arch/.unmaintained/dummy/disable.c

   1 /*
   2     Copyright © 1995-2001, The AROS Development Team. All rights reserved.
   3     $Id$
   4
   5     Desc: Exec function Disable
   6     Lang: english
   7 */
   8 #define timeval sys_timeval
   9 #include <signal.h>
  10 #undef timeval
  11 #include <exec/execbase.h>
  12
  13 void disable (void);
  14
  15 /******************************************************************************
  16
  17     NAME */
  18 #include <proto/exec.h>
  19
  20         AROS_LH0(void, Disable,
  21
  22 /*  LOCATION */
  23         struct ExecBase *, SysBase, 20, Exec)
  24
  25 /*  FUNCTION
  26         This function disables the delivery of all interrupts until a
  27         matching call to Enable() is done. This implies a Forbid(). Since
  28         the system needs the regular delivery of all interrupts it is
  29         forbidden to disable them for longer than ~250 microseconds.
  30
  31         THIS CALL IS VERY DANGEROUS!!!
  32
  33         Do not use it without thinking very well about it or better do not
  34         use it at all. Most of the time you can live without it by using
  35         semaphores or similar.
  36
  37         Calls to Disable() nest, i.e. for each call to Disable() you need
  38         one call to Enable().
  39
  40
  41     INPUTS
  42         None.
  43
  44     RESULT
  45         None.
  46
  47     NOTES
  48         You should not use this function as a cheap way to avoid
  49         using a semaphore.
  50
  51         If you can, use Forbid() instead.
  52
  53         This function preserves all registers.
  54
  55         This function may be used from interrupts to disable all higher
  56         priority interrupts. Lower priority interrupts are disabled anyway.
  57
  58         To prevent deadlocks calling Wait() in disabled state breaks the
  59         disable - thus interrupts and taskswitches may happen again.
  60
  61     EXAMPLE
  62
  63     BUGS
  64
  65     SEE ALSO
  66         Enable(), Forbid(), Permit(), Wait()
  67
  68     INTERNALS
  69
  70     HISTORY
  71
  72 ******************************************************************************/
  73 {
  74     disable ();
  75
  76     SysBase->IDNestCnt ++;
  77 } /* Disable */
  78
  79 void disable (void)
  80 {
  81     sigset_t set;
  82
  83     sigfillset (&set);
  84
  85     sigprocmask (SIG_BLOCK, &set, NULL);
  86 } /* disable */