1PTHREAD_ATTR_GETSTACK(3P)  POSIX Programmer's Manual PTHREAD_ATTR_GETSTACK(3P)
2
3
4

PROLOG

6       This  manual  page is part of the POSIX Programmer's Manual.  The Linux
7       implementation of this interface may differ (consult the  corresponding
8       Linux  manual page for details of Linux behavior), or the interface may
9       not be implemented on Linux.
10

NAME

12       pthread_attr_getstack,  pthread_attr_setstack  —  get  and  set   stack
13       attributes
14

SYNOPSIS

16       #include <pthread.h>
17
18       int pthread_attr_getstack(const pthread_attr_t *restrict attr,
19           void **restrict stackaddr, size_t *restrict stacksize);
20       int pthread_attr_setstack(pthread_attr_t *attr, void *stackaddr,
21           size_t stacksize);
22

DESCRIPTION

24       The   pthread_attr_getstack()  and  pthread_attr_setstack()  functions,
25       respectively, shall get and set the thread  creation  stack  attributes
26       stackaddr and stacksize in the attr object.
27
28       The  stack  attributes  specify  the area of storage to be used for the
29       created thread's stack. The base (lowest addressable byte) of the stor‐
30       age  shall be stackaddr, and the size of the storage shall be stacksize
31       bytes. The  stacksize  shall  be  at  least  {PTHREAD_STACK_MIN}.   The
32       pthread_attr_setstack()  function  may  fail with [EINVAL] if stackaddr
33       does not meet implementation-defined alignment requirements.  All pages
34       within  the  stack  described  by stackaddr and stacksize shall be both
35       readable and writable by the thread.
36
37       If the pthread_attr_getstack() function is called before the  stackaddr
38       attribute has been set, the behavior is unspecified.
39
40       The  behavior  is undefined if the value specified by the attr argument
41       to pthread_attr_getstack() or pthread_attr_setstack() does not refer to
42       an initialized thread attributes object.
43

RETURN VALUE

45       Upon  successful completion, these functions shall return a value of 0;
46       otherwise, an error number shall be returned to indicate the error.
47
48       The pthread_attr_getstack() function shall store  the  stack  attribute
49       values in stackaddr and stacksize if successful.
50

ERRORS

52       The pthread_attr_setstack() function shall fail if:
53
54       EINVAL The  value  of  stacksize  is  less  than {PTHREAD_STACK_MIN} or
55              exceeds an implementation-defined limit.
56
57       The pthread_attr_setstack() function may fail if:
58
59       EINVAL The value of stackaddr does not have proper alignment to be used
60              as  a  stack,  or  ((char  *)stackaddr + stacksize) lacks proper
61              alignment.
62
63       EACCES The stack page(s) described by stackaddr and stacksize  are  not
64              both readable and writable by the thread.
65
66       These functions shall not return an error code of [EINTR].
67
68       The following sections are informative.
69

EXAMPLES

71       None.
72

APPLICATION USAGE

74       These  functions are appropriate for use by applications in an environ‐
75       ment where the stack for a thread must be  placed  in  some  particular
76       region of memory.
77
78       While  it might seem that an application could detect stack overflow by
79       providing a protected page outside the  specified  stack  region,  this
80       cannot be done portably. Implementations are free to place the thread's
81       initial stack pointer anywhere within the specified region to  accommo‐
82       date  the machine's stack pointer behavior and allocation requirements.
83       Furthermore, on some architectures, such  as  the  IA‐64,  ``overflow''
84       might mean that two separate stack pointers allocated within the region
85       will overlap somewhere in the middle of the region.
86
87       After a successful call to pthread_attr_setstack(),  the  storage  area
88       specified by the stackaddr parameter is under the control of the imple‐
89       mentation, as described in Section 2.9.8,  Use  of  Application-Managed
90       Thread Stacks.
91
92       The  specification of the stackaddr attribute presents several ambigui‐
93       ties that make portable use of these functions impossible. For example,
94       the  standard  allows  implementations  to  impose  arbitrary alignment
95       requirements on stackaddr.  Applications cannot assume  that  a  buffer
96       obtained  from  malloc()  is  suitably  aligned. Note that although the
97       stacksize value passed to pthread_attr_setstack() must  satisfy  align‐
98       ment requirements, the same is not true for pthread_attr_setstacksize()
99       where the implementation must increase the specified size if  necessary
100       to achieve the proper alignment.
101

RATIONALE

103       If an implementation detects that the value specified by the attr argu‐
104       ment to pthread_attr_getstack()  or  pthread_attr_setstack()  does  not
105       refer  to  an  initialized  thread attributes object, it is recommended
106       that the function should fail and report an [EINVAL] error.
107

FUTURE DIRECTIONS

109       None.
110

SEE ALSO

112       pthread_attr_destroy(), pthread_attr_getdetachstate(),
113       pthread_attr_getstacksize(), pthread_create()
114
115       The Base Definitions volume of POSIX.1‐2017, <limits.h>, <pthread.h>
116
118       Portions  of  this text are reprinted and reproduced in electronic form
119       from IEEE Std 1003.1-2017, Standard for Information Technology --  Por‐
120       table  Operating System Interface (POSIX), The Open Group Base Specifi‐
121       cations Issue 7, 2018 Edition, Copyright (C) 2018 by the  Institute  of
122       Electrical  and  Electronics Engineers, Inc and The Open Group.  In the
123       event of any discrepancy between this version and the original IEEE and
124       The  Open Group Standard, the original IEEE and The Open Group Standard
125       is the referee document. The original Standard can be  obtained  online
126       at http://www.opengroup.org/unix/online.html .
127
128       Any  typographical  or  formatting  errors that appear in this page are
129       most likely to have been introduced during the conversion of the source
130       files  to  man page format. To report such errors, see https://www.ker
131       nel.org/doc/man-pages/reporting_bugs.html .
132
133
134
135IEEE/The Open Group                  2017            PTHREAD_ATTR_GETSTACK(3P)
Impressum