diff options
Diffstat (limited to 'lib/libc_r/uthread/uthread_writev.c')
| -rw-r--r-- | lib/libc_r/uthread/uthread_writev.c | 192 |
1 files changed, 192 insertions, 0 deletions
diff --git a/lib/libc_r/uthread/uthread_writev.c b/lib/libc_r/uthread/uthread_writev.c new file mode 100644 index 00000000000..92c10e94b8e --- /dev/null +++ b/lib/libc_r/uthread/uthread_writev.c @@ -0,0 +1,192 @@ +/* + * Copyright (c) 1995-1998 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. + * + * $Id: uthread_writev.c,v 1.1 1998/08/27 09:01:30 d Exp $ + * $OpenBSD: uthread_writev.c,v 1.1 1998/08/27 09:01:30 d Exp $ + * + */ +#include <sys/types.h> +#include <sys/fcntl.h> +#include <sys/uio.h> +#include <errno.h> +#include <stdlib.h> +#include <string.h> +#include <unistd.h> +#ifdef _THREAD_SAFE +#include <pthread.h> +#include "pthread_private.h" + +ssize_t +writev(int fd, const struct iovec * iov, int iovcnt) +{ + int blocking; + int idx = 0; + int type; + ssize_t cnt; + ssize_t n; + ssize_t num = 0; + ssize_t ret; + struct iovec liov[20]; + struct iovec *p_iov = liov; + + /* Check if the array size exceeds to compiled in size: */ + if (iovcnt > (sizeof(liov) / sizeof(struct iovec))) { + /* Allocate memory for the local array: */ + if ((p_iov = (struct iovec *) + malloc(iovcnt * sizeof(struct iovec))) == NULL) { + /* Insufficient memory: */ + errno = ENOMEM; + return (-1); + } + } + + /* Copy the caller's array so that it can be modified locally: */ + memcpy(p_iov,iov,iovcnt * sizeof(struct iovec)); + + /* Lock the file descriptor for write: */ + if ((ret = _FD_LOCK(fd, FD_WRITE, NULL)) == 0) { + /* Get the read/write mode type: */ + type = _thread_fd_table[fd]->flags & O_ACCMODE; + + /* Check if the file is not open for write: */ + if (type != O_WRONLY && type != O_RDWR) { + /* File is not open for write: */ + errno = EBADF; + _FD_UNLOCK(fd, FD_WRITE); + return (-1); + } + + /* Check if file operations are to block */ + blocking = ((_thread_fd_table[fd]->flags & O_NONBLOCK) == 0); + + /* + * Loop while no error occurs and until the expected number + * of bytes are written if performing a blocking write: + */ + while (ret == 0) { + /* Perform a non-blocking write syscall: */ + n = _thread_sys_writev(fd, &p_iov[idx], iovcnt - idx); + + /* Check if one or more bytes were written: */ + if (n > 0) { + /* + * Keep a count of the number of bytes + * written: + */ + num += n; + + /* + * Enter a loop to check if a short write + * occurred and move the index to the + * array entry where the short write + * ended: + */ + cnt = n; + while (cnt > 0 && idx < iovcnt) { + /* + * If the residual count exceeds + * the size of this vector, then + * it was completely written: + */ + if (cnt >= p_iov[idx].iov_len) + /* + * Decrement the residual + * count and increment the + * index to the next array + * entry: + */ + cnt -= p_iov[idx++].iov_len; + else { + /* + * This entry was only + * partially written, so + * adjust it's length + * and base pointer ready + * for the next write: + */ + p_iov[idx].iov_len -= cnt; + p_iov[idx].iov_base += cnt; + cnt = 0; + } + } + } + + /* + * If performing a blocking write, check if the + * write would have blocked or if some bytes + * were written but there are still more to + * write: + */ + if (blocking && ((n < 0 && (errno == EWOULDBLOCK || + errno == EAGAIN)) || (n >= 0 && idx < iovcnt))) { + _thread_run->data.fd.fd = fd; + _thread_kern_set_timeout(NULL); + + /* Reset the interrupted operation flag: */ + _thread_run->interrupted = 0; + + _thread_kern_sched_state(PS_FDW_WAIT, + __FILE__, __LINE__); + + /* + * Check if the operation was + * interrupted by a signal + */ + if (_thread_run->interrupted) { + /* Return an error: */ + ret = -1; + } + + /* + * If performing a non-blocking write or if an + * error occurred, just return whatever the write + * syscall did: + */ + } else if (!blocking || n < 0) { + /* A non-blocking call might return zero: */ + ret = n; + break; + + /* Check if the write has completed: */ + } else if (idx == iovcnt) + /* Return the number of bytes written: */ + ret = num; + } + _FD_UNLOCK(fd, FD_RDWR); + } + + /* If memory was allocated for the array, free it: */ + if (p_iov != liov) + free(p_iov); + + return (ret); +} +#endif |