lib/libc/posix/_sigset.c

   1 #include <lib.h>
   2 /* System processes use simpler macros with no range error checking (defined in
   3  * signal.h). The ANSI signal() implementation now also uses the macro
   4  * versions, which makes hiding of the functions here a historical remains.
   5  *
   6  * _NSIG is supposed to be the highest signal number plus one.
   7  */
   8 #define sigaddset       _sigaddset
   9 #define sigdelset       _sigdelset
  10 #define sigemptyset     _sigemptyset
  11 #define sigfillset      _sigfillset
  12 #define sigismember     _sigismember
  13 #include <signal.h>
  14
  15 /* Low bit of signal masks. */
  16 #define SIGBIT_0        ((sigset_t) 1)
  17
  18 /* Mask of valid signals (0 - (_NSIG-1)). */
  19 #define SIGMASK         ((SIGBIT_0 << _NSIG) - 1)
  20
  21 #define sigisvalid(signo) ((unsigned) (signo) < _NSIG)
  22
  23 PUBLIC int sigaddset(set, signo)
  24 sigset_t *set;
  25 int signo;
  26 {
  27   if (!sigisvalid(signo)) {
  28         errno = EINVAL;
  29         return -1;
  30   }
  31   *set |= SIGBIT_0 << signo;
  32   return 0;
  33 }
  34
  35 PUBLIC int sigdelset(set, signo)
  36 sigset_t *set;
  37 int signo;
  38 {
  39   if (!sigisvalid(signo)) {
  40         errno = EINVAL;
  41         return -1;
  42   }
  43   *set &= ~(SIGBIT_0 << signo);
  44   return 0;
  45 }
  46
  47 PUBLIC int sigemptyset(set)
  48 sigset_t *set;
  49 {
  50   *set = 0;
  51   return 0;
  52 }
  53
  54 PUBLIC int sigfillset(set)
  55 sigset_t *set;
  56 {
  57   *set = SIGMASK;
  58   return 0;
  59 }
  60
  61 PUBLIC int sigismember(set, signo)
  62 _CONST sigset_t *set;
  63 int signo;
  64 {
  65   if (!sigisvalid(signo)) {
  66         errno = EINVAL;
  67         return -1;
  68   }
  69   if (*set & (SIGBIT_0 << signo))
  70         return 1;
  71   return 0;
  72 }