PTHREAD_ATTR_SETSTACK(3)

NAME
pthread_attr_setstack, pthread_attr_getstack - set and get stack attributes

SYNOPSIS
#include <pthread.h>
int
pthread_attr_setstack(pthread_attr_t *attr, void *stackaddr, size_t stacksize);
int
pthread_attr_getstack(const pthread_attr_t *attr, void **stackaddr, size_t *stacksize);

DESCRIPTION
The functions pthread_attr_setstack() and pthread_attr_getstack(), respectively, set and get the thread creation stackaddr and stacksize attributes 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.

On OpenBSD the provided stack must be page-aligned. It will be replaced (meaning zeroed) with a new MAP_ANON | MAP_STACK mapping. It is recommended that the initial mapping be allocated using an allocator which has a matching deallocator that discards whole pages, to clear the MAP_STACK attribute afterwards.

RETURN VALUES
Upon successful completion, pthread_attr_setstack() and pthread_attr_getstack() return a value of 0. Otherwise, an error number is returned to indicate the error.

The pthread_attr_getstack() function stores the stackaddr attribute value in stackaddr and the stacksize attribute value in stacksize if successful.

ERRORS
The pthread_attr_setstack() function will fail if:

[EINVAL]
    The value of stacksize is less than PTHREAD_STACK_MIN or exceeds a system-imposed limit or the value of stackaddr is NULL.

These functions will not return an error code of [EINTR].

SEE ALSO
pthread_attr_init(3), pthread_attr_setdetachstate(3), pthread_attr_setguardsize(3), pthread_attr_setstackaddr(3), pthread_attr_setstacksize(3), pthread_create(3), pthreads(3)

STANDARDS
pthread_attr_setstack() and pthread_attr_getstack() conform to ISO/IEC 9945-1 ANSI/IEEE (“POSIX”) Std 1003.1, 2004 Edition.