Orion

/*
 * This file contains all the functions related to message passing and
 * inter-process communication.
 */

#include <stdint.h>
#include <stddef.h>
#include <sys/ipc.h>
#include "task.h"
#include "../proc/proc.h"
#include "../mem/mem.h"
#include "../mem/heap.h"
#include "../spinlock.h"

extern TaskQueue readyQueue;

/* Block until a message is received */
static uint8_t
block_recv(Task *task, uint32_t from)
{
//	Message *head, *prev;
//	/* Blocking for RECEIVE from any */
//	if (!task->msgQueue)
//		return 0;
//	/* Block for RECEIVE from specific process */
//	if (task->msgQueue->from != from && from != ANY) {
//		for (head = task->msgQueue;
//		     head->from != from;
//		     prev = head, head = head->next);
//		/* End of list */
//		if (!head) return 0;
//		/* Move message to start of queue */
//		if (head != task->msgQueue) {
//			prev->next = head->next;
//			head->next = task->msgQueue;
//			task->msgQueue = head;
//		}
//	}
//
//	return 1;
}

/* Send a message */
Message *
nb_send_msg(pid_t to, uint16_t type, MessageContent *msg)
{
//	Message *item, *msgSearch;
//	Task *taskSearch;
//
//	item = kmalloc(sizeof(Message));
//	memcpy(&item->msg, msg, sizeof(MessageContent));
//	item->from = current->tid;
//	item->type = type;
//	item->next = 0;
//
//	/* Find target process */
//	for (taskSearch = readyQueue;
//	     taskSearch->tid != to && taskSearch;
//	     taskSearch = taskSearch->next);
//	/* Add message to queue */
//	if (taskSearch) {
//		acquire(&taskSearch->lock);
//		if (taskSearch->msgQueue) {
//			for (msgSearch = taskSearch->msgQueue;
//			     msgSearch->next;
//			     msgSearch = msgSearch->next);
//			msgSearch->next = item;
//		} else {
//			taskSearch->msgQueue = item;
//		}
//		release(&taskSearch->lock);
//	}
//
//	if (taskSearch)
//		return item;
//	kfree(item);
//	return NULL;
}

/* Send a message and block until it is delivered */
Message *
send_msg(pid_t to, uint16_t type, MessageContent *msg)
{
//	Message *nb = nb_send_msg(to, type, msg);
//	if (!nb) return NULL;
//	block(block_send, (uint32_t) nb);
//	return nb;
}

/* Receive a message */
pid_t
nb_recv_msg(Message *buf, pid_t from)
{
//	Message *msg;
//	Task *taskSearch;
//
//	acquire(&current->lock);
//	msg = current->msgQueue;
//	if (msg && (msg->from == from || from == ANY)) {
//		current->msgQueue = msg->next;
//		memcpy(buf, msg, sizeof(Message));
//		kfree(msg);
//	}
//	release(&current->lock);
//
//	if (msg && (buf->from == from || from == ANY)) {
//		/* Find sending process */
//		for (taskSearch = readyQueue;
//		     taskSearch->tid != buf->from && taskSearch;
//		     taskSearch = taskSearch->next);
//		if (taskSearch) {
//			if (taskSearch->block.function == block_send
//			 && taskSearch->block.condition == (uint32_t) msg)
//				taskSearch->block.function = NULL;
//		}
//		return buf->from;
//	}
//	return 0;
}

/* Block until a message is received */
pid_t
recv_msg(Message *buf, pid_t from)
{
//	pid_t nb;
//check:
//	nb = nb_recv_msg(buf, from);
//	if (nb) return nb;
//	block(block_recv, from);
//	goto check;
}