Re: [tree-ssa mudflap] per-thread items

["Timothy J. Wood" <tjw at omnigroup dot com>]

On Saturday, May 17, 2003, at 10:19  AM, Eyal Lebedinsky wrote:
> Nevertheless, and as I should hit the bed now, is it possible
> that 'errno' is allocated for each thread and as such it cannot
> be registered once only at the start of the run? If so, does
> the current code handle this?


  Absolutely.  Mac OS X/Darwin has the following in <sys/errno.h>

extern int * __error __P((void));
#define errno (*__error())

  From the Darwin source:

#undef errno
extern int errno;
int *__error(void) {
    pthread_t self = pthread_self();
    /* If we're not a detached pthread, just return the global errno */
    if ((self == (pthread_t)0) || (self->sig != _PTHREAD_SIG) || 
(self->detached & _PTHREAD_CREATE_PARENT)) {
        return &errno;
    }
    return &self->err_no;
}


-tim