Seems none of the applications I tested yesterday actually used poll(),
because it was completely broken by this.
The previous code assigned this variable inside a malloc() call, though,
which wasn't all that obvious either.
* otherwise the signal to be handled might be blocked. fixes#15193
* also remove automatic syscall restart on _kern_select, to match Linux and
BSDs behavior: this fixes parallel build with newer gnu make, which happens
to use pselect.
* also remove automatic syscall restart on _kern_poll.
from https://man7.org/linux/man-pages/man7/signal.7.html
"The following interfaces are never restarted after being
interrupted by a signal handler, regardless of the use of
SA_RESTART; they always fail with the error EINTR when
interrupted by a signal handler: ...
select(2), and pselect(2)."
from https://notes.shichao.io/unp/ch6/
"Berkeley-derived kernels never automatically restart select."
Change-Id: I3e9488f60c966b38d427f992f06e6e2217d4adc5
Reviewed-on: https://review.haiku-os.org/c/haiku/+/3636
Reviewed-by: Jérôme Duval <[email protected]>
Reviewed-by: Axel Dörfler <[email protected]>
* otherwise the signal to be handled might be blocked. fixes#15193
* also remove automatic syscall restart on _kern_select, to match Linux and
BSDs behavior: this fixes parallel build with newer gnu make, which happens
to use pselect.
* also remove automatic syscall restart on _kern_poll.
from https://man7.org/linux/man-pages/man7/signal.7.html
"The following interfaces are never restarted after being
interrupted by a signal handler, regardless of the use of
SA_RESTART; they always fail with the error EINTR when
interrupted by a signal handler: ...
select(2), and pselect(2)."
from https://notes.shichao.io/unp/ch6/
"Berkeley-derived kernels never automatically restart select."
Change-Id: I7f86d221eae1ad93d8a308a75581d2c30a369c9e
Reviewed-on: https://review.haiku-os.org/c/haiku/+/3627
Reviewed-by: Adrien Destugues <[email protected]>
Reviewed-by: waddlesplash <[email protected]>
Since wait_for_objects can wait on sems, threads and ports in addition
to FDs, limiting to RLIMIT_NOFILES as in the select/poll case does not
work. Since space is allocated for the wait objects in kernel memory,
limiting their number to a valid range is still desireable.
The limit is now placed at the sum of max sem, thread and port count
plus RLIMIT_NOFILES.
This also fixes a signed vs. unsigned comparison warning in
check_max_fds introduced in hrev51866.
occurred. This fixes the automatic syscall restart case (would wait forever)
and aligns the behavior with poll().
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@35948 a95241bf-73f2-0310-859d-f6bbb57e9c96
* Always select POLLNVAL. We wouldn't get notified, if the FD was closed while
waiting.
* Skip negative FDs (as per POSIX standard).
* When encountering an invalid FD, we must not wait. Previously we did that as
long as any FD was valid.
* The return count must consider all FDs with non-null revents, including
invalid ones (revents is POLLNVAL then).
common_poll()/common_wait_for_objects():
* Don't bail out early, when no FDs/objects have been selected. We always want
to wait.
_user_poll()/_user_wait_for_objects():
* Copy the array back to userland even if common_*() returned an error. The
functions do now always fill in the resulting events.
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@32418 a95241bf-73f2-0310-859d-f6bbb57e9c96
* Replaced the use of offsetof() for structs that aren't PODs. Add a
offset_of_member() macro to util/khash.h because that's what it's used for
in our cases.
* Change the signature of add_debugger_command()/remove_debugger_command() on
GCC > 2 to avoid the depricated conversion from string constants to char *.
* Adding some "suggested" parenthesis. I know that not everyone likes that, but
it pointed out at least one bug that is fixed here as well.
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@29113 a95241bf-73f2-0310-859d-f6bbb57e9c96
the selecting thread, which has obviously no effect.
* Changed select_info::events to vint32. It is now updated atomically.
This removes a race condition when concurrent threads would notify at
the same time.
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@25273 a95241bf-73f2-0310-859d-f6bbb57e9c96
timeout, not just -1. Paranoia only, since that should happen anyway.
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@24082 a95241bf-73f2-0310-859d-f6bbb57e9c96
* Implemented automatic syscall restarts:
- A syscall can indicate that it has been interrupted and can be
restarted by setting a respective bit in thread::flags. It can
store parameters it wants to be preserved for the restart in
thread::syscall_restart::parameters. Another thread::flags bit
indicates whether it has been restarted.
- handle_signals() clears the restart flag, if the handled signal
has a handler function installed and SA_RESTART is not set. Another
thread flag (THREAD_FLAGS_DONT_RESTART_SYSCALL) can prevent syscalls
from being restarted, even if they could be (not used yet, but we
might want to use it in resume_thread(), so that we stay
behaviorally compatible with BeOS).
- The architecture specific syscall handler restarts the syscall, if
the restart flag is set. Implemented for x86 only.
- Added some support functions in the private <syscall_restart.h> to
simplify the syscall restart code in the syscalls.
- Adjusted all syscalls that can potentially be restarted accordingly.
- _user_ioctl() sets new thread flag THREAD_FLAGS_IOCTL_SYSCALL while
calling the underlying FS's/driver's hook, so that syscall restarts
can also be supported there.
* thread_at_kernel_exit() invokes handle_signals() in a loop now, as
long as the latter indicates that the thread shall be suspended, so
that after waking up signals received in the meantime will be handled
before the thread returns to userland. Adjusted handle_signals()
accordingly -- when encountering a suspending signal we don't check
for further signals.
* Fixed sigsuspend(): Suspending the thread and rescheduling doesn't
result in the correct behavior. Instead we employ a temporary
condition variable and interruptably wait on it. The POSIX test
suite test passes, now.
* Made the switch_sem[_etc]() behavior on interruption consistent.
Depending on when the signal arrived (before the call or when already
waiting) the first semaphore would or wouldn't be released. Now we
consistently release it.
* Refactored _user_{read,write}[v]() syscalls. Use a common function for
either pair. The iovec version doesn't fail anymore, if anything could
be read/written at all. It also checks whether a complete vector
could be read/written, so that we won't skip data, if the underlying
FS/driver couldn't read/write more ATM.
* Some refactoring in the x86 syscall handler: The int 99 and sysenter
handlers use a common subroutine to avoid code duplication.
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@23983 a95241bf-73f2-0310-859d-f6bbb57e9c96
vfs_select.h, respectively moved most of it into the new kernel
private header wait_for_objects.h.
* Added new experimental API functions wait_for_objects[_etc](). They
work pretty much like poll(), but also for semaphores, ports, and
threads.
* Removed the "ref" parameter from notify_select_events() and the
select_sync_pool functions as well as from fd_ops::fd_[de]select(). It
is no longer needed. The FS interface select() hook still has it,
though -- the VFS will always pass 0.
* de]select_fd() take a select_info* instead of a select_sync* + ref
pair, now. Added respective functions for semaphores, ports, and
threads.
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@22416 a95241bf-73f2-0310-859d-f6bbb57e9c96
Augustin Cavalier