mongoose/test/freertos-tcp/portable/BufferManagement/BufferAllocation_2.c
2021-05-13 22:05:00 +01:00

402 lines
15 KiB
C

/*
* FreeRTOS+TCP V2.3.2
* 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.
*
* http://www.FreeRTOS.org
* http://aws.amazon.com/freertos
*
* 1 tab == 4 spaces!
*/
/******************************************************************************
*
* See the following web page for essential buffer allocation scheme usage and
* configuration details:
* http://www.FreeRTOS.org/FreeRTOS-Plus/FreeRTOS_Plus_TCP/Embedded_Ethernet_Buffer_Management.html
*
******************************************************************************/
/* THIS FILE SHOULD NOT BE USED IF THE PROJECT INCLUDES A MEMORY ALLOCATOR
* THAT WILL FRAGMENT THE HEAP MEMORY. For example, heap_2 must not be used,
* heap_4 can be used. */
/* Standard includes. */
#include <stdint.h>
/* FreeRTOS includes. */
#include "FreeRTOS.h"
#include "task.h"
#include "semphr.h"
/* FreeRTOS+TCP includes. */
#include "FreeRTOS_IP.h"
#include "FreeRTOS_UDP_IP.h"
#include "FreeRTOS_IP_Private.h"
#include "NetworkInterface.h"
#include "NetworkBufferManagement.h"
/* The obtained network buffer must be large enough to hold a packet that might
* replace the packet that was requested to be sent. */
#if ipconfigUSE_TCP == 1
#define baMINIMAL_BUFFER_SIZE sizeof( TCPPacket_t )
#else
#define baMINIMAL_BUFFER_SIZE sizeof( ARPPacket_t )
#endif /* ipconfigUSE_TCP == 1 */
/*_RB_ This is too complex not to have an explanation. */
#if defined( ipconfigETHERNET_MINIMUM_PACKET_BYTES )
#define ASSERT_CONCAT_( a, b ) a ## b
#define ASSERT_CONCAT( a, b ) ASSERT_CONCAT_( a, b )
#define STATIC_ASSERT( e ) \
; enum { ASSERT_CONCAT( assert_line_, __LINE__ ) = 1 / ( !!( e ) ) }
STATIC_ASSERT( ipconfigETHERNET_MINIMUM_PACKET_BYTES <= baMINIMAL_BUFFER_SIZE );
#endif
/* A list of free (available) NetworkBufferDescriptor_t structures. */
static List_t xFreeBuffersList;
/* Some statistics about the use of buffers. */
static size_t uxMinimumFreeNetworkBuffers;
/* Declares the pool of NetworkBufferDescriptor_t structures that are available
* to the system. All the network buffers referenced from xFreeBuffersList exist
* in this array. The array is not accessed directly except during initialisation,
* when the xFreeBuffersList is filled (as all the buffers are free when the system
* is booted). */
static NetworkBufferDescriptor_t xNetworkBufferDescriptors[ ipconfigNUM_NETWORK_BUFFER_DESCRIPTORS ];
/* This constant is defined as false to let FreeRTOS_TCP_IP.c know that the
* network buffers have a variable size: resizing may be necessary */
const BaseType_t xBufferAllocFixedSize = pdFALSE;
/* The semaphore used to obtain network buffers. */
static SemaphoreHandle_t xNetworkBufferSemaphore = NULL;
/*-----------------------------------------------------------*/
BaseType_t xNetworkBuffersInitialise( void )
{
BaseType_t xReturn;
uint32_t x;
/* Only initialise the buffers and their associated kernel objects if they
* have not been initialised before. */
if( xNetworkBufferSemaphore == NULL )
{
xNetworkBufferSemaphore = xSemaphoreCreateCounting( ipconfigNUM_NETWORK_BUFFER_DESCRIPTORS, ipconfigNUM_NETWORK_BUFFER_DESCRIPTORS );
configASSERT( xNetworkBufferSemaphore != NULL );
if( xNetworkBufferSemaphore != NULL )
{
#if ( configQUEUE_REGISTRY_SIZE > 0 )
{
vQueueAddToRegistry( xNetworkBufferSemaphore, "NetBufSem" );
}
#endif /* configQUEUE_REGISTRY_SIZE */
/* If the trace recorder code is included name the semaphore for viewing
* in FreeRTOS+Trace. */
#if ( ipconfigINCLUDE_EXAMPLE_FREERTOS_PLUS_TRACE_CALLS == 1 )
{
extern QueueHandle_t xNetworkEventQueue;
vTraceSetQueueName( xNetworkEventQueue, "IPStackEvent" );
vTraceSetQueueName( xNetworkBufferSemaphore, "NetworkBufferCount" );
}
#endif /* ipconfigINCLUDE_EXAMPLE_FREERTOS_PLUS_TRACE_CALLS == 1 */
vListInitialise( &xFreeBuffersList );
/* Initialise all the network buffers. No storage is allocated to
* the buffers yet. */
for( x = 0U; x < ipconfigNUM_NETWORK_BUFFER_DESCRIPTORS; x++ )
{
/* Initialise and set the owner of the buffer list items. */
xNetworkBufferDescriptors[ x ].pucEthernetBuffer = NULL;
vListInitialiseItem( &( xNetworkBufferDescriptors[ x ].xBufferListItem ) );
listSET_LIST_ITEM_OWNER( &( xNetworkBufferDescriptors[ x ].xBufferListItem ), &xNetworkBufferDescriptors[ x ] );
/* Currently, all buffers are available for use. */
vListInsert( &xFreeBuffersList, &( xNetworkBufferDescriptors[ x ].xBufferListItem ) );
}
uxMinimumFreeNetworkBuffers = ipconfigNUM_NETWORK_BUFFER_DESCRIPTORS;
}
}
if( xNetworkBufferSemaphore == NULL )
{
xReturn = pdFAIL;
}
else
{
xReturn = pdPASS;
}
return xReturn;
}
/*-----------------------------------------------------------*/
uint8_t * pucGetNetworkBuffer( size_t * pxRequestedSizeBytes )
{
uint8_t * pucEthernetBuffer;
size_t xSize = *pxRequestedSizeBytes;
if( xSize < baMINIMAL_BUFFER_SIZE )
{
/* Buffers must be at least large enough to hold a TCP-packet with
* headers, or an ARP packet, in case TCP is not included. */
xSize = baMINIMAL_BUFFER_SIZE;
}
/* Round up xSize to the nearest multiple of N bytes,
* where N equals 'sizeof( size_t )'. */
if( ( xSize & ( sizeof( size_t ) - 1U ) ) != 0U )
{
xSize = ( xSize | ( sizeof( size_t ) - 1U ) ) + 1U;
}
*pxRequestedSizeBytes = xSize;
/* Allocate a buffer large enough to store the requested Ethernet frame size
* and a pointer to a network buffer structure (hence the addition of
* ipBUFFER_PADDING bytes). */
pucEthernetBuffer = ( uint8_t * ) pvPortMalloc( xSize + ipBUFFER_PADDING );
configASSERT( pucEthernetBuffer != NULL );
if( pucEthernetBuffer != NULL )
{
/* Enough space is left at the start of the buffer to place a pointer to
* the network buffer structure that references this Ethernet buffer.
* Return a pointer to the start of the Ethernet buffer itself. */
pucEthernetBuffer += ipBUFFER_PADDING;
}
return pucEthernetBuffer;
}
/*-----------------------------------------------------------*/
void vReleaseNetworkBuffer( uint8_t * pucEthernetBuffer )
{
/* There is space before the Ethernet buffer in which a pointer to the
* network buffer that references this Ethernet buffer is stored. Remove the
* space before freeing the buffer. */
if( pucEthernetBuffer != NULL )
{
pucEthernetBuffer -= ipBUFFER_PADDING;
vPortFree( ( void * ) pucEthernetBuffer );
}
}
/*-----------------------------------------------------------*/
NetworkBufferDescriptor_t * pxGetNetworkBufferWithDescriptor( size_t xRequestedSizeBytes,
TickType_t xBlockTimeTicks )
{
NetworkBufferDescriptor_t * pxReturn = NULL;
size_t uxCount;
if( xNetworkBufferSemaphore != NULL )
{
if( ( xRequestedSizeBytes != 0U ) && ( xRequestedSizeBytes < ( size_t ) baMINIMAL_BUFFER_SIZE ) )
{
/* ARP packets can replace application packets, so the storage must be
* at least large enough to hold an ARP. */
xRequestedSizeBytes = baMINIMAL_BUFFER_SIZE;
}
/* Add 2 bytes to xRequestedSizeBytes and round up xRequestedSizeBytes
* to the nearest multiple of N bytes, where N equals 'sizeof( size_t )'. */
xRequestedSizeBytes += 2U;
if( ( xRequestedSizeBytes & ( sizeof( size_t ) - 1U ) ) != 0U )
{
xRequestedSizeBytes = ( xRequestedSizeBytes | ( sizeof( size_t ) - 1U ) ) + 1U;
}
/* If there is a semaphore available, there is a network buffer available. */
if( xSemaphoreTake( xNetworkBufferSemaphore, xBlockTimeTicks ) == pdPASS )
{
/* Protect the structure as it is accessed from tasks and interrupts. */
taskENTER_CRITICAL();
{
pxReturn = ( NetworkBufferDescriptor_t * ) listGET_OWNER_OF_HEAD_ENTRY( &xFreeBuffersList );
( void ) uxListRemove( &( pxReturn->xBufferListItem ) );
}
taskEXIT_CRITICAL();
/* Reading UBaseType_t, no critical section needed. */
uxCount = listCURRENT_LIST_LENGTH( &xFreeBuffersList );
if( uxMinimumFreeNetworkBuffers > uxCount )
{
uxMinimumFreeNetworkBuffers = uxCount;
}
/* Allocate storage of exactly the requested size to the buffer. */
configASSERT( pxReturn->pucEthernetBuffer == NULL );
if( xRequestedSizeBytes > 0U )
{
/* Extra space is obtained so a pointer to the network buffer can
* be stored at the beginning of the buffer. */
pxReturn->pucEthernetBuffer = ( uint8_t * ) pvPortMalloc( xRequestedSizeBytes + ipBUFFER_PADDING );
if( pxReturn->pucEthernetBuffer == NULL )
{
/* The attempt to allocate storage for the buffer payload failed,
* so the network buffer structure cannot be used and must be
* released. */
vReleaseNetworkBufferAndDescriptor( pxReturn );
pxReturn = NULL;
}
else
{
/* Store a pointer to the network buffer structure in the
* buffer storage area, then move the buffer pointer on past the
* stored pointer so the pointer value is not overwritten by the
* application when the buffer is used. */
*( ( NetworkBufferDescriptor_t ** ) ( pxReturn->pucEthernetBuffer ) ) = pxReturn;
pxReturn->pucEthernetBuffer += ipBUFFER_PADDING;
/* Store the actual size of the allocated buffer, which may be
* greater than the original requested size. */
pxReturn->xDataLength = xRequestedSizeBytes;
#if ( ipconfigUSE_LINKED_RX_MESSAGES != 0 )
{
/* make sure the buffer is not linked */
pxReturn->pxNextBuffer = NULL;
}
#endif /* ipconfigUSE_LINKED_RX_MESSAGES */
}
}
else
{
/* A descriptor is being returned without an associated buffer being
* allocated. */
}
}
}
if( pxReturn == NULL )
{
iptraceFAILED_TO_OBTAIN_NETWORK_BUFFER();
}
else
{
/* No action. */
iptraceNETWORK_BUFFER_OBTAINED( pxReturn );
}
return pxReturn;
}
/*-----------------------------------------------------------*/
void vReleaseNetworkBufferAndDescriptor( NetworkBufferDescriptor_t * const pxNetworkBuffer )
{
BaseType_t xListItemAlreadyInFreeList;
/* Ensure the buffer is returned to the list of free buffers before the
* counting semaphore is 'given' to say a buffer is available. Release the
* storage allocated to the buffer payload. THIS FILE SHOULD NOT BE USED
* IF THE PROJECT INCLUDES A MEMORY ALLOCATOR THAT WILL FRAGMENT THE HEAP
* MEMORY. For example, heap_2 must not be used, heap_4 can be used. */
vReleaseNetworkBuffer( pxNetworkBuffer->pucEthernetBuffer );
pxNetworkBuffer->pucEthernetBuffer = NULL;
taskENTER_CRITICAL();
{
xListItemAlreadyInFreeList = listIS_CONTAINED_WITHIN( &xFreeBuffersList, &( pxNetworkBuffer->xBufferListItem ) );
if( xListItemAlreadyInFreeList == pdFALSE )
{
vListInsertEnd( &xFreeBuffersList, &( pxNetworkBuffer->xBufferListItem ) );
}
}
taskEXIT_CRITICAL();
/*
* Update the network state machine, unless the program fails to release its 'xNetworkBufferSemaphore'.
* The program should only try to release its semaphore if 'xListItemAlreadyInFreeList' is false.
*/
if( xListItemAlreadyInFreeList == pdFALSE )
{
if( xSemaphoreGive( xNetworkBufferSemaphore ) == pdTRUE )
{
iptraceNETWORK_BUFFER_RELEASED( pxNetworkBuffer );
}
}
else
{
/* No action. */
iptraceNETWORK_BUFFER_RELEASED( pxNetworkBuffer );
}
}
/*-----------------------------------------------------------*/
/*
* Returns the number of free network buffers
*/
UBaseType_t uxGetNumberOfFreeNetworkBuffers( void )
{
return listCURRENT_LIST_LENGTH( &xFreeBuffersList );
}
/*-----------------------------------------------------------*/
UBaseType_t uxGetMinimumFreeNetworkBuffers( void )
{
return uxMinimumFreeNetworkBuffers;
}
/*-----------------------------------------------------------*/
NetworkBufferDescriptor_t * pxResizeNetworkBufferWithDescriptor( NetworkBufferDescriptor_t * pxNetworkBuffer,
size_t xNewSizeBytes )
{
size_t xOriginalLength;
uint8_t * pucBuffer;
xOriginalLength = pxNetworkBuffer->xDataLength + ipBUFFER_PADDING;
xNewSizeBytes = xNewSizeBytes + ipBUFFER_PADDING;
pucBuffer = pucGetNetworkBuffer( &( xNewSizeBytes ) );
if( pucBuffer == NULL )
{
/* In case the allocation fails, return NULL. */
pxNetworkBuffer = NULL;
}
else
{
pxNetworkBuffer->xDataLength = xNewSizeBytes;
if( xNewSizeBytes > xOriginalLength )
{
xNewSizeBytes = xOriginalLength;
}
( void ) memcpy( pucBuffer - ipBUFFER_PADDING, pxNetworkBuffer->pucEthernetBuffer - ipBUFFER_PADDING, xNewSizeBytes );
vReleaseNetworkBuffer( pxNetworkBuffer->pucEthernetBuffer );
pxNetworkBuffer->pucEthernetBuffer = pucBuffer;
}
return pxNetworkBuffer;
}