linux 内核互斥锁示例

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/mutex.h>

static DEFINE_MUTEX(my_mutex);
static int shared_data = 0;

static int my_open(struct inode *inode, struct file *file) {
    mutex_lock(&my_mutex);
    shared_data++;
    printk(KERN_INFO "Shared data incremented to %d\n", shared_data);
    mutex_unlock(&my_mutex);
    return 0;
}

static int my_release(struct inode *inode, struct file *file) {
    mutex_lock(&my_mutex);
    shared_data--;
    printk(KERN_INFO "Shared data decremented to %d\n", shared_data);
    mutex_unlock(&my_mutex);
    return 0;
}

static struct file_operations fops = {
    .open = my_open,
    .release = my_release,
};

static int __init my_module_init(void) {
    printk(KERN_INFO "My module loaded\n");
    return register_chrdev(240, "my_device", &fops);
}

static void __exit my_module_exit(void) {
    unregister_chrdev(240, "my_device");
    printk(KERN_INFO "My module unloaded\n");
}

module_init(my_module_init);
module_exit(my_module_exit);

MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("A simple Linux kernel module with mutex example");