From 656f1fb2713abe2c5831056a977b2d7ba7b0dc5c Mon Sep 17 00:00:00 2001
From: Dmitry Stogov <dmitry@php.net>
Date: Mon, 4 Oct 2010 15:50:47 +0000
Subject: [PATCH] Bug #51155 (Unreasonable non-emalloc allocations of memory)

---
 Zend/zend_alloc.c | 66 +++++++++++++++++++++++++++++++++--------------
 1 file changed, 47 insertions(+), 19 deletions(-)

diff --git a/Zend/zend_alloc.c b/Zend/zend_alloc.c
index d89cd247a9..7bc531a86e 100644
--- a/Zend/zend_alloc.c
+++ b/Zend/zend_alloc.c
@@ -435,6 +435,7 @@ struct _zend_mm_heap {
 	zend_mm_free_block *free_buckets[ZEND_MM_NUM_BUCKETS*2];
 	zend_mm_free_block *large_free_buckets[ZEND_MM_NUM_BUCKETS];
 	zend_mm_free_block *rest_buckets[2];
+	int                 rest_count;
 #if ZEND_MM_CACHE_STAT
 	struct {
 		int count;
@@ -455,6 +456,10 @@ struct _zend_mm_heap {
 		sizeof(zend_mm_free_block*) * 2 - \
 		sizeof(zend_mm_small_free_block))
 
+#define ZEND_MM_REST_BLOCK ((zend_mm_free_block*)(zend_uintptr_t)(1))
+
+#define ZEND_MM_MAX_REST_BLOCKS 16
+
 #if ZEND_MM_COOKIES
 
 static unsigned int _zend_mm_cookie = 0;
@@ -711,23 +716,6 @@ static inline unsigned int zend_mm_low_bit(size_t _size)
 #endif
 }
 
-static inline void zend_mm_add_to_rest_list(zend_mm_heap *heap, zend_mm_free_block *mm_block)
-{
-	zend_mm_free_block *prev, *next;
-
-	ZEND_MM_SET_MAGIC(mm_block, MEM_BLOCK_FREED);
-
-	if (!ZEND_MM_SMALL_SIZE(ZEND_MM_FREE_BLOCK_SIZE(mm_block))) {
-		mm_block->parent = NULL;
-	}
-
-	prev = heap->rest_buckets[0];
-	next = prev->next_free_block;
-	mm_block->prev_free_block = prev;
-	mm_block->next_free_block = next;
-	prev->next_free_block = next->prev_free_block = mm_block;
-}
-
 static inline void zend_mm_add_to_free_list(zend_mm_heap *heap, zend_mm_free_block *mm_block)
 {
 	size_t size;
@@ -854,12 +842,45 @@ subst_block:
 					heap->free_bitmap &= ~(ZEND_MM_LONG_CONST(1) << index);
 				}
 			}
+		} else if (UNEXPECTED(mm_block->parent == ZEND_MM_REST_BLOCK)) {
+			heap->rest_count--;
 		} else if (UNEXPECTED(mm_block->parent != NULL)) {
 			goto subst_block;
 		}
 	}
 }
 
+static inline void zend_mm_add_to_rest_list(zend_mm_heap *heap, zend_mm_free_block *mm_block)
+{
+	zend_mm_free_block *prev, *next;
+
+	while (heap->rest_count >= ZEND_MM_MAX_REST_BLOCKS) {
+		zend_mm_free_block *p = heap->rest_buckets[1];
+
+		if (!ZEND_MM_SMALL_SIZE(ZEND_MM_FREE_BLOCK_SIZE(p))) {
+			heap->rest_count--;
+		}
+		prev = p->prev_free_block;
+		next = p->next_free_block;
+		prev->next_free_block = next;
+		next->prev_free_block = prev;
+		zend_mm_add_to_free_list(heap, p);
+	}
+
+	if (!ZEND_MM_SMALL_SIZE(ZEND_MM_FREE_BLOCK_SIZE(mm_block))) {
+		mm_block->parent = ZEND_MM_REST_BLOCK;
+		heap->rest_count++;
+	}
+
+	ZEND_MM_SET_MAGIC(mm_block, MEM_BLOCK_FREED);
+
+	prev = heap->rest_buckets[0];
+	next = prev->next_free_block;
+	mm_block->prev_free_block = prev;
+	mm_block->next_free_block = next;
+	prev->next_free_block = next->prev_free_block = mm_block;
+}
+
 static inline void zend_mm_init(zend_mm_heap *heap)
 {
 	zend_mm_free_block* p;
@@ -884,6 +905,7 @@ static inline void zend_mm_init(zend_mm_heap *heap)
 		heap->large_free_buckets[i] = NULL;
 	}
 	heap->rest_buckets[0] = heap->rest_buckets[1] = ZEND_MM_REST_BUCKET(heap);
+	heap->rest_count = 0;
 }
 
 static void zend_mm_del_segment(zend_mm_heap *heap, zend_mm_segment *segment)
@@ -1116,6 +1138,7 @@ ZEND_API zend_mm_heap *zend_mm_startup_ex(const zend_mm_mem_handlers *handlers,
 			}
 		}
 		mm_heap->rest_buckets[0] = mm_heap->rest_buckets[1] = ZEND_MM_REST_BUCKET(mm_heap);
+		mm_heap->rest_count = 0;
 
 		free(heap);
 		heap = mm_heap;
@@ -1674,8 +1697,13 @@ ZEND_API void zend_mm_shutdown(zend_mm_heap *heap, int full_shutdown, int silent
 			storage->handlers->compact(storage);
 		}
 		zend_mm_init(heap);
-		heap->real_size = 0;
-		heap->real_peak = 0;
+		if (heap->segments_list) {
+			heap->real_size = heap->segments_list->size;
+			heap->real_peak = heap->segments_list->size;
+		} else {
+			heap->real_size = 0;
+			heap->real_peak = 0;
+		}
 		heap->size = 0;
 		heap->peak = 0;
 		if (heap->segments_list) {
-- 
2.40.0