+++ /dev/null
---- psort.c.orig 2008-11-24 17:01:07.000000000 -0800
-+++ psort.c 2008-11-24 22:02:57.000000000 -0800
-@@ -1,3 +1,4 @@
-+/****************************************************************************/
- /*-
- * Copyright (c) 1992, 1993
- * The Regents of the University of California. All rights reserved.
-@@ -34,14 +35,22 @@ static char sccsid[] = "@(#)qsort.c 8.1
- __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_QSORT_R
-+#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_QSORT_B
-+#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));
-@@ -50,6 +59,83 @@ static inline void swapfunc(char *, cha
-
- #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".
- */
-@@ -88,7 +174,7 @@ swapfunc(a, b, n, swaptype)
-
- #define vecswap(a, b, n) if ((n) > 0) swapfunc(a, b, n, swaptype)
-
--#ifdef I_AM_QSORT_R
-+#ifdef I_AM_PSORT_R
- #define CMP(t, x, y) (cmp((t), (x), (y)))
- #else
- #define CMP(t, x, y) (cmp((x), (y)))
-@@ -96,13 +182,13 @@ swapfunc(a, b, n, swaptype)
-
- static inline char *
- med3(char *a, char *b, char *c,
--#ifdef I_AM_QSORT_B
-+#ifdef I_AM_PSORT_B
- cmp_t ^cmp,
- #else
- cmp_t *cmp,
- #endif
- void *thunk
--#ifndef I_AM_QSORT_R
-+#ifndef I_AM_PSORT_R
- __unused
- #endif
- )
-@@ -118,23 +204,25 @@ __unused
- #define DEPTH(x) (2 * (fls((int)(x)) - 1))
- #endif /* __LP64__ */
-
--#ifdef I_AM_QSORT_R
-+#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
--_qsort(void *a, size_t n, size_t es,
--#ifdef I_AM_QSORT_R
-+_psort(void *a, size_t n, size_t es,
-+#ifdef I_AM_PSORT_R
- void *thunk,
- #else
- #define thunk NULL
- #endif
--#ifdef I_AM_QSORT_B
-+#ifdef I_AM_PSORT_B
- cmp_t ^cmp,
- #else
- cmp_t *cmp,
- #endif
--int depth_limit)
-+int depth_limit, struct shared *shared)
- {
- char *pa, *pb, *pc, *pd, *pl, *pm, *pn;
- size_t d, r;
-@@ -143,9 +231,9 @@ int depth_limit)
-
- loop:
- if (depth_limit-- <= 0) {
--#ifdef I_AM_QSORT_B
-+#ifdef I_AM_PSORT_B
- heapsort_b(a, n, es, cmp);
--#elif defined(I_AM_QSORT_R)
-+#elif defined(I_AM_PSORT_R)
- __heapsort_r(a, n, es, thunk, cmp);
- #else
- heapsort(a, n, es, cmp);
-@@ -222,33 +310,135 @@ loop:
- }
-
- nevermind:
-- if ((r = pb - pa) > es)
--#ifdef I_AM_QSORT_R
-- _qsort(a, r / es, es, thunk, cmp, depth_limit);
-+ 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
-- _qsort(a, r / es, es, cmp, depth_limit);
-+ _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;
- }
--/* qsort(pn - r, r / es, es, cmp);*/
-+/* 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_QSORT_R
--qsort_r(void *a, size_t n, size_t es, void *thunk, cmp_t *cmp)
--#elif defined(I_AM_QSORT_B)
--qsort_b(void *a, size_t n, size_t es, cmp_t ^cmp)
-+#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
--qsort(void *a, size_t n, size_t es, cmp_t *cmp)
-+psort(void *a, size_t n, size_t es, cmp_t *cmp)
- #endif
- {
-- _qsort(a, n, es,
--#ifdef I_AM_QSORT_R
-- thunk,
-+ 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
-- cmp, DEPTH(n));
- }
projects / apple / libc.git / blobdiff