DragonFly On-Line Manual Pages

PTHREAD_ATTR_GET_NP(3)                      DragonFly Library Functions Manual

NAME
     pthread_attr_get_np, pthread_getattr_np - get attributes of existing
     thread

LIBRARY
     POSIX Threads Library (libpthread, -lpthread)

SYNOPSIS
     #include <pthread.h>
     #include <pthread_np.h>

     int
     pthread_attr_get_np(pthread_t thread, pthread_attr_t *attr);

     int
     pthread_getattr_np(pthread_t thread, pthread_attr_t *attr);

DESCRIPTION
     The pthread_attr_get_np() and pthread_getattr_np() functions can be used
     to retrieve attributes of a running thread.  Most fields of
     pthread_attr_t structure are exact values of attributes provided at
     thread creation time (as parameter to pthread_create(3) function), except
     for the stack address.

     Value returned as attr is supposed to be used in conjunction with
     pthread_attr_get*() functions to retrieve individual values from
     pthread_attr_t structure.  Parameter attr should point to allocated
     memory area big enough to fit this structure.

     It is HIGHLY RECOMMENDED to use pthread_attr_init(3) function to allocate
     attribute storage.  pthread_getattr_np() does this automatically.

IMPLEMENTATION NOTES
     The pthread_attr_get_np() function will always return a pointer to the
     thread's real stack address, regardless of its value in the original
     attributes structure.

RETURN VALUES
     If successful, pthread_attr_get_np() and pthread_getattr_np() return 0.
     Otherwise, an error number is returned to indicate the error.

EXAMPLES
     size_t
     my_thread_stack_size(pthread_t pid)
     {
         pthread_attr_t attr;
         size_t size;

         pthread_attr_init(&attr);
         pthread_attr_get_np(pid, &attr);
         pthread_attr_getstacksize(&attr, &size);
         pthread_attr_destroy(&attr);
         return(size);
     }

ERRORS
     The pthread_attr_get_np() function will fail if:

     [EINVAL]           Invalid value for one of given parameters.

     [ESRC]             No thread could be found corresponding to that
                        specified by the given thread ID.

SEE ALSO
     pthread_attr_destroy(3), pthread_attr_getdetachstate(3),
     pthread_attr_getinheritsched(3), pthread_attr_getschedparam(3),
     pthread_attr_getschedpolicy(3), pthread_attr_getscope(3),
     pthread_attr_getstack(3), pthread_attr_getstackaddr(3),
     pthread_attr_getstacksize(3), pthread_attr_init(3)

AUTHORS
     The pthread_attr_get_np() function and this manual page were written by
     Alexey Zelkin <phantom@FreeBSD.org>.

DragonFly 5.9-DEVELOPMENT      December 12, 2020     DragonFly 5.9-DEVELOPMENT