This commit refactors the logic of workqueue processing delayed and periodic work, and changes the timer to be set in `work_thread`. The improvements of this change are as follows:
- Fixed the memory reuse problem of the original periodic workqueue implementation.
- By removing the `wdog_s` structure in the `work_s` structure, the memory overhead of each `work_s` structure is reduced by about 30 bytes.
- Set the timer for each workqueue instead of each work, which improves system performance.
- Simplified the workqueue cancel logic.
Signed-off-by: ouyangxiangzhen <ouyangxiangzhen@xiaomi.com>
In NuttX, the dq and the list are two different implementations of the double-linked list. Comparing to the dq, the list implementation has less branch conditions such as checking whether the head or tail is NULL. In theory and practice, the list is more friendly to the CPU pipeline. This commit changed the dq to the list in the wqueue implementation.
Signed-off-by: ouyangxiangzhen <ouyangxiangzhen@xiaomi.com>
reason:
We decouple semcount from business logic
by using an independent counting variable,
which allows us to remove critical sections in many cases.
Signed-off-by: hujun5 <hujun5@xiaomi.com>
Return 1 to indicate the work was not cancelled.
Because it is currently being processed by work thread,
but wait for it to finish.
Signed-off-by: ligd <liguiding1@xiaomi.com>
Most tools used for compliance and SBOM generation use SPDX identifiers
This change brings us a step closer to an easy SBOM generation.
Signed-off-by: Alin Jerpelea <alin.jerpelea@sony.com>
sched implementation not depends on macro abstraction, so revert below commit:
This reverts commit 4e62d0005a
This reverts commit 0f0c370520
This reverts commit ad0efd04ee
Signed-off-by: chao an <anchao@lixiang.com>
Decouple the semcount and the work queue length.
Previous Problem:
If a work is queued and cancelled in high priority threads (or queued
by timer and cancelled by another high priority thread) before
work_thread runs, the queue operation will mark work_thread as ready to
run, but the cancel operation minus the semcount back to -1 and makes
wqueue->q empty. Then the work_thread still runs, found empty queue,
and wait sem again, then semcount becomes -2 (being minused by 1)
This can be done multiple times, then semcount can become very small
value. Test case to produce incorrect semcount:
high_priority_task()
{
for (int i = 0; i < 10000; i++)
{
work_queue(LPWORK, &work, worker, NULL, 0);
work_cancel(LPWORK, &work);
usleep(1);
}
/* Now the g_lpwork.sem.semcount is a value near -10000 */
}
With incorrect semcount, any queue operation when the work_thread is
busy, will only increase semcount and push work into queue, but cannot
trigger work_thread (semcount is negative but work_thread is not
waiting), then there will be more and more works left in queue while
the work_thread is waiting sem and cannot call them.
Signed-off-by: Zhe Weng <wengzhe@xiaomi.com>
The number of work entries will be inconsistent with semaphore count
if the work is canceled, in extreme case, semaphore count will overflow
and fallback to 0 the workqueue will stop scheduling the enqueue work.
Signed-off-by: chao an <anchao@xiaomi.com>
include/nuttx/wqueue.h:
libs/libc/wqueue/work_cancel.c:
libs/libc/wqueue/work_queue.c:
sched/wqueue/kwork_cancel.c:
sched/wqueue/kwork_queue.c:
* Fix spelling, grammar, and typos.
* Improve wording in a few areas.
* These changes affect comments only. No functional changes.
