[Openais] defect 1178

[Fabien THOMAS]

>
> What condition are you trying to protect from?
>
Today it is more a all in one test application to better known the API.

> Checkpoint writes of one section are atomic.  Unfortunately checkpoint
> writes of multiple sections are not atomic in violation of the ais  
> spec
> and to my general dislike.
>
While looking at the code it seems that each iovector is written by  
the lib without any relationship ?
How do you garantee that between two iovec lib write aisexec is not  
called to write the same checkpoint ?

> If someone attempts to read a checkpoint section while you are writing
> the checkpoint they will either a) get old data or b) get new data but
> not c) get a mix of data
>

Fabien