bluez/unit/test-ringbuf.c
Anderson Lizardo 39a53c09a0 shared: Fix undefined behavior when calculating next power of two
According to GCC documentation, __builtin_clz() is undefined if argument
is zero. The following problem was detected when compiling with -O0:

ERROR:unit/test-ringbuf.c:70:test_power2: assertion failed: (size1 ==
size2)

Also refactor align_power2() so the internal "find last set bit"
operation is in its own fls() function (similar to how kernel does).
fls() checks if argument is zero before calling __builtin_clz().
2014-01-27 09:55:27 -08:00

155 lines
3.2 KiB
C

/*
*
* BlueZ - Bluetooth protocol stack for Linux
*
* Copyright (C) 2012 Intel Corporation. All rights reserved.
*
*
* This program 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 of the License, or
* (at your option) any later version.
*
* This program 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., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*
*/
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#include <stdio.h>
#include <string.h>
#include <stdint.h>
#include <glib.h>
#include "src/shared/ringbuf.h"
static unsigned int nlpo2(unsigned int x)
{
x--;
x |= (x >> 1);
x |= (x >> 2);
x |= (x >> 4);
x |= (x >> 8);
x |= (x >> 16);
return x + 1;
}
static unsigned int fls(unsigned int x)
{
return x ? sizeof(x) * 8 - __builtin_clz(x) : 0;
}
static unsigned int align_power2(unsigned int u)
{
return 1 << fls(u - 1);
}
static void test_power2(void)
{
size_t i;
for (i = 1; i < 1000000; i++) {
size_t size1, size2, size3 = 1;
size1 = nlpo2(i);
size2 = align_power2(i);
/* Find the next power of two */
while (size3 < i && size3 < SIZE_MAX)
size3 <<= 1;
if (g_test_verbose())
g_print("%zu -> size1=%zu size2=%zu size3=%zu\n",
i, size1, size2, size3);
g_assert(size1 == size2);
g_assert(size2 == size3);
g_assert(size3 == size1);
}
}
static void test_alloc(void)
{
int i;
for (i = 2; i < 10000; i++) {
struct ringbuf *rb;
if (g_test_verbose())
g_print("Iteration %i\n", i);
rb = ringbuf_new(i);
g_assert(rb != NULL);
g_assert(ringbuf_capacity(rb) == ringbuf_avail(rb));
ringbuf_free(rb);
}
}
static void test_printf(void)
{
static size_t rb_size = 500;
static size_t rb_capa = 512;
struct ringbuf *rb;
int i;
rb = ringbuf_new(rb_size);
g_assert(rb != NULL);
g_assert(ringbuf_capacity(rb) == rb_capa);
for (i = 0; i < 10000; i++) {
size_t len, count = i % rb_capa;
char *str, *ptr;
if (!count)
continue;
if (g_test_verbose())
g_print("Iteration %i\n", i);
len = asprintf(&str, "%*c", (int) count, 'x');
g_assert(len == count);
len = ringbuf_printf(rb, "%s", str);
g_assert(len == count);
g_assert(ringbuf_len(rb) == count);
g_assert(ringbuf_avail(rb) == rb_capa - len);
ptr = ringbuf_peek(rb, 0, &len);
g_assert(ptr != NULL);
g_assert(len == count);
g_assert(strncmp(str, ptr, len) == 0);
len = ringbuf_drain(rb, count);
g_assert(len == count);
g_assert(ringbuf_len(rb) == 0);
g_assert(ringbuf_avail(rb) == rb_capa);
free(str);
}
ringbuf_free(rb);
}
int main(int argc, char *argv[])
{
g_test_init(&argc, &argv, NULL);
g_test_add_func("/ringbuf/power2", test_power2);
g_test_add_func("/ringbuf/alloc", test_alloc);
g_test_add_func("/ringbuf/printf", test_printf);
return g_test_run();
}