It is with much excitement (and after only 4 RCs!!) that we release the next step forward for GNU Radio - 3.10.0.0!
Not only does this release bring in some extremely useful new modules (gr-iio, gr-pdu, and arguably gr-soapy thought that thankfully made it also into recent 3.9 maintenance releases), but also sets a path forward for using GNU Radio in heterogeneous compute environments by providing "custom buffers" for more efficiently interacting with accelerators (GPUS, FPGAs, TPUs, etc.).
We have been fortunate this year to have extremely active backporting and consistent maintenance releases from co-maintainter Jeff Long - so many of the fixes and smaller features (and larger ones) have already seen the light of day in the 3.9.x.x and even 3.8.x.x releases. Here are some highlights of the 3.10 release:
gr-pduPDUs (protocol data units) in GNU Radio are a special type of PMT that have a dictionary and a uniform vector type representing a burst of data with some metadata. Up to this point, support of pdus has been scattered throughout the codebase with minimal supporting the way of handling this type of data consistently. Fortunately, Jacob Gilbert has been able to upstream much of the amazing work from himself and the team at Sandia National Labs which brings in-tree a suite of tools for manipulating these data objects (see
https://github.com/sandialabs/gr-pdu_utils). Also, many of the previous PDU processing blocks that existed in other in-tree modules have been migrated to this module, so there has been some block re-arrangement. Please see
https://www.youtube.com/watch?v=bT60hVVte48 for more detailed information
gr-iioIIO is the industrial I/O framework that provides an industry standard method for communicating with a wide-range of devices. Analog Devices has supported out of tree a gr-iio module that brings this capability into GNU Radio and now upstreamed this module so support for devices like the PlutoSDR are available out of the box. Special thanks here to Adam Horden, Dave Winter, Volker Shroer for bringing this in-tree and working through many of the complexities.
Please see
https://www.youtube.com/watch?v=2gKbollW6wg for a more technical description of IIO and gr-iio.
Custom Buffers SupportNOTE: this is an advanced "experimental" feature that if not actively employed will not affect normal GNU Radio usage.
David Sorber from Black Lynx has introduced a feature that enables streamlined data movement between GNU Radio blocks and hardware accelerators. By creating a "custom buffer" class (or using one that is provided by someone else), blocks can be made to abstract the data movement behind the scenes so that when the `work` function is reached, data already exists in the device memory.
Let me give a quick example - previously if you wanted to write a GPU accelerated block with CUDA, you would have to get into the work function, move the data from the GNU Radio circular buffers to GPU device memory, execute the CUDA kernels, then move the data back to GR buffers. Now that data movement is done behind the scenes if the block is set up right so that when the work function is hit, the data is in GPU device memory and will get transferred back to CPU memory behind the scenes as well. This allows back to back HW accelerated blocks to not have to ingress/egress in and out of GR memory unnecessarily. Also, the single mapped buffer abstraction brings huge performance benefits as can be seen here:
https://www.youtube.com/watch?v=VO1zMXowezg for a much better description
For examples of this in action, please see the gr-cuda repository here:
https://github.com/gnuradio/gr-cuda - which contains the CUDA custom buffers (that can be re-used in your OOT) and some example blocks.
Logging InfrastructureLog4CPP has previously been our logging backend library, but has become a troublesome dependency. A huge thanks to Marcus Müller for fixing all of this up, replacing Log4CPP with spdlog - a more modern logging library, and also for his ongoing architectural leadership on this project. The move to spdlog also opens up the door for more modern logging statements that don't rely on Boost.format, and libfmt (which is now also a dependency) can be used for general string manipulation as well. All the previous methods and macros still exist (except for the log4cpp specific ones), but there is now new capability to log in a more convenient way using the libfmt statements.
Previous: GR_LOG_INFO(this->d_logger, boost::format("this happened: %d") % code)
New: this->d_logger->info("this happened {:d}", code)
Travis F. Collins
One minor note - the master branch will be renamed early next week as "main" to align with the github defaults and the direction that most projects have moved. This should be minimally if at all disruptive.