Implement q_new function

JeepWay · JeepWay · commit 5aa6f257a294 · 2025-02-28T21:05:51.000+08:00
The function q_new allocates memory for an empty queue and
initializes it.

If memory allocation fails, the function will return NULL,
otherwise, return the head of the empty queue.

Change-Id: I4aa0bb5cbe20738ba435a2ecefbf352c953cb156
diff --git a/queue.c b/queue.c
@@ -13,7 +13,12 @@
 /* Create an empty queue */
 struct list_head *q_new()
 {
-    return NULL;
+    struct list_head *q = malloc(sizeof(struct list_head));
+    if (!q)
+        return NULL;
+
+    INIT_LIST_HEAD(q);
+    return q;
 }
 
 /* Free all storage used by queue */

Original file line number	Diff line number	Diff line change
`@@ -13,7 +13,12 @@`
`13`	`13`	`/* Create an empty queue */`
`14`	`14`	`struct list_head *q_new()`
`15`	`15`	`{`
`16`		`- return NULL;`
	`16`	`+ struct list_head *q = malloc(sizeof(struct list_head));`
	`17`	`+ if (!q)`
	`18`	`+ return NULL;`
	`19`	`+`
	`20`	`+ INIT_LIST_HEAD(q);`
	`21`	`+ return q;`
`17`	`22`	`}`
`18`	`23`
`19`	`24`	`/* Free all storage used by queue */`