Thread: semaphore functions

this is my c code regarding threads ....

Code:

#include<stdio.h>
#include<pthread.h>
//#include<semaphores.h>


void *function1()
{
        printf("thread numbers(1-10): %ld\n",pthread_self());
}

void *function2()
{
        printf("thread number 11 : %ld\n",pthread_self());
}

int main()
{
        int i;
        pthread_t thread[10],thread11;
        for(i=0;i<10;i++)
        {
           pthread_create(&thread[i],NULL,&function1,NULL);
        }
        pthread_create(&thread11,NULL,&function2,NULL);
}

thread 11 should execute after all the 10 threads have completed their process

i want to use semaphore fuctions instead thread_join ...... can anyone help

in implementing this.....


thanks in advance..

pthread

Code:

#include <stdlib.h>
#include <stdio.h>
#include <pthread.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/ipc.h>
#include <sys/sem.h>

union semun {
            int val;
            struct semid_ds *buf;
            unsigned short  *array;
};

int semset_id;          /*set id*/
struct sembuf sem_op;   /*struct for operations*/

void *function1(void *arg)
{
        printf("thread numbers(1-10)\n");

        /* increase semaphore counter */
        sem_op.sem_num = 0;
        sem_op.sem_op = 1;
        sem_op.sem_flg = 0;
        semop(semset_id, &sem_op, 1);

        pthread_exit(NULL);
}

void *function2(void *arg)
{

        /* wait till semaphore value is 10 */
        sem_op.sem_num = 0;
        sem_op.sem_op = -10;
        sem_op.sem_flg = 0;
        semop(semset_id, &sem_op, 1);

        printf("thread number 11\n");

        pthread_exit(NULL);
}

int main()
{
        int i;
        pthread_t thread[10],thread11;
        union semun sem_val;            /* sem value */
        void *ret_val;

        semset_id = semget(IPC_PRIVATE, 1, 0600);       /* create set */
        if (semset_id == -1)
        {
                perror("Crap");
                exit(1);
        }

        sem_val.val = 0;
        semctl(semset_id, 0, SETVAL, sem_val);

        if (pthread_create(&thread11,NULL,function2,NULL) != 0)
        {
                perror("Create 11");
                exit(1);
        }

        for(i=0;i<10;i++)
        {
                if (pthread_create(&thread[i],NULL,function1,NULL) != 0)
                {
                        perror("Create");
                        exit(1);
                }

        }

        for (i = 0; i < 10; i++)
                pthread_join(thread[i], &ret_val);

        pthread_join(thread11, &ret_val);

        return 1;
}

theres probably a better way to do this, I haven't used semaphores for awhile (maybe without the globals), but this does work
so should get you on the way

output:
thread numbers(1-10)
thread numbers(1-10)
thread numbers(1-10)
thread numbers(1-10)
thread numbers(1-10)
thread numbers(1-10)
thread numbers(1-10)
thread numbers(1-10)
thread numbers(1-10)
thread numbers(1-10)
thread number 11

whether the 11th is created before the other 10 or after

thanx sl4nted.......

is there any other solution for that code ..... is it possible by using sem_wait ,sem_post,sem_init functions .....


thanx

pthread