[ST-users] problem of stack size in st_thread_create()

[Alfred Z. <alf...@gm...>]

Hi,
I am new to state thread library and am reading the source code of ST to
study implementation of threading.

in the st_thread_create() function

there is this code piece

if (stk_size == 0)
    stk_size = ST_DEFAULT_STACK_SIZE;  // I know this is to set the stack
size to a default size, if the input size is 0
  stk_size = ((stk_size + _ST_PAGE_SIZE - 1) / _ST_PAGE_SIZE) *
_ST_PAGE_SIZE; //what does this mean?

Look like it equals (stk_size + ST_PAGE_SIZE -1) unless the previous
division gives 0.

I am totally confused and can't find the answer in the code or the docs,
please help!

Thanks a lot!
Alfred