On MacOS X at least, pthread_attr_setstacksize(3) can fail
with EINVAL if 'stacksize' is not a multiple of the system
page size. Best to mention this so as to aid people writing
portable programs.
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Reported-by: Karsten Weiss <knweiss@gmail.com>
==
From: Karsten Weiss <knweiss@gmail.com>
Date: Fri, Oct 31, 2008 at 3:46 PM
Subject: pthread_create(3) - example bug + problems
[...]
A look in the pthread_set_stacksize man page on Mac revealed that on
Mac the stack size must not only be at least PTHREAD_STACK_MIN...
[...]
...but the new stack size must also be a multiple of the system page
size!
From pthread_attr_setstacksize(3):
pthread_attr_setstacksize() will fail if:
[EINVAL] Invalid value for attr.
[EINVAL] stacksize is less than PTHREAD_STACK_MIN.
!!! [EINVAL] stacksize is not a multiple of the system page size.
See for yourself (PTHREAD_STACK_MIN==8192 on Mac OS X):
$ ./pthread_test -s $((8192*10-1)) a
pthread_attr_setstacksize: Invalid argument
$ ./pthread_test -s $((8192*10)) a
Thread 1: top of stack near 0xb0014f6c; argv_string=a
Joined with thread 1; returned value was A
$ ./pthread_test -s $((8192*10+1)) a
pthread_attr_setstacksize: Invalid argument
Michael Kerrisk