| /* |
| * FreeRTOS Kernel <DEVELOPMENT BRANCH> |
| * 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'). |
| */ |
| |
| |
| |
| /** |
| * 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 |
| * @code{c} |
| * EventGroupHandle_t xEventGroupCreate( void ); |
| * @endcode |
| * |
| * 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 xEventGroupCreate() 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 xEventGroupCreateStatic() 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: |
| * @code{c} |
| * // 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. |
| * } |
| * @endcode |
| * \defgroup xEventGroupCreate xEventGroupCreate |
| * \ingroup EventGroup |
| */ |
| #if ( configSUPPORT_DYNAMIC_ALLOCATION == 1 ) |
| EventGroupHandle_t xEventGroupCreate( void ) PRIVILEGED_FUNCTION; |
| #endif |
| |
| /** |
| * event_groups.h |
| * @code{c} |
| * EventGroupHandle_t xEventGroupCreateStatic( EventGroupHandle_t * pxEventGroupBuffer ); |
| * @endcode |
| * |
| * 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 xEventGroupCreate() 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 xEventGroupCreateStatic() 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: |
| * @code{c} |
| * // 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 ); |
| * @endcode |
| */ |
| #if ( configSUPPORT_STATIC_ALLOCATION == 1 ) |
| EventGroupHandle_t xEventGroupCreateStatic( StaticEventGroup_t * pxEventGroupBuffer ) PRIVILEGED_FUNCTION; |
| #endif |
| |
| /** |
| * event_groups.h |
| * @code{c} |
| * EventBits_t xEventGroupWaitBits( EventGroupHandle_t xEventGroup, |
| * const EventBits_t uxBitsToWaitFor, |
| * const BaseType_t xClearOnExit, |
| * const BaseType_t xWaitForAllBits, |
| * const TickType_t xTicksToWait ); |
| * @endcode |
| * |
| * [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. A value of portMAX_DELAY can be used to block |
| * indefinitely (provided INCLUDE_vTaskSuspend is set to 1 in FreeRTOSConfig.h). |
| * |
| * @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: |
| * @code{c} |
| * #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. |
| * } |
| * } |
| * @endcode |
| * \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 |
| * @code{c} |
| * EventBits_t xEventGroupClearBits( EventGroupHandle_t xEventGroup, const EventBits_t uxBitsToClear ); |
| * @endcode |
| * |
| * 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: |
| * @code{c} |
| * #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. |
| * } |
| * } |
| * @endcode |
| * \defgroup xEventGroupClearBits xEventGroupClearBits |
| * \ingroup EventGroup |
| */ |
| EventBits_t xEventGroupClearBits( EventGroupHandle_t xEventGroup, |
| const EventBits_t uxBitsToClear ) PRIVILEGED_FUNCTION; |
| |
| /** |
| * event_groups.h |
| * @code{c} |
| * BaseType_t xEventGroupClearBitsFromISR( EventGroupHandle_t xEventGroup, const EventBits_t uxBitsToSet ); |
| * @endcode |
| * |
| * 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. |
| * |
| * @note If this function returns pdPASS then the timer task is ready to run |
| * and a portYIELD_FROM_ISR(pdTRUE) should be executed to perform the needed |
| * clear on the event group. This behavior is different from |
| * xEventGroupSetBitsFromISR because the parameter xHigherPriorityTaskWoken is |
| * not present. |
| * |
| * @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: |
| * @code{c} |
| * #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. |
| * portYIELD_FROM_ISR(pdTRUE); |
| * } |
| * } |
| * @endcode |
| * \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 |
| * @code{c} |
| * EventBits_t xEventGroupSetBits( EventGroupHandle_t xEventGroup, const EventBits_t uxBitsToSet ); |
| * @endcode |
| * |
| * 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: |
| * @code{c} |
| * #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. |
| * } |
| * } |
| * @endcode |
| * \defgroup xEventGroupSetBits xEventGroupSetBits |
| * \ingroup EventGroup |
| */ |
| EventBits_t xEventGroupSetBits( EventGroupHandle_t xEventGroup, |
| const EventBits_t uxBitsToSet ) PRIVILEGED_FUNCTION; |
| |
| /** |
| * event_groups.h |
| * @code{c} |
| * BaseType_t xEventGroupSetBitsFromISR( EventGroupHandle_t xEventGroup, const EventBits_t uxBitsToSet, BaseType_t *pxHigherPriorityTaskWoken ); |
| * @endcode |
| * |
| * 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: |
| * @code{c} |
| * #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 ); |
| * } |
| * } |
| * @endcode |
| * \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 |
| * @code{c} |
| * EventBits_t xEventGroupSync( EventGroupHandle_t xEventGroup, |
| * const EventBits_t uxBitsToSet, |
| * const EventBits_t uxBitsToWaitFor, |
| * TickType_t xTicksToWait ); |
| * @endcode |
| * |
| * 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: |
| * @code{c} |
| * // 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. |
| * } |
| * } |
| * |
| * @endcode |
| * \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 |
| * @code{c} |
| * EventBits_t xEventGroupGetBits( EventGroupHandle_t xEventGroup ); |
| * @endcode |
| * |
| * 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 |
| * @code{c} |
| * EventBits_t xEventGroupGetBitsFromISR( EventGroupHandle_t xEventGroup ); |
| * @endcode |
| * |
| * 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 |
| * @code{c} |
| * void xEventGroupDelete( EventGroupHandle_t xEventGroup ); |
| * @endcode |
| * |
| * 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 */ |
