Obtains the guardsize attribute of the specified thread
    attributes object.

1  –  C Binding

    #include <pthread.h>

    int
    pthread_attr_getguardsize (
                const pthread_attr_t   *attr,
                size_t   *guardsize);

2  –  Arguments

 attr

    Address of the thread attributes object whose guardsize attribute
    is obtained.

 guardsize

    Receives the value of the guardsize attribute of the thread
    attributes object specified by attr.

3  –  Description

    This routine obtains the value of the guardsize attribute of
    the thread attributes object specified in the attr argument and
    stores it in the location specified by the guardsize argument.
    The specified attributes object must already be initialized at
    the time this routine is called.

    When creating a thread, use a thread attributes object to specify
    nondefault values for thread attributes. The guardsize attribute
    of a thread attributes object specifies the minimum size (in
    bytes) of the guard area for the stack of a new thread.

    A guard area can help a multithreaded program detect the overflow
    of a thread's stack. A guard area is a region of no-access memory
    that the Threads Library allocates at the overflow end of the
    thread's stack. When any thread attempts to access a memory
    location within this region, a memory addressing violation
    occurs.

    Note that the value of the guardsize attribute of a particular
    thread attributes object does not necessarily correspond to the
    actual size of the guard area of any existing thread in your
    multithreaded program.

4  –  Return Values

    If an error condition occurs, this routine returns an integer
    value indicating the type of error. Possible return values are as
    follows:

    Return      Description

    0           Successful completion.
    [EINVAL]    The value specified by attr does not refer to an
                existing thread attributes object.

5  –  Associated Routines

       pthread_attr_init()
       pthread_attr_setguardsize()
       pthread_attr_setstacksize()
       pthread_create()