NAME

       pthread_attr_setstack, pthread_attr_getstack - set/get stack attributes in thread attributes object

SYNOPSIS

       #include <pthread.h>

       int pthread_attr_setstack(pthread_attr_t *attr,
                                 void *stackaddr, size_t stacksize);
       int pthread_attr_getstack(pthread_attr_t *attr,
                                 void **stackaddr, size_t *stacksize);

       Compile and link with -pthread.

   Feature Test Macro Requirements for glibc (see feature_test_macros(7)):

       pthread_attr_getstack(), pthread_attr_setstack():
           _POSIX_C_SOURCE >= 200112L || _XOPEN_SOURCE >= 600

DESCRIPTION

       The  pthread_attr_setstack()  function  sets  the  stack  address and stack size attributes of the thread
       attributes object referred to by attr to the values specified in stackaddr and  stacksize,  respectively.
       These  attributes  specify  the  location  and  size of the stack that should be used by a thread that is
       created using the thread attributes object attr.

       stackaddr should point to the lowest addressable byte of a buffer of stacksize bytes that  was  allocated
       by the caller.  The pages of the allocated buffer should be both readable and writable.

       The  pthread_attr_getstack()  function  returns the stack address and stack size attributes of the thread
       attributes object referred to by attr in the buffers pointed to by stackaddr and stacksize, respectively.

RETURN VALUE

       On success, these functions return 0; on error, they return a nonzero error number.

ERRORS

       pthread_attr_setstack() can fail with the following error:

       EINVAL stacksize is less than PTHREAD_STACK_MIN (16384) bytes.  On some  systems,  this  error  may  also
              occur if stackaddr or stackaddr + stacksize is not suitably aligned.

       POSIX.1-2001 also documents an EACCES error if the stack area described by stackaddr and stacksize is not
       both readable and writable by the caller.

VERSIONS

       These functions are provided by glibc since version 2.2.

CONFORMING TO

       POSIX.1-2001.

NOTES

       These functions are provided for applications that must ensure that a  thread's  stack  is  placed  in  a
       particular location.  For most applications, this is not necessary, and the use of these functions should
       be avoided.  (Use pthread_attr_setstacksize(3) if an application simply requires a stack size other  than
       the default.)

       When  an  application employs pthread_attr_setstack(), it takes over the responsibility of allocating the
       stack.  Any guard size value that was set  using  pthread_attr_setguardsize(3)  is  ignored.   If  deemed
       necessary,  it  is the application's responsibility to allocate a guard area (one or more pages protected
       against reading and writing) to handle the possibility of stack overflow.

       The address specified in stackaddr should be suitably aligned: for full portability, align it on  a  page
       boundary  (sysconf(_SC_PAGESIZE)).   posix_memalign(3) may be useful for allocation.  Probably, stacksize
       should also be a multiple of the system page size.

       If attr is used to create multiple threads, then the caller  must  change  the  stack  address  attribute
       between  calls  to pthread_create(3); otherwise, the threads will attempt to use the same memory area for
       their stacks, and chaos will ensue.

EXAMPLE

       See pthread_attr_init(3).

SEE ALSO

       mmap(2), mprotect(2), posix_memalign(3), pthread_attr_init(3), pthread_attr_setguardsize(3),
       pthread_attr_setstackaddr(3), pthread_attr_setstacksize(3), pthread_create(3), pthreads(7)

COLOPHON

       This page is part of release 3.54 of the Linux man-pages project.  A description of the project, and
       information about reporting bugs, can be found at http://www.kernel.org/doc/man-pages/.