Implement q_new to create an empty queue

yy214123 · yy214123 · commit bda78c11542f · 2025-02-27T12:52:31.000+08:00
Allocate memory for a new queue and initialize its list head.
Return NULL if memory allocation fails.

Change-Id: I31f38aa864e5587528bfeb0f3e09cd6ad4056402
diff --git a/queue.c b/queue.c
@@ -13,7 +13,11 @@
 /* Create an empty queue */
 struct list_head *q_new()
 {
-    return NULL;
+    struct list_head *head = malloc(sizeof(struct list_head));
+    if (!head)
+        return NULL;
+    INIT_LIST_HEAD(head);
+    return head;
 }
 
 /* Free all storage used by queue */

Original file line number	Diff line number	Diff line change
`@@ -13,7 +13,11 @@`
`13`	`13`	`/* Create an empty queue */`
`14`	`14`	`struct list_head *q_new()`
`15`	`15`	`{`
`16`		`- return NULL;`
	`16`	`+ struct list_head *head = malloc(sizeof(struct list_head));`
	`17`	`+ if (!head)`
	`18`	`+ return NULL;`
	`19`	`+ INIT_LIST_HEAD(head);`
	`20`	`+ return head;`
`17`	`21`	`}`
`18`	`22`
`19`	`23`	`/* Free all storage used by queue */`