pyconfig.h
omnia neo
I am working on porting python on vxworks and hence was updating the PC
\pyconfig.h file for configurng python. As I am reading the file and
updating manually I come across lot many preprocessor directives which
I dont understand e.g. HAVE_NICE etc. May be this is standard
nomenclature and I am not aware of it.
My point and qwery is that how can I get info about all these
directives. I am perplexed to enable or disable any of them with half
knowledge.
regards,
Martin v. Loewis
See the main pyconfig.h.in for comments when to define each of these
macros. HAVE_NICE should be defined if you have (i.e. your system has)
the nice() function.
Regards,
Martin
NICE(P) POSIX Programmer's Manual NICE(P)
NAME
nice - change the nice value of a process
SYNOPSIS
#include <unistd.h>
int nice(int incr);
DESCRIPTION
The nice() function shall add the value of incr to the nice
value of the calling process. A process' nice value is a non-
negative number for which a more positive value shall result
in less favorable scheduling.
A maximum nice value of 2*{NZERO}-1 and a minimum nice value
of 0 shall be imposed by the system. Requests for values above
or below these limits shall result in the nice value being set
to the corresponding limit. Only a process with appropriate
privileges can lower the nice value.
Calling the nice() function has no effect on the priority of
processes or threads with policy SCHED_FIFO or SCHED_RR. The
effect on processes or threads with other scheduling policies
is implementation-defined.
The nice value set with nice() shall be applied to the
process. If the process is multi-threaded, the nice value
shall affect all system scope threads in the process.
As -1 is a permissible return value in a successful situation,
an application wishing to check for error situations should
set errno to 0, then call nice(), and if it returns -1, check
to see whether errno is non-zero.
RETURN VALUE
Upon successful completion, nice() shall return the new nice
value -{NZERO}. Otherwise, -1 shall be returned, the process'
nice value shall not be changed, and errno shall be set to
indicate the error.
indicate the error.
ERRORS
The nice() function shall fail if:
EPERM The incr argument is negative and the calling process
does not have appropriate privileges.
The following sections are informative.
EXAMPLES
Changing the Nice Value
The following example adds the value of the incr argument,
-20, to the nice value of the calling process.
#include <unistd.h>
...
int incr = -20;
int ret;
ret = nice(incr);
APPLICATION USAGE
None.
RATIONALE
None.
FUTURE DIRECTIONS
None.
SEE ALSO
getpriority() , setpriority() , the Base Definitions volume of
IEEE Std 1003.1-2001, <limits.h>, <unistd.h>
COPYRIGHT
Portions of this text are reprinted and reproduced in elec‐
tronic form from IEEE Std 1003.1, 2003 Edition, Standard for
Information Technology -- Portable Operating System Interface
(POSIX), The Open Group Base Specifications Issue 6, Copyright
(C) 2001-2003 by the Institute of Electrical and Electronics
Engineers, Inc and The Open Group. In the event of any dis‐
crepancy between this version and the original IEEE and The
Open Group Standard, the original IEEE and The Open Group
Standard is the referee document. The original Standard can be
obtained online at http://www.opengroup.org/unix/online.html .
IEEE/The Open Group 2003 NICE(P)