Commit Graph

20 Commits

Author SHA1 Message Date
Flavio Ceolin ea716bf023 kernel: Explicitly comparing pointer with NULL
MISRA-C rule: 14.4

Signed-off-by: Flavio Ceolin <flavio.ceolin@intel.com>
2018-09-28 06:28:41 +05:30
Findlay Feng 3c834bdf27 kernel: Fix list-node add again corruption case in timeout handling
The node of the timeout temporary list cannot be continued
to index the next node after being added again.

Signed-off-by: Findlay Feng <i@fengch.me>
2018-09-21 13:29:09 -04:00
Flavio Ceolin a7fffa9e00 headers: Fix headers guards
Any word started with underscore followed by and uppercase letter or a
second underscore is a reserved word according with C99.

With have *many* violations on Zephyr's code, this commit is tackling
only the violations caused by headers guards. It also takes the
opportunity to normalize them using the filename in uppercase and
replacing dot with underscore. e.g file.h -> FILE_H

Signed-off-by: Flavio Ceolin <flavio.ceolin@intel.com>
2018-09-17 15:49:26 -04:00
Andy Ross d8d5ec3f91 kernel: Fix double-list-removal corruption case in timeout handling
This fixes #8669, and is distressingly subtle for a one-line patch:

The list iteration code in _handle_expired_timeouts() would remove the
timeout from our (temporary -- the dlist header is on the stack of our
calling function) list of expired timeouts before invoking the
handler.  But sys_dlist_remove() only fixes up the containing list
pointers, leaving garbage in the node.  If the action of that handler
is to re-add the timeout (which is very common!) then that will then
try to remove it AGAIN from the same list.

Even then, the common case is that the expired list contains only one
item, so the result is a perfectly valid empty list that affects
nothing.  But if you have more than one, you get a corrupt cycle in
the iteration list and things get weird.

As it happens, there's no value in trying to remove this timeout from
the temporary list at all.  Just iterate over it naturally.

Really, this design is fragile: we shouldn't be reusing the list nodes
in struct _timeout for this purpose and should figure out some other
mechanism.  But this fix should be good for now.

Signed-off-by: Andy Ross <andrew.j.ross@intel.com>
2018-08-26 19:39:52 -07:00
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 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
Anas Nashif 780324b8ed cleanup: rename fiber/task -> thread
We still have many places talking about tasks and threads, replace those
with thread terminology.

Signed-off-by: Anas Nashif <anas.nashif@intel.com>
2017-10-30 18:41:15 -04:00
Youvedeep Singh d787e3c554 timer: k_timer_start should accept 0 as duration parameter.
k_timer_start(timer, duration, period) is API used to
start a timer. Currently duration parameters accepts
only positive number.
But a user may require to do some periodic activity
ASAP and start timer with 0 value. So this patch
allows 0 as minimum value of duration.
In this patch, when duration value is set as 0 then
timer expiration handler is called instead of submiting
this into timeout queue.

Jira: ZEP-2497

Signed-off-by: Youvedeep Singh <youvedeep.singh@intel.com>
2017-09-06 10:18:39 -07:00
Luiz Augusto von Dentz 87aa621915 kernel: Use SYS_DLIST_FOR_EACH_CONTAINER whenever possible
SYS_DLIST_FOR_EACH_CONTAINER is preferable over using
SYS_DLIST_FOR_EACH_NODE as that avoid casting directly which assumes the
node field is always at the beginning.

Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
2017-08-25 09:08:50 -04:00
Ramesh Thomas 89ffd44dfb kernel: tickless: Add tickless kernel support
Adds event based scheduling logic to the kernel. Updates
management of timeouts, timers, idling etc. based on
time tracked at events rather than periodic ticks. Provides
interfaces for timers to announce and get next timer expiry
based on kernel scheduling decisions involving time slicing
of threads, timeouts and idling. Uses wall time units instead
of ticks in all scheduling activities.

The implementation involves changes in the following areas

1. Management of time in wall units like ms/us instead of ticks
The existing implementation already had an option to configure
number of ticks in a second. The new implementation builds on
top of that feature and provides option to set the size of the
scheduling granurality to mili seconds or micro seconds. This
allows most of the current implementation to be reused. Due to
this re-use and co-existence with tick based kernel, the names
of variables may contain the word "tick". However, in the
tickless kernel implementation, it represents the currently
configured time unit, which would be be mili seconds or
micro seconds. The APIs that take time as a parameter are not
impacted and they continue to pass time in mili seconds.

2. Timers would not be programmed in periodic mode
generating ticks. Instead they would be programmed in one
shot mode to generate events at the time the kernel scheduler
needs to gain control for its scheduling activities like
timers, timeouts, time slicing, idling etc.

3. The scheduler provides interfaces that the timer drivers
use to announce elapsed time and get the next time the scheduler
needs a timer event. It is possible that the scheduler may not
need another timer event, in which case the system would wait
for a non-timer event to wake it up if it is idling.

4. New APIs are defined to be implemented by timer drivers. Also
they need to handler timer events differently. These changes
have been done in the HPET timer driver. In future other timers
that support tickles kernel should implement these APIs as well.
These APIs are to re-program the timer, update and announce
elapsed time.

5. Philosopher and timer_api applications have been enabled to
test tickless kernel. Separate configuration files are created
which define the necessary CONFIG flags. Run these apps using
following command
make pristine && make BOARD=qemu_x86 CONF_FILE=prj_tickless.conf qemu

Jira: ZEP-339 ZEP-1946 ZEP-948
Change-Id: I7d950c31bf1ff929a9066fad42c2f0559a2e5983
Signed-off-by: Ramesh Thomas <ramesh.thomas@intel.com>
2017-04-27 13:46:28 +00:00
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
Kumar Gala 34a57db844 Revert "kernel: Convert formatter strings to use PRI defines"
This reverts commit 7b9dc107a8.

We revert this as we intent to move away from {u}int{8,16,32,64}_t types
to our own internal types for sized variables so we shouldn't need the
PRI macros anymore.

Change-Id: I1d9d797fee47ca266867ae65656c150f8fe2adb2
Signed-off-by: Kumar Gala <kumar.gala@linaro.org>
2017-04-19 10:50:51 -05:00
Anas Nashif 306e15e0a1 kernel: remove legacy kernel support
Change-Id: Iac1e21677d74f81a93cd29d64cce261676ae78a6
Signed-off-by: Anas Nashif <anas.nashif@intel.com>
2017-04-19 15:48:37 +00:00
Kumar Gala 7b9dc107a8 kernel: Convert formatter strings to use PRI defines
To allow for various libc implementations (like newlib) in which the way
various {u}int{8,16,32}_t types are defined vary between both libc
implementations and across architectures we need to utilize the PRI
defines.

Change-Id: Ie884fb67015502288152ecbd64c37961a4f538e4
Signed-off-by: Kumar Gala <kumar.gala@linaro.org>
2017-04-17 11:09:36 -05:00
Benjamin Walsh 5d35dba73d kernel/timeouts: add description of timeouts queued on the same tick
Change-Id: I24ba889e3174b903ccea5309ad45e2b4d1755fe1
Signed-off-by: Benjamin Walsh <walsh.benj@gmail.com>
2017-02-16 04:56:25 +00:00
Luiz Augusto von Dentz 41921dd5b9 kernel: Use SYS_DLIST_FOR_EACH_CONTAINER
Change-Id: I4cbb12af487217cfcb78969ec88a8e4c06eca27f
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
2017-02-10 16:16:14 +00:00
David B. Kinder ac74d8b652 license: Replace Apache boilerplate with SPDX tag
Replace the existing Apache 2.0 boilerplate header with an SPDX tag
throughout the zephyr code tree. This patch was generated via a
script run over the master branch.

Also updated doc/porting/application.rst that had a dependency on
line numbers in a literal include.

Manually updated subsys/logging/sys_log.c that had a malformed
header in the original file.  Also cleanup several cases that already
had a SPDX tag and we either got a duplicate or missed updating.

Jira: ZEP-1457

Change-Id: I6131a1d4ee0e58f5b938300c2d2fc77d2e69572c
Signed-off-by: David B. Kinder <david.b.kinder@intel.com>
Signed-off-by: Kumar Gala <kumar.gala@linaro.org>
2017-01-19 03:50:58 +00:00
Benjamin Walsh 66b99f1486 kernel: add _timeout_q dump before and after adding timeout
Kernel debugging aid.

Change-Id: I852ba2f626f133d943be2ecac41354fecca478d6
Signed-off-by: Benjamin Walsh <benjamin.walsh@windriver.com>
2017-01-06 17:32:27 +00:00
Benjamin Walsh 99eef25815 kernel: do not use sys_dlist_insert_at() in _add_timeout()
Similar to _pend_queue, it's more efficient to do the logic inline.

Change-Id: I68ac4fbc26c97b6ec9322caef98504ff6ccc8727
Signed-off-by: Benjamin Walsh <benjamin.walsh@windriver.com>
2017-01-06 17:32:26 +00:00
Anas Nashif d687a95611 kernel: move kernel code to kernel/ directly
Also remove mentions of unified kernel in various places in the kernel,
samples and documentation.

Change-Id: Ice43bc73badbe7e14bae40fd6f2a302f6528a77d
Signed-off-by: Anas Nashif <anas.nashif@intel.com>
2016-12-19 14:59:35 -05:00