-/****************************************************************************/
-/*-
- * 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.
- * 4. 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.
- */
-
-#if defined(LIBC_SCCS) && !defined(lint)
-static char sccsid[] = "@(#)qsort.c 8.1 (Berkeley) 6/4/93";
-#endif /* LIBC_SCCS and not lint */
-#include <sys/cdefs.h>
-__FBSDID("$FreeBSD: src/lib/libc/stdlib/qsort.c,v 1.15 2008/01/14 09:21:34 das Exp $");
-
-#include <stdlib.h>
-#include <pthread.h>
-#include <dispatch/dispatch.h>
-#include <stddef.h>
-#include <string.h>
-#include <libkern/OSAtomic.h>
-#include <sys/mman.h>
-#include <errno.h>
-#define __APPLE_API_PRIVATE
-#include <machine/cpu_capabilities.h>
-
-#ifdef I_AM_PSORT_R
-typedef int cmp_t(void *, const void *, const void *);
-#else
-typedef int cmp_t(const void *, const void *);
-#endif
-#ifdef I_AM_PSORT_B
-static inline char *med3(char *, char *, char *, cmp_t ^, void *) __attribute__((always_inline));
-#else
-static inline char *med3(char *, char *, char *, cmp_t *, void *) __attribute__((always_inline));
-#endif
-static inline void swapfunc(char *, char *, int, int) __attribute__((always_inline));
-
-#define min(a, b) (a) < (b) ? a : b
-
-#define NARGS ((PAGESIZE - offsetof(struct page, args)) / sizeof(union args))
-#define PAGESIZE 4096
-#define PARALLEL_MIN_SIZE 2000 /* determine heuristically */
-
-struct shared; /* forward reference */
-union args {
- union args *next;
- struct {
- struct shared *shared;
- void *a;
- size_t n;
- int depth_limit;
- } /* anonymous */;
-};
-
-struct page {
- struct page *next;
- union args args[0];
-};
-
-struct shared {
- char *who;
- union args *freelist;
- struct page *pagelist;
-#ifdef I_AM_PSORT_R
- void *thunk;
-#endif
-#ifdef I_AM_PSORT_B
- cmp_t ^cmp;
-#else
- cmp_t *cmp;
-#endif
- size_t es;
- size_t turnoff;
- dispatch_queue_t queue;
- pthread_cond_t cond;
- pthread_mutex_t mutex;
- OSSpinLock sharedlock;
- int count;
-};
-
-static union args *
-getargs(struct shared *shared)
-{
- union args *args;
-
- OSSpinLockLock(&shared->sharedlock);
- if(!shared->freelist) {
- struct page *page;
- union args *prev;
- int i;
- if((page = (struct page *)mmap(NULL, PAGESIZE, PROT_READ|PROT_WRITE, MAP_ANON|MAP_PRIVATE, -1, 0)) == NULL)
- return NULL;
- page->next = shared->pagelist;
- shared->pagelist = page;
- prev = NULL;
- for(args = page->args, i = NARGS; i > 0; args++, i--) {
- args->next = prev;
- prev = args;
- }
- shared->freelist = prev;
- }
- args = shared->freelist;
- shared->freelist = args->next;
- OSSpinLockUnlock(&shared->sharedlock);
- return args;
-}
-
-static void
-returnargs(struct shared *shared, union args *args)
-{
- OSSpinLockLock(&shared->sharedlock);
- args->next = shared->freelist;
- shared->freelist = args;
- OSSpinLockUnlock(&shared->sharedlock);
-}
-
-/*
- * Qsort routine from Bentley & McIlroy's "Engineering a Sort Function".
- */
-#define swapcode(TYPE, parmi, parmj, n) { \
- long i = (n) / sizeof (TYPE); \
- TYPE *pi = (TYPE *) (parmi); \
- TYPE *pj = (TYPE *) (parmj); \
- do { \
- TYPE t = *pi; \
- *pi++ = *pj; \
- *pj++ = t; \
- } while (--i > 0); \
-}
-
-#define SWAPINIT(a, es) swaptype = ((char *)a - (char *)0) % sizeof(long) || \
- es % sizeof(long) ? 2 : es == sizeof(long)? 0 : 1;
-
-static inline void
-swapfunc(a, b, n, swaptype)
- char *a, *b;
- int n, 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 *)(a); \
- *(long *)(a) = *(long *)(b); \
- *(long *)(b) = t; \
- } else \
- swapfunc(a, b, es, swaptype)
-
-#define vecswap(a, b, n) if ((n) > 0) swapfunc(a, b, n, swaptype)
-
-#ifdef I_AM_PSORT_R
-#define CMP(t, x, y) (cmp((t), (x), (y)))
-#else
-#define CMP(t, x, y) (cmp((x), (y)))
-#endif
-
-static inline char *
-med3(char *a, char *b, char *c,
-#ifdef I_AM_PSORT_B
-cmp_t ^cmp,
-#else
-cmp_t *cmp,
-#endif
-void *thunk
-#ifndef I_AM_PSORT_R
-__unused
-#endif
-)
-{
- 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 __LP64__
-#define DEPTH(x) (2 * (flsl((long)(x)) - 1))
-#else /* !__LP64__ */
-#define DEPTH(x) (2 * (fls((int)(x)) - 1))
-#endif /* __LP64__ */
-
-#ifdef I_AM_PSORT_R
-int __heapsort_r(void *, size_t, size_t, void *, int (*)(void *, const void *, const void *));
-#endif
-
-static void _psort_parallel(void *x);
-
-static void
-_psort(void *a, size_t n, size_t es,
-#ifdef I_AM_PSORT_R
-void *thunk,
-#else
-#define thunk NULL
-#endif
-#ifdef I_AM_PSORT_B
-cmp_t ^cmp,
-#else
-cmp_t *cmp,
-#endif
-int depth_limit, struct shared *shared)
-{
- char *pa, *pb, *pc, *pd, *pl, *pm, *pn;
- size_t d, r;
- int cmp_result;
- int swaptype, swap_cnt;
-
-loop:
- if (depth_limit-- <= 0) {
-#ifdef I_AM_PSORT_B
- heapsort_b(a, n, es, cmp);
-#elif defined(I_AM_PSORT_R)
- __heapsort_r(a, n, es, thunk, cmp);
-#else
- heapsort(a, n, es, cmp);
-#endif
- return;
- }
- 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(thunk, pl - es, pl) > 0;
- pl -= es)
- swap(pl, pl - es);
- return;
- }
- pm = (char *)a + (n / 2) * es;
- if (n > 7) {
- pl = a;
- pn = (char *)a + (n - 1) * es;
- if (n > 40) {
- d = (n / 8) * es;
- 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, thunk);
- }
- swap(a, pm);
- pa = pb = (char *)a + es;
-
- pc = pd = (char *)a + (n - 1) * es;
- for (;;) {
- while (pb <= pc && (cmp_result = CMP(thunk, pb, a)) <= 0) {
- if (cmp_result == 0) {
- swap_cnt = 1;
- swap(pa, pb);
- pa += es;
- }
- pb += es;
- }
- while (pb <= pc && (cmp_result = CMP(thunk, pc, a)) >= 0) {
- if (cmp_result == 0) {
- swap_cnt = 1;
- swap(pc, pd);
- pd -= es;
- }
- pc -= es;
- }
- if (pb > pc)
- break;
- swap(pb, pc);
- swap_cnt = 1;
- 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 (swap_cnt == 0) { /* Switch to insertion sort */
- r = 1 + n / 4; /* n >= 7, so r >= 2 */
- for (pm = (char *)a + es; pm < (char *)a + n * es; pm += es)
- for (pl = pm;
- pl > (char *)a && CMP(thunk, pl - es, pl) > 0;
- pl -= es) {
- swap(pl, pl - es);
- if (++swap_cnt > r) goto nevermind;
- }
- return;
- }
-
-nevermind:
- if ((r = pb - pa) > es) {
- r /= es;
- if (shared && r > shared->turnoff) {
- union args *args = getargs(shared);
-
- if (args == NULL)
- LIBC_ABORT("%s: getargs: %s", shared->who, strerror(errno));
- args->shared = shared;
- args->a = a;
- args->n = r;
- args->depth_limit = depth_limit;
- OSAtomicIncrement32(&shared->count);
- dispatch_async_f(shared->queue, args, _psort_parallel);
- } else {
-#ifdef I_AM_PSORT_R
- _psort(a, r, es, thunk, cmp, depth_limit, NULL);
-#else
- _psort(a, r, es, cmp, depth_limit, NULL);
-#endif
- }
- }
- if ((r = pd - pc) > es) {
- /* Iterate rather than recurse to save stack space */
- a = pn - r;
- n = r / es;
- goto loop;
- }
-/* psort(pn - r, r / es, es, cmp);*/
-}
-
-static void
-_psort_parallel(void *x)
-{
- union args *args = (union args *)x;
- struct shared *shared = args->shared;
-
- _psort(args->a, args->n, shared->es,
-#ifdef I_AM_PSORT_R
- shared->thunk,
-#endif
- shared->cmp, args->depth_limit, shared);
- returnargs(shared, args);
- if(OSAtomicDecrement32(&shared->count) <= 0) {
- pthread_mutex_lock(&shared->mutex);
- pthread_cond_signal(&shared->cond);
- pthread_mutex_unlock(&shared->mutex);
- }
-}
-
-/* fast, approximate integer square root */
-static size_t
-isqrt(size_t x)
-{
- size_t s = 1L << (flsl(x) / 2);
- return (s + x / s) / 2;
-}
-
-void
-#ifdef I_AM_PSORT_R
-psort_r(void *a, size_t n, size_t es, void *thunk, cmp_t *cmp)
-#elif defined(I_AM_PSORT_B)
-psort_b(void *a, size_t n, size_t es, cmp_t ^cmp)
-#else
-psort(void *a, size_t n, size_t es, cmp_t *cmp)
-#endif
-{
- if (n >= PARALLEL_MIN_SIZE && _NumCPUs() > 1) {
- struct shared shared;
- union args *args;
-
- bzero(&shared, sizeof(shared));
- shared.sharedlock = OS_SPINLOCK_INIT;
- if ((args = getargs(&shared)) != NULL) {
- struct page *p, *pp;
-#ifdef I_AM_PSORT_R
- shared.who = "psort_r";
- shared.thunk = thunk;
-#elif defined(I_AM_PSORT_B)
- shared.who = "psort_b";
-#else
- shared.who = "psort";
-#endif
- shared.cmp = cmp;
- shared.es = es;
- shared.queue = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0);
- shared.cond = (pthread_cond_t)PTHREAD_COND_INITIALIZER;
- shared.mutex = (pthread_mutex_t)PTHREAD_MUTEX_INITIALIZER;
- args->a = a;
- args->n = n;
- args->depth_limit = DEPTH(n);
- args->shared = &shared;
- /*
- * The turnoff value is the size of a partition that,
- * below which, we stop doing in parallel, and just do
- * in the current thread. The value of sqrt(n) was
- * determined heuristically. There is a smaller
- * dependence on the slowness of the comparison
- * function, and there might be a dependence on the
- * number of processors, but the algorithm has not been
- * determined. Because the sensitivity to the turnoff
- * value is relatively low, we use a fast, approximate
- * integer square root routine that is good enough for
- * this purpose.
- */
- shared.turnoff = isqrt(n);
- OSAtomicIncrement32(&shared.count);
- _psort_parallel(args);
-
- /* wait for queue to drain */
- pthread_mutex_lock(&shared.mutex);
- while(shared.count > 0)
- pthread_cond_wait(&shared.cond, &shared.mutex);
-
- pthread_mutex_unlock(&shared.mutex);
- pthread_mutex_destroy(&shared.mutex);
- pthread_cond_destroy(&shared.cond);
- for(p = shared.pagelist; p; p = pp) {
- pp = p->next;
- munmap(p, PAGESIZE);
- }
- return;
- }
- }
- /* Just call qsort */
-#ifdef I_AM_PSORT_R
- qsort_r(a, n, es, thunk, cmp);
-#elif defined(I_AM_PSORT_B)
- qsort_b(a, n, es, cmp);
-#else
- qsort(a, n, es, cmp);
-#endif
-}
projects / apple / libc.git / blobdiff