cvs commit: src/usr.bin/make job.c job.h main.c make.c

[Maxim Sobolev]

Great job! However I wonder if use of pipe(2) would be better way, which 
will not leave any traces behind it in the case when all makes die in a 
way that prevents them from taking clean up actions (e.g. kill -9).

-Maxim

Poul-Henning Kamp wrote:
> phk         2004-11-12 08:58:07 UTC
> 
>   FreeBSD src repository
> 
>   Modified files:
>     usr.bin/make         job.c job.h main.c make.c 
>   Log:
>   Add code to enforce the paralleism count (-j N) for the entire tree
>   of submakes spawned during processing.
>   
>   We create a fifo and stuff one character into it for each job we are
>   allowed to run.  The name of the fifo is passed to child processes
>   in the MAKE_JOBS_FIFO environment variable.
>   
>   A make which finds this variable on startup will open the fifo and
>   only spawn jobs when it managed to read a token from the fifo.
>   When the job completes a token is writen back to the fifo.
>   
>   Slave make processes get one token for free: the one their parent
>   make got in order to run them.  This makes the make processes
>   themselves invisible in the process counts.
>   
>   The net effect is that "make -j 12 -s buildworld" will start at
>   most 12 jobs at the same time, instead of as previously up to
>   65 jobs would get started.
>   
>   Revision  Changes    Path
>   1.57      +114 -28   src/usr.bin/make/job.c
>   1.26      +1 -1      src/usr.bin/make/job.h
>   1.96      +2 -0      src/usr.bin/make/main.c
>   1.25      +2 -2      src/usr.bin/make/make.c
> 
> 
>