David Fletcher
Update revision to use TI's mqtt and Freertos.
Dependencies: mbed client server
Fork of
cc3100_Test_mqtt_CM3
by 
David Fletcher
Diff: FreeRTOS_V8_2_1/source/include/event_groups.h
- Revision:
- 3:a8c249046181
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/FreeRTOS_V8_2_1/source/include/event_groups.h Thu Sep 03 14:02:37 2015 +0000
@@ -0,0 +1,731 @@
+/*
+ FreeRTOS V8.2.1 - Copyright (C) 2015 Real Time Engineers Ltd.
+ All rights reserved
+
+ VISIT http://www.FreeRTOS.org TO ENSURE YOU ARE USING THE LATEST VERSION.
+
+ This file is part of the FreeRTOS distribution.
+
+ FreeRTOS is free software; you can redistribute it and/or modify it under
+ the terms of the GNU General Public License (version 2) as published by the
+ Free Software Foundation >>!AND MODIFIED BY!<< the FreeRTOS exception.
+
+ ***************************************************************************
+ >>! NOTE: The modification to the GPL is included to allow you to !<<
+ >>! distribute a combined work that includes FreeRTOS without being !<<
+ >>! obliged to provide the source code for proprietary components !<<
+ >>! outside of the FreeRTOS kernel. !<<
+ ***************************************************************************
+
+ FreeRTOS is distributed in the hope that it will be useful, but WITHOUT ANY
+ WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+ FOR A PARTICULAR PURPOSE. Full license text is available on the following
+ link: http://www.freertos.org/a00114.html
+
+ ***************************************************************************
+ * *
+ * FreeRTOS provides completely free yet professionally developed, *
+ * robust, strictly quality controlled, supported, and cross *
+ * platform software that is more than just the market leader, it *
+ * is the industry's de facto standard. *
+ * *
+ * Help yourself get started quickly while simultaneously helping *
+ * to support the FreeRTOS project by purchasing a FreeRTOS *
+ * tutorial book, reference manual, or both: *
+ * http://www.FreeRTOS.org/Documentation *
+ * *
+ ***************************************************************************
+
+ http://www.FreeRTOS.org/FAQHelp.html - Having a problem? Start by reading
+ the FAQ page "My application does not run, what could be wrong?". Have you
+ defined configASSERT()?
+
+ http://www.FreeRTOS.org/support - In return for receiving this top quality
+ embedded software for free we request you assist our global community by
+ participating in the support forum.
+
+ http://www.FreeRTOS.org/training - Investing in training allows your team to
+ be as productive as possible as early as possible. Now you can receive
+ FreeRTOS training directly from Richard Barry, CEO of Real Time Engineers
+ Ltd, and the world's leading authority on the world's leading RTOS.
+
+ http://www.FreeRTOS.org/plus - A selection of FreeRTOS ecosystem products,
+ including FreeRTOS+Trace - an indispensable productivity tool, a DOS
+ compatible FAT file system, and our tiny thread aware UDP/IP stack.
+
+ http://www.FreeRTOS.org/labs - Where new FreeRTOS products go to incubate.
+ Come and try FreeRTOS+TCP, our new open source TCP/IP stack for FreeRTOS.
+
+ http://www.OpenRTOS.com - Real Time Engineers ltd. license FreeRTOS to High
+ Integrity Systems ltd. to sell under the OpenRTOS brand. Low cost OpenRTOS
+ licenses offer ticketed support, indemnification and commercial middleware.
+
+ http://www.SafeRTOS.com - High Integrity Systems also provide a safety
+ engineered and independently SIL3 certified version for use in safety and
+ mission critical applications that require provable dependability.
+
+ 1 tab == 4 spaces!
+*/
+
+#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
+
+#include "timers.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * 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
+ */
+typedef void * 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. This function cannot be called from an interrupt.
+ *
+ * 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 http://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
+ */
+EventGroupHandle_t xEventGroupCreate( void ) PRIVILEGED_FUNCTION;
+
+/**
+ * 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 xEventGroupSetBitsFromISR xEventGroupSetBitsFromISR
+ * \ingroup EventGroup
+ */
+#if( configUSE_TRACE_FACILITY == 1 )
+ BaseType_t xEventGroupClearBitsFromISR( EventGroupHandle_t xEventGroup, const EventBits_t uxBitsToSet );
+#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 xEventGroupSetBitFromISR()
+ * 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 );
+#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 syncrhonisation 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 syncrhonisation 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 );
+
+/**
+ * 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 );
+
+/* For internal use only. */
+void vEventGroupSetBitsCallback( void *pvEventGroup, const uint32_t ulBitsToSet );
+void vEventGroupClearBitsCallback( void *pvEventGroup, const uint32_t ulBitsToClear );
+
+#if (configUSE_TRACE_FACILITY == 1)
+ UBaseType_t uxEventGroupGetNumber( void* xEventGroup );
+#endif
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* EVENT_GROUPS_H */
+
+
+