The abstract base class for all 'terminal' processing blocks.A signal processing flow is constructed by creating a tree of hierarchical blocks, which at any level may also contain terminal nodes that actually implement signal processing functions. This is the base class for all such leaf nodes.
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Public Member Functions |
virtual | ~gr_block () |
unsigned | history () const |
void | set_history (unsigned history) |
bool | fixed_rate () const |
| Return true if this block has a fixed input to output rate.
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virtual void | forecast (int noutput_items, gr_vector_int &ninput_items_required) |
| Estimate input requirements given output request.
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virtual int | general_work (int noutput_items, gr_vector_int &ninput_items, gr_vector_const_void_star &input_items, gr_vector_void_star &output_items)=0 |
| compute output items from input items
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virtual bool | start () |
| Called to enable drivers, etc for i/o devices.
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virtual bool | stop () |
| Called to disable drivers, etc for i/o devices.
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void | set_output_multiple (int multiple) |
| Constrain the noutput_items argument passed to forecast and general_work.
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int | output_multiple () const |
bool | output_multiple_set () const |
void | set_alignment (int multiple) |
| Constrains buffers to work on a set item alignment (for SIMD)
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int | alignment () const |
void | set_unaligned (int na) |
int | unaligned () const |
void | set_is_unaligned (bool u) |
bool | is_unaligned () const |
void | consume (int which_input, int how_many_items) |
| Tell the scheduler how_many_items of input stream which_input were consumed.
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void | consume_each (int how_many_items) |
| Tell the scheduler how_many_items were consumed on each input stream.
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void | produce (int which_output, int how_many_items) |
| Tell the scheduler how_many_items were produced on output stream which_output .
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void | set_relative_rate (double relative_rate) |
| Set the approximate output rate / input rate.
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double | relative_rate () const |
| return the approximate output rate / input rate
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virtual int | fixed_rate_ninput_to_noutput (int ninput) |
| Given ninput samples, return number of output samples that will be produced. N.B. this is only defined if fixed_rate returns true. Generally speaking, you don't need to override this.
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virtual int | fixed_rate_noutput_to_ninput (int noutput) |
| Given noutput samples, return number of input samples required to produce noutput. N.B. this is only defined if fixed_rate returns true. Generally speaking, you don't need to override this.
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uint64_t | nitems_read (unsigned int which_input) |
| Return the number of items read on input stream which_input.
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uint64_t | nitems_written (unsigned int which_output) |
| Return the number of items written on output stream which_output.
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tag_propagation_policy_t | tag_propagation_policy () |
| Asks for the policy used by the scheduler to moved tags downstream.
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void | set_tag_propagation_policy (tag_propagation_policy_t p) |
| Set the policy by the scheduler to determine how tags are moved downstream.
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gr_block_detail_sptr | detail () const |
void | set_detail (gr_block_detail_sptr detail) |
virtual | ~gr_basic_block () |
long | unique_id () const |
std::string | name () const |
gr_io_signature_sptr | input_signature () const |
gr_io_signature_sptr | output_signature () const |
gr_basic_block_sptr | to_basic_block () |
virtual bool | check_topology (int ninputs, int noutputs) |
| Confirm that ninputs and noutputs is an acceptable combination.
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template<typename T > |
void | set_msg_handler (T msg_handler) |
| Set the callback that is fired when messages are available.
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| gr_msg_accepter () |
| ~gr_msg_accepter () |
void | post (pmt::pmt_t msg) |
| send msg to msg_accepter
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| msg_accepter () |
virtual | ~msg_accepter () |
Protected Member Functions |
| gr_block (void) |
| gr_block (const std::string &name, gr_io_signature_sptr input_signature, gr_io_signature_sptr output_signature) |
void | set_fixed_rate (bool fixed_rate) |
void | add_item_tag (unsigned int which_output, uint64_t abs_offset, const pmt::pmt_t &key, const pmt::pmt_t &value, const pmt::pmt_t &srcid=pmt::PMT_F) |
| Adds a new tag onto the given output buffer.
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void | add_item_tag (unsigned int which_output, const gr_tag_t &tag) |
| Adds a new tag onto the given output buffer.
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void | get_tags_in_range (std::vector< gr_tag_t > &v, unsigned int which_input, uint64_t abs_start, uint64_t abs_end) |
| Given a [start,end), returns a vector of all tags in the range.
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void | get_tags_in_range (std::vector< gr_tag_t > &v, unsigned int which_input, uint64_t abs_start, uint64_t abs_end, const pmt::pmt_t &key) |
| Given a [start,end), returns a vector of all tags in the range with a given key.
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| gr_basic_block (void) |
| gr_basic_block (const std::string &name, gr_io_signature_sptr input_signature, gr_io_signature_sptr output_signature) |
| Protected constructor prevents instantiation by non-derived classes.
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void | set_input_signature (gr_io_signature_sptr iosig) |
| may only be called during constructor
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void | set_output_signature (gr_io_signature_sptr iosig) |
| may only be called during constructor
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void | set_color (vcolor color) |
| Allow the flowgraph to set for sorting and partitioning.
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vcolor | color () const |
The abstract base class for all 'terminal' processing blocks.
A signal processing flow is constructed by creating a tree of hierarchical blocks, which at any level may also contain terminal nodes that actually implement signal processing functions. This is the base class for all such leaf nodes.
Blocks have a set of input streams and output streams. The input_signature and output_signature define the number of input streams and output streams respectively, and the type of the data items in each stream.
Although blocks may consume data on each input stream at a different rate, all outputs streams must produce data at the same rate. That rate may be different from any of the input rates.
User derived blocks override two methods, forecast and general_work, to implement their signal processing behavior. forecast is called by the system scheduler to determine how many items are required on each input stream in order to produce a given number of output items.
general_work is called to perform the signal processing in the block. It reads the input items and writes the output items.
compute output items from input items
- Parameters
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noutput_items | number of output items to write on each output stream |
ninput_items | number of input items available on each input stream |
input_items | vector of pointers to the input items, one entry per input stream |
output_items | vector of pointers to the output items, one entry per output stream |
- Returns
- number of items actually written to each output stream, or -1 on EOF. It is OK to return a value less than noutput_items. -1 <= return value <= noutput_items
general_work must call consume or consume_each to indicate how many items were consumed on each input stream.
Implemented in digital_pfb_clock_sync_ccf, digital_pfb_clock_sync_fff, gr_pfb_clock_sync_ccf, gr_pfb_clock_sync_fff, gr_pfb_channelizer_ccf, gr_pfb_arb_resampler_ccf, gr_pfb_arb_resampler_fff, qtgui_sink_c, qtgui_sink_f, digital_ofdm_frame_acquisition, trellis_siso_combined_f, gr_simple_correlator, digital_ofdm_insert_preamble, pager_flex_sync, trellis_siso_f, digital_mpsk_receiver_cc, gr_align_on_samplenumbers_ss, gr_stream_mux, gr_rational_resampler_base_ccc, gr_rational_resampler_base_ccf, gr_rational_resampler_base_fcc, gr_rational_resampler_base_fff, gr_rational_resampler_base_fsf, gr_rational_resampler_base_scc, digital_constellation_receiver_cb, gr_packed_to_unpacked_bb, gr_packed_to_unpacked_ii, gr_packed_to_unpacked_ss, gr_unpacked_to_packed_bb, gr_unpacked_to_packed_ii, gr_unpacked_to_packed_ss, gr_ofdm_bpsk_demapper, digital_clock_recovery_mm_cc, digital_ofdm_sampler, atsc_bit_timing_loop, gr_test, digital_constellation_decoder_cb, digital_simple_framer, gr_sync_interpolator, digital_clock_recovery_mm_ff, gr_copy, gr_sync_block, gr_sync_decimator, gr_keep_m_in_n, gr_delay, gr_skiphead, gr_keep_one_in_n, gr_squelch_base_cc, gr_squelch_base_ff, gr_nop, gr_simple_framer, noaa_hrpt_deframer, gr_vector_insert_b, atsc_field_sync_demux, gr_fractional_interpolator_cc, gr_fractional_interpolator_ff, and trellis_constellation_metrics_cf.
void gr_block::set_alignment |
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int |
multiple | ) |
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Constrains buffers to work on a set item alignment (for SIMD)
set_alignment_multiple causes the scheduler to ensure that the noutput_items argument passed to forecast and general_work will be an integer multiple of
- Parameters
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multiple | The default value is 1. |
This control is similar to the output_multiple setting, except that if the number of items passed to the block is less than the output_multiple, this value is ignored and the block can produce like normal. The d_unaligned value is set to the number of items the block is off by. In the next call to general_work, the noutput_items is set to d_unaligned or less until d_unaligned==0. The buffers are now aligned again and the aligned calls can be performed again.