2 * Copyright (c) 1995-1998 John Birrell <jb@cimlogic.com.au>
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 3. All advertising materials mentioning features or use of this software
14 * must display the following acknowledgement:
15 * This product includes software developed by John Birrell.
16 * 4. Neither the name of the author nor the names of any co-contributors
17 * may be used to endorse or promote products derived from this software
18 * without specific prior written permission.
20 * THIS SOFTWARE IS PROVIDED BY JOHN BIRRELL AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * $Id: uthread_write.c,v 1.9 1998/06/14 09:36:11 jb Exp $
35 #include <sys/types.h>
36 #include <sys/fcntl.h>
42 #include "pthread_private.h"
45 write(int fd, const void *buf, size_t nbytes)
53 /* POSIX says to do just this: */
57 /* Lock the file descriptor for write: */
58 if ((ret = _FD_LOCK(fd, FD_WRITE, NULL)) == 0) {
59 /* Get the read/write mode type: */
60 type = _thread_fd_table[fd]->flags & O_ACCMODE;
62 /* Check if the file is not open for write: */
63 if (type != O_WRONLY && type != O_RDWR) {
64 /* File is not open for write: */
66 _FD_UNLOCK(fd, FD_WRITE);
70 /* Check if file operations are to block */
71 blocking = ((_thread_fd_table[fd]->flags & O_NONBLOCK) == 0);
74 * Loop while no error occurs and until the expected number
75 * of bytes are written if performing a blocking write:
78 /* Perform a non-blocking write syscall: */
79 n = _thread_sys_write(fd, buf + num, nbytes - num);
81 /* Check if one or more bytes were written: */
84 * Keep a count of the number of bytes
90 * If performing a blocking write, check if the
91 * write would have blocked or if some bytes
92 * were written but there are still more to
95 if (blocking && ((n < 0 && (errno == EWOULDBLOCK ||
96 errno == EAGAIN)) || (n >= 0 && num < nbytes))) {
97 _thread_run->data.fd.fd = fd;
98 _thread_kern_set_timeout(NULL);
100 /* Reset the interrupted operation flag: */
101 _thread_run->interrupted = 0;
103 _thread_kern_sched_state(PS_FDW_WAIT,
107 * Check if the operation was
108 * interrupted by a signal
110 if (_thread_run->interrupted) {
111 /* Return an error: */
116 * If performing a non-blocking write or if an
117 * error occurred, just return whatever the write
120 } else if (!blocking || n < 0) {
121 /* A non-blocking call might return zero: */
125 /* Check if the write has completed: */
126 } else if (num >= nbytes)
127 /* Return the number of bytes written: */
130 _FD_UNLOCK(fd, FD_RDWR);