[MTASCsft PATCH 09/??] MT-, AS- and AC-Safety docs: manual/errno.texi

[Carlos O'Donell]

On 02/01/2014 12:52 AM, Alexandre Oliva wrote:
> On Feb  1, 2014, "Carlos O'Donell" <carlos@redhat.com> wrote:
> 
>> OK to checkin with typos fixed and some note about why identifiers
>> are important is added.
> 
> Thanks, fixed and added.  Here's the patch I checked in along with the 3
> patches that depended on this one:
 
Looks great. Thanks!
 
> MT-, AS- and AC-safety docs: identifiers and conditionals
> 
> From: Alexandre Oliva <aoliva@redhat.com>
> 
> for ChangeLog
> 
> 	* manual/intro.texi: Document safety identifiers and
> 	conditionals.
> ---
>  manual/intro.texi |   48 +++++++++++++++++++++++++++++++++++++++++++++---
>  1 file changed, 45 insertions(+), 3 deletions(-)
> 
> diff --git a/manual/intro.texi b/manual/intro.texi
> index fb501a6..0f57859 100644
> --- a/manual/intro.texi
> +++ b/manual/intro.texi
> @@ -669,7 +669,10 @@ concurrent and reentrant interactions with it, by not using it in signal
>  handlers or blocking signals that might use it, and holding a lock while
>  calling these functions and interacting with the terminal.  This lock
>  should also be used for mutual exclusion with functions marked with
> -@code{@mtasurace{:tcattr}}.
> +@code{@mtasurace{:tcattr(fd)}}, where @var{fd} is a file descriptor for
> +the controlling terminal.  The caller may use a single mutex for
> +simplicity, or use one mutex per terminal, even if referenced by
> +different file descriptors.
>  
>  Functions marked with @code{term} as an AC-Safety issue are supposed to
>  restore terminal settings to their original state, after temporarily
> @@ -698,7 +701,6 @@ taken into account in certain classes of programs:
>  
>  @itemize @bullet
>  
> -@c revisit: uses are mt-safe, distinguish from const:locale
>  @item @code{locale}
>  @cindex locale
>  
> @@ -729,7 +731,6 @@ constant in these contexts, which makes the former safe.
>  @c because of the unexpected locale changes.
>  
>  
> -@c revisit: this was incorrectly used as an mt-unsafe marker.
>  @item @code{env}
>  @cindex env
>  
> @@ -855,6 +856,47 @@ properties we documented are identical to those mandated by POSIX for
>  the corresponding functions.
>  
>  
> +@item @code{:identifier}
> +@cindex :identifier
> +
> +Annotations may sometimes be followed by identifiers, intended to group
> +several functions that e.g. access the data structures in an unsafe way,
> +as in @code{race} and @code{const}, or to provide more specific
> +information, such as naming a signal in a function marked with
> +@code{sig}.  It is envisioned that it may be applied to @code{lock} and
> +@code{corrupt} as well in the future.
> +
> +In most cases, the identifier will name a set of functions, but it may
> +name global objects or function arguments, or identifiable properties or
> +logical components associated with them, with a notation such as
> +e.g. @code{:buf(arg)} to denote a buffer associated with the argument
> +@var{arg}, or @code{:tcattr(fd)} to denote the terminal attributes of a
> +file descriptor @var{fd}.
> +
> +The most common use for identifiers is to provide logical groups of
> +functions and arguments that need to be protected by the same
> +synchronization primitive in order to ensure safe operation in a given
> +context.
> +
> +
> +@item @code{/condition}
> +@cindex /condition
> +
> +Some safety annotations may be conditional, in that they only apply if a
> +boolean expression involving arguments, global variables or even the
> +underlying kernel evaluates evaluates to true.  Such conditions as
> +@code{/hurd} or @code{/!linux!bsd} indicate the preceding marker only
> +applies when the underlying kernel is the HURD, or when it is neither
> +Linux nor a BSD kernel, respectively.  @code{/!ps} and
> +@code{/one_per_line} indicate the preceding marker only applies when
> +argument @var{ps} is NULL, or global variable @var{one_per_line} is
> +nonzero.
> +
> +When all marks that render a function unsafe are adorned with such
> +conditions, and none of the named conditions hold, then the function can
> +be regarded as safe.
> +
> +
>  @end itemize
>  
>  
> 
>