[PATCH] Memory fencing problem in pthread cancellation

[Jeff Law]

On 01/14/2013 03:51 PM, Carlos O'Donell wrote:
> On 01/14/2013 03:50 PM, Roland McGrath wrote:
>> I'd like to see comments clarifying what the memory clobber is actually
>> accomplishing and why it's necessary.  The other introductions of barriers
>> that have no comments need comments.
>>
>
> Jeff,
>
> I'd suggest something like this:
>
>    atomic_write_barrier ();
> +  /* At the point at which any thread writes the handle
> +     to libgcc_s_handle, the initialization is complete.
> +     The writing of libgcc_s_handle is atomic. All other
> +     threads reading libgcc_s_handle do so atomically. Any
> +     thread that does not execute this function must issue
> +     a read barrier to ensure that all of the above has
> +     actually completed and that the values of the
> +     function pointers are correct.   */
>    libgcc_s_handle = handle;
Looks good to me.  Next iteration will include this change.

jeff