freebsd-dev/lib/libc_r/uthread/uthread_read.c
Julian Elischer 012dfd00b3 Reviewed by: julian
Submitted by:	 john birrel

One version of the pthreads library
another will follow with differnt actions under some cases..
not QUITE complete
1996-01-22 00:23:58 +00:00

75 lines
2.8 KiB
C

/*
* Copyright (c) 1995 John Birrell <jb@cimlogic.com.au>.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by John Birrell.
* 4. Neither the name of the author nor the names of any co-contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY JOHN BIRRELL AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
*/
#include <sys/types.h>
#include <sys/fcntl.h>
#include <sys/uio.h>
#include <errno.h>
#include <unistd.h>
#ifdef _THREAD_SAFE
#include <pthread.h>
#include "pthread_private.h"
ssize_t
read(int fd, void *buf, size_t nbytes)
{
int nonblock;
int ret;
int status;
if (fd < 0 || fd > _thread_dtablesize || _thread_fd_table[fd] == NULL) {
_thread_seterrno(_thread_run, EBADF);
ret = -1;
} else if ((nonblock = _thread_fd_table[fd]->flags & O_NONBLOCK) == 0 && (ret = _thread_fd_lock(fd, FD_READ, NULL, __FILE__, __LINE__)) != 0) {
/* Cannot lock file descriptor. */
} else {
while ((ret = _thread_sys_read(fd, buf, nbytes)) < 0) {
if (nonblock == 0 && (errno == EWOULDBLOCK || errno == EAGAIN)) {
_thread_kern_sig_block(&status);
_thread_run->data.fd.fd = fd;
_thread_kern_set_timeout(NULL);
_thread_kern_sched_state(PS_FDR_WAIT, __FILE__, __LINE__);
if (errno == EINTR) {
ret = -1;
break;
}
} else {
break;
}
}
if (nonblock == 0) {
_thread_fd_unlock(fd, FD_READ);
}
}
return (ret);
}
#endif