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80 Commits

Author SHA1 Message Date
Stefan Metzmacher
407cda2f3b tevent: add support for TEVENT_FD_ERROR
After 12 years we finally got TEVENT_FD_ERROR support :-)

TEVENT_FD_WRITE event handlers never get errors reported
instead the event handler is silently disabled.
There are likely callers relying on that behavior, so
we are not able to chance it.

Now TEVENT_FD_WRITE can be used together with TEVENT_FD_ERROR
in order to get errors reported without waiting for TEVENT_FD_READ.

TEVENT_FD_ERROR can also be used alone in order to detect errors
on sockets in order to cleanup resources.

Signed-off-by: Stefan Metzmacher <metze@samba.org>
Reviewed-by: Ralph Boehme <slow@samba.org>
2023-10-13 09:49:33 +00:00
Stefan Metzmacher
b328e99065 tevent: add tevent_common_fd_mpx infrastructure
Backends may require to map individual tevent_fd instances to
a single low level kernel state (e.g. for epoll).

This generic infrastructure adds helper functions using
a generic (sub)part of struct tevent_fd.

The new code will allow us to support more than 2 tevent_fd
instances per fd, which makes sure all backends can provide
a similar behavior. This will be important when we add
TEVENT_FD_ERROR as a 3rd kind of fd event.

The aim is to use this in order to replace the limited implementation
we already have in tevent_epoll.c.

As these helpers are typically called from within
'void tevent_fd_set_flags(struct tevent_fd *fde, uint16_t flags)'
there's no way to report errors. So in order avoid additional
error handling complexity the helpers try to avoid
any allocations which may fail. It also means the logic in
tevent_epoll.c doesn't have to change much.

These are implemented as static line functions in order to avoid
the function call overhead, which showed up in profiles of the
early implementation.

Signed-off-by: Stefan Metzmacher <metze@samba.org>
Reviewed-by: Ralph Boehme <slow@samba.org>
2023-10-13 09:49:33 +00:00
Stefan Metzmacher
95d6600a06 tevent: split out a tevent_common_fd_disarm() helper
It means tevent_trace_fd_callback(TEVENT_EVENT_TRACE_DETACH)
is always called and similar future changes are only
needed in one place.

Signed-off-by: Stefan Metzmacher <metze@samba.org>
Reviewed-by: Ralph Boehme <slow@samba.org>
2023-10-13 09:49:33 +00:00
Stefan Metzmacher
0ddf8b5645 tevent: add tevent_common_fd_str() helper
Signed-off-by: Stefan Metzmacher <metze@samba.org>
Reviewed-by: Ralph Boehme <slow@samba.org>
2023-07-19 08:02:33 +00:00
Stefan Metzmacher
812313f1c8 tevent: add TEVENT_DEBUG() avoid argument overhead when log is not active...
It can be very costly to calculate the arguments passed to
tevent_debug(), just to drop the message within tevent_debug()
or the callback function.

So we add a way to avoid the overhead, it will be used in the
next commits.

Signed-off-by: Stefan Metzmacher <metze@samba.org>
Reviewed-by: Ralph Boehme <slow@samba.org>
2023-07-19 08:02:33 +00:00
Stefan Metzmacher
2c78a4f527 tevent: introduce tevent_set_max_debug_level() (default TEVENT_DEBUG_WARNING)
Allow an application to decide which log levels it wants to get
in the callback function passed to tevent_set_debug().

By default TEVENT_DEBUG_WARNING is the maximal reported level
and TEVENT_DEBUG_TRACE message no longer reach the callback function
by default.

It seems Samba is the only consumer of tevent_set_debug(), so it
should not be a huge problem, as Samba only reports TEVENT_DEBUG_TRACE
message with log level 50 anyway. And future Samba versions will
call tevent_set_max_debug_level() if needed.

Note the change to tevent-0.14.1.sigs will be reverted
with the release of tevent 0.15.0.

Signed-off-by: Stefan Metzmacher <metze@samba.org>
Reviewed-by: Ralph Boehme <slow@samba.org>
2023-07-19 08:02:33 +00:00
Pavel Filipenský
d7b29125c0 tevent: Flow: add tevent_thread_call_depth_set_callback()
Note the tevent-0.14.1.sigs changes will be reverted in
the 'tevent 0.15.0' commit.

Signed-off-by: Pavel Filipenský <pfilipensky@samba.org>
Reviewed-by: Stefan Metzmacher <metze@samba.org>
2023-07-19 08:02:33 +00:00
Stefan Metzmacher
0c4d6e630f tevent: Flow: store cleanup function name in tevent_req
Note the tevent-0.14.1.sigs changes will be reverted in
the 'tevent 0.15.0' commit.

Signed-off-by: Stefan Metzmacher <metze@samba.org>
Reviewed-by: Pavel Filipenský <pfilipensky@samba.org>
2023-07-19 08:02:33 +00:00
Stefan Metzmacher
85e43e70b2 tevent: Flow: store cancel function name in tevent_req
Note the tevent-0.14.1.sigs changes will be reverted in
the 'tevent 0.15.0' commit.

Signed-off-by: Stefan Metzmacher <metze@samba.org>
Reviewed-by: Pavel Filipenský <pfilipensky@samba.org>
2023-07-19 08:02:33 +00:00
Pavel Filipenský
deec9994eb tevent: Flow: store callback function name in tevent_req
Note the tevent-0.14.1.sigs changes will be reverted in
the 'tevent 0.15.0' commit.

Signed-off-by: Pavel Filipenský <pfilipensky@samba.org>
Reviewed-by: Stefan Metzmacher <metze@samba.org>
2023-07-19 08:02:33 +00:00
Pavel Filipenský
c5d5ebb60d tevent: Call depth tracking
The change to lib/tevent/ABI/tevent-0.13.0.sigs will be reverted
in the commit for the 0.14.0 release...

Signed-off-by: Pavel Filipenský <pfilipen@redhat.com>
Reviewed-by: Stefan Metzmacher <metze@samba.org>
Reviewed-by: Volker Lendecke <vl@samba.org>
2023-01-18 16:26:36 +00:00
Stefan Metzmacher
07251f562c tevent: expose tevent_find_ops_byname() to callers
This makes it more flexible and allow a caller to overload
a tevent backend. Which will be used by Samba in order to
glue in io_uring support.

Signed-off-by: Stefan Metzmacher <metze@samba.org>
Reviewed-by: Pavel Filipenský <pfilipen@redhat.com>
Reviewed-by: Volker Lendecke <vl@samba.org>
2023-01-18 16:26:36 +00:00
Stefan Metzmacher
147a317b7b tevent: remove solaris port backend
There's no way to verify changes we would have to do tevent_port.c,
as we don't have access to a solaris build machine.

So better use the poll backend instead. In performance critical code
we typically don't deal with a lot of file descriptors so the impact
should be fairly minimal.

Signed-off-by: Stefan Metzmacher <metze@samba.org>
Reviewed-by: Pavel Filipenský <pfilipen@redhat.com>
Reviewed-by: Volker Lendecke <vl@samba.org>
2023-01-18 16:26:36 +00:00
Pavel Filipenský
f681ef2ff4 tevent: Add tevent queue tracing support
Signed-off-by: Pavel Filipenský <pfilipen@redhat.com>
Reviewed-by: Stefan Metzmacher <metze@samba.org>
Reviewed-by: Andreas Schneider <asn@samba.org>
2022-04-11 16:56:35 +00:00
Pavel Filipenský
3198b94a2d tevent: Fix trailing whitespaces
Signed-off-by: Pavel Filipenský <pfilipen@redhat.com>
Reviewed-by: Stefan Metzmacher <metze@samba.org>
Reviewed-by: Andreas Schneider <asn@samba.org>
2022-04-11 16:56:35 +00:00
Pavel Březina
683c44a79f tevent: add event trace api
Adds new tracing API to trace fd, timer, signal and immediate events
on specific trace points: attach, before handler and dettach.

This can be used in combination with the event tag to keep track
of the currently executed event for purpose of debugging.

Pair-Programmed-With: Stefan Metzmacher <metze@samba.org>

Signed-off-by: Pavel Březina <pbrezina@redhat.com>
Signed-off-by: Stefan Metzmacher <metze@samba.org>
Reviewed-by: Andreas Schneider <asn@samba.org>
2021-07-07 05:07:30 +00:00
Pavel Březina
fc9dd8ce9f tevent: add custom tag to events
Adds a new API to set and get an uint64_t tag on fd, timer, signal and
immediate events. This can be used to assign a unique and known id to
the event to allow easy tracking of such event.

Pair-Programmed-With: Stefan Metzmacher <metze@samba.org>

Signed-off-by: Pavel Březina <pbrezina@redhat.com>
Signed-off-by: Stefan Metzmacher <metze@samba.org>
Reviewed-by: Andreas Schneider <asn@samba.org>
2021-07-07 05:07:30 +00:00
Volker Lendecke
3dae5061b5 tevent: Add tevent_req_profile
This allows detailed reporting where a tevent_req spends its time

Signed-off-by: Volker Lendecke <vl@samba.org>
Reviewed-by: Stefan Metzmacher <metze@samba.org>
2018-07-11 23:04:22 +02:00
Stefan Metzmacher
ac9569b1a6 tevent: add tevent_context_wrapper_create() infrastructure
This allows to specify wrapper tevent_contexts, which adds the ability
to run functions before and after the event handler functions.

This can be used to implement impersonation hooks
or advanced debugging/profiling hooks.

We'll undo the 0.9.36 ABI change on the 0.9.37 release
at the end of this patchset.

Signed-off-by: Stefan Metzmacher <metze@samba.org>
Reviewed-by: Ralph Boehme <slow@samba.org>
2018-07-11 23:04:21 +02:00
Stefan Metzmacher
072e3b28ce tevent: split out tevent_common_invoke_fd_handler()
We'll undo the 0.9.36 ABI change on the 0.9.37 release
at the end of this patchset.

Signed-off-by: Stefan Metzmacher <metze@samba.org>
Reviewed-by: Ralph Boehme <slow@samba.org>
2018-07-11 23:04:21 +02:00
Stefan Metzmacher
6740718e0e tevent: split out tevent_common_invoke_immediate_handler()
We'll undo the 0.9.36 ABI change on the 0.9.37 release
at the end of this patchset.

Signed-off-by: Stefan Metzmacher <metze@samba.org>
Reviewed-by: Ralph Boehme <slow@samba.org>
2018-07-11 23:04:20 +02:00
Stefan Metzmacher
a85ee852ac tevent: split out tevent_common_invoke_timer_handler()
As side effect this avoids tricks with an extra
tevent_common_timed_deny_destructor().

We'll undo the 0.9.36 ABI change on the 0.9.37 release
at the end of this patchset.

Signed-off-by: Stefan Metzmacher <metze@samba.org>
Reviewed-by: Ralph Boehme <slow@samba.org>
2018-07-11 23:04:20 +02:00
Stefan Metzmacher
ddab21987d tevent: split out tevent_common_invoke_signal_handler()
As side effect this avoids tricks with tevent_se_exists_destructor() to
figure out if the event handler removed itself.

We'll undo the 0.9.36 ABI change on the 0.9.37 release
at the end of this patchset.

Signed-off-by: Stefan Metzmacher <metze@samba.org>
Reviewed-by: Ralph Boehme <slow@samba.org>
2018-07-11 23:04:20 +02:00
Stefan Metzmacher
58fa08c805 tevent: add tevent_common_check_double_free() helper function
This will be used to generically support TALLOC_FREE() on
event which are currently running.

It aborts on every explicit talloc_free(), but ignores implicit
cleanup when the talloc parent is about to go.

We'll undo the 0.9.36 ABI change on the 0.9.37 release
at the end of this patchset.

Signed-off-by: Stefan Metzmacher <metze@samba.org>
Reviewed-by: Ralph Boehme <slow@samba.org>
2018-07-11 23:04:19 +02:00
Stefan Metzmacher
add485e47c tevent: make tevent_abort() available for backends
We'll undo the 0.9.36 ABI change on the 0.9.37 release
at the end of this patchset.

Signed-off-by: Stefan Metzmacher <metze@samba.org>
Reviewed-by: Ralph Boehme <slow@samba.org>
2018-07-11 23:04:18 +02:00
Stefan Metzmacher
f69bca61d5 tevent: rewrite/simplify tevent_poll and maintain ev->fd_events correctly
The following patches will rely on having all valid fd events in
ev->fd_events, even if they are temporary disabled with
tevent_set_fd_flags(fde, 0);

Signed-off-by: Stefan Metzmacher <metze@samba.org>
Reviewed-by: Ralph Boehme <slow@samba.org>
2018-07-11 23:04:17 +02:00
Jeremy Allison
993fa5793f lib: tevent: Minor cleanup. wakeup_fd can always be gotten from the event context.
We don't need to store it. I prefer this as it shows that we must always
get wakeup_fd from the event context at time of use, rather than possibly
storing an out-of-date variable.

Signed-off-by: Jeremy Allison <jra@samba.org>
Reviewed-by: Ralph Boehme <slow@samba.org>

Autobuild-User(master): Ralph Böhme <slow@samba.org>
Autobuild-Date(master): Fri Nov 17 12:43:01 CET 2017 on sn-devel-144
2017-11-17 12:43:01 +01:00
Jeremy Allison
2a003b1a57 lib: tevent: Remove select backend.
select() is no longer useful on modern systems.

Signed-off-by: Jeremy Allison <jra@samba.org>
Reviewed-by: Volker Lendecke <vl@samba.org>

Autobuild-User(master): Volker Lendecke <vl@samba.org>
Autobuild-Date(master): Sat Sep 16 08:35:39 CEST 2017 on sn-devel-144
2017-09-16 08:35:39 +02:00
Volker Lendecke
d5cc7be959 tevent: Make talloc_free safe when threaded_contexts exist
I did not find a way to do this safely without a mutex per threaded_context.

Signed-off-by: Volker Lendecke <vl@samba.org>
Reviewed-by: Jeremy Allison <jra@samba.org>
2016-10-05 00:06:21 +02:00
Volker Lendecke
5b3019cb91 tevent: Add tevent_common_wakeup_fd()
This prepares tevent run-down with active threads.

It has the advantage to not depend on talloc'ed structs. It is needed to make
talloc_free(tevent_context) safe when tevent_threaded_contexts are still
around.

Signed-off-by: Volker Lendecke <vl@samba.org>
Reviewed-by: Jeremy Allison <jra@samba.org>
2016-10-05 00:06:21 +02:00
Volker Lendecke
d90f325878 tevent: Rename wakeup fds
This makes the reading end of the signalling pipe special: If we have eventfd,
this is the same as the write fd. Without eventfd, it will have to be a
separate fd. This moves the requirement to #ifdef from the writing end to the
reading end. Why? We'll use the writing end somewhere else too soon, and this
patch avoids an #ifdef in that new place.

Signed-off-by: Volker Lendecke <vl@samba.org>
Reviewed-by: Jeremy Allison <jra@samba.org>
2016-10-05 00:06:21 +02:00
Volker Lendecke
c7e2cb839d tevent: Use eventfd for signal/thread wakeup
According to the manpage, eventfd is cheaper than a pipe. At least, we can save
a file descriptor and space for it in struct tevent_context :-)

Signed-off-by: Volker Lendecke <vl@samba.org>
Reviewed-by: Stefan Metzmacher <metze@samba.org>
Reviewed-by: Jeremy Allison <jra@samba.org>
2016-08-24 01:33:48 +02:00
Volker Lendecke
80cd6b7528 tevent: reorder tevent_context for cache locality
No functionality change. This just looks better in objdump --disassemble :-)

Signed-off-by: Volker Lendecke <vl@samba.org>
Reviewed-by: Stefan Metzmacher <metze@samba.org>
Reviewed-by: Jeremy Allison <jra@samba.org>
2016-08-24 01:33:48 +02:00
Volker Lendecke
f6aaece578 tevent: Add threaded immediate activation
This is infrastructure to improve our async r/w result handling and latency.
The pthreadpool signalling goes through a pipe. This has downsides: The main
event loop has to go through a read on the pipe before it can ship the result.
Also, it is not guaranteed by poll/epoll that the pthreadpool signal pipe is
handled with top priority. When an async pread/pwrite has finished, we should
immediately ship the result to the client, not waiting for anything else.

This patch enables tevent_immediate structs as job signalling. This means a
busy main tevent loop will handle the threaded job completion before any timed
or file descriptor events. Opposite to Jeremy's tevent_thread_proxy this is
done by a modification of the main event loop by looking at a linked list under
a central mutex.

Regarding performance: In a later commit I've created a test that does nothing
but fire one immediate over and over again. If you add a phread_mutex_lock and
unlock pair in the immediate handler, you lose roughly 25% of rounds per
second, so it is measurable. It is questionable that will be measurable in the
real world, but to counter concerns activation of immediates needs to go
through a new struct tevent_threaded_context. Only if such a
tevent_threaded_context exists for a tevent context, the main loop takes the
hit to look at the mutex'ed list of finished jobs.

This patch by design does not care about talloc hierarchies. The idea is that
the main thread owning the tevent context creates a chunk of memory and
prepares the tevent_immediate indication job completion. The main thread hands
the memory chunk together with the immediate as a job description over to a
helper thread. The helper thread does its job and upon completion calls
tevent_threaded_schedule_immediate with the already-prepared immediate. From
that point on memory ownership is again transferred to the main thread.

Signed-off-by: Volker Lendecke <vl@samba.org>
Reviewed-by: Stefan Metzmacher <metze@samba.org>
Reviewed-by: Jeremy Allison <jra@samba.org>
2016-08-24 01:33:48 +02:00
Volker Lendecke
8a9b8ac724 tevent: Move the async wakeup pipe to common
Signalling the main event loop will also happen from threads soon, and
that will use the same mechanism. This also keeps the pipe open after the last
signal handler is removed. Threaded jobs will come and go very frequently, and
always setting up and tearing down the pipe for each job will be expensive.
Also, this is "just" two file descriptors, and with eventfd just one.

Signed-off-by: Volker Lendecke <vl@samba.org>
Reviewed-by: Stefan Metzmacher <metze@samba.org>
Reviewed-by: Jeremy Allison <jra@samba.org>
2016-08-24 01:33:48 +02:00
Jeremy Allison
88c1eb4ae1 Add Solaris ports as a tevent backend.
Signed-off-by: Jeremy Allison <jra@samba.org>
Reviewed-by: David Disseldorp <ddiss@samba.org>

Autobuild-User(master): David Disseldorp <ddiss@samba.org>
Autobuild-Date(master): Sun Feb 15 23:25:07 CET 2015 on sn-devel-104
2015-02-15 23:25:07 +01:00
Stefan Metzmacher
50b9f154d2 tevent: add tevent_req_set_cleanup_fn()
Note that some callers used their own destructor for their
tevent_req instance, they'll just overwrite this,
which is not intended, but works without problems.

The intended way is to specify a cleanup function
and handle the TEVENT_REQ_RECEIVED state as destructor.

Note that the TEVENT_REQ_RECEIVED cleanup event might
be triggered by an explicit tevent_req_received()
in the _recv() function. The TEVENT_REQ_RECEIVED event
is only triggered once as tevent_req_received()
will remove the destructor.

So the difference compared to a custom destructor
is that the struct tevent_req itself can continue
to be there, while tevent_req_received() removed
all internal state.

Signed-off-by: Stefan Metzmacher <metze@samba.org>
Reviewed-by: Volker Lendecke <vl@samba.org>
2014-01-17 12:38:08 +01:00
Stefan Metzmacher
36345d44c8 tevent: tevent_epoll_set_panic_fallback() can be a void function
There's no case where this could return an error.

Signed-off-by: Stefan Metzmacher <metze@samba.org>
Reviewed-by: Volker Lendecke <vl@samba.org>
2013-12-11 22:46:09 +01:00
Stefan Metzmacher
35385a3e28 tevent: optimize adding new zero timer events
Such events were used before we had immediate events.
It's likely that there're a lot of this events
and we need to add new ones in fifo order.

The tricky part is that tevent_common_add_timer()
should not use the optimization as it's used
by broken Samba versions, which don't use
tevent_common_loop_timer_delay() in source3/lib/events.c.

Signed-off-by: Stefan Metzmacher <metze@samba.org>
Reviewed-by: Jeremy Allison <jra@samba.org>
2013-03-01 12:01:54 -08:00
Jeremy Allison
203f85c25e tevent: Add a private function tevent_poll_event_add_fd_internal().
Not yet used, but will be called by the "standard"
fallback from epoll -> poll backends.

Signed-off-by: Jeremy Allison <jra@samba.org>
Reviewed-by: Stefan Metzmacher <metze@samba.org>
2013-02-14 10:19:38 -08:00
Jeremy Allison
aceeb585cb tevent: Add a utility function tevent_find_ops_byname().
Returns an event ops struct given a string name. Not
yet used, but will be part of the new "standard" fallback
code.

Signed-off-by: Jeremy Allison <jra@samba.org>
Reviewed-by: Stefan Metzmacher <metze@samba.org>
2013-02-14 10:19:38 -08:00
Jeremy Allison
04ba47e491 tevent: Add an internal function tevent_epoll_set_panic_fallback().
Can be set externally, allows us to fallback if epoll
fails at runtime.

Signed-off-by: Jeremy Allison <jra@samba.org>
Reviewed-by: Stefan Metzmacher <metze@samba.org>
2013-02-14 10:19:38 -08:00
Volker Lendecke
fa71f32411 lib/tevent: Add a thread-safe tevent backend
Signed-off-by: Stefan Metzmacher <metze@samba.org>
2012-08-16 20:49:11 +02:00
Martin Schwenke
796acbd9ff lib/tevent: Add trace point callback
Set/get a single callback function to be invoked at various trace
points.  Define "before wait" and "after wait" trace points - more
trace points can be added later if required.

CTDB wants this to log long waits and events.

Pair-programmed-with: Amitay Isaacs <amitay@gmail.com>
Signed-off-by: Martin Schwenke <martin@meltin.net>
Signed-off-by: Stefan Metzmacher <metze@samba.org>
2012-06-08 19:00:05 +02:00
Stefan Metzmacher
e5827a4007 tevent: add tevent_req_defer_callback()
metze
2011-07-09 11:02:42 +02:00
Stefan Metzmacher
20284f2a84 tevent: change tevent_fd->additional_flags to uint64_t
metze
2011-03-10 09:37:02 +01:00
Volker Lendecke
3254e39220 tevent: Add a poll backend 2011-02-28 16:40:20 +01:00
Bo Yang
8c8bb51de1 s3: signals are processed twice in child.
Signed-off-by: Bo Yang <boyang@samba.org>
2010-02-09 17:05:58 +08:00
Volker Lendecke
4d8118f145 tevent: Fix a comment 2009-11-26 17:22:56 +01:00
Rusty Russell
be4ac22784 lib/tevent: handle tevent_common_add_signal on different event contexts.
I don't know if this is a problem in real life.

The code assumes there's only one tevent_context; all signals will notify
the first event context.  That's counter-intuitive if you ever use more
than one, and there's nothing else in this code which prevents it AFAICT.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2009-08-28 14:09:09 +10:00