/*
* FreeRTOS Kernel V10.4.4
* Copyright (C) 2021 Amazon.com, Inc. or its affiliates. All Rights Reserved.
*
* SPDX-License-Identifier: MIT
*
* Permission is hereby granted, free of charge, to any person obtaining a copy of
* this software and associated documentation files (the "Software"), to deal in
* the Software without restriction, including without limitation the rights to
* use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
* the Software, and to permit persons to whom the Software is furnished to do so,
* subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in all
* copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
* FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
* COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
* IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*
* https://www.FreeRTOS.org
* https://github.com/FreeRTOS
*
*/
#ifndef EVENT_GROUPS_H
#define EVENT_GROUPS_H
#ifndef INC_FREERTOS_H
#error "include FreeRTOS.h" must appear in source files before "include event_groups.h"
#endif
/* FreeRTOS includes. */
#include "timers.h"
/* *INDENT-OFF* */
#ifdef __cplusplus
extern "C" {
#endif
/* *INDENT-ON* */
/**
* An event group is a collection of bits to which an application can assign a
* meaning. For example, an application may create an event group to convey
* the status of various CAN bus related events in which bit 0 might mean "A CAN
* message has been received and is ready for processing", bit 1 might mean "The
* application has queued a message that is ready for sending onto the CAN
* network", and bit 2 might mean "It is time to send a SYNC message onto the
* CAN network" etc. A task can then test the bit values to see which events
* are active, and optionally enter the Blocked state to wait for a specified
* bit or a group of specified bits to be active. To continue the CAN bus
* example, a CAN controlling task can enter the Blocked state (and therefore
* not consume any processing time) until either bit 0, bit 1 or bit 2 are
* active, at which time the bit that was actually active would inform the task
* which action it had to take (process a received message, send a message, or
* send a SYNC).
*
* The event groups implementation contains intelligence to avoid race
* conditions that would otherwise occur were an application to use a simple
* variable for the same purpose. This is particularly important with respect
* to when a bit within an event group is to be cleared, and when bits have to
* be set and then tested atomically - as is the case where event groups are
* used to create a synchronisation point between multiple tasks (a
* 'rendezvous').
*
* \defgroup EventGroup
*/
/**
* event_groups.h
*
* Type by which event groups are referenced. For example, a call to
* xEventGroupCreate() returns an EventGroupHandle_t variable that can then
* be used as a parameter to other event group functions.
*
* \defgroup EventGroupHandle_t EventGroupHandle_t
* \ingroup EventGroup
*/
struct EventGroupDef_t;
typedef struct EventGroupDef_t * EventGroupHandle_t;
/*
* The type that holds event bits always matches TickType_t - therefore the
* number of bits it holds is set by configUSE_16_BIT_TICKS (16 bits if set to 1,
* 32 bits if set to 0.
*
* \defgroup EventBits_t EventBits_t
* \ingroup EventGroup
*/
typedef TickType_t EventBits_t;
/**
* event_groups.h
* <pre>
* EventGroupHandle_t xEventGroupCreate( void );
* </pre>
*
* Create a new event group.
*
* Internally, within the FreeRTOS implementation, event groups use a [small]
* block of memory, in which the event group's structure is stored. If an event
* groups is created using xEventGropuCreate() then the required memory is
* automatically dynamically allocated inside the xEventGroupCreate() function.
* (see https://www.FreeRTOS.org/a00111.html). If an event group is created
* using xEventGropuCreateStatic() then the application writer must instead
* provide the memory that will get used by the event group.
* xEventGroupCreateStatic() therefore allows an event group to be created
* without using any dynamic memory allocation.
*
* Although event groups are not related to ticks, for internal implementation
* reasons the number of bits available for use in an event group is dependent
* on the configUSE_16_BIT_TICKS setting in FreeRTOSConfig.h. If
* configUSE_16_BIT_TICKS is 1 then each event group contains 8 usable bits (bit
* 0 to bit 7). If configUSE_16_BIT_TICKS is set to 0 then each event group has
* 24 usable bits (bit 0 to bit 23). The EventBits_t type is used to store
* event bits within an event group.
*
* @return If the event group was created then a handle to the event group is
* returned. If there was insufficient FreeRTOS heap available to create the
* event group then NULL is returned. See https://www.FreeRTOS.org/a00111.html
*
* Example usage:
* <pre>
* // Declare a variable to hold the created event group.
* EventGroupHandle_t xCreatedEventGroup;
*
* // Attempt to create the event group.
* xCreatedEventGroup = xEventGroupCreate();
*
* // Was the event group created successfully?
* if( xCreatedEventGroup == NULL )
* {
* // The event group was not created because there was insufficient
* // FreeRTOS heap available.
* }
* else
* {
* // The event group was created.
* }
* </pre>
* \defgroup xEventGroupCreate xEventGroupCreate
* \ingroup EventGroup
*/
#if ( configSUPPORT_DYNAMIC_ALLOCATION == 1 )
EventGroupHandle_t xEventGroupCreate( void ) PRIVILEGED_FUNCTION;
#endif
/**
* event_groups.h
* <pre>
* EventGroupHandle_t xEventGroupCreateStatic( EventGroupHandle_t * pxEventGroupBuffer );
* </pre>
*
* Create a new event group.
*
* Internally, within the FreeRTOS implementation, event groups use a [small]
* block of memory, in which the event group's structure is stored. If an event
* groups is created using xEventGropuCreate() then the required memory is
* automatically dynamically allocated inside the xEventGroupCreate() function.
* (see https://www.FreeRTOS.org/a00111.html). If an event group is created
* using xEventGropuCreateStatic() then the application writer must instead
* provide the memory that will get used by the event group.
* xEventGroupCreateStatic() therefore allows an event group to be created
* without using any dynamic memory allocation.
*
* Although event groups are not related to ticks, for internal implementation
* reasons the number of bits available for use in an event group is dependent
* on the configUSE_16_BIT_TICKS setting in FreeRTOSConfig.h. If
* configUSE_16_BIT_TICKS is 1 then each event group contains 8 usable bits (bit
* 0 to bit 7). If configUSE_16_BIT_TICKS is set to 0 then each event group has
* 24 usable bits (bit 0 to bit 23). The EventBits_t type is used to store
* event bits within an event group.
*
* @param pxEventGroupBuffer pxEventGroupBuffer must point to a variable of type
* StaticEventGroup_t, which will be then be used to hold the event group's data
* structures, removing the need for the memory to be allocated dynamically.
*
* @return If the event group was created then a handle to the event group is
* returned. If pxEventGroupBuffer was NULL then NULL is returned.
*
* Example usage:
* <pre>
* // StaticEventGroup_t is a publicly accessible structure that has the same
* // size and alignment requirements as the real event group structure. It is
* // provided as a mechanism for applications to know the size of the event
* // group (which is dependent on the architecture and configuration file
* // settings) without breaking the strict data hiding policy by exposing the
* // real event group internals. This StaticEventGroup_t variable is passed
* // into the xSemaphoreCreateEventGroupStatic() function and is used to store
* // the event group's data structures
* StaticEventGroup_t xEventGroupBuffer;
*
* // Create the event group without dynamically allocating any memory.
* xEventGroup = xEventGroupCreateStatic( &xEventGroupBuffer );
* </pre>
*/
#if ( configSUPPORT_STATIC_ALLOCATION == 1 )
EventGroupHandle_t xEventGroupCreateStatic( StaticEventGroup_t * pxEventGroupBuffer ) PRIVILEGED_FUNCTION;
#endif
/**
* event_groups.h
* <pre>
* EventBits_t xEventGroupWaitBits( EventGroupHandle_t xEventGroup,
* const EventBits_t uxBitsToWaitFor,
* const BaseType_t xClearOnExit,
* const BaseType_t xWaitForAllBits,
* const TickType_t xTicksToWait );
* </pre>
*
* [Potentially] block to wait for one or more bits to be set within a
* previously created event group.
*
* This function cannot be called from an interrupt.
*
* @param xEventGroup The event group in which the bits are being tested. The
* event group must have previously been created using a call to
* xEventGroupCreate().
*
* @param uxBitsToWaitFor A bitwise value that indicates the bit or bits to test
* inside the event group. For example, to wait for bit 0 and/or bit 2 set
* uxBitsToWaitFor to 0x05. To wait for bits 0 and/or bit 1 and/or bit 2 set
* uxBitsToWaitFor to 0x07. Etc.
*
* @param xClearOnExit If xClearOnExit is set to pdTRUE then any bits within
* uxBitsToWaitFor that are set within the event group will be cleared before
* xEventGroupWaitBits() returns if the wait condition was met (if the function
* returns for a reason other than a timeout). If xClearOnExit is set to
* pdFALSE then the bits set in the event group are not altered when the call to
* xEventGroupWaitBits() returns.
*
* @param xWaitForAllBits If xWaitForAllBits is set to pdTRUE then
* xEventGroupWaitBits() will return when either all the bits in uxBitsToWaitFor
* are set or the specified block time expires. If xWaitForAllBits is set to
* pdFALSE then xEventGroupWaitBits() will return when any one of the bits set
* in uxBitsToWaitFor is set or the specified block time expires. The block
* time is specified by the xTicksToWait parameter.
*
* @param xTicksToWait The maximum amount of time (specified in 'ticks') to wait
* for one/all (depending on the xWaitForAllBits value) of the bits specified by
* uxBitsToWaitFor to become set.
*
* @return The value of the event group at the time either the bits being waited
* for became set, or the block time expired. Test the return value to know
* which bits were set. If xEventGroupWaitBits() returned because its timeout
* expired then not all the bits being waited for will be set. If
* xEventGroupWaitBits() returned because the bits it was waiting for were set
* then the returned value is the event group value before any bits were
* automatically cleared in the case that xClearOnExit parameter was set to
* pdTRUE.
*
* Example usage:
* <pre>
#define BIT_0 ( 1 << 0 )
#define BIT_4 ( 1 << 4 )
*
* void aFunction( EventGroupHandle_t xEventGroup )
* {
* EventBits_t uxBits;
* const TickType_t xTicksToWait = 100 / portTICK_PERIOD_MS;
*
* // Wait a maximum of 100ms for either bit 0 or bit 4 to be set within
* // the event group. Clear the bits before exiting.
* uxBits = xEventGroupWaitBits(
* xEventGroup, // The event group being tested.
* BIT_0 | BIT_4, // The bits within the event group to wait for.
* pdTRUE, // BIT_0 and BIT_4 should be cleared before returning.
* pdFALSE, // Don't wait for both bits, either bit will do.
* xTicksToWait ); // Wait a maximum of 100ms for either bit to be set.
*
* if( ( uxBits & ( BIT_0 | BIT_4 ) ) == ( BIT_0 | BIT_4 ) )
* {
* // xEventGroupWaitBits() returned because both bits were set.
* }
* else if( ( uxBits & BIT_0 ) != 0 )
* {
* // xEventGroupWaitBits() returned because just BIT_0 was set.
* }
* else if( ( uxBits & BIT_4 ) != 0 )
* {
* // xEventGroupWaitBits() returned because just BIT_4 was set.
* }
* else
* {
* // xEventGroupWaitBits() returned because xTicksToWait ticks passed
* // without either BIT_0 or BIT_4 becoming set.
* }
* }
* </pre>
* \defgroup xEventGroupWaitBits xEventGroupWaitBits
* \ingroup EventGroup
*/
EventBits_t xEventGroupWaitBits( EventGroupHandle_t xEventGroup,
const EventBits_t uxBitsToWaitFor,
const BaseType_t xClearOnExit,
const BaseType_t xWaitForAllBits,
TickType_t xTicksToWait ) PRIVILEGED_FUNCTION;
/**
* event_groups.h
* <pre>
* EventBits_t xEventGroupClearBits( EventGroupHandle_t xEventGroup, const EventBits_t uxBitsToClear );
* </pre>
*
* Clear bits within an event group. This function cannot be called from an
* interrupt.
*
* @param xEventGroup The event group in which the bits are to be cleared.
*
* @param uxBitsToClear A bitwise value that indicates the bit or bits to clear
* in the event group. For example, to clear bit 3 only, set uxBitsToClear to
* 0x08. To clear bit 3 and bit 0 set uxBitsToClear to 0x09.
*
* @return The value of the event group before the specified bits were cleared.
*
* Example usage:
* <pre>
#define BIT_0 ( 1 << 0 )
#define BIT_4 ( 1 << 4 )
*
* void aFunction( EventGroupHandle_t xEventGroup )
* {
* EventBits_t uxBits;
*
* // Clear bit 0 and bit 4 in xEventGroup.
* uxBits = xEventGroupClearBits(
* xEventGroup, // The event group being updated.
* BIT_0 | BIT_4 );// The bits being cleared.
*
* if( ( uxBits & ( BIT_0 | BIT_4 ) ) == ( BIT_0 | BIT_4 ) )
* {
* // Both bit 0 and bit 4 were set before xEventGroupClearBits() was
* // called. Both will now be clear (not set).
* }
* else if( ( uxBits & BIT_0 ) != 0 )
* {
* // Bit 0 was set before xEventGroupClearBits() was called. It will
* // now be clear.
* }
* else if( ( uxBits & BIT_4 ) != 0 )
* {
* // Bit 4 was set before xEventGroupClearBits() was called. It will
* // now be clear.
* }
* else
* {
* // Neither bit 0 nor bit 4 were set in the first place.
* }
* }
* </pre>
* \defgroup xEventGroupClearBits xEventGroupClearBits
* \ingroup EventGroup
*/
EventBits_t xEventGroupClearBits( EventGroupHandle_t xEventGroup,
const EventBits_t uxBitsToClear ) PRIVILEGED_FUNCTION;
/**
* event_groups.h
* <pre>
* BaseType_t xEventGroupClearBitsFromISR( EventGroupHandle_t xEventGroup, const EventBits_t uxBitsToSet );
* </pre>
*
* A version of xEventGroupClearBits() that can be called from an interrupt.
*
* Setting bits in an event group is not a deterministic operation because there
* are an unknown number of tasks that may be waiting for the bit or bits being
* set. FreeRTOS does not allow nondeterministic operations to be performed
* while interrupts are disabled, so protects event groups that are accessed
* from tasks by suspending the scheduler rather than disabling interrupts. As
* a result event groups cannot be accessed directly from an interrupt service
* routine. Therefore xEventGroupClearBitsFromISR() sends a message to the
* timer task to have the clear operation performed in the context of the timer
* task.
*
* @param xEventGroup The event group in which the bits are to be cleared.
*
* @param uxBitsToClear A bitwise value that indicates the bit or bits to clear.
* For example, to clear bit 3 only, set uxBitsToClear to 0x08. To clear bit 3
* and bit 0 set uxBitsToClear to 0x09.
*
* @return If the request to execute the function was posted successfully then
* pdPASS is returned, otherwise pdFALSE is returned. pdFALSE will be returned
* if the timer service queue was full.
*
* Example usage:
* <pre>
#define BIT_0 ( 1 << 0 )
#define BIT_4 ( 1 << 4 )
*
* // An event group which it is assumed has already been created by a call to
* // xEventGroupCreate().
* EventGroupHandle_t xEventGroup;
*
* void anInterruptHandler( void )
* {
* // Clear bit 0 and bit 4 in xEventGroup.
* xResult = xEventGroupClearBitsFromISR(
* xEventGroup, // The event group being updated.
* BIT_0 | BIT_4 ); // The bits being set.
*
* if( xResult == pdPASS )
* {
* // The message was posted successfully.
* }
* }
* </pre>
* \defgroup xEventGroupClearBitsFromISR xEventGroupClearBitsFromISR
* \ingroup EventGroup
*/
#if ( configUSE_TRACE_FACILITY == 1 )
BaseType_t xEventGroupClearBitsFromISR( EventGroupHandle_t xEventGroup,
const EventBits_t uxBitsToClear ) PRIVILEGED_FUNCTION;
#else
#define xEventGroupClearBitsFromISR( xEventGroup, uxBitsToClear ) \
xTimerPendFunctionCallFromISR( vEventGroupClearBitsCallback, ( void * ) xEventGroup, ( uint32_t ) uxBitsToClear, NULL )
#endif
/**
* event_groups.h
* <pre>
* EventBits_t xEventGroupSetBits( EventGroupHandle_t xEventGroup, const EventBits_t uxBitsToSet );
* </pre>
*
* Set bits within an event group.
* This function cannot be called from an interrupt. xEventGroupSetBitsFromISR()
* is a version that can be called from an interrupt.
*
* Setting bits in an event group will automatically unblock tasks that are
* blocked waiting for the bits.
*
* @param xEventGroup The event group in which the bits are to be set.
*
* @param uxBitsToSet A bitwise value that indicates the bit or bits to set.
* For example, to set bit 3 only, set uxBitsToSet to 0x08. To set bit 3
* and bit 0 set uxBitsToSet to 0x09.
*
* @return The value of the event group at the time the call to
* xEventGroupSetBits() returns. There are two reasons why the returned value
* might have the bits specified by the uxBitsToSet parameter cleared. First,
* if setting a bit results in a task that was waiting for the bit leaving the
* blocked state then it is possible the bit will be cleared automatically
* (see the xClearBitOnExit parameter of xEventGroupWaitBits()). Second, any
* unblocked (or otherwise Ready state) task that has a priority above that of
* the task that called xEventGroupSetBits() will execute and may change the
* event group value before the call to xEventGroupSetBits() returns.
*
* Example usage:
* <pre>
#define BIT_0 ( 1 << 0 )
#define BIT_4 ( 1 << 4 )
*
* void aFunction( EventGroupHandle_t xEventGroup )
* {
* EventBits_t uxBits;
*
* // Set bit 0 and bit 4 in xEventGroup.
* uxBits = xEventGroupSetBits(
* xEventGroup, // The event group being updated.
* BIT_0 | BIT_4 );// The bits being set.
*
* if( ( uxBits & ( BIT_0 | BIT_4 ) ) == ( BIT_0 | BIT_4 ) )
* {
* // Both bit 0 and bit 4 remained set when the function returned.
* }
* else if( ( uxBits & BIT_0 ) != 0 )
* {
* // Bit 0 remained set when the function returned, but bit 4 was
* // cleared. It might be that bit 4 was cleared automatically as a
* // task that was waiting for bit 4 was removed from the Blocked
* // state.
* }
* else if( ( uxBits & BIT_4 ) != 0 )
* {
* // Bit 4 remained set when the function returned, but bit 0 was
* // cleared. It might be that bit 0 was cleared automatically as a
* // task that was waiting for bit 0 was removed from the Blocked
* // state.
* }
* else
* {
* // Neither bit 0 nor bit 4 remained set. It might be that a task
* // was waiting for both of the bits to be set, and the bits were
* // cleared as the task left the Blocked state.
* }
* }
* </pre>
* \defgroup xEventGroupSetBits xEventGroupSetBits
* \ingroup EventGroup
*/
EventBits_t xEventGroupSetBits( EventGroupHandle_t xEventGroup,
const EventBits_t uxBitsToSet ) PRIVILEGED_FUNCTION;
/**
* event_groups.h
* <pre>
* BaseType_t xEventGroupSetBitsFromISR( EventGroupHandle_t xEventGroup, const EventBits_t uxBitsToSet, BaseType_t *pxHigherPriorityTaskWoken );
* </pre>
*
* A version of xEventGroupSetBits() that can be called from an interrupt.
*
* Setting bits in an event group is not a deterministic operation because there
* are an unknown number of tasks that may be waiting for the bit or bits being
* set. FreeRTOS does not allow nondeterministic operations to be performed in
* interrupts or from critical sections. Therefore xEventGroupSetBitsFromISR()
* sends a message to the timer task to have the set operation performed in the
* context of the timer task - where a scheduler lock is used in place of a
* critical section.
*
* @param xEventGroup The event group in which the bits are to be set.
*
* @param uxBitsToSet A bitwise value that indicates the bit or bits to set.
* For example, to set bit 3 only, set uxBitsToSet to 0x08. To set bit 3
* and bit 0 set uxBitsToSet to 0x09.
*
* @param pxHigherPriorityTaskWoken As mentioned above, calling this function
* will result in a message being sent to the timer daemon task. If the
* priority of the timer daemon task is higher than the priority of the
* currently running task (the task the interrupt interrupted) then
* *pxHigherPriorityTaskWoken will be set to pdTRUE by
* xEventGroupSetBitsFromISR(), indicating that a context switch should be
* requested before the interrupt exits. For that reason
* *pxHigherPriorityTaskWoken must be initialised to pdFALSE. See the
* example code below.
*
* @return If the request to execute the function was posted successfully then
* pdPASS is returned, otherwise pdFALSE is returned. pdFALSE will be returned
* if the timer service queue was full.
*
* Example usage:
* <pre>
#define BIT_0 ( 1 << 0 )
#define BIT_4 ( 1 << 4 )
*
* // An event group which it is assumed has already been created by a call to
* // xEventGroupCreate().
* EventGroupHandle_t xEventGroup;
*
* void anInterruptHandler( void )
* {
* BaseType_t xHigherPriorityTaskWoken, xResult;
*
* // xHigherPriorityTaskWoken must be initialised to pdFALSE.
* xHigherPriorityTaskWoken = pdFALSE;
*
* // Set bit 0 and bit 4 in xEventGroup.
* xResult = xEventGroupSetBitsFromISR(
* xEventGroup, // The event group being updated.
* BIT_0 | BIT_4 // The bits being set.
* &xHigherPriorityTaskWoken );
*
* // Was the message posted successfully?
* if( xResult == pdPASS )
* {
* // If xHigherPriorityTaskWoken is now set to pdTRUE then a context
* // switch should be requested. The macro used is port specific and
* // will be either portYIELD_FROM_ISR() or portEND_SWITCHING_ISR() -
* // refer to the documentation page for the port being used.
* portYIELD_FROM_ISR( xHigherPriorityTaskWoken );
* }
* }
* </pre>
* \defgroup xEventGroupSetBitsFromISR xEventGroupSetBitsFromISR
* \ingroup EventGroup
*/
#if ( configUSE_TRACE_FACILITY == 1 )
BaseType_t xEventGroupSetBitsFromISR( EventGroupHandle_t xEventGroup,
const EventBits_t uxBitsToSet,
BaseType_t * pxHigherPriorityTaskWoken ) PRIVILEGED_FUNCTION;
#else
#define xEventGroupSetBitsFromISR( xEventGroup, uxBitsToSet, pxHigherPriorityTaskWoken ) \
xTimerPendFunctionCallFromISR( vEventGroupSetBitsCallback, ( void * ) xEventGroup, ( uint32_t ) uxBitsToSet, pxHigherPriorityTaskWoken )
#endif
/**
* event_groups.h
* <pre>
* EventBits_t xEventGroupSync( EventGroupHandle_t xEventGroup,
* const EventBits_t uxBitsToSet,
* const EventBits_t uxBitsToWaitFor,
* TickType_t xTicksToWait );
* </pre>
*
* Atomically set bits within an event group, then wait for a combination of
* bits to be set within the same event group. This functionality is typically
* used to synchronise multiple tasks, where each task has to wait for the other
* tasks to reach a synchronisation point before proceeding.
*
* This function cannot be used from an interrupt.
*
* The function will return before its block time expires if the bits specified
* by the uxBitsToWait parameter are set, or become set within that time. In
* this case all the bits specified by uxBitsToWait will be automatically
* cleared before the function returns.
*
* @param xEventGroup The event group in which the bits are being tested. The
* event group must have previously been created using a call to
* xEventGroupCreate().
*
* @param uxBitsToSet The bits to set in the event group before determining
* if, and possibly waiting for, all the bits specified by the uxBitsToWait
* parameter are set.
*
* @param uxBitsToWaitFor A bitwise value that indicates the bit or bits to test
* inside the event group. For example, to wait for bit 0 and bit 2 set
* uxBitsToWaitFor to 0x05. To wait for bits 0 and bit 1 and bit 2 set
* uxBitsToWaitFor to 0x07. Etc.
*
* @param xTicksToWait The maximum amount of time (specified in 'ticks') to wait
* for all of the bits specified by uxBitsToWaitFor to become set.
*
* @return The value of the event group at the time either the bits being waited
* for became set, or the block time expired. Test the return value to know
* which bits were set. If xEventGroupSync() returned because its timeout
* expired then not all the bits being waited for will be set. If
* xEventGroupSync() returned because all the bits it was waiting for were
* set then the returned value is the event group value before any bits were
* automatically cleared.
*
* Example usage:
* <pre>
* // Bits used by the three tasks.
#define TASK_0_BIT ( 1 << 0 )
#define TASK_1_BIT ( 1 << 1 )
#define TASK_2_BIT ( 1 << 2 )
*
#define ALL_SYNC_BITS ( TASK_0_BIT | TASK_1_BIT | TASK_2_BIT )
*
* // Use an event group to synchronise three tasks. It is assumed this event
* // group has already been created elsewhere.
* EventGroupHandle_t xEventBits;
*
* void vTask0( void *pvParameters )
* {
* EventBits_t uxReturn;
* TickType_t xTicksToWait = 100 / portTICK_PERIOD_MS;
*
* for( ;; )
* {
* // Perform task functionality here.
*
* // Set bit 0 in the event flag to note this task has reached the
* // sync point. The other two tasks will set the other two bits defined
* // by ALL_SYNC_BITS. All three tasks have reached the synchronisation
* // point when all the ALL_SYNC_BITS are set. Wait a maximum of 100ms
* // for this to happen.
* uxReturn = xEventGroupSync( xEventBits, TASK_0_BIT, ALL_SYNC_BITS, xTicksToWait );
*
* if( ( uxReturn & ALL_SYNC_BITS ) == ALL_SYNC_BITS )
* {
* // All three tasks reached the synchronisation point before the call
* // to xEventGroupSync() timed out.
* }
* }
* }
*
* void vTask1( void *pvParameters )
* {
* for( ;; )
* {
* // Perform task functionality here.
*
* // Set bit 1 in the event flag to note this task has reached the
* // synchronisation point. The other two tasks will set the other two
* // bits defined by ALL_SYNC_BITS. All three tasks have reached the
* // synchronisation point when all the ALL_SYNC_BITS are set. Wait
* // indefinitely for this to happen.
* xEventGroupSync( xEventBits, TASK_1_BIT, ALL_SYNC_BITS, portMAX_DELAY );
*
* // xEventGroupSync() was called with an indefinite block time, so
* // this task will only reach here if the synchronisation was made by all
* // three tasks, so there is no need to test the return value.
* }
* }
*
* void vTask2( void *pvParameters )
* {
* for( ;; )
* {
* // Perform task functionality here.
*
* // Set bit 2 in the event flag to note this task has reached the
* // synchronisation point. The other two tasks will set the other two
* // bits defined by ALL_SYNC_BITS. All three tasks have reached the
* // synchronisation point when all the ALL_SYNC_BITS are set. Wait
* // indefinitely for this to happen.
* xEventGroupSync( xEventBits, TASK_2_BIT, ALL_SYNC_BITS, portMAX_DELAY );
*
* // xEventGroupSync() was called with an indefinite block time, so
* // this task will only reach here if the synchronisation was made by all
* // three tasks, so there is no need to test the return value.
* }
* }
*
* </pre>
* \defgroup xEventGroupSync xEventGroupSync
* \ingroup EventGroup
*/
EventBits_t xEventGroupSync( EventGroupHandle_t xEventGroup,
const EventBits_t uxBitsToSet,
const EventBits_t uxBitsToWaitFor,
TickType_t xTicksToWait ) PRIVILEGED_FUNCTION;
/**
* event_groups.h
* <pre>
* EventBits_t xEventGroupGetBits( EventGroupHandle_t xEventGroup );
* </pre>
*
* Returns the current value of the bits in an event group. This function
* cannot be used from an interrupt.
*
* @param xEventGroup The event group being queried.
*
* @return The event group bits at the time xEventGroupGetBits() was called.
*
* \defgroup xEventGroupGetBits xEventGroupGetBits
* \ingroup EventGroup
*/
#define xEventGroupGetBits( xEventGroup ) xEventGroupClearBits( xEventGroup, 0 )
/**
* event_groups.h
* <pre>
* EventBits_t xEventGroupGetBitsFromISR( EventGroupHandle_t xEventGroup );
* </pre>
*
* A version of xEventGroupGetBits() that can be called from an ISR.
*
* @param xEventGroup The event group being queried.
*
* @return The event group bits at the time xEventGroupGetBitsFromISR() was called.
*
* \defgroup xEventGroupGetBitsFromISR xEventGroupGetBitsFromISR
* \ingroup EventGroup
*/
EventBits_t xEventGroupGetBitsFromISR( EventGroupHandle_t xEventGroup ) PRIVILEGED_FUNCTION;
/**
* event_groups.h
* <pre>
* void xEventGroupDelete( EventGroupHandle_t xEventGroup );
* </pre>
*
* Delete an event group that was previously created by a call to
* xEventGroupCreate(). Tasks that are blocked on the event group will be
* unblocked and obtain 0 as the event group's value.
*
* @param xEventGroup The event group being deleted.
*/
void vEventGroupDelete( EventGroupHandle_t xEventGroup ) PRIVILEGED_FUNCTION;
/* For internal use only. */
void vEventGroupSetBitsCallback( void * pvEventGroup,
const uint32_t ulBitsToSet ) PRIVILEGED_FUNCTION;
void vEventGroupClearBitsCallback( void * pvEventGroup,
const uint32_t ulBitsToClear ) PRIVILEGED_FUNCTION;
#if ( configUSE_TRACE_FACILITY == 1 )
UBaseType_t uxEventGroupGetNumber( void * xEventGroup ) PRIVILEGED_FUNCTION;
void vEventGroupSetNumber( void * xEventGroup,
UBaseType_t uxEventGroupNumber ) PRIVILEGED_FUNCTION;
#endif
/* *INDENT-OFF* */
#ifdef __cplusplus
}
#endif
/* *INDENT-ON* */
#endif /* EVENT_GROUPS_H */