Added another note.

[libucw.git] / lib / sorter / array.c

diff --git a/lib/sorter/array.c b/lib/sorter/array.c
index 68ada9015968a8dc7c495a93c47cbe388c4595fb..e1805245ff4b1a609903fecca20120f7a8014416 100644 (file)
--- a/lib/sorter/array.c
+++ b/lib/sorter/array.c
@@ -75,6 +75,15 @@ static uns asort_threads_use_count;
 static uns asort_threads_ready;
 static struct worker_pool asort_thread_pool;
 
+static uns
+rs_estimate_stack(void)
+{
+  // Stack space needed by the recursive radix-sorter
+  uns ctrsize = sizeof(uns) * (1 << CONFIG_UCW_RADIX_SORTER_BITS);
+  uns maxdepth = (64 / CONFIG_UCW_RADIX_SORTER_BITS) + 1;
+  return ctrsize * maxdepth;
+}
+
 void
 asort_start_threads(uns run)
 {
@@ -82,8 +91,11 @@ asort_start_threads(uns run)
   asort_threads_use_count++;
   if (run && !asort_threads_ready)
     {
-      ASORT_TRACE("Initializing thread pool (%d threads)", sorter_threads);
+      // XXX: If somebody overrides the radix-sorter parameters to insane values,
+      // he also should override the stack size to insane values.
+      asort_thread_pool.stack_size = default_thread_stack_size + rs_estimate_stack();
       asort_thread_pool.num_threads = sorter_threads;
+      ASORT_TRACE("Initializing thread pool (%d threads, %dK stack)", sorter_threads, asort_thread_pool.stack_size >> 10);
       worker_pool_init(&asort_thread_pool);
       asort_threads_ready = 1;
     }
@@ -320,7 +332,7 @@ rs_radix(struct asort_context *ctx, void *array, void *buffer, uns num_elts, uns
       uns n = cnt[i] - pos;
       if (!n)
        continue;
-      if (n * ctx->elt_size < sorter_thread_threshold)
+      if (n * ctx->elt_size < sorter_thread_threshold || shift < ASORT_MIN_SHIFT)
        {
          struct rs_work *w = ep_alloc(ctx->eltpool);
          w->w.priority = 0;
@@ -425,11 +437,13 @@ asort_run(struct asort_context *ctx)
        {
          ASORT_XTRACE(2, "Decided to use parallel quicksort");
          threaded_quicksort(ctx);
-         return;
        }
+      else
 #endif
-      ASORT_XTRACE(2, "Decided to use sequential quicksort");
-      ctx->quicksort(ctx->array, ctx->num_elts);
+       {
+         ASORT_XTRACE(2, "Decided to use sequential quicksort");
+         ctx->quicksort(ctx->array, ctx->num_elts);
+       }
     }
   else
     {
@@ -441,9 +455,12 @@ asort_run(struct asort_context *ctx)
          threaded_radixsort(ctx, swap);
          return;
        }
+      else
 #endif
-      ASORT_XTRACE(2, "Decided to use sequential radix-sort (swap=%d)", swap);
-      asort_radix(ctx, ctx->array, ctx->buffer, ctx->num_elts, ctx->hash_bits, swap);
+       {
+         ASORT_XTRACE(2, "Decided to use sequential radix-sort (swap=%d)", swap);
+         asort_radix(ctx, ctx->array, ctx->buffer, ctx->num_elts, ctx->hash_bits, swap);
+       }
       if (swap)
        ctx->array = ctx->buffer;
     }