Jan de Visser <jan@de-visser.net> writes:
> On March 2, 2015 09:50:49 AM Tom Lane wrote:
>> However, you could and should use pg_malloc0, which takes care of that
>> for you...
> I am (using pg_malloc, that is). So, just to be sure: pg_malloc memsets the
> block to 0, right?
No, it doesn't, but pg_malloc0 does. Consult the code if you're confused:
src/common/fe_memutils.c
> My question was more along the lines if memsetting to 0 to ensure that pointer
> fields are NULL and int/long fields are 0.
Yes, we do assume that widely, and so does a heck of a lot of other code.
In principle the C standard doesn't require that a NULL pointer be
all-zero-bits, only that casting "0" to a pointer yield a NULL pointer.
But certainly there are no modern implementations that don't represent
NULL as 0. Anybody who tried to do it differently would soon find that
hardly any real-world C code would run on their platform.
regards, tom lane