>Number:         30970
>Category:       lib
>Synopsis:       Invalid return values for POSIX RT sched_ functions
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    lib-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Thu Aug 11 08:25:00 +0000 2005
>Originator:     Ian Zagorskih
>Release:        NetBSD-current
>Organization:
NGEDC
>Environment:
NetBSD IANZAG 3.99.7 NetBSD 3.99.7 (IANZAG-ACPI) #2: Wed Jul 27 14:03:25 NOVST 2005  ianzag@IANZAG:/home/ianzag/NetBSD/kernel/IANZAG-ACPI i386

>Description:
Accordint to POSIX RT specification, sched_ functions should return -1 and set errno value to ENOSYS when function is not implemented:

http://www.opengroup.org/onlinepubs/009695399/functions/sched_setparam.html

---cut---
RETURN VALUE

    If successful, the sched_setparam() function shall return zero.

    If the call to sched_setparam() is unsuccessful, the priority shall remain unchanged, and the function shall return a value of -1 and set errno to indicate the error.
---cut---

Same time sched_ functions in NetBSD return ENOSYS instead of -1 and leaves errno value unchanged. This behaviour can confuse applications which explicitely test return values on -1.

>How-To-Repeat:

less /usr/src/lib/libpthread/sched.c

>Fix:

Just return -1 and set errno value to ENOSYS.