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#include <machine/rtems-bsd-kernel-space.h>
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <string.h>
#include <stdarg.h>
/* #include <stdlib.h> */
#include <stdio.h>
#include <rtems.h>
#include <rtems/libio.h>
#include <rtems/error.h>
#include <rtems/rtems_bsdnet.h>
#include <errno.h>
#include <sys/fcntl.h>
#include <sys/types.h>
#include <sys/param.h>
#include <sys/mbuf.h>
#include <sys/select.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/protosw.h>
#include <sys/proc.h>
#include <sys/filio.h>
#include <net/if.h>
#include <net/route.h>
/*
*********************************************************************
* RTEMS implementation of select() system call *
*********************************************************************
*/
/*
* This implementation is quite restricted:
* Works on sockets only -- no support for other devices!
* A given socket can be in a read-select or a read/recv* by only
* one task at a time.
* A given socket can be in a write-select or a write/send* by only
* one task at a time.
*
* NOTE - select() is a very expensive system call. It should be avoided
* if at all possible. In many cases, rewriting the application
* to use multiple tasks (one per socket) is a better solution.
*/
static __inline int imin(int a, int b) { return (a < b ? a : b); }
struct socket *rtems_bsdnet_fdToSocket(int fd);
static int
socket_select (struct socket *so, int which, rtems_id tid)
{
switch (which) {
case FREAD:
if (soreadable(so))
return (1);
so->so_rcv.sb_flags |= SB_WAIT;
so->so_rcv.sb_sel.si_pid = tid;
break;
case FWRITE:
if (sowriteable(so))
return (1);
so->so_snd.sb_flags |= SB_WAIT;
so->so_snd.sb_sel.si_pid = tid;
break;
case 0:
if (so->so_oobmark || (so->so_state & SS_RCVATMARK))
return (1);
so->so_rcv.sb_sel.si_pid = tid;
break;
}
return (0);
}
static int
selscan (rtems_id tid, fd_mask **ibits, fd_mask **obits, int nfd, int *retval)
{
struct socket *so;
int msk, i, fd;
fd_mask bits, bit;
int n = 0;
static int flag[3] = { FREAD, FWRITE, 0 };
for (msk = 0; msk < 3; msk++) {
if (ibits[msk] == NULL)
continue;
for (i = 0; i < nfd; i += NFDBITS) {
bits = ibits[msk][i/NFDBITS];
for (fd = i, bit = 1 ; bits && (fd < nfd) ; fd++, bit <<= 1) {
if ((bits & bit) == 0)
continue;
bits &= ~bit;
so = rtems_bsdnet_fdToSocket (fd);
if (so == NULL)
return (EBADF);
if (socket_select (so, flag[msk], tid)) {
obits[msk][fd/NFDBITS] |=
(1 << (fd % NFDBITS));
n++;
}
}
}
}
*retval = n;
return (0);
}
int
select (int nfds, fd_set *__restrict readfds, fd_set *__restrict writefds,
fd_set *__restrict exceptfds, struct timeval *__restrict tv)
{
fd_mask *ibits[3], *obits[3];
fd_set ob[3];
int error, timo;
int retval = 0;
rtems_id tid;
rtems_interval then = 0, now;
rtems_event_set in = SBWAIT_EVENT | RTEMS_EVENT_SYSTEM_NETWORK_CLOSE;
rtems_event_set out;
if (nfds < 0)
return (EINVAL);
if (tv) {
timo = tv->tv_sec * hz + tv->tv_usec / tick;
if (timo == 0)
timo = 1;
then = rtems_clock_get_ticks_since_boot();
}
else {
timo = 0;
}
#define getbits(name,i) if (name) { \
ibits[i] = &name->fds_bits[0]; \
obits[i] = &ob[i].fds_bits[0]; \
FD_ZERO(&ob[i]); \
} \
else ibits[i] = NULL
getbits (readfds, 0);
getbits (writefds, 1);
getbits (exceptfds, 2);
#undef getbits
rtems_task_ident (RTEMS_SELF, 0, &tid);
rtems_event_system_receive (in, RTEMS_EVENT_ANY | RTEMS_NO_WAIT, RTEMS_NO_TIMEOUT, &out);
for (;;) {
rtems_bsdnet_semaphore_obtain ();
error = selscan(tid, ibits, obits, nfds, &retval);
rtems_bsdnet_semaphore_release ();
if (error || retval)
break;
if (timo) {
now = rtems_clock_get_ticks_since_boot();
timo -= now - then;
if (timo <= 0)
break;
then = now;
}
rtems_event_system_receive (in, RTEMS_EVENT_ANY | RTEMS_WAIT, timo, &out);
}
#define putbits(name,i) if (name) *name = ob[i]
putbits (readfds, 0);
putbits (writefds, 1);
putbits (exceptfds, 2);
#undef putbits
if (error) {
errno = error;
retval = -1;
}
return (retval);
}
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