#28 Failed to find free UID

[Edwin Lim]

Hi,

I tried to let cpu find the first available UID but it
returned one that is alredy used. After poking into
the code, I think there might be a problem with the
functions bitvector_{set,unset,get}.

The structure member bitvector_s->bits is (uint32_t *),
but those functions assume it to be (uint8_t *). So
the references BV_BITS(b)[chunk] is going by every 4
bytes instead of every byte.

The function bitvector_firstunset_find() does not have
this problem as it does

uint8_t *bits = (uint8_t *)BV_BITS(b);

and uses bits instead of BV_BITS(b) directly.

Cheers,
e.

P.S. If the three functions were tested with a only
few UIDs (e.g., 1000, 1001 and 1002 in a 1000-2000
range), it will appear work in little endian machines,
but won't work on big endian machines. It can be
demonstrated in the silly program attached:

Irix MIPS:
BV_CHUNKSIZE_BYTES=4
BV_CHUNKSIZE=32
0
0
0
1

Linux i386:
BV_CHUNKSIZE_BYTES=4
BV_CHUNKSIZE=32
1
0
0
0

[Edwin Lim]

Endian test, just for fun.