PTHREAD_ATTR_SETGUARDSIZE(3)
OpenBSD Programmer's Manual
PTHREAD_ATTR_SETGUARDSIZE(3)NAME
pthread_attr_setguardsize, pthread_attr_getguardsize - set and get
guardsize attribute
SYNOPSIS
#include <pthread.h>
int
pthread_attr_setguardsize(pthread_attr_t *attr, size_t guardsize);
int
pthread_attr_getguardsize(const pthread_attr_t *attr, size_t *guardsize);
DESCRIPTION
The functions pthread_attr_setguardsize() and
pthread_attr_getguardsize(), respectively, set and get the thread
creation guardsize attribute in the attr object. If guardsize is zero, a
guard area shall not be provided for threads created with attr. If
guardsize is greater than zero, a guard area of at least size guardsize
bytes shall be provided for each thread created with attr.
The guardsize attribute controls the size of the guard area for the
created thread's stack. The guardsize attribute provides protection
against overflow of the stack pointer. If a thread's stack is created
with guard protection, the implementation allocates extra memory at the
overflow end of the stack as a buffer against stack overflow of the stack
pointer. If an application overflows into this buffer an error shall
result (possibly in a SIGSEGV signal being delivered to the thread).
RETURN VALUES
Upon successful completion, pthread_attr_setguardsize() and
pthread_attr_getguardsize() return a value of 0. Otherwise, an error
number is returned to indicate the error.
The pthread_attr_getguardsize() function stores the guardsize attribute
value in guardsize if successful.
ERRORS
No errors are defined.
These functions will not return an error code of [EINTR].
SEE ALSOpthread_attr_init(3), pthread_attr_setdetachstate(3),
pthread_attr_setstack(3), pthread_attr_setstackaddr(3),
pthread_attr_setstacksize(3), pthread_create(3), pthreads(3)STANDARDSpthread_attr_setguardsize() and pthread_attr_getguardsize() conform to
ISO/IEC 9945-1 ANSI/IEEE (``POSIX'') Std 1003.1, 2004 Edition.
OpenBSD 4.9 December 18, 2008 OpenBSD 4.9
