ProsperoRadio (PPSA99001) stops at 33.7 s on Windows, with #3649
applied so that it gets past poll, on the throw from #3840:
what(): fcntl: record locks are not implemented on Windows, command=12, fd=3
F_GETLK, F_SETLK, F_SETLKW and the F_OGETLK, F_OSETLK and F_OSETLKW
forms now follow FreeBSD 11.4's kern_fcntl and lf_advlockasync
(8c639945): an SEEK_CUR start is resolved against the descriptor offset
(EOVERFLOW past OFF_MAX), F_RDLCK needs read access and F_WRLCK write
access (EBADF), another type is EINVAL, and the range is checked against
the file size for SEEK_END (EINVAL for a negative start or an unknown
whence, EOVERFLOW past OFF_MAX). The guest is one process, and
lf_blocks never lets locks of one owner conflict, so whichever
descriptor or thread asks, F_SETLK and F_SETLKW succeed without waiting
and F_GETLK reports F_UNLCK, as on the console. Nothing is held on the
host: Windows byte-range locks are mandatory and would fail the guest's
own reads and writes through other descriptors. A lock from the end of
a directory throws.
Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
fcntl and sceKernelFcntl read a third argument as a 64-bit integer for
every command on a non-socket descriptor. F_GETFD and F_GETFL pass no
third argument, and the commands that take one pass an int or a pointer.
They now read nothing, an int or a pointer, by command. An int read as
a 64-bit value kept whatever the caller left in the upper half of the
register, so F_READAHEAD -1 enabled read-ahead instead of disabling it.
ioctl and _ioctl answered EBADF for every descriptor outside the
libSceNet socket table. Decoded call sites: PS5MC (PPSA99420, FIONBIO x3,
FIONREAD x2, TIOCGWINSZ x3), ProsperoTV (PPSA99003, FIONBIO on a pipe
once poll on pipes is in), XPSemu (PPSA97358, 21 sites).
Following FreeBSD 11.4 kern_ioctl (sys/kern/sys_generic.c:758),
vn_ioctl (sys/kern/vfs_vnops.c:1488), pipe_ioctl (sys/kern/sys_pipe.c:1346)
and randomdev_ioctl (sys/dev/random/randomdev.c:301), release/11.4.0
8c639945: FIONBIO sets or clears O_NONBLOCK through the same status
flags as fcntl F_SETFL (EFAULT for a null argument before EBADF);
FIONREAD reports the size past the offset of a file, the queued bytes of
a pipe's read end, 0 on its write end, ENOTTY on the random device, and
throws on a directory or another character device; termios requests
(group 't', TIOCGWINSZ included) fail with ENOTTY, as tcgetattr already
takes these descriptors as not a terminal; any other request throws
naming the request and descriptor kind. Sockets keep their path
unchanged.
Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
fcntl and sceKernelFcntl answered EBADF (sceKernelFcntl threw) for
every descriptor outside the libSceNet socket table, so files, pipes,
directories and descriptors 0 to 2 could not be queried or changed.
Observed: Yamagi Quake II (PPSA99007) stops with
"Sys_Error: change stdin to blocking Bad file descriptor", from
fcntl(fileno(stdin), F_SETFL, fcntl(0, F_GETFL, 0) & ~FNDELAY)
(yquake2 src/backends/unix/system.c:81-86).
Predicted from the titles' sources and decoded call sites: XPSemu
(PPSA97358, 97 fcntl sites: F_GETFD 12, F_SETFD 20, F_GETFL 8,
F_SETFL 9, F_DUPFD 1, F_DUPFD_CLOEXEC 7, F_GETLK 9) fails in
qemu_init_main_loop, where its pipe2 (pipe plus F_SETFD FD_CLOEXEC) and
glib's g_unix_set_fd_nonblocking (F_GETFL, F_SETFL) build the event
notifier (util/event_notifier-posix.c:44-67); VLC (PPSA85300, 43 sites,
F_RDAHEAD on every file it opens), RetroArch (PPSA99169, 17),
Porpoise (PPSA99764, 13) and Ruffle (9) call it on files and pipes.
The commands follow FreeBSD 11.4 kern_fcntl and kern_dup
(sys/kern/kern_descrip.c:479-799, 812, release/11.4.0 8c639945):
F_GETFD/F_SETFD keep the close-on-exec flag per descriptor, F_GETFL
reports the host access mode with the status flags, F_SETFL changes
only O_NONBLOCK, O_APPEND, O_ASYNC, O_FSYNC, O_DIRECT and FRDAHEAD,
F_DUPFD/F_DUPFD_CLOEXEC give the lowest free descriptor at or above the
start through dup (EINVAL for a negative start), F_DUP2FD goes through
dup2, F_RDAHEAD/F_READAHEAD set FRDAHEAD on files (EBADF on pipes,
ENOTTY elsewhere), and unknown commands fail with EINVAL. Status flags
live in a guest table shared by dup, dup2 and F_DUPFD like an open file
description. O_NONBLOCK switches a pipe (PIPE_NOWAIT on Windows, where an
empty read and a full write now report EAGAIN; the host flag on Linux).
Record locks use the host POSIX locks on Linux and throw on Windows.
Changes the host cannot model throw naming the flag and descriptor kind.
Sockets keep their path unchanged.
Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
screamm
Ahir
David