pthread_t in 5.3
Daniel Eischen
deischen at freebsd.org
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.
--
DE
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