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Diffstat (limited to 'linuxthreads/man/pthread_atfork.man')
-rw-r--r-- | linuxthreads/man/pthread_atfork.man | 53 |
1 files changed, 53 insertions, 0 deletions
diff --git a/linuxthreads/man/pthread_atfork.man b/linuxthreads/man/pthread_atfork.man new file mode 100644 index 0000000..b682bed --- /dev/null +++ b/linuxthreads/man/pthread_atfork.man @@ -0,0 +1,53 @@ +.TH PTHREAD_ATFORK 3 LinuxThreads + +.SH NAME +pthread_atfork \- register handlers to be called at fork(2) time + +.SH SYNOPSIS +#include <pthread.h> + +int pthread_atfork(void (*prepare)(void), void (*parent)(void), void (*child)(void)); + +.SH DESCRIPTION + +!pthread_atfork! registers handler functions to be called just before +and just after a new process is created with !fork!(2). The |prepare| +handler will be called from the parent process, just before the new +process is created. The |parent| handler will be called from the parent +process, just before !fork!(2) returns. The |child| handler will be +called from the child process, just before !fork!(2) returns. + +One or several of the three handlers |prepare|, |parent| and |child| +can be given as !NULL!, meaning that no handler needs to be called at +the corresponding point. + +!pthread_atfork! can be called several times to install several sets +of handlers. At !fork!(2) time, the |prepare| handlers are called in +LIFO order (last added with !pthread_atfork!, first called before !fork!), +while the |parent| and |child| handlers are called in FIFO order +(first added, first called). + +To understand the purpose of !pthread_atfork!, recall that !fork!(2) +duplicates the whole memory space, including mutexes in their current +locking state, but only the calling thread: other threads are not +running in the child process. The mutexes are not usable after the +!fork! and must be initialized with |pthread_mutex_init| in the child +process. This is a limitation of the current implementation and might +or might not be present in future versions. + +.SH "RETURN VALUE" + +!pthread_atfork! returns 0 on success and a non-zero error code on error. + +.SH ERRORS +.TP +!ENOMEM! +insufficient memory available to register the handlers. + +.SH AUTHOR +Xavier Leroy <Xavier.Leroy@inria.fr> + +.SH "SEE ALSO" +!fork!(2), +!pthread_mutex_lock!(3), +!pthread_mutex_unlock!(3). |