NAME
pthread_attr_getstack, pthread_attr_setstack - get and set stack
attributes
SYNOPSIS
#include <pthread.h>
int pthread_attr_getstack(const pthread_attr_t *restrict attr,
void **restrict stackaddr, size_t *restrict stacksize);
int pthread_attr_setstack(pthread_attr_t *attr, void *stackaddr,
size_t stacksize);
DESCRIPTION
The pthread_attr_getstack() and pthread_attr_setstack() functions,
respectively, shall get and set the thread creation stack attributes
stackaddr and stacksize in the attr object.
The stack attributes specify the area of storage to be used for the
created thread’s stack. The base (lowest addressable byte) of the
storage shall be stackaddr, and the size of the storage shall be
stacksize bytes. The stacksize shall be at least {PTHREAD_STACK_MIN}.
The stackaddr shall be aligned appropriately to be used as a stack; for
example, pthread_attr_setstack() may fail with [EINVAL] if ( stackaddr
& 0x7) is not 0. All pages within the stack described by stackaddr and
stacksize shall be both readable and writable by the thread.
RETURN VALUE
Upon successful completion, these functions shall return a value of 0;
otherwise, an error number shall be returned to indicate the error.
The pthread_attr_getstack() function shall store the stack attribute
values in stackaddr and stacksize if successful.
ERRORS
The pthread_attr_setstack() function shall fail if:
EINVAL The value of stacksize is less than {PTHREAD_STACK_MIN} or
exceeds an implementation-defined limit.
The pthread_attr_setstack() function may fail if:
EINVAL The value of stackaddr does not have proper alignment to be used
as a stack, or if ( stackaddr + stacksize) lacks proper
alignment.
EACCES The stack page(s) described by stackaddr and stacksize are not
both readable and writable by the thread.
These functions shall not return an error code of [EINTR].
The following sections are informative.
EXAMPLES
None.
APPLICATION USAGE
These functions are appropriate for use by applications in an
environment where the stack for a thread must be placed in some
particular region of memory.
While it might seem that an application could detect stack overflow by
providing a protected page outside the specified stack region, this
cannot be done portably. Implementations are free to place the thread’s
initial stack pointer anywhere within the specified region to
accommodate the machine’s stack pointer behavior and allocation
requirements. Furthermore, on some architectures, such as the IA-64,
"overflow" might mean that two separate stack pointers allocated within
the region will overlap somewhere in the middle of the region.
RATIONALE
None.
FUTURE DIRECTIONS
None.
SEE ALSO
pthread_attr_init() , pthread_attr_setdetachstate() ,
pthread_attr_setstacksize() , pthread_create() , the Base Definitions
volume of IEEE Std 1003.1-2001, <limits.h>, <pthread.h>
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 .