atomic.h

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/*
 * FreeRTOS Kernel V10.4.3
 * Copyright (C) 2020 Amazon.com, Inc. or its affiliates.  All Rights Reserved.
 *
 * 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 ATOMIC_H
#define ATOMIC_H

#ifndef INC_FREERTOS_H
    #error "include FreeRTOS.h must appear in source files before include atomic.h"
#endif

/* Standard includes. */
#include <stdint.h>

/* *INDENT-OFF* */
#ifdef __cplusplus
    extern "C" {
#endif
/* *INDENT-ON* */

/*
 * Port specific definitions -- entering/exiting critical section.
 * Refer template -- ./lib/FreeRTOS/portable/Compiler/Arch/portmacro.h
 *
 * Every call to ATOMIC_EXIT_CRITICAL() must be closely paired with
 * ATOMIC_ENTER_CRITICAL().
 *
 */
#if defined( portSET_INTERRUPT_MASK_FROM_ISR )

/* Nested interrupt scheme is supported in this port. */
    #define ATOMIC_ENTER_CRITICAL() \
    UBaseType_t uxCriticalSectionType = portSET_INTERRUPT_MASK_FROM_ISR()

    #define ATOMIC_EXIT_CRITICAL() \
    portCLEAR_INTERRUPT_MASK_FROM_ISR( uxCriticalSectionType )

#else

/* Nested interrupt scheme is NOT supported in this port. */
    #define ATOMIC_ENTER_CRITICAL()    portENTER_CRITICAL()
    #define ATOMIC_EXIT_CRITICAL()     portEXIT_CRITICAL()

#endif /* portSET_INTERRUPT_MASK_FROM_ISR() */

/*
 * Port specific definition -- "always inline".
 * Inline is compiler specific, and may not always get inlined depending on your
 * optimization level.  Also, inline is considered as performance optimization
 * for atomic.  Thus, if portFORCE_INLINE is not provided by portmacro.h,
 * instead of resulting error, simply define it away.
 */
#ifndef portFORCE_INLINE
    #define portFORCE_INLINE
#endif

#define ATOMIC_COMPARE_AND_SWAP_SUCCESS    0x1U     
#define ATOMIC_COMPARE_AND_SWAP_FAILURE    0x0U     
/*----------------------------- Swap && CAS ------------------------------*/

static portFORCE_INLINE uint32_t Atomic_CompareAndSwap_u32( uint32_t volatile * pulDestination,
                                                            uint32_t ulExchange,
                                                            uint32_t ulComparand )
{
    uint32_t ulReturnValue;

    ATOMIC_ENTER_CRITICAL();
    {
        if( *pulDestination == ulComparand )
        {
            *pulDestination = ulExchange;
            ulReturnValue = ATOMIC_COMPARE_AND_SWAP_SUCCESS;
        }
        else
        {
            ulReturnValue = ATOMIC_COMPARE_AND_SWAP_FAILURE;
        }
    }
    ATOMIC_EXIT_CRITICAL();

    return ulReturnValue;
}
/*-----------------------------------------------------------*/

static portFORCE_INLINE void * Atomic_SwapPointers_p32( void * volatile * ppvDestination,
                                                        void * pvExchange )
{
    void * pReturnValue;

    ATOMIC_ENTER_CRITICAL();
    {
        pReturnValue = *ppvDestination;
        *ppvDestination = pvExchange;
    }
    ATOMIC_EXIT_CRITICAL();

    return pReturnValue;
}
/*-----------------------------------------------------------*/

static portFORCE_INLINE uint32_t Atomic_CompareAndSwapPointers_p32( void * volatile * ppvDestination,
                                                                    void * pvExchange,
                                                                    void * pvComparand )
{
    uint32_t ulReturnValue = ATOMIC_COMPARE_AND_SWAP_FAILURE;

    ATOMIC_ENTER_CRITICAL();
    {
        if( *ppvDestination == pvComparand )
        {
            *ppvDestination = pvExchange;
            ulReturnValue = ATOMIC_COMPARE_AND_SWAP_SUCCESS;
        }
    }
    ATOMIC_EXIT_CRITICAL();

    return ulReturnValue;
}


/*----------------------------- Arithmetic ------------------------------*/

static portFORCE_INLINE uint32_t Atomic_Add_u32( uint32_t volatile * pulAddend,
                                                 uint32_t ulCount )
{
    uint32_t ulCurrent;

    ATOMIC_ENTER_CRITICAL();
    {
        ulCurrent = *pulAddend;
        *pulAddend += ulCount;
    }
    ATOMIC_EXIT_CRITICAL();

    return ulCurrent;
}
/*-----------------------------------------------------------*/

static portFORCE_INLINE uint32_t Atomic_Subtract_u32( uint32_t volatile * pulAddend,
                                                      uint32_t ulCount )
{
    uint32_t ulCurrent;

    ATOMIC_ENTER_CRITICAL();
    {
        ulCurrent = *pulAddend;
        *pulAddend -= ulCount;
    }
    ATOMIC_EXIT_CRITICAL();

    return ulCurrent;
}
/*-----------------------------------------------------------*/

static portFORCE_INLINE uint32_t Atomic_Increment_u32( uint32_t volatile * pulAddend )
{
    uint32_t ulCurrent;

    ATOMIC_ENTER_CRITICAL();
    {
        ulCurrent = *pulAddend;
        *pulAddend += 1;
    }
    ATOMIC_EXIT_CRITICAL();

    return ulCurrent;
}
/*-----------------------------------------------------------*/

static portFORCE_INLINE uint32_t Atomic_Decrement_u32( uint32_t volatile * pulAddend )
{
    uint32_t ulCurrent;

    ATOMIC_ENTER_CRITICAL();
    {
        ulCurrent = *pulAddend;
        *pulAddend -= 1;
    }
    ATOMIC_EXIT_CRITICAL();

    return ulCurrent;
}

/*----------------------------- Bitwise Logical ------------------------------*/

static portFORCE_INLINE uint32_t Atomic_OR_u32( uint32_t volatile * pulDestination,
                                                uint32_t ulValue )
{
    uint32_t ulCurrent;

    ATOMIC_ENTER_CRITICAL();
    {
        ulCurrent = *pulDestination;
        *pulDestination |= ulValue;
    }
    ATOMIC_EXIT_CRITICAL();

    return ulCurrent;
}
/*-----------------------------------------------------------*/

static portFORCE_INLINE uint32_t Atomic_AND_u32( uint32_t volatile * pulDestination,
                                                 uint32_t ulValue )
{
    uint32_t ulCurrent;

    ATOMIC_ENTER_CRITICAL();
    {
        ulCurrent = *pulDestination;
        *pulDestination &= ulValue;
    }
    ATOMIC_EXIT_CRITICAL();

    return ulCurrent;
}
/*-----------------------------------------------------------*/

static portFORCE_INLINE uint32_t Atomic_NAND_u32( uint32_t volatile * pulDestination,
                                                  uint32_t ulValue )
{
    uint32_t ulCurrent;

    ATOMIC_ENTER_CRITICAL();
    {
        ulCurrent = *pulDestination;
        *pulDestination = ~( ulCurrent & ulValue );
    }
    ATOMIC_EXIT_CRITICAL();

    return ulCurrent;
}
/*-----------------------------------------------------------*/

static portFORCE_INLINE uint32_t Atomic_XOR_u32( uint32_t volatile * pulDestination,
                                                 uint32_t ulValue )
{
    uint32_t ulCurrent;

    ATOMIC_ENTER_CRITICAL();
    {
        ulCurrent = *pulDestination;
        *pulDestination ^= ulValue;
    }
    ATOMIC_EXIT_CRITICAL();

    return ulCurrent;
}

/* *INDENT-OFF* */
#ifdef __cplusplus
    }
#endif
/* *INDENT-ON* */

#endif /* ATOMIC_H */