2 * FreeRTOS Kernel <DEVELOPMENT BRANCH>
3 * Copyright (C) 2021 Amazon.com, Inc. or its affiliates. All Rights Reserved.
5 * SPDX-License-Identifier: MIT
7 * Permission is hereby granted, free of charge, to any person obtaining a copy of
8 * this software and associated documentation files (the "Software"), to deal in
9 * the Software without restriction, including without limitation the rights to
10 * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
11 * the Software, and to permit persons to whom the Software is furnished to do so,
12 * subject to the following conditions:
14 * The above copyright notice and this permission notice shall be included in all
15 * copies or substantial portions of the Software.
17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
18 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
19 * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
20 * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
21 * IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
22 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
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 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. */
167 /* Possible return values for eTaskConfirmSleepModeStatus(). */
170 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. */
171 eStandardSleep, /* Enter a sleep mode that will not last any longer than the expected idle time. */
172 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. */
176 * Defines the priority used by the idle task. This must not be modified.
180 #define tskIDLE_PRIORITY ( ( UBaseType_t ) 0U )
185 * Macro for forcing a context switch.
187 * \defgroup taskYIELD taskYIELD
188 * \ingroup SchedulerControl
190 #define taskYIELD() portYIELD()
195 * Macro to mark the start of a critical code region. Preemptive context
196 * switches cannot occur when in a critical region.
198 * NOTE: This may alter the stack (depending on the portable implementation)
199 * so must be used with care!
201 * \defgroup taskENTER_CRITICAL taskENTER_CRITICAL
202 * \ingroup SchedulerControl
204 #define taskENTER_CRITICAL() portENTER_CRITICAL()
205 #define taskENTER_CRITICAL_FROM_ISR() portSET_INTERRUPT_MASK_FROM_ISR()
210 * Macro to mark the end of a critical code region. Preemptive context
211 * switches cannot occur when in a critical region.
213 * NOTE: This may alter the stack (depending on the portable implementation)
214 * so must be used with care!
216 * \defgroup taskEXIT_CRITICAL taskEXIT_CRITICAL
217 * \ingroup SchedulerControl
219 #define taskEXIT_CRITICAL() portEXIT_CRITICAL()
220 #define taskEXIT_CRITICAL_FROM_ISR( x ) portCLEAR_INTERRUPT_MASK_FROM_ISR( x )
225 * Macro to disable all maskable interrupts.
227 * \defgroup taskDISABLE_INTERRUPTS taskDISABLE_INTERRUPTS
228 * \ingroup SchedulerControl
230 #define taskDISABLE_INTERRUPTS() portDISABLE_INTERRUPTS()
235 * Macro to enable microcontroller interrupts.
237 * \defgroup taskENABLE_INTERRUPTS taskENABLE_INTERRUPTS
238 * \ingroup SchedulerControl
240 #define taskENABLE_INTERRUPTS() portENABLE_INTERRUPTS()
242 /* Definitions returned by xTaskGetSchedulerState(). taskSCHEDULER_SUSPENDED is
243 * 0 to generate more optimal code when configASSERT() is defined as the constant
244 * is used in assert() statements. */
245 #define taskSCHEDULER_SUSPENDED ( ( BaseType_t ) 0 )
246 #define taskSCHEDULER_NOT_STARTED ( ( BaseType_t ) 1 )
247 #define taskSCHEDULER_RUNNING ( ( BaseType_t ) 2 )
250 /*-----------------------------------------------------------
252 *----------------------------------------------------------*/
257 * BaseType_t xTaskCreate(
258 * TaskFunction_t pxTaskCode,
259 * const char *pcName,
260 * configSTACK_DEPTH_TYPE usStackDepth,
261 * void *pvParameters,
262 * UBaseType_t uxPriority,
263 * TaskHandle_t *pxCreatedTask
267 * Create a new task and add it to the list of tasks that are ready to run.
269 * Internally, within the FreeRTOS implementation, tasks use two blocks of
270 * memory. The first block is used to hold the task's data structures. The
271 * second block is used by the task as its stack. If a task is created using
272 * xTaskCreate() then both blocks of memory are automatically dynamically
273 * allocated inside the xTaskCreate() function. (see
274 * https://www.FreeRTOS.org/a00111.html). If a task is created using
275 * xTaskCreateStatic() then the application writer must provide the required
276 * memory. xTaskCreateStatic() therefore allows a task to be created without
277 * using any dynamic memory allocation.
279 * See xTaskCreateStatic() for a version that does not use any dynamic memory
282 * xTaskCreate() can only be used to create a task that has unrestricted
283 * access to the entire microcontroller memory map. Systems that include MPU
284 * support can alternatively create an MPU constrained task using
285 * xTaskCreateRestricted().
287 * @param pxTaskCode Pointer to the task entry function. Tasks
288 * must be implemented to never return (i.e. continuous loop).
290 * @param pcName A descriptive name for the task. This is mainly used to
291 * facilitate debugging. Max length defined by configMAX_TASK_NAME_LEN - default
294 * @param usStackDepth The size of the task stack specified as the number of
295 * variables the stack can hold - not the number of bytes. For example, if
296 * the stack is 16 bits wide and usStackDepth is defined as 100, 200 bytes
297 * will be allocated for stack storage.
299 * @param pvParameters Pointer that will be used as the parameter for the task
302 * @param uxPriority The priority at which the task should run. Systems that
303 * include MPU support can optionally create tasks in a privileged (system)
304 * mode by setting bit portPRIVILEGE_BIT of the priority parameter. For
305 * example, to create a privileged task at priority 2 the uxPriority parameter
306 * should be set to ( 2 | portPRIVILEGE_BIT ).
308 * @param pxCreatedTask Used to pass back a handle by which the created task
311 * @return pdPASS if the task was successfully created and added to a ready
312 * list, otherwise an error code defined in the file projdefs.h
316 * // Task to be created.
317 * void vTaskCode( void * pvParameters )
321 * // Task code goes here.
325 * // Function that creates a task.
326 * void vOtherFunction( void )
328 * static uint8_t ucParameterToPass;
329 * TaskHandle_t xHandle = NULL;
331 * // Create the task, storing the handle. Note that the passed parameter ucParameterToPass
332 * // must exist for the lifetime of the task, so in this case is declared static. If it was just an
333 * // an automatic stack variable it might no longer exist, or at least have been corrupted, by the time
334 * // the new task attempts to access it.
335 * xTaskCreate( vTaskCode, "NAME", STACK_SIZE, &ucParameterToPass, tskIDLE_PRIORITY, &xHandle );
336 * configASSERT( xHandle );
338 * // Use the handle to delete the task.
339 * if( xHandle != NULL )
341 * vTaskDelete( xHandle );
345 * \defgroup xTaskCreate xTaskCreate
348 #if ( configSUPPORT_DYNAMIC_ALLOCATION == 1 )
349 BaseType_t xTaskCreate( TaskFunction_t pxTaskCode,
350 const char * const pcName, /*lint !e971 Unqualified char types are allowed for strings and single characters only. */
351 const configSTACK_DEPTH_TYPE usStackDepth,
352 void * const pvParameters,
353 UBaseType_t uxPriority,
354 TaskHandle_t * const pxCreatedTask ) PRIVILEGED_FUNCTION;
360 * TaskHandle_t xTaskCreateStatic( TaskFunction_t pxTaskCode,
361 * const char *pcName,
362 * uint32_t ulStackDepth,
363 * void *pvParameters,
364 * UBaseType_t uxPriority,
365 * StackType_t *puxStackBuffer,
366 * StaticTask_t *pxTaskBuffer );
369 * Create a new task and add it to the list of tasks that are ready to run.
371 * Internally, within the FreeRTOS implementation, tasks use two blocks of
372 * memory. The first block is used to hold the task's data structures. The
373 * second block is used by the task as its stack. If a task is created using
374 * xTaskCreate() then both blocks of memory are automatically dynamically
375 * allocated inside the xTaskCreate() function. (see
376 * https://www.FreeRTOS.org/a00111.html). If a task is created using
377 * xTaskCreateStatic() then the application writer must provide the required
378 * memory. xTaskCreateStatic() therefore allows a task to be created without
379 * using any dynamic memory allocation.
381 * @param pxTaskCode Pointer to the task entry function. Tasks
382 * must be implemented to never return (i.e. continuous loop).
384 * @param pcName A descriptive name for the task. This is mainly used to
385 * facilitate debugging. The maximum length of the string is defined by
386 * configMAX_TASK_NAME_LEN in FreeRTOSConfig.h.
388 * @param ulStackDepth The size of the task stack specified as the number of
389 * variables the stack can hold - not the number of bytes. For example, if
390 * the stack is 32-bits wide and ulStackDepth is defined as 100 then 400 bytes
391 * will be allocated for stack storage.
393 * @param pvParameters Pointer that will be used as the parameter for the task
396 * @param uxPriority The priority at which the task will run.
398 * @param puxStackBuffer Must point to a StackType_t array that has at least
399 * ulStackDepth indexes - the array will then be used as the task's stack,
400 * removing the need for the stack to be allocated dynamically.
402 * @param pxTaskBuffer Must point to a variable of type StaticTask_t, which will
403 * then be used to hold the task's data structures, removing the need for the
404 * memory to be allocated dynamically.
406 * @return If neither puxStackBuffer nor pxTaskBuffer are NULL, then the task
407 * will be created and a handle to the created task is returned. If either
408 * puxStackBuffer or pxTaskBuffer are NULL then the task will not be created and
414 * // Dimensions of the buffer that the task being created will use as its stack.
415 * // NOTE: This is the number of words the stack will hold, not the number of
416 * // bytes. For example, if each stack item is 32-bits, and this is set to 100,
417 * // then 400 bytes (100 * 32-bits) will be allocated.
418 #define STACK_SIZE 200
420 * // Structure that will hold the TCB of the task being created.
421 * StaticTask_t xTaskBuffer;
423 * // Buffer that the task being created will use as its stack. Note this is
424 * // an array of StackType_t variables. The size of StackType_t is dependent on
426 * StackType_t xStack[ STACK_SIZE ];
428 * // Function that implements the task being created.
429 * void vTaskCode( void * pvParameters )
431 * // The parameter value is expected to be 1 as 1 is passed in the
432 * // pvParameters value in the call to xTaskCreateStatic().
433 * configASSERT( ( uint32_t ) pvParameters == 1UL );
437 * // Task code goes here.
441 * // Function that creates a task.
442 * void vOtherFunction( void )
444 * TaskHandle_t xHandle = NULL;
446 * // Create the task without using any dynamic memory allocation.
447 * xHandle = xTaskCreateStatic(
448 * vTaskCode, // Function that implements the task.
449 * "NAME", // Text name for the task.
450 * STACK_SIZE, // Stack size in words, not bytes.
451 * ( void * ) 1, // Parameter passed into the task.
452 * tskIDLE_PRIORITY,// Priority at which the task is created.
453 * xStack, // Array to use as the task's stack.
454 * &xTaskBuffer ); // Variable to hold the task's data structure.
456 * // puxStackBuffer and pxTaskBuffer were not NULL, so the task will have
457 * // been created, and xHandle will be the task's handle. Use the handle
458 * // to suspend the task.
459 * vTaskSuspend( xHandle );
462 * \defgroup xTaskCreateStatic xTaskCreateStatic
465 #if ( configSUPPORT_STATIC_ALLOCATION == 1 )
466 TaskHandle_t xTaskCreateStatic( TaskFunction_t pxTaskCode,
467 const char * const pcName, /*lint !e971 Unqualified char types are allowed for strings and single characters only. */
468 const uint32_t ulStackDepth,
469 void * const pvParameters,
470 UBaseType_t uxPriority,
471 StackType_t * const puxStackBuffer,
472 StaticTask_t * const pxTaskBuffer ) PRIVILEGED_FUNCTION;
473 #endif /* configSUPPORT_STATIC_ALLOCATION */
478 * BaseType_t xTaskCreateRestricted( TaskParameters_t *pxTaskDefinition, TaskHandle_t *pxCreatedTask );
481 * Only available when configSUPPORT_DYNAMIC_ALLOCATION is set to 1.
483 * xTaskCreateRestricted() should only be used in systems that include an MPU
486 * Create a new task and add it to the list of tasks that are ready to run.
487 * The function parameters define the memory regions and associated access
488 * permissions allocated to the task.
490 * See xTaskCreateRestrictedStatic() for a version that does not use any
491 * dynamic memory allocation.
493 * @param pxTaskDefinition Pointer to a structure that contains a member
494 * for each of the normal xTaskCreate() parameters (see the xTaskCreate() API
495 * documentation) plus an optional stack buffer and the memory region
498 * @param pxCreatedTask Used to pass back a handle by which the created task
501 * @return pdPASS if the task was successfully created and added to a ready
502 * list, otherwise an error code defined in the file projdefs.h
506 * // Create an TaskParameters_t structure that defines the task to be created.
507 * static const TaskParameters_t xCheckTaskParameters =
509 * vATask, // pvTaskCode - the function that implements the task.
510 * "ATask", // pcName - just a text name for the task to assist debugging.
511 * 100, // usStackDepth - the stack size DEFINED IN WORDS.
512 * NULL, // pvParameters - passed into the task function as the function parameters.
513 * ( 1UL | portPRIVILEGE_BIT ),// uxPriority - task priority, set the portPRIVILEGE_BIT if the task should run in a privileged state.
514 * cStackBuffer,// puxStackBuffer - the buffer to be used as the task stack.
516 * // xRegions - Allocate up to three separate memory regions for access by
517 * // the task, with appropriate access permissions. Different processors have
518 * // different memory alignment requirements - refer to the FreeRTOS documentation
519 * // for full information.
521 * // Base address Length Parameters
522 * { cReadWriteArray, 32, portMPU_REGION_READ_WRITE },
523 * { cReadOnlyArray, 32, portMPU_REGION_READ_ONLY },
524 * { cPrivilegedOnlyAccessArray, 128, portMPU_REGION_PRIVILEGED_READ_WRITE }
530 * TaskHandle_t xHandle;
532 * // Create a task from the const structure defined above. The task handle
533 * // is requested (the second parameter is not NULL) but in this case just for
534 * // demonstration purposes as its not actually used.
535 * xTaskCreateRestricted( &xRegTest1Parameters, &xHandle );
537 * // Start the scheduler.
538 * vTaskStartScheduler();
540 * // Will only get here if there was insufficient memory to create the idle
541 * // and/or timer task.
545 * \defgroup xTaskCreateRestricted xTaskCreateRestricted
548 #if ( portUSING_MPU_WRAPPERS == 1 )
549 BaseType_t xTaskCreateRestricted( const TaskParameters_t * const pxTaskDefinition,
550 TaskHandle_t * pxCreatedTask ) PRIVILEGED_FUNCTION;
556 * BaseType_t xTaskCreateRestrictedStatic( TaskParameters_t *pxTaskDefinition, TaskHandle_t *pxCreatedTask );
559 * Only available when configSUPPORT_STATIC_ALLOCATION is set to 1.
561 * xTaskCreateRestrictedStatic() should only be used in systems that include an
562 * MPU implementation.
564 * Internally, within the FreeRTOS implementation, tasks use two blocks of
565 * memory. The first block is used to hold the task's data structures. The
566 * second block is used by the task as its stack. If a task is created using
567 * xTaskCreateRestricted() then the stack is provided by the application writer,
568 * and the memory used to hold the task's data structure is automatically
569 * dynamically allocated inside the xTaskCreateRestricted() function. If a task
570 * is created using xTaskCreateRestrictedStatic() then the application writer
571 * must provide the memory used to hold the task's data structures too.
572 * xTaskCreateRestrictedStatic() therefore allows a memory protected task to be
573 * created without using any dynamic memory allocation.
575 * @param pxTaskDefinition Pointer to a structure that contains a member
576 * for each of the normal xTaskCreate() parameters (see the xTaskCreate() API
577 * documentation) plus an optional stack buffer and the memory region
578 * definitions. If configSUPPORT_STATIC_ALLOCATION is set to 1 the structure
579 * contains an additional member, which is used to point to a variable of type
580 * StaticTask_t - which is then used to hold the task's data structure.
582 * @param pxCreatedTask Used to pass back a handle by which the created task
585 * @return pdPASS if the task was successfully created and added to a ready
586 * list, otherwise an error code defined in the file projdefs.h
590 * // Create an TaskParameters_t structure that defines the task to be created.
591 * // The StaticTask_t variable is only included in the structure when
592 * // configSUPPORT_STATIC_ALLOCATION is set to 1. The PRIVILEGED_DATA macro can
593 * // be used to force the variable into the RTOS kernel's privileged data area.
594 * static PRIVILEGED_DATA StaticTask_t xTaskBuffer;
595 * static const TaskParameters_t xCheckTaskParameters =
597 * vATask, // pvTaskCode - the function that implements the task.
598 * "ATask", // pcName - just a text name for the task to assist debugging.
599 * 100, // usStackDepth - the stack size DEFINED IN WORDS.
600 * NULL, // pvParameters - passed into the task function as the function parameters.
601 * ( 1UL | portPRIVILEGE_BIT ),// uxPriority - task priority, set the portPRIVILEGE_BIT if the task should run in a privileged state.
602 * cStackBuffer,// puxStackBuffer - the buffer to be used as the task stack.
604 * // xRegions - Allocate up to three separate memory regions for access by
605 * // the task, with appropriate access permissions. Different processors have
606 * // different memory alignment requirements - refer to the FreeRTOS documentation
607 * // for full information.
609 * // Base address Length Parameters
610 * { cReadWriteArray, 32, portMPU_REGION_READ_WRITE },
611 * { cReadOnlyArray, 32, portMPU_REGION_READ_ONLY },
612 * { cPrivilegedOnlyAccessArray, 128, portMPU_REGION_PRIVILEGED_READ_WRITE }
615 * &xTaskBuffer; // Holds the task's data structure.
620 * TaskHandle_t xHandle;
622 * // Create a task from the const structure defined above. The task handle
623 * // is requested (the second parameter is not NULL) but in this case just for
624 * // demonstration purposes as its not actually used.
625 * xTaskCreateRestricted( &xRegTest1Parameters, &xHandle );
627 * // Start the scheduler.
628 * vTaskStartScheduler();
630 * // Will only get here if there was insufficient memory to create the idle
631 * // and/or timer task.
635 * \defgroup xTaskCreateRestrictedStatic xTaskCreateRestrictedStatic
638 #if ( ( portUSING_MPU_WRAPPERS == 1 ) && ( configSUPPORT_STATIC_ALLOCATION == 1 ) )
639 BaseType_t xTaskCreateRestrictedStatic( const TaskParameters_t * const pxTaskDefinition,
640 TaskHandle_t * pxCreatedTask ) PRIVILEGED_FUNCTION;
646 * void vTaskAllocateMPURegions( TaskHandle_t xTask, const MemoryRegion_t * const pxRegions );
649 * Memory regions are assigned to a restricted task when the task is created by
650 * a call to xTaskCreateRestricted(). These regions can be redefined using
651 * vTaskAllocateMPURegions().
653 * @param xTask The handle of the task being updated.
655 * @param xRegions A pointer to a MemoryRegion_t structure that contains the
656 * new memory region definitions.
660 * // Define an array of MemoryRegion_t structures that configures an MPU region
661 * // allowing read/write access for 1024 bytes starting at the beginning of the
662 * // ucOneKByte array. The other two of the maximum 3 definable regions are
663 * // unused so set to zero.
664 * static const MemoryRegion_t xAltRegions[ portNUM_CONFIGURABLE_REGIONS ] =
666 * // Base address Length Parameters
667 * { ucOneKByte, 1024, portMPU_REGION_READ_WRITE },
672 * void vATask( void *pvParameters )
674 * // This task was created such that it has access to certain regions of
675 * // memory as defined by the MPU configuration. At some point it is
676 * // desired that these MPU regions are replaced with that defined in the
677 * // xAltRegions const struct above. Use a call to vTaskAllocateMPURegions()
678 * // for this purpose. NULL is used as the task handle to indicate that this
679 * // function should modify the MPU regions of the calling task.
680 * vTaskAllocateMPURegions( NULL, xAltRegions );
682 * // Now the task can continue its function, but from this point on can only
683 * // access its stack and the ucOneKByte array (unless any other statically
684 * // defined or shared regions have been declared elsewhere).
687 * \defgroup xTaskCreateRestricted xTaskCreateRestricted
690 void vTaskAllocateMPURegions( TaskHandle_t xTask,
691 const MemoryRegion_t * const pxRegions ) PRIVILEGED_FUNCTION;
696 * void vTaskDelete( TaskHandle_t xTaskToDelete );
699 * INCLUDE_vTaskDelete must be defined as 1 for this function to be available.
700 * See the configuration section for more information.
702 * Remove a task from the RTOS real time kernel's management. The task being
703 * deleted will be removed from all ready, blocked, suspended and event lists.
705 * NOTE: The idle task is responsible for freeing the kernel allocated
706 * memory from tasks that have been deleted. It is therefore important that
707 * the idle task is not starved of microcontroller processing time if your
708 * application makes any calls to vTaskDelete (). Memory allocated by the
709 * task code is not automatically freed, and should be freed before the task
712 * See the demo application file death.c for sample code that utilises
715 * @param xTaskToDelete The handle of the task to be deleted. Passing NULL will
716 * cause the calling task to be deleted.
720 * void vOtherFunction( void )
722 * TaskHandle_t xHandle;
724 * // Create the task, storing the handle.
725 * xTaskCreate( vTaskCode, "NAME", STACK_SIZE, NULL, tskIDLE_PRIORITY, &xHandle );
727 * // Use the handle to delete the task.
728 * vTaskDelete( xHandle );
731 * \defgroup vTaskDelete vTaskDelete
734 void vTaskDelete( TaskHandle_t xTaskToDelete ) PRIVILEGED_FUNCTION;
736 /*-----------------------------------------------------------
738 *----------------------------------------------------------*/
743 * void vTaskDelay( const TickType_t xTicksToDelay );
746 * Delay a task for a given number of ticks. The actual time that the
747 * task remains blocked depends on the tick rate. The constant
748 * portTICK_PERIOD_MS can be used to calculate real time from the tick
749 * rate - with the resolution of one tick period.
751 * INCLUDE_vTaskDelay must be defined as 1 for this function to be available.
752 * See the configuration section for more information.
755 * vTaskDelay() specifies a time at which the task wishes to unblock relative to
756 * the time at which vTaskDelay() is called. For example, specifying a block
757 * period of 100 ticks will cause the task to unblock 100 ticks after
758 * vTaskDelay() is called. vTaskDelay() does not therefore provide a good method
759 * of controlling the frequency of a periodic task as the path taken through the
760 * code, as well as other task and interrupt activity, will affect the frequency
761 * at which vTaskDelay() gets called and therefore the time at which the task
762 * next executes. See xTaskDelayUntil() for an alternative API function designed
763 * to facilitate fixed frequency execution. It does this by specifying an
764 * absolute time (rather than a relative time) at which the calling task should
767 * @param xTicksToDelay The amount of time, in tick periods, that
768 * the calling task should block.
772 * void vTaskFunction( void * pvParameters )
774 * // Block for 500ms.
775 * const TickType_t xDelay = 500 / portTICK_PERIOD_MS;
779 * // Simply toggle the LED every 500ms, blocking between each toggle.
781 * vTaskDelay( xDelay );
785 * \defgroup vTaskDelay vTaskDelay
788 void vTaskDelay( const TickType_t xTicksToDelay ) PRIVILEGED_FUNCTION;
793 * BaseType_t xTaskDelayUntil( TickType_t *pxPreviousWakeTime, const TickType_t xTimeIncrement );
796 * INCLUDE_xTaskDelayUntil must be defined as 1 for this function to be available.
797 * See the configuration section for more information.
799 * Delay a task until a specified time. This function can be used by periodic
800 * tasks to ensure a constant execution frequency.
802 * This function differs from vTaskDelay () in one important aspect: vTaskDelay () will
803 * cause a task to block for the specified number of ticks from the time vTaskDelay () is
804 * called. It is therefore difficult to use vTaskDelay () by itself to generate a fixed
805 * execution frequency as the time between a task starting to execute and that task
806 * calling vTaskDelay () may not be fixed [the task may take a different path though the
807 * code between calls, or may get interrupted or preempted a different number of times
808 * each time it executes].
810 * Whereas vTaskDelay () specifies a wake time relative to the time at which the function
811 * is called, xTaskDelayUntil () specifies the absolute (exact) time at which it wishes to
814 * The macro pdMS_TO_TICKS() can be used to calculate the number of ticks from a
815 * time specified in milliseconds with a resolution of one tick period.
817 * @param pxPreviousWakeTime Pointer to a variable that holds the time at which the
818 * task was last unblocked. The variable must be initialised with the current time
819 * prior to its first use (see the example below). Following this the variable is
820 * automatically updated within xTaskDelayUntil ().
822 * @param xTimeIncrement The cycle time period. The task will be unblocked at
823 * time *pxPreviousWakeTime + xTimeIncrement. Calling xTaskDelayUntil with the
824 * same xTimeIncrement parameter value will cause the task to execute with
825 * a fixed interface period.
827 * @return Value which can be used to check whether the task was actually delayed.
828 * Will be pdTRUE if the task way delayed and pdFALSE otherwise. A task will not
829 * be delayed if the next expected wake time is in the past.
833 * // Perform an action every 10 ticks.
834 * void vTaskFunction( void * pvParameters )
836 * TickType_t xLastWakeTime;
837 * const TickType_t xFrequency = 10;
838 * BaseType_t xWasDelayed;
840 * // Initialise the xLastWakeTime variable with the current time.
841 * xLastWakeTime = xTaskGetTickCount ();
844 * // Wait for the next cycle.
845 * xWasDelayed = xTaskDelayUntil( &xLastWakeTime, xFrequency );
847 * // Perform action here. xWasDelayed value can be used to determine
848 * // whether a deadline was missed if the code here took too long.
852 * \defgroup xTaskDelayUntil xTaskDelayUntil
855 BaseType_t xTaskDelayUntil( TickType_t * const pxPreviousWakeTime,
856 const TickType_t xTimeIncrement ) PRIVILEGED_FUNCTION;
859 * vTaskDelayUntil() is the older version of xTaskDelayUntil() and does not
862 #define vTaskDelayUntil( pxPreviousWakeTime, xTimeIncrement ) \
864 ( void ) xTaskDelayUntil( pxPreviousWakeTime, xTimeIncrement ); \
871 * BaseType_t xTaskAbortDelay( TaskHandle_t xTask );
874 * INCLUDE_xTaskAbortDelay must be defined as 1 in FreeRTOSConfig.h for this
875 * function to be available.
877 * A task will enter the Blocked state when it is waiting for an event. The
878 * event it is waiting for can be a temporal event (waiting for a time), such
879 * as when vTaskDelay() is called, or an event on an object, such as when
880 * xQueueReceive() or ulTaskNotifyTake() is called. If the handle of a task
881 * that is in the Blocked state is used in a call to xTaskAbortDelay() then the
882 * task will leave the Blocked state, and return from whichever function call
883 * placed the task into the Blocked state.
885 * There is no 'FromISR' version of this function as an interrupt would need to
886 * know which object a task was blocked on in order to know which actions to
887 * take. For example, if the task was blocked on a queue the interrupt handler
888 * would then need to know if the queue was locked.
890 * @param xTask The handle of the task to remove from the Blocked state.
892 * @return If the task referenced by xTask was not in the Blocked state then
893 * pdFAIL is returned. Otherwise pdPASS is returned.
895 * \defgroup xTaskAbortDelay xTaskAbortDelay
898 BaseType_t xTaskAbortDelay( TaskHandle_t xTask ) PRIVILEGED_FUNCTION;
903 * UBaseType_t uxTaskPriorityGet( const TaskHandle_t xTask );
906 * INCLUDE_uxTaskPriorityGet must be defined as 1 for this function to be available.
907 * See the configuration section for more information.
909 * Obtain the priority of any task.
911 * @param xTask Handle of the task to be queried. Passing a NULL
912 * handle results in the priority of the calling task being returned.
914 * @return The priority of xTask.
918 * void vAFunction( void )
920 * TaskHandle_t xHandle;
922 * // Create a task, storing the handle.
923 * xTaskCreate( vTaskCode, "NAME", STACK_SIZE, NULL, tskIDLE_PRIORITY, &xHandle );
927 * // Use the handle to obtain the priority of the created task.
928 * // It was created with tskIDLE_PRIORITY, but may have changed
930 * if( uxTaskPriorityGet( xHandle ) != tskIDLE_PRIORITY )
932 * // The task has changed it's priority.
937 * // Is our priority higher than the created task?
938 * if( uxTaskPriorityGet( xHandle ) < uxTaskPriorityGet( NULL ) )
940 * // Our priority (obtained using NULL handle) is higher.
944 * \defgroup uxTaskPriorityGet uxTaskPriorityGet
947 UBaseType_t uxTaskPriorityGet( const TaskHandle_t xTask ) PRIVILEGED_FUNCTION;
952 * UBaseType_t uxTaskPriorityGetFromISR( const TaskHandle_t xTask );
955 * A version of uxTaskPriorityGet() that can be used from an ISR.
957 UBaseType_t uxTaskPriorityGetFromISR( const TaskHandle_t xTask ) PRIVILEGED_FUNCTION;
962 * eTaskState eTaskGetState( TaskHandle_t xTask );
965 * INCLUDE_eTaskGetState must be defined as 1 for this function to be available.
966 * See the configuration section for more information.
968 * Obtain the state of any task. States are encoded by the eTaskState
971 * @param xTask Handle of the task to be queried.
973 * @return The state of xTask at the time the function was called. Note the
974 * state of the task might change between the function being called, and the
975 * functions return value being tested by the calling task.
977 eTaskState eTaskGetState( TaskHandle_t xTask ) PRIVILEGED_FUNCTION;
982 * void vTaskGetInfo( TaskHandle_t xTask, TaskStatus_t *pxTaskStatus, BaseType_t xGetFreeStackSpace, eTaskState eState );
985 * configUSE_TRACE_FACILITY must be defined as 1 for this function to be
986 * available. See the configuration section for more information.
988 * Populates a TaskStatus_t structure with information about a task.
990 * @param xTask Handle of the task being queried. If xTask is NULL then
991 * information will be returned about the calling task.
993 * @param pxTaskStatus A pointer to the TaskStatus_t structure that will be
994 * filled with information about the task referenced by the handle passed using
995 * the xTask parameter.
997 * @xGetFreeStackSpace The TaskStatus_t structure contains a member to report
998 * the stack high water mark of the task being queried. Calculating the stack
999 * high water mark takes a relatively long time, and can make the system
1000 * temporarily unresponsive - so the xGetFreeStackSpace parameter is provided to
1001 * allow the high water mark checking to be skipped. The high watermark value
1002 * will only be written to the TaskStatus_t structure if xGetFreeStackSpace is
1003 * not set to pdFALSE;
1005 * @param eState The TaskStatus_t structure contains a member to report the
1006 * state of the task being queried. Obtaining the task state is not as fast as
1007 * a simple assignment - so the eState parameter is provided to allow the state
1008 * information to be omitted from the TaskStatus_t structure. To obtain state
1009 * information then set eState to eInvalid - otherwise the value passed in
1010 * eState will be reported as the task state in the TaskStatus_t structure.
1014 * void vAFunction( void )
1016 * TaskHandle_t xHandle;
1017 * TaskStatus_t xTaskDetails;
1019 * // Obtain the handle of a task from its name.
1020 * xHandle = xTaskGetHandle( "Task_Name" );
1022 * // Check the handle is not NULL.
1023 * configASSERT( xHandle );
1025 * // Use the handle to obtain further information about the task.
1026 * vTaskGetInfo( xHandle,
1028 * pdTRUE, // Include the high water mark in xTaskDetails.
1029 * eInvalid ); // Include the task state in xTaskDetails.
1032 * \defgroup vTaskGetInfo vTaskGetInfo
1035 void vTaskGetInfo( TaskHandle_t xTask,
1036 TaskStatus_t * pxTaskStatus,
1037 BaseType_t xGetFreeStackSpace,
1038 eTaskState eState ) PRIVILEGED_FUNCTION;
1043 * void vTaskPrioritySet( TaskHandle_t xTask, UBaseType_t uxNewPriority );
1046 * INCLUDE_vTaskPrioritySet must be defined as 1 for this function to be available.
1047 * See the configuration section for more information.
1049 * Set the priority of any task.
1051 * A context switch will occur before the function returns if the priority
1052 * being set is higher than the currently executing task.
1054 * @param xTask Handle to the task for which the priority is being set.
1055 * Passing a NULL handle results in the priority of the calling task being set.
1057 * @param uxNewPriority The priority to which the task will be set.
1061 * void vAFunction( void )
1063 * TaskHandle_t xHandle;
1065 * // Create a task, storing the handle.
1066 * xTaskCreate( vTaskCode, "NAME", STACK_SIZE, NULL, tskIDLE_PRIORITY, &xHandle );
1070 * // Use the handle to raise the priority of the created task.
1071 * vTaskPrioritySet( xHandle, tskIDLE_PRIORITY + 1 );
1075 * // Use a NULL handle to raise our priority to the same value.
1076 * vTaskPrioritySet( NULL, tskIDLE_PRIORITY + 1 );
1079 * \defgroup vTaskPrioritySet vTaskPrioritySet
1082 void vTaskPrioritySet( TaskHandle_t xTask,
1083 UBaseType_t uxNewPriority ) PRIVILEGED_FUNCTION;
1088 * void vTaskSuspend( TaskHandle_t xTaskToSuspend );
1091 * INCLUDE_vTaskSuspend must be defined as 1 for this function to be available.
1092 * See the configuration section for more information.
1094 * Suspend any task. When suspended a task will never get any microcontroller
1095 * processing time, no matter what its priority.
1097 * Calls to vTaskSuspend are not accumulative -
1098 * i.e. calling vTaskSuspend () twice on the same task still only requires one
1099 * call to vTaskResume () to ready the suspended task.
1101 * @param xTaskToSuspend Handle to the task being suspended. Passing a NULL
1102 * handle will cause the calling task to be suspended.
1106 * void vAFunction( void )
1108 * TaskHandle_t xHandle;
1110 * // Create a task, storing the handle.
1111 * xTaskCreate( vTaskCode, "NAME", STACK_SIZE, NULL, tskIDLE_PRIORITY, &xHandle );
1115 * // Use the handle to suspend the created task.
1116 * vTaskSuspend( xHandle );
1120 * // The created task will not run during this period, unless
1121 * // another task calls vTaskResume( xHandle ).
1126 * // Suspend ourselves.
1127 * vTaskSuspend( NULL );
1129 * // We cannot get here unless another task calls vTaskResume
1130 * // with our handle as the parameter.
1133 * \defgroup vTaskSuspend vTaskSuspend
1136 void vTaskSuspend( TaskHandle_t xTaskToSuspend ) PRIVILEGED_FUNCTION;
1141 * void vTaskResume( TaskHandle_t xTaskToResume );
1144 * INCLUDE_vTaskSuspend must be defined as 1 for this function to be available.
1145 * See the configuration section for more information.
1147 * Resumes a suspended task.
1149 * A task that has been suspended by one or more calls to vTaskSuspend ()
1150 * will be made available for running again by a single call to
1153 * @param xTaskToResume Handle to the task being readied.
1157 * void vAFunction( void )
1159 * TaskHandle_t xHandle;
1161 * // Create a task, storing the handle.
1162 * xTaskCreate( vTaskCode, "NAME", STACK_SIZE, NULL, tskIDLE_PRIORITY, &xHandle );
1166 * // Use the handle to suspend the created task.
1167 * vTaskSuspend( xHandle );
1171 * // The created task will not run during this period, unless
1172 * // another task calls vTaskResume( xHandle ).
1177 * // Resume the suspended task ourselves.
1178 * vTaskResume( xHandle );
1180 * // The created task will once again get microcontroller processing
1181 * // time in accordance with its priority within the system.
1184 * \defgroup vTaskResume vTaskResume
1187 void vTaskResume( TaskHandle_t xTaskToResume ) PRIVILEGED_FUNCTION;
1192 * void xTaskResumeFromISR( TaskHandle_t xTaskToResume );
1195 * INCLUDE_xTaskResumeFromISR must be defined as 1 for this function to be
1196 * available. See the configuration section for more information.
1198 * An implementation of vTaskResume() that can be called from within an ISR.
1200 * A task that has been suspended by one or more calls to vTaskSuspend ()
1201 * will be made available for running again by a single call to
1202 * xTaskResumeFromISR ().
1204 * xTaskResumeFromISR() should not be used to synchronise a task with an
1205 * interrupt if there is a chance that the interrupt could arrive prior to the
1206 * task being suspended - as this can lead to interrupts being missed. Use of a
1207 * semaphore as a synchronisation mechanism would avoid this eventuality.
1209 * @param xTaskToResume Handle to the task being readied.
1211 * @return pdTRUE if resuming the task should result in a context switch,
1212 * otherwise pdFALSE. This is used by the ISR to determine if a context switch
1213 * may be required following the ISR.
1215 * \defgroup vTaskResumeFromISR vTaskResumeFromISR
1218 BaseType_t xTaskResumeFromISR( TaskHandle_t xTaskToResume ) PRIVILEGED_FUNCTION;
1220 /*-----------------------------------------------------------
1222 *----------------------------------------------------------*/
1227 * void vTaskStartScheduler( void );
1230 * Starts the real time kernel tick processing. After calling the kernel
1231 * has control over which tasks are executed and when.
1233 * See the demo application file main.c for an example of creating
1234 * tasks and starting the kernel.
1238 * void vAFunction( void )
1240 * // Create at least one task before starting the kernel.
1241 * xTaskCreate( vTaskCode, "NAME", STACK_SIZE, NULL, tskIDLE_PRIORITY, NULL );
1243 * // Start the real time kernel with preemption.
1244 * vTaskStartScheduler ();
1246 * // Will not get here unless a task calls vTaskEndScheduler ()
1250 * \defgroup vTaskStartScheduler vTaskStartScheduler
1251 * \ingroup SchedulerControl
1253 void vTaskStartScheduler( void ) PRIVILEGED_FUNCTION;
1258 * void vTaskEndScheduler( void );
1261 * NOTE: At the time of writing only the x86 real mode port, which runs on a PC
1262 * in place of DOS, implements this function.
1264 * Stops the real time kernel tick. All created tasks will be automatically
1265 * deleted and multitasking (either preemptive or cooperative) will
1266 * stop. Execution then resumes from the point where vTaskStartScheduler ()
1267 * was called, as if vTaskStartScheduler () had just returned.
1269 * See the demo application file main. c in the demo/PC directory for an
1270 * example that uses vTaskEndScheduler ().
1272 * vTaskEndScheduler () requires an exit function to be defined within the
1273 * portable layer (see vPortEndScheduler () in port. c for the PC port). This
1274 * performs hardware specific operations such as stopping the kernel tick.
1276 * vTaskEndScheduler () will cause all of the resources allocated by the
1277 * kernel to be freed - but will not free resources allocated by application
1282 * void vTaskCode( void * pvParameters )
1286 * // Task code goes here.
1288 * // At some point we want to end the real time kernel processing
1290 * vTaskEndScheduler ();
1294 * void vAFunction( void )
1296 * // Create at least one task before starting the kernel.
1297 * xTaskCreate( vTaskCode, "NAME", STACK_SIZE, NULL, tskIDLE_PRIORITY, NULL );
1299 * // Start the real time kernel with preemption.
1300 * vTaskStartScheduler ();
1302 * // Will only get here when the vTaskCode () task has called
1303 * // vTaskEndScheduler (). When we get here we are back to single task
1308 * \defgroup vTaskEndScheduler vTaskEndScheduler
1309 * \ingroup SchedulerControl
1311 void vTaskEndScheduler( void ) PRIVILEGED_FUNCTION;
1316 * void vTaskSuspendAll( void );
1319 * Suspends the scheduler without disabling interrupts. Context switches will
1320 * not occur while the scheduler is suspended.
1322 * After calling vTaskSuspendAll () the calling task will continue to execute
1323 * without risk of being swapped out until a call to xTaskResumeAll () has been
1326 * API functions that have the potential to cause a context switch (for example,
1327 * xTaskDelayUntil(), xQueueSend(), etc.) must not be called while the scheduler
1332 * void vTask1( void * pvParameters )
1336 * // Task code goes here.
1340 * // At some point the task wants to perform a long operation during
1341 * // which it does not want to get swapped out. It cannot use
1342 * // taskENTER_CRITICAL ()/taskEXIT_CRITICAL () as the length of the
1343 * // operation may cause interrupts to be missed - including the
1346 * // Prevent the real time kernel swapping out the task.
1347 * vTaskSuspendAll ();
1349 * // Perform the operation here. There is no need to use critical
1350 * // sections as we have all the microcontroller processing time.
1351 * // During this time interrupts will still operate and the kernel
1352 * // tick count will be maintained.
1356 * // The operation is complete. Restart the kernel.
1357 * xTaskResumeAll ();
1361 * \defgroup vTaskSuspendAll vTaskSuspendAll
1362 * \ingroup SchedulerControl
1364 void vTaskSuspendAll( void ) PRIVILEGED_FUNCTION;
1369 * BaseType_t xTaskResumeAll( void );
1372 * Resumes scheduler activity after it was suspended by a call to
1373 * vTaskSuspendAll().
1375 * xTaskResumeAll() only resumes the scheduler. It does not unsuspend tasks
1376 * that were previously suspended by a call to vTaskSuspend().
1378 * @return If resuming the scheduler caused a context switch then pdTRUE is
1379 * returned, otherwise pdFALSE is returned.
1383 * void vTask1( void * pvParameters )
1387 * // Task code goes here.
1391 * // At some point the task wants to perform a long operation during
1392 * // which it does not want to get swapped out. It cannot use
1393 * // taskENTER_CRITICAL ()/taskEXIT_CRITICAL () as the length of the
1394 * // operation may cause interrupts to be missed - including the
1397 * // Prevent the real time kernel swapping out the task.
1398 * vTaskSuspendAll ();
1400 * // Perform the operation here. There is no need to use critical
1401 * // sections as we have all the microcontroller processing time.
1402 * // During this time interrupts will still operate and the real
1403 * // time kernel tick count will be maintained.
1407 * // The operation is complete. Restart the kernel. We want to force
1408 * // a context switch - but there is no point if resuming the scheduler
1409 * // caused a context switch already.
1410 * if( !xTaskResumeAll () )
1417 * \defgroup xTaskResumeAll xTaskResumeAll
1418 * \ingroup SchedulerControl
1420 BaseType_t xTaskResumeAll( void ) PRIVILEGED_FUNCTION;
1422 /*-----------------------------------------------------------
1424 *----------------------------------------------------------*/
1428 * <PRE>TickType_t xTaskGetTickCount( void );</PRE>
1430 * @return The count of ticks since vTaskStartScheduler was called.
1432 * \defgroup xTaskGetTickCount xTaskGetTickCount
1433 * \ingroup TaskUtils
1435 TickType_t xTaskGetTickCount( void ) PRIVILEGED_FUNCTION;
1439 * <PRE>TickType_t xTaskGetTickCountFromISR( void );</PRE>
1441 * @return The count of ticks since vTaskStartScheduler was called.
1443 * This is a version of xTaskGetTickCount() that is safe to be called from an
1444 * ISR - provided that TickType_t is the natural word size of the
1445 * microcontroller being used or interrupt nesting is either not supported or
1448 * \defgroup xTaskGetTickCountFromISR xTaskGetTickCountFromISR
1449 * \ingroup TaskUtils
1451 TickType_t xTaskGetTickCountFromISR( void ) PRIVILEGED_FUNCTION;
1455 * <PRE>uint16_t uxTaskGetNumberOfTasks( void );</PRE>
1457 * @return The number of tasks that the real time kernel is currently managing.
1458 * This includes all ready, blocked and suspended tasks. A task that
1459 * has been deleted but not yet freed by the idle task will also be
1460 * included in the count.
1462 * \defgroup uxTaskGetNumberOfTasks uxTaskGetNumberOfTasks
1463 * \ingroup TaskUtils
1465 UBaseType_t uxTaskGetNumberOfTasks( void ) PRIVILEGED_FUNCTION;
1469 * <PRE>char *pcTaskGetName( TaskHandle_t xTaskToQuery );</PRE>
1471 * @return The text (human readable) name of the task referenced by the handle
1472 * xTaskToQuery. A task can query its own name by either passing in its own
1473 * handle, or by setting xTaskToQuery to NULL.
1475 * \defgroup pcTaskGetName pcTaskGetName
1476 * \ingroup TaskUtils
1478 char * pcTaskGetName( TaskHandle_t xTaskToQuery ) PRIVILEGED_FUNCTION; /*lint !e971 Unqualified char types are allowed for strings and single characters only. */
1482 * <PRE>TaskHandle_t xTaskGetHandle( const char *pcNameToQuery );</PRE>
1484 * NOTE: This function takes a relatively long time to complete and should be
1487 * @return The handle of the task that has the human readable name pcNameToQuery.
1488 * NULL is returned if no matching name is found. INCLUDE_xTaskGetHandle
1489 * must be set to 1 in FreeRTOSConfig.h for pcTaskGetHandle() to be available.
1491 * \defgroup pcTaskGetHandle pcTaskGetHandle
1492 * \ingroup TaskUtils
1494 TaskHandle_t xTaskGetHandle( const char * pcNameToQuery ) PRIVILEGED_FUNCTION; /*lint !e971 Unqualified char types are allowed for strings and single characters only. */
1498 * <PRE>UBaseType_t uxTaskGetStackHighWaterMark( TaskHandle_t xTask );</PRE>
1500 * INCLUDE_uxTaskGetStackHighWaterMark must be set to 1 in FreeRTOSConfig.h for
1501 * this function to be available.
1503 * Returns the high water mark of the stack associated with xTask. That is,
1504 * the minimum free stack space there has been (in words, so on a 32 bit machine
1505 * a value of 1 means 4 bytes) since the task started. The smaller the returned
1506 * number the closer the task has come to overflowing its stack.
1508 * uxTaskGetStackHighWaterMark() and uxTaskGetStackHighWaterMark2() are the
1509 * same except for their return type. Using configSTACK_DEPTH_TYPE allows the
1510 * user to determine the return type. It gets around the problem of the value
1511 * overflowing on 8-bit types without breaking backward compatibility for
1512 * applications that expect an 8-bit return type.
1514 * @param xTask Handle of the task associated with the stack to be checked.
1515 * Set xTask to NULL to check the stack of the calling task.
1517 * @return The smallest amount of free stack space there has been (in words, so
1518 * actual spaces on the stack rather than bytes) since the task referenced by
1519 * xTask was created.
1521 UBaseType_t uxTaskGetStackHighWaterMark( TaskHandle_t xTask ) PRIVILEGED_FUNCTION;
1525 * <PRE>configSTACK_DEPTH_TYPE uxTaskGetStackHighWaterMark2( TaskHandle_t xTask );</PRE>
1527 * INCLUDE_uxTaskGetStackHighWaterMark2 must be set to 1 in FreeRTOSConfig.h for
1528 * this function to be available.
1530 * Returns the high water mark of the stack associated with xTask. That is,
1531 * the minimum free stack space there has been (in words, so on a 32 bit machine
1532 * a value of 1 means 4 bytes) since the task started. The smaller the returned
1533 * number the closer the task has come to overflowing its stack.
1535 * uxTaskGetStackHighWaterMark() and uxTaskGetStackHighWaterMark2() are the
1536 * same except for their return type. Using configSTACK_DEPTH_TYPE allows the
1537 * user to determine the return type. It gets around the problem of the value
1538 * overflowing on 8-bit types without breaking backward compatibility for
1539 * applications that expect an 8-bit return type.
1541 * @param xTask Handle of the task associated with the stack to be checked.
1542 * Set xTask to NULL to check the stack of the calling task.
1544 * @return The smallest amount of free stack space there has been (in words, so
1545 * actual spaces on the stack rather than bytes) since the task referenced by
1546 * xTask was created.
1548 configSTACK_DEPTH_TYPE uxTaskGetStackHighWaterMark2( TaskHandle_t xTask ) PRIVILEGED_FUNCTION;
1550 /* When using trace macros it is sometimes necessary to include task.h before
1551 * FreeRTOS.h. When this is done TaskHookFunction_t will not yet have been defined,
1552 * so the following two prototypes will cause a compilation error. This can be
1553 * fixed by simply guarding against the inclusion of these two prototypes unless
1554 * they are explicitly required by the configUSE_APPLICATION_TASK_TAG configuration
1556 #ifdef configUSE_APPLICATION_TASK_TAG
1557 #if configUSE_APPLICATION_TASK_TAG == 1
1562 * void vTaskSetApplicationTaskTag( TaskHandle_t xTask, TaskHookFunction_t pxHookFunction );
1565 * Sets pxHookFunction to be the task hook function used by the task xTask.
1566 * Passing xTask as NULL has the effect of setting the calling tasks hook
1569 void vTaskSetApplicationTaskTag( TaskHandle_t xTask,
1570 TaskHookFunction_t pxHookFunction ) PRIVILEGED_FUNCTION;
1575 * void xTaskGetApplicationTaskTag( TaskHandle_t xTask );
1578 * Returns the pxHookFunction value assigned to the task xTask. Do not
1579 * call from an interrupt service routine - call
1580 * xTaskGetApplicationTaskTagFromISR() instead.
1582 TaskHookFunction_t xTaskGetApplicationTaskTag( TaskHandle_t xTask ) PRIVILEGED_FUNCTION;
1587 * void xTaskGetApplicationTaskTagFromISR( TaskHandle_t xTask );
1590 * Returns the pxHookFunction value assigned to the task xTask. Can
1591 * be called from an interrupt service routine.
1593 TaskHookFunction_t xTaskGetApplicationTaskTagFromISR( TaskHandle_t xTask ) PRIVILEGED_FUNCTION;
1594 #endif /* configUSE_APPLICATION_TASK_TAG ==1 */
1595 #endif /* ifdef configUSE_APPLICATION_TASK_TAG */
1597 #if ( configNUM_THREAD_LOCAL_STORAGE_POINTERS > 0 )
1599 /* Each task contains an array of pointers that is dimensioned by the
1600 * configNUM_THREAD_LOCAL_STORAGE_POINTERS setting in FreeRTOSConfig.h. The
1601 * kernel does not use the pointers itself, so the application writer can use
1602 * the pointers for any purpose they wish. The following two functions are
1603 * used to set and query a pointer respectively. */
1604 void vTaskSetThreadLocalStoragePointer( TaskHandle_t xTaskToSet,
1606 void * pvValue ) PRIVILEGED_FUNCTION;
1607 void * pvTaskGetThreadLocalStoragePointer( TaskHandle_t xTaskToQuery,
1608 BaseType_t xIndex ) PRIVILEGED_FUNCTION;
1612 #if ( configCHECK_FOR_STACK_OVERFLOW > 0 )
1616 * <pre>void vApplicationStackOverflowHook( TaskHandle_t xTask char *pcTaskName); </pre>
1618 * The application stack overflow hook is called when a stack overflow is detected for a task.
1620 * Details on stack overflow detection can be found here: https://www.FreeRTOS.org/Stacks-and-stack-overflow-checking.html
1622 * @param xTask the task that just exceeded its stack boundaries.
1623 * @param pcTaskName A character string containing the name of the offending task.
1625 void vApplicationStackOverflowHook( TaskHandle_t xTask,
1626 char * pcTaskName );
1630 #if ( configUSE_TICK_HOOK > 0 )
1634 * <pre>void vApplicationTickHook( void ); </pre>
1636 * This hook function is called in the system tick handler after any OS work is completed.
1638 void vApplicationTickHook( void ); /*lint !e526 Symbol not defined as it is an application callback. */
1642 #if ( configSUPPORT_STATIC_ALLOCATION == 1 )
1646 * <pre>void vApplicationGetIdleTaskMemory( StaticTask_t ** ppxIdleTaskTCBBuffer, StackType_t ** ppxIdleTaskStackBuffer, uint32_t *pulIdleTaskStackSize ) </pre>
1648 * 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
1649 * configSUPPORT_STATIC_ALLOCATION is set. For more information see this URI: https://www.FreeRTOS.org/a00110.html#configSUPPORT_STATIC_ALLOCATION
1651 * @param ppxIdleTaskTCBBuffer A handle to a statically allocated TCB buffer
1652 * @param ppxIdleTaskStackBuffer A handle to a statically allocated Stack buffer for the idle task
1653 * @param pulIdleTaskStackSize A pointer to the number of elements that will fit in the allocated stack buffer
1655 void vApplicationGetIdleTaskMemory( StaticTask_t ** ppxIdleTaskTCBBuffer,
1656 StackType_t ** ppxIdleTaskStackBuffer,
1657 uint32_t * pulIdleTaskStackSize ); /*lint !e526 Symbol not defined as it is an application callback. */
1663 * BaseType_t xTaskCallApplicationTaskHook( TaskHandle_t xTask, void *pvParameter );
1666 * Calls the hook function associated with xTask. Passing xTask as NULL has
1667 * the effect of calling the Running tasks (the calling task) hook function.
1669 * pvParameter is passed to the hook function for the task to interpret as it
1670 * wants. The return value is the value returned by the task hook function
1671 * registered by the user.
1673 BaseType_t xTaskCallApplicationTaskHook( TaskHandle_t xTask,
1674 void * pvParameter ) PRIVILEGED_FUNCTION;
1677 * xTaskGetIdleTaskHandle() is only available if
1678 * INCLUDE_xTaskGetIdleTaskHandle is set to 1 in FreeRTOSConfig.h.
1680 * Simply returns the handle of the idle task. It is not valid to call
1681 * xTaskGetIdleTaskHandle() before the scheduler has been started.
1683 TaskHandle_t xTaskGetIdleTaskHandle( void ) PRIVILEGED_FUNCTION;
1686 * configUSE_TRACE_FACILITY must be defined as 1 in FreeRTOSConfig.h for
1687 * uxTaskGetSystemState() to be available.
1689 * uxTaskGetSystemState() populates an TaskStatus_t structure for each task in
1690 * the system. TaskStatus_t structures contain, among other things, members
1691 * for the task handle, task name, task priority, task state, and total amount
1692 * of run time consumed by the task. See the TaskStatus_t structure
1693 * definition in this file for the full member list.
1695 * NOTE: This function is intended for debugging use only as its use results in
1696 * the scheduler remaining suspended for an extended period.
1698 * @param pxTaskStatusArray A pointer to an array of TaskStatus_t structures.
1699 * The array must contain at least one TaskStatus_t structure for each task
1700 * that is under the control of the RTOS. The number of tasks under the control
1701 * of the RTOS can be determined using the uxTaskGetNumberOfTasks() API function.
1703 * @param uxArraySize The size of the array pointed to by the pxTaskStatusArray
1704 * parameter. The size is specified as the number of indexes in the array, or
1705 * the number of TaskStatus_t structures contained in the array, not by the
1706 * number of bytes in the array.
1708 * @param pulTotalRunTime If configGENERATE_RUN_TIME_STATS is set to 1 in
1709 * FreeRTOSConfig.h then *pulTotalRunTime is set by uxTaskGetSystemState() to the
1710 * total run time (as defined by the run time stats clock, see
1711 * https://www.FreeRTOS.org/rtos-run-time-stats.html) since the target booted.
1712 * pulTotalRunTime can be set to NULL to omit the total run time information.
1714 * @return The number of TaskStatus_t structures that were populated by
1715 * uxTaskGetSystemState(). This should equal the number returned by the
1716 * uxTaskGetNumberOfTasks() API function, but will be zero if the value passed
1717 * in the uxArraySize parameter was too small.
1721 * // This example demonstrates how a human readable table of run time stats
1722 * // information is generated from raw data provided by uxTaskGetSystemState().
1723 * // The human readable table is written to pcWriteBuffer
1724 * void vTaskGetRunTimeStats( char *pcWriteBuffer )
1726 * TaskStatus_t *pxTaskStatusArray;
1727 * volatile UBaseType_t uxArraySize, x;
1728 * configRUN_TIME_COUNTER_TYPE ulTotalRunTime, ulStatsAsPercentage;
1730 * // Make sure the write buffer does not contain a string.
1731 * pcWriteBuffer = 0x00;
1733 * // Take a snapshot of the number of tasks in case it changes while this
1734 * // function is executing.
1735 * uxArraySize = uxTaskGetNumberOfTasks();
1737 * // Allocate a TaskStatus_t structure for each task. An array could be
1738 * // allocated statically at compile time.
1739 * pxTaskStatusArray = pvPortMalloc( uxArraySize * sizeof( TaskStatus_t ) );
1741 * if( pxTaskStatusArray != NULL )
1743 * // Generate raw status information about each task.
1744 * uxArraySize = uxTaskGetSystemState( pxTaskStatusArray, uxArraySize, &ulTotalRunTime );
1746 * // For percentage calculations.
1747 * ulTotalRunTime /= 100UL;
1749 * // Avoid divide by zero errors.
1750 * if( ulTotalRunTime > 0 )
1752 * // For each populated position in the pxTaskStatusArray array,
1753 * // format the raw data as human readable ASCII data
1754 * for( x = 0; x < uxArraySize; x++ )
1756 * // What percentage of the total run time has the task used?
1757 * // This will always be rounded down to the nearest integer.
1758 * // ulTotalRunTimeDiv100 has already been divided by 100.
1759 * ulStatsAsPercentage = pxTaskStatusArray[ x ].ulRunTimeCounter / ulTotalRunTime;
1761 * if( ulStatsAsPercentage > 0UL )
1763 * sprintf( pcWriteBuffer, "%s\t\t%lu\t\t%lu%%\r\n", pxTaskStatusArray[ x ].pcTaskName, pxTaskStatusArray[ x ].ulRunTimeCounter, ulStatsAsPercentage );
1767 * // If the percentage is zero here then the task has
1768 * // consumed less than 1% of the total run time.
1769 * sprintf( pcWriteBuffer, "%s\t\t%lu\t\t<1%%\r\n", pxTaskStatusArray[ x ].pcTaskName, pxTaskStatusArray[ x ].ulRunTimeCounter );
1772 * pcWriteBuffer += strlen( ( char * ) pcWriteBuffer );
1776 * // The array is no longer needed, free the memory it consumes.
1777 * vPortFree( pxTaskStatusArray );
1782 UBaseType_t uxTaskGetSystemState( TaskStatus_t * const pxTaskStatusArray,
1783 const UBaseType_t uxArraySize,
1784 configRUN_TIME_COUNTER_TYPE * const pulTotalRunTime ) PRIVILEGED_FUNCTION;
1788 * <PRE>void vTaskList( char *pcWriteBuffer );</PRE>
1790 * configUSE_TRACE_FACILITY and configUSE_STATS_FORMATTING_FUNCTIONS must
1791 * both be defined as 1 for this function to be available. See the
1792 * configuration section of the FreeRTOS.org website for more information.
1794 * NOTE 1: This function will disable interrupts for its duration. It is
1795 * not intended for normal application runtime use but as a debug aid.
1797 * Lists all the current tasks, along with their current state and stack
1798 * usage high water mark.
1800 * Tasks are reported as blocked ('B'), ready ('R'), deleted ('D') or
1805 * This function is provided for convenience only, and is used by many of the
1806 * demo applications. Do not consider it to be part of the scheduler.
1808 * vTaskList() calls uxTaskGetSystemState(), then formats part of the
1809 * uxTaskGetSystemState() output into a human readable table that displays task:
1810 * names, states, priority, stack usage and task number.
1811 * Stack usage specified as the number of unused StackType_t words stack can hold
1812 * on top of stack - not the number of bytes.
1814 * vTaskList() has a dependency on the sprintf() C library function that might
1815 * bloat the code size, use a lot of stack, and provide different results on
1816 * different platforms. An alternative, tiny, third party, and limited
1817 * functionality implementation of sprintf() is provided in many of the
1818 * FreeRTOS/Demo sub-directories in a file called printf-stdarg.c (note
1819 * printf-stdarg.c does not provide a full snprintf() implementation!).
1821 * It is recommended that production systems call uxTaskGetSystemState()
1822 * directly to get access to raw stats data, rather than indirectly through a
1823 * call to vTaskList().
1825 * @param pcWriteBuffer A buffer into which the above mentioned details
1826 * will be written, in ASCII form. This buffer is assumed to be large
1827 * enough to contain the generated report. Approximately 40 bytes per
1828 * task should be sufficient.
1830 * \defgroup vTaskList vTaskList
1831 * \ingroup TaskUtils
1833 void vTaskList( char * pcWriteBuffer ) PRIVILEGED_FUNCTION; /*lint !e971 Unqualified char types are allowed for strings and single characters only. */
1837 * <PRE>void vTaskGetRunTimeStats( char *pcWriteBuffer );</PRE>
1839 * configGENERATE_RUN_TIME_STATS and configUSE_STATS_FORMATTING_FUNCTIONS
1840 * must both be defined as 1 for this function to be available. The application
1841 * must also then provide definitions for
1842 * portCONFIGURE_TIMER_FOR_RUN_TIME_STATS() and portGET_RUN_TIME_COUNTER_VALUE()
1843 * to configure a peripheral timer/counter and return the timers current count
1844 * value respectively. The counter should be at least 10 times the frequency of
1847 * NOTE 1: This function will disable interrupts for its duration. It is
1848 * not intended for normal application runtime use but as a debug aid.
1850 * Setting configGENERATE_RUN_TIME_STATS to 1 will result in a total
1851 * accumulated execution time being stored for each task. The resolution
1852 * of the accumulated time value depends on the frequency of the timer
1853 * configured by the portCONFIGURE_TIMER_FOR_RUN_TIME_STATS() macro.
1854 * Calling vTaskGetRunTimeStats() writes the total execution time of each
1855 * task into a buffer, both as an absolute count value and as a percentage
1856 * of the total system execution time.
1860 * This function is provided for convenience only, and is used by many of the
1861 * demo applications. Do not consider it to be part of the scheduler.
1863 * vTaskGetRunTimeStats() calls uxTaskGetSystemState(), then formats part of the
1864 * uxTaskGetSystemState() output into a human readable table that displays the
1865 * amount of time each task has spent in the Running state in both absolute and
1868 * vTaskGetRunTimeStats() has a dependency on the sprintf() C library function
1869 * that might bloat the code size, use a lot of stack, and provide different
1870 * results on different platforms. An alternative, tiny, third party, and
1871 * limited functionality implementation of sprintf() is provided in many of the
1872 * FreeRTOS/Demo sub-directories in a file called printf-stdarg.c (note
1873 * printf-stdarg.c does not provide a full snprintf() implementation!).
1875 * It is recommended that production systems call uxTaskGetSystemState() directly
1876 * to get access to raw stats data, rather than indirectly through a call to
1877 * vTaskGetRunTimeStats().
1879 * @param pcWriteBuffer A buffer into which the execution times will be
1880 * written, in ASCII form. This buffer is assumed to be large enough to
1881 * contain the generated report. Approximately 40 bytes per task should
1884 * \defgroup vTaskGetRunTimeStats vTaskGetRunTimeStats
1885 * \ingroup TaskUtils
1887 void vTaskGetRunTimeStats( char * pcWriteBuffer ) PRIVILEGED_FUNCTION; /*lint !e971 Unqualified char types are allowed for strings and single characters only. */
1891 * <PRE>configRUN_TIME_COUNTER_TYPE ulTaskGetIdleRunTimeCounter( void );</PRE>
1892 * <PRE>configRUN_TIME_COUNTER_TYPE ulTaskGetIdleRunTimePercent( void );</PRE>
1894 * configGENERATE_RUN_TIME_STATS, configUSE_STATS_FORMATTING_FUNCTIONS and
1895 * INCLUDE_xTaskGetIdleTaskHandle must all be defined as 1 for these functions
1896 * to be available. The application must also then provide definitions for
1897 * portCONFIGURE_TIMER_FOR_RUN_TIME_STATS() and portGET_RUN_TIME_COUNTER_VALUE()
1898 * to configure a peripheral timer/counter and return the timers current count
1899 * value respectively. The counter should be at least 10 times the frequency of
1902 * Setting configGENERATE_RUN_TIME_STATS to 1 will result in a total
1903 * accumulated execution time being stored for each task. The resolution
1904 * of the accumulated time value depends on the frequency of the timer
1905 * configured by the portCONFIGURE_TIMER_FOR_RUN_TIME_STATS() macro.
1906 * While uxTaskGetSystemState() and vTaskGetRunTimeStats() writes the total
1907 * execution time of each task into a buffer, ulTaskGetIdleRunTimeCounter()
1908 * returns the total execution time of just the idle task and
1909 * ulTaskGetIdleRunTimePercent() returns the percentage of the CPU time used by
1910 * just the idle task.
1912 * Note the amount of idle time is only a good measure of the slack time in a
1913 * system if there are no other tasks executing at the idle priority, tickless
1914 * idle is not used, and configIDLE_SHOULD_YIELD is set to 0.
1916 * @return The total run time of the idle task or the percentage of the total
1917 * run time consumed by the idle task. This is the amount of time the
1918 * idle task has actually been executing. The unit of time is dependent on the
1919 * frequency configured using the portCONFIGURE_TIMER_FOR_RUN_TIME_STATS() and
1920 * portGET_RUN_TIME_COUNTER_VALUE() macros.
1922 * \defgroup ulTaskGetIdleRunTimeCounter ulTaskGetIdleRunTimeCounter
1923 * \ingroup TaskUtils
1925 configRUN_TIME_COUNTER_TYPE ulTaskGetIdleRunTimeCounter( void ) PRIVILEGED_FUNCTION;
1926 configRUN_TIME_COUNTER_TYPE ulTaskGetIdleRunTimePercent( void ) PRIVILEGED_FUNCTION;
1930 * <PRE>BaseType_t xTaskNotifyIndexed( TaskHandle_t xTaskToNotify, UBaseType_t uxIndexToNotify, uint32_t ulValue, eNotifyAction eAction );</PRE>
1931 * <PRE>BaseType_t xTaskNotify( TaskHandle_t xTaskToNotify, uint32_t ulValue, eNotifyAction eAction );</PRE>
1933 * See https://www.FreeRTOS.org/RTOS-task-notifications.html for details.
1935 * configUSE_TASK_NOTIFICATIONS must be undefined or defined as 1 for these
1936 * functions to be available.
1938 * Sends a direct to task notification to a task, with an optional value and
1941 * Each task has a private array of "notification values" (or 'notifications'),
1942 * each of which is a 32-bit unsigned integer (uint32_t). The constant
1943 * configTASK_NOTIFICATION_ARRAY_ENTRIES sets the number of indexes in the
1944 * array, and (for backward compatibility) defaults to 1 if left undefined.
1945 * Prior to FreeRTOS V10.4.0 there was only one notification value per task.
1947 * Events can be sent to a task using an intermediary object. Examples of such
1948 * objects are queues, semaphores, mutexes and event groups. Task notifications
1949 * are a method of sending an event directly to a task without the need for such
1950 * an intermediary object.
1952 * A notification sent to a task can optionally perform an action, such as
1953 * update, overwrite or increment one of the task's notification values. In
1954 * that way task notifications can be used to send data to a task, or be used as
1955 * light weight and fast binary or counting semaphores.
1957 * A task can use xTaskNotifyWaitIndexed() or ulTaskNotifyTakeIndexed() to
1958 * [optionally] block to wait for a notification to be pending. The task does
1959 * not consume any CPU time while it is in the Blocked state.
1961 * A notification sent to a task will remain pending until it is cleared by the
1962 * task calling xTaskNotifyWaitIndexed() or ulTaskNotifyTakeIndexed() (or their
1963 * un-indexed equivalents). If the task was already in the Blocked state to
1964 * wait for a notification when the notification arrives then the task will
1965 * automatically be removed from the Blocked state (unblocked) and the
1966 * notification cleared.
1968 * **NOTE** Each notification within the array operates independently - a task
1969 * can only block on one notification within the array at a time and will not be
1970 * unblocked by a notification sent to any other array index.
1972 * Backward compatibility information:
1973 * Prior to FreeRTOS V10.4.0 each task had a single "notification value", and
1974 * all task notification API functions operated on that value. Replacing the
1975 * single notification value with an array of notification values necessitated a
1976 * new set of API functions that could address specific notifications within the
1977 * array. xTaskNotify() is the original API function, and remains backward
1978 * compatible by always operating on the notification value at index 0 in the
1979 * array. Calling xTaskNotify() is equivalent to calling xTaskNotifyIndexed()
1980 * with the uxIndexToNotify parameter set to 0.
1982 * @param xTaskToNotify The handle of the task being notified. The handle to a
1983 * task can be returned from the xTaskCreate() API function used to create the
1984 * task, and the handle of the currently running task can be obtained by calling
1985 * xTaskGetCurrentTaskHandle().
1987 * @param uxIndexToNotify The index within the target task's array of
1988 * notification values to which the notification is to be sent. uxIndexToNotify
1989 * must be less than configTASK_NOTIFICATION_ARRAY_ENTRIES. xTaskNotify() does
1990 * not have this parameter and always sends notifications to index 0.
1992 * @param ulValue Data that can be sent with the notification. How the data is
1993 * used depends on the value of the eAction parameter.
1995 * @param eAction Specifies how the notification updates the task's notification
1996 * value, if at all. Valid values for eAction are as follows:
1999 * The target notification value is bitwise ORed with ulValue.
2000 * xTaskNotifyIndexed() always returns pdPASS in this case.
2003 * The target notification value is incremented. ulValue is not used and
2004 * xTaskNotifyIndexed() always returns pdPASS in this case.
2006 * eSetValueWithOverwrite -
2007 * The target notification value is set to the value of ulValue, even if the
2008 * task being notified had not yet processed the previous notification at the
2009 * same array index (the task already had a notification pending at that index).
2010 * xTaskNotifyIndexed() always returns pdPASS in this case.
2012 * eSetValueWithoutOverwrite -
2013 * If the task being notified did not already have a notification pending at the
2014 * same array index then the target notification value is set to ulValue and
2015 * xTaskNotifyIndexed() will return pdPASS. If the task being notified already
2016 * had a notification pending at the same array index then no action is
2017 * performed and pdFAIL is returned.
2020 * The task receives a notification at the specified array index without the
2021 * notification value at that index being updated. ulValue is not used and
2022 * xTaskNotifyIndexed() always returns pdPASS in this case.
2024 * pulPreviousNotificationValue -
2025 * Can be used to pass out the subject task's notification value before any
2026 * bits are modified by the notify function.
2028 * @return Dependent on the value of eAction. See the description of the
2029 * eAction parameter.
2031 * \defgroup xTaskNotifyIndexed xTaskNotifyIndexed
2032 * \ingroup TaskNotifications
2034 BaseType_t xTaskGenericNotify( TaskHandle_t xTaskToNotify,
2035 UBaseType_t uxIndexToNotify,
2037 eNotifyAction eAction,
2038 uint32_t * pulPreviousNotificationValue ) PRIVILEGED_FUNCTION;
2039 #define xTaskNotify( xTaskToNotify, ulValue, eAction ) \
2040 xTaskGenericNotify( ( xTaskToNotify ), ( tskDEFAULT_INDEX_TO_NOTIFY ), ( ulValue ), ( eAction ), NULL )
2041 #define xTaskNotifyIndexed( xTaskToNotify, uxIndexToNotify, ulValue, eAction ) \
2042 xTaskGenericNotify( ( xTaskToNotify ), ( uxIndexToNotify ), ( ulValue ), ( eAction ), NULL )
2046 * <PRE>BaseType_t xTaskNotifyAndQueryIndexed( TaskHandle_t xTaskToNotify, UBaseType_t uxIndexToNotify, uint32_t ulValue, eNotifyAction eAction, uint32_t *pulPreviousNotifyValue );</PRE>
2047 * <PRE>BaseType_t xTaskNotifyAndQuery( TaskHandle_t xTaskToNotify, uint32_t ulValue, eNotifyAction eAction, uint32_t *pulPreviousNotifyValue );</PRE>
2049 * See https://www.FreeRTOS.org/RTOS-task-notifications.html for details.
2051 * xTaskNotifyAndQueryIndexed() performs the same operation as
2052 * xTaskNotifyIndexed() with the addition that it also returns the subject
2053 * task's prior notification value (the notification value at the time the
2054 * function is called rather than when the function returns) in the additional
2055 * pulPreviousNotifyValue parameter.
2057 * xTaskNotifyAndQuery() performs the same operation as xTaskNotify() with the
2058 * addition that it also returns the subject task's prior notification value
2059 * (the notification value as it was at the time the function is called, rather
2060 * than when the function returns) in the additional pulPreviousNotifyValue
2063 * \defgroup xTaskNotifyAndQueryIndexed xTaskNotifyAndQueryIndexed
2064 * \ingroup TaskNotifications
2066 #define xTaskNotifyAndQuery( xTaskToNotify, ulValue, eAction, pulPreviousNotifyValue ) \
2067 xTaskGenericNotify( ( xTaskToNotify ), ( tskDEFAULT_INDEX_TO_NOTIFY ), ( ulValue ), ( eAction ), ( pulPreviousNotifyValue ) )
2068 #define xTaskNotifyAndQueryIndexed( xTaskToNotify, uxIndexToNotify, ulValue, eAction, pulPreviousNotifyValue ) \
2069 xTaskGenericNotify( ( xTaskToNotify ), ( uxIndexToNotify ), ( ulValue ), ( eAction ), ( pulPreviousNotifyValue ) )
2073 * <PRE>BaseType_t xTaskNotifyIndexedFromISR( TaskHandle_t xTaskToNotify, UBaseType_t uxIndexToNotify, uint32_t ulValue, eNotifyAction eAction, BaseType_t *pxHigherPriorityTaskWoken );</PRE>
2074 * <PRE>BaseType_t xTaskNotifyFromISR( TaskHandle_t xTaskToNotify, uint32_t ulValue, eNotifyAction eAction, BaseType_t *pxHigherPriorityTaskWoken );</PRE>
2076 * See https://www.FreeRTOS.org/RTOS-task-notifications.html for details.
2078 * configUSE_TASK_NOTIFICATIONS must be undefined or defined as 1 for these
2079 * functions to be available.
2081 * A version of xTaskNotifyIndexed() that can be used from an interrupt service
2084 * Each task has a private array of "notification values" (or 'notifications'),
2085 * each of which is a 32-bit unsigned integer (uint32_t). The constant
2086 * configTASK_NOTIFICATION_ARRAY_ENTRIES sets the number of indexes in the
2087 * array, and (for backward compatibility) defaults to 1 if left undefined.
2088 * Prior to FreeRTOS V10.4.0 there was only one notification value per task.
2090 * Events can be sent to a task using an intermediary object. Examples of such
2091 * objects are queues, semaphores, mutexes and event groups. Task notifications
2092 * are a method of sending an event directly to a task without the need for such
2093 * an intermediary object.
2095 * A notification sent to a task can optionally perform an action, such as
2096 * update, overwrite or increment one of the task's notification values. In
2097 * that way task notifications can be used to send data to a task, or be used as
2098 * light weight and fast binary or counting semaphores.
2100 * A task can use xTaskNotifyWaitIndexed() to [optionally] block to wait for a
2101 * notification to be pending, or ulTaskNotifyTakeIndexed() to [optionally] block
2102 * to wait for a notification value to have a non-zero value. The task does
2103 * not consume any CPU time while it is in the Blocked state.
2105 * A notification sent to a task will remain pending until it is cleared by the
2106 * task calling xTaskNotifyWaitIndexed() or ulTaskNotifyTakeIndexed() (or their
2107 * un-indexed equivalents). If the task was already in the Blocked state to
2108 * wait for a notification when the notification arrives then the task will
2109 * automatically be removed from the Blocked state (unblocked) and the
2110 * notification cleared.
2112 * **NOTE** Each notification within the array operates independently - a task
2113 * can only block on one notification within the array at a time and will not be
2114 * unblocked by a notification sent to any other array index.
2116 * Backward compatibility information:
2117 * Prior to FreeRTOS V10.4.0 each task had a single "notification value", and
2118 * all task notification API functions operated on that value. Replacing the
2119 * single notification value with an array of notification values necessitated a
2120 * new set of API functions that could address specific notifications within the
2121 * array. xTaskNotifyFromISR() is the original API function, and remains
2122 * backward compatible by always operating on the notification value at index 0
2123 * within the array. Calling xTaskNotifyFromISR() is equivalent to calling
2124 * xTaskNotifyIndexedFromISR() with the uxIndexToNotify parameter set to 0.
2126 * @param uxIndexToNotify The index within the target task's array of
2127 * notification values to which the notification is to be sent. uxIndexToNotify
2128 * must be less than configTASK_NOTIFICATION_ARRAY_ENTRIES. xTaskNotifyFromISR()
2129 * does not have this parameter and always sends notifications to index 0.
2131 * @param xTaskToNotify The handle of the task being notified. The handle to a
2132 * task can be returned from the xTaskCreate() API function used to create the
2133 * task, and the handle of the currently running task can be obtained by calling
2134 * xTaskGetCurrentTaskHandle().
2136 * @param ulValue Data that can be sent with the notification. How the data is
2137 * used depends on the value of the eAction parameter.
2139 * @param eAction Specifies how the notification updates the task's notification
2140 * value, if at all. Valid values for eAction are as follows:
2143 * The task's notification value is bitwise ORed with ulValue. xTaskNotify()
2144 * always returns pdPASS in this case.
2147 * The task's notification value is incremented. ulValue is not used and
2148 * xTaskNotify() always returns pdPASS in this case.
2150 * eSetValueWithOverwrite -
2151 * The task's notification value is set to the value of ulValue, even if the
2152 * task being notified had not yet processed the previous notification (the
2153 * task already had a notification pending). xTaskNotify() always returns
2154 * pdPASS in this case.
2156 * eSetValueWithoutOverwrite -
2157 * If the task being notified did not already have a notification pending then
2158 * the task's notification value is set to ulValue and xTaskNotify() will
2159 * return pdPASS. If the task being notified already had a notification
2160 * pending then no action is performed and pdFAIL is returned.
2163 * The task receives a notification without its notification value being
2164 * updated. ulValue is not used and xTaskNotify() always returns pdPASS in
2167 * @param pxHigherPriorityTaskWoken xTaskNotifyFromISR() will set
2168 * *pxHigherPriorityTaskWoken to pdTRUE if sending the notification caused the
2169 * task to which the notification was sent to leave the Blocked state, and the
2170 * unblocked task has a priority higher than the currently running task. If
2171 * xTaskNotifyFromISR() sets this value to pdTRUE then a context switch should
2172 * be requested before the interrupt is exited. How a context switch is
2173 * requested from an ISR is dependent on the port - see the documentation page
2174 * for the port in use.
2176 * @return Dependent on the value of eAction. See the description of the
2177 * eAction parameter.
2179 * \defgroup xTaskNotifyIndexedFromISR xTaskNotifyIndexedFromISR
2180 * \ingroup TaskNotifications
2182 BaseType_t xTaskGenericNotifyFromISR( TaskHandle_t xTaskToNotify,
2183 UBaseType_t uxIndexToNotify,
2185 eNotifyAction eAction,
2186 uint32_t * pulPreviousNotificationValue,
2187 BaseType_t * pxHigherPriorityTaskWoken ) PRIVILEGED_FUNCTION;
2188 #define xTaskNotifyFromISR( xTaskToNotify, ulValue, eAction, pxHigherPriorityTaskWoken ) \
2189 xTaskGenericNotifyFromISR( ( xTaskToNotify ), ( tskDEFAULT_INDEX_TO_NOTIFY ), ( ulValue ), ( eAction ), NULL, ( pxHigherPriorityTaskWoken ) )
2190 #define xTaskNotifyIndexedFromISR( xTaskToNotify, uxIndexToNotify, ulValue, eAction, pxHigherPriorityTaskWoken ) \
2191 xTaskGenericNotifyFromISR( ( xTaskToNotify ), ( uxIndexToNotify ), ( ulValue ), ( eAction ), NULL, ( pxHigherPriorityTaskWoken ) )
2195 * <PRE>BaseType_t xTaskNotifyAndQueryIndexedFromISR( TaskHandle_t xTaskToNotify, UBaseType_t uxIndexToNotify, uint32_t ulValue, eNotifyAction eAction, uint32_t *pulPreviousNotificationValue, BaseType_t *pxHigherPriorityTaskWoken );</PRE>
2196 * <PRE>BaseType_t xTaskNotifyAndQueryFromISR( TaskHandle_t xTaskToNotify, uint32_t ulValue, eNotifyAction eAction, uint32_t *pulPreviousNotificationValue, BaseType_t *pxHigherPriorityTaskWoken );</PRE>
2198 * See https://www.FreeRTOS.org/RTOS-task-notifications.html for details.
2200 * xTaskNotifyAndQueryIndexedFromISR() performs the same operation as
2201 * xTaskNotifyIndexedFromISR() with the addition that it also returns the
2202 * subject task's prior notification value (the notification value at the time
2203 * the function is called rather than at the time the function returns) in the
2204 * additional pulPreviousNotifyValue parameter.
2206 * xTaskNotifyAndQueryFromISR() performs the same operation as
2207 * xTaskNotifyFromISR() with the addition that it also returns the subject
2208 * task's prior notification value (the notification value at the time the
2209 * function is called rather than at the time the function returns) in the
2210 * additional pulPreviousNotifyValue parameter.
2212 * \defgroup xTaskNotifyAndQueryIndexedFromISR xTaskNotifyAndQueryIndexedFromISR
2213 * \ingroup TaskNotifications
2215 #define xTaskNotifyAndQueryIndexedFromISR( xTaskToNotify, uxIndexToNotify, ulValue, eAction, pulPreviousNotificationValue, pxHigherPriorityTaskWoken ) \
2216 xTaskGenericNotifyFromISR( ( xTaskToNotify ), ( uxIndexToNotify ), ( ulValue ), ( eAction ), ( pulPreviousNotificationValue ), ( pxHigherPriorityTaskWoken ) )
2217 #define xTaskNotifyAndQueryFromISR( xTaskToNotify, ulValue, eAction, pulPreviousNotificationValue, pxHigherPriorityTaskWoken ) \
2218 xTaskGenericNotifyFromISR( ( xTaskToNotify ), ( tskDEFAULT_INDEX_TO_NOTIFY ), ( ulValue ), ( eAction ), ( pulPreviousNotificationValue ), ( pxHigherPriorityTaskWoken ) )
2223 * BaseType_t xTaskNotifyWaitIndexed( UBaseType_t uxIndexToWaitOn, uint32_t ulBitsToClearOnEntry, uint32_t ulBitsToClearOnExit, uint32_t *pulNotificationValue, TickType_t xTicksToWait );
2225 * BaseType_t xTaskNotifyWait( uint32_t ulBitsToClearOnEntry, uint32_t ulBitsToClearOnExit, uint32_t *pulNotificationValue, TickType_t xTicksToWait );
2228 * Waits for a direct to task notification to be pending at a given index within
2229 * an array of direct to task notifications.
2231 * See https://www.FreeRTOS.org/RTOS-task-notifications.html for details.
2233 * configUSE_TASK_NOTIFICATIONS must be undefined or defined as 1 for this
2234 * function to be available.
2236 * Each task has a private array of "notification values" (or 'notifications'),
2237 * each of which is a 32-bit unsigned integer (uint32_t). The constant
2238 * configTASK_NOTIFICATION_ARRAY_ENTRIES sets the number of indexes in the
2239 * array, and (for backward compatibility) defaults to 1 if left undefined.
2240 * Prior to FreeRTOS V10.4.0 there was only one notification value per task.
2242 * Events can be sent to a task using an intermediary object. Examples of such
2243 * objects are queues, semaphores, mutexes and event groups. Task notifications
2244 * are a method of sending an event directly to a task without the need for such
2245 * an intermediary object.
2247 * A notification sent to a task can optionally perform an action, such as
2248 * update, overwrite or increment one of the task's notification values. In
2249 * that way task notifications can be used to send data to a task, or be used as
2250 * light weight and fast binary or counting semaphores.
2252 * A notification sent to a task will remain pending until it is cleared by the
2253 * task calling xTaskNotifyWaitIndexed() or ulTaskNotifyTakeIndexed() (or their
2254 * un-indexed equivalents). If the task was already in the Blocked state to
2255 * wait for a notification when the notification arrives then the task will
2256 * automatically be removed from the Blocked state (unblocked) and the
2257 * notification cleared.
2259 * A task can use xTaskNotifyWaitIndexed() to [optionally] block to wait for a
2260 * notification to be pending, or ulTaskNotifyTakeIndexed() to [optionally] block
2261 * to wait for a notification value to have a non-zero value. The task does
2262 * not consume any CPU time while it is in the Blocked state.
2264 * **NOTE** Each notification within the array operates independently - a task
2265 * can only block on one notification within the array at a time and will not be
2266 * unblocked by a notification sent to any other array index.
2268 * Backward compatibility information:
2269 * Prior to FreeRTOS V10.4.0 each task had a single "notification value", and
2270 * all task notification API functions operated on that value. Replacing the
2271 * single notification value with an array of notification values necessitated a
2272 * new set of API functions that could address specific notifications within the
2273 * array. xTaskNotifyWait() is the original API function, and remains backward
2274 * compatible by always operating on the notification value at index 0 in the
2275 * array. Calling xTaskNotifyWait() is equivalent to calling
2276 * xTaskNotifyWaitIndexed() with the uxIndexToWaitOn parameter set to 0.
2278 * @param uxIndexToWaitOn The index within the calling task's array of
2279 * notification values on which the calling task will wait for a notification to
2280 * be received. uxIndexToWaitOn must be less than
2281 * configTASK_NOTIFICATION_ARRAY_ENTRIES. xTaskNotifyWait() does
2282 * not have this parameter and always waits for notifications on index 0.
2284 * @param ulBitsToClearOnEntry Bits that are set in ulBitsToClearOnEntry value
2285 * will be cleared in the calling task's notification value before the task
2286 * checks to see if any notifications are pending, and optionally blocks if no
2287 * notifications are pending. Setting ulBitsToClearOnEntry to ULONG_MAX (if
2288 * limits.h is included) or 0xffffffffUL (if limits.h is not included) will have
2289 * the effect of resetting the task's notification value to 0. Setting
2290 * ulBitsToClearOnEntry to 0 will leave the task's notification value unchanged.
2292 * @param ulBitsToClearOnExit If a notification is pending or received before
2293 * the calling task exits the xTaskNotifyWait() function then the task's
2294 * notification value (see the xTaskNotify() API function) is passed out using
2295 * the pulNotificationValue parameter. Then any bits that are set in
2296 * ulBitsToClearOnExit will be cleared in the task's notification value (note
2297 * *pulNotificationValue is set before any bits are cleared). Setting
2298 * ulBitsToClearOnExit to ULONG_MAX (if limits.h is included) or 0xffffffffUL
2299 * (if limits.h is not included) will have the effect of resetting the task's
2300 * notification value to 0 before the function exits. Setting
2301 * ulBitsToClearOnExit to 0 will leave the task's notification value unchanged
2302 * when the function exits (in which case the value passed out in
2303 * pulNotificationValue will match the task's notification value).
2305 * @param pulNotificationValue Used to pass the task's notification value out
2306 * of the function. Note the value passed out will not be effected by the
2307 * clearing of any bits caused by ulBitsToClearOnExit being non-zero.
2309 * @param xTicksToWait The maximum amount of time that the task should wait in
2310 * the Blocked state for a notification to be received, should a notification
2311 * not already be pending when xTaskNotifyWait() was called. The task
2312 * will not consume any processing time while it is in the Blocked state. This
2313 * is specified in kernel ticks, the macro pdMS_TO_TICKS( value_in_ms ) can be
2314 * used to convert a time specified in milliseconds to a time specified in
2317 * @return If a notification was received (including notifications that were
2318 * already pending when xTaskNotifyWait was called) then pdPASS is
2319 * returned. Otherwise pdFAIL is returned.
2321 * \defgroup xTaskNotifyWaitIndexed xTaskNotifyWaitIndexed
2322 * \ingroup TaskNotifications
2324 BaseType_t xTaskGenericNotifyWait( UBaseType_t uxIndexToWaitOn,
2325 uint32_t ulBitsToClearOnEntry,
2326 uint32_t ulBitsToClearOnExit,
2327 uint32_t * pulNotificationValue,
2328 TickType_t xTicksToWait ) PRIVILEGED_FUNCTION;
2329 #define xTaskNotifyWait( ulBitsToClearOnEntry, ulBitsToClearOnExit, pulNotificationValue, xTicksToWait ) \
2330 xTaskGenericNotifyWait( tskDEFAULT_INDEX_TO_NOTIFY, ( ulBitsToClearOnEntry ), ( ulBitsToClearOnExit ), ( pulNotificationValue ), ( xTicksToWait ) )
2331 #define xTaskNotifyWaitIndexed( uxIndexToWaitOn, ulBitsToClearOnEntry, ulBitsToClearOnExit, pulNotificationValue, xTicksToWait ) \
2332 xTaskGenericNotifyWait( ( uxIndexToWaitOn ), ( ulBitsToClearOnEntry ), ( ulBitsToClearOnExit ), ( pulNotificationValue ), ( xTicksToWait ) )
2336 * <PRE>BaseType_t xTaskNotifyGiveIndexed( TaskHandle_t xTaskToNotify, UBaseType_t uxIndexToNotify );</PRE>
2337 * <PRE>BaseType_t xTaskNotifyGive( TaskHandle_t xTaskToNotify );</PRE>
2339 * Sends a direct to task notification to a particular index in the target
2340 * task's notification array in a manner similar to giving a counting semaphore.
2342 * See https://www.FreeRTOS.org/RTOS-task-notifications.html for more details.
2344 * configUSE_TASK_NOTIFICATIONS must be undefined or defined as 1 for these
2345 * macros to be available.
2347 * Each task has a private array of "notification values" (or 'notifications'),
2348 * each of which is a 32-bit unsigned integer (uint32_t). The constant
2349 * configTASK_NOTIFICATION_ARRAY_ENTRIES sets the number of indexes in the
2350 * array, and (for backward compatibility) defaults to 1 if left undefined.
2351 * Prior to FreeRTOS V10.4.0 there was only one notification value per task.
2353 * Events can be sent to a task using an intermediary object. Examples of such
2354 * objects are queues, semaphores, mutexes and event groups. Task notifications
2355 * are a method of sending an event directly to a task without the need for such
2356 * an intermediary object.
2358 * A notification sent to a task can optionally perform an action, such as
2359 * update, overwrite or increment one of the task's notification values. In
2360 * that way task notifications can be used to send data to a task, or be used as
2361 * light weight and fast binary or counting semaphores.
2363 * xTaskNotifyGiveIndexed() is a helper macro intended for use when task
2364 * notifications are used as light weight and faster binary or counting
2365 * semaphore equivalents. Actual FreeRTOS semaphores are given using the
2366 * xSemaphoreGive() API function, the equivalent action that instead uses a task
2367 * notification is xTaskNotifyGiveIndexed().
2369 * When task notifications are being used as a binary or counting semaphore
2370 * equivalent then the task being notified should wait for the notification
2371 * using the ulTaskNotificationTakeIndexed() API function rather than the
2372 * xTaskNotifyWaitIndexed() API function.
2374 * **NOTE** Each notification within the array operates independently - a task
2375 * can only block on one notification within the array at a time and will not be
2376 * unblocked by a notification sent to any other array index.
2378 * Backward compatibility information:
2379 * Prior to FreeRTOS V10.4.0 each task had a single "notification value", and
2380 * all task notification API functions operated on that value. Replacing the
2381 * single notification value with an array of notification values necessitated a
2382 * new set of API functions that could address specific notifications within the
2383 * array. xTaskNotifyGive() is the original API function, and remains backward
2384 * compatible by always operating on the notification value at index 0 in the
2385 * array. Calling xTaskNotifyGive() is equivalent to calling
2386 * xTaskNotifyGiveIndexed() with the uxIndexToNotify parameter set to 0.
2388 * @param xTaskToNotify The handle of the task being notified. The handle to a
2389 * task can be returned from the xTaskCreate() API function used to create the
2390 * task, and the handle of the currently running task can be obtained by calling
2391 * xTaskGetCurrentTaskHandle().
2393 * @param uxIndexToNotify The index within the target task's array of
2394 * notification values to which the notification is to be sent. uxIndexToNotify
2395 * must be less than configTASK_NOTIFICATION_ARRAY_ENTRIES. xTaskNotifyGive()
2396 * does not have this parameter and always sends notifications to index 0.
2398 * @return xTaskNotifyGive() is a macro that calls xTaskNotify() with the
2399 * eAction parameter set to eIncrement - so pdPASS is always returned.
2401 * \defgroup xTaskNotifyGiveIndexed xTaskNotifyGiveIndexed
2402 * \ingroup TaskNotifications
2404 #define xTaskNotifyGive( xTaskToNotify ) \
2405 xTaskGenericNotify( ( xTaskToNotify ), ( tskDEFAULT_INDEX_TO_NOTIFY ), ( 0 ), eIncrement, NULL )
2406 #define xTaskNotifyGiveIndexed( xTaskToNotify, uxIndexToNotify ) \
2407 xTaskGenericNotify( ( xTaskToNotify ), ( uxIndexToNotify ), ( 0 ), eIncrement, NULL )
2411 * <PRE>void vTaskNotifyGiveIndexedFromISR( TaskHandle_t xTaskHandle, UBaseType_t uxIndexToNotify, BaseType_t *pxHigherPriorityTaskWoken );</PRE>
2412 * <PRE>void vTaskNotifyGiveFromISR( TaskHandle_t xTaskHandle, BaseType_t *pxHigherPriorityTaskWoken );</PRE>
2414 * A version of xTaskNotifyGiveIndexed() that can be called from an interrupt
2415 * service routine (ISR).
2417 * See https://www.FreeRTOS.org/RTOS-task-notifications.html for more details.
2419 * configUSE_TASK_NOTIFICATIONS must be undefined or defined as 1 for this macro
2422 * Each task has a private array of "notification values" (or 'notifications'),
2423 * each of which is a 32-bit unsigned integer (uint32_t). The constant
2424 * configTASK_NOTIFICATION_ARRAY_ENTRIES sets the number of indexes in the
2425 * array, and (for backward compatibility) defaults to 1 if left undefined.
2426 * Prior to FreeRTOS V10.4.0 there was only one notification value per task.
2428 * Events can be sent to a task using an intermediary object. Examples of such
2429 * objects are queues, semaphores, mutexes and event groups. Task notifications
2430 * are a method of sending an event directly to a task without the need for such
2431 * an intermediary object.
2433 * A notification sent to a task can optionally perform an action, such as
2434 * update, overwrite or increment one of the task's notification values. In
2435 * that way task notifications can be used to send data to a task, or be used as
2436 * light weight and fast binary or counting semaphores.
2438 * vTaskNotifyGiveIndexedFromISR() is intended for use when task notifications
2439 * are used as light weight and faster binary or counting semaphore equivalents.
2440 * Actual FreeRTOS semaphores are given from an ISR using the
2441 * xSemaphoreGiveFromISR() API function, the equivalent action that instead uses
2442 * a task notification is vTaskNotifyGiveIndexedFromISR().
2444 * When task notifications are being used as a binary or counting semaphore
2445 * equivalent then the task being notified should wait for the notification
2446 * using the ulTaskNotificationTakeIndexed() API function rather than the
2447 * xTaskNotifyWaitIndexed() API function.
2449 * **NOTE** Each notification within the array operates independently - a task
2450 * can only block on one notification within the array at a time and will not be
2451 * unblocked by a notification sent to any other array index.
2453 * Backward compatibility information:
2454 * Prior to FreeRTOS V10.4.0 each task had a single "notification value", and
2455 * all task notification API functions operated on that value. Replacing the
2456 * single notification value with an array of notification values necessitated a
2457 * new set of API functions that could address specific notifications within the
2458 * array. xTaskNotifyFromISR() is the original API function, and remains
2459 * backward compatible by always operating on the notification value at index 0
2460 * within the array. Calling xTaskNotifyGiveFromISR() is equivalent to calling
2461 * xTaskNotifyGiveIndexedFromISR() with the uxIndexToNotify parameter set to 0.
2463 * @param xTaskToNotify The handle of the task being notified. The handle to a
2464 * task can be returned from the xTaskCreate() API function used to create the
2465 * task, and the handle of the currently running task can be obtained by calling
2466 * xTaskGetCurrentTaskHandle().
2468 * @param uxIndexToNotify The index within the target task's array of
2469 * notification values to which the notification is to be sent. uxIndexToNotify
2470 * must be less than configTASK_NOTIFICATION_ARRAY_ENTRIES.
2471 * xTaskNotifyGiveFromISR() does not have this parameter and always sends
2472 * notifications to index 0.
2474 * @param pxHigherPriorityTaskWoken vTaskNotifyGiveFromISR() will set
2475 * *pxHigherPriorityTaskWoken to pdTRUE if sending the notification caused the
2476 * task to which the notification was sent to leave the Blocked state, and the
2477 * unblocked task has a priority higher than the currently running task. If
2478 * vTaskNotifyGiveFromISR() sets this value to pdTRUE then a context switch
2479 * should be requested before the interrupt is exited. How a context switch is
2480 * requested from an ISR is dependent on the port - see the documentation page
2481 * for the port in use.
2483 * \defgroup vTaskNotifyGiveIndexedFromISR vTaskNotifyGiveIndexedFromISR
2484 * \ingroup TaskNotifications
2486 void vTaskGenericNotifyGiveFromISR( TaskHandle_t xTaskToNotify,
2487 UBaseType_t uxIndexToNotify,
2488 BaseType_t * pxHigherPriorityTaskWoken ) PRIVILEGED_FUNCTION;
2489 #define vTaskNotifyGiveFromISR( xTaskToNotify, pxHigherPriorityTaskWoken ) \
2490 vTaskGenericNotifyGiveFromISR( ( xTaskToNotify ), ( tskDEFAULT_INDEX_TO_NOTIFY ), ( pxHigherPriorityTaskWoken ) );
2491 #define vTaskNotifyGiveIndexedFromISR( xTaskToNotify, uxIndexToNotify, pxHigherPriorityTaskWoken ) \
2492 vTaskGenericNotifyGiveFromISR( ( xTaskToNotify ), ( uxIndexToNotify ), ( pxHigherPriorityTaskWoken ) );
2497 * uint32_t ulTaskNotifyTakeIndexed( UBaseType_t uxIndexToWaitOn, BaseType_t xClearCountOnExit, TickType_t xTicksToWait );
2499 * uint32_t ulTaskNotifyTake( BaseType_t xClearCountOnExit, TickType_t xTicksToWait );
2502 * Waits for a direct to task notification on a particular index in the calling
2503 * task's notification array in a manner similar to taking a counting semaphore.
2505 * See https://www.FreeRTOS.org/RTOS-task-notifications.html for details.
2507 * configUSE_TASK_NOTIFICATIONS must be undefined or defined as 1 for this
2508 * function to be available.
2510 * Each task has a private array of "notification values" (or 'notifications'),
2511 * each of which is a 32-bit unsigned integer (uint32_t). The constant
2512 * configTASK_NOTIFICATION_ARRAY_ENTRIES sets the number of indexes in the
2513 * array, and (for backward compatibility) defaults to 1 if left undefined.
2514 * Prior to FreeRTOS V10.4.0 there was only one notification value per task.
2516 * Events can be sent to a task using an intermediary object. Examples of such
2517 * objects are queues, semaphores, mutexes and event groups. Task notifications
2518 * are a method of sending an event directly to a task without the need for such
2519 * an intermediary object.
2521 * A notification sent to a task can optionally perform an action, such as
2522 * update, overwrite or increment one of the task's notification values. In
2523 * that way task notifications can be used to send data to a task, or be used as
2524 * light weight and fast binary or counting semaphores.
2526 * ulTaskNotifyTakeIndexed() is intended for use when a task notification is
2527 * used as a faster and lighter weight binary or counting semaphore alternative.
2528 * Actual FreeRTOS semaphores are taken using the xSemaphoreTake() API function,
2529 * the equivalent action that instead uses a task notification is
2530 * ulTaskNotifyTakeIndexed().
2532 * When a task is using its notification value as a binary or counting semaphore
2533 * other tasks should send notifications to it using the xTaskNotifyGiveIndexed()
2534 * macro, or xTaskNotifyIndex() function with the eAction parameter set to
2537 * ulTaskNotifyTakeIndexed() can either clear the task's notification value at
2538 * the array index specified by the uxIndexToWaitOn parameter to zero on exit,
2539 * in which case the notification value acts like a binary semaphore, or
2540 * decrement the notification value on exit, in which case the notification
2541 * value acts like a counting semaphore.
2543 * A task can use ulTaskNotifyTakeIndexed() to [optionally] block to wait for
2544 * a notification. The task does not consume any CPU time while it is in the
2547 * Where as xTaskNotifyWaitIndexed() will return when a notification is pending,
2548 * ulTaskNotifyTakeIndexed() will return when the task's notification value is
2551 * **NOTE** Each notification within the array operates independently - a task
2552 * can only block on one notification within the array at a time and will not be
2553 * unblocked by a notification sent to any other array index.
2555 * Backward compatibility information:
2556 * Prior to FreeRTOS V10.4.0 each task had a single "notification value", and
2557 * all task notification API functions operated on that value. Replacing the
2558 * single notification value with an array of notification values necessitated a
2559 * new set of API functions that could address specific notifications within the
2560 * array. ulTaskNotifyTake() is the original API function, and remains backward
2561 * compatible by always operating on the notification value at index 0 in the
2562 * array. Calling ulTaskNotifyTake() is equivalent to calling
2563 * ulTaskNotifyTakeIndexed() with the uxIndexToWaitOn parameter set to 0.
2565 * @param uxIndexToWaitOn The index within the calling task's array of
2566 * notification values on which the calling task will wait for a notification to
2567 * be non-zero. uxIndexToWaitOn must be less than
2568 * configTASK_NOTIFICATION_ARRAY_ENTRIES. xTaskNotifyTake() does
2569 * not have this parameter and always waits for notifications on index 0.
2571 * @param xClearCountOnExit if xClearCountOnExit is pdFALSE then the task's
2572 * notification value is decremented when the function exits. In this way the
2573 * notification value acts like a counting semaphore. If xClearCountOnExit is
2574 * not pdFALSE then the task's notification value is cleared to zero when the
2575 * function exits. In this way the notification value acts like a binary
2578 * @param xTicksToWait The maximum amount of time that the task should wait in
2579 * the Blocked state for the task's notification value to be greater than zero,
2580 * should the count not already be greater than zero when
2581 * ulTaskNotifyTake() was called. The task will not consume any processing
2582 * time while it is in the Blocked state. This is specified in kernel ticks,
2583 * the macro pdMS_TO_TICKS( value_in_ms ) can be used to convert a time
2584 * specified in milliseconds to a time specified in ticks.
2586 * @return The task's notification count before it is either cleared to zero or
2587 * decremented (see the xClearCountOnExit parameter).
2589 * \defgroup ulTaskNotifyTakeIndexed ulTaskNotifyTakeIndexed
2590 * \ingroup TaskNotifications
2592 uint32_t ulTaskGenericNotifyTake( UBaseType_t uxIndexToWaitOn,
2593 BaseType_t xClearCountOnExit,
2594 TickType_t xTicksToWait ) PRIVILEGED_FUNCTION;
2595 #define ulTaskNotifyTake( xClearCountOnExit, xTicksToWait ) \
2596 ulTaskGenericNotifyTake( ( tskDEFAULT_INDEX_TO_NOTIFY ), ( xClearCountOnExit ), ( xTicksToWait ) )
2597 #define ulTaskNotifyTakeIndexed( uxIndexToWaitOn, xClearCountOnExit, xTicksToWait ) \
2598 ulTaskGenericNotifyTake( ( uxIndexToWaitOn ), ( xClearCountOnExit ), ( xTicksToWait ) )
2603 * BaseType_t xTaskNotifyStateClearIndexed( TaskHandle_t xTask, UBaseType_t uxIndexToCLear );
2605 * BaseType_t xTaskNotifyStateClear( TaskHandle_t xTask );
2608 * See https://www.FreeRTOS.org/RTOS-task-notifications.html for details.
2610 * configUSE_TASK_NOTIFICATIONS must be undefined or defined as 1 for these
2611 * functions to be available.
2613 * Each task has a private array of "notification values" (or 'notifications'),
2614 * each of which is a 32-bit unsigned integer (uint32_t). The constant
2615 * configTASK_NOTIFICATION_ARRAY_ENTRIES sets the number of indexes in the
2616 * array, and (for backward compatibility) defaults to 1 if left undefined.
2617 * Prior to FreeRTOS V10.4.0 there was only one notification value per task.
2619 * If a notification is sent to an index within the array of notifications then
2620 * the notification at that index is said to be 'pending' until it is read or
2621 * explicitly cleared by the receiving task. xTaskNotifyStateClearIndexed()
2622 * is the function that clears a pending notification without reading the
2623 * notification value. The notification value at the same array index is not
2624 * altered. Set xTask to NULL to clear the notification state of the calling
2627 * Backward compatibility information:
2628 * Prior to FreeRTOS V10.4.0 each task had a single "notification value", and
2629 * all task notification API functions operated on that value. Replacing the
2630 * single notification value with an array of notification values necessitated a
2631 * new set of API functions that could address specific notifications within the
2632 * array. xTaskNotifyStateClear() is the original API function, and remains
2633 * backward compatible by always operating on the notification value at index 0
2634 * within the array. Calling xTaskNotifyStateClear() is equivalent to calling
2635 * xTaskNotifyStateClearIndexed() with the uxIndexToNotify parameter set to 0.
2637 * @param xTask The handle of the RTOS task that will have a notification state
2638 * cleared. Set xTask to NULL to clear a notification state in the calling
2639 * task. To obtain a task's handle create the task using xTaskCreate() and
2640 * make use of the pxCreatedTask parameter, or create the task using
2641 * xTaskCreateStatic() and store the returned value, or use the task's name in
2642 * a call to xTaskGetHandle().
2644 * @param uxIndexToClear The index within the target task's array of
2645 * notification values to act upon. For example, setting uxIndexToClear to 1
2646 * will clear the state of the notification at index 1 within the array.
2647 * uxIndexToClear must be less than configTASK_NOTIFICATION_ARRAY_ENTRIES.
2648 * ulTaskNotifyStateClear() does not have this parameter and always acts on the
2649 * notification at index 0.
2651 * @return pdTRUE if the task's notification state was set to
2652 * eNotWaitingNotification, otherwise pdFALSE.
2654 * \defgroup xTaskNotifyStateClearIndexed xTaskNotifyStateClearIndexed
2655 * \ingroup TaskNotifications
2657 BaseType_t xTaskGenericNotifyStateClear( TaskHandle_t xTask,
2658 UBaseType_t uxIndexToClear ) PRIVILEGED_FUNCTION;
2659 #define xTaskNotifyStateClear( xTask ) \
2660 xTaskGenericNotifyStateClear( ( xTask ), ( tskDEFAULT_INDEX_TO_NOTIFY ) )
2661 #define xTaskNotifyStateClearIndexed( xTask, uxIndexToClear ) \
2662 xTaskGenericNotifyStateClear( ( xTask ), ( uxIndexToClear ) )
2667 * uint32_t ulTaskNotifyValueClearIndexed( TaskHandle_t xTask, UBaseType_t uxIndexToClear, uint32_t ulBitsToClear );
2669 * uint32_t ulTaskNotifyValueClear( TaskHandle_t xTask, uint32_t ulBitsToClear );
2672 * See https://www.FreeRTOS.org/RTOS-task-notifications.html for details.
2674 * configUSE_TASK_NOTIFICATIONS must be undefined or defined as 1 for these
2675 * functions to be available.
2677 * Each task has a private array of "notification values" (or 'notifications'),
2678 * each of which is a 32-bit unsigned integer (uint32_t). The constant
2679 * configTASK_NOTIFICATION_ARRAY_ENTRIES sets the number of indexes in the
2680 * array, and (for backward compatibility) defaults to 1 if left undefined.
2681 * Prior to FreeRTOS V10.4.0 there was only one notification value per task.
2683 * ulTaskNotifyValueClearIndexed() clears the bits specified by the
2684 * ulBitsToClear bit mask in the notification value at array index uxIndexToClear
2685 * of the task referenced by xTask.
2687 * Backward compatibility information:
2688 * Prior to FreeRTOS V10.4.0 each task had a single "notification value", and
2689 * all task notification API functions operated on that value. Replacing the
2690 * single notification value with an array of notification values necessitated a
2691 * new set of API functions that could address specific notifications within the
2692 * array. ulTaskNotifyValueClear() is the original API function, and remains
2693 * backward compatible by always operating on the notification value at index 0
2694 * within the array. Calling ulTaskNotifyValueClear() is equivalent to calling
2695 * ulTaskNotifyValueClearIndexed() with the uxIndexToClear parameter set to 0.
2697 * @param xTask The handle of the RTOS task that will have bits in one of its
2698 * notification values cleared. Set xTask to NULL to clear bits in a
2699 * notification value of the calling task. To obtain a task's handle create the
2700 * task using xTaskCreate() and make use of the pxCreatedTask parameter, or
2701 * create the task using xTaskCreateStatic() and store the returned value, or
2702 * use the task's name in a call to xTaskGetHandle().
2704 * @param uxIndexToClear The index within the target task's array of
2705 * notification values in which to clear the bits. uxIndexToClear
2706 * must be less than configTASK_NOTIFICATION_ARRAY_ENTRIES.
2707 * ulTaskNotifyValueClear() does not have this parameter and always clears bits
2708 * in the notification value at index 0.
2710 * @param ulBitsToClear Bit mask of the bits to clear in the notification value of
2711 * xTask. Set a bit to 1 to clear the corresponding bits in the task's notification
2712 * value. Set ulBitsToClear to 0xffffffff (UINT_MAX on 32-bit architectures) to clear
2713 * the notification value to 0. Set ulBitsToClear to 0 to query the task's
2714 * notification value without clearing any bits.
2717 * @return The value of the target task's notification value before the bits
2718 * specified by ulBitsToClear were cleared.
2719 * \defgroup ulTaskNotifyValueClear ulTaskNotifyValueClear
2720 * \ingroup TaskNotifications
2722 uint32_t ulTaskGenericNotifyValueClear( TaskHandle_t xTask,
2723 UBaseType_t uxIndexToClear,
2724 uint32_t ulBitsToClear ) PRIVILEGED_FUNCTION;
2725 #define ulTaskNotifyValueClear( xTask, ulBitsToClear ) \
2726 ulTaskGenericNotifyValueClear( ( xTask ), ( tskDEFAULT_INDEX_TO_NOTIFY ), ( ulBitsToClear ) )
2727 #define ulTaskNotifyValueClearIndexed( xTask, uxIndexToClear, ulBitsToClear ) \
2728 ulTaskGenericNotifyValueClear( ( xTask ), ( uxIndexToClear ), ( ulBitsToClear ) )
2733 * void vTaskSetTimeOutState( TimeOut_t * const pxTimeOut );
2736 * Capture the current time for future use with xTaskCheckForTimeOut().
2738 * @param pxTimeOut Pointer to a timeout object into which the current time
2739 * is to be captured. The captured time includes the tick count and the number
2740 * of times the tick count has overflowed since the system first booted.
2741 * \defgroup vTaskSetTimeOutState vTaskSetTimeOutState
2744 void vTaskSetTimeOutState( TimeOut_t * const pxTimeOut ) PRIVILEGED_FUNCTION;
2749 * BaseType_t xTaskCheckForTimeOut( TimeOut_t * const pxTimeOut, TickType_t * const pxTicksToWait );
2752 * Determines if pxTicksToWait ticks has passed since a time was captured
2753 * using a call to vTaskSetTimeOutState(). The captured time includes the tick
2754 * count and the number of times the tick count has overflowed.
2756 * @param pxTimeOut The time status as captured previously using
2757 * vTaskSetTimeOutState. If the timeout has not yet occurred, it is updated
2758 * to reflect the current time status.
2759 * @param pxTicksToWait The number of ticks to check for timeout i.e. if
2760 * pxTicksToWait ticks have passed since pxTimeOut was last updated (either by
2761 * vTaskSetTimeOutState() or xTaskCheckForTimeOut()), the timeout has occurred.
2762 * If the timeout has not occurred, pxTicksToWait is updated to reflect the
2763 * number of remaining ticks.
2765 * @return If timeout has occurred, pdTRUE is returned. Otherwise pdFALSE is
2766 * returned and pxTicksToWait is updated to reflect the number of remaining
2769 * @see https://www.FreeRTOS.org/xTaskCheckForTimeOut.html
2773 * // Driver library function used to receive uxWantedBytes from an Rx buffer
2774 * // that is filled by a UART interrupt. If there are not enough bytes in the
2775 * // Rx buffer then the task enters the Blocked state until it is notified that
2776 * // more data has been placed into the buffer. If there is still not enough
2777 * // data then the task re-enters the Blocked state, and xTaskCheckForTimeOut()
2778 * // is used to re-calculate the Block time to ensure the total amount of time
2779 * // spent in the Blocked state does not exceed MAX_TIME_TO_WAIT. This
2780 * // continues until either the buffer contains at least uxWantedBytes bytes,
2781 * // or the total amount of time spent in the Blocked state reaches
2782 * // MAX_TIME_TO_WAIT - at which point the task reads however many bytes are
2783 * // available up to a maximum of uxWantedBytes.
2785 * size_t xUART_Receive( uint8_t *pucBuffer, size_t uxWantedBytes )
2787 * size_t uxReceived = 0;
2788 * TickType_t xTicksToWait = MAX_TIME_TO_WAIT;
2789 * TimeOut_t xTimeOut;
2791 * // Initialize xTimeOut. This records the time at which this function
2793 * vTaskSetTimeOutState( &xTimeOut );
2795 * // Loop until the buffer contains the wanted number of bytes, or a
2796 * // timeout occurs.
2797 * while( UART_bytes_in_rx_buffer( pxUARTInstance ) < uxWantedBytes )
2799 * // The buffer didn't contain enough data so this task is going to
2800 * // enter the Blocked state. Adjusting xTicksToWait to account for
2801 * // any time that has been spent in the Blocked state within this
2802 * // function so far to ensure the total amount of time spent in the
2803 * // Blocked state does not exceed MAX_TIME_TO_WAIT.
2804 * if( xTaskCheckForTimeOut( &xTimeOut, &xTicksToWait ) != pdFALSE )
2806 * //Timed out before the wanted number of bytes were available,
2811 * // Wait for a maximum of xTicksToWait ticks to be notified that the
2812 * // receive interrupt has placed more data into the buffer.
2813 * ulTaskNotifyTake( pdTRUE, xTicksToWait );
2816 * // Attempt to read uxWantedBytes from the receive buffer into pucBuffer.
2817 * // The actual number of bytes read (which might be less than
2818 * // uxWantedBytes) is returned.
2819 * uxReceived = UART_read_from_receive_buffer( pxUARTInstance,
2823 * return uxReceived;
2826 * \defgroup xTaskCheckForTimeOut xTaskCheckForTimeOut
2829 BaseType_t xTaskCheckForTimeOut( TimeOut_t * const pxTimeOut,
2830 TickType_t * const pxTicksToWait ) PRIVILEGED_FUNCTION;
2835 * BaseType_t xTaskCatchUpTicks( TickType_t xTicksToCatchUp );
2838 * This function corrects the tick count value after the application code has held
2839 * interrupts disabled for an extended period resulting in tick interrupts having
2842 * This function is similar to vTaskStepTick(), however, unlike
2843 * vTaskStepTick(), xTaskCatchUpTicks() may move the tick count forward past a
2844 * time at which a task should be removed from the blocked state. That means
2845 * tasks may have to be removed from the blocked state as the tick count is
2848 * @param xTicksToCatchUp The number of tick interrupts that have been missed due to
2849 * interrupts being disabled. Its value is not computed automatically, so must be
2850 * computed by the application writer.
2852 * @return pdTRUE if moving the tick count forward resulted in a task leaving the
2853 * blocked state and a context switch being performed. Otherwise pdFALSE.
2855 * \defgroup xTaskCatchUpTicks xTaskCatchUpTicks
2858 BaseType_t xTaskCatchUpTicks( TickType_t xTicksToCatchUp ) PRIVILEGED_FUNCTION;
2861 /*-----------------------------------------------------------
2862 * SCHEDULER INTERNALS AVAILABLE FOR PORTING PURPOSES
2863 *----------------------------------------------------------*/
2866 * THIS FUNCTION MUST NOT BE USED FROM APPLICATION CODE. IT IS ONLY
2867 * INTENDED FOR USE WHEN IMPLEMENTING A PORT OF THE SCHEDULER AND IS
2868 * AN INTERFACE WHICH IS FOR THE EXCLUSIVE USE OF THE SCHEDULER.
2870 * Called from the real time kernel tick (either preemptive or cooperative),
2871 * this increments the tick count and checks if any tasks that are blocked
2872 * for a finite period required removing from a blocked list and placing on
2873 * a ready list. If a non-zero value is returned then a context switch is
2874 * required because either:
2875 * + A task was removed from a blocked list because its timeout had expired,
2877 * + Time slicing is in use and there is a task of equal priority to the
2878 * currently running task.
2880 BaseType_t xTaskIncrementTick( void ) PRIVILEGED_FUNCTION;
2883 * THIS FUNCTION MUST NOT BE USED FROM APPLICATION CODE. IT IS AN
2884 * INTERFACE WHICH IS FOR THE EXCLUSIVE USE OF THE SCHEDULER.
2886 * THIS FUNCTION MUST BE CALLED WITH INTERRUPTS DISABLED.
2888 * Removes the calling task from the ready list and places it both
2889 * on the list of tasks waiting for a particular event, and the
2890 * list of delayed tasks. The task will be removed from both lists
2891 * and replaced on the ready list should either the event occur (and
2892 * there be no higher priority tasks waiting on the same event) or
2893 * the delay period expires.
2895 * The 'unordered' version replaces the event list item value with the
2896 * xItemValue value, and inserts the list item at the end of the list.
2898 * The 'ordered' version uses the existing event list item value (which is the
2899 * owning task's priority) to insert the list item into the event list in task
2902 * @param pxEventList The list containing tasks that are blocked waiting
2903 * for the event to occur.
2905 * @param xItemValue The item value to use for the event list item when the
2906 * event list is not ordered by task priority.
2908 * @param xTicksToWait The maximum amount of time that the task should wait
2909 * for the event to occur. This is specified in kernel ticks, the constant
2910 * portTICK_PERIOD_MS can be used to convert kernel ticks into a real time
2913 void vTaskPlaceOnEventList( List_t * const pxEventList,
2914 const TickType_t xTicksToWait ) PRIVILEGED_FUNCTION;
2915 void vTaskPlaceOnUnorderedEventList( List_t * pxEventList,
2916 const TickType_t xItemValue,
2917 const TickType_t xTicksToWait ) PRIVILEGED_FUNCTION;
2920 * THIS FUNCTION MUST NOT BE USED FROM APPLICATION CODE. IT IS AN
2921 * INTERFACE WHICH IS FOR THE EXCLUSIVE USE OF THE SCHEDULER.
2923 * THIS FUNCTION MUST BE CALLED WITH INTERRUPTS DISABLED.
2925 * This function performs nearly the same function as vTaskPlaceOnEventList().
2926 * The difference being that this function does not permit tasks to block
2927 * indefinitely, whereas vTaskPlaceOnEventList() does.
2930 void vTaskPlaceOnEventListRestricted( List_t * const pxEventList,
2931 TickType_t xTicksToWait,
2932 const BaseType_t xWaitIndefinitely ) PRIVILEGED_FUNCTION;
2935 * THIS FUNCTION MUST NOT BE USED FROM APPLICATION CODE. IT IS AN
2936 * INTERFACE WHICH IS FOR THE EXCLUSIVE USE OF THE SCHEDULER.
2938 * THIS FUNCTION MUST BE CALLED WITH INTERRUPTS DISABLED.
2940 * Removes a task from both the specified event list and the list of blocked
2941 * tasks, and places it on a ready queue.
2943 * xTaskRemoveFromEventList()/vTaskRemoveFromUnorderedEventList() will be called
2944 * if either an event occurs to unblock a task, or the block timeout period
2947 * xTaskRemoveFromEventList() is used when the event list is in task priority
2948 * order. It removes the list item from the head of the event list as that will
2949 * have the highest priority owning task of all the tasks on the event list.
2950 * vTaskRemoveFromUnorderedEventList() is used when the event list is not
2951 * ordered and the event list items hold something other than the owning tasks
2952 * priority. In this case the event list item value is updated to the value
2953 * passed in the xItemValue parameter.
2955 * @return pdTRUE if the task being removed has a higher priority than the task
2956 * making the call, otherwise pdFALSE.
2958 BaseType_t xTaskRemoveFromEventList( const List_t * const pxEventList ) PRIVILEGED_FUNCTION;
2959 void vTaskRemoveFromUnorderedEventList( ListItem_t * pxEventListItem,
2960 const TickType_t xItemValue ) PRIVILEGED_FUNCTION;
2963 * THIS FUNCTION MUST NOT BE USED FROM APPLICATION CODE. IT IS ONLY
2964 * INTENDED FOR USE WHEN IMPLEMENTING A PORT OF THE SCHEDULER AND IS
2965 * AN INTERFACE WHICH IS FOR THE EXCLUSIVE USE OF THE SCHEDULER.
2967 * Sets the pointer to the current TCB to the TCB of the highest priority task
2968 * that is ready to run.
2970 portDONT_DISCARD void vTaskSwitchContext( void ) PRIVILEGED_FUNCTION;
2973 * THESE FUNCTIONS MUST NOT BE USED FROM APPLICATION CODE. THEY ARE USED BY
2974 * THE EVENT BITS MODULE.
2976 TickType_t uxTaskResetEventItemValue( void ) PRIVILEGED_FUNCTION;
2979 * Return the handle of the calling task.
2981 TaskHandle_t xTaskGetCurrentTaskHandle( void ) PRIVILEGED_FUNCTION;
2984 * Shortcut used by the queue implementation to prevent unnecessary call to
2987 void vTaskMissedYield( void ) PRIVILEGED_FUNCTION;
2990 * Returns the scheduler state as taskSCHEDULER_RUNNING,
2991 * taskSCHEDULER_NOT_STARTED or taskSCHEDULER_SUSPENDED.
2993 BaseType_t xTaskGetSchedulerState( void ) PRIVILEGED_FUNCTION;
2996 * Raises the priority of the mutex holder to that of the calling task should
2997 * the mutex holder have a priority less than the calling task.
2999 BaseType_t xTaskPriorityInherit( TaskHandle_t const pxMutexHolder ) PRIVILEGED_FUNCTION;
3002 * Set the priority of a task back to its proper priority in the case that it
3003 * inherited a higher priority while it was holding a semaphore.
3005 BaseType_t xTaskPriorityDisinherit( TaskHandle_t const pxMutexHolder ) PRIVILEGED_FUNCTION;
3008 * If a higher priority task attempting to obtain a mutex caused a lower
3009 * priority task to inherit the higher priority task's priority - but the higher
3010 * priority task then timed out without obtaining the mutex, then the lower
3011 * priority task will disinherit the priority again - but only down as far as
3012 * the highest priority task that is still waiting for the mutex (if there were
3013 * more than one task waiting for the mutex).
3015 void vTaskPriorityDisinheritAfterTimeout( TaskHandle_t const pxMutexHolder,
3016 UBaseType_t uxHighestPriorityWaitingTask ) PRIVILEGED_FUNCTION;
3019 * Get the uxTCBNumber assigned to the task referenced by the xTask parameter.
3021 UBaseType_t uxTaskGetTaskNumber( TaskHandle_t xTask ) PRIVILEGED_FUNCTION;
3024 * Set the uxTaskNumber of the task referenced by the xTask parameter to
3027 void vTaskSetTaskNumber( TaskHandle_t xTask,
3028 const UBaseType_t uxHandle ) PRIVILEGED_FUNCTION;
3031 * Only available when configUSE_TICKLESS_IDLE is set to 1.
3032 * If tickless mode is being used, or a low power mode is implemented, then
3033 * the tick interrupt will not execute during idle periods. When this is the
3034 * case, the tick count value maintained by the scheduler needs to be kept up
3035 * to date with the actual execution time by being skipped forward by a time
3036 * equal to the idle period.
3038 void vTaskStepTick( const TickType_t xTicksToJump ) PRIVILEGED_FUNCTION;
3041 * Only available when configUSE_TICKLESS_IDLE is set to 1.
3042 * Provided for use within portSUPPRESS_TICKS_AND_SLEEP() to allow the port
3043 * specific sleep function to determine if it is ok to proceed with the sleep,
3044 * and if it is ok to proceed, if it is ok to sleep indefinitely.
3046 * This function is necessary because portSUPPRESS_TICKS_AND_SLEEP() is only
3047 * called with the scheduler suspended, not from within a critical section. It
3048 * is therefore possible for an interrupt to request a context switch between
3049 * portSUPPRESS_TICKS_AND_SLEEP() and the low power mode actually being
3050 * entered. eTaskConfirmSleepModeStatus() should be called from a short
3051 * critical section between the timer being stopped and the sleep mode being
3052 * entered to ensure it is ok to proceed into the sleep mode.
3054 eSleepModeStatus eTaskConfirmSleepModeStatus( void ) PRIVILEGED_FUNCTION;
3057 * For internal use only. Increment the mutex held count when a mutex is
3058 * taken and return the handle of the task that has taken the mutex.
3060 TaskHandle_t pvTaskIncrementMutexHeldCount( void ) PRIVILEGED_FUNCTION;
3063 * For internal use only. Same as vTaskSetTimeOutState(), but without a critical
3066 void vTaskInternalSetTimeOutState( TimeOut_t * const pxTimeOut ) PRIVILEGED_FUNCTION;
3074 #endif /* INC_TASK_H */