gr::buffer Class Reference

Single writer, multiple reader fifo. More...

#include <gnuradio/buffer.h>

Public Member Functions
virtual	~buffer ()
int	space_available ()
	return number of items worth of space available for writing More...
int	bufsize () const
	return size of this buffer in items More...
const char *	base () const
	return the base address of the buffer More...
void *	write_pointer ()
	return pointer to write buffer. More...
void	update_write_pointer (int nitems)
	tell buffer that we wrote nitems into it More...
void	set_done (bool done)
bool	done () const
block_sptr	link ()
	Return the block that writes to this buffer. More...
size_t	nreaders () const
buffer_reader *	reader (size_t index)
gr::thread::mutex *	mutex ()
uint64_t	nitems_written ()
void	reset_nitem_counter ()
size_t	get_sizeof_item ()
void	add_item_tag (const tag_t &tag)
	Adds a new tag to the buffer. More...
void	remove_item_tag (const tag_t &tag, long id)
	Removes an existing tag from the buffer. More...
void	prune_tags (uint64_t max_time)
	Removes all tags before max_time from buffer. More...
std::multimap< uint64_t, tag_t >::iterator	get_tags_begin ()
std::multimap< uint64_t, tag_t >::iterator	get_tags_end ()
std::multimap< uint64_t, tag_t >::iterator	get_tags_lower_bound (uint64_t x)
std::multimap< uint64_t, tag_t >::iterator	get_tags_upper_bound (uint64_t x)

Protected Attributes
char *	d_base
unsigned int	d_bufsize
unsigned	d_max_reader_delay

Friends
class	buffer_reader
GR_RUNTIME_API buffer_sptr	make_buffer (int nitems, size_t sizeof_item, block_sptr link)
	Allocate a buffer that holds at least nitems of size sizeof_item. More...
GR_RUNTIME_API buffer_reader_sptr	buffer_add_reader (buffer_sptr buf, int nzero_preload, block_sptr link, int delay)
	Create a new gr::buffer_reader and attach it to buffer buf. More...

Detailed Description

Single writer, multiple reader fifo.

Constructor & Destructor Documentation

~buffer()

virtual gr::buffer::~buffer ( )

virtual

Member Function Documentation

add_item_tag()

void gr::buffer::add_item_tag

(

const tag_t &

tag

)

Adds a new tag to the buffer.

Parameters

tag	the new tag

base()

const char* gr::buffer::base ( ) const

inline

return the base address of the buffer

bufsize()

int gr::buffer::bufsize ( ) const

inline

return size of this buffer in items

done()

bool gr::buffer::done ( ) const

inline

get_sizeof_item()

size_t gr::buffer::get_sizeof_item ( )

inline

get_tags_begin()

std::multimap<uint64_t, tag_t>::iterator gr::buffer::get_tags_begin ( )

inline

get_tags_end()

std::multimap<uint64_t, tag_t>::iterator gr::buffer::get_tags_end ( )

inline

get_tags_lower_bound()

std::multimap<uint64_t, tag_t>::iterator gr::buffer::get_tags_lower_bound ( uint64_t  x )

inline

get_tags_upper_bound()

std::multimap<uint64_t, tag_t>::iterator gr::buffer::get_tags_upper_bound ( uint64_t  x )

inline

link()

block_sptr gr::buffer::link ( )

inline

Return the block that writes to this buffer.

mutex()

gr::thread::mutex* gr::buffer::mutex ( )

inline

nitems_written()

uint64_t gr::buffer::nitems_written ( )

inline

nreaders()

size_t gr::buffer::nreaders ( ) const

inline

prune_tags()

void gr::buffer::prune_tags

(

uint64_t

max_time

)

Removes all tags before max_time from buffer.

Parameters

max_time

the time (item number) to trim up until.

reader()

buffer_reader* gr::buffer::reader ( size_t  index )

inline

remove_item_tag()

void gr::buffer::remove_item_tag	(	const tag_t &	tag,
		long	id
	)

Removes an existing tag from the buffer.

If no such tag is found, does nothing. Note: Doesn't actually physically delete the tag, but marks it as deleted. For the user, this has the same effect: Any subsequent calls to get_tags_in_range() will not return the tag.

Parameters

tag	the tag that needs to be removed
id	the unique ID of the block calling this function

reset_nitem_counter()

void gr::buffer::reset_nitem_counter ( )

inline

set_done()

void gr::buffer::set_done

(

bool

done

)

space_available()

int gr::buffer::space_available

(

)

return number of items worth of space available for writing

update_write_pointer()

void gr::buffer::update_write_pointer

(

int

nitems

)

tell buffer that we wrote nitems into it

write_pointer()

void* gr::buffer::write_pointer

(

)

return pointer to write buffer.

The return value points at space that can hold at least space_available() items.

Friends And Related Function Documentation

buffer_add_reader

GR_RUNTIME_API buffer_reader_sptr buffer_add_reader ( buffer_sptr  buf, int  nzero_preload, block_sptr  link, int  delay  )

friend

Create a new gr::buffer_reader and attach it to buffer buf.

Parameters

buf	is the buffer the gr::buffer_reader reads from.
nzero_preload	– number of zero items to "preload" into buffer.
link	is the block that reads from the buffer using this gr::buffer_reader.
delay	Optional setting to declare the buffer's sample delay.

buffer_reader

friend class buffer_reader

friend

make_buffer

GR_RUNTIME_API buffer_sptr make_buffer ( int  nitems, size_t  sizeof_item, block_sptr  link  )

friend

Allocate a buffer that holds at least nitems of size sizeof_item.

The total size of the buffer will be rounded up to a system dependent boundary. This is typically the system page size, but under MS windows is 64KB.

Parameters

nitems	is the minimum number of items the buffer will hold.
sizeof_item	is the size of an item in bytes.
link	is the block that writes to this buffer.

Member Data Documentation

d_base

char* gr::buffer::d_base

protected

d_bufsize

unsigned int gr::buffer::d_bufsize

protected

d_max_reader_delay

unsigned gr::buffer::d_max_reader_delay

protected

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

• buffer.h