NAME

pthread_attr_get_np —

get attributes of existent thread

LIBRARY

POSIX Threads Library (libpthread, -lpthread)

SYNOPSIS

#include <pthread_np.h>

int
pthread_attr_get_np(pthread_t pid, pthread_attr_t *dst);

DESCRIPTION

The pthread_attr_get_np() function is used to get existent thread's attributes. 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 dst is supposed to be used in conjunction with pthread_attr_get*() functions to retrieve individual values from pthread_attr_t structure. Parameter dst 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.

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() function returns 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.
[ESRCH]: No thread could be found corresponding to that specified by the given thread ID.

AUTHORS

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