clearing the mempool can now keep more then a single element reserved.

1 files changed, 67 insertions, 35 deletions

diff --git a/source/blender/blenlib/intern/BLI_mempool.c b/source/blender/blenlib/intern/BLI_mempool.c
index 8a05ade76ef..1c3c1cd8d7a 100644
--- a/source/blender/blenlib/intern/BLI_mempool.c
+++ b/source/blender/blenlib/intern/BLI_mempool.c
@@ -87,6 +87,7 @@ struct BLI_mempool {
 	/* keeps aligned to 16 bits */
 
 	BLI_freenode *free;    /* free element list. Interleaved into chunk datas. */
+	int maxchunks;         /* use to know how many chunks to keep for BLI_mempool_clear */
 	int totused;           /* number of elements currently in use */
 #ifdef USE_TOTALLOC
 	int totalloc;          /* number of elements allocated in total */
@@ -101,6 +102,14 @@ struct BLI_mempool {
 #  define CHUNK_DATA(chunk) (CHECK_TYPE_INLINE(chunk, BLI_mempool_chunk *), (void *)((chunk) + 1))
 #endif
 
+/**
+ * \return the number of chunks to allocate based on how many elements are needed.
+ */
+BLI_INLINE int mempool_maxchunks(const int totelem, const int pchunk)
+{
+	return totelem / pchunk + 1;
+}
+
 static BLI_mempool_chunk *mempool_chunk_alloc(BLI_mempool *pool)
 {
 	BLI_mempool_chunk *mpchunk;
@@ -183,35 +192,37 @@ static BLI_freenode *mempool_chunk_add(BLI_mempool *pool, BLI_mempool_chunk *mpc
 	return curnode;
 }
 
-static void mempool_chunk_free_all(BLI_mempool *pool)
+static void mempool_chunk_free(BLI_mempool_chunk *mpchunk, const int flag)
 {
-	BLI_mempool_chunk *mpchunk, *mpchunk_next;
-
-	if (pool->flag & BLI_MEMPOOL_SYSMALLOC) {
-		for (mpchunk = pool->chunks.first; mpchunk; mpchunk = mpchunk_next) {
-			mpchunk_next = mpchunk->next;
+	if (flag & BLI_MEMPOOL_SYSMALLOC) {
 #ifdef USE_DATA_PTR
-			free(CHUNK_DATA(mpchunk));
+		free(CHUNK_DATA(mpchunk));
 #endif
-			free(mpchunk);
-		}
+		free(mpchunk);
 	}
 	else {
-		for (mpchunk = pool->chunks.first; mpchunk; mpchunk = mpchunk_next) {
-			mpchunk_next = mpchunk->next;
 #ifdef USE_DATA_PTR
-			MEM_freeN(CHUNK_DATA(mpchunk));
+		MEM_freeN(CHUNK_DATA(mpchunk));
 #endif
-			MEM_freeN(mpchunk);
-		}
+		MEM_freeN(mpchunk);
 	}
-	pool->chunks.first = pool->chunks.last = NULL;
+}
+
+static void mempool_chunk_free_all(ListBase *chunks, const int flag)
+{
+	BLI_mempool_chunk *mpchunk, *mpchunk_next;
+
+	for (mpchunk = chunks->first; mpchunk; mpchunk = mpchunk_next) {
+		mpchunk_next = mpchunk->next;
+		mempool_chunk_free(mpchunk, flag);
+	}
+	chunks->first = chunks->last = NULL;
 }
 
 BLI_mempool *BLI_mempool_create(int esize, int totelem, int pchunk, int flag)
 {
 	BLI_mempool *pool = NULL;
-	BLI_freenode *lasttail = NULL, *curnode = NULL;
+	BLI_freenode *lasttail = NULL;
 	int i, maxchunks;
 
 	/* allocate the pool structure */
@@ -234,29 +245,23 @@ BLI_mempool *BLI_mempool_create(int esize, int totelem, int pchunk, int flag)
 		pool->esize = esize;
 	}
 
+	maxchunks = mempool_maxchunks(totelem, pchunk);
+
 	pool->flag = flag;
 	pool->pchunk = pchunk;
 	pool->csize = esize * pchunk;
 	pool->chunks.first = pool->chunks.last = NULL;
 	pool->free = NULL;  /* mempool_chunk_add assigns */
+	pool->maxchunks = maxchunks;
 #ifdef USE_TOTALLOC
 	pool->totalloc = 0;
 #endif
 	pool->totused = 0;
 
-	maxchunks = totelem / pchunk + 1;
-	if (maxchunks == 0) {
-		maxchunks = 1;
-	}
-
 	/* allocate the actual chunks */
 	for (i = 0; i < maxchunks; i++) {
 		BLI_mempool_chunk *mpchunk = mempool_chunk_alloc(pool);
-
-		curnode = mempool_chunk_add(pool, mpchunk, lasttail);
-
-		/* set the end of this chunks memory to the new tail for next iteration */
-		lasttail = curnode;
+		lasttail = mempool_chunk_add(pool, mpchunk, lasttail);
 	}
 
 	return pool;
@@ -338,7 +343,7 @@ void BLI_mempool_free(BLI_mempool *pool, void *addr)
 		BLI_mempool_chunk *first = pool->chunks.first;
 
 		BLI_remlink(&pool->chunks, first);
-		mempool_chunk_free_all(pool);
+		mempool_chunk_free_all(&pool->chunks, pool->flag);
 		BLI_addtail(&pool->chunks, first);
 #ifdef USE_TOTALLOC
 		pool->totalloc = pool->pchunk;
@@ -504,22 +509,49 @@ void *BLI_mempool_iterstep(BLI_mempool_iter *iter)
 
 #endif
 
-void BLI_mempool_clear(BLI_mempool *pool)
+void BLI_mempool_clear_ex(BLI_mempool *pool, const int totelem_reserve)
 {
-	BLI_mempool_chunk *first = pool->chunks.first;
+	BLI_mempool_chunk *mpchunk;
+	BLI_mempool_chunk *mpchunk_next;
+	int maxchunks;
+
+	ListBase chunks_temp;
+	BLI_freenode *lasttail = NULL;
+
+	if (totelem_reserve == -1) {
+		maxchunks = pool->maxchunks;
+	}
+	else {
+		maxchunks = mempool_maxchunks(totelem_reserve, pool->pchunk);
+	}
 
-	BLI_remlink(&pool->chunks, first);
+	/* free all after pool->maxchunks  */
 
-	mempool_chunk_free_all(pool);
+	for (mpchunk = BLI_findlink(&pool->chunks, maxchunks); mpchunk; mpchunk = mpchunk_next)  {
+		mpchunk_next = mpchunk->next;
+		BLI_remlink(&pool->chunks, mpchunk);
+		mempool_chunk_free(mpchunk, pool->flag);
+	}
 
-	/* important for re-initializing */
+	/* re-initialize */
+	pool->free = NULL;
 	pool->totused = 0;
 #ifdef USE_TOTALLOC
 	pool->totalloc = 0;
 #endif
-	pool->free = NULL;
 
-	mempool_chunk_add(pool, first, NULL);
+	chunks_temp = pool->chunks;
+	pool->chunks.first = pool->chunks.last = NULL;
+
+	while ((mpchunk = chunks_temp.first)) {
+		BLI_remlink(&chunks_temp, mpchunk);
+		lasttail = mempool_chunk_add(pool, mpchunk, lasttail);
+	}
+}
+
+void BLI_mempool_clear(BLI_mempool *pool)
+{
+	return BLI_mempool_clear_ex(pool, -1);
 }
 
 /**
@@ -527,7 +559,7 @@ void BLI_mempool_clear(BLI_mempool *pool)
  */
 void BLI_mempool_destroy(BLI_mempool *pool)
 {
-	mempool_chunk_free_all(pool);
+	mempool_chunk_free_all(&pool->chunks, pool->flag);
 
 	if (pool->flag & BLI_MEMPOOL_SYSMALLOC) {
 		free(pool);