OK, I will take a look at this as soon as possible BR, ChengDong
Alan C. Assis <[email protected]> 于2026年2月6日周五 00:50写道： > Hi Mathias, > > Thank you for finding and reporting this issue. I'm CC Chengdong here. > > Chengdong, could you please take a look at this issue? > > BR, > > Alan > > On Thu, Feb 5, 2026 at 12:32 PM <[email protected]> wrote: > > > > > Hello, > > > > I have problems with the following commit, which is part of PR #17199 > > > > commit c7b6442974545b92476615ef048633609d828e5b > > Author: wangchengdong <[email protected]> > > Date: Mon Oct 13 20:57:43 2025 +0800 > > sched/clock: Improve CLOCK_MONOTONIC nxclock_gettime() > > > > Improve nxclock_gettime(), to get the system time excluding > > the time that the system is suspended, when the clockid is > > CLOCK_MONOTONIC > > > > Signed-off-by: Chengdong Wang [email protected] > > > > > > > > This commit changes the behaviour of CLOCK_MONOTONIC. It is running > slower > > than CLOCK_BOOTTIME now. > > > > I called sem_clockwait() with CLOCK_MONOTONIC, but the "if" in line 143 > in > > nuttx/sched/semaphore/sem_clockwait.c handles on two cases. I used > > CLOCK_MONOTONIC to calculate the value "abstime", but wd_start_abstime() > > uses CLOCK_BOOTTIME now. When the system in running for some time this > > leads to an immediate timeout, because two different clocks are compared. > > > > > > int nxsem_clockwait(FAR sem_t *sem, clockid_t clockid, > > FAR const struct timespec *abstime) > > { > > ... > > if (clockid == CLOCK_REALTIME) > > { > > wd_start_realtime(&rtcb->waitdog, abstime, > > nxsem_timeout, (uintptr_t)rtcb); > > } > > else > > { > > wd_start_abstime(&rtcb->waitdog, abstime, > > nxsem_timeout, (uintptr_t)rtcb); > > } > > ... > > > > > > > > For my understanding the change of CLOCK_MONOTONIC is not correct. > > According to the POSIX definition > > https://pubs.opengroup.org/onlinepubs/9799919799/ it must be a > > "system-wide monotonic clock", CLOCK_BOOTTIME is not defined here. > > > > > > On the other hand, if such a low level change is made, all usages should > > be reviewed. There a lot of places where CLOCK_MONOTONIC is used in the > > nuttx source code. And there are places like in nxsem_clockwait() where > the > > change leads to an error even though CLOCK_MONOTONIC is not used in the > > code. > > > > > > What do you think? > > > > BR, > > Mathias > > >
