PTHREAD_ATTR_GETSTACK
Section: POSIX Programmer's Manual (3P)
Updated: 2017
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PROLOG
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 implementatio-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 implementatio-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 Applicatio-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.1-2017,
<limits.h>,
<pthread.h>
COPYRIGHT
Portions of this text are reprinted and reproduced in electronic form
from IEEE Std 1003.-2017, Standard for Information Technology- Portable Operating System Interface (POSIX), The Open Group Base
Specifications Issue 7, 2018 Edition,
Copyright (C) 2018 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 .
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/ma-pages/reporting_bugs.html .
Index
- PROLOG
-
- NAME
-
- SYNOPSIS
-
- DESCRIPTION
-
- RETURN VALUE
-
- ERRORS
-
- EXAMPLES
-
- APPLICATION USAGE
-
- RATIONALE
-
- FUTURE DIRECTIONS
-
- SEE ALSO
-
- COPYRIGHT
-
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