Linux上的POSIX AIO和libaio之间的区别？(Difference between POSIX AIO and libaio on Linux?)

 我好像明白了 
 
 POSIX AIO API在<aio.h>进行了原型设计，并将您的程序与librt（-lrt）链接，而<libaio.h>的libaio API与您的程序链接到libaio（-laio）。 
 
 我不能弄清楚： 
 
 内核处理这些方法之一不同？ 
 
 2. O_DIRECT标志是否强制使用其中的任何一个？ 
 
 如在这篇文章中提到的 ，libaio在使用libaio时没有O_DIRECT工作正常.Okay，理解但是： 
 
 根据R.Love的Linux系统编程书，Linux 只有在使用O_DIRECT打开时才支持常规文件上的aio （我假设是POSIX AIO）。但是，我写了一个小程序（使用aio.h，与-lrt链接）调用在没有O_DIRECT标志的情况下打开的文件中的aio_write无问题。 

What I seem to understand:
 
POSIX AIO APIs are prototyped in <aio.h> and you link your program with librt(-lrt), while the libaio APIs in <libaio.h> and your program is linked with libaio (-laio).
 
What I can't figure out:
 
1.Does the kernel handle the either of these methods differently?
 
2.Is the O_DIRECT flag mandatory for using either of them?
 
As mentioned in this post, libaio works fine without O_DIRECT when using libaio.Okay,understood but:
 
According to R.Love's Linux System Programming book, Linux supports aio (which I assume is POSIX AIO) on regular files only if opened with O_DIRECT.But a small program that I wrote (using aio.h,linked with -lrt) that calls aio_write on a file opened without the O_DIRECT flag works without issues.

原文：https://stackoverflow.com/questions/8768083