sysdeps/unix/sysv/sysv4/bits/sigset.h

   1 /* __sig_atomic_t, __sigset_t, and related definitions.  SVR4 version.
   2    Copyright (C) 1994-1996, 2002 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, write to the Free
  17    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  18    02111-1307 USA.  */
  19
  20 #ifndef _SIGSET_H_types
  21 #define _SIGSET_H_types 1
  22
  23 typedef int __sig_atomic_t;
  24
  25 /* A `sigset_t' has a bit for each signal.  */
  26 typedef struct
  27   {
  28     unsigned long int __sigbits[4];
  29   } __sigset_t;
  30
  31 #endif  /* ! _SIGSET_H_types */
  32
  33 /* We only want to define these functions if <signal.h> was actually
  34    included; otherwise we were included just to define the types.  Since we
  35    are namespace-clean, it wouldn't hurt to define extra macros.  But
  36    trouble can be caused by functions being defined (e.g., any global
  37    register vars declared later will cause compilation errors).  */
  38
  39 #if !defined (_SIGSET_H_fns) && defined (_SIGNAL_H)
  40 #define _SIGSET_H_fns 1
  41
  42 /* Return a mask that includes SIG only.  */
  43 #define __sigmask(sig)  (1 << ((sig) - 1))
  44
  45
  46 /* It's easier to assume 8-bit bytes than to get CHAR_BIT.  */
  47 #define __NSSBITS       (sizeof (unsigned long int) * 8)
  48 #define __SSELT(s)      ((s) / __NSSBITS)
  49 #define __SSMASK(s)     (1 << ((s) % __NSSBITS))
  50
  51 #ifdef __USE_EXTERN_INLINES
  52 # ifndef _EXTERN_INLINE
  53 #  define _EXTERN_INLINE        extern __inline
  54 # endif
  55
  56 _EXTERN_INLINE int
  57 __sigemptyset (__sigset_t *__set)
  58 {
  59   __set->__sigbits[0] = __set->__sigbits[1] =
  60     __set->__sigbits[2] = __set->__sigbits[3] = 0L;
  61   return 0;
  62 }
  63
  64 _EXTERN_INLINE int
  65 __sigfillset (__sigset_t *__set)
  66 {
  67   /* SVR4 has a system call for `sigfillset' (!), and it only sets the bits
  68      for signals [1,31].  Setting bits for unimplemented signals seems
  69      harmless (and we will find out if it really is).  */
  70   __set->__sigbits[0] = __set->__sigbits[1] =
  71     __set->__sigbits[2] = __set->__sigbits[3] = ~0L;
  72   return 0;
  73 }
  74
  75 _EXTERN_INLINE int
  76 __sigaddset (__sigset_t *__set, int __sig)
  77 {
  78   __set->__sigbits[__SSELT (__sig)] |= __SSMASK (__sig);
  79   return 0;
  80 }
  81
  82 _EXTERN_INLINE int
  83 __sigdelset (__sigset_t *__set, int __sig)
  84 {
  85   __set->__sigbits[__SSELT (__sig)] &= ~__SSMASK (__sig);
  86   return 0;
  87 }
  88
  89 _EXTERN_INLINE int
  90 __sigismember (__const __sigset_t *__set, int __sig)
  91 {
  92   if (__set->__sigbits[__SSELT (__sig)] & __SSMASK (__sig))
  93     return 1;
  94   return 0;
  95 }
  96 #endif  /* use extern inlines.  */
  97
  98 #endif /* ! _SIGSET_H_fns */