K. Noel Belcourt 2f5d59569d Another patch to fix the -lx timeout code. Some actions spawn ...

sub-processes after bjam forks a new process (for example, after
g++ is forked by bjam, g++ then forks sub-processes like cc1plus).
The timeout code would kill the g++ process, but might not kill
the subprocesses spawned by g++.

I fixed this problem by making the bjam fork'ed process (g++) a 
session leader by calling setsid() before calling exec.  The setsid 
call, in essence, gives all child processes a parent process id 
(ppid) of the g++ process id.  This guarantees that killing g++ 
will kill all child processes spawned by g++ as well.

One last comment on the maximum process time before a process is actually
killed.  The worst case process elapsed time is 2x seconds if -lx is
given.  The reason is that a process might be one second away from being
killed and, if there's no other signal activity, the select function will
wait x seconds before timing out and killing any active processes.  So
if you say -lx and monitor a build known to have lengthy processes, you 
may see a process with up to 2x seconds of time before it is killed.



[SVN r39467]

2007-09-21 22:38:17 +00:00

..

jam

Another patch to fix the -lx timeout code. Some actions spawn

2007-09-21 22:38:17 +00:00