StreamPU is a Domain Specific Embedded Language (DSEL) for streaming applications. It comes in the form of a C 11 library to link with.

Here are the main features of StreamPU:

• Definition of dataflow components: modules, tasks and sockets
• Elementary modules and tasks implementations
• Multi-threaded runtime with replication and pipeline parallel constructs

This DSEL/library is suitable for SDR systems, audio/video processing and more generally it matches single-rate Synchronous DataFlow (SDF) streaming applications.

Please note that this library was previously named AFF3CT-core as it was first extracted from AFF3CT. Now that it is no longer specific to channel coding and digital communications, the project has been renamed to StreamPU, which is a more meaningful name.

This project uses CMake as the main build system and it provides the following CMake options:

• SPU_COMPILE_STATIC_LIB: Compile the static library (default = ON)
• SPU_COMPILE_SHARED_LIB: Compile the shared library (default = OFF)
• SPU_LINK_HWLOC: Link with the hwloc library (used for threads pinning) (default = OFF)
• SPU_COLORS: Enable the colors in the terminal (default = ON)
• SPU_TESTS: Enable the compilation of the tests (default = ON)
• SPU_STACKTRACE: Print the stack trace when an exception is raised (and link with the cpptrace lib) (default = ON)
• SPU_STACKTRACE_SEGFAULT: Try to print the stack trace when a segfault occurs (and link with the cpptrace lib) (default = OFF)
• SPU_SHOW_DEPRECATED: Print message each time a deprecated function is called (default = OFF)
• SPU_FAST: Remove checks to speedup the code (default = OFF)

Build the library in debug mode:

mkdir build_debug
cd build_debug
cmake ..
cmake --build . -j 4
ctest

Build the library in release mode:

mkdir build_release
cd build_release
cmake .. -DCMAKE_BUILD_TYPE=RelWithDebInfo -DCMAKE_CXX_FLAGS="-Wall -march=native -funroll-loops"
cmake --build . -j 4
ctest

Install the library on the system (/usr/local):

cmake --install .

Install the library in a custom path (/opt/streampu):

cmake --install . --prefix /opt/streampu/

StreamPU exposes two CMake targets:

• spu::spu-static-lib: StreamPU static library, includes and definitions (compiled by default)
• spu::spu-shared-lib: StreamPU shared library, includes and definitions

It is possible to link with StreamPU from a sub-directory or from an installed library. Both methods are described in the next sections.

Let us suppose that we want to produce the my-exe executable that will links with StreamPU and that the StreamPU repository is located at my-exe-root/lib/streampu/. Here is a minimal CMakeLists.txt file to generate it:

cmake_minimum_required(VERSION 3.5)

project(my_project CXX)

# require C  11 compiler ------------------------------------------------------
set(CMAKE_CXX_STANDARD 11)
set(CMAKE_CXX_STANDARD_REQUIRED ON)

# create the `my-exe` executable from `src/main.cpp` --------------------------
add_executable(my-exe ${CMAKE_CURRENT_SOURCE_DIR}/src/main.cpp)

# compile `StreamPU` static lib -----------------------------------------------
option(SPU_TESTS "" OFF) # do NOT compile the tests
add_subdirectory(${CMAKE_CURRENT_SOURCE_DIR}/lib/streampu/)

# `my-exe` links with `StreamPU` static lib -----------------------------------
target_link_libraries(my-exe PUBLIC spu::spu-static-lib)

# `my-exe` finds and links with thread library --------------------------------
set(CMAKE_THREAD_PREFER_PTHREAD ON)
set(THREADS_PREFER_PTHREAD_FLAG ON)
find_package(Threads REQUIRED)
target_link_libraries(my-exe PUBLIC Threads::Threads)

# `my-exe` links with `cpptrace` (`SPU_STACKTRACE=ON`) ------------------------
if(SPU_STACKTRACE OR SPU_STACKTRACE_SEGFAULT)
  target_link_libraries(my-exe PUBLIC cpptrace::cpptrace)
endif()

Let us suppose that we want to produce the my-exe executable that links with StreamPU static library installed on the system. Here is a minimal CMakeLists.txt file to generate it:

cmake_minimum_required(VERSION 3.5)

project(my_project CXX)

# require C  11 compiler ------------------------------------------------------
set(CMAKE_CXX_STANDARD 11)
set(CMAKE_CXX_STANDARD_REQUIRED ON)

# create the `my-exe` executable from `src/main.cpp` --------------------------
add_executable(my-exe ${CMAKE_CURRENT_SOURCE_DIR}/src/main.cpp)

# find and link with thread library -------------------------------------------
set(CMAKE_THREAD_PREFER_PTHREAD ON)
set(THREADS_PREFER_PTHREAD_FLAG ON)
find_package(Threads REQUIRED)
target_link_libraries(my-exe PUBLIC Threads::Threads)

# find and link with `cpptrace` if installed (if not, don't) ------------------
find_package(cpptrace CONFIG 0.4.1)
if (cpptrace_FOUND)
  target_link_libraries(my-exe PUBLIC cpptrace::cpptrace)
endif()

# find and link with `StreamPU` -----------------------------------------------
find_package(StreamPU CONFIG 0.0.0 REQUIRED)
target_link_libraries(my-exe PUBLIC spu::spu-static-lib)

If StreamPU is installed in a specific location (for instance: /opt/streampu), you can help CMake to find it as follow:

cmake .. -DStreamPU_DIR=/opt/streampu/lib/cmake/streampu

Or, if StreamPU has been compiled with the cpptrace library:

cmake .. -DStreamPU_DIR=/opt/streampu/lib/cmake/streampu -Dcpptrace_DIR=/opt/streampu/lib/cmake/cpptrace

• User documentation - [Slides with animations] / [Slides without animation]
  • Slides used to teach StreamPU to Master students in Computer Science at Sorbonne University
  • Contains many illustrative and simple use cases: a good document to start with StreamPU
• Developer documentation
  • Online doc that focuses on how StreamPU is built and works
  • Particularly useful to learn how to modify StreamPU and to contribute

The project is licensed under the MIT license.

The main contributions of this work are described in the following journal article:

• A. Cassagne, R. Tajan, O. Aumage, D. Barthou, C. Leroux and C. Jégo,
  “A DSEL for High Throughput and Low Latency Software-Defined Radio on Multicore CPUs,“
  Wiley Concurrency and Computation: Practice and Experience (CCPE), 2023.
  [Open access article] [Bibtex entry]