The hashmap API always use an unsigned value for storing
and comparing hashes. Whereas this test code uses "int".
This works out in practice since one can typically
round-trip between "int" and "unsigned int". But since this
is essentially reference code for the hashmap API, we should
model using the correct types.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This function takes two ptr/len pairs, which implies that
they can be arbitrary buffers. But internally, it assumes
that each "ptr" is NUL-terminated at "len" (because we
memcpy an extra byte to pick up the NUL terminator).
In practice this works because each caller only ever passes
strlen(ptr) as the length. But let's drop the "len"
parameters to make our expectations clear.
Note that we can get rid of the "l1" and "l2" variables from
cmd_main() as a further cleanup, since they are now mostly
used to check whether the p1 and p2 arguments are present
(technically the length parameters conflated NULL with the
empty string, which we no longer do, but I think that is
actually an improvement).
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Using fgets() with a fixed-size buffer can lead to lines
being accidentally split across two calls if they are larger
than the buffer size.
As this is just a test helper, this is unlikely to be a
problem in practice. But since people may look at test
helpers as reference code, it's a good idea for them to
model the preferred behavior.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In general, using a bare snprintf can truncate the resulting
buffer, leading to confusing results. In this case we know
that our buffer is sized large enough to accommodate our
loop, so there's no bug. However, we should use xsnprintf()
to document (and check) that assumption, and to model good
practice to people reading the code.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When we allocate the test_entry flex-struct, we have to add
up all of the elements that go into the flex array. If these
were to overflow a size_t, this would allocate a too-small
buffer, which we would then overflow in our memcpy steps.
Since this is just a test-helper, it probably doesn't matter
in practice, but we should model the correct technique by
using the st_add() macros.
Unfortunately, we cannot use the FLEX_ALLOC() macros here,
because we are stuffing two different buffers into a single
flex array.
While we're here, let's also swap out "malloc" for our
error-checking "xmalloc", and use the preferred
"sizeof(*var)" instead of "sizeof(type)".
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
These two array allocations have several minor flaws:
- they use bare malloc, rather than our error-checking
xmalloc
- they do a bare multiplication to determine the total
size (which in theory can overflow, though in this case
the sizes are all constants)
- they use sizeof(type), but the type in the second one
doesn't match the actual array (though it's "int" versus
"unsigned int", which are guaranteed by C99 to have the
same size)
None of these are likely to be problems in practice, and
this is just a test helper. But since people often look at
test helpers as reference code, we should do our best to
model the recommended techniques.
Switching to ALLOC_ARRAY fixes all three.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This is to address concerns raised by ThreadSanitizer on the mailing list
about threaded unprotected R/W access to map.size with my previous "disallow
rehash" change (0607e10009).
See:
https://public-inbox.org/git/adb37b70139fd1e2bac18bfd22c8b96683ae18eb.1502780344.git.martin.agren@gmail.com/
Add API to hashmap to disable item counting and thus automatic rehashing.
Also include API to later re-enable them.
When item counting is disabled, the map.size field is invalid. So to
prevent accidents, the field has been renamed and an accessor function
hashmap_get_size() has been added. All direct references to this
field have been been updated. And the name of the field changed
to map.private_size to communicate this.
Here is the relevant output from ThreadSanitizer showing the problem:
WARNING: ThreadSanitizer: data race (pid=10554)
Read of size 4 at 0x00000082d488 by thread T2 (mutexes: write M16):
#0 hashmap_add hashmap.c:209
#1 hash_dir_entry_with_parent_and_prefix name-hash.c:302
#2 handle_range_dir name-hash.c:347
#3 handle_range_1 name-hash.c:415
#4 lazy_dir_thread_proc name-hash.c:471
#5 <null> <null>
Previous write of size 4 at 0x00000082d488 by thread T1 (mutexes: write M31):
#0 hashmap_add hashmap.c:209
#1 hash_dir_entry_with_parent_and_prefix name-hash.c:302
#2 handle_range_dir name-hash.c:347
#3 handle_range_1 name-hash.c:415
#4 handle_range_dir name-hash.c:380
#5 handle_range_1 name-hash.c:415
#6 lazy_dir_thread_proc name-hash.c:471
#7 <null> <null>
Martin gives instructions for running TSan on test t3008 in this post:
https://public-inbox.org/git/CAN0heSoJDL9pWELD6ciLTmWf-a=oyxe4EXXOmCKvsG5MSuzxsA@mail.gmail.com/
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
With the new field that is passed to the compare function, we can pass
through flags there instead of having multiple compare functions.
Also drop the cast to hashmap_cmp_fn.
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When using the hashmap a common need is to have access to caller provided
data in the compare function. A couple of times we abuse the keydata field
to pass in the data needed. This happens for example in patch-ids.c.
This patch changes the function signature of the compare function
to have one more void pointer available. The pointer given for each
invocation of the compare function must be defined in the init function
of the hashmap and is just passed through.
Documentation of this new feature is deferred to a later patch.
This is a rather mechanical conversion, just adding the new pass-through
parameter. However while at it improve the naming of the fields of all
compare functions used by hashmaps by ensuring unused parameters are
prefixed with 'unused_' and naming the parameters what they are (instead
of 'unused' make it 'unused_keydata').
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This keeps top dir a bit less crowded. And because these programs are
for testing purposes, it makes sense that they stay somewhere in t/
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
