RW_queue.c

#include <stdio.h>
#include <time.h>
#include <stdlib.h>
#include <linux/sched.h>
#include <linux/kernel.h>

#include "../../RW_sem.h"

typedef struct q_node
{
	struct task_struct* task;
	struct q_node* next;
} q_node;

typedef struct ProcQ
{
	q_node* head;
	q_node* tail;
} ProcQ;

int count = 0;



static void enqueue(struct RW_Sem* sem, struct task_struct* task)
{
	q_node* temp;
	temp = (q_node*)kmalloc(sizeof(q_node), GFP_KERNEL);
	temp->task = task;
	temp->next = NULL;

	if (sem->queue->head == NULL)
	{
		sem->queue->head = temp;
		sem->queue->tail = sem->queue->head;
	}
	else
	{
		temp->next = sem->queue->tail;
		sem->queue->tail = temp;
	}
	count++;

	temp = tail;

}

static struct task_struct* dequeue(struct RW_Sem* sem)
{
	if (sem->queue->head == NULL) {return NULL;}

	q_node* temp;
	temp = sem->queue->head;

	if(temp->next == NULL)
	{
		kfree(sem->queue->head);
		sem->queue->head = NULL;
	}
	else
	{
		while(temp->next != sem->queue->head)
		{
			temp = temp->next;
		}
		kfree(sem->queue->head);
		sem->queue->head = temp;
	}

	count--;

	task_struct* temp_task = temp->task;
	kfree(temp);
	return temp_task;
}

















DEFINE_SPINLOCK(sem_lock);

task_struct sleeping_task;

asmlinkage long sys_RW_wait(struct RW_Sem *sem)
{
	spin_lock(&sem_lock);

	if (sem->value > 0)
	{
		sem->value--;
		sleeping_task = current;
		set_current_state(TASK_INTERRUPTIBLE);
		schedule();
	}

	spin_unlock(&sem_lock);
	return 0;
}

asmlinkage long sys_RW_signal(struct RW_Sem *sem)
{
	spin_lock(&sem_lock);

	sem->value++;
	if (sem->queue->head == NULL)
	{
		wake_up_process(sleeping_task);
	}

	spin_unlock(&sem_lock);
	return 0;
}




// RW_queue.c:25: warning: ‘struct RW_Sem’ declared inside parameter list
// RW_queue.c:25: warning: its scope is only this definition or declaration, which is probably not what you want
// RW_queue.c: In function ‘enqueue’:
// RW_queue.c:28: error: ‘GFP_KERNEL’ undeclared (first use in this function)
// RW_queue.c:28: error: (Each undeclared identifier is reported only once
// RW_queue.c:28: error: for each function it appears in.)
// RW_queue.c:32: error: dereferencing pointer to incomplete type
// RW_queue.c:34: error: dereferencing pointer to incomplete type
// RW_queue.c:35: error: dereferencing pointer to incomplete type
// RW_queue.c:35: error: dereferencing pointer to incomplete type
// RW_queue.c:39: error: dereferencing pointer to incomplete type
// RW_queue.c:40: error: dereferencing pointer to incomplete type
// RW_queue.c:44: error: ‘tail’ undeclared (first use in this function)
// RW_queue.c: At top level:
// RW_queue.c:48: warning: ‘struct RW_Sem’ declared inside parameter list
// RW_queue.c: In function ‘dequeue’:
// RW_queue.c:50: error: dereferencing pointer to incomplete type
// RW_queue.c:53: error: dereferencing pointer to incomplete type
// RW_queue.c:57: error: dereferencing pointer to incomplete type
// RW_queue.c:58: error: dereferencing pointer to incomplete type
// RW_queue.c:62: error: dereferencing pointer to incomplete type
// RW_queue.c:66: error: dereferencing pointer to incomplete type
// RW_queue.c:67: error: dereferencing pointer to incomplete type
// RW_queue.c:72: error: ‘task_struct’ undeclared (first use in this function)
// RW_queue.c:72: error: ‘temp_task’ undeclared (first use in this function)
// RW_queue.c: At top level:
// RW_queue.c:93: warning: data definition has no type or storage class
// RW_queue.c:93: warning: parameter names (without types) in function declaration
// RW_queue.c:95: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’ before ‘sleeping_task’
// RW_queue.c:97: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’ before ‘long’
// RW_queue.c:113: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’ before ‘long’