kernel: Add k_heap_calloc

Add the k_heap_calloc function. The
equivalent of the standard calloc for
the Zephyr kernel.

Signed-off-by: Simone Orru <simone.orru@secomind.com>

include/zephyr/kernel.h

@@ -5511,6 +5511,31 @@ void *k_heap_aligned_alloc(struct k_heap *h, size_t align, size_t bytes,
 void *k_heap_alloc(struct k_heap *h, size_t bytes,
 		k_timeout_t timeout) __attribute_nonnull(1);
 
+/**
+ * @brief Allocate and initialize memory for an array of objects from a k_heap
+ *
+ * Allocates memory for an array of num objects of size and initializes all
+ * bytes in the allocated storage to zero.  If no memory is available
+ * immediately, the call will block for the specified timeout (constructed
+ * via the standard timeout API, or K_NO_WAIT or K_FOREVER) waiting for memory
+ * to be freed.  If the allocation cannot be performed by the expiration of
+ * the timeout, NULL will be returned.
+ * Allocated memory is aligned on a multiple of pointer sizes.
+ *
+ * @note @a timeout must be set to K_NO_WAIT if called from ISR.
+ * @note When CONFIG_MULTITHREADING=n any @a timeout is treated as K_NO_WAIT.
+ *
+ * @funcprops \isr_ok
+ *
+ * @param h Heap from which to allocate
+ * @param num Number of objects to allocate
+ * @param size Desired size of each object to allocate
+ * @param timeout How long to wait, or K_NO_WAIT
+ * @return A pointer to valid heap memory, or NULL
+ */
+void *k_heap_calloc(struct k_heap *h, size_t num, size_t size, k_timeout_t timeout)
+	__attribute_nonnull(1);
+
 /**
  * @brief Reallocate memory from a k_heap
  *

kernel/kheap.c

@@ -116,6 +116,25 @@ void *k_heap_alloc(struct k_heap *heap, size_t bytes, k_timeout_t timeout)
 	return ret;
 }
 
+void *k_heap_calloc(struct k_heap *heap, size_t num, size_t size, k_timeout_t timeout)
+{
+	SYS_PORT_TRACING_OBJ_FUNC_ENTER(k_heap, calloc, heap, timeout);
+
+	void *ret = NULL;
+	size_t bounds = 0U;
+
+	if (!size_mul_overflow(num, size, &bounds)) {
+		ret = k_heap_alloc(heap, bounds, timeout);
+	}
+	if (ret != NULL) {
+		(void)memset(ret, 0, bounds);
+	}
+
+	SYS_PORT_TRACING_OBJ_FUNC_EXIT(k_heap, calloc, heap, timeout, ret);
+
+	return ret;
+}
+
 void *k_heap_realloc(struct k_heap *heap, void *ptr, size_t bytes, k_timeout_t timeout)
 {
 	k_timepoint_t end = sys_timepoint_calc(timeout);