Write a program using 3 threads, one prints 10 'A's and the second prints 'B's and the third prints 10 'C's with synchrornization
- by user132967
Iam try to implement this questions using threads and mutex
this is my code :
include
include
include
include
include
define Num_thread 3
pthread_mutex_t lett[Num_thread];
void Sleep_rand(double max)
{
struct timespec delai;
delai.tv_sec=max;
delai.tv_nsec=0;
nanosleep(&delai,NULL);
}
void *Print_Sequence();
int main()
{
int i;
pthread_t tid[Num_thread];// this is threads identifier
for(i=0;i<Num_thread;i++)
pthread_mutex_init(&lett[i],0);
for(i=0;i<Num_thread;i++)
{
printf("i=%d\n",i);
/* create the threads /
pthread_create(&tid[i], / This variable will have the thread is after successful creation /
NULL, / send the thread attributes /
Print_Sequence, / the function the thread will run /
&i/ send the parameter's address to the function */);
}
/* Wait till threads are complete and join before main continues */
for (i = 0; i
pthread_join(tid[i], NULL);
}
return 0;
}
/* The thread will begin control in this function */
void Print_Sequence(void param)
{
int i,j=(int)param;
printf("j=%d\n",(*j));
int max;
pthread_mutex_lock(&lett[0]);
pthread_mutex_lock(&lett[1]);
for (i = 1; i <= 10; i++)
{
max=(int) (8*rand()/(RAND_MAX+1.0));
Sleep_rand( max);
printf("A");
}
pthread_mutex_unlock(&lett[0]);
pthread_mutex_lock(&lett[2]);
for (i = 1; i <= 10; i++)
{
max=(int) (2*rand()/(RAND_MAX+1.0));
Sleep_rand( max);
printf("B");
}
for (i = 1; i <= 10; i++)
{
max=(int) (15*rand()/(RAND_MAX+1.0));
Sleep_rand( max);
printf("C");
}
pthread_mutex_unlock(&lett[1]);
pthread_mutex_unlock(&lett[2]);
pthread_exit(0);
}
and the o/p is like :
AAAAAAAAAABBBBBBBBBBCCCCCCCCCCAAAAAAAAAABBBBBBBBBBCCCCCCCCCCAAAAAAAAAABBBBBBBBBBCCCCCCCCCC
COULD ANYONE PLEASE EXPLAIN WHAT IS THE WRONG WITH CODE ??
