pthread_default_stacksize_np(3T)										  pthread_default_stacksize_np(3T)

NAME

       pthread_default_stacksize_np() - change the default stacksize

SYNOPSIS

PARAMETERS

	      new_size	The new default stack size.

	      old_size	Pointer to where the old default stack size is returned.

DESCRIPTION

       The  function  allows  an  application  to  change  the default value for the stacksize attribute.  This function must be called before any
       threads have been created.  The new default stack size is passed in the new_size parameter. If not NULL, the previous default stack size is
       returned in old_size.  If new_size is zero, this function can be used (at any time) to query the current default stack size.

       On HP-UX, threads with default stack sizes are cached after they terminate.  The next time a thread is created with a default stack size, a
       cached thread (and its stack) are reused. This can result in significant performance improvements for

       However, if the default stack size is not appropriate for an application, it cannot take advantage  of  this  performance  enhancement.	By
       using  the  function,  the  threads  library will change the default stack size so that it matches the applications needs.  This allows the
       application to utilize the performance benefit of cached threads.

RETURN VALUE

       Upon successful completion, returns zero. Otherwise, an error number is returned to indicate the error (the variable is not set).

ERRORS

       If any of the following occur, the function returns the corresponding error number:

	      [EINVAL]	     The value specified by new_size is less than

	      [EPERM]	     The calling process has already created threads (this must be called before any threads are created).

WARNINGS

       If the environment variable is set with a valid value for default stack size, then it takes precedence over the	invocation  of	interface.
       However, it returns the current default stack size in old_size.

       The  maximum default stack size value that may be set through the environment variable is restricted to 10 MB; any value greater than 10 MB
       will be rounded down to 10 MB.

       Care should be taken while setting the default stack size limit since this could impact the maximum number of threads that can  be  created
       in a process.

AUTHOR

       was developed by HP.

SEE ALSO

       pthread_attr_getstacksize(3T), pthread_attr_setstacksize(3T).

STANDARDS CONFORMANCE

								  Pthread Library				  pthread_default_stacksize_np(3T)