stream_buffer.h

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/*
 * FreeRTOS Kernel V10.0.0
 * Copyright (C) 2017 Amazon.com, Inc. or its affiliates.  All Rights Reserved.
 *
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 * this software and associated documentation files (the "Software"), to deal in
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 * 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:
 *
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 * FreeRTOS name, please do so in a fair use way that does not cause confusion.
 *
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/*
 * Stream buffers are used to send a continuous stream of data from one task or
 * interrupt to another.  Their implementation is light weight, making them
 * particularly suited for interrupt to task and core to core communication
 * scenarios.
 *
 * ***NOTE***:  Uniquely among FreeRTOS objects, the stream buffer
 * implementation (so also the message buffer implementation, as message buffers
 * are built on top of stream buffers) assumes there is only one task or
 * interrupt that will write to the buffer (the writer), and only one task or
 * interrupt that will read from the buffer (the reader).  It is safe for the
 * writer and reader to be different tasks or interrupts, but, unlike other
 * FreeRTOS objects, it is not safe to have multiple different writers or
 * multiple different readers.  If there are to be multiple different writers
 * then the application writer must place each call to a writing API function
 * (such as xStreamBufferSend()) inside a critical section and set the send
 * block time to 0.  Likewise, if there are to be multiple different readers
 * then the application writer must place each call to a reading API function
 * (such as xStreamBufferRead()) inside a critical section section and set the
 * receive block time to 0.
 *
 */

#ifndef STREAM_BUFFER_H
#define STREAM_BUFFER_H

#if defined( __cplusplus )
extern "C" {
#endif

typedef void * StreamBufferHandle_t;


#define xStreamBufferCreate( xBufferSizeBytes, xTriggerLevelBytes ) xStreamBufferGenericCreate( xBufferSizeBytes, xTriggerLevelBytes, pdFALSE )

#define xStreamBufferCreateStatic( xBufferSizeBytes, xTriggerLevelBytes, pucStreamBufferStorageArea, pxStaticStreamBuffer ) xStreamBufferGenericCreateStatic( xBufferSizeBytes, xTriggerLevelBytes, pdFALSE, pucStreamBufferStorageArea, pxStaticStreamBuffer )

size_t xStreamBufferSend( StreamBufferHandle_t xStreamBuffer,
                                                  const void *pvTxData,
                                                  size_t xDataLengthBytes,
                                                  TickType_t xTicksToWait ) PRIVILEGED_FUNCTION;

size_t xStreamBufferSendFromISR( StreamBufferHandle_t xStreamBuffer,
                                                                 const void *pvTxData,
                                                                 size_t xDataLengthBytes,
                                                                 BaseType_t * const pxHigherPriorityTaskWoken ) PRIVILEGED_FUNCTION;

size_t xStreamBufferReceive( StreamBufferHandle_t xStreamBuffer,
                                                         void *pvRxData,
                                                         size_t xBufferLengthBytes,
                                                         TickType_t xTicksToWait ) PRIVILEGED_FUNCTION;

size_t xStreamBufferReceiveFromISR( StreamBufferHandle_t xStreamBuffer,
                                                                        void *pvRxData,
                                                                        size_t xBufferLengthBytes,
                                                                        BaseType_t * const pxHigherPriorityTaskWoken ) PRIVILEGED_FUNCTION;

void vStreamBufferDelete( StreamBufferHandle_t xStreamBuffer ) PRIVILEGED_FUNCTION;

BaseType_t xStreamBufferIsFull( StreamBufferHandle_t xStreamBuffer ) PRIVILEGED_FUNCTION;

BaseType_t xStreamBufferIsEmpty( StreamBufferHandle_t xStreamBuffer ) PRIVILEGED_FUNCTION;

BaseType_t xStreamBufferReset( StreamBufferHandle_t xStreamBuffer ) PRIVILEGED_FUNCTION;

size_t xStreamBufferSpacesAvailable( StreamBufferHandle_t xStreamBuffer ) PRIVILEGED_FUNCTION;

size_t xStreamBufferBytesAvailable( StreamBufferHandle_t xStreamBuffer ) PRIVILEGED_FUNCTION;

BaseType_t xStreamBufferSetTriggerLevel( StreamBufferHandle_t xStreamBuffer, size_t xTriggerLevel ) PRIVILEGED_FUNCTION;

BaseType_t xStreamBufferSendCompletedFromISR( StreamBufferHandle_t xStreamBuffer, BaseType_t *pxHigherPriorityTaskWoken ) PRIVILEGED_FUNCTION;

BaseType_t xStreamBufferReceiveCompletedFromISR( StreamBufferHandle_t xStreamBuffer, BaseType_t *pxHigherPriorityTaskWoken ) PRIVILEGED_FUNCTION;

/* Functions below here are not part of the public API. */
StreamBufferHandle_t xStreamBufferGenericCreate( size_t xBufferSizeBytes,
                                                                                                 size_t xTriggerLevelBytes,
                                                                                                 BaseType_t xIsMessageBuffer ) PRIVILEGED_FUNCTION;

StreamBufferHandle_t xStreamBufferGenericCreateStatic( size_t xBufferSizeBytes,
                                                                                                           size_t xTriggerLevelBytes,
                                                                                                           BaseType_t xIsMessageBuffer,
                                                                                                           uint8_t * const pucStreamBufferStorageArea,
                                                                                                           StaticStreamBuffer_t * const pxStaticStreamBuffer ) PRIVILEGED_FUNCTION;

#if( configUSE_TRACE_FACILITY == 1 )
        void vStreamBufferSetStreamBufferNumber( StreamBufferHandle_t xStreamBuffer, UBaseType_t uxStreamBufferNumber ) PRIVILEGED_FUNCTION;
        UBaseType_t uxStreamBufferGetStreamBufferNumber( StreamBufferHandle_t xStreamBuffer ) PRIVILEGED_FUNCTION;
        uint8_t ucStreamBufferGetStreamBufferType( StreamBufferHandle_t xStreamBuffer ) PRIVILEGED_FUNCTION;
#endif

#if defined( __cplusplus )
}
#endif

#endif  /* !defined( STREAM_BUFFER_H ) */