Commit graph

11 commits

Author SHA1 Message Date
Flavio Ceolin
d9aa414831 kernel: work_q: Add an init function
k_work_queue_start receives a struct that is expected to be
uninitialized (zeroed). Otherwise the behavior is undefined.

Following the Zephyr semantics, this pr introduce a new init function
for this struct.

Fixes #36865

Signed-off-by: Flavio Ceolin <flavio.ceolin@intel.com>
2021-08-25 22:07:04 -04:00
Maksim Masalski
8ed9cddbc5 lib: add explanation comment in "work->handler" case
Coding scanning tool raises a violation that happens dereferencing
of the "work" pointer in the expression "work->handler"

As were discussed before in PR #35664 it is not true.
Add explanation comment, because static code analysis tool
raised false-positive violation there.

Signed-off-by: Maksim Masalski <maksim.masalski@intel.com>
2021-08-20 18:48:16 -04:00
Peter Bigot
656c09589a kernel: work: fix race condition with cancel before work runs
The original state management solution involved separate locks for a
work queue and each work item.  To avoid inter-lock dependencies a
window was left between the point where the work item was removed from
the queue (protected by queue lock) and the point where the work item
state was updated to mark the work item running.

This introduced a bug: If a cancellation was issued during this window
it would succeed, and the work item would appear to be idle even
though in fact the work queue thread was about to run it.

Since there is now only one lock, move the work item state updates
into the mutex regions associated with dequeuing the work item and
clearing the work queue busy flag.

Note that removing the window between queue and work mutex regions
eliminates the potential of having a dequeued work item be cancelled
before its QUEUED flag is cleared, simplifying the work item state
update.

Signed-off-by: Peter Bigot <peter.bigot@nordicsemi.no>
2021-05-18 15:02:08 +02:00
Torbjörn Leksell
7a646b3f8e Tracing: Work Queue tracing
Add Work tracing, default tracing hooks, and documentation.

Signed-off-by: Torbjörn Leksell <torbjorn.leksell@percepio.com>
Signed-off-by: Anas Nashif <anas.nashif@intel.com>
2021-05-07 22:10:21 -04:00
Guennadi Liakhovetski
d7a3752915 work: remove a statement with no effect
work_timeout() is a function, a statement like "(void)work_timeout;"
has no effect.

Signed-off-by: Guennadi Liakhovetski <guennadi.liakhovetski@linux.intel.com>
2021-05-07 12:44:34 -04:00
Daniel Leung
c8177ace3a kernel: work: handler null check is to NULL...
...instead of numeric zero.

Current usage is violation of MISRA rule 11.9.

Signed-off-by: Daniel Leung <daniel.leung@intel.com>
2021-04-29 07:16:37 -04:00
Jennifer Williams
9aa0f212ae kernel: work: fix missing final else
work_queue_main() was missing final else statement
in the if else if construct. This commit adds else {}
to comply with coding guideline 15.7. Includes a
context-specific description of why this branch is empty.

Signed-off-by: Jennifer Williams <jennifer.m.williams@intel.com>
2021-04-27 17:31:59 -04:00
Peter Bigot
707dc22fb0 kernel: fix error in synchronous work cancellation return value
The return value is documented to be true if the work was pending, but
the implementation returned true only if the work was actually running
(i.e. the caller had to wait).  It should also return true if
scheduled or submitted work was cancelled.

Note that this means the return value cannot be used to determine
whether the call slept.

Signed-off-by: Peter Bigot <peter.bigot@nordicsemi.no>
2021-04-27 13:28:45 -04:00
Anas Nashif
bbbc38ba8f kernel: Make both operands of operators of same essential type category
Add a 'U' suffix to values when computing and comparing against
unsigned variables and other related fixes of the same MISRA rule (10.4)

Signed-off-by: Anas Nashif <anas.nashif@intel.com>
2021-04-01 05:34:17 -04:00
Peter Bigot
fed035231f kernel: work: fix schedule from running work
k_work_schedule() is supposed to be a no-op if the work item is
already scheduled or submitted: the previous schedule is left
unchanged.  The check incorrectly inhibited the schedule operation
when the work item was neither scheduled nor submitted, but was
running.

Signed-off-by: Peter Bigot <peter.bigot@nordicsemi.no>
2021-03-29 12:27:36 -04:00
Peter Bigot
dc34e7c6f6 kernel: add new work queue implementation
This commit provides a complete reimplementation of the work queue
infrastructure intended to eliminate the race conditions and feature
gaps in the existing implementation.

Both bare and delayable work structures are supported.  Items can be
submitted; delayable items can be scheduled for submission at a future
time.  Items can be delayed, queued, and running all at the same time.
A running item can also be canceling.

The new implementation:
* replaces "pending" with "busy" which identifies the active states;
* supports canceling delayed and submitted items;
* prevents resubmission of a item being canceled until cancellation
  completes;
* supports waiting for cancellation to complete;
* supports flushing a work item (waiting for the last submission to
  complete without preventing resubmission);
* supports waiting for a queue to drain (only allows resubmission from
  the work thread);
* supports stopping a work queue in conjunction with draining it;
* prevents handler-reentrancy during resubmission.

Signed-off-by: Peter Bigot <peter.bigot@nordicsemi.no>
2021-03-03 20:06:00 -05:00