diff options
Diffstat (limited to 'src/drivers/device/ringbuffer.h')
| -rw-r--r-- | src/drivers/device/ringbuffer.h | 428 |
1 files changed, 367 insertions, 61 deletions
diff --git a/src/drivers/device/ringbuffer.h b/src/drivers/device/ringbuffer.h index dc0c84052..a9e22eaa6 100644 --- a/src/drivers/device/ringbuffer.h +++ b/src/drivers/device/ringbuffer.h @@ -1,7 +1,6 @@ /**************************************************************************** * * Copyright (C) 2013 PX4 Development Team. All rights reserved. - * Author: Lorenz Meier <lm@inf.ethz.ch> * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions @@ -35,15 +34,14 @@ /** * @file ringbuffer.h * - * A simple ringbuffer template. + * A flexible ringbuffer class. */ #pragma once -template<typename T> class RingBuffer { public: - RingBuffer(unsigned size); + RingBuffer(unsigned ring_size, size_t entry_size); virtual ~RingBuffer(); /** @@ -52,15 +50,37 @@ public: * @param val Item to put * @return true if the item was put, false if the buffer is full */ - bool put(T &val); + bool put(const void *val, size_t val_size = 0); + + bool put(int8_t val); + bool put(uint8_t val); + bool put(int16_t val); + bool put(uint16_t val); + bool put(int32_t val); + bool put(uint32_t val); + bool put(int64_t val); + bool put(uint64_t val); + bool put(float val); + bool put(double val); /** - * Put an item into the buffer. + * Force an item into the buffer, discarding an older item if there is not space. * * @param val Item to put - * @return true if the item was put, false if the buffer is full + * @return true if an item was discarded to make space */ - bool put(const T &val); + bool force(const void *val, size_t val_size = 0); + + bool force(int8_t val); + bool force(uint8_t val); + bool force(int16_t val); + bool force(uint16_t val); + bool force(int32_t val); + bool force(uint32_t val); + bool force(int64_t val); + bool force(uint64_t val); + bool force(float val); + bool force(double val); /** * Get an item from the buffer. @@ -68,15 +88,18 @@ public: * @param val Item that was gotten * @return true if an item was got, false if the buffer was empty. */ - bool get(T &val); + bool get(void *val, size_t val_size = 0); - /** - * Get an item from the buffer (scalars only). - * - * @return The value that was fetched, or zero if the buffer was - * empty. - */ - T get(void); + bool get(int8_t &val); + bool get(uint8_t &val); + bool get(int16_t &val); + bool get(uint16_t &val); + bool get(int32_t &val); + bool get(uint32_t &val); + bool get(int64_t &val); + bool get(uint64_t &val); + bool get(float &val); + bool get(double &val); /* * Get the number of slots free in the buffer. @@ -97,54 +120,103 @@ public: /* * Returns true if the buffer is empty. */ - bool empty() { return _tail == _head; } + bool empty(); /* * Returns true if the buffer is full. */ - bool full() { return _next(_head) == _tail; } + bool full(); /* * Returns the capacity of the buffer, or zero if the buffer could * not be allocated. */ - unsigned size() { return (_buf != nullptr) ? _size : 0; } + unsigned size(); /* * Empties the buffer. */ - void flush() { _head = _tail = _size; } + void flush(); + + /* + * resize the buffer. This is unsafe to be called while + * a producer or consuming is running. Caller is responsible + * for any locking needed + * + * @param new_size new size for buffer + * @return true if the resize succeeds, false if + * not (allocation error) + */ + bool resize(unsigned new_size); + + /* + * printf() some info on the buffer + */ + void print_info(const char *name); private: - T *const _buf; - const unsigned _size; - volatile unsigned _head; /**< insertion point */ - volatile unsigned _tail; /**< removal point */ + unsigned _num_items; + const size_t _item_size; + char *_buf; + volatile unsigned _head; /**< insertion point in _item_size units */ + volatile unsigned _tail; /**< removal point in _item_size units */ unsigned _next(unsigned index); }; -template <typename T> -RingBuffer<T>::RingBuffer(unsigned with_size) : - _buf(new T[with_size + 1]), - _size(with_size), - _head(with_size), - _tail(with_size) +RingBuffer::RingBuffer(unsigned num_items, size_t item_size) : + _num_items(num_items), + _item_size(item_size), + _buf(new char[(_num_items+1) * item_size]), + _head(_num_items), + _tail(_num_items) {} -template <typename T> -RingBuffer<T>::~RingBuffer() +RingBuffer::~RingBuffer() { if (_buf != nullptr) delete[] _buf; } -template <typename T> -bool RingBuffer<T>::put(T &val) +unsigned +RingBuffer::_next(unsigned index) +{ + return (0 == index) ? _num_items : (index - 1); +} + +bool +RingBuffer::empty() +{ + return _tail == _head; +} + +bool +RingBuffer::full() +{ + return _next(_head) == _tail; +} + +unsigned +RingBuffer::size() +{ + return (_buf != nullptr) ? _num_items : 0; +} + +void +RingBuffer::flush() +{ + while (!empty()) + get(NULL); +} + +bool +RingBuffer::put(const void *val, size_t val_size) { unsigned next = _next(_head); if (next != _tail) { - _buf[_head] = val; + if ((val_size == 0) || (val_size > _item_size)) + val_size = _item_size; + memcpy(&_buf[_head * _item_size], val, val_size); _head = next; return true; } else { @@ -152,52 +224,286 @@ bool RingBuffer<T>::put(T &val) } } -template <typename T> -bool RingBuffer<T>::put(const T &val) +bool +RingBuffer::put(int8_t val) { - unsigned next = _next(_head); - if (next != _tail) { - _buf[_head] = val; - _head = next; - return true; - } else { - return false; + return put(&val, sizeof(val)); +} + +bool +RingBuffer::put(uint8_t val) +{ + return put(&val, sizeof(val)); +} + +bool +RingBuffer::put(int16_t val) +{ + return put(&val, sizeof(val)); +} + +bool +RingBuffer::put(uint16_t val) +{ + return put(&val, sizeof(val)); +} + +bool +RingBuffer::put(int32_t val) +{ + return put(&val, sizeof(val)); +} + +bool +RingBuffer::put(uint32_t val) +{ + return put(&val, sizeof(val)); +} + +bool +RingBuffer::put(int64_t val) +{ + return put(&val, sizeof(val)); +} + +bool +RingBuffer::put(uint64_t val) +{ + return put(&val, sizeof(val)); +} + +bool +RingBuffer::put(float val) +{ + return put(&val, sizeof(val)); +} + +bool +RingBuffer::put(double val) +{ + return put(&val, sizeof(val)); +} + +bool +RingBuffer::force(const void *val, size_t val_size) +{ + bool overwrote = false; + + for (;;) { + if (put(val, val_size)) + break; + get(NULL); + overwrote = true; } + return overwrote; +} + +bool +RingBuffer::force(int8_t val) +{ + return force(&val, sizeof(val)); +} + +bool +RingBuffer::force(uint8_t val) +{ + return force(&val, sizeof(val)); +} + +bool +RingBuffer::force(int16_t val) +{ + return force(&val, sizeof(val)); +} + +bool +RingBuffer::force(uint16_t val) +{ + return force(&val, sizeof(val)); +} + +bool +RingBuffer::force(int32_t val) +{ + return force(&val, sizeof(val)); +} + +bool +RingBuffer::force(uint32_t val) +{ + return force(&val, sizeof(val)); } -template <typename T> -bool RingBuffer<T>::get(T &val) +bool +RingBuffer::force(int64_t val) +{ + return force(&val, sizeof(val)); +} + +bool +RingBuffer::force(uint64_t val) +{ + return force(&val, sizeof(val)); +} + +bool +RingBuffer::force(float val) +{ + return force(&val, sizeof(val)); +} + +bool +RingBuffer::force(double val) +{ + return force(&val, sizeof(val)); +} + +bool +RingBuffer::get(void *val, size_t val_size) { if (_tail != _head) { - val = _buf[_tail]; - _tail = _next(_tail); + unsigned candidate; + unsigned next; + + if ((val_size == 0) || (val_size > _item_size)) + val_size = _item_size; + + do { + /* decide which element we think we're going to read */ + candidate = _tail; + + /* and what the corresponding next index will be */ + next = _next(candidate); + + /* go ahead and read from this index */ + if (val != NULL) + memcpy(val, &_buf[candidate * _item_size], val_size); + + /* if the tail pointer didn't change, we got our item */ + } while (!__sync_bool_compare_and_swap(&_tail, candidate, next)); + return true; } else { return false; } } -template <typename T> -T RingBuffer<T>::get(void) +bool +RingBuffer::get(int8_t &val) +{ + return get(&val, sizeof(val)); +} + +bool +RingBuffer::get(uint8_t &val) { - T val; - return get(val) ? val : 0; + return get(&val, sizeof(val)); } -template <typename T> -unsigned RingBuffer<T>::space(void) +bool +RingBuffer::get(int16_t &val) { - return (_tail >= _head) ? (_size - (_tail - _head)) : (_head - _tail - 1); + return get(&val, sizeof(val)); } -template <typename T> -unsigned RingBuffer<T>::count(void) +bool +RingBuffer::get(uint16_t &val) { - return _size - space(); + return get(&val, sizeof(val)); +} + +bool +RingBuffer::get(int32_t &val) +{ + return get(&val, sizeof(val)); +} + +bool +RingBuffer::get(uint32_t &val) +{ + return get(&val, sizeof(val)); +} + +bool +RingBuffer::get(int64_t &val) +{ + return get(&val, sizeof(val)); +} + +bool +RingBuffer::get(uint64_t &val) +{ + return get(&val, sizeof(val)); +} + +bool +RingBuffer::get(float &val) +{ + return get(&val, sizeof(val)); +} + +bool +RingBuffer::get(double &val) +{ + return get(&val, sizeof(val)); +} + +unsigned +RingBuffer::space(void) +{ + unsigned tail, head; + + /* + * Make a copy of the head/tail pointers in a fashion that + * may err on the side of under-estimating the free space + * in the buffer in the case that the buffer is being updated + * asynchronously with our check. + * If the head pointer changes (reducing space) while copying, + * re-try the copy. + */ + do { + head = _head; + tail = _tail; + } while (head != _head); + + return (tail >= head) ? (_num_items - (tail - head)) : (head - tail - 1); +} + +unsigned +RingBuffer::count(void) +{ + /* + * Note that due to the conservative nature of space(), this may + * over-estimate the number of items in the buffer. + */ + return _num_items - space(); +} + +bool +RingBuffer::resize(unsigned new_size) +{ + char *old_buffer; + char *new_buffer = new char [(new_size+1) * _item_size]; + if (new_buffer == nullptr) { + return false; + } + old_buffer = _buf; + _buf = new_buffer; + _num_items = new_size; + _head = new_size; + _tail = new_size; + delete[] old_buffer; + return true; } -template <typename T> -unsigned RingBuffer<T>::_next(unsigned index) +void +RingBuffer::print_info(const char *name) { - return (0 == index) ? _size : (index - 1); + printf("%s %u/%u (%u/%u @ %p)\n", + name, + _num_items, + _num_items * _item_size, + _head, + _tail, + _buf); } |