Release 3.8.0 (2024/10/02)

Table of Contents

• Release Summary
• Download
• System Requirements
• New Features
  • Taskflow Core
  • Utilities
• Bug Fixes
• Breaking Changes
• Documentation
• Miscellaneous Items

Release Summary

This releases (1) enhances the scheduling performance through C++20 atomic notification and a bounded queue strategy and (2) revised the semaphore model for better runtime control.

Download

Taskflow 3.8.0 can be downloaded from here.

System Requirements

To use Taskflow v3.8.0, 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

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

Attention

Although Taskflow supports primarily C++17, you can enable C++20 compilation through -std=c++20 to achieve better performance due to new C++20 features.

New Features

Taskflow Core

• Enhanced the core scheduling algorithm using a new bounded queue strategy
• Enhanced the core scheduling performance using C++20 atomic notification

# compile your taskflow program with C++20 enabled
~$ g++ -std=c++20 my_taskflow.cpp 

• Revised the semaphore programming model for better runtime control through tf::Runtime

tf::Executor executor(8);   // create an executor of 8 workers
tf::Taskflow taskflow;
tf::Semaphore semaphore(1); // create a semaphore with initial count 1
for(size_t i=0; i<1000; i++) {
  taskflow.emplace([&](tf::Runtime& rt){ 
    rt.acquire(semaphore);
    std::cout << "critical section here (one worker here only)\n"; 
    critical_section();
    rt.release(semaphore);
  });
}
executor.run(taskflow).wait();

• Enhanced async-tasking performance through TLS
• Added async-task benchmark
• Added non-blocking notifier and atomic notifier modules
• Added tf::BoundedTaskQueue and tf::UnboundedTaskQueue
• Added tf::Freelist module to replace the centralized overflow queue
• Removed the redundant exception handling in object pool

Utilities

Bug Fixes

• Fixed the compilation error for not finding the C++ atomic library
• Fixed the missing tf::Runtime in asynchronous tasking
• Fixed the non-heterogeneity of tf::Taskflow::for_each_index
• Fixed the bug of UUID unit test in a multithreaded environment

Breaking Changes

• Removed the support of object pool by default
• Removed the support of prioritized tasking due to inconsistency with work stealing

Documentation

• Revised Limit the Maximum Concurrency
• Removed Prioritized Tasking
• Fixed typos in multiple pages

Miscellaneous Items

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.