[src/trunk]: src/lib/libc/gen Use an inline function to check for initialisat...

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

details:   https://anonhg.NetBSD.org/src/rev/0156fa6ac68a
branches:  trunk
changeset: 781094:0156fa6ac68a
user:      dsl <dsl%NetBSD.org@localhost>
date:      Sat Aug 18 14:42:46 2012 +0000

description:
Use an inline function to check for initialisation, and an non-inlined
  one to do the actual initialise.
Fixes lib/46751 by removing all the replicated tests in each function.

diffstat:

 lib/libc/gen/arc4random.c |  38 ++++++++++++++++++--------------------
 1 files changed, 18 insertions(+), 20 deletions(-)

diffs (107 lines):

diff -r 5162f6733716 -r 0156fa6ac68a lib/libc/gen/arc4random.c
--- a/lib/libc/gen/arc4random.c Sat Aug 18 14:28:04 2012 +0000
+++ b/lib/libc/gen/arc4random.c Sat Aug 18 14:42:46 2012 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: arc4random.c,v 1.14 2012/07/29 14:44:13 dsl Exp $      */
+/*     $NetBSD: arc4random.c,v 1.15 2012/08/18 14:42:46 dsl Exp $      */
 /*     $OpenBSD: arc4random.c,v 1.6 2001/06/05 05:05:38 pvalchev Exp $ */
 
 /*
@@ -27,7 +27,7 @@
 
 #include <sys/cdefs.h>
 #if defined(LIBC_SCCS) && !defined(lint)
-__RCSID("$NetBSD: arc4random.c,v 1.14 2012/07/29 14:44:13 dsl Exp $");
+__RCSID("$NetBSD: arc4random.c,v 1.15 2012/08/18 14:42:46 dsl Exp $");
 #endif /* LIBC_SCCS and not lint */
 
 #include "namespace.h"
@@ -56,13 +56,12 @@
 /* XXX lint explodes with an internal error if only mtx is initialized! */
 static struct arc4_stream rs = { .i = 0, .mtx = MUTEX_INITIALIZER };
 
-static inline void arc4_init(struct arc4_stream *);
 static inline void arc4_addrandom(struct arc4_stream *, u_char *, int);
 static void arc4_stir(struct arc4_stream *);
 static inline uint8_t arc4_getbyte(struct arc4_stream *);
 static inline uint32_t arc4_getword(struct arc4_stream *);
 
-static inline void
+static __noinline void
 arc4_init(struct arc4_stream *as)
 {
        int n;
@@ -75,6 +74,16 @@
        arc4_stir(as);
 }
 
+static inline int
+arc4_check_init(struct arc4_stream *as)
+{
+       if (__predict_true(rs.initialized))
+               return 0;
+
+       arc4_init(as);
+       return 1;
+}
+
 static inline void
 arc4_addrandom(struct arc4_stream *as, u_char *dat, int datlen)
 {
@@ -154,11 +163,8 @@
 static inline void
 _arc4random_stir_unlocked(void)
 {
-       if (__predict_false(!rs.initialized)) {
-               arc4_init(&rs);                         /* stirs */
-       } else {
+       if (__predict_false(!arc4_check_init(&rs)))     /* init() stirs */
                arc4_stir(&rs);
-       }
 }
 
 void
@@ -178,9 +184,7 @@
 static inline void
 _arc4random_addrandom_unlocked(u_char *dat, int datlen)
 {
-       if (__predict_false(rs.initialized)) {
-               arc4_init(&rs);
-       }
+       arc4_check_init(&rs);
        arc4_addrandom(&rs, dat, datlen);
 }
 
@@ -201,9 +205,7 @@
 static inline uint32_t
 _arc4random_unlocked(void)
 {
-       if (__predict_false(!rs.initialized)) {
-               arc4_init(&rs);
-       }
+       arc4_check_init(&rs);
        return arc4_getword(&rs);
 }
 
@@ -229,9 +231,7 @@
        uint8_t *bp = buf;
        uint8_t *ep = bp + len;
 
-       if (__predict_false(!rs.initialized)) {
-               arc4_init(&rs);
-       }
+       arc4_check_init(&rs);
 
        bp[0] = arc4_getbyte(&rs) % 3;
        while (bp[0]--)
@@ -297,9 +297,7 @@
         * number inside the range we need, so it should rarely need
         * to re-roll (at all).
         */
-       if (__predict_false(!rs.initialized)) {
-               arc4_init(&rs);
-       }
+       arc4_check_init(&rs);
        if (arc4_getbyte(&rs) & 1)
                (void)arc4_getbyte(&rs);
        do