util: add a memory pool for equally sized memory allocations

malloc/free are in O(1).

1 files changed, 92 insertions, 0 deletions

diff --git a/src/gallium/auxiliary/util/u_mempool.h b/src/gallium/auxiliary/util/u_mempool.h
new file mode 100644
index 0000000000..b8d2aaefb6
--- /dev/null
+++ b/src/gallium/auxiliary/util/u_mempool.h
@@ -0,0 +1,92 @@
+/*
+ * Copyright 2010 Marek Olšák <maraeo@gmail.com>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * on the rights to use, copy, modify, merge, publish, distribute, sub
+ * license, and/or sell copies of the Software, and to permit persons to whom
+ * the Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHOR(S) AND/OR THEIR SUPPLIERS BE LIABLE FOR ANY CLAIM,
+ * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
+ * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
+ * USE OR OTHER DEALINGS IN THE SOFTWARE. */
+
+/**
+ * @file
+ * Simple memory pool for equally sized memory allocations.
+ * util_mempool_malloc and util_mempool_free are in O(1).
+ *
+ * Good for allocations which have very low lifetime and are allocated
+ * and freed very often. Use a profiler first!
+ *
+ * Candidates: get_transfer, user_buffer_create
+ *
+ * @author Marek Olšák
+ */
+
+#ifndef U_MEMPOOL_H
+#define U_MEMPOOL_H
+
+#include "os/os_thread.h"
+
+enum util_mempool_threading {
+   UTIL_MEMPOOL_SINGLETHREADED = FALSE,
+   UTIL_MEMPOOL_MULTITHREADED = TRUE
+};
+
+struct util_mempool_page_body {};
+
+/* The page is an array of blocks (allocations). */
+struct util_mempool_page {
+   /* The header (linked-list pointers). */
+   struct util_mempool_page *prev, *next;
+
+   /* The page begins here. */
+   struct util_mempool_page_body body;
+
+   /* Memory after the last member is dedicated to the page itself.
+    * The allocated size is always larger than this structure. */
+};
+
+struct util_mempool {
+   /* Public members. */
+   void *(*malloc)(struct util_mempool *pool);
+   void (*free)(struct util_mempool *pool, void *ptr);
+
+   /* Private members. */
+   struct util_mempool_block *first_free;
+
+   struct util_mempool_page list;
+
+   unsigned block_size;
+   unsigned page_size;
+   unsigned num_blocks;
+   unsigned num_pages;
+   enum util_mempool_threading threading;
+
+   pipe_mutex mutex;
+};
+
+void util_mempool_create(struct util_mempool *pool,
+                         unsigned item_size,
+                         unsigned num_blocks,
+                         enum util_mempool_threading threading);
+
+void util_mempool_destroy(struct util_mempool *pool);
+
+void util_mempool_set_thread_safety(struct util_mempool *pool,
+                                    enum util_mempool_threading threading);
+
+#define util_mempool_malloc(pool)    (pool)->malloc(pool)
+#define util_mempool_free(pool, ptr) (pool)->free(pool, ptr)
+
+#endif