From 232237796ae40681c3a91bbdb3fd1d4c37279062 Mon Sep 17 00:00:00 2001
From: Koen Zandberg <koen@bergzand.net>
Date: Wed, 2 Sep 2020 19:16:30 +0200
Subject: [PATCH] memarray: Add memarray_calloc

The memarray_alloc can be error prone to use as the block returned can
contain data from previous uses. The memarray_calloc call added in this
commit always zeroes the block before returning it to the user.
---
 sys/include/memarray.h  | 14 ++++++++++++++
 sys/memarray/memarray.c |  9 +++++++++
 2 files changed, 23 insertions(+)

diff --git a/sys/include/memarray.h b/sys/include/memarray.h
index 11ad4ed694..f1dec1439d 100644
--- a/sys/include/memarray.h
+++ b/sys/include/memarray.h
@@ -54,6 +54,8 @@ void memarray_init(memarray_t *mem, void *data, size_t size, size_t num);
  *
  * @pre `mem != NULL`
  *
+ * @note Allocated structure is not cleared before returned
+ *
  * @param[in,out] mem   memarray pool to allocate block in
  *
  * @return pointer to allocated structure, if enough memory was available
@@ -61,6 +63,18 @@ void memarray_init(memarray_t *mem, void *data, size_t size, size_t num);
  */
 void *memarray_alloc(memarray_t *mem);
 
+/**
+ * @brief Allocate and clear memory chunk in memarray pool
+ *
+ * @pre `mem != NULL`
+ *
+ * @param[in,out] mem   memarray pool to allocate block in
+ *
+ * @return pointer to allocated structure, if enough memory was available
+ * @return NULL, on failure
+ */
+void *memarray_calloc(memarray_t *mem);
+
 /**
  * @brief Free memory chunk in memarray pool
  *
diff --git a/sys/memarray/memarray.c b/sys/memarray/memarray.c
index 1ba007638c..c046697584 100644
--- a/sys/memarray/memarray.c
+++ b/sys/memarray/memarray.c
@@ -44,6 +44,15 @@ void *memarray_alloc(memarray_t *mem)
     return free;
 }
 
+void *memarray_calloc(memarray_t *mem)
+{
+    void *new = memarray_alloc(mem);
+    if (new) {
+        memset(new, 0, mem->size);
+    }
+    return new;
+}
+
 void memarray_free(memarray_t *mem, void *ptr)
 {
     assert((mem != NULL) && (ptr != NULL));