Adds the following functionality to memory pools:
- Lifecycle management functions (init, discard)
- Test whether a memory location is part of the managed pool
- Function to combine 2 pools
This also adds logic to track all memory allocations made by a memory
pool.
These functions will be used in a future commit in this commit series.
Signed-off-by: Jameson Miller <jam...@microsoft.com>
---
mem-pool.c | 114 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++---
mem-pool.h | 32 +++++++++++++++++
2 files changed, 142 insertions(+), 4 deletions(-)
diff --git a/mem-pool.c b/mem-pool.c
index 389d7af447..a495885c4b 100644
--- a/mem-pool.c
+++ b/mem-pool.c
@@ -5,6 +5,8 @@
#include "cache.h"
#include "mem-pool.h"
+#define BLOCK_GROWTH_SIZE 1024*1024 - sizeof(struct mp_block);
+
static struct mp_block *mem_pool_alloc_block(struct mem_pool *mem_pool, size_t
block_alloc)
{
struct mp_block *p;
@@ -19,6 +21,60 @@ static struct mp_block *mem_pool_alloc_block(struct mem_pool
*mem_pool, size_t b
return p;
}
+static void *mem_pool_alloc_custom(struct mem_pool *mem_pool, size_t
block_alloc)
+{
+ char *p;
+ ALLOC_GROW(mem_pool->custom, mem_pool->nr + 1, mem_pool->alloc);
+ ALLOC_GROW(mem_pool->custom_end, mem_pool->nr_end + 1,
mem_pool->alloc_end);
+
+ p = xmalloc(block_alloc);
+ mem_pool->custom[mem_pool->nr++] = p;
+ mem_pool->custom_end[mem_pool->nr_end++] = p + block_alloc;
+
+ mem_pool->pool_alloc += block_alloc;
+
+ return mem_pool->custom[mem_pool->nr];
+}
+
+void mem_pool_init(struct mem_pool **mem_pool, size_t initial_size)
+{
+ if (!(*mem_pool))
+ {
+ *mem_pool = xmalloc(sizeof(struct mem_pool));
+ (*mem_pool)->pool_alloc = 0;
+ (*mem_pool)->mp_block = NULL;
+ (*mem_pool)->block_alloc = BLOCK_GROWTH_SIZE;
+ (*mem_pool)->custom = NULL;
+ (*mem_pool)->nr = 0;
+ (*mem_pool)->alloc = 0;
+ (*mem_pool)->custom_end = NULL;
+ (*mem_pool)->nr_end = 0;
+ (*mem_pool)->alloc_end = 0;
+
+ if (initial_size > 0)
+ mem_pool_alloc_block(*mem_pool, initial_size);
+ }
+}
+
+void mem_pool_discard(struct mem_pool *mem_pool)
+{
+ int i;
+ struct mp_block *block, *block_to_free;
+ for (block = mem_pool->mp_block; block;)
+ {
+ block_to_free = block;
+ block = block->next_block;
+ free(block_to_free);
+ }
+
+ for (i = 0; i < mem_pool->nr; i++)
+ free(mem_pool->custom[i]);
+
+ free(mem_pool->custom);
+ free(mem_pool->custom_end);
+ free(mem_pool);
+}
+
void *mem_pool_alloc(struct mem_pool *mem_pool, size_t len)
{
struct mp_block *p;
@@ -33,10 +89,8 @@ void *mem_pool_alloc(struct mem_pool *mem_pool, size_t len)
break;
if (!p) {
- if (len >= (mem_pool->block_alloc / 2)) {
- mem_pool->pool_alloc += len;
- return xmalloc(len);
- }
+ if (len >= (mem_pool->block_alloc / 2))
+ return mem_pool_alloc_custom(mem_pool, len);
p = mem_pool_alloc_block(mem_pool, mem_pool->block_alloc);
}
@@ -53,3 +107,55 @@ void *mem_pool_calloc(struct mem_pool *mem_pool, size_t
count, size_t size)
memset(r, 0, len);
return r;
}
+
+int mem_pool_contains(struct mem_pool *mem_pool, void *mem)
+{
+ int i;
+ struct mp_block *p;
+
+ /* Check if memory is allocated in a block */
+ for (p = mem_pool->mp_block; p; p = p->next_block)
+ if ((mem >= ((void *)p->space)) &&
+ (mem < ((void *)p->end)))
+ return 1;
+
+ /* Check if memory is allocated in custom block */
+ for (i = 0; i < mem_pool->nr; i++)
+ if ((mem >= mem_pool->custom[i]) &&
+ (mem < mem_pool->custom_end[i]))
+ return 1;
+
+ return 0;
+}
+
+void mem_pool_combine(struct mem_pool *dst, struct mem_pool *src)
+{
+ int i;
+ struct mp_block **tail = &dst->mp_block;
+
+ /* Find pointer of dst's last block (if any) */
+ while (*tail)
+ tail = &(*tail)->next_block;
+
+ /* Append the blocks from src to dst */
+ *tail = src->mp_block;
+
+ /* Combine custom allocations */
+ ALLOC_GROW(dst->custom, dst->nr + src->nr, dst->alloc);
+ ALLOC_GROW(dst->custom_end, dst->nr_end + src->nr_end, dst->alloc_end);
+
+ for (i = 0; i < src->nr; i++) {
+ dst->custom[dst->nr++] = src->custom[i];
+ dst->custom_end[dst->nr_end++] = src->custom_end[i];
+ }
+
+ dst->pool_alloc += src->pool_alloc;
+ src->pool_alloc = 0;
+ src->mp_block = NULL;
+ src->custom = NULL;
+ src->nr = 0;
+ src->alloc = 0;
+ src->custom_end = NULL;
+ src->nr_end = 0;
+ src->alloc_end = 0;
+}
diff --git a/mem-pool.h b/mem-pool.h
index 829ad58ecf..34df4fa709 100644
--- a/mem-pool.h
+++ b/mem-pool.h
@@ -19,8 +19,27 @@ struct mem_pool {
/* The total amount of memory allocated by the pool. */
size_t pool_alloc;
+
+ /*
+ * Array of pointers to "custom size" memory allocations.
+ * This is used for "large" memory allocations.
+ * The *_end variables are used to track the range of memory
+ * allocated.
+ */
+ void **custom, **custom_end;
+ int nr, nr_end, alloc, alloc_end;
};
+/*
+ * Initialize mem_pool specified initial.
+ */
+void mem_pool_init(struct mem_pool **mem_pool, size_t initial_size);
+
+/*
+ * Discard a memory pool and free all the memory it is responsible for.
+ */
+void mem_pool_discard(struct mem_pool *mem_pool);
+
/*
* Alloc memory from the mem_pool.
*/
@@ -31,4 +50,17 @@ void *mem_pool_alloc(struct mem_pool *pool, size_t len);
*/
void *mem_pool_calloc(struct mem_pool *pool, size_t count, size_t size);
+/*
+ * Move the memory associated with the 'src' pool to the 'dst' pool. The 'src'
+ * pool will be empty and not contain any memory. It still needs to be free'd
+ * with a call to `mem_pool_discard`.
+ */
+void mem_pool_combine(struct mem_pool *dst, struct mem_pool *src);
+
+/*
+ * Check if a memory pointed at by 'mem' is part of the range of
+ * memory managed by the specified mem_pool.
+ */
+int mem_pool_contains(struct mem_pool *mem_pool, void *mem);
+
#endif
--
2.14.3
