ossp-pkg/pth/pth_util.c
/*
** GNU Pth - The GNU Portable Threads
** Copyright (c) 1999-2007 Ralf S. Engelschall <rse@engelschall.com>
**
** This file is part of GNU Pth, a non-preemptive thread scheduling
** library which can be found at http://www.gnu.org/software/pth/.
**
** This library is free software; you can redistribute it and/or
** modify it under the terms of the GNU Lesser General Public
** License as published by the Free Software Foundation; either
** version 2.1 of the License, or (at your option) any later version.
**
** This library is distributed in the hope that it will be useful,
** but WITHOUT ANY WARRANTY; without even the implied warranty of
** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
** Lesser General Public License for more details.
**
** You should have received a copy of the GNU Lesser General Public
** License along with this library; if not, write to the Free Software
** Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
** USA, or contact Ralf S. Engelschall <rse@engelschall.com>.
**
** pth_util.c: Pth utility functions
*/
/* ``Premature optimization is
the root of all evil.''
-- D.E.Knuth */
#include "pth_p.h"
/* calculate numerical mimimum */
#if cpp
#define pth_util_min(a,b) \
((a) > (b) ? (b) : (a))
#endif
/* delete a pending signal */
static void pth_util_sigdelete_sighandler(int _sig)
{
/* nop */
return;
}
intern int pth_util_sigdelete(int sig)
{
sigset_t ss, oss;
struct sigaction sa, osa;
/* check status of signal */
sigpending(&ss);
if (!sigismember(&ss, sig))
return FALSE;
/* block signal and remember old mask */
sigemptyset(&ss);
sigaddset(&ss, sig);
pth_sc(sigprocmask)(SIG_BLOCK, &ss, &oss);
/* set signal action to our dummy handler */
sa.sa_handler = pth_util_sigdelete_sighandler;
sigfillset(&sa.sa_mask);
sa.sa_flags = 0;
if (sigaction(sig, &sa, &osa) != 0) {
pth_sc(sigprocmask)(SIG_SETMASK, &oss, NULL);
return FALSE;
}
/* now let signal be delivered */
sigfillset(&ss);
sigdelset(&ss, sig);
sigsuspend(&ss);
/* restore signal mask and handler */
sigaction(sig, &osa, NULL);
pth_sc(sigprocmask)(SIG_SETMASK, &oss, NULL);
return TRUE;
}
/* copy a string like strncpy() but always null-terminate */
intern char *pth_util_cpystrn(char *dst, const char *src, size_t dst_size)
{
register char *d, *end;
if (dst_size == 0)
return dst;
d = dst;
end = dst + dst_size - 1;
for (; d < end; ++d, ++src) {
if ((*d = *src) == '\0')
return d;
}
*d = '\0';
return d;
}
/* check whether a file-descriptor is valid */
intern int pth_util_fd_valid(int fd)
{
if (fd < 0 || fd >= FD_SETSIZE)
return FALSE;
if (fcntl(fd, F_GETFL) == -1 && errno == EBADF)
return FALSE;
return TRUE;
}
/* merge input fd set into output fds */
intern void pth_util_fds_merge(int nfd,
fd_set *ifds1, fd_set *ofds1,
fd_set *ifds2, fd_set *ofds2,
fd_set *ifds3, fd_set *ofds3)
{
register int s;
for (s = 0; s < nfd; s++) {
if (ifds1 != NULL)
if (FD_ISSET(s, ifds1))
FD_SET(s, ofds1);
if (ifds2 != NULL)
if (FD_ISSET(s, ifds2))
FD_SET(s, ofds2);
if (ifds3 != NULL)
if (FD_ISSET(s, ifds3))
FD_SET(s, ofds3);
}
return;
}
/* test whether fds in the input fd sets occurred in the output fds */
intern int pth_util_fds_test(int nfd,
fd_set *ifds1, fd_set *ofds1,
fd_set *ifds2, fd_set *ofds2,
fd_set *ifds3, fd_set *ofds3)
{
register int s;
for (s = 0; s < nfd; s++) {
if (ifds1 != NULL)
if (FD_ISSET(s, ifds1) && FD_ISSET(s, ofds1))
return TRUE;
if (ifds2 != NULL)
if (FD_ISSET(s, ifds2) && FD_ISSET(s, ofds2))
return TRUE;
if (ifds3 != NULL)
if (FD_ISSET(s, ifds3) && FD_ISSET(s, ofds3))
return TRUE;
}
return FALSE;
}
/*
* clear fds in input fd sets if not occurred in output fd sets and return
* number of remaining input fds. This number uses BSD select(2) semantics: a
* fd in two set counts twice!
*/
intern int pth_util_fds_select(int nfd,
fd_set *ifds1, fd_set *ofds1,
fd_set *ifds2, fd_set *ofds2,
fd_set *ifds3, fd_set *ofds3)
{
register int s;
register int n;
n = 0;
for (s = 0; s < nfd; s++) {
if (ifds1 != NULL && FD_ISSET(s, ifds1)) {
if (!FD_ISSET(s, ofds1))
FD_CLR(s, ifds1);
else
n++;
}
if (ifds2 != NULL && FD_ISSET(s, ifds2)) {
if (!FD_ISSET(s, ofds2))
FD_CLR(s, ifds2);
else
n++;
}
if (ifds3 != NULL && FD_ISSET(s, ifds3)) {
if (!FD_ISSET(s, ofds3))
FD_CLR(s, ifds3);
else
n++;
}
}
return n;
}
