Made qsort() thread-safe.

svn path=/trunk/; revision=2294
This commit is contained in:
Eric Kohl 2001-10-11 23:37:47 +00:00
parent 061fadc77a
commit 0a88910738
2 changed files with 53 additions and 48 deletions

View file

@ -7,16 +7,21 @@
typedef struct _ThreadData
{
int terrno; /* *nix error code */
unsigned long tdoserrno; /* Win32 error code (for I/O only) */
unsigned long long tnext; /* used by rand/srand */
int terrno; /* *nix error code */
unsigned long tdoserrno; /* Win32 error code (for I/O only) */
unsigned long long tnext; /* used by rand/srand */
char *lasttoken; /* used by strtok */
wchar_t *wlasttoken; /* used by wcstok */
char *lasttoken; /* used by strtok */
wchar_t *wlasttoken; /* used by wcstok */
int fpecode; /* fp exception code */
int fpecode; /* fp exception code */
/* qsort variables */
int (*qcmp)(const void *, const void *); /* the comparison routine */
int qsz; /* size of each record */
int thresh; /* THRESHold in chars */
int mthresh; /* MTHRESHold in chars */
} THREADDATA, *PTHREADDATA;

View file

@ -1,5 +1,6 @@
/* Copyright (C) 1994 DJ Delorie, see COPYING.DJ for details */
#include <msvcrt/stdlib.h>
#include <msvcrt/internal/tls.h>
/*-
* Copyright (c) 1980, 1983 The Regents of the University of California.
@ -32,11 +33,6 @@
#define THRESH 4 /* threshold for insertion */
#define MTHRESH 6 /* threshold for median */
static int (*qcmp)(const void *, const void *); /* the comparison routine */
static int qsz; /* size of each record */
static int thresh; /* THRESHold in chars */
static int mthresh; /* MTHRESHold in chars */
/*
* qst:
* Do a quicksort
@ -53,7 +49,7 @@ static int mthresh; /* MTHRESHold in chars */
*/
static void
qst(char *base, char *max)
qst(PTHREADDATA pThreadData, char *base, char *max)
{
char c, *i, *j, *jj;
int ii;
@ -71,20 +67,20 @@ qst(char *base, char *max)
*/
lo = max - base; /* number of elements as chars */
do {
mid = i = base + qsz * ((lo / qsz) >> 1);
if (lo >= mthresh)
mid = i = base + pThreadData->qsz * ((lo / pThreadData->qsz) >> 1);
if (lo >= pThreadData->mthresh)
{
j = (qcmp((jj = base), i) > 0 ? jj : i);
if (qcmp(j, (tmp = max - qsz)) > 0)
j = (pThreadData->qcmp((jj = base), i) > 0 ? jj : i);
if (pThreadData->qcmp(j, (tmp = max - pThreadData->qsz)) > 0)
{
/* switch to first loser */
j = (j == jj ? i : jj);
if (qcmp(j, tmp) < 0)
if (pThreadData->qcmp(j, tmp) < 0)
j = tmp;
}
if (j != i)
{
ii = qsz;
ii = pThreadData->qsz;
do {
c = *i;
*i++ = *j;
@ -95,18 +91,18 @@ qst(char *base, char *max)
/*
* Semi-standard quicksort partitioning/swapping
*/
for (i = base, j = max - qsz; ; )
for (i = base, j = max - pThreadData->qsz; ; )
{
while (i < mid && qcmp(i, mid) <= 0)
i += qsz;
while (i < mid && pThreadData->qcmp(i, mid) <= 0)
i += pThreadData->qsz;
while (j > mid)
{
if (qcmp(mid, j) <= 0)
if (pThreadData->qcmp(mid, j) <= 0)
{
j -= qsz;
j -= pThreadData->qsz;
continue;
}
tmp = i + qsz; /* value of i after swap */
tmp = i + pThreadData->qsz; /* value of i after swap */
if (i == mid)
{
/* j <-> mid, new mid is j */
@ -116,7 +112,7 @@ qst(char *base, char *max)
{
/* i <-> j */
jj = j;
j -= qsz;
j -= pThreadData->qsz;
}
goto swap;
}
@ -129,10 +125,10 @@ qst(char *base, char *max)
/* i <-> mid, new mid is i */
jj = mid;
tmp = mid = i; /* value of i after swap */
j -= qsz;
j -= pThreadData->qsz;
}
swap:
ii = qsz;
ii = pThreadData->qsz;
do {
c = *i;
*i++ = *jj;
@ -148,21 +144,21 @@ qst(char *base, char *max)
* (recursively or by branching) if the partition is
* of at least size THRESH.
*/
i = (j = mid) + qsz;
i = (j = mid) + pThreadData->qsz;
if ((lo = j - base) <= (hi = max - i))
{
if (lo >= thresh)
qst(base, j);
if (lo >= pThreadData->thresh)
qst(pThreadData, base, j);
base = i;
lo = hi;
}
else
{
if (hi >= thresh)
qst(i, max);
if (hi >= pThreadData->thresh)
qst(pThreadData, i, max);
max = j;
}
} while (lo >= thresh);
} while (lo >= pThreadData->thresh);
}
/*
@ -174,21 +170,25 @@ qst(char *base, char *max)
void
qsort(const void *base0, size_t n, size_t size, _pfunccmp_t compar)
{
PTHREADDATA pThreadData;
char *base = (char *)base0;
char c, *i, *j, *lo, *hi;
char *min, *max;
if (n <= 1)
return;
qsz = size;
qcmp = compar;
thresh = qsz * THRESH;
mthresh = qsz * MTHRESH;
max = base + n * qsz;
pThreadData = GetThreadData();
pThreadData->qsz = size;
pThreadData->qcmp = compar;
pThreadData->thresh = pThreadData->qsz * THRESH;
pThreadData->mthresh = pThreadData->qsz * MTHRESH;
max = base + n * pThreadData->qsz;
if (n >= THRESH)
{
qst(base, max);
hi = base + thresh;
qst(pThreadData, base, max);
hi = base + pThreadData->thresh;
}
else
{
@ -200,13 +200,13 @@ qsort(const void *base0, size_t n, size_t size, _pfunccmp_t compar)
* the first THRESH elements (or the first n if n < THRESH), finding
* the min, and swapping it into the first position.
*/
for (j = lo = base; (lo += qsz) < hi; )
if (qcmp(j, lo) > 0)
for (j = lo = base; (lo += pThreadData->qsz) < hi; )
if (pThreadData->qcmp(j, lo) > 0)
j = lo;
if (j != base)
{
/* swap j into place */
for (i = base, hi = base + qsz; i < hi; )
for (i = base, hi = base + pThreadData->qsz; i < hi; )
{
c = *j;
*j++ = *i;
@ -220,15 +220,15 @@ qsort(const void *base0, size_t n, size_t size, _pfunccmp_t compar)
* Then, do the standard insertion sort shift on a character at a time
* basis for each element in the frob.
*/
for (min = base; (hi = min += qsz) < max; )
for (min = base; (hi = min += pThreadData->qsz) < max; )
{
while (qcmp(hi -= qsz, min) > 0)
while (pThreadData->qcmp(hi -= pThreadData->qsz, min) > 0)
/* void */;
if ((hi += qsz) != min) {
for (lo = min + qsz; --lo >= min; )
if ((hi += pThreadData->qsz) != min) {
for (lo = min + pThreadData->qsz; --lo >= min; )
{
c = *lo;
for (i = j = lo; (j -= qsz) >= hi; i = j)
for (i = j = lo; (j -= pThreadData->qsz) >= hi; i = j)
*i = *j;
*i = c;
}