+#ifdef CONFIG_UCW_THREADS
+
+#include "lib/threads.h"
+#include "lib/workqueue.h"
+#include "lib/eltpool.h"
+
+static uns asort_threads_use_count;
+static uns asort_threads_ready;
+static struct worker_pool asort_thread_pool;
+
+void
+asort_start_threads(uns run)
+{
+ ucwlib_lock();
+ asort_threads_use_count++;
+ if (run && !asort_threads_ready)
+ {
+ SORT_XTRACE(2, "Initializing thread pool (%d threads)", sorter_threads);
+ asort_thread_pool.num_threads = sorter_threads;
+ worker_pool_init(&asort_thread_pool);
+ asort_threads_ready = 1;
+ }
+ ucwlib_unlock();
+}
+
+void
+asort_stop_threads(void)
+{
+ ucwlib_lock();
+ if (!--asort_threads_use_count && asort_threads_ready)
+ {
+ SORT_XTRACE(2, "Shutting down thread pool");
+ worker_pool_cleanup(&asort_thread_pool);
+ asort_threads_ready = 0;
+ }
+ ucwlib_unlock();
+}
+
+struct qs_work {
+ struct work w;
+ struct asort_context *ctx;
+ void *array;
+ uns num_elts;
+ int left, right;
+#define LR_UNDEF -100
+};
+
+static void
+qs_handle_work(struct worker_thread *thr UNUSED, struct work *ww)
+{
+ struct qs_work *w = (struct qs_work *) ww;
+
+ DBG("Thread %d: got %d elts", thr->id, w->num_elts);
+ if (w->num_elts * w->ctx->elt_size < sorter_thread_threshold)
+ {
+ w->ctx->quicksort(w->array, w->num_elts);
+ w->left = w->right = LR_UNDEF;
+ }
+ else
+ w->ctx->quicksplit(w->array, w->num_elts, &w->left, &w->right);
+ DBG("Thread %d: returning l=%d r=%d", thr->id, w->left, w->right);
+}
+
+static struct qs_work *
+qs_alloc_work(struct asort_context *ctx)
+{
+ struct qs_work *w = ep_alloc(ctx->eltpool);
+ w->w.priority = 0;
+ w->w.go = qs_handle_work;
+ w->ctx = ctx;
+ return w;
+}
+
+static void
+threaded_quicksort(struct asort_context *ctx)
+{
+ struct work_queue q;
+ struct qs_work *v, *w;
+
+ asort_start_threads(1);
+ work_queue_init(&asort_thread_pool, &q);
+ ctx->eltpool = ep_new(sizeof(struct qs_work), 1000);
+
+ w = qs_alloc_work(ctx);
+ w->array = ctx->array;
+ w->num_elts = ctx->num_elts;
+ work_submit(&q, &w->w);
+
+ while (v = (struct qs_work *) work_wait(&q))
+ {
+ if (v->left != LR_UNDEF)
+ {
+ if (v->right > 0)
+ {
+ w = qs_alloc_work(ctx);
+ w->array = v->array;
+ w->num_elts = v->right + 1;
+ w->w.priority = v->w.priority + 1;
+ work_submit(&q, &w->w);
+ }
+ if (v->left < (int)v->num_elts - 1)
+ {
+ w = qs_alloc_work(ctx);
+ w->array = v->array + v->left * ctx->elt_size;
+ w->num_elts = v->num_elts - v->left;
+ w->w.priority = v->w.priority + 1;
+ work_submit(&q, &w->w);
+ }
+ }
+ ep_free(ctx->eltpool, v);
+ }
+
+ ep_delete(ctx->eltpool);
+ work_queue_cleanup(&q);
+ asort_stop_threads();
+}
+
+struct rs_work {
+ struct work w;
+ struct asort_context *ctx;
+ void *in, *out;
+ uns num_elts;
+ uns shift;
+ uns swap_output;
+ uns cnt[0];
+};
+
+static void
+rs_count(struct worker_thread *thr UNUSED, struct work *ww)
+{
+ struct rs_work *w = (struct rs_work *) ww;
+
+ DBG("Thread %d: Counting %d items, shift=%d", thr->id, w->num_elts, w->shift);
+ w->ctx->radix_count(w->in, w->num_elts, w->cnt, w->shift);
+ DBG("Thread %d: Counting done", thr->id);
+}
+
+static void
+rs_split(struct worker_thread *thr UNUSED, struct work *ww)
+{
+ struct rs_work *w = (struct rs_work *) ww;
+
+ DBG("Thread %d: Splitting %d items, shift=%d", thr->id, w->num_elts, w->shift);
+ w->ctx->radix_split(w->in, w->out, w->num_elts, w->cnt, w->shift);
+ DBG("Thread %d: Splitting done", thr->id);
+}
+
+static void
+rs_finish(struct worker_thread *thr UNUSED, struct work *ww)
+{
+ struct rs_work *w = (struct rs_work *) ww;
+
+ DBG("Thread %d: Finishing %d items, shift=%d", thr->id, w->num_elts, w->shift);
+ if (w->shift < ASORT_MIN_SHIFT || w->num_elts < ASORT_MIN_RADIX)
+ {
+ w->ctx->quicksort(w->out, w->num_elts);
+ if (!w->swap_output)
+ memcpy(w->in, w->out, w->num_elts * w->ctx->elt_size);
+ }
+ else
+ asort_radix(w->ctx, w->out, w->in, w->num_elts, w->shift, !w->swap_output);
+ DBG("Thread %d: Finishing done", thr->id);
+}
+
+static void
+rs_radix(struct asort_context *ctx, void *array, void *buffer, uns num_elts, uns hash_bits, uns swapped_output)
+{
+ uns buckets = (1 << ctx->radix_bits);
+ uns shift = (hash_bits > ctx->radix_bits) ? (hash_bits - ctx->radix_bits) : 0;
+ uns cnt[buckets];
+ uns blksize = num_elts / sorter_threads;
+ DBG(">>> n=%d h=%d s=%d blk=%d sw=%d", num_elts, hash_bits, shift, blksize, swapped_output);
+
+ // Start parallel counting
+ void *iptr = array;
+ for (uns i=0; i<sorter_threads; i++)
+ {
+ struct rs_work *w = ctx->rs_works[i];
+ w->w.priority = 0;
+ w->w.go = rs_count;
+ w->ctx = ctx;
+ w->in = iptr;
+ w->out = ctx->buffer;
+ w->num_elts = blksize;
+ if (i == sorter_threads-1)
+ w->num_elts += num_elts % sorter_threads;
+ w->shift = shift;
+ iptr += w->num_elts * ctx->elt_size;
+ work_submit(ctx->rs_work_queue, &w->w);
+ }
+
+ // Get bucket sizes from the counts
+ bzero(cnt, sizeof(cnt));
+ for (uns i=0; i<sorter_threads; i++)
+ {
+ struct rs_work *w = (struct rs_work *) work_wait(ctx->rs_work_queue);
+ ASSERT(w);
+ for (uns j=0; j<buckets; j++)
+ cnt[j] += w->cnt[j];
+ }
+
+ // Calculate bucket starts
+ uns pos = 0;
+ for (uns i=0; i<buckets; i++)
+ {
+ uns j = cnt[i];
+ cnt[i] = pos;
+ pos += j;
+ }
+ ASSERT(pos == num_elts);
+
+ // Start parallel splitting
+ for (uns i=0; i<sorter_threads; i++)
+ {
+ struct rs_work *w = ctx->rs_works[i];
+ w->w.go = rs_split;
+ for (uns j=0; j<buckets; j++)
+ {
+ uns k = w->cnt[j];
+ w->cnt[j] = cnt[j];
+ cnt[j] += k;
+ }
+ work_submit(ctx->rs_work_queue, &w->w);
+ }
+ ASSERT(cnt[buckets-1] == num_elts);
+
+ // Wait for splits to finish
+ while (work_wait(ctx->rs_work_queue))
+ ;
+
+ // Recurse on buckets
+ pos = 0;
+ for (uns i=0; i<buckets; i++)
+ {
+ uns n = cnt[i] - pos;
+ if (n < sorter_thread_threshold)
+ {
+ struct rs_work *w = ep_alloc(ctx->eltpool);
+ w->w.priority = 0;
+ w->w.go = rs_finish;
+ w->ctx = ctx;
+ w->in = array;
+ w->out = buffer;
+ w->num_elts = n;
+ w->shift = shift;
+ w->swap_output = swapped_output;
+ clist_add_tail(&ctx->rs_bits, &w->w.n);
+ DBG("Scheduling block %d+%d", pos, n);
+ }
+ else
+ rs_radix(ctx, buffer, array, n, shift, !swapped_output);
+ pos = cnt[i];
+ array += n * ctx->elt_size;
+ buffer += n * ctx->elt_size;
+ }
+}
+
+static void
+threaded_radixsort(struct asort_context *ctx)
+{
+ struct work_queue q;
+
+ asort_start_threads(1);
+ work_queue_init(&asort_thread_pool, &q);
+
+ // Prepare work structures for counting and splitting.
+ // We use big_alloc(), because we want to avoid cacheline aliasing between threads.
+ ctx->rs_work_queue = &q;
+ ctx->rs_works = alloca(sizeof(struct rs_work *) * sorter_threads);
+ for (uns i=0; i<sorter_threads; i++)
+ ctx->rs_works[i] = big_alloc(sizeof(struct rs_work) + sizeof(uns) * (1 << ctx->radix_bits));
+
+ // Prepare work structures for all remaining small bits which will be sorted later.
+ clist_init(&ctx->rs_bits);
+ ctx->eltpool = ep_new(sizeof(struct rs_work), 1000);
+
+ // Do the big splitting
+ // FIXME: Set the swap bit carefully.
+ rs_radix(ctx, ctx->array, ctx->buffer, ctx->num_elts, ctx->hash_bits, 0);
+ for (uns i=0; i<sorter_threads; i++)
+ big_free(ctx->rs_works[i], sizeof(struct rs_work) + sizeof(uns) * (1 << ctx->radix_bits));
+
+ // Finish the small blocks
+ struct rs_work *w, *tmp;
+ CLIST_WALK_DELSAFE(w, ctx->rs_bits, tmp)
+ work_submit(&q, &w->w);
+ while (work_wait(&q))
+ ;
+
+ ep_delete(ctx->eltpool);
+ work_queue_cleanup(&q);
+ asort_stop_threads();
+}
+
+#else
+
+void asort_start_threads(uns run UNUSED) { }
+void asort_stop_threads(void) { }
+
+#endif
+
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