From: Hiromichi Watari
Date: April 26 2011 7:19pm
Subject: Re: Use of thread specific data with mysqld
List-Archive: http://lists.mysql.com/internals/38310
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Hi Sergei,
I tried but I just couldn't make my own thread specific data to coexist wit=
h structure st_my_thread_var so I ended up moving my data to the structure =
and used it instead.
I suppose there is really no reason to reinvent the wheel, is there ?
But anyway, thank you for your help and you are the best.
Hiromichi


--- On Sun, 4/24/11, Sergei Golubchik <serg@stripped> wrote:

> From: Sergei Golubchik <serg@stripped>
> Subject: Re: Use of thread specific data with mysqld
> To: "Hiromichi Watari" <hiromichiwatari@stripped>
> Cc: internals@stripped
> Date: Sunday, April 24, 2011, 5:04 PM
> Hi, Hiromichi!
>=20
> On Apr 24, Hiromichi Watari wrote:
> > Hi,
> > I'm trying to use thread specific data with mysqld but
> ran into a problem with my_errno generating Segmentation
> fault at the following line.
> > I know that my_errno is also thread specific data but
> not familiar with its implementation.
> > I'm using pthread_key_create(), pthread_setspecific()
> and pthread_getspecific() for my own thread specific data,
> is there something I should be aware of ?
> > Thanks,
> > Hiromichi
> >=20
> > p.s. I ran into this problem only if I try to use my
> own thread specific data, of course.
>=20
> probably you forgot to call my_thread_init() in the
> beginning of your
> thread function.
>=20
> Anyway, here's the code:
>=20
> #define my_errno my_thread_var->thr_errno
>=20
> #define my_thread_var (_my_thread_var())
>=20
> struct st_my_thread_var *_my_thread_var(void)
> {
> =A0 return=A0 my_pthread_getspecific(struct
> st_my_thread_var*,THR_KEY_mysys);
> }
>=20
> my_bool my_thread_init(void)
> {
> =A0 ...
> =A0 =A0 if (!(tmp=3D (struct st_my_thread_var *)
> calloc(1, sizeof(*tmp))))
> =A0 =A0 {
> =A0 =A0 =A0 error=3D 1;
> =A0 =A0 =A0 goto end;
> =A0 =A0 }
> =A0 =A0 pthread_setspecific(THR_KEY_mysys,tmp);
> =A0 ...
> }
>=20
> Regards,
> Sergei
>