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/* Basic read/write test.
Copyright (C) 2007 Free Software Foundation, Inc.
Written by Carl Fredrik Hammar <hammy.lite@gmail.com>
This file is part of the GNU Hurd.
The GNU Hurd is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License as
published by the Free Software Foundation; either version 2, or (at
your option) any later version.
The GNU Hurd is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111, USA. */
#include <error.h>
#include <stdlib.h>
#include <sys/mman.h>
#include <string.h>
#include "channel.h"
#define MIN(n, m) ((n) < (m) ? (n) : (m))
struct buf
{
size_t len;
char data[];
};
static error_t
buf_realloc (struct buf **buf, size_t len)
{
struct buf *new_buf = realloc (*buf, len + sizeof (struct buf));
if (!new_buf)
return ENOMEM;
new_buf->len = len;
*buf = new_buf;
return 0;
}
/* An implementation of a trivial fifo channel, where first written is
the first to be read, no matter who read it. Not really a channel
at all and only useful for testing. */
static error_t
triv_fifo_read (struct channel *channel,
size_t amount, void **buf, size_t *len)
{
struct buf *fifo_buf = channel->class_hook;
int n = MIN (amount, fifo_buf->len);
size_t new_len = fifo_buf->len - n;
int alloced = 0;
error_t err;
if (*len < n)
{
*buf = mmap (0, n, PROT_READ|PROT_WRITE, MAP_ANON, 0, 0);
if (*buf == MAP_FAILED)
return errno;
alloced = 1;
}
memcpy (*buf, fifo_buf->data, n);
*len = n;
memmove (fifo_buf->data, fifo_buf->data + n, new_len);
err = buf_realloc (&fifo_buf, new_len);
if (err)
{
if (alloced)
munmap (*buf, n);
return err;
}
return 0;
}
static error_t
triv_fifo_write (struct channel *channel, void *buf, size_t len,
size_t *amount)
{
struct buf *fifo_buf = channel->class_hook;
size_t old_len = fifo_buf->len;
size_t new_len = old_len + len;
error_t err;
err = buf_realloc (&fifo_buf, new_len);
if (err)
return err;
memcpy (fifo_buf->data + old_len, buf, len);
*amount = len;
return 0;
}
static error_t
triv_fifo_open (struct channel *channel, int flags)
{
struct buf *buf;
buf = malloc (sizeof (struct buf));
if (! buf)
return ENOMEM;
buf->len = 0;
channel->class_hook = buf;
return 0;
}
static void
triv_fifo_close (struct channel *fifo)
{
free (fifo->class_hook);
}
const struct channel_class triv_fifo_class =
{
.name = "triv_fifo",
.open = triv_fifo_open,
.close = triv_fifo_close,
.read = triv_fifo_read,
.write = triv_fifo_write
};
error_t
triv_fifo_create_hub (int flags, struct channel_hub **hub)
{
return channel_alloc_hub (&triv_fifo_class, 0, flags, hub);
}
static error_t
do_reads (struct channel *fifo, void *buf, size_t len, size_t step)
{
void *p, *end = buf + len;
size_t n;
error_t err;
for (p = buf, n = 1; p < end && n > 0; p += n)
{
void *q = p;
n = MIN (end - p, step);
err = channel_read (fifo, n, &q, &n);
if (err)
return err;
if (q != p)
memcpy (p, q, n);
}
return 0;
}
static error_t
do_writes (struct channel *fifo, void *buf, size_t len, size_t step)
{
void *p, *end = buf + len;
size_t n;
error_t err;
for (p = buf, n = 0; p < end; p += n)
{
n = MIN (end - p, step);
err = channel_write (fifo, p, n, &n);
if (err)
return err;
}
return 0;
}
int
main (int argc, char **argv)
{
struct channel_hub *fifo_hub;
struct channel *fifo;
void *data, *buf;
size_t len = 128 * 1024;
int i;
error_t err;
data = mmap (0, len, PROT_READ|PROT_WRITE, MAP_ANON, 0, 0);
if (data == MAP_FAILED)
error (1, errno, "main");
err = triv_fifo_create_hub (0, &fifo_hub);
if (err)
error (1, err, "triv_fifo_create_hub");
err = channel_open (fifo_hub, 0, &fifo);
if (err)
error (1, err, "triv_fifo_open");
/* Fill test data. */
for (i = 0; i < len; i++)
((char*) data)[i] = i;
/* Small writes. */
err = do_writes (fifo, data, 4 * 1024, 32);
if (err)
error (1, err, "triv_fifo_write (small)");
/* Large writes. */
err = do_writes (fifo, data + 4 * 1024, len - 4 * 1024, 4 * 1024);
if (err)
error (1, err, "triv_fifo_write (large)");
buf = mmap (0, len, PROT_READ|PROT_WRITE, MAP_ANON, 0, 0);
if (buf == MAP_FAILED)
error (1, errno, "main");
/* Small reads. */
err = do_reads (fifo, buf, 4 * 1024, 32);
if (err)
error (1, err, "triv_fifo_read (small)");
/* Large reads. */
err = do_reads (fifo, buf + 4 * 1024, len - 4 * 1024, 4 * 1024);
if (err)
error (1, err, "triv_fifo_read (large)");
if (memcmp (data, buf, len) != 0)
error (1, 0, "written data inconsistent with read data");
channel_close (fifo);
channel_free_hub (fifo_hub);
return 0;
}
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