Implemented against POSIX-1.2013.
The implementation POSIX requirement thats setpriority() shall affect the
priority of all system scope threads only extends to POSIX threads. This
is implemented by modifying the default attributes for newly spawned
pthreads.
It is not possible to modify the default pthread attributes for different
processes with the current implementation, as default pthread attributes
are implemented in user-space. As a result, PRIO_PROCESS for which and 0
for who is the only supported combination for setpriority().
While it is possible to move the default attributes to the kernel, it
is chosen not to so as to keep the pthread implementation user-space only.
POSIX requires that lowering the nice value (increasing priority) can be
done only by processes with appropriate privileges. However, as Haiku
currently doesn't harbor any restrictions in setting the thread priority,
this is not implemented.
It is possible to have small precision errors when converting from Unix-
style thread priority to Be-style. For example, the following program
outputs "17" instead of the expected "18":
#include <stdio.h>
#include <sys/resource.h>
int
main()
{
setpriority(PRIO_PROCESS, 0, 18);
printf("%d\n", getpriority(PRIO_PROCESS, 0));
return 0;
}
The underlying reason is because when you setpriority() both 18 and 19
are converted to the Be-style "2". This problem should not happen with
priority levels lower than or equal to 20, when the Be notation is more
precise than the Unix-style.
Done as a part of GCI 2014. Fixes#2817.
Signed-off-by: Timothy Gu <timothygu99@gmail.com>
Co-authored-by: Leorize <leorize+oss@disroot.org>
Change-Id: Ie14f105b00fe8563d16b3562748e1c2e56c873a6
Reviewed-on: https://review.haiku-os.org/c/78
Reviewed-by: Jérôme Duval <jerome.duval@gmail.com>
Reviewed-by: waddlesplash <waddlesplash@gmail.com>
Cleaned up some header style violations, making sure there are two blank lines after the header guards.
This fixes the posix header part of #2191.
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@39288 a95241bf-73f2-0310-859d-f6bbb57e9c96
and types.h. The idea is to provide a basic architecture/compiler
abstraction by defining types and macros that allow the posix/ and os/
headers to be mostly architecture/compiler agnostic.
* Adjusted the posix/ and os/ headers accordingly.
* <SupportDefs.h>: Introduced B_PRI* and B_SCN* macros similar to the PRI*
and SCN* macros defined in <inttypes.h>, just for the BeOS/Haiku [u]int*
types and some POSIX types (e.g. off_t, dev_t, ino_t) that don't have POSIX
macros. Also the B_PRI* and B_SCN* macros are available unconditionally,
unlike the <inttypes.h> macros, which require __STDC_FORMAT_MACROS to be
defined in C++ mode.
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@34214 a95241bf-73f2-0310-859d-f6bbb57e9c96
Replaced single-line comments by multi-line comments for ANSI C
compliance.
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@25433 a95241bf-73f2-0310-859d-f6bbb57e9c96
and used that one and NOFILE to implement R5 private calls _kset_[fd|mon]_limit_()
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@17545 a95241bf-73f2-0310-859d-f6bbb57e9c96
