util: add a memory pool for equally sized memory allocations

malloc/free are in O(1).

src/gallium/auxiliary/Makefile

@@ -124,6 +124,7 @@ C_SOURCES = \
 	util/u_linear.c \
 	util/u_network.c \
 	util/u_math.c \
+	util/u_mempool.c \
 	util/u_mm.c \
 	util/u_rect.c \
 	util/u_ringbuffer.c \

src/gallium/auxiliary/SConscript

@@ -172,6 +172,7 @@ source = [
     'util/u_keymap.c',
     'util/u_network.c',
     'util/u_math.c',
+    'util/u_mempool.c',
     'util/u_mm.c',
     'util/u_rect.c',
     'util/u_resource.c',

src/gallium/auxiliary/util/u_mempool.c

@@ -0,0 +1,173 @@
+/*
+ * 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. */
+
+#include "util/u_mempool.h"
+
+#include "util/u_math.h"
+#include "util/u_memory.h"
+#include "util/u_simple_list.h"
+
+#include <stdio.h>
+
+#define UTIL_MEMPOOL_MAGIC 0xcafe4321
+
+struct util_mempool_block_body {};
+
+/* The block is either allocated memory or free space. */
+struct util_mempool_block {
+   /* The header. */
+   /* The first next free block. */
+   struct util_mempool_block *next_free;
+
+   intptr_t magic;
+
+   /* The block begins here. */
+   struct util_mempool_block_body body;
+
+   /* Memory after the last member is dedicated to the block itself.
+    * The allocated size is always larger than this structure. */
+};
+
+static struct util_mempool_block *
+util_mempool_get_block(struct util_mempool *pool,
+                       struct util_mempool_page *page, unsigned index)
+{
+   return (struct util_mempool_block*)
+         ((uint8_t*)&page->body + (pool->block_size * index));
+}
+
+static void util_mempool_add_new_page(struct util_mempool *pool)
+{
+   struct util_mempool_page *page;
+   struct util_mempool_block *block;
+   int i;
+
+   page = MALLOC(pool->page_size);
+   insert_at_tail(&pool->list, page);
+
+   /* Mark all blocks as free. */
+   for (i = 0; i < pool->num_blocks-1; i++) {
+      block = util_mempool_get_block(pool, page, i);
+      block->next_free = util_mempool_get_block(pool, page, i+1);
+      block->magic = UTIL_MEMPOOL_MAGIC;
+   }
+
+   block = util_mempool_get_block(pool, page, pool->num_blocks-1);
+   block->next_free = pool->first_free;
+   pool->first_free = util_mempool_get_block(pool, page, 0);
+   pool->num_pages++;
+
+#if 0
+   fprintf(stderr, "New page! Num of pages: %i\n", pool->num_pages);
+#endif
+}
+
+static void *util_mempool_malloc_st(struct util_mempool *pool)
+{
+   struct util_mempool_block *block;
+
+   if (!pool->first_free)
+      util_mempool_add_new_page(pool);
+
+   block = pool->first_free;
+   assert(block->magic == UTIL_MEMPOOL_MAGIC);
+   pool->first_free = block->next_free;
+
+   return &block->body;
+}
+
+static void util_mempool_free_st(struct util_mempool *pool, void *ptr)
+{
+   struct util_mempool_block dummy;
+   struct util_mempool_block *block =
+         (struct util_mempool_block*)
+         ((uint8_t*)ptr - ((uint8_t*)&dummy.body - (uint8_t*)&dummy));
+
+   assert(block->magic == UTIL_MEMPOOL_MAGIC);
+   block->next_free = pool->first_free;
+   pool->first_free = block;
+}
+
+static void *util_mempool_malloc_mt(struct util_mempool *pool)
+{
+   void *mem;
+
+   pipe_mutex_lock(pool->mutex);
+   mem = util_mempool_malloc_st(pool);
+   pipe_mutex_unlock(pool->mutex);
+   return mem;
+}
+
+static void util_mempool_free_mt(struct util_mempool *pool, void *ptr)
+{
+   pipe_mutex_lock(pool->mutex);
+   util_mempool_free_st(pool, ptr);
+   pipe_mutex_unlock(pool->mutex);
+}
+
+void util_mempool_set_thread_safety(struct util_mempool *pool,
+                                    enum util_mempool_threading threading)
+{
+   pool->threading = threading;
+
+   if (threading) {
+      pipe_mutex_init(pool->mutex);
+      pool->malloc = util_mempool_malloc_mt;
+      pool->free = util_mempool_free_mt;
+   } else {
+      pool->malloc = util_mempool_malloc_st;
+      pool->free = util_mempool_free_st;
+   }
+}
+
+void util_mempool_create(struct util_mempool *pool,
+                         unsigned item_size,
+                         unsigned num_blocks,
+                         enum util_mempool_threading threading)
+{
+   item_size = align(item_size, sizeof(intptr_t));
+
+   pool->num_pages = 0;
+   pool->num_blocks = num_blocks;
+   pool->block_size = sizeof(struct util_mempool_block) + item_size;
+   pool->block_size = align(pool->block_size, sizeof(intptr_t));
+   pool->page_size = sizeof(struct util_mempool_page) +
+                     num_blocks * pool->block_size;
+   pool->first_free = NULL;
+
+   make_empty_list(&pool->list);
+
+   util_mempool_set_thread_safety(pool, threading);
+}
+
+void util_mempool_destroy(struct util_mempool *pool)
+{
+   struct util_mempool_page *page, *temp;
+
+   foreach_s(page, temp, &pool->list) {
+      remove_from_list(page);
+      FREE(page);
+   }
+
+   if (pool->threading)
+      pipe_mutex_destroy(pool->mutex);
+}

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