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. Neither the name of the author nor the names of any co-contributors
14 * may be used to endorse or promote products derived from this software
15 * without specific prior written permission.
17 * THIS SOFTWARE IS PROVIDED BY JOHN BIRRELL AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 #include <sys/types.h>
33 #include <sys/fcntl.h>
38 #include "pthread_private.h"
40 __weak_reference(__write, write);
43 _write(int fd, const void *buf, size_t nbytes)
45 struct pthread *curthread = _get_curthread();
52 /* POSIX says to do just this: */
56 /* Lock the file descriptor for write: */
57 if ((ret = _FD_LOCK(fd, FD_WRITE, NULL)) == 0) {
58 /* Get the read/write mode type: */
59 type = _thread_fd_getflags(fd) & O_ACCMODE;
61 /* Check if the file is not open for write: */
62 if (type != O_WRONLY && type != O_RDWR) {
63 /* File is not open for write: */
65 _FD_UNLOCK(fd, FD_WRITE);
69 /* Check if file operations are to block */
70 blocking = ((_thread_fd_getflags(fd) & O_NONBLOCK) == 0);
73 * Loop while no error occurs and until the expected number
74 * of bytes are written if performing a blocking write:
77 /* Perform a non-blocking write syscall: */
78 n = __sys_write(fd, (const char *)buf + 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 curthread->data.fd.fd = fd;
98 _thread_kern_set_timeout(NULL);
100 /* Reset the interrupted operation flag: */
101 curthread->interrupted = 0;
103 _thread_kern_sched_state(PS_FDW_WAIT,
107 * Check if the operation was
108 * interrupted by a signal
110 if (curthread->interrupted) {
112 /* Return partial success: */
115 /* Return an error: */
122 * If performing a non-blocking write,
123 * just return whatever the write syscall did:
125 } else if (!blocking) {
126 /* A non-blocking call might return zero: */
131 * If there was an error, return partial success
132 * (if any bytes were written) or else the error:
142 /* Check if the write has completed: */
143 } else if (num >= nbytes)
144 /* Return the number of bytes written: */
147 _FD_UNLOCK(fd, FD_WRITE);
153 __write(int fd, const void *buf, size_t nbytes)
157 _thread_enter_cancellation_point();
158 ret = _write(fd, buf, nbytes);
159 _thread_leave_cancellation_point();