On Jan 18, 2012, at 2:27 PM, Ken Thomases wrote: > On Jan 18, 2012, at 3:13 PM, Keary Suska wrote: > >> Any special handling of NSTask aside, Mac OS X uses Unix-based process >> control which closes all child processes when the parent is closed. > > No, that's not true. Where did you get that?
It has likely, as you point out, come from the entirely wrong orifice. I suspect I am confusing tis with system() and popen() calls, which I think have a dependency on the parent process' life, but I could be wrong about that too. > Processes with a controlling terminal get a SIGHUP when that terminal is > closed, and that will kill a naive process, but that wouldn't apply to > subprocesses of GUI apps. Other than that, child processes are independent > of their parent process. > >> Since your sub-program is Java you may be able to detach the child process. > > This doesn't make sense to me. What does being Java have to do with anything? I meant as opposed to a Cocoa-based app. The Java runtime, AFAIK, does not have the same restrictions. >> This is usually accomplished by the sub-program by executing a low-level >> fork(). It may need to be followed by an exec() to fully detach the process. > > Fork() creates the child subprocess as a near duplicate of the parent. > Exec() replaces the process's image with a new one. This is the standard > means of creating a subprocess running a new program, but doesn't > particularly "detach" an already-existing subprocess from its parent > (whatever that might mean). Again, this might be my mistaking daemonizing pipe-to-subprocess, but I could be wrong about that too. >> Note that you can't do this with Cocoa/Objective-C (at least Apple says you >> shouldn't…) > > You can fork() and exec() just fine. What you can't do is fork(), _not_ call > exec(), and then do anything other than call POSIX async-cancel-safe APIs. > That includes using high-level frameworks like Cocoa, Core Foundation, or the > like. This might also be where I recalled the necessity of fork-exec, but it has been some time since I wandered down that rabbit hole.. Sorry for the noise... Keary Suska Esoteritech, Inc. "Demystifying technology for your home or business" _______________________________________________ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
