- Almost completely implement realloc(). It now resizes in place when

- possible.

diff --git a/Zend/zend_mm.c b/Zend/zend_mm.c
index 5a6d9d2461be8823cd5fa097b0e7653a41730b5c..f5e591852746444716daf92a9b4d5590008a75fd 100644 (file)
--- a/Zend/zend_mm.c
+++ b/Zend/zend_mm.c
@@ -89,6 +89,34 @@ static inline void zend_mm_remove_from_free_list(zend_mm_heap *heap, zend_mm_fre
        }
 }
 
+static inline void zend_mm_create_new_free_block(zend_mm_heap *heap, zend_mm_block *mm_block, size_t true_size)
+{
+       int remaining_size;
+       zend_mm_free_block *new_free_block;
+
+       /* calculate sizes */
+       remaining_size = mm_block->size - true_size;
+
+       if (remaining_size < ZEND_MM_ALIGNED_FREE_HEADER_SIZE) {
+               /* keep best_fit->size as is, it'll include this extra space */
+               return;
+       }
+
+       /* prepare new free block */
+       mm_block->size = true_size;
+       new_free_block = (zend_mm_free_block *) ZEND_MM_BLOCK_AT(mm_block, mm_block->size);
+
+       new_free_block->type = ZEND_MM_FREE_BLOCK;
+       new_free_block->size = remaining_size;
+       new_free_block->prev_size = true_size;
+
+       /* update the next block's prev_size */
+       ZEND_MM_BLOCK_AT(new_free_block, new_free_block->size)->prev_size = new_free_block->size;
+
+       /* add the new free block to the free list */
+       zend_mm_add_to_free_list(heap, new_free_block);
+       return;
+}
 
 zend_bool zend_mm_add_memory_block(zend_mm_heap *heap, size_t block_size)
 {
@@ -157,8 +185,7 @@ void zend_mm_shutdown(zend_mm_heap *heap)
 void *zend_mm_alloc(zend_mm_heap *heap, size_t size)
 {
        size_t true_size;
-       zend_mm_free_block *p, *best_fit=NULL, *new_free_block;
-       size_t remaining_size;
+       zend_mm_free_block *p, *best_fit=NULL;
 
        /* The max() can probably be optimized with an if() which checks more specific cases */
        true_size = MAX(ZEND_MM_ALIGNED_SIZE(size)+ZEND_MM_ALIGNED_HEADER_SIZE, ZEND_MM_ALIGNED_FREE_HEADER_SIZE);
@@ -187,27 +214,7 @@ void *zend_mm_alloc(zend_mm_heap *heap, size_t size)
        /* remove from free list */
        zend_mm_remove_from_free_list(heap, best_fit);
 
-       /* calculate sizes */
-       remaining_size = best_fit->size - true_size;
-
-       if (remaining_size < ZEND_MM_ALIGNED_FREE_HEADER_SIZE) {
-               /* keep best_fit->size as is, it'll include this extra space */
-               return ZEND_MM_DATA_OF(best_fit);
-       }
-
-       /* prepare new free block */
-       best_fit->size = true_size;
-       new_free_block = (zend_mm_free_block *) ZEND_MM_BLOCK_AT(best_fit, best_fit->size);
-
-       new_free_block->type = ZEND_MM_FREE_BLOCK;
-       new_free_block->size = remaining_size;
-       new_free_block->prev_size = true_size;
-
-       /* update the next block's prev_size */
-       ZEND_MM_BLOCK_AT(new_free_block, new_free_block->size)->prev_size = new_free_block->size;
-
-       /* add the new free block to the free list */
-       zend_mm_add_to_free_list(heap, new_free_block);
+       zend_mm_create_new_free_block(heap, (zend_mm_block *) best_fit, true_size);
 
        return ZEND_MM_DATA_OF(best_fit);
 }
@@ -249,18 +256,35 @@ void zend_mm_free(zend_mm_heap *heap, void *p)
        }
 }
 
-/* This still needs optimizing to truely resize when possible */
 void *zend_mm_realloc(zend_mm_heap *heap, void *p, size_t size)
 {
-       void *ptr;
        zend_mm_block *mm_block = ZEND_MM_HEADER_OF(p);
+       zend_mm_block *next_block;
        size_t true_size = MAX(ZEND_MM_ALIGNED_SIZE(size)+ZEND_MM_ALIGNED_HEADER_SIZE, ZEND_MM_ALIGNED_FREE_HEADER_SIZE);
 
        if (true_size <= mm_block->size) {
+               zend_mm_create_new_free_block(heap, mm_block, true_size);
+               /* We don't yet merge this free block with the following one */
+
                return p;
        }
-       ptr = zend_mm_alloc(heap, size);
-       memcpy(ptr, p, mm_block->size - ZEND_MM_ALIGNED_HEADER_SIZE);
-       zend_mm_free(heap, p);
-       return ptr;
+
+       next_block = ZEND_MM_BLOCK_AT(mm_block, mm_block->size);
+
+       if (next_block->type != ZEND_MM_FREE_BLOCK || (mm_block->size + next_block->size < true_size)) {
+               void *ptr;
+       
+               ptr = zend_mm_alloc(heap, size);
+               memcpy(ptr, p, mm_block->size - ZEND_MM_ALIGNED_HEADER_SIZE);
+               zend_mm_free(heap, p);
+               return ptr;
+       }
+
+       zend_mm_remove_from_free_list(heap, (zend_mm_free_block *) next_block);
+       mm_block->size += next_block->size;
+       
+       zend_mm_create_new_free_block(heap, mm_block, true_size);
+       /* We don't yet merge this free block with the following one */
+
+       return p;
 }