/*
 *  * test_send.c
 *  *
 *  * This test goes with test_receive.c.
 *  * test_send.c does a loop of mq_sends,
 *  * and test_receive.c does a loop of mq_receives.
 */
#include <unistd.h>
#include <sys/types.h>
#include <stdio.h>
#include <stdlib.h>
//#include <sys/time.h>
//#include <sys/resource.h>
#include <time.h>
#include <sched.h>
//#include <sys/mman.h>
//#include <sys/fcntl.h>
#include <signal.h>
//#include <sys/rt_syscall.h>
#include <mqueue.h>
#include <errno.h>
#define P4IPC_MSGSIZE 20
#define PMODE 0666
extern int errno;

int main()
{
	int i;
	int status = 0;
	mqd_t mqfd;
	char msg_buffer[P4IPC_MSGSIZE];
	struct mq_attr attr;
	int open_flags = 0;
	int num_bytes_to_send;
	int priority_of_msg;

	printf("START OF TEST_SEND \n");

	/* Fill in attributes for message queue */
	attr.mq_maxmsg = 20;
	attr.mq_msgsize = P4IPC_MSGSIZE;
	attr.mq_flags   = 0;

	/* Set the flags for the open of the queue.
	 * * Make it a blocking open on the queue, meaning it will block if
	 * * this process tries to send to the queue and the queue is full.
	 * * (Absence of O_NONBLOCK flag implies that the open is blocking)
	 * *
	 * * Specify O_CREAT so that the file will get created if it does not
	 * * already exist.
	 * *
	 * * Specify O_WRONLY since we are only planning to write to the queue,
	 * * although we could specify O_RDWR also.
	 * */
	open_flags = 0x666;//O_WRONLY|O_CREAT;

	/* Open the queue, and create it if the receiving process hasn't
	 *  * already created it.
	 *   */
	mqfd = mq_open("myipc",open_flags,PMODE,&attr);
	if (mqfd == -1)
	{
	       	perror("mq_open failure from main");
		exit(0);
        };

	/* Fill in a test message buffer to send */
	msg_buffer[0] = 'P';
	msg_buffer[1] = 'R';
	msg_buffer[2] = 'I';
	msg_buffer[3] = 'O';
	msg_buffer[4] = 'R';
	msg_buffer[5] = 'I';
	msg_buffer[6] = 'T';
	msg_buffer[7] = 'Y';
	msg_buffer[8] = '1';
	msg_buffer[9] = 'a';

	num_bytes_to_send = 10;
	priority_of_msg = 1;

	/* Perform the send 10 times */
	for (i=0; i<10; i++)
        {
	        status = mq_send(mqfd,msg_buffer,num_bytes_to_send,priority_of_msg);
	    if (status == -1)
	           perror("mq_send failure on mqfd");
	    else
	           printf("successful call to mq_send, i = %d\n",i);
					    }

	/* Done with queue, so close it */
	if (mq_close(mqfd) == -1)
		    perror("mq_close failure on mqfd");

	printf("About to exit the sending process after closing the queue \n");
}