https://en.wikipedia.org/wiki/Coroutine
Coroutines are computer program components that generalize subroutines for non-preemptive multitasking, by allowing execution to be suspended and resumed. Coroutines are well-suited for implementing familiar program components such as cooperative tasks, exceptions, event loops, iterators, infinite lists and pipes.
According to Donald Knuth, Melvin Conway coined the term coroutine in 1958 when he applied it to construction of an assembly program.[1] The first published explanation of the coroutine appeared later, in 1963.[2]
协程是计算机程序的一类组件，推广了协作式多任务的子程序，允许执行被挂起与被恢复。相对子例程而言，协程更为一般和灵活，但在实践中使用没有子例程那样广泛。协程源自Simula和Modula-2语言，但也有其他语言支持。协程更适合于用来实现彼此熟悉的程序组件，如协作式多任务、异常处理、事件循环、迭代器、无限列表和管道。
根据高德纳的说法, 马尔文·康威于1958年发明了术语coroutine并用于构建汇编程序。[1][2] 协程最初在1963年被提出。[2]
Implementations for C#
- MindTouch Dream - The MindTouch Dream REST framework provides an implementation of coroutines based on the C# 2.0 iterator pattern
- Caliburn - The Caliburn screen patterns framework for WPF uses C# 2.0 iterators to ease UI programming, particularly in asynchronous scenarios.
- Power Threading Library - The Power Threading Library by Jeffrey Richter implements an AsyncEnumerator that provides simplified Asynchronous Programming Model using iterator-based coroutines.
- The Unity game engine implements coroutines.
- Servelat Pieces - The Servelat Pieces project by Yevhen Bobrov provides transparent asynchrony for Silverlight WCF services and ability to asynchronously call any synchronous method. The implementation is based on Caliburn's Coroutines iterator and C# iterator blocks.
- [9] - The .NET 2.0+ Framework now provides semi-coroutine (generator) functionality through the iterator pattern and yield keyword.
C# 5.0 includes await syntax support.