compiler/clib/sharecontextwithchild.c

   1 /*
   2     Copyright © 2009-2012, The AROS Development Team. All rights reserved.
   3     $Id$
   4
   5     AROS function sharecontextwithchild().
   6 */
   7
   8 #include "__arosc_privdata.h"
   9 #include <aros/debug.h>
  10
  11 /*****************************************************************************
  12
  13     NAME */
  14 #include <unistd.h>
  15
  16         void sharecontextwithchild (
  17
  18 /*  SYNOPSIS */
  19         int share)
  20
  21 /*  FUNCTION
  22         Controls sharing parent arosc context with child processes.
  23         Must be called by parent process.
  24
  25     INPUTS
  26         share - TRUE/FALSE - should parent share context with children
  27
  28     RESULT
  29
  30     NOTES
  31         By calling this function the user of arosc.library controls how
  32         new child processes use parent's arosc.library context.
  33
  34         When sharing is enabled, a child process will never create its
  35         own arosc.library context and will alway use parent's context.
  36
  37         If you have a parent and child process allocating/dealocating
  38         (malloc/free) memory for the same pointer, you must use this
  39         function so that the memory will always be allocated in the
  40         same arosc.libray context. Failure to do so will result with
  41         GURU during free.
  42
  43         Things to be aware off:
  44         - this function is dangeruos - you as a programmer must take care
  45         of thread synchronization
  46         - a child process cannot have life span longer than a parent process
  47         - a child process may not call vfork or exec* functions - if such
  48         feature is required, the vfork and exec* functions need to be
  49         modified to work with flag set by this function
  50         - once enabled, the sharing can be disabled at any time - when
  51         the sharing is disabled, all child processes will acquire their
  52         own arosc contexts when such need arises.
  53
  54     EXAMPLE
  55
  56     BUGS
  57
  58     SEE ALSO
  59
  60     INTERNALS
  61
  62 ******************************************************************************/
  63 {
  64     struct aroscbase *aroscbase = __GM_GetBase();
  65
  66     if (aroscbase)
  67     {
  68         if (share)
  69             aroscbase->acb_flags |= SHARE_ACPD_WITH_CHILD;
  70         else
  71             aroscbase->acb_flags &= ~SHARE_ACPD_WITH_CHILD;
  72     }
  73 } /* sharecontextwithchild() */
  74