[src/trunk]: src/share/man/man9 Simplify markup for inline code to plain .Li ...

[uwe <uwe%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/559ba7d8e663
branches:  trunk
changeset: 847036:559ba7d8e663
user:      uwe <uwe%NetBSD.org@localhost>
date:      Sun Dec 08 00:00:59 2019 +0000

description:
Simplify markup for inline code to plain .Li in most places.

Use backslashes to protetect embedded spaces in inline code to prevent
filling from stretching them.

Use .Fn and .Fa to refer only to things this manual page documents,
they are not to be used for "a function" or "a function argument" in
general.

In code examples drop the empty line at the beginning of a function
(mandated by the KNF when there are no variables) - it doesn't help
readability here.

diffstat:

 share/man/man9/atomic_loadstore.9 |  80 +++++++++++++++++++++-----------------
 1 files changed, 44 insertions(+), 36 deletions(-)

diffs (230 lines):

diff -r c0396cefe698 -r 559ba7d8e663 share/man/man9/atomic_loadstore.9
--- a/share/man/man9/atomic_loadstore.9 Sat Dec 07 21:14:36 2019 +0000
+++ b/share/man/man9/atomic_loadstore.9 Sun Dec 08 00:00:59 2019 +0000
@@ -1,4 +1,4 @@
-.\"    $NetBSD: atomic_loadstore.9,v 1.4 2019/12/07 12:22:19 wiz Exp $
+.\"    $NetBSD: atomic_loadstore.9,v 1.5 2019/12/08 00:00:59 uwe Exp $
 .\"
 .\" Copyright (c) 2019 The NetBSD Foundation
 .\" All rights reserved.
@@ -77,7 +77,7 @@
 is combining multiple memory operations on a single object into one
 memory operation, such as replacing
 .Bd -literal -compact
-        *p = v;
+       *p = v;
        x = *p;
 .Ed
 by
@@ -86,11 +86,11 @@
        x = v;
 .Ed
 since the compiler can prove that
-.Li * Ns Fa p
+.Li \&*p
 will yield
-.Fa v
+.Li v
 after
-.Li * Ns Fa p Li = Fa v .
+.Li \&*p\ =\ v .
 For
 .Em atomic
 memory operations, the implementation
@@ -142,13 +142,17 @@
 atomic memory operation is issued either all at once or not at all.
 .Pp
 For example, if a 32-bit word
-.Fa w
+.Va w
 is written with
-.Li atomic_store_relaxed ( & Ns Fa w , 0x00010002 ) ,
+.Pp
+.Dl atomic_store_relaxed(&w,\ 0x00010002);
+.Pp
 then an interrupt, other thread, or other CPU reading it with
-.Li atomic_load_relaxed ( & Ns Fa w )
+.Li atomic_load_relaxed(&w)
 will never witness it partially written, whereas
-.Fa w Li = 0x00010002
+.Pp
+.Dl w\ =\ 0x00010002;
+.Pp
 might be compiled into a pair of separate 16-bit store instructions
 instead of one single word-sized store instruction, in which case other
 threads may see the intermediate state with only one of the halves
@@ -178,9 +182,9 @@
 guaranteed.
 Relaxed ordering is the default for ordinary non-atomic memory
 operations like
-.Li * Ns Fa p
+.Li "*p"
 and
-.Li * Ns Fa p Li = Fa v .
+.Li "*p = v" .
 .Pp
 Atomic operations with relaxed ordering are cheap: they are not
 read/modify/write atomic operations, and they do not involve any kind
@@ -403,7 +407,7 @@
 In fact, without
 .Em both
 release and acquire/consume, even the assignment
-.Li m->z = m->x + m->y
+.Li m->z\ =\ m->x\ +\ m->y
 in step\~1 might read values of
 .Li m->x
 and
@@ -527,9 +531,13 @@
 The pointer
 .Fa p
 must be aligned \(em that is, if the object it points to is
-.No 2^ Ns Fa n
+.\"
+2\c
+.ie t \s-2\v'-0.4m'n\v'+0.4m'\s+2
+.el ^n
+.\"
 bytes long, then the low-order
-.Fa n
+.Ar n
 bits of
 .Fa p
 must be zero.
@@ -583,9 +591,9 @@
 These macros are meant to follow
 .Tn C11
 semantics, in terms of
-.Fn atomic_load_explicit
+.Li atomic_load_explicit()
 and
-.Fn atomic_store_explicit
+.Li atomic_store_explicit()
 with the appropriate memory order specifiers, and are meant to make
 future adoption of the
 .Tn C11
@@ -596,28 +604,28 @@
 type qualifier or equivalent for the operands.
 .Sh LINUX ANALOGUES
 The Linux kernel provides two macros
-.Fn READ_ONCE x
+.Li READ_ONCE(x)
 and
-.Fn WRITE_ONCE x v
+.Li WRITE_ONCE(x,\ v)
 which are similar to
-.Li atomic_load_consume ( & Ns Fa x )
+.Li atomic_load_consume(&x)
 and
-.Li atomic_store_relaxed ( & Ns Fa x , Fa v ) ,
+.Li atomic_store_relaxed(&x,\ v) ,
 respectively.
 However, while Linux's
-.Fn READ_ONCE
+.Li READ_ONCE
 and
-.Fn WRITE_ONCE
+.Li WRITE_ONCE
 prevent fusing, they may in some cases be torn \(em and therefore fail
 to guarantee atomicity \(em because:
 .Bl -bullet
 .It
 They do not require the address
-.Li & Ns Fa x
+.Li "&x"
 to be aligned.
 .It
 They do not require
-.Li sizeof ( Fa x )
+.Li sizeof(x)
 to be at most the largest size of available atomic loads and stores on
 the host architecture.
 .El
@@ -633,9 +641,9 @@
 and
 .Fn atomic_load_acquire
 or
-.Fn atomic_load_consume :
+.Fn atomic_load_consume .
 If
-.Fn atomic_r/m/w
+.Li atomic_r/m/w()
 is an atomic read/modify/write operation in
 .Xr atomic_ops 3 ,
 then
@@ -645,7 +653,7 @@
 .Ed
 .Pp
 functions like a release operation on
-.Fa obj ,
+.Va obj ,
 and
 .Bd -literal
        atomic_r/m/w(obj, ...);
@@ -653,7 +661,7 @@
 .Ed
 .Pp
 functions like a acquire operation on
-.Fa obj .
+.Va obj .
 .Pp
 .Sy WARNING :
 The combination of
@@ -700,7 +708,6 @@
        unsigned
        read_event_count(void)
        {
-
                return atomic_load_relaxed(&count);
        }
 .Ed
@@ -713,7 +720,6 @@
        void
        setup_and_notify(void)
        {
-
                setup_data(&d.things);
                atomic_store_release(&ready, 1);
        }
@@ -721,14 +727,15 @@
        void
        try_if_ready(void)
        {
-
                if (atomic_load_acquire(&ready))
                        do_stuff(d.things);
        }
 .Ed
 .Pp
 Publishing a pointer to the current snapshot of data.
-(Caller must arrange that only one call to take_snapshot happens at any
+(Caller must arrange that only one call to
+.Li take_snapshot()
+happens at any
 given time; generally this should be done in coordination with
 .Xr pserialize 9
 or similar to enable resource reclamation.)
@@ -748,7 +755,6 @@
        struct data *
        get_snapshot(void)
        {
-
                return atomic_load_consume(&current_d);
        }
 .Ed
@@ -764,11 +770,13 @@
 .Sh CAVEATS
 C11 formally specifies that all subexpressions, except the left
 operands of the
-.Li "&&" , "||" , "?:" ,
+.Ql && ,
+.Ql || ,
+.Ql ?: ,
 and
-.Li \&,
+.Ql \&,
 operators and the
-.Fn kill_dependency
+.Li kill_dependency()
 macro, carry dependencies for which
 .Dv memory_order_consume
 guarantees ordering, but most or all implementations to date simply