How to use Mutex in C

dharmdeep · #1 11-11-2006, 10:04 AM

Hi Friends,

I have made a client server application in which multiple clients can interact with server. but when two or more clients get connected at the same time then memory error occurs. So I think i have to use some synchronization tecnique to get things working properly. i thought of using mutex. Can anybody help me with some sample code as how to use mutex in C under windows.

Bill Pursell · #2 11-29-2006, 04:32 PM

I can't help with your windows specific question, but the following works on OS X. Probably the only thing you'll need to change, if anything, is the names of the header files.

Code:

#include <semaphore.h>
#include <stdlib.h>
#include <stdio.h>
#include <sys/types.h>
#include <unistd.h>

int
main(int argc, char **argv)
{
        sem_t *sem;
        const char *name;

        name = (argc > 1) ? argv[1] : "foo";
        sem = sem_open(name, O_CREAT, 0777, 1);

        if (sem == (sem_t *)SEM_FAILED) {
                perror(name);
                exit(EXIT_FAILURE);
        }

        fprintf(stderr, "%d waits...", getpid());

        if (sem_wait(sem) == -1) {
                perror(name);
                exit(EXIT_FAILURE);
        }

        fprintf(stderr, "Got %s\n", name);
        sleep(5);
        sem_post(sem);

        return EXIT_SUCCESS;
}

shabbir · #3 11-29-2006, 10:53 PM

Good sample I must say.