Thanks a lot for the answer. I will change vfork() with fork(). An another question: in the man page of vfork() it is mentionned that the fork() function has to use _exit(0) too when something wrong with the execve() happens! but in a thread context of my program, the use of _exit() may not be best practice. Is the child a real process or because of the thread context a part of the parent process, so a new thread. In this case a pthread_exit() may be a better solution. Is that point a view complety wrong ?
Currently, is some indeterminate case, a part of my program freeze just after the vfork(). So, I try to understand what may cause the calling thread of vfork() to freeze ... Thanks a lot! On Fri, 28 Nov 2003, Terry Lambert wrote: > Date: Fri, 28 Nov 2003 04:46:31 -0800 > From: Terry Lambert <[EMAIL PROTECTED]> > To: rmkml <[EMAIL PROTECTED]> > Cc: [EMAIL PROTECTED] > Subject: Re: question about _exit() function > > rmkml wrote: > > is the _exit() function safe for a thread ? > > my program use vfork() and then execve in a thread context. > > The documentation mentions that the process has to call _exit() in case > > of failure. > > But this _exit() is really safe for the parent thread ? > > The behaviour is undefined in the failure case, but only if you > have stablishd a pthread_atfork() handler that does anything in > the child. > > In general, the more correct approach is to use posix_spawn(), but > FreeBSD doesn't support posix_spawn() (funny; this has come up now > twice in within 60 messages of each other, while ther was a very > long time when it was not pertinent at all...). > > POSIX also sriously discourages the use of vfork(), and recommends > fork() instead, for threaded programs. > > Note that the fork() only *ever* creates a single thread, so it > will only replicate the currently running thread and its address > space, rather than all currently running threads in the parent. > > You said in another message that this is on 4.8. I think that the > behaviour will not be quite what you expect, in that case, and that > it'll be better in -current, but might still not be what you expect > there, either (depends on what you are expecting). See also: > > http://www.opengroup.org/onlinepubs/007904975/functions/fork.html > > -- Terry > _______________________________________________ [EMAIL PROTECTED] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-hackers To unsubscribe, send any mail to "[EMAIL PROTECTED]"
