/*
 * Copyright (c) 1995-1996, 1998, 2000 University of Utah and the Flux Group.
 * All rights reserved.
 * 
 * This file is part of the Flux OSKit.  The OSKit is free software, also known
 * as "open source;" you can redistribute it and/or modify it under the terms
 * of the GNU General Public License (GPL), version 2, as published by the Free
 * Software Foundation (FSF).  To explore alternate licensing terms, contact
 * the University of Utah at csl-dist@cs.utah.edu or +1-801-585-3271.
 * 
 * The OSKit 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 GPL for more details.  You should have
 * received a copy of the GPL along with the OSKit; see the file COPYING.  If
 * not, write to the FSF, 59 Temple Place #330, Boston, MA 02111-1307, USA.
 */

/* Default implementation of writev()
   implemented with multiple calls to oskit_stream_write().  */

#include <unistd.h>
#include <sys/uio.h>
#include "fd.h"

ssize_t	writev(int fd, const struct iovec *vec, int count)
{
	oskit_u32_t	retval;
	ssize_t		actual = 0;
	oskit_error_t	rc;

#ifdef	THREAD_SAFE
	pthread_testcancel();
#endif

	if (fd_check_stream(fd))
		return -1;
	fd_access_lock(fd, FD_WRITE);

	while (--count >= 0)
	{
		rc = oskit_stream_write(fd_array[fd].stream,
					vec->iov_base, vec->iov_len, &retval);
		if (rc) {
			fd_unlock(fd);
			errno = rc;
			return -1;
		}

		actual += retval;
		if (retval < vec->iov_len)
			break;

		vec++;
	}
	fd_access_unlock(fd, FD_WRITE);
	return actual;
}