https://en.wikipedia.org/wiki/Subroutine
In computer programming, a subroutine is a sequence of program instructions that perform a specific task, packaged as a unit. This unit can then be used in programs wherever that particular task should be performed.
Subprograms may be defined within programs, or separately in libraries that can be used by multiple programs. In different programming languages, a subroutine may be called a procedure, a function, a routine, a method, or a subprogram. The generic term callable unit is sometimes used.[1]
Subroutines are special cases of ... coroutines.
https://en.wikipedia.org/wiki/Coroutine
Coroutines are computer-program components that generalize subroutines for non-preemptive multitasking, by allowing multiple entry points for suspending and resuming execution at certain locations. 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]
Routine Subroutine Coroutine 子程序 协程
原文：http://www.cnblogs.com/yuanjiangw/p/7772302.html