gr::buffer Class Reference

Single writer, multiple reader fifo. More...

#include <gnuradio/buffer.h>

Public Member Functions
	~buffer () override
buffer_mapping_type	get_mapping_type ()
	return the buffer's mapping type More...
virtual int	space_available ()=0
	return number of items worth of space available for writing More...
unsigned int	bufsize () const
	return size of this buffer in items More...
const char *	base () const
	return the base address of the buffer More...
virtual void *	write_pointer ()
	return pointer to write buffer. More...
virtual const void *	_read_pointer (unsigned int read_index)
	return pointer to read 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 ()
uint64_t	get_downstream_lcm_nitems ()
uint32_t	get_max_reader_output_multiple ()
virtual void	update_reader_block_history (unsigned history, [[maybe_unused]] int delay)
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)
virtual void	post_work (int nitems)=0
	Function to be executed after this object's owner completes the call to general_work() More...
virtual bool	input_blkd_cb_ready ([[maybe_unused]] int items_required, [[maybe_unused]] unsigned read_index)
	Returns true when the current thread is ready to call the callback, false otherwise. Note if input_blocked_callback is overridden then this function should also be overridden. More...
virtual bool	input_blocked_callback ([[maybe_unused]] int items_required, [[maybe_unused]] int items_avail, [[maybe_unused]] unsigned read_index)
	Callback function that the scheduler will call when it determines that the input is blocked. Override this function if needed. More...
virtual bool	output_blkd_cb_ready ([[maybe_unused]] int output_multiple)
	Returns true if the current thread is ready to execute output_blocked_callback(), false otherwise. Note if the default output_blocked_callback is overridden this function should also be overridden. More...
virtual bool	output_blocked_callback ([[maybe_unused]] int output_multiple, [[maybe_unused]] bool force=false)
	Callback function that the scheduler will call when it determines that the output is blocked. Override this function if needed. More...
void	increment_active ()
	Increment the number of active pointers for this buffer. More...
void	decrement_active ()
	Decrement the number of active pointers for this buffer and signal anyone waiting when the count reaches zero. More...
void	on_lock (gr::thread::scoped_lock &lock) override
	"on_lock" function from the custom_lock_if. More...
void	on_unlock () override
	"on_unlock" function from the custom_lock_if. More...
void	set_transfer_type (const transfer_type &type)
	Assign buffer's transfer_type. More...
Public Member Functions inherited from gr::custom_lock_if
virtual	~custom_lock_if ()

Public Attributes
gr::logger_ptr	d_logger
gr::logger_ptr	d_debug_logger

Protected Member Functions
virtual unsigned	index_add (unsigned a, unsigned b)=0
	Increment read or write index for this buffer. More...
virtual unsigned	index_sub (unsigned a, unsigned b)=0
	Decrement read or write index for this buffer. More...
virtual bool	allocate_buffer ([[maybe_unused]] int nitems)
	buffer (buffer_mapping_type buftype, int nitems, size_t sizeof_item, uint64_t downstream_lcm_nitems, uint32_t downstream_max_out_mult, block_sptr link)
	constructor is private. Use gr_make_buffer to create instances. More...
void	drop_reader (buffer_reader *reader)
	disassociate reader from this buffer More...

Protected Attributes
char *	d_base
unsigned int	d_bufsize
buffer_mapping_type	d_buf_map_type
unsigned	d_max_reader_delay
unsigned	d_max_reader_history
bool	d_has_history
size_t	d_sizeof_item
std::vector< buffer_reader * >	d_readers
std::weak_ptr< block >	d_link
gr::thread::mutex	d_mutex
unsigned int	d_write_index
uint64_t	d_abs_write_offset
bool	d_done
std::multimap< uint64_t, tag_t >	d_item_tags
uint64_t	d_last_min_items_read
gr::thread::condition_variable	d_cv
bool	d_callback_flag
uint32_t	d_active_pointer_counter
uint64_t	d_downstream_lcm_nitems
uint64_t	d_write_multiple
uint32_t	d_max_reader_output_multiple
transfer_type	d_transfer_type

Friends
class	buffer_reader
class	buffer_reader_sm
std::ostream &	operator<< (std::ostream &os, const buffer &buf)
GR_RUNTIME_API buffer_sptr	make_buffer (int nitems, size_t sizeof_item, uint64_t downstream_lcm_nitems, block_sptr link)
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()

gr::buffer::~buffer ( )

override

buffer()

gr::buffer::buffer ( buffer_mapping_type  buftype, int  nitems, size_t  sizeof_item, uint64_t  downstream_lcm_nitems, uint32_t  downstream_max_out_mult, block_sptr  link  )

protected

constructor is private. Use gr_make_buffer to create instances.

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

Parameters

buftype	is an enum type that describes the buffer TODO: fix me
nitems	is the minimum number of items the buffer will hold.
sizeof_item	is the size of an item in bytes.
downstream_lcm_nitems	is the least common multiple of the items to read by downstream block(s)
downstream_max_out_mult	is the maximum output multiple of all downstream blocks
link	is the block that writes to this buffer.

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.

Member Function Documentation

_read_pointer()

virtual const void* gr::buffer::_read_pointer ( unsigned int  read_index )

virtual

return pointer to read buffer.

The return value points to at least items_available() items.

Reimplemented in gr::host_buffer.

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

allocate_buffer()

virtual bool gr::buffer::allocate_buffer ( [[maybe_unused] ] int  nitems )

inlineprotectedvirtual

base()

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

inline

return the base address of the buffer

bufsize()

unsigned int gr::buffer::bufsize ( ) const

inline

return size of this buffer in items

decrement_active()

void gr::buffer::decrement_active ( )

inline

Decrement the number of active pointers for this buffer and signal anyone waiting when the count reaches zero.

done()

bool gr::buffer::done ( ) const

inline

drop_reader()

void gr::buffer::drop_reader ( buffer_reader *  reader )

protected

disassociate reader from this buffer

get_downstream_lcm_nitems()

uint64_t gr::buffer::get_downstream_lcm_nitems ( )

inline

get_mapping_type()

buffer_mapping_type gr::buffer::get_mapping_type ( )

inline

return the buffer's mapping type

get_max_reader_output_multiple()

uint32_t gr::buffer::get_max_reader_output_multiple ( )

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

increment_active()

void gr::buffer::increment_active ( )

inline

Increment the number of active pointers for this buffer.

index_add()

virtual unsigned gr::buffer::index_add ( unsigned  a, unsigned  b  )

protectedpure virtual

Increment read or write index for this buffer.

Implemented in gr::buffer_single_mapped, and gr::buffer_double_mapped.

index_sub()

virtual unsigned gr::buffer::index_sub ( unsigned  a, unsigned  b  )

protectedpure virtual

Decrement read or write index for this buffer.

Implemented in gr::buffer_single_mapped, and gr::buffer_double_mapped.

input_blkd_cb_ready()

virtual bool gr::buffer::input_blkd_cb_ready ( [[maybe_unused] ] int  items_required, [[maybe_unused] ] unsigned  read_index  )

inlinevirtual

Returns true when the current thread is ready to call the callback, false otherwise. Note if input_blocked_callback is overridden then this function should also be overridden.

input_blocked_callback()

virtual bool gr::buffer::input_blocked_callback ( [[maybe_unused] ] int  items_required, [[maybe_unused] ] int  items_avail, [[maybe_unused] ] unsigned  read_index  )

inlinevirtual

Callback function that the scheduler will call when it determines that the input is blocked. Override this function if needed.

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

on_lock()

void gr::buffer::on_lock ( gr::thread::scoped_lock &  lock )

overridevirtual

"on_lock" function from the custom_lock_if.

Implements gr::custom_lock_if.

on_unlock()

void gr::buffer::on_unlock ( )

overridevirtual

"on_unlock" function from the custom_lock_if.

Implements gr::custom_lock_if.

output_blkd_cb_ready()

virtual bool gr::buffer::output_blkd_cb_ready ( [[maybe_unused] ] int  output_multiple )

inlinevirtual

Returns true if the current thread is ready to execute output_blocked_callback(), false otherwise. Note if the default output_blocked_callback is overridden this function should also be overridden.

output_blocked_callback()

virtual bool gr::buffer::output_blocked_callback ( [[maybe_unused] ] int  output_multiple, [[maybe_unused] ] bool  force = false  )

inlinevirtual

Callback function that the scheduler will call when it determines that the output is blocked. Override this function if needed.

post_work()

virtual void gr::buffer::post_work ( int  nitems )

pure virtual

Function to be executed after this object's owner completes the call to general_work()

Implemented in gr::host_buffer.

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

)

set_transfer_type()

void gr::buffer::set_transfer_type

(

const transfer_type &

type

)

Assign buffer's transfer_type.

space_available()

virtual int gr::buffer::space_available ( )

pure virtual

return number of items worth of space available for writing

Implemented in gr::buffer_single_mapped, and gr::buffer_double_mapped.

update_reader_block_history()

virtual void gr::buffer::update_reader_block_history ( unsigned  history, [[maybe_unused] ] int  delay  )

inlinevirtual

update_write_pointer()

void gr::buffer::update_write_pointer

(

int

nitems

)

tell buffer that we wrote nitems into it

write_pointer()

virtual void* gr::buffer::write_pointer ( )

virtual

return pointer to write buffer.

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

Reimplemented in gr::host_buffer.

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

buffer_reader_sm

friend class buffer_reader_sm

friend

make_buffer

GR_RUNTIME_API buffer_sptr make_buffer ( int  nitems, size_t  sizeof_item, uint64_t  downstream_lcm_nitems, block_sptr  link  )

friend

operator<<

std::ostream& operator<< ( std::ostream &  os, const buffer &  buf  )

friend

Member Data Documentation

d_abs_write_offset

uint64_t gr::buffer::d_abs_write_offset

protected

d_active_pointer_counter

uint32_t gr::buffer::d_active_pointer_counter

protected

d_base

char* gr::buffer::d_base

protected

d_buf_map_type

buffer_mapping_type gr::buffer::d_buf_map_type

protected

d_bufsize

unsigned int gr::buffer::d_bufsize

protected

d_callback_flag

bool gr::buffer::d_callback_flag

protected

d_cv

gr::thread::condition_variable gr::buffer::d_cv

protected

d_debug_logger

gr::logger_ptr gr::buffer::d_debug_logger

d_done

bool gr::buffer::d_done

protected

d_downstream_lcm_nitems

uint64_t gr::buffer::d_downstream_lcm_nitems

protected

d_has_history

bool gr::buffer::d_has_history

protected

d_item_tags

std::multimap<uint64_t, tag_t> gr::buffer::d_item_tags

protected

d_last_min_items_read

uint64_t gr::buffer::d_last_min_items_read

protected

d_link

std::weak_ptr<block> gr::buffer::d_link

protected

d_logger

gr::logger_ptr gr::buffer::d_logger

d_max_reader_delay

unsigned gr::buffer::d_max_reader_delay

protected

d_max_reader_history

unsigned gr::buffer::d_max_reader_history

protected

d_max_reader_output_multiple

uint32_t gr::buffer::d_max_reader_output_multiple

protected

d_mutex

gr::thread::mutex gr::buffer::d_mutex

protected

d_readers

std::vector<buffer_reader*> gr::buffer::d_readers

protected

d_sizeof_item

size_t gr::buffer::d_sizeof_item

protected

d_transfer_type

transfer_type gr::buffer::d_transfer_type

protected

d_write_index

unsigned int gr::buffer::d_write_index

protected

d_write_multiple

uint64_t gr::buffer::d_write_multiple

protected

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

• buffer.h