[sgen] Have an allocated block list for fixed-heap M&S, too.

It turns out we iterate over all allocated blocks often enough that
the way we did it for fixed-heap Mark&Sweep (iterating over all blocks
and jumping over the non-allocated ones) slows us down considerably.
So, use the same allocated block list as "regular" Mark&Sweep, which
also unifies the code a bit.

diff --git a/mono/metadata/sgen-marksweep.c b/mono/metadata/sgen-marksweep.c
index 955b9f3bdcafe73d4efec2ab715fe254dc804751..03141735c96a095310df7abd9f8414ae464158c3 100644 (file)
--- a/mono/metadata/sgen-marksweep.c
+++ b/mono/metadata/sgen-marksweep.c
@@ -88,9 +88,8 @@ struct _MSBlockInfo {
 #ifdef FIXED_HEAP
        unsigned int used : 1;
        unsigned int zeroed : 1;
-#else
-       MSBlockInfo *next;
 #endif
+       MSBlockInfo *next;
        char *block;
        void **free_list;
        MSBlockInfo *next_free;
@@ -195,28 +194,20 @@ static gboolean have_swept;
 
 #define ptr_in_nursery(p)      (SGEN_PTR_IN_NURSERY ((p), nursery_bits, nursery_start, nursery_end))
 
+/* all allocated blocks in the system */
+static MSBlockInfo *all_blocks;
+
 #ifdef FIXED_HEAP
 /* non-allocated block free-list */
 static MSBlockInfo *empty_blocks = NULL;
 #else
 /* non-allocated block free-list */
 static void *empty_blocks = NULL;
-/* all allocated blocks in the system */
-static MSBlockInfo *all_blocks;
 static int num_empty_blocks = 0;
 #endif
 
-#ifdef FIXED_HEAP
-#define FOREACH_BLOCK(bl)      {                                       \
-               int __block_i;                                          \
-               for (__block_i = 0; __block_i < ms_heap_num_blocks; ++__block_i) { \
-                       (bl) = &block_infos [__block_i];                \
-                       if (!(bl)->used) continue;
-#define END_FOREACH_BLOCK      }}
-#else
 #define FOREACH_BLOCK(bl)      for ((bl) = all_blocks; (bl); (bl) = (bl)->next) {
 #define END_FOREACH_BLOCK      }
-#endif
 
 static int num_major_sections = 0;
 /* one free block list for each block object size */
@@ -465,14 +456,13 @@ check_block_free_list (MSBlockInfo *block, int size, gboolean pinned)
                /* the block must not be in the empty_blocks list */
                for (b = empty_blocks; b; b = b->next_free)
                        g_assert (b != block);
-#else
+#endif
                /* the block must be in the all_blocks list */
                for (b = all_blocks; b; b = b->next) {
                        if (b == block)
                                break;
                }
                g_assert (b == block);
-#endif
        }
 }
 
@@ -589,10 +579,8 @@ ms_alloc_block (int size_index, gboolean pinned, gboolean has_references)
        info->next_free = free_blocks [size_index];
        free_blocks [size_index] = info;
 
-#ifndef FIXED_HEAP
        info->next = all_blocks;
        all_blocks = info;
-#endif
 
        ++num_major_sections;
        return TRUE;
@@ -1158,11 +1146,8 @@ static void
 ms_sweep (void)
 {
        int i;
-#ifdef FIXED_HEAP
-       int j;
-#else
        MSBlockInfo **iter;
-#endif
+
        /* statistics for evacuation */
        int *slots_available = alloca (sizeof (int) * num_block_obj_sizes);
        int *slots_used = alloca (sizeof (int) * num_block_obj_sizes);
@@ -1180,25 +1165,15 @@ ms_sweep (void)
        }
 
        /* traverse all blocks, free and zero unmarked objects */
-#ifdef FIXED_HEAP
-       for (j = 0; j < ms_heap_num_blocks; ++j) {
-               MSBlockInfo *block = &block_infos [j];
-#else
        iter = &all_blocks;
        while (*iter) {
                MSBlockInfo *block = *iter;
-#endif
                int count;
                gboolean have_live = FALSE;
                gboolean has_pinned;
                int obj_index;
                int obj_size_index;
 
-#ifdef FIXED_HEAP
-               if (!block->used)
-                       continue;
-#endif
-
                obj_size_index = block->obj_size_index;
 
                has_pinned = block->has_pinned;
@@ -1244,9 +1219,7 @@ ms_sweep (void)
                                slots_available [obj_size_index] += count;
                        }
 
-#ifndef FIXED_HEAP
                        iter = &block->next;
-#endif
 
                        /*
                         * If there are free slots in the block, add
@@ -1265,12 +1238,13 @@ ms_sweep (void)
                         * Blocks without live objects are removed from the
                         * block list and freed.
                         */
+                       *iter = block->next;
+
 #ifdef FIXED_HEAP
                        ms_free_block (block);
 #else
-                       *iter = block->next;
-
                        ms_free_block (block->block);
+
                        mono_sgen_free_internal (block, INTERNAL_MEM_MS_BLOCK_INFO);
 #endif