src/select/select.c

   1 #include <sys/select.h>
   2 #include <signal.h>
   3 #include <stdint.h>
   4 #include <errno.h>
   5 #include "syscall.h"
   6 #include "libc.h"
   7
   8 int select(int n, fd_set *restrict rfds, fd_set *restrict wfds, fd_set *restrict efds, struct timeval *restrict tv)
   9 {
  10 #ifdef SYS_select
  11         return syscall_cp(SYS_select, n, rfds, wfds, efds, tv);
  12 #else
  13         syscall_arg_t data[2] = { 0, _NSIG/8 };
  14         struct timespec ts;
  15         if (tv) {
  16                 if (tv->tv_sec < 0 || tv->tv_usec < 0)
  17                         return __syscall_ret(-EINVAL);
  18                 time_t extra_secs = tv->tv_usec / 1000000;
  19                 ts.tv_nsec = tv->tv_usec % 1000000 * 1000;
  20                 const time_t max_time = (1ULL<<8*sizeof(time_t)-1)-1;
  21                 ts.tv_sec = extra_secs > max_time - tv->tv_sec ?
  22                         max_time : tv->tv_sec + extra_secs;
  23         }
  24         return syscall_cp(SYS_pselect6, n, rfds, wfds, efds, tv ? &ts : 0, data);
  25 #endif
  26 }