Commit Graph

21 Commits

Author SHA1 Message Date
Andy Ross 22642cf309 kernel: Clean up _unpend_thread() API
Almost everywhere this was called, it was immediately followed by
_abort_thread_timeout(), for obvious reasons.  The only exceptions
were in timeout and k_timer expiration (unifying these two would be
another good cleanup), which are peripheral parts of the scheduler and
can plausibly use a more "internal" API.

So make the common case the default, and expose the old behavior as
_unpend_thread_no_timeout().  (Along with identical changes for
_unpend_first_thread) Saves code bytes and simplifies scheduler
surface area for future synchronization work.

Signed-off-by: Andy Ross <andrew.j.ross@intel.com>
2018-04-24 03:57:20 +05:30
Andy Ross 15cb5d7293 kernel: Further unify _reschedule APIs
Now that other work has eliminated the two cases where we had to do a
reschedule "but yield even if we are cooperative", we can squash both
down to a single _reschedule() function which does almost exactly what
legacy _Swap() did, but wrapped as a proper scheduler API.

Signed-off-by: Andy Ross <andrew.j.ross@intel.com>
2018-04-24 03:57:20 +05:30
Andy Ross 0447a73f6c kernel: include cleanup
Recent changes have eliminated most use of _Swap() in favor of higher
level scheduler abstractions.  We can remove the header too.

Signed-off-by: Andy Ross <andrew.j.ross@intel.com>
2018-04-24 03:57:20 +05:30
Andy Ross e0a572beeb kernel: Refactor, unifying _pend_current_thread() + _Swap() idiom
Everywhere the current thread is pended, the code is going to have to
do a _Swap() soon afterward, yet the scheduler API exposed these as
separate steps.  Unify this pattern everywhere it appears, which saves
some code bytes and gets _Swap() out of the general scheduler API at
zero cost.

Signed-off-by: Andy Ross <andrew.j.ross@intel.com>
2018-04-24 03:57:20 +05:30
Andy Ross 8606fabf74 kernel: Scheduler refactoring: use _reschedule_*() always
There was a somewhat promiscuous pattern in the kernel where IPC
mechanisms would do something that might effect the current thread
choice, then check _must_switch_threads() (or occasionally
__must_switch_threads -- don't ask, the distinction is being replaced
by real English words), sometimes _is_in_isr() (but not always, even
in contexts where that looks like it would be a mistake), and then
call _Swap() if everything is OK, otherwise releasing the irq_lock().
Sometimes this was done directly, sometimes via the inverted test,
sometimes (poll, heh) by doing the test when the thread state was
modified and then needlessly passing the result up the call stack to
the point of the _Swap().

And some places were just calling _reschedule_threads(), which did all
this already.

Unify all this madness.  The old _reschedule_threads() function has
split into two variants: _reschedule_yield() and
_reschedule_noyield().  The latter is the "normal" one that respects
the cooperative priority of the current thread (i.e. it won't switch
out even if there is a higher priority thread ready -- the current
thread has to pend itself first), the former is used in the handful of
places where code was doing a swap unconditionally, just to preserve
precise behavior across the refactor.  I'm not at all convinced it
should exist...

Signed-off-by: Andy Ross <andrew.j.ross@intel.com>
2018-04-24 03:57:20 +05:30
Andy Ross 85bc0a3fe6 kernel: Cleanup, unify _add_thread_to_ready_q() and _ready_thread()
The scheduler exposed two APIs to do the same thing:
_add_thread_to_ready_q() was a low level primitive that in most cases
was wrapped by _ready_thread(), which also (1) checks that the thread
_is_ready() or exits, (2) flags the thread as "started" to handle the
case of a thread running for the first time out of a waitq timeout,
and (3) signals a logger event.

As it turns out, all existing usage was already checking case #1.
Case #2 can be better handled in the timeout resume path instead of on
every call.  And case #3 was probably wrong to have been skipping
anyway (there were paths that could make a thread runnable without
logging).

Now _add_thread_to_ready_q() is an internal scheduler API, as it
probably always should have been.

This also moves some asserts from the inline _ready_thread() wrapper
to the underlying true function for code size reasons, otherwise the
extra use of the inline added by this patch blows past code size
limits on Quark D2000.

Signed-off-by: Andy Ross <andrew.j.ross@intel.com>
2018-03-18 16:58:12 -04:00
Leandro Pereira a1ae8453f7 kernel: Name of static functions should not begin with an underscore
Names that begin with an underscore are reserved by the C standard.
This patch does not change names of functions defined and implemented
in header files.

Signed-off-by: Leandro Pereira <leandro.pereira@intel.com>
2018-03-10 08:39:10 -05:00
Andy Ross 245b54ed56 kernel/include: Missed nano_internal.h -> kernel_internal.h spots
Update heading naming given recent rename

Signed-off-by: Andy Ross <andrew.j.ross@intel.com>
2018-02-16 10:44:29 -05:00
Andy Ross 9c62cc677d kernel: Add kswap.h header to unbreak cycles
The xtensa-asm2 work included a patch that added nano_internal.h
includes in lots of places that needed to have _Swap defined, because
it had to break a cycle and this no longer got pulled in from the arch
headers.

Unfortunately those new includes created new and more amusing cycles
elsewhere which led to breakage on other platforms.

Break out the _Swap definition (only) into a separate header and use
that instead.  Cleaner.  Seems not to have any more hidden gotchas.

Signed-off-by: Andy Ross <andrew.j.ross@intel.com>
2018-02-16 10:44:29 -05:00
Andy Ross 32a444c54e kernel: Fix nano_internal.h inclusion
_Swap() is defined in nano_internal.h.  Everything calls _Swap().
Pretty much nothing that called _Swap() included nano_internal.h,
expecting it to be picked up automatically through other headers (as
it happened, from the kernel arch-specific include file).  A new
_Swap() is going to need some other symbols in the inline definition,
so I needed to break that cycle.  Now nothing sees _Swap() defined
anymore.  Put nano_internal.h everywhere it's needed.

Our kernel includes remain a big awful yucky mess.  This makes things
more correct but no less ugly.  Needs cleanup.

Signed-off-by: Andy Ross <andrew.j.ross@intel.com>
2018-02-16 10:44:29 -05:00
Luiz Augusto von Dentz 8786244ebc poll: Update code comments to reflect latest changes
It is now possible to poll event if there is another thread polling.

Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
2017-11-21 06:54:51 -05:00
Luiz Augusto von Dentz fc775a095c poll: k_poll: Return -EINTR if not ready
In case _handle_obj_poll_events is called with K_POLL_STATE_NOT_READY
set -EINTR as return to the poller thread.

Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
2017-10-18 13:02:52 -04:00
Luiz Augusto von Dentz 7d01c5ecb7 poll: Enable multiple threads to use k_poll in the same object
This is necessary in order for k_queue_get to work properly since that
is used with buffer pools which might be used by multiple threads asking
for buffers.

Jira: ZEP-2553

Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
2017-08-25 09:00:46 -04:00
Kumar Gala cc334c7273 Convert remaining code to using newly introduced integer sized types
Convert code to use u{8,16,32,64}_t and s{8,16,32,64}_t instead of C99
integer types.  This handles the remaining includes and kernel, plus
touching up various points that we skipped because of include
dependancies.  We also convert the PRI printf formatters in the arch
code over to normal formatters.

Jira: ZEP-2051

Change-Id: Iecbb12601a3ee4ea936fd7ddea37788a645b08b0
Signed-off-by: Kumar Gala <kumar.gala@linaro.org>
2017-04-21 11:38:23 -05:00
Luiz Augusto von Dentz e5ed88f328 fifo: Make use of k_queue as implementation
This makes k_fifo functions rely on k_queue and port k_poll to use
k_queue directly.

Once all users of k_fifo migrate to k_queue this should no longer be
needed.

Change-Id: Icf16d580f88d11b2cb89e1abd23ae314f43dbd20
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
2017-02-27 21:20:52 +00:00
Benjamin Walsh 3c1ab5d338 kernel/poll: fix signal.signaled not being set when k_poll() waits
Change-Id: I73d906e4cb4a3d359e1ec193db933a95b4739611
Signed-off-by: Benjamin Walsh <walsh.benj@gmail.com>
2017-02-09 23:54:27 +00:00
Benjamin Walsh 2014ff162e kernel/poll: fix registrations that were not always cleared
Poll events were getting registered even when polling conditions had
already been met, but events with conditions met did not register and
did not increment the number of events registered. This caused a
possible discrepancy between the number of events registered and the
position of the last event registered in the events array.

As soon as one event condition is met, the next ones in the array should
not get registered even if their condition is not met. This is what the
code does now.

Change-Id: Ibcc3b135ec9d3cf463beb9da3f641fec962b34bf
Signed-off-by: Benjamin Walsh <walsh.benj@gmail.com>
2017-02-09 23:54:26 +00:00
Benjamin Walsh 47503e30b2 kernel/poll: refactor is_polling()
It's always called for the current thread.

Change-Id: I6588ae27505e961df5cf82463ca9be90a539685b
Signed-off-by: Benjamin Walsh <walsh.benj@gmail.com>
2017-02-09 23:54:25 +00:00
Benjamin Walsh a304f16773 kernel/poll: add k_poll_signal_init() runtime init
Change-Id: Id5a27f7d25e26a1a71ef87000d35a18777210c19
Signed-off-by: Benjamin Walsh <walsh.benj@gmail.com>
2017-02-03 13:54:01 +00:00
Benjamin Walsh 969d4a7ff1 kernel/poll: add user tag to struct k_poll_event
This will allow users to install a way of finding out what the event and
the objects are used for without looking at the object itself, or to
tag a bunch of objects that belong together.

The runtime init function _does not_ take a tag so that there is no
runtime hit if not needed. The static initializer macro _does_ take the
tag, so that it does not have to be initialized at runtime if needed,
and thus avoids a runtime hit.

Change-Id: I89a36c6f969ff952f9d1673b1bb5136e407535c6
Signed-off-by: Benjamin Walsh <walsh.benj@gmail.com>
2017-02-03 13:53:59 +00:00
Benjamin Walsh acc68c1e59 kernel: add k_poll() API
k_poll() is similar to the POSIX poll() API in spirit in that it allows
a single thread to monitor multiple events without actively polling
them, but rather pending for one or more to become ready. Such events
can be a direct event, or kernel objects (currently only semaphores and
fifos).

When a kernel object being polled on is ready, it is not "given" to the
poller: the poller must then acquire it via the regular API for the
object (e.g. k_sem_take()). Only one thread can poll on a particular
object at one time. These restrictions mean that k_poll() is most
effective when a single thread monitors multiple events that are not
subject for contention. For example, being the sole reader on multiple
fifos, or the only thread being signalled by multiple semaphores, or a
combination of both.

Change-Id: I7035a9baf4aa016fb87afc5f5c0f5f8cb216480f
Signed-off-by: Benjamin Walsh <walsh.benj@gmail.com>
2017-02-02 00:30:00 +00:00