gr::buffer_single_mapped Class Reference

A single mapped buffer where wrapping conditions are handled explicitly via input/output_blocked_callback functions called from block_executor. More...

#include <gnuradio/buffer_single_mapped.h>

Public Member Functions
	~buffer_single_mapped () override
block_sptr	buf_owner ()
	Return the block that owns this buffer.
int	space_available () override
	return number of items worth of space available for writing
void	update_reader_block_history (unsigned history, int delay) override
bool	input_blkd_cb_ready (int items_required, unsigned read_index) override
	Return true if thread is ready to call input_blocked_callback, false otherwise.
bool	input_blocked_callback (int items_required, int items_avail, unsigned read_index) override=0
	Callback function that the scheduler will call when it determines that the input is blocked. Override this function if needed.
bool	output_blkd_cb_ready (int output_multiple) override
	Return true if thread is ready to call the callback, false otherwise.
bool	output_blocked_callback (int output_multiple, bool force) override=0
	Callback function that the scheduler will call when it determines that the output is blocked.
Public Member Functions inherited from gr::buffer
	~buffer () override
buffer_mapping_type	get_mapping_type ()
	return the buffer's mapping type
unsigned int	bufsize () const
	return size of this buffer in items
const char *	base () const
	return the base address of the buffer
virtual void *	write_pointer ()
	return pointer to write buffer.
virtual const void *	_read_pointer (unsigned int read_index)
	return pointer to read buffer.
void	update_write_pointer (int nitems)
	tell buffer that we wrote nitems into it
void	set_done (bool done)
bool	done () const
block_sptr	link ()
	Return the block that writes to this buffer.
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 ()
void	add_item_tag (const tag_t &tag)
	Adds a new tag to the buffer.
void	remove_item_tag (const tag_t &tag, long id)
	Removes an existing tag from the buffer.
void	prune_tags (uint64_t max_time)
	Removes all tags before max_time from buffer.
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()
void	increment_active ()
	Increment the number of active pointers for this buffer.
void	decrement_active ()
	Decrement the number of active pointers for this buffer and signal anyone waiting when the count reaches zero.
void	on_lock (gr::thread::scoped_lock &lock) override
	"on_lock" function from the custom_lock_if.
void	on_unlock () override
	"on_unlock" function from the custom_lock_if.
void	set_transfer_type (const transfer_type &type)
	Assign buffer's transfer_type.
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
Public Attributes inherited from gr::buffer
gr::logger_ptr	d_logger
gr::logger_ptr	d_debug_logger

Protected Member Functions
bool	allocate_buffer (int nitems) override
	Make reasonable attempt to adjust nitems based on read/write granularity then delegate actual allocation to do_allocate_buffer().
virtual bool	do_allocate_buffer (size_t final_nitems, size_t sizeof_item)=0
	Do actual buffer allocation. This is intended (required) to be handled by the derived class.
unsigned	index_add (unsigned a, unsigned b) override
	Increment read or write index for this buffer.
unsigned	index_sub (unsigned a, unsigned b) override
	Decrement read or write index for this buffer.
	buffer_single_mapped (int nitems, size_t sizeof_item, uint64_t downstream_lcm_nitems, uint32_t downstream_max_out_mult, block_sptr link, block_sptr buf_owner)
	constructor is private. Use gr_make_buffer to create instances.
virtual bool	input_blocked_callback_logic (int items_required, int items_avail, unsigned read_index, char *buffer_ptr, mem_func_t const &memcpy_func, mem_func_t const &memmove_func)
	Abstracted logic for the input blocked callback function.
virtual bool	output_blocked_callback_logic (int output_multiple, bool force, char *buffer_ptr, mem_func_t const &memmove_func)
	Abstracted logic for the output blocked callback function.
Protected Member Functions inherited from 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)
	constructor is private. Use gr_make_buffer to create instances.
void	drop_reader (buffer_reader *reader)
	disassociate reader from this buffer

Protected Attributes
block_sptr	d_buf_owner
std::unique_ptr< char[]>	d_buffer
Protected Attributes inherited from gr::buffer
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
GR_RUNTIME_API buffer_sptr	make_buffer (int nitems, size_t sizeof_item, uint64_t downstream_lcm_nitems, block_sptr link, block_sptr buf_owner)

Detailed Description

A single mapped buffer where wrapping conditions are handled explicitly via input/output_blocked_callback functions called from block_executor.

Constructor & Destructor Documentation

~buffer_single_mapped()

gr::buffer_single_mapped::~buffer_single_mapped ( )

override

buffer_single_mapped()

gr::buffer_single_mapped::buffer_single_mapped ( int  nitems, size_t  sizeof_item, uint64_t  downstream_lcm_nitems, uint32_t  downstream_max_out_mult, block_sptr  link, block_sptr  buf_owner  )

protected

constructor is private. Use gr_make_buffer to create instances.

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

Parameters

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 blocks
downstream_max_out_mult	is the maximum output multiple of all downstream blocks
link	is the block that writes to this buffer.
buf_owner	if the block that owns the buffer which may or may not be the same as 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

allocate_buffer()

bool gr::buffer_single_mapped::allocate_buffer ( int  nitems )

overrideprotectedvirtual

Make reasonable attempt to adjust nitems based on read/write granularity then delegate actual allocation to do_allocate_buffer().

Returns

true iff successful.

Reimplemented from gr::buffer.

buf_owner()

block_sptr gr::buffer_single_mapped::buf_owner ( )

inline

Return the block that owns this buffer.

do_allocate_buffer()

virtual bool gr::buffer_single_mapped::do_allocate_buffer ( size_t  final_nitems, size_t  sizeof_item  )

protectedpure virtual

Do actual buffer allocation. This is intended (required) to be handled by the derived class.

Implemented in gr::host_buffer.

index_add()

unsigned gr::buffer_single_mapped::index_add ( unsigned  a, unsigned  b  )

inlineoverrideprotectedvirtual

Increment read or write index for this buffer.

Implements gr::buffer.

index_sub()

unsigned gr::buffer_single_mapped::index_sub ( unsigned  a, unsigned  b  )

inlineoverrideprotectedvirtual

Decrement read or write index for this buffer.

Implements gr::buffer.

input_blkd_cb_ready()

bool gr::buffer_single_mapped::input_blkd_cb_ready ( int  items_required, unsigned  read_index  )

overridevirtual

Return true if thread is ready to call input_blocked_callback, false otherwise.

Reimplemented from gr::buffer.

input_blocked_callback()

bool gr::buffer_single_mapped::input_blocked_callback ( int  items_required, int  items_avail, unsigned  read_index  )

overridepure virtual

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

Reimplemented from gr::buffer.

Implemented in gr::host_buffer.

input_blocked_callback_logic()

virtual bool gr::buffer_single_mapped::input_blocked_callback_logic ( int  items_required, int  items_avail, unsigned  read_index, char *  buffer_ptr, mem_func_t const &  memcpy_func, mem_func_t const &  memmove_func  )

protectedvirtual

Abstracted logic for the input blocked callback function.

This function contains the logic for the input blocked callback however the data adjustment portion of the callback has been abstracted to allow the caller to pass in the desired buffer and corresponding buffer manipulation functions (memcpy and memmove).

The input blocked callback is called when a reader needs to read more data than is available in a buffer and the available data is located at the end of the buffer. The input blocked callback will attempt to move any data located at the beginning of the buffer "down", and will then attempt to copy from the end of the buffer back to the beginning of the buffer. This process explicitly handles wrapping for a single mapped buffer and will realign the data at the beginning of the buffer such that the reader is able to read the available data and becomes unblocked.

Parameters

items_required	is the number of items required by the reader
items_avail	is the number of items available
read_index	is the current read index of the buffer reader caller
buffer_ptr	is the pointer to the desired buffer
memcpy_func	is a pointer to a memcpy function appropriate for the the passed in buffer
memmove_func	is a pointer to a memmove function appropriate for the passed in buffer

output_blkd_cb_ready()

bool gr::buffer_single_mapped::output_blkd_cb_ready ( int  output_multiple )

overridevirtual

Return true if thread is ready to call the callback, false otherwise.

Reimplemented from gr::buffer.

output_blocked_callback()

bool gr::buffer_single_mapped::output_blocked_callback ( int  output_multiple, bool  force  )

overridepure virtual

Callback function that the scheduler will call when it determines that the output is blocked.

Reimplemented from gr::buffer.

Implemented in gr::host_buffer.

output_blocked_callback_logic()

virtual bool gr::buffer_single_mapped::output_blocked_callback_logic ( int  output_multiple, bool  force, char *  buffer_ptr, mem_func_t const &  memmove_func  )

protectedvirtual

Abstracted logic for the output blocked callback function.

This function contains the logic for the output blocked callback however the data adjustment portion of the callback has been abstracted to allow the caller to pass in the desired buffer and corresponding buffer manipulation functions (memcpy and memmove).

The output blocked callback is called when a block needs to write data to the end of a single mapped buffer but not enough free space exists to write the data before the end of the buffer is reached. The output blocked callback will attempt to copy data located towards the end of a single mapped buffer back to the beginning of the buffer. This process explicitly handles wrapping for a single mapped buffer and will realign data located at the end of a buffer back to the beginning of the buffer such that the writing block can write its output into the buffer after the existing data.

Parameters

output_multiple
force	run the callback disregarding the internal checks
buffer_ptr	is the pointer to the desired buffer
memmove_func	is a pointer to a memmove function appropriate for the passed in buffer

space_available()

int gr::buffer_single_mapped::space_available ( )

overridevirtual

return number of items worth of space available for writing

Implements gr::buffer.

update_reader_block_history()

void gr::buffer_single_mapped::update_reader_block_history ( unsigned  history, int  delay  )

overridevirtual

Reimplemented from gr::buffer.

Friends And Related Symbol Documentation

buffer_reader

friend class buffer_reader

friend

make_buffer

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

friend

Member Data Documentation

d_buf_owner

block_sptr gr::buffer_single_mapped::d_buf_owner

protected

d_buffer

std::unique_ptr<char[]> gr::buffer_single_mapped::d_buffer

protected

d_debug_logger

gr::logger_ptr gr::buffer_single_mapped::d_debug_logger

d_logger

gr::logger_ptr gr::buffer_single_mapped::d_logger

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

• buffer_single_mapped.h