Add sk_calloc. Remove SkMemory_stdlib, which seems unused.

Add sk_calloc.  Remove SkMemory_stdlib, which seems unused.

I'm seeing basically no difference between malloc + bzero and calloc on my desktop, but on a Galaxy Nexus calloc is never slower, and significantly faster once the allocation size becomes large, both for allocation and for _reading_.

BUG=skia:1662
R=reed@google.com

Committed: https://code.google.com/p/skia/source/detail?r=11414

[reed1, 2013-09-19 20:48:09]

https://codereview.chromium.org/24251008/diff/3001/include/core/SkTypes.h
File include/core/SkTypes.h (right):

https://codereview.chromium.org/24251008/diff/3001/include/core/SkTypes.h#new...
include/core/SkTypes.h:69: SK_API extern void* sk_calloc(size_t num, size_t
size);
no way no how

[reed1, 2013-09-19 20:52:58]

my wish-list:

1. crash and return-null variants
2. one size parameter, not two

Don't really care if sk_calloc_throw is a macro for sk_malloc_flags(...,
CALLOC_FLAG) or a native function.

[mtklein, 2013-09-20 14:10:18]

On 2013/09/19 20:52:58, reed1 wrote:
> my wish-list:
> 
> 1. crash and return-null variants
> 2. one size parameter, not two
> 
> Don't really care if sk_calloc_throw is a macro for sk_malloc_flags(...,
> CALLOC_FLAG) or a native function.

How's this?

[reed1, 2013-09-20 14:13:23]

it is safe/legal to call realloc on a ptr returned from calloc?

lgtm w/ suggestion about what to call on failure

https://codereview.chromium.org/24251008/diff/11001/include/core/SkTypes.h
File include/core/SkTypes.h (right):

https://codereview.chromium.org/24251008/diff/11001/include/core/SkTypes.h#ne...
include/core/SkTypes.h:71: /** Same as sk_calloc, but calls sk_throw() instead
of returning NULL on failure.
sk_out_of_memory() ?

[mtklein, 2013-09-20 14:25:54]

On 2013/09/20 14:13:23, reed1 wrote:
> it is safe/legal to call realloc on a ptr returned from calloc?
> 
> lgtm w/ suggestion about what to call on failure
> 
> https://codereview.chromium.org/24251008/diff/11001/include/core/SkTypes.h
> File include/core/SkTypes.h (right):
> 
>
https://codereview.chromium.org/24251008/diff/11001/include/core/SkTypes.h#ne...
> include/core/SkTypes.h:71: /** Same as sk_calloc, but calls sk_throw() instead
> of returning NULL on failure.
> sk_out_of_memory() ?

Yes, you can realloc a pointer returned by calloc.  malloc, realloc, calloc, and
free all play together in the way you'd hope.

[mtklein, 2013-09-20 14:26:06]

https://codereview.chromium.org/24251008/diff/11001/include/core/SkTypes.h
File include/core/SkTypes.h (right):

https://codereview.chromium.org/24251008/diff/11001/include/core/SkTypes.h#ne...
include/core/SkTypes.h:71: /** Same as sk_calloc, but calls sk_throw() instead
of returning NULL on failure.
On 2013/09/20 14:13:24, reed1 wrote:
> sk_out_of_memory() ?

Done.

[mtklein, 2013-09-20 14:31:53]

Committed patchset #6 manually as r11414 (presubmit successful).