--- /dev/null
+#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
--- /dev/null
+// 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);
+}
+