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>
This is an implementation of pthread barriers pursuant to the relevant specification.
Barriers are essentially a special case of conditional variables,
such that all threads waiting on one are woken up when the number of
waiters reaches a number provided at the initialization of the barrier.
In view of that, this implementation mimics the implementation of pthread_cond,
except it is more specialized and self-contained.
Signed-off-by: Jérôme Duval <jerome.duval@gmail.com>
* No need for the atomically changed variables to be declared as
volatile.
* Drop support for atomically getting and setting unaligned data.
* Introduce atomic_get_and_set[64]() which works the same as
atomic_set[64]() used to. atomic_set[64]() does not return the
previous value anymore.
* Added the aforementioned functions.
* create_area_etc() now takes a guard size parameter.
* The thread_info::stack_base/end range now refers to the usable range
only.
* Reorganized the kernel locking related to threads and teams.
* We now discriminate correctly between process and thread signals. Signal
handlers have been moved to teams. Fixes#5679.
* Implemented real-time signal support, including signal queuing, SA_SIGINFO
support, sigqueue(), sigwaitinfo(), sigtimedwait(), waitid(), and the addition
of the real-time signal range. Closes#1935 and #2695.
* Gave SIGBUS a separate signal number. Fixes#6704.
* Implemented <time.h> clock and timer support, and fixed/completed alarm() and
[set]itimer(). Closes#5682.
* Implemented support for thread cancellation. Closes#5686.
* Moved send_signal() from <signal.h> to <OS.h>. Fixes#7554.
* Lots over smaller more or less related changes.
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@42116 a95241bf-73f2-0310-859d-f6bbb57e9c96
* Therefore, all pthread functions should now work fine on all threads.
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@33967 a95241bf-73f2-0310-859d-f6bbb57e9c96
