release-3-4-0

# Release 3.4.0 (2022/05/23)

Download
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System Requirements
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Release Summary
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New Features
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Taskflow Core
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cudaFlow
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syclFlow
release-3-4-0_1release-3-4-0_syclflow
Utilities
release-3-4-0_1release-3-4-0_utilities
Bug Fixes
release-3-4-0_1release-3-4-0_bug_fixes
Breaking Changes
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Deprecated and Removed Items
release-3-4-0_1release-3-4-0_deprecated_items
Documentation
release-3-4-0_1release-3-4-0_documentation
Miscellaneous Items
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Taskflow 3.4.0 is the 5th release in the 3.x line! This release includes several new changes, such as pipeline parallelism, deadlock-free execution methods, documentation, examples, and unit tests.

# Download

Taskflow 3.4.0 can be downloaded from here.

# System Requirements

To use Taskflow v3.4.0, you need a compiler that supports C++17:

- GNU C++ Compiler at least v8.4 with -std=c++17

- Clang C++ Compiler at least v6.0 with -std=c++17

- Microsoft Visual Studio at least v19.27 with /std:c++17

- AppleClang Xcode Version at least v12.0 with -std=c++17

- Nvidia CUDA Toolkit and Compiler (nvcc) at least v11.1 with -std=c++17

- Intel C++ Compiler at least v19.0.1 with -std=c++17

- Intel DPC++ Clang Compiler at least v13.0.0 with -std=c++17 and SYCL20

Taskflow works on Linux, Windows, and Mac OS X.

# Release Summary

This release enhances our task-parallel pipeline programming model and executor methods, supplied with several new examples and unit tests.

# New Features

## Taskflow Core

- Improved the pipeline performance using vertical stack optimization

- Added tf::ScalablePipeline to allow programming variable lengths of pipes

- Added tf::Runtime::run_and_wait to allow spawning a subflow

- Added tf::Executor::run_and_wait to allow running taskflows from a worker

- Added an example of attaching data to a task (examples/attach_data.cpp)

- Added an example of text processing pipeline (examples/parallel_text_pipeline.cpp)

- Added an example of graph processing pipeline (examples/parallel_graph_pipeline.cpp)

- Added an example of taskflow processing pipeline (examples/parallel_taskflow_pipeline.cpp)

- Added an example of running a task graph from a worker (examples/run_and_wait.cpp)

## cudaFlow

- Added tf::cudaStream as a move-only, RAII-styled wrapper over a native CUDA stream

- Added tf::cudaEvent as a move-only, RAII-styled wrapper over a native CUDA event

## syclFlow

There is no update on syclFlow in this release.

## Utilities

- Removed serializer to improve compilation speed

# Bug Fixes

- Fixed the compilation error due to non-portable include of `immintrin.h` (#371)

- Fixed the compilation error due to using old version of doctest (#372)

- Fixed the infinite loop bug due to unexpected share states in pipeline (#402)

If you encounter any potential bugs, please submit an issue at issue tracker.

# Breaking Changes

- Replaced tf::Runtime::run with tf::Runtime::run_and_wait to comply with tf::Executor::run_and_wait

# Deprecated and Removed Items

There are no deprecated items in this release.

# Documentation

- Revised Executor

  - Added Execute a Taskflow from an Internal Worker

- Revised Execution Policy

- Revised Task-parallel Pipeline

  - Added Learn More about Taskflow Pipeline

- Revised Learning from Examples

  - Added Text Processing Pipeline

  - Added Graph Processing Pipeline

  - Added Taskflow Processing Pipeline

- Added Task-parallel Scalable Pipeline

# Miscellaneous Items

We have published Taskflow in the following venues:

- Dian-Lun Lin and Tsung-Wei Huang, "Accelerating Large Sparse Neural Network Inference using GPU Task Graph Parallelism," IEEE Transactions on Parallel and Distributed Systems (TPDS), 2022

- Cheng-Hsiang Chiu and Tsung-Wei Huang, "Composing Pipeline Parallelism using Control Taskflow Graph," ACM International Symposium on High-Performance Parallel and Distributed Computing (HPDC), Minneapolis, Minnesota, 2022

- Cheng-Hsiang Chiu and Tsung-Wei Huang, "Efficient Timing Propagation with Simultaneous Structural and Pipeline Parallelisms," ACM/IEEE Design Automation Conference (DAC), San Francisco, CA, 2022

Please do not hesitate to contact Dr. Tsung-Wei Huang if you intend to collaborate with us on using Taskflow in your scientific computing projects.