mirror of
https://github.com/openvswitch/ovs
synced 2025-10-25 15:07:05 +00:00
a6913ea852
In function bitmap_allocate1(), the last "unsigned long" in bitmap was set to all 0-bits when (n_bits % BITMAP_ULONG_BITS == 0). This commit correctly sets it to all 1-bits. Signed-off-by: ZhengLingyun <konghuarukhr@163.com> Signed-off-by: Ben Pfaff <blp@nicira.com>
95 lines
2.7 KiB
C
95 lines
2.7 KiB
C
/*
|
|
* Copyright (c) 2008, 2009, 2011 Nicira, Inc.
|
|
*
|
|
* Licensed under the Apache License, Version 2.0 (the "License");
|
|
* you may not use this file except in compliance with the License.
|
|
* You may obtain a copy of the License at:
|
|
*
|
|
* http://www.apache.org/licenses/LICENSE-2.0
|
|
*
|
|
* Unless required by applicable law or agreed to in writing, software
|
|
* distributed under the License is distributed on an "AS IS" BASIS,
|
|
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|
* See the License for the specific language governing permissions and
|
|
* limitations under the License.
|
|
*/
|
|
|
|
#include <config.h>
|
|
#include "bitmap.h"
|
|
#include <string.h>
|
|
|
|
/* Allocates and returns a bitmap initialized to all-1-bits. */
|
|
unsigned long *
|
|
bitmap_allocate1(size_t n_bits)
|
|
{
|
|
size_t n_bytes = bitmap_n_bytes(n_bits);
|
|
size_t n_longs = bitmap_n_longs(n_bits);
|
|
size_t r_bits = n_bits % BITMAP_ULONG_BITS;
|
|
unsigned long *bitmap;
|
|
|
|
/* Allocate and initialize most of the bitmap. */
|
|
bitmap = xmalloc(n_bytes);
|
|
memset(bitmap, 0xff, n_bytes);
|
|
|
|
/* Ensure that the last "unsigned long" in the bitmap only has as many
|
|
* 1-bits as there actually should be. */
|
|
if (r_bits) {
|
|
bitmap[n_longs - 1] = (1UL << r_bits) - 1;
|
|
}
|
|
|
|
return bitmap;
|
|
}
|
|
|
|
/* Sets 'count' consecutive bits in 'bitmap', starting at bit offset 'start',
|
|
* to 'value'. */
|
|
void
|
|
bitmap_set_multiple(unsigned long *bitmap, size_t start, size_t count,
|
|
bool value)
|
|
{
|
|
for (; count && start % BITMAP_ULONG_BITS; count--) {
|
|
bitmap_set(bitmap, start++, value);
|
|
}
|
|
for (; count >= BITMAP_ULONG_BITS; count -= BITMAP_ULONG_BITS) {
|
|
*bitmap_unit__(bitmap, start) = -(unsigned long) value;
|
|
start += BITMAP_ULONG_BITS;
|
|
}
|
|
for (; count; count--) {
|
|
bitmap_set(bitmap, start++, value);
|
|
}
|
|
}
|
|
|
|
/* Compares the 'n' bits in bitmaps 'a' and 'b'. Returns true if all bits are
|
|
* equal, false otherwise. */
|
|
bool
|
|
bitmap_equal(const unsigned long *a, const unsigned long *b, size_t n)
|
|
{
|
|
size_t i;
|
|
|
|
if (memcmp(a, b, n / BITMAP_ULONG_BITS * sizeof(unsigned long))) {
|
|
return false;
|
|
}
|
|
for (i = ROUND_DOWN(n, BITMAP_ULONG_BITS); i < n; i++) {
|
|
if (bitmap_is_set(a, i) != bitmap_is_set(b, i)) {
|
|
return false;
|
|
}
|
|
}
|
|
return true;
|
|
}
|
|
|
|
/* Scans 'bitmap' from bit offset 'start' to 'end', excluding 'end' itself.
|
|
* Returns the bit offset of the lowest-numbered bit set to 1, or 'end' if
|
|
* all of the bits are set to 0. */
|
|
size_t
|
|
bitmap_scan(const unsigned long int *bitmap, size_t start, size_t end)
|
|
{
|
|
/* XXX slow */
|
|
size_t i;
|
|
|
|
for (i = start; i < end; i++) {
|
|
if (bitmap_is_set(bitmap, i)) {
|
|
break;
|
|
}
|
|
}
|
|
return i;
|
|
}
|