cloudstack/vnet/src/vnetd/select.c

110 lines
2.8 KiB
C

/*
* Copyright (C) 2003 - 2004 Mike Wray <mike.wray@hp.com>.
*
* 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
*/
#include <stdlib.h>
#include <errno.h>
#include <unistd.h>
#include "select.h"
#define MODULE_NAME "select"
#define DEBUG
#undef DEBUG
#include "debug.h"
/** Zero all the file descriptor sets.
*
* @param set select set
* @param fd file descriptor
* @return 0 on success, -1 otherwise
*/
void SelectSet_zero(SelectSet *set){
set->n = 0;
FD_ZERO(&set->rd);
FD_ZERO(&set->wr);
FD_ZERO(&set->er);
}
/** Add a file descriptor to the set.
*
* @param set select set
* @param fd file descriptor
* @param mode mask of sets to add to
* @return 0 on success, -1 otherwise
*/
void SelectSet_add(SelectSet *set, int fd, int mode){
if(fd < 0) return;
if(mode & SELECT_READ){
SelectSet_add_read(set, fd);
}
if(mode & SELECT_WRITE){
SelectSet_add_write(set, fd);
}
if(mode & SELECT_ERROR){
SelectSet_add_error(set, fd);
}
}
/** Add a file descriptor to the write set.
*
* @param set select set
* @param fd file descriptor
* @return 0 on success, -1 otherwise
*/
void SelectSet_add_read(SelectSet *set, int fd){
dprintf("> fd=%d\n", fd);
if(fd < 0) return;
FD_SET(fd, &set->rd);
if(fd > set->n) set->n = fd;
}
/** Add a file descriptor to the write set.
*
* @param set select set
* @param fd file descriptor
* @return 0 on success, -1 otherwise
*/
void SelectSet_add_write(SelectSet *set, int fd){
dprintf("> fd=%d\n", fd);
if(fd < 0) return;
FD_SET(fd, &set->wr);
if(fd > set->n) set->n = fd;
}
/** Add a file descriptor to the error set.
*
* @param set select set
* @param fd file descriptor
* @return 0 on success, -1 otherwise
*/
void SelectSet_add_error(SelectSet *set, int fd){
dprintf("> fd=%d\n", fd);
if(fd < 0) return;
FD_SET(fd, &set->er);
if(fd > set->n) set->n = fd;
}
/** Select on file descriptors.
*
* @param set select set
* @param timeout timeout (may be NULL for no timeout)
* @return 0 on success, -1 otherwise
*/
int SelectSet_select(SelectSet *set, struct timeval *timeout){
return select(set->n+1, &set->rd, &set->wr, &set->er, timeout);
}