CIRCLEQ_HEAD_INITIALIZER - Linux

Overview

CIRCLEQ_HEAD_INITIALIZER initializes a circular double-linked list head to an empty list. It is typically used in kernel programming to represent circular queues.

Syntax

#include <sys/queue.h>

CIRCLEQ_HEAD(name, item);

Options/Flags

None.

Examples

Initializing a Circular Queue

CIRCLEQ_HEAD(my_queue, my_item);

CIRCLEQ_INIT(&my_queue);

Inserting Items into a Circular Queue

my_item *new_item = malloc(sizeof(my_item));

CIRCLEQ_INSERT_TAIL(&my_queue, new_item, entries);

Iterating over a Circular Queue

CIRCLEQ_FOREACH(item, &my_queue, entries) {
    // Process each item
}

Common Issues

Empty List Errors

Attempting to process an empty list can result in errors. Ensure that the list is not empty before processing its items.

Circular List Errors

Circular lists can be tricky to manipulate correctly. Avoid creating circular references or dangling pointers as they can lead to unstable system behavior.

Integration

CIRCLEQ_HEAD_INITIALIZER is commonly used with other circular queue operations such as CIRCLEQ_INSERT_HEAD, CIRCLEQ_INSERT_TAIL, and CIRCLEQ_FOREACH.

Related Commands

• CIRCLEQ_INSERT_HEAD, CIRCLEQ_INSERT_TAIL – Insert items into a circular queue.
• CIRCLEQ_FOREACH – Iterate over a circular queue.
• CIRCLEQ_REMOVE – Remove an item from a circular queue.