ac2xdf::acwriter_t< T > Class Template Reference

Inheritance diagram for ac2xdf::acwriter_t< T >:

Public Member Functions
	acwriter_t (bool active, unsigned fifosize, unsigned minwrite, const std::string &varname, double sampling_rate, output_file_t *outfile, uint32_t stream_id)
	Constructor allocates fifo and disk output buffer. More...
	acwriter_t (const acwriter_t &)=delete
	acwriter_t (acwriter_t &&)=delete
virtual	~acwriter_t ()=default
	Deallocates memory but does not terminate the write_thread. More...
void	process (comm_var_t &s) override
void	exit_request () override
	Terminate output thread. More...
const char *	get_varname () const override
Public Member Functions inherited from ac2xdf::acwriter_base_t
virtual	~acwriter_base_t ()=default

Private Member Functions
void	write_thread ()
	Main method of the disk writer thread. More...

Private Attributes
std::atomic< bool >	close_session
	cross-thread-synchronization. More...
const bool	active
	The writer thread and the output file will only be created when active is true. More...
std::unique_ptr< mha_fifo_lf_t< T > >	fifo
	Fifo for decoupling signal processing thread from disk writer thread. More...
const unsigned int	disk_write_threshold_min_num_samples
	Minimum number of samples that need to be waiting in the fifo before the disk writer thread writes them to disk. More...
std::thread	writethread
	The thread that writes to disk. More...
std::unique_ptr< T[]>	diskbuffer
	Intermediate buffer to receive data from fifo and store on disk. More...
output_file_t *	outfile
	Ouput file. More...
unsigned	num_channels = 0U
	Number of channels of AC variable using stride. More...
bool	is_num_channels_known = false
	The number of channels is determined during the first process callback. More...
bool	is_complex = false
	If the AC variable is of complex valued type or not. More...
unsigned int	data_type = MHA_AC_UNKNOWN
	Data type of the ac variable. Used to protect against data type change during processing. More...
const std::string	varname
	The name of the ac variable to publish. More...
const uint32_t	stream_id
bool	is_stream_initialized =false
double	sampling_rate

Constructor & Destructor Documentation

acwriter_t() [1/3]

template<typename T >

ac2xdf::acwriter_t< T >::acwriter_t	(	bool	active,
		unsigned	fifosize,
		unsigned	minwrite,
		const std::string &	varname,
		double	sampling_rate,
		output_file_t *	outfile,
		uint32_t	stream_id
	)

Constructor allocates fifo and disk output buffer.

It spawns a new thread for writing data to disk when active==true. In order to terminate the thread, method exit_request must be called before this object is destroyed.

Parameters

active	Only write data to disk when this is true.
fifosize	Capacity of both the fifo pipeline and of the disk buffer.
minwrite	Wait for a fifo fill count of at least minwrite doubles before flushing the contents of the fifo to disk. Fifo is also flushed before this object is destroyed.
varname	Name of AC variable to save into file. Can be accessed through getter method get_varname(). Stored here to avoid races between processing thread and configuration thread.
outfile	Handle to the output file
stream_id	Numerical id of the stream.

acwriter_t() [2/3]

template<typename T >

ac2xdf::acwriter_t< T >::acwriter_t ( const acwriter_t< T > &  )

delete

acwriter_t() [3/3]

template<typename T >

ac2xdf::acwriter_t< T >::acwriter_t ( acwriter_t< T > &&  )

delete

~acwriter_t()

template<typename T >

virtual ac2xdf::acwriter_t< T >::~acwriter_t ( )

virtualdefault

Deallocates memory but does not terminate the write_thread.

write_thread must be terminated before the destructor executes by calling exit_request.

Member Function Documentation

process()

template<typename T >

void ac2xdf::acwriter_t< T >::process ( comm_var_t &  s )

overridevirtual

Implements ac2xdf::acwriter_base_t.

exit_request()

template<typename T >

void ac2xdf::acwriter_t< T >::exit_request

overridevirtual

Terminate output thread.

Implements ac2xdf::acwriter_base_t.

get_varname()

template<typename T >

const char* ac2xdf::acwriter_t< T >::get_varname ( ) const

inlineoverridevirtual

Implements ac2xdf::acwriter_base_t.

write_thread()

template<typename T >

void ac2xdf::acwriter_t< T >::write_thread

private

Main method of the disk writer thread.

Periodically wakes up and checks if data needs to be written to disk.

Member Data Documentation

close_session

template<typename T >

std::atomic<bool> ac2xdf::acwriter_t< T >::close_session

private

cross-thread-synchronization.

write_thread() terminates after this is set to true by exit_request().

active

template<typename T >

const bool ac2xdf::acwriter_t< T >::active

private

The writer thread and the output file will only be created when active is true.

fifo

template<typename T >

std::unique_ptr<mha_fifo_lf_t<T> > ac2xdf::acwriter_t< T >::fifo

private

Fifo for decoupling signal processing thread from disk writer thread.

disk_write_threshold_min_num_samples

template<typename T >

const unsigned int ac2xdf::acwriter_t< T >::disk_write_threshold_min_num_samples

private

Minimum number of samples that need to be waiting in the fifo before the disk writer thread writes them to disk.

writethread

template<typename T >

std::thread ac2xdf::acwriter_t< T >::writethread

private

The thread that writes to disk.

diskbuffer

template<typename T >

std::unique_ptr<T[]> ac2xdf::acwriter_t< T >::diskbuffer

private

Intermediate buffer to receive data from fifo and store on disk.

outfile

template<typename T >

output_file_t* ac2xdf::acwriter_t< T >::outfile

private

Ouput file.

num_channels

template<typename T >

unsigned ac2xdf::acwriter_t< T >::num_channels = 0U

private

Number of channels of AC variable using stride.

If the number of channels changes during processing, an exception is thrown.

is_num_channels_known

template<typename T >

bool ac2xdf::acwriter_t< T >::is_num_channels_known = false

private

The number of channels is determined during the first process callback.

is_num_channels_known is set to true after the first process callback.

is_complex

template<typename T >

bool ac2xdf::acwriter_t< T >::is_complex = false

private

If the AC variable is of complex valued type or not.

If this changes during processing, then an exception is thrown.

data_type

template<typename T >

unsigned int ac2xdf::acwriter_t< T >::data_type = MHA_AC_UNKNOWN

private

Data type of the ac variable. Used to protect against data type change during processing.

varname

template<typename T >

const std::string ac2xdf::acwriter_t< T >::varname

private

The name of the ac variable to publish.

stream_id

template<typename T >

const uint32_t ac2xdf::acwriter_t< T >::stream_id

private

is_stream_initialized

template<typename T >

bool ac2xdf::acwriter_t< T >::is_stream_initialized =false

private

sampling_rate

template<typename T >

double ac2xdf::acwriter_t< T >::sampling_rate

private

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

• ac2xdf.hh
• ac2xdf.cpp