reflect.c

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/****************************************************************************
 *
 *   Copyright (c) 2014 Andrew Tridgell. 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. Neither the name PX4 nor the names of its contributors may be
 *    used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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
 * COPYRIGHT OWNER 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.
 *
 ****************************************************************************/

/**
 * @file reflect.c
 *
 * simple data reflector for load testing terminals (especially USB)
 *
 * @author Andrew Tridgell
 */

#include <px4_platform_common/px4_config.h>
#include <unistd.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <stdbool.h>
#include <assert.h>
#include <systemlib/err.h>

__EXPORT int reflect_main(int argc, char *argv[]);

// memory corruption checking
#define MAX_BLOCKS 1000
static uint32_t nblocks;
struct block {
    uint32_t v[256];
};
static struct block *blocks[MAX_BLOCKS];

#define VALUE(i) ((i*7) ^ 0xDEADBEEF)

static void allocate_blocks(void)
{
    while (nblocks < MAX_BLOCKS) {
        blocks[nblocks] = calloc(1, sizeof(struct block));

        if (blocks[nblocks] == NULL) {
            break;
        }

        for (uint32_t i = 0; i < sizeof(blocks[nblocks]->v) / sizeof(uint32_t); i++) {
            blocks[nblocks]->v[i] = VALUE(i);
        }

        nblocks++;
    }

    printf("Allocated %u blocks\n", nblocks);
}

static void check_blocks(void)
{
    for (uint32_t n = 0; n < nblocks; n++) {
        for (uint32_t i = 0; i < sizeof(blocks[nblocks]->v) / sizeof(uint32_t); i++) {
            assert(blocks[n]->v[i] == VALUE(i));
        }
    }
}

int
reflect_main(int argc, char *argv[])
{
    uint32_t total = 0;
    printf("Starting reflector\n");

    allocate_blocks();

    while (true) {
        char buf[128];
        ssize_t n = read(0, buf, sizeof(buf));

        if (n < 0) {
            break;
        }

        if (n > 0) {
            write(1, buf, n);
        }

        total += n;

        if (total > 1024000) {
            check_blocks();
            total = 0;
        }
    }

    return OK;
}