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
10int select(int n, fd_set *restrict rfds, fd_set *restrict wfds, fd_set *restrict efds, struct timeval *restrict tv)
11{
12 time_t s = tv ? tv->tv_sec : 0;
13 suseconds_t us = tv ? tv->tv_usec : 0;
14 long ns;
15 const time_t max_time = (1ULL<<8*sizeof(time_t)-1)-1;
16
17 if (s<0 || us<0) return __syscall_ret(-EINVAL);
18 if (us/1000000 > max_time - s) {
19 s = max_time;
20 us = 999999;
21 ns = 999999999;
22 } else {
23 s += us/1000000;
24 us %= 1000000;
25 ns = us*1000;
26 }
27
28#ifdef SYS_pselect6_time64
29 int r = -ENOSYS;
30 if (SYS_pselect6 == SYS_pselect6_time64 || !IS32BIT(s))
31 r = __syscall_cp(SYS_pselect6_time64, n, rfds, wfds, efds,
32 tv ? ((long long[]){s, ns}) : 0,
33 ((syscall_arg_t[]){ 0, _NSIG/8 }));
34 if (SYS_pselect6 == SYS_pselect6_time64 || r!=-ENOSYS)
35 return __syscall_ret(r);
36 s = CLAMP(s);
37#endif
38#ifdef SYS_select
39 return syscall_cp(SYS_select, n, rfds, wfds, efds,
40 tv ? ((long[]){s, us}) : 0);
41#else
42 return syscall_cp(SYS_pselect6, n, rfds, wfds, efds,
43 tv ? ((long[]){s, ns}) : 0, ((syscall_arg_t[]){ 0, _NSIG/8 }));
44#endif
45}