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Add ringbuf.c. This works like a FreeRTOS queue, but allows for variable-length items which in some cases is more memory efficient than a queue.

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Jeroen Domburg 2016-09-28 12:43:35 +08:00
parent b77bf9bc90
commit a9502dffd3
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206
components/freertos/include/freertos/ringbuf.h Normal file
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#ifndef FREERTOS_RINGBUF_H
#define FREERTOS_RINGBUF_H
/*
Header definitions for a FreeRTOS ringbuffer object
A ringbuffer instantiated by these functions essentially acts like a FreeRTOS queue, with the
difference that it's strictly FIFO and with the main advantage that you can put in randomly-sized
items. The capacity, accordingly, isn't measured in the amount of items, but the amount of memory
that is used for storing the items. Dependent on the size of the items, more or less of them will
fit in the ring buffer.
This ringbuffer tries to be efficient with memory: when inserting an item, the item data will
be copied to the ringbuffer memory. When retrieving an item, however, a reference to ringbuffer
memory will be returned. The returned memory is guaranteed to be 32-bit aligned and contiguous.
The application can use this memory, but as long as it does, ringbuffer writes that would write
to this bit of memory will block.
The requirement for items to be contiguous is slightly problematic when the only way to place
the next item would involve a wraparound from the end to the beginning of the ringbuffer. This can
be solved in two ways:
- allow_split_items = pdTRUE: The insertion code will split the item in two items; one which fits
in the space left at the end of the ringbuffer, one that contains the remaining data which is placed
in the beginning. Two xRingbufferReceive calls will be needed to retrieve the data.
- allow_split_items = pdFALSE: The insertion code will leave the room at the end of the ringbuffer
unused and instead will put the entire item at the start of the ringbuffer, as soon as there is
enough free space.
The maximum size of an item will be affected by this decision. When split items are allowed, it's
acceptable to push items of (buffer_size)-16 bytes into the buffer. When it's not allowed, the
maximum size is (buffer_size/2)-8 bytes.
*/
//An opaque handle for a ringbuff object.
typedef void * RingbufHandle_t;
/**
* @brief Create a ring buffer
*
* @param buf_length : Length of circular buffer, in bytes. Each entry will take up its own length, plus a header
* that at the moment is equal to sizeof(size_t).
* @param allow_split_items : pdTRUE if it is acceptable that item data is inserted as two
* items instead of one.
*
* @return A RingbufHandle_t handle to the created ringbuffer, or NULL in case of error.
*/
RingbufHandle_t xRingbufferCreate(size_t buf_length, BaseType_t allow_split_items);
/**
* @brief Delete a ring buffer
*
* @param ringbuf - Ring buffer to delete
*
* @return void
*/
void vRingbufferDelete(RingbufHandle_t ringbuf);
/**
* @brief Get maximum size of an item that can be placed in the ring buffer
*
* @param ringbuf - Ring buffer to query
*
* @return Maximum size, in bytes, of an item that can be placed in a ring buffer.
*/
size_t xRingbufferGetMaxItemSize(RingbufHandle_t ringbuf);
/**
* @brief Insert an item into the ring buffer
*
* @param ringbuf - Ring buffer to insert the item into
* @param data - Pointer to data to insert. NULL is allowed if data_size is 0.
* @param data_size - Size of data to insert. A value of 0 is allowed.
* @param xTicksToWait - Ticks to wait for room in the ringbuffer.
*
* @return pdTRUE if succeeded, pdFALSE on time-out or when the buffer is larger
* than indicated by xRingbufferGetMaxItemSize(ringbuf).
*/
BaseType_t xRingbufferSend(RingbufHandle_t ringbuf, void *data, size_t data_size, TickType_t ticks_to_wait);
/**
* @brief Insert an item into the ring buffer from an ISR
*
* @param ringbuf - Ring buffer to insert the item into
* @param data - Pointer to data to insert. NULL is allowed if data_size is 0.
* @param data_size - Size of data to insert. A value of 0 is allowed.
* @param higher_prio_task_awoken - Value pointed to will be set to pdTRUE if the push woke up a higher
* priority task.
*
* @return pdTRUE if succeeded, pdFALSE when the ring buffer does not have space.
*/
BaseType_t xRingbufferSendFromISR(RingbufHandle_t ringbuf, void *data, size_t data_size, BaseType_t *higher_prio_task_awoken);
/**
* @brief Retrieve an item from the ring buffer
*
* @param ringbuf - Ring buffer to retrieve the item from
* @param item_size - Pointer to a variable to which the size of the retrieved item will be written.
* @param xTicksToWait - Ticks to wait for items in the ringbuffer.
*
* @return Pointer to the retrieved item on success; *item_size filled with the length of the
* item. NULL on timeout, *item_size is untouched in that case.
*/
void *xRingbufferReceive(RingbufHandle_t ringbuf, size_t *item_size, TickType_t ticks_to_wait);
/**
* @brief Retrieve an item from the ring buffer from an ISR
*
* @param ringbuf - Ring buffer to retrieve the item from
* @param item_size - Pointer to a variable to which the size of the retrieved item will be written.
*
* @return Pointer to the retrieved item on success; *item_size filled with the length of the
* item. NULL when the ringbuffer is empty, *item_size is untouched in that case.
*/
void *xRingbufferReceiveFromISR(RingbufHandle_t ringbuf, size_t *item_size);
/**
* @brief Return a previously-retrieved item to the ringbuffer
*
* @param ringbuf - Ring buffer the item was retrieved from
* @param item - Item that was received earlier
*
* @return void
*/
void vRingbufferReturnItem(RingbufHandle_t ringbuf, void *item);
/**
* @brief Return a previously-retrieved item to the ringbuffer from an ISR
*
* @param ringbuf - Ring buffer the item was retrieved from
* @param item - Item that was received earlier
* @param higher_prio_task_awoken - Value pointed to will be set to pdTRUE if the push woke up a higher
* priority task.
*
* @return void
*/
void vRingbufferReturnItemFromISR(RingbufHandle_t ringbuf, void *item, BaseType_t *higher_prio_task_awoken);
/**
* @brief Add the ringbuffer to a queue set. This specifically adds the semaphore that indicates
* more space has become available in the ringbuffer.
*
* @param ringbuf - Ring buffer to add to the queue set
* @param xQueueSet - Queue set to add the ringbuffer to
*
* @return pdTRUE on success, pdFALSE otherwise
*/
BaseType_t xRingbufferAddToQueueSetRead(RingbufHandle_t ringbuf, QueueSetHandle_t xQueueSet);
/**
* @brief Add the ringbuffer to a queue set. This specifically adds the semaphore that indicates
* something has been written into the ringbuffer.
*
* @param ringbuf - Ring buffer to add to the queue set
* @param xQueueSet - Queue set to add the ringbuffer to
*
* @return pdTRUE on success, pdFALSE otherwise
*/
BaseType_t xRingbufferAddToQueueSetWrite(RingbufHandle_t ringbuf, QueueSetHandle_t xQueueSet);
/**
* @brief Remove the ringbuffer from a queue set. This specifically removes the semaphore that indicates
* more space has become available in the ringbuffer.
*
* @param ringbuf - Ring buffer to remove from the queue set
* @param xQueueSet - Queue set to remove the ringbuffer from
*
* @return pdTRUE on success, pdFALSE otherwise
*/
BaseType_t xRingbufferRemoveFromQueueSetRead(RingbufHandle_t ringbuf, QueueSetHandle_t xQueueSet);
/**
* @brief Remove the ringbuffer from a queue set. This specifically removes the semaphore that indicates
* something has been written to the ringbuffer.
*
* @param ringbuf - Ring buffer to remove from the queue set
* @param xQueueSet - Queue set to remove the ringbuffer from
*
* @return pdTRUE on success, pdFALSE otherwise
*/
BaseType_t xRingbufferRemoveFromQueueSetWrite(RingbufHandle_t ringbuf, QueueSetHandle_t xQueueSet);
/**
* @brief Debugging function to print the internal pointers in the ring buffer
*
* @param ringbuf - Ring buffer to show
*
* @return void
*/
void xRingbufferPrintInfo(RingbufHandle_t ringbuf);
#endif

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// Copyright 2015-2016 Espressif Systems (Shanghai) PTE LTD
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include "freertos/semphr.h"
#include "freertos/queue.h"
#include "freertos/xtensa_api.h"
#include "freertos/ringbuf.h"
#include <stdint.h>
#include <string.h>
#include <stdlib.h>
#include <stdio.h>
typedef enum {
flag_allowsplit = 1,
} rbflag_t;
typedef enum {
iflag_free = 1, //Buffer is not read and given back by application, free to overwrite
iflag_dummydata = 2, //Data from here to end of ringbuffer is dummy. Restart reading at start of ringbuffer.
} itemflag_t;
//The ringbuffer structure
typedef struct {
SemaphoreHandle_t free_space_sem; //Binary semaphore, wakes up writing threads when there's more free space
SemaphoreHandle_t items_buffered_sem; //Binary semaphore, indicates there are new packets in the circular buffer. See remark.
size_t size; //Size of the data storage
uint8_t *write_ptr; //Pointer where the next item is written
uint8_t *read_ptr; //Pointer from where the next item is read
uint8_t *free_ptr; //Pointer to the last block that hasn't been given back to the ringbuffer yet
uint8_t *data; //Data storage
portMUX_TYPE mux; //Spinlock for actual data/ptr/struct modification
rbflag_t flags;
} ringbuf_t;
/*
Remark: A counting semaphore for items_buffered_sem would be more logical, but counting semaphores in
FreeRTOS need a maximum count, and allocate more memory the larger the maximum count is. Here, we
would need to set the maximum to the maximum amount of times a null-byte unit firs in the buffer,
which is quite high and so would waste a fair amount of memory.
*/
//The header prepended to each ringbuffer entry. Size is assumed to be a multiple of 32bits.
typedef struct {
size_t len;
itemflag_t flags;
} buf_entry_hdr_t;
//Calculate space free in the buffer
static int ringbufferFreeMem(ringbuf_t *rb)
{
int free_size = rb->free_ptr-rb->write_ptr;
if (free_size <= 0) free_size += rb->size;
//Reserve one byte. If we do not do this and the entire buffer is filled, we get a situation
//where read_ptr == free_ptr, messing up the next calculation.
return free_size-1;
}
//Copies a single item to the ring buffer. Assumes there is space in the ringbuffer and
//the ringbuffer is locked. Increases write_ptr to the next item. Returns pdTRUE on
//success, pdFALSE if it can't make the item fit and the calling routine needs to retry
//later or fail.
//This function by itself is not threadsafe, always call from within a muxed section.
static BaseType_t copyItemToRingbuf(ringbuf_t *rb, uint8_t *buffer, size_t buffer_size)
{
size_t rbuffer_size=(buffer_size+3)&~3; //Payload length, rounded to next 32-bit value
configASSERT(((int)rb->write_ptr&3)==0); //write_ptr needs to be 32-bit aligned
configASSERT(rb->write_ptr-(rb->data+rb->size) >= sizeof(buf_entry_hdr_t)); //need to have at least the size
//of a header to the end of the ringbuff
size_t rem_len=(rb->data + rb->size) - rb->write_ptr; //length remaining until end of ringbuffer
//See if we have enough contiguous space to write the buffer.
if (rem_len < rbuffer_size + sizeof(buf_entry_hdr_t)) {
//The buffer can't be contiguously written to the ringbuffer, but needs special handling. Do
//that depending on how the ringbuffer is configured.
//The code here is also expected to check if the buffer, mangled in whatever way is implemented,
//will still fit, and return pdFALSE if that is not the case.
if (rb->flags & flag_allowsplit) {
//Buffer plus header is not going to fit in the room from wr_pos to the end of the
//ringbuffer... we need to split the write in two.
//First, see if this will fit at all.
if (ringbufferFreeMem(rb) < (sizeof(buf_entry_hdr_t)*2)+rbuffer_size) {
//Will not fit.
return pdFALSE;
}
//Because the code at the end of the function makes sure we always have
//room for a header, this should never assert.
configASSERT(rem_len>=sizeof(buf_entry_hdr_t));
//Okay, it should fit. Write everything.
//First, place bit of buffer that does fit. Write header first...
buf_entry_hdr_t *hdr=(buf_entry_hdr_t *)rb->write_ptr;
hdr->flags=0;
hdr->len=rem_len-sizeof(buf_entry_hdr_t);
rb->write_ptr+=sizeof(buf_entry_hdr_t);
rem_len-=sizeof(buf_entry_hdr_t);
if (rem_len!=0) {
//..then write the data bit that fits.
memcpy(rb->write_ptr, buffer, rem_len);
//Update vars so the code later on will write the rest of the data.
buffer+=rem_len;
rbuffer_size-=rem_len;
buffer_size-=rem_len;
} else {
//Huh, only the header fit. Mark as dummy so the receive function doesn't receive
//an useless zero-byte packet.
hdr->flags|=iflag_dummydata;
}
rb->write_ptr=rb->data;
} else {
//Buffer plus header is not going to fit in the room from wr_pos to the end of the
//ringbuffer... but we're not allowed to split the buffer. We need to fill the
//rest of the ringbuffer with a dummy item so we can place the data at the _start_ of
//the ringbuffer..
//First, find out if we actually have enough space at the start of the ringbuffer to
//make this work (Again, we need 4 bytes extra because otherwise read_ptr==free_ptr)
if (rb->free_ptr-rb->data < rbuffer_size+sizeof(buf_entry_hdr_t)+4) {
//Will not fit.
return pdFALSE;
}
//If the read buffer hasn't wrapped around yet, there's no way this will work either.
if (rb->free_ptr > rb->write_ptr) {
//No luck.
return pdFALSE;
}
//Okay, it will fit. Mark the rest of the ringbuffer space with a dummy packet.
buf_entry_hdr_t *hdr=(buf_entry_hdr_t *)rb->write_ptr;
hdr->flags=iflag_dummydata;
//Reset the write pointer to the start of the ringbuffer so the code later on can
//happily write the data.
rb->write_ptr=rb->data;
}
} else {
//No special handling needed. Checking if it's gonna fit probably still is a good idea.
if (ringbufferFreeMem(rb) < sizeof(buf_entry_hdr_t)+rbuffer_size) {
//Buffer is not going to fit, period.
return pdFALSE;
}
}
//If we are here, the buffer is guaranteed to fit in the space starting at the write pointer.
buf_entry_hdr_t *hdr=(buf_entry_hdr_t *)rb->write_ptr;
hdr->len=buffer_size;
hdr->flags=0;
rb->write_ptr+=sizeof(buf_entry_hdr_t);
memcpy(rb->write_ptr, buffer, buffer_size);
rb->write_ptr+=rbuffer_size;
//The buffer will wrap around if we don't have room for a header anymore.
if ((rb->data+rb->size)-rb->write_ptr < sizeof(buf_entry_hdr_t)) {
//'Forward' the write buffer until we are at the start of the ringbuffer.
//The read pointer will always be at the start of a full header, which cannot
//exist at the point of the current write pointer, so there's no chance of overtaking
//that.
rb->write_ptr=rb->data;
}
return pdTRUE;
}
//Retrieves a pointer to the data of the next item, or NULL if this is not possible.
//This function by itself is not threadsafe, always call from within a muxed section.
static uint8_t *getItemFromRingbuf(ringbuf_t *rb, size_t *length)
{
uint8_t *ret;
configASSERT(((int)rb->read_ptr&3)==0);
if (rb->read_ptr == rb->write_ptr) {
//No data available.
return NULL;
}
//The item written at the point of the read pointer may be a dummy item.
//We need to skip past it first, if that's the case.
buf_entry_hdr_t *hdr=(buf_entry_hdr_t *)rb->read_ptr;
configASSERT((hdr->len < rb->size) || (hdr->flags & iflag_dummydata));
if (hdr->flags & iflag_dummydata) {
//Hdr is dummy data. Reset to start of ringbuffer.
rb->read_ptr=rb->data;
//Get real header
hdr=(buf_entry_hdr_t *)rb->read_ptr;
configASSERT(hdr->len < rb->size);
//No need to re-check if the ringbuffer is empty: the write routine will
//always write a dummy item plus the real data item in one go, so now we must
//be at the real data item by definition.
}
//Okay, pass the data back.
ret=rb->read_ptr+sizeof(buf_entry_hdr_t);
*length=hdr->len;
//...and move the read pointer past the data.
rb->read_ptr+=sizeof(buf_entry_hdr_t)+((hdr->len+3)&~3);
//The buffer will wrap around if we don't have room for a header anymore.
if ((rb->data + rb->size) - rb->read_ptr < sizeof(buf_entry_hdr_t)) {
rb->read_ptr=rb->data;
}
return ret;
}
//Returns an item to the ringbuffer. Will mark the item as free, and will see if the free pointer
//can be increase.
//This function by itself is not threadsafe, always call from within a muxed section.
static void returnItemToRingbuf(ringbuf_t *rb, void *item) {
uint8_t *data=(uint8_t*)item;
configASSERT(((int)rb->free_ptr&3)==0);
configASSERT(data >= rb->data);
configASSERT(data < rb->data+rb->size);
//Grab the buffer entry that preceeds the buffer
buf_entry_hdr_t *hdr=(buf_entry_hdr_t*)(data-sizeof(buf_entry_hdr_t));
configASSERT(hdr->len < rb->size);
configASSERT((hdr->flags & iflag_dummydata)==0);
configASSERT((hdr->flags & iflag_free)==0);
//Mark the buffer as free.
hdr->flags|=iflag_free;
//Do a cleanup pass.
hdr=(buf_entry_hdr_t *)rb->free_ptr;
//basically forward free_ptr until we run into either a block that is still in use or the write pointer.
while (((hdr->flags & iflag_free) || (hdr->flags & iflag_dummydata)) && rb->free_ptr != rb->write_ptr) {
if (hdr->flags & iflag_dummydata) {
//Rest is dummy data. Reset to start of ringbuffer.
rb->free_ptr=rb->data;
} else {
//Skip past item
size_t len=(hdr->len+3)&~3;
rb->free_ptr+=len+sizeof(buf_entry_hdr_t);
configASSERT(rb->free_ptr<=rb->data+rb->size);
}
//The buffer will wrap around if we don't have room for a header anymore.
if ((rb->data+rb->size)-rb->free_ptr < sizeof(buf_entry_hdr_t)) {
rb->free_ptr=rb->data;
}
//Next header
hdr=(buf_entry_hdr_t *)rb->free_ptr;
}
}
void xRingbufferPrintInfo(RingbufHandle_t ringbuf)
{
ringbuf_t *rb=(ringbuf_t *)ringbuf;
configASSERT(rb);
ets_printf("Rb size %d free %d rptr %d freeptr %d wptr %d\n",
rb->size, ringbufferFreeMem(rb), rb->read_ptr-rb->data, rb->free_ptr-rb->data, rb->write_ptr-rb->data);
}
RingbufHandle_t xRingbufferCreate(size_t buf_length, BaseType_t allow_split_items)
{
ringbuf_t *rb = malloc(sizeof(ringbuf_t));
if (rb==NULL) goto err;
memset(rb, 0, sizeof(ringbuf_t));
rb->data = malloc(buf_length);
if (rb->data == NULL) goto err;
rb->size = buf_length;
rb->free_ptr = rb->data;
rb->read_ptr = rb->data;
rb->write_ptr = rb->data;
rb->free_space_sem = xSemaphoreCreateBinary();
rb->items_buffered_sem = xSemaphoreCreateBinary();
rb->flags=0;
if (allow_split_items) rb->flags|=flag_allowsplit;
if (rb->free_space_sem == NULL || rb->items_buffered_sem == NULL) goto err;
vPortCPUInitializeMutex(&rb->mux);
return (RingbufHandle_t)rb;
err:
//Some error has happened. Free/destroy all allocated things and return NULL.
if (rb) {
free(rb->data);
if (rb->free_space_sem) vSemaphoreDelete(rb->free_space_sem);
if (rb->items_buffered_sem) vSemaphoreDelete(rb->items_buffered_sem);
}
free(rb);
return NULL;
}
void vRingbufferDelete(RingbufHandle_t ringbuf) {
ringbuf_t *rb=(ringbuf_t *)ringbuf;
if (rb) {
free(rb->data);
if (rb->free_space_sem) vSemaphoreDelete(rb->free_space_sem);
if (rb->items_buffered_sem) vSemaphoreDelete(rb->items_buffered_sem);
}
free(rb);
}
size_t xRingbufferGetMaxItemSize(RingbufHandle_t ringbuf)
{
ringbuf_t *rb=(ringbuf_t *)ringbuf;
configASSERT(rb);
//In both cases, we return 4 bytes less than what we actually can have. If the ringbuffer is
//indeed entirely filled, read_ptr==free_ptr, which throws off the free space calculation.
if (rb->flags & flag_allowsplit) {
//Worst case, we need to split an item into two, which means two headers of overhead.
return rb->size-(sizeof(buf_entry_hdr_t)*2)-4;
} else {
//Worst case, we have the write ptr in such a position that we are lacking four bytes of free
//memory to put an item into the rest of the memory. If this happens, we have to dummy-fill
//(item_data-4) bytes of buffer, then we only have (size-(item_data-4) bytes left to fill
//with the real item. (item size being header+data)
return (rb->size/2)-sizeof(buf_entry_hdr_t)-4;
}
}
BaseType_t xRingbufferSend(RingbufHandle_t ringbuf, void *data, size_t dataSize, TickType_t ticks_to_wait)
{
ringbuf_t *rb=(ringbuf_t *)ringbuf;
size_t needed_size=dataSize+sizeof(buf_entry_hdr_t);
BaseType_t done=pdFALSE;
portTickType ticks_end=xTaskGetTickCount() + ticks_to_wait;
configASSERT(rb);
if (dataSize > xRingbufferGetMaxItemSize(ringbuf)) {
//Data will never ever fit in the queue.
return pdFALSE;
}
while (!done) {
//Check if there is enough room in the buffer. If not, wait until there is.
do {
if (ringbufferFreeMem(rb) < needed_size) {
//Data does not fit yet. Wait until the free_space_sem is given, then re-evaluate.
BaseType_t r = xSemaphoreTake(rb->free_space_sem, ticks_to_wait);
if (r == pdFALSE) {
//Timeout.
return pdFALSE;
}
//Adjust ticks_to_wait; we may have waited less than that and in the case the free memory still is not enough,
//we will need to wait some more.
ticks_to_wait = ticks_end - xTaskGetTickCount();
}
} while (ringbufferFreeMem(rb) < needed_size && ticks_to_wait>=0);
//Lock the mux in order to make sure no one else is messing with the ringbuffer and do the copy.
portENTER_CRITICAL(&rb->mux);
//Another thread may have been able to sneak its write first. Check again now we locked the ringbuff, and retry
//everything if this is the case. Otherwise, we can write and are done.
done=copyItemToRingbuf(rb, data, dataSize);
portEXIT_CRITICAL(&rb->mux);
}
xSemaphoreGive(rb->items_buffered_sem);
return pdTRUE;
}
BaseType_t xRingbufferSendFromISR(RingbufHandle_t ringbuf, void *data, size_t dataSize, BaseType_t *higher_prio_task_awoken)
{
ringbuf_t *rb=(ringbuf_t *)ringbuf;
BaseType_t write_succeeded;
configASSERT(rb);
size_t needed_size=dataSize+sizeof(buf_entry_hdr_t);
portENTER_CRITICAL_ISR(&rb->mux);
if (needed_size>ringbufferFreeMem(rb)) {
//Does not fit in the remaining space in the ringbuffer.
write_succeeded=pdFALSE;
} else {
copyItemToRingbuf(rb, data, dataSize);
write_succeeded=pdTRUE;
}
portEXIT_CRITICAL_ISR(&rb->mux);
if (write_succeeded) {
xSemaphoreGiveFromISR(rb->items_buffered_sem, higher_prio_task_awoken);
}
return write_succeeded;
}
void *xRingbufferReceive(RingbufHandle_t ringbuf, size_t *item_size, TickType_t ticks_to_wait)
{
ringbuf_t *rb=(ringbuf_t *)ringbuf;
uint8_t *itemData;
BaseType_t done=pdFALSE;
configASSERT(rb);
while(!done) {
//See if there's any data available. If not, wait until there is.
while (rb->read_ptr == rb->write_ptr) {
BaseType_t r=xSemaphoreTake(rb->items_buffered_sem, ticks_to_wait);
if (r == pdFALSE) {
//Timeout.
return NULL;
}
}
//Okay, we seem to have data in the buffer. Grab the mux and copy it out if it's still there.
portENTER_CRITICAL(&rb->mux);
itemData=getItemFromRingbuf(rb, item_size);
portEXIT_CRITICAL(&rb->mux);
if (itemData) {
//We managed to get an item.
done=pdTRUE;
}
}
return (void*)itemData;
}
void *xRingbufferReceiveFromISR(RingbufHandle_t ringbuf, size_t *item_size)
{
ringbuf_t *rb=(ringbuf_t *)ringbuf;
uint8_t *itemData;
configASSERT(rb);
portENTER_CRITICAL_ISR(&rb->mux);
itemData=getItemFromRingbuf(rb, item_size);
portEXIT_CRITICAL_ISR(&rb->mux);
return (void*)itemData;
}
void vRingbufferReturnItem(RingbufHandle_t ringbuf, void *item)
{
ringbuf_t *rb=(ringbuf_t *)ringbuf;
portENTER_CRITICAL_ISR(&rb->mux);
returnItemToRingbuf(rb, item);
portEXIT_CRITICAL_ISR(&rb->mux);
xSemaphoreGive(rb->free_space_sem);
}
void vRingbufferReturnItemFromISR(RingbufHandle_t ringbuf, void *item, BaseType_t *higher_prio_task_awoken)
{
ringbuf_t *rb=(ringbuf_t *)ringbuf;
portENTER_CRITICAL_ISR(&rb->mux);
returnItemToRingbuf(rb, item);
portEXIT_CRITICAL_ISR(&rb->mux);
xSemaphoreGiveFromISR(rb->free_space_sem, higher_prio_task_awoken);
}
BaseType_t xRingbufferAddToQueueSetRead(RingbufHandle_t ringbuf, QueueSetHandle_t xQueueSet)
{
ringbuf_t *rb=(ringbuf_t *)ringbuf;
configASSERT(rb);
return xQueueAddToSet(rb->items_buffered_sem, xQueueSet);
}
BaseType_t xRingbufferAddToQueueSetWrite(RingbufHandle_t ringbuf, QueueSetHandle_t xQueueSet)
{
ringbuf_t *rb=(ringbuf_t *)ringbuf;
configASSERT(rb);
return xQueueAddToSet(rb->free_space_sem, xQueueSet);
}
BaseType_t xRingbufferRemoveFromQueueSetRead(RingbufHandle_t ringbuf, QueueSetHandle_t xQueueSet)
{
ringbuf_t *rb=(ringbuf_t *)ringbuf;
configASSERT(rb);
return xQueueRemoveFromSet(rb->items_buffered_sem, xQueueSet);
}
BaseType_t xRingbufferRemoveFromQueueSetWrite(RingbufHandle_t ringbuf, QueueSetHandle_t xQueueSet)
{
ringbuf_t *rb=(ringbuf_t *)ringbuf;
configASSERT(rb);
return xQueueRemoveFromSet(rb->free_space_sem, xQueueSet);
}