ios多线程攻略之GCD

ios多线程攻略之GCD(中文3800字,英文3300字)
GCD介绍(一):基本概念和Dispatch Queue
什么是GCD？
Grand Central Dispatch或者GCD，是一套低层API，提供了一种新的方法来进行并发程序编写。从基本功能上讲，GCD有点像NSOperationQueue，他们都允许程序将任务切分为多个单一任务然后提交至工作队列来并发地或者串行地执行。GCD比之NSOpertionQueue更底层更高效，并且它不是Cocoa框架的一部分。
GCD的API很大程度上基于block，当然，GCD也可以脱离block来使用，比如使用传统c机制提供函数指针和上下文指针。实践证明，当配合block使用时，GCD非常简单易用且能发挥其最大能力。

The GCD OF IOS MULTITHREADING
Introduce to Grand Central Dispatch,Part I: Basics and Dispatch Queues
What Is It?
Grand Central Dispatch, or GCD for short, is a low level API which introduces a new way to perform concurrent programming. For basic functionality it's a bit like NSOperationQueue, in that it allows a program's work to be divided up into individual tasks which are then submitted to work queues to run concurrently or serially. It's lower level and higher performance than NSOperationQueue, and is not part of the Cocoa frameworks.
GCD's API is heavily based around blocks, While GCD can be used without blocks, by using the traditional C mechanism of providing a function pointer and a context pointer, it's vastly easier to use and ultimately more capable, from a practical standpoint, when used with blocks.