[PATCH v3 2/3] Consolidate Linux sigprocmask implementation (BZ #22391)

[Rical Jasan]

Just one final nit.

On 11/15/2017 09:54 AM, Adhemerval Zanella wrote:
> diff --git a/manual/signal.texi b/manual/signal.texi
> index 9577ff0..4f0ef59 100644
> --- a/manual/signal.texi
> +++ b/manual/signal.texi
> @@ -235,6 +235,7 @@ defined.  Since the signal numbers are allocated consecutively,
>  * Job Control Signals::         Signals used to support job control.
>  * Operation Error Signals::     Used to report operational system errors.
>  * Miscellaneous Signals::       Miscellaneous Signals.
> +* Internally-Used Signals::     Signals used internally by the C library.
>  * Signal Messages::             Printing a message describing a signal.
>  @end menu
>  
> @@ -794,6 +795,26 @@ in @ref{Signaling Another Process}.
>  The default action is to terminate the process.
>  @end deftypevr
>  
> +@deftypevr Macro int SIGRTMIN
> +@deftypevrx Macro int SIGRTMAX
> +@standards{POSIX.1, signal.h}
> +@cindex real-time signals

This @cindex should go above the @deftypevr to ensure the reader lands
above the heading.  Much of the time the difference probably won't be
noticeable, but it's annoying when you run into that off-chance of it
being on some weird boundary.  The Texinfo manual does mention keeping
index entries above "visible material" [1].

> +The range of signal numbers @code{SIGRTMIN}, @code{SIGRTMIN+1},
> +@dots{}, @code{SIGRTMAX} is also set aside for you to use any way you
> +want.  In addition, these signals (and no others) are guaranteed to
> +support @dfn{real-time} signal semantics, which unfortunately this
> +manual does not yet document.
> +
> +Unlike all of the other signal number macros, @code{SIGRTMIN} and
> +@code{SIGRTMAX} are not compile-time constants, because some operating
> +systems make the number of real-time signals tunable on a
> +per-installation or even per-process basis.  However, POSIX guarantees
> +that there will be at least 8 signal numbers in this range.
> +
> +The default action for all signals in this range is to terminate the
> +process.
> +@end deftypevr
> +
>  @deftypevr Macro int SIGWINCH
>  @standards{BSD, signal.h}
>  Window size change.  This is generated on some systems (including GNU)
> @@ -817,6 +838,22 @@ to print some status information about the system and what the process
>  is doing.  Otherwise the default is to do nothing.
>  @end deftypevr
>  
> +@node Internally-Used Signals
> +@subsection Internally-Used Signals
> +@cindex internally used signals

This @cindex, however, must be underneath, as it won't be associated
with the correct section otherwise.

> +
> +On some operating systems, @theglibc{} needs to use a few signals from
> +the ``true'' real-time range internally, to implement thread
> +cancellation, cross-thread effective ID synchronization, POSIX timer
> +management, etc.  @Theglibc{} adjusts @code{SIGRTMIN} and
> +@code{SIGRTMAX} to exclude these signals, and it also takes steps to
> +prevent application code from altering their state: @code{sigprocmask}
> +cannot block them and @code{sigaction} cannot redefine their handlers,
> +for instance.  Therefore, most programs do not need to know or care
> +about these signals.  We mainly document their existence for the sake
> +of anyone who has ever wondered why there is a gap between the
> +highest-numbered ``normal'' signal and @code{SIGRTMIN} on Linux.
> +
>  @node Signal Messages
>  @subsection Signal Messages
>  @cindex signal messages


Rical

[1]
https://www.gnu.org/software/texinfo/manual/texinfo/html_node/Indexing-Commands.html#Indexing-Commands