pthreads/pthread_atfork.3

   1 .\" Copyright (c) 2004 Apple Computer, Inc.
   2 .\"
   3 .Dd August 12, 2004
   4 .Dt PTHREAD_ATFORK 3
   5 .Os
   6 .Sh NAME
   7 .Nm pthread_atfork
   8 .Nd register handlers to be called before and after
   9 .Fn fork
  10 .Sh SYNOPSIS
  11 .Fd #include <pthread.h>
  12 .Ft int
  13 .Fn pthread_atfork "void (*prepare)(void)" "void (*parent)(void)" "void (*child)(void)"
  14 .Sh DESCRIPTION
  15 The
  16 .Fn pthread_atfork
  17 function is used to register functions to be called before and after
  18 .Fn fork
  19 The
  20 .Fa prepare
  21 handler is called before
  22 .Fn fork ,
  23 while the
  24 .Fa parent
  25 and
  26 .Fa child
  27 handlers are called after
  28 .Fn fork
  29 in the parent and child process, respectively.
  30 .Fa prepare
  31 handlers are called in reverse order of their registration, while
  32 .Fa parent
  33 and
  34 .Fa child
  35 handlers are called in the order in which they were registered. Any of the handlers may
  36 be NULL.
  37 .Pp
  38 Remember: only async-cancel-safe functions are allowed on the child side of
  39 .Fn fork
  40 .Sh RETURN VALUES
  41 If successful, the
  42 .Fn pthread_atfork
  43 function will return zero; otherwise an error number will be returned to
  44 indicate the error.
  45 .Sh ERRORS
  46 .Fn pthread_atfork
  47 will fail if:
  48 .Bl -tag -width Er
  49 .It Bq Er ENOMEM
  50 The system lacked the necessary resources to add another handler to the list.
  51 .El
  52 .Sh SEE ALSO
  53 .Xr fork 2
  54 .Sh STANDARDS
  55 .Fn pthread_atfork
  56 conforms to
  57 .St -p1003.1-96 .