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Diffstat (limited to 'mit-pthreads/pthreads/readv.c')
| -rw-r--r-- | mit-pthreads/pthreads/readv.c | 85 |
1 files changed, 85 insertions, 0 deletions
diff --git a/mit-pthreads/pthreads/readv.c b/mit-pthreads/pthreads/readv.c new file mode 100644 index 00000000000..fd63d31cf94 --- /dev/null +++ b/mit-pthreads/pthreads/readv.c @@ -0,0 +1,85 @@ +/* ==== readv.c ============================================================ + * Copyright (c) 1995 by Chris Provenzano, proven@mit.edu + * 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 Chris Provenzano. + * 4. The name of Chris Provenzano may not be used to endorse or promote + * products derived from this software without specific prior written + * permission. + * + * THIS SOFTWARE IS PROVIDED BY CHRIS PROVENZANO ``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 CHRIS PROVENZANO 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. + * + * Description : Implementation of readv(). + * + * 1.00 95/06/19 proven + * -Started coding this file. + */ + +#ifndef lint +static const char rcsid[] = "$Id$"; +#endif + +#include "config.h" + +#ifndef HAVE_SYSCALL_READV + +#include <errno.h> +#include <unistd.h> +#include <sys/uio.h> +#include <sys/types.h> + +/* ========================================================================== + * machdep_sys_readv() + */ +int machdep_sys_readv(int fd, struct iovec * vector, int count) +{ + size_t bytes, i; + char *buffer; + int ret = 0; + + /* Find the total number of bytes to be read. */ + for (bytes = 0, i = 0; i < count; ++i) + bytes += vector[i].iov_len; + + if (bytes) { + /* + * Allocate a temporary buffer to hold the data. + * Don't use alloca because threads tend to have smaller stacks. + */ + if ((buffer = (char *)malloc(bytes)) == NULL) { + return(-ENOMEM); + } + ret = (int)machdep_sys_read(fd, buffer, bytes); + + /* Copy the data from memory specified by VECTOR to BUFFER */ + for (i = 0, bytes = 0; ret > 0; ret -= vector[i].iov_len) { + memcpy(vector[i].iov_base, buffer + bytes, + ret > vector[i].iov_len ? vector[i].iov_len : ret); + bytes += vector[i].iov_len; + } + free(buffer); + } + return(ret); +} + +#endif |