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 AUTHOR 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
35 #include <sys/types.h>
36 #include <sys/fcntl.h>
41 #include "pthread_private.h"
43 __weak_reference(__write, write);
46 _write(int fd, const void *buf, size_t nbytes)
48 struct pthread *curthread = _get_curthread();
55 /* POSIX says to do just this: */
59 /* Lock the file descriptor for write: */
60 if ((ret = _FD_LOCK(fd, FD_WRITE, NULL)) == 0) {
61 /* Get the read/write mode type: */
62 type = _thread_fd_getflags(fd) & O_ACCMODE;
64 /* Check if the file is not open for write: */
65 if (type != O_WRONLY && type != O_RDWR) {
66 /* File is not open for write: */
68 _FD_UNLOCK(fd, FD_WRITE);
72 /* Check if file operations are to block */
73 blocking = ((_thread_fd_getflags(fd) & O_NONBLOCK) == 0);
76 * Loop while no error occurs and until the expected number
77 * of bytes are written if performing a blocking write:
80 /* Perform a non-blocking write syscall: */
81 n = __sys_write(fd, buf + num, nbytes - num);
83 /* Check if one or more bytes were written: */
86 * Keep a count of the number of bytes
92 * If performing a blocking write, check if the
93 * write would have blocked or if some bytes
94 * were written but there are still more to
97 if (blocking && ((n < 0 && (errno == EWOULDBLOCK ||
98 errno == EAGAIN)) || (n > 0 && num < nbytes))) {
99 curthread->data.fd.fd = fd;
100 _thread_kern_set_timeout(NULL);
102 /* Reset the interrupted operation flag: */
103 curthread->interrupted = 0;
105 _thread_kern_sched_state(PS_FDW_WAIT,
109 * Check if the operation was
110 * interrupted by a signal
112 if (curthread->interrupted) {
114 /* Return partial success: */
117 /* Return an error: */
124 * If performing a non-blocking write,
125 * just return whatever the write syscall did:
127 } else if (!blocking) {
128 /* A non-blocking call might return zero: */
133 * If there was an error, return partial success
134 * (if any bytes were written) or else the error:
144 /* Check if the write has completed: */
145 } else if (num >= nbytes)
146 /* Return the number of bytes written: */
149 _FD_UNLOCK(fd, FD_WRITE);
155 __write(int fd, const void *buf, size_t nbytes)
159 _thread_enter_cancellation_point();
160 ret = _write(fd, buf, nbytes);
161 _thread_leave_cancellation_point();