pthread_attr_getstack

, pthread_attr_setstack

- get or set stack attributes

Synopsis

cc -mt  [ flag… ] file… [ library… ] 
#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, 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 is stackaddr, and the size of the storage is stacksize bytes. The stacksize argument must be at least {PTHREAD_STACK_MIN}. The stackaddr argument must be aligned appropriately to be used as a stack; for example, pthread_attr_setstack() might fail with EINVAL if (stackaddr & 0x7) is not 0. All pages within the stack described by stackaddr and stacksize are both readable and writable by the thread.

Return Values

Upon successful completion, these functions return a 0; otherwise, an error number is returned to indicate the error.

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

Errors

The pthread_attr_setstack() function will fail if:

EINVAL

The value of stacksize is less than {PTHREAD_STACK_MIN}.

The pthread_attr_setstack() function may fail if:

EACCES

The stack page(s) described by stackaddr and stacksize are not both readable and writable by the thread.

EINVAL

The value of stackaddr does not have proper alignment to be used as a stack, or (stackaddr + stacksize) lacks proper alignment.

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.

Attributes

See attributes(5) for descriptions of the following attributes:

See Also

pthread_attr_init(3C), pthread_attr_setdetachstate(3C), pthread_attr_setstacksize(3C), pthread_create(3C), attributes(5)