ARDOUR::DSP::DspShm Class Reference

#include <dsp_filter.h>

Public Member Functions
	DspShm (size_t s=0)
	~DspShm ()
void	allocate (size_t s)
void	clear ()
float *	to_float (size_t off)
int32_t *	to_int (size_t off)
void	atomic_set_int (size_t off, int32_t val)
int32_t	atomic_get_int (size_t off)

Private Attributes
void *	_data
size_t	_size

Detailed Description

C/C++ Shared Memory

A convenience class representing a C array of float[] or int32_t[] data values. This is useful for lua scripts to perform DSP operations directly using C/C++ with CPU Hardware acceleration.

Access to this memory area is always 4 byte aligned. The data is interpreted either as float or as int.

This memory area can also be shared between different instances or the same lua plugin (DSP, GUI).

Since memory allocation is not realtime safe it should be allocated during dsp_init() or dsp_configure(). The memory is free()ed automatically when the lua instance is destroyed.

Definition at line 55 of file dsp_filter.h.

Constructor & Destructor Documentation

DspShm()

ARDOUR::DSP::DspShm::DspShm ( size_t  s = 0 )

inline

Definition at line 57 of file dsp_filter.h.

~DspShm()

ARDOUR::DSP::DspShm::~DspShm ( )

inline

Definition at line 66 of file dsp_filter.h.

Member Function Documentation

allocate()

void ARDOUR::DSP::DspShm::allocate ( size_t  s )

inline

[re] allocate memory in host's memory space

Parameters

s	size, total number of float or integer elements to store.

Definition at line 74 of file dsp_filter.h.

atomic_get_int()

int32_t ARDOUR::DSP::DspShm::atomic_get_int ( size_t  off )

inline

atomically read integer at offset

This involves a memory barrier. This call is intended for buffers which are shared with another instance.

Parameters

off	offset in shared memory region

Returns

value at offset

Definition at line 132 of file dsp_filter.h.

atomic_set_int()

void ARDOUR::DSP::DspShm::atomic_set_int ( size_t  off, int32_t  val  )

inline

atomically set integer at offset

This involves a memory barrier. This call is intended for buffers which are shared with another instance.

Parameters

off	offset in shared memory region
val	value to set

Definition at line 115 of file dsp_filter.h.

clear()

void ARDOUR::DSP::DspShm::clear ( )

inline

clear memory (set to zero)

Definition at line 82 of file dsp_filter.h.

to_float()

float* ARDOUR::DSP::DspShm::to_float ( size_t  off )

inline

access memory as float array

Parameters

off	offset in shared memory region

Returns

float[]

Definition at line 91 of file dsp_filter.h.

to_int()

int32_t* ARDOUR::DSP::DspShm::to_int ( size_t  off )

inline

access memory as integer array

Parameters

off	offset in shared memory region

Returns

int_32_t[]

Definition at line 101 of file dsp_filter.h.

Member Data Documentation

_data

void* ARDOUR::DSP::DspShm::_data

private

Definition at line 141 of file dsp_filter.h.

_size

size_t ARDOUR::DSP::DspShm::_size

private

Definition at line 142 of file dsp_filter.h.

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

• dsp_filter.h