Re: Malloc -Z

On 27/07/2011, at 4:49 PM, grarpamp wrote:

> Was reading malloc(3) while chasing corruption suspects.
> Does the presence of -Z imply that without it, programs
> can be allocated dirty (non-zeroed) memory?
> If so, it seems running with -Z would be prudent if one cares.
> Therefore, what is the rough percent performance
> impact of -Z compared to default malloc?
>=20

malloc(3) has never provided zeroed memory. If you need zeroed memory in =
C, you either need to zero it yourself using memset(3), or use =
calloc(3).

It's been part of the language standard for over 20 years now, and is =
the same in that regard on every platform that provides malloc(3).

What would be prudent as a developer (and is the default in CURRENT I =
believe) is to use J - it enforces the "memory from malloc(3) is not =
guaranteed to be zeroed." by specifically setting it to non-zero.

> Bonus:
> What would be needed to make the useful streams:
> /dev/one
> /dev/10
> /dev/01
> In addition to /dev/zero.
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