
1826 * // For each populated position in the pxTaskStatusArray array,
1827 * // format the raw data as human readable ASCII data
1828 * for( x = 0; x < uxArraySize; x++ )
1830 * // What percentage of the total run time has the task used?
1831 * // This will always be rounded down to the nearest integer.
1832 * // ulTotalRunTimeDiv100 has already been divided by 100.
1833 * ulStatsAsPercentage = pxTaskStatusArray[ x ].ulRunTimeCounter / ulTotalRunTime;
1835 * if( ulStatsAsPercentage > 0UL )
1837 * sprintf( pcWriteBuffer, "%s\t\t%lu\t\t%lu%%\r\n", pxTaskStatusArray[ x ].pcTaskName, pxTaskStatusArray[ x ].ulRunTimeCounter, ulStatsAsPercentage );
1841 * // If the percentage is zero here then the task has
1842 * // consumed less than 1% of the total run time.
1843 * sprintf( pcWriteBuffer, "%s\t\t%lu\t\t<1%%\r\n", pxTaskStatusArray[ x ].pcTaskName, pxTaskStatusArray[ x ].ulRunTimeCounter );
1846 * pcWriteBuffer += strlen( ( char * ) pcWriteBuffer );
1850 * // The array is no longer needed, free the memory it consumes.
1851 * vPortFree( pxTaskStatusArray );
1856 UBaseType_t uxTaskGetSystemState( TaskStatus_t * const pxTaskStatusArray,
1857 const UBaseType_t uxArraySize,
1858 configRUN_TIME_COUNTER_TYPE * const pulTotalRunTime ) PRIVILEGED_FUNCTION;
1863 * void vTaskList( char *pcWriteBuffer );
1866 * configUSE_TRACE_FACILITY and configUSE_STATS_FORMATTING_FUNCTIONS must
1867 * both be defined as 1 for this function to be available. See the
1868 * configuration section of the FreeRTOS.org website for more information.
1870 * NOTE 1: This function will disable interrupts for its duration. It is
1871 * not intended for normal application runtime use but as a debug aid.
1873 * Lists all the current tasks, along with their current state and stack
1874 * usage high water mark.
1876 * Tasks are reported as blocked ('B'), ready ('R'), deleted ('D') or
1881 * This function is provided for convenience only, and is used by many of the
1882 * demo applications. Do not consider it to be part of the scheduler.
1884 * vTaskList() calls uxTaskGetSystemState(), then formats part of the
1885 * uxTaskGetSystemState() output into a human readable table that displays task:
1886 * names, states, priority, stack usage and task number.
1887 * Stack usage specified as the number of unused StackType_t words stack can hold
1888 * on top of stack - not the number of bytes.
1890 * vTaskList() has a dependency on the sprintf() C library function that might
1891 * bloat the code size, use a lot of stack, and provide different results on
1892 * different platforms. An alternative, tiny, third party, and limited
1893 * functionality implementation of sprintf() is provided in many of the
1894 * FreeRTOS/Demo sub-directories in a file called printf-stdarg.c (note
1895 * printf-stdarg.c does not provide a full snprintf() implementation!).
1897 * It is recommended that production systems call uxTaskGetSystemState()
1898 * directly to get access to raw stats data, rather than indirectly through a
1899 * call to vTaskList().
1901 * @param pcWriteBuffer A buffer into which the above mentioned details
1902 * will be written, in ASCII form. This buffer is assumed to be large
1903 * enough to contain the generated report. Approximately 40 bytes per
1904 * task should be sufficient.
1906 * \defgroup vTaskList vTaskList
1907 * \ingroup TaskUtils
1909 void vTaskList( char * pcWriteBuffer ) PRIVILEGED_FUNCTION; /*lint !e971 Unqualified char types are allowed for strings and single characters only. */
1914 * void vTaskGetRunTimeStats( char *pcWriteBuffer );
1917 * configGENERATE_RUN_TIME_STATS and configUSE_STATS_FORMATTING_FUNCTIONS
1918 * must both be defined as 1 for this function to be available. The application
1919 * must also then provide definitions for
1920 * portCONFIGURE_TIMER_FOR_RUN_TIME_STATS() and portGET_RUN_TIME_COUNTER_VALUE()
1921 * to configure a peripheral timer/counter and return the timers current count
1922 * value respectively. The counter should be at least 10 times the frequency of
1925 * NOTE 1: This function will disable interrupts for its duration. It is
1926 * not intended for normal application runtime use but as a debug aid.
1928 * Setting configGENERATE_RUN_TIME_STATS to 1 will result in a total
1929 * accumulated execution time being stored for each task. The resolution
1930 * of the accumulated time value depends on the frequency of the timer
1931 * configured by the portCONFIGURE_TIMER_FOR_RUN_TIME_STATS() macro.
1932 * Calling vTaskGetRunTimeStats() writes the total execution time of each
1933 * task into a buffer, both as an absolute count value and as a percentage
1934 * of the total system execution time.
1938 * This function is provided for convenience only, and is used by many of the
1939 * demo applications. Do not consider it to be part of the scheduler.
1941 * vTaskGetRunTimeStats() calls uxTaskGetSystemState(), then formats part of the
1942 * uxTaskGetSystemState() output into a human readable table that displays the
1943 * amount of time each task has spent in the Running state in both absolute and
1946 * vTaskGetRunTimeStats() has a dependency on the sprintf() C library function
1947 * that might bloat the code size, use a lot of stack, and provide different
1948 * results on different platforms. An alternative, tiny, third party, and
1949 * limited functionality implementation of sprintf() is provided in many of the
1950 * FreeRTOS/Demo sub-directories in a file called printf-stdarg.c (note
1951 * printf-stdarg.c does not provide a full snprintf() implementation!).
1953 * It is recommended that production systems call uxTaskGetSystemState() directly
1954 * to get access to raw stats data, rather than indirectly through a call to
1955 * vTaskGetRunTimeStats().
1957 * @param pcWriteBuffer A buffer into which the execution times will be
1958 * written, in ASCII form. This buffer is assumed to be large enough to
1959 * contain the generated report. Approximately 40 bytes per task should
1962 * \defgroup vTaskGetRunTimeStats vTaskGetRunTimeStats
1963 * \ingroup TaskUtils
1965 void vTaskGetRunTimeStats( char * pcWriteBuffer ) PRIVILEGED_FUNCTION; /*lint !e971 Unqualified char types are allowed for strings and single characters only. */
1970 * configRUN_TIME_COUNTER_TYPE ulTaskGetRunTimeCounter( const TaskHandle_t xTask );
1971 * configRUN_TIME_COUNTER_TYPE ulTaskGetRunTimePercent( const TaskHandle_t xTask );
1974 * configGENERATE_RUN_TIME_STATS must be defined as 1 for these functions to be
1975 * available. The application must also then provide definitions for
1976 * portCONFIGURE_TIMER_FOR_RUN_TIME_STATS() and
1977 * portGET_RUN_TIME_COUNTER_VALUE() to configure a peripheral timer/counter and
1978 * return the timers current count value respectively. The counter should be
1979 * at least 10 times the frequency of the tick count.
1981 * Setting configGENERATE_RUN_TIME_STATS to 1 will result in a total
1982 * accumulated execution time being stored for each task. The resolution
1983 * of the accumulated time value depends on the frequency of the timer
1984 * configured by the portCONFIGURE_TIMER_FOR_RUN_TIME_STATS() macro.
1985 * While uxTaskGetSystemState() and vTaskGetRunTimeStats() writes the total
1986 * execution time of each task into a buffer, ulTaskGetRunTimeCounter()
1987 * returns the total execution time of just one task and
1988 * ulTaskGetRunTimePercent() returns the percentage of the CPU time used by
1991 * @return The total run time of the given task or the percentage of the total
1992 * run time consumed by the given task. This is the amount of time the task
1993 * has actually been executing. The unit of time is dependent on the frequency
1994 * configured using the portCONFIGURE_TIMER_FOR_RUN_TIME_STATS() and
1995 * portGET_RUN_TIME_COUNTER_VALUE() macros.
1997 * \defgroup ulTaskGetRunTimeCounter ulTaskGetRunTimeCounter
1998 * \ingroup TaskUtils
2000 configRUN_TIME_COUNTER_TYPE ulTaskGetRunTimeCounter( const TaskHandle_t xTask ) PRIVILEGED_FUNCTION;
2001 configRUN_TIME_COUNTER_TYPE ulTaskGetRunTimePercent( const TaskHandle_t xTask ) PRIVILEGED_FUNCTION;
2006 * configRUN_TIME_COUNTER_TYPE ulTaskGetIdleRunTimeCounter( void );
2007 * configRUN_TIME_COUNTER_TYPE ulTaskGetIdleRunTimePercent( void );
2010 * configGENERATE_RUN_TIME_STATS must be defined as 1 for these functions to be
2011 * available. The application must also then provide definitions for
2012 * portCONFIGURE_TIMER_FOR_RUN_TIME_STATS() and
2013 * portGET_RUN_TIME_COUNTER_VALUE() to configure a peripheral timer/counter and
2014 * return the timers current count value respectively. The counter should be
2015 * at least 10 times the frequency of the tick count.
2017 * Setting configGENERATE_RUN_TIME_STATS to 1 will result in a total
2018 * accumulated execution time being stored for each task. The resolution
2019 * of the accumulated time value depends on the frequency of the timer
2020 * configured by the portCONFIGURE_TIMER_FOR_RUN_TIME_STATS() macro.
2021 * While uxTaskGetSystemState() and vTaskGetRunTimeStats() writes the total
2022 * execution time of each task into a buffer, ulTaskGetIdleRunTimeCounter()
2023 * returns the total execution time of just the idle task and
2024 * ulTaskGetIdleRunTimePercent() returns the percentage of the CPU time used by
2025 * just the idle task.
2027 * Note the amount of idle time is only a good measure of the slack time in a
2028 * system if there are no other tasks executing at the idle priority, tickless
2029 * idle is not used, and configIDLE_SHOULD_YIELD is set to 0.
2031 * @return The total run time of the idle task or the percentage of the total
2032 * run time consumed by the idle task. This is the amount of time the
2033 * idle task has actually been executing. The unit of time is dependent on the
2034 * frequency configured using the portCONFIGURE_TIMER_FOR_RUN_TIME_STATS() and
2035 * portGET_RUN_TIME_COUNTER_VALUE() macros.
2037 * \defgroup ulTaskGetIdleRunTimeCounter ulTaskGetIdleRunTimeCounter
2038 * \ingroup TaskUtils
2040 configRUN_TIME_COUNTER_TYPE ulTaskGetIdleRunTimeCounter( void ) PRIVILEGED_FUNCTION;
2041 configRUN_TIME_COUNTER_TYPE ulTaskGetIdleRunTimePercent( void ) PRIVILEGED_FUNCTION;
2046 * BaseType_t xTaskNotifyIndexed( TaskHandle_t xTaskToNotify, UBaseType_t uxIndexToNotify, uint32_t ulValue, eNotifyAction eAction );
2047 * BaseType_t xTaskNotify( TaskHandle_t xTaskToNotify, uint32_t ulValue, eNotifyAction eAction );
2050 * See https://www.FreeRTOS.org/RTOS-task-notifications.html for details.
2052 * configUSE_TASK_NOTIFICATIONS must be undefined or defined as 1 for these
2053 * functions to be available.
2055 * Sends a direct to task notification to a task, with an optional value and
2058 * Each task has a private array of "notification values" (or 'notifications'),
2059 * each of which is a 32-bit unsigned integer (uint32_t). The constant
2060 * configTASK_NOTIFICATION_ARRAY_ENTRIES sets the number of indexes in the
2061 * array, and (for backward compatibility) defaults to 1 if left undefined.
2062 * Prior to FreeRTOS V10.4.0 there was only one notification value per task.
2064 * Events can be sent to a task using an intermediary object. Examples of such
2065 * objects are queues, semaphores, mutexes and event groups. Task notifications
2066 * are a method of sending an event directly to a task without the need for such
2067 * an intermediary object.
2069 * A notification sent to a task can optionally perform an action, such as
2070 * update, overwrite or increment one of the task's notification values. In
2071 * that way task notifications can be used to send data to a task, or be used as
2072 * light weight and fast binary or counting semaphores.
2074 * A task can use xTaskNotifyWaitIndexed() or ulTaskNotifyTakeIndexed() to
2075 * [optionally] block to wait for a notification to be pending. The task does
2076 * not consume any CPU time while it is in the Blocked state.
2078 * A notification sent to a task will remain pending until it is cleared by the
2079 * task calling xTaskNotifyWaitIndexed() or ulTaskNotifyTakeIndexed() (or their
2080 * un-indexed equivalents). If the task was already in the Blocked state to
2081 * wait for a notification when the notification arrives then the task will
2082 * automatically be removed from the Blocked state (unblocked) and the
2083 * notification cleared.
2085 * **NOTE** Each notification within the array operates independently - a task
2086 * can only block on one notification within the array at a time and will not be
2087 * unblocked by a notification sent to any other array index.
2089 * Backward compatibility information:
2090 * Prior to FreeRTOS V10.4.0 each task had a single "notification value", and
2091 * all task notification API functions operated on that value. Replacing the
2092 * single notification value with an array of notification values necessitated a
2093 * new set of API functions that could address specific notifications within the
2094 * array. xTaskNotify() is the original API function, and remains backward
2095 * compatible by always operating on the notification value at index 0 in the
2096 * array. Calling xTaskNotify() is equivalent to calling xTaskNotifyIndexed()
2097 * with the uxIndexToNotify parameter set to 0.
2099 * @param xTaskToNotify The handle of the task being notified. The handle to a
2100 * task can be returned from the xTaskCreate() API function used to create the
2101 * task, and the handle of the currently running task can be obtained by calling
2102 * xTaskGetCurrentTaskHandle().
2104 * @param uxIndexToNotify The index within the target task's array of
2105 * notification values to which the notification is to be sent. uxIndexToNotify
2106 * must be less than configTASK_NOTIFICATION_ARRAY_ENTRIES. xTaskNotify() does
2107 * not have this parameter and always sends notifications to index 0.
2109 * @param ulValue Data that can be sent with the notification. How the data is
2110 * used depends on the value of the eAction parameter.
2112 * @param eAction Specifies how the notification updates the task's notification
2113 * value, if at all. Valid values for eAction are as follows:
2116 * The target notification value is bitwise ORed with ulValue.
2117 * xTaskNotifyIndexed() always returns pdPASS in this case.
2120 * The target notification value is incremented. ulValue is not used and
2121 * xTaskNotifyIndexed() always returns pdPASS in this case.
2123 * eSetValueWithOverwrite -
2124 * The target notification value is set to the value of ulValue, even if the
2125 * task being notified had not yet processed the previous notification at the
2126 * same array index (the task already had a notification pending at that index).
2127 * xTaskNotifyIndexed() always returns pdPASS in this case.
2129 * eSetValueWithoutOverwrite -
2130 * If the task being notified did not already have a notification pending at the
2131 * same array index then the target notification value is set to ulValue and
2132 * xTaskNotifyIndexed() will return pdPASS. If the task being notified already
2133 * had a notification pending at the same array index then no action is
2134 * performed and pdFAIL is returned.
2137 * The task receives a notification at the specified array index without the
2138 * notification value at that index being updated. ulValue is not used and
2139 * xTaskNotifyIndexed() always returns pdPASS in this case.
2141 * pulPreviousNotificationValue -
2142 * Can be used to pass out the subject task's notification value before any
2143 * bits are modified by the notify function.
2145 * @return Dependent on the value of eAction. See the description of the
2146 * eAction parameter.
2148 * \defgroup xTaskNotifyIndexed xTaskNotifyIndexed
2149 * \ingroup TaskNotifications
2151 BaseType_t xTaskGenericNotify( TaskHandle_t xTaskToNotify,
2152 UBaseType_t uxIndexToNotify,
2154 eNotifyAction eAction,
2155 uint32_t * pulPreviousNotificationValue ) PRIVILEGED_FUNCTION;
2156 #define xTaskNotify( xTaskToNotify, ulValue, eAction ) \
2157 xTaskGenericNotify( ( xTaskToNotify ), ( tskDEFAULT_INDEX_TO_NOTIFY ), ( ulValue ), ( eAction ), NULL )
2158 #define xTaskNotifyIndexed( xTaskToNotify, uxIndexToNotify, ulValue, eAction ) \
2159 xTaskGenericNotify( ( xTaskToNotify ), ( uxIndexToNotify ), ( ulValue ), ( eAction ), NULL )
2164 * BaseType_t xTaskNotifyAndQueryIndexed( TaskHandle_t xTaskToNotify, UBaseType_t uxIndexToNotify, uint32_t ulValue, eNotifyAction eAction, uint32_t *pulPreviousNotifyValue );
2165 * BaseType_t xTaskNotifyAndQuery( TaskHandle_t xTaskToNotify, uint32_t ulValue, eNotifyAction eAction, uint32_t *pulPreviousNotifyValue );
2168 * See https://www.FreeRTOS.org/RTOS-task-notifications.html for details.
2170 * xTaskNotifyAndQueryIndexed() performs the same operation as
2171 * xTaskNotifyIndexed() with the addition that it also returns the subject
2172 * task's prior notification value (the notification value at the time the
2173 * function is called rather than when the function returns) in the additional
2174 * pulPreviousNotifyValue parameter.
2176 * xTaskNotifyAndQuery() performs the same operation as xTaskNotify() with the
2177 * addition that it also returns the subject task's prior notification value
2178 * (the notification value as it was at the time the function is called, rather
2179 * than when the function returns) in the additional pulPreviousNotifyValue
2182 * \defgroup xTaskNotifyAndQueryIndexed xTaskNotifyAndQueryIndexed
2183 * \ingroup TaskNotifications
2185 #define xTaskNotifyAndQuery( xTaskToNotify, ulValue, eAction, pulPreviousNotifyValue ) \
2186 xTaskGenericNotify( ( xTaskToNotify ), ( tskDEFAULT_INDEX_TO_NOTIFY ), ( ulValue ), ( eAction ), ( pulPreviousNotifyValue ) )
2187 #define xTaskNotifyAndQueryIndexed( xTaskToNotify, uxIndexToNotify, ulValue, eAction, pulPreviousNotifyValue ) \
2188 xTaskGenericNotify( ( xTaskToNotify ), ( uxIndexToNotify ), ( ulValue ), ( eAction ), ( pulPreviousNotifyValue ) )
2193 * BaseType_t xTaskNotifyIndexedFromISR( TaskHandle_t xTaskToNotify, UBaseType_t uxIndexToNotify, uint32_t ulValue, eNotifyAction eAction, BaseType_t *pxHigherPriorityTaskWoken );
2194 * BaseType_t xTaskNotifyFromISR( TaskHandle_t xTaskToNotify, uint32_t ulValue, eNotifyAction eAction, BaseType_t *pxHigherPriorityTaskWoken );
2197 * See https://www.FreeRTOS.org/RTOS-task-notifications.html for details.
2199 * configUSE_TASK_NOTIFICATIONS must be undefined or defined as 1 for these
2200 * functions to be available.
2202 * A version of xTaskNotifyIndexed() that can be used from an interrupt service
2205 * Each task has a private array of "notification values" (or 'notifications'),
2206 * each of which is a 32-bit unsigned integer (uint32_t). The constant
2207 * configTASK_NOTIFICATION_ARRAY_ENTRIES sets the number of indexes in the
2208 * array, and (for backward compatibility) defaults to 1 if left undefined.
2209 * Prior to FreeRTOS V10.4.0 there was only one notification value per task.
2211 * Events can be sent to a task using an intermediary object. Examples of such
2212 * objects are queues, semaphores, mutexes and event groups. Task notifications
2213 * are a method of sending an event directly to a task without the need for such
2214 * an intermediary object.
2216 * A notification sent to a task can optionally perform an action, such as
2217 * update, overwrite or increment one of the task's notification values. In
2218 * that way task notifications can be used to send data to a task, or be used as
2219 * light weight and fast binary or counting semaphores.
2221 * A task can use xTaskNotifyWaitIndexed() to [optionally] block to wait for a
2222 * notification to be pending, or ulTaskNotifyTakeIndexed() to [optionally] block
2223 * to wait for a notification value to have a non-zero value. The task does
2224 * not consume any CPU time while it is in the Blocked state.
2226 * A notification sent to a task will remain pending until it is cleared by the
2227 * task calling xTaskNotifyWaitIndexed() or ulTaskNotifyTakeIndexed() (or their
2228 * un-indexed equivalents). If the task was already in the Blocked state to
2229 * wait for a notification when the notification arrives then the task will
2230 * automatically be removed from the Blocked state (unblocked) and the
2231 * notification cleared.
2233 * **NOTE** Each notification within the array operates independently - a task
2234 * can only block on one notification within the array at a time and will not be
2235 * unblocked by a notification sent to any other array index.
2237 * Backward compatibility information:
2238 * Prior to FreeRTOS V10.4.0 each task had a single "notification value", and
2239 * all task notification API functions operated on that value. Replacing the
2240 * single notification value with an array of notification values necessitated a
2241 * new set of API functions that could address specific notifications within the
2242 * array. xTaskNotifyFromISR() is the original API function, and remains
2243 * backward compatible by always operating on the notification value at index 0
2244 * within the array. Calling xTaskNotifyFromISR() is equivalent to calling
2245 * xTaskNotifyIndexedFromISR() with the uxIndexToNotify parameter set to 0.
2247 * @param uxIndexToNotify The index within the target task's array of
2248 * notification values to which the notification is to be sent. uxIndexToNotify
2249 * must be less than configTASK_NOTIFICATION_ARRAY_ENTRIES. xTaskNotifyFromISR()
2250 * does not have this parameter and always sends notifications to index 0.
2252 * @param xTaskToNotify The handle of the task being notified. The handle to a
2253 * task can be returned from the xTaskCreate() API function used to create the
2254 * task, and the handle of the currently running task can be obtained by calling
2255 * xTaskGetCurrentTaskHandle().
2257 * @param ulValue Data that can be sent with the notification. How the data is
2258 * used depends on the value of the eAction parameter.
2260 * @param eAction Specifies how the notification updates the task's notification
2261 * value, if at all. Valid values for eAction are as follows:
2264 * The task's notification value is bitwise ORed with ulValue. xTaskNotify()
2265 * always returns pdPASS in this case.
2268 * The task's notification value is incremented. ulValue is not used and
2269 * xTaskNotify() always returns pdPASS in this case.
2271 * eSetValueWithOverwrite -
2272 * The task's notification value is set to the value of ulValue, even if the
2273 * task being notified had not yet processed the previous notification (the
2274 * task already had a notification pending). xTaskNotify() always returns
2275 * pdPASS in this case.
2277 * eSetValueWithoutOverwrite -
2278 * If the task being notified did not already have a notification pending then
2279 * the task's notification value is set to ulValue and xTaskNotify() will
2280 * return pdPASS. If the task being notified already had a notification
2281 * pending then no action is performed and pdFAIL is returned.
2284 * The task receives a notification without its notification value being
2285 * updated. ulValue is not used and xTaskNotify() always returns pdPASS in
2288 * @param pxHigherPriorityTaskWoken xTaskNotifyFromISR() will set
2289 * *pxHigherPriorityTaskWoken to pdTRUE if sending the notification caused the
2290 * task to which the notification was sent to leave the Blocked state, and the
2291 * unblocked task has a priority higher than the currently running task. If
2292 * xTaskNotifyFromISR() sets this value to pdTRUE then a context switch should
2293 * be requested before the interrupt is exited. How a context switch is
2294 * requested from an ISR is dependent on the port - see the documentation page
2295 * for the port in use.
2297 * @return Dependent on the value of eAction. See the description of the
2298 * eAction parameter.
2300 * \defgroup xTaskNotifyIndexedFromISR xTaskNotifyIndexedFromISR
2301 * \ingroup TaskNotifications
2303 BaseType_t xTaskGenericNotifyFromISR( TaskHandle_t xTaskToNotify,
2304 UBaseType_t uxIndexToNotify,
2306 eNotifyAction eAction,
2307 uint32_t * pulPreviousNotificationValue,
2308 BaseType_t * pxHigherPriorityTaskWoken ) PRIVILEGED_FUNCTION;
2309 #define xTaskNotifyFromISR( xTaskToNotify, ulValue, eAction, pxHigherPriorityTaskWoken ) \
2310 xTaskGenericNotifyFromISR( ( xTaskToNotify ), ( tskDEFAULT_INDEX_TO_NOTIFY ), ( ulValue ), ( eAction ), NULL, ( pxHigherPriorityTaskWoken ) )
2311 #define xTaskNotifyIndexedFromISR( xTaskToNotify, uxIndexToNotify, ulValue, eAction, pxHigherPriorityTaskWoken ) \
2312 xTaskGenericNotifyFromISR( ( xTaskToNotify ), ( uxIndexToNotify ), ( ulValue ), ( eAction ), NULL, ( pxHigherPriorityTaskWoken ) )
2317 * BaseType_t xTaskNotifyAndQueryIndexedFromISR( TaskHandle_t xTaskToNotify, UBaseType_t uxIndexToNotify, uint32_t ulValue, eNotifyAction eAction, uint32_t *pulPreviousNotificationValue, BaseType_t *pxHigherPriorityTaskWoken );
2318 * BaseType_t xTaskNotifyAndQueryFromISR( TaskHandle_t xTaskToNotify, uint32_t ulValue, eNotifyAction eAction, uint32_t *pulPreviousNotificationValue, BaseType_t *pxHigherPriorityTaskWoken );
2321 * See https://www.FreeRTOS.org/RTOS-task-notifications.html for details.
2323 * xTaskNotifyAndQueryIndexedFromISR() performs the same operation as
2324 * xTaskNotifyIndexedFromISR() with the addition that it also returns the
2325 * subject task's prior notification value (the notification value at the time
2326 * the function is called rather than at the time the function returns) in the
2327 * additional pulPreviousNotifyValue parameter.
2329 * xTaskNotifyAndQueryFromISR() performs the same operation as
2330 * xTaskNotifyFromISR() with the addition that it also returns the subject
2331 * task's prior notification value (the notification value at the time the
2332 * function is called rather than at the time the function returns) in the
2333 * additional pulPreviousNotifyValue parameter.
2335 * \defgroup xTaskNotifyAndQueryIndexedFromISR xTaskNotifyAndQueryIndexedFromISR
2336 * \ingroup TaskNotifications
2338 #define xTaskNotifyAndQueryIndexedFromISR( xTaskToNotify, uxIndexToNotify, ulValue, eAction, pulPreviousNotificationValue, pxHigherPriorityTaskWoken ) \
2339 xTaskGenericNotifyFromISR( ( xTaskToNotify ), ( uxIndexToNotify ), ( ulValue ), ( eAction ), ( pulPreviousNotificationValue ), ( pxHigherPriorityTaskWoken ) )
2340 #define xTaskNotifyAndQueryFromISR( xTaskToNotify, ulValue, eAction, pulPreviousNotificationValue, pxHigherPriorityTaskWoken ) \
2341 xTaskGenericNotifyFromISR( ( xTaskToNotify ), ( tskDEFAULT_INDEX_TO_NOTIFY ), ( ulValue ), ( eAction ), ( pulPreviousNotificationValue ), ( pxHigherPriorityTaskWoken ) )
2346 * BaseType_t xTaskNotifyWaitIndexed( UBaseType_t uxIndexToWaitOn, uint32_t ulBitsToClearOnEntry, uint32_t ulBitsToClearOnExit, uint32_t *pulNotificationValue, TickType_t xTicksToWait );
2348 * BaseType_t xTaskNotifyWait( uint32_t ulBitsToClearOnEntry, uint32_t ulBitsToClearOnExit, uint32_t *pulNotificationValue, TickType_t xTicksToWait );
2351 * Waits for a direct to task notification to be pending at a given index within
2352 * an array of direct to task notifications.
2354 * See https://www.FreeRTOS.org/RTOS-task-notifications.html for details.
2356 * configUSE_TASK_NOTIFICATIONS must be undefined or defined as 1 for this
2357 * function to be available.
2359 * Each task has a private array of "notification values" (or 'notifications'),
2360 * each of which is a 32-bit unsigned integer (uint32_t). The constant
2361 * configTASK_NOTIFICATION_ARRAY_ENTRIES sets the number of indexes in the
2362 * array, and (for backward compatibility) defaults to 1 if left undefined.
2363 * Prior to FreeRTOS V10.4.0 there was only one notification value per task.
2365 * Events can be sent to a task using an intermediary object. Examples of such
2366 * objects are queues, semaphores, mutexes and event groups. Task notifications
2367 * are a method of sending an event directly to a task without the need for such
2368 * an intermediary object.
2370 * A notification sent to a task can optionally perform an action, such as
2371 * update, overwrite or increment one of the task's notification values. In
2372 * that way task notifications can be used to send data to a task, or be used as
2373 * light weight and fast binary or counting semaphores.
2375 * A notification sent to a task will remain pending until it is cleared by the
2376 * task calling xTaskNotifyWaitIndexed() or ulTaskNotifyTakeIndexed() (or their
2377 * un-indexed equivalents). If the task was already in the Blocked state to
2378 * wait for a notification when the notification arrives then the task will
2379 * automatically be removed from the Blocked state (unblocked) and the
2380 * notification cleared.
2382 * A task can use xTaskNotifyWaitIndexed() to [optionally] block to wait for a
2383 * notification to be pending, or ulTaskNotifyTakeIndexed() to [optionally] block
2384 * to wait for a notification value to have a non-zero value. The task does
2385 * not consume any CPU time while it is in the Blocked state.
2387 * **NOTE** Each notification within the array operates independently - a task
2388 * can only block on one notification within the array at a time and will not be
2389 * unblocked by a notification sent to any other array index.
2391 * Backward compatibility information:
2392 * Prior to FreeRTOS V10.4.0 each task had a single "notification value", and
2393 * all task notification API functions operated on that value. Replacing the
2394 * single notification value with an array of notification values necessitated a
2395 * new set of API functions that could address specific notifications within the
2396 * array. xTaskNotifyWait() is the original API function, and remains backward
2397 * compatible by always operating on the notification value at index 0 in the
2398 * array. Calling xTaskNotifyWait() is equivalent to calling
2399 * xTaskNotifyWaitIndexed() with the uxIndexToWaitOn parameter set to 0.
2401 * @param uxIndexToWaitOn The index within the calling task's array of
2402 * notification values on which the calling task will wait for a notification to
2403 * be received. uxIndexToWaitOn must be less than
2404 * configTASK_NOTIFICATION_ARRAY_ENTRIES. xTaskNotifyWait() does
2405 * not have this parameter and always waits for notifications on index 0.
2407 * @param ulBitsToClearOnEntry Bits that are set in ulBitsToClearOnEntry value
2408 * will be cleared in the calling task's notification value before the task
2409 * checks to see if any notifications are pending, and optionally blocks if no
2410 * notifications are pending. Setting ulBitsToClearOnEntry to ULONG_MAX (if
2411 * limits.h is included) or 0xffffffffUL (if limits.h is not included) will have
2412 * the effect of resetting the task's notification value to 0. Setting
2413 * ulBitsToClearOnEntry to 0 will leave the task's notification value unchanged.
2415 * @param ulBitsToClearOnExit If a notification is pending or received before
2416 * the calling task exits the xTaskNotifyWait() function then the task's
2417 * notification value (see the xTaskNotify() API function) is passed out using
2418 * the pulNotificationValue parameter. Then any bits that are set in
2419 * ulBitsToClearOnExit will be cleared in the task's notification value (note
2420 * *pulNotificationValue is set before any bits are cleared). Setting
2421 * ulBitsToClearOnExit to ULONG_MAX (if limits.h is included) or 0xffffffffUL
2422 * (if limits.h is not included) will have the effect of resetting the task's
2423 * notification value to 0 before the function exits. Setting
2424 * ulBitsToClearOnExit to 0 will leave the task's notification value unchanged
2425 * when the function exits (in which case the value passed out in
2426 * pulNotificationValue will match the task's notification value).
2428 * @param pulNotificationValue Used to pass the task's notification value out
2429 * of the function. Note the value passed out will not be effected by the
2430 * clearing of any bits caused by ulBitsToClearOnExit being non-zero.
2432 * @param xTicksToWait The maximum amount of time that the task should wait in
2433 * the Blocked state for a notification to be received, should a notification
2434 * not already be pending when xTaskNotifyWait() was called. The task
2435 * will not consume any processing time while it is in the Blocked state. This
2436 * is specified in kernel ticks, the macro pdMS_TO_TICKS( value_in_ms ) can be
2437 * used to convert a time specified in milliseconds to a time specified in
2440 * @return If a notification was received (including notifications that were
2441 * already pending when xTaskNotifyWait was called) then pdPASS is
2442 * returned. Otherwise pdFAIL is returned.
2444 * \defgroup xTaskNotifyWaitIndexed xTaskNotifyWaitIndexed
2445 * \ingroup TaskNotifications
2447 BaseType_t xTaskGenericNotifyWait( UBaseType_t uxIndexToWaitOn,
2448 uint32_t ulBitsToClearOnEntry,
2449 uint32_t ulBitsToClearOnExit,
2450 uint32_t * pulNotificationValue,
2451 TickType_t xTicksToWait ) PRIVILEGED_FUNCTION;
2452 #define xTaskNotifyWait( ulBitsToClearOnEntry, ulBitsToClearOnExit, pulNotificationValue, xTicksToWait ) \
2453 xTaskGenericNotifyWait( tskDEFAULT_INDEX_TO_NOTIFY, ( ulBitsToClearOnEntry ), ( ulBitsToClearOnExit ), ( pulNotificationValue ), ( xTicksToWait ) )
2454 #define xTaskNotifyWaitIndexed( uxIndexToWaitOn, ulBitsToClearOnEntry, ulBitsToClearOnExit, pulNotificationValue, xTicksToWait ) \
2455 xTaskGenericNotifyWait( ( uxIndexToWaitOn ), ( ulBitsToClearOnEntry ), ( ulBitsToClearOnExit ), ( pulNotificationValue ), ( xTicksToWait ) )
2460 * BaseType_t xTaskNotifyGiveIndexed( TaskHandle_t xTaskToNotify, UBaseType_t uxIndexToNotify );
2461 * BaseType_t xTaskNotifyGive( TaskHandle_t xTaskToNotify );
2464 * Sends a direct to task notification to a particular index in the target
2465 * task's notification array in a manner similar to giving a counting semaphore.
2467 * See https://www.FreeRTOS.org/RTOS-task-notifications.html for more details.
2469 * configUSE_TASK_NOTIFICATIONS must be undefined or defined as 1 for these
2470 * macros to be available.
2472 * Each task has a private array of "notification values" (or 'notifications'),
2473 * each of which is a 32-bit unsigned integer (uint32_t). The constant
2474 * configTASK_NOTIFICATION_ARRAY_ENTRIES sets the number of indexes in the
2475 * array, and (for backward compatibility) defaults to 1 if left undefined.
2476 * Prior to FreeRTOS V10.4.0 there was only one notification value per task.
2478 * Events can be sent to a task using an intermediary object. Examples of such
2479 * objects are queues, semaphores, mutexes and event groups. Task notifications
2480 * are a method of sending an event directly to a task without the need for such
2481 * an intermediary object.
2483 * A notification sent to a task can optionally perform an action, such as
2484 * update, overwrite or increment one of the task's notification values. In
2485 * that way task notifications can be used to send data to a task, or be used as
2486 * light weight and fast binary or counting semaphores.
2488 * xTaskNotifyGiveIndexed() is a helper macro intended for use when task
2489 * notifications are used as light weight and faster binary or counting
2490 * semaphore equivalents. Actual FreeRTOS semaphores are given using the
2491 * xSemaphoreGive() API function, the equivalent action that instead uses a task
2492 * notification is xTaskNotifyGiveIndexed().
2494 * When task notifications are being used as a binary or counting semaphore
2495 * equivalent then the task being notified should wait for the notification
2496 * using the ulTaskNotifyTakeIndexed() API function rather than the
2497 * xTaskNotifyWaitIndexed() API function.
2499 * **NOTE** Each notification within the array operates independently - a task
2500 * can only block on one notification within the array at a time and will not be
2501 * unblocked by a notification sent to any other array index.
2503 * Backward compatibility information:
2504 * Prior to FreeRTOS V10.4.0 each task had a single "notification value", and
2505 * all task notification API functions operated on that value. Replacing the
2506 * single notification value with an array of notification values necessitated a
2507 * new set of API functions that could address specific notifications within the
2508 * array. xTaskNotifyGive() is the original API function, and remains backward
2509 * compatible by always operating on the notification value at index 0 in the
2510 * array. Calling xTaskNotifyGive() is equivalent to calling
2511 * xTaskNotifyGiveIndexed() with the uxIndexToNotify parameter set to 0.
2513 * @param xTaskToNotify The handle of the task being notified. The handle to a
2514 * task can be returned from the xTaskCreate() API function used to create the
2515 * task, and the handle of the currently running task can be obtained by calling
2516 * xTaskGetCurrentTaskHandle().
2518 * @param uxIndexToNotify The index within the target task's array of
2519 * notification values to which the notification is to be sent. uxIndexToNotify
2520 * must be less than configTASK_NOTIFICATION_ARRAY_ENTRIES. xTaskNotifyGive()
2521 * does not have this parameter and always sends notifications to index 0.
2523 * @return xTaskNotifyGive() is a macro that calls xTaskNotify() with the
2524 * eAction parameter set to eIncrement - so pdPASS is always returned.
2526 * \defgroup xTaskNotifyGiveIndexed xTaskNotifyGiveIndexed
2527 * \ingroup TaskNotifications
2529 #define xTaskNotifyGive( xTaskToNotify ) \
2530 xTaskGenericNotify( ( xTaskToNotify ), ( tskDEFAULT_INDEX_TO_NOTIFY ), ( 0 ), eIncrement, NULL )
2531 #define xTaskNotifyGiveIndexed( xTaskToNotify, uxIndexToNotify ) \
2532 xTaskGenericNotify( ( xTaskToNotify ), ( uxIndexToNotify ), ( 0 ), eIncrement, NULL )
2537 * void vTaskNotifyGiveIndexedFromISR( TaskHandle_t xTaskHandle, UBaseType_t uxIndexToNotify, BaseType_t *pxHigherPriorityTaskWoken );
2538 * void vTaskNotifyGiveFromISR( TaskHandle_t xTaskHandle, BaseType_t *pxHigherPriorityTaskWoken );
2541 * A version of xTaskNotifyGiveIndexed() that can be called from an interrupt
2542 * service routine (ISR).
2544 * See https://www.FreeRTOS.org/RTOS-task-notifications.html for more details.
2546 * configUSE_TASK_NOTIFICATIONS must be undefined or defined as 1 for this macro
2549 * Each task has a private array of "notification values" (or 'notifications'),
2550 * each of which is a 32-bit unsigned integer (uint32_t). The constant
2551 * configTASK_NOTIFICATION_ARRAY_ENTRIES sets the number of indexes in the
2552 * array, and (for backward compatibility) defaults to 1 if left undefined.
2553 * Prior to FreeRTOS V10.4.0 there was only one notification value per task.
2555 * Events can be sent to a task using an intermediary object. Examples of such
2556 * objects are queues, semaphores, mutexes and event groups. Task notifications
2557 * are a method of sending an event directly to a task without the need for such
2558 * an intermediary object.
2560 * A notification sent to a task can optionally perform an action, such as
2561 * update, overwrite or increment one of the task's notification values. In
2562 * that way task notifications can be used to send data to a task, or be used as
2563 * light weight and fast binary or counting semaphores.
2565 * vTaskNotifyGiveIndexedFromISR() is intended for use when task notifications
2566 * are used as light weight and faster binary or counting semaphore equivalents.
2567 * Actual FreeRTOS semaphores are given from an ISR using the
2568 * xSemaphoreGiveFromISR() API function, the equivalent action that instead uses
2569 * a task notification is vTaskNotifyGiveIndexedFromISR().
2571 * When task notifications are being used as a binary or counting semaphore
2572 * equivalent then the task being notified should wait for the notification
2573 * using the ulTaskNotifyTakeIndexed() API function rather than the
2574 * xTaskNotifyWaitIndexed() API function.
2576 * **NOTE** Each notification within the array operates independently - a task
2577 * can only block on one notification within the array at a time and will not be
2578 * unblocked by a notification sent to any other array index.
2580 * Backward compatibility information:
2581 * Prior to FreeRTOS V10.4.0 each task had a single "notification value", and
2582 * all task notification API functions operated on that value. Replacing the
2583 * single notification value with an array of notification values necessitated a
2584 * new set of API functions that could address specific notifications within the
2585 * array. xTaskNotifyFromISR() is the original API function, and remains
2586 * backward compatible by always operating on the notification value at index 0
2587 * within the array. Calling xTaskNotifyGiveFromISR() is equivalent to calling
2588 * xTaskNotifyGiveIndexedFromISR() with the uxIndexToNotify parameter set to 0.
2590 * @param xTaskToNotify The handle of the task being notified. The handle to a
2591 * task can be returned from the xTaskCreate() API function used to create the
2592 * task, and the handle of the currently running task can be obtained by calling
2593 * xTaskGetCurrentTaskHandle().
2595 * @param uxIndexToNotify The index within the target task's array of
2596 * notification values to which the notification is to be sent. uxIndexToNotify
2597 * must be less than configTASK_NOTIFICATION_ARRAY_ENTRIES.
2598 * xTaskNotifyGiveFromISR() does not have this parameter and always sends
2599 * notifications to index 0.
2601 * @param pxHigherPriorityTaskWoken vTaskNotifyGiveFromISR() will set
2602 * *pxHigherPriorityTaskWoken to pdTRUE if sending the notification caused the
2603 * task to which the notification was sent to leave the Blocked state, and the
2604 * unblocked task has a priority higher than the currently running task. If
2605 * vTaskNotifyGiveFromISR() sets this value to pdTRUE then a context switch
2606 * should be requested before the interrupt is exited. How a context switch is
2607 * requested from an ISR is dependent on the port - see the documentation page
2608 * for the port in use.
2610 * \defgroup vTaskNotifyGiveIndexedFromISR vTaskNotifyGiveIndexedFromISR
2611 * \ingroup TaskNotifications
2613 void vTaskGenericNotifyGiveFromISR( TaskHandle_t xTaskToNotify,
2614 UBaseType_t uxIndexToNotify,
2615 BaseType_t * pxHigherPriorityTaskWoken ) PRIVILEGED_FUNCTION;
2616 #define vTaskNotifyGiveFromISR( xTaskToNotify, pxHigherPriorityTaskWoken ) \
2617 vTaskGenericNotifyGiveFromISR( ( xTaskToNotify ), ( tskDEFAULT_INDEX_TO_NOTIFY ), ( pxHigherPriorityTaskWoken ) )
2618 #define vTaskNotifyGiveIndexedFromISR( xTaskToNotify, uxIndexToNotify, pxHigherPriorityTaskWoken ) \
2619 vTaskGenericNotifyGiveFromISR( ( xTaskToNotify ), ( uxIndexToNotify ), ( pxHigherPriorityTaskWoken ) )
2624 * uint32_t ulTaskNotifyTakeIndexed( UBaseType_t uxIndexToWaitOn, BaseType_t xClearCountOnExit, TickType_t xTicksToWait );
2626 * uint32_t ulTaskNotifyTake( BaseType_t xClearCountOnExit, TickType_t xTicksToWait );
2629 * Waits for a direct to task notification on a particular index in the calling
2630 * task's notification array in a manner similar to taking a counting semaphore.
2632 * See https://www.FreeRTOS.org/RTOS-task-notifications.html for details.
2634 * configUSE_TASK_NOTIFICATIONS must be undefined or defined as 1 for this
2635 * function to be available.
2637 * Each task has a private array of "notification values" (or 'notifications'),
2638 * each of which is a 32-bit unsigned integer (uint32_t). The constant
2639 * configTASK_NOTIFICATION_ARRAY_ENTRIES sets the number of indexes in the
2640 * array, and (for backward compatibility) defaults to 1 if left undefined.
2641 * Prior to FreeRTOS V10.4.0 there was only one notification value per task.
2643 * Events can be sent to a task using an intermediary object. Examples of such
2644 * objects are queues, semaphores, mutexes and event groups. Task notifications
2645 * are a method of sending an event directly to a task without the need for such
2646 * an intermediary object.
2648 * A notification sent to a task can optionally perform an action, such as
2649 * update, overwrite or increment one of the task's notification values. In
2650 * that way task notifications can be used to send data to a task, or be used as
2651 * light weight and fast binary or counting semaphores.
2653 * ulTaskNotifyTakeIndexed() is intended for use when a task notification is
2654 * used as a faster and lighter weight binary or counting semaphore alternative.
2655 * Actual FreeRTOS semaphores are taken using the xSemaphoreTake() API function,
2656 * the equivalent action that instead uses a task notification is
2657 * ulTaskNotifyTakeIndexed().
2659 * When a task is using its notification value as a binary or counting semaphore
2660 * other tasks should send notifications to it using the xTaskNotifyGiveIndexed()
2661 * macro, or xTaskNotifyIndex() function with the eAction parameter set to
2664 * ulTaskNotifyTakeIndexed() can either clear the task's notification value at
2665 * the array index specified by the uxIndexToWaitOn parameter to zero on exit,
2666 * in which case the notification value acts like a binary semaphore, or
2667 * decrement the notification value on exit, in which case the notification
2668 * value acts like a counting semaphore.
2670 * A task can use ulTaskNotifyTakeIndexed() to [optionally] block to wait for
2671 * a notification. The task does not consume any CPU time while it is in the
2674 * Where as xTaskNotifyWaitIndexed() will return when a notification is pending,
2675 * ulTaskNotifyTakeIndexed() will return when the task's notification value is
2678 * **NOTE** Each notification within the array operates independently - a task
2679 * can only block on one notification within the array at a time and will not be
2680 * unblocked by a notification sent to any other array index.
2682 * Backward compatibility information:
2683 * Prior to FreeRTOS V10.4.0 each task had a single "notification value", and
2684 * all task notification API functions operated on that value. Replacing the
2685 * single notification value with an array of notification values necessitated a
2686 * new set of API functions that could address specific notifications within the
2687 * array. ulTaskNotifyTake() is the original API function, and remains backward
2688 * compatible by always operating on the notification value at index 0 in the
2689 * array. Calling ulTaskNotifyTake() is equivalent to calling
2690 * ulTaskNotifyTakeIndexed() with the uxIndexToWaitOn parameter set to 0.
2692 * @param uxIndexToWaitOn The index within the calling task's array of
2693 * notification values on which the calling task will wait for a notification to
2694 * be non-zero. uxIndexToWaitOn must be less than
2695 * configTASK_NOTIFICATION_ARRAY_ENTRIES. xTaskNotifyTake() does
2696 * not have this parameter and always waits for notifications on index 0.
2698 * @param xClearCountOnExit if xClearCountOnExit is pdFALSE then the task's
2699 * notification value is decremented when the function exits. In this way the
2700 * notification value acts like a counting semaphore. If xClearCountOnExit is
2701 * not pdFALSE then the task's notification value is cleared to zero when the
2702 * function exits. In this way the notification value acts like a binary
2705 * @param xTicksToWait The maximum amount of time that the task should wait in
2706 * the Blocked state for the task's notification value to be greater than zero,
2707 * should the count not already be greater than zero when
2708 * ulTaskNotifyTake() was called. The task will not consume any processing
2709 * time while it is in the Blocked state. This is specified in kernel ticks,
2710 * the macro pdMS_TO_TICKS( value_in_ms ) can be used to convert a time
2711 * specified in milliseconds to a time specified in ticks.
2713 * @return The task's notification count before it is either cleared to zero or
2714 * decremented (see the xClearCountOnExit parameter).
2716 * \defgroup ulTaskNotifyTakeIndexed ulTaskNotifyTakeIndexed
2717 * \ingroup TaskNotifications
2719 uint32_t ulTaskGenericNotifyTake( UBaseType_t uxIndexToWaitOn,
2720 BaseType_t xClearCountOnExit,
2721 TickType_t xTicksToWait ) PRIVILEGED_FUNCTION;
2722 #define ulTaskNotifyTake( xClearCountOnExit, xTicksToWait ) \
2723 ulTaskGenericNotifyTake( ( tskDEFAULT_INDEX_TO_NOTIFY ), ( xClearCountOnExit ), ( xTicksToWait ) )
2724 #define ulTaskNotifyTakeIndexed( uxIndexToWaitOn, xClearCountOnExit, xTicksToWait ) \
2725 ulTaskGenericNotifyTake( ( uxIndexToWaitOn ), ( xClearCountOnExit ), ( xTicksToWait ) )
2730 * BaseType_t xTaskNotifyStateClearIndexed( TaskHandle_t xTask, UBaseType_t uxIndexToCLear );
2732 * BaseType_t xTaskNotifyStateClear( TaskHandle_t xTask );
2735 * See https://www.FreeRTOS.org/RTOS-task-notifications.html for details.
2737 * configUSE_TASK_NOTIFICATIONS must be undefined or defined as 1 for these
2738 * functions to be available.
2740 * Each task has a private array of "notification values" (or 'notifications'),
2741 * each of which is a 32-bit unsigned integer (uint32_t). The constant
2742 * configTASK_NOTIFICATION_ARRAY_ENTRIES sets the number of indexes in the
2743 * array, and (for backward compatibility) defaults to 1 if left undefined.
2744 * Prior to FreeRTOS V10.4.0 there was only one notification value per task.
2746 * If a notification is sent to an index within the array of notifications then
2747 * the notification at that index is said to be 'pending' until it is read or
2748 * explicitly cleared by the receiving task. xTaskNotifyStateClearIndexed()
2749 * is the function that clears a pending notification without reading the
2750 * notification value. The notification value at the same array index is not
2751 * altered. Set xTask to NULL to clear the notification state of the calling
2754 * Backward compatibility information:
2755 * Prior to FreeRTOS V10.4.0 each task had a single "notification value", and
2756 * all task notification API functions operated on that value. Replacing the
2757 * single notification value with an array of notification values necessitated a
2758 * new set of API functions that could address specific notifications within the
2759 * array. xTaskNotifyStateClear() is the original API function, and remains
2760 * backward compatible by always operating on the notification value at index 0
2761 * within the array. Calling xTaskNotifyStateClear() is equivalent to calling
2762 * xTaskNotifyStateClearIndexed() with the uxIndexToNotify parameter set to 0.
2764 * @param xTask The handle of the RTOS task that will have a notification state
2765 * cleared. Set xTask to NULL to clear a notification state in the calling
2766 * task. To obtain a task's handle create the task using xTaskCreate() and
2767 * make use of the pxCreatedTask parameter, or create the task using
2768 * xTaskCreateStatic() and store the returned value, or use the task's name in
2769 * a call to xTaskGetHandle().
2771 * @param uxIndexToClear The index within the target task's array of
2772 * notification values to act upon. For example, setting uxIndexToClear to 1
2773 * will clear the state of the notification at index 1 within the array.
2774 * uxIndexToClear must be less than configTASK_NOTIFICATION_ARRAY_ENTRIES.
2775 * ulTaskNotifyStateClear() does not have this parameter and always acts on the
2776 * notification at index 0.
2778 * @return pdTRUE if the task's notification state was set to
2779 * eNotWaitingNotification, otherwise pdFALSE.
2781 * \defgroup xTaskNotifyStateClearIndexed xTaskNotifyStateClearIndexed
2782 * \ingroup TaskNotifications
2784 BaseType_t xTaskGenericNotifyStateClear( TaskHandle_t xTask,
2785 UBaseType_t uxIndexToClear ) PRIVILEGED_FUNCTION;
2786 #define xTaskNotifyStateClear( xTask ) \
2787 xTaskGenericNotifyStateClear( ( xTask ), ( tskDEFAULT_INDEX_TO_NOTIFY ) )
2788 #define xTaskNotifyStateClearIndexed( xTask, uxIndexToClear ) \
2789 xTaskGenericNotifyStateClear( ( xTask ), ( uxIndexToClear ) )
2794 * uint32_t ulTaskNotifyValueClearIndexed( TaskHandle_t xTask, UBaseType_t uxIndexToClear, uint32_t ulBitsToClear );
2796 * uint32_t ulTaskNotifyValueClear( TaskHandle_t xTask, uint32_t ulBitsToClear );
2799 * See https://www.FreeRTOS.org/RTOS-task-notifications.html for details.
2801 * configUSE_TASK_NOTIFICATIONS must be undefined or defined as 1 for these
2802 * functions to be available.
2804 * Each task has a private array of "notification values" (or 'notifications'),
2805 * each of which is a 32-bit unsigned integer (uint32_t). The constant
2806 * configTASK_NOTIFICATION_ARRAY_ENTRIES sets the number of indexes in the
2807 * array, and (for backward compatibility) defaults to 1 if left undefined.
2808 * Prior to FreeRTOS V10.4.0 there was only one notification value per task.
2810 * ulTaskNotifyValueClearIndexed() clears the bits specified by the
2811 * ulBitsToClear bit mask in the notification value at array index uxIndexToClear
2812 * of the task referenced by xTask.
2814 * Backward compatibility information:
2815 * Prior to FreeRTOS V10.4.0 each task had a single "notification value", and
2816 * all task notification API functions operated on that value. Replacing the
2817 * single notification value with an array of notification values necessitated a
2818 * new set of API functions that could address specific notifications within the
2819 * array. ulTaskNotifyValueClear() is the original API function, and remains
2820 * backward compatible by always operating on the notification value at index 0
2821 * within the array. Calling ulTaskNotifyValueClear() is equivalent to calling
2822 * ulTaskNotifyValueClearIndexed() with the uxIndexToClear parameter set to 0.
2824 * @param xTask The handle of the RTOS task that will have bits in one of its
2825 * notification values cleared. Set xTask to NULL to clear bits in a
2826 * notification value of the calling task. To obtain a task's handle create the
2827 * task using xTaskCreate() and make use of the pxCreatedTask parameter, or
2828 * create the task using xTaskCreateStatic() and store the returned value, or
2829 * use the task's name in a call to xTaskGetHandle().
2831 * @param uxIndexToClear The index within the target task's array of
2832 * notification values in which to clear the bits. uxIndexToClear
2833 * must be less than configTASK_NOTIFICATION_ARRAY_ENTRIES.
2834 * ulTaskNotifyValueClear() does not have this parameter and always clears bits
2835 * in the notification value at index 0.
2837 * @param ulBitsToClear Bit mask of the bits to clear in the notification value of
2838 * xTask. Set a bit to 1 to clear the corresponding bits in the task's notification
2839 * value. Set ulBitsToClear to 0xffffffff (UINT_MAX on 32-bit architectures) to clear
2840 * the notification value to 0. Set ulBitsToClear to 0 to query the task's
2841 * notification value without clearing any bits.
2844 * @return The value of the target task's notification value before the bits
2845 * specified by ulBitsToClear were cleared.
2846 * \defgroup ulTaskNotifyValueClear ulTaskNotifyValueClear
2847 * \ingroup TaskNotifications
2849 uint32_t ulTaskGenericNotifyValueClear( TaskHandle_t xTask,
2850 UBaseType_t uxIndexToClear,
2851 uint32_t ulBitsToClear ) PRIVILEGED_FUNCTION;
2852 #define ulTaskNotifyValueClear( xTask, ulBitsToClear ) \
2853 ulTaskGenericNotifyValueClear( ( xTask ), ( tskDEFAULT_INDEX_TO_NOTIFY ), ( ulBitsToClear ) )
2854 #define ulTaskNotifyValueClearIndexed( xTask, uxIndexToClear, ulBitsToClear ) \
2855 ulTaskGenericNotifyValueClear( ( xTask ), ( uxIndexToClear ), ( ulBitsToClear ) )
2860 * void vTaskSetTimeOutState( TimeOut_t * const pxTimeOut );
2863 * Capture the current time for future use with xTaskCheckForTimeOut().
2865 * @param pxTimeOut Pointer to a timeout object into which the current time
2866 * is to be captured. The captured time includes the tick count and the number
2867 * of times the tick count has overflowed since the system first booted.
2868 * \defgroup vTaskSetTimeOutState vTaskSetTimeOutState
2871 void vTaskSetTimeOutState( TimeOut_t * const pxTimeOut ) PRIVILEGED_FUNCTION;
2876 * BaseType_t xTaskCheckForTimeOut( TimeOut_t * const pxTimeOut, TickType_t * const pxTicksToWait );
2879 * Determines if pxTicksToWait ticks has passed since a time was captured
2880 * using a call to vTaskSetTimeOutState(). The captured time includes the tick
2881 * count and the number of times the tick count has overflowed.
2883 * @param pxTimeOut The time status as captured previously using
2884 * vTaskSetTimeOutState. If the timeout has not yet occurred, it is updated
2885 * to reflect the current time status.
2886 * @param pxTicksToWait The number of ticks to check for timeout i.e. if
2887 * pxTicksToWait ticks have passed since pxTimeOut was last updated (either by
2888 * vTaskSetTimeOutState() or xTaskCheckForTimeOut()), the timeout has occurred.
2889 * If the timeout has not occurred, pxTicksToWait is updated to reflect the
2890 * number of remaining ticks.
2892 * @return If timeout has occurred, pdTRUE is returned. Otherwise pdFALSE is
2893 * returned and pxTicksToWait is updated to reflect the number of remaining
2896 * @see https://www.FreeRTOS.org/xTaskCheckForTimeOut.html
2900 * // Driver library function used to receive uxWantedBytes from an Rx buffer
2901 * // that is filled by a UART interrupt. If there are not enough bytes in the
2902 * // Rx buffer then the task enters the Blocked state until it is notified that
2903 * // more data has been placed into the buffer. If there is still not enough
2904 * // data then the task re-enters the Blocked state, and xTaskCheckForTimeOut()
2905 * // is used to re-calculate the Block time to ensure the total amount of time
2906 * // spent in the Blocked state does not exceed MAX_TIME_TO_WAIT. This
2907 * // continues until either the buffer contains at least uxWantedBytes bytes,
2908 * // or the total amount of time spent in the Blocked state reaches
2909 * // MAX_TIME_TO_WAIT - at which point the task reads however many bytes are
2910 * // available up to a maximum of uxWantedBytes.
2912 * size_t xUART_Receive( uint8_t *pucBuffer, size_t uxWantedBytes )
2914 * size_t uxReceived = 0;
2915 * TickType_t xTicksToWait = MAX_TIME_TO_WAIT;
2916 * TimeOut_t xTimeOut;
2918 * // Initialize xTimeOut. This records the time at which this function
2920 * vTaskSetTimeOutState( &xTimeOut );
2922 * // Loop until the buffer contains the wanted number of bytes, or a
2923 * // timeout occurs.
2924 * while( UART_bytes_in_rx_buffer( pxUARTInstance ) < uxWantedBytes )
2926 * // The buffer didn't contain enough data so this task is going to
2927 * // enter the Blocked state. Adjusting xTicksToWait to account for
2928 * // any time that has been spent in the Blocked state within this
2929 * // function so far to ensure the total amount of time spent in the
2930 * // Blocked state does not exceed MAX_TIME_TO_WAIT.
2931 * if( xTaskCheckForTimeOut( &xTimeOut, &xTicksToWait ) != pdFALSE )
2933 * //Timed out before the wanted number of bytes were available,
2938 * // Wait for a maximum of xTicksToWait ticks to be notified that the
2939 * // receive interrupt has placed more data into the buffer.
2940 * ulTaskNotifyTake( pdTRUE, xTicksToWait );
2943 * // Attempt to read uxWantedBytes from the receive buffer into pucBuffer.
2944 * // The actual number of bytes read (which might be less than
2945 * // uxWantedBytes) is returned.
2946 * uxReceived = UART_read_from_receive_buffer( pxUARTInstance,
2950 * return uxReceived;
2953 * \defgroup xTaskCheckForTimeOut xTaskCheckForTimeOut
2956 BaseType_t xTaskCheckForTimeOut( TimeOut_t * const pxTimeOut,
2957 TickType_t * const pxTicksToWait ) PRIVILEGED_FUNCTION;
2962 * BaseType_t xTaskCatchUpTicks( TickType_t xTicksToCatchUp );
2965 * This function corrects the tick count value after the application code has held
2966 * interrupts disabled for an extended period resulting in tick interrupts having
2969 * This function is similar to vTaskStepTick(), however, unlike
2970 * vTaskStepTick(), xTaskCatchUpTicks() may move the tick count forward past a
2971 * time at which a task should be removed from the blocked state. That means
2972 * tasks may have to be removed from the blocked state as the tick count is
2975 * @param xTicksToCatchUp The number of tick interrupts that have been missed due to
2976 * interrupts being disabled. Its value is not computed automatically, so must be
2977 * computed by the application writer.
2979 * @return pdTRUE if moving the tick count forward resulted in a task leaving the
2980 * blocked state and a context switch being performed. Otherwise pdFALSE.
2982 * \defgroup xTaskCatchUpTicks xTaskCatchUpTicks
2985 BaseType_t xTaskCatchUpTicks( TickType_t xTicksToCatchUp ) PRIVILEGED_FUNCTION;
2988 /*-----------------------------------------------------------
2989 * SCHEDULER INTERNALS AVAILABLE FOR PORTING PURPOSES
2990 *----------------------------------------------------------*/
2993 * THIS FUNCTION MUST NOT BE USED FROM APPLICATION CODE. IT IS ONLY
2994 * INTENDED FOR USE WHEN IMPLEMENTING A PORT OF THE SCHEDULER AND IS
2995 * AN INTERFACE WHICH IS FOR THE EXCLUSIVE USE OF THE SCHEDULER.
2997 * Called from the real time kernel tick (either preemptive or cooperative),
2998 * this increments the tick count and checks if any tasks that are blocked
2999 * for a finite period required removing from a blocked list and placing on
3000 * a ready list. If a non-zero value is returned then a context switch is
3001 * required because either:
3002 * + A task was removed from a blocked list because its timeout had expired,
3004 * + Time slicing is in use and there is a task of equal priority to the
3005 * currently running task.
3007 BaseType_t xTaskIncrementTick( void ) PRIVILEGED_FUNCTION;
3010 * THIS FUNCTION MUST NOT BE USED FROM APPLICATION CODE. IT IS AN
3011 * INTERFACE WHICH IS FOR THE EXCLUSIVE USE OF THE SCHEDULER.
3013 * THIS FUNCTION MUST BE CALLED WITH INTERRUPTS DISABLED.
3015 * Removes the calling task from the ready list and places it both
3016 * on the list of tasks waiting for a particular event, and the
3017 * list of delayed tasks. The task will be removed from both lists
3018 * and replaced on the ready list should either the event occur (and
3019 * there be no higher priority tasks waiting on the same event) or
3020 * the delay period expires.
3022 * The 'unordered' version replaces the event list item value with the
3023 * xItemValue value, and inserts the list item at the end of the list.
3025 * The 'ordered' version uses the existing event list item value (which is the
3026 * owning task's priority) to insert the list item into the event list in task
3029 * @param pxEventList The list containing tasks that are blocked waiting
3030 * for the event to occur.
3032 * @param xItemValue The item value to use for the event list item when the
3033 * event list is not ordered by task priority.
3035 * @param xTicksToWait The maximum amount of time that the task should wait
3036 * for the event to occur. This is specified in kernel ticks, the constant
3037 * portTICK_PERIOD_MS can be used to convert kernel ticks into a real time
3040 void vTaskPlaceOnEventList( List_t * const pxEventList,
3041 const TickType_t xTicksToWait ) PRIVILEGED_FUNCTION;
3042 void vTaskPlaceOnUnorderedEventList( List_t * pxEventList,
3043 const TickType_t xItemValue,
3044 const TickType_t xTicksToWait ) PRIVILEGED_FUNCTION;
3047 * THIS FUNCTION MUST NOT BE USED FROM APPLICATION CODE. IT IS AN
3048 * INTERFACE WHICH IS FOR THE EXCLUSIVE USE OF THE SCHEDULER.
3050 * THIS FUNCTION MUST BE CALLED WITH INTERRUPTS DISABLED.
3052 * This function performs nearly the same function as vTaskPlaceOnEventList().
3053 * The difference being that this function does not permit tasks to block
3054 * indefinitely, whereas vTaskPlaceOnEventList() does.
3057 void vTaskPlaceOnEventListRestricted( List_t * const pxEventList,
3058 TickType_t xTicksToWait,
3059 const BaseType_t xWaitIndefinitely ) PRIVILEGED_FUNCTION;
3062 * THIS FUNCTION MUST NOT BE USED FROM APPLICATION CODE. IT IS AN
3063 * INTERFACE WHICH IS FOR THE EXCLUSIVE USE OF THE SCHEDULER.
3065 * THIS FUNCTION MUST BE CALLED WITH INTERRUPTS DISABLED.
3067 * Removes a task from both the specified event list and the list of blocked
3068 * tasks, and places it on a ready queue.
3070 * xTaskRemoveFromEventList()/vTaskRemoveFromUnorderedEventList() will be called
3071 * if either an event occurs to unblock a task, or the block timeout period
3074 * xTaskRemoveFromEventList() is used when the event list is in task priority
3075 * order. It removes the list item from the head of the event list as that will
3076 * have the highest priority owning task of all the tasks on the event list.
3077 * vTaskRemoveFromUnorderedEventList() is used when the event list is not
3078 * ordered and the event list items hold something other than the owning tasks
3079 * priority. In this case the event list item value is updated to the value
3080 * passed in the xItemValue parameter.
3082 * @return pdTRUE if the task being removed has a higher priority than the task
3083 * making the call, otherwise pdFALSE.
3085 BaseType_t xTaskRemoveFromEventList( const List_t * const pxEventList ) PRIVILEGED_FUNCTION;
3086 void vTaskRemoveFromUnorderedEventList( ListItem_t * pxEventListItem,
3087 const TickType_t xItemValue ) PRIVILEGED_FUNCTION;
3090 * THIS FUNCTION MUST NOT BE USED FROM APPLICATION CODE. IT IS ONLY
3091 * INTENDED FOR USE WHEN IMPLEMENTING A PORT OF THE SCHEDULER AND IS
3092 * AN INTERFACE WHICH IS FOR THE EXCLUSIVE USE OF THE SCHEDULER.
3094 * Sets the pointer to the current TCB to the TCB of the highest priority task
3095 * that is ready to run.
3097 portDONT_DISCARD void vTaskSwitchContext( void ) PRIVILEGED_FUNCTION;
3100 * THESE FUNCTIONS MUST NOT BE USED FROM APPLICATION CODE. THEY ARE USED BY
3101 * THE EVENT BITS MODULE.
3103 TickType_t uxTaskResetEventItemValue( void ) PRIVILEGED_FUNCTION;
3106 * Return the handle of the calling task.
3108 TaskHandle_t xTaskGetCurrentTaskHandle( void ) PRIVILEGED_FUNCTION;
3111 * Shortcut used by the queue implementation to prevent unnecessary call to
3114 void vTaskMissedYield( void ) PRIVILEGED_FUNCTION;
3117 * Returns the scheduler state as taskSCHEDULER_RUNNING,
3118 * taskSCHEDULER_NOT_STARTED or taskSCHEDULER_SUSPENDED.
3120 BaseType_t xTaskGetSchedulerState( void ) PRIVILEGED_FUNCTION;
3123 * Raises the priority of the mutex holder to that of the calling task should
3124 * the mutex holder have a priority less than the calling task.
3126 BaseType_t xTaskPriorityInherit( TaskHandle_t const pxMutexHolder ) PRIVILEGED_FUNCTION;
3129 * Set the priority of a task back to its proper priority in the case that it
3130 * inherited a higher priority while it was holding a semaphore.
3132 BaseType_t xTaskPriorityDisinherit( TaskHandle_t const pxMutexHolder ) PRIVILEGED_FUNCTION;
3135 * If a higher priority task attempting to obtain a mutex caused a lower
3136 * priority task to inherit the higher priority task's priority - but the higher
3137 * priority task then timed out without obtaining the mutex, then the lower
3138 * priority task will disinherit the priority again - but only down as far as
3139 * the highest priority task that is still waiting for the mutex (if there were
3140 * more than one task waiting for the mutex).
3142 void vTaskPriorityDisinheritAfterTimeout( TaskHandle_t const pxMutexHolder,
3143 UBaseType_t uxHighestPriorityWaitingTask ) PRIVILEGED_FUNCTION;
3146 * Get the uxTaskNumber assigned to the task referenced by the xTask parameter.
3148 UBaseType_t uxTaskGetTaskNumber( TaskHandle_t xTask ) PRIVILEGED_FUNCTION;
3151 * Set the uxTaskNumber of the task referenced by the xTask parameter to
3154 void vTaskSetTaskNumber( TaskHandle_t xTask,
3155 const UBaseType_t uxHandle ) PRIVILEGED_FUNCTION;
3158 * Only available when configUSE_TICKLESS_IDLE is set to 1.
3159 * If tickless mode is being used, or a low power mode is implemented, then
3160 * the tick interrupt will not execute during idle periods. When this is the
3161 * case, the tick count value maintained by the scheduler needs to be kept up
3162 * to date with the actual execution time by being skipped forward by a time
3163 * equal to the idle period.
3165 void vTaskStepTick( TickType_t xTicksToJump ) PRIVILEGED_FUNCTION;
3168 * Only available when configUSE_TICKLESS_IDLE is set to 1.
3169 * Provided for use within portSUPPRESS_TICKS_AND_SLEEP() to allow the port
3170 * specific sleep function to determine if it is ok to proceed with the sleep,
3171 * and if it is ok to proceed, if it is ok to sleep indefinitely.
3173 * This function is necessary because portSUPPRESS_TICKS_AND_SLEEP() is only
3174 * called with the scheduler suspended, not from within a critical section. It
3175 * is therefore possible for an interrupt to request a context switch between
3176 * portSUPPRESS_TICKS_AND_SLEEP() and the low power mode actually being
3177 * entered. eTaskConfirmSleepModeStatus() should be called from a short
3178 * critical section between the timer being stopped and the sleep mode being
3179 * entered to ensure it is ok to proceed into the sleep mode.
3181 eSleepModeStatus eTaskConfirmSleepModeStatus( void ) PRIVILEGED_FUNCTION;
3184 * For internal use only. Increment the mutex held count when a mutex is
3185 * taken and return the handle of the task that has taken the mutex.
3187 TaskHandle_t pvTaskIncrementMutexHeldCount( void ) PRIVILEGED_FUNCTION;
3190 * For internal use only. Same as vTaskSetTimeOutState(), but without a critical
3193 void vTaskInternalSetTimeOutState( TimeOut_t * const pxTimeOut ) PRIVILEGED_FUNCTION;
3201 #endif /* INC_TASK_H */