Building documentation in parallel

[John W. Eaton]

On 29-Aug-2012, John W. Eaton wrote:

| On 29-Aug-2012, Rik wrote:
| 
| | I checked in a changeset that I think solves the parallel build problem
| | completely (http://hg.savannah.gnu.org/hgweb/octave/rev/87f337783d95). 
| | There was a problem with the last attempt in that multiple directories were
| | being created.  Because the name of each directory had the process ID in
| | it, the directory name was unique and Tex could not find the cached
| | results.  Thus, every build was a new build which takes about 4X the time
| | of a cached build.  I renamed the directory for intermediate results to be
| | a fixed name (t2d_cache) and added a local clean rule to remove it if you
| | type 'make clean'.  I extended this change to the other doc directories as
| | well.
| 
| Previously, I used different directories for texi2dvi and texi2pdf.
| Does that matter?  Is there a possibility for collision if the cache
| directories are the same for both and they happen to run at the same
| time?

Oh, I see that texi2dvi is creating separate subdirectories for pdf
and dvi, so I guess there is no problem with having a single cache
directory.

jwe