Named fields in Structure Initialization

[Steven Grunza]

> -----Original Message-----
> From: rtems-devel-bounces at rtems.org [mailto:rtems-devel-
> bounces at rtems.org] On Behalf Of Joel Sherrill
> Sent: Friday, August 10, 2012 3:27 PM
> To: rtems-devel at rtems.org
> Subject: Named fields in Structure Initialization
> 
> Hi
> 
> I was looking at the definition of the default pthread_attr_t in
> cpukit/posix/src/pthread.c. What's the consensus on explicitly
> naming fields as opposed to using order to resolve things.
> 
> In the filesystem code, I think it is all named now. I was thinking
> of changing this over to something like this:
> 
> const pthread_attr_t _POSIX_Threads_Default_attributes = {
> 
>    .is_initialized = true,                       /* is_initialized
> */
>    .stackaddr = NULL,                            /* stackaddr */
>    .stacksize = 0,                               /* stacksize --
> will be
> adjusted to minimum */
>    .contentionscope = PTHREAD_SCOPE_PROCESS,     /* contentionscope
> */
>    .inheritsched = PTHREAD_INHERIT_SCHED,        /* inheritsched */
>    .schedpolicy = SCHED_FIFO,                    /* schedpolicy */
>    .schedparam = {                               /* schedparam */
>      .sched_priority = 2,                        /* sched_priority
> */
>      #if defined(_POSIX_SPORADIC_SERVER) || \
>          defined(_POSIX_THREAD_SPORADIC_SERVER)
>        .sched_ss_low_priority = 0,               /*
> sched_ss_low_priority */
>        .sched_ss_repl_period = { 0L, 0 },        /*
> sched_ss_repl_period */
>        .sched_ss_init_budget = { 0L, 0 }         /*
> sched_ss_init_budget */
>      #endif
>    },
> 
>    #if defined(_POSIX_THREAD_CPUTIME)
>      .cputime_clock_allowed = 1,                 /*
> cputime_clock_allowed */
>    #endif
> 
>    .detachstate = PTHREAD_CREATE_JOINABLE,       /* detachstate */
> 
> };
> 
> --
> Joel Sherrill, Ph.D.             Director of Research&

Wow, just goes to prove there's always something new to learn.  I was
unaware of this ability in C to explicitly name fields like this.  

It seems to me that using explicit naming would decrease problems caused
by adding a new field to the structure but neglecting to update the
initialization.  I don't see a downside to this change, other than the
effort required to make the change.