3 ms·

The pthread_atfork() function shall declare fork handlers to be called before and after fork(), in the context of the thread that called fork(). The prepare for

The pthread_atfork() function shall declare fork handlers to be called before and after fork(), in the context of the thread that called fork(). The prepare fork handler shall be called before fork() processing commences. The parent fork handle shall be called after fork() processing completes in the parent process. The child fork handler shall be called after fork() processing completes in the child process. If no handling is desired at one or more of these three points, the corresponding fork handler address(es) may be set to NULL. The order of calls to pthread_atfork() is significant. The parent and child fork handlers shall be called in the order in which they were established by calls to pthread_atfork(). The prepare fork handlers shall be called in the opposite order. I'm not sure if that's the best approach, but it's an attempt at least.

pjmlp 12y ago
I just had a look at IEEE Std 1003.1, 2013 Edition for pthread_atfork(). It has a few corner cases across POSIX systems. I wouldn't bet it works 100% the same way in all UNIXes.
- djcapelis 12y ago
  Of course it doesn't, very few things do. Cross platform is hard, but that doesn't mean you don't use features.
  - pjmlp 12y ago
    Of course, but sometimes it is a huge pain. I used to do cross platform across Aix, HP-UX, Solaris, GNU/Linux, FreeBSD and Windows NT/2000 back in the .COM days.
    - wahern 12y ago
      It's much easier in 2014 than it was in 2004. POSIX has evolved, and POSIX conformance has substantially improved. Most systems are, in practice, nearly 100% conformant to POSIX-2001. Excepting Windows, I rarely run into difficult portability problems except when I deliberately use non-POSIX functionality or newer POSIX functionality. I target Linux, OS X, OpenBSD, NetBSD, FreeBSD, Solaris, and AIX. The biggest laggard was OpenBSD, particularly wrt to threading, signal handling, and real-time extensions. But in the past couple of years that's been substantially addressed. One of my biggest headaches now is OS X. They appear to have stopped trying to track POSIX, so while everybody else is busily implementing POSIX-2004, POSIX-2008, and tentative POSIX features, OS X is nearly at a stand-still. OS X hasn't fixed any significant conformance issues, adopted real-time extensions, nor adopted any POSIX-2008 features for several years, now.
      - pjmlp 12y ago
        Thanks for the update, however there seems they still a long way to go until most systems reach UNIX V7 X1201 compliance.

pjmlp 12y ago

I just had a look at IEEE Std 1003.1, 2013 Edition for pthread_atfork(). It has a few corner cases across POSIX systems. I wouldn't bet it works 100% the same way in all UNIXes.

djcapelis 12y ago
Of course it doesn't, very few things do. Cross platform is hard, but that doesn't mean you don't use features.
- pjmlp 12y ago
  Of course, but sometimes it is a huge pain. I used to do cross platform across Aix, HP-UX, Solaris, GNU/Linux, FreeBSD and Windows NT/2000 back in the .COM days.
  - wahern 12y ago
    It's much easier in 2014 than it was in 2004. POSIX has evolved, and POSIX conformance has substantially improved. Most systems are, in practice, nearly 100% conformant to POSIX-2001. Excepting Windows, I rarely run into difficult portability problems except when I deliberately use non-POSIX functionality or newer POSIX functionality. I target Linux, OS X, OpenBSD, NetBSD, FreeBSD, Solaris, and AIX. The biggest laggard was OpenBSD, particularly wrt to threading, signal handling, and real-time extensions. But in the past couple of years that's been substantially addressed. One of my biggest headaches now is OS X. They appear to have stopped trying to track POSIX, so while everybody else is busily implementing POSIX-2004, POSIX-2008, and tentative POSIX features, OS X is nearly at a stand-still. OS X hasn't fixed any significant conformance issues, adopted real-time extensions, nor adopted any POSIX-2008 features for several years, now.
    - pjmlp 12y ago
      Thanks for the update, however there seems they still a long way to go until most systems reach UNIX V7 X1201 compliance.