Thread and Mutex Code, C (gcc)

Thread and Mutex Code

#include <pthread.h>
#include <signal.h>
#include <time.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <semaphore.h>
#include <mqueue.h>
#include <unistd.h>

#define QUEUE_NAME "/queue_b"

#define QUEUE_MAX_SIZE 128
#define TIMER_INTERVAL 2   //sec
#define TIMER_RUN_TIME 3   //For Process End.
#define THREAD_WAIT_TICK 1 //us

#define DEBUG_MESSAGE 1

//----Call Debug Function---------------------------
void err_abort(int status, char* message)
{
  fprintf(stderr, "%s\n", message);
  exit(status);
}

void errno_abort(char* message)
{
  perror(message);
  exit(EXIT_FAILURE);
}
//--------------------------------------------------------
//----Thread_A Init and Functions-------------------------
pthread_mutex_t mutex_A = PTHREAD_MUTEX_INITIALIZER;

void * thread_A_main(void * args) 
{
#if (defined(DEBUG_MESSAGE) && DEBUG_MESSAGE)
    printf("thread_A in\n");
#endif
    while(1)
    {
        if(pthread_mutex_trylock(&mutex_A) == 0)   // if unlock, lock it 
        {
            printf("HELLO\n");
        }
        usleep(THREAD_WAIT_TICK);
    }
    pthread_exit(0);
}

//--------------------------------------------------------
//----Thread_B Init and Functions-------------------------

void * thread_B_main(void * args) 
{
	mqd_t mq;
	ssize_t bytes_read;
    struct mq_attr attr;
    char buffer[QUEUE_MAX_SIZE + 1];

/* initialize the queue attributes */
    attr.mq_flags = 0;
    attr.mq_maxmsg = 10;
    attr.mq_msgsize = QUEUE_MAX_SIZE;
    attr.mq_curmsgs = 0;

/* create the message queue */
    mq = mq_open(QUEUE_NAME, O_CREAT | O_RDONLY | O_NONBLOCK , 0644, &attr);
#if (defined(DEBUG_MESSAGE) && DEBUG_MESSAGE)
    printf("thread_B in\n");
#endif
    while(1)  
    {
 		memset(buffer, 0x00, sizeof(buffer));
        bytes_read = mq_receive(mq, buffer, QUEUE_MAX_SIZE, NULL);
        if(bytes_read >= 0)
        {
#if (defined(DEBUG_MESSAGE) && DEBUG_MESSAGE)
 			printf("Thread_B: Received message: %s\n", buffer);
#endif
 			if (pthread_mutex_unlock(&mutex_A) != 0)
                err_abort(0, "Error Unlock A mutex");
        }
        usleep(THREAD_WAIT_TICK);
    }

/* cleanup */
    mq_close(mq);
    mq_unlink(QUEUE_NAME);

pthread_exit(0);
}
//--------------------------------------------------------
//----Timer_C Init and Functions--------------------------
pthread_mutex_t timer_mutex = PTHREAD_MUTEX_INITIALIZER;
pthread_cond_t timer_cond = PTHREAD_COND_INITIALIZER;
int time_counter = 0;

void timer_C(union sigval C)
{
    mqd_t mq;
    char buffer[QUEUE_MAX_SIZE];
    if (pthread_mutex_lock(&timer_mutex) != 0)
        err_abort(0, "Error Lock Time mutex");
    //----------------Time_C Program--------------------
    mq = mq_open(QUEUE_NAME, O_WRONLY);
    time_counter++;
#if (defined(DEBUG_MESSAGE) && DEBUG_MESSAGE)
    printf("Timer_C in %d \n",time_counter);
#endif
    snprintf(buffer, sizeof(buffer), "MESSAGE %d", time_counter);
    if(mq_send(mq, buffer, strlen(buffer), 0) != 0)
        err_abort(0, "Error mq enque");
    mq_close(mq);
    //--------------------------------------------------
    if (time_counter >= TIMER_RUN_TIME) 
    {
        if (pthread_cond_signal(&timer_cond) != 0)     //if counter reached, let the process end.
          err_abort(0, "Error Time Signal condition");
    }
    
    if (pthread_mutex_unlock(&timer_mutex) != 0)
    err_abort(0, "Error Unlock Time mutex");
}

void create_timer()
{
  timer_t timer_id;
  struct itimerspec ts;
  struct sigevent se;
  /*
   * Set the sigevent structure to cause the signal to be
   * delivered by creating a new thread.
   */
  se.sigev_notify = SIGEV_THREAD;
  se.sigev_value.sival_ptr = &timer_id;
  se.sigev_notify_function = timer_C;
  se.sigev_notify_attributes = NULL;

if (timer_create(CLOCK_REALTIME, &se, &timer_id) == -1)
    errno_abort("Error Create timer");

ts.it_value.tv_sec = TIMER_INTERVAL;
  ts.it_interval.tv_sec = TIMER_INTERVAL;

if (timer_settime(timer_id, 0, &ts, 0) == -1)
    errno_abort("Error Set timer");
}

int main()
{
  pthread_t thread_a, thread_b;

create_timer();
  
  pthread_create(&thread_a, NULL, &thread_A_main, NULL);
  pthread_create(&thread_b, NULL, &thread_B_main, NULL);

//---------Waitting Timer_C End for End the Process------------- 
/*
 * To design for End of Timer,
 * beaceuse of some online compiler print after process end.
 */
    if (pthread_mutex_lock(&timer_mutex) != 0)
        err_abort(0, "Lock mutex");

if (pthread_cond_wait(&timer_cond, &timer_mutex) != 0)
        err_abort(0, "Wait on Timer condition");
    if(pthread_cancel(thread_a) != 0)
        err_abort(0, "Error Cancel Thread A");
    if(pthread_cancel(thread_b) != 0)
        err_abort(0, "Error Cancel Thread B");
#if (defined(DEBUG_MESSAGE) && DEBUG_MESSAGE)
    printf("End of Process!");
#endif
    mq_unlink(QUEUE_NAME);
    return 0;
    if (pthread_mutex_unlock(&timer_mutex) != 0)
        err_abort(0, "Error Unlock Timer mutex");
//--------------------------------------------------------------
  pthread_join(thread_a, NULL);  // wait thread end.
  pthread_join(thread_b, NULL);  // wait thread end.
  mq_unlink(QUEUE_NAME);
  return 0;
}


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