Re: [PATCH 1/19] MUTEX: Introduce simple mutex implementation

[Nikita Danilov <nikita@clusterfs.com>]

Linus Torvalds writes:
 > 
 > 
 > On Thu, 15 Dec 2005, David Howells wrote:
 > > 
 > > 	FROM				TO
 > > 	==============================	=========================
 > > 	DECLARE_MUTEX			DECLARE_SEM_MUTEX
 > > 	DECLARE_MUTEX_LOCKED		DECLARE_SEM_MUTEX_LOCKED
 > > 	Proper counting semaphore	DECLARE_SEM
 > 
 > That sounds fine. I wouldn't be adverse to doing that - but it would have 
 > to be independently of any other changes, and it would need to simmer for 
 > a while for out-of-tree drivers etc to notice (ie you should _not_ just 
 > introduce a new "DECLARE_MUTEX()" immediately to confuse things).

Going off at a tangent (or tangle, rather), why do we need DECLARE_FOO()
macros at all? They

 - do not look like C variable declarations, hide variable type, and
 hence are confusing,

 - contrary to their naming actually _define_ rather than _declare_ an
 object.

In most cases 

        type var = INIT_FOO;

is much better (more readable and easier to understand) than

        DECLARE_FOO(var); /* what is the type of var? */

In the cases where initializer needs an address of object being
initialized

        type var = INIT_FOO(var);

can be used.

Nikita.