samples: sys_heap: extend with `k_heap_array_get`

Extend the sample with a demonstration of `k_heap_array_get`.

Signed-off-by: Jordan Yates <jordan@embeint.com>

samples/basic/sys_heap/README.rst

@@ -33,9 +33,14 @@ Sample Output
 
 .. code-block:: console
 
-    System heap sample
-
-    allocated 0, free 196, max allocated 0, heap size 256
-    allocated 156, free 36, max allocated 156, heap size 256
-    allocated 100, free 92, max allocated 156, heap size 256
-    allocated 0, free 196, max allocated 156, heap size 256
+   System heap sample
+
+   allocated 0, free 196, max allocated 0, heap size 256
+   allocated 156, free 36, max allocated 156, heap size 256
+   allocated 100, free 92, max allocated 156, heap size 256
+   allocated 0, free 196, max allocated 156, heap size 256
+   1 static heap(s) allocated:
+         0 - address 0x80552a8 allocated 12, free 180, max allocated 12, heap size 256
+   2 heap(s) allocated (including static):
+         0 - address 0x80552a8 allocated 12, free 180, max allocated 12, heap size 256
+         1 - address 0x805530c allocated 0, free 196, max allocated 156, heap size 256

samples/basic/sys_heap/src/main.c

@@ -15,6 +15,7 @@ static char heap_mem[HEAP_SIZE];
 static struct sys_heap heap;
 
 static void print_sys_memory_stats(struct sys_heap *);
+static void print_static_heaps(void);
 static void print_all_heaps(void);
 
 int main(void)
@@ -35,7 +36,17 @@ int main(void)
 	sys_heap_free(&heap, p);
 	print_sys_memory_stats(&heap);
 
+	/* Allocate from our custom k_heap to make the output
+	 * more interesting and prevent compiler optimisations from
+	 * discarding it.
+	 */
+	p = k_heap_alloc(&my_kernel_heap, 10, K_FOREVER);
+
+	print_static_heaps();
 	print_all_heaps();
+
+	/* Cleanup memory */
+	k_heap_free(&my_kernel_heap, p);
 	return 0;
 }
 
@@ -50,16 +61,30 @@ static void print_sys_memory_stats(struct sys_heap *hp)
 		stats.max_allocated_bytes, HEAP_SIZE);
 }
 
+static void print_static_heaps(void)
+{
+	struct k_heap *ha;
+	int n;
+
+	n = k_heap_array_get(&ha);
+	printk("%d static heap(s) allocated:\n", n);
+
+	for (int i = 0; i < n; i++) {
+		printk("\t%d - address %p ", i, &ha[i]);
+		print_sys_memory_stats(&ha[i].heap);
+	}
+}
+
 static void print_all_heaps(void)
 {
 	struct sys_heap **ha;
-	size_t i, n;
+	int n;
 
 	n = sys_heap_array_get(&ha);
-	printk("There are %zu heaps allocated:\n", n);
+	printk("%d heap(s) allocated (including static):\n", n);
 
-	for (i = 0; i < n; i++) {
-		printk("\t%zu - address %p ", i, ha[i]);
+	for (int i = 0; i < n; i++) {
+		printk("\t%d - address %p ", i, ha[i]);
 		print_sys_memory_stats(ha[i]);
 	}
 }