Re: serial vs parallel for ar

[David Boyce]

At 09:45 AM 5/18/2006, Alexey Neyman wrote:
> Just to add. I encountered similar problem when I attempted to use
> parallel make for a project that used the following rule:
>
> (%.o): %.c
>         $(CC) -c -o $% %<
>         $(AR) cru $@ $%
>         $(RM) $%
>
> Suspecting somewhat similar in Mr.Patton's project.

I have not read this thread in detail, so apologies if this is an 
answer to the wrong question. But there's a longstanding issue with 
ar and parallelism due to the fact that many ar programs create a 
statically named temp file in the current directory. It has to do 
with generating the symbol table, during the course of which ar 
creates a file called "__SYMDEF" (or something like that, this is 
from memory). This is not just a problem for parallel updates to the 
same archive but also for building multiple libraries in the same 
directory. The workaround is a build script which creates and cds 
into a temp directory, something like

        (mkdir ar.$$$$.d && cd ar.$$$$.d && [ar command here] && cd 
.. && rmdir ar.$$$$.d)

If this isn't your current problem it may well be your next one.

-David Boyce