pthread_t in 5.3

Daniel Eischen deischen at
Thu Jan 27 16:22:38 PST 2005

On Thu, 27 Jan 2005, Medi Montaseri wrote:

> I am confused about the pthread_t type in FreeBSD 5.3,  can you help..
> Based on /usr/include/pthread.h,
> typedef struct  pthread                 *pthread_t;
> and when I look for the declaration of "struct pthread" , all I find is
> a forward declaration with a comment that says,
> /*
>  * Forward structure definitions.
>  *
>  * These are mostly opaque to the user.
>  */
> struct pthread;
> That is 'struct pthread' is an opaque type....
> Then in my application, when I try to find my thread_id, I say
> cout << "my tid is " << pthread_self() << endl;
> and I get a hex value. Which is syntactically correct, but semantically
> in-correct.

Sorry, what pthread_t is, is not for you to know.  It is up to the
implementation to define it anyway that it wants.  And is also why
there is a pthread_equal() function.

> I'm not interested in the pointer, I'm interested in the numerical
> thread ID...

There is no such thing as defined by POSIX.

> Now at this point, you'll think all you have to do is to de-reference
> the pointer.
> But since 'struct pthrad' is opaque, gdb and myself are clueless to
> proceed from here.
> Can someone shed some light on this please...

I think you are trying to do something that is non-standard/portable.


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