NAME
pthread_attr_get_np,
pthread_getattr_np —
get attributes of existing
thread
LIBRARY
library “libpthread”
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
Thepthread_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>.