#At file:///export/home/x/mysql-5.5-bug43152/ based on revid:hezx@stripped
3258 Jon Olav Hauglid 2011-01-17
Bug #43152 Assertion `bitmap_is_set_all(&table->s->all_set)'
failed in handler::ha_reset
This assertion could be triggered if two connections simultaneously
executed two bitmap test functions on the same bitmap. Even if these
functions have read-only schematics and have const bitmaps as
parameters, several of them modified the internal state of the bitmap.
With interleaved execution of two such functions it was possible for
one function to modify the state of the same bitmap that the other
function had just modified. This lead to an inconsistent state and
could trigger the assert.
Internally the bitmap uses 32 bit words for storage. Since bitmaps
can contain any number of bits, the last word in the bitmap may
not be fully used. A 32 bit mask is maintained where a bit is set
if the corresponding bit in the last bitmap word is unused.
The problem was that several test functions applies this mask to
the last word. Some used bitwise AND and some used bitwise OR.
This meant that if a function first used bitwise AND and another
function then used bitwise OR before the first function tested
the result, the result would be invalid.
This patch fixes the problem by changing the implementation of
8 bitmap functions that modified the bitmap state even if the
bitmap was declared const. These functions now preserves the
internal state of the bitmap. This makes it possible for
two connections to concurrently execute two of these functions
on the same bitmap without issues.
The patch also removes dead testing code from my_bitmap.c.
These tests have already been moved to unittest/mysys/bitmap-t.c.
No test case added as this would require adding several sync
points to the bitmap functions. The patch has been tested with
a non-deterministic test case posted on the bug report.
modified:
include/my_bit.h
mysys/my_bitmap.c
=== modified file 'include/my_bit.h'
--- a/include/my_bit.h 2010-07-23 20:18:36 +0000
+++ b/include/my_bit.h 2011-01-17 11:36:50 +0000
@@ -49,6 +49,13 @@ static inline uint my_count_bits_ushort(
return _my_bits_nbits[v];
}
+static inline uint my_count_bits_uint32(uint32 v)
+{
+ return (uint) (uchar) (_my_bits_nbits[(uchar) v] +
+ _my_bits_nbits[(uchar) (v >> 8)] +
+ _my_bits_nbits[(uchar) (v >> 16)] +
+ _my_bits_nbits[(uchar) (v >> 24)]);
+}
/*
Next highest power of two
=== modified file 'mysys/my_bitmap.c'
--- a/mysys/my_bitmap.c 2011-01-11 09:07:37 +0000
+++ b/mysys/my_bitmap.c 2011-01-17 11:36:50 +0000
@@ -259,39 +259,42 @@ void bitmap_set_prefix(MY_BITMAP *map, u
my_bool bitmap_is_prefix(const MY_BITMAP *map, uint prefix_size)
{
- uint prefix_bits= prefix_size & 0x7, res;
- uchar *m= (uchar*)map->bitmap;
- uchar *end_prefix= m+prefix_size/8;
- uchar *end;
- DBUG_ASSERT(m && prefix_size <= map->n_bits);
- end= m+no_bytes_in_map(map);
-
- while (m < end_prefix)
- if (*m++ != 0xff)
- return 0;
-
- *map->last_word_ptr&= ~map->last_word_mask; /*Clear bits*/
- res= 0;
- if (prefix_bits && *m++ != (1 << prefix_bits)-1)
- goto ret;
-
- while (m < end)
- if (*m++ != 0)
- goto ret;
- res= 1;
-ret:
- return res;
+ my_bitmap_map prefix_bits= prefix_size & 0x7FFF;
+ my_bitmap_map *data_ptr= map->bitmap;
+ my_bitmap_map *end_prefix= data_ptr+prefix_size/32;
+ DBUG_ASSERT(data_ptr && prefix_size <= map->n_bits);
+
+ for (; data_ptr < end_prefix; data_ptr++)
+ if (*data_ptr != 0xFFFFFFFF)
+ return FALSE;
+
+ if (prefix_bits)
+ {
+ my_bitmap_map word= *data_ptr;
+ if (data_ptr++ == map->last_word_ptr)
+ word &= ~map->last_word_mask;
+ if (word != (my_bitmap_map)((1 << prefix_bits)-1))
+ return FALSE;
+ }
+
+ for (; data_ptr < map->last_word_ptr; data_ptr++)
+ if (*data_ptr != 0)
+ return FALSE;
+ if (data_ptr == map->last_word_ptr &&
+ (*map->last_word_ptr & ~map->last_word_mask) != 0)
+ return FALSE;
+ return TRUE;
}
my_bool bitmap_is_set_all(const MY_BITMAP *map)
{
my_bitmap_map *data_ptr= map->bitmap;
- my_bitmap_map *end= map->last_word_ptr;
- *map->last_word_ptr |= map->last_word_mask;
- for (; data_ptr <= end; data_ptr++)
+ for (; data_ptr < map->last_word_ptr; data_ptr++)
if (*data_ptr != 0xFFFFFFFF)
return FALSE;
+ if ((*map->last_word_ptr | map->last_word_mask) != 0xFFFFFFFF)
+ return FALSE;
return TRUE;
}
@@ -313,40 +316,44 @@ my_bool bitmap_is_clear_all(const MY_BIT
my_bool bitmap_is_subset(const MY_BITMAP *map1, const MY_BITMAP *map2)
{
- my_bitmap_map *m1= map1->bitmap, *m2= map2->bitmap, *end;
+ my_bitmap_map *m1= map1->bitmap, *m2= map2->bitmap;
DBUG_ASSERT(map1->bitmap && map2->bitmap &&
map1->n_bits==map2->n_bits);
- end= map1->last_word_ptr;
- *map1->last_word_ptr &= ~map1->last_word_mask;
- *map2->last_word_ptr &= ~map2->last_word_mask;
- while (m1 <= end)
+ while (m1 < map1->last_word_ptr)
{
if ((*m1++) & ~(*m2++))
- return 0;
+ return FALSE;
}
- return 1;
+
+ if ((*map1->last_word_ptr & ~map1->last_word_mask) &
+ ~(*map2->last_word_ptr & ~map2->last_word_mask))
+ return FALSE;
+
+ return TRUE;
}
/* True if bitmaps has any common bits */
my_bool bitmap_is_overlapping(const MY_BITMAP *map1, const MY_BITMAP *map2)
{
- my_bitmap_map *m1= map1->bitmap, *m2= map2->bitmap, *end;
+ my_bitmap_map *m1= map1->bitmap, *m2= map2->bitmap;
DBUG_ASSERT(map1->bitmap && map2->bitmap &&
map1->n_bits==map2->n_bits);
- end= map1->last_word_ptr;
- *map1->last_word_ptr &= ~map1->last_word_mask;
- *map2->last_word_ptr &= ~map2->last_word_mask;
- while (m1 <= end)
+ while (m1 < map1->last_word_ptr)
{
if ((*m1++) & (*m2++))
- return 1;
+ return TRUE;
}
- return 0;
+
+ if ((*map1->last_word_ptr & ~map1->last_word_mask) &
+ (*map2->last_word_ptr & ~map2->last_word_mask))
+ return TRUE;
+
+ return FALSE;
}
@@ -358,9 +365,13 @@ void bitmap_intersect(MY_BITMAP *map, co
DBUG_ASSERT(map->bitmap && map2->bitmap);
end= to+min(len,len2);
- *map2->last_word_ptr&= ~map2->last_word_mask; /*Clear last bits in map2*/
while (to < end)
- *to++ &= *from++;
+ {
+ if (from == map2->last_word_ptr)
+ *to++ &= (*from & ~map2->last_word_mask); /*Clear last bits in map2*/
+ else
+ *to++ &= *from++;
+ }
if (len2 < len)
{
@@ -451,15 +462,15 @@ void bitmap_invert(MY_BITMAP *map)
uint bitmap_bits_set(const MY_BITMAP *map)
-{
- uchar *m= (uchar*)map->bitmap;
- uchar *end= m + no_bytes_in_map(map);
+{
+ my_bitmap_map *data_ptr= map->bitmap;
uint res= 0;
DBUG_ASSERT(map->bitmap);
- *map->last_word_ptr&= ~map->last_word_mask; /*Reset last bits to zero*/
- while (m < end)
- res+= my_count_bits_ushort(*m++);
+ while (data_ptr < map->last_word_ptr)
+ res+= my_count_bits_uint32(*data_ptr++);
+ /*Reset last bits to zero*/
+ res+= my_count_bits_uint32(*map->last_word_ptr & ~map->last_word_mask);
return res;
}
@@ -479,26 +490,29 @@ void bitmap_copy(MY_BITMAP *map, const M
uint bitmap_get_first_set(const MY_BITMAP *map)
{
uchar *byte_ptr;
- uint i,j,k;
- my_bitmap_map *data_ptr, *end= map->last_word_ptr;
+ uint word_pos, byte_pos, bit_pos;
+ my_bitmap_map *data_ptr, last_word;
DBUG_ASSERT(map->bitmap);
data_ptr= map->bitmap;
- *map->last_word_ptr &= ~map->last_word_mask;
+ last_word= *map->last_word_ptr & ~map->last_word_mask;
- for (i=0; data_ptr <= end; data_ptr++, i++)
+ for (word_pos=0; data_ptr <= map->last_word_ptr; data_ptr++, word_pos++)
{
if (*data_ptr)
{
- byte_ptr= (uchar*)data_ptr;
- for (j=0; ; j++, byte_ptr++)
+ if (data_ptr == map->last_word_ptr)
+ byte_ptr= (uchar*)&last_word;
+ else
+ byte_ptr= (uchar*)data_ptr;
+ for (byte_pos=0; ; byte_pos++, byte_ptr++)
{
if (*byte_ptr)
{
- for (k=0; ; k++)
+ for (bit_pos=0; ; bit_pos++)
{
- if (*byte_ptr & (1 << k))
- return (i*32) + (j*8) + k;
+ if (*byte_ptr & (1 << bit_pos))
+ return (word_pos*32) + (byte_pos*8) + bit_pos;
}
}
}
@@ -511,26 +525,29 @@ uint bitmap_get_first_set(const MY_BITMA
uint bitmap_get_first(const MY_BITMAP *map)
{
uchar *byte_ptr;
- uint i,j,k;
- my_bitmap_map *data_ptr, *end= map->last_word_ptr;
+ uint word_pos, byte_pos, bit_pos;
+ my_bitmap_map *data_ptr, last_word;
DBUG_ASSERT(map->bitmap);
data_ptr= map->bitmap;
- *map->last_word_ptr|= map->last_word_mask;
+ last_word= *map->last_word_ptr | map->last_word_mask;
- for (i=0; data_ptr <= end; data_ptr++, i++)
+ for (word_pos=0; data_ptr <= map->last_word_ptr; data_ptr++, word_pos++)
{
if (*data_ptr != 0xFFFFFFFF)
{
- byte_ptr= (uchar*)data_ptr;
- for (j=0; ; j++, byte_ptr++)
+ if (data_ptr == map->last_word_ptr)
+ byte_ptr= (uchar*)&last_word;
+ else
+ byte_ptr= (uchar*)data_ptr;
+ for (byte_pos=0; ; byte_pos++, byte_ptr++)
{
if (*byte_ptr != 0xFF)
{
- for (k=0; ; k++)
+ for (bit_pos=0; ; bit_pos++)
{
- if (!(*byte_ptr & (1 << k)))
- return (i*32) + (j*8) + k;
+ if (!(*byte_ptr & (1 << bit_pos)))
+ return (word_pos*32) + (byte_pos*8) + bit_pos;
}
}
}
@@ -557,376 +574,3 @@ void bitmap_lock_clear_bit(MY_BITMAP *ma
bitmap_clear_bit(map, bitmap_bit);
bitmap_unlock(map);
}
-
-#ifdef MAIN
-
-uint get_rand_bit(uint bitsize)
-{
- return (rand() % bitsize);
-}
-
-bool test_set_get_clear_bit(MY_BITMAP *map, uint bitsize)
-{
- uint i, test_bit;
- uint no_loops= bitsize > 128 ? 128 : bitsize;
- for (i=0; i < no_loops; i++)
- {
- test_bit= get_rand_bit(bitsize);
- bitmap_set_bit(map, test_bit);
- if (!bitmap_is_set(map, test_bit))
- goto error1;
- bitmap_clear_bit(map, test_bit);
- if (bitmap_is_set(map, test_bit))
- goto error2;
- }
- return FALSE;
-error1:
- printf("Error in set bit, bit %u, bitsize = %u", test_bit, bitsize);
- return TRUE;
-error2:
- printf("Error in clear bit, bit %u, bitsize = %u", test_bit, bitsize);
- return TRUE;
-}
-
-bool test_flip_bit(MY_BITMAP *map, uint bitsize)
-{
- uint i, test_bit;
- uint no_loops= bitsize > 128 ? 128 : bitsize;
- for (i=0; i < no_loops; i++)
- {
- test_bit= get_rand_bit(bitsize);
- bitmap_flip_bit(map, test_bit);
- if (!bitmap_is_set(map, test_bit))
- goto error1;
- bitmap_flip_bit(map, test_bit);
- if (bitmap_is_set(map, test_bit))
- goto error2;
- }
- return FALSE;
-error1:
- printf("Error in flip bit 1, bit %u, bitsize = %u", test_bit, bitsize);
- return TRUE;
-error2:
- printf("Error in flip bit 2, bit %u, bitsize = %u", test_bit, bitsize);
- return TRUE;
-}
-
-bool test_operators(MY_BITMAP *map __attribute__((unused)),
- uint bitsize __attribute__((unused)))
-{
- return FALSE;
-}
-
-bool test_get_all_bits(MY_BITMAP *map, uint bitsize)
-{
- uint i;
- bitmap_set_all(map);
- if (!bitmap_is_set_all(map))
- goto error1;
- if (!bitmap_is_prefix(map, bitsize))
- goto error5;
- bitmap_clear_all(map);
- if (!bitmap_is_clear_all(map))
- goto error2;
- if (!bitmap_is_prefix(map, 0))
- goto error6;
- for (i=0; i<bitsize;i++)
- bitmap_set_bit(map, i);
- if (!bitmap_is_set_all(map))
- goto error3;
- for (i=0; i<bitsize;i++)
- bitmap_clear_bit(map, i);
- if (!bitmap_is_clear_all(map))
- goto error4;
- return FALSE;
-error1:
- printf("Error in set_all, bitsize = %u", bitsize);
- return TRUE;
-error2:
- printf("Error in clear_all, bitsize = %u", bitsize);
- return TRUE;
-error3:
- printf("Error in bitmap_is_set_all, bitsize = %u", bitsize);
- return TRUE;
-error4:
- printf("Error in bitmap_is_clear_all, bitsize = %u", bitsize);
- return TRUE;
-error5:
- printf("Error in set_all through set_prefix, bitsize = %u", bitsize);
- return TRUE;
-error6:
- printf("Error in clear_all through set_prefix, bitsize = %u", bitsize);
- return TRUE;
-}
-
-bool test_compare_operators(MY_BITMAP *map, uint bitsize)
-{
- uint i, j, test_bit1, test_bit2, test_bit3,test_bit4;
- uint no_loops= bitsize > 128 ? 128 : bitsize;
- MY_BITMAP map2_obj, map3_obj;
- MY_BITMAP *map2= &map2_obj, *map3= &map3_obj;
- my_bitmap_map map2buf[1024];
- my_bitmap_map map3buf[1024];
- bitmap_init(&map2_obj, map2buf, bitsize, FALSE);
- bitmap_init(&map3_obj, map3buf, bitsize, FALSE);
- bitmap_clear_all(map2);
- bitmap_clear_all(map3);
- for (i=0; i < no_loops; i++)
- {
- test_bit1=get_rand_bit(bitsize);
- bitmap_set_prefix(map, test_bit1);
- test_bit2=get_rand_bit(bitsize);
- bitmap_set_prefix(map2, test_bit2);
- bitmap_intersect(map, map2);
- test_bit3= test_bit2 < test_bit1 ? test_bit2 : test_bit1;
- bitmap_set_prefix(map3, test_bit3);
- if (!bitmap_cmp(map, map3))
- goto error1;
- bitmap_clear_all(map);
- bitmap_clear_all(map2);
- bitmap_clear_all(map3);
- test_bit1=get_rand_bit(bitsize);
- test_bit2=get_rand_bit(bitsize);
- test_bit3=get_rand_bit(bitsize);
- bitmap_set_prefix(map, test_bit1);
- bitmap_set_prefix(map2, test_bit2);
- test_bit3= test_bit2 > test_bit1 ? test_bit2 : test_bit1;
- bitmap_set_prefix(map3, test_bit3);
- bitmap_union(map, map2);
- if (!bitmap_cmp(map, map3))
- goto error2;
- bitmap_clear_all(map);
- bitmap_clear_all(map2);
- bitmap_clear_all(map3);
- test_bit1=get_rand_bit(bitsize);
- test_bit2=get_rand_bit(bitsize);
- test_bit3=get_rand_bit(bitsize);
- bitmap_set_prefix(map, test_bit1);
- bitmap_set_prefix(map2, test_bit2);
- bitmap_xor(map, map2);
- test_bit3= test_bit2 > test_bit1 ? test_bit2 : test_bit1;
- test_bit4= test_bit2 < test_bit1 ? test_bit2 : test_bit1;
- bitmap_set_prefix(map3, test_bit3);
- for (j=0; j < test_bit4; j++)
- bitmap_clear_bit(map3, j);
- if (!bitmap_cmp(map, map3))
- goto error3;
- bitmap_clear_all(map);
- bitmap_clear_all(map2);
- bitmap_clear_all(map3);
- test_bit1=get_rand_bit(bitsize);
- test_bit2=get_rand_bit(bitsize);
- test_bit3=get_rand_bit(bitsize);
- bitmap_set_prefix(map, test_bit1);
- bitmap_set_prefix(map2, test_bit2);
- bitmap_subtract(map, map2);
- if (test_bit2 < test_bit1)
- {
- bitmap_set_prefix(map3, test_bit1);
- for (j=0; j < test_bit2; j++)
- bitmap_clear_bit(map3, j);
- }
- if (!bitmap_cmp(map, map3))
- goto error4;
- bitmap_clear_all(map);
- bitmap_clear_all(map2);
- bitmap_clear_all(map3);
- test_bit1=get_rand_bit(bitsize);
- bitmap_set_prefix(map, test_bit1);
- bitmap_invert(map);
- bitmap_set_all(map3);
- for (j=0; j < test_bit1; j++)
- bitmap_clear_bit(map3, j);
- if (!bitmap_cmp(map, map3))
- goto error5;
- bitmap_clear_all(map);
- bitmap_clear_all(map3);
- }
- return FALSE;
-error1:
- printf("intersect error bitsize=%u,size1=%u,size2=%u", bitsize,
- test_bit1,test_bit2);
- return TRUE;
-error2:
- printf("union error bitsize=%u,size1=%u,size2=%u", bitsize,
- test_bit1,test_bit2);
- return TRUE;
-error3:
- printf("xor error bitsize=%u,size1=%u,size2=%u", bitsize,
- test_bit1,test_bit2);
- return TRUE;
-error4:
- printf("subtract error bitsize=%u,size1=%u,size2=%u", bitsize,
- test_bit1,test_bit2);
- return TRUE;
-error5:
- printf("invert error bitsize=%u,size=%u", bitsize,
- test_bit1);
- return TRUE;
-}
-
-bool test_count_bits_set(MY_BITMAP *map, uint bitsize)
-{
- uint i, bit_count=0, test_bit;
- uint no_loops= bitsize > 128 ? 128 : bitsize;
- for (i=0; i < no_loops; i++)
- {
- test_bit=get_rand_bit(bitsize);
- if (!bitmap_is_set(map, test_bit))
- {
- bitmap_set_bit(map, test_bit);
- bit_count++;
- }
- }
- if (bit_count==0 && bitsize > 0)
- goto error1;
- if (bitmap_bits_set(map) != bit_count)
- goto error2;
- return FALSE;
-error1:
- printf("No bits set bitsize = %u", bitsize);
- return TRUE;
-error2:
- printf("Wrong count of bits set, bitsize = %u", bitsize);
- return TRUE;
-}
-
-bool test_get_first_bit(MY_BITMAP *map, uint bitsize)
-{
- uint i, test_bit;
- uint no_loops= bitsize > 128 ? 128 : bitsize;
- for (i=0; i < no_loops; i++)
- {
- test_bit=get_rand_bit(bitsize);
- bitmap_set_bit(map, test_bit);
- if (bitmap_get_first_set(map) != test_bit)
- goto error1;
- bitmap_set_all(map);
- bitmap_clear_bit(map, test_bit);
- if (bitmap_get_first(map) != test_bit)
- goto error2;
- bitmap_clear_all(map);
- }
- return FALSE;
-error1:
- printf("get_first_set error bitsize=%u,prefix_size=%u",bitsize,test_bit);
- return TRUE;
-error2:
- printf("get_first error bitsize= %u, prefix_size= %u",bitsize,test_bit);
- return TRUE;
-}
-
-bool test_get_next_bit(MY_BITMAP *map, uint bitsize)
-{
- uint i, j, test_bit;
- uint no_loops= bitsize > 128 ? 128 : bitsize;
- for (i=0; i < no_loops; i++)
- {
- test_bit=get_rand_bit(bitsize);
- for (j=0; j < test_bit; j++)
- bitmap_set_next(map);
- if (!bitmap_is_prefix(map, test_bit))
- goto error1;
- bitmap_clear_all(map);
- }
- return FALSE;
-error1:
- printf("get_next error bitsize= %u, prefix_size= %u", bitsize,test_bit);
- return TRUE;
-}
-
-bool test_prefix(MY_BITMAP *map, uint bitsize)
-{
- uint i, j, test_bit;
- uint no_loops= bitsize > 128 ? 128 : bitsize;
- for (i=0; i < no_loops; i++)
- {
- test_bit=get_rand_bit(bitsize);
- bitmap_set_prefix(map, test_bit);
- if (!bitmap_is_prefix(map, test_bit))
- goto error1;
- bitmap_clear_all(map);
- for (j=0; j < test_bit; j++)
- bitmap_set_bit(map, j);
- if (!bitmap_is_prefix(map, test_bit))
- goto error2;
- bitmap_set_all(map);
- for (j=bitsize - 1; ~(j-test_bit); j--)
- bitmap_clear_bit(map, j);
- if (!bitmap_is_prefix(map, test_bit))
- goto error3;
- bitmap_clear_all(map);
- }
- return FALSE;
-error1:
- printf("prefix1 error bitsize = %u, prefix_size = %u", bitsize,test_bit);
- return TRUE;
-error2:
- printf("prefix2 error bitsize = %u, prefix_size = %u", bitsize,test_bit);
- return TRUE;
-error3:
- printf("prefix3 error bitsize = %u, prefix_size = %u", bitsize,test_bit);
- return TRUE;
-}
-
-
-bool do_test(uint bitsize)
-{
- MY_BITMAP map;
- my_bitmap_map buf[1024];
- if (bitmap_init(&map, buf, bitsize, FALSE))
- {
- printf("init error for bitsize %d", bitsize);
- goto error;
- }
- if (test_set_get_clear_bit(&map,bitsize))
- goto error;
- bitmap_clear_all(&map);
- if (test_flip_bit(&map,bitsize))
- goto error;
- bitmap_clear_all(&map);
- if (test_operators(&map,bitsize))
- goto error;
- bitmap_clear_all(&map);
- if (test_get_all_bits(&map, bitsize))
- goto error;
- bitmap_clear_all(&map);
- if (test_compare_operators(&map,bitsize))
- goto error;
- bitmap_clear_all(&map);
- if (test_count_bits_set(&map,bitsize))
- goto error;
- bitmap_clear_all(&map);
- if (test_get_first_bit(&map,bitsize))
- goto error;
- bitmap_clear_all(&map);
- if (test_get_next_bit(&map,bitsize))
- goto error;
- if (test_prefix(&map,bitsize))
- goto error;
- return FALSE;
-error:
- printf("\n");
- return TRUE;
-}
-
-int main()
-{
- int i;
- for (i= 1; i < 4096; i++)
- {
- printf("Start test for bitsize=%u\n",i);
- if (do_test(i))
- return -1;
- }
- printf("OK\n");
- return 0;
-}
-
-/*
- In directory mysys:
- make test_bitmap
- will build the bitmap tests and ./test_bitmap will execute it
-*/
-
-#endif
Attachment: [text/bzr-bundle] bzr/jon.hauglid@oracle.com-20110117113650-wqe0a6j5r66wko59.bundle
| Thread |
|---|
| • bzr commit into mysql-5.5 branch (jon.hauglid:3258) Bug#43152 | Jon Olav Hauglid | 17 Jan |
