sbl::primitives::buffers::RingBuffer< T, Size, MemoryBarrierImpl > Class Template Reference

Lock-free single-producer-single-consumer ring buffer. More...

#include <ring_buffer.hpp>

Collaboration diagram for sbl::primitives::buffers::RingBuffer< T, Size, MemoryBarrierImpl >:

Public Member Functions
	RingBuffer ()
	Construct empty ring buffer.
bool	push (const T &item)
	Push element to buffer (producer side)
bool	pop (T &item)
	Pop element from buffer (consumer side)
bool	empty () const
	Check if buffer is empty.
bool	full () const
	Check if buffer is full.
uint32_t	size () const
	Get number of elements in buffer.
constexpr uint32_t	capacity () const
	Get maximum buffer capacity.
void	clear ()
	Clear all elements from buffer.

Detailed Description

template<typename T, uint32_t Size, typename MemoryBarrierImpl>
class sbl::primitives::buffers::RingBuffer< T, Size, MemoryBarrierImpl >

Lock-free single-producer-single-consumer ring buffer.

Thread-safe ring buffer designed for communication between ISR and main contexts. Uses volatile indices and memory barriers to ensure data coherency without locks or blocking operations.

On single-core Cortex-M, volatile guarantees that reads/writes are not optimized away or reordered by the compiler. The memory barrier (provided via template parameter) ensures data is committed before the index update becomes visible.

Key features:

• Lock-free operation - never blocks ISR
• Power-of-2 sizing for fast modulo operations
• Memory barriers for correct ordering
• Bounded execution time in ISR context
• No dynamic allocation - all storage static

Usage:

// Create ring buffer for audio samples
RingBuffer<int16_t, 256, MemoryBarrier> audio_buffer;
 
// In ISR (producer)
ISR(ADC_COMPLETE) {
    int16_t sample = ADC_read();
    if (!audio_buffer.push(sample)) {
        // Buffer full - handle overflow
    }
}
 
// In main loop (consumer)
void process_audio() {
    int16_t sample;
    while (audio_buffer.pop(sample)) {
        // Process sample
        apply_filter(sample);
    }
}

Template Parameters

T	Element type to store in buffer
Size	Buffer size (must be power of 2)
MemoryBarrierImpl	Platform-specific memory barrier implementation

Note

All public methods are ISR-safe — lock-free SPSC, bounded computation, no blocking.

Definition at line 72 of file ring_buffer.hpp.

Constructor & Destructor Documentation

RingBuffer()

template<typename T , uint32_t Size, typename MemoryBarrierImpl >

sbl::primitives::buffers::RingBuffer< T, Size, MemoryBarrierImpl >::RingBuffer ( )

inline

Construct empty ring buffer.

Definition at line 81 of file ring_buffer.hpp.

Member Function Documentation

capacity()

template<typename T , uint32_t Size, typename MemoryBarrierImpl >

constexpr uint32_t sbl::primitives::buffers::RingBuffer< T, Size, MemoryBarrierImpl >::capacity ( ) const

inlineconstexpr

Get maximum buffer capacity.

Returns

Maximum number of elements buffer can hold

Definition at line 180 of file ring_buffer.hpp.

clear()

template<typename T , uint32_t Size, typename MemoryBarrierImpl >

void sbl::primitives::buffers::RingBuffer< T, Size, MemoryBarrierImpl >::clear ( )

inline

Clear all elements from buffer.

Resets buffer to empty state. Should only be called when both producer and consumer are stopped to avoid data races.

Definition at line 190 of file ring_buffer.hpp.

empty()

template<typename T , uint32_t Size, typename MemoryBarrierImpl >

bool sbl::primitives::buffers::RingBuffer< T, Size, MemoryBarrierImpl >::empty ( ) const

inline

Check if buffer is empty.

Returns

true if buffer contains no elements

Definition at line 151 of file ring_buffer.hpp.

full()

template<typename T , uint32_t Size, typename MemoryBarrierImpl >

bool sbl::primitives::buffers::RingBuffer< T, Size, MemoryBarrierImpl >::full ( ) const

inline

Check if buffer is full.

Returns

true if buffer cannot accept more elements

Definition at line 160 of file ring_buffer.hpp.

pop()

template<typename T , uint32_t Size, typename MemoryBarrierImpl >

bool sbl::primitives::buffers::RingBuffer< T, Size, MemoryBarrierImpl >::pop ( T &  item )

inline

Pop element from buffer (consumer side)

Removes and returns the oldest element from the buffer if available. This method is designed to be called from the consumer context (typically the main thread).

Parameters

item	Reference to store popped element

Returns

true if element was popped, false if buffer is empty

Definition at line 126 of file ring_buffer.hpp.

push()

template<typename T , uint32_t Size, typename MemoryBarrierImpl >

bool sbl::primitives::buffers::RingBuffer< T, Size, MemoryBarrierImpl >::push ( const T &  item )

inline

Push element to buffer (producer side)

Adds element to the buffer if space is available. This method is ISR-safe and designed to be called from the producer context (typically an interrupt handler).

Parameters

item	Element to add to buffer

Returns

true if element was added, false if buffer is full

Note

This method has bounded execution time suitable for ISR use

Definition at line 95 of file ring_buffer.hpp.

size()

template<typename T , uint32_t Size, typename MemoryBarrierImpl >

uint32_t sbl::primitives::buffers::RingBuffer< T, Size, MemoryBarrierImpl >::size ( ) const

inline

Get number of elements in buffer.

Returns

Current number of elements

Note

This is a snapshot - value may change immediately after call

Definition at line 171 of file ring_buffer.hpp.

---

The documentation for this class was generated from the following file:

• src/sbl/primitives/buffers/ring_buffer.hpp