heap: add functions to get heap runtime statistics

add functions to get the sys_heap runtime statistics,
include total free bytes, total allocated bytes.

Signed-off-by: Chen Peng1 <peng1.chen@intel.com>

include/sys/sys_heap.h

@@ -61,6 +61,25 @@ struct z_heap_stress_result {
 	uint64_t accumulated_in_use_bytes;
 };
 
+#ifdef CONFIG_SYS_HEAP_RUNTIME_STATS
+
+struct sys_heap_runtime_stats {
+	size_t free_bytes;
+	size_t allocated_bytes;
+};
+
+/**
+ * @brief Get the runtime statistics of a sys_heap
+ *
+ * @param heap Pointer to specified sys_heap
+ * @param stats_t Pointer to struct to copy statistics into
+ * @return -EINVAL if null pointers, otherwise 0
+ */
+int sys_heap_runtime_stats_get(struct sys_heap *heap,
+		struct sys_heap_runtime_stats *stats);
+
+#endif
+
 /** @brief Initialize sys_heap
  *
  * Initializes a sys_heap struct to manage the specified memory.

lib/os/Kconfig

@@ -46,6 +46,11 @@ config SYS_HEAP_ALLOC_LOOPS
 	  keeps the maximum runtime at a tight bound so that the heap
 	  is useful in locked or ISR contexts.
 
+config SYS_HEAP_RUNTIME_STATS
+	bool "System heap runtime statistics"
+	help
+	  Gather system heap runtime statistics.
+
 choice
 	prompt "Supported heap sizes"
 	depends on !64BIT

lib/os/heap-validate.c

@@ -386,3 +386,20 @@ void sys_heap_print_info(struct sys_heap *heap, bool dump_chunks)
 {
 	heap_print_info(heap->heap, dump_chunks);
 }
+
+#ifdef CONFIG_SYS_HEAP_RUNTIME_STATS
+
+int sys_heap_runtime_stats_get(struct sys_heap *heap,
+		struct sys_heap_runtime_stats *stats)
+{
+	if ((heap == NULL) || (stats == NULL)) {
+		return -EINVAL;
+	}
+
+	stats->free_bytes = heap->heap->free_bytes;
+	stats->allocated_bytes = heap->heap->allocated_bytes;
+
+	return 0;
+}
+
+#endif

lib/os/heap.c

@@ -38,6 +38,10 @@ static void free_list_remove_bidx(struct z_heap *h, chunkid_t c, int bidx)
 		set_next_free_chunk(h, first, second);
 		set_prev_free_chunk(h, second, first);
 	}
+
+#ifdef CONFIG_SYS_HEAP_RUNTIME_STATS
+	h->free_bytes -= chunksz_to_bytes(h, chunk_size(h, c));
+#endif
 }
 
 static void free_list_remove(struct z_heap *h, chunkid_t c)
@@ -72,6 +76,10 @@ static void free_list_add_bidx(struct z_heap *h, chunkid_t c, int bidx)
 		set_next_free_chunk(h, first, c);
 		set_prev_free_chunk(h, second, c);
 	}
+
+#ifdef CONFIG_SYS_HEAP_RUNTIME_STATS
+	h->free_bytes += chunksz_to_bytes(h, chunk_size(h, c));
+#endif
 }
 
 static void free_list_add(struct z_heap *h, chunkid_t c)
@@ -164,6 +172,9 @@ void sys_heap_free(struct sys_heap *heap, void *mem)
 		 mem);
 
 	set_chunk_used(h, c, false);
+#ifdef CONFIG_SYS_HEAP_RUNTIME_STATS
+	h->allocated_bytes -= chunksz_to_bytes(h, chunk_size(h, c));
+#endif
 	free_chunk(h, c);
 }
 
@@ -251,6 +262,9 @@ void *sys_heap_alloc(struct sys_heap *heap, size_t bytes)
 	}
 
 	set_chunk_used(h, c, true);
+#ifdef CONFIG_SYS_HEAP_RUNTIME_STATS
+	h->allocated_bytes += chunksz_to_bytes(h, chunk_size(h, c));
+#endif
 	return chunk_mem(h, c);
 }
 
@@ -318,6 +332,9 @@ void *sys_heap_aligned_alloc(struct sys_heap *heap, size_t align, size_t bytes)
 	}
 
 	set_chunk_used(h, c, true);
+#ifdef CONFIG_SYS_HEAP_RUNTIME_STATS
+	h->allocated_bytes += chunksz_to_bytes(h, chunk_size(h, c));
+#endif
 	return mem;
 }
 
@@ -353,6 +370,10 @@ void *sys_heap_aligned_realloc(struct sys_heap *heap, void *ptr,
 		return ptr;
 	} else if (chunk_size(h, c) > chunks_need) {
 		/* Shrink in place, split off and free unused suffix */
+#ifdef CONFIG_SYS_HEAP_RUNTIME_STATS
+		h->allocated_bytes -=
+			(chunk_size(h, c) - chunks_need) * CHUNK_UNIT;
+#endif
 		split_chunks(h, c, c + chunks_need);
 		set_chunk_used(h, c, true);
 		free_chunk(h, c + chunks_need);
@@ -362,6 +383,10 @@ void *sys_heap_aligned_realloc(struct sys_heap *heap, void *ptr,
 		/* Expand: split the right chunk and append */
 		chunkid_t split_size = chunks_need - chunk_size(h, c);
 
+#ifdef CONFIG_SYS_HEAP_RUNTIME_STATS
+		h->allocated_bytes += split_size * CHUNK_UNIT;
+#endif
+
 		free_list_remove(h, rc);
 
 		if (split_size < chunk_size(h, rc)) {
@@ -415,6 +440,11 @@ void sys_heap_init(struct sys_heap *heap, void *mem, size_t bytes)
 	h->end_chunk = heap_sz;
 	h->avail_buckets = 0;
 
+#ifdef CONFIG_SYS_HEAP_RUNTIME_STATS
+	h->free_bytes = 0;
+	h->allocated_bytes = 0;
+#endif
+
 	int nb_buckets = bucket_idx(h, heap_sz) + 1;
 	chunksz_t chunk0_size = chunksz(sizeof(struct z_heap) +
 				     nb_buckets * sizeof(struct z_heap_bucket));

lib/os/heap.h

@@ -69,6 +69,10 @@ struct z_heap {
 	chunkid_t chunk0_hdr[2];
 	chunkid_t end_chunk;
 	uint32_t avail_buckets;
+#ifdef CONFIG_SYS_HEAP_RUNTIME_STATS
+	size_t free_bytes;
+	size_t allocated_bytes;
+#endif
 	struct z_heap_bucket buckets[0];
 };