Copy qsort_r(3) from libc to libkern.

Reviewed by:	phk
Approved by:	julian (mentor)

2 files changed, 49 insertions, 24 deletions

diff --git a/sys/libkern/qsort.c b/sys/libkern/qsort.c
index fbd4aa6..bb0baee 100644
--- a/sys/libkern/qsort.c
+++ b/sys/libkern/qsort.c
@@ -30,10 +30,15 @@
 #include <sys/cdefs.h>
 __FBSDID("$FreeBSD$");
 
+#include <sys/param.h>
 #include <sys/libkern.h>
 
-typedef int		 cmp_t(const void *, const void *);
-static __inline char	*med3(char *, char *, char *, cmp_t *);
+#ifdef	I_AM_QSORT_R
+typedef int		cmp_t(void *, const void *, const void *);
+#else
+typedef int		cmp_t(const void *, const void *);
+#endif
+static __inline char	*med3(char *, char *, char *, cmp_t *, void *);
 static __inline void	 swapfunc(char *, char *, int, int);
 
 #define min(a, b)	(a) < (b) ? (a) : (b)
@@ -56,9 +61,7 @@ static __inline void	 swapfunc(char *, char *, int, int);
 	es % sizeof(long) ? 2 : es == sizeof(long)? 0 : 1;
 
 static __inline void
-swapfunc(a, b, n, swaptype)
-	char *a, *b;
-	int n, swaptype;
+swapfunc(char *a, char *b, int n, int swaptype)
 {
 	if(swaptype <= 1)
 		swapcode(long, a, b, n)
@@ -76,21 +79,32 @@ swapfunc(a, b, n, swaptype)
 
 #define vecswap(a, b, n) 	if ((n) > 0) swapfunc(a, b, n, swaptype)
 
+#ifdef I_AM_QSORT_R
+#define	CMP(t, x, y) (cmp((t), (x), (y)))
+#else
+#define	CMP(t, x, y) (cmp((x), (y)))
+#endif
+
 static __inline char *
-med3(a, b, c, cmp)
-	char *a, *b, *c;
-	cmp_t *cmp;
+med3(char *a, char *b, char *c, cmp_t *cmp, void *thunk
+#ifndef	I_AM_QSORT_R
+__unused
+#endif
+)
 {
-	return cmp(a, b) < 0 ?
-	       (cmp(b, c) < 0 ? b : (cmp(a, c) < 0 ? c : a ))
-              :(cmp(b, c) > 0 ? b : (cmp(a, c) < 0 ? a : c ));
+	return CMP(thunk, a, b) < 0 ?
+	       (CMP(thunk, b, c) < 0 ? b : (CMP(thunk, a, c) < 0 ? c : a ))
+              :(CMP(thunk, b, c) > 0 ? b : (CMP(thunk, a, c) < 0 ? a : c ));
 }
 
+#ifdef I_AM_QSORT_R
+void
+qsort_r(void *a, size_t n, size_t es, void *thunk, cmp_t *cmp)
+#else
+#define	thunk NULL
 void
-qsort(a, n, es, cmp)
-	void *a;
-	size_t n, es;
-	cmp_t *cmp;
+qsort(void *a, size_t n, size_t es, cmp_t *cmp)
+#endif
 {
 	char *pa, *pb, *pc, *pd, *pl, *pm, *pn;
 	int d, r, swaptype, swap_cnt;
@@ -99,7 +113,7 @@ loop:	SWAPINIT(a, es);
 	swap_cnt = 0;
 	if (n < 7) {
 		for (pm = (char *)a + es; pm < (char *)a + n * es; pm += es)
-			for (pl = pm; pl > (char *)a && cmp(pl - es, pl) > 0;
+			for (pl = pm; pl > (char *)a && CMP(thunk, pl - es, pl) > 0;
 			     pl -= es)
 				swap(pl, pl - es);
 		return;
@@ -110,18 +124,18 @@ loop:	SWAPINIT(a, es);
 		pn = (char *)a + (n - 1) * es;
 		if (n > 40) {
 			d = (n / 8) * es;
-			pl = med3(pl, pl + d, pl + 2 * d, cmp);
-			pm = med3(pm - d, pm, pm + d, cmp);
-			pn = med3(pn - 2 * d, pn - d, pn, cmp);
+			pl = med3(pl, pl + d, pl + 2 * d, cmp, thunk);
+			pm = med3(pm - d, pm, pm + d, cmp, thunk);
+			pn = med3(pn - 2 * d, pn - d, pn, cmp, thunk);
 		}
-		pm = med3(pl, pm, pn, cmp);
+		pm = med3(pl, pm, pn, cmp, thunk);
 	}
 	swap(a, pm);
 	pa = pb = (char *)a + es;
 
 	pc = pd = (char *)a + (n - 1) * es;
 	for (;;) {
-		while (pb <= pc && (r = cmp(pb, a)) <= 0) {
+		while (pb <= pc && (r = CMP(thunk, pb, a)) <= 0) {
 			if (r == 0) {
 				swap_cnt = 1;
 				swap(pa, pb);
@@ -129,7 +143,7 @@ loop:	SWAPINIT(a, es);
 			}
 			pb += es;
 		}
-		while (pb <= pc && (r = cmp(pc, a)) >= 0) {
+		while (pb <= pc && (r = CMP(thunk, pc, a)) >= 0) {
 			if (r == 0) {
 				swap_cnt = 1;
 				swap(pc, pd);
@@ -146,7 +160,7 @@ loop:	SWAPINIT(a, es);
 	}
 	if (swap_cnt == 0) {  /* Switch to insertion sort */
 		for (pm = (char *)a + es; pm < (char *)a + n * es; pm += es)
-			for (pl = pm; pl > (char *)a && cmp(pl - es, pl) > 0;
+			for (pl = pm; pl > (char *)a && CMP(thunk, pl - es, pl) > 0;
 			     pl -= es)
 				swap(pl, pl - es);
 		return;
@@ -158,12 +172,15 @@ loop:	SWAPINIT(a, es);
 	r = min(pd - pc, pn - pd - es);
 	vecswap(pb, pn - r, r);
 	if ((r = pb - pa) > es)
+#ifdef	I_AM_QSORT_R
+		qsort_r(a, r / es, es, thunk, cmp);
+#else
 		qsort(a, r / es, es, cmp);
+#endif
 	if ((r = pd - pc) > es) {
 		/* Iterate rather than recurse to save stack space */
 		a = pn - r;
 		n = r / es;
 		goto loop;
 	}
-/*		qsort(pn - r, r / es, es, cmp);*/
 }
diff --git a/sys/libkern/qsort_r.c b/sys/libkern/qsort_r.c
new file mode 100644
index 0000000..386d1cf
--- /dev/null
+++ b/sys/libkern/qsort_r.c
@@ -0,0 +1,8 @@
+/*
+ * This file is in the public domain.  Originally written by Garrett
+ * A. Wollman.
+ *
+ * $FreeBSD$
+ */
+#define I_AM_QSORT_R
+#include "libkern/qsort.c"