HBitmaps provides an array of bits. The bits are stored as usual in an array of unsigned longs, but HBitmap is also optimized to provide fast iteration over set bits; going from one bit to the next is O(logB n) worst case, with B = sizeof(long) * CHAR_BIT: the result is low enough that the number of levels is in fact fixed. In order to do this, it stacks multiple bitmaps with progressively coarser granularity; in all levels except the last, bit N is set iff the N-th unsigned long is nonzero in the immediately next level. When iteration completes on the last level it can examine the 2nd-last level to quickly skip entire words, and even do so recursively to skip blocks of 64 words or powers thereof (32 on 32-bit machines). Given an index in the bitmap, it can be split in group of bits like this (for the 64-bit case): bits 0-57 => word in the last bitmap | bits 58-63 => bit in the word bits 0-51 => word in the 2nd-last bitmap | bits 52-57 => bit in the word bits 0-45 => word in the 3rd-last bitmap | bits 46-51 => bit in the word So it is easy to move up simply by shifting the index right by log2(BITS_PER_LONG) bits. To move down, you shift the index left similarly, and add the word index within the group. Iteration uses ffs (find first set bit) to find the next word to examine; this operation can be done in constant time in most current architectures. Setting or clearing a range of m bits on all levels, the work to perform is O(m + m/W + m/W^2 + ...), which is O(m) like on a regular bitmap. When iterating on a bitmap, each bit (on any level) is only visited once. Hence, The total cost of visiting a bitmap with m bits in it is the number of bits that are set in all bitmaps. Unless the bitmap is extremely sparse, this is also O(m + m/W + m/W^2 + ...), so the amortized cost of advancing from one bit to the next is usually constant. Reviewed-by: Laszlo Ersek <lersek@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
409 lines
13 KiB
C
409 lines
13 KiB
C
/*
|
|
* Hierarchical bitmap unit-tests.
|
|
*
|
|
* Copyright (C) 2012 Red Hat Inc.
|
|
*
|
|
* Author: Paolo Bonzini <pbonzini@redhat.com>
|
|
*
|
|
* This work is licensed under the terms of the GNU GPL, version 2 or later.
|
|
* See the COPYING file in the top-level directory.
|
|
*/
|
|
|
|
#include <glib.h>
|
|
#include <stdarg.h>
|
|
#include "qemu/hbitmap.h"
|
|
|
|
#define LOG_BITS_PER_LONG (BITS_PER_LONG == 32 ? 5 : 6)
|
|
|
|
#define L1 BITS_PER_LONG
|
|
#define L2 (BITS_PER_LONG * L1)
|
|
#define L3 (BITS_PER_LONG * L2)
|
|
|
|
typedef struct TestHBitmapData {
|
|
HBitmap *hb;
|
|
unsigned long *bits;
|
|
size_t size;
|
|
int granularity;
|
|
} TestHBitmapData;
|
|
|
|
|
|
/* Check that the HBitmap and the shadow bitmap contain the same data,
|
|
* ignoring the same "first" bits.
|
|
*/
|
|
static void hbitmap_test_check(TestHBitmapData *data,
|
|
uint64_t first)
|
|
{
|
|
uint64_t count = 0;
|
|
size_t pos;
|
|
int bit;
|
|
HBitmapIter hbi;
|
|
int64_t i, next;
|
|
|
|
hbitmap_iter_init(&hbi, data->hb, first);
|
|
|
|
i = first;
|
|
for (;;) {
|
|
next = hbitmap_iter_next(&hbi);
|
|
if (next < 0) {
|
|
next = data->size;
|
|
}
|
|
|
|
while (i < next) {
|
|
pos = i >> LOG_BITS_PER_LONG;
|
|
bit = i & (BITS_PER_LONG - 1);
|
|
i++;
|
|
g_assert_cmpint(data->bits[pos] & (1UL << bit), ==, 0);
|
|
}
|
|
|
|
if (next == data->size) {
|
|
break;
|
|
}
|
|
|
|
pos = i >> LOG_BITS_PER_LONG;
|
|
bit = i & (BITS_PER_LONG - 1);
|
|
i++;
|
|
count++;
|
|
g_assert_cmpint(data->bits[pos] & (1UL << bit), !=, 0);
|
|
}
|
|
|
|
if (first == 0) {
|
|
g_assert_cmpint(count << data->granularity, ==, hbitmap_count(data->hb));
|
|
}
|
|
}
|
|
|
|
/* This is provided instead of a test setup function so that the sizes
|
|
are kept in the test functions (and not in main()) */
|
|
static void hbitmap_test_init(TestHBitmapData *data,
|
|
uint64_t size, int granularity)
|
|
{
|
|
size_t n;
|
|
data->hb = hbitmap_alloc(size, granularity);
|
|
|
|
n = (size + BITS_PER_LONG - 1) / BITS_PER_LONG;
|
|
if (n == 0) {
|
|
n = 1;
|
|
}
|
|
data->bits = g_new0(unsigned long, n);
|
|
data->size = size;
|
|
data->granularity = granularity;
|
|
hbitmap_test_check(data, 0);
|
|
}
|
|
|
|
static void hbitmap_test_teardown(TestHBitmapData *data,
|
|
const void *unused)
|
|
{
|
|
if (data->hb) {
|
|
hbitmap_free(data->hb);
|
|
data->hb = NULL;
|
|
}
|
|
if (data->bits) {
|
|
g_free(data->bits);
|
|
data->bits = NULL;
|
|
}
|
|
}
|
|
|
|
/* Set a range in the HBitmap and in the shadow "simple" bitmap.
|
|
* The two bitmaps are then tested against each other.
|
|
*/
|
|
static void hbitmap_test_set(TestHBitmapData *data,
|
|
uint64_t first, uint64_t count)
|
|
{
|
|
hbitmap_set(data->hb, first, count);
|
|
while (count-- != 0) {
|
|
size_t pos = first >> LOG_BITS_PER_LONG;
|
|
int bit = first & (BITS_PER_LONG - 1);
|
|
first++;
|
|
|
|
data->bits[pos] |= 1UL << bit;
|
|
}
|
|
|
|
if (data->granularity == 0) {
|
|
hbitmap_test_check(data, 0);
|
|
}
|
|
}
|
|
|
|
/* Reset a range in the HBitmap and in the shadow "simple" bitmap.
|
|
*/
|
|
static void hbitmap_test_reset(TestHBitmapData *data,
|
|
uint64_t first, uint64_t count)
|
|
{
|
|
hbitmap_reset(data->hb, first, count);
|
|
while (count-- != 0) {
|
|
size_t pos = first >> LOG_BITS_PER_LONG;
|
|
int bit = first & (BITS_PER_LONG - 1);
|
|
first++;
|
|
|
|
data->bits[pos] &= ~(1UL << bit);
|
|
}
|
|
|
|
if (data->granularity == 0) {
|
|
hbitmap_test_check(data, 0);
|
|
}
|
|
}
|
|
|
|
static void hbitmap_test_check_get(TestHBitmapData *data)
|
|
{
|
|
uint64_t count = 0;
|
|
uint64_t i;
|
|
|
|
for (i = 0; i < data->size; i++) {
|
|
size_t pos = i >> LOG_BITS_PER_LONG;
|
|
int bit = i & (BITS_PER_LONG - 1);
|
|
unsigned long val = data->bits[pos] & (1UL << bit);
|
|
count += hbitmap_get(data->hb, i);
|
|
g_assert_cmpint(hbitmap_get(data->hb, i), ==, val != 0);
|
|
}
|
|
g_assert_cmpint(count, ==, hbitmap_count(data->hb));
|
|
}
|
|
|
|
static void test_hbitmap_zero(TestHBitmapData *data,
|
|
const void *unused)
|
|
{
|
|
hbitmap_test_init(data, 0, 0);
|
|
}
|
|
|
|
static void test_hbitmap_unaligned(TestHBitmapData *data,
|
|
const void *unused)
|
|
{
|
|
hbitmap_test_init(data, L3 + 23, 0);
|
|
hbitmap_test_set(data, 0, 1);
|
|
hbitmap_test_set(data, L3 + 22, 1);
|
|
}
|
|
|
|
static void test_hbitmap_iter_empty(TestHBitmapData *data,
|
|
const void *unused)
|
|
{
|
|
hbitmap_test_init(data, L1, 0);
|
|
}
|
|
|
|
static void test_hbitmap_iter_partial(TestHBitmapData *data,
|
|
const void *unused)
|
|
{
|
|
hbitmap_test_init(data, L3, 0);
|
|
hbitmap_test_set(data, 0, L3);
|
|
hbitmap_test_check(data, 1);
|
|
hbitmap_test_check(data, L1 - 1);
|
|
hbitmap_test_check(data, L1);
|
|
hbitmap_test_check(data, L1 * 2 - 1);
|
|
hbitmap_test_check(data, L2 - 1);
|
|
hbitmap_test_check(data, L2);
|
|
hbitmap_test_check(data, L2 + 1);
|
|
hbitmap_test_check(data, L2 + L1);
|
|
hbitmap_test_check(data, L2 + L1 * 2 - 1);
|
|
hbitmap_test_check(data, L2 * 2 - 1);
|
|
hbitmap_test_check(data, L2 * 2);
|
|
hbitmap_test_check(data, L2 * 2 + 1);
|
|
hbitmap_test_check(data, L2 * 2 + L1);
|
|
hbitmap_test_check(data, L2 * 2 + L1 * 2 - 1);
|
|
hbitmap_test_check(data, L3 / 2);
|
|
}
|
|
|
|
static void test_hbitmap_iter_past(TestHBitmapData *data,
|
|
const void *unused)
|
|
{
|
|
hbitmap_test_init(data, L3, 0);
|
|
hbitmap_test_set(data, 0, L3);
|
|
hbitmap_test_check(data, L3);
|
|
}
|
|
|
|
static void test_hbitmap_set_all(TestHBitmapData *data,
|
|
const void *unused)
|
|
{
|
|
hbitmap_test_init(data, L3, 0);
|
|
hbitmap_test_set(data, 0, L3);
|
|
}
|
|
|
|
static void test_hbitmap_get_all(TestHBitmapData *data,
|
|
const void *unused)
|
|
{
|
|
hbitmap_test_init(data, L3, 0);
|
|
hbitmap_test_set(data, 0, L3);
|
|
hbitmap_test_check_get(data);
|
|
}
|
|
|
|
static void test_hbitmap_get_some(TestHBitmapData *data,
|
|
const void *unused)
|
|
{
|
|
hbitmap_test_init(data, 2 * L2, 0);
|
|
hbitmap_test_set(data, 10, 1);
|
|
hbitmap_test_check_get(data);
|
|
hbitmap_test_set(data, L1 - 1, 1);
|
|
hbitmap_test_check_get(data);
|
|
hbitmap_test_set(data, L1, 1);
|
|
hbitmap_test_check_get(data);
|
|
hbitmap_test_set(data, L2 - 1, 1);
|
|
hbitmap_test_check_get(data);
|
|
hbitmap_test_set(data, L2, 1);
|
|
hbitmap_test_check_get(data);
|
|
}
|
|
|
|
static void test_hbitmap_set_one(TestHBitmapData *data,
|
|
const void *unused)
|
|
{
|
|
hbitmap_test_init(data, 2 * L2, 0);
|
|
hbitmap_test_set(data, 10, 1);
|
|
hbitmap_test_set(data, L1 - 1, 1);
|
|
hbitmap_test_set(data, L1, 1);
|
|
hbitmap_test_set(data, L2 - 1, 1);
|
|
hbitmap_test_set(data, L2, 1);
|
|
}
|
|
|
|
static void test_hbitmap_set_two_elem(TestHBitmapData *data,
|
|
const void *unused)
|
|
{
|
|
hbitmap_test_init(data, 2 * L2, 0);
|
|
hbitmap_test_set(data, L1 - 1, 2);
|
|
hbitmap_test_set(data, L1 * 2 - 1, 4);
|
|
hbitmap_test_set(data, L1 * 4, L1 + 1);
|
|
hbitmap_test_set(data, L1 * 8 - 1, L1 + 1);
|
|
hbitmap_test_set(data, L2 - 1, 2);
|
|
hbitmap_test_set(data, L2 + L1 - 1, 8);
|
|
hbitmap_test_set(data, L2 + L1 * 4, L1 + 1);
|
|
hbitmap_test_set(data, L2 + L1 * 8 - 1, L1 + 1);
|
|
}
|
|
|
|
static void test_hbitmap_set(TestHBitmapData *data,
|
|
const void *unused)
|
|
{
|
|
hbitmap_test_init(data, L3 * 2, 0);
|
|
hbitmap_test_set(data, L1 - 1, L1 + 2);
|
|
hbitmap_test_set(data, L1 * 3 - 1, L1 + 2);
|
|
hbitmap_test_set(data, L1 * 5, L1 * 2 + 1);
|
|
hbitmap_test_set(data, L1 * 8 - 1, L1 * 2 + 1);
|
|
hbitmap_test_set(data, L2 - 1, L1 + 2);
|
|
hbitmap_test_set(data, L2 + L1 * 2 - 1, L1 + 2);
|
|
hbitmap_test_set(data, L2 + L1 * 4, L1 * 2 + 1);
|
|
hbitmap_test_set(data, L2 + L1 * 7 - 1, L1 * 2 + 1);
|
|
hbitmap_test_set(data, L2 * 2 - 1, L3 * 2 - L2 * 2);
|
|
}
|
|
|
|
static void test_hbitmap_set_twice(TestHBitmapData *data,
|
|
const void *unused)
|
|
{
|
|
hbitmap_test_init(data, L1 * 3, 0);
|
|
hbitmap_test_set(data, 0, L1 * 3);
|
|
hbitmap_test_set(data, L1, 1);
|
|
}
|
|
|
|
static void test_hbitmap_set_overlap(TestHBitmapData *data,
|
|
const void *unused)
|
|
{
|
|
hbitmap_test_init(data, L3 * 2, 0);
|
|
hbitmap_test_set(data, L1 - 1, L1 + 2);
|
|
hbitmap_test_set(data, L1 * 2 - 1, L1 * 2 + 2);
|
|
hbitmap_test_set(data, 0, L1 * 3);
|
|
hbitmap_test_set(data, L1 * 8 - 1, L2);
|
|
hbitmap_test_set(data, L2, L1);
|
|
hbitmap_test_set(data, L2 - L1 - 1, L1 * 8 + 2);
|
|
hbitmap_test_set(data, L2, L3 - L2 + 1);
|
|
hbitmap_test_set(data, L3 - L1, L1 * 3);
|
|
hbitmap_test_set(data, L3 - 1, 3);
|
|
hbitmap_test_set(data, L3 - 1, L2);
|
|
}
|
|
|
|
static void test_hbitmap_reset_empty(TestHBitmapData *data,
|
|
const void *unused)
|
|
{
|
|
hbitmap_test_init(data, L3, 0);
|
|
hbitmap_test_reset(data, 0, L3);
|
|
}
|
|
|
|
static void test_hbitmap_reset(TestHBitmapData *data,
|
|
const void *unused)
|
|
{
|
|
hbitmap_test_init(data, L3 * 2, 0);
|
|
hbitmap_test_set(data, L1 - 1, L1 + 2);
|
|
hbitmap_test_reset(data, L1 * 2 - 1, L1 * 2 + 2);
|
|
hbitmap_test_set(data, 0, L1 * 3);
|
|
hbitmap_test_reset(data, L1 * 8 - 1, L2);
|
|
hbitmap_test_set(data, L2, L1);
|
|
hbitmap_test_reset(data, L2 - L1 - 1, L1 * 8 + 2);
|
|
hbitmap_test_set(data, L2, L3 - L2 + 1);
|
|
hbitmap_test_reset(data, L3 - L1, L1 * 3);
|
|
hbitmap_test_set(data, L3 - 1, 3);
|
|
hbitmap_test_reset(data, L3 - 1, L2);
|
|
hbitmap_test_set(data, 0, L3 * 2);
|
|
hbitmap_test_reset(data, 0, L1);
|
|
hbitmap_test_reset(data, 0, L2);
|
|
hbitmap_test_reset(data, L3, L3);
|
|
hbitmap_test_set(data, L3 / 2, L3);
|
|
}
|
|
|
|
static void test_hbitmap_granularity(TestHBitmapData *data,
|
|
const void *unused)
|
|
{
|
|
/* Note that hbitmap_test_check has to be invoked manually in this test. */
|
|
hbitmap_test_init(data, L1, 1);
|
|
hbitmap_test_set(data, 0, 1);
|
|
g_assert_cmpint(hbitmap_count(data->hb), ==, 2);
|
|
hbitmap_test_check(data, 0);
|
|
hbitmap_test_set(data, 2, 1);
|
|
g_assert_cmpint(hbitmap_count(data->hb), ==, 4);
|
|
hbitmap_test_check(data, 0);
|
|
hbitmap_test_set(data, 0, 3);
|
|
g_assert_cmpint(hbitmap_count(data->hb), ==, 4);
|
|
hbitmap_test_reset(data, 0, 1);
|
|
g_assert_cmpint(hbitmap_count(data->hb), ==, 2);
|
|
}
|
|
|
|
static void test_hbitmap_iter_granularity(TestHBitmapData *data,
|
|
const void *unused)
|
|
{
|
|
HBitmapIter hbi;
|
|
|
|
/* Note that hbitmap_test_check has to be invoked manually in this test. */
|
|
hbitmap_test_init(data, 131072 << 7, 7);
|
|
hbitmap_iter_init(&hbi, data->hb, 0);
|
|
g_assert_cmpint(hbitmap_iter_next(&hbi), <, 0);
|
|
|
|
hbitmap_test_set(data, ((L2 + L1 + 1) << 7) + 8, 8);
|
|
hbitmap_iter_init(&hbi, data->hb, 0);
|
|
g_assert_cmpint(hbitmap_iter_next(&hbi), ==, (L2 + L1 + 1) << 7);
|
|
g_assert_cmpint(hbitmap_iter_next(&hbi), <, 0);
|
|
|
|
hbitmap_iter_init(&hbi, data->hb, (L2 + L1 + 2) << 7);
|
|
g_assert_cmpint(hbitmap_iter_next(&hbi), <, 0);
|
|
|
|
hbitmap_test_set(data, (131072 << 7) - 8, 8);
|
|
hbitmap_iter_init(&hbi, data->hb, 0);
|
|
g_assert_cmpint(hbitmap_iter_next(&hbi), ==, (L2 + L1 + 1) << 7);
|
|
g_assert_cmpint(hbitmap_iter_next(&hbi), ==, 131071 << 7);
|
|
g_assert_cmpint(hbitmap_iter_next(&hbi), <, 0);
|
|
|
|
hbitmap_iter_init(&hbi, data->hb, (L2 + L1 + 2) << 7);
|
|
g_assert_cmpint(hbitmap_iter_next(&hbi), ==, 131071 << 7);
|
|
g_assert_cmpint(hbitmap_iter_next(&hbi), <, 0);
|
|
}
|
|
|
|
static void hbitmap_test_add(const char *testpath,
|
|
void (*test_func)(TestHBitmapData *data, const void *user_data))
|
|
{
|
|
g_test_add(testpath, TestHBitmapData, NULL, NULL, test_func,
|
|
hbitmap_test_teardown);
|
|
}
|
|
|
|
int main(int argc, char **argv)
|
|
{
|
|
g_test_init(&argc, &argv, NULL);
|
|
hbitmap_test_add("/hbitmap/size/0", test_hbitmap_zero);
|
|
hbitmap_test_add("/hbitmap/size/unaligned", test_hbitmap_unaligned);
|
|
hbitmap_test_add("/hbitmap/iter/empty", test_hbitmap_iter_empty);
|
|
hbitmap_test_add("/hbitmap/iter/past", test_hbitmap_iter_past);
|
|
hbitmap_test_add("/hbitmap/iter/partial", test_hbitmap_iter_partial);
|
|
hbitmap_test_add("/hbitmap/iter/granularity", test_hbitmap_iter_granularity);
|
|
hbitmap_test_add("/hbitmap/get/all", test_hbitmap_get_all);
|
|
hbitmap_test_add("/hbitmap/get/some", test_hbitmap_get_some);
|
|
hbitmap_test_add("/hbitmap/set/all", test_hbitmap_set_all);
|
|
hbitmap_test_add("/hbitmap/set/one", test_hbitmap_set_one);
|
|
hbitmap_test_add("/hbitmap/set/two-elem", test_hbitmap_set_two_elem);
|
|
hbitmap_test_add("/hbitmap/set/general", test_hbitmap_set);
|
|
hbitmap_test_add("/hbitmap/set/twice", test_hbitmap_set_twice);
|
|
hbitmap_test_add("/hbitmap/set/overlap", test_hbitmap_set_overlap);
|
|
hbitmap_test_add("/hbitmap/reset/empty", test_hbitmap_reset_empty);
|
|
hbitmap_test_add("/hbitmap/reset/general", test_hbitmap_reset);
|
|
hbitmap_test_add("/hbitmap/granularity", test_hbitmap_granularity);
|
|
g_test_run();
|
|
|
|
return 0;
|
|
}
|