kevent threw NotImplemented for EVFILT_WRITE with NOTE_LOWAT above 1 on a socket, although the socket readiness check already reports free send-buffer space (SO_SNDBUF less SIOCOUTQ on Linux). The write event now fires once that space reaches the mark, as FreeBSD 11's filt_sowrite compares sbspace with kn_sdata, and stays silent while the space is below it. The debt entry no longer says a write mark is limited to 1. Reference: https://github.com/freebsd/freebsd-src/blob/release/11.0.0/sys/kern/uipc_socket.c
kevent threw for EVFILT_WRITE on any descriptor that is not a socket. On the write end of a pipe it now follows FreeBSD 11's filt_pipewrite: data is the free buffer space, and once the read end is closed the event reports EV_EOF with data 0. Adding the event after the read end is closed fails with EPIPE, as in pipe_kqfilter. EVFILT_WRITE on the read end still throws, because FreeBSD's pipe ends are bidirectional and host pipes are not.
An EV_CLEAR read knote on a pipe fires once per write and reports EV_EOF with no data once the write end closes. Combined with EV_DISPATCH it reports once and disables itself; EV_ENABLE re-runs the filter as kqueue_register does, so data that arrived while disabled is reported, and an enable with nothing buffered reports nothing.
An EV_CLEAR write knote fires once when added to a writable socket, stays quiet after the guest's own send, fires again when the peer drains the data and frees the send space, fires on a fresh EV_ADD, and reports EV_EOF when the peer closes.
On a Unix stream socketpair an EV_CLEAR read knote fires once per arrival with the full byte count, stays quiet while data sits unread, without the wait spinning on the readable socket, fires again when re-added, is dropped when an arrival was read before the next scan, wakes a blocking kevent, and reports EV_EOF once when the peer closes.
kevent threw for EV_CLEAR on a socket or the read end of a pipe; Boost.Asio's kqueue reactor, among others, registers every socket that way. On Linux such a knote now watches its host descriptor through an edge watch. It is armed when added, on every later EV_ADD or EV_ENABLE while enabled, and by each host wakeup; when armed it is checked with the level-triggered readiness test and reported with the current data and EV_EOF, or disarmed if no longer ready, as kqueue_scan re-runs the filter; reporting it disarms it until the next edge. Waits block on the watch's epoll descriptor, so a socket that stays readable does not wake them. Windows and macOS still throw. GuestSockets::NativeDescriptor exposes the host socket behind a guest one for the watch.
PipeRead (guest_kqueue) and the blocking read in guest_socket_events took
their start time after creating the thread that writes after 50 ms, so a
main thread preempted between the two measured less than the writer's
sleep and failed the 40 ms check although the wait did block until the
write.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
PPSA34015 (EA SPORTS FC 27) registers EVFILT_READ for descriptor 0 in a
new kqueue at start-up, ignores the result, and stopped with "kevent:
EVFILT_READ on a non-socket descriptor not implemented". A read event on
the host stream on descriptor 0 is now accepted and never triggers, as
select never reports descriptor 0 readable.
On Linux, FIONREAD on a datagram socket reports the next datagram only,
where FreeBSD's sbavail counts every queued byte, so a read mark above 1
there could never fire. kevent now throws for it as before; stream
sockets and marks of 1 are unchanged.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
kevent threw for NOTE_LOWAT. On a socket's EVFILT_READ it now sets the
low-water mark as FreeBSD 11's filt_soread does: the event fires once the
buffered bytes reach it, or at end of file or on a listening socket, and
a later change of the knote replaces it. EVFILT_WRITE takes a mark of 1,
where the host's writability stands in for a free byte; other write marks
and marks below 1 still throw. A pipe ignores the mark, as filt_piperead
does.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
On a Unix stream socketpair the write event's data drops by at least the bytes sent while the peer has not read them, and comes back to the idle value once the peer drains them. Off Linux the test only checks that the value stays positive and never grows.
An elevated Windows process can bypass the parent directory DACL while holding SeBackupPrivilege or SeRestorePrivilege. Remove both privileges before DeniedParentWatch so the test exercises the denied-open path reliably.
Co-Authored-By: Adam Franke <10361523+frankea@users.noreply.github.com>
kevent threw for any descriptor that is not a guest socket. The read end
of a pipe now gets the descriptor knote, following FreeBSD 11's
filt_piperead: data is the number of buffered bytes and EV_EOF is set
once the write end is closed. GuestSockets::Ready falls back to the new
PipeReadState for a descriptor that is not a socket, and WaitAny waits on
the pipe with ppoll on Linux or in 1 ms WSAPoll slices on Windows, only
when the queue holds a pipe. On Windows the equeue waker now starts
Winsock itself, since a queue can wait on a pipe before any socket exists.
On a new knote EV_FORCEONESHOT is dropped from the flags; on an
existing one it sets EV_ONESHOT and fires the knote, as
kqueue_register does at l.1339-1341. A modify no longer ORs
EV_ONESHOT, EV_CLEAR or EV_DISPATCH into the knote.
Generated with [Devin](https://devin.ai)
Co-Authored-By: Devin <158243242+devin-ai-integration[bot]@users.noreply.github.com>
A knote registered or modified with EV_DISABLE stays registered but is
not polled, fired or reported until an EV_ENABLE change re-arms it, as
kern_event.c does with KN_DISABLED. EV_DISPATCH reports an event once
and then disables the knote, and EV_FORCEONESHOT registers as oneshot.
A negative nevents fails with EINVAL instead of throwing.
Generated with [Devin](https://devin.ai)
Co-Authored-By: Devin <158243242+devin-ai-integration[bot]@users.noreply.github.com>
DeniedParentWatch denied FILE_LIST_DIRECTORY to the name GetUserNameW
returns. When the user name equals the computer name, LookupAccountNameW
resolves that bare name to the computer's domain SID (SidTypeDomain), so
the deny entry matched no one, the parent watch was allowed and the test
aborted on an empty error. The entry now names the SID of the process
token's user.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
The Windows error for a refused FindFirstChangeNotification was one string shared
by WatchParent and WatchContents, so the log could not tell which handle or path
was denied. Build it from the watcher, the path the API was given and
GetLastError instead.
Still throws: the EVFILT_VNODE attach path is vfs_kqfilter, which returns only
EINVAL, ENOMEM or 0, with EBADF from fget before it, and consults no directory
permission, so no FreeBSD errno stands for a host that refuses to notify.
Windows 10 1903 deletes a file with open handles by moving it into
$Extend\$Deleted until the last handle closes, so the next snapshot of a
watched file that a title (or the test) deleted saw a new path, tried to
watch that directory's changes, got ERROR_ACCESS_DENIED and threw from
the watch thread, which aborts the process; the path change was also
reported as NOTE_RENAME next to NOTE_DELETE. A snapshot with a pending
delete or no links now reports NOTE_DELETE alone and drops the parent
directory watch instead of replacing it, as the file has no directory
to be renamed or removed from any more.
inotify queues IN_MOVED_FROM and IN_MOVED_TO of a rename one after the
other. The watcher thread could read the first before the second was
queued and report a rename inside the directory as a move to another
directory (NOTE_WRITE | NOTE_EXTEND instead of NOTE_WRITE), which made
guest_kqueue abort on loaded runners.
The watcher now reads the queue until it is empty and, when a move half
has no partner, calls getdents64 on the directory before reading again:
that takes the directory lock rename holds until both halves are queued.
Cloudberry Kingdom (PPSA23827, #3177) registers its first kevent change
as a file watch: ident 3, EVFILT_VNODE, flags 0x25
(EV_ADD|EV_ENABLE|EV_CLEAR), fflags 0x37
(NOTE_DELETE|WRITE|EXTEND|LINK|RENAME). Palworld's Discord module
(PPSA23126, #2648) imports sceKernelAddFileEvent and
sceKernelDeleteFileEvent, which no library exported.
EVFILT_VNODE watches the host file or directory behind the descriptor
and turns host changes into FreeBSD 11 vnode hints, added whole when
they share a bit with the requested fflags as filt_vfsvnode does
(sys/kern/vfs_subr.c, release/11.0.1 34bd3475): a growing write is
NOTE_WRITE|NOTE_EXTEND, a shrinking truncate or an attribute change
NOTE_ATTRIB, a link count change NOTE_LINK or NOTE_DELETE, a pending
delete NOTE_DELETE, a new path NOTE_RENAME, and in a directory a new,
removed or renamed entry NOTE_WRITE (with NOTE_LINK for a subdirectory,
as vop_mkdir_post/vop_rmdir_post). Windows uses FindFirstChangeNotification
on the parent directory (and the watched directory) and compares handle
snapshots every 50 ms, since a write through an open handle is not
reported until it is flushed or closed (measured); Linux uses inotify.
Closing the descriptor, deleting the event or the queue stops the
watcher.
sceKernelAddFileEvent(eq, fd, watch, udata) and
sceKernelDeleteFileEvent(eq, fd) take the OpenOrbis 0a1aaf9d
(libkernel.h:35,109) and SharpProspero 5dfdb4b0 (KernelEqueue.cs:164,168)
signatures; NIDs cG3t15OK4Ow and UmXngHKB6is confirmed with
tools/nid_names.py. The watch bits are the fflags and the event is added
with EV_CLEAR, which is not confirmed on a title.
Throws: NOTE_REVOKE, NOTE_OPEN, NOTE_CLOSE, NOTE_CLOSE_WRITE, NOTE_READ
and unknown bits, NOTE_EXTEND on a directory on Windows (a move from
another directory cannot be told from a creation) and descriptors that
are not files, directories, pipes or sockets (pipes, sockets and kqueues
fail with EINVAL as in FreeBSD). Recorded in TechnicalDebt.
guest_kqueue adds a vnode watch that sees a write to a temporary file
with Cloudberry's flags, fflags filtering, a re-registration, the sce
pair on an equeue, EINVAL for sockets, pipes and the kqueue itself, the
close of a watched descriptor and a directory watch.
Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
Cloudberry Kingdom (PPSA23827, #3177) calls kqueue right after start-up
and stopped on the throwing declarations merged with #3337; Palworld's
Discord module (PPSA23126, #2648) imports kevent.
kqueue reserves a host null-device descriptor in the file descriptor
space and registers it as an event queue that reports each ready event
once per call and moves level-triggered ones behind the others, as
kqueue_scan does. close and sceKernelClose close the queue and drop the
descriptor's events from every queue, dup2 drops them for the target,
and dup/dup2 of a kqueue throw, so a reused descriptor number is never
read as a stale kqueue.
kevent follows FreeBSD 11 kern_event.c (release/11.0.1 34bd3475):
kqueue_kevent for the changelist (filter 0 skipped, EV_SYSFLAGS
cleared, EV_ERROR receipts with the errno in data, EV_RECEIPT, the
early return when nevents is exhausted), kqueue_register for EV_ADD,
EV_DELETE, EV_ENABLE, EBADF, ENOENT and EINVAL, kqueue_scan for the
timeout (EINVAL for a bad timespec, zero polls, above INT32_MAX waits
forever) and filt_timerattach, filt_usertouch for the timer and user
filters. Read and write events reuse the guest socket poll of
sceKernelAddReadEvent/WriteEvent.
Throws: other filters, EV_DISABLE, EV_DISPATCH, EV_FORCEONESHOT,
NOTE_LOWAT, EV_CLEAR on a socket, read/write events on non-socket
descriptors or another kqueue, changes to an existing timer (11.0 and
11.4 differ), a NOTE_NSECONDS fraction above one second and a negative
nevents. Recorded in TechnicalDebt.
Test guest_kqueue covers creation and close, timers, a user event
triggered from another thread, read and write events on a socket pair,
EV_ERROR receipts, the timeout and the error cases.
Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
Federico Marras