nuttx/include
dongjiuzhu1 3c486b98dd fs/timerfd: implement TFD_TIMER_CANCEL_ON_SET to detect clock changes
Implement Linux-compatible TFD_TIMER_CANCEL_ON_SET flag for timerfd to
allow applications to detect discontinuous changes to CLOCK_REALTIME.

Background:
According to Linux timerfd_create(2) man page, when a timerfd is created
with CLOCK_REALTIME and TFD_TIMER_CANCEL_ON_SET flag is specified, the
read() operation should fail with ECANCELED if the real-time clock
undergoes a discontinuous change. This allows applications to detect
and respond to system time changes.

Implementation:
1. Add clock notifier infrastructure (clock_notifier.h/c) to notify
   interested parties when system time changes
2. Implement TFD_TIMER_CANCEL_ON_SET flag support in timerfd
3. Register timerfd with clock notifier when flag is set
4. Cancel timer and return ECANCELED when clock change is detected
5. Notify clock changes in:
   - clock_settime()
   - clock_initialize()
   - clock_timekeeping_set_wall_time()
   - rpmsg_rtc time synchronization

Changes include:
- New files: include/nuttx/clock_notifier.h, sched/clock/clock_notifier.c
- Modified: fs/vfs/fs_timerfd.c to handle TFD_TIMER_CANCEL_ON_SET
- Modified: clock subsystem to call notifier chain on time changes
- Modified: rpmsg_rtc to notify time changes during sync

Use case example:
Applications using timerfd with absolute time can now detect when
system time is adjusted (e.g., NTP sync, manual time change) and
take appropriate action such as recalculating timeouts or updating
scheduled events.

Reference: https://man7.org/linux/man-pages/man2/timerfd_create.2.html

Signed-off-by: dongjiuzhu1 <dongjiuzhu1@xiaomi.com>
2026-01-30 17:20:24 +08:00
..
android
arpa
crypto crypto: support software key management based on MTD 2026-01-28 11:52:12 +08:00
cxx cxx/cstddef: expose 'max_align_t' 2025-12-09 18:03:10 +08:00
net net/ethernet: change struct ifreq to consistent with Linux 2025-12-27 20:34:17 +08:00
netinet netinet/in.h: Rename imr_interface to imr_address in struct ip_mreqn. 2026-01-16 09:42:12 +08:00
netpacket net/packet: add PACKET_<ADD|DROP>_MEMBERSHIP support 2025-12-25 10:01:43 +08:00
nuttx fs/timerfd: implement TFD_TIMER_CANCEL_ON_SET to detect clock changes 2026-01-30 17:20:24 +08:00
ssp
sys fs/timerfd: implement TFD_TIMER_CANCEL_ON_SET to detect clock changes 2026-01-30 17:20:24 +08:00
.gitignore
aio.h
alloca.h
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debug.h drivers/rptun: add rptun debug config macros and Kconfig 2026-01-19 14:18:27 +08:00
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imx_container.h arch/arm64/imx9: Add ROMAPI and AHAB support for i.MX9 2025-05-09 19:21:17 +08:00
inttypes.h inttype.h: add PRIuTM(time_t) to handle TIME64 & TIME32 print compatible 2025-12-01 10:07:49 +01:00
iso646.h
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limits.h limits: add _POSIX_PTHREAD_ constant for pthread management 2026-01-16 16:15:35 +08:00
locale.h style/FAR: remove FAR qualifier 2025-11-10 10:56:29 +01:00
lzf.h
malloc.h
mqueue.h [POSIX][Bug] mqueue.h: Include file does not conform the standard 2024-12-09 21:21:09 +08:00
netdb.h
nl_types.h
nxflat.h
obstack.h
poll.h
pthread.h libc/pthread: Avoid compiler optimizations for once_control->done 2026-01-22 19:47:45 +08:00
pty.h
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sched.h sched: remove csection and reduce the interrupt disabling time in sched_[un]lock 2025-01-23 19:58:49 +08:00
search.h LICENSE: update NuttX-PublicDomain SPDX identifier 2025-12-26 19:46:12 +08:00
semaphore.h sched/semaphore: add support to customize semaphore max allowed value 2025-09-04 09:48:34 +08:00
shadow.h
signal.h sched/timer: Fix MISRA Rule 10.4 2026-01-22 22:14:00 +08:00
spawn.h libc/spawn:support get/set priority 2026-01-26 21:01:01 +08:00
stdbool.h
stddef.h arm64_head.S: fix the asm code build error 2026-01-13 21:20:52 +08:00
stdint.h arm64_head.S: fix the asm code build error 2026-01-13 21:20:52 +08:00
stdio.h stdio.h: Update TMP_MAX definition to match Linux. 2026-01-14 17:28:30 -08:00
stdlib.h include/stdlib.h: define system()'s prototype for the flat build 2025-02-07 09:03:14 +08:00
stdnoreturn.h
string.h string:use builtin function to optimize libc function 2025-12-20 10:38:53 +08:00
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syscall.h
syslog.h drivers/syslog: Add RFC 5424 protocol support 2025-06-13 20:26:57 +08:00
termios.h include: modify for support socat, so need add some macro same as linux 2025-12-10 23:44:14 +08:00
threads.h include/threads.h: Replace thrd_ defines by actual function definitions 2024-12-19 21:56:02 +08:00
time.h
ulimit.h ulimit: add ulimit implementation 2026-01-16 10:03:53 +08:00
unistd.h fpathconf: add _POSIX_PRIO_IO defintion 2026-01-15 16:10:51 -03:00
utime.h
uuid.h
wait.h wait: add wait.h header file 2024-12-20 11:46:14 -03:00
wchar.h fix misspelled names in locally scoped code 2025-05-15 10:12:12 +08:00
wctype.h