libc-top-half/musl/src/select/pselect.c

   1 #include <sys/select.h>
   2 #include <signal.h>
   3 #include <stdint.h>
   4 #include <errno.h>
   5 #include "syscall.h"
   6
   7 #define IS32BIT(x) !((x)+0x80000000ULL>>32)
   8 #define CLAMP(x) (int)(IS32BIT(x) ? (x) : 0x7fffffffU+((0ULL+(x))>>63))
   9
  10 int pselect(int n, fd_set *restrict rfds, fd_set *restrict wfds, fd_set *restrict efds, const struct timespec *restrict ts, const sigset_t *restrict mask)
  11 {
  12         syscall_arg_t data[2] = { (uintptr_t)mask, _NSIG/8 };
  13         time_t s = ts ? ts->tv_sec : 0;
  14         long ns = ts ? ts->tv_nsec : 0;
  15 #ifdef SYS_pselect6_time64
  16         int r = -ENOSYS;
  17         if (SYS_pselect6 == SYS_pselect6_time64 || !IS32BIT(s))
  18                 r = __syscall_cp(SYS_pselect6_time64, n, rfds, wfds, efds,
  19                         ts ? ((long long[]){s, ns}) : 0, data);
  20         if (SYS_pselect6 == SYS_pselect6_time64 || r!=-ENOSYS)
  21                 return __syscall_ret(r);
  22         s = CLAMP(s);
  23 #endif
  24         return syscall_cp(SYS_pselect6, n, rfds, wfds, efds,
  25                 ts ? ((long[]){s, ns}) : 0, data);
  26 }