Define functions to get the number of used blocks.

1 files changed, 28 insertions, 17 deletions

diff --git a/mempool/include/mempool.h b/mempool/include/mempool.h
index de9ea4f..245173b 100644
--- a/mempool/include/mempool.h
+++ b/mempool/include/mempool.h
@@ -86,9 +86,15 @@
 #define mempool_get_block_index(POOL, BLOCK_PTR) \
   mempool_get_block_index_(&(POOL)->pool, BLOCK_PTR)
 
-/// Return the total capacity of the mempool in bytes.
+/// Return the block size in bytes.
+#define mempool_block_size_bytes(POOL) mempool_block_size_bytes_(&(POOL)->pool)
+
+/// Return the total capacity of the mempool.
 #define mempool_capacity(POOL) mempool_capacity_(&(POOL)->pool)
 
+/// Return the number of used blocks in the mempool.
+#define mempool_size(POOL) mempool_size_(&(POOL)->pool)
+
 /// Set whether to trap when attempting to allocate beyond capacity.
 #define mempool_enable_traps(POOL, enable) \
   mempool_enable_traps_(&(POOL)->pool, enable)
@@ -98,22 +104,24 @@
 /// The caller can use 'i' as the index of the current block.
 ///
 /// It is valid to mempool_free() the object at each step of the iteration.
-#define mempool_foreach(POOL, ITER, BODY)                                \
-  {                                                                      \
-    size_t i = (POOL)->pool.used;                                        \
-    do {                                                                 \
-      if ((POOL)->pool.block_info[i].used) {                             \
-        __typeof__((POOL)->object[0])* ITER =                            \
-            &(((__typeof__((POOL)->object[0])*)(POOL)->pool.blocks))[i]; \
-        (void)ITER;                                                      \
-        BODY;                                                            \
-      }                                                                  \
-      const size_t next = (POOL)->pool.block_info[i].next_used;          \
-      if (next == i) {                                                   \
-        break;                                                           \
-      }                                                                  \
-      i = next;                                                          \
-    } while (true);                                                      \
+#define mempool_foreach(POOL, ITER, BODY)                                  \
+  {                                                                        \
+    size_t i = (POOL)->pool.used;                                          \
+    if ((POOL)->pool.num_used_blocks > 0) {                                \
+      do {                                                                 \
+        if ((POOL)->pool.block_info[i].used) {                             \
+          __typeof__((POOL)->object[0])* ITER =                            \
+              &(((__typeof__((POOL)->object[0])*)(POOL)->pool.blocks))[i]; \
+          (void)ITER;                                                      \
+          BODY;                                                            \
+        }                                                                  \
+        const size_t next = (POOL)->pool.block_info[i].next_used;          \
+        if (next == i) {                                                   \
+          break;                                                           \
+        }                                                                  \
+        i = next;                                                          \
+      } while (true);                                                      \
+    }                                                                      \
   }
 
 // -----------------------------------------------------------------------------
@@ -133,6 +141,7 @@ typedef struct BlockInfo {
 typedef struct mempool {
   size_t     block_size_bytes;
   size_t     num_blocks;
+  size_t     num_used_blocks;
   size_t     head;    /// Points to the first block in the free list.
   size_t     used;    /// Points to the first block in the used list.
   bool       dynamic; /// True if blocks and info are dynamically-allocated.
@@ -161,5 +170,7 @@ void*  mempool_alloc_(mempool*);
 void   mempool_free_(mempool*, void** block_ptr);
 void*  mempool_get_block_(const mempool*, size_t block_index);
 size_t mempool_get_block_index_(const mempool*, const void* block);
+size_t mempool_block_size_bytes_(const mempool*);
 size_t mempool_capacity_(const mempool*);
+size_t mempool_size_(const mempool*);
 void   mempool_enable_traps_(mempool*, bool);