Switch over to using our own qsort() all the time, as has been proposed
authorTom Lane <tgl@sss.pgh.pa.us>
Tue, 3 Oct 2006 22:18:23 +0000 (22:18 +0000)
committerTom Lane <tgl@sss.pgh.pa.us>
Tue, 3 Oct 2006 22:18:23 +0000 (22:18 +0000)
repeatedly.  Now that we don't have to worry about memory leaks from
glibc's qsort, we can safely put CHECK_FOR_INTERRUPTS into the tuplesort
comparators, as was requested a couple months ago.  Also, get rid of
non-reentrancy and an extra level of function call in tuplesort.c by
providing a variant qsort_arg() API that passes an extra void * argument
through to the comparison routine.  (We might want to use that in other
places too, I didn't look yet.)

configure
configure.in
src/Makefile.global.in
src/backend/utils/sort/tuplesort.c
src/include/port.h
src/port/qsort.c
src/port/qsort_arg.c [new file with mode: 0644]

index fc30557989ce236a249bb7f481fb14a0e574b6de..9f2ba2ae78dc0ec5baca0ab5f11815e1eb3fec6e 100755 (executable)
--- a/configure
+++ b/configure
@@ -14951,21 +14951,6 @@ case $host_os in bsdi*|netbsd*)
 ac_cv_func_fseeko=yes
 esac
 
-# Solaris has a very slow qsort in certain cases, so we replace it:
-#   http://forum.sun.com/thread.jspa?forumID=4&threadID=7231
-# Supposedly it is fixed in Solaris, but not sure which version, and
-# no confirmed testing.  2005-12-16
-if test "$PORTNAME" = "solaris"; then
-case $LIBOBJS in
-    "qsort.$ac_objext"   | \
-  *" qsort.$ac_objext"   | \
-    "qsort.$ac_objext "* | \
-  *" qsort.$ac_objext "* ) ;;
-  *) LIBOBJS="$LIBOBJS qsort.$ac_objext" ;;
-esac
-
-fi
-
 # Win32 support
 if test "$PORTNAME" = "win32"; then
 case $LIBOBJS in
index d3764a4542f65f5c7dff863f83b2804b264ba3b1..42b2579fbb07c6a780cdf17b3eab8d4de0e07bdc 100644 (file)
@@ -1,5 +1,5 @@
 dnl Process this file with autoconf to produce a configure script.
-dnl $PostgreSQL: pgsql/configure.in,v 1.478 2006/10/02 00:06:18 tgl Exp $
+dnl $PostgreSQL: pgsql/configure.in,v 1.479 2006/10/03 22:18:22 tgl Exp $
 dnl
 dnl Developers, please strive to achieve this order:
 dnl
@@ -986,14 +986,6 @@ case $host_os in bsdi*|netbsd*)
 ac_cv_func_fseeko=yes
 esac
 
-# Solaris has a very slow qsort in certain cases, so we replace it:
-#   http://forum.sun.com/thread.jspa?forumID=4&threadID=7231
-# Supposedly it is fixed in Solaris, but not sure which version, and
-# no confirmed testing.  2005-12-16
-if test "$PORTNAME" = "solaris"; then
-AC_LIBOBJ(qsort)
-fi
-
 # Win32 support
 if test "$PORTNAME" = "win32"; then
 AC_LIBOBJ(gettimeofday)
index 60493a8e4bfe8413762e79f9703da709a424683a..4e55fe9bfdcea07103eed3f76f75b59acf7df574 100644 (file)
@@ -1,5 +1,5 @@
 # -*-makefile-*-
-# $PostgreSQL: pgsql/src/Makefile.global.in,v 1.230 2006/09/19 15:36:07 tgl Exp $
+# $PostgreSQL: pgsql/src/Makefile.global.in,v 1.231 2006/10/03 22:18:22 tgl Exp $
 
 #------------------------------------------------------------------------------
 # All PostgreSQL makefiles include this file and use the variables it sets,
@@ -413,7 +413,7 @@ endif
 #
 # substitute implementations of C library routines (see src/port/)
 
-LIBOBJS = @LIBOBJS@ copydir.o dirmod.o exec.o noblock.o path.o pipe.o pgsleep.o pgstrcasecmp.o sprompt.o thread.o
+LIBOBJS = @LIBOBJS@ copydir.o dirmod.o exec.o noblock.o path.o pipe.o pgsleep.o pgstrcasecmp.o qsort.o qsort_arg.o sprompt.o thread.o
 
 LIBS := -lpgport $(LIBS)
 # add location of libpgport.a to LDFLAGS
index 7d503f244fb07b597087d0338d637628ebd15373..08e63e0756dbc1cb8837e89818f370c8ae4c428b 100644 (file)
@@ -91,7 +91,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *       $PostgreSQL: pgsql/src/backend/utils/sort/tuplesort.c,v 1.68 2006/07/14 14:52:25 momjian Exp $
+ *       $PostgreSQL: pgsql/src/backend/utils/sort/tuplesort.c,v 1.69 2006/10/03 22:18:23 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -201,11 +201,11 @@ struct Tuplesortstate
         * They are set up by the tuplesort_begin_xxx routines.
         *
         * Function to compare two tuples; result is per qsort() convention, ie:
-        *
-        * <0, 0, >0 according as a<b, a=b, a>b.
+        * <0, 0, >0 according as a<b, a=b, a>b.  The API must match
+        * qsort_arg_comparator.
         */
-       int                     (*comparetup) (Tuplesortstate *state,
-                                                          const SortTuple *a, const SortTuple *b);
+       int                     (*comparetup) (const SortTuple *a, const SortTuple *b,
+                                                          Tuplesortstate *state);
 
        /*
         * Function to copy a supplied input tuple into palloc'd space and set up
@@ -345,7 +345,7 @@ struct Tuplesortstate
 #endif
 };
 
-#define COMPARETUP(state,a,b)  ((*(state)->comparetup) (state, a, b))
+#define COMPARETUP(state,a,b)  ((*(state)->comparetup) (a, b, state))
 #define COPYTUP(state,stup,tup)        ((*(state)->copytup) (state, stup, tup))
 #define WRITETUP(state,tape,stup)      ((*(state)->writetup) (state, tape, stup))
 #define READTUP(state,stup,tape,len) ((*(state)->readtup) (state, stup, tape, len))
@@ -410,37 +410,28 @@ static void tuplesort_heap_insert(Tuplesortstate *state, SortTuple *tuple,
 static void tuplesort_heap_siftup(Tuplesortstate *state, bool checkIndex);
 static unsigned int getlen(Tuplesortstate *state, int tapenum, bool eofOK);
 static void markrunend(Tuplesortstate *state, int tapenum);
-static int     qsort_comparetup(const void *a, const void *b);
-static int comparetup_heap(Tuplesortstate *state,
-                               const SortTuple *a, const SortTuple *b);
+static int comparetup_heap(const SortTuple *a, const SortTuple *b,
+                                                  Tuplesortstate *state);
 static void copytup_heap(Tuplesortstate *state, SortTuple *stup, void *tup);
 static void writetup_heap(Tuplesortstate *state, int tapenum,
                                                  SortTuple *stup);
 static void readtup_heap(Tuplesortstate *state, SortTuple *stup,
                                                 int tapenum, unsigned int len);
-static int comparetup_index(Tuplesortstate *state,
-                                const SortTuple *a, const SortTuple *b);
+static int comparetup_index(const SortTuple *a, const SortTuple *b,
+                                                       Tuplesortstate *state);
 static void copytup_index(Tuplesortstate *state, SortTuple *stup, void *tup);
 static void writetup_index(Tuplesortstate *state, int tapenum,
                                                   SortTuple *stup);
 static void readtup_index(Tuplesortstate *state, SortTuple *stup,
                                                  int tapenum, unsigned int len);
-static int comparetup_datum(Tuplesortstate *state,
-                                const SortTuple *a, const SortTuple *b);
+static int comparetup_datum(const SortTuple *a, const SortTuple *b,
+                                                       Tuplesortstate *state);
 static void copytup_datum(Tuplesortstate *state, SortTuple *stup, void *tup);
 static void writetup_datum(Tuplesortstate *state, int tapenum,
                                                   SortTuple *stup);
 static void readtup_datum(Tuplesortstate *state, SortTuple *stup,
                                                  int tapenum, unsigned int len);
 
-/*
- * Since qsort(3) will not pass any context info to qsort_comparetup(),
- * we have to use this ugly static variable.  It is set to point to the
- * active Tuplesortstate object just before calling qsort.     It should
- * not be used directly by anything except qsort_comparetup().
- */
-static Tuplesortstate *qsort_tuplesortstate;
-
 
 /*
  *             tuplesort_begin_xxx
@@ -930,11 +921,11 @@ tuplesort_performsort(Tuplesortstate *state)
                         * amount of memory.  Just qsort 'em and we're done.
                         */
                        if (state->memtupcount > 1)
-                       {
-                               qsort_tuplesortstate = state;
-                               qsort((void *) state->memtuples, state->memtupcount,
-                                         sizeof(SortTuple), qsort_comparetup);
-                       }
+                               qsort_arg((void *) state->memtuples,
+                                                 state->memtupcount,
+                                                 sizeof(SortTuple),
+                                                 (qsort_arg_comparator) state->comparetup,
+                                                 (void *) state);
                        state->current = 0;
                        state->eof_reached = false;
                        state->markpos_offset = 0;
@@ -1587,7 +1578,6 @@ mergeonerun(Tuplesortstate *state)
         */
        while (state->memtupcount > 0)
        {
-               CHECK_FOR_INTERRUPTS();
                /* write the tuple to destTape */
                priorAvail = state->availMem;
                srcTape = state->memtuples[0].tupindex;
@@ -2091,20 +2081,6 @@ markrunend(Tuplesortstate *state, int tapenum)
 }
 
 
-/*
- * qsort interface
- */
-
-static int
-qsort_comparetup(const void *a, const void *b)
-{
-       /* The passed pointers are pointers to SortTuple ... */
-       return COMPARETUP(qsort_tuplesortstate,
-                                         (const SortTuple *) a,
-                                         (const SortTuple *) b);
-}
-
-
 /*
  * This routine selects an appropriate sorting function to implement
  * a sort operator as efficiently as possible. The straightforward
@@ -2319,7 +2295,7 @@ ApplySortFunction(FmgrInfo *sortFunction, SortFunctionKind kind,
  */
 
 static int
-comparetup_heap(Tuplesortstate *state, const SortTuple *a, const SortTuple *b)
+comparetup_heap(const SortTuple *a, const SortTuple *b, Tuplesortstate *state)
 {
        ScanKey         scanKey = state->scanKeys;
        HeapTupleData ltup;
@@ -2328,6 +2304,9 @@ comparetup_heap(Tuplesortstate *state, const SortTuple *a, const SortTuple *b)
        int                     nkey;
        int32           compare;
 
+       /* Allow interrupting long sorts */
+       CHECK_FOR_INTERRUPTS();
+
        /* Compare the leading sort key */
        compare = inlineApplySortFunction(&scanKey->sk_func,
                                                                          state->sortFnKinds[0],
@@ -2449,7 +2428,7 @@ readtup_heap(Tuplesortstate *state, SortTuple *stup,
  */
 
 static int
-comparetup_index(Tuplesortstate *state, const SortTuple *a, const SortTuple *b)
+comparetup_index(const SortTuple *a, const SortTuple *b, Tuplesortstate *state)
 {
        /*
         * This is similar to _bt_tuplecompare(), but we have already done the
@@ -2466,6 +2445,9 @@ comparetup_index(Tuplesortstate *state, const SortTuple *a, const SortTuple *b)
        int                     nkey;
        int32           compare;
 
+       /* Allow interrupting long sorts */
+       CHECK_FOR_INTERRUPTS();
+
        /* Compare the leading sort key */
        compare = inlineApplySortFunction(&scanKey->sk_func,
                                                                          SORTFUNC_CMP,
@@ -2622,8 +2604,11 @@ readtup_index(Tuplesortstate *state, SortTuple *stup,
  */
 
 static int
-comparetup_datum(Tuplesortstate *state, const SortTuple *a, const SortTuple *b)
+comparetup_datum(const SortTuple *a, const SortTuple *b, Tuplesortstate *state)
 {
+       /* Allow interrupting long sorts */
+       CHECK_FOR_INTERRUPTS();
+
        return inlineApplySortFunction(&state->sortOpFn, state->sortFnKind,
                                                                   a->datum1, a->isnull1,
                                                                   b->datum1, b->isnull1);
index eb8b0318159e557067db6cef7dc028ca4a40e252..cf3694f4f526f7dd25011e8d565067a11e9c104f 100644 (file)
@@ -6,10 +6,12 @@
  * Portions Copyright (c) 1996-2006, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/port.h,v 1.102 2006/10/02 00:06:18 tgl Exp $
+ * $PostgreSQL: pgsql/src/include/port.h,v 1.103 2006/10/03 22:18:23 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
+#ifndef PG_PORT_H
+#define PG_PORT_H
 
 #include <ctype.h>
 #include <netdb.h>
@@ -361,3 +363,10 @@ extern int pqGethostbyname(const char *name,
                                char *buffer, size_t buflen,
                                struct hostent ** result,
                                int *herrno);
+
+typedef int (*qsort_arg_comparator) (const void *a, const void *b, void *arg);
+
+extern void qsort_arg(void *base, size_t nel, size_t elsize,
+                                         qsort_arg_comparator cmp, void *arg);
+
+#endif /* PG_PORT_H */
index a7aa8cea2a9fa38c221e79e57f6a421f4b06ebaa..3f3e7787e9fd2566ef4487af7bac8e939dc34dee 100644 (file)
@@ -1,11 +1,15 @@
 /*
+ *     qsort.c: standard quicksort algorithm
+ *
  *     Modifications from vanilla NetBSD source:
  *       Add do ... while() macro fix
  *       Remove __inline, _DIAGASSERTs, __P
  *       Remove ill-considered "swap_cnt" switch to insertion sort,
  *       in favor of a simple check for presorted input.
  *
- *     $PostgreSQL: pgsql/src/port/qsort.c,v 1.9 2006/03/21 19:49:15 tgl Exp $
+ *     CAUTION: if you change this file, see also qsort_arg.c
+ *
+ *     $PostgreSQL: pgsql/src/port/qsort.c,v 1.10 2006/10/03 22:18:23 tgl Exp $
  */
 
 /*     $NetBSD: qsort.c,v 1.13 2003/08/07 16:43:42 agc Exp $   */
diff --git a/src/port/qsort_arg.c b/src/port/qsort_arg.c
new file mode 100644 (file)
index 0000000..ac7b149
--- /dev/null
@@ -0,0 +1,201 @@
+/*
+ *     qsort_arg.c: qsort with a passthrough "void *" argument
+ *
+ *     Modifications from vanilla NetBSD source:
+ *       Add do ... while() macro fix
+ *       Remove __inline, _DIAGASSERTs, __P
+ *       Remove ill-considered "swap_cnt" switch to insertion sort,
+ *       in favor of a simple check for presorted input.
+ *
+ *     CAUTION: if you change this file, see also qsort.c
+ *
+ *     $PostgreSQL: pgsql/src/port/qsort_arg.c,v 1.1 2006/10/03 22:18:23 tgl Exp $
+ */
+
+/*     $NetBSD: qsort.c,v 1.13 2003/08/07 16:43:42 agc Exp $   */
+
+/*-
+ * Copyright (c) 1992, 1993
+ *     The Regents of the University of California.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *       notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *       notice, this list of conditions and the following disclaimer in the
+ *       documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the University nor the names of its contributors
+ *       may be used to endorse or promote products derived from this software
+ *       without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.     IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include "c.h"
+
+
+static char *med3(char *a, char *b, char *c,
+                                 qsort_arg_comparator cmp, void *arg);
+static void swapfunc(char *, char *, size_t, int);
+
+#define min(a, b)      ((a) < (b) ? (a) : (b))
+
+/*
+ * Qsort routine based on J. L. Bentley and M. D. McIlroy,
+ * "Engineering a sort function",
+ * Software--Practice and Experience 23 (1993) 1249-1265.
+ * We have modified their original by adding a check for already-sorted input,
+ * which seems to be a win per discussions on pgsql-hackers around 2006-03-21.
+ */
+#define swapcode(TYPE, parmi, parmj, n) \
+do {           \
+       size_t i = (n) / sizeof (TYPE);                 \
+       TYPE *pi = (TYPE *)(void *)(parmi);                     \
+       TYPE *pj = (TYPE *)(void *)(parmj);                     \
+       do {                                            \
+               TYPE    t = *pi;                        \
+               *pi++ = *pj;                            \
+               *pj++ = t;                              \
+               } while (--i > 0);                              \
+} while (0)
+
+#define SWAPINIT(a, es) swaptype = ((char *)(a) - (char *)0) % sizeof(long) || \
+       (es) % sizeof(long) ? 2 : (es) == sizeof(long)? 0 : 1;
+
+static void
+swapfunc(a, b, n, swaptype)
+char      *a,
+                  *b;
+size_t         n;
+int                    swaptype;
+{
+       if (swaptype <= 1)
+               swapcode(long, a, b, n);
+       else
+               swapcode(char, a, b, n);
+}
+
+#define swap(a, b)                                             \
+       if (swaptype == 0) {                                    \
+               long t = *(long *)(void *)(a);                  \
+               *(long *)(void *)(a) = *(long *)(void *)(b);    \
+               *(long *)(void *)(b) = t;                       \
+       } else                                                  \
+               swapfunc(a, b, es, swaptype)
+
+#define vecswap(a, b, n) if ((n) > 0) swapfunc((a), (b), (size_t)(n), swaptype)
+
+static char *
+med3(char *a, char *b, char *c, qsort_arg_comparator cmp, void *arg)
+{
+       return cmp(a, b, arg) < 0 ?
+               (cmp(b, c, arg) < 0 ? b : (cmp(a, c, arg) < 0 ? c : a))
+               : (cmp(b, c, arg) > 0 ? b : (cmp(a, c, arg) < 0 ? a : c));
+}
+
+void
+qsort_arg(void *a, size_t n, size_t es, qsort_arg_comparator cmp, void *arg)
+{
+       char       *pa,
+                          *pb,
+                          *pc,
+                          *pd,
+                          *pl,
+                          *pm,
+                          *pn;
+       int                     d,
+                               r,
+                               swaptype,
+                               presorted;
+
+loop:SWAPINIT(a, es);
+       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, arg) > 0;
+                                pl -= es)
+                               swap(pl, pl - es);
+               return;
+       }
+       presorted = 1;
+       for (pm = (char *) a + es; pm < (char *) a + n * es; pm += es)
+       {
+               if (cmp(pm - es, pm, arg) > 0)
+               {
+                       presorted = 0;
+                       break;
+               }
+       }
+       if (presorted)
+               return;
+       pm = (char *) a + (n / 2) * es;
+       if (n > 7)
+       {
+               pl = (char *) a;
+               pn = (char *) a + (n - 1) * es;
+               if (n > 40)
+               {
+                       d = (n / 8) * es;
+                       pl = med3(pl, pl + d, pl + 2 * d, cmp, arg);
+                       pm = med3(pm - d, pm, pm + d, cmp, arg);
+                       pn = med3(pn - 2 * d, pn - d, pn, cmp, arg);
+               }
+               pm = med3(pl, pm, pn, cmp, arg);
+       }
+       swap(a, pm);
+       pa = pb = (char *) a + es;
+       pc = pd = (char *) a + (n - 1) * es;
+       for (;;)
+       {
+               while (pb <= pc && (r = cmp(pb, a, arg)) <= 0)
+               {
+                       if (r == 0)
+                       {
+                               swap(pa, pb);
+                               pa += es;
+                       }
+                       pb += es;
+               }
+               while (pb <= pc && (r = cmp(pc, a, arg)) >= 0)
+               {
+                       if (r == 0)
+                       {
+                               swap(pc, pd);
+                               pd -= es;
+                       }
+                       pc -= es;
+               }
+               if (pb > pc)
+                       break;
+               swap(pb, pc);
+               pb += es;
+               pc -= es;
+       }
+       pn = (char *) a + n * es;
+       r = min(pa - (char *) a, pb - pa);
+       vecswap(a, pb - r, r);
+       r = min(pd - pc, pn - pd - es);
+       vecswap(pb, pn - r, r);
+       if ((r = pb - pa) > es)
+               qsort_arg(a, r / es, es, cmp, arg);
+       if ((r = pd - pc) > es)
+       {
+               /* Iterate rather than recurse to save stack space */
+               a = pn - r;
+               n = r / es;
+               goto loop;
+       }
+/*             qsort_arg(pn - r, r / es, es, cmp, arg);*/
+}