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This manual page is part of the POSIX Programmer's Manual. The Linux implementation of
this interface may differ (consult the corresponding Linux manual page for details of
Linux behavior), or the interface may not be implemented on Linux.
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 pthread_attr_setstack() function may fail with [EINVAL] if
stackaddr does not meet implementation-defined alignment requirements. All pages within
the stack described by stackaddr and stacksize shall be both readable and writable by the
thread.
If the pthread_attr_getstack() function is called before the stackaddr attribute has been
set, the behavior is unspecified.
The behavior is undefined if the value specified by the attr argument to
pthread_attr_getstack() or pthread_attr_setstack() does not refer to an initialized thread
attributes object.
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
((char *)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.
After a successful call to pthread_attr_setstack(), the storage area specified by the
stackaddr parameter is under the control of the implementation, as described in Section
2.9.8, Use of Application-Managed Thread Stacks.
The specification of the stackaddr attribute presents several ambiguities that make
portable use of these functions impossible. For example, the standard allows
implementations to impose arbitrary alignment requirements on stackaddr. Applications
cannot assume that a buffer obtained from malloc() is suitably aligned. Note that although
the stacksize value passed to pthread_attr_setstack() must satisfy alignment requirements,
the same is not true for pthread_attr_setstacksize() where the implementation must
increase the specified size if necessary to achieve the proper alignment.
RATIONALE
If an implementation detects that the value specified by the attr argument to
pthread_attr_getstack() or pthread_attr_setstack() does not refer to an initialized thread
attributes object, it is recommended that the function should fail and report an [EINVAL]
error.
FUTURE DIRECTIONS
None.
SEE ALSO
pthread_attr_destroy(), pthread_attr_getdetachstate(), pthread_attr_getstacksize(),
pthread_create()
The Base Definitions volume of POSIX.1‐2008, <limits.h>, <pthread.h>
COPYRIGHT
Portions of this text are reprinted and reproduced in electronic form from IEEE Std
1003.1, 2013 Edition, Standard for Information Technology -- Portable Operating System
Interface (POSIX), The Open Group Base Specifications Issue 7, Copyright (C) 2013 by the
Institute of Electrical and Electronics Engineers, Inc and The Open Group. (This is
POSIX.1-2008 with the 2013 Technical Corrigendum 1 applied.) 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.unix.org/online.html .
Any typographical or formatting errors that appear in this page are most likely to have
been introduced during the conversion of the source files to man page format. To report
such errors, see https://www.kernel.org/doc/man-pages/reporting_bugs.html .