From: Alejandro Colomar Date: Wed, 28 May 2025 20:05:12 +0000 (+0200) Subject: man/man2/futex.2, man/man2const/FUTEX_FD.2const: Split FUTEX_FD from futex(2) X-Git-Tag: man-pages-6.15~43^2~22 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=8a9849bd2cc614ddf805b9fef2fed0db33d341bf;p=thirdparty%2Fman-pages.git man/man2/futex.2, man/man2const/FUTEX_FD.2const: Split FUTEX_FD from futex(2) Signed-off-by: Alejandro Colomar --- diff --git a/man/man2/futex.2 b/man/man2/futex.2 index 742e0b51a..4a56c003b 100644 --- a/man/man2/futex.2 +++ b/man/man2/futex.2 @@ -214,7 +214,7 @@ As a convenience, defines a set of constants with the suffix .B _PRIVATE that are equivalents of all of the operations listed below, -.\" except the obsolete FUTEX_FD, for which the "private" flag was +.\" except the obsolete FUTEX_FD(2const), for which the "private" flag was .\" meaningless but with the .B FUTEX_PRIVATE_FLAG @@ -260,43 +260,8 @@ is one of the following: .BR FUTEX_WAIT (2const) .TQ .BR FUTEX_WAKE (2const) -.TP -.BR FUTEX_FD " (from Linux 2.6.0 up to and including Linux 2.6.25)" -.\" Strictly speaking, from Linux 2.5.x to Linux 2.6.25 -This operation creates a file descriptor that is associated with -the futex at -.IR uaddr . -The caller must close the returned file descriptor after use. -When another process or thread performs a -.BR FUTEX_WAKE (2const) -on the futex word, the file descriptor indicates as being readable with -.BR select (2), -.BR poll (2), -and -.BR epoll (7) -.IP -The file descriptor can be used to obtain asynchronous notifications: if -.I val -is nonzero, then, when another process or thread executes a -.BR FUTEX_WAKE (2const), -the caller will receive the signal number that was passed in -.IR val . -.IP -The arguments -.IR timeout , -.IR uaddr2 , -and -.I val3 -are ignored. -.IP -Because it was inherently racy, -.B FUTEX_FD -has been removed -.\" commit 82af7aca56c67061420d618cc5a30f0fd4106b80 -from Linux 2.6.26 onward. -.\" -.\"""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""" -.\" +.TQ +.BR FUTEX_FD (2const) .TP .BR FUTEX_REQUEUE " (since Linux 2.6.0)" This operation performs the same task as @@ -1227,9 +1192,6 @@ is set to indicate the error. The return value on success depends on the operation, as described in the following list: .TP -.B FUTEX_FD -Returns the new file descriptor associated with the futex. -.TP .B FUTEX_REQUEUE Returns the number of waiters that were woken up. .TP @@ -1413,12 +1375,6 @@ equals (i.e., an attempt was made to requeue to the same futex). .TP .B EINVAL -.RB ( FUTEX_FD ) -The signal number supplied in -.I val -is invalid. -.TP -.B EINVAL .RB ( FUTEX_WAKE_OP , .BR FUTEX_WAKE_BITSET , .BR FUTEX_REQUEUE , @@ -1508,10 +1464,6 @@ argument is not 1. .B EINVAL Invalid argument. .TP -.B ENFILE -.RB ( FUTEX_FD ) -The system-wide limit on the total number of open files has been reached. -.TP .B ENOMEM .RB ( FUTEX_LOCK_PI , .BR FUTEX_LOCK_PI2 , diff --git a/man/man2const/FUTEX_FD.2const b/man/man2const/FUTEX_FD.2const new file mode 100644 index 000000000..8072e7bab --- /dev/null +++ b/man/man2const/FUTEX_FD.2const @@ -0,0 +1,77 @@ +.\" Copyright, the authors of the Linux man-pages project +.\" +.\" %%%LICENSE_START(FREELY_REDISTRIBUTABLE) +.\" may be freely modified and distributed +.\" %%%LICENSE_END +.\" +.TH FUTEX_FD 2const (date) "Linux man-pages (unreleased)" +.SH NAME +FUTEX_FD \- create a file descriptor associated with a futex +.SH LIBRARY +Standard C library +.RI ( libc ,\~ \-lc ) +.SH SYNOPSIS +.nf +.BR "#include " " /* Definition of " FUTEX_* " constants */" +.BR "#include " " /* Definition of " SYS_* " constants */" +.B #include +.P +.B [[deprecated]] +.BI "long syscall(SYS_futex, uint32_t *" uaddr ", FUTEX_FD, uint32_t " val ); +.fi +.SH DESCRIPTION +.TP +.BR FUTEX_FD " (from Linux 2.6.0 up to and including Linux 2.6.25)" +.\" Strictly speaking, from Linux 2.5.x to Linux 2.6.25 +This operation creates a file descriptor that is associated with +the futex at +.IR uaddr . +The caller must close the returned file descriptor after use. +When another process or thread performs a +.BR FUTEX_WAKE (2const) +on the futex word, the file descriptor indicates as being readable with +.BR select (2), +.BR poll (2), +and +.BR epoll (7) +.IP +The file descriptor can be used to obtain asynchronous notifications: if +.I val +is nonzero, then, when another process or thread executes a +.BR FUTEX_WAKE (2const), +the caller will receive the signal number that was passed in +.IR val . +.\" +.SH RETURN VALUE +On error, +\-1 is returned, +and +.I errno +is set to indicate the error. +.P +On success, +.B FUTEX_FD +Returns the new file descriptor associated with the futex. +.SH ERRORS +See +.BR futex (2). +.TP +.B EINVAL +The signal number supplied in +.I val +is invalid. +.TP +.B ENFILE +The system-wide limit on the total number of open files has been reached. +.SH STANDARDS +Linux. +.SH HISTORY +From Linux 2.6.0 up to and including Linux 2.6.25. +.P +Because it was inherently racy, +.B FUTEX_FD +has been removed +.\" commit 82af7aca56c67061420d618cc5a30f0fd4106b80 +from Linux 2.6.26 onward. +.SH SEE ALSO +.BR futex (2)