SYNOPSIS

#include <pthread.h>

int pthread_attr_getstackaddr(const pthread_attr_t *restrict attr,
       void **restrict stackaddr);
int pthread_attr_setstackaddr(pthread_attr_t *attr, void *stackaddr);

DESCRIPTION

The pthread_attr_getstackaddr() and pthread_attr_setstackaddr() functions, respectively, shall get and set the thread creation stackaddr attribute in the attr object.

The stackaddr attribute specifies the location of storage to be used for the created thread's stack. The size of the storage shall be at least {PTHREAD_STACK_MIN}.

RETURN VALUE

Upon successful completion, pthread_attr_getstackaddr() and pthread_attr_setstackaddr() shall return a value of 0; otherwise, an error number shall be returned to indicate the error.

The pthread_attr_getstackaddr() function stores the stackaddr attribute value in stackaddr if successful.

EXAMPLES

None.

APPLICATION USAGE

The specification of the stackaddr attribute presents several ambiguities that make portable use of these interfaces impossible. The description of the single address parameter as a "stack" does not specify a particular relationship between the address and the "stack" implied by that address. For example, the address may be taken as the low memory address of a buffer intended for use as a stack, or it may be taken as the address to be used as the initial stack pointer register value for the new thread. These two are not the same except for a machine on which the stack grows "up" from low memory to high, and on which a "push" operation first stores the value in memory and then increments the stack pointer register. Further, on a machine where the stack grows "down" from high memory to low, interpretation of the address as the "low memory" address requires a determination of the intended size of the stack. IEEE Std 1003.1-2001 has introduced the new interfaces pthread_attr_setstack() and pthread_attr_getstack() to resolve these ambiguities.

RATIONALE

None.

FUTURE DIRECTIONS

None.

COPYRIGHT

Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology -- Portable Operating System Interface (POSIX), The Open Group Base Specifications Issue 6, Copyright (C) 2001-2003 by the Institute of Electrical and Electronics Engineers, Inc and The Open Group. In the event of any discrepancy between this version and the original IEEE and The Open Group Standard, the original IEEE and The Open Group Standard is the referee document. The original Standard can be obtained online at http://www.opengroup.org/unix/online.html .