diff options
| -rw-r--r-- | gnuradio-runtime/include/gnuradio/block.h | 22 |
1 files changed, 17 insertions, 5 deletions
diff --git a/gnuradio-runtime/include/gnuradio/block.h b/gnuradio-runtime/include/gnuradio/block.h index 3e74dd8c93..1b6f66d45b 100644 --- a/gnuradio-runtime/include/gnuradio/block.h +++ b/gnuradio-runtime/include/gnuradio/block.h @@ -44,9 +44,14 @@ namespace gr { * 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. + * Blocks report the number of items consumed on each input in + * general_work(), using consume() or consume_each(). + * + * If the same number of items is produced on each output, the block + * returns that number from general_work(). Otherwise, the block + * calls produce() for each output, then returns + * WORK_CALLED_PRODUCE. The input and output rates are not required + * to be related. * * User derived blocks override two methods, forecast and * general_work, to implement their signal processing @@ -160,8 +165,15 @@ namespace gr { * \param input_items vector of pointers to the input items, one entry per input stream * \param 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 + * \returns number of items actually written to each output stream + * or WORK_CALLED_PRODUCE or WORK_DONE. It is OK to return a + * value less than noutput_items. + * + * WORK_CALLED_PRODUCE is used where not all outputs produce the + * same number of items. general_work must call produce() for each + * output to indicate the numer of items actually produced. + * + * WORK_DONE indicates that no more data will be produced by this block. * * general_work must call consume or consume_each to indicate how * many items were consumed on each input stream. |