# Poplar Prefetching Callbacks Example The example program `prefetch.cpp` defines a poplar program that runs multiple times. The program consists on a repeated sequence: Copy from input stream to tensor. Modify tensor value Copy tensor to output stream. The input stream is connected to a prefetch-able callback and all necessary engine options are set so that the prefetch function is used. All callback functions print a message to standard output to see what is going on. ## File structure * `prefetch.cpp` The main Poplar code example. * `Makefile` A simple Makefile for building the example. * `required_apt_packages.txt` A requirements file for this example. * `test_prefetch.py` The testing script for this example. * `requirements.txt` A requirements file to run testing. * `README.md` This file. ## How to use this example 1) Prepare the environment. Install the Poplar SDK following the instructions in the Getting Started guide for your IPU system. Make sure to source the `enable.sh` script for Poplar. The example also uses boost::program_options. You can install boost via your package manager. 2) Build and run the example. ``` make ./prefetch --help ```