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 #if ( ( portSTACK_GROWTH > 0 ) && ( configRECORD_STACK_HIGH_ADDRESS == 1 ) )
165 StackType_t * pxTopOfStack; /* Points to the top address of the task's stack area. */
166 StackType_t * pxEndOfStack; /* Points to the end address of the task's stack area. */
168 configSTACK_DEPTH_TYPE usStackHighWaterMark; /* The minimum amount of stack space that has remained for the task since the task was created. The closer this value is to zero the closer the task has come to overflowing its stack. */
171 /* Possible return values for eTaskConfirmSleepModeStatus(). */
174 eAbortSleep = 0, /* A task has been made ready or a context switch pended since portSUPPRESS_TICKS_AND_SLEEP() was called - abort entering a sleep mode. */
175 eStandardSleep, /* Enter a sleep mode that will not last any longer than the expected idle time. */
176 #if ( INCLUDE_vTaskSuspend == 1 )
177 eNoTasksWaitingTimeout /* No tasks are waiting for a timeout so it is safe to enter a sleep mode that can only be exited by an external interrupt. */
178 #endif /* INCLUDE_vTaskSuspend */
182 * Defines the priority used by the idle task. This must not be modified.
186 #define tskIDLE_PRIORITY ( ( UBaseType_t ) 0U )
191 * Macro for forcing a context switch.
193 * \defgroup taskYIELD taskYIELD
194 * \ingroup SchedulerControl
196 #define taskYIELD() portYIELD()
201 * Macro to mark the start of a critical code region. Preemptive context
202 * switches cannot occur when in a critical region.
204 * NOTE: This may alter the stack (depending on the portable implementation)
205 * so must be used with care!
207 * \defgroup taskENTER_CRITICAL taskENTER_CRITICAL
208 * \ingroup SchedulerControl
210 #define taskENTER_CRITICAL() portENTER_CRITICAL()
211 #define taskENTER_CRITICAL_FROM_ISR() portSET_INTERRUPT_MASK_FROM_ISR()
216 * Macro to mark the end of a critical code region. Preemptive context
217 * switches cannot occur when in a critical region.
219 * NOTE: This may alter the stack (depending on the portable implementation)
220 * so must be used with care!
222 * \defgroup taskEXIT_CRITICAL taskEXIT_CRITICAL
223 * \ingroup SchedulerControl
225 #define taskEXIT_CRITICAL() portEXIT_CRITICAL()
226 #define taskEXIT_CRITICAL_FROM_ISR( x ) portCLEAR_INTERRUPT_MASK_FROM_ISR( x )
231 * Macro to disable all maskable interrupts.
233 * \defgroup taskDISABLE_INTERRUPTS taskDISABLE_INTERRUPTS
234 * \ingroup SchedulerControl
236 #define taskDISABLE_INTERRUPTS() portDISABLE_INTERRUPTS()
241 * Macro to enable microcontroller interrupts.
243 * \defgroup taskENABLE_INTERRUPTS taskENABLE_INTERRUPTS
244 * \ingroup SchedulerControl
246 #define taskENABLE_INTERRUPTS() portENABLE_INTERRUPTS()
248 /* Definitions returned by xTaskGetSchedulerState(). taskSCHEDULER_SUSPENDED is
249 * 0 to generate more optimal code when configASSERT() is defined as the constant
250 * is used in assert() statements. */
251 #define taskSCHEDULER_SUSPENDED ( ( BaseType_t ) 0 )
252 #define taskSCHEDULER_NOT_STARTED ( ( BaseType_t ) 1 )
253 #define taskSCHEDULER_RUNNING ( ( BaseType_t ) 2 )
256 /*-----------------------------------------------------------
258 *----------------------------------------------------------*/
263 * BaseType_t xTaskCreate(
264 * TaskFunction_t pxTaskCode,
265 * const char *pcName,
266 * configSTACK_DEPTH_TYPE usStackDepth,
267 * void *pvParameters,
268 * UBaseType_t uxPriority,
269 * TaskHandle_t *pxCreatedTask
273 * Create a new task and add it to the list of tasks that are ready to run.
275 * Internally, within the FreeRTOS implementation, tasks use two blocks of
276 * memory. The first block is used to hold the task's data structures. The
277 * second block is used by the task as its stack. If a task is created using
278 * xTaskCreate() then both blocks of memory are automatically dynamically
279 * allocated inside the xTaskCreate() function. (see
280 * https://www.FreeRTOS.org/a00111.html). If a task is created using
281 * xTaskCreateStatic() then the application writer must provide the required
282 * memory. xTaskCreateStatic() therefore allows a task to be created without
283 * using any dynamic memory allocation.
285 * See xTaskCreateStatic() for a version that does not use any dynamic memory
288 * xTaskCreate() can only be used to create a task that has unrestricted
289 * access to the entire microcontroller memory map. Systems that include MPU
290 * support can alternatively create an MPU constrained task using
291 * xTaskCreateRestricted().
293 * @param pxTaskCode Pointer to the task entry function. Tasks
294 * must be implemented to never return (i.e. continuous loop).
296 * @param pcName A descriptive name for the task. This is mainly used to
297 * facilitate debugging. Max length defined by configMAX_TASK_NAME_LEN - default
300 * @param usStackDepth The size of the task stack specified as the number of
301 * variables the stack can hold - not the number of bytes. For example, if
302 * the stack is 16 bits wide and usStackDepth is defined as 100, 200 bytes
303 * will be allocated for stack storage.
305 * @param pvParameters Pointer that will be used as the parameter for the task
308 * @param uxPriority The priority at which the task should run. Systems that
309 * include MPU support can optionally create tasks in a privileged (system)
310 * mode by setting bit portPRIVILEGE_BIT of the priority parameter. For
311 * example, to create a privileged task at priority 2 the uxPriority parameter
312 * should be set to ( 2 | portPRIVILEGE_BIT ).
314 * @param pxCreatedTask Used to pass back a handle by which the created task
317 * @return pdPASS if the task was successfully created and added to a ready
318 * list, otherwise an error code defined in the file projdefs.h
322 * // Task to be created.
323 * void vTaskCode( void * pvParameters )
327 * // Task code goes here.
331 * // Function that creates a task.
332 * void vOtherFunction( void )
334 * static uint8_t ucParameterToPass;
335 * TaskHandle_t xHandle = NULL;
337 * // Create the task, storing the handle. Note that the passed parameter ucParameterToPass
338 * // must exist for the lifetime of the task, so in this case is declared static. If it was just an
339 * // an automatic stack variable it might no longer exist, or at least have been corrupted, by the time
340 * // the new task attempts to access it.
341 * xTaskCreate( vTaskCode, "NAME", STACK_SIZE, &ucParameterToPass, tskIDLE_PRIORITY, &xHandle );
342 * configASSERT( xHandle );
344 * // Use the handle to delete the task.
345 * if( xHandle != NULL )
347 * vTaskDelete( xHandle );
351 * \defgroup xTaskCreate xTaskCreate
354 #if ( configSUPPORT_DYNAMIC_ALLOCATION == 1 )
355 BaseType_t xTaskCreate( TaskFunction_t pxTaskCode,
356 const char * const pcName, /*lint !e971 Unqualified char types are allowed for strings and single characters only. */
357 const configSTACK_DEPTH_TYPE usStackDepth,
358 void * const pvParameters,
359 UBaseType_t uxPriority,
360 TaskHandle_t * const pxCreatedTask ) PRIVILEGED_FUNCTION;
366 * TaskHandle_t xTaskCreateStatic( TaskFunction_t pxTaskCode,
367 * const char *pcName,
368 * uint32_t ulStackDepth,
369 * void *pvParameters,
370 * UBaseType_t uxPriority,
371 * StackType_t *puxStackBuffer,
372 * StaticTask_t *pxTaskBuffer );
375 * Create a new task and add it to the list of tasks that are ready to run.
377 * Internally, within the FreeRTOS implementation, tasks use two blocks of
378 * memory. The first block is used to hold the task's data structures. The
379 * second block is used by the task as its stack. If a task is created using
380 * xTaskCreate() then both blocks of memory are automatically dynamically
381 * allocated inside the xTaskCreate() function. (see
382 * https://www.FreeRTOS.org/a00111.html). If a task is created using
383 * xTaskCreateStatic() then the application writer must provide the required
384 * memory. xTaskCreateStatic() therefore allows a task to be created without
385 * using any dynamic memory allocation.
387 * @param pxTaskCode Pointer to the task entry function. Tasks
388 * must be implemented to never return (i.e. continuous loop).
390 * @param pcName A descriptive name for the task. This is mainly used to
391 * facilitate debugging. The maximum length of the string is defined by
392 * configMAX_TASK_NAME_LEN in FreeRTOSConfig.h.
394 * @param ulStackDepth The size of the task stack specified as the number of
395 * variables the stack can hold - not the number of bytes. For example, if
396 * the stack is 32-bits wide and ulStackDepth is defined as 100 then 400 bytes
397 * will be allocated for stack storage.
399 * @param pvParameters Pointer that will be used as the parameter for the task
402 * @param uxPriority The priority at which the task will run.
404 * @param puxStackBuffer Must point to a StackType_t array that has at least
405 * ulStackDepth indexes - the array will then be used as the task's stack,
406 * removing the need for the stack to be allocated dynamically.
408 * @param pxTaskBuffer Must point to a variable of type StaticTask_t, which will
409 * then be used to hold the task's data structures, removing the need for the
410 * memory to be allocated dynamically.
412 * @return If neither puxStackBuffer nor pxTaskBuffer are NULL, then the task
413 * will be created and a handle to the created task is returned. If either
414 * puxStackBuffer or pxTaskBuffer are NULL then the task will not be created and
420 * // Dimensions of the buffer that the task being created will use as its stack.
421 * // NOTE: This is the number of words the stack will hold, not the number of
422 * // bytes. For example, if each stack item is 32-bits, and this is set to 100,
423 * // then 400 bytes (100 * 32-bits) will be allocated.
424 #define STACK_SIZE 200
426 * // Structure that will hold the TCB of the task being created.
427 * StaticTask_t xTaskBuffer;
429 * // Buffer that the task being created will use as its stack. Note this is
430 * // an array of StackType_t variables. The size of StackType_t is dependent on
432 * StackType_t xStack[ STACK_SIZE ];
434 * // Function that implements the task being created.
435 * void vTaskCode( void * pvParameters )
437 * // The parameter value is expected to be 1 as 1 is passed in the
438 * // pvParameters value in the call to xTaskCreateStatic().
439 * configASSERT( ( uint32_t ) pvParameters == 1UL );
443 * // Task code goes here.
447 * // Function that creates a task.
448 * void vOtherFunction( void )
450 * TaskHandle_t xHandle = NULL;
452 * // Create the task without using any dynamic memory allocation.
453 * xHandle = xTaskCreateStatic(
454 * vTaskCode, // Function that implements the task.
455 * "NAME", // Text name for the task.
456 * STACK_SIZE, // Stack size in words, not bytes.
457 * ( void * ) 1, // Parameter passed into the task.
458 * tskIDLE_PRIORITY,// Priority at which the task is created.
459 * xStack, // Array to use as the task's stack.
460 * &xTaskBuffer ); // Variable to hold the task's data structure.
462 * // puxStackBuffer and pxTaskBuffer were not NULL, so the task will have
463 * // been created, and xHandle will be the task's handle. Use the handle
464 * // to suspend the task.
465 * vTaskSuspend( xHandle );
468 * \defgroup xTaskCreateStatic xTaskCreateStatic
471 #if ( configSUPPORT_STATIC_ALLOCATION == 1 )
472 TaskHandle_t xTaskCreateStatic( TaskFunction_t pxTaskCode,
473 const char * const pcName, /*lint !e971 Unqualified char types are allowed for strings and single characters only. */
474 const uint32_t ulStackDepth,
475 void * const pvParameters,
476 UBaseType_t uxPriority,
477 StackType_t * const puxStackBuffer,
478 StaticTask_t * const pxTaskBuffer ) PRIVILEGED_FUNCTION;
479 #endif /* configSUPPORT_STATIC_ALLOCATION */
484 * BaseType_t xTaskCreateRestricted( TaskParameters_t *pxTaskDefinition, TaskHandle_t *pxCreatedTask );
487 * Only available when configSUPPORT_DYNAMIC_ALLOCATION is set to 1.
489 * xTaskCreateRestricted() should only be used in systems that include an MPU
492 * Create a new task and add it to the list of tasks that are ready to run.
493 * The function parameters define the memory regions and associated access
494 * permissions allocated to the task.
496 * See xTaskCreateRestrictedStatic() for a version that does not use any
497 * dynamic memory allocation.
499 * @param pxTaskDefinition Pointer to a structure that contains a member
500 * for each of the normal xTaskCreate() parameters (see the xTaskCreate() API
501 * documentation) plus an optional stack buffer and the memory region
504 * @param pxCreatedTask Used to pass back a handle by which the created task
507 * @return pdPASS if the task was successfully created and added to a ready
508 * list, otherwise an error code defined in the file projdefs.h
512 * // Create an TaskParameters_t structure that defines the task to be created.
513 * static const TaskParameters_t xCheckTaskParameters =
515 * vATask, // pvTaskCode - the function that implements the task.
516 * "ATask", // pcName - just a text name for the task to assist debugging.
517 * 100, // usStackDepth - the stack size DEFINED IN WORDS.
518 * NULL, // pvParameters - passed into the task function as the function parameters.
519 * ( 1UL | portPRIVILEGE_BIT ),// uxPriority - task priority, set the portPRIVILEGE_BIT if the task should run in a privileged state.
520 * cStackBuffer,// puxStackBuffer - the buffer to be used as the task stack.
522 * // xRegions - Allocate up to three separate memory regions for access by
523 * // the task, with appropriate access permissions. Different processors have
524 * // different memory alignment requirements - refer to the FreeRTOS documentation
525 * // for full information.
527 * // Base address Length Parameters
528 * { cReadWriteArray, 32, portMPU_REGION_READ_WRITE },
529 * { cReadOnlyArray, 32, portMPU_REGION_READ_ONLY },
530 * { cPrivilegedOnlyAccessArray, 128, portMPU_REGION_PRIVILEGED_READ_WRITE }
536 * TaskHandle_t xHandle;
538 * // Create a task from the const structure defined above. The task handle
539 * // is requested (the second parameter is not NULL) but in this case just for
540 * // demonstration purposes as its not actually used.
541 * xTaskCreateRestricted( &xRegTest1Parameters, &xHandle );
543 * // Start the scheduler.
544 * vTaskStartScheduler();
546 * // Will only get here if there was insufficient memory to create the idle
547 * // and/or timer task.
551 * \defgroup xTaskCreateRestricted xTaskCreateRestricted
554 #if ( portUSING_MPU_WRAPPERS == 1 )
555 BaseType_t xTaskCreateRestricted( const TaskParameters_t * const pxTaskDefinition,
556 TaskHandle_t * pxCreatedTask ) PRIVILEGED_FUNCTION;
562 * BaseType_t xTaskCreateRestrictedStatic( TaskParameters_t *pxTaskDefinition, TaskHandle_t *pxCreatedTask );
565 * Only available when configSUPPORT_STATIC_ALLOCATION is set to 1.
567 * xTaskCreateRestrictedStatic() should only be used in systems that include an
568 * MPU implementation.
570 * Internally, within the FreeRTOS implementation, tasks use two blocks of
571 * memory. The first block is used to hold the task's data structures. The
572 * second block is used by the task as its stack. If a task is created using
573 * xTaskCreateRestricted() then the stack is provided by the application writer,
574 * and the memory used to hold the task's data structure is automatically
575 * dynamically allocated inside the xTaskCreateRestricted() function. If a task
576 * is created using xTaskCreateRestrictedStatic() then the application writer
577 * must provide the memory used to hold the task's data structures too.
578 * xTaskCreateRestrictedStatic() therefore allows a memory protected task to be
579 * created without using any dynamic memory allocation.
581 * @param pxTaskDefinition Pointer to a structure that contains a member
582 * for each of the normal xTaskCreate() parameters (see the xTaskCreate() API
583 * documentation) plus an optional stack buffer and the memory region
584 * definitions. If configSUPPORT_STATIC_ALLOCATION is set to 1 the structure
585 * contains an additional member, which is used to point to a variable of type
586 * StaticTask_t - which is then used to hold the task's data structure.
588 * @param pxCreatedTask Used to pass back a handle by which the created task
591 * @return pdPASS if the task was successfully created and added to a ready
592 * list, otherwise an error code defined in the file projdefs.h
596 * // Create an TaskParameters_t structure that defines the task to be created.
597 * // The StaticTask_t variable is only included in the structure when
598 * // configSUPPORT_STATIC_ALLOCATION is set to 1. The PRIVILEGED_DATA macro can
599 * // be used to force the variable into the RTOS kernel's privileged data area.
600 * static PRIVILEGED_DATA StaticTask_t xTaskBuffer;
601 * static const TaskParameters_t xCheckTaskParameters =
603 * vATask, // pvTaskCode - the function that implements the task.
604 * "ATask", // pcName - just a text name for the task to assist debugging.
605 * 100, // usStackDepth - the stack size DEFINED IN WORDS.
606 * NULL, // pvParameters - passed into the task function as the function parameters.
607 * ( 1UL | portPRIVILEGE_BIT ),// uxPriority - task priority, set the portPRIVILEGE_BIT if the task should run in a privileged state.
608 * cStackBuffer,// puxStackBuffer - the buffer to be used as the task stack.
610 * // xRegions - Allocate up to three separate memory regions for access by
611 * // the task, with appropriate access permissions. Different processors have
612 * // different memory alignment requirements - refer to the FreeRTOS documentation
613 * // for full information.
615 * // Base address Length Parameters
616 * { cReadWriteArray, 32, portMPU_REGION_READ_WRITE },
617 * { cReadOnlyArray, 32, portMPU_REGION_READ_ONLY },
618 * { cPrivilegedOnlyAccessArray, 128, portMPU_REGION_PRIVILEGED_READ_WRITE }
621 * &xTaskBuffer; // Holds the task's data structure.
626 * TaskHandle_t xHandle;
628 * // Create a task from the const structure defined above. The task handle
629 * // is requested (the second parameter is not NULL) but in this case just for
630 * // demonstration purposes as its not actually used.
631 * xTaskCreateRestrictedStatic( &xRegTest1Parameters, &xHandle );
633 * // Start the scheduler.
634 * vTaskStartScheduler();
636 * // Will only get here if there was insufficient memory to create the idle
637 * // and/or timer task.
641 * \defgroup xTaskCreateRestrictedStatic xTaskCreateRestrictedStatic
644 #if ( ( portUSING_MPU_WRAPPERS == 1 ) && ( configSUPPORT_STATIC_ALLOCATION == 1 ) )
645 BaseType_t xTaskCreateRestrictedStatic( const TaskParameters_t * const pxTaskDefinition,
646 TaskHandle_t * pxCreatedTask ) PRIVILEGED_FUNCTION;
652 * void vTaskAllocateMPURegions( TaskHandle_t xTask, const MemoryRegion_t * const pxRegions );
655 * Memory regions are assigned to a restricted task when the task is created by
656 * a call to xTaskCreateRestricted(). These regions can be redefined using
657 * vTaskAllocateMPURegions().
659 * @param xTask The handle of the task being updated.
661 * @param xRegions A pointer to a MemoryRegion_t structure that contains the
662 * new memory region definitions.
666 * // Define an array of MemoryRegion_t structures that configures an MPU region
667 * // allowing read/write access for 1024 bytes starting at the beginning of the
668 * // ucOneKByte array. The other two of the maximum 3 definable regions are
669 * // unused so set to zero.
670 * static const MemoryRegion_t xAltRegions[ portNUM_CONFIGURABLE_REGIONS ] =
672 * // Base address Length Parameters
673 * { ucOneKByte, 1024, portMPU_REGION_READ_WRITE },
678 * void vATask( void *pvParameters )
680 * // This task was created such that it has access to certain regions of
681 * // memory as defined by the MPU configuration. At some point it is
682 * // desired that these MPU regions are replaced with that defined in the
683 * // xAltRegions const struct above. Use a call to vTaskAllocateMPURegions()
684 * // for this purpose. NULL is used as the task handle to indicate that this
685 * // function should modify the MPU regions of the calling task.
686 * vTaskAllocateMPURegions( NULL, xAltRegions );
688 * // Now the task can continue its function, but from this point on can only
689 * // access its stack and the ucOneKByte array (unless any other statically
690 * // defined or shared regions have been declared elsewhere).
693 * \defgroup vTaskAllocateMPURegions vTaskAllocateMPURegions
696 void vTaskAllocateMPURegions( TaskHandle_t xTask,
697 const MemoryRegion_t * const pxRegions ) PRIVILEGED_FUNCTION;
702 * void vTaskDelete( TaskHandle_t xTaskToDelete );
705 * INCLUDE_vTaskDelete must be defined as 1 for this function to be available.
706 * See the configuration section for more information.
708 * Remove a task from the RTOS real time kernel's management. The task being
709 * deleted will be removed from all ready, blocked, suspended and event lists.
711 * NOTE: The idle task is responsible for freeing the kernel allocated
712 * memory from tasks that have been deleted. It is therefore important that
713 * the idle task is not starved of microcontroller processing time if your
714 * application makes any calls to vTaskDelete (). Memory allocated by the
715 * task code is not automatically freed, and should be freed before the task
718 * See the demo application file death.c for sample code that utilises
721 * @param xTaskToDelete The handle of the task to be deleted. Passing NULL will
722 * cause the calling task to be deleted.
726 * void vOtherFunction( void )
728 * TaskHandle_t xHandle;
730 * // Create the task, storing the handle.
731 * xTaskCreate( vTaskCode, "NAME", STACK_SIZE, NULL, tskIDLE_PRIORITY, &xHandle );
733 * // Use the handle to delete the task.
734 * vTaskDelete( xHandle );
737 * \defgroup vTaskDelete vTaskDelete
740 void vTaskDelete( TaskHandle_t xTaskToDelete ) PRIVILEGED_FUNCTION;
742 /*-----------------------------------------------------------
744 *----------------------------------------------------------*/
749 * void vTaskDelay( const TickType_t xTicksToDelay );
752 * Delay a task for a given number of ticks. The actual time that the
753 * task remains blocked depends on the tick rate. The constant
754 * portTICK_PERIOD_MS can be used to calculate real time from the tick
755 * rate - with the resolution of one tick period.
757 * INCLUDE_vTaskDelay must be defined as 1 for this function to be available.
758 * See the configuration section for more information.
761 * vTaskDelay() specifies a time at which the task wishes to unblock relative to
762 * the time at which vTaskDelay() is called. For example, specifying a block
763 * period of 100 ticks will cause the task to unblock 100 ticks after
764 * vTaskDelay() is called. vTaskDelay() does not therefore provide a good method
765 * of controlling the frequency of a periodic task as the path taken through the
766 * code, as well as other task and interrupt activity, will affect the frequency
767 * at which vTaskDelay() gets called and therefore the time at which the task
768 * next executes. See xTaskDelayUntil() for an alternative API function designed
769 * to facilitate fixed frequency execution. It does this by specifying an
770 * absolute time (rather than a relative time) at which the calling task should
773 * @param xTicksToDelay The amount of time, in tick periods, that
774 * the calling task should block.
778 * void vTaskFunction( void * pvParameters )
780 * // Block for 500ms.
781 * const TickType_t xDelay = 500 / portTICK_PERIOD_MS;
785 * // Simply toggle the LED every 500ms, blocking between each toggle.
787 * vTaskDelay( xDelay );
791 * \defgroup vTaskDelay vTaskDelay
794 void vTaskDelay( const TickType_t xTicksToDelay ) PRIVILEGED_FUNCTION;
799 * BaseType_t xTaskDelayUntil( TickType_t *pxPreviousWakeTime, const TickType_t xTimeIncrement );
802 * INCLUDE_xTaskDelayUntil must be defined as 1 for this function to be available.
803 * See the configuration section for more information.
805 * Delay a task until a specified time. This function can be used by periodic
806 * tasks to ensure a constant execution frequency.
808 * This function differs from vTaskDelay () in one important aspect: vTaskDelay () will
809 * cause a task to block for the specified number of ticks from the time vTaskDelay () is
810 * called. It is therefore difficult to use vTaskDelay () by itself to generate a fixed
811 * execution frequency as the time between a task starting to execute and that task
812 * calling vTaskDelay () may not be fixed [the task may take a different path though the
813 * code between calls, or may get interrupted or preempted a different number of times
814 * each time it executes].
816 * Whereas vTaskDelay () specifies a wake time relative to the time at which the function
817 * is called, xTaskDelayUntil () specifies the absolute (exact) time at which it wishes to
820 * The macro pdMS_TO_TICKS() can be used to calculate the number of ticks from a
821 * time specified in milliseconds with a resolution of one tick period.
823 * @param pxPreviousWakeTime Pointer to a variable that holds the time at which the
824 * task was last unblocked. The variable must be initialised with the current time
825 * prior to its first use (see the example below). Following this the variable is
826 * automatically updated within xTaskDelayUntil ().
828 * @param xTimeIncrement The cycle time period. The task will be unblocked at
829 * time *pxPreviousWakeTime + xTimeIncrement. Calling xTaskDelayUntil with the
830 * same xTimeIncrement parameter value will cause the task to execute with
831 * a fixed interface period.
833 * @return Value which can be used to check whether the task was actually delayed.
834 * Will be pdTRUE if the task way delayed and pdFALSE otherwise. A task will not
835 * be delayed if the next expected wake time is in the past.
839 * // Perform an action every 10 ticks.
840 * void vTaskFunction( void * pvParameters )
842 * TickType_t xLastWakeTime;
843 * const TickType_t xFrequency = 10;
844 * BaseType_t xWasDelayed;
846 * // Initialise the xLastWakeTime variable with the current time.
847 * xLastWakeTime = xTaskGetTickCount ();
850 * // Wait for the next cycle.
851 * xWasDelayed = xTaskDelayUntil( &xLastWakeTime, xFrequency );
853 * // Perform action here. xWasDelayed value can be used to determine
854 * // whether a deadline was missed if the code here took too long.
858 * \defgroup xTaskDelayUntil xTaskDelayUntil
861 BaseType_t xTaskDelayUntil( TickType_t * const pxPreviousWakeTime,
862 const TickType_t xTimeIncrement ) PRIVILEGED_FUNCTION;
865 * vTaskDelayUntil() is the older version of xTaskDelayUntil() and does not
868 #define vTaskDelayUntil( pxPreviousWakeTime, xTimeIncrement ) \
870 ( void ) xTaskDelayUntil( ( pxPreviousWakeTime ), ( xTimeIncrement ) ); \
877 * BaseType_t xTaskAbortDelay( TaskHandle_t xTask );
880 * INCLUDE_xTaskAbortDelay must be defined as 1 in FreeRTOSConfig.h for this
881 * function to be available.
883 * A task will enter the Blocked state when it is waiting for an event. The
884 * event it is waiting for can be a temporal event (waiting for a time), such
885 * as when vTaskDelay() is called, or an event on an object, such as when
886 * xQueueReceive() or ulTaskNotifyTake() is called. If the handle of a task
887 * that is in the Blocked state is used in a call to xTaskAbortDelay() then the
888 * task will leave the Blocked state, and return from whichever function call
889 * placed the task into the Blocked state.
891 * There is no 'FromISR' version of this function as an interrupt would need to
892 * know which object a task was blocked on in order to know which actions to
893 * take. For example, if the task was blocked on a queue the interrupt handler
894 * would then need to know if the queue was locked.
896 * @param xTask The handle of the task to remove from the Blocked state.
898 * @return If the task referenced by xTask was not in the Blocked state then
899 * pdFAIL is returned. Otherwise pdPASS is returned.
901 * \defgroup xTaskAbortDelay xTaskAbortDelay
904 BaseType_t xTaskAbortDelay( TaskHandle_t xTask ) PRIVILEGED_FUNCTION;
909 * UBaseType_t uxTaskPriorityGet( const TaskHandle_t xTask );
912 * INCLUDE_uxTaskPriorityGet must be defined as 1 for this function to be available.
913 * See the configuration section for more information.
915 * Obtain the priority of any task.
917 * @param xTask Handle of the task to be queried. Passing a NULL
918 * handle results in the priority of the calling task being returned.
920 * @return The priority of xTask.
924 * void vAFunction( void )
926 * TaskHandle_t xHandle;
928 * // Create a task, storing the handle.
929 * xTaskCreate( vTaskCode, "NAME", STACK_SIZE, NULL, tskIDLE_PRIORITY, &xHandle );
933 * // Use the handle to obtain the priority of the created task.
934 * // It was created with tskIDLE_PRIORITY, but may have changed
936 * if( uxTaskPriorityGet( xHandle ) != tskIDLE_PRIORITY )
938 * // The task has changed it's priority.
943 * // Is our priority higher than the created task?
944 * if( uxTaskPriorityGet( xHandle ) < uxTaskPriorityGet( NULL ) )
946 * // Our priority (obtained using NULL handle) is higher.
950 * \defgroup uxTaskPriorityGet uxTaskPriorityGet
953 UBaseType_t uxTaskPriorityGet( const TaskHandle_t xTask ) PRIVILEGED_FUNCTION;
958 * UBaseType_t uxTaskPriorityGetFromISR( const TaskHandle_t xTask );
961 * A version of uxTaskPriorityGet() that can be used from an ISR.
963 UBaseType_t uxTaskPriorityGetFromISR( const TaskHandle_t xTask ) PRIVILEGED_FUNCTION;
968 * eTaskState eTaskGetState( TaskHandle_t xTask );
971 * INCLUDE_eTaskGetState must be defined as 1 for this function to be available.
972 * See the configuration section for more information.
974 * Obtain the state of any task. States are encoded by the eTaskState
977 * @param xTask Handle of the task to be queried.
979 * @return The state of xTask at the time the function was called. Note the
980 * state of the task might change between the function being called, and the
981 * functions return value being tested by the calling task.
983 eTaskState eTaskGetState( TaskHandle_t xTask ) PRIVILEGED_FUNCTION;
988 * void vTaskGetInfo( TaskHandle_t xTask, TaskStatus_t *pxTaskStatus, BaseType_t xGetFreeStackSpace, eTaskState eState );
991 * configUSE_TRACE_FACILITY must be defined as 1 for this function to be
992 * available. See the configuration section for more information.
994 * Populates a TaskStatus_t structure with information about a task.
996 * @param xTask Handle of the task being queried. If xTask is NULL then
997 * information will be returned about the calling task.
999 * @param pxTaskStatus A pointer to the TaskStatus_t structure that will be
1000 * filled with information about the task referenced by the handle passed using
1001 * the xTask parameter.
1003 * @param xGetFreeStackSpace The TaskStatus_t structure contains a member to report
1004 * the stack high water mark of the task being queried. Calculating the stack
1005 * high water mark takes a relatively long time, and can make the system
1006 * temporarily unresponsive - so the xGetFreeStackSpace parameter is provided to
1007 * allow the high water mark checking to be skipped. The high watermark value
1008 * will only be written to the TaskStatus_t structure if xGetFreeStackSpace is
1009 * not set to pdFALSE;
1011 * @param eState The TaskStatus_t structure contains a member to report the
1012 * state of the task being queried. Obtaining the task state is not as fast as
1013 * a simple assignment - so the eState parameter is provided to allow the state
1014 * information to be omitted from the TaskStatus_t structure. To obtain state
1015 * information then set eState to eInvalid - otherwise the value passed in
1016 * eState will be reported as the task state in the TaskStatus_t structure.
1020 * void vAFunction( void )
1022 * TaskHandle_t xHandle;
1023 * TaskStatus_t xTaskDetails;
1025 * // Obtain the handle of a task from its name.
1026 * xHandle = xTaskGetHandle( "Task_Name" );
1028 * // Check the handle is not NULL.
1029 * configASSERT( xHandle );
1031 * // Use the handle to obtain further information about the task.
1032 * vTaskGetInfo( xHandle,
1034 * pdTRUE, // Include the high water mark in xTaskDetails.
1035 * eInvalid ); // Include the task state in xTaskDetails.
1038 * \defgroup vTaskGetInfo vTaskGetInfo
1041 void vTaskGetInfo( TaskHandle_t xTask,
1042 TaskStatus_t * pxTaskStatus,
1043 BaseType_t xGetFreeStackSpace,
1044 eTaskState eState ) PRIVILEGED_FUNCTION;
1049 * void vTaskPrioritySet( TaskHandle_t xTask, UBaseType_t uxNewPriority );
1052 * INCLUDE_vTaskPrioritySet must be defined as 1 for this function to be available.
1053 * See the configuration section for more information.
1055 * Set the priority of any task.
1057 * A context switch will occur before the function returns if the priority
1058 * being set is higher than the currently executing task.
1060 * @param xTask Handle to the task for which the priority is being set.
1061 * Passing a NULL handle results in the priority of the calling task being set.
1063 * @param uxNewPriority The priority to which the task will be set.
1067 * void vAFunction( void )
1069 * TaskHandle_t xHandle;
1071 * // Create a task, storing the handle.
1072 * xTaskCreate( vTaskCode, "NAME", STACK_SIZE, NULL, tskIDLE_PRIORITY, &xHandle );
1076 * // Use the handle to raise the priority of the created task.
1077 * vTaskPrioritySet( xHandle, tskIDLE_PRIORITY + 1 );
1081 * // Use a NULL handle to raise our priority to the same value.
1082 * vTaskPrioritySet( NULL, tskIDLE_PRIORITY + 1 );
1085 * \defgroup vTaskPrioritySet vTaskPrioritySet
1088 void vTaskPrioritySet( TaskHandle_t xTask,
1089 UBaseType_t uxNewPriority ) PRIVILEGED_FUNCTION;
1094 * void vTaskSuspend( TaskHandle_t xTaskToSuspend );
1097 * INCLUDE_vTaskSuspend must be defined as 1 for this function to be available.
1098 * See the configuration section for more information.
1100 * Suspend any task. When suspended a task will never get any microcontroller
1101 * processing time, no matter what its priority.
1103 * Calls to vTaskSuspend are not accumulative -
1104 * i.e. calling vTaskSuspend () twice on the same task still only requires one
1105 * call to vTaskResume () to ready the suspended task.
1107 * @param xTaskToSuspend Handle to the task being suspended. Passing a NULL
1108 * handle will cause the calling task to be suspended.
1112 * void vAFunction( void )
1114 * TaskHandle_t xHandle;
1116 * // Create a task, storing the handle.
1117 * xTaskCreate( vTaskCode, "NAME", STACK_SIZE, NULL, tskIDLE_PRIORITY, &xHandle );
1121 * // Use the handle to suspend the created task.
1122 * vTaskSuspend( xHandle );
1126 * // The created task will not run during this period, unless
1127 * // another task calls vTaskResume( xHandle ).
1132 * // Suspend ourselves.
1133 * vTaskSuspend( NULL );
1135 * // We cannot get here unless another task calls vTaskResume
1136 * // with our handle as the parameter.
1139 * \defgroup vTaskSuspend vTaskSuspend
1142 void vTaskSuspend( TaskHandle_t xTaskToSuspend ) PRIVILEGED_FUNCTION;
1147 * void vTaskResume( TaskHandle_t xTaskToResume );
1150 * INCLUDE_vTaskSuspend must be defined as 1 for this function to be available.
1151 * See the configuration section for more information.
1153 * Resumes a suspended task.
1155 * A task that has been suspended by one or more calls to vTaskSuspend ()
1156 * will be made available for running again by a single call to
1159 * @param xTaskToResume Handle to the task being readied.
1163 * void vAFunction( void )
1165 * TaskHandle_t xHandle;
1167 * // Create a task, storing the handle.
1168 * xTaskCreate( vTaskCode, "NAME", STACK_SIZE, NULL, tskIDLE_PRIORITY, &xHandle );
1172 * // Use the handle to suspend the created task.
1173 * vTaskSuspend( xHandle );
1177 * // The created task will not run during this period, unless
1178 * // another task calls vTaskResume( xHandle ).
1183 * // Resume the suspended task ourselves.
1184 * vTaskResume( xHandle );
1186 * // The created task will once again get microcontroller processing
1187 * // time in accordance with its priority within the system.
1190 * \defgroup vTaskResume vTaskResume
1193 void vTaskResume( TaskHandle_t xTaskToResume ) PRIVILEGED_FUNCTION;
1198 * void xTaskResumeFromISR( TaskHandle_t xTaskToResume );
1201 * INCLUDE_xTaskResumeFromISR must be defined as 1 for this function to be
1202 * available. See the configuration section for more information.
1204 * An implementation of vTaskResume() that can be called from within an ISR.
1206 * A task that has been suspended by one or more calls to vTaskSuspend ()
1207 * will be made available for running again by a single call to
1208 * xTaskResumeFromISR ().
1210 * xTaskResumeFromISR() should not be used to synchronise a task with an
1211 * interrupt if there is a chance that the interrupt could arrive prior to the
1212 * task being suspended - as this can lead to interrupts being missed. Use of a
1213 * semaphore as a synchronisation mechanism would avoid this eventuality.
1215 * @param xTaskToResume Handle to the task being readied.
1217 * @return pdTRUE if resuming the task should result in a context switch,
1218 * otherwise pdFALSE. This is used by the ISR to determine if a context switch
1219 * may be required following the ISR.
1221 * \defgroup vTaskResumeFromISR vTaskResumeFromISR
1224 BaseType_t xTaskResumeFromISR( TaskHandle_t xTaskToResume ) PRIVILEGED_FUNCTION;
1226 /*-----------------------------------------------------------
1228 *----------------------------------------------------------*/
1233 * void vTaskStartScheduler( void );
1236 * Starts the real time kernel tick processing. After calling the kernel
1237 * has control over which tasks are executed and when.
1239 * See the demo application file main.c for an example of creating
1240 * tasks and starting the kernel.
1244 * void vAFunction( void )
1246 * // Create at least one task before starting the kernel.
1247 * xTaskCreate( vTaskCode, "NAME", STACK_SIZE, NULL, tskIDLE_PRIORITY, NULL );
1249 * // Start the real time kernel with preemption.
1250 * vTaskStartScheduler ();
1252 * // Will not get here unless a task calls vTaskEndScheduler ()
1256 * \defgroup vTaskStartScheduler vTaskStartScheduler
1257 * \ingroup SchedulerControl
1259 void vTaskStartScheduler( void ) PRIVILEGED_FUNCTION;
1264 * void vTaskEndScheduler( void );
1267 * NOTE: At the time of writing only the x86 real mode port, which runs on a PC
1268 * in place of DOS, implements this function.
1270 * Stops the real time kernel tick. All created tasks will be automatically
1271 * deleted and multitasking (either preemptive or cooperative) will
1272 * stop. Execution then resumes from the point where vTaskStartScheduler ()
1273 * was called, as if vTaskStartScheduler () had just returned.
1275 * See the demo application file main. c in the demo/PC directory for an
1276 * example that uses vTaskEndScheduler ().
1278 * vTaskEndScheduler () requires an exit function to be defined within the
1279 * portable layer (see vPortEndScheduler () in port. c for the PC port). This
1280 * performs hardware specific operations such as stopping the kernel tick.
1282 * vTaskEndScheduler () will cause all of the resources allocated by the
1283 * kernel to be freed - but will not free resources allocated by application
1288 * void vTaskCode( void * pvParameters )
1292 * // Task code goes here.
1294 * // At some point we want to end the real time kernel processing
1296 * vTaskEndScheduler ();
1300 * void vAFunction( void )
1302 * // Create at least one task before starting the kernel.
1303 * xTaskCreate( vTaskCode, "NAME", STACK_SIZE, NULL, tskIDLE_PRIORITY, NULL );
1305 * // Start the real time kernel with preemption.
1306 * vTaskStartScheduler ();
1308 * // Will only get here when the vTaskCode () task has called
1309 * // vTaskEndScheduler (). When we get here we are back to single task
1314 * \defgroup vTaskEndScheduler vTaskEndScheduler
1315 * \ingroup SchedulerControl
1317 void vTaskEndScheduler( void ) PRIVILEGED_FUNCTION;
1322 * void vTaskSuspendAll( void );
1325 * Suspends the scheduler without disabling interrupts. Context switches will
1326 * not occur while the scheduler is suspended.
1328 * After calling vTaskSuspendAll () the calling task will continue to execute
1329 * without risk of being swapped out until a call to xTaskResumeAll () has been
1332 * API functions that have the potential to cause a context switch (for example,
1333 * xTaskDelayUntil(), xQueueSend(), etc.) must not be called while the scheduler
1338 * void vTask1( void * pvParameters )
1342 * // Task code goes here.
1346 * // At some point the task wants to perform a long operation during
1347 * // which it does not want to get swapped out. It cannot use
1348 * // taskENTER_CRITICAL ()/taskEXIT_CRITICAL () as the length of the
1349 * // operation may cause interrupts to be missed - including the
1352 * // Prevent the real time kernel swapping out the task.
1353 * vTaskSuspendAll ();
1355 * // Perform the operation here. There is no need to use critical
1356 * // sections as we have all the microcontroller processing time.
1357 * // During this time interrupts will still operate and the kernel
1358 * // tick count will be maintained.
1362 * // The operation is complete. Restart the kernel.
1363 * xTaskResumeAll ();
1367 * \defgroup vTaskSuspendAll vTaskSuspendAll
1368 * \ingroup SchedulerControl
1370 void vTaskSuspendAll( void ) PRIVILEGED_FUNCTION;
1375 * BaseType_t xTaskResumeAll( void );
1378 * Resumes scheduler activity after it was suspended by a call to
1379 * vTaskSuspendAll().
1381 * xTaskResumeAll() only resumes the scheduler. It does not unsuspend tasks
1382 * that were previously suspended by a call to vTaskSuspend().
1384 * @return If resuming the scheduler caused a context switch then pdTRUE is
1385 * returned, otherwise pdFALSE is returned.
1389 * void vTask1( void * pvParameters )
1393 * // Task code goes here.
1397 * // At some point the task wants to perform a long operation during
1398 * // which it does not want to get swapped out. It cannot use
1399 * // taskENTER_CRITICAL ()/taskEXIT_CRITICAL () as the length of the
1400 * // operation may cause interrupts to be missed - including the
1403 * // Prevent the real time kernel swapping out the task.
1404 * vTaskSuspendAll ();
1406 * // Perform the operation here. There is no need to use critical
1407 * // sections as we have all the microcontroller processing time.
1408 * // During this time interrupts will still operate and the real
1409 * // time kernel tick count will be maintained.
1413 * // The operation is complete. Restart the kernel. We want to force
1414 * // a context switch - but there is no point if resuming the scheduler
1415 * // caused a context switch already.
1416 * if( !xTaskResumeAll () )
1423 * \defgroup xTaskResumeAll xTaskResumeAll
1424 * \ingroup SchedulerControl
1426 BaseType_t xTaskResumeAll( void ) PRIVILEGED_FUNCTION;
1428 /*-----------------------------------------------------------
1430 *----------------------------------------------------------*/
1435 * TickType_t xTaskGetTickCount( void );
1438 * @return The count of ticks since vTaskStartScheduler was called.
1440 * \defgroup xTaskGetTickCount xTaskGetTickCount
1441 * \ingroup TaskUtils
1443 TickType_t xTaskGetTickCount( void ) PRIVILEGED_FUNCTION;
1448 * TickType_t xTaskGetTickCountFromISR( void );
1451 * @return The count of ticks since vTaskStartScheduler was called.
1453 * This is a version of xTaskGetTickCount() that is safe to be called from an
1454 * ISR - provided that TickType_t is the natural word size of the
1455 * microcontroller being used or interrupt nesting is either not supported or
1458 * \defgroup xTaskGetTickCountFromISR xTaskGetTickCountFromISR
1459 * \ingroup TaskUtils
1461 TickType_t xTaskGetTickCountFromISR( void ) PRIVILEGED_FUNCTION;
1466 * uint16_t uxTaskGetNumberOfTasks( void );
1469 * @return The number of tasks that the real time kernel is currently managing.
1470 * This includes all ready, blocked and suspended tasks. A task that
1471 * has been deleted but not yet freed by the idle task will also be
1472 * included in the count.
1474 * \defgroup uxTaskGetNumberOfTasks uxTaskGetNumberOfTasks
1475 * \ingroup TaskUtils
1477 UBaseType_t uxTaskGetNumberOfTasks( void ) PRIVILEGED_FUNCTION;
1482 * char *pcTaskGetName( TaskHandle_t xTaskToQuery );
1485 * @return The text (human readable) name of the task referenced by the handle
1486 * xTaskToQuery. A task can query its own name by either passing in its own
1487 * handle, or by setting xTaskToQuery to NULL.
1489 * \defgroup pcTaskGetName pcTaskGetName
1490 * \ingroup TaskUtils
1492 char * pcTaskGetName( TaskHandle_t xTaskToQuery ) PRIVILEGED_FUNCTION; /*lint !e971 Unqualified char types are allowed for strings and single characters only. */
1497 * TaskHandle_t xTaskGetHandle( const char *pcNameToQuery );
1500 * NOTE: This function takes a relatively long time to complete and should be
1503 * @return The handle of the task that has the human readable name pcNameToQuery.
1504 * NULL is returned if no matching name is found. INCLUDE_xTaskGetHandle
1505 * must be set to 1 in FreeRTOSConfig.h for pcTaskGetHandle() to be available.
1507 * \defgroup pcTaskGetHandle pcTaskGetHandle
1508 * \ingroup TaskUtils
1510 TaskHandle_t xTaskGetHandle( const char * pcNameToQuery ) PRIVILEGED_FUNCTION; /*lint !e971 Unqualified char types are allowed for strings and single characters only. */
1515 * UBaseType_t uxTaskGetStackHighWaterMark( TaskHandle_t xTask );
1518 * INCLUDE_uxTaskGetStackHighWaterMark must be set to 1 in FreeRTOSConfig.h for
1519 * this function to be available.
1521 * Returns the high water mark of the stack associated with xTask. That is,
1522 * the minimum free stack space there has been (in words, so on a 32 bit machine
1523 * a value of 1 means 4 bytes) since the task started. The smaller the returned
1524 * number the closer the task has come to overflowing its stack.
1526 * uxTaskGetStackHighWaterMark() and uxTaskGetStackHighWaterMark2() are the
1527 * same except for their return type. Using configSTACK_DEPTH_TYPE allows the
1528 * user to determine the return type. It gets around the problem of the value
1529 * overflowing on 8-bit types without breaking backward compatibility for
1530 * applications that expect an 8-bit return type.
1532 * @param xTask Handle of the task associated with the stack to be checked.
1533 * Set xTask to NULL to check the stack of the calling task.
1535 * @return The smallest amount of free stack space there has been (in words, so
1536 * actual spaces on the stack rather than bytes) since the task referenced by
1537 * xTask was created.
1539 UBaseType_t uxTaskGetStackHighWaterMark( TaskHandle_t xTask ) PRIVILEGED_FUNCTION;
1544 * configSTACK_DEPTH_TYPE uxTaskGetStackHighWaterMark2( TaskHandle_t xTask );
1547 * INCLUDE_uxTaskGetStackHighWaterMark2 must be set to 1 in FreeRTOSConfig.h for
1548 * this function to be available.
1550 * Returns the high water mark of the stack associated with xTask. That is,
1551 * the minimum free stack space there has been (in words, so on a 32 bit machine
1552 * a value of 1 means 4 bytes) since the task started. The smaller the returned
1553 * number the closer the task has come to overflowing its stack.
1555 * uxTaskGetStackHighWaterMark() and uxTaskGetStackHighWaterMark2() are the
1556 * same except for their return type. Using configSTACK_DEPTH_TYPE allows the
1557 * user to determine the return type. It gets around the problem of the value
1558 * overflowing on 8-bit types without breaking backward compatibility for
1559 * applications that expect an 8-bit return type.
1561 * @param xTask Handle of the task associated with the stack to be checked.
1562 * Set xTask to NULL to check the stack of the calling task.
1564 * @return The smallest amount of free stack space there has been (in words, so
1565 * actual spaces on the stack rather than bytes) since the task referenced by
1566 * xTask was created.
1568 configSTACK_DEPTH_TYPE uxTaskGetStackHighWaterMark2( TaskHandle_t xTask ) PRIVILEGED_FUNCTION;
1570 /* When using trace macros it is sometimes necessary to include task.h before
1571 * FreeRTOS.h. When this is done TaskHookFunction_t will not yet have been defined,
1572 * so the following two prototypes will cause a compilation error. This can be
1573 * fixed by simply guarding against the inclusion of these two prototypes unless
1574 * they are explicitly required by the configUSE_APPLICATION_TASK_TAG configuration
1576 #ifdef configUSE_APPLICATION_TASK_TAG
1577 #if configUSE_APPLICATION_TASK_TAG == 1
1582 * void vTaskSetApplicationTaskTag( TaskHandle_t xTask, TaskHookFunction_t pxHookFunction );
1585 * Sets pxHookFunction to be the task hook function used by the task xTask.
1586 * Passing xTask as NULL has the effect of setting the calling tasks hook
1589 void vTaskSetApplicationTaskTag( TaskHandle_t xTask,
1590 TaskHookFunction_t pxHookFunction ) PRIVILEGED_FUNCTION;
1595 * void xTaskGetApplicationTaskTag( TaskHandle_t xTask );
1598 * Returns the pxHookFunction value assigned to the task xTask. Do not
1599 * call from an interrupt service routine - call
1600 * xTaskGetApplicationTaskTagFromISR() instead.
1602 TaskHookFunction_t xTaskGetApplicationTaskTag( TaskHandle_t xTask ) PRIVILEGED_FUNCTION;
1607 * void xTaskGetApplicationTaskTagFromISR( TaskHandle_t xTask );
1610 * Returns the pxHookFunction value assigned to the task xTask. Can
1611 * be called from an interrupt service routine.
1613 TaskHookFunction_t xTaskGetApplicationTaskTagFromISR( TaskHandle_t xTask ) PRIVILEGED_FUNCTION;
1614 #endif /* configUSE_APPLICATION_TASK_TAG ==1 */
1615 #endif /* ifdef configUSE_APPLICATION_TASK_TAG */
1617 #if ( configNUM_THREAD_LOCAL_STORAGE_POINTERS > 0 )
1619 /* Each task contains an array of pointers that is dimensioned by the
1620 * configNUM_THREAD_LOCAL_STORAGE_POINTERS setting in FreeRTOSConfig.h. The
1621 * kernel does not use the pointers itself, so the application writer can use
1622 * the pointers for any purpose they wish. The following two functions are
1623 * used to set and query a pointer respectively. */
1624 void vTaskSetThreadLocalStoragePointer( TaskHandle_t xTaskToSet,
1626 void * pvValue ) PRIVILEGED_FUNCTION;
1627 void * pvTaskGetThreadLocalStoragePointer( TaskHandle_t xTaskToQuery,
1628 BaseType_t xIndex ) PRIVILEGED_FUNCTION;
1632 #if ( configCHECK_FOR_STACK_OVERFLOW > 0 )
1637 * void vApplicationStackOverflowHook( TaskHandle_t xTask char *pcTaskName);
1640 * The application stack overflow hook is called when a stack overflow is detected for a task.
1642 * Details on stack overflow detection can be found here: https://www.FreeRTOS.org/Stacks-and-stack-overflow-checking.html
1644 * @param xTask the task that just exceeded its stack boundaries.
1645 * @param pcTaskName A character string containing the name of the offending task.
1647 void vApplicationStackOverflowHook( TaskHandle_t xTask,
1648 char * pcTaskName );
1652 #if ( configUSE_IDLE_HOOK == 1 )
1657 * void vApplicationIdleHook( void );
1660 * The application idle hook is called by the idle task.
1661 * This allows the application designer to add background functionality without
1662 * the overhead of a separate task.
1663 * NOTE: vApplicationIdleHook() MUST NOT, UNDER ANY CIRCUMSTANCES, CALL A FUNCTION THAT MIGHT BLOCK.
1665 void vApplicationIdleHook( void );
1670 #if ( configUSE_TICK_HOOK > 0 )
1675 * void vApplicationTickHook( void );
1678 * This hook function is called in the system tick handler after any OS work is completed.
1680 void vApplicationTickHook( void ); /*lint !e526 Symbol not defined as it is an application callback. */
1684 #if ( configSUPPORT_STATIC_ALLOCATION == 1 )
1689 * void vApplicationGetIdleTaskMemory( StaticTask_t ** ppxIdleTaskTCBBuffer, StackType_t ** ppxIdleTaskStackBuffer, uint32_t *pulIdleTaskStackSize )
1692 * 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
1693 * configSUPPORT_STATIC_ALLOCATION is set. For more information see this URI: https://www.FreeRTOS.org/a00110.html#configSUPPORT_STATIC_ALLOCATION
1695 * @param ppxIdleTaskTCBBuffer A handle to a statically allocated TCB buffer
1696 * @param ppxIdleTaskStackBuffer A handle to a statically allocated Stack buffer for the idle task
1697 * @param pulIdleTaskStackSize A pointer to the number of elements that will fit in the allocated stack buffer
1699 void vApplicationGetIdleTaskMemory( StaticTask_t ** ppxIdleTaskTCBBuffer,
1700 StackType_t ** ppxIdleTaskStackBuffer,
1701 uint32_t * pulIdleTaskStackSize ); /*lint !e526 Symbol not defined as it is an application callback. */
1707 * BaseType_t xTaskCallApplicationTaskHook( TaskHandle_t xTask, void *pvParameter );
1710 * Calls the hook function associated with xTask. Passing xTask as NULL has
1711 * the effect of calling the Running tasks (the calling task) hook function.
1713 * pvParameter is passed to the hook function for the task to interpret as it
1714 * wants. The return value is the value returned by the task hook function
1715 * registered by the user.
1717 BaseType_t xTaskCallApplicationTaskHook( TaskHandle_t xTask,
1718 void * pvParameter ) PRIVILEGED_FUNCTION;
1721 * xTaskGetIdleTaskHandle() is only available if
1722 * INCLUDE_xTaskGetIdleTaskHandle is set to 1 in FreeRTOSConfig.h.
1724 * Simply returns the handle of the idle task. It is not valid to call
1725 * xTaskGetIdleTaskHandle() before the scheduler has been started.
1727 TaskHandle_t xTaskGetIdleTaskHandle( void ) PRIVILEGED_FUNCTION;
1730 * configUSE_TRACE_FACILITY must be defined as 1 in FreeRTOSConfig.h for
1731 * uxTaskGetSystemState() to be available.
1733 * uxTaskGetSystemState() populates an TaskStatus_t structure for each task in
1734 * the system. TaskStatus_t structures contain, among other things, members
1735 * for the task handle, task name, task priority, task state, and total amount
1736 * of run time consumed by the task. See the TaskStatus_t structure
1737 * definition in this file for the full member list.
1739 * NOTE: This function is intended for debugging use only as its use results in
1740 * the scheduler remaining suspended for an extended period.
1742 * @param pxTaskStatusArray A pointer to an array of TaskStatus_t structures.
1743 * The array must contain at least one TaskStatus_t structure for each task
1744 * that is under the control of the RTOS. The number of tasks under the control
1745 * of the RTOS can be determined using the uxTaskGetNumberOfTasks() API function.
1747 * @param uxArraySize The size of the array pointed to by the pxTaskStatusArray
1748 * parameter. The size is specified as the number of indexes in the array, or
1749 * the number of TaskStatus_t structures contained in the array, not by the
1750 * number of bytes in the array.
1752 * @param pulTotalRunTime If configGENERATE_RUN_TIME_STATS is set to 1 in
1753 * FreeRTOSConfig.h then *pulTotalRunTime is set by uxTaskGetSystemState() to the
1754 * total run time (as defined by the run time stats clock, see
1755 * https://www.FreeRTOS.org/rtos-run-time-stats.html) since the target booted.
1756 * pulTotalRunTime can be set to NULL to omit the total run time information.
1758 * @return The number of TaskStatus_t structures that were populated by
1759 * uxTaskGetSystemState(). This should equal the number returned by the
1760 * uxTaskGetNumberOfTasks() API function, but will be zero if the value passed
1761 * in the uxArraySize parameter was too small.
1765 * // This example demonstrates how a human readable table of run time stats
1766 * // information is generated from raw data provided by uxTaskGetSystemState().
1767 * // The human readable table is written to pcWriteBuffer
1768 * void vTaskGetRunTimeStats( char *pcWriteBuffer )
1770 * TaskStatus_t *pxTaskStatusArray;
1771 * volatile UBaseType_t uxArraySize, x;
1772 * configRUN_TIME_COUNTER_TYPE ulTotalRunTime, ulStatsAsPercentage;
1774 * // Make sure the write buffer does not contain a string.
1775 * pcWriteBuffer = 0x00;
1777 * // Take a snapshot of the number of tasks in case it changes while this
1778 * // function is executing.
1779 * uxArraySize = uxTaskGetNumberOfTasks();
1781 * // Allocate a TaskStatus_t structure for each task. An array could be
1782 * // allocated statically at compile time.
1783 * pxTaskStatusArray = pvPortMalloc( uxArraySize * sizeof( TaskStatus_t ) );
1785 * if( pxTaskStatusArray != NULL )
1787 * // Generate raw status information about each task.
1788 * uxArraySize = uxTaskGetSystemState( pxTaskStatusArray, uxArraySize, &ulTotalRunTime );
1790 * // For percentage calculations.
1791 * ulTotalRunTime /= 100UL;
1793 * // Avoid divide by zero errors.
1794 * if( ulTotalRunTime > 0 )
1796 * // For each populated position in the pxTaskStatusArray array,
1797 * // format the raw data as human readable ASCII data
1798 * for( x = 0; x < uxArraySize; x++ )
1800 * // What percentage of the total run time has the task used?
1801 * // This will always be rounded down to the nearest integer.
1802 * // ulTotalRunTimeDiv100 has already been divided by 100.
1803 * ulStatsAsPercentage = pxTaskStatusArray[ x ].ulRunTimeCounter / ulTotalRunTime;
1805 * if( ulStatsAsPercentage > 0UL )
1807 * sprintf( pcWriteBuffer, "%s\t\t%lu\t\t%lu%%\r\n", pxTaskStatusArray[ x ].pcTaskName, pxTaskStatusArray[ x ].ulRunTimeCounter, ulStatsAsPercentage );
1811 * // If the percentage is zero here then the task has
1812 * // consumed less than 1% of the total run time.
1813 * sprintf( pcWriteBuffer, "%s\t\t%lu\t\t<1%%\r\n", pxTaskStatusArray[ x ].pcTaskName, pxTaskStatusArray[ x ].ulRunTimeCounter );
1816 * pcWriteBuffer += strlen( ( char * ) pcWriteBuffer );
1820 * // The array is no longer needed, free the memory it consumes.
1821 * vPortFree( pxTaskStatusArray );
1826 UBaseType_t uxTaskGetSystemState( TaskStatus_t * const pxTaskStatusArray,
1827 const UBaseType_t uxArraySize,
1828 configRUN_TIME_COUNTER_TYPE * const pulTotalRunTime ) PRIVILEGED_FUNCTION;
1833 * void vTaskList( char *pcWriteBuffer );
1836 * configUSE_TRACE_FACILITY and configUSE_STATS_FORMATTING_FUNCTIONS must
1837 * both be defined as 1 for this function to be available. See the
1838 * configuration section of the FreeRTOS.org website for more information.
1840 * NOTE 1: This function will disable interrupts for its duration. It is
1841 * not intended for normal application runtime use but as a debug aid.
1843 * Lists all the current tasks, along with their current state and stack
1844 * usage high water mark.
1846 * Tasks are reported as blocked ('B'), ready ('R'), deleted ('D') or
1851 * This function is provided for convenience only, and is used by many of the
1852 * demo applications. Do not consider it to be part of the scheduler.
1854 * vTaskList() calls uxTaskGetSystemState(), then formats part of the
1855 * uxTaskGetSystemState() output into a human readable table that displays task:
1856 * names, states, priority, stack usage and task number.
1857 * Stack usage specified as the number of unused StackType_t words stack can hold
1858 * on top of stack - not the number of bytes.
1860 * vTaskList() has a dependency on the sprintf() C library function that might
1861 * bloat the code size, use a lot of stack, and provide different results on
1862 * different platforms. An alternative, tiny, third party, and limited
1863 * functionality implementation of sprintf() is provided in many of the
1864 * FreeRTOS/Demo sub-directories in a file called printf-stdarg.c (note
1865 * printf-stdarg.c does not provide a full snprintf() implementation!).
1867 * It is recommended that production systems call uxTaskGetSystemState()
1868 * directly to get access to raw stats data, rather than indirectly through a
1869 * call to vTaskList().
1871 * @param pcWriteBuffer A buffer into which the above mentioned details
1872 * will be written, in ASCII form. This buffer is assumed to be large
1873 * enough to contain the generated report. Approximately 40 bytes per
1874 * task should be sufficient.
1876 * \defgroup vTaskList vTaskList
1877 * \ingroup TaskUtils
1879 void vTaskList( char * pcWriteBuffer ) PRIVILEGED_FUNCTION; /*lint !e971 Unqualified char types are allowed for strings and single characters only. */
1884 * void vTaskGetRunTimeStats( char *pcWriteBuffer );
1887 * configGENERATE_RUN_TIME_STATS and configUSE_STATS_FORMATTING_FUNCTIONS
1888 * must both be defined as 1 for this function to be available. The application
1889 * must also then provide definitions for
1890 * portCONFIGURE_TIMER_FOR_RUN_TIME_STATS() and portGET_RUN_TIME_COUNTER_VALUE()
1891 * to configure a peripheral timer/counter and return the timers current count
1892 * value respectively. The counter should be at least 10 times the frequency of
1895 * NOTE 1: This function will disable interrupts for its duration. It is
1896 * not intended for normal application runtime use but as a debug aid.
1898 * Setting configGENERATE_RUN_TIME_STATS to 1 will result in a total
1899 * accumulated execution time being stored for each task. The resolution
1900 * of the accumulated time value depends on the frequency of the timer
1901 * configured by the portCONFIGURE_TIMER_FOR_RUN_TIME_STATS() macro.
1902 * Calling vTaskGetRunTimeStats() writes the total execution time of each
1903 * task into a buffer, both as an absolute count value and as a percentage
1904 * of the total system execution time.
1908 * This function is provided for convenience only, and is used by many of the
1909 * demo applications. Do not consider it to be part of the scheduler.
1911 * vTaskGetRunTimeStats() calls uxTaskGetSystemState(), then formats part of the
1912 * uxTaskGetSystemState() output into a human readable table that displays the
1913 * amount of time each task has spent in the Running state in both absolute and
1916 * vTaskGetRunTimeStats() has a dependency on the sprintf() C library function
1917 * that might bloat the code size, use a lot of stack, and provide different
1918 * results on different platforms. An alternative, tiny, third party, and
1919 * limited functionality implementation of sprintf() is provided in many of the
1920 * FreeRTOS/Demo sub-directories in a file called printf-stdarg.c (note
1921 * printf-stdarg.c does not provide a full snprintf() implementation!).
1923 * It is recommended that production systems call uxTaskGetSystemState() directly
1924 * to get access to raw stats data, rather than indirectly through a call to
1925 * vTaskGetRunTimeStats().
1927 * @param pcWriteBuffer A buffer into which the execution times will be
1928 * written, in ASCII form. This buffer is assumed to be large enough to
1929 * contain the generated report. Approximately 40 bytes per task should
1932 * \defgroup vTaskGetRunTimeStats vTaskGetRunTimeStats
1933 * \ingroup TaskUtils
1935 void vTaskGetRunTimeStats( char * pcWriteBuffer ) PRIVILEGED_FUNCTION; /*lint !e971 Unqualified char types are allowed for strings and single characters only. */
1940 * configRUN_TIME_COUNTER_TYPE ulTaskGetIdleRunTimeCounter( void );
1941 * configRUN_TIME_COUNTER_TYPE ulTaskGetIdleRunTimePercent( void );
1944 * configGENERATE_RUN_TIME_STATS, configUSE_STATS_FORMATTING_FUNCTIONS and
1945 * INCLUDE_xTaskGetIdleTaskHandle must all be defined as 1 for these functions
1946 * to be available. The application must also then provide definitions for
1947 * portCONFIGURE_TIMER_FOR_RUN_TIME_STATS() and portGET_RUN_TIME_COUNTER_VALUE()
1948 * to configure a peripheral timer/counter and return the timers current count
1949 * value respectively. The counter should be at least 10 times the frequency of
1952 * Setting configGENERATE_RUN_TIME_STATS to 1 will result in a total
1953 * accumulated execution time being stored for each task. The resolution
1954 * of the accumulated time value depends on the frequency of the timer
1955 * configured by the portCONFIGURE_TIMER_FOR_RUN_TIME_STATS() macro.
1956 * While uxTaskGetSystemState() and vTaskGetRunTimeStats() writes the total
1957 * execution time of each task into a buffer, ulTaskGetIdleRunTimeCounter()
1958 * returns the total execution time of just the idle task and
1959 * ulTaskGetIdleRunTimePercent() returns the percentage of the CPU time used by
1960 * just the idle task.
1962 * Note the amount of idle time is only a good measure of the slack time in a
1963 * system if there are no other tasks executing at the idle priority, tickless
1964 * idle is not used, and configIDLE_SHOULD_YIELD is set to 0.
1966 * @return The total run time of the idle task or the percentage of the total
1967 * run time consumed by the idle task. This is the amount of time the
1968 * idle task has actually been executing. The unit of time is dependent on the
1969 * frequency configured using the portCONFIGURE_TIMER_FOR_RUN_TIME_STATS() and
1970 * portGET_RUN_TIME_COUNTER_VALUE() macros.
1972 * \defgroup ulTaskGetIdleRunTimeCounter ulTaskGetIdleRunTimeCounter
1973 * \ingroup TaskUtils
1975 configRUN_TIME_COUNTER_TYPE ulTaskGetIdleRunTimeCounter( void ) PRIVILEGED_FUNCTION;
1976 configRUN_TIME_COUNTER_TYPE ulTaskGetIdleRunTimePercent( void ) PRIVILEGED_FUNCTION;
1981 * BaseType_t xTaskNotifyIndexed( TaskHandle_t xTaskToNotify, UBaseType_t uxIndexToNotify, uint32_t ulValue, eNotifyAction eAction );
1982 * BaseType_t xTaskNotify( TaskHandle_t xTaskToNotify, uint32_t ulValue, eNotifyAction eAction );
1985 * See https://www.FreeRTOS.org/RTOS-task-notifications.html for details.
1987 * configUSE_TASK_NOTIFICATIONS must be undefined or defined as 1 for these
1988 * functions to be available.
1990 * Sends a direct to task notification to a task, with an optional value and
1993 * Each task has a private array of "notification values" (or 'notifications'),
1994 * each of which is a 32-bit unsigned integer (uint32_t). The constant
1995 * configTASK_NOTIFICATION_ARRAY_ENTRIES sets the number of indexes in the
1996 * array, and (for backward compatibility) defaults to 1 if left undefined.
1997 * Prior to FreeRTOS V10.4.0 there was only one notification value per task.
1999 * Events can be sent to a task using an intermediary object. Examples of such
2000 * objects are queues, semaphores, mutexes and event groups. Task notifications
2001 * are a method of sending an event directly to a task without the need for such
2002 * an intermediary object.
2004 * A notification sent to a task can optionally perform an action, such as
2005 * update, overwrite or increment one of the task's notification values. In
2006 * that way task notifications can be used to send data to a task, or be used as
2007 * light weight and fast binary or counting semaphores.
2009 * A task can use xTaskNotifyWaitIndexed() or ulTaskNotifyTakeIndexed() to
2010 * [optionally] block to wait for a notification to be pending. The task does
2011 * not consume any CPU time while it is in the Blocked state.
2013 * A notification sent to a task will remain pending until it is cleared by the
2014 * task calling xTaskNotifyWaitIndexed() or ulTaskNotifyTakeIndexed() (or their
2015 * un-indexed equivalents). If the task was already in the Blocked state to
2016 * wait for a notification when the notification arrives then the task will
2017 * automatically be removed from the Blocked state (unblocked) and the
2018 * notification cleared.
2020 * **NOTE** Each notification within the array operates independently - a task
2021 * can only block on one notification within the array at a time and will not be
2022 * unblocked by a notification sent to any other array index.
2024 * Backward compatibility information:
2025 * Prior to FreeRTOS V10.4.0 each task had a single "notification value", and
2026 * all task notification API functions operated on that value. Replacing the
2027 * single notification value with an array of notification values necessitated a
2028 * new set of API functions that could address specific notifications within the
2029 * array. xTaskNotify() is the original API function, and remains backward
2030 * compatible by always operating on the notification value at index 0 in the
2031 * array. Calling xTaskNotify() is equivalent to calling xTaskNotifyIndexed()
2032 * with the uxIndexToNotify parameter set to 0.
2034 * @param xTaskToNotify The handle of the task being notified. The handle to a
2035 * task can be returned from the xTaskCreate() API function used to create the
2036 * task, and the handle of the currently running task can be obtained by calling
2037 * xTaskGetCurrentTaskHandle().
2039 * @param uxIndexToNotify The index within the target task's array of
2040 * notification values to which the notification is to be sent. uxIndexToNotify
2041 * must be less than configTASK_NOTIFICATION_ARRAY_ENTRIES. xTaskNotify() does
2042 * not have this parameter and always sends notifications to index 0.
2044 * @param ulValue Data that can be sent with the notification. How the data is
2045 * used depends on the value of the eAction parameter.
2047 * @param eAction Specifies how the notification updates the task's notification
2048 * value, if at all. Valid values for eAction are as follows:
2051 * The target notification value is bitwise ORed with ulValue.
2052 * xTaskNotifyIndexed() always returns pdPASS in this case.
2055 * The target notification value is incremented. ulValue is not used and
2056 * xTaskNotifyIndexed() always returns pdPASS in this case.
2058 * eSetValueWithOverwrite -
2059 * The target notification value is set to the value of ulValue, even if the
2060 * task being notified had not yet processed the previous notification at the
2061 * same array index (the task already had a notification pending at that index).
2062 * xTaskNotifyIndexed() always returns pdPASS in this case.
2064 * eSetValueWithoutOverwrite -
2065 * If the task being notified did not already have a notification pending at the
2066 * same array index then the target notification value is set to ulValue and
2067 * xTaskNotifyIndexed() will return pdPASS. If the task being notified already
2068 * had a notification pending at the same array index then no action is
2069 * performed and pdFAIL is returned.
2072 * The task receives a notification at the specified array index without the
2073 * notification value at that index being updated. ulValue is not used and
2074 * xTaskNotifyIndexed() always returns pdPASS in this case.
2076 * pulPreviousNotificationValue -
2077 * Can be used to pass out the subject task's notification value before any
2078 * bits are modified by the notify function.
2080 * @return Dependent on the value of eAction. See the description of the
2081 * eAction parameter.
2083 * \defgroup xTaskNotifyIndexed xTaskNotifyIndexed
2084 * \ingroup TaskNotifications
2086 BaseType_t xTaskGenericNotify( TaskHandle_t xTaskToNotify,
2087 UBaseType_t uxIndexToNotify,
2089 eNotifyAction eAction,
2090 uint32_t * pulPreviousNotificationValue ) PRIVILEGED_FUNCTION;
2091 #define xTaskNotify( xTaskToNotify, ulValue, eAction ) \
2092 xTaskGenericNotify( ( xTaskToNotify ), ( tskDEFAULT_INDEX_TO_NOTIFY ), ( ulValue ), ( eAction ), NULL )
2093 #define xTaskNotifyIndexed( xTaskToNotify, uxIndexToNotify, ulValue, eAction ) \
2094 xTaskGenericNotify( ( xTaskToNotify ), ( uxIndexToNotify ), ( ulValue ), ( eAction ), NULL )
2099 * BaseType_t xTaskNotifyAndQueryIndexed( TaskHandle_t xTaskToNotify, UBaseType_t uxIndexToNotify, uint32_t ulValue, eNotifyAction eAction, uint32_t *pulPreviousNotifyValue );
2100 * BaseType_t xTaskNotifyAndQuery( TaskHandle_t xTaskToNotify, uint32_t ulValue, eNotifyAction eAction, uint32_t *pulPreviousNotifyValue );
2103 * See https://www.FreeRTOS.org/RTOS-task-notifications.html for details.
2105 * xTaskNotifyAndQueryIndexed() performs the same operation as
2106 * xTaskNotifyIndexed() with the addition that it also returns the subject
2107 * task's prior notification value (the notification value at the time the
2108 * function is called rather than when the function returns) in the additional
2109 * pulPreviousNotifyValue parameter.
2111 * xTaskNotifyAndQuery() performs the same operation as xTaskNotify() with the
2112 * addition that it also returns the subject task's prior notification value
2113 * (the notification value as it was at the time the function is called, rather
2114 * than when the function returns) in the additional pulPreviousNotifyValue
2117 * \defgroup xTaskNotifyAndQueryIndexed xTaskNotifyAndQueryIndexed
2118 * \ingroup TaskNotifications
2120 #define xTaskNotifyAndQuery( xTaskToNotify, ulValue, eAction, pulPreviousNotifyValue ) \
2121 xTaskGenericNotify( ( xTaskToNotify ), ( tskDEFAULT_INDEX_TO_NOTIFY ), ( ulValue ), ( eAction ), ( pulPreviousNotifyValue ) )
2122 #define xTaskNotifyAndQueryIndexed( xTaskToNotify, uxIndexToNotify, ulValue, eAction, pulPreviousNotifyValue ) \
2123 xTaskGenericNotify( ( xTaskToNotify ), ( uxIndexToNotify ), ( ulValue ), ( eAction ), ( pulPreviousNotifyValue ) )
2128 * BaseType_t xTaskNotifyIndexedFromISR( TaskHandle_t xTaskToNotify, UBaseType_t uxIndexToNotify, uint32_t ulValue, eNotifyAction eAction, BaseType_t *pxHigherPriorityTaskWoken );
2129 * BaseType_t xTaskNotifyFromISR( TaskHandle_t xTaskToNotify, uint32_t ulValue, eNotifyAction eAction, BaseType_t *pxHigherPriorityTaskWoken );
2132 * See https://www.FreeRTOS.org/RTOS-task-notifications.html for details.
2134 * configUSE_TASK_NOTIFICATIONS must be undefined or defined as 1 for these
2135 * functions to be available.
2137 * A version of xTaskNotifyIndexed() that can be used from an interrupt service
2140 * Each task has a private array of "notification values" (or 'notifications'),
2141 * each of which is a 32-bit unsigned integer (uint32_t). The constant
2142 * configTASK_NOTIFICATION_ARRAY_ENTRIES sets the number of indexes in the
2143 * array, and (for backward compatibility) defaults to 1 if left undefined.
2144 * Prior to FreeRTOS V10.4.0 there was only one notification value per task.
2146 * Events can be sent to a task using an intermediary object. Examples of such
2147 * objects are queues, semaphores, mutexes and event groups. Task notifications
2148 * are a method of sending an event directly to a task without the need for such
2149 * an intermediary object.
2151 * A notification sent to a task can optionally perform an action, such as
2152 * update, overwrite or increment one of the task's notification values. In
2153 * that way task notifications can be used to send data to a task, or be used as
2154 * light weight and fast binary or counting semaphores.
2156 * A task can use xTaskNotifyWaitIndexed() to [optionally] block to wait for a
2157 * notification to be pending, or ulTaskNotifyTakeIndexed() to [optionally] block
2158 * to wait for a notification value to have a non-zero value. The task does
2159 * not consume any CPU time while it is in the Blocked state.
2161 * A notification sent to a task will remain pending until it is cleared by the
2162 * task calling xTaskNotifyWaitIndexed() or ulTaskNotifyTakeIndexed() (or their
2163 * un-indexed equivalents). If the task was already in the Blocked state to
2164 * wait for a notification when the notification arrives then the task will
2165 * automatically be removed from the Blocked state (unblocked) and the
2166 * notification cleared.
2168 * **NOTE** Each notification within the array operates independently - a task
2169 * can only block on one notification within the array at a time and will not be
2170 * unblocked by a notification sent to any other array index.
2172 * Backward compatibility information:
2173 * Prior to FreeRTOS V10.4.0 each task had a single "notification value", and
2174 * all task notification API functions operated on that value. Replacing the
2175 * single notification value with an array of notification values necessitated a
2176 * new set of API functions that could address specific notifications within the
2177 * array. xTaskNotifyFromISR() is the original API function, and remains
2178 * backward compatible by always operating on the notification value at index 0
2179 * within the array. Calling xTaskNotifyFromISR() is equivalent to calling
2180 * xTaskNotifyIndexedFromISR() with the uxIndexToNotify parameter set to 0.
2182 * @param uxIndexToNotify The index within the target task's array of
2183 * notification values to which the notification is to be sent. uxIndexToNotify
2184 * must be less than configTASK_NOTIFICATION_ARRAY_ENTRIES. xTaskNotifyFromISR()
2185 * does not have this parameter and always sends notifications to index 0.
2187 * @param xTaskToNotify The handle of the task being notified. The handle to a
2188 * task can be returned from the xTaskCreate() API function used to create the
2189 * task, and the handle of the currently running task can be obtained by calling
2190 * xTaskGetCurrentTaskHandle().
2192 * @param ulValue Data that can be sent with the notification. How the data is
2193 * used depends on the value of the eAction parameter.
2195 * @param eAction Specifies how the notification updates the task's notification
2196 * value, if at all. Valid values for eAction are as follows:
2199 * The task's notification value is bitwise ORed with ulValue. xTaskNotify()
2200 * always returns pdPASS in this case.
2203 * The task's notification value is incremented. ulValue is not used and
2204 * xTaskNotify() always returns pdPASS in this case.
2206 * eSetValueWithOverwrite -
2207 * The task's notification value is set to the value of ulValue, even if the
2208 * task being notified had not yet processed the previous notification (the
2209 * task already had a notification pending). xTaskNotify() always returns
2210 * pdPASS in this case.
2212 * eSetValueWithoutOverwrite -
2213 * If the task being notified did not already have a notification pending then
2214 * the task's notification value is set to ulValue and xTaskNotify() will
2215 * return pdPASS. If the task being notified already had a notification
2216 * pending then no action is performed and pdFAIL is returned.
2219 * The task receives a notification without its notification value being
2220 * updated. ulValue is not used and xTaskNotify() always returns pdPASS in
2223 * @param pxHigherPriorityTaskWoken xTaskNotifyFromISR() will set
2224 * *pxHigherPriorityTaskWoken to pdTRUE if sending the notification caused the
2225 * task to which the notification was sent to leave the Blocked state, and the
2226 * unblocked task has a priority higher than the currently running task. If
2227 * xTaskNotifyFromISR() sets this value to pdTRUE then a context switch should
2228 * be requested before the interrupt is exited. How a context switch is
2229 * requested from an ISR is dependent on the port - see the documentation page
2230 * for the port in use.
2232 * @return Dependent on the value of eAction. See the description of the
2233 * eAction parameter.
2235 * \defgroup xTaskNotifyIndexedFromISR xTaskNotifyIndexedFromISR
2236 * \ingroup TaskNotifications
2238 BaseType_t xTaskGenericNotifyFromISR( TaskHandle_t xTaskToNotify,
2239 UBaseType_t uxIndexToNotify,
2241 eNotifyAction eAction,
2242 uint32_t * pulPreviousNotificationValue,
2243 BaseType_t * pxHigherPriorityTaskWoken ) PRIVILEGED_FUNCTION;
2244 #define xTaskNotifyFromISR( xTaskToNotify, ulValue, eAction, pxHigherPriorityTaskWoken ) \
2245 xTaskGenericNotifyFromISR( ( xTaskToNotify ), ( tskDEFAULT_INDEX_TO_NOTIFY ), ( ulValue ), ( eAction ), NULL, ( pxHigherPriorityTaskWoken ) )
2246 #define xTaskNotifyIndexedFromISR( xTaskToNotify, uxIndexToNotify, ulValue, eAction, pxHigherPriorityTaskWoken ) \
2247 xTaskGenericNotifyFromISR( ( xTaskToNotify ), ( uxIndexToNotify ), ( ulValue ), ( eAction ), NULL, ( pxHigherPriorityTaskWoken ) )
2252 * BaseType_t xTaskNotifyAndQueryIndexedFromISR( TaskHandle_t xTaskToNotify, UBaseType_t uxIndexToNotify, uint32_t ulValue, eNotifyAction eAction, uint32_t *pulPreviousNotificationValue, BaseType_t *pxHigherPriorityTaskWoken );
2253 * BaseType_t xTaskNotifyAndQueryFromISR( TaskHandle_t xTaskToNotify, uint32_t ulValue, eNotifyAction eAction, uint32_t *pulPreviousNotificationValue, BaseType_t *pxHigherPriorityTaskWoken );
2256 * See https://www.FreeRTOS.org/RTOS-task-notifications.html for details.
2258 * xTaskNotifyAndQueryIndexedFromISR() performs the same operation as
2259 * xTaskNotifyIndexedFromISR() with the addition that it also returns the
2260 * subject task's prior notification value (the notification value at the time
2261 * the function is called rather than at the time the function returns) in the
2262 * additional pulPreviousNotifyValue parameter.
2264 * xTaskNotifyAndQueryFromISR() performs the same operation as
2265 * xTaskNotifyFromISR() with the addition that it also returns the subject
2266 * task's prior notification value (the notification value at the time the
2267 * function is called rather than at the time the function returns) in the
2268 * additional pulPreviousNotifyValue parameter.
2270 * \defgroup xTaskNotifyAndQueryIndexedFromISR xTaskNotifyAndQueryIndexedFromISR
2271 * \ingroup TaskNotifications
2273 #define xTaskNotifyAndQueryIndexedFromISR( xTaskToNotify, uxIndexToNotify, ulValue, eAction, pulPreviousNotificationValue, pxHigherPriorityTaskWoken ) \
2274 xTaskGenericNotifyFromISR( ( xTaskToNotify ), ( uxIndexToNotify ), ( ulValue ), ( eAction ), ( pulPreviousNotificationValue ), ( pxHigherPriorityTaskWoken ) )
2275 #define xTaskNotifyAndQueryFromISR( xTaskToNotify, ulValue, eAction, pulPreviousNotificationValue, pxHigherPriorityTaskWoken ) \
2276 xTaskGenericNotifyFromISR( ( xTaskToNotify ), ( tskDEFAULT_INDEX_TO_NOTIFY ), ( ulValue ), ( eAction ), ( pulPreviousNotificationValue ), ( pxHigherPriorityTaskWoken ) )
2281 * BaseType_t xTaskNotifyWaitIndexed( UBaseType_t uxIndexToWaitOn, uint32_t ulBitsToClearOnEntry, uint32_t ulBitsToClearOnExit, uint32_t *pulNotificationValue, TickType_t xTicksToWait );
2283 * BaseType_t xTaskNotifyWait( uint32_t ulBitsToClearOnEntry, uint32_t ulBitsToClearOnExit, uint32_t *pulNotificationValue, TickType_t xTicksToWait );
2286 * Waits for a direct to task notification to be pending at a given index within
2287 * an array of direct to task notifications.
2289 * See https://www.FreeRTOS.org/RTOS-task-notifications.html for details.
2291 * configUSE_TASK_NOTIFICATIONS must be undefined or defined as 1 for this
2292 * function to be available.
2294 * Each task has a private array of "notification values" (or 'notifications'),
2295 * each of which is a 32-bit unsigned integer (uint32_t). The constant
2296 * configTASK_NOTIFICATION_ARRAY_ENTRIES sets the number of indexes in the
2297 * array, and (for backward compatibility) defaults to 1 if left undefined.
2298 * Prior to FreeRTOS V10.4.0 there was only one notification value per task.
2300 * Events can be sent to a task using an intermediary object. Examples of such
2301 * objects are queues, semaphores, mutexes and event groups. Task notifications
2302 * are a method of sending an event directly to a task without the need for such
2303 * an intermediary object.
2305 * A notification sent to a task can optionally perform an action, such as
2306 * update, overwrite or increment one of the task's notification values. In
2307 * that way task notifications can be used to send data to a task, or be used as
2308 * light weight and fast binary or counting semaphores.
2310 * A notification sent to a task will remain pending until it is cleared by the
2311 * task calling xTaskNotifyWaitIndexed() or ulTaskNotifyTakeIndexed() (or their
2312 * un-indexed equivalents). If the task was already in the Blocked state to
2313 * wait for a notification when the notification arrives then the task will
2314 * automatically be removed from the Blocked state (unblocked) and the
2315 * notification cleared.
2317 * A task can use xTaskNotifyWaitIndexed() to [optionally] block to wait for a
2318 * notification to be pending, or ulTaskNotifyTakeIndexed() to [optionally] block
2319 * to wait for a notification value to have a non-zero value. The task does
2320 * not consume any CPU time while it is in the Blocked state.
2322 * **NOTE** Each notification within the array operates independently - a task
2323 * can only block on one notification within the array at a time and will not be
2324 * unblocked by a notification sent to any other array index.
2326 * Backward compatibility information:
2327 * Prior to FreeRTOS V10.4.0 each task had a single "notification value", and
2328 * all task notification API functions operated on that value. Replacing the
2329 * single notification value with an array of notification values necessitated a
2330 * new set of API functions that could address specific notifications within the
2331 * array. xTaskNotifyWait() is the original API function, and remains backward
2332 * compatible by always operating on the notification value at index 0 in the
2333 * array. Calling xTaskNotifyWait() is equivalent to calling
2334 * xTaskNotifyWaitIndexed() with the uxIndexToWaitOn parameter set to 0.
2336 * @param uxIndexToWaitOn The index within the calling task's array of
2337 * notification values on which the calling task will wait for a notification to
2338 * be received. uxIndexToWaitOn must be less than
2339 * configTASK_NOTIFICATION_ARRAY_ENTRIES. xTaskNotifyWait() does
2340 * not have this parameter and always waits for notifications on index 0.
2342 * @param ulBitsToClearOnEntry Bits that are set in ulBitsToClearOnEntry value
2343 * will be cleared in the calling task's notification value before the task
2344 * checks to see if any notifications are pending, and optionally blocks if no
2345 * notifications are pending. Setting ulBitsToClearOnEntry to ULONG_MAX (if
2346 * limits.h is included) or 0xffffffffUL (if limits.h is not included) will have
2347 * the effect of resetting the task's notification value to 0. Setting
2348 * ulBitsToClearOnEntry to 0 will leave the task's notification value unchanged.
2350 * @param ulBitsToClearOnExit If a notification is pending or received before
2351 * the calling task exits the xTaskNotifyWait() function then the task's
2352 * notification value (see the xTaskNotify() API function) is passed out using
2353 * the pulNotificationValue parameter. Then any bits that are set in
2354 * ulBitsToClearOnExit will be cleared in the task's notification value (note
2355 * *pulNotificationValue is set before any bits are cleared). Setting
2356 * ulBitsToClearOnExit to ULONG_MAX (if limits.h is included) or 0xffffffffUL
2357 * (if limits.h is not included) will have the effect of resetting the task's
2358 * notification value to 0 before the function exits. Setting
2359 * ulBitsToClearOnExit to 0 will leave the task's notification value unchanged
2360 * when the function exits (in which case the value passed out in
2361 * pulNotificationValue will match the task's notification value).
2363 * @param pulNotificationValue Used to pass the task's notification value out
2364 * of the function. Note the value passed out will not be effected by the
2365 * clearing of any bits caused by ulBitsToClearOnExit being non-zero.
2367 * @param xTicksToWait The maximum amount of time that the task should wait in
2368 * the Blocked state for a notification to be received, should a notification
2369 * not already be pending when xTaskNotifyWait() was called. The task
2370 * will not consume any processing time while it is in the Blocked state. This
2371 * is specified in kernel ticks, the macro pdMS_TO_TICKS( value_in_ms ) can be
2372 * used to convert a time specified in milliseconds to a time specified in
2375 * @return If a notification was received (including notifications that were
2376 * already pending when xTaskNotifyWait was called) then pdPASS is
2377 * returned. Otherwise pdFAIL is returned.
2379 * \defgroup xTaskNotifyWaitIndexed xTaskNotifyWaitIndexed
2380 * \ingroup TaskNotifications
2382 BaseType_t xTaskGenericNotifyWait( UBaseType_t uxIndexToWaitOn,
2383 uint32_t ulBitsToClearOnEntry,
2384 uint32_t ulBitsToClearOnExit,
2385 uint32_t * pulNotificationValue,
2386 TickType_t xTicksToWait ) PRIVILEGED_FUNCTION;
2387 #define xTaskNotifyWait( ulBitsToClearOnEntry, ulBitsToClearOnExit, pulNotificationValue, xTicksToWait ) \
2388 xTaskGenericNotifyWait( tskDEFAULT_INDEX_TO_NOTIFY, ( ulBitsToClearOnEntry ), ( ulBitsToClearOnExit ), ( pulNotificationValue ), ( xTicksToWait ) )
2389 #define xTaskNotifyWaitIndexed( uxIndexToWaitOn, ulBitsToClearOnEntry, ulBitsToClearOnExit, pulNotificationValue, xTicksToWait ) \
2390 xTaskGenericNotifyWait( ( uxIndexToWaitOn ), ( ulBitsToClearOnEntry ), ( ulBitsToClearOnExit ), ( pulNotificationValue ), ( xTicksToWait ) )
2395 * BaseType_t xTaskNotifyGiveIndexed( TaskHandle_t xTaskToNotify, UBaseType_t uxIndexToNotify );
2396 * BaseType_t xTaskNotifyGive( TaskHandle_t xTaskToNotify );
2399 * Sends a direct to task notification to a particular index in the target
2400 * task's notification array in a manner similar to giving a counting semaphore.
2402 * See https://www.FreeRTOS.org/RTOS-task-notifications.html for more details.
2404 * configUSE_TASK_NOTIFICATIONS must be undefined or defined as 1 for these
2405 * macros to be available.
2407 * Each task has a private array of "notification values" (or 'notifications'),
2408 * each of which is a 32-bit unsigned integer (uint32_t). The constant
2409 * configTASK_NOTIFICATION_ARRAY_ENTRIES sets the number of indexes in the
2410 * array, and (for backward compatibility) defaults to 1 if left undefined.
2411 * Prior to FreeRTOS V10.4.0 there was only one notification value per task.
2413 * Events can be sent to a task using an intermediary object. Examples of such
2414 * objects are queues, semaphores, mutexes and event groups. Task notifications
2415 * are a method of sending an event directly to a task without the need for such
2416 * an intermediary object.
2418 * A notification sent to a task can optionally perform an action, such as
2419 * update, overwrite or increment one of the task's notification values. In
2420 * that way task notifications can be used to send data to a task, or be used as
2421 * light weight and fast binary or counting semaphores.
2423 * xTaskNotifyGiveIndexed() is a helper macro intended for use when task
2424 * notifications are used as light weight and faster binary or counting
2425 * semaphore equivalents. Actual FreeRTOS semaphores are given using the
2426 * xSemaphoreGive() API function, the equivalent action that instead uses a task
2427 * notification is xTaskNotifyGiveIndexed().
2429 * When task notifications are being used as a binary or counting semaphore
2430 * equivalent then the task being notified should wait for the notification
2431 * using the ulTaskNotifyTakeIndexed() API function rather than the
2432 * xTaskNotifyWaitIndexed() API function.
2434 * **NOTE** Each notification within the array operates independently - a task
2435 * can only block on one notification within the array at a time and will not be
2436 * unblocked by a notification sent to any other array index.
2438 * Backward compatibility information:
2439 * Prior to FreeRTOS V10.4.0 each task had a single "notification value", and
2440 * all task notification API functions operated on that value. Replacing the
2441 * single notification value with an array of notification values necessitated a
2442 * new set of API functions that could address specific notifications within the
2443 * array. xTaskNotifyGive() is the original API function, and remains backward
2444 * compatible by always operating on the notification value at index 0 in the
2445 * array. Calling xTaskNotifyGive() is equivalent to calling
2446 * xTaskNotifyGiveIndexed() with the uxIndexToNotify parameter set to 0.
2448 * @param xTaskToNotify The handle of the task being notified. The handle to a
2449 * task can be returned from the xTaskCreate() API function used to create the
2450 * task, and the handle of the currently running task can be obtained by calling
2451 * xTaskGetCurrentTaskHandle().
2453 * @param uxIndexToNotify The index within the target task's array of
2454 * notification values to which the notification is to be sent. uxIndexToNotify
2455 * must be less than configTASK_NOTIFICATION_ARRAY_ENTRIES. xTaskNotifyGive()
2456 * does not have this parameter and always sends notifications to index 0.
2458 * @return xTaskNotifyGive() is a macro that calls xTaskNotify() with the
2459 * eAction parameter set to eIncrement - so pdPASS is always returned.
2461 * \defgroup xTaskNotifyGiveIndexed xTaskNotifyGiveIndexed
2462 * \ingroup TaskNotifications
2464 #define xTaskNotifyGive( xTaskToNotify ) \
2465 xTaskGenericNotify( ( xTaskToNotify ), ( tskDEFAULT_INDEX_TO_NOTIFY ), ( 0 ), eIncrement, NULL )
2466 #define xTaskNotifyGiveIndexed( xTaskToNotify, uxIndexToNotify ) \
2467 xTaskGenericNotify( ( xTaskToNotify ), ( uxIndexToNotify ), ( 0 ), eIncrement, NULL )
2472 * void vTaskNotifyGiveIndexedFromISR( TaskHandle_t xTaskHandle, UBaseType_t uxIndexToNotify, BaseType_t *pxHigherPriorityTaskWoken );
2473 * void vTaskNotifyGiveFromISR( TaskHandle_t xTaskHandle, BaseType_t *pxHigherPriorityTaskWoken );
2476 * A version of xTaskNotifyGiveIndexed() that can be called from an interrupt
2477 * service routine (ISR).
2479 * See https://www.FreeRTOS.org/RTOS-task-notifications.html for more details.
2481 * configUSE_TASK_NOTIFICATIONS must be undefined or defined as 1 for this macro
2484 * Each task has a private array of "notification values" (or 'notifications'),
2485 * each of which is a 32-bit unsigned integer (uint32_t). The constant
2486 * configTASK_NOTIFICATION_ARRAY_ENTRIES sets the number of indexes in the
2487 * array, and (for backward compatibility) defaults to 1 if left undefined.
2488 * Prior to FreeRTOS V10.4.0 there was only one notification value per task.
2490 * Events can be sent to a task using an intermediary object. Examples of such
2491 * objects are queues, semaphores, mutexes and event groups. Task notifications
2492 * are a method of sending an event directly to a task without the need for such
2493 * an intermediary object.
2495 * A notification sent to a task can optionally perform an action, such as
2496 * update, overwrite or increment one of the task's notification values. In
2497 * that way task notifications can be used to send data to a task, or be used as
2498 * light weight and fast binary or counting semaphores.
2500 * vTaskNotifyGiveIndexedFromISR() is intended for use when task notifications
2501 * are used as light weight and faster binary or counting semaphore equivalents.
2502 * Actual FreeRTOS semaphores are given from an ISR using the
2503 * xSemaphoreGiveFromISR() API function, the equivalent action that instead uses
2504 * a task notification is vTaskNotifyGiveIndexedFromISR().
2506 * When task notifications are being used as a binary or counting semaphore
2507 * equivalent then the task being notified should wait for the notification
2508 * using the ulTaskNotifyTakeIndexed() API function rather than the
2509 * xTaskNotifyWaitIndexed() API function.
2511 * **NOTE** Each notification within the array operates independently - a task
2512 * can only block on one notification within the array at a time and will not be
2513 * unblocked by a notification sent to any other array index.
2515 * Backward compatibility information:
2516 * Prior to FreeRTOS V10.4.0 each task had a single "notification value", and
2517 * all task notification API functions operated on that value. Replacing the
2518 * single notification value with an array of notification values necessitated a
2519 * new set of API functions that could address specific notifications within the
2520 * array. xTaskNotifyFromISR() is the original API function, and remains
2521 * backward compatible by always operating on the notification value at index 0
2522 * within the array. Calling xTaskNotifyGiveFromISR() is equivalent to calling
2523 * xTaskNotifyGiveIndexedFromISR() with the uxIndexToNotify parameter set to 0.
2525 * @param xTaskToNotify The handle of the task being notified. The handle to a
2526 * task can be returned from the xTaskCreate() API function used to create the
2527 * task, and the handle of the currently running task can be obtained by calling
2528 * xTaskGetCurrentTaskHandle().
2530 * @param uxIndexToNotify The index within the target task's array of
2531 * notification values to which the notification is to be sent. uxIndexToNotify
2532 * must be less than configTASK_NOTIFICATION_ARRAY_ENTRIES.
2533 * xTaskNotifyGiveFromISR() does not have this parameter and always sends
2534 * notifications to index 0.
2536 * @param pxHigherPriorityTaskWoken vTaskNotifyGiveFromISR() will set
2537 * *pxHigherPriorityTaskWoken to pdTRUE if sending the notification caused the
2538 * task to which the notification was sent to leave the Blocked state, and the
2539 * unblocked task has a priority higher than the currently running task. If
2540 * vTaskNotifyGiveFromISR() sets this value to pdTRUE then a context switch
2541 * should be requested before the interrupt is exited. How a context switch is
2542 * requested from an ISR is dependent on the port - see the documentation page
2543 * for the port in use.
2545 * \defgroup vTaskNotifyGiveIndexedFromISR vTaskNotifyGiveIndexedFromISR
2546 * \ingroup TaskNotifications
2548 void vTaskGenericNotifyGiveFromISR( TaskHandle_t xTaskToNotify,
2549 UBaseType_t uxIndexToNotify,
2550 BaseType_t * pxHigherPriorityTaskWoken ) PRIVILEGED_FUNCTION;
2551 #define vTaskNotifyGiveFromISR( xTaskToNotify, pxHigherPriorityTaskWoken ) \
2552 vTaskGenericNotifyGiveFromISR( ( xTaskToNotify ), ( tskDEFAULT_INDEX_TO_NOTIFY ), ( pxHigherPriorityTaskWoken ) )
2553 #define vTaskNotifyGiveIndexedFromISR( xTaskToNotify, uxIndexToNotify, pxHigherPriorityTaskWoken ) \
2554 vTaskGenericNotifyGiveFromISR( ( xTaskToNotify ), ( uxIndexToNotify ), ( pxHigherPriorityTaskWoken ) )
2559 * uint32_t ulTaskNotifyTakeIndexed( UBaseType_t uxIndexToWaitOn, BaseType_t xClearCountOnExit, TickType_t xTicksToWait );
2561 * uint32_t ulTaskNotifyTake( BaseType_t xClearCountOnExit, TickType_t xTicksToWait );
2564 * Waits for a direct to task notification on a particular index in the calling
2565 * task's notification array in a manner similar to taking a counting semaphore.
2567 * See https://www.FreeRTOS.org/RTOS-task-notifications.html for details.
2569 * configUSE_TASK_NOTIFICATIONS must be undefined or defined as 1 for this
2570 * function to be available.
2572 * Each task has a private array of "notification values" (or 'notifications'),
2573 * each of which is a 32-bit unsigned integer (uint32_t). The constant
2574 * configTASK_NOTIFICATION_ARRAY_ENTRIES sets the number of indexes in the
2575 * array, and (for backward compatibility) defaults to 1 if left undefined.
2576 * Prior to FreeRTOS V10.4.0 there was only one notification value per task.
2578 * Events can be sent to a task using an intermediary object. Examples of such
2579 * objects are queues, semaphores, mutexes and event groups. Task notifications
2580 * are a method of sending an event directly to a task without the need for such
2581 * an intermediary object.
2583 * A notification sent to a task can optionally perform an action, such as
2584 * update, overwrite or increment one of the task's notification values. In
2585 * that way task notifications can be used to send data to a task, or be used as
2586 * light weight and fast binary or counting semaphores.
2588 * ulTaskNotifyTakeIndexed() is intended for use when a task notification is
2589 * used as a faster and lighter weight binary or counting semaphore alternative.
2590 * Actual FreeRTOS semaphores are taken using the xSemaphoreTake() API function,
2591 * the equivalent action that instead uses a task notification is
2592 * ulTaskNotifyTakeIndexed().
2594 * When a task is using its notification value as a binary or counting semaphore
2595 * other tasks should send notifications to it using the xTaskNotifyGiveIndexed()
2596 * macro, or xTaskNotifyIndex() function with the eAction parameter set to
2599 * ulTaskNotifyTakeIndexed() can either clear the task's notification value at
2600 * the array index specified by the uxIndexToWaitOn parameter to zero on exit,
2601 * in which case the notification value acts like a binary semaphore, or
2602 * decrement the notification value on exit, in which case the notification
2603 * value acts like a counting semaphore.
2605 * A task can use ulTaskNotifyTakeIndexed() to [optionally] block to wait for
2606 * a notification. The task does not consume any CPU time while it is in the
2609 * Where as xTaskNotifyWaitIndexed() will return when a notification is pending,
2610 * ulTaskNotifyTakeIndexed() will return when the task's notification value is
2613 * **NOTE** Each notification within the array operates independently - a task
2614 * can only block on one notification within the array at a time and will not be
2615 * unblocked by a notification sent to any other array index.
2617 * Backward compatibility information:
2618 * Prior to FreeRTOS V10.4.0 each task had a single "notification value", and
2619 * all task notification API functions operated on that value. Replacing the
2620 * single notification value with an array of notification values necessitated a
2621 * new set of API functions that could address specific notifications within the
2622 * array. ulTaskNotifyTake() is the original API function, and remains backward
2623 * compatible by always operating on the notification value at index 0 in the
2624 * array. Calling ulTaskNotifyTake() is equivalent to calling
2625 * ulTaskNotifyTakeIndexed() with the uxIndexToWaitOn parameter set to 0.
2627 * @param uxIndexToWaitOn The index within the calling task's array of
2628 * notification values on which the calling task will wait for a notification to
2629 * be non-zero. uxIndexToWaitOn must be less than
2630 * configTASK_NOTIFICATION_ARRAY_ENTRIES. xTaskNotifyTake() does
2631 * not have this parameter and always waits for notifications on index 0.
2633 * @param xClearCountOnExit if xClearCountOnExit is pdFALSE then the task's
2634 * notification value is decremented when the function exits. In this way the
2635 * notification value acts like a counting semaphore. If xClearCountOnExit is
2636 * not pdFALSE then the task's notification value is cleared to zero when the
2637 * function exits. In this way the notification value acts like a binary
2640 * @param xTicksToWait The maximum amount of time that the task should wait in
2641 * the Blocked state for the task's notification value to be greater than zero,
2642 * should the count not already be greater than zero when
2643 * ulTaskNotifyTake() was called. The task will not consume any processing
2644 * time while it is in the Blocked state. This is specified in kernel ticks,
2645 * the macro pdMS_TO_TICKS( value_in_ms ) can be used to convert a time
2646 * specified in milliseconds to a time specified in ticks.
2648 * @return The task's notification count before it is either cleared to zero or
2649 * decremented (see the xClearCountOnExit parameter).
2651 * \defgroup ulTaskNotifyTakeIndexed ulTaskNotifyTakeIndexed
2652 * \ingroup TaskNotifications
2654 uint32_t ulTaskGenericNotifyTake( UBaseType_t uxIndexToWaitOn,
2655 BaseType_t xClearCountOnExit,
2656 TickType_t xTicksToWait ) PRIVILEGED_FUNCTION;
2657 #define ulTaskNotifyTake( xClearCountOnExit, xTicksToWait ) \
2658 ulTaskGenericNotifyTake( ( tskDEFAULT_INDEX_TO_NOTIFY ), ( xClearCountOnExit ), ( xTicksToWait ) )
2659 #define ulTaskNotifyTakeIndexed( uxIndexToWaitOn, xClearCountOnExit, xTicksToWait ) \
2660 ulTaskGenericNotifyTake( ( uxIndexToWaitOn ), ( xClearCountOnExit ), ( xTicksToWait ) )
2665 * BaseType_t xTaskNotifyStateClearIndexed( TaskHandle_t xTask, UBaseType_t uxIndexToCLear );
2667 * BaseType_t xTaskNotifyStateClear( TaskHandle_t xTask );
2670 * See https://www.FreeRTOS.org/RTOS-task-notifications.html for details.
2672 * configUSE_TASK_NOTIFICATIONS must be undefined or defined as 1 for these
2673 * functions to be available.
2675 * Each task has a private array of "notification values" (or 'notifications'),
2676 * each of which is a 32-bit unsigned integer (uint32_t). The constant
2677 * configTASK_NOTIFICATION_ARRAY_ENTRIES sets the number of indexes in the
2678 * array, and (for backward compatibility) defaults to 1 if left undefined.
2679 * Prior to FreeRTOS V10.4.0 there was only one notification value per task.
2681 * If a notification is sent to an index within the array of notifications then
2682 * the notification at that index is said to be 'pending' until it is read or
2683 * explicitly cleared by the receiving task. xTaskNotifyStateClearIndexed()
2684 * is the function that clears a pending notification without reading the
2685 * notification value. The notification value at the same array index is not
2686 * altered. Set xTask to NULL to clear the notification state of the calling
2689 * Backward compatibility information:
2690 * Prior to FreeRTOS V10.4.0 each task had a single "notification value", and
2691 * all task notification API functions operated on that value. Replacing the
2692 * single notification value with an array of notification values necessitated a
2693 * new set of API functions that could address specific notifications within the
2694 * array. xTaskNotifyStateClear() is the original API function, and remains
2695 * backward compatible by always operating on the notification value at index 0
2696 * within the array. Calling xTaskNotifyStateClear() is equivalent to calling
2697 * xTaskNotifyStateClearIndexed() with the uxIndexToNotify parameter set to 0.
2699 * @param xTask The handle of the RTOS task that will have a notification state
2700 * cleared. Set xTask to NULL to clear a notification state in the calling
2701 * task. To obtain a task's handle create the task using xTaskCreate() and
2702 * make use of the pxCreatedTask parameter, or create the task using
2703 * xTaskCreateStatic() and store the returned value, or use the task's name in
2704 * a call to xTaskGetHandle().
2706 * @param uxIndexToClear The index within the target task's array of
2707 * notification values to act upon. For example, setting uxIndexToClear to 1
2708 * will clear the state of the notification at index 1 within the array.
2709 * uxIndexToClear must be less than configTASK_NOTIFICATION_ARRAY_ENTRIES.
2710 * ulTaskNotifyStateClear() does not have this parameter and always acts on the
2711 * notification at index 0.
2713 * @return pdTRUE if the task's notification state was set to
2714 * eNotWaitingNotification, otherwise pdFALSE.
2716 * \defgroup xTaskNotifyStateClearIndexed xTaskNotifyStateClearIndexed
2717 * \ingroup TaskNotifications
2719 BaseType_t xTaskGenericNotifyStateClear( TaskHandle_t xTask,
2720 UBaseType_t uxIndexToClear ) PRIVILEGED_FUNCTION;
2721 #define xTaskNotifyStateClear( xTask ) \
2722 xTaskGenericNotifyStateClear( ( xTask ), ( tskDEFAULT_INDEX_TO_NOTIFY ) )
2723 #define xTaskNotifyStateClearIndexed( xTask, uxIndexToClear ) \
2724 xTaskGenericNotifyStateClear( ( xTask ), ( uxIndexToClear ) )
2729 * uint32_t ulTaskNotifyValueClearIndexed( TaskHandle_t xTask, UBaseType_t uxIndexToClear, uint32_t ulBitsToClear );
2731 * uint32_t ulTaskNotifyValueClear( TaskHandle_t xTask, uint32_t ulBitsToClear );
2734 * See https://www.FreeRTOS.org/RTOS-task-notifications.html for details.
2736 * configUSE_TASK_NOTIFICATIONS must be undefined or defined as 1 for these
2737 * functions to be available.
2739 * Each task has a private array of "notification values" (or 'notifications'),
2740 * each of which is a 32-bit unsigned integer (uint32_t). The constant
2741 * configTASK_NOTIFICATION_ARRAY_ENTRIES sets the number of indexes in the
2742 * array, and (for backward compatibility) defaults to 1 if left undefined.
2743 * Prior to FreeRTOS V10.4.0 there was only one notification value per task.
2745 * ulTaskNotifyValueClearIndexed() clears the bits specified by the
2746 * ulBitsToClear bit mask in the notification value at array index uxIndexToClear
2747 * of the task referenced by xTask.
2749 * Backward compatibility information:
2750 * Prior to FreeRTOS V10.4.0 each task had a single "notification value", and
2751 * all task notification API functions operated on that value. Replacing the
2752 * single notification value with an array of notification values necessitated a
2753 * new set of API functions that could address specific notifications within the
2754 * array. ulTaskNotifyValueClear() is the original API function, and remains
2755 * backward compatible by always operating on the notification value at index 0
2756 * within the array. Calling ulTaskNotifyValueClear() is equivalent to calling
2757 * ulTaskNotifyValueClearIndexed() with the uxIndexToClear parameter set to 0.
2759 * @param xTask The handle of the RTOS task that will have bits in one of its
2760 * notification values cleared. Set xTask to NULL to clear bits in a
2761 * notification value of the calling task. To obtain a task's handle create the
2762 * task using xTaskCreate() and make use of the pxCreatedTask parameter, or
2763 * create the task using xTaskCreateStatic() and store the returned value, or
2764 * use the task's name in a call to xTaskGetHandle().
2766 * @param uxIndexToClear The index within the target task's array of
2767 * notification values in which to clear the bits. uxIndexToClear
2768 * must be less than configTASK_NOTIFICATION_ARRAY_ENTRIES.
2769 * ulTaskNotifyValueClear() does not have this parameter and always clears bits
2770 * in the notification value at index 0.
2772 * @param ulBitsToClear Bit mask of the bits to clear in the notification value of
2773 * xTask. Set a bit to 1 to clear the corresponding bits in the task's notification
2774 * value. Set ulBitsToClear to 0xffffffff (UINT_MAX on 32-bit architectures) to clear
2775 * the notification value to 0. Set ulBitsToClear to 0 to query the task's
2776 * notification value without clearing any bits.
2779 * @return The value of the target task's notification value before the bits
2780 * specified by ulBitsToClear were cleared.
2781 * \defgroup ulTaskNotifyValueClear ulTaskNotifyValueClear
2782 * \ingroup TaskNotifications
2784 uint32_t ulTaskGenericNotifyValueClear( TaskHandle_t xTask,
2785 UBaseType_t uxIndexToClear,
2786 uint32_t ulBitsToClear ) PRIVILEGED_FUNCTION;
2787 #define ulTaskNotifyValueClear( xTask, ulBitsToClear ) \
2788 ulTaskGenericNotifyValueClear( ( xTask ), ( tskDEFAULT_INDEX_TO_NOTIFY ), ( ulBitsToClear ) )
2789 #define ulTaskNotifyValueClearIndexed( xTask, uxIndexToClear, ulBitsToClear ) \
2790 ulTaskGenericNotifyValueClear( ( xTask ), ( uxIndexToClear ), ( ulBitsToClear ) )
2795 * void vTaskSetTimeOutState( TimeOut_t * const pxTimeOut );
2798 * Capture the current time for future use with xTaskCheckForTimeOut().
2800 * @param pxTimeOut Pointer to a timeout object into which the current time
2801 * is to be captured. The captured time includes the tick count and the number
2802 * of times the tick count has overflowed since the system first booted.
2803 * \defgroup vTaskSetTimeOutState vTaskSetTimeOutState
2806 void vTaskSetTimeOutState( TimeOut_t * const pxTimeOut ) PRIVILEGED_FUNCTION;
2811 * BaseType_t xTaskCheckForTimeOut( TimeOut_t * const pxTimeOut, TickType_t * const pxTicksToWait );
2814 * Determines if pxTicksToWait ticks has passed since a time was captured
2815 * using a call to vTaskSetTimeOutState(). The captured time includes the tick
2816 * count and the number of times the tick count has overflowed.
2818 * @param pxTimeOut The time status as captured previously using
2819 * vTaskSetTimeOutState. If the timeout has not yet occurred, it is updated
2820 * to reflect the current time status.
2821 * @param pxTicksToWait The number of ticks to check for timeout i.e. if
2822 * pxTicksToWait ticks have passed since pxTimeOut was last updated (either by
2823 * vTaskSetTimeOutState() or xTaskCheckForTimeOut()), the timeout has occurred.
2824 * If the timeout has not occurred, pxTicksToWait is updated to reflect the
2825 * number of remaining ticks.
2827 * @return If timeout has occurred, pdTRUE is returned. Otherwise pdFALSE is
2828 * returned and pxTicksToWait is updated to reflect the number of remaining
2831 * @see https://www.FreeRTOS.org/xTaskCheckForTimeOut.html
2835 * // Driver library function used to receive uxWantedBytes from an Rx buffer
2836 * // that is filled by a UART interrupt. If there are not enough bytes in the
2837 * // Rx buffer then the task enters the Blocked state until it is notified that
2838 * // more data has been placed into the buffer. If there is still not enough
2839 * // data then the task re-enters the Blocked state, and xTaskCheckForTimeOut()
2840 * // is used to re-calculate the Block time to ensure the total amount of time
2841 * // spent in the Blocked state does not exceed MAX_TIME_TO_WAIT. This
2842 * // continues until either the buffer contains at least uxWantedBytes bytes,
2843 * // or the total amount of time spent in the Blocked state reaches
2844 * // MAX_TIME_TO_WAIT - at which point the task reads however many bytes are
2845 * // available up to a maximum of uxWantedBytes.
2847 * size_t xUART_Receive( uint8_t *pucBuffer, size_t uxWantedBytes )
2849 * size_t uxReceived = 0;
2850 * TickType_t xTicksToWait = MAX_TIME_TO_WAIT;
2851 * TimeOut_t xTimeOut;
2853 * // Initialize xTimeOut. This records the time at which this function
2855 * vTaskSetTimeOutState( &xTimeOut );
2857 * // Loop until the buffer contains the wanted number of bytes, or a
2858 * // timeout occurs.
2859 * while( UART_bytes_in_rx_buffer( pxUARTInstance ) < uxWantedBytes )
2861 * // The buffer didn't contain enough data so this task is going to
2862 * // enter the Blocked state. Adjusting xTicksToWait to account for
2863 * // any time that has been spent in the Blocked state within this
2864 * // function so far to ensure the total amount of time spent in the
2865 * // Blocked state does not exceed MAX_TIME_TO_WAIT.
2866 * if( xTaskCheckForTimeOut( &xTimeOut, &xTicksToWait ) != pdFALSE )
2868 * //Timed out before the wanted number of bytes were available,
2873 * // Wait for a maximum of xTicksToWait ticks to be notified that the
2874 * // receive interrupt has placed more data into the buffer.
2875 * ulTaskNotifyTake( pdTRUE, xTicksToWait );
2878 * // Attempt to read uxWantedBytes from the receive buffer into pucBuffer.
2879 * // The actual number of bytes read (which might be less than
2880 * // uxWantedBytes) is returned.
2881 * uxReceived = UART_read_from_receive_buffer( pxUARTInstance,
2885 * return uxReceived;
2888 * \defgroup xTaskCheckForTimeOut xTaskCheckForTimeOut
2891 BaseType_t xTaskCheckForTimeOut( TimeOut_t * const pxTimeOut,
2892 TickType_t * const pxTicksToWait ) PRIVILEGED_FUNCTION;
2897 * BaseType_t xTaskCatchUpTicks( TickType_t xTicksToCatchUp );
2900 * This function corrects the tick count value after the application code has held
2901 * interrupts disabled for an extended period resulting in tick interrupts having
2904 * This function is similar to vTaskStepTick(), however, unlike
2905 * vTaskStepTick(), xTaskCatchUpTicks() may move the tick count forward past a
2906 * time at which a task should be removed from the blocked state. That means
2907 * tasks may have to be removed from the blocked state as the tick count is
2910 * @param xTicksToCatchUp The number of tick interrupts that have been missed due to
2911 * interrupts being disabled. Its value is not computed automatically, so must be
2912 * computed by the application writer.
2914 * @return pdTRUE if moving the tick count forward resulted in a task leaving the
2915 * blocked state and a context switch being performed. Otherwise pdFALSE.
2917 * \defgroup xTaskCatchUpTicks xTaskCatchUpTicks
2920 BaseType_t xTaskCatchUpTicks( TickType_t xTicksToCatchUp ) PRIVILEGED_FUNCTION;
2923 /*-----------------------------------------------------------
2924 * SCHEDULER INTERNALS AVAILABLE FOR PORTING PURPOSES
2925 *----------------------------------------------------------*/
2928 * THIS FUNCTION MUST NOT BE USED FROM APPLICATION CODE. IT IS ONLY
2929 * INTENDED FOR USE WHEN IMPLEMENTING A PORT OF THE SCHEDULER AND IS
2930 * AN INTERFACE WHICH IS FOR THE EXCLUSIVE USE OF THE SCHEDULER.
2932 * Called from the real time kernel tick (either preemptive or cooperative),
2933 * this increments the tick count and checks if any tasks that are blocked
2934 * for a finite period required removing from a blocked list and placing on
2935 * a ready list. If a non-zero value is returned then a context switch is
2936 * required because either:
2937 * + A task was removed from a blocked list because its timeout had expired,
2939 * + Time slicing is in use and there is a task of equal priority to the
2940 * currently running task.
2942 BaseType_t xTaskIncrementTick( void ) PRIVILEGED_FUNCTION;
2945 * THIS FUNCTION MUST NOT BE USED FROM APPLICATION CODE. IT IS AN
2946 * INTERFACE WHICH IS FOR THE EXCLUSIVE USE OF THE SCHEDULER.
2948 * THIS FUNCTION MUST BE CALLED WITH INTERRUPTS DISABLED.
2950 * Removes the calling task from the ready list and places it both
2951 * on the list of tasks waiting for a particular event, and the
2952 * list of delayed tasks. The task will be removed from both lists
2953 * and replaced on the ready list should either the event occur (and
2954 * there be no higher priority tasks waiting on the same event) or
2955 * the delay period expires.
2957 * The 'unordered' version replaces the event list item value with the
2958 * xItemValue value, and inserts the list item at the end of the list.
2960 * The 'ordered' version uses the existing event list item value (which is the
2961 * owning task's priority) to insert the list item into the event list in task
2964 * @param pxEventList The list containing tasks that are blocked waiting
2965 * for the event to occur.
2967 * @param xItemValue The item value to use for the event list item when the
2968 * event list is not ordered by task priority.
2970 * @param xTicksToWait The maximum amount of time that the task should wait
2971 * for the event to occur. This is specified in kernel ticks, the constant
2972 * portTICK_PERIOD_MS can be used to convert kernel ticks into a real time
2975 void vTaskPlaceOnEventList( List_t * const pxEventList,
2976 const TickType_t xTicksToWait ) PRIVILEGED_FUNCTION;
2977 void vTaskPlaceOnUnorderedEventList( List_t * pxEventList,
2978 const TickType_t xItemValue,
2979 const TickType_t xTicksToWait ) PRIVILEGED_FUNCTION;
2982 * THIS FUNCTION MUST NOT BE USED FROM APPLICATION CODE. IT IS AN
2983 * INTERFACE WHICH IS FOR THE EXCLUSIVE USE OF THE SCHEDULER.
2985 * THIS FUNCTION MUST BE CALLED WITH INTERRUPTS DISABLED.
2987 * This function performs nearly the same function as vTaskPlaceOnEventList().
2988 * The difference being that this function does not permit tasks to block
2989 * indefinitely, whereas vTaskPlaceOnEventList() does.
2992 void vTaskPlaceOnEventListRestricted( List_t * const pxEventList,
2993 TickType_t xTicksToWait,
2994 const BaseType_t xWaitIndefinitely ) PRIVILEGED_FUNCTION;
2997 * THIS FUNCTION MUST NOT BE USED FROM APPLICATION CODE. IT IS AN
2998 * INTERFACE WHICH IS FOR THE EXCLUSIVE USE OF THE SCHEDULER.
3000 * THIS FUNCTION MUST BE CALLED WITH INTERRUPTS DISABLED.
3002 * Removes a task from both the specified event list and the list of blocked
3003 * tasks, and places it on a ready queue.
3005 * xTaskRemoveFromEventList()/vTaskRemoveFromUnorderedEventList() will be called
3006 * if either an event occurs to unblock a task, or the block timeout period
3009 * xTaskRemoveFromEventList() is used when the event list is in task priority
3010 * order. It removes the list item from the head of the event list as that will
3011 * have the highest priority owning task of all the tasks on the event list.
3012 * vTaskRemoveFromUnorderedEventList() is used when the event list is not
3013 * ordered and the event list items hold something other than the owning tasks
3014 * priority. In this case the event list item value is updated to the value
3015 * passed in the xItemValue parameter.
3017 * @return pdTRUE if the task being removed has a higher priority than the task
3018 * making the call, otherwise pdFALSE.
3020 BaseType_t xTaskRemoveFromEventList( const List_t * const pxEventList ) PRIVILEGED_FUNCTION;
3021 void vTaskRemoveFromUnorderedEventList( ListItem_t * pxEventListItem,
3022 const TickType_t xItemValue ) PRIVILEGED_FUNCTION;
3025 * THIS FUNCTION MUST NOT BE USED FROM APPLICATION CODE. IT IS ONLY
3026 * INTENDED FOR USE WHEN IMPLEMENTING A PORT OF THE SCHEDULER AND IS
3027 * AN INTERFACE WHICH IS FOR THE EXCLUSIVE USE OF THE SCHEDULER.
3029 * Sets the pointer to the current TCB to the TCB of the highest priority task
3030 * that is ready to run.
3032 portDONT_DISCARD void vTaskSwitchContext( void ) PRIVILEGED_FUNCTION;
3035 * THESE FUNCTIONS MUST NOT BE USED FROM APPLICATION CODE. THEY ARE USED BY
3036 * THE EVENT BITS MODULE.
3038 TickType_t uxTaskResetEventItemValue( void ) PRIVILEGED_FUNCTION;
3041 * Return the handle of the calling task.
3043 TaskHandle_t xTaskGetCurrentTaskHandle( void ) PRIVILEGED_FUNCTION;
3046 * Shortcut used by the queue implementation to prevent unnecessary call to
3049 void vTaskMissedYield( void ) PRIVILEGED_FUNCTION;
3052 * Returns the scheduler state as taskSCHEDULER_RUNNING,
3053 * taskSCHEDULER_NOT_STARTED or taskSCHEDULER_SUSPENDED.
3055 BaseType_t xTaskGetSchedulerState( void ) PRIVILEGED_FUNCTION;
3058 * Raises the priority of the mutex holder to that of the calling task should
3059 * the mutex holder have a priority less than the calling task.
3061 BaseType_t xTaskPriorityInherit( TaskHandle_t const pxMutexHolder ) PRIVILEGED_FUNCTION;
3064 * Set the priority of a task back to its proper priority in the case that it
3065 * inherited a higher priority while it was holding a semaphore.
3067 BaseType_t xTaskPriorityDisinherit( TaskHandle_t const pxMutexHolder ) PRIVILEGED_FUNCTION;
3070 * If a higher priority task attempting to obtain a mutex caused a lower
3071 * priority task to inherit the higher priority task's priority - but the higher
3072 * priority task then timed out without obtaining the mutex, then the lower
3073 * priority task will disinherit the priority again - but only down as far as
3074 * the highest priority task that is still waiting for the mutex (if there were
3075 * more than one task waiting for the mutex).
3077 void vTaskPriorityDisinheritAfterTimeout( TaskHandle_t const pxMutexHolder,
3078 UBaseType_t uxHighestPriorityWaitingTask ) PRIVILEGED_FUNCTION;
3081 * Get the uxTaskNumber assigned to the task referenced by the xTask parameter.
3083 UBaseType_t uxTaskGetTaskNumber( TaskHandle_t xTask ) PRIVILEGED_FUNCTION;
3086 * Set the uxTaskNumber of the task referenced by the xTask parameter to
3089 void vTaskSetTaskNumber( TaskHandle_t xTask,
3090 const UBaseType_t uxHandle ) PRIVILEGED_FUNCTION;
3093 * Only available when configUSE_TICKLESS_IDLE is set to 1.
3094 * If tickless mode is being used, or a low power mode is implemented, then
3095 * the tick interrupt will not execute during idle periods. When this is the
3096 * case, the tick count value maintained by the scheduler needs to be kept up
3097 * to date with the actual execution time by being skipped forward by a time
3098 * equal to the idle period.
3100 void vTaskStepTick( TickType_t xTicksToJump ) PRIVILEGED_FUNCTION;
3103 * Only available when configUSE_TICKLESS_IDLE is set to 1.
3104 * Provided for use within portSUPPRESS_TICKS_AND_SLEEP() to allow the port
3105 * specific sleep function to determine if it is ok to proceed with the sleep,
3106 * and if it is ok to proceed, if it is ok to sleep indefinitely.
3108 * This function is necessary because portSUPPRESS_TICKS_AND_SLEEP() is only
3109 * called with the scheduler suspended, not from within a critical section. It
3110 * is therefore possible for an interrupt to request a context switch between
3111 * portSUPPRESS_TICKS_AND_SLEEP() and the low power mode actually being
3112 * entered. eTaskConfirmSleepModeStatus() should be called from a short
3113 * critical section between the timer being stopped and the sleep mode being
3114 * entered to ensure it is ok to proceed into the sleep mode.
3116 eSleepModeStatus eTaskConfirmSleepModeStatus( void ) PRIVILEGED_FUNCTION;
3119 * For internal use only. Increment the mutex held count when a mutex is
3120 * taken and return the handle of the task that has taken the mutex.
3122 TaskHandle_t pvTaskIncrementMutexHeldCount( void ) PRIVILEGED_FUNCTION;
3125 * For internal use only. Same as vTaskSetTimeOutState(), but without a critical
3128 void vTaskInternalSetTimeOutState( TimeOut_t * const pxTimeOut ) PRIVILEGED_FUNCTION;
3136 #endif /* INC_TASK_H */