ocaml/otherlibs/win32unix/select.c

100 lines
3.1 KiB
C

/***********************************************************************/
/* */
/* Objective Caml */
/* */
/* Xavier Leroy, projet Cristal, INRIA Rocquencourt */
/* */
/* Copyright 1996 Institut National de Recherche en Informatique et */
/* en Automatique. All rights reserved. This file is distributed */
/* under the terms of the GNU Library General Public License, with */
/* the special exception on linking described in file ../../LICENSE. */
/* */
/***********************************************************************/
/* $Id$ */
#include <mlvalues.h>
#include <alloc.h>
#include <memory.h>
#include <signals.h>
#include "unixsupport.h"
static void fdlist_to_fdset(value fdlist, fd_set *fdset)
{
value l;
FD_ZERO(fdset);
for (l = fdlist; l != Val_int(0); l = Field(l, 1)) {
FD_SET(Socket_val(Field(l, 0)), fdset);
}
}
static value fdset_to_fdlist(value fdlist, fd_set *fdset)
{
value res = Val_int(0);
Begin_roots2(fdlist, res)
for (/*nothing*/; fdlist != Val_int(0); fdlist = Field(fdlist, 1)) {
value s = Field(fdlist, 0);
if (FD_ISSET(Socket_val(s), fdset)) {
value newres = alloc_small(2, 0);
Field(newres, 0) = s;
Field(newres, 1) = res;
res = newres;
}
}
End_roots();
return res;
}
CAMLprim value unix_select(value readfds, value writefds, value exceptfds, value timeout)
{
fd_set read, write, except;
double tm;
struct timeval tv;
struct timeval * tvp;
int retcode;
value res;
value read_list = Val_unit, write_list = Val_unit, except_list = Val_unit;
Begin_roots3 (readfds, writefds, exceptfds)
Begin_roots3 (read_list, write_list, except_list)
tm = Double_val(timeout);
if (readfds == Val_int(0)
&& writefds == Val_int(0)
&& exceptfds == Val_int(0)) {
if ( tm > 0.0 ) {
enter_blocking_section();
Sleep( (int)(tm * 1000));
leave_blocking_section();
}
read_list = write_list = except_list = Val_int(0);
} else {
fdlist_to_fdset(readfds, &read);
fdlist_to_fdset(writefds, &write);
fdlist_to_fdset(exceptfds, &except);
if (tm < 0.0)
tvp = (struct timeval *) NULL;
else {
tv.tv_sec = (int) tm;
tv.tv_usec = (int) (1e6 * (tm - (int) tm));
tvp = &tv;
}
enter_blocking_section();
retcode = select(FD_SETSIZE, &read, &write, &except, tvp);
leave_blocking_section();
if (retcode == -1) {
win32_maperr(WSAGetLastError());
uerror("select", Nothing);
}
read_list = fdset_to_fdlist(readfds, &read);
write_list = fdset_to_fdlist(writefds, &write);
except_list = fdset_to_fdlist(exceptfds, &except);
}
res = alloc_small(3, 0);
Field(res, 0) = read_list;
Field(res, 1) = write_list;
Field(res, 2) = except_list;
End_roots();
End_roots();
return res;
}